mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
c078669340
When we finish processing ASCONF_ACK chunk, we try to send the next queued ASCONF. This action runs the sctp state machine recursively and it's not prepared to do so. kernel BUG at kernel/timer.c:790! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/module/ipv6/initstate Modules linked in: sha256_generic sctp libcrc32c ipv6 dm_multipath uinput 8139too i2c_piix4 8139cp mii i2c_core pcspkr virtio_net joydev floppy virtio_blk virtio_pci [last unloaded: scsi_wait_scan] Pid: 0, comm: swapper Not tainted 2.6.34-rc4 #15 /Bochs EIP: 0060:[<c044a2ef>] EFLAGS: 00010286 CPU: 0 EIP is at add_timer+0xd/0x1b EAX: cecbab14 EBX: 000000f0 ECX: c0957b1c EDX: 03595cf4 ESI: cecba800 EDI: cf276f00 EBP: c0957aa0 ESP: c0957aa0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process swapper (pid: 0, ti=c0956000 task=c0988ba0 task.ti=c0956000) Stack: c0957ae0 d1851214 c0ab62e4 c0ab5f26 0500ffff 00000004 00000005 00000004 <0> 00000000 d18694fd 00000004 1666b892 cecba800 cecba800 c0957b14 00000004 <0> c0957b94 d1851b11 ceda8b00 cecba800 cf276f00 00000001 c0957b14 000000d0 Call Trace: [<d1851214>] ? sctp_side_effects+0x607/0xdfc [sctp] [<d1851b11>] ? sctp_do_sm+0x108/0x159 [sctp] [<d1863386>] ? sctp_pname+0x0/0x1d [sctp] [<d1861a56>] ? sctp_primitive_ASCONF+0x36/0x3b [sctp] [<d185657c>] ? sctp_process_asconf_ack+0x2a4/0x2d3 [sctp] [<d184e35c>] ? sctp_sf_do_asconf_ack+0x1dd/0x2b4 [sctp] [<d1851ac1>] ? sctp_do_sm+0xb8/0x159 [sctp] [<d1863334>] ? sctp_cname+0x0/0x52 [sctp] [<d1854377>] ? sctp_assoc_bh_rcv+0xac/0xe1 [sctp] [<d1858f0f>] ? sctp_inq_push+0x2d/0x30 [sctp] [<d186329d>] ? sctp_rcv+0x797/0x82e [sctp] Tested-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Yuansong Qiao <ysqiao@research.ait.ie> Signed-off-by: Shuaijun Zhang <szhang@research.ait.ie> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
6093 lines
190 KiB
C
6093 lines
190 KiB
C
/* SCTP kernel implementation
|
|
* (C) Copyright IBM Corp. 2001, 2004
|
|
* Copyright (c) 1999-2000 Cisco, Inc.
|
|
* Copyright (c) 1999-2001 Motorola, Inc.
|
|
* Copyright (c) 2001-2002 Intel Corp.
|
|
* Copyright (c) 2002 Nokia Corp.
|
|
*
|
|
* This is part of the SCTP Linux Kernel Implementation.
|
|
*
|
|
* These are the state functions for the state machine.
|
|
*
|
|
* This SCTP implementation is free software;
|
|
* you can redistribute it and/or modify it under the terms of
|
|
* the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This SCTP implementation is distributed in the hope that it
|
|
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
|
|
* ************************
|
|
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
* See the GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with GNU CC; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
*
|
|
* Please send any bug reports or fixes you make to the
|
|
* email address(es):
|
|
* lksctp developers <lksctp-developers@lists.sourceforge.net>
|
|
*
|
|
* Or submit a bug report through the following website:
|
|
* http://www.sf.net/projects/lksctp
|
|
*
|
|
* Written or modified by:
|
|
* La Monte H.P. Yarroll <piggy@acm.org>
|
|
* Karl Knutson <karl@athena.chicago.il.us>
|
|
* Mathew Kotowsky <kotowsky@sctp.org>
|
|
* Sridhar Samudrala <samudrala@us.ibm.com>
|
|
* Jon Grimm <jgrimm@us.ibm.com>
|
|
* Hui Huang <hui.huang@nokia.com>
|
|
* Dajiang Zhang <dajiang.zhang@nokia.com>
|
|
* Daisy Chang <daisyc@us.ibm.com>
|
|
* Ardelle Fan <ardelle.fan@intel.com>
|
|
* Ryan Layer <rmlayer@us.ibm.com>
|
|
* Kevin Gao <kevin.gao@intel.com>
|
|
*
|
|
* Any bugs reported given to us we will try to fix... any fixes shared will
|
|
* be incorporated into the next SCTP release.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/ip.h>
|
|
#include <linux/ipv6.h>
|
|
#include <linux/net.h>
|
|
#include <linux/inet.h>
|
|
#include <linux/slab.h>
|
|
#include <net/sock.h>
|
|
#include <net/inet_ecn.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/sctp/sctp.h>
|
|
#include <net/sctp/sm.h>
|
|
#include <net/sctp/structs.h>
|
|
|
|
static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
const void *payload,
|
|
size_t paylen);
|
|
static int sctp_eat_data(const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands);
|
|
static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
|
|
const struct sctp_chunk *chunk);
|
|
static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_chunk *err_chunk);
|
|
static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
|
|
|
|
static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
|
|
__be16 error, int sk_err,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_transport *transport);
|
|
|
|
static sctp_disposition_t sctp_sf_abort_violation(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands,
|
|
const __u8 *payload,
|
|
const size_t paylen);
|
|
|
|
static sctp_disposition_t sctp_sf_violation_chunklen(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
|
|
static sctp_disposition_t sctp_sf_violation_paramlen(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg, void *ext,
|
|
sctp_cmd_seq_t *commands);
|
|
|
|
static sctp_disposition_t sctp_sf_violation_ctsn(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
|
|
static sctp_disposition_t sctp_sf_violation_chunk(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
|
|
static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
struct sctp_chunk *chunk);
|
|
|
|
static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands);
|
|
|
|
/* Small helper function that checks if the chunk length
|
|
* is of the appropriate length. The 'required_length' argument
|
|
* is set to be the size of a specific chunk we are testing.
|
|
* Return Values: 1 = Valid length
|
|
* 0 = Invalid length
|
|
*
|
|
*/
|
|
static inline int
|
|
sctp_chunk_length_valid(struct sctp_chunk *chunk,
|
|
__u16 required_length)
|
|
{
|
|
__u16 chunk_length = ntohs(chunk->chunk_hdr->length);
|
|
|
|
if (unlikely(chunk_length < required_length))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**********************************************************
|
|
* These are the state functions for handling chunk events.
|
|
**********************************************************/
|
|
|
|
/*
|
|
* Process the final SHUTDOWN COMPLETE.
|
|
*
|
|
* Section: 4 (C) (diagram), 9.2
|
|
* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
|
|
* that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
|
|
* discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
|
|
* should stop the T2-shutdown timer and remove all knowledge of the
|
|
* association (and thus the association enters the CLOSED state).
|
|
*
|
|
* Verification Tag: 8.5.1(C), sctpimpguide 2.41.
|
|
* C) Rules for packet carrying SHUTDOWN COMPLETE:
|
|
* ...
|
|
* - The receiver of a SHUTDOWN COMPLETE shall accept the packet
|
|
* if the Verification Tag field of the packet matches its own tag and
|
|
* the T bit is not set
|
|
* OR
|
|
* it is set to its peer's tag and the T bit is set in the Chunk
|
|
* Flags.
|
|
* Otherwise, the receiver MUST silently discard the packet
|
|
* and take no further action. An endpoint MUST ignore the
|
|
* SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_ulpevent *ev;
|
|
|
|
if (!sctp_vtag_verify_either(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* RFC 2960 6.10 Bundling
|
|
*
|
|
* An endpoint MUST NOT bundle INIT, INIT ACK or
|
|
* SHUTDOWN COMPLETE with any other chunks.
|
|
*/
|
|
if (!chunk->singleton)
|
|
return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* RFC 2960 10.2 SCTP-to-ULP
|
|
*
|
|
* H) SHUTDOWN COMPLETE notification
|
|
*
|
|
* When SCTP completes the shutdown procedures (section 9.2) this
|
|
* notification is passed to the upper layer.
|
|
*/
|
|
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
|
|
0, 0, 0, NULL, GFP_ATOMIC);
|
|
if (ev)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ev));
|
|
|
|
/* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
|
|
* will verify that it is in SHUTDOWN-ACK-SENT state, if it is
|
|
* not the chunk should be discarded. If the endpoint is in
|
|
* the SHUTDOWN-ACK-SENT state the endpoint should stop the
|
|
* T2-shutdown timer and remove all knowledge of the
|
|
* association (and thus the association enters the CLOSED
|
|
* state).
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_CLOSED));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
/*
|
|
* Respond to a normal INIT chunk.
|
|
* We are the side that is being asked for an association.
|
|
*
|
|
* Section: 5.1 Normal Establishment of an Association, B
|
|
* B) "Z" shall respond immediately with an INIT ACK chunk. The
|
|
* destination IP address of the INIT ACK MUST be set to the source
|
|
* IP address of the INIT to which this INIT ACK is responding. In
|
|
* the response, besides filling in other parameters, "Z" must set the
|
|
* Verification Tag field to Tag_A, and also provide its own
|
|
* Verification Tag (Tag_Z) in the Initiate Tag field.
|
|
*
|
|
* Verification Tag: Must be 0.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *repl;
|
|
struct sctp_association *new_asoc;
|
|
struct sctp_chunk *err_chunk;
|
|
struct sctp_packet *packet;
|
|
sctp_unrecognized_param_t *unk_param;
|
|
int len;
|
|
|
|
/* 6.10 Bundling
|
|
* An endpoint MUST NOT bundle INIT, INIT ACK or
|
|
* SHUTDOWN COMPLETE with any other chunks.
|
|
*
|
|
* IG Section 2.11.2
|
|
* Furthermore, we require that the receiver of an INIT chunk MUST
|
|
* enforce these rules by silently discarding an arriving packet
|
|
* with an INIT chunk that is bundled with other chunks.
|
|
*/
|
|
if (!chunk->singleton)
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* If the packet is an OOTB packet which is temporarily on the
|
|
* control endpoint, respond with an ABORT.
|
|
*/
|
|
if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
|
|
SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
|
|
* Tag.
|
|
*/
|
|
if (chunk->sctp_hdr->vtag != 0)
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the INIT chunk has a valid length.
|
|
* Normally, this would cause an ABORT with a Protocol Violation
|
|
* error, but since we don't have an association, we'll
|
|
* just discard the packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* If the INIT is coming toward a closing socket, we'll send back
|
|
* and ABORT. Essentially, this catches the race of INIT being
|
|
* backloged to the socket at the same time as the user isses close().
|
|
* Since the socket and all its associations are going away, we
|
|
* can treat this OOTB
|
|
*/
|
|
if (sctp_sstate(ep->base.sk, CLOSING))
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
|
|
/* Verify the INIT chunk before processing it. */
|
|
err_chunk = NULL;
|
|
if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
|
|
(sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
|
|
&err_chunk)) {
|
|
/* This chunk contains fatal error. It is to be discarded.
|
|
* Send an ABORT, with causes if there is any.
|
|
*/
|
|
if (err_chunk) {
|
|
packet = sctp_abort_pkt_new(ep, asoc, arg,
|
|
(__u8 *)(err_chunk->chunk_hdr) +
|
|
sizeof(sctp_chunkhdr_t),
|
|
ntohs(err_chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t));
|
|
|
|
sctp_chunk_free(err_chunk);
|
|
|
|
if (packet) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
} else {
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
} else {
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
|
|
commands);
|
|
}
|
|
}
|
|
|
|
/* Grab the INIT header. */
|
|
chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
|
|
|
|
/* Tag the variable length parameters. */
|
|
chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
|
|
|
|
new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
|
|
if (!new_asoc)
|
|
goto nomem;
|
|
|
|
if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
|
|
sctp_scope(sctp_source(chunk)),
|
|
GFP_ATOMIC) < 0)
|
|
goto nomem_init;
|
|
|
|
/* The call, sctp_process_init(), can fail on memory allocation. */
|
|
if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
|
|
sctp_source(chunk),
|
|
(sctp_init_chunk_t *)chunk->chunk_hdr,
|
|
GFP_ATOMIC))
|
|
goto nomem_init;
|
|
|
|
/* B) "Z" shall respond immediately with an INIT ACK chunk. */
|
|
|
|
/* If there are errors need to be reported for unknown parameters,
|
|
* make sure to reserve enough room in the INIT ACK for them.
|
|
*/
|
|
len = 0;
|
|
if (err_chunk)
|
|
len = ntohs(err_chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t);
|
|
|
|
repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
|
|
if (!repl)
|
|
goto nomem_init;
|
|
|
|
/* If there are errors need to be reported for unknown parameters,
|
|
* include them in the outgoing INIT ACK as "Unrecognized parameter"
|
|
* parameter.
|
|
*/
|
|
if (err_chunk) {
|
|
/* Get the "Unrecognized parameter" parameter(s) out of the
|
|
* ERROR chunk generated by sctp_verify_init(). Since the
|
|
* error cause code for "unknown parameter" and the
|
|
* "Unrecognized parameter" type is the same, we can
|
|
* construct the parameters in INIT ACK by copying the
|
|
* ERROR causes over.
|
|
*/
|
|
unk_param = (sctp_unrecognized_param_t *)
|
|
((__u8 *)(err_chunk->chunk_hdr) +
|
|
sizeof(sctp_chunkhdr_t));
|
|
/* Replace the cause code with the "Unrecognized parameter"
|
|
* parameter type.
|
|
*/
|
|
sctp_addto_chunk(repl, len, unk_param);
|
|
sctp_chunk_free(err_chunk);
|
|
}
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
|
|
/*
|
|
* Note: After sending out INIT ACK with the State Cookie parameter,
|
|
* "Z" MUST NOT allocate any resources, nor keep any states for the
|
|
* new association. Otherwise, "Z" will be vulnerable to resource
|
|
* attacks.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
|
|
nomem_init:
|
|
sctp_association_free(new_asoc);
|
|
nomem:
|
|
if (err_chunk)
|
|
sctp_chunk_free(err_chunk);
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Respond to a normal INIT ACK chunk.
|
|
* We are the side that is initiating the association.
|
|
*
|
|
* Section: 5.1 Normal Establishment of an Association, C
|
|
* C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
|
|
* timer and leave COOKIE-WAIT state. "A" shall then send the State
|
|
* Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
|
|
* the T1-cookie timer, and enter the COOKIE-ECHOED state.
|
|
*
|
|
* Note: The COOKIE ECHO chunk can be bundled with any pending outbound
|
|
* DATA chunks, but it MUST be the first chunk in the packet and
|
|
* until the COOKIE ACK is returned the sender MUST NOT send any
|
|
* other packets to the peer.
|
|
*
|
|
* Verification Tag: 3.3.3
|
|
* If the value of the Initiate Tag in a received INIT ACK chunk is
|
|
* found to be 0, the receiver MUST treat it as an error and close the
|
|
* association by transmitting an ABORT.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_init_chunk_t *initchunk;
|
|
struct sctp_chunk *err_chunk;
|
|
struct sctp_packet *packet;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* 6.10 Bundling
|
|
* An endpoint MUST NOT bundle INIT, INIT ACK or
|
|
* SHUTDOWN COMPLETE with any other chunks.
|
|
*/
|
|
if (!chunk->singleton)
|
|
return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the INIT-ACK chunk has a valid length */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
/* Grab the INIT header. */
|
|
chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
|
|
|
|
/* Verify the INIT chunk before processing it. */
|
|
err_chunk = NULL;
|
|
if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
|
|
(sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
|
|
&err_chunk)) {
|
|
|
|
sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
|
|
|
|
/* This chunk contains fatal error. It is to be discarded.
|
|
* Send an ABORT, with causes. If there are no causes,
|
|
* then there wasn't enough memory. Just terminate
|
|
* the association.
|
|
*/
|
|
if (err_chunk) {
|
|
packet = sctp_abort_pkt_new(ep, asoc, arg,
|
|
(__u8 *)(err_chunk->chunk_hdr) +
|
|
sizeof(sctp_chunkhdr_t),
|
|
ntohs(err_chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t));
|
|
|
|
sctp_chunk_free(err_chunk);
|
|
|
|
if (packet) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
error = SCTP_ERROR_INV_PARAM;
|
|
}
|
|
}
|
|
|
|
/* SCTP-AUTH, Section 6.3:
|
|
* It should be noted that if the receiver wants to tear
|
|
* down an association in an authenticated way only, the
|
|
* handling of malformed packets should not result in
|
|
* tearing down the association.
|
|
*
|
|
* This means that if we only want to abort associations
|
|
* in an authenticated way (i.e AUTH+ABORT), then we
|
|
* can't destroy this association just becuase the packet
|
|
* was malformed.
|
|
*/
|
|
if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
|
|
asoc, chunk->transport);
|
|
}
|
|
|
|
/* Tag the variable length parameters. Note that we never
|
|
* convert the parameters in an INIT chunk.
|
|
*/
|
|
chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
|
|
|
|
initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
|
|
SCTP_PEER_INIT(initchunk));
|
|
|
|
/* Reset init error count upon receipt of INIT-ACK. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
|
|
|
|
/* 5.1 C) "A" shall stop the T1-init timer and leave
|
|
* COOKIE-WAIT state. "A" shall then ... start the T1-cookie
|
|
* timer, and enter the COOKIE-ECHOED state.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
|
|
|
|
/* SCTP-AUTH: genereate the assocition shared keys so that
|
|
* we can potentially signe the COOKIE-ECHO.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
|
|
|
|
/* 5.1 C) "A" shall then send the State Cookie received in the
|
|
* INIT ACK chunk in a COOKIE ECHO chunk, ...
|
|
*/
|
|
/* If there is any errors to report, send the ERROR chunk generated
|
|
* for unknown parameters as well.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
|
|
SCTP_CHUNK(err_chunk));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Respond to a normal COOKIE ECHO chunk.
|
|
* We are the side that is being asked for an association.
|
|
*
|
|
* Section: 5.1 Normal Establishment of an Association, D
|
|
* D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
|
|
* with a COOKIE ACK chunk after building a TCB and moving to
|
|
* the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
|
|
* any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
|
|
* chunk MUST be the first chunk in the packet.
|
|
*
|
|
* IMPLEMENTATION NOTE: An implementation may choose to send the
|
|
* Communication Up notification to the SCTP user upon reception
|
|
* of a valid COOKIE ECHO chunk.
|
|
*
|
|
* Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
|
|
* D) Rules for packet carrying a COOKIE ECHO
|
|
*
|
|
* - When sending a COOKIE ECHO, the endpoint MUST use the value of the
|
|
* Initial Tag received in the INIT ACK.
|
|
*
|
|
* - The receiver of a COOKIE ECHO follows the procedures in Section 5.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type, void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_association *new_asoc;
|
|
sctp_init_chunk_t *peer_init;
|
|
struct sctp_chunk *repl;
|
|
struct sctp_ulpevent *ev, *ai_ev = NULL;
|
|
int error = 0;
|
|
struct sctp_chunk *err_chk_p;
|
|
struct sock *sk;
|
|
|
|
/* If the packet is an OOTB packet which is temporarily on the
|
|
* control endpoint, respond with an ABORT.
|
|
*/
|
|
if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
|
|
SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* Make sure that the COOKIE_ECHO chunk has a valid length.
|
|
* In this case, we check that we have enough for at least a
|
|
* chunk header. More detailed verification is done
|
|
* in sctp_unpack_cookie().
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* If the endpoint is not listening or if the number of associations
|
|
* on the TCP-style socket exceed the max backlog, respond with an
|
|
* ABORT.
|
|
*/
|
|
sk = ep->base.sk;
|
|
if (!sctp_sstate(sk, LISTENING) ||
|
|
(sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
|
|
/* "Decode" the chunk. We have no optional parameters so we
|
|
* are in good shape.
|
|
*/
|
|
chunk->subh.cookie_hdr =
|
|
(struct sctp_signed_cookie *)chunk->skb->data;
|
|
if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t)))
|
|
goto nomem;
|
|
|
|
/* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
|
|
* "Z" will reply with a COOKIE ACK chunk after building a TCB
|
|
* and moving to the ESTABLISHED state.
|
|
*/
|
|
new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
|
|
&err_chk_p);
|
|
|
|
/* FIXME:
|
|
* If the re-build failed, what is the proper error path
|
|
* from here?
|
|
*
|
|
* [We should abort the association. --piggy]
|
|
*/
|
|
if (!new_asoc) {
|
|
/* FIXME: Several errors are possible. A bad cookie should
|
|
* be silently discarded, but think about logging it too.
|
|
*/
|
|
switch (error) {
|
|
case -SCTP_IERROR_NOMEM:
|
|
goto nomem;
|
|
|
|
case -SCTP_IERROR_STALE_COOKIE:
|
|
sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
|
|
err_chk_p);
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
case -SCTP_IERROR_BAD_SIG:
|
|
default:
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
}
|
|
|
|
|
|
/* Delay state machine commands until later.
|
|
*
|
|
* Re-build the bind address for the association is done in
|
|
* the sctp_unpack_cookie() already.
|
|
*/
|
|
/* This is a brand-new association, so these are not yet side
|
|
* effects--it is safe to run them here.
|
|
*/
|
|
peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
|
|
|
|
if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
|
|
&chunk->subh.cookie_hdr->c.peer_addr,
|
|
peer_init, GFP_ATOMIC))
|
|
goto nomem_init;
|
|
|
|
/* SCTP-AUTH: Now that we've populate required fields in
|
|
* sctp_process_init, set up the assocaition shared keys as
|
|
* necessary so that we can potentially authenticate the ACK
|
|
*/
|
|
error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
|
|
if (error)
|
|
goto nomem_init;
|
|
|
|
/* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
|
|
* is supposed to be authenticated and we have to do delayed
|
|
* authentication. We've just recreated the association using
|
|
* the information in the cookie and now it's much easier to
|
|
* do the authentication.
|
|
*/
|
|
if (chunk->auth_chunk) {
|
|
struct sctp_chunk auth;
|
|
sctp_ierror_t ret;
|
|
|
|
/* set-up our fake chunk so that we can process it */
|
|
auth.skb = chunk->auth_chunk;
|
|
auth.asoc = chunk->asoc;
|
|
auth.sctp_hdr = chunk->sctp_hdr;
|
|
auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
|
|
sizeof(sctp_chunkhdr_t));
|
|
skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
|
|
auth.transport = chunk->transport;
|
|
|
|
ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
|
|
|
|
/* We can now safely free the auth_chunk clone */
|
|
kfree_skb(chunk->auth_chunk);
|
|
|
|
if (ret != SCTP_IERROR_NO_ERROR) {
|
|
sctp_association_free(new_asoc);
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
}
|
|
|
|
repl = sctp_make_cookie_ack(new_asoc, chunk);
|
|
if (!repl)
|
|
goto nomem_init;
|
|
|
|
/* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* D) IMPLEMENTATION NOTE: An implementation may choose to
|
|
* send the Communication Up notification to the SCTP user
|
|
* upon reception of a valid COOKIE ECHO chunk.
|
|
*/
|
|
ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
|
|
new_asoc->c.sinit_num_ostreams,
|
|
new_asoc->c.sinit_max_instreams,
|
|
NULL, GFP_ATOMIC);
|
|
if (!ev)
|
|
goto nomem_ev;
|
|
|
|
/* Sockets API Draft Section 5.3.1.6
|
|
* When a peer sends a Adaptation Layer Indication parameter , SCTP
|
|
* delivers this notification to inform the application that of the
|
|
* peers requested adaptation layer.
|
|
*/
|
|
if (new_asoc->peer.adaptation_ind) {
|
|
ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
|
|
GFP_ATOMIC);
|
|
if (!ai_ev)
|
|
goto nomem_aiev;
|
|
}
|
|
|
|
/* Add all the state machine commands now since we've created
|
|
* everything. This way we don't introduce memory corruptions
|
|
* during side-effect processing and correclty count established
|
|
* associations.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_ESTABLISHED));
|
|
SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
|
|
SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
|
|
|
|
if (new_asoc->autoclose)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
|
|
/* This will send the COOKIE ACK */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
|
|
/* Queue the ASSOC_CHANGE event */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
|
|
|
|
/* Send up the Adaptation Layer Indication event */
|
|
if (ai_ev)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ai_ev));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem_aiev:
|
|
sctp_ulpevent_free(ev);
|
|
nomem_ev:
|
|
sctp_chunk_free(repl);
|
|
nomem_init:
|
|
sctp_association_free(new_asoc);
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Respond to a normal COOKIE ACK chunk.
|
|
* We are the side that is being asked for an association.
|
|
*
|
|
* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
|
|
* COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
|
|
* timer. It may also notify its ULP about the successful
|
|
* establishment of the association with a Communication Up
|
|
* notification (see Section 10).
|
|
*
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type, void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_ulpevent *ev;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Verify that the chunk length for the COOKIE-ACK is OK.
|
|
* If we don't do this, any bundled chunks may be junked.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Reset init error count upon receipt of COOKIE-ACK,
|
|
* to avoid problems with the managemement of this
|
|
* counter in stale cookie situations when a transition back
|
|
* from the COOKIE-ECHOED state to the COOKIE-WAIT
|
|
* state is performed.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
|
|
|
|
/* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* E) Upon reception of the COOKIE ACK, endpoint "A" will move
|
|
* from the COOKIE-ECHOED state to the ESTABLISHED state,
|
|
* stopping the T1-cookie timer.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_ESTABLISHED));
|
|
SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
|
|
SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
|
|
if (asoc->autoclose)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
|
|
/* It may also notify its ULP about the successful
|
|
* establishment of the association with a Communication Up
|
|
* notification (see Section 10).
|
|
*/
|
|
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
|
|
0, asoc->c.sinit_num_ostreams,
|
|
asoc->c.sinit_max_instreams,
|
|
NULL, GFP_ATOMIC);
|
|
|
|
if (!ev)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
|
|
|
|
/* Sockets API Draft Section 5.3.1.6
|
|
* When a peer sends a Adaptation Layer Indication parameter , SCTP
|
|
* delivers this notification to inform the application that of the
|
|
* peers requested adaptation layer.
|
|
*/
|
|
if (asoc->peer.adaptation_ind) {
|
|
ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
|
|
if (!ev)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ev));
|
|
}
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Generate and sendout a heartbeat packet. */
|
|
static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_transport *transport = (struct sctp_transport *) arg;
|
|
struct sctp_chunk *reply;
|
|
sctp_sender_hb_info_t hbinfo;
|
|
size_t paylen = 0;
|
|
|
|
hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
|
|
hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
|
|
hbinfo.daddr = transport->ipaddr;
|
|
hbinfo.sent_at = jiffies;
|
|
hbinfo.hb_nonce = transport->hb_nonce;
|
|
|
|
/* Send a heartbeat to our peer. */
|
|
paylen = sizeof(sctp_sender_hb_info_t);
|
|
reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
|
|
if (!reply)
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
|
|
/* Set rto_pending indicating that an RTT measurement
|
|
* is started with this heartbeat chunk.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
|
|
SCTP_TRANSPORT(transport));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* Generate a HEARTBEAT packet on the given transport. */
|
|
sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_transport *transport = (struct sctp_transport *) arg;
|
|
|
|
if (asoc->overall_error_count >= asoc->max_retrans) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
/* Section 3.3.5.
|
|
* The Sender-specific Heartbeat Info field should normally include
|
|
* information about the sender's current time when this HEARTBEAT
|
|
* chunk is sent and the destination transport address to which this
|
|
* HEARTBEAT is sent (see Section 8.3).
|
|
*/
|
|
|
|
if (transport->param_flags & SPP_HB_ENABLE) {
|
|
if (SCTP_DISPOSITION_NOMEM ==
|
|
sctp_sf_heartbeat(ep, asoc, type, arg,
|
|
commands))
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
|
|
/* Set transport error counter and association error counter
|
|
* when sending heartbeat.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
|
|
SCTP_TRANSPORT(transport));
|
|
}
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
|
|
SCTP_TRANSPORT(transport));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
|
|
SCTP_TRANSPORT(transport));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Process an heartbeat request.
|
|
*
|
|
* Section: 8.3 Path Heartbeat
|
|
* The receiver of the HEARTBEAT should immediately respond with a
|
|
* HEARTBEAT ACK that contains the Heartbeat Information field copied
|
|
* from the received HEARTBEAT chunk.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
* When receiving an SCTP packet, the endpoint MUST ensure that the
|
|
* value in the Verification Tag field of the received SCTP packet
|
|
* matches its own Tag. If the received Verification Tag value does not
|
|
* match the receiver's own tag value, the receiver shall silently
|
|
* discard the packet and shall not process it any further except for
|
|
* those cases listed in Section 8.5.1 below.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *reply;
|
|
size_t paylen = 0;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the HEARTBEAT chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* 8.3 The receiver of the HEARTBEAT should immediately
|
|
* respond with a HEARTBEAT ACK that contains the Heartbeat
|
|
* Information field copied from the received HEARTBEAT chunk.
|
|
*/
|
|
chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
|
|
paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
|
|
if (!pskb_pull(chunk->skb, paylen))
|
|
goto nomem;
|
|
|
|
reply = sctp_make_heartbeat_ack(asoc, chunk,
|
|
chunk->subh.hb_hdr, paylen);
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Process the returning HEARTBEAT ACK.
|
|
*
|
|
* Section: 8.3 Path Heartbeat
|
|
* Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
|
|
* should clear the error counter of the destination transport
|
|
* address to which the HEARTBEAT was sent, and mark the destination
|
|
* transport address as active if it is not so marked. The endpoint may
|
|
* optionally report to the upper layer when an inactive destination
|
|
* address is marked as active due to the reception of the latest
|
|
* HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
|
|
* clear the association overall error count as well (as defined
|
|
* in section 8.1).
|
|
*
|
|
* The receiver of the HEARTBEAT ACK should also perform an RTT
|
|
* measurement for that destination transport address using the time
|
|
* value carried in the HEARTBEAT ACK chunk.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
union sctp_addr from_addr;
|
|
struct sctp_transport *link;
|
|
sctp_sender_hb_info_t *hbinfo;
|
|
unsigned long max_interval;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
|
|
sizeof(sctp_sender_hb_info_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
|
|
/* Make sure that the length of the parameter is what we expect */
|
|
if (ntohs(hbinfo->param_hdr.length) !=
|
|
sizeof(sctp_sender_hb_info_t)) {
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
from_addr = hbinfo->daddr;
|
|
link = sctp_assoc_lookup_paddr(asoc, &from_addr);
|
|
|
|
/* This should never happen, but lets log it if so. */
|
|
if (unlikely(!link)) {
|
|
if (from_addr.sa.sa_family == AF_INET6) {
|
|
if (net_ratelimit())
|
|
printk(KERN_WARNING
|
|
"%s association %p could not find address %pI6\n",
|
|
__func__,
|
|
asoc,
|
|
&from_addr.v6.sin6_addr);
|
|
} else {
|
|
if (net_ratelimit())
|
|
printk(KERN_WARNING
|
|
"%s association %p could not find address %pI4\n",
|
|
__func__,
|
|
asoc,
|
|
&from_addr.v4.sin_addr.s_addr);
|
|
}
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* Validate the 64-bit random nonce. */
|
|
if (hbinfo->hb_nonce != link->hb_nonce)
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
|
|
max_interval = link->hbinterval + link->rto;
|
|
|
|
/* Check if the timestamp looks valid. */
|
|
if (time_after(hbinfo->sent_at, jiffies) ||
|
|
time_after(jiffies, hbinfo->sent_at + max_interval)) {
|
|
SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
|
|
"received for transport: %p\n",
|
|
__func__, link);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
|
|
* the HEARTBEAT should clear the error counter of the
|
|
* destination transport address to which the HEARTBEAT was
|
|
* sent and mark the destination transport address as active if
|
|
* it is not so marked.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* Helper function to send out an abort for the restart
|
|
* condition.
|
|
*/
|
|
static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
|
|
struct sctp_chunk *init,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
int len;
|
|
struct sctp_packet *pkt;
|
|
union sctp_addr_param *addrparm;
|
|
struct sctp_errhdr *errhdr;
|
|
struct sctp_endpoint *ep;
|
|
char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
|
|
struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
|
|
|
|
/* Build the error on the stack. We are way to malloc crazy
|
|
* throughout the code today.
|
|
*/
|
|
errhdr = (struct sctp_errhdr *)buffer;
|
|
addrparm = (union sctp_addr_param *)errhdr->variable;
|
|
|
|
/* Copy into a parm format. */
|
|
len = af->to_addr_param(ssa, addrparm);
|
|
len += sizeof(sctp_errhdr_t);
|
|
|
|
errhdr->cause = SCTP_ERROR_RESTART;
|
|
errhdr->length = htons(len);
|
|
|
|
/* Assign to the control socket. */
|
|
ep = sctp_sk((sctp_get_ctl_sock()))->ep;
|
|
|
|
/* Association is NULL since this may be a restart attack and we
|
|
* want to send back the attacker's vtag.
|
|
*/
|
|
pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
|
|
|
|
if (!pkt)
|
|
goto out;
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
|
|
/* Discard the rest of the inbound packet. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
|
|
|
|
out:
|
|
/* Even if there is no memory, treat as a failure so
|
|
* the packet will get dropped.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
/* A restart is occurring, check to make sure no new addresses
|
|
* are being added as we may be under a takeover attack.
|
|
*/
|
|
static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *init,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_transport *new_addr, *addr;
|
|
int found;
|
|
|
|
/* Implementor's Guide - Sectin 5.2.2
|
|
* ...
|
|
* Before responding the endpoint MUST check to see if the
|
|
* unexpected INIT adds new addresses to the association. If new
|
|
* addresses are added to the association, the endpoint MUST respond
|
|
* with an ABORT..
|
|
*/
|
|
|
|
/* Search through all current addresses and make sure
|
|
* we aren't adding any new ones.
|
|
*/
|
|
new_addr = NULL;
|
|
found = 0;
|
|
|
|
list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
|
|
transports) {
|
|
found = 0;
|
|
list_for_each_entry(addr, &asoc->peer.transport_addr_list,
|
|
transports) {
|
|
if (sctp_cmp_addr_exact(&new_addr->ipaddr,
|
|
&addr->ipaddr)) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!found)
|
|
break;
|
|
}
|
|
|
|
/* If a new address was added, ABORT the sender. */
|
|
if (!found && new_addr) {
|
|
sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
|
|
}
|
|
|
|
/* Return success if all addresses were found. */
|
|
return found;
|
|
}
|
|
|
|
/* Populate the verification/tie tags based on overlapping INIT
|
|
* scenario.
|
|
*
|
|
* Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
|
|
*/
|
|
static void sctp_tietags_populate(struct sctp_association *new_asoc,
|
|
const struct sctp_association *asoc)
|
|
{
|
|
switch (asoc->state) {
|
|
|
|
/* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
|
|
|
|
case SCTP_STATE_COOKIE_WAIT:
|
|
new_asoc->c.my_vtag = asoc->c.my_vtag;
|
|
new_asoc->c.my_ttag = asoc->c.my_vtag;
|
|
new_asoc->c.peer_ttag = 0;
|
|
break;
|
|
|
|
case SCTP_STATE_COOKIE_ECHOED:
|
|
new_asoc->c.my_vtag = asoc->c.my_vtag;
|
|
new_asoc->c.my_ttag = asoc->c.my_vtag;
|
|
new_asoc->c.peer_ttag = asoc->c.peer_vtag;
|
|
break;
|
|
|
|
/* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
|
|
* COOKIE-WAIT and SHUTDOWN-ACK-SENT
|
|
*/
|
|
default:
|
|
new_asoc->c.my_ttag = asoc->c.my_vtag;
|
|
new_asoc->c.peer_ttag = asoc->c.peer_vtag;
|
|
break;
|
|
}
|
|
|
|
/* Other parameters for the endpoint SHOULD be copied from the
|
|
* existing parameters of the association (e.g. number of
|
|
* outbound streams) into the INIT ACK and cookie.
|
|
*/
|
|
new_asoc->rwnd = asoc->rwnd;
|
|
new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
|
|
new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
|
|
new_asoc->c.initial_tsn = asoc->c.initial_tsn;
|
|
}
|
|
|
|
/*
|
|
* Compare vtag/tietag values to determine unexpected COOKIE-ECHO
|
|
* handling action.
|
|
*
|
|
* RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
|
|
*
|
|
* Returns value representing action to be taken. These action values
|
|
* correspond to Action/Description values in RFC 2960, Table 2.
|
|
*/
|
|
static char sctp_tietags_compare(struct sctp_association *new_asoc,
|
|
const struct sctp_association *asoc)
|
|
{
|
|
/* In this case, the peer may have restarted. */
|
|
if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
|
|
(asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
|
|
(asoc->c.my_vtag == new_asoc->c.my_ttag) &&
|
|
(asoc->c.peer_vtag == new_asoc->c.peer_ttag))
|
|
return 'A';
|
|
|
|
/* Collision case B. */
|
|
if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
|
|
((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
|
|
(0 == asoc->c.peer_vtag))) {
|
|
return 'B';
|
|
}
|
|
|
|
/* Collision case D. */
|
|
if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
|
|
(asoc->c.peer_vtag == new_asoc->c.peer_vtag))
|
|
return 'D';
|
|
|
|
/* Collision case C. */
|
|
if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
|
|
(asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
|
|
(0 == new_asoc->c.my_ttag) &&
|
|
(0 == new_asoc->c.peer_ttag))
|
|
return 'C';
|
|
|
|
/* No match to any of the special cases; discard this packet. */
|
|
return 'E';
|
|
}
|
|
|
|
/* Common helper routine for both duplicate and simulataneous INIT
|
|
* chunk handling.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_do_unexpected_init(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg, sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_disposition_t retval;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *repl;
|
|
struct sctp_association *new_asoc;
|
|
struct sctp_chunk *err_chunk;
|
|
struct sctp_packet *packet;
|
|
sctp_unrecognized_param_t *unk_param;
|
|
int len;
|
|
|
|
/* 6.10 Bundling
|
|
* An endpoint MUST NOT bundle INIT, INIT ACK or
|
|
* SHUTDOWN COMPLETE with any other chunks.
|
|
*
|
|
* IG Section 2.11.2
|
|
* Furthermore, we require that the receiver of an INIT chunk MUST
|
|
* enforce these rules by silently discarding an arriving packet
|
|
* with an INIT chunk that is bundled with other chunks.
|
|
*/
|
|
if (!chunk->singleton)
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
|
|
* Tag.
|
|
*/
|
|
if (chunk->sctp_hdr->vtag != 0)
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the INIT chunk has a valid length.
|
|
* In this case, we generate a protocol violation since we have
|
|
* an association established.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
/* Grab the INIT header. */
|
|
chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
|
|
|
|
/* Tag the variable length parameters. */
|
|
chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
|
|
|
|
/* Verify the INIT chunk before processing it. */
|
|
err_chunk = NULL;
|
|
if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
|
|
(sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
|
|
&err_chunk)) {
|
|
/* This chunk contains fatal error. It is to be discarded.
|
|
* Send an ABORT, with causes if there is any.
|
|
*/
|
|
if (err_chunk) {
|
|
packet = sctp_abort_pkt_new(ep, asoc, arg,
|
|
(__u8 *)(err_chunk->chunk_hdr) +
|
|
sizeof(sctp_chunkhdr_t),
|
|
ntohs(err_chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t));
|
|
|
|
if (packet) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
retval = SCTP_DISPOSITION_CONSUME;
|
|
} else {
|
|
retval = SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
goto cleanup;
|
|
} else {
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
|
|
commands);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Other parameters for the endpoint SHOULD be copied from the
|
|
* existing parameters of the association (e.g. number of
|
|
* outbound streams) into the INIT ACK and cookie.
|
|
* FIXME: We are copying parameters from the endpoint not the
|
|
* association.
|
|
*/
|
|
new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
|
|
if (!new_asoc)
|
|
goto nomem;
|
|
|
|
if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
|
|
sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
|
|
goto nomem;
|
|
|
|
/* In the outbound INIT ACK the endpoint MUST copy its current
|
|
* Verification Tag and Peers Verification tag into a reserved
|
|
* place (local tie-tag and per tie-tag) within the state cookie.
|
|
*/
|
|
if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
|
|
sctp_source(chunk),
|
|
(sctp_init_chunk_t *)chunk->chunk_hdr,
|
|
GFP_ATOMIC))
|
|
goto nomem;
|
|
|
|
/* Make sure no new addresses are being added during the
|
|
* restart. Do not do this check for COOKIE-WAIT state,
|
|
* since there are no peer addresses to check against.
|
|
* Upon return an ABORT will have been sent if needed.
|
|
*/
|
|
if (!sctp_state(asoc, COOKIE_WAIT)) {
|
|
if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
|
|
commands)) {
|
|
retval = SCTP_DISPOSITION_CONSUME;
|
|
goto nomem_retval;
|
|
}
|
|
}
|
|
|
|
sctp_tietags_populate(new_asoc, asoc);
|
|
|
|
/* B) "Z" shall respond immediately with an INIT ACK chunk. */
|
|
|
|
/* If there are errors need to be reported for unknown parameters,
|
|
* make sure to reserve enough room in the INIT ACK for them.
|
|
*/
|
|
len = 0;
|
|
if (err_chunk) {
|
|
len = ntohs(err_chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t);
|
|
}
|
|
|
|
repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
|
|
if (!repl)
|
|
goto nomem;
|
|
|
|
/* If there are errors need to be reported for unknown parameters,
|
|
* include them in the outgoing INIT ACK as "Unrecognized parameter"
|
|
* parameter.
|
|
*/
|
|
if (err_chunk) {
|
|
/* Get the "Unrecognized parameter" parameter(s) out of the
|
|
* ERROR chunk generated by sctp_verify_init(). Since the
|
|
* error cause code for "unknown parameter" and the
|
|
* "Unrecognized parameter" type is the same, we can
|
|
* construct the parameters in INIT ACK by copying the
|
|
* ERROR causes over.
|
|
*/
|
|
unk_param = (sctp_unrecognized_param_t *)
|
|
((__u8 *)(err_chunk->chunk_hdr) +
|
|
sizeof(sctp_chunkhdr_t));
|
|
/* Replace the cause code with the "Unrecognized parameter"
|
|
* parameter type.
|
|
*/
|
|
sctp_addto_chunk(repl, len, unk_param);
|
|
}
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
|
|
/*
|
|
* Note: After sending out INIT ACK with the State Cookie parameter,
|
|
* "Z" MUST NOT allocate any resources for this new association.
|
|
* Otherwise, "Z" will be vulnerable to resource attacks.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
retval = SCTP_DISPOSITION_CONSUME;
|
|
|
|
return retval;
|
|
|
|
nomem:
|
|
retval = SCTP_DISPOSITION_NOMEM;
|
|
nomem_retval:
|
|
if (new_asoc)
|
|
sctp_association_free(new_asoc);
|
|
cleanup:
|
|
if (err_chunk)
|
|
sctp_chunk_free(err_chunk);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Handle simultanous INIT.
|
|
* This means we started an INIT and then we got an INIT request from
|
|
* our peer.
|
|
*
|
|
* Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
|
|
* This usually indicates an initialization collision, i.e., each
|
|
* endpoint is attempting, at about the same time, to establish an
|
|
* association with the other endpoint.
|
|
*
|
|
* Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
|
|
* endpoint MUST respond with an INIT ACK using the same parameters it
|
|
* sent in its original INIT chunk (including its Verification Tag,
|
|
* unchanged). These original parameters are combined with those from the
|
|
* newly received INIT chunk. The endpoint shall also generate a State
|
|
* Cookie with the INIT ACK. The endpoint uses the parameters sent in its
|
|
* INIT to calculate the State Cookie.
|
|
*
|
|
* After that, the endpoint MUST NOT change its state, the T1-init
|
|
* timer shall be left running and the corresponding TCB MUST NOT be
|
|
* destroyed. The normal procedures for handling State Cookies when
|
|
* a TCB exists will resolve the duplicate INITs to a single association.
|
|
*
|
|
* For an endpoint that is in the COOKIE-ECHOED state it MUST populate
|
|
* its Tie-Tags with the Tag information of itself and its peer (see
|
|
* section 5.2.2 for a description of the Tie-Tags).
|
|
*
|
|
* Verification Tag: Not explicit, but an INIT can not have a valid
|
|
* verification tag, so we skip the check.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* Call helper to do the real work for both simulataneous and
|
|
* duplicate INIT chunk handling.
|
|
*/
|
|
return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Handle duplicated INIT messages. These are usually delayed
|
|
* restransmissions.
|
|
*
|
|
* Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
|
|
* COOKIE-ECHOED and COOKIE-WAIT
|
|
*
|
|
* Unless otherwise stated, upon reception of an unexpected INIT for
|
|
* this association, the endpoint shall generate an INIT ACK with a
|
|
* State Cookie. In the outbound INIT ACK the endpoint MUST copy its
|
|
* current Verification Tag and peer's Verification Tag into a reserved
|
|
* place within the state cookie. We shall refer to these locations as
|
|
* the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
|
|
* containing this INIT ACK MUST carry a Verification Tag value equal to
|
|
* the Initiation Tag found in the unexpected INIT. And the INIT ACK
|
|
* MUST contain a new Initiation Tag (randomly generated see Section
|
|
* 5.3.1). Other parameters for the endpoint SHOULD be copied from the
|
|
* existing parameters of the association (e.g. number of outbound
|
|
* streams) into the INIT ACK and cookie.
|
|
*
|
|
* After sending out the INIT ACK, the endpoint shall take no further
|
|
* actions, i.e., the existing association, including its current state,
|
|
* and the corresponding TCB MUST NOT be changed.
|
|
*
|
|
* Note: Only when a TCB exists and the association is not in a COOKIE-
|
|
* WAIT state are the Tie-Tags populated. For a normal association INIT
|
|
* (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
|
|
* set to 0 (indicating that no previous TCB existed). The INIT ACK and
|
|
* State Cookie are populated as specified in section 5.2.1.
|
|
*
|
|
* Verification Tag: Not specified, but an INIT has no way of knowing
|
|
* what the verification tag could be, so we ignore it.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* Call helper to do the real work for both simulataneous and
|
|
* duplicate INIT chunk handling.
|
|
*/
|
|
return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
|
|
/*
|
|
* Unexpected INIT-ACK handler.
|
|
*
|
|
* Section 5.2.3
|
|
* If an INIT ACK received by an endpoint in any state other than the
|
|
* COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
|
|
* An unexpected INIT ACK usually indicates the processing of an old or
|
|
* duplicated INIT chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg, sctp_cmd_seq_t *commands)
|
|
{
|
|
/* Per the above section, we'll discard the chunk if we have an
|
|
* endpoint. If this is an OOTB INIT-ACK, treat it as such.
|
|
*/
|
|
if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
|
|
return sctp_sf_ootb(ep, asoc, type, arg, commands);
|
|
else
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
|
|
*
|
|
* Section 5.2.4
|
|
* A) In this case, the peer may have restarted.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_association *new_asoc)
|
|
{
|
|
sctp_init_chunk_t *peer_init;
|
|
struct sctp_ulpevent *ev;
|
|
struct sctp_chunk *repl;
|
|
struct sctp_chunk *err;
|
|
sctp_disposition_t disposition;
|
|
|
|
/* new_asoc is a brand-new association, so these are not yet
|
|
* side effects--it is safe to run them here.
|
|
*/
|
|
peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
|
|
|
|
if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
|
|
sctp_source(chunk), peer_init,
|
|
GFP_ATOMIC))
|
|
goto nomem;
|
|
|
|
/* Make sure no new addresses are being added during the
|
|
* restart. Though this is a pretty complicated attack
|
|
* since you'd have to get inside the cookie.
|
|
*/
|
|
if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
|
|
* the peer has restarted (Action A), it MUST NOT setup a new
|
|
* association but instead resend the SHUTDOWN ACK and send an ERROR
|
|
* chunk with a "Cookie Received while Shutting Down" error cause to
|
|
* its peer.
|
|
*/
|
|
if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
|
|
disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
|
|
SCTP_ST_CHUNK(chunk->chunk_hdr->type),
|
|
chunk, commands);
|
|
if (SCTP_DISPOSITION_NOMEM == disposition)
|
|
goto nomem;
|
|
|
|
err = sctp_make_op_error(asoc, chunk,
|
|
SCTP_ERROR_COOKIE_IN_SHUTDOWN,
|
|
NULL, 0, 0);
|
|
if (err)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* For now, fail any unsent/unacked data. Consider the optional
|
|
* choice of resending of this data.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
|
|
|
|
repl = sctp_make_cookie_ack(new_asoc, chunk);
|
|
if (!repl)
|
|
goto nomem;
|
|
|
|
/* Report association restart to upper layer. */
|
|
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
|
|
new_asoc->c.sinit_num_ostreams,
|
|
new_asoc->c.sinit_max_instreams,
|
|
NULL, GFP_ATOMIC);
|
|
if (!ev)
|
|
goto nomem_ev;
|
|
|
|
/* Update the content of current association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem_ev:
|
|
sctp_chunk_free(repl);
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
|
|
*
|
|
* Section 5.2.4
|
|
* B) In this case, both sides may be attempting to start an association
|
|
* at about the same time but the peer endpoint started its INIT
|
|
* after responding to the local endpoint's INIT
|
|
*/
|
|
/* This case represents an initialization collision. */
|
|
static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_association *new_asoc)
|
|
{
|
|
sctp_init_chunk_t *peer_init;
|
|
struct sctp_chunk *repl;
|
|
|
|
/* new_asoc is a brand-new association, so these are not yet
|
|
* side effects--it is safe to run them here.
|
|
*/
|
|
peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
|
|
if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
|
|
sctp_source(chunk), peer_init,
|
|
GFP_ATOMIC))
|
|
goto nomem;
|
|
|
|
/* Update the content of current association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_ESTABLISHED));
|
|
SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
|
|
|
|
repl = sctp_make_cookie_ack(new_asoc, chunk);
|
|
if (!repl)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
|
|
/* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* D) IMPLEMENTATION NOTE: An implementation may choose to
|
|
* send the Communication Up notification to the SCTP user
|
|
* upon reception of a valid COOKIE ECHO chunk.
|
|
*
|
|
* Sadly, this needs to be implemented as a side-effect, because
|
|
* we are not guaranteed to have set the association id of the real
|
|
* association and so these notifications need to be delayed until
|
|
* the association id is allocated.
|
|
*/
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
|
|
|
|
/* Sockets API Draft Section 5.3.1.6
|
|
* When a peer sends a Adaptation Layer Indication parameter , SCTP
|
|
* delivers this notification to inform the application that of the
|
|
* peers requested adaptation layer.
|
|
*
|
|
* This also needs to be done as a side effect for the same reason as
|
|
* above.
|
|
*/
|
|
if (asoc->peer.adaptation_ind)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
|
|
*
|
|
* Section 5.2.4
|
|
* C) In this case, the local endpoint's cookie has arrived late.
|
|
* Before it arrived, the local endpoint sent an INIT and received an
|
|
* INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
|
|
* but a new tag of its own.
|
|
*/
|
|
/* This case represents an initialization collision. */
|
|
static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_association *new_asoc)
|
|
{
|
|
/* The cookie should be silently discarded.
|
|
* The endpoint SHOULD NOT change states and should leave
|
|
* any timers running.
|
|
*/
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
|
|
*
|
|
* Section 5.2.4
|
|
*
|
|
* D) When both local and remote tags match the endpoint should always
|
|
* enter the ESTABLISHED state, if it has not already done so.
|
|
*/
|
|
/* This case represents an initialization collision. */
|
|
static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_association *new_asoc)
|
|
{
|
|
struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
|
|
struct sctp_chunk *repl;
|
|
|
|
/* Clarification from Implementor's Guide:
|
|
* D) When both local and remote tags match the endpoint should
|
|
* enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
|
|
* It should stop any cookie timer that may be running and send
|
|
* a COOKIE ACK.
|
|
*/
|
|
|
|
/* Don't accidentally move back into established state. */
|
|
if (asoc->state < SCTP_STATE_ESTABLISHED) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_ESTABLISHED));
|
|
SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
|
|
SCTP_NULL());
|
|
|
|
/* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* D) IMPLEMENTATION NOTE: An implementation may choose
|
|
* to send the Communication Up notification to the
|
|
* SCTP user upon reception of a valid COOKIE
|
|
* ECHO chunk.
|
|
*/
|
|
ev = sctp_ulpevent_make_assoc_change(asoc, 0,
|
|
SCTP_COMM_UP, 0,
|
|
asoc->c.sinit_num_ostreams,
|
|
asoc->c.sinit_max_instreams,
|
|
NULL, GFP_ATOMIC);
|
|
if (!ev)
|
|
goto nomem;
|
|
|
|
/* Sockets API Draft Section 5.3.1.6
|
|
* When a peer sends a Adaptation Layer Indication parameter,
|
|
* SCTP delivers this notification to inform the application
|
|
* that of the peers requested adaptation layer.
|
|
*/
|
|
if (asoc->peer.adaptation_ind) {
|
|
ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
|
|
GFP_ATOMIC);
|
|
if (!ai_ev)
|
|
goto nomem;
|
|
|
|
}
|
|
}
|
|
|
|
repl = sctp_make_cookie_ack(new_asoc, chunk);
|
|
if (!repl)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
|
|
if (ev)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ev));
|
|
if (ai_ev)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ai_ev));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
if (ai_ev)
|
|
sctp_ulpevent_free(ai_ev);
|
|
if (ev)
|
|
sctp_ulpevent_free(ev);
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
|
|
* chunk was retransmitted and then delayed in the network.
|
|
*
|
|
* Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
|
|
*
|
|
* Verification Tag: None. Do cookie validation.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_disposition_t retval;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_association *new_asoc;
|
|
int error = 0;
|
|
char action;
|
|
struct sctp_chunk *err_chk_p;
|
|
|
|
/* Make sure that the chunk has a valid length from the protocol
|
|
* perspective. In this case check to make sure we have at least
|
|
* enough for the chunk header. Cookie length verification is
|
|
* done later.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* "Decode" the chunk. We have no optional parameters so we
|
|
* are in good shape.
|
|
*/
|
|
chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
|
|
if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
|
|
sizeof(sctp_chunkhdr_t)))
|
|
goto nomem;
|
|
|
|
/* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
|
|
* of a duplicate COOKIE ECHO match the Verification Tags of the
|
|
* current association, consider the State Cookie valid even if
|
|
* the lifespan is exceeded.
|
|
*/
|
|
new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
|
|
&err_chk_p);
|
|
|
|
/* FIXME:
|
|
* If the re-build failed, what is the proper error path
|
|
* from here?
|
|
*
|
|
* [We should abort the association. --piggy]
|
|
*/
|
|
if (!new_asoc) {
|
|
/* FIXME: Several errors are possible. A bad cookie should
|
|
* be silently discarded, but think about logging it too.
|
|
*/
|
|
switch (error) {
|
|
case -SCTP_IERROR_NOMEM:
|
|
goto nomem;
|
|
|
|
case -SCTP_IERROR_STALE_COOKIE:
|
|
sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
|
|
err_chk_p);
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
case -SCTP_IERROR_BAD_SIG:
|
|
default:
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
}
|
|
|
|
/* Compare the tie_tag in cookie with the verification tag of
|
|
* current association.
|
|
*/
|
|
action = sctp_tietags_compare(new_asoc, asoc);
|
|
|
|
switch (action) {
|
|
case 'A': /* Association restart. */
|
|
retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
|
|
new_asoc);
|
|
break;
|
|
|
|
case 'B': /* Collision case B. */
|
|
retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
|
|
new_asoc);
|
|
break;
|
|
|
|
case 'C': /* Collision case C. */
|
|
retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
|
|
new_asoc);
|
|
break;
|
|
|
|
case 'D': /* Collision case D. */
|
|
retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
|
|
new_asoc);
|
|
break;
|
|
|
|
default: /* Discard packet for all others. */
|
|
retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
break;
|
|
}
|
|
|
|
/* Delete the tempory new association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
|
|
return retval;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT. (SHUTDOWN-PENDING state)
|
|
*
|
|
* See sctp_sf_do_9_1_abort().
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_pending_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
if (!sctp_vtag_verify_either(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ABORT chunk has a valid length.
|
|
* Since this is an ABORT chunk, we have to discard it
|
|
* because of the following text:
|
|
* RFC 2960, Section 3.3.7
|
|
* If an endpoint receives an ABORT with a format error or for an
|
|
* association that doesn't exist, it MUST silently discard it.
|
|
* Becasue the length is "invalid", we can't really discard just
|
|
* as we do not know its true length. So, to be safe, discard the
|
|
* packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* ADD-IP: Special case for ABORT chunks
|
|
* F4) One special consideration is that ABORT Chunks arriving
|
|
* destined to the IP address being deleted MUST be
|
|
* ignored (see Section 5.3.1 for further details).
|
|
*/
|
|
if (SCTP_ADDR_DEL ==
|
|
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
|
|
return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT. (SHUTDOWN-SENT state)
|
|
*
|
|
* See sctp_sf_do_9_1_abort().
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
if (!sctp_vtag_verify_either(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ABORT chunk has a valid length.
|
|
* Since this is an ABORT chunk, we have to discard it
|
|
* because of the following text:
|
|
* RFC 2960, Section 3.3.7
|
|
* If an endpoint receives an ABORT with a format error or for an
|
|
* association that doesn't exist, it MUST silently discard it.
|
|
* Becasue the length is "invalid", we can't really discard just
|
|
* as we do not know its true length. So, to be safe, discard the
|
|
* packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* ADD-IP: Special case for ABORT chunks
|
|
* F4) One special consideration is that ABORT Chunks arriving
|
|
* destined to the IP address being deleted MUST be
|
|
* ignored (see Section 5.3.1 for further details).
|
|
*/
|
|
if (SCTP_ADDR_DEL ==
|
|
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
|
|
/* Stop the T2-shutdown timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
/* Stop the T5-shutdown guard timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT. (SHUTDOWN-ACK-SENT state)
|
|
*
|
|
* See sctp_sf_do_9_1_abort().
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* The same T2 timer, so we should be able to use
|
|
* common function with the SHUTDOWN-SENT state.
|
|
*/
|
|
return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Handle an Error received in COOKIE_ECHOED state.
|
|
*
|
|
* Only handle the error type of stale COOKIE Error, the other errors will
|
|
* be ignored.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_errhdr_t *err;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ERROR chunk has a valid length.
|
|
* The parameter walking depends on this as well.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Process the error here */
|
|
/* FUTURE FIXME: When PR-SCTP related and other optional
|
|
* parms are emitted, this will have to change to handle multiple
|
|
* errors.
|
|
*/
|
|
sctp_walk_errors(err, chunk->chunk_hdr) {
|
|
if (SCTP_ERROR_STALE_COOKIE == err->cause)
|
|
return sctp_sf_do_5_2_6_stale(ep, asoc, type,
|
|
arg, commands);
|
|
}
|
|
|
|
/* It is possible to have malformed error causes, and that
|
|
* will cause us to end the walk early. However, since
|
|
* we are discarding the packet, there should be no adverse
|
|
* affects.
|
|
*/
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Handle a Stale COOKIE Error
|
|
*
|
|
* Section: 5.2.6 Handle Stale COOKIE Error
|
|
* If the association is in the COOKIE-ECHOED state, the endpoint may elect
|
|
* one of the following three alternatives.
|
|
* ...
|
|
* 3) Send a new INIT chunk to the endpoint, adding a Cookie
|
|
* Preservative parameter requesting an extension to the lifetime of
|
|
* the State Cookie. When calculating the time extension, an
|
|
* implementation SHOULD use the RTT information measured based on the
|
|
* previous COOKIE ECHO / ERROR exchange, and should add no more
|
|
* than 1 second beyond the measured RTT, due to long State Cookie
|
|
* lifetimes making the endpoint more subject to a replay attack.
|
|
*
|
|
* Verification Tag: Not explicit, but safe to ignore.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
time_t stale;
|
|
sctp_cookie_preserve_param_t bht;
|
|
sctp_errhdr_t *err;
|
|
struct sctp_chunk *reply;
|
|
struct sctp_bind_addr *bp;
|
|
int attempts = asoc->init_err_counter + 1;
|
|
|
|
if (attempts > asoc->max_init_attempts) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
err = (sctp_errhdr_t *)(chunk->skb->data);
|
|
|
|
/* When calculating the time extension, an implementation
|
|
* SHOULD use the RTT information measured based on the
|
|
* previous COOKIE ECHO / ERROR exchange, and should add no
|
|
* more than 1 second beyond the measured RTT, due to long
|
|
* State Cookie lifetimes making the endpoint more subject to
|
|
* a replay attack.
|
|
* Measure of Staleness's unit is usec. (1/1000000 sec)
|
|
* Suggested Cookie Life-span Increment's unit is msec.
|
|
* (1/1000 sec)
|
|
* In general, if you use the suggested cookie life, the value
|
|
* found in the field of measure of staleness should be doubled
|
|
* to give ample time to retransmit the new cookie and thus
|
|
* yield a higher probability of success on the reattempt.
|
|
*/
|
|
stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
|
|
stale = (stale * 2) / 1000;
|
|
|
|
bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
|
|
bht.param_hdr.length = htons(sizeof(bht));
|
|
bht.lifespan_increment = htonl(stale);
|
|
|
|
/* Build that new INIT chunk. */
|
|
bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
|
|
reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
sctp_addto_chunk(reply, sizeof(bht), &bht);
|
|
|
|
/* Clear peer's init_tag cached in assoc as we are sending a new INIT */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
|
|
|
|
/* Stop pending T3-rtx and heartbeat timers */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
|
|
|
|
/* Delete non-primary peer ip addresses since we are transitioning
|
|
* back to the COOKIE-WAIT state
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
|
|
|
|
/* If we've sent any data bundled with COOKIE-ECHO we will need to
|
|
* resend
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
|
|
SCTP_TRANSPORT(asoc->peer.primary_path));
|
|
|
|
/* Cast away the const modifier, as we want to just
|
|
* rerun it through as a sideffect.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT.
|
|
*
|
|
* Section: 9.1
|
|
* After checking the Verification Tag, the receiving endpoint shall
|
|
* remove the association from its record, and shall report the
|
|
* termination to its upper layer.
|
|
*
|
|
* Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
|
|
* B) Rules for packet carrying ABORT:
|
|
*
|
|
* - The endpoint shall always fill in the Verification Tag field of the
|
|
* outbound packet with the destination endpoint's tag value if it
|
|
* is known.
|
|
*
|
|
* - If the ABORT is sent in response to an OOTB packet, the endpoint
|
|
* MUST follow the procedure described in Section 8.4.
|
|
*
|
|
* - The receiver MUST accept the packet if the Verification Tag
|
|
* matches either its own tag, OR the tag of its peer. Otherwise, the
|
|
* receiver MUST silently discard the packet and take no further
|
|
* action.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
if (!sctp_vtag_verify_either(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ABORT chunk has a valid length.
|
|
* Since this is an ABORT chunk, we have to discard it
|
|
* because of the following text:
|
|
* RFC 2960, Section 3.3.7
|
|
* If an endpoint receives an ABORT with a format error or for an
|
|
* association that doesn't exist, it MUST silently discard it.
|
|
* Becasue the length is "invalid", we can't really discard just
|
|
* as we do not know its true length. So, to be safe, discard the
|
|
* packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* ADD-IP: Special case for ABORT chunks
|
|
* F4) One special consideration is that ABORT Chunks arriving
|
|
* destined to the IP address being deleted MUST be
|
|
* ignored (see Section 5.3.1 for further details).
|
|
*/
|
|
if (SCTP_ADDR_DEL ==
|
|
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
|
|
return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
unsigned len;
|
|
__be16 error = SCTP_ERROR_NO_ERROR;
|
|
|
|
/* See if we have an error cause code in the chunk. */
|
|
len = ntohs(chunk->chunk_hdr->length);
|
|
if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
|
|
error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
|
|
/* ASSOC_FAILED will DELETE_TCB. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
|
|
return SCTP_DISPOSITION_ABORT;
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT. (COOKIE-WAIT state)
|
|
*
|
|
* See sctp_sf_do_9_1_abort() above.
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
unsigned len;
|
|
__be16 error = SCTP_ERROR_NO_ERROR;
|
|
|
|
if (!sctp_vtag_verify_either(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ABORT chunk has a valid length.
|
|
* Since this is an ABORT chunk, we have to discard it
|
|
* because of the following text:
|
|
* RFC 2960, Section 3.3.7
|
|
* If an endpoint receives an ABORT with a format error or for an
|
|
* association that doesn't exist, it MUST silently discard it.
|
|
* Becasue the length is "invalid", we can't really discard just
|
|
* as we do not know its true length. So, to be safe, discard the
|
|
* packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* See if we have an error cause code in the chunk. */
|
|
len = ntohs(chunk->chunk_hdr->length);
|
|
if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
|
|
error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
|
|
|
|
return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
|
|
chunk->transport);
|
|
}
|
|
|
|
/*
|
|
* Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
|
|
ENOPROTOOPT, asoc,
|
|
(struct sctp_transport *)arg);
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT. (COOKIE-ECHOED state)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* There is a single T1 timer, so we should be able to use
|
|
* common function with the COOKIE-WAIT state.
|
|
*/
|
|
return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Stop T1 timer and abort association with "INIT failed".
|
|
*
|
|
* This is common code called by several sctp_sf_*_abort() functions above.
|
|
*/
|
|
static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
|
|
__be16 error, int sk_err,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_transport *transport)
|
|
{
|
|
SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_CLOSED));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
|
|
/* CMD_INIT_FAILED will DELETE_TCB. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(error));
|
|
return SCTP_DISPOSITION_ABORT;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_do_9_2_shut
|
|
*
|
|
* Section: 9.2
|
|
* Upon the reception of the SHUTDOWN, the peer endpoint shall
|
|
* - enter the SHUTDOWN-RECEIVED state,
|
|
*
|
|
* - stop accepting new data from its SCTP user
|
|
*
|
|
* - verify, by checking the Cumulative TSN Ack field of the chunk,
|
|
* that all its outstanding DATA chunks have been received by the
|
|
* SHUTDOWN sender.
|
|
*
|
|
* Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
|
|
* send a SHUTDOWN in response to a ULP request. And should discard
|
|
* subsequent SHUTDOWN chunks.
|
|
*
|
|
* If there are still outstanding DATA chunks left, the SHUTDOWN
|
|
* receiver shall continue to follow normal data transmission
|
|
* procedures defined in Section 6 until all outstanding DATA chunks
|
|
* are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
|
|
* new data from its SCTP user.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_shutdownhdr_t *sdh;
|
|
sctp_disposition_t disposition;
|
|
struct sctp_ulpevent *ev;
|
|
__u32 ctsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SHUTDOWN chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk,
|
|
sizeof(struct sctp_shutdown_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Convert the elaborate header. */
|
|
sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
|
|
skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
|
|
chunk->subh.shutdown_hdr = sdh;
|
|
ctsn = ntohl(sdh->cum_tsn_ack);
|
|
|
|
if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
|
|
SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
|
|
SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* If Cumulative TSN Ack beyond the max tsn currently
|
|
* send, terminating the association and respond to the
|
|
* sender with an ABORT.
|
|
*/
|
|
if (!TSN_lt(ctsn, asoc->next_tsn))
|
|
return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
|
|
|
|
/* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
|
|
* When a peer sends a SHUTDOWN, SCTP delivers this notification to
|
|
* inform the application that it should cease sending data.
|
|
*/
|
|
ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
|
|
if (!ev) {
|
|
disposition = SCTP_DISPOSITION_NOMEM;
|
|
goto out;
|
|
}
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
|
|
|
|
/* Upon the reception of the SHUTDOWN, the peer endpoint shall
|
|
* - enter the SHUTDOWN-RECEIVED state,
|
|
* - stop accepting new data from its SCTP user
|
|
*
|
|
* [This is implicit in the new state.]
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
|
|
disposition = SCTP_DISPOSITION_CONSUME;
|
|
|
|
if (sctp_outq_is_empty(&asoc->outqueue)) {
|
|
disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
|
|
arg, commands);
|
|
}
|
|
|
|
if (SCTP_DISPOSITION_NOMEM == disposition)
|
|
goto out;
|
|
|
|
/* - verify, by checking the Cumulative TSN Ack field of the
|
|
* chunk, that all its outstanding DATA chunks have been
|
|
* received by the SHUTDOWN sender.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
|
|
SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
|
|
|
|
out:
|
|
return disposition;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_do_9_2_shut_ctsn
|
|
*
|
|
* Once an endpoint has reached the SHUTDOWN-RECEIVED state,
|
|
* it MUST NOT send a SHUTDOWN in response to a ULP request.
|
|
* The Cumulative TSN Ack of the received SHUTDOWN chunk
|
|
* MUST be processed.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_shutdownhdr_t *sdh;
|
|
__u32 ctsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SHUTDOWN chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk,
|
|
sizeof(struct sctp_shutdown_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
|
|
ctsn = ntohl(sdh->cum_tsn_ack);
|
|
|
|
if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
|
|
SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
|
|
SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* If Cumulative TSN Ack beyond the max tsn currently
|
|
* send, terminating the association and respond to the
|
|
* sender with an ABORT.
|
|
*/
|
|
if (!TSN_lt(ctsn, asoc->next_tsn))
|
|
return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
|
|
|
|
/* verify, by checking the Cumulative TSN Ack field of the
|
|
* chunk, that all its outstanding DATA chunks have been
|
|
* received by the SHUTDOWN sender.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
|
|
SCTP_BE32(sdh->cum_tsn_ack));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* RFC 2960 9.2
|
|
* If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
|
|
* (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
|
|
* transport addresses (either in the IP addresses or in the INIT chunk)
|
|
* that belong to this association, it should discard the INIT chunk and
|
|
* retransmit the SHUTDOWN ACK chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
|
|
struct sctp_chunk *reply;
|
|
|
|
/* Make sure that the chunk has a valid length */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Since we are not going to really process this INIT, there
|
|
* is no point in verifying chunk boundries. Just generate
|
|
* the SHUTDOWN ACK.
|
|
*/
|
|
reply = sctp_make_shutdown_ack(asoc, chunk);
|
|
if (NULL == reply)
|
|
goto nomem;
|
|
|
|
/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
|
|
* the T2-SHUTDOWN timer.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
|
|
|
|
/* and restart the T2-shutdown timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_do_ecn_cwr
|
|
*
|
|
* Section: Appendix A: Explicit Congestion Notification
|
|
*
|
|
* CWR:
|
|
*
|
|
* RFC 2481 details a specific bit for a sender to send in the header of
|
|
* its next outbound TCP segment to indicate to its peer that it has
|
|
* reduced its congestion window. This is termed the CWR bit. For
|
|
* SCTP the same indication is made by including the CWR chunk.
|
|
* This chunk contains one data element, i.e. the TSN number that
|
|
* was sent in the ECNE chunk. This element represents the lowest
|
|
* TSN number in the datagram that was originally marked with the
|
|
* CE bit.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_cwrhdr_t *cwr;
|
|
struct sctp_chunk *chunk = arg;
|
|
u32 lowest_tsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
cwr = (sctp_cwrhdr_t *) chunk->skb->data;
|
|
skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
|
|
|
|
lowest_tsn = ntohl(cwr->lowest_tsn);
|
|
|
|
/* Does this CWR ack the last sent congestion notification? */
|
|
if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
|
|
/* Stop sending ECNE. */
|
|
sctp_add_cmd_sf(commands,
|
|
SCTP_CMD_ECN_CWR,
|
|
SCTP_U32(lowest_tsn));
|
|
}
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_do_ecne
|
|
*
|
|
* Section: Appendix A: Explicit Congestion Notification
|
|
*
|
|
* ECN-Echo
|
|
*
|
|
* RFC 2481 details a specific bit for a receiver to send back in its
|
|
* TCP acknowledgements to notify the sender of the Congestion
|
|
* Experienced (CE) bit having arrived from the network. For SCTP this
|
|
* same indication is made by including the ECNE chunk. This chunk
|
|
* contains one data element, i.e. the lowest TSN associated with the IP
|
|
* datagram marked with the CE bit.....
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_ecnehdr_t *ecne;
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
ecne = (sctp_ecnehdr_t *) chunk->skb->data;
|
|
skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
|
|
|
|
/* If this is a newer ECNE than the last CWR packet we sent out */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
|
|
SCTP_U32(ntohl(ecne->lowest_tsn)));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Section: 6.2 Acknowledgement on Reception of DATA Chunks
|
|
*
|
|
* The SCTP endpoint MUST always acknowledge the reception of each valid
|
|
* DATA chunk.
|
|
*
|
|
* The guidelines on delayed acknowledgement algorithm specified in
|
|
* Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
|
|
* acknowledgement SHOULD be generated for at least every second packet
|
|
* (not every second DATA chunk) received, and SHOULD be generated within
|
|
* 200 ms of the arrival of any unacknowledged DATA chunk. In some
|
|
* situations it may be beneficial for an SCTP transmitter to be more
|
|
* conservative than the algorithms detailed in this document allow.
|
|
* However, an SCTP transmitter MUST NOT be more aggressive than the
|
|
* following algorithms allow.
|
|
*
|
|
* A SCTP receiver MUST NOT generate more than one SACK for every
|
|
* incoming packet, other than to update the offered window as the
|
|
* receiving application consumes new data.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_arg_t force = SCTP_NOFORCE();
|
|
int error;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
error = sctp_eat_data(asoc, chunk, commands );
|
|
switch (error) {
|
|
case SCTP_IERROR_NO_ERROR:
|
|
break;
|
|
case SCTP_IERROR_HIGH_TSN:
|
|
case SCTP_IERROR_BAD_STREAM:
|
|
SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
|
|
goto discard_noforce;
|
|
case SCTP_IERROR_DUP_TSN:
|
|
case SCTP_IERROR_IGNORE_TSN:
|
|
SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
|
|
goto discard_force;
|
|
case SCTP_IERROR_NO_DATA:
|
|
goto consume;
|
|
case SCTP_IERROR_PROTO_VIOLATION:
|
|
return sctp_sf_abort_violation(ep, asoc, chunk, commands,
|
|
(u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
|
|
force = SCTP_FORCE();
|
|
|
|
if (asoc->autoclose) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
}
|
|
|
|
/* If this is the last chunk in a packet, we need to count it
|
|
* toward sack generation. Note that we need to SACK every
|
|
* OTHER packet containing data chunks, EVEN IF WE DISCARD
|
|
* THEM. We elect to NOT generate SACK's if the chunk fails
|
|
* the verification tag test.
|
|
*
|
|
* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
|
|
*
|
|
* The SCTP endpoint MUST always acknowledge the reception of
|
|
* each valid DATA chunk.
|
|
*
|
|
* The guidelines on delayed acknowledgement algorithm
|
|
* specified in Section 4.2 of [RFC2581] SHOULD be followed.
|
|
* Specifically, an acknowledgement SHOULD be generated for at
|
|
* least every second packet (not every second DATA chunk)
|
|
* received, and SHOULD be generated within 200 ms of the
|
|
* arrival of any unacknowledged DATA chunk. In some
|
|
* situations it may be beneficial for an SCTP transmitter to
|
|
* be more conservative than the algorithms detailed in this
|
|
* document allow. However, an SCTP transmitter MUST NOT be
|
|
* more aggressive than the following algorithms allow.
|
|
*/
|
|
if (chunk->end_of_packet)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
discard_force:
|
|
/* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
|
|
*
|
|
* When a packet arrives with duplicate DATA chunk(s) and with
|
|
* no new DATA chunk(s), the endpoint MUST immediately send a
|
|
* SACK with no delay. If a packet arrives with duplicate
|
|
* DATA chunk(s) bundled with new DATA chunks, the endpoint
|
|
* MAY immediately send a SACK. Normally receipt of duplicate
|
|
* DATA chunks will occur when the original SACK chunk was lost
|
|
* and the peer's RTO has expired. The duplicate TSN number(s)
|
|
* SHOULD be reported in the SACK as duplicate.
|
|
*/
|
|
/* In our case, we split the MAY SACK advice up whether or not
|
|
* the last chunk is a duplicate.'
|
|
*/
|
|
if (chunk->end_of_packet)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
|
|
discard_noforce:
|
|
if (chunk->end_of_packet)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
|
|
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
consume:
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_eat_data_fast_4_4
|
|
*
|
|
* Section: 4 (4)
|
|
* (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
|
|
* DATA chunks without delay.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
int error;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
error = sctp_eat_data(asoc, chunk, commands );
|
|
switch (error) {
|
|
case SCTP_IERROR_NO_ERROR:
|
|
case SCTP_IERROR_HIGH_TSN:
|
|
case SCTP_IERROR_DUP_TSN:
|
|
case SCTP_IERROR_IGNORE_TSN:
|
|
case SCTP_IERROR_BAD_STREAM:
|
|
break;
|
|
case SCTP_IERROR_NO_DATA:
|
|
goto consume;
|
|
case SCTP_IERROR_PROTO_VIOLATION:
|
|
return sctp_sf_abort_violation(ep, asoc, chunk, commands,
|
|
(u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
/* Go a head and force a SACK, since we are shutting down. */
|
|
|
|
/* Implementor's Guide.
|
|
*
|
|
* While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
|
|
* respond to each received packet containing one or more DATA chunk(s)
|
|
* with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
|
|
*/
|
|
if (chunk->end_of_packet) {
|
|
/* We must delay the chunk creation since the cumulative
|
|
* TSN has not been updated yet.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
}
|
|
|
|
consume:
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Section: 6.2 Processing a Received SACK
|
|
* D) Any time a SACK arrives, the endpoint performs the following:
|
|
*
|
|
* i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
|
|
* then drop the SACK. Since Cumulative TSN Ack is monotonically
|
|
* increasing, a SACK whose Cumulative TSN Ack is less than the
|
|
* Cumulative TSN Ack Point indicates an out-of-order SACK.
|
|
*
|
|
* ii) Set rwnd equal to the newly received a_rwnd minus the number
|
|
* of bytes still outstanding after processing the Cumulative TSN Ack
|
|
* and the Gap Ack Blocks.
|
|
*
|
|
* iii) If the SACK is missing a TSN that was previously
|
|
* acknowledged via a Gap Ack Block (e.g., the data receiver
|
|
* reneged on the data), then mark the corresponding DATA chunk
|
|
* as available for retransmit: Mark it as missing for fast
|
|
* retransmit as described in Section 7.2.4 and if no retransmit
|
|
* timer is running for the destination address to which the DATA
|
|
* chunk was originally transmitted, then T3-rtx is started for
|
|
* that destination address.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
sctp_sackhdr_t *sackh;
|
|
__u32 ctsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SACK chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Pull the SACK chunk from the data buffer */
|
|
sackh = sctp_sm_pull_sack(chunk);
|
|
/* Was this a bogus SACK? */
|
|
if (!sackh)
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
chunk->subh.sack_hdr = sackh;
|
|
ctsn = ntohl(sackh->cum_tsn_ack);
|
|
|
|
/* i) If Cumulative TSN Ack is less than the Cumulative TSN
|
|
* Ack Point, then drop the SACK. Since Cumulative TSN
|
|
* Ack is monotonically increasing, a SACK whose
|
|
* Cumulative TSN Ack is less than the Cumulative TSN Ack
|
|
* Point indicates an out-of-order SACK.
|
|
*/
|
|
if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
|
|
SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
|
|
SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* If Cumulative TSN Ack beyond the max tsn currently
|
|
* send, terminating the association and respond to the
|
|
* sender with an ABORT.
|
|
*/
|
|
if (!TSN_lt(ctsn, asoc->next_tsn))
|
|
return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
|
|
|
|
/* Return this SACK for further processing. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
|
|
|
|
/* Note: We do the rest of the work on the PROCESS_SACK
|
|
* sideeffect.
|
|
*/
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Generate an ABORT in response to a packet.
|
|
*
|
|
* Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
|
|
*
|
|
* 8) The receiver should respond to the sender of the OOTB packet with
|
|
* an ABORT. When sending the ABORT, the receiver of the OOTB packet
|
|
* MUST fill in the Verification Tag field of the outbound packet
|
|
* with the value found in the Verification Tag field of the OOTB
|
|
* packet and set the T-bit in the Chunk Flags to indicate that the
|
|
* Verification Tag is reflected. After sending this ABORT, the
|
|
* receiver of the OOTB packet shall discard the OOTB packet and take
|
|
* no further action.
|
|
*
|
|
* Verification Tag:
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_packet *packet = NULL;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *abort;
|
|
|
|
packet = sctp_ootb_pkt_new(asoc, chunk);
|
|
|
|
if (packet) {
|
|
/* Make an ABORT. The T bit will be set if the asoc
|
|
* is NULL.
|
|
*/
|
|
abort = sctp_make_abort(asoc, chunk, 0);
|
|
if (!abort) {
|
|
sctp_ootb_pkt_free(packet);
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Reflect vtag if T-Bit is set */
|
|
if (sctp_test_T_bit(abort))
|
|
packet->vtag = ntohl(chunk->sctp_hdr->vtag);
|
|
|
|
/* Set the skb to the belonging sock for accounting. */
|
|
abort->skb->sk = ep->base.sk;
|
|
|
|
sctp_packet_append_chunk(packet, abort);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
|
|
sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
|
|
* event as ULP notification for each cause included in the chunk.
|
|
*
|
|
* API 5.3.1.3 - SCTP_REMOTE_ERROR
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ERROR chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
|
|
SCTP_CHUNK(chunk));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Process an inbound SHUTDOWN ACK.
|
|
*
|
|
* From Section 9.2:
|
|
* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
|
|
* stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
|
|
* peer, and remove all record of the association.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *reply;
|
|
struct sctp_ulpevent *ev;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
/* 10.2 H) SHUTDOWN COMPLETE notification
|
|
*
|
|
* When SCTP completes the shutdown procedures (section 9.2) this
|
|
* notification is passed to the upper layer.
|
|
*/
|
|
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
|
|
0, 0, 0, NULL, GFP_ATOMIC);
|
|
if (!ev)
|
|
goto nomem;
|
|
|
|
/* ...send a SHUTDOWN COMPLETE chunk to its peer, */
|
|
reply = sctp_make_shutdown_complete(asoc, chunk);
|
|
if (!reply)
|
|
goto nomem_chunk;
|
|
|
|
/* Do all the commands now (after allocation), so that we
|
|
* have consistent state if memory allocation failes
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
|
|
|
|
/* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
|
|
* stop the T2-shutdown timer,
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_CLOSED));
|
|
SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
|
|
/* ...and remove all record of the association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
|
|
nomem_chunk:
|
|
sctp_ulpevent_free(ev);
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
|
|
*
|
|
* 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
|
|
* respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
|
|
* When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
|
|
* packet must fill in the Verification Tag field of the outbound
|
|
* packet with the Verification Tag received in the SHUTDOWN ACK and
|
|
* set the T-bit in the Chunk Flags to indicate that the Verification
|
|
* Tag is reflected.
|
|
*
|
|
* 8) The receiver should respond to the sender of the OOTB packet with
|
|
* an ABORT. When sending the ABORT, the receiver of the OOTB packet
|
|
* MUST fill in the Verification Tag field of the outbound packet
|
|
* with the value found in the Verification Tag field of the OOTB
|
|
* packet and set the T-bit in the Chunk Flags to indicate that the
|
|
* Verification Tag is reflected. After sending this ABORT, the
|
|
* receiver of the OOTB packet shall discard the OOTB packet and take
|
|
* no further action.
|
|
*/
|
|
sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sk_buff *skb = chunk->skb;
|
|
sctp_chunkhdr_t *ch;
|
|
__u8 *ch_end;
|
|
int ootb_shut_ack = 0;
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
|
|
|
|
ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
|
|
do {
|
|
/* Report violation if the chunk is less then minimal */
|
|
if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Now that we know we at least have a chunk header,
|
|
* do things that are type appropriate.
|
|
*/
|
|
if (SCTP_CID_SHUTDOWN_ACK == ch->type)
|
|
ootb_shut_ack = 1;
|
|
|
|
/* RFC 2960, Section 3.3.7
|
|
* Moreover, under any circumstances, an endpoint that
|
|
* receives an ABORT MUST NOT respond to that ABORT by
|
|
* sending an ABORT of its own.
|
|
*/
|
|
if (SCTP_CID_ABORT == ch->type)
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Report violation if chunk len overflows */
|
|
ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
|
|
if (ch_end > skb_tail_pointer(skb))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
ch = (sctp_chunkhdr_t *) ch_end;
|
|
} while (ch_end < skb_tail_pointer(skb));
|
|
|
|
if (ootb_shut_ack)
|
|
return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
|
|
else
|
|
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Handle an "Out of the blue" SHUTDOWN ACK.
|
|
*
|
|
* Section: 8.4 5, sctpimpguide 2.41.
|
|
*
|
|
* 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
|
|
* respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
|
|
* When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
|
|
* packet must fill in the Verification Tag field of the outbound
|
|
* packet with the Verification Tag received in the SHUTDOWN ACK and
|
|
* set the T-bit in the Chunk Flags to indicate that the Verification
|
|
* Tag is reflected.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, type, arg, commands)
|
|
*
|
|
* Outputs
|
|
* (sctp_disposition_t)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_packet *packet = NULL;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *shut;
|
|
|
|
packet = sctp_ootb_pkt_new(asoc, chunk);
|
|
|
|
if (packet) {
|
|
/* Make an SHUTDOWN_COMPLETE.
|
|
* The T bit will be set if the asoc is NULL.
|
|
*/
|
|
shut = sctp_make_shutdown_complete(asoc, chunk);
|
|
if (!shut) {
|
|
sctp_ootb_pkt_free(packet);
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Reflect vtag if T-Bit is set */
|
|
if (sctp_test_T_bit(shut))
|
|
packet->vtag = ntohl(chunk->sctp_hdr->vtag);
|
|
|
|
/* Set the skb to the belonging sock for accounting. */
|
|
shut->skb->sk = ep->base.sk;
|
|
|
|
sctp_packet_append_chunk(packet, shut);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
|
|
/* If the chunk length is invalid, we don't want to process
|
|
* the reset of the packet.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* We need to discard the rest of the packet to prevent
|
|
* potential bomming attacks from additional bundled chunks.
|
|
* This is documented in SCTP Threats ID.
|
|
*/
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
|
|
*
|
|
* Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
|
|
* If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
|
|
* procedures in section 8.4 SHOULD be followed, in other words it
|
|
* should be treated as an Out Of The Blue packet.
|
|
* [This means that we do NOT check the Verification Tag on these
|
|
* chunks. --piggy ]
|
|
*
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
/* Although we do have an association in this case, it corresponds
|
|
* to a restarted association. So the packet is treated as an OOTB
|
|
* packet and the state function that handles OOTB SHUTDOWN_ACK is
|
|
* called with a NULL association.
|
|
*/
|
|
SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
|
|
|
|
return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
|
|
}
|
|
|
|
/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
|
|
sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type, void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *asconf_ack = NULL;
|
|
struct sctp_paramhdr *err_param = NULL;
|
|
sctp_addiphdr_t *hdr;
|
|
union sctp_addr_param *addr_param;
|
|
__u32 serial;
|
|
int length;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* ADD-IP: Section 4.1.1
|
|
* This chunk MUST be sent in an authenticated way by using
|
|
* the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
|
|
* is received unauthenticated it MUST be silently discarded as
|
|
* described in [I-D.ietf-tsvwg-sctp-auth].
|
|
*/
|
|
if (!sctp_addip_noauth && !chunk->auth)
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ASCONF ADDIP chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
hdr = (sctp_addiphdr_t *)chunk->skb->data;
|
|
serial = ntohl(hdr->serial);
|
|
|
|
addr_param = (union sctp_addr_param *)hdr->params;
|
|
length = ntohs(addr_param->p.length);
|
|
if (length < sizeof(sctp_paramhdr_t))
|
|
return sctp_sf_violation_paramlen(ep, asoc, type, arg,
|
|
(void *)addr_param, commands);
|
|
|
|
/* Verify the ASCONF chunk before processing it. */
|
|
if (!sctp_verify_asconf(asoc,
|
|
(sctp_paramhdr_t *)((void *)addr_param + length),
|
|
(void *)chunk->chunk_end,
|
|
&err_param))
|
|
return sctp_sf_violation_paramlen(ep, asoc, type, arg,
|
|
(void *)err_param, commands);
|
|
|
|
/* ADDIP 5.2 E1) Compare the value of the serial number to the value
|
|
* the endpoint stored in a new association variable
|
|
* 'Peer-Serial-Number'.
|
|
*/
|
|
if (serial == asoc->peer.addip_serial + 1) {
|
|
/* If this is the first instance of ASCONF in the packet,
|
|
* we can clean our old ASCONF-ACKs.
|
|
*/
|
|
if (!chunk->has_asconf)
|
|
sctp_assoc_clean_asconf_ack_cache(asoc);
|
|
|
|
/* ADDIP 5.2 E4) When the Sequence Number matches the next one
|
|
* expected, process the ASCONF as described below and after
|
|
* processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
|
|
* the response packet and cache a copy of it (in the event it
|
|
* later needs to be retransmitted).
|
|
*
|
|
* Essentially, do V1-V5.
|
|
*/
|
|
asconf_ack = sctp_process_asconf((struct sctp_association *)
|
|
asoc, chunk);
|
|
if (!asconf_ack)
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
} else if (serial < asoc->peer.addip_serial + 1) {
|
|
/* ADDIP 5.2 E2)
|
|
* If the value found in the Sequence Number is less than the
|
|
* ('Peer- Sequence-Number' + 1), simply skip to the next
|
|
* ASCONF, and include in the outbound response packet
|
|
* any previously cached ASCONF-ACK response that was
|
|
* sent and saved that matches the Sequence Number of the
|
|
* ASCONF. Note: It is possible that no cached ASCONF-ACK
|
|
* Chunk exists. This will occur when an older ASCONF
|
|
* arrives out of order. In such a case, the receiver
|
|
* should skip the ASCONF Chunk and not include ASCONF-ACK
|
|
* Chunk for that chunk.
|
|
*/
|
|
asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
|
|
if (!asconf_ack)
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
|
|
/* Reset the transport so that we select the correct one
|
|
* this time around. This is to make sure that we don't
|
|
* accidentally use a stale transport that's been removed.
|
|
*/
|
|
asconf_ack->transport = NULL;
|
|
} else {
|
|
/* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
|
|
* it must be either a stale packet or from an attacker.
|
|
*/
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/* ADDIP 5.2 E6) The destination address of the SCTP packet
|
|
* containing the ASCONF-ACK Chunks MUST be the source address of
|
|
* the SCTP packet that held the ASCONF Chunks.
|
|
*
|
|
* To do this properly, we'll set the destination address of the chunk
|
|
* and at the transmit time, will try look up the transport to use.
|
|
* Since ASCONFs may be bundled, the correct transport may not be
|
|
* created until we process the entire packet, thus this workaround.
|
|
*/
|
|
asconf_ack->dest = chunk->source;
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* ADDIP Section 4.3 General rules for address manipulation
|
|
* When building TLV parameters for the ASCONF Chunk that will add or
|
|
* delete IP addresses the D0 to D13 rules should be applied:
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type, void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *asconf_ack = arg;
|
|
struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
|
|
struct sctp_chunk *abort;
|
|
struct sctp_paramhdr *err_param = NULL;
|
|
sctp_addiphdr_t *addip_hdr;
|
|
__u32 sent_serial, rcvd_serial;
|
|
|
|
if (!sctp_vtag_verify(asconf_ack, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* ADD-IP, Section 4.1.2:
|
|
* This chunk MUST be sent in an authenticated way by using
|
|
* the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
|
|
* is received unauthenticated it MUST be silently discarded as
|
|
* described in [I-D.ietf-tsvwg-sctp-auth].
|
|
*/
|
|
if (!sctp_addip_noauth && !asconf_ack->auth)
|
|
return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the ADDIP chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
|
|
rcvd_serial = ntohl(addip_hdr->serial);
|
|
|
|
/* Verify the ASCONF-ACK chunk before processing it. */
|
|
if (!sctp_verify_asconf(asoc,
|
|
(sctp_paramhdr_t *)addip_hdr->params,
|
|
(void *)asconf_ack->chunk_end,
|
|
&err_param))
|
|
return sctp_sf_violation_paramlen(ep, asoc, type, arg,
|
|
(void *)err_param, commands);
|
|
|
|
if (last_asconf) {
|
|
addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
|
|
sent_serial = ntohl(addip_hdr->serial);
|
|
} else {
|
|
sent_serial = asoc->addip_serial - 1;
|
|
}
|
|
|
|
/* D0) If an endpoint receives an ASCONF-ACK that is greater than or
|
|
* equal to the next serial number to be used but no ASCONF chunk is
|
|
* outstanding the endpoint MUST ABORT the association. Note that a
|
|
* sequence number is greater than if it is no more than 2^^31-1
|
|
* larger than the current sequence number (using serial arithmetic).
|
|
*/
|
|
if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
|
|
!(asoc->addip_last_asconf)) {
|
|
abort = sctp_make_abort(asoc, asconf_ack,
|
|
sizeof(sctp_errhdr_t));
|
|
if (abort) {
|
|
sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(abort));
|
|
}
|
|
/* We are going to ABORT, so we might as well stop
|
|
* processing the rest of the chunks in the packet.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_ABORT;
|
|
}
|
|
|
|
if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
|
|
|
|
if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
|
|
asconf_ack)) {
|
|
/* Successfully processed ASCONF_ACK. We can
|
|
* release the next asconf if we have one.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
|
|
SCTP_NULL());
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
abort = sctp_make_abort(asoc, asconf_ack,
|
|
sizeof(sctp_errhdr_t));
|
|
if (abort) {
|
|
sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(abort));
|
|
}
|
|
/* We are going to ABORT, so we might as well stop
|
|
* processing the rest of the chunks in the packet.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_ABORT;
|
|
}
|
|
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/*
|
|
* PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
|
|
*
|
|
* When a FORWARD TSN chunk arrives, the data receiver MUST first update
|
|
* its cumulative TSN point to the value carried in the FORWARD TSN
|
|
* chunk, and then MUST further advance its cumulative TSN point locally
|
|
* if possible.
|
|
* After the above processing, the data receiver MUST stop reporting any
|
|
* missing TSNs earlier than or equal to the new cumulative TSN point.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_fwdtsn_hdr *fwdtsn_hdr;
|
|
struct sctp_fwdtsn_skip *skip;
|
|
__u16 len;
|
|
__u32 tsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* Make sure that the FORWARD_TSN chunk has valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
|
|
chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
|
|
len = ntohs(chunk->chunk_hdr->length);
|
|
len -= sizeof(struct sctp_chunkhdr);
|
|
skb_pull(chunk->skb, len);
|
|
|
|
tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
|
|
SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
|
|
|
|
/* The TSN is too high--silently discard the chunk and count on it
|
|
* getting retransmitted later.
|
|
*/
|
|
if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
|
|
goto discard_noforce;
|
|
|
|
/* Silently discard the chunk if stream-id is not valid */
|
|
sctp_walk_fwdtsn(skip, chunk) {
|
|
if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
|
|
goto discard_noforce;
|
|
}
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
|
|
if (len > sizeof(struct sctp_fwdtsn_hdr))
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
|
|
SCTP_CHUNK(chunk));
|
|
|
|
/* Count this as receiving DATA. */
|
|
if (asoc->autoclose) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
}
|
|
|
|
/* FIXME: For now send a SACK, but DATA processing may
|
|
* send another.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
discard_noforce:
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_fwdtsn_hdr *fwdtsn_hdr;
|
|
struct sctp_fwdtsn_skip *skip;
|
|
__u16 len;
|
|
__u32 tsn;
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* Make sure that the FORWARD_TSN chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
|
|
chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
|
|
len = ntohs(chunk->chunk_hdr->length);
|
|
len -= sizeof(struct sctp_chunkhdr);
|
|
skb_pull(chunk->skb, len);
|
|
|
|
tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
|
|
SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
|
|
|
|
/* The TSN is too high--silently discard the chunk and count on it
|
|
* getting retransmitted later.
|
|
*/
|
|
if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
|
|
goto gen_shutdown;
|
|
|
|
/* Silently discard the chunk if stream-id is not valid */
|
|
sctp_walk_fwdtsn(skip, chunk) {
|
|
if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
|
|
goto gen_shutdown;
|
|
}
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
|
|
if (len > sizeof(struct sctp_fwdtsn_hdr))
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
|
|
SCTP_CHUNK(chunk));
|
|
|
|
/* Go a head and force a SACK, since we are shutting down. */
|
|
gen_shutdown:
|
|
/* Implementor's Guide.
|
|
*
|
|
* While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
|
|
* respond to each received packet containing one or more DATA chunk(s)
|
|
* with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* SCTP-AUTH Section 6.3 Receving authenticated chukns
|
|
*
|
|
* The receiver MUST use the HMAC algorithm indicated in the HMAC
|
|
* Identifier field. If this algorithm was not specified by the
|
|
* receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
|
|
* during association setup, the AUTH chunk and all chunks after it MUST
|
|
* be discarded and an ERROR chunk SHOULD be sent with the error cause
|
|
* defined in Section 4.1.
|
|
*
|
|
* If an endpoint with no shared key receives a Shared Key Identifier
|
|
* other than 0, it MUST silently discard all authenticated chunks. If
|
|
* the endpoint has at least one endpoint pair shared key for the peer,
|
|
* it MUST use the key specified by the Shared Key Identifier if a
|
|
* key has been configured for that Shared Key Identifier. If no
|
|
* endpoint pair shared key has been configured for that Shared Key
|
|
* Identifier, all authenticated chunks MUST be silently discarded.
|
|
*
|
|
* Verification Tag: 8.5 Verification Tag [Normal verification]
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
struct sctp_chunk *chunk)
|
|
{
|
|
struct sctp_authhdr *auth_hdr;
|
|
struct sctp_hmac *hmac;
|
|
unsigned int sig_len;
|
|
__u16 key_id;
|
|
__u8 *save_digest;
|
|
__u8 *digest;
|
|
|
|
/* Pull in the auth header, so we can do some more verification */
|
|
auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
|
|
chunk->subh.auth_hdr = auth_hdr;
|
|
skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
|
|
|
|
/* Make sure that we suport the HMAC algorithm from the auth
|
|
* chunk.
|
|
*/
|
|
if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
|
|
return SCTP_IERROR_AUTH_BAD_HMAC;
|
|
|
|
/* Make sure that the provided shared key identifier has been
|
|
* configured
|
|
*/
|
|
key_id = ntohs(auth_hdr->shkey_id);
|
|
if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
|
|
return SCTP_IERROR_AUTH_BAD_KEYID;
|
|
|
|
|
|
/* Make sure that the length of the signature matches what
|
|
* we expect.
|
|
*/
|
|
sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
|
|
hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
|
|
if (sig_len != hmac->hmac_len)
|
|
return SCTP_IERROR_PROTO_VIOLATION;
|
|
|
|
/* Now that we've done validation checks, we can compute and
|
|
* verify the hmac. The steps involved are:
|
|
* 1. Save the digest from the chunk.
|
|
* 2. Zero out the digest in the chunk.
|
|
* 3. Compute the new digest
|
|
* 4. Compare saved and new digests.
|
|
*/
|
|
digest = auth_hdr->hmac;
|
|
skb_pull(chunk->skb, sig_len);
|
|
|
|
save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
|
|
if (!save_digest)
|
|
goto nomem;
|
|
|
|
memset(digest, 0, sig_len);
|
|
|
|
sctp_auth_calculate_hmac(asoc, chunk->skb,
|
|
(struct sctp_auth_chunk *)chunk->chunk_hdr,
|
|
GFP_ATOMIC);
|
|
|
|
/* Discard the packet if the digests do not match */
|
|
if (memcmp(save_digest, digest, sig_len)) {
|
|
kfree(save_digest);
|
|
return SCTP_IERROR_BAD_SIG;
|
|
}
|
|
|
|
kfree(save_digest);
|
|
chunk->auth = 1;
|
|
|
|
return SCTP_IERROR_NO_ERROR;
|
|
nomem:
|
|
return SCTP_IERROR_NOMEM;
|
|
}
|
|
|
|
sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_authhdr *auth_hdr;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *err_chunk;
|
|
sctp_ierror_t error;
|
|
|
|
/* Make sure that the peer has AUTH capable */
|
|
if (!asoc->peer.auth_capable)
|
|
return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
|
|
|
|
if (!sctp_vtag_verify(chunk, asoc)) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
|
|
SCTP_NULL());
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/* Make sure that the AUTH chunk has valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
|
|
error = sctp_sf_authenticate(ep, asoc, type, chunk);
|
|
switch (error) {
|
|
case SCTP_IERROR_AUTH_BAD_HMAC:
|
|
/* Generate the ERROR chunk and discard the rest
|
|
* of the packet
|
|
*/
|
|
err_chunk = sctp_make_op_error(asoc, chunk,
|
|
SCTP_ERROR_UNSUP_HMAC,
|
|
&auth_hdr->hmac_id,
|
|
sizeof(__u16), 0);
|
|
if (err_chunk) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err_chunk));
|
|
}
|
|
/* Fall Through */
|
|
case SCTP_IERROR_AUTH_BAD_KEYID:
|
|
case SCTP_IERROR_BAD_SIG:
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
break;
|
|
case SCTP_IERROR_PROTO_VIOLATION:
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
break;
|
|
case SCTP_IERROR_NOMEM:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
|
|
struct sctp_ulpevent *ev;
|
|
|
|
ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
|
|
SCTP_AUTH_NEWKEY, GFP_ATOMIC);
|
|
|
|
if (!ev)
|
|
return -ENOMEM;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
|
|
SCTP_ULPEVENT(ev));
|
|
}
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Process an unknown chunk.
|
|
*
|
|
* Section: 3.2. Also, 2.1 in the implementor's guide.
|
|
*
|
|
* Chunk Types are encoded such that the highest-order two bits specify
|
|
* the action that must be taken if the processing endpoint does not
|
|
* recognize the Chunk Type.
|
|
*
|
|
* 00 - Stop processing this SCTP packet and discard it, do not process
|
|
* any further chunks within it.
|
|
*
|
|
* 01 - Stop processing this SCTP packet and discard it, do not process
|
|
* any further chunks within it, and report the unrecognized
|
|
* chunk in an 'Unrecognized Chunk Type'.
|
|
*
|
|
* 10 - Skip this chunk and continue processing.
|
|
*
|
|
* 11 - Skip this chunk and continue processing, but report in an ERROR
|
|
* Chunk using the 'Unrecognized Chunk Type' cause of error.
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *unk_chunk = arg;
|
|
struct sctp_chunk *err_chunk;
|
|
sctp_chunkhdr_t *hdr;
|
|
|
|
SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
|
|
|
|
if (!sctp_vtag_verify(unk_chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the chunk has a valid length.
|
|
* Since we don't know the chunk type, we use a general
|
|
* chunkhdr structure to make a comparison.
|
|
*/
|
|
if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
switch (type.chunk & SCTP_CID_ACTION_MASK) {
|
|
case SCTP_CID_ACTION_DISCARD:
|
|
/* Discard the packet. */
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
break;
|
|
case SCTP_CID_ACTION_DISCARD_ERR:
|
|
/* Generate an ERROR chunk as response. */
|
|
hdr = unk_chunk->chunk_hdr;
|
|
err_chunk = sctp_make_op_error(asoc, unk_chunk,
|
|
SCTP_ERROR_UNKNOWN_CHUNK, hdr,
|
|
WORD_ROUND(ntohs(hdr->length)),
|
|
0);
|
|
if (err_chunk) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err_chunk));
|
|
}
|
|
|
|
/* Discard the packet. */
|
|
sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
break;
|
|
case SCTP_CID_ACTION_SKIP:
|
|
/* Skip the chunk. */
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
break;
|
|
case SCTP_CID_ACTION_SKIP_ERR:
|
|
/* Generate an ERROR chunk as response. */
|
|
hdr = unk_chunk->chunk_hdr;
|
|
err_chunk = sctp_make_op_error(asoc, unk_chunk,
|
|
SCTP_ERROR_UNKNOWN_CHUNK, hdr,
|
|
WORD_ROUND(ntohs(hdr->length)),
|
|
0);
|
|
if (err_chunk) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err_chunk));
|
|
}
|
|
/* Skip the chunk. */
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/*
|
|
* Discard the chunk.
|
|
*
|
|
* Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
|
|
* [Too numerous to mention...]
|
|
* Verification Tag: No verification needed.
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
/* Make sure that the chunk has a valid length.
|
|
* Since we don't know the chunk type, we use a general
|
|
* chunkhdr structure to make a comparison.
|
|
*/
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/*
|
|
* Discard the whole packet.
|
|
*
|
|
* Section: 8.4 2)
|
|
*
|
|
* 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
|
|
* silently discard the OOTB packet and take no further action.
|
|
*
|
|
* Verification Tag: No verification necessary
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
|
|
/*
|
|
* The other end is violating protocol.
|
|
*
|
|
* Section: Not specified
|
|
* Verification Tag: Not specified
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (asoc, reply_msg, msg_up, timers, counters)
|
|
*
|
|
* We simply tag the chunk as a violation. The state machine will log
|
|
* the violation and continue.
|
|
*/
|
|
sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
/* Make sure that the chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
|
|
return SCTP_DISPOSITION_VIOLATION;
|
|
}
|
|
|
|
/*
|
|
* Common function to handle a protocol violation.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_abort_violation(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands,
|
|
const __u8 *payload,
|
|
const size_t paylen)
|
|
{
|
|
struct sctp_packet *packet = NULL;
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_chunk *abort = NULL;
|
|
|
|
/* SCTP-AUTH, Section 6.3:
|
|
* It should be noted that if the receiver wants to tear
|
|
* down an association in an authenticated way only, the
|
|
* handling of malformed packets should not result in
|
|
* tearing down the association.
|
|
*
|
|
* This means that if we only want to abort associations
|
|
* in an authenticated way (i.e AUTH+ABORT), then we
|
|
* can't destroy this association just becuase the packet
|
|
* was malformed.
|
|
*/
|
|
if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
|
|
goto discard;
|
|
|
|
/* Make the abort chunk. */
|
|
abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
|
|
if (!abort)
|
|
goto nomem;
|
|
|
|
if (asoc) {
|
|
/* Treat INIT-ACK as a special case during COOKIE-WAIT. */
|
|
if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
|
|
!asoc->peer.i.init_tag) {
|
|
sctp_initack_chunk_t *initack;
|
|
|
|
initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
|
|
if (!sctp_chunk_length_valid(chunk,
|
|
sizeof(sctp_initack_chunk_t)))
|
|
abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
|
|
else {
|
|
unsigned int inittag;
|
|
|
|
inittag = ntohl(initack->init_hdr.init_tag);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
|
|
SCTP_U32(inittag));
|
|
}
|
|
}
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
|
|
if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNREFUSED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
|
|
} else {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
}
|
|
} else {
|
|
packet = sctp_ootb_pkt_new(asoc, chunk);
|
|
|
|
if (!packet)
|
|
goto nomem_pkt;
|
|
|
|
if (sctp_test_T_bit(abort))
|
|
packet->vtag = ntohl(chunk->sctp_hdr->vtag);
|
|
|
|
abort->skb->sk = ep->base.sk;
|
|
|
|
sctp_packet_append_chunk(packet, abort);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
}
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
|
|
discard:
|
|
sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
|
|
return SCTP_DISPOSITION_ABORT;
|
|
|
|
nomem_pkt:
|
|
sctp_chunk_free(abort);
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Handle a protocol violation when the chunk length is invalid.
|
|
* "Invalid" length is identified as smaller than the minimal length a
|
|
* given chunk can be. For example, a SACK chunk has invalid length
|
|
* if its length is set to be smaller than the size of sctp_sack_chunk_t.
|
|
*
|
|
* We inform the other end by sending an ABORT with a Protocol Violation
|
|
* error code.
|
|
*
|
|
* Section: Not specified
|
|
* Verification Tag: Nothing to do
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* Outputs
|
|
* (reply_msg, msg_up, counters)
|
|
*
|
|
* Generate an ABORT chunk and terminate the association.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_violation_chunklen(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
static const char err_str[]="The following chunk had invalid length:";
|
|
|
|
return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
|
|
sizeof(err_str));
|
|
}
|
|
|
|
/*
|
|
* Handle a protocol violation when the parameter length is invalid.
|
|
* "Invalid" length is identified as smaller than the minimal length a
|
|
* given parameter can be.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_violation_paramlen(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg, void *ext,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
struct sctp_paramhdr *param = ext;
|
|
struct sctp_chunk *abort = NULL;
|
|
|
|
if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
|
|
goto discard;
|
|
|
|
/* Make the abort chunk. */
|
|
abort = sctp_make_violation_paramlen(asoc, chunk, param);
|
|
if (!abort)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
|
|
discard:
|
|
sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
|
|
return SCTP_DISPOSITION_ABORT;
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Handle a protocol violation when the peer trying to advance the
|
|
* cumulative tsn ack to a point beyond the max tsn currently sent.
|
|
*
|
|
* We inform the other end by sending an ABORT with a Protocol Violation
|
|
* error code.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_violation_ctsn(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
|
|
|
|
return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
|
|
sizeof(err_str));
|
|
}
|
|
|
|
/* Handle protocol violation of an invalid chunk bundling. For example,
|
|
* when we have an association and we recieve bundled INIT-ACK, or
|
|
* SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
|
|
* statement from the specs. Additinally, there might be an attacker
|
|
* on the path and we may not want to continue this communication.
|
|
*/
|
|
static sctp_disposition_t sctp_sf_violation_chunk(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
static const char err_str[]="The following chunk violates protocol:";
|
|
|
|
if (!asoc)
|
|
return sctp_sf_violation(ep, asoc, type, arg, commands);
|
|
|
|
return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
|
|
sizeof(err_str));
|
|
}
|
|
/***************************************************************************
|
|
* These are the state functions for handling primitive (Section 10) events.
|
|
***************************************************************************/
|
|
/*
|
|
* sctp_sf_do_prm_asoc
|
|
*
|
|
* Section: 10.1 ULP-to-SCTP
|
|
* B) Associate
|
|
*
|
|
* Format: ASSOCIATE(local SCTP instance name, destination transport addr,
|
|
* outbound stream count)
|
|
* -> association id [,destination transport addr list] [,outbound stream
|
|
* count]
|
|
*
|
|
* This primitive allows the upper layer to initiate an association to a
|
|
* specific peer endpoint.
|
|
*
|
|
* The peer endpoint shall be specified by one of the transport addresses
|
|
* which defines the endpoint (see Section 1.4). If the local SCTP
|
|
* instance has not been initialized, the ASSOCIATE is considered an
|
|
* error.
|
|
* [This is not relevant for the kernel implementation since we do all
|
|
* initialization at boot time. It we hadn't initialized we wouldn't
|
|
* get anywhere near this code.]
|
|
*
|
|
* An association id, which is a local handle to the SCTP association,
|
|
* will be returned on successful establishment of the association. If
|
|
* SCTP is not able to open an SCTP association with the peer endpoint,
|
|
* an error is returned.
|
|
* [In the kernel implementation, the struct sctp_association needs to
|
|
* be created BEFORE causing this primitive to run.]
|
|
*
|
|
* Other association parameters may be returned, including the
|
|
* complete destination transport addresses of the peer as well as the
|
|
* outbound stream count of the local endpoint. One of the transport
|
|
* address from the returned destination addresses will be selected by
|
|
* the local endpoint as default primary path for sending SCTP packets
|
|
* to this peer. The returned "destination transport addr list" can
|
|
* be used by the ULP to change the default primary path or to force
|
|
* sending a packet to a specific transport address. [All of this
|
|
* stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
|
|
* function.]
|
|
*
|
|
* Mandatory attributes:
|
|
*
|
|
* o local SCTP instance name - obtained from the INITIALIZE operation.
|
|
* [This is the argument asoc.]
|
|
* o destination transport addr - specified as one of the transport
|
|
* addresses of the peer endpoint with which the association is to be
|
|
* established.
|
|
* [This is asoc->peer.active_path.]
|
|
* o outbound stream count - the number of outbound streams the ULP
|
|
* would like to open towards this peer endpoint.
|
|
* [BUG: This is not currently implemented.]
|
|
* Optional attributes:
|
|
*
|
|
* None.
|
|
*
|
|
* The return value is a disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *repl;
|
|
struct sctp_association* my_asoc;
|
|
|
|
/* The comment below says that we enter COOKIE-WAIT AFTER
|
|
* sending the INIT, but that doesn't actually work in our
|
|
* implementation...
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
|
|
|
|
/* RFC 2960 5.1 Normal Establishment of an Association
|
|
*
|
|
* A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
|
|
* must provide its Verification Tag (Tag_A) in the Initiate
|
|
* Tag field. Tag_A SHOULD be a random number in the range of
|
|
* 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
|
|
*/
|
|
|
|
repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
|
|
if (!repl)
|
|
goto nomem;
|
|
|
|
/* Cast away the const modifier, as we want to just
|
|
* rerun it through as a sideffect.
|
|
*/
|
|
my_asoc = (struct sctp_association *)asoc;
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
|
|
|
|
/* Choose transport for INIT. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
|
|
SCTP_CHUNK(repl));
|
|
|
|
/* After sending the INIT, "A" starts the T1-init timer and
|
|
* enters the COOKIE-WAIT state.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Process the SEND primitive.
|
|
*
|
|
* Section: 10.1 ULP-to-SCTP
|
|
* E) Send
|
|
*
|
|
* Format: SEND(association id, buffer address, byte count [,context]
|
|
* [,stream id] [,life time] [,destination transport address]
|
|
* [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
|
|
* -> result
|
|
*
|
|
* This is the main method to send user data via SCTP.
|
|
*
|
|
* Mandatory attributes:
|
|
*
|
|
* o association id - local handle to the SCTP association
|
|
*
|
|
* o buffer address - the location where the user message to be
|
|
* transmitted is stored;
|
|
*
|
|
* o byte count - The size of the user data in number of bytes;
|
|
*
|
|
* Optional attributes:
|
|
*
|
|
* o context - an optional 32 bit integer that will be carried in the
|
|
* sending failure notification to the ULP if the transportation of
|
|
* this User Message fails.
|
|
*
|
|
* o stream id - to indicate which stream to send the data on. If not
|
|
* specified, stream 0 will be used.
|
|
*
|
|
* o life time - specifies the life time of the user data. The user data
|
|
* will not be sent by SCTP after the life time expires. This
|
|
* parameter can be used to avoid efforts to transmit stale
|
|
* user messages. SCTP notifies the ULP if the data cannot be
|
|
* initiated to transport (i.e. sent to the destination via SCTP's
|
|
* send primitive) within the life time variable. However, the
|
|
* user data will be transmitted if SCTP has attempted to transmit a
|
|
* chunk before the life time expired.
|
|
*
|
|
* o destination transport address - specified as one of the destination
|
|
* transport addresses of the peer endpoint to which this packet
|
|
* should be sent. Whenever possible, SCTP should use this destination
|
|
* transport address for sending the packets, instead of the current
|
|
* primary path.
|
|
*
|
|
* o unorder flag - this flag, if present, indicates that the user
|
|
* would like the data delivered in an unordered fashion to the peer
|
|
* (i.e., the U flag is set to 1 on all DATA chunks carrying this
|
|
* message).
|
|
*
|
|
* o no-bundle flag - instructs SCTP not to bundle this user data with
|
|
* other outbound DATA chunks. SCTP MAY still bundle even when
|
|
* this flag is present, when faced with network congestion.
|
|
*
|
|
* o payload protocol-id - A 32 bit unsigned integer that is to be
|
|
* passed to the peer indicating the type of payload protocol data
|
|
* being transmitted. This value is passed as opaque data by SCTP.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_datamsg *msg = arg;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Process the SHUTDOWN primitive.
|
|
*
|
|
* Section: 10.1:
|
|
* C) Shutdown
|
|
*
|
|
* Format: SHUTDOWN(association id)
|
|
* -> result
|
|
*
|
|
* Gracefully closes an association. Any locally queued user data
|
|
* will be delivered to the peer. The association will be terminated only
|
|
* after the peer acknowledges all the SCTP packets sent. A success code
|
|
* will be returned on successful termination of the association. If
|
|
* attempting to terminate the association results in a failure, an error
|
|
* code shall be returned.
|
|
*
|
|
* Mandatory attributes:
|
|
*
|
|
* o association id - local handle to the SCTP association
|
|
*
|
|
* Optional attributes:
|
|
*
|
|
* None.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
int disposition;
|
|
|
|
/* From 9.2 Shutdown of an Association
|
|
* Upon receipt of the SHUTDOWN primitive from its upper
|
|
* layer, the endpoint enters SHUTDOWN-PENDING state and
|
|
* remains there until all outstanding data has been
|
|
* acknowledged by its peer. The endpoint accepts no new data
|
|
* from its upper layer, but retransmits data to the far end
|
|
* if necessary to fill gaps.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
|
|
|
|
disposition = SCTP_DISPOSITION_CONSUME;
|
|
if (sctp_outq_is_empty(&asoc->outqueue)) {
|
|
disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
|
|
arg, commands);
|
|
}
|
|
return disposition;
|
|
}
|
|
|
|
/*
|
|
* Process the ABORT primitive.
|
|
*
|
|
* Section: 10.1:
|
|
* C) Abort
|
|
*
|
|
* Format: Abort(association id [, cause code])
|
|
* -> result
|
|
*
|
|
* Ungracefully closes an association. Any locally queued user data
|
|
* will be discarded and an ABORT chunk is sent to the peer. A success code
|
|
* will be returned on successful abortion of the association. If
|
|
* attempting to abort the association results in a failure, an error
|
|
* code shall be returned.
|
|
*
|
|
* Mandatory attributes:
|
|
*
|
|
* o association id - local handle to the SCTP association
|
|
*
|
|
* Optional attributes:
|
|
*
|
|
* o cause code - reason of the abort to be passed to the peer
|
|
*
|
|
* None.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_1_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* From 9.1 Abort of an Association
|
|
* Upon receipt of the ABORT primitive from its upper
|
|
* layer, the endpoint enters CLOSED state and
|
|
* discard all outstanding data has been
|
|
* acknowledged by its peer. The endpoint accepts no new data
|
|
* from its upper layer, but retransmits data to the far end
|
|
* if necessary to fill gaps.
|
|
*/
|
|
struct sctp_chunk *abort = arg;
|
|
sctp_disposition_t retval;
|
|
|
|
retval = SCTP_DISPOSITION_CONSUME;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
|
|
|
|
/* Even if we can't send the ABORT due to low memory delete the
|
|
* TCB. This is a departure from our typical NOMEM handling.
|
|
*/
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
/* Delete the established association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_USER_ABORT));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/* We tried an illegal operation on an association which is closed. */
|
|
sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* We tried an illegal operation on an association which is shutting
|
|
* down.
|
|
*/
|
|
sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
|
|
SCTP_ERROR(-ESHUTDOWN));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* sctp_cookie_wait_prm_shutdown
|
|
*
|
|
* Section: 4 Note: 2
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explicitly address this issue, but is the route through the
|
|
* state table when someone issues a shutdown while in COOKIE_WAIT state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_CLOSED));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
|
|
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
/*
|
|
* sctp_cookie_echoed_prm_shutdown
|
|
*
|
|
* Section: 4 Note: 2
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explcitly address this issue, but is the route through the
|
|
* state table when someone issues a shutdown while in COOKIE_ECHOED state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg, sctp_cmd_seq_t *commands)
|
|
{
|
|
/* There is a single T1 timer, so we should be able to use
|
|
* common function with the COOKIE-WAIT state.
|
|
*/
|
|
return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_cookie_wait_prm_abort
|
|
*
|
|
* Section: 4 Note: 2
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explicitly address this issue, but is the route through the
|
|
* state table when someone issues an abort while in COOKIE_WAIT state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *abort = arg;
|
|
sctp_disposition_t retval;
|
|
|
|
/* Stop T1-init timer */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
retval = SCTP_DISPOSITION_CONSUME;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_CLOSED));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
|
|
/* Even if we can't send the ABORT due to low memory delete the
|
|
* TCB. This is a departure from our typical NOMEM handling.
|
|
*/
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNREFUSED));
|
|
/* Delete the established association. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_USER_ABORT));
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_cookie_echoed_prm_abort
|
|
*
|
|
* Section: 4 Note: 3
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explcitly address this issue, but is the route through the
|
|
* state table when someone issues an abort while in COOKIE_ECHOED state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* There is a single T1 timer, so we should be able to use
|
|
* common function with the COOKIE-WAIT state.
|
|
*/
|
|
return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_shutdown_pending_prm_abort
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explicitly address this issue, but is the route through the
|
|
* state table when someone issues an abort while in SHUTDOWN-PENDING state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* Stop the T5-shutdown guard timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_shutdown_sent_prm_abort
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explicitly address this issue, but is the route through the
|
|
* state table when someone issues an abort while in SHUTDOWN-SENT state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* Stop the T2-shutdown timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
/* Stop the T5-shutdown guard timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_cookie_echoed_prm_abort
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* The RFC does not explcitly address this issue, but is the route through the
|
|
* state table when someone issues an abort while in COOKIE_ECHOED state.
|
|
*
|
|
* Outputs
|
|
* (timers)
|
|
*/
|
|
sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
/* The same T2 timer, so we should be able to use
|
|
* common function with the SHUTDOWN-SENT state.
|
|
*/
|
|
return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
|
|
}
|
|
|
|
/*
|
|
* Process the REQUESTHEARTBEAT primitive
|
|
*
|
|
* 10.1 ULP-to-SCTP
|
|
* J) Request Heartbeat
|
|
*
|
|
* Format: REQUESTHEARTBEAT(association id, destination transport address)
|
|
*
|
|
* -> result
|
|
*
|
|
* Instructs the local endpoint to perform a HeartBeat on the specified
|
|
* destination transport address of the given association. The returned
|
|
* result should indicate whether the transmission of the HEARTBEAT
|
|
* chunk to the destination address is successful.
|
|
*
|
|
* Mandatory attributes:
|
|
*
|
|
* o association id - local handle to the SCTP association
|
|
*
|
|
* o destination transport address - the transport address of the
|
|
* association on which a heartbeat should be issued.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
|
|
(struct sctp_transport *)arg, commands))
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
|
|
/*
|
|
* RFC 2960 (bis), section 8.3
|
|
*
|
|
* D) Request an on-demand HEARTBEAT on a specific destination
|
|
* transport address of a given association.
|
|
*
|
|
* The endpoint should increment the respective error counter of
|
|
* the destination transport address each time a HEARTBEAT is sent
|
|
* to that address and not acknowledged within one RTO.
|
|
*
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
|
|
SCTP_TRANSPORT(arg));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* ADDIP Section 4.1 ASCONF Chunk Procedures
|
|
* When an endpoint has an ASCONF signaled change to be sent to the
|
|
* remote endpoint it should do A1 to A9
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = arg;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Ignore the primitive event
|
|
*
|
|
* The return value is the disposition of the primitive.
|
|
*/
|
|
sctp_disposition_t sctp_sf_ignore_primitive(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/***************************************************************************
|
|
* These are the state functions for the OTHER events.
|
|
***************************************************************************/
|
|
|
|
/*
|
|
* Start the shutdown negotiation.
|
|
*
|
|
* From Section 9.2:
|
|
* Once all its outstanding data has been acknowledged, the endpoint
|
|
* shall send a SHUTDOWN chunk to its peer including in the Cumulative
|
|
* TSN Ack field the last sequential TSN it has received from the peer.
|
|
* It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
|
|
* state. If the timer expires, the endpoint must re-send the SHUTDOWN
|
|
* with the updated last sequential TSN received from its peer.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *reply;
|
|
|
|
/* Once all its outstanding data has been acknowledged, the
|
|
* endpoint shall send a SHUTDOWN chunk to its peer including
|
|
* in the Cumulative TSN Ack field the last sequential TSN it
|
|
* has received from the peer.
|
|
*/
|
|
reply = sctp_make_shutdown(asoc, NULL);
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
/* Set the transport for the SHUTDOWN chunk and the timeout for the
|
|
* T2-shutdown timer.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
|
|
|
|
/* It shall then start the T2-shutdown timer */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
/* RFC 4960 Section 9.2
|
|
* The sender of the SHUTDOWN MAY also start an overall guard timer
|
|
* 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
|
|
|
|
if (asoc->autoclose)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
|
|
/* and enter the SHUTDOWN-SENT state. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
|
|
|
|
/* sctp-implguide 2.10 Issues with Heartbeating and failover
|
|
*
|
|
* HEARTBEAT ... is discontinued after sending either SHUTDOWN
|
|
* or SHUTDOWN-ACK.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Generate a SHUTDOWN ACK now that everything is SACK'd.
|
|
*
|
|
* From Section 9.2:
|
|
*
|
|
* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
|
|
* shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
|
|
* entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
|
|
* endpoint must re-send the SHUTDOWN ACK.
|
|
*
|
|
* The return value is the disposition.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
|
|
struct sctp_chunk *reply;
|
|
|
|
/* There are 2 ways of getting here:
|
|
* 1) called in response to a SHUTDOWN chunk
|
|
* 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
|
|
*
|
|
* For the case (2), the arg parameter is set to NULL. We need
|
|
* to check that we have a chunk before accessing it's fields.
|
|
*/
|
|
if (chunk) {
|
|
if (!sctp_vtag_verify(chunk, asoc))
|
|
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
|
|
|
|
/* Make sure that the SHUTDOWN chunk has a valid length. */
|
|
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
|
|
return sctp_sf_violation_chunklen(ep, asoc, type, arg,
|
|
commands);
|
|
}
|
|
|
|
/* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
|
|
* shall send a SHUTDOWN ACK ...
|
|
*/
|
|
reply = sctp_make_shutdown_ack(asoc, chunk);
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
|
|
* the T2-shutdown timer.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
|
|
|
|
/* and start/restart a T2-shutdown timer of its own, */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
|
|
if (asoc->autoclose)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
|
|
|
|
/* Enter the SHUTDOWN-ACK-SENT state. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
|
|
|
|
/* sctp-implguide 2.10 Issues with Heartbeating and failover
|
|
*
|
|
* HEARTBEAT ... is discontinued after sending either SHUTDOWN
|
|
* or SHUTDOWN-ACK.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* Ignore the event defined as other
|
|
*
|
|
* The return value is the disposition of the event.
|
|
*/
|
|
sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
|
|
return SCTP_DISPOSITION_DISCARD;
|
|
}
|
|
|
|
/************************************************************
|
|
* These are the state functions for handling timeout events.
|
|
************************************************************/
|
|
|
|
/*
|
|
* RTX Timeout
|
|
*
|
|
* Section: 6.3.3 Handle T3-rtx Expiration
|
|
*
|
|
* Whenever the retransmission timer T3-rtx expires for a destination
|
|
* address, do the following:
|
|
* [See below]
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_transport *transport = arg;
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
|
|
|
|
if (asoc->overall_error_count >= asoc->max_retrans) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
/* E1) For the destination address for which the timer
|
|
* expires, adjust its ssthresh with rules defined in Section
|
|
* 7.2.3 and set the cwnd <- MTU.
|
|
*/
|
|
|
|
/* E2) For the destination address for which the timer
|
|
* expires, set RTO <- RTO * 2 ("back off the timer"). The
|
|
* maximum value discussed in rule C7 above (RTO.max) may be
|
|
* used to provide an upper bound to this doubling operation.
|
|
*/
|
|
|
|
/* E3) Determine how many of the earliest (i.e., lowest TSN)
|
|
* outstanding DATA chunks for the address for which the
|
|
* T3-rtx has expired will fit into a single packet, subject
|
|
* to the MTU constraint for the path corresponding to the
|
|
* destination transport address to which the retransmission
|
|
* is being sent (this may be different from the address for
|
|
* which the timer expires [see Section 6.4]). Call this
|
|
* value K. Bundle and retransmit those K DATA chunks in a
|
|
* single packet to the destination endpoint.
|
|
*
|
|
* Note: Any DATA chunks that were sent to the address for
|
|
* which the T3-rtx timer expired but did not fit in one MTU
|
|
* (rule E3 above), should be marked for retransmission and
|
|
* sent as soon as cwnd allows (normally when a SACK arrives).
|
|
*/
|
|
|
|
/* Do some failure management (Section 8.2). */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
|
|
|
|
/* NB: Rules E4 and F1 are implicit in R1. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* Generate delayed SACK on timeout
|
|
*
|
|
* Section: 6.2 Acknowledgement on Reception of DATA Chunks
|
|
*
|
|
* The guidelines on delayed acknowledgement algorithm specified in
|
|
* Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
|
|
* acknowledgement SHOULD be generated for at least every second packet
|
|
* (not every second DATA chunk) received, and SHOULD be generated
|
|
* within 200 ms of the arrival of any unacknowledged DATA chunk. In
|
|
* some situations it may be beneficial for an SCTP transmitter to be
|
|
* more conservative than the algorithms detailed in this document
|
|
* allow. However, an SCTP transmitter MUST NOT be more aggressive than
|
|
* the following algorithms allow.
|
|
*/
|
|
sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_t1_init_timer_expire
|
|
*
|
|
* Section: 4 Note: 2
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* RFC 2960 Section 4 Notes
|
|
* 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
|
|
* and re-start the T1-init timer without changing state. This MUST
|
|
* be repeated up to 'Max.Init.Retransmits' times. After that, the
|
|
* endpoint MUST abort the initialization process and report the
|
|
* error to SCTP user.
|
|
*
|
|
* Outputs
|
|
* (timers, events)
|
|
*
|
|
*/
|
|
sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *repl = NULL;
|
|
struct sctp_bind_addr *bp;
|
|
int attempts = asoc->init_err_counter + 1;
|
|
|
|
SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
|
|
SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
|
|
|
|
if (attempts <= asoc->max_init_attempts) {
|
|
bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
|
|
repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
|
|
if (!repl)
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
|
|
/* Choose transport for INIT. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
|
|
SCTP_CHUNK(repl));
|
|
|
|
/* Issue a sideeffect to do the needed accounting. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
} else {
|
|
SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
|
|
" max_init_attempts: %d\n",
|
|
attempts, asoc->max_init_attempts);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/*
|
|
* sctp_sf_t1_cookie_timer_expire
|
|
*
|
|
* Section: 4 Note: 2
|
|
* Verification Tag:
|
|
* Inputs
|
|
* (endpoint, asoc)
|
|
*
|
|
* RFC 2960 Section 4 Notes
|
|
* 3) If the T1-cookie timer expires, the endpoint MUST retransmit
|
|
* COOKIE ECHO and re-start the T1-cookie timer without changing
|
|
* state. This MUST be repeated up to 'Max.Init.Retransmits' times.
|
|
* After that, the endpoint MUST abort the initialization process and
|
|
* report the error to SCTP user.
|
|
*
|
|
* Outputs
|
|
* (timers, events)
|
|
*
|
|
*/
|
|
sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *repl = NULL;
|
|
int attempts = asoc->init_err_counter + 1;
|
|
|
|
SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
|
|
SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
|
|
|
|
if (attempts <= asoc->max_init_attempts) {
|
|
repl = sctp_make_cookie_echo(asoc, NULL);
|
|
if (!repl)
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
|
|
SCTP_CHUNK(repl));
|
|
/* Issue a sideeffect to do the needed accounting. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
|
|
} else {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
|
|
* with the updated last sequential TSN received from its peer.
|
|
*
|
|
* An endpoint should limit the number of retransmissions of the
|
|
* SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
|
|
* If this threshold is exceeded the endpoint should destroy the TCB and
|
|
* MUST report the peer endpoint unreachable to the upper layer (and
|
|
* thus the association enters the CLOSED state). The reception of any
|
|
* packet from its peer (i.e. as the peer sends all of its queued DATA
|
|
* chunks) should clear the endpoint's retransmission count and restart
|
|
* the T2-Shutdown timer, giving its peer ample opportunity to transmit
|
|
* all of its queued DATA chunks that have not yet been sent.
|
|
*/
|
|
sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *reply = NULL;
|
|
|
|
SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
|
|
SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
|
|
|
|
((struct sctp_association *)asoc)->shutdown_retries++;
|
|
|
|
if (asoc->overall_error_count >= asoc->max_retrans) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
/* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
}
|
|
|
|
switch (asoc->state) {
|
|
case SCTP_STATE_SHUTDOWN_SENT:
|
|
reply = sctp_make_shutdown(asoc, NULL);
|
|
break;
|
|
|
|
case SCTP_STATE_SHUTDOWN_ACK_SENT:
|
|
reply = sctp_make_shutdown_ack(asoc, NULL);
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
break;
|
|
}
|
|
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
/* Do some failure management (Section 8.2).
|
|
* If we remove the transport an SHUTDOWN was last sent to, don't
|
|
* do failure management.
|
|
*/
|
|
if (asoc->shutdown_last_sent_to)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
|
|
SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
|
|
|
|
/* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
|
|
* the T2-shutdown timer.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
|
|
|
|
/* Restart the T2-shutdown timer. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* ADDIP Section 4.1 ASCONF CHunk Procedures
|
|
* If the T4 RTO timer expires the endpoint should do B1 to B5
|
|
*/
|
|
sctp_disposition_t sctp_sf_t4_timer_expire(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *chunk = asoc->addip_last_asconf;
|
|
struct sctp_transport *transport = chunk->transport;
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
|
|
|
|
/* ADDIP 4.1 B1) Increment the error counters and perform path failure
|
|
* detection on the appropriate destination address as defined in
|
|
* RFC2960 [5] section 8.1 and 8.2.
|
|
*/
|
|
if (transport)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
|
|
SCTP_TRANSPORT(transport));
|
|
|
|
/* Reconfig T4 timer and transport. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
|
|
|
|
/* ADDIP 4.1 B2) Increment the association error counters and perform
|
|
* endpoint failure detection on the association as defined in
|
|
* RFC2960 [5] section 8.1 and 8.2.
|
|
* association error counter is incremented in SCTP_CMD_STRIKE.
|
|
*/
|
|
if (asoc->overall_error_count >= asoc->max_retrans) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_DISPOSITION_ABORT;
|
|
}
|
|
|
|
/* ADDIP 4.1 B3) Back-off the destination address RTO value to which
|
|
* the ASCONF chunk was sent by doubling the RTO timer value.
|
|
* This is done in SCTP_CMD_STRIKE.
|
|
*/
|
|
|
|
/* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
|
|
* choose an alternate destination address (please refer to RFC2960
|
|
* [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
|
|
* chunk, it MUST be the same (including its serial number) as the last
|
|
* ASCONF sent.
|
|
*/
|
|
sctp_chunk_hold(asoc->addip_last_asconf);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(asoc->addip_last_asconf));
|
|
|
|
/* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
|
|
* destination is selected, then the RTO used will be that of the new
|
|
* destination address.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
|
|
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
|
|
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/* sctpimpguide-05 Section 2.12.2
|
|
* The sender of the SHUTDOWN MAY also start an overall guard timer
|
|
* 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
|
|
* At the expiration of this timer the sender SHOULD abort the association
|
|
* by sending an ABORT chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
struct sctp_chunk *reply = NULL;
|
|
|
|
SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
|
|
SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
|
|
|
|
reply = sctp_make_abort(asoc, NULL, 0);
|
|
if (!reply)
|
|
goto nomem;
|
|
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ETIMEDOUT));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_ERROR));
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
|
|
return SCTP_DISPOSITION_DELETE_TCB;
|
|
nomem:
|
|
return SCTP_DISPOSITION_NOMEM;
|
|
}
|
|
|
|
/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
|
|
* the association is automatically closed by starting the shutdown process.
|
|
* The work that needs to be done is same as when SHUTDOWN is initiated by
|
|
* the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
|
|
*/
|
|
sctp_disposition_t sctp_sf_autoclose_timer_expire(
|
|
const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
int disposition;
|
|
|
|
SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
|
|
|
|
/* From 9.2 Shutdown of an Association
|
|
* Upon receipt of the SHUTDOWN primitive from its upper
|
|
* layer, the endpoint enters SHUTDOWN-PENDING state and
|
|
* remains there until all outstanding data has been
|
|
* acknowledged by its peer. The endpoint accepts no new data
|
|
* from its upper layer, but retransmits data to the far end
|
|
* if necessary to fill gaps.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
|
|
SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
|
|
|
|
disposition = SCTP_DISPOSITION_CONSUME;
|
|
if (sctp_outq_is_empty(&asoc->outqueue)) {
|
|
disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
|
|
arg, commands);
|
|
}
|
|
return disposition;
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* These are sa state functions which could apply to all types of events.
|
|
****************************************************************************/
|
|
|
|
/*
|
|
* This table entry is not implemented.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
return SCTP_DISPOSITION_NOT_IMPL;
|
|
}
|
|
|
|
/*
|
|
* This table entry represents a bug.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
return SCTP_DISPOSITION_BUG;
|
|
}
|
|
|
|
/*
|
|
* This table entry represents the firing of a timer in the wrong state.
|
|
* Since timer deletion cannot be guaranteed a timer 'may' end up firing
|
|
* when the association is in the wrong state. This event should
|
|
* be ignored, so as to prevent any rearming of the timer.
|
|
*
|
|
* Inputs
|
|
* (endpoint, asoc, chunk)
|
|
*
|
|
* The return value is the disposition of the chunk.
|
|
*/
|
|
sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const sctp_subtype_t type,
|
|
void *arg,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
|
|
return SCTP_DISPOSITION_CONSUME;
|
|
}
|
|
|
|
/********************************************************************
|
|
* 2nd Level Abstractions
|
|
********************************************************************/
|
|
|
|
/* Pull the SACK chunk based on the SACK header. */
|
|
static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
|
|
{
|
|
struct sctp_sackhdr *sack;
|
|
unsigned int len;
|
|
__u16 num_blocks;
|
|
__u16 num_dup_tsns;
|
|
|
|
/* Protect ourselves from reading too far into
|
|
* the skb from a bogus sender.
|
|
*/
|
|
sack = (struct sctp_sackhdr *) chunk->skb->data;
|
|
|
|
num_blocks = ntohs(sack->num_gap_ack_blocks);
|
|
num_dup_tsns = ntohs(sack->num_dup_tsns);
|
|
len = sizeof(struct sctp_sackhdr);
|
|
len += (num_blocks + num_dup_tsns) * sizeof(__u32);
|
|
if (len > chunk->skb->len)
|
|
return NULL;
|
|
|
|
skb_pull(chunk->skb, len);
|
|
|
|
return sack;
|
|
}
|
|
|
|
/* Create an ABORT packet to be sent as a response, with the specified
|
|
* error causes.
|
|
*/
|
|
static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
const void *payload,
|
|
size_t paylen)
|
|
{
|
|
struct sctp_packet *packet;
|
|
struct sctp_chunk *abort;
|
|
|
|
packet = sctp_ootb_pkt_new(asoc, chunk);
|
|
|
|
if (packet) {
|
|
/* Make an ABORT.
|
|
* The T bit will be set if the asoc is NULL.
|
|
*/
|
|
abort = sctp_make_abort(asoc, chunk, paylen);
|
|
if (!abort) {
|
|
sctp_ootb_pkt_free(packet);
|
|
return NULL;
|
|
}
|
|
|
|
/* Reflect vtag if T-Bit is set */
|
|
if (sctp_test_T_bit(abort))
|
|
packet->vtag = ntohl(chunk->sctp_hdr->vtag);
|
|
|
|
/* Add specified error causes, i.e., payload, to the
|
|
* end of the chunk.
|
|
*/
|
|
sctp_addto_chunk(abort, paylen, payload);
|
|
|
|
/* Set the skb to the belonging sock for accounting. */
|
|
abort->skb->sk = ep->base.sk;
|
|
|
|
sctp_packet_append_chunk(packet, abort);
|
|
|
|
}
|
|
|
|
return packet;
|
|
}
|
|
|
|
/* Allocate a packet for responding in the OOTB conditions. */
|
|
static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
|
|
const struct sctp_chunk *chunk)
|
|
{
|
|
struct sctp_packet *packet;
|
|
struct sctp_transport *transport;
|
|
__u16 sport;
|
|
__u16 dport;
|
|
__u32 vtag;
|
|
|
|
/* Get the source and destination port from the inbound packet. */
|
|
sport = ntohs(chunk->sctp_hdr->dest);
|
|
dport = ntohs(chunk->sctp_hdr->source);
|
|
|
|
/* The V-tag is going to be the same as the inbound packet if no
|
|
* association exists, otherwise, use the peer's vtag.
|
|
*/
|
|
if (asoc) {
|
|
/* Special case the INIT-ACK as there is no peer's vtag
|
|
* yet.
|
|
*/
|
|
switch(chunk->chunk_hdr->type) {
|
|
case SCTP_CID_INIT_ACK:
|
|
{
|
|
sctp_initack_chunk_t *initack;
|
|
|
|
initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
|
|
vtag = ntohl(initack->init_hdr.init_tag);
|
|
break;
|
|
}
|
|
default:
|
|
vtag = asoc->peer.i.init_tag;
|
|
break;
|
|
}
|
|
} else {
|
|
/* Special case the INIT and stale COOKIE_ECHO as there is no
|
|
* vtag yet.
|
|
*/
|
|
switch(chunk->chunk_hdr->type) {
|
|
case SCTP_CID_INIT:
|
|
{
|
|
sctp_init_chunk_t *init;
|
|
|
|
init = (sctp_init_chunk_t *)chunk->chunk_hdr;
|
|
vtag = ntohl(init->init_hdr.init_tag);
|
|
break;
|
|
}
|
|
default:
|
|
vtag = ntohl(chunk->sctp_hdr->vtag);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Make a transport for the bucket, Eliza... */
|
|
transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
|
|
if (!transport)
|
|
goto nomem;
|
|
|
|
/* Cache a route for the transport with the chunk's destination as
|
|
* the source address.
|
|
*/
|
|
sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
|
|
sctp_sk(sctp_get_ctl_sock()));
|
|
|
|
packet = sctp_packet_init(&transport->packet, transport, sport, dport);
|
|
packet = sctp_packet_config(packet, vtag, 0);
|
|
|
|
return packet;
|
|
|
|
nomem:
|
|
return NULL;
|
|
}
|
|
|
|
/* Free the packet allocated earlier for responding in the OOTB condition. */
|
|
void sctp_ootb_pkt_free(struct sctp_packet *packet)
|
|
{
|
|
sctp_transport_free(packet->transport);
|
|
}
|
|
|
|
/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
|
|
static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
|
|
const struct sctp_association *asoc,
|
|
const struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands,
|
|
struct sctp_chunk *err_chunk)
|
|
{
|
|
struct sctp_packet *packet;
|
|
|
|
if (err_chunk) {
|
|
packet = sctp_ootb_pkt_new(asoc, chunk);
|
|
if (packet) {
|
|
struct sctp_signed_cookie *cookie;
|
|
|
|
/* Override the OOTB vtag from the cookie. */
|
|
cookie = chunk->subh.cookie_hdr;
|
|
packet->vtag = cookie->c.peer_vtag;
|
|
|
|
/* Set the skb to the belonging sock for accounting. */
|
|
err_chunk->skb->sk = ep->base.sk;
|
|
sctp_packet_append_chunk(packet, err_chunk);
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
|
|
SCTP_PACKET(packet));
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
} else
|
|
sctp_chunk_free (err_chunk);
|
|
}
|
|
}
|
|
|
|
|
|
/* Process a data chunk */
|
|
static int sctp_eat_data(const struct sctp_association *asoc,
|
|
struct sctp_chunk *chunk,
|
|
sctp_cmd_seq_t *commands)
|
|
{
|
|
sctp_datahdr_t *data_hdr;
|
|
struct sctp_chunk *err;
|
|
size_t datalen;
|
|
sctp_verb_t deliver;
|
|
int tmp;
|
|
__u32 tsn;
|
|
struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
|
|
struct sock *sk = asoc->base.sk;
|
|
u16 ssn;
|
|
u16 sid;
|
|
u8 ordered = 0;
|
|
|
|
data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
|
|
skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
|
|
|
|
tsn = ntohl(data_hdr->tsn);
|
|
SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
|
|
|
|
/* ASSERT: Now skb->data is really the user data. */
|
|
|
|
/* Process ECN based congestion.
|
|
*
|
|
* Since the chunk structure is reused for all chunks within
|
|
* a packet, we use ecn_ce_done to track if we've already
|
|
* done CE processing for this packet.
|
|
*
|
|
* We need to do ECN processing even if we plan to discard the
|
|
* chunk later.
|
|
*/
|
|
|
|
if (!chunk->ecn_ce_done) {
|
|
struct sctp_af *af;
|
|
chunk->ecn_ce_done = 1;
|
|
|
|
af = sctp_get_af_specific(
|
|
ipver2af(ip_hdr(chunk->skb)->version));
|
|
|
|
if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
|
|
/* Do real work as sideffect. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
|
|
SCTP_U32(tsn));
|
|
}
|
|
}
|
|
|
|
tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
|
|
if (tmp < 0) {
|
|
/* The TSN is too high--silently discard the chunk and
|
|
* count on it getting retransmitted later.
|
|
*/
|
|
return SCTP_IERROR_HIGH_TSN;
|
|
} else if (tmp > 0) {
|
|
/* This is a duplicate. Record it. */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
|
|
return SCTP_IERROR_DUP_TSN;
|
|
}
|
|
|
|
/* This is a new TSN. */
|
|
|
|
/* Discard if there is no room in the receive window.
|
|
* Actually, allow a little bit of overflow (up to a MTU).
|
|
*/
|
|
datalen = ntohs(chunk->chunk_hdr->length);
|
|
datalen -= sizeof(sctp_data_chunk_t);
|
|
|
|
deliver = SCTP_CMD_CHUNK_ULP;
|
|
|
|
/* Think about partial delivery. */
|
|
if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
|
|
|
|
/* Even if we don't accept this chunk there is
|
|
* memory pressure.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
|
|
}
|
|
|
|
/* Spill over rwnd a little bit. Note: While allowed, this spill over
|
|
* seems a bit troublesome in that frag_point varies based on
|
|
* PMTU. In cases, such as loopback, this might be a rather
|
|
* large spill over.
|
|
*/
|
|
if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
|
|
(datalen > asoc->rwnd + asoc->frag_point))) {
|
|
|
|
/* If this is the next TSN, consider reneging to make
|
|
* room. Note: Playing nice with a confused sender. A
|
|
* malicious sender can still eat up all our buffer
|
|
* space and in the future we may want to detect and
|
|
* do more drastic reneging.
|
|
*/
|
|
if (sctp_tsnmap_has_gap(map) &&
|
|
(sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
|
|
SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
|
|
deliver = SCTP_CMD_RENEGE;
|
|
} else {
|
|
SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
|
|
"rwnd: %d\n", tsn, datalen,
|
|
asoc->rwnd);
|
|
return SCTP_IERROR_IGNORE_TSN;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Also try to renege to limit our memory usage in the event that
|
|
* we are under memory pressure
|
|
* If we can't renege, don't worry about it, the sk_rmem_schedule
|
|
* in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
|
|
* memory usage too much
|
|
*/
|
|
if (*sk->sk_prot_creator->memory_pressure) {
|
|
if (sctp_tsnmap_has_gap(map) &&
|
|
(sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
|
|
SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
|
|
deliver = SCTP_CMD_RENEGE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Section 3.3.10.9 No User Data (9)
|
|
*
|
|
* Cause of error
|
|
* ---------------
|
|
* No User Data: This error cause is returned to the originator of a
|
|
* DATA chunk if a received DATA chunk has no user data.
|
|
*/
|
|
if (unlikely(0 == datalen)) {
|
|
err = sctp_make_abort_no_data(asoc, chunk, tsn);
|
|
if (err) {
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err));
|
|
}
|
|
/* We are going to ABORT, so we might as well stop
|
|
* processing the rest of the chunks in the packet.
|
|
*/
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
|
|
SCTP_ERROR(ECONNABORTED));
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
|
|
SCTP_PERR(SCTP_ERROR_NO_DATA));
|
|
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
|
|
SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
|
|
return SCTP_IERROR_NO_DATA;
|
|
}
|
|
|
|
chunk->data_accepted = 1;
|
|
|
|
/* Note: Some chunks may get overcounted (if we drop) or overcounted
|
|
* if we renege and the chunk arrives again.
|
|
*/
|
|
if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
|
|
SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
|
|
else {
|
|
SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
|
|
ordered = 1;
|
|
}
|
|
|
|
/* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
|
|
*
|
|
* If an endpoint receive a DATA chunk with an invalid stream
|
|
* identifier, it shall acknowledge the reception of the DATA chunk
|
|
* following the normal procedure, immediately send an ERROR chunk
|
|
* with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
|
|
* and discard the DATA chunk.
|
|
*/
|
|
sid = ntohs(data_hdr->stream);
|
|
if (sid >= asoc->c.sinit_max_instreams) {
|
|
/* Mark tsn as received even though we drop it */
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
|
|
|
|
err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
|
|
&data_hdr->stream,
|
|
sizeof(data_hdr->stream),
|
|
sizeof(u16));
|
|
if (err)
|
|
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
|
|
SCTP_CHUNK(err));
|
|
return SCTP_IERROR_BAD_STREAM;
|
|
}
|
|
|
|
/* Check to see if the SSN is possible for this TSN.
|
|
* The biggest gap we can record is 4K wide. Since SSNs wrap
|
|
* at an unsigned short, there is no way that an SSN can
|
|
* wrap and for a valid TSN. We can simply check if the current
|
|
* SSN is smaller then the next expected one. If it is, it wrapped
|
|
* and is invalid.
|
|
*/
|
|
ssn = ntohs(data_hdr->ssn);
|
|
if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
|
|
return SCTP_IERROR_PROTO_VIOLATION;
|
|
}
|
|
|
|
/* Send the data up to the user. Note: Schedule the
|
|
* SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
|
|
* chunk needs the updated rwnd.
|
|
*/
|
|
sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
|
|
|
|
return SCTP_IERROR_NO_ERROR;
|
|
}
|