linux/net/rxrpc/output.c
David Howells 75e4212639 rxrpc: Correctly initialise, limit and transmit call->rx_winsize
call->rx_winsize should be initialised to the sysctl setting and the sysctl
setting should be limited to the maximum we want to permit.  Further, we
need to place this in the ACK info instead of the sysctl setting.

Furthermore, discard the idea of accepting the subpackets of a jumbo packet
that lie beyond the receive window when the first packet of the jumbo is
within the window.  Just discard the excess subpackets instead.  This
allows the receive window to be opened up right to the buffer size less one
for the dead slot.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:38:45 +01:00

343 lines
8.2 KiB
C

/* RxRPC packet transmission
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program 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 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/net.h>
#include <linux/gfp.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <linux/udp.h>
#include <linux/ip.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
struct rxrpc_pkt_buffer {
struct rxrpc_wire_header whdr;
union {
struct {
struct rxrpc_ackpacket ack;
u8 acks[255];
u8 pad[3];
};
__be32 abort_code;
};
struct rxrpc_ackinfo ackinfo;
};
/*
* Fill out an ACK packet.
*/
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
struct rxrpc_pkt_buffer *pkt)
{
rxrpc_seq_t hard_ack, top, seq;
int ix;
u32 mtu, jmax;
u8 *ackp = pkt->acks;
/* Barrier against rxrpc_input_data(). */
hard_ack = READ_ONCE(call->rx_hard_ack);
top = smp_load_acquire(&call->rx_top);
pkt->ack.bufferSpace = htons(8);
pkt->ack.maxSkew = htons(call->ackr_skew);
pkt->ack.firstPacket = htonl(hard_ack + 1);
pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
pkt->ack.serial = htonl(call->ackr_serial);
pkt->ack.reason = call->ackr_reason;
pkt->ack.nAcks = top - hard_ack;
if (after(top, hard_ack)) {
seq = hard_ack + 1;
do {
ix = seq & RXRPC_RXTX_BUFF_MASK;
if (call->rxtx_buffer[ix])
*ackp++ = RXRPC_ACK_TYPE_ACK;
else
*ackp++ = RXRPC_ACK_TYPE_NACK;
seq++;
} while (before_eq(seq, top));
}
mtu = call->conn->params.peer->if_mtu;
mtu -= call->conn->params.peer->hdrsize;
jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
pkt->ackinfo.maxMTU = htonl(mtu);
pkt->ackinfo.rwind = htonl(call->rx_winsize);
pkt->ackinfo.jumbo_max = htonl(jmax);
*ackp++ = 0;
*ackp++ = 0;
*ackp++ = 0;
return top - hard_ack + 3;
}
/*
* Send an ACK or ABORT call packet.
*/
int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
{
struct rxrpc_connection *conn = NULL;
struct rxrpc_pkt_buffer *pkt;
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
size_t len, n;
int ioc, ret;
u32 abort_code;
_enter("%u,%s", call->debug_id, rxrpc_pkts[type]);
spin_lock_bh(&call->lock);
if (call->conn)
conn = rxrpc_get_connection_maybe(call->conn);
spin_unlock_bh(&call->lock);
if (!conn)
return -ECONNRESET;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt) {
rxrpc_put_connection(conn);
return -ENOMEM;
}
serial = atomic_inc_return(&conn->serial);
msg.msg_name = &call->peer->srx.transport;
msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
pkt->whdr.epoch = htonl(conn->proto.epoch);
pkt->whdr.cid = htonl(call->cid);
pkt->whdr.callNumber = htonl(call->call_id);
pkt->whdr.seq = 0;
pkt->whdr.serial = htonl(serial);
pkt->whdr.type = type;
pkt->whdr.flags = conn->out_clientflag;
pkt->whdr.userStatus = 0;
pkt->whdr.securityIndex = call->security_ix;
pkt->whdr._rsvd = 0;
pkt->whdr.serviceId = htons(call->service_id);
iov[0].iov_base = pkt;
iov[0].iov_len = sizeof(pkt->whdr);
len = sizeof(pkt->whdr);
switch (type) {
case RXRPC_PACKET_TYPE_ACK:
spin_lock_bh(&call->lock);
n = rxrpc_fill_out_ack(call, pkt);
call->ackr_reason = 0;
spin_unlock_bh(&call->lock);
_proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
serial,
ntohs(pkt->ack.maxSkew),
ntohl(pkt->ack.firstPacket),
ntohl(pkt->ack.previousPacket),
ntohl(pkt->ack.serial),
rxrpc_acks(pkt->ack.reason),
pkt->ack.nAcks);
iov[0].iov_len += sizeof(pkt->ack) + n;
iov[1].iov_base = &pkt->ackinfo;
iov[1].iov_len = sizeof(pkt->ackinfo);
len += sizeof(pkt->ack) + n + sizeof(pkt->ackinfo);
ioc = 2;
break;
case RXRPC_PACKET_TYPE_ABORT:
abort_code = call->abort_code;
pkt->abort_code = htonl(abort_code);
_proto("Tx ABORT %%%u { %d }", serial, abort_code);
iov[0].iov_len += sizeof(pkt->abort_code);
len += sizeof(pkt->abort_code);
ioc = 1;
break;
default:
BUG();
ret = -ENOANO;
goto out;
}
ret = kernel_sendmsg(conn->params.local->socket,
&msg, iov, ioc, len);
if (ret < 0 && call->state < RXRPC_CALL_COMPLETE) {
switch (pkt->whdr.type) {
case RXRPC_PACKET_TYPE_ACK:
rxrpc_propose_ACK(call, pkt->ack.reason,
ntohs(pkt->ack.maxSkew),
ntohl(pkt->ack.serial),
true, true);
break;
case RXRPC_PACKET_TYPE_ABORT:
break;
}
}
out:
rxrpc_put_connection(conn);
kfree(pkt);
return ret;
}
/*
* send a packet through the transport endpoint
*/
int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
{
struct kvec iov[1];
struct msghdr msg;
int ret, opt;
_enter(",{%d}", skb->len);
iov[0].iov_base = skb->head;
iov[0].iov_len = skb->len;
msg.msg_name = &conn->params.peer->srx.transport;
msg.msg_namelen = conn->params.peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
/* send the packet with the don't fragment bit set if we currently
* think it's small enough */
if (skb->len - sizeof(struct rxrpc_wire_header) < conn->params.peer->maxdata) {
down_read(&conn->params.local->defrag_sem);
/* send the packet by UDP
* - returns -EMSGSIZE if UDP would have to fragment the packet
* to go out of the interface
* - in which case, we'll have processed the ICMP error
* message and update the peer record
*/
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
iov[0].iov_len);
up_read(&conn->params.local->defrag_sem);
if (ret == -EMSGSIZE)
goto send_fragmentable;
_leave(" = %d [%u]", ret, conn->params.peer->maxdata);
return ret;
}
send_fragmentable:
/* attempt to send this message with fragmentation enabled */
_debug("send fragment");
down_write(&conn->params.local->defrag_sem);
switch (conn->params.local->srx.transport.family) {
case AF_INET:
opt = IP_PMTUDISC_DONT;
ret = kernel_setsockopt(conn->params.local->socket,
SOL_IP, IP_MTU_DISCOVER,
(char *)&opt, sizeof(opt));
if (ret == 0) {
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
iov[0].iov_len);
opt = IP_PMTUDISC_DO;
kernel_setsockopt(conn->params.local->socket, SOL_IP,
IP_MTU_DISCOVER,
(char *)&opt, sizeof(opt));
}
break;
}
up_write(&conn->params.local->defrag_sem);
_leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
return ret;
}
/*
* reject packets through the local endpoint
*/
void rxrpc_reject_packets(struct rxrpc_local *local)
{
union {
struct sockaddr sa;
struct sockaddr_in sin;
} sa;
struct rxrpc_skb_priv *sp;
struct rxrpc_wire_header whdr;
struct sk_buff *skb;
struct msghdr msg;
struct kvec iov[2];
size_t size;
__be32 code;
_enter("%d", local->debug_id);
iov[0].iov_base = &whdr;
iov[0].iov_len = sizeof(whdr);
iov[1].iov_base = &code;
iov[1].iov_len = sizeof(code);
size = sizeof(whdr) + sizeof(code);
msg.msg_name = &sa;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
memset(&sa, 0, sizeof(sa));
sa.sa.sa_family = local->srx.transport.family;
switch (sa.sa.sa_family) {
case AF_INET:
msg.msg_namelen = sizeof(sa.sin);
break;
default:
msg.msg_namelen = 0;
break;
}
memset(&whdr, 0, sizeof(whdr));
whdr.type = RXRPC_PACKET_TYPE_ABORT;
while ((skb = skb_dequeue(&local->reject_queue))) {
rxrpc_see_skb(skb);
sp = rxrpc_skb(skb);
switch (sa.sa.sa_family) {
case AF_INET:
sa.sin.sin_port = udp_hdr(skb)->source;
sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
code = htonl(skb->priority);
whdr.epoch = htonl(sp->hdr.epoch);
whdr.cid = htonl(sp->hdr.cid);
whdr.callNumber = htonl(sp->hdr.callNumber);
whdr.serviceId = htons(sp->hdr.serviceId);
whdr.flags = sp->hdr.flags;
whdr.flags ^= RXRPC_CLIENT_INITIATED;
whdr.flags &= RXRPC_CLIENT_INITIATED;
kernel_sendmsg(local->socket, &msg, iov, 2, size);
break;
default:
break;
}
rxrpc_free_skb(skb);
}
_leave("");
}