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linux/net/lapb/lapb_in.c
Thomas Gleixner ee5d8f4d89 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 41 
Based on 1 normalized pattern(s):

  this module 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 18 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170858.008906948@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:27:12 +02:00

557 lines
15 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* LAPB release 002
*
* This code REQUIRES 2.1.15 or higher/ NET3.038
*
* History
* LAPB 001 Jonathan Naulor Started Coding
* LAPB 002 Jonathan Naylor New timer architecture.
* 2000-10-29 Henner Eisen lapb_data_indication() return status.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.h>
/*
* State machine for state 0, Disconnected State.
* The handling of the timer(s) is in file lapb_timer.c.
*/
static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
switch (frame->type) {
case LAPB_SABM:
lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
} else {
lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_3;
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_connect_indication(lapb, LAPB_OK);
}
break;
case LAPB_SABME:
lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_3;
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_connect_indication(lapb, LAPB_OK);
} else {
lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
}
break;
case LAPB_DISC:
lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf);
lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
break;
default:
break;
}
kfree_skb(skb);
}
/*
* State machine for state 1, Awaiting Connection State.
* The handling of the timer(s) is in file lapb_timer.c.
*/
static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
switch (frame->type) {
case LAPB_SABM:
lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
} else {
lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
}
break;
case LAPB_SABME:
lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
} else {
lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
}
break;
case LAPB_DISC:
lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf);
lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
break;
case LAPB_UA:
lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf);
if (frame->pf) {
lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_3;
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_connect_confirmation(lapb, LAPB_OK);
}
break;
case LAPB_DM:
lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf);
if (frame->pf) {
lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb_disconnect_indication(lapb, LAPB_REFUSED);
}
break;
}
kfree_skb(skb);
}
/*
* State machine for state 2, Awaiting Release State.
* The handling of the timer(s) is in file lapb_timer.c
*/
static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
switch (frame->type) {
case LAPB_SABM:
case LAPB_SABME:
lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
break;
case LAPB_DISC:
lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf);
lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
break;
case LAPB_UA:
lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf);
if (frame->pf) {
lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
lapb->state = LAPB_STATE_0;
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb_disconnect_confirmation(lapb, LAPB_OK);
}
break;
case LAPB_DM:
lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
if (frame->pf) {
lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
lapb->state = LAPB_STATE_0;
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
}
break;
case LAPB_I:
case LAPB_REJ:
case LAPB_RNR:
case LAPB_RR:
lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
if (frame->pf)
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
break;
}
kfree_skb(skb);
}
/*
* State machine for state 3, Connected State.
* The handling of the timer(s) is in file lapb_timer.c
*/
static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
int queued = 0;
int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
LAPB_SMODULUS;
switch (frame->type) {
case LAPB_SABM:
lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
} else {
lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_requeue_frames(lapb);
}
break;
case LAPB_SABME:
lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_requeue_frames(lapb);
} else {
lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
}
break;
case LAPB_DISC:
lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
lapb_clear_queues(lapb);
lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_0;
lapb_disconnect_indication(lapb, LAPB_OK);
break;
case LAPB_DM:
lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
break;
case LAPB_RNR:
lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n",
lapb->dev, frame->pf, frame->nr);
lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
lapb_check_need_response(lapb, frame->cr, frame->pf);
if (lapb_validate_nr(lapb, frame->nr)) {
lapb_check_iframes_acked(lapb, frame->nr);
} else {
lapb->frmr_data = *frame;
lapb->frmr_type = LAPB_FRMR_Z;
lapb_transmit_frmr(lapb);
lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_4;
lapb->n2count = 0;
}
break;
case LAPB_RR:
lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n",
lapb->dev, frame->pf, frame->nr);
lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
lapb_check_need_response(lapb, frame->cr, frame->pf);
if (lapb_validate_nr(lapb, frame->nr)) {
lapb_check_iframes_acked(lapb, frame->nr);
} else {
lapb->frmr_data = *frame;
lapb->frmr_type = LAPB_FRMR_Z;
lapb_transmit_frmr(lapb);
lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_4;
lapb->n2count = 0;
}
break;
case LAPB_REJ:
lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n",
lapb->dev, frame->pf, frame->nr);
lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
lapb_check_need_response(lapb, frame->cr, frame->pf);
if (lapb_validate_nr(lapb, frame->nr)) {
lapb_frames_acked(lapb, frame->nr);
lapb_stop_t1timer(lapb);
lapb->n2count = 0;
lapb_requeue_frames(lapb);
} else {
lapb->frmr_data = *frame;
lapb->frmr_type = LAPB_FRMR_Z;
lapb_transmit_frmr(lapb);
lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_4;
lapb->n2count = 0;
}
break;
case LAPB_I:
lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n",
lapb->dev, frame->pf, frame->ns, frame->nr);
if (!lapb_validate_nr(lapb, frame->nr)) {
lapb->frmr_data = *frame;
lapb->frmr_type = LAPB_FRMR_Z;
lapb_transmit_frmr(lapb);
lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_4;
lapb->n2count = 0;
break;
}
if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
lapb_frames_acked(lapb, frame->nr);
else
lapb_check_iframes_acked(lapb, frame->nr);
if (frame->ns == lapb->vr) {
int cn;
cn = lapb_data_indication(lapb, skb);
queued = 1;
/*
* If upper layer has dropped the frame, we
* basically ignore any further protocol
* processing. This will cause the peer
* to re-transmit the frame later like
* a frame lost on the wire.
*/
if (cn == NET_RX_DROP) {
pr_debug("rx congestion\n");
break;
}
lapb->vr = (lapb->vr + 1) % modulus;
lapb->condition &= ~LAPB_REJECT_CONDITION;
if (frame->pf)
lapb_enquiry_response(lapb);
else {
if (!(lapb->condition &
LAPB_ACK_PENDING_CONDITION)) {
lapb->condition |= LAPB_ACK_PENDING_CONDITION;
lapb_start_t2timer(lapb);
}
}
} else {
if (lapb->condition & LAPB_REJECT_CONDITION) {
if (frame->pf)
lapb_enquiry_response(lapb);
} else {
lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n",
lapb->dev, frame->pf, lapb->vr);
lapb->condition |= LAPB_REJECT_CONDITION;
lapb_send_control(lapb, LAPB_REJ, frame->pf,
LAPB_RESPONSE);
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
}
}
break;
case LAPB_FRMR:
lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n",
lapb->dev, frame->pf,
skb->data);
lapb_establish_data_link(lapb);
lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev);
lapb_requeue_frames(lapb);
lapb->state = LAPB_STATE_1;
break;
case LAPB_ILLEGAL:
lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf);
lapb->frmr_data = *frame;
lapb->frmr_type = LAPB_FRMR_W;
lapb_transmit_frmr(lapb);
lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
lapb_start_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_4;
lapb->n2count = 0;
break;
}
if (!queued)
kfree_skb(skb);
}
/*
* State machine for state 4, Frame Reject State.
* The handling of the timer(s) is in file lapb_timer.c.
*/
static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
switch (frame->type) {
case LAPB_SABM:
lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
} else {
lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_3;
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_connect_indication(lapb, LAPB_OK);
}
break;
case LAPB_SABME:
lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf);
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
lapb->dev, frame->pf);
lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
lapb_send_control(lapb, LAPB_UA, frame->pf,
LAPB_RESPONSE);
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb->state = LAPB_STATE_3;
lapb->condition = 0x00;
lapb->n2count = 0;
lapb->vs = 0;
lapb->vr = 0;
lapb->va = 0;
lapb_connect_indication(lapb, LAPB_OK);
} else {
lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
lapb->dev, frame->pf);
lapb_send_control(lapb, LAPB_DM, frame->pf,
LAPB_RESPONSE);
}
break;
}
kfree_skb(skb);
}
/*
* Process an incoming LAPB frame
*/
void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
{
struct lapb_frame frame;
if (lapb_decode(lapb, skb, &frame) < 0) {
kfree_skb(skb);
return;
}
switch (lapb->state) {
case LAPB_STATE_0:
lapb_state0_machine(lapb, skb, &frame); break;
case LAPB_STATE_1:
lapb_state1_machine(lapb, skb, &frame); break;
case LAPB_STATE_2:
lapb_state2_machine(lapb, skb, &frame); break;
case LAPB_STATE_3:
lapb_state3_machine(lapb, skb, &frame); break;
case LAPB_STATE_4:
lapb_state4_machine(lapb, skb, &frame); break;
}
lapb_kick(lapb);
}
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