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1629 |
jcastillo |
/*
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* AX.25 release 035
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*
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* This code REQUIRES 1.2.1 or higher/ NET3.029
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*
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* This module:
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* This module is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Most of this code is based on the SDL diagrams published in the 7th
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* ARRL Computer Networking Conference papers. The diagrams have mistakes
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* in them, but are mostly correct. Before you modify the code could you
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* read the SDL diagrams as the code is not obvious and probably very
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* easy to break;
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*
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* History
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* AX.25 028a Jonathan(G4KLX) New state machine based on SDL diagrams.
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* AX.25 028b Jonathan(G4KLX) Extracted AX25 control block from
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* the sock structure.
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* AX.25 029 Alan(GW4PTS) Switched to KA9Q constant names.
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* Jonathan(G4KLX) Added IP mode registration.
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* AX.25 030 Jonathan(G4KLX) Added AX.25 fragment reception.
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* Upgraded state machine for SABME.
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* Added arbitrary protocol id support.
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* AX.25 031 Joerg(DL1BKE) Added DAMA support
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* HaJo(DD8NE) Added Idle Disc Timer T5
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* Joerg(DL1BKE) Renamed it to "IDLE" with a slightly
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* different behaviour. Fixed defrag
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* routine (I hope)
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* AX.25 032 Darryl(G7LED) AX.25 segmentation fixed.
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* AX.25 033 Jonathan(G4KLX) Remove auto-router.
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* Modularisation changes.
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* Joerg(DL1BKE) Fixed 2.0.x specific IP over AX.25 problem.
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*/
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#include <linux/config.h>
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#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <net/ax25.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <net/ip.h> /* For ip_rcv */
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#include <asm/segment.h>
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#include <asm/system.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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static int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
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/*
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* Given a fragment, queue it on the fragment queue and if the fragment
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* is complete, send it back to ax25_rx_iframe.
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*/
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static int ax25_rx_fragment(ax25_cb *ax25, struct sk_buff *skb)
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{
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struct sk_buff *skbn, *skbo;
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| 71 |
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| 72 |
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if (ax25->fragno != 0) {
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if (!(*skb->data & AX25_SEG_FIRST)) {
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if ((ax25->fragno - 1) == (*skb->data & AX25_SEG_REM)) {
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/* Enqueue fragment */
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ax25->fragno = *skb->data & AX25_SEG_REM;
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skb_pull(skb, 1); /* skip fragno */
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ax25->fraglen += skb->len;
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skb_queue_tail(&ax25->frag_queue, skb);
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| 81 |
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/* Last fragment received ? */
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| 82 |
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if (ax25->fragno == 0) {
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if ((skbn = alloc_skb(AX25_MAX_HEADER_LEN + ax25->fraglen, GFP_ATOMIC)) == NULL) {
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while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL)
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kfree_skb(skbo, FREE_READ);
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| 86 |
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return 1;
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| 87 |
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}
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| 88 |
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| 89 |
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skb_reserve(skbn, AX25_MAX_HEADER_LEN);
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| 90 |
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| 91 |
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skbn->free = 1;
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skbn->dev = ax25->device;
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skbn->h.raw = skbn->data;
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| 95 |
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/* Copy data from the fragments */
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while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {
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memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
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kfree_skb(skbo, FREE_READ);
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}
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| 101 |
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ax25->fraglen = 0;
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| 103 |
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if (ax25_rx_iframe(ax25, skbn) == 0)
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kfree_skb(skbn, FREE_READ);
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}
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return 1;
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}
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}
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} else {
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/* First fragment received */
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if (*skb->data & AX25_SEG_FIRST) {
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while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL)
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kfree_skb(skbo, FREE_READ);
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ax25->fragno = *skb->data & AX25_SEG_REM;
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skb_pull(skb, 1); /* skip fragno */
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ax25->fraglen = skb->len;
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skb_queue_tail(&ax25->frag_queue, skb);
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return 1;
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}
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| 121 |
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}
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| 122 |
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| 123 |
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return 0;
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}
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| 125 |
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| 126 |
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/*
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| 127 |
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* This is where all valid I frames are sent to, to be dispatched to
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| 128 |
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* whichever protocol requires them.
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*/
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static int ax25_rx_iframe(ax25_cb *ax25, struct sk_buff *skb)
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{
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| 132 |
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int (*func)(struct sk_buff *, ax25_cb *);
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| 133 |
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struct sk_buff *skbn;
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volatile int queued = 0;
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| 135 |
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unsigned char pid;
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| 136 |
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| 137 |
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if (skb == NULL) return 0;
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| 138 |
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| 139 |
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ax25->idletimer = ax25->idle;
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| 140 |
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| 141 |
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pid = *skb->data;
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| 142 |
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| 143 |
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#ifdef CONFIG_INET
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if (pid == AX25_P_IP) {
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if ((skbn = skb_copy(skb, GFP_ATOMIC)) != NULL) {
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kfree_skb(skb, FREE_READ);
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skb = skbn;
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}
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skb_pull(skb, 1); /* Remove PID */
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skb->h.raw = skb->data;
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ip_rcv(skb, ax25->device, NULL); /* Wrong ptype */
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return 1;
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}
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#endif
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if (pid == AX25_P_SEGMENT) {
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skb_pull(skb, 1); /* Remove PID */
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return ax25_rx_fragment(ax25, skb);
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}
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| 159 |
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| 160 |
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if ((func = ax25_protocol_function(pid)) != NULL) {
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skb_pull(skb, 1); /* Remove PID */
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return (*func)(skb, ax25);
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}
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if (ax25->sk != NULL && ax25_dev_get_value(ax25->device, AX25_VALUES_CONMODE) == 2) {
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if ((!ax25->pidincl && ax25->sk->protocol == pid) || ax25->pidincl) {
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if (sock_queue_rcv_skb(ax25->sk, skb) == 0)
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queued = 1;
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else
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| 170 |
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ax25->condition |= AX25_COND_OWN_RX_BUSY;
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}
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| 172 |
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}
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| 173 |
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| 174 |
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return queued;
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| 175 |
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}
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/*
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* State machine for state 1, Awaiting Connection State.
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| 179 |
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* The handling of the timer(s) is in file ax25_timer.c.
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| 180 |
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* Handling of state 0 and connection release is in ax25.c.
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*/
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static int ax25_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type, int dama)
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{
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| 184 |
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switch (frametype) {
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| 185 |
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case AX25_SABM:
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| 186 |
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ax25->modulus = AX25_MODULUS;
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ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
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| 188 |
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ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
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| 189 |
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break;
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| 190 |
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| 191 |
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case AX25_SABME:
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| 192 |
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ax25->modulus = AX25_EMODULUS;
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| 193 |
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ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_EWINDOW);
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| 194 |
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ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
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| 195 |
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break;
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| 196 |
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| 197 |
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case AX25_DISC:
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| 198 |
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ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
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| 199 |
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break;
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| 200 |
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| 201 |
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case AX25_UA:
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| 202 |
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if (pf || dama) {
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| 203 |
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if (dama) ax25_dama_on(ax25); /* bke */
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| 204 |
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ax25_calculate_rtt(ax25);
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| 205 |
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ax25->t1timer = 0;
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| 206 |
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ax25->t3timer = ax25->t3;
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| 207 |
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ax25->idletimer = ax25->idle;
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| 208 |
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ax25->vs = 0;
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| 209 |
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ax25->va = 0;
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| 210 |
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ax25->vr = 0;
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| 211 |
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ax25->state = AX25_STATE_3;
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| 212 |
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ax25->n2count = 0;
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| 213 |
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ax25->dama_slave = dama; /* bke */
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| 214 |
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if (ax25->sk != NULL) {
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| 215 |
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ax25->sk->state = TCP_ESTABLISHED;
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| 216 |
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/* For WAIT_SABM connections we will produce an accept ready socket here */
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| 217 |
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if (!ax25->sk->dead)
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| 218 |
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ax25->sk->state_change(ax25->sk);
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| 219 |
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}
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| 220 |
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}
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| 221 |
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break;
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| 222 |
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| 223 |
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case AX25_DM:
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| 224 |
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if (pf) {
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| 225 |
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if (ax25->modulus == AX25_MODULUS) {
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| 226 |
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ax25_disconnect(ax25, ECONNREFUSED);
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| 227 |
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} else {
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| 228 |
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ax25->modulus = AX25_MODULUS;
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| 229 |
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ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
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| 230 |
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}
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| 231 |
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}
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| 232 |
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break;
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| 233 |
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| 234 |
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default:
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| 235 |
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if (dama && pf)
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| 236 |
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ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
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| 237 |
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break;
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| 238 |
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}
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| 239 |
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| 240 |
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return 0;
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| 241 |
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}
|
| 242 |
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|
| 243 |
|
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/*
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| 244 |
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* State machine for state 2, Awaiting Release State.
|
| 245 |
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* The handling of the timer(s) is in file ax25_timer.c
|
| 246 |
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* Handling of state 0 and connection release is in ax25.c.
|
| 247 |
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*/
|
| 248 |
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static int ax25_state2_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
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| 249 |
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{
|
| 250 |
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switch (frametype) {
|
| 251 |
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case AX25_SABM:
|
| 252 |
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case AX25_SABME:
|
| 253 |
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ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
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| 254 |
|
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if (ax25->dama_slave)
|
| 255 |
|
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ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
|
| 256 |
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break;
|
| 257 |
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| 258 |
|
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case AX25_DISC:
|
| 259 |
|
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ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
| 260 |
|
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if (ax25->dama_slave) ax25_disconnect(ax25, 0);
|
| 261 |
|
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break;
|
| 262 |
|
|
|
| 263 |
|
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case AX25_DM:
|
| 264 |
|
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case AX25_UA:
|
| 265 |
|
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if (pf) ax25_disconnect(ax25, 0);
|
| 266 |
|
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break;
|
| 267 |
|
|
|
| 268 |
|
|
case AX25_I:
|
| 269 |
|
|
case AX25_REJ:
|
| 270 |
|
|
case AX25_RNR:
|
| 271 |
|
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case AX25_RR:
|
| 272 |
|
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if (pf) {
|
| 273 |
|
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if (ax25->dama_slave)
|
| 274 |
|
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ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
|
| 275 |
|
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else
|
| 276 |
|
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ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
|
| 277 |
|
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}
|
| 278 |
|
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break;
|
| 279 |
|
|
|
| 280 |
|
|
default:
|
| 281 |
|
|
break;
|
| 282 |
|
|
}
|
| 283 |
|
|
|
| 284 |
|
|
return 0;
|
| 285 |
|
|
}
|
| 286 |
|
|
|
| 287 |
|
|
/*
|
| 288 |
|
|
* State machine for state 3, Connected State.
|
| 289 |
|
|
* The handling of the timer(s) is in file ax25_timer.c
|
| 290 |
|
|
* Handling of state 0 and connection release is in ax25.c.
|
| 291 |
|
|
*/
|
| 292 |
|
|
static int ax25_state3_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int ns, int nr, int pf, int type, int dama)
|
| 293 |
|
|
{
|
| 294 |
|
|
int queued = 0;
|
| 295 |
|
|
|
| 296 |
|
|
switch (frametype) {
|
| 297 |
|
|
case AX25_SABM:
|
| 298 |
|
|
case AX25_SABME:
|
| 299 |
|
|
if (dama) ax25_dama_on(ax25);
|
| 300 |
|
|
if (frametype == AX25_SABM) {
|
| 301 |
|
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ax25->modulus = AX25_MODULUS;
|
| 302 |
|
|
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
|
| 303 |
|
|
} else {
|
| 304 |
|
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ax25->modulus = AX25_EMODULUS;
|
| 305 |
|
|
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_EWINDOW);
|
| 306 |
|
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}
|
| 307 |
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
| 308 |
|
|
ax25->condition = 0x00;
|
| 309 |
|
|
ax25->t1timer = 0;
|
| 310 |
|
|
ax25->t3timer = ax25->t3;
|
| 311 |
|
|
ax25->idletimer = ax25->idle;
|
| 312 |
|
|
ax25->vs = 0;
|
| 313 |
|
|
ax25->va = 0;
|
| 314 |
|
|
ax25->vr = 0;
|
| 315 |
|
|
ax25->dama_slave = dama;
|
| 316 |
|
|
ax25_requeue_frames(ax25);
|
| 317 |
|
|
break;
|
| 318 |
|
|
|
| 319 |
|
|
case AX25_DISC:
|
| 320 |
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
| 321 |
|
|
ax25_disconnect(ax25, 0);
|
| 322 |
|
|
break;
|
| 323 |
|
|
|
| 324 |
|
|
case AX25_DM:
|
| 325 |
|
|
ax25_disconnect(ax25, ECONNRESET);
|
| 326 |
|
|
break;
|
| 327 |
|
|
|
| 328 |
|
|
case AX25_RR:
|
| 329 |
|
|
case AX25_RNR:
|
| 330 |
|
|
if (frametype == AX25_RR)
|
| 331 |
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
| 332 |
|
|
else
|
| 333 |
|
|
ax25->condition |= AX25_COND_PEER_RX_BUSY;
|
| 334 |
|
|
if (!ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 335 |
|
|
ax25_enquiry_response(ax25);
|
| 336 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 337 |
|
|
ax25_check_iframes_acked(ax25, nr);
|
| 338 |
|
|
if (ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 339 |
|
|
dama_enquiry_response(ax25);
|
| 340 |
|
|
} else {
|
| 341 |
|
|
ax25_nr_error_recovery(ax25);
|
| 342 |
|
|
ax25->state = AX25_STATE_1;
|
| 343 |
|
|
}
|
| 344 |
|
|
break;
|
| 345 |
|
|
|
| 346 |
|
|
case AX25_REJ:
|
| 347 |
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
| 348 |
|
|
if (!ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 349 |
|
|
ax25_enquiry_response(ax25);
|
| 350 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 351 |
|
|
ax25_frames_acked(ax25, nr);
|
| 352 |
|
|
ax25_calculate_rtt(ax25);
|
| 353 |
|
|
ax25->t1timer = 0;
|
| 354 |
|
|
ax25->t3timer = ax25->t3;
|
| 355 |
|
|
ax25_requeue_frames(ax25);
|
| 356 |
|
|
if (ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 357 |
|
|
dama_enquiry_response(ax25);
|
| 358 |
|
|
} else {
|
| 359 |
|
|
ax25_nr_error_recovery(ax25);
|
| 360 |
|
|
ax25->state = AX25_STATE_1;
|
| 361 |
|
|
}
|
| 362 |
|
|
break;
|
| 363 |
|
|
|
| 364 |
|
|
case AX25_I:
|
| 365 |
|
|
if (!ax25_validate_nr(ax25, nr)) {
|
| 366 |
|
|
ax25_nr_error_recovery(ax25);
|
| 367 |
|
|
ax25->state = AX25_STATE_1;
|
| 368 |
|
|
break;
|
| 369 |
|
|
}
|
| 370 |
|
|
if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
|
| 371 |
|
|
ax25_frames_acked(ax25, nr);
|
| 372 |
|
|
} else {
|
| 373 |
|
|
ax25_check_iframes_acked(ax25, nr);
|
| 374 |
|
|
}
|
| 375 |
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
|
| 376 |
|
|
if (pf) {
|
| 377 |
|
|
if (ax25->dama_slave)
|
| 378 |
|
|
dama_enquiry_response(ax25);
|
| 379 |
|
|
else
|
| 380 |
|
|
ax25_enquiry_response(ax25);
|
| 381 |
|
|
}
|
| 382 |
|
|
break;
|
| 383 |
|
|
}
|
| 384 |
|
|
if (ns == ax25->vr) {
|
| 385 |
|
|
ax25->vr = (ax25->vr + 1) % ax25->modulus;
|
| 386 |
|
|
queued = ax25_rx_iframe(ax25, skb);
|
| 387 |
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY)
|
| 388 |
|
|
ax25->vr = ns; /* ax25->vr - 1 */
|
| 389 |
|
|
ax25->condition &= ~AX25_COND_REJECT;
|
| 390 |
|
|
if (pf) {
|
| 391 |
|
|
if (ax25->dama_slave)
|
| 392 |
|
|
dama_enquiry_response(ax25);
|
| 393 |
|
|
else
|
| 394 |
|
|
ax25_enquiry_response(ax25);
|
| 395 |
|
|
} else {
|
| 396 |
|
|
if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
|
| 397 |
|
|
ax25->t2timer = ax25->t2;
|
| 398 |
|
|
ax25->condition |= AX25_COND_ACK_PENDING;
|
| 399 |
|
|
}
|
| 400 |
|
|
}
|
| 401 |
|
|
} else {
|
| 402 |
|
|
if (ax25->condition & AX25_COND_REJECT) {
|
| 403 |
|
|
if (pf) {
|
| 404 |
|
|
if (ax25->dama_slave)
|
| 405 |
|
|
dama_enquiry_response(ax25);
|
| 406 |
|
|
else
|
| 407 |
|
|
ax25_enquiry_response(ax25);
|
| 408 |
|
|
}
|
| 409 |
|
|
} else {
|
| 410 |
|
|
ax25->condition |= AX25_COND_REJECT;
|
| 411 |
|
|
if (ax25->dama_slave)
|
| 412 |
|
|
dama_enquiry_response(ax25);
|
| 413 |
|
|
else
|
| 414 |
|
|
ax25_send_control(ax25, AX25_REJ, pf, AX25_RESPONSE);
|
| 415 |
|
|
ax25->condition &= ~AX25_COND_ACK_PENDING;
|
| 416 |
|
|
}
|
| 417 |
|
|
}
|
| 418 |
|
|
break;
|
| 419 |
|
|
|
| 420 |
|
|
case AX25_FRMR:
|
| 421 |
|
|
case AX25_ILLEGAL:
|
| 422 |
|
|
ax25_establish_data_link(ax25);
|
| 423 |
|
|
ax25->state = AX25_STATE_1;
|
| 424 |
|
|
break;
|
| 425 |
|
|
|
| 426 |
|
|
default:
|
| 427 |
|
|
break;
|
| 428 |
|
|
}
|
| 429 |
|
|
|
| 430 |
|
|
return queued;
|
| 431 |
|
|
}
|
| 432 |
|
|
|
| 433 |
|
|
/*
|
| 434 |
|
|
* State machine for state 4, Timer Recovery State.
|
| 435 |
|
|
* The handling of the timer(s) is in file ax25_timer.c
|
| 436 |
|
|
* Handling of state 0 and connection release is in ax25.c.
|
| 437 |
|
|
*/
|
| 438 |
|
|
static int ax25_state4_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int ns, int nr, int pf, int type, int dama)
|
| 439 |
|
|
{
|
| 440 |
|
|
int queued = 0;
|
| 441 |
|
|
|
| 442 |
|
|
switch (frametype) {
|
| 443 |
|
|
case AX25_SABM:
|
| 444 |
|
|
case AX25_SABME:
|
| 445 |
|
|
if (dama) ax25_dama_on(ax25);
|
| 446 |
|
|
if (frametype == AX25_SABM) {
|
| 447 |
|
|
ax25->modulus = AX25_MODULUS;
|
| 448 |
|
|
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
|
| 449 |
|
|
} else {
|
| 450 |
|
|
ax25->modulus = AX25_EMODULUS;
|
| 451 |
|
|
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_EWINDOW);
|
| 452 |
|
|
}
|
| 453 |
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
| 454 |
|
|
ax25->condition = 0x00;
|
| 455 |
|
|
ax25->t1timer = 0;
|
| 456 |
|
|
ax25->t3timer = ax25->t3;
|
| 457 |
|
|
ax25->idletimer = ax25->idle;
|
| 458 |
|
|
ax25->vs = 0;
|
| 459 |
|
|
ax25->va = 0;
|
| 460 |
|
|
ax25->vr = 0;
|
| 461 |
|
|
ax25->state = AX25_STATE_3;
|
| 462 |
|
|
ax25->n2count = 0;
|
| 463 |
|
|
ax25->dama_slave = dama;
|
| 464 |
|
|
ax25_requeue_frames(ax25);
|
| 465 |
|
|
break;
|
| 466 |
|
|
|
| 467 |
|
|
case AX25_DISC:
|
| 468 |
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
| 469 |
|
|
ax25_disconnect(ax25, 0);
|
| 470 |
|
|
break;
|
| 471 |
|
|
|
| 472 |
|
|
case AX25_DM:
|
| 473 |
|
|
ax25_disconnect(ax25, ECONNRESET);
|
| 474 |
|
|
break;
|
| 475 |
|
|
|
| 476 |
|
|
case AX25_RR:
|
| 477 |
|
|
case AX25_RNR:
|
| 478 |
|
|
if (frametype == AX25_RR)
|
| 479 |
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
| 480 |
|
|
else
|
| 481 |
|
|
ax25->condition |= AX25_COND_PEER_RX_BUSY;
|
| 482 |
|
|
if (type == AX25_RESPONSE && pf) {
|
| 483 |
|
|
ax25->t1timer = 0;
|
| 484 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 485 |
|
|
ax25_frames_acked(ax25, nr);
|
| 486 |
|
|
if (ax25->vs == ax25->va) {
|
| 487 |
|
|
ax25->t3timer = ax25->t3;
|
| 488 |
|
|
ax25->n2count = 0;
|
| 489 |
|
|
ax25->state = AX25_STATE_3;
|
| 490 |
|
|
} else {
|
| 491 |
|
|
ax25_requeue_frames(ax25);
|
| 492 |
|
|
}
|
| 493 |
|
|
} else {
|
| 494 |
|
|
ax25_nr_error_recovery(ax25);
|
| 495 |
|
|
ax25->state = AX25_STATE_1;
|
| 496 |
|
|
}
|
| 497 |
|
|
break;
|
| 498 |
|
|
}
|
| 499 |
|
|
if (!ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 500 |
|
|
ax25_enquiry_response(ax25);
|
| 501 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 502 |
|
|
ax25_frames_acked(ax25, nr);
|
| 503 |
|
|
if (ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 504 |
|
|
dama_enquiry_response(ax25);
|
| 505 |
|
|
} else {
|
| 506 |
|
|
ax25_nr_error_recovery(ax25);
|
| 507 |
|
|
ax25->state = AX25_STATE_1;
|
| 508 |
|
|
}
|
| 509 |
|
|
break;
|
| 510 |
|
|
|
| 511 |
|
|
case AX25_REJ:
|
| 512 |
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
| 513 |
|
|
if (pf && (type == AX25_RESPONSE || (ax25->dama_slave && type == AX25_COMMAND))) {
|
| 514 |
|
|
ax25->t1timer = 0;
|
| 515 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 516 |
|
|
ax25_frames_acked(ax25, nr);
|
| 517 |
|
|
if (ax25->vs == ax25->va) {
|
| 518 |
|
|
ax25->t3timer = ax25->t3;
|
| 519 |
|
|
ax25->n2count = 0;
|
| 520 |
|
|
ax25->state = AX25_STATE_3;
|
| 521 |
|
|
} else {
|
| 522 |
|
|
ax25_requeue_frames(ax25);
|
| 523 |
|
|
}
|
| 524 |
|
|
if (ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 525 |
|
|
dama_enquiry_response(ax25);
|
| 526 |
|
|
} else {
|
| 527 |
|
|
ax25_nr_error_recovery(ax25);
|
| 528 |
|
|
ax25->state = AX25_STATE_1;
|
| 529 |
|
|
}
|
| 530 |
|
|
break;
|
| 531 |
|
|
}
|
| 532 |
|
|
if (!ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 533 |
|
|
ax25_enquiry_response(ax25);
|
| 534 |
|
|
if (ax25_validate_nr(ax25, nr)) {
|
| 535 |
|
|
ax25_frames_acked(ax25, nr);
|
| 536 |
|
|
ax25_requeue_frames(ax25);
|
| 537 |
|
|
if (ax25->dama_slave && type == AX25_COMMAND && pf)
|
| 538 |
|
|
dama_enquiry_response(ax25);
|
| 539 |
|
|
} else {
|
| 540 |
|
|
ax25_nr_error_recovery(ax25);
|
| 541 |
|
|
ax25->state = AX25_STATE_1;
|
| 542 |
|
|
}
|
| 543 |
|
|
break;
|
| 544 |
|
|
|
| 545 |
|
|
case AX25_I:
|
| 546 |
|
|
if (!ax25_validate_nr(ax25, nr)) {
|
| 547 |
|
|
ax25_nr_error_recovery(ax25);
|
| 548 |
|
|
ax25->state = AX25_STATE_1;
|
| 549 |
|
|
break;
|
| 550 |
|
|
}
|
| 551 |
|
|
ax25_frames_acked(ax25, nr);
|
| 552 |
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
|
| 553 |
|
|
if (pf) {
|
| 554 |
|
|
if (ax25->dama_slave)
|
| 555 |
|
|
ax25_enquiry_response(ax25);
|
| 556 |
|
|
else
|
| 557 |
|
|
dama_enquiry_response(ax25);
|
| 558 |
|
|
}
|
| 559 |
|
|
break;
|
| 560 |
|
|
}
|
| 561 |
|
|
if (ns == ax25->vr) {
|
| 562 |
|
|
ax25->vr = (ax25->vr + 1) % ax25->modulus;
|
| 563 |
|
|
queued = ax25_rx_iframe(ax25, skb);
|
| 564 |
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY)
|
| 565 |
|
|
ax25->vr = ns; /* ax25->vr - 1 */
|
| 566 |
|
|
ax25->condition &= ~AX25_COND_REJECT;
|
| 567 |
|
|
if (pf) {
|
| 568 |
|
|
if (ax25->dama_slave)
|
| 569 |
|
|
dama_enquiry_response(ax25);
|
| 570 |
|
|
else
|
| 571 |
|
|
ax25_enquiry_response(ax25);
|
| 572 |
|
|
} else {
|
| 573 |
|
|
if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
|
| 574 |
|
|
ax25->t2timer = ax25->t2;
|
| 575 |
|
|
ax25->condition |= AX25_COND_ACK_PENDING;
|
| 576 |
|
|
}
|
| 577 |
|
|
}
|
| 578 |
|
|
} else {
|
| 579 |
|
|
if (ax25->condition & AX25_COND_REJECT) {
|
| 580 |
|
|
if (pf) {
|
| 581 |
|
|
if (ax25->dama_slave)
|
| 582 |
|
|
dama_enquiry_response(ax25);
|
| 583 |
|
|
else
|
| 584 |
|
|
ax25_enquiry_response(ax25);
|
| 585 |
|
|
}
|
| 586 |
|
|
} else {
|
| 587 |
|
|
ax25->condition |= AX25_COND_REJECT;
|
| 588 |
|
|
if (ax25->dama_slave)
|
| 589 |
|
|
dama_enquiry_response(ax25);
|
| 590 |
|
|
else
|
| 591 |
|
|
ax25_send_control(ax25, AX25_REJ, pf, AX25_RESPONSE);
|
| 592 |
|
|
ax25->condition &= ~AX25_COND_ACK_PENDING;
|
| 593 |
|
|
}
|
| 594 |
|
|
}
|
| 595 |
|
|
break;
|
| 596 |
|
|
|
| 597 |
|
|
case AX25_FRMR:
|
| 598 |
|
|
case AX25_ILLEGAL:
|
| 599 |
|
|
ax25_establish_data_link(ax25);
|
| 600 |
|
|
ax25->state = AX25_STATE_1;
|
| 601 |
|
|
break;
|
| 602 |
|
|
|
| 603 |
|
|
default:
|
| 604 |
|
|
break;
|
| 605 |
|
|
}
|
| 606 |
|
|
|
| 607 |
|
|
return queued;
|
| 608 |
|
|
}
|
| 609 |
|
|
|
| 610 |
|
|
/*
|
| 611 |
|
|
* Higher level upcall for a LAPB frame
|
| 612 |
|
|
*/
|
| 613 |
|
|
int ax25_process_rx_frame(ax25_cb *ax25, struct sk_buff *skb, int type, int dama)
|
| 614 |
|
|
{
|
| 615 |
|
|
int queued = 0, frametype, ns, nr, pf;
|
| 616 |
|
|
|
| 617 |
|
|
if (ax25->state == AX25_STATE_0)
|
| 618 |
|
|
return 0;
|
| 619 |
|
|
|
| 620 |
|
|
del_timer(&ax25->timer);
|
| 621 |
|
|
|
| 622 |
|
|
frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);
|
| 623 |
|
|
|
| 624 |
|
|
switch (ax25->state) {
|
| 625 |
|
|
case AX25_STATE_1:
|
| 626 |
|
|
queued = ax25_state1_machine(ax25, skb, frametype, pf, type, dama);
|
| 627 |
|
|
break;
|
| 628 |
|
|
case AX25_STATE_2:
|
| 629 |
|
|
queued = ax25_state2_machine(ax25, skb, frametype, pf, type);
|
| 630 |
|
|
break;
|
| 631 |
|
|
case AX25_STATE_3:
|
| 632 |
|
|
queued = ax25_state3_machine(ax25, skb, frametype, ns, nr, pf, type, dama);
|
| 633 |
|
|
break;
|
| 634 |
|
|
case AX25_STATE_4:
|
| 635 |
|
|
queued = ax25_state4_machine(ax25, skb, frametype, ns, nr, pf, type, dama);
|
| 636 |
|
|
break;
|
| 637 |
|
|
}
|
| 638 |
|
|
|
| 639 |
|
|
ax25_set_timer(ax25);
|
| 640 |
|
|
|
| 641 |
|
|
return queued;
|
| 642 |
|
|
}
|
| 643 |
|
|
|
| 644 |
|
|
#endif
|
