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linux/net/rose/rose_subr.c

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/*
* 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.
*
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
*/
#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/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/rose.h>
static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
/*
* This routine purges all of the queues of frames.
*/
void rose_clear_queues(struct sock *sk)
{
skb_queue_purge(&sk->sk_write_queue);
skb_queue_purge(&rose_sk(sk)->ack_queue);
}
/*
* This routine purges the input queue of those frames that have been
* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
* SDL diagram.
*/
void rose_frames_acked(struct sock *sk, unsigned short nr)
{
struct sk_buff *skb;
struct rose_sock *rose = rose_sk(sk);
/*
* Remove all the ack-ed frames from the ack queue.
*/
if (rose->va != nr) {
while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
skb = skb_dequeue(&rose->ack_queue);
kfree_skb(skb);
rose->va = (rose->va + 1) % ROSE_MODULUS;
}
}
}
void rose_requeue_frames(struct sock *sk)
{
struct sk_buff *skb, *skb_prev = NULL;
/*
* Requeue all the un-ack-ed frames on the output queue to be picked
* up by rose_kick. This arrangement handles the possibility of an
* empty output queue.
*/
while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
if (skb_prev == NULL)
skb_queue_head(&sk->sk_write_queue, skb);
else
skb_append(skb_prev, skb, &sk->sk_write_queue);
skb_prev = skb;
}
}
/*
* Validate that the value of nr is between va and vs. Return true or
* false for testing.
*/
int rose_validate_nr(struct sock *sk, unsigned short nr)
{
struct rose_sock *rose = rose_sk(sk);
unsigned short vc = rose->va;
while (vc != rose->vs) {
if (nr == vc) return 1;
vc = (vc + 1) % ROSE_MODULUS;
}
return nr == rose->vs;
}
/*
* This routine is called when the packet layer internally generates a
* control frame.
*/
void rose_write_internal(struct sock *sk, int frametype)
{
struct rose_sock *rose = rose_sk(sk);
struct sk_buff *skb;
unsigned char *dptr;
unsigned char lci1, lci2;
int maxfaclen = 0;
int len, faclen;
int reserve;
reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
len = ROSE_MIN_LEN;
switch (frametype) {
case ROSE_CALL_REQUEST:
len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
maxfaclen = 256;
break;
case ROSE_CALL_ACCEPTED:
case ROSE_CLEAR_REQUEST:
case ROSE_RESET_REQUEST:
len += 2;
break;
}
skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
if (!skb)
return;
/*
* Space for AX.25 header and PID.
*/
skb_reserve(skb, reserve);
dptr = skb_put(skb, len);
lci1 = (rose->lci >> 8) & 0x0F;
lci2 = (rose->lci >> 0) & 0xFF;
switch (frametype) {
case ROSE_CALL_REQUEST:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr++ = frametype;
*dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN);
dptr += ROSE_ADDR_LEN;
memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
dptr += ROSE_ADDR_LEN;
faclen = rose_create_facilities(dptr, rose);
skb_put(skb, faclen);
dptr += faclen;
break;
case ROSE_CALL_ACCEPTED:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr++ = frametype;
*dptr++ = 0x00; /* Address length */
*dptr++ = 0; /* Facilities length */
break;
case ROSE_CLEAR_REQUEST:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr++ = frametype;
*dptr++ = rose->cause;
*dptr++ = rose->diagnostic;
break;
case ROSE_RESET_REQUEST:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr++ = frametype;
*dptr++ = ROSE_DTE_ORIGINATED;
*dptr++ = 0;
break;
case ROSE_RR:
case ROSE_RNR:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr = frametype;
*dptr++ |= (rose->vr << 5) & 0xE0;
break;
case ROSE_CLEAR_CONFIRMATION:
case ROSE_RESET_CONFIRMATION:
*dptr++ = ROSE_GFI | lci1;
*dptr++ = lci2;
*dptr++ = frametype;
break;
default:
printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
kfree_skb(skb);
return;
}
rose_transmit_link(skb, rose->neighbour);
}
int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
{
unsigned char *frame;
frame = skb->data;
*ns = *nr = *q = *d = *m = 0;
switch (frame[2]) {
case ROSE_CALL_REQUEST:
case ROSE_CALL_ACCEPTED:
case ROSE_CLEAR_REQUEST:
case ROSE_CLEAR_CONFIRMATION:
case ROSE_RESET_REQUEST:
case ROSE_RESET_CONFIRMATION:
return frame[2];
default:
break;
}
if ((frame[2] & 0x1F) == ROSE_RR ||
(frame[2] & 0x1F) == ROSE_RNR) {
*nr = (frame[2] >> 5) & 0x07;
return frame[2] & 0x1F;
}
if ((frame[2] & 0x01) == ROSE_DATA) {
*q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
*d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
*m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
*nr = (frame[2] >> 5) & 0x07;
*ns = (frame[2] >> 1) & 0x07;
return ROSE_DATA;
}
return ROSE_ILLEGAL;
}
static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
{
unsigned char *pt;
unsigned char l, lg, n = 0;
int fac_national_digis_received = 0;
do {
switch (*p & 0xC0) {
case 0x00:
if (len < 2)
return -1;
p += 2;
n += 2;
len -= 2;
break;
case 0x40:
if (len < 3)
return -1;
if (*p == FAC_NATIONAL_RAND)
facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
p += 3;
n += 3;
len -= 3;
break;
case 0x80:
if (len < 4)
return -1;
p += 4;
n += 4;
len -= 4;
break;
case 0xC0:
if (len < 2)
return -1;
l = p[1];
if (len < 2 + l)
return -1;
if (*p == FAC_NATIONAL_DEST_DIGI) {
if (!fac_national_digis_received) {
if (l < AX25_ADDR_LEN)
return -1;
memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
facilities->source_ndigis = 1;
}
}
else if (*p == FAC_NATIONAL_SRC_DIGI) {
if (!fac_national_digis_received) {
if (l < AX25_ADDR_LEN)
return -1;
memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
facilities->dest_ndigis = 1;
}
}
else if (*p == FAC_NATIONAL_FAIL_CALL) {
if (l < AX25_ADDR_LEN)
return -1;
memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
}
else if (*p == FAC_NATIONAL_FAIL_ADD) {
if (l < 1 + ROSE_ADDR_LEN)
return -1;
memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
}
else if (*p == FAC_NATIONAL_DIGIS) {
if (l % AX25_ADDR_LEN)
return -1;
fac_national_digis_received = 1;
facilities->source_ndigis = 0;
facilities->dest_ndigis = 0;
for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
if (pt[6] & AX25_HBIT) {
if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
return -1;
memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
} else {
if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
return -1;
memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
}
}
}
p += l + 2;
n += l + 2;
len -= l + 2;
break;
}
} while (*p != 0x00 && len > 0);
return n;
}
static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
{
unsigned char l, n = 0;
char callsign[11];
do {
switch (*p & 0xC0) {
case 0x00:
if (len < 2)
return -1;
p += 2;
n += 2;
len -= 2;
break;
case 0x40:
if (len < 3)
return -1;
p += 3;
n += 3;
len -= 3;
break;
case 0x80:
if (len < 4)
return -1;
p += 4;
n += 4;
len -= 4;
break;
case 0xC0:
if (len < 2)
return -1;
l = p[1];
/* Prevent overflows*/
if (l < 10 || l > 20)
return -1;
if (*p == FAC_CCITT_DEST_NSAP) {
memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
memcpy(callsign, p + 12, l - 10);
callsign[l - 10] = '\0';
asc2ax(&facilities->source_call, callsign);
}
if (*p == FAC_CCITT_SRC_NSAP) {
memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
memcpy(callsign, p + 12, l - 10);
callsign[l - 10] = '\0';
asc2ax(&facilities->dest_call, callsign);
}
p += l + 2;
n += l + 2;
len -= l + 2;
break;
}
} while (*p != 0x00 && len > 0);
return n;
}
int rose_parse_facilities(unsigned char *p, unsigned packet_len,
struct rose_facilities_struct *facilities)
{
int facilities_len, len;
facilities_len = *p++;
if (facilities_len == 0 || (unsigned int)facilities_len > packet_len)
return 0;
while (facilities_len >= 3 && *p == 0x00) {
facilities_len--;
p++;
switch (*p) {
case FAC_NATIONAL: /* National */
len = rose_parse_national(p + 1, facilities, facilities_len - 1);
break;
case FAC_CCITT: /* CCITT */
len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
break;
default:
printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
len = 1;
break;
}
if (len < 0)
return 0;
if (WARN_ON(len >= facilities_len))
return 0;
facilities_len -= len + 1;
p += len + 1;
}
return facilities_len == 0;
}
static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
{
unsigned char *p = buffer + 1;
char *callsign;
char buf[11];
int len, nb;
/* National Facilities */
if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
*p++ = 0x00;
*p++ = FAC_NATIONAL;
if (rose->rand != 0) {
*p++ = FAC_NATIONAL_RAND;
*p++ = (rose->rand >> 8) & 0xFF;
*p++ = (rose->rand >> 0) & 0xFF;
}
/* Sent before older facilities */
if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
int maxdigi = 0;
*p++ = FAC_NATIONAL_DIGIS;
*p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
if (++maxdigi >= ROSE_MAX_DIGIS)
break;
memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
p[6] |= AX25_HBIT;
p += AX25_ADDR_LEN;
}
for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
if (++maxdigi >= ROSE_MAX_DIGIS)
break;
memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
p[6] &= ~AX25_HBIT;
p += AX25_ADDR_LEN;
}
}
/* For compatibility */
if (rose->source_ndigis > 0) {
*p++ = FAC_NATIONAL_SRC_DIGI;
*p++ = AX25_ADDR_LEN;
memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
p += AX25_ADDR_LEN;
}
/* For compatibility */
if (rose->dest_ndigis > 0) {
*p++ = FAC_NATIONAL_DEST_DIGI;
*p++ = AX25_ADDR_LEN;
memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
p += AX25_ADDR_LEN;
}
}
*p++ = 0x00;
*p++ = FAC_CCITT;
*p++ = FAC_CCITT_DEST_NSAP;
callsign = ax2asc(buf, &rose->dest_call);
*p++ = strlen(callsign) + 10;
*p++ = (strlen(callsign) + 9) * 2; /* ??? */
*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
*p++ = ROSE_ADDR_LEN * 2;
memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
p += ROSE_ADDR_LEN;
memcpy(p, callsign, strlen(callsign));
p += strlen(callsign);
*p++ = FAC_CCITT_SRC_NSAP;
callsign = ax2asc(buf, &rose->source_call);
*p++ = strlen(callsign) + 10;
*p++ = (strlen(callsign) + 9) * 2; /* ??? */
*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
*p++ = ROSE_ADDR_LEN * 2;
memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
p += ROSE_ADDR_LEN;
memcpy(p, callsign, strlen(callsign));
p += strlen(callsign);
len = p - buffer;
buffer[0] = len - 1;
return len;
}
void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
{
struct rose_sock *rose = rose_sk(sk);
rose_stop_timer(sk);
rose_stop_idletimer(sk);
rose_clear_queues(sk);
rose->lci = 0;
rose->state = ROSE_STATE_0;
if (cause != -1)
rose->cause = cause;
if (diagnostic != -1)
rose->diagnostic = diagnostic;
sk->sk_state = TCP_CLOSE;
sk->sk_err = reason;
sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(sk, SOCK_DEAD)) {
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DEAD);
}
}
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