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rose_subr.c
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1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright (C) Jonathan Naylor G4KLX ([email protected])
8  */
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/in.h>
13 #include <linux/kernel.h>
14 #include <linux/timer.h>
15 #include <linux/string.h>
16 #include <linux/sockios.h>
17 #include <linux/net.h>
18 #include <linux/slab.h>
19 #include <net/ax25.h>
20 #include <linux/inet.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h>
25 #include <linux/fcntl.h>
26 #include <linux/mm.h>
27 #include <linux/interrupt.h>
28 #include <net/rose.h>
29 
30 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
31 
32 /*
33  * This routine purges all of the queues of frames.
34  */
35 void rose_clear_queues(struct sock *sk)
36 {
38  skb_queue_purge(&rose_sk(sk)->ack_queue);
39 }
40 
41 /*
42  * This routine purges the input queue of those frames that have been
43  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
44  * SDL diagram.
45  */
46 void rose_frames_acked(struct sock *sk, unsigned short nr)
47 {
48  struct sk_buff *skb;
49  struct rose_sock *rose = rose_sk(sk);
50 
51  /*
52  * Remove all the ack-ed frames from the ack queue.
53  */
54  if (rose->va != nr) {
55  while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
56  skb = skb_dequeue(&rose->ack_queue);
57  kfree_skb(skb);
58  rose->va = (rose->va + 1) % ROSE_MODULUS;
59  }
60  }
61 }
62 
64 {
65  struct sk_buff *skb, *skb_prev = NULL;
66 
67  /*
68  * Requeue all the un-ack-ed frames on the output queue to be picked
69  * up by rose_kick. This arrangement handles the possibility of an
70  * empty output queue.
71  */
72  while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
73  if (skb_prev == NULL)
74  skb_queue_head(&sk->sk_write_queue, skb);
75  else
76  skb_append(skb_prev, skb, &sk->sk_write_queue);
77  skb_prev = skb;
78  }
79 }
80 
81 /*
82  * Validate that the value of nr is between va and vs. Return true or
83  * false for testing.
84  */
85 int rose_validate_nr(struct sock *sk, unsigned short nr)
86 {
87  struct rose_sock *rose = rose_sk(sk);
88  unsigned short vc = rose->va;
89 
90  while (vc != rose->vs) {
91  if (nr == vc) return 1;
92  vc = (vc + 1) % ROSE_MODULUS;
93  }
94 
95  return nr == rose->vs;
96 }
97 
98 /*
99  * This routine is called when the packet layer internally generates a
100  * control frame.
101  */
102 void rose_write_internal(struct sock *sk, int frametype)
103 {
104  struct rose_sock *rose = rose_sk(sk);
105  struct sk_buff *skb;
106  unsigned char *dptr;
107  unsigned char lci1, lci2;
108  char buffer[100];
109  int len, faclen = 0;
110 
112 
113  switch (frametype) {
114  case ROSE_CALL_REQUEST:
115  len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
116  faclen = rose_create_facilities(buffer, rose);
117  len += faclen;
118  break;
119  case ROSE_CALL_ACCEPTED:
120  case ROSE_CLEAR_REQUEST:
121  case ROSE_RESET_REQUEST:
122  len += 2;
123  break;
124  }
125 
126  if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
127  return;
128 
129  /*
130  * Space for AX.25 header and PID.
131  */
132  skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);
133 
134  dptr = skb_put(skb, skb_tailroom(skb));
135 
136  lci1 = (rose->lci >> 8) & 0x0F;
137  lci2 = (rose->lci >> 0) & 0xFF;
138 
139  switch (frametype) {
140  case ROSE_CALL_REQUEST:
141  *dptr++ = ROSE_GFI | lci1;
142  *dptr++ = lci2;
143  *dptr++ = frametype;
144  *dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
145  memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN);
146  dptr += ROSE_ADDR_LEN;
147  memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
148  dptr += ROSE_ADDR_LEN;
149  memcpy(dptr, buffer, faclen);
150  dptr += faclen;
151  break;
152 
153  case ROSE_CALL_ACCEPTED:
154  *dptr++ = ROSE_GFI | lci1;
155  *dptr++ = lci2;
156  *dptr++ = frametype;
157  *dptr++ = 0x00; /* Address length */
158  *dptr++ = 0; /* Facilities length */
159  break;
160 
161  case ROSE_CLEAR_REQUEST:
162  *dptr++ = ROSE_GFI | lci1;
163  *dptr++ = lci2;
164  *dptr++ = frametype;
165  *dptr++ = rose->cause;
166  *dptr++ = rose->diagnostic;
167  break;
168 
169  case ROSE_RESET_REQUEST:
170  *dptr++ = ROSE_GFI | lci1;
171  *dptr++ = lci2;
172  *dptr++ = frametype;
173  *dptr++ = ROSE_DTE_ORIGINATED;
174  *dptr++ = 0;
175  break;
176 
177  case ROSE_RR:
178  case ROSE_RNR:
179  *dptr++ = ROSE_GFI | lci1;
180  *dptr++ = lci2;
181  *dptr = frametype;
182  *dptr++ |= (rose->vr << 5) & 0xE0;
183  break;
184 
187  *dptr++ = ROSE_GFI | lci1;
188  *dptr++ = lci2;
189  *dptr++ = frametype;
190  break;
191 
192  default:
193  printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
194  kfree_skb(skb);
195  return;
196  }
197 
198  rose_transmit_link(skb, rose->neighbour);
199 }
200 
201 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
202 {
203  unsigned char *frame;
204 
205  frame = skb->data;
206 
207  *ns = *nr = *q = *d = *m = 0;
208 
209  switch (frame[2]) {
210  case ROSE_CALL_REQUEST:
211  case ROSE_CALL_ACCEPTED:
212  case ROSE_CLEAR_REQUEST:
214  case ROSE_RESET_REQUEST:
216  return frame[2];
217  default:
218  break;
219  }
220 
221  if ((frame[2] & 0x1F) == ROSE_RR ||
222  (frame[2] & 0x1F) == ROSE_RNR) {
223  *nr = (frame[2] >> 5) & 0x07;
224  return frame[2] & 0x1F;
225  }
226 
227  if ((frame[2] & 0x01) == ROSE_DATA) {
228  *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
229  *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
230  *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
231  *nr = (frame[2] >> 5) & 0x07;
232  *ns = (frame[2] >> 1) & 0x07;
233  return ROSE_DATA;
234  }
235 
236  return ROSE_ILLEGAL;
237 }
238 
239 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
240 {
241  unsigned char *pt;
242  unsigned char l, lg, n = 0;
243  int fac_national_digis_received = 0;
244 
245  do {
246  switch (*p & 0xC0) {
247  case 0x00:
248  if (len < 2)
249  return -1;
250  p += 2;
251  n += 2;
252  len -= 2;
253  break;
254 
255  case 0x40:
256  if (len < 3)
257  return -1;
258  if (*p == FAC_NATIONAL_RAND)
259  facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
260  p += 3;
261  n += 3;
262  len -= 3;
263  break;
264 
265  case 0x80:
266  if (len < 4)
267  return -1;
268  p += 4;
269  n += 4;
270  len -= 4;
271  break;
272 
273  case 0xC0:
274  if (len < 2)
275  return -1;
276  l = p[1];
277  if (len < 2 + l)
278  return -1;
279  if (*p == FAC_NATIONAL_DEST_DIGI) {
280  if (!fac_national_digis_received) {
281  if (l < AX25_ADDR_LEN)
282  return -1;
283  memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
284  facilities->source_ndigis = 1;
285  }
286  }
287  else if (*p == FAC_NATIONAL_SRC_DIGI) {
288  if (!fac_national_digis_received) {
289  if (l < AX25_ADDR_LEN)
290  return -1;
291  memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
292  facilities->dest_ndigis = 1;
293  }
294  }
295  else if (*p == FAC_NATIONAL_FAIL_CALL) {
296  if (l < AX25_ADDR_LEN)
297  return -1;
298  memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
299  }
300  else if (*p == FAC_NATIONAL_FAIL_ADD) {
301  if (l < 1 + ROSE_ADDR_LEN)
302  return -1;
303  memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
304  }
305  else if (*p == FAC_NATIONAL_DIGIS) {
306  if (l % AX25_ADDR_LEN)
307  return -1;
308  fac_national_digis_received = 1;
309  facilities->source_ndigis = 0;
310  facilities->dest_ndigis = 0;
311  for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
312  if (pt[6] & AX25_HBIT) {
313  if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
314  return -1;
315  memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
316  } else {
317  if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
318  return -1;
319  memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
320  }
321  }
322  }
323  p += l + 2;
324  n += l + 2;
325  len -= l + 2;
326  break;
327  }
328  } while (*p != 0x00 && len > 0);
329 
330  return n;
331 }
332 
333 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
334 {
335  unsigned char l, n = 0;
336  char callsign[11];
337 
338  do {
339  switch (*p & 0xC0) {
340  case 0x00:
341  if (len < 2)
342  return -1;
343  p += 2;
344  n += 2;
345  len -= 2;
346  break;
347 
348  case 0x40:
349  if (len < 3)
350  return -1;
351  p += 3;
352  n += 3;
353  len -= 3;
354  break;
355 
356  case 0x80:
357  if (len < 4)
358  return -1;
359  p += 4;
360  n += 4;
361  len -= 4;
362  break;
363 
364  case 0xC0:
365  if (len < 2)
366  return -1;
367  l = p[1];
368 
369  /* Prevent overflows*/
370  if (l < 10 || l > 20)
371  return -1;
372 
373  if (*p == FAC_CCITT_DEST_NSAP) {
374  memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
375  memcpy(callsign, p + 12, l - 10);
376  callsign[l - 10] = '\0';
377  asc2ax(&facilities->source_call, callsign);
378  }
379  if (*p == FAC_CCITT_SRC_NSAP) {
380  memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
381  memcpy(callsign, p + 12, l - 10);
382  callsign[l - 10] = '\0';
383  asc2ax(&facilities->dest_call, callsign);
384  }
385  p += l + 2;
386  n += l + 2;
387  len -= l + 2;
388  break;
389  }
390  } while (*p != 0x00 && len > 0);
391 
392  return n;
393 }
394 
395 int rose_parse_facilities(unsigned char *p, unsigned packet_len,
396  struct rose_facilities_struct *facilities)
397 {
398  int facilities_len, len;
399 
400  facilities_len = *p++;
401 
402  if (facilities_len == 0 || (unsigned int)facilities_len > packet_len)
403  return 0;
404 
405  while (facilities_len >= 3 && *p == 0x00) {
406  facilities_len--;
407  p++;
408 
409  switch (*p) {
410  case FAC_NATIONAL: /* National */
411  len = rose_parse_national(p + 1, facilities, facilities_len - 1);
412  break;
413 
414  case FAC_CCITT: /* CCITT */
415  len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
416  break;
417 
418  default:
419  printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
420  len = 1;
421  break;
422  }
423 
424  if (len < 0)
425  return 0;
426  if (WARN_ON(len >= facilities_len))
427  return 0;
428  facilities_len -= len + 1;
429  p += len + 1;
430  }
431 
432  return facilities_len == 0;
433 }
434 
435 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
436 {
437  unsigned char *p = buffer + 1;
438  char *callsign;
439  char buf[11];
440  int len, nb;
441 
442  /* National Facilities */
443  if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
444  *p++ = 0x00;
445  *p++ = FAC_NATIONAL;
446 
447  if (rose->rand != 0) {
448  *p++ = FAC_NATIONAL_RAND;
449  *p++ = (rose->rand >> 8) & 0xFF;
450  *p++ = (rose->rand >> 0) & 0xFF;
451  }
452 
453  /* Sent before older facilities */
454  if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
455  int maxdigi = 0;
456  *p++ = FAC_NATIONAL_DIGIS;
457  *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
458  for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
459  if (++maxdigi >= ROSE_MAX_DIGIS)
460  break;
461  memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
462  p[6] |= AX25_HBIT;
463  p += AX25_ADDR_LEN;
464  }
465  for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
466  if (++maxdigi >= ROSE_MAX_DIGIS)
467  break;
468  memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
469  p[6] &= ~AX25_HBIT;
470  p += AX25_ADDR_LEN;
471  }
472  }
473 
474  /* For compatibility */
475  if (rose->source_ndigis > 0) {
476  *p++ = FAC_NATIONAL_SRC_DIGI;
477  *p++ = AX25_ADDR_LEN;
478  memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
479  p += AX25_ADDR_LEN;
480  }
481 
482  /* For compatibility */
483  if (rose->dest_ndigis > 0) {
484  *p++ = FAC_NATIONAL_DEST_DIGI;
485  *p++ = AX25_ADDR_LEN;
486  memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
487  p += AX25_ADDR_LEN;
488  }
489  }
490 
491  *p++ = 0x00;
492  *p++ = FAC_CCITT;
493 
494  *p++ = FAC_CCITT_DEST_NSAP;
495 
496  callsign = ax2asc(buf, &rose->dest_call);
497 
498  *p++ = strlen(callsign) + 10;
499  *p++ = (strlen(callsign) + 9) * 2; /* ??? */
500 
501  *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
502  *p++ = ROSE_ADDR_LEN * 2;
503  memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
504  p += ROSE_ADDR_LEN;
505 
506  memcpy(p, callsign, strlen(callsign));
507  p += strlen(callsign);
508 
509  *p++ = FAC_CCITT_SRC_NSAP;
510 
511  callsign = ax2asc(buf, &rose->source_call);
512 
513  *p++ = strlen(callsign) + 10;
514  *p++ = (strlen(callsign) + 9) * 2; /* ??? */
515 
516  *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
517  *p++ = ROSE_ADDR_LEN * 2;
518  memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
519  p += ROSE_ADDR_LEN;
520 
521  memcpy(p, callsign, strlen(callsign));
522  p += strlen(callsign);
523 
524  len = p - buffer;
525  buffer[0] = len - 1;
526 
527  return len;
528 }
529 
530 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
531 {
532  struct rose_sock *rose = rose_sk(sk);
533 
534  rose_stop_timer(sk);
536 
537  rose_clear_queues(sk);
538 
539  rose->lci = 0;
540  rose->state = ROSE_STATE_0;
541 
542  if (cause != -1)
543  rose->cause = cause;
544 
545  if (diagnostic != -1)
546  rose->diagnostic = diagnostic;
547 
548  sk->sk_state = TCP_CLOSE;
549  sk->sk_err = reason;
550  sk->sk_shutdown |= SEND_SHUTDOWN;
551 
552  if (!sock_flag(sk, SOCK_DEAD)) {
553  sk->sk_state_change(sk);
554  sock_set_flag(sk, SOCK_DEAD);
555  }
556 }