ipv4: Do not use dead fib_info entries.
[linux-2.6.git] / net / rose / rose_subr.c
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 (g4klx@g4klx.demon.co.uk)
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 {
37         skb_queue_purge(&sk->sk_write_queue);
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
63 void rose_requeue_frames(struct sock *sk)
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
111         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
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
185         case ROSE_CLEAR_CONFIRMATION:
186         case ROSE_RESET_CONFIRMATION:
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:
213         case ROSE_CLEAR_CONFIRMATION:
214         case ROSE_RESET_REQUEST:
215         case ROSE_RESET_CONFIRMATION:
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)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);
535         rose_stop_idletimer(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 }