FreeBSD/Linux Kernel Cross Reference
sys/net/if_spppfr.c
1 /*-
2 * Synchronous Frame Relay link level subroutines.
3 * ANSI T1.617-compaible link management signaling
4 * implemented for Frame Relay mode.
5 * Cisco-type Frame Relay framing added, thanks Alex Tutubalin.
6 * Only one DLCI per channel for now.
7 *
8 * Copyright (C) 1994-2000 Cronyx Engineering.
9 * Author: Serge Vakulenko, <vak@cronyx.ru>
10 *
11 * Copyright (C) 1999-2004 Cronyx Engineering.
12 * Author: Kurakin Roman, <rik@cronyx.ru>
13 *
14 * This software is distributed with NO WARRANTIES, not even the implied
15 * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 *
17 * Authors grant any other persons or organisations a permission to use,
18 * modify and redistribute this software in source and binary forms,
19 * as long as this message is kept with the software, all derivative
20 * works or modified versions.
21 *
22 * $Cronyx Id: if_spppfr.c,v 1.1.2.10 2004/06/29 09:02:30 rik Exp $
23 * $FreeBSD: releng/9.2/sys/net/if_spppfr.c 223741 2011-07-03 16:08:38Z bz $
24 */
25
26 #include <sys/param.h>
27
28 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
29 #include "opt_inet.h"
30 #include "opt_inet6.h"
31 #include "opt_ipx.h"
32 #endif
33
34 #ifdef NetBSD1_3
35 # if NetBSD1_3 > 6
36 # include "opt_inet.h"
37 # include "opt_inet6.h"
38 # include "opt_iso.h"
39 # endif
40 #endif
41
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/sockio.h>
46 #include <sys/socket.h>
47 #include <sys/syslog.h>
48 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
49 #include <sys/random.h>
50 #endif
51 #include <sys/malloc.h>
52 #include <sys/mbuf.h>
53
54 #if defined (__OpenBSD__)
55 #include <sys/md5k.h>
56 #else
57 #include <sys/md5.h>
58 #endif
59
60 #include <net/if.h>
61 #include <net/netisr.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/ip.h>
67 #include <net/slcompress.h>
68
69 #if defined (__NetBSD__) || defined (__OpenBSD__)
70 #include <machine/cpu.h> /* XXX for softnet */
71 #endif
72
73 #include <machine/stdarg.h>
74
75 #include <netinet/in_var.h>
76 #ifdef INET
77 #include <netinet/ip.h>
78 #include <netinet/tcp.h>
79 #endif
80
81 #if defined (__FreeBSD__) || defined (__OpenBSD__)
82 # include <netinet/if_ether.h>
83 #else
84 # include <net/ethertypes.h>
85 #endif
86
87 #ifdef IPX
88 #include <netipx/ipx.h>
89 #include <netipx/ipx_if.h>
90 #endif
91
92 #include <net/if_sppp.h>
93
94 /*
95 * Frame Relay.
96 */
97 #define FR_UI 0x03 /* Unnumbered Information */
98 #define FR_IP 0xCC /* IP protocol identifier */
99 #define FR_PADDING 0x00 /* NLPID padding */
100 #define FR_SIGNALING 0x08 /* Q.933/T1.617 signaling identifier */
101 #define FR_SNAP 0x80 /* NLPID snap */
102
103 /*
104 * Header flags.
105 */
106 #define FR_DE 0x02 /* discard eligibility */
107 #define FR_FECN 0x04 /* forward notification */
108 #define FR_BECN 0x08 /* backward notification */
109
110 /*
111 * Signaling message types.
112 */
113 #define FR_MSG_ENQUIRY 0x75 /* status enquiry */
114 #define FR_MSG_STATUS 0x7d /* status */
115
116 #define FR_ENQUIRY_SIZE 14
117
118 /*
119 * Message field types.
120 */
121 #define FR_FLD_RTYPE 0x01 /* report type */
122 #define FR_FLD_VERIFY 0x03 /* link verification */
123 #define FR_FLD_PVC 0x07 /* PVC status */
124 #define FR_FLD_LSHIFT5 0x95 /* locking shift 5 */
125
126 /*
127 * Report types.
128 */
129 #define FR_RTYPE_FULL 0 /* full status */
130 #define FR_RTYPE_SHORT 1 /* link verification only */
131 #define FR_RTYPE_SINGLE 2 /* single PVC status */
132
133 /* PVC status field. */
134 #define FR_DLCI_DELETE 0x04 /* PVC is deleted */
135 #define FR_DLCI_ACTIVE 0x02 /* PVC is operational */
136 #define FR_DLCI_NEW 0x08 /* PVC is new */
137
138 struct arp_req {
139 unsigned short htype; /* hardware type = ARPHRD_FRELAY */
140 unsigned short ptype; /* protocol type = ETHERTYPE_IP */
141 unsigned char halen; /* hardware address length = 2 */
142 unsigned char palen; /* protocol address length = 4 */
143 unsigned short op; /* ARP/RARP/InARP request/reply */
144 unsigned short hsource; /* hardware source address */
145 unsigned short psource1; /* protocol source */
146 unsigned short psource2;
147 unsigned short htarget; /* hardware target address */
148 unsigned short ptarget1; /* protocol target */
149 unsigned short ptarget2;
150 } __packed;
151
152 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 && __FreeBSD_version < 501113
153 #define SPP_FMT "%s%d: "
154 #define SPP_ARGS(ifp) (ifp)->if_name, (ifp)->if_unit
155 #else
156 #define SPP_FMT "%s: "
157 #define SPP_ARGS(ifp) (ifp)->if_xname
158 #endif
159
160 /* almost every function needs these */
161 #define STDDCL \
162 struct ifnet *ifp = SP2IFP(sp); \
163 int debug = ifp->if_flags & IFF_DEBUG
164
165 static void sppp_fr_arp (struct sppp *sp, struct arp_req *req, u_short addr);
166 static void sppp_fr_signal (struct sppp *sp, unsigned char *h, int len);
167
168 void sppp_fr_input (struct sppp *sp, struct mbuf *m)
169 {
170 STDDCL;
171 u_char *h = mtod (m, u_char*);
172 int isr = -1;
173 int dlci, hlen, proto;
174
175 /* Get the DLCI number. */
176 if (m->m_pkthdr.len < 10) {
177 bad: m_freem (m);
178 return;
179 }
180 dlci = (h[0] << 2 & 0x3f0) | (h[1] >> 4 & 0x0f);
181
182 /* Process signaling packets. */
183 if (dlci == 0) {
184 sppp_fr_signal (sp, h, m->m_pkthdr.len);
185 m_freem (m);
186 return;
187 }
188
189 if (dlci != sp->fr_dlci) {
190 if (debug)
191 printf (SPP_FMT "Received packet from invalid DLCI %d\n",
192 SPP_ARGS(ifp), dlci);
193 goto bad;
194 }
195
196 /* Process the packet. */
197 if (ntohs (*(short*) (h+2)) == ETHERTYPE_IP) {
198 /* Prehistoric IP framing? */
199 h[2] = FR_UI;
200 h[3] = FR_IP;
201 }
202 if (h[2] != FR_UI) {
203 if (debug)
204 printf (SPP_FMT "Invalid frame relay header flag 0x%02x\n",
205 SPP_ARGS(ifp), h[2]);
206 goto bad;
207 }
208 switch (h[3]) {
209 default:
210 if (debug)
211 printf (SPP_FMT "Unsupported NLPID 0x%02x\n",
212 SPP_ARGS(ifp), h[3]);
213 goto bad;
214
215 case FR_PADDING:
216 if (h[4] != FR_SNAP) {
217 if (debug)
218 printf (SPP_FMT "Bad NLPID 0x%02x\n",
219 SPP_ARGS(ifp), h[4]);
220 goto bad;
221 }
222 if (h[5] || h[6] || h[7]) {
223 if (debug)
224 printf (SPP_FMT "Bad OID 0x%02x-0x%02x-0x%02x\n",
225 SPP_ARGS(ifp),
226 h[5], h[6], h[7]);
227 goto bad;
228 }
229 proto = ntohs (*(short*) (h+8));
230 if (proto == ETHERTYPE_ARP) {
231 /* Process the ARP request. */
232 if (m->m_pkthdr.len != 10 + sizeof (struct arp_req)) {
233 if (debug)
234 printf (SPP_FMT "Bad ARP request size = %d bytes\n",
235 SPP_ARGS(ifp),
236 m->m_pkthdr.len);
237 goto bad;
238 }
239 sppp_fr_arp (sp, (struct arp_req*) (h + 10),
240 h[0] << 8 | h[1]);
241 m_freem (m);
242 return;
243 }
244 hlen = 10;
245 break;
246
247 case FR_IP:
248 proto = ETHERTYPE_IP;
249 hlen = 4;
250 break;
251 }
252
253 /* Remove frame relay header. */
254 m_adj (m, hlen);
255
256 switch (proto) {
257 default:
258 ++ifp->if_noproto;
259 drop: ++ifp->if_ierrors;
260 ++ifp->if_iqdrops;
261 m_freem (m);
262 return;
263 #ifdef INET
264 case ETHERTYPE_IP:
265 isr = NETISR_IP;
266 break;
267 #endif
268 #ifdef IPX
269 case ETHERTYPE_IPX:
270 isr = NETISR_IPX;
271 break;
272 #endif
273 #ifdef NETATALK
274 case ETHERTYPE_AT:
275 isr = NETISR_ATALK;
276 break;
277 #endif
278 }
279
280 if (! (ifp->if_flags & IFF_UP))
281 goto drop;
282
283 M_SETFIB(m, ifp->if_fib);
284
285 /* Check queue. */
286 if (netisr_queue(isr, m)) { /* (0) on success. */
287 if (debug)
288 log(LOG_DEBUG, SPP_FMT "protocol queue overflow\n",
289 SPP_ARGS(ifp));
290 }
291 }
292
293 /*
294 * Add the frame relay header to the packet.
295 * For IP the header length is 4 bytes,
296 * for all other protocols - 10 bytes (RFC 1490).
297 */
298 struct mbuf *sppp_fr_header (struct sppp *sp, struct mbuf *m,
299 int family)
300 {
301 STDDCL;
302 u_char *h;
303 int type, hlen;
304
305 /* Prepend the space for Frame Relay header. */
306 hlen = (family == AF_INET) ? 4 : 10;
307 M_PREPEND (m, hlen, M_DONTWAIT);
308 if (! m)
309 return 0;
310 h = mtod (m, u_char*);
311
312 /* Fill the header. */
313 h[0] = sp->fr_dlci >> 2 & 0xfc;
314 h[1] = sp->fr_dlci << 4 | 1;
315 h[2] = FR_UI;
316
317 switch (family) {
318 default:
319 if (debug)
320 printf (SPP_FMT "Cannot handle address family %d\n",
321 SPP_ARGS(ifp), family);
322 m_freem (m);
323 return 0;
324 #ifdef INET
325 case AF_INET:
326 #if 0 /* Crashes on fragmented packets */
327 /*
328 * Set the discard eligibility bit, if:
329 * 1) no fragmentation
330 * 2) length > 400 bytes
331 * 3a) the protocol is UDP or
332 * 3b) TCP data (no control bits)
333 */
334 {
335 struct ip *ip = (struct ip*) (h + hlen);
336 struct tcphdr *tcp = (struct tcphdr*) ((long*)ip + ip->ip_hl);
337
338 if (! (ip->ip_off & ~IP_DF) && ip->ip_len > 400 &&
339 (ip->ip_p == IPPROTO_UDP ||
340 ip->ip_p == IPPROTO_TCP && ! tcp->th_flags))
341 h[1] |= FR_DE;
342 }
343 #endif
344 h[3] = FR_IP;
345 return m;
346 #endif
347 #ifdef IPX
348 case AF_IPX:
349 type = ETHERTYPE_IPX;
350 break;
351 #endif
352 #ifdef NS
353 case AF_NS:
354 type = 0x8137;
355 break;
356 #endif
357 #ifdef NETATALK
358 case AF_APPLETALK:
359 type = ETHERTYPE_AT;
360 break;
361 #endif
362 }
363 h[3] = FR_PADDING;
364 h[4] = FR_SNAP;
365 h[5] = 0;
366 h[6] = 0;
367 h[7] = 0;
368 *(short*) (h+8) = htons(type);
369 return m;
370 }
371
372 /*
373 * Send periodical frame relay link verification messages via DLCI 0.
374 * Called every 10 seconds (default value of T391 timer is 10 sec).
375 * Every 6-th message is a full status request
376 * (default value of N391 counter is 6).
377 */
378 void sppp_fr_keepalive (struct sppp *sp)
379 {
380 STDDCL;
381 unsigned char *h, *p;
382 struct mbuf *m;
383
384 MGETHDR (m, M_DONTWAIT, MT_DATA);
385 if (! m)
386 return;
387 m->m_pkthdr.rcvif = 0;
388
389 h = mtod (m, u_char*);
390 p = h;
391 *p++ = 0; /* DLCI = 0 */
392 *p++ = 1;
393 *p++ = FR_UI;
394 *p++ = FR_SIGNALING; /* NLPID = UNI call control */
395
396 *p++ = 0; /* call reference length = 0 */
397 *p++ = FR_MSG_ENQUIRY; /* message type = status enquiry */
398
399 *p++ = FR_FLD_LSHIFT5; /* locking shift 5 */
400
401 *p++ = FR_FLD_RTYPE; /* report type field */
402 *p++ = 1; /* report type length = 1 */
403 if (sp->pp_seq[IDX_LCP] % 6)
404 *p++ = FR_RTYPE_SHORT; /* link verification only */
405 else
406 *p++ = FR_RTYPE_FULL; /* full status needed */
407
408 if (sp->pp_seq[IDX_LCP] >= 255)
409 sp->pp_seq[IDX_LCP] = 0;
410 *p++ = FR_FLD_VERIFY; /* link verification type field */
411 *p++ = 2; /* link verification field length = 2 */
412 *p++ = ++sp->pp_seq[IDX_LCP]; /* our sequence number */
413 *p++ = sp->pp_rseq[IDX_LCP]; /* last received sequence number */
414
415 m->m_pkthdr.len = m->m_len = p - h;
416 if (debug)
417 printf (SPP_FMT "send lmi packet, seq=%d, rseq=%d\n",
418 SPP_ARGS(ifp), (u_char) sp->pp_seq[IDX_LCP],
419 (u_char) sp->pp_rseq[IDX_LCP]);
420
421 if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
422 ++ifp->if_oerrors;
423 }
424
425 /*
426 * Process the frame relay Inverse ARP request.
427 */
428 static void sppp_fr_arp (struct sppp *sp, struct arp_req *req,
429 u_short his_hardware_address)
430 {
431 STDDCL;
432 struct mbuf *m;
433 struct arp_req *reply;
434 u_char *h;
435 u_short my_hardware_address;
436 u_long his_ip_address, my_ip_address;
437
438 if ((ntohs (req->htype) != ARPHRD_FRELAY ||
439 ntohs (req->htype) != 16) || /* for BayNetworks routers */
440 ntohs (req->ptype) != ETHERTYPE_IP) {
441 if (debug)
442 printf (SPP_FMT "Invalid ARP hardware/protocol type = 0x%x/0x%x\n",
443 SPP_ARGS(ifp),
444 ntohs (req->htype), ntohs (req->ptype));
445 return;
446 }
447 if (req->halen != 2 || req->palen != 4) {
448 if (debug)
449 printf (SPP_FMT "Invalid ARP hardware/protocol address length = %d/%d\n",
450 SPP_ARGS(ifp),
451 req->halen, req->palen);
452 return;
453 }
454 switch (ntohs (req->op)) {
455 default:
456 if (debug)
457 printf (SPP_FMT "Invalid ARP op = 0x%x\n",
458 SPP_ARGS(ifp), ntohs (req->op));
459 return;
460
461 case ARPOP_INVREPLY:
462 /* Ignore. */
463 return;
464
465 case ARPOP_INVREQUEST:
466 my_hardware_address = ntohs (req->htarget);
467 his_ip_address = ntohs (req->psource1) << 16 |
468 ntohs (req->psource2);
469 my_ip_address = ntohs (req->ptarget1) << 16 |
470 ntohs (req->ptarget2);
471 break;
472 }
473 if (debug)
474 printf (SPP_FMT "got ARP request, source=0x%04x/%d.%d.%d.%d, target=0x%04x/%d.%d.%d.%d\n",
475 SPP_ARGS(ifp), ntohs (req->hsource),
476 (unsigned char) (his_ip_address >> 24),
477 (unsigned char) (his_ip_address >> 16),
478 (unsigned char) (his_ip_address >> 8),
479 (unsigned char) his_ip_address,
480 my_hardware_address,
481 (unsigned char) (my_ip_address >> 24),
482 (unsigned char) (my_ip_address >> 16),
483 (unsigned char) (my_ip_address >> 8),
484 (unsigned char) my_ip_address);
485
486 sppp_get_ip_addrs (sp, &my_ip_address, 0, 0);
487 if (! my_ip_address)
488 return; /* nothing to reply */
489
490 if (debug)
491 printf (SPP_FMT "send ARP reply, source=0x%04x/%d.%d.%d.%d, target=0x%04x/%d.%d.%d.%d\n",
492 SPP_ARGS(ifp), my_hardware_address,
493 (unsigned char) (my_ip_address >> 24),
494 (unsigned char) (my_ip_address >> 16),
495 (unsigned char) (my_ip_address >> 8),
496 (unsigned char) my_ip_address,
497 his_hardware_address,
498 (unsigned char) (his_ip_address >> 24),
499 (unsigned char) (his_ip_address >> 16),
500 (unsigned char) (his_ip_address >> 8),
501 (unsigned char) his_ip_address);
502
503 /* Send the Inverse ARP reply. */
504 MGETHDR (m, M_DONTWAIT, MT_DATA);
505 if (! m)
506 return;
507 m->m_pkthdr.len = m->m_len = 10 + sizeof (*reply);
508 m->m_pkthdr.rcvif = 0;
509
510 h = mtod (m, u_char*);
511 reply = (struct arp_req*) (h + 10);
512
513 h[0] = his_hardware_address >> 8;
514 h[1] = his_hardware_address;
515 h[2] = FR_UI;
516 h[3] = FR_PADDING;
517 h[4] = FR_SNAP;
518 h[5] = 0;
519 h[6] = 0;
520 h[7] = 0;
521 *(short*) (h+8) = htons (ETHERTYPE_ARP);
522
523 reply->htype = htons (ARPHRD_FRELAY);
524 reply->ptype = htons (ETHERTYPE_IP);
525 reply->halen = 2;
526 reply->palen = 4;
527 reply->op = htons (ARPOP_INVREPLY);
528 reply->hsource = htons (my_hardware_address);
529 reply->psource1 = htonl (my_ip_address);
530 reply->psource2 = htonl (my_ip_address) >> 16;
531 reply->htarget = htons (his_hardware_address);
532 reply->ptarget1 = htonl (his_ip_address);
533 reply->ptarget2 = htonl (his_ip_address) >> 16;
534
535 if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
536 ++ifp->if_oerrors;
537 }
538
539 /*
540 * Process the input signaling packet (DLCI 0).
541 * The implemented protocol is ANSI T1.617 Annex D.
542 */
543 static void sppp_fr_signal (struct sppp *sp, unsigned char *h, int len)
544 {
545 STDDCL;
546 u_char *p;
547 int dlci;
548
549 if (h[2] != FR_UI || h[3] != FR_SIGNALING || h[4] != 0) {
550 if (debug)
551 printf (SPP_FMT "Invalid signaling header\n",
552 SPP_ARGS(ifp));
553 bad: if (debug) {
554 printf ("%02x", *h++);
555 while (--len > 0)
556 printf ("-%02x", *h++);
557 printf ("\n");
558 }
559 return;
560 }
561 if (h[5] == FR_MSG_ENQUIRY) {
562 if (len == FR_ENQUIRY_SIZE &&
563 h[12] == (u_char) sp->pp_seq[IDX_LCP]) {
564 sp->pp_seq[IDX_LCP] = random();
565 printf (SPP_FMT "loopback detected\n",
566 SPP_ARGS(ifp));
567 }
568 return;
569 }
570 if (h[5] != FR_MSG_STATUS) {
571 if (debug)
572 printf (SPP_FMT "Unknown signaling message: 0x%02x\n",
573 SPP_ARGS(ifp), h[5]);
574 goto bad;
575 }
576
577 /* Parse message fields. */
578 for (p=h+6; p<h+len; ) {
579 switch (*p) {
580 default:
581 if (debug)
582 printf (SPP_FMT "Unknown signaling field 0x%x\n",
583 SPP_ARGS(ifp), *p);
584 break;
585 case FR_FLD_LSHIFT5:
586 case FR_FLD_RTYPE:
587 /* Ignore. */
588 break;
589 case FR_FLD_VERIFY:
590 if (p[1] != 2) {
591 if (debug)
592 printf (SPP_FMT "Invalid signaling verify field length %d\n",
593 SPP_ARGS(ifp), p[1]);
594 break;
595 }
596 sp->pp_rseq[IDX_LCP] = p[2];
597 if (debug) {
598 printf (SPP_FMT "got lmi reply rseq=%d, seq=%d",
599 SPP_ARGS(ifp), p[2], p[3]);
600 if (p[3] != (u_char) sp->pp_seq[IDX_LCP])
601 printf (" (really %d)",
602 (u_char) sp->pp_seq[IDX_LCP]);
603 printf ("\n");
604 }
605 break;
606 case FR_FLD_PVC:
607 if (p[1] < 3) {
608 if (debug)
609 printf (SPP_FMT "Invalid PVC status length %d\n",
610 SPP_ARGS(ifp), p[1]);
611 break;
612 }
613 dlci = (p[2] << 4 & 0x3f0) | (p[3] >> 3 & 0x0f);
614 if (! sp->fr_dlci)
615 sp->fr_dlci = dlci;
616 if (sp->fr_status != p[4])
617 printf (SPP_FMT "DLCI %d %s%s\n",
618 SPP_ARGS(ifp), dlci,
619 p[4] & FR_DLCI_DELETE ? "deleted" :
620 p[4] & FR_DLCI_ACTIVE ? "active" : "passive",
621 p[4] & FR_DLCI_NEW ? ", new" : "");
622 sp->fr_status = p[4];
623 break;
624 }
625 if (*p & 0x80)
626 ++p;
627 else if (p < h+len+1 && p[1])
628 p += 2 + p[1];
629 else {
630 if (debug)
631 printf (SPP_FMT "Invalid signaling field 0x%x\n",
632 SPP_ARGS(ifp), *p);
633 goto bad;
634 }
635 }
636 }
Cache object: f0e08bcd31e40d554d461a44f62d37d5
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