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acddc0ed | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4d9ad5dc MS |
2 | /* |
3 | * Multicast traceroute for FRRouting | |
4 | * Copyright (C) 2017 Mladen Sablic | |
4d9ad5dc MS |
5 | */ |
6 | ||
71e55fb2 MS |
7 | /* based on draft-ietf-idmr-traceroute-ipm-07 */ |
8 | ||
4d9ad5dc MS |
9 | #include <zebra.h> |
10 | ||
11 | #include "pimd.h" | |
993e3d8e | 12 | #include "pim_instance.h" |
4d9ad5dc MS |
13 | #include "pim_util.h" |
14 | #include "pim_sock.h" | |
15 | #include "pim_rp.h" | |
16 | #include "pim_oil.h" | |
17 | #include "pim_ifchannel.h" | |
18 | #include "pim_macro.h" | |
19 | #include "pim_igmp_mtrace.h" | |
20 | ||
7fb82673 MS |
21 | static struct in_addr mtrace_primary_address(struct interface *ifp) |
22 | { | |
23 | struct connected *ifc; | |
24 | struct listnode *node; | |
25 | struct in_addr any; | |
26 | struct pim_interface *pim_ifp; | |
27 | ||
28 | if (ifp->info) { | |
29 | pim_ifp = ifp->info; | |
30 | return pim_ifp->primary_address; | |
31 | } | |
32 | ||
33 | any.s_addr = INADDR_ANY; | |
34 | ||
35 | for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, ifc)) { | |
36 | struct prefix *p = ifc->address; | |
37 | ||
38 | if (p->family != AF_INET) | |
39 | continue; | |
40 | ||
41 | if (!CHECK_FLAG(ifc->flags, ZEBRA_IFA_SECONDARY)) | |
42 | return p->u.prefix4; | |
43 | /* in case no primary found, return a secondary */ | |
44 | any = p->u.prefix4; | |
45 | } | |
46 | return any; | |
47 | } | |
48 | ||
71e55fb2 MS |
49 | static bool mtrace_fwd_info_weak(struct pim_instance *pim, |
50 | struct igmp_mtrace *mtracep, | |
51 | struct igmp_mtrace_rsp *rspp, | |
52 | struct interface **ifpp) | |
53 | { | |
54 | struct pim_nexthop nexthop; | |
55 | struct interface *ifp_in; | |
56 | struct in_addr nh_addr; | |
71e55fb2 | 57 | |
975a328e | 58 | nh_addr.s_addr = INADDR_ANY; |
71e55fb2 MS |
59 | |
60 | memset(&nexthop, 0, sizeof(nexthop)); | |
61 | ||
ade155e1 | 62 | if (!pim_nexthop_lookup(pim, &nexthop, mtracep->src_addr, 1)) { |
71e55fb2 MS |
63 | if (PIM_DEBUG_MTRACE) |
64 | zlog_debug("mtrace not found neighbor"); | |
65 | return false; | |
66 | } | |
67 | ||
68 | if (PIM_DEBUG_MTRACE) | |
69 | zlog_debug("mtrace pim_nexthop_lookup OK"); | |
70 | ||
71 | if (PIM_DEBUG_MTRACE) | |
7b942452 | 72 | zlog_debug("mtrace next_hop=%pPAs", &nexthop.mrib_nexthop_addr); |
71e55fb2 | 73 | |
7b942452 | 74 | nh_addr = nexthop.mrib_nexthop_addr; |
71e55fb2 MS |
75 | |
76 | ifp_in = nexthop.interface; | |
77 | ||
78 | /* return interface for forwarding mtrace packets */ | |
79 | *ifpp = ifp_in; | |
80 | ||
81 | /* 6.2.2. 4. Fill in the Incoming Interface Address... */ | |
82 | rspp->incoming = mtrace_primary_address(ifp_in); | |
83 | rspp->prev_hop = nh_addr; | |
84 | rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT); | |
85 | rspp->total = htonl(MTRACE_UNKNOWN_COUNT); | |
86 | rspp->rtg_proto = MTRACE_RTG_PROTO_PIM; | |
87 | return true; | |
88 | } | |
89 | ||
90 | static bool mtrace_fwd_info(struct pim_instance *pim, | |
91 | struct igmp_mtrace *mtracep, | |
92 | struct igmp_mtrace_rsp *rspp, | |
93 | struct interface **ifpp) | |
94 | { | |
6fff2cc6 | 95 | pim_sgaddr sg; |
71e55fb2 MS |
96 | struct pim_upstream *up; |
97 | struct interface *ifp_in; | |
98 | struct in_addr nh_addr; | |
99 | uint32_t total; | |
71e55fb2 | 100 | |
6fff2cc6 | 101 | memset(&sg, 0, sizeof(sg)); |
71e55fb2 MS |
102 | sg.src = mtracep->src_addr; |
103 | sg.grp = mtracep->grp_addr; | |
104 | ||
105 | up = pim_upstream_find(pim, &sg); | |
106 | ||
107 | if (!up) { | |
bca160c6 | 108 | sg.src = PIMADDR_ANY; |
71e55fb2 MS |
109 | up = pim_upstream_find(pim, &sg); |
110 | } | |
111 | ||
112 | if (!up) | |
113 | return false; | |
114 | ||
957d93ea SP |
115 | if (!up->rpf.source_nexthop.interface) { |
116 | if (PIM_DEBUG_TRACE) | |
15569c58 DA |
117 | zlog_debug("%s: up %s RPF is not present", __func__, |
118 | up->sg_str); | |
957d93ea SP |
119 | return false; |
120 | } | |
121 | ||
71e55fb2 | 122 | ifp_in = up->rpf.source_nexthop.interface; |
7b942452 | 123 | nh_addr = up->rpf.source_nexthop.mrib_nexthop_addr; |
71e55fb2 MS |
124 | total = htonl(MTRACE_UNKNOWN_COUNT); |
125 | ||
126 | if (PIM_DEBUG_MTRACE) | |
6b73800b | 127 | zlog_debug("fwd_info: upstream next hop=%pI4", &nh_addr); |
71e55fb2 MS |
128 | |
129 | if (up->channel_oil) | |
130 | total = up->channel_oil->cc.pktcnt; | |
131 | ||
132 | /* return interface for forwarding mtrace packets */ | |
133 | *ifpp = ifp_in; | |
134 | ||
135 | /* 6.2.2. 4. Fill in the Incoming Interface Address... */ | |
136 | rspp->incoming = mtrace_primary_address(ifp_in); | |
137 | rspp->prev_hop = nh_addr; | |
138 | rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT); | |
139 | rspp->total = total; | |
140 | rspp->rtg_proto = MTRACE_RTG_PROTO_PIM; | |
141 | ||
142 | /* 6.2.2. 4. Fill in ... S, and Src Mask */ | |
2a27f13b | 143 | if (!pim_addr_is_any(sg.src)) { |
71e55fb2 MS |
144 | rspp->s = 1; |
145 | rspp->src_mask = MTRACE_SRC_MASK_SOURCE; | |
146 | } else { | |
147 | rspp->s = 0; | |
148 | rspp->src_mask = MTRACE_SRC_MASK_GROUP; | |
149 | } | |
150 | ||
151 | return true; | |
152 | } | |
153 | ||
154 | static void mtrace_rsp_set_fwd_code(struct igmp_mtrace_rsp *mtrace_rspp, | |
155 | enum mtrace_fwd_code fwd_code) | |
156 | { | |
157 | if (mtrace_rspp->fwd_code == MTRACE_FWD_CODE_NO_ERROR) | |
158 | mtrace_rspp->fwd_code = fwd_code; | |
159 | } | |
160 | ||
4d9ad5dc MS |
161 | static void mtrace_rsp_init(struct igmp_mtrace_rsp *mtrace_rspp) |
162 | { | |
163 | mtrace_rspp->arrival = 0; | |
975a328e DA |
164 | mtrace_rspp->incoming.s_addr = INADDR_ANY; |
165 | mtrace_rspp->outgoing.s_addr = INADDR_ANY; | |
166 | mtrace_rspp->prev_hop.s_addr = INADDR_ANY; | |
71e55fb2 MS |
167 | mtrace_rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT); |
168 | mtrace_rspp->out_count = htonl(MTRACE_UNKNOWN_COUNT); | |
169 | mtrace_rspp->total = htonl(MTRACE_UNKNOWN_COUNT); | |
4d9ad5dc MS |
170 | mtrace_rspp->rtg_proto = 0; |
171 | mtrace_rspp->fwd_ttl = 0; | |
172 | mtrace_rspp->mbz = 0; | |
173 | mtrace_rspp->s = 0; | |
174 | mtrace_rspp->src_mask = 0; | |
175 | mtrace_rspp->fwd_code = MTRACE_FWD_CODE_NO_ERROR; | |
176 | } | |
177 | ||
178 | static void mtrace_rsp_debug(uint32_t qry_id, int rsp, | |
179 | struct igmp_mtrace_rsp *mrspp) | |
180 | { | |
531d4171 DS |
181 | struct in_addr incoming = mrspp->incoming; |
182 | struct in_addr outgoing = mrspp->outgoing; | |
183 | struct in_addr prev_hop = mrspp->prev_hop; | |
184 | ||
4d9ad5dc | 185 | zlog_debug( |
6b73800b | 186 | "Rx mt(%d) qid=%ud arr=%x in=%pI4 out=%pI4 prev=%pI4 proto=%d fwd=%d", |
531d4171 DS |
187 | rsp, ntohl(qry_id), mrspp->arrival, &incoming, &outgoing, |
188 | &prev_hop, mrspp->rtg_proto, mrspp->fwd_code); | |
4d9ad5dc MS |
189 | } |
190 | ||
191 | static void mtrace_debug(struct pim_interface *pim_ifp, | |
192 | struct igmp_mtrace *mtracep, int mtrace_len) | |
193 | { | |
f75ecf8d QY |
194 | struct in_addr ga, sa, da, ra; |
195 | ||
196 | ga = mtracep->grp_addr; | |
197 | sa = mtracep->src_addr; | |
198 | da = mtracep->dst_addr; | |
199 | ra = mtracep->rsp_addr; | |
200 | ||
4d9ad5dc | 201 | zlog_debug( |
6b73800b DS |
202 | "Rx mtrace packet incoming on %pI4: hops=%d type=%d size=%d, grp=%pI4, src=%pI4, dst=%pI4 rsp=%pI4 ttl=%d qid=%ud", |
203 | &pim_ifp->primary_address, mtracep->hops, mtracep->type, | |
204 | mtrace_len, &ga, &sa, &da, &ra, mtracep->rsp_ttl, | |
205 | ntohl(mtracep->qry_id)); | |
4d9ad5dc MS |
206 | if (mtrace_len > (int)sizeof(struct igmp_mtrace)) { |
207 | ||
208 | int i; | |
209 | ||
210 | int responses = mtrace_len - sizeof(struct igmp_mtrace); | |
211 | ||
212 | if ((responses % sizeof(struct igmp_mtrace_rsp)) != 0) | |
213 | if (PIM_DEBUG_MTRACE) | |
214 | zlog_debug( | |
3efd0893 | 215 | "Mtrace response block of wrong length"); |
4d9ad5dc MS |
216 | |
217 | responses = responses / sizeof(struct igmp_mtrace_rsp); | |
218 | ||
219 | for (i = 0; i < responses; i++) | |
220 | mtrace_rsp_debug(mtracep->qry_id, i, &mtracep->rsp[i]); | |
221 | } | |
222 | } | |
223 | ||
224 | /* 5.1 Query Arrival Time */ | |
225 | static uint32_t query_arrival_time(void) | |
226 | { | |
227 | struct timeval tv; | |
228 | uint32_t qat; | |
229 | ||
4d9ad5dc MS |
230 | if (gettimeofday(&tv, NULL) < 0) { |
231 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 MS |
232 | zlog_debug("Query arrival time lookup failed: errno=%d: %s", |
233 | errno, safe_strerror(errno)); | |
4d9ad5dc MS |
234 | return 0; |
235 | } | |
236 | /* not sure second offset correct, as I get different value */ | |
237 | qat = ((tv.tv_sec + 32384) << 16) + ((tv.tv_usec << 10) / 15625); | |
238 | ||
239 | return qat; | |
240 | } | |
241 | ||
242 | static int mtrace_send_packet(struct interface *ifp, | |
243 | struct igmp_mtrace *mtracep, | |
244 | size_t mtrace_buf_len, struct in_addr dst_addr, | |
245 | struct in_addr group_addr) | |
246 | { | |
247 | struct sockaddr_in to; | |
4d9ad5dc MS |
248 | socklen_t tolen; |
249 | ssize_t sent; | |
250 | int ret; | |
251 | int fd; | |
d7c0a89a | 252 | uint8_t ttl; |
4d9ad5dc | 253 | |
4d9ad5dc MS |
254 | memset(&to, 0, sizeof(to)); |
255 | to.sin_family = AF_INET; | |
256 | to.sin_addr = dst_addr; | |
257 | tolen = sizeof(to); | |
258 | ||
7fb82673 MS |
259 | if (PIM_DEBUG_MTRACE) { |
260 | struct in_addr if_addr; | |
531d4171 | 261 | struct in_addr rsp_addr = mtracep->rsp_addr; |
7fb82673 MS |
262 | |
263 | if_addr = mtrace_primary_address(ifp); | |
531d4171 DS |
264 | zlog_debug("Sending mtrace packet to %pI4 on %pI4", &rsp_addr, |
265 | &if_addr); | |
7fb82673 | 266 | } |
4d9ad5dc MS |
267 | |
268 | fd = pim_socket_raw(IPPROTO_IGMP); | |
269 | ||
270 | if (fd < 0) | |
271 | return -1; | |
272 | ||
273 | ret = pim_socket_bind(fd, ifp); | |
274 | ||
275 | if (ret < 0) { | |
276 | ret = -1; | |
277 | goto close_fd; | |
278 | } | |
279 | ||
280 | if (IPV4_CLASS_DE(ntohl(dst_addr.s_addr))) { | |
281 | if (IPV4_MC_LINKLOCAL(ntohl(dst_addr.s_addr))) { | |
282 | ttl = 1; | |
283 | } else { | |
284 | if (mtracep->type == PIM_IGMP_MTRACE_RESPONSE) | |
285 | ttl = mtracep->rsp_ttl; | |
286 | else | |
287 | ttl = 64; | |
288 | } | |
289 | ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, | |
290 | sizeof(ttl)); | |
291 | ||
292 | if (ret < 0) { | |
293 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 294 | zlog_debug("Failed to set socket multicast TTL"); |
4d9ad5dc MS |
295 | ret = -1; |
296 | goto close_fd; | |
297 | } | |
298 | } | |
299 | ||
300 | sent = sendto(fd, (char *)mtracep, mtrace_buf_len, MSG_DONTWAIT, | |
301 | (struct sockaddr *)&to, tolen); | |
302 | ||
303 | if (sent != (ssize_t)mtrace_buf_len) { | |
304 | char dst_str[INET_ADDRSTRLEN]; | |
305 | char group_str[INET_ADDRSTRLEN]; | |
306 | ||
307 | pim_inet4_dump("<dst?>", dst_addr, dst_str, sizeof(dst_str)); | |
308 | pim_inet4_dump("<group?>", group_addr, group_str, | |
309 | sizeof(group_str)); | |
310 | if (sent < 0) { | |
311 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 312 | zlog_debug( |
3efd0893 | 313 | "Send mtrace request failed for %s on%s: group=%s msg_size=%zd: errno=%d: %s", |
4d9ad5dc MS |
314 | dst_str, ifp->name, group_str, |
315 | mtrace_buf_len, errno, | |
316 | safe_strerror(errno)); | |
317 | } else { | |
318 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 319 | zlog_debug( |
3efd0893 | 320 | "Send mtrace request failed for %s on %s: group=%s msg_size=%zd: sent=%zd", |
4d9ad5dc MS |
321 | dst_str, ifp->name, group_str, |
322 | mtrace_buf_len, sent); | |
323 | } | |
324 | ret = -1; | |
325 | goto close_fd; | |
326 | } | |
327 | ret = 0; | |
328 | close_fd: | |
329 | close(fd); | |
330 | return ret; | |
331 | } | |
332 | ||
333 | static int mtrace_un_forward_packet(struct pim_instance *pim, struct ip *ip_hdr, | |
334 | struct interface *interface) | |
335 | { | |
336 | struct pim_nexthop nexthop; | |
337 | struct sockaddr_in to; | |
338 | struct interface *if_out; | |
339 | socklen_t tolen; | |
340 | int ret; | |
341 | int fd; | |
342 | int sent; | |
343 | uint16_t checksum; | |
344 | ||
345 | checksum = ip_hdr->ip_sum; | |
346 | ||
347 | ip_hdr->ip_sum = 0; | |
348 | ||
349 | if (checksum != in_cksum(ip_hdr, ip_hdr->ip_hl * 4)) | |
350 | return -1; | |
351 | ||
352 | if (ip_hdr->ip_ttl-- <= 1) | |
353 | return -1; | |
354 | ||
4d9ad5dc | 355 | if (interface == NULL) { |
993b1432 | 356 | memset(&nexthop, 0, sizeof(nexthop)); |
ade155e1 | 357 | if (!pim_nexthop_lookup(pim, &nexthop, ip_hdr->ip_dst, 0)) { |
4d9ad5dc | 358 | if (PIM_DEBUG_MTRACE) |
e7be2bd7 | 359 | zlog_debug( |
3efd0893 | 360 | "Dropping mtrace packet, no route to destination"); |
4d9ad5dc MS |
361 | return -1; |
362 | } | |
363 | ||
364 | if_out = nexthop.interface; | |
365 | } else { | |
366 | if_out = interface; | |
367 | } | |
368 | ||
b46fd500 | 369 | ip_hdr->ip_sum = in_cksum(ip_hdr, ip_hdr->ip_hl * 4); |
370 | ||
371 | fd = pim_socket_raw(IPPROTO_RAW); | |
372 | ||
373 | if (fd < 0) | |
374 | return -1; | |
375 | ||
376 | pim_socket_ip_hdr(fd); | |
377 | ||
4d9ad5dc MS |
378 | ret = pim_socket_bind(fd, if_out); |
379 | ||
380 | if (ret < 0) { | |
381 | close(fd); | |
382 | return -1; | |
383 | } | |
384 | ||
385 | memset(&to, 0, sizeof(to)); | |
386 | to.sin_family = AF_INET; | |
387 | to.sin_addr = ip_hdr->ip_dst; | |
388 | tolen = sizeof(to); | |
389 | ||
390 | sent = sendto(fd, ip_hdr, ntohs(ip_hdr->ip_len), 0, | |
391 | (struct sockaddr *)&to, tolen); | |
392 | ||
393 | close(fd); | |
394 | ||
395 | if (sent < 0) { | |
396 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 397 | zlog_debug( |
3efd0893 | 398 | "Failed to forward mtrace packet: sendto errno=%d, %s", |
4d9ad5dc MS |
399 | errno, safe_strerror(errno)); |
400 | return -1; | |
401 | } | |
402 | ||
403 | if (PIM_DEBUG_MTRACE) { | |
ee2bbf7c MS |
404 | zlog_debug("Fwd mtrace packet len=%u to %pI4 ttl=%u", |
405 | ntohs(ip_hdr->ip_len), &ip_hdr->ip_dst, | |
4d9ad5dc MS |
406 | ip_hdr->ip_ttl); |
407 | } | |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
412 | static int mtrace_mc_forward_packet(struct pim_instance *pim, struct ip *ip_hdr) | |
413 | { | |
6fff2cc6 | 414 | pim_sgaddr sg; |
4d9ad5dc MS |
415 | struct channel_oil *c_oil; |
416 | struct listnode *chnode; | |
417 | struct listnode *chnextnode; | |
418 | struct pim_ifchannel *ch = NULL; | |
419 | int ret = -1; | |
420 | ||
6fff2cc6 | 421 | memset(&sg, 0, sizeof(sg)); |
4d9ad5dc MS |
422 | sg.grp = ip_hdr->ip_dst; |
423 | ||
424 | c_oil = pim_find_channel_oil(pim, &sg); | |
425 | ||
426 | if (c_oil == NULL) { | |
427 | if (PIM_DEBUG_MTRACE) { | |
428 | zlog_debug( | |
ee2bbf7c | 429 | "Dropping mtrace multicast packet len=%u to %pI4 ttl=%u", |
4d9ad5dc | 430 | ntohs(ip_hdr->ip_len), |
ee2bbf7c | 431 | &ip_hdr->ip_dst, ip_hdr->ip_ttl); |
4d9ad5dc MS |
432 | } |
433 | return -1; | |
434 | } | |
435 | if (c_oil->up == NULL) | |
436 | return -1; | |
437 | if (c_oil->up->ifchannels == NULL) | |
438 | return -1; | |
439 | for (ALL_LIST_ELEMENTS(c_oil->up->ifchannels, chnode, chnextnode, ch)) { | |
440 | if (pim_macro_chisin_oiflist(ch)) { | |
441 | int r; | |
442 | ||
443 | r = mtrace_un_forward_packet(pim, ip_hdr, | |
444 | ch->interface); | |
445 | if (r == 0) | |
446 | ret = 0; | |
447 | } | |
448 | } | |
449 | return ret; | |
450 | } | |
451 | ||
452 | ||
453 | static int mtrace_forward_packet(struct pim_instance *pim, struct ip *ip_hdr) | |
454 | { | |
455 | if (IPV4_CLASS_DE(ntohl(ip_hdr->ip_dst.s_addr))) | |
456 | return mtrace_mc_forward_packet(pim, ip_hdr); | |
457 | else | |
458 | return mtrace_un_forward_packet(pim, ip_hdr, NULL); | |
459 | } | |
460 | ||
4d9ad5dc MS |
461 | static int mtrace_send_mc_response(struct pim_instance *pim, |
462 | struct igmp_mtrace *mtracep, | |
463 | size_t mtrace_len) | |
464 | { | |
6fff2cc6 | 465 | pim_sgaddr sg; |
4d9ad5dc MS |
466 | struct channel_oil *c_oil; |
467 | struct listnode *chnode; | |
468 | struct listnode *chnextnode; | |
469 | struct pim_ifchannel *ch = NULL; | |
470 | int ret = -1; | |
471 | ||
6fff2cc6 | 472 | memset(&sg, 0, sizeof(sg)); |
4d9ad5dc MS |
473 | sg.grp = mtracep->rsp_addr; |
474 | ||
475 | c_oil = pim_find_channel_oil(pim, &sg); | |
476 | ||
477 | if (c_oil == NULL) { | |
478 | if (PIM_DEBUG_MTRACE) { | |
531d4171 DS |
479 | struct in_addr rsp_addr = mtracep->rsp_addr; |
480 | ||
4d9ad5dc | 481 | zlog_debug( |
6b73800b | 482 | "Dropping mtrace multicast response packet len=%u to %pI4", |
531d4171 | 483 | (unsigned int)mtrace_len, &rsp_addr); |
4d9ad5dc MS |
484 | } |
485 | return -1; | |
486 | } | |
487 | if (c_oil->up == NULL) | |
488 | return -1; | |
489 | if (c_oil->up->ifchannels == NULL) | |
490 | return -1; | |
491 | for (ALL_LIST_ELEMENTS(c_oil->up->ifchannels, chnode, chnextnode, ch)) { | |
492 | if (pim_macro_chisin_oiflist(ch)) { | |
493 | int r; | |
494 | ||
495 | r = mtrace_send_packet(ch->interface, mtracep, | |
496 | mtrace_len, mtracep->rsp_addr, | |
497 | mtracep->grp_addr); | |
498 | if (r == 0) | |
499 | ret = 0; | |
500 | } | |
501 | } | |
502 | return ret; | |
503 | } | |
504 | ||
71e55fb2 | 505 | /* 6.5 Sending Traceroute Responses */ |
4d9ad5dc MS |
506 | static int mtrace_send_response(struct pim_instance *pim, |
507 | struct igmp_mtrace *mtracep, size_t mtrace_len) | |
508 | { | |
509 | struct pim_nexthop nexthop; | |
4d9ad5dc MS |
510 | |
511 | mtracep->type = PIM_IGMP_MTRACE_RESPONSE; | |
512 | ||
513 | mtracep->checksum = 0; | |
514 | mtracep->checksum = in_cksum((char *)mtracep, mtrace_len); | |
515 | ||
516 | if (IPV4_CLASS_DE(ntohl(mtracep->rsp_addr.s_addr))) { | |
517 | struct pim_rpf *p_rpf; | |
4d9ad5dc MS |
518 | |
519 | if (pim_rp_i_am_rp(pim, mtracep->rsp_addr)) | |
520 | return mtrace_send_mc_response(pim, mtracep, | |
521 | mtrace_len); | |
522 | ||
523 | p_rpf = pim_rp_g(pim, mtracep->rsp_addr); | |
524 | ||
525 | if (p_rpf == NULL) { | |
531d4171 DS |
526 | if (PIM_DEBUG_MTRACE) { |
527 | struct in_addr rsp_addr = mtracep->rsp_addr; | |
528 | ||
529 | zlog_debug("mtrace no RP for %pI4", &rsp_addr); | |
530 | } | |
4d9ad5dc MS |
531 | return -1; |
532 | } | |
533 | nexthop = p_rpf->source_nexthop; | |
534 | if (PIM_DEBUG_MTRACE) | |
535 | zlog_debug("mtrace response to RP"); | |
536 | } else { | |
993b1432 | 537 | memset(&nexthop, 0, sizeof(nexthop)); |
4d9ad5dc | 538 | /* TODO: should use unicast rib lookup */ |
ade155e1 | 539 | if (!pim_nexthop_lookup(pim, &nexthop, mtracep->rsp_addr, 1)) { |
4d9ad5dc | 540 | if (PIM_DEBUG_MTRACE) |
e7be2bd7 | 541 | zlog_debug( |
3efd0893 | 542 | "Dropped response qid=%ud, no route to response address", |
4d9ad5dc MS |
543 | mtracep->qry_id); |
544 | return -1; | |
545 | } | |
546 | } | |
547 | ||
548 | return mtrace_send_packet(nexthop.interface, mtracep, mtrace_len, | |
549 | mtracep->rsp_addr, mtracep->grp_addr); | |
550 | } | |
551 | ||
c5f76fad | 552 | int igmp_mtrace_recv_qry_req(struct gm_sock *igmp, struct ip *ip_hdr, |
4d9ad5dc MS |
553 | struct in_addr from, const char *from_str, |
554 | char *igmp_msg, int igmp_msg_len) | |
555 | { | |
556 | static uint32_t qry_id, qry_src; | |
557 | char mtrace_buf[MTRACE_HDR_SIZE + MTRACE_MAX_HOPS * MTRACE_RSP_SIZE]; | |
4d9ad5dc | 558 | struct interface *ifp; |
3009394b | 559 | struct interface *out_ifp = NULL; |
4d9ad5dc | 560 | struct pim_interface *pim_ifp; |
4d9ad5dc MS |
561 | struct pim_instance *pim; |
562 | struct igmp_mtrace *mtracep; | |
563 | struct igmp_mtrace_rsp *rspp; | |
564 | struct in_addr nh_addr; | |
565 | enum mtrace_fwd_code fwd_code = MTRACE_FWD_CODE_NO_ERROR; | |
4d9ad5dc MS |
566 | size_t r_len; |
567 | int last_rsp_ind = 0; | |
568 | size_t mtrace_len; | |
569 | uint16_t recv_checksum; | |
570 | uint16_t checksum; | |
71e55fb2 MS |
571 | bool reached_source; |
572 | bool fwd_info; | |
4d9ad5dc MS |
573 | |
574 | ifp = igmp->interface; | |
575 | pim_ifp = ifp->info; | |
576 | pim = pim_ifp->pim; | |
577 | ||
578 | /* | |
579 | * 6. Router Behaviour | |
580 | * Check if mtrace packet is addressed elsewhere and forward, | |
581 | * if applicable | |
582 | */ | |
583 | if (!IPV4_CLASS_DE(ntohl(ip_hdr->ip_dst.s_addr))) | |
1e9044be DL |
584 | if (!if_address_is_local(&ip_hdr->ip_dst, AF_INET, |
585 | pim->vrf->vrf_id)) | |
4d9ad5dc MS |
586 | return mtrace_forward_packet(pim, ip_hdr); |
587 | ||
588 | if (igmp_msg_len < (int)sizeof(struct igmp_mtrace)) { | |
589 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 590 | zlog_debug( |
3efd0893 | 591 | "Recv mtrace packet from %s on %s: too short, len=%d, min=%zu", |
4d9ad5dc MS |
592 | from_str, ifp->name, igmp_msg_len, |
593 | sizeof(struct igmp_mtrace)); | |
594 | return -1; | |
595 | } | |
596 | ||
597 | mtracep = (struct igmp_mtrace *)igmp_msg; | |
598 | ||
599 | recv_checksum = mtracep->checksum; | |
600 | ||
601 | mtracep->checksum = 0; | |
602 | ||
603 | checksum = in_cksum(igmp_msg, igmp_msg_len); | |
604 | ||
605 | if (recv_checksum != checksum) { | |
606 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 607 | zlog_debug( |
3efd0893 | 608 | "Recv mtrace packet from %s on %s: checksum mismatch: received=%x computed=%x", |
4d9ad5dc MS |
609 | from_str, ifp->name, recv_checksum, checksum); |
610 | return -1; | |
611 | } | |
612 | ||
21313cbf | 613 | /* Collecting IGMP Rx stats */ |
f2058cb4 | 614 | igmp->igmp_stats.mtrace_req++; |
21313cbf | 615 | |
4d9ad5dc MS |
616 | if (PIM_DEBUG_MTRACE) |
617 | mtrace_debug(pim_ifp, mtracep, igmp_msg_len); | |
618 | ||
619 | /* subtract header from message length */ | |
620 | r_len = igmp_msg_len - sizeof(struct igmp_mtrace); | |
621 | ||
622 | /* Classify mtrace packet, check if it is a query */ | |
623 | if (!r_len) { | |
624 | if (PIM_DEBUG_MTRACE) | |
625 | zlog_debug("Received IGMP multicast traceroute query"); | |
626 | ||
627 | /* 6.1.1 Packet verification */ | |
628 | if (!pim_if_connected_to_source(ifp, mtracep->dst_addr)) { | |
629 | if (IPV4_CLASS_DE(ntohl(ip_hdr->ip_dst.s_addr))) { | |
630 | if (PIM_DEBUG_MTRACE) | |
631 | zlog_debug( | |
3efd0893 | 632 | "Dropping multicast query on wrong interface"); |
4d9ad5dc MS |
633 | return -1; |
634 | } | |
635 | /* Unicast query on wrong interface */ | |
636 | fwd_code = MTRACE_FWD_CODE_WRONG_IF; | |
71e55fb2 MS |
637 | if (PIM_DEBUG_MTRACE) |
638 | zlog_debug("Multicast query on wrong interface"); | |
4d9ad5dc MS |
639 | } |
640 | if (qry_id == mtracep->qry_id && qry_src == from.s_addr) { | |
641 | if (PIM_DEBUG_MTRACE) | |
642 | zlog_debug( | |
3efd0893 | 643 | "Dropping multicast query with duplicate source and id"); |
4d9ad5dc MS |
644 | return -1; |
645 | } | |
646 | qry_id = mtracep->qry_id; | |
647 | qry_src = from.s_addr; | |
648 | } | |
649 | /* if response fields length is equal to a whole number of responses */ | |
650 | else if ((r_len % sizeof(struct igmp_mtrace_rsp)) == 0) { | |
651 | r_len = igmp_msg_len - sizeof(struct igmp_mtrace); | |
652 | ||
653 | if (r_len != 0) | |
654 | last_rsp_ind = r_len / sizeof(struct igmp_mtrace_rsp); | |
655 | if (last_rsp_ind > MTRACE_MAX_HOPS) { | |
656 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 657 | zlog_debug("Mtrace request of excessive size"); |
4d9ad5dc MS |
658 | return -1; |
659 | } | |
660 | } else { | |
661 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 662 | zlog_debug( |
3efd0893 | 663 | "Recv mtrace packet from %s on %s: invalid length %d", |
4d9ad5dc MS |
664 | from_str, ifp->name, igmp_msg_len); |
665 | return -1; | |
666 | } | |
667 | ||
668 | /* 6.2.1 Packet Verification - drop not link-local multicast */ | |
669 | if (IPV4_CLASS_DE(ntohl(ip_hdr->ip_dst.s_addr)) | |
670 | && !IPV4_MC_LINKLOCAL(ntohl(ip_hdr->ip_dst.s_addr))) { | |
671 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 672 | zlog_debug( |
ee2bbf7c MS |
673 | "Recv mtrace packet from %s on %s: not link-local multicast %pI4", |
674 | from_str, ifp->name, &ip_hdr->ip_dst); | |
4d9ad5dc MS |
675 | return -1; |
676 | } | |
677 | ||
678 | /* 6.2.2. Normal Processing */ | |
679 | ||
71e55fb2 | 680 | /* 6.2.2. 1. If there is room in the current buffer? */ |
4d9ad5dc MS |
681 | |
682 | if (last_rsp_ind == MTRACE_MAX_HOPS) { | |
71e55fb2 | 683 | /* ...there was no room... */ |
4d9ad5dc MS |
684 | mtracep->rsp[MTRACE_MAX_HOPS - 1].fwd_code = |
685 | MTRACE_FWD_CODE_NO_SPACE; | |
686 | return mtrace_send_response(pim_ifp->pim, mtracep, | |
687 | igmp_msg_len); | |
688 | } | |
689 | ||
71e55fb2 MS |
690 | /* ...insert new response block... */ |
691 | ||
692 | /* calculate new mtrace lenght with extra response */ | |
4d9ad5dc MS |
693 | mtrace_len = igmp_msg_len + sizeof(struct igmp_mtrace_rsp); |
694 | ||
695 | /* copy received query/request */ | |
696 | memcpy(mtrace_buf, igmp_msg, igmp_msg_len); | |
697 | ||
698 | /* repoint mtracep pointer to copy */ | |
699 | mtracep = (struct igmp_mtrace *)mtrace_buf; | |
700 | ||
701 | /* pointer for extra response field to be filled in */ | |
702 | rspp = &mtracep->rsp[last_rsp_ind]; | |
703 | ||
704 | /* initialize extra response field */ | |
705 | mtrace_rsp_init(rspp); | |
706 | ||
71e55fb2 MS |
707 | /* carry over any error noted when receiving the query */ |
708 | rspp->fwd_code = fwd_code; | |
709 | ||
710 | /* ...and fill in Query Arrival Time... */ | |
4d9ad5dc MS |
711 | rspp->arrival = htonl(query_arrival_time()); |
712 | rspp->outgoing = pim_ifp->primary_address; | |
713 | rspp->out_count = htonl(MTRACE_UNKNOWN_COUNT); | |
71e55fb2 | 714 | rspp->fwd_ttl = 1; |
4d9ad5dc | 715 | |
71e55fb2 | 716 | /* 6.2.2. 2. Attempt to determine the forwarding information... */ |
4d9ad5dc | 717 | |
975a328e | 718 | if (mtracep->grp_addr.s_addr != INADDR_ANY) |
71e55fb2 MS |
719 | fwd_info = mtrace_fwd_info(pim, mtracep, rspp, &out_ifp); |
720 | else | |
721 | fwd_info = mtrace_fwd_info_weak(pim, mtracep, rspp, &out_ifp); | |
4d9ad5dc | 722 | |
71e55fb2 MS |
723 | /* 6.2.2 3. If no forwarding information... */ |
724 | if (!fwd_info) { | |
4d9ad5dc | 725 | if (PIM_DEBUG_MTRACE) |
71e55fb2 MS |
726 | zlog_debug("mtrace not found multicast state"); |
727 | mtrace_rsp_set_fwd_code(rspp, MTRACE_FWD_CODE_NO_ROUTE); | |
728 | /* 6.2.2. 3. forward the packet to requester */ | |
4d9ad5dc MS |
729 | return mtrace_send_response(pim, mtracep, mtrace_len); |
730 | } | |
731 | ||
71e55fb2 | 732 | nh_addr = rspp->prev_hop; |
4d9ad5dc | 733 | |
71e55fb2 | 734 | reached_source = false; |
4d9ad5dc | 735 | |
975a328e | 736 | if (nh_addr.s_addr == INADDR_ANY) { |
71e55fb2 | 737 | /* no pim? i.e. 7.5.3. No Previous Hop */ |
7fb82673 | 738 | if (!out_ifp->info) { |
71e55fb2 MS |
739 | if (PIM_DEBUG_MTRACE) |
740 | zlog_debug("mtrace not found incoming if w/ pim"); | |
741 | mtrace_rsp_set_fwd_code(rspp, | |
742 | MTRACE_FWD_CODE_NO_MULTICAST); | |
7fb82673 MS |
743 | return mtrace_send_response(pim, mtracep, mtrace_len); |
744 | } | |
71e55fb2 | 745 | /* reached source? i.e. 7.5.1 Arriving at source */ |
7fb82673 | 746 | if (pim_if_connected_to_source(out_ifp, mtracep->src_addr)) { |
71e55fb2 | 747 | reached_source = true; |
7fb82673 | 748 | rspp->prev_hop = mtracep->src_addr; |
7fb82673 | 749 | } |
4d9ad5dc MS |
750 | /* |
751 | * 6.4 Forwarding Traceroute Requests: | |
71e55fb2 MS |
752 | * Previous-hop router not known, |
753 | * packet is sent to an appropriate multicast address | |
4d9ad5dc | 754 | */ |
d1b21b96 | 755 | (void)inet_aton(MCAST_ALL_ROUTERS, &nh_addr); |
4d9ad5dc MS |
756 | } |
757 | ||
71e55fb2 | 758 | /* 6.2.2 8. If this router is the Rendez-vous Point */ |
5aed4d13 | 759 | if (mtracep->grp_addr.s_addr != INADDR_ANY && |
760 | pim_rp_i_am_rp(pim, mtracep->grp_addr)) { | |
71e55fb2 MS |
761 | mtrace_rsp_set_fwd_code(rspp, MTRACE_FWD_CODE_REACHED_RP); |
762 | /* 7.7.1. PIM-SM ...RP has not performed source-specific join */ | |
763 | if (rspp->src_mask == MTRACE_SRC_MASK_GROUP) | |
764 | return mtrace_send_response(pim, mtracep, mtrace_len); | |
765 | } | |
766 | ||
767 | /* | |
768 | * 6.4 Forwarding Traceroute Requests: the number of response | |
769 | * blocks exceeds number of responses, so forward to the requester. | |
770 | */ | |
4d9ad5dc MS |
771 | if (mtracep->hops <= (last_rsp_ind + 1)) |
772 | return mtrace_send_response(pim, mtracep, mtrace_len); | |
773 | ||
71e55fb2 MS |
774 | /* 7.5.1. Arriving at source: terminate trace */ |
775 | if (reached_source) | |
776 | return mtrace_send_response(pim, mtracep, mtrace_len); | |
777 | ||
4d9ad5dc MS |
778 | mtracep->checksum = 0; |
779 | ||
780 | mtracep->checksum = in_cksum(mtrace_buf, mtrace_len); | |
781 | ||
71e55fb2 | 782 | /* 6.4 Forwarding Traceroute Requests: response blocks less than req. */ |
4d9ad5dc MS |
783 | return mtrace_send_packet(out_ifp, mtracep, mtrace_len, nh_addr, |
784 | mtracep->grp_addr); | |
785 | } | |
786 | ||
71e55fb2 | 787 | /* 6.3. Traceroute responses */ |
c5f76fad | 788 | int igmp_mtrace_recv_response(struct gm_sock *igmp, struct ip *ip_hdr, |
4d9ad5dc MS |
789 | struct in_addr from, const char *from_str, |
790 | char *igmp_msg, int igmp_msg_len) | |
791 | { | |
792 | static uint32_t qry_id, rsp_dst; | |
793 | struct interface *ifp; | |
794 | struct pim_interface *pim_ifp; | |
795 | struct pim_instance *pim; | |
796 | struct igmp_mtrace *mtracep; | |
797 | uint16_t recv_checksum; | |
798 | uint16_t checksum; | |
799 | ||
800 | ifp = igmp->interface; | |
801 | pim_ifp = ifp->info; | |
802 | pim = pim_ifp->pim; | |
803 | ||
9ebc245a QY |
804 | if (igmp_msg_len < (int)sizeof(struct igmp_mtrace)) { |
805 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 806 | zlog_debug( |
3efd0893 | 807 | "Recv mtrace packet from %s on %s: too short, len=%d, min=%zu", |
9ebc245a QY |
808 | from_str, ifp->name, igmp_msg_len, |
809 | sizeof(struct igmp_mtrace)); | |
810 | return -1; | |
811 | } | |
812 | ||
4d9ad5dc MS |
813 | mtracep = (struct igmp_mtrace *)igmp_msg; |
814 | ||
815 | recv_checksum = mtracep->checksum; | |
816 | ||
817 | mtracep->checksum = 0; | |
818 | ||
819 | checksum = in_cksum(igmp_msg, igmp_msg_len); | |
820 | ||
821 | if (recv_checksum != checksum) { | |
822 | if (PIM_DEBUG_MTRACE) | |
e7be2bd7 | 823 | zlog_debug( |
3efd0893 | 824 | "Recv mtrace response from %s on %s: checksum mismatch: received=%x computed=%x", |
4d9ad5dc MS |
825 | from_str, ifp->name, recv_checksum, checksum); |
826 | return -1; | |
827 | } | |
828 | ||
829 | mtracep->checksum = checksum; | |
830 | ||
21313cbf | 831 | /* Collecting IGMP Rx stats */ |
f2058cb4 | 832 | igmp->igmp_stats.mtrace_rsp++; |
21313cbf | 833 | |
4d9ad5dc MS |
834 | if (PIM_DEBUG_MTRACE) |
835 | mtrace_debug(pim_ifp, mtracep, igmp_msg_len); | |
836 | ||
837 | /* Drop duplicate packets */ | |
838 | if (qry_id == mtracep->qry_id && rsp_dst == ip_hdr->ip_dst.s_addr) { | |
839 | if (PIM_DEBUG_MTRACE) | |
840 | zlog_debug("duplicate mtrace response packet dropped"); | |
841 | return -1; | |
842 | } | |
843 | ||
844 | qry_id = mtracep->qry_id; | |
845 | rsp_dst = ip_hdr->ip_dst.s_addr; | |
846 | ||
847 | return mtrace_forward_packet(pim, ip_hdr); | |
848 | } |