2 * Multicast traceroute for FRRouting
3 * Copyright (C) 2017 Mladen Sablic
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; see the file COPYING; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 /* based on draft-ietf-idmr-traceroute-ipm-07 */
29 #include "pim_ifchannel.h"
30 #include "pim_macro.h"
31 #include "pim_igmp_mtrace.h"
33 static struct in_addr
mtrace_primary_address(struct interface
*ifp
)
35 struct connected
*ifc
;
36 struct listnode
*node
;
38 struct pim_interface
*pim_ifp
;
42 return pim_ifp
->primary_address
;
45 any
.s_addr
= INADDR_ANY
;
47 for (ALL_LIST_ELEMENTS_RO(ifp
->connected
, node
, ifc
)) {
48 struct prefix
*p
= ifc
->address
;
50 if (p
->family
!= AF_INET
)
53 if (!CHECK_FLAG(ifc
->flags
, ZEBRA_IFA_SECONDARY
))
55 /* in case no primary found, return a secondary */
61 static bool mtrace_fwd_info_weak(struct pim_instance
*pim
,
62 struct igmp_mtrace
*mtracep
,
63 struct igmp_mtrace_rsp
*rspp
,
64 struct interface
**ifpp
)
66 struct pim_nexthop nexthop
;
67 struct interface
*ifp_in
;
68 struct in_addr nh_addr
;
69 char nexthop_str
[INET_ADDRSTRLEN
];
73 memset(&nexthop
, 0, sizeof(nexthop
));
75 if (!pim_nexthop_lookup(pim
, &nexthop
, mtracep
->src_addr
, 1)) {
77 zlog_debug("mtrace not found neighbor");
82 zlog_debug("mtrace pim_nexthop_lookup OK");
85 zlog_warn("mtrace next_hop=%s",
86 inet_ntop(nexthop
.mrib_nexthop_addr
.family
,
87 &nexthop
.mrib_nexthop_addr
.u
.prefix
,
88 nexthop_str
, sizeof(nexthop_str
)));
90 if (nexthop
.mrib_nexthop_addr
.family
== AF_INET
)
91 nh_addr
= nexthop
.mrib_nexthop_addr
.u
.prefix4
;
93 ifp_in
= nexthop
.interface
;
95 /* return interface for forwarding mtrace packets */
98 /* 6.2.2. 4. Fill in the Incoming Interface Address... */
99 rspp
->incoming
= mtrace_primary_address(ifp_in
);
100 rspp
->prev_hop
= nh_addr
;
101 rspp
->in_count
= htonl(MTRACE_UNKNOWN_COUNT
);
102 rspp
->total
= htonl(MTRACE_UNKNOWN_COUNT
);
103 rspp
->rtg_proto
= MTRACE_RTG_PROTO_PIM
;
107 static bool mtrace_fwd_info(struct pim_instance
*pim
,
108 struct igmp_mtrace
*mtracep
,
109 struct igmp_mtrace_rsp
*rspp
,
110 struct interface
**ifpp
)
113 struct pim_upstream
*up
;
114 struct interface
*ifp_in
;
115 struct in_addr nh_addr
;
117 char up_str
[INET_ADDRSTRLEN
];
119 memset(&sg
, 0, sizeof(struct prefix_sg
));
120 sg
.src
= mtracep
->src_addr
;
121 sg
.grp
= mtracep
->grp_addr
;
123 up
= pim_upstream_find(pim
, &sg
);
127 up
= pim_upstream_find(pim
, &sg
);
133 if (!up
->rpf
.source_nexthop
.interface
) {
135 zlog_debug("%s: up %s RPF is not present",
136 __PRETTY_FUNCTION__
, up
->sg_str
);
140 ifp_in
= up
->rpf
.source_nexthop
.interface
;
141 nh_addr
= up
->rpf
.source_nexthop
.mrib_nexthop_addr
.u
.prefix4
;
142 total
= htonl(MTRACE_UNKNOWN_COUNT
);
144 if (PIM_DEBUG_MTRACE
)
145 zlog_debug("fwd_info: upstream next hop=%s",
146 inet_ntop(AF_INET
, &(nh_addr
), up_str
,
150 total
= up
->channel_oil
->cc
.pktcnt
;
152 /* return interface for forwarding mtrace packets */
155 /* 6.2.2. 4. Fill in the Incoming Interface Address... */
156 rspp
->incoming
= mtrace_primary_address(ifp_in
);
157 rspp
->prev_hop
= nh_addr
;
158 rspp
->in_count
= htonl(MTRACE_UNKNOWN_COUNT
);
160 rspp
->rtg_proto
= MTRACE_RTG_PROTO_PIM
;
162 /* 6.2.2. 4. Fill in ... S, and Src Mask */
165 rspp
->src_mask
= MTRACE_SRC_MASK_SOURCE
;
168 rspp
->src_mask
= MTRACE_SRC_MASK_GROUP
;
174 static void mtrace_rsp_set_fwd_code(struct igmp_mtrace_rsp
*mtrace_rspp
,
175 enum mtrace_fwd_code fwd_code
)
177 if (mtrace_rspp
->fwd_code
== MTRACE_FWD_CODE_NO_ERROR
)
178 mtrace_rspp
->fwd_code
= fwd_code
;
181 static void mtrace_rsp_init(struct igmp_mtrace_rsp
*mtrace_rspp
)
183 mtrace_rspp
->arrival
= 0;
184 mtrace_rspp
->incoming
.s_addr
= 0;
185 mtrace_rspp
->outgoing
.s_addr
= 0;
186 mtrace_rspp
->prev_hop
.s_addr
= 0;
187 mtrace_rspp
->in_count
= htonl(MTRACE_UNKNOWN_COUNT
);
188 mtrace_rspp
->out_count
= htonl(MTRACE_UNKNOWN_COUNT
);
189 mtrace_rspp
->total
= htonl(MTRACE_UNKNOWN_COUNT
);
190 mtrace_rspp
->rtg_proto
= 0;
191 mtrace_rspp
->fwd_ttl
= 0;
192 mtrace_rspp
->mbz
= 0;
194 mtrace_rspp
->src_mask
= 0;
195 mtrace_rspp
->fwd_code
= MTRACE_FWD_CODE_NO_ERROR
;
198 static void mtrace_rsp_debug(uint32_t qry_id
, int rsp
,
199 struct igmp_mtrace_rsp
*mrspp
)
201 char inc_str
[INET_ADDRSTRLEN
];
202 char out_str
[INET_ADDRSTRLEN
];
203 char prv_str
[INET_ADDRSTRLEN
];
206 "Rx mt(%d) qid=%ud arr=%x in=%s out=%s prev=%s proto=%d fwd=%d",
207 rsp
, ntohl(qry_id
), mrspp
->arrival
,
208 inet_ntop(AF_INET
, &(mrspp
->incoming
), inc_str
,
210 inet_ntop(AF_INET
, &(mrspp
->outgoing
), out_str
,
212 inet_ntop(AF_INET
, &(mrspp
->prev_hop
), prv_str
,
214 mrspp
->rtg_proto
, mrspp
->fwd_code
);
217 static void mtrace_debug(struct pim_interface
*pim_ifp
,
218 struct igmp_mtrace
*mtracep
, int mtrace_len
)
220 char inc_str
[INET_ADDRSTRLEN
];
221 char grp_str
[INET_ADDRSTRLEN
];
222 char src_str
[INET_ADDRSTRLEN
];
223 char dst_str
[INET_ADDRSTRLEN
];
224 char rsp_str
[INET_ADDRSTRLEN
];
226 struct in_addr ga
, sa
, da
, ra
;
228 ga
= mtracep
->grp_addr
;
229 sa
= mtracep
->src_addr
;
230 da
= mtracep
->dst_addr
;
231 ra
= mtracep
->rsp_addr
;
234 "Rx mtrace packet incoming on %s: "
235 "hops=%d type=%d size=%d, grp=%s, src=%s,"
236 " dst=%s rsp=%s ttl=%d qid=%ud",
237 inet_ntop(AF_INET
, &(pim_ifp
->primary_address
), inc_str
,
239 mtracep
->hops
, mtracep
->type
, mtrace_len
,
240 inet_ntop(AF_INET
, &ga
, grp_str
,
242 inet_ntop(AF_INET
, &sa
, src_str
,
244 inet_ntop(AF_INET
, &da
, dst_str
,
246 inet_ntop(AF_INET
, &ra
, rsp_str
,
248 mtracep
->rsp_ttl
, ntohl(mtracep
->qry_id
));
249 if (mtrace_len
> (int)sizeof(struct igmp_mtrace
)) {
253 int responses
= mtrace_len
- sizeof(struct igmp_mtrace
);
255 if ((responses
% sizeof(struct igmp_mtrace_rsp
)) != 0)
256 if (PIM_DEBUG_MTRACE
)
258 "Mtrace response block of wrong"
261 responses
= responses
/ sizeof(struct igmp_mtrace_rsp
);
263 for (i
= 0; i
< responses
; i
++)
264 mtrace_rsp_debug(mtracep
->qry_id
, i
, &mtracep
->rsp
[i
]);
268 /* 5.1 Query Arrival Time */
269 static uint32_t query_arrival_time(void)
274 char m_qat
[] = "Query arrival time lookup failed: errno=%d: %s";
276 if (gettimeofday(&tv
, NULL
) < 0) {
277 if (PIM_DEBUG_MTRACE
)
278 zlog_warn(m_qat
, errno
, safe_strerror(errno
));
281 /* not sure second offset correct, as I get different value */
282 qat
= ((tv
.tv_sec
+ 32384) << 16) + ((tv
.tv_usec
<< 10) / 15625);
287 static int mtrace_send_packet(struct interface
*ifp
,
288 struct igmp_mtrace
*mtracep
,
289 size_t mtrace_buf_len
, struct in_addr dst_addr
,
290 struct in_addr group_addr
)
292 struct sockaddr_in to
;
297 char if_str
[INET_ADDRSTRLEN
];
298 char rsp_str
[INET_ADDRSTRLEN
];
301 memset(&to
, 0, sizeof(to
));
302 to
.sin_family
= AF_INET
;
303 to
.sin_addr
= dst_addr
;
306 if (PIM_DEBUG_MTRACE
) {
307 struct in_addr if_addr
;
309 if_addr
= mtrace_primary_address(ifp
);
311 "Sending mtrace packet to %s on %s",
312 inet_ntop(AF_INET
, &mtracep
->rsp_addr
, rsp_str
,
314 inet_ntop(AF_INET
, &if_addr
, if_str
, sizeof(if_str
)));
317 fd
= pim_socket_raw(IPPROTO_IGMP
);
322 ret
= pim_socket_bind(fd
, ifp
);
329 if (IPV4_CLASS_DE(ntohl(dst_addr
.s_addr
))) {
330 if (IPV4_MC_LINKLOCAL(ntohl(dst_addr
.s_addr
))) {
333 if (mtracep
->type
== PIM_IGMP_MTRACE_RESPONSE
)
334 ttl
= mtracep
->rsp_ttl
;
338 ret
= setsockopt(fd
, IPPROTO_IP
, IP_MULTICAST_TTL
, &ttl
,
342 if (PIM_DEBUG_MTRACE
)
343 zlog_warn("Failed to set socket multicast TTL");
349 sent
= sendto(fd
, (char *)mtracep
, mtrace_buf_len
, MSG_DONTWAIT
,
350 (struct sockaddr
*)&to
, tolen
);
352 if (sent
!= (ssize_t
)mtrace_buf_len
) {
353 char dst_str
[INET_ADDRSTRLEN
];
354 char group_str
[INET_ADDRSTRLEN
];
356 pim_inet4_dump("<dst?>", dst_addr
, dst_str
, sizeof(dst_str
));
357 pim_inet4_dump("<group?>", group_addr
, group_str
,
360 if (PIM_DEBUG_MTRACE
)
362 "Send mtrace request failed for %s on"
363 "%s: group=%s msg_size=%zd: errno=%d: "
365 dst_str
, ifp
->name
, group_str
,
366 mtrace_buf_len
, errno
,
367 safe_strerror(errno
));
369 if (PIM_DEBUG_MTRACE
)
371 "Send mtrace request failed for %s on"
372 " %s: group=%s msg_size=%zd: sent=%zd",
373 dst_str
, ifp
->name
, group_str
,
374 mtrace_buf_len
, sent
);
385 static int mtrace_un_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
,
386 struct interface
*interface
)
388 struct pim_nexthop nexthop
;
389 struct sockaddr_in to
;
390 struct interface
*if_out
;
397 checksum
= ip_hdr
->ip_sum
;
401 if (checksum
!= in_cksum(ip_hdr
, ip_hdr
->ip_hl
* 4))
404 if (ip_hdr
->ip_ttl
-- <= 1)
407 ip_hdr
->ip_sum
= in_cksum(ip_hdr
, ip_hdr
->ip_hl
* 4);
409 fd
= pim_socket_raw(IPPROTO_RAW
);
414 pim_socket_ip_hdr(fd
);
416 if (interface
== NULL
) {
417 memset(&nexthop
, 0, sizeof(nexthop
));
418 if (!pim_nexthop_lookup(pim
, &nexthop
, ip_hdr
->ip_dst
, 0)) {
420 if (PIM_DEBUG_MTRACE
)
422 "Dropping mtrace packet, "
423 "no route to destination");
427 if_out
= nexthop
.interface
;
432 ret
= pim_socket_bind(fd
, if_out
);
439 memset(&to
, 0, sizeof(to
));
440 to
.sin_family
= AF_INET
;
441 to
.sin_addr
= ip_hdr
->ip_dst
;
444 sent
= sendto(fd
, ip_hdr
, ntohs(ip_hdr
->ip_len
), 0,
445 (struct sockaddr
*)&to
, tolen
);
450 if (PIM_DEBUG_MTRACE
)
452 "Failed to forward mtrace packet:"
453 " sendto errno=%d, %s",
454 errno
, safe_strerror(errno
));
458 if (PIM_DEBUG_MTRACE
) {
459 zlog_debug("Fwd mtrace packet len=%u to %s ttl=%u",
460 ntohs(ip_hdr
->ip_len
), inet_ntoa(ip_hdr
->ip_dst
),
467 static int mtrace_mc_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
)
470 struct channel_oil
*c_oil
;
471 struct listnode
*chnode
;
472 struct listnode
*chnextnode
;
473 struct pim_ifchannel
*ch
= NULL
;
476 memset(&sg
, 0, sizeof(struct prefix_sg
));
477 sg
.grp
= ip_hdr
->ip_dst
;
479 c_oil
= pim_find_channel_oil(pim
, &sg
);
482 if (PIM_DEBUG_MTRACE
) {
484 "Dropping mtrace multicast packet "
485 "len=%u to %s ttl=%u",
486 ntohs(ip_hdr
->ip_len
),
487 inet_ntoa(ip_hdr
->ip_dst
), ip_hdr
->ip_ttl
);
491 if (c_oil
->up
== NULL
)
493 if (c_oil
->up
->ifchannels
== NULL
)
495 for (ALL_LIST_ELEMENTS(c_oil
->up
->ifchannels
, chnode
, chnextnode
, ch
)) {
496 if (pim_macro_chisin_oiflist(ch
)) {
499 r
= mtrace_un_forward_packet(pim
, ip_hdr
,
509 static int mtrace_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
)
511 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
)))
512 return mtrace_mc_forward_packet(pim
, ip_hdr
);
514 return mtrace_un_forward_packet(pim
, ip_hdr
, NULL
);
517 static int mtrace_send_mc_response(struct pim_instance
*pim
,
518 struct igmp_mtrace
*mtracep
,
522 struct channel_oil
*c_oil
;
523 struct listnode
*chnode
;
524 struct listnode
*chnextnode
;
525 struct pim_ifchannel
*ch
= NULL
;
528 memset(&sg
, 0, sizeof(struct prefix_sg
));
529 sg
.grp
= mtracep
->rsp_addr
;
531 c_oil
= pim_find_channel_oil(pim
, &sg
);
534 if (PIM_DEBUG_MTRACE
) {
536 "Dropping mtrace multicast response packet "
538 (unsigned int)mtrace_len
,
539 inet_ntoa(mtracep
->rsp_addr
));
543 if (c_oil
->up
== NULL
)
545 if (c_oil
->up
->ifchannels
== NULL
)
547 for (ALL_LIST_ELEMENTS(c_oil
->up
->ifchannels
, chnode
, chnextnode
, ch
)) {
548 if (pim_macro_chisin_oiflist(ch
)) {
551 r
= mtrace_send_packet(ch
->interface
, mtracep
,
552 mtrace_len
, mtracep
->rsp_addr
,
561 /* 6.5 Sending Traceroute Responses */
562 static int mtrace_send_response(struct pim_instance
*pim
,
563 struct igmp_mtrace
*mtracep
, size_t mtrace_len
)
565 struct pim_nexthop nexthop
;
567 mtracep
->type
= PIM_IGMP_MTRACE_RESPONSE
;
569 mtracep
->checksum
= 0;
570 mtracep
->checksum
= in_cksum((char *)mtracep
, mtrace_len
);
572 if (IPV4_CLASS_DE(ntohl(mtracep
->rsp_addr
.s_addr
))) {
573 struct pim_rpf
*p_rpf
;
574 char grp_str
[INET_ADDRSTRLEN
];
576 if (pim_rp_i_am_rp(pim
, mtracep
->rsp_addr
))
577 return mtrace_send_mc_response(pim
, mtracep
,
580 p_rpf
= pim_rp_g(pim
, mtracep
->rsp_addr
);
583 if (PIM_DEBUG_MTRACE
)
584 zlog_warn("mtrace no RP for %s",
586 &(mtracep
->rsp_addr
),
587 grp_str
, sizeof(grp_str
)));
590 nexthop
= p_rpf
->source_nexthop
;
591 if (PIM_DEBUG_MTRACE
)
592 zlog_debug("mtrace response to RP");
594 memset(&nexthop
, 0, sizeof(nexthop
));
595 /* TODO: should use unicast rib lookup */
596 if (!pim_nexthop_lookup(pim
, &nexthop
, mtracep
->rsp_addr
, 1)) {
597 if (PIM_DEBUG_MTRACE
)
599 "Dropped response qid=%ud, no route to "
606 return mtrace_send_packet(nexthop
.interface
, mtracep
, mtrace_len
,
607 mtracep
->rsp_addr
, mtracep
->grp_addr
);
610 int igmp_mtrace_recv_qry_req(struct igmp_sock
*igmp
, struct ip
*ip_hdr
,
611 struct in_addr from
, const char *from_str
,
612 char *igmp_msg
, int igmp_msg_len
)
614 static uint32_t qry_id
, qry_src
;
615 char mtrace_buf
[MTRACE_HDR_SIZE
+ MTRACE_MAX_HOPS
* MTRACE_RSP_SIZE
];
616 struct interface
*ifp
;
617 struct interface
*out_ifp
= NULL
;
618 struct pim_interface
*pim_ifp
;
619 struct pim_instance
*pim
;
620 struct igmp_mtrace
*mtracep
;
621 struct igmp_mtrace_rsp
*rspp
;
622 struct in_addr nh_addr
;
623 enum mtrace_fwd_code fwd_code
= MTRACE_FWD_CODE_NO_ERROR
;
625 int last_rsp_ind
= 0;
627 uint16_t recv_checksum
;
632 ifp
= igmp
->interface
;
637 * 6. Router Behaviour
638 * Check if mtrace packet is addressed elsewhere and forward,
641 if (!IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
)))
642 if (!if_lookup_exact_address(&ip_hdr
->ip_dst
, AF_INET
,
644 return mtrace_forward_packet(pim
, ip_hdr
);
646 if (igmp_msg_len
< (int)sizeof(struct igmp_mtrace
)) {
647 if (PIM_DEBUG_MTRACE
)
649 "Recv mtrace packet from %s on %s: too short,"
651 from_str
, ifp
->name
, igmp_msg_len
,
652 sizeof(struct igmp_mtrace
));
656 mtracep
= (struct igmp_mtrace
*)igmp_msg
;
658 recv_checksum
= mtracep
->checksum
;
660 mtracep
->checksum
= 0;
662 checksum
= in_cksum(igmp_msg
, igmp_msg_len
);
664 if (recv_checksum
!= checksum
) {
665 if (PIM_DEBUG_MTRACE
)
667 "Recv mtrace packet from %s on %s: checksum"
668 " mismatch: received=%x computed=%x",
669 from_str
, ifp
->name
, recv_checksum
, checksum
);
673 /* Collecting IGMP Rx stats */
674 igmp
->rx_stats
.mtrace_req
++;
676 if (PIM_DEBUG_MTRACE
)
677 mtrace_debug(pim_ifp
, mtracep
, igmp_msg_len
);
679 /* subtract header from message length */
680 r_len
= igmp_msg_len
- sizeof(struct igmp_mtrace
);
682 /* Classify mtrace packet, check if it is a query */
684 if (PIM_DEBUG_MTRACE
)
685 zlog_debug("Received IGMP multicast traceroute query");
687 /* 6.1.1 Packet verification */
688 if (!pim_if_connected_to_source(ifp
, mtracep
->dst_addr
)) {
689 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
))) {
690 if (PIM_DEBUG_MTRACE
)
692 "Dropping multicast query "
693 "on wrong interface");
696 /* Unicast query on wrong interface */
697 fwd_code
= MTRACE_FWD_CODE_WRONG_IF
;
698 if (PIM_DEBUG_MTRACE
)
699 zlog_debug("Multicast query on wrong interface");
701 if (qry_id
== mtracep
->qry_id
&& qry_src
== from
.s_addr
) {
702 if (PIM_DEBUG_MTRACE
)
704 "Dropping multicast query with "
705 "duplicate source and id");
708 qry_id
= mtracep
->qry_id
;
709 qry_src
= from
.s_addr
;
711 /* if response fields length is equal to a whole number of responses */
712 else if ((r_len
% sizeof(struct igmp_mtrace_rsp
)) == 0) {
713 r_len
= igmp_msg_len
- sizeof(struct igmp_mtrace
);
716 last_rsp_ind
= r_len
/ sizeof(struct igmp_mtrace_rsp
);
717 if (last_rsp_ind
> MTRACE_MAX_HOPS
) {
718 if (PIM_DEBUG_MTRACE
)
719 zlog_warn("Mtrace request of excessive size");
723 if (PIM_DEBUG_MTRACE
)
725 "Recv mtrace packet from %s on %s: "
727 from_str
, ifp
->name
, igmp_msg_len
);
731 /* 6.2.1 Packet Verification - drop not link-local multicast */
732 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
))
733 && !IPV4_MC_LINKLOCAL(ntohl(ip_hdr
->ip_dst
.s_addr
))) {
734 if (PIM_DEBUG_MTRACE
)
736 "Recv mtrace packet from %s on %s:"
737 " not link-local multicast %s",
738 from_str
, ifp
->name
, inet_ntoa(ip_hdr
->ip_dst
));
742 /* 6.2.2. Normal Processing */
744 /* 6.2.2. 1. If there is room in the current buffer? */
746 if (last_rsp_ind
== MTRACE_MAX_HOPS
) {
747 /* ...there was no room... */
748 mtracep
->rsp
[MTRACE_MAX_HOPS
- 1].fwd_code
=
749 MTRACE_FWD_CODE_NO_SPACE
;
750 return mtrace_send_response(pim_ifp
->pim
, mtracep
,
754 /* ...insert new response block... */
756 /* calculate new mtrace lenght with extra response */
757 mtrace_len
= igmp_msg_len
+ sizeof(struct igmp_mtrace_rsp
);
759 /* copy received query/request */
760 memcpy(mtrace_buf
, igmp_msg
, igmp_msg_len
);
762 /* repoint mtracep pointer to copy */
763 mtracep
= (struct igmp_mtrace
*)mtrace_buf
;
765 /* pointer for extra response field to be filled in */
766 rspp
= &mtracep
->rsp
[last_rsp_ind
];
768 /* initialize extra response field */
769 mtrace_rsp_init(rspp
);
771 /* carry over any error noted when receiving the query */
772 rspp
->fwd_code
= fwd_code
;
774 /* ...and fill in Query Arrival Time... */
775 rspp
->arrival
= htonl(query_arrival_time());
776 rspp
->outgoing
= pim_ifp
->primary_address
;
777 rspp
->out_count
= htonl(MTRACE_UNKNOWN_COUNT
);
780 /* 6.2.2. 2. Attempt to determine the forwarding information... */
782 if (mtracep
->grp_addr
.s_addr
)
783 fwd_info
= mtrace_fwd_info(pim
, mtracep
, rspp
, &out_ifp
);
785 fwd_info
= mtrace_fwd_info_weak(pim
, mtracep
, rspp
, &out_ifp
);
787 /* 6.2.2 3. If no forwarding information... */
789 if (PIM_DEBUG_MTRACE
)
790 zlog_debug("mtrace not found multicast state");
791 mtrace_rsp_set_fwd_code(rspp
, MTRACE_FWD_CODE_NO_ROUTE
);
792 /* 6.2.2. 3. forward the packet to requester */
793 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
796 nh_addr
= rspp
->prev_hop
;
798 reached_source
= false;
800 if (nh_addr
.s_addr
== 0) {
801 /* no pim? i.e. 7.5.3. No Previous Hop */
802 if (!out_ifp
->info
) {
803 if (PIM_DEBUG_MTRACE
)
804 zlog_debug("mtrace not found incoming if w/ pim");
805 mtrace_rsp_set_fwd_code(rspp
,
806 MTRACE_FWD_CODE_NO_MULTICAST
);
807 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
809 /* reached source? i.e. 7.5.1 Arriving at source */
810 if (pim_if_connected_to_source(out_ifp
, mtracep
->src_addr
)) {
811 reached_source
= true;
812 rspp
->prev_hop
= mtracep
->src_addr
;
815 * 6.4 Forwarding Traceroute Requests:
816 * Previous-hop router not known,
817 * packet is sent to an appropriate multicast address
819 (void)inet_aton(MCAST_ALL_ROUTERS
, &nh_addr
);
822 /* 6.2.2 8. If this router is the Rendez-vous Point */
823 if (pim_rp_i_am_rp(pim
, mtracep
->grp_addr
)) {
824 mtrace_rsp_set_fwd_code(rspp
, MTRACE_FWD_CODE_REACHED_RP
);
825 /* 7.7.1. PIM-SM ...RP has not performed source-specific join */
826 if (rspp
->src_mask
== MTRACE_SRC_MASK_GROUP
)
827 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
831 * 6.4 Forwarding Traceroute Requests: the number of response
832 * blocks exceeds number of responses, so forward to the requester.
834 if (mtracep
->hops
<= (last_rsp_ind
+ 1))
835 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
837 /* 7.5.1. Arriving at source: terminate trace */
839 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
841 mtracep
->checksum
= 0;
843 mtracep
->checksum
= in_cksum(mtrace_buf
, mtrace_len
);
845 /* 6.4 Forwarding Traceroute Requests: response blocks less than req. */
846 return mtrace_send_packet(out_ifp
, mtracep
, mtrace_len
, nh_addr
,
850 /* 6.3. Traceroute responses */
851 int igmp_mtrace_recv_response(struct igmp_sock
*igmp
, struct ip
*ip_hdr
,
852 struct in_addr from
, const char *from_str
,
853 char *igmp_msg
, int igmp_msg_len
)
855 static uint32_t qry_id
, rsp_dst
;
856 struct interface
*ifp
;
857 struct pim_interface
*pim_ifp
;
858 struct pim_instance
*pim
;
859 struct igmp_mtrace
*mtracep
;
860 uint16_t recv_checksum
;
863 ifp
= igmp
->interface
;
867 mtracep
= (struct igmp_mtrace
*)igmp_msg
;
869 recv_checksum
= mtracep
->checksum
;
871 mtracep
->checksum
= 0;
873 checksum
= in_cksum(igmp_msg
, igmp_msg_len
);
875 if (recv_checksum
!= checksum
) {
876 if (PIM_DEBUG_MTRACE
)
878 "Recv mtrace response from %s on %s: checksum"
879 " mismatch: received=%x computed=%x",
880 from_str
, ifp
->name
, recv_checksum
, checksum
);
884 mtracep
->checksum
= checksum
;
886 /* Collecting IGMP Rx stats */
887 igmp
->rx_stats
.mtrace_rsp
++;
889 if (PIM_DEBUG_MTRACE
)
890 mtrace_debug(pim_ifp
, mtracep
, igmp_msg_len
);
892 /* Drop duplicate packets */
893 if (qry_id
== mtracep
->qry_id
&& rsp_dst
== ip_hdr
->ip_dst
.s_addr
) {
894 if (PIM_DEBUG_MTRACE
)
895 zlog_debug("duplicate mtrace response packet dropped");
899 qry_id
= mtracep
->qry_id
;
900 rsp_dst
= ip_hdr
->ip_dst
.s_addr
;
902 return mtrace_forward_packet(pim
, ip_hdr
);