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
];
71 nh_addr
.s_addr
= INADDR_ANY
;
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
);
126 sg
.src
.s_addr
= INADDR_ANY
;
127 up
= pim_upstream_find(pim
, &sg
);
133 if (!up
->rpf
.source_nexthop
.interface
) {
135 zlog_debug("%s: up %s RPF is not present", __func__
,
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 */
163 if (sg
.src
.s_addr
!= INADDR_ANY
) {
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
= INADDR_ANY
;
185 mtrace_rspp
->outgoing
.s_addr
= INADDR_ANY
;
186 mtrace_rspp
->prev_hop
.s_addr
= INADDR_ANY
;
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: hops=%d type=%d size=%d, grp=%s, src=%s, dst=%s rsp=%s ttl=%d qid=%ud",
235 inet_ntop(AF_INET
, &(pim_ifp
->primary_address
), inc_str
,
237 mtracep
->hops
, mtracep
->type
, mtrace_len
,
238 inet_ntop(AF_INET
, &ga
, grp_str
,
240 inet_ntop(AF_INET
, &sa
, src_str
,
242 inet_ntop(AF_INET
, &da
, dst_str
,
244 inet_ntop(AF_INET
, &ra
, rsp_str
,
246 mtracep
->rsp_ttl
, ntohl(mtracep
->qry_id
));
247 if (mtrace_len
> (int)sizeof(struct igmp_mtrace
)) {
251 int responses
= mtrace_len
- sizeof(struct igmp_mtrace
);
253 if ((responses
% sizeof(struct igmp_mtrace_rsp
)) != 0)
254 if (PIM_DEBUG_MTRACE
)
256 "Mtrace response block of wrong length");
258 responses
= responses
/ sizeof(struct igmp_mtrace_rsp
);
260 for (i
= 0; i
< responses
; i
++)
261 mtrace_rsp_debug(mtracep
->qry_id
, i
, &mtracep
->rsp
[i
]);
265 /* 5.1 Query Arrival Time */
266 static uint32_t query_arrival_time(void)
271 if (gettimeofday(&tv
, NULL
) < 0) {
272 if (PIM_DEBUG_MTRACE
)
273 zlog_warn("Query arrival time lookup failed: errno=%d: %s",
274 errno
, safe_strerror(errno
));
277 /* not sure second offset correct, as I get different value */
278 qat
= ((tv
.tv_sec
+ 32384) << 16) + ((tv
.tv_usec
<< 10) / 15625);
283 static int mtrace_send_packet(struct interface
*ifp
,
284 struct igmp_mtrace
*mtracep
,
285 size_t mtrace_buf_len
, struct in_addr dst_addr
,
286 struct in_addr group_addr
)
288 struct sockaddr_in to
;
293 char if_str
[INET_ADDRSTRLEN
];
294 char rsp_str
[INET_ADDRSTRLEN
];
297 memset(&to
, 0, sizeof(to
));
298 to
.sin_family
= AF_INET
;
299 to
.sin_addr
= dst_addr
;
302 if (PIM_DEBUG_MTRACE
) {
303 struct in_addr if_addr
;
305 if_addr
= mtrace_primary_address(ifp
);
307 "Sending mtrace packet to %s on %s",
308 inet_ntop(AF_INET
, &mtracep
->rsp_addr
, rsp_str
,
310 inet_ntop(AF_INET
, &if_addr
, if_str
, sizeof(if_str
)));
313 fd
= pim_socket_raw(IPPROTO_IGMP
);
318 ret
= pim_socket_bind(fd
, ifp
);
325 if (IPV4_CLASS_DE(ntohl(dst_addr
.s_addr
))) {
326 if (IPV4_MC_LINKLOCAL(ntohl(dst_addr
.s_addr
))) {
329 if (mtracep
->type
== PIM_IGMP_MTRACE_RESPONSE
)
330 ttl
= mtracep
->rsp_ttl
;
334 ret
= setsockopt(fd
, IPPROTO_IP
, IP_MULTICAST_TTL
, &ttl
,
338 if (PIM_DEBUG_MTRACE
)
339 zlog_warn("Failed to set socket multicast TTL");
345 sent
= sendto(fd
, (char *)mtracep
, mtrace_buf_len
, MSG_DONTWAIT
,
346 (struct sockaddr
*)&to
, tolen
);
348 if (sent
!= (ssize_t
)mtrace_buf_len
) {
349 char dst_str
[INET_ADDRSTRLEN
];
350 char group_str
[INET_ADDRSTRLEN
];
352 pim_inet4_dump("<dst?>", dst_addr
, dst_str
, sizeof(dst_str
));
353 pim_inet4_dump("<group?>", group_addr
, group_str
,
356 if (PIM_DEBUG_MTRACE
)
358 "Send mtrace request failed for %s on%s: group=%s msg_size=%zd: errno=%d: %s",
359 dst_str
, ifp
->name
, group_str
,
360 mtrace_buf_len
, errno
,
361 safe_strerror(errno
));
363 if (PIM_DEBUG_MTRACE
)
365 "Send mtrace request failed for %s on %s: group=%s msg_size=%zd: sent=%zd",
366 dst_str
, ifp
->name
, group_str
,
367 mtrace_buf_len
, sent
);
378 static int mtrace_un_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
,
379 struct interface
*interface
)
381 struct pim_nexthop nexthop
;
382 struct sockaddr_in to
;
383 struct interface
*if_out
;
390 checksum
= ip_hdr
->ip_sum
;
394 if (checksum
!= in_cksum(ip_hdr
, ip_hdr
->ip_hl
* 4))
397 if (ip_hdr
->ip_ttl
-- <= 1)
400 ip_hdr
->ip_sum
= in_cksum(ip_hdr
, ip_hdr
->ip_hl
* 4);
402 fd
= pim_socket_raw(IPPROTO_RAW
);
407 pim_socket_ip_hdr(fd
);
409 if (interface
== NULL
) {
410 memset(&nexthop
, 0, sizeof(nexthop
));
411 if (!pim_nexthop_lookup(pim
, &nexthop
, ip_hdr
->ip_dst
, 0)) {
413 if (PIM_DEBUG_MTRACE
)
415 "Dropping mtrace packet, no route to destination");
419 if_out
= nexthop
.interface
;
424 ret
= pim_socket_bind(fd
, if_out
);
431 memset(&to
, 0, sizeof(to
));
432 to
.sin_family
= AF_INET
;
433 to
.sin_addr
= ip_hdr
->ip_dst
;
436 sent
= sendto(fd
, ip_hdr
, ntohs(ip_hdr
->ip_len
), 0,
437 (struct sockaddr
*)&to
, tolen
);
442 if (PIM_DEBUG_MTRACE
)
444 "Failed to forward mtrace packet: sendto errno=%d, %s",
445 errno
, safe_strerror(errno
));
449 if (PIM_DEBUG_MTRACE
) {
450 zlog_debug("Fwd mtrace packet len=%u to %s ttl=%u",
451 ntohs(ip_hdr
->ip_len
), inet_ntoa(ip_hdr
->ip_dst
),
458 static int mtrace_mc_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
)
461 struct channel_oil
*c_oil
;
462 struct listnode
*chnode
;
463 struct listnode
*chnextnode
;
464 struct pim_ifchannel
*ch
= NULL
;
467 memset(&sg
, 0, sizeof(struct prefix_sg
));
468 sg
.grp
= ip_hdr
->ip_dst
;
470 c_oil
= pim_find_channel_oil(pim
, &sg
);
473 if (PIM_DEBUG_MTRACE
) {
475 "Dropping mtrace multicast packet len=%u to %s ttl=%u",
476 ntohs(ip_hdr
->ip_len
),
477 inet_ntoa(ip_hdr
->ip_dst
), ip_hdr
->ip_ttl
);
481 if (c_oil
->up
== NULL
)
483 if (c_oil
->up
->ifchannels
== NULL
)
485 for (ALL_LIST_ELEMENTS(c_oil
->up
->ifchannels
, chnode
, chnextnode
, ch
)) {
486 if (pim_macro_chisin_oiflist(ch
)) {
489 r
= mtrace_un_forward_packet(pim
, ip_hdr
,
499 static int mtrace_forward_packet(struct pim_instance
*pim
, struct ip
*ip_hdr
)
501 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
)))
502 return mtrace_mc_forward_packet(pim
, ip_hdr
);
504 return mtrace_un_forward_packet(pim
, ip_hdr
, NULL
);
507 static int mtrace_send_mc_response(struct pim_instance
*pim
,
508 struct igmp_mtrace
*mtracep
,
512 struct channel_oil
*c_oil
;
513 struct listnode
*chnode
;
514 struct listnode
*chnextnode
;
515 struct pim_ifchannel
*ch
= NULL
;
518 memset(&sg
, 0, sizeof(struct prefix_sg
));
519 sg
.grp
= mtracep
->rsp_addr
;
521 c_oil
= pim_find_channel_oil(pim
, &sg
);
524 if (PIM_DEBUG_MTRACE
) {
526 "Dropping mtrace multicast response packet len=%u to %s",
527 (unsigned int)mtrace_len
,
528 inet_ntoa(mtracep
->rsp_addr
));
532 if (c_oil
->up
== NULL
)
534 if (c_oil
->up
->ifchannels
== NULL
)
536 for (ALL_LIST_ELEMENTS(c_oil
->up
->ifchannels
, chnode
, chnextnode
, ch
)) {
537 if (pim_macro_chisin_oiflist(ch
)) {
540 r
= mtrace_send_packet(ch
->interface
, mtracep
,
541 mtrace_len
, mtracep
->rsp_addr
,
550 /* 6.5 Sending Traceroute Responses */
551 static int mtrace_send_response(struct pim_instance
*pim
,
552 struct igmp_mtrace
*mtracep
, size_t mtrace_len
)
554 struct pim_nexthop nexthop
;
556 mtracep
->type
= PIM_IGMP_MTRACE_RESPONSE
;
558 mtracep
->checksum
= 0;
559 mtracep
->checksum
= in_cksum((char *)mtracep
, mtrace_len
);
561 if (IPV4_CLASS_DE(ntohl(mtracep
->rsp_addr
.s_addr
))) {
562 struct pim_rpf
*p_rpf
;
563 char grp_str
[INET_ADDRSTRLEN
];
565 if (pim_rp_i_am_rp(pim
, mtracep
->rsp_addr
))
566 return mtrace_send_mc_response(pim
, mtracep
,
569 p_rpf
= pim_rp_g(pim
, mtracep
->rsp_addr
);
572 if (PIM_DEBUG_MTRACE
)
573 zlog_warn("mtrace no RP for %s",
575 &(mtracep
->rsp_addr
),
576 grp_str
, sizeof(grp_str
)));
579 nexthop
= p_rpf
->source_nexthop
;
580 if (PIM_DEBUG_MTRACE
)
581 zlog_debug("mtrace response to RP");
583 memset(&nexthop
, 0, sizeof(nexthop
));
584 /* TODO: should use unicast rib lookup */
585 if (!pim_nexthop_lookup(pim
, &nexthop
, mtracep
->rsp_addr
, 1)) {
586 if (PIM_DEBUG_MTRACE
)
588 "Dropped response qid=%ud, no route to response address",
594 return mtrace_send_packet(nexthop
.interface
, mtracep
, mtrace_len
,
595 mtracep
->rsp_addr
, mtracep
->grp_addr
);
598 int igmp_mtrace_recv_qry_req(struct igmp_sock
*igmp
, struct ip
*ip_hdr
,
599 struct in_addr from
, const char *from_str
,
600 char *igmp_msg
, int igmp_msg_len
)
602 static uint32_t qry_id
, qry_src
;
603 char mtrace_buf
[MTRACE_HDR_SIZE
+ MTRACE_MAX_HOPS
* MTRACE_RSP_SIZE
];
604 struct interface
*ifp
;
605 struct interface
*out_ifp
= NULL
;
606 struct pim_interface
*pim_ifp
;
607 struct pim_instance
*pim
;
608 struct igmp_mtrace
*mtracep
;
609 struct igmp_mtrace_rsp
*rspp
;
610 struct in_addr nh_addr
;
611 enum mtrace_fwd_code fwd_code
= MTRACE_FWD_CODE_NO_ERROR
;
613 int last_rsp_ind
= 0;
615 uint16_t recv_checksum
;
620 ifp
= igmp
->interface
;
625 * 6. Router Behaviour
626 * Check if mtrace packet is addressed elsewhere and forward,
629 if (!IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
)))
630 if (!if_lookup_exact_address(&ip_hdr
->ip_dst
, AF_INET
,
632 return mtrace_forward_packet(pim
, ip_hdr
);
634 if (igmp_msg_len
< (int)sizeof(struct igmp_mtrace
)) {
635 if (PIM_DEBUG_MTRACE
)
637 "Recv mtrace packet from %s on %s: too short, len=%d, min=%zu",
638 from_str
, ifp
->name
, igmp_msg_len
,
639 sizeof(struct igmp_mtrace
));
643 mtracep
= (struct igmp_mtrace
*)igmp_msg
;
645 recv_checksum
= mtracep
->checksum
;
647 mtracep
->checksum
= 0;
649 checksum
= in_cksum(igmp_msg
, igmp_msg_len
);
651 if (recv_checksum
!= checksum
) {
652 if (PIM_DEBUG_MTRACE
)
654 "Recv mtrace packet from %s on %s: checksum mismatch: received=%x computed=%x",
655 from_str
, ifp
->name
, recv_checksum
, checksum
);
659 /* Collecting IGMP Rx stats */
660 igmp
->rx_stats
.mtrace_req
++;
662 if (PIM_DEBUG_MTRACE
)
663 mtrace_debug(pim_ifp
, mtracep
, igmp_msg_len
);
665 /* subtract header from message length */
666 r_len
= igmp_msg_len
- sizeof(struct igmp_mtrace
);
668 /* Classify mtrace packet, check if it is a query */
670 if (PIM_DEBUG_MTRACE
)
671 zlog_debug("Received IGMP multicast traceroute query");
673 /* 6.1.1 Packet verification */
674 if (!pim_if_connected_to_source(ifp
, mtracep
->dst_addr
)) {
675 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
))) {
676 if (PIM_DEBUG_MTRACE
)
678 "Dropping multicast query on wrong interface");
681 /* Unicast query on wrong interface */
682 fwd_code
= MTRACE_FWD_CODE_WRONG_IF
;
683 if (PIM_DEBUG_MTRACE
)
684 zlog_debug("Multicast query on wrong interface");
686 if (qry_id
== mtracep
->qry_id
&& qry_src
== from
.s_addr
) {
687 if (PIM_DEBUG_MTRACE
)
689 "Dropping multicast query with duplicate source and id");
692 qry_id
= mtracep
->qry_id
;
693 qry_src
= from
.s_addr
;
695 /* if response fields length is equal to a whole number of responses */
696 else if ((r_len
% sizeof(struct igmp_mtrace_rsp
)) == 0) {
697 r_len
= igmp_msg_len
- sizeof(struct igmp_mtrace
);
700 last_rsp_ind
= r_len
/ sizeof(struct igmp_mtrace_rsp
);
701 if (last_rsp_ind
> MTRACE_MAX_HOPS
) {
702 if (PIM_DEBUG_MTRACE
)
703 zlog_warn("Mtrace request of excessive size");
707 if (PIM_DEBUG_MTRACE
)
709 "Recv mtrace packet from %s on %s: invalid length %d",
710 from_str
, ifp
->name
, igmp_msg_len
);
714 /* 6.2.1 Packet Verification - drop not link-local multicast */
715 if (IPV4_CLASS_DE(ntohl(ip_hdr
->ip_dst
.s_addr
))
716 && !IPV4_MC_LINKLOCAL(ntohl(ip_hdr
->ip_dst
.s_addr
))) {
717 if (PIM_DEBUG_MTRACE
)
719 "Recv mtrace packet from %s on %s: not link-local multicast %s",
720 from_str
, ifp
->name
, inet_ntoa(ip_hdr
->ip_dst
));
724 /* 6.2.2. Normal Processing */
726 /* 6.2.2. 1. If there is room in the current buffer? */
728 if (last_rsp_ind
== MTRACE_MAX_HOPS
) {
729 /* ...there was no room... */
730 mtracep
->rsp
[MTRACE_MAX_HOPS
- 1].fwd_code
=
731 MTRACE_FWD_CODE_NO_SPACE
;
732 return mtrace_send_response(pim_ifp
->pim
, mtracep
,
736 /* ...insert new response block... */
738 /* calculate new mtrace lenght with extra response */
739 mtrace_len
= igmp_msg_len
+ sizeof(struct igmp_mtrace_rsp
);
741 /* copy received query/request */
742 memcpy(mtrace_buf
, igmp_msg
, igmp_msg_len
);
744 /* repoint mtracep pointer to copy */
745 mtracep
= (struct igmp_mtrace
*)mtrace_buf
;
747 /* pointer for extra response field to be filled in */
748 rspp
= &mtracep
->rsp
[last_rsp_ind
];
750 /* initialize extra response field */
751 mtrace_rsp_init(rspp
);
753 /* carry over any error noted when receiving the query */
754 rspp
->fwd_code
= fwd_code
;
756 /* ...and fill in Query Arrival Time... */
757 rspp
->arrival
= htonl(query_arrival_time());
758 rspp
->outgoing
= pim_ifp
->primary_address
;
759 rspp
->out_count
= htonl(MTRACE_UNKNOWN_COUNT
);
762 /* 6.2.2. 2. Attempt to determine the forwarding information... */
764 if (mtracep
->grp_addr
.s_addr
!= INADDR_ANY
)
765 fwd_info
= mtrace_fwd_info(pim
, mtracep
, rspp
, &out_ifp
);
767 fwd_info
= mtrace_fwd_info_weak(pim
, mtracep
, rspp
, &out_ifp
);
769 /* 6.2.2 3. If no forwarding information... */
771 if (PIM_DEBUG_MTRACE
)
772 zlog_debug("mtrace not found multicast state");
773 mtrace_rsp_set_fwd_code(rspp
, MTRACE_FWD_CODE_NO_ROUTE
);
774 /* 6.2.2. 3. forward the packet to requester */
775 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
778 nh_addr
= rspp
->prev_hop
;
780 reached_source
= false;
782 if (nh_addr
.s_addr
== INADDR_ANY
) {
783 /* no pim? i.e. 7.5.3. No Previous Hop */
784 if (!out_ifp
->info
) {
785 if (PIM_DEBUG_MTRACE
)
786 zlog_debug("mtrace not found incoming if w/ pim");
787 mtrace_rsp_set_fwd_code(rspp
,
788 MTRACE_FWD_CODE_NO_MULTICAST
);
789 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
791 /* reached source? i.e. 7.5.1 Arriving at source */
792 if (pim_if_connected_to_source(out_ifp
, mtracep
->src_addr
)) {
793 reached_source
= true;
794 rspp
->prev_hop
= mtracep
->src_addr
;
797 * 6.4 Forwarding Traceroute Requests:
798 * Previous-hop router not known,
799 * packet is sent to an appropriate multicast address
801 (void)inet_aton(MCAST_ALL_ROUTERS
, &nh_addr
);
804 /* 6.2.2 8. If this router is the Rendez-vous Point */
805 if (pim_rp_i_am_rp(pim
, mtracep
->grp_addr
)) {
806 mtrace_rsp_set_fwd_code(rspp
, MTRACE_FWD_CODE_REACHED_RP
);
807 /* 7.7.1. PIM-SM ...RP has not performed source-specific join */
808 if (rspp
->src_mask
== MTRACE_SRC_MASK_GROUP
)
809 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
813 * 6.4 Forwarding Traceroute Requests: the number of response
814 * blocks exceeds number of responses, so forward to the requester.
816 if (mtracep
->hops
<= (last_rsp_ind
+ 1))
817 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
819 /* 7.5.1. Arriving at source: terminate trace */
821 return mtrace_send_response(pim
, mtracep
, mtrace_len
);
823 mtracep
->checksum
= 0;
825 mtracep
->checksum
= in_cksum(mtrace_buf
, mtrace_len
);
827 /* 6.4 Forwarding Traceroute Requests: response blocks less than req. */
828 return mtrace_send_packet(out_ifp
, mtracep
, mtrace_len
, nh_addr
,
832 /* 6.3. Traceroute responses */
833 int igmp_mtrace_recv_response(struct igmp_sock
*igmp
, struct ip
*ip_hdr
,
834 struct in_addr from
, const char *from_str
,
835 char *igmp_msg
, int igmp_msg_len
)
837 static uint32_t qry_id
, rsp_dst
;
838 struct interface
*ifp
;
839 struct pim_interface
*pim_ifp
;
840 struct pim_instance
*pim
;
841 struct igmp_mtrace
*mtracep
;
842 uint16_t recv_checksum
;
845 ifp
= igmp
->interface
;
849 if (igmp_msg_len
< (int)sizeof(struct igmp_mtrace
)) {
850 if (PIM_DEBUG_MTRACE
)
852 "Recv mtrace packet from %s on %s: too short, len=%d, min=%zu",
853 from_str
, ifp
->name
, igmp_msg_len
,
854 sizeof(struct igmp_mtrace
));
858 mtracep
= (struct igmp_mtrace
*)igmp_msg
;
860 recv_checksum
= mtracep
->checksum
;
862 mtracep
->checksum
= 0;
864 checksum
= in_cksum(igmp_msg
, igmp_msg_len
);
866 if (recv_checksum
!= checksum
) {
867 if (PIM_DEBUG_MTRACE
)
869 "Recv mtrace response from %s on %s: checksum mismatch: received=%x computed=%x",
870 from_str
, ifp
->name
, recv_checksum
, checksum
);
874 mtracep
->checksum
= checksum
;
876 /* Collecting IGMP Rx stats */
877 igmp
->rx_stats
.mtrace_rsp
++;
879 if (PIM_DEBUG_MTRACE
)
880 mtrace_debug(pim_ifp
, mtracep
, igmp_msg_len
);
882 /* Drop duplicate packets */
883 if (qry_id
== mtracep
->qry_id
&& rsp_dst
== ip_hdr
->ip_dst
.s_addr
) {
884 if (PIM_DEBUG_MTRACE
)
885 zlog_debug("duplicate mtrace response packet dropped");
889 qry_id
= mtracep
->qry_id
;
890 rsp_dst
= ip_hdr
->ip_dst
.s_addr
;
892 return mtrace_forward_packet(pim
, ip_hdr
);