1 /*
2  * Copyright (c) 1995, 1996
3  *        The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  */
21 
22 #include <sys/cdefs.h>
23 #ifndef lint
24 __RCSID("$NetBSD: print-pim.c,v 1.12 2024/09/02 16:15:32 christos Exp $");
25 #endif
26 
27 /* \summary: Protocol Independent Multicast (PIM) printer */
28 
29 #include <config.h>
30 
31 #include "netdissect-stdinc.h"
32 
33 #include "netdissect.h"
34 #include "addrtoname.h"
35 #include "extract.h"
36 
37 #include "ip.h"
38 #include "ip6.h"
39 #include "ipproto.h"
40 
41 #define PIMV1_TYPE_QUERY           0
42 #define PIMV1_TYPE_REGISTER        1
43 #define PIMV1_TYPE_REGISTER_STOP   2
44 #define PIMV1_TYPE_JOIN_PRUNE      3
45 #define PIMV1_TYPE_RP_REACHABILITY 4
46 #define PIMV1_TYPE_ASSERT          5
47 #define PIMV1_TYPE_GRAFT           6
48 #define PIMV1_TYPE_GRAFT_ACK       7
49 
50 static const struct tok pimv1_type_str[] = {
51           { PIMV1_TYPE_QUERY,           "Query"         },
52           { PIMV1_TYPE_REGISTER,        "Register"      },
53           { PIMV1_TYPE_REGISTER_STOP,   "Register-Stop" },
54           { PIMV1_TYPE_JOIN_PRUNE,      "Join/Prune"    },
55           { PIMV1_TYPE_RP_REACHABILITY, "RP-reachable"  },
56           { PIMV1_TYPE_ASSERT,          "Assert"        },
57           { PIMV1_TYPE_GRAFT,           "Graft"         },
58           { PIMV1_TYPE_GRAFT_ACK,       "Graft-ACK"     },
59           { 0, NULL }
60 };
61 
62 #define PIMV2_TYPE_HELLO         0
63 #define PIMV2_TYPE_REGISTER      1
64 #define PIMV2_TYPE_REGISTER_STOP 2
65 #define PIMV2_TYPE_JOIN_PRUNE    3
66 #define PIMV2_TYPE_BOOTSTRAP     4
67 #define PIMV2_TYPE_ASSERT        5
68 #define PIMV2_TYPE_GRAFT         6
69 #define PIMV2_TYPE_GRAFT_ACK     7
70 #define PIMV2_TYPE_CANDIDATE_RP  8
71 #define PIMV2_TYPE_PRUNE_REFRESH 9
72 #define PIMV2_TYPE_DF_ELECTION   10
73 #define PIMV2_TYPE_ECMP_REDIRECT 11
74 
75 static const struct tok pimv2_type_values[] = {
76     { PIMV2_TYPE_HELLO,         "Hello" },
77     { PIMV2_TYPE_REGISTER,      "Register" },
78     { PIMV2_TYPE_REGISTER_STOP, "Register Stop" },
79     { PIMV2_TYPE_JOIN_PRUNE,    "Join / Prune" },
80     { PIMV2_TYPE_BOOTSTRAP,     "Bootstrap" },
81     { PIMV2_TYPE_ASSERT,        "Assert" },
82     { PIMV2_TYPE_GRAFT,         "Graft" },
83     { PIMV2_TYPE_GRAFT_ACK,     "Graft Acknowledgement" },
84     { PIMV2_TYPE_CANDIDATE_RP,  "Candidate RP Advertisement" },
85     { PIMV2_TYPE_PRUNE_REFRESH, "Prune Refresh" },
86     { PIMV2_TYPE_DF_ELECTION,   "DF Election" },
87     { PIMV2_TYPE_ECMP_REDIRECT, "ECMP Redirect" },
88     { 0, NULL}
89 };
90 
91 #define PIMV2_HELLO_OPTION_HOLDTIME             1
92 #define PIMV2_HELLO_OPTION_LANPRUNEDELAY        2
93 #define PIMV2_HELLO_OPTION_DR_PRIORITY_OLD     18
94 #define PIMV2_HELLO_OPTION_DR_PRIORITY         19
95 #define PIMV2_HELLO_OPTION_GENID               20
96 #define PIMV2_HELLO_OPTION_REFRESH_CAP         21
97 #define PIMV2_HELLO_OPTION_BIDIR_CAP           22
98 #define PIMV2_HELLO_OPTION_ADDRESS_LIST        24
99 #define PIMV2_HELLO_OPTION_ADDRESS_LIST_OLD 65001
100 
101 static const struct tok pimv2_hello_option_values[] = {
102     { PIMV2_HELLO_OPTION_HOLDTIME,         "Hold Time" },
103     { PIMV2_HELLO_OPTION_LANPRUNEDELAY,    "LAN Prune Delay" },
104     { PIMV2_HELLO_OPTION_DR_PRIORITY_OLD,  "DR Priority (Old)" },
105     { PIMV2_HELLO_OPTION_DR_PRIORITY,      "DR Priority" },
106     { PIMV2_HELLO_OPTION_GENID,            "Generation ID" },
107     { PIMV2_HELLO_OPTION_REFRESH_CAP,      "State Refresh Capability" },
108     { PIMV2_HELLO_OPTION_BIDIR_CAP,        "Bi-Directional Capability" },
109     { PIMV2_HELLO_OPTION_ADDRESS_LIST,     "Address List" },
110     { PIMV2_HELLO_OPTION_ADDRESS_LIST_OLD, "Address List (Old)" },
111     { 0, NULL}
112 };
113 
114 #define PIMV2_REGISTER_FLAG_LEN      4
115 #define PIMV2_REGISTER_FLAG_BORDER 0x80000000
116 #define PIMV2_REGISTER_FLAG_NULL   0x40000000
117 
118 static const struct tok pimv2_register_flag_values[] = {
119     { PIMV2_REGISTER_FLAG_BORDER, "Border" },
120     { PIMV2_REGISTER_FLAG_NULL, "Null" },
121     { 0, NULL}
122 };
123 
124 #define PIMV2_DF_ELECTION_OFFER                  1
125 #define PIMV2_DF_ELECTION_WINNER                 2
126 #define PIMV2_DF_ELECTION_BACKOFF                3
127 #define PIMV2_DF_ELECTION_PASS                   4
128 
129 static const struct tok pimv2_df_election_flag_values[] = {
130     { PIMV2_DF_ELECTION_OFFER, "Offer" },
131     { PIMV2_DF_ELECTION_WINNER, "Winner" },
132     { PIMV2_DF_ELECTION_BACKOFF, "Backoff" },
133     { PIMV2_DF_ELECTION_PASS, "Pass" },
134     { 0, NULL}
135 };
136 
137 #define PIMV2_DF_ELECTION_PASS_BACKOFF_STR(x)   ( \
138       x == PIMV2_DF_ELECTION_BACKOFF ? "offer" : "new winner" )
139 
140 
141 /*
142  * XXX: We consider a case where IPv6 is not ready yet for portability,
143  * but PIM dependent definitions should be independent of IPv6...
144  */
145 
146 struct pim {
147           nd_uint8_t          pim_typever;
148                               /* upper 4bit: PIM version number; 2 for PIMv2 */
149                               /* lower 4bit: the PIM message type, currently they are:
150                                * Hello, Register, Register-Stop, Join/Prune,
151                                * Bootstrap, Assert, Graft (PIM-DM only),
152                                * Graft-Ack (PIM-DM only), C-RP-Adv
153                                */
154 #define PIM_VER(x)  (((x) & 0xf0) >> 4)
155 #define PIM_TYPE(x) ((x) & 0x0f)
156           nd_uint8_t          pim_rsv;  /* Reserved in v1, subtype+address length in v2 */
157 #define PIM_SUBTYPE(x)  (((x) & 0xf0) >> 4)
158           nd_uint16_t         pim_cksum;          /* IP style check sum */
159 };
160 
161 static void pimv2_print(netdissect_options *, const u_char *bp, u_int len, const u_char *);
162 
163 static void
pimv1_join_prune_print(netdissect_options * ndo,const u_char * bp,u_int len)164 pimv1_join_prune_print(netdissect_options *ndo,
165                        const u_char *bp, u_int len)
166 {
167           u_int ngroups, njoin, nprune;
168           u_int njp;
169 
170           /* If it's a single group and a single source, use 1-line output. */
171           if (ND_TTEST_LEN(bp, 30) && GET_U_1(bp + 11) == 1 &&
172               ((njoin = GET_BE_U_2(bp + 20)) + GET_BE_U_2(bp + 22)) == 1) {
173                     u_int hold;
174 
175                     ND_PRINT(" RPF %s ", GET_IPADDR_STRING(bp));
176                     hold = GET_BE_U_2(bp + 6);
177                     if (hold != 180) {
178                               ND_PRINT("Hold ");
179                               unsigned_relts_print(ndo, hold);
180                     }
181                     ND_PRINT("%s (%s/%u, %s", njoin ? "Join" : "Prune",
182                     GET_IPADDR_STRING(bp + 26), GET_U_1(bp + 25) & 0x3f,
183                     GET_IPADDR_STRING(bp + 12));
184                     if (GET_BE_U_4(bp + 16) != 0xffffffff)
185                               ND_PRINT("/%s", GET_IPADDR_STRING(bp + 16));
186                     ND_PRINT(") %s%s %s",
187                         (GET_U_1(bp + 24) & 0x01) ? "Sparse" : "Dense",
188                         (GET_U_1(bp + 25) & 0x80) ? " WC" : "",
189                         (GET_U_1(bp + 25) & 0x40) ? "RP" : "SPT");
190                     return;
191           }
192 
193           if (len < sizeof(nd_ipv4))
194                     goto trunc;
195           if (ndo->ndo_vflag > 1)
196                     ND_PRINT("\n");
197           ND_PRINT(" Upstream Nbr: %s", GET_IPADDR_STRING(bp));
198           bp += 4;
199           len -= 4;
200           if (len < 4)
201                     goto trunc;
202           if (ndo->ndo_vflag > 1)
203                     ND_PRINT("\n");
204           ND_PRINT(" Hold time: ");
205           unsigned_relts_print(ndo, GET_BE_U_2(bp + 2));
206           if (ndo->ndo_vflag < 2)
207                     return;
208           bp += 4;
209           len -= 4;
210 
211           if (len < 4)
212                     goto trunc;
213           ngroups = GET_U_1(bp + 3);
214           bp += 4;
215           len -= 4;
216           while (ngroups != 0) {
217                     /*
218                      * XXX - does the address have length "addrlen" and the
219                      * mask length "maddrlen"?
220                      */
221                     if (len < 4)
222                               goto trunc;
223                     ND_PRINT("\n\tGroup: %s", GET_IPADDR_STRING(bp));
224                     bp += 4;
225                     len -= 4;
226                     if (len < 4)
227                               goto trunc;
228                     if (GET_BE_U_4(bp) != 0xffffffff)
229                               ND_PRINT("/%s", GET_IPADDR_STRING(bp));
230                     bp += 4;
231                     len -= 4;
232                     if (len < 4)
233                               goto trunc;
234                     njoin = GET_BE_U_2(bp);
235                     nprune = GET_BE_U_2(bp + 2);
236                     ND_PRINT(" joined: %u pruned: %u", njoin, nprune);
237                     bp += 4;
238                     len -= 4;
239                     for (njp = 0; njp < (njoin + nprune); njp++) {
240                               const char *type;
241 
242                               if (njp < njoin)
243                                         type = "Join ";
244                               else
245                                         type = "Prune";
246                               if (len < 6)
247                                         goto trunc;
248                               ND_PRINT("\n\t%s %s%s%s%s/%u", type,
249                                   (GET_U_1(bp) & 0x01) ? "Sparse " : "Dense ",
250                                   (GET_U_1(bp + 1) & 0x80) ? "WC " : "",
251                                   (GET_U_1(bp + 1) & 0x40) ? "RP " : "SPT ",
252                                   GET_IPADDR_STRING(bp + 2),
253                                   GET_U_1(bp + 1) & 0x3f);
254                               bp += 6;
255                               len -= 6;
256                     }
257                     ngroups--;
258           }
259           return;
260 trunc:
261           nd_print_trunc(ndo);
262 }
263 
264 void
pimv1_print(netdissect_options * ndo,const u_char * bp,u_int len)265 pimv1_print(netdissect_options *ndo,
266             const u_char *bp, u_int len)
267 {
268           u_char type;
269 
270           ndo->ndo_protocol = "pimv1";
271           type = GET_U_1(bp + 1);
272 
273           ND_PRINT(" %s", tok2str(pimv1_type_str, "[type %u]", type));
274           switch (type) {
275           case PIMV1_TYPE_QUERY:
276                     if (ND_TTEST_1(bp + 8)) {
277                               switch (GET_U_1(bp + 8) >> 4) {
278                               case 0:
279                                         ND_PRINT(" Dense-mode");
280                                         break;
281                               case 1:
282                                         ND_PRINT(" Sparse-mode");
283                                         break;
284                               case 2:
285                                         ND_PRINT(" Sparse-Dense-mode");
286                                         break;
287                               default:
288                                         ND_PRINT(" mode-%u", GET_U_1(bp + 8) >> 4);
289                                         break;
290                               }
291                     }
292                     if (ndo->ndo_vflag) {
293                               ND_PRINT(" (Hold-time ");
294                               unsigned_relts_print(ndo, GET_BE_U_2(bp + 10));
295                               ND_PRINT(")");
296                     }
297                     break;
298 
299           case PIMV1_TYPE_REGISTER:
300                     ND_TCHECK_LEN(bp + 8, 20);                        /* ip header */
301                     ND_PRINT(" for %s > %s", GET_IPADDR_STRING(bp + 20),
302                                 GET_IPADDR_STRING(bp + 24));
303                     break;
304           case PIMV1_TYPE_REGISTER_STOP:
305                     ND_PRINT(" for %s > %s", GET_IPADDR_STRING(bp + 8),
306                                 GET_IPADDR_STRING(bp + 12));
307                     break;
308           case PIMV1_TYPE_RP_REACHABILITY:
309                     if (ndo->ndo_vflag) {
310                               ND_PRINT(" group %s", GET_IPADDR_STRING(bp + 8));
311                               if (GET_BE_U_4(bp + 12) != 0xffffffff)
312                                         ND_PRINT("/%s", GET_IPADDR_STRING(bp + 12));
313                               ND_PRINT(" RP %s hold ", GET_IPADDR_STRING(bp + 16));
314                               unsigned_relts_print(ndo, GET_BE_U_2(bp + 22));
315                     }
316                     break;
317           case PIMV1_TYPE_ASSERT:
318                     ND_PRINT(" for %s > %s", GET_IPADDR_STRING(bp + 16),
319                                 GET_IPADDR_STRING(bp + 8));
320                     if (GET_BE_U_4(bp + 12) != 0xffffffff)
321                               ND_PRINT("/%s", GET_IPADDR_STRING(bp + 12));
322                     ND_PRINT(" %s pref %u metric %u",
323                         (GET_U_1(bp + 20) & 0x80) ? "RP-tree" : "SPT",
324                         GET_BE_U_4(bp + 20) & 0x7fffffff,
325                         GET_BE_U_4(bp + 24));
326                     break;
327           case PIMV1_TYPE_JOIN_PRUNE:
328           case PIMV1_TYPE_GRAFT:
329           case PIMV1_TYPE_GRAFT_ACK:
330                     if (ndo->ndo_vflag) {
331                               if (len < 8)
332                                         goto trunc;
333                               pimv1_join_prune_print(ndo, bp + 8, len - 8);
334                     }
335                     break;
336           }
337           if ((GET_U_1(bp + 4) >> 4) != 1)
338                     ND_PRINT(" [v%u]", GET_U_1(bp + 4) >> 4);
339           return;
340 
341 trunc:
342           nd_print_trunc(ndo);
343 }
344 
345 /*
346  * auto-RP is a cisco protocol, documented at
347  * ftp://ftpeng.cisco.com/ipmulticast/specs/pim-autorp-spec01.txt
348  *
349  * This implements version 1+, dated Sept 9, 1998.
350  */
351 void
cisco_autorp_print(netdissect_options * ndo,const u_char * bp,u_int len)352 cisco_autorp_print(netdissect_options *ndo,
353                    const u_char *bp, u_int len)
354 {
355           u_int type;
356           u_int numrps;
357           u_int hold;
358 
359           ndo->ndo_protocol = "cisco_autorp";
360           if (len < 8)
361                     goto trunc;
362           ND_PRINT(" auto-rp ");
363           type = GET_U_1(bp);
364           switch (type) {
365           case 0x11:
366                     ND_PRINT("candidate-advert");
367                     break;
368           case 0x12:
369                     ND_PRINT("mapping");
370                     break;
371           default:
372                     ND_PRINT("type-0x%02x", type);
373                     break;
374           }
375 
376           numrps = GET_U_1(bp + 1);
377 
378           ND_PRINT(" Hold ");
379           hold = GET_BE_U_2(bp + 2);
380           if (hold)
381                     unsigned_relts_print(ndo, GET_BE_U_2(bp + 2));
382           else
383                     ND_PRINT("FOREVER");
384 
385           /* Next 4 bytes are reserved. */
386 
387           bp += 8; len -= 8;
388 
389           /*XXX skip unless -v? */
390 
391           /*
392            * Rest of packet:
393            * numrps entries of the form:
394            * 32 bits: RP
395            * 6 bits: reserved
396            * 2 bits: PIM version supported, bit 0 is "supports v1", 1 is "v2".
397            * 8 bits: # of entries for this RP
398            * each entry: 7 bits: reserved, 1 bit: negative,
399            *               8 bits: mask 32 bits: source
400            * lather, rinse, repeat.
401            */
402           while (numrps != 0) {
403                     u_int nentries;
404                     char s;
405 
406                     if (len < 4)
407                               goto trunc;
408                     ND_PRINT(" RP %s", GET_IPADDR_STRING(bp));
409                     bp += 4;
410                     len -= 4;
411                     if (len < 1)
412                               goto trunc;
413                     switch (GET_U_1(bp) & 0x3) {
414                     case 0: ND_PRINT(" PIMv?");
415                               break;
416                     case 1:   ND_PRINT(" PIMv1");
417                               break;
418                     case 2:   ND_PRINT(" PIMv2");
419                               break;
420                     case 3:   ND_PRINT(" PIMv1+2");
421                               break;
422                     }
423                     if (GET_U_1(bp) & 0xfc)
424                               ND_PRINT(" [rsvd=0x%02x]", GET_U_1(bp) & 0xfc);
425                     bp += 1;
426                     len -= 1;
427                     if (len < 1)
428                               goto trunc;
429                     nentries = GET_U_1(bp);
430                     bp += 1;
431                     len -= 1;
432                     s = ' ';
433                     while (nentries != 0) {
434                               if (len < 6)
435                                         goto trunc;
436                               ND_PRINT("%c%s%s/%u", s, GET_U_1(bp) & 1 ? "!" : "",
437                                         GET_IPADDR_STRING(bp + 2), GET_U_1(bp + 1));
438                               if (GET_U_1(bp) & 0x02) {
439                                         ND_PRINT(" bidir");
440                               }
441                               if (GET_U_1(bp) & 0xfc) {
442                                         ND_PRINT("[rsvd=0x%02x]", GET_U_1(bp) & 0xfc);
443                               }
444                               s = ',';
445                               bp += 6; len -= 6;
446                               nentries--;
447                     }
448                     numrps--;
449           }
450           return;
451 
452 trunc:
453           nd_print_trunc(ndo);
454 }
455 
456 void
pim_print(netdissect_options * ndo,const u_char * bp,u_int len,const u_char * bp2)457 pim_print(netdissect_options *ndo,
458           const u_char *bp, u_int len, const u_char *bp2)
459 {
460           const struct pim *pim = (const struct pim *)bp;
461           uint8_t pim_typever;
462 
463           ndo->ndo_protocol = "pim";
464 
465           pim_typever = GET_U_1(pim->pim_typever);
466           switch (PIM_VER(pim_typever)) {
467           case 2:
468                     if (!ndo->ndo_vflag) {
469                               ND_PRINT("PIMv%u, %s, length %u",
470                                         PIM_VER(pim_typever),
471                                         tok2str(pimv2_type_values,"Unknown Type",PIM_TYPE(pim_typever)),
472                                         len);
473                               return;
474                     } else {
475                               ND_PRINT("PIMv%u, length %u\n\t%s",
476                                         PIM_VER(pim_typever),
477                                         len,
478                                         tok2str(pimv2_type_values,"Unknown Type",PIM_TYPE(pim_typever)));
479                               pimv2_print(ndo, bp, len, bp2);
480                     }
481                     break;
482           default:
483                     ND_PRINT("PIMv%u, length %u",
484                               PIM_VER(pim_typever),
485                               len);
486                     break;
487           }
488 }
489 
490 /*
491  * PIMv2 uses encoded address representations.
492  *
493  * The last PIM-SM I-D before RFC2117 was published specified the
494  * following representation for unicast addresses.  However, RFC2117
495  * specified no encoding for unicast addresses with the unicast
496  * address length specified in the header.  Therefore, we have to
497  * guess which encoding is being used (Cisco's PIMv2 implementation
498  * uses the non-RFC encoding).  RFC2117 turns a previously "Reserved"
499  * field into a 'unicast-address-length-in-bytes' field.  We guess
500  * that it's the draft encoding if this reserved field is zero.
501  *
502  * RFC2362 goes back to the encoded format, and calls the addr length
503  * field "reserved" again.
504  *
505  * The first byte is the address family, from:
506  *
507  *    0    Reserved
508  *    1    IP (IP version 4)
509  *    2    IP6 (IP version 6)
510  *    3    NSAP
511  *    4    HDLC (8-bit multidrop)
512  *    5    BBN 1822
513  *    6    802 (includes all 802 media plus Ethernet "canonical format")
514  *    7    E.163
515  *    8    E.164 (SMDS, Frame Relay, ATM)
516  *    9    F.69 (Telex)
517  *   10    X.121 (X.25, Frame Relay)
518  *   11    IPX
519  *   12    Appletalk
520  *   13    Decnet IV
521  *   14    Banyan Vines
522  *   15    E.164 with NSAP format subaddress
523  *
524  * In addition, the second byte is an "Encoding".  0 is the default
525  * encoding for the address family, and no other encodings are currently
526  * specified.
527  *
528  */
529 
530 enum pimv2_addrtype {
531           pimv2_unicast, pimv2_group, pimv2_source
532 };
533 
534 /*  0                   1                   2                   3
535  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
536  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
537  * | Addr Family   | Encoding Type |     Unicast Address           |
538  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+++++++
539  *  0                   1                   2                   3
540  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
541  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
542  * | Addr Family   | Encoding Type |   Reserved    |  Mask Len     |
543  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544  * |                Group multicast Address                        |
545  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546  *  0                   1                   2                   3
547  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
548  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
549  * | Addr Family   | Encoding Type | Rsrvd   |S|W|R|  Mask Len     |
550  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
551  * |                        Source Address                         |
552  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
553  */
554 static int
pimv2_addr_print(netdissect_options * ndo,const u_char * bp,u_int len,enum pimv2_addrtype at,u_int addr_len,int silent)555 pimv2_addr_print(netdissect_options *ndo,
556                  const u_char *bp, u_int len, enum pimv2_addrtype at,
557                  u_int addr_len, int silent)
558 {
559           u_int af;
560           int hdrlen;
561 
562           if (addr_len == 0) {
563                     if (len < 2)
564                               goto trunc;
565                     switch (GET_U_1(bp)) {
566                     case 1:
567                               af = AF_INET;
568                               addr_len = (u_int)sizeof(nd_ipv4);
569                               break;
570                     case 2:
571                               af = AF_INET6;
572                               addr_len = (u_int)sizeof(nd_ipv6);
573                               break;
574                     default:
575                               return -1;
576                     }
577                     if (GET_U_1(bp + 1) != 0)
578                               return -1;
579                     hdrlen = 2;
580           } else {
581                     switch (addr_len) {
582                     case sizeof(nd_ipv4):
583                               af = AF_INET;
584                               break;
585                     case sizeof(nd_ipv6):
586                               af = AF_INET6;
587                               break;
588                     default:
589                               return -1;
590                               break;
591                     }
592                     hdrlen = 0;
593           }
594 
595           bp += hdrlen;
596           len -= hdrlen;
597           switch (at) {
598           case pimv2_unicast:
599                     if (len < addr_len)
600                               goto trunc;
601                     ND_TCHECK_LEN(bp, addr_len);
602                     if (af == AF_INET) {
603                               if (!silent)
604                                         ND_PRINT("%s", GET_IPADDR_STRING(bp));
605                     } else if (af == AF_INET6) {
606                               if (!silent)
607                                         ND_PRINT("%s", GET_IP6ADDR_STRING(bp));
608                     }
609                     return hdrlen + addr_len;
610           case pimv2_group:
611           case pimv2_source:
612                     if (len < addr_len + 2)
613                               goto trunc;
614                     ND_TCHECK_LEN(bp, addr_len + 2);
615                     if (af == AF_INET) {
616                               if (!silent) {
617                                         ND_PRINT("%s", GET_IPADDR_STRING(bp + 2));
618                                         if (GET_U_1(bp + 1) != 32)
619                                                   ND_PRINT("/%u", GET_U_1(bp + 1));
620                               }
621                     } else if (af == AF_INET6) {
622                               if (!silent) {
623                                         ND_PRINT("%s", GET_IP6ADDR_STRING(bp + 2));
624                                         if (GET_U_1(bp + 1) != 128)
625                                                   ND_PRINT("/%u", GET_U_1(bp + 1));
626                               }
627                     }
628                     if (GET_U_1(bp) && !silent) {
629                               if (at == pimv2_group) {
630                                         ND_PRINT("(0x%02x)", GET_U_1(bp));
631                               } else {
632                                         ND_PRINT("(%s%s%s",
633                                                   GET_U_1(bp) & 0x04 ? "S" : "",
634                                                   GET_U_1(bp) & 0x02 ? "W" : "",
635                                                   GET_U_1(bp) & 0x01 ? "R" : "");
636                                         if (GET_U_1(bp) & 0xf8) {
637                                                   ND_PRINT("+0x%02x",
638                                                              GET_U_1(bp) & 0xf8);
639                                         }
640                                         ND_PRINT(")");
641                               }
642                     }
643                     return hdrlen + 2 + addr_len;
644           default:
645                     return -1;
646           }
647 trunc:
648           return -1;
649 }
650 
651 enum checksum_status {
652           CORRECT,
653           INCORRECT,
654           UNVERIFIED
655 };
656 
657 static enum checksum_status
pimv2_check_checksum(netdissect_options * ndo,const u_char * bp,const u_char * bp2,u_int len)658 pimv2_check_checksum(netdissect_options *ndo, const u_char *bp,
659                          const u_char *bp2, u_int len)
660 {
661           const struct ip *ip;
662           u_int cksum;
663 
664           if (!ND_TTEST_LEN(bp, len)) {
665                     /* We don't have all the data. */
666                     return (UNVERIFIED);
667           }
668           ip = (const struct ip *)bp2;
669           if (IP_V(ip) == 4) {
670                     struct cksum_vec vec[1];
671 
672                     vec[0].ptr = bp;
673                     vec[0].len = len;
674                     cksum = in_cksum(vec, 1);
675                     return (cksum ? INCORRECT : CORRECT);
676           } else if (IP_V(ip) == 6) {
677                     const struct ip6_hdr *ip6;
678 
679                     ip6 = (const struct ip6_hdr *)bp2;
680                     cksum = nextproto6_cksum(ndo, ip6, bp, len, len, IPPROTO_PIM);
681                     return (cksum ? INCORRECT : CORRECT);
682           } else {
683                     return (UNVERIFIED);
684           }
685 }
686 
687 static void
pimv2_print(netdissect_options * ndo,const u_char * bp,u_int len,const u_char * bp2)688 pimv2_print(netdissect_options *ndo,
689             const u_char *bp, u_int len, const u_char *bp2)
690 {
691           const struct pim *pim = (const struct pim *)bp;
692           int advance;
693           int subtype;
694           enum checksum_status cksum_status;
695           u_int pim_typever;
696           u_int pimv2_addr_len;
697 
698           ndo->ndo_protocol = "pimv2";
699           if (len < 2) {
700                     ND_PRINT("[length %u < 2]", len);
701                     nd_print_invalid(ndo);
702                     return;
703           }
704           pim_typever = GET_U_1(pim->pim_typever);
705           /* RFC5015 allocates the high 4 bits of pim_rsv for "subtype". */
706           pimv2_addr_len = GET_U_1(pim->pim_rsv) & 0x0f;
707           if (pimv2_addr_len != 0)
708                     ND_PRINT(", RFC2117-encoding");
709 
710           if (len < 4) {
711                     ND_PRINT("[length %u < 4]", len);
712                     nd_print_invalid(ndo);
713                     return;
714           }
715           ND_PRINT(", cksum 0x%04x ", GET_BE_U_2(pim->pim_cksum));
716           if (GET_BE_U_2(pim->pim_cksum) == 0) {
717                     ND_PRINT("(unverified)");
718           } else {
719                     if (PIM_TYPE(pim_typever) == PIMV2_TYPE_REGISTER) {
720                               /*
721                                * The checksum only covers the packet header,
722                                * not the encapsulated packet.
723                                */
724                               cksum_status = pimv2_check_checksum(ndo, bp, bp2, 8);
725                               if (cksum_status == INCORRECT) {
726                                         /*
727                                          * To quote RFC 4601, "For interoperability
728                                          * reasons, a message carrying a checksum
729                                          * calculated over the entire PIM Register
730                                          * message should also be accepted."
731                                          */
732                                         cksum_status = pimv2_check_checksum(ndo, bp, bp2, len);
733                               }
734                     } else {
735                               /*
736                                * The checksum covers the entire packet.
737                                */
738                               cksum_status = pimv2_check_checksum(ndo, bp, bp2, len);
739                     }
740                     switch (cksum_status) {
741 
742                     case CORRECT:
743                               ND_PRINT("(correct)");
744                               break;
745 
746                     case INCORRECT:
747                               ND_PRINT("(incorrect)");
748                               break;
749 
750                     case UNVERIFIED:
751                               ND_PRINT("(unverified)");
752                               break;
753                     }
754           }
755           bp += 4;
756           len -= 4;
757 
758           switch (PIM_TYPE(pim_typever)) {
759           case PIMV2_TYPE_HELLO:
760               {
761                     uint16_t otype, olen;
762                     while (len > 0) {
763                               if (len < 4)
764                                         goto trunc;
765                               otype = GET_BE_U_2(bp);
766                               olen = GET_BE_U_2(bp + 2);
767                               ND_PRINT("\n\t  %s Option (%u), length %u, Value: ",
768                                         tok2str(pimv2_hello_option_values, "Unknown", otype),
769                                         otype,
770                                         olen);
771                               bp += 4;
772                               len -= 4;
773 
774                               if (len < olen)
775                                         goto trunc;
776                               ND_TCHECK_LEN(bp, olen);
777                               switch (otype) {
778                               case PIMV2_HELLO_OPTION_HOLDTIME:
779                                         if (olen != 2) {
780                                                   ND_PRINT("[option length %u != 2]", olen);
781                                                   nd_print_invalid(ndo);
782                                                   return;
783                                         } else {
784                                                   unsigned_relts_print(ndo,
785                                                                            GET_BE_U_2(bp));
786                                         }
787                                         break;
788 
789                               case PIMV2_HELLO_OPTION_LANPRUNEDELAY:
790                                         if (olen != 4) {
791                                                   ND_PRINT("[option length %u != 4]", olen);
792                                                   nd_print_invalid(ndo);
793                                                   return;
794                                         } else {
795                                                   char t_bit;
796                                                   uint16_t lan_delay, override_interval;
797                                                   lan_delay = GET_BE_U_2(bp);
798                                                   override_interval = GET_BE_U_2(bp + 2);
799                                                   t_bit = (lan_delay & 0x8000)? 1 : 0;
800                                                   lan_delay &= ~0x8000;
801                                                   ND_PRINT("\n\t    T-bit=%u, LAN delay %ums, Override interval %ums",
802                                                   t_bit, lan_delay, override_interval);
803                                         }
804                                         break;
805 
806                               case PIMV2_HELLO_OPTION_DR_PRIORITY_OLD:
807                               case PIMV2_HELLO_OPTION_DR_PRIORITY:
808                                         switch (olen) {
809                                         case 0:
810                                                   ND_PRINT("Bi-Directional Capability (Old)");
811                                                   break;
812                                         case 4:
813                                                   ND_PRINT("%u", GET_BE_U_4(bp));
814                                                   break;
815                                         default:
816                                                   ND_PRINT("[option length %u != 4]", olen);
817                                                   nd_print_invalid(ndo);
818                                                   return;
819                                                   break;
820                                         }
821                                         break;
822 
823                               case PIMV2_HELLO_OPTION_GENID:
824                                         if (olen != 4) {
825                                                   ND_PRINT("[option length %u != 4]", olen);
826                                                   nd_print_invalid(ndo);
827                                                   return;
828                                         } else {
829                                                   ND_PRINT("0x%08x", GET_BE_U_4(bp));
830                                         }
831                                         break;
832 
833                               case PIMV2_HELLO_OPTION_REFRESH_CAP:
834                                         if (olen != 4) {
835                                                   ND_PRINT("[option length %u != 4]", olen);
836                                                   nd_print_invalid(ndo);
837                                                   return;
838                                         } else {
839                                                   ND_PRINT("v%u", GET_U_1(bp));
840                                                   if (GET_U_1(bp + 1) != 0) {
841                                                             ND_PRINT(", interval ");
842                                                             unsigned_relts_print(ndo,
843                                                                                      GET_U_1(bp + 1));
844                                                   }
845                                                   if (GET_BE_U_2(bp + 2) != 0) {
846                                                             ND_PRINT(" ?0x%04x?",
847                                                                        GET_BE_U_2(bp + 2));
848                                                   }
849                                         }
850                                         break;
851 
852                               case  PIMV2_HELLO_OPTION_BIDIR_CAP:
853                                         break;
854 
855                               case PIMV2_HELLO_OPTION_ADDRESS_LIST_OLD:
856                               case PIMV2_HELLO_OPTION_ADDRESS_LIST:
857                                         if (ndo->ndo_vflag > 1) {
858                                                   const u_char *ptr = bp;
859                                                   u_int plen = len;
860                                                   while (ptr < (bp+olen)) {
861                                                             ND_PRINT("\n\t    ");
862                                                             advance = pimv2_addr_print(ndo, ptr, plen, pimv2_unicast, pimv2_addr_len, 0);
863                                                             if (advance < 0)
864                                                                       goto trunc;
865                                                             ptr += advance;
866                                                             plen -= advance;
867                                                   }
868                                         }
869                                         break;
870                               default:
871                                         if (ndo->ndo_vflag <= 1)
872                                                   print_unknown_data(ndo, bp, "\n\t    ", olen);
873                                         break;
874                               }
875                               /* do we want to see an additionally hexdump ? */
876                               if (ndo->ndo_vflag> 1)
877                                         print_unknown_data(ndo, bp, "\n\t    ", olen);
878                               bp += olen;
879                               len -= olen;
880                     }
881                     break;
882               }
883 
884           case PIMV2_TYPE_REGISTER:
885           {
886                     const struct ip *ip;
887 
888                     if (len < 4)
889                               goto trunc;
890                     ND_TCHECK_LEN(bp, PIMV2_REGISTER_FLAG_LEN);
891 
892                     ND_PRINT(", Flags [ %s ]\n\t",
893                               tok2str(pimv2_register_flag_values,
894                               "none",
895                               GET_BE_U_4(bp)));
896 
897                     bp += 4; len -= 4;
898                     /* encapsulated multicast packet */
899                     if (len == 0)
900                               goto trunc;
901                     ip = (const struct ip *)bp;
902                     switch (IP_V(ip)) {
903                 case 0: /* Null header */
904                               ND_PRINT("IP-Null-header %s > %s",
905                                         GET_IPADDR_STRING(ip->ip_src),
906                                         GET_IPADDR_STRING(ip->ip_dst));
907                               break;
908 
909                     case 4:   /* IPv4 */
910                               ip_print(ndo, bp, len);
911                               break;
912 
913                     case 6:   /* IPv6 */
914                               ip6_print(ndo, bp, len);
915                               break;
916 
917                     default:
918                               ND_PRINT("IP ver %u", IP_V(ip));
919                               break;
920                     }
921                     break;
922           }
923 
924           case PIMV2_TYPE_REGISTER_STOP:
925                     ND_PRINT(" group=");
926                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
927                               goto trunc;
928                     bp += advance; len -= advance;
929                     ND_PRINT(" source=");
930                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
931                               goto trunc;
932                     bp += advance; len -= advance;
933                     break;
934 
935           case PIMV2_TYPE_JOIN_PRUNE:
936           case PIMV2_TYPE_GRAFT:
937           case PIMV2_TYPE_GRAFT_ACK:
938 
939 
940         /*
941          * 0                   1                   2                   3
942          *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
943          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
944          *  |PIM Ver| Type  | Addr length   |           Checksum            |
945          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
946          *  |             Unicast-Upstream Neighbor Address                 |
947          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
948          *  |  Reserved     | Num groups    |          Holdtime             |
949          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
950          *  |            Encoded-Multicast Group Address-1                  |
951          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
952          *  |   Number of Joined  Sources   |   Number of Pruned Sources    |
953          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
954          *  |               Encoded-Joined Source Address-1                 |
955          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
956          *  |                             .                                 |
957          *  |                             .                                 |
958          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
959          *  |               Encoded-Joined Source Address-n                 |
960          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
961          *  |               Encoded-Pruned Source Address-1                 |
962          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
963          *  |                             .                                 |
964          *  |                             .                                 |
965          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
966          *  |               Encoded-Pruned Source Address-n                 |
967          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
968          *  |                           .                                   |
969          *  |                           .                                   |
970          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
971          *  |                Encoded-Multicast Group Address-n              |
972          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
973          */
974 
975               {
976                     uint8_t ngroup;
977                     uint16_t holdtime;
978                     uint16_t njoin;
979                     uint16_t nprune;
980                     u_int i, j;
981 
982                     if (PIM_TYPE(pim_typever) != 7) {       /*not for Graft-ACK*/
983                               ND_PRINT(", upstream-neighbor: ");
984                               if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
985                                         goto trunc;
986                               bp += advance; len -= advance;
987                     }
988                     if (len < 4)
989                               goto trunc;
990                     ND_TCHECK_4(bp);
991                     ngroup = GET_U_1(bp + 1);
992                     holdtime = GET_BE_U_2(bp + 2);
993                     ND_PRINT("\n\t  %u group(s)", ngroup);
994                     if (PIM_TYPE(pim_typever) != 7) {       /*not for Graft-ACK*/
995                               ND_PRINT(", holdtime: ");
996                               if (holdtime == 0xffff)
997                                         ND_PRINT("infinite");
998                               else
999                                         unsigned_relts_print(ndo, holdtime);
1000                     }
1001                     bp += 4; len -= 4;
1002                     for (i = 0; i < ngroup; i++) {
1003                               ND_PRINT("\n\t    group #%u: ", i+1);
1004                               if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
1005                                         goto trunc;
1006                               bp += advance; len -= advance;
1007                               if (len < 4)
1008                                         goto trunc;
1009                               ND_TCHECK_4(bp);
1010                               njoin = GET_BE_U_2(bp);
1011                               nprune = GET_BE_U_2(bp + 2);
1012                               ND_PRINT(", joined sources: %u, pruned sources: %u", njoin, nprune);
1013                               bp += 4; len -= 4;
1014                               for (j = 0; j < njoin; j++) {
1015                                         ND_PRINT("\n\t      joined source #%u: ", j+1);
1016                                         if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_source, pimv2_addr_len, 0)) < 0)
1017                                                   goto trunc;
1018                                         bp += advance; len -= advance;
1019                               }
1020                               for (j = 0; j < nprune; j++) {
1021                                         ND_PRINT("\n\t      pruned source #%u: ", j+1);
1022                                         if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_source, pimv2_addr_len, 0)) < 0)
1023                                                   goto trunc;
1024                                         bp += advance; len -= advance;
1025                               }
1026                     }
1027                     break;
1028               }
1029 
1030           case PIMV2_TYPE_BOOTSTRAP:
1031           {
1032                     u_int i, j, frpcnt;
1033 
1034                     /* Fragment Tag, Hash Mask len, and BSR-priority */
1035                     if (len < 2)
1036                               goto trunc;
1037                     ND_PRINT(" tag=%x", GET_BE_U_2(bp));
1038                     bp += 2;
1039                     len -= 2;
1040                     if (len < 1)
1041                               goto trunc;
1042                     ND_PRINT(" hashmlen=%u", GET_U_1(bp));
1043                     if (len < 2)
1044                               goto trunc;
1045                     ND_TCHECK_1(bp + 2);
1046                     ND_PRINT(" BSRprio=%u", GET_U_1(bp + 1));
1047                     bp += 2;
1048                     len -= 2;
1049 
1050                     /* Encoded-Unicast-BSR-Address */
1051                     ND_PRINT(" BSR=");
1052                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
1053                               goto trunc;
1054                     bp += advance;
1055                     len -= advance;
1056 
1057                     for (i = 0; len > 0; i++) {
1058                               /* Encoded-Group Address */
1059                               ND_PRINT(" (group%u: ", i);
1060                               if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
1061                                         goto trunc;
1062                               bp += advance;
1063                               len -= advance;
1064 
1065                               /* RP-Count, Frag RP-Cnt, and rsvd */
1066                               if (len < 1)
1067                                         goto trunc;
1068                               ND_PRINT(" RPcnt=%u", GET_U_1(bp));
1069                               if (len < 2)
1070                                         goto trunc;
1071                               frpcnt = GET_U_1(bp + 1);
1072                               ND_PRINT(" FRPcnt=%u", frpcnt);
1073                               if (len < 4)
1074                                         goto trunc;
1075                               bp += 4;
1076                               len -= 4;
1077 
1078                               for (j = 0; j < frpcnt && len > 0; j++) {
1079                                         /* each RP info */
1080                                         ND_PRINT(" RP%u=", j);
1081                                         if ((advance = pimv2_addr_print(ndo, bp, len,
1082                                                                                 pimv2_unicast,
1083                                                                                 pimv2_addr_len,
1084                                                                                 0)) < 0)
1085                                                   goto trunc;
1086                                         bp += advance;
1087                                         len -= advance;
1088 
1089                                         if (len < 2)
1090                                                   goto trunc;
1091                                         ND_PRINT(",holdtime=");
1092                                         unsigned_relts_print(ndo,
1093                                                                  GET_BE_U_2(bp));
1094                                         if (len < 3)
1095                                                   goto trunc;
1096                                         ND_PRINT(",prio=%u", GET_U_1(bp + 2));
1097                                         if (len < 4)
1098                                                   goto trunc;
1099                                         bp += 4;
1100                                         len -= 4;
1101                               }
1102                               ND_PRINT(")");
1103                     }
1104                     break;
1105           }
1106           case PIMV2_TYPE_ASSERT:
1107                     ND_PRINT(" group=");
1108                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
1109                               goto trunc;
1110                     bp += advance; len -= advance;
1111                     ND_PRINT(" src=");
1112                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
1113                               goto trunc;
1114                     bp += advance; len -= advance;
1115                     if (len < 8)
1116                               goto trunc;
1117                     ND_TCHECK_8(bp);
1118                     if (GET_U_1(bp) & 0x80)
1119                               ND_PRINT(" RPT");
1120                     ND_PRINT(" pref=%u", GET_BE_U_4(bp) & 0x7fffffff);
1121                     ND_PRINT(" metric=%u", GET_BE_U_4(bp + 4));
1122                     break;
1123 
1124           case PIMV2_TYPE_CANDIDATE_RP:
1125           {
1126                     u_int i, pfxcnt;
1127 
1128                     /* Prefix-Cnt, Priority, and Holdtime */
1129                     if (len < 1)
1130                               goto trunc;
1131                     ND_PRINT(" prefix-cnt=%u", GET_U_1(bp));
1132                     pfxcnt = GET_U_1(bp);
1133                     if (len < 2)
1134                               goto trunc;
1135                     ND_PRINT(" prio=%u", GET_U_1(bp + 1));
1136                     if (len < 4)
1137                               goto trunc;
1138                     ND_PRINT(" holdtime=");
1139                     unsigned_relts_print(ndo, GET_BE_U_2(bp + 2));
1140                     bp += 4;
1141                     len -= 4;
1142 
1143                     /* Encoded-Unicast-RP-Address */
1144                     ND_PRINT(" RP=");
1145                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
1146                               goto trunc;
1147                     bp += advance;
1148                     len -= advance;
1149 
1150                     /* Encoded-Group Addresses */
1151                     for (i = 0; i < pfxcnt && len > 0; i++) {
1152                               ND_PRINT(" Group%u=", i);
1153                               if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
1154                                         goto trunc;
1155                               bp += advance;
1156                               len -= advance;
1157                     }
1158                     break;
1159           }
1160 
1161           case PIMV2_TYPE_PRUNE_REFRESH:
1162                     ND_PRINT(" src=");
1163                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
1164                               goto trunc;
1165                     bp += advance;
1166                     len -= advance;
1167                     ND_PRINT(" grp=");
1168                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_group, pimv2_addr_len, 0)) < 0)
1169                               goto trunc;
1170                     bp += advance;
1171                     len -= advance;
1172                     ND_PRINT(" forwarder=");
1173                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0)
1174                               goto trunc;
1175                     bp += advance;
1176                     len -= advance;
1177                     if (len < 2)
1178                               goto trunc;
1179                     ND_PRINT(" TUNR ");
1180                     unsigned_relts_print(ndo, GET_BE_U_2(bp));
1181                     break;
1182 
1183           case PIMV2_TYPE_DF_ELECTION:
1184                     subtype = PIM_SUBTYPE(GET_U_1(pim->pim_rsv));
1185                     ND_PRINT("\n\t  %s,", tok2str( pimv2_df_election_flag_values,
1186                                "Unknown", subtype) );
1187 
1188                     ND_PRINT(" rpa=");
1189                     if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0) {
1190                               goto trunc;
1191                     }
1192                     bp += advance;
1193                     len -= advance;
1194                     ND_PRINT(" sender pref=%u", GET_BE_U_4(bp) );
1195                     ND_PRINT(" sender metric=%u", GET_BE_U_4(bp + 4));
1196 
1197                     bp += 8;
1198                     len -= 8;
1199 
1200                     switch (subtype) {
1201                     case PIMV2_DF_ELECTION_BACKOFF:
1202                     case PIMV2_DF_ELECTION_PASS:
1203                               ND_PRINT("\n\t  %s addr=", PIMV2_DF_ELECTION_PASS_BACKOFF_STR(subtype));
1204                               if ((advance = pimv2_addr_print(ndo, bp, len, pimv2_unicast, pimv2_addr_len, 0)) < 0) {
1205                                         goto trunc;
1206                               }
1207                               bp += advance;
1208                               len -= advance;
1209 
1210                               ND_PRINT(" %s pref=%u", PIMV2_DF_ELECTION_PASS_BACKOFF_STR(subtype), GET_BE_U_4(bp) );
1211                               ND_PRINT(" %s metric=%u", PIMV2_DF_ELECTION_PASS_BACKOFF_STR(subtype), GET_BE_U_4(bp + 4));
1212 
1213                               bp += 8;
1214                               len -= 8;
1215 
1216                               if (subtype == PIMV2_DF_ELECTION_BACKOFF) {
1217                                         ND_PRINT(" interval %dms", GET_BE_U_2(bp));
1218                               }
1219 
1220                               break;
1221                     default:
1222                               break;
1223                     }
1224                     break;
1225 
1226            default:
1227                     ND_PRINT(" [type %u]", PIM_TYPE(pim_typever));
1228                     break;
1229           }
1230 
1231           return;
1232 
1233 trunc:
1234           nd_print_trunc(ndo);
1235 }
1236