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[tcpdump] / print-bgp.c
1 /*
2 * Copyright (C) 1999 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * Extensively modified by Hannes Gredler (hannes@gredler.at) for more
30 * complete BGP support.
31 */
32
33 /* \summary: Border Gateway Protocol (BGP) printer */
34
35 /* specification: RFC 4271 */
36
37 #ifdef HAVE_CONFIG_H
38 #include <config.h>
39 #endif
40
41 #include "netdissect-stdinc.h"
42
43 #include <stdio.h>
44 #include <string.h>
45
46 #include "netdissect.h"
47 #include "addrtoname.h"
48 #include "extract.h"
49 #include "af.h"
50 #include "l2vpn.h"
51
52 struct bgp {
53 nd_byte bgp_marker[16];
54 nd_uint16_t bgp_len;
55 nd_uint8_t bgp_type;
56 };
57 #define BGP_SIZE 19 /* unaligned */
58
59 #define BGP_OPEN 1
60 #define BGP_UPDATE 2
61 #define BGP_NOTIFICATION 3
62 #define BGP_KEEPALIVE 4
63 #define BGP_ROUTE_REFRESH 5
64
65 static const struct tok bgp_msg_values[] = {
66 { BGP_OPEN, "Open"},
67 { BGP_UPDATE, "Update"},
68 { BGP_NOTIFICATION, "Notification"},
69 { BGP_KEEPALIVE, "Keepalive"},
70 { BGP_ROUTE_REFRESH, "Route Refresh"},
71 { 0, NULL}
72 };
73
74 struct bgp_open {
75 nd_byte bgpo_marker[16];
76 nd_uint16_t bgpo_len;
77 nd_uint8_t bgpo_type;
78 nd_uint8_t bgpo_version;
79 nd_uint16_t bgpo_myas;
80 nd_uint16_t bgpo_holdtime;
81 nd_uint32_t bgpo_id;
82 nd_uint8_t bgpo_optlen;
83 nd_uint8_t bgpo_opttype; /* RFC9072 */
84 nd_uint16_t bgpo_optlen_extended; /* RFC9072 */
85 /* options should follow */
86 };
87 #define BGP_OPEN_SIZE 29 /* unaligned */
88
89 struct bgp_opt {
90 nd_uint8_t bgpopt_type;
91 nd_uint16_t bgpopt_len; /* Can be one or two bytes, depending on RFC9072 */
92 /* variable length */
93 };
94 #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
95 #define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */
96
97 struct bgp_notification {
98 nd_byte bgpn_marker[16];
99 nd_uint16_t bgpn_len;
100 nd_uint8_t bgpn_type;
101 nd_uint8_t bgpn_major;
102 nd_uint8_t bgpn_minor;
103 };
104 #define BGP_NOTIFICATION_SIZE 21 /* unaligned */
105
106 struct bgp_route_refresh_orf {
107 nd_uint8_t refresh;
108 nd_uint8_t type;
109 nd_uint16_t len;
110 };
111
112 struct bgp_route_refresh {
113 nd_byte bgp_marker[16];
114 nd_uint16_t len;
115 nd_uint8_t type; /* No padding after this; afi is, in fact, not aligned */
116 nd_uint16_t afi;
117 nd_uint8_t subtype;
118 nd_uint8_t safi;
119 };
120
121 static const struct tok bgp_orf_refresh_type[] = {
122 { 1, "Immediate"},
123 { 2, "Defer"},
124 { 0, NULL }
125 };
126
127 static const struct tok bgp_orf_type[] = {
128 { 64, "Address Prefix ORF"},
129 { 65, "CP-ORF"},
130 { 0, NULL }
131 };
132
133 #define BGP_ROUTE_REFRESH_SIZE 23
134 #define BGP_ROUTE_REFRESH_SIZE_ORF BGP_ROUTE_REFRESH_SIZE + 5
135 #define BGP_ROUTE_REFRESH_SUBTYPE_NORMAL 0
136 #define BGP_ROUTE_REFRESH_SUBTYPE_BORR 1
137 #define BGP_ROUTE_REFRESH_SUBTYPE_EORR 2
138 #define BGP_ROUTE_REFRESH_SUBTYPE_RESERVED 255
139
140 static const struct tok bgp_route_refresh_subtype_values[] = {
141 {BGP_ROUTE_REFRESH_SUBTYPE_NORMAL, "Normal route refresh request"},
142 {BGP_ROUTE_REFRESH_SUBTYPE_BORR,
143 "Demarcation of the beginning of a route refresh"},
144 {BGP_ROUTE_REFRESH_SUBTYPE_EORR,
145 "Demarcation of the ending of a route refresh"},
146 {0, NULL}};
147
148 #define bgp_attr_lenlen(flags, p) \
149 (((flags) & 0x10) ? 2U : 1U)
150 #define bgp_attr_len(flags, p) \
151 (((flags) & 0x10) ? GET_BE_U_2(p) : GET_U_1(p))
152
153 #define BGPTYPE_ORIGIN 1
154 #define BGPTYPE_AS_PATH 2
155 #define BGPTYPE_NEXT_HOP 3
156 #define BGPTYPE_MULTI_EXIT_DISC 4
157 #define BGPTYPE_LOCAL_PREF 5
158 #define BGPTYPE_ATOMIC_AGGREGATE 6
159 #define BGPTYPE_AGGREGATOR 7
160 #define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
161 #define BGPTYPE_ORIGINATOR_ID 9 /* RFC4456 */
162 #define BGPTYPE_CLUSTER_LIST 10 /* RFC4456 */
163 #define BGPTYPE_MP_REACH_NLRI 14 /* RFC4760 */
164 #define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC4760 */
165 #define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
166 #define BGPTYPE_AS4_PATH 17 /* RFC6793 */
167 #define BGPTYPE_AGGREGATOR4 18 /* RFC6793 */
168 #define BGPTYPE_PMSI_TUNNEL 22 /* RFC6514 */
169 #define BGPTYPE_TUNNEL_ENCAP 23 /* RFC5512 */
170 #define BGPTYPE_TRAFFIC_ENG 24 /* RFC5543 */
171 #define BGPTYPE_IPV6_EXTD_COMMUNITIES 25 /* RFC5701 */
172 #define BGPTYPE_AIGP 26 /* RFC7311 */
173 #define BGPTYPE_PE_DISTINGUISHER_LABEL 27 /* RFC6514 */
174 #define BGPTYPE_ENTROPY_LABEL 28 /* RFC6790 */
175 #define BGPTYPE_LARGE_COMMUNITY 32 /* draft-ietf-idr-large-community-05 */
176 #define BGPTYPE_ATTR_SET 128 /* RFC6368 */
177
178 #define BGP_MP_NLRI_MINSIZE 3 /* End of RIB Marker detection */
179
180 static const struct tok bgp_attr_values[] = {
181 { BGPTYPE_ORIGIN, "Origin"},
182 { BGPTYPE_AS_PATH, "AS Path"},
183 { BGPTYPE_AS4_PATH, "AS4 Path"},
184 { BGPTYPE_NEXT_HOP, "Next Hop"},
185 { BGPTYPE_MULTI_EXIT_DISC, "Multi Exit Discriminator"},
186 { BGPTYPE_LOCAL_PREF, "Local Preference"},
187 { BGPTYPE_ATOMIC_AGGREGATE, "Atomic Aggregate"},
188 { BGPTYPE_AGGREGATOR, "Aggregator"},
189 { BGPTYPE_AGGREGATOR4, "Aggregator4"},
190 { BGPTYPE_COMMUNITIES, "Community"},
191 { BGPTYPE_ORIGINATOR_ID, "Originator ID"},
192 { BGPTYPE_CLUSTER_LIST, "Cluster List"},
193 { BGPTYPE_MP_REACH_NLRI, "Multi-Protocol Reach NLRI"},
194 { BGPTYPE_MP_UNREACH_NLRI, "Multi-Protocol Unreach NLRI"},
195 { BGPTYPE_EXTD_COMMUNITIES, "Extended Community"},
196 { BGPTYPE_PMSI_TUNNEL, "PMSI Tunnel"},
197 { BGPTYPE_TUNNEL_ENCAP, "Tunnel Encapsulation"},
198 { BGPTYPE_TRAFFIC_ENG, "Traffic Engineering"},
199 { BGPTYPE_IPV6_EXTD_COMMUNITIES, "IPv6 Extended Community"},
200 { BGPTYPE_AIGP, "Accumulated IGP Metric"},
201 { BGPTYPE_PE_DISTINGUISHER_LABEL, "PE Distinguisher Label"},
202 { BGPTYPE_ENTROPY_LABEL, "Entropy Label"},
203 { BGPTYPE_LARGE_COMMUNITY, "Large Community"},
204 { BGPTYPE_ATTR_SET, "Attribute Set"},
205 { 255, "Reserved for development"},
206 { 0, NULL}
207 };
208
209 #define BGP_AS_SET 1
210 #define BGP_AS_SEQUENCE 2
211 #define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */
212 #define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */
213
214 #define BGP_AS_SEG_TYPE_MIN BGP_AS_SET
215 #define BGP_AS_SEG_TYPE_MAX BGP_CONFED_AS_SET
216
217 static const struct tok bgp_as_path_segment_open_values[] = {
218 { BGP_AS_SEQUENCE, ""},
219 { BGP_AS_SET, "{ "},
220 { BGP_CONFED_AS_SEQUENCE, "( "},
221 { BGP_CONFED_AS_SET, "({ "},
222 { 0, NULL}
223 };
224
225 static const struct tok bgp_as_path_segment_close_values[] = {
226 { BGP_AS_SEQUENCE, ""},
227 { BGP_AS_SET, "}"},
228 { BGP_CONFED_AS_SEQUENCE, ")"},
229 { BGP_CONFED_AS_SET, "})"},
230 { 0, NULL}
231 };
232
233 #define BGP_OPT_AUTH 1
234 #define BGP_OPT_CAP 2
235
236 static const struct tok bgp_opt_values[] = {
237 { BGP_OPT_AUTH, "Authentication Information"},
238 { BGP_OPT_CAP, "Capabilities Advertisement"},
239 { 0, NULL}
240 };
241
242 #define BGP_CAPCODE_MP 1 /* RFC2858 */
243 #define BGP_CAPCODE_RR 2 /* RFC2918 */
244 #define BGP_CAPCODE_ORF 3 /* RFC5291 */
245 #define BGP_CAPCODE_MR 4 /* RFC3107 */
246 #define BGP_CAPCODE_EXT_NH 5 /* RFC5549 */
247 #define BGP_CAPCODE_EXT_MSG 6 /* RFC8654 */
248 #define BGP_CAPCODE_ML 8 /* RFC8277 */
249 #define BGP_CAPCODE_RESTART 64 /* RFC4724 */
250 #define BGP_CAPCODE_AS_NEW 65 /* RFC6793 */
251 #define BGP_CAPCODE_DYN_CAP 67 /* draft-ietf-idr-dynamic-cap */
252 #define BGP_CAPCODE_MULTISESS 68 /* draft-ietf-idr-bgp-multisession */
253 #define BGP_CAPCODE_ADD_PATH 69 /* RFC7911 */
254 #define BGP_CAPCODE_ENH_RR 70 /* RFC7313 */
255 #define BGP_CAPCODE_LLGR 71 /* draft-uttaro-idr-bgp-persistence-05 */
256 #define BGP_CAPCODE_RR_CISCO 128
257
258 static const struct tok bgp_capcode_values[] = {
259 { BGP_CAPCODE_MP, "Multiprotocol Extensions"},
260 { BGP_CAPCODE_RR, "Route Refresh"},
261 { BGP_CAPCODE_ORF, "Cooperative Route Filtering"},
262 { BGP_CAPCODE_MR, "Multiple Routes to a Destination"},
263 { BGP_CAPCODE_EXT_NH, "Extended Next Hop Encoding"},
264 { BGP_CAPCODE_EXT_MSG, "BGP Extended Message"},
265 { BGP_CAPCODE_ML, "Multiple Labels"},
266 { BGP_CAPCODE_RESTART, "Graceful Restart"},
267 { BGP_CAPCODE_AS_NEW, "32-Bit AS Number"},
268 { BGP_CAPCODE_DYN_CAP, "Dynamic Capability"},
269 { BGP_CAPCODE_MULTISESS, "Multisession BGP"},
270 { BGP_CAPCODE_ADD_PATH, "Multiple Paths"},
271 { BGP_CAPCODE_ENH_RR, "Enhanced Route Refresh"},
272 { BGP_CAPCODE_LLGR, "Long-lived Graceful Restart"},
273 { BGP_CAPCODE_RR_CISCO, "Route Refresh (Cisco)"},
274 { 0, NULL}
275 };
276
277 #define BGP_NOTIFY_MAJOR_MSG 1
278 #define BGP_NOTIFY_MAJOR_OPEN 2
279 #define BGP_NOTIFY_MAJOR_UPDATE 3
280 #define BGP_NOTIFY_MAJOR_HOLDTIME 4
281 #define BGP_NOTIFY_MAJOR_FSM 5
282 #define BGP_NOTIFY_MAJOR_CEASE 6
283 #define BGP_NOTIFY_MAJOR_CAP 7
284
285 static const struct tok bgp_notify_major_values[] = {
286 { BGP_NOTIFY_MAJOR_MSG, "Message Header Error"},
287 { BGP_NOTIFY_MAJOR_OPEN, "OPEN Message Error"},
288 { BGP_NOTIFY_MAJOR_UPDATE, "UPDATE Message Error"},
289 { BGP_NOTIFY_MAJOR_HOLDTIME,"Hold Timer Expired"},
290 { BGP_NOTIFY_MAJOR_FSM, "Finite State Machine Error"},
291 { BGP_NOTIFY_MAJOR_CEASE, "Cease"},
292 { BGP_NOTIFY_MAJOR_CAP, "Capability Message Error"},
293 { 0, NULL}
294 };
295
296 /* RFC 4486 */
297 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
298 /* RFC 9003 */
299 #define BGP_NOTIFY_MINOR_CEASE_SHUT 2
300 #define BGP_NOTIFY_MINOR_CEASE_RESET 4
301 /* RFC 8538 */
302 #define BGP_NOTIFY_MINOR_CEASE_HARDRESET 9
303 static const struct tok bgp_notify_minor_cease_values[] = {
304 { BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
305 { BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
306 { 3, "Peer Unconfigured"},
307 { BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
308 { 5, "Connection Rejected"},
309 { 6, "Other Configuration Change"},
310 { 7, "Connection Collision Resolution"},
311 { 8, "Out of Resources"},
312 { BGP_NOTIFY_MINOR_CEASE_HARDRESET, "Hard Reset"},
313 { 10, "BFD Down"},
314 { 0, NULL}
315 };
316
317 static const struct tok bgp_notify_minor_msg_values[] = {
318 { 1, "Connection Not Synchronized"},
319 { 2, "Bad Message Length"},
320 { 3, "Bad Message Type"},
321 { 0, NULL}
322 };
323
324 static const struct tok bgp_notify_minor_open_values[] = {
325 { 1, "Unsupported Version Number"},
326 { 2, "Bad Peer AS"},
327 { 3, "Bad BGP Identifier"},
328 { 4, "Unsupported Optional Parameter"},
329 { 5, "Authentication Failure"},
330 { 6, "Unacceptable Hold Time"},
331 { 7, "Capability Message Error"},
332 { 0, NULL}
333 };
334
335 static const struct tok bgp_notify_minor_update_values[] = {
336 { 1, "Malformed Attribute List"},
337 { 2, "Unrecognized Well-known Attribute"},
338 { 3, "Missing Well-known Attribute"},
339 { 4, "Attribute Flags Error"},
340 { 5, "Attribute Length Error"},
341 { 6, "Invalid ORIGIN Attribute"},
342 { 7, "AS Routing Loop"},
343 { 8, "Invalid NEXT_HOP Attribute"},
344 { 9, "Optional Attribute Error"},
345 { 10, "Invalid Network Field"},
346 { 11, "Malformed AS_PATH"},
347 { 0, NULL}
348 };
349
350 static const struct tok bgp_notify_minor_fsm_values[] = {
351 { 0, "Unspecified Error"},
352 { 1, "In OpenSent State"},
353 { 2, "In OpenConfirm State"},
354 { 3, "In Established State"},
355 { 0, NULL }
356 };
357
358 static const struct tok bgp_notify_minor_cap_values[] = {
359 { 1, "Invalid Action Value" },
360 { 2, "Invalid Capability Length" },
361 { 3, "Malformed Capability Value" },
362 { 4, "Unsupported Capability Code" },
363 { 0, NULL }
364 };
365
366 static const struct tok bgp_origin_values[] = {
367 { 0, "IGP"},
368 { 1, "EGP"},
369 { 2, "Incomplete"},
370 { 0, NULL}
371 };
372
373 #define BGP_PMSI_TUNNEL_RSVP_P2MP 1
374 #define BGP_PMSI_TUNNEL_LDP_P2MP 2
375 #define BGP_PMSI_TUNNEL_PIM_SSM 3
376 #define BGP_PMSI_TUNNEL_PIM_SM 4
377 #define BGP_PMSI_TUNNEL_PIM_BIDIR 5
378 #define BGP_PMSI_TUNNEL_INGRESS 6
379 #define BGP_PMSI_TUNNEL_LDP_MP2MP 7
380
381 static const struct tok bgp_pmsi_tunnel_values[] = {
382 { BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
383 { BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
384 { BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
385 { BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
386 { BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
387 { BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
388 { BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
389 { 0, NULL}
390 };
391
392 static const struct tok bgp_pmsi_flag_values[] = {
393 { 0x01, "Leaf Information required"},
394 { 0, NULL}
395 };
396
397 #define BGP_AIGP_TLV 1
398
399 static const struct tok bgp_aigp_values[] = {
400 { BGP_AIGP_TLV, "AIGP"},
401 { 0, NULL}
402 };
403
404 /* Subsequent address family identifier, RFC2283 section 7 */
405 #define SAFNUM_RES 0
406 #define SAFNUM_UNICAST 1
407 #define SAFNUM_MULTICAST 2
408 #define SAFNUM_UNIMULTICAST 3 /* deprecated now */
409 /* labeled BGP RFC3107 */
410 #define SAFNUM_LABUNICAST 4
411 /* RFC6514 */
412 #define SAFNUM_MULTICAST_VPN 5
413 /* draft-nalawade-kapoor-tunnel-safi */
414 #define SAFNUM_TUNNEL 64
415 /* RFC4761 */
416 #define SAFNUM_VPLS 65
417 /* RFC6037 */
418 #define SAFNUM_MDT 66
419 /* RFC7432 */
420 #define SAFNUM_EVPN 70
421 /* RFC4364 */
422 #define SAFNUM_VPNUNICAST 128
423 /* RFC6513 */
424 #define SAFNUM_VPNMULTICAST 129
425 #define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
426 /* RFC4684 */
427 #define SAFNUM_RT_ROUTING_INFO 132
428
429 #define BGP_VPN_RD_LEN 8
430
431 static const struct tok bgp_safi_values[] = {
432 { SAFNUM_RES, "Reserved"},
433 { SAFNUM_UNICAST, "Unicast"},
434 { SAFNUM_MULTICAST, "Multicast"},
435 { SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
436 { SAFNUM_LABUNICAST, "labeled Unicast"},
437 { SAFNUM_TUNNEL, "Tunnel"},
438 { SAFNUM_VPLS, "VPLS"},
439 { SAFNUM_MDT, "MDT"},
440 { SAFNUM_EVPN, "EVPN"},
441 { SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
442 { SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
443 { SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
444 { SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
445 { SAFNUM_MULTICAST_VPN, "Multicast VPN"},
446 { 0, NULL }
447 };
448
449 static const struct tok bgp_graceful_restart_comm_flag_values[] = {
450 { 0x8, "R" },
451 { 0x4, "N" },
452 { 0, NULL }
453 };
454
455 /* well-known community */
456 #define BGP_COMMUNITY_NO_EXPORT 0xffffff01
457 #define BGP_COMMUNITY_NO_ADVERT 0xffffff02
458 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
459
460 /* Extended community type - RFC 4360 */
461 #define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
462 #define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
463 #define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
464 #define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
465 #define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
466 #define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
467 #define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
468 /* rfc2547 bgp-mpls-vpns */
469 #define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
470 #define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
471 #define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
472 #define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
473
474 #define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
475 #define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
476 #define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
477
478 #define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
479 #define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
480
481 #define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
482
483 #define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
484 #define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
485 #define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
486 #define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
487
488 /* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
489 #define BGP_EXT_COM_EIGRP_GEN 0x8800
490 #define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
491 #define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
492 #define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
493 #define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
494 #define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
495
496 /* Optional Parameters */
497 #define BGP_OPEN_NON_EXT_OPT_TYPE_EXTENDED_LENGTH 255 /* Non-Ext OP Type */
498
499 static const struct tok bgp_extd_comm_flag_values[] = {
500 { 0x8000, "vendor-specific"},
501 { 0x4000, "non-transitive"},
502 { 0, NULL},
503 };
504
505 static const struct tok bgp_extd_comm_subtype_values[] = {
506 { BGP_EXT_COM_RT_0, "target"},
507 { BGP_EXT_COM_RT_1, "target"},
508 { BGP_EXT_COM_RT_2, "target"},
509 { BGP_EXT_COM_RO_0, "origin"},
510 { BGP_EXT_COM_RO_1, "origin"},
511 { BGP_EXT_COM_RO_2, "origin"},
512 { BGP_EXT_COM_LINKBAND, "link-BW"},
513 { BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
514 { BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
515 { BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
516 { BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
517 { BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
518 { BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
519 { BGP_EXT_COM_ENCAP, "encapsulation"},
520 { BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
521 { BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
522 { BGP_EXT_COM_L2INFO, "layer2-info"},
523 { BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
524 { BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
525 { BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
526 { BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
527 { BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
528 { BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
529 { BGP_EXT_COM_SOURCE_AS, "source-AS" },
530 { BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
531 { BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
532 { BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
533 { 0, NULL},
534 };
535
536 /* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
537 #define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
538 #define BGP_ENCAP_TUNNEL_GRE 2
539 #define BGP_ENCAP_TUNNEL_TRANSMIT 3
540 #define BGP_ENCAP_TUNNEL_IPSEC 4
541 #define BGP_ENCAP_TUNNEL_IP_IPSEC 5
542 #define BGP_ENCAP_TUNNEL_MPLS_IP 6
543 #define BGP_ENCAP_TUNNEL_IP_IP 7
544 #define BGP_ENCAP_TUNNEL_VXLAN 8
545 #define BGP_ENCAP_TUNNEL_NVGRE 9
546 #define BGP_ENCAP_TUNNEL_MPLS 10
547 #define BGP_ENCAP_TUNNEL_MPLS_GRE 11
548 #define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
549 #define BGP_ENCAP_TUNNEL_MPLS_UDP 13
550 #define BGP_ENCAP_TUNNEL_IPV6 14
551 #define BGP_ENCAP_TUNNEL_SR_TE 15
552 #define BGP_ENCAP_TUNNEL_BARE 16
553 #define BGP_ENCAP_TUNNEL_SR 17
554
555 static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
556 { BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
557 { BGP_ENCAP_TUNNEL_GRE, "GRE"},
558 { BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
559 { BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
560 { BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
561 { BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
562 { BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
563 { BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
564 { BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
565 { BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
566 { BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
567 { BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
568 { BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
569 { BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
570 { BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
571 { BGP_ENCAP_TUNNEL_BARE, "Bare"},
572 { BGP_ENCAP_TUNNEL_SR, "SR"},
573 { 0, NULL},
574 };
575
576 /* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
577 #define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
578 #define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
579 #define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
580 #define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
581 #define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
582 #define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
583 #define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
584
585 static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
586 { BGP_OSPF_RTYPE_RTR, "Router" },
587 { BGP_OSPF_RTYPE_NET, "Network" },
588 { BGP_OSPF_RTYPE_SUM, "Summary" },
589 { BGP_OSPF_RTYPE_EXT, "External" },
590 { BGP_OSPF_RTYPE_NSSA,"NSSA External" },
591 { BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
592 { 0, NULL },
593 };
594
595 /* ADD-PATH Send/Receive field values */
596 static const struct tok bgp_add_path_recvsend[] = {
597 { 1, "Receive" },
598 { 2, "Send" },
599 { 3, "Both" },
600 { 0, NULL },
601 };
602
603 #define AS_STR_SIZE sizeof("xxxxx.xxxxx")
604
605 /*
606 * as_printf
607 *
608 * Convert an AS number into a string and return string pointer.
609 *
610 * Depending on bflag is set or not, AS number is converted into ASDOT notation
611 * or plain number notation.
612 *
613 */
614 static char *
615 as_printf(netdissect_options *ndo,
616 char *str, size_t size, u_int asnum)
617 {
618 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
619 snprintf(str, size, "%u", asnum);
620 } else {
621 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
622 }
623 return str;
624 }
625
626 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
627
628 int
629 decode_prefix4(netdissect_options *ndo,
630 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
631 {
632 nd_ipv4 addr;
633 u_int plen, plenbytes;
634
635 ITEMCHECK(1);
636 plen = GET_U_1(pptr);
637 if (32 < plen)
638 return -1;
639 itemlen -= 1;
640
641 memset(&addr, 0, sizeof(addr));
642 plenbytes = (plen + 7) / 8;
643 ITEMCHECK(plenbytes);
644 GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
645 if (plen % 8) {
646 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
647 }
648 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
649 return 1 + plenbytes;
650
651 badtlv:
652 return -2;
653 }
654
655 static int
656 decode_labeled_prefix4(netdissect_options *ndo,
657 const u_char *pptr, u_int itemlen, char *buf,
658 size_t buflen)
659 {
660 nd_ipv4 addr;
661 u_int plen, plenbytes;
662
663 /* prefix length and label = 4 bytes */
664 ND_TCHECK_4(pptr);
665 ITEMCHECK(4);
666 plen = GET_U_1(pptr); /* get prefix length */
667
668 /* this is one of the weirdnesses of rfc3107
669 the label length (actually the label + COS bits)
670 is added to the prefix length;
671 we also do only read out just one label -
672 there is no real application for advertisement of
673 stacked labels in a single BGP message
674 */
675
676 if (24 > plen)
677 return -1;
678
679 plen-=24; /* adjust prefixlen - labellength */
680
681 if (32 < plen)
682 return -1;
683 itemlen -= 4;
684
685 memset(&addr, 0, sizeof(addr));
686 plenbytes = (plen + 7) / 8;
687 ITEMCHECK(plenbytes);
688 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
689 if (plen % 8) {
690 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
691 }
692 /* the label may get offsetted by 4 bits so lets shift it right */
693 snprintf(buf, buflen, "%s/%u, label:%u %s",
694 ipaddr_string(ndo, (const u_char *)&addr),
695 plen,
696 GET_BE_U_3(pptr + 1)>>4,
697 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
698
699 return 4 + plenbytes;
700
701 trunc:
702 return -2;
703
704 badtlv:
705 return -3;
706 }
707
708 /*
709 * bgp_vpn_ip_print
710 *
711 * print an ipv4 or ipv6 address into a buffer dependent on address length.
712 */
713 static char *
714 bgp_vpn_ip_print(netdissect_options *ndo,
715 const u_char *pptr, u_int addr_length)
716 {
717
718 /* worst case string is s fully formatted v6 address */
719 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
720 char *pos = addr;
721
722 switch(addr_length) {
723 case (sizeof(nd_ipv4) << 3): /* 32 */
724 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
725 break;
726 case (sizeof(nd_ipv6) << 3): /* 128 */
727 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
728 break;
729 default:
730 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
731 break;
732 }
733 pos += strlen(pos);
734
735 *(pos) = '\0';
736 return (addr);
737 }
738
739 /*
740 * bgp_vpn_sg_print
741 *
742 * print an multicast s,g entry into a buffer.
743 * the s,g entry is encoded like this.
744 *
745 * +-----------------------------------+
746 * | Multicast Source Length (1 octet) |
747 * +-----------------------------------+
748 * | Multicast Source (Variable) |
749 * +-----------------------------------+
750 * | Multicast Group Length (1 octet) |
751 * +-----------------------------------+
752 * | Multicast Group (Variable) |
753 * +-----------------------------------+
754 *
755 * return the number of bytes read from the wire.
756 */
757 static u_int
758 bgp_vpn_sg_print(netdissect_options *ndo,
759 const u_char *pptr, char *buf, size_t buflen)
760 {
761 uint8_t addr_length;
762 u_int total_length, offset;
763
764 total_length = 0;
765
766 /* Source address length, encoded in bits */
767 addr_length = GET_U_1(pptr);
768 pptr++;
769
770 /* Source address */
771 ND_TCHECK_LEN(pptr, (addr_length >> 3));
772 total_length += (addr_length >> 3) + 1;
773 offset = (u_int)strlen(buf);
774 if (addr_length) {
775 snprintf(buf + offset, buflen - offset, ", Source %s",
776 bgp_vpn_ip_print(ndo, pptr, addr_length));
777 pptr += (addr_length >> 3);
778 }
779
780 /* Group address length, encoded in bits */
781 addr_length = GET_U_1(pptr);
782 pptr++;
783
784 /* Group address */
785 ND_TCHECK_LEN(pptr, (addr_length >> 3));
786 total_length += (addr_length >> 3) + 1;
787 offset = (u_int)strlen(buf);
788 if (addr_length) {
789 snprintf(buf + offset, buflen - offset, ", Group %s",
790 bgp_vpn_ip_print(ndo, pptr, addr_length));
791 pptr += (addr_length >> 3);
792 }
793
794 trunc:
795 return (total_length);
796 }
797
798 /* Print an RFC 4364 Route Distinguisher */
799 const char *
800 bgp_vpn_rd_print(netdissect_options *ndo,
801 const u_char *pptr)
802 {
803 /* allocate space for the largest possible string */
804 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
805 char *pos = rd;
806 /* allocate space for the largest possible string */
807 char astostr[AS_STR_SIZE];
808
809 /* ok lets load the RD format */
810 switch (GET_BE_U_2(pptr)) {
811
812 case 0:
813 /* 2-byte-AS:number fmt */
814 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
815 GET_BE_U_2(pptr + 2),
816 GET_BE_U_4(pptr + 4),
817 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
818 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
819 break;
820
821 case 1:
822 /* IP-address:AS fmt */
823 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
824 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
825 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
826 GET_BE_U_2(pptr + 6));
827 break;
828
829 case 2:
830 /* 4-byte-AS:number fmt */
831 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
832 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
833 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
834 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
835 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
836 break;
837 default:
838 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
839 break;
840 }
841 pos += strlen(pos);
842 *(pos) = '\0';
843 return (rd);
844 }
845
846 /*
847 * Print an RFC 4360 Extended Community.
848 */
849 static void
850 bgp_extended_community_print(netdissect_options *ndo,
851 const u_char *pptr)
852 {
853 union { /* copy buffer for bandwidth values */
854 float f;
855 uint32_t i;
856 } bw;
857 /* allocate space for the largest possible string */
858 char astostr[AS_STR_SIZE];
859
860 switch (GET_BE_U_2(pptr)) {
861
862 case BGP_EXT_COM_RT_0:
863 case BGP_EXT_COM_RO_0:
864 case BGP_EXT_COM_L2VPN_RT_0:
865 ND_PRINT("%u:%u (= %s)",
866 GET_BE_U_2(pptr + 2),
867 GET_BE_U_4(pptr + 4),
868 GET_IPADDR_STRING(pptr+4));
869 break;
870
871 case BGP_EXT_COM_RT_1:
872 case BGP_EXT_COM_RO_1:
873 case BGP_EXT_COM_L2VPN_RT_1:
874 case BGP_EXT_COM_VRF_RT_IMP:
875 ND_PRINT("%s:%u",
876 GET_IPADDR_STRING(pptr+2),
877 GET_BE_U_2(pptr + 6));
878 break;
879
880 case BGP_EXT_COM_RT_2:
881 case BGP_EXT_COM_RO_2:
882 ND_PRINT("%s:%u",
883 as_printf(ndo, astostr, sizeof(astostr),
884 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
885 break;
886
887 case BGP_EXT_COM_LINKBAND:
888 bw.i = GET_BE_U_4(pptr + 4);
889 ND_PRINT("bandwidth: %.3f Mbps",
890 bw.f*8/1000000);
891 break;
892
893 case BGP_EXT_COM_VPN_ORIGIN:
894 case BGP_EXT_COM_VPN_ORIGIN2:
895 case BGP_EXT_COM_VPN_ORIGIN3:
896 case BGP_EXT_COM_VPN_ORIGIN4:
897 case BGP_EXT_COM_OSPF_RID:
898 case BGP_EXT_COM_OSPF_RID2:
899 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
900 break;
901
902 case BGP_EXT_COM_OSPF_RTYPE:
903 case BGP_EXT_COM_OSPF_RTYPE2:
904 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
905 GET_IPADDR_STRING(pptr+2),
906 tok2str(bgp_extd_comm_ospf_rtype_values,
907 "unknown (0x%02x)",
908 GET_U_1((pptr + 6))),
909 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
910 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
911 break;
912
913 case BGP_EXT_COM_L2INFO:
914 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
915 tok2str(l2vpn_encaps_values,
916 "unknown encaps",
917 GET_U_1((pptr + 2))),
918 GET_U_1((pptr + 3)),
919 GET_BE_U_2(pptr + 4));
920 break;
921
922 case BGP_EXT_COM_SOURCE_AS:
923 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
924 break;
925
926 case BGP_EXT_COM_ENCAP:
927 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
928 "unknown encaps",
929 GET_BE_U_2(pptr + 6)));
930 break;
931
932 default:
933 ND_PRINT("%02x%02x%02x%02x%02x%02x",
934 GET_U_1(pptr + 2),
935 GET_U_1(pptr + 3),
936 GET_U_1(pptr + 4),
937 GET_U_1(pptr + 5),
938 GET_U_1(pptr + 6),
939 GET_U_1(pptr + 7));
940 break;
941 }
942 }
943
944 /*
945 * RFC4684 (Section 4)/RFC2858 (Section 4).
946 * RTC membership prefix is structured as follows
947 * [prefix-len] [origin-as] [route-target]
948 * The route-target is encoded as RT ext-comms.
949 * Prefix-len may be 0, 32..96
950 *
951 * Note that pptr is not packet data - it is
952 * a buffer owned by our caller - therefore GET_*
953 * macros can not be used.
954 */
955 static char *
956 bgp_rt_prefix_print(netdissect_options *ndo,
957 const u_char *pptr,
958 u_int plen)
959 {
960 /* allocate space for the largest possible string */
961 char rtc_prefix_in_hex[sizeof("0000 0000 0000 0000")] = "";
962 u_int rtc_prefix_in_hex_len = 0;
963 static char output[61]; /* max response string */
964 /* allocate space for the largest possible string */
965 char astostr[AS_STR_SIZE];
966 uint16_t ec_type = 0;
967 u_int octet_count;
968 u_int i;
969
970 if (plen == 0) {
971 snprintf(output, sizeof(output), "route-target: 0:0/0");
972 return (output);
973 }
974
975 /* hex representation of the prefix */
976 octet_count = (plen+7)/8;
977 for (i=0; i<octet_count; i++) {
978 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
979 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
980 "%02x%s", *(pptr+i),
981 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
982 }
983
984 if (plen < 16) {
985 /*
986 * The prefix is too short to include the full ext-comm type,
987 * so we have no way to parse it further.
988 */
989 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
990 rtc_prefix_in_hex, plen);
991 return (output);
992 }
993
994 /*
995 * get the ext-comm type
996 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
997 * hence EXTRACT_*() macros are safe.
998 */
999 ec_type = EXTRACT_BE_U_2(pptr);
1000 switch (ec_type) {
1001 case BGP_EXT_COM_RT_0:
1002 /* 2-byte-AS:number fmt */
1003 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
1004 EXTRACT_BE_U_2(pptr+2),
1005 EXTRACT_BE_U_4(pptr+4),
1006 plen, rtc_prefix_in_hex);
1007 break;
1008
1009 case BGP_EXT_COM_RT_1:
1010 /* IP-address:AS fmt */
1011 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
1012 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
1013 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
1014 break;
1015
1016 case BGP_EXT_COM_RT_2:
1017 /* 4-byte-AS:number fmt */
1018 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
1019 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
1020 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
1021 break;
1022
1023 default:
1024 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
1025 ec_type,
1026 rtc_prefix_in_hex, plen);
1027 break;
1028 }
1029 return (output);
1030 }
1031
1032 /* RFC 4684 */
1033 static int
1034 decode_rt_routing_info(netdissect_options *ndo,
1035 const u_char *pptr)
1036 {
1037 uint8_t route_target[8];
1038 u_int plen;
1039 /* allocate space for the largest possible string */
1040 char astostr[AS_STR_SIZE];
1041 u_int num_octets;
1042
1043 /* NLRI "prefix length" from RFC 2858 Section 4. */
1044 plen = GET_U_1(pptr); /* get prefix length */
1045
1046 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1047 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1048 * target" fields inside the "prefix" depending on its length.
1049 */
1050 if (0 == plen) {
1051 /* Without "origin AS", without "route target". */
1052 ND_PRINT("\n\t default route target");
1053 return 1;
1054 }
1055
1056 if (32 > plen) {
1057 ND_PRINT("\n\t (illegal prefix length)");
1058 return -1;
1059 }
1060
1061 /* With at least "origin AS", possibly with "route target". */
1062 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
1063
1064 plen -= 32; /* adjust prefix length */
1065
1066 if (64 < plen) {
1067 ND_PRINT("\n\t (illegal prefix length)");
1068 return -1;
1069 }
1070
1071 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1072 * and gives the number of octets in the variable-length "route
1073 * target" field inside this NLRI "prefix". Look for it.
1074 */
1075 memset(&route_target, 0, sizeof(route_target));
1076 num_octets = (plen + 7) / 8;
1077 GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
1078 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1079 if (plen % 8) {
1080 ((u_char *)&route_target)[num_octets - 1] &=
1081 ((0xff00 >> (plen % 8)) & 0xff);
1082 }
1083 ND_PRINT("\n\t origin AS: %s, %s",
1084 astostr,
1085 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1086
1087 return 5 + num_octets;
1088 }
1089
1090 static int
1091 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1092 const u_char *pptr, char *buf, size_t buflen)
1093 {
1094 nd_ipv4 addr;
1095 u_int plen;
1096
1097 plen = GET_U_1(pptr); /* get prefix length */
1098
1099 if ((24+64) > plen)
1100 return -1;
1101
1102 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1103
1104 if (32 < plen)
1105 return -1;
1106
1107 memset(&addr, 0, sizeof(addr));
1108 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1109 if (plen % 8) {
1110 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1111 ((0xff00 >> (plen % 8)) & 0xff);
1112 }
1113 /* the label may get offsetted by 4 bits so lets shift it right */
1114 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1115 bgp_vpn_rd_print(ndo, pptr+4),
1116 ipaddr_string(ndo, (const u_char *)&addr),
1117 plen,
1118 GET_BE_U_3(pptr + 1)>>4,
1119 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1120
1121 return 12 + (plen + 7) / 8;
1122 }
1123
1124 /*
1125 * +-------------------------------+
1126 * | |
1127 * | RD:IPv4-address (12 octets) |
1128 * | |
1129 * +-------------------------------+
1130 * | MDT Group-address (4 octets) |
1131 * +-------------------------------+
1132 */
1133
1134 #define MDT_VPN_NLRI_LEN 16
1135
1136 static int
1137 decode_mdt_vpn_nlri(netdissect_options *ndo,
1138 const u_char *pptr, char *buf, size_t buflen)
1139 {
1140 const u_char *rd;
1141 const u_char *vpn_ip;
1142
1143 /* if the NLRI is not predefined length, quit.*/
1144 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1145 return -1;
1146 pptr++;
1147
1148 /* RD */
1149 ND_TCHECK_8(pptr);
1150 rd = pptr;
1151 pptr += 8;
1152
1153 /* IPv4 address */
1154 vpn_ip = pptr;
1155 pptr += sizeof(nd_ipv4);
1156
1157 /* MDT Group Address */
1158 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1159 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1160
1161 return MDT_VPN_NLRI_LEN + 1;
1162
1163 trunc:
1164 return -2;
1165 }
1166
1167 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1168 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1169 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1170 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1171 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1172 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1173 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1174
1175 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1176 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1177 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1178 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1179 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1180 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1181 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1182 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1183 { 0, NULL}
1184 };
1185
1186 static int
1187 decode_multicast_vpn(netdissect_options *ndo,
1188 const u_char *pptr, char *buf, size_t buflen)
1189 {
1190 /* allocate space for the largest possible string */
1191 char astostr[AS_STR_SIZE];
1192 uint8_t route_type, route_length;
1193 u_int addr_length, sg_length;
1194 u_int offset;
1195
1196 route_type = GET_U_1(pptr);
1197 pptr++;
1198 route_length = GET_U_1(pptr);
1199 pptr++;
1200
1201 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1202 tok2str(bgp_multicast_vpn_route_type_values,
1203 "Unknown", route_type),
1204 route_type, route_length);
1205
1206 switch(route_type) {
1207 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1208 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1209 offset = (u_int)strlen(buf);
1210 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1211 bgp_vpn_rd_print(ndo, pptr),
1212 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1213 (route_length - BGP_VPN_RD_LEN) << 3));
1214 break;
1215 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1216 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1217 offset = (u_int)strlen(buf);
1218 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1219 bgp_vpn_rd_print(ndo, pptr),
1220 as_printf(ndo, astostr, sizeof(astostr),
1221 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1222 break;
1223
1224 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1225 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1226 offset = (u_int)strlen(buf);
1227 snprintf(buf + offset, buflen - offset, ", RD: %s",
1228 bgp_vpn_rd_print(ndo, pptr));
1229 pptr += BGP_VPN_RD_LEN;
1230
1231 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1232 addr_length = route_length - sg_length;
1233
1234 ND_TCHECK_LEN(pptr, addr_length);
1235 offset = (u_int)strlen(buf);
1236 snprintf(buf + offset, buflen - offset, ", Originator %s",
1237 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1238 break;
1239
1240 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1241 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1242 offset = (u_int)strlen(buf);
1243 snprintf(buf + offset, buflen - offset, ", RD: %s",
1244 bgp_vpn_rd_print(ndo, pptr));
1245 pptr += BGP_VPN_RD_LEN;
1246
1247 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1248 break;
1249
1250 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1251 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1252 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1253 offset = (u_int)strlen(buf);
1254 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1255 bgp_vpn_rd_print(ndo, pptr),
1256 as_printf(ndo, astostr, sizeof(astostr),
1257 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1258 pptr += BGP_VPN_RD_LEN + 4;
1259
1260 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1261 break;
1262
1263 /*
1264 * no per route-type printing yet.
1265 */
1266 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1267 default:
1268 break;
1269 }
1270
1271 return route_length + 2;
1272
1273 trunc:
1274 return -2;
1275 }
1276
1277 /*
1278 * As I remember, some versions of systems have an snprintf() that
1279 * returns -1 if the buffer would have overflowed. If the return
1280 * value is negative, set buflen to 0, to indicate that we've filled
1281 * the buffer up.
1282 *
1283 * If the return value is greater than buflen, that means that
1284 * the buffer would have overflowed; again, set buflen to 0 in
1285 * that case.
1286 */
1287 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1288 if (stringlen<0) \
1289 buflen=0; \
1290 else if ((u_int)stringlen>buflen) \
1291 buflen=0; \
1292 else { \
1293 buflen-=stringlen; \
1294 buf+=stringlen; \
1295 }
1296
1297 static int
1298 decode_labeled_vpn_l2(netdissect_options *ndo,
1299 const u_char *pptr, char *buf, size_t buflen)
1300 {
1301 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1302 int stringlen;
1303
1304 plen = GET_BE_U_2(pptr);
1305 tlen = plen;
1306 pptr += 2;
1307 /* Old and new L2VPN NLRI share AFI/SAFI
1308 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1309 * and > 17 as old format. Complain for the middle case
1310 */
1311 if (plen == 12) {
1312 /* assume AD-only with RD, BGPNH */
1313 ND_TCHECK_LEN(pptr, 12);
1314 buf[0] = '\0';
1315 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1316 bgp_vpn_rd_print(ndo, pptr),
1317 GET_IPADDR_STRING(pptr+8));
1318 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1319 pptr += 12;
1320 tlen -= 12;
1321 return plen + 2;
1322 } else if (plen > 17) {
1323 /* assume old format */
1324 /* RD, ID, LBLKOFF, LBLBASE */
1325
1326 ND_TCHECK_LEN(pptr, 15);
1327 buf[0] = '\0';
1328 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1329 bgp_vpn_rd_print(ndo, pptr),
1330 GET_BE_U_2(pptr + 8),
1331 GET_BE_U_2(pptr + 10),
1332 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1333 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1334 pptr += 15;
1335 tlen -= 15;
1336
1337 /* ok now the variable part - lets read out TLVs*/
1338 while (tlen != 0) {
1339 if (tlen < 3) {
1340 if (buflen != 0) {
1341 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1342 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1343 }
1344 return plen + 2;
1345 }
1346 tlv_type = GET_U_1(pptr);
1347 pptr++;
1348 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1349 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1350 pptr += 2;
1351
1352 switch(tlv_type) {
1353 case 1:
1354 if (buflen != 0) {
1355 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1356 tlv_type,
1357 tlv_len);
1358 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1359 }
1360 while (ttlv_len != 0) {
1361 if (tlen < 1) {
1362 if (buflen != 0) {
1363 stringlen=snprintf(buf,buflen, " (ran past the end)");
1364 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1365 }
1366 return plen + 2;
1367 }
1368 ND_TCHECK_1(pptr);
1369 if (buflen != 0) {
1370 stringlen=snprintf(buf,buflen, "%02x",
1371 GET_U_1(pptr));
1372 pptr++;
1373 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1374 }
1375 ttlv_len--;
1376 tlen--;
1377 }
1378 break;
1379 default:
1380 if (buflen != 0) {
1381 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1382 tlv_type,
1383 tlv_len);
1384 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1385 }
1386 if (tlen < ttlv_len) {
1387 if (buflen != 0) {
1388 stringlen=snprintf(buf,buflen, " (ran past the end)");
1389 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1390 }
1391 return plen + 2;
1392 }
1393 tlen -= ttlv_len;
1394 break;
1395 }
1396 }
1397 return plen + 2;
1398 } else {
1399 /* complain bitterly ? */
1400 /* fall through */
1401 goto trunc;
1402 }
1403
1404 trunc:
1405 return -2;
1406 }
1407
1408 int
1409 decode_prefix6(netdissect_options *ndo,
1410 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1411 {
1412 nd_ipv6 addr;
1413 u_int plen, plenbytes;
1414
1415 ITEMCHECK(1);
1416 plen = GET_U_1(pd);
1417 if (128 < plen)
1418 return -1;
1419 itemlen -= 1;
1420
1421 memset(&addr, 0, sizeof(addr));
1422 plenbytes = (plen + 7) / 8;
1423 ITEMCHECK(plenbytes);
1424 GET_CPY_BYTES(&addr, pd + 1, plenbytes);
1425 if (plen % 8) {
1426 addr[plenbytes - 1] &=
1427 ((0xff00 >> (plen % 8)) & 0xff);
1428 }
1429 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1430 return 1 + plenbytes;
1431
1432 badtlv:
1433 return -2;
1434 }
1435
1436 static int
1437 decode_labeled_prefix6(netdissect_options *ndo,
1438 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1439 {
1440 nd_ipv6 addr;
1441 u_int plen, plenbytes;
1442
1443 /* prefix length and label = 4 bytes */
1444 ND_TCHECK_4(pptr);
1445 ITEMCHECK(4);
1446 plen = GET_U_1(pptr); /* get prefix length */
1447
1448 if (24 > plen)
1449 return -1;
1450
1451 plen -= 24; /* adjust prefixlen - labellength */
1452
1453 if (128 < plen)
1454 return -1;
1455 itemlen -= 4;
1456
1457 memset(&addr, 0, sizeof(addr));
1458 plenbytes = (plen + 7) / 8;
1459 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
1460 if (plen % 8) {
1461 addr[plenbytes - 1] &=
1462 ((0xff00 >> (plen % 8)) & 0xff);
1463 }
1464 /* the label may get offsetted by 4 bits so lets shift it right */
1465 snprintf(buf, buflen, "%s/%u, label:%u %s",
1466 ip6addr_string(ndo, (const u_char *)&addr),
1467 plen,
1468 GET_BE_U_3(pptr + 1)>>4,
1469 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1470
1471 return 4 + plenbytes;
1472
1473 trunc:
1474 return -2;
1475
1476 badtlv:
1477 return -3;
1478 }
1479
1480 static int
1481 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1482 const u_char *pptr, char *buf, size_t buflen)
1483 {
1484 nd_ipv6 addr;
1485 u_int plen;
1486
1487 plen = GET_U_1(pptr); /* get prefix length */
1488
1489 if ((24+64) > plen)
1490 return -1;
1491
1492 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1493
1494 if (128 < plen)
1495 return -1;
1496
1497 memset(&addr, 0, sizeof(addr));
1498 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1499 if (plen % 8) {
1500 addr[(plen + 7) / 8 - 1] &=
1501 ((0xff00 >> (plen % 8)) & 0xff);
1502 }
1503 /* the label may get offsetted by 4 bits so lets shift it right */
1504 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1505 bgp_vpn_rd_print(ndo, pptr+4),
1506 ip6addr_string(ndo, (const u_char *)&addr),
1507 plen,
1508 GET_BE_U_3(pptr + 1)>>4,
1509 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1510
1511 return 12 + (plen + 7) / 8;
1512 }
1513
1514 static int
1515 decode_clnp_prefix(netdissect_options *ndo,
1516 const u_char *pptr, char *buf, size_t buflen)
1517 {
1518 uint8_t addr[19];
1519 u_int plen;
1520
1521 plen = GET_U_1(pptr); /* get prefix length */
1522
1523 if (152 < plen)
1524 return -1;
1525
1526 memset(&addr, 0, sizeof(addr));
1527 GET_CPY_BYTES(&addr, pptr + 4, (plen + 7) / 8);
1528 if (plen % 8) {
1529 addr[(plen + 7) / 8 - 1] &=
1530 ((0xff00 >> (plen % 8)) & 0xff);
1531 }
1532 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1533 snprintf(buf, buflen, "%s/%u",
1534 isonsap_string(ndo, addr,(plen + 7) / 8),
1535 plen);
1536
1537 return 1 + (plen + 7) / 8;
1538 }
1539
1540 static int
1541 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1542 const u_char *pptr, char *buf, size_t buflen)
1543 {
1544 uint8_t addr[19];
1545 u_int plen;
1546
1547 plen = GET_U_1(pptr); /* get prefix length */
1548
1549 if ((24+64) > plen)
1550 return -1;
1551
1552 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1553
1554 if (152 < plen)
1555 return -1;
1556
1557 memset(&addr, 0, sizeof(addr));
1558 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1559 if (plen % 8) {
1560 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1561 }
1562 /* the label may get offsetted by 4 bits so lets shift it right */
1563 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1564 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1565 bgp_vpn_rd_print(ndo, pptr+4),
1566 isonsap_string(ndo, addr,(plen + 7) / 8),
1567 plen,
1568 GET_BE_U_3(pptr + 1)>>4,
1569 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1570
1571 return 12 + (plen + 7) / 8;
1572 }
1573
1574 /*
1575 * bgp_attr_get_as_size
1576 *
1577 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1578 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1579 * support, exchange AS-Path with the same path-attribute type value 0x02.
1580 */
1581 static u_int
1582 bgp_attr_get_as_size(netdissect_options *ndo,
1583 uint8_t bgpa_type, const u_char *pptr, u_int len)
1584 {
1585 const u_char *tptr = pptr;
1586
1587 /*
1588 * If the path attribute is the optional AS4 path type, then we already
1589 * know, that ASs must be encoded in 4 byte format.
1590 */
1591 if (bgpa_type == BGPTYPE_AS4_PATH) {
1592 return 4;
1593 }
1594
1595 /*
1596 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1597 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1598 * each.
1599 */
1600 while (tptr < pptr + len) {
1601 /*
1602 * If we do not find a valid segment type, our guess might be wrong.
1603 */
1604 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1605 goto trunc;
1606 }
1607 tptr += 2 + GET_U_1(tptr + 1) * 2;
1608 }
1609
1610 /*
1611 * If we correctly reached end of the AS path attribute data content,
1612 * then most likely ASs were indeed encoded as 2 bytes.
1613 */
1614 if (tptr == pptr + len) {
1615 return 2;
1616 }
1617
1618 trunc:
1619
1620 /*
1621 * We can come here, either we did not have enough data, or if we
1622 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1623 * so that calller can try to decode each AS as of 4 bytes. If indeed
1624 * there was not enough data, it will crib and end the parse anyways.
1625 */
1626 return 4;
1627 }
1628
1629 /*
1630 * The only way to know that a BGP UPDATE message is using add path is
1631 * by checking if the capability is in the OPEN message which we may have missed.
1632 * So this function checks if it is possible that the update could contain add path
1633 * and if so it checks that standard BGP doesn't make sense.
1634 */
1635 static int
1636 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1637 u_int max_prefix_length)
1638 {
1639 u_int offset, prefix_length;
1640
1641 if (length < 5) {
1642 return 0;
1643 }
1644
1645 /*
1646 * Scan through the NLRI information under the assumpetion that
1647 * it doesn't have path IDs.
1648 */
1649 for (offset = 0; offset < length;) {
1650 offset += 4;
1651 if (!ND_TTEST_1(pptr + offset)) {
1652 /* We ran out of captured data; quit scanning. */
1653 break;
1654 }
1655 prefix_length = GET_U_1(pptr + offset);
1656 /*
1657 * Add 4 to cover the path id
1658 * and check the prefix length isn't greater than 32/128.
1659 */
1660 if (prefix_length > max_prefix_length) {
1661 return 0;
1662 }
1663 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1664 offset += 1 + ((prefix_length + 7) / 8);
1665 }
1666 /* check we haven't gone past the end of the section */
1667 if (offset > length) {
1668 return 0;
1669 }
1670
1671 /* check it's not standard BGP */
1672 for (offset = 0; offset < length; ) {
1673 if (!ND_TTEST_1(pptr + offset)) {
1674 /* We ran out of captured data; quit scanning. */
1675 break;
1676 }
1677 prefix_length = GET_U_1(pptr + offset);
1678 /*
1679 * If the prefix_length is zero (0.0.0.0/0)
1680 * and since it's not the only address (length >= 5)
1681 * then it is add-path
1682 */
1683 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1684 return 1;
1685 }
1686 offset += 1 + ((prefix_length + 7) / 8);
1687 }
1688 if (offset > length) {
1689 return 1;
1690 }
1691
1692 /* assume not add-path by default */
1693 return 0;
1694 }
1695
1696 static int
1697 bgp_mp_af_print(netdissect_options *ndo,
1698 const u_char *tptr, u_int tlen,
1699 uint16_t *afp, uint8_t *safip)
1700 {
1701 uint16_t af;
1702 uint8_t safi;
1703
1704 af = GET_BE_U_2(tptr);
1705 *afp = af;
1706 safi = GET_U_1(tptr + 2);
1707 *safip = safi;
1708
1709 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1710 tok2str(af_values, "Unknown AFI", af),
1711 af,
1712 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1713 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1714 safi);
1715
1716 switch(af<<8 | safi) {
1717 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1718 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1719 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1720 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1721 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1722 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1723 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1724 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1725 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1726 case (AFNUM_INET<<8 | SAFNUM_MDT):
1727 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1728 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1729 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1730 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1731 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1732 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1733 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1734 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1735 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1736 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1737 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1738 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1739 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1740 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1741 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1742 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1743 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1744 break;
1745 default:
1746 ND_TCHECK_LEN(tptr, tlen);
1747 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1748 if (ndo->ndo_vflag <= 1)
1749 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1750 return -1;
1751 }
1752 return 0;
1753 trunc:
1754 return -2;
1755 }
1756
1757 static int
1758 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1759 const u_char *tptr, u_int len,
1760 char *buf, size_t buflen,
1761 int add_path4, int add_path6)
1762 {
1763 int advance;
1764 u_int path_id = 0;
1765
1766 switch (af<<8 | safi) {
1767 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1768 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1769 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1770 if (add_path4) {
1771 path_id = GET_BE_U_4(tptr);
1772 tptr += 4;
1773 }
1774 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1775 if (advance == -1)
1776 ND_PRINT("\n\t (illegal prefix length)");
1777 else if (advance == -2)
1778 break; /* bytes left, but not enough */
1779 else
1780 ND_PRINT("\n\t %s", buf);
1781 if (add_path4) {
1782 ND_PRINT(" Path Id: %u", path_id);
1783 advance += 4;
1784 }
1785 break;
1786 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1787 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1788 if (advance == -1)
1789 ND_PRINT("\n\t (illegal prefix length)");
1790 else if (advance == -2)
1791 goto trunc;
1792 else if (advance == -3)
1793 break; /* bytes left, but not enough */
1794 else
1795 ND_PRINT("\n\t %s", buf);
1796 break;
1797 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1798 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1799 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1800 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1801 if (advance == -1)
1802 ND_PRINT("\n\t (illegal prefix length)");
1803 else
1804 ND_PRINT("\n\t %s", buf);
1805 break;
1806 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1807 advance = decode_rt_routing_info(ndo, tptr);
1808 break;
1809 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1810 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1811 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1812 if (advance == -1)
1813 ND_PRINT("\n\t (illegal prefix length)");
1814 else if (advance == -2)
1815 goto trunc;
1816 else
1817 ND_PRINT("\n\t %s", buf);
1818 break;
1819
1820 case (AFNUM_INET<<8 | SAFNUM_MDT):
1821 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1822 if (advance == -1)
1823 ND_PRINT("\n\t (illegal prefix length)");
1824 else if (advance == -2)
1825 goto trunc;
1826 else
1827 ND_PRINT("\n\t %s", buf);
1828 break;
1829 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1830 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1831 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1832 if (add_path6) {
1833 path_id = GET_BE_U_4(tptr);
1834 tptr += 4;
1835 }
1836 advance = decode_prefix6(ndo, tptr, len, buf, buflen);
1837 if (advance == -1)
1838 ND_PRINT("\n\t (illegal prefix length)");
1839 else if (advance == -2)
1840 break; /* bytes left, but not enough */
1841 else
1842 ND_PRINT("\n\t %s", buf);
1843 if (add_path6) {
1844 ND_PRINT(" Path Id: %u", path_id);
1845 advance += 4;
1846 }
1847 break;
1848 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1849 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1850 if (advance == -1)
1851 ND_PRINT("\n\t (illegal prefix length)");
1852 else if (advance == -2)
1853 goto trunc;
1854 else if (advance == -3)
1855 break; /* bytes left, but not enough */
1856 else
1857 ND_PRINT("\n\t %s", buf);
1858 break;
1859 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1860 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1861 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1862 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1863 if (advance == -1)
1864 ND_PRINT("\n\t (illegal prefix length)");
1865 else
1866 ND_PRINT("\n\t %s", buf);
1867 break;
1868 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1869 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1870 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1871 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1872 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1873 if (advance == -1)
1874 ND_PRINT("\n\t (illegal length)");
1875 else if (advance == -2)
1876 goto trunc;
1877 else
1878 ND_PRINT("\n\t %s", buf);
1879 break;
1880 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1881 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1882 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1883 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1884 if (advance == -1)
1885 ND_PRINT("\n\t (illegal prefix length)");
1886 else
1887 ND_PRINT("\n\t %s", buf);
1888 break;
1889 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1890 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1891 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1892 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1893 if (advance == -1)
1894 ND_PRINT("\n\t (illegal prefix length)");
1895 else
1896 ND_PRINT("\n\t %s", buf);
1897 break;
1898 default:
1899 /*
1900 * This should not happen, we should have been protected
1901 * by bgp_mp_af_print()'s return value.
1902 */
1903 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1904 advance = -4;
1905 break;
1906 }
1907 return advance;
1908 trunc: /* we rely on the caller to recognize -2 return value */
1909 return -2;
1910 }
1911
1912 static const struct tok bgp_flags[] = {
1913 { 0x80, "O"},
1914 { 0x40, "T"},
1915 { 0x20, "P"},
1916 { 0x10, "E"},
1917 { 0, NULL }
1918 };
1919
1920 static int
1921 bgp_attr_print(netdissect_options *ndo,
1922 uint8_t atype, const u_char *pptr, u_int len,
1923 const unsigned attr_set_level)
1924 {
1925 /* allocate space for the largest possible string */
1926 char astostr[AS_STR_SIZE];
1927 u_int i;
1928 uint16_t af;
1929 uint8_t safi, snpa, nhlen;
1930 int advance;
1931 u_int tlen;
1932 const u_char *tptr;
1933 char buf[MAXHOSTNAMELEN + 100];
1934 u_int as_size;
1935 int add_path4, add_path6;
1936 int ret;
1937
1938 tptr = pptr;
1939 tlen = len;
1940
1941 switch (atype) {
1942 case BGPTYPE_ORIGIN:
1943 if (len != 1)
1944 ND_PRINT("invalid len");
1945 else {
1946 ND_PRINT("%s", tok2str(bgp_origin_values,
1947 "Unknown Origin Typecode",
1948 GET_U_1(tptr)));
1949 }
1950 break;
1951
1952 /*
1953 * Process AS4 byte path and AS2 byte path attributes here.
1954 */
1955 case BGPTYPE_AS4_PATH:
1956 case BGPTYPE_AS_PATH:
1957 if (len % 2) {
1958 ND_PRINT("invalid len");
1959 break;
1960 }
1961 if (!len) {
1962 ND_PRINT("empty");
1963 break;
1964 }
1965
1966 /*
1967 * BGP updates exchanged between New speakers that support 4
1968 * byte AS, ASs are always encoded in 4 bytes. There is no
1969 * definitive way to find this, just by the packet's
1970 * contents. So, check for packet's TLV's sanity assuming
1971 * 2 bytes first, and it does not pass, assume that ASs are
1972 * encoded in 4 bytes format and move on.
1973 */
1974 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1975
1976 while (tptr < pptr + len) {
1977 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1978 "?", GET_U_1(tptr)));
1979 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1980 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1981 ND_PRINT("%s ",
1982 as_printf(ndo, astostr, sizeof(astostr),
1983 as_size == 2 ?
1984 GET_BE_U_2(tptr + i + 2) :
1985 GET_BE_U_4(tptr + i + 2)));
1986 }
1987 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1988 "?", GET_U_1(tptr)));
1989 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1990 }
1991 break;
1992 case BGPTYPE_NEXT_HOP:
1993 if (len != 4)
1994 ND_PRINT("invalid len");
1995 else {
1996 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
1997 }
1998 break;
1999 case BGPTYPE_MULTI_EXIT_DISC:
2000 case BGPTYPE_LOCAL_PREF:
2001 if (len != 4)
2002 ND_PRINT("invalid len");
2003 else {
2004 ND_PRINT("%u", GET_BE_U_4(tptr));
2005 }
2006 break;
2007 case BGPTYPE_ATOMIC_AGGREGATE:
2008 if (len != 0)
2009 ND_PRINT("invalid len");
2010 break;
2011 case BGPTYPE_AGGREGATOR:
2012
2013 /*
2014 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
2015 * the length of this PA can be either 6 bytes or 8 bytes.
2016 */
2017 if (len != 6 && len != 8) {
2018 ND_PRINT("invalid len");
2019 break;
2020 }
2021 ND_TCHECK_LEN(tptr, len);
2022 if (len == 6) {
2023 ND_PRINT(" AS #%s, origin %s",
2024 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
2025 GET_IPADDR_STRING(tptr + 2));
2026 } else {
2027 ND_PRINT(" AS #%s, origin %s",
2028 as_printf(ndo, astostr, sizeof(astostr),
2029 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
2030 }
2031 break;
2032 case BGPTYPE_AGGREGATOR4:
2033 if (len != 8) {
2034 ND_PRINT("invalid len");
2035 break;
2036 }
2037 ND_PRINT(" AS #%s, origin %s",
2038 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
2039 GET_IPADDR_STRING(tptr + 4));
2040 break;
2041 case BGPTYPE_COMMUNITIES:
2042 if (len % 4) {
2043 ND_PRINT("invalid len");
2044 break;
2045 }
2046 while (tlen != 0) {
2047 uint32_t comm;
2048 ND_TCHECK_4(tptr);
2049 if (tlen < 4)
2050 goto trunc;
2051 comm = GET_BE_U_4(tptr);
2052 switch (comm) {
2053 case BGP_COMMUNITY_NO_EXPORT:
2054 ND_PRINT(" NO_EXPORT");
2055 break;
2056 case BGP_COMMUNITY_NO_ADVERT:
2057 ND_PRINT(" NO_ADVERTISE");
2058 break;
2059 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2060 ND_PRINT(" NO_EXPORT_SUBCONFED");
2061 break;
2062 default:
2063 ND_PRINT("%u:%u%s",
2064 (comm >> 16) & 0xffff,
2065 comm & 0xffff,
2066 (tlen>4) ? ", " : "");
2067 break;
2068 }
2069 tlen -=4;
2070 tptr +=4;
2071 }
2072 break;
2073 case BGPTYPE_ORIGINATOR_ID:
2074 if (len != 4) {
2075 ND_PRINT("invalid len");
2076 break;
2077 }
2078 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2079 break;
2080 case BGPTYPE_CLUSTER_LIST:
2081 if (len % 4) {
2082 ND_PRINT("invalid len");
2083 break;
2084 }
2085 while (tlen != 0) {
2086 if (tlen < 4)
2087 goto trunc;
2088 ND_PRINT("%s%s",
2089 GET_IPADDR_STRING(tptr),
2090 (tlen>4) ? ", " : "");
2091 tlen -=4;
2092 tptr +=4;
2093 }
2094 break;
2095 case BGPTYPE_MP_REACH_NLRI:
2096 ND_TCHECK_3(tptr);
2097 if (tlen < 3)
2098 goto trunc;
2099 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2100 if (ret == -2)
2101 goto trunc;
2102 if (ret < 0)
2103 break;
2104
2105 tptr += 3;
2106 tlen -= 3;
2107
2108 ND_TCHECK_1(tptr);
2109 if (tlen < 1)
2110 goto trunc;
2111 nhlen = GET_U_1(tptr);
2112 tptr++;
2113 tlen--;
2114
2115 if (nhlen) {
2116 u_int nnh = 0;
2117 uint8_t tnhlen = nhlen;
2118 if (tlen < tnhlen)
2119 goto trunc;
2120 ND_PRINT("\n\t nexthop: ");
2121 while (tnhlen != 0) {
2122 if (nnh++ > 0) {
2123 ND_PRINT(", " );
2124 }
2125 switch(af<<8 | safi) {
2126 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2127 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2128 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2129 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2130 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2131 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2132 case (AFNUM_INET<<8 | SAFNUM_MDT):
2133 if (tnhlen < sizeof(nd_ipv4)) {
2134 ND_PRINT("invalid len");
2135 tptr += tnhlen;
2136 tlen -= tnhlen;
2137 tnhlen = 0;
2138 } else {
2139 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2140 tptr += sizeof(nd_ipv4);
2141 tnhlen -= sizeof(nd_ipv4);
2142 tlen -= sizeof(nd_ipv4);
2143 }
2144 break;
2145 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2146 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2147 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2148 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2149 ND_PRINT("invalid len");
2150 tptr += tnhlen;
2151 tlen -= tnhlen;
2152 tnhlen = 0;
2153 } else {
2154 ND_PRINT("RD: %s, %s",
2155 bgp_vpn_rd_print(ndo, tptr),
2156 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2157 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2158 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2159 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2160 }
2161 break;
2162 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2163 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2164 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2165 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2166 if (tnhlen < sizeof(nd_ipv6)) {
2167 ND_PRINT("invalid len");
2168 tptr += tnhlen;
2169 tlen -= tnhlen;
2170 tnhlen = 0;
2171 } else {
2172 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2173 tptr += sizeof(nd_ipv6);
2174 tlen -= sizeof(nd_ipv6);
2175 tnhlen -= sizeof(nd_ipv6);
2176 }
2177 break;
2178 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2179 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2180 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2181 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2182 ND_PRINT("invalid len");
2183 tptr += tnhlen;
2184 tlen -= tnhlen;
2185 tnhlen = 0;
2186 } else {
2187 ND_PRINT("RD: %s, %s",
2188 bgp_vpn_rd_print(ndo, tptr),
2189 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2190 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2191 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2192 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2193 }
2194 break;
2195 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2196 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2197 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2198 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2199 if (tnhlen < sizeof(nd_ipv4)) {
2200 ND_PRINT("invalid len");
2201 tptr += tnhlen;
2202 tlen -= tnhlen;
2203 tnhlen = 0;
2204 } else {
2205 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2206 tptr += (sizeof(nd_ipv4));
2207 tlen -= (sizeof(nd_ipv4));
2208 tnhlen -= (sizeof(nd_ipv4));
2209 }
2210 break;
2211 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2212 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2213 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2214 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2215 tptr += tnhlen;
2216 tlen -= tnhlen;
2217 tnhlen = 0;
2218 break;
2219
2220 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2221 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2222 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2223 if (tnhlen < BGP_VPN_RD_LEN+1) {
2224 ND_PRINT("invalid len");
2225 tptr += tnhlen;
2226 tlen -= tnhlen;
2227 tnhlen = 0;
2228 } else {
2229 ND_TCHECK_LEN(tptr, tnhlen);
2230 ND_PRINT("RD: %s, %s",
2231 bgp_vpn_rd_print(ndo, tptr),
2232 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2233 /* rfc986 mapped IPv4 address ? */
2234 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2235 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2236 /* rfc1888 mapped IPv6 address ? */
2237 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2238 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2239 tptr += tnhlen;
2240 tlen -= tnhlen;
2241 tnhlen = 0;
2242 }
2243 break;
2244 default:
2245 /*
2246 * bgp_mp_af_print() should have saved us from
2247 * an unsupported AFI/SAFI.
2248 */
2249 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2250 tptr += tnhlen;
2251 tlen -= tnhlen;
2252 tnhlen = 0;
2253 goto done;
2254 break;
2255 }
2256 }
2257 }
2258 ND_PRINT(", nh-length: %u", nhlen);
2259
2260 /* As per RFC 2858; this is reserved in RFC 4760 */
2261 if (tlen < 1)
2262 goto trunc;
2263 snpa = GET_U_1(tptr);
2264 tptr++;
2265 tlen--;
2266
2267 if (snpa) {
2268 ND_PRINT("\n\t %u SNPA", snpa);
2269 for (/*nothing*/; snpa != 0; snpa--) {
2270 uint8_t snpalen;
2271 if (tlen < 1)
2272 goto trunc;
2273 snpalen = GET_U_1(tptr);
2274 ND_PRINT("\n\t %u bytes", snpalen);
2275 tptr++;
2276 tlen--;
2277 if (tlen < snpalen)
2278 goto trunc;
2279 ND_TCHECK_LEN(tptr, snpalen);
2280 tptr += snpalen;
2281 tlen -= snpalen;
2282 }
2283 } else {
2284 ND_PRINT(", no SNPA");
2285 }
2286
2287 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2288 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2289
2290 while (tptr < pptr + len) {
2291 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2292 add_path4, add_path6);
2293 if (advance == -2)
2294 goto trunc;
2295 if (advance < 0)
2296 break;
2297 tptr += advance;
2298 }
2299 break;
2300
2301 case BGPTYPE_MP_UNREACH_NLRI:
2302 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2303 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2304 if (ret == -2)
2305 goto trunc;
2306 if (ret < 0)
2307 break;
2308
2309 if (len == BGP_MP_NLRI_MINSIZE)
2310 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2311
2312 tptr += 3;
2313
2314 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2315 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2316
2317 while (tptr < pptr + len) {
2318 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2319 add_path4, add_path6);
2320 if (advance == -2)
2321 goto trunc;
2322 if (advance < 0)
2323 break;
2324 tptr += advance;
2325 }
2326 break;
2327 case BGPTYPE_EXTD_COMMUNITIES:
2328 if (len % 8) {
2329 ND_PRINT("invalid len");
2330 break;
2331 }
2332 while (tlen != 0) {
2333 uint16_t extd_comm;
2334
2335 ND_TCHECK_2(tptr);
2336 if (tlen < 2)
2337 goto trunc;
2338 extd_comm=GET_BE_U_2(tptr);
2339
2340 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2341 tok2str(bgp_extd_comm_subtype_values,
2342 "unknown extd community typecode",
2343 extd_comm),
2344 extd_comm,
2345 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2346
2347 ND_TCHECK_8(tptr);
2348 if (tlen < 8)
2349 goto trunc;
2350 ND_PRINT(": ");
2351 bgp_extended_community_print(ndo, tptr);
2352 tlen -= 8;
2353 tptr += 8;
2354 }
2355 break;
2356
2357 case BGPTYPE_PMSI_TUNNEL:
2358 {
2359 uint8_t tunnel_type, flags;
2360
2361 ND_TCHECK_5(tptr);
2362 if (tlen < 5)
2363 goto trunc;
2364 flags = GET_U_1(tptr);
2365 tunnel_type = GET_U_1(tptr + 1);
2366
2367 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2368 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2369 tunnel_type,
2370 bittok2str(bgp_pmsi_flag_values, "none", flags),
2371 GET_BE_U_3(tptr + 2)>>4);
2372
2373 tptr +=5;
2374 tlen -= 5;
2375
2376 switch (tunnel_type) {
2377 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2378 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2379 ND_PRINT("\n\t Sender %s, P-Group %s",
2380 GET_IPADDR_STRING(tptr),
2381 GET_IPADDR_STRING(tptr+4));
2382 break;
2383
2384 case BGP_PMSI_TUNNEL_PIM_SSM:
2385 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2386 GET_IPADDR_STRING(tptr),
2387 GET_IPADDR_STRING(tptr+4));
2388 break;
2389 case BGP_PMSI_TUNNEL_INGRESS:
2390 ND_PRINT("\n\t Tunnel-Endpoint %s",
2391 GET_IPADDR_STRING(tptr));
2392 break;
2393 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2394 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2395 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2396 GET_IPADDR_STRING(tptr),
2397 GET_BE_U_4(tptr + 4));
2398 break;
2399 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2400 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2401 GET_IPADDR_STRING(tptr),
2402 GET_BE_U_4(tptr + 4));
2403 break;
2404 default:
2405 if (ndo->ndo_vflag <= 1) {
2406 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2407 }
2408 }
2409 break;
2410 }
2411 case BGPTYPE_AIGP:
2412 {
2413 uint8_t type;
2414 uint16_t length;
2415
2416 while (tlen >= 3) {
2417 type = GET_U_1(tptr);
2418 length = GET_BE_U_2(tptr + 1);
2419 tptr += 3;
2420 tlen -= 3;
2421
2422 ND_PRINT("\n\t %s TLV (%u), length %u",
2423 tok2str(bgp_aigp_values, "Unknown", type),
2424 type, length);
2425
2426 if (length < 3)
2427 goto trunc;
2428 length -= 3;
2429
2430 /*
2431 * Check if we can read the TLV data.
2432 */
2433 if (tlen < length)
2434 goto trunc;
2435
2436 switch (type) {
2437
2438 case BGP_AIGP_TLV:
2439 if (length < 8)
2440 goto trunc;
2441 ND_PRINT(", metric %" PRIu64,
2442 GET_BE_U_8(tptr));
2443 break;
2444
2445 default:
2446 if (ndo->ndo_vflag <= 1) {
2447 print_unknown_data(ndo, tptr,"\n\t ", length);
2448 }
2449 }
2450
2451 tptr += length;
2452 tlen -= length;
2453 }
2454 break;
2455 }
2456 case BGPTYPE_ATTR_SET:
2457 ND_TCHECK_4(tptr);
2458 if (len < 4)
2459 goto trunc;
2460 ND_PRINT("\n\t Origin AS: %s",
2461 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2462 tptr += 4;
2463 len -= 4;
2464
2465 while (len) {
2466 u_int aflags, alenlen, alen;
2467
2468 ND_TCHECK_2(tptr);
2469 if (len < 2) {
2470 ND_PRINT(" [path attr too short]");
2471 tptr += len;
2472 break;
2473 }
2474 aflags = GET_U_1(tptr);
2475 atype = GET_U_1(tptr + 1);
2476 tptr += 2;
2477 len -= 2;
2478 alenlen = bgp_attr_lenlen(aflags, tptr);
2479 ND_TCHECK_LEN(tptr, alenlen);
2480 if (len < alenlen) {
2481 ND_PRINT(" [path attr too short]");
2482 tptr += len;
2483 break;
2484 }
2485 alen = bgp_attr_len(aflags, tptr);
2486 tptr += alenlen;
2487 len -= alenlen;
2488
2489 ND_PRINT("\n\t %s (%u), length: %u",
2490 tok2str(bgp_attr_values,
2491 "Unknown Attribute", atype),
2492 atype,
2493 alen);
2494
2495 if (aflags) {
2496 ND_PRINT(", Flags [%s",
2497 bittok2str_nosep(bgp_flags, "", aflags));
2498 if (aflags & 0xf)
2499 ND_PRINT("+%x", aflags & 0xf);
2500 ND_PRINT("]");
2501 }
2502 ND_PRINT(": ");
2503 if (len < alen) {
2504 ND_PRINT(" [path attr too short]");
2505 tptr += len;
2506 break;
2507 }
2508 /*
2509 * The protocol encoding per se allows ATTR_SET to be nested
2510 * as many times as the message can accommodate. This printer
2511 * used to be able to recurse into ATTR_SET contents until the
2512 * stack exhaustion, but now there is a limit on that (if live
2513 * protocol exchange goes that many levels deep, something is
2514 * probably wrong anyway). Feel free to refine this value if
2515 * you can find the spec with respective normative text.
2516 */
2517 if (attr_set_level == 10)
2518 ND_PRINT("(too many nested levels, not recursing)");
2519 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2520 return 0;
2521 tptr += alen;
2522 len -= alen;
2523 }
2524 break;
2525
2526 case BGPTYPE_LARGE_COMMUNITY:
2527 if (len == 0 || len % 12) {
2528 ND_PRINT("invalid len");
2529 break;
2530 }
2531 ND_PRINT("\n\t ");
2532 while (len != 0) {
2533 ND_PRINT("%u:%u:%u%s",
2534 GET_BE_U_4(tptr),
2535 GET_BE_U_4(tptr + 4),
2536 GET_BE_U_4(tptr + 8),
2537 (len > 12) ? ", " : "");
2538 tptr += 12;
2539 /*
2540 * len will always be a multiple of 12, as per the above,
2541 * so this will never underflow.
2542 */
2543 len -= 12;
2544 }
2545 break;
2546 default:
2547 ND_TCHECK_LEN(pptr, len);
2548 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2549 if (ndo->ndo_vflag <= 1)
2550 print_unknown_data(ndo, pptr, "\n\t ", len);
2551 break;
2552 }
2553 done:
2554 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2555 ND_TCHECK_LEN(pptr, len);
2556 print_unknown_data(ndo, pptr, "\n\t ", len);
2557 }
2558 return 1;
2559
2560 trunc:
2561 return 0;
2562 }
2563
2564 static void
2565 bgp_capabilities_print(netdissect_options *ndo,
2566 const u_char *opt, u_int caps_len)
2567 {
2568 /* allocate space for the largest possible string */
2569 char astostr[AS_STR_SIZE];
2570 u_int cap_type, cap_len, tcap_len, cap_offset;
2571 u_int i = 0;
2572
2573 while (i < caps_len) {
2574 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2575 cap_type=GET_U_1(opt + i);
2576 cap_len=GET_U_1(opt + i + 1);
2577 ND_PRINT("\n\t %s (%u), length: %u",
2578 tok2str(bgp_capcode_values, "Unknown", cap_type),
2579 cap_type,
2580 cap_len);
2581 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2582 switch (cap_type) {
2583 case BGP_CAPCODE_MP:
2584 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2585 if (cap_len < 4) {
2586 ND_PRINT(" (too short, < 4)");
2587 return;
2588 }
2589 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2590 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2591 GET_BE_U_2(opt + i + 2),
2592 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2593 GET_U_1(opt + i + 5));
2594 break;
2595 case BGP_CAPCODE_ML:
2596 cap_offset = 2;
2597 tcap_len = cap_len;
2598 while (tcap_len >= 4) {
2599 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2600 tok2str(af_values, "Unknown",
2601 GET_BE_U_2(opt + i + cap_offset)),
2602 GET_BE_U_2(opt + i + cap_offset),
2603 tok2str(bgp_safi_values, "Unknown",
2604 GET_U_1(opt + i + cap_offset + 2)),
2605 GET_U_1(opt + i + cap_offset + 2),
2606 GET_U_1(opt + i + cap_offset + 3));
2607 tcap_len -= 4;
2608 cap_offset += 4;
2609 }
2610 break;
2611 case BGP_CAPCODE_RESTART:
2612 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2613 if (cap_len < 2) {
2614 ND_PRINT(" (too short, < 2)");
2615 return;
2616 }
2617 tcap_len=cap_len;
2618 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2619 bittok2str(bgp_graceful_restart_comm_flag_values,
2620 "none", GET_U_1(opt + i + 2) >> 4),
2621 GET_BE_U_2(opt + i + 2)&0xfff);
2622 tcap_len-=2;
2623 cap_offset=4;
2624 while(tcap_len>=4) {
2625 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2626 tok2str(af_values,"Unknown",
2627 GET_BE_U_2(opt + i + cap_offset)),
2628 GET_BE_U_2(opt + i + cap_offset),
2629 tok2str(bgp_safi_values,"Unknown",
2630 GET_U_1(opt + i + cap_offset + 2)),
2631 GET_U_1(opt + (i + cap_offset + 2)),
2632 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2633 tcap_len -= 4;
2634 cap_offset += 4;
2635 }
2636 break;
2637 case BGP_CAPCODE_RR:
2638 case BGP_CAPCODE_LLGR:
2639 case BGP_CAPCODE_RR_CISCO:
2640 case BGP_CAPCODE_EXT_MSG:
2641 case BGP_CAPCODE_ENH_RR:
2642 break;
2643 case BGP_CAPCODE_AS_NEW:
2644 /*
2645 * Extract the 4 byte AS number encoded.
2646 */
2647 if (cap_len < 4) {
2648 ND_PRINT(" (too short, < 4)");
2649 return;
2650 }
2651 ND_PRINT("\n\t\t 4 Byte AS %s",
2652 as_printf(ndo, astostr, sizeof(astostr),
2653 GET_BE_U_4(opt + i + 2)));
2654 break;
2655 case BGP_CAPCODE_ADD_PATH:
2656 if (cap_len == 0) {
2657 ND_PRINT(" (bogus)"); /* length */
2658 break;
2659 }
2660 tcap_len=cap_len;
2661 cap_offset=2;
2662 while (tcap_len != 0) {
2663 if (tcap_len < 4) {
2664 nd_print_invalid(ndo);
2665 break;
2666 }
2667 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2668 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2669 GET_BE_U_2(opt + i + cap_offset),
2670 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2671 GET_U_1(opt + (i + cap_offset + 2)),
2672 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2673 );
2674 tcap_len -= 4;
2675 cap_offset += 4;
2676 }
2677 break;
2678 default:
2679 ND_PRINT("\n\t\tno decoder for Capability %u",
2680 cap_type);
2681 if (ndo->ndo_vflag <= 1)
2682 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2683 cap_len);
2684 break;
2685 }
2686 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2687 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2688 }
2689 i += BGP_CAP_HEADER_SIZE + cap_len;
2690 }
2691 return;
2692
2693 trunc:
2694 nd_print_trunc(ndo);
2695 }
2696
2697 static void
2698 bgp_open_print(netdissect_options *ndo,
2699 const u_char *dat, u_int length)
2700 {
2701 /* allocate space for the largest possible string */
2702 char astostr[AS_STR_SIZE];
2703 const struct bgp_open *bgp_open_header;
2704 u_int optslen;
2705 uint8_t opsttype;
2706 const struct bgp_opt *bgpopt;
2707 const u_char *opt;
2708 u_int i;
2709 uint8_t extended_opt_params = 0;
2710 u_int open_size = BGP_OPEN_SIZE;
2711 u_int opt_size = BGP_OPT_SIZE;
2712
2713 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2714 if (length < BGP_OPEN_SIZE)
2715 goto trunc;
2716
2717 bgp_open_header = (const struct bgp_open *)dat;
2718
2719 ND_PRINT("\n\t Version %u, ",
2720 GET_U_1(bgp_open_header->bgpo_version));
2721 ND_PRINT("my AS %s, ",
2722 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2723 ND_PRINT("Holdtime %us, ",
2724 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2725 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2726 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2727 opsttype = GET_U_1(bgp_open_header->bgpo_opttype);
2728 if (opsttype == BGP_OPEN_NON_EXT_OPT_TYPE_EXTENDED_LENGTH) {
2729 optslen = GET_BE_U_2(bgp_open_header->bgpo_optlen_extended);
2730 extended_opt_params = 1;
2731 open_size += 3;
2732 opt_size += 1;
2733 }
2734 ND_PRINT("\n\t Optional parameters%s, length: %u",
2735 extended_opt_params ? " (Extended)" : "", optslen);
2736
2737 opt = dat + open_size;
2738 length -= open_size;
2739
2740 i = 0;
2741 while (i < optslen) {
2742 uint8_t opt_type;
2743 uint16_t opt_len;
2744
2745 ND_TCHECK_LEN(opt + i, opt_size);
2746 if (length < opt_size + i)
2747 goto trunc;
2748 bgpopt = (const struct bgp_opt *)(opt + i);
2749 opt_type = GET_U_1(bgpopt->bgpopt_type);
2750 opt_len = extended_opt_params ? GET_BE_U_2(bgpopt->bgpopt_len)
2751 : GET_U_1(bgpopt->bgpopt_len);
2752 if (opt_size + i + opt_len > optslen) {
2753 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2754 opt_type, opt_len);
2755 break;
2756 }
2757
2758 ND_PRINT("\n\t Option %s (%u), length: %u",
2759 tok2str(bgp_opt_values,"Unknown",opt_type),
2760 opt_type,
2761 opt_len);
2762
2763 /* now let's decode the options we know*/
2764 switch(opt_type) {
2765
2766 case BGP_OPT_CAP:
2767 bgp_capabilities_print(ndo, opt + opt_size + i,
2768 opt_len);
2769 break;
2770
2771 case BGP_OPT_AUTH:
2772 default:
2773 ND_PRINT("\n\t no decoder for option %u",
2774 opt_type);
2775 break;
2776 }
2777 i += opt_size + opt_len;
2778 }
2779 return;
2780 trunc:
2781 nd_print_trunc(ndo);
2782 }
2783
2784 static void
2785 bgp_update_print(netdissect_options *ndo,
2786 const u_char *dat, u_int length)
2787 {
2788 const u_char *p;
2789 u_int withdrawn_routes_len;
2790 char buf[MAXHOSTNAMELEN + 100];
2791 int wpfx;
2792 u_int len;
2793 int i;
2794 int add_path;
2795 u_int path_id = 0;
2796
2797 ND_TCHECK_LEN(dat, BGP_SIZE);
2798 if (length < BGP_SIZE)
2799 goto trunc;
2800 p = dat + BGP_SIZE;
2801 length -= BGP_SIZE;
2802
2803 /* Unfeasible routes */
2804 ND_TCHECK_2(p);
2805 if (length < 2)
2806 goto trunc;
2807 withdrawn_routes_len = GET_BE_U_2(p);
2808 p += 2;
2809 length -= 2;
2810 if (withdrawn_routes_len > 1) {
2811 /*
2812 * Without keeping state from the original NLRI message,
2813 * it's not possible to tell if this a v4 or v6 route,
2814 * so only try to decode it if we're not v6 enabled.
2815 */
2816 ND_TCHECK_LEN(p, withdrawn_routes_len);
2817 if (length < withdrawn_routes_len)
2818 goto trunc;
2819 ND_PRINT("\n\t Withdrawn routes:");
2820 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2821 while (withdrawn_routes_len != 0) {
2822 if (add_path) {
2823 if (withdrawn_routes_len < 4) {
2824 p += withdrawn_routes_len;
2825 length -= withdrawn_routes_len;
2826 break;
2827 }
2828 path_id = GET_BE_U_4(p);
2829 p += 4;
2830 length -= 4;
2831 withdrawn_routes_len -= 4;
2832 }
2833 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2834 if (wpfx == -1) {
2835 ND_PRINT("\n\t (illegal prefix length)");
2836 break;
2837 } else if (wpfx == -2)
2838 goto trunc; /* bytes left, but not enough */
2839 else {
2840 ND_PRINT("\n\t %s", buf);
2841 if (add_path) {
2842 ND_PRINT(" Path Id: %u", path_id);
2843 }
2844 p += wpfx;
2845 length -= wpfx;
2846 withdrawn_routes_len -= wpfx;
2847 }
2848 }
2849 } else {
2850 ND_TCHECK_LEN(p, withdrawn_routes_len);
2851 if (length < withdrawn_routes_len)
2852 goto trunc;
2853 p += withdrawn_routes_len;
2854 length -= withdrawn_routes_len;
2855 }
2856
2857 ND_TCHECK_2(p);
2858 if (length < 2)
2859 goto trunc;
2860 len = GET_BE_U_2(p);
2861 p += 2;
2862 length -= 2;
2863
2864 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2865 /* No withdrawn routes, no path attributes, no NLRI */
2866 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2867 return;
2868 }
2869
2870 if (len) {
2871 /* Make sure the path attributes don't go past the end of the packet */
2872 if (length < len)
2873 goto trunc;
2874 /* do something more useful!*/
2875 while (len) {
2876 uint8_t aflags, atype, alenlen;
2877 uint16_t alen;
2878
2879 ND_TCHECK_2(p);
2880 if (length < 2)
2881 goto trunc;
2882 if (len < 2) {
2883 ND_PRINT("\n\t [path attrs too short]");
2884 p += len;
2885 length -= len;
2886 break;
2887 }
2888 aflags = GET_U_1(p);
2889 atype = GET_U_1(p + 1);
2890 p += 2;
2891 len -= 2;
2892 length -= 2;
2893 alenlen = bgp_attr_lenlen(aflags, p);
2894 ND_TCHECK_LEN(p, alenlen);
2895 if (length < alenlen)
2896 goto trunc;
2897 if (len < alenlen) {
2898 ND_PRINT("\n\t [path attrs too short]");
2899 p += len;
2900 length -= len;
2901 break;
2902 }
2903 alen = bgp_attr_len(aflags, p);
2904 p += alenlen;
2905 len -= alenlen;
2906 length -= alenlen;
2907
2908 ND_PRINT("\n\t %s (%u), length: %u",
2909 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2910 atype,
2911 alen);
2912
2913 if (aflags) {
2914 ND_PRINT(", Flags [%s",
2915 bittok2str_nosep(bgp_flags, "", aflags));
2916 if (aflags & 0xf)
2917 ND_PRINT("+%x", aflags & 0xf);
2918 ND_PRINT("]: ");
2919 }
2920 if (len < alen) {
2921 ND_PRINT(" [path attrs too short]");
2922 p += len;
2923 length -= len;
2924 break;
2925 }
2926 if (length < alen)
2927 goto trunc;
2928 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2929 goto trunc;
2930 p += alen;
2931 len -= alen;
2932 length -= alen;
2933 }
2934 }
2935
2936 if (length) {
2937 add_path = check_add_path(ndo, p, length, 32);
2938 ND_PRINT("\n\t Updated routes:");
2939 while (length != 0) {
2940 if (add_path) {
2941 ND_TCHECK_4(p);
2942 if (length < 4)
2943 goto trunc;
2944 path_id = GET_BE_U_4(p);
2945 p += 4;
2946 length -= 4;
2947 }
2948 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2949 if (i == -1) {
2950 ND_PRINT("\n\t (illegal prefix length)");
2951 break;
2952 } else if (i == -2)
2953 goto trunc; /* bytes left, but not enough */
2954 else {
2955 ND_PRINT("\n\t %s", buf);
2956 if (add_path) {
2957 ND_PRINT(" Path Id: %u", path_id);
2958 }
2959 p += i;
2960 length -= i;
2961 }
2962 }
2963 }
2964 return;
2965 trunc:
2966 nd_print_trunc(ndo);
2967 }
2968
2969 static void
2970 bgp_notification_print_code(netdissect_options *ndo,
2971 const u_char *dat, u_int length,
2972 uint8_t bgpn_major, uint8_t bgpn_minor)
2973 {
2974 ND_PRINT(", %s (%u)",
2975 tok2str(bgp_notify_major_values, "Unknown Error",
2976 bgpn_major),
2977 bgpn_major);
2978
2979 switch (bgpn_major) {
2980
2981 case BGP_NOTIFY_MAJOR_MSG:
2982 ND_PRINT(", subcode %s (%u)",
2983 tok2str(bgp_notify_minor_msg_values, "Unknown",
2984 bgpn_minor),
2985 bgpn_minor);
2986 break;
2987 case BGP_NOTIFY_MAJOR_OPEN:
2988 ND_PRINT(", subcode %s (%u)",
2989 tok2str(bgp_notify_minor_open_values, "Unknown",
2990 bgpn_minor),
2991 bgpn_minor);
2992 break;
2993 case BGP_NOTIFY_MAJOR_UPDATE:
2994 ND_PRINT(", subcode %s (%u)",
2995 tok2str(bgp_notify_minor_update_values, "Unknown",
2996 bgpn_minor),
2997 bgpn_minor);
2998 break;
2999 case BGP_NOTIFY_MAJOR_FSM:
3000 ND_PRINT(" subcode %s (%u)",
3001 tok2str(bgp_notify_minor_fsm_values, "Unknown",
3002 bgpn_minor),
3003 bgpn_minor);
3004 break;
3005 case BGP_NOTIFY_MAJOR_CAP:
3006 ND_PRINT(" subcode %s (%u)",
3007 tok2str(bgp_notify_minor_cap_values, "Unknown",
3008 bgpn_minor),
3009 bgpn_minor);
3010 break;
3011 case BGP_NOTIFY_MAJOR_CEASE:
3012 ND_PRINT(", subcode %s (%u)",
3013 tok2str(bgp_notify_minor_cease_values, "Unknown",
3014 bgpn_minor),
3015 bgpn_minor);
3016
3017 /* RFC 4486 mentions optionally 7 bytes
3018 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
3019 */
3020 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= 7) {
3021 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
3022 tok2str(af_values, "Unknown", GET_BE_U_2(dat)),
3023 GET_BE_U_2(dat),
3024 tok2str(bgp_safi_values, "Unknown", GET_U_1((dat + 2))),
3025 GET_U_1((dat + 2)),
3026 GET_BE_U_4(dat + 3));
3027 }
3028 /*
3029 * RFC 9003 describes a method to send a communication
3030 * intended for human consumption regarding the Administrative Shutdown
3031 */
3032 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
3033 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
3034 length >= 1) {
3035 uint8_t shutdown_comm_length = GET_U_1(dat);
3036 uint8_t remainder_offset = 0;
3037 /* garbage, hexdump it all */
3038 if (shutdown_comm_length > length - 1) {
3039 ND_PRINT(", invalid Shutdown Communication length");
3040 }
3041 else if (shutdown_comm_length == 0) {
3042 ND_PRINT(", empty Shutdown Communication");
3043 remainder_offset += 1;
3044 }
3045 /* a proper shutdown communication */
3046 else {
3047 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3048 nd_printjn(ndo, dat+1, shutdown_comm_length);
3049 ND_PRINT("\"");
3050 remainder_offset += shutdown_comm_length + 1;
3051 }
3052 /* if there is trailing data, hexdump it */
3053 if(length - remainder_offset > 0) {
3054 ND_PRINT(", Data: (length: %u)", length - remainder_offset);
3055 hex_print(ndo, "\n\t\t", dat + remainder_offset, length - remainder_offset);
3056 }
3057 }
3058 /*
3059 * RFC8538 describes the Hard Reset cease subcode, which contains another
3060 * notification code and subcode.
3061 */
3062 if (bgpn_minor == BGP_NOTIFY_MINOR_CEASE_HARDRESET && length >= 2) {
3063 bgpn_major = GET_U_1(dat++);
3064 bgpn_minor = GET_U_1(dat++);
3065 length -= 2;
3066 bgp_notification_print_code(ndo, dat, length, bgpn_major, bgpn_minor);
3067 }
3068 break;
3069 default:
3070 if (bgpn_minor != 0) {
3071 ND_PRINT(", subcode %u", bgpn_minor);
3072 }
3073 break;
3074 }
3075
3076 return;
3077 }
3078
3079 static void
3080 bgp_notification_print(netdissect_options *ndo,
3081 const u_char *dat, u_int length)
3082 {
3083 const struct bgp_notification *bgp_notification_header;
3084 uint8_t bgpn_major, bgpn_minor;
3085
3086 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
3087 if (length<BGP_NOTIFICATION_SIZE)
3088 return;
3089
3090 bgp_notification_header = (const struct bgp_notification *)dat;
3091 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
3092 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
3093 bgp_notification_print_code(ndo, dat + BGP_NOTIFICATION_SIZE,
3094 length - BGP_NOTIFICATION_SIZE, bgpn_major, bgpn_minor);
3095 return;
3096 trunc:
3097 nd_print_trunc(ndo);
3098 }
3099
3100 static void
3101 bgp_route_refresh_print(netdissect_options *ndo,
3102 const u_char *pptr, u_int len)
3103 {
3104 const struct bgp_route_refresh *bgp_route_refresh_header;
3105
3106 /* some little sanity checking */
3107 if (len<BGP_ROUTE_REFRESH_SIZE)
3108 return;
3109
3110 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3111
3112 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u), Subtype %s (%u)",
3113 tok2str(af_values, "Unknown",
3114 GET_BE_U_2(bgp_route_refresh_header->afi)),
3115 GET_BE_U_2(bgp_route_refresh_header->afi),
3116 tok2str(bgp_safi_values, "Unknown",
3117 GET_U_1(bgp_route_refresh_header->safi)),
3118 GET_U_1(bgp_route_refresh_header->safi),
3119 tok2str(bgp_route_refresh_subtype_values, "Unknown",
3120 GET_U_1(bgp_route_refresh_header->subtype)),
3121 GET_U_1(bgp_route_refresh_header->subtype));
3122
3123 /* ORF */
3124 if (len >= BGP_ROUTE_REFRESH_SIZE_ORF) {
3125 const struct bgp_route_refresh_orf *orf_header;
3126
3127 orf_header =
3128 (const struct bgp_route_refresh_orf *)(pptr + BGP_ROUTE_REFRESH_SIZE);
3129
3130 ND_PRINT("\n\t ORF refresh %s (%u), ORF type %s (%u), ORF length %u",
3131 tok2str(bgp_orf_refresh_type, "Unknown",
3132 GET_U_1(orf_header->refresh)),
3133 GET_U_1(orf_header->refresh),
3134 tok2str(bgp_orf_type, "Unknown", GET_U_1(orf_header->type)),
3135 GET_U_1(orf_header->type), GET_BE_U_2(orf_header->len));
3136 }
3137
3138 if (ndo->ndo_vflag > 1) {
3139 ND_TCHECK_LEN(pptr, len);
3140 print_unknown_data(ndo, pptr, "\n\t ", len);
3141 }
3142
3143 return;
3144 trunc:
3145 nd_print_trunc(ndo);
3146 }
3147
3148 static int
3149 bgp_pdu_print(netdissect_options *ndo,
3150 const u_char *dat, u_int length)
3151 {
3152 const struct bgp *bgp_header;
3153 uint8_t bgp_type;
3154
3155 ND_TCHECK_LEN(dat, BGP_SIZE);
3156 bgp_header = (const struct bgp *)dat;
3157 bgp_type = GET_U_1(bgp_header->bgp_type);
3158
3159 ND_PRINT("\n\t%s Message (%u), length: %u",
3160 tok2str(bgp_msg_values, "Unknown", bgp_type),
3161 bgp_type,
3162 length);
3163
3164 switch (bgp_type) {
3165 case BGP_OPEN:
3166 bgp_open_print(ndo, dat, length);
3167 break;
3168 case BGP_UPDATE:
3169 bgp_update_print(ndo, dat, length);
3170 break;
3171 case BGP_NOTIFICATION:
3172 bgp_notification_print(ndo, dat, length);
3173 break;
3174 case BGP_KEEPALIVE:
3175 break;
3176 case BGP_ROUTE_REFRESH:
3177 bgp_route_refresh_print(ndo, dat, length);
3178 break;
3179 default:
3180 /* we have no decoder for the BGP message */
3181 ND_TCHECK_LEN(dat, length);
3182 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3183 print_unknown_data(ndo, dat, "\n\t ", length);
3184 break;
3185 }
3186 return 1;
3187 trunc:
3188 nd_print_trunc(ndo);
3189 return 0;
3190 }
3191
3192 void
3193 bgp_print(netdissect_options *ndo,
3194 const u_char *dat, u_int length _U_)
3195 {
3196 const u_char *p;
3197 const u_char *ep = ndo->ndo_snapend;
3198 const u_char *start;
3199 const u_char marker[] = {
3200 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3201 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3202 };
3203 const struct bgp *bgp_header;
3204 uint16_t hlen;
3205
3206 ndo->ndo_protocol = "bgp";
3207 ND_PRINT(": BGP");
3208
3209 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3210 return;
3211
3212 p = dat;
3213 start = p;
3214 while (p < ep) {
3215 if (!ND_TTEST_1(p))
3216 break;
3217 if (GET_U_1(p) != 0xff) {
3218 p++;
3219 continue;
3220 }
3221
3222 if (!ND_TTEST_LEN(p, sizeof(marker)))
3223 break;
3224 if (memcmp(p, marker, sizeof(marker)) != 0) {
3225 p++;
3226 continue;
3227 }
3228
3229 /* found BGP header */
3230 ND_TCHECK_LEN(p, BGP_SIZE);
3231 bgp_header = (const struct bgp *)p;
3232
3233 if (start != p)
3234 nd_print_trunc(ndo);
3235
3236 hlen = GET_BE_U_2(bgp_header->bgp_len);
3237 if (hlen < BGP_SIZE) {
3238 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3239 nd_print_invalid(ndo);
3240 break;
3241 }
3242
3243 if (ND_TTEST_LEN(p, hlen)) {
3244 if (!bgp_pdu_print(ndo, p, hlen))
3245 return;
3246 p += hlen;
3247 start = p;
3248 } else {
3249 ND_PRINT("\n[|BGP %s]",
3250 tok2str(bgp_msg_values,
3251 "Unknown Message Type",
3252 GET_U_1(bgp_header->bgp_type)));
3253 break;
3254 }
3255 }
3256
3257 return;
3258
3259 trunc:
3260 nd_print_trunc(ndo);
3261 }
[mirror] the TCPdump network dissector