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