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Remove some now redundant ND_TCHECK_LEN(e, sizeof(nd_ipv6)) calls
[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 /* options should follow */
84 };
85 #define BGP_OPEN_SIZE 29 /* unaligned */
86
87 struct bgp_opt {
88 nd_uint8_t bgpopt_type;
89 nd_uint8_t bgpopt_len;
90 /* variable length */
91 };
92 #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
93 #define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */
94
95 struct bgp_notification {
96 nd_byte bgpn_marker[16];
97 nd_uint16_t bgpn_len;
98 nd_uint8_t bgpn_type;
99 nd_uint8_t bgpn_major;
100 nd_uint8_t bgpn_minor;
101 };
102 #define BGP_NOTIFICATION_SIZE 21 /* unaligned */
103
104 struct bgp_route_refresh {
105 nd_byte bgp_marker[16];
106 nd_uint16_t len;
107 nd_uint8_t type; /* No padding after this; afi is, in fact, not aligned */
108 nd_uint16_t afi;
109 nd_uint8_t res;
110 nd_uint8_t safi;
111 };
112 #define BGP_ROUTE_REFRESH_SIZE 23
113
114 #define bgp_attr_lenlen(flags, p) \
115 (((flags) & 0x10) ? 2U : 1U)
116 #define bgp_attr_len(flags, p) \
117 (((flags) & 0x10) ? GET_BE_U_2(p) : GET_U_1(p))
118
119 #define BGPTYPE_ORIGIN 1
120 #define BGPTYPE_AS_PATH 2
121 #define BGPTYPE_NEXT_HOP 3
122 #define BGPTYPE_MULTI_EXIT_DISC 4
123 #define BGPTYPE_LOCAL_PREF 5
124 #define BGPTYPE_ATOMIC_AGGREGATE 6
125 #define BGPTYPE_AGGREGATOR 7
126 #define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
127 #define BGPTYPE_ORIGINATOR_ID 9 /* RFC4456 */
128 #define BGPTYPE_CLUSTER_LIST 10 /* RFC4456 */
129 #define BGPTYPE_DPA 11 /* deprecated, draft-ietf-idr-bgp-dpa */
130 #define BGPTYPE_ADVERTISERS 12 /* deprecated RFC1863 */
131 #define BGPTYPE_RCID_PATH 13 /* deprecated RFC1863 */
132 #define BGPTYPE_MP_REACH_NLRI 14 /* RFC4760 */
133 #define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC4760 */
134 #define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
135 #define BGPTYPE_AS4_PATH 17 /* RFC6793 */
136 #define BGPTYPE_AGGREGATOR4 18 /* RFC6793 */
137 #define BGPTYPE_PMSI_TUNNEL 22 /* RFC6514 */
138 #define BGPTYPE_TUNNEL_ENCAP 23 /* RFC5512 */
139 #define BGPTYPE_TRAFFIC_ENG 24 /* RFC5543 */
140 #define BGPTYPE_IPV6_EXTD_COMMUNITIES 25 /* RFC5701 */
141 #define BGPTYPE_AIGP 26 /* RFC7311 */
142 #define BGPTYPE_PE_DISTINGUISHER_LABEL 27 /* RFC6514 */
143 #define BGPTYPE_ENTROPY_LABEL 28 /* RFC6790 */
144 #define BGPTYPE_LARGE_COMMUNITY 32 /* draft-ietf-idr-large-community-05 */
145 #define BGPTYPE_ATTR_SET 128 /* RFC6368 */
146
147 #define BGP_MP_NLRI_MINSIZE 3 /* End of RIB Marker detection */
148
149 static const struct tok bgp_attr_values[] = {
150 { BGPTYPE_ORIGIN, "Origin"},
151 { BGPTYPE_AS_PATH, "AS Path"},
152 { BGPTYPE_AS4_PATH, "AS4 Path"},
153 { BGPTYPE_NEXT_HOP, "Next Hop"},
154 { BGPTYPE_MULTI_EXIT_DISC, "Multi Exit Discriminator"},
155 { BGPTYPE_LOCAL_PREF, "Local Preference"},
156 { BGPTYPE_ATOMIC_AGGREGATE, "Atomic Aggregate"},
157 { BGPTYPE_AGGREGATOR, "Aggregator"},
158 { BGPTYPE_AGGREGATOR4, "Aggregator4"},
159 { BGPTYPE_COMMUNITIES, "Community"},
160 { BGPTYPE_ORIGINATOR_ID, "Originator ID"},
161 { BGPTYPE_CLUSTER_LIST, "Cluster List"},
162 { BGPTYPE_DPA, "DPA"},
163 { BGPTYPE_ADVERTISERS, "Advertisers"},
164 { BGPTYPE_RCID_PATH, "RCID Path / Cluster ID"},
165 { BGPTYPE_MP_REACH_NLRI, "Multi-Protocol Reach NLRI"},
166 { BGPTYPE_MP_UNREACH_NLRI, "Multi-Protocol Unreach NLRI"},
167 { BGPTYPE_EXTD_COMMUNITIES, "Extended Community"},
168 { BGPTYPE_PMSI_TUNNEL, "PMSI Tunnel"},
169 { BGPTYPE_TUNNEL_ENCAP, "Tunnel Encapsulation"},
170 { BGPTYPE_TRAFFIC_ENG, "Traffic Engineering"},
171 { BGPTYPE_IPV6_EXTD_COMMUNITIES, "IPv6 Extended Community"},
172 { BGPTYPE_AIGP, "Accumulated IGP Metric"},
173 { BGPTYPE_PE_DISTINGUISHER_LABEL, "PE Distinguisher Label"},
174 { BGPTYPE_ENTROPY_LABEL, "Entropy Label"},
175 { BGPTYPE_LARGE_COMMUNITY, "Large Community"},
176 { BGPTYPE_ATTR_SET, "Attribute Set"},
177 { 255, "Reserved for development"},
178 { 0, NULL}
179 };
180
181 #define BGP_AS_SET 1
182 #define BGP_AS_SEQUENCE 2
183 #define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */
184 #define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */
185
186 #define BGP_AS_SEG_TYPE_MIN BGP_AS_SET
187 #define BGP_AS_SEG_TYPE_MAX BGP_CONFED_AS_SET
188
189 static const struct tok bgp_as_path_segment_open_values[] = {
190 { BGP_AS_SEQUENCE, ""},
191 { BGP_AS_SET, "{ "},
192 { BGP_CONFED_AS_SEQUENCE, "( "},
193 { BGP_CONFED_AS_SET, "({ "},
194 { 0, NULL}
195 };
196
197 static const struct tok bgp_as_path_segment_close_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 #define BGP_OPT_AUTH 1
206 #define BGP_OPT_CAP 2
207
208 static const struct tok bgp_opt_values[] = {
209 { BGP_OPT_AUTH, "Authentication Information"},
210 { BGP_OPT_CAP, "Capabilities Advertisement"},
211 { 0, NULL}
212 };
213
214 #define BGP_CAPCODE_MP 1 /* RFC2858 */
215 #define BGP_CAPCODE_RR 2 /* RFC2918 */
216 #define BGP_CAPCODE_ORF 3 /* RFC5291 */
217 #define BGP_CAPCODE_MR 4 /* RFC3107 */
218 #define BGP_CAPCODE_EXT_NH 5 /* RFC5549 */
219 #define BGP_CAPCODE_ML 8 /* RFC8277 */
220 #define BGP_CAPCODE_RESTART 64 /* RFC4724 */
221 #define BGP_CAPCODE_AS_NEW 65 /* RFC6793 */
222 #define BGP_CAPCODE_DYN_CAP 67 /* draft-ietf-idr-dynamic-cap */
223 #define BGP_CAPCODE_MULTISESS 68 /* draft-ietf-idr-bgp-multisession */
224 #define BGP_CAPCODE_ADD_PATH 69 /* RFC7911 */
225 #define BGP_CAPCODE_ENH_RR 70 /* draft-keyur-bgp-enhanced-route-refresh */
226 #define BGP_CAPCODE_LLGR 71 /* draft-uttaro-idr-bgp-persistence-05 */
227 #define BGP_CAPCODE_RR_CISCO 128
228
229 static const struct tok bgp_capcode_values[] = {
230 { BGP_CAPCODE_MP, "Multiprotocol Extensions"},
231 { BGP_CAPCODE_RR, "Route Refresh"},
232 { BGP_CAPCODE_ORF, "Cooperative Route Filtering"},
233 { BGP_CAPCODE_MR, "Multiple Routes to a Destination"},
234 { BGP_CAPCODE_EXT_NH, "Extended Next Hop Encoding"},
235 { BGP_CAPCODE_ML, "Multiple Labels"},
236 { BGP_CAPCODE_RESTART, "Graceful Restart"},
237 { BGP_CAPCODE_AS_NEW, "32-Bit AS Number"},
238 { BGP_CAPCODE_DYN_CAP, "Dynamic Capability"},
239 { BGP_CAPCODE_MULTISESS, "Multisession BGP"},
240 { BGP_CAPCODE_ADD_PATH, "Multiple Paths"},
241 { BGP_CAPCODE_ENH_RR, "Enhanced Route Refresh"},
242 { BGP_CAPCODE_LLGR, "Long-lived Graceful Restart"},
243 { BGP_CAPCODE_RR_CISCO, "Route Refresh (Cisco)"},
244 { 0, NULL}
245 };
246
247 #define BGP_NOTIFY_MAJOR_MSG 1
248 #define BGP_NOTIFY_MAJOR_OPEN 2
249 #define BGP_NOTIFY_MAJOR_UPDATE 3
250 #define BGP_NOTIFY_MAJOR_HOLDTIME 4
251 #define BGP_NOTIFY_MAJOR_FSM 5
252 #define BGP_NOTIFY_MAJOR_CEASE 6
253 #define BGP_NOTIFY_MAJOR_CAP 7
254
255 static const struct tok bgp_notify_major_values[] = {
256 { BGP_NOTIFY_MAJOR_MSG, "Message Header Error"},
257 { BGP_NOTIFY_MAJOR_OPEN, "OPEN Message Error"},
258 { BGP_NOTIFY_MAJOR_UPDATE, "UPDATE Message Error"},
259 { BGP_NOTIFY_MAJOR_HOLDTIME,"Hold Timer Expired"},
260 { BGP_NOTIFY_MAJOR_FSM, "Finite State Machine Error"},
261 { BGP_NOTIFY_MAJOR_CEASE, "Cease"},
262 { BGP_NOTIFY_MAJOR_CAP, "Capability Message Error"},
263 { 0, NULL}
264 };
265
266 /* draft-ietf-idr-cease-subcode-02 */
267 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
268 /* draft-ietf-idr-shutdown-07 */
269 #define BGP_NOTIFY_MINOR_CEASE_SHUT 2
270 #define BGP_NOTIFY_MINOR_CEASE_RESET 4
271 #define BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN 128
272 static const struct tok bgp_notify_minor_cease_values[] = {
273 { BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
274 { BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
275 { 3, "Peer Unconfigured"},
276 { BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
277 { 5, "Connection Rejected"},
278 { 6, "Other Configuration Change"},
279 { 7, "Connection Collision Resolution"},
280 { 0, NULL}
281 };
282
283 static const struct tok bgp_notify_minor_msg_values[] = {
284 { 1, "Connection Not Synchronized"},
285 { 2, "Bad Message Length"},
286 { 3, "Bad Message Type"},
287 { 0, NULL}
288 };
289
290 static const struct tok bgp_notify_minor_open_values[] = {
291 { 1, "Unsupported Version Number"},
292 { 2, "Bad Peer AS"},
293 { 3, "Bad BGP Identifier"},
294 { 4, "Unsupported Optional Parameter"},
295 { 5, "Authentication Failure"},
296 { 6, "Unacceptable Hold Time"},
297 { 7, "Capability Message Error"},
298 { 0, NULL}
299 };
300
301 static const struct tok bgp_notify_minor_update_values[] = {
302 { 1, "Malformed Attribute List"},
303 { 2, "Unrecognized Well-known Attribute"},
304 { 3, "Missing Well-known Attribute"},
305 { 4, "Attribute Flags Error"},
306 { 5, "Attribute Length Error"},
307 { 6, "Invalid ORIGIN Attribute"},
308 { 7, "AS Routing Loop"},
309 { 8, "Invalid NEXT_HOP Attribute"},
310 { 9, "Optional Attribute Error"},
311 { 10, "Invalid Network Field"},
312 { 11, "Malformed AS_PATH"},
313 { 0, NULL}
314 };
315
316 static const struct tok bgp_notify_minor_fsm_values[] = {
317 { 0, "Unspecified Error"},
318 { 1, "In OpenSent State"},
319 { 2, "In OpenConfirm State"},
320 { 3, "In Established State"},
321 { 0, NULL }
322 };
323
324 static const struct tok bgp_notify_minor_cap_values[] = {
325 { 1, "Invalid Action Value" },
326 { 2, "Invalid Capability Length" },
327 { 3, "Malformed Capability Value" },
328 { 4, "Unsupported Capability Code" },
329 { 0, NULL }
330 };
331
332 static const struct tok bgp_origin_values[] = {
333 { 0, "IGP"},
334 { 1, "EGP"},
335 { 2, "Incomplete"},
336 { 0, NULL}
337 };
338
339 #define BGP_PMSI_TUNNEL_RSVP_P2MP 1
340 #define BGP_PMSI_TUNNEL_LDP_P2MP 2
341 #define BGP_PMSI_TUNNEL_PIM_SSM 3
342 #define BGP_PMSI_TUNNEL_PIM_SM 4
343 #define BGP_PMSI_TUNNEL_PIM_BIDIR 5
344 #define BGP_PMSI_TUNNEL_INGRESS 6
345 #define BGP_PMSI_TUNNEL_LDP_MP2MP 7
346
347 static const struct tok bgp_pmsi_tunnel_values[] = {
348 { BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
349 { BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
350 { BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
351 { BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
352 { BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
353 { BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
354 { BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
355 { 0, NULL}
356 };
357
358 static const struct tok bgp_pmsi_flag_values[] = {
359 { 0x01, "Leaf Information required"},
360 { 0, NULL}
361 };
362
363 #define BGP_AIGP_TLV 1
364
365 static const struct tok bgp_aigp_values[] = {
366 { BGP_AIGP_TLV, "AIGP"},
367 { 0, NULL}
368 };
369
370 /* Subsequent address family identifier, RFC2283 section 7 */
371 #define SAFNUM_RES 0
372 #define SAFNUM_UNICAST 1
373 #define SAFNUM_MULTICAST 2
374 #define SAFNUM_UNIMULTICAST 3 /* deprecated now */
375 /* labeled BGP RFC3107 */
376 #define SAFNUM_LABUNICAST 4
377 /* RFC6514 */
378 #define SAFNUM_MULTICAST_VPN 5
379 /* draft-nalawade-kapoor-tunnel-safi */
380 #define SAFNUM_TUNNEL 64
381 /* RFC4761 */
382 #define SAFNUM_VPLS 65
383 /* RFC6037 */
384 #define SAFNUM_MDT 66
385 /* RFC7432 */
386 #define SAFNUM_EVPN 70
387 /* RFC4364 */
388 #define SAFNUM_VPNUNICAST 128
389 /* RFC6513 */
390 #define SAFNUM_VPNMULTICAST 129
391 #define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
392 /* RFC4684 */
393 #define SAFNUM_RT_ROUTING_INFO 132
394
395 #define BGP_VPN_RD_LEN 8
396
397 static const struct tok bgp_safi_values[] = {
398 { SAFNUM_RES, "Reserved"},
399 { SAFNUM_UNICAST, "Unicast"},
400 { SAFNUM_MULTICAST, "Multicast"},
401 { SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
402 { SAFNUM_LABUNICAST, "labeled Unicast"},
403 { SAFNUM_TUNNEL, "Tunnel"},
404 { SAFNUM_VPLS, "VPLS"},
405 { SAFNUM_MDT, "MDT"},
406 { SAFNUM_EVPN, "EVPN"},
407 { SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
408 { SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
409 { SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
410 { SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
411 { SAFNUM_MULTICAST_VPN, "Multicast VPN"},
412 { 0, NULL }
413 };
414
415 /* well-known community */
416 #define BGP_COMMUNITY_NO_EXPORT 0xffffff01
417 #define BGP_COMMUNITY_NO_ADVERT 0xffffff02
418 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
419
420 /* Extended community type - RFC 4360 */
421 #define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
422 #define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
423 #define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
424 #define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
425 #define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
426 #define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
427 #define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
428 /* rfc2547 bgp-mpls-vpns */
429 #define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
430 #define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
431 #define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
432 #define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
433
434 #define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
435 #define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
436 #define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
437
438 #define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
439 #define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
440
441 #define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
442
443 #define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
444 #define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
445 #define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
446 #define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
447
448 /* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
449 #define BGP_EXT_COM_EIGRP_GEN 0x8800
450 #define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
451 #define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
452 #define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
453 #define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
454 #define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
455
456 static const struct tok bgp_extd_comm_flag_values[] = {
457 { 0x8000, "vendor-specific"},
458 { 0x4000, "non-transitive"},
459 { 0, NULL},
460 };
461
462 static const struct tok bgp_extd_comm_subtype_values[] = {
463 { BGP_EXT_COM_RT_0, "target"},
464 { BGP_EXT_COM_RT_1, "target"},
465 { BGP_EXT_COM_RT_2, "target"},
466 { BGP_EXT_COM_RO_0, "origin"},
467 { BGP_EXT_COM_RO_1, "origin"},
468 { BGP_EXT_COM_RO_2, "origin"},
469 { BGP_EXT_COM_LINKBAND, "link-BW"},
470 { BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
471 { BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
472 { BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
473 { BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
474 { BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
475 { BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
476 { BGP_EXT_COM_ENCAP, "encapsulation"},
477 { BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
478 { BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
479 { BGP_EXT_COM_L2INFO, "layer2-info"},
480 { BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
481 { BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
482 { BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
483 { BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
484 { BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
485 { BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
486 { BGP_EXT_COM_SOURCE_AS, "source-AS" },
487 { BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
488 { BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
489 { BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
490 { 0, NULL},
491 };
492
493 /* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
494 #define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
495 #define BGP_ENCAP_TUNNEL_GRE 2
496 #define BGP_ENCAP_TUNNEL_TRANSMIT 3
497 #define BGP_ENCAP_TUNNEL_IPSEC 4
498 #define BGP_ENCAP_TUNNEL_IP_IPSEC 5
499 #define BGP_ENCAP_TUNNEL_MPLS_IP 6
500 #define BGP_ENCAP_TUNNEL_IP_IP 7
501 #define BGP_ENCAP_TUNNEL_VXLAN 8
502 #define BGP_ENCAP_TUNNEL_NVGRE 9
503 #define BGP_ENCAP_TUNNEL_MPLS 10
504 #define BGP_ENCAP_TUNNEL_MPLS_GRE 11
505 #define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
506 #define BGP_ENCAP_TUNNEL_MPLS_UDP 13
507 #define BGP_ENCAP_TUNNEL_IPV6 14
508 #define BGP_ENCAP_TUNNEL_SR_TE 15
509 #define BGP_ENCAP_TUNNEL_BARE 16
510 #define BGP_ENCAP_TUNNEL_SR 17
511
512 static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
513 { BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
514 { BGP_ENCAP_TUNNEL_GRE, "GRE"},
515 { BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
516 { BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
517 { BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
518 { BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
519 { BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
520 { BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
521 { BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
522 { BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
523 { BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
524 { BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
525 { BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
526 { BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
527 { BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
528 { BGP_ENCAP_TUNNEL_BARE, "Bare"},
529 { BGP_ENCAP_TUNNEL_SR, "SR"},
530 { 0, NULL},
531 };
532
533 /* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
534 #define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
535 #define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
536 #define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
537 #define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
538 #define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
539 #define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
540 #define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
541
542 static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
543 { BGP_OSPF_RTYPE_RTR, "Router" },
544 { BGP_OSPF_RTYPE_NET, "Network" },
545 { BGP_OSPF_RTYPE_SUM, "Summary" },
546 { BGP_OSPF_RTYPE_EXT, "External" },
547 { BGP_OSPF_RTYPE_NSSA,"NSSA External" },
548 { BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
549 { 0, NULL },
550 };
551
552 /* ADD-PATH Send/Receive field values */
553 static const struct tok bgp_add_path_recvsend[] = {
554 { 1, "Receive" },
555 { 2, "Send" },
556 { 3, "Both" },
557 { 0, NULL },
558 };
559
560 /* allocate space for the largest possible string */
561 static char astostr[sizeof("xxxxx.xxxxx")];
562
563 /*
564 * as_printf
565 *
566 * Convert an AS number into a string and return string pointer.
567 *
568 * Depending on bflag is set or not, AS number is converted into ASDOT notation
569 * or plain number notation.
570 *
571 */
572 static char *
573 as_printf(netdissect_options *ndo,
574 char *str, size_t size, u_int asnum)
575 {
576 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
577 snprintf(str, size, "%u", asnum);
578 } else {
579 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
580 }
581 return str;
582 }
583
584 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
585
586 int
587 decode_prefix4(netdissect_options *ndo,
588 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
589 {
590 nd_ipv4 addr;
591 u_int plen, plenbytes;
592
593 ITEMCHECK(1);
594 plen = GET_U_1(pptr);
595 if (32 < plen)
596 return -1;
597 itemlen -= 1;
598
599 memset(&addr, 0, sizeof(addr));
600 plenbytes = (plen + 7) / 8;
601 ND_TCHECK_LEN(pptr + 1, plenbytes);
602 ITEMCHECK(plenbytes);
603 memcpy(&addr, pptr + 1, plenbytes);
604 if (plen % 8) {
605 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
606 }
607 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
608 return 1 + plenbytes;
609
610 trunc:
611 return -2;
612
613 badtlv:
614 return -3;
615 }
616
617 static int
618 decode_labeled_prefix4(netdissect_options *ndo,
619 const u_char *pptr, u_int itemlen, char *buf,
620 size_t buflen)
621 {
622 nd_ipv4 addr;
623 u_int plen, plenbytes;
624
625 /* prefix length and label = 4 bytes */
626 ND_TCHECK_4(pptr);
627 ITEMCHECK(4);
628 plen = GET_U_1(pptr); /* get prefix length */
629
630 /* this is one of the weirdnesses of rfc3107
631 the label length (actually the label + COS bits)
632 is added to the prefix length;
633 we also do only read out just one label -
634 there is no real application for advertisement of
635 stacked labels in a single BGP message
636 */
637
638 if (24 > plen)
639 return -1;
640
641 plen-=24; /* adjust prefixlen - labellength */
642
643 if (32 < plen)
644 return -1;
645 itemlen -= 4;
646
647 memset(&addr, 0, sizeof(addr));
648 plenbytes = (plen + 7) / 8;
649 ND_TCHECK_LEN(pptr + 4, plenbytes);
650 ITEMCHECK(plenbytes);
651 memcpy(&addr, pptr + 4, plenbytes);
652 if (plen % 8) {
653 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
654 }
655 /* the label may get offsetted by 4 bits so lets shift it right */
656 snprintf(buf, buflen, "%s/%u, label:%u %s",
657 ipaddr_string(ndo, (const u_char *)&addr),
658 plen,
659 GET_BE_U_3(pptr + 1)>>4,
660 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
661
662 return 4 + plenbytes;
663
664 trunc:
665 return -2;
666
667 badtlv:
668 return -3;
669 }
670
671 /*
672 * bgp_vpn_ip_print
673 *
674 * print an ipv4 or ipv6 address into a buffer dependend on address length.
675 */
676 static char *
677 bgp_vpn_ip_print(netdissect_options *ndo,
678 const u_char *pptr, u_int addr_length)
679 {
680
681 /* worst case string is s fully formatted v6 address */
682 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
683 char *pos = addr;
684
685 switch(addr_length) {
686 case (sizeof(nd_ipv4) << 3): /* 32 */
687 ND_TCHECK_LEN(pptr, sizeof(nd_ipv4));
688 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
689 break;
690 case (sizeof(nd_ipv6) << 3): /* 128 */
691 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
692 break;
693 default:
694 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
695 break;
696 }
697 pos += strlen(pos);
698
699 trunc:
700 *(pos) = '\0';
701 return (addr);
702 }
703
704 /*
705 * bgp_vpn_sg_print
706 *
707 * print an multicast s,g entry into a buffer.
708 * the s,g entry is encoded like this.
709 *
710 * +-----------------------------------+
711 * | Multicast Source Length (1 octet) |
712 * +-----------------------------------+
713 * | Multicast Source (Variable) |
714 * +-----------------------------------+
715 * | Multicast Group Length (1 octet) |
716 * +-----------------------------------+
717 * | Multicast Group (Variable) |
718 * +-----------------------------------+
719 *
720 * return the number of bytes read from the wire.
721 */
722 static u_int
723 bgp_vpn_sg_print(netdissect_options *ndo,
724 const u_char *pptr, char *buf, size_t buflen)
725 {
726 uint8_t addr_length;
727 u_int total_length, offset;
728
729 total_length = 0;
730
731 /* Source address length, encoded in bits */
732 addr_length = GET_U_1(pptr);
733 pptr++;
734
735 /* Source address */
736 ND_TCHECK_LEN(pptr, (addr_length >> 3));
737 total_length += (addr_length >> 3) + 1;
738 offset = (u_int)strlen(buf);
739 if (addr_length) {
740 snprintf(buf + offset, buflen - offset, ", Source %s",
741 bgp_vpn_ip_print(ndo, pptr, addr_length));
742 pptr += (addr_length >> 3);
743 }
744
745 /* Group address length, encoded in bits */
746 addr_length = GET_U_1(pptr);
747 pptr++;
748
749 /* Group address */
750 ND_TCHECK_LEN(pptr, (addr_length >> 3));
751 total_length += (addr_length >> 3) + 1;
752 offset = (u_int)strlen(buf);
753 if (addr_length) {
754 snprintf(buf + offset, buflen - offset, ", Group %s",
755 bgp_vpn_ip_print(ndo, pptr, addr_length));
756 pptr += (addr_length >> 3);
757 }
758
759 trunc:
760 return (total_length);
761 }
762
763 /* Print an RFC 4364 Route Distinguisher */
764 const char *
765 bgp_vpn_rd_print(netdissect_options *ndo,
766 const u_char *pptr)
767 {
768 /* allocate space for the largest possible string */
769 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
770 char *pos = rd;
771
772 /* ok lets load the RD format */
773 switch (GET_BE_U_2(pptr)) {
774
775 case 0:
776 /* 2-byte-AS:number fmt */
777 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
778 GET_BE_U_2(pptr + 2),
779 GET_BE_U_4(pptr + 4),
780 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
781 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
782 break;
783
784 case 1:
785 /* IP-address:AS fmt */
786 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
787 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
788 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
789 GET_BE_U_2(pptr + 6));
790 break;
791
792 case 2:
793 /* 4-byte-AS:number fmt */
794 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
795 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
796 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
797 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
798 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
799 break;
800 default:
801 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
802 break;
803 }
804 pos += strlen(pos);
805 *(pos) = '\0';
806 return (rd);
807 }
808
809 /*
810 * Print an RFC 4360 Extended Community.
811 */
812 static void
813 bgp_extended_community_print(netdissect_options *ndo,
814 const u_char *pptr)
815 {
816 union { /* copy buffer for bandwidth values */
817 float f;
818 uint32_t i;
819 } bw;
820
821 switch (GET_BE_U_2(pptr)) {
822
823 case BGP_EXT_COM_RT_0:
824 case BGP_EXT_COM_RO_0:
825 case BGP_EXT_COM_L2VPN_RT_0:
826 ND_PRINT("%u:%u (= %s)",
827 GET_BE_U_2(pptr + 2),
828 GET_BE_U_4(pptr + 4),
829 GET_IPADDR_STRING(pptr+4));
830 break;
831
832 case BGP_EXT_COM_RT_1:
833 case BGP_EXT_COM_RO_1:
834 case BGP_EXT_COM_L2VPN_RT_1:
835 case BGP_EXT_COM_VRF_RT_IMP:
836 ND_PRINT("%s:%u",
837 GET_IPADDR_STRING(pptr+2),
838 GET_BE_U_2(pptr + 6));
839 break;
840
841 case BGP_EXT_COM_RT_2:
842 case BGP_EXT_COM_RO_2:
843 ND_PRINT("%s:%u",
844 as_printf(ndo, astostr, sizeof(astostr),
845 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
846 break;
847
848 case BGP_EXT_COM_LINKBAND:
849 bw.i = GET_BE_U_4(pptr + 2);
850 ND_PRINT("bandwidth: %.3f Mbps",
851 bw.f*8/1000000);
852 break;
853
854 case BGP_EXT_COM_VPN_ORIGIN:
855 case BGP_EXT_COM_VPN_ORIGIN2:
856 case BGP_EXT_COM_VPN_ORIGIN3:
857 case BGP_EXT_COM_VPN_ORIGIN4:
858 case BGP_EXT_COM_OSPF_RID:
859 case BGP_EXT_COM_OSPF_RID2:
860 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
861 break;
862
863 case BGP_EXT_COM_OSPF_RTYPE:
864 case BGP_EXT_COM_OSPF_RTYPE2:
865 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
866 GET_IPADDR_STRING(pptr+2),
867 tok2str(bgp_extd_comm_ospf_rtype_values,
868 "unknown (0x%02x)",
869 GET_U_1((pptr + 6))),
870 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
871 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
872 break;
873
874 case BGP_EXT_COM_L2INFO:
875 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
876 tok2str(l2vpn_encaps_values,
877 "unknown encaps",
878 GET_U_1((pptr + 2))),
879 GET_U_1((pptr + 3)),
880 GET_BE_U_2(pptr + 4));
881 break;
882
883 case BGP_EXT_COM_SOURCE_AS:
884 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
885 break;
886
887 case BGP_EXT_COM_ENCAP:
888 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
889 "unknown encaps",
890 GET_BE_U_2(pptr + 6)));
891 break;
892
893 default:
894 ND_PRINT("%02x%02x%02x%02x%02x%02x",
895 GET_U_1(pptr + 2),
896 GET_U_1(pptr + 3),
897 GET_U_1(pptr + 4),
898 GET_U_1(pptr + 5),
899 GET_U_1(pptr + 6),
900 GET_U_1(pptr + 7));
901 break;
902 }
903 }
904
905 /*
906 * RFC4684 (Section 4)/RFC2858 (Section 4).
907 * RTC membership prefix is structured as follows
908 * [prefix-len] [origin-as] [route-target]
909 * The route-target is encoded as RT ext-comms.
910 * Prefix-len may be 0, 32..96
911 *
912 * Note that pptr is not packet data - it is
913 * a buffer owned by our caller - therefore GET_*
914 * macros can not be used.
915 */
916 static char *
917 bgp_rt_prefix_print(netdissect_options *ndo,
918 const u_char *pptr,
919 u_int plen)
920 {
921 /* allocate space for the largest possible string */
922 char rtc_prefix_in_hex[20] = "";
923 u_int rtc_prefix_in_hex_len = 0;
924 static char output[61]; /* max response string */
925 uint16_t ec_type = 0;
926 u_int octet_count;
927 u_int i;
928
929 if (plen == 0) {
930 snprintf(output, sizeof(output), "route-target: 0:0/0");
931 return (output);
932 }
933
934 /* hex representation of the prefix */
935 octet_count = (plen+7)/8;
936 for (i=0; i<octet_count; i++) {
937 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
938 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
939 "%02x%s", *(pptr+i),
940 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
941 }
942
943 if (plen < 16) {
944 /*
945 * The prefix is too short to include the full ext-comm type,
946 * so we have no way to parse it further.
947 */
948 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
949 rtc_prefix_in_hex, plen);
950 return (output);
951 }
952
953 /*
954 * get the ext-comm type
955 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
956 * hense EXTRACT_*() macros are safe.
957 */
958 ec_type = EXTRACT_BE_U_2(pptr);
959 switch (ec_type) {
960 case BGP_EXT_COM_RT_0:
961 /* 2-byte-AS:number fmt */
962 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
963 EXTRACT_BE_U_2(pptr+2),
964 EXTRACT_BE_U_4(pptr+4),
965 plen, rtc_prefix_in_hex);
966 break;
967
968 case BGP_EXT_COM_RT_1:
969 /* IP-address:AS fmt */
970 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
971 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
972 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
973 break;
974
975 case BGP_EXT_COM_RT_2:
976 /* 4-byte-AS:number fmt */
977 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
978 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
979 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
980 break;
981
982 default:
983 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
984 ec_type,
985 rtc_prefix_in_hex, plen);
986 break;
987 }
988 return (output);
989 }
990
991 /* RFC 4684 */
992 static int
993 decode_rt_routing_info(netdissect_options *ndo,
994 const u_char *pptr)
995 {
996 uint8_t route_target[8];
997 u_int plen;
998 char asbuf[sizeof(astostr)]; /* bgp_vpn_rd_print() overwrites astostr */
999 u_int num_octets;
1000
1001 /* NLRI "prefix length" from RFC 2858 Section 4. */
1002 plen = GET_U_1(pptr); /* get prefix length */
1003
1004 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1005 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1006 * target" fields inside the "prefix" depending on its length.
1007 */
1008 if (0 == plen) {
1009 /* Without "origin AS", without "route target". */
1010 ND_PRINT("\n\t default route target");
1011 return 1;
1012 }
1013
1014 if (32 > plen) {
1015 ND_PRINT("\n\t (illegal prefix length)");
1016 return -1;
1017 }
1018
1019 /* With at least "origin AS", possibly with "route target". */
1020 as_printf(ndo, asbuf, sizeof(asbuf), GET_BE_U_4(pptr + 1));
1021
1022 plen -= 32; /* adjust prefix length */
1023
1024 if (64 < plen) {
1025 ND_PRINT("\n\t (illegal prefix length)");
1026 return -1;
1027 }
1028
1029 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1030 * and gives the number of octets in the variable-length "route
1031 * target" field inside this NLRI "prefix". Look for it.
1032 */
1033 memset(&route_target, 0, sizeof(route_target));
1034 num_octets = (plen + 7) / 8;
1035 ND_TCHECK_LEN(pptr + 5, num_octets);
1036 memcpy(&route_target, pptr + 5, num_octets);
1037 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1038 if (plen % 8) {
1039 ((u_char *)&route_target)[num_octets - 1] &=
1040 ((0xff00 >> (plen % 8)) & 0xff);
1041 }
1042 ND_PRINT("\n\t origin AS: %s, %s",
1043 asbuf,
1044 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1045
1046 return 5 + num_octets;
1047 trunc:
1048 return -2;
1049 }
1050
1051 static int
1052 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1053 const u_char *pptr, char *buf, size_t buflen)
1054 {
1055 nd_ipv4 addr;
1056 u_int plen;
1057
1058 plen = GET_U_1(pptr); /* get prefix length */
1059
1060 if ((24+64) > plen)
1061 return -1;
1062
1063 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1064
1065 if (32 < plen)
1066 return -1;
1067
1068 memset(&addr, 0, sizeof(addr));
1069 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1070 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1071 if (plen % 8) {
1072 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1073 ((0xff00 >> (plen % 8)) & 0xff);
1074 }
1075 /* the label may get offsetted by 4 bits so lets shift it right */
1076 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1077 bgp_vpn_rd_print(ndo, pptr+4),
1078 ipaddr_string(ndo, (const u_char *)&addr),
1079 plen,
1080 GET_BE_U_3(pptr + 1)>>4,
1081 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1082
1083 return 12 + (plen + 7) / 8;
1084
1085 trunc:
1086 return -2;
1087 }
1088
1089 /*
1090 * +-------------------------------+
1091 * | |
1092 * | RD:IPv4-address (12 octets) |
1093 * | |
1094 * +-------------------------------+
1095 * | MDT Group-address (4 octets) |
1096 * +-------------------------------+
1097 */
1098
1099 #define MDT_VPN_NLRI_LEN 16
1100
1101 static int
1102 decode_mdt_vpn_nlri(netdissect_options *ndo,
1103 const u_char *pptr, char *buf, size_t buflen)
1104 {
1105 const u_char *rd;
1106 const u_char *vpn_ip;
1107
1108 /* if the NLRI is not predefined length, quit.*/
1109 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1110 return -1;
1111 pptr++;
1112
1113 /* RD */
1114 ND_TCHECK_8(pptr);
1115 rd = pptr;
1116 pptr += 8;
1117
1118 /* IPv4 address */
1119 ND_TCHECK_LEN(pptr, sizeof(nd_ipv4));
1120 vpn_ip = pptr;
1121 pptr += sizeof(nd_ipv4);
1122
1123 /* MDT Group Address */
1124 ND_TCHECK_LEN(pptr, sizeof(nd_ipv4));
1125
1126 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1127 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1128
1129 return MDT_VPN_NLRI_LEN + 1;
1130
1131 trunc:
1132 return -2;
1133 }
1134
1135 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1136 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1137 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1138 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1139 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1140 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1141 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1142
1143 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1144 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1145 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1146 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1147 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1148 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1149 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1150 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1151 { 0, NULL}
1152 };
1153
1154 static int
1155 decode_multicast_vpn(netdissect_options *ndo,
1156 const u_char *pptr, char *buf, size_t buflen)
1157 {
1158 uint8_t route_type, route_length;
1159 u_int addr_length, sg_length;
1160 u_int offset;
1161
1162 ND_TCHECK_2(pptr);
1163 route_type = GET_U_1(pptr);
1164 pptr++;
1165 route_length = GET_U_1(pptr);
1166 pptr++;
1167
1168 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1169 tok2str(bgp_multicast_vpn_route_type_values,
1170 "Unknown", route_type),
1171 route_type, route_length);
1172
1173 switch(route_type) {
1174 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1175 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1176 offset = (u_int)strlen(buf);
1177 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1178 bgp_vpn_rd_print(ndo, pptr),
1179 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1180 (route_length - BGP_VPN_RD_LEN) << 3));
1181 break;
1182 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1183 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1184 offset = (u_int)strlen(buf);
1185 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1186 bgp_vpn_rd_print(ndo, pptr),
1187 as_printf(ndo, astostr, sizeof(astostr),
1188 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1189 break;
1190
1191 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1192 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1193 offset = (u_int)strlen(buf);
1194 snprintf(buf + offset, buflen - offset, ", RD: %s",
1195 bgp_vpn_rd_print(ndo, pptr));
1196 pptr += BGP_VPN_RD_LEN;
1197
1198 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1199 addr_length = route_length - sg_length;
1200
1201 ND_TCHECK_LEN(pptr, addr_length);
1202 offset = (u_int)strlen(buf);
1203 snprintf(buf + offset, buflen - offset, ", Originator %s",
1204 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1205 break;
1206
1207 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1208 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1209 offset = (u_int)strlen(buf);
1210 snprintf(buf + offset, buflen - offset, ", RD: %s",
1211 bgp_vpn_rd_print(ndo, pptr));
1212 pptr += BGP_VPN_RD_LEN;
1213
1214 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1215 break;
1216
1217 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1218 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1219 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1220 offset = (u_int)strlen(buf);
1221 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1222 bgp_vpn_rd_print(ndo, pptr),
1223 as_printf(ndo, astostr, sizeof(astostr),
1224 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1225 pptr += BGP_VPN_RD_LEN + 4;
1226
1227 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1228 break;
1229
1230 /*
1231 * no per route-type printing yet.
1232 */
1233 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1234 default:
1235 break;
1236 }
1237
1238 return route_length + 2;
1239
1240 trunc:
1241 return -2;
1242 }
1243
1244 /*
1245 * As I remember, some versions of systems have an snprintf() that
1246 * returns -1 if the buffer would have overflowed. If the return
1247 * value is negative, set buflen to 0, to indicate that we've filled
1248 * the buffer up.
1249 *
1250 * If the return value is greater than buflen, that means that
1251 * the buffer would have overflowed; again, set buflen to 0 in
1252 * that case.
1253 */
1254 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1255 if (stringlen<0) \
1256 buflen=0; \
1257 else if ((u_int)stringlen>buflen) \
1258 buflen=0; \
1259 else { \
1260 buflen-=stringlen; \
1261 buf+=stringlen; \
1262 }
1263
1264 static int
1265 decode_labeled_vpn_l2(netdissect_options *ndo,
1266 const u_char *pptr, char *buf, size_t buflen)
1267 {
1268 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1269 int stringlen;
1270
1271 plen = GET_BE_U_2(pptr);
1272 tlen = plen;
1273 pptr += 2;
1274 /* Old and new L2VPN NLRI share AFI/SAFI
1275 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1276 * and > 17 as old format. Complain for the middle case
1277 */
1278 if (plen == 12) {
1279 /* assume AD-only with RD, BGPNH */
1280 ND_TCHECK_LEN(pptr, 12);
1281 buf[0] = '\0';
1282 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1283 bgp_vpn_rd_print(ndo, pptr),
1284 GET_IPADDR_STRING(pptr+8));
1285 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1286 pptr += 12;
1287 tlen -= 12;
1288 return plen + 2;
1289 } else if (plen > 17) {
1290 /* assume old format */
1291 /* RD, ID, LBLKOFF, LBLBASE */
1292
1293 ND_TCHECK_LEN(pptr, 15);
1294 buf[0] = '\0';
1295 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1296 bgp_vpn_rd_print(ndo, pptr),
1297 GET_BE_U_2(pptr + 8),
1298 GET_BE_U_2(pptr + 10),
1299 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1300 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1301 pptr += 15;
1302 tlen -= 15;
1303
1304 /* ok now the variable part - lets read out TLVs*/
1305 while (tlen != 0) {
1306 if (tlen < 3) {
1307 if (buflen != 0) {
1308 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1309 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1310 }
1311 return plen + 2;
1312 }
1313 ND_TCHECK_3(pptr);
1314 tlv_type = GET_U_1(pptr);
1315 pptr++;
1316 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1317 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1318 pptr += 2;
1319
1320 switch(tlv_type) {
1321 case 1:
1322 if (buflen != 0) {
1323 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1324 tlv_type,
1325 tlv_len);
1326 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1327 }
1328 while (ttlv_len != 0) {
1329 if (tlen < 1) {
1330 if (buflen != 0) {
1331 stringlen=snprintf(buf,buflen, " (ran past the end)");
1332 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1333 }
1334 return plen + 2;
1335 }
1336 ND_TCHECK_1(pptr);
1337 if (buflen != 0) {
1338 stringlen=snprintf(buf,buflen, "%02x",
1339 GET_U_1(pptr));
1340 pptr++;
1341 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1342 }
1343 ttlv_len--;
1344 tlen--;
1345 }
1346 break;
1347 default:
1348 if (buflen != 0) {
1349 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1350 tlv_type,
1351 tlv_len);
1352 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1353 }
1354 if (tlen < ttlv_len) {
1355 if (buflen != 0) {
1356 stringlen=snprintf(buf,buflen, " (ran past the end)");
1357 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1358 }
1359 return plen + 2;
1360 }
1361 tlen -= ttlv_len;
1362 break;
1363 }
1364 }
1365 return plen + 2;
1366 } else {
1367 /* complain bitterly ? */
1368 /* fall through */
1369 goto trunc;
1370 }
1371
1372 trunc:
1373 return -2;
1374 }
1375
1376 int
1377 decode_prefix6(netdissect_options *ndo,
1378 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1379 {
1380 nd_ipv6 addr;
1381 u_int plen, plenbytes;
1382
1383 ITEMCHECK(1);
1384 plen = GET_U_1(pd);
1385 if (128 < plen)
1386 return -1;
1387 itemlen -= 1;
1388
1389 memset(&addr, 0, sizeof(addr));
1390 plenbytes = (plen + 7) / 8;
1391 ND_TCHECK_LEN(pd + 1, plenbytes);
1392 ITEMCHECK(plenbytes);
1393 memcpy(&addr, pd + 1, plenbytes);
1394 if (plen % 8) {
1395 addr[plenbytes - 1] &=
1396 ((0xff00 >> (plen % 8)) & 0xff);
1397 }
1398 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1399 return 1 + plenbytes;
1400
1401 trunc:
1402 return -2;
1403
1404 badtlv:
1405 return -3;
1406 }
1407
1408 static int
1409 decode_labeled_prefix6(netdissect_options *ndo,
1410 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1411 {
1412 nd_ipv6 addr;
1413 u_int plen, plenbytes;
1414
1415 /* prefix length and label = 4 bytes */
1416 ND_TCHECK_4(pptr);
1417 ITEMCHECK(4);
1418 plen = GET_U_1(pptr); /* get prefix length */
1419
1420 if (24 > plen)
1421 return -1;
1422
1423 plen -= 24; /* adjust prefixlen - labellength */
1424
1425 if (128 < plen)
1426 return -1;
1427 itemlen -= 4;
1428
1429 memset(&addr, 0, sizeof(addr));
1430 plenbytes = (plen + 7) / 8;
1431 ND_TCHECK_LEN(pptr + 4, plenbytes);
1432 memcpy(&addr, pptr + 4, plenbytes);
1433 if (plen % 8) {
1434 addr[plenbytes - 1] &=
1435 ((0xff00 >> (plen % 8)) & 0xff);
1436 }
1437 /* the label may get offsetted by 4 bits so lets shift it right */
1438 snprintf(buf, buflen, "%s/%u, label:%u %s",
1439 ip6addr_string(ndo, (const u_char *)&addr),
1440 plen,
1441 GET_BE_U_3(pptr + 1)>>4,
1442 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1443
1444 return 4 + plenbytes;
1445
1446 trunc:
1447 return -2;
1448
1449 badtlv:
1450 return -3;
1451 }
1452
1453 static int
1454 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1455 const u_char *pptr, char *buf, size_t buflen)
1456 {
1457 nd_ipv6 addr;
1458 u_int plen;
1459
1460 plen = GET_U_1(pptr); /* get prefix length */
1461
1462 if ((24+64) > plen)
1463 return -1;
1464
1465 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1466
1467 if (128 < plen)
1468 return -1;
1469
1470 memset(&addr, 0, sizeof(addr));
1471 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1472 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1473 if (plen % 8) {
1474 addr[(plen + 7) / 8 - 1] &=
1475 ((0xff00 >> (plen % 8)) & 0xff);
1476 }
1477 /* the label may get offsetted by 4 bits so lets shift it right */
1478 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1479 bgp_vpn_rd_print(ndo, pptr+4),
1480 ip6addr_string(ndo, (const u_char *)&addr),
1481 plen,
1482 GET_BE_U_3(pptr + 1)>>4,
1483 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1484
1485 return 12 + (plen + 7) / 8;
1486
1487 trunc:
1488 return -2;
1489 }
1490
1491 static int
1492 decode_clnp_prefix(netdissect_options *ndo,
1493 const u_char *pptr, char *buf, size_t buflen)
1494 {
1495 uint8_t addr[19];
1496 u_int plen;
1497
1498 plen = GET_U_1(pptr); /* get prefix length */
1499
1500 if (152 < plen)
1501 return -1;
1502
1503 memset(&addr, 0, sizeof(addr));
1504 ND_TCHECK_LEN(pptr + 4, (plen + 7) / 8);
1505 memcpy(&addr, pptr + 4, (plen + 7) / 8);
1506 if (plen % 8) {
1507 addr[(plen + 7) / 8 - 1] &=
1508 ((0xff00 >> (plen % 8)) & 0xff);
1509 }
1510 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1511 snprintf(buf, buflen, "%s/%u",
1512 isonsap_string(ndo, addr,(plen + 7) / 8),
1513 plen);
1514
1515 return 1 + (plen + 7) / 8;
1516
1517 trunc:
1518 return -2;
1519 }
1520
1521 static int
1522 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1523 const u_char *pptr, char *buf, size_t buflen)
1524 {
1525 uint8_t addr[19];
1526 u_int plen;
1527
1528 plen = GET_U_1(pptr); /* get prefix length */
1529
1530 if ((24+64) > plen)
1531 return -1;
1532
1533 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1534
1535 if (152 < plen)
1536 return -1;
1537
1538 memset(&addr, 0, sizeof(addr));
1539 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1540 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1541 if (plen % 8) {
1542 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1543 }
1544 /* the label may get offsetted by 4 bits so lets shift it right */
1545 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1546 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1547 bgp_vpn_rd_print(ndo, pptr+4),
1548 isonsap_string(ndo, addr,(plen + 7) / 8),
1549 plen,
1550 GET_BE_U_3(pptr + 1)>>4,
1551 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1552
1553 return 12 + (plen + 7) / 8;
1554
1555 trunc:
1556 return -2;
1557 }
1558
1559 /*
1560 * bgp_attr_get_as_size
1561 *
1562 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1563 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1564 * support, exchange AS-Path with the same path-attribute type value 0x02.
1565 */
1566 static u_int
1567 bgp_attr_get_as_size(netdissect_options *ndo,
1568 uint8_t bgpa_type, const u_char *pptr, u_int len)
1569 {
1570 const u_char *tptr = pptr;
1571
1572 /*
1573 * If the path attribute is the optional AS4 path type, then we already
1574 * know, that ASs must be encoded in 4 byte format.
1575 */
1576 if (bgpa_type == BGPTYPE_AS4_PATH) {
1577 return 4;
1578 }
1579
1580 /*
1581 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1582 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1583 * each.
1584 */
1585 while (tptr < pptr + len) {
1586 ND_TCHECK_1(tptr);
1587
1588 /*
1589 * If we do not find a valid segment type, our guess might be wrong.
1590 */
1591 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1592 goto trunc;
1593 }
1594 tptr += 2 + GET_U_1(tptr + 1) * 2;
1595 }
1596
1597 /*
1598 * If we correctly reached end of the AS path attribute data content,
1599 * then most likely ASs were indeed encoded as 2 bytes.
1600 */
1601 if (tptr == pptr + len) {
1602 return 2;
1603 }
1604
1605 trunc:
1606
1607 /*
1608 * We can come here, either we did not have enough data, or if we
1609 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1610 * so that calller can try to decode each AS as of 4 bytes. If indeed
1611 * there was not enough data, it will crib and end the parse anyways.
1612 */
1613 return 4;
1614 }
1615
1616 /*
1617 * The only way to know that a BGP UPDATE message is using add path is
1618 * by checking if the capability is in the OPEN message which we may have missed.
1619 * So this function checks if it is possible that the update could contain add path
1620 * and if so it checks that standard BGP doesn't make sense.
1621 */
1622 static int
1623 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1624 u_int max_prefix_length)
1625 {
1626 u_int offset, prefix_length;
1627
1628 if (length < 5) {
1629 return 0;
1630 }
1631
1632 /*
1633 * Scan through the NLRI information under the assumpetion that
1634 * it doesn't have path IDs.
1635 */
1636 for (offset = 0; offset < length;) {
1637 offset += 4;
1638 if (!ND_TTEST_1(pptr + offset)) {
1639 /* We ran out of captured data; quit scanning. */
1640 break;
1641 }
1642 prefix_length = GET_U_1(pptr + offset);
1643 /*
1644 * Add 4 to cover the path id
1645 * and check the prefix length isn't greater than 32/128.
1646 */
1647 if (prefix_length > max_prefix_length) {
1648 return 0;
1649 }
1650 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1651 offset += 1 + ((prefix_length + 7) / 8);
1652 }
1653 /* check we haven't gone past the end of the section */
1654 if (offset > length) {
1655 return 0;
1656 }
1657
1658 /* check it's not standard BGP */
1659 for (offset = 0; offset < length; ) {
1660 if (!ND_TTEST_1(pptr + offset)) {
1661 /* We ran out of captured data; quit scanning. */
1662 break;
1663 }
1664 prefix_length = GET_U_1(pptr + offset);
1665 /*
1666 * If the prefix_length is zero (0.0.0.0/0)
1667 * and since it's not the only address (length >= 5)
1668 * then it is add-path
1669 */
1670 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1671 return 1;
1672 }
1673 offset += 1 + ((prefix_length + 7) / 8);
1674 }
1675 if (offset > length) {
1676 return 1;
1677 }
1678
1679 /* assume not add-path by default */
1680 return 0;
1681 }
1682
1683 static int
1684 bgp_mp_af_print(netdissect_options *ndo,
1685 const u_char *tptr, u_int tlen,
1686 uint16_t *afp, uint8_t *safip)
1687 {
1688 uint16_t af;
1689 uint8_t safi;
1690
1691 af = GET_BE_U_2(tptr);
1692 *afp = af;
1693 safi = GET_U_1(tptr + 2);
1694 *safip = safi;
1695
1696 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1697 tok2str(af_values, "Unknown AFI", af),
1698 af,
1699 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1700 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1701 safi);
1702
1703 switch(af<<8 | safi) {
1704 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1705 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1706 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1707 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1708 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1709 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1710 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1711 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1712 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1713 case (AFNUM_INET<<8 | SAFNUM_MDT):
1714 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1715 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1716 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1717 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1718 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1719 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1720 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1721 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1722 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1723 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1724 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1725 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1726 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1727 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1728 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1729 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1730 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1731 break;
1732 default:
1733 ND_TCHECK_LEN(tptr, tlen);
1734 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1735 if (ndo->ndo_vflag <= 1)
1736 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1737 return -1;
1738 }
1739 return 0;
1740 trunc:
1741 return -2;
1742 }
1743
1744 static int
1745 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1746 const u_char *tptr, u_int len,
1747 char *buf, size_t buflen,
1748 int add_path4, int add_path6)
1749 {
1750 int advance;
1751 u_int path_id = 0;
1752
1753 switch (af<<8 | safi) {
1754 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1755 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1756 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1757 if (add_path4) {
1758 path_id = GET_BE_U_4(tptr);
1759 tptr += 4;
1760 }
1761 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1762 if (advance == -1)
1763 ND_PRINT("\n\t (illegal prefix length)");
1764 else if (advance == -2)
1765 goto trunc;
1766 else if (advance == -3)
1767 break; /* bytes left, but not enough */
1768 else
1769 ND_PRINT("\n\t %s", buf);
1770 if (add_path4) {
1771 ND_PRINT(" Path Id: %u", path_id);
1772 advance += 4;
1773 }
1774 break;
1775 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1776 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1777 if (advance == -1)
1778 ND_PRINT("\n\t (illegal prefix length)");
1779 else if (advance == -2)
1780 goto trunc;
1781 else if (advance == -3)
1782 break; /* bytes left, but not enough */
1783 else
1784 ND_PRINT("\n\t %s", buf);
1785 break;
1786 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1787 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1788 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1789 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1790 if (advance == -1)
1791 ND_PRINT("\n\t (illegal prefix length)");
1792 else if (advance == -2)
1793 goto trunc;
1794 else
1795 ND_PRINT("\n\t %s", buf);
1796 break;
1797 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1798 advance = decode_rt_routing_info(ndo, tptr);
1799 if (advance == -2)
1800 goto trunc;
1801 break;
1802 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1803 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1804 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1805 if (advance == -1)
1806 ND_PRINT("\n\t (illegal prefix length)");
1807 else if (advance == -2)
1808 goto trunc;
1809 else
1810 ND_PRINT("\n\t %s", buf);
1811 break;
1812
1813 case (AFNUM_INET<<8 | SAFNUM_MDT):
1814 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1815 if (advance == -1)
1816 ND_PRINT("\n\t (illegal prefix length)");
1817 else if (advance == -2)
1818 goto trunc;
1819 else
1820 ND_PRINT("\n\t %s", buf);
1821 break;
1822 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1823 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1824 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1825 if (add_path6) {
1826 path_id = GET_BE_U_4(tptr);
1827 tptr += 4;
1828 }
1829 advance = decode_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 if (add_path6) {
1839 ND_PRINT(" Path Id: %u", path_id);
1840 advance += 4;
1841 }
1842 break;
1843 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1844 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1845 if (advance == -1)
1846 ND_PRINT("\n\t (illegal prefix length)");
1847 else if (advance == -2)
1848 goto trunc;
1849 else if (advance == -3)
1850 break; /* bytes left, but not enough */
1851 else
1852 ND_PRINT("\n\t %s", buf);
1853 break;
1854 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1855 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1856 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1857 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1858 if (advance == -1)
1859 ND_PRINT("\n\t (illegal prefix length)");
1860 else if (advance == -2)
1861 goto trunc;
1862 else
1863 ND_PRINT("\n\t %s", buf);
1864 break;
1865 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1866 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1867 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1868 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1869 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1870 if (advance == -1)
1871 ND_PRINT("\n\t (illegal length)");
1872 else if (advance == -2)
1873 goto trunc;
1874 else
1875 ND_PRINT("\n\t %s", buf);
1876 break;
1877 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1878 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1879 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1880 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1881 if (advance == -1)
1882 ND_PRINT("\n\t (illegal prefix length)");
1883 else if (advance == -2)
1884 goto trunc;
1885 else
1886 ND_PRINT("\n\t %s", buf);
1887 break;
1888 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1889 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1890 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1891 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1892 if (advance == -1)
1893 ND_PRINT("\n\t (illegal prefix length)");
1894 else if (advance == -2)
1895 goto trunc;
1896 else
1897 ND_PRINT("\n\t %s", buf);
1898 break;
1899 default:
1900 /*
1901 * This should not happen, we should have been protected
1902 * by bgp_mp_af_print()'s return value.
1903 */
1904 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1905 advance = -4;
1906 break;
1907 }
1908 return advance;
1909 trunc: /* we rely on the caller to recognize -2 return value */
1910 return -2;
1911 }
1912
1913 static int
1914 bgp_attr_print(netdissect_options *ndo,
1915 uint8_t atype, const u_char *pptr, u_int len,
1916 const unsigned attr_set_level)
1917 {
1918 u_int i;
1919 uint16_t af;
1920 uint8_t safi, snpa, nhlen;
1921 int advance;
1922 u_int tlen;
1923 const u_char *tptr;
1924 char buf[MAXHOSTNAMELEN + 100];
1925 u_int as_size;
1926 int add_path4, add_path6;
1927 int ret;
1928
1929 tptr = pptr;
1930 tlen = len;
1931
1932 switch (atype) {
1933 case BGPTYPE_ORIGIN:
1934 if (len != 1)
1935 ND_PRINT("invalid len");
1936 else {
1937 ND_PRINT("%s", tok2str(bgp_origin_values,
1938 "Unknown Origin Typecode",
1939 GET_U_1(tptr)));
1940 }
1941 break;
1942
1943 /*
1944 * Process AS4 byte path and AS2 byte path attributes here.
1945 */
1946 case BGPTYPE_AS4_PATH:
1947 case BGPTYPE_AS_PATH:
1948 if (len % 2) {
1949 ND_PRINT("invalid len");
1950 break;
1951 }
1952 if (!len) {
1953 ND_PRINT("empty");
1954 break;
1955 }
1956
1957 /*
1958 * BGP updates exchanged between New speakers that support 4
1959 * byte AS, ASs are always encoded in 4 bytes. There is no
1960 * definitive way to find this, just by the packet's
1961 * contents. So, check for packet's TLV's sanity assuming
1962 * 2 bytes first, and it does not pass, assume that ASs are
1963 * encoded in 4 bytes format and move on.
1964 */
1965 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1966
1967 while (tptr < pptr + len) {
1968 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1969 "?", GET_U_1(tptr)));
1970 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1971 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1972 ND_PRINT("%s ",
1973 as_printf(ndo, astostr, sizeof(astostr),
1974 as_size == 2 ?
1975 GET_BE_U_2(tptr + i + 2) :
1976 GET_BE_U_4(tptr + i + 2)));
1977 }
1978 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1979 "?", GET_U_1(tptr)));
1980 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1981 }
1982 break;
1983 case BGPTYPE_NEXT_HOP:
1984 if (len != 4)
1985 ND_PRINT("invalid len");
1986 else {
1987 ND_TCHECK_4(tptr);
1988 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
1989 }
1990 break;
1991 case BGPTYPE_MULTI_EXIT_DISC:
1992 case BGPTYPE_LOCAL_PREF:
1993 if (len != 4)
1994 ND_PRINT("invalid len");
1995 else {
1996 ND_PRINT("%u", GET_BE_U_4(tptr));
1997 }
1998 break;
1999 case BGPTYPE_ATOMIC_AGGREGATE:
2000 if (len != 0)
2001 ND_PRINT("invalid len");
2002 break;
2003 case BGPTYPE_AGGREGATOR:
2004
2005 /*
2006 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
2007 * the length of this PA can be either 6 bytes or 8 bytes.
2008 */
2009 if (len != 6 && len != 8) {
2010 ND_PRINT("invalid len");
2011 break;
2012 }
2013 ND_TCHECK_LEN(tptr, len);
2014 if (len == 6) {
2015 ND_PRINT(" AS #%s, origin %s",
2016 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
2017 GET_IPADDR_STRING(tptr + 2));
2018 } else {
2019 ND_PRINT(" AS #%s, origin %s",
2020 as_printf(ndo, astostr, sizeof(astostr),
2021 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
2022 }
2023 break;
2024 case BGPTYPE_AGGREGATOR4:
2025 if (len != 8) {
2026 ND_PRINT("invalid len");
2027 break;
2028 }
2029 ND_TCHECK_8(tptr);
2030 ND_PRINT(" AS #%s, origin %s",
2031 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
2032 GET_IPADDR_STRING(tptr + 4));
2033 break;
2034 case BGPTYPE_COMMUNITIES:
2035 if (len % 4) {
2036 ND_PRINT("invalid len");
2037 break;
2038 }
2039 while (tlen != 0) {
2040 uint32_t comm;
2041 ND_TCHECK_4(tptr);
2042 if (tlen < 4)
2043 goto trunc;
2044 comm = GET_BE_U_4(tptr);
2045 switch (comm) {
2046 case BGP_COMMUNITY_NO_EXPORT:
2047 ND_PRINT(" NO_EXPORT");
2048 break;
2049 case BGP_COMMUNITY_NO_ADVERT:
2050 ND_PRINT(" NO_ADVERTISE");
2051 break;
2052 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2053 ND_PRINT(" NO_EXPORT_SUBCONFED");
2054 break;
2055 default:
2056 ND_PRINT("%u:%u%s",
2057 (comm >> 16) & 0xffff,
2058 comm & 0xffff,
2059 (tlen>4) ? ", " : "");
2060 break;
2061 }
2062 tlen -=4;
2063 tptr +=4;
2064 }
2065 break;
2066 case BGPTYPE_ORIGINATOR_ID:
2067 if (len != 4) {
2068 ND_PRINT("invalid len");
2069 break;
2070 }
2071 ND_TCHECK_4(tptr);
2072 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2073 break;
2074 case BGPTYPE_CLUSTER_LIST:
2075 if (len % 4) {
2076 ND_PRINT("invalid len");
2077 break;
2078 }
2079 while (tlen != 0) {
2080 ND_TCHECK_4(tptr);
2081 if (tlen < 4)
2082 goto trunc;
2083 ND_PRINT("%s%s",
2084 GET_IPADDR_STRING(tptr),
2085 (tlen>4) ? ", " : "");
2086 tlen -=4;
2087 tptr +=4;
2088 }
2089 break;
2090 case BGPTYPE_MP_REACH_NLRI:
2091 ND_TCHECK_3(tptr);
2092 if (tlen < 3)
2093 goto trunc;
2094 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2095 if (ret == -2)
2096 goto trunc;
2097 if (ret < 0)
2098 break;
2099
2100 tptr += 3;
2101 tlen -= 3;
2102
2103 ND_TCHECK_1(tptr);
2104 if (tlen < 1)
2105 goto trunc;
2106 nhlen = GET_U_1(tptr);
2107 tptr++;
2108 tlen--;
2109
2110 if (nhlen) {
2111 u_int nnh = 0;
2112 uint8_t tnhlen = nhlen;
2113 if (tlen < tnhlen)
2114 goto trunc;
2115 ND_PRINT("\n\t nexthop: ");
2116 while (tnhlen != 0) {
2117 if (nnh++ > 0) {
2118 ND_PRINT(", " );
2119 }
2120 switch(af<<8 | safi) {
2121 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2122 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2123 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2124 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2125 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2126 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2127 case (AFNUM_INET<<8 | SAFNUM_MDT):
2128 if (tnhlen < sizeof(nd_ipv4)) {
2129 ND_PRINT("invalid len");
2130 tptr += tnhlen;
2131 tlen -= tnhlen;
2132 tnhlen = 0;
2133 } else {
2134 ND_TCHECK_LEN(tptr, sizeof(nd_ipv4));
2135 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2136 tptr += sizeof(nd_ipv4);
2137 tnhlen -= sizeof(nd_ipv4);
2138 tlen -= sizeof(nd_ipv4);
2139 }
2140 break;
2141 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2142 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2143 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2144 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2145 ND_PRINT("invalid len");
2146 tptr += tnhlen;
2147 tlen -= tnhlen;
2148 tnhlen = 0;
2149 } else {
2150 ND_TCHECK_LEN(tptr,
2151 sizeof(nd_ipv4) + BGP_VPN_RD_LEN);
2152 ND_PRINT("RD: %s, %s",
2153 bgp_vpn_rd_print(ndo, tptr),
2154 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2155 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2156 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2157 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2158 }
2159 break;
2160 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2161 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2162 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2163 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2164 if (tnhlen < sizeof(nd_ipv6)) {
2165 ND_PRINT("invalid len");
2166 tptr += tnhlen;
2167 tlen -= tnhlen;
2168 tnhlen = 0;
2169 } else {
2170 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2171 tptr += sizeof(nd_ipv6);
2172 tlen -= sizeof(nd_ipv6);
2173 tnhlen -= sizeof(nd_ipv6);
2174 }
2175 break;
2176 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2177 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2178 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2179 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2180 ND_PRINT("invalid len");
2181 tptr += tnhlen;
2182 tlen -= tnhlen;
2183 tnhlen = 0;
2184 } else {
2185 ND_TCHECK_LEN(tptr,
2186 sizeof(nd_ipv6) + BGP_VPN_RD_LEN);
2187 ND_PRINT("RD: %s, %s",
2188 bgp_vpn_rd_print(ndo, tptr),
2189 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2190 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2191 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2192 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2193 }
2194 break;
2195 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2196 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2197 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2198 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2199 if (tnhlen < sizeof(nd_ipv4)) {
2200 ND_PRINT("invalid len");
2201 tptr += tnhlen;
2202 tlen -= tnhlen;
2203 tnhlen = 0;
2204 } else {
2205 ND_TCHECK_LEN(tptr, sizeof(nd_ipv4));
2206 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2207 tptr += (sizeof(nd_ipv4));
2208 tlen -= (sizeof(nd_ipv4));
2209 tnhlen -= (sizeof(nd_ipv4));
2210 }
2211 break;
2212 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2213 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2214 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2215 ND_TCHECK_LEN(tptr, tnhlen);
2216 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2217 tptr += tnhlen;
2218 tlen -= tnhlen;
2219 tnhlen = 0;
2220 break;
2221
2222 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2223 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2224 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2225 if (tnhlen < BGP_VPN_RD_LEN+1) {
2226 ND_PRINT("invalid len");
2227 tptr += tnhlen;
2228 tlen -= tnhlen;
2229 tnhlen = 0;
2230 } else {
2231 ND_TCHECK_LEN(tptr, tnhlen);
2232 ND_PRINT("RD: %s, %s",
2233 bgp_vpn_rd_print(ndo, tptr),
2234 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2235 /* rfc986 mapped IPv4 address ? */
2236 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2237 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2238 /* rfc1888 mapped IPv6 address ? */
2239 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2240 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2241 tptr += tnhlen;
2242 tlen -= tnhlen;
2243 tnhlen = 0;
2244 }
2245 break;
2246 default:
2247 /*
2248 * bgp_mp_af_print() should have saved us from
2249 * an unsupported AFI/SAFI.
2250 */
2251 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2252 tptr += tnhlen;
2253 tlen -= tnhlen;
2254 tnhlen = 0;
2255 goto done;
2256 break;
2257 }
2258 }
2259 }
2260 ND_PRINT(", nh-length: %u", nhlen);
2261
2262 /* As per RFC 2858; this is reserved in RFC 4760 */
2263 if (tlen < 1)
2264 goto trunc;
2265 snpa = GET_U_1(tptr);
2266 tptr++;
2267 tlen--;
2268
2269 if (snpa) {
2270 ND_PRINT("\n\t %u SNPA", snpa);
2271 for (/*nothing*/; snpa != 0; snpa--) {
2272 uint8_t snpalen;
2273 if (tlen < 1)
2274 goto trunc;
2275 snpalen = GET_U_1(tptr);
2276 ND_PRINT("\n\t %u bytes", snpalen);
2277 tptr++;
2278 tlen--;
2279 if (tlen < snpalen)
2280 goto trunc;
2281 ND_TCHECK_LEN(tptr, snpalen);
2282 tptr += snpalen;
2283 tlen -= snpalen;
2284 }
2285 } else {
2286 ND_PRINT(", no SNPA");
2287 }
2288
2289 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2290 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2291
2292 while (tptr < pptr + len) {
2293 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2294 add_path4, add_path6);
2295 if (advance == -2)
2296 goto trunc;
2297 if (advance < 0)
2298 break;
2299 tptr += advance;
2300 }
2301 break;
2302
2303 case BGPTYPE_MP_UNREACH_NLRI:
2304 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2305 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2306 if (ret == -2)
2307 goto trunc;
2308 if (ret < 0)
2309 break;
2310
2311 if (len == BGP_MP_NLRI_MINSIZE)
2312 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2313
2314 tptr += 3;
2315
2316 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2317 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2318
2319 while (tptr < pptr + len) {
2320 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2321 add_path4, add_path6);
2322 if (advance == -2)
2323 goto trunc;
2324 if (advance < 0)
2325 break;
2326 tptr += advance;
2327 }
2328 break;
2329 case BGPTYPE_EXTD_COMMUNITIES:
2330 if (len % 8) {
2331 ND_PRINT("invalid len");
2332 break;
2333 }
2334 while (tlen != 0) {
2335 uint16_t extd_comm;
2336
2337 ND_TCHECK_2(tptr);
2338 if (tlen < 2)
2339 goto trunc;
2340 extd_comm=GET_BE_U_2(tptr);
2341
2342 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2343 tok2str(bgp_extd_comm_subtype_values,
2344 "unknown extd community typecode",
2345 extd_comm),
2346 extd_comm,
2347 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2348
2349 ND_TCHECK_8(tptr);
2350 if (tlen < 8)
2351 goto trunc;
2352 ND_PRINT(": ");
2353 bgp_extended_community_print(ndo, tptr);
2354 tlen -= 8;
2355 tptr += 8;
2356 }
2357 break;
2358
2359 case BGPTYPE_PMSI_TUNNEL:
2360 {
2361 uint8_t tunnel_type, flags;
2362
2363 ND_TCHECK_5(tptr);
2364 if (tlen < 5)
2365 goto trunc;
2366 flags = GET_U_1(tptr);
2367 tunnel_type = GET_U_1(tptr + 1);
2368
2369 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2370 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2371 tunnel_type,
2372 bittok2str(bgp_pmsi_flag_values, "none", flags),
2373 GET_BE_U_3(tptr + 2)>>4);
2374
2375 tptr +=5;
2376 tlen -= 5;
2377
2378 switch (tunnel_type) {
2379 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2380 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2381 ND_TCHECK_8(tptr);
2382 ND_PRINT("\n\t Sender %s, P-Group %s",
2383 GET_IPADDR_STRING(tptr),
2384 GET_IPADDR_STRING(tptr+4));
2385 break;
2386
2387 case BGP_PMSI_TUNNEL_PIM_SSM:
2388 ND_TCHECK_8(tptr);
2389 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2390 GET_IPADDR_STRING(tptr),
2391 GET_IPADDR_STRING(tptr+4));
2392 break;
2393 case BGP_PMSI_TUNNEL_INGRESS:
2394 ND_TCHECK_4(tptr);
2395 ND_PRINT("\n\t Tunnel-Endpoint %s",
2396 GET_IPADDR_STRING(tptr));
2397 break;
2398 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2399 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2400 ND_TCHECK_8(tptr);
2401 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2402 GET_IPADDR_STRING(tptr),
2403 GET_BE_U_4(tptr + 4));
2404 break;
2405 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2406 ND_TCHECK_8(tptr);
2407 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2408 GET_IPADDR_STRING(tptr),
2409 GET_BE_U_4(tptr + 4));
2410 break;
2411 default:
2412 if (ndo->ndo_vflag <= 1) {
2413 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2414 }
2415 }
2416 break;
2417 }
2418 case BGPTYPE_AIGP:
2419 {
2420 uint8_t type;
2421 uint16_t length;
2422
2423 while (tlen >= 3) {
2424
2425 ND_TCHECK_3(tptr);
2426
2427 type = GET_U_1(tptr);
2428 length = GET_BE_U_2(tptr + 1);
2429 tptr += 3;
2430 tlen -= 3;
2431
2432 ND_PRINT("\n\t %s TLV (%u), length %u",
2433 tok2str(bgp_aigp_values, "Unknown", type),
2434 type, length);
2435
2436 if (length < 3)
2437 goto trunc;
2438 length -= 3;
2439
2440 /*
2441 * Check if we can read the TLV data.
2442 */
2443 ND_TCHECK_LEN(tptr + 3, length);
2444 if (tlen < length)
2445 goto trunc;
2446
2447 switch (type) {
2448
2449 case BGP_AIGP_TLV:
2450 if (length < 8)
2451 goto trunc;
2452 ND_PRINT(", metric %" PRIu64,
2453 GET_BE_U_8(tptr));
2454 break;
2455
2456 default:
2457 if (ndo->ndo_vflag <= 1) {
2458 print_unknown_data(ndo, tptr,"\n\t ", length);
2459 }
2460 }
2461
2462 tptr += length;
2463 tlen -= length;
2464 }
2465 break;
2466 }
2467 case BGPTYPE_ATTR_SET:
2468 ND_TCHECK_4(tptr);
2469 if (len < 4)
2470 goto trunc;
2471 ND_PRINT("\n\t Origin AS: %s",
2472 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2473 tptr += 4;
2474 len -= 4;
2475
2476 while (len) {
2477 u_int aflags, alenlen, alen;
2478
2479 ND_TCHECK_2(tptr);
2480 if (len < 2) {
2481 ND_PRINT(" [path attr too short]");
2482 tptr += len;
2483 break;
2484 }
2485 aflags = GET_U_1(tptr);
2486 atype = GET_U_1(tptr + 1);
2487 tptr += 2;
2488 len -= 2;
2489 alenlen = bgp_attr_lenlen(aflags, tptr);
2490 ND_TCHECK_LEN(tptr, alenlen);
2491 if (len < alenlen) {
2492 ND_PRINT(" [path attr too short]");
2493 tptr += len;
2494 break;
2495 }
2496 alen = bgp_attr_len(aflags, tptr);
2497 tptr += alenlen;
2498 len -= alenlen;
2499
2500 ND_PRINT("\n\t %s (%u), length: %u",
2501 tok2str(bgp_attr_values,
2502 "Unknown Attribute", atype),
2503 atype,
2504 alen);
2505
2506 if (aflags) {
2507 ND_PRINT(", Flags [%s%s%s%s",
2508 aflags & 0x80 ? "O" : "",
2509 aflags & 0x40 ? "T" : "",
2510 aflags & 0x20 ? "P" : "",
2511 aflags & 0x10 ? "E" : "");
2512 if (aflags & 0xf)
2513 ND_PRINT("+%x", aflags & 0xf);
2514 ND_PRINT("]");
2515 }
2516 ND_PRINT(": ");
2517 if (len < alen) {
2518 ND_PRINT(" [path attr too short]");
2519 tptr += len;
2520 break;
2521 }
2522 /*
2523 * The protocol encoding per se allows ATTR_SET to be nested
2524 * as many times as the message can accommodate. This printer
2525 * used to be able to recurse into ATTR_SET contents until the
2526 * stack exhaustion, but now there is a limit on that (if live
2527 * protocol exchange goes that many levels deep, something is
2528 * probably wrong anyway). Feel free to refine this value if
2529 * you can find the spec with respective normative text.
2530 */
2531 if (attr_set_level == 10)
2532 ND_PRINT("(too many nested levels, not recursing)");
2533 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2534 return 0;
2535 tptr += alen;
2536 len -= alen;
2537 }
2538 break;
2539
2540 case BGPTYPE_LARGE_COMMUNITY:
2541 if (len == 0 || len % 12) {
2542 ND_PRINT("invalid len");
2543 break;
2544 }
2545 ND_PRINT("\n\t ");
2546 while (len != 0) {
2547 ND_TCHECK_LEN(tptr, 12);
2548 ND_PRINT("%u:%u:%u%s",
2549 GET_BE_U_4(tptr),
2550 GET_BE_U_4(tptr + 4),
2551 GET_BE_U_4(tptr + 8),
2552 (len > 12) ? ", " : "");
2553 tptr += 12;
2554 /*
2555 * len will always be a multiple of 12, as per the above,
2556 * so this will never underflow.
2557 */
2558 len -= 12;
2559 }
2560 break;
2561 default:
2562 ND_TCHECK_LEN(pptr, len);
2563 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2564 if (ndo->ndo_vflag <= 1)
2565 print_unknown_data(ndo, pptr, "\n\t ", len);
2566 break;
2567 }
2568 done:
2569 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2570 ND_TCHECK_LEN(pptr, len);
2571 print_unknown_data(ndo, pptr, "\n\t ", len);
2572 }
2573 return 1;
2574
2575 trunc:
2576 return 0;
2577 }
2578
2579 static void
2580 bgp_capabilities_print(netdissect_options *ndo,
2581 const u_char *opt, u_int caps_len)
2582 {
2583 u_int cap_type, cap_len, tcap_len, cap_offset;
2584 u_int i = 0;
2585
2586 while (i < caps_len) {
2587 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2588 cap_type=GET_U_1(opt + i);
2589 cap_len=GET_U_1(opt + i + 1);
2590 ND_PRINT("\n\t %s (%u), length: %u",
2591 tok2str(bgp_capcode_values, "Unknown", cap_type),
2592 cap_type,
2593 cap_len);
2594 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2595 switch (cap_type) {
2596 case BGP_CAPCODE_MP:
2597 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2598 if (cap_len < 4) {
2599 ND_PRINT(" (too short, < 4)");
2600 return;
2601 }
2602 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2603 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2604 GET_BE_U_2(opt + i + 2),
2605 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2606 GET_U_1(opt + i + 5));
2607 break;
2608 case BGP_CAPCODE_ML:
2609 cap_offset = 2;
2610 tcap_len = cap_len;
2611 while (tcap_len >= 4) {
2612 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2613 tok2str(af_values, "Unknown",
2614 GET_BE_U_2(opt + i + cap_offset)),
2615 GET_BE_U_2(opt + i + cap_offset),
2616 tok2str(bgp_safi_values, "Unknown",
2617 GET_U_1(opt + i + cap_offset + 2)),
2618 GET_U_1(opt + i + cap_offset + 2),
2619 GET_U_1(opt + i + cap_offset + 3));
2620 tcap_len -= 4;
2621 cap_offset += 4;
2622 }
2623 break;
2624 case BGP_CAPCODE_RESTART:
2625 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2626 if (cap_len < 2) {
2627 ND_PRINT(" (too short, < 2)");
2628 return;
2629 }
2630 tcap_len=cap_len;
2631 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2632 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2633 GET_BE_U_2(opt + i + 2)&0xfff);
2634 tcap_len-=2;
2635 cap_offset=4;
2636 while(tcap_len>=4) {
2637 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2638 tok2str(af_values,"Unknown",
2639 GET_BE_U_2(opt + i + cap_offset)),
2640 GET_BE_U_2(opt + i + cap_offset),
2641 tok2str(bgp_safi_values,"Unknown",
2642 GET_U_1(opt + i + cap_offset + 2)),
2643 GET_U_1(opt + (i + cap_offset + 2)),
2644 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2645 tcap_len -= 4;
2646 cap_offset += 4;
2647 }
2648 break;
2649 case BGP_CAPCODE_RR:
2650 case BGP_CAPCODE_LLGR:
2651 case BGP_CAPCODE_RR_CISCO:
2652 break;
2653 case BGP_CAPCODE_AS_NEW:
2654 /*
2655 * Extract the 4 byte AS number encoded.
2656 */
2657 if (cap_len < 4) {
2658 ND_PRINT(" (too short, < 4)");
2659 return;
2660 }
2661 ND_PRINT("\n\t\t 4 Byte AS %s",
2662 as_printf(ndo, astostr, sizeof(astostr),
2663 GET_BE_U_4(opt + i + 2)));
2664 break;
2665 case BGP_CAPCODE_ADD_PATH:
2666 if (cap_len == 0) {
2667 ND_PRINT(" (bogus)"); /* length */
2668 break;
2669 }
2670 tcap_len=cap_len;
2671 cap_offset=2;
2672 while (tcap_len != 0) {
2673 if (tcap_len < 4) {
2674 nd_print_invalid(ndo);
2675 break;
2676 }
2677 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2678 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2679 GET_BE_U_2(opt + i + cap_offset),
2680 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2681 GET_U_1(opt + (i + cap_offset + 2)),
2682 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2683 );
2684 tcap_len -= 4;
2685 cap_offset += 4;
2686 }
2687 break;
2688 default:
2689 ND_PRINT("\n\t\tno decoder for Capability %u",
2690 cap_type);
2691 if (ndo->ndo_vflag <= 1)
2692 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2693 cap_len);
2694 break;
2695 }
2696 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2697 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2698 }
2699 i += BGP_CAP_HEADER_SIZE + cap_len;
2700 }
2701 return;
2702
2703 trunc:
2704 nd_print_trunc(ndo);
2705 }
2706
2707 static void
2708 bgp_open_print(netdissect_options *ndo,
2709 const u_char *dat, u_int length)
2710 {
2711 const struct bgp_open *bgp_open_header;
2712 u_int optslen;
2713 const struct bgp_opt *bgpopt;
2714 const u_char *opt;
2715 u_int i;
2716
2717 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2718 if (length < BGP_OPEN_SIZE)
2719 goto trunc;
2720
2721 bgp_open_header = (const struct bgp_open *)dat;
2722
2723 ND_PRINT("\n\t Version %u, ",
2724 GET_U_1(bgp_open_header->bgpo_version));
2725 ND_PRINT("my AS %s, ",
2726 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2727 ND_PRINT("Holdtime %us, ",
2728 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2729 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2730 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2731 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2732
2733 opt = dat + BGP_OPEN_SIZE;
2734 length -= BGP_OPEN_SIZE;
2735
2736 i = 0;
2737 while (i < optslen) {
2738 uint8_t opt_type, opt_len;
2739
2740 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2741 if (length < BGP_OPT_SIZE + i)
2742 goto trunc;
2743 bgpopt = (const struct bgp_opt *)(opt + i);
2744 opt_type = GET_U_1(bgpopt->bgpopt_type);
2745 opt_len = GET_U_1(bgpopt->bgpopt_len);
2746 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2747 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2748 opt_type, opt_len);
2749 break;
2750 }
2751
2752 ND_PRINT("\n\t Option %s (%u), length: %u",
2753 tok2str(bgp_opt_values,"Unknown",opt_type),
2754 opt_type,
2755 opt_len);
2756
2757 /* now let's decode the options we know*/
2758 switch(opt_type) {
2759
2760 case BGP_OPT_CAP:
2761 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2762 opt_len);
2763 break;
2764
2765 case BGP_OPT_AUTH:
2766 default:
2767 ND_PRINT("\n\t no decoder for option %u",
2768 opt_type);
2769 break;
2770 }
2771 i += BGP_OPT_SIZE + opt_len;
2772 }
2773 return;
2774 trunc:
2775 nd_print_trunc(ndo);
2776 }
2777
2778 static void
2779 bgp_update_print(netdissect_options *ndo,
2780 const u_char *dat, u_int length)
2781 {
2782 const u_char *p;
2783 u_int withdrawn_routes_len;
2784 char buf[MAXHOSTNAMELEN + 100];
2785 int wpfx;
2786 u_int len;
2787 int i;
2788 int add_path;
2789 u_int path_id = 0;
2790
2791 ND_TCHECK_LEN(dat, BGP_SIZE);
2792 if (length < BGP_SIZE)
2793 goto trunc;
2794 p = dat + BGP_SIZE;
2795 length -= BGP_SIZE;
2796
2797 /* Unfeasible routes */
2798 ND_TCHECK_2(p);
2799 if (length < 2)
2800 goto trunc;
2801 withdrawn_routes_len = GET_BE_U_2(p);
2802 p += 2;
2803 length -= 2;
2804 if (withdrawn_routes_len > 1) {
2805 /*
2806 * Without keeping state from the original NLRI message,
2807 * it's not possible to tell if this a v4 or v6 route,
2808 * so only try to decode it if we're not v6 enabled.
2809 */
2810 ND_TCHECK_LEN(p, withdrawn_routes_len);
2811 if (length < withdrawn_routes_len)
2812 goto trunc;
2813 ND_PRINT("\n\t Withdrawn routes:");
2814 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2815 while (withdrawn_routes_len != 0) {
2816 if (add_path) {
2817 if (withdrawn_routes_len < 4) {
2818 p += withdrawn_routes_len;
2819 length -= withdrawn_routes_len;
2820 break;
2821 }
2822 path_id = GET_BE_U_4(p);
2823 p += 4;
2824 length -= 4;
2825 withdrawn_routes_len -= 4;
2826 }
2827 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2828 if (wpfx == -1) {
2829 ND_PRINT("\n\t (illegal prefix length)");
2830 break;
2831 } else if (wpfx == -2)
2832 goto trunc;
2833 else if (wpfx == -3)
2834 goto trunc; /* bytes left, but not enough */
2835 else {
2836 ND_PRINT("\n\t %s", buf);
2837 if (add_path) {
2838 ND_PRINT(" Path Id: %u", path_id);
2839 }
2840 p += wpfx;
2841 length -= wpfx;
2842 withdrawn_routes_len -= wpfx;
2843 }
2844 }
2845 } else {
2846 ND_TCHECK_LEN(p, withdrawn_routes_len);
2847 if (length < withdrawn_routes_len)
2848 goto trunc;
2849 p += withdrawn_routes_len;
2850 length -= withdrawn_routes_len;
2851 }
2852
2853 ND_TCHECK_2(p);
2854 if (length < 2)
2855 goto trunc;
2856 len = GET_BE_U_2(p);
2857 p += 2;
2858 length -= 2;
2859
2860 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2861 /* No withdrawn routes, no path attributes, no NLRI */
2862 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2863 return;
2864 }
2865
2866 if (len) {
2867 /* do something more useful!*/
2868 while (len) {
2869 uint8_t aflags, atype, alenlen;
2870 uint16_t alen;
2871
2872 ND_TCHECK_2(p);
2873 if (length < 2)
2874 goto trunc;
2875 if (len < 2) {
2876 ND_PRINT("\n\t [path attrs too short]");
2877 p += len;
2878 length -= len;
2879 break;
2880 }
2881 aflags = GET_U_1(p);
2882 atype = GET_U_1(p + 1);
2883 p += 2;
2884 len -= 2;
2885 length -= 2;
2886 alenlen = bgp_attr_lenlen(aflags, p);
2887 ND_TCHECK_LEN(p, alenlen);
2888 if (length < alenlen)
2889 goto trunc;
2890 if (len < alenlen) {
2891 ND_PRINT("\n\t [path attrs too short]");
2892 p += len;
2893 length -= len;
2894 break;
2895 }
2896 alen = bgp_attr_len(aflags, p);
2897 p += alenlen;
2898 len -= alenlen;
2899 length -= alenlen;
2900
2901 ND_PRINT("\n\t %s (%u), length: %u",
2902 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2903 atype,
2904 alen);
2905
2906 if (aflags) {
2907 ND_PRINT(", Flags [%s%s%s%s",
2908 aflags & 0x80 ? "O" : "",
2909 aflags & 0x40 ? "T" : "",
2910 aflags & 0x20 ? "P" : "",
2911 aflags & 0x10 ? "E" : "");
2912 if (aflags & 0xf)
2913 ND_PRINT("+%x", aflags & 0xf);
2914 ND_PRINT("]: ");
2915 }
2916 if (len < alen) {
2917 ND_PRINT(" [path attrs too short]");
2918 p += len;
2919 length -= len;
2920 break;
2921 }
2922 if (length < alen)
2923 goto trunc;
2924 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2925 goto trunc;
2926 p += alen;
2927 len -= alen;
2928 length -= alen;
2929 }
2930 }
2931
2932 if (length) {
2933 add_path = check_add_path(ndo, p, length, 32);
2934 ND_PRINT("\n\t Updated routes:");
2935 while (length != 0) {
2936 if (add_path) {
2937 ND_TCHECK_4(p);
2938 if (length < 4)
2939 goto trunc;
2940 path_id = GET_BE_U_4(p);
2941 p += 4;
2942 length -= 4;
2943 }
2944 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2945 if (i == -1) {
2946 ND_PRINT("\n\t (illegal prefix length)");
2947 break;
2948 } else if (i == -2)
2949 goto trunc;
2950 else if (i == -3)
2951 goto trunc; /* bytes left, but not enough */
2952 else {
2953 ND_PRINT("\n\t %s", buf);
2954 if (add_path) {
2955 ND_PRINT(" Path Id: %u", path_id);
2956 }
2957 p += i;
2958 length -= i;
2959 }
2960 }
2961 }
2962 return;
2963 trunc:
2964 nd_print_trunc(ndo);
2965 }
2966
2967 static void
2968 bgp_notification_print(netdissect_options *ndo,
2969 const u_char *dat, u_int length)
2970 {
2971 const struct bgp_notification *bgp_notification_header;
2972 const u_char *tptr;
2973 uint8_t bgpn_major, bgpn_minor;
2974 uint8_t shutdown_comm_length;
2975 uint8_t remainder_offset;
2976
2977 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2978 if (length<BGP_NOTIFICATION_SIZE)
2979 return;
2980
2981 bgp_notification_header = (const struct bgp_notification *)dat;
2982 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
2983 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
2984
2985 ND_PRINT(", %s (%u)",
2986 tok2str(bgp_notify_major_values, "Unknown Error",
2987 bgpn_major),
2988 bgpn_major);
2989
2990 switch (bgpn_major) {
2991
2992 case BGP_NOTIFY_MAJOR_MSG:
2993 ND_PRINT(", subcode %s (%u)",
2994 tok2str(bgp_notify_minor_msg_values, "Unknown",
2995 bgpn_minor),
2996 bgpn_minor);
2997 break;
2998 case BGP_NOTIFY_MAJOR_OPEN:
2999 ND_PRINT(", subcode %s (%u)",
3000 tok2str(bgp_notify_minor_open_values, "Unknown",
3001 bgpn_minor),
3002 bgpn_minor);
3003 break;
3004 case BGP_NOTIFY_MAJOR_UPDATE:
3005 ND_PRINT(", subcode %s (%u)",
3006 tok2str(bgp_notify_minor_update_values, "Unknown",
3007 bgpn_minor),
3008 bgpn_minor);
3009 break;
3010 case BGP_NOTIFY_MAJOR_FSM:
3011 ND_PRINT(" subcode %s (%u)",
3012 tok2str(bgp_notify_minor_fsm_values, "Unknown",
3013 bgpn_minor),
3014 bgpn_minor);
3015 break;
3016 case BGP_NOTIFY_MAJOR_CAP:
3017 ND_PRINT(" subcode %s (%u)",
3018 tok2str(bgp_notify_minor_cap_values, "Unknown",
3019 bgpn_minor),
3020 bgpn_minor);
3021 break;
3022 case BGP_NOTIFY_MAJOR_CEASE:
3023 ND_PRINT(", subcode %s (%u)",
3024 tok2str(bgp_notify_minor_cease_values, "Unknown",
3025 bgpn_minor),
3026 bgpn_minor);
3027
3028 /* draft-ietf-idr-cease-subcode-02 mentions optionally 7 bytes
3029 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
3030 */
3031 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
3032 tptr = dat + BGP_NOTIFICATION_SIZE;
3033 ND_TCHECK_7(tptr);
3034 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
3035 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
3036 GET_BE_U_2(tptr),
3037 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
3038 GET_U_1((tptr + 2)),
3039 GET_BE_U_4(tptr + 3));
3040 }
3041 /*
3042 * draft-ietf-idr-shutdown describes a method to send a communication
3043 * intended for human consumption regarding the Administrative Shutdown
3044 */
3045 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
3046 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
3047 length >= BGP_NOTIFICATION_SIZE + 1) {
3048 tptr = dat + BGP_NOTIFICATION_SIZE;
3049 shutdown_comm_length = GET_U_1(tptr);
3050 remainder_offset = 0;
3051 /* garbage, hexdump it all */
3052 if (shutdown_comm_length > BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN ||
3053 shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
3054 ND_PRINT(", invalid Shutdown Communication length");
3055 }
3056 else if (shutdown_comm_length == 0) {
3057 ND_PRINT(", empty Shutdown Communication");
3058 remainder_offset += 1;
3059 }
3060 /* a proper shutdown communication */
3061 else {
3062 ND_TCHECK_LEN(tptr + 1, shutdown_comm_length);
3063 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3064 (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL);
3065 ND_PRINT("\"");
3066 remainder_offset += shutdown_comm_length + 1;
3067 }
3068 /* if there is trailing data, hexdump it */
3069 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3070 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3071 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3072 }
3073 }
3074 break;
3075 default:
3076 break;
3077 }
3078
3079 return;
3080 trunc:
3081 nd_print_trunc(ndo);
3082 }
3083
3084 static void
3085 bgp_route_refresh_print(netdissect_options *ndo,
3086 const u_char *pptr, u_int len)
3087 {
3088 const struct bgp_route_refresh *bgp_route_refresh_header;
3089
3090 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3091
3092 /* some little sanity checking */
3093 if (len<BGP_ROUTE_REFRESH_SIZE)
3094 return;
3095
3096 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3097
3098 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3099 tok2str(af_values,"Unknown",
3100 GET_BE_U_2(bgp_route_refresh_header->afi)),
3101 GET_BE_U_2(bgp_route_refresh_header->afi),
3102 tok2str(bgp_safi_values,"Unknown",
3103 GET_U_1(bgp_route_refresh_header->safi)),
3104 GET_U_1(bgp_route_refresh_header->safi));
3105
3106 if (ndo->ndo_vflag > 1) {
3107 ND_TCHECK_LEN(pptr, len);
3108 print_unknown_data(ndo, pptr, "\n\t ", len);
3109 }
3110
3111 return;
3112 trunc:
3113 nd_print_trunc(ndo);
3114 }
3115
3116 static int
3117 bgp_pdu_print(netdissect_options *ndo,
3118 const u_char *dat, u_int length)
3119 {
3120 const struct bgp *bgp_header;
3121 uint8_t bgp_type;
3122
3123 ND_TCHECK_LEN(dat, BGP_SIZE);
3124 bgp_header = (const struct bgp *)dat;
3125 bgp_type = GET_U_1(bgp_header->bgp_type);
3126
3127 ND_PRINT("\n\t%s Message (%u), length: %u",
3128 tok2str(bgp_msg_values, "Unknown", bgp_type),
3129 bgp_type,
3130 length);
3131
3132 switch (bgp_type) {
3133 case BGP_OPEN:
3134 bgp_open_print(ndo, dat, length);
3135 break;
3136 case BGP_UPDATE:
3137 bgp_update_print(ndo, dat, length);
3138 break;
3139 case BGP_NOTIFICATION:
3140 bgp_notification_print(ndo, dat, length);
3141 break;
3142 case BGP_KEEPALIVE:
3143 break;
3144 case BGP_ROUTE_REFRESH:
3145 bgp_route_refresh_print(ndo, dat, length);
3146 break;
3147 default:
3148 /* we have no decoder for the BGP message */
3149 ND_TCHECK_LEN(dat, length);
3150 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3151 print_unknown_data(ndo, dat, "\n\t ", length);
3152 break;
3153 }
3154 return 1;
3155 trunc:
3156 nd_print_trunc(ndo);
3157 return 0;
3158 }
3159
3160 void
3161 bgp_print(netdissect_options *ndo,
3162 const u_char *dat, u_int length _U_)
3163 {
3164 const u_char *p;
3165 const u_char *ep = ndo->ndo_snapend;
3166 const u_char *start;
3167 const u_char marker[] = {
3168 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3169 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3170 };
3171 const struct bgp *bgp_header;
3172 uint16_t hlen;
3173
3174 ndo->ndo_protocol = "bgp";
3175 ND_PRINT(": BGP");
3176
3177 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3178 return;
3179
3180 p = dat;
3181 start = p;
3182 while (p < ep) {
3183 if (!ND_TTEST_1(p))
3184 break;
3185 if (GET_U_1(p) != 0xff) {
3186 p++;
3187 continue;
3188 }
3189
3190 if (!ND_TTEST_LEN(p, sizeof(marker)))
3191 break;
3192 if (memcmp(p, marker, sizeof(marker)) != 0) {
3193 p++;
3194 continue;
3195 }
3196
3197 /* found BGP header */
3198 ND_TCHECK_LEN(p, BGP_SIZE);
3199 bgp_header = (const struct bgp *)p;
3200
3201 if (start != p)
3202 nd_print_trunc(ndo);
3203
3204 hlen = GET_BE_U_2(bgp_header->bgp_len);
3205 if (hlen < BGP_SIZE) {
3206 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3207 nd_print_invalid(ndo);
3208 break;
3209 }
3210
3211 if (ND_TTEST_LEN(p, hlen)) {
3212 if (!bgp_pdu_print(ndo, p, hlen))
3213 return;
3214 p += hlen;
3215 start = p;
3216 } else {
3217 ND_PRINT("\n[|BGP %s]",
3218 tok2str(bgp_msg_values,
3219 "Unknown Message Type",
3220 GET_U_1(bgp_header->bgp_type)));
3221 break;
3222 }
3223 }
3224
3225 return;
3226
3227 trunc:
3228 nd_print_trunc(ndo);
3229 }
[mirror] the TCPdump network dissector