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bgp: fix some length checks.
[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 static char astostr[20];
561
562 /*
563 * as_printf
564 *
565 * Convert an AS number into a string and return string pointer.
566 *
567 * Depending on bflag is set or not, AS number is converted into ASDOT notation
568 * or plain number notation.
569 *
570 */
571 static char *
572 as_printf(netdissect_options *ndo,
573 char *str, size_t size, u_int asnum)
574 {
575 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
576 snprintf(str, size, "%u", asnum);
577 } else {
578 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
579 }
580 return str;
581 }
582
583 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
584
585 int
586 decode_prefix4(netdissect_options *ndo,
587 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
588 {
589 nd_ipv4 addr;
590 u_int plen, plenbytes;
591
592 ND_TCHECK_1(pptr);
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 ND_TCHECK_LEN(pptr, sizeof(nd_ipv6));
692 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
693 break;
694 default:
695 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
696 break;
697 }
698 pos += strlen(pos);
699
700 trunc:
701 *(pos) = '\0';
702 return (addr);
703 }
704
705 /*
706 * bgp_vpn_sg_print
707 *
708 * print an multicast s,g entry into a buffer.
709 * the s,g entry is encoded like this.
710 *
711 * +-----------------------------------+
712 * | Multicast Source Length (1 octet) |
713 * +-----------------------------------+
714 * | Multicast Source (Variable) |
715 * +-----------------------------------+
716 * | Multicast Group Length (1 octet) |
717 * +-----------------------------------+
718 * | Multicast Group (Variable) |
719 * +-----------------------------------+
720 *
721 * return the number of bytes read from the wire.
722 */
723 static u_int
724 bgp_vpn_sg_print(netdissect_options *ndo,
725 const u_char *pptr, char *buf, size_t buflen)
726 {
727 uint8_t addr_length;
728 u_int total_length, offset;
729
730 total_length = 0;
731
732 /* Source address length, encoded in bits */
733 ND_TCHECK_1(pptr);
734 addr_length = GET_U_1(pptr);
735 pptr++;
736
737 /* Source address */
738 ND_TCHECK_LEN(pptr, (addr_length >> 3));
739 total_length += (addr_length >> 3) + 1;
740 offset = (u_int)strlen(buf);
741 if (addr_length) {
742 snprintf(buf + offset, buflen - offset, ", Source %s",
743 bgp_vpn_ip_print(ndo, pptr, addr_length));
744 pptr += (addr_length >> 3);
745 }
746
747 /* Group address length, encoded in bits */
748 ND_TCHECK_1(pptr);
749 addr_length = GET_U_1(pptr);
750 pptr++;
751
752 /* Group address */
753 ND_TCHECK_LEN(pptr, (addr_length >> 3));
754 total_length += (addr_length >> 3) + 1;
755 offset = (u_int)strlen(buf);
756 if (addr_length) {
757 snprintf(buf + offset, buflen - offset, ", Group %s",
758 bgp_vpn_ip_print(ndo, pptr, addr_length));
759 pptr += (addr_length >> 3);
760 }
761
762 trunc:
763 return (total_length);
764 }
765
766 /* Print an RFC 4364 Route Distinguisher */
767 const char *
768 bgp_vpn_rd_print(netdissect_options *ndo,
769 const u_char *pptr)
770 {
771 /* allocate space for the largest possible string */
772 static char rd[sizeof("xxxxxxxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
773 char *pos = rd;
774
775 /* ok lets load the RD format */
776 switch (GET_BE_U_2(pptr)) {
777
778 case 0:
779 /* 2-byte-AS:number fmt */
780 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
781 GET_BE_U_2(pptr + 2),
782 GET_BE_U_4(pptr + 4),
783 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
784 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
785 break;
786
787 case 1:
788 /* IP-address:AS fmt */
789 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
790 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
791 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
792 GET_BE_U_2(pptr + 6));
793 break;
794
795 case 2:
796 /* 4-byte-AS:number fmt */
797 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
798 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
799 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
800 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
801 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
802 break;
803 default:
804 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
805 break;
806 }
807 pos += strlen(pos);
808 *(pos) = '\0';
809 return (rd);
810 }
811
812 /*
813 * Print an RFC 4360 Extended Community.
814 */
815 static void
816 bgp_extended_community_print(netdissect_options *ndo,
817 const u_char *pptr)
818 {
819 union { /* copy buffer for bandwidth values */
820 float f;
821 uint32_t i;
822 } bw;
823
824 switch (GET_BE_U_2(pptr)) {
825
826 case BGP_EXT_COM_RT_0:
827 case BGP_EXT_COM_RO_0:
828 case BGP_EXT_COM_L2VPN_RT_0:
829 ND_PRINT("%u:%u (= %s)",
830 GET_BE_U_2(pptr + 2),
831 GET_BE_U_4(pptr + 4),
832 GET_IPADDR_STRING(pptr+4));
833 break;
834
835 case BGP_EXT_COM_RT_1:
836 case BGP_EXT_COM_RO_1:
837 case BGP_EXT_COM_L2VPN_RT_1:
838 case BGP_EXT_COM_VRF_RT_IMP:
839 ND_PRINT("%s:%u",
840 GET_IPADDR_STRING(pptr+2),
841 GET_BE_U_2(pptr + 6));
842 break;
843
844 case BGP_EXT_COM_RT_2:
845 case BGP_EXT_COM_RO_2:
846 ND_PRINT("%s:%u",
847 as_printf(ndo, astostr, sizeof(astostr),
848 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
849 break;
850
851 case BGP_EXT_COM_LINKBAND:
852 bw.i = GET_BE_U_4(pptr + 2);
853 ND_PRINT("bandwidth: %.3f Mbps",
854 bw.f*8/1000000);
855 break;
856
857 case BGP_EXT_COM_VPN_ORIGIN:
858 case BGP_EXT_COM_VPN_ORIGIN2:
859 case BGP_EXT_COM_VPN_ORIGIN3:
860 case BGP_EXT_COM_VPN_ORIGIN4:
861 case BGP_EXT_COM_OSPF_RID:
862 case BGP_EXT_COM_OSPF_RID2:
863 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
864 break;
865
866 case BGP_EXT_COM_OSPF_RTYPE:
867 case BGP_EXT_COM_OSPF_RTYPE2:
868 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
869 GET_IPADDR_STRING(pptr+2),
870 tok2str(bgp_extd_comm_ospf_rtype_values,
871 "unknown (0x%02x)",
872 GET_U_1((pptr + 6))),
873 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
874 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
875 break;
876
877 case BGP_EXT_COM_L2INFO:
878 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
879 tok2str(l2vpn_encaps_values,
880 "unknown encaps",
881 GET_U_1((pptr + 2))),
882 GET_U_1((pptr + 3)),
883 GET_BE_U_2(pptr + 4));
884 break;
885
886 case BGP_EXT_COM_SOURCE_AS:
887 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
888 break;
889
890 case BGP_EXT_COM_ENCAP:
891 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
892 "unknown encaps",
893 GET_BE_U_2(pptr + 6)));
894 break;
895
896 default:
897 ND_PRINT("%02x%02x%02x%02x%02x%02x",
898 GET_U_1(pptr + 2),
899 GET_U_1(pptr + 3),
900 GET_U_1(pptr + 4),
901 GET_U_1(pptr + 5),
902 GET_U_1(pptr + 6),
903 GET_U_1(pptr + 7));
904 break;
905 }
906 }
907
908 /*
909 * RFC4684 (Section 4)/RFC2858 (Section 4).
910 * RTC membership prefix is structured as follows
911 * [prefix-len] [origin-as] [route-target]
912 * The route-target is encoded as RT ext-comms.
913 * Prefix-len may be 0, 32..96
914 *
915 * Note that pptr is not packet data - it is
916 * a buffer owned by our caller - therefore GET_*
917 * macros can not be used.
918 */
919 static char *
920 bgp_rt_prefix_print(netdissect_options *ndo,
921 const u_char *pptr,
922 u_int plen)
923 {
924 /* allocate space for the largest possible string */
925 char rtc_prefix_in_hex[20] = "";
926 u_int rtc_prefix_in_hex_len = 0;
927 static char output[60]; /* max response string */
928 uint16_t ec_type = 0;
929 u_int octet_count;
930 u_int i;
931
932 if (plen == 0) {
933 snprintf(output, sizeof(output), "route-target: 0:0/0");
934 return (output);
935 }
936
937 /* hex representation of the prefix */
938 octet_count = (plen+7)/8;
939 for (i=0; i<octet_count; i++) {
940 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
941 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
942 "%02x%s", *(pptr+i),
943 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
944 }
945
946 if (plen < 16) {
947 /*
948 * The prefix is too short to include the full ext-comm type,
949 * so we have no way to parse it further.
950 */
951 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
952 rtc_prefix_in_hex, plen);
953 return (output);
954 }
955
956 /*
957 * get the ext-comm type
958 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
959 * hense EXTRACT_*() macros are safe.
960 */
961 ec_type = EXTRACT_BE_U_2(pptr);
962 switch (ec_type) {
963 case BGP_EXT_COM_RT_0:
964 /* 2-byte-AS:number fmt */
965 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
966 EXTRACT_BE_U_2(pptr+2),
967 EXTRACT_BE_U_4(pptr+4),
968 plen, rtc_prefix_in_hex);
969 break;
970
971 case BGP_EXT_COM_RT_1:
972 /* IP-address:AS fmt */
973 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
974 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
975 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
976 break;
977
978 case BGP_EXT_COM_RT_2:
979 /* 4-byte-AS:number fmt */
980 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
981 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
982 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
983 break;
984
985 default:
986 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
987 ec_type,
988 rtc_prefix_in_hex, plen);
989 break;
990 }
991 return (output);
992 }
993
994 /* RFC 4684 */
995 static int
996 decode_rt_routing_info(netdissect_options *ndo,
997 const u_char *pptr)
998 {
999 uint8_t route_target[8];
1000 u_int plen;
1001 char asbuf[sizeof(astostr)]; /* bgp_vpn_rd_print() overwrites astostr */
1002 u_int num_octets;
1003
1004 /* NLRI "prefix length" from RFC 2858 Section 4. */
1005 ND_TCHECK_1(pptr);
1006 plen = GET_U_1(pptr); /* get prefix length */
1007
1008 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1009 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1010 * target" fields inside the "prefix" depending on its length.
1011 */
1012 if (0 == plen) {
1013 /* Without "origin AS", without "route target". */
1014 ND_PRINT("\n\t default route target");
1015 return 1;
1016 }
1017
1018 if (32 > plen) {
1019 ND_PRINT("\n\t (illegal prefix length)");
1020 return -1;
1021 }
1022
1023 /* With at least "origin AS", possibly with "route target". */
1024 ND_TCHECK_4(pptr + 1);
1025 as_printf(ndo, asbuf, sizeof(asbuf), GET_BE_U_4(pptr + 1));
1026
1027 plen -= 32; /* adjust prefix length */
1028
1029 if (64 < plen) {
1030 ND_PRINT("\n\t (illegal prefix length)");
1031 return -1;
1032 }
1033
1034 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1035 * and gives the number of octets in the variable-length "route
1036 * target" field inside this NLRI "prefix". Look for it.
1037 */
1038 memset(&route_target, 0, sizeof(route_target));
1039 num_octets = (plen + 7) / 8;
1040 ND_TCHECK_LEN(pptr[5], num_octets);
1041 memcpy(&route_target, &pptr[5], num_octets);
1042 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1043 if (plen % 8) {
1044 ((u_char *)&route_target)[num_octets - 1] &=
1045 ((0xff00 >> (plen % 8)) & 0xff);
1046 }
1047 ND_PRINT("\n\t origin AS: %s, %s",
1048 asbuf,
1049 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1050
1051 return 5 + num_octets;
1052 trunc:
1053 return -2;
1054 }
1055
1056 static int
1057 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1058 const u_char *pptr, char *buf, size_t buflen)
1059 {
1060 nd_ipv4 addr;
1061 u_int plen;
1062
1063 ND_TCHECK_1(pptr);
1064 plen = GET_U_1(pptr); /* get prefix length */
1065
1066 if ((24+64) > plen)
1067 return -1;
1068
1069 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1070
1071 if (32 < plen)
1072 return -1;
1073
1074 memset(&addr, 0, sizeof(addr));
1075 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1076 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1077 if (plen % 8) {
1078 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1079 ((0xff00 >> (plen % 8)) & 0xff);
1080 }
1081 /* the label may get offsetted by 4 bits so lets shift it right */
1082 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1083 bgp_vpn_rd_print(ndo, pptr+4),
1084 ipaddr_string(ndo, (const u_char *)&addr),
1085 plen,
1086 GET_BE_U_3(pptr + 1)>>4,
1087 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1088
1089 return 12 + (plen + 7) / 8;
1090
1091 trunc:
1092 return -2;
1093 }
1094
1095 /*
1096 * +-------------------------------+
1097 * | |
1098 * | RD:IPv4-address (12 octets) |
1099 * | |
1100 * +-------------------------------+
1101 * | MDT Group-address (4 octets) |
1102 * +-------------------------------+
1103 */
1104
1105 #define MDT_VPN_NLRI_LEN 16
1106
1107 static int
1108 decode_mdt_vpn_nlri(netdissect_options *ndo,
1109 const u_char *pptr, char *buf, size_t buflen)
1110 {
1111 const u_char *rd;
1112 const u_char *vpn_ip;
1113
1114 ND_TCHECK_1(pptr);
1115
1116 /* if the NLRI is not predefined length, quit.*/
1117 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1118 return -1;
1119 pptr++;
1120
1121 /* RD */
1122 ND_TCHECK_8(pptr);
1123 rd = pptr;
1124 pptr += 8;
1125
1126 /* IPv4 address */
1127 ND_TCHECK_LEN(pptr, sizeof(nd_ipv4));
1128 vpn_ip = pptr;
1129 pptr += sizeof(nd_ipv4);
1130
1131 /* MDT Group Address */
1132 ND_TCHECK_LEN(pptr, sizeof(nd_ipv4));
1133
1134 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1135 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1136
1137 return MDT_VPN_NLRI_LEN + 1;
1138
1139 trunc:
1140 return -2;
1141 }
1142
1143 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1144 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1145 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1146 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1147 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1148 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1149 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1150
1151 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1152 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1153 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1154 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1155 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1156 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1157 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1158 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1159 { 0, NULL}
1160 };
1161
1162 static int
1163 decode_multicast_vpn(netdissect_options *ndo,
1164 const u_char *pptr, char *buf, size_t buflen)
1165 {
1166 uint8_t route_type, route_length;
1167 u_int addr_length, sg_length;
1168 u_int offset;
1169
1170 ND_TCHECK_2(pptr);
1171 route_type = GET_U_1(pptr);
1172 pptr++;
1173 route_length = GET_U_1(pptr);
1174 pptr++;
1175
1176 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1177 tok2str(bgp_multicast_vpn_route_type_values,
1178 "Unknown", route_type),
1179 route_type, route_length);
1180
1181 switch(route_type) {
1182 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1183 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1184 offset = (u_int)strlen(buf);
1185 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1186 bgp_vpn_rd_print(ndo, pptr),
1187 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1188 (route_length - BGP_VPN_RD_LEN) << 3));
1189 break;
1190 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1191 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1192 offset = (u_int)strlen(buf);
1193 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1194 bgp_vpn_rd_print(ndo, pptr),
1195 as_printf(ndo, astostr, sizeof(astostr),
1196 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1197 break;
1198
1199 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1200 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1201 offset = (u_int)strlen(buf);
1202 snprintf(buf + offset, buflen - offset, ", RD: %s",
1203 bgp_vpn_rd_print(ndo, pptr));
1204 pptr += BGP_VPN_RD_LEN;
1205
1206 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1207 addr_length = route_length - sg_length;
1208
1209 ND_TCHECK_LEN(pptr, addr_length);
1210 offset = (u_int)strlen(buf);
1211 snprintf(buf + offset, buflen - offset, ", Originator %s",
1212 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1213 break;
1214
1215 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1216 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1217 offset = (u_int)strlen(buf);
1218 snprintf(buf + offset, buflen - offset, ", RD: %s",
1219 bgp_vpn_rd_print(ndo, pptr));
1220 pptr += BGP_VPN_RD_LEN;
1221
1222 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1223 break;
1224
1225 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1226 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1227 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1228 offset = (u_int)strlen(buf);
1229 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1230 bgp_vpn_rd_print(ndo, pptr),
1231 as_printf(ndo, astostr, sizeof(astostr),
1232 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1233 pptr += BGP_VPN_RD_LEN + 4;
1234
1235 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1236 break;
1237
1238 /*
1239 * no per route-type printing yet.
1240 */
1241 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1242 default:
1243 break;
1244 }
1245
1246 return route_length + 2;
1247
1248 trunc:
1249 return -2;
1250 }
1251
1252 /*
1253 * As I remember, some versions of systems have an snprintf() that
1254 * returns -1 if the buffer would have overflowed. If the return
1255 * value is negative, set buflen to 0, to indicate that we've filled
1256 * the buffer up.
1257 *
1258 * If the return value is greater than buflen, that means that
1259 * the buffer would have overflowed; again, set buflen to 0 in
1260 * that case.
1261 */
1262 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1263 if (stringlen<0) \
1264 buflen=0; \
1265 else if ((u_int)stringlen>buflen) \
1266 buflen=0; \
1267 else { \
1268 buflen-=stringlen; \
1269 buf+=stringlen; \
1270 }
1271
1272 static int
1273 decode_labeled_vpn_l2(netdissect_options *ndo,
1274 const u_char *pptr, char *buf, size_t buflen)
1275 {
1276 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1277 int stringlen;
1278
1279 ND_TCHECK_2(pptr);
1280 plen = GET_BE_U_2(pptr);
1281 tlen = plen;
1282 pptr += 2;
1283 /* Old and new L2VPN NLRI share AFI/SAFI
1284 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1285 * and > 17 as old format. Complain for the middle case
1286 */
1287 if (plen == 12) {
1288 /* assume AD-only with RD, BGPNH */
1289 ND_TCHECK_LEN(pptr, 12);
1290 buf[0] = '\0';
1291 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1292 bgp_vpn_rd_print(ndo, pptr),
1293 GET_IPADDR_STRING(pptr+8));
1294 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1295 pptr += 12;
1296 tlen -= 12;
1297 return plen + 2;
1298 } else if (plen > 17) {
1299 /* assume old format */
1300 /* RD, ID, LBLKOFF, LBLBASE */
1301
1302 ND_TCHECK_LEN(pptr, 15);
1303 buf[0] = '\0';
1304 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1305 bgp_vpn_rd_print(ndo, pptr),
1306 GET_BE_U_2(pptr + 8),
1307 GET_BE_U_2(pptr + 10),
1308 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1309 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1310 pptr += 15;
1311 tlen -= 15;
1312
1313 /* ok now the variable part - lets read out TLVs*/
1314 while (tlen != 0) {
1315 if (tlen < 3) {
1316 if (buflen != 0) {
1317 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1318 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1319 }
1320 return plen + 2;
1321 }
1322 ND_TCHECK_3(pptr);
1323 tlv_type = GET_U_1(pptr);
1324 pptr++;
1325 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1326 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1327 pptr += 2;
1328
1329 switch(tlv_type) {
1330 case 1:
1331 if (buflen != 0) {
1332 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1333 tlv_type,
1334 tlv_len);
1335 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1336 }
1337 while (ttlv_len != 0) {
1338 if (tlen < 1) {
1339 if (buflen != 0) {
1340 stringlen=snprintf(buf,buflen, " (ran past the end)");
1341 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1342 }
1343 return plen + 2;
1344 }
1345 ND_TCHECK_1(pptr);
1346 if (buflen != 0) {
1347 stringlen=snprintf(buf,buflen, "%02x",
1348 GET_U_1(pptr));
1349 pptr++;
1350 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1351 }
1352 ttlv_len--;
1353 tlen--;
1354 }
1355 break;
1356 default:
1357 if (buflen != 0) {
1358 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1359 tlv_type,
1360 tlv_len);
1361 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1362 }
1363 if (tlen < ttlv_len) {
1364 if (buflen != 0) {
1365 stringlen=snprintf(buf,buflen, " (ran past the end)");
1366 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1367 }
1368 return plen + 2;
1369 }
1370 tlen -= ttlv_len;
1371 break;
1372 }
1373 }
1374 return plen + 2;
1375 } else {
1376 /* complain bitterly ? */
1377 /* fall through */
1378 goto trunc;
1379 }
1380
1381 trunc:
1382 return -2;
1383 }
1384
1385 int
1386 decode_prefix6(netdissect_options *ndo,
1387 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1388 {
1389 nd_ipv6 addr;
1390 u_int plen, plenbytes;
1391
1392 ND_TCHECK_1(pd);
1393 ITEMCHECK(1);
1394 plen = GET_U_1(pd);
1395 if (128 < plen)
1396 return -1;
1397 itemlen -= 1;
1398
1399 memset(&addr, 0, sizeof(addr));
1400 plenbytes = (plen + 7) / 8;
1401 ND_TCHECK_LEN(pd + 1, plenbytes);
1402 ITEMCHECK(plenbytes);
1403 memcpy(&addr, pd + 1, plenbytes);
1404 if (plen % 8) {
1405 addr[plenbytes - 1] &=
1406 ((0xff00 >> (plen % 8)) & 0xff);
1407 }
1408 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1409 return 1 + plenbytes;
1410
1411 trunc:
1412 return -2;
1413
1414 badtlv:
1415 return -3;
1416 }
1417
1418 static int
1419 decode_labeled_prefix6(netdissect_options *ndo,
1420 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1421 {
1422 nd_ipv6 addr;
1423 u_int plen, plenbytes;
1424
1425 /* prefix length and label = 4 bytes */
1426 ND_TCHECK_4(pptr);
1427 ITEMCHECK(4);
1428 plen = GET_U_1(pptr); /* get prefix length */
1429
1430 if (24 > plen)
1431 return -1;
1432
1433 plen -= 24; /* adjust prefixlen - labellength */
1434
1435 if (128 < plen)
1436 return -1;
1437 itemlen -= 4;
1438
1439 memset(&addr, 0, sizeof(addr));
1440 plenbytes = (plen + 7) / 8;
1441 ND_TCHECK_LEN(pptr + 4, plenbytes);
1442 memcpy(&addr, pptr + 4, plenbytes);
1443 if (plen % 8) {
1444 addr[plenbytes - 1] &=
1445 ((0xff00 >> (plen % 8)) & 0xff);
1446 }
1447 /* the label may get offsetted by 4 bits so lets shift it right */
1448 snprintf(buf, buflen, "%s/%u, label:%u %s",
1449 ip6addr_string(ndo, (const u_char *)&addr),
1450 plen,
1451 GET_BE_U_3(pptr + 1)>>4,
1452 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1453
1454 return 4 + plenbytes;
1455
1456 trunc:
1457 return -2;
1458
1459 badtlv:
1460 return -3;
1461 }
1462
1463 static int
1464 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1465 const u_char *pptr, char *buf, size_t buflen)
1466 {
1467 nd_ipv6 addr;
1468 u_int plen;
1469
1470 ND_TCHECK_1(pptr);
1471 plen = GET_U_1(pptr); /* get prefix length */
1472
1473 if ((24+64) > plen)
1474 return -1;
1475
1476 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1477
1478 if (128 < plen)
1479 return -1;
1480
1481 memset(&addr, 0, sizeof(addr));
1482 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1483 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1484 if (plen % 8) {
1485 addr[(plen + 7) / 8 - 1] &=
1486 ((0xff00 >> (plen % 8)) & 0xff);
1487 }
1488 /* the label may get offsetted by 4 bits so lets shift it right */
1489 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1490 bgp_vpn_rd_print(ndo, pptr+4),
1491 ip6addr_string(ndo, (const u_char *)&addr),
1492 plen,
1493 GET_BE_U_3(pptr + 1)>>4,
1494 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1495
1496 return 12 + (plen + 7) / 8;
1497
1498 trunc:
1499 return -2;
1500 }
1501
1502 static int
1503 decode_clnp_prefix(netdissect_options *ndo,
1504 const u_char *pptr, char *buf, size_t buflen)
1505 {
1506 uint8_t addr[19];
1507 u_int plen;
1508
1509 ND_TCHECK_1(pptr);
1510 plen = GET_U_1(pptr); /* get prefix length */
1511
1512 if (152 < plen)
1513 return -1;
1514
1515 memset(&addr, 0, sizeof(addr));
1516 ND_TCHECK_LEN(pptr + 4, (plen + 7) / 8);
1517 memcpy(&addr, pptr + 4, (plen + 7) / 8);
1518 if (plen % 8) {
1519 addr[(plen + 7) / 8 - 1] &=
1520 ((0xff00 >> (plen % 8)) & 0xff);
1521 }
1522 snprintf(buf, buflen, "%s/%u",
1523 isonsap_string(ndo, addr,(plen + 7) / 8),
1524 plen);
1525
1526 return 1 + (plen + 7) / 8;
1527
1528 trunc:
1529 return -2;
1530 }
1531
1532 static int
1533 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1534 const u_char *pptr, char *buf, size_t buflen)
1535 {
1536 uint8_t addr[19];
1537 u_int plen;
1538
1539 ND_TCHECK_1(pptr);
1540 plen = GET_U_1(pptr); /* get prefix length */
1541
1542 if ((24+64) > plen)
1543 return -1;
1544
1545 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1546
1547 if (152 < plen)
1548 return -1;
1549
1550 memset(&addr, 0, sizeof(addr));
1551 ND_TCHECK_LEN(pptr + 12, (plen + 7) / 8);
1552 memcpy(&addr, pptr + 12, (plen + 7) / 8);
1553 if (plen % 8) {
1554 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1555 }
1556 /* the label may get offsetted by 4 bits so lets shift it right */
1557 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1558 bgp_vpn_rd_print(ndo, pptr+4),
1559 isonsap_string(ndo, addr,(plen + 7) / 8),
1560 plen,
1561 GET_BE_U_3(pptr + 1)>>4,
1562 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1563
1564 return 12 + (plen + 7) / 8;
1565
1566 trunc:
1567 return -2;
1568 }
1569
1570 /*
1571 * bgp_attr_get_as_size
1572 *
1573 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1574 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1575 * support, exchange AS-Path with the same path-attribute type value 0x02.
1576 */
1577 static u_int
1578 bgp_attr_get_as_size(netdissect_options *ndo,
1579 uint8_t bgpa_type, const u_char *pptr, u_int len)
1580 {
1581 const u_char *tptr = pptr;
1582
1583 /*
1584 * If the path attribute is the optional AS4 path type, then we already
1585 * know, that ASs must be encoded in 4 byte format.
1586 */
1587 if (bgpa_type == BGPTYPE_AS4_PATH) {
1588 return 4;
1589 }
1590
1591 /*
1592 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1593 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1594 * each.
1595 */
1596 while (tptr < pptr + len) {
1597 ND_TCHECK_1(tptr);
1598
1599 /*
1600 * If we do not find a valid segment type, our guess might be wrong.
1601 */
1602 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1603 goto trunc;
1604 }
1605 ND_TCHECK_1(tptr + 1);
1606 tptr += 2 + GET_U_1(tptr + 1) * 2;
1607 }
1608
1609 /*
1610 * If we correctly reached end of the AS path attribute data content,
1611 * then most likely ASs were indeed encoded as 2 bytes.
1612 */
1613 if (tptr == pptr + len) {
1614 return 2;
1615 }
1616
1617 trunc:
1618
1619 /*
1620 * We can come here, either we did not have enough data, or if we
1621 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1622 * so that calller can try to decode each AS as of 4 bytes. If indeed
1623 * there was not enough data, it will crib and end the parse anyways.
1624 */
1625 return 4;
1626 }
1627
1628 /*
1629 * The only way to know that a BGP UPDATE message is using add path is
1630 * by checking if the capability is in the OPEN message which we may have missed.
1631 * So this function checks if it is possible that the update could contain add path
1632 * and if so it checks that standard BGP doesn't make sense.
1633 */
1634 static int
1635 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1636 u_int max_prefix_length)
1637 {
1638 u_int offset, prefix_length;
1639
1640 if (length < 5) {
1641 return 0;
1642 }
1643
1644 /*
1645 * Scan through the NLRI information under the assumpetion that
1646 * it doesn't have path IDs.
1647 */
1648 for (offset = 0; offset < length;) {
1649 offset += 4;
1650 if (!ND_TTEST_1(pptr + offset)) {
1651 /* We ran out of captured data; quit scanning. */
1652 break;
1653 }
1654 prefix_length = GET_U_1(pptr + offset);
1655 /*
1656 * Add 4 to cover the path id
1657 * and check the prefix length isn't greater than 32/128.
1658 */
1659 if (prefix_length > max_prefix_length) {
1660 return 0;
1661 }
1662 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1663 offset += 1 + ((prefix_length + 7) / 8);
1664 }
1665 /* check we haven't gone past the end of the section */
1666 if (offset > length) {
1667 return 0;
1668 }
1669
1670 /* check it's not standard BGP */
1671 for (offset = 0; offset < length; ) {
1672 if (!ND_TTEST_1(pptr + offset)) {
1673 /* We ran out of captured data; quit scanning. */
1674 break;
1675 }
1676 prefix_length = GET_U_1(pptr + offset);
1677 /*
1678 * If the prefix_length is zero (0.0.0.0/0)
1679 * and since it's not the only address (length >= 5)
1680 * then it is add-path
1681 */
1682 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1683 return 1;
1684 }
1685 offset += 1 + ((prefix_length + 7) / 8);
1686 }
1687 if (offset > length) {
1688 return 1;
1689 }
1690
1691 /* assume not add-path by default */
1692 return 0;
1693 }
1694
1695 static int
1696 bgp_mp_af_print(netdissect_options *ndo,
1697 const u_char *tptr, u_int tlen,
1698 uint16_t *afp, uint8_t *safip)
1699 {
1700 uint16_t af;
1701 uint8_t safi;
1702
1703 af = GET_BE_U_2(tptr);
1704 *afp = af;
1705 safi = GET_U_1(tptr + 2);
1706 *safip = safi;
1707
1708 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1709 tok2str(af_values, "Unknown AFI", af),
1710 af,
1711 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1712 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1713 safi);
1714
1715 switch(af<<8 | safi) {
1716 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1717 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1718 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1719 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1720 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1721 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1722 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1723 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1724 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1725 case (AFNUM_INET<<8 | SAFNUM_MDT):
1726 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1727 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1728 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1729 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1730 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1731 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1732 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1733 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1734 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1735 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1736 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1737 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1738 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1739 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1740 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1741 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1742 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1743 break;
1744 default:
1745 ND_TCHECK_LEN(tptr, tlen);
1746 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1747 if (ndo->ndo_vflag <= 1)
1748 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1749 return -1;
1750 }
1751 return 0;
1752 trunc:
1753 return -2;
1754 }
1755
1756 static int
1757 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1758 const u_char *tptr, u_int len,
1759 char *buf, size_t buflen,
1760 int add_path4, int add_path6)
1761 {
1762 int advance;
1763 u_int path_id = 0;
1764
1765 switch (af<<8 | safi) {
1766 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1767 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1768 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1769 if (add_path4) {
1770 path_id = GET_BE_U_4(tptr);
1771 tptr += 4;
1772 }
1773 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1774 if (advance == -1)
1775 ND_PRINT("\n\t (illegal prefix length)");
1776 else if (advance == -2)
1777 goto trunc;
1778 else if (advance == -3)
1779 break; /* bytes left, but not enough */
1780 else
1781 ND_PRINT("\n\t %s", buf);
1782 if (add_path4) {
1783 ND_PRINT(" Path Id: %u", path_id);
1784 advance += 4;
1785 }
1786 break;
1787 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1788 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1789 if (advance == -1)
1790 ND_PRINT("\n\t (illegal prefix length)");
1791 else if (advance == -2)
1792 goto trunc;
1793 else if (advance == -3)
1794 break; /* bytes left, but not enough */
1795 else
1796 ND_PRINT("\n\t %s", buf);
1797 break;
1798 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1799 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1800 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1801 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1802 if (advance == -1)
1803 ND_PRINT("\n\t (illegal prefix length)");
1804 else if (advance == -2)
1805 goto trunc;
1806 else
1807 ND_PRINT("\n\t %s", buf);
1808 break;
1809 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1810 advance = decode_rt_routing_info(ndo, tptr);
1811 if (advance == -2)
1812 goto trunc;
1813 break;
1814 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1815 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1816 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1817 if (advance == -1)
1818 ND_PRINT("\n\t (illegal prefix length)");
1819 else if (advance == -2)
1820 goto trunc;
1821 else
1822 ND_PRINT("\n\t %s", buf);
1823 break;
1824
1825 case (AFNUM_INET<<8 | SAFNUM_MDT):
1826 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1827 if (advance == -1)
1828 ND_PRINT("\n\t (illegal prefix length)");
1829 else if (advance == -2)
1830 goto trunc;
1831 else
1832 ND_PRINT("\n\t %s", buf);
1833 break;
1834 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1835 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1836 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1837 if (add_path6) {
1838 path_id = GET_BE_U_4(tptr);
1839 tptr += 4;
1840 }
1841 advance = decode_prefix6(ndo, tptr, len, buf, buflen);
1842 if (advance == -1)
1843 ND_PRINT("\n\t (illegal prefix length)");
1844 else if (advance == -2)
1845 goto trunc;
1846 else if (advance == -3)
1847 break; /* bytes left, but not enough */
1848 else
1849 ND_PRINT("\n\t %s", buf);
1850 if (add_path6) {
1851 ND_PRINT(" Path Id: %u", path_id);
1852 advance += 4;
1853 }
1854 break;
1855 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1856 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1857 if (advance == -1)
1858 ND_PRINT("\n\t (illegal prefix length)");
1859 else if (advance == -2)
1860 goto trunc;
1861 else if (advance == -3)
1862 break; /* bytes left, but not enough */
1863 else
1864 ND_PRINT("\n\t %s", buf);
1865 break;
1866 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1867 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1868 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1869 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1870 if (advance == -1)
1871 ND_PRINT("\n\t (illegal prefix length)");
1872 else if (advance == -2)
1873 goto trunc;
1874 else
1875 ND_PRINT("\n\t %s", buf);
1876 break;
1877 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1878 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1879 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1880 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1881 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1882 if (advance == -1)
1883 ND_PRINT("\n\t (illegal length)");
1884 else if (advance == -2)
1885 goto trunc;
1886 else
1887 ND_PRINT("\n\t %s", buf);
1888 break;
1889 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1890 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1891 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1892 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1893 if (advance == -1)
1894 ND_PRINT("\n\t (illegal prefix length)");
1895 else if (advance == -2)
1896 goto trunc;
1897 else
1898 ND_PRINT("\n\t %s", buf);
1899 break;
1900 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1901 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1902 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1903 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1904 if (advance == -1)
1905 ND_PRINT("\n\t (illegal prefix length)");
1906 else if (advance == -2)
1907 goto trunc;
1908 else
1909 ND_PRINT("\n\t %s", buf);
1910 break;
1911 default:
1912 /*
1913 * This should not happen, we should have been protected
1914 * by bgp_mp_af_print()'s return value.
1915 */
1916 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1917 advance = -4;
1918 break;
1919 }
1920 return advance;
1921 trunc: /* we rely on the caller to recognize -2 return value */
1922 return -2;
1923 }
1924
1925 static int
1926 bgp_attr_print(netdissect_options *ndo,
1927 uint8_t atype, const u_char *pptr, u_int len,
1928 const unsigned attr_set_level)
1929 {
1930 u_int i;
1931 uint16_t af;
1932 uint8_t safi, snpa, nhlen;
1933 int advance;
1934 u_int tlen;
1935 const u_char *tptr;
1936 char buf[MAXHOSTNAMELEN + 100];
1937 u_int as_size;
1938 int add_path4, add_path6;
1939 int ret;
1940
1941 tptr = pptr;
1942 tlen = len;
1943
1944 switch (atype) {
1945 case BGPTYPE_ORIGIN:
1946 if (len != 1)
1947 ND_PRINT("invalid len");
1948 else {
1949 ND_TCHECK_1(tptr);
1950 ND_PRINT("%s", tok2str(bgp_origin_values,
1951 "Unknown Origin Typecode",
1952 GET_U_1(tptr)));
1953 }
1954 break;
1955
1956 /*
1957 * Process AS4 byte path and AS2 byte path attributes here.
1958 */
1959 case BGPTYPE_AS4_PATH:
1960 case BGPTYPE_AS_PATH:
1961 if (len % 2) {
1962 ND_PRINT("invalid len");
1963 break;
1964 }
1965 if (!len) {
1966 ND_PRINT("empty");
1967 break;
1968 }
1969
1970 /*
1971 * BGP updates exchanged between New speakers that support 4
1972 * byte AS, ASs are always encoded in 4 bytes. There is no
1973 * definitive way to find this, just by the packet's
1974 * contents. So, check for packet's TLV's sanity assuming
1975 * 2 bytes first, and it does not pass, assume that ASs are
1976 * encoded in 4 bytes format and move on.
1977 */
1978 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1979
1980 while (tptr < pptr + len) {
1981 ND_TCHECK_1(tptr);
1982 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1983 "?", GET_U_1(tptr)));
1984 ND_TCHECK_1(tptr + 1);
1985 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1986 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1987 ND_PRINT("%s ",
1988 as_printf(ndo, astostr, sizeof(astostr),
1989 as_size == 2 ?
1990 GET_BE_U_2(tptr + i + 2) :
1991 GET_BE_U_4(tptr + i + 2)));
1992 }
1993 ND_TCHECK_1(tptr);
1994 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1995 "?", GET_U_1(tptr)));
1996 ND_TCHECK_1(tptr + 1);
1997 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1998 }
1999 break;
2000 case BGPTYPE_NEXT_HOP:
2001 if (len != 4)
2002 ND_PRINT("invalid len");
2003 else {
2004 ND_TCHECK_4(tptr);
2005 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2006 }
2007 break;
2008 case BGPTYPE_MULTI_EXIT_DISC:
2009 case BGPTYPE_LOCAL_PREF:
2010 if (len != 4)
2011 ND_PRINT("invalid len");
2012 else {
2013 ND_TCHECK_4(tptr);
2014 ND_PRINT("%u", GET_BE_U_4(tptr));
2015 }
2016 break;
2017 case BGPTYPE_ATOMIC_AGGREGATE:
2018 if (len != 0)
2019 ND_PRINT("invalid len");
2020 break;
2021 case BGPTYPE_AGGREGATOR:
2022
2023 /*
2024 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
2025 * the length of this PA can be either 6 bytes or 8 bytes.
2026 */
2027 if (len != 6 && len != 8) {
2028 ND_PRINT("invalid len");
2029 break;
2030 }
2031 ND_TCHECK_LEN(tptr, len);
2032 if (len == 6) {
2033 ND_PRINT(" AS #%s, origin %s",
2034 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
2035 GET_IPADDR_STRING(tptr + 2));
2036 } else {
2037 ND_PRINT(" AS #%s, origin %s",
2038 as_printf(ndo, astostr, sizeof(astostr),
2039 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
2040 }
2041 break;
2042 case BGPTYPE_AGGREGATOR4:
2043 if (len != 8) {
2044 ND_PRINT("invalid len");
2045 break;
2046 }
2047 ND_TCHECK_8(tptr);
2048 ND_PRINT(" AS #%s, origin %s",
2049 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
2050 GET_IPADDR_STRING(tptr + 4));
2051 break;
2052 case BGPTYPE_COMMUNITIES:
2053 if (len % 4) {
2054 ND_PRINT("invalid len");
2055 break;
2056 }
2057 while (tlen != 0) {
2058 uint32_t comm;
2059 ND_TCHECK_4(tptr);
2060 if (tlen < 4)
2061 goto trunc;
2062 comm = GET_BE_U_4(tptr);
2063 switch (comm) {
2064 case BGP_COMMUNITY_NO_EXPORT:
2065 ND_PRINT(" NO_EXPORT");
2066 break;
2067 case BGP_COMMUNITY_NO_ADVERT:
2068 ND_PRINT(" NO_ADVERTISE");
2069 break;
2070 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2071 ND_PRINT(" NO_EXPORT_SUBCONFED");
2072 break;
2073 default:
2074 ND_PRINT("%u:%u%s",
2075 (comm >> 16) & 0xffff,
2076 comm & 0xffff,
2077 (tlen>4) ? ", " : "");
2078 break;
2079 }
2080 tlen -=4;
2081 tptr +=4;
2082 }
2083 break;
2084 case BGPTYPE_ORIGINATOR_ID:
2085 if (len != 4) {
2086 ND_PRINT("invalid len");
2087 break;
2088 }
2089 ND_TCHECK_4(tptr);
2090 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2091 break;
2092 case BGPTYPE_CLUSTER_LIST:
2093 if (len % 4) {
2094 ND_PRINT("invalid len");
2095 break;
2096 }
2097 while (tlen != 0) {
2098 ND_TCHECK_4(tptr);
2099 if (tlen < 4)
2100 goto trunc;
2101 ND_PRINT("%s%s",
2102 GET_IPADDR_STRING(tptr),
2103 (tlen>4) ? ", " : "");
2104 tlen -=4;
2105 tptr +=4;
2106 }
2107 break;
2108 case BGPTYPE_MP_REACH_NLRI:
2109 ND_TCHECK_3(tptr);
2110 if (tlen < 3)
2111 goto trunc;
2112 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2113 if (ret == -2)
2114 goto trunc;
2115 if (ret < 0)
2116 break;
2117
2118 tptr += 3;
2119 tlen -= 3;
2120
2121 ND_TCHECK_1(tptr);
2122 if (tlen < 1)
2123 goto trunc;
2124 nhlen = GET_U_1(tptr);
2125 tptr++;
2126 tlen--;
2127
2128 if (nhlen) {
2129 u_int nnh = 0;
2130 uint8_t tnhlen = nhlen;
2131 if (tlen < tnhlen)
2132 goto trunc;
2133 ND_PRINT("\n\t nexthop: ");
2134 while (tnhlen != 0) {
2135 if (nnh++ > 0) {
2136 ND_PRINT(", " );
2137 }
2138 switch(af<<8 | safi) {
2139 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2140 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2141 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2142 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2143 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2144 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2145 case (AFNUM_INET<<8 | SAFNUM_MDT):
2146 if (tnhlen < sizeof(nd_ipv4)) {
2147 ND_PRINT("invalid len");
2148 tptr += tnhlen;
2149 tlen -= tnhlen;
2150 tnhlen = 0;
2151 } else {
2152 ND_TCHECK_LEN(tptr, sizeof(nd_ipv4));
2153 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2154 tptr += sizeof(nd_ipv4);
2155 tnhlen -= sizeof(nd_ipv4);
2156 tlen -= sizeof(nd_ipv4);
2157 }
2158 break;
2159 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2160 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2161 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2162 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2163 ND_PRINT("invalid len");
2164 tptr += tnhlen;
2165 tlen -= tnhlen;
2166 tnhlen = 0;
2167 } else {
2168 ND_TCHECK_LEN(tptr,
2169 sizeof(nd_ipv4) + BGP_VPN_RD_LEN);
2170 ND_PRINT("RD: %s, %s",
2171 bgp_vpn_rd_print(ndo, tptr),
2172 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2173 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2174 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2175 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2176 }
2177 break;
2178 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2179 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2180 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2181 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2182 if (tnhlen < sizeof(nd_ipv6)) {
2183 ND_PRINT("invalid len");
2184 tptr += tnhlen;
2185 tlen -= tnhlen;
2186 tnhlen = 0;
2187 } else {
2188 ND_TCHECK_LEN(tptr, sizeof(nd_ipv6));
2189 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2190 tptr += sizeof(nd_ipv6);
2191 tlen -= sizeof(nd_ipv6);
2192 tnhlen -= sizeof(nd_ipv6);
2193 }
2194 break;
2195 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2196 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2197 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2198 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2199 ND_PRINT("invalid len");
2200 tptr += tnhlen;
2201 tlen -= tnhlen;
2202 tnhlen = 0;
2203 } else {
2204 ND_TCHECK_LEN(tptr,
2205 sizeof(nd_ipv6) + BGP_VPN_RD_LEN);
2206 ND_PRINT("RD: %s, %s",
2207 bgp_vpn_rd_print(ndo, tptr),
2208 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2209 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2210 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2211 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2212 }
2213 break;
2214 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2215 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2216 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2217 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2218 if (tnhlen < sizeof(nd_ipv4)) {
2219 ND_PRINT("invalid len");
2220 tptr += tnhlen;
2221 tlen -= tnhlen;
2222 tnhlen = 0;
2223 } else {
2224 ND_TCHECK_LEN(tptr, sizeof(nd_ipv4));
2225 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2226 tptr += (sizeof(nd_ipv4));
2227 tlen -= (sizeof(nd_ipv4));
2228 tnhlen -= (sizeof(nd_ipv4));
2229 }
2230 break;
2231 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2232 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2233 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2234 ND_TCHECK_LEN(tptr, tnhlen);
2235 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2236 tptr += tnhlen;
2237 tlen -= tnhlen;
2238 tnhlen = 0;
2239 break;
2240
2241 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2242 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2243 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2244 if (tnhlen < BGP_VPN_RD_LEN+1) {
2245 ND_PRINT("invalid len");
2246 tptr += tnhlen;
2247 tlen -= tnhlen;
2248 tnhlen = 0;
2249 } else {
2250 ND_TCHECK_LEN(tptr, tnhlen);
2251 ND_PRINT("RD: %s, %s",
2252 bgp_vpn_rd_print(ndo, tptr),
2253 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2254 /* rfc986 mapped IPv4 address ? */
2255 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2256 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2257 /* rfc1888 mapped IPv6 address ? */
2258 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2259 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2260 tptr += tnhlen;
2261 tlen -= tnhlen;
2262 tnhlen = 0;
2263 }
2264 break;
2265 default:
2266 /*
2267 * bgp_mp_af_print() should have saved us from
2268 * an unsupported AFI/SAFI.
2269 */
2270 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2271 tptr += tnhlen;
2272 tlen -= tnhlen;
2273 tnhlen = 0;
2274 goto done;
2275 break;
2276 }
2277 }
2278 }
2279 ND_PRINT(", nh-length: %u", nhlen);
2280
2281 /* As per RFC 2858; this is reserved in RFC 4760 */
2282 if (tlen < 1)
2283 goto trunc;
2284 ND_TCHECK_1(tptr);
2285 snpa = GET_U_1(tptr);
2286 tptr++;
2287 tlen--;
2288
2289 if (snpa) {
2290 ND_PRINT("\n\t %u SNPA", snpa);
2291 for (/*nothing*/; snpa != 0; snpa--) {
2292 uint8_t snpalen;
2293 if (tlen < 1)
2294 goto trunc;
2295 ND_TCHECK_1(tptr);
2296 snpalen = GET_U_1(tptr);
2297 ND_PRINT("\n\t %u bytes", snpalen);
2298 tptr++;
2299 tlen--;
2300 if (tlen < snpalen)
2301 goto trunc;
2302 ND_TCHECK_LEN(tptr, snpalen);
2303 tptr += snpalen;
2304 tlen -= snpalen;
2305 }
2306 } else {
2307 ND_PRINT(", no SNPA");
2308 }
2309
2310 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2311 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2312
2313 while (tptr < pptr + len) {
2314 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2315 add_path4, add_path6);
2316 if (advance == -2)
2317 goto trunc;
2318 if (advance < 0)
2319 break;
2320 tptr += advance;
2321 }
2322 break;
2323
2324 case BGPTYPE_MP_UNREACH_NLRI:
2325 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2326 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2327 if (ret == -2)
2328 goto trunc;
2329 if (ret < 0)
2330 break;
2331
2332 if (len == BGP_MP_NLRI_MINSIZE)
2333 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2334
2335 tptr += 3;
2336
2337 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2338 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2339
2340 while (tptr < pptr + len) {
2341 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2342 add_path4, add_path6);
2343 if (advance == -2)
2344 goto trunc;
2345 if (advance < 0)
2346 break;
2347 tptr += advance;
2348 }
2349 break;
2350 case BGPTYPE_EXTD_COMMUNITIES:
2351 if (len % 8) {
2352 ND_PRINT("invalid len");
2353 break;
2354 }
2355 while (tlen != 0) {
2356 uint16_t extd_comm;
2357
2358 ND_TCHECK_2(tptr);
2359 if (tlen < 2)
2360 goto trunc;
2361 extd_comm=GET_BE_U_2(tptr);
2362
2363 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2364 tok2str(bgp_extd_comm_subtype_values,
2365 "unknown extd community typecode",
2366 extd_comm),
2367 extd_comm,
2368 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2369
2370 ND_TCHECK_8(tptr);
2371 if (tlen < 8)
2372 goto trunc;
2373 ND_PRINT(": ");
2374 bgp_extended_community_print(ndo, tptr);
2375 tlen -= 8;
2376 tptr += 8;
2377 }
2378 break;
2379
2380 case BGPTYPE_PMSI_TUNNEL:
2381 {
2382 uint8_t tunnel_type, flags;
2383
2384 ND_TCHECK_5(tptr);
2385 if (tlen < 5)
2386 goto trunc;
2387 flags = GET_U_1(tptr);
2388 tunnel_type = GET_U_1(tptr + 1);
2389
2390 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2391 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2392 tunnel_type,
2393 bittok2str(bgp_pmsi_flag_values, "none", flags),
2394 GET_BE_U_3(tptr + 2)>>4);
2395
2396 tptr +=5;
2397 tlen -= 5;
2398
2399 switch (tunnel_type) {
2400 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2401 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2402 ND_TCHECK_8(tptr);
2403 ND_PRINT("\n\t Sender %s, P-Group %s",
2404 GET_IPADDR_STRING(tptr),
2405 GET_IPADDR_STRING(tptr+4));
2406 break;
2407
2408 case BGP_PMSI_TUNNEL_PIM_SSM:
2409 ND_TCHECK_8(tptr);
2410 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2411 GET_IPADDR_STRING(tptr),
2412 GET_IPADDR_STRING(tptr+4));
2413 break;
2414 case BGP_PMSI_TUNNEL_INGRESS:
2415 ND_TCHECK_4(tptr);
2416 ND_PRINT("\n\t Tunnel-Endpoint %s",
2417 GET_IPADDR_STRING(tptr));
2418 break;
2419 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2420 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2421 ND_TCHECK_8(tptr);
2422 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2423 GET_IPADDR_STRING(tptr),
2424 GET_BE_U_4(tptr + 4));
2425 break;
2426 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2427 ND_TCHECK_8(tptr);
2428 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2429 GET_IPADDR_STRING(tptr),
2430 GET_BE_U_4(tptr + 4));
2431 break;
2432 default:
2433 if (ndo->ndo_vflag <= 1) {
2434 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2435 }
2436 }
2437 break;
2438 }
2439 case BGPTYPE_AIGP:
2440 {
2441 uint8_t type;
2442 uint16_t length;
2443
2444 while (tlen >= 3) {
2445
2446 ND_TCHECK_3(tptr);
2447
2448 type = GET_U_1(tptr);
2449 length = GET_BE_U_2(tptr + 1);
2450 tptr += 3;
2451 tlen -= 3;
2452
2453 ND_PRINT("\n\t %s TLV (%u), length %u",
2454 tok2str(bgp_aigp_values, "Unknown", type),
2455 type, length);
2456
2457 if (length < 3)
2458 goto trunc;
2459 length -= 3;
2460
2461 /*
2462 * Check if we can read the TLV data.
2463 */
2464 ND_TCHECK_LEN(tptr + 3, length);
2465 if (tlen < length)
2466 goto trunc;
2467
2468 switch (type) {
2469
2470 case BGP_AIGP_TLV:
2471 if (length < 8)
2472 goto trunc;
2473 ND_PRINT(", metric %" PRIu64,
2474 GET_BE_U_8(tptr));
2475 break;
2476
2477 default:
2478 if (ndo->ndo_vflag <= 1) {
2479 print_unknown_data(ndo, tptr,"\n\t ", length);
2480 }
2481 }
2482
2483 tptr += length;
2484 tlen -= length;
2485 }
2486 break;
2487 }
2488 case BGPTYPE_ATTR_SET:
2489 ND_TCHECK_4(tptr);
2490 if (len < 4)
2491 goto trunc;
2492 ND_PRINT("\n\t Origin AS: %s",
2493 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2494 tptr += 4;
2495 len -= 4;
2496
2497 while (len) {
2498 u_int aflags, alenlen, alen;
2499
2500 ND_TCHECK_2(tptr);
2501 if (len < 2) {
2502 ND_PRINT(" [path attr too short]");
2503 tptr += len;
2504 break;
2505 }
2506 aflags = GET_U_1(tptr);
2507 atype = GET_U_1(tptr + 1);
2508 tptr += 2;
2509 len -= 2;
2510 alenlen = bgp_attr_lenlen(aflags, tptr);
2511 ND_TCHECK_LEN(tptr, alenlen);
2512 if (len < alenlen) {
2513 ND_PRINT(" [path attr too short]");
2514 tptr += len;
2515 break;
2516 }
2517 alen = bgp_attr_len(aflags, tptr);
2518 tptr += alenlen;
2519 len -= alenlen;
2520
2521 ND_PRINT("\n\t %s (%u), length: %u",
2522 tok2str(bgp_attr_values,
2523 "Unknown Attribute", atype),
2524 atype,
2525 alen);
2526
2527 if (aflags) {
2528 ND_PRINT(", Flags [%s%s%s%s",
2529 aflags & 0x80 ? "O" : "",
2530 aflags & 0x40 ? "T" : "",
2531 aflags & 0x20 ? "P" : "",
2532 aflags & 0x10 ? "E" : "");
2533 if (aflags & 0xf)
2534 ND_PRINT("+%x", aflags & 0xf);
2535 ND_PRINT("]");
2536 }
2537 ND_PRINT(": ");
2538 if (len < alen) {
2539 ND_PRINT(" [path attr too short]");
2540 tptr += len;
2541 break;
2542 }
2543 /*
2544 * The protocol encoding per se allows ATTR_SET to be nested
2545 * as many times as the message can accommodate. This printer
2546 * used to be able to recurse into ATTR_SET contents until the
2547 * stack exhaustion, but now there is a limit on that (if live
2548 * protocol exchange goes that many levels deep, something is
2549 * probably wrong anyway). Feel free to refine this value if
2550 * you can find the spec with respective normative text.
2551 */
2552 if (attr_set_level == 10)
2553 ND_PRINT("(too many nested levels, not recursing)");
2554 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2555 return 0;
2556 tptr += alen;
2557 len -= alen;
2558 }
2559 break;
2560
2561 case BGPTYPE_LARGE_COMMUNITY:
2562 if (len == 0 || len % 12) {
2563 ND_PRINT("invalid len");
2564 break;
2565 }
2566 ND_PRINT("\n\t ");
2567 while (len != 0) {
2568 ND_TCHECK_LEN(tptr, 12);
2569 ND_PRINT("%u:%u:%u%s",
2570 GET_BE_U_4(tptr),
2571 GET_BE_U_4(tptr + 4),
2572 GET_BE_U_4(tptr + 8),
2573 (len > 12) ? ", " : "");
2574 tptr += 12;
2575 /*
2576 * len will always be a multiple of 12, as per the above,
2577 * so this will never underflow.
2578 */
2579 len -= 12;
2580 }
2581 break;
2582 default:
2583 ND_TCHECK_LEN(pptr, len);
2584 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2585 if (ndo->ndo_vflag <= 1)
2586 print_unknown_data(ndo, pptr, "\n\t ", len);
2587 break;
2588 }
2589 done:
2590 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2591 ND_TCHECK_LEN(pptr, len);
2592 print_unknown_data(ndo, pptr, "\n\t ", len);
2593 }
2594 return 1;
2595
2596 trunc:
2597 return 0;
2598 }
2599
2600 static void
2601 bgp_capabilities_print(netdissect_options *ndo,
2602 const u_char *opt, u_int caps_len)
2603 {
2604 u_int cap_type, cap_len, tcap_len, cap_offset;
2605 u_int i = 0;
2606
2607 while (i < caps_len) {
2608 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2609 cap_type=GET_U_1(opt + i);
2610 cap_len=GET_U_1(opt + i + 1);
2611 ND_PRINT("\n\t %s (%u), length: %u",
2612 tok2str(bgp_capcode_values, "Unknown", cap_type),
2613 cap_type,
2614 cap_len);
2615 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2616 switch (cap_type) {
2617 case BGP_CAPCODE_MP:
2618 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2619 if (cap_len < 4) {
2620 ND_PRINT(" (too short, < 4)");
2621 return;
2622 }
2623 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2624 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2625 GET_BE_U_2(opt + i + 2),
2626 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2627 GET_U_1(opt + i + 5));
2628 break;
2629 case BGP_CAPCODE_ML:
2630 cap_offset = 2;
2631 tcap_len = cap_len;
2632 while (tcap_len >= 4) {
2633 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2634 tok2str(af_values, "Unknown",
2635 GET_BE_U_2(opt + i + cap_offset)),
2636 GET_BE_U_2(opt + i + cap_offset),
2637 tok2str(bgp_safi_values, "Unknown",
2638 GET_U_1(opt + i + cap_offset + 2)),
2639 GET_U_1(opt + i + cap_offset + 2),
2640 GET_U_1(opt + i + cap_offset + 3));
2641 tcap_len -= 4;
2642 cap_offset += 4;
2643 }
2644 break;
2645 case BGP_CAPCODE_RESTART:
2646 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2647 if (cap_len < 2) {
2648 ND_PRINT(" (too short, < 2)");
2649 return;
2650 }
2651 tcap_len=cap_len;
2652 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2653 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2654 GET_BE_U_2(opt + i + 2)&0xfff);
2655 tcap_len-=2;
2656 cap_offset=4;
2657 while(tcap_len>=4) {
2658 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2659 tok2str(af_values,"Unknown",
2660 GET_BE_U_2(opt + i + cap_offset)),
2661 GET_BE_U_2(opt + i + cap_offset),
2662 tok2str(bgp_safi_values,"Unknown",
2663 GET_U_1(opt + i + cap_offset + 2)),
2664 GET_U_1(opt + (i + cap_offset + 2)),
2665 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2666 tcap_len -= 4;
2667 cap_offset += 4;
2668 }
2669 break;
2670 case BGP_CAPCODE_RR:
2671 case BGP_CAPCODE_LLGR:
2672 case BGP_CAPCODE_RR_CISCO:
2673 break;
2674 case BGP_CAPCODE_AS_NEW:
2675 /*
2676 * Extract the 4 byte AS number encoded.
2677 */
2678 if (cap_len < 4) {
2679 ND_PRINT(" (too short, < 4)");
2680 return;
2681 }
2682 ND_PRINT("\n\t\t 4 Byte AS %s",
2683 as_printf(ndo, astostr, sizeof(astostr),
2684 GET_BE_U_4(opt + i + 2)));
2685 break;
2686 case BGP_CAPCODE_ADD_PATH:
2687 if (cap_len == 0) {
2688 ND_PRINT(" (bogus)"); /* length */
2689 break;
2690 }
2691 tcap_len=cap_len;
2692 cap_offset=2;
2693 while (tcap_len != 0) {
2694 if (tcap_len < 4) {
2695 nd_print_invalid(ndo);
2696 break;
2697 }
2698 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2699 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2700 GET_BE_U_2(opt + i + cap_offset),
2701 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2702 GET_U_1(opt + (i + cap_offset + 2)),
2703 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2704 );
2705 tcap_len -= 4;
2706 cap_offset += 4;
2707 }
2708 break;
2709 default:
2710 ND_PRINT("\n\t\tno decoder for Capability %u",
2711 cap_type);
2712 if (ndo->ndo_vflag <= 1)
2713 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2714 cap_len);
2715 break;
2716 }
2717 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2718 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2719 }
2720 i += BGP_CAP_HEADER_SIZE + cap_len;
2721 }
2722 return;
2723
2724 trunc:
2725 nd_print_trunc(ndo);
2726 }
2727
2728 static void
2729 bgp_open_print(netdissect_options *ndo,
2730 const u_char *dat, u_int length)
2731 {
2732 const struct bgp_open *bgp_open_header;
2733 u_int optslen;
2734 const struct bgp_opt *bgpopt;
2735 const u_char *opt;
2736 u_int i;
2737
2738 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2739 if (length < BGP_OPEN_SIZE)
2740 goto trunc;
2741
2742 bgp_open_header = (const struct bgp_open *)dat;
2743
2744 ND_PRINT("\n\t Version %u, ",
2745 GET_U_1(bgp_open_header->bgpo_version));
2746 ND_PRINT("my AS %s, ",
2747 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2748 ND_PRINT("Holdtime %us, ",
2749 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2750 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2751 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2752 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2753
2754 opt = dat + BGP_OPEN_SIZE;
2755 length -= BGP_OPEN_SIZE;
2756
2757 i = 0;
2758 while (i < optslen) {
2759 uint8_t opt_type, opt_len;
2760
2761 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2762 if (length < BGP_OPT_SIZE + i)
2763 goto trunc;
2764 bgpopt = (const struct bgp_opt *)(opt + i);
2765 opt_type = GET_U_1(bgpopt->bgpopt_type);
2766 opt_len = GET_U_1(bgpopt->bgpopt_len);
2767 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2768 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2769 opt_type, opt_len);
2770 break;
2771 }
2772
2773 ND_PRINT("\n\t Option %s (%u), length: %u",
2774 tok2str(bgp_opt_values,"Unknown",opt_type),
2775 opt_type,
2776 opt_len);
2777
2778 /* now let's decode the options we know*/
2779 switch(opt_type) {
2780
2781 case BGP_OPT_CAP:
2782 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2783 opt_len);
2784 break;
2785
2786 case BGP_OPT_AUTH:
2787 default:
2788 ND_PRINT("\n\t no decoder for option %u",
2789 opt_type);
2790 break;
2791 }
2792 i += BGP_OPT_SIZE + opt_len;
2793 }
2794 return;
2795 trunc:
2796 nd_print_trunc(ndo);
2797 }
2798
2799 static void
2800 bgp_update_print(netdissect_options *ndo,
2801 const u_char *dat, u_int length)
2802 {
2803 const u_char *p;
2804 u_int withdrawn_routes_len;
2805 char buf[MAXHOSTNAMELEN + 100];
2806 int wpfx;
2807 u_int len;
2808 int i;
2809 int add_path;
2810 u_int path_id = 0;
2811
2812 ND_TCHECK_LEN(dat, BGP_SIZE);
2813 if (length < BGP_SIZE)
2814 goto trunc;
2815 p = dat + BGP_SIZE;
2816 length -= BGP_SIZE;
2817
2818 /* Unfeasible routes */
2819 ND_TCHECK_2(p);
2820 if (length < 2)
2821 goto trunc;
2822 withdrawn_routes_len = GET_BE_U_2(p);
2823 p += 2;
2824 length -= 2;
2825 if (withdrawn_routes_len > 1) {
2826 /*
2827 * Without keeping state from the original NLRI message,
2828 * it's not possible to tell if this a v4 or v6 route,
2829 * so only try to decode it if we're not v6 enabled.
2830 */
2831 ND_TCHECK_LEN(p, withdrawn_routes_len);
2832 if (length < withdrawn_routes_len)
2833 goto trunc;
2834 ND_PRINT("\n\t Withdrawn routes:");
2835 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2836 while (withdrawn_routes_len != 0) {
2837 if (add_path) {
2838 if (withdrawn_routes_len < 4) {
2839 p += withdrawn_routes_len;
2840 length -= withdrawn_routes_len;
2841 break;
2842 }
2843 path_id = GET_BE_U_4(p);
2844 p += 4;
2845 length -= 4;
2846 withdrawn_routes_len -= 4;
2847 }
2848 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2849 if (wpfx == -1) {
2850 ND_PRINT("\n\t (illegal prefix length)");
2851 break;
2852 } else if (wpfx == -2)
2853 goto trunc;
2854 else if (wpfx == -3)
2855 goto trunc; /* bytes left, but not enough */
2856 else {
2857 ND_PRINT("\n\t %s", buf);
2858 if (add_path) {
2859 ND_PRINT(" Path Id: %u", path_id);
2860 }
2861 p += wpfx;
2862 length -= wpfx;
2863 withdrawn_routes_len -= wpfx;
2864 }
2865 }
2866 } else {
2867 ND_TCHECK_LEN(p, withdrawn_routes_len);
2868 if (length < withdrawn_routes_len)
2869 goto trunc;
2870 p += withdrawn_routes_len;
2871 length -= withdrawn_routes_len;
2872 }
2873
2874 ND_TCHECK_2(p);
2875 if (length < 2)
2876 goto trunc;
2877 len = GET_BE_U_2(p);
2878 p += 2;
2879 length -= 2;
2880
2881 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2882 /* No withdrawn routes, no path attributes, no NLRI */
2883 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2884 return;
2885 }
2886
2887 if (len) {
2888 /* do something more useful!*/
2889 while (len) {
2890 uint8_t aflags, atype, alenlen;
2891 uint16_t alen;
2892
2893 ND_TCHECK_2(p);
2894 if (length < 2)
2895 goto trunc;
2896 if (len < 2) {
2897 ND_PRINT("\n\t [path attrs too short]");
2898 p += len;
2899 length -= len;
2900 break;
2901 }
2902 aflags = GET_U_1(p);
2903 atype = GET_U_1(p + 1);
2904 p += 2;
2905 len -= 2;
2906 length -= 2;
2907 alenlen = bgp_attr_lenlen(aflags, p);
2908 ND_TCHECK_LEN(p, alenlen);
2909 if (length < alenlen)
2910 goto trunc;
2911 if (len < alenlen) {
2912 ND_PRINT("\n\t [path attrs too short]");
2913 p += len;
2914 length -= len;
2915 break;
2916 }
2917 alen = bgp_attr_len(aflags, p);
2918 p += alenlen;
2919 len -= alenlen;
2920 length -= alenlen;
2921
2922 ND_PRINT("\n\t %s (%u), length: %u",
2923 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2924 atype,
2925 alen);
2926
2927 if (aflags) {
2928 ND_PRINT(", Flags [%s%s%s%s",
2929 aflags & 0x80 ? "O" : "",
2930 aflags & 0x40 ? "T" : "",
2931 aflags & 0x20 ? "P" : "",
2932 aflags & 0x10 ? "E" : "");
2933 if (aflags & 0xf)
2934 ND_PRINT("+%x", aflags & 0xf);
2935 ND_PRINT("]: ");
2936 }
2937 if (len < alen) {
2938 ND_PRINT(" [path attrs too short]");
2939 p += len;
2940 length -= len;
2941 break;
2942 }
2943 if (length < alen)
2944 goto trunc;
2945 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2946 goto trunc;
2947 p += alen;
2948 len -= alen;
2949 length -= alen;
2950 }
2951 }
2952
2953 if (length) {
2954 add_path = check_add_path(ndo, p, length, 32);
2955 ND_PRINT("\n\t Updated routes:");
2956 while (length != 0) {
2957 if (add_path) {
2958 ND_TCHECK_4(p);
2959 if (length < 4)
2960 goto trunc;
2961 path_id = GET_BE_U_4(p);
2962 p += 4;
2963 length -= 4;
2964 }
2965 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2966 if (i == -1) {
2967 ND_PRINT("\n\t (illegal prefix length)");
2968 break;
2969 } else if (i == -2)
2970 goto trunc;
2971 else if (i == -3)
2972 goto trunc; /* bytes left, but not enough */
2973 else {
2974 ND_PRINT("\n\t %s", buf);
2975 if (add_path) {
2976 ND_PRINT(" Path Id: %u", path_id);
2977 }
2978 p += i;
2979 length -= i;
2980 }
2981 }
2982 }
2983 return;
2984 trunc:
2985 nd_print_trunc(ndo);
2986 }
2987
2988 static void
2989 bgp_notification_print(netdissect_options *ndo,
2990 const u_char *dat, u_int length)
2991 {
2992 const struct bgp_notification *bgp_notification_header;
2993 const u_char *tptr;
2994 uint8_t bgpn_major, bgpn_minor;
2995 uint8_t shutdown_comm_length;
2996 uint8_t remainder_offset;
2997
2998 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2999 if (length<BGP_NOTIFICATION_SIZE)
3000 return;
3001
3002 bgp_notification_header = (const struct bgp_notification *)dat;
3003 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
3004 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
3005
3006 ND_PRINT(", %s (%u)",
3007 tok2str(bgp_notify_major_values, "Unknown Error",
3008 bgpn_major),
3009 bgpn_major);
3010
3011 switch (bgpn_major) {
3012
3013 case BGP_NOTIFY_MAJOR_MSG:
3014 ND_PRINT(", subcode %s (%u)",
3015 tok2str(bgp_notify_minor_msg_values, "Unknown",
3016 bgpn_minor),
3017 bgpn_minor);
3018 break;
3019 case BGP_NOTIFY_MAJOR_OPEN:
3020 ND_PRINT(", subcode %s (%u)",
3021 tok2str(bgp_notify_minor_open_values, "Unknown",
3022 bgpn_minor),
3023 bgpn_minor);
3024 break;
3025 case BGP_NOTIFY_MAJOR_UPDATE:
3026 ND_PRINT(", subcode %s (%u)",
3027 tok2str(bgp_notify_minor_update_values, "Unknown",
3028 bgpn_minor),
3029 bgpn_minor);
3030 break;
3031 case BGP_NOTIFY_MAJOR_FSM:
3032 ND_PRINT(" subcode %s (%u)",
3033 tok2str(bgp_notify_minor_fsm_values, "Unknown",
3034 bgpn_minor),
3035 bgpn_minor);
3036 break;
3037 case BGP_NOTIFY_MAJOR_CAP:
3038 ND_PRINT(" subcode %s (%u)",
3039 tok2str(bgp_notify_minor_cap_values, "Unknown",
3040 bgpn_minor),
3041 bgpn_minor);
3042 break;
3043 case BGP_NOTIFY_MAJOR_CEASE:
3044 ND_PRINT(", subcode %s (%u)",
3045 tok2str(bgp_notify_minor_cease_values, "Unknown",
3046 bgpn_minor),
3047 bgpn_minor);
3048
3049 /* draft-ietf-idr-cease-subcode-02 mentions optionally 7 bytes
3050 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
3051 */
3052 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
3053 tptr = dat + BGP_NOTIFICATION_SIZE;
3054 ND_TCHECK_7(tptr);
3055 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
3056 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
3057 GET_BE_U_2(tptr),
3058 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
3059 GET_U_1((tptr + 2)),
3060 GET_BE_U_4(tptr + 3));
3061 }
3062 /*
3063 * draft-ietf-idr-shutdown describes a method to send a communication
3064 * intended for human consumption regarding the Administrative Shutdown
3065 */
3066 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
3067 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
3068 length >= BGP_NOTIFICATION_SIZE + 1) {
3069 tptr = dat + BGP_NOTIFICATION_SIZE;
3070 ND_TCHECK_1(tptr);
3071 shutdown_comm_length = GET_U_1(tptr);
3072 remainder_offset = 0;
3073 /* garbage, hexdump it all */
3074 if (shutdown_comm_length > BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN ||
3075 shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
3076 ND_PRINT(", invalid Shutdown Communication length");
3077 }
3078 else if (shutdown_comm_length == 0) {
3079 ND_PRINT(", empty Shutdown Communication");
3080 remainder_offset += 1;
3081 }
3082 /* a proper shutdown communication */
3083 else {
3084 ND_TCHECK_LEN(tptr + 1, shutdown_comm_length);
3085 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3086 (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL);
3087 ND_PRINT("\"");
3088 remainder_offset += shutdown_comm_length + 1;
3089 }
3090 /* if there is trailing data, hexdump it */
3091 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3092 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3093 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3094 }
3095 }
3096 break;
3097 default:
3098 break;
3099 }
3100
3101 return;
3102 trunc:
3103 nd_print_trunc(ndo);
3104 }
3105
3106 static void
3107 bgp_route_refresh_print(netdissect_options *ndo,
3108 const u_char *pptr, u_int len)
3109 {
3110 const struct bgp_route_refresh *bgp_route_refresh_header;
3111
3112 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3113
3114 /* some little sanity checking */
3115 if (len<BGP_ROUTE_REFRESH_SIZE)
3116 return;
3117
3118 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3119
3120 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3121 tok2str(af_values,"Unknown",
3122 GET_BE_U_2(bgp_route_refresh_header->afi)),
3123 GET_BE_U_2(bgp_route_refresh_header->afi),
3124 tok2str(bgp_safi_values,"Unknown",
3125 GET_U_1(bgp_route_refresh_header->safi)),
3126 GET_U_1(bgp_route_refresh_header->safi));
3127
3128 if (ndo->ndo_vflag > 1) {
3129 ND_TCHECK_LEN(pptr, len);
3130 print_unknown_data(ndo, pptr, "\n\t ", len);
3131 }
3132
3133 return;
3134 trunc:
3135 nd_print_trunc(ndo);
3136 }
3137
3138 static int
3139 bgp_pdu_print(netdissect_options *ndo,
3140 const u_char *dat, u_int length)
3141 {
3142 const struct bgp *bgp_header;
3143 uint8_t bgp_type;
3144
3145 ND_TCHECK_LEN(dat, BGP_SIZE);
3146 bgp_header = (const struct bgp *)dat;
3147 bgp_type = GET_U_1(bgp_header->bgp_type);
3148
3149 ND_PRINT("\n\t%s Message (%u), length: %u",
3150 tok2str(bgp_msg_values, "Unknown", bgp_type),
3151 bgp_type,
3152 length);
3153
3154 switch (bgp_type) {
3155 case BGP_OPEN:
3156 bgp_open_print(ndo, dat, length);
3157 break;
3158 case BGP_UPDATE:
3159 bgp_update_print(ndo, dat, length);
3160 break;
3161 case BGP_NOTIFICATION:
3162 bgp_notification_print(ndo, dat, length);
3163 break;
3164 case BGP_KEEPALIVE:
3165 break;
3166 case BGP_ROUTE_REFRESH:
3167 bgp_route_refresh_print(ndo, dat, length);
3168 break;
3169 default:
3170 /* we have no decoder for the BGP message */
3171 ND_TCHECK_LEN(dat, length);
3172 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3173 print_unknown_data(ndo, dat, "\n\t ", length);
3174 break;
3175 }
3176 return 1;
3177 trunc:
3178 nd_print_trunc(ndo);
3179 return 0;
3180 }
3181
3182 void
3183 bgp_print(netdissect_options *ndo,
3184 const u_char *dat, u_int length _U_)
3185 {
3186 const u_char *p;
3187 const u_char *ep = ndo->ndo_snapend;
3188 const u_char *start;
3189 const u_char marker[] = {
3190 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3191 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3192 };
3193 const struct bgp *bgp_header;
3194 uint16_t hlen;
3195
3196 ndo->ndo_protocol = "bgp";
3197 ND_PRINT(": BGP");
3198
3199 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3200 return;
3201
3202 p = dat;
3203 start = p;
3204 while (p < ep) {
3205 if (!ND_TTEST_1(p))
3206 break;
3207 if (GET_U_1(p) != 0xff) {
3208 p++;
3209 continue;
3210 }
3211
3212 if (!ND_TTEST_LEN(p, sizeof(marker)))
3213 break;
3214 if (memcmp(p, marker, sizeof(marker)) != 0) {
3215 p++;
3216 continue;
3217 }
3218
3219 /* found BGP header */
3220 ND_TCHECK_LEN(p, BGP_SIZE);
3221 bgp_header = (const struct bgp *)p;
3222
3223 if (start != p)
3224 nd_print_trunc(ndo);
3225
3226 hlen = GET_BE_U_2(bgp_header->bgp_len);
3227 if (hlen < BGP_SIZE) {
3228 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3229 nd_print_invalid(ndo);
3230 break;
3231 }
3232
3233 if (ND_TTEST_LEN(p, hlen)) {
3234 if (!bgp_pdu_print(ndo, p, hlen))
3235 return;
3236 p += hlen;
3237 start = p;
3238 } else {
3239 ND_PRINT("\n[|BGP %s]",
3240 tok2str(bgp_msg_values,
3241 "Unknown Message Type",
3242 GET_U_1(bgp_header->bgp_type)));
3243 break;
3244 }
3245 }
3246
3247 return;
3248
3249 trunc:
3250 nd_print_trunc(ndo);
3251 }
[mirror] the TCPdump network dissector