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Use more the ND_TCHECK_1() macro
[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 #define AS_STR_SIZE sizeof("xxxxx.xxxxx")
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 ITEMCHECK(1);
593 plen = GET_U_1(pptr);
594 if (32 < plen)
595 return -1;
596 itemlen -= 1;
597
598 memset(&addr, 0, sizeof(addr));
599 plenbytes = (plen + 7) / 8;
600 ITEMCHECK(plenbytes);
601 GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
602 if (plen % 8) {
603 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
604 }
605 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
606 return 1 + plenbytes;
607
608 badtlv:
609 return -2;
610 }
611
612 static int
613 decode_labeled_prefix4(netdissect_options *ndo,
614 const u_char *pptr, u_int itemlen, char *buf,
615 size_t buflen)
616 {
617 nd_ipv4 addr;
618 u_int plen, plenbytes;
619
620 /* prefix length and label = 4 bytes */
621 ND_TCHECK_4(pptr);
622 ITEMCHECK(4);
623 plen = GET_U_1(pptr); /* get prefix length */
624
625 /* this is one of the weirdnesses of rfc3107
626 the label length (actually the label + COS bits)
627 is added to the prefix length;
628 we also do only read out just one label -
629 there is no real application for advertisement of
630 stacked labels in a single BGP message
631 */
632
633 if (24 > plen)
634 return -1;
635
636 plen-=24; /* adjust prefixlen - labellength */
637
638 if (32 < plen)
639 return -1;
640 itemlen -= 4;
641
642 memset(&addr, 0, sizeof(addr));
643 plenbytes = (plen + 7) / 8;
644 ITEMCHECK(plenbytes);
645 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
646 if (plen % 8) {
647 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
648 }
649 /* the label may get offsetted by 4 bits so lets shift it right */
650 snprintf(buf, buflen, "%s/%u, label:%u %s",
651 ipaddr_string(ndo, (const u_char *)&addr),
652 plen,
653 GET_BE_U_3(pptr + 1)>>4,
654 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
655
656 return 4 + plenbytes;
657
658 trunc:
659 return -2;
660
661 badtlv:
662 return -3;
663 }
664
665 /*
666 * bgp_vpn_ip_print
667 *
668 * print an ipv4 or ipv6 address into a buffer dependent on address length.
669 */
670 static char *
671 bgp_vpn_ip_print(netdissect_options *ndo,
672 const u_char *pptr, u_int addr_length)
673 {
674
675 /* worst case string is s fully formatted v6 address */
676 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
677 char *pos = addr;
678
679 switch(addr_length) {
680 case (sizeof(nd_ipv4) << 3): /* 32 */
681 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
682 break;
683 case (sizeof(nd_ipv6) << 3): /* 128 */
684 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
685 break;
686 default:
687 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
688 break;
689 }
690 pos += strlen(pos);
691
692 *(pos) = '\0';
693 return (addr);
694 }
695
696 /*
697 * bgp_vpn_sg_print
698 *
699 * print an multicast s,g entry into a buffer.
700 * the s,g entry is encoded like this.
701 *
702 * +-----------------------------------+
703 * | Multicast Source Length (1 octet) |
704 * +-----------------------------------+
705 * | Multicast Source (Variable) |
706 * +-----------------------------------+
707 * | Multicast Group Length (1 octet) |
708 * +-----------------------------------+
709 * | Multicast Group (Variable) |
710 * +-----------------------------------+
711 *
712 * return the number of bytes read from the wire.
713 */
714 static u_int
715 bgp_vpn_sg_print(netdissect_options *ndo,
716 const u_char *pptr, char *buf, size_t buflen)
717 {
718 uint8_t addr_length;
719 u_int total_length, offset;
720
721 total_length = 0;
722
723 /* Source address length, encoded in bits */
724 addr_length = GET_U_1(pptr);
725 pptr++;
726
727 /* Source address */
728 ND_TCHECK_LEN(pptr, (addr_length >> 3));
729 total_length += (addr_length >> 3) + 1;
730 offset = (u_int)strlen(buf);
731 if (addr_length) {
732 snprintf(buf + offset, buflen - offset, ", Source %s",
733 bgp_vpn_ip_print(ndo, pptr, addr_length));
734 pptr += (addr_length >> 3);
735 }
736
737 /* Group address length, encoded in bits */
738 addr_length = GET_U_1(pptr);
739 pptr++;
740
741 /* Group address */
742 ND_TCHECK_LEN(pptr, (addr_length >> 3));
743 total_length += (addr_length >> 3) + 1;
744 offset = (u_int)strlen(buf);
745 if (addr_length) {
746 snprintf(buf + offset, buflen - offset, ", Group %s",
747 bgp_vpn_ip_print(ndo, pptr, addr_length));
748 pptr += (addr_length >> 3);
749 }
750
751 trunc:
752 return (total_length);
753 }
754
755 /* Print an RFC 4364 Route Distinguisher */
756 const char *
757 bgp_vpn_rd_print(netdissect_options *ndo,
758 const u_char *pptr)
759 {
760 /* allocate space for the largest possible string */
761 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
762 char *pos = rd;
763 /* allocate space for the largest possible string */
764 char astostr[AS_STR_SIZE];
765
766 /* ok lets load the RD format */
767 switch (GET_BE_U_2(pptr)) {
768
769 case 0:
770 /* 2-byte-AS:number fmt */
771 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
772 GET_BE_U_2(pptr + 2),
773 GET_BE_U_4(pptr + 4),
774 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
775 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
776 break;
777
778 case 1:
779 /* IP-address:AS fmt */
780 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
781 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
782 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
783 GET_BE_U_2(pptr + 6));
784 break;
785
786 case 2:
787 /* 4-byte-AS:number fmt */
788 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
789 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
790 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
791 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
792 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
793 break;
794 default:
795 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
796 break;
797 }
798 pos += strlen(pos);
799 *(pos) = '\0';
800 return (rd);
801 }
802
803 /*
804 * Print an RFC 4360 Extended Community.
805 */
806 static void
807 bgp_extended_community_print(netdissect_options *ndo,
808 const u_char *pptr)
809 {
810 union { /* copy buffer for bandwidth values */
811 float f;
812 uint32_t i;
813 } bw;
814 /* allocate space for the largest possible string */
815 char astostr[AS_STR_SIZE];
816
817 switch (GET_BE_U_2(pptr)) {
818
819 case BGP_EXT_COM_RT_0:
820 case BGP_EXT_COM_RO_0:
821 case BGP_EXT_COM_L2VPN_RT_0:
822 ND_PRINT("%u:%u (= %s)",
823 GET_BE_U_2(pptr + 2),
824 GET_BE_U_4(pptr + 4),
825 GET_IPADDR_STRING(pptr+4));
826 break;
827
828 case BGP_EXT_COM_RT_1:
829 case BGP_EXT_COM_RO_1:
830 case BGP_EXT_COM_L2VPN_RT_1:
831 case BGP_EXT_COM_VRF_RT_IMP:
832 ND_PRINT("%s:%u",
833 GET_IPADDR_STRING(pptr+2),
834 GET_BE_U_2(pptr + 6));
835 break;
836
837 case BGP_EXT_COM_RT_2:
838 case BGP_EXT_COM_RO_2:
839 ND_PRINT("%s:%u",
840 as_printf(ndo, astostr, sizeof(astostr),
841 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
842 break;
843
844 case BGP_EXT_COM_LINKBAND:
845 bw.i = GET_BE_U_4(pptr + 2);
846 ND_PRINT("bandwidth: %.3f Mbps",
847 bw.f*8/1000000);
848 break;
849
850 case BGP_EXT_COM_VPN_ORIGIN:
851 case BGP_EXT_COM_VPN_ORIGIN2:
852 case BGP_EXT_COM_VPN_ORIGIN3:
853 case BGP_EXT_COM_VPN_ORIGIN4:
854 case BGP_EXT_COM_OSPF_RID:
855 case BGP_EXT_COM_OSPF_RID2:
856 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
857 break;
858
859 case BGP_EXT_COM_OSPF_RTYPE:
860 case BGP_EXT_COM_OSPF_RTYPE2:
861 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
862 GET_IPADDR_STRING(pptr+2),
863 tok2str(bgp_extd_comm_ospf_rtype_values,
864 "unknown (0x%02x)",
865 GET_U_1((pptr + 6))),
866 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
867 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
868 break;
869
870 case BGP_EXT_COM_L2INFO:
871 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
872 tok2str(l2vpn_encaps_values,
873 "unknown encaps",
874 GET_U_1((pptr + 2))),
875 GET_U_1((pptr + 3)),
876 GET_BE_U_2(pptr + 4));
877 break;
878
879 case BGP_EXT_COM_SOURCE_AS:
880 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
881 break;
882
883 case BGP_EXT_COM_ENCAP:
884 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
885 "unknown encaps",
886 GET_BE_U_2(pptr + 6)));
887 break;
888
889 default:
890 ND_PRINT("%02x%02x%02x%02x%02x%02x",
891 GET_U_1(pptr + 2),
892 GET_U_1(pptr + 3),
893 GET_U_1(pptr + 4),
894 GET_U_1(pptr + 5),
895 GET_U_1(pptr + 6),
896 GET_U_1(pptr + 7));
897 break;
898 }
899 }
900
901 /*
902 * RFC4684 (Section 4)/RFC2858 (Section 4).
903 * RTC membership prefix is structured as follows
904 * [prefix-len] [origin-as] [route-target]
905 * The route-target is encoded as RT ext-comms.
906 * Prefix-len may be 0, 32..96
907 *
908 * Note that pptr is not packet data - it is
909 * a buffer owned by our caller - therefore GET_*
910 * macros can not be used.
911 */
912 static char *
913 bgp_rt_prefix_print(netdissect_options *ndo,
914 const u_char *pptr,
915 u_int plen)
916 {
917 /* allocate space for the largest possible string */
918 char rtc_prefix_in_hex[20] = "";
919 u_int rtc_prefix_in_hex_len = 0;
920 static char output[61]; /* max response string */
921 /* allocate space for the largest possible string */
922 char astostr[AS_STR_SIZE];
923 uint16_t ec_type = 0;
924 u_int octet_count;
925 u_int i;
926
927 if (plen == 0) {
928 snprintf(output, sizeof(output), "route-target: 0:0/0");
929 return (output);
930 }
931
932 /* hex representation of the prefix */
933 octet_count = (plen+7)/8;
934 for (i=0; i<octet_count; i++) {
935 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
936 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
937 "%02x%s", *(pptr+i),
938 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
939 }
940
941 if (plen < 16) {
942 /*
943 * The prefix is too short to include the full ext-comm type,
944 * so we have no way to parse it further.
945 */
946 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
947 rtc_prefix_in_hex, plen);
948 return (output);
949 }
950
951 /*
952 * get the ext-comm type
953 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
954 * hense EXTRACT_*() macros are safe.
955 */
956 ec_type = EXTRACT_BE_U_2(pptr);
957 switch (ec_type) {
958 case BGP_EXT_COM_RT_0:
959 /* 2-byte-AS:number fmt */
960 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
961 EXTRACT_BE_U_2(pptr+2),
962 EXTRACT_BE_U_4(pptr+4),
963 plen, rtc_prefix_in_hex);
964 break;
965
966 case BGP_EXT_COM_RT_1:
967 /* IP-address:AS fmt */
968 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
969 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
970 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
971 break;
972
973 case BGP_EXT_COM_RT_2:
974 /* 4-byte-AS:number fmt */
975 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
976 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
977 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
978 break;
979
980 default:
981 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
982 ec_type,
983 rtc_prefix_in_hex, plen);
984 break;
985 }
986 return (output);
987 }
988
989 /* RFC 4684 */
990 static int
991 decode_rt_routing_info(netdissect_options *ndo,
992 const u_char *pptr)
993 {
994 uint8_t route_target[8];
995 u_int plen;
996 /* allocate space for the largest possible string */
997 char astostr[AS_STR_SIZE];
998 u_int num_octets;
999
1000 /* NLRI "prefix length" from RFC 2858 Section 4. */
1001 plen = GET_U_1(pptr); /* get prefix length */
1002
1003 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1004 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1005 * target" fields inside the "prefix" depending on its length.
1006 */
1007 if (0 == plen) {
1008 /* Without "origin AS", without "route target". */
1009 ND_PRINT("\n\t default route target");
1010 return 1;
1011 }
1012
1013 if (32 > plen) {
1014 ND_PRINT("\n\t (illegal prefix length)");
1015 return -1;
1016 }
1017
1018 /* With at least "origin AS", possibly with "route target". */
1019 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
1020
1021 plen -= 32; /* adjust prefix length */
1022
1023 if (64 < plen) {
1024 ND_PRINT("\n\t (illegal prefix length)");
1025 return -1;
1026 }
1027
1028 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1029 * and gives the number of octets in the variable-length "route
1030 * target" field inside this NLRI "prefix". Look for it.
1031 */
1032 memset(&route_target, 0, sizeof(route_target));
1033 num_octets = (plen + 7) / 8;
1034 GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
1035 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1036 if (plen % 8) {
1037 ((u_char *)&route_target)[num_octets - 1] &=
1038 ((0xff00 >> (plen % 8)) & 0xff);
1039 }
1040 ND_PRINT("\n\t origin AS: %s, %s",
1041 astostr,
1042 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1043
1044 return 5 + num_octets;
1045 }
1046
1047 static int
1048 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1049 const u_char *pptr, char *buf, size_t buflen)
1050 {
1051 nd_ipv4 addr;
1052 u_int plen;
1053
1054 plen = GET_U_1(pptr); /* get prefix length */
1055
1056 if ((24+64) > plen)
1057 return -1;
1058
1059 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1060
1061 if (32 < plen)
1062 return -1;
1063
1064 memset(&addr, 0, sizeof(addr));
1065 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1066 if (plen % 8) {
1067 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1068 ((0xff00 >> (plen % 8)) & 0xff);
1069 }
1070 /* the label may get offsetted by 4 bits so lets shift it right */
1071 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1072 bgp_vpn_rd_print(ndo, pptr+4),
1073 ipaddr_string(ndo, (const u_char *)&addr),
1074 plen,
1075 GET_BE_U_3(pptr + 1)>>4,
1076 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1077
1078 return 12 + (plen + 7) / 8;
1079 }
1080
1081 /*
1082 * +-------------------------------+
1083 * | |
1084 * | RD:IPv4-address (12 octets) |
1085 * | |
1086 * +-------------------------------+
1087 * | MDT Group-address (4 octets) |
1088 * +-------------------------------+
1089 */
1090
1091 #define MDT_VPN_NLRI_LEN 16
1092
1093 static int
1094 decode_mdt_vpn_nlri(netdissect_options *ndo,
1095 const u_char *pptr, char *buf, size_t buflen)
1096 {
1097 const u_char *rd;
1098 const u_char *vpn_ip;
1099
1100 /* if the NLRI is not predefined length, quit.*/
1101 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1102 return -1;
1103 pptr++;
1104
1105 /* RD */
1106 ND_TCHECK_8(pptr);
1107 rd = pptr;
1108 pptr += 8;
1109
1110 /* IPv4 address */
1111 vpn_ip = pptr;
1112 pptr += sizeof(nd_ipv4);
1113
1114 /* MDT Group Address */
1115 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1116 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1117
1118 return MDT_VPN_NLRI_LEN + 1;
1119
1120 trunc:
1121 return -2;
1122 }
1123
1124 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1125 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1126 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1127 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1128 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1129 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1130 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1131
1132 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1133 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1134 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1135 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1136 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1137 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1138 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1139 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1140 { 0, NULL}
1141 };
1142
1143 static int
1144 decode_multicast_vpn(netdissect_options *ndo,
1145 const u_char *pptr, char *buf, size_t buflen)
1146 {
1147 /* allocate space for the largest possible string */
1148 char astostr[AS_STR_SIZE];
1149 uint8_t route_type, route_length;
1150 u_int addr_length, sg_length;
1151 u_int offset;
1152
1153 route_type = GET_U_1(pptr);
1154 pptr++;
1155 route_length = GET_U_1(pptr);
1156 pptr++;
1157
1158 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1159 tok2str(bgp_multicast_vpn_route_type_values,
1160 "Unknown", route_type),
1161 route_type, route_length);
1162
1163 switch(route_type) {
1164 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1165 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1166 offset = (u_int)strlen(buf);
1167 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1168 bgp_vpn_rd_print(ndo, pptr),
1169 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1170 (route_length - BGP_VPN_RD_LEN) << 3));
1171 break;
1172 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1173 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1174 offset = (u_int)strlen(buf);
1175 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1176 bgp_vpn_rd_print(ndo, pptr),
1177 as_printf(ndo, astostr, sizeof(astostr),
1178 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1179 break;
1180
1181 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1182 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1183 offset = (u_int)strlen(buf);
1184 snprintf(buf + offset, buflen - offset, ", RD: %s",
1185 bgp_vpn_rd_print(ndo, pptr));
1186 pptr += BGP_VPN_RD_LEN;
1187
1188 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1189 addr_length = route_length - sg_length;
1190
1191 ND_TCHECK_LEN(pptr, addr_length);
1192 offset = (u_int)strlen(buf);
1193 snprintf(buf + offset, buflen - offset, ", Originator %s",
1194 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1195 break;
1196
1197 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1198 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1199 offset = (u_int)strlen(buf);
1200 snprintf(buf + offset, buflen - offset, ", RD: %s",
1201 bgp_vpn_rd_print(ndo, pptr));
1202 pptr += BGP_VPN_RD_LEN;
1203
1204 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1205 break;
1206
1207 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1208 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1209 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1210 offset = (u_int)strlen(buf);
1211 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1212 bgp_vpn_rd_print(ndo, pptr),
1213 as_printf(ndo, astostr, sizeof(astostr),
1214 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1215 pptr += BGP_VPN_RD_LEN + 4;
1216
1217 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1218 break;
1219
1220 /*
1221 * no per route-type printing yet.
1222 */
1223 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1224 default:
1225 break;
1226 }
1227
1228 return route_length + 2;
1229
1230 trunc:
1231 return -2;
1232 }
1233
1234 /*
1235 * As I remember, some versions of systems have an snprintf() that
1236 * returns -1 if the buffer would have overflowed. If the return
1237 * value is negative, set buflen to 0, to indicate that we've filled
1238 * the buffer up.
1239 *
1240 * If the return value is greater than buflen, that means that
1241 * the buffer would have overflowed; again, set buflen to 0 in
1242 * that case.
1243 */
1244 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1245 if (stringlen<0) \
1246 buflen=0; \
1247 else if ((u_int)stringlen>buflen) \
1248 buflen=0; \
1249 else { \
1250 buflen-=stringlen; \
1251 buf+=stringlen; \
1252 }
1253
1254 static int
1255 decode_labeled_vpn_l2(netdissect_options *ndo,
1256 const u_char *pptr, char *buf, size_t buflen)
1257 {
1258 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1259 int stringlen;
1260
1261 plen = GET_BE_U_2(pptr);
1262 tlen = plen;
1263 pptr += 2;
1264 /* Old and new L2VPN NLRI share AFI/SAFI
1265 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1266 * and > 17 as old format. Complain for the middle case
1267 */
1268 if (plen == 12) {
1269 /* assume AD-only with RD, BGPNH */
1270 ND_TCHECK_LEN(pptr, 12);
1271 buf[0] = '\0';
1272 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1273 bgp_vpn_rd_print(ndo, pptr),
1274 GET_IPADDR_STRING(pptr+8));
1275 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1276 pptr += 12;
1277 tlen -= 12;
1278 return plen + 2;
1279 } else if (plen > 17) {
1280 /* assume old format */
1281 /* RD, ID, LBLKOFF, LBLBASE */
1282
1283 ND_TCHECK_LEN(pptr, 15);
1284 buf[0] = '\0';
1285 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1286 bgp_vpn_rd_print(ndo, pptr),
1287 GET_BE_U_2(pptr + 8),
1288 GET_BE_U_2(pptr + 10),
1289 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1290 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1291 pptr += 15;
1292 tlen -= 15;
1293
1294 /* ok now the variable part - lets read out TLVs*/
1295 while (tlen != 0) {
1296 if (tlen < 3) {
1297 if (buflen != 0) {
1298 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1299 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1300 }
1301 return plen + 2;
1302 }
1303 tlv_type = GET_U_1(pptr);
1304 pptr++;
1305 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1306 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1307 pptr += 2;
1308
1309 switch(tlv_type) {
1310 case 1:
1311 if (buflen != 0) {
1312 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1313 tlv_type,
1314 tlv_len);
1315 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1316 }
1317 while (ttlv_len != 0) {
1318 if (tlen < 1) {
1319 if (buflen != 0) {
1320 stringlen=snprintf(buf,buflen, " (ran past the end)");
1321 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1322 }
1323 return plen + 2;
1324 }
1325 ND_TCHECK_1(pptr);
1326 if (buflen != 0) {
1327 stringlen=snprintf(buf,buflen, "%02x",
1328 GET_U_1(pptr));
1329 pptr++;
1330 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1331 }
1332 ttlv_len--;
1333 tlen--;
1334 }
1335 break;
1336 default:
1337 if (buflen != 0) {
1338 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1339 tlv_type,
1340 tlv_len);
1341 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1342 }
1343 if (tlen < ttlv_len) {
1344 if (buflen != 0) {
1345 stringlen=snprintf(buf,buflen, " (ran past the end)");
1346 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1347 }
1348 return plen + 2;
1349 }
1350 tlen -= ttlv_len;
1351 break;
1352 }
1353 }
1354 return plen + 2;
1355 } else {
1356 /* complain bitterly ? */
1357 /* fall through */
1358 goto trunc;
1359 }
1360
1361 trunc:
1362 return -2;
1363 }
1364
1365 int
1366 decode_prefix6(netdissect_options *ndo,
1367 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1368 {
1369 nd_ipv6 addr;
1370 u_int plen, plenbytes;
1371
1372 ITEMCHECK(1);
1373 plen = GET_U_1(pd);
1374 if (128 < plen)
1375 return -1;
1376 itemlen -= 1;
1377
1378 memset(&addr, 0, sizeof(addr));
1379 plenbytes = (plen + 7) / 8;
1380 ITEMCHECK(plenbytes);
1381 GET_CPY_BYTES(&addr, pd + 1, plenbytes);
1382 if (plen % 8) {
1383 addr[plenbytes - 1] &=
1384 ((0xff00 >> (plen % 8)) & 0xff);
1385 }
1386 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1387 return 1 + plenbytes;
1388
1389 badtlv:
1390 return -2;
1391 }
1392
1393 static int
1394 decode_labeled_prefix6(netdissect_options *ndo,
1395 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1396 {
1397 nd_ipv6 addr;
1398 u_int plen, plenbytes;
1399
1400 /* prefix length and label = 4 bytes */
1401 ND_TCHECK_4(pptr);
1402 ITEMCHECK(4);
1403 plen = GET_U_1(pptr); /* get prefix length */
1404
1405 if (24 > plen)
1406 return -1;
1407
1408 plen -= 24; /* adjust prefixlen - labellength */
1409
1410 if (128 < plen)
1411 return -1;
1412 itemlen -= 4;
1413
1414 memset(&addr, 0, sizeof(addr));
1415 plenbytes = (plen + 7) / 8;
1416 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
1417 if (plen % 8) {
1418 addr[plenbytes - 1] &=
1419 ((0xff00 >> (plen % 8)) & 0xff);
1420 }
1421 /* the label may get offsetted by 4 bits so lets shift it right */
1422 snprintf(buf, buflen, "%s/%u, label:%u %s",
1423 ip6addr_string(ndo, (const u_char *)&addr),
1424 plen,
1425 GET_BE_U_3(pptr + 1)>>4,
1426 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1427
1428 return 4 + plenbytes;
1429
1430 trunc:
1431 return -2;
1432
1433 badtlv:
1434 return -3;
1435 }
1436
1437 static int
1438 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1439 const u_char *pptr, char *buf, size_t buflen)
1440 {
1441 nd_ipv6 addr;
1442 u_int plen;
1443
1444 plen = GET_U_1(pptr); /* get prefix length */
1445
1446 if ((24+64) > plen)
1447 return -1;
1448
1449 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1450
1451 if (128 < plen)
1452 return -1;
1453
1454 memset(&addr, 0, sizeof(addr));
1455 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1456 if (plen % 8) {
1457 addr[(plen + 7) / 8 - 1] &=
1458 ((0xff00 >> (plen % 8)) & 0xff);
1459 }
1460 /* the label may get offsetted by 4 bits so lets shift it right */
1461 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1462 bgp_vpn_rd_print(ndo, pptr+4),
1463 ip6addr_string(ndo, (const u_char *)&addr),
1464 plen,
1465 GET_BE_U_3(pptr + 1)>>4,
1466 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1467
1468 return 12 + (plen + 7) / 8;
1469 }
1470
1471 static int
1472 decode_clnp_prefix(netdissect_options *ndo,
1473 const u_char *pptr, char *buf, size_t buflen)
1474 {
1475 uint8_t addr[19];
1476 u_int plen;
1477
1478 plen = GET_U_1(pptr); /* get prefix length */
1479
1480 if (152 < plen)
1481 return -1;
1482
1483 memset(&addr, 0, sizeof(addr));
1484 GET_CPY_BYTES(&addr, pptr + 4, (plen + 7) / 8);
1485 if (plen % 8) {
1486 addr[(plen + 7) / 8 - 1] &=
1487 ((0xff00 >> (plen % 8)) & 0xff);
1488 }
1489 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1490 snprintf(buf, buflen, "%s/%u",
1491 isonsap_string(ndo, addr,(plen + 7) / 8),
1492 plen);
1493
1494 return 1 + (plen + 7) / 8;
1495 }
1496
1497 static int
1498 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1499 const u_char *pptr, char *buf, size_t buflen)
1500 {
1501 uint8_t addr[19];
1502 u_int plen;
1503
1504 plen = GET_U_1(pptr); /* get prefix length */
1505
1506 if ((24+64) > plen)
1507 return -1;
1508
1509 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1510
1511 if (152 < plen)
1512 return -1;
1513
1514 memset(&addr, 0, sizeof(addr));
1515 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1516 if (plen % 8) {
1517 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1518 }
1519 /* the label may get offsetted by 4 bits so lets shift it right */
1520 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1521 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1522 bgp_vpn_rd_print(ndo, pptr+4),
1523 isonsap_string(ndo, addr,(plen + 7) / 8),
1524 plen,
1525 GET_BE_U_3(pptr + 1)>>4,
1526 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1527
1528 return 12 + (plen + 7) / 8;
1529 }
1530
1531 /*
1532 * bgp_attr_get_as_size
1533 *
1534 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1535 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1536 * support, exchange AS-Path with the same path-attribute type value 0x02.
1537 */
1538 static u_int
1539 bgp_attr_get_as_size(netdissect_options *ndo,
1540 uint8_t bgpa_type, const u_char *pptr, u_int len)
1541 {
1542 const u_char *tptr = pptr;
1543
1544 /*
1545 * If the path attribute is the optional AS4 path type, then we already
1546 * know, that ASs must be encoded in 4 byte format.
1547 */
1548 if (bgpa_type == BGPTYPE_AS4_PATH) {
1549 return 4;
1550 }
1551
1552 /*
1553 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1554 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1555 * each.
1556 */
1557 while (tptr < pptr + len) {
1558 /*
1559 * If we do not find a valid segment type, our guess might be wrong.
1560 */
1561 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1562 goto trunc;
1563 }
1564 tptr += 2 + GET_U_1(tptr + 1) * 2;
1565 }
1566
1567 /*
1568 * If we correctly reached end of the AS path attribute data content,
1569 * then most likely ASs were indeed encoded as 2 bytes.
1570 */
1571 if (tptr == pptr + len) {
1572 return 2;
1573 }
1574
1575 trunc:
1576
1577 /*
1578 * We can come here, either we did not have enough data, or if we
1579 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1580 * so that calller can try to decode each AS as of 4 bytes. If indeed
1581 * there was not enough data, it will crib and end the parse anyways.
1582 */
1583 return 4;
1584 }
1585
1586 /*
1587 * The only way to know that a BGP UPDATE message is using add path is
1588 * by checking if the capability is in the OPEN message which we may have missed.
1589 * So this function checks if it is possible that the update could contain add path
1590 * and if so it checks that standard BGP doesn't make sense.
1591 */
1592 static int
1593 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1594 u_int max_prefix_length)
1595 {
1596 u_int offset, prefix_length;
1597
1598 if (length < 5) {
1599 return 0;
1600 }
1601
1602 /*
1603 * Scan through the NLRI information under the assumpetion that
1604 * it doesn't have path IDs.
1605 */
1606 for (offset = 0; offset < length;) {
1607 offset += 4;
1608 if (!ND_TTEST_1(pptr + offset)) {
1609 /* We ran out of captured data; quit scanning. */
1610 break;
1611 }
1612 prefix_length = GET_U_1(pptr + offset);
1613 /*
1614 * Add 4 to cover the path id
1615 * and check the prefix length isn't greater than 32/128.
1616 */
1617 if (prefix_length > max_prefix_length) {
1618 return 0;
1619 }
1620 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1621 offset += 1 + ((prefix_length + 7) / 8);
1622 }
1623 /* check we haven't gone past the end of the section */
1624 if (offset > length) {
1625 return 0;
1626 }
1627
1628 /* check it's not standard BGP */
1629 for (offset = 0; offset < length; ) {
1630 if (!ND_TTEST_1(pptr + offset)) {
1631 /* We ran out of captured data; quit scanning. */
1632 break;
1633 }
1634 prefix_length = GET_U_1(pptr + offset);
1635 /*
1636 * If the prefix_length is zero (0.0.0.0/0)
1637 * and since it's not the only address (length >= 5)
1638 * then it is add-path
1639 */
1640 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1641 return 1;
1642 }
1643 offset += 1 + ((prefix_length + 7) / 8);
1644 }
1645 if (offset > length) {
1646 return 1;
1647 }
1648
1649 /* assume not add-path by default */
1650 return 0;
1651 }
1652
1653 static int
1654 bgp_mp_af_print(netdissect_options *ndo,
1655 const u_char *tptr, u_int tlen,
1656 uint16_t *afp, uint8_t *safip)
1657 {
1658 uint16_t af;
1659 uint8_t safi;
1660
1661 af = GET_BE_U_2(tptr);
1662 *afp = af;
1663 safi = GET_U_1(tptr + 2);
1664 *safip = safi;
1665
1666 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1667 tok2str(af_values, "Unknown AFI", af),
1668 af,
1669 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1670 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1671 safi);
1672
1673 switch(af<<8 | safi) {
1674 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1675 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1676 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1677 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1678 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1679 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1680 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1681 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1682 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1683 case (AFNUM_INET<<8 | SAFNUM_MDT):
1684 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1685 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1686 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1687 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1688 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1689 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1690 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1691 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1692 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1693 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1694 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1695 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1696 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1697 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1698 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1699 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1700 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1701 break;
1702 default:
1703 ND_TCHECK_LEN(tptr, tlen);
1704 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1705 if (ndo->ndo_vflag <= 1)
1706 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1707 return -1;
1708 }
1709 return 0;
1710 trunc:
1711 return -2;
1712 }
1713
1714 static int
1715 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1716 const u_char *tptr, u_int len,
1717 char *buf, size_t buflen,
1718 int add_path4, int add_path6)
1719 {
1720 int advance;
1721 u_int path_id = 0;
1722
1723 switch (af<<8 | safi) {
1724 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1725 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1726 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1727 if (add_path4) {
1728 path_id = GET_BE_U_4(tptr);
1729 tptr += 4;
1730 }
1731 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1732 if (advance == -1)
1733 ND_PRINT("\n\t (illegal prefix length)");
1734 else if (advance == -2)
1735 break; /* bytes left, but not enough */
1736 else
1737 ND_PRINT("\n\t %s", buf);
1738 if (add_path4) {
1739 ND_PRINT(" Path Id: %u", path_id);
1740 advance += 4;
1741 }
1742 break;
1743 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1744 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1745 if (advance == -1)
1746 ND_PRINT("\n\t (illegal prefix length)");
1747 else if (advance == -2)
1748 goto trunc;
1749 else if (advance == -3)
1750 break; /* bytes left, but not enough */
1751 else
1752 ND_PRINT("\n\t %s", buf);
1753 break;
1754 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1755 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1756 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1757 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1758 if (advance == -1)
1759 ND_PRINT("\n\t (illegal prefix length)");
1760 else
1761 ND_PRINT("\n\t %s", buf);
1762 break;
1763 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1764 advance = decode_rt_routing_info(ndo, tptr);
1765 break;
1766 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1767 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1768 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1769 if (advance == -1)
1770 ND_PRINT("\n\t (illegal prefix length)");
1771 else if (advance == -2)
1772 goto trunc;
1773 else
1774 ND_PRINT("\n\t %s", buf);
1775 break;
1776
1777 case (AFNUM_INET<<8 | SAFNUM_MDT):
1778 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1779 if (advance == -1)
1780 ND_PRINT("\n\t (illegal prefix length)");
1781 else if (advance == -2)
1782 goto trunc;
1783 else
1784 ND_PRINT("\n\t %s", buf);
1785 break;
1786 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1787 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1788 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1789 if (add_path6) {
1790 path_id = GET_BE_U_4(tptr);
1791 tptr += 4;
1792 }
1793 advance = decode_prefix6(ndo, tptr, len, buf, buflen);
1794 if (advance == -1)
1795 ND_PRINT("\n\t (illegal prefix length)");
1796 else if (advance == -2)
1797 break; /* bytes left, but not enough */
1798 else
1799 ND_PRINT("\n\t %s", buf);
1800 if (add_path6) {
1801 ND_PRINT(" Path Id: %u", path_id);
1802 advance += 4;
1803 }
1804 break;
1805 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1806 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1807 if (advance == -1)
1808 ND_PRINT("\n\t (illegal prefix length)");
1809 else if (advance == -2)
1810 goto trunc;
1811 else if (advance == -3)
1812 break; /* bytes left, but not enough */
1813 else
1814 ND_PRINT("\n\t %s", buf);
1815 break;
1816 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1817 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1818 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1819 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1820 if (advance == -1)
1821 ND_PRINT("\n\t (illegal prefix length)");
1822 else
1823 ND_PRINT("\n\t %s", buf);
1824 break;
1825 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1826 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1827 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1828 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1829 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1830 if (advance == -1)
1831 ND_PRINT("\n\t (illegal length)");
1832 else if (advance == -2)
1833 goto trunc;
1834 else
1835 ND_PRINT("\n\t %s", buf);
1836 break;
1837 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1838 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1839 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1840 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1841 if (advance == -1)
1842 ND_PRINT("\n\t (illegal prefix length)");
1843 else
1844 ND_PRINT("\n\t %s", buf);
1845 break;
1846 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1847 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1848 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1849 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1850 if (advance == -1)
1851 ND_PRINT("\n\t (illegal prefix length)");
1852 else
1853 ND_PRINT("\n\t %s", buf);
1854 break;
1855 default:
1856 /*
1857 * This should not happen, we should have been protected
1858 * by bgp_mp_af_print()'s return value.
1859 */
1860 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1861 advance = -4;
1862 break;
1863 }
1864 return advance;
1865 trunc: /* we rely on the caller to recognize -2 return value */
1866 return -2;
1867 }
1868
1869 static int
1870 bgp_attr_print(netdissect_options *ndo,
1871 uint8_t atype, const u_char *pptr, u_int len,
1872 const unsigned attr_set_level)
1873 {
1874 /* allocate space for the largest possible string */
1875 char astostr[AS_STR_SIZE];
1876 u_int i;
1877 uint16_t af;
1878 uint8_t safi, snpa, nhlen;
1879 int advance;
1880 u_int tlen;
1881 const u_char *tptr;
1882 char buf[MAXHOSTNAMELEN + 100];
1883 u_int as_size;
1884 int add_path4, add_path6;
1885 int ret;
1886
1887 tptr = pptr;
1888 tlen = len;
1889
1890 switch (atype) {
1891 case BGPTYPE_ORIGIN:
1892 if (len != 1)
1893 ND_PRINT("invalid len");
1894 else {
1895 ND_PRINT("%s", tok2str(bgp_origin_values,
1896 "Unknown Origin Typecode",
1897 GET_U_1(tptr)));
1898 }
1899 break;
1900
1901 /*
1902 * Process AS4 byte path and AS2 byte path attributes here.
1903 */
1904 case BGPTYPE_AS4_PATH:
1905 case BGPTYPE_AS_PATH:
1906 if (len % 2) {
1907 ND_PRINT("invalid len");
1908 break;
1909 }
1910 if (!len) {
1911 ND_PRINT("empty");
1912 break;
1913 }
1914
1915 /*
1916 * BGP updates exchanged between New speakers that support 4
1917 * byte AS, ASs are always encoded in 4 bytes. There is no
1918 * definitive way to find this, just by the packet's
1919 * contents. So, check for packet's TLV's sanity assuming
1920 * 2 bytes first, and it does not pass, assume that ASs are
1921 * encoded in 4 bytes format and move on.
1922 */
1923 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1924
1925 while (tptr < pptr + len) {
1926 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1927 "?", GET_U_1(tptr)));
1928 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1929 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1930 ND_PRINT("%s ",
1931 as_printf(ndo, astostr, sizeof(astostr),
1932 as_size == 2 ?
1933 GET_BE_U_2(tptr + i + 2) :
1934 GET_BE_U_4(tptr + i + 2)));
1935 }
1936 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1937 "?", GET_U_1(tptr)));
1938 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1939 }
1940 break;
1941 case BGPTYPE_NEXT_HOP:
1942 if (len != 4)
1943 ND_PRINT("invalid len");
1944 else {
1945 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
1946 }
1947 break;
1948 case BGPTYPE_MULTI_EXIT_DISC:
1949 case BGPTYPE_LOCAL_PREF:
1950 if (len != 4)
1951 ND_PRINT("invalid len");
1952 else {
1953 ND_PRINT("%u", GET_BE_U_4(tptr));
1954 }
1955 break;
1956 case BGPTYPE_ATOMIC_AGGREGATE:
1957 if (len != 0)
1958 ND_PRINT("invalid len");
1959 break;
1960 case BGPTYPE_AGGREGATOR:
1961
1962 /*
1963 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
1964 * the length of this PA can be either 6 bytes or 8 bytes.
1965 */
1966 if (len != 6 && len != 8) {
1967 ND_PRINT("invalid len");
1968 break;
1969 }
1970 ND_TCHECK_LEN(tptr, len);
1971 if (len == 6) {
1972 ND_PRINT(" AS #%s, origin %s",
1973 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
1974 GET_IPADDR_STRING(tptr + 2));
1975 } else {
1976 ND_PRINT(" AS #%s, origin %s",
1977 as_printf(ndo, astostr, sizeof(astostr),
1978 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
1979 }
1980 break;
1981 case BGPTYPE_AGGREGATOR4:
1982 if (len != 8) {
1983 ND_PRINT("invalid len");
1984 break;
1985 }
1986 ND_PRINT(" AS #%s, origin %s",
1987 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
1988 GET_IPADDR_STRING(tptr + 4));
1989 break;
1990 case BGPTYPE_COMMUNITIES:
1991 if (len % 4) {
1992 ND_PRINT("invalid len");
1993 break;
1994 }
1995 while (tlen != 0) {
1996 uint32_t comm;
1997 ND_TCHECK_4(tptr);
1998 if (tlen < 4)
1999 goto trunc;
2000 comm = GET_BE_U_4(tptr);
2001 switch (comm) {
2002 case BGP_COMMUNITY_NO_EXPORT:
2003 ND_PRINT(" NO_EXPORT");
2004 break;
2005 case BGP_COMMUNITY_NO_ADVERT:
2006 ND_PRINT(" NO_ADVERTISE");
2007 break;
2008 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2009 ND_PRINT(" NO_EXPORT_SUBCONFED");
2010 break;
2011 default:
2012 ND_PRINT("%u:%u%s",
2013 (comm >> 16) & 0xffff,
2014 comm & 0xffff,
2015 (tlen>4) ? ", " : "");
2016 break;
2017 }
2018 tlen -=4;
2019 tptr +=4;
2020 }
2021 break;
2022 case BGPTYPE_ORIGINATOR_ID:
2023 if (len != 4) {
2024 ND_PRINT("invalid len");
2025 break;
2026 }
2027 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2028 break;
2029 case BGPTYPE_CLUSTER_LIST:
2030 if (len % 4) {
2031 ND_PRINT("invalid len");
2032 break;
2033 }
2034 while (tlen != 0) {
2035 if (tlen < 4)
2036 goto trunc;
2037 ND_PRINT("%s%s",
2038 GET_IPADDR_STRING(tptr),
2039 (tlen>4) ? ", " : "");
2040 tlen -=4;
2041 tptr +=4;
2042 }
2043 break;
2044 case BGPTYPE_MP_REACH_NLRI:
2045 ND_TCHECK_3(tptr);
2046 if (tlen < 3)
2047 goto trunc;
2048 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2049 if (ret == -2)
2050 goto trunc;
2051 if (ret < 0)
2052 break;
2053
2054 tptr += 3;
2055 tlen -= 3;
2056
2057 ND_TCHECK_1(tptr);
2058 if (tlen < 1)
2059 goto trunc;
2060 nhlen = GET_U_1(tptr);
2061 tptr++;
2062 tlen--;
2063
2064 if (nhlen) {
2065 u_int nnh = 0;
2066 uint8_t tnhlen = nhlen;
2067 if (tlen < tnhlen)
2068 goto trunc;
2069 ND_PRINT("\n\t nexthop: ");
2070 while (tnhlen != 0) {
2071 if (nnh++ > 0) {
2072 ND_PRINT(", " );
2073 }
2074 switch(af<<8 | safi) {
2075 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2076 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2077 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2078 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2079 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2080 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2081 case (AFNUM_INET<<8 | SAFNUM_MDT):
2082 if (tnhlen < sizeof(nd_ipv4)) {
2083 ND_PRINT("invalid len");
2084 tptr += tnhlen;
2085 tlen -= tnhlen;
2086 tnhlen = 0;
2087 } else {
2088 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2089 tptr += sizeof(nd_ipv4);
2090 tnhlen -= sizeof(nd_ipv4);
2091 tlen -= sizeof(nd_ipv4);
2092 }
2093 break;
2094 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2095 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2096 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2097 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2098 ND_PRINT("invalid len");
2099 tptr += tnhlen;
2100 tlen -= tnhlen;
2101 tnhlen = 0;
2102 } else {
2103 ND_PRINT("RD: %s, %s",
2104 bgp_vpn_rd_print(ndo, tptr),
2105 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2106 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2107 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2108 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2109 }
2110 break;
2111 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2112 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2113 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2114 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2115 if (tnhlen < sizeof(nd_ipv6)) {
2116 ND_PRINT("invalid len");
2117 tptr += tnhlen;
2118 tlen -= tnhlen;
2119 tnhlen = 0;
2120 } else {
2121 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2122 tptr += sizeof(nd_ipv6);
2123 tlen -= sizeof(nd_ipv6);
2124 tnhlen -= sizeof(nd_ipv6);
2125 }
2126 break;
2127 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2128 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2129 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2130 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2131 ND_PRINT("invalid len");
2132 tptr += tnhlen;
2133 tlen -= tnhlen;
2134 tnhlen = 0;
2135 } else {
2136 ND_PRINT("RD: %s, %s",
2137 bgp_vpn_rd_print(ndo, tptr),
2138 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2139 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2140 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2141 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2142 }
2143 break;
2144 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2145 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2146 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2147 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2148 if (tnhlen < sizeof(nd_ipv4)) {
2149 ND_PRINT("invalid len");
2150 tptr += tnhlen;
2151 tlen -= tnhlen;
2152 tnhlen = 0;
2153 } else {
2154 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2155 tptr += (sizeof(nd_ipv4));
2156 tlen -= (sizeof(nd_ipv4));
2157 tnhlen -= (sizeof(nd_ipv4));
2158 }
2159 break;
2160 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2161 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2162 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2163 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2164 tptr += tnhlen;
2165 tlen -= tnhlen;
2166 tnhlen = 0;
2167 break;
2168
2169 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2170 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2171 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2172 if (tnhlen < BGP_VPN_RD_LEN+1) {
2173 ND_PRINT("invalid len");
2174 tptr += tnhlen;
2175 tlen -= tnhlen;
2176 tnhlen = 0;
2177 } else {
2178 ND_TCHECK_LEN(tptr, tnhlen);
2179 ND_PRINT("RD: %s, %s",
2180 bgp_vpn_rd_print(ndo, tptr),
2181 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2182 /* rfc986 mapped IPv4 address ? */
2183 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2184 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2185 /* rfc1888 mapped IPv6 address ? */
2186 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2187 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2188 tptr += tnhlen;
2189 tlen -= tnhlen;
2190 tnhlen = 0;
2191 }
2192 break;
2193 default:
2194 /*
2195 * bgp_mp_af_print() should have saved us from
2196 * an unsupported AFI/SAFI.
2197 */
2198 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2199 tptr += tnhlen;
2200 tlen -= tnhlen;
2201 tnhlen = 0;
2202 goto done;
2203 break;
2204 }
2205 }
2206 }
2207 ND_PRINT(", nh-length: %u", nhlen);
2208
2209 /* As per RFC 2858; this is reserved in RFC 4760 */
2210 if (tlen < 1)
2211 goto trunc;
2212 snpa = GET_U_1(tptr);
2213 tptr++;
2214 tlen--;
2215
2216 if (snpa) {
2217 ND_PRINT("\n\t %u SNPA", snpa);
2218 for (/*nothing*/; snpa != 0; snpa--) {
2219 uint8_t snpalen;
2220 if (tlen < 1)
2221 goto trunc;
2222 snpalen = GET_U_1(tptr);
2223 ND_PRINT("\n\t %u bytes", snpalen);
2224 tptr++;
2225 tlen--;
2226 if (tlen < snpalen)
2227 goto trunc;
2228 ND_TCHECK_LEN(tptr, snpalen);
2229 tptr += snpalen;
2230 tlen -= snpalen;
2231 }
2232 } else {
2233 ND_PRINT(", no SNPA");
2234 }
2235
2236 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2237 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2238
2239 while (tptr < pptr + len) {
2240 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2241 add_path4, add_path6);
2242 if (advance == -2)
2243 goto trunc;
2244 if (advance < 0)
2245 break;
2246 tptr += advance;
2247 }
2248 break;
2249
2250 case BGPTYPE_MP_UNREACH_NLRI:
2251 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2252 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2253 if (ret == -2)
2254 goto trunc;
2255 if (ret < 0)
2256 break;
2257
2258 if (len == BGP_MP_NLRI_MINSIZE)
2259 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2260
2261 tptr += 3;
2262
2263 add_path4 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 32);
2264 add_path6 = check_add_path(ndo, tptr, (len-ND_BYTES_BETWEEN(tptr, pptr)), 128);
2265
2266 while (tptr < pptr + len) {
2267 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2268 add_path4, add_path6);
2269 if (advance == -2)
2270 goto trunc;
2271 if (advance < 0)
2272 break;
2273 tptr += advance;
2274 }
2275 break;
2276 case BGPTYPE_EXTD_COMMUNITIES:
2277 if (len % 8) {
2278 ND_PRINT("invalid len");
2279 break;
2280 }
2281 while (tlen != 0) {
2282 uint16_t extd_comm;
2283
2284 ND_TCHECK_2(tptr);
2285 if (tlen < 2)
2286 goto trunc;
2287 extd_comm=GET_BE_U_2(tptr);
2288
2289 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2290 tok2str(bgp_extd_comm_subtype_values,
2291 "unknown extd community typecode",
2292 extd_comm),
2293 extd_comm,
2294 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2295
2296 ND_TCHECK_8(tptr);
2297 if (tlen < 8)
2298 goto trunc;
2299 ND_PRINT(": ");
2300 bgp_extended_community_print(ndo, tptr);
2301 tlen -= 8;
2302 tptr += 8;
2303 }
2304 break;
2305
2306 case BGPTYPE_PMSI_TUNNEL:
2307 {
2308 uint8_t tunnel_type, flags;
2309
2310 ND_TCHECK_5(tptr);
2311 if (tlen < 5)
2312 goto trunc;
2313 flags = GET_U_1(tptr);
2314 tunnel_type = GET_U_1(tptr + 1);
2315
2316 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2317 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2318 tunnel_type,
2319 bittok2str(bgp_pmsi_flag_values, "none", flags),
2320 GET_BE_U_3(tptr + 2)>>4);
2321
2322 tptr +=5;
2323 tlen -= 5;
2324
2325 switch (tunnel_type) {
2326 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2327 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2328 ND_PRINT("\n\t Sender %s, P-Group %s",
2329 GET_IPADDR_STRING(tptr),
2330 GET_IPADDR_STRING(tptr+4));
2331 break;
2332
2333 case BGP_PMSI_TUNNEL_PIM_SSM:
2334 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2335 GET_IPADDR_STRING(tptr),
2336 GET_IPADDR_STRING(tptr+4));
2337 break;
2338 case BGP_PMSI_TUNNEL_INGRESS:
2339 ND_PRINT("\n\t Tunnel-Endpoint %s",
2340 GET_IPADDR_STRING(tptr));
2341 break;
2342 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2343 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2344 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2345 GET_IPADDR_STRING(tptr),
2346 GET_BE_U_4(tptr + 4));
2347 break;
2348 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2349 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2350 GET_IPADDR_STRING(tptr),
2351 GET_BE_U_4(tptr + 4));
2352 break;
2353 default:
2354 if (ndo->ndo_vflag <= 1) {
2355 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2356 }
2357 }
2358 break;
2359 }
2360 case BGPTYPE_AIGP:
2361 {
2362 uint8_t type;
2363 uint16_t length;
2364
2365 while (tlen >= 3) {
2366 type = GET_U_1(tptr);
2367 length = GET_BE_U_2(tptr + 1);
2368 tptr += 3;
2369 tlen -= 3;
2370
2371 ND_PRINT("\n\t %s TLV (%u), length %u",
2372 tok2str(bgp_aigp_values, "Unknown", type),
2373 type, length);
2374
2375 if (length < 3)
2376 goto trunc;
2377 length -= 3;
2378
2379 /*
2380 * Check if we can read the TLV data.
2381 */
2382 ND_TCHECK_LEN(tptr + 3, length);
2383 if (tlen < length)
2384 goto trunc;
2385
2386 switch (type) {
2387
2388 case BGP_AIGP_TLV:
2389 if (length < 8)
2390 goto trunc;
2391 ND_PRINT(", metric %" PRIu64,
2392 GET_BE_U_8(tptr));
2393 break;
2394
2395 default:
2396 if (ndo->ndo_vflag <= 1) {
2397 print_unknown_data(ndo, tptr,"\n\t ", length);
2398 }
2399 }
2400
2401 tptr += length;
2402 tlen -= length;
2403 }
2404 break;
2405 }
2406 case BGPTYPE_ATTR_SET:
2407 ND_TCHECK_4(tptr);
2408 if (len < 4)
2409 goto trunc;
2410 ND_PRINT("\n\t Origin AS: %s",
2411 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2412 tptr += 4;
2413 len -= 4;
2414
2415 while (len) {
2416 u_int aflags, alenlen, alen;
2417
2418 ND_TCHECK_2(tptr);
2419 if (len < 2) {
2420 ND_PRINT(" [path attr too short]");
2421 tptr += len;
2422 break;
2423 }
2424 aflags = GET_U_1(tptr);
2425 atype = GET_U_1(tptr + 1);
2426 tptr += 2;
2427 len -= 2;
2428 alenlen = bgp_attr_lenlen(aflags, tptr);
2429 ND_TCHECK_LEN(tptr, alenlen);
2430 if (len < alenlen) {
2431 ND_PRINT(" [path attr too short]");
2432 tptr += len;
2433 break;
2434 }
2435 alen = bgp_attr_len(aflags, tptr);
2436 tptr += alenlen;
2437 len -= alenlen;
2438
2439 ND_PRINT("\n\t %s (%u), length: %u",
2440 tok2str(bgp_attr_values,
2441 "Unknown Attribute", atype),
2442 atype,
2443 alen);
2444
2445 if (aflags) {
2446 ND_PRINT(", Flags [%s%s%s%s",
2447 aflags & 0x80 ? "O" : "",
2448 aflags & 0x40 ? "T" : "",
2449 aflags & 0x20 ? "P" : "",
2450 aflags & 0x10 ? "E" : "");
2451 if (aflags & 0xf)
2452 ND_PRINT("+%x", aflags & 0xf);
2453 ND_PRINT("]");
2454 }
2455 ND_PRINT(": ");
2456 if (len < alen) {
2457 ND_PRINT(" [path attr too short]");
2458 tptr += len;
2459 break;
2460 }
2461 /*
2462 * The protocol encoding per se allows ATTR_SET to be nested
2463 * as many times as the message can accommodate. This printer
2464 * used to be able to recurse into ATTR_SET contents until the
2465 * stack exhaustion, but now there is a limit on that (if live
2466 * protocol exchange goes that many levels deep, something is
2467 * probably wrong anyway). Feel free to refine this value if
2468 * you can find the spec with respective normative text.
2469 */
2470 if (attr_set_level == 10)
2471 ND_PRINT("(too many nested levels, not recursing)");
2472 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2473 return 0;
2474 tptr += alen;
2475 len -= alen;
2476 }
2477 break;
2478
2479 case BGPTYPE_LARGE_COMMUNITY:
2480 if (len == 0 || len % 12) {
2481 ND_PRINT("invalid len");
2482 break;
2483 }
2484 ND_PRINT("\n\t ");
2485 while (len != 0) {
2486 ND_PRINT("%u:%u:%u%s",
2487 GET_BE_U_4(tptr),
2488 GET_BE_U_4(tptr + 4),
2489 GET_BE_U_4(tptr + 8),
2490 (len > 12) ? ", " : "");
2491 tptr += 12;
2492 /*
2493 * len will always be a multiple of 12, as per the above,
2494 * so this will never underflow.
2495 */
2496 len -= 12;
2497 }
2498 break;
2499 default:
2500 ND_TCHECK_LEN(pptr, len);
2501 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2502 if (ndo->ndo_vflag <= 1)
2503 print_unknown_data(ndo, pptr, "\n\t ", len);
2504 break;
2505 }
2506 done:
2507 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2508 ND_TCHECK_LEN(pptr, len);
2509 print_unknown_data(ndo, pptr, "\n\t ", len);
2510 }
2511 return 1;
2512
2513 trunc:
2514 return 0;
2515 }
2516
2517 static void
2518 bgp_capabilities_print(netdissect_options *ndo,
2519 const u_char *opt, u_int caps_len)
2520 {
2521 /* allocate space for the largest possible string */
2522 char astostr[AS_STR_SIZE];
2523 u_int cap_type, cap_len, tcap_len, cap_offset;
2524 u_int i = 0;
2525
2526 while (i < caps_len) {
2527 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2528 cap_type=GET_U_1(opt + i);
2529 cap_len=GET_U_1(opt + i + 1);
2530 ND_PRINT("\n\t %s (%u), length: %u",
2531 tok2str(bgp_capcode_values, "Unknown", cap_type),
2532 cap_type,
2533 cap_len);
2534 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2535 switch (cap_type) {
2536 case BGP_CAPCODE_MP:
2537 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2538 if (cap_len < 4) {
2539 ND_PRINT(" (too short, < 4)");
2540 return;
2541 }
2542 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2543 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2544 GET_BE_U_2(opt + i + 2),
2545 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2546 GET_U_1(opt + i + 5));
2547 break;
2548 case BGP_CAPCODE_ML:
2549 cap_offset = 2;
2550 tcap_len = cap_len;
2551 while (tcap_len >= 4) {
2552 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2553 tok2str(af_values, "Unknown",
2554 GET_BE_U_2(opt + i + cap_offset)),
2555 GET_BE_U_2(opt + i + cap_offset),
2556 tok2str(bgp_safi_values, "Unknown",
2557 GET_U_1(opt + i + cap_offset + 2)),
2558 GET_U_1(opt + i + cap_offset + 2),
2559 GET_U_1(opt + i + cap_offset + 3));
2560 tcap_len -= 4;
2561 cap_offset += 4;
2562 }
2563 break;
2564 case BGP_CAPCODE_RESTART:
2565 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2566 if (cap_len < 2) {
2567 ND_PRINT(" (too short, < 2)");
2568 return;
2569 }
2570 tcap_len=cap_len;
2571 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2572 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2573 GET_BE_U_2(opt + i + 2)&0xfff);
2574 tcap_len-=2;
2575 cap_offset=4;
2576 while(tcap_len>=4) {
2577 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2578 tok2str(af_values,"Unknown",
2579 GET_BE_U_2(opt + i + cap_offset)),
2580 GET_BE_U_2(opt + i + cap_offset),
2581 tok2str(bgp_safi_values,"Unknown",
2582 GET_U_1(opt + i + cap_offset + 2)),
2583 GET_U_1(opt + (i + cap_offset + 2)),
2584 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2585 tcap_len -= 4;
2586 cap_offset += 4;
2587 }
2588 break;
2589 case BGP_CAPCODE_RR:
2590 case BGP_CAPCODE_LLGR:
2591 case BGP_CAPCODE_RR_CISCO:
2592 break;
2593 case BGP_CAPCODE_AS_NEW:
2594 /*
2595 * Extract the 4 byte AS number encoded.
2596 */
2597 if (cap_len < 4) {
2598 ND_PRINT(" (too short, < 4)");
2599 return;
2600 }
2601 ND_PRINT("\n\t\t 4 Byte AS %s",
2602 as_printf(ndo, astostr, sizeof(astostr),
2603 GET_BE_U_4(opt + i + 2)));
2604 break;
2605 case BGP_CAPCODE_ADD_PATH:
2606 if (cap_len == 0) {
2607 ND_PRINT(" (bogus)"); /* length */
2608 break;
2609 }
2610 tcap_len=cap_len;
2611 cap_offset=2;
2612 while (tcap_len != 0) {
2613 if (tcap_len < 4) {
2614 nd_print_invalid(ndo);
2615 break;
2616 }
2617 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2618 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2619 GET_BE_U_2(opt + i + cap_offset),
2620 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2621 GET_U_1(opt + (i + cap_offset + 2)),
2622 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2623 );
2624 tcap_len -= 4;
2625 cap_offset += 4;
2626 }
2627 break;
2628 default:
2629 ND_PRINT("\n\t\tno decoder for Capability %u",
2630 cap_type);
2631 if (ndo->ndo_vflag <= 1)
2632 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2633 cap_len);
2634 break;
2635 }
2636 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2637 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2638 }
2639 i += BGP_CAP_HEADER_SIZE + cap_len;
2640 }
2641 return;
2642
2643 trunc:
2644 nd_print_trunc(ndo);
2645 }
2646
2647 static void
2648 bgp_open_print(netdissect_options *ndo,
2649 const u_char *dat, u_int length)
2650 {
2651 /* allocate space for the largest possible string */
2652 char astostr[AS_STR_SIZE];
2653 const struct bgp_open *bgp_open_header;
2654 u_int optslen;
2655 const struct bgp_opt *bgpopt;
2656 const u_char *opt;
2657 u_int i;
2658
2659 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2660 if (length < BGP_OPEN_SIZE)
2661 goto trunc;
2662
2663 bgp_open_header = (const struct bgp_open *)dat;
2664
2665 ND_PRINT("\n\t Version %u, ",
2666 GET_U_1(bgp_open_header->bgpo_version));
2667 ND_PRINT("my AS %s, ",
2668 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2669 ND_PRINT("Holdtime %us, ",
2670 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2671 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2672 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2673 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2674
2675 opt = dat + BGP_OPEN_SIZE;
2676 length -= BGP_OPEN_SIZE;
2677
2678 i = 0;
2679 while (i < optslen) {
2680 uint8_t opt_type, opt_len;
2681
2682 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2683 if (length < BGP_OPT_SIZE + i)
2684 goto trunc;
2685 bgpopt = (const struct bgp_opt *)(opt + i);
2686 opt_type = GET_U_1(bgpopt->bgpopt_type);
2687 opt_len = GET_U_1(bgpopt->bgpopt_len);
2688 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2689 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2690 opt_type, opt_len);
2691 break;
2692 }
2693
2694 ND_PRINT("\n\t Option %s (%u), length: %u",
2695 tok2str(bgp_opt_values,"Unknown",opt_type),
2696 opt_type,
2697 opt_len);
2698
2699 /* now let's decode the options we know*/
2700 switch(opt_type) {
2701
2702 case BGP_OPT_CAP:
2703 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2704 opt_len);
2705 break;
2706
2707 case BGP_OPT_AUTH:
2708 default:
2709 ND_PRINT("\n\t no decoder for option %u",
2710 opt_type);
2711 break;
2712 }
2713 i += BGP_OPT_SIZE + opt_len;
2714 }
2715 return;
2716 trunc:
2717 nd_print_trunc(ndo);
2718 }
2719
2720 static void
2721 bgp_update_print(netdissect_options *ndo,
2722 const u_char *dat, u_int length)
2723 {
2724 const u_char *p;
2725 u_int withdrawn_routes_len;
2726 char buf[MAXHOSTNAMELEN + 100];
2727 int wpfx;
2728 u_int len;
2729 int i;
2730 int add_path;
2731 u_int path_id = 0;
2732
2733 ND_TCHECK_LEN(dat, BGP_SIZE);
2734 if (length < BGP_SIZE)
2735 goto trunc;
2736 p = dat + BGP_SIZE;
2737 length -= BGP_SIZE;
2738
2739 /* Unfeasible routes */
2740 ND_TCHECK_2(p);
2741 if (length < 2)
2742 goto trunc;
2743 withdrawn_routes_len = GET_BE_U_2(p);
2744 p += 2;
2745 length -= 2;
2746 if (withdrawn_routes_len > 1) {
2747 /*
2748 * Without keeping state from the original NLRI message,
2749 * it's not possible to tell if this a v4 or v6 route,
2750 * so only try to decode it if we're not v6 enabled.
2751 */
2752 ND_TCHECK_LEN(p, withdrawn_routes_len);
2753 if (length < withdrawn_routes_len)
2754 goto trunc;
2755 ND_PRINT("\n\t Withdrawn routes:");
2756 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2757 while (withdrawn_routes_len != 0) {
2758 if (add_path) {
2759 if (withdrawn_routes_len < 4) {
2760 p += withdrawn_routes_len;
2761 length -= withdrawn_routes_len;
2762 break;
2763 }
2764 path_id = GET_BE_U_4(p);
2765 p += 4;
2766 length -= 4;
2767 withdrawn_routes_len -= 4;
2768 }
2769 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2770 if (wpfx == -1) {
2771 ND_PRINT("\n\t (illegal prefix length)");
2772 break;
2773 } else if (wpfx == -2)
2774 goto trunc; /* bytes left, but not enough */
2775 else {
2776 ND_PRINT("\n\t %s", buf);
2777 if (add_path) {
2778 ND_PRINT(" Path Id: %u", path_id);
2779 }
2780 p += wpfx;
2781 length -= wpfx;
2782 withdrawn_routes_len -= wpfx;
2783 }
2784 }
2785 } else {
2786 ND_TCHECK_LEN(p, withdrawn_routes_len);
2787 if (length < withdrawn_routes_len)
2788 goto trunc;
2789 p += withdrawn_routes_len;
2790 length -= withdrawn_routes_len;
2791 }
2792
2793 ND_TCHECK_2(p);
2794 if (length < 2)
2795 goto trunc;
2796 len = GET_BE_U_2(p);
2797 p += 2;
2798 length -= 2;
2799
2800 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2801 /* No withdrawn routes, no path attributes, no NLRI */
2802 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2803 return;
2804 }
2805
2806 if (len) {
2807 /* do something more useful!*/
2808 while (len) {
2809 uint8_t aflags, atype, alenlen;
2810 uint16_t alen;
2811
2812 ND_TCHECK_2(p);
2813 if (length < 2)
2814 goto trunc;
2815 if (len < 2) {
2816 ND_PRINT("\n\t [path attrs too short]");
2817 p += len;
2818 length -= len;
2819 break;
2820 }
2821 aflags = GET_U_1(p);
2822 atype = GET_U_1(p + 1);
2823 p += 2;
2824 len -= 2;
2825 length -= 2;
2826 alenlen = bgp_attr_lenlen(aflags, p);
2827 ND_TCHECK_LEN(p, alenlen);
2828 if (length < alenlen)
2829 goto trunc;
2830 if (len < alenlen) {
2831 ND_PRINT("\n\t [path attrs too short]");
2832 p += len;
2833 length -= len;
2834 break;
2835 }
2836 alen = bgp_attr_len(aflags, p);
2837 p += alenlen;
2838 len -= alenlen;
2839 length -= alenlen;
2840
2841 ND_PRINT("\n\t %s (%u), length: %u",
2842 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2843 atype,
2844 alen);
2845
2846 if (aflags) {
2847 ND_PRINT(", Flags [%s%s%s%s",
2848 aflags & 0x80 ? "O" : "",
2849 aflags & 0x40 ? "T" : "",
2850 aflags & 0x20 ? "P" : "",
2851 aflags & 0x10 ? "E" : "");
2852 if (aflags & 0xf)
2853 ND_PRINT("+%x", aflags & 0xf);
2854 ND_PRINT("]: ");
2855 }
2856 if (len < alen) {
2857 ND_PRINT(" [path attrs too short]");
2858 p += len;
2859 length -= len;
2860 break;
2861 }
2862 if (length < alen)
2863 goto trunc;
2864 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2865 goto trunc;
2866 p += alen;
2867 len -= alen;
2868 length -= alen;
2869 }
2870 }
2871
2872 if (length) {
2873 add_path = check_add_path(ndo, p, length, 32);
2874 ND_PRINT("\n\t Updated routes:");
2875 while (length != 0) {
2876 if (add_path) {
2877 ND_TCHECK_4(p);
2878 if (length < 4)
2879 goto trunc;
2880 path_id = GET_BE_U_4(p);
2881 p += 4;
2882 length -= 4;
2883 }
2884 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2885 if (i == -1) {
2886 ND_PRINT("\n\t (illegal prefix length)");
2887 break;
2888 } else if (i == -2)
2889 goto trunc; /* bytes left, but not enough */
2890 else {
2891 ND_PRINT("\n\t %s", buf);
2892 if (add_path) {
2893 ND_PRINT(" Path Id: %u", path_id);
2894 }
2895 p += i;
2896 length -= i;
2897 }
2898 }
2899 }
2900 return;
2901 trunc:
2902 nd_print_trunc(ndo);
2903 }
2904
2905 static void
2906 bgp_notification_print(netdissect_options *ndo,
2907 const u_char *dat, u_int length)
2908 {
2909 const struct bgp_notification *bgp_notification_header;
2910 const u_char *tptr;
2911 uint8_t bgpn_major, bgpn_minor;
2912 uint8_t shutdown_comm_length;
2913 uint8_t remainder_offset;
2914
2915 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2916 if (length<BGP_NOTIFICATION_SIZE)
2917 return;
2918
2919 bgp_notification_header = (const struct bgp_notification *)dat;
2920 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
2921 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
2922
2923 ND_PRINT(", %s (%u)",
2924 tok2str(bgp_notify_major_values, "Unknown Error",
2925 bgpn_major),
2926 bgpn_major);
2927
2928 switch (bgpn_major) {
2929
2930 case BGP_NOTIFY_MAJOR_MSG:
2931 ND_PRINT(", subcode %s (%u)",
2932 tok2str(bgp_notify_minor_msg_values, "Unknown",
2933 bgpn_minor),
2934 bgpn_minor);
2935 break;
2936 case BGP_NOTIFY_MAJOR_OPEN:
2937 ND_PRINT(", subcode %s (%u)",
2938 tok2str(bgp_notify_minor_open_values, "Unknown",
2939 bgpn_minor),
2940 bgpn_minor);
2941 break;
2942 case BGP_NOTIFY_MAJOR_UPDATE:
2943 ND_PRINT(", subcode %s (%u)",
2944 tok2str(bgp_notify_minor_update_values, "Unknown",
2945 bgpn_minor),
2946 bgpn_minor);
2947 break;
2948 case BGP_NOTIFY_MAJOR_FSM:
2949 ND_PRINT(" subcode %s (%u)",
2950 tok2str(bgp_notify_minor_fsm_values, "Unknown",
2951 bgpn_minor),
2952 bgpn_minor);
2953 break;
2954 case BGP_NOTIFY_MAJOR_CAP:
2955 ND_PRINT(" subcode %s (%u)",
2956 tok2str(bgp_notify_minor_cap_values, "Unknown",
2957 bgpn_minor),
2958 bgpn_minor);
2959 break;
2960 case BGP_NOTIFY_MAJOR_CEASE:
2961 ND_PRINT(", subcode %s (%u)",
2962 tok2str(bgp_notify_minor_cease_values, "Unknown",
2963 bgpn_minor),
2964 bgpn_minor);
2965
2966 /* draft-ietf-idr-cease-subcode-02 mentions optionally 7 bytes
2967 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
2968 */
2969 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
2970 tptr = dat + BGP_NOTIFICATION_SIZE;
2971 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
2972 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
2973 GET_BE_U_2(tptr),
2974 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
2975 GET_U_1((tptr + 2)),
2976 GET_BE_U_4(tptr + 3));
2977 }
2978 /*
2979 * draft-ietf-idr-shutdown describes a method to send a communication
2980 * intended for human consumption regarding the Administrative Shutdown
2981 */
2982 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
2983 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
2984 length >= BGP_NOTIFICATION_SIZE + 1) {
2985 tptr = dat + BGP_NOTIFICATION_SIZE;
2986 shutdown_comm_length = GET_U_1(tptr);
2987 remainder_offset = 0;
2988 /* garbage, hexdump it all */
2989 if (shutdown_comm_length > BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN ||
2990 shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
2991 ND_PRINT(", invalid Shutdown Communication length");
2992 }
2993 else if (shutdown_comm_length == 0) {
2994 ND_PRINT(", empty Shutdown Communication");
2995 remainder_offset += 1;
2996 }
2997 /* a proper shutdown communication */
2998 else {
2999 ND_TCHECK_LEN(tptr + 1, shutdown_comm_length);
3000 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3001 nd_printjn(ndo, tptr+1, shutdown_comm_length);
3002 ND_PRINT("\"");
3003 remainder_offset += shutdown_comm_length + 1;
3004 }
3005 /* if there is trailing data, hexdump it */
3006 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3007 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3008 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3009 }
3010 }
3011 break;
3012 default:
3013 break;
3014 }
3015
3016 return;
3017 trunc:
3018 nd_print_trunc(ndo);
3019 }
3020
3021 static void
3022 bgp_route_refresh_print(netdissect_options *ndo,
3023 const u_char *pptr, u_int len)
3024 {
3025 const struct bgp_route_refresh *bgp_route_refresh_header;
3026
3027 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3028
3029 /* some little sanity checking */
3030 if (len<BGP_ROUTE_REFRESH_SIZE)
3031 return;
3032
3033 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3034
3035 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3036 tok2str(af_values,"Unknown",
3037 GET_BE_U_2(bgp_route_refresh_header->afi)),
3038 GET_BE_U_2(bgp_route_refresh_header->afi),
3039 tok2str(bgp_safi_values,"Unknown",
3040 GET_U_1(bgp_route_refresh_header->safi)),
3041 GET_U_1(bgp_route_refresh_header->safi));
3042
3043 if (ndo->ndo_vflag > 1) {
3044 ND_TCHECK_LEN(pptr, len);
3045 print_unknown_data(ndo, pptr, "\n\t ", len);
3046 }
3047
3048 return;
3049 trunc:
3050 nd_print_trunc(ndo);
3051 }
3052
3053 static int
3054 bgp_pdu_print(netdissect_options *ndo,
3055 const u_char *dat, u_int length)
3056 {
3057 const struct bgp *bgp_header;
3058 uint8_t bgp_type;
3059
3060 ND_TCHECK_LEN(dat, BGP_SIZE);
3061 bgp_header = (const struct bgp *)dat;
3062 bgp_type = GET_U_1(bgp_header->bgp_type);
3063
3064 ND_PRINT("\n\t%s Message (%u), length: %u",
3065 tok2str(bgp_msg_values, "Unknown", bgp_type),
3066 bgp_type,
3067 length);
3068
3069 switch (bgp_type) {
3070 case BGP_OPEN:
3071 bgp_open_print(ndo, dat, length);
3072 break;
3073 case BGP_UPDATE:
3074 bgp_update_print(ndo, dat, length);
3075 break;
3076 case BGP_NOTIFICATION:
3077 bgp_notification_print(ndo, dat, length);
3078 break;
3079 case BGP_KEEPALIVE:
3080 break;
3081 case BGP_ROUTE_REFRESH:
3082 bgp_route_refresh_print(ndo, dat, length);
3083 break;
3084 default:
3085 /* we have no decoder for the BGP message */
3086 ND_TCHECK_LEN(dat, length);
3087 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3088 print_unknown_data(ndo, dat, "\n\t ", length);
3089 break;
3090 }
3091 return 1;
3092 trunc:
3093 nd_print_trunc(ndo);
3094 return 0;
3095 }
3096
3097 void
3098 bgp_print(netdissect_options *ndo,
3099 const u_char *dat, u_int length _U_)
3100 {
3101 const u_char *p;
3102 const u_char *ep = ndo->ndo_snapend;
3103 const u_char *start;
3104 const u_char marker[] = {
3105 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3106 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3107 };
3108 const struct bgp *bgp_header;
3109 uint16_t hlen;
3110
3111 ndo->ndo_protocol = "bgp";
3112 ND_PRINT(": BGP");
3113
3114 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3115 return;
3116
3117 p = dat;
3118 start = p;
3119 while (p < ep) {
3120 if (!ND_TTEST_1(p))
3121 break;
3122 if (GET_U_1(p) != 0xff) {
3123 p++;
3124 continue;
3125 }
3126
3127 if (!ND_TTEST_LEN(p, sizeof(marker)))
3128 break;
3129 if (memcmp(p, marker, sizeof(marker)) != 0) {
3130 p++;
3131 continue;
3132 }
3133
3134 /* found BGP header */
3135 ND_TCHECK_LEN(p, BGP_SIZE);
3136 bgp_header = (const struct bgp *)p;
3137
3138 if (start != p)
3139 nd_print_trunc(ndo);
3140
3141 hlen = GET_BE_U_2(bgp_header->bgp_len);
3142 if (hlen < BGP_SIZE) {
3143 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3144 nd_print_invalid(ndo);
3145 break;
3146 }
3147
3148 if (ND_TTEST_LEN(p, hlen)) {
3149 if (!bgp_pdu_print(ndo, p, hlen))
3150 return;
3151 p += hlen;
3152 start = p;
3153 } else {
3154 ND_PRINT("\n[|BGP %s]",
3155 tok2str(bgp_msg_values,
3156 "Unknown Message Type",
3157 GET_U_1(bgp_header->bgp_type)));
3158 break;
3159 }
3160 }
3161
3162 return;
3163
3164 trunc:
3165 nd_print_trunc(ndo);
3166 }
[mirror] the TCPdump network dissector