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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 /* RFC 4486 */
267 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
268 #define BGP_NOTIFY_MINOR_CEASE_SHUT 2
269 #define BGP_NOTIFY_MINOR_CEASE_RESET 4
270 static const struct tok bgp_notify_minor_cease_values[] = {
271 { BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
272 { BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
273 { 3, "Peer Unconfigured"},
274 { BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
275 { 5, "Connection Rejected"},
276 { 6, "Other Configuration Change"},
277 { 7, "Connection Collision Resolution"},
278 { 0, NULL}
279 };
280
281 static const struct tok bgp_notify_minor_msg_values[] = {
282 { 1, "Connection Not Synchronized"},
283 { 2, "Bad Message Length"},
284 { 3, "Bad Message Type"},
285 { 0, NULL}
286 };
287
288 static const struct tok bgp_notify_minor_open_values[] = {
289 { 1, "Unsupported Version Number"},
290 { 2, "Bad Peer AS"},
291 { 3, "Bad BGP Identifier"},
292 { 4, "Unsupported Optional Parameter"},
293 { 5, "Authentication Failure"},
294 { 6, "Unacceptable Hold Time"},
295 { 7, "Capability Message Error"},
296 { 0, NULL}
297 };
298
299 static const struct tok bgp_notify_minor_update_values[] = {
300 { 1, "Malformed Attribute List"},
301 { 2, "Unrecognized Well-known Attribute"},
302 { 3, "Missing Well-known Attribute"},
303 { 4, "Attribute Flags Error"},
304 { 5, "Attribute Length Error"},
305 { 6, "Invalid ORIGIN Attribute"},
306 { 7, "AS Routing Loop"},
307 { 8, "Invalid NEXT_HOP Attribute"},
308 { 9, "Optional Attribute Error"},
309 { 10, "Invalid Network Field"},
310 { 11, "Malformed AS_PATH"},
311 { 0, NULL}
312 };
313
314 static const struct tok bgp_notify_minor_fsm_values[] = {
315 { 0, "Unspecified Error"},
316 { 1, "In OpenSent State"},
317 { 2, "In OpenConfirm State"},
318 { 3, "In Established State"},
319 { 0, NULL }
320 };
321
322 static const struct tok bgp_notify_minor_cap_values[] = {
323 { 1, "Invalid Action Value" },
324 { 2, "Invalid Capability Length" },
325 { 3, "Malformed Capability Value" },
326 { 4, "Unsupported Capability Code" },
327 { 0, NULL }
328 };
329
330 static const struct tok bgp_origin_values[] = {
331 { 0, "IGP"},
332 { 1, "EGP"},
333 { 2, "Incomplete"},
334 { 0, NULL}
335 };
336
337 #define BGP_PMSI_TUNNEL_RSVP_P2MP 1
338 #define BGP_PMSI_TUNNEL_LDP_P2MP 2
339 #define BGP_PMSI_TUNNEL_PIM_SSM 3
340 #define BGP_PMSI_TUNNEL_PIM_SM 4
341 #define BGP_PMSI_TUNNEL_PIM_BIDIR 5
342 #define BGP_PMSI_TUNNEL_INGRESS 6
343 #define BGP_PMSI_TUNNEL_LDP_MP2MP 7
344
345 static const struct tok bgp_pmsi_tunnel_values[] = {
346 { BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
347 { BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
348 { BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
349 { BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
350 { BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
351 { BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
352 { BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
353 { 0, NULL}
354 };
355
356 static const struct tok bgp_pmsi_flag_values[] = {
357 { 0x01, "Leaf Information required"},
358 { 0, NULL}
359 };
360
361 #define BGP_AIGP_TLV 1
362
363 static const struct tok bgp_aigp_values[] = {
364 { BGP_AIGP_TLV, "AIGP"},
365 { 0, NULL}
366 };
367
368 /* Subsequent address family identifier, RFC2283 section 7 */
369 #define SAFNUM_RES 0
370 #define SAFNUM_UNICAST 1
371 #define SAFNUM_MULTICAST 2
372 #define SAFNUM_UNIMULTICAST 3 /* deprecated now */
373 /* labeled BGP RFC3107 */
374 #define SAFNUM_LABUNICAST 4
375 /* RFC6514 */
376 #define SAFNUM_MULTICAST_VPN 5
377 /* draft-nalawade-kapoor-tunnel-safi */
378 #define SAFNUM_TUNNEL 64
379 /* RFC4761 */
380 #define SAFNUM_VPLS 65
381 /* RFC6037 */
382 #define SAFNUM_MDT 66
383 /* RFC7432 */
384 #define SAFNUM_EVPN 70
385 /* RFC4364 */
386 #define SAFNUM_VPNUNICAST 128
387 /* RFC6513 */
388 #define SAFNUM_VPNMULTICAST 129
389 #define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
390 /* RFC4684 */
391 #define SAFNUM_RT_ROUTING_INFO 132
392
393 #define BGP_VPN_RD_LEN 8
394
395 static const struct tok bgp_safi_values[] = {
396 { SAFNUM_RES, "Reserved"},
397 { SAFNUM_UNICAST, "Unicast"},
398 { SAFNUM_MULTICAST, "Multicast"},
399 { SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
400 { SAFNUM_LABUNICAST, "labeled Unicast"},
401 { SAFNUM_TUNNEL, "Tunnel"},
402 { SAFNUM_VPLS, "VPLS"},
403 { SAFNUM_MDT, "MDT"},
404 { SAFNUM_EVPN, "EVPN"},
405 { SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
406 { SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
407 { SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
408 { SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
409 { SAFNUM_MULTICAST_VPN, "Multicast VPN"},
410 { 0, NULL }
411 };
412
413 /* well-known community */
414 #define BGP_COMMUNITY_NO_EXPORT 0xffffff01
415 #define BGP_COMMUNITY_NO_ADVERT 0xffffff02
416 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
417
418 /* Extended community type - RFC 4360 */
419 #define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
420 #define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
421 #define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
422 #define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
423 #define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
424 #define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
425 #define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
426 /* rfc2547 bgp-mpls-vpns */
427 #define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
428 #define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
429 #define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
430 #define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
431
432 #define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
433 #define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
434 #define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
435
436 #define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
437 #define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
438
439 #define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
440
441 #define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
442 #define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
443 #define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
444 #define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
445
446 /* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
447 #define BGP_EXT_COM_EIGRP_GEN 0x8800
448 #define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
449 #define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
450 #define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
451 #define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
452 #define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
453
454 static const struct tok bgp_extd_comm_flag_values[] = {
455 { 0x8000, "vendor-specific"},
456 { 0x4000, "non-transitive"},
457 { 0, NULL},
458 };
459
460 static const struct tok bgp_extd_comm_subtype_values[] = {
461 { BGP_EXT_COM_RT_0, "target"},
462 { BGP_EXT_COM_RT_1, "target"},
463 { BGP_EXT_COM_RT_2, "target"},
464 { BGP_EXT_COM_RO_0, "origin"},
465 { BGP_EXT_COM_RO_1, "origin"},
466 { BGP_EXT_COM_RO_2, "origin"},
467 { BGP_EXT_COM_LINKBAND, "link-BW"},
468 { BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
469 { BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
470 { BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
471 { BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
472 { BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
473 { BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
474 { BGP_EXT_COM_ENCAP, "encapsulation"},
475 { BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
476 { BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
477 { BGP_EXT_COM_L2INFO, "layer2-info"},
478 { BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
479 { BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
480 { BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
481 { BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
482 { BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
483 { BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
484 { BGP_EXT_COM_SOURCE_AS, "source-AS" },
485 { BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
486 { BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
487 { BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
488 { 0, NULL},
489 };
490
491 /* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
492 #define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
493 #define BGP_ENCAP_TUNNEL_GRE 2
494 #define BGP_ENCAP_TUNNEL_TRANSMIT 3
495 #define BGP_ENCAP_TUNNEL_IPSEC 4
496 #define BGP_ENCAP_TUNNEL_IP_IPSEC 5
497 #define BGP_ENCAP_TUNNEL_MPLS_IP 6
498 #define BGP_ENCAP_TUNNEL_IP_IP 7
499 #define BGP_ENCAP_TUNNEL_VXLAN 8
500 #define BGP_ENCAP_TUNNEL_NVGRE 9
501 #define BGP_ENCAP_TUNNEL_MPLS 10
502 #define BGP_ENCAP_TUNNEL_MPLS_GRE 11
503 #define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
504 #define BGP_ENCAP_TUNNEL_MPLS_UDP 13
505 #define BGP_ENCAP_TUNNEL_IPV6 14
506 #define BGP_ENCAP_TUNNEL_SR_TE 15
507 #define BGP_ENCAP_TUNNEL_BARE 16
508 #define BGP_ENCAP_TUNNEL_SR 17
509
510 static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
511 { BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
512 { BGP_ENCAP_TUNNEL_GRE, "GRE"},
513 { BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
514 { BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
515 { BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
516 { BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
517 { BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
518 { BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
519 { BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
520 { BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
521 { BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
522 { BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
523 { BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
524 { BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
525 { BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
526 { BGP_ENCAP_TUNNEL_BARE, "Bare"},
527 { BGP_ENCAP_TUNNEL_SR, "SR"},
528 { 0, NULL},
529 };
530
531 /* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
532 #define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
533 #define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
534 #define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
535 #define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
536 #define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
537 #define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
538 #define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
539
540 static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
541 { BGP_OSPF_RTYPE_RTR, "Router" },
542 { BGP_OSPF_RTYPE_NET, "Network" },
543 { BGP_OSPF_RTYPE_SUM, "Summary" },
544 { BGP_OSPF_RTYPE_EXT, "External" },
545 { BGP_OSPF_RTYPE_NSSA,"NSSA External" },
546 { BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
547 { 0, NULL },
548 };
549
550 /* ADD-PATH Send/Receive field values */
551 static const struct tok bgp_add_path_recvsend[] = {
552 { 1, "Receive" },
553 { 2, "Send" },
554 { 3, "Both" },
555 { 0, NULL },
556 };
557
558 #define AS_STR_SIZE sizeof("xxxxx.xxxxx")
559
560 /*
561 * as_printf
562 *
563 * Convert an AS number into a string and return string pointer.
564 *
565 * Depending on bflag is set or not, AS number is converted into ASDOT notation
566 * or plain number notation.
567 *
568 */
569 static char *
570 as_printf(netdissect_options *ndo,
571 char *str, size_t size, u_int asnum)
572 {
573 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
574 snprintf(str, size, "%u", asnum);
575 } else {
576 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
577 }
578 return str;
579 }
580
581 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
582
583 int
584 decode_prefix4(netdissect_options *ndo,
585 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
586 {
587 nd_ipv4 addr;
588 u_int plen, plenbytes;
589
590 ITEMCHECK(1);
591 plen = GET_U_1(pptr);
592 if (32 < plen)
593 return -1;
594 itemlen -= 1;
595
596 memset(&addr, 0, sizeof(addr));
597 plenbytes = (plen + 7) / 8;
598 ITEMCHECK(plenbytes);
599 GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
600 if (plen % 8) {
601 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
602 }
603 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
604 return 1 + plenbytes;
605
606 badtlv:
607 return -2;
608 }
609
610 static int
611 decode_labeled_prefix4(netdissect_options *ndo,
612 const u_char *pptr, u_int itemlen, char *buf,
613 size_t buflen)
614 {
615 nd_ipv4 addr;
616 u_int plen, plenbytes;
617
618 /* prefix length and label = 4 bytes */
619 ND_TCHECK_4(pptr);
620 ITEMCHECK(4);
621 plen = GET_U_1(pptr); /* get prefix length */
622
623 /* this is one of the weirdnesses of rfc3107
624 the label length (actually the label + COS bits)
625 is added to the prefix length;
626 we also do only read out just one label -
627 there is no real application for advertisement of
628 stacked labels in a single BGP message
629 */
630
631 if (24 > plen)
632 return -1;
633
634 plen-=24; /* adjust prefixlen - labellength */
635
636 if (32 < plen)
637 return -1;
638 itemlen -= 4;
639
640 memset(&addr, 0, sizeof(addr));
641 plenbytes = (plen + 7) / 8;
642 ITEMCHECK(plenbytes);
643 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
644 if (plen % 8) {
645 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
646 }
647 /* the label may get offsetted by 4 bits so lets shift it right */
648 snprintf(buf, buflen, "%s/%u, label:%u %s",
649 ipaddr_string(ndo, (const u_char *)&addr),
650 plen,
651 GET_BE_U_3(pptr + 1)>>4,
652 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
653
654 return 4 + plenbytes;
655
656 trunc:
657 return -2;
658
659 badtlv:
660 return -3;
661 }
662
663 /*
664 * bgp_vpn_ip_print
665 *
666 * print an ipv4 or ipv6 address into a buffer dependent on address length.
667 */
668 static char *
669 bgp_vpn_ip_print(netdissect_options *ndo,
670 const u_char *pptr, u_int addr_length)
671 {
672
673 /* worst case string is s fully formatted v6 address */
674 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
675 char *pos = addr;
676
677 switch(addr_length) {
678 case (sizeof(nd_ipv4) << 3): /* 32 */
679 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
680 break;
681 case (sizeof(nd_ipv6) << 3): /* 128 */
682 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
683 break;
684 default:
685 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
686 break;
687 }
688 pos += strlen(pos);
689
690 *(pos) = '\0';
691 return (addr);
692 }
693
694 /*
695 * bgp_vpn_sg_print
696 *
697 * print an multicast s,g entry into a buffer.
698 * the s,g entry is encoded like this.
699 *
700 * +-----------------------------------+
701 * | Multicast Source Length (1 octet) |
702 * +-----------------------------------+
703 * | Multicast Source (Variable) |
704 * +-----------------------------------+
705 * | Multicast Group Length (1 octet) |
706 * +-----------------------------------+
707 * | Multicast Group (Variable) |
708 * +-----------------------------------+
709 *
710 * return the number of bytes read from the wire.
711 */
712 static u_int
713 bgp_vpn_sg_print(netdissect_options *ndo,
714 const u_char *pptr, char *buf, size_t buflen)
715 {
716 uint8_t addr_length;
717 u_int total_length, offset;
718
719 total_length = 0;
720
721 /* Source address length, encoded in bits */
722 addr_length = GET_U_1(pptr);
723 pptr++;
724
725 /* Source address */
726 ND_TCHECK_LEN(pptr, (addr_length >> 3));
727 total_length += (addr_length >> 3) + 1;
728 offset = (u_int)strlen(buf);
729 if (addr_length) {
730 snprintf(buf + offset, buflen - offset, ", Source %s",
731 bgp_vpn_ip_print(ndo, pptr, addr_length));
732 pptr += (addr_length >> 3);
733 }
734
735 /* Group address length, encoded in bits */
736 addr_length = GET_U_1(pptr);
737 pptr++;
738
739 /* Group address */
740 ND_TCHECK_LEN(pptr, (addr_length >> 3));
741 total_length += (addr_length >> 3) + 1;
742 offset = (u_int)strlen(buf);
743 if (addr_length) {
744 snprintf(buf + offset, buflen - offset, ", Group %s",
745 bgp_vpn_ip_print(ndo, pptr, addr_length));
746 pptr += (addr_length >> 3);
747 }
748
749 trunc:
750 return (total_length);
751 }
752
753 /* Print an RFC 4364 Route Distinguisher */
754 const char *
755 bgp_vpn_rd_print(netdissect_options *ndo,
756 const u_char *pptr)
757 {
758 /* allocate space for the largest possible string */
759 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
760 char *pos = rd;
761 /* allocate space for the largest possible string */
762 char astostr[AS_STR_SIZE];
763
764 /* ok lets load the RD format */
765 switch (GET_BE_U_2(pptr)) {
766
767 case 0:
768 /* 2-byte-AS:number fmt */
769 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
770 GET_BE_U_2(pptr + 2),
771 GET_BE_U_4(pptr + 4),
772 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
773 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
774 break;
775
776 case 1:
777 /* IP-address:AS fmt */
778 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
779 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
780 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
781 GET_BE_U_2(pptr + 6));
782 break;
783
784 case 2:
785 /* 4-byte-AS:number fmt */
786 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
787 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
788 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
789 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
790 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
791 break;
792 default:
793 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
794 break;
795 }
796 pos += strlen(pos);
797 *(pos) = '\0';
798 return (rd);
799 }
800
801 /*
802 * Print an RFC 4360 Extended Community.
803 */
804 static void
805 bgp_extended_community_print(netdissect_options *ndo,
806 const u_char *pptr)
807 {
808 union { /* copy buffer for bandwidth values */
809 float f;
810 uint32_t i;
811 } bw;
812 /* allocate space for the largest possible string */
813 char astostr[AS_STR_SIZE];
814
815 switch (GET_BE_U_2(pptr)) {
816
817 case BGP_EXT_COM_RT_0:
818 case BGP_EXT_COM_RO_0:
819 case BGP_EXT_COM_L2VPN_RT_0:
820 ND_PRINT("%u:%u (= %s)",
821 GET_BE_U_2(pptr + 2),
822 GET_BE_U_4(pptr + 4),
823 GET_IPADDR_STRING(pptr+4));
824 break;
825
826 case BGP_EXT_COM_RT_1:
827 case BGP_EXT_COM_RO_1:
828 case BGP_EXT_COM_L2VPN_RT_1:
829 case BGP_EXT_COM_VRF_RT_IMP:
830 ND_PRINT("%s:%u",
831 GET_IPADDR_STRING(pptr+2),
832 GET_BE_U_2(pptr + 6));
833 break;
834
835 case BGP_EXT_COM_RT_2:
836 case BGP_EXT_COM_RO_2:
837 ND_PRINT("%s:%u",
838 as_printf(ndo, astostr, sizeof(astostr),
839 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
840 break;
841
842 case BGP_EXT_COM_LINKBAND:
843 bw.i = GET_BE_U_4(pptr + 4);
844 ND_PRINT("bandwidth: %.3f Mbps",
845 bw.f*8/1000000);
846 break;
847
848 case BGP_EXT_COM_VPN_ORIGIN:
849 case BGP_EXT_COM_VPN_ORIGIN2:
850 case BGP_EXT_COM_VPN_ORIGIN3:
851 case BGP_EXT_COM_VPN_ORIGIN4:
852 case BGP_EXT_COM_OSPF_RID:
853 case BGP_EXT_COM_OSPF_RID2:
854 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
855 break;
856
857 case BGP_EXT_COM_OSPF_RTYPE:
858 case BGP_EXT_COM_OSPF_RTYPE2:
859 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
860 GET_IPADDR_STRING(pptr+2),
861 tok2str(bgp_extd_comm_ospf_rtype_values,
862 "unknown (0x%02x)",
863 GET_U_1((pptr + 6))),
864 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
865 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
866 break;
867
868 case BGP_EXT_COM_L2INFO:
869 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
870 tok2str(l2vpn_encaps_values,
871 "unknown encaps",
872 GET_U_1((pptr + 2))),
873 GET_U_1((pptr + 3)),
874 GET_BE_U_2(pptr + 4));
875 break;
876
877 case BGP_EXT_COM_SOURCE_AS:
878 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
879 break;
880
881 case BGP_EXT_COM_ENCAP:
882 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
883 "unknown encaps",
884 GET_BE_U_2(pptr + 6)));
885 break;
886
887 default:
888 ND_PRINT("%02x%02x%02x%02x%02x%02x",
889 GET_U_1(pptr + 2),
890 GET_U_1(pptr + 3),
891 GET_U_1(pptr + 4),
892 GET_U_1(pptr + 5),
893 GET_U_1(pptr + 6),
894 GET_U_1(pptr + 7));
895 break;
896 }
897 }
898
899 /*
900 * RFC4684 (Section 4)/RFC2858 (Section 4).
901 * RTC membership prefix is structured as follows
902 * [prefix-len] [origin-as] [route-target]
903 * The route-target is encoded as RT ext-comms.
904 * Prefix-len may be 0, 32..96
905 *
906 * Note that pptr is not packet data - it is
907 * a buffer owned by our caller - therefore GET_*
908 * macros can not be used.
909 */
910 static char *
911 bgp_rt_prefix_print(netdissect_options *ndo,
912 const u_char *pptr,
913 u_int plen)
914 {
915 /* allocate space for the largest possible string */
916 char rtc_prefix_in_hex[sizeof("0000 0000 0000 0000")] = "";
917 u_int rtc_prefix_in_hex_len = 0;
918 static char output[61]; /* max response string */
919 /* allocate space for the largest possible string */
920 char astostr[AS_STR_SIZE];
921 uint16_t ec_type = 0;
922 u_int octet_count;
923 u_int i;
924
925 if (plen == 0) {
926 snprintf(output, sizeof(output), "route-target: 0:0/0");
927 return (output);
928 }
929
930 /* hex representation of the prefix */
931 octet_count = (plen+7)/8;
932 for (i=0; i<octet_count; i++) {
933 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
934 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
935 "%02x%s", *(pptr+i),
936 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
937 }
938
939 if (plen < 16) {
940 /*
941 * The prefix is too short to include the full ext-comm type,
942 * so we have no way to parse it further.
943 */
944 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
945 rtc_prefix_in_hex, plen);
946 return (output);
947 }
948
949 /*
950 * get the ext-comm type
951 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
952 * hence EXTRACT_*() macros are safe.
953 */
954 ec_type = EXTRACT_BE_U_2(pptr);
955 switch (ec_type) {
956 case BGP_EXT_COM_RT_0:
957 /* 2-byte-AS:number fmt */
958 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
959 EXTRACT_BE_U_2(pptr+2),
960 EXTRACT_BE_U_4(pptr+4),
961 plen, rtc_prefix_in_hex);
962 break;
963
964 case BGP_EXT_COM_RT_1:
965 /* IP-address:AS fmt */
966 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
967 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
968 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
969 break;
970
971 case BGP_EXT_COM_RT_2:
972 /* 4-byte-AS:number fmt */
973 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
974 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
975 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
976 break;
977
978 default:
979 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
980 ec_type,
981 rtc_prefix_in_hex, plen);
982 break;
983 }
984 return (output);
985 }
986
987 /* RFC 4684 */
988 static int
989 decode_rt_routing_info(netdissect_options *ndo,
990 const u_char *pptr)
991 {
992 uint8_t route_target[8];
993 u_int plen;
994 /* allocate space for the largest possible string */
995 char astostr[AS_STR_SIZE];
996 u_int num_octets;
997
998 /* NLRI "prefix length" from RFC 2858 Section 4. */
999 plen = GET_U_1(pptr); /* get prefix length */
1000
1001 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1002 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1003 * target" fields inside the "prefix" depending on its length.
1004 */
1005 if (0 == plen) {
1006 /* Without "origin AS", without "route target". */
1007 ND_PRINT("\n\t default route target");
1008 return 1;
1009 }
1010
1011 if (32 > plen) {
1012 ND_PRINT("\n\t (illegal prefix length)");
1013 return -1;
1014 }
1015
1016 /* With at least "origin AS", possibly with "route target". */
1017 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
1018
1019 plen -= 32; /* adjust prefix length */
1020
1021 if (64 < plen) {
1022 ND_PRINT("\n\t (illegal prefix length)");
1023 return -1;
1024 }
1025
1026 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1027 * and gives the number of octets in the variable-length "route
1028 * target" field inside this NLRI "prefix". Look for it.
1029 */
1030 memset(&route_target, 0, sizeof(route_target));
1031 num_octets = (plen + 7) / 8;
1032 GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
1033 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1034 if (plen % 8) {
1035 ((u_char *)&route_target)[num_octets - 1] &=
1036 ((0xff00 >> (plen % 8)) & 0xff);
1037 }
1038 ND_PRINT("\n\t origin AS: %s, %s",
1039 astostr,
1040 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1041
1042 return 5 + num_octets;
1043 }
1044
1045 static int
1046 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1047 const u_char *pptr, char *buf, size_t buflen)
1048 {
1049 nd_ipv4 addr;
1050 u_int plen;
1051
1052 plen = GET_U_1(pptr); /* get prefix length */
1053
1054 if ((24+64) > plen)
1055 return -1;
1056
1057 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1058
1059 if (32 < plen)
1060 return -1;
1061
1062 memset(&addr, 0, sizeof(addr));
1063 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1064 if (plen % 8) {
1065 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1066 ((0xff00 >> (plen % 8)) & 0xff);
1067 }
1068 /* the label may get offsetted by 4 bits so lets shift it right */
1069 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1070 bgp_vpn_rd_print(ndo, pptr+4),
1071 ipaddr_string(ndo, (const u_char *)&addr),
1072 plen,
1073 GET_BE_U_3(pptr + 1)>>4,
1074 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1075
1076 return 12 + (plen + 7) / 8;
1077 }
1078
1079 /*
1080 * +-------------------------------+
1081 * | |
1082 * | RD:IPv4-address (12 octets) |
1083 * | |
1084 * +-------------------------------+
1085 * | MDT Group-address (4 octets) |
1086 * +-------------------------------+
1087 */
1088
1089 #define MDT_VPN_NLRI_LEN 16
1090
1091 static int
1092 decode_mdt_vpn_nlri(netdissect_options *ndo,
1093 const u_char *pptr, char *buf, size_t buflen)
1094 {
1095 const u_char *rd;
1096 const u_char *vpn_ip;
1097
1098 /* if the NLRI is not predefined length, quit.*/
1099 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1100 return -1;
1101 pptr++;
1102
1103 /* RD */
1104 ND_TCHECK_8(pptr);
1105 rd = pptr;
1106 pptr += 8;
1107
1108 /* IPv4 address */
1109 vpn_ip = pptr;
1110 pptr += sizeof(nd_ipv4);
1111
1112 /* MDT Group Address */
1113 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1114 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1115
1116 return MDT_VPN_NLRI_LEN + 1;
1117
1118 trunc:
1119 return -2;
1120 }
1121
1122 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1123 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1124 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1125 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1126 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1127 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1128 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1129
1130 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1131 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1132 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1133 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1134 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1135 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1136 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1137 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1138 { 0, NULL}
1139 };
1140
1141 static int
1142 decode_multicast_vpn(netdissect_options *ndo,
1143 const u_char *pptr, char *buf, size_t buflen)
1144 {
1145 /* allocate space for the largest possible string */
1146 char astostr[AS_STR_SIZE];
1147 uint8_t route_type, route_length;
1148 u_int addr_length, sg_length;
1149 u_int offset;
1150
1151 route_type = GET_U_1(pptr);
1152 pptr++;
1153 route_length = GET_U_1(pptr);
1154 pptr++;
1155
1156 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1157 tok2str(bgp_multicast_vpn_route_type_values,
1158 "Unknown", route_type),
1159 route_type, route_length);
1160
1161 switch(route_type) {
1162 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1163 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1164 if (route_length < BGP_VPN_RD_LEN)
1165 goto trunc;
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 caller 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 assumption 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,
2237 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2238 add_path6 = check_add_path(ndo, tptr,
2239 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2240
2241 while (tptr < pptr + len) {
2242 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2243 add_path4, add_path6);
2244 if (advance == -2)
2245 goto trunc;
2246 if (advance < 0)
2247 break;
2248 tptr += advance;
2249 }
2250 break;
2251
2252 case BGPTYPE_MP_UNREACH_NLRI:
2253 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2254 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2255 if (ret == -2)
2256 goto trunc;
2257 if (ret < 0)
2258 break;
2259
2260 if (len == BGP_MP_NLRI_MINSIZE)
2261 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2262
2263 tptr += 3;
2264
2265 add_path4 = check_add_path(ndo, tptr,
2266 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2267 add_path6 = check_add_path(ndo, tptr,
2268 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2269
2270 while (tptr < pptr + len) {
2271 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2272 add_path4, add_path6);
2273 if (advance == -2)
2274 goto trunc;
2275 if (advance < 0)
2276 break;
2277 tptr += advance;
2278 }
2279 break;
2280 case BGPTYPE_EXTD_COMMUNITIES:
2281 if (len % 8) {
2282 ND_PRINT("invalid len");
2283 break;
2284 }
2285 while (tlen != 0) {
2286 uint16_t extd_comm;
2287
2288 ND_TCHECK_2(tptr);
2289 if (tlen < 2)
2290 goto trunc;
2291 extd_comm=GET_BE_U_2(tptr);
2292
2293 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2294 tok2str(bgp_extd_comm_subtype_values,
2295 "unknown extd community typecode",
2296 extd_comm),
2297 extd_comm,
2298 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2299
2300 ND_TCHECK_8(tptr);
2301 if (tlen < 8)
2302 goto trunc;
2303 ND_PRINT(": ");
2304 bgp_extended_community_print(ndo, tptr);
2305 tlen -= 8;
2306 tptr += 8;
2307 }
2308 break;
2309
2310 case BGPTYPE_PMSI_TUNNEL:
2311 {
2312 uint8_t tunnel_type, flags;
2313
2314 ND_TCHECK_5(tptr);
2315 if (tlen < 5)
2316 goto trunc;
2317 flags = GET_U_1(tptr);
2318 tunnel_type = GET_U_1(tptr + 1);
2319
2320 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2321 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2322 tunnel_type,
2323 bittok2str(bgp_pmsi_flag_values, "none", flags),
2324 GET_BE_U_3(tptr + 2)>>4);
2325
2326 tptr +=5;
2327 tlen -= 5;
2328
2329 switch (tunnel_type) {
2330 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2331 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2332 ND_PRINT("\n\t Sender %s, P-Group %s",
2333 GET_IPADDR_STRING(tptr),
2334 GET_IPADDR_STRING(tptr+4));
2335 break;
2336
2337 case BGP_PMSI_TUNNEL_PIM_SSM:
2338 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2339 GET_IPADDR_STRING(tptr),
2340 GET_IPADDR_STRING(tptr+4));
2341 break;
2342 case BGP_PMSI_TUNNEL_INGRESS:
2343 ND_PRINT("\n\t Tunnel-Endpoint %s",
2344 GET_IPADDR_STRING(tptr));
2345 break;
2346 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2347 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2348 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2349 GET_IPADDR_STRING(tptr),
2350 GET_BE_U_4(tptr + 4));
2351 break;
2352 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2353 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2354 GET_IPADDR_STRING(tptr),
2355 GET_BE_U_4(tptr + 4));
2356 break;
2357 default:
2358 if (ndo->ndo_vflag <= 1) {
2359 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2360 }
2361 }
2362 break;
2363 }
2364 case BGPTYPE_AIGP:
2365 {
2366 uint8_t type;
2367 uint16_t length;
2368
2369 while (tlen >= 3) {
2370 type = GET_U_1(tptr);
2371 length = GET_BE_U_2(tptr + 1);
2372 tptr += 3;
2373 tlen -= 3;
2374
2375 ND_PRINT("\n\t %s TLV (%u), length %u",
2376 tok2str(bgp_aigp_values, "Unknown", type),
2377 type, length);
2378
2379 if (length < 3)
2380 goto trunc;
2381 length -= 3;
2382
2383 /*
2384 * Check if we can read the TLV data.
2385 */
2386 if (tlen < length)
2387 goto trunc;
2388
2389 switch (type) {
2390
2391 case BGP_AIGP_TLV:
2392 if (length < 8)
2393 goto trunc;
2394 ND_PRINT(", metric %" PRIu64,
2395 GET_BE_U_8(tptr));
2396 break;
2397
2398 default:
2399 if (ndo->ndo_vflag <= 1) {
2400 print_unknown_data(ndo, tptr,"\n\t ", length);
2401 }
2402 }
2403
2404 tptr += length;
2405 tlen -= length;
2406 }
2407 break;
2408 }
2409 case BGPTYPE_ATTR_SET:
2410 ND_TCHECK_4(tptr);
2411 if (len < 4)
2412 goto trunc;
2413 ND_PRINT("\n\t Origin AS: %s",
2414 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2415 tptr += 4;
2416 len -= 4;
2417
2418 while (len) {
2419 u_int aflags, alenlen, alen;
2420
2421 ND_TCHECK_2(tptr);
2422 if (len < 2) {
2423 ND_PRINT(" [path attr too short]");
2424 tptr += len;
2425 break;
2426 }
2427 aflags = GET_U_1(tptr);
2428 atype = GET_U_1(tptr + 1);
2429 tptr += 2;
2430 len -= 2;
2431 alenlen = bgp_attr_lenlen(aflags, tptr);
2432 ND_TCHECK_LEN(tptr, alenlen);
2433 if (len < alenlen) {
2434 ND_PRINT(" [path attr too short]");
2435 tptr += len;
2436 break;
2437 }
2438 alen = bgp_attr_len(aflags, tptr);
2439 tptr += alenlen;
2440 len -= alenlen;
2441
2442 ND_PRINT("\n\t %s (%u), length: %u",
2443 tok2str(bgp_attr_values,
2444 "Unknown Attribute", atype),
2445 atype,
2446 alen);
2447
2448 if (aflags) {
2449 ND_PRINT(", Flags [%s%s%s%s",
2450 aflags & 0x80 ? "O" : "",
2451 aflags & 0x40 ? "T" : "",
2452 aflags & 0x20 ? "P" : "",
2453 aflags & 0x10 ? "E" : "");
2454 if (aflags & 0xf)
2455 ND_PRINT("+%x", aflags & 0xf);
2456 ND_PRINT("]");
2457 }
2458 ND_PRINT(": ");
2459 if (len < alen) {
2460 ND_PRINT(" [path attr too short]");
2461 tptr += len;
2462 break;
2463 }
2464 /*
2465 * The protocol encoding per se allows ATTR_SET to be nested
2466 * as many times as the message can accommodate. This printer
2467 * used to be able to recurse into ATTR_SET contents until the
2468 * stack exhaustion, but now there is a limit on that (if live
2469 * protocol exchange goes that many levels deep, something is
2470 * probably wrong anyway). Feel free to refine this value if
2471 * you can find the spec with respective normative text.
2472 */
2473 if (attr_set_level == 10)
2474 ND_PRINT("(too many nested levels, not recursing)");
2475 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2476 return 0;
2477 tptr += alen;
2478 len -= alen;
2479 }
2480 break;
2481
2482 case BGPTYPE_LARGE_COMMUNITY:
2483 if (len == 0 || len % 12) {
2484 ND_PRINT("invalid len");
2485 break;
2486 }
2487 ND_PRINT("\n\t ");
2488 while (len != 0) {
2489 ND_PRINT("%u:%u:%u%s",
2490 GET_BE_U_4(tptr),
2491 GET_BE_U_4(tptr + 4),
2492 GET_BE_U_4(tptr + 8),
2493 (len > 12) ? ", " : "");
2494 tptr += 12;
2495 /*
2496 * len will always be a multiple of 12, as per the above,
2497 * so this will never underflow.
2498 */
2499 len -= 12;
2500 }
2501 break;
2502 default:
2503 ND_TCHECK_LEN(pptr, len);
2504 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2505 if (ndo->ndo_vflag <= 1)
2506 print_unknown_data(ndo, pptr, "\n\t ", len);
2507 break;
2508 }
2509 done:
2510 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2511 ND_TCHECK_LEN(pptr, len);
2512 print_unknown_data(ndo, pptr, "\n\t ", len);
2513 }
2514 return 1;
2515
2516 trunc:
2517 return 0;
2518 }
2519
2520 static void
2521 bgp_capabilities_print(netdissect_options *ndo,
2522 const u_char *opt, u_int caps_len)
2523 {
2524 /* allocate space for the largest possible string */
2525 char astostr[AS_STR_SIZE];
2526 u_int cap_type, cap_len, tcap_len, cap_offset;
2527 u_int i = 0;
2528
2529 while (i < caps_len) {
2530 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2531 cap_type=GET_U_1(opt + i);
2532 cap_len=GET_U_1(opt + i + 1);
2533 ND_PRINT("\n\t %s (%u), length: %u",
2534 tok2str(bgp_capcode_values, "Unknown", cap_type),
2535 cap_type,
2536 cap_len);
2537 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2538 switch (cap_type) {
2539 case BGP_CAPCODE_MP:
2540 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2541 if (cap_len < 4) {
2542 ND_PRINT(" (too short, < 4)");
2543 return;
2544 }
2545 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2546 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2547 GET_BE_U_2(opt + i + 2),
2548 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2549 GET_U_1(opt + i + 5));
2550 break;
2551 case BGP_CAPCODE_ML:
2552 cap_offset = 2;
2553 tcap_len = cap_len;
2554 while (tcap_len >= 4) {
2555 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2556 tok2str(af_values, "Unknown",
2557 GET_BE_U_2(opt + i + cap_offset)),
2558 GET_BE_U_2(opt + i + cap_offset),
2559 tok2str(bgp_safi_values, "Unknown",
2560 GET_U_1(opt + i + cap_offset + 2)),
2561 GET_U_1(opt + i + cap_offset + 2),
2562 GET_U_1(opt + i + cap_offset + 3));
2563 tcap_len -= 4;
2564 cap_offset += 4;
2565 }
2566 break;
2567 case BGP_CAPCODE_RESTART:
2568 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2569 if (cap_len < 2) {
2570 ND_PRINT(" (too short, < 2)");
2571 return;
2572 }
2573 tcap_len=cap_len;
2574 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2575 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2576 GET_BE_U_2(opt + i + 2)&0xfff);
2577 tcap_len-=2;
2578 cap_offset=4;
2579 while(tcap_len>=4) {
2580 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2581 tok2str(af_values,"Unknown",
2582 GET_BE_U_2(opt + i + cap_offset)),
2583 GET_BE_U_2(opt + i + cap_offset),
2584 tok2str(bgp_safi_values,"Unknown",
2585 GET_U_1(opt + i + cap_offset + 2)),
2586 GET_U_1(opt + (i + cap_offset + 2)),
2587 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2588 tcap_len -= 4;
2589 cap_offset += 4;
2590 }
2591 break;
2592 case BGP_CAPCODE_RR:
2593 case BGP_CAPCODE_LLGR:
2594 case BGP_CAPCODE_RR_CISCO:
2595 break;
2596 case BGP_CAPCODE_AS_NEW:
2597 /*
2598 * Extract the 4 byte AS number encoded.
2599 */
2600 if (cap_len < 4) {
2601 ND_PRINT(" (too short, < 4)");
2602 return;
2603 }
2604 ND_PRINT("\n\t\t 4 Byte AS %s",
2605 as_printf(ndo, astostr, sizeof(astostr),
2606 GET_BE_U_4(opt + i + 2)));
2607 break;
2608 case BGP_CAPCODE_ADD_PATH:
2609 if (cap_len == 0) {
2610 ND_PRINT(" (bogus)"); /* length */
2611 break;
2612 }
2613 tcap_len=cap_len;
2614 cap_offset=2;
2615 while (tcap_len != 0) {
2616 if (tcap_len < 4) {
2617 nd_print_invalid(ndo);
2618 break;
2619 }
2620 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2621 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2622 GET_BE_U_2(opt + i + cap_offset),
2623 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2624 GET_U_1(opt + (i + cap_offset + 2)),
2625 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2626 );
2627 tcap_len -= 4;
2628 cap_offset += 4;
2629 }
2630 break;
2631 default:
2632 ND_PRINT("\n\t\tno decoder for Capability %u",
2633 cap_type);
2634 if (ndo->ndo_vflag <= 1)
2635 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2636 cap_len);
2637 break;
2638 }
2639 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2640 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2641 }
2642 i += BGP_CAP_HEADER_SIZE + cap_len;
2643 }
2644 return;
2645
2646 trunc:
2647 nd_print_trunc(ndo);
2648 }
2649
2650 static void
2651 bgp_open_print(netdissect_options *ndo,
2652 const u_char *dat, u_int length)
2653 {
2654 /* allocate space for the largest possible string */
2655 char astostr[AS_STR_SIZE];
2656 const struct bgp_open *bgp_open_header;
2657 u_int optslen;
2658 const struct bgp_opt *bgpopt;
2659 const u_char *opt;
2660 u_int i;
2661
2662 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2663 if (length < BGP_OPEN_SIZE)
2664 goto trunc;
2665
2666 bgp_open_header = (const struct bgp_open *)dat;
2667
2668 ND_PRINT("\n\t Version %u, ",
2669 GET_U_1(bgp_open_header->bgpo_version));
2670 ND_PRINT("my AS %s, ",
2671 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2672 ND_PRINT("Holdtime %us, ",
2673 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2674 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2675 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2676 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2677
2678 opt = dat + BGP_OPEN_SIZE;
2679 length -= BGP_OPEN_SIZE;
2680
2681 i = 0;
2682 while (i < optslen) {
2683 uint8_t opt_type, opt_len;
2684
2685 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2686 if (length < BGP_OPT_SIZE + i)
2687 goto trunc;
2688 bgpopt = (const struct bgp_opt *)(opt + i);
2689 opt_type = GET_U_1(bgpopt->bgpopt_type);
2690 opt_len = GET_U_1(bgpopt->bgpopt_len);
2691 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2692 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2693 opt_type, opt_len);
2694 break;
2695 }
2696
2697 ND_PRINT("\n\t Option %s (%u), length: %u",
2698 tok2str(bgp_opt_values,"Unknown",opt_type),
2699 opt_type,
2700 opt_len);
2701
2702 /* now let's decode the options we know*/
2703 switch(opt_type) {
2704
2705 case BGP_OPT_CAP:
2706 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2707 opt_len);
2708 break;
2709
2710 case BGP_OPT_AUTH:
2711 default:
2712 ND_PRINT("\n\t no decoder for option %u",
2713 opt_type);
2714 break;
2715 }
2716 i += BGP_OPT_SIZE + opt_len;
2717 }
2718 return;
2719 trunc:
2720 nd_print_trunc(ndo);
2721 }
2722
2723 static void
2724 bgp_update_print(netdissect_options *ndo,
2725 const u_char *dat, u_int length)
2726 {
2727 const u_char *p;
2728 u_int withdrawn_routes_len;
2729 char buf[MAXHOSTNAMELEN + 100];
2730 int wpfx;
2731 u_int len;
2732 int i;
2733 int add_path;
2734 u_int path_id = 0;
2735
2736 ND_TCHECK_LEN(dat, BGP_SIZE);
2737 if (length < BGP_SIZE)
2738 goto trunc;
2739 p = dat + BGP_SIZE;
2740 length -= BGP_SIZE;
2741
2742 /* Unfeasible routes */
2743 ND_TCHECK_2(p);
2744 if (length < 2)
2745 goto trunc;
2746 withdrawn_routes_len = GET_BE_U_2(p);
2747 p += 2;
2748 length -= 2;
2749 if (withdrawn_routes_len > 1) {
2750 /*
2751 * Without keeping state from the original NLRI message,
2752 * it's not possible to tell if this a v4 or v6 route,
2753 * so only try to decode it if we're not v6 enabled.
2754 */
2755 ND_TCHECK_LEN(p, withdrawn_routes_len);
2756 if (length < withdrawn_routes_len)
2757 goto trunc;
2758 ND_PRINT("\n\t Withdrawn routes:");
2759 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2760 while (withdrawn_routes_len != 0) {
2761 if (add_path) {
2762 if (withdrawn_routes_len < 4) {
2763 p += withdrawn_routes_len;
2764 length -= withdrawn_routes_len;
2765 break;
2766 }
2767 path_id = GET_BE_U_4(p);
2768 p += 4;
2769 length -= 4;
2770 withdrawn_routes_len -= 4;
2771 }
2772 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2773 if (wpfx == -1) {
2774 ND_PRINT("\n\t (illegal prefix length)");
2775 break;
2776 } else if (wpfx == -2)
2777 goto trunc; /* bytes left, but not enough */
2778 else {
2779 ND_PRINT("\n\t %s", buf);
2780 if (add_path) {
2781 ND_PRINT(" Path Id: %u", path_id);
2782 }
2783 p += wpfx;
2784 length -= wpfx;
2785 withdrawn_routes_len -= wpfx;
2786 }
2787 }
2788 } else {
2789 ND_TCHECK_LEN(p, withdrawn_routes_len);
2790 if (length < withdrawn_routes_len)
2791 goto trunc;
2792 p += withdrawn_routes_len;
2793 length -= withdrawn_routes_len;
2794 }
2795
2796 ND_TCHECK_2(p);
2797 if (length < 2)
2798 goto trunc;
2799 len = GET_BE_U_2(p);
2800 p += 2;
2801 length -= 2;
2802
2803 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2804 /* No withdrawn routes, no path attributes, no NLRI */
2805 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2806 return;
2807 }
2808
2809 if (len) {
2810 /* Make sure the path attributes don't go past the end of the packet */
2811 if (length < len)
2812 goto trunc;
2813 /* do something more useful!*/
2814 while (len) {
2815 uint8_t aflags, atype, alenlen;
2816 uint16_t alen;
2817
2818 ND_TCHECK_2(p);
2819 if (length < 2)
2820 goto trunc;
2821 if (len < 2) {
2822 ND_PRINT("\n\t [path attrs too short]");
2823 p += len;
2824 length -= len;
2825 break;
2826 }
2827 aflags = GET_U_1(p);
2828 atype = GET_U_1(p + 1);
2829 p += 2;
2830 len -= 2;
2831 length -= 2;
2832 alenlen = bgp_attr_lenlen(aflags, p);
2833 ND_TCHECK_LEN(p, alenlen);
2834 if (length < alenlen)
2835 goto trunc;
2836 if (len < alenlen) {
2837 ND_PRINT("\n\t [path attrs too short]");
2838 p += len;
2839 length -= len;
2840 break;
2841 }
2842 alen = bgp_attr_len(aflags, p);
2843 p += alenlen;
2844 len -= alenlen;
2845 length -= alenlen;
2846
2847 ND_PRINT("\n\t %s (%u), length: %u",
2848 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2849 atype,
2850 alen);
2851
2852 if (aflags) {
2853 ND_PRINT(", Flags [%s%s%s%s",
2854 aflags & 0x80 ? "O" : "",
2855 aflags & 0x40 ? "T" : "",
2856 aflags & 0x20 ? "P" : "",
2857 aflags & 0x10 ? "E" : "");
2858 if (aflags & 0xf)
2859 ND_PRINT("+%x", aflags & 0xf);
2860 ND_PRINT("]: ");
2861 }
2862 if (len < alen) {
2863 ND_PRINT(" [path attrs too short]");
2864 p += len;
2865 length -= len;
2866 break;
2867 }
2868 if (length < alen)
2869 goto trunc;
2870 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2871 goto trunc;
2872 p += alen;
2873 len -= alen;
2874 length -= alen;
2875 }
2876 }
2877
2878 if (length) {
2879 add_path = check_add_path(ndo, p, length, 32);
2880 ND_PRINT("\n\t Updated routes:");
2881 while (length != 0) {
2882 if (add_path) {
2883 ND_TCHECK_4(p);
2884 if (length < 4)
2885 goto trunc;
2886 path_id = GET_BE_U_4(p);
2887 p += 4;
2888 length -= 4;
2889 }
2890 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2891 if (i == -1) {
2892 ND_PRINT("\n\t (illegal prefix length)");
2893 break;
2894 } else if (i == -2)
2895 goto trunc; /* bytes left, but not enough */
2896 else {
2897 ND_PRINT("\n\t %s", buf);
2898 if (add_path) {
2899 ND_PRINT(" Path Id: %u", path_id);
2900 }
2901 p += i;
2902 length -= i;
2903 }
2904 }
2905 }
2906 return;
2907 trunc:
2908 nd_print_trunc(ndo);
2909 }
2910
2911 static void
2912 bgp_notification_print(netdissect_options *ndo,
2913 const u_char *dat, u_int length)
2914 {
2915 const struct bgp_notification *bgp_notification_header;
2916 const u_char *tptr;
2917 uint8_t bgpn_major, bgpn_minor;
2918
2919 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2920 if (length<BGP_NOTIFICATION_SIZE)
2921 return;
2922
2923 bgp_notification_header = (const struct bgp_notification *)dat;
2924 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
2925 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
2926
2927 ND_PRINT(", %s (%u)",
2928 tok2str(bgp_notify_major_values, "Unknown Error",
2929 bgpn_major),
2930 bgpn_major);
2931
2932 switch (bgpn_major) {
2933
2934 case BGP_NOTIFY_MAJOR_MSG:
2935 ND_PRINT(", subcode %s (%u)",
2936 tok2str(bgp_notify_minor_msg_values, "Unknown",
2937 bgpn_minor),
2938 bgpn_minor);
2939 break;
2940 case BGP_NOTIFY_MAJOR_OPEN:
2941 ND_PRINT(", subcode %s (%u)",
2942 tok2str(bgp_notify_minor_open_values, "Unknown",
2943 bgpn_minor),
2944 bgpn_minor);
2945 break;
2946 case BGP_NOTIFY_MAJOR_UPDATE:
2947 ND_PRINT(", subcode %s (%u)",
2948 tok2str(bgp_notify_minor_update_values, "Unknown",
2949 bgpn_minor),
2950 bgpn_minor);
2951 break;
2952 case BGP_NOTIFY_MAJOR_FSM:
2953 ND_PRINT(" subcode %s (%u)",
2954 tok2str(bgp_notify_minor_fsm_values, "Unknown",
2955 bgpn_minor),
2956 bgpn_minor);
2957 break;
2958 case BGP_NOTIFY_MAJOR_CAP:
2959 ND_PRINT(" subcode %s (%u)",
2960 tok2str(bgp_notify_minor_cap_values, "Unknown",
2961 bgpn_minor),
2962 bgpn_minor);
2963 break;
2964 case BGP_NOTIFY_MAJOR_CEASE:
2965 ND_PRINT(", subcode %s (%u)",
2966 tok2str(bgp_notify_minor_cease_values, "Unknown",
2967 bgpn_minor),
2968 bgpn_minor);
2969
2970 /* RFC 4486 mentions optionally 7 bytes
2971 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
2972 */
2973 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
2974 tptr = dat + BGP_NOTIFICATION_SIZE;
2975 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
2976 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
2977 GET_BE_U_2(tptr),
2978 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
2979 GET_U_1((tptr + 2)),
2980 GET_BE_U_4(tptr + 3));
2981 }
2982 /*
2983 * RFC 9003 describes a method to send a communication
2984 * intended for human consumption regarding the Administrative Shutdown
2985 */
2986 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
2987 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
2988 length >= BGP_NOTIFICATION_SIZE + 1) {
2989 tptr = dat + BGP_NOTIFICATION_SIZE;
2990 uint8_t shutdown_comm_length = GET_U_1(tptr);
2991 uint8_t remainder_offset = 0;
2992 /* garbage, hexdump it all */
2993 if (shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
2994 ND_PRINT(", invalid Shutdown Communication length");
2995 } else if (shutdown_comm_length == 0) {
2996 ND_PRINT(", empty Shutdown Communication");
2997 remainder_offset += 1;
2998 }
2999 /* a proper shutdown communication */
3000 else {
3001 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3002 (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL);
3003 ND_PRINT("\"");
3004 remainder_offset += shutdown_comm_length + 1;
3005 }
3006 /* if there is trailing data, hexdump it */
3007 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3008 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3009 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3010 }
3011 }
3012 break;
3013 default:
3014 break;
3015 }
3016
3017 return;
3018 trunc:
3019 nd_print_trunc(ndo);
3020 }
3021
3022 static void
3023 bgp_route_refresh_print(netdissect_options *ndo,
3024 const u_char *pptr, u_int len)
3025 {
3026 const struct bgp_route_refresh *bgp_route_refresh_header;
3027
3028 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3029
3030 /* some little sanity checking */
3031 if (len<BGP_ROUTE_REFRESH_SIZE)
3032 return;
3033
3034 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3035
3036 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3037 tok2str(af_values,"Unknown",
3038 GET_BE_U_2(bgp_route_refresh_header->afi)),
3039 GET_BE_U_2(bgp_route_refresh_header->afi),
3040 tok2str(bgp_safi_values,"Unknown",
3041 GET_U_1(bgp_route_refresh_header->safi)),
3042 GET_U_1(bgp_route_refresh_header->safi));
3043
3044 if (ndo->ndo_vflag > 1) {
3045 ND_TCHECK_LEN(pptr, len);
3046 print_unknown_data(ndo, pptr, "\n\t ", len);
3047 }
3048
3049 return;
3050 trunc:
3051 nd_print_trunc(ndo);
3052 }
3053
3054 static int
3055 bgp_pdu_print(netdissect_options *ndo,
3056 const u_char *dat, u_int length)
3057 {
3058 const struct bgp *bgp_header;
3059 uint8_t bgp_type;
3060
3061 ND_TCHECK_LEN(dat, BGP_SIZE);
3062 bgp_header = (const struct bgp *)dat;
3063 bgp_type = GET_U_1(bgp_header->bgp_type);
3064
3065 ND_PRINT("\n\t%s Message (%u), length: %u",
3066 tok2str(bgp_msg_values, "Unknown", bgp_type),
3067 bgp_type,
3068 length);
3069
3070 switch (bgp_type) {
3071 case BGP_OPEN:
3072 bgp_open_print(ndo, dat, length);
3073 break;
3074 case BGP_UPDATE:
3075 bgp_update_print(ndo, dat, length);
3076 break;
3077 case BGP_NOTIFICATION:
3078 bgp_notification_print(ndo, dat, length);
3079 break;
3080 case BGP_KEEPALIVE:
3081 break;
3082 case BGP_ROUTE_REFRESH:
3083 bgp_route_refresh_print(ndo, dat, length);
3084 break;
3085 default:
3086 /* we have no decoder for the BGP message */
3087 ND_TCHECK_LEN(dat, length);
3088 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3089 print_unknown_data(ndo, dat, "\n\t ", length);
3090 break;
3091 }
3092 return 1;
3093 trunc:
3094 nd_print_trunc(ndo);
3095 return 0;
3096 }
3097
3098 void
3099 bgp_print(netdissect_options *ndo,
3100 const u_char *dat, u_int length _U_)
3101 {
3102 const u_char *p;
3103 const u_char *ep = ndo->ndo_snapend;
3104 const u_char *start;
3105 const u_char marker[] = {
3106 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3107 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3108 };
3109 const struct bgp *bgp_header;
3110 uint16_t hlen;
3111
3112 ndo->ndo_protocol = "bgp";
3113 ND_PRINT(": BGP");
3114
3115 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3116 return;
3117
3118 p = dat;
3119 start = p;
3120 while (p < ep) {
3121 if (!ND_TTEST_1(p))
3122 break;
3123 if (GET_U_1(p) != 0xff) {
3124 p++;
3125 continue;
3126 }
3127
3128 if (!ND_TTEST_LEN(p, sizeof(marker)))
3129 break;
3130 if (memcmp(p, marker, sizeof(marker)) != 0) {
3131 p++;
3132 continue;
3133 }
3134
3135 /* found BGP header */
3136 ND_TCHECK_LEN(p, BGP_SIZE);
3137 bgp_header = (const struct bgp *)p;
3138
3139 if (start != p)
3140 nd_print_trunc(ndo);
3141
3142 hlen = GET_BE_U_2(bgp_header->bgp_len);
3143 if (hlen < BGP_SIZE) {
3144 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3145 nd_print_invalid(ndo);
3146 break;
3147 }
3148
3149 if (ND_TTEST_LEN(p, hlen)) {
3150 if (!bgp_pdu_print(ndo, p, hlen))
3151 return;
3152 p += hlen;
3153 start = p;
3154 } else {
3155 ND_PRINT("\n[|BGP %s]",
3156 tok2str(bgp_msg_values,
3157 "Unknown Message Type",
3158 GET_U_1(bgp_header->bgp_type)));
3159 break;
3160 }
3161 }
3162
3163 return;
3164
3165 trunc:
3166 nd_print_trunc(ndo);
3167 }
[mirror] the TCPdump network dissector