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CHANGES: Add changes backported to 4.99
[tcpdump] / print-bgp.c
1 /*
2 * Copyright (C) 1999 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * Extensively modified by Hannes Gredler (hannes@gredler.at) for more
30 * complete BGP support.
31 */
32
33 /* \summary: Border Gateway Protocol (BGP) printer */
34
35 /* specification: RFC 4271 */
36
37 #include <config.h>
38
39 #include "netdissect-stdinc.h"
40
41 #include <stdio.h>
42 #include <string.h>
43
44 #include "netdissect.h"
45 #include "addrtoname.h"
46 #include "extract.h"
47 #include "af.h"
48 #include "l2vpn.h"
49
50 struct bgp {
51 nd_byte bgp_marker[16];
52 nd_uint16_t bgp_len;
53 nd_uint8_t bgp_type;
54 };
55 #define BGP_SIZE 19 /* unaligned */
56
57 #define BGP_OPEN 1
58 #define BGP_UPDATE 2
59 #define BGP_NOTIFICATION 3
60 #define BGP_KEEPALIVE 4
61 #define BGP_ROUTE_REFRESH 5
62
63 static const struct tok bgp_msg_values[] = {
64 { BGP_OPEN, "Open"},
65 { BGP_UPDATE, "Update"},
66 { BGP_NOTIFICATION, "Notification"},
67 { BGP_KEEPALIVE, "Keepalive"},
68 { BGP_ROUTE_REFRESH, "Route Refresh"},
69 { 0, NULL}
70 };
71
72 struct bgp_open {
73 nd_byte bgpo_marker[16];
74 nd_uint16_t bgpo_len;
75 nd_uint8_t bgpo_type;
76 nd_uint8_t bgpo_version;
77 nd_uint16_t bgpo_myas;
78 nd_uint16_t bgpo_holdtime;
79 nd_uint32_t bgpo_id;
80 nd_uint8_t bgpo_optlen;
81 /* options should follow */
82 };
83 #define BGP_OPEN_SIZE 29 /* unaligned */
84
85 struct bgp_opt {
86 nd_uint8_t bgpopt_type;
87 nd_uint8_t bgpopt_len;
88 /* variable length */
89 };
90 #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
91 #define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */
92
93 struct bgp_notification {
94 nd_byte bgpn_marker[16];
95 nd_uint16_t bgpn_len;
96 nd_uint8_t bgpn_type;
97 nd_uint8_t bgpn_major;
98 nd_uint8_t bgpn_minor;
99 };
100 #define BGP_NOTIFICATION_SIZE 21 /* unaligned */
101
102 struct bgp_route_refresh {
103 nd_byte bgp_marker[16];
104 nd_uint16_t len;
105 nd_uint8_t type; /* No padding after this; afi is, in fact, not aligned */
106 nd_uint16_t afi;
107 nd_uint8_t res;
108 nd_uint8_t safi;
109 };
110 #define BGP_ROUTE_REFRESH_SIZE 23
111
112 #define bgp_attr_lenlen(flags, p) \
113 (((flags) & 0x10) ? 2U : 1U)
114 #define bgp_attr_len(flags, p) \
115 (((flags) & 0x10) ? GET_BE_U_2(p) : GET_U_1(p))
116
117 #define BGPTYPE_ORIGIN 1
118 #define BGPTYPE_AS_PATH 2
119 #define BGPTYPE_NEXT_HOP 3
120 #define BGPTYPE_MULTI_EXIT_DISC 4
121 #define BGPTYPE_LOCAL_PREF 5
122 #define BGPTYPE_ATOMIC_AGGREGATE 6
123 #define BGPTYPE_AGGREGATOR 7
124 #define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
125 #define BGPTYPE_ORIGINATOR_ID 9 /* RFC4456 */
126 #define BGPTYPE_CLUSTER_LIST 10 /* RFC4456 */
127 #define BGPTYPE_DPA 11 /* deprecated, draft-ietf-idr-bgp-dpa */
128 #define BGPTYPE_ADVERTISERS 12 /* deprecated RFC1863 */
129 #define BGPTYPE_RCID_PATH 13 /* deprecated RFC1863 */
130 #define BGPTYPE_MP_REACH_NLRI 14 /* RFC4760 */
131 #define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC4760 */
132 #define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
133 #define BGPTYPE_AS4_PATH 17 /* RFC6793 */
134 #define BGPTYPE_AGGREGATOR4 18 /* RFC6793 */
135 #define BGPTYPE_PMSI_TUNNEL 22 /* RFC6514 */
136 #define BGPTYPE_TUNNEL_ENCAP 23 /* RFC5512 */
137 #define BGPTYPE_TRAFFIC_ENG 24 /* RFC5543 */
138 #define BGPTYPE_IPV6_EXTD_COMMUNITIES 25 /* RFC5701 */
139 #define BGPTYPE_AIGP 26 /* RFC7311 */
140 #define BGPTYPE_PE_DISTINGUISHER_LABEL 27 /* RFC6514 */
141 #define BGPTYPE_ENTROPY_LABEL 28 /* RFC6790 */
142 #define BGPTYPE_LARGE_COMMUNITY 32 /* draft-ietf-idr-large-community-05 */
143 #define BGPTYPE_ATTR_SET 128 /* RFC6368 */
144
145 #define BGP_MP_NLRI_MINSIZE 3 /* End of RIB Marker detection */
146
147 static const struct tok bgp_attr_values[] = {
148 { BGPTYPE_ORIGIN, "Origin"},
149 { BGPTYPE_AS_PATH, "AS Path"},
150 { BGPTYPE_AS4_PATH, "AS4 Path"},
151 { BGPTYPE_NEXT_HOP, "Next Hop"},
152 { BGPTYPE_MULTI_EXIT_DISC, "Multi Exit Discriminator"},
153 { BGPTYPE_LOCAL_PREF, "Local Preference"},
154 { BGPTYPE_ATOMIC_AGGREGATE, "Atomic Aggregate"},
155 { BGPTYPE_AGGREGATOR, "Aggregator"},
156 { BGPTYPE_AGGREGATOR4, "Aggregator4"},
157 { BGPTYPE_COMMUNITIES, "Community"},
158 { BGPTYPE_ORIGINATOR_ID, "Originator ID"},
159 { BGPTYPE_CLUSTER_LIST, "Cluster List"},
160 { BGPTYPE_DPA, "DPA"},
161 { BGPTYPE_ADVERTISERS, "Advertisers"},
162 { BGPTYPE_RCID_PATH, "RCID Path / Cluster ID"},
163 { BGPTYPE_MP_REACH_NLRI, "Multi-Protocol Reach NLRI"},
164 { BGPTYPE_MP_UNREACH_NLRI, "Multi-Protocol Unreach NLRI"},
165 { BGPTYPE_EXTD_COMMUNITIES, "Extended Community"},
166 { BGPTYPE_PMSI_TUNNEL, "PMSI Tunnel"},
167 { BGPTYPE_TUNNEL_ENCAP, "Tunnel Encapsulation"},
168 { BGPTYPE_TRAFFIC_ENG, "Traffic Engineering"},
169 { BGPTYPE_IPV6_EXTD_COMMUNITIES, "IPv6 Extended Community"},
170 { BGPTYPE_AIGP, "Accumulated IGP Metric"},
171 { BGPTYPE_PE_DISTINGUISHER_LABEL, "PE Distinguisher Label"},
172 { BGPTYPE_ENTROPY_LABEL, "Entropy Label"},
173 { BGPTYPE_LARGE_COMMUNITY, "Large Community"},
174 { BGPTYPE_ATTR_SET, "Attribute Set"},
175 { 255, "Reserved for development"},
176 { 0, NULL}
177 };
178
179 #define BGP_AS_SET 1
180 #define BGP_AS_SEQUENCE 2
181 #define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */
182 #define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */
183
184 #define BGP_AS_SEG_TYPE_MIN BGP_AS_SET
185 #define BGP_AS_SEG_TYPE_MAX BGP_CONFED_AS_SET
186
187 static const struct tok bgp_as_path_segment_open_values[] = {
188 { BGP_AS_SEQUENCE, ""},
189 { BGP_AS_SET, "{ "},
190 { BGP_CONFED_AS_SEQUENCE, "( "},
191 { BGP_CONFED_AS_SET, "({ "},
192 { 0, NULL}
193 };
194
195 static const struct tok bgp_as_path_segment_close_values[] = {
196 { BGP_AS_SEQUENCE, ""},
197 { BGP_AS_SET, "}"},
198 { BGP_CONFED_AS_SEQUENCE, ")"},
199 { BGP_CONFED_AS_SET, "})"},
200 { 0, NULL}
201 };
202
203 #define BGP_OPT_AUTH 1
204 #define BGP_OPT_CAP 2
205
206 static const struct tok bgp_opt_values[] = {
207 { BGP_OPT_AUTH, "Authentication Information"},
208 { BGP_OPT_CAP, "Capabilities Advertisement"},
209 { 0, NULL}
210 };
211
212 #define BGP_CAPCODE_MP 1 /* RFC2858 */
213 #define BGP_CAPCODE_RR 2 /* RFC2918 */
214 #define BGP_CAPCODE_ORF 3 /* RFC5291 */
215 #define BGP_CAPCODE_MR 4 /* RFC3107 */
216 #define BGP_CAPCODE_EXT_NH 5 /* RFC5549 */
217 #define BGP_CAPCODE_ML 8 /* RFC8277 */
218 #define BGP_CAPCODE_RESTART 64 /* RFC4724 */
219 #define BGP_CAPCODE_AS_NEW 65 /* RFC6793 */
220 #define BGP_CAPCODE_DYN_CAP 67 /* draft-ietf-idr-dynamic-cap */
221 #define BGP_CAPCODE_MULTISESS 68 /* draft-ietf-idr-bgp-multisession */
222 #define BGP_CAPCODE_ADD_PATH 69 /* RFC7911 */
223 #define BGP_CAPCODE_ENH_RR 70 /* draft-keyur-bgp-enhanced-route-refresh */
224 #define BGP_CAPCODE_LLGR 71 /* draft-uttaro-idr-bgp-persistence-05 */
225 #define BGP_CAPCODE_RR_CISCO 128
226
227 static const struct tok bgp_capcode_values[] = {
228 { BGP_CAPCODE_MP, "Multiprotocol Extensions"},
229 { BGP_CAPCODE_RR, "Route Refresh"},
230 { BGP_CAPCODE_ORF, "Cooperative Route Filtering"},
231 { BGP_CAPCODE_MR, "Multiple Routes to a Destination"},
232 { BGP_CAPCODE_EXT_NH, "Extended Next Hop Encoding"},
233 { BGP_CAPCODE_ML, "Multiple Labels"},
234 { BGP_CAPCODE_RESTART, "Graceful Restart"},
235 { BGP_CAPCODE_AS_NEW, "32-Bit AS Number"},
236 { BGP_CAPCODE_DYN_CAP, "Dynamic Capability"},
237 { BGP_CAPCODE_MULTISESS, "Multisession BGP"},
238 { BGP_CAPCODE_ADD_PATH, "Multiple Paths"},
239 { BGP_CAPCODE_ENH_RR, "Enhanced Route Refresh"},
240 { BGP_CAPCODE_LLGR, "Long-lived Graceful Restart"},
241 { BGP_CAPCODE_RR_CISCO, "Route Refresh (Cisco)"},
242 { 0, NULL}
243 };
244
245 #define BGP_NOTIFY_MAJOR_MSG 1
246 #define BGP_NOTIFY_MAJOR_OPEN 2
247 #define BGP_NOTIFY_MAJOR_UPDATE 3
248 #define BGP_NOTIFY_MAJOR_HOLDTIME 4
249 #define BGP_NOTIFY_MAJOR_FSM 5
250 #define BGP_NOTIFY_MAJOR_CEASE 6
251 #define BGP_NOTIFY_MAJOR_CAP 7
252
253 static const struct tok bgp_notify_major_values[] = {
254 { BGP_NOTIFY_MAJOR_MSG, "Message Header Error"},
255 { BGP_NOTIFY_MAJOR_OPEN, "OPEN Message Error"},
256 { BGP_NOTIFY_MAJOR_UPDATE, "UPDATE Message Error"},
257 { BGP_NOTIFY_MAJOR_HOLDTIME,"Hold Timer Expired"},
258 { BGP_NOTIFY_MAJOR_FSM, "Finite State Machine Error"},
259 { BGP_NOTIFY_MAJOR_CEASE, "Cease"},
260 { BGP_NOTIFY_MAJOR_CAP, "Capability Message Error"},
261 { 0, NULL}
262 };
263
264 /* RFC 4486 */
265 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
266 #define BGP_NOTIFY_MINOR_CEASE_SHUT 2
267 #define BGP_NOTIFY_MINOR_CEASE_RESET 4
268 static const struct tok bgp_notify_minor_cease_values[] = {
269 { BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
270 { BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
271 { 3, "Peer Unconfigured"},
272 { BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
273 { 5, "Connection Rejected"},
274 { 6, "Other Configuration Change"},
275 { 7, "Connection Collision Resolution"},
276 { 0, NULL}
277 };
278
279 static const struct tok bgp_notify_minor_msg_values[] = {
280 { 1, "Connection Not Synchronized"},
281 { 2, "Bad Message Length"},
282 { 3, "Bad Message Type"},
283 { 0, NULL}
284 };
285
286 static const struct tok bgp_notify_minor_open_values[] = {
287 { 1, "Unsupported Version Number"},
288 { 2, "Bad Peer AS"},
289 { 3, "Bad BGP Identifier"},
290 { 4, "Unsupported Optional Parameter"},
291 { 5, "Authentication Failure"},
292 { 6, "Unacceptable Hold Time"},
293 { 7, "Capability Message Error"},
294 { 0, NULL}
295 };
296
297 static const struct tok bgp_notify_minor_update_values[] = {
298 { 1, "Malformed Attribute List"},
299 { 2, "Unrecognized Well-known Attribute"},
300 { 3, "Missing Well-known Attribute"},
301 { 4, "Attribute Flags Error"},
302 { 5, "Attribute Length Error"},
303 { 6, "Invalid ORIGIN Attribute"},
304 { 7, "AS Routing Loop"},
305 { 8, "Invalid NEXT_HOP Attribute"},
306 { 9, "Optional Attribute Error"},
307 { 10, "Invalid Network Field"},
308 { 11, "Malformed AS_PATH"},
309 { 0, NULL}
310 };
311
312 static const struct tok bgp_notify_minor_fsm_values[] = {
313 { 0, "Unspecified Error"},
314 { 1, "In OpenSent State"},
315 { 2, "In OpenConfirm State"},
316 { 3, "In Established State"},
317 { 0, NULL }
318 };
319
320 static const struct tok bgp_notify_minor_cap_values[] = {
321 { 1, "Invalid Action Value" },
322 { 2, "Invalid Capability Length" },
323 { 3, "Malformed Capability Value" },
324 { 4, "Unsupported Capability Code" },
325 { 0, NULL }
326 };
327
328 static const struct tok bgp_origin_values[] = {
329 { 0, "IGP"},
330 { 1, "EGP"},
331 { 2, "Incomplete"},
332 { 0, NULL}
333 };
334
335 #define BGP_PMSI_TUNNEL_RSVP_P2MP 1
336 #define BGP_PMSI_TUNNEL_LDP_P2MP 2
337 #define BGP_PMSI_TUNNEL_PIM_SSM 3
338 #define BGP_PMSI_TUNNEL_PIM_SM 4
339 #define BGP_PMSI_TUNNEL_PIM_BIDIR 5
340 #define BGP_PMSI_TUNNEL_INGRESS 6
341 #define BGP_PMSI_TUNNEL_LDP_MP2MP 7
342
343 static const struct tok bgp_pmsi_tunnel_values[] = {
344 { BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
345 { BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
346 { BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
347 { BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
348 { BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
349 { BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
350 { BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
351 { 0, NULL}
352 };
353
354 static const struct tok bgp_pmsi_flag_values[] = {
355 { 0x01, "Leaf Information required"},
356 { 0, NULL}
357 };
358
359 #define BGP_AIGP_TLV 1
360
361 static const struct tok bgp_aigp_values[] = {
362 { BGP_AIGP_TLV, "AIGP"},
363 { 0, NULL}
364 };
365
366 /* Subsequent address family identifier, RFC2283 section 7 */
367 #define SAFNUM_RES 0
368 #define SAFNUM_UNICAST 1
369 #define SAFNUM_MULTICAST 2
370 #define SAFNUM_UNIMULTICAST 3 /* deprecated now */
371 /* labeled BGP RFC3107 */
372 #define SAFNUM_LABUNICAST 4
373 /* RFC6514 */
374 #define SAFNUM_MULTICAST_VPN 5
375 /* draft-nalawade-kapoor-tunnel-safi */
376 #define SAFNUM_TUNNEL 64
377 /* RFC4761 */
378 #define SAFNUM_VPLS 65
379 /* RFC6037 */
380 #define SAFNUM_MDT 66
381 /* RFC7432 */
382 #define SAFNUM_EVPN 70
383 /* RFC4364 */
384 #define SAFNUM_VPNUNICAST 128
385 /* RFC6513 */
386 #define SAFNUM_VPNMULTICAST 129
387 #define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
388 /* RFC4684 */
389 #define SAFNUM_RT_ROUTING_INFO 132
390
391 #define BGP_VPN_RD_LEN 8
392
393 static const struct tok bgp_safi_values[] = {
394 { SAFNUM_RES, "Reserved"},
395 { SAFNUM_UNICAST, "Unicast"},
396 { SAFNUM_MULTICAST, "Multicast"},
397 { SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
398 { SAFNUM_LABUNICAST, "labeled Unicast"},
399 { SAFNUM_TUNNEL, "Tunnel"},
400 { SAFNUM_VPLS, "VPLS"},
401 { SAFNUM_MDT, "MDT"},
402 { SAFNUM_EVPN, "EVPN"},
403 { SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
404 { SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
405 { SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
406 { SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
407 { SAFNUM_MULTICAST_VPN, "Multicast VPN"},
408 { 0, NULL }
409 };
410
411 /* well-known community */
412 #define BGP_COMMUNITY_NO_EXPORT 0xffffff01
413 #define BGP_COMMUNITY_NO_ADVERT 0xffffff02
414 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
415
416 /* Extended community type - RFC 4360 */
417 #define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
418 #define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
419 #define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
420 #define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
421 #define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
422 #define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
423 #define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
424 /* rfc2547 bgp-mpls-vpns */
425 #define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
426 #define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
427 #define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
428 #define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
429
430 #define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
431 #define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
432 #define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
433
434 #define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
435 #define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
436
437 #define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
438
439 #define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
440 #define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
441 #define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
442 #define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
443
444 /* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
445 #define BGP_EXT_COM_EIGRP_GEN 0x8800
446 #define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
447 #define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
448 #define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
449 #define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
450 #define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
451
452 static const struct tok bgp_extd_comm_flag_values[] = {
453 { 0x8000, "vendor-specific"},
454 { 0x4000, "non-transitive"},
455 { 0, NULL},
456 };
457
458 static const struct tok bgp_extd_comm_subtype_values[] = {
459 { BGP_EXT_COM_RT_0, "target"},
460 { BGP_EXT_COM_RT_1, "target"},
461 { BGP_EXT_COM_RT_2, "target"},
462 { BGP_EXT_COM_RO_0, "origin"},
463 { BGP_EXT_COM_RO_1, "origin"},
464 { BGP_EXT_COM_RO_2, "origin"},
465 { BGP_EXT_COM_LINKBAND, "link-BW"},
466 { BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
467 { BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
468 { BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
469 { BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
470 { BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
471 { BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
472 { BGP_EXT_COM_ENCAP, "encapsulation"},
473 { BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
474 { BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
475 { BGP_EXT_COM_L2INFO, "layer2-info"},
476 { BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
477 { BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
478 { BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
479 { BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
480 { BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
481 { BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
482 { BGP_EXT_COM_SOURCE_AS, "source-AS" },
483 { BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
484 { BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
485 { BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
486 { 0, NULL},
487 };
488
489 /* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
490 #define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
491 #define BGP_ENCAP_TUNNEL_GRE 2
492 #define BGP_ENCAP_TUNNEL_TRANSMIT 3
493 #define BGP_ENCAP_TUNNEL_IPSEC 4
494 #define BGP_ENCAP_TUNNEL_IP_IPSEC 5
495 #define BGP_ENCAP_TUNNEL_MPLS_IP 6
496 #define BGP_ENCAP_TUNNEL_IP_IP 7
497 #define BGP_ENCAP_TUNNEL_VXLAN 8
498 #define BGP_ENCAP_TUNNEL_NVGRE 9
499 #define BGP_ENCAP_TUNNEL_MPLS 10
500 #define BGP_ENCAP_TUNNEL_MPLS_GRE 11
501 #define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
502 #define BGP_ENCAP_TUNNEL_MPLS_UDP 13
503 #define BGP_ENCAP_TUNNEL_IPV6 14
504 #define BGP_ENCAP_TUNNEL_SR_TE 15
505 #define BGP_ENCAP_TUNNEL_BARE 16
506 #define BGP_ENCAP_TUNNEL_SR 17
507
508 static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
509 { BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
510 { BGP_ENCAP_TUNNEL_GRE, "GRE"},
511 { BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
512 { BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
513 { BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
514 { BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
515 { BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
516 { BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
517 { BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
518 { BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
519 { BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
520 { BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
521 { BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
522 { BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
523 { BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
524 { BGP_ENCAP_TUNNEL_BARE, "Bare"},
525 { BGP_ENCAP_TUNNEL_SR, "SR"},
526 { 0, NULL},
527 };
528
529 /* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
530 #define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
531 #define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
532 #define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
533 #define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
534 #define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
535 #define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
536 #define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
537
538 static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
539 { BGP_OSPF_RTYPE_RTR, "Router" },
540 { BGP_OSPF_RTYPE_NET, "Network" },
541 { BGP_OSPF_RTYPE_SUM, "Summary" },
542 { BGP_OSPF_RTYPE_EXT, "External" },
543 { BGP_OSPF_RTYPE_NSSA,"NSSA External" },
544 { BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
545 { 0, NULL },
546 };
547
548 /* ADD-PATH Send/Receive field values */
549 static const struct tok bgp_add_path_recvsend[] = {
550 { 1, "Receive" },
551 { 2, "Send" },
552 { 3, "Both" },
553 { 0, NULL },
554 };
555
556 #define AS_STR_SIZE sizeof("xxxxx.xxxxx")
557
558 /*
559 * as_printf
560 *
561 * Convert an AS number into a string and return string pointer.
562 *
563 * Depending on bflag is set or not, AS number is converted into ASDOT notation
564 * or plain number notation.
565 *
566 */
567 static char *
568 as_printf(netdissect_options *ndo,
569 char *str, size_t size, u_int asnum)
570 {
571 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
572 snprintf(str, size, "%u", asnum);
573 } else {
574 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
575 }
576 return str;
577 }
578
579 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
580
581 int
582 decode_prefix4(netdissect_options *ndo,
583 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
584 {
585 nd_ipv4 addr;
586 u_int plen, plenbytes;
587
588 ITEMCHECK(1);
589 plen = GET_U_1(pptr);
590 if (32 < plen)
591 return -1;
592 itemlen -= 1;
593
594 memset(&addr, 0, sizeof(addr));
595 plenbytes = (plen + 7) / 8;
596 ITEMCHECK(plenbytes);
597 GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
598 if (plen % 8) {
599 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
600 }
601 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
602 return 1 + plenbytes;
603
604 badtlv:
605 return -2;
606 }
607
608 static int
609 decode_labeled_prefix4(netdissect_options *ndo,
610 const u_char *pptr, u_int itemlen, char *buf,
611 size_t buflen)
612 {
613 nd_ipv4 addr;
614 u_int plen, plenbytes;
615
616 /* prefix length and label = 4 bytes */
617 ND_TCHECK_4(pptr);
618 ITEMCHECK(4);
619 plen = GET_U_1(pptr); /* get prefix length */
620
621 /* this is one of the weirdnesses of rfc3107
622 the label length (actually the label + COS bits)
623 is added to the prefix length;
624 we also do only read out just one label -
625 there is no real application for advertisement of
626 stacked labels in a single BGP message
627 */
628
629 if (24 > plen)
630 return -1;
631
632 plen-=24; /* adjust prefixlen - labellength */
633
634 if (32 < plen)
635 return -1;
636 itemlen -= 4;
637
638 memset(&addr, 0, sizeof(addr));
639 plenbytes = (plen + 7) / 8;
640 ITEMCHECK(plenbytes);
641 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
642 if (plen % 8) {
643 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
644 }
645 /* the label may get offsetted by 4 bits so lets shift it right */
646 snprintf(buf, buflen, "%s/%u, label:%u %s",
647 ipaddr_string(ndo, (const u_char *)&addr),
648 plen,
649 GET_BE_U_3(pptr + 1)>>4,
650 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
651
652 return 4 + plenbytes;
653
654 trunc:
655 return -2;
656
657 badtlv:
658 return -3;
659 }
660
661 /*
662 * bgp_vpn_ip_print
663 *
664 * print an ipv4 or ipv6 address into a buffer dependent on address length.
665 */
666 static char *
667 bgp_vpn_ip_print(netdissect_options *ndo,
668 const u_char *pptr, u_int addr_length)
669 {
670
671 /* worst case string is s fully formatted v6 address */
672 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
673 char *pos = addr;
674
675 switch(addr_length) {
676 case (sizeof(nd_ipv4) << 3): /* 32 */
677 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
678 break;
679 case (sizeof(nd_ipv6) << 3): /* 128 */
680 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
681 break;
682 default:
683 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
684 break;
685 }
686 pos += strlen(pos);
687
688 *(pos) = '\0';
689 return (addr);
690 }
691
692 /*
693 * bgp_vpn_sg_print
694 *
695 * print an multicast s,g entry into a buffer.
696 * the s,g entry is encoded like this.
697 *
698 * +-----------------------------------+
699 * | Multicast Source Length (1 octet) |
700 * +-----------------------------------+
701 * | Multicast Source (Variable) |
702 * +-----------------------------------+
703 * | Multicast Group Length (1 octet) |
704 * +-----------------------------------+
705 * | Multicast Group (Variable) |
706 * +-----------------------------------+
707 *
708 * return the number of bytes read from the wire.
709 */
710 static u_int
711 bgp_vpn_sg_print(netdissect_options *ndo,
712 const u_char *pptr, char *buf, size_t buflen)
713 {
714 uint8_t addr_length;
715 u_int total_length, offset;
716
717 total_length = 0;
718
719 /* Source address length, encoded in bits */
720 addr_length = GET_U_1(pptr);
721 pptr++;
722
723 /* Source address */
724 ND_TCHECK_LEN(pptr, (addr_length >> 3));
725 total_length += (addr_length >> 3) + 1;
726 offset = (u_int)strlen(buf);
727 if (addr_length) {
728 snprintf(buf + offset, buflen - offset, ", Source %s",
729 bgp_vpn_ip_print(ndo, pptr, addr_length));
730 pptr += (addr_length >> 3);
731 }
732
733 /* Group address length, encoded in bits */
734 addr_length = GET_U_1(pptr);
735 pptr++;
736
737 /* Group address */
738 ND_TCHECK_LEN(pptr, (addr_length >> 3));
739 total_length += (addr_length >> 3) + 1;
740 offset = (u_int)strlen(buf);
741 if (addr_length) {
742 snprintf(buf + offset, buflen - offset, ", Group %s",
743 bgp_vpn_ip_print(ndo, pptr, addr_length));
744 pptr += (addr_length >> 3);
745 }
746
747 trunc:
748 return (total_length);
749 }
750
751 /* Print an RFC 4364 Route Distinguisher */
752 const char *
753 bgp_vpn_rd_print(netdissect_options *ndo,
754 const u_char *pptr)
755 {
756 /* allocate space for the largest possible string */
757 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
758 char *pos = rd;
759 /* allocate space for the largest possible string */
760 char astostr[AS_STR_SIZE];
761
762 /* ok lets load the RD format */
763 switch (GET_BE_U_2(pptr)) {
764
765 case 0:
766 /* 2-byte-AS:number fmt */
767 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
768 GET_BE_U_2(pptr + 2),
769 GET_BE_U_4(pptr + 4),
770 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
771 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
772 break;
773
774 case 1:
775 /* IP-address:AS fmt */
776 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
777 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
778 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
779 GET_BE_U_2(pptr + 6));
780 break;
781
782 case 2:
783 /* 4-byte-AS:number fmt */
784 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
785 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
786 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
787 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
788 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
789 break;
790 default:
791 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
792 break;
793 }
794 pos += strlen(pos);
795 *(pos) = '\0';
796 return (rd);
797 }
798
799 /*
800 * Print an RFC 4360 Extended Community.
801 */
802 static void
803 bgp_extended_community_print(netdissect_options *ndo,
804 const u_char *pptr)
805 {
806 union { /* copy buffer for bandwidth values */
807 float f;
808 uint32_t i;
809 } bw;
810 /* allocate space for the largest possible string */
811 char astostr[AS_STR_SIZE];
812
813 switch (GET_BE_U_2(pptr)) {
814
815 case BGP_EXT_COM_RT_0:
816 case BGP_EXT_COM_RO_0:
817 case BGP_EXT_COM_L2VPN_RT_0:
818 ND_PRINT("%u:%u (= %s)",
819 GET_BE_U_2(pptr + 2),
820 GET_BE_U_4(pptr + 4),
821 GET_IPADDR_STRING(pptr+4));
822 break;
823
824 case BGP_EXT_COM_RT_1:
825 case BGP_EXT_COM_RO_1:
826 case BGP_EXT_COM_L2VPN_RT_1:
827 case BGP_EXT_COM_VRF_RT_IMP:
828 ND_PRINT("%s:%u",
829 GET_IPADDR_STRING(pptr+2),
830 GET_BE_U_2(pptr + 6));
831 break;
832
833 case BGP_EXT_COM_RT_2:
834 case BGP_EXT_COM_RO_2:
835 ND_PRINT("%s:%u",
836 as_printf(ndo, astostr, sizeof(astostr),
837 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
838 break;
839
840 case BGP_EXT_COM_LINKBAND:
841 bw.i = GET_BE_U_4(pptr + 4);
842 ND_PRINT("bandwidth: %.3f Mbps",
843 bw.f*8/1000000);
844 break;
845
846 case BGP_EXT_COM_VPN_ORIGIN:
847 case BGP_EXT_COM_VPN_ORIGIN2:
848 case BGP_EXT_COM_VPN_ORIGIN3:
849 case BGP_EXT_COM_VPN_ORIGIN4:
850 case BGP_EXT_COM_OSPF_RID:
851 case BGP_EXT_COM_OSPF_RID2:
852 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
853 break;
854
855 case BGP_EXT_COM_OSPF_RTYPE:
856 case BGP_EXT_COM_OSPF_RTYPE2:
857 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
858 GET_IPADDR_STRING(pptr+2),
859 tok2str(bgp_extd_comm_ospf_rtype_values,
860 "unknown (0x%02x)",
861 GET_U_1((pptr + 6))),
862 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
863 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
864 break;
865
866 case BGP_EXT_COM_L2INFO:
867 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
868 tok2str(l2vpn_encaps_values,
869 "unknown encaps",
870 GET_U_1((pptr + 2))),
871 GET_U_1((pptr + 3)),
872 GET_BE_U_2(pptr + 4));
873 break;
874
875 case BGP_EXT_COM_SOURCE_AS:
876 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
877 break;
878
879 case BGP_EXT_COM_ENCAP:
880 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
881 "unknown encaps",
882 GET_BE_U_2(pptr + 6)));
883 break;
884
885 default:
886 ND_PRINT("%02x%02x%02x%02x%02x%02x",
887 GET_U_1(pptr + 2),
888 GET_U_1(pptr + 3),
889 GET_U_1(pptr + 4),
890 GET_U_1(pptr + 5),
891 GET_U_1(pptr + 6),
892 GET_U_1(pptr + 7));
893 break;
894 }
895 }
896
897 /*
898 * RFC4684 (Section 4)/RFC2858 (Section 4).
899 * RTC membership prefix is structured as follows
900 * [prefix-len] [origin-as] [route-target]
901 * The route-target is encoded as RT ext-comms.
902 * Prefix-len may be 0, 32..96
903 *
904 * Note that pptr is not packet data - it is
905 * a buffer owned by our caller - therefore GET_*
906 * macros can not be used.
907 */
908 static char *
909 bgp_rt_prefix_print(netdissect_options *ndo,
910 const u_char *pptr,
911 u_int plen)
912 {
913 /* allocate space for the largest possible string */
914 char rtc_prefix_in_hex[sizeof("0000 0000 0000 0000")] = "";
915 u_int rtc_prefix_in_hex_len = 0;
916 static char output[61]; /* max response string */
917 /* allocate space for the largest possible string */
918 char astostr[AS_STR_SIZE];
919 uint16_t ec_type = 0;
920 u_int octet_count;
921 u_int i;
922
923 if (plen == 0) {
924 snprintf(output, sizeof(output), "route-target: 0:0/0");
925 return (output);
926 }
927
928 /* hex representation of the prefix */
929 octet_count = (plen+7)/8;
930 for (i=0; i<octet_count; i++) {
931 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
932 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
933 "%02x%s", *(pptr+i),
934 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
935 }
936
937 if (plen < 16) {
938 /*
939 * The prefix is too short to include the full ext-comm type,
940 * so we have no way to parse it further.
941 */
942 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
943 rtc_prefix_in_hex, plen);
944 return (output);
945 }
946
947 /*
948 * get the ext-comm type
949 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
950 * hence EXTRACT_*() macros are safe.
951 */
952 ec_type = EXTRACT_BE_U_2(pptr);
953 switch (ec_type) {
954 case BGP_EXT_COM_RT_0:
955 /* 2-byte-AS:number fmt */
956 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
957 EXTRACT_BE_U_2(pptr+2),
958 EXTRACT_BE_U_4(pptr+4),
959 plen, rtc_prefix_in_hex);
960 break;
961
962 case BGP_EXT_COM_RT_1:
963 /* IP-address:AS fmt */
964 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
965 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
966 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
967 break;
968
969 case BGP_EXT_COM_RT_2:
970 /* 4-byte-AS:number fmt */
971 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
972 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
973 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
974 break;
975
976 default:
977 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
978 ec_type,
979 rtc_prefix_in_hex, plen);
980 break;
981 }
982 return (output);
983 }
984
985 /* RFC 4684 */
986 static int
987 decode_rt_routing_info(netdissect_options *ndo,
988 const u_char *pptr)
989 {
990 uint8_t route_target[8];
991 u_int plen;
992 /* allocate space for the largest possible string */
993 char astostr[AS_STR_SIZE];
994 u_int num_octets;
995
996 /* NLRI "prefix length" from RFC 2858 Section 4. */
997 plen = GET_U_1(pptr); /* get prefix length */
998
999 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1000 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1001 * target" fields inside the "prefix" depending on its length.
1002 */
1003 if (0 == plen) {
1004 /* Without "origin AS", without "route target". */
1005 ND_PRINT("\n\t default route target");
1006 return 1;
1007 }
1008
1009 if (32 > plen) {
1010 ND_PRINT("\n\t (illegal prefix length)");
1011 return -1;
1012 }
1013
1014 /* With at least "origin AS", possibly with "route target". */
1015 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
1016
1017 plen -= 32; /* adjust prefix length */
1018
1019 if (64 < plen) {
1020 ND_PRINT("\n\t (illegal prefix length)");
1021 return -1;
1022 }
1023
1024 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1025 * and gives the number of octets in the variable-length "route
1026 * target" field inside this NLRI "prefix". Look for it.
1027 */
1028 memset(&route_target, 0, sizeof(route_target));
1029 num_octets = (plen + 7) / 8;
1030 GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
1031 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1032 if (plen % 8) {
1033 ((u_char *)&route_target)[num_octets - 1] &=
1034 ((0xff00 >> (plen % 8)) & 0xff);
1035 }
1036 ND_PRINT("\n\t origin AS: %s, %s",
1037 astostr,
1038 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1039
1040 return 5 + num_octets;
1041 }
1042
1043 static int
1044 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1045 const u_char *pptr, char *buf, size_t buflen)
1046 {
1047 nd_ipv4 addr;
1048 u_int plen;
1049
1050 plen = GET_U_1(pptr); /* get prefix length */
1051
1052 if ((24+64) > plen)
1053 return -1;
1054
1055 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1056
1057 if (32 < plen)
1058 return -1;
1059
1060 memset(&addr, 0, sizeof(addr));
1061 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1062 if (plen % 8) {
1063 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1064 ((0xff00 >> (plen % 8)) & 0xff);
1065 }
1066 /* the label may get offsetted by 4 bits so lets shift it right */
1067 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1068 bgp_vpn_rd_print(ndo, pptr+4),
1069 ipaddr_string(ndo, (const u_char *)&addr),
1070 plen,
1071 GET_BE_U_3(pptr + 1)>>4,
1072 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1073
1074 return 12 + (plen + 7) / 8;
1075 }
1076
1077 /*
1078 * +-------------------------------+
1079 * | |
1080 * | RD:IPv4-address (12 octets) |
1081 * | |
1082 * +-------------------------------+
1083 * | MDT Group-address (4 octets) |
1084 * +-------------------------------+
1085 */
1086
1087 #define MDT_VPN_NLRI_LEN 16
1088
1089 static int
1090 decode_mdt_vpn_nlri(netdissect_options *ndo,
1091 const u_char *pptr, char *buf, size_t buflen)
1092 {
1093 const u_char *rd;
1094 const u_char *vpn_ip;
1095
1096 /* if the NLRI is not predefined length, quit.*/
1097 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1098 return -1;
1099 pptr++;
1100
1101 /* RD */
1102 ND_TCHECK_8(pptr);
1103 rd = pptr;
1104 pptr += 8;
1105
1106 /* IPv4 address */
1107 vpn_ip = pptr;
1108 pptr += sizeof(nd_ipv4);
1109
1110 /* MDT Group Address */
1111 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1112 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1113
1114 return MDT_VPN_NLRI_LEN + 1;
1115
1116 trunc:
1117 return -2;
1118 }
1119
1120 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1121 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1122 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1123 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1124 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1125 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1126 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1127
1128 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1129 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1130 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1131 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1132 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1133 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1134 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1135 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1136 { 0, NULL}
1137 };
1138
1139 static int
1140 decode_multicast_vpn(netdissect_options *ndo,
1141 const u_char *pptr, char *buf, size_t buflen)
1142 {
1143 /* allocate space for the largest possible string */
1144 char astostr[AS_STR_SIZE];
1145 uint8_t route_type, route_length;
1146 u_int addr_length, sg_length;
1147 u_int offset;
1148
1149 route_type = GET_U_1(pptr);
1150 pptr++;
1151 route_length = GET_U_1(pptr);
1152 pptr++;
1153
1154 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1155 tok2str(bgp_multicast_vpn_route_type_values,
1156 "Unknown", route_type),
1157 route_type, route_length);
1158
1159 switch(route_type) {
1160 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1161 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1162 if (route_length < BGP_VPN_RD_LEN)
1163 goto trunc;
1164 offset = (u_int)strlen(buf);
1165 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1166 bgp_vpn_rd_print(ndo, pptr),
1167 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1168 (route_length - BGP_VPN_RD_LEN) << 3));
1169 break;
1170 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1171 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1172 offset = (u_int)strlen(buf);
1173 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1174 bgp_vpn_rd_print(ndo, pptr),
1175 as_printf(ndo, astostr, sizeof(astostr),
1176 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1177 break;
1178
1179 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1180 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1181 offset = (u_int)strlen(buf);
1182 snprintf(buf + offset, buflen - offset, ", RD: %s",
1183 bgp_vpn_rd_print(ndo, pptr));
1184 pptr += BGP_VPN_RD_LEN;
1185
1186 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1187 addr_length = route_length - sg_length;
1188
1189 ND_TCHECK_LEN(pptr, addr_length);
1190 offset = (u_int)strlen(buf);
1191 snprintf(buf + offset, buflen - offset, ", Originator %s",
1192 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1193 break;
1194
1195 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1196 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1197 offset = (u_int)strlen(buf);
1198 snprintf(buf + offset, buflen - offset, ", RD: %s",
1199 bgp_vpn_rd_print(ndo, pptr));
1200 pptr += BGP_VPN_RD_LEN;
1201
1202 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1203 break;
1204
1205 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1206 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1207 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1208 offset = (u_int)strlen(buf);
1209 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1210 bgp_vpn_rd_print(ndo, pptr),
1211 as_printf(ndo, astostr, sizeof(astostr),
1212 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1213 pptr += BGP_VPN_RD_LEN + 4;
1214
1215 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1216 break;
1217
1218 /*
1219 * no per route-type printing yet.
1220 */
1221 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1222 default:
1223 break;
1224 }
1225
1226 return route_length + 2;
1227
1228 trunc:
1229 return -2;
1230 }
1231
1232 /*
1233 * As I remember, some versions of systems have an snprintf() that
1234 * returns -1 if the buffer would have overflowed. If the return
1235 * value is negative, set buflen to 0, to indicate that we've filled
1236 * the buffer up.
1237 *
1238 * If the return value is greater than buflen, that means that
1239 * the buffer would have overflowed; again, set buflen to 0 in
1240 * that case.
1241 */
1242 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1243 if (stringlen<0) \
1244 buflen=0; \
1245 else if ((u_int)stringlen>buflen) \
1246 buflen=0; \
1247 else { \
1248 buflen-=stringlen; \
1249 buf+=stringlen; \
1250 }
1251
1252 static int
1253 decode_labeled_vpn_l2(netdissect_options *ndo,
1254 const u_char *pptr, char *buf, size_t buflen)
1255 {
1256 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1257 int stringlen;
1258
1259 plen = GET_BE_U_2(pptr);
1260 tlen = plen;
1261 pptr += 2;
1262 /* Old and new L2VPN NLRI share AFI/SAFI
1263 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1264 * and > 17 as old format. Complain for the middle case
1265 */
1266 if (plen == 12) {
1267 /* assume AD-only with RD, BGPNH */
1268 ND_TCHECK_LEN(pptr, 12);
1269 buf[0] = '\0';
1270 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1271 bgp_vpn_rd_print(ndo, pptr),
1272 GET_IPADDR_STRING(pptr+8));
1273 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1274 pptr += 12;
1275 tlen -= 12;
1276 return plen + 2;
1277 } else if (plen > 17) {
1278 /* assume old format */
1279 /* RD, ID, LBLKOFF, LBLBASE */
1280
1281 ND_TCHECK_LEN(pptr, 15);
1282 buf[0] = '\0';
1283 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1284 bgp_vpn_rd_print(ndo, pptr),
1285 GET_BE_U_2(pptr + 8),
1286 GET_BE_U_2(pptr + 10),
1287 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1288 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1289 pptr += 15;
1290 tlen -= 15;
1291
1292 /* ok now the variable part - lets read out TLVs*/
1293 while (tlen != 0) {
1294 if (tlen < 3) {
1295 if (buflen != 0) {
1296 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1297 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1298 }
1299 return plen + 2;
1300 }
1301 tlv_type = GET_U_1(pptr);
1302 pptr++;
1303 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1304 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1305 pptr += 2;
1306
1307 switch(tlv_type) {
1308 case 1:
1309 if (buflen != 0) {
1310 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1311 tlv_type,
1312 tlv_len);
1313 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1314 }
1315 while (ttlv_len != 0) {
1316 if (tlen < 1) {
1317 if (buflen != 0) {
1318 stringlen=snprintf(buf,buflen, " (ran past the end)");
1319 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1320 }
1321 return plen + 2;
1322 }
1323 ND_TCHECK_1(pptr);
1324 if (buflen != 0) {
1325 stringlen=snprintf(buf,buflen, "%02x",
1326 GET_U_1(pptr));
1327 pptr++;
1328 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1329 }
1330 ttlv_len--;
1331 tlen--;
1332 }
1333 break;
1334 default:
1335 if (buflen != 0) {
1336 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1337 tlv_type,
1338 tlv_len);
1339 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1340 }
1341 if (tlen < ttlv_len) {
1342 if (buflen != 0) {
1343 stringlen=snprintf(buf,buflen, " (ran past the end)");
1344 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1345 }
1346 return plen + 2;
1347 }
1348 tlen -= ttlv_len;
1349 break;
1350 }
1351 }
1352 return plen + 2;
1353 } else {
1354 /* complain bitterly ? */
1355 /* fall through */
1356 goto trunc;
1357 }
1358
1359 trunc:
1360 return -2;
1361 }
1362
1363 int
1364 decode_prefix6(netdissect_options *ndo,
1365 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1366 {
1367 nd_ipv6 addr;
1368 u_int plen, plenbytes;
1369
1370 ITEMCHECK(1);
1371 plen = GET_U_1(pd);
1372 if (128 < plen)
1373 return -1;
1374 itemlen -= 1;
1375
1376 memset(&addr, 0, sizeof(addr));
1377 plenbytes = (plen + 7) / 8;
1378 ITEMCHECK(plenbytes);
1379 GET_CPY_BYTES(&addr, pd + 1, plenbytes);
1380 if (plen % 8) {
1381 addr[plenbytes - 1] &=
1382 ((0xff00 >> (plen % 8)) & 0xff);
1383 }
1384 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1385 return 1 + plenbytes;
1386
1387 badtlv:
1388 return -2;
1389 }
1390
1391 static int
1392 decode_labeled_prefix6(netdissect_options *ndo,
1393 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1394 {
1395 nd_ipv6 addr;
1396 u_int plen, plenbytes;
1397
1398 /* prefix length and label = 4 bytes */
1399 ND_TCHECK_4(pptr);
1400 ITEMCHECK(4);
1401 plen = GET_U_1(pptr); /* get prefix length */
1402
1403 if (24 > plen)
1404 return -1;
1405
1406 plen -= 24; /* adjust prefixlen - labellength */
1407
1408 if (128 < plen)
1409 return -1;
1410 itemlen -= 4;
1411
1412 memset(&addr, 0, sizeof(addr));
1413 plenbytes = (plen + 7) / 8;
1414 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
1415 if (plen % 8) {
1416 addr[plenbytes - 1] &=
1417 ((0xff00 >> (plen % 8)) & 0xff);
1418 }
1419 /* the label may get offsetted by 4 bits so lets shift it right */
1420 snprintf(buf, buflen, "%s/%u, label:%u %s",
1421 ip6addr_string(ndo, (const u_char *)&addr),
1422 plen,
1423 GET_BE_U_3(pptr + 1)>>4,
1424 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1425
1426 return 4 + plenbytes;
1427
1428 trunc:
1429 return -2;
1430
1431 badtlv:
1432 return -3;
1433 }
1434
1435 static int
1436 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1437 const u_char *pptr, char *buf, size_t buflen)
1438 {
1439 nd_ipv6 addr;
1440 u_int plen;
1441
1442 plen = GET_U_1(pptr); /* get prefix length */
1443
1444 if ((24+64) > plen)
1445 return -1;
1446
1447 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1448
1449 if (128 < plen)
1450 return -1;
1451
1452 memset(&addr, 0, sizeof(addr));
1453 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1454 if (plen % 8) {
1455 addr[(plen + 7) / 8 - 1] &=
1456 ((0xff00 >> (plen % 8)) & 0xff);
1457 }
1458 /* the label may get offsetted by 4 bits so lets shift it right */
1459 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1460 bgp_vpn_rd_print(ndo, pptr+4),
1461 ip6addr_string(ndo, (const u_char *)&addr),
1462 plen,
1463 GET_BE_U_3(pptr + 1)>>4,
1464 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1465
1466 return 12 + (plen + 7) / 8;
1467 }
1468
1469 static int
1470 decode_clnp_prefix(netdissect_options *ndo,
1471 const u_char *pptr, char *buf, size_t buflen)
1472 {
1473 uint8_t addr[19];
1474 u_int plen;
1475
1476 plen = GET_U_1(pptr); /* get prefix length */
1477
1478 if (152 < plen)
1479 return -1;
1480
1481 memset(&addr, 0, sizeof(addr));
1482 GET_CPY_BYTES(&addr, pptr + 4, (plen + 7) / 8);
1483 if (plen % 8) {
1484 addr[(plen + 7) / 8 - 1] &=
1485 ((0xff00 >> (plen % 8)) & 0xff);
1486 }
1487 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1488 snprintf(buf, buflen, "%s/%u",
1489 isonsap_string(ndo, addr,(plen + 7) / 8),
1490 plen);
1491
1492 return 1 + (plen + 7) / 8;
1493 }
1494
1495 static int
1496 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1497 const u_char *pptr, char *buf, size_t buflen)
1498 {
1499 uint8_t addr[19];
1500 u_int plen;
1501
1502 plen = GET_U_1(pptr); /* get prefix length */
1503
1504 if ((24+64) > plen)
1505 return -1;
1506
1507 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1508
1509 if (152 < plen)
1510 return -1;
1511
1512 memset(&addr, 0, sizeof(addr));
1513 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1514 if (plen % 8) {
1515 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1516 }
1517 /* the label may get offsetted by 4 bits so lets shift it right */
1518 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1519 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1520 bgp_vpn_rd_print(ndo, pptr+4),
1521 isonsap_string(ndo, addr,(plen + 7) / 8),
1522 plen,
1523 GET_BE_U_3(pptr + 1)>>4,
1524 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1525
1526 return 12 + (plen + 7) / 8;
1527 }
1528
1529 /*
1530 * bgp_attr_get_as_size
1531 *
1532 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1533 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1534 * support, exchange AS-Path with the same path-attribute type value 0x02.
1535 */
1536 static u_int
1537 bgp_attr_get_as_size(netdissect_options *ndo,
1538 uint8_t bgpa_type, const u_char *pptr, u_int len)
1539 {
1540 const u_char *tptr = pptr;
1541
1542 /*
1543 * If the path attribute is the optional AS4 path type, then we already
1544 * know, that ASs must be encoded in 4 byte format.
1545 */
1546 if (bgpa_type == BGPTYPE_AS4_PATH) {
1547 return 4;
1548 }
1549
1550 /*
1551 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1552 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1553 * each.
1554 */
1555 while (tptr < pptr + len) {
1556 /*
1557 * If we do not find a valid segment type, our guess might be wrong.
1558 */
1559 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1560 goto trunc;
1561 }
1562 tptr += 2 + GET_U_1(tptr + 1) * 2;
1563 }
1564
1565 /*
1566 * If we correctly reached end of the AS path attribute data content,
1567 * then most likely ASs were indeed encoded as 2 bytes.
1568 */
1569 if (tptr == pptr + len) {
1570 return 2;
1571 }
1572
1573 trunc:
1574
1575 /*
1576 * We can come here, either we did not have enough data, or if we
1577 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1578 * so that caller can try to decode each AS as of 4 bytes. If indeed
1579 * there was not enough data, it will crib and end the parse anyways.
1580 */
1581 return 4;
1582 }
1583
1584 /*
1585 * The only way to know that a BGP UPDATE message is using add path is
1586 * by checking if the capability is in the OPEN message which we may have missed.
1587 * So this function checks if it is possible that the update could contain add path
1588 * and if so it checks that standard BGP doesn't make sense.
1589 */
1590 static int
1591 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1592 u_int max_prefix_length)
1593 {
1594 u_int offset, prefix_length;
1595
1596 if (length < 5) {
1597 return 0;
1598 }
1599
1600 /*
1601 * Scan through the NLRI information under the assumption that
1602 * it doesn't have path IDs.
1603 */
1604 for (offset = 0; offset < length;) {
1605 offset += 4;
1606 if (!ND_TTEST_1(pptr + offset)) {
1607 /* We ran out of captured data; quit scanning. */
1608 break;
1609 }
1610 prefix_length = GET_U_1(pptr + offset);
1611 /*
1612 * Add 4 to cover the path id
1613 * and check the prefix length isn't greater than 32/128.
1614 */
1615 if (prefix_length > max_prefix_length) {
1616 return 0;
1617 }
1618 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1619 offset += 1 + ((prefix_length + 7) / 8);
1620 }
1621 /* check we haven't gone past the end of the section */
1622 if (offset > length) {
1623 return 0;
1624 }
1625
1626 /* check it's not standard BGP */
1627 for (offset = 0; offset < length; ) {
1628 if (!ND_TTEST_1(pptr + offset)) {
1629 /* We ran out of captured data; quit scanning. */
1630 break;
1631 }
1632 prefix_length = GET_U_1(pptr + offset);
1633 /*
1634 * If the prefix_length is zero (0.0.0.0/0)
1635 * and since it's not the only address (length >= 5)
1636 * then it is add-path
1637 */
1638 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1639 return 1;
1640 }
1641 offset += 1 + ((prefix_length + 7) / 8);
1642 }
1643 if (offset > length) {
1644 return 1;
1645 }
1646
1647 /* assume not add-path by default */
1648 return 0;
1649 }
1650
1651 static int
1652 bgp_mp_af_print(netdissect_options *ndo,
1653 const u_char *tptr, u_int tlen,
1654 uint16_t *afp, uint8_t *safip)
1655 {
1656 uint16_t af;
1657 uint8_t safi;
1658
1659 af = GET_BE_U_2(tptr);
1660 *afp = af;
1661 safi = GET_U_1(tptr + 2);
1662 *safip = safi;
1663
1664 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1665 tok2str(af_values, "Unknown AFI", af),
1666 af,
1667 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1668 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1669 safi);
1670
1671 switch(af<<8 | safi) {
1672 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1673 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1674 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1675 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1676 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1677 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1678 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1679 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1680 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1681 case (AFNUM_INET<<8 | SAFNUM_MDT):
1682 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1683 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1684 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1685 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1686 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1687 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1688 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1689 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1690 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1691 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1692 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1693 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1694 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1695 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1696 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1697 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1698 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1699 break;
1700 default:
1701 ND_TCHECK_LEN(tptr, tlen);
1702 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1703 if (ndo->ndo_vflag <= 1)
1704 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1705 return -1;
1706 }
1707 return 0;
1708 trunc:
1709 return -2;
1710 }
1711
1712 static int
1713 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1714 const u_char *tptr, u_int len,
1715 char *buf, size_t buflen,
1716 int add_path4, int add_path6)
1717 {
1718 int advance;
1719 u_int path_id = 0;
1720
1721 switch (af<<8 | safi) {
1722 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1723 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1724 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1725 if (add_path4) {
1726 path_id = GET_BE_U_4(tptr);
1727 tptr += 4;
1728 }
1729 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1730 if (advance == -1)
1731 ND_PRINT("\n\t (illegal prefix length)");
1732 else if (advance == -2)
1733 break; /* bytes left, but not enough */
1734 else
1735 ND_PRINT("\n\t %s", buf);
1736 if (add_path4) {
1737 ND_PRINT(" Path Id: %u", path_id);
1738 advance += 4;
1739 }
1740 break;
1741 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1742 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1743 if (advance == -1)
1744 ND_PRINT("\n\t (illegal prefix length)");
1745 else if (advance == -2)
1746 goto trunc;
1747 else if (advance == -3)
1748 break; /* bytes left, but not enough */
1749 else
1750 ND_PRINT("\n\t %s", buf);
1751 break;
1752 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1753 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1754 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1755 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1756 if (advance == -1)
1757 ND_PRINT("\n\t (illegal prefix length)");
1758 else
1759 ND_PRINT("\n\t %s", buf);
1760 break;
1761 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1762 advance = decode_rt_routing_info(ndo, tptr);
1763 break;
1764 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1765 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1766 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1767 if (advance == -1)
1768 ND_PRINT("\n\t (illegal prefix length)");
1769 else if (advance == -2)
1770 goto trunc;
1771 else
1772 ND_PRINT("\n\t %s", buf);
1773 break;
1774
1775 case (AFNUM_INET<<8 | SAFNUM_MDT):
1776 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1777 if (advance == -1)
1778 ND_PRINT("\n\t (illegal prefix length)");
1779 else if (advance == -2)
1780 goto trunc;
1781 else
1782 ND_PRINT("\n\t %s", buf);
1783 break;
1784 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1785 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1786 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1787 if (add_path6) {
1788 path_id = GET_BE_U_4(tptr);
1789 tptr += 4;
1790 }
1791 advance = decode_prefix6(ndo, tptr, len, buf, buflen);
1792 if (advance == -1)
1793 ND_PRINT("\n\t (illegal prefix length)");
1794 else if (advance == -2)
1795 break; /* bytes left, but not enough */
1796 else
1797 ND_PRINT("\n\t %s", buf);
1798 if (add_path6) {
1799 ND_PRINT(" Path Id: %u", path_id);
1800 advance += 4;
1801 }
1802 break;
1803 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1804 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1805 if (advance == -1)
1806 ND_PRINT("\n\t (illegal prefix length)");
1807 else if (advance == -2)
1808 goto trunc;
1809 else if (advance == -3)
1810 break; /* bytes left, but not enough */
1811 else
1812 ND_PRINT("\n\t %s", buf);
1813 break;
1814 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1815 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1816 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1817 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1818 if (advance == -1)
1819 ND_PRINT("\n\t (illegal prefix length)");
1820 else
1821 ND_PRINT("\n\t %s", buf);
1822 break;
1823 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1824 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1825 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1826 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1827 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1828 if (advance == -1)
1829 ND_PRINT("\n\t (illegal length)");
1830 else if (advance == -2)
1831 goto trunc;
1832 else
1833 ND_PRINT("\n\t %s", buf);
1834 break;
1835 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1836 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1837 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1838 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1839 if (advance == -1)
1840 ND_PRINT("\n\t (illegal prefix length)");
1841 else
1842 ND_PRINT("\n\t %s", buf);
1843 break;
1844 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1845 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1846 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1847 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1848 if (advance == -1)
1849 ND_PRINT("\n\t (illegal prefix length)");
1850 else
1851 ND_PRINT("\n\t %s", buf);
1852 break;
1853 default:
1854 /*
1855 * This should not happen, we should have been protected
1856 * by bgp_mp_af_print()'s return value.
1857 */
1858 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1859 advance = -4;
1860 break;
1861 }
1862 return advance;
1863 trunc: /* we rely on the caller to recognize -2 return value */
1864 return -2;
1865 }
1866
1867 static int
1868 bgp_attr_print(netdissect_options *ndo,
1869 uint8_t atype, const u_char *pptr, u_int len,
1870 const unsigned attr_set_level)
1871 {
1872 /* allocate space for the largest possible string */
1873 char astostr[AS_STR_SIZE];
1874 u_int i;
1875 uint16_t af;
1876 uint8_t safi, snpa, nhlen;
1877 int advance;
1878 u_int tlen;
1879 const u_char *tptr;
1880 char buf[MAXHOSTNAMELEN + 100];
1881 u_int as_size;
1882 int add_path4, add_path6;
1883 int ret;
1884
1885 tptr = pptr;
1886 tlen = len;
1887
1888 switch (atype) {
1889 case BGPTYPE_ORIGIN:
1890 if (len != 1)
1891 ND_PRINT("invalid len");
1892 else {
1893 ND_PRINT("%s", tok2str(bgp_origin_values,
1894 "Unknown Origin Typecode",
1895 GET_U_1(tptr)));
1896 }
1897 break;
1898
1899 /*
1900 * Process AS4 byte path and AS2 byte path attributes here.
1901 */
1902 case BGPTYPE_AS4_PATH:
1903 case BGPTYPE_AS_PATH:
1904 if (len % 2) {
1905 ND_PRINT("invalid len");
1906 break;
1907 }
1908 if (!len) {
1909 ND_PRINT("empty");
1910 break;
1911 }
1912
1913 /*
1914 * BGP updates exchanged between New speakers that support 4
1915 * byte AS, ASs are always encoded in 4 bytes. There is no
1916 * definitive way to find this, just by the packet's
1917 * contents. So, check for packet's TLV's sanity assuming
1918 * 2 bytes first, and it does not pass, assume that ASs are
1919 * encoded in 4 bytes format and move on.
1920 */
1921 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1922
1923 while (tptr < pptr + len) {
1924 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1925 "?", GET_U_1(tptr)));
1926 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1927 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1928 ND_PRINT("%s ",
1929 as_printf(ndo, astostr, sizeof(astostr),
1930 as_size == 2 ?
1931 GET_BE_U_2(tptr + i + 2) :
1932 GET_BE_U_4(tptr + i + 2)));
1933 }
1934 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1935 "?", GET_U_1(tptr)));
1936 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1937 }
1938 break;
1939 case BGPTYPE_NEXT_HOP:
1940 if (len != 4)
1941 ND_PRINT("invalid len");
1942 else {
1943 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
1944 }
1945 break;
1946 case BGPTYPE_MULTI_EXIT_DISC:
1947 case BGPTYPE_LOCAL_PREF:
1948 if (len != 4)
1949 ND_PRINT("invalid len");
1950 else {
1951 ND_PRINT("%u", GET_BE_U_4(tptr));
1952 }
1953 break;
1954 case BGPTYPE_ATOMIC_AGGREGATE:
1955 if (len != 0)
1956 ND_PRINT("invalid len");
1957 break;
1958 case BGPTYPE_AGGREGATOR:
1959
1960 /*
1961 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
1962 * the length of this PA can be either 6 bytes or 8 bytes.
1963 */
1964 if (len != 6 && len != 8) {
1965 ND_PRINT("invalid len");
1966 break;
1967 }
1968 ND_TCHECK_LEN(tptr, len);
1969 if (len == 6) {
1970 ND_PRINT(" AS #%s, origin %s",
1971 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
1972 GET_IPADDR_STRING(tptr + 2));
1973 } else {
1974 ND_PRINT(" AS #%s, origin %s",
1975 as_printf(ndo, astostr, sizeof(astostr),
1976 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
1977 }
1978 break;
1979 case BGPTYPE_AGGREGATOR4:
1980 if (len != 8) {
1981 ND_PRINT("invalid len");
1982 break;
1983 }
1984 ND_PRINT(" AS #%s, origin %s",
1985 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
1986 GET_IPADDR_STRING(tptr + 4));
1987 break;
1988 case BGPTYPE_COMMUNITIES:
1989 if (len % 4) {
1990 ND_PRINT("invalid len");
1991 break;
1992 }
1993 while (tlen != 0) {
1994 uint32_t comm;
1995 ND_TCHECK_4(tptr);
1996 if (tlen < 4)
1997 goto trunc;
1998 comm = GET_BE_U_4(tptr);
1999 switch (comm) {
2000 case BGP_COMMUNITY_NO_EXPORT:
2001 ND_PRINT(" NO_EXPORT");
2002 break;
2003 case BGP_COMMUNITY_NO_ADVERT:
2004 ND_PRINT(" NO_ADVERTISE");
2005 break;
2006 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2007 ND_PRINT(" NO_EXPORT_SUBCONFED");
2008 break;
2009 default:
2010 ND_PRINT("%u:%u%s",
2011 (comm >> 16) & 0xffff,
2012 comm & 0xffff,
2013 (tlen>4) ? ", " : "");
2014 break;
2015 }
2016 tlen -=4;
2017 tptr +=4;
2018 }
2019 break;
2020 case BGPTYPE_ORIGINATOR_ID:
2021 if (len != 4) {
2022 ND_PRINT("invalid len");
2023 break;
2024 }
2025 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2026 break;
2027 case BGPTYPE_CLUSTER_LIST:
2028 if (len % 4) {
2029 ND_PRINT("invalid len");
2030 break;
2031 }
2032 while (tlen != 0) {
2033 if (tlen < 4)
2034 goto trunc;
2035 ND_PRINT("%s%s",
2036 GET_IPADDR_STRING(tptr),
2037 (tlen>4) ? ", " : "");
2038 tlen -=4;
2039 tptr +=4;
2040 }
2041 break;
2042 case BGPTYPE_MP_REACH_NLRI:
2043 ND_TCHECK_3(tptr);
2044 if (tlen < 3)
2045 goto trunc;
2046 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2047 if (ret == -2)
2048 goto trunc;
2049 if (ret < 0)
2050 break;
2051
2052 tptr += 3;
2053 tlen -= 3;
2054
2055 ND_TCHECK_1(tptr);
2056 if (tlen < 1)
2057 goto trunc;
2058 nhlen = GET_U_1(tptr);
2059 tptr++;
2060 tlen--;
2061
2062 if (nhlen) {
2063 u_int nnh = 0;
2064 uint8_t tnhlen = nhlen;
2065 if (tlen < tnhlen)
2066 goto trunc;
2067 ND_PRINT("\n\t nexthop: ");
2068 while (tnhlen != 0) {
2069 if (nnh++ > 0) {
2070 ND_PRINT(", " );
2071 }
2072 switch(af<<8 | safi) {
2073 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2074 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2075 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2076 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2077 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2078 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2079 case (AFNUM_INET<<8 | SAFNUM_MDT):
2080 if (tnhlen < sizeof(nd_ipv4)) {
2081 ND_PRINT("invalid len");
2082 tptr += tnhlen;
2083 tlen -= tnhlen;
2084 tnhlen = 0;
2085 } else {
2086 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2087 tptr += sizeof(nd_ipv4);
2088 tnhlen -= sizeof(nd_ipv4);
2089 tlen -= sizeof(nd_ipv4);
2090 }
2091 break;
2092 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2093 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2094 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2095 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2096 ND_PRINT("invalid len");
2097 tptr += tnhlen;
2098 tlen -= tnhlen;
2099 tnhlen = 0;
2100 } else {
2101 ND_PRINT("RD: %s, %s",
2102 bgp_vpn_rd_print(ndo, tptr),
2103 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2104 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2105 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2106 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2107 }
2108 break;
2109 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2110 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2111 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2112 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2113 if (tnhlen < sizeof(nd_ipv6)) {
2114 ND_PRINT("invalid len");
2115 tptr += tnhlen;
2116 tlen -= tnhlen;
2117 tnhlen = 0;
2118 } else {
2119 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2120 tptr += sizeof(nd_ipv6);
2121 tlen -= sizeof(nd_ipv6);
2122 tnhlen -= sizeof(nd_ipv6);
2123 }
2124 break;
2125 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2126 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2127 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2128 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2129 ND_PRINT("invalid len");
2130 tptr += tnhlen;
2131 tlen -= tnhlen;
2132 tnhlen = 0;
2133 } else {
2134 ND_PRINT("RD: %s, %s",
2135 bgp_vpn_rd_print(ndo, tptr),
2136 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2137 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2138 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2139 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2140 }
2141 break;
2142 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2143 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2144 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2145 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2146 if (tnhlen < sizeof(nd_ipv4)) {
2147 ND_PRINT("invalid len");
2148 tptr += tnhlen;
2149 tlen -= tnhlen;
2150 tnhlen = 0;
2151 } else {
2152 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2153 tptr += (sizeof(nd_ipv4));
2154 tlen -= (sizeof(nd_ipv4));
2155 tnhlen -= (sizeof(nd_ipv4));
2156 }
2157 break;
2158 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2159 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2160 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2161 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2162 tptr += tnhlen;
2163 tlen -= tnhlen;
2164 tnhlen = 0;
2165 break;
2166
2167 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2168 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2169 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2170 if (tnhlen < BGP_VPN_RD_LEN+1) {
2171 ND_PRINT("invalid len");
2172 tptr += tnhlen;
2173 tlen -= tnhlen;
2174 tnhlen = 0;
2175 } else {
2176 ND_TCHECK_LEN(tptr, tnhlen);
2177 ND_PRINT("RD: %s, %s",
2178 bgp_vpn_rd_print(ndo, tptr),
2179 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2180 /* rfc986 mapped IPv4 address ? */
2181 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2182 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2183 /* rfc1888 mapped IPv6 address ? */
2184 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2185 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2186 tptr += tnhlen;
2187 tlen -= tnhlen;
2188 tnhlen = 0;
2189 }
2190 break;
2191 default:
2192 /*
2193 * bgp_mp_af_print() should have saved us from
2194 * an unsupported AFI/SAFI.
2195 */
2196 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2197 tptr += tnhlen;
2198 tlen -= tnhlen;
2199 tnhlen = 0;
2200 goto done;
2201 break;
2202 }
2203 }
2204 }
2205 ND_PRINT(", nh-length: %u", nhlen);
2206
2207 /* As per RFC 2858; this is reserved in RFC 4760 */
2208 if (tlen < 1)
2209 goto trunc;
2210 snpa = GET_U_1(tptr);
2211 tptr++;
2212 tlen--;
2213
2214 if (snpa) {
2215 ND_PRINT("\n\t %u SNPA", snpa);
2216 for (/*nothing*/; snpa != 0; snpa--) {
2217 uint8_t snpalen;
2218 if (tlen < 1)
2219 goto trunc;
2220 snpalen = GET_U_1(tptr);
2221 ND_PRINT("\n\t %u bytes", snpalen);
2222 tptr++;
2223 tlen--;
2224 if (tlen < snpalen)
2225 goto trunc;
2226 ND_TCHECK_LEN(tptr, snpalen);
2227 tptr += snpalen;
2228 tlen -= snpalen;
2229 }
2230 } else {
2231 ND_PRINT(", no SNPA");
2232 }
2233
2234 add_path4 = check_add_path(ndo, tptr,
2235 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2236 add_path6 = check_add_path(ndo, tptr,
2237 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2238
2239 while (tptr < pptr + len) {
2240 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2241 add_path4, add_path6);
2242 if (advance == -2)
2243 goto trunc;
2244 if (advance < 0)
2245 break;
2246 tptr += advance;
2247 }
2248 break;
2249
2250 case BGPTYPE_MP_UNREACH_NLRI:
2251 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2252 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2253 if (ret == -2)
2254 goto trunc;
2255 if (ret < 0)
2256 break;
2257
2258 if (len == BGP_MP_NLRI_MINSIZE)
2259 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2260
2261 tptr += 3;
2262
2263 add_path4 = check_add_path(ndo, tptr,
2264 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2265 add_path6 = check_add_path(ndo, tptr,
2266 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2267
2268 while (tptr < pptr + len) {
2269 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2270 add_path4, add_path6);
2271 if (advance == -2)
2272 goto trunc;
2273 if (advance < 0)
2274 break;
2275 tptr += advance;
2276 }
2277 break;
2278 case BGPTYPE_EXTD_COMMUNITIES:
2279 if (len % 8) {
2280 ND_PRINT("invalid len");
2281 break;
2282 }
2283 while (tlen != 0) {
2284 uint16_t extd_comm;
2285
2286 ND_TCHECK_2(tptr);
2287 if (tlen < 2)
2288 goto trunc;
2289 extd_comm=GET_BE_U_2(tptr);
2290
2291 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2292 tok2str(bgp_extd_comm_subtype_values,
2293 "unknown extd community typecode",
2294 extd_comm),
2295 extd_comm,
2296 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2297
2298 ND_TCHECK_8(tptr);
2299 if (tlen < 8)
2300 goto trunc;
2301 ND_PRINT(": ");
2302 bgp_extended_community_print(ndo, tptr);
2303 tlen -= 8;
2304 tptr += 8;
2305 }
2306 break;
2307
2308 case BGPTYPE_PMSI_TUNNEL:
2309 {
2310 uint8_t tunnel_type, flags;
2311
2312 ND_TCHECK_5(tptr);
2313 if (tlen < 5)
2314 goto trunc;
2315 flags = GET_U_1(tptr);
2316 tunnel_type = GET_U_1(tptr + 1);
2317
2318 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2319 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2320 tunnel_type,
2321 bittok2str(bgp_pmsi_flag_values, "none", flags),
2322 GET_BE_U_3(tptr + 2)>>4);
2323
2324 tptr +=5;
2325 tlen -= 5;
2326
2327 switch (tunnel_type) {
2328 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2329 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2330 ND_PRINT("\n\t Sender %s, P-Group %s",
2331 GET_IPADDR_STRING(tptr),
2332 GET_IPADDR_STRING(tptr+4));
2333 break;
2334
2335 case BGP_PMSI_TUNNEL_PIM_SSM:
2336 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2337 GET_IPADDR_STRING(tptr),
2338 GET_IPADDR_STRING(tptr+4));
2339 break;
2340 case BGP_PMSI_TUNNEL_INGRESS:
2341 ND_PRINT("\n\t Tunnel-Endpoint %s",
2342 GET_IPADDR_STRING(tptr));
2343 break;
2344 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2345 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2346 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2347 GET_IPADDR_STRING(tptr),
2348 GET_BE_U_4(tptr + 4));
2349 break;
2350 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2351 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2352 GET_IPADDR_STRING(tptr),
2353 GET_BE_U_4(tptr + 4));
2354 break;
2355 default:
2356 if (ndo->ndo_vflag <= 1) {
2357 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2358 }
2359 }
2360 break;
2361 }
2362 case BGPTYPE_AIGP:
2363 {
2364 uint8_t type;
2365 uint16_t length;
2366
2367 while (tlen >= 3) {
2368 type = GET_U_1(tptr);
2369 length = GET_BE_U_2(tptr + 1);
2370 tptr += 3;
2371 tlen -= 3;
2372
2373 ND_PRINT("\n\t %s TLV (%u), length %u",
2374 tok2str(bgp_aigp_values, "Unknown", type),
2375 type, length);
2376
2377 if (length < 3)
2378 goto trunc;
2379 length -= 3;
2380
2381 /*
2382 * Check if we can read the TLV data.
2383 */
2384 if (tlen < length)
2385 goto trunc;
2386
2387 switch (type) {
2388
2389 case BGP_AIGP_TLV:
2390 if (length < 8)
2391 goto trunc;
2392 ND_PRINT(", metric %" PRIu64,
2393 GET_BE_U_8(tptr));
2394 break;
2395
2396 default:
2397 if (ndo->ndo_vflag <= 1) {
2398 print_unknown_data(ndo, tptr,"\n\t ", length);
2399 }
2400 }
2401
2402 tptr += length;
2403 tlen -= length;
2404 }
2405 break;
2406 }
2407 case BGPTYPE_ATTR_SET:
2408 ND_TCHECK_4(tptr);
2409 if (len < 4)
2410 goto trunc;
2411 ND_PRINT("\n\t Origin AS: %s",
2412 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2413 tptr += 4;
2414 len -= 4;
2415
2416 while (len) {
2417 u_int aflags, alenlen, alen;
2418
2419 ND_TCHECK_2(tptr);
2420 if (len < 2) {
2421 ND_PRINT(" [path attr too short]");
2422 tptr += len;
2423 break;
2424 }
2425 aflags = GET_U_1(tptr);
2426 atype = GET_U_1(tptr + 1);
2427 tptr += 2;
2428 len -= 2;
2429 alenlen = bgp_attr_lenlen(aflags, tptr);
2430 ND_TCHECK_LEN(tptr, alenlen);
2431 if (len < alenlen) {
2432 ND_PRINT(" [path attr too short]");
2433 tptr += len;
2434 break;
2435 }
2436 alen = bgp_attr_len(aflags, tptr);
2437 tptr += alenlen;
2438 len -= alenlen;
2439
2440 ND_PRINT("\n\t %s (%u), length: %u",
2441 tok2str(bgp_attr_values,
2442 "Unknown Attribute", atype),
2443 atype,
2444 alen);
2445
2446 if (aflags) {
2447 ND_PRINT(", Flags [%s%s%s%s",
2448 aflags & 0x80 ? "O" : "",
2449 aflags & 0x40 ? "T" : "",
2450 aflags & 0x20 ? "P" : "",
2451 aflags & 0x10 ? "E" : "");
2452 if (aflags & 0xf)
2453 ND_PRINT("+%x", aflags & 0xf);
2454 ND_PRINT("]");
2455 }
2456 ND_PRINT(": ");
2457 if (len < alen) {
2458 ND_PRINT(" [path attr too short]");
2459 tptr += len;
2460 break;
2461 }
2462 /*
2463 * The protocol encoding per se allows ATTR_SET to be nested
2464 * as many times as the message can accommodate. This printer
2465 * used to be able to recurse into ATTR_SET contents until the
2466 * stack exhaustion, but now there is a limit on that (if live
2467 * protocol exchange goes that many levels deep, something is
2468 * probably wrong anyway). Feel free to refine this value if
2469 * you can find the spec with respective normative text.
2470 */
2471 if (attr_set_level == 10)
2472 ND_PRINT("(too many nested levels, not recursing)");
2473 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2474 return 0;
2475 tptr += alen;
2476 len -= alen;
2477 }
2478 break;
2479
2480 case BGPTYPE_LARGE_COMMUNITY:
2481 if (len == 0 || len % 12) {
2482 ND_PRINT("invalid len");
2483 break;
2484 }
2485 ND_PRINT("\n\t ");
2486 while (len != 0) {
2487 ND_PRINT("%u:%u:%u%s",
2488 GET_BE_U_4(tptr),
2489 GET_BE_U_4(tptr + 4),
2490 GET_BE_U_4(tptr + 8),
2491 (len > 12) ? ", " : "");
2492 tptr += 12;
2493 /*
2494 * len will always be a multiple of 12, as per the above,
2495 * so this will never underflow.
2496 */
2497 len -= 12;
2498 }
2499 break;
2500 default:
2501 ND_TCHECK_LEN(pptr, len);
2502 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2503 if (ndo->ndo_vflag <= 1)
2504 print_unknown_data(ndo, pptr, "\n\t ", len);
2505 break;
2506 }
2507 done:
2508 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2509 ND_TCHECK_LEN(pptr, len);
2510 print_unknown_data(ndo, pptr, "\n\t ", len);
2511 }
2512 return 1;
2513
2514 trunc:
2515 return 0;
2516 }
2517
2518 static void
2519 bgp_capabilities_print(netdissect_options *ndo,
2520 const u_char *opt, u_int caps_len)
2521 {
2522 /* allocate space for the largest possible string */
2523 char astostr[AS_STR_SIZE];
2524 u_int cap_type, cap_len, tcap_len, cap_offset;
2525 u_int i = 0;
2526
2527 while (i < caps_len) {
2528 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2529 cap_type=GET_U_1(opt + i);
2530 cap_len=GET_U_1(opt + i + 1);
2531 ND_PRINT("\n\t %s (%u), length: %u",
2532 tok2str(bgp_capcode_values, "Unknown", cap_type),
2533 cap_type,
2534 cap_len);
2535 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2536 switch (cap_type) {
2537 case BGP_CAPCODE_MP:
2538 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2539 if (cap_len < 4) {
2540 ND_PRINT(" (too short, < 4)");
2541 return;
2542 }
2543 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2544 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2545 GET_BE_U_2(opt + i + 2),
2546 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2547 GET_U_1(opt + i + 5));
2548 break;
2549 case BGP_CAPCODE_ML:
2550 cap_offset = 2;
2551 tcap_len = cap_len;
2552 while (tcap_len >= 4) {
2553 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2554 tok2str(af_values, "Unknown",
2555 GET_BE_U_2(opt + i + cap_offset)),
2556 GET_BE_U_2(opt + i + cap_offset),
2557 tok2str(bgp_safi_values, "Unknown",
2558 GET_U_1(opt + i + cap_offset + 2)),
2559 GET_U_1(opt + i + cap_offset + 2),
2560 GET_U_1(opt + i + cap_offset + 3));
2561 tcap_len -= 4;
2562 cap_offset += 4;
2563 }
2564 break;
2565 case BGP_CAPCODE_RESTART:
2566 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2567 if (cap_len < 2) {
2568 ND_PRINT(" (too short, < 2)");
2569 return;
2570 }
2571 tcap_len=cap_len;
2572 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2573 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2574 GET_BE_U_2(opt + i + 2)&0xfff);
2575 tcap_len-=2;
2576 cap_offset=4;
2577 while(tcap_len>=4) {
2578 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2579 tok2str(af_values,"Unknown",
2580 GET_BE_U_2(opt + i + cap_offset)),
2581 GET_BE_U_2(opt + i + cap_offset),
2582 tok2str(bgp_safi_values,"Unknown",
2583 GET_U_1(opt + i + cap_offset + 2)),
2584 GET_U_1(opt + (i + cap_offset + 2)),
2585 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2586 tcap_len -= 4;
2587 cap_offset += 4;
2588 }
2589 break;
2590 case BGP_CAPCODE_RR:
2591 case BGP_CAPCODE_LLGR:
2592 case BGP_CAPCODE_RR_CISCO:
2593 break;
2594 case BGP_CAPCODE_AS_NEW:
2595 /*
2596 * Extract the 4 byte AS number encoded.
2597 */
2598 if (cap_len < 4) {
2599 ND_PRINT(" (too short, < 4)");
2600 return;
2601 }
2602 ND_PRINT("\n\t\t 4 Byte AS %s",
2603 as_printf(ndo, astostr, sizeof(astostr),
2604 GET_BE_U_4(opt + i + 2)));
2605 break;
2606 case BGP_CAPCODE_ADD_PATH:
2607 if (cap_len == 0) {
2608 ND_PRINT(" (bogus)"); /* length */
2609 break;
2610 }
2611 tcap_len=cap_len;
2612 cap_offset=2;
2613 while (tcap_len != 0) {
2614 if (tcap_len < 4) {
2615 nd_print_invalid(ndo);
2616 break;
2617 }
2618 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2619 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2620 GET_BE_U_2(opt + i + cap_offset),
2621 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2622 GET_U_1(opt + (i + cap_offset + 2)),
2623 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2624 );
2625 tcap_len -= 4;
2626 cap_offset += 4;
2627 }
2628 break;
2629 default:
2630 ND_PRINT("\n\t\tno decoder for Capability %u",
2631 cap_type);
2632 if (ndo->ndo_vflag <= 1)
2633 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2634 cap_len);
2635 break;
2636 }
2637 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2638 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2639 }
2640 i += BGP_CAP_HEADER_SIZE + cap_len;
2641 }
2642 return;
2643
2644 trunc:
2645 nd_print_trunc(ndo);
2646 }
2647
2648 static void
2649 bgp_open_print(netdissect_options *ndo,
2650 const u_char *dat, u_int length)
2651 {
2652 /* allocate space for the largest possible string */
2653 char astostr[AS_STR_SIZE];
2654 const struct bgp_open *bgp_open_header;
2655 u_int optslen;
2656 const struct bgp_opt *bgpopt;
2657 const u_char *opt;
2658 u_int i;
2659
2660 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2661 if (length < BGP_OPEN_SIZE)
2662 goto trunc;
2663
2664 bgp_open_header = (const struct bgp_open *)dat;
2665
2666 ND_PRINT("\n\t Version %u, ",
2667 GET_U_1(bgp_open_header->bgpo_version));
2668 ND_PRINT("my AS %s, ",
2669 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2670 ND_PRINT("Holdtime %us, ",
2671 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2672 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2673 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2674 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2675
2676 opt = dat + BGP_OPEN_SIZE;
2677 length -= BGP_OPEN_SIZE;
2678
2679 i = 0;
2680 while (i < optslen) {
2681 uint8_t opt_type, opt_len;
2682
2683 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2684 if (length < BGP_OPT_SIZE + i)
2685 goto trunc;
2686 bgpopt = (const struct bgp_opt *)(opt + i);
2687 opt_type = GET_U_1(bgpopt->bgpopt_type);
2688 opt_len = GET_U_1(bgpopt->bgpopt_len);
2689 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2690 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2691 opt_type, opt_len);
2692 break;
2693 }
2694
2695 ND_PRINT("\n\t Option %s (%u), length: %u",
2696 tok2str(bgp_opt_values,"Unknown",opt_type),
2697 opt_type,
2698 opt_len);
2699
2700 /* now let's decode the options we know*/
2701 switch(opt_type) {
2702
2703 case BGP_OPT_CAP:
2704 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2705 opt_len);
2706 break;
2707
2708 case BGP_OPT_AUTH:
2709 default:
2710 ND_PRINT("\n\t no decoder for option %u",
2711 opt_type);
2712 break;
2713 }
2714 i += BGP_OPT_SIZE + opt_len;
2715 }
2716 return;
2717 trunc:
2718 nd_print_trunc(ndo);
2719 }
2720
2721 static void
2722 bgp_update_print(netdissect_options *ndo,
2723 const u_char *dat, u_int length)
2724 {
2725 const u_char *p;
2726 u_int withdrawn_routes_len;
2727 char buf[MAXHOSTNAMELEN + 100];
2728 int wpfx;
2729 u_int len;
2730 int i;
2731 int add_path;
2732 u_int path_id = 0;
2733
2734 ND_TCHECK_LEN(dat, BGP_SIZE);
2735 if (length < BGP_SIZE)
2736 goto trunc;
2737 p = dat + BGP_SIZE;
2738 length -= BGP_SIZE;
2739
2740 /* Unfeasible routes */
2741 ND_TCHECK_2(p);
2742 if (length < 2)
2743 goto trunc;
2744 withdrawn_routes_len = GET_BE_U_2(p);
2745 p += 2;
2746 length -= 2;
2747 if (withdrawn_routes_len > 1) {
2748 /*
2749 * Without keeping state from the original NLRI message,
2750 * it's not possible to tell if this a v4 or v6 route,
2751 * so only try to decode it if we're not v6 enabled.
2752 */
2753 ND_TCHECK_LEN(p, withdrawn_routes_len);
2754 if (length < withdrawn_routes_len)
2755 goto trunc;
2756 ND_PRINT("\n\t Withdrawn routes:");
2757 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2758 while (withdrawn_routes_len != 0) {
2759 if (add_path) {
2760 if (withdrawn_routes_len < 4) {
2761 p += withdrawn_routes_len;
2762 length -= withdrawn_routes_len;
2763 break;
2764 }
2765 path_id = GET_BE_U_4(p);
2766 p += 4;
2767 length -= 4;
2768 withdrawn_routes_len -= 4;
2769 }
2770 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2771 if (wpfx == -1) {
2772 ND_PRINT("\n\t (illegal prefix length)");
2773 break;
2774 } else if (wpfx == -2)
2775 goto trunc; /* bytes left, but not enough */
2776 else {
2777 ND_PRINT("\n\t %s", buf);
2778 if (add_path) {
2779 ND_PRINT(" Path Id: %u", path_id);
2780 }
2781 p += wpfx;
2782 length -= wpfx;
2783 withdrawn_routes_len -= wpfx;
2784 }
2785 }
2786 } else {
2787 ND_TCHECK_LEN(p, withdrawn_routes_len);
2788 if (length < withdrawn_routes_len)
2789 goto trunc;
2790 p += withdrawn_routes_len;
2791 length -= withdrawn_routes_len;
2792 }
2793
2794 ND_TCHECK_2(p);
2795 if (length < 2)
2796 goto trunc;
2797 len = GET_BE_U_2(p);
2798 p += 2;
2799 length -= 2;
2800
2801 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2802 /* No withdrawn routes, no path attributes, no NLRI */
2803 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2804 return;
2805 }
2806
2807 if (len) {
2808 /* Make sure the path attributes don't go past the end of the packet */
2809 if (length < len)
2810 goto trunc;
2811 /* do something more useful!*/
2812 while (len) {
2813 uint8_t aflags, atype, alenlen;
2814 uint16_t alen;
2815
2816 ND_TCHECK_2(p);
2817 if (length < 2)
2818 goto trunc;
2819 if (len < 2) {
2820 ND_PRINT("\n\t [path attrs too short]");
2821 p += len;
2822 length -= len;
2823 break;
2824 }
2825 aflags = GET_U_1(p);
2826 atype = GET_U_1(p + 1);
2827 p += 2;
2828 len -= 2;
2829 length -= 2;
2830 alenlen = bgp_attr_lenlen(aflags, p);
2831 ND_TCHECK_LEN(p, alenlen);
2832 if (length < alenlen)
2833 goto trunc;
2834 if (len < alenlen) {
2835 ND_PRINT("\n\t [path attrs too short]");
2836 p += len;
2837 length -= len;
2838 break;
2839 }
2840 alen = bgp_attr_len(aflags, p);
2841 p += alenlen;
2842 len -= alenlen;
2843 length -= alenlen;
2844
2845 ND_PRINT("\n\t %s (%u), length: %u",
2846 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2847 atype,
2848 alen);
2849
2850 if (aflags) {
2851 ND_PRINT(", Flags [%s%s%s%s",
2852 aflags & 0x80 ? "O" : "",
2853 aflags & 0x40 ? "T" : "",
2854 aflags & 0x20 ? "P" : "",
2855 aflags & 0x10 ? "E" : "");
2856 if (aflags & 0xf)
2857 ND_PRINT("+%x", aflags & 0xf);
2858 ND_PRINT("]: ");
2859 }
2860 if (len < alen) {
2861 ND_PRINT(" [path attrs too short]");
2862 p += len;
2863 length -= len;
2864 break;
2865 }
2866 if (length < alen)
2867 goto trunc;
2868 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2869 goto trunc;
2870 p += alen;
2871 len -= alen;
2872 length -= alen;
2873 }
2874 }
2875
2876 if (length) {
2877 add_path = check_add_path(ndo, p, length, 32);
2878 ND_PRINT("\n\t Updated routes:");
2879 while (length != 0) {
2880 if (add_path) {
2881 ND_TCHECK_4(p);
2882 if (length < 4)
2883 goto trunc;
2884 path_id = GET_BE_U_4(p);
2885 p += 4;
2886 length -= 4;
2887 }
2888 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2889 if (i == -1) {
2890 ND_PRINT("\n\t (illegal prefix length)");
2891 break;
2892 } else if (i == -2)
2893 goto trunc; /* bytes left, but not enough */
2894 else {
2895 ND_PRINT("\n\t %s", buf);
2896 if (add_path) {
2897 ND_PRINT(" Path Id: %u", path_id);
2898 }
2899 p += i;
2900 length -= i;
2901 }
2902 }
2903 }
2904 return;
2905 trunc:
2906 nd_print_trunc(ndo);
2907 }
2908
2909 static void
2910 bgp_notification_print(netdissect_options *ndo,
2911 const u_char *dat, u_int length)
2912 {
2913 const struct bgp_notification *bgp_notification_header;
2914 const u_char *tptr;
2915 uint8_t bgpn_major, bgpn_minor;
2916
2917 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2918 if (length<BGP_NOTIFICATION_SIZE)
2919 return;
2920
2921 bgp_notification_header = (const struct bgp_notification *)dat;
2922 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
2923 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
2924
2925 ND_PRINT(", %s (%u)",
2926 tok2str(bgp_notify_major_values, "Unknown Error",
2927 bgpn_major),
2928 bgpn_major);
2929
2930 switch (bgpn_major) {
2931
2932 case BGP_NOTIFY_MAJOR_MSG:
2933 ND_PRINT(", subcode %s (%u)",
2934 tok2str(bgp_notify_minor_msg_values, "Unknown",
2935 bgpn_minor),
2936 bgpn_minor);
2937 break;
2938 case BGP_NOTIFY_MAJOR_OPEN:
2939 ND_PRINT(", subcode %s (%u)",
2940 tok2str(bgp_notify_minor_open_values, "Unknown",
2941 bgpn_minor),
2942 bgpn_minor);
2943 break;
2944 case BGP_NOTIFY_MAJOR_UPDATE:
2945 ND_PRINT(", subcode %s (%u)",
2946 tok2str(bgp_notify_minor_update_values, "Unknown",
2947 bgpn_minor),
2948 bgpn_minor);
2949 break;
2950 case BGP_NOTIFY_MAJOR_FSM:
2951 ND_PRINT(" subcode %s (%u)",
2952 tok2str(bgp_notify_minor_fsm_values, "Unknown",
2953 bgpn_minor),
2954 bgpn_minor);
2955 break;
2956 case BGP_NOTIFY_MAJOR_CAP:
2957 ND_PRINT(" subcode %s (%u)",
2958 tok2str(bgp_notify_minor_cap_values, "Unknown",
2959 bgpn_minor),
2960 bgpn_minor);
2961 break;
2962 case BGP_NOTIFY_MAJOR_CEASE:
2963 ND_PRINT(", subcode %s (%u)",
2964 tok2str(bgp_notify_minor_cease_values, "Unknown",
2965 bgpn_minor),
2966 bgpn_minor);
2967
2968 /* RFC 4486 mentions optionally 7 bytes
2969 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
2970 */
2971 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
2972 tptr = dat + BGP_NOTIFICATION_SIZE;
2973 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
2974 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
2975 GET_BE_U_2(tptr),
2976 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
2977 GET_U_1((tptr + 2)),
2978 GET_BE_U_4(tptr + 3));
2979 }
2980 /*
2981 * RFC 9003 describes a method to send a communication
2982 * intended for human consumption regarding the Administrative Shutdown
2983 */
2984 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
2985 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
2986 length >= BGP_NOTIFICATION_SIZE + 1) {
2987 tptr = dat + BGP_NOTIFICATION_SIZE;
2988 uint8_t shutdown_comm_length = GET_U_1(tptr);
2989 uint8_t remainder_offset = 0;
2990 /* garbage, hexdump it all */
2991 if (shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
2992 ND_PRINT(", invalid Shutdown Communication length");
2993 } else if (shutdown_comm_length == 0) {
2994 ND_PRINT(", empty Shutdown Communication");
2995 remainder_offset += 1;
2996 }
2997 /* a proper shutdown communication */
2998 else {
2999 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3000 (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL);
3001 ND_PRINT("\"");
3002 remainder_offset += shutdown_comm_length + 1;
3003 }
3004 /* if there is trailing data, hexdump it */
3005 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3006 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3007 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3008 }
3009 }
3010 break;
3011 default:
3012 break;
3013 }
3014
3015 return;
3016 trunc:
3017 nd_print_trunc(ndo);
3018 }
3019
3020 static void
3021 bgp_route_refresh_print(netdissect_options *ndo,
3022 const u_char *pptr, u_int len)
3023 {
3024 const struct bgp_route_refresh *bgp_route_refresh_header;
3025
3026 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3027
3028 /* some little sanity checking */
3029 if (len<BGP_ROUTE_REFRESH_SIZE)
3030 return;
3031
3032 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3033
3034 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3035 tok2str(af_values,"Unknown",
3036 GET_BE_U_2(bgp_route_refresh_header->afi)),
3037 GET_BE_U_2(bgp_route_refresh_header->afi),
3038 tok2str(bgp_safi_values,"Unknown",
3039 GET_U_1(bgp_route_refresh_header->safi)),
3040 GET_U_1(bgp_route_refresh_header->safi));
3041
3042 if (ndo->ndo_vflag > 1) {
3043 ND_TCHECK_LEN(pptr, len);
3044 print_unknown_data(ndo, pptr, "\n\t ", len);
3045 }
3046
3047 return;
3048 trunc:
3049 nd_print_trunc(ndo);
3050 }
3051
3052 static int
3053 bgp_pdu_print(netdissect_options *ndo,
3054 const u_char *dat, u_int length)
3055 {
3056 const struct bgp *bgp_header;
3057 uint8_t bgp_type;
3058
3059 ND_TCHECK_LEN(dat, BGP_SIZE);
3060 bgp_header = (const struct bgp *)dat;
3061 bgp_type = GET_U_1(bgp_header->bgp_type);
3062
3063 ND_PRINT("\n\t%s Message (%u), length: %u",
3064 tok2str(bgp_msg_values, "Unknown", bgp_type),
3065 bgp_type,
3066 length);
3067
3068 switch (bgp_type) {
3069 case BGP_OPEN:
3070 bgp_open_print(ndo, dat, length);
3071 break;
3072 case BGP_UPDATE:
3073 bgp_update_print(ndo, dat, length);
3074 break;
3075 case BGP_NOTIFICATION:
3076 bgp_notification_print(ndo, dat, length);
3077 break;
3078 case BGP_KEEPALIVE:
3079 break;
3080 case BGP_ROUTE_REFRESH:
3081 bgp_route_refresh_print(ndo, dat, length);
3082 break;
3083 default:
3084 /* we have no decoder for the BGP message */
3085 ND_TCHECK_LEN(dat, length);
3086 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3087 print_unknown_data(ndo, dat, "\n\t ", length);
3088 break;
3089 }
3090 return 1;
3091 trunc:
3092 nd_print_trunc(ndo);
3093 return 0;
3094 }
3095
3096 void
3097 bgp_print(netdissect_options *ndo,
3098 const u_char *dat, u_int length _U_)
3099 {
3100 const u_char *p;
3101 const u_char *ep = ndo->ndo_snapend;
3102 const u_char *start;
3103 const u_char marker[] = {
3104 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3105 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3106 };
3107 const struct bgp *bgp_header;
3108 uint16_t hlen;
3109
3110 ndo->ndo_protocol = "bgp";
3111 ND_PRINT(": BGP");
3112
3113 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3114 return;
3115
3116 p = dat;
3117 start = p;
3118 while (p < ep) {
3119 if (!ND_TTEST_1(p))
3120 break;
3121 if (GET_U_1(p) != 0xff) {
3122 p++;
3123 continue;
3124 }
3125
3126 if (!ND_TTEST_LEN(p, sizeof(marker)))
3127 break;
3128 if (memcmp(p, marker, sizeof(marker)) != 0) {
3129 p++;
3130 continue;
3131 }
3132
3133 /* found BGP header */
3134 ND_TCHECK_LEN(p, BGP_SIZE);
3135 bgp_header = (const struct bgp *)p;
3136
3137 if (start != p)
3138 nd_print_trunc(ndo);
3139
3140 hlen = GET_BE_U_2(bgp_header->bgp_len);
3141 if (hlen < BGP_SIZE) {
3142 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3143 nd_print_invalid(ndo);
3144 break;
3145 }
3146
3147 if (ND_TTEST_LEN(p, hlen)) {
3148 if (!bgp_pdu_print(ndo, p, hlen))
3149 return;
3150 p += hlen;
3151 start = p;
3152 } else {
3153 ND_PRINT("\n[|BGP %s]",
3154 tok2str(bgp_msg_values,
3155 "Unknown Message Type",
3156 GET_U_1(bgp_header->bgp_type)));
3157 break;
3158 }
3159 }
3160
3161 return;
3162
3163 trunc:
3164 nd_print_trunc(ndo);
3165 }
[mirror] the TCPdump network dissector