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 #include <sys/cdefs.h>
34 #ifndef lint
35 __RCSID("$NetBSD: print-bgp.c,v 1.13 2024/09/02 16:15:30 christos Exp $");
36 #endif
37
38 /* \summary: Border Gateway Protocol (BGP) printer */
39
40 /* specification: RFC 4271 */
41
42 #include <config.h>
43
44 #include "netdissect-stdinc.h"
45
46 #include <stdio.h>
47 #include <string.h>
48
49 #include "netdissect.h"
50 #include "addrtoname.h"
51 #include "extract.h"
52 #include "af.h"
53 #include "l2vpn.h"
54
55 struct bgp {
56 nd_byte bgp_marker[16];
57 nd_uint16_t bgp_len;
58 nd_uint8_t bgp_type;
59 };
60 #define BGP_SIZE 19 /* unaligned */
61
62 #define BGP_OPEN 1
63 #define BGP_UPDATE 2
64 #define BGP_NOTIFICATION 3
65 #define BGP_KEEPALIVE 4
66 #define BGP_ROUTE_REFRESH 5
67
68 static const struct tok bgp_msg_values[] = {
69 { BGP_OPEN, "Open"},
70 { BGP_UPDATE, "Update"},
71 { BGP_NOTIFICATION, "Notification"},
72 { BGP_KEEPALIVE, "Keepalive"},
73 { BGP_ROUTE_REFRESH, "Route Refresh"},
74 { 0, NULL}
75 };
76
77 struct bgp_open {
78 nd_byte bgpo_marker[16];
79 nd_uint16_t bgpo_len;
80 nd_uint8_t bgpo_type;
81 nd_uint8_t bgpo_version;
82 nd_uint16_t bgpo_myas;
83 nd_uint16_t bgpo_holdtime;
84 nd_uint32_t bgpo_id;
85 nd_uint8_t bgpo_optlen;
86 /* options should follow */
87 };
88 #define BGP_OPEN_SIZE 29 /* unaligned */
89
90 struct bgp_opt {
91 nd_uint8_t bgpopt_type;
92 nd_uint8_t bgpopt_len;
93 /* variable length */
94 };
95 #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */
96 #define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */
97
98 struct bgp_notification {
99 nd_byte bgpn_marker[16];
100 nd_uint16_t bgpn_len;
101 nd_uint8_t bgpn_type;
102 nd_uint8_t bgpn_major;
103 nd_uint8_t bgpn_minor;
104 };
105 #define BGP_NOTIFICATION_SIZE 21 /* unaligned */
106
107 struct bgp_route_refresh {
108 nd_byte bgp_marker[16];
109 nd_uint16_t len;
110 nd_uint8_t type; /* No padding after this; afi is, in fact, not aligned */
111 nd_uint16_t afi;
112 nd_uint8_t res;
113 nd_uint8_t safi;
114 };
115 #define BGP_ROUTE_REFRESH_SIZE 23
116
117 #define bgp_attr_lenlen(flags, p) \
118 (((flags) & 0x10) ? 2U : 1U)
119 #define bgp_attr_len(flags, p) \
120 (((flags) & 0x10) ? GET_BE_U_2(p) : GET_U_1(p))
121
122 #define BGPTYPE_ORIGIN 1
123 #define BGPTYPE_AS_PATH 2
124 #define BGPTYPE_NEXT_HOP 3
125 #define BGPTYPE_MULTI_EXIT_DISC 4
126 #define BGPTYPE_LOCAL_PREF 5
127 #define BGPTYPE_ATOMIC_AGGREGATE 6
128 #define BGPTYPE_AGGREGATOR 7
129 #define BGPTYPE_COMMUNITIES 8 /* RFC1997 */
130 #define BGPTYPE_ORIGINATOR_ID 9 /* RFC4456 */
131 #define BGPTYPE_CLUSTER_LIST 10 /* RFC4456 */
132 #define BGPTYPE_DPA 11 /* deprecated, draft-ietf-idr-bgp-dpa */
133 #define BGPTYPE_ADVERTISERS 12 /* deprecated RFC1863 */
134 #define BGPTYPE_RCID_PATH 13 /* deprecated RFC1863 */
135 #define BGPTYPE_MP_REACH_NLRI 14 /* RFC4760 */
136 #define BGPTYPE_MP_UNREACH_NLRI 15 /* RFC4760 */
137 #define BGPTYPE_EXTD_COMMUNITIES 16 /* RFC4360 */
138 #define BGPTYPE_AS4_PATH 17 /* RFC6793 */
139 #define BGPTYPE_AGGREGATOR4 18 /* RFC6793 */
140 #define BGPTYPE_PMSI_TUNNEL 22 /* RFC6514 */
141 #define BGPTYPE_TUNNEL_ENCAP 23 /* RFC5512 */
142 #define BGPTYPE_TRAFFIC_ENG 24 /* RFC5543 */
143 #define BGPTYPE_IPV6_EXTD_COMMUNITIES 25 /* RFC5701 */
144 #define BGPTYPE_AIGP 26 /* RFC7311 */
145 #define BGPTYPE_PE_DISTINGUISHER_LABEL 27 /* RFC6514 */
146 #define BGPTYPE_ENTROPY_LABEL 28 /* RFC6790 */
147 #define BGPTYPE_LARGE_COMMUNITY 32 /* draft-ietf-idr-large-community-05 */
148 #define BGPTYPE_ATTR_SET 128 /* RFC6368 */
149
150 #define BGP_MP_NLRI_MINSIZE 3 /* End of RIB Marker detection */
151
152 static const struct tok bgp_attr_values[] = {
153 { BGPTYPE_ORIGIN, "Origin"},
154 { BGPTYPE_AS_PATH, "AS Path"},
155 { BGPTYPE_AS4_PATH, "AS4 Path"},
156 { BGPTYPE_NEXT_HOP, "Next Hop"},
157 { BGPTYPE_MULTI_EXIT_DISC, "Multi Exit Discriminator"},
158 { BGPTYPE_LOCAL_PREF, "Local Preference"},
159 { BGPTYPE_ATOMIC_AGGREGATE, "Atomic Aggregate"},
160 { BGPTYPE_AGGREGATOR, "Aggregator"},
161 { BGPTYPE_AGGREGATOR4, "Aggregator4"},
162 { BGPTYPE_COMMUNITIES, "Community"},
163 { BGPTYPE_ORIGINATOR_ID, "Originator ID"},
164 { BGPTYPE_CLUSTER_LIST, "Cluster List"},
165 { BGPTYPE_DPA, "DPA"},
166 { BGPTYPE_ADVERTISERS, "Advertisers"},
167 { BGPTYPE_RCID_PATH, "RCID Path / Cluster ID"},
168 { BGPTYPE_MP_REACH_NLRI, "Multi-Protocol Reach NLRI"},
169 { BGPTYPE_MP_UNREACH_NLRI, "Multi-Protocol Unreach NLRI"},
170 { BGPTYPE_EXTD_COMMUNITIES, "Extended Community"},
171 { BGPTYPE_PMSI_TUNNEL, "PMSI Tunnel"},
172 { BGPTYPE_TUNNEL_ENCAP, "Tunnel Encapsulation"},
173 { BGPTYPE_TRAFFIC_ENG, "Traffic Engineering"},
174 { BGPTYPE_IPV6_EXTD_COMMUNITIES, "IPv6 Extended Community"},
175 { BGPTYPE_AIGP, "Accumulated IGP Metric"},
176 { BGPTYPE_PE_DISTINGUISHER_LABEL, "PE Distinguisher Label"},
177 { BGPTYPE_ENTROPY_LABEL, "Entropy Label"},
178 { BGPTYPE_LARGE_COMMUNITY, "Large Community"},
179 { BGPTYPE_ATTR_SET, "Attribute Set"},
180 { 255, "Reserved for development"},
181 { 0, NULL}
182 };
183
184 #define BGP_AS_SET 1
185 #define BGP_AS_SEQUENCE 2
186 #define BGP_CONFED_AS_SEQUENCE 3 /* draft-ietf-idr-rfc3065bis-01 */
187 #define BGP_CONFED_AS_SET 4 /* draft-ietf-idr-rfc3065bis-01 */
188
189 #define BGP_AS_SEG_TYPE_MIN BGP_AS_SET
190 #define BGP_AS_SEG_TYPE_MAX BGP_CONFED_AS_SET
191
192 static const struct tok bgp_as_path_segment_open_values[] = {
193 { BGP_AS_SEQUENCE, ""},
194 { BGP_AS_SET, "{ "},
195 { BGP_CONFED_AS_SEQUENCE, "( "},
196 { BGP_CONFED_AS_SET, "({ "},
197 { 0, NULL}
198 };
199
200 static const struct tok bgp_as_path_segment_close_values[] = {
201 { BGP_AS_SEQUENCE, ""},
202 { BGP_AS_SET, "}"},
203 { BGP_CONFED_AS_SEQUENCE, ")"},
204 { BGP_CONFED_AS_SET, "})"},
205 { 0, NULL}
206 };
207
208 #define BGP_OPT_AUTH 1
209 #define BGP_OPT_CAP 2
210
211 static const struct tok bgp_opt_values[] = {
212 { BGP_OPT_AUTH, "Authentication Information"},
213 { BGP_OPT_CAP, "Capabilities Advertisement"},
214 { 0, NULL}
215 };
216
217 #define BGP_CAPCODE_MP 1 /* RFC2858 */
218 #define BGP_CAPCODE_RR 2 /* RFC2918 */
219 #define BGP_CAPCODE_ORF 3 /* RFC5291 */
220 #define BGP_CAPCODE_MR 4 /* RFC3107 */
221 #define BGP_CAPCODE_EXT_NH 5 /* RFC5549 */
222 #define BGP_CAPCODE_ML 8 /* RFC8277 */
223 #define BGP_CAPCODE_RESTART 64 /* RFC4724 */
224 #define BGP_CAPCODE_AS_NEW 65 /* RFC6793 */
225 #define BGP_CAPCODE_DYN_CAP 67 /* draft-ietf-idr-dynamic-cap */
226 #define BGP_CAPCODE_MULTISESS 68 /* draft-ietf-idr-bgp-multisession */
227 #define BGP_CAPCODE_ADD_PATH 69 /* RFC7911 */
228 #define BGP_CAPCODE_ENH_RR 70 /* draft-keyur-bgp-enhanced-route-refresh */
229 #define BGP_CAPCODE_LLGR 71 /* draft-uttaro-idr-bgp-persistence-05 */
230 #define BGP_CAPCODE_RR_CISCO 128
231
232 static const struct tok bgp_capcode_values[] = {
233 { BGP_CAPCODE_MP, "Multiprotocol Extensions"},
234 { BGP_CAPCODE_RR, "Route Refresh"},
235 { BGP_CAPCODE_ORF, "Cooperative Route Filtering"},
236 { BGP_CAPCODE_MR, "Multiple Routes to a Destination"},
237 { BGP_CAPCODE_EXT_NH, "Extended Next Hop Encoding"},
238 { BGP_CAPCODE_ML, "Multiple Labels"},
239 { BGP_CAPCODE_RESTART, "Graceful Restart"},
240 { BGP_CAPCODE_AS_NEW, "32-Bit AS Number"},
241 { BGP_CAPCODE_DYN_CAP, "Dynamic Capability"},
242 { BGP_CAPCODE_MULTISESS, "Multisession BGP"},
243 { BGP_CAPCODE_ADD_PATH, "Multiple Paths"},
244 { BGP_CAPCODE_ENH_RR, "Enhanced Route Refresh"},
245 { BGP_CAPCODE_LLGR, "Long-lived Graceful Restart"},
246 { BGP_CAPCODE_RR_CISCO, "Route Refresh (Cisco)"},
247 { 0, NULL}
248 };
249
250 #define BGP_NOTIFY_MAJOR_MSG 1
251 #define BGP_NOTIFY_MAJOR_OPEN 2
252 #define BGP_NOTIFY_MAJOR_UPDATE 3
253 #define BGP_NOTIFY_MAJOR_HOLDTIME 4
254 #define BGP_NOTIFY_MAJOR_FSM 5
255 #define BGP_NOTIFY_MAJOR_CEASE 6
256 #define BGP_NOTIFY_MAJOR_CAP 7
257
258 static const struct tok bgp_notify_major_values[] = {
259 { BGP_NOTIFY_MAJOR_MSG, "Message Header Error"},
260 { BGP_NOTIFY_MAJOR_OPEN, "OPEN Message Error"},
261 { BGP_NOTIFY_MAJOR_UPDATE, "UPDATE Message Error"},
262 { BGP_NOTIFY_MAJOR_HOLDTIME,"Hold Timer Expired"},
263 { BGP_NOTIFY_MAJOR_FSM, "Finite State Machine Error"},
264 { BGP_NOTIFY_MAJOR_CEASE, "Cease"},
265 { BGP_NOTIFY_MAJOR_CAP, "Capability Message Error"},
266 { 0, NULL}
267 };
268
269 /* RFC 4486 */
270 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX 1
271 #define BGP_NOTIFY_MINOR_CEASE_SHUT 2
272 #define BGP_NOTIFY_MINOR_CEASE_RESET 4
273 static const struct tok bgp_notify_minor_cease_values[] = {
274 { BGP_NOTIFY_MINOR_CEASE_MAXPRFX, "Maximum Number of Prefixes Reached"},
275 { BGP_NOTIFY_MINOR_CEASE_SHUT, "Administrative Shutdown"},
276 { 3, "Peer Unconfigured"},
277 { BGP_NOTIFY_MINOR_CEASE_RESET, "Administrative Reset"},
278 { 5, "Connection Rejected"},
279 { 6, "Other Configuration Change"},
280 { 7, "Connection Collision Resolution"},
281 { 0, NULL}
282 };
283
284 static const struct tok bgp_notify_minor_msg_values[] = {
285 { 1, "Connection Not Synchronized"},
286 { 2, "Bad Message Length"},
287 { 3, "Bad Message Type"},
288 { 0, NULL}
289 };
290
291 static const struct tok bgp_notify_minor_open_values[] = {
292 { 1, "Unsupported Version Number"},
293 { 2, "Bad Peer AS"},
294 { 3, "Bad BGP Identifier"},
295 { 4, "Unsupported Optional Parameter"},
296 { 5, "Authentication Failure"},
297 { 6, "Unacceptable Hold Time"},
298 { 7, "Capability Message Error"},
299 { 0, NULL}
300 };
301
302 static const struct tok bgp_notify_minor_update_values[] = {
303 { 1, "Malformed Attribute List"},
304 { 2, "Unrecognized Well-known Attribute"},
305 { 3, "Missing Well-known Attribute"},
306 { 4, "Attribute Flags Error"},
307 { 5, "Attribute Length Error"},
308 { 6, "Invalid ORIGIN Attribute"},
309 { 7, "AS Routing Loop"},
310 { 8, "Invalid NEXT_HOP Attribute"},
311 { 9, "Optional Attribute Error"},
312 { 10, "Invalid Network Field"},
313 { 11, "Malformed AS_PATH"},
314 { 0, NULL}
315 };
316
317 static const struct tok bgp_notify_minor_fsm_values[] = {
318 { 0, "Unspecified Error"},
319 { 1, "In OpenSent State"},
320 { 2, "In OpenConfirm State"},
321 { 3, "In Established State"},
322 { 0, NULL }
323 };
324
325 static const struct tok bgp_notify_minor_cap_values[] = {
326 { 1, "Invalid Action Value" },
327 { 2, "Invalid Capability Length" },
328 { 3, "Malformed Capability Value" },
329 { 4, "Unsupported Capability Code" },
330 { 0, NULL }
331 };
332
333 static const struct tok bgp_origin_values[] = {
334 { 0, "IGP"},
335 { 1, "EGP"},
336 { 2, "Incomplete"},
337 { 0, NULL}
338 };
339
340 #define BGP_PMSI_TUNNEL_RSVP_P2MP 1
341 #define BGP_PMSI_TUNNEL_LDP_P2MP 2
342 #define BGP_PMSI_TUNNEL_PIM_SSM 3
343 #define BGP_PMSI_TUNNEL_PIM_SM 4
344 #define BGP_PMSI_TUNNEL_PIM_BIDIR 5
345 #define BGP_PMSI_TUNNEL_INGRESS 6
346 #define BGP_PMSI_TUNNEL_LDP_MP2MP 7
347
348 static const struct tok bgp_pmsi_tunnel_values[] = {
349 { BGP_PMSI_TUNNEL_RSVP_P2MP, "RSVP-TE P2MP LSP"},
350 { BGP_PMSI_TUNNEL_LDP_P2MP, "LDP P2MP LSP"},
351 { BGP_PMSI_TUNNEL_PIM_SSM, "PIM-SSM Tree"},
352 { BGP_PMSI_TUNNEL_PIM_SM, "PIM-SM Tree"},
353 { BGP_PMSI_TUNNEL_PIM_BIDIR, "PIM-Bidir Tree"},
354 { BGP_PMSI_TUNNEL_INGRESS, "Ingress Replication"},
355 { BGP_PMSI_TUNNEL_LDP_MP2MP, "LDP MP2MP LSP"},
356 { 0, NULL}
357 };
358
359 static const struct tok bgp_pmsi_flag_values[] = {
360 { 0x01, "Leaf Information required"},
361 { 0, NULL}
362 };
363
364 #define BGP_AIGP_TLV 1
365
366 static const struct tok bgp_aigp_values[] = {
367 { BGP_AIGP_TLV, "AIGP"},
368 { 0, NULL}
369 };
370
371 /* Subsequent address family identifier, RFC2283 section 7 */
372 #define SAFNUM_RES 0
373 #define SAFNUM_UNICAST 1
374 #define SAFNUM_MULTICAST 2
375 #define SAFNUM_UNIMULTICAST 3 /* deprecated now */
376 /* labeled BGP RFC3107 */
377 #define SAFNUM_LABUNICAST 4
378 /* RFC6514 */
379 #define SAFNUM_MULTICAST_VPN 5
380 /* draft-nalawade-kapoor-tunnel-safi */
381 #define SAFNUM_TUNNEL 64
382 /* RFC4761 */
383 #define SAFNUM_VPLS 65
384 /* RFC6037 */
385 #define SAFNUM_MDT 66
386 /* RFC7432 */
387 #define SAFNUM_EVPN 70
388 /* RFC4364 */
389 #define SAFNUM_VPNUNICAST 128
390 /* RFC6513 */
391 #define SAFNUM_VPNMULTICAST 129
392 #define SAFNUM_VPNUNIMULTICAST 130 /* deprecated now */
393 /* RFC4684 */
394 #define SAFNUM_RT_ROUTING_INFO 132
395
396 #define BGP_VPN_RD_LEN 8
397
398 static const struct tok bgp_safi_values[] = {
399 { SAFNUM_RES, "Reserved"},
400 { SAFNUM_UNICAST, "Unicast"},
401 { SAFNUM_MULTICAST, "Multicast"},
402 { SAFNUM_UNIMULTICAST, "Unicast+Multicast"},
403 { SAFNUM_LABUNICAST, "labeled Unicast"},
404 { SAFNUM_TUNNEL, "Tunnel"},
405 { SAFNUM_VPLS, "VPLS"},
406 { SAFNUM_MDT, "MDT"},
407 { SAFNUM_EVPN, "EVPN"},
408 { SAFNUM_VPNUNICAST, "labeled VPN Unicast"},
409 { SAFNUM_VPNMULTICAST, "labeled VPN Multicast"},
410 { SAFNUM_VPNUNIMULTICAST, "labeled VPN Unicast+Multicast"},
411 { SAFNUM_RT_ROUTING_INFO, "Route Target Routing Information"},
412 { SAFNUM_MULTICAST_VPN, "Multicast VPN"},
413 { 0, NULL }
414 };
415
416 /* well-known community */
417 #define BGP_COMMUNITY_NO_EXPORT 0xffffff01
418 #define BGP_COMMUNITY_NO_ADVERT 0xffffff02
419 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED 0xffffff03
420
421 /* Extended community type - RFC 4360 */
422 #define BGP_EXT_COM_RT_0 0x0002 /* Route Target,Format AS(2bytes):AN(4bytes) */
423 #define BGP_EXT_COM_RT_1 0x0102 /* Route Target,Format IP address:AN(2bytes) */
424 #define BGP_EXT_COM_RT_2 0x0202 /* Route Target,Format AN(4bytes):local(2bytes) */
425 #define BGP_EXT_COM_RO_0 0x0003 /* Route Origin,Format AS(2bytes):AN(4bytes) */
426 #define BGP_EXT_COM_RO_1 0x0103 /* Route Origin,Format IP address:AN(2bytes) */
427 #define BGP_EXT_COM_RO_2 0x0203 /* Route Origin,Format AN(4bytes):local(2bytes) */
428 #define BGP_EXT_COM_LINKBAND 0x4004 /* Link Bandwidth,Format AS(2B):Bandwidth(4B) */
429 /* rfc2547 bgp-mpls-vpns */
430 #define BGP_EXT_COM_VPN_ORIGIN 0x0005 /* OSPF Domain ID / VPN of Origin - draft-rosen-vpns-ospf-bgp-mpls */
431 #define BGP_EXT_COM_VPN_ORIGIN2 0x0105 /* duplicate - keep for backwards compatibility */
432 #define BGP_EXT_COM_VPN_ORIGIN3 0x0205 /* duplicate - keep for backwards compatibility */
433 #define BGP_EXT_COM_VPN_ORIGIN4 0x8005 /* duplicate - keep for backwards compatibility */
434
435 #define BGP_EXT_COM_OSPF_RTYPE 0x0306 /* OSPF Route Type,Format Area(4B):RouteType(1B):Options(1B) */
436 #define BGP_EXT_COM_OSPF_RTYPE2 0x8000 /* duplicate - keep for backwards compatibility */
437 #define BGP_EXT_COM_ENCAP 0x030c /* rfc5512 */
438
439 #define BGP_EXT_COM_OSPF_RID 0x0107 /* OSPF Router ID,Format RouterID(4B):Unused(2B) */
440 #define BGP_EXT_COM_OSPF_RID2 0x8001 /* duplicate - keep for backwards compatibility */
441
442 #define BGP_EXT_COM_L2INFO 0x800a /* draft-kompella-ppvpn-l2vpn */
443
444 #define BGP_EXT_COM_SOURCE_AS 0x0009 /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
445 #define BGP_EXT_COM_VRF_RT_IMP 0x010b /* RFC-ietf-l3vpn-2547bis-mcast-bgp-08.txt */
446 #define BGP_EXT_COM_L2VPN_RT_0 0x000a /* L2VPN Identifier,Format AS(2bytes):AN(4bytes) */
447 #define BGP_EXT_COM_L2VPN_RT_1 0xF10a /* L2VPN Identifier,Format IP address:AN(2bytes) */
448
449 /* https://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a00801eb09a.shtml */
450 #define BGP_EXT_COM_EIGRP_GEN 0x8800
451 #define BGP_EXT_COM_EIGRP_METRIC_AS_DELAY 0x8801
452 #define BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW 0x8802
453 #define BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU 0x8803
454 #define BGP_EXT_COM_EIGRP_EXT_REMAS_REMID 0x8804
455 #define BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC 0x8805
456
457 static const struct tok bgp_extd_comm_flag_values[] = {
458 { 0x8000, "vendor-specific"},
459 { 0x4000, "non-transitive"},
460 { 0, NULL},
461 };
462
463 static const struct tok bgp_extd_comm_subtype_values[] = {
464 { BGP_EXT_COM_RT_0, "target"},
465 { BGP_EXT_COM_RT_1, "target"},
466 { BGP_EXT_COM_RT_2, "target"},
467 { BGP_EXT_COM_RO_0, "origin"},
468 { BGP_EXT_COM_RO_1, "origin"},
469 { BGP_EXT_COM_RO_2, "origin"},
470 { BGP_EXT_COM_LINKBAND, "link-BW"},
471 { BGP_EXT_COM_VPN_ORIGIN, "ospf-domain"},
472 { BGP_EXT_COM_VPN_ORIGIN2, "ospf-domain"},
473 { BGP_EXT_COM_VPN_ORIGIN3, "ospf-domain"},
474 { BGP_EXT_COM_VPN_ORIGIN4, "ospf-domain"},
475 { BGP_EXT_COM_OSPF_RTYPE, "ospf-route-type"},
476 { BGP_EXT_COM_OSPF_RTYPE2, "ospf-route-type"},
477 { BGP_EXT_COM_ENCAP, "encapsulation"},
478 { BGP_EXT_COM_OSPF_RID, "ospf-router-id"},
479 { BGP_EXT_COM_OSPF_RID2, "ospf-router-id"},
480 { BGP_EXT_COM_L2INFO, "layer2-info"},
481 { BGP_EXT_COM_EIGRP_GEN, "eigrp-general-route (flag, tag)" },
482 { BGP_EXT_COM_EIGRP_METRIC_AS_DELAY, "eigrp-route-metric (AS, delay)" },
483 { BGP_EXT_COM_EIGRP_METRIC_REL_NH_BW, "eigrp-route-metric (reliability, nexthop, bandwidth)" },
484 { BGP_EXT_COM_EIGRP_METRIC_LOAD_MTU, "eigrp-route-metric (load, MTU)" },
485 { BGP_EXT_COM_EIGRP_EXT_REMAS_REMID, "eigrp-external-route (remote-AS, remote-ID)" },
486 { BGP_EXT_COM_EIGRP_EXT_REMPROTO_REMMETRIC, "eigrp-external-route (remote-proto, remote-metric)" },
487 { BGP_EXT_COM_SOURCE_AS, "source-AS" },
488 { BGP_EXT_COM_VRF_RT_IMP, "vrf-route-import"},
489 { BGP_EXT_COM_L2VPN_RT_0, "l2vpn-id"},
490 { BGP_EXT_COM_L2VPN_RT_1, "l2vpn-id"},
491 { 0, NULL},
492 };
493
494 /* RFC RFC5512 BGP Tunnel Encapsulation Attribute Tunnel Types */
495 #define BGP_ENCAP_TUNNEL_L2TPV3_IP 1
496 #define BGP_ENCAP_TUNNEL_GRE 2
497 #define BGP_ENCAP_TUNNEL_TRANSMIT 3
498 #define BGP_ENCAP_TUNNEL_IPSEC 4
499 #define BGP_ENCAP_TUNNEL_IP_IPSEC 5
500 #define BGP_ENCAP_TUNNEL_MPLS_IP 6
501 #define BGP_ENCAP_TUNNEL_IP_IP 7
502 #define BGP_ENCAP_TUNNEL_VXLAN 8
503 #define BGP_ENCAP_TUNNEL_NVGRE 9
504 #define BGP_ENCAP_TUNNEL_MPLS 10
505 #define BGP_ENCAP_TUNNEL_MPLS_GRE 11
506 #define BGP_ENCAP_TUNNEL_VXLAN_GPE 12
507 #define BGP_ENCAP_TUNNEL_MPLS_UDP 13
508 #define BGP_ENCAP_TUNNEL_IPV6 14
509 #define BGP_ENCAP_TUNNEL_SR_TE 15
510 #define BGP_ENCAP_TUNNEL_BARE 16
511 #define BGP_ENCAP_TUNNEL_SR 17
512
513 static const struct tok bgp_extd_comm_encap_tunnel_values[] = {
514 { BGP_ENCAP_TUNNEL_L2TPV3_IP, "L2TPv3 over IP"},
515 { BGP_ENCAP_TUNNEL_GRE, "GRE"},
516 { BGP_ENCAP_TUNNEL_TRANSMIT, "Transmit Tunnel"},
517 { BGP_ENCAP_TUNNEL_IPSEC, "IPsec"},
518 { BGP_ENCAP_TUNNEL_IP_IPSEC, "IP in IP with IPsec"},
519 { BGP_ENCAP_TUNNEL_MPLS_IP, "MPLS in IP with IPsec"},
520 { BGP_ENCAP_TUNNEL_IP_IP, "IP in IP"},
521 { BGP_ENCAP_TUNNEL_VXLAN, "VXLAN"},
522 { BGP_ENCAP_TUNNEL_NVGRE, "NVGRE"},
523 { BGP_ENCAP_TUNNEL_MPLS, "MPLS"},
524 { BGP_ENCAP_TUNNEL_MPLS_GRE, "MPLS in GRE"},
525 { BGP_ENCAP_TUNNEL_VXLAN_GPE, "VXLAN GPE"},
526 { BGP_ENCAP_TUNNEL_MPLS_UDP, "MPLS in UDP"},
527 { BGP_ENCAP_TUNNEL_IPV6, "IPv6"},
528 { BGP_ENCAP_TUNNEL_SR_TE, "SR TE"},
529 { BGP_ENCAP_TUNNEL_BARE, "Bare"},
530 { BGP_ENCAP_TUNNEL_SR, "SR"},
531 { 0, NULL},
532 };
533
534 /* OSPF codes for BGP_EXT_COM_OSPF_RTYPE draft-rosen-vpns-ospf-bgp-mpls */
535 #define BGP_OSPF_RTYPE_RTR 1 /* OSPF Router LSA */
536 #define BGP_OSPF_RTYPE_NET 2 /* OSPF Network LSA */
537 #define BGP_OSPF_RTYPE_SUM 3 /* OSPF Summary LSA */
538 #define BGP_OSPF_RTYPE_EXT 5 /* OSPF External LSA, note that ASBR doesn't apply to MPLS-VPN */
539 #define BGP_OSPF_RTYPE_NSSA 7 /* OSPF NSSA External*/
540 #define BGP_OSPF_RTYPE_SHAM 129 /* OSPF-MPLS-VPN Sham link */
541 #define BGP_OSPF_RTYPE_METRIC_TYPE 0x1 /* LSB of RTYPE Options Field */
542
543 static const struct tok bgp_extd_comm_ospf_rtype_values[] = {
544 { BGP_OSPF_RTYPE_RTR, "Router" },
545 { BGP_OSPF_RTYPE_NET, "Network" },
546 { BGP_OSPF_RTYPE_SUM, "Summary" },
547 { BGP_OSPF_RTYPE_EXT, "External" },
548 { BGP_OSPF_RTYPE_NSSA,"NSSA External" },
549 { BGP_OSPF_RTYPE_SHAM,"MPLS-VPN Sham" },
550 { 0, NULL },
551 };
552
553 /* ADD-PATH Send/Receive field values */
554 static const struct tok bgp_add_path_recvsend[] = {
555 { 1, "Receive" },
556 { 2, "Send" },
557 { 3, "Both" },
558 { 0, NULL },
559 };
560
561 #define AS_STR_SIZE sizeof("xxxxx.xxxxx")
562
563 /*
564 * as_printf
565 *
566 * Convert an AS number into a string and return string pointer.
567 *
568 * Depending on bflag is set or not, AS number is converted into ASDOT notation
569 * or plain number notation.
570 *
571 */
572 static char *
as_printf(netdissect_options * ndo,char * str,size_t size,u_int asnum)573 as_printf(netdissect_options *ndo,
574 char *str, size_t size, u_int asnum)
575 {
576 if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
577 snprintf(str, size, "%u", asnum);
578 } else {
579 snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
580 }
581 return str;
582 }
583
584 #define ITEMCHECK(minlen) if (itemlen < minlen) goto badtlv;
585
586 int
decode_prefix4(netdissect_options * ndo,const u_char * pptr,u_int itemlen,char * buf,size_t buflen)587 decode_prefix4(netdissect_options *ndo,
588 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
589 {
590 nd_ipv4 addr;
591 u_int plen, plenbytes;
592
593 ITEMCHECK(1);
594 plen = GET_U_1(pptr);
595 if (32 < plen)
596 return -1;
597 itemlen -= 1;
598
599 memset(&addr, 0, sizeof(addr));
600 plenbytes = (plen + 7) / 8;
601 ITEMCHECK(plenbytes);
602 GET_CPY_BYTES(&addr, pptr + 1, plenbytes);
603 if (plen % 8) {
604 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
605 }
606 snprintf(buf, buflen, "%s/%u", ipaddr_string(ndo, (const u_char *)&addr), plen);
607 return 1 + plenbytes;
608
609 badtlv:
610 return -2;
611 }
612
613 static int
decode_labeled_prefix4(netdissect_options * ndo,const u_char * pptr,u_int itemlen,char * buf,size_t buflen)614 decode_labeled_prefix4(netdissect_options *ndo,
615 const u_char *pptr, u_int itemlen, char *buf,
616 size_t buflen)
617 {
618 nd_ipv4 addr;
619 u_int plen, plenbytes;
620
621 /* prefix length and label = 4 bytes */
622 ND_TCHECK_4(pptr);
623 ITEMCHECK(4);
624 plen = GET_U_1(pptr); /* get prefix length */
625
626 /* this is one of the weirdnesses of rfc3107
627 the label length (actually the label + COS bits)
628 is added to the prefix length;
629 we also do only read out just one label -
630 there is no real application for advertisement of
631 stacked labels in a single BGP message
632 */
633
634 if (24 > plen)
635 return -1;
636
637 plen-=24; /* adjust prefixlen - labellength */
638
639 if (32 < plen)
640 return -1;
641 itemlen -= 4;
642
643 memset(&addr, 0, sizeof(addr));
644 plenbytes = (plen + 7) / 8;
645 ITEMCHECK(plenbytes);
646 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
647 if (plen % 8) {
648 ((u_char *)&addr)[plenbytes - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
649 }
650 /* the label may get offsetted by 4 bits so lets shift it right */
651 snprintf(buf, buflen, "%s/%u, label:%u %s",
652 ipaddr_string(ndo, (const u_char *)&addr),
653 plen,
654 GET_BE_U_3(pptr + 1)>>4,
655 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
656
657 return 4 + plenbytes;
658
659 trunc:
660 return -2;
661
662 badtlv:
663 return -3;
664 }
665
666 /*
667 * bgp_vpn_ip_print
668 *
669 * print an ipv4 or ipv6 address into a buffer dependent on address length.
670 */
671 static char *
bgp_vpn_ip_print(netdissect_options * ndo,const u_char * pptr,u_int addr_length)672 bgp_vpn_ip_print(netdissect_options *ndo,
673 const u_char *pptr, u_int addr_length)
674 {
675
676 /* worst case string is s fully formatted v6 address */
677 static char addr[sizeof("1234:5678:89ab:cdef:1234:5678:89ab:cdef")];
678 char *pos = addr;
679
680 switch(addr_length) {
681 case (sizeof(nd_ipv4) << 3): /* 32 */
682 snprintf(pos, sizeof(addr), "%s", GET_IPADDR_STRING(pptr));
683 break;
684 case (sizeof(nd_ipv6) << 3): /* 128 */
685 snprintf(pos, sizeof(addr), "%s", GET_IP6ADDR_STRING(pptr));
686 break;
687 default:
688 snprintf(pos, sizeof(addr), "bogus address length %u", addr_length);
689 break;
690 }
691 pos += strlen(pos);
692
693 *(pos) = '\0';
694 return (addr);
695 }
696
697 /*
698 * bgp_vpn_sg_print
699 *
700 * print an multicast s,g entry into a buffer.
701 * the s,g entry is encoded like this.
702 *
703 * +-----------------------------------+
704 * | Multicast Source Length (1 octet) |
705 * +-----------------------------------+
706 * | Multicast Source (Variable) |
707 * +-----------------------------------+
708 * | Multicast Group Length (1 octet) |
709 * +-----------------------------------+
710 * | Multicast Group (Variable) |
711 * +-----------------------------------+
712 *
713 * return the number of bytes read from the wire.
714 */
715 static u_int
bgp_vpn_sg_print(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)716 bgp_vpn_sg_print(netdissect_options *ndo,
717 const u_char *pptr, char *buf, size_t buflen)
718 {
719 uint8_t addr_length;
720 u_int total_length, offset;
721
722 total_length = 0;
723
724 /* Source address length, encoded in bits */
725 addr_length = GET_U_1(pptr);
726 pptr++;
727
728 /* Source address */
729 ND_TCHECK_LEN(pptr, (addr_length >> 3));
730 total_length += (addr_length >> 3) + 1;
731 offset = (u_int)strlen(buf);
732 if (addr_length) {
733 snprintf(buf + offset, buflen - offset, ", Source %s",
734 bgp_vpn_ip_print(ndo, pptr, addr_length));
735 pptr += (addr_length >> 3);
736 }
737
738 /* Group address length, encoded in bits */
739 addr_length = GET_U_1(pptr);
740 pptr++;
741
742 /* Group address */
743 ND_TCHECK_LEN(pptr, (addr_length >> 3));
744 total_length += (addr_length >> 3) + 1;
745 offset = (u_int)strlen(buf);
746 if (addr_length) {
747 snprintf(buf + offset, buflen - offset, ", Group %s",
748 bgp_vpn_ip_print(ndo, pptr, addr_length));
749 pptr += (addr_length >> 3);
750 }
751
752 trunc:
753 return (total_length);
754 }
755
756 /* Print an RFC 4364 Route Distinguisher */
757 const char *
bgp_vpn_rd_print(netdissect_options * ndo,const u_char * pptr)758 bgp_vpn_rd_print(netdissect_options *ndo,
759 const u_char *pptr)
760 {
761 /* allocate space for the largest possible string */
762 static char rd[sizeof("xxxxx.xxxxx:xxxxx (xxx.xxx.xxx.xxx:xxxxx)")];
763 char *pos = rd;
764 /* allocate space for the largest possible string */
765 char astostr[AS_STR_SIZE];
766
767 /* ok lets load the RD format */
768 switch (GET_BE_U_2(pptr)) {
769
770 case 0:
771 /* 2-byte-AS:number fmt */
772 snprintf(pos, sizeof(rd) - (pos - rd), "%u:%u (= %u.%u.%u.%u)",
773 GET_BE_U_2(pptr + 2),
774 GET_BE_U_4(pptr + 4),
775 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
776 GET_U_1(pptr + 6), GET_U_1(pptr + 7));
777 break;
778
779 case 1:
780 /* IP-address:AS fmt */
781 snprintf(pos, sizeof(rd) - (pos - rd), "%u.%u.%u.%u:%u",
782 GET_U_1(pptr + 2), GET_U_1(pptr + 3),
783 GET_U_1(pptr + 4), GET_U_1(pptr + 5),
784 GET_BE_U_2(pptr + 6));
785 break;
786
787 case 2:
788 /* 4-byte-AS:number fmt */
789 snprintf(pos, sizeof(rd) - (pos - rd), "%s:%u (%u.%u.%u.%u:%u)",
790 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 2)),
791 GET_BE_U_2(pptr + 6), GET_U_1(pptr + 2),
792 GET_U_1(pptr + 3), GET_U_1(pptr + 4),
793 GET_U_1(pptr + 5), GET_BE_U_2(pptr + 6));
794 break;
795 default:
796 snprintf(pos, sizeof(rd) - (pos - rd), "unknown RD format");
797 break;
798 }
799 pos += strlen(pos);
800 *(pos) = '\0';
801 return (rd);
802 }
803
804 /*
805 * Print an RFC 4360 Extended Community.
806 */
807 static void
bgp_extended_community_print(netdissect_options * ndo,const u_char * pptr)808 bgp_extended_community_print(netdissect_options *ndo,
809 const u_char *pptr)
810 {
811 union { /* copy buffer for bandwidth values */
812 float f;
813 uint32_t i;
814 } bw;
815 /* allocate space for the largest possible string */
816 char astostr[AS_STR_SIZE];
817
818 switch (GET_BE_U_2(pptr)) {
819
820 case BGP_EXT_COM_RT_0:
821 case BGP_EXT_COM_RO_0:
822 case BGP_EXT_COM_L2VPN_RT_0:
823 ND_PRINT("%u:%u (= %s)",
824 GET_BE_U_2(pptr + 2),
825 GET_BE_U_4(pptr + 4),
826 GET_IPADDR_STRING(pptr+4));
827 break;
828
829 case BGP_EXT_COM_RT_1:
830 case BGP_EXT_COM_RO_1:
831 case BGP_EXT_COM_L2VPN_RT_1:
832 case BGP_EXT_COM_VRF_RT_IMP:
833 ND_PRINT("%s:%u",
834 GET_IPADDR_STRING(pptr+2),
835 GET_BE_U_2(pptr + 6));
836 break;
837
838 case BGP_EXT_COM_RT_2:
839 case BGP_EXT_COM_RO_2:
840 ND_PRINT("%s:%u",
841 as_printf(ndo, astostr, sizeof(astostr),
842 GET_BE_U_4(pptr + 2)), GET_BE_U_2(pptr + 6));
843 break;
844
845 case BGP_EXT_COM_LINKBAND:
846 bw.i = GET_BE_U_4(pptr + 4);
847 ND_PRINT("bandwidth: %.3f Mbps",
848 bw.f*8/1000000);
849 break;
850
851 case BGP_EXT_COM_VPN_ORIGIN:
852 case BGP_EXT_COM_VPN_ORIGIN2:
853 case BGP_EXT_COM_VPN_ORIGIN3:
854 case BGP_EXT_COM_VPN_ORIGIN4:
855 case BGP_EXT_COM_OSPF_RID:
856 case BGP_EXT_COM_OSPF_RID2:
857 ND_PRINT("%s", GET_IPADDR_STRING(pptr+2));
858 break;
859
860 case BGP_EXT_COM_OSPF_RTYPE:
861 case BGP_EXT_COM_OSPF_RTYPE2:
862 ND_PRINT("area:%s, router-type:%s, metric-type:%s%s",
863 GET_IPADDR_STRING(pptr+2),
864 tok2str(bgp_extd_comm_ospf_rtype_values,
865 "unknown (0x%02x)",
866 GET_U_1((pptr + 6))),
867 (GET_U_1(pptr + 7) & BGP_OSPF_RTYPE_METRIC_TYPE) ? "E2" : "",
868 ((GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_EXT) || (GET_U_1(pptr + 6) == BGP_OSPF_RTYPE_NSSA)) ? "E1" : "");
869 break;
870
871 case BGP_EXT_COM_L2INFO:
872 ND_PRINT("%s Control Flags [0x%02x]:MTU %u",
873 tok2str(l2vpn_encaps_values,
874 "unknown encaps",
875 GET_U_1((pptr + 2))),
876 GET_U_1((pptr + 3)),
877 GET_BE_U_2(pptr + 4));
878 break;
879
880 case BGP_EXT_COM_SOURCE_AS:
881 ND_PRINT("AS %u", GET_BE_U_2(pptr + 2));
882 break;
883
884 case BGP_EXT_COM_ENCAP:
885 ND_PRINT("Tunnel type: %s", tok2str(bgp_extd_comm_encap_tunnel_values,
886 "unknown encaps",
887 GET_BE_U_2(pptr + 6)));
888 break;
889
890 default:
891 ND_PRINT("%02x%02x%02x%02x%02x%02x",
892 GET_U_1(pptr + 2),
893 GET_U_1(pptr + 3),
894 GET_U_1(pptr + 4),
895 GET_U_1(pptr + 5),
896 GET_U_1(pptr + 6),
897 GET_U_1(pptr + 7));
898 break;
899 }
900 }
901
902 /*
903 * RFC4684 (Section 4)/RFC2858 (Section 4).
904 * RTC membership prefix is structured as follows
905 * [prefix-len] [origin-as] [route-target]
906 * The route-target is encoded as RT ext-comms.
907 * Prefix-len may be 0, 32..96
908 *
909 * Note that pptr is not packet data - it is
910 * a buffer owned by our caller - therefore GET_*
911 * macros can not be used.
912 */
913 static char *
bgp_rt_prefix_print(netdissect_options * ndo,const u_char * pptr,u_int plen)914 bgp_rt_prefix_print(netdissect_options *ndo,
915 const u_char *pptr,
916 u_int plen)
917 {
918 /* allocate space for the largest possible string */
919 char rtc_prefix_in_hex[sizeof("0000 0000 0000 0000")] = "";
920 u_int rtc_prefix_in_hex_len = 0;
921 static char output[61]; /* max response string */
922 /* allocate space for the largest possible string */
923 char astostr[AS_STR_SIZE];
924 uint16_t ec_type = 0;
925 u_int octet_count;
926 u_int i;
927
928 if (plen == 0) {
929 snprintf(output, sizeof(output), "route-target: 0:0/0");
930 return (output);
931 }
932
933 /* hex representation of the prefix */
934 octet_count = (plen+7)/8;
935 for (i=0; i<octet_count; i++) {
936 rtc_prefix_in_hex_len += snprintf(rtc_prefix_in_hex+rtc_prefix_in_hex_len,
937 sizeof(rtc_prefix_in_hex)-rtc_prefix_in_hex_len,
938 "%02x%s", *(pptr+i),
939 ((i%2 == 1) && (i<octet_count-1)) ? " " : "");
940 }
941
942 if (plen < 16) {
943 /*
944 * The prefix is too short to include the full ext-comm type,
945 * so we have no way to parse it further.
946 */
947 snprintf(output, sizeof(output), "route-target: partial-type: (%s/%d)",
948 rtc_prefix_in_hex, plen);
949 return (output);
950 }
951
952 /*
953 * get the ext-comm type
954 * Note: pptr references a static 8 octet buffer with unused bits set to 0,
955 * hence EXTRACT_*() macros are safe.
956 */
957 ec_type = EXTRACT_BE_U_2(pptr);
958 switch (ec_type) {
959 case BGP_EXT_COM_RT_0:
960 /* 2-byte-AS:number fmt */
961 snprintf(output, sizeof(output), "route-target: %u:%u/%d (%s)",
962 EXTRACT_BE_U_2(pptr+2),
963 EXTRACT_BE_U_4(pptr+4),
964 plen, rtc_prefix_in_hex);
965 break;
966
967 case BGP_EXT_COM_RT_1:
968 /* IP-address:AS fmt */
969 snprintf(output, sizeof(output), "route-target: %u.%u.%u.%u:%u/%d (%s)",
970 *(pptr+2), *(pptr+3), *(pptr+4), *(pptr+5),
971 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
972 break;
973
974 case BGP_EXT_COM_RT_2:
975 /* 4-byte-AS:number fmt */
976 snprintf(output, sizeof(output), "route-target: %s:%u/%d (%s)",
977 as_printf(ndo, astostr, sizeof(astostr), EXTRACT_BE_U_4(pptr+2)),
978 EXTRACT_BE_U_2(pptr+6), plen, rtc_prefix_in_hex);
979 break;
980
981 default:
982 snprintf(output, sizeof(output), "route target: unknown-type(%04x) (%s/%d)",
983 ec_type,
984 rtc_prefix_in_hex, plen);
985 break;
986 }
987 return (output);
988 }
989
990 /* RFC 4684 */
991 static int
decode_rt_routing_info(netdissect_options * ndo,const u_char * pptr)992 decode_rt_routing_info(netdissect_options *ndo,
993 const u_char *pptr)
994 {
995 uint8_t route_target[8];
996 u_int plen;
997 /* allocate space for the largest possible string */
998 char astostr[AS_STR_SIZE];
999 u_int num_octets;
1000
1001 /* NLRI "prefix length" from RFC 2858 Section 4. */
1002 plen = GET_U_1(pptr); /* get prefix length */
1003
1004 /* NLRI "prefix" (ibid), valid lengths are { 0, 32, 33, ..., 96 } bits.
1005 * RFC 4684 Section 4 defines the layout of "origin AS" and "route
1006 * target" fields inside the "prefix" depending on its length.
1007 */
1008 if (0 == plen) {
1009 /* Without "origin AS", without "route target". */
1010 ND_PRINT("\n\t default route target");
1011 return 1;
1012 }
1013
1014 if (32 > plen) {
1015 ND_PRINT("\n\t (illegal prefix length)");
1016 return -1;
1017 }
1018
1019 /* With at least "origin AS", possibly with "route target". */
1020 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(pptr + 1));
1021
1022 plen -= 32; /* adjust prefix length */
1023
1024 if (64 < plen) {
1025 ND_PRINT("\n\t (illegal prefix length)");
1026 return -1;
1027 }
1028
1029 /* From now on (plen + 7) / 8 evaluates to { 0, 1, 2, ..., 8 }
1030 * and gives the number of octets in the variable-length "route
1031 * target" field inside this NLRI "prefix". Look for it.
1032 */
1033 memset(&route_target, 0, sizeof(route_target));
1034 num_octets = (plen + 7) / 8;
1035 GET_CPY_BYTES(&route_target, pptr + 5, num_octets);
1036 /* If mask-len is not on octet boundary, ensure all extra bits are 0 */
1037 if (plen % 8) {
1038 ((u_char *)&route_target)[num_octets - 1] &=
1039 ((0xff00 >> (plen % 8)) & 0xff);
1040 }
1041 ND_PRINT("\n\t origin AS: %s, %s",
1042 astostr,
1043 bgp_rt_prefix_print(ndo, (u_char *)&route_target, plen));
1044
1045 return 5 + num_octets;
1046 }
1047
1048 static int
decode_labeled_vpn_prefix4(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1049 decode_labeled_vpn_prefix4(netdissect_options *ndo,
1050 const u_char *pptr, char *buf, size_t buflen)
1051 {
1052 nd_ipv4 addr;
1053 u_int plen;
1054
1055 plen = GET_U_1(pptr); /* get prefix length */
1056
1057 if ((24+64) > plen)
1058 return -1;
1059
1060 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1061
1062 if (32 < plen)
1063 return -1;
1064
1065 memset(&addr, 0, sizeof(addr));
1066 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1067 if (plen % 8) {
1068 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
1069 ((0xff00 >> (plen % 8)) & 0xff);
1070 }
1071 /* the label may get offsetted by 4 bits so lets shift it right */
1072 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1073 bgp_vpn_rd_print(ndo, pptr+4),
1074 ipaddr_string(ndo, (const u_char *)&addr),
1075 plen,
1076 GET_BE_U_3(pptr + 1)>>4,
1077 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1078
1079 return 12 + (plen + 7) / 8;
1080 }
1081
1082 /*
1083 * +-------------------------------+
1084 * | |
1085 * | RD:IPv4-address (12 octets) |
1086 * | |
1087 * +-------------------------------+
1088 * | MDT Group-address (4 octets) |
1089 * +-------------------------------+
1090 */
1091
1092 #define MDT_VPN_NLRI_LEN 16
1093
1094 static int
decode_mdt_vpn_nlri(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1095 decode_mdt_vpn_nlri(netdissect_options *ndo,
1096 const u_char *pptr, char *buf, size_t buflen)
1097 {
1098 const u_char *rd;
1099 const u_char *vpn_ip;
1100
1101 /* if the NLRI is not predefined length, quit.*/
1102 if (GET_U_1(pptr) != MDT_VPN_NLRI_LEN * 8)
1103 return -1;
1104 pptr++;
1105
1106 /* RD */
1107 ND_TCHECK_8(pptr);
1108 rd = pptr;
1109 pptr += 8;
1110
1111 /* IPv4 address */
1112 vpn_ip = pptr;
1113 pptr += sizeof(nd_ipv4);
1114
1115 /* MDT Group Address */
1116 snprintf(buf, buflen, "RD: %s, VPN IP Address: %s, MC Group Address: %s",
1117 bgp_vpn_rd_print(ndo, rd), GET_IPADDR_STRING(vpn_ip), GET_IPADDR_STRING(pptr));
1118
1119 return MDT_VPN_NLRI_LEN + 1;
1120
1121 trunc:
1122 return -2;
1123 }
1124
1125 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI 1
1126 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI 2
1127 #define BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI 3
1128 #define BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF 4
1129 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE 5
1130 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN 6
1131 #define BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN 7
1132
1133 static const struct tok bgp_multicast_vpn_route_type_values[] = {
1134 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI, "Intra-AS I-PMSI"},
1135 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI, "Inter-AS I-PMSI"},
1136 { BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI, "S-PMSI"},
1137 { BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF, "Intra-AS Segment-Leaf"},
1138 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE, "Source-Active"},
1139 { BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN, "Shared Tree Join"},
1140 { BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN, "Source Tree Join"},
1141 { 0, NULL}
1142 };
1143
1144 UNALIGNED_OK
1145 static int
decode_multicast_vpn(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1146 decode_multicast_vpn(netdissect_options *ndo,
1147 const u_char *pptr, char *buf, size_t buflen)
1148 {
1149 /* allocate space for the largest possible string */
1150 char astostr[AS_STR_SIZE];
1151 uint8_t route_type, route_length;
1152 u_int addr_length, sg_length;
1153 u_int offset;
1154
1155 route_type = GET_U_1(pptr);
1156 pptr++;
1157 route_length = GET_U_1(pptr);
1158 pptr++;
1159
1160 snprintf(buf, buflen, "Route-Type: %s (%u), length: %u",
1161 tok2str(bgp_multicast_vpn_route_type_values,
1162 "Unknown", route_type),
1163 route_type, route_length);
1164
1165 switch(route_type) {
1166 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_I_PMSI:
1167 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1168 if (route_length < BGP_VPN_RD_LEN)
1169 goto trunc;
1170 offset = (u_int)strlen(buf);
1171 snprintf(buf + offset, buflen - offset, ", RD: %s, Originator %s",
1172 bgp_vpn_rd_print(ndo, pptr),
1173 bgp_vpn_ip_print(ndo, pptr + BGP_VPN_RD_LEN,
1174 (route_length - BGP_VPN_RD_LEN) << 3));
1175 break;
1176 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTER_AS_I_PMSI:
1177 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1178 offset = (u_int)strlen(buf);
1179 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1180 bgp_vpn_rd_print(ndo, pptr),
1181 as_printf(ndo, astostr, sizeof(astostr),
1182 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1183 break;
1184
1185 case BGP_MULTICAST_VPN_ROUTE_TYPE_S_PMSI:
1186 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1187 offset = (u_int)strlen(buf);
1188 snprintf(buf + offset, buflen - offset, ", RD: %s",
1189 bgp_vpn_rd_print(ndo, pptr));
1190 pptr += BGP_VPN_RD_LEN;
1191
1192 sg_length = bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1193 addr_length = route_length - sg_length;
1194
1195 ND_TCHECK_LEN(pptr, addr_length);
1196 offset = (u_int)strlen(buf);
1197 snprintf(buf + offset, buflen - offset, ", Originator %s",
1198 bgp_vpn_ip_print(ndo, pptr, addr_length << 3));
1199 break;
1200
1201 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_ACTIVE:
1202 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN);
1203 offset = (u_int)strlen(buf);
1204 snprintf(buf + offset, buflen - offset, ", RD: %s",
1205 bgp_vpn_rd_print(ndo, pptr));
1206 pptr += BGP_VPN_RD_LEN;
1207
1208 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1209 break;
1210
1211 case BGP_MULTICAST_VPN_ROUTE_TYPE_SHARED_TREE_JOIN: /* fall through */
1212 case BGP_MULTICAST_VPN_ROUTE_TYPE_SOURCE_TREE_JOIN:
1213 ND_TCHECK_LEN(pptr, BGP_VPN_RD_LEN + 4);
1214 offset = (u_int)strlen(buf);
1215 snprintf(buf + offset, buflen - offset, ", RD: %s, Source-AS %s",
1216 bgp_vpn_rd_print(ndo, pptr),
1217 as_printf(ndo, astostr, sizeof(astostr),
1218 GET_BE_U_4(pptr + BGP_VPN_RD_LEN)));
1219 pptr += BGP_VPN_RD_LEN + 4;
1220
1221 bgp_vpn_sg_print(ndo, pptr, buf, buflen);
1222 break;
1223
1224 /*
1225 * no per route-type printing yet.
1226 */
1227 case BGP_MULTICAST_VPN_ROUTE_TYPE_INTRA_AS_SEG_LEAF:
1228 default:
1229 break;
1230 }
1231
1232 return route_length + 2;
1233
1234 trunc:
1235 return -2;
1236 }
1237
1238 /*
1239 * As I remember, some versions of systems have an snprintf() that
1240 * returns -1 if the buffer would have overflowed. If the return
1241 * value is negative, set buflen to 0, to indicate that we've filled
1242 * the buffer up.
1243 *
1244 * If the return value is greater than buflen, that means that
1245 * the buffer would have overflowed; again, set buflen to 0 in
1246 * that case.
1247 */
1248 #define UPDATE_BUF_BUFLEN(buf, buflen, stringlen) \
1249 if (stringlen<0) \
1250 buflen=0; \
1251 else if ((u_int)stringlen>buflen) \
1252 buflen=0; \
1253 else { \
1254 buflen-=stringlen; \
1255 buf+=stringlen; \
1256 }
1257
1258 static int
decode_labeled_vpn_l2(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1259 decode_labeled_vpn_l2(netdissect_options *ndo,
1260 const u_char *pptr, char *buf, size_t buflen)
1261 {
1262 u_int plen, tlen, tlv_type, tlv_len, ttlv_len;
1263 int stringlen;
1264
1265 plen = GET_BE_U_2(pptr);
1266 tlen = plen;
1267 pptr += 2;
1268 /* Old and new L2VPN NLRI share AFI/SAFI
1269 * -> Assume a 12 Byte-length NLRI is auto-discovery-only
1270 * and > 17 as old format. Complain for the middle case
1271 */
1272 if (plen == 12) {
1273 /* assume AD-only with RD, BGPNH */
1274 ND_TCHECK_LEN(pptr, 12);
1275 buf[0] = '\0';
1276 stringlen = snprintf(buf, buflen, "RD: %s, BGPNH: %s",
1277 bgp_vpn_rd_print(ndo, pptr),
1278 GET_IPADDR_STRING(pptr+8));
1279 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1280 pptr += 12;
1281 tlen -= 12;
1282 return plen + 2;
1283 } else if (plen > 17) {
1284 /* assume old format */
1285 /* RD, ID, LBLKOFF, LBLBASE */
1286
1287 ND_TCHECK_LEN(pptr, 15);
1288 buf[0] = '\0';
1289 stringlen = snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
1290 bgp_vpn_rd_print(ndo, pptr),
1291 GET_BE_U_2(pptr + 8),
1292 GET_BE_U_2(pptr + 10),
1293 GET_BE_U_3(pptr + 12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
1294 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1295 pptr += 15;
1296 tlen -= 15;
1297
1298 /* ok now the variable part - lets read out TLVs*/
1299 while (tlen != 0) {
1300 if (tlen < 3) {
1301 if (buflen != 0) {
1302 stringlen=snprintf(buf,buflen, "\n\t\tran past the end");
1303 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1304 }
1305 return plen + 2;
1306 }
1307 tlv_type = GET_U_1(pptr);
1308 pptr++;
1309 tlv_len = GET_BE_U_2(pptr); /* length, in *bits* */
1310 ttlv_len = (tlv_len + 7)/8; /* length, in *bytes* */
1311 pptr += 2;
1312
1313 switch(tlv_type) {
1314 case 1:
1315 if (buflen != 0) {
1316 stringlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
1317 tlv_type,
1318 tlv_len);
1319 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1320 }
1321 while (ttlv_len != 0) {
1322 if (tlen < 1) {
1323 if (buflen != 0) {
1324 stringlen=snprintf(buf,buflen, " (ran past the end)");
1325 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1326 }
1327 return plen + 2;
1328 }
1329 ND_TCHECK_1(pptr);
1330 if (buflen != 0) {
1331 stringlen=snprintf(buf,buflen, "%02x",
1332 GET_U_1(pptr));
1333 pptr++;
1334 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1335 }
1336 ttlv_len--;
1337 tlen--;
1338 }
1339 break;
1340 default:
1341 if (buflen != 0) {
1342 stringlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
1343 tlv_type,
1344 tlv_len);
1345 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1346 }
1347 if (tlen < ttlv_len) {
1348 if (buflen != 0) {
1349 stringlen=snprintf(buf,buflen, " (ran past the end)");
1350 UPDATE_BUF_BUFLEN(buf, buflen, stringlen);
1351 }
1352 return plen + 2;
1353 }
1354 tlen -= ttlv_len;
1355 break;
1356 }
1357 }
1358 return plen + 2;
1359 } else {
1360 /* complain bitterly ? */
1361 /* fall through */
1362 goto trunc;
1363 }
1364
1365 trunc:
1366 return -2;
1367 }
1368
1369 int
decode_prefix6(netdissect_options * ndo,const u_char * pd,u_int itemlen,char * buf,size_t buflen)1370 decode_prefix6(netdissect_options *ndo,
1371 const u_char *pd, u_int itemlen, char *buf, size_t buflen)
1372 {
1373 nd_ipv6 addr;
1374 u_int plen, plenbytes;
1375
1376 ITEMCHECK(1);
1377 plen = GET_U_1(pd);
1378 if (128 < plen)
1379 return -1;
1380 itemlen -= 1;
1381
1382 memset(&addr, 0, sizeof(addr));
1383 plenbytes = (plen + 7) / 8;
1384 ITEMCHECK(plenbytes);
1385 GET_CPY_BYTES(&addr, pd + 1, plenbytes);
1386 if (plen % 8) {
1387 addr[plenbytes - 1] &=
1388 ((0xff00 >> (plen % 8)) & 0xff);
1389 }
1390 snprintf(buf, buflen, "%s/%u", ip6addr_string(ndo, (const u_char *)&addr), plen);
1391 return 1 + plenbytes;
1392
1393 badtlv:
1394 return -2;
1395 }
1396
1397 static int
decode_labeled_prefix6(netdissect_options * ndo,const u_char * pptr,u_int itemlen,char * buf,size_t buflen)1398 decode_labeled_prefix6(netdissect_options *ndo,
1399 const u_char *pptr, u_int itemlen, char *buf, size_t buflen)
1400 {
1401 nd_ipv6 addr;
1402 u_int plen, plenbytes;
1403
1404 /* prefix length and label = 4 bytes */
1405 ND_TCHECK_4(pptr);
1406 ITEMCHECK(4);
1407 plen = GET_U_1(pptr); /* get prefix length */
1408
1409 if (24 > plen)
1410 return -1;
1411
1412 plen -= 24; /* adjust prefixlen - labellength */
1413
1414 if (128 < plen)
1415 return -1;
1416 itemlen -= 4;
1417
1418 memset(&addr, 0, sizeof(addr));
1419 plenbytes = (plen + 7) / 8;
1420 GET_CPY_BYTES(&addr, pptr + 4, plenbytes);
1421 if (plen % 8) {
1422 addr[plenbytes - 1] &=
1423 ((0xff00 >> (plen % 8)) & 0xff);
1424 }
1425 /* the label may get offsetted by 4 bits so lets shift it right */
1426 snprintf(buf, buflen, "%s/%u, label:%u %s",
1427 ip6addr_string(ndo, (const u_char *)&addr),
1428 plen,
1429 GET_BE_U_3(pptr + 1)>>4,
1430 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1431
1432 return 4 + plenbytes;
1433
1434 trunc:
1435 return -2;
1436
1437 badtlv:
1438 return -3;
1439 }
1440
1441 static int
decode_labeled_vpn_prefix6(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1442 decode_labeled_vpn_prefix6(netdissect_options *ndo,
1443 const u_char *pptr, char *buf, size_t buflen)
1444 {
1445 nd_ipv6 addr;
1446 u_int plen;
1447
1448 plen = GET_U_1(pptr); /* get prefix length */
1449
1450 if ((24+64) > plen)
1451 return -1;
1452
1453 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1454
1455 if (128 < plen)
1456 return -1;
1457
1458 memset(&addr, 0, sizeof(addr));
1459 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1460 if (plen % 8) {
1461 addr[(plen + 7) / 8 - 1] &=
1462 ((0xff00 >> (plen % 8)) & 0xff);
1463 }
1464 /* the label may get offsetted by 4 bits so lets shift it right */
1465 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1466 bgp_vpn_rd_print(ndo, pptr+4),
1467 ip6addr_string(ndo, (const u_char *)&addr),
1468 plen,
1469 GET_BE_U_3(pptr + 1)>>4,
1470 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1471
1472 return 12 + (plen + 7) / 8;
1473 }
1474
1475 static int
decode_clnp_prefix(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1476 decode_clnp_prefix(netdissect_options *ndo,
1477 const u_char *pptr, char *buf, size_t buflen)
1478 {
1479 uint8_t addr[19];
1480 u_int plen;
1481
1482 plen = GET_U_1(pptr); /* get prefix length */
1483
1484 if (152 < plen)
1485 return -1;
1486
1487 memset(&addr, 0, sizeof(addr));
1488 GET_CPY_BYTES(&addr, pptr + 4, (plen + 7) / 8);
1489 if (plen % 8) {
1490 addr[(plen + 7) / 8 - 1] &=
1491 ((0xff00 >> (plen % 8)) & 0xff);
1492 }
1493 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1494 snprintf(buf, buflen, "%s/%u",
1495 isonsap_string(ndo, addr,(plen + 7) / 8),
1496 plen);
1497
1498 return 1 + (plen + 7) / 8;
1499 }
1500
1501 static int
decode_labeled_vpn_clnp_prefix(netdissect_options * ndo,const u_char * pptr,char * buf,size_t buflen)1502 decode_labeled_vpn_clnp_prefix(netdissect_options *ndo,
1503 const u_char *pptr, char *buf, size_t buflen)
1504 {
1505 uint8_t addr[19];
1506 u_int plen;
1507
1508 plen = GET_U_1(pptr); /* get prefix length */
1509
1510 if ((24+64) > plen)
1511 return -1;
1512
1513 plen -= (24+64); /* adjust prefixlen - labellength - RD len*/
1514
1515 if (152 < plen)
1516 return -1;
1517
1518 memset(&addr, 0, sizeof(addr));
1519 GET_CPY_BYTES(&addr, pptr + 12, (plen + 7) / 8);
1520 if (plen % 8) {
1521 addr[(plen + 7) / 8 - 1] &= ((0xff00 >> (plen % 8)) & 0xff);
1522 }
1523 /* the label may get offsetted by 4 bits so lets shift it right */
1524 /* Cannot use GET_ISONSAP_STRING (not packet buffer pointer) */
1525 snprintf(buf, buflen, "RD: %s, %s/%u, label:%u %s",
1526 bgp_vpn_rd_print(ndo, pptr+4),
1527 isonsap_string(ndo, addr,(plen + 7) / 8),
1528 plen,
1529 GET_BE_U_3(pptr + 1)>>4,
1530 ((GET_U_1(pptr + 3) & 1) == 0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
1531
1532 return 12 + (plen + 7) / 8;
1533 }
1534
1535 /*
1536 * bgp_attr_get_as_size
1537 *
1538 * Try to find the size of the ASs encoded in an as-path. It is not obvious, as
1539 * both Old speakers that do not support 4 byte AS, and the new speakers that do
1540 * support, exchange AS-Path with the same path-attribute type value 0x02.
1541 */
1542 static u_int
bgp_attr_get_as_size(netdissect_options * ndo,uint8_t bgpa_type,const u_char * pptr,u_int len)1543 bgp_attr_get_as_size(netdissect_options *ndo,
1544 uint8_t bgpa_type, const u_char *pptr, u_int len)
1545 {
1546 const u_char *tptr = pptr;
1547
1548 /*
1549 * If the path attribute is the optional AS4 path type, then we already
1550 * know, that ASs must be encoded in 4 byte format.
1551 */
1552 if (bgpa_type == BGPTYPE_AS4_PATH) {
1553 return 4;
1554 }
1555
1556 /*
1557 * Let us assume that ASs are of 2 bytes in size, and check if the AS-Path
1558 * TLV is good. If not, ask the caller to try with AS encoded as 4 bytes
1559 * each.
1560 */
1561 while (tptr < pptr + len) {
1562 /*
1563 * If we do not find a valid segment type, our guess might be wrong.
1564 */
1565 if (GET_U_1(tptr) < BGP_AS_SEG_TYPE_MIN || GET_U_1(tptr) > BGP_AS_SEG_TYPE_MAX) {
1566 goto trunc;
1567 }
1568 tptr += 2 + GET_U_1(tptr + 1) * 2;
1569 }
1570
1571 /*
1572 * If we correctly reached end of the AS path attribute data content,
1573 * then most likely ASs were indeed encoded as 2 bytes.
1574 */
1575 if (tptr == pptr + len) {
1576 return 2;
1577 }
1578
1579 trunc:
1580
1581 /*
1582 * We can come here, either we did not have enough data, or if we
1583 * try to decode 4 byte ASs in 2 byte format. Either way, return 4,
1584 * so that caller can try to decode each AS as of 4 bytes. If indeed
1585 * there was not enough data, it will crib and end the parse anyways.
1586 */
1587 return 4;
1588 }
1589
1590 /*
1591 * The only way to know that a BGP UPDATE message is using add path is
1592 * by checking if the capability is in the OPEN message which we may have missed.
1593 * So this function checks if it is possible that the update could contain add path
1594 * and if so it checks that standard BGP doesn't make sense.
1595 */
1596 static int
check_add_path(netdissect_options * ndo,const u_char * pptr,u_int length,u_int max_prefix_length)1597 check_add_path(netdissect_options *ndo, const u_char *pptr, u_int length,
1598 u_int max_prefix_length)
1599 {
1600 u_int offset, prefix_length;
1601
1602 if (length < 5) {
1603 return 0;
1604 }
1605
1606 /*
1607 * Scan through the NLRI information under the assumption that
1608 * it doesn't have path IDs.
1609 */
1610 for (offset = 0; offset < length;) {
1611 offset += 4;
1612 if (!ND_TTEST_1(pptr + offset)) {
1613 /* We ran out of captured data; quit scanning. */
1614 break;
1615 }
1616 prefix_length = GET_U_1(pptr + offset);
1617 /*
1618 * Add 4 to cover the path id
1619 * and check the prefix length isn't greater than 32/128.
1620 */
1621 if (prefix_length > max_prefix_length) {
1622 return 0;
1623 }
1624 /* Add 1 for the prefix_length byte and prefix_length to cover the address */
1625 offset += 1 + ((prefix_length + 7) / 8);
1626 }
1627 /* check we haven't gone past the end of the section */
1628 if (offset > length) {
1629 return 0;
1630 }
1631
1632 /* check it's not standard BGP */
1633 for (offset = 0; offset < length; ) {
1634 if (!ND_TTEST_1(pptr + offset)) {
1635 /* We ran out of captured data; quit scanning. */
1636 break;
1637 }
1638 prefix_length = GET_U_1(pptr + offset);
1639 /*
1640 * If the prefix_length is zero (0.0.0.0/0)
1641 * and since it's not the only address (length >= 5)
1642 * then it is add-path
1643 */
1644 if (prefix_length < 1 || prefix_length > max_prefix_length) {
1645 return 1;
1646 }
1647 offset += 1 + ((prefix_length + 7) / 8);
1648 }
1649 if (offset > length) {
1650 return 1;
1651 }
1652
1653 /* assume not add-path by default */
1654 return 0;
1655 }
1656
1657 static int
bgp_mp_af_print(netdissect_options * ndo,const u_char * tptr,u_int tlen,uint16_t * afp,uint8_t * safip)1658 bgp_mp_af_print(netdissect_options *ndo,
1659 const u_char *tptr, u_int tlen,
1660 uint16_t *afp, uint8_t *safip)
1661 {
1662 uint16_t af;
1663 uint8_t safi;
1664
1665 af = GET_BE_U_2(tptr);
1666 *afp = af;
1667 safi = GET_U_1(tptr + 2);
1668 *safip = safi;
1669
1670 ND_PRINT("\n\t AFI: %s (%u), %sSAFI: %s (%u)",
1671 tok2str(af_values, "Unknown AFI", af),
1672 af,
1673 (safi>128) ? "vendor specific " : "", /* 128 is meanwhile wellknown */
1674 tok2str(bgp_safi_values, "Unknown SAFI", safi),
1675 safi);
1676
1677 switch(af<<8 | safi) {
1678 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1679 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1680 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1681 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1682 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1683 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1684 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1685 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1686 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
1687 case (AFNUM_INET<<8 | SAFNUM_MDT):
1688 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1689 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1690 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1691 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1692 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1693 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1694 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1695 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1696 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1697 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1698 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1699 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1700 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1701 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1702 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1703 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1704 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1705 break;
1706 default:
1707 ND_TCHECK_LEN(tptr, tlen);
1708 ND_PRINT("\n\t no AFI %u / SAFI %u decoder", af, safi);
1709 if (ndo->ndo_vflag <= 1)
1710 print_unknown_data(ndo, tptr, "\n\t ", tlen);
1711 return -1;
1712 }
1713 return 0;
1714 trunc:
1715 return -2;
1716 }
1717
1718 static int
bgp_nlri_print(netdissect_options * ndo,uint16_t af,uint8_t safi,const u_char * tptr,u_int len,char * buf,size_t buflen,int add_path4,int add_path6)1719 bgp_nlri_print(netdissect_options *ndo, uint16_t af, uint8_t safi,
1720 const u_char *tptr, u_int len,
1721 char *buf, size_t buflen,
1722 int add_path4, int add_path6)
1723 {
1724 int advance;
1725 u_int path_id = 0;
1726
1727 switch (af<<8 | safi) {
1728 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
1729 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
1730 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
1731 if (add_path4) {
1732 path_id = GET_BE_U_4(tptr);
1733 tptr += 4;
1734 }
1735 advance = decode_prefix4(ndo, tptr, len, buf, buflen);
1736 if (advance == -1)
1737 ND_PRINT("\n\t (illegal prefix length)");
1738 else if (advance == -2)
1739 break; /* bytes left, but not enough */
1740 else
1741 ND_PRINT("\n\t %s", buf);
1742 if (add_path4) {
1743 ND_PRINT(" Path Id: %u", path_id);
1744 advance += 4;
1745 }
1746 break;
1747 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
1748 advance = decode_labeled_prefix4(ndo, tptr, len, buf, buflen);
1749 if (advance == -1)
1750 ND_PRINT("\n\t (illegal prefix length)");
1751 else if (advance == -2)
1752 goto trunc;
1753 else if (advance == -3)
1754 break; /* bytes left, but not enough */
1755 else
1756 ND_PRINT("\n\t %s", buf);
1757 break;
1758 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
1759 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
1760 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
1761 advance = decode_labeled_vpn_prefix4(ndo, tptr, buf, buflen);
1762 if (advance == -1)
1763 ND_PRINT("\n\t (illegal prefix length)");
1764 else
1765 ND_PRINT("\n\t %s", buf);
1766 break;
1767 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
1768 advance = decode_rt_routing_info(ndo, tptr);
1769 break;
1770 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN): /* fall through */
1771 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST_VPN):
1772 advance = decode_multicast_vpn(ndo, tptr, buf, buflen);
1773 if (advance == -1)
1774 ND_PRINT("\n\t (illegal prefix length)");
1775 else if (advance == -2)
1776 goto trunc;
1777 else
1778 ND_PRINT("\n\t %s", buf);
1779 break;
1780
1781 case (AFNUM_INET<<8 | SAFNUM_MDT):
1782 advance = decode_mdt_vpn_nlri(ndo, tptr, buf, buflen);
1783 if (advance == -1)
1784 ND_PRINT("\n\t (illegal prefix length)");
1785 else if (advance == -2)
1786 goto trunc;
1787 else
1788 ND_PRINT("\n\t %s", buf);
1789 break;
1790 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
1791 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
1792 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
1793 if (add_path6) {
1794 path_id = GET_BE_U_4(tptr);
1795 tptr += 4;
1796 }
1797 advance = decode_prefix6(ndo, tptr, len, buf, buflen);
1798 if (advance == -1)
1799 ND_PRINT("\n\t (illegal prefix length)");
1800 else if (advance == -2)
1801 break; /* bytes left, but not enough */
1802 else
1803 ND_PRINT("\n\t %s", buf);
1804 if (add_path6) {
1805 ND_PRINT(" Path Id: %u", path_id);
1806 advance += 4;
1807 }
1808 break;
1809 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
1810 advance = decode_labeled_prefix6(ndo, tptr, len, buf, buflen);
1811 if (advance == -1)
1812 ND_PRINT("\n\t (illegal prefix length)");
1813 else if (advance == -2)
1814 goto trunc;
1815 else if (advance == -3)
1816 break; /* bytes left, but not enough */
1817 else
1818 ND_PRINT("\n\t %s", buf);
1819 break;
1820 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
1821 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
1822 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
1823 advance = decode_labeled_vpn_prefix6(ndo, tptr, buf, buflen);
1824 if (advance == -1)
1825 ND_PRINT("\n\t (illegal prefix length)");
1826 else
1827 ND_PRINT("\n\t %s", buf);
1828 break;
1829 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
1830 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
1831 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
1832 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
1833 advance = decode_labeled_vpn_l2(ndo, tptr, buf, buflen);
1834 if (advance == -1)
1835 ND_PRINT("\n\t (illegal length)");
1836 else if (advance == -2)
1837 goto trunc;
1838 else
1839 ND_PRINT("\n\t %s", buf);
1840 break;
1841 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
1842 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
1843 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
1844 advance = decode_clnp_prefix(ndo, tptr, buf, buflen);
1845 if (advance == -1)
1846 ND_PRINT("\n\t (illegal prefix length)");
1847 else
1848 ND_PRINT("\n\t %s", buf);
1849 break;
1850 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
1851 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
1852 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
1853 advance = decode_labeled_vpn_clnp_prefix(ndo, tptr, buf, buflen);
1854 if (advance == -1)
1855 ND_PRINT("\n\t (illegal prefix length)");
1856 else
1857 ND_PRINT("\n\t %s", buf);
1858 break;
1859 default:
1860 /*
1861 * This should not happen, we should have been protected
1862 * by bgp_mp_af_print()'s return value.
1863 */
1864 ND_PRINT("\n\t ERROR: no AFI %u / SAFI %u decoder", af, safi);
1865 advance = -4;
1866 break;
1867 }
1868 return advance;
1869 trunc: /* we rely on the caller to recognize -2 return value */
1870 return -2;
1871 }
1872
1873 static int
bgp_attr_print(netdissect_options * ndo,uint8_t atype,const u_char * pptr,u_int len,const unsigned attr_set_level)1874 bgp_attr_print(netdissect_options *ndo,
1875 uint8_t atype, const u_char *pptr, u_int len,
1876 const unsigned attr_set_level)
1877 {
1878 /* allocate space for the largest possible string */
1879 char astostr[AS_STR_SIZE];
1880 u_int i;
1881 uint16_t af;
1882 uint8_t safi, snpa, nhlen;
1883 int advance;
1884 u_int tlen;
1885 const u_char *tptr;
1886 char buf[MAXHOSTNAMELEN + 100];
1887 u_int as_size;
1888 int add_path4, add_path6;
1889 int ret;
1890
1891 tptr = pptr;
1892 tlen = len;
1893
1894 switch (atype) {
1895 case BGPTYPE_ORIGIN:
1896 if (len != 1)
1897 ND_PRINT("invalid len");
1898 else {
1899 ND_PRINT("%s", tok2str(bgp_origin_values,
1900 "Unknown Origin Typecode",
1901 GET_U_1(tptr)));
1902 }
1903 break;
1904
1905 /*
1906 * Process AS4 byte path and AS2 byte path attributes here.
1907 */
1908 case BGPTYPE_AS4_PATH:
1909 case BGPTYPE_AS_PATH:
1910 if (len % 2) {
1911 ND_PRINT("invalid len");
1912 break;
1913 }
1914 if (!len) {
1915 ND_PRINT("empty");
1916 break;
1917 }
1918
1919 /*
1920 * BGP updates exchanged between New speakers that support 4
1921 * byte AS, ASs are always encoded in 4 bytes. There is no
1922 * definitive way to find this, just by the packet's
1923 * contents. So, check for packet's TLV's sanity assuming
1924 * 2 bytes first, and it does not pass, assume that ASs are
1925 * encoded in 4 bytes format and move on.
1926 */
1927 as_size = bgp_attr_get_as_size(ndo, atype, pptr, len);
1928
1929 while (tptr < pptr + len) {
1930 ND_PRINT("%s", tok2str(bgp_as_path_segment_open_values,
1931 "?", GET_U_1(tptr)));
1932 for (i = 0; i < GET_U_1(tptr + 1) * as_size; i += as_size) {
1933 ND_TCHECK_LEN(tptr + 2 + i, as_size);
1934 ND_PRINT("%s ",
1935 as_printf(ndo, astostr, sizeof(astostr),
1936 as_size == 2 ?
1937 GET_BE_U_2(tptr + i + 2) :
1938 GET_BE_U_4(tptr + i + 2)));
1939 }
1940 ND_PRINT("%s", tok2str(bgp_as_path_segment_close_values,
1941 "?", GET_U_1(tptr)));
1942 tptr += 2 + GET_U_1(tptr + 1) * as_size;
1943 }
1944 break;
1945 case BGPTYPE_NEXT_HOP:
1946 if (len != 4)
1947 ND_PRINT("invalid len");
1948 else {
1949 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
1950 }
1951 break;
1952 case BGPTYPE_MULTI_EXIT_DISC:
1953 case BGPTYPE_LOCAL_PREF:
1954 if (len != 4)
1955 ND_PRINT("invalid len");
1956 else {
1957 ND_PRINT("%u", GET_BE_U_4(tptr));
1958 }
1959 break;
1960 case BGPTYPE_ATOMIC_AGGREGATE:
1961 if (len != 0)
1962 ND_PRINT("invalid len");
1963 break;
1964 case BGPTYPE_AGGREGATOR:
1965
1966 /*
1967 * Depending on the AS encoded is of 2 bytes or of 4 bytes,
1968 * the length of this PA can be either 6 bytes or 8 bytes.
1969 */
1970 if (len != 6 && len != 8) {
1971 ND_PRINT("invalid len");
1972 break;
1973 }
1974 ND_TCHECK_LEN(tptr, len);
1975 if (len == 6) {
1976 ND_PRINT(" AS #%s, origin %s",
1977 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(tptr)),
1978 GET_IPADDR_STRING(tptr + 2));
1979 } else {
1980 ND_PRINT(" AS #%s, origin %s",
1981 as_printf(ndo, astostr, sizeof(astostr),
1982 GET_BE_U_4(tptr)), GET_IPADDR_STRING(tptr + 4));
1983 }
1984 break;
1985 case BGPTYPE_AGGREGATOR4:
1986 if (len != 8) {
1987 ND_PRINT("invalid len");
1988 break;
1989 }
1990 ND_PRINT(" AS #%s, origin %s",
1991 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)),
1992 GET_IPADDR_STRING(tptr + 4));
1993 break;
1994 case BGPTYPE_COMMUNITIES:
1995 if (len % 4) {
1996 ND_PRINT("invalid len");
1997 break;
1998 }
1999 while (tlen != 0) {
2000 uint32_t comm;
2001 ND_TCHECK_4(tptr);
2002 if (tlen < 4)
2003 goto trunc;
2004 comm = GET_BE_U_4(tptr);
2005 switch (comm) {
2006 case BGP_COMMUNITY_NO_EXPORT:
2007 ND_PRINT(" NO_EXPORT");
2008 break;
2009 case BGP_COMMUNITY_NO_ADVERT:
2010 ND_PRINT(" NO_ADVERTISE");
2011 break;
2012 case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
2013 ND_PRINT(" NO_EXPORT_SUBCONFED");
2014 break;
2015 default:
2016 ND_PRINT("%u:%u%s",
2017 (comm >> 16) & 0xffff,
2018 comm & 0xffff,
2019 (tlen>4) ? ", " : "");
2020 break;
2021 }
2022 tlen -=4;
2023 tptr +=4;
2024 }
2025 break;
2026 case BGPTYPE_ORIGINATOR_ID:
2027 if (len != 4) {
2028 ND_PRINT("invalid len");
2029 break;
2030 }
2031 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2032 break;
2033 case BGPTYPE_CLUSTER_LIST:
2034 if (len % 4) {
2035 ND_PRINT("invalid len");
2036 break;
2037 }
2038 while (tlen != 0) {
2039 if (tlen < 4)
2040 goto trunc;
2041 ND_PRINT("%s%s",
2042 GET_IPADDR_STRING(tptr),
2043 (tlen>4) ? ", " : "");
2044 tlen -=4;
2045 tptr +=4;
2046 }
2047 break;
2048 case BGPTYPE_MP_REACH_NLRI:
2049 ND_TCHECK_3(tptr);
2050 if (tlen < 3)
2051 goto trunc;
2052 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2053 if (ret == -2)
2054 goto trunc;
2055 if (ret < 0)
2056 break;
2057
2058 tptr += 3;
2059 tlen -= 3;
2060
2061 ND_TCHECK_1(tptr);
2062 if (tlen < 1)
2063 goto trunc;
2064 nhlen = GET_U_1(tptr);
2065 tptr++;
2066 tlen--;
2067
2068 if (nhlen) {
2069 u_int nnh = 0;
2070 uint8_t tnhlen = nhlen;
2071 if (tlen < tnhlen)
2072 goto trunc;
2073 ND_PRINT("\n\t nexthop: ");
2074 while (tnhlen != 0) {
2075 if (nnh++ > 0) {
2076 ND_PRINT(", " );
2077 }
2078 switch(af<<8 | safi) {
2079 case (AFNUM_INET<<8 | SAFNUM_UNICAST):
2080 case (AFNUM_INET<<8 | SAFNUM_MULTICAST):
2081 case (AFNUM_INET<<8 | SAFNUM_UNIMULTICAST):
2082 case (AFNUM_INET<<8 | SAFNUM_LABUNICAST):
2083 case (AFNUM_INET<<8 | SAFNUM_RT_ROUTING_INFO):
2084 case (AFNUM_INET<<8 | SAFNUM_MULTICAST_VPN):
2085 case (AFNUM_INET<<8 | SAFNUM_MDT):
2086 if (tnhlen < sizeof(nd_ipv4)) {
2087 ND_PRINT("invalid len");
2088 tptr += tnhlen;
2089 tlen -= tnhlen;
2090 tnhlen = 0;
2091 } else {
2092 ND_PRINT("%s",GET_IPADDR_STRING(tptr));
2093 tptr += sizeof(nd_ipv4);
2094 tnhlen -= sizeof(nd_ipv4);
2095 tlen -= sizeof(nd_ipv4);
2096 }
2097 break;
2098 case (AFNUM_INET<<8 | SAFNUM_VPNUNICAST):
2099 case (AFNUM_INET<<8 | SAFNUM_VPNMULTICAST):
2100 case (AFNUM_INET<<8 | SAFNUM_VPNUNIMULTICAST):
2101 if (tnhlen < sizeof(nd_ipv4)+BGP_VPN_RD_LEN) {
2102 ND_PRINT("invalid len");
2103 tptr += tnhlen;
2104 tlen -= tnhlen;
2105 tnhlen = 0;
2106 } else {
2107 ND_PRINT("RD: %s, %s",
2108 bgp_vpn_rd_print(ndo, tptr),
2109 GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN));
2110 tptr += (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2111 tlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2112 tnhlen -= (sizeof(nd_ipv4)+BGP_VPN_RD_LEN);
2113 }
2114 break;
2115 case (AFNUM_INET6<<8 | SAFNUM_UNICAST):
2116 case (AFNUM_INET6<<8 | SAFNUM_MULTICAST):
2117 case (AFNUM_INET6<<8 | SAFNUM_UNIMULTICAST):
2118 case (AFNUM_INET6<<8 | SAFNUM_LABUNICAST):
2119 if (tnhlen < sizeof(nd_ipv6)) {
2120 ND_PRINT("invalid len");
2121 tptr += tnhlen;
2122 tlen -= tnhlen;
2123 tnhlen = 0;
2124 } else {
2125 ND_PRINT("%s", GET_IP6ADDR_STRING(tptr));
2126 tptr += sizeof(nd_ipv6);
2127 tlen -= sizeof(nd_ipv6);
2128 tnhlen -= sizeof(nd_ipv6);
2129 }
2130 break;
2131 case (AFNUM_INET6<<8 | SAFNUM_VPNUNICAST):
2132 case (AFNUM_INET6<<8 | SAFNUM_VPNMULTICAST):
2133 case (AFNUM_INET6<<8 | SAFNUM_VPNUNIMULTICAST):
2134 if (tnhlen < sizeof(nd_ipv6)+BGP_VPN_RD_LEN) {
2135 ND_PRINT("invalid len");
2136 tptr += tnhlen;
2137 tlen -= tnhlen;
2138 tnhlen = 0;
2139 } else {
2140 ND_PRINT("RD: %s, %s",
2141 bgp_vpn_rd_print(ndo, tptr),
2142 GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN));
2143 tptr += (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2144 tlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2145 tnhlen -= (sizeof(nd_ipv6)+BGP_VPN_RD_LEN);
2146 }
2147 break;
2148 case (AFNUM_VPLS<<8 | SAFNUM_VPLS):
2149 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNICAST):
2150 case (AFNUM_L2VPN<<8 | SAFNUM_VPNMULTICAST):
2151 case (AFNUM_L2VPN<<8 | SAFNUM_VPNUNIMULTICAST):
2152 if (tnhlen < sizeof(nd_ipv4)) {
2153 ND_PRINT("invalid len");
2154 tptr += tnhlen;
2155 tlen -= tnhlen;
2156 tnhlen = 0;
2157 } else {
2158 ND_PRINT("%s", GET_IPADDR_STRING(tptr));
2159 tptr += (sizeof(nd_ipv4));
2160 tlen -= (sizeof(nd_ipv4));
2161 tnhlen -= (sizeof(nd_ipv4));
2162 }
2163 break;
2164 case (AFNUM_NSAP<<8 | SAFNUM_UNICAST):
2165 case (AFNUM_NSAP<<8 | SAFNUM_MULTICAST):
2166 case (AFNUM_NSAP<<8 | SAFNUM_UNIMULTICAST):
2167 ND_PRINT("%s", GET_ISONSAP_STRING(tptr, tnhlen));
2168 tptr += tnhlen;
2169 tlen -= tnhlen;
2170 tnhlen = 0;
2171 break;
2172
2173 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNICAST):
2174 case (AFNUM_NSAP<<8 | SAFNUM_VPNMULTICAST):
2175 case (AFNUM_NSAP<<8 | SAFNUM_VPNUNIMULTICAST):
2176 if (tnhlen < BGP_VPN_RD_LEN+1) {
2177 ND_PRINT("invalid len");
2178 tptr += tnhlen;
2179 tlen -= tnhlen;
2180 tnhlen = 0;
2181 } else {
2182 ND_TCHECK_LEN(tptr, tnhlen);
2183 ND_PRINT("RD: %s, %s",
2184 bgp_vpn_rd_print(ndo, tptr),
2185 GET_ISONSAP_STRING(tptr+BGP_VPN_RD_LEN,tnhlen-BGP_VPN_RD_LEN));
2186 /* rfc986 mapped IPv4 address ? */
2187 if (GET_BE_U_4(tptr + BGP_VPN_RD_LEN) == 0x47000601)
2188 ND_PRINT(" = %s", GET_IPADDR_STRING(tptr+BGP_VPN_RD_LEN+4));
2189 /* rfc1888 mapped IPv6 address ? */
2190 else if (GET_BE_U_3(tptr + BGP_VPN_RD_LEN) == 0x350000)
2191 ND_PRINT(" = %s", GET_IP6ADDR_STRING(tptr+BGP_VPN_RD_LEN+3));
2192 tptr += tnhlen;
2193 tlen -= tnhlen;
2194 tnhlen = 0;
2195 }
2196 break;
2197 default:
2198 /*
2199 * bgp_mp_af_print() should have saved us from
2200 * an unsupported AFI/SAFI.
2201 */
2202 ND_PRINT("ERROR: no AFI %u/SAFI %u nexthop decoder", af, safi);
2203 tptr += tnhlen;
2204 tlen -= tnhlen;
2205 tnhlen = 0;
2206 goto done;
2207 break;
2208 }
2209 }
2210 }
2211 ND_PRINT(", nh-length: %u", nhlen);
2212
2213 /* As per RFC 2858; this is reserved in RFC 4760 */
2214 if (tlen < 1)
2215 goto trunc;
2216 snpa = GET_U_1(tptr);
2217 tptr++;
2218 tlen--;
2219
2220 if (snpa) {
2221 ND_PRINT("\n\t %u SNPA", snpa);
2222 for (/*nothing*/; snpa != 0; snpa--) {
2223 uint8_t snpalen;
2224 if (tlen < 1)
2225 goto trunc;
2226 snpalen = GET_U_1(tptr);
2227 ND_PRINT("\n\t %u bytes", snpalen);
2228 tptr++;
2229 tlen--;
2230 if (tlen < snpalen)
2231 goto trunc;
2232 ND_TCHECK_LEN(tptr, snpalen);
2233 tptr += snpalen;
2234 tlen -= snpalen;
2235 }
2236 } else {
2237 ND_PRINT(", no SNPA");
2238 }
2239
2240 add_path4 = check_add_path(ndo, tptr,
2241 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2242 add_path6 = check_add_path(ndo, tptr,
2243 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2244
2245 while (tptr < pptr + len) {
2246 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2247 add_path4, add_path6);
2248 if (advance == -2)
2249 goto trunc;
2250 if (advance < 0)
2251 break;
2252 tptr += advance;
2253 }
2254 break;
2255
2256 case BGPTYPE_MP_UNREACH_NLRI:
2257 ND_TCHECK_LEN(tptr, BGP_MP_NLRI_MINSIZE);
2258 ret = bgp_mp_af_print(ndo, tptr, tlen, &af, &safi);
2259 if (ret == -2)
2260 goto trunc;
2261 if (ret < 0)
2262 break;
2263
2264 if (len == BGP_MP_NLRI_MINSIZE)
2265 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2266
2267 tptr += 3;
2268
2269 add_path4 = check_add_path(ndo, tptr,
2270 (len-ND_BYTES_BETWEEN(pptr, tptr)), 32);
2271 add_path6 = check_add_path(ndo, tptr,
2272 (len-ND_BYTES_BETWEEN(pptr, tptr)), 128);
2273
2274 while (tptr < pptr + len) {
2275 advance = bgp_nlri_print(ndo, af, safi, tptr, len, buf, sizeof(buf),
2276 add_path4, add_path6);
2277 if (advance == -2)
2278 goto trunc;
2279 if (advance < 0)
2280 break;
2281 tptr += advance;
2282 }
2283 break;
2284 case BGPTYPE_EXTD_COMMUNITIES:
2285 if (len % 8) {
2286 ND_PRINT("invalid len");
2287 break;
2288 }
2289 while (tlen != 0) {
2290 uint16_t extd_comm;
2291
2292 ND_TCHECK_2(tptr);
2293 if (tlen < 2)
2294 goto trunc;
2295 extd_comm=GET_BE_U_2(tptr);
2296
2297 ND_PRINT("\n\t %s (0x%04x), Flags [%s]",
2298 tok2str(bgp_extd_comm_subtype_values,
2299 "unknown extd community typecode",
2300 extd_comm),
2301 extd_comm,
2302 bittok2str(bgp_extd_comm_flag_values, "none", extd_comm));
2303
2304 ND_TCHECK_8(tptr);
2305 if (tlen < 8)
2306 goto trunc;
2307 ND_PRINT(": ");
2308 bgp_extended_community_print(ndo, tptr);
2309 tlen -= 8;
2310 tptr += 8;
2311 }
2312 break;
2313
2314 case BGPTYPE_PMSI_TUNNEL:
2315 {
2316 uint8_t tunnel_type, flags;
2317
2318 ND_TCHECK_5(tptr);
2319 if (tlen < 5)
2320 goto trunc;
2321 flags = GET_U_1(tptr);
2322 tunnel_type = GET_U_1(tptr + 1);
2323
2324 ND_PRINT("\n\t Tunnel-type %s (%u), Flags [%s], MPLS Label %u",
2325 tok2str(bgp_pmsi_tunnel_values, "Unknown", tunnel_type),
2326 tunnel_type,
2327 bittok2str(bgp_pmsi_flag_values, "none", flags),
2328 GET_BE_U_3(tptr + 2)>>4);
2329
2330 tptr +=5;
2331 tlen -= 5;
2332
2333 switch (tunnel_type) {
2334 case BGP_PMSI_TUNNEL_PIM_SM: /* fall through */
2335 case BGP_PMSI_TUNNEL_PIM_BIDIR:
2336 ND_PRINT("\n\t Sender %s, P-Group %s",
2337 GET_IPADDR_STRING(tptr),
2338 GET_IPADDR_STRING(tptr+4));
2339 break;
2340
2341 case BGP_PMSI_TUNNEL_PIM_SSM:
2342 ND_PRINT("\n\t Root-Node %s, P-Group %s",
2343 GET_IPADDR_STRING(tptr),
2344 GET_IPADDR_STRING(tptr+4));
2345 break;
2346 case BGP_PMSI_TUNNEL_INGRESS:
2347 ND_PRINT("\n\t Tunnel-Endpoint %s",
2348 GET_IPADDR_STRING(tptr));
2349 break;
2350 case BGP_PMSI_TUNNEL_LDP_P2MP: /* fall through */
2351 case BGP_PMSI_TUNNEL_LDP_MP2MP:
2352 ND_PRINT("\n\t Root-Node %s, LSP-ID 0x%08x",
2353 GET_IPADDR_STRING(tptr),
2354 GET_BE_U_4(tptr + 4));
2355 break;
2356 case BGP_PMSI_TUNNEL_RSVP_P2MP:
2357 ND_PRINT("\n\t Extended-Tunnel-ID %s, P2MP-ID 0x%08x",
2358 GET_IPADDR_STRING(tptr),
2359 GET_BE_U_4(tptr + 4));
2360 break;
2361 default:
2362 if (ndo->ndo_vflag <= 1) {
2363 print_unknown_data(ndo, tptr, "\n\t ", tlen);
2364 }
2365 }
2366 break;
2367 }
2368 case BGPTYPE_AIGP:
2369 {
2370 uint8_t type;
2371 uint16_t length;
2372
2373 while (tlen >= 3) {
2374 type = GET_U_1(tptr);
2375 length = GET_BE_U_2(tptr + 1);
2376 tptr += 3;
2377 tlen -= 3;
2378
2379 ND_PRINT("\n\t %s TLV (%u), length %u",
2380 tok2str(bgp_aigp_values, "Unknown", type),
2381 type, length);
2382
2383 if (length < 3)
2384 goto trunc;
2385 length -= 3;
2386
2387 /*
2388 * Check if we can read the TLV data.
2389 */
2390 if (tlen < length)
2391 goto trunc;
2392
2393 switch (type) {
2394
2395 case BGP_AIGP_TLV:
2396 if (length < 8)
2397 goto trunc;
2398 ND_PRINT(", metric %" PRIu64,
2399 GET_BE_U_8(tptr));
2400 break;
2401
2402 default:
2403 if (ndo->ndo_vflag <= 1) {
2404 print_unknown_data(ndo, tptr,"\n\t ", length);
2405 }
2406 }
2407
2408 tptr += length;
2409 tlen -= length;
2410 }
2411 break;
2412 }
2413 case BGPTYPE_ATTR_SET:
2414 ND_TCHECK_4(tptr);
2415 if (len < 4)
2416 goto trunc;
2417 ND_PRINT("\n\t Origin AS: %s",
2418 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_4(tptr)));
2419 tptr += 4;
2420 len -= 4;
2421
2422 while (len) {
2423 u_int aflags, alenlen, alen;
2424
2425 ND_TCHECK_2(tptr);
2426 if (len < 2) {
2427 ND_PRINT(" [path attr too short]");
2428 tptr += len;
2429 break;
2430 }
2431 aflags = GET_U_1(tptr);
2432 atype = GET_U_1(tptr + 1);
2433 tptr += 2;
2434 len -= 2;
2435 alenlen = bgp_attr_lenlen(aflags, tptr);
2436 ND_TCHECK_LEN(tptr, alenlen);
2437 if (len < alenlen) {
2438 ND_PRINT(" [path attr too short]");
2439 tptr += len;
2440 break;
2441 }
2442 alen = bgp_attr_len(aflags, tptr);
2443 tptr += alenlen;
2444 len -= alenlen;
2445
2446 ND_PRINT("\n\t %s (%u), length: %u",
2447 tok2str(bgp_attr_values,
2448 "Unknown Attribute", atype),
2449 atype,
2450 alen);
2451
2452 if (aflags) {
2453 ND_PRINT(", Flags [%s%s%s%s",
2454 aflags & 0x80 ? "O" : "",
2455 aflags & 0x40 ? "T" : "",
2456 aflags & 0x20 ? "P" : "",
2457 aflags & 0x10 ? "E" : "");
2458 if (aflags & 0xf)
2459 ND_PRINT("+%x", aflags & 0xf);
2460 ND_PRINT("]");
2461 }
2462 ND_PRINT(": ");
2463 if (len < alen) {
2464 ND_PRINT(" [path attr too short]");
2465 tptr += len;
2466 break;
2467 }
2468 /*
2469 * The protocol encoding per se allows ATTR_SET to be nested
2470 * as many times as the message can accommodate. This printer
2471 * used to be able to recurse into ATTR_SET contents until the
2472 * stack exhaustion, but now there is a limit on that (if live
2473 * protocol exchange goes that many levels deep, something is
2474 * probably wrong anyway). Feel free to refine this value if
2475 * you can find the spec with respective normative text.
2476 */
2477 if (attr_set_level == 10)
2478 ND_PRINT("(too many nested levels, not recursing)");
2479 else if (!bgp_attr_print(ndo, atype, tptr, alen, attr_set_level + 1))
2480 return 0;
2481 tptr += alen;
2482 len -= alen;
2483 }
2484 break;
2485
2486 case BGPTYPE_LARGE_COMMUNITY:
2487 if (len == 0 || len % 12) {
2488 ND_PRINT("invalid len");
2489 break;
2490 }
2491 ND_PRINT("\n\t ");
2492 while (len != 0) {
2493 ND_PRINT("%u:%u:%u%s",
2494 GET_BE_U_4(tptr),
2495 GET_BE_U_4(tptr + 4),
2496 GET_BE_U_4(tptr + 8),
2497 (len > 12) ? ", " : "");
2498 tptr += 12;
2499 /*
2500 * len will always be a multiple of 12, as per the above,
2501 * so this will never underflow.
2502 */
2503 len -= 12;
2504 }
2505 break;
2506 default:
2507 ND_TCHECK_LEN(pptr, len);
2508 ND_PRINT("\n\t no Attribute %u decoder", atype); /* we have no decoder for the attribute */
2509 if (ndo->ndo_vflag <= 1)
2510 print_unknown_data(ndo, pptr, "\n\t ", len);
2511 break;
2512 }
2513 done:
2514 if (ndo->ndo_vflag > 1 && len) { /* omit zero length attributes*/
2515 ND_TCHECK_LEN(pptr, len);
2516 print_unknown_data(ndo, pptr, "\n\t ", len);
2517 }
2518 return 1;
2519
2520 trunc:
2521 return 0;
2522 }
2523
2524 static void
bgp_capabilities_print(netdissect_options * ndo,const u_char * opt,u_int caps_len)2525 bgp_capabilities_print(netdissect_options *ndo,
2526 const u_char *opt, u_int caps_len)
2527 {
2528 /* allocate space for the largest possible string */
2529 char astostr[AS_STR_SIZE];
2530 u_int cap_type, cap_len, tcap_len, cap_offset;
2531 u_int i = 0;
2532
2533 while (i < caps_len) {
2534 ND_TCHECK_LEN(opt + i, BGP_CAP_HEADER_SIZE);
2535 cap_type=GET_U_1(opt + i);
2536 cap_len=GET_U_1(opt + i + 1);
2537 ND_PRINT("\n\t %s (%u), length: %u",
2538 tok2str(bgp_capcode_values, "Unknown", cap_type),
2539 cap_type,
2540 cap_len);
2541 ND_TCHECK_LEN(opt + 2 + i, cap_len);
2542 switch (cap_type) {
2543 case BGP_CAPCODE_MP:
2544 /* AFI (16 bits), Reserved (8 bits), SAFI (8 bits) */
2545 if (cap_len < 4) {
2546 ND_PRINT(" (too short, < 4)");
2547 return;
2548 }
2549 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u)",
2550 tok2str(af_values, "Unknown", GET_BE_U_2(opt + i + 2)),
2551 GET_BE_U_2(opt + i + 2),
2552 tok2str(bgp_safi_values, "Unknown", GET_U_1(opt + i + 5)),
2553 GET_U_1(opt + i + 5));
2554 break;
2555 case BGP_CAPCODE_ML:
2556 cap_offset = 2;
2557 tcap_len = cap_len;
2558 while (tcap_len >= 4) {
2559 ND_PRINT( "\n\t\tAFI %s (%u), SAFI %s (%u), Count: %u",
2560 tok2str(af_values, "Unknown",
2561 GET_BE_U_2(opt + i + cap_offset)),
2562 GET_BE_U_2(opt + i + cap_offset),
2563 tok2str(bgp_safi_values, "Unknown",
2564 GET_U_1(opt + i + cap_offset + 2)),
2565 GET_U_1(opt + i + cap_offset + 2),
2566 GET_U_1(opt + i + cap_offset + 3));
2567 tcap_len -= 4;
2568 cap_offset += 4;
2569 }
2570 break;
2571 case BGP_CAPCODE_RESTART:
2572 /* Restart Flags (4 bits), Restart Time in seconds (12 bits) */
2573 if (cap_len < 2) {
2574 ND_PRINT(" (too short, < 2)");
2575 return;
2576 }
2577 tcap_len=cap_len;
2578 ND_PRINT("\n\t\tRestart Flags: [%s], Restart Time %us",
2579 ((GET_U_1(opt + i + 2))&0x80) ? "R" : "none",
2580 GET_BE_U_2(opt + i + 2)&0xfff);
2581 tcap_len-=2;
2582 cap_offset=4;
2583 while(tcap_len>=4) {
2584 ND_PRINT("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s",
2585 tok2str(af_values,"Unknown",
2586 GET_BE_U_2(opt + i + cap_offset)),
2587 GET_BE_U_2(opt + i + cap_offset),
2588 tok2str(bgp_safi_values,"Unknown",
2589 GET_U_1(opt + i + cap_offset + 2)),
2590 GET_U_1(opt + (i + cap_offset + 2)),
2591 ((GET_U_1(opt + (i + cap_offset + 3)))&0x80) ? "yes" : "no" );
2592 tcap_len -= 4;
2593 cap_offset += 4;
2594 }
2595 break;
2596 case BGP_CAPCODE_RR:
2597 case BGP_CAPCODE_LLGR:
2598 case BGP_CAPCODE_RR_CISCO:
2599 break;
2600 case BGP_CAPCODE_AS_NEW:
2601 /*
2602 * Extract the 4 byte AS number encoded.
2603 */
2604 if (cap_len < 4) {
2605 ND_PRINT(" (too short, < 4)");
2606 return;
2607 }
2608 ND_PRINT("\n\t\t 4 Byte AS %s",
2609 as_printf(ndo, astostr, sizeof(astostr),
2610 GET_BE_U_4(opt + i + 2)));
2611 break;
2612 case BGP_CAPCODE_ADD_PATH:
2613 if (cap_len == 0) {
2614 ND_PRINT(" (bogus)"); /* length */
2615 break;
2616 }
2617 tcap_len=cap_len;
2618 cap_offset=2;
2619 while (tcap_len != 0) {
2620 if (tcap_len < 4) {
2621 nd_print_invalid(ndo);
2622 break;
2623 }
2624 ND_PRINT("\n\t\tAFI %s (%u), SAFI %s (%u), Send/Receive: %s",
2625 tok2str(af_values,"Unknown",GET_BE_U_2(opt + i + cap_offset)),
2626 GET_BE_U_2(opt + i + cap_offset),
2627 tok2str(bgp_safi_values,"Unknown",GET_U_1(opt + i + cap_offset + 2)),
2628 GET_U_1(opt + (i + cap_offset + 2)),
2629 tok2str(bgp_add_path_recvsend,"Bogus (0x%02x)",GET_U_1(opt + i + cap_offset + 3))
2630 );
2631 tcap_len -= 4;
2632 cap_offset += 4;
2633 }
2634 break;
2635 default:
2636 ND_PRINT("\n\t\tno decoder for Capability %u",
2637 cap_type);
2638 if (ndo->ndo_vflag <= 1)
2639 print_unknown_data(ndo, opt + i + 2, "\n\t\t",
2640 cap_len);
2641 break;
2642 }
2643 if (ndo->ndo_vflag > 1 && cap_len != 0) {
2644 print_unknown_data(ndo, opt + i + 2, "\n\t\t", cap_len);
2645 }
2646 i += BGP_CAP_HEADER_SIZE + cap_len;
2647 }
2648 return;
2649
2650 trunc:
2651 nd_print_trunc(ndo);
2652 }
2653
2654 static void
bgp_open_print(netdissect_options * ndo,const u_char * dat,u_int length)2655 bgp_open_print(netdissect_options *ndo,
2656 const u_char *dat, u_int length)
2657 {
2658 /* allocate space for the largest possible string */
2659 char astostr[AS_STR_SIZE];
2660 const struct bgp_open *bgp_open_header;
2661 u_int optslen;
2662 const struct bgp_opt *bgpopt;
2663 const u_char *opt;
2664 u_int i;
2665
2666 ND_TCHECK_LEN(dat, BGP_OPEN_SIZE);
2667 if (length < BGP_OPEN_SIZE)
2668 goto trunc;
2669
2670 bgp_open_header = (const struct bgp_open *)dat;
2671
2672 ND_PRINT("\n\t Version %u, ",
2673 GET_U_1(bgp_open_header->bgpo_version));
2674 ND_PRINT("my AS %s, ",
2675 as_printf(ndo, astostr, sizeof(astostr), GET_BE_U_2(bgp_open_header->bgpo_myas)));
2676 ND_PRINT("Holdtime %us, ",
2677 GET_BE_U_2(bgp_open_header->bgpo_holdtime));
2678 ND_PRINT("ID %s", GET_IPADDR_STRING(bgp_open_header->bgpo_id));
2679 optslen = GET_U_1(bgp_open_header->bgpo_optlen);
2680 ND_PRINT("\n\t Optional parameters, length: %u", optslen);
2681
2682 opt = dat + BGP_OPEN_SIZE;
2683 length -= BGP_OPEN_SIZE;
2684
2685 i = 0;
2686 while (i < optslen) {
2687 uint8_t opt_type, opt_len;
2688
2689 ND_TCHECK_LEN(opt + i, BGP_OPT_SIZE);
2690 if (length < BGP_OPT_SIZE + i)
2691 goto trunc;
2692 bgpopt = (const struct bgp_opt *)(opt + i);
2693 opt_type = GET_U_1(bgpopt->bgpopt_type);
2694 opt_len = GET_U_1(bgpopt->bgpopt_len);
2695 if (BGP_OPT_SIZE + i + opt_len > optslen) {
2696 ND_PRINT("\n\t Option %u, length: %u, goes past the end of the options",
2697 opt_type, opt_len);
2698 break;
2699 }
2700
2701 ND_PRINT("\n\t Option %s (%u), length: %u",
2702 tok2str(bgp_opt_values,"Unknown",opt_type),
2703 opt_type,
2704 opt_len);
2705
2706 /* now let's decode the options we know*/
2707 switch(opt_type) {
2708
2709 case BGP_OPT_CAP:
2710 bgp_capabilities_print(ndo, opt + BGP_OPT_SIZE + i,
2711 opt_len);
2712 break;
2713
2714 case BGP_OPT_AUTH:
2715 default:
2716 ND_PRINT("\n\t no decoder for option %u",
2717 opt_type);
2718 break;
2719 }
2720 i += BGP_OPT_SIZE + opt_len;
2721 }
2722 return;
2723 trunc:
2724 nd_print_trunc(ndo);
2725 }
2726
2727 static void
bgp_update_print(netdissect_options * ndo,const u_char * dat,u_int length)2728 bgp_update_print(netdissect_options *ndo,
2729 const u_char *dat, u_int length)
2730 {
2731 const u_char *p;
2732 u_int withdrawn_routes_len;
2733 char buf[MAXHOSTNAMELEN + 100];
2734 int wpfx;
2735 u_int len;
2736 int i;
2737 int add_path;
2738 u_int path_id = 0;
2739
2740 ND_TCHECK_LEN(dat, BGP_SIZE);
2741 if (length < BGP_SIZE)
2742 goto trunc;
2743 p = dat + BGP_SIZE;
2744 length -= BGP_SIZE;
2745
2746 /* Unfeasible routes */
2747 ND_TCHECK_2(p);
2748 if (length < 2)
2749 goto trunc;
2750 withdrawn_routes_len = GET_BE_U_2(p);
2751 p += 2;
2752 length -= 2;
2753 if (withdrawn_routes_len > 1) {
2754 /*
2755 * Without keeping state from the original NLRI message,
2756 * it's not possible to tell if this a v4 or v6 route,
2757 * so only try to decode it if we're not v6 enabled.
2758 */
2759 ND_TCHECK_LEN(p, withdrawn_routes_len);
2760 if (length < withdrawn_routes_len)
2761 goto trunc;
2762 ND_PRINT("\n\t Withdrawn routes:");
2763 add_path = check_add_path(ndo, p, withdrawn_routes_len, 32);
2764 while (withdrawn_routes_len != 0) {
2765 if (add_path) {
2766 if (withdrawn_routes_len < 4) {
2767 p += withdrawn_routes_len;
2768 length -= withdrawn_routes_len;
2769 break;
2770 }
2771 path_id = GET_BE_U_4(p);
2772 p += 4;
2773 length -= 4;
2774 withdrawn_routes_len -= 4;
2775 }
2776 wpfx = decode_prefix4(ndo, p, withdrawn_routes_len, buf, sizeof(buf));
2777 if (wpfx == -1) {
2778 ND_PRINT("\n\t (illegal prefix length)");
2779 break;
2780 } else if (wpfx == -2)
2781 goto trunc; /* bytes left, but not enough */
2782 else {
2783 ND_PRINT("\n\t %s", buf);
2784 if (add_path) {
2785 ND_PRINT(" Path Id: %u", path_id);
2786 }
2787 p += wpfx;
2788 length -= wpfx;
2789 withdrawn_routes_len -= wpfx;
2790 }
2791 }
2792 } else {
2793 ND_TCHECK_LEN(p, withdrawn_routes_len);
2794 if (length < withdrawn_routes_len)
2795 goto trunc;
2796 p += withdrawn_routes_len;
2797 length -= withdrawn_routes_len;
2798 }
2799
2800 ND_TCHECK_2(p);
2801 if (length < 2)
2802 goto trunc;
2803 len = GET_BE_U_2(p);
2804 p += 2;
2805 length -= 2;
2806
2807 if (withdrawn_routes_len == 0 && len == 0 && length == 0) {
2808 /* No withdrawn routes, no path attributes, no NLRI */
2809 ND_PRINT("\n\t End-of-Rib Marker (empty NLRI)");
2810 return;
2811 }
2812
2813 if (len) {
2814 /* Make sure the path attributes don't go past the end of the packet */
2815 if (length < len)
2816 goto trunc;
2817 /* do something more useful!*/
2818 while (len) {
2819 uint8_t aflags, atype, alenlen;
2820 uint16_t alen;
2821
2822 ND_TCHECK_2(p);
2823 if (length < 2)
2824 goto trunc;
2825 if (len < 2) {
2826 ND_PRINT("\n\t [path attrs too short]");
2827 p += len;
2828 length -= len;
2829 break;
2830 }
2831 aflags = GET_U_1(p);
2832 atype = GET_U_1(p + 1);
2833 p += 2;
2834 len -= 2;
2835 length -= 2;
2836 alenlen = bgp_attr_lenlen(aflags, p);
2837 ND_TCHECK_LEN(p, alenlen);
2838 if (length < alenlen)
2839 goto trunc;
2840 if (len < alenlen) {
2841 ND_PRINT("\n\t [path attrs too short]");
2842 p += len;
2843 length -= len;
2844 break;
2845 }
2846 alen = bgp_attr_len(aflags, p);
2847 p += alenlen;
2848 len -= alenlen;
2849 length -= alenlen;
2850
2851 ND_PRINT("\n\t %s (%u), length: %u",
2852 tok2str(bgp_attr_values, "Unknown Attribute", atype),
2853 atype,
2854 alen);
2855
2856 if (aflags) {
2857 ND_PRINT(", Flags [%s%s%s%s",
2858 aflags & 0x80 ? "O" : "",
2859 aflags & 0x40 ? "T" : "",
2860 aflags & 0x20 ? "P" : "",
2861 aflags & 0x10 ? "E" : "");
2862 if (aflags & 0xf)
2863 ND_PRINT("+%x", aflags & 0xf);
2864 ND_PRINT("]: ");
2865 }
2866 if (len < alen) {
2867 ND_PRINT(" [path attrs too short]");
2868 p += len;
2869 length -= len;
2870 break;
2871 }
2872 if (length < alen)
2873 goto trunc;
2874 if (!bgp_attr_print(ndo, atype, p, alen, 0))
2875 goto trunc;
2876 p += alen;
2877 len -= alen;
2878 length -= alen;
2879 }
2880 }
2881
2882 if (length) {
2883 add_path = check_add_path(ndo, p, length, 32);
2884 ND_PRINT("\n\t Updated routes:");
2885 while (length != 0) {
2886 if (add_path) {
2887 ND_TCHECK_4(p);
2888 if (length < 4)
2889 goto trunc;
2890 path_id = GET_BE_U_4(p);
2891 p += 4;
2892 length -= 4;
2893 }
2894 i = decode_prefix4(ndo, p, length, buf, sizeof(buf));
2895 if (i == -1) {
2896 ND_PRINT("\n\t (illegal prefix length)");
2897 break;
2898 } else if (i == -2)
2899 goto trunc; /* bytes left, but not enough */
2900 else {
2901 ND_PRINT("\n\t %s", buf);
2902 if (add_path) {
2903 ND_PRINT(" Path Id: %u", path_id);
2904 }
2905 p += i;
2906 length -= i;
2907 }
2908 }
2909 }
2910 return;
2911 trunc:
2912 nd_print_trunc(ndo);
2913 }
2914
2915 static void
bgp_notification_print(netdissect_options * ndo,const u_char * dat,u_int length)2916 bgp_notification_print(netdissect_options *ndo,
2917 const u_char *dat, u_int length)
2918 {
2919 const struct bgp_notification *bgp_notification_header;
2920 const u_char *tptr;
2921 uint8_t bgpn_major, bgpn_minor;
2922
2923 ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
2924 if (length<BGP_NOTIFICATION_SIZE)
2925 return;
2926
2927 bgp_notification_header = (const struct bgp_notification *)dat;
2928 bgpn_major = GET_U_1(bgp_notification_header->bgpn_major);
2929 bgpn_minor = GET_U_1(bgp_notification_header->bgpn_minor);
2930
2931 ND_PRINT(", %s (%u)",
2932 tok2str(bgp_notify_major_values, "Unknown Error",
2933 bgpn_major),
2934 bgpn_major);
2935
2936 switch (bgpn_major) {
2937
2938 case BGP_NOTIFY_MAJOR_MSG:
2939 ND_PRINT(", subcode %s (%u)",
2940 tok2str(bgp_notify_minor_msg_values, "Unknown",
2941 bgpn_minor),
2942 bgpn_minor);
2943 break;
2944 case BGP_NOTIFY_MAJOR_OPEN:
2945 ND_PRINT(", subcode %s (%u)",
2946 tok2str(bgp_notify_minor_open_values, "Unknown",
2947 bgpn_minor),
2948 bgpn_minor);
2949 break;
2950 case BGP_NOTIFY_MAJOR_UPDATE:
2951 ND_PRINT(", subcode %s (%u)",
2952 tok2str(bgp_notify_minor_update_values, "Unknown",
2953 bgpn_minor),
2954 bgpn_minor);
2955 break;
2956 case BGP_NOTIFY_MAJOR_FSM:
2957 ND_PRINT(" subcode %s (%u)",
2958 tok2str(bgp_notify_minor_fsm_values, "Unknown",
2959 bgpn_minor),
2960 bgpn_minor);
2961 break;
2962 case BGP_NOTIFY_MAJOR_CAP:
2963 ND_PRINT(" subcode %s (%u)",
2964 tok2str(bgp_notify_minor_cap_values, "Unknown",
2965 bgpn_minor),
2966 bgpn_minor);
2967 break;
2968 case BGP_NOTIFY_MAJOR_CEASE:
2969 ND_PRINT(", subcode %s (%u)",
2970 tok2str(bgp_notify_minor_cease_values, "Unknown",
2971 bgpn_minor),
2972 bgpn_minor);
2973
2974 /* RFC 4486 mentions optionally 7 bytes
2975 * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
2976 */
2977 if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
2978 tptr = dat + BGP_NOTIFICATION_SIZE;
2979 ND_PRINT(", AFI %s (%u), SAFI %s (%u), Max Prefixes: %u",
2980 tok2str(af_values, "Unknown", GET_BE_U_2(tptr)),
2981 GET_BE_U_2(tptr),
2982 tok2str(bgp_safi_values, "Unknown", GET_U_1((tptr + 2))),
2983 GET_U_1((tptr + 2)),
2984 GET_BE_U_4(tptr + 3));
2985 }
2986 /*
2987 * RFC 9003 describes a method to send a communication
2988 * intended for human consumption regarding the Administrative Shutdown
2989 */
2990 if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
2991 bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
2992 length >= BGP_NOTIFICATION_SIZE + 1) {
2993 tptr = dat + BGP_NOTIFICATION_SIZE;
2994 uint8_t shutdown_comm_length = GET_U_1(tptr);
2995 uint8_t remainder_offset = 0;
2996 /* garbage, hexdump it all */
2997 if (shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
2998 ND_PRINT(", invalid Shutdown Communication length");
2999 } else if (shutdown_comm_length == 0) {
3000 ND_PRINT(", empty Shutdown Communication");
3001 remainder_offset += 1;
3002 }
3003 /* a proper shutdown communication */
3004 else {
3005 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
3006 (void)nd_printn(ndo, tptr+1, shutdown_comm_length, NULL);
3007 ND_PRINT("\"");
3008 remainder_offset += shutdown_comm_length + 1;
3009 }
3010 /* if there is trailing data, hexdump it */
3011 if(length - (remainder_offset + BGP_NOTIFICATION_SIZE) > 0) {
3012 ND_PRINT(", Data: (length: %u)", length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3013 hex_print(ndo, "\n\t\t", tptr + remainder_offset, length - (remainder_offset + BGP_NOTIFICATION_SIZE));
3014 }
3015 }
3016 break;
3017 default:
3018 break;
3019 }
3020
3021 return;
3022 trunc:
3023 nd_print_trunc(ndo);
3024 }
3025
3026 static void
bgp_route_refresh_print(netdissect_options * ndo,const u_char * pptr,u_int len)3027 bgp_route_refresh_print(netdissect_options *ndo,
3028 const u_char *pptr, u_int len)
3029 {
3030 const struct bgp_route_refresh *bgp_route_refresh_header;
3031
3032 ND_TCHECK_LEN(pptr, BGP_ROUTE_REFRESH_SIZE);
3033
3034 /* some little sanity checking */
3035 if (len<BGP_ROUTE_REFRESH_SIZE)
3036 return;
3037
3038 bgp_route_refresh_header = (const struct bgp_route_refresh *)pptr;
3039
3040 ND_PRINT("\n\t AFI %s (%u), SAFI %s (%u)",
3041 tok2str(af_values,"Unknown",
3042 GET_BE_U_2(bgp_route_refresh_header->afi)),
3043 GET_BE_U_2(bgp_route_refresh_header->afi),
3044 tok2str(bgp_safi_values,"Unknown",
3045 GET_U_1(bgp_route_refresh_header->safi)),
3046 GET_U_1(bgp_route_refresh_header->safi));
3047
3048 if (ndo->ndo_vflag > 1) {
3049 ND_TCHECK_LEN(pptr, len);
3050 print_unknown_data(ndo, pptr, "\n\t ", len);
3051 }
3052
3053 return;
3054 trunc:
3055 nd_print_trunc(ndo);
3056 }
3057
3058 static int
bgp_pdu_print(netdissect_options * ndo,const u_char * dat,u_int length)3059 bgp_pdu_print(netdissect_options *ndo,
3060 const u_char *dat, u_int length)
3061 {
3062 const struct bgp *bgp_header;
3063 uint8_t bgp_type;
3064
3065 ND_TCHECK_LEN(dat, BGP_SIZE);
3066 bgp_header = (const struct bgp *)dat;
3067 bgp_type = GET_U_1(bgp_header->bgp_type);
3068
3069 ND_PRINT("\n\t%s Message (%u), length: %u",
3070 tok2str(bgp_msg_values, "Unknown", bgp_type),
3071 bgp_type,
3072 length);
3073
3074 switch (bgp_type) {
3075 case BGP_OPEN:
3076 bgp_open_print(ndo, dat, length);
3077 break;
3078 case BGP_UPDATE:
3079 bgp_update_print(ndo, dat, length);
3080 break;
3081 case BGP_NOTIFICATION:
3082 bgp_notification_print(ndo, dat, length);
3083 break;
3084 case BGP_KEEPALIVE:
3085 break;
3086 case BGP_ROUTE_REFRESH:
3087 bgp_route_refresh_print(ndo, dat, length);
3088 break;
3089 default:
3090 /* we have no decoder for the BGP message */
3091 ND_TCHECK_LEN(dat, length);
3092 ND_PRINT("\n\t no Message %u decoder", bgp_type);
3093 print_unknown_data(ndo, dat, "\n\t ", length);
3094 break;
3095 }
3096 return 1;
3097 trunc:
3098 nd_print_trunc(ndo);
3099 return 0;
3100 }
3101
3102 void
bgp_print(netdissect_options * ndo,const u_char * dat,u_int length _U_)3103 bgp_print(netdissect_options *ndo,
3104 const u_char *dat, u_int length _U_)
3105 {
3106 const u_char *p;
3107 const u_char *ep = ndo->ndo_snapend;
3108 const u_char *start;
3109 const u_char marker[] = {
3110 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3111 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
3112 };
3113 const struct bgp *bgp_header;
3114 uint16_t hlen;
3115
3116 ndo->ndo_protocol = "bgp";
3117 ND_PRINT(": BGP");
3118
3119 if (ndo->ndo_vflag < 1) /* lets be less chatty */
3120 return;
3121
3122 p = dat;
3123 start = p;
3124 while (p < ep) {
3125 if (!ND_TTEST_1(p))
3126 break;
3127 if (GET_U_1(p) != 0xff) {
3128 p++;
3129 continue;
3130 }
3131
3132 if (!ND_TTEST_LEN(p, sizeof(marker)))
3133 break;
3134 if (memcmp(p, marker, sizeof(marker)) != 0) {
3135 p++;
3136 continue;
3137 }
3138
3139 /* found BGP header */
3140 ND_TCHECK_LEN(p, BGP_SIZE);
3141 bgp_header = (const struct bgp *)p;
3142
3143 if (start != p)
3144 nd_print_trunc(ndo);
3145
3146 hlen = GET_BE_U_2(bgp_header->bgp_len);
3147 if (hlen < BGP_SIZE) {
3148 ND_PRINT("\nmessage length %u < %u", hlen, BGP_SIZE);
3149 nd_print_invalid(ndo);
3150 break;
3151 }
3152
3153 if (ND_TTEST_LEN(p, hlen)) {
3154 if (!bgp_pdu_print(ndo, p, hlen))
3155 return;
3156 p += hlen;
3157 start = p;
3158 } else {
3159 ND_PRINT("\n[|BGP %s]",
3160 tok2str(bgp_msg_values,
3161 "Unknown Message Type",
3162 GET_U_1(bgp_header->bgp_type)));
3163 break;
3164 }
3165 }
3166
3167 return;
3168
3169 trunc:
3170 nd_print_trunc(ndo);
3171 }
3172