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cd1964ff DS |
1 | /* BGP carrying label information |
2 | * Copyright (C) 2013 Cumulus Networks, Inc. | |
3 | * | |
4 | * This file is part of GNU Zebra. | |
5 | * | |
6 | * GNU Zebra is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2, or (at your option) any | |
9 | * later version. | |
10 | * | |
11 | * GNU Zebra is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
896014f4 DL |
16 | * You should have received a copy of the GNU General Public License along |
17 | * with this program; see the file COPYING; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
cd1964ff DS |
19 | */ |
20 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "command.h" | |
24 | #include "thread.h" | |
25 | #include "prefix.h" | |
26 | #include "zclient.h" | |
27 | #include "stream.h" | |
28 | #include "network.h" | |
29 | #include "log.h" | |
30 | #include "memory.h" | |
31 | #include "nexthop.h" | |
32 | #include "mpls.h" | |
33 | ||
34 | #include "bgpd/bgpd.h" | |
35 | #include "bgpd/bgp_table.h" | |
36 | #include "bgpd/bgp_route.h" | |
37 | #include "bgpd/bgp_attr.h" | |
38 | #include "bgpd/bgp_label.h" | |
39 | #include "bgpd/bgp_packet.h" | |
40 | #include "bgpd/bgp_debug.h" | |
14454c9f | 41 | #include "bgpd/bgp_errors.h" |
cd1964ff DS |
42 | |
43 | extern struct zclient *zclient; | |
44 | ||
d62a17ae | 45 | int bgp_parse_fec_update(void) |
cd1964ff | 46 | { |
d62a17ae | 47 | struct stream *s; |
48 | struct bgp_node *rn; | |
49 | struct bgp *bgp; | |
50 | struct bgp_table *table; | |
51 | struct prefix p; | |
d7c0a89a | 52 | uint32_t label; |
d62a17ae | 53 | afi_t afi; |
54 | safi_t safi; | |
55 | ||
56 | s = zclient->ibuf; | |
57 | ||
58 | memset(&p, 0, sizeof(struct prefix)); | |
59 | p.family = stream_getw(s); | |
60 | p.prefixlen = stream_getc(s); | |
a85297a7 | 61 | stream_get(p.u.val, s, PSIZE(p.prefixlen)); |
d62a17ae | 62 | label = stream_getl(s); |
63 | ||
64 | /* hack for the bgp instance & SAFI = have to send/receive it */ | |
65 | afi = family2afi(p.family); | |
66 | safi = SAFI_UNICAST; | |
67 | bgp = bgp_get_default(); | |
68 | if (!bgp) { | |
69 | zlog_debug("no default bgp instance"); | |
70 | return -1; | |
71 | } | |
72 | ||
73 | table = bgp->rib[afi][safi]; | |
74 | if (!table) { | |
75 | zlog_debug("no %u unicast table", p.family); | |
76 | return -1; | |
77 | } | |
78 | rn = bgp_node_lookup(table, &p); | |
79 | if (!rn) { | |
80 | zlog_debug("no node for the prefix"); | |
81 | return -1; | |
82 | } | |
83 | ||
84 | /* treat it as implicit withdraw - the label is invalid */ | |
85 | if (label == MPLS_INVALID_LABEL) | |
86 | bgp_unset_valid_label(&rn->local_label); | |
87 | else { | |
88 | label_ntop(label, 1, &rn->local_label); | |
89 | bgp_set_valid_label(&rn->local_label); | |
90 | } | |
91 | SET_FLAG(rn->flags, BGP_NODE_LABEL_CHANGED); | |
92 | bgp_unlock_node(rn); | |
93 | bgp_process(bgp, rn, afi, safi); | |
94 | return 1; | |
cd1964ff DS |
95 | } |
96 | ||
d62a17ae | 97 | mpls_label_t bgp_adv_label(struct bgp_node *rn, struct bgp_info *ri, |
98 | struct peer *to, afi_t afi, safi_t safi) | |
cd1964ff | 99 | { |
d62a17ae | 100 | struct peer *from; |
101 | mpls_label_t remote_label; | |
102 | int reflect; | |
cd1964ff | 103 | |
d62a17ae | 104 | if (!rn || !ri || !to) |
105 | return MPLS_INVALID_LABEL; | |
cd1964ff | 106 | |
b57ba6d2 | 107 | remote_label = ri->extra ? ri->extra->label[0] : MPLS_INVALID_LABEL; |
d62a17ae | 108 | from = ri->peer; |
109 | reflect = | |
110 | ((from->sort == BGP_PEER_IBGP) && (to->sort == BGP_PEER_IBGP)); | |
cd1964ff | 111 | |
d62a17ae | 112 | if (reflect |
113 | && !CHECK_FLAG(to->af_flags[afi][safi], | |
114 | PEER_FLAG_FORCE_NEXTHOP_SELF)) | |
115 | return remote_label; | |
cd1964ff | 116 | |
d62a17ae | 117 | if (CHECK_FLAG(to->af_flags[afi][safi], PEER_FLAG_NEXTHOP_UNCHANGED)) |
118 | return remote_label; | |
cd1964ff | 119 | |
d62a17ae | 120 | return rn->local_label; |
cd1964ff DS |
121 | } |
122 | ||
d62a17ae | 123 | void bgp_reg_dereg_for_label(struct bgp_node *rn, struct bgp_info *ri, int reg) |
cd1964ff | 124 | { |
d62a17ae | 125 | struct stream *s; |
126 | struct prefix *p; | |
127 | int command; | |
d7c0a89a | 128 | uint16_t flags = 0; |
d62a17ae | 129 | size_t flags_pos = 0; |
130 | ||
131 | /* Check socket. */ | |
132 | if (!zclient || zclient->sock < 0) | |
133 | return; | |
134 | ||
135 | p = &(rn->p); | |
136 | s = zclient->obuf; | |
137 | stream_reset(s); | |
138 | command = (reg) ? ZEBRA_FEC_REGISTER : ZEBRA_FEC_UNREGISTER; | |
139 | zclient_create_header(s, command, VRF_DEFAULT); | |
140 | flags_pos = stream_get_endp(s); /* save position of 'flags' */ | |
141 | stream_putw(s, flags); /* initial flags */ | |
142 | stream_putw(s, PREFIX_FAMILY(p)); | |
143 | stream_put_prefix(s, p); | |
144 | if (reg) { | |
145 | assert(ri); | |
146 | if (ri->attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID)) { | |
147 | if (ri->attr->label_index != BGP_INVALID_LABEL_INDEX) { | |
148 | flags |= ZEBRA_FEC_REGISTER_LABEL_INDEX; | |
149 | stream_putl(s, ri->attr->label_index); | |
150 | } | |
151 | } | |
152 | SET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL); | |
153 | } else | |
154 | UNSET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL); | |
155 | ||
156 | /* Set length and flags */ | |
157 | stream_putw_at(s, 0, stream_get_endp(s)); | |
e0b84ba1 DS |
158 | |
159 | /* | |
160 | * We only need to write new flags if this is a register | |
161 | */ | |
162 | if (reg) | |
163 | stream_putw_at(s, flags_pos, flags); | |
d62a17ae | 164 | |
165 | zclient_send_message(zclient); | |
cd1964ff DS |
166 | } |
167 | ||
d7c0a89a | 168 | static int bgp_nlri_get_labels(struct peer *peer, uint8_t *pnt, uint8_t plen, |
d62a17ae | 169 | mpls_label_t *label) |
cd1964ff | 170 | { |
d7c0a89a QY |
171 | uint8_t *data = pnt; |
172 | uint8_t *lim = pnt + plen; | |
173 | uint8_t llen = 0; | |
174 | uint8_t label_depth = 0; | |
d62a17ae | 175 | |
176 | for (; data < lim; data += BGP_LABEL_BYTES) { | |
177 | memcpy(label, data, BGP_LABEL_BYTES); | |
178 | llen += BGP_LABEL_BYTES; | |
179 | ||
180 | bgp_set_valid_label(label); | |
181 | label_depth += 1; | |
182 | ||
183 | if (bgp_is_withdraw_label(label) || label_bos(label)) | |
184 | break; | |
185 | } | |
186 | ||
187 | /* If we RX multiple labels we will end up keeping only the last | |
188 | * one. We do not yet support a label stack greater than 1. */ | |
189 | if (label_depth > 1) | |
190 | zlog_warn("%s rcvd UPDATE with label stack %d deep", peer->host, | |
191 | label_depth); | |
192 | ||
193 | if (!(bgp_is_withdraw_label(label) || label_bos(label))) | |
194 | zlog_warn( | |
195 | "%s rcvd UPDATE with invalid label stack - no bottom of stack", | |
196 | peer->host); | |
197 | ||
198 | return llen; | |
cd1964ff DS |
199 | } |
200 | ||
d62a17ae | 201 | int bgp_nlri_parse_label(struct peer *peer, struct attr *attr, |
202 | struct bgp_nlri *packet) | |
cd1964ff | 203 | { |
d7c0a89a QY |
204 | uint8_t *pnt; |
205 | uint8_t *lim; | |
d62a17ae | 206 | struct prefix p; |
207 | int psize = 0; | |
208 | int prefixlen; | |
209 | afi_t afi; | |
210 | safi_t safi; | |
211 | int addpath_encoded; | |
d7c0a89a | 212 | uint32_t addpath_id; |
d62a17ae | 213 | mpls_label_t label = MPLS_INVALID_LABEL; |
d7c0a89a | 214 | uint8_t llen; |
d62a17ae | 215 | |
d62a17ae | 216 | pnt = packet->nlri; |
217 | lim = pnt + packet->length; | |
218 | afi = packet->afi; | |
219 | safi = packet->safi; | |
220 | addpath_id = 0; | |
221 | ||
222 | addpath_encoded = | |
223 | (CHECK_FLAG(peer->af_cap[afi][safi], PEER_CAP_ADDPATH_AF_RX_ADV) | |
224 | && CHECK_FLAG(peer->af_cap[afi][safi], | |
225 | PEER_CAP_ADDPATH_AF_TX_RCV)); | |
226 | ||
227 | for (; pnt < lim; pnt += psize) { | |
228 | /* Clear prefix structure. */ | |
229 | memset(&p, 0, sizeof(struct prefix)); | |
d62a17ae | 230 | |
231 | if (addpath_encoded) { | |
232 | ||
233 | /* When packet overflow occurs return immediately. */ | |
234 | if (pnt + BGP_ADDPATH_ID_LEN > lim) | |
235 | return -1; | |
236 | ||
237 | addpath_id = ntohl(*((uint32_t *)pnt)); | |
238 | pnt += BGP_ADDPATH_ID_LEN; | |
239 | } | |
240 | ||
241 | /* Fetch prefix length. */ | |
242 | prefixlen = *pnt++; | |
243 | p.family = afi2family(packet->afi); | |
244 | psize = PSIZE(prefixlen); | |
245 | ||
246 | /* sanity check against packet data */ | |
247 | if ((pnt + psize) > lim) { | |
af4c2728 | 248 | flog_err( |
14454c9f | 249 | BGP_ERR_UPDATE_RCV, |
d62a17ae | 250 | "%s [Error] Update packet error / L-U (prefix length %d exceeds packet size %u)", |
251 | peer->host, prefixlen, (uint)(lim - pnt)); | |
252 | return -1; | |
253 | } | |
254 | ||
255 | /* Fill in the labels */ | |
256 | llen = bgp_nlri_get_labels(peer, pnt, psize, &label); | |
257 | p.prefixlen = prefixlen - BSIZE(llen); | |
258 | ||
259 | /* There needs to be at least one label */ | |
260 | if (prefixlen < 24) { | |
af4c2728 | 261 | flog_err(BGP_ERR_UPDATE_RCV, |
14454c9f DS |
262 | "%s [Error] Update packet error" |
263 | " (wrong label length %d)", | |
264 | peer->host, prefixlen); | |
d62a17ae | 265 | bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR, |
266 | BGP_NOTIFY_UPDATE_INVAL_NETWORK); | |
267 | return -1; | |
268 | } | |
269 | ||
270 | if ((afi == AFI_IP && p.prefixlen > 32) | |
271 | || (afi == AFI_IP6 && p.prefixlen > 128)) | |
272 | return -1; | |
273 | ||
274 | /* Fetch prefix from NLRI packet */ | |
275 | memcpy(&p.u.prefix, pnt + llen, psize - llen); | |
276 | ||
277 | /* Check address. */ | |
278 | if (afi == AFI_IP && safi == SAFI_LABELED_UNICAST) { | |
279 | if (IN_CLASSD(ntohl(p.u.prefix4.s_addr))) { | |
280 | /* From RFC4271 Section 6.3: | |
281 | * | |
282 | * If a prefix in the NLRI field is semantically | |
283 | * incorrect | |
284 | * (e.g., an unexpected multicast IP address), | |
285 | * an error SHOULD | |
286 | * be logged locally, and the prefix SHOULD be | |
287 | * ignored. | |
9d303b37 | 288 | */ |
af4c2728 | 289 | flog_err( |
14454c9f | 290 | BGP_ERR_UPDATE_RCV, |
d62a17ae | 291 | "%s: IPv4 labeled-unicast NLRI is multicast address %s, ignoring", |
292 | peer->host, inet_ntoa(p.u.prefix4)); | |
293 | continue; | |
294 | } | |
295 | } | |
296 | ||
297 | /* Check address. */ | |
298 | if (afi == AFI_IP6 && safi == SAFI_LABELED_UNICAST) { | |
299 | if (IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)) { | |
300 | char buf[BUFSIZ]; | |
301 | ||
af4c2728 | 302 | flog_err( |
14454c9f | 303 | BGP_ERR_UPDATE_RCV, |
d62a17ae | 304 | "%s: IPv6 labeled-unicast NLRI is link-local address %s, ignoring", |
305 | peer->host, | |
306 | inet_ntop(AF_INET6, &p.u.prefix6, buf, | |
307 | BUFSIZ)); | |
308 | ||
309 | continue; | |
310 | } | |
311 | ||
312 | if (IN6_IS_ADDR_MULTICAST(&p.u.prefix6)) { | |
313 | char buf[BUFSIZ]; | |
314 | ||
af4c2728 | 315 | flog_err( |
14454c9f | 316 | BGP_ERR_UPDATE_RCV, |
d62a17ae | 317 | "%s: IPv6 unicast NLRI is multicast address %s, ignoring", |
318 | peer->host, | |
319 | inet_ntop(AF_INET6, &p.u.prefix6, buf, | |
320 | BUFSIZ)); | |
321 | ||
322 | continue; | |
323 | } | |
324 | } | |
325 | ||
326 | if (attr) { | |
327 | bgp_update(peer, &p, addpath_id, attr, packet->afi, | |
328 | SAFI_UNICAST, ZEBRA_ROUTE_BGP, | |
b57ba6d2 | 329 | BGP_ROUTE_NORMAL, NULL, &label, 1, 0, NULL); |
d62a17ae | 330 | } else { |
331 | bgp_withdraw(peer, &p, addpath_id, attr, packet->afi, | |
332 | SAFI_UNICAST, ZEBRA_ROUTE_BGP, | |
b57ba6d2 | 333 | BGP_ROUTE_NORMAL, NULL, &label, 1, NULL); |
d62a17ae | 334 | } |
335 | } | |
336 | ||
337 | /* Packet length consistency check. */ | |
338 | if (pnt != lim) { | |
af4c2728 | 339 | flog_err( |
14454c9f | 340 | BGP_ERR_UPDATE_RCV, |
d62a17ae | 341 | "%s [Error] Update packet error / L-U (%zu data remaining after parsing)", |
342 | peer->host, lim - pnt); | |
343 | return -1; | |
344 | } | |
345 | ||
346 | return 0; | |
cd1964ff | 347 | } |