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