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1 | /* BGP network related fucntions | |
2 | * Copyright (C) 1999 Kunihiro Ishiguro | |
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 | * | |
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 | |
19 | */ | |
20 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "thread.h" | |
24 | #include "sockunion.h" | |
25 | #include "sockopt.h" | |
26 | #include "memory.h" | |
27 | #include "log.h" | |
28 | #include "if.h" | |
29 | #include "prefix.h" | |
30 | #include "command.h" | |
31 | #include "privs.h" | |
32 | #include "linklist.h" | |
33 | #include "network.h" | |
34 | #include "queue.h" | |
35 | #include "hash.h" | |
36 | #include "filter.h" | |
37 | #include "ns.h" | |
38 | #include "lib_errors.h" | |
39 | #include "nexthop.h" | |
40 | ||
41 | #include "bgpd/bgpd.h" | |
42 | #include "bgpd/bgp_open.h" | |
43 | #include "bgpd/bgp_fsm.h" | |
44 | #include "bgpd/bgp_attr.h" | |
45 | #include "bgpd/bgp_debug.h" | |
46 | #include "bgpd/bgp_errors.h" | |
47 | #include "bgpd/bgp_network.h" | |
48 | #include "bgpd/bgp_zebra.h" | |
49 | #include "bgpd/bgp_nht.h" | |
50 | ||
51 | extern struct zebra_privs_t bgpd_privs; | |
52 | ||
53 | static char *bgp_get_bound_name(struct peer *peer); | |
54 | ||
55 | void bgp_dump_listener_info(struct vty *vty) | |
56 | { | |
57 | struct listnode *node; | |
58 | struct bgp_listener *listener; | |
59 | ||
60 | vty_out(vty, "Name fd Address\n"); | |
61 | vty_out(vty, "---------------------------\n"); | |
62 | for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) { | |
63 | char buf[SU_ADDRSTRLEN]; | |
64 | ||
65 | vty_out(vty, "%-16s %d %s\n", | |
66 | listener->name ? listener->name : VRF_DEFAULT_NAME, | |
67 | listener->fd, | |
68 | sockunion2str(&listener->su, buf, sizeof(buf))); | |
69 | } | |
70 | } | |
71 | ||
72 | /* | |
73 | * Set MD5 key for the socket, for the given IPv4 peer address. | |
74 | * If the password is NULL or zero-length, the option will be disabled. | |
75 | */ | |
76 | static int bgp_md5_set_socket(int socket, union sockunion *su, | |
77 | uint16_t prefixlen, const char *password) | |
78 | { | |
79 | int ret = -1; | |
80 | int en = ENOSYS; | |
81 | #if HAVE_DECL_TCP_MD5SIG | |
82 | union sockunion su2; | |
83 | #endif /* HAVE_TCP_MD5SIG */ | |
84 | ||
85 | assert(socket >= 0); | |
86 | ||
87 | #if HAVE_DECL_TCP_MD5SIG | |
88 | /* Ensure there is no extraneous port information. */ | |
89 | memcpy(&su2, su, sizeof(union sockunion)); | |
90 | if (su2.sa.sa_family == AF_INET) | |
91 | su2.sin.sin_port = 0; | |
92 | else | |
93 | su2.sin6.sin6_port = 0; | |
94 | ||
95 | /* For addresses, use the non-extended signature functionality */ | |
96 | if ((su2.sa.sa_family == AF_INET && prefixlen == IPV4_MAX_BITLEN) | |
97 | || (su2.sa.sa_family == AF_INET6 && prefixlen == IPV6_MAX_BITLEN)) | |
98 | ret = sockopt_tcp_signature(socket, &su2, password); | |
99 | else | |
100 | ret = sockopt_tcp_signature_ext(socket, &su2, prefixlen, | |
101 | password); | |
102 | en = errno; | |
103 | #endif /* HAVE_TCP_MD5SIG */ | |
104 | ||
105 | if (ret < 0) { | |
106 | char sabuf[SU_ADDRSTRLEN]; | |
107 | sockunion2str(su, sabuf, sizeof(sabuf)); | |
108 | ||
109 | switch (ret) { | |
110 | case -2: | |
111 | flog_warn( | |
112 | EC_BGP_NO_TCP_MD5, | |
113 | "Unable to set TCP MD5 option on socket for peer %s (sock=%d): This platform does not support MD5 auth for prefixes", | |
114 | sabuf, socket); | |
115 | break; | |
116 | default: | |
117 | flog_warn( | |
118 | EC_BGP_NO_TCP_MD5, | |
119 | "Unable to set TCP MD5 option on socket for peer %s (sock=%d): %s", | |
120 | sabuf, socket, safe_strerror(en)); | |
121 | } | |
122 | } | |
123 | ||
124 | return ret; | |
125 | } | |
126 | ||
127 | /* Helper for bgp_connect */ | |
128 | static int bgp_md5_set_connect(int socket, union sockunion *su, | |
129 | uint16_t prefixlen, const char *password) | |
130 | { | |
131 | int ret = -1; | |
132 | ||
133 | #if HAVE_DECL_TCP_MD5SIG | |
134 | frr_with_privs(&bgpd_privs) { | |
135 | ret = bgp_md5_set_socket(socket, su, prefixlen, password); | |
136 | } | |
137 | #endif /* HAVE_TCP_MD5SIG */ | |
138 | ||
139 | return ret; | |
140 | } | |
141 | ||
142 | static int bgp_md5_set_password(struct peer *peer, const char *password) | |
143 | { | |
144 | struct listnode *node; | |
145 | int ret = 0; | |
146 | struct bgp_listener *listener; | |
147 | ||
148 | /* | |
149 | * Set or unset the password on the listen socket(s). Outbound | |
150 | * connections are taken care of in bgp_connect() below. | |
151 | */ | |
152 | frr_with_privs(&bgpd_privs) { | |
153 | for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) | |
154 | if (listener->su.sa.sa_family == | |
155 | peer->su.sa.sa_family) { | |
156 | uint16_t prefixlen = | |
157 | peer->su.sa.sa_family == AF_INET | |
158 | ? IPV4_MAX_BITLEN | |
159 | : IPV6_MAX_BITLEN; | |
160 | ||
161 | /* | |
162 | * if we have stored a BGP vrf instance in the | |
163 | * listener it must match the bgp instance in | |
164 | * the peer otherwise the peer bgp instance | |
165 | * must be the default vrf or a view instance | |
166 | */ | |
167 | if (!listener->bgp) { | |
168 | if (peer->bgp->vrf_id != VRF_DEFAULT) | |
169 | continue; | |
170 | } else if (listener->bgp != peer->bgp) | |
171 | continue; | |
172 | ||
173 | ret = bgp_md5_set_socket(listener->fd, | |
174 | &peer->su, prefixlen, | |
175 | password); | |
176 | break; | |
177 | } | |
178 | } | |
179 | return ret; | |
180 | } | |
181 | ||
182 | int bgp_md5_set_prefix(struct bgp *bgp, struct prefix *p, const char *password) | |
183 | { | |
184 | int ret = 0; | |
185 | union sockunion su; | |
186 | struct listnode *node; | |
187 | struct bgp_listener *listener; | |
188 | ||
189 | /* Set or unset the password on the listen socket(s). */ | |
190 | frr_with_privs(&bgpd_privs) { | |
191 | for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) | |
192 | if (listener->su.sa.sa_family == p->family | |
193 | && ((bgp->vrf_id == VRF_DEFAULT) | |
194 | || (listener->bgp == bgp))) { | |
195 | prefix2sockunion(p, &su); | |
196 | ret = bgp_md5_set_socket(listener->fd, &su, | |
197 | p->prefixlen, | |
198 | password); | |
199 | break; | |
200 | } | |
201 | } | |
202 | ||
203 | return ret; | |
204 | } | |
205 | ||
206 | int bgp_md5_unset_prefix(struct bgp *bgp, struct prefix *p) | |
207 | { | |
208 | return bgp_md5_set_prefix(bgp, p, NULL); | |
209 | } | |
210 | ||
211 | int bgp_md5_set(struct peer *peer) | |
212 | { | |
213 | /* Set the password from listen socket. */ | |
214 | return bgp_md5_set_password(peer, peer->password); | |
215 | } | |
216 | ||
217 | int bgp_md5_unset(struct peer *peer) | |
218 | { | |
219 | /* Unset the password from listen socket. */ | |
220 | return bgp_md5_set_password(peer, NULL); | |
221 | } | |
222 | ||
223 | int bgp_set_socket_ttl(struct peer *peer, int bgp_sock) | |
224 | { | |
225 | int ret = 0; | |
226 | ||
227 | /* In case of peer is EBGP, we should set TTL for this connection. */ | |
228 | if (!peer->gtsm_hops && (peer_sort_lookup(peer) == BGP_PEER_EBGP)) { | |
229 | ret = sockopt_ttl(peer->su.sa.sa_family, bgp_sock, peer->ttl); | |
230 | if (ret) { | |
231 | flog_err( | |
232 | EC_LIB_SOCKET, | |
233 | "%s: Can't set TxTTL on peer (rtrid %pI4) socket, err = %d", | |
234 | __func__, &peer->remote_id, errno); | |
235 | return ret; | |
236 | } | |
237 | } else if (peer->gtsm_hops) { | |
238 | /* On Linux, setting minttl without setting ttl seems to mess | |
239 | with the | |
240 | outgoing ttl. Therefore setting both. | |
241 | */ | |
242 | ret = sockopt_ttl(peer->su.sa.sa_family, bgp_sock, MAXTTL); | |
243 | if (ret) { | |
244 | flog_err( | |
245 | EC_LIB_SOCKET, | |
246 | "%s: Can't set TxTTL on peer (rtrid %pI4) socket, err = %d", | |
247 | __func__, &peer->remote_id, errno); | |
248 | return ret; | |
249 | } | |
250 | ret = sockopt_minttl(peer->su.sa.sa_family, bgp_sock, | |
251 | MAXTTL + 1 - peer->gtsm_hops); | |
252 | if (ret) { | |
253 | flog_err( | |
254 | EC_LIB_SOCKET, | |
255 | "%s: Can't set MinTTL on peer (rtrid %pI4) socket, err = %d", | |
256 | __func__, &peer->remote_id, errno); | |
257 | return ret; | |
258 | } | |
259 | } | |
260 | ||
261 | return ret; | |
262 | } | |
263 | ||
264 | /* | |
265 | * Obtain the BGP instance that the incoming connection should be processed | |
266 | * against. This is important because more than one VRF could be using the | |
267 | * same IP address space. The instance is got by obtaining the device to | |
268 | * which the incoming connection is bound to. This could either be a VRF | |
269 | * or it could be an interface, which in turn determines the VRF. | |
270 | */ | |
271 | static int bgp_get_instance_for_inc_conn(int sock, struct bgp **bgp_inst) | |
272 | { | |
273 | #ifndef SO_BINDTODEVICE | |
274 | /* only Linux has SO_BINDTODEVICE, but we're in Linux-specific code here | |
275 | * anyway since the assumption is that the interface name returned by | |
276 | * getsockopt() is useful in identifying the VRF, particularly with | |
277 | * Linux's | |
278 | * VRF l3master device. The whole mechanism is specific to Linux, so... | |
279 | * when other platforms add VRF support, this will need handling here as | |
280 | * well. (or, some restructuring) */ | |
281 | *bgp_inst = bgp_get_default(); | |
282 | return !*bgp_inst; | |
283 | ||
284 | #else | |
285 | char name[VRF_NAMSIZ + 1]; | |
286 | socklen_t name_len = VRF_NAMSIZ; | |
287 | struct bgp *bgp; | |
288 | int rc; | |
289 | struct listnode *node, *nnode; | |
290 | ||
291 | *bgp_inst = NULL; | |
292 | name[0] = '\0'; | |
293 | rc = getsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, name, &name_len); | |
294 | if (rc != 0) { | |
295 | #if defined(HAVE_CUMULUS) | |
296 | flog_err(EC_LIB_SOCKET, | |
297 | "[Error] BGP SO_BINDTODEVICE get failed (%s), sock %d", | |
298 | safe_strerror(errno), sock); | |
299 | return -1; | |
300 | #endif | |
301 | } | |
302 | ||
303 | if (!strlen(name)) { | |
304 | *bgp_inst = bgp_get_default(); | |
305 | return 0; /* default instance. */ | |
306 | } | |
307 | ||
308 | /* First try match to instance; if that fails, check for interfaces. */ | |
309 | bgp = bgp_lookup_by_name(name); | |
310 | if (bgp) { | |
311 | if (!bgp->vrf_id) // unexpected | |
312 | return -1; | |
313 | *bgp_inst = bgp; | |
314 | return 0; | |
315 | } | |
316 | ||
317 | /* TODO - This will be optimized once interfaces move into the NS */ | |
318 | for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp)) { | |
319 | struct interface *ifp; | |
320 | ||
321 | if (bgp->inst_type == BGP_INSTANCE_TYPE_VIEW) | |
322 | continue; | |
323 | ||
324 | ifp = if_lookup_by_name(name, bgp->vrf_id); | |
325 | if (ifp) { | |
326 | *bgp_inst = bgp; | |
327 | return 0; | |
328 | } | |
329 | } | |
330 | ||
331 | /* We didn't match to either an instance or an interface. */ | |
332 | return -1; | |
333 | #endif | |
334 | } | |
335 | ||
336 | static void bgp_socket_set_buffer_size(const int fd) | |
337 | { | |
338 | if (getsockopt_so_sendbuf(fd) < (int)bm->socket_buffer) | |
339 | setsockopt_so_sendbuf(fd, bm->socket_buffer); | |
340 | if (getsockopt_so_recvbuf(fd) < (int)bm->socket_buffer) | |
341 | setsockopt_so_recvbuf(fd, bm->socket_buffer); | |
342 | } | |
343 | ||
344 | /* Accept bgp connection. */ | |
345 | static void bgp_accept(struct thread *thread) | |
346 | { | |
347 | int bgp_sock; | |
348 | int accept_sock; | |
349 | union sockunion su; | |
350 | struct bgp_listener *listener = THREAD_ARG(thread); | |
351 | struct peer *peer; | |
352 | struct peer *peer1; | |
353 | char buf[SU_ADDRSTRLEN]; | |
354 | struct bgp *bgp = NULL; | |
355 | ||
356 | sockunion_init(&su); | |
357 | ||
358 | bgp = bgp_lookup_by_name(listener->name); | |
359 | ||
360 | /* Register accept thread. */ | |
361 | accept_sock = THREAD_FD(thread); | |
362 | if (accept_sock < 0) { | |
363 | flog_err_sys(EC_LIB_SOCKET, | |
364 | "[Error] BGP accept socket fd is negative: %d", | |
365 | accept_sock); | |
366 | return; | |
367 | } | |
368 | ||
369 | thread_add_read(bm->master, bgp_accept, listener, accept_sock, | |
370 | &listener->thread); | |
371 | ||
372 | /* Accept client connection. */ | |
373 | bgp_sock = sockunion_accept(accept_sock, &su); | |
374 | int save_errno = errno; | |
375 | if (bgp_sock < 0) { | |
376 | if (save_errno == EINVAL) { | |
377 | struct vrf *vrf = | |
378 | bgp ? vrf_lookup_by_id(bgp->vrf_id) : NULL; | |
379 | ||
380 | /* | |
381 | * It appears that sometimes, when VRFs are deleted on | |
382 | * the system, it takes a little while for us to get | |
383 | * notified about that. In the meantime we endlessly | |
384 | * loop on accept(), because the socket, having been | |
385 | * bound to a now-deleted VRF device, is in some weird | |
386 | * state which causes accept() to fail. | |
387 | * | |
388 | * To avoid this, if we see accept() fail with EINVAL, | |
389 | * we cancel ourselves and trust that when the VRF | |
390 | * deletion notification comes in the event handler for | |
391 | * that will take care of cleaning us up. | |
392 | */ | |
393 | flog_err_sys( | |
394 | EC_LIB_SOCKET, | |
395 | "[Error] accept() failed with error \"%s\" on BGP listener socket %d for BGP instance in VRF \"%s\"; refreshing socket", | |
396 | safe_strerror(save_errno), accept_sock, | |
397 | VRF_LOGNAME(vrf)); | |
398 | THREAD_OFF(listener->thread); | |
399 | } else { | |
400 | flog_err_sys( | |
401 | EC_LIB_SOCKET, | |
402 | "[Error] BGP socket accept failed (%s); retrying", | |
403 | safe_strerror(save_errno)); | |
404 | } | |
405 | return; | |
406 | } | |
407 | set_nonblocking(bgp_sock); | |
408 | ||
409 | /* Obtain BGP instance this connection is meant for. | |
410 | * - if it is a VRF netns sock, then BGP is in listener structure | |
411 | * - otherwise, the bgp instance need to be demultiplexed | |
412 | */ | |
413 | if (listener->bgp) | |
414 | bgp = listener->bgp; | |
415 | else if (bgp_get_instance_for_inc_conn(bgp_sock, &bgp)) { | |
416 | if (bgp_debug_neighbor_events(NULL)) | |
417 | zlog_debug( | |
418 | "[Event] Could not get instance for incoming conn from %s", | |
419 | inet_sutop(&su, buf)); | |
420 | close(bgp_sock); | |
421 | return; | |
422 | } | |
423 | ||
424 | bgp_socket_set_buffer_size(bgp_sock); | |
425 | ||
426 | /* Check remote IP address */ | |
427 | peer1 = peer_lookup(bgp, &su); | |
428 | ||
429 | if (!peer1) { | |
430 | peer1 = peer_lookup_dynamic_neighbor(bgp, &su); | |
431 | if (peer1) { | |
432 | /* Dynamic neighbor has been created, let it proceed */ | |
433 | peer1->fd = bgp_sock; | |
434 | ||
435 | /* Set the user configured MSS to TCP socket */ | |
436 | if (CHECK_FLAG(peer1->flags, PEER_FLAG_TCP_MSS)) | |
437 | sockopt_tcp_mss_set(bgp_sock, peer1->tcp_mss); | |
438 | ||
439 | bgp_fsm_change_status(peer1, Active); | |
440 | BGP_TIMER_OFF( | |
441 | peer1->t_start); /* created in peer_create() */ | |
442 | ||
443 | if (peer_active(peer1)) { | |
444 | if (CHECK_FLAG(peer1->flags, | |
445 | PEER_FLAG_TIMER_DELAYOPEN)) | |
446 | BGP_EVENT_ADD( | |
447 | peer1, | |
448 | TCP_connection_open_w_delay); | |
449 | else | |
450 | BGP_EVENT_ADD(peer1, | |
451 | TCP_connection_open); | |
452 | } | |
453 | ||
454 | return; | |
455 | } | |
456 | } | |
457 | ||
458 | if (!peer1) { | |
459 | if (bgp_debug_neighbor_events(NULL)) { | |
460 | zlog_debug( | |
461 | "[Event] %s connection rejected(%s:%u:%s) - not configured and not valid for dynamic", | |
462 | inet_sutop(&su, buf), bgp->name_pretty, bgp->as, | |
463 | VRF_LOGNAME(vrf_lookup_by_id(bgp->vrf_id))); | |
464 | } | |
465 | close(bgp_sock); | |
466 | return; | |
467 | } | |
468 | ||
469 | if (CHECK_FLAG(peer1->flags, PEER_FLAG_SHUTDOWN) | |
470 | || CHECK_FLAG(peer1->bgp->flags, BGP_FLAG_SHUTDOWN)) { | |
471 | if (bgp_debug_neighbor_events(peer1)) | |
472 | zlog_debug( | |
473 | "[Event] connection from %s rejected(%s:%u:%s) due to admin shutdown", | |
474 | inet_sutop(&su, buf), bgp->name_pretty, bgp->as, | |
475 | VRF_LOGNAME(vrf_lookup_by_id(bgp->vrf_id))); | |
476 | close(bgp_sock); | |
477 | return; | |
478 | } | |
479 | ||
480 | /* | |
481 | * Do not accept incoming connections in Clearing state. This can result | |
482 | * in incorect state transitions - e.g., the connection goes back to | |
483 | * Established and then the Clearing_Completed event is generated. Also, | |
484 | * block incoming connection in Deleted state. | |
485 | */ | |
486 | if (peer1->status == Clearing || peer1->status == Deleted) { | |
487 | if (bgp_debug_neighbor_events(peer1)) | |
488 | zlog_debug( | |
489 | "[Event] Closing incoming conn for %s (%p) state %d", | |
490 | peer1->host, peer1, peer1->status); | |
491 | close(bgp_sock); | |
492 | return; | |
493 | } | |
494 | ||
495 | /* Check that at least one AF is activated for the peer. */ | |
496 | if (!peer_active(peer1)) { | |
497 | if (bgp_debug_neighbor_events(peer1)) | |
498 | zlog_debug( | |
499 | "%s - incoming conn rejected - no AF activated for peer", | |
500 | peer1->host); | |
501 | close(bgp_sock); | |
502 | return; | |
503 | } | |
504 | ||
505 | /* Do not try to reconnect if the peer reached maximum | |
506 | * prefixes, restart timer is still running or the peer | |
507 | * is shutdown. | |
508 | */ | |
509 | if (BGP_PEER_START_SUPPRESSED(peer1)) { | |
510 | if (bgp_debug_neighbor_events(peer1)) | |
511 | zlog_debug( | |
512 | "[Event] Incoming BGP connection rejected from %s due to maximum-prefix or shutdown", | |
513 | peer1->host); | |
514 | close(bgp_sock); | |
515 | return; | |
516 | } | |
517 | ||
518 | if (bgp_debug_neighbor_events(peer1)) | |
519 | zlog_debug("[Event] BGP connection from host %s fd %d", | |
520 | inet_sutop(&su, buf), bgp_sock); | |
521 | ||
522 | if (peer1->doppelganger) { | |
523 | /* We have an existing connection. Kill the existing one and run | |
524 | with this one. | |
525 | */ | |
526 | if (bgp_debug_neighbor_events(peer1)) | |
527 | zlog_debug( | |
528 | "[Event] New active connection from peer %s, Killing previous active connection", | |
529 | peer1->host); | |
530 | peer_delete(peer1->doppelganger); | |
531 | } | |
532 | ||
533 | if (bgp_set_socket_ttl(peer1, bgp_sock) < 0) | |
534 | if (bgp_debug_neighbor_events(peer1)) | |
535 | zlog_debug( | |
536 | "[Event] Unable to set min/max TTL on peer %s, Continuing", | |
537 | peer1->host); | |
538 | ||
539 | peer = peer_create(&su, peer1->conf_if, peer1->bgp, peer1->local_as, | |
540 | peer1->as, peer1->as_type, NULL); | |
541 | hash_release(peer->bgp->peerhash, peer); | |
542 | hash_get(peer->bgp->peerhash, peer, hash_alloc_intern); | |
543 | ||
544 | peer_xfer_config(peer, peer1); | |
545 | bgp_peer_gr_flags_update(peer); | |
546 | ||
547 | BGP_GR_ROUTER_DETECT_AND_SEND_CAPABILITY_TO_ZEBRA(peer->bgp, | |
548 | peer->bgp->peer); | |
549 | ||
550 | if (bgp_peer_gr_mode_get(peer) == PEER_DISABLE) { | |
551 | ||
552 | UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE); | |
553 | ||
554 | if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) { | |
555 | peer_nsf_stop(peer); | |
556 | } | |
557 | } | |
558 | ||
559 | UNSET_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE); | |
560 | ||
561 | peer->doppelganger = peer1; | |
562 | peer1->doppelganger = peer; | |
563 | peer->fd = bgp_sock; | |
564 | frr_with_privs(&bgpd_privs) { | |
565 | vrf_bind(peer->bgp->vrf_id, bgp_sock, bgp_get_bound_name(peer)); | |
566 | } | |
567 | bgp_peer_reg_with_nht(peer); | |
568 | bgp_fsm_change_status(peer, Active); | |
569 | BGP_TIMER_OFF(peer->t_start); /* created in peer_create() */ | |
570 | ||
571 | SET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER); | |
572 | /* Make dummy peer until read Open packet. */ | |
573 | if (peer_established(peer1) | |
574 | && CHECK_FLAG(peer1->sflags, PEER_STATUS_NSF_MODE)) { | |
575 | /* If we have an existing established connection with graceful | |
576 | * restart | |
577 | * capability announced with one or more address families, then | |
578 | * drop | |
579 | * existing established connection and move state to connect. | |
580 | */ | |
581 | peer1->last_reset = PEER_DOWN_NSF_CLOSE_SESSION; | |
582 | ||
583 | if (CHECK_FLAG(peer1->flags, PEER_FLAG_GRACEFUL_RESTART) | |
584 | || CHECK_FLAG(peer1->flags, | |
585 | PEER_FLAG_GRACEFUL_RESTART_HELPER)) | |
586 | SET_FLAG(peer1->sflags, PEER_STATUS_NSF_WAIT); | |
587 | ||
588 | bgp_event_update(peer1, TCP_connection_closed); | |
589 | } | |
590 | ||
591 | if (peer_active(peer)) { | |
592 | if (CHECK_FLAG(peer->flags, PEER_FLAG_TIMER_DELAYOPEN)) | |
593 | BGP_EVENT_ADD(peer, TCP_connection_open_w_delay); | |
594 | else | |
595 | BGP_EVENT_ADD(peer, TCP_connection_open); | |
596 | } | |
597 | ||
598 | /* | |
599 | * If we are doing nht for a peer that is v6 LL based | |
600 | * massage the event system to make things happy | |
601 | */ | |
602 | bgp_nht_interface_events(peer); | |
603 | } | |
604 | ||
605 | /* BGP socket bind. */ | |
606 | static char *bgp_get_bound_name(struct peer *peer) | |
607 | { | |
608 | if (!peer) | |
609 | return NULL; | |
610 | ||
611 | if ((peer->bgp->vrf_id == VRF_DEFAULT) && !peer->ifname | |
612 | && !peer->conf_if) | |
613 | return NULL; | |
614 | ||
615 | if (peer->su.sa.sa_family != AF_INET | |
616 | && peer->su.sa.sa_family != AF_INET6) | |
617 | return NULL; // unexpected | |
618 | ||
619 | /* For IPv6 peering, interface (unnumbered or link-local with interface) | |
620 | * takes precedence over VRF. For IPv4 peering, explicit interface or | |
621 | * VRF are the situations to bind. | |
622 | */ | |
623 | if (peer->su.sa.sa_family == AF_INET6 && peer->conf_if) | |
624 | return peer->conf_if; | |
625 | ||
626 | if (peer->ifname) | |
627 | return peer->ifname; | |
628 | ||
629 | if (peer->bgp->inst_type == BGP_INSTANCE_TYPE_VIEW) | |
630 | return NULL; | |
631 | ||
632 | return peer->bgp->name; | |
633 | } | |
634 | ||
635 | static int bgp_update_address(struct interface *ifp, const union sockunion *dst, | |
636 | union sockunion *addr) | |
637 | { | |
638 | struct prefix *p, *sel, d; | |
639 | struct connected *connected; | |
640 | struct listnode *node; | |
641 | int common; | |
642 | ||
643 | if (!sockunion2hostprefix(dst, &d)) | |
644 | return 1; | |
645 | ||
646 | sel = NULL; | |
647 | common = -1; | |
648 | ||
649 | for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, connected)) { | |
650 | p = connected->address; | |
651 | if (p->family != d.family) | |
652 | continue; | |
653 | if (prefix_common_bits(p, &d) > common) { | |
654 | sel = p; | |
655 | common = prefix_common_bits(sel, &d); | |
656 | } | |
657 | } | |
658 | ||
659 | if (!sel) | |
660 | return 1; | |
661 | ||
662 | prefix2sockunion(sel, addr); | |
663 | return 0; | |
664 | } | |
665 | ||
666 | /* Update source selection. */ | |
667 | static int bgp_update_source(struct peer *peer) | |
668 | { | |
669 | struct interface *ifp; | |
670 | union sockunion addr; | |
671 | int ret = 0; | |
672 | ||
673 | sockunion_init(&addr); | |
674 | ||
675 | /* Source is specified with interface name. */ | |
676 | if (peer->update_if) { | |
677 | ifp = if_lookup_by_name(peer->update_if, peer->bgp->vrf_id); | |
678 | if (!ifp) | |
679 | return -1; | |
680 | ||
681 | if (bgp_update_address(ifp, &peer->su, &addr)) | |
682 | return -1; | |
683 | ||
684 | ret = sockunion_bind(peer->fd, &addr, 0, &addr); | |
685 | } | |
686 | ||
687 | /* Source is specified with IP address. */ | |
688 | if (peer->update_source) | |
689 | ret = sockunion_bind(peer->fd, peer->update_source, 0, | |
690 | peer->update_source); | |
691 | ||
692 | return ret; | |
693 | } | |
694 | ||
695 | /* BGP try to connect to the peer. */ | |
696 | int bgp_connect(struct peer *peer) | |
697 | { | |
698 | assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON)); | |
699 | assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON)); | |
700 | ifindex_t ifindex = 0; | |
701 | ||
702 | if (peer->conf_if && BGP_PEER_SU_UNSPEC(peer)) { | |
703 | if (bgp_debug_neighbor_events(peer)) | |
704 | zlog_debug("Peer address not learnt: Returning from connect"); | |
705 | return 0; | |
706 | } | |
707 | frr_with_privs(&bgpd_privs) { | |
708 | /* Make socket for the peer. */ | |
709 | peer->fd = vrf_sockunion_socket(&peer->su, peer->bgp->vrf_id, | |
710 | bgp_get_bound_name(peer)); | |
711 | } | |
712 | if (peer->fd < 0) { | |
713 | peer->last_reset = PEER_DOWN_SOCKET_ERROR; | |
714 | if (bgp_debug_neighbor_events(peer)) | |
715 | zlog_debug("%s: Failure to create socket for connection to %s, error received: %s(%d)", | |
716 | __func__, peer->host, safe_strerror(errno), | |
717 | errno); | |
718 | return -1; | |
719 | } | |
720 | ||
721 | set_nonblocking(peer->fd); | |
722 | ||
723 | /* Set the user configured MSS to TCP socket */ | |
724 | if (CHECK_FLAG(peer->flags, PEER_FLAG_TCP_MSS)) | |
725 | sockopt_tcp_mss_set(peer->fd, peer->tcp_mss); | |
726 | ||
727 | bgp_socket_set_buffer_size(peer->fd); | |
728 | ||
729 | if (bgp_set_socket_ttl(peer, peer->fd) < 0) { | |
730 | peer->last_reset = PEER_DOWN_SOCKET_ERROR; | |
731 | if (bgp_debug_neighbor_events(peer)) | |
732 | zlog_debug("%s: Failure to set socket ttl for connection to %s, error received: %s(%d)", | |
733 | __func__, peer->host, safe_strerror(errno), | |
734 | errno); | |
735 | return -1; | |
736 | } | |
737 | ||
738 | sockopt_reuseaddr(peer->fd); | |
739 | sockopt_reuseport(peer->fd); | |
740 | ||
741 | #ifdef IPTOS_PREC_INTERNETCONTROL | |
742 | frr_with_privs(&bgpd_privs) { | |
743 | if (sockunion_family(&peer->su) == AF_INET) | |
744 | setsockopt_ipv4_tos(peer->fd, | |
745 | IPTOS_PREC_INTERNETCONTROL); | |
746 | else if (sockunion_family(&peer->su) == AF_INET6) | |
747 | setsockopt_ipv6_tclass(peer->fd, | |
748 | IPTOS_PREC_INTERNETCONTROL); | |
749 | } | |
750 | #endif | |
751 | ||
752 | if (peer->password) { | |
753 | uint16_t prefixlen = peer->su.sa.sa_family == AF_INET | |
754 | ? IPV4_MAX_BITLEN | |
755 | : IPV6_MAX_BITLEN; | |
756 | ||
757 | bgp_md5_set_connect(peer->fd, &peer->su, prefixlen, | |
758 | peer->password); | |
759 | } | |
760 | ||
761 | /* Update source bind. */ | |
762 | if (bgp_update_source(peer) < 0) { | |
763 | peer->last_reset = PEER_DOWN_SOCKET_ERROR; | |
764 | return connect_error; | |
765 | } | |
766 | ||
767 | if (peer->conf_if || peer->ifname) | |
768 | ifindex = ifname2ifindex(peer->conf_if ? peer->conf_if | |
769 | : peer->ifname, | |
770 | peer->bgp->vrf_id); | |
771 | ||
772 | if (bgp_debug_neighbor_events(peer)) | |
773 | zlog_debug("%s [Event] Connect start to %s fd %d", peer->host, | |
774 | peer->host, peer->fd); | |
775 | ||
776 | /* Connect to the remote peer. */ | |
777 | return sockunion_connect(peer->fd, &peer->su, htons(peer->port), | |
778 | ifindex); | |
779 | } | |
780 | ||
781 | /* After TCP connection is established. Get local address and port. */ | |
782 | int bgp_getsockname(struct peer *peer) | |
783 | { | |
784 | if (peer->su_local) { | |
785 | sockunion_free(peer->su_local); | |
786 | peer->su_local = NULL; | |
787 | } | |
788 | ||
789 | if (peer->su_remote) { | |
790 | sockunion_free(peer->su_remote); | |
791 | peer->su_remote = NULL; | |
792 | } | |
793 | ||
794 | peer->su_local = sockunion_getsockname(peer->fd); | |
795 | if (!peer->su_local) | |
796 | return -1; | |
797 | peer->su_remote = sockunion_getpeername(peer->fd); | |
798 | if (!peer->su_remote) | |
799 | return -1; | |
800 | ||
801 | if (!bgp_zebra_nexthop_set(peer->su_local, peer->su_remote, | |
802 | &peer->nexthop, peer)) { | |
803 | flog_err(EC_BGP_NH_UPD, | |
804 | "%s: nexthop_set failed, resetting connection - intf %p", | |
805 | peer->host, peer->nexthop.ifp); | |
806 | return -1; | |
807 | } | |
808 | return 0; | |
809 | } | |
810 | ||
811 | ||
812 | static int bgp_listener(int sock, struct sockaddr *sa, socklen_t salen, | |
813 | struct bgp *bgp) | |
814 | { | |
815 | struct bgp_listener *listener; | |
816 | int ret, en; | |
817 | ||
818 | sockopt_reuseaddr(sock); | |
819 | sockopt_reuseport(sock); | |
820 | ||
821 | frr_with_privs(&bgpd_privs) { | |
822 | ||
823 | #ifdef IPTOS_PREC_INTERNETCONTROL | |
824 | if (sa->sa_family == AF_INET) | |
825 | setsockopt_ipv4_tos(sock, IPTOS_PREC_INTERNETCONTROL); | |
826 | else if (sa->sa_family == AF_INET6) | |
827 | setsockopt_ipv6_tclass(sock, | |
828 | IPTOS_PREC_INTERNETCONTROL); | |
829 | #endif | |
830 | ||
831 | sockopt_v6only(sa->sa_family, sock); | |
832 | ||
833 | ret = bind(sock, sa, salen); | |
834 | en = errno; | |
835 | } | |
836 | ||
837 | if (ret < 0) { | |
838 | flog_err_sys(EC_LIB_SOCKET, "bind: %s", safe_strerror(en)); | |
839 | return ret; | |
840 | } | |
841 | ||
842 | ret = listen(sock, SOMAXCONN); | |
843 | if (ret < 0) { | |
844 | flog_err_sys(EC_LIB_SOCKET, "listen: %s", safe_strerror(errno)); | |
845 | return ret; | |
846 | } | |
847 | ||
848 | listener = XCALLOC(MTYPE_BGP_LISTENER, sizeof(*listener)); | |
849 | listener->fd = sock; | |
850 | listener->name = XSTRDUP(MTYPE_BGP_LISTENER, bgp->name); | |
851 | ||
852 | /* this socket is in a vrf record bgp back pointer */ | |
853 | if (bgp->vrf_id != VRF_DEFAULT) | |
854 | listener->bgp = bgp; | |
855 | ||
856 | memcpy(&listener->su, sa, salen); | |
857 | thread_add_read(bm->master, bgp_accept, listener, sock, | |
858 | &listener->thread); | |
859 | listnode_add(bm->listen_sockets, listener); | |
860 | ||
861 | return 0; | |
862 | } | |
863 | ||
864 | /* IPv6 supported version of BGP server socket setup. */ | |
865 | int bgp_socket(struct bgp *bgp, unsigned short port, const char *address) | |
866 | { | |
867 | struct addrinfo *ainfo; | |
868 | struct addrinfo *ainfo_save; | |
869 | static const struct addrinfo req = { | |
870 | .ai_family = AF_UNSPEC, | |
871 | .ai_flags = AI_PASSIVE, | |
872 | .ai_socktype = SOCK_STREAM, | |
873 | }; | |
874 | int ret, count; | |
875 | char port_str[BUFSIZ]; | |
876 | ||
877 | snprintf(port_str, sizeof(port_str), "%d", port); | |
878 | port_str[sizeof(port_str) - 1] = '\0'; | |
879 | ||
880 | frr_with_privs(&bgpd_privs) { | |
881 | ret = vrf_getaddrinfo(address, port_str, &req, &ainfo_save, | |
882 | bgp->vrf_id); | |
883 | } | |
884 | if (ret != 0) { | |
885 | flog_err_sys(EC_LIB_SOCKET, "getaddrinfo: %s", | |
886 | gai_strerror(ret)); | |
887 | return -1; | |
888 | } | |
889 | if (bgp_option_check(BGP_OPT_NO_ZEBRA) && | |
890 | bgp->vrf_id != VRF_DEFAULT) { | |
891 | freeaddrinfo(ainfo_save); | |
892 | return -1; | |
893 | } | |
894 | count = 0; | |
895 | for (ainfo = ainfo_save; ainfo; ainfo = ainfo->ai_next) { | |
896 | int sock; | |
897 | ||
898 | if (ainfo->ai_family != AF_INET && ainfo->ai_family != AF_INET6) | |
899 | continue; | |
900 | ||
901 | frr_with_privs(&bgpd_privs) { | |
902 | sock = vrf_socket(ainfo->ai_family, | |
903 | ainfo->ai_socktype, | |
904 | ainfo->ai_protocol, | |
905 | bgp->vrf_id, | |
906 | (bgp->inst_type | |
907 | == BGP_INSTANCE_TYPE_VRF | |
908 | ? bgp->name : NULL)); | |
909 | } | |
910 | if (sock < 0) { | |
911 | flog_err_sys(EC_LIB_SOCKET, "socket: %s", | |
912 | safe_strerror(errno)); | |
913 | continue; | |
914 | } | |
915 | ||
916 | /* if we intend to implement ttl-security, this socket needs | |
917 | * ttl=255 */ | |
918 | sockopt_ttl(ainfo->ai_family, sock, MAXTTL); | |
919 | ||
920 | ret = bgp_listener(sock, ainfo->ai_addr, ainfo->ai_addrlen, | |
921 | bgp); | |
922 | if (ret == 0) | |
923 | ++count; | |
924 | else | |
925 | close(sock); | |
926 | } | |
927 | freeaddrinfo(ainfo_save); | |
928 | if (count == 0 && bgp->inst_type != BGP_INSTANCE_TYPE_VRF) { | |
929 | flog_err( | |
930 | EC_LIB_SOCKET, | |
931 | "%s: no usable addresses please check other programs usage of specified port %d", | |
932 | __func__, port); | |
933 | flog_err_sys(EC_LIB_SOCKET, "%s: Program cannot continue", | |
934 | __func__); | |
935 | exit(-1); | |
936 | } | |
937 | ||
938 | return 0; | |
939 | } | |
940 | ||
941 | /* this function closes vrf socket | |
942 | * this should be called only for vrf socket with netns backend | |
943 | */ | |
944 | void bgp_close_vrf_socket(struct bgp *bgp) | |
945 | { | |
946 | struct listnode *node, *next; | |
947 | struct bgp_listener *listener; | |
948 | ||
949 | if (!bgp) | |
950 | return; | |
951 | ||
952 | if (bm->listen_sockets == NULL) | |
953 | return; | |
954 | ||
955 | for (ALL_LIST_ELEMENTS(bm->listen_sockets, node, next, listener)) { | |
956 | if (listener->bgp == bgp) { | |
957 | THREAD_OFF(listener->thread); | |
958 | close(listener->fd); | |
959 | listnode_delete(bm->listen_sockets, listener); | |
960 | XFREE(MTYPE_BGP_LISTENER, listener->name); | |
961 | XFREE(MTYPE_BGP_LISTENER, listener); | |
962 | } | |
963 | } | |
964 | } | |
965 | ||
966 | /* this function closes main socket | |
967 | */ | |
968 | void bgp_close(void) | |
969 | { | |
970 | struct listnode *node, *next; | |
971 | struct bgp_listener *listener; | |
972 | ||
973 | if (bm->listen_sockets == NULL) | |
974 | return; | |
975 | ||
976 | for (ALL_LIST_ELEMENTS(bm->listen_sockets, node, next, listener)) { | |
977 | if (listener->bgp) | |
978 | continue; | |
979 | THREAD_OFF(listener->thread); | |
980 | close(listener->fd); | |
981 | listnode_delete(bm->listen_sockets, listener); | |
982 | XFREE(MTYPE_BGP_LISTENER, listener->name); | |
983 | XFREE(MTYPE_BGP_LISTENER, listener); | |
984 | } | |
985 | } |