xref: /openbsd-src/usr.sbin/ospf6d/database.c (revision 77fbfa19a8cee18aa3acb3e4a9ddee17335f1f53)
1 /*	$OpenBSD: database.c,v 1.18 2019/12/23 07:33:49 denis Exp $ */
2 
3 /*
4  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
5  * Copyright (c) 2004, 2005, 2007 Esben Norby <norby@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/socket.h>
22 #include <netinet/in.h>
23 #include <netinet/ip6.h>
24 #include <arpa/inet.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #include "ospf6d.h"
30 #include "ospf6.h"
31 #include "log.h"
32 #include "ospfe.h"
33 
34 extern struct ospfd_conf	*oeconf;
35 
36 void	db_sum_list_next(struct nbr *);
37 
38 /* database description packet handling */
39 int
40 send_db_description(struct nbr *nbr)
41 {
42 	struct in6_addr		 dst;
43 	struct db_dscrp_hdr	 dd_hdr;
44 	struct lsa_entry	*le, *nle;
45 	struct ibuf		*buf;
46 	int			 ret = 0;
47 	u_int8_t		 bits = 0;
48 
49 	if ((buf = ibuf_open(nbr->iface->mtu - sizeof(struct ip6_hdr))) == NULL)
50 		fatal("send_db_description");
51 
52 	/* OSPF header */
53 	if (gen_ospf_hdr(buf, nbr->iface, PACKET_TYPE_DD))
54 		goto fail;
55 
56 	/* reserve space for database description header */
57 	if (ibuf_reserve(buf, sizeof(dd_hdr)) == NULL)
58 		goto fail;
59 
60 	switch (nbr->state) {
61 	case NBR_STA_DOWN:
62 	case NBR_STA_ATTEMPT:
63 	case NBR_STA_INIT:
64 	case NBR_STA_2_WAY:
65 	case NBR_STA_SNAP:
66 		log_debug("send_db_description: cannot send packet in state %s,"
67 		    " neighbor ID %s", nbr_state_name(nbr->state),
68 		    inet_ntoa(nbr->id));
69 		ret = -1;
70 		goto done;
71 	case NBR_STA_XSTRT:
72 		bits |= OSPF_DBD_MS | OSPF_DBD_M | OSPF_DBD_I;
73 		nbr->dd_more = 1;
74 		break;
75 	case NBR_STA_XCHNG:
76 		if (nbr->dd_master)
77 			bits |= OSPF_DBD_MS;
78 		else
79 			bits &= ~OSPF_DBD_MS;
80 
81 		if (TAILQ_EMPTY(&nbr->db_sum_list)) {
82 			bits &= ~OSPF_DBD_M;
83 			nbr->dd_more = 0;
84 		} else {
85 			bits |= OSPF_DBD_M;
86 			nbr->dd_more = 1;
87 		}
88 
89 		bits &= ~OSPF_DBD_I;
90 
91 		/* build LSA list */
92 		for (le = TAILQ_FIRST(&nbr->db_sum_list); le != NULL &&
93 		    buf->wpos + sizeof(struct lsa_hdr) < buf->max; le = nle) {
94 			nbr->dd_end = nle = TAILQ_NEXT(le, entry);
95 			if (ibuf_add(buf, le->le_lsa, sizeof(struct lsa_hdr)))
96 				goto fail;
97 		}
98 		break;
99 	case NBR_STA_LOAD:
100 	case NBR_STA_FULL:
101 		if (nbr->dd_master)
102 			bits |= OSPF_DBD_MS;
103 		else
104 			bits &= ~OSPF_DBD_MS;
105 		bits &= ~OSPF_DBD_M;
106 		bits &= ~OSPF_DBD_I;
107 
108 		nbr->dd_more = 0;
109 		break;
110 	default:
111 		fatalx("send_db_description: unknown neighbor state");
112 	}
113 
114 	bzero(&dd_hdr, sizeof(dd_hdr));
115 
116 	switch (nbr->iface->type) {
117 	case IF_TYPE_POINTOPOINT:
118 		inet_pton(AF_INET6, AllSPFRouters, &dst);
119 		dd_hdr.iface_mtu = htons(nbr->iface->mtu);
120 		break;
121 	case IF_TYPE_BROADCAST:
122 		dst = nbr->addr;
123 		dd_hdr.iface_mtu = htons(nbr->iface->mtu);
124 		break;
125 	case IF_TYPE_NBMA:
126 	case IF_TYPE_POINTOMULTIPOINT:
127 		/* XXX not supported */
128 		break;
129 	case IF_TYPE_VIRTUALLINK:
130 		dst = nbr->iface->dst;
131 		dd_hdr.iface_mtu = 0;
132 		break;
133 	default:
134 		fatalx("send_db_description: unknown interface type");
135 	}
136 
137 	dd_hdr.opts = htonl(area_ospf_options(nbr->iface->area));
138 	dd_hdr.bits = bits;
139 	dd_hdr.dd_seq_num = htonl(nbr->dd_seq_num);
140 
141 	memcpy(ibuf_seek(buf, sizeof(struct ospf_hdr), sizeof(dd_hdr)),
142 	    &dd_hdr, sizeof(dd_hdr));
143 
144 	/* calculate checksum */
145 	if (upd_ospf_hdr(buf, nbr->iface))
146 		goto fail;
147 
148 	/* transmit packet */
149 	ret = send_packet(nbr->iface, buf, &dst);
150 done:
151 	ibuf_free(buf);
152 	return (ret);
153 fail:
154 	log_warn("send_db_description");
155 	ibuf_free(buf);
156 	return (-1);
157 }
158 
159 void
160 recv_db_description(struct nbr *nbr, char *buf, u_int16_t len)
161 {
162 	struct db_dscrp_hdr	 dd_hdr;
163 	int			 dupe = 0;
164 
165 	if (len < sizeof(dd_hdr)) {
166 		log_warnx("recv_db_description: "
167 		    "bad packet size, neighbor ID %s", inet_ntoa(nbr->id));
168 		return;
169 	}
170 	memcpy(&dd_hdr, buf, sizeof(dd_hdr));
171 	buf += sizeof(dd_hdr);
172 	len -= sizeof(dd_hdr);
173 
174 	/* db description packet sanity checks */
175 	if (ntohs(dd_hdr.iface_mtu) > nbr->iface->mtu) {
176 		log_warnx("recv_db_description: invalid MTU %d sent by "
177 		    "neighbor ID %s, expected %d", ntohs(dd_hdr.iface_mtu),
178 		    inet_ntoa(nbr->id), nbr->iface->mtu);
179 		return;
180 	}
181 
182 	if (nbr->last_rx_options == dd_hdr.opts &&
183 	    nbr->last_rx_bits == dd_hdr.bits &&
184 	    ntohl(dd_hdr.dd_seq_num) == nbr->dd_seq_num - nbr->dd_master ?
185 	    1 : 0) {
186 		log_debug("recv_db_description: dupe from ID %s",
187 		    inet_ntoa(nbr->id));
188 		dupe = 1;
189 	}
190 
191 	switch (nbr->state) {
192 	case NBR_STA_DOWN:
193 	case NBR_STA_ATTEMPT:
194 	case NBR_STA_2_WAY:
195 	case NBR_STA_SNAP:
196 		log_debug("recv_db_description: packet ignored in state %s, "
197 		    "neighbor ID %s", nbr_state_name(nbr->state),
198 		    inet_ntoa(nbr->id));
199 		return;
200 	case NBR_STA_INIT:
201 		/* evaluate dr and bdr after issuing a 2-Way event */
202 		nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
203 		if_fsm(nbr->iface, IF_EVT_NBR_CHNG);
204 		if (nbr->state != NBR_STA_XSTRT)
205 			return;
206 		/* FALLTHROUGH */
207 	case NBR_STA_XSTRT:
208 		if (dupe)
209 			return;
210 		/*
211 		 * check bits: either I,M,MS or only M
212 		 */
213 		if (dd_hdr.bits == (OSPF_DBD_I | OSPF_DBD_M | OSPF_DBD_MS)) {
214 			/* if nbr Router ID is larger than own -> slave */
215 			if ((ntohl(nbr->id.s_addr)) >
216 			    ntohl(ospfe_router_id())) {
217 				/* slave */
218 				nbr->dd_master = 0;
219 				nbr->dd_seq_num = ntohl(dd_hdr.dd_seq_num);
220 
221 				/* event negotiation done */
222 				nbr_fsm(nbr, NBR_EVT_NEG_DONE);
223 			}
224 		} else if (!(dd_hdr.bits & (OSPF_DBD_I | OSPF_DBD_MS))) {
225 			/* M only case: we are master */
226 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num) {
227 				log_warnx("recv_db_description: invalid "
228 				    "seq num, mine %x his %x",
229 				    nbr->dd_seq_num, ntohl(dd_hdr.dd_seq_num));
230 				return;
231 			}
232 			nbr->dd_seq_num++;
233 
234 			/* event negotiation done */
235 			nbr_fsm(nbr, NBR_EVT_NEG_DONE);
236 
237 			/* this packet may already have data so pass it on */
238 			if (len > 0) {
239 				nbr->dd_pending++;
240 				ospfe_imsg_compose_rde(IMSG_DD, nbr->peerid,
241 				    0, buf, len);
242 			}
243 		} else {
244 			/* ignore packet */
245 			log_debug("recv_db_description: packet ignored in "
246 			    "state %s (bad flags), neighbor ID %s",
247 			    nbr_state_name(nbr->state), inet_ntoa(nbr->id));
248 		}
249 		break;
250 	case NBR_STA_XCHNG:
251 	case NBR_STA_LOAD:
252 	case NBR_STA_FULL:
253 		if (dd_hdr.bits & OSPF_DBD_I ||
254 		    !(dd_hdr.bits & OSPF_DBD_MS) == !nbr->dd_master) {
255 			log_warnx("recv_db_description: seq num mismatch, "
256 			    "bad flags");
257 			nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
258 			return;
259 		}
260 
261 		if (nbr->last_rx_options != dd_hdr.opts) {
262 			log_warnx("recv_db_description: seq num mismatch, "
263 			    "bad options");
264 			nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
265 			return;
266 		}
267 
268 		if (dupe) {
269 			if (!nbr->dd_master)
270 				/* retransmit */
271 				start_db_tx_timer(nbr);
272 			return;
273 		}
274 
275 		if (nbr->state != NBR_STA_XCHNG) {
276 			log_warnx("recv_db_description: invalid "
277 			    "seq num, mine %x his %x",
278 			    nbr->dd_seq_num, ntohl(dd_hdr.dd_seq_num));
279 			nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
280 			return;
281 		}
282 
283 		/* sanity check dd seq number */
284 		if (nbr->dd_master) {
285 			/* master */
286 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num) {
287 				log_warnx("recv_db_description: invalid "
288 				    "seq num, mine %x his %x",
289 				    nbr->dd_seq_num, ntohl(dd_hdr.dd_seq_num));
290 				nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
291 				return;
292 			}
293 			nbr->dd_seq_num++;
294 		} else {
295 			/* slave */
296 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num + 1) {
297 				log_warnx("recv_db_description: invalid "
298 				    "seq num, mine %x his %x",
299 				    nbr->dd_seq_num, ntohl(dd_hdr.dd_seq_num));
300 				nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
301 				return;
302 			}
303 			nbr->dd_seq_num = ntohl(dd_hdr.dd_seq_num);
304 		}
305 
306 		/* forward to RDE and let it decide which LSAs to request */
307 		if (len > 0) {
308 			nbr->dd_pending++;
309 			ospfe_imsg_compose_rde(IMSG_DD, nbr->peerid, 0,
310 			    buf, len);
311 		}
312 
313 		/* next packet */
314 		db_sum_list_next(nbr);
315 		start_db_tx_timer(nbr);
316 
317 		if (!(dd_hdr.bits & OSPF_DBD_M) &&
318 		    TAILQ_EMPTY(&nbr->db_sum_list))
319 			if (!nbr->dd_master || !nbr->dd_more)
320 				nbr_fsm(nbr, NBR_EVT_XCHNG_DONE);
321 		break;
322 	default:
323 		fatalx("recv_db_description: unknown neighbor state");
324 	}
325 
326 	nbr->last_rx_options = dd_hdr.opts;
327 	nbr->last_rx_bits = dd_hdr.bits;
328 }
329 
330 void
331 db_sum_list_add(struct nbr *nbr, struct lsa_hdr *lsa)
332 {
333 	struct lsa_entry	*le;
334 
335 	if ((le = calloc(1, sizeof(*le))) == NULL)
336 		fatal("db_sum_list_add");
337 
338 	TAILQ_INSERT_TAIL(&nbr->db_sum_list, le, entry);
339 	le->le_lsa = lsa;
340 }
341 
342 void
343 db_sum_list_next(struct nbr *nbr)
344 {
345 	struct lsa_entry	*le;
346 
347 	while ((le = TAILQ_FIRST(&nbr->db_sum_list)) != nbr->dd_end) {
348 		TAILQ_REMOVE(&nbr->db_sum_list, le, entry);
349 		free(le->le_lsa);
350 		free(le);
351 	}
352 }
353 
354 void
355 db_sum_list_clr(struct nbr *nbr)
356 {
357 	nbr->dd_end = NULL;
358 	db_sum_list_next(nbr);
359 }
360 
361 /* timers */
362 /* ARGSUSED */
363 void
364 db_tx_timer(int fd, short event, void *arg)
365 {
366 	struct nbr *nbr = arg;
367 	struct timeval tv;
368 
369 	switch (nbr->state) {
370 	case NBR_STA_DOWN:
371 	case NBR_STA_ATTEMPT:
372 	case NBR_STA_INIT:
373 	case NBR_STA_2_WAY:
374 	case NBR_STA_SNAP:
375 		return ;
376 	case NBR_STA_XSTRT:
377 	case NBR_STA_XCHNG:
378 	case NBR_STA_LOAD:
379 	case NBR_STA_FULL:
380 		send_db_description(nbr);
381 		break;
382 	default:
383 		log_debug("db_tx_timer: unknown neighbor state, "
384 		    "neighbor ID %s", inet_ntoa(nbr->id));
385 		break;
386 	}
387 
388 	/* reschedule db_tx_timer but only in master mode */
389 	if (nbr->dd_master) {
390 		timerclear(&tv);
391 		tv.tv_sec = nbr->iface->rxmt_interval;
392 		if (evtimer_add(&nbr->db_tx_timer, &tv) == -1)
393 			fatal("db_tx_timer");
394 	}
395 }
396 
397 void
398 start_db_tx_timer(struct nbr *nbr)
399 {
400 	struct timeval	tv;
401 
402 	if (nbr == nbr->iface->self)
403 		return;
404 
405 	timerclear(&tv);
406 	if (evtimer_add(&nbr->db_tx_timer, &tv) == -1)
407 		fatal("start_db_tx_timer");
408 }
409 
410 void
411 stop_db_tx_timer(struct nbr *nbr)
412 {
413 	if (nbr == nbr->iface->self)
414 		return;
415 
416 	if (evtimer_del(&nbr->db_tx_timer) == -1)
417 		fatal("stop_db_tx_timer");
418 }
419