xref: /openbsd/usr.sbin/ospf6d/database.c (revision 09467b48)
1 /*	$OpenBSD: database.c,v 1.20 2020/07/15 14:47:41 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 void	db_sum_list_next(struct nbr *);
35 
36 /* database description packet handling */
37 int
38 send_db_description(struct nbr *nbr)
39 {
40 	struct in6_addr		 dst;
41 	struct db_dscrp_hdr	 dd_hdr;
42 	struct lsa_entry	*le, *nle;
43 	struct ibuf		*buf;
44 	u_int8_t		 bits = 0;
45 
46 	if ((buf = ibuf_open(nbr->iface->mtu - sizeof(struct ip6_hdr))) == NULL)
47 		fatal("send_db_description");
48 
49 	/* OSPF header */
50 	if (gen_ospf_hdr(buf, nbr->iface, PACKET_TYPE_DD))
51 		goto fail;
52 
53 	/* reserve space for database description header */
54 	if (ibuf_reserve(buf, sizeof(dd_hdr)) == NULL)
55 		goto fail;
56 
57 	switch (nbr->state) {
58 	case NBR_STA_DOWN:
59 	case NBR_STA_ATTEMPT:
60 	case NBR_STA_INIT:
61 	case NBR_STA_2_WAY:
62 	case NBR_STA_SNAP:
63 		log_debug("send_db_description: neighbor ID %s: "
64 		    "cannot send packet in state %s", inet_ntoa(nbr->id),
65 		    nbr_state_name(nbr->state));
66 		goto fail;
67 	case NBR_STA_XSTRT:
68 		bits |= OSPF_DBD_MS | OSPF_DBD_M | OSPF_DBD_I;
69 		nbr->dd_more = 1;
70 		break;
71 	case NBR_STA_XCHNG:
72 		if (nbr->dd_master)
73 			bits |= OSPF_DBD_MS;
74 		else
75 			bits &= ~OSPF_DBD_MS;
76 
77 		if (TAILQ_EMPTY(&nbr->db_sum_list)) {
78 			bits &= ~OSPF_DBD_M;
79 			nbr->dd_more = 0;
80 		} else {
81 			bits |= OSPF_DBD_M;
82 			nbr->dd_more = 1;
83 		}
84 
85 		bits &= ~OSPF_DBD_I;
86 
87 		/* build LSA list */
88 		for (le = TAILQ_FIRST(&nbr->db_sum_list); le != NULL &&
89 		    ibuf_left(buf) >=  sizeof(struct lsa_hdr); le = nle) {
90 			nbr->dd_end = nle = TAILQ_NEXT(le, entry);
91 			if (ibuf_add(buf, le->le_lsa, sizeof(struct lsa_hdr)))
92 				goto fail;
93 		}
94 		break;
95 	case NBR_STA_LOAD:
96 	case NBR_STA_FULL:
97 		if (nbr->dd_master)
98 			bits |= OSPF_DBD_MS;
99 		else
100 			bits &= ~OSPF_DBD_MS;
101 		bits &= ~OSPF_DBD_M;
102 		bits &= ~OSPF_DBD_I;
103 
104 		nbr->dd_more = 0;
105 		break;
106 	default:
107 		fatalx("send_db_description: unknown neighbor state");
108 	}
109 
110 	bzero(&dd_hdr, sizeof(dd_hdr));
111 
112 	switch (nbr->iface->type) {
113 	case IF_TYPE_POINTOPOINT:
114 		inet_pton(AF_INET6, AllSPFRouters, &dst);
115 		dd_hdr.iface_mtu = htons(nbr->iface->mtu);
116 		break;
117 	case IF_TYPE_BROADCAST:
118 		dst = nbr->addr;
119 		dd_hdr.iface_mtu = htons(nbr->iface->mtu);
120 		break;
121 	case IF_TYPE_NBMA:
122 	case IF_TYPE_POINTOMULTIPOINT:
123 		/* XXX not supported */
124 		break;
125 	case IF_TYPE_VIRTUALLINK:
126 		dst = nbr->iface->dst;
127 		dd_hdr.iface_mtu = 0;
128 		break;
129 	default:
130 		fatalx("send_db_description: unknown interface type");
131 	}
132 
133 	dd_hdr.opts = htonl(area_ospf_options(nbr->iface->area));
134 	dd_hdr.bits = bits;
135 	dd_hdr.dd_seq_num = htonl(nbr->dd_seq_num);
136 
137 	memcpy(ibuf_seek(buf, sizeof(struct ospf_hdr), sizeof(dd_hdr)),
138 	    &dd_hdr, sizeof(dd_hdr));
139 
140 	/* calculate checksum */
141 	if (upd_ospf_hdr(buf, nbr->iface))
142 		goto fail;
143 
144 	/* transmit packet */
145 	if (send_packet(nbr->iface, buf, &dst) == -1)
146 		goto fail;
147 
148 	ibuf_free(buf);
149 	return (0);
150 fail:
151 	log_warn("send_db_description");
152 	ibuf_free(buf);
153 	return (-1);
154 }
155 
156 void
157 recv_db_description(struct nbr *nbr, char *buf, u_int16_t len)
158 {
159 	struct db_dscrp_hdr	 dd_hdr;
160 	int			 dupe = 0;
161 
162 	if (len < sizeof(dd_hdr)) {
163 		log_warnx("recv_db_description: neighbor ID %s: "
164 		    "bad packet size", inet_ntoa(nbr->id));
165 		return;
166 	}
167 	memcpy(&dd_hdr, buf, sizeof(dd_hdr));
168 	buf += sizeof(dd_hdr);
169 	len -= sizeof(dd_hdr);
170 
171 	/* db description packet sanity checks */
172 	if (ntohs(dd_hdr.iface_mtu) > nbr->iface->mtu) {
173 		log_warnx("recv_db_description: neighbor ID %s: "
174 		    "invalid MTU %d expected %d", inet_ntoa(nbr->id),
175 		    ntohs(dd_hdr.iface_mtu), nbr->iface->mtu);
176 		return;
177 	}
178 
179 	if (nbr->last_rx_options == dd_hdr.opts &&
180 	    nbr->last_rx_bits == dd_hdr.bits &&
181 	    ntohl(dd_hdr.dd_seq_num) == nbr->dd_seq_num - nbr->dd_master ?
182 	    1 : 0) {
183 		log_debug("recv_db_description: dupe from neighbor ID %s",
184 		    inet_ntoa(nbr->id));
185 		dupe = 1;
186 	}
187 
188 	switch (nbr->state) {
189 	case NBR_STA_DOWN:
190 	case NBR_STA_ATTEMPT:
191 	case NBR_STA_2_WAY:
192 	case NBR_STA_SNAP:
193 		log_debug("recv_db_description: neighbor ID %s: "
194 		    "packet ignored in state %s", inet_ntoa(nbr->id),
195 		    nbr_state_name(nbr->state));
196 		return;
197 	case NBR_STA_INIT:
198 		/* evaluate dr and bdr after issuing a 2-Way event */
199 		nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
200 		if_fsm(nbr->iface, IF_EVT_NBR_CHNG);
201 		if (nbr->state != NBR_STA_XSTRT)
202 			return;
203 		/* FALLTHROUGH */
204 	case NBR_STA_XSTRT:
205 		if (dupe)
206 			return;
207 		/*
208 		 * check bits: either I,M,MS or only M
209 		 */
210 		if (dd_hdr.bits == (OSPF_DBD_I | OSPF_DBD_M | OSPF_DBD_MS)) {
211 			/* if nbr Router ID is larger than own -> slave */
212 			if ((ntohl(nbr->id.s_addr)) >
213 			    ntohl(ospfe_router_id())) {
214 				/* slave */
215 				nbr->dd_master = 0;
216 				nbr->dd_seq_num = ntohl(dd_hdr.dd_seq_num);
217 
218 				/* event negotiation done */
219 				nbr_fsm(nbr, NBR_EVT_NEG_DONE);
220 			}
221 		} else if (!(dd_hdr.bits & (OSPF_DBD_I | OSPF_DBD_MS))) {
222 			/* M only case: we are master */
223 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num) {
224 				log_warnx("recv_db_description: "
225 				    "neighbor ID %s: "
226 				    "invalid seq num, mine %x his %x",
227 				    inet_ntoa(nbr->id), nbr->dd_seq_num,
228 				    ntohl(dd_hdr.dd_seq_num));
229 				return;
230 			}
231 			nbr->dd_seq_num++;
232 
233 			/* event negotiation done */
234 			nbr_fsm(nbr, NBR_EVT_NEG_DONE);
235 
236 			/* this packet may already have data so pass it on */
237 			if (len > 0) {
238 				nbr->dd_pending++;
239 				ospfe_imsg_compose_rde(IMSG_DD, nbr->peerid,
240 				    0, buf, len);
241 			}
242 		} else {
243 			/* ignore packet */
244 			log_debug("recv_db_description: neighbor ID %s: "
245 			    "packet ignored in state %s (bad flags)",
246 			    inet_ntoa(nbr->id), nbr_state_name(nbr->state));
247 		}
248 		break;
249 	case NBR_STA_XCHNG:
250 	case NBR_STA_LOAD:
251 	case NBR_STA_FULL:
252 		if (dd_hdr.bits & OSPF_DBD_I ||
253 		    !(dd_hdr.bits & OSPF_DBD_MS) == !nbr->dd_master) {
254 			log_warnx("recv_db_description: neighbor ID %s: "
255 			    "seq num mismatch, bad flags", inet_ntoa(nbr->id));
256 			nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
257 			return;
258 		}
259 
260 		if (nbr->last_rx_options != dd_hdr.opts) {
261 			log_warnx("recv_db_description: neighbor ID %s: "
262 			    "seq num mismatch, bad options",
263 			    inet_ntoa(nbr->id));
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: neighbor ID %s: "
277 			    "invalid seq num, mine %x his %x",
278 			    inet_ntoa(nbr->id), nbr->dd_seq_num,
279 			    ntohl(dd_hdr.dd_seq_num));
280 			nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
281 			return;
282 		}
283 
284 		/* sanity check dd seq number */
285 		if (nbr->dd_master) {
286 			/* master */
287 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num) {
288 				log_warnx("recv_db_description: "
289 				    "neighbor ID %s: "
290 				    "invalid seq num, mine %x his %x, master",
291 				    inet_ntoa(nbr->id), nbr->dd_seq_num,
292 				    ntohl(dd_hdr.dd_seq_num));
293 				nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
294 				return;
295 			}
296 			nbr->dd_seq_num++;
297 		} else {
298 			/* slave */
299 			if (ntohl(dd_hdr.dd_seq_num) != nbr->dd_seq_num + 1) {
300 				log_warnx("recv_db_description: "
301 				    "neighbor ID %s: "
302 				    "invalid seq num, mine %x his %x, slave",
303 				    inet_ntoa(nbr->id), nbr->dd_seq_num,
304 				    ntohl(dd_hdr.dd_seq_num));
305 				nbr_fsm(nbr, NBR_EVT_SEQ_NUM_MIS);
306 				return;
307 			}
308 			nbr->dd_seq_num = ntohl(dd_hdr.dd_seq_num);
309 		}
310 
311 		/* forward to RDE and let it decide which LSAs to request */
312 		if (len > 0) {
313 			nbr->dd_pending++;
314 			ospfe_imsg_compose_rde(IMSG_DD, nbr->peerid, 0,
315 			    buf, len);
316 		}
317 
318 		/* next packet */
319 		db_sum_list_next(nbr);
320 		start_db_tx_timer(nbr);
321 
322 		if (!(dd_hdr.bits & OSPF_DBD_M) &&
323 		    TAILQ_EMPTY(&nbr->db_sum_list))
324 			if (!nbr->dd_master || !nbr->dd_more)
325 				nbr_fsm(nbr, NBR_EVT_XCHNG_DONE);
326 		break;
327 	default:
328 		fatalx("recv_db_description: unknown neighbor state");
329 	}
330 
331 	nbr->last_rx_options = dd_hdr.opts;
332 	nbr->last_rx_bits = dd_hdr.bits;
333 }
334 
335 void
336 db_sum_list_add(struct nbr *nbr, struct lsa_hdr *lsa)
337 {
338 	struct lsa_entry	*le;
339 
340 	if ((le = calloc(1, sizeof(*le))) == NULL)
341 		fatal("db_sum_list_add");
342 
343 	TAILQ_INSERT_TAIL(&nbr->db_sum_list, le, entry);
344 	le->le_lsa = lsa;
345 }
346 
347 void
348 db_sum_list_next(struct nbr *nbr)
349 {
350 	struct lsa_entry	*le;
351 
352 	while ((le = TAILQ_FIRST(&nbr->db_sum_list)) != nbr->dd_end) {
353 		TAILQ_REMOVE(&nbr->db_sum_list, le, entry);
354 		free(le->le_lsa);
355 		free(le);
356 	}
357 }
358 
359 void
360 db_sum_list_clr(struct nbr *nbr)
361 {
362 	nbr->dd_end = NULL;
363 	db_sum_list_next(nbr);
364 }
365 
366 /* timers */
367 /* ARGSUSED */
368 void
369 db_tx_timer(int fd, short event, void *arg)
370 {
371 	struct nbr *nbr = arg;
372 	struct timeval tv;
373 
374 	switch (nbr->state) {
375 	case NBR_STA_DOWN:
376 	case NBR_STA_ATTEMPT:
377 	case NBR_STA_INIT:
378 	case NBR_STA_2_WAY:
379 	case NBR_STA_SNAP:
380 		return ;
381 	case NBR_STA_XSTRT:
382 	case NBR_STA_XCHNG:
383 	case NBR_STA_LOAD:
384 	case NBR_STA_FULL:
385 		send_db_description(nbr);
386 		break;
387 	default:
388 		log_debug("db_tx_timer: neighbor ID %s: unknown neighbor state",
389 		    inet_ntoa(nbr->id));
390 		break;
391 	}
392 
393 	/* reschedule db_tx_timer but only in master mode */
394 	if (nbr->dd_master) {
395 		timerclear(&tv);
396 		tv.tv_sec = nbr->iface->rxmt_interval;
397 		if (evtimer_add(&nbr->db_tx_timer, &tv) == -1)
398 			fatal("db_tx_timer");
399 	}
400 }
401 
402 void
403 start_db_tx_timer(struct nbr *nbr)
404 {
405 	struct timeval	tv;
406 
407 	if (nbr == nbr->iface->self)
408 		return;
409 
410 	timerclear(&tv);
411 	if (evtimer_add(&nbr->db_tx_timer, &tv) == -1)
412 		fatal("start_db_tx_timer");
413 }
414 
415 void
416 stop_db_tx_timer(struct nbr *nbr)
417 {
418 	if (nbr == nbr->iface->self)
419 		return;
420 
421 	if (evtimer_del(&nbr->db_tx_timer) == -1)
422 		fatal("stop_db_tx_timer");
423 }
424