xref: /openbsd-src/usr.sbin/ospf6d/hello.c (revision 897fc685943471cf985a0fe38ba076ea6fe74fa5)
1 /*	$OpenBSD: hello.c,v 1.18 2018/02/22 07:43:29 claudio Exp $ */
2 
3 /*
4  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
5  * Copyright (c) 2004, 2005 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 <arpa/inet.h>
24 #include <sys/time.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <event.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 /* hello packet handling */
37 int
38 send_hello(struct iface *iface)
39 {
40 	struct in6_addr		 dst;
41 	struct hello_hdr	 hello;
42 	struct nbr		*nbr;
43 	struct ibuf		*buf;
44 	int			 ret;
45 	u_int32_t		 opts;
46 
47 	switch (iface->type) {
48 	case IF_TYPE_POINTOPOINT:
49 	case IF_TYPE_BROADCAST:
50 		inet_pton(AF_INET6, AllSPFRouters, &dst);
51 		break;
52 	case IF_TYPE_NBMA:
53 	case IF_TYPE_POINTOMULTIPOINT:
54 		log_debug("send_hello: type %s not supported, interface %s",
55 		    if_type_name(iface->type), iface->name);
56 		return (-1);
57 	case IF_TYPE_VIRTUALLINK:
58 		dst = iface->dst;
59 		break;
60 	default:
61 		fatalx("send_hello: unknown interface type");
62 	}
63 
64 	/* XXX IBUF_READ_SIZE */
65 	if ((buf = ibuf_dynamic(PKG_DEF_SIZE, IBUF_READ_SIZE)) == NULL)
66 		fatal("send_hello");
67 
68 	/* OSPF header */
69 	if (gen_ospf_hdr(buf, iface, PACKET_TYPE_HELLO))
70 		goto fail;
71 
72 	/* hello header */
73 	hello.iface_id = htonl(iface->ifindex);
74 	LSA_24_SETHI(hello.opts, iface->priority);
75 	opts = area_ospf_options(area_find(oeconf, iface->area_id));
76 	LSA_24_SETLO(hello.opts, opts);
77 	hello.opts = htonl(hello.opts);
78 
79 	hello.hello_interval = htons(iface->hello_interval);
80 	hello.rtr_dead_interval = htons(iface->dead_interval);
81 
82 	if (iface->dr) {
83 		hello.d_rtr = iface->dr->id.s_addr;
84 		iface->self->dr.s_addr = iface->dr->id.s_addr;
85 	} else
86 		hello.d_rtr = 0;
87 	if (iface->bdr) {
88 		hello.bd_rtr = iface->bdr->id.s_addr;
89 		iface->self->bdr.s_addr = iface->bdr->id.s_addr;
90 	} else
91 		hello.bd_rtr = 0;
92 
93 	if (ibuf_add(buf, &hello, sizeof(hello)))
94 		goto fail;
95 
96 	/* active neighbor(s) */
97 	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
98 		if ((nbr->state >= NBR_STA_INIT) && (nbr != iface->self))
99 			if (ibuf_add(buf, &nbr->id, sizeof(nbr->id)))
100 				goto fail;
101 	}
102 
103 	/* calculate checksum */
104 	if (upd_ospf_hdr(buf, iface))
105 		goto fail;
106 
107 	ret = send_packet(iface, buf->buf, buf->wpos, &dst);
108 
109 	ibuf_free(buf);
110 	return (ret);
111 fail:
112 	log_warn("send_hello");
113 	ibuf_free(buf);
114 	return (-1);
115 }
116 
117 void
118 recv_hello(struct iface *iface, struct in6_addr *src, u_int32_t rtr_id,
119     char *buf, u_int16_t len)
120 {
121 	struct hello_hdr	 hello;
122 	struct nbr		*nbr = NULL, *dr;
123 	struct area		*area;
124 	u_int32_t		 nbr_id, opts;
125 	int			 nbr_change = 0;
126 
127 	if (len < sizeof(hello) || (len & 0x03)) {
128 		log_warnx("recv_hello: bad packet size, interface %s",
129 		    iface->name);
130 		return;
131 	}
132 
133 	memcpy(&hello, buf, sizeof(hello));
134 	buf += sizeof(hello);
135 	len -= sizeof(hello);
136 
137 	if (ntohs(hello.hello_interval) != iface->hello_interval) {
138 		log_warnx("recv_hello: invalid hello-interval %d, "
139 		    "interface %s", ntohs(hello.hello_interval),
140 		    iface->name);
141 		return;
142 	}
143 
144 	if (ntohs(hello.rtr_dead_interval) != iface->dead_interval) {
145 		log_warnx("recv_hello: invalid router-dead-interval %d, "
146 		    "interface %s", ntohl(hello.rtr_dead_interval),
147 		    iface->name);
148 		return;
149 	}
150 
151 	if ((area = area_find(oeconf, iface->area_id)) == NULL)
152 		fatalx("interface lost area");
153 
154 	opts = LSA_24_GETLO(ntohl(hello.opts));
155 	if ((opts & OSPF_OPTION_E && area->stub) ||
156 	    ((opts & OSPF_OPTION_E) == 0 && !area->stub)) {
157 		log_warnx("recv_hello: ExternalRoutingCapability mismatch, "
158 		    "interface %s", iface->name);
159 		return;
160 	}
161 
162 	/* match router-id */
163 	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
164 		if (nbr == iface->self)
165 			continue;
166 		if (nbr->id.s_addr == rtr_id)
167 			break;
168 	}
169 
170 	if (!nbr) {
171 		nbr = nbr_new(rtr_id, iface, ntohl(hello.iface_id), 0, src);
172 		/* set neighbor parameters */
173 		nbr->dr.s_addr = hello.d_rtr;
174 		nbr->bdr.s_addr = hello.bd_rtr;
175 		nbr->priority = LSA_24_GETHI(ntohl(hello.opts));
176 	}
177 
178 	/* actually the neighbor address shouldn't be stored on virtual links */
179 	nbr->addr = *src;
180 	nbr->options = opts;
181 
182 	nbr_fsm(nbr, NBR_EVT_HELLO_RCVD);
183 
184 	while (len >= sizeof(nbr_id)) {
185 		memcpy(&nbr_id, buf, sizeof(nbr_id));
186 		if (nbr_id == ospfe_router_id()) {
187 			/* seen myself */
188 			if (nbr->state & NBR_STA_PRELIM) {
189 				nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
190 				nbr_change = 1;
191 			}
192 			break;
193 		}
194 		buf += sizeof(nbr_id);
195 		len -= sizeof(nbr_id);
196 	}
197 
198 	if (len == 0) {
199 		nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
200 		/* set neighbor parameters */
201 		nbr->dr.s_addr = hello.d_rtr;
202 		nbr->bdr.s_addr = hello.bd_rtr;
203 		nbr->priority = LSA_24_GETHI(ntohl(hello.opts));
204 		return;
205 	}
206 
207 	if (nbr->priority != LSA_24_GETHI(ntohl(hello.opts))) {
208 		nbr->priority = LSA_24_GETHI(ntohl(hello.opts));
209 		nbr_change = 1;
210 	}
211 
212 	if (iface->state & IF_STA_WAITING &&
213 	    hello.d_rtr == nbr->id.s_addr && hello.bd_rtr == 0)
214 		if_fsm(iface, IF_EVT_BACKUP_SEEN);
215 
216 	if (iface->state & IF_STA_WAITING && hello.bd_rtr == nbr->id.s_addr) {
217 		/*
218 		 * In case we see the BDR make sure that the DR is around
219 		 * with a bidirectional (2_WAY or better) connection
220 		 */
221 		LIST_FOREACH(dr, &iface->nbr_list, entry)
222 			if (hello.d_rtr == dr->id.s_addr &&
223 			    dr->state & NBR_STA_BIDIR)
224 				if_fsm(iface, IF_EVT_BACKUP_SEEN);
225 	}
226 
227 	if ((nbr->id.s_addr == nbr->dr.s_addr &&
228 	    nbr->id.s_addr != hello.d_rtr) ||
229 	    (nbr->id.s_addr != nbr->dr.s_addr &&
230 	    nbr->id.s_addr == hello.d_rtr))
231 		/* neighbor changed from or to DR */
232 		nbr_change = 1;
233 	if ((nbr->id.s_addr == nbr->bdr.s_addr &&
234 	    nbr->id.s_addr != hello.bd_rtr) ||
235 	    (nbr->id.s_addr != nbr->bdr.s_addr &&
236 	    nbr->id.s_addr == hello.bd_rtr))
237 		/* neighbor changed from or to BDR */
238 		nbr_change = 1;
239 
240 	nbr->dr.s_addr = hello.d_rtr;
241 	nbr->bdr.s_addr = hello.bd_rtr;
242 
243 	if (nbr_change)
244 		if_fsm(iface, IF_EVT_NBR_CHNG);
245 
246 	/* TODO NBMA needs some special handling */
247 }
248