xref: /netbsd-src/usr.sbin/ldpd/fsm.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* $NetBSD: fsm.c,v 1.15 2014/03/18 18:20:47 riastradh Exp $ */
2 
3 /*-
4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Mihai Chelaru <kefren@NetBSD.org>
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 #include <arpa/inet.h>
35 #include <netinet/in.h>
36 #include <net/if.h>
37 
38 #include <ifaddrs.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <strings.h>
42 
43 #include "ldp.h"
44 #include "ldp_peer.h"
45 #include "socketops.h"
46 #include "ldp_errors.h"
47 #include "fsm.h"
48 
49 char            my_ldp_id[20];
50 struct sockaddr	mplssockaddr;
51 
52 /* Process a hello */
53 void
54 run_ldp_hello(const struct ldp_pdu * pduid, const struct hello_tlv * ht,
55     const struct sockaddr * padd, const struct in_addr * ladd, int mysock,
56     bool may_connect)
57 {
58 	struct ldp_peer *peer = NULL;
59 	const struct transport_address_tlv *trtlv;
60 	struct hello_info *hi = NULL;
61 	union sockunion traddr;
62 
63 	if ((!pduid) || (!ht))
64 		return;
65 
66 	debugp("Hello received for address: %s\n", inet_ntoa(*ladd));
67 	debugp("Hello: Type: 0x%.4X Length: %.2d ID: %.8X\n", ht->type,
68 	    ht->length, ht->messageid);
69 
70 	if (ht->length <= 4)	/* Common hello parameters */
71 		return;
72 	debugp("Common hello Type: 0x%.4X Length: %.2d"
73 	    " Hold time: %d\n", ntohs(ht->ch.type), ntohs(ht->ch.length),
74 	    ht->ch.holdtime);
75 
76 	memset(&traddr, 0, sizeof(traddr));
77 	/* Check transport TLV */
78 	if (pduid->length - PDU_PAYLOAD_LENGTH -
79 	    sizeof(struct hello_tlv) >= 8) {
80 		trtlv = (const struct transport_address_tlv *)(ht + 1);
81 		if (trtlv->type == htons(TLV_IPV4_TRANSPORT)) {
82 			traddr.sin.sin_family = AF_INET;
83 			traddr.sin.sin_len = sizeof(struct sockaddr_in);
84 			memcpy(&traddr.sin.sin_addr,
85 			    &trtlv->address, sizeof(struct in_addr));
86 		} else if (trtlv->type == htons(TLV_IPV6_TRANSPORT)) {
87 			traddr.sin6.sin6_family = AF_INET6;
88 			traddr.sin6.sin6_len = sizeof(struct sockaddr_in6);
89 			memcpy(&traddr.sin6.sin6_addr,
90 			    &trtlv->address, sizeof(struct in6_addr));
91 		} else
92 			warnp("Unknown AF %x for transport address\n",
93 			    ntohs(trtlv->type));
94 	} else {
95 		/* Use LDP ID as transport address */
96 		traddr.sin.sin_family = AF_INET;
97 		traddr.sin.sin_len = sizeof(struct sockaddr_in);
98 		memcpy(&traddr.sin.sin_addr,
99 		    &pduid->ldp_id, sizeof(struct in_addr));
100 	}
101 	/* Add it to hello list or just update timer */
102 	SLIST_FOREACH(hi, &hello_info_head, infos)
103 		if (hi->ldp_id.s_addr == pduid->ldp_id.s_addr &&
104 		    sockaddr_cmp(&hi->transport_address.sa, &traddr.sa) == 0)
105 			break;
106 	if (hi == NULL) {
107 		hi = calloc(1, sizeof(*hi));
108 		if (!hi) {
109 			fatalp("Cannot alloc a hello info structure");
110 			return;
111 		}
112 		hi->ldp_id.s_addr = pduid->ldp_id.s_addr;
113 		memcpy(&hi->transport_address, &traddr, traddr.sa.sa_len);
114 		SLIST_INSERT_HEAD(&hello_info_head, hi, infos);
115 		may_connect = false;
116 	}
117 
118 	/* Update expire timer */
119 	if (ht->ch.holdtime != 0)
120 		hi->keepalive = ntohs(ht->ch.holdtime);
121 	else {
122 		if (ntohs(ht->ch.res) >> 15 == 0)
123 			hi->keepalive = LDP_HELLO_KEEP;
124 		else
125 			hi->keepalive = LDP_THELLO_KEEP;
126 	}
127 
128 	if (!get_ldp_peer_by_id(&pduid->ldp_id)) {
129 		/*
130 		 * RFC 5036 2.5.2: If A1 > A2, LSR1 plays the active role;
131 		 * otherwise it is passive.
132 		 */
133 		if (may_connect == true &&
134 		    (hi->transport_address.sa.sa_family == AF_INET &&
135 		    ntohl(hi->transport_address.sin.sin_addr.s_addr) <
136 		    ntohl(ladd->s_addr))) {
137 			peer = ldp_peer_new(&pduid->ldp_id, padd,
138 				&hi->transport_address.sa,
139 				ntohs(ht->ch.holdtime), 0);
140 			if (peer == NULL)
141 				return;
142 			if (peer->state == LDP_PEER_CONNECTED)
143 				send_initialize(peer);
144 		}
145 	}
146 }
147 
148 struct address_list_tlv *
149 build_address_list_tlv(void)
150 {
151 	struct address_list_tlv *t;
152 	struct ifaddrs *ifa, *ifb;
153 	struct sockaddr_in *sa;
154 	struct in_addr *ia;
155 	uint16_t       adrcount = 0;
156 
157 	if (getifaddrs(&ifa) == -1)
158 		return NULL;
159 
160 	/* Find out the number of addresses */
161 	/* Ignore loopback */
162 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
163 		if ((ifb->ifa_addr->sa_family == AF_INET) &&
164 		    (ifb->ifa_flags & IFF_UP)) {
165 			sa = (struct sockaddr_in *) ifb->ifa_addr;
166 			if (ntohl(sa->sin_addr.s_addr) >> 24 != IN_LOOPBACKNET)
167 				adrcount++;
168 		}
169 	t = malloc(sizeof(*t) + (adrcount - 1) * sizeof(struct in_addr));
170 
171 	if (!t) {
172 		fatalp("build_address_list_tlv: malloc problem\n");
173 		freeifaddrs(ifa);
174 		return NULL;
175 	}
176 
177 	t->type = htons(LDP_ADDRESS);
178 	t->length = htons(sizeof(struct address_list_tlv) - TLV_TYPE_LENGTH
179 			  + (adrcount - 1) * sizeof(struct in_addr));
180 	t->messageid = htonl(get_message_id());
181 
182 	t->a_type = htons(TLV_ADDRESS_LIST);
183 	t->a_length = htons(sizeof(t->a_af) +
184 	    adrcount * sizeof(struct in_addr));
185 	t->a_af = htons(LDP_AF_INET);
186 
187 	ia = &t->a_address;
188 	for (adrcount = 0, ifb = ifa; ifb; ifb = ifb->ifa_next) {
189 		if ((ifb->ifa_addr->sa_family != AF_INET) ||
190 		    (!(ifb->ifa_flags & IFF_UP)))
191 			continue;
192 		sa = (struct sockaddr_in *) ifb->ifa_addr;
193 		if (ntohl(sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET)
194 			continue;
195 		memcpy(&ia[adrcount], &sa->sin_addr, sizeof(struct in_addr));
196 		adrcount++;
197 	}
198 	freeifaddrs(ifa);
199 
200 	return t;
201 }
202 
203 /*
204  * Calculate LDP ID
205  * Get also mpls pseudo-interface address
206  */
207 int
208 set_my_ldp_id()
209 {
210 	struct ifaddrs *ifa, *ifb;
211 	struct in_addr  a;
212 	struct sockaddr_in *sa;
213 
214 	a.s_addr = 0;
215 	my_ldp_id[0] = '\0';
216 	mplssockaddr.sa_len = 0;
217 
218 	if (getifaddrs(&ifa) == -1)
219 		return LDP_E_GENERIC;
220 
221 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
222 		if(ifb->ifa_flags & IFF_UP) {
223 			if (strncmp("mpls", ifb->ifa_name, 4) == 0 &&
224 			    ifb->ifa_addr->sa_family == AF_LINK)
225 				memcpy(&mplssockaddr, ifb->ifa_addr,
226 				    ifb->ifa_addr->sa_len);
227 
228 			if (ifb->ifa_addr->sa_family != AF_INET)
229 				continue;
230 
231 			sa = (struct sockaddr_in *) ifb->ifa_addr;
232 			if (ntohl(sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET)
233 				continue;	/* No 127/8 */
234 			if (ntohl(sa->sin_addr.s_addr) > ntohl(a.s_addr))
235 				a.s_addr = sa->sin_addr.s_addr;
236 		}
237 	freeifaddrs(ifa);
238 	debugp("LDP ID: %s\n", inet_ntoa(a));
239 	strlcpy(my_ldp_id, inet_ntoa(a), INET_ADDRSTRLEN);
240 	setproctitle("LDP ID: %s", my_ldp_id);
241 	return LDP_E_OK;
242 }
243