xref: /netbsd-src/usr.sbin/ldpd/fsm.c (revision a4ddc2c8fb9af816efe3b1c375a5530aef0e89e9)
1 /* $NetBSD: fsm.c,v 1.10 2013/02/05 13:02:33 kefren 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 /* Processing a hello */
53 void
54 run_ldp_hello(struct ldp_pdu * pduid, struct hello_tlv * ht,
55     struct sockaddr * padd, struct in_addr * ladd, int mysock, bool may_connect)
56 {
57 	struct ldp_peer *peer = NULL;
58 	struct transport_address_tlv *trtlv;
59 	struct hello_info *hi = NULL;
60 	union sockunion traddr;
61 
62 	if ((!pduid) || (!ht))
63 		return;
64 
65 	debugp("Hello received for address: %s\n", inet_ntoa(*ladd));
66 	debugp("Hello: Type: 0x%.4X Length: %.2d ID: %.8X\n", ht->type,
67 	    ht->length, ht->messageid);
68 
69 	if (ht->length <= 4)	/* Common hello parameters */
70 		return;
71 	ht->ch.type = ntohs(ht->ch.type);
72 	ht->ch.length = ntohs(ht->ch.length);
73 	ht->ch.holdtime = ntohs(ht->ch.holdtime);
74 	ht->ch.res = ntohs(ht->ch.res);
75 	debugp("Common hello Type: 0x%.4X Length: %.2d R:%d T:%d"
76 	    " Hold time: %d\n", ht->ch.type, ht->ch.length,
77 	    ht->ch.tr / 2, ht->ch.tr % 2, ht->ch.holdtime);
78 
79 	memset(&traddr, 0, sizeof(traddr));
80 	/* Check transport TLV */
81 	if (pduid->length - PDU_PAYLOAD_LENGTH -
82 	    sizeof(struct hello_tlv) >= 8) {
83 		trtlv = (struct transport_address_tlv *)(ht + 1);
84 		if (trtlv->type == htons(TLV_IPV4_TRANSPORT)) {
85 			traddr.sin.sin_family = AF_INET;
86 			traddr.sin.sin_len = sizeof(struct sockaddr_in);
87 			memcpy(&traddr.sin.sin_addr,
88 			    &trtlv->address, sizeof(struct in_addr));
89 		} else if (trtlv->type == htons(TLV_IPV6_TRANSPORT)) {
90 			traddr.sin6.sin6_family = AF_INET6;
91 			traddr.sin6.sin6_len = sizeof(struct sockaddr_in6);
92 			memcpy(&traddr.sin6.sin6_addr,
93 			    &trtlv->address, sizeof(struct in6_addr));
94 		} else
95 			warnp("Unknown AF %x for transport address\n",
96 			    ntohs(trtlv->type));
97 	} else {
98 		/* Use LDP ID as transport address */
99 		traddr.sin.sin_family = AF_INET;
100 		traddr.sin.sin_len = sizeof(struct sockaddr_in);
101 		memcpy(&traddr.sin.sin_addr,
102 		    &pduid->ldp_id, sizeof(struct in_addr));
103 	}
104 	/* Add it to hello list or just update timer */
105 	SLIST_FOREACH(hi, &hello_info_head, infos)
106 		if (hi->ldp_id.s_addr == pduid->ldp_id.s_addr &&
107 		    sockaddr_cmp(&hi->transport_address.sa, &traddr.sa) == 0)
108 			break;
109 	if (hi == NULL) {
110 		hi = calloc(1, sizeof(*hi));
111 		if (!hi) {
112 			fatalp("Cannot alloc a hello info structure");
113 			return;
114 		}
115 		hi->ldp_id.s_addr = pduid->ldp_id.s_addr;
116 		memcpy(&hi->transport_address, &traddr, traddr.sa.sa_len);
117 		SLIST_INSERT_HEAD(&hello_info_head, hi, infos);
118 	}
119 
120 	/* Update expire timer */
121 	if (ht->ch.holdtime != 0)
122 		hi->keepalive = ht->ch.holdtime;
123 	else {
124 		if (ht->ch.res >> 15 == 0)
125 			hi->keepalive = LDP_HELLO_KEEP;
126 		else
127 			hi->keepalive = LDP_THELLO_KEEP;
128 	}
129 
130 	if (!get_ldp_peer_by_id(&pduid->ldp_id)) {
131 		/*
132 		 * RFC 5036 2.5.2: If A1 > A2, LSR1 plays the active role;
133 		 * otherwise it is passive.
134 		 */
135 		if (may_connect == true &&
136 		    (hi->transport_address.sa.sa_family == AF_INET &&
137 		    ntohl(hi->transport_address.sin.sin_addr.s_addr) <
138 		    ntohl(ladd->s_addr))) {
139 			peer = ldp_peer_new(&pduid->ldp_id, padd,
140 				&hi->transport_address.sa,
141 				ht->ch.holdtime, 0);
142 			if (peer == NULL)
143 				return;
144 			if (peer->state == LDP_PEER_CONNECTED)
145 				send_initialize(peer);
146 		}
147 	}
148 }
149 
150 struct address_list_tlv *
151 build_address_list_tlv(void)
152 {
153 	struct address_list_tlv *t;
154 	struct ifaddrs *ifa, *ifb;
155 	struct sockaddr_in *sa;
156 	struct in_addr *ia;
157 	uint16_t       adrcount = 0;
158 
159 	if (getifaddrs(&ifa) == -1)
160 		return NULL;
161 
162 	/* Find out the number of addresses */
163 	/* Ignore loopback */
164 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
165 		if ((ifb->ifa_addr->sa_family == AF_INET) &&
166 		    (ifb->ifa_flags & IFF_UP)) {
167 			sa = (struct sockaddr_in *) ifb->ifa_addr;
168 			if (ntohl(sa->sin_addr.s_addr) >> 24 != IN_LOOPBACKNET)
169 				adrcount++;
170 		}
171 	t = malloc(sizeof(*t) + (adrcount - 1) * sizeof(struct in_addr));
172 
173 	if (!t) {
174 		fatalp("build_address_list_tlv: malloc problem\n");
175 		freeifaddrs(ifa);
176 		return NULL;
177 	}
178 
179 	t->type = htons(LDP_ADDRESS);
180 	t->length = htons(sizeof(struct address_list_tlv) - TLV_TYPE_LENGTH
181 			  + (adrcount - 1) * sizeof(struct in_addr));
182 	t->messageid = htonl(get_message_id());
183 
184 	t->a_type = htons(TLV_ADDRESS_LIST);
185 	t->a_length = htons(sizeof(t->a_af) +
186 	    adrcount * sizeof(struct in_addr));
187 	t->a_af = htons(LDP_AF_INET);
188 
189 	ia = &t->a_address;
190 	for (adrcount = 0, ifb = ifa; ifb; ifb = ifb->ifa_next) {
191 		if ((ifb->ifa_addr->sa_family != AF_INET) ||
192 		    (!(ifb->ifa_flags & IFF_UP)) ||
193 		    (ifb->ifa_flags & IFF_LOOPBACK))
194 			continue;
195 		sa = (struct sockaddr_in *) ifb->ifa_addr;
196 		memcpy(&ia[adrcount], &sa->sin_addr, sizeof(struct in_addr));
197 		adrcount++;
198 	}
199 	freeifaddrs(ifa);
200 
201 	add_my_if_addrs(ia, adrcount);
202 	return t;
203 }
204 
205 /*
206  * Calculate LDP ID
207  * Get also mpls pseudo-interface address
208  */
209 int
210 set_my_ldp_id()
211 {
212 	struct ifaddrs *ifa, *ifb;
213 	struct in_addr  a;
214 	struct sockaddr_in *sa;
215 
216 	a.s_addr = 0;
217 	my_ldp_id[0] = '\0';
218 	mplssockaddr.sa_len = 0;
219 
220 	if (getifaddrs(&ifa) == -1)
221 		return LDP_E_GENERIC;
222 
223 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
224 		if(ifb->ifa_flags & IFF_UP) {
225 			if (strncmp("mpls", ifb->ifa_name, 4) == 0 &&
226 			    ifb->ifa_addr->sa_family == AF_LINK)
227 				memcpy(&mplssockaddr, ifb->ifa_addr,
228 				    ifb->ifa_addr->sa_len);
229 
230 			if (ifb->ifa_addr->sa_family != AF_INET)
231 				continue;
232 
233 			sa = (struct sockaddr_in *) ifb->ifa_addr;
234 			if (ntohl(sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET)
235 				continue;	/* No 127/8 */
236 			if (ntohl(sa->sin_addr.s_addr) > ntohl(a.s_addr))
237 				a.s_addr = sa->sin_addr.s_addr;
238 		}
239 	freeifaddrs(ifa);
240 	debugp("LDP ID: %s\n", inet_ntoa(a));
241 	strlcpy(my_ldp_id, inet_ntoa(a), INET_ADDRSTRLEN);
242 	return LDP_E_OK;
243 }
244