xref: /netbsd-src/usr.sbin/ldpd/fsm.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /* $NetBSD: fsm.c,v 1.5 2011/06/16 14:48:30 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 in_addr * padd, struct in_addr * ladd, int mysock)
56 {
57 	struct ldp_peer *peer = NULL;
58 	struct in_addr  peer_addr;
59 	struct transport_address_tlv *trtlv;
60 	struct hello_info *hi;
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 	/* Add it to hello list or just update timer */
70 	SLIST_FOREACH(hi, &hello_info_head, infos)
71 		if (hi->ldp_id.s_addr == pduid->ldp_id.s_addr)
72 			break;
73 	if (hi == NULL) {
74 		hi = malloc(sizeof(*hi));
75 		if (!hi) {
76 			fatalp("Cannot alloc a hello info structure");
77 			return;
78 		}
79 		hi->ldp_id.s_addr = pduid->ldp_id.s_addr;
80 		SLIST_INSERT_HEAD(&hello_info_head, hi, infos);
81 	} else
82 		/* Just update timer */
83 		hi->keepalive = LDP_HELLO_KEEP;
84 
85 	if (ht->length <= 4)	/* Common hello parameters */
86 		return;
87 	ht->ch.type = ntohs(ht->ch.type);
88 	ht->ch.length = ntohs(ht->ch.length);
89 	ht->ch.holdtime = ntohs(ht->ch.holdtime);
90 	ht->ch.res = ntohs(ht->ch.res);
91 	debugp("Common hello Type: 0x%.4X Length: %.2d R:%d T:%d"
92 	    "Hold time: %d\n", ht->ch.type, ht->ch.length,
93 	    ht->ch.tr / 2, ht->ch.tr % 2, ht->ch.holdtime);
94 	if (ht->ch.holdtime != 0)
95 		hi->keepalive = ht->ch.holdtime;
96 	else {
97 		if (ht->ch.res >> 15 == 0)
98 			hi->keepalive = LDP_HELLO_KEEP;
99 		else
100 			hi->keepalive = LDP_THELLO_KEEP;
101 	}
102 	if (!get_ldp_peer(&pduid->ldp_id)) {
103 		/* First of all set peer_addr to announced LDP_ID */
104 		memcpy(&peer_addr, &pduid->ldp_id,
105 		    sizeof(struct in_addr));
106 		/*
107 		 * Now let's see if there is any transport TLV in
108 		 * there
109 		 */
110 		if (pduid->length - PDU_PAYLOAD_LENGTH -
111 		    sizeof(struct hello_tlv) > 3) {
112 			trtlv = (struct transport_address_tlv *) &ht[1];
113 			if (trtlv->type == TLV_IPV4_TRANSPORT)
114 				memcpy(&peer_addr, &trtlv->address,
115 				    sizeof(struct in_addr));
116 		} else
117 			trtlv = NULL;
118 		/*
119 		 * RFC says: If A1 > A2, LSR1 plays the active role;
120 		 * otherwise it is passive.
121 		 */
122 		if (ntohl(peer_addr.s_addr) < ntohl(ladd->s_addr)) {
123 #define	TRADDR (trtlv && trtlv->type == TLV_IPV4_TRANSPORT) ? &peer_addr : NULL
124 			peer = ldp_peer_new(&pduid->ldp_id, padd,
125 				TRADDR, ht->ch.holdtime, 0);
126 			if (!peer)
127 				return;
128 			if (peer && peer->state == LDP_PEER_CONNECTED)
129 				send_initialize(peer);
130 		}
131 	}
132 }
133 
134 struct address_list_tlv *
135 build_address_list_tlv(void)
136 {
137 	struct address_list_tlv *t;
138 	struct ifaddrs *ifa, *ifb;
139 	struct sockaddr_in *sa;
140 	struct in_addr *ia;
141 	uint16_t       adrcount = 0;
142 
143 	if (getifaddrs(&ifa) == -1)
144 		return NULL;
145 
146 	/* Find out the number of addresses */
147 	/* Ignore loopback */
148 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
149 		if ((ifb->ifa_addr->sa_family == AF_INET) &&
150 		    (ifb->ifa_flags & IFF_UP)) {
151 			sa = (struct sockaddr_in *) ifb->ifa_addr;
152 			if (ntohl(sa->sin_addr.s_addr) >> 24 != IN_LOOPBACKNET)
153 				adrcount++;
154 		}
155 	t = malloc(sizeof(*t) + (adrcount - 1) * sizeof(struct in_addr));
156 
157 	if (!t) {
158 		fatalp("build_address_list_tlv: malloc problem\n");
159 		freeifaddrs(ifa);
160 		return NULL;
161 	}
162 
163 	t->type = htons(LDP_ADDRESS);
164 	t->length = htons(sizeof(struct address_list_tlv) - TLV_TYPE_LENGTH
165 			  + (adrcount - 1) * sizeof(struct in_addr));
166 	t->messageid = htonl(get_message_id());
167 
168 	t->a_type = htons(TLV_ADDRESS_LIST);
169 	t->a_length = htons(sizeof(t->a_af) +
170 	    adrcount * sizeof(struct in_addr));
171 	t->a_af = htons(LDP_AF_INET);
172 
173 	ia = &t->a_address;
174 	for (adrcount = 0, ifb = ifa; ifb; ifb = ifb->ifa_next) {
175 		if ((ifb->ifa_addr->sa_family != AF_INET) ||
176 		    (!(ifb->ifa_flags & IFF_UP)) ||
177 		    (ifb->ifa_flags & IFF_LOOPBACK))
178 			continue;
179 		sa = (struct sockaddr_in *) ifb->ifa_addr;
180 		memcpy(&ia[adrcount], &sa->sin_addr, sizeof(struct in_addr));
181 		adrcount++;
182 	}
183 	freeifaddrs(ifa);
184 
185 	add_my_if_addrs(ia, adrcount);
186 	return t;
187 }
188 
189 /*
190  * Calculate LDP ID
191  * Get also mpls pseudo-interface address
192  */
193 int
194 set_my_ldp_id()
195 {
196 	struct ifaddrs *ifa, *ifb;
197 	struct in_addr  a;
198 	struct sockaddr_in *sa;
199 
200 	a.s_addr = 0;
201 	my_ldp_id[0] = '\0';
202 	mplssockaddr.sa_len = 0;
203 
204 	if (getifaddrs(&ifa) == -1)
205 		return LDP_E_GENERIC;
206 
207 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
208 		if(ifb->ifa_flags & IFF_UP) {
209 			if (strncmp("mpls", ifb->ifa_name, 4) == 0 &&
210 			    ifb->ifa_addr->sa_family == AF_LINK)
211 				memcpy(&mplssockaddr, ifb->ifa_addr,
212 				    ifb->ifa_addr->sa_len);
213 
214 			if (ifb->ifa_addr->sa_family != AF_INET)
215 				continue;
216 
217 			sa = (struct sockaddr_in *) ifb->ifa_addr;
218 			if (ntohl(sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET)
219 				continue;	/* No 127/8 */
220 			if (ntohl(sa->sin_addr.s_addr) > ntohl(a.s_addr))
221 				a.s_addr = sa->sin_addr.s_addr;
222 		}
223 	freeifaddrs(ifa);
224 	debugp("LDP ID: %s\n", inet_ntoa(a));
225 	strlcpy(my_ldp_id, inet_ntoa(a), INET_ADDRSTRLEN);
226 	return LDP_E_OK;
227 }
228