xref: /netbsd-src/usr.sbin/ldpd/fsm.c (revision daf6c4152fcddc27c445489775ed1f66ab4ea9a9)
1 /* $NetBSD: fsm.c,v 1.3 2010/12/13 01:25:19 christos 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("Received it on 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");
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)
95 		hi->keepalive = ht->ch.holdtime;
96 	if (!get_ldp_peer(&pduid->ldp_id)) {
97 		/* First of all set peer_addr to announced LDP_ID */
98 		memcpy(&peer_addr, &pduid->ldp_id,
99 		    sizeof(struct in_addr));
100 		/*
101 		 * Now let's see if there is any transport TLV in
102 		 * there
103 		 */
104 		if (pduid->length - PDU_PAYLOAD_LENGTH -
105 		    sizeof(struct hello_tlv) > 3) {
106 			trtlv = (struct transport_address_tlv *) &ht[1];
107 			if (trtlv->type == TLV_IPV4_TRANSPORT)
108 				memcpy(&peer_addr, &trtlv->address,
109 				    sizeof(struct in_addr));
110 		} else
111 			trtlv = NULL;
112 		/*
113 		 * RFC says: If A1 > A2, LSR1 plays the active role;
114 		 * otherwise it is passive.
115 		 */
116 		if (ntohl(peer_addr.s_addr) < ntohl(ladd->s_addr)) {
117 #define	TRADDR (trtlv && trtlv->type == TLV_IPV4_TRANSPORT) ? &peer_addr : NULL
118 			peer = ldp_peer_new(&pduid->ldp_id, padd,
119 				TRADDR, ht->ch.holdtime, 0);
120 			if (!peer)
121 				return;
122 			if (peer && peer->state == LDP_PEER_CONNECTED)
123 				send_initialize(peer);
124 		}
125 	}
126 }
127 
128 struct address_list_tlv *
129 build_address_list_tlv(void)
130 {
131 	struct address_list_tlv *t;
132 	struct ifaddrs *ifa, *ifb;
133 	struct sockaddr_in *sa;
134 	struct in_addr *ia;
135 	uint16_t       adrcount = 0;
136 
137 	if (getifaddrs(&ifa) == -1)
138 		return NULL;
139 
140 	/* Find out the number of addresses */
141 	/* Ignore loopback */
142 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
143 		if ((ifb->ifa_addr->sa_family == AF_INET) &&
144 		    (ifb->ifa_flags & IFF_UP)) {
145 			sa = (struct sockaddr_in *) ifb->ifa_addr;
146 			if (sa->sin_addr.s_addr << 24 >> 24 != 127)
147 				adrcount++;
148 		}
149 	t = malloc(sizeof(*t) + (adrcount - 1) * sizeof(struct in_addr));
150 
151 	if (!t) {
152 		fatalp("build_address_list_tlv: malloc problem\n");
153 		return NULL;
154 	}
155 
156 	t->type = htons(LDP_ADDRESS);
157 	t->length = htons(sizeof(struct address_list_tlv) - TLV_TYPE_LENGTH
158 			  + (adrcount - 1) * sizeof(struct in_addr));
159 	t->messageid = htonl(get_message_id());
160 
161 	t->a_type = htons(TLV_ADDRESS_LIST);
162 	t->a_length = htons(sizeof(t->a_af) +
163 	    adrcount * sizeof(struct in_addr));
164 	t->a_af = htons(LDP_AF_INET);
165 
166 	ia = &t->a_address;
167 	for (adrcount = 0, ifb = ifa; ifb; ifb = ifb->ifa_next) {
168 		if ((ifb->ifa_addr->sa_family != AF_INET) ||
169 		    (!(ifb->ifa_flags & IFF_UP)) ||
170 		    (ifb->ifa_flags & IFF_LOOPBACK))
171 			continue;
172 		sa = (struct sockaddr_in *) ifb->ifa_addr;
173 		memcpy(&ia[adrcount], &sa->sin_addr, sizeof(struct in_addr));
174 		adrcount++;
175 	}
176 	freeifaddrs(ifa);
177 
178 	add_my_if_addrs(ia, adrcount);
179 	return t;
180 }
181 
182 /*
183  * Calculate LDP ID
184  * Get also mpls pseudo-interface address
185  */
186 int
187 set_my_ldp_id()
188 {
189 	struct ifaddrs *ifa, *ifb;
190 	struct in_addr  a;
191 	struct sockaddr_in *sa;
192 
193 	a.s_addr = 0;
194 	my_ldp_id[0] = 0;
195 	mplssockaddr.sa_len = 0;
196 
197 	if (getifaddrs(&ifa) == -1)
198 		return LDP_E_GENERIC;
199 
200 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
201 		if(ifb->ifa_flags & IFF_UP) {
202 			if (strncmp("mpls", ifb->ifa_name, 4) == 0 &&
203 			    ifb->ifa_addr->sa_family == AF_LINK)
204 				memcpy(&mplssockaddr, ifb->ifa_addr,
205 				    ifb->ifa_addr->sa_len);
206 
207 			if (ifb->ifa_addr->sa_family != AF_INET)
208 				continue;
209 
210 			sa = (struct sockaddr_in *) ifb->ifa_addr;
211 			if (ntohl(sa->sin_addr.s_addr) >> 24 == 127)
212 				continue;	/* No 127/8 */
213 			if (ntohl(sa->sin_addr.s_addr) > ntohl(a.s_addr))
214 				a.s_addr = sa->sin_addr.s_addr;
215 		}
216 	freeifaddrs(ifa);
217 	debugp("LDP ID: %s\n", inet_ntoa(a));
218 	strlcpy(my_ldp_id, inet_ntoa(a), INET_ADDRSTRLEN);
219 	return LDP_E_OK;
220 }
221