xref: /netbsd-src/usr.sbin/ldpd/socketops.c (revision 975a152cfcdb39ae6e496af647af0c7275ca0b61)
1 /* $NetBSD: socketops.c,v 1.31 2013/07/27 14:35:41 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/stat.h>
34 #include <sys/socket.h>
35 #include <sys/ioctl.h>
36 #include <net/if.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
39 
40 #include <assert.h>
41 #include <errno.h>
42 #include <ifaddrs.h>
43 #include <poll.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <strings.h>
48 #include <unistd.h>
49 
50 #include "conffile.h"
51 #include "fsm.h"
52 #include "ldp.h"
53 #include "ldp_command.h"
54 #include "tlv.h"
55 #include "ldp_peer.h"
56 #include "notifications.h"
57 #include "tlv_stack.h"
58 #include "mpls_interface.h"
59 #include "label.h"
60 #include "mpls_routes.h"
61 #include "ldp_errors.h"
62 #include "socketops.h"
63 
64 int ls;				/* TCP listening socket on port 646 */
65 int route_socket;		/* used to see when a route is added/deleted */
66 int command_socket;		/* Listening socket for interface command */
67 int current_msg_id = 0x233;
68 int command_port = LDP_COMMAND_PORT;
69 extern int      replay_index;
70 extern struct rt_msg replay_rt[REPLAY_MAX];
71 extern struct com_sock	csockets[MAX_COMMAND_SOCKETS];
72 
73 int	ldp_hello_time = LDP_HELLO_TIME;
74 int	ldp_keepalive_time = LDP_KEEPALIVE_TIME;
75 int	ldp_holddown_time = LDP_HOLDTIME;
76 int	no_default_route = 1;
77 int	loop_detection = 0;
78 bool	may_connect;
79 
80 void	recv_pdu(int);
81 void	send_hello_alarm(int);
82 __dead static void bail_out(int);
83 static void print_info(int);
84 static int bind_socket(int s, int stype);
85 static int set_tos(int);
86 static int socket_reuse_port(int);
87 static int get_local_addr(struct sockaddr_dl *, struct in_addr *);
88 static int is_hello_socket(int);
89 static int is_passive_if(const char *if_name);
90 
91 int
92 create_hello_sockets()
93 {
94 	struct ip_mreq  mcast_addr;
95 	int s, joined_groups;
96 	struct ifaddrs *ifa, *ifb;
97 	uint lastifindex;
98 #ifdef INET6
99 	struct ipv6_mreq mcast_addr6;
100 	struct sockaddr_in6 *if_sa6;
101 #endif
102 	struct hello_socket *hs;
103 
104 	SLIST_INIT(&hello_socket_head);
105 
106 	s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
107 	if (s < 0)
108 		return s;
109 	debugp("INET4 socket created (%d)\n", s);
110 	/*
111 	 * RFC5036 specifies we should listen to all subnet routers multicast
112 	 * group
113 	 */
114 	mcast_addr.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
115 
116 	if (socket_reuse_port(s) < 0)
117 		goto chs_error;
118 	/* Bind it to port 646 */
119 	if (bind_socket(s, AF_INET) == -1) {
120 		warnp("Cannot bind INET hello socket\n");
121 		goto chs_error;
122 	}
123 
124 	/* We don't need to receive back our messages */
125 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &(u_char){0},
126 	    sizeof(u_char)) == -1) {
127 		fatalp("INET setsockopt IP_MCAST_LOOP: %s\n", strerror(errno));
128 		goto chs_error;
129 	}
130 	/* Finally join the group on all interfaces */
131 	if (getifaddrs(&ifa) == -1) {
132 		fatalp("Cannot iterate interfaces\n");
133 		return -1;
134 	}
135 	lastifindex = UINT_MAX;
136 	joined_groups = 0;
137 	for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
138 		struct sockaddr_in *if_sa = (struct sockaddr_in *) ifb->ifa_addr;
139 		if (if_sa->sin_family != AF_INET || (!(ifb->ifa_flags & IFF_UP)) ||
140 		    (ifb->ifa_flags & IFF_LOOPBACK) ||
141 		    (!(ifb->ifa_flags & IFF_MULTICAST)) ||
142 		    (ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET) ||
143 		    is_passive_if(ifb->ifa_name) ||
144 		    lastifindex == if_nametoindex(ifb->ifa_name))
145 			continue;
146 		lastifindex = if_nametoindex(ifb->ifa_name);
147 
148 		mcast_addr.imr_interface.s_addr = if_sa->sin_addr.s_addr;
149 		debugp("Join IPv4 mcast on %s\n", ifb->ifa_name);
150         	if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &mcast_addr,
151 		    sizeof(mcast_addr)) == -1) {
152         	        fatalp("setsockopt ADD_MEMBER: %s\n", strerror(errno));
153 			goto chs_error;
154         	}
155 		joined_groups++;
156 		if (joined_groups == IP_MAX_MEMBERSHIPS) {
157 			warnp("Maximum group memberships reached for INET socket\n");
158 			break;
159 		}
160 	}
161 	/* TTL:1 for IPv4 */
162 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &(int){1},
163 	    sizeof(int)) == -1) {
164 		fatalp("set mcast ttl: %s\n", strerror(errno));
165 		goto chs_error;
166 	}
167 	/* TOS :0xc0 for IPv4 */
168 	if (set_tos(s) == -1) {
169 		fatalp("set_tos: %s", strerror(errno));
170 		goto chs_error;
171 	}
172 	/* we need to get the input interface for message processing */
173 	if (setsockopt(s, IPPROTO_IP, IP_RECVIF, &(uint32_t){1},
174 	    sizeof(uint32_t)) == -1) {
175 		fatalp("Cannot set IP_RECVIF\n");
176 		goto chs_error;
177 	}
178 
179 	hs = (struct hello_socket *)malloc(sizeof(*hs));
180 	if (hs == NULL) {
181 		fatalp("Cannot alloc hello_socket structure\n");
182 		goto chs_error;
183 	}
184 	hs->type = AF_INET;
185 	hs->socket = s;
186 	SLIST_INSERT_HEAD(&hello_socket_head, hs, listentry);
187 
188 #ifdef INET6
189 	/*
190 	 * Now we do the same for IPv6
191 	 */
192 	s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
193 	if (s < 0) {
194 		fatalp("Cannot create INET6 socket\n");
195 		return -1;
196 	}
197 	debugp("INET6 socket created (%d)\n", s);
198 
199 	if (socket_reuse_port(s) < 0)
200 		goto chs_error;
201 
202 	if (bind_socket(s, AF_INET6) == -1) {
203 		fatalp("Cannot bind INET6 hello socket\n");
204 		goto chs_error;
205 	}
206 
207 	if (setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
208 	    &(uint){0}, sizeof(uint)) == -1) {
209 		fatalp("INET6 setsocketopt IP_MCAST_LOOP: %s\n",
210 		    strerror(errno));
211 		goto chs_error;
212 	}
213 
214 	lastifindex = UINT_MAX;
215 	mcast_addr6.ipv6mr_multiaddr = in6addr_linklocal_allrouters;
216 	for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
217 		if_sa6 = (struct sockaddr_in6 *) ifb->ifa_addr;
218 		if (if_sa6->sin6_family != AF_INET6 ||
219 		    (!(ifb->ifa_flags & IFF_UP)) ||
220 		    (!(ifb->ifa_flags & IFF_MULTICAST)) ||
221 		    (ifb->ifa_flags & IFF_LOOPBACK) ||
222 		    is_passive_if(ifb->ifa_name) ||
223 		    IN6_IS_ADDR_LOOPBACK(&if_sa6->sin6_addr))
224 			continue;
225 		/*
226 		 * draft-ietf-mpls-ldp-ipv6-07 Section 5.1:
227 		 * Additionally, the link-local
228 		 * IPv6 address MUST be used as the source IP address in IPv6
229 		 * LDP Link Hellos.
230 		 */
231 		if (IN6_IS_ADDR_LINKLOCAL(&if_sa6->sin6_addr) == 0)
232 			continue;
233 		/* We should have only one LLADDR per interface, but... */
234 		if (lastifindex == if_nametoindex(ifb->ifa_name))
235 			continue;
236 		mcast_addr6.ipv6mr_interface = lastifindex =
237 		    if_nametoindex(ifb->ifa_name);
238 
239 		debugp("Join IPv6 mcast on %s\n", ifb->ifa_name);
240 		if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP,
241 		    (char *)&mcast_addr6, sizeof(mcast_addr6)) == -1) {
242 			fatalp("INET6 setsockopt JOIN: %s\n", strerror(errno));
243 			goto chs_error;
244 		}
245 	}
246 	freeifaddrs(ifa);
247 
248 	/* TTL: 255 for IPv6 - draft-ietf-mpls-ldp-ipv6-07 Section 9 */
249 	if (setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
250 	    &(int){255}, sizeof(int)) == -1) {
251 		fatalp("set mcast hops: %s\n", strerror(errno));
252 		goto chs_error;
253 	}
254 	if (setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO,
255 	    &(uint32_t){1}, sizeof(uint32_t)) == -1)
256 		goto chs_error;
257 
258 	hs = (struct hello_socket *)malloc(sizeof(*hs));
259 	if (hs == NULL) {
260 		fatalp("Memory alloc problem: hs\n");
261 		goto chs_error;
262 	}
263 
264 	hs->type = AF_INET6;
265 	hs->socket = s;
266 	SLIST_INSERT_HEAD(&hello_socket_head, hs, listentry);
267 #endif
268 	return 0;
269 chs_error:
270 	close(s);
271 	return -1;
272 }
273 
274 /* Check if parameter is a hello socket */
275 int
276 is_hello_socket(int s)
277 {
278 	struct hello_socket *hs;
279 
280 	SLIST_FOREACH(hs, &hello_socket_head, listentry)
281 		if (hs->socket == s)
282 			return 1;
283 	return 0;
284 }
285 
286 /* Check if interface is passive */
287 static int
288 is_passive_if(const char *if_name)
289 {
290 	struct passive_if *pif;
291 
292 	SLIST_FOREACH(pif, &passifs_head, listentry)
293 		if (strncasecmp(if_name, pif->if_name, IF_NAMESIZE) == 0)
294 			return 1;
295 	return 0;
296 }
297 
298 /* Sets the TTL to 1 as we don't want to transmit outside this subnet */
299 int
300 set_ttl(int s)
301 {
302 	int             ret;
303 	if ((ret = setsockopt(s, IPPROTO_IP, IP_TTL, &(int){1}, sizeof(int)))
304 	    == -1)
305 		fatalp("set_ttl: %s", strerror(errno));
306 	return ret;
307 }
308 
309 /* Sets TOS to 0xc0 aka IP Precedence 6 */
310 static int
311 set_tos(int s)
312 {
313 	int             ret;
314 	if ((ret = setsockopt(s, IPPROTO_IP, IP_TOS, &(int){0xc0},
315 	    sizeof(int))) == -1)
316 		fatalp("set_tos: %s", strerror(errno));
317 	return ret;
318 }
319 
320 static int
321 socket_reuse_port(int s)
322 {
323 	int ret;
324 	if ((ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &(int){1},
325 	    sizeof(int))) == -1)
326 		fatalp("socket_reuse_port: %s", strerror(errno));
327 	return ret;
328 }
329 
330 /* binds an UDP socket */
331 static int
332 bind_socket(int s, int stype)
333 {
334 	union sockunion su;
335 
336 	assert (stype == AF_INET || stype == AF_INET6);
337 
338 	if (stype == AF_INET) {
339 		su.sin.sin_len = sizeof(su.sin);
340 		su.sin.sin_family = AF_INET;
341 		su.sin.sin_addr.s_addr = htonl(INADDR_ANY);
342 		su.sin.sin_port = htons(LDP_PORT);
343 	}
344 #ifdef INET6
345 	else if (stype == AF_INET6) {
346 		su.sin6.sin6_len = sizeof(su.sin6);
347 		su.sin6.sin6_family = AF_INET6;
348 		su.sin6.sin6_addr = in6addr_any;
349 		su.sin6.sin6_port = htons(LDP_PORT);
350 	}
351 #endif
352 	if (bind(s, &su.sa, su.sa.sa_len)) {
353 		fatalp("bind_socket: %s\n", strerror(errno));
354 		return -1;
355 	}
356 	return 0;
357 }
358 
359 /* Create / bind the TCP socket */
360 int
361 create_listening_socket(void)
362 {
363 	struct sockaddr_in sa;
364 	int             s;
365 
366 	sa.sin_len = sizeof(sa);
367 	sa.sin_family = AF_INET;
368 	sa.sin_port = htons(LDP_PORT);
369 	sa.sin_addr.s_addr = htonl(INADDR_ANY);
370 
371 	s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
372 	if (s < 0)
373 		return s;
374 	if (bind(s, (struct sockaddr *) & sa, sizeof(sa))) {
375 		fatalp("bind: %s", strerror(errno));
376 		close(s);
377 		return -1;
378 	}
379 	if (listen(s, 10) == -1) {
380 		fatalp("listen: %s", strerror(errno));
381 		close(s);
382 		return -1;
383 	}
384 /*	if (set_tos(s) == -1) {
385 		fatalp("set_tos: %s", strerror(errno));
386 		close(s);
387 		return -1;
388 	}
389 */	return s;
390 }
391 
392 /*
393  * It's ugly. We need a function to pass all tlvs and create pdu but since I
394  * use UDP socket only to send hellos, I didn't bother
395  */
396 void
397 send_hello(void)
398 {
399 	struct hello_tlv *t;
400 	struct common_hello_tlv *cht;
401 	struct ldp_pdu  *spdu;
402 	struct transport_address_tlv *trtlv;
403 	void *v;
404 	struct sockaddr_in sadest;	/* Destination ALL_ROUTERS */
405 	ssize_t sb = 0;			/* sent bytes */
406 	struct ifaddrs *ifa, *ifb;
407 	struct sockaddr_in *if_sa;
408 	int ip4socket = -1;
409 	uint lastifindex;
410 	struct hello_socket *hs;
411 #ifdef INET6
412 	struct sockaddr_in6 sadest6;
413 	int ip6socket = -1;
414 #endif
415 
416 #define BASIC_HELLO_MSG_SIZE (sizeof(struct ldp_pdu) + 	/* PDU */	\
417 			TLV_TYPE_LENGTH + MSGID_SIZE +	/* Hello TLV */	\
418 			/* Common Hello TLV */				\
419 			sizeof(struct common_hello_tlv))
420 #define GENERAL_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + 			\
421 			/* Transport Address */				\
422 			sizeof(struct transport_address_tlv)
423 #define IPV4_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + 4 + sizeof(struct in_addr)
424 #define IPV6_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + 4 + sizeof(struct in6_addr)
425 
426 	if ((v = calloc(1, GENERAL_HELLO_MSG_SIZE)) == NULL) {
427 		fatalp("alloc problem in send_hello()\n");
428 		return;
429 	}
430 
431 	spdu = (struct ldp_pdu *)((char *)v);
432 	t = (struct hello_tlv *)(spdu + 1);
433 	cht = &t->ch;	/* Hello tlv struct includes CHT */
434 	trtlv = (struct transport_address_tlv *)(t + 1);
435 
436 	/* Prepare PDU envelope */
437 	spdu->version = htons(LDP_VERSION);
438 	spdu->length = htons(IPV4_HELLO_MSG_SIZE - PDU_VER_LENGTH);
439 	inet_aton(LDP_ID, &spdu->ldp_id);
440 
441 	/* Prepare Hello TLV */
442 	t->type = htons(LDP_HELLO);
443 	t->length = htons(MSGID_SIZE +
444 			sizeof(struct common_hello_tlv) +
445 			IPV4_HELLO_MSG_SIZE - BASIC_HELLO_MSG_SIZE);
446 	/*
447 	 * We used ID 0 instead of htonl(get_message_id()) because we've
448 	 * seen hellos from Cisco routers doing the same thing
449 	 */
450 	t->messageid = 0;
451 
452 	/* Prepare Common Hello attributes */
453 	cht->type = htons(TLV_COMMON_HELLO);
454 	cht->length = htons(sizeof(cht->holdtime) + sizeof(cht->res));
455 	cht->holdtime = htons(ldp_holddown_time);
456 	cht->res = 0;
457 
458 	/*
459 	 * Prepare Transport Address TLV RFC5036 says: "If this optional TLV
460 	 * is not present the IPv4 source address for the UDP packet carrying
461 	 * the Hello should be used." But we send it because everybody seems
462 	 * to do so
463 	 */
464 	trtlv->type = htons(TLV_IPV4_TRANSPORT);
465 	trtlv->length = htons(sizeof(struct in_addr));
466 	/* trtlv->address will be set for each socket */
467 
468 	/* Destination sockaddr */
469 	memset(&sadest, 0, sizeof(sadest));
470 	sadest.sin_len = sizeof(sadest);
471 	sadest.sin_family = AF_INET;
472 	sadest.sin_port = htons(LDP_PORT);
473 	sadest.sin_addr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
474 
475 	/* Find our socket */
476 	SLIST_FOREACH(hs, &hello_socket_head, listentry)
477 		if (hs->type == AF_INET) {
478 			ip4socket = hs->socket;
479 			break;
480 		}
481 	assert(ip4socket >= 0);
482 
483 	if (getifaddrs(&ifa) == -1) {
484 		free(v);
485 		fatalp("Cannot enumerate interfaces\n");
486 		return;
487 	}
488 
489 	lastifindex = UINT_MAX;
490 	/* Loop all interfaces in order to send IPv4 hellos */
491 	for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
492 		if_sa = (struct sockaddr_in *) ifb->ifa_addr;
493 		if (if_sa->sin_family != AF_INET ||
494 		    (!(ifb->ifa_flags & IFF_UP)) ||
495 		    (ifb->ifa_flags & IFF_LOOPBACK) ||
496 		    (!(ifb->ifa_flags & IFF_MULTICAST)) ||
497 		    is_passive_if(ifb->ifa_name) ||
498 		    (ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET) ||
499 		    lastifindex == if_nametoindex(ifb->ifa_name))
500 			continue;
501 
502 		/* Send only once per interface, using primary address */
503 		if (lastifindex == if_nametoindex(ifb->ifa_name))
504 			continue;
505 		lastifindex = if_nametoindex(ifb->ifa_name);
506 
507 		if (setsockopt(ip4socket, IPPROTO_IP, IP_MULTICAST_IF,
508 		    &if_sa->sin_addr, sizeof(struct in_addr)) == -1) {
509 			warnp("setsockopt failed: %s\n", strerror(errno));
510 			continue;
511 		}
512 		trtlv->address.ip4addr.s_addr = if_sa->sin_addr.s_addr;
513 
514 		/* Put it on the wire */
515 		sb = sendto(ip4socket, v, IPV4_HELLO_MSG_SIZE, 0,
516 			    (struct sockaddr *) & sadest, sizeof(sadest));
517 		if (sb < (ssize_t)(IPV4_HELLO_MSG_SIZE))
518 		    fatalp("send: %s", strerror(errno));
519 		else
520 		    debugp("Sent (IPv4) %zd bytes on %s"
521 			" (PDU: %d, Hello TLV: %d, CH: %d, TR: %d)\n",
522 			sb, ifb->ifa_name,
523 			ntohs(spdu->length), ntohs(t->length),
524 			ntohs(cht->length), ntohs(trtlv->length));
525 	}
526 #ifdef INET6
527 	/* Adjust lengths */
528 	spdu->length = htons(IPV6_HELLO_MSG_SIZE - PDU_VER_LENGTH);
529 	t->length = htons(MSGID_SIZE +
530 			sizeof(struct common_hello_tlv) +
531 			IPV6_HELLO_MSG_SIZE - BASIC_HELLO_MSG_SIZE);
532 	trtlv->length = htons(sizeof(struct in6_addr));
533 	trtlv->type = htons(TLV_IPV6_TRANSPORT);
534 
535 	/* Prepare destination sockaddr */
536 	memset(&sadest6, 0, sizeof(sadest6));
537 	sadest6.sin6_len = sizeof(sadest6);
538 	sadest6.sin6_family = AF_INET6;
539 	sadest6.sin6_port = htons(LDP_PORT);
540 	sadest6.sin6_addr = in6addr_linklocal_allrouters;
541 
542 	SLIST_FOREACH(hs, &hello_socket_head, listentry)
543 		if (hs->type == AF_INET6) {
544 			ip6socket = hs->socket;
545 			break;
546 		}
547 
548 	lastifindex = UINT_MAX;
549 	for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
550 		struct sockaddr_in6 * if_sa6 =
551 		    (struct sockaddr_in6 *) ifb->ifa_addr;
552 		if (if_sa6->sin6_family != AF_INET6 ||
553 		    (!(ifb->ifa_flags & IFF_UP)) ||
554 		    (!(ifb->ifa_flags & IFF_MULTICAST)) ||
555 		    (ifb->ifa_flags & IFF_LOOPBACK) ||
556 		    is_passive_if(ifb->ifa_name) ||
557 		    IN6_IS_ADDR_LOOPBACK(&if_sa6->sin6_addr))
558 			continue;
559 		/*
560 		 * draft-ietf-mpls-ldp-ipv6-07 Section 5.1:
561 		 * Additionally, the link-local
562 		 * IPv6 address MUST be used as the source IP address in IPv6
563 		 * LDP Link Hellos.
564 		 */
565 		if (IN6_IS_ADDR_LINKLOCAL(&if_sa6->sin6_addr) == 0)
566 			continue;
567 		/* We should have only one LLADDR per interface, but... */
568 		if (lastifindex == if_nametoindex(ifb->ifa_name))
569 			continue;
570 		lastifindex = if_nametoindex(ifb->ifa_name);
571 
572 		if (setsockopt(ip6socket, IPPROTO_IPV6, IPV6_MULTICAST_IF,
573 		    &lastifindex, sizeof(int)) == -1) {
574 			fatalp("ssopt6 IPV6_MULTICAST_IF failed: %s for %s\n",
575 			    strerror(errno), ifb->ifa_name);
576 			continue;
577 		}
578 
579 		memcpy(&trtlv->address.ip6addr, &if_sa6->sin6_addr,
580 		    sizeof(struct in6_addr));
581 
582 		/* Put it on the wire */
583 		sb = sendto(ip6socket, v, IPV6_HELLO_MSG_SIZE,
584 			    0, (struct sockaddr *)&sadest6, sizeof(sadest6));
585 		if (sb < (ssize_t)(IPV6_HELLO_MSG_SIZE))
586 		    fatalp("send6: %s", strerror(errno));
587 		else
588 		    debugp("Sent (IPv6) %zd bytes on %s "
589 			"(PDU: %d, Hello TLV: %d, CH: %d TR: %d)\n",
590 			sb, ifb->ifa_name, htons(spdu->length),
591 			htons(t->length), htons(cht->length),
592 			htons(trtlv->length));
593 	}
594 #endif
595 	freeifaddrs(ifa);
596 	free(v);
597 }
598 
599 int
600 get_message_id(void)
601 {
602 	current_msg_id++;
603 	return current_msg_id;
604 }
605 
606 static int
607 get_local_addr(struct sockaddr_dl *sdl, struct in_addr *sin)
608 {
609 	struct ifaddrs *ifa, *ifb;
610 	struct sockaddr_in *sinet;
611 
612 	if (sdl == NULL)
613 		return -1;
614 
615 	if (getifaddrs(&ifa) == -1)
616 		return -1;
617 	for (ifb = ifa; ifb; ifb = ifb->ifa_next)
618 		if (ifb->ifa_addr->sa_family == AF_INET) {
619 			if (if_nametoindex(ifb->ifa_name) != sdl->sdl_index)
620 				continue;
621 			sinet = (struct sockaddr_in*) ifb->ifa_addr;
622 			sin->s_addr = sinet->sin_addr.s_addr;
623 			freeifaddrs(ifa);
624 			return 0;
625 		}
626 	freeifaddrs(ifa);
627 	return -1;
628 }
629 
630 /* Receive PDUs on Multicast UDP socket */
631 void
632 recv_pdu(int sock)
633 {
634 	struct ldp_pdu  rpdu;
635 	int             c, i;
636 	struct msghdr msg;
637 	struct iovec iov[1];
638 	unsigned char recvspace[MAX_PDU_SIZE];
639 	struct hello_tlv *t;
640 	union sockunion sender;
641 	struct sockaddr_dl *sdl = NULL;
642 	struct in_addr my_ldp_addr, local_addr;
643 	struct cmsghdr *cmptr;
644 	union {
645 		struct cmsghdr cm;
646 		char control[1024];
647 	} control_un;
648 
649 	memset(&msg, 0, sizeof(msg));
650 	msg.msg_control = control_un.control;
651 	msg.msg_controllen = sizeof(control_un.control);
652 	msg.msg_flags = 0;
653 	msg.msg_name = &sender;
654 	msg.msg_namelen = sizeof(sender);
655 	iov[0].iov_base = recvspace;
656 	iov[0].iov_len = sizeof(recvspace);
657 	msg.msg_iov = iov;
658 	msg.msg_iovlen = 1;
659 
660 	c = recvmsg(sock, &msg, MSG_WAITALL);
661 
662 	/* Check to see if this is larger than MIN_PDU_SIZE */
663 	if (c < MIN_PDU_SIZE)
664 		return;
665 
666 	/* Read the PDU */
667 	i = get_pdu(recvspace, &rpdu);
668 
669 	debugp("recv_pdu(%d): PDU(size: %d) from: %s\n", sock,
670 	    c, satos(&sender.sa));
671 
672 	/* We currently understand Version 1 */
673 	if (rpdu.version != LDP_VERSION) {
674 		warnp("recv_pdu: Version mismatch\n");
675 		return;
676 	}
677 
678 	/* Check if it's our hello */
679 	inet_aton(LDP_ID, &my_ldp_addr);
680 	if (rpdu.ldp_id.s_addr == my_ldp_addr.s_addr) {
681 		/* It should not be looped. We set MULTICAST_LOOP 0 */
682 		fatalp("Received our PDU. Ignoring it\n");
683 		return;
684 	}
685 
686 	if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) ||
687 	    (msg.msg_flags & MSG_CTRUNC))
688 		local_addr.s_addr = my_ldp_addr.s_addr;
689 	else {
690 		for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL;
691 		    cmptr = CMSG_NXTHDR(&msg, cmptr))
692 			if (cmptr->cmsg_level == IPPROTO_IP &&
693 			    cmptr->cmsg_type == IP_RECVIF) {
694 				sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr);
695 				break;
696 			}
697 		if (get_local_addr(sdl, &local_addr) != 0)
698 			local_addr.s_addr = my_ldp_addr.s_addr;
699 	}
700 
701 
702 	debugp("Read %d bytes from address %s Length: %.4d Version: %d\n",
703 	       c, inet_ntoa(rpdu.ldp_id), rpdu.length, rpdu.version);
704 
705 	/* Fill the TLV messages */
706 	t = get_hello_tlv(recvspace + i, c - i);
707 	run_ldp_hello(&rpdu, t, &sender.sa, &local_addr, sock, may_connect);
708 }
709 
710 void
711 send_hello_alarm(int unused)
712 {
713 	struct ldp_peer *p, *ptmp;
714 	struct hello_info *hi, *hinext;
715 	time_t          t = time(NULL);
716 	int             olderrno = errno;
717 
718 	if (may_connect == false)
719 		may_connect = true;
720 	/* Send hellos */
721 	if (!(t % ldp_hello_time))
722 		send_hello();
723 
724 	/* Timeout -- */
725 	SLIST_FOREACH(p, &ldp_peer_head, peers)
726 		p->timeout--;
727 
728 	/* Check for timeout */
729 	SLIST_FOREACH_SAFE(p, &ldp_peer_head, peers, ptmp)
730 		if (p->timeout < 1)
731 			switch (p->state) {
732 			case LDP_PEER_HOLDDOWN:
733 				debugp("LDP holddown expired for peer %s\n",
734 				       inet_ntoa(p->ldp_id));
735 				ldp_peer_delete(p);
736 				break;
737 			case LDP_PEER_ESTABLISHED:
738 			case LDP_PEER_CONNECTED:
739 				send_notification(p, 0,
740 				    NOTIF_FATAL|NOTIF_KEEP_ALIVE_TIMER_EXPIRED);
741 				warnp("Keepalive expired for %s\n",
742 				    inet_ntoa(p->ldp_id));
743 				ldp_peer_holddown(p);
744 				break;
745 			}	/* switch */
746 
747 	/* send keepalives */
748 	if (!(t % ldp_keepalive_time)) {
749 		SLIST_FOREACH(p, &ldp_peer_head, peers)
750 		    if (p->state == LDP_PEER_ESTABLISHED) {
751 			debugp("Sending KeepAlive to %s\n",
752 			    inet_ntoa(p->ldp_id));
753 			keep_alive(p);
754 		    }
755 	}
756 
757 	/* Decrement and Check hello keepalives */
758 	SLIST_FOREACH_SAFE(hi, &hello_info_head, infos, hinext) {
759 		if (hi->keepalive != 0xFFFF)
760 			hi->keepalive--;
761 		if (hi->keepalive < 1)
762 			SLIST_REMOVE(&hello_info_head, hi, hello_info, infos);
763 	}
764 
765 	/* Set the alarm again and bail out */
766 	alarm(1);
767 	errno = olderrno;
768 }
769 
770 static void
771 bail_out(int x)
772 {
773 	ldp_peer_holddown_all();
774 	flush_mpls_routes();
775 	exit(0);
776 }
777 
778 static void
779 print_info(int x)
780 {
781 	printf("Info for %s\n-------\n", LDP_ID);
782 	printf("Neighbours:\n");
783 	show_neighbours(1, NULL);
784 	printf("Bindings:\n");
785 	show_bindings(1, NULL);
786 	printf("Labels:\n");
787 	show_labels(1, NULL);
788 	printf("--------\n");
789 }
790 
791 /*
792  * The big poll that catches every single event
793  * on every socket.
794  */
795 int
796 the_big_loop(void)
797 {
798 	int		sock_error;
799 	uint32_t	i;
800 	socklen_t       sock_error_size = sizeof(int);
801 	struct ldp_peer *p;
802 	struct com_sock	*cs;
803 	struct pollfd	pfd[MAX_POLL_FDS];
804 	struct hello_socket *hs;
805 	nfds_t pollsum;
806 
807 	assert(MAX_POLL_FDS > 5);
808 
809 	SLIST_INIT(&hello_info_head);
810 
811 	signal(SIGALRM, send_hello_alarm);
812 	signal(SIGPIPE, SIG_IGN);
813 	signal(SIGINT, bail_out);
814 	signal(SIGTERM, bail_out);
815 	signal(SIGINFO, print_info);
816 
817 	/* Send first hellos in 5 seconds. Avoid No hello notifications */
818 	may_connect = false;
819 	alarm(5);
820 
821 	route_socket = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
822 	setsockopt(route_socket, SOL_SOCKET, SO_USELOOPBACK, &(int){0},
823 		sizeof(int));
824 
825 	sock_error = bind_current_routes();
826 	if (sock_error != LDP_E_OK) {
827 		fatalp("Cannot get current routes\n");
828 		return sock_error;
829 	}
830 
831 	for (;;) {
832 		pfd[0].fd = ls;
833 		pfd[0].events = POLLRDNORM;
834 		pfd[0].revents = 0;
835 
836 		pfd[1].fd = route_socket;
837 		pfd[1].events = POLLRDNORM;
838 		pfd[1].revents = 0;
839 
840 		pfd[2].fd = command_socket;
841 		pfd[2].events = POLLRDNORM;
842 		pfd[2].revents = 0;
843 
844 		/* Hello sockets */
845 		pollsum = 3;
846 		SLIST_FOREACH(hs, &hello_socket_head, listentry) {
847 			pfd[pollsum].fd = hs->socket;
848 			pfd[pollsum].events = POLLIN;
849 			pfd[pollsum].revents = 0;
850 			pollsum++;
851 		}
852 
853 		/* Command sockets */
854 		for (i=0; i < MAX_COMMAND_SOCKETS; i++)
855 			if (csockets[i].socket != -1) {
856 				if (pollsum >= MAX_POLL_FDS)
857 					break;
858 				pfd[pollsum].fd = csockets[i].socket;
859 				pfd[pollsum].events = POLLIN;
860 				pfd[pollsum].revents = 0;
861 				pollsum++;
862 			}
863 
864 		/* LDP Peer sockets */
865 		SLIST_FOREACH(p, &ldp_peer_head, peers) {
866 			if (p->socket < 1)
867 				continue;
868 			switch (p->state) {
869 			    case LDP_PEER_CONNECTED:
870 			    case LDP_PEER_ESTABLISHED:
871 				if (pollsum >= MAX_POLL_FDS)
872 					break;
873 				pfd[pollsum].fd = p->socket;
874 				pfd[pollsum].events = POLLRDNORM;
875 				pfd[pollsum].revents = 0;
876 				pollsum++;
877 				break;
878 			    case LDP_PEER_CONNECTING:
879 				if (pollsum >= MAX_POLL_FDS)
880 					break;
881 				pfd[pollsum].fd = p->socket;
882 				pfd[pollsum].events = POLLWRNORM;
883 				pfd[pollsum].revents = 0;
884 				pollsum++;
885 				break;
886 			}
887 		}
888 
889 		if (pollsum >= MAX_POLL_FDS) {
890 			fatalp("Too many sockets. Increase MAX_POLL_FDS\n");
891 			return LDP_E_TOO_MANY_FDS;
892 		}
893 		if (poll(pfd, pollsum, INFTIM) < 0) {
894 			if (errno != EINTR)
895 				fatalp("poll: %s", strerror(errno));
896 			continue;
897 		}
898 
899 		for (i = 0; i < pollsum; i++) {
900 			if ((pfd[i].revents & POLLRDNORM) ||
901 			    (pfd[i].revents & POLLIN)) {
902 				if(pfd[i].fd == ls)
903 					new_peer_connection();
904 				else if (pfd[i].fd == route_socket) {
905 					struct rt_msg xbuf;
906 					int l, rtmlen = sizeof(xbuf);
907 					/* Read at least rtm_msglen */
908 					l = recv(route_socket, &xbuf,
909 					  sizeof(u_short), MSG_PEEK);
910 					if (l == sizeof(u_short))
911 						rtmlen = xbuf.m_rtm.rtm_msglen;
912 					do {
913 						l = recv(route_socket, &xbuf,
914 						    rtmlen, MSG_WAITALL);
915 					} while ((l == -1) && (errno == EINTR));
916 
917 					if (l == -1)
918 						break;
919 
920 					check_route(&xbuf, l);
921 
922 				} else if (is_hello_socket(pfd[i].fd) == 1) {
923 					/* Receiving hello socket */
924 					recv_pdu(pfd[i].fd);
925 				} else if (pfd[i].fd == command_socket) {
926 					command_accept(command_socket);
927 				} else if ((cs = is_command_socket(pfd[i].fd))
928 						!= NULL) {
929 					command_dispatch(cs);
930 				} else {
931 					/* ldp peer socket */
932 					p = get_ldp_peer_by_socket(pfd[i].fd);
933 					if (p)
934 						recv_session_pdu(p);
935 				}
936 			} else if(pfd[i].revents & POLLWRNORM) {
937 				p = get_ldp_peer_by_socket(pfd[i].fd);
938 				if (!p)
939 					continue;
940 				assert(p->state == LDP_PEER_CONNECTING);
941 				if (getsockopt(pfd[i].fd, SOL_SOCKET, SO_ERROR,
942 				    &sock_error, &sock_error_size) != 0 ||
943 				    sock_error != 0) {
944 					ldp_peer_holddown(p);
945 					sock_error = 0;
946 				} else {
947 					p->state = LDP_PEER_CONNECTED;
948 					send_initialize(p);
949 				}
950 			}
951 		}
952 
953 		for (int ri = 0; ri < replay_index; ri++) {
954 			debugp("Replaying: PID %d, SEQ %d\n",
955 				replay_rt[ri].m_rtm.rtm_pid,
956 				replay_rt[ri].m_rtm.rtm_seq);
957 			check_route(&replay_rt[ri], sizeof(struct rt_msg));
958                 }
959 		replay_index = 0;
960 	}	/* for (;;) */
961 }
962 
963 void
964 new_peer_connection()
965 {
966 	union sockunion peer_address, my_address;
967 	struct in_addr *peer_ldp_id = NULL;
968 	struct hello_info *hi;
969 	int s;
970 
971 	s = accept(ls, &peer_address.sa,
972 		& (socklen_t) { sizeof(union sockunion) } );
973 	if (s < 0) {
974 		fatalp("accept: %s", strerror(errno));
975 		return;
976 	}
977 
978 	if (getsockname(s, &my_address.sa,
979 	    & (socklen_t) { sizeof(union sockunion) } )) {
980 		fatalp("new_peer_connection(): cannot getsockname\n");
981 		close(s);
982 		return;
983 	}
984 
985 	if (peer_address.sa.sa_family == AF_INET)
986 		peer_address.sin.sin_port = 0;
987 	else if (peer_address.sa.sa_family == AF_INET6)
988 		peer_address.sin6.sin6_port = 0;
989 	else {
990 		fatalp("Unknown peer address family\n");
991 		close(s);
992 		return;
993 	}
994 
995 	/* Already peered or in holddown ? */
996 	if (get_ldp_peer(&peer_address.sa) != NULL) {
997 		close(s);
998 		return;
999 	}
1000 
1001 	warnp("Accepted a connection from %s\n", satos(&peer_address.sa));
1002 
1003 	/* Verify if it should connect - XXX: no check for INET6 */
1004 	if (peer_address.sa.sa_family == AF_INET &&
1005 	    ntohl(peer_address.sin.sin_addr.s_addr) <
1006 	    ntohl(my_address.sin.sin_addr.s_addr)) {
1007 		fatalp("Peer %s: connect from lower ID\n",
1008 		    satos(&peer_address.sa));
1009 		close(s);
1010 		return;
1011 	}
1012 
1013 	/* Match hello info in order to get ldp_id */
1014 	SLIST_FOREACH(hi, &hello_info_head, infos) {
1015 		if (sockaddr_cmp(&peer_address.sa,
1016 		    &hi->transport_address.sa) == 0) {
1017 			peer_ldp_id = &hi->ldp_id;
1018 			break;
1019 		}
1020 	}
1021 	if (peer_ldp_id == NULL) {
1022 		warnp("Got connection from %s, but no hello info exists\n",
1023 		    satos(&peer_address.sa));
1024 		close(s);
1025 		return;
1026 	} else
1027 		ldp_peer_new(peer_ldp_id, &peer_address.sa, NULL,
1028 		    ldp_holddown_time, s);
1029 
1030 }
1031 
1032 void
1033 send_initialize(const struct ldp_peer * p)
1034 {
1035 	struct init_tlv ti;
1036 
1037 	ti.type = htons(LDP_INITIALIZE);
1038 	ti.length = htons(sizeof(struct init_tlv) - TLV_TYPE_LENGTH);
1039 	ti.messageid = htonl(get_message_id());
1040 	ti.cs_type = htons(TLV_COMMON_SESSION);
1041 	ti.cs_len = htons(CS_LEN);
1042 	ti.cs_version = htons(LDP_VERSION);
1043 	ti.cs_keepalive = htons(2 * ldp_keepalive_time);
1044 	ti.cs_adpvlim = 0;
1045 	ti.cs_maxpdulen = htons(MAX_PDU_SIZE);
1046 	ti.cs_peeraddress.s_addr = p->ldp_id.s_addr;
1047 	ti.cs_peeraddrspace = 0;
1048 
1049 	send_tlv(p, (struct tlv *) (void *) &ti);
1050 }
1051 
1052 void
1053 keep_alive(const struct ldp_peer * p)
1054 {
1055 	struct ka_tlv   kt;
1056 
1057 	kt.type = htons(LDP_KEEPALIVE);
1058 	kt.length = htons(sizeof(kt.messageid));
1059 	kt.messageid = htonl(get_message_id());
1060 
1061 	send_tlv(p, (struct tlv *) (void *) &kt);
1062 }
1063 
1064 /*
1065  * Process a message received from a peer
1066  */
1067 void
1068 recv_session_pdu(struct ldp_peer * p)
1069 {
1070 	struct ldp_pdu *rpdu;
1071 	struct address_tlv *atlv;
1072 	struct al_tlv  *altlv;
1073 	struct init_tlv	*itlv;
1074 	struct label_map_tlv *lmtlv;
1075 	struct fec_tlv *fectlv;
1076 	struct label_tlv *labeltlv;
1077 	struct notification_tlv *nottlv;
1078 	struct hello_info *hi;
1079 
1080 	int             c;
1081 	int32_t         wo = 0;
1082 	struct tlv     *ttmp;
1083 	unsigned char   recvspace[MAX_PDU_SIZE];
1084 
1085 	memset(recvspace, 0, MAX_PDU_SIZE);
1086 
1087 	do {
1088 		c = recv(p->socket, (void *) recvspace, MAX_PDU_SIZE, MSG_PEEK);
1089 	} while (c == -1 && errno == EINTR);
1090 
1091 	debugp("Ready to read %d bytes\n", c);
1092 
1093 	if (c < 1) {		/* Session closed */
1094 		warnp("Error in connection with %s\n", inet_ntoa(p->ldp_id));
1095 		ldp_peer_holddown(p);
1096 		return;
1097 	}
1098 	if (c > MAX_PDU_SIZE) {
1099 		debugp("Incoming PDU size exceeds MAX_PDU_SIZE !\n");
1100 		return;
1101 	}
1102 	if (c < MIN_PDU_SIZE) {
1103 		debugp("PDU too small received from peer %s\n",
1104 		    inet_ntoa(p->ldp_id));
1105 		return;
1106 	}
1107 	rpdu = (struct ldp_pdu *) recvspace;
1108 	do {
1109 		c = recv(p->socket, (void *) recvspace,
1110 		    ntohs(rpdu->length) + PDU_VER_LENGTH, MSG_WAITALL);
1111 	} while (c == -1 && errno == EINTR);
1112 
1113 	/* sanity check */
1114 	if (check_recv_pdu(p, rpdu, c) != 0)
1115 		return;
1116 
1117 	debugp("Read %d bytes, PDU size: %d bytes\n", c, ntohs(rpdu->length));
1118 	wo = sizeof(struct ldp_pdu);
1119 
1120 	while (wo + TLV_TYPE_LENGTH < (uint)c) {
1121 
1122 		ttmp = (struct tlv *) (&recvspace[wo]);
1123 
1124 		if ((ntohs(ttmp->type) != LDP_KEEPALIVE) &&
1125 		    (ntohs(ttmp->type) != LDP_LABEL_MAPPING)) {
1126 			debugp("Got Type: 0x%.4X (Length: %d) from %s\n",
1127 			    ntohs(ttmp->type), ntohs(ttmp->length),
1128 			    inet_ntoa(p->ldp_id));
1129 		} else
1130 			debugp("Got Type: 0x%.4X (Length: %d) from %s\n",
1131 			    ntohs(ttmp->type), ntohs(ttmp->length),
1132 			    inet_ntoa(p->ldp_id));
1133 
1134 		/* Should we get the message ? */
1135 		if (p->state != LDP_PEER_ESTABLISHED &&
1136 		    ntohs(ttmp->type) != LDP_INITIALIZE &&
1137 		    ntohs(ttmp->type) != LDP_KEEPALIVE &&
1138 		    ntohs(ttmp->type) != LDP_NOTIFICATION)
1139 			break;
1140 		/* The big switch */
1141 		switch (ntohs(ttmp->type)) {
1142 		case LDP_INITIALIZE:
1143 			itlv = (struct init_tlv *)ttmp;
1144 			/* Check size */
1145 			if (ntohs(itlv->length) <
1146 			    sizeof(struct init_tlv) - TLV_TYPE_LENGTH) {
1147 				debugp("Bad size\n");
1148 				send_notification(p, 0,
1149 				    NOTIF_BAD_PDU_LEN | NOTIF_FATAL);
1150 				ldp_peer_holddown(p);
1151 				break;
1152 			}
1153 			/* Check version */
1154 			if (ntohs(itlv->cs_version) != LDP_VERSION) {
1155 				debugp("Bad version");
1156 				send_notification(p, ntohl(itlv->messageid),
1157 					NOTIF_BAD_LDP_VER | NOTIF_FATAL);
1158 				ldp_peer_holddown(p);
1159 				break;
1160 			}
1161 			/* Check if we got any hello from this one */
1162 			SLIST_FOREACH(hi, &hello_info_head, infos)
1163 				if (hi->ldp_id.s_addr == rpdu->ldp_id.s_addr)
1164 					break;
1165 			if (hi == NULL) {
1166 			    debugp("No hello. Moving peer to holddown\n");
1167 			    send_notification(p, ntohl(itlv->messageid),
1168 				NOTIF_SESSION_REJECTED_NO_HELLO | NOTIF_FATAL);
1169 			    ldp_peer_holddown(p);
1170 			    break;
1171 			}
1172 
1173 			if (!p->master) {
1174 				send_initialize(p);
1175 				keep_alive(p);
1176 			} else {
1177 				p->state = LDP_PEER_ESTABLISHED;
1178 				p->established_t = time(NULL);
1179 				keep_alive(p);
1180 
1181 				/*
1182 				 * Recheck here ldp id because we accepted
1183 				 * connection without knowing who is it for sure
1184 				 */
1185 				p->ldp_id.s_addr = rpdu->ldp_id.s_addr;
1186 
1187 				fatalp("LDP neighbour %s is UP\n",
1188 				    inet_ntoa(p->ldp_id));
1189 				mpls_add_ldp_peer(p);
1190 				send_addresses(p);
1191 				send_all_bindings(p);
1192 			}
1193 			break;
1194 		case LDP_KEEPALIVE:
1195 			if ((p->state == LDP_PEER_CONNECTED) && (!p->master)) {
1196 				p->state = LDP_PEER_ESTABLISHED;
1197 				p->established_t = time(NULL);
1198 				fatalp("LDP neighbour %s is UP\n",
1199 				    inet_ntoa(p->ldp_id));
1200 				mpls_add_ldp_peer(p);
1201 				send_addresses(p);
1202 				send_all_bindings(p);
1203 			}
1204 			p->timeout = p->holdtime;
1205 			break;
1206 		case LDP_ADDRESS:
1207 			/* Add peer addresses */
1208 			atlv = (struct address_tlv *) ttmp;
1209 			altlv = (struct al_tlv *) (&atlv[1]);
1210 			add_ifaddresses(p, altlv);
1211 			/*
1212 			 * try to see if we have labels with null peer that
1213 			 * would match the new peer
1214 			 */
1215 			label_check_assoc(p);
1216 			print_bounded_addresses(p);
1217 			break;
1218 		case LDP_ADDRESS_WITHDRAW:
1219 			atlv = (struct address_tlv *) ttmp;
1220 			altlv = (struct al_tlv *) (&atlv[1]);
1221 			del_ifaddresses(p, altlv);
1222 			break;
1223 		case LDP_LABEL_MAPPING:
1224 			lmtlv = (struct label_map_tlv *) ttmp;
1225 			fectlv = (struct fec_tlv *) (&lmtlv[1]);
1226 			labeltlv = (struct label_tlv *)((unsigned char *)fectlv
1227 				+ ntohs(fectlv->length) + TLV_TYPE_LENGTH);
1228 			map_label(p, fectlv, labeltlv);
1229 			break;
1230 		case LDP_LABEL_REQUEST:
1231 			lmtlv = (struct label_map_tlv *) ttmp;
1232 			fectlv = (struct fec_tlv *) (&lmtlv[1]);
1233 			switch (request_respond(p, lmtlv, fectlv)) {
1234 			case LDP_E_BAD_FEC:
1235 				send_notification(p, ntohl(lmtlv->messageid),
1236 					NOTIF_UNKNOWN_TLV);
1237 				break;
1238 			case LDP_E_BAD_AF:
1239 				send_notification(p, ntohl(lmtlv->messageid),
1240 					NOTIF_UNSUPPORTED_AF);
1241 				break;
1242 			case LDP_E_NO_SUCH_ROUTE:
1243 				send_notification(p, ntohl(lmtlv->messageid),
1244 					NOTIF_NO_ROUTE);
1245 				break;
1246 			}
1247 			break;
1248 		case LDP_LABEL_WITHDRAW:
1249 			lmtlv = (struct label_map_tlv *) ttmp;
1250 			fectlv = (struct fec_tlv *) (&lmtlv[1]);
1251 			if (withdraw_label(p, fectlv) == LDP_E_OK) {
1252 				/* Send RELEASE */
1253 				prepare_release(ttmp);
1254 				send_tlv(p, ttmp);
1255 				}
1256 			break;
1257 		case LDP_LABEL_RELEASE:
1258 			/*
1259 			 * XXX: we need to make a timed queue...
1260 			 * For now I just assume peers are processing messages
1261 			 * correctly so I just ignore confirmations
1262 			 */
1263 			wo = -1;	/* Ignore rest of message */
1264 			break;
1265 		case LDP_LABEL_ABORT:
1266 		/* XXX: For now I pretend I can process everything
1267 		 * RFC 5036, Section 3.5.9.1
1268 		 * If an LSR receives a Label Abort Request Message after it
1269 		 * has responded to the Label Request in question with a Label
1270 		 * Mapping message or a Notification message, it ignores the
1271 		 * abort request.
1272 		 */
1273 			wo = -1;
1274 			break;
1275 		case LDP_NOTIFICATION:
1276 			nottlv = (struct notification_tlv *) ttmp;
1277 			nottlv->st_code = ntohl(nottlv->st_code);
1278 			fatalp("Got notification 0x%X from peer %s\n",
1279 			    nottlv->st_code, inet_ntoa(p->ldp_id));
1280 			if (nottlv->st_code >> 31) {
1281 				fatalp("LDP peer %s signalized %s\n",
1282 				    inet_ntoa(p->ldp_id),
1283 				    NOTIF_STR[(nottlv->st_code << 1) >> 1]);
1284 				ldp_peer_holddown(p);
1285 				wo = -1;
1286 			}
1287 			break;
1288 		case LDP_HELLO:
1289 			/* No hellos should came on tcp session */
1290 			wo = -1;
1291 			break;
1292 		default:
1293 			warnp("Unknown TLV received from %s\n",
1294 			    inet_ntoa(p->ldp_id));
1295 			debug_tlv(ttmp);
1296 			wo = -1;/* discard the rest of the message */
1297 			break;
1298 		}
1299 		if (wo < 0) {
1300 			debugp("Discarding the rest of the message\n");
1301 			break;
1302 		} else {
1303 			wo += ntohs(ttmp->length) + TLV_TYPE_LENGTH;
1304 			debugp("WORKED ON %u bytes (Left %d)\n", wo, c - wo);
1305 		}
1306 	}			/* while */
1307 
1308 }
1309 
1310 /* Sends a pdu, tlv pair to a connected peer */
1311 int
1312 send_message(const struct ldp_peer * p, const struct ldp_pdu * pdu,
1313 	const struct tlv * t)
1314 {
1315 	unsigned char   sendspace[MAX_PDU_SIZE];
1316 
1317 	/* Check if peer is connected */
1318 	switch (p->state) {
1319 	case LDP_PEER_CONNECTED:
1320 	case LDP_PEER_ESTABLISHED:
1321 		break;
1322 	default:
1323 		return -1;
1324 	}
1325 
1326 	/* Check length validity first */
1327 	if (ntohs(pdu->length) !=
1328 	    ntohs(t->length) + TLV_TYPE_LENGTH + PDU_PAYLOAD_LENGTH) {
1329 		fatalp("LDP: TLV - PDU incompability. Message discarded\n");
1330 		fatalp("LDP: TLV len %d - PDU len %d\n", ntohs(t->length),
1331 		    ntohs(pdu->length));
1332 		return -1;
1333 	}
1334 	if (ntohs(t->length) + PDU_VER_LENGTH > MAX_PDU_SIZE) {
1335 		fatalp("Message to large discarded\n");
1336 		return -1;
1337 	}
1338 	/* Arrange them in a buffer and send */
1339 	memcpy(sendspace, pdu, sizeof(struct ldp_pdu));
1340 	memcpy(sendspace + sizeof(struct ldp_pdu), t,
1341 	    ntohs(t->length) + TLV_TYPE_LENGTH);
1342 
1343 	/* Report keepalives only for DEBUG */
1344 	if ((ntohs(t->type) != 0x201) && (ntohs(t->type) != 0x400)) {
1345 		debugp("Sending message type 0x%.4X to %s (size: %d)\n",
1346 		    ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length));
1347 	} else
1348 	/* downgraded from warnp to debugp for now */
1349 		debugp("Sending message type 0x%.4X to %s (size: %d)\n",
1350 		    ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length));
1351 
1352 	/* Send it finally */
1353 	return send(p->socket, sendspace,
1354 		ntohs(pdu->length) + PDU_VER_LENGTH, 0);
1355 }
1356 
1357 /*
1358  * Encapsulates TLV into a PDU and sends it to a peer
1359  */
1360 int
1361 send_tlv(const struct ldp_peer * p, const struct tlv * t)
1362 {
1363 	struct ldp_pdu  pdu;
1364 
1365 	pdu.version = htons(LDP_VERSION);
1366 	inet_aton(LDP_ID, &pdu.ldp_id);
1367 	pdu.label_space = 0;
1368 	pdu.length = htons(ntohs(t->length) + TLV_TYPE_LENGTH +
1369 		PDU_PAYLOAD_LENGTH);
1370 
1371 	return send_message(p, &pdu, t);
1372 }
1373 
1374 
1375 int
1376 send_addresses(const struct ldp_peer * p)
1377 {
1378 	struct address_list_tlv *t;
1379 	int             ret;
1380 
1381 	t = build_address_list_tlv();
1382 
1383 	ret = send_tlv(p, (struct tlv *) t);
1384 	free(t);
1385 	return ret;
1386 
1387 }
1388