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mpls_interface.c revision 1.6
      1 /* $NetBSD: mpls_interface.c,v 1.6 2011/06/14 11:28:51 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 (at) 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 <arpa/inet.h>
     33 #include <netinet/in.h>
     34 #include <netmpls/mpls.h>
     35 #include <net/route.h>
     36 
     37 #include <sys/param.h>
     38 
     39 #include <assert.h>
     40 #include <stdio.h>
     41 #include <string.h>
     42 #include <stdlib.h>
     43 #include <unistd.h>
     44 
     45 #include "ldp.h"
     46 #include "ldp_peer.h"
     47 #include "ldp_errors.h"
     48 #include "tlv_stack.h"
     49 #include "label.h"
     50 #include "mpls_interface.h"
     51 #include "mpls_routes.h"
     52 
     53 extern int no_default_route;
     54 
     55 int
     56 mpls_add_label(struct ldp_peer * p, struct rt_msg * inh_rg,
     57     struct in_addr * addr, int len, int label, int rlookup)
     58 {
     59 	char            padd[20];
     60 	int             kount = 0, rv;
     61 	union sockunion *so_dest, *so_pref = NULL, *so_gate, *so_nexthop, *so_tag,
     62 		*so_oldifa = NULL, *so_ifa;
     63 	struct rt_msg   rg;
     64 	struct rt_msg	*rgp = &rg;
     65 	struct label	*lab;
     66 
     67 	strlcpy(padd, inet_ntoa(p->address), 20);
     68 	debugp("Trying to add %s/%d as label %d to peer %s\n", inet_ntoa(*addr),
     69 		len, label, padd);
     70 
     71 	/* Check if we should accept default route */
     72 	if (!len && no_default_route != 0)
     73 		return LDP_E_BAD_AF;
     74 
     75 	/* Is there a label mapping for this ? */
     76 	if (ldp_peer_get_lm(p, addr, len) == NULL)
     77 		return LDP_E_NOENT;
     78 
     79 	if (!inh_rg || (inh_rg->m_rtm.rtm_addrs & RTA_IFA) == 0) {
     80 		/*
     81 		 * XXX: Check if we have a route for that.
     82 		 * Why the hell isn't kernel inserting the route immediatly ?
     83 		 * let's loop until we have it..
     84 		 */
     85 
     86 		if ((so_dest = make_inet_union(inet_ntoa(*addr))) == NULL)
     87 			return LDP_E_MEMORY;
     88 		if (len != 32 && (so_pref = from_cidr_to_union(len)) == NULL) {
     89 			free(so_dest);
     90 			return LDP_E_MEMORY;
     91 		}
     92 		do {
     93 			if (kount == rlookup) {
     94 				debugp("No route for this prefix\n");
     95 				return LDP_E_NO_SUCH_ROUTE;
     96 			}
     97 			if (kount > 0)
     98 				debugp("Route test hit: %d\n", kount);
     99 			kount++;
    100 			/* Last time give it a higher chance */
    101 			if (kount == rlookup)
    102 				usleep(5000);
    103 
    104 			rv = get_route(rgp, so_dest, so_pref, 1);
    105 			if (rv != LDP_E_OK && len == 32)
    106 				/* Host maybe ? */
    107 				rv = get_route(rgp, so_dest, NULL, 1);
    108 		} while (rv != LDP_E_OK);
    109 
    110 		free(so_dest);
    111 		if (so_pref)
    112 			free(so_pref);
    113 
    114 	} else
    115 		rgp = inh_rg;
    116 
    117 	/* Check if it's an IPv4 route */
    118 
    119 	so_gate = (union sockunion *) rgp->m_space;
    120 	so_gate = (union sockunion *)((char*)so_gate +
    121 	    RT_ROUNDUP(so_gate->sa.sa_len));
    122 	if (rgp->m_rtm.rtm_addrs & RTA_IFA) {
    123 		int li = 1;
    124 		so_oldifa = so_gate;
    125 		if (rgp->m_rtm.rtm_addrs & RTA_NETMASK)
    126 			li++;
    127 		if (rgp->m_rtm.rtm_addrs & RTA_GENMASK)
    128 			li++;
    129 		if (rgp->m_rtm.rtm_addrs & RTA_IFP)
    130 			li++;
    131 		for (int i = 0; i < li; i++)
    132 			so_oldifa = (union sockunion *)((char*)so_oldifa +
    133 			    RT_ROUNDUP(so_oldifa->sa.sa_len));
    134 	}
    135 
    136 	if (so_gate->sa.sa_family != AF_INET) {
    137 		debugp("Failed at family check - only INET supoprted for now\n");
    138 		return LDP_E_BAD_AF;
    139 	}
    140 
    141 	/* Check if the address is bounded to the peer */
    142 	if (check_ifaddr(p, &so_gate->sin.sin_addr) == NULL) {
    143 		debugp("Failed at next-hop check\n");
    144 		return LDP_E_ROUTE_ERROR;
    145 	}
    146 
    147 	/* CHECK IF WE HAVE A BINDING FOR THAT */
    148 	lab = label_get_by_prefix(addr, len);
    149 
    150 	/* We should have a label because we have a route */
    151 	assert (lab);
    152 
    153 	if (lab->binding == MPLS_LABEL_IMPLNULL) {
    154 		change_local_label(lab, get_free_local_label());
    155 		if (!lab->binding) {
    156 			fatalp("No more free labels !!!\n");
    157 			return LDP_E_TOO_MANY_LABELS;
    158 		}
    159 	}
    160 
    161 	warnp("[mpls_add_label] Adding %s/%d as local binding %d, label %d"
    162 	    " to peer %s\n",
    163 		inet_ntoa(*addr), len, lab->binding, label, padd);
    164 
    165 	/* Modify existing label */
    166 	lab->label = label;
    167 	lab->p = p;
    168 
    169 	/* Add switching route */
    170 	so_dest = make_mpls_union(lab->binding);
    171 	so_nexthop = malloc(sizeof(*so_nexthop));
    172 	if (!so_nexthop) {
    173 		free(so_dest);
    174 		fatalp("Out of memory\n");
    175 		return LDP_E_MEMORY;
    176 	}
    177 	memcpy(so_nexthop, so_gate, so_gate->sa.sa_len);
    178 	if ((so_tag = make_mpls_union(label)) == NULL) {
    179 		free(so_dest);
    180 		free(so_nexthop);
    181 		fatalp("Out of memory\n");
    182 		return LDP_E_MEMORY;
    183 	}
    184 	if (add_route(so_dest, NULL, so_nexthop, NULL, so_tag, FREESO, RTM_ADD) != LDP_E_OK)
    185 		return LDP_E_ROUTE_ERROR;
    186 
    187 	/* Now, let's add tag to IPv4 route and point it to mpls interface */
    188 	if ((so_dest = make_inet_union(inet_ntoa(*addr))) == NULL) {
    189 		fatalp("Out of memory\n");
    190 		return LDP_E_MEMORY;
    191 	}
    192 
    193 	/* if prefixlen == 32 check if it's inserted as host
    194  	* and treat it as host. It may also be set as /32 prefix
    195  	* (thanks mlelstv for heads-up about this)
    196  	*/
    197 	if ((len == 32) && (rgp->m_rtm.rtm_flags & RTF_HOST))
    198 		so_pref = NULL;
    199 	else if ((so_pref = from_cidr_to_union(len)) == NULL) {
    200 		free(so_dest);
    201 		fatalp("Out of memory\n");
    202 		return LDP_E_MEMORY;
    203 	}
    204 
    205 	/* Add tag to route */
    206 	so_nexthop = malloc(sizeof(*so_nexthop));
    207 	if (!so_nexthop) {
    208 		free(so_dest);
    209 		if (so_pref != NULL)
    210 			free(so_pref);
    211 		fatalp("Out of memory\n");
    212 		return LDP_E_MEMORY;
    213 	}
    214 	memcpy(so_nexthop, so_gate, so_gate->sa.sa_len);
    215 	so_tag = make_mpls_union(label);
    216 	if (so_oldifa != NULL) {
    217 		so_ifa = malloc(sizeof(*so_ifa));
    218 		if (so_ifa == NULL) {
    219 			free(so_dest);
    220 			if (so_pref != NULL)
    221 				free(so_pref);
    222 			free(so_tag);
    223 			free(so_nexthop);
    224 			fatalp("Out of memory\n");
    225 			return LDP_E_MEMORY;
    226 		}
    227 		memcpy(so_ifa, so_oldifa, so_oldifa->sa.sa_len);
    228 	} else
    229 		so_ifa = NULL;
    230 	if (add_route(so_dest, so_pref, so_nexthop, so_ifa, so_tag, FREESO, RTM_CHANGE) != LDP_E_OK)
    231 		return LDP_E_ROUTE_ERROR;
    232 
    233 	debugp("Added %s/%d as label %d to peer %s\n", inet_ntoa(*addr), len,
    234 	    label, padd);
    235 
    236 	return LDP_E_OK;
    237 }
    238 
    239 int
    240 mpls_add_ldp_peer(struct ldp_peer * p)
    241 {
    242 	return LDP_E_OK;
    243 }
    244 
    245 int
    246 mpls_delete_ldp_peer(struct ldp_peer * p)
    247 {
    248 
    249 	/* Reput all the routes also to IPv4 */
    250 	label_reattach_all_peer_labels(p, LDP_READD_CHANGE);
    251 
    252 	return LDP_E_OK;
    253 }
    254 
    255 int
    256 mpls_start_ldp()
    257 {
    258 	ldp_peer_init();
    259 	label_init();
    260 
    261 	return LDP_E_OK;
    262 }
    263