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mpls_interface.c revision 1.2
      1 /* $NetBSD: mpls_interface.c,v 1.2 2010/12/09 00:10:59 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 (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 
     36 #include <sys/param.h>
     37 
     38 #include <assert.h>
     39 #include <stdio.h>
     40 #include <string.h>
     41 #include <stdlib.h>
     42 #include <unistd.h>
     43 
     44 #include "ldp.h"
     45 #include "ldp_peer.h"
     46 #include "ldp_errors.h"
     47 #include "tlv_stack.h"
     48 #include "label.h"
     49 #include "mpls_interface.h"
     50 #include "mpls_routes.h"
     51 
     52 #define ROUNDUP(a) \
     53 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
     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 	/* Don't accept default route XXX: should be option-able */
     72 	if (!len)
     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 		so_dest = make_inet_union(inet_ntoa(*addr));
     87 		if (len != 32)
     88 			so_pref = from_cidr_to_union(len);
     89 
     90 		do {
     91 			if (kount == rlookup) {
     92 				debugp("No route for this prefix\n");
     93 				return LDP_E_NO_SUCH_ROUTE;
     94 			}
     95 			kount++;
     96 			/* Last time give it a higher chance */
     97 			if (kount == rlookup)
     98 				usleep(5000);
     99 
    100 			rv = get_route(rgp, so_dest, so_pref, 1);
    101 			if (rv != LDP_E_OK && len == 32)
    102 				/* Host maybe ? */
    103 				rv = get_route(rgp, so_dest, NULL, 1);
    104 		} while (rv != LDP_E_OK);
    105 
    106 		free(so_dest);
    107 		if (so_pref)
    108 			free(so_pref);
    109 
    110 	} else
    111 		rgp = inh_rg;
    112 
    113 	/* Check if it's an IPv4 route */
    114 
    115 	so_gate = (union sockunion *) rgp->m_space;
    116 	so_gate = (union sockunion *)((char*)so_gate +
    117 	    ROUNDUP(so_gate->sa.sa_len));
    118 	if (rgp->m_rtm.rtm_addrs & RTA_IFA) {
    119 		int li = 1;
    120 		so_oldifa = so_gate;
    121 		if (rgp->m_rtm.rtm_addrs & RTA_NETMASK)
    122 			li++;
    123 		if (rgp->m_rtm.rtm_addrs & RTA_GENMASK)
    124 			li++;
    125 		if (rgp->m_rtm.rtm_addrs & RTA_IFP)
    126 			li++;
    127 		for (int i = 0; i < li; i++)
    128 			so_oldifa = (union sockunion *)((char*)so_oldifa +
    129 			    ROUNDUP(so_oldifa->sa.sa_len));
    130 	}
    131 
    132 	if (so_gate->sa.sa_family != AF_INET) {
    133 		debugp("Failed at family check - only INET supoprted for now\n");
    134 		return LDP_E_BAD_AF;
    135 	}
    136 
    137 	/* Check if the address is bounded to the peer */
    138 	if (check_ifaddr(p, &so_gate->sin.sin_addr) == NULL) {
    139 		debugp("Failed at next-hop check\n");
    140 		return LDP_E_ROUTE_ERROR;
    141 	}
    142 
    143 	/* CHECK IF WE HAVE A BINDING FOR THAT */
    144 	lab = label_get_by_prefix(addr, len);
    145 
    146 	/* We should have a label because we have a route */
    147 	assert (lab);
    148 
    149 	if (lab->binding == MPLS_LABEL_IMPLNULL) {
    150 		change_local_label(lab, get_free_local_label());
    151 		if (!lab->binding) {
    152 			fatalp("No more free labels !!!\n");
    153 			return LDP_E_TOO_MANY_LABELS;
    154 		}
    155 	}
    156 
    157 	warnp("[mpls_add_label] Adding %s/%d as local binding %d, label %d"
    158 	    " to peer %s\n",
    159 		inet_ntoa(*addr), len, lab->binding, label, padd);
    160 
    161 	/* Modify existing label */
    162 	lab->label = label;
    163 	lab->p = p;
    164 
    165 	/* Add switching route */
    166 	so_dest = make_mpls_union(lab->binding);
    167 	so_nexthop = malloc(sizeof(*so_nexthop));
    168 	if (!so_nexthop) {
    169 		fatalp("Out of memory\n");
    170 		return LDP_E_MEMORY;
    171 	}
    172 	memcpy(so_nexthop, so_gate, so_gate->sa.sa_len);
    173 	so_tag = make_mpls_union(label);
    174 	if (add_route(so_dest, NULL, so_nexthop, NULL, so_tag, FREESO, RTM_ADD) != LDP_E_OK)
    175 		return LDP_E_ROUTE_ERROR;
    176 
    177 	/* Now, let's add tag to IPv4 route and point it to mpls interface */
    178 	so_dest = make_inet_union(inet_ntoa(*addr));
    179 
    180 	/* if prefixlen == 32 check if it's inserted as host
    181  	* and treat it as host. It may also be set as /32 prefix
    182  	* (thanks mlelstv for heads-up about this)
    183  	*/
    184 	if ((len == 32) && (rgp->m_rtm.rtm_flags & RTF_HOST))
    185 		so_pref = NULL;
    186 	else
    187 		so_pref = from_cidr_to_union(len);
    188 
    189 	/* Add tag to route */
    190 	so_nexthop = malloc(sizeof(*so_nexthop));
    191 	if (!so_nexthop) {
    192 		fatalp("Out of memory\n");
    193 		return LDP_E_MEMORY;
    194 	}
    195 	memcpy(so_nexthop, so_gate, so_gate->sa.sa_len);
    196 	so_tag = make_mpls_union(label);
    197 	if (so_oldifa != NULL) {
    198 		so_ifa = malloc(sizeof(*so_ifa));
    199 		if (!so_ifa) {
    200 			fatalp("Out of memory\n");
    201 			return LDP_E_MEMORY;
    202 		}
    203 		memcpy(so_ifa, so_oldifa, so_oldifa->sa.sa_len);
    204 	} else
    205 		so_ifa = NULL;
    206 	if (add_route(so_dest, so_pref, so_nexthop, so_ifa, so_tag, FREESO, RTM_CHANGE) != LDP_E_OK)
    207 		return LDP_E_ROUTE_ERROR;
    208 
    209 	debugp("Added %s/%d as label %d to peer %s\n", inet_ntoa(*addr), len,
    210 	    label, padd);
    211 
    212 	return LDP_E_OK;
    213 }
    214 
    215 int
    216 mpls_add_ldp_peer(struct ldp_peer * p)
    217 {
    218 	return LDP_E_OK;
    219 }
    220 
    221 int
    222 mpls_delete_ldp_peer(struct ldp_peer * p)
    223 {
    224 
    225 	/* Reput all the routes also to IPv4 */
    226 	label_reattach_all_peer_labels(p, LDP_READD_CHANGE);
    227 
    228 	return LDP_E_OK;
    229 }
    230 
    231 int
    232 mpls_start_ldp()
    233 {
    234 	ldp_peer_init();
    235 	label_init();
    236 
    237 	return LDP_E_OK;
    238 }
    239