xref: /netbsd-src/usr.sbin/ldpd/mpls_interface.c (revision 4817a0b0b8fe9612e8ebe21a9bf2d97b95038a97)
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@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