1 /*
2 * Copyright (c) 2007 The DragonFly Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 * 3. Neither the name of The DragonFly Project nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific, prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/globaldata.h>
33 #include <sys/kernel.h>
34 #include <sys/mbuf.h>
35 #include <sys/param.h>
36 #include <sys/sysctl.h>
37 #include <sys/systm.h>
38
39 #include <net/if_var.h>
40 #include <net/netisr.h>
41 #include <net/route.h>
42
43 #include <sys/mplock2.h>
44
45 #include <netproto/mpls/mpls.h>
46 #include <netproto/mpls/mpls_var.h>
47
48 struct mpls_stats mplsstats_percpu[MAXCPU];
49 struct route mplsforward_rt[MAXCPU];
50
51 int mplsforwarding = 1;
52 /*
53 SYSCTL_INT(_net_mpls, OID_AUTO, forwarding, CTLFLAG_RW,
54 &mplsforwarding, 0, "Enable MPLS forwarding between interfaces");
55 */
56
57 static void mpls_input_handler(netmsg_t);
58 static void mpls_forward(struct mbuf *);
59
60 void
mpls_init(void)61 mpls_init(void)
62 {
63 int cpu;
64
65 /*
66 * Initialize MPLS statistics counters for each CPU.
67 *
68 */
69 for (cpu = 0; cpu < ncpus; ++cpu) {
70 bzero(&mplsstats_percpu[cpu], sizeof(struct mpls_stats));
71 }
72
73 netisr_register(NETISR_MPLS, mpls_input_handler, mpls_hashfn);
74 }
75
76 static void
mpls_input_handler(netmsg_t msg)77 mpls_input_handler(netmsg_t msg)
78 {
79 struct mbuf *m = msg->packet.nm_packet;
80
81 get_mplock();
82 mpls_input(m);
83 rel_mplock();
84 /* do not reply, msg embedded in mbuf */
85 }
86
87 void
mpls_input(struct mbuf * m)88 mpls_input(struct mbuf *m)
89 {
90 struct mpls *mpls = NULL;
91 mpls_label_t label;
92
93 M_ASSERTPKTHDR(m);
94
95 mplsstat.mplss_total++;
96
97 /* length checks already performed at mpls_demux() */
98 KASSERT(m->m_pkthdr.len >= sizeof(struct mpls),
99 ("mpls_input: mpls header too small"));
100
101 again:
102 if (m->m_len < sizeof(struct mpls)) {
103 m = m_pullup(m, sizeof(struct mpls));
104 if (m == NULL) {
105 mplsstat.mplss_toosmall++;
106 return;
107 }
108 }
109
110 mpls = mtod(m, struct mpls*);
111 label = MPLS_LABEL(ntohl(mpls->mpls_shim));
112 switch (label) {
113 case 0:
114 /*
115 * Label 0: represents "IPv4 Explicit NULL Label".
116 */
117 if (MPLS_STACK(ntohl(mpls->mpls_shim))) {
118 /* Decapsulate the ip datagram from the mpls frame. */
119 m_adj(m, sizeof(struct mpls));
120 netisr_queue(NETISR_IP, m);
121 return;
122 }
123 goto again; /* If not the bottom label, per RFC4182. */
124
125 case 1:
126 /*
127 * Label 1: represents "Router Alert Label" and is valid
128 * anywhere except at the bottom of the stack.
129 */
130 break;
131
132 case 2:
133 /*
134 * Label 2: represents "IPv6 Explicit NULL Label".
135 */
136 if (MPLS_STACK(ntohl(mpls->mpls_shim))) {
137 /* Decapsulate the ip datagram from the mpls frame. */
138 m_adj(m, sizeof(struct mpls));
139 netisr_queue(NETISR_IPV6, m);
140 return;
141 }
142 goto again; /* If not the bottom label, per RFC4182. */
143
144 case 3:
145 /*
146 * Label 3: represents the "Implicit NULL Label" and must not
147 * appear on the wire.
148 */
149 break;
150 default:
151 /*
152 * Labels 4 - 15: reserved, drop them.
153 */
154 if (label <= 15) {
155 mplsstat.mplss_reserved++;
156 m_freem(m);
157 return;
158 }
159 if (mplsforwarding) {
160 mpls_forward(m);
161 return;
162 } else {
163 mplsstat.mplss_cantforward++;
164 m_freem(m);
165 return;
166 }
167 }
168
169 mplsstat.mplss_invalid++;
170 m_freem(m);
171 }
172
173 static void
mpls_forward(struct mbuf * m)174 mpls_forward(struct mbuf *m)
175 {
176 struct sockaddr_mpls *smpls;
177 struct mpls *mpls;
178 struct route *cache_rt = &mplsforward_rt[mycpuid];
179 mpls_label_t label;
180 struct ifnet *ifp;
181 struct sockaddr *dst;
182 int error;
183
184 KASSERT(m->m_len >= sizeof(struct mpls),
185 ("mpls_forward: mpls header not in one mbuf"));
186
187 mpls = mtod(m, struct mpls *);
188 label = MPLS_LABEL(ntohl(mpls->mpls_shim));
189
190 smpls = (struct sockaddr_mpls *) &cache_rt->ro_dst;
191 if (cache_rt->ro_rt == NULL || smpls->smpls_label != label) {
192 if (cache_rt->ro_rt != NULL) {
193 RTFREE(cache_rt->ro_rt);
194 cache_rt->ro_rt = NULL;
195 }
196 smpls->smpls_family = AF_MPLS;
197 smpls->smpls_len = sizeof(struct sockaddr_mpls);
198 smpls->smpls_label = htonl(label);
199 rtalloc(cache_rt);
200 if (cache_rt->ro_rt == NULL) {
201 /* route not found */
202 return;
203 }
204 }
205
206 ifp = cache_rt->ro_rt->rt_ifp;
207 dst = cache_rt->ro_rt->rt_gateway;
208 error = mpls_output(m, cache_rt->ro_rt);
209 if (error)
210 goto bad;
211 error = (*ifp->if_output)(ifp, m, dst, cache_rt->ro_rt);
212 if (error)
213 goto bad;
214 mplsstat.mplss_forwarded++;
215
216 return;
217 bad:
218 m_freem(m);
219 }
220