1 /* $NetBSD: ip6_etherip.c,v 1.18 2016/06/10 13:27:16 ozaki-r Exp $ */
2
3 /*
4 * Copyright (c) 2006, Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Hans Rosenfeld nor the names of his
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *
32 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 * 3. Neither the name of the project nor the names of its contributors
44 * may be used to endorse or promote products derived from this software
45 * without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57 * SUCH DAMAGE.
58 */
59
60 #include <sys/cdefs.h>
61 __KERNEL_RCSID(0, "$NetBSD: ip6_etherip.c,v 1.18 2016/06/10 13:27:16 ozaki-r Exp $");
62
63 #ifdef _KERNEL_OPT
64 #include "opt_inet.h"
65 #endif
66
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/socket.h>
70 #include <sys/sockio.h>
71 #include <sys/mbuf.h>
72 #include <sys/device.h>
73 #include <sys/errno.h>
74 #include <sys/ioctl.h>
75 #include <sys/syslog.h>
76 #include <sys/protosw.h>
77 #include <sys/kernel.h>
78
79 #include <net/if.h>
80 #include <net/route.h>
81
82 #include <netinet/in.h>
83 #include <netinet/in_systm.h>
84 #ifdef INET
85 #include <netinet/ip.h>
86 #endif
87 #ifdef INET6
88 #include <netinet/ip6.h>
89 #include <netinet6/ip6_var.h>
90 #include <netinet6/ip6_private.h>
91 #include <netinet6/in6_var.h>
92 #include <netinet6/ip6_etherip.h>
93 #endif
94
95 #include <net/if_ether.h>
96 #include <net/if_media.h>
97 #include <net/if_etherip.h>
98 #include <net/bpf.h>
99
100 int
ip6_etherip_output(struct ifnet * ifp,struct mbuf * m)101 ip6_etherip_output(struct ifnet *ifp, struct mbuf *m)
102 {
103 struct rtentry *rt;
104 struct etherip_softc *sc = (struct etherip_softc *)ifp->if_softc;
105 struct sockaddr_in6 *sin6_src, *sin6_dst;
106 struct ip6_hdr *ip6; /* capsule IP header, host byte ordered */
107 struct etherip_header eiphdr;
108 int proto, error;
109 union {
110 struct sockaddr dst;
111 struct sockaddr_in6 dst6;
112 } u;
113
114 sin6_src = (struct sockaddr_in6 *)sc->sc_src;
115 sin6_dst = (struct sockaddr_in6 *)sc->sc_dst;
116
117 if (sin6_src == NULL ||
118 sin6_dst == NULL ||
119 sin6_src->sin6_family != AF_INET6 ||
120 sin6_dst->sin6_family != AF_INET6) {
121 m_freem(m);
122 return EAFNOSUPPORT;
123 }
124
125 /* reset broadcast/multicast flags */
126 m->m_flags &= ~(M_BCAST|M_MCAST);
127
128 m->m_flags |= M_PKTHDR;
129 proto = IPPROTO_ETHERIP;
130
131 /* fill and prepend Ethernet-in-IP header */
132 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
133 eiphdr.eip_pad = 0;
134 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
135 if (m == NULL)
136 return ENOBUFS;
137 if (M_UNWRITABLE(m, sizeof(struct etherip_header))) {
138 m = m_pullup(m, sizeof(struct etherip_header));
139 if (m == NULL)
140 return ENOBUFS;
141 }
142 memcpy(mtod(m, struct etherip_header *), &eiphdr,
143 sizeof(struct etherip_header));
144
145 /* prepend new IP header */
146 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
147 if (m && m->m_len < sizeof(struct ip6_hdr))
148 m = m_pullup(m, sizeof(struct ip6_hdr));
149 if (m == NULL)
150 return ENOBUFS;
151
152 ip6 = mtod(m, struct ip6_hdr *);
153 ip6->ip6_flow = 0;
154 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
155 ip6->ip6_vfc |= IPV6_VERSION;
156 ip6->ip6_nxt = proto;
157 ip6->ip6_hlim = ETHERIP_TTL;
158 ip6->ip6_src = sin6_src->sin6_addr;
159
160 /* bidirectional configured tunnel mode */
161 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
162 ip6->ip6_dst = sin6_dst->sin6_addr;
163 else {
164 m_freem(m);
165 return ENETUNREACH;
166 }
167
168 sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0);
169 if ((rt = rtcache_lookup(&sc->sc_ro, &u.dst)) == NULL) {
170 m_freem(m);
171 return ENETUNREACH;
172 }
173 /* if it constitutes infinite encapsulation, punt. */
174 if (rt->rt_ifp == ifp) {
175 rtcache_free(&sc->sc_ro);
176 m_freem(m);
177 return ENETUNREACH; /* XXX */
178 }
179
180 /*
181 * force fragmentation to minimum MTU, to avoid path MTU discovery.
182 * it is too painful to ask for resend of inner packet, to achieve
183 * path MTU discovery for encapsulated packets.
184 */
185 error = ip6_output(m, 0, &sc->sc_ro, IPV6_MINMTU, NULL, NULL, NULL);
186
187 return error;
188 }
189
190 int
ip6_etherip_input(struct mbuf ** mp,int * offp,int proto)191 ip6_etherip_input(struct mbuf **mp, int *offp, int proto)
192 {
193 struct mbuf *m = *mp;
194 int off = *offp;
195 struct etherip_softc *sc;
196 const struct ip6_hdr *ip6;
197 struct sockaddr_in6 *src6, *dst6;
198 struct ifnet *ifp = NULL;
199 int s;
200
201 if (proto != IPPROTO_ETHERIP) {
202 m_freem(m);
203 IP6_STATINC(IP6_STAT_NOGIF);
204 return IPPROTO_DONE;
205 }
206
207 ip6 = mtod(m, const struct ip6_hdr *);
208
209 /* find device configured for this packets src and dst */
210 LIST_FOREACH(sc, ðerip_softc_list, etherip_list) {
211 if( !sc->sc_src || !sc->sc_dst)
212 continue;
213 if (sc->sc_src->sa_family != AF_INET6 ||
214 sc->sc_dst->sa_family != AF_INET6)
215 continue;
216
217 src6 = (struct sockaddr_in6 *)sc->sc_src;
218 dst6 = (struct sockaddr_in6 *)sc->sc_dst;
219
220 if (!IN6_ARE_ADDR_EQUAL(&src6->sin6_addr, &ip6->ip6_dst) ||
221 !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_src))
222 continue;
223
224 ifp = &sc->sc_ec.ec_if;
225 break;
226 }
227
228 /* no matching device found */
229 if (!ifp) {
230 m_freem(m);
231 IP6_STATINC(IP6_STAT_ODROPPED);
232 return IPPROTO_DONE;
233 }
234
235 m_adj(m, off);
236
237 /*
238 * Section 4 of RFC 3378 requires that the EtherIP header of incoming
239 * packets is verified to contain the correct values in the version and
240 * reserved fields, and packets with wrong values be dropped.
241 *
242 * There is some discussion about what exactly the header should look
243 * like, the RFC is not very clear there. To be compatible with broken
244 * implementations, we don't check the header on incoming packets,
245 * relying on the ethernet code to filter out garbage.
246 *
247 * The header we use for sending is compatible with the original
248 * implementation in OpenBSD, which was used in former NetBSD versions
249 * and is used in FreeBSD. One Linux implementation is known to use the
250 * same value.
251 */
252 m_adj(m, sizeof(struct etherip_header));
253 m = m_pullup(m, sizeof(struct ether_header));
254 if (m == NULL) {
255 ifp->if_ierrors++;
256 return IPPROTO_DONE;
257 }
258
259 m_set_rcvif(m, ifp);
260 m->m_flags &= ~(M_BCAST|M_MCAST);
261
262 bpf_mtap(ifp, m);
263
264 ifp->if_ipackets++;
265
266 s = splnet();
267 if_input(ifp, m);
268 splx(s);
269
270 return IPPROTO_DONE;
271 }
272