xref: /freebsd/sys/netinet6/in6_gif.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
1 /*
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
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 the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 /*
33  * in6_gif.c
34  */
35 
36 #include "opt_inet.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/mbuf.h>
43 #include <sys/errno.h>
44 #include <sys/protosw.h>
45 
46 #include <net/if.h>
47 #include <net/route.h>
48 
49 #include <netinet/in.h>
50 #include <netinet/in_systm.h>
51 #ifdef INET
52 #include <netinet/ip.h>
53 #endif
54 #include <netinet6/ip6.h>
55 #include <netinet6/ip6_var.h>
56 #include <netinet6/in6_gif.h>
57 #include <netinet6/ip6.h>
58 
59 #include <net/if_gif.h>
60 
61 #include <net/net_osdep.h>
62 
63 int
64 in6_gif_output(ifp, family, m, rt)
65 	struct ifnet *ifp;
66 	int family; /* family of the packet to be encapsulate. */
67 	struct mbuf *m;
68 	struct rtentry *rt;
69 {
70 	struct gif_softc *sc = (struct gif_softc*)ifp;
71 	struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
72 	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
73 	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
74 	struct ip6_hdr *ip6;
75 	int proto;
76 
77 	if (sin6_src == NULL || sin6_dst == NULL ||
78 	    sin6_src->sin6_family != AF_INET6 ||
79 	    sin6_dst->sin6_family != AF_INET6) {
80 		m_freem(m);
81 		return EAFNOSUPPORT;
82 	}
83 
84 	switch (family) {
85 #ifdef INET
86 	case AF_INET:
87 	    {
88 		struct ip *ip;
89 
90 		proto = IPPROTO_IPV4;
91 		if (m->m_len < sizeof(*ip)) {
92 			m = m_pullup(m, sizeof(*ip));
93 			if (!m)
94 				return ENOBUFS;
95 		}
96 		ip = mtod(m, struct ip *);
97 		break;
98 	    }
99 #endif
100 	case AF_INET6:
101 	    {
102 		struct ip6_hdr *ip6;
103 		proto = IPPROTO_IPV6;
104 		if (m->m_len < sizeof(*ip6)) {
105 			m = m_pullup(m, sizeof(*ip6));
106 			if (!m)
107 				return ENOBUFS;
108 		}
109 		ip6 = mtod(m, struct ip6_hdr *);
110 		break;
111 	    }
112 	default:
113 #ifdef DIAGNOSTIC
114 		printf("in6_gif_output: warning: unknown family %d passed\n",
115 			family);
116 #endif
117 		m_freem(m);
118 		return EAFNOSUPPORT;
119 	}
120 
121 	/* prepend new IP header */
122 	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
123 	if (m && m->m_len < sizeof(struct ip6_hdr))
124 		m = m_pullup(m, sizeof(struct ip6_hdr));
125 	if (m == NULL) {
126 		printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
127 		return ENOBUFS;
128 	}
129 
130 	ip6 = mtod(m, struct ip6_hdr *);
131 	ip6->ip6_flow	= 0;
132 	ip6->ip6_vfc	= IPV6_VERSION;
133 	ip6->ip6_plen	= htons((u_short)m->m_pkthdr.len);
134 	ip6->ip6_nxt	= proto;
135 	ip6->ip6_hlim	= ip6_gif_hlim;
136 	ip6->ip6_src	= sin6_src->sin6_addr;
137 	if (ifp->if_flags & IFF_LINK0) {
138 		/* multi-destination mode */
139 		if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
140 			ip6->ip6_dst = sin6_dst->sin6_addr;
141 		else if (rt) {
142 			ip6->ip6_dst = ((struct sockaddr_in6 *)(rt->rt_gateway))->sin6_addr;
143 		} else {
144 			m_freem(m);
145 			return ENETUNREACH;
146 		}
147 	} else {
148 		/* bidirectional configured tunnel mode */
149 		if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
150 			ip6->ip6_dst = sin6_dst->sin6_addr;
151 		else  {
152 			m_freem(m);
153 			return ENETUNREACH;
154 		}
155 	}
156 
157 	if (dst->sin6_family != sin6_dst->sin6_family ||
158 	     !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
159 		/* cache route doesn't match */
160 		bzero(dst, sizeof(*dst));
161 		dst->sin6_family = sin6_dst->sin6_family;
162 		dst->sin6_len = sizeof(struct sockaddr_in6);
163 		dst->sin6_addr = sin6_dst->sin6_addr;
164 		if (sc->gif_ro6.ro_rt) {
165 			RTFREE(sc->gif_ro6.ro_rt);
166 			sc->gif_ro6.ro_rt = NULL;
167 		}
168 	}
169 
170 	if (sc->gif_ro6.ro_rt == NULL) {
171 		rtalloc((struct route *)&sc->gif_ro6);
172 		if (sc->gif_ro6.ro_rt == NULL) {
173 			m_freem(m);
174 			return ENETUNREACH;
175 		}
176 	}
177 
178 #ifdef IPSEC
179 	m->m_pkthdr.rcvif = NULL;
180 #endif /*IPSEC*/
181 	return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL));
182 }
183 
184 int in6_gif_input(mp, offp, proto)
185 	struct mbuf **mp;
186 	int *offp, proto;
187 {
188 	struct mbuf *m = *mp;
189 	struct gif_softc *sc;
190 	struct ifnet *gifp = NULL;
191 	struct ip6_hdr *ip6;
192 	int i;
193 	int af = 0;
194 
195 	ip6 = mtod(m, struct ip6_hdr *);
196 
197 #define	satoin6(sa)	(((struct sockaddr_in6 *)(sa))->sin6_addr)
198 	for (i = 0, sc = gif; i < ngif; i++, sc++) {
199 		if (sc->gif_psrc == NULL ||
200 		    sc->gif_pdst == NULL ||
201 		    sc->gif_psrc->sa_family != AF_INET6 ||
202 		    sc->gif_pdst->sa_family != AF_INET6) {
203 			continue;
204 		}
205 		if ((sc->gif_if.if_flags & IFF_UP) == 0)
206 			continue;
207 		if ((sc->gif_if.if_flags & IFF_LINK0) &&
208 		    IN6_ARE_ADDR_EQUAL(&satoin6(sc->gif_psrc), &ip6->ip6_dst) &&
209 		    IN6_IS_ADDR_UNSPECIFIED(&satoin6(sc->gif_pdst))) {
210 			gifp = &sc->gif_if;
211 			continue;
212 		}
213 		if (IN6_ARE_ADDR_EQUAL(&satoin6(sc->gif_psrc), &ip6->ip6_dst) &&
214 		    IN6_ARE_ADDR_EQUAL(&satoin6(sc->gif_pdst), &ip6->ip6_src)) {
215 			gifp = &sc->gif_if;
216 			break;
217 		}
218 	}
219 
220 	if (gifp == NULL) {
221 		m_freem(m);
222 		ip6stat.ip6s_nogif++;
223 		return IPPROTO_DONE;
224 	}
225 
226 	m_adj(m, *offp);
227 
228 	switch (proto) {
229 #ifdef INET
230 	case IPPROTO_IPV4:
231 	    {
232 		struct ip *ip;
233 		af = AF_INET;
234 		if (m->m_len < sizeof(*ip)) {
235 			m = m_pullup(m, sizeof(*ip));
236 			if (!m)
237 				return IPPROTO_DONE;
238 		}
239 		ip = mtod(m, struct ip *);
240 		break;
241 	    }
242 #endif /* INET */
243 	case IPPROTO_IPV6:
244 	    {
245 		struct ip6_hdr *ip6;
246 		af = AF_INET6;
247 		if (m->m_len < sizeof(*ip6)) {
248 			m = m_pullup(m, sizeof(*ip6));
249 			if (!m)
250 				return IPPROTO_DONE;
251 		}
252 		ip6 = mtod(m, struct ip6_hdr *);
253 		break;
254 	    }
255 	default:
256 		ip6stat.ip6s_nogif++;
257 		m_freem(m);
258 		return IPPROTO_DONE;
259 	}
260 
261 	gif_input(m, af, gifp);
262 	return IPPROTO_DONE;
263 }
264