xref: /dragonfly/sys/netinet/in_gif.c (revision 99dd49c5) 
1 /*
2  * $FreeBSD: src/sys/netinet/in_gif.c,v 1.5.2.11 2003/01/23 21:06:45 sam Exp $
3  * $DragonFly: src/sys/netinet/in_gif.c,v 1.18 2008/10/27 02:56:30 sephe Exp $
4  * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $
5  */
6 /*
7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
8  * All rights reserved.
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  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "opt_inet.h"
36 #include "opt_inet6.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/kernel.h>
45 #include <sys/sysctl.h>
46 #include <sys/protosw.h>
47 
48 #include <sys/malloc.h>
49 
50 #include <machine/stdarg.h>
51 
52 #include <net/if.h>
53 #include <net/route.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/in_gif.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip_encap.h>
62 #include <netinet/ip_ecn.h>
63 
64 #ifdef INET6
65 #include <netinet/ip6.h>
66 #endif
67 
68 #include <net/gif/if_gif.h>
69 #include <net/net_osdep.h>
70 
71 #include <sys/thread2.h>	/* ipstat */
72 
73 #ifdef INET
74 static int gif_validate4 (const struct ip *, struct gif_softc *,
75 			  struct ifnet *);
76 
77 extern  struct domain inetdomain;
78 const struct protosw in_gif_protosw =
79 { SOCK_RAW,	&inetdomain,	0/*IPPROTO_IPV[46]*/,	PR_ATOMIC|PR_ADDR,
80   in_gif_input, rip_output,	0,	rip_ctloutput,
81   cpu0_soport,	NULL,
82   0,		0,		0,		0,
83   &rip_usrreqs
84 };
85 
86 int ip_gif_ttl = GIF_TTL;
87 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
88 	&ip_gif_ttl,	0, "");
89 
90 int
91 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
92 {
93 	struct gif_softc *sc = (struct gif_softc*)ifp;
94 	struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
95 	struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
96 	struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
97 	struct ip iphdr;	/* capsule IP header, host byte ordered */
98 	int proto, error;
99 	u_int8_t tos;
100 
101 	if (sin_src == NULL || sin_dst == NULL ||
102 	    sin_src->sin_family != AF_INET ||
103 	    sin_dst->sin_family != AF_INET) {
104 		m_freem(m);
105 		return EAFNOSUPPORT;
106 	}
107 
108 	switch (family) {
109 #ifdef INET
110 	case AF_INET:
111 	    {
112 		struct ip *ip;
113 
114 		proto = IPPROTO_IPV4;
115 		if (m->m_len < sizeof *ip) {
116 			m = m_pullup(m, sizeof *ip);
117 			if (!m)
118 				return ENOBUFS;
119 		}
120 		ip = mtod(m, struct ip *);
121 		tos = ip->ip_tos;
122 		break;
123 	    }
124 #endif
125 #ifdef INET6
126 	case AF_INET6:
127 	    {
128 		struct ip6_hdr *ip6;
129 		proto = IPPROTO_IPV6;
130 		if (m->m_len < sizeof *ip6) {
131 			m = m_pullup(m, sizeof *ip6);
132 			if (!m)
133 				return ENOBUFS;
134 		}
135 		ip6 = mtod(m, struct ip6_hdr *);
136 		tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
137 		break;
138 	    }
139 #endif
140 	default:
141 #ifdef DEBUG
142 		kprintf("in_gif_output: warning: unknown family %d passed\n",
143 			family);
144 #endif
145 		m_freem(m);
146 		return EAFNOSUPPORT;
147 	}
148 
149 	bzero(&iphdr, sizeof iphdr);
150 	iphdr.ip_src = sin_src->sin_addr;
151 	/* bidirectional configured tunnel mode */
152 	if (sin_dst->sin_addr.s_addr != INADDR_ANY)
153 		iphdr.ip_dst = sin_dst->sin_addr;
154 	else {
155 		m_freem(m);
156 		return ENETUNREACH;
157 	}
158 	iphdr.ip_p = proto;
159 	/* version will be set in ip_output() */
160 	iphdr.ip_ttl = ip_gif_ttl;
161 	iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
162 	if (ifp->if_flags & IFF_LINK1)
163 		ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
164 	else
165 		ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
166 
167 	/* prepend new IP header */
168 	M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT);
169 	if (m && m->m_len < sizeof(struct ip))
170 		m = m_pullup(m, sizeof(struct ip));
171 	if (m == NULL) {
172 		kprintf("ENOBUFS in in_gif_output %d\n", __LINE__);
173 		return ENOBUFS;
174 	}
175 	bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
176 
177 	if (dst->sin_family != sin_dst->sin_family ||
178 	    dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
179 		/* cache route doesn't match */
180 		dst->sin_family = sin_dst->sin_family;
181 		dst->sin_len = sizeof(struct sockaddr_in);
182 		dst->sin_addr = sin_dst->sin_addr;
183 		if (sc->gif_ro.ro_rt != NULL) {
184 			RTFREE(sc->gif_ro.ro_rt);
185 			sc->gif_ro.ro_rt = NULL;
186 		}
187 #if 0
188 		sc->gif_if.if_mtu = GIF_MTU;
189 #endif
190 	}
191 
192 	if (sc->gif_ro.ro_rt == NULL) {
193 		rtalloc(&sc->gif_ro);
194 		if (sc->gif_ro.ro_rt == NULL) {
195 			m_freem(m);
196 			return ENETUNREACH;
197 		}
198 
199 		/* if it constitutes infinite encapsulation, punt. */
200 		if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
201 			m_freem(m);
202 			return ENETUNREACH;	/* XXX */
203 		}
204 #if 0
205 		ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu -
206 		    sizeof(struct ip);
207 #endif
208 	}
209 
210 	error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
211 	return(error);
212 }
213 
214 void
215 in_gif_input(struct mbuf *m, ...)
216 {
217 	struct ifnet *gifp = NULL;
218 	struct ip *ip;
219 	int af;
220 	u_int8_t otos;
221 	int off, proto;
222 	__va_list ap;
223 
224 	__va_start(ap, m);
225 	off = __va_arg(ap, int);
226 	proto = __va_arg(ap, int);
227 	__va_end(ap);
228 
229 	ip = mtod(m, struct ip *);
230 
231 	gifp = (struct ifnet *)encap_getarg(m);
232 
233 	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
234 		m_freem(m);
235 		ipstat.ips_nogif++;
236 		return;
237 	}
238 
239 	otos = ip->ip_tos;
240 	m_adj(m, off);
241 
242 	switch (proto) {
243 #ifdef INET
244 	case IPPROTO_IPV4:
245 	    {
246 		struct ip *ip;
247 		af = AF_INET;
248 		if (m->m_len < sizeof *ip) {
249 			m = m_pullup(m, sizeof *ip);
250 			if (!m)
251 				return;
252 		}
253 		ip = mtod(m, struct ip *);
254 		if (gifp->if_flags & IFF_LINK1)
255 			ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
256 		else
257 			ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
258 		break;
259 	    }
260 #endif
261 #ifdef INET6
262 	case IPPROTO_IPV6:
263 	    {
264 		struct ip6_hdr *ip6;
265 		u_int8_t itos;
266 		af = AF_INET6;
267 		if (m->m_len < sizeof *ip6) {
268 			m = m_pullup(m, sizeof *ip6);
269 			if (!m)
270 				return;
271 		}
272 		ip6 = mtod(m, struct ip6_hdr *);
273 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
274 		if (gifp->if_flags & IFF_LINK1)
275 			ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
276 		else
277 			ip_ecn_egress(ECN_NOCARE, &otos, &itos);
278 		ip6->ip6_flow &= ~htonl(0xff << 20);
279 		ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
280 		break;
281 	    }
282 #endif /* INET6 */
283 	default:
284 		ipstat.ips_nogif++;
285 		m_freem(m);
286 		return;
287 	}
288 	gif_input(m, af, gifp);
289 	return;
290 }
291 
292 /*
293  * validate outer address.
294  */
295 static int
296 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
297 {
298 	struct sockaddr_in *src, *dst;
299 	struct in_ifaddr_container *iac;
300 
301 	src = (struct sockaddr_in *)sc->gif_psrc;
302 	dst = (struct sockaddr_in *)sc->gif_pdst;
303 
304 	/* check for address match */
305 	if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
306 	    dst->sin_addr.s_addr != ip->ip_src.s_addr)
307 		return 0;
308 
309 	/* martian filters on outer source - NOT done in ip_input! */
310 	if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
311 		return 0;
312 	switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
313 	case 0: case 127: case 255:
314 		return 0;
315 	}
316 	/* reject packets with broadcast on source */
317 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
318 		struct in_ifaddr *ia4 = iac->ia;
319 
320 		if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST))
321 			continue;
322 		if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
323 			return 0;
324 	}
325 
326 	/* ingress filters on outer source */
327 	if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) {
328 		struct sockaddr_in sin;
329 		struct rtentry *rt;
330 
331 		bzero(&sin, sizeof sin);
332 		sin.sin_family = AF_INET;
333 		sin.sin_len = sizeof(struct sockaddr_in);
334 		sin.sin_addr = ip->ip_src;
335 		rt = rtpurelookup((struct sockaddr *)&sin);
336 		if (rt != NULL)
337 			--rt->rt_refcnt;
338 		if (rt == NULL || rt->rt_ifp != ifp) {
339 #if 0
340 			log(LOG_WARNING, "%s: packet from 0x%x dropped "
341 			    "due to ingress filter\n", if_name(&sc->gif_if),
342 			    (u_int32_t)ntohl(sin.sin_addr.s_addr));
343 #endif
344 			return 0;
345 		}
346 	}
347 
348 	return 32 * 2;
349 }
350 
351 /*
352  * we know that we are in IFF_UP, outer address available, and outer family
353  * matched the physical addr family.  see gif_encapcheck().
354  */
355 int
356 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
357 {
358 	struct ip ip;
359 	struct gif_softc *sc;
360 	struct ifnet *ifp;
361 
362 	/* sanity check done in caller */
363 	sc = (struct gif_softc *)arg;
364 
365 	/* LINTED const cast */
366 	m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip);
367 	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
368 
369 	return gif_validate4(&ip, sc, ifp);
370 }
371 
372 int
373 in_gif_attach(struct gif_softc *sc)
374 {
375 	sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
376 	    &in_gif_protosw, sc);
377 	if (sc->encap_cookie4 == NULL)
378 		return EEXIST;
379 	return 0;
380 }
381 
382 int
383 in_gif_detach(struct gif_softc *sc)
384 {
385 	int error;
386 
387 	error = encap_detach(sc->encap_cookie4);
388 	if (error == 0)
389 		sc->encap_cookie4 = NULL;
390 	return error;
391 }
392 
393 #endif /* INET */
394