xref: /dragonfly/sys/netinet/in_gif.c (revision d4ef6694) 
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     {
80 	.pr_type = SOCK_RAW,
81 	.pr_domain = &inetdomain,
82 	.pr_protocol = 0 /*IPPROTO_IPV[46]*/,
83 	.pr_flags = PR_ATOMIC|PR_ADDR,
84 
85 	.pr_input = in_gif_input,
86 	.pr_output = rip_output,
87 	.pr_ctlinput = NULL,
88 	.pr_ctloutput = rip_ctloutput,
89 
90 	.pr_ctlport = NULL,
91 	.pr_usrreqs = &rip_usrreqs
92     };
93 
94 int ip_gif_ttl = GIF_TTL;
95 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
96 	&ip_gif_ttl, 0, "TTL of GIF packet");
97 
98 int
99 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
100 {
101 	struct gif_softc *sc = (struct gif_softc*)ifp;
102 	struct route *ro = &sc->gif_ro[mycpu->gd_cpuid];
103 	struct sockaddr_in *dst = (struct sockaddr_in *)&ro->ro_dst;
104 	struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
105 	struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
106 	struct ip iphdr;	/* capsule IP header, host byte ordered */
107 	int proto, error;
108 	u_int8_t tos;
109 
110 	if (sin_src == NULL || sin_dst == NULL ||
111 	    sin_src->sin_family != AF_INET ||
112 	    sin_dst->sin_family != AF_INET) {
113 		m_freem(m);
114 		return EAFNOSUPPORT;
115 	}
116 
117 	switch (family) {
118 #ifdef INET
119 	case AF_INET:
120 	    {
121 		struct ip *ip;
122 
123 		proto = IPPROTO_IPV4;
124 		if (m->m_len < sizeof *ip) {
125 			m = m_pullup(m, sizeof *ip);
126 			if (!m)
127 				return ENOBUFS;
128 		}
129 		ip = mtod(m, struct ip *);
130 		tos = ip->ip_tos;
131 		break;
132 	    }
133 #endif
134 #ifdef INET6
135 	case AF_INET6:
136 	    {
137 		struct ip6_hdr *ip6;
138 		proto = IPPROTO_IPV6;
139 		if (m->m_len < sizeof *ip6) {
140 			m = m_pullup(m, sizeof *ip6);
141 			if (!m)
142 				return ENOBUFS;
143 		}
144 		ip6 = mtod(m, struct ip6_hdr *);
145 		tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
146 		break;
147 	    }
148 #endif
149 	default:
150 #ifdef DEBUG
151 		kprintf("in_gif_output: warning: unknown family %d passed\n",
152 			family);
153 #endif
154 		m_freem(m);
155 		return EAFNOSUPPORT;
156 	}
157 
158 	bzero(&iphdr, sizeof iphdr);
159 	iphdr.ip_src = sin_src->sin_addr;
160 	/* bidirectional configured tunnel mode */
161 	if (sin_dst->sin_addr.s_addr != INADDR_ANY)
162 		iphdr.ip_dst = sin_dst->sin_addr;
163 	else {
164 		m_freem(m);
165 		return ENETUNREACH;
166 	}
167 	iphdr.ip_p = proto;
168 	/* version will be set in ip_output() */
169 	iphdr.ip_ttl = ip_gif_ttl;
170 	iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
171 	if (ifp->if_flags & IFF_LINK1)
172 		ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
173 	else
174 		ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
175 
176 	/* prepend new IP header */
177 	M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT);
178 	if (m && m->m_len < sizeof(struct ip))
179 		m = m_pullup(m, sizeof(struct ip));
180 	if (m == NULL) {
181 		kprintf("ENOBUFS in in_gif_output %d\n", __LINE__);
182 		return ENOBUFS;
183 	}
184 	bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
185 
186 	if (dst->sin_family != sin_dst->sin_family ||
187 	    dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
188 		/* cache route doesn't match */
189 		dst->sin_family = sin_dst->sin_family;
190 		dst->sin_len = sizeof(struct sockaddr_in);
191 		dst->sin_addr = sin_dst->sin_addr;
192 		if (ro->ro_rt != NULL) {
193 			RTFREE(ro->ro_rt);
194 			ro->ro_rt = NULL;
195 		}
196 #if 0
197 		sc->gif_if.if_mtu = GIF_MTU;
198 #endif
199 	}
200 
201 	if (ro->ro_rt == NULL) {
202 		rtalloc(ro);
203 		if (ro->ro_rt == NULL) {
204 			m_freem(m);
205 			return ENETUNREACH;
206 		}
207 
208 		/* if it constitutes infinite encapsulation, punt. */
209 		if (ro->ro_rt->rt_ifp == ifp) {
210 			m_freem(m);
211 			return ENETUNREACH;	/* XXX */
212 		}
213 #if 0
214 		ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu - sizeof(struct ip);
215 #endif
216 	}
217 
218 	error = ip_output(m, NULL, ro, 0, NULL, NULL);
219 	return(error);
220 }
221 
222 int
223 in_gif_input(struct mbuf **mp, int *offp, int proto)
224 {
225 	struct mbuf *m = *mp;
226 	struct ifnet *gifp = NULL;
227 	struct ip *ip;
228 	int af;
229 	u_int8_t otos;
230 	int off;
231 
232 	off = *offp;
233 	*mp = NULL;
234 
235 	ip = mtod(m, struct ip *);
236 
237 	gifp = (struct ifnet *)encap_getarg(m);
238 
239 	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
240 		m_freem(m);
241 		ipstat.ips_nogif++;
242 		return(IPPROTO_DONE);
243 	}
244 
245 	otos = ip->ip_tos;
246 	m_adj(m, off);
247 
248 	switch (proto) {
249 #ifdef INET
250 	case IPPROTO_IPV4:
251 	    {
252 		struct ip *ip;
253 		af = AF_INET;
254 		if (m->m_len < sizeof *ip) {
255 			m = m_pullup(m, sizeof *ip);
256 			if (!m)
257 				return(IPPROTO_DONE);
258 		}
259 		ip = mtod(m, struct ip *);
260 		if (gifp->if_flags & IFF_LINK1)
261 			ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
262 		else
263 			ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
264 		break;
265 	    }
266 #endif
267 #ifdef INET6
268 	case IPPROTO_IPV6:
269 	    {
270 		struct ip6_hdr *ip6;
271 		u_int8_t itos;
272 		af = AF_INET6;
273 		if (m->m_len < sizeof *ip6) {
274 			m = m_pullup(m, sizeof *ip6);
275 			if (!m)
276 				return(IPPROTO_DONE);
277 		}
278 		ip6 = mtod(m, struct ip6_hdr *);
279 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
280 		if (gifp->if_flags & IFF_LINK1)
281 			ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
282 		else
283 			ip_ecn_egress(ECN_NOCARE, &otos, &itos);
284 		ip6->ip6_flow &= ~htonl(0xff << 20);
285 		ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
286 		break;
287 	    }
288 #endif /* INET6 */
289 	default:
290 		ipstat.ips_nogif++;
291 		m_freem(m);
292 		return(IPPROTO_DONE);
293 	}
294 	gif_input(m, af, gifp);
295 	return(IPPROTO_DONE);
296 }
297 
298 /*
299  * validate outer address.
300  */
301 static int
302 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
303 {
304 	struct sockaddr_in *src, *dst;
305 	struct in_ifaddr_container *iac;
306 
307 	src = (struct sockaddr_in *)sc->gif_psrc;
308 	dst = (struct sockaddr_in *)sc->gif_pdst;
309 
310 	/* check for address match */
311 	if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
312 	    dst->sin_addr.s_addr != ip->ip_src.s_addr)
313 		return 0;
314 
315 	/* martian filters on outer source - NOT done in ip_input! */
316 	if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
317 		return 0;
318 	switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
319 	case 0: case 127: case 255:
320 		return 0;
321 	}
322 	/* reject packets with broadcast on source */
323 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
324 		struct in_ifaddr *ia4 = iac->ia;
325 
326 		if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST))
327 			continue;
328 		if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
329 			return 0;
330 	}
331 
332 	/* ingress filters on outer source */
333 	if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) {
334 		struct sockaddr_in sin;
335 		struct rtentry *rt;
336 
337 		bzero(&sin, sizeof sin);
338 		sin.sin_family = AF_INET;
339 		sin.sin_len = sizeof(struct sockaddr_in);
340 		sin.sin_addr = ip->ip_src;
341 		rt = rtpurelookup((struct sockaddr *)&sin);
342 		if (rt != NULL)
343 			--rt->rt_refcnt;
344 		if (rt == NULL || rt->rt_ifp != ifp) {
345 #if 0
346 			log(LOG_WARNING, "%s: packet from 0x%x dropped "
347 			    "due to ingress filter\n", if_name(&sc->gif_if),
348 			    (u_int32_t)ntohl(sin.sin_addr.s_addr));
349 #endif
350 			return 0;
351 		}
352 	}
353 
354 	return 32 * 2;
355 }
356 
357 /*
358  * we know that we are in IFF_UP, outer address available, and outer family
359  * matched the physical addr family.  see gif_encapcheck().
360  */
361 int
362 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
363 {
364 	struct ip ip;
365 	struct gif_softc *sc;
366 	struct ifnet *ifp;
367 
368 	/* sanity check done in caller */
369 	sc = (struct gif_softc *)arg;
370 
371 	/* LINTED const cast */
372 	m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip);
373 	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
374 
375 	return gif_validate4(&ip, sc, ifp);
376 }
377 
378 int
379 in_gif_attach(struct gif_softc *sc)
380 {
381 	sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
382 	    &in_gif_protosw, sc);
383 	if (sc->encap_cookie4 == NULL)
384 		return EEXIST;
385 	return 0;
386 }
387 
388 int
389 in_gif_detach(struct gif_softc *sc)
390 {
391 	int error;
392 
393 	error = encap_detach(sc->encap_cookie4);
394 	if (error == 0)
395 		sc->encap_cookie4 = NULL;
396 	return error;
397 }
398 
399 #endif /* INET */
400