1 /*
2 * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
29
30 /*
31 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
32 * All rights reserved.
33 *
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
36 * are met:
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
42 * 3. Neither the name of the project nor the names of its contributors
43 * may be used to endorse or promote products derived from this software
44 * without specific prior written permission.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56 * SUCH DAMAGE.
57 */
58
59
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/socket.h>
63 #include <sys/sockio.h>
64 #include <sys/mbuf.h>
65 #include <sys/errno.h>
66 #include <sys/kernel.h>
67 #include <sys/sysctl.h>
68
69 #include <sys/malloc.h>
70 #include <libkern/OSAtomic.h>
71
72 #include <net/if.h>
73 #include <net/route.h>
74
75 #include <netinet/in.h>
76 #include <netinet/in_systm.h>
77 #include <netinet/ip.h>
78 #include <netinet/ip_var.h>
79 #include <netinet/in_gif.h>
80 #include <netinet/in_var.h>
81 #include <netinet/ip_encap.h>
82 #include <netinet/ip_ecn.h>
83
84 #include <netinet/ip6.h>
85
86 #include <net/if_gif.h>
87
88 #include <net/net_osdep.h>
89
90 #include <net/sockaddr_utils.h>
91
92 int ip_gif_ttl = GIF_TTL;
93 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW | CTLFLAG_LOCKED,
94 &ip_gif_ttl, 0, "");
95
96 int
in_gif_output(struct ifnet * ifp,int family,struct mbuf * m,__unused struct rtentry * rt)97 in_gif_output(
98 struct ifnet *ifp,
99 int family,
100 struct mbuf *m,
101 __unused struct rtentry *rt)
102 {
103 struct gif_softc *__single sc = ifnet_softc(ifp);
104 struct sockaddr_in *__single dst = SIN(&sc->gif_ro.ro_dst);
105 struct sockaddr_in *__single sin_src = SIN(sc->gif_psrc);
106 struct sockaddr_in *__single sin_dst = SIN(sc->gif_pdst);
107 struct ip iphdr; /* capsule IP header, host byte ordered */
108 int proto, error;
109 u_int8_t tos;
110 struct ip_out_args ipoa;
111
112 bzero(&ipoa, sizeof(ipoa));
113 ipoa.ipoa_boundif = IFSCOPE_NONE;
114 ipoa.ipoa_flags = IPOAF_SELECT_SRCIF;
115 ipoa.ipoa_sotc = SO_TC_UNSPEC;
116 ipoa.ipoa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
117
118 GIF_LOCK_ASSERT(sc);
119
120 if (sin_src == NULL || sin_dst == NULL ||
121 sin_src->sin_family != AF_INET ||
122 sin_dst->sin_family != AF_INET) {
123 m_freem(m);
124 return EAFNOSUPPORT;
125 }
126
127 switch (family) {
128 #if INET
129 case AF_INET:
130 {
131 struct ip *__single ip;
132
133 proto = IPPROTO_IPV4;
134 if (mbuf_len(m) < sizeof(*ip)) {
135 m = m_pullup(m, sizeof(*ip));
136 if (!m) {
137 return ENOBUFS;
138 }
139 }
140 ip = mtod(m, struct ip *);
141 tos = ip->ip_tos;
142 break;
143 }
144 #endif /* INET */
145 case AF_INET6:
146 {
147 struct ip6_hdr *ip6;
148 proto = IPPROTO_IPV6;
149 if (mbuf_len(m) < sizeof(*ip6)) {
150 m = m_pullup(m, sizeof(*ip6));
151 if (!m) {
152 return ENOBUFS;
153 }
154 }
155 ip6 = mtod(m, struct ip6_hdr *);
156 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
157 break;
158 }
159 default:
160 #if DEBUG
161 printf("in_gif_output: warning: unknown family %d passed\n",
162 family);
163 #endif
164 m_freem(m);
165 return EAFNOSUPPORT;
166 }
167
168 bzero(&iphdr, sizeof(iphdr));
169 iphdr.ip_src = sin_src->sin_addr;
170 /* bidirectional configured tunnel mode */
171 if (sin_dst->sin_addr.s_addr != INADDR_ANY) {
172 iphdr.ip_dst = sin_dst->sin_addr;
173 } else {
174 m_freem(m);
175 return ENETUNREACH;
176 }
177 iphdr.ip_p = proto;
178 /* version will be set in ip_output() */
179 iphdr.ip_ttl = ip_gif_ttl;
180 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
181 if (ifp->if_flags & IFF_LINK1) {
182 ip_ecn_ingress(ECN_NORMAL, &iphdr.ip_tos, &tos);
183 } else {
184 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
185 }
186
187 /* prepend new IP header */
188 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 0);
189 if (m && mbuf_len(m) < sizeof(struct ip)) {
190 m = m_pullup(m, sizeof(struct ip));
191 }
192 if (m == NULL) {
193 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
194 return ENOBUFS;
195 }
196 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
197
198 if (ROUTE_UNUSABLE(&sc->gif_ro) ||
199 dst->sin_family != sin_dst->sin_family ||
200 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr ||
201 (sc->gif_ro.ro_rt != NULL && sc->gif_ro.ro_rt->rt_ifp == ifp)) {
202 /* cache route doesn't match or recursive route */
203 dst->sin_family = sin_dst->sin_family;
204 dst->sin_len = sizeof(struct sockaddr_in);
205 dst->sin_addr = sin_dst->sin_addr;
206 ROUTE_RELEASE(&sc->gif_ro);
207 #if 0
208 sc->gif_if.if_mtu = GIF_MTU;
209 #endif
210 }
211
212 if (sc->gif_ro.ro_rt == NULL) {
213 rtalloc(&sc->gif_ro);
214 if (sc->gif_ro.ro_rt == NULL) {
215 m_freem(m);
216 return ENETUNREACH;
217 }
218
219 /* if it constitutes infinite encapsulation, punt. */
220 RT_LOCK(sc->gif_ro.ro_rt);
221 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
222 RT_UNLOCK(sc->gif_ro.ro_rt);
223 m_freem(m);
224 return ENETUNREACH; /* XXX */
225 }
226 #if 0
227 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
228 - sizeof(struct ip);
229 #endif
230 RT_UNLOCK(sc->gif_ro.ro_rt);
231 }
232
233 error = ip_output(m, NULL, &sc->gif_ro, IP_OUTARGS, NULL, &ipoa);
234
235 return error;
236 }
237
238 void
in_gif_input(struct mbuf * m,int off)239 in_gif_input(struct mbuf *m, int off)
240 {
241 struct ifnet *gifp = NULL;
242 struct ip *ip;
243 int af, proto;
244 u_int8_t otos, old_tos;
245 int egress_success = 0;
246 int sum;
247
248 ip = mtod(m, struct ip *);
249 proto = ip->ip_p;
250
251
252 gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
253
254 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
255 m_freem(m);
256 OSAddAtomic(1, &ipstat.ips_nogif);
257 return;
258 }
259
260 otos = ip->ip_tos;
261 m_adj(m, off);
262
263 switch (proto) {
264 #if INET
265 case IPPROTO_IPV4:
266 {
267 af = AF_INET;
268 if (mbuf_len(m) < sizeof(*ip)) {
269 m = m_pullup(m, sizeof(*ip));
270 if (!m) {
271 return;
272 }
273 }
274 ip = mtod(m, struct ip *);
275 if (gifp->if_flags & IFF_LINK1) {
276 old_tos = ip->ip_tos;
277 egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &ip->ip_tos);
278 if (old_tos != ip->ip_tos) {
279 sum = ~ntohs(ip->ip_sum) & 0xffff;
280 sum += (~otos & 0xffff) + ip->ip_tos;
281 sum = (sum >> 16) + (sum & 0xffff);
282 sum += (sum >> 16); /* add carry */
283 ip->ip_sum = htons(~sum & 0xffff);
284 }
285 } else {
286 egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
287 }
288 break;
289 }
290 #endif
291 case IPPROTO_IPV6:
292 {
293 struct ip6_hdr *ip6;
294 u_int8_t itos;
295 af = AF_INET6;
296 if (mbuf_len(m) < sizeof(*ip6)) {
297 m = m_pullup(m, sizeof(*ip6));
298 if (!m) {
299 return;
300 }
301 }
302 ip6 = mtod(m, struct ip6_hdr *);
303 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
304 if (gifp->if_flags & IFF_LINK1) {
305 egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &itos);
306 } else {
307 egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &itos);
308 }
309 ip6->ip6_flow &= ~htonl(0xff << 20);
310 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
311 break;
312 }
313 default:
314 OSAddAtomic(1, &ipstat.ips_nogif);
315 m_freem(m);
316 return;
317 }
318
319 if (egress_success == 0) {
320 OSAddAtomic(1, &ipstat.ips_nogif);
321 m_freem(m);
322 return;
323 }
324
325 #ifdef __APPLE__
326 /* Replace the rcvif by gifp for dlil to route it correctly */
327 if (m->m_pkthdr.rcvif) {
328 m->m_pkthdr.rcvif = gifp;
329 }
330 ifnet_input(gifp, m, NULL);
331 #else
332 gif_input(m, af, gifp);
333 #endif
334 }
335
336 /*
337 * We know that we are in IFF_UP, outer address available, and outer family
338 * matched the physical addr family. see gif_encapcheck().
339 */
340 int
gif_encapcheck4(const struct mbuf * m,__unused int off,__unused int proto,void * arg)341 gif_encapcheck4(
342 const struct mbuf *m,
343 __unused int off,
344 __unused int proto,
345 void *arg)
346 {
347 struct ip ip;
348 struct gif_softc *__single sc;
349 struct sockaddr_in *__single src, *__single dst;
350 int addrmatch;
351 struct in_ifaddr *__single ia4;
352
353 /* sanity check done in caller */
354 sc = (struct gif_softc *)arg;
355 src = SIN(sc->gif_psrc);
356 dst = SIN(sc->gif_pdst);
357
358 GIF_LOCK_ASSERT(sc);
359
360 mbuf_copydata(__DECONST(struct mbuf *, m), 0, sizeof(ip), &ip);
361
362 /* check for address match */
363 addrmatch = 0;
364 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) {
365 addrmatch |= 1;
366 }
367 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) {
368 addrmatch |= 2;
369 }
370 if (addrmatch != 3) {
371 return 0;
372 }
373
374 /* martian filters on outer source - NOT done in ip_input! */
375 if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) {
376 return 0;
377 }
378 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
379 case 0: case 127: case 255:
380 return 0;
381 }
382 /* reject packets with broadcast on source */
383 lck_rw_lock_shared(&in_ifaddr_rwlock);
384 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
385 ia4 = TAILQ_NEXT(ia4, ia_link)) {
386 if ((ifnet_flags(ia4->ia_ifa.ifa_ifp) & IFF_BROADCAST) == 0) {
387 continue;
388 }
389 IFA_LOCK(&ia4->ia_ifa);
390 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
391 IFA_UNLOCK(&ia4->ia_ifa);
392 lck_rw_done(&in_ifaddr_rwlock);
393 return 0;
394 }
395 IFA_UNLOCK(&ia4->ia_ifa);
396 }
397 lck_rw_done(&in_ifaddr_rwlock);
398
399 /* ingress filters on outer source */
400 if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 &&
401 (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
402 struct sockaddr_in sin;
403 struct rtentry *rt;
404
405 SOCKADDR_ZERO(&sin, sizeof(sin));
406 sin.sin_family = AF_INET;
407 sin.sin_len = sizeof(struct sockaddr_in);
408 sin.sin_addr = ip.ip_src;
409 rt = rtalloc1_scoped(SA(&sin), 0, 0,
410 m->m_pkthdr.rcvif->if_index);
411 if (rt != NULL) {
412 RT_LOCK(rt);
413 }
414 if (rt == NULL || rt->rt_ifp != m->m_pkthdr.rcvif) {
415 if (rt != NULL) {
416 RT_UNLOCK(rt);
417 rtfree(rt);
418 }
419 return 0;
420 }
421 RT_UNLOCK(rt);
422 rtfree(rt);
423 }
424
425 return 32 * 2;
426 }
427