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 int ip_gif_ttl = GIF_TTL;
91 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW | CTLFLAG_LOCKED,
92 &ip_gif_ttl, 0, "");
93
94 int
in_gif_output(struct ifnet * ifp,int family,struct mbuf * m,__unused struct rtentry * rt)95 in_gif_output(
96 struct ifnet *ifp,
97 int family,
98 struct mbuf *m,
99 __unused struct rtentry *rt)
100 {
101 struct gif_softc *sc = ifnet_softc(ifp);
102 struct sockaddr_in *dst = (struct sockaddr_in *)
103 (void *)&sc->gif_ro.ro_dst;
104 struct sockaddr_in *sin_src = (struct sockaddr_in *)
105 (void *)sc->gif_psrc;
106 struct sockaddr_in *sin_dst = (struct sockaddr_in *)
107 (void *)sc->gif_pdst;
108 struct ip iphdr; /* capsule IP header, host byte ordered */
109 int proto, error;
110 u_int8_t tos;
111 struct ip_out_args ipoa;
112
113 bzero(&ipoa, sizeof(ipoa));
114 ipoa.ipoa_boundif = IFSCOPE_NONE;
115 ipoa.ipoa_flags = IPOAF_SELECT_SRCIF;
116 ipoa.ipoa_sotc = SO_TC_UNSPEC;
117 ipoa.ipoa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
118
119 GIF_LOCK_ASSERT(sc);
120
121 if (sin_src == NULL || sin_dst == NULL ||
122 sin_src->sin_family != AF_INET ||
123 sin_dst->sin_family != AF_INET) {
124 m_freem(m);
125 return EAFNOSUPPORT;
126 }
127
128 switch (family) {
129 #if INET
130 case AF_INET:
131 {
132 struct ip *ip;
133
134 proto = IPPROTO_IPV4;
135 if (mbuf_len(m) < sizeof(*ip)) {
136 m = m_pullup(m, sizeof(*ip));
137 if (!m) {
138 return ENOBUFS;
139 }
140 }
141 ip = mtod(m, struct ip *);
142 tos = ip->ip_tos;
143 break;
144 }
145 #endif /* INET */
146 case AF_INET6:
147 {
148 struct ip6_hdr *ip6;
149 proto = IPPROTO_IPV6;
150 if (mbuf_len(m) < sizeof(*ip6)) {
151 m = m_pullup(m, sizeof(*ip6));
152 if (!m) {
153 return ENOBUFS;
154 }
155 }
156 ip6 = mtod(m, struct ip6_hdr *);
157 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
158 break;
159 }
160 default:
161 #if DEBUG
162 printf("in_gif_output: warning: unknown family %d passed\n",
163 family);
164 #endif
165 m_freem(m);
166 return EAFNOSUPPORT;
167 }
168
169 bzero(&iphdr, sizeof(iphdr));
170 iphdr.ip_src = sin_src->sin_addr;
171 /* bidirectional configured tunnel mode */
172 if (sin_dst->sin_addr.s_addr != INADDR_ANY) {
173 iphdr.ip_dst = sin_dst->sin_addr;
174 } else {
175 m_freem(m);
176 return ENETUNREACH;
177 }
178 iphdr.ip_p = proto;
179 /* version will be set in ip_output() */
180 iphdr.ip_ttl = ip_gif_ttl;
181 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
182 if (ifp->if_flags & IFF_LINK1) {
183 ip_ecn_ingress(ECN_NORMAL, &iphdr.ip_tos, &tos);
184 } else {
185 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
186 }
187
188 /* prepend new IP header */
189 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 0);
190 if (m && mbuf_len(m) < sizeof(struct ip)) {
191 m = m_pullup(m, sizeof(struct ip));
192 }
193 if (m == NULL) {
194 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
195 return ENOBUFS;
196 }
197 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
198
199 if (ROUTE_UNUSABLE(&sc->gif_ro) ||
200 dst->sin_family != sin_dst->sin_family ||
201 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr ||
202 (sc->gif_ro.ro_rt != NULL && sc->gif_ro.ro_rt->rt_ifp == ifp)) {
203 /* cache route doesn't match or recursive route */
204 dst->sin_family = sin_dst->sin_family;
205 dst->sin_len = sizeof(struct sockaddr_in);
206 dst->sin_addr = sin_dst->sin_addr;
207 ROUTE_RELEASE(&sc->gif_ro);
208 #if 0
209 sc->gif_if.if_mtu = GIF_MTU;
210 #endif
211 }
212
213 if (sc->gif_ro.ro_rt == NULL) {
214 rtalloc(&sc->gif_ro);
215 if (sc->gif_ro.ro_rt == NULL) {
216 m_freem(m);
217 return ENETUNREACH;
218 }
219
220 /* if it constitutes infinite encapsulation, punt. */
221 RT_LOCK(sc->gif_ro.ro_rt);
222 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
223 RT_UNLOCK(sc->gif_ro.ro_rt);
224 m_freem(m);
225 return ENETUNREACH; /* XXX */
226 }
227 #if 0
228 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
229 - sizeof(struct ip);
230 #endif
231 RT_UNLOCK(sc->gif_ro.ro_rt);
232 }
233
234 error = ip_output(m, NULL, &sc->gif_ro, IP_OUTARGS, NULL, &ipoa);
235
236 return error;
237 }
238
239 void
in_gif_input(struct mbuf * m,int off)240 in_gif_input(struct mbuf *m, int off)
241 {
242 struct ifnet *gifp = NULL;
243 struct ip *ip;
244 int af, proto;
245 u_int8_t otos, old_tos;
246 int egress_success = 0;
247 int sum;
248
249 ip = mtod(m, struct ip *);
250 proto = ip->ip_p;
251
252
253 gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
254
255 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
256 m_freem(m);
257 OSAddAtomic(1, &ipstat.ips_nogif);
258 return;
259 }
260
261 otos = ip->ip_tos;
262 m_adj(m, off);
263
264 switch (proto) {
265 #if INET
266 case IPPROTO_IPV4:
267 {
268 af = AF_INET;
269 if (mbuf_len(m) < sizeof(*ip)) {
270 m = m_pullup(m, sizeof(*ip));
271 if (!m) {
272 return;
273 }
274 }
275 ip = mtod(m, struct ip *);
276 if (gifp->if_flags & IFF_LINK1) {
277 old_tos = ip->ip_tos;
278 egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &ip->ip_tos);
279 if (old_tos != ip->ip_tos) {
280 sum = ~ntohs(ip->ip_sum) & 0xffff;
281 sum += (~otos & 0xffff) + ip->ip_tos;
282 sum = (sum >> 16) + (sum & 0xffff);
283 sum += (sum >> 16); /* add carry */
284 ip->ip_sum = htons(~sum & 0xffff);
285 }
286 } else {
287 egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
288 }
289 break;
290 }
291 #endif
292 case IPPROTO_IPV6:
293 {
294 struct ip6_hdr *ip6;
295 u_int8_t itos;
296 af = AF_INET6;
297 if (mbuf_len(m) < sizeof(*ip6)) {
298 m = m_pullup(m, sizeof(*ip6));
299 if (!m) {
300 return;
301 }
302 }
303 ip6 = mtod(m, struct ip6_hdr *);
304 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
305 if (gifp->if_flags & IFF_LINK1) {
306 egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &itos);
307 } else {
308 egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &itos);
309 }
310 ip6->ip6_flow &= ~htonl(0xff << 20);
311 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
312 break;
313 }
314 default:
315 OSAddAtomic(1, &ipstat.ips_nogif);
316 m_freem(m);
317 return;
318 }
319
320 if (egress_success == 0) {
321 OSAddAtomic(1, &ipstat.ips_nogif);
322 m_freem(m);
323 return;
324 }
325
326 #ifdef __APPLE__
327 /* Replace the rcvif by gifp for dlil to route it correctly */
328 if (m->m_pkthdr.rcvif) {
329 m->m_pkthdr.rcvif = gifp;
330 }
331 ifnet_input(gifp, m, NULL);
332 #else
333 gif_input(m, af, gifp);
334 #endif
335 }
336
337 /*
338 * We know that we are in IFF_UP, outer address available, and outer family
339 * matched the physical addr family. see gif_encapcheck().
340 */
341 int
gif_encapcheck4(const struct mbuf * m,__unused int off,__unused int proto,void * arg)342 gif_encapcheck4(
343 const struct mbuf *m,
344 __unused int off,
345 __unused int proto,
346 void *arg)
347 {
348 struct ip ip;
349 struct gif_softc *sc;
350 struct sockaddr_in *src, *dst;
351 int addrmatch;
352 struct in_ifaddr *ia4;
353
354 /* sanity check done in caller */
355 sc = (struct gif_softc *)arg;
356 src = (struct sockaddr_in *)(void *)sc->gif_psrc;
357 dst = (struct sockaddr_in *)(void *)sc->gif_pdst;
358
359 GIF_LOCK_ASSERT(sc);
360
361 mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip), &ip);
362
363 /* check for address match */
364 addrmatch = 0;
365 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) {
366 addrmatch |= 1;
367 }
368 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) {
369 addrmatch |= 2;
370 }
371 if (addrmatch != 3) {
372 return 0;
373 }
374
375 /* martian filters on outer source - NOT done in ip_input! */
376 if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) {
377 return 0;
378 }
379 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
380 case 0: case 127: case 255:
381 return 0;
382 }
383 /* reject packets with broadcast on source */
384 lck_rw_lock_shared(&in_ifaddr_rwlock);
385 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
386 ia4 = TAILQ_NEXT(ia4, ia_link)) {
387 if ((ifnet_flags(ia4->ia_ifa.ifa_ifp) & IFF_BROADCAST) == 0) {
388 continue;
389 }
390 IFA_LOCK(&ia4->ia_ifa);
391 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
392 IFA_UNLOCK(&ia4->ia_ifa);
393 lck_rw_done(&in_ifaddr_rwlock);
394 return 0;
395 }
396 IFA_UNLOCK(&ia4->ia_ifa);
397 }
398 lck_rw_done(&in_ifaddr_rwlock);
399
400 /* ingress filters on outer source */
401 if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 &&
402 (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
403 struct sockaddr_in sin;
404 struct rtentry *rt;
405
406 bzero(&sin, sizeof(sin));
407 sin.sin_family = AF_INET;
408 sin.sin_len = sizeof(struct sockaddr_in);
409 sin.sin_addr = ip.ip_src;
410 rt = rtalloc1_scoped((struct sockaddr *)&sin, 0, 0,
411 m->m_pkthdr.rcvif->if_index);
412 if (rt != NULL) {
413 RT_LOCK(rt);
414 }
415 if (rt == NULL || rt->rt_ifp != m->m_pkthdr.rcvif) {
416 if (rt != NULL) {
417 RT_UNLOCK(rt);
418 rtfree(rt);
419 }
420 return 0;
421 }
422 RT_UNLOCK(rt);
423 rtfree(rt);
424 }
425
426 return 32 * 2;
427 }
428