1 /* $NetBSD: in_gif.c,v 1.96 2022/12/07 08:30:15 knakahara Exp $ */
2 /* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 itojun Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: in_gif.c,v 1.96 2022/12/07 08:30:15 knakahara Exp $");
35
36 #ifdef _KERNEL_OPT
37 #include "opt_inet.h"
38 #endif
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/mbuf.h>
45 #include <sys/errno.h>
46 #include <sys/ioctl.h>
47 #include <sys/syslog.h>
48 #include <sys/kernel.h>
49
50 #include <net/if.h>
51 #include <net/route.h>
52
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/in_gif.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip_encap.h>
60 #include <netinet/ip_ecn.h>
61
62 #ifdef INET6
63 #include <netinet/ip6.h>
64 #endif
65
66 #include <net/if_gif.h>
67
68 static int gif_validate4(const struct ip *, struct gif_variant *,
69 struct ifnet *);
70
71 int ip_gif_ttl = GIF_TTL;
72
73 static const struct encapsw in_gif_encapsw = {
74 .encapsw4 = {
75 .pr_input = in_gif_input,
76 .pr_ctlinput = NULL,
77 }
78 };
79
80 static int
in_gif_output(struct gif_variant * var,int family,struct mbuf * m)81 in_gif_output(struct gif_variant *var, int family, struct mbuf *m)
82 {
83 struct rtentry *rt;
84 struct gif_softc *sc;
85 struct sockaddr_in *sin_src;
86 struct sockaddr_in *sin_dst;
87 struct ifnet *ifp;
88 struct route *ro_pc;
89 kmutex_t *lock_pc;
90 struct ip iphdr; /* capsule IP header, host byte ordered */
91 int proto, error;
92 u_int8_t tos;
93
94 KASSERT(gif_heldref_variant(var));
95
96 sin_src = satosin(var->gv_psrc);
97 sin_dst = satosin(var->gv_pdst);
98 ifp = &var->gv_softc->gif_if;
99
100 if (sin_src == NULL || sin_dst == NULL ||
101 sin_src->sin_family != AF_INET ||
102 sin_dst->sin_family != AF_INET) {
103 m_freem(m);
104 return EAFNOSUPPORT;
105 }
106
107 switch (family) {
108 #ifdef INET
109 case AF_INET:
110 {
111 const struct ip *ip;
112
113 proto = IPPROTO_IPV4;
114 if (m->m_len < sizeof(*ip)) {
115 m = m_pullup(m, sizeof(*ip));
116 if (m == NULL)
117 return ENOBUFS;
118 }
119 ip = mtod(m, const struct ip *);
120 tos = ip->ip_tos;
121 break;
122 }
123 #endif /* INET */
124 #ifdef INET6
125 case AF_INET6:
126 {
127 const struct ip6_hdr *ip6;
128 proto = IPPROTO_IPV6;
129 if (m->m_len < sizeof(*ip6)) {
130 m = m_pullup(m, sizeof(*ip6));
131 if (m == NULL)
132 return ENOBUFS;
133 }
134 ip6 = mtod(m, const struct ip6_hdr *);
135 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
136 break;
137 }
138 #endif /* INET6 */
139 default:
140 #ifdef DEBUG
141 printf("in_gif_output: warning: unknown family %d passed\n",
142 family);
143 #endif
144 m_freem(m);
145 return EAFNOSUPPORT;
146 }
147
148 memset(&iphdr, 0, sizeof(iphdr));
149 iphdr.ip_src = sin_src->sin_addr;
150 /* bidirectional configured tunnel mode */
151 if (sin_dst->sin_addr.s_addr != INADDR_ANY)
152 iphdr.ip_dst = sin_dst->sin_addr;
153 else {
154 m_freem(m);
155 return ENETUNREACH;
156 }
157 iphdr.ip_p = proto;
158 /* version will be set in ip_output() */
159 iphdr.ip_ttl = ip_gif_ttl;
160 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip));
161 if (ifp->if_flags & IFF_LINK1)
162 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
163 else
164 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
165
166 /* prepend new IP header */
167 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
168 /* XXX Is m_pullup really necessary after M_PREPEND? */
169 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip)))
170 m = m_pullup(m, sizeof(struct ip));
171 if (m == NULL)
172 return ENOBUFS;
173 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
174
175 sc = var->gv_softc;
176 if_tunnel_get_ro(sc->gif_ro_percpu, &ro_pc, &lock_pc);
177 if ((rt = rtcache_lookup(ro_pc, var->gv_pdst)) == NULL) {
178 if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
179 m_freem(m);
180 return ENETUNREACH;
181 }
182
183 /* If the route constitutes infinite encapsulation, punt. */
184 if (rt->rt_ifp == ifp) {
185 rtcache_unref(rt, ro_pc);
186 rtcache_free(ro_pc);
187 if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
188 m_freem(m);
189 return ENETUNREACH; /*XXX*/
190 }
191 rtcache_unref(rt, ro_pc);
192
193 error = ip_output(m, NULL, ro_pc, 0, NULL, NULL);
194 if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
195 return (error);
196 }
197
198 void
in_gif_input(struct mbuf * m,int off,int proto,void * eparg)199 in_gif_input(struct mbuf *m, int off, int proto, void *eparg)
200 {
201 struct gif_softc *sc = eparg;
202 struct ifnet *gifp = &sc->gif_if;
203 const struct ip *ip;
204 int af;
205 u_int8_t otos;
206
207 KASSERT(sc != NULL);
208
209 ip = mtod(m, const struct ip *);
210
211 gifp = &sc->gif_if;
212 if ((gifp->if_flags & IFF_UP) == 0) {
213 m_freem(m);
214 ip_statinc(IP_STAT_NOGIF);
215 return;
216 }
217 #ifndef GIF_ENCAPCHECK
218 struct psref psref_var;
219 struct gif_variant *var = gif_getref_variant(sc, &psref_var);
220 /* other CPU do delete_tunnel */
221 if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
222 gif_putref_variant(var, &psref_var);
223 m_freem(m);
224 ip_statinc(IP_STAT_NOGIF);
225 return;
226 }
227
228 struct ifnet *rcvif;
229 struct psref psref_rcvif;
230 rcvif = m_get_rcvif_psref(m, &psref_rcvif);
231 if (!gif_validate4(ip, var, rcvif)) {
232 m_put_rcvif_psref(rcvif, &psref_rcvif);
233 gif_putref_variant(var, &psref_var);
234 m_freem(m);
235 ip_statinc(IP_STAT_NOGIF);
236 return;
237 }
238 m_put_rcvif_psref(rcvif, &psref_rcvif);
239 gif_putref_variant(var, &psref_var);
240 #endif
241 otos = ip->ip_tos;
242 m_adj(m, off);
243
244 switch (proto) {
245 #ifdef INET
246 case IPPROTO_IPV4:
247 {
248 struct ip *xip;
249 af = AF_INET;
250 if (M_UNWRITABLE(m, sizeof(*xip))) {
251 if ((m = m_pullup(m, sizeof(*xip))) == NULL)
252 return;
253 }
254 xip = mtod(m, struct ip *);
255 if (gifp->if_flags & IFF_LINK1)
256 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos);
257 else
258 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos);
259 break;
260 }
261 #endif
262 #ifdef INET6
263 case IPPROTO_IPV6:
264 {
265 struct ip6_hdr *ip6;
266 u_int8_t itos;
267 af = AF_INET6;
268 if (M_UNWRITABLE(m, sizeof(*ip6))) {
269 if ((m = m_pullup(m, sizeof(*ip6))) == NULL)
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 ip_statinc(IP_STAT_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
gif_validate4(const struct ip * ip,struct gif_variant * var,struct ifnet * ifp)296 gif_validate4(const struct ip *ip, struct gif_variant *var, struct ifnet *ifp)
297 {
298 struct sockaddr_in *src, *dst;
299 int ret;
300
301 src = satosin(var->gv_psrc);
302 dst = satosin(var->gv_pdst);
303
304 ret = in_tunnel_validate(ip, src->sin_addr, dst->sin_addr);
305 if (ret == 0)
306 return 0;
307
308 /* ingress filters on outer source */
309 if ((var->gv_softc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
310 union {
311 struct sockaddr sa;
312 struct sockaddr_in sin;
313 } u;
314 struct rtentry *rt;
315
316 sockaddr_in_init(&u.sin, &ip->ip_src, 0);
317 rt = rtalloc1(&u.sa, 0);
318 if (rt == NULL || rt->rt_ifp != ifp) {
319 #if 0
320 log(LOG_WARNING, "%s: packet from 0x%x dropped "
321 "due to ingress filter\n",
322 if_name(&var->gv_softc->gif_if),
323 (u_int32_t)ntohl(u.sin.sin_addr.s_addr));
324 #endif
325 if (rt != NULL)
326 rt_unref(rt);
327 return 0;
328 }
329 rt_unref(rt);
330 }
331
332 return ret;
333 }
334
335 #ifdef GIF_ENCAPCHECK
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(struct mbuf * m,int off,int proto,struct gif_variant * var)341 gif_encapcheck4(struct mbuf *m, int off, int proto, struct gif_variant *var)
342 {
343 struct ip ip;
344
345 struct ifnet *ifp = NULL;
346 int r;
347 struct psref psref;
348
349 m_copydata(m, 0, sizeof(ip), &ip);
350 if ((m->m_flags & M_PKTHDR) != 0)
351 ifp = m_get_rcvif_psref(m, &psref);
352
353 r = gif_validate4(&ip, var, ifp);
354
355 m_put_rcvif_psref(ifp, &psref);
356 return r;
357 }
358 #endif
359
360 int
in_gif_attach(struct gif_variant * var)361 in_gif_attach(struct gif_variant *var)
362 {
363 #ifndef GIF_ENCAPCHECK
364 struct sockaddr_in mask4;
365
366 memset(&mask4, 0, sizeof(mask4));
367 mask4.sin_len = sizeof(struct sockaddr_in);
368 mask4.sin_addr.s_addr = ~0;
369
370 if (!var->gv_psrc || !var->gv_pdst)
371 return EINVAL;
372
373 var->gv_encap_cookie4 = encap_attach_addr(AF_INET, -1, var->gv_psrc,
374 var->gv_pdst, NULL, &in_gif_encapsw, var->gv_softc);
375 #else
376 var->gv_encap_cookie4 = encap_attach_addr(AF_INET, -1, var->gv_psrc,
377 var->gv_pdst, gif_encapcheck, &in_gif_encapsw, var->gv_softc);
378 #endif
379 if (var->gv_encap_cookie4 == NULL)
380 return EEXIST;
381
382 var->gv_output = in_gif_output;
383 return 0;
384 }
385
386 int
in_gif_detach(struct gif_variant * var)387 in_gif_detach(struct gif_variant *var)
388 {
389 int error;
390 struct gif_softc *sc = var->gv_softc;
391
392 error = encap_detach(var->gv_encap_cookie4);
393 if (error == 0)
394 var->gv_encap_cookie4 = NULL;
395
396 if_tunnel_ro_percpu_rtcache_free(sc->gif_ro_percpu);
397
398 return error;
399 }
400