1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009-2010 Ana Kukec <anchie@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/kernel.h>
31 #include <sys/malloc.h>
32 #include <sys/mbuf.h>
33 #include <sys/module.h>
34 #include <sys/priv.h>
35 #include <sys/protosw.h>
36 #include <sys/sdt.h>
37 #include <sys/systm.h>
38 #include <sys/socket.h>
39 #include <sys/sockbuf.h>
40 #include <sys/socketvar.h>
41 #include <sys/types.h>
42
43 #include <net/route.h>
44 #include <net/if.h>
45 #include <net/if_var.h>
46 #include <net/if_private.h>
47 #include <net/vnet.h>
48
49 #include <netinet/in.h>
50 #include <netinet/in_kdtrace.h>
51 #include <netinet/ip_var.h>
52 #include <netinet/ip6.h>
53 #include <netinet/icmp6.h>
54
55 #include <netinet6/in6_var.h>
56 #include <netinet6/nd6.h>
57 #include <netinet6/scope6_var.h>
58 #include <netinet6/send.h>
59
60 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery");
61
62 /*
63 * The socket used to communicate with the SeND daemon.
64 */
65 VNET_DEFINE_STATIC(struct socket *, send_so);
66 #define V_send_so VNET(send_so)
67
68 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send));
69 u_long send_recvspace = 9216;
70
71 struct mtx send_mtx;
72 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF)
73 #define SEND_LOCK() mtx_lock(&send_mtx)
74 #define SEND_UNLOCK() mtx_unlock(&send_mtx)
75 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx)
76
77 static int
send_attach(struct socket * so,int proto,struct thread * td)78 send_attach(struct socket *so, int proto, struct thread *td)
79 {
80 int error;
81
82 SEND_LOCK();
83 if (V_send_so != NULL) {
84 SEND_UNLOCK();
85 return (EEXIST);
86 }
87
88 error = priv_check(td, PRIV_NETINET_RAW);
89 if (error) {
90 SEND_UNLOCK();
91 return(error);
92 }
93
94 if (proto != IPPROTO_SEND) {
95 SEND_UNLOCK();
96 return (EPROTONOSUPPORT);
97 }
98 error = soreserve(so, send_sendspace, send_recvspace);
99 if (error) {
100 SEND_UNLOCK();
101 return(error);
102 }
103
104 V_send_so = so;
105 SEND_UNLOCK();
106
107 return (0);
108 }
109
110 static int
send_output(struct mbuf * m,struct ifnet * ifp,int direction)111 send_output(struct mbuf *m, struct ifnet *ifp, int direction)
112 {
113 struct ip6_hdr *ip6;
114 struct sockaddr_in6 dst;
115 struct icmp6_hdr *icmp6;
116 struct epoch_tracker et;
117 int icmp6len;
118 int error;
119
120 /*
121 * Receive incoming (SeND-protected) or outgoing traffic
122 * (SeND-validated) from the SeND user space application.
123 */
124
125 switch (direction) {
126 case SND_IN:
127 if (m->m_len < (sizeof(struct ip6_hdr) +
128 sizeof(struct icmp6_hdr))) {
129 m = m_pullup(m, sizeof(struct ip6_hdr) +
130 sizeof(struct icmp6_hdr));
131 if (!m)
132 return (ENOBUFS);
133 }
134
135 /* Before passing off the mbuf record the proper interface. */
136 m->m_pkthdr.rcvif = ifp;
137
138 if (m->m_flags & M_PKTHDR)
139 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr);
140 else
141 panic("Doh! not the first mbuf.");
142
143 ip6 = mtod(m, struct ip6_hdr *);
144 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
145 error = 0;
146
147 /*
148 * Output the packet as icmp6.c:icpm6_input() would do.
149 * The mbuf is always consumed, so we do not have to
150 * care about that.
151 */
152 NET_EPOCH_ENTER(et);
153 switch (icmp6->icmp6_type) {
154 case ND_NEIGHBOR_SOLICIT:
155 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len);
156 break;
157 case ND_NEIGHBOR_ADVERT:
158 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len);
159 break;
160 case ND_REDIRECT:
161 icmp6_redirect_input(m, sizeof(struct ip6_hdr));
162 break;
163 case ND_ROUTER_SOLICIT:
164 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len);
165 break;
166 case ND_ROUTER_ADVERT:
167 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len);
168 break;
169 default:
170 m_freem(m);
171 error = ENOSYS;
172 }
173 NET_EPOCH_EXIT(et);
174
175 return (error);
176
177 case SND_OUT:
178 if (m->m_len < sizeof(struct ip6_hdr)) {
179 m = m_pullup(m, sizeof(struct ip6_hdr));
180 if (!m)
181 return (ENOBUFS);
182 }
183 ip6 = mtod(m, struct ip6_hdr *);
184 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
185 m->m_flags |= M_MCAST;
186
187 bzero(&dst, sizeof(dst));
188 dst.sin6_family = AF_INET6;
189 dst.sin6_len = sizeof(dst);
190 dst.sin6_addr = ip6->ip6_dst;
191
192 m_clrprotoflags(m); /* Avoid confusing lower layers. */
193
194 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6);
195
196 /*
197 * Output the packet as nd6.c:nd6_output_lle() would do.
198 * The mbuf is always consumed, so we do not have to care
199 * about that.
200 * XXX-BZ as we added data, what about fragmenting,
201 * if now needed?
202 */
203 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst,
204 NULL));
205 if (error)
206 error = ENOENT;
207 return (error);
208
209 default:
210 panic("%s: direction %d neither SND_IN nor SND_OUT.",
211 __func__, direction);
212 }
213 }
214
215 /*
216 * Receive a SeND message from user space to be either send out by the kernel
217 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6
218 * input path.
219 */
220 static int
send_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * nam,struct mbuf * control,struct thread * td)221 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
222 struct mbuf *control, struct thread *td)
223 {
224 struct sockaddr_send *sendsrc;
225 struct ifnet *ifp;
226 int error;
227
228 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p",
229 __func__, so, V_send_so));
230
231 sendsrc = (struct sockaddr_send *)nam;
232 if (sendsrc->send_family != AF_INET6) {
233 error = EAFNOSUPPORT;
234 goto err;
235 }
236 if (sendsrc->send_len != sizeof(*sendsrc)) {
237 error = EINVAL;
238 goto err;
239 }
240 ifp = ifnet_byindex_ref(sendsrc->send_ifidx);
241 if (ifp == NULL) {
242 error = ENETUNREACH;
243 goto err;
244 }
245
246 error = send_output(m, ifp, sendsrc->send_direction);
247 if_rele(ifp);
248 m = NULL;
249
250 err:
251 if (control != NULL)
252 m_freem(control);
253 if (m != NULL)
254 m_freem(m);
255
256 return (error);
257 }
258
259 static void
send_close(struct socket * so)260 send_close(struct socket *so)
261 {
262
263 SEND_LOCK();
264 if (V_send_so)
265 V_send_so = NULL;
266 SEND_UNLOCK();
267 }
268
269 /*
270 * Send a SeND message to user space, that was either received and has to be
271 * validated or was about to be send out and has to be handled by the SEND
272 * daemon adding SeND ICMPv6 options.
273 */
274 static int
send_input(struct mbuf * m,struct ifnet * ifp,int direction,int msglen __unused)275 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused)
276 {
277 struct ip6_hdr *ip6;
278 struct sockaddr_send sendsrc;
279
280 SEND_LOCK();
281 if (V_send_so == NULL) {
282 SEND_UNLOCK();
283 return (-1);
284 }
285
286 /*
287 * Make sure to clear any possible internally embedded scope before
288 * passing the packet to user space for SeND cryptographic signature
289 * validation to succeed.
290 */
291 ip6 = mtod(m, struct ip6_hdr *);
292 in6_clearscope(&ip6->ip6_src);
293 in6_clearscope(&ip6->ip6_dst);
294
295 bzero(&sendsrc, sizeof(sendsrc));
296 sendsrc.send_len = sizeof(sendsrc);
297 sendsrc.send_family = AF_INET6;
298 sendsrc.send_direction = direction;
299 sendsrc.send_ifidx = ifp->if_index;
300
301 /*
302 * Send incoming or outgoing traffic to user space either to be
303 * protected (outgoing) or validated (incoming) according to rfc3971.
304 */
305 SOCKBUF_LOCK(&V_send_so->so_rcv);
306 if (sbappendaddr_locked(&V_send_so->so_rcv,
307 (struct sockaddr *)&sendsrc, m, NULL) == 0) {
308 soroverflow_locked(V_send_so);
309 /* XXX stats. */
310 m_freem(m);
311 } else {
312 sorwakeup_locked(V_send_so);
313 }
314
315 SEND_UNLOCK();
316 return (0);
317 }
318
319 static struct protosw send_protosw = {
320 .pr_type = SOCK_RAW,
321 .pr_flags = PR_ATOMIC|PR_ADDR,
322 .pr_protocol = IPPROTO_SEND,
323 .pr_attach = send_attach,
324 .pr_send = send_send,
325 .pr_detach = send_close
326 };
327
328 static int
send_modevent(module_t mod,int type,void * unused)329 send_modevent(module_t mod, int type, void *unused)
330 {
331 #ifdef __notyet__
332 VNET_ITERATOR_DECL(vnet_iter);
333 #endif
334 int error;
335
336 switch (type) {
337 case MOD_LOAD:
338 SEND_LOCK_INIT();
339
340 error = protosw_register(&inet6domain, &send_protosw);
341 if (error != 0) {
342 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n",
343 __func__, __LINE__, error);
344 SEND_LOCK_DESTROY();
345 break;
346 }
347 send_sendso_input_hook = send_input;
348 break;
349 case MOD_UNLOAD:
350 /* Do not allow unloading w/o locking. */
351 return (EBUSY);
352 #ifdef __notyet__
353 VNET_LIST_RLOCK_NOSLEEP();
354 SEND_LOCK();
355 VNET_FOREACH(vnet_iter) {
356 CURVNET_SET(vnet_iter);
357 if (V_send_so != NULL) {
358 CURVNET_RESTORE();
359 SEND_UNLOCK();
360 VNET_LIST_RUNLOCK_NOSLEEP();
361 return (EBUSY);
362 }
363 CURVNET_RESTORE();
364 }
365 SEND_UNLOCK();
366 VNET_LIST_RUNLOCK_NOSLEEP();
367 error = protosw_unregister(&send_protosw);
368 if (error == 0)
369 SEND_LOCK_DESTROY();
370 send_sendso_input_hook = NULL;
371 break;
372 #endif
373 default:
374 error = 0;
375 break;
376 }
377
378 return (error);
379 }
380
381 static moduledata_t sendmod = {
382 "send",
383 send_modevent,
384 0
385 };
386
387 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
388