FreeBSD/Linux Kernel Cross Reference
sys/netinet6/send.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/mbuf.h>
36 #include <sys/module.h>
37 #include <sys/priv.h>
38 #include <sys/protosw.h>
39 #include <sys/sdt.h>
40 #include <sys/systm.h>
41 #include <sys/socket.h>
42 #include <sys/sockbuf.h>
43 #include <sys/socketvar.h>
44 #include <sys/types.h>
45
46 #include <net/route.h>
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/vnet.h>
50
51 #include <netinet/in.h>
52 #include <netinet/in_kdtrace.h>
53 #include <netinet/ip_var.h>
54 #include <netinet/ip6.h>
55 #include <netinet/icmp6.h>
56
57 #include <netinet6/in6_var.h>
58 #include <netinet6/nd6.h>
59 #include <netinet6/scope6_var.h>
60 #include <netinet6/send.h>
61
62 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery");
63
64 /*
65 * The socket used to communicate with the SeND daemon.
66 */
67 VNET_DEFINE_STATIC(struct socket *, send_so);
68 #define V_send_so VNET(send_so)
69
70 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send));
71 u_long send_recvspace = 9216;
72
73 struct mtx send_mtx;
74 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF)
75 #define SEND_LOCK() mtx_lock(&send_mtx)
76 #define SEND_UNLOCK() mtx_unlock(&send_mtx)
77 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx)
78
79 static int
80 send_attach(struct socket *so, int proto, struct thread *td)
81 {
82 int error;
83
84 SEND_LOCK();
85 if (V_send_so != NULL) {
86 SEND_UNLOCK();
87 return (EEXIST);
88 }
89
90 error = priv_check(td, PRIV_NETINET_RAW);
91 if (error) {
92 SEND_UNLOCK();
93 return(error);
94 }
95
96 if (proto != IPPROTO_SEND) {
97 SEND_UNLOCK();
98 return (EPROTONOSUPPORT);
99 }
100 error = soreserve(so, send_sendspace, send_recvspace);
101 if (error) {
102 SEND_UNLOCK();
103 return(error);
104 }
105
106 V_send_so = so;
107 SEND_UNLOCK();
108
109 return (0);
110 }
111
112 static int
113 send_output(struct mbuf *m, struct ifnet *ifp, int direction)
114 {
115 struct ip6_hdr *ip6;
116 struct sockaddr_in6 dst;
117 struct icmp6_hdr *icmp6;
118 int icmp6len;
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
146 /*
147 * Output the packet as icmp6.c:icpm6_input() would do.
148 * The mbuf is always consumed, so we do not have to
149 * care about that.
150 */
151 switch (icmp6->icmp6_type) {
152 case ND_NEIGHBOR_SOLICIT:
153 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len);
154 break;
155 case ND_NEIGHBOR_ADVERT:
156 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len);
157 break;
158 case ND_REDIRECT:
159 icmp6_redirect_input(m, sizeof(struct ip6_hdr));
160 break;
161 case ND_ROUTER_SOLICIT:
162 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len);
163 break;
164 case ND_ROUTER_ADVERT:
165 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len);
166 break;
167 default:
168 m_freem(m);
169 return (ENOSYS);
170 }
171 return (0);
172
173 case SND_OUT:
174 if (m->m_len < sizeof(struct ip6_hdr)) {
175 m = m_pullup(m, sizeof(struct ip6_hdr));
176 if (!m)
177 return (ENOBUFS);
178 }
179 ip6 = mtod(m, struct ip6_hdr *);
180 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
181 m->m_flags |= M_MCAST;
182
183 bzero(&dst, sizeof(dst));
184 dst.sin6_family = AF_INET6;
185 dst.sin6_len = sizeof(dst);
186 dst.sin6_addr = ip6->ip6_dst;
187
188 m_clrprotoflags(m); /* Avoid confusing lower layers. */
189
190 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6);
191
192 /*
193 * Output the packet as nd6.c:nd6_output_lle() would do.
194 * The mbuf is always consumed, so we do not have to care
195 * about that.
196 * XXX-BZ as we added data, what about fragmenting,
197 * if now needed?
198 */
199 int error;
200 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst,
201 NULL));
202 if (error)
203 error = ENOENT;
204 return (error);
205
206 default:
207 panic("%s: direction %d neither SND_IN nor SND_OUT.",
208 __func__, direction);
209 }
210 }
211
212 /*
213 * Receive a SeND message from user space to be either send out by the kernel
214 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6
215 * input path.
216 */
217 static int
218 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
219 struct mbuf *control, struct thread *td)
220 {
221 struct sockaddr_send *sendsrc;
222 struct ifnet *ifp;
223 int error;
224
225 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p",
226 __func__, so, V_send_so));
227
228 sendsrc = (struct sockaddr_send *)nam;
229 ifp = ifnet_byindex_ref(sendsrc->send_ifidx);
230 if (ifp == NULL) {
231 error = ENETUNREACH;
232 goto err;
233 }
234
235 error = send_output(m, ifp, sendsrc->send_direction);
236 if_rele(ifp);
237 m = NULL;
238
239 err:
240 if (m != NULL)
241 m_freem(m);
242 return (error);
243 }
244
245 static void
246 send_close(struct socket *so)
247 {
248
249 SEND_LOCK();
250 if (V_send_so)
251 V_send_so = NULL;
252 SEND_UNLOCK();
253 }
254
255 /*
256 * Send a SeND message to user space, that was either received and has to be
257 * validated or was about to be send out and has to be handled by the SEND
258 * daemon adding SeND ICMPv6 options.
259 */
260 static int
261 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused)
262 {
263 struct ip6_hdr *ip6;
264 struct sockaddr_send sendsrc;
265
266 SEND_LOCK();
267 if (V_send_so == NULL) {
268 SEND_UNLOCK();
269 return (-1);
270 }
271
272 /*
273 * Make sure to clear any possible internally embedded scope before
274 * passing the packet to user space for SeND cryptographic signature
275 * validation to succeed.
276 */
277 ip6 = mtod(m, struct ip6_hdr *);
278 in6_clearscope(&ip6->ip6_src);
279 in6_clearscope(&ip6->ip6_dst);
280
281 bzero(&sendsrc, sizeof(sendsrc));
282 sendsrc.send_len = sizeof(sendsrc);
283 sendsrc.send_family = AF_INET6;
284 sendsrc.send_direction = direction;
285 sendsrc.send_ifidx = ifp->if_index;
286
287 /*
288 * Send incoming or outgoing traffic to user space either to be
289 * protected (outgoing) or validated (incoming) according to rfc3971.
290 */
291 SOCKBUF_LOCK(&V_send_so->so_rcv);
292 if (sbappendaddr_locked(&V_send_so->so_rcv,
293 (struct sockaddr *)&sendsrc, m, NULL) == 0) {
294 soroverflow_locked(V_send_so);
295 /* XXX stats. */
296 m_freem(m);
297 } else {
298 sorwakeup_locked(V_send_so);
299 }
300
301 SEND_UNLOCK();
302 return (0);
303 }
304
305 struct pr_usrreqs send_usrreqs = {
306 .pru_attach = send_attach,
307 .pru_send = send_send,
308 .pru_detach = send_close
309 };
310 struct protosw send_protosw = {
311 .pr_type = SOCK_RAW,
312 .pr_flags = PR_ATOMIC|PR_ADDR,
313 .pr_protocol = IPPROTO_SEND,
314 .pr_usrreqs = &send_usrreqs
315 };
316
317 static int
318 send_modevent(module_t mod, int type, void *unused)
319 {
320 #ifdef __notyet__
321 VNET_ITERATOR_DECL(vnet_iter);
322 #endif
323 int error;
324
325 switch (type) {
326 case MOD_LOAD:
327 SEND_LOCK_INIT();
328
329 error = pf_proto_register(PF_INET6, &send_protosw);
330 if (error != 0) {
331 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n",
332 __func__, __LINE__, error);
333 SEND_LOCK_DESTROY();
334 break;
335 }
336 send_sendso_input_hook = send_input;
337 break;
338 case MOD_UNLOAD:
339 /* Do not allow unloading w/o locking. */
340 return (EBUSY);
341 #ifdef __notyet__
342 VNET_LIST_RLOCK_NOSLEEP();
343 SEND_LOCK();
344 VNET_FOREACH(vnet_iter) {
345 CURVNET_SET(vnet_iter);
346 if (V_send_so != NULL) {
347 CURVNET_RESTORE();
348 SEND_UNLOCK();
349 VNET_LIST_RUNLOCK_NOSLEEP();
350 return (EBUSY);
351 }
352 CURVNET_RESTORE();
353 }
354 SEND_UNLOCK();
355 VNET_LIST_RUNLOCK_NOSLEEP();
356 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW);
357 if (error == 0)
358 SEND_LOCK_DESTROY();
359 send_sendso_input_hook = NULL;
360 break;
361 #endif
362 default:
363 error = 0;
364 break;
365 }
366
367 return (error);
368 }
369
370 static moduledata_t sendmod = {
371 "send",
372 send_modevent,
373 0
374 };
375
376 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
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