xref: /netbsd-src/sys/netipsec/ipsec_netbsd.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: ipsec_netbsd.c,v 1.5 2004/01/23 02:39:49 jonathan Exp $	*/
2 /*	$KAME: esp_input.c,v 1.60 2001/09/04 08:43:19 itojun Exp $	*/
3 /*	$KAME: ah_input.c,v 1.64 2001/09/04 08:43:19 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: ipsec_netbsd.c,v 1.5 2004/01/23 02:39:49 jonathan Exp $");
36 
37 #include "opt_inet.h"
38 #include "opt_ipsec.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/domain.h>
45 #include <sys/protosw.h>
46 #include <sys/socket.h>
47 #include <sys/errno.h>
48 #include <sys/time.h>
49 #include <sys/kernel.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/route.h>
54 #include <net/netisr.h>
55 #include <machine/cpu.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/in_systm.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/ip_ecn.h>
63 #include <netinet/ip_icmp.h>
64 
65 
66 #include <netipsec/ipsec.h>
67 #include <netipsec/key.h>
68 #include <netipsec/keydb.h>
69 #include <netipsec/key_debug.h>
70 #include <netipsec/ah_var.h>
71 #include <netipsec/esp.h>
72 
73 #ifdef INET6
74 #include <netipsec/ipsec6.h>
75 #include <netinet6/ip6protosw.h>
76 #include <netinet/icmp6.h>
77 #endif
78 
79 #include <machine/stdarg.h>
80 
81 
82 
83 #include <netipsec/key.h>
84 
85 /* assumes that ip header and ah header are contiguous on mbuf */
86 void *
87 ah4_ctlinput(cmd, sa, v)
88 	int cmd;
89 	struct sockaddr *sa;
90 	void *v;
91 {
92 	struct ip *ip = v;
93 	struct ah *ah;
94 	struct icmp *icp;
95 	struct secasvar *sav;
96 
97 	if (sa->sa_family != AF_INET ||
98 	    sa->sa_len != sizeof(struct sockaddr_in))
99 		return NULL;
100 	if ((unsigned)cmd >= PRC_NCMDS)
101 		return NULL;
102 #ifndef notyet
103 	(void) ip; (void) ah; (void) icp; (void) sav;
104 #else
105 	if (cmd == PRC_MSGSIZE && ip_mtudisc && ip && ip->ip_v == 4) {
106 		/*
107 		 * Check to see if we have a valid SA corresponding to
108 		 * the address in the ICMP message payload.
109 		 */
110 		ah = (struct ah *)((caddr_t)ip + (ip->ip_hl << 2));
111 		if ((sav = key_allocsa(AF_INET,
112 				       (caddr_t) &ip->ip_src,
113 				       (caddr_t) &ip->ip_dst,
114 				       IPPROTO_AH, ah->ah_spi)) == NULL)
115 			return NULL;
116 		if (sav->state != SADB_SASTATE_MATURE &&
117 		    sav->state != SADB_SASTATE_DYING) {
118 			key_freesav(sav);
119 			return NULL;
120 		}
121 
122 		/* XXX Further validation? */
123 
124 		key_freesav(sav);
125 
126 		/*
127 		 * Now that we've validated that we are actually communicating
128 		 * with the host indicated in the ICMP message, locate the
129 		 * ICMP header, recalculate the new MTU, and create the
130 		 * corresponding routing entry.
131 		 */
132 		icp = (struct icmp *)((caddr_t)ip -
133 		    offsetof(struct icmp, icmp_ip));
134 		icmp_mtudisc(icp, ip->ip_dst);
135 
136 		return NULL;
137 	}
138 #endif
139 
140 	return NULL;
141 }
142 
143 /* assumes that ip header and esp header are contiguous on mbuf */
144 void *
145 esp4_ctlinput(cmd, sa, v)
146 	int cmd;
147 	struct sockaddr *sa;
148 	void *v;
149 {
150 	struct ip *ip = v;
151 	struct esp *esp;
152 	struct icmp *icp;
153 	struct secasvar *sav;
154 
155 	if (sa->sa_family != AF_INET ||
156 	    sa->sa_len != sizeof(struct sockaddr_in))
157 		return NULL;
158 	if ((unsigned)cmd >= PRC_NCMDS)
159 		return NULL;
160 #ifndef notyet
161 	(void) ip; (void) esp; (void) icp; (void) sav;
162 #else
163 	if (cmd == PRC_MSGSIZE && ip_mtudisc && ip && ip->ip_v == 4) {
164 		/*
165 		 * Check to see if we have a valid SA corresponding to
166 		 * the address in the ICMP message payload.
167 		 */
168 		esp = (struct esp *)((caddr_t)ip + (ip->ip_hl << 2));
169 		if ((sav = key_allocsa(AF_INET,
170 				       (caddr_t) &ip->ip_src,
171 				       (caddr_t) &ip->ip_dst,
172 				       IPPROTO_ESP, esp->esp_spi)) == NULL)
173 			return NULL;
174 		if (sav->state != SADB_SASTATE_MATURE &&
175 		    sav->state != SADB_SASTATE_DYING) {
176 			key_freesav(sav);
177 			return NULL;
178 		}
179 
180 		/* XXX Further validation? */
181 
182 		key_freesav(sav);
183 
184 		/*
185 		 * Now that we've validated that we are actually communicating
186 		 * with the host indicated in the ICMP message, locate the
187 		 * ICMP header, recalculate the new MTU, and create the
188 		 * corresponding routing entry.
189 		 */
190 		icp = (struct icmp *)((caddr_t)ip -
191 		    offsetof(struct icmp, icmp_ip));
192 		icmp_mtudisc(icp, ip->ip_dst);
193 
194 		return NULL;
195 	}
196 #endif
197 
198 	return NULL;
199 }
200 
201 #ifdef INET6
202 void
203 esp6_ctlinput(cmd, sa, d)
204 	int cmd;
205 	struct sockaddr *sa;
206 	void *d;
207 {
208 	const struct newesp *espp;
209 	struct newesp esp;
210 	struct ip6ctlparam *ip6cp = NULL, ip6cp1;
211 	struct secasvar *sav;
212 	struct ip6_hdr *ip6;
213 	struct mbuf *m;
214 	int off;
215 	struct sockaddr_in6 *sa6_src, *sa6_dst;
216 
217 	if (sa->sa_family != AF_INET6 ||
218 	    sa->sa_len != sizeof(struct sockaddr_in6))
219 		return;
220 	if ((unsigned)cmd >= PRC_NCMDS)
221 		return;
222 
223 	/* if the parameter is from icmp6, decode it. */
224 	if (d != NULL) {
225 		ip6cp = (struct ip6ctlparam *)d;
226 		m = ip6cp->ip6c_m;
227 		ip6 = ip6cp->ip6c_ip6;
228 		off = ip6cp->ip6c_off;
229 	} else {
230 		m = NULL;
231 		ip6 = NULL;
232 	}
233 
234 	if (ip6) {
235 		/*
236 		 * Notify the error to all possible sockets via pfctlinput2.
237 		 * Since the upper layer information (such as protocol type,
238 		 * source and destination ports) is embedded in the encrypted
239 		 * data and might have been cut, we can't directly call
240 		 * an upper layer ctlinput function. However, the pcbnotify
241 		 * function will consider source and destination addresses
242 		 * as well as the flow info value, and may be able to find
243 		 * some PCB that should be notified.
244 		 * Although pfctlinput2 will call esp6_ctlinput(), there is
245 		 * no possibility of an infinite loop of function calls,
246 		 * because we don't pass the inner IPv6 header.
247 		 */
248 		bzero(&ip6cp1, sizeof(ip6cp1));
249 		ip6cp1.ip6c_src = ip6cp->ip6c_src;
250 		pfctlinput2(cmd, sa, (void *)&ip6cp1);
251 
252 		/*
253 		 * Then go to special cases that need ESP header information.
254 		 * XXX: We assume that when ip6 is non NULL,
255 		 * M and OFF are valid.
256 		 */
257 
258 		/* check if we can safely examine src and dst ports */
259 		if (m->m_pkthdr.len < off + sizeof(esp))
260 			return;
261 
262 		if (m->m_len < off + sizeof(esp)) {
263 			/*
264 			 * this should be rare case,
265 			 * so we compromise on this copy...
266 			 */
267 			m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
268 			espp = &esp;
269 		} else
270 			espp = (struct newesp*)(mtod(m, caddr_t) + off);
271 
272 		if (cmd == PRC_MSGSIZE) {
273 			int valid = 0;
274 
275 			/*
276 			 * Check to see if we have a valid SA corresponding to
277 			 * the address in the ICMP message payload.
278 			 */
279 			sa6_src = ip6cp->ip6c_src;
280 			sa6_dst = (struct sockaddr_in6 *)sa;
281 			sav = key_allocsa(AF_INET6,
282 					  (caddr_t)&sa6_src->sin6_addr,
283 					  (caddr_t)&sa6_dst->sin6_addr,
284 					  IPPROTO_ESP, espp->esp_spi);
285 			if (sav) {
286 				if (sav->state == SADB_SASTATE_MATURE ||
287 				    sav->state == SADB_SASTATE_DYING)
288 					valid++;
289 				key_freesav(sav);
290 			}
291 
292 			/* XXX Further validation? */
293 
294 			/*
295 			 * Depending on the value of "valid" and routing table
296 			 * size (mtudisc_{hi,lo}wat), we will:
297 			 * - recalcurate the new MTU and create the
298 			 *   corresponding routing entry, or
299 			 * - ignore the MTU change notification.
300 			 */
301 			icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
302 		}
303 	} else {
304 		/* we normally notify any pcb here */
305 	}
306 }
307 #endif /* INET6 */
308 
309 
310 /*FIXME: placebo for invalpcbcacheall. Fast-IPsec has no pcb cache? */
311 
312 void	ipsec_invalpcbcacheall(void);
313 void
314 ipsec_invalpcbcacheall(void)
315 {
316 }
317 
318 static int
319 sysctl_fast_ipsec(SYSCTLFN_ARGS)
320 {
321 	int error, t;
322 	struct sysctlnode node;
323 
324 	node = *rnode;
325 	t = *(int*)rnode->sysctl_data;
326 	node.sysctl_data = &t;
327 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
328 	if (error || newp == NULL)
329 		return (error);
330 
331 	switch (rnode->sysctl_num) {
332 	case IPSECCTL_DEF_ESP_TRANSLEV:
333 	case IPSECCTL_DEF_ESP_NETLEV:
334 	case IPSECCTL_DEF_AH_TRANSLEV:
335 	case IPSECCTL_DEF_AH_NETLEV:
336 		if (t != IPSEC_LEVEL_USE &&
337 		    t != IPSEC_LEVEL_REQUIRE)
338 			return (EINVAL);
339 		ipsec_invalpcbcacheall();
340 		break;
341       	case IPSECCTL_DEF_POLICY:
342 		if (t != IPSEC_POLICY_DISCARD &&
343 		    t != IPSEC_POLICY_NONE)
344 			return (EINVAL);
345 		ipsec_invalpcbcacheall();
346 		break;
347 	default:
348 		return (EINVAL);
349 	}
350 
351 	*(int*)rnode->sysctl_data = t;
352 
353 	return (0);
354 }
355 
356 /* XXX will need a different oid at parent */
357 /* @@@ i have called it "fast_ipsec" instead of "ipsec" */
358 SYSCTL_SETUP(sysctl_net_inet_fast_ipsec_setup, "sysctl net.inet.fast_ipsec subtree setup")
359 {
360 
361 	sysctl_createv(SYSCTL_PERMANENT,
362 		       CTLTYPE_NODE, "net", NULL,
363 		       NULL, 0, NULL, 0,
364 		       CTL_NET, CTL_EOL);
365 	sysctl_createv(SYSCTL_PERMANENT,
366 		       CTLTYPE_NODE, "inet", NULL,
367 		       NULL, 0, NULL, 0,
368 		       CTL_NET, PF_INET, CTL_EOL);
369 	sysctl_createv(SYSCTL_PERMANENT,
370 		       CTLTYPE_NODE, "fast_ipsec", NULL,
371 		       NULL, 0, NULL, 0,
372 		       CTL_NET, PF_INET, IPPROTO_AH, CTL_EOL);
373 
374 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
375 		       CTLTYPE_STRUCT, "stats", NULL,
376 		       NULL, 0, &ipsecstat, sizeof(ipsecstat),
377 		       CTL_NET, PF_INET, IPPROTO_AH,
378 		       IPSECCTL_STATS, CTL_EOL);
379 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
380 		       CTLTYPE_INT, "def_policy", NULL,
381 		       sysctl_fast_ipsec, 0, &ip4_def_policy.policy, 0,
382 		       CTL_NET, PF_INET, IPPROTO_AH,
383 		       IPSECCTL_DEF_POLICY, CTL_EOL);
384 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
385 		       CTLTYPE_INT, "esp_trans_deflev", NULL,
386 		       sysctl_fast_ipsec, 0, &ip4_esp_trans_deflev, 0,
387 		       CTL_NET, PF_INET, IPPROTO_AH,
388 		       IPSECCTL_DEF_ESP_TRANSLEV, CTL_EOL);
389 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
390 		       CTLTYPE_INT, "esp_net_deflev", NULL,
391 		       sysctl_fast_ipsec, 0, &ip4_esp_net_deflev, 0,
392 		       CTL_NET, PF_INET, IPPROTO_AH,
393 		       IPSECCTL_DEF_ESP_NETLEV, CTL_EOL);
394 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
395 		       CTLTYPE_INT, "ah_trans_deflev", NULL,
396 		       sysctl_fast_ipsec, 0, &ip4_ah_trans_deflev, 0,
397 		       CTL_NET, PF_INET, IPPROTO_AH,
398 		       IPSECCTL_DEF_AH_TRANSLEV, CTL_EOL);
399 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
400 		       CTLTYPE_INT, "ah_net_deflev", NULL,
401 		       sysctl_fast_ipsec, 0, &ip4_ah_net_deflev, 0,
402 		       CTL_NET, PF_INET, IPPROTO_AH,
403 		       IPSECCTL_DEF_AH_NETLEV, CTL_EOL);
404 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
405 		       CTLTYPE_INT, "ah_cleartos", NULL,
406 		       NULL, 0, &/*ip4_*/ah_cleartos, 0,
407 		       CTL_NET, PF_INET, IPPROTO_AH,
408 		       IPSECCTL_AH_CLEARTOS, CTL_EOL);
409 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
410 		       CTLTYPE_INT, "ah_offsetmask", NULL,
411 		       NULL, 0, &ip4_ah_offsetmask, 0,
412 		       CTL_NET, PF_INET, IPPROTO_AH,
413 		       IPSECCTL_AH_OFFSETMASK, CTL_EOL);
414 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
415 		       CTLTYPE_INT, "dfbit", NULL,
416 		       NULL, 0, &ip4_ipsec_dfbit, 0,
417 		       CTL_NET, PF_INET, IPPROTO_AH,
418 		       IPSECCTL_DFBIT, CTL_EOL);
419 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
420 		       CTLTYPE_INT, "ecn", NULL,
421 		       NULL, 0, &ip4_ipsec_ecn, 0,
422 		       CTL_NET, PF_INET, IPPROTO_AH,
423 		       IPSECCTL_ECN, CTL_EOL);
424 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
425 		       CTLTYPE_INT, "debug", NULL,
426 		       NULL, 0, &ipsec_debug, 0,
427 		       CTL_NET, PF_INET, IPPROTO_AH,
428 		       IPSECCTL_DEBUG, CTL_EOL);
429 
430 	/*
431 	 * "aliases" for the fast ipsec subtree
432 	 */
433 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_ALIAS,
434 		       CTLTYPE_NODE, "fast_esp", NULL,
435 		       NULL, IPPROTO_AH, NULL, 0,
436 		       CTL_NET, PF_INET, IPPROTO_ESP, CTL_EOL);
437 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_ALIAS,
438 		       CTLTYPE_NODE, "fast_ipcomp", NULL,
439 		       NULL, IPPROTO_AH, NULL, 0,
440 		       CTL_NET, PF_INET, IPPROTO_IPCOMP, CTL_EOL);
441 	sysctl_createv(SYSCTL_PERMANENT|SYSCTL_ALIAS,
442 		       CTLTYPE_NODE, "fast_ah", NULL,
443 		       NULL, IPPROTO_AH, NULL, 0,
444 		       CTL_NET, PF_INET, CTL_CREATE, CTL_EOL);
445 }
446