1/*-
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: head/sys/netinet/ip_ipsec.c 171732 2007-08-05 16:16:15Z bz $
30 */
31
32#include "opt_ipsec.h"
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37#include <sys/malloc.h>
38#include <sys/mbuf.h>
39#include <sys/protosw.h>
40#include <sys/socket.h>
41#include <sys/socketvar.h>
42#include <sys/sysctl.h>
43
44#include <net/if.h>
45#include <net/route.h>
46
47#include <netinet/in.h>
48#include <netinet/in_systm.h>
49#include <netinet/in_var.h>
50#include <netinet/ip.h>
51#include <netinet/in_pcb.h>
52#include <netinet/ip_var.h>
53#include <netinet/ip_options.h>
54#include <netinet/ip_ipsec.h>
55
56#include <machine/in_cksum.h>
57
58#ifdef IPSEC
59#include <netipsec/ipsec.h>
60#include <netipsec/xform.h>
61#include <netipsec/key.h>
62#endif /*IPSEC*/
63
64extern struct protosw inetsw[];
65
66/*
67 * Check if we have to jump over firewall processing for this packet.
68 * Called from ip_input().
69 * 1 = jump over firewall, 0 = packet goes through firewall.
70 */
71int
72ip_ipsec_filtertunnel(struct mbuf *m)
73{
74#if defined(IPSEC) && !defined(IPSEC_FILTERTUNNEL)
75 /*
76 * Bypass packet filtering for packets from a tunnel.
77 */
78 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
79 return 1;
80#endif
81 return 0;
82}
83
84/*
85 * Check if this packet has an active SA and needs to be dropped instead
86 * of forwarded.
87 * Called from ip_input().
88 * 1 = drop packet, 0 = forward packet.
89 */
90int
91ip_ipsec_fwd(struct mbuf *m)
92{
93#ifdef IPSEC
94 struct m_tag *mtag;
95 struct tdb_ident *tdbi;
96 struct secpolicy *sp;
97 int s, error;
98
99 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
100 s = splnet();
101 if (mtag != NULL) {
102 tdbi = (struct tdb_ident *)(mtag + 1);
103 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
104 } else {
105 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
106 IP_FORWARDING, &error);
107 }
108 if (sp == NULL) { /* NB: can happen if error */
109 splx(s);
110 /*XXX error stat???*/
111 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
112 return 1;
113 }
114
115 /*
116 * Check security policy against packet attributes.
117 */
118 error = ipsec_in_reject(sp, m);
119 KEY_FREESP(&sp);
120 splx(s);
121 if (error) {
122 ipstat.ips_cantforward++;
123 return 1;
124 }
125#endif /* IPSEC */
126 return 0;
127}
128
129/*
130 * Check if protocol type doesn't have a further header and do IPSEC
131 * decryption or reject right now. Protocols with further headers get
132 * their IPSEC treatment within the protocol specific processing.
133 * Called from ip_input().
134 * 1 = drop packet, 0 = continue processing packet.
135 */
136int
137ip_ipsec_input(struct mbuf *m)
138{
139 struct ip *ip = mtod(m, struct ip *);
140#ifdef IPSEC
141 struct m_tag *mtag;
142 struct tdb_ident *tdbi;
143 struct secpolicy *sp;
144 int s, error;
145 /*
146 * enforce IPsec policy checking if we are seeing last header.
147 * note that we do not visit this with protocols with pcb layer
148 * code - like udp/tcp/raw ip.
149 */
150 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
151 /*
152 * Check if the packet has already had IPsec processing
153 * done. If so, then just pass it along. This tag gets
154 * set during AH, ESP, etc. input handling, before the
155 * packet is returned to the ip input queue for delivery.
156 */
157 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
158 s = splnet();
159 if (mtag != NULL) {
160 tdbi = (struct tdb_ident *)(mtag + 1);
161 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
162 } else {
163 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
164 IP_FORWARDING, &error);
165 }
166 if (sp != NULL) {
167 /*
168 * Check security policy against packet attributes.
169 */
170 error = ipsec_in_reject(sp, m);
171 KEY_FREESP(&sp);
172 } else {
173 /* XXX error stat??? */
174 error = EINVAL;
175 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
176 return 1;
177 }
178 splx(s);
179 if (error)
180 return 1;
181 }
182#endif /* IPSEC */
183 return 0;
184}
185
186/*
187 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
188 * Called from ip_forward().
189 * Returns MTU suggestion for ICMP needfrag reply.
190 */
191int
192ip_ipsec_mtu(struct mbuf *m)
193{
194 int mtu = 0;
195 /*
196 * If the packet is routed over IPsec tunnel, tell the
197 * originator the tunnel MTU.
198 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
199 * XXX quickhack!!!
200 */
201 struct secpolicy *sp = NULL;
202 int ipsecerror;
203 int ipsechdr;
204 struct route *ro;
205 sp = ipsec_getpolicybyaddr(m,
206 IPSEC_DIR_OUTBOUND,
207 IP_FORWARDING,
208 &ipsecerror);
209 if (sp != NULL) {
210 /* count IPsec header size */
211 ipsechdr = ipsec4_hdrsiz(m,
212 IPSEC_DIR_OUTBOUND,
213 NULL);
214
215 /*
216 * find the correct route for outer IPv4
217 * header, compute tunnel MTU.
218 */
219 if (sp->req != NULL &&
220 sp->req->sav != NULL &&
221 sp->req->sav->sah != NULL) {
222 ro = &sp->req->sav->sah->sa_route;
223 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
224 mtu =
225 ro->ro_rt->rt_rmx.rmx_mtu ?
226 ro->ro_rt->rt_rmx.rmx_mtu :
227 ro->ro_rt->rt_ifp->if_mtu;
228 mtu -= ipsechdr;
229 }
230 }
231 KEY_FREESP(&sp);
232 }
233 return mtu;
234}
235
236/*
237 *
238 * Called from ip_output().
239 * 1 = drop packet, 0 = continue processing packet,
240 * -1 = packet was reinjected and stop processing packet
241 */
242int
243ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
244 struct route **ro, struct route *iproute, struct sockaddr_in **dst,
245 struct in_ifaddr **ia, struct ifnet **ifp)
246{
247#ifdef IPSEC
248 struct secpolicy *sp = NULL;
249 struct ip *ip = mtod(*m, struct ip *);
250 struct tdb_ident *tdbi;
251 struct m_tag *mtag;
252 int s;
253 /*
254 * Check the security policy (SP) for the packet and, if
255 * required, do IPsec-related processing. There are two
256 * cases here; the first time a packet is sent through
257 * it will be untagged and handled by ipsec4_checkpolicy.
258 * If the packet is resubmitted to ip_output (e.g. after
259 * AH, ESP, etc. processing), there will be a tag to bypass
260 * the lookup and related policy checking.
261 */
262 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
263 s = splnet();
264 if (mtag != NULL) {
265 tdbi = (struct tdb_ident *)(mtag + 1);
266 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
267 if (sp == NULL)
268 *error = -EINVAL; /* force silent drop */
269 m_tag_delete(*m, mtag);
270 } else {
271 sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
272 error, inp);
273 }
274 /*
275 * There are four return cases:
276 * sp != NULL apply IPsec policy
277 * sp == NULL, error == 0 no IPsec handling needed
278 * sp == NULL, error == -EINVAL discard packet w/o error
279 * sp == NULL, error != 0 discard packet, report error
280 */
281 if (sp != NULL) {
282 /* Loop detection, check if ipsec processing already done */
283 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
284 for (mtag = m_tag_first(*m); mtag != NULL;
285 mtag = m_tag_next(*m, mtag)) {
286 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
287 continue;
288 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
289 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
290 continue;
291 /*
292 * Check if policy has an SA associated with it.
293 * This can happen when an SP has yet to acquire
294 * an SA; e.g. on first reference. If it occurs,
295 * then we let ipsec4_process_packet do its thing.
296 */
297 if (sp->req->sav == NULL)
298 break;
299 tdbi = (struct tdb_ident *)(mtag + 1);
300 if (tdbi->spi == sp->req->sav->spi &&
301 tdbi->proto == sp->req->sav->sah->saidx.proto &&
302 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
303 sizeof (union sockaddr_union)) == 0) {
304 /*
305 * No IPsec processing is needed, free
306 * reference to SP.
307 *
308 * NB: null pointer to avoid free at
309 * done: below.
310 */
311 KEY_FREESP(&sp), sp = NULL;
312 splx(s);
313 goto done;
314 }
315 }
316
317 /*
318 * Do delayed checksums now because we send before
319 * this is done in the normal processing path.
320 */
321 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
322 in_delayed_cksum(*m);
323 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
324 }
325
326 ip->ip_len = htons(ip->ip_len);
327 ip->ip_off = htons(ip->ip_off);
328
329 /* NB: callee frees mbuf */
330 *error = ipsec4_process_packet(*m, sp->req, *flags, 0);
331 /*
332 * Preserve KAME behaviour: ENOENT can be returned
333 * when an SA acquire is in progress. Don't propagate
334 * this to user-level; it confuses applications.
335 *
336 * XXX this will go away when the SADB is redone.
337 */
338 if (*error == ENOENT)
339 *error = 0;
340 splx(s);
341 goto reinjected;
342 } else { /* sp == NULL */
343 splx(s);
344
345 if (*error != 0) {
346 /*
347 * Hack: -EINVAL is used to signal that a packet
348 * should be silently discarded. This is typically
349 * because we asked key management for an SA and
350 * it was delayed (e.g. kicked up to IKE).
351 */
352 if (*error == -EINVAL)
353 *error = 0;
354 goto bad;
355 } else {
356 /* No IPsec processing for this packet. */
357 }
358#ifdef notyet
359 /*
360 * If deferred crypto processing is needed, check that
361 * the interface supports it.
362 */
363 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
364 if (mtag != NULL && ((*ifp)->if_capenable & IFCAP_IPSEC) == 0) {
365 /* notify IPsec to do its own crypto */
366 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
367 *error = EHOSTUNREACH;
368 goto bad;
369 }
370#endif
371 }
372done:
373 if (sp != NULL)
374 KEY_FREESP(&sp);
375 return 0;
376reinjected:
377 if (sp != NULL)
378 KEY_FREESP(&sp);
379 return -1;
380bad:
381 if (sp != NULL)
382 KEY_FREESP(&sp);
383 return 1;
384#endif /* IPSEC */
385 return 0;
386}
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: head/sys/netinet/ip_ipsec.c 171732 2007-08-05 16:16:15Z bz $
30 */
31
32#include "opt_ipsec.h"
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37#include <sys/malloc.h>
38#include <sys/mbuf.h>
39#include <sys/protosw.h>
40#include <sys/socket.h>
41#include <sys/socketvar.h>
42#include <sys/sysctl.h>
43
44#include <net/if.h>
45#include <net/route.h>
46
47#include <netinet/in.h>
48#include <netinet/in_systm.h>
49#include <netinet/in_var.h>
50#include <netinet/ip.h>
51#include <netinet/in_pcb.h>
52#include <netinet/ip_var.h>
53#include <netinet/ip_options.h>
54#include <netinet/ip_ipsec.h>
55
56#include <machine/in_cksum.h>
57
58#ifdef IPSEC
59#include <netipsec/ipsec.h>
60#include <netipsec/xform.h>
61#include <netipsec/key.h>
62#endif /*IPSEC*/
63
64extern struct protosw inetsw[];
65
66/*
67 * Check if we have to jump over firewall processing for this packet.
68 * Called from ip_input().
69 * 1 = jump over firewall, 0 = packet goes through firewall.
70 */
71int
72ip_ipsec_filtertunnel(struct mbuf *m)
73{
74#if defined(IPSEC) && !defined(IPSEC_FILTERTUNNEL)
75 /*
76 * Bypass packet filtering for packets from a tunnel.
77 */
78 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
79 return 1;
80#endif
81 return 0;
82}
83
84/*
85 * Check if this packet has an active SA and needs to be dropped instead
86 * of forwarded.
87 * Called from ip_input().
88 * 1 = drop packet, 0 = forward packet.
89 */
90int
91ip_ipsec_fwd(struct mbuf *m)
92{
93#ifdef IPSEC
94 struct m_tag *mtag;
95 struct tdb_ident *tdbi;
96 struct secpolicy *sp;
97 int s, error;
98
99 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
100 s = splnet();
101 if (mtag != NULL) {
102 tdbi = (struct tdb_ident *)(mtag + 1);
103 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
104 } else {
105 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
106 IP_FORWARDING, &error);
107 }
108 if (sp == NULL) { /* NB: can happen if error */
109 splx(s);
110 /*XXX error stat???*/
111 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
112 return 1;
113 }
114
115 /*
116 * Check security policy against packet attributes.
117 */
118 error = ipsec_in_reject(sp, m);
119 KEY_FREESP(&sp);
120 splx(s);
121 if (error) {
122 ipstat.ips_cantforward++;
123 return 1;
124 }
125#endif /* IPSEC */
126 return 0;
127}
128
129/*
130 * Check if protocol type doesn't have a further header and do IPSEC
131 * decryption or reject right now. Protocols with further headers get
132 * their IPSEC treatment within the protocol specific processing.
133 * Called from ip_input().
134 * 1 = drop packet, 0 = continue processing packet.
135 */
136int
137ip_ipsec_input(struct mbuf *m)
138{
139 struct ip *ip = mtod(m, struct ip *);
140#ifdef IPSEC
141 struct m_tag *mtag;
142 struct tdb_ident *tdbi;
143 struct secpolicy *sp;
144 int s, error;
145 /*
146 * enforce IPsec policy checking if we are seeing last header.
147 * note that we do not visit this with protocols with pcb layer
148 * code - like udp/tcp/raw ip.
149 */
150 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
151 /*
152 * Check if the packet has already had IPsec processing
153 * done. If so, then just pass it along. This tag gets
154 * set during AH, ESP, etc. input handling, before the
155 * packet is returned to the ip input queue for delivery.
156 */
157 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
158 s = splnet();
159 if (mtag != NULL) {
160 tdbi = (struct tdb_ident *)(mtag + 1);
161 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
162 } else {
163 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
164 IP_FORWARDING, &error);
165 }
166 if (sp != NULL) {
167 /*
168 * Check security policy against packet attributes.
169 */
170 error = ipsec_in_reject(sp, m);
171 KEY_FREESP(&sp);
172 } else {
173 /* XXX error stat??? */
174 error = EINVAL;
175 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
176 return 1;
177 }
178 splx(s);
179 if (error)
180 return 1;
181 }
182#endif /* IPSEC */
183 return 0;
184}
185
186/*
187 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
188 * Called from ip_forward().
189 * Returns MTU suggestion for ICMP needfrag reply.
190 */
191int
192ip_ipsec_mtu(struct mbuf *m)
193{
194 int mtu = 0;
195 /*
196 * If the packet is routed over IPsec tunnel, tell the
197 * originator the tunnel MTU.
198 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
199 * XXX quickhack!!!
200 */
201 struct secpolicy *sp = NULL;
202 int ipsecerror;
203 int ipsechdr;
204 struct route *ro;
205 sp = ipsec_getpolicybyaddr(m,
206 IPSEC_DIR_OUTBOUND,
207 IP_FORWARDING,
208 &ipsecerror);
209 if (sp != NULL) {
210 /* count IPsec header size */
211 ipsechdr = ipsec4_hdrsiz(m,
212 IPSEC_DIR_OUTBOUND,
213 NULL);
214
215 /*
216 * find the correct route for outer IPv4
217 * header, compute tunnel MTU.
218 */
219 if (sp->req != NULL &&
220 sp->req->sav != NULL &&
221 sp->req->sav->sah != NULL) {
222 ro = &sp->req->sav->sah->sa_route;
223 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
224 mtu =
225 ro->ro_rt->rt_rmx.rmx_mtu ?
226 ro->ro_rt->rt_rmx.rmx_mtu :
227 ro->ro_rt->rt_ifp->if_mtu;
228 mtu -= ipsechdr;
229 }
230 }
231 KEY_FREESP(&sp);
232 }
233 return mtu;
234}
235
236/*
237 *
238 * Called from ip_output().
239 * 1 = drop packet, 0 = continue processing packet,
240 * -1 = packet was reinjected and stop processing packet
241 */
242int
243ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
244 struct route **ro, struct route *iproute, struct sockaddr_in **dst,
245 struct in_ifaddr **ia, struct ifnet **ifp)
246{
247#ifdef IPSEC
248 struct secpolicy *sp = NULL;
249 struct ip *ip = mtod(*m, struct ip *);
250 struct tdb_ident *tdbi;
251 struct m_tag *mtag;
252 int s;
253 /*
254 * Check the security policy (SP) for the packet and, if
255 * required, do IPsec-related processing. There are two
256 * cases here; the first time a packet is sent through
257 * it will be untagged and handled by ipsec4_checkpolicy.
258 * If the packet is resubmitted to ip_output (e.g. after
259 * AH, ESP, etc. processing), there will be a tag to bypass
260 * the lookup and related policy checking.
261 */
262 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
263 s = splnet();
264 if (mtag != NULL) {
265 tdbi = (struct tdb_ident *)(mtag + 1);
266 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
267 if (sp == NULL)
268 *error = -EINVAL; /* force silent drop */
269 m_tag_delete(*m, mtag);
270 } else {
271 sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
272 error, inp);
273 }
274 /*
275 * There are four return cases:
276 * sp != NULL apply IPsec policy
277 * sp == NULL, error == 0 no IPsec handling needed
278 * sp == NULL, error == -EINVAL discard packet w/o error
279 * sp == NULL, error != 0 discard packet, report error
280 */
281 if (sp != NULL) {
282 /* Loop detection, check if ipsec processing already done */
283 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
284 for (mtag = m_tag_first(*m); mtag != NULL;
285 mtag = m_tag_next(*m, mtag)) {
286 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
287 continue;
288 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
289 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
290 continue;
291 /*
292 * Check if policy has an SA associated with it.
293 * This can happen when an SP has yet to acquire
294 * an SA; e.g. on first reference. If it occurs,
295 * then we let ipsec4_process_packet do its thing.
296 */
297 if (sp->req->sav == NULL)
298 break;
299 tdbi = (struct tdb_ident *)(mtag + 1);
300 if (tdbi->spi == sp->req->sav->spi &&
301 tdbi->proto == sp->req->sav->sah->saidx.proto &&
302 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
303 sizeof (union sockaddr_union)) == 0) {
304 /*
305 * No IPsec processing is needed, free
306 * reference to SP.
307 *
308 * NB: null pointer to avoid free at
309 * done: below.
310 */
311 KEY_FREESP(&sp), sp = NULL;
312 splx(s);
313 goto done;
314 }
315 }
316
317 /*
318 * Do delayed checksums now because we send before
319 * this is done in the normal processing path.
320 */
321 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
322 in_delayed_cksum(*m);
323 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
324 }
325
326 ip->ip_len = htons(ip->ip_len);
327 ip->ip_off = htons(ip->ip_off);
328
329 /* NB: callee frees mbuf */
330 *error = ipsec4_process_packet(*m, sp->req, *flags, 0);
331 /*
332 * Preserve KAME behaviour: ENOENT can be returned
333 * when an SA acquire is in progress. Don't propagate
334 * this to user-level; it confuses applications.
335 *
336 * XXX this will go away when the SADB is redone.
337 */
338 if (*error == ENOENT)
339 *error = 0;
340 splx(s);
341 goto reinjected;
342 } else { /* sp == NULL */
343 splx(s);
344
345 if (*error != 0) {
346 /*
347 * Hack: -EINVAL is used to signal that a packet
348 * should be silently discarded. This is typically
349 * because we asked key management for an SA and
350 * it was delayed (e.g. kicked up to IKE).
351 */
352 if (*error == -EINVAL)
353 *error = 0;
354 goto bad;
355 } else {
356 /* No IPsec processing for this packet. */
357 }
358#ifdef notyet
359 /*
360 * If deferred crypto processing is needed, check that
361 * the interface supports it.
362 */
363 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
364 if (mtag != NULL && ((*ifp)->if_capenable & IFCAP_IPSEC) == 0) {
365 /* notify IPsec to do its own crypto */
366 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
367 *error = EHOSTUNREACH;
368 goto bad;
369 }
370#endif
371 }
372done:
373 if (sp != NULL)
374 KEY_FREESP(&sp);
375 return 0;
376reinjected:
377 if (sp != NULL)
378 KEY_FREESP(&sp);
379 return -1;
380bad:
381 if (sp != NULL)
382 KEY_FREESP(&sp);
383 return 1;
384#endif /* IPSEC */
385 return 0;
386}