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
30#include <sys/cdefs.h>
| 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
30#include <sys/cdefs.h>
|
31__FBSDID("$FreeBSD: head/sys/netinet/ip_ipsec.c 257176 2013-10-26 17:58:36Z glebius $");
| 31__FBSDID("$FreeBSD: head/sys/netinet/ip_ipsec.c 262763 2014-03-05 01:17:47Z glebius $");
|
32
33#include "opt_ipsec.h"
34#include "opt_sctp.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/errno.h>
39#include <sys/kernel.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/protosw.h>
43#include <sys/socket.h>
44#include <sys/socketvar.h>
45#include <sys/sysctl.h>
46
47#include <net/if.h>
48#include <net/if_var.h>
49#include <net/route.h>
50#include <net/vnet.h>
51
52#include <netinet/in.h>
53#include <netinet/in_systm.h>
54#include <netinet/in_var.h>
55#include <netinet/ip.h>
56#include <netinet/in_pcb.h>
57#include <netinet/ip_var.h>
58#include <netinet/ip_options.h>
59#include <netinet/ip_ipsec.h>
60#ifdef SCTP
61#include <netinet/sctp_crc32.h>
62#endif
63
64#include <machine/in_cksum.h>
65
66#ifdef IPSEC
67#include <netipsec/ipsec.h>
68#include <netipsec/xform.h>
69#include <netipsec/key.h>
70#endif /*IPSEC*/
71
72extern struct protosw inetsw[];
73
74#ifdef IPSEC
75#ifdef IPSEC_FILTERTUNNEL
76static VNET_DEFINE(int, ip4_ipsec_filtertunnel) = 1;
77#else
78static VNET_DEFINE(int, ip4_ipsec_filtertunnel) = 0;
79#endif
80#define V_ip4_ipsec_filtertunnel VNET(ip4_ipsec_filtertunnel)
81
82SYSCTL_DECL(_net_inet_ipsec);
83SYSCTL_VNET_INT(_net_inet_ipsec, OID_AUTO, filtertunnel,
84 CTLFLAG_RW, &VNET_NAME(ip4_ipsec_filtertunnel), 0,
85 "If set filter packets from an IPsec tunnel.");
86#endif /* IPSEC */
87
88/*
89 * Check if we have to jump over firewall processing for this packet.
90 * Called from ip_input().
91 * 1 = jump over firewall, 0 = packet goes through firewall.
92 */
93int
94ip_ipsec_filtertunnel(struct mbuf *m)
95{
96#ifdef IPSEC
97
98 /*
99 * Bypass packet filtering for packets previously handled by IPsec.
100 */
101 if (!V_ip4_ipsec_filtertunnel &&
102 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
103 return 1;
104#endif
105 return 0;
106}
107
108/*
109 * Check if this packet has an active SA and needs to be dropped instead
110 * of forwarded.
111 * Called from ip_input().
112 * 1 = drop packet, 0 = forward packet.
113 */
114int
115ip_ipsec_fwd(struct mbuf *m)
116{
117#ifdef IPSEC
118 struct m_tag *mtag;
119 struct tdb_ident *tdbi;
120 struct secpolicy *sp;
121 int error;
122
123 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
124 if (mtag != NULL) {
125 tdbi = (struct tdb_ident *)(mtag + 1);
126 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
127 } else {
128 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
129 IP_FORWARDING, &error);
130 }
131 if (sp == NULL) { /* NB: can happen if error */
132 /*XXX error stat???*/
133 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
134 return 1;
135 }
136
137 /*
138 * Check security policy against packet attributes.
139 */
140 error = ipsec_in_reject(sp, m);
141 KEY_FREESP(&sp);
142 if (error) {
143 IPSTAT_INC(ips_cantforward);
144 return 1;
145 }
146#endif /* IPSEC */
147 return 0;
148}
149
150/*
151 * Check if protocol type doesn't have a further header and do IPSEC
152 * decryption or reject right now. Protocols with further headers get
153 * their IPSEC treatment within the protocol specific processing.
154 * Called from ip_input().
155 * 1 = drop packet, 0 = continue processing packet.
156 */
157int
158ip_ipsec_input(struct mbuf *m)
159{
160#ifdef IPSEC
161 struct ip *ip = mtod(m, struct ip *);
162 struct m_tag *mtag;
163 struct tdb_ident *tdbi;
164 struct secpolicy *sp;
165 int error;
166 /*
167 * enforce IPsec policy checking if we are seeing last header.
168 * note that we do not visit this with protocols with pcb layer
169 * code - like udp/tcp/raw ip.
170 */
171 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
172 /*
173 * Check if the packet has already had IPsec processing
174 * done. If so, then just pass it along. This tag gets
175 * set during AH, ESP, etc. input handling, before the
176 * packet is returned to the ip input queue for delivery.
177 */
178 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
179 if (mtag != NULL) {
180 tdbi = (struct tdb_ident *)(mtag + 1);
181 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
182 } else {
183 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
184 IP_FORWARDING, &error);
185 }
186 if (sp != NULL) {
187 /*
188 * Check security policy against packet attributes.
189 */
190 error = ipsec_in_reject(sp, m);
191 KEY_FREESP(&sp);
192 } else {
193 /* XXX error stat??? */
194 error = EINVAL;
195 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
196 return 1;
197 }
198 if (error)
199 return 1;
200 }
201#endif /* IPSEC */
202 return 0;
203}
204
205/*
206 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
207 * Called from ip_forward().
208 * Returns MTU suggestion for ICMP needfrag reply.
209 */
210int
211ip_ipsec_mtu(struct mbuf *m, int mtu)
212{
213 /*
214 * If the packet is routed over IPsec tunnel, tell the
215 * originator the tunnel MTU.
216 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
217 * XXX quickhack!!!
218 */
219 struct secpolicy *sp = NULL;
220 int ipsecerror;
221 int ipsechdr;
222 struct route *ro;
223 sp = ipsec_getpolicybyaddr(m,
224 IPSEC_DIR_OUTBOUND,
225 IP_FORWARDING,
226 &ipsecerror);
227 if (sp != NULL) {
228 /* count IPsec header size */
229 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
230
231 /*
232 * find the correct route for outer IPv4
233 * header, compute tunnel MTU.
234 */
235 if (sp->req != NULL &&
236 sp->req->sav != NULL &&
237 sp->req->sav->sah != NULL) {
238 ro = &sp->req->sav->sah->route_cache.sa_route;
239 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
| 32
33#include "opt_ipsec.h"
34#include "opt_sctp.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/errno.h>
39#include <sys/kernel.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/protosw.h>
43#include <sys/socket.h>
44#include <sys/socketvar.h>
45#include <sys/sysctl.h>
46
47#include <net/if.h>
48#include <net/if_var.h>
49#include <net/route.h>
50#include <net/vnet.h>
51
52#include <netinet/in.h>
53#include <netinet/in_systm.h>
54#include <netinet/in_var.h>
55#include <netinet/ip.h>
56#include <netinet/in_pcb.h>
57#include <netinet/ip_var.h>
58#include <netinet/ip_options.h>
59#include <netinet/ip_ipsec.h>
60#ifdef SCTP
61#include <netinet/sctp_crc32.h>
62#endif
63
64#include <machine/in_cksum.h>
65
66#ifdef IPSEC
67#include <netipsec/ipsec.h>
68#include <netipsec/xform.h>
69#include <netipsec/key.h>
70#endif /*IPSEC*/
71
72extern struct protosw inetsw[];
73
74#ifdef IPSEC
75#ifdef IPSEC_FILTERTUNNEL
76static VNET_DEFINE(int, ip4_ipsec_filtertunnel) = 1;
77#else
78static VNET_DEFINE(int, ip4_ipsec_filtertunnel) = 0;
79#endif
80#define V_ip4_ipsec_filtertunnel VNET(ip4_ipsec_filtertunnel)
81
82SYSCTL_DECL(_net_inet_ipsec);
83SYSCTL_VNET_INT(_net_inet_ipsec, OID_AUTO, filtertunnel,
84 CTLFLAG_RW, &VNET_NAME(ip4_ipsec_filtertunnel), 0,
85 "If set filter packets from an IPsec tunnel.");
86#endif /* IPSEC */
87
88/*
89 * Check if we have to jump over firewall processing for this packet.
90 * Called from ip_input().
91 * 1 = jump over firewall, 0 = packet goes through firewall.
92 */
93int
94ip_ipsec_filtertunnel(struct mbuf *m)
95{
96#ifdef IPSEC
97
98 /*
99 * Bypass packet filtering for packets previously handled by IPsec.
100 */
101 if (!V_ip4_ipsec_filtertunnel &&
102 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
103 return 1;
104#endif
105 return 0;
106}
107
108/*
109 * Check if this packet has an active SA and needs to be dropped instead
110 * of forwarded.
111 * Called from ip_input().
112 * 1 = drop packet, 0 = forward packet.
113 */
114int
115ip_ipsec_fwd(struct mbuf *m)
116{
117#ifdef IPSEC
118 struct m_tag *mtag;
119 struct tdb_ident *tdbi;
120 struct secpolicy *sp;
121 int error;
122
123 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
124 if (mtag != NULL) {
125 tdbi = (struct tdb_ident *)(mtag + 1);
126 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
127 } else {
128 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
129 IP_FORWARDING, &error);
130 }
131 if (sp == NULL) { /* NB: can happen if error */
132 /*XXX error stat???*/
133 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
134 return 1;
135 }
136
137 /*
138 * Check security policy against packet attributes.
139 */
140 error = ipsec_in_reject(sp, m);
141 KEY_FREESP(&sp);
142 if (error) {
143 IPSTAT_INC(ips_cantforward);
144 return 1;
145 }
146#endif /* IPSEC */
147 return 0;
148}
149
150/*
151 * Check if protocol type doesn't have a further header and do IPSEC
152 * decryption or reject right now. Protocols with further headers get
153 * their IPSEC treatment within the protocol specific processing.
154 * Called from ip_input().
155 * 1 = drop packet, 0 = continue processing packet.
156 */
157int
158ip_ipsec_input(struct mbuf *m)
159{
160#ifdef IPSEC
161 struct ip *ip = mtod(m, struct ip *);
162 struct m_tag *mtag;
163 struct tdb_ident *tdbi;
164 struct secpolicy *sp;
165 int error;
166 /*
167 * enforce IPsec policy checking if we are seeing last header.
168 * note that we do not visit this with protocols with pcb layer
169 * code - like udp/tcp/raw ip.
170 */
171 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
172 /*
173 * Check if the packet has already had IPsec processing
174 * done. If so, then just pass it along. This tag gets
175 * set during AH, ESP, etc. input handling, before the
176 * packet is returned to the ip input queue for delivery.
177 */
178 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
179 if (mtag != NULL) {
180 tdbi = (struct tdb_ident *)(mtag + 1);
181 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
182 } else {
183 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
184 IP_FORWARDING, &error);
185 }
186 if (sp != NULL) {
187 /*
188 * Check security policy against packet attributes.
189 */
190 error = ipsec_in_reject(sp, m);
191 KEY_FREESP(&sp);
192 } else {
193 /* XXX error stat??? */
194 error = EINVAL;
195 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
196 return 1;
197 }
198 if (error)
199 return 1;
200 }
201#endif /* IPSEC */
202 return 0;
203}
204
205/*
206 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
207 * Called from ip_forward().
208 * Returns MTU suggestion for ICMP needfrag reply.
209 */
210int
211ip_ipsec_mtu(struct mbuf *m, int mtu)
212{
213 /*
214 * If the packet is routed over IPsec tunnel, tell the
215 * originator the tunnel MTU.
216 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
217 * XXX quickhack!!!
218 */
219 struct secpolicy *sp = NULL;
220 int ipsecerror;
221 int ipsechdr;
222 struct route *ro;
223 sp = ipsec_getpolicybyaddr(m,
224 IPSEC_DIR_OUTBOUND,
225 IP_FORWARDING,
226 &ipsecerror);
227 if (sp != NULL) {
228 /* count IPsec header size */
229 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
230
231 /*
232 * find the correct route for outer IPv4
233 * header, compute tunnel MTU.
234 */
235 if (sp->req != NULL &&
236 sp->req->sav != NULL &&
237 sp->req->sav->sah != NULL) {
238 ro = &sp->req->sav->sah->route_cache.sa_route;
239 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
|
240 mtu =
241 ro->ro_rt->rt_rmx.rmx_mtu ?
242 ro->ro_rt->rt_rmx.rmx_mtu :
| 240 mtu = ro->ro_rt->rt_mtu ? ro->ro_rt->rt_mtu :
|
243 ro->ro_rt->rt_ifp->if_mtu;
244 mtu -= ipsechdr;
245 }
246 }
247 KEY_FREESP(&sp);
248 }
249 return mtu;
250}
251
252/*
253 *
254 * Called from ip_output().
255 * 1 = drop packet, 0 = continue processing packet,
256 * -1 = packet was reinjected and stop processing packet
257 */
258int
259ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error)
260{
261#ifdef IPSEC
262 struct secpolicy *sp = NULL;
263 struct tdb_ident *tdbi;
264 struct m_tag *mtag;
265 /*
266 * Check the security policy (SP) for the packet and, if
267 * required, do IPsec-related processing. There are two
268 * cases here; the first time a packet is sent through
269 * it will be untagged and handled by ipsec4_checkpolicy.
270 * If the packet is resubmitted to ip_output (e.g. after
271 * AH, ESP, etc. processing), there will be a tag to bypass
272 * the lookup and related policy checking.
273 */
274 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
275 if (mtag != NULL) {
276 tdbi = (struct tdb_ident *)(mtag + 1);
277 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
278 if (sp == NULL)
279 *error = -EINVAL; /* force silent drop */
280 m_tag_delete(*m, mtag);
281 } else {
282 sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
283 error, inp);
284 }
285 /*
286 * There are four return cases:
287 * sp != NULL apply IPsec policy
288 * sp == NULL, error == 0 no IPsec handling needed
289 * sp == NULL, error == -EINVAL discard packet w/o error
290 * sp == NULL, error != 0 discard packet, report error
291 */
292 if (sp != NULL) {
293 /* Loop detection, check if ipsec processing already done */
294 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
295 for (mtag = m_tag_first(*m); mtag != NULL;
296 mtag = m_tag_next(*m, mtag)) {
297 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
298 continue;
299 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
300 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
301 continue;
302 /*
303 * Check if policy has an SA associated with it.
304 * This can happen when an SP has yet to acquire
305 * an SA; e.g. on first reference. If it occurs,
306 * then we let ipsec4_process_packet do its thing.
307 */
308 if (sp->req->sav == NULL)
309 break;
310 tdbi = (struct tdb_ident *)(mtag + 1);
311 if (tdbi->spi == sp->req->sav->spi &&
312 tdbi->proto == sp->req->sav->sah->saidx.proto &&
313 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
314 sizeof (union sockaddr_union)) == 0) {
315 /*
316 * No IPsec processing is needed, free
317 * reference to SP.
318 *
319 * NB: null pointer to avoid free at
320 * done: below.
321 */
322 KEY_FREESP(&sp), sp = NULL;
323 goto done;
324 }
325 }
326
327 /*
328 * Do delayed checksums now because we send before
329 * this is done in the normal processing path.
330 */
331 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
332 in_delayed_cksum(*m);
333 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
334 }
335#ifdef SCTP
336 if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP) {
337 struct ip *ip = mtod(*m, struct ip *);
338
339 sctp_delayed_cksum(*m, (uint32_t)(ip->ip_hl << 2));
340 (*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP;
341 }
342#endif
343
344 /* NB: callee frees mbuf */
345 *error = ipsec4_process_packet(*m, sp->req, *flags, 0);
346 if (*error == EJUSTRETURN) {
347 /*
348 * We had a SP with a level of 'use' and no SA. We
349 * will just continue to process the packet without
350 * IPsec processing and return without error.
351 */
352 *error = 0;
353 goto done;
354 }
355 /*
356 * Preserve KAME behaviour: ENOENT can be returned
357 * when an SA acquire is in progress. Don't propagate
358 * this to user-level; it confuses applications.
359 *
360 * XXX this will go away when the SADB is redone.
361 */
362 if (*error == ENOENT)
363 *error = 0;
364 goto reinjected;
365 } else { /* sp == NULL */
366
367 if (*error != 0) {
368 /*
369 * Hack: -EINVAL is used to signal that a packet
370 * should be silently discarded. This is typically
371 * because we asked key management for an SA and
372 * it was delayed (e.g. kicked up to IKE).
373 */
374 if (*error == -EINVAL)
375 *error = 0;
376 goto bad;
377 } else {
378 /* No IPsec processing for this packet. */
379 }
380 }
381done:
382 if (sp != NULL)
383 KEY_FREESP(&sp);
384 return 0;
385reinjected:
386 if (sp != NULL)
387 KEY_FREESP(&sp);
388 return -1;
389bad:
390 if (sp != NULL)
391 KEY_FREESP(&sp);
392 return 1;
393#endif /* IPSEC */
394 return 0;
395}
| 241 ro->ro_rt->rt_ifp->if_mtu;
242 mtu -= ipsechdr;
243 }
244 }
245 KEY_FREESP(&sp);
246 }
247 return mtu;
248}
249
250/*
251 *
252 * Called from ip_output().
253 * 1 = drop packet, 0 = continue processing packet,
254 * -1 = packet was reinjected and stop processing packet
255 */
256int
257ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error)
258{
259#ifdef IPSEC
260 struct secpolicy *sp = NULL;
261 struct tdb_ident *tdbi;
262 struct m_tag *mtag;
263 /*
264 * Check the security policy (SP) for the packet and, if
265 * required, do IPsec-related processing. There are two
266 * cases here; the first time a packet is sent through
267 * it will be untagged and handled by ipsec4_checkpolicy.
268 * If the packet is resubmitted to ip_output (e.g. after
269 * AH, ESP, etc. processing), there will be a tag to bypass
270 * the lookup and related policy checking.
271 */
272 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
273 if (mtag != NULL) {
274 tdbi = (struct tdb_ident *)(mtag + 1);
275 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
276 if (sp == NULL)
277 *error = -EINVAL; /* force silent drop */
278 m_tag_delete(*m, mtag);
279 } else {
280 sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
281 error, inp);
282 }
283 /*
284 * There are four return cases:
285 * sp != NULL apply IPsec policy
286 * sp == NULL, error == 0 no IPsec handling needed
287 * sp == NULL, error == -EINVAL discard packet w/o error
288 * sp == NULL, error != 0 discard packet, report error
289 */
290 if (sp != NULL) {
291 /* Loop detection, check if ipsec processing already done */
292 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
293 for (mtag = m_tag_first(*m); mtag != NULL;
294 mtag = m_tag_next(*m, mtag)) {
295 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
296 continue;
297 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
298 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
299 continue;
300 /*
301 * Check if policy has an SA associated with it.
302 * This can happen when an SP has yet to acquire
303 * an SA; e.g. on first reference. If it occurs,
304 * then we let ipsec4_process_packet do its thing.
305 */
306 if (sp->req->sav == NULL)
307 break;
308 tdbi = (struct tdb_ident *)(mtag + 1);
309 if (tdbi->spi == sp->req->sav->spi &&
310 tdbi->proto == sp->req->sav->sah->saidx.proto &&
311 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
312 sizeof (union sockaddr_union)) == 0) {
313 /*
314 * No IPsec processing is needed, free
315 * reference to SP.
316 *
317 * NB: null pointer to avoid free at
318 * done: below.
319 */
320 KEY_FREESP(&sp), sp = NULL;
321 goto done;
322 }
323 }
324
325 /*
326 * Do delayed checksums now because we send before
327 * this is done in the normal processing path.
328 */
329 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
330 in_delayed_cksum(*m);
331 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
332 }
333#ifdef SCTP
334 if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP) {
335 struct ip *ip = mtod(*m, struct ip *);
336
337 sctp_delayed_cksum(*m, (uint32_t)(ip->ip_hl << 2));
338 (*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP;
339 }
340#endif
341
342 /* NB: callee frees mbuf */
343 *error = ipsec4_process_packet(*m, sp->req, *flags, 0);
344 if (*error == EJUSTRETURN) {
345 /*
346 * We had a SP with a level of 'use' and no SA. We
347 * will just continue to process the packet without
348 * IPsec processing and return without error.
349 */
350 *error = 0;
351 goto done;
352 }
353 /*
354 * Preserve KAME behaviour: ENOENT can be returned
355 * when an SA acquire is in progress. Don't propagate
356 * this to user-level; it confuses applications.
357 *
358 * XXX this will go away when the SADB is redone.
359 */
360 if (*error == ENOENT)
361 *error = 0;
362 goto reinjected;
363 } else { /* sp == NULL */
364
365 if (*error != 0) {
366 /*
367 * Hack: -EINVAL is used to signal that a packet
368 * should be silently discarded. This is typically
369 * because we asked key management for an SA and
370 * it was delayed (e.g. kicked up to IKE).
371 */
372 if (*error == -EINVAL)
373 *error = 0;
374 goto bad;
375 } else {
376 /* No IPsec processing for this packet. */
377 }
378 }
379done:
380 if (sp != NULL)
381 KEY_FREESP(&sp);
382 return 0;
383reinjected:
384 if (sp != NULL)
385 KEY_FREESP(&sp);
386 return -1;
387bad:
388 if (sp != NULL)
389 KEY_FREESP(&sp);
390 return 1;
391#endif /* IPSEC */
392 return 0;
393}
|