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30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
34 #include "opt_inet6.h"
35 #include "opt_ipsec.h"
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
41 #include <sys/malloc.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/sysctl.h>
47 #include <sys/syslog.h>
50 #include <net/route.h>
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/in_var.h>
56 #include <netinet/ip.h>
57 #include <netinet/ip6.h>
58 #include <netinet/in_pcb.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/ip_options.h>
62 #include <machine/in_cksum.h>
65 #include <netipsec/ipsec.h>
66 #include <netipsec/ipsec6.h>
67 #include <netipsec/xform.h>
68 #include <netipsec/key.h>
70 #include <netipsec/key_debug.h>
72 #define KEYDEBUG(lev,arg)
76 #include <netinet6/ip6_ipsec.h>
77 #include <netinet6/ip6_var.h>
79 extern struct protosw inet6sw[];
84 #ifdef IPSEC_FILTERTUNNEL
85 static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1;
87 static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0;
89 #define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel)
91 SYSCTL_DECL(_net_inet6_ipsec6);
92 SYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO,
93 filtertunnel, CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0,
94 "If set filter packets from an IPsec tunnel.");
99 * Check if we have to jump over firewall processing for this packet.
100 * Called from ip6_input().
101 * 1 = jump over firewall, 0 = packet goes through firewall.
104 ip6_ipsec_filtertunnel(struct mbuf *m)
109 * Bypass packet filtering for packets previously handled by IPsec.
111 if (!V_ip6_ipsec6_filtertunnel &&
112 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
119 * Check if this packet has an active SA and needs to be dropped instead
121 * Called from ip6_input().
122 * 1 = drop packet, 0 = forward packet.
125 ip6_ipsec_fwd(struct mbuf *m)
129 struct tdb_ident *tdbi;
130 struct secpolicy *sp;
132 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
134 tdbi = (struct tdb_ident *)(mtag + 1);
135 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
137 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
138 IP_FORWARDING, &error);
140 if (sp == NULL) { /* NB: can happen if error */
141 /*XXX error stat???*/
142 DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/
147 * Check security policy against packet attributes.
149 error = ipsec_in_reject(sp, m);
152 IP6STAT_INC(ip6s_cantforward);
160 * Check if protocol type doesn't have a further header and do IPSEC
161 * decryption or reject right now. Protocols with further headers get
162 * their IPSEC treatment within the protocol specific processing.
163 * Called from ip6_input().
164 * 1 = drop packet, 0 = continue processing packet.
167 ip6_ipsec_input(struct mbuf *m, int nxt)
171 struct tdb_ident *tdbi;
172 struct secpolicy *sp;
175 * enforce IPsec policy checking if we are seeing last header.
176 * note that we do not visit this with protocols with pcb layer
177 * code - like udp/tcp/raw ip.
179 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
180 ipsec6_in_reject(m, NULL)) {
183 * Check if the packet has already had IPsec processing
184 * done. If so, then just pass it along. This tag gets
185 * set during AH, ESP, etc. input handling, before the
186 * packet is returned to the ip input queue for delivery.
188 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
190 tdbi = (struct tdb_ident *)(mtag + 1);
191 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
193 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
194 IP_FORWARDING, &error);
198 * Check security policy against packet attributes.
200 error = ipsec_in_reject(sp, m);
203 /* XXX error stat??? */
205 DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/
216 * Called from ip6_output().
217 * 1 = drop packet, 0 = continue processing packet,
218 * -1 = packet was reinjected and stop processing packet
222 ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
223 struct ifnet **ifp, struct secpolicy **sp)
226 struct tdb_ident *tdbi;
231 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
233 tdbi = (struct tdb_ident *)(mtag + 1);
234 *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
236 *error = -EINVAL; /* force silent drop */
237 m_tag_delete(*m, mtag);
239 *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
244 * There are four return cases:
245 * sp != NULL apply IPsec policy
246 * sp == NULL, error == 0 no IPsec handling needed
247 * sp == NULL, error == -EINVAL discard packet w/o error
248 * sp == NULL, error != 0 discard packet, report error
251 /* Loop detection, check if ipsec processing already done */
252 KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request"));
253 for (mtag = m_tag_first(*m); mtag != NULL;
254 mtag = m_tag_next(*m, mtag)) {
255 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
257 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
258 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
261 * Check if policy has no SA associated with it.
262 * This can happen when an SP has yet to acquire
263 * an SA; e.g. on first reference. If it occurs,
264 * then we let ipsec4_process_packet do its thing.
266 if ((*sp)->req->sav == NULL)
268 tdbi = (struct tdb_ident *)(mtag + 1);
269 if (tdbi->spi == (*sp)->req->sav->spi &&
270 tdbi->proto == (*sp)->req->sav->sah->saidx.proto &&
271 bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst,
272 sizeof (union sockaddr_union)) == 0) {
274 * No IPsec processing is needed, free
277 * NB: null pointer to avoid free at
280 KEY_FREESP(sp), *sp = NULL;
286 * Do delayed checksums now because we send before
287 * this is done in the normal processing path.
288 * For IPv6 we do delayed checksums in ip6_output.c.
291 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
293 "%s: we do not support IPv4 over IPv6", __func__));
294 in_delayed_cksum(*m);
295 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
300 * Preserve KAME behaviour: ENOENT can be returned
301 * when an SA acquire is in progress. Don't propagate
302 * this to user-level; it confuses applications.
304 * XXX this will go away when the SADB is redone.
306 if (*error == ENOENT)
309 } else { /* sp == NULL */
312 * Hack: -EINVAL is used to signal that a packet
313 * should be silently discarded. This is typically
314 * because we asked key management for an SA and
315 * it was delayed (e.g. kicked up to IKE).
317 if (*error == -EINVAL)
321 /* No IPsec processing for this packet. */
336 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
337 * Called from ip_forward().
338 * Returns MTU suggestion for ICMP needfrag reply.
341 ip6_ipsec_mtu(struct mbuf *m)
345 * If the packet is routed over IPsec tunnel, tell the
346 * originator the tunnel MTU.
347 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
351 struct secpolicy *sp = NULL;
355 sp = ipsec_getpolicybyaddr(m,
360 /* count IPsec header size */
361 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
364 * find the correct route for outer IPv4
365 * header, compute tunnel MTU.
367 if (sp->req != NULL &&
368 sp->req->sav != NULL &&
369 sp->req->sav->sah != NULL) {
370 ro = &sp->req->sav->sah->route_cache.sa_route;
371 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
373 ro->ro_rt->rt_rmx.rmx_mtu ?
374 ro->ro_rt->rt_rmx.rmx_mtu :
375 ro->ro_rt->rt_ifp->if_mtu;
382 /* XXX else case missing. */