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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);
135 tdbi = (struct tdb_ident *)(mtag + 1);
136 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
138 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
139 IP_FORWARDING, &error);
141 if (sp == NULL) { /* NB: can happen if error */
143 /*XXX error stat???*/
144 DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/
149 * Check security policy against packet attributes.
151 error = ipsec_in_reject(sp, m);
155 IP6STAT_INC(ip6s_cantforward);
163 * Check if protocol type doesn't have a further header and do IPSEC
164 * decryption or reject right now. Protocols with further headers get
165 * their IPSEC treatment within the protocol specific processing.
166 * Called from ip6_input().
167 * 1 = drop packet, 0 = continue processing packet.
170 ip6_ipsec_input(struct mbuf *m, int nxt)
174 struct tdb_ident *tdbi;
175 struct secpolicy *sp;
178 * enforce IPsec policy checking if we are seeing last header.
179 * note that we do not visit this with protocols with pcb layer
180 * code - like udp/tcp/raw ip.
182 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
183 ipsec6_in_reject(m, NULL)) {
186 * Check if the packet has already had IPsec processing
187 * done. If so, then just pass it along. This tag gets
188 * set during AH, ESP, etc. input handling, before the
189 * packet is returned to the ip input queue for delivery.
191 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
194 tdbi = (struct tdb_ident *)(mtag + 1);
195 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
197 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
198 IP_FORWARDING, &error);
202 * Check security policy against packet attributes.
204 error = ipsec_in_reject(sp, m);
207 /* XXX error stat??? */
209 DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/
221 * Called from ip6_output().
222 * 1 = drop packet, 0 = continue processing packet,
223 * -1 = packet was reinjected and stop processing packet
227 ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
228 struct ifnet **ifp, struct secpolicy **sp)
231 struct tdb_ident *tdbi;
236 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
238 tdbi = (struct tdb_ident *)(mtag + 1);
239 *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
241 *error = -EINVAL; /* force silent drop */
242 m_tag_delete(*m, mtag);
244 *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
249 * There are four return cases:
250 * sp != NULL apply IPsec policy
251 * sp == NULL, error == 0 no IPsec handling needed
252 * sp == NULL, error == -EINVAL discard packet w/o error
253 * sp == NULL, error != 0 discard packet, report error
256 /* Loop detection, check if ipsec processing already done */
257 KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request"));
258 for (mtag = m_tag_first(*m); mtag != NULL;
259 mtag = m_tag_next(*m, mtag)) {
260 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
262 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
263 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
266 * Check if policy has no SA associated with it.
267 * This can happen when an SP has yet to acquire
268 * an SA; e.g. on first reference. If it occurs,
269 * then we let ipsec4_process_packet do its thing.
271 if ((*sp)->req->sav == NULL)
273 tdbi = (struct tdb_ident *)(mtag + 1);
274 if (tdbi->spi == (*sp)->req->sav->spi &&
275 tdbi->proto == (*sp)->req->sav->sah->saidx.proto &&
276 bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst,
277 sizeof (union sockaddr_union)) == 0) {
279 * No IPsec processing is needed, free
282 * NB: null pointer to avoid free at
285 KEY_FREESP(sp), *sp = NULL;
292 * Do delayed checksums now because we send before
293 * this is done in the normal processing path.
294 * For IPv6 we do delayed checksums in ip6_output.c.
297 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
299 "%s: we do not support IPv4 over IPv6", __func__));
300 in_delayed_cksum(*m);
301 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
306 * Preserve KAME behaviour: ENOENT can be returned
307 * when an SA acquire is in progress. Don't propagate
308 * this to user-level; it confuses applications.
310 * XXX this will go away when the SADB is redone.
312 if (*error == ENOENT)
315 } else { /* sp == NULL */
318 * Hack: -EINVAL is used to signal that a packet
319 * should be silently discarded. This is typically
320 * because we asked key management for an SA and
321 * it was delayed (e.g. kicked up to IKE).
323 if (*error == -EINVAL)
327 /* No IPsec processing for this packet. */
342 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
343 * Called from ip_forward().
344 * Returns MTU suggestion for ICMP needfrag reply.
347 ip6_ipsec_mtu(struct mbuf *m)
351 * If the packet is routed over IPsec tunnel, tell the
352 * originator the tunnel MTU.
353 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
357 struct secpolicy *sp = NULL;
361 sp = ipsec_getpolicybyaddr(m,
366 /* count IPsec header size */
367 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
370 * find the correct route for outer IPv4
371 * header, compute tunnel MTU.
373 if (sp->req != NULL &&
374 sp->req->sav != NULL &&
375 sp->req->sav->sah != NULL) {
376 ro = &sp->req->sav->sah->route_cache.sa_route;
377 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
379 ro->ro_rt->rt_rmx.rmx_mtu ?
380 ro->ro_rt->rt_rmx.rmx_mtu :
381 ro->ro_rt->rt_ifp->if_mtu;
388 /* XXX else case missing. */