2 * Copyright (c) 1982, 1986, 1988, 1993
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30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include "opt_inet6.h"
34 #include "opt_ipsec.h"
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
40 #include <sys/malloc.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/sysctl.h>
48 #include <net/route.h>
51 #include <netinet/in.h>
52 #include <netinet/in_systm.h>
53 #include <netinet/in_var.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip6.h>
56 #include <netinet/in_pcb.h>
57 #include <netinet/ip_var.h>
58 #include <netinet/ip_options.h>
60 #include <machine/in_cksum.h>
63 #include <netipsec/ipsec.h>
64 #include <netipsec/ipsec6.h>
65 #include <netipsec/xform.h>
66 #include <netipsec/key.h>
68 #include <netipsec/key_debug.h>
70 #define KEYDEBUG(lev,arg)
74 #include <netinet6/ip6_ipsec.h>
75 #include <netinet6/ip6_var.h>
77 extern struct protosw inet6sw[];
82 #ifdef IPSEC_FILTERTUNNEL
83 static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1;
85 static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0;
87 #define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel)
89 SYSCTL_DECL(_net_inet6_ipsec6);
90 SYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO,
91 filtertunnel, CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0,
92 "If set filter packets from an IPsec tunnel.");
97 * Check if we have to jump over firewall processing for this packet.
98 * Called from ip_input().
99 * 1 = jump over firewall, 0 = packet goes through firewall.
102 ip6_ipsec_filtertunnel(struct mbuf *m)
107 * Bypass packet filtering for packets from a tunnel.
109 if (!V_ip6_ipsec6_filtertunnel &&
110 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
117 * Check if this packet has an active SA and needs to be dropped instead
119 * Called from ip_input().
120 * 1 = drop packet, 0 = forward packet.
123 ip6_ipsec_fwd(struct mbuf *m)
127 struct tdb_ident *tdbi;
128 struct secpolicy *sp;
130 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
133 tdbi = (struct tdb_ident *)(mtag + 1);
134 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
136 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
137 IP_FORWARDING, &error);
139 if (sp == NULL) { /* NB: can happen if error */
141 /*XXX error stat???*/
142 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
147 * Check security policy against packet attributes.
149 error = ipsec_in_reject(sp, m);
153 V_ip6stat.ip6s_cantforward++;
161 * Check if protocol type doesn't have a further header and do IPSEC
162 * decryption or reject right now. Protocols with further headers get
163 * their IPSEC treatment within the protocol specific processing.
164 * Called from ip_input().
165 * 1 = drop packet, 0 = continue processing packet.
168 ip6_ipsec_input(struct mbuf *m, int nxt)
172 struct tdb_ident *tdbi;
173 struct secpolicy *sp;
176 * enforce IPsec policy checking if we are seeing last header.
177 * note that we do not visit this with protocols with pcb layer
178 * code - like udp/tcp/raw ip.
180 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
181 ipsec6_in_reject(m, NULL)) {
184 * Check if the packet has already had IPsec processing
185 * done. If so, then just pass it along. This tag gets
186 * set during AH, ESP, etc. input handling, before the
187 * packet is returned to the ip input queue for delivery.
189 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
192 tdbi = (struct tdb_ident *)(mtag + 1);
193 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
195 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
196 IP_FORWARDING, &error);
200 * Check security policy against packet attributes.
202 error = ipsec_in_reject(sp, m);
205 /* XXX error stat??? */
207 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
219 * Called from ip6_output().
220 * 1 = drop packet, 0 = continue processing packet,
221 * -1 = packet was reinjected and stop processing packet
225 ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
226 struct ifnet **ifp, struct secpolicy **sp)
229 struct tdb_ident *tdbi;
234 mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
236 tdbi = (struct tdb_ident *)(mtag + 1);
237 *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
239 *error = -EINVAL; /* force silent drop */
240 m_tag_delete(*m, mtag);
242 *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
247 * There are four return cases:
248 * sp != NULL apply IPsec policy
249 * sp == NULL, error == 0 no IPsec handling needed
250 * sp == NULL, error == -EINVAL discard packet w/o error
251 * sp == NULL, error != 0 discard packet, report error
254 /* Loop detection, check if ipsec processing already done */
255 KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request"));
256 for (mtag = m_tag_first(*m); mtag != NULL;
257 mtag = m_tag_next(*m, mtag)) {
258 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
260 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
261 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
264 * Check if policy has an SA associated with it.
265 * This can happen when an SP has yet to acquire
266 * an SA; e.g. on first reference. If it occurs,
267 * then we let ipsec4_process_packet do its thing.
269 if ((*sp)->req->sav == NULL)
271 tdbi = (struct tdb_ident *)(mtag + 1);
272 if (tdbi->spi == (*sp)->req->sav->spi &&
273 tdbi->proto == (*sp)->req->sav->sah->saidx.proto &&
274 bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst,
275 sizeof (union sockaddr_union)) == 0) {
277 * No IPsec processing is needed, free
280 * NB: null pointer to avoid free at
283 KEY_FREESP(sp), *sp = NULL;
290 * Do delayed checksums now because we send before
291 * this is done in the normal processing path.
293 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
294 in_delayed_cksum(*m);
295 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
299 * Preserve KAME behaviour: ENOENT can be returned
300 * when an SA acquire is in progress. Don't propagate
301 * this to user-level; it confuses applications.
303 * XXX this will go away when the SADB is redone.
305 if (*error == ENOENT)
308 } else { /* sp == NULL */
311 * Hack: -EINVAL is used to signal that a packet
312 * should be silently discarded. This is typically
313 * because we asked key management for an SA and
314 * it was delayed (e.g. kicked up to IKE).
316 if (*error == -EINVAL)
320 /* No IPsec processing for this packet. */
335 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
336 * Called from ip_forward().
337 * Returns MTU suggestion for ICMP needfrag reply.
340 ip6_ipsec_mtu(struct mbuf *m)
344 * If the packet is routed over IPsec tunnel, tell the
345 * originator the tunnel MTU.
346 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
350 struct secpolicy *sp = NULL;
354 sp = ipsec_getpolicybyaddr(m,
359 /* count IPsec header size */
360 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
363 * find the correct route for outer IPv4
364 * header, compute tunnel MTU.
366 if (sp->req != NULL &&
367 sp->req->sav != NULL &&
368 sp->req->sav->sah != NULL) {
369 ro = &sp->req->sav->sah->route_cache.sa_route;
370 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
372 ro->ro_rt->rt_rmx.rmx_mtu ?
373 ro->ro_rt->rt_rmx.rmx_mtu :
374 ro->ro_rt->rt_ifp->if_mtu;
381 /* XXX else case missing. */