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30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
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/if_var.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 <netinet/sctp_crc32.h>
65 #include <machine/in_cksum.h>
67 #include <netipsec/ipsec.h>
68 #include <netipsec/ipsec6.h>
69 #include <netipsec/xform.h>
70 #include <netipsec/key.h>
72 #include <netipsec/key_debug.h>
74 #define KEYDEBUG(lev,arg)
77 #include <netinet6/ip6_ipsec.h>
78 #include <netinet6/ip6_var.h>
80 extern struct protosw inet6sw[];
82 static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0;
83 #define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel)
85 SYSCTL_DECL(_net_inet6_ipsec6);
86 SYSCTL_INT(_net_inet6_ipsec6, OID_AUTO, filtertunnel,
87 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0,
88 "If set filter packets from an IPsec tunnel.");
91 * Check if we have to jump over firewall processing for this packet.
92 * Called from ip6_input().
93 * 1 = jump over firewall, 0 = packet goes through firewall.
96 ip6_ipsec_filtertunnel(struct mbuf *m)
100 * Bypass packet filtering for packets previously handled by IPsec.
102 if (!V_ip6_ipsec6_filtertunnel &&
103 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
109 * Check if this packet has an active SA and needs to be dropped instead
111 * Called from ip6_forward().
112 * 1 = drop packet, 0 = forward packet.
115 ip6_ipsec_fwd(struct mbuf *m)
118 return (ipsec6_in_reject(m, NULL));
122 * Check if protocol type doesn't have a further header and do IPSEC
123 * decryption or reject right now. Protocols with further headers get
124 * their IPSEC treatment within the protocol specific processing.
125 * Called from ip6_input().
126 * 1 = drop packet, 0 = continue processing packet.
129 ip6_ipsec_input(struct mbuf *m, int nxt)
133 * enforce IPsec policy checking if we are seeing last header.
134 * note that we do not visit this with protocols with pcb layer
135 * code - like udp/tcp/raw ip.
137 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0)
138 return (ipsec6_in_reject(m, NULL));
143 * Called from ip6_output().
144 * 1 = drop packet, 0 = continue processing packet,
145 * -1 = packet was reinjected and stop processing packet
149 ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *error)
151 struct secpolicy *sp;
154 * Check the security policy (SP) for the packet and, if
155 * required, do IPsec-related processing. There are two
156 * cases here; the first time a packet is sent through
157 * it will be untagged and handled by ipsec4_checkpolicy.
158 * If the packet is resubmitted to ip6_output (e.g. after
159 * AH, ESP, etc. processing), there will be a tag to bypass
160 * the lookup and related policy checking.
162 if (m_tag_find(*m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) {
166 sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, error, inp);
168 * There are four return cases:
169 * sp != NULL apply IPsec policy
170 * sp == NULL, error == 0 no IPsec handling needed
171 * sp == NULL, error == -EINVAL discard packet w/o error
172 * sp == NULL, error != 0 discard packet, report error
176 * Do delayed checksums now because we send before
177 * this is done in the normal processing path.
180 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
181 in_delayed_cksum(*m);
182 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
185 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
186 in6_delayed_cksum(*m, (*m)->m_pkthdr.len - sizeof(struct ip6_hdr),
187 sizeof(struct ip6_hdr));
188 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
191 if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
192 sctp_delayed_cksum(*m, sizeof(struct ip6_hdr));
193 (*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
197 /* NB: callee frees mbuf */
198 *error = ipsec6_process_packet(*m, sp->req);
200 if (*error == EJUSTRETURN) {
202 * We had a SP with a level of 'use' and no SA. We
203 * will just continue to process the packet without
211 * Preserve KAME behaviour: ENOENT can be returned
212 * when an SA acquire is in progress. Don't propagate
213 * this to user-level; it confuses applications.
215 * XXX this will go away when the SADB is redone.
217 if (*error == ENOENT)
220 } else { /* sp == NULL */
223 * Hack: -EINVAL is used to signal that a packet
224 * should be silently discarded. This is typically
225 * because we asked key management for an SA and
226 * it was delayed (e.g. kicked up to IKE).
228 if (*error == -EINVAL)
232 /* No IPsec processing for this packet. */
246 * Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
247 * Called from ip_forward().
248 * Returns MTU suggestion for ICMP needfrag reply.
251 ip6_ipsec_mtu(struct mbuf *m)
255 * If the packet is routed over IPsec tunnel, tell the
256 * originator the tunnel MTU.
257 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
261 struct secpolicy *sp = NULL;
265 sp = ipsec_getpolicybyaddr(m,
270 /* count IPsec header size */
271 ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL);
274 * find the correct route for outer IPv4
275 * header, compute tunnel MTU.
277 if (sp->req != NULL &&
278 sp->req->sav != NULL &&
279 sp->req->sav->sah != NULL) {
280 ro = &sp->req->sav->sah->route_cache.sa_route;
281 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
282 mtu = ro->ro_rt->rt_mtu ? ro->ro_rt->rt_mtu :
283 ro->ro_rt->rt_ifp->if_mtu;
290 /* XXX else case missing. */