ip6_ipsec.c revision 275710
1171133Sgnn/*- 2171133Sgnn * Copyright (c) 1982, 1986, 1988, 1993 3171133Sgnn * The Regents of the University of California. All rights reserved. 4171133Sgnn * 5171133Sgnn * Redistribution and use in source and binary forms, with or without 6171133Sgnn * modification, are permitted provided that the following conditions 7171133Sgnn * are met: 8171133Sgnn * 1. Redistributions of source code must retain the above copyright 9171133Sgnn * notice, this list of conditions and the following disclaimer. 10171133Sgnn * 2. Redistributions in binary form must reproduce the above copyright 11171133Sgnn * notice, this list of conditions and the following disclaimer in the 12171133Sgnn * documentation and/or other materials provided with the distribution. 13171133Sgnn * 4. Neither the name of the University nor the names of its contributors 14171133Sgnn * may be used to endorse or promote products derived from this software 15171133Sgnn * without specific prior written permission. 16171133Sgnn * 17171133Sgnn * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18171133Sgnn * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19171133Sgnn * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20171133Sgnn * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21171133Sgnn * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22171133Sgnn * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23171133Sgnn * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24171133Sgnn * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25171133Sgnn * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26171133Sgnn * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27171133Sgnn * SUCH DAMAGE. 28171133Sgnn */ 29171133Sgnn 30174510Sobrien#include <sys/cdefs.h> 31174510Sobrien__FBSDID("$FreeBSD: head/sys/netinet6/ip6_ipsec.c 275710 2014-12-11 18:35:34Z ae $"); 32174510Sobrien 33221129Sbz#include "opt_inet.h" 34195699Srwatson#include "opt_inet6.h" 35171133Sgnn#include "opt_ipsec.h" 36171133Sgnn 37171133Sgnn#include <sys/param.h> 38171133Sgnn#include <sys/systm.h> 39171133Sgnn#include <sys/kernel.h> 40171133Sgnn#include <sys/mac.h> 41171133Sgnn#include <sys/malloc.h> 42171133Sgnn#include <sys/mbuf.h> 43171133Sgnn#include <sys/protosw.h> 44171133Sgnn#include <sys/socket.h> 45171133Sgnn#include <sys/socketvar.h> 46171133Sgnn#include <sys/sysctl.h> 47221129Sbz#include <sys/syslog.h> 48171133Sgnn 49171133Sgnn#include <net/if.h> 50257176Sglebius#include <net/if_var.h> 51195699Srwatson#include <net/vnet.h> 52171133Sgnn 53171133Sgnn#include <netinet/in.h> 54171133Sgnn#include <netinet/in_systm.h> 55171133Sgnn#include <netinet/in_var.h> 56171133Sgnn#include <netinet/ip.h> 57180085Sjulian#include <netinet/ip6.h> 58171133Sgnn#include <netinet/in_pcb.h> 59171133Sgnn#include <netinet/ip_var.h> 60171133Sgnn#include <netinet/ip_options.h> 61171133Sgnn 62171133Sgnn#include <machine/in_cksum.h> 63171133Sgnn 64171167Sgnn#ifdef IPSEC 65171133Sgnn#include <netipsec/ipsec.h> 66171133Sgnn#include <netipsec/ipsec6.h> 67171133Sgnn#include <netipsec/xform.h> 68171133Sgnn#include <netipsec/key.h> 69171133Sgnn#ifdef IPSEC_DEBUG 70171133Sgnn#include <netipsec/key_debug.h> 71171133Sgnn#else 72171133Sgnn#define KEYDEBUG(lev,arg) 73171133Sgnn#endif 74171167Sgnn#endif /*IPSEC*/ 75171133Sgnn 76171133Sgnn#include <netinet6/ip6_ipsec.h> 77180090Sbz#include <netinet6/ip6_var.h> 78171133Sgnn 79171133Sgnnextern struct protosw inet6sw[]; 80171133Sgnn 81195699Srwatson 82195699Srwatson#ifdef INET6 83195699Srwatson#ifdef IPSEC 84195699Srwatson#ifdef IPSEC_FILTERTUNNEL 85215701Sdimstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1; 86195699Srwatson#else 87215701Sdimstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0; 88192648Sbz#endif 89195727Srwatson#define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel) 90192648Sbz 91195699SrwatsonSYSCTL_DECL(_net_inet6_ipsec6); 92274225SglebiusSYSCTL_INT(_net_inet6_ipsec6, OID_AUTO, filtertunnel, 93274225Sglebius CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0, 94195699Srwatson "If set filter packets from an IPsec tunnel."); 95195699Srwatson#endif /* IPSEC */ 96195699Srwatson#endif /* INET6 */ 97195699Srwatson 98171133Sgnn/* 99171133Sgnn * Check if we have to jump over firewall processing for this packet. 100222845Sbz * Called from ip6_input(). 101171133Sgnn * 1 = jump over firewall, 0 = packet goes through firewall. 102171133Sgnn */ 103171133Sgnnint 104171732Sbzip6_ipsec_filtertunnel(struct mbuf *m) 105171133Sgnn{ 106230442Sbz#ifdef IPSEC 107192648Sbz 108171133Sgnn /* 109222845Sbz * Bypass packet filtering for packets previously handled by IPsec. 110171133Sgnn */ 111192648Sbz if (!V_ip6_ipsec6_filtertunnel && 112192648Sbz m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 113171133Sgnn return 1; 114171133Sgnn#endif 115171133Sgnn return 0; 116171133Sgnn} 117171133Sgnn 118171133Sgnn/* 119171133Sgnn * Check if this packet has an active SA and needs to be dropped instead 120171133Sgnn * of forwarded. 121222845Sbz * Called from ip6_input(). 122171133Sgnn * 1 = drop packet, 0 = forward packet. 123171133Sgnn */ 124171133Sgnnint 125171133Sgnnip6_ipsec_fwd(struct mbuf *m) 126171133Sgnn{ 127171167Sgnn#ifdef IPSEC 128171133Sgnn struct secpolicy *sp; 129241686Sandre int error; 130171133Sgnn 131275710Sae sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, &error); 132275704Sae if (sp != NULL) { 133275704Sae /* 134275704Sae * Check security policy against packet attributes. 135275704Sae */ 136275704Sae error = ipsec_in_reject(sp, m); 137275704Sae KEY_FREESP(&sp); 138171133Sgnn } 139275704Sae if (error != 0) 140275704Sae return (1); 141171167Sgnn#endif /* IPSEC */ 142275704Sae return (0); 143171133Sgnn} 144171133Sgnn 145171133Sgnn/* 146171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 147171133Sgnn * decryption or reject right now. Protocols with further headers get 148171133Sgnn * their IPSEC treatment within the protocol specific processing. 149222845Sbz * Called from ip6_input(). 150171133Sgnn * 1 = drop packet, 0 = continue processing packet. 151171133Sgnn */ 152171133Sgnnint 153171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 154171133Sgnn{ 155171167Sgnn#ifdef IPSEC 156171133Sgnn struct secpolicy *sp; 157241686Sandre int error; 158171133Sgnn /* 159171133Sgnn * enforce IPsec policy checking if we are seeing last header. 160171133Sgnn * note that we do not visit this with protocols with pcb layer 161171133Sgnn * code - like udp/tcp/raw ip. 162171133Sgnn */ 163171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 164171133Sgnn ipsec6_in_reject(m, NULL)) { 165275710Sae sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, &error); 166171133Sgnn if (sp != NULL) { 167171133Sgnn /* 168171133Sgnn * Check security policy against packet attributes. 169171133Sgnn */ 170171133Sgnn error = ipsec_in_reject(sp, m); 171171133Sgnn KEY_FREESP(&sp); 172171133Sgnn } else { 173171133Sgnn /* XXX error stat??? */ 174171133Sgnn error = EINVAL; 175222845Sbz DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/ 176171133Sgnn } 177275703Sae if (error != 0) 178275703Sae return (1); 179171133Sgnn } 180171167Sgnn#endif /* IPSEC */ 181275703Sae return (0); 182171133Sgnn} 183171133Sgnn 184171133Sgnn/* 185171133Sgnn * Called from ip6_output(). 186171133Sgnn * 1 = drop packet, 0 = continue processing packet, 187171260Sdelphij * -1 = packet was reinjected and stop processing packet 188171260Sdelphij */ 189171133Sgnn 190171133Sgnnint 191275710Saeip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *error) 192171133Sgnn{ 193171167Sgnn#ifdef IPSEC 194275702Sae struct secpolicy *sp; 195171133Sgnn 196171133Sgnn /* 197275702Sae * Check the security policy (SP) for the packet and, if 198275702Sae * required, do IPsec-related processing. There are two 199275702Sae * cases here; the first time a packet is sent through 200275702Sae * it will be untagged and handled by ipsec4_checkpolicy. 201275702Sae * If the packet is resubmitted to ip6_output (e.g. after 202275702Sae * AH, ESP, etc. processing), there will be a tag to bypass 203275702Sae * the lookup and related policy checking. 204275702Sae */ 205275702Sae if (m_tag_find(*m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) { 206275702Sae *error = 0; 207275702Sae return (0); 208275702Sae } 209275710Sae sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, error, inp); 210275702Sae /* 211171133Sgnn * There are four return cases: 212171260Sdelphij * sp != NULL apply IPsec policy 213171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 214171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 215171133Sgnn * sp == NULL, error != 0 discard packet, report error 216171133Sgnn */ 217266800Svanhu if (sp != NULL) { 218171133Sgnn /* 219171133Sgnn * Do delayed checksums now because we send before 220171133Sgnn * this is done in the normal processing path. 221171133Sgnn */ 222238935Sbz#ifdef INET 223171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 224171133Sgnn in_delayed_cksum(*m); 225171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 226171133Sgnn } 227238935Sbz#endif 228266800Svanhu if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 229266800Svanhu in6_delayed_cksum(*m, (*m)->m_pkthdr.len - sizeof(struct ip6_hdr), 230266800Svanhu sizeof(struct ip6_hdr)); 231266800Svanhu (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 232266800Svanhu } 233266800Svanhu#ifdef SCTP 234266800Svanhu if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 235266800Svanhu sctp_delayed_cksum(*m, sizeof(struct ip6_hdr)); 236266800Svanhu (*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 237266800Svanhu } 238266800Svanhu#endif 239171133Sgnn 240266800Svanhu /* NB: callee frees mbuf */ 241266800Svanhu *error = ipsec6_process_packet(*m, sp->req); 242266800Svanhu 243266800Svanhu if (*error == EJUSTRETURN) { 244266800Svanhu /* 245266800Svanhu * We had a SP with a level of 'use' and no SA. We 246266800Svanhu * will just continue to process the packet without 247266800Svanhu * IPsec processing. 248266800Svanhu */ 249266800Svanhu *error = 0; 250266800Svanhu goto done; 251266800Svanhu } 252266800Svanhu 253171133Sgnn /* 254171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 255171133Sgnn * when an SA acquire is in progress. Don't propagate 256171133Sgnn * this to user-level; it confuses applications. 257171133Sgnn * 258171133Sgnn * XXX this will go away when the SADB is redone. 259171133Sgnn */ 260171133Sgnn if (*error == ENOENT) 261171133Sgnn *error = 0; 262266800Svanhu goto reinjected; 263171133Sgnn } else { /* sp == NULL */ 264171133Sgnn if (*error != 0) { 265171133Sgnn /* 266171133Sgnn * Hack: -EINVAL is used to signal that a packet 267171133Sgnn * should be silently discarded. This is typically 268171133Sgnn * because we asked key management for an SA and 269171133Sgnn * it was delayed (e.g. kicked up to IKE). 270171133Sgnn */ 271171133Sgnn if (*error == -EINVAL) 272171133Sgnn *error = 0; 273171133Sgnn goto bad; 274171133Sgnn } 275275702Sae /* No IPsec processing for this packet. */ 276171133Sgnn } 277171133Sgnndone: 278266800Svanhu if (sp != NULL) 279266800Svanhu KEY_FREESP(&sp); 280171133Sgnn return 0; 281266800Svanhureinjected: 282266800Svanhu if (sp != NULL) 283266800Svanhu KEY_FREESP(&sp); 284171133Sgnn return -1; 285171133Sgnnbad: 286266800Svanhu if (sp != NULL) 287266800Svanhu KEY_FREESP(&sp); 288171133Sgnn return 1; 289171167Sgnn#endif /* IPSEC */ 290171133Sgnn return 0; 291171133Sgnn} 292171133Sgnn 293177166Sbz#if 0 294171133Sgnn/* 295171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 296171133Sgnn * Called from ip_forward(). 297171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 298171133Sgnn */ 299171133Sgnnint 300171133Sgnnip6_ipsec_mtu(struct mbuf *m) 301171133Sgnn{ 302171133Sgnn int mtu = 0; 303171133Sgnn /* 304171133Sgnn * If the packet is routed over IPsec tunnel, tell the 305171133Sgnn * originator the tunnel MTU. 306171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 307171133Sgnn * XXX quickhack!!! 308171133Sgnn */ 309177166Sbz#ifdef IPSEC 310171133Sgnn struct secpolicy *sp = NULL; 311171133Sgnn int ipsecerror; 312171133Sgnn int ipsechdr; 313171133Sgnn struct route *ro; 314171133Sgnn sp = ipsec_getpolicybyaddr(m, 315171133Sgnn IPSEC_DIR_OUTBOUND, 316171133Sgnn IP_FORWARDING, 317171133Sgnn &ipsecerror); 318171133Sgnn if (sp != NULL) { 319171133Sgnn /* count IPsec header size */ 320188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 321171133Sgnn 322171133Sgnn /* 323171133Sgnn * find the correct route for outer IPv4 324171133Sgnn * header, compute tunnel MTU. 325171133Sgnn */ 326171133Sgnn if (sp->req != NULL && 327171133Sgnn sp->req->sav != NULL && 328171133Sgnn sp->req->sav->sah != NULL) { 329214250Sbz ro = &sp->req->sav->sah->route_cache.sa_route; 330171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 331262763Sglebius mtu = ro->ro_rt->rt_mtu ? ro->ro_rt->rt_mtu : 332171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 333171133Sgnn mtu -= ipsechdr; 334171133Sgnn } 335171133Sgnn } 336171133Sgnn KEY_FREESP(&sp); 337177166Sbz } 338171167Sgnn#endif /* IPSEC */ 339177166Sbz /* XXX else case missing. */ 340171133Sgnn return mtu; 341171133Sgnn} 342177166Sbz#endif 343