ip6_ipsec.c revision 266800
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 266800 2014-05-28 12:45:27Z vanhu $"); 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> 51171133Sgnn#include <net/route.h> 52195699Srwatson#include <net/vnet.h> 53171133Sgnn 54171133Sgnn#include <netinet/in.h> 55171133Sgnn#include <netinet/in_systm.h> 56171133Sgnn#include <netinet/in_var.h> 57171133Sgnn#include <netinet/ip.h> 58180085Sjulian#include <netinet/ip6.h> 59171133Sgnn#include <netinet/in_pcb.h> 60171133Sgnn#include <netinet/ip_var.h> 61171133Sgnn#include <netinet/ip_options.h> 62171133Sgnn 63171133Sgnn#include <machine/in_cksum.h> 64171133Sgnn 65171167Sgnn#ifdef IPSEC 66171133Sgnn#include <netipsec/ipsec.h> 67171133Sgnn#include <netipsec/ipsec6.h> 68171133Sgnn#include <netipsec/xform.h> 69171133Sgnn#include <netipsec/key.h> 70171133Sgnn#ifdef IPSEC_DEBUG 71171133Sgnn#include <netipsec/key_debug.h> 72171133Sgnn#else 73171133Sgnn#define KEYDEBUG(lev,arg) 74171133Sgnn#endif 75171167Sgnn#endif /*IPSEC*/ 76171133Sgnn 77171133Sgnn#include <netinet6/ip6_ipsec.h> 78180090Sbz#include <netinet6/ip6_var.h> 79171133Sgnn 80171133Sgnnextern struct protosw inet6sw[]; 81171133Sgnn 82195699Srwatson 83195699Srwatson#ifdef INET6 84195699Srwatson#ifdef IPSEC 85195699Srwatson#ifdef IPSEC_FILTERTUNNEL 86215701Sdimstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1; 87195699Srwatson#else 88215701Sdimstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0; 89192648Sbz#endif 90195727Srwatson#define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel) 91192648Sbz 92195699SrwatsonSYSCTL_DECL(_net_inet6_ipsec6); 93195699SrwatsonSYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO, 94195699Srwatson filtertunnel, CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0, 95195699Srwatson "If set filter packets from an IPsec tunnel."); 96195699Srwatson#endif /* IPSEC */ 97195699Srwatson#endif /* INET6 */ 98195699Srwatson 99171133Sgnn/* 100171133Sgnn * Check if we have to jump over firewall processing for this packet. 101222845Sbz * Called from ip6_input(). 102171133Sgnn * 1 = jump over firewall, 0 = packet goes through firewall. 103171133Sgnn */ 104171133Sgnnint 105171732Sbzip6_ipsec_filtertunnel(struct mbuf *m) 106171133Sgnn{ 107230442Sbz#ifdef IPSEC 108192648Sbz 109171133Sgnn /* 110222845Sbz * Bypass packet filtering for packets previously handled by IPsec. 111171133Sgnn */ 112192648Sbz if (!V_ip6_ipsec6_filtertunnel && 113192648Sbz m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 114171133Sgnn return 1; 115171133Sgnn#endif 116171133Sgnn return 0; 117171133Sgnn} 118171133Sgnn 119171133Sgnn/* 120171133Sgnn * Check if this packet has an active SA and needs to be dropped instead 121171133Sgnn * of forwarded. 122222845Sbz * Called from ip6_input(). 123171133Sgnn * 1 = drop packet, 0 = forward packet. 124171133Sgnn */ 125171133Sgnnint 126171133Sgnnip6_ipsec_fwd(struct mbuf *m) 127171133Sgnn{ 128171167Sgnn#ifdef IPSEC 129171133Sgnn struct m_tag *mtag; 130171133Sgnn struct tdb_ident *tdbi; 131171133Sgnn struct secpolicy *sp; 132241686Sandre int error; 133171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 134171133Sgnn if (mtag != NULL) { 135171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 136171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 137171133Sgnn } else { 138171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 139171260Sdelphij IP_FORWARDING, &error); 140171133Sgnn } 141171133Sgnn if (sp == NULL) { /* NB: can happen if error */ 142171133Sgnn /*XXX error stat???*/ 143222845Sbz DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/ 144171133Sgnn return 1; 145171133Sgnn } 146171133Sgnn 147171133Sgnn /* 148171133Sgnn * Check security policy against packet attributes. 149171133Sgnn */ 150171133Sgnn error = ipsec_in_reject(sp, m); 151171133Sgnn KEY_FREESP(&sp); 152171133Sgnn if (error) { 153249294Sae IP6STAT_INC(ip6s_cantforward); 154171133Sgnn return 1; 155171133Sgnn } 156171167Sgnn#endif /* IPSEC */ 157171133Sgnn return 0; 158171133Sgnn} 159171133Sgnn 160171133Sgnn/* 161171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 162171133Sgnn * decryption or reject right now. Protocols with further headers get 163171133Sgnn * their IPSEC treatment within the protocol specific processing. 164222845Sbz * Called from ip6_input(). 165171133Sgnn * 1 = drop packet, 0 = continue processing packet. 166171133Sgnn */ 167171133Sgnnint 168171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 169171133Sgnn{ 170171167Sgnn#ifdef IPSEC 171171133Sgnn struct m_tag *mtag; 172171133Sgnn struct tdb_ident *tdbi; 173171133Sgnn struct secpolicy *sp; 174241686Sandre int error; 175171133Sgnn /* 176171133Sgnn * enforce IPsec policy checking if we are seeing last header. 177171133Sgnn * note that we do not visit this with protocols with pcb layer 178171133Sgnn * code - like udp/tcp/raw ip. 179171133Sgnn */ 180171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 181171133Sgnn ipsec6_in_reject(m, NULL)) { 182171133Sgnn 183171133Sgnn /* 184171133Sgnn * Check if the packet has already had IPsec processing 185171133Sgnn * done. If so, then just pass it along. This tag gets 186171133Sgnn * set during AH, ESP, etc. input handling, before the 187171133Sgnn * packet is returned to the ip input queue for delivery. 188171260Sdelphij */ 189171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 190171133Sgnn if (mtag != NULL) { 191171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 192171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 193171133Sgnn } else { 194171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 195171260Sdelphij IP_FORWARDING, &error); 196171133Sgnn } 197171133Sgnn if (sp != NULL) { 198171133Sgnn /* 199171133Sgnn * Check security policy against packet attributes. 200171133Sgnn */ 201171133Sgnn error = ipsec_in_reject(sp, m); 202171133Sgnn KEY_FREESP(&sp); 203171133Sgnn } else { 204171133Sgnn /* XXX error stat??? */ 205171133Sgnn error = EINVAL; 206222845Sbz DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/ 207171133Sgnn return 1; 208171133Sgnn } 209171133Sgnn if (error) 210171133Sgnn return 1; 211171133Sgnn } 212171167Sgnn#endif /* IPSEC */ 213171133Sgnn return 0; 214171133Sgnn} 215171133Sgnn 216171133Sgnn/* 217171133Sgnn * Called from ip6_output(). 218171133Sgnn * 1 = drop packet, 0 = continue processing packet, 219171260Sdelphij * -1 = packet was reinjected and stop processing packet 220171260Sdelphij */ 221171133Sgnn 222171133Sgnnint 223171133Sgnnip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error, 224266800Svanhu struct ifnet **ifp) 225171133Sgnn{ 226171167Sgnn#ifdef IPSEC 227266800Svanhu struct secpolicy *sp = NULL; 228171133Sgnn struct tdb_ident *tdbi; 229171133Sgnn struct m_tag *mtag; 230171237Speter /* XXX int s; */ 231171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 232171133Sgnn if (mtag != NULL) { 233171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 234266800Svanhu sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 235266800Svanhu if (sp == NULL) 236171133Sgnn *error = -EINVAL; /* force silent drop */ 237171133Sgnn m_tag_delete(*m, mtag); 238171133Sgnn } else { 239266800Svanhu sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags, 240171133Sgnn error, inp); 241171133Sgnn } 242171133Sgnn 243171133Sgnn /* 244171133Sgnn * There are four return cases: 245171260Sdelphij * sp != NULL apply IPsec policy 246171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 247171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 248171133Sgnn * sp == NULL, error != 0 discard packet, report error 249171133Sgnn */ 250266800Svanhu if (sp != NULL) { 251171133Sgnn /* Loop detection, check if ipsec processing already done */ 252266800Svanhu KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 253171133Sgnn for (mtag = m_tag_first(*m); mtag != NULL; 254171133Sgnn mtag = m_tag_next(*m, mtag)) { 255171133Sgnn if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 256171133Sgnn continue; 257171133Sgnn if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 258171133Sgnn mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 259171133Sgnn continue; 260171133Sgnn /* 261238877Sbz * Check if policy has no SA associated with it. 262171133Sgnn * This can happen when an SP has yet to acquire 263171133Sgnn * an SA; e.g. on first reference. If it occurs, 264171133Sgnn * then we let ipsec4_process_packet do its thing. 265171133Sgnn */ 266266800Svanhu if (sp->req->sav == NULL) 267171133Sgnn break; 268171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 269266800Svanhu if (tdbi->spi == sp->req->sav->spi && 270266800Svanhu tdbi->proto == sp->req->sav->sah->saidx.proto && 271266800Svanhu bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 272171133Sgnn sizeof (union sockaddr_union)) == 0) { 273171133Sgnn /* 274171133Sgnn * No IPsec processing is needed, free 275171133Sgnn * reference to SP. 276171133Sgnn * 277171133Sgnn * NB: null pointer to avoid free at 278171133Sgnn * done: below. 279171133Sgnn */ 280266800Svanhu KEY_FREESP(&sp), sp = NULL; 281171133Sgnn goto done; 282171133Sgnn } 283171133Sgnn } 284171133Sgnn 285171133Sgnn /* 286171133Sgnn * Do delayed checksums now because we send before 287171133Sgnn * this is done in the normal processing path. 288171133Sgnn */ 289238935Sbz#ifdef INET 290171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 291171133Sgnn in_delayed_cksum(*m); 292171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 293171133Sgnn } 294238935Sbz#endif 295266800Svanhu if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 296266800Svanhu in6_delayed_cksum(*m, (*m)->m_pkthdr.len - sizeof(struct ip6_hdr), 297266800Svanhu sizeof(struct ip6_hdr)); 298266800Svanhu (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 299266800Svanhu } 300266800Svanhu#ifdef SCTP 301266800Svanhu if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 302266800Svanhu sctp_delayed_cksum(*m, sizeof(struct ip6_hdr)); 303266800Svanhu (*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 304266800Svanhu } 305266800Svanhu#endif 306171133Sgnn 307266800Svanhu /* NB: callee frees mbuf */ 308266800Svanhu *error = ipsec6_process_packet(*m, sp->req); 309266800Svanhu 310266800Svanhu if (*error == EJUSTRETURN) { 311266800Svanhu /* 312266800Svanhu * We had a SP with a level of 'use' and no SA. We 313266800Svanhu * will just continue to process the packet without 314266800Svanhu * IPsec processing. 315266800Svanhu */ 316266800Svanhu *error = 0; 317266800Svanhu goto done; 318266800Svanhu } 319266800Svanhu 320171133Sgnn /* 321171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 322171133Sgnn * when an SA acquire is in progress. Don't propagate 323171133Sgnn * this to user-level; it confuses applications. 324171133Sgnn * 325171133Sgnn * XXX this will go away when the SADB is redone. 326171133Sgnn */ 327171133Sgnn if (*error == ENOENT) 328171133Sgnn *error = 0; 329266800Svanhu goto reinjected; 330171133Sgnn } else { /* sp == NULL */ 331171133Sgnn if (*error != 0) { 332171133Sgnn /* 333171133Sgnn * Hack: -EINVAL is used to signal that a packet 334171133Sgnn * should be silently discarded. This is typically 335171133Sgnn * because we asked key management for an SA and 336171133Sgnn * it was delayed (e.g. kicked up to IKE). 337171133Sgnn */ 338171133Sgnn if (*error == -EINVAL) 339171133Sgnn *error = 0; 340171133Sgnn goto bad; 341171133Sgnn } else { 342171133Sgnn /* No IPsec processing for this packet. */ 343171133Sgnn } 344171133Sgnn } 345171133Sgnndone: 346266800Svanhu if (sp != NULL) 347266800Svanhu KEY_FREESP(&sp); 348171133Sgnn return 0; 349266800Svanhureinjected: 350266800Svanhu if (sp != NULL) 351266800Svanhu KEY_FREESP(&sp); 352171133Sgnn return -1; 353171133Sgnnbad: 354266800Svanhu if (sp != NULL) 355266800Svanhu KEY_FREESP(&sp); 356171133Sgnn return 1; 357171167Sgnn#endif /* IPSEC */ 358171133Sgnn return 0; 359171133Sgnn} 360171133Sgnn 361177166Sbz#if 0 362171133Sgnn/* 363171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 364171133Sgnn * Called from ip_forward(). 365171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 366171133Sgnn */ 367171133Sgnnint 368171133Sgnnip6_ipsec_mtu(struct mbuf *m) 369171133Sgnn{ 370171133Sgnn int mtu = 0; 371171133Sgnn /* 372171133Sgnn * If the packet is routed over IPsec tunnel, tell the 373171133Sgnn * originator the tunnel MTU. 374171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 375171133Sgnn * XXX quickhack!!! 376171133Sgnn */ 377177166Sbz#ifdef IPSEC 378171133Sgnn struct secpolicy *sp = NULL; 379171133Sgnn int ipsecerror; 380171133Sgnn int ipsechdr; 381171133Sgnn struct route *ro; 382171133Sgnn sp = ipsec_getpolicybyaddr(m, 383171133Sgnn IPSEC_DIR_OUTBOUND, 384171133Sgnn IP_FORWARDING, 385171133Sgnn &ipsecerror); 386171133Sgnn if (sp != NULL) { 387171133Sgnn /* count IPsec header size */ 388188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 389171133Sgnn 390171133Sgnn /* 391171133Sgnn * find the correct route for outer IPv4 392171133Sgnn * header, compute tunnel MTU. 393171133Sgnn */ 394171133Sgnn if (sp->req != NULL && 395171133Sgnn sp->req->sav != NULL && 396171133Sgnn sp->req->sav->sah != NULL) { 397214250Sbz ro = &sp->req->sav->sah->route_cache.sa_route; 398171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 399262763Sglebius mtu = ro->ro_rt->rt_mtu ? ro->ro_rt->rt_mtu : 400171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 401171133Sgnn mtu -= ipsechdr; 402171133Sgnn } 403171133Sgnn } 404171133Sgnn KEY_FREESP(&sp); 405177166Sbz } 406171167Sgnn#endif /* IPSEC */ 407177166Sbz /* XXX else case missing. */ 408171133Sgnn return mtu; 409171133Sgnn} 410177166Sbz#endif 411