ip6_ipsec.c revision 249294
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 249294 2013-04-09 07:11:22Z 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> 50171133Sgnn#include <net/route.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); 92195699SrwatsonSYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO, 93195699Srwatson filtertunnel, 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 m_tag *mtag; 129171133Sgnn struct tdb_ident *tdbi; 130171133Sgnn struct secpolicy *sp; 131241686Sandre int error; 132171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 133171133Sgnn if (mtag != NULL) { 134171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 135171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 136171133Sgnn } else { 137171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 138171260Sdelphij IP_FORWARDING, &error); 139171133Sgnn } 140171133Sgnn if (sp == NULL) { /* NB: can happen if error */ 141171133Sgnn /*XXX error stat???*/ 142222845Sbz DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/ 143171133Sgnn return 1; 144171133Sgnn } 145171133Sgnn 146171133Sgnn /* 147171133Sgnn * Check security policy against packet attributes. 148171133Sgnn */ 149171133Sgnn error = ipsec_in_reject(sp, m); 150171133Sgnn KEY_FREESP(&sp); 151171133Sgnn if (error) { 152249294Sae IP6STAT_INC(ip6s_cantforward); 153171133Sgnn return 1; 154171133Sgnn } 155171167Sgnn#endif /* IPSEC */ 156171133Sgnn return 0; 157171133Sgnn} 158171133Sgnn 159171133Sgnn/* 160171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 161171133Sgnn * decryption or reject right now. Protocols with further headers get 162171133Sgnn * their IPSEC treatment within the protocol specific processing. 163222845Sbz * Called from ip6_input(). 164171133Sgnn * 1 = drop packet, 0 = continue processing packet. 165171133Sgnn */ 166171133Sgnnint 167171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 168171133Sgnn{ 169171167Sgnn#ifdef IPSEC 170171133Sgnn struct m_tag *mtag; 171171133Sgnn struct tdb_ident *tdbi; 172171133Sgnn struct secpolicy *sp; 173241686Sandre int error; 174171133Sgnn /* 175171133Sgnn * enforce IPsec policy checking if we are seeing last header. 176171133Sgnn * note that we do not visit this with protocols with pcb layer 177171133Sgnn * code - like udp/tcp/raw ip. 178171133Sgnn */ 179171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 180171133Sgnn ipsec6_in_reject(m, NULL)) { 181171133Sgnn 182171133Sgnn /* 183171133Sgnn * Check if the packet has already had IPsec processing 184171133Sgnn * done. If so, then just pass it along. This tag gets 185171133Sgnn * set during AH, ESP, etc. input handling, before the 186171133Sgnn * packet is returned to the ip input queue for delivery. 187171260Sdelphij */ 188171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 189171133Sgnn if (mtag != NULL) { 190171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 191171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 192171133Sgnn } else { 193171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 194171260Sdelphij IP_FORWARDING, &error); 195171133Sgnn } 196171133Sgnn if (sp != NULL) { 197171133Sgnn /* 198171133Sgnn * Check security policy against packet attributes. 199171133Sgnn */ 200171133Sgnn error = ipsec_in_reject(sp, m); 201171133Sgnn KEY_FREESP(&sp); 202171133Sgnn } else { 203171133Sgnn /* XXX error stat??? */ 204171133Sgnn error = EINVAL; 205222845Sbz DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/ 206171133Sgnn return 1; 207171133Sgnn } 208171133Sgnn if (error) 209171133Sgnn return 1; 210171133Sgnn } 211171167Sgnn#endif /* IPSEC */ 212171133Sgnn return 0; 213171133Sgnn} 214171133Sgnn 215171133Sgnn/* 216171133Sgnn * Called from ip6_output(). 217171133Sgnn * 1 = drop packet, 0 = continue processing packet, 218171260Sdelphij * -1 = packet was reinjected and stop processing packet 219171260Sdelphij */ 220171133Sgnn 221171133Sgnnint 222171133Sgnnip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error, 223171260Sdelphij struct ifnet **ifp, struct secpolicy **sp) 224171133Sgnn{ 225171167Sgnn#ifdef IPSEC 226171133Sgnn struct tdb_ident *tdbi; 227171133Sgnn struct m_tag *mtag; 228171237Speter /* XXX int s; */ 229171133Sgnn if (sp == NULL) 230171133Sgnn return 1; 231171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 232171133Sgnn if (mtag != NULL) { 233171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 234171133Sgnn *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 235171133Sgnn if (*sp == NULL) 236171133Sgnn *error = -EINVAL; /* force silent drop */ 237171133Sgnn m_tag_delete(*m, mtag); 238171133Sgnn } else { 239171133Sgnn *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 */ 250171133Sgnn if (*sp != NULL) { 251171133Sgnn /* Loop detection, check if ipsec processing already done */ 252171133Sgnn 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 */ 266171133Sgnn if ((*sp)->req->sav == NULL) 267171133Sgnn break; 268171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 269171133Sgnn if (tdbi->spi == (*sp)->req->sav->spi && 270171133Sgnn tdbi->proto == (*sp)->req->sav->sah->saidx.proto && 271171133Sgnn 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 */ 280177167Sbz 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. 288238935Sbz * For IPv6 we do delayed checksums in ip6_output.c. 289171133Sgnn */ 290238935Sbz#ifdef INET 291171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 292221129Sbz ipseclog((LOG_DEBUG, 293221129Sbz "%s: we do not support IPv4 over IPv6", __func__)); 294171133Sgnn in_delayed_cksum(*m); 295171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 296171133Sgnn } 297238935Sbz#endif 298171133Sgnn 299171133Sgnn /* 300171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 301171133Sgnn * when an SA acquire is in progress. Don't propagate 302171133Sgnn * this to user-level; it confuses applications. 303171133Sgnn * 304171133Sgnn * XXX this will go away when the SADB is redone. 305171133Sgnn */ 306171133Sgnn if (*error == ENOENT) 307171133Sgnn *error = 0; 308171133Sgnn goto do_ipsec; 309171133Sgnn } else { /* sp == NULL */ 310171133Sgnn if (*error != 0) { 311171133Sgnn /* 312171133Sgnn * Hack: -EINVAL is used to signal that a packet 313171133Sgnn * should be silently discarded. This is typically 314171133Sgnn * because we asked key management for an SA and 315171133Sgnn * it was delayed (e.g. kicked up to IKE). 316171133Sgnn */ 317171133Sgnn if (*error == -EINVAL) 318171133Sgnn *error = 0; 319171133Sgnn goto bad; 320171133Sgnn } else { 321171133Sgnn /* No IPsec processing for this packet. */ 322171133Sgnn } 323171133Sgnn } 324171133Sgnndone: 325171133Sgnn return 0; 326171133Sgnndo_ipsec: 327171133Sgnn return -1; 328171133Sgnnbad: 329171133Sgnn return 1; 330171167Sgnn#endif /* IPSEC */ 331171133Sgnn return 0; 332171133Sgnn} 333171133Sgnn 334177166Sbz#if 0 335171133Sgnn/* 336171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 337171133Sgnn * Called from ip_forward(). 338171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 339171133Sgnn */ 340171133Sgnnint 341171133Sgnnip6_ipsec_mtu(struct mbuf *m) 342171133Sgnn{ 343171133Sgnn int mtu = 0; 344171133Sgnn /* 345171133Sgnn * If the packet is routed over IPsec tunnel, tell the 346171133Sgnn * originator the tunnel MTU. 347171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 348171133Sgnn * XXX quickhack!!! 349171133Sgnn */ 350177166Sbz#ifdef IPSEC 351171133Sgnn struct secpolicy *sp = NULL; 352171133Sgnn int ipsecerror; 353171133Sgnn int ipsechdr; 354171133Sgnn struct route *ro; 355171133Sgnn sp = ipsec_getpolicybyaddr(m, 356171133Sgnn IPSEC_DIR_OUTBOUND, 357171133Sgnn IP_FORWARDING, 358171133Sgnn &ipsecerror); 359171133Sgnn if (sp != NULL) { 360171133Sgnn /* count IPsec header size */ 361188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 362171133Sgnn 363171133Sgnn /* 364171133Sgnn * find the correct route for outer IPv4 365171133Sgnn * header, compute tunnel MTU. 366171133Sgnn */ 367171133Sgnn if (sp->req != NULL && 368171133Sgnn sp->req->sav != NULL && 369171133Sgnn sp->req->sav->sah != NULL) { 370214250Sbz ro = &sp->req->sav->sah->route_cache.sa_route; 371171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 372171133Sgnn mtu = 373171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu ? 374171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu : 375171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 376171133Sgnn mtu -= ipsechdr; 377171133Sgnn } 378171133Sgnn } 379171133Sgnn KEY_FREESP(&sp); 380177166Sbz } 381171167Sgnn#endif /* IPSEC */ 382177166Sbz /* XXX else case missing. */ 383171133Sgnn return mtu; 384171133Sgnn} 385177166Sbz#endif 386