ip6_ipsec.c revision 195699
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 195699 2009-07-14 22:48:30Z rwatson $"); 32174510Sobrien 33195699Srwatson#include "opt_inet6.h" 34171133Sgnn#include "opt_ipsec.h" 35171133Sgnn 36171133Sgnn#include <sys/param.h> 37171133Sgnn#include <sys/systm.h> 38171133Sgnn#include <sys/kernel.h> 39171133Sgnn#include <sys/mac.h> 40171133Sgnn#include <sys/malloc.h> 41171133Sgnn#include <sys/mbuf.h> 42171133Sgnn#include <sys/protosw.h> 43171133Sgnn#include <sys/socket.h> 44171133Sgnn#include <sys/socketvar.h> 45171133Sgnn#include <sys/sysctl.h> 46181803Sbz#include <sys/vimage.h> 47171133Sgnn 48171133Sgnn#include <net/if.h> 49171133Sgnn#include <net/route.h> 50195699Srwatson#include <net/vnet.h> 51171133Sgnn 52171133Sgnn#include <netinet/in.h> 53171133Sgnn#include <netinet/in_systm.h> 54171133Sgnn#include <netinet/in_var.h> 55171133Sgnn#include <netinet/ip.h> 56180085Sjulian#include <netinet/ip6.h> 57171133Sgnn#include <netinet/in_pcb.h> 58171133Sgnn#include <netinet/ip_var.h> 59171133Sgnn#include <netinet/ip_options.h> 60171133Sgnn 61171133Sgnn#include <machine/in_cksum.h> 62171133Sgnn 63171167Sgnn#ifdef IPSEC 64171133Sgnn#include <netipsec/ipsec.h> 65171133Sgnn#include <netipsec/ipsec6.h> 66171133Sgnn#include <netipsec/xform.h> 67171133Sgnn#include <netipsec/key.h> 68171133Sgnn#ifdef IPSEC_DEBUG 69171133Sgnn#include <netipsec/key_debug.h> 70171133Sgnn#else 71171133Sgnn#define KEYDEBUG(lev,arg) 72171133Sgnn#endif 73171167Sgnn#endif /*IPSEC*/ 74171133Sgnn 75171133Sgnn#include <netinet6/ip6_ipsec.h> 76180090Sbz#include <netinet6/ip6_var.h> 77171133Sgnn 78171133Sgnnextern struct protosw inet6sw[]; 79171133Sgnn 80195699Srwatson 81195699Srwatson#ifdef INET6 82195699Srwatson#ifdef IPSEC 83195699Srwatson#ifdef IPSEC_FILTERTUNNEL 84195699Srwatsonstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1; 85195699Srwatson#else 86195699Srwatsonstatic VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0; 87192648Sbz#endif 88195699Srwatson#define V_ip6_ipsec6_filtertunnel VNET_GET(ip6_ipsec6_filtertunnel) 89192648Sbz 90195699SrwatsonSYSCTL_DECL(_net_inet6_ipsec6); 91195699SrwatsonSYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO, 92195699Srwatson filtertunnel, CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0, 93195699Srwatson "If set filter packets from an IPsec tunnel."); 94195699Srwatson#endif /* IPSEC */ 95195699Srwatson#endif /* INET6 */ 96195699Srwatson 97171133Sgnn/* 98171133Sgnn * Check if we have to jump over firewall processing for this packet. 99171133Sgnn * Called from ip_input(). 100171133Sgnn * 1 = jump over firewall, 0 = packet goes through firewall. 101171133Sgnn */ 102171133Sgnnint 103171732Sbzip6_ipsec_filtertunnel(struct mbuf *m) 104171133Sgnn{ 105192648Sbz#if defined(IPSEC) 106192648Sbz 107171133Sgnn /* 108171732Sbz * Bypass packet filtering for packets from a tunnel. 109171133Sgnn */ 110192648Sbz if (!V_ip6_ipsec6_filtertunnel && 111192648Sbz m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 112171133Sgnn return 1; 113171133Sgnn#endif 114171133Sgnn return 0; 115171133Sgnn} 116171133Sgnn 117171133Sgnn/* 118171133Sgnn * Check if this packet has an active SA and needs to be dropped instead 119171133Sgnn * of forwarded. 120171133Sgnn * Called from ip_input(). 121171133Sgnn * 1 = drop packet, 0 = forward packet. 122171133Sgnn */ 123171133Sgnnint 124171133Sgnnip6_ipsec_fwd(struct mbuf *m) 125171133Sgnn{ 126171167Sgnn#ifdef IPSEC 127171133Sgnn struct m_tag *mtag; 128171133Sgnn struct tdb_ident *tdbi; 129171133Sgnn struct secpolicy *sp; 130171133Sgnn int s, error; 131171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 132171133Sgnn s = splnet(); 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 splx(s); 142171133Sgnn /*XXX error stat???*/ 143171133Sgnn DPRINTF(("ip_input: no SP for forwarding\n")); /*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 splx(s); 153171133Sgnn if (error) { 154181803Sbz V_ip6stat.ip6s_cantforward++; 155171133Sgnn return 1; 156171133Sgnn } 157171167Sgnn#endif /* IPSEC */ 158171133Sgnn return 0; 159171133Sgnn} 160171133Sgnn 161171133Sgnn/* 162171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 163171133Sgnn * decryption or reject right now. Protocols with further headers get 164171133Sgnn * their IPSEC treatment within the protocol specific processing. 165171133Sgnn * Called from ip_input(). 166171133Sgnn * 1 = drop packet, 0 = continue processing packet. 167171133Sgnn */ 168171133Sgnnint 169171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 170171133Sgnn{ 171171167Sgnn#ifdef IPSEC 172171133Sgnn struct m_tag *mtag; 173171133Sgnn struct tdb_ident *tdbi; 174171133Sgnn struct secpolicy *sp; 175171133Sgnn int s, error; 176171133Sgnn /* 177171133Sgnn * enforce IPsec policy checking if we are seeing last header. 178171133Sgnn * note that we do not visit this with protocols with pcb layer 179171133Sgnn * code - like udp/tcp/raw ip. 180171133Sgnn */ 181171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 182171133Sgnn ipsec6_in_reject(m, NULL)) { 183171133Sgnn 184171133Sgnn /* 185171133Sgnn * Check if the packet has already had IPsec processing 186171133Sgnn * done. If so, then just pass it along. This tag gets 187171133Sgnn * set during AH, ESP, etc. input handling, before the 188171133Sgnn * packet is returned to the ip input queue for delivery. 189171260Sdelphij */ 190171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 191171133Sgnn s = splnet(); 192171133Sgnn if (mtag != NULL) { 193171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 194171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 195171133Sgnn } else { 196171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 197171260Sdelphij IP_FORWARDING, &error); 198171133Sgnn } 199171133Sgnn if (sp != NULL) { 200171133Sgnn /* 201171133Sgnn * Check security policy against packet attributes. 202171133Sgnn */ 203171133Sgnn error = ipsec_in_reject(sp, m); 204171133Sgnn KEY_FREESP(&sp); 205171133Sgnn } else { 206171133Sgnn /* XXX error stat??? */ 207171133Sgnn error = EINVAL; 208171133Sgnn DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/ 209171133Sgnn return 1; 210171133Sgnn } 211171133Sgnn splx(s); 212171133Sgnn if (error) 213171133Sgnn return 1; 214171133Sgnn } 215171167Sgnn#endif /* IPSEC */ 216171133Sgnn return 0; 217171133Sgnn} 218171133Sgnn 219171133Sgnn/* 220171133Sgnn * Called from ip6_output(). 221171133Sgnn * 1 = drop packet, 0 = continue processing packet, 222171260Sdelphij * -1 = packet was reinjected and stop processing packet 223171260Sdelphij */ 224171133Sgnn 225171133Sgnnint 226171133Sgnnip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error, 227171260Sdelphij struct ifnet **ifp, struct secpolicy **sp) 228171133Sgnn{ 229171167Sgnn#ifdef IPSEC 230171133Sgnn struct tdb_ident *tdbi; 231171133Sgnn struct m_tag *mtag; 232171237Speter /* XXX int s; */ 233171133Sgnn if (sp == NULL) 234171133Sgnn return 1; 235171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 236171133Sgnn if (mtag != NULL) { 237171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 238171133Sgnn *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 239171133Sgnn if (*sp == NULL) 240171133Sgnn *error = -EINVAL; /* force silent drop */ 241171133Sgnn m_tag_delete(*m, mtag); 242171133Sgnn } else { 243171133Sgnn *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags, 244171133Sgnn error, inp); 245171133Sgnn } 246171133Sgnn 247171133Sgnn /* 248171133Sgnn * There are four return cases: 249171260Sdelphij * sp != NULL apply IPsec policy 250171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 251171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 252171133Sgnn * sp == NULL, error != 0 discard packet, report error 253171133Sgnn */ 254171133Sgnn if (*sp != NULL) { 255171133Sgnn /* Loop detection, check if ipsec processing already done */ 256171133Sgnn KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request")); 257171133Sgnn for (mtag = m_tag_first(*m); mtag != NULL; 258171133Sgnn mtag = m_tag_next(*m, mtag)) { 259171133Sgnn if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 260171133Sgnn continue; 261171133Sgnn if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 262171133Sgnn mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 263171133Sgnn continue; 264171133Sgnn /* 265171133Sgnn * Check if policy has an SA associated with it. 266171133Sgnn * This can happen when an SP has yet to acquire 267171133Sgnn * an SA; e.g. on first reference. If it occurs, 268171133Sgnn * then we let ipsec4_process_packet do its thing. 269171133Sgnn */ 270171133Sgnn if ((*sp)->req->sav == NULL) 271171133Sgnn break; 272171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 273171133Sgnn if (tdbi->spi == (*sp)->req->sav->spi && 274171133Sgnn tdbi->proto == (*sp)->req->sav->sah->saidx.proto && 275171133Sgnn bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst, 276171133Sgnn sizeof (union sockaddr_union)) == 0) { 277171133Sgnn /* 278171133Sgnn * No IPsec processing is needed, free 279171133Sgnn * reference to SP. 280171133Sgnn * 281171133Sgnn * NB: null pointer to avoid free at 282171133Sgnn * done: below. 283171133Sgnn */ 284177167Sbz KEY_FREESP(sp), *sp = NULL; 285171237Speter /* XXX splx(s); */ 286171133Sgnn goto done; 287171133Sgnn } 288171133Sgnn } 289171133Sgnn 290171133Sgnn /* 291171133Sgnn * Do delayed checksums now because we send before 292171133Sgnn * this is done in the normal processing path. 293171133Sgnn */ 294171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 295171133Sgnn in_delayed_cksum(*m); 296171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 297171133Sgnn } 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) { 370171133Sgnn ro = &sp->req->sav->sah->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