ip6_ipsec.c revision 192648
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 192648 2009-05-23 16:42:38Z bz $"); 32174510Sobrien 33171133Sgnn#include "opt_ipsec.h" 34171133Sgnn 35171133Sgnn#include <sys/param.h> 36171133Sgnn#include <sys/systm.h> 37171133Sgnn#include <sys/kernel.h> 38171133Sgnn#include <sys/mac.h> 39171133Sgnn#include <sys/malloc.h> 40171133Sgnn#include <sys/mbuf.h> 41171133Sgnn#include <sys/protosw.h> 42171133Sgnn#include <sys/socket.h> 43171133Sgnn#include <sys/socketvar.h> 44171133Sgnn#include <sys/sysctl.h> 45181803Sbz#include <sys/vimage.h> 46171133Sgnn 47171133Sgnn#include <net/if.h> 48171133Sgnn#include <net/route.h> 49171133Sgnn 50171133Sgnn#include <netinet/in.h> 51171133Sgnn#include <netinet/in_systm.h> 52171133Sgnn#include <netinet/in_var.h> 53171133Sgnn#include <netinet/ip.h> 54180085Sjulian#include <netinet/ip6.h> 55171133Sgnn#include <netinet/in_pcb.h> 56171133Sgnn#include <netinet/ip_var.h> 57171133Sgnn#include <netinet/ip_options.h> 58171133Sgnn 59171133Sgnn#include <machine/in_cksum.h> 60171133Sgnn 61171167Sgnn#ifdef IPSEC 62171133Sgnn#include <netipsec/ipsec.h> 63171133Sgnn#include <netipsec/ipsec6.h> 64171133Sgnn#include <netipsec/xform.h> 65171133Sgnn#include <netipsec/key.h> 66171133Sgnn#ifdef IPSEC_DEBUG 67171133Sgnn#include <netipsec/key_debug.h> 68171133Sgnn#else 69171133Sgnn#define KEYDEBUG(lev,arg) 70171133Sgnn#endif 71171167Sgnn#endif /*IPSEC*/ 72171133Sgnn 73171133Sgnn#include <netinet6/ip6_ipsec.h> 74180090Sbz#include <netinet6/ip6_var.h> 75185571Sbz#include <netinet6/vinet6.h> 76171133Sgnn 77171133Sgnnextern struct protosw inet6sw[]; 78171133Sgnn 79192648Sbz#ifdef VIMAGE_GLOBALS 80192648Sbzint ip6_ipsec6_filtertunnel; 81192648Sbz#endif 82192648Sbz 83171133Sgnn/* 84171133Sgnn * Check if we have to jump over firewall processing for this packet. 85171133Sgnn * Called from ip_input(). 86171133Sgnn * 1 = jump over firewall, 0 = packet goes through firewall. 87171133Sgnn */ 88171133Sgnnint 89171732Sbzip6_ipsec_filtertunnel(struct mbuf *m) 90171133Sgnn{ 91192648Sbz#if defined(IPSEC) 92192648Sbz INIT_VNET_IPSEC(curvnet); 93192648Sbz 94171133Sgnn /* 95171732Sbz * Bypass packet filtering for packets from a tunnel. 96171133Sgnn */ 97192648Sbz if (!V_ip6_ipsec6_filtertunnel && 98192648Sbz m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 99171133Sgnn return 1; 100171133Sgnn#endif 101171133Sgnn return 0; 102171133Sgnn} 103171133Sgnn 104171133Sgnn/* 105171133Sgnn * Check if this packet has an active SA and needs to be dropped instead 106171133Sgnn * of forwarded. 107171133Sgnn * Called from ip_input(). 108171133Sgnn * 1 = drop packet, 0 = forward packet. 109171133Sgnn */ 110171133Sgnnint 111171133Sgnnip6_ipsec_fwd(struct mbuf *m) 112171133Sgnn{ 113171167Sgnn#ifdef IPSEC 114183550Szec INIT_VNET_INET6(curvnet); 115183550Szec INIT_VNET_IPSEC(curvnet); 116171133Sgnn struct m_tag *mtag; 117171133Sgnn struct tdb_ident *tdbi; 118171133Sgnn struct secpolicy *sp; 119171133Sgnn int s, error; 120171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 121171133Sgnn s = splnet(); 122171133Sgnn if (mtag != NULL) { 123171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 124171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 125171133Sgnn } else { 126171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 127171260Sdelphij IP_FORWARDING, &error); 128171133Sgnn } 129171133Sgnn if (sp == NULL) { /* NB: can happen if error */ 130171133Sgnn splx(s); 131171133Sgnn /*XXX error stat???*/ 132171133Sgnn DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/ 133171133Sgnn return 1; 134171133Sgnn } 135171133Sgnn 136171133Sgnn /* 137171133Sgnn * Check security policy against packet attributes. 138171133Sgnn */ 139171133Sgnn error = ipsec_in_reject(sp, m); 140171133Sgnn KEY_FREESP(&sp); 141171133Sgnn splx(s); 142171133Sgnn if (error) { 143181803Sbz V_ip6stat.ip6s_cantforward++; 144171133Sgnn return 1; 145171133Sgnn } 146171167Sgnn#endif /* IPSEC */ 147171133Sgnn return 0; 148171133Sgnn} 149171133Sgnn 150171133Sgnn/* 151171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 152171133Sgnn * decryption or reject right now. Protocols with further headers get 153171133Sgnn * their IPSEC treatment within the protocol specific processing. 154171133Sgnn * Called from ip_input(). 155171133Sgnn * 1 = drop packet, 0 = continue processing packet. 156171133Sgnn */ 157171133Sgnnint 158171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 159171133Sgnn{ 160171167Sgnn#ifdef IPSEC 161183550Szec INIT_VNET_IPSEC(curvnet); 162171133Sgnn struct m_tag *mtag; 163171133Sgnn struct tdb_ident *tdbi; 164171133Sgnn struct secpolicy *sp; 165171133Sgnn int s, error; 166171133Sgnn /* 167171133Sgnn * enforce IPsec policy checking if we are seeing last header. 168171133Sgnn * note that we do not visit this with protocols with pcb layer 169171133Sgnn * code - like udp/tcp/raw ip. 170171133Sgnn */ 171171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 172171133Sgnn ipsec6_in_reject(m, NULL)) { 173171133Sgnn 174171133Sgnn /* 175171133Sgnn * Check if the packet has already had IPsec processing 176171133Sgnn * done. If so, then just pass it along. This tag gets 177171133Sgnn * set during AH, ESP, etc. input handling, before the 178171133Sgnn * packet is returned to the ip input queue for delivery. 179171260Sdelphij */ 180171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 181171133Sgnn s = splnet(); 182171133Sgnn if (mtag != NULL) { 183171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 184171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 185171133Sgnn } else { 186171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 187171260Sdelphij IP_FORWARDING, &error); 188171133Sgnn } 189171133Sgnn if (sp != NULL) { 190171133Sgnn /* 191171133Sgnn * Check security policy against packet attributes. 192171133Sgnn */ 193171133Sgnn error = ipsec_in_reject(sp, m); 194171133Sgnn KEY_FREESP(&sp); 195171133Sgnn } else { 196171133Sgnn /* XXX error stat??? */ 197171133Sgnn error = EINVAL; 198171133Sgnn DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/ 199171133Sgnn return 1; 200171133Sgnn } 201171133Sgnn splx(s); 202171133Sgnn if (error) 203171133Sgnn return 1; 204171133Sgnn } 205171167Sgnn#endif /* IPSEC */ 206171133Sgnn return 0; 207171133Sgnn} 208171133Sgnn 209171133Sgnn/* 210171133Sgnn * Called from ip6_output(). 211171133Sgnn * 1 = drop packet, 0 = continue processing packet, 212171260Sdelphij * -1 = packet was reinjected and stop processing packet 213171260Sdelphij */ 214171133Sgnn 215171133Sgnnint 216171133Sgnnip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error, 217171260Sdelphij struct ifnet **ifp, struct secpolicy **sp) 218171133Sgnn{ 219171167Sgnn#ifdef IPSEC 220171133Sgnn struct tdb_ident *tdbi; 221171133Sgnn struct m_tag *mtag; 222171237Speter /* XXX int s; */ 223171133Sgnn if (sp == NULL) 224171133Sgnn return 1; 225171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 226171133Sgnn if (mtag != NULL) { 227171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 228171133Sgnn *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 229171133Sgnn if (*sp == NULL) 230171133Sgnn *error = -EINVAL; /* force silent drop */ 231171133Sgnn m_tag_delete(*m, mtag); 232171133Sgnn } else { 233171133Sgnn *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags, 234171133Sgnn error, inp); 235171133Sgnn } 236171133Sgnn 237171133Sgnn /* 238171133Sgnn * There are four return cases: 239171260Sdelphij * sp != NULL apply IPsec policy 240171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 241171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 242171133Sgnn * sp == NULL, error != 0 discard packet, report error 243171133Sgnn */ 244171133Sgnn if (*sp != NULL) { 245171133Sgnn /* Loop detection, check if ipsec processing already done */ 246171133Sgnn KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request")); 247171133Sgnn for (mtag = m_tag_first(*m); mtag != NULL; 248171133Sgnn mtag = m_tag_next(*m, mtag)) { 249171133Sgnn if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 250171133Sgnn continue; 251171133Sgnn if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 252171133Sgnn mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 253171133Sgnn continue; 254171133Sgnn /* 255171133Sgnn * Check if policy has an SA associated with it. 256171133Sgnn * This can happen when an SP has yet to acquire 257171133Sgnn * an SA; e.g. on first reference. If it occurs, 258171133Sgnn * then we let ipsec4_process_packet do its thing. 259171133Sgnn */ 260171133Sgnn if ((*sp)->req->sav == NULL) 261171133Sgnn break; 262171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 263171133Sgnn if (tdbi->spi == (*sp)->req->sav->spi && 264171133Sgnn tdbi->proto == (*sp)->req->sav->sah->saidx.proto && 265171133Sgnn bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst, 266171133Sgnn sizeof (union sockaddr_union)) == 0) { 267171133Sgnn /* 268171133Sgnn * No IPsec processing is needed, free 269171133Sgnn * reference to SP. 270171133Sgnn * 271171133Sgnn * NB: null pointer to avoid free at 272171133Sgnn * done: below. 273171133Sgnn */ 274177167Sbz KEY_FREESP(sp), *sp = NULL; 275171237Speter /* XXX splx(s); */ 276171133Sgnn goto done; 277171133Sgnn } 278171133Sgnn } 279171133Sgnn 280171133Sgnn /* 281171133Sgnn * Do delayed checksums now because we send before 282171133Sgnn * this is done in the normal processing path. 283171133Sgnn */ 284171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 285171133Sgnn in_delayed_cksum(*m); 286171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 287171133Sgnn } 288171133Sgnn 289171133Sgnn /* 290171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 291171133Sgnn * when an SA acquire is in progress. Don't propagate 292171133Sgnn * this to user-level; it confuses applications. 293171133Sgnn * 294171133Sgnn * XXX this will go away when the SADB is redone. 295171133Sgnn */ 296171133Sgnn if (*error == ENOENT) 297171133Sgnn *error = 0; 298171133Sgnn goto do_ipsec; 299171133Sgnn } else { /* sp == NULL */ 300171133Sgnn if (*error != 0) { 301171133Sgnn /* 302171133Sgnn * Hack: -EINVAL is used to signal that a packet 303171133Sgnn * should be silently discarded. This is typically 304171133Sgnn * because we asked key management for an SA and 305171133Sgnn * it was delayed (e.g. kicked up to IKE). 306171133Sgnn */ 307171133Sgnn if (*error == -EINVAL) 308171133Sgnn *error = 0; 309171133Sgnn goto bad; 310171133Sgnn } else { 311171133Sgnn /* No IPsec processing for this packet. */ 312171133Sgnn } 313171133Sgnn } 314171133Sgnndone: 315171133Sgnn return 0; 316171133Sgnndo_ipsec: 317171133Sgnn return -1; 318171133Sgnnbad: 319171133Sgnn return 1; 320171167Sgnn#endif /* IPSEC */ 321171133Sgnn return 0; 322171133Sgnn} 323171133Sgnn 324177166Sbz#if 0 325171133Sgnn/* 326171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 327171133Sgnn * Called from ip_forward(). 328171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 329171133Sgnn */ 330171133Sgnnint 331171133Sgnnip6_ipsec_mtu(struct mbuf *m) 332171133Sgnn{ 333171133Sgnn int mtu = 0; 334171133Sgnn /* 335171133Sgnn * If the packet is routed over IPsec tunnel, tell the 336171133Sgnn * originator the tunnel MTU. 337171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 338171133Sgnn * XXX quickhack!!! 339171133Sgnn */ 340177166Sbz#ifdef IPSEC 341171133Sgnn struct secpolicy *sp = NULL; 342171133Sgnn int ipsecerror; 343171133Sgnn int ipsechdr; 344171133Sgnn struct route *ro; 345171133Sgnn sp = ipsec_getpolicybyaddr(m, 346171133Sgnn IPSEC_DIR_OUTBOUND, 347171133Sgnn IP_FORWARDING, 348171133Sgnn &ipsecerror); 349171133Sgnn if (sp != NULL) { 350171133Sgnn /* count IPsec header size */ 351188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 352171133Sgnn 353171133Sgnn /* 354171133Sgnn * find the correct route for outer IPv4 355171133Sgnn * header, compute tunnel MTU. 356171133Sgnn */ 357171133Sgnn if (sp->req != NULL && 358171133Sgnn sp->req->sav != NULL && 359171133Sgnn sp->req->sav->sah != NULL) { 360171133Sgnn ro = &sp->req->sav->sah->sa_route; 361171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 362171133Sgnn mtu = 363171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu ? 364171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu : 365171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 366171133Sgnn mtu -= ipsechdr; 367171133Sgnn } 368171133Sgnn } 369171133Sgnn KEY_FREESP(&sp); 370177166Sbz } 371171167Sgnn#endif /* IPSEC */ 372177166Sbz /* XXX else case missing. */ 373171133Sgnn return mtu; 374171133Sgnn} 375177166Sbz#endif 376