ip6_ipsec.c revision 238877
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 238877 2012-07-29 00:44:41Z bz $"); 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; 131171133Sgnn int s, error; 132171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 133171133Sgnn s = splnet(); 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 splx(s); 143171133Sgnn /*XXX error stat???*/ 144222845Sbz DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/ 145171133Sgnn return 1; 146171133Sgnn } 147171133Sgnn 148171133Sgnn /* 149171133Sgnn * Check security policy against packet attributes. 150171133Sgnn */ 151171133Sgnn error = ipsec_in_reject(sp, m); 152171133Sgnn KEY_FREESP(&sp); 153171133Sgnn splx(s); 154171133Sgnn if (error) { 155181803Sbz V_ip6stat.ip6s_cantforward++; 156171133Sgnn return 1; 157171133Sgnn } 158171167Sgnn#endif /* IPSEC */ 159171133Sgnn return 0; 160171133Sgnn} 161171133Sgnn 162171133Sgnn/* 163171133Sgnn * Check if protocol type doesn't have a further header and do IPSEC 164171133Sgnn * decryption or reject right now. Protocols with further headers get 165171133Sgnn * their IPSEC treatment within the protocol specific processing. 166222845Sbz * Called from ip6_input(). 167171133Sgnn * 1 = drop packet, 0 = continue processing packet. 168171133Sgnn */ 169171133Sgnnint 170171133Sgnnip6_ipsec_input(struct mbuf *m, int nxt) 171171133Sgnn{ 172171167Sgnn#ifdef IPSEC 173171133Sgnn struct m_tag *mtag; 174171133Sgnn struct tdb_ident *tdbi; 175171133Sgnn struct secpolicy *sp; 176171133Sgnn int s, error; 177171133Sgnn /* 178171133Sgnn * enforce IPsec policy checking if we are seeing last header. 179171133Sgnn * note that we do not visit this with protocols with pcb layer 180171133Sgnn * code - like udp/tcp/raw ip. 181171133Sgnn */ 182171133Sgnn if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 183171133Sgnn ipsec6_in_reject(m, NULL)) { 184171133Sgnn 185171133Sgnn /* 186171133Sgnn * Check if the packet has already had IPsec processing 187171133Sgnn * done. If so, then just pass it along. This tag gets 188171133Sgnn * set during AH, ESP, etc. input handling, before the 189171133Sgnn * packet is returned to the ip input queue for delivery. 190171260Sdelphij */ 191171133Sgnn mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 192171133Sgnn s = splnet(); 193171133Sgnn if (mtag != NULL) { 194171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 195171133Sgnn sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 196171133Sgnn } else { 197171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 198171260Sdelphij IP_FORWARDING, &error); 199171133Sgnn } 200171133Sgnn if (sp != NULL) { 201171133Sgnn /* 202171133Sgnn * Check security policy against packet attributes. 203171133Sgnn */ 204171133Sgnn error = ipsec_in_reject(sp, m); 205171133Sgnn KEY_FREESP(&sp); 206171133Sgnn } else { 207171133Sgnn /* XXX error stat??? */ 208171133Sgnn error = EINVAL; 209222845Sbz DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/ 210171133Sgnn return 1; 211171133Sgnn } 212171133Sgnn splx(s); 213171133Sgnn if (error) 214171133Sgnn return 1; 215171133Sgnn } 216171167Sgnn#endif /* IPSEC */ 217171133Sgnn return 0; 218171133Sgnn} 219171133Sgnn 220171133Sgnn/* 221171133Sgnn * Called from ip6_output(). 222171133Sgnn * 1 = drop packet, 0 = continue processing packet, 223171260Sdelphij * -1 = packet was reinjected and stop processing packet 224171260Sdelphij */ 225171133Sgnn 226171133Sgnnint 227171133Sgnnip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error, 228171260Sdelphij struct ifnet **ifp, struct secpolicy **sp) 229171133Sgnn{ 230171167Sgnn#ifdef IPSEC 231171133Sgnn struct tdb_ident *tdbi; 232171133Sgnn struct m_tag *mtag; 233171237Speter /* XXX int s; */ 234171133Sgnn if (sp == NULL) 235171133Sgnn return 1; 236171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 237171133Sgnn if (mtag != NULL) { 238171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 239171133Sgnn *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 240171133Sgnn if (*sp == NULL) 241171133Sgnn *error = -EINVAL; /* force silent drop */ 242171133Sgnn m_tag_delete(*m, mtag); 243171133Sgnn } else { 244171133Sgnn *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags, 245171133Sgnn error, inp); 246171133Sgnn } 247171133Sgnn 248171133Sgnn /* 249171133Sgnn * There are four return cases: 250171260Sdelphij * sp != NULL apply IPsec policy 251171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 252171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 253171133Sgnn * sp == NULL, error != 0 discard packet, report error 254171133Sgnn */ 255171133Sgnn if (*sp != NULL) { 256171133Sgnn /* Loop detection, check if ipsec processing already done */ 257171133Sgnn KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request")); 258171133Sgnn for (mtag = m_tag_first(*m); mtag != NULL; 259171133Sgnn mtag = m_tag_next(*m, mtag)) { 260171133Sgnn if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 261171133Sgnn continue; 262171133Sgnn if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 263171133Sgnn mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 264171133Sgnn continue; 265171133Sgnn /* 266238877Sbz * Check if policy has no SA associated with it. 267171133Sgnn * This can happen when an SP has yet to acquire 268171133Sgnn * an SA; e.g. on first reference. If it occurs, 269171133Sgnn * then we let ipsec4_process_packet do its thing. 270171133Sgnn */ 271171133Sgnn if ((*sp)->req->sav == NULL) 272171133Sgnn break; 273171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 274171133Sgnn if (tdbi->spi == (*sp)->req->sav->spi && 275171133Sgnn tdbi->proto == (*sp)->req->sav->sah->saidx.proto && 276171133Sgnn bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst, 277171133Sgnn sizeof (union sockaddr_union)) == 0) { 278171133Sgnn /* 279171133Sgnn * No IPsec processing is needed, free 280171133Sgnn * reference to SP. 281171133Sgnn * 282171133Sgnn * NB: null pointer to avoid free at 283171133Sgnn * done: below. 284171133Sgnn */ 285177167Sbz KEY_FREESP(sp), *sp = NULL; 286171237Speter /* XXX splx(s); */ 287171133Sgnn goto done; 288171133Sgnn } 289171133Sgnn } 290171133Sgnn 291171133Sgnn /* 292171133Sgnn * Do delayed checksums now because we send before 293171133Sgnn * this is done in the normal processing path. 294236170Sbz * XXX-BZ CSUM_DELAY_DATA_IPV6? 295171133Sgnn */ 296171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 297221129Sbz ipseclog((LOG_DEBUG, 298221129Sbz "%s: we do not support IPv4 over IPv6", __func__)); 299221129Sbz#ifdef INET 300171133Sgnn in_delayed_cksum(*m); 301221129Sbz#endif 302171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 303171133Sgnn } 304171133Sgnn 305171133Sgnn /* 306171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 307171133Sgnn * when an SA acquire is in progress. Don't propagate 308171133Sgnn * this to user-level; it confuses applications. 309171133Sgnn * 310171133Sgnn * XXX this will go away when the SADB is redone. 311171133Sgnn */ 312171133Sgnn if (*error == ENOENT) 313171133Sgnn *error = 0; 314171133Sgnn goto do_ipsec; 315171133Sgnn } else { /* sp == NULL */ 316171133Sgnn if (*error != 0) { 317171133Sgnn /* 318171133Sgnn * Hack: -EINVAL is used to signal that a packet 319171133Sgnn * should be silently discarded. This is typically 320171133Sgnn * because we asked key management for an SA and 321171133Sgnn * it was delayed (e.g. kicked up to IKE). 322171133Sgnn */ 323171133Sgnn if (*error == -EINVAL) 324171133Sgnn *error = 0; 325171133Sgnn goto bad; 326171133Sgnn } else { 327171133Sgnn /* No IPsec processing for this packet. */ 328171133Sgnn } 329171133Sgnn } 330171133Sgnndone: 331171133Sgnn return 0; 332171133Sgnndo_ipsec: 333171133Sgnn return -1; 334171133Sgnnbad: 335171133Sgnn return 1; 336171167Sgnn#endif /* IPSEC */ 337171133Sgnn return 0; 338171133Sgnn} 339171133Sgnn 340177166Sbz#if 0 341171133Sgnn/* 342171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 343171133Sgnn * Called from ip_forward(). 344171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 345171133Sgnn */ 346171133Sgnnint 347171133Sgnnip6_ipsec_mtu(struct mbuf *m) 348171133Sgnn{ 349171133Sgnn int mtu = 0; 350171133Sgnn /* 351171133Sgnn * If the packet is routed over IPsec tunnel, tell the 352171133Sgnn * originator the tunnel MTU. 353171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 354171133Sgnn * XXX quickhack!!! 355171133Sgnn */ 356177166Sbz#ifdef IPSEC 357171133Sgnn struct secpolicy *sp = NULL; 358171133Sgnn int ipsecerror; 359171133Sgnn int ipsechdr; 360171133Sgnn struct route *ro; 361171133Sgnn sp = ipsec_getpolicybyaddr(m, 362171133Sgnn IPSEC_DIR_OUTBOUND, 363171133Sgnn IP_FORWARDING, 364171133Sgnn &ipsecerror); 365171133Sgnn if (sp != NULL) { 366171133Sgnn /* count IPsec header size */ 367188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 368171133Sgnn 369171133Sgnn /* 370171133Sgnn * find the correct route for outer IPv4 371171133Sgnn * header, compute tunnel MTU. 372171133Sgnn */ 373171133Sgnn if (sp->req != NULL && 374171133Sgnn sp->req->sav != NULL && 375171133Sgnn sp->req->sav->sah != NULL) { 376214250Sbz ro = &sp->req->sav->sah->route_cache.sa_route; 377171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 378171133Sgnn mtu = 379171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu ? 380171133Sgnn ro->ro_rt->rt_rmx.rmx_mtu : 381171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 382171133Sgnn mtu -= ipsechdr; 383171133Sgnn } 384171133Sgnn } 385171133Sgnn KEY_FREESP(&sp); 386177166Sbz } 387171167Sgnn#endif /* IPSEC */ 388177166Sbz /* XXX else case missing. */ 389171133Sgnn return mtu; 390171133Sgnn} 391177166Sbz#endif 392