ip6_ipsec.c revision 262763
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 262763 2014-03-05 01:17:47Z glebius $"); 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, 224171260Sdelphij struct ifnet **ifp, struct secpolicy **sp) 225171133Sgnn{ 226171167Sgnn#ifdef IPSEC 227171133Sgnn struct tdb_ident *tdbi; 228171133Sgnn struct m_tag *mtag; 229171237Speter /* XXX int s; */ 230171133Sgnn if (sp == NULL) 231171133Sgnn return 1; 232171133Sgnn mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 233171133Sgnn if (mtag != NULL) { 234171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 235171133Sgnn *sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 236171133Sgnn if (*sp == NULL) 237171133Sgnn *error = -EINVAL; /* force silent drop */ 238171133Sgnn m_tag_delete(*m, mtag); 239171133Sgnn } else { 240171133Sgnn *sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags, 241171133Sgnn error, inp); 242171133Sgnn } 243171133Sgnn 244171133Sgnn /* 245171133Sgnn * There are four return cases: 246171260Sdelphij * sp != NULL apply IPsec policy 247171133Sgnn * sp == NULL, error == 0 no IPsec handling needed 248171133Sgnn * sp == NULL, error == -EINVAL discard packet w/o error 249171133Sgnn * sp == NULL, error != 0 discard packet, report error 250171133Sgnn */ 251171133Sgnn if (*sp != NULL) { 252171133Sgnn /* Loop detection, check if ipsec processing already done */ 253171133Sgnn KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request")); 254171133Sgnn for (mtag = m_tag_first(*m); mtag != NULL; 255171133Sgnn mtag = m_tag_next(*m, mtag)) { 256171133Sgnn if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 257171133Sgnn continue; 258171133Sgnn if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 259171133Sgnn mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 260171133Sgnn continue; 261171133Sgnn /* 262238877Sbz * Check if policy has no SA associated with it. 263171133Sgnn * This can happen when an SP has yet to acquire 264171133Sgnn * an SA; e.g. on first reference. If it occurs, 265171133Sgnn * then we let ipsec4_process_packet do its thing. 266171133Sgnn */ 267171133Sgnn if ((*sp)->req->sav == NULL) 268171133Sgnn break; 269171133Sgnn tdbi = (struct tdb_ident *)(mtag + 1); 270171133Sgnn if (tdbi->spi == (*sp)->req->sav->spi && 271171133Sgnn tdbi->proto == (*sp)->req->sav->sah->saidx.proto && 272171133Sgnn bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst, 273171133Sgnn sizeof (union sockaddr_union)) == 0) { 274171133Sgnn /* 275171133Sgnn * No IPsec processing is needed, free 276171133Sgnn * reference to SP. 277171133Sgnn * 278171133Sgnn * NB: null pointer to avoid free at 279171133Sgnn * done: below. 280171133Sgnn */ 281177167Sbz KEY_FREESP(sp), *sp = NULL; 282171133Sgnn goto done; 283171133Sgnn } 284171133Sgnn } 285171133Sgnn 286171133Sgnn /* 287171133Sgnn * Do delayed checksums now because we send before 288171133Sgnn * this is done in the normal processing path. 289238935Sbz * For IPv6 we do delayed checksums in ip6_output.c. 290171133Sgnn */ 291238935Sbz#ifdef INET 292171133Sgnn if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 293221129Sbz ipseclog((LOG_DEBUG, 294221129Sbz "%s: we do not support IPv4 over IPv6", __func__)); 295171133Sgnn in_delayed_cksum(*m); 296171133Sgnn (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 297171133Sgnn } 298238935Sbz#endif 299171133Sgnn 300171133Sgnn /* 301171133Sgnn * Preserve KAME behaviour: ENOENT can be returned 302171133Sgnn * when an SA acquire is in progress. Don't propagate 303171133Sgnn * this to user-level; it confuses applications. 304171133Sgnn * 305171133Sgnn * XXX this will go away when the SADB is redone. 306171133Sgnn */ 307171133Sgnn if (*error == ENOENT) 308171133Sgnn *error = 0; 309171133Sgnn goto do_ipsec; 310171133Sgnn } else { /* sp == NULL */ 311171133Sgnn if (*error != 0) { 312171133Sgnn /* 313171133Sgnn * Hack: -EINVAL is used to signal that a packet 314171133Sgnn * should be silently discarded. This is typically 315171133Sgnn * because we asked key management for an SA and 316171133Sgnn * it was delayed (e.g. kicked up to IKE). 317171133Sgnn */ 318171133Sgnn if (*error == -EINVAL) 319171133Sgnn *error = 0; 320171133Sgnn goto bad; 321171133Sgnn } else { 322171133Sgnn /* No IPsec processing for this packet. */ 323171133Sgnn } 324171133Sgnn } 325171133Sgnndone: 326171133Sgnn return 0; 327171133Sgnndo_ipsec: 328171133Sgnn return -1; 329171133Sgnnbad: 330171133Sgnn return 1; 331171167Sgnn#endif /* IPSEC */ 332171133Sgnn return 0; 333171133Sgnn} 334171133Sgnn 335177166Sbz#if 0 336171133Sgnn/* 337171133Sgnn * Compute the MTU for a forwarded packet that gets IPSEC encapsulated. 338171133Sgnn * Called from ip_forward(). 339171133Sgnn * Returns MTU suggestion for ICMP needfrag reply. 340171133Sgnn */ 341171133Sgnnint 342171133Sgnnip6_ipsec_mtu(struct mbuf *m) 343171133Sgnn{ 344171133Sgnn int mtu = 0; 345171133Sgnn /* 346171133Sgnn * If the packet is routed over IPsec tunnel, tell the 347171133Sgnn * originator the tunnel MTU. 348171133Sgnn * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 349171133Sgnn * XXX quickhack!!! 350171133Sgnn */ 351177166Sbz#ifdef IPSEC 352171133Sgnn struct secpolicy *sp = NULL; 353171133Sgnn int ipsecerror; 354171133Sgnn int ipsechdr; 355171133Sgnn struct route *ro; 356171133Sgnn sp = ipsec_getpolicybyaddr(m, 357171133Sgnn IPSEC_DIR_OUTBOUND, 358171133Sgnn IP_FORWARDING, 359171133Sgnn &ipsecerror); 360171133Sgnn if (sp != NULL) { 361171133Sgnn /* count IPsec header size */ 362188306Sbz ipsechdr = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 363171133Sgnn 364171133Sgnn /* 365171133Sgnn * find the correct route for outer IPv4 366171133Sgnn * header, compute tunnel MTU. 367171133Sgnn */ 368171133Sgnn if (sp->req != NULL && 369171133Sgnn sp->req->sav != NULL && 370171133Sgnn sp->req->sav->sah != NULL) { 371214250Sbz ro = &sp->req->sav->sah->route_cache.sa_route; 372171133Sgnn if (ro->ro_rt && ro->ro_rt->rt_ifp) { 373262763Sglebius mtu = ro->ro_rt->rt_mtu ? ro->ro_rt->rt_mtu : 374171133Sgnn ro->ro_rt->rt_ifp->if_mtu; 375171133Sgnn mtu -= ipsechdr; 376171133Sgnn } 377171133Sgnn } 378171133Sgnn KEY_FREESP(&sp); 379177166Sbz } 380171167Sgnn#endif /* IPSEC */ 381177166Sbz /* XXX else case missing. */ 382171133Sgnn return mtu; 383171133Sgnn} 384177166Sbz#endif 385