1 /*- 2 * Copyright (c) 2006 The FreeBSD Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 #include "opt_enc.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/mbuf.h> 39 #include <sys/module.h> 40 #include <machine/bus.h> 41 #include <sys/rman.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/sysctl.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_clone.h> 49 #include <net/if_types.h> 50 #include <net/pfil.h> 51 #include <net/route.h> 52 #include <net/netisr.h> 53 #include <net/bpf.h> 54 #include <net/vnet.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_var.h> 60 #include <netinet/in_var.h> 61 62 #ifdef INET6 63 #include <netinet/ip6.h> 64 #include <netinet6/ip6_var.h> 65 #endif 66 67 #include <netipsec/ipsec.h> 68 #include <netipsec/xform.h> 69 70 #define ENCMTU (1024+512) 71 72 /* XXX this define must have the same value as in OpenBSD */ 73 #define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 74 #define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 75 #define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 76 77 struct enchdr { 78 u_int32_t af; 79 u_int32_t spi; 80 u_int32_t flags; 81 }; 82 83 struct ifnet *encif; 84 static struct mtx enc_mtx; 85 86 struct enc_softc { 87 struct ifnet *sc_ifp; 88 }; 89 90 static int enc_ioctl(struct ifnet *, u_long, caddr_t); 91 static int enc_output(struct ifnet *ifp, struct mbuf *m, 92 const struct sockaddr *dst, struct route *ro); 93 static int enc_clone_create(struct if_clone *, int, caddr_t); 94 static void enc_clone_destroy(struct ifnet *); 95 static struct if_clone *enc_cloner; 96 static const char encname[] = "enc"; 97 98 /* 99 * Sysctls. 100 */ 101 102 /* 103 * Before and after are relative to when we are stripping the 104 * outer IP header. 105 */ 106 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 107 108 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 109 static int ipsec_filter_mask_in = ENC_BEFORE; 110 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, CTLFLAG_RW, 111 &ipsec_filter_mask_in, 0, "IPsec input firewall filter mask"); 112 static int ipsec_bpf_mask_in = ENC_BEFORE; 113 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, CTLFLAG_RW, 114 &ipsec_bpf_mask_in, 0, "IPsec input bpf mask"); 115 116 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 117 static int ipsec_filter_mask_out = ENC_BEFORE; 118 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, CTLFLAG_RW, 119 &ipsec_filter_mask_out, 0, "IPsec output firewall filter mask"); 120 static int ipsec_bpf_mask_out = ENC_BEFORE|ENC_AFTER; 121 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, CTLFLAG_RW, 122 &ipsec_bpf_mask_out, 0, "IPsec output bpf mask"); 123 124 static void 125 enc_clone_destroy(struct ifnet *ifp) 126 { 127 KASSERT(ifp != encif, ("%s: destroying encif", __func__)); 128 129 bpfdetach(ifp); 130 if_detach(ifp); 131 if_free(ifp); 132 } 133 134 static int 135 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 136 { 137 struct ifnet *ifp; 138 struct enc_softc *sc; 139 140 sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO); 141 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 142 if (ifp == NULL) { 143 free(sc, M_DEVBUF); 144 return (ENOSPC); 145 } 146 147 if_initname(ifp, encname, unit); 148 ifp->if_mtu = ENCMTU; 149 ifp->if_ioctl = enc_ioctl; 150 ifp->if_output = enc_output; 151 ifp->if_snd.ifq_maxlen = ifqmaxlen; 152 ifp->if_softc = sc; 153 if_attach(ifp); 154 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 155 156 mtx_lock(&enc_mtx); 157 /* grab a pointer to enc0, ignore the rest */ 158 if (encif == NULL) 159 encif = ifp; 160 mtx_unlock(&enc_mtx); 161 162 return (0); 163 } 164 165 static int 166 enc_modevent(module_t mod, int type, void *data) 167 { 168 switch (type) { 169 case MOD_LOAD: 170 mtx_init(&enc_mtx, "enc mtx", NULL, MTX_DEF); 171 enc_cloner = if_clone_simple(encname, enc_clone_create, 172 enc_clone_destroy, 1); 173 break; 174 case MOD_UNLOAD: 175 printf("enc module unload - not possible for this module\n"); 176 return (EINVAL); 177 default: 178 return (EOPNOTSUPP); 179 } 180 return (0); 181 } 182 183 static moduledata_t enc_mod = { 184 "if_enc", 185 enc_modevent, 186 0 187 }; 188 189 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 190 191 static int 192 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 193 struct route *ro) 194 { 195 m_freem(m); 196 return (0); 197 } 198 199 /* 200 * Process an ioctl request. 201 */ 202 /* ARGSUSED */ 203 static int 204 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 205 { 206 int error = 0; 207 208 mtx_lock(&enc_mtx); 209 210 switch (cmd) { 211 212 case SIOCSIFFLAGS: 213 if (ifp->if_flags & IFF_UP) 214 ifp->if_drv_flags |= IFF_DRV_RUNNING; 215 else 216 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 217 218 break; 219 220 default: 221 error = EINVAL; 222 } 223 224 mtx_unlock(&enc_mtx); 225 return (error); 226 } 227 228 int 229 ipsec_filter(struct mbuf **mp, int dir, int flags) 230 { 231 int error, i; 232 struct ip *ip; 233 struct ifnet *rcvif; 234 235 KASSERT(encif != NULL, ("%s: encif is null", __func__)); 236 KASSERT(flags & (ENC_IN|ENC_OUT), 237 ("%s: invalid flags: %04x", __func__, flags)); 238 239 if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0) 240 return (0); 241 242 if (flags & ENC_IN) { 243 if ((flags & ipsec_filter_mask_in) == 0) 244 return (0); 245 } else { 246 if ((flags & ipsec_filter_mask_out) == 0) 247 return (0); 248 } 249 250 /* Skip pfil(9) if no filters are loaded */ 251 if (1 252 #ifdef INET 253 && !PFIL_HOOKED(&V_inet_pfil_hook) 254 #endif 255 #ifdef INET6 256 && !PFIL_HOOKED(&V_inet6_pfil_hook) 257 #endif 258 ) { 259 return (0); 260 } 261 262 i = min((*mp)->m_pkthdr.len, max_protohdr); 263 if ((*mp)->m_len < i) { 264 *mp = m_pullup(*mp, i); 265 if (*mp == NULL) { 266 printf("%s: m_pullup failed\n", __func__); 267 return (-1); 268 } 269 } 270 271 error = 0; 272 rcvif = (*mp)->m_pkthdr.rcvif; 273 (*mp)->m_pkthdr.rcvif = encif; 274 ip = mtod(*mp, struct ip *); 275 switch (ip->ip_v) { 276 #ifdef INET 277 case 4: 278 error = pfil_run_hooks(&V_inet_pfil_hook, mp, 279 encif, dir, NULL); 280 break; 281 #endif 282 #ifdef INET6 283 case 6: 284 error = pfil_run_hooks(&V_inet6_pfil_hook, mp, 285 encif, dir, NULL); 286 break; 287 #endif 288 default: 289 printf("%s: unknown IP version\n", __func__); 290 } 291 292 /* 293 * If the mbuf was consumed by the filter for requeueing (dummynet, etc) 294 * then error will be zero but we still want to return an error to our 295 * caller so the null mbuf isn't forwarded further. 296 */ 297 if (*mp == NULL && error == 0) 298 return (-1); /* Consumed by the filter */ 299 if (*mp == NULL) 300 return (error); 301 if (error != 0) 302 goto bad; 303 304 (*mp)->m_pkthdr.rcvif = rcvif; 305 return (error); 306 307 bad: 308 m_freem(*mp); 309 *mp = NULL; 310 return (error); 311 } 312 313 void 314 ipsec_bpf(struct mbuf *m, struct secasvar *sav, int af, int flags) 315 { 316 int mflags; 317 struct enchdr hdr; 318 319 KASSERT(encif != NULL, ("%s: encif is null", __func__)); 320 KASSERT(flags & (ENC_IN|ENC_OUT), 321 ("%s: invalid flags: %04x", __func__, flags)); 322 323 if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0) 324 return; 325 326 if (flags & ENC_IN) { 327 if ((flags & ipsec_bpf_mask_in) == 0) 328 return; 329 } else { 330 if ((flags & ipsec_bpf_mask_out) == 0) 331 return; 332 } 333 334 if (bpf_peers_present(encif->if_bpf)) { 335 mflags = 0; 336 hdr.spi = 0; 337 if (!sav) { 338 struct m_tag *mtag; 339 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 340 if (mtag != NULL) { 341 struct tdb_ident *tdbi; 342 tdbi = (struct tdb_ident *) (mtag + 1); 343 if (tdbi->alg_enc != SADB_EALG_NONE) 344 mflags |= M_CONF; 345 if (tdbi->alg_auth != SADB_AALG_NONE) 346 mflags |= M_AUTH; 347 hdr.spi = tdbi->spi; 348 } 349 } else { 350 if (sav->alg_enc != SADB_EALG_NONE) 351 mflags |= M_CONF; 352 if (sav->alg_auth != SADB_AALG_NONE) 353 mflags |= M_AUTH; 354 hdr.spi = sav->spi; 355 } 356 357 /* 358 * We need to prepend the address family as a four byte 359 * field. Cons up a dummy header to pacify bpf. This 360 * is safe because bpf will only read from the mbuf 361 * (i.e., it won't try to free it or keep a pointer a 362 * to it). 363 */ 364 hdr.af = af; 365 /* hdr.spi already set above */ 366 hdr.flags = mflags; 367 368 bpf_mtap2(encif->if_bpf, &hdr, sizeof(hdr), m); 369 } 370 } 371