1 /*- 2 * Copyright (c) 2006 The FreeBSD Project. 3 * Copyright (c) 2015 Andrey V. Elsukov <ae@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include "opt_inet.h" 32 #include "opt_inet6.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/hhook.h> 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/mbuf.h> 40 #include <sys/module.h> 41 #include <machine/bus.h> 42 #include <sys/rman.h> 43 #include <sys/socket.h> 44 #include <sys/sockio.h> 45 #include <sys/sysctl.h> 46 47 #include <net/if.h> 48 #include <net/if_enc.h> 49 #include <net/if_var.h> 50 #include <net/if_clone.h> 51 #include <net/if_types.h> 52 #include <net/pfil.h> 53 #include <net/route.h> 54 #include <net/netisr.h> 55 #include <net/bpf.h> 56 #include <net/vnet.h> 57 58 #include <netinet/in.h> 59 #include <netinet/in_systm.h> 60 #include <netinet/ip.h> 61 #include <netinet/ip_var.h> 62 #include <netinet/in_var.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #include <netinet6/ip6_var.h> 67 #endif 68 69 #include <netipsec/ipsec.h> 70 #include <netipsec/xform.h> 71 72 #define ENCMTU (1024+512) 73 74 /* XXX this define must have the same value as in OpenBSD */ 75 #define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 76 #define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 77 #define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 78 79 struct enchdr { 80 u_int32_t af; 81 u_int32_t spi; 82 u_int32_t flags; 83 }; 84 struct enc_softc { 85 struct ifnet *sc_ifp; 86 }; 87 static VNET_DEFINE(struct enc_softc *, enc_sc); 88 #define V_enc_sc VNET(enc_sc) 89 static VNET_DEFINE(struct if_clone *, enc_cloner); 90 #define V_enc_cloner VNET(enc_cloner) 91 92 static int enc_ioctl(struct ifnet *, u_long, caddr_t); 93 static int enc_output(struct ifnet *, struct mbuf *, 94 const struct sockaddr *, struct route *); 95 static int enc_clone_create(struct if_clone *, int, caddr_t); 96 static void enc_clone_destroy(struct ifnet *); 97 static int enc_add_hhooks(struct enc_softc *); 98 static void enc_remove_hhooks(struct enc_softc *); 99 100 static const char encname[] = "enc"; 101 102 /* 103 * Before and after are relative to when we are stripping the 104 * outer IP header. 105 */ 106 static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 107 static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 108 static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 109 static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 110 #define V_filter_mask_in VNET(filter_mask_in) 111 #define V_bpf_mask_in VNET(bpf_mask_in) 112 #define V_filter_mask_out VNET(filter_mask_out) 113 #define V_bpf_mask_out VNET(bpf_mask_out) 114 115 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 116 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 117 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 118 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 119 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 120 "IPsec input firewall filter mask"); 121 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 122 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 123 "IPsec input bpf mask"); 124 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 125 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 126 "IPsec output firewall filter mask"); 127 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 128 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 129 "IPsec output bpf mask"); 130 131 static void 132 enc_clone_destroy(struct ifnet *ifp) 133 { 134 struct enc_softc *sc; 135 136 sc = ifp->if_softc; 137 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 138 139 bpfdetach(ifp); 140 if_detach(ifp); 141 if_free(ifp); 142 free(sc, M_DEVBUF); 143 V_enc_sc = NULL; 144 } 145 146 static int 147 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 148 { 149 struct ifnet *ifp; 150 struct enc_softc *sc; 151 152 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 153 M_WAITOK | M_ZERO); 154 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 155 if (ifp == NULL) { 156 free(sc, M_DEVBUF); 157 return (ENOSPC); 158 } 159 if (V_enc_sc != NULL) { 160 if_free(ifp); 161 free(sc, M_DEVBUF); 162 return (EEXIST); 163 } 164 V_enc_sc = sc; 165 if_initname(ifp, encname, unit); 166 ifp->if_mtu = ENCMTU; 167 ifp->if_ioctl = enc_ioctl; 168 ifp->if_output = enc_output; 169 ifp->if_softc = sc; 170 if_attach(ifp); 171 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 172 return (0); 173 } 174 175 static int 176 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 177 struct route *ro) 178 { 179 180 m_freem(m); 181 return (0); 182 } 183 184 static int 185 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 186 { 187 188 if (cmd != SIOCSIFFLAGS) 189 return (EINVAL); 190 if (ifp->if_flags & IFF_UP) 191 ifp->if_drv_flags |= IFF_DRV_RUNNING; 192 else 193 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 194 return (0); 195 } 196 197 /* 198 * One helper hook function is used by any hook points. 199 * + from hhook_type we can determine the packet direction: 200 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 201 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 202 * + udata contains pointer to enc_softc; 203 * + ctx_data contains pointer to struct ipsec_ctx_data. 204 */ 205 static int 206 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 207 void *hdata, struct osd *hosd) 208 { 209 struct enchdr hdr; 210 struct ipsec_ctx_data *ctx; 211 struct enc_softc *sc; 212 struct ifnet *ifp, *rcvif; 213 struct pfil_head *ph; 214 int pdir; 215 216 sc = (struct enc_softc *)udata; 217 ifp = sc->sc_ifp; 218 if ((ifp->if_flags & IFF_UP) == 0) 219 return (0); 220 221 ctx = (struct ipsec_ctx_data *)ctx_data; 222 /* XXX: wrong hook point was used by caller? */ 223 if (ctx->af != hhook_id) 224 return (EPFNOSUPPORT); 225 226 if (((hhook_type == HHOOK_TYPE_IPSEC_IN && 227 (ctx->enc & V_bpf_mask_in) != 0) || 228 (hhook_type == HHOOK_TYPE_IPSEC_OUT && 229 (ctx->enc & V_bpf_mask_out) != 0)) && 230 bpf_peers_present(ifp->if_bpf) != 0) { 231 hdr.af = ctx->af; 232 hdr.spi = ctx->sav->spi; 233 hdr.flags = 0; 234 if (ctx->sav->alg_enc != SADB_EALG_NONE) 235 hdr.flags |= M_CONF; 236 if (ctx->sav->alg_auth != SADB_AALG_NONE) 237 hdr.flags |= M_AUTH; 238 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), *ctx->mp); 239 } 240 241 switch (hhook_type) { 242 case HHOOK_TYPE_IPSEC_IN: 243 if (ctx->enc == IPSEC_ENC_BEFORE) { 244 /* Do accounting only once */ 245 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 246 if_inc_counter(ifp, IFCOUNTER_IBYTES, 247 (*ctx->mp)->m_pkthdr.len); 248 } 249 if ((ctx->enc & V_filter_mask_in) == 0) 250 return (0); /* skip pfil processing */ 251 pdir = PFIL_IN; 252 break; 253 case HHOOK_TYPE_IPSEC_OUT: 254 if (ctx->enc == IPSEC_ENC_BEFORE) { 255 /* Do accounting only once */ 256 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 257 if_inc_counter(ifp, IFCOUNTER_OBYTES, 258 (*ctx->mp)->m_pkthdr.len); 259 } 260 if ((ctx->enc & V_filter_mask_out) == 0) 261 return (0); /* skip pfil processing */ 262 pdir = PFIL_OUT; 263 break; 264 default: 265 return (EINVAL); 266 } 267 268 switch (hhook_id) { 269 #ifdef INET 270 case AF_INET: 271 ph = &V_inet_pfil_hook; 272 break; 273 #endif 274 #ifdef INET6 275 case AF_INET6: 276 ph = &V_inet6_pfil_hook; 277 break; 278 #endif 279 default: 280 ph = NULL; 281 } 282 if (ph == NULL || !PFIL_HOOKED(ph)) 283 return (0); 284 /* Make a packet looks like it was received on enc(4) */ 285 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 286 (*ctx->mp)->m_pkthdr.rcvif = ifp; 287 if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, ctx->inp) != 0 || 288 *ctx->mp == NULL) { 289 *ctx->mp = NULL; /* consumed by filter */ 290 return (EACCES); 291 } 292 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 293 return (0); 294 } 295 296 static int 297 enc_add_hhooks(struct enc_softc *sc) 298 { 299 struct hookinfo hki; 300 int error; 301 302 error = EPFNOSUPPORT; 303 hki.hook_func = enc_hhook; 304 hki.hook_helper = NULL; 305 hki.hook_udata = sc; 306 #ifdef INET 307 hki.hook_id = AF_INET; 308 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 309 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 310 &hki, HHOOK_WAITOK); 311 if (error != 0) 312 return (error); 313 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 314 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 315 &hki, HHOOK_WAITOK); 316 if (error != 0) 317 return (error); 318 #endif 319 #ifdef INET6 320 hki.hook_id = AF_INET6; 321 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 322 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 323 &hki, HHOOK_WAITOK); 324 if (error != 0) 325 return (error); 326 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 327 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 328 &hki, HHOOK_WAITOK); 329 if (error != 0) 330 return (error); 331 #endif 332 return (error); 333 } 334 335 static void 336 enc_remove_hhooks(struct enc_softc *sc) 337 { 338 struct hookinfo hki; 339 340 hki.hook_func = enc_hhook; 341 hki.hook_helper = NULL; 342 hki.hook_udata = sc; 343 #ifdef INET 344 hki.hook_id = AF_INET; 345 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 346 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 347 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 348 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 349 #endif 350 #ifdef INET6 351 hki.hook_id = AF_INET6; 352 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 353 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 354 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 355 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 356 #endif 357 } 358 359 static void 360 vnet_enc_init(const void *unused __unused) 361 { 362 363 V_enc_sc = NULL; 364 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 365 enc_clone_destroy, 1); 366 } 367 VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 368 vnet_enc_init, NULL); 369 370 static void 371 vnet_enc_init_proto(void *unused __unused) 372 { 373 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 374 375 if (enc_add_hhooks(V_enc_sc) != 0) 376 enc_clone_destroy(V_enc_sc->sc_ifp); 377 } 378 VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 379 vnet_enc_init_proto, NULL); 380 381 static void 382 vnet_enc_uninit(const void *unused __unused) 383 { 384 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 385 386 if_clone_detach(V_enc_cloner); 387 } 388 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 389 vnet_enc_uninit, NULL); 390 391 /* 392 * The hhook consumer needs to go before ip[6]_destroy are called on 393 * SI_ORDER_THIRD. 394 */ 395 static void 396 vnet_enc_uninit_hhook(const void *unused __unused) 397 { 398 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 399 400 enc_remove_hhooks(V_enc_sc); 401 } 402 VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 403 vnet_enc_uninit_hhook, NULL); 404 405 static int 406 enc_modevent(module_t mod, int type, void *data) 407 { 408 409 switch (type) { 410 case MOD_LOAD: 411 case MOD_UNLOAD: 412 break; 413 default: 414 return (EOPNOTSUPP); 415 } 416 return (0); 417 } 418 419 static moduledata_t enc_mod = { 420 "if_enc", 421 enc_modevent, 422 0 423 }; 424 425 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 426 MODULE_VERSION(if_enc, 1); 427