1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 The FreeBSD Project. 5 * Copyright (c) 2015 Andrey V. Elsukov <ae@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/hhook.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/module.h> 43 #include <machine/bus.h> 44 #include <sys/rman.h> 45 #include <sys/socket.h> 46 #include <sys/sockio.h> 47 #include <sys/sysctl.h> 48 49 #include <net/if.h> 50 #include <net/if_enc.h> 51 #include <net/if_var.h> 52 #include <net/if_clone.h> 53 #include <net/if_types.h> 54 #include <net/pfil.h> 55 #include <net/route.h> 56 #include <net/netisr.h> 57 #include <net/bpf.h> 58 #include <net/vnet.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_systm.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_var.h> 64 #include <netinet/in_var.h> 65 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #include <netinet6/ip6_var.h> 69 #endif 70 71 #include <netipsec/ipsec.h> 72 #include <netipsec/xform.h> 73 74 #define ENCMTU (1024+512) 75 76 /* XXX this define must have the same value as in OpenBSD */ 77 #define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 78 #define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 79 #define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 80 81 struct enchdr { 82 u_int32_t af; 83 u_int32_t spi; 84 u_int32_t flags; 85 }; 86 struct enc_softc { 87 struct ifnet *sc_ifp; 88 }; 89 static VNET_DEFINE(struct enc_softc *, enc_sc); 90 #define V_enc_sc VNET(enc_sc) 91 static VNET_DEFINE(struct if_clone *, enc_cloner); 92 #define V_enc_cloner VNET(enc_cloner) 93 94 static int enc_ioctl(struct ifnet *, u_long, caddr_t); 95 static int enc_output(struct ifnet *, struct mbuf *, 96 const struct sockaddr *, struct route *); 97 static int enc_clone_create(struct if_clone *, int, caddr_t); 98 static void enc_clone_destroy(struct ifnet *); 99 static int enc_add_hhooks(struct enc_softc *); 100 static void enc_remove_hhooks(struct enc_softc *); 101 102 static const char encname[] = "enc"; 103 104 #define IPSEC_ENC_AFTER_PFIL 0x04 105 /* 106 * Before and after are relative to when we are stripping the 107 * outer IP header. 108 * 109 * AFTER_PFIL flag used only for bpf_mask_*. It enables BPF capturing 110 * after PFIL hook execution. It might be useful when PFIL hook does 111 * some changes to the packet, e.g. address translation. If PFIL hook 112 * consumes mbuf, nothing will be captured. 113 */ 114 static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 115 static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 116 static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 117 static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 118 #define V_filter_mask_in VNET(filter_mask_in) 119 #define V_bpf_mask_in VNET(bpf_mask_in) 120 #define V_filter_mask_out VNET(filter_mask_out) 121 #define V_bpf_mask_out VNET(bpf_mask_out) 122 123 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 124 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 125 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 126 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 127 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 128 "IPsec input firewall filter mask"); 129 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 130 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 131 "IPsec input bpf mask"); 132 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 133 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 134 "IPsec output firewall filter mask"); 135 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 136 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 137 "IPsec output bpf mask"); 138 139 static void 140 enc_clone_destroy(struct ifnet *ifp) 141 { 142 struct enc_softc *sc; 143 144 sc = ifp->if_softc; 145 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 146 147 bpfdetach(ifp); 148 if_detach(ifp); 149 if_free(ifp); 150 free(sc, M_DEVBUF); 151 V_enc_sc = NULL; 152 } 153 154 static int 155 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 156 { 157 struct ifnet *ifp; 158 struct enc_softc *sc; 159 160 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 161 M_WAITOK | M_ZERO); 162 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 163 if (ifp == NULL) { 164 free(sc, M_DEVBUF); 165 return (ENOSPC); 166 } 167 if (V_enc_sc != NULL) { 168 if_free(ifp); 169 free(sc, M_DEVBUF); 170 return (EEXIST); 171 } 172 V_enc_sc = sc; 173 if_initname(ifp, encname, unit); 174 ifp->if_mtu = ENCMTU; 175 ifp->if_ioctl = enc_ioctl; 176 ifp->if_output = enc_output; 177 ifp->if_softc = sc; 178 if_attach(ifp); 179 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 180 return (0); 181 } 182 183 static int 184 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 185 struct route *ro) 186 { 187 188 m_freem(m); 189 return (0); 190 } 191 192 static int 193 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 194 { 195 196 if (cmd != SIOCSIFFLAGS) 197 return (EINVAL); 198 if (ifp->if_flags & IFF_UP) 199 ifp->if_drv_flags |= IFF_DRV_RUNNING; 200 else 201 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 202 return (0); 203 } 204 205 static void 206 enc_bpftap(struct ifnet *ifp, struct mbuf *m, const struct secasvar *sav, 207 int32_t hhook_type, uint8_t enc, uint8_t af) 208 { 209 struct enchdr hdr; 210 211 if (hhook_type == HHOOK_TYPE_IPSEC_IN && 212 (enc & V_bpf_mask_in) == 0) 213 return; 214 else if (hhook_type == HHOOK_TYPE_IPSEC_OUT && 215 (enc & V_bpf_mask_out) == 0) 216 return; 217 if (bpf_peers_present(ifp->if_bpf) == 0) 218 return; 219 hdr.af = af; 220 hdr.spi = sav->spi; 221 hdr.flags = 0; 222 if (sav->alg_enc != SADB_EALG_NONE) 223 hdr.flags |= M_CONF; 224 if (sav->alg_auth != SADB_AALG_NONE) 225 hdr.flags |= M_AUTH; 226 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), m); 227 } 228 229 /* 230 * One helper hook function is used by any hook points. 231 * + from hhook_type we can determine the packet direction: 232 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 233 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 234 * + udata contains pointer to enc_softc; 235 * + ctx_data contains pointer to struct ipsec_ctx_data. 236 */ 237 static int 238 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 239 void *hdata, struct osd *hosd) 240 { 241 struct ipsec_ctx_data *ctx; 242 struct enc_softc *sc; 243 struct ifnet *ifp, *rcvif; 244 struct pfil_head *ph; 245 int pdir; 246 247 sc = (struct enc_softc *)udata; 248 ifp = sc->sc_ifp; 249 if ((ifp->if_flags & IFF_UP) == 0) 250 return (0); 251 252 ctx = (struct ipsec_ctx_data *)ctx_data; 253 /* XXX: wrong hook point was used by caller? */ 254 if (ctx->af != hhook_id) 255 return (EPFNOSUPPORT); 256 257 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, ctx->enc, ctx->af); 258 switch (hhook_type) { 259 case HHOOK_TYPE_IPSEC_IN: 260 if (ctx->enc == IPSEC_ENC_BEFORE) { 261 /* Do accounting only once */ 262 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 263 if_inc_counter(ifp, IFCOUNTER_IBYTES, 264 (*ctx->mp)->m_pkthdr.len); 265 } 266 if ((ctx->enc & V_filter_mask_in) == 0) 267 return (0); /* skip pfil processing */ 268 pdir = PFIL_IN; 269 break; 270 case HHOOK_TYPE_IPSEC_OUT: 271 if (ctx->enc == IPSEC_ENC_BEFORE) { 272 /* Do accounting only once */ 273 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 274 if_inc_counter(ifp, IFCOUNTER_OBYTES, 275 (*ctx->mp)->m_pkthdr.len); 276 } 277 if ((ctx->enc & V_filter_mask_out) == 0) 278 return (0); /* skip pfil processing */ 279 pdir = PFIL_OUT; 280 break; 281 default: 282 return (EINVAL); 283 } 284 285 switch (hhook_id) { 286 #ifdef INET 287 case AF_INET: 288 ph = &V_inet_pfil_hook; 289 break; 290 #endif 291 #ifdef INET6 292 case AF_INET6: 293 ph = &V_inet6_pfil_hook; 294 break; 295 #endif 296 default: 297 ph = NULL; 298 } 299 if (ph == NULL || !PFIL_HOOKED(ph)) 300 return (0); 301 /* Make a packet looks like it was received on enc(4) */ 302 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 303 (*ctx->mp)->m_pkthdr.rcvif = ifp; 304 if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, ctx->inp) != 0 || 305 *ctx->mp == NULL) { 306 *ctx->mp = NULL; /* consumed by filter */ 307 return (EACCES); 308 } 309 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 310 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, 311 IPSEC_ENC_AFTER_PFIL, ctx->af); 312 return (0); 313 } 314 315 static int 316 enc_add_hhooks(struct enc_softc *sc) 317 { 318 struct hookinfo hki; 319 int error; 320 321 error = EPFNOSUPPORT; 322 hki.hook_func = enc_hhook; 323 hki.hook_helper = NULL; 324 hki.hook_udata = sc; 325 #ifdef INET 326 hki.hook_id = AF_INET; 327 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 328 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 329 &hki, HHOOK_WAITOK); 330 if (error != 0) 331 return (error); 332 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 333 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 334 &hki, HHOOK_WAITOK); 335 if (error != 0) 336 return (error); 337 #endif 338 #ifdef INET6 339 hki.hook_id = AF_INET6; 340 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 341 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 342 &hki, HHOOK_WAITOK); 343 if (error != 0) 344 return (error); 345 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 346 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 347 &hki, HHOOK_WAITOK); 348 if (error != 0) 349 return (error); 350 #endif 351 return (error); 352 } 353 354 static void 355 enc_remove_hhooks(struct enc_softc *sc) 356 { 357 struct hookinfo hki; 358 359 hki.hook_func = enc_hhook; 360 hki.hook_helper = NULL; 361 hki.hook_udata = sc; 362 #ifdef INET 363 hki.hook_id = AF_INET; 364 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 365 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 366 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 367 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 368 #endif 369 #ifdef INET6 370 hki.hook_id = AF_INET6; 371 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 372 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 373 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 374 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 375 #endif 376 } 377 378 static void 379 vnet_enc_init(const void *unused __unused) 380 { 381 382 V_enc_sc = NULL; 383 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 384 enc_clone_destroy, 1); 385 } 386 VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 387 vnet_enc_init, NULL); 388 389 static void 390 vnet_enc_init_proto(void *unused __unused) 391 { 392 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 393 394 if (enc_add_hhooks(V_enc_sc) != 0) 395 enc_clone_destroy(V_enc_sc->sc_ifp); 396 } 397 VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 398 vnet_enc_init_proto, NULL); 399 400 static void 401 vnet_enc_uninit(const void *unused __unused) 402 { 403 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 404 405 if_clone_detach(V_enc_cloner); 406 } 407 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 408 vnet_enc_uninit, NULL); 409 410 /* 411 * The hhook consumer needs to go before ip[6]_destroy are called on 412 * SI_ORDER_THIRD. 413 */ 414 static void 415 vnet_enc_uninit_hhook(const void *unused __unused) 416 { 417 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 418 419 enc_remove_hhooks(V_enc_sc); 420 } 421 VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 422 vnet_enc_uninit_hhook, NULL); 423 424 static int 425 enc_modevent(module_t mod, int type, void *data) 426 { 427 428 switch (type) { 429 case MOD_LOAD: 430 case MOD_UNLOAD: 431 break; 432 default: 433 return (EOPNOTSUPP); 434 } 435 return (0); 436 } 437 438 static moduledata_t enc_mod = { 439 "if_enc", 440 enc_modevent, 441 0 442 }; 443 444 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 445 MODULE_VERSION(if_enc, 1); 446