1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 31 #include "opt_inet.h" 32 #include "opt_inet6.h" 33 #include "opt_ipsec.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/hhook.h> 38 #include <sys/kernel.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/module.h> 42 #include <machine/bus.h> 43 #include <sys/rman.h> 44 #include <sys/socket.h> 45 #include <sys/sockio.h> 46 #include <sys/sysctl.h> 47 48 #include <net/if.h> 49 #include <net/if_enc.h> 50 #include <net/if_var.h> 51 #include <net/if_private.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 VNET_DEFINE_STATIC(struct enc_softc *, enc_sc); 90 #define V_enc_sc VNET(enc_sc) 91 VNET_DEFINE_STATIC(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 VNET_DEFINE_STATIC(int, filter_mask_in) = IPSEC_ENC_BEFORE; 115 VNET_DEFINE_STATIC(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 116 VNET_DEFINE_STATIC(int, filter_mask_out) = IPSEC_ENC_BEFORE; 117 VNET_DEFINE_STATIC(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 | CTLFLAG_MPSAFE, 0, 124 "enc sysctl"); 125 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 126 "enc input sysctl"); 127 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 128 "enc output sysctl"); 129 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 130 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 131 "IPsec input firewall filter mask"); 132 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 133 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 134 "IPsec input bpf mask"); 135 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 136 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 137 "IPsec output firewall filter mask"); 138 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 139 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 140 "IPsec output bpf mask"); 141 142 static void 143 enc_clone_destroy(struct ifnet *ifp) 144 { 145 struct enc_softc *sc; 146 147 sc = ifp->if_softc; 148 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 149 150 bpfdetach(ifp); 151 if_detach(ifp); 152 if_free(ifp); 153 free(sc, M_DEVBUF); 154 V_enc_sc = NULL; 155 } 156 157 static int 158 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 159 { 160 struct ifnet *ifp; 161 struct enc_softc *sc; 162 163 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 164 M_WAITOK | M_ZERO); 165 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 166 if (ifp == NULL) { 167 free(sc, M_DEVBUF); 168 return (ENOSPC); 169 } 170 if (V_enc_sc != NULL) { 171 if_free(ifp); 172 free(sc, M_DEVBUF); 173 return (EEXIST); 174 } 175 V_enc_sc = sc; 176 if_initname(ifp, encname, unit); 177 ifp->if_mtu = ENCMTU; 178 ifp->if_ioctl = enc_ioctl; 179 ifp->if_output = enc_output; 180 ifp->if_softc = sc; 181 if_attach(ifp); 182 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 183 return (0); 184 } 185 186 static int 187 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 188 struct route *ro) 189 { 190 191 m_freem(m); 192 return (0); 193 } 194 195 static int 196 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 197 { 198 199 if (cmd != SIOCSIFFLAGS) 200 return (EINVAL); 201 if (ifp->if_flags & IFF_UP) 202 ifp->if_drv_flags |= IFF_DRV_RUNNING; 203 else 204 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 205 return (0); 206 } 207 208 static void 209 enc_bpftap(struct ifnet *ifp, struct mbuf *m, const struct secasvar *sav, 210 int32_t hhook_type, uint8_t enc, uint8_t af) 211 { 212 struct enchdr hdr; 213 214 if (hhook_type == HHOOK_TYPE_IPSEC_IN && 215 (enc & V_bpf_mask_in) == 0) 216 return; 217 else if (hhook_type == HHOOK_TYPE_IPSEC_OUT && 218 (enc & V_bpf_mask_out) == 0) 219 return; 220 if (bpf_peers_present(ifp->if_bpf) == 0) 221 return; 222 hdr.af = af; 223 hdr.spi = sav->spi; 224 hdr.flags = 0; 225 if (sav->alg_enc != SADB_EALG_NONE) 226 hdr.flags |= M_CONF; 227 if (sav->alg_auth != SADB_AALG_NONE) 228 hdr.flags |= M_AUTH; 229 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), m); 230 } 231 232 /* 233 * One helper hook function is used by any hook points. 234 * + from hhook_type we can determine the packet direction: 235 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 236 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 237 * + udata contains pointer to enc_softc; 238 * + ctx_data contains pointer to struct ipsec_ctx_data. 239 */ 240 static int 241 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 242 void *hdata, struct osd *hosd) 243 { 244 struct ipsec_ctx_data *ctx; 245 struct enc_softc *sc; 246 struct ifnet *ifp, *rcvif; 247 struct pfil_head *ph; 248 int pdir, ret; 249 250 sc = (struct enc_softc *)udata; 251 ifp = sc->sc_ifp; 252 if ((ifp->if_flags & IFF_UP) == 0) 253 return (0); 254 255 ctx = (struct ipsec_ctx_data *)ctx_data; 256 /* XXX: wrong hook point was used by caller? */ 257 if (ctx->af != hhook_id) 258 return (EPFNOSUPPORT); 259 260 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, ctx->enc, ctx->af); 261 switch (hhook_type) { 262 case HHOOK_TYPE_IPSEC_IN: 263 if (ctx->enc == IPSEC_ENC_BEFORE) { 264 /* Do accounting only once */ 265 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 266 if_inc_counter(ifp, IFCOUNTER_IBYTES, 267 (*ctx->mp)->m_pkthdr.len); 268 } 269 if ((ctx->enc & V_filter_mask_in) == 0) 270 return (0); /* skip pfil processing */ 271 pdir = PFIL_IN; 272 break; 273 case HHOOK_TYPE_IPSEC_OUT: 274 if (ctx->enc == IPSEC_ENC_BEFORE) { 275 /* Do accounting only once */ 276 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 277 if_inc_counter(ifp, IFCOUNTER_OBYTES, 278 (*ctx->mp)->m_pkthdr.len); 279 } 280 if ((ctx->enc & V_filter_mask_out) == 0) 281 return (0); /* skip pfil processing */ 282 pdir = PFIL_OUT; 283 break; 284 default: 285 return (EINVAL); 286 } 287 288 switch (hhook_id) { 289 #ifdef INET 290 case AF_INET: 291 ph = V_inet_pfil_head; 292 break; 293 #endif 294 #ifdef INET6 295 case AF_INET6: 296 ph = V_inet6_pfil_head; 297 break; 298 #endif 299 default: 300 ph = NULL; 301 } 302 if (ph == NULL || (pdir == PFIL_OUT && !PFIL_HOOKED_OUT(ph)) || 303 (pdir == PFIL_IN && !PFIL_HOOKED_IN(ph))) 304 return (0); 305 /* Make a packet looks like it was received on enc(4) */ 306 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 307 (*ctx->mp)->m_pkthdr.rcvif = ifp; 308 if (pdir == PFIL_IN) 309 ret = pfil_mbuf_in(ph, ctx->mp, ifp, ctx->inp); 310 else 311 ret = pfil_mbuf_out(ph, ctx->mp, ifp, ctx->inp); 312 if (ret != PFIL_PASS) { 313 *ctx->mp = NULL; /* consumed by filter */ 314 return (EACCES); 315 } 316 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 317 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, 318 IPSEC_ENC_AFTER_PFIL, ctx->af); 319 return (0); 320 } 321 322 static int 323 enc_add_hhooks(struct enc_softc *sc) 324 { 325 struct hookinfo hki; 326 int error; 327 328 error = EPFNOSUPPORT; 329 hki.hook_func = enc_hhook; 330 hki.hook_helper = NULL; 331 hki.hook_udata = sc; 332 #ifdef INET 333 hki.hook_id = AF_INET; 334 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 335 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 336 &hki, HHOOK_WAITOK); 337 if (error != 0) 338 return (error); 339 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 340 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 341 &hki, HHOOK_WAITOK); 342 if (error != 0) 343 return (error); 344 #endif 345 #ifdef INET6 346 hki.hook_id = AF_INET6; 347 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 348 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 349 &hki, HHOOK_WAITOK); 350 if (error != 0) 351 return (error); 352 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 353 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 354 &hki, HHOOK_WAITOK); 355 if (error != 0) 356 return (error); 357 #endif 358 return (error); 359 } 360 361 static void 362 enc_remove_hhooks(struct enc_softc *sc) 363 { 364 struct hookinfo hki; 365 366 hki.hook_func = enc_hhook; 367 hki.hook_helper = NULL; 368 hki.hook_udata = sc; 369 #ifdef INET 370 hki.hook_id = AF_INET; 371 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 372 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 373 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 374 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 375 #endif 376 #ifdef INET6 377 hki.hook_id = AF_INET6; 378 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 379 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 380 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 381 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 382 #endif 383 } 384 385 static void 386 vnet_enc_init(const void *unused __unused) 387 { 388 389 V_enc_sc = NULL; 390 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 391 enc_clone_destroy, 1); 392 } 393 VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 394 vnet_enc_init, NULL); 395 396 static void 397 vnet_enc_init_proto(void *unused __unused) 398 { 399 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 400 401 if (enc_add_hhooks(V_enc_sc) != 0) 402 enc_clone_destroy(V_enc_sc->sc_ifp); 403 } 404 VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 405 vnet_enc_init_proto, NULL); 406 407 static void 408 vnet_enc_uninit(const void *unused __unused) 409 { 410 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 411 412 if_clone_detach(V_enc_cloner); 413 } 414 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 415 vnet_enc_uninit, NULL); 416 417 /* 418 * The hhook consumer needs to go before ip[6]_destroy are called on 419 * SI_ORDER_THIRD. 420 */ 421 static void 422 vnet_enc_uninit_hhook(const void *unused __unused) 423 { 424 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 425 426 enc_remove_hhooks(V_enc_sc); 427 } 428 VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 429 vnet_enc_uninit_hhook, NULL); 430 431 static int 432 enc_modevent(module_t mod, int type, void *data) 433 { 434 435 switch (type) { 436 case MOD_LOAD: 437 case MOD_UNLOAD: 438 break; 439 default: 440 return (EOPNOTSUPP); 441 } 442 return (0); 443 } 444 445 static moduledata_t enc_mod = { 446 "if_enc", 447 enc_modevent, 448 0 449 }; 450 451 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 452 MODULE_VERSION(if_enc, 1); 453