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 *, char *, size_t, 98 struct ifc_data *, struct ifnet **); 99 static int enc_clone_destroy(struct if_clone *, struct ifnet *, uint32_t); 100 static void enc_add_hhooks(struct enc_softc *); 101 static void enc_remove_hhooks(struct enc_softc *); 102 103 static const char encname[] = "enc"; 104 105 #define IPSEC_ENC_AFTER_PFIL 0x04 106 /* 107 * Before and after are relative to when we are stripping the 108 * outer IP header. 109 * 110 * AFTER_PFIL flag used only for bpf_mask_*. It enables BPF capturing 111 * after PFIL hook execution. It might be useful when PFIL hook does 112 * some changes to the packet, e.g. address translation. If PFIL hook 113 * consumes mbuf, nothing will be captured. 114 */ 115 VNET_DEFINE_STATIC(int, filter_mask_in) = IPSEC_ENC_BEFORE; 116 VNET_DEFINE_STATIC(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 117 VNET_DEFINE_STATIC(int, filter_mask_out) = IPSEC_ENC_BEFORE; 118 VNET_DEFINE_STATIC(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 119 #define V_filter_mask_in VNET(filter_mask_in) 120 #define V_bpf_mask_in VNET(bpf_mask_in) 121 #define V_filter_mask_out VNET(filter_mask_out) 122 #define V_bpf_mask_out VNET(bpf_mask_out) 123 124 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 125 "enc sysctl"); 126 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 127 "enc input sysctl"); 128 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 129 "enc output sysctl"); 130 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 131 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 132 "IPsec input firewall filter mask"); 133 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 134 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 135 "IPsec input bpf mask"); 136 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 137 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 138 "IPsec output firewall filter mask"); 139 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 140 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 141 "IPsec output bpf mask"); 142 143 static int 144 enc_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 145 { 146 struct enc_softc *sc; 147 148 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 149 return (EINVAL); 150 151 sc = ifp->if_softc; 152 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 153 154 bpfdetach(ifp); 155 if_detach(ifp); 156 if_free(ifp); 157 free(sc, M_DEVBUF); 158 return (0); 159 } 160 161 static int 162 enc_clone_create(struct if_clone *ifc, char *name, size_t len, 163 struct ifc_data *ifd, struct ifnet **ifpp) 164 { 165 struct ifnet *ifp; 166 struct enc_softc *sc; 167 168 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, M_WAITOK | M_ZERO); 169 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 170 if_initname(ifp, encname, ifd->unit); 171 ifp->if_mtu = ENCMTU; 172 ifp->if_ioctl = enc_ioctl; 173 ifp->if_output = enc_output; 174 ifp->if_softc = sc; 175 if_attach(ifp); 176 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 177 *ifpp = ifp; 178 return (0); 179 } 180 181 static int 182 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 183 struct route *ro) 184 { 185 186 m_freem(m); 187 return (0); 188 } 189 190 static int 191 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 192 { 193 194 if (cmd != SIOCSIFFLAGS) 195 return (EINVAL); 196 if (ifp->if_flags & IFF_UP) 197 ifp->if_drv_flags |= IFF_DRV_RUNNING; 198 else 199 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 200 return (0); 201 } 202 203 static void 204 enc_bpftap(struct ifnet *ifp, struct mbuf *m, const struct secasvar *sav, 205 int32_t hhook_type, uint8_t enc, uint8_t af) 206 { 207 struct enchdr hdr; 208 209 if (hhook_type == HHOOK_TYPE_IPSEC_IN && 210 (enc & V_bpf_mask_in) == 0) 211 return; 212 else if (hhook_type == HHOOK_TYPE_IPSEC_OUT && 213 (enc & V_bpf_mask_out) == 0) 214 return; 215 if (!bpf_peers_present(ifp->if_bpf)) 216 return; 217 hdr.af = af; 218 hdr.spi = sav->spi; 219 hdr.flags = 0; 220 if (sav->alg_enc != SADB_EALG_NONE) 221 hdr.flags |= M_CONF; 222 if (sav->alg_auth != SADB_AALG_NONE) 223 hdr.flags |= M_AUTH; 224 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), m); 225 } 226 227 /* 228 * One helper hook function is used by any hook points. 229 * + from hhook_type we can determine the packet direction: 230 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 231 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 232 * + udata contains pointer to enc_softc; 233 * + ctx_data contains pointer to struct ipsec_ctx_data. 234 */ 235 static int 236 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 237 void *hdata, struct osd *hosd) 238 { 239 struct ipsec_ctx_data *ctx; 240 struct enc_softc *sc; 241 struct ifnet *ifp, *rcvif; 242 struct pfil_head *ph; 243 int pdir, ret; 244 245 sc = (struct enc_softc *)udata; 246 ifp = sc->sc_ifp; 247 if ((ifp->if_flags & IFF_UP) == 0) 248 return (0); 249 250 ctx = (struct ipsec_ctx_data *)ctx_data; 251 /* XXX: wrong hook point was used by caller? */ 252 if (ctx->af != hhook_id) 253 return (EPFNOSUPPORT); 254 255 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, ctx->enc, ctx->af); 256 switch (hhook_type) { 257 case HHOOK_TYPE_IPSEC_IN: 258 if (ctx->enc == IPSEC_ENC_BEFORE) { 259 /* Do accounting only once */ 260 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 261 if_inc_counter(ifp, IFCOUNTER_IBYTES, 262 (*ctx->mp)->m_pkthdr.len); 263 } 264 if ((ctx->enc & V_filter_mask_in) == 0) 265 return (0); /* skip pfil processing */ 266 pdir = PFIL_IN; 267 break; 268 case HHOOK_TYPE_IPSEC_OUT: 269 if (ctx->enc == IPSEC_ENC_BEFORE) { 270 /* Do accounting only once */ 271 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 272 if_inc_counter(ifp, IFCOUNTER_OBYTES, 273 (*ctx->mp)->m_pkthdr.len); 274 } 275 if ((ctx->enc & V_filter_mask_out) == 0) 276 return (0); /* skip pfil processing */ 277 pdir = PFIL_OUT; 278 break; 279 default: 280 return (EINVAL); 281 } 282 283 switch (hhook_id) { 284 #ifdef INET 285 case AF_INET: 286 ph = V_inet_pfil_head; 287 break; 288 #endif 289 #ifdef INET6 290 case AF_INET6: 291 ph = V_inet6_pfil_head; 292 break; 293 #endif 294 default: 295 ph = NULL; 296 } 297 if (ph == NULL || (pdir == PFIL_OUT && !PFIL_HOOKED_OUT(ph)) || 298 (pdir == PFIL_IN && !PFIL_HOOKED_IN(ph))) 299 return (0); 300 /* Make a packet looks like it was received on enc(4) */ 301 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 302 (*ctx->mp)->m_pkthdr.rcvif = ifp; 303 if (pdir == PFIL_IN) 304 ret = pfil_mbuf_in(ph, ctx->mp, ifp, ctx->inp); 305 else 306 ret = pfil_mbuf_out(ph, ctx->mp, ifp, ctx->inp); 307 if (ret != PFIL_PASS) { 308 *ctx->mp = NULL; /* consumed by filter */ 309 return (EACCES); 310 } 311 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 312 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, 313 IPSEC_ENC_AFTER_PFIL, ctx->af); 314 return (0); 315 } 316 317 static void 318 enc_add_hhooks(struct enc_softc *sc) 319 { 320 struct hookinfo hki; 321 int error __diagused; 322 323 hki.hook_func = enc_hhook; 324 hki.hook_helper = NULL; 325 hki.hook_udata = sc; 326 #ifdef INET 327 hki.hook_id = AF_INET; 328 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 329 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 330 &hki, HHOOK_WAITOK); 331 MPASS(error == 0); 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 MPASS(error == 0); 336 #endif 337 #ifdef INET6 338 hki.hook_id = AF_INET6; 339 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 340 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 341 &hki, HHOOK_WAITOK); 342 MPASS(error == 0); 343 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 344 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 345 &hki, HHOOK_WAITOK); 346 MPASS(error == 0); 347 #endif 348 } 349 350 static void 351 enc_remove_hhooks(struct enc_softc *sc) 352 { 353 struct hookinfo hki; 354 355 hki.hook_func = enc_hhook; 356 hki.hook_helper = NULL; 357 hki.hook_udata = sc; 358 #ifdef INET 359 hki.hook_id = AF_INET; 360 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 361 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 362 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 363 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 364 #endif 365 #ifdef INET6 366 hki.hook_id = AF_INET6; 367 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 368 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 369 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 370 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 371 #endif 372 } 373 374 static void 375 vnet_enc_init(const void *unused __unused) 376 { 377 struct ifnet *ifp; 378 379 struct if_clone_addreq req = { 380 .create_f = enc_clone_create, 381 .destroy_f = enc_clone_destroy, 382 .flags = IFC_F_AUTOUNIT | IFC_F_LIMITUNIT, 383 .maxunit = 0, 384 }; 385 V_enc_cloner = ifc_attach_cloner(encname, &req); 386 struct ifc_data ifd = { .unit = 0 }; 387 ifc_create_ifp(encname, &ifd, &ifp); 388 V_enc_sc = ifp->if_softc; 389 } 390 VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 391 vnet_enc_init, NULL); 392 393 static void 394 vnet_enc_init_proto(void *unused __unused) 395 { 396 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 397 398 enc_add_hhooks(V_enc_sc); 399 } 400 VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 401 vnet_enc_init_proto, NULL); 402 403 static void 404 vnet_enc_uninit(const void *unused __unused) 405 { 406 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 407 408 ifc_detach_cloner(V_enc_cloner); 409 V_enc_sc = NULL; 410 } 411 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 412 vnet_enc_uninit, NULL); 413 414 /* 415 * The hhook consumer needs to go before ip[6]_destroy are called on 416 * SI_ORDER_THIRD. 417 */ 418 static void 419 vnet_enc_uninit_hhook(const void *unused __unused) 420 { 421 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 422 423 enc_remove_hhooks(V_enc_sc); 424 } 425 VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 426 vnet_enc_uninit_hhook, NULL); 427 428 static int 429 enc_modevent(module_t mod, int type, void *data) 430 { 431 432 switch (type) { 433 case MOD_LOAD: 434 case MOD_UNLOAD: 435 break; 436 default: 437 return (EOPNOTSUPP); 438 } 439 return (0); 440 } 441 442 static moduledata_t enc_mod = { 443 "if_enc", 444 enc_modevent, 445 0 446 }; 447 448 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 449 MODULE_VERSION(if_enc, 1); 450