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 #define IPSEC_ENC_AFTER_PFIL 0x04 103 /* 104 * Before and after are relative to when we are stripping the 105 * outer IP header. 106 * 107 * AFTER_PFIL flag used only for bpf_mask_*. It enables BPF capturing 108 * after PFIL hook execution. It might be useful when PFIL hook does 109 * some changes to the packet, e.g. address translation. If PFIL hook 110 * consumes mbuf, nothing will be captured. 111 */ 112 static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 113 static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 114 static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 115 static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 116 #define V_filter_mask_in VNET(filter_mask_in) 117 #define V_bpf_mask_in VNET(bpf_mask_in) 118 #define V_filter_mask_out VNET(filter_mask_out) 119 #define V_bpf_mask_out VNET(bpf_mask_out) 120 121 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 122 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 123 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 124 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 125 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 126 "IPsec input firewall filter mask"); 127 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 128 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 129 "IPsec input bpf mask"); 130 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 131 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 132 "IPsec output firewall filter mask"); 133 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 134 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 135 "IPsec output bpf mask"); 136 137 static void 138 enc_clone_destroy(struct ifnet *ifp) 139 { 140 struct enc_softc *sc; 141 142 sc = ifp->if_softc; 143 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 144 145 bpfdetach(ifp); 146 if_detach(ifp); 147 if_free(ifp); 148 free(sc, M_DEVBUF); 149 V_enc_sc = NULL; 150 } 151 152 static int 153 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 154 { 155 struct ifnet *ifp; 156 struct enc_softc *sc; 157 158 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 159 M_WAITOK | M_ZERO); 160 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 161 if (ifp == NULL) { 162 free(sc, M_DEVBUF); 163 return (ENOSPC); 164 } 165 if (V_enc_sc != NULL) { 166 if_free(ifp); 167 free(sc, M_DEVBUF); 168 return (EEXIST); 169 } 170 V_enc_sc = sc; 171 if_initname(ifp, encname, unit); 172 ifp->if_mtu = ENCMTU; 173 ifp->if_ioctl = enc_ioctl; 174 ifp->if_output = enc_output; 175 ifp->if_softc = sc; 176 if_attach(ifp); 177 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 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) == 0) 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; 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_hook; 287 break; 288 #endif 289 #ifdef INET6 290 case AF_INET6: 291 ph = &V_inet6_pfil_hook; 292 break; 293 #endif 294 default: 295 ph = NULL; 296 } 297 if (ph == NULL || !PFIL_HOOKED(ph)) 298 return (0); 299 /* Make a packet looks like it was received on enc(4) */ 300 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 301 (*ctx->mp)->m_pkthdr.rcvif = ifp; 302 if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, ctx->inp) != 0 || 303 *ctx->mp == NULL) { 304 *ctx->mp = NULL; /* consumed by filter */ 305 return (EACCES); 306 } 307 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 308 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, 309 IPSEC_ENC_AFTER_PFIL, ctx->af); 310 return (0); 311 } 312 313 static int 314 enc_add_hhooks(struct enc_softc *sc) 315 { 316 struct hookinfo hki; 317 int error; 318 319 error = EPFNOSUPPORT; 320 hki.hook_func = enc_hhook; 321 hki.hook_helper = NULL; 322 hki.hook_udata = sc; 323 #ifdef INET 324 hki.hook_id = AF_INET; 325 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 326 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 327 &hki, HHOOK_WAITOK); 328 if (error != 0) 329 return (error); 330 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 331 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 332 &hki, HHOOK_WAITOK); 333 if (error != 0) 334 return (error); 335 #endif 336 #ifdef INET6 337 hki.hook_id = AF_INET6; 338 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 339 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 340 &hki, HHOOK_WAITOK); 341 if (error != 0) 342 return (error); 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 if (error != 0) 347 return (error); 348 #endif 349 return (error); 350 } 351 352 static void 353 enc_remove_hhooks(struct enc_softc *sc) 354 { 355 struct hookinfo hki; 356 357 hki.hook_func = enc_hhook; 358 hki.hook_helper = NULL; 359 hki.hook_udata = sc; 360 #ifdef INET 361 hki.hook_id = AF_INET; 362 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 363 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 364 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 365 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 366 #endif 367 #ifdef INET6 368 hki.hook_id = AF_INET6; 369 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 370 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 371 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 372 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 373 #endif 374 } 375 376 static void 377 vnet_enc_init(const void *unused __unused) 378 { 379 380 V_enc_sc = NULL; 381 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 382 enc_clone_destroy, 1); 383 } 384 VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 385 vnet_enc_init, NULL); 386 387 static void 388 vnet_enc_init_proto(void *unused __unused) 389 { 390 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 391 392 if (enc_add_hhooks(V_enc_sc) != 0) 393 enc_clone_destroy(V_enc_sc->sc_ifp); 394 } 395 VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 396 vnet_enc_init_proto, NULL); 397 398 static void 399 vnet_enc_uninit(const void *unused __unused) 400 { 401 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 402 403 if_clone_detach(V_enc_cloner); 404 } 405 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 406 vnet_enc_uninit, NULL); 407 408 /* 409 * The hhook consumer needs to go before ip[6]_destroy are called on 410 * SI_ORDER_THIRD. 411 */ 412 static void 413 vnet_enc_uninit_hhook(const void *unused __unused) 414 { 415 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 416 417 enc_remove_hhooks(V_enc_sc); 418 } 419 VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 420 vnet_enc_uninit_hhook, NULL); 421 422 static int 423 enc_modevent(module_t mod, int type, void *data) 424 { 425 426 switch (type) { 427 case MOD_LOAD: 428 case MOD_UNLOAD: 429 break; 430 default: 431 return (EOPNOTSUPP); 432 } 433 return (0); 434 } 435 436 static moduledata_t enc_mod = { 437 "if_enc", 438 enc_modevent, 439 0 440 }; 441 442 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 443 MODULE_VERSION(if_enc, 1); 444