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: stable/11/sys/net/if_enc.c 365277 2020-09-02 20:36:33Z jhb $ 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_clone.h> 52#include <net/if_types.h> 53#include <net/pfil.h> 54#include <net/route.h> 55#include <net/netisr.h> 56#include <net/bpf.h> 57#include <net/vnet.h> 58 59#include <netinet/in.h> 60#include <netinet/in_systm.h> 61#include <netinet/ip.h> 62#include <netinet/ip_var.h> 63#include <netinet/in_var.h> 64 65#ifdef INET6 66#include <netinet/ip6.h> 67#include <netinet6/ip6_var.h> 68#endif 69 70#include <netipsec/ipsec.h> 71#include <netipsec/xform.h> 72 73#define ENCMTU (1024+512) 74 75/* XXX this define must have the same value as in OpenBSD */ 76#define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 77#define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 78#define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 79 80struct enchdr { 81 u_int32_t af; 82 u_int32_t spi; 83 u_int32_t flags; 84}; 85struct enc_softc { 86 struct ifnet *sc_ifp; 87}; 88static VNET_DEFINE(struct enc_softc *, enc_sc); 89#define V_enc_sc VNET(enc_sc) 90static VNET_DEFINE(struct if_clone *, enc_cloner); 91#define V_enc_cloner VNET(enc_cloner) 92 93static int enc_ioctl(struct ifnet *, u_long, caddr_t); 94static int enc_output(struct ifnet *, struct mbuf *, 95 const struct sockaddr *, struct route *); 96static int enc_clone_create(struct if_clone *, int, caddr_t); 97static void enc_clone_destroy(struct ifnet *); 98static int enc_add_hhooks(struct enc_softc *); 99static void enc_remove_hhooks(struct enc_softc *); 100 101static const char encname[] = "enc"; 102 103#define IPSEC_ENC_AFTER_PFIL 0x04 104/* 105 * Before and after are relative to when we are stripping the 106 * outer IP header. 107 * 108 * AFTER_PFIL flag used only for bpf_mask_*. It enables BPF capturing 109 * after PFIL hook execution. It might be useful when PFIL hook does 110 * some changes to the packet, e.g. address translation. If PFIL hook 111 * consumes mbuf, nothing will be captured. 112 */ 113static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 114static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 115static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 116static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 117#define V_filter_mask_in VNET(filter_mask_in) 118#define V_bpf_mask_in VNET(bpf_mask_in) 119#define V_filter_mask_out VNET(filter_mask_out) 120#define V_bpf_mask_out VNET(bpf_mask_out) 121 122static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 123static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 124static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 125SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 126 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 127 "IPsec input firewall filter mask"); 128SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 129 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 130 "IPsec input bpf mask"); 131SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 132 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 133 "IPsec output firewall filter mask"); 134SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 135 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 136 "IPsec output bpf mask"); 137 138static void 139enc_clone_destroy(struct ifnet *ifp) 140{ 141 struct enc_softc *sc; 142 143 sc = ifp->if_softc; 144 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 145 146 bpfdetach(ifp); 147 if_detach(ifp); 148 if_free(ifp); 149 free(sc, M_DEVBUF); 150 V_enc_sc = NULL; 151} 152 153static int 154enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 155{ 156 struct ifnet *ifp; 157 struct enc_softc *sc; 158 159 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 160 M_WAITOK | M_ZERO); 161 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 162 if (ifp == NULL) { 163 free(sc, M_DEVBUF); 164 return (ENOSPC); 165 } 166 if (V_enc_sc != NULL) { 167 if_free(ifp); 168 free(sc, M_DEVBUF); 169 return (EEXIST); 170 } 171 V_enc_sc = sc; 172 if_initname(ifp, encname, unit); 173 ifp->if_mtu = ENCMTU; 174 ifp->if_ioctl = enc_ioctl; 175 ifp->if_output = enc_output; 176 ifp->if_softc = sc; 177 if_attach(ifp); 178 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 179 return (0); 180} 181 182static int 183enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 184 struct route *ro) 185{ 186 187 m_freem(m); 188 return (0); 189} 190 191static int 192enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 193{ 194 195 if (cmd != SIOCSIFFLAGS) 196 return (EINVAL); 197 if (ifp->if_flags & IFF_UP) 198 ifp->if_drv_flags |= IFF_DRV_RUNNING; 199 else 200 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 201 return (0); 202} 203 204static void 205enc_bpftap(struct ifnet *ifp, struct mbuf *m, const struct secasvar *sav, 206 int32_t hhook_type, uint8_t enc, uint8_t af) 207{ 208 struct enchdr hdr; 209 210 if (hhook_type == HHOOK_TYPE_IPSEC_IN && 211 (enc & V_bpf_mask_in) == 0) 212 return; 213 else if (hhook_type == HHOOK_TYPE_IPSEC_OUT && 214 (enc & V_bpf_mask_out) == 0) 215 return; 216 if (bpf_peers_present(ifp->if_bpf) == 0) 217 return; 218 hdr.af = af; 219 hdr.spi = sav->spi; 220 hdr.flags = 0; 221 if (sav->alg_enc != SADB_EALG_NONE) 222 hdr.flags |= M_CONF; 223 if (sav->alg_auth != SADB_AALG_NONE) 224 hdr.flags |= M_AUTH; 225 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), m); 226} 227 228/* 229 * One helper hook function is used by any hook points. 230 * + from hhook_type we can determine the packet direction: 231 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 232 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 233 * + udata contains pointer to enc_softc; 234 * + ctx_data contains pointer to struct ipsec_ctx_data. 235 */ 236static int 237enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 238 void *hdata, struct osd *hosd) 239{ 240 struct ipsec_ctx_data *ctx; 241 struct enc_softc *sc; 242 struct ifnet *ifp, *rcvif; 243 struct pfil_head *ph; 244 int pdir; 245 246 sc = (struct enc_softc *)udata; 247 ifp = sc->sc_ifp; 248 if ((ifp->if_flags & IFF_UP) == 0) 249 return (0); 250 251 ctx = (struct ipsec_ctx_data *)ctx_data; 252 /* XXX: wrong hook point was used by caller? */ 253 if (ctx->af != hhook_id) 254 return (EPFNOSUPPORT); 255 256 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, ctx->enc, ctx->af); 257 switch (hhook_type) { 258 case HHOOK_TYPE_IPSEC_IN: 259 if (ctx->enc == IPSEC_ENC_BEFORE) { 260 /* Do accounting only once */ 261 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 262 if_inc_counter(ifp, IFCOUNTER_IBYTES, 263 (*ctx->mp)->m_pkthdr.len); 264 } 265 if ((ctx->enc & V_filter_mask_in) == 0) 266 return (0); /* skip pfil processing */ 267 pdir = PFIL_IN; 268 break; 269 case HHOOK_TYPE_IPSEC_OUT: 270 if (ctx->enc == IPSEC_ENC_BEFORE) { 271 /* Do accounting only once */ 272 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 273 if_inc_counter(ifp, IFCOUNTER_OBYTES, 274 (*ctx->mp)->m_pkthdr.len); 275 } 276 if ((ctx->enc & V_filter_mask_out) == 0) 277 return (0); /* skip pfil processing */ 278 pdir = PFIL_OUT; 279 break; 280 default: 281 return (EINVAL); 282 } 283 284 switch (hhook_id) { 285#ifdef INET 286 case AF_INET: 287 ph = &V_inet_pfil_hook; 288 break; 289#endif 290#ifdef INET6 291 case AF_INET6: 292 ph = &V_inet6_pfil_hook; 293 break; 294#endif 295 default: 296 ph = NULL; 297 } 298 if (ph == NULL || !PFIL_HOOKED(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 (pfil_run_hooks(ph, ctx->mp, ifp, pdir, 0, ctx->inp) != 0 || 304 *ctx->mp == NULL) { 305 *ctx->mp = NULL; /* consumed by filter */ 306 return (EACCES); 307 } 308 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 309 enc_bpftap(ifp, *ctx->mp, ctx->sav, hhook_type, 310 IPSEC_ENC_AFTER_PFIL, ctx->af); 311 return (0); 312} 313 314static int 315enc_add_hhooks(struct enc_softc *sc) 316{ 317 struct hookinfo hki; 318 int error; 319 320 error = EPFNOSUPPORT; 321 hki.hook_func = enc_hhook; 322 hki.hook_helper = NULL; 323 hki.hook_udata = sc; 324#ifdef INET 325 hki.hook_id = AF_INET; 326 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 327 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 328 &hki, HHOOK_WAITOK); 329 if (error != 0) 330 return (error); 331 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 332 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 333 &hki, HHOOK_WAITOK); 334 if (error != 0) 335 return (error); 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 if (error != 0) 343 return (error); 344 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 345 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 346 &hki, HHOOK_WAITOK); 347 if (error != 0) 348 return (error); 349#endif 350 return (error); 351} 352 353static void 354enc_remove_hhooks(struct enc_softc *sc) 355{ 356 struct hookinfo hki; 357 358 hki.hook_func = enc_hhook; 359 hki.hook_helper = NULL; 360 hki.hook_udata = sc; 361#ifdef INET 362 hki.hook_id = AF_INET; 363 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 364 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 365 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 366 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 367#endif 368#ifdef INET6 369 hki.hook_id = AF_INET6; 370 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 371 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 372 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 373 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 374#endif 375} 376 377static void 378vnet_enc_init(const void *unused __unused) 379{ 380 381 V_enc_sc = NULL; 382 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 383 enc_clone_destroy, 1); 384} 385VNET_SYSINIT(vnet_enc_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 386 vnet_enc_init, NULL); 387 388static void 389vnet_enc_init_proto(void *unused __unused) 390{ 391 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 392 393 if (enc_add_hhooks(V_enc_sc) != 0) 394 enc_clone_destroy(V_enc_sc->sc_ifp); 395} 396VNET_SYSINIT(vnet_enc_init_proto, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 397 vnet_enc_init_proto, NULL); 398 399static void 400vnet_enc_uninit(const void *unused __unused) 401{ 402 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 403 404 if_clone_detach(V_enc_cloner); 405} 406VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, 407 vnet_enc_uninit, NULL); 408 409/* 410 * The hhook consumer needs to go before ip[6]_destroy are called on 411 * SI_ORDER_THIRD. 412 */ 413static void 414vnet_enc_uninit_hhook(const void *unused __unused) 415{ 416 KASSERT(V_enc_sc != NULL, ("%s: V_enc_sc is %p\n", __func__, V_enc_sc)); 417 418 enc_remove_hhooks(V_enc_sc); 419} 420VNET_SYSUNINIT(vnet_enc_uninit_hhook, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 421 vnet_enc_uninit_hhook, NULL); 422 423static int 424enc_modevent(module_t mod, int type, void *data) 425{ 426 427 switch (type) { 428 case MOD_LOAD: 429 case MOD_UNLOAD: 430 break; 431 default: 432 return (EOPNOTSUPP); 433 } 434 return (0); 435} 436 437static moduledata_t enc_mod = { 438 "if_enc", 439 enc_modevent, 440 0 441}; 442 443DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 444MODULE_VERSION(if_enc, 1); 445