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 /* 103 * Before and after are relative to when we are stripping the 104 * outer IP header. 105 */ 106 static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 107 static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 108 static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 109 static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 110 #define V_filter_mask_in VNET(filter_mask_in) 111 #define V_bpf_mask_in VNET(bpf_mask_in) 112 #define V_filter_mask_out VNET(filter_mask_out) 113 #define V_bpf_mask_out VNET(bpf_mask_out) 114 115 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 116 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 117 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 118 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 119 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 120 "IPsec input firewall filter mask"); 121 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 122 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 123 "IPsec input bpf mask"); 124 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 125 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 126 "IPsec output firewall filter mask"); 127 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 128 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 129 "IPsec output bpf mask"); 130 131 static void 132 enc_clone_destroy(struct ifnet *ifp) 133 { 134 struct enc_softc *sc; 135 136 sc = ifp->if_softc; 137 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 138 139 enc_remove_hhooks(sc); 140 bpfdetach(ifp); 141 if_detach(ifp); 142 if_free(ifp); 143 free(sc, M_DEVBUF); 144 V_enc_sc = NULL; 145 } 146 147 static int 148 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 149 { 150 struct ifnet *ifp; 151 struct enc_softc *sc; 152 153 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 154 M_WAITOK | M_ZERO); 155 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 156 if (ifp == NULL) { 157 free(sc, M_DEVBUF); 158 return (ENOSPC); 159 } 160 if (V_enc_sc != NULL) { 161 if_free(ifp); 162 free(sc, M_DEVBUF); 163 return (EEXIST); 164 } 165 V_enc_sc = sc; 166 if_initname(ifp, encname, unit); 167 ifp->if_mtu = ENCMTU; 168 ifp->if_ioctl = enc_ioctl; 169 ifp->if_output = enc_output; 170 ifp->if_softc = sc; 171 if_attach(ifp); 172 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 173 if (enc_add_hhooks(sc) != 0) { 174 enc_clone_destroy(ifp); 175 return (ENXIO); 176 } 177 return (0); 178 } 179 180 static int 181 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 182 struct route *ro) 183 { 184 185 m_freem(m); 186 return (0); 187 } 188 189 static int 190 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 191 { 192 193 if (cmd != SIOCSIFFLAGS) 194 return (EINVAL); 195 if (ifp->if_flags & IFF_UP) 196 ifp->if_drv_flags |= IFF_DRV_RUNNING; 197 else 198 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 199 return (0); 200 } 201 202 /* 203 * One helper hook function is used by any hook points. 204 * + from hhook_type we can determine the packet direction: 205 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 206 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 207 * + udata contains pointer to enc_softc; 208 * + ctx_data contains pointer to struct ipsec_ctx_data. 209 */ 210 static int 211 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 212 void *hdata, struct osd *hosd) 213 { 214 struct enchdr hdr; 215 struct ipsec_ctx_data *ctx; 216 struct enc_softc *sc; 217 struct ifnet *ifp, *rcvif; 218 struct pfil_head *ph; 219 int pdir; 220 221 sc = (struct enc_softc *)udata; 222 ifp = sc->sc_ifp; 223 if ((ifp->if_flags & IFF_UP) == 0) 224 return (0); 225 226 ctx = (struct ipsec_ctx_data *)ctx_data; 227 /* XXX: wrong hook point was used by caller? */ 228 if (ctx->af != hhook_id) 229 return (EPFNOSUPPORT); 230 231 if (((hhook_type == HHOOK_TYPE_IPSEC_IN && 232 (ctx->enc & V_bpf_mask_in) != 0) || 233 (hhook_type == HHOOK_TYPE_IPSEC_OUT && 234 (ctx->enc & V_bpf_mask_out) != 0)) && 235 bpf_peers_present(ifp->if_bpf) != 0) { 236 hdr.af = ctx->af; 237 hdr.spi = ctx->sav->spi; 238 hdr.flags = 0; 239 if (ctx->sav->alg_enc != SADB_EALG_NONE) 240 hdr.flags |= M_CONF; 241 if (ctx->sav->alg_auth != SADB_AALG_NONE) 242 hdr.flags |= M_AUTH; 243 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), *ctx->mp); 244 } 245 246 switch (hhook_type) { 247 case HHOOK_TYPE_IPSEC_IN: 248 if (ctx->enc == IPSEC_ENC_BEFORE) { 249 /* Do accounting only once */ 250 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 251 if_inc_counter(ifp, IFCOUNTER_IBYTES, 252 (*ctx->mp)->m_pkthdr.len); 253 } 254 if ((ctx->enc & V_filter_mask_in) == 0) 255 return (0); /* skip pfil processing */ 256 pdir = PFIL_IN; 257 break; 258 case HHOOK_TYPE_IPSEC_OUT: 259 if (ctx->enc == IPSEC_ENC_BEFORE) { 260 /* Do accounting only once */ 261 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 262 if_inc_counter(ifp, IFCOUNTER_OBYTES, 263 (*ctx->mp)->m_pkthdr.len); 264 } 265 if ((ctx->enc & V_filter_mask_out) == 0) 266 return (0); /* skip pfil processing */ 267 pdir = PFIL_OUT; 268 break; 269 default: 270 return (EINVAL); 271 } 272 273 switch (hhook_id) { 274 #ifdef INET 275 case AF_INET: 276 ph = &V_inet_pfil_hook; 277 break; 278 #endif 279 #ifdef INET6 280 case AF_INET6: 281 ph = &V_inet6_pfil_hook; 282 break; 283 #endif 284 default: 285 ph = NULL; 286 } 287 if (ph == NULL || !PFIL_HOOKED(ph)) 288 return (0); 289 /* Make a packet looks like it was received on enc(4) */ 290 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 291 (*ctx->mp)->m_pkthdr.rcvif = ifp; 292 if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, NULL) != 0 || 293 *ctx->mp == NULL) { 294 *ctx->mp = NULL; /* consumed by filter */ 295 return (EACCES); 296 } 297 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 298 return (0); 299 } 300 301 static int 302 enc_add_hhooks(struct enc_softc *sc) 303 { 304 struct hookinfo hki; 305 int error; 306 307 error = EPFNOSUPPORT; 308 hki.hook_func = enc_hhook; 309 hki.hook_helper = NULL; 310 hki.hook_udata = sc; 311 #ifdef INET 312 hki.hook_id = AF_INET; 313 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 314 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 315 &hki, HHOOK_WAITOK); 316 if (error != 0) 317 return (error); 318 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 319 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 320 &hki, HHOOK_WAITOK); 321 if (error != 0) 322 return (error); 323 #endif 324 #ifdef INET6 325 hki.hook_id = AF_INET6; 326 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 327 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 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_INET6], 333 &hki, HHOOK_WAITOK); 334 if (error != 0) 335 return (error); 336 #endif 337 return (error); 338 } 339 340 static void 341 enc_remove_hhooks(struct enc_softc *sc) 342 { 343 struct hookinfo hki; 344 345 hki.hook_func = enc_hhook; 346 hki.hook_helper = NULL; 347 hki.hook_udata = sc; 348 #ifdef INET 349 hki.hook_id = AF_INET; 350 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 351 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 352 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 353 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 354 #endif 355 #ifdef INET6 356 hki.hook_id = AF_INET6; 357 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 358 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 359 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 360 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 361 #endif 362 } 363 364 static void 365 vnet_enc_init(const void *unused __unused) 366 { 367 368 V_enc_sc = NULL; 369 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 370 enc_clone_destroy, 1); 371 } 372 VNET_SYSINIT(vnet_enc_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 373 vnet_enc_init, NULL); 374 375 static void 376 vnet_enc_uninit(const void *unused __unused) 377 { 378 379 if_clone_detach(V_enc_cloner); 380 } 381 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 382 vnet_enc_uninit, NULL); 383 384 static int 385 enc_modevent(module_t mod, int type, void *data) 386 { 387 388 switch (type) { 389 case MOD_LOAD: 390 case MOD_UNLOAD: 391 break; 392 default: 393 return (EOPNOTSUPP); 394 } 395 return (0); 396 } 397 398 static moduledata_t enc_mod = { 399 "if_enc", 400 enc_modevent, 401 0 402 }; 403 404 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 405