1 /*- 2 * Copyright (c) 2006 The FreeBSD Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 #include "opt_enc.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/mbuf.h> 39 #include <sys/module.h> 40 #include <machine/bus.h> 41 #include <sys/rman.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/sysctl.h> 45 46 #include <net/if.h> 47 #include <net/if_clone.h> 48 #include <net/if_types.h> 49 #include <net/pfil.h> 50 #include <net/route.h> 51 #include <net/netisr.h> 52 #include <net/bpf.h> 53 #include <net/vnet.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/ip.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in_var.h> 60 61 #ifdef INET6 62 #include <netinet/ip6.h> 63 #include <netinet6/ip6_var.h> 64 #endif 65 66 #include <netipsec/ipsec.h> 67 #include <netipsec/xform.h> 68 69 #define ENCMTU (1024+512) 70 71 /* XXX this define must have the same value as in OpenBSD */ 72 #define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 73 #define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 74 #define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 75 76 struct enchdr { 77 u_int32_t af; 78 u_int32_t spi; 79 u_int32_t flags; 80 }; 81 82 struct ifnet *encif; 83 static struct mtx enc_mtx; 84 85 struct enc_softc { 86 struct ifnet *sc_ifp; 87 }; 88 89 static int enc_ioctl(struct ifnet *, u_long, caddr_t); 90 static int enc_output(struct ifnet *ifp, struct mbuf *m, 91 struct sockaddr *dst, struct route *ro); 92 static int enc_clone_create(struct if_clone *, int, caddr_t); 93 static void enc_clone_destroy(struct ifnet *); 94 static struct if_clone *enc_cloner; 95 static const char encname[] = "enc"; 96 97 /* 98 * Sysctls. 99 */ 100 101 /* 102 * Before and after are relative to when we are stripping the 103 * outer IP header. 104 */ 105 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 106 107 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 108 static int ipsec_filter_mask_in = ENC_BEFORE; 109 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, CTLFLAG_RW, 110 &ipsec_filter_mask_in, 0, "IPsec input firewall filter mask"); 111 static int ipsec_bpf_mask_in = ENC_BEFORE; 112 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, CTLFLAG_RW, 113 &ipsec_bpf_mask_in, 0, "IPsec input bpf mask"); 114 115 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 116 static int ipsec_filter_mask_out = ENC_BEFORE; 117 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, CTLFLAG_RW, 118 &ipsec_filter_mask_out, 0, "IPsec output firewall filter mask"); 119 static int ipsec_bpf_mask_out = ENC_BEFORE|ENC_AFTER; 120 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, CTLFLAG_RW, 121 &ipsec_bpf_mask_out, 0, "IPsec output bpf mask"); 122 123 static void 124 enc_clone_destroy(struct ifnet *ifp) 125 { 126 KASSERT(ifp != encif, ("%s: destroying encif", __func__)); 127 128 bpfdetach(ifp); 129 if_detach(ifp); 130 if_free(ifp); 131 } 132 133 static int 134 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 135 { 136 struct ifnet *ifp; 137 struct enc_softc *sc; 138 139 sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO); 140 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 141 if (ifp == NULL) { 142 free(sc, M_DEVBUF); 143 return (ENOSPC); 144 } 145 146 if_initname(ifp, encname, unit); 147 ifp->if_mtu = ENCMTU; 148 ifp->if_ioctl = enc_ioctl; 149 ifp->if_output = enc_output; 150 ifp->if_snd.ifq_maxlen = ifqmaxlen; 151 ifp->if_softc = sc; 152 if_attach(ifp); 153 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 154 155 mtx_lock(&enc_mtx); 156 /* grab a pointer to enc0, ignore the rest */ 157 if (encif == NULL) 158 encif = ifp; 159 mtx_unlock(&enc_mtx); 160 161 return (0); 162 } 163 164 static int 165 enc_modevent(module_t mod, int type, void *data) 166 { 167 switch (type) { 168 case MOD_LOAD: 169 mtx_init(&enc_mtx, "enc mtx", NULL, MTX_DEF); 170 enc_cloner = if_clone_simple(encname, enc_clone_create, 171 enc_clone_destroy, 0); 172 break; 173 case MOD_UNLOAD: 174 printf("enc module unload - not possible for this module\n"); 175 return (EINVAL); 176 default: 177 return (EOPNOTSUPP); 178 } 179 return (0); 180 } 181 182 static moduledata_t enc_mod = { 183 "if_enc", 184 enc_modevent, 185 0 186 }; 187 188 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 189 190 static int 191 enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 192 struct route *ro) 193 { 194 m_freem(m); 195 return (0); 196 } 197 198 /* 199 * Process an ioctl request. 200 */ 201 /* ARGSUSED */ 202 static int 203 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 204 { 205 int error = 0; 206 207 mtx_lock(&enc_mtx); 208 209 switch (cmd) { 210 211 case SIOCSIFFLAGS: 212 if (ifp->if_flags & IFF_UP) 213 ifp->if_drv_flags |= IFF_DRV_RUNNING; 214 else 215 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 216 217 break; 218 219 default: 220 error = EINVAL; 221 } 222 223 mtx_unlock(&enc_mtx); 224 return (error); 225 } 226 227 int 228 ipsec_filter(struct mbuf **mp, int dir, int flags) 229 { 230 int error, i; 231 struct ip *ip; 232 233 KASSERT(encif != NULL, ("%s: encif is null", __func__)); 234 KASSERT(flags & (ENC_IN|ENC_OUT), 235 ("%s: invalid flags: %04x", __func__, flags)); 236 237 if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0) 238 return (0); 239 240 if (flags & ENC_IN) { 241 if ((flags & ipsec_filter_mask_in) == 0) 242 return (0); 243 } else { 244 if ((flags & ipsec_filter_mask_out) == 0) 245 return (0); 246 } 247 248 /* Skip pfil(9) if no filters are loaded */ 249 if (1 250 #ifdef INET 251 && !PFIL_HOOKED(&V_inet_pfil_hook) 252 #endif 253 #ifdef INET6 254 && !PFIL_HOOKED(&V_inet6_pfil_hook) 255 #endif 256 ) { 257 return (0); 258 } 259 260 i = min((*mp)->m_pkthdr.len, max_protohdr); 261 if ((*mp)->m_len < i) { 262 *mp = m_pullup(*mp, i); 263 if (*mp == NULL) { 264 printf("%s: m_pullup failed\n", __func__); 265 return (-1); 266 } 267 } 268 269 error = 0; 270 ip = mtod(*mp, struct ip *); 271 switch (ip->ip_v) { 272 #ifdef INET 273 case 4: 274 error = pfil_run_hooks(&V_inet_pfil_hook, mp, 275 encif, dir, NULL); 276 break; 277 #endif 278 #ifdef INET6 279 case 6: 280 error = pfil_run_hooks(&V_inet6_pfil_hook, mp, 281 encif, dir, NULL); 282 break; 283 #endif 284 default: 285 printf("%s: unknown IP version\n", __func__); 286 } 287 288 /* 289 * If the mbuf was consumed by the filter for requeueing (dummynet, etc) 290 * then error will be zero but we still want to return an error to our 291 * caller so the null mbuf isn't forwarded further. 292 */ 293 if (*mp == NULL && error == 0) 294 return (-1); /* Consumed by the filter */ 295 if (*mp == NULL) 296 return (error); 297 if (error != 0) 298 goto bad; 299 300 return (error); 301 302 bad: 303 m_freem(*mp); 304 *mp = NULL; 305 return (error); 306 } 307 308 void 309 ipsec_bpf(struct mbuf *m, struct secasvar *sav, int af, int flags) 310 { 311 int mflags; 312 struct enchdr hdr; 313 314 KASSERT(encif != NULL, ("%s: encif is null", __func__)); 315 KASSERT(flags & (ENC_IN|ENC_OUT), 316 ("%s: invalid flags: %04x", __func__, flags)); 317 318 if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0) 319 return; 320 321 if (flags & ENC_IN) { 322 if ((flags & ipsec_bpf_mask_in) == 0) 323 return; 324 } else { 325 if ((flags & ipsec_bpf_mask_out) == 0) 326 return; 327 } 328 329 if (bpf_peers_present(encif->if_bpf)) { 330 mflags = 0; 331 hdr.spi = 0; 332 if (!sav) { 333 struct m_tag *mtag; 334 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 335 if (mtag != NULL) { 336 struct tdb_ident *tdbi; 337 tdbi = (struct tdb_ident *) (mtag + 1); 338 if (tdbi->alg_enc != SADB_EALG_NONE) 339 mflags |= M_CONF; 340 if (tdbi->alg_auth != SADB_AALG_NONE) 341 mflags |= M_AUTH; 342 hdr.spi = tdbi->spi; 343 } 344 } else { 345 if (sav->alg_enc != SADB_EALG_NONE) 346 mflags |= M_CONF; 347 if (sav->alg_auth != SADB_AALG_NONE) 348 mflags |= M_AUTH; 349 hdr.spi = sav->spi; 350 } 351 352 /* 353 * We need to prepend the address family as a four byte 354 * field. Cons up a dummy header to pacify bpf. This 355 * is safe because bpf will only read from the mbuf 356 * (i.e., it won't try to free it or keep a pointer a 357 * to it). 358 */ 359 hdr.af = af; 360 /* hdr.spi already set above */ 361 hdr.flags = mflags; 362 363 bpf_mtap2(encif->if_bpf, &hdr, sizeof(hdr), m); 364 } 365 } 366