1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2009-2010 Ana Kukec <anchie@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 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 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/malloc.h> 35 #include <sys/mbuf.h> 36 #include <sys/module.h> 37 #include <sys/priv.h> 38 #include <sys/protosw.h> 39 #include <sys/sdt.h> 40 #include <sys/systm.h> 41 #include <sys/socket.h> 42 #include <sys/sockbuf.h> 43 #include <sys/socketvar.h> 44 #include <sys/types.h> 45 46 #include <net/route.h> 47 #include <net/if.h> 48 #include <net/if_var.h> 49 #include <net/if_private.h> 50 #include <net/vnet.h> 51 52 #include <netinet/in.h> 53 #include <netinet/in_kdtrace.h> 54 #include <netinet/ip_var.h> 55 #include <netinet/ip6.h> 56 #include <netinet/icmp6.h> 57 58 #include <netinet6/in6_var.h> 59 #include <netinet6/nd6.h> 60 #include <netinet6/scope6_var.h> 61 #include <netinet6/send.h> 62 63 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery"); 64 65 /* 66 * The socket used to communicate with the SeND daemon. 67 */ 68 VNET_DEFINE_STATIC(struct socket *, send_so); 69 #define V_send_so VNET(send_so) 70 71 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send)); 72 u_long send_recvspace = 9216; 73 74 struct mtx send_mtx; 75 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF) 76 #define SEND_LOCK() mtx_lock(&send_mtx) 77 #define SEND_UNLOCK() mtx_unlock(&send_mtx) 78 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx) 79 80 static int 81 send_attach(struct socket *so, int proto, struct thread *td) 82 { 83 int error; 84 85 SEND_LOCK(); 86 if (V_send_so != NULL) { 87 SEND_UNLOCK(); 88 return (EEXIST); 89 } 90 91 error = priv_check(td, PRIV_NETINET_RAW); 92 if (error) { 93 SEND_UNLOCK(); 94 return(error); 95 } 96 97 if (proto != IPPROTO_SEND) { 98 SEND_UNLOCK(); 99 return (EPROTONOSUPPORT); 100 } 101 error = soreserve(so, send_sendspace, send_recvspace); 102 if (error) { 103 SEND_UNLOCK(); 104 return(error); 105 } 106 107 V_send_so = so; 108 SEND_UNLOCK(); 109 110 return (0); 111 } 112 113 static int 114 send_output(struct mbuf *m, struct ifnet *ifp, int direction) 115 { 116 struct ip6_hdr *ip6; 117 struct sockaddr_in6 dst; 118 struct icmp6_hdr *icmp6; 119 struct epoch_tracker et; 120 int icmp6len; 121 int error; 122 123 /* 124 * Receive incoming (SeND-protected) or outgoing traffic 125 * (SeND-validated) from the SeND user space application. 126 */ 127 128 switch (direction) { 129 case SND_IN: 130 if (m->m_len < (sizeof(struct ip6_hdr) + 131 sizeof(struct icmp6_hdr))) { 132 m = m_pullup(m, sizeof(struct ip6_hdr) + 133 sizeof(struct icmp6_hdr)); 134 if (!m) 135 return (ENOBUFS); 136 } 137 138 /* Before passing off the mbuf record the proper interface. */ 139 m->m_pkthdr.rcvif = ifp; 140 141 if (m->m_flags & M_PKTHDR) 142 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 143 else 144 panic("Doh! not the first mbuf."); 145 146 ip6 = mtod(m, struct ip6_hdr *); 147 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 148 error = 0; 149 150 /* 151 * Output the packet as icmp6.c:icpm6_input() would do. 152 * The mbuf is always consumed, so we do not have to 153 * care about that. 154 */ 155 NET_EPOCH_ENTER(et); 156 switch (icmp6->icmp6_type) { 157 case ND_NEIGHBOR_SOLICIT: 158 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 159 break; 160 case ND_NEIGHBOR_ADVERT: 161 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 162 break; 163 case ND_REDIRECT: 164 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 165 break; 166 case ND_ROUTER_SOLICIT: 167 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 168 break; 169 case ND_ROUTER_ADVERT: 170 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 171 break; 172 default: 173 m_freem(m); 174 error = ENOSYS; 175 } 176 NET_EPOCH_EXIT(et); 177 178 return (error); 179 180 case SND_OUT: 181 if (m->m_len < sizeof(struct ip6_hdr)) { 182 m = m_pullup(m, sizeof(struct ip6_hdr)); 183 if (!m) 184 return (ENOBUFS); 185 } 186 ip6 = mtod(m, struct ip6_hdr *); 187 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 188 m->m_flags |= M_MCAST; 189 190 bzero(&dst, sizeof(dst)); 191 dst.sin6_family = AF_INET6; 192 dst.sin6_len = sizeof(dst); 193 dst.sin6_addr = ip6->ip6_dst; 194 195 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 196 197 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 198 199 /* 200 * Output the packet as nd6.c:nd6_output_lle() would do. 201 * The mbuf is always consumed, so we do not have to care 202 * about that. 203 * XXX-BZ as we added data, what about fragmenting, 204 * if now needed? 205 */ 206 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 207 NULL)); 208 if (error) 209 error = ENOENT; 210 return (error); 211 212 default: 213 panic("%s: direction %d neither SND_IN nor SND_OUT.", 214 __func__, direction); 215 } 216 } 217 218 /* 219 * Receive a SeND message from user space to be either send out by the kernel 220 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 221 * input path. 222 */ 223 static int 224 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 225 struct mbuf *control, struct thread *td) 226 { 227 struct sockaddr_send *sendsrc; 228 struct ifnet *ifp; 229 int error; 230 231 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 232 __func__, so, V_send_so)); 233 234 sendsrc = (struct sockaddr_send *)nam; 235 if (sendsrc->send_family != AF_INET6) { 236 error = EAFNOSUPPORT; 237 goto err; 238 } 239 if (sendsrc->send_len != sizeof(*sendsrc)) { 240 error = EINVAL; 241 goto err; 242 } 243 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 244 if (ifp == NULL) { 245 error = ENETUNREACH; 246 goto err; 247 } 248 249 error = send_output(m, ifp, sendsrc->send_direction); 250 if_rele(ifp); 251 m = NULL; 252 253 err: 254 if (control != NULL) 255 m_freem(control); 256 if (m != NULL) 257 m_freem(m); 258 259 return (error); 260 } 261 262 static void 263 send_close(struct socket *so) 264 { 265 266 SEND_LOCK(); 267 if (V_send_so) 268 V_send_so = NULL; 269 SEND_UNLOCK(); 270 } 271 272 /* 273 * Send a SeND message to user space, that was either received and has to be 274 * validated or was about to be send out and has to be handled by the SEND 275 * daemon adding SeND ICMPv6 options. 276 */ 277 static int 278 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 279 { 280 struct ip6_hdr *ip6; 281 struct sockaddr_send sendsrc; 282 283 SEND_LOCK(); 284 if (V_send_so == NULL) { 285 SEND_UNLOCK(); 286 return (-1); 287 } 288 289 /* 290 * Make sure to clear any possible internally embedded scope before 291 * passing the packet to user space for SeND cryptographic signature 292 * validation to succeed. 293 */ 294 ip6 = mtod(m, struct ip6_hdr *); 295 in6_clearscope(&ip6->ip6_src); 296 in6_clearscope(&ip6->ip6_dst); 297 298 bzero(&sendsrc, sizeof(sendsrc)); 299 sendsrc.send_len = sizeof(sendsrc); 300 sendsrc.send_family = AF_INET6; 301 sendsrc.send_direction = direction; 302 sendsrc.send_ifidx = ifp->if_index; 303 304 /* 305 * Send incoming or outgoing traffic to user space either to be 306 * protected (outgoing) or validated (incoming) according to rfc3971. 307 */ 308 SOCKBUF_LOCK(&V_send_so->so_rcv); 309 if (sbappendaddr_locked(&V_send_so->so_rcv, 310 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 311 soroverflow_locked(V_send_so); 312 /* XXX stats. */ 313 m_freem(m); 314 } else { 315 sorwakeup_locked(V_send_so); 316 } 317 318 SEND_UNLOCK(); 319 return (0); 320 } 321 322 static struct protosw send_protosw = { 323 .pr_type = SOCK_RAW, 324 .pr_flags = PR_ATOMIC|PR_ADDR, 325 .pr_protocol = IPPROTO_SEND, 326 .pr_attach = send_attach, 327 .pr_send = send_send, 328 .pr_detach = send_close 329 }; 330 331 static int 332 send_modevent(module_t mod, int type, void *unused) 333 { 334 #ifdef __notyet__ 335 VNET_ITERATOR_DECL(vnet_iter); 336 #endif 337 int error; 338 339 switch (type) { 340 case MOD_LOAD: 341 SEND_LOCK_INIT(); 342 343 error = protosw_register(&inet6domain, &send_protosw); 344 if (error != 0) { 345 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 346 __func__, __LINE__, error); 347 SEND_LOCK_DESTROY(); 348 break; 349 } 350 send_sendso_input_hook = send_input; 351 break; 352 case MOD_UNLOAD: 353 /* Do not allow unloading w/o locking. */ 354 return (EBUSY); 355 #ifdef __notyet__ 356 VNET_LIST_RLOCK_NOSLEEP(); 357 SEND_LOCK(); 358 VNET_FOREACH(vnet_iter) { 359 CURVNET_SET(vnet_iter); 360 if (V_send_so != NULL) { 361 CURVNET_RESTORE(); 362 SEND_UNLOCK(); 363 VNET_LIST_RUNLOCK_NOSLEEP(); 364 return (EBUSY); 365 } 366 CURVNET_RESTORE(); 367 } 368 SEND_UNLOCK(); 369 VNET_LIST_RUNLOCK_NOSLEEP(); 370 error = protosw_unregister(&send_protosw); 371 if (error == 0) 372 SEND_LOCK_DESTROY(); 373 send_sendso_input_hook = NULL; 374 break; 375 #endif 376 default: 377 error = 0; 378 break; 379 } 380 381 return (error); 382 } 383 384 static moduledata_t sendmod = { 385 "send", 386 send_modevent, 387 0 388 }; 389 390 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 391