1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2009-2010 Ana Kukec <[email protected]> 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/vnet.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_kdtrace.h> 53 #include <netinet/ip_var.h> 54 #include <netinet/ip6.h> 55 #include <netinet/icmp6.h> 56 57 #include <netinet6/in6_var.h> 58 #include <netinet6/nd6.h> 59 #include <netinet6/scope6_var.h> 60 #include <netinet6/send.h> 61 62 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery"); 63 64 /* 65 * The socket used to communicate with the SeND daemon. 66 */ 67 VNET_DEFINE_STATIC(struct socket *, send_so); 68 #define V_send_so VNET(send_so) 69 70 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send)); 71 u_long send_recvspace = 9216; 72 73 struct mtx send_mtx; 74 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF) 75 #define SEND_LOCK() mtx_lock(&send_mtx) 76 #define SEND_UNLOCK() mtx_unlock(&send_mtx) 77 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx) 78 79 static int 80 send_attach(struct socket *so, int proto, struct thread *td) 81 { 82 int error; 83 84 SEND_LOCK(); 85 if (V_send_so != NULL) { 86 SEND_UNLOCK(); 87 return (EEXIST); 88 } 89 90 error = priv_check(td, PRIV_NETINET_RAW); 91 if (error) { 92 SEND_UNLOCK(); 93 return(error); 94 } 95 96 if (proto != IPPROTO_SEND) { 97 SEND_UNLOCK(); 98 return (EPROTONOSUPPORT); 99 } 100 error = soreserve(so, send_sendspace, send_recvspace); 101 if (error) { 102 SEND_UNLOCK(); 103 return(error); 104 } 105 106 V_send_so = so; 107 SEND_UNLOCK(); 108 109 return (0); 110 } 111 112 static int 113 send_output(struct mbuf *m, struct ifnet *ifp, int direction) 114 { 115 struct ip6_hdr *ip6; 116 struct sockaddr_in6 dst; 117 struct icmp6_hdr *icmp6; 118 struct epoch_tracker et; 119 int icmp6len; 120 int error; 121 122 /* 123 * Receive incoming (SeND-protected) or outgoing traffic 124 * (SeND-validated) from the SeND user space application. 125 */ 126 127 switch (direction) { 128 case SND_IN: 129 if (m->m_len < (sizeof(struct ip6_hdr) + 130 sizeof(struct icmp6_hdr))) { 131 m = m_pullup(m, sizeof(struct ip6_hdr) + 132 sizeof(struct icmp6_hdr)); 133 if (!m) 134 return (ENOBUFS); 135 } 136 137 /* Before passing off the mbuf record the proper interface. */ 138 m->m_pkthdr.rcvif = ifp; 139 140 if (m->m_flags & M_PKTHDR) 141 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 142 else 143 panic("Doh! not the first mbuf."); 144 145 ip6 = mtod(m, struct ip6_hdr *); 146 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 147 error = 0; 148 149 /* 150 * Output the packet as icmp6.c:icpm6_input() would do. 151 * The mbuf is always consumed, so we do not have to 152 * care about that. 153 */ 154 NET_EPOCH_ENTER(et); 155 switch (icmp6->icmp6_type) { 156 case ND_NEIGHBOR_SOLICIT: 157 NET_EPOCH_ENTER(et); 158 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 159 NET_EPOCH_EXIT(et); 160 break; 161 case ND_NEIGHBOR_ADVERT: 162 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 163 break; 164 case ND_REDIRECT: 165 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 166 break; 167 case ND_ROUTER_SOLICIT: 168 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 169 break; 170 case ND_ROUTER_ADVERT: 171 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 172 break; 173 default: 174 m_freem(m); 175 error = ENOSYS; 176 } 177 NET_EPOCH_EXIT(et); 178 179 return (error); 180 181 case SND_OUT: 182 if (m->m_len < sizeof(struct ip6_hdr)) { 183 m = m_pullup(m, sizeof(struct ip6_hdr)); 184 if (!m) 185 return (ENOBUFS); 186 } 187 ip6 = mtod(m, struct ip6_hdr *); 188 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 189 m->m_flags |= M_MCAST; 190 191 bzero(&dst, sizeof(dst)); 192 dst.sin6_family = AF_INET6; 193 dst.sin6_len = sizeof(dst); 194 dst.sin6_addr = ip6->ip6_dst; 195 196 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 197 198 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 199 200 /* 201 * Output the packet as nd6.c:nd6_output_lle() would do. 202 * The mbuf is always consumed, so we do not have to care 203 * about that. 204 * XXX-BZ as we added data, what about fragmenting, 205 * if now needed? 206 */ 207 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 208 NULL)); 209 if (error) 210 error = ENOENT; 211 return (error); 212 213 default: 214 panic("%s: direction %d neither SND_IN nor SND_OUT.", 215 __func__, direction); 216 } 217 } 218 219 /* 220 * Receive a SeND message from user space to be either send out by the kernel 221 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 222 * input path. 223 */ 224 static int 225 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 226 struct mbuf *control, struct thread *td) 227 { 228 struct sockaddr_send *sendsrc; 229 struct ifnet *ifp; 230 int error; 231 232 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 233 __func__, so, V_send_so)); 234 235 sendsrc = (struct sockaddr_send *)nam; 236 if (sendsrc->send_family != AF_INET6) { 237 error = EAFNOSUPPORT; 238 goto err; 239 } 240 if (sendsrc->send_len != sizeof(*sendsrc)) { 241 error = EINVAL; 242 goto err; 243 } 244 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 245 if (ifp == NULL) { 246 error = ENETUNREACH; 247 goto err; 248 } 249 250 error = send_output(m, ifp, sendsrc->send_direction); 251 if_rele(ifp); 252 m = NULL; 253 254 err: 255 if (control != NULL) 256 m_freem(control); 257 if (m != NULL) 258 m_freem(m); 259 260 return (error); 261 } 262 263 static void 264 send_close(struct socket *so) 265 { 266 267 SEND_LOCK(); 268 if (V_send_so) 269 V_send_so = NULL; 270 SEND_UNLOCK(); 271 } 272 273 /* 274 * Send a SeND message to user space, that was either received and has to be 275 * validated or was about to be send out and has to be handled by the SEND 276 * daemon adding SeND ICMPv6 options. 277 */ 278 static int 279 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 280 { 281 struct ip6_hdr *ip6; 282 struct sockaddr_send sendsrc; 283 284 SEND_LOCK(); 285 if (V_send_so == NULL) { 286 SEND_UNLOCK(); 287 return (-1); 288 } 289 290 /* 291 * Make sure to clear any possible internally embedded scope before 292 * passing the packet to user space for SeND cryptographic signature 293 * validation to succeed. 294 */ 295 ip6 = mtod(m, struct ip6_hdr *); 296 in6_clearscope(&ip6->ip6_src); 297 in6_clearscope(&ip6->ip6_dst); 298 299 bzero(&sendsrc, sizeof(sendsrc)); 300 sendsrc.send_len = sizeof(sendsrc); 301 sendsrc.send_family = AF_INET6; 302 sendsrc.send_direction = direction; 303 sendsrc.send_ifidx = ifp->if_index; 304 305 /* 306 * Send incoming or outgoing traffic to user space either to be 307 * protected (outgoing) or validated (incoming) according to rfc3971. 308 */ 309 SOCKBUF_LOCK(&V_send_so->so_rcv); 310 if (sbappendaddr_locked(&V_send_so->so_rcv, 311 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 312 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 313 /* XXX stats. */ 314 m_freem(m); 315 } else { 316 sorwakeup_locked(V_send_so); 317 } 318 319 SEND_UNLOCK(); 320 return (0); 321 } 322 323 struct pr_usrreqs send_usrreqs = { 324 .pru_attach = send_attach, 325 .pru_send = send_send, 326 .pru_detach = send_close 327 }; 328 struct protosw send_protosw = { 329 .pr_type = SOCK_RAW, 330 .pr_flags = PR_ATOMIC|PR_ADDR, 331 .pr_protocol = IPPROTO_SEND, 332 .pr_usrreqs = &send_usrreqs 333 }; 334 335 static int 336 send_modevent(module_t mod, int type, void *unused) 337 { 338 #ifdef __notyet__ 339 VNET_ITERATOR_DECL(vnet_iter); 340 #endif 341 int error; 342 343 switch (type) { 344 case MOD_LOAD: 345 SEND_LOCK_INIT(); 346 347 error = pf_proto_register(PF_INET6, &send_protosw); 348 if (error != 0) { 349 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 350 __func__, __LINE__, error); 351 SEND_LOCK_DESTROY(); 352 break; 353 } 354 send_sendso_input_hook = send_input; 355 break; 356 case MOD_UNLOAD: 357 /* Do not allow unloading w/o locking. */ 358 return (EBUSY); 359 #ifdef __notyet__ 360 VNET_LIST_RLOCK_NOSLEEP(); 361 SEND_LOCK(); 362 VNET_FOREACH(vnet_iter) { 363 CURVNET_SET(vnet_iter); 364 if (V_send_so != NULL) { 365 CURVNET_RESTORE(); 366 SEND_UNLOCK(); 367 VNET_LIST_RUNLOCK_NOSLEEP(); 368 return (EBUSY); 369 } 370 CURVNET_RESTORE(); 371 } 372 SEND_UNLOCK(); 373 VNET_LIST_RUNLOCK_NOSLEEP(); 374 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 375 if (error == 0) 376 SEND_LOCK_DESTROY(); 377 send_sendso_input_hook = NULL; 378 break; 379 #endif 380 default: 381 error = 0; 382 break; 383 } 384 385 return (error); 386 } 387 388 static moduledata_t sendmod = { 389 "send", 390 send_modevent, 391 0 392 }; 393 394 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 395