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/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 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 158 break; 159 case ND_NEIGHBOR_ADVERT: 160 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 161 break; 162 case ND_REDIRECT: 163 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 164 break; 165 case ND_ROUTER_SOLICIT: 166 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 167 break; 168 case ND_ROUTER_ADVERT: 169 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 170 break; 171 default: 172 m_freem(m); 173 error = ENOSYS; 174 } 175 NET_EPOCH_EXIT(et); 176 177 return (error); 178 179 case SND_OUT: 180 if (m->m_len < sizeof(struct ip6_hdr)) { 181 m = m_pullup(m, sizeof(struct ip6_hdr)); 182 if (!m) 183 return (ENOBUFS); 184 } 185 ip6 = mtod(m, struct ip6_hdr *); 186 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 187 m->m_flags |= M_MCAST; 188 189 bzero(&dst, sizeof(dst)); 190 dst.sin6_family = AF_INET6; 191 dst.sin6_len = sizeof(dst); 192 dst.sin6_addr = ip6->ip6_dst; 193 194 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 195 196 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 197 198 /* 199 * Output the packet as nd6.c:nd6_output_lle() would do. 200 * The mbuf is always consumed, so we do not have to care 201 * about that. 202 * XXX-BZ as we added data, what about fragmenting, 203 * if now needed? 204 */ 205 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 206 NULL)); 207 if (error) 208 error = ENOENT; 209 return (error); 210 211 default: 212 panic("%s: direction %d neither SND_IN nor SND_OUT.", 213 __func__, direction); 214 } 215 } 216 217 /* 218 * Receive a SeND message from user space to be either send out by the kernel 219 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 220 * input path. 221 */ 222 static int 223 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 224 struct mbuf *control, struct thread *td) 225 { 226 struct sockaddr_send *sendsrc; 227 struct ifnet *ifp; 228 int error; 229 230 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 231 __func__, so, V_send_so)); 232 233 sendsrc = (struct sockaddr_send *)nam; 234 if (sendsrc->send_family != AF_INET6) { 235 error = EAFNOSUPPORT; 236 goto err; 237 } 238 if (sendsrc->send_len != sizeof(*sendsrc)) { 239 error = EINVAL; 240 goto err; 241 } 242 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 243 if (ifp == NULL) { 244 error = ENETUNREACH; 245 goto err; 246 } 247 248 error = send_output(m, ifp, sendsrc->send_direction); 249 if_rele(ifp); 250 m = NULL; 251 252 err: 253 if (control != NULL) 254 m_freem(control); 255 if (m != NULL) 256 m_freem(m); 257 258 return (error); 259 } 260 261 static void 262 send_close(struct socket *so) 263 { 264 265 SEND_LOCK(); 266 if (V_send_so) 267 V_send_so = NULL; 268 SEND_UNLOCK(); 269 } 270 271 /* 272 * Send a SeND message to user space, that was either received and has to be 273 * validated or was about to be send out and has to be handled by the SEND 274 * daemon adding SeND ICMPv6 options. 275 */ 276 static int 277 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 278 { 279 struct ip6_hdr *ip6; 280 struct sockaddr_send sendsrc; 281 282 SEND_LOCK(); 283 if (V_send_so == NULL) { 284 SEND_UNLOCK(); 285 return (-1); 286 } 287 288 /* 289 * Make sure to clear any possible internally embedded scope before 290 * passing the packet to user space for SeND cryptographic signature 291 * validation to succeed. 292 */ 293 ip6 = mtod(m, struct ip6_hdr *); 294 in6_clearscope(&ip6->ip6_src); 295 in6_clearscope(&ip6->ip6_dst); 296 297 bzero(&sendsrc, sizeof(sendsrc)); 298 sendsrc.send_len = sizeof(sendsrc); 299 sendsrc.send_family = AF_INET6; 300 sendsrc.send_direction = direction; 301 sendsrc.send_ifidx = ifp->if_index; 302 303 /* 304 * Send incoming or outgoing traffic to user space either to be 305 * protected (outgoing) or validated (incoming) according to rfc3971. 306 */ 307 SOCKBUF_LOCK(&V_send_so->so_rcv); 308 if (sbappendaddr_locked(&V_send_so->so_rcv, 309 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 310 soroverflow_locked(V_send_so); 311 /* XXX stats. */ 312 m_freem(m); 313 } else { 314 sorwakeup_locked(V_send_so); 315 } 316 317 SEND_UNLOCK(); 318 return (0); 319 } 320 321 struct pr_usrreqs send_usrreqs = { 322 .pru_attach = send_attach, 323 .pru_send = send_send, 324 .pru_detach = send_close 325 }; 326 struct protosw send_protosw = { 327 .pr_type = SOCK_RAW, 328 .pr_flags = PR_ATOMIC|PR_ADDR, 329 .pr_protocol = IPPROTO_SEND, 330 .pr_usrreqs = &send_usrreqs 331 }; 332 333 static int 334 send_modevent(module_t mod, int type, void *unused) 335 { 336 #ifdef __notyet__ 337 VNET_ITERATOR_DECL(vnet_iter); 338 #endif 339 int error; 340 341 switch (type) { 342 case MOD_LOAD: 343 SEND_LOCK_INIT(); 344 345 error = pf_proto_register(PF_INET6, &send_protosw); 346 if (error != 0) { 347 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 348 __func__, __LINE__, error); 349 SEND_LOCK_DESTROY(); 350 break; 351 } 352 send_sendso_input_hook = send_input; 353 break; 354 case MOD_UNLOAD: 355 /* Do not allow unloading w/o locking. */ 356 return (EBUSY); 357 #ifdef __notyet__ 358 VNET_LIST_RLOCK_NOSLEEP(); 359 SEND_LOCK(); 360 VNET_FOREACH(vnet_iter) { 361 CURVNET_SET(vnet_iter); 362 if (V_send_so != NULL) { 363 CURVNET_RESTORE(); 364 SEND_UNLOCK(); 365 VNET_LIST_RUNLOCK_NOSLEEP(); 366 return (EBUSY); 367 } 368 CURVNET_RESTORE(); 369 } 370 SEND_UNLOCK(); 371 VNET_LIST_RUNLOCK_NOSLEEP(); 372 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 373 if (error == 0) 374 SEND_LOCK_DESTROY(); 375 send_sendso_input_hook = NULL; 376 break; 377 #endif 378 default: 379 error = 0; 380 break; 381 } 382 383 return (error); 384 } 385 386 static moduledata_t sendmod = { 387 "send", 388 send_modevent, 389 0 390 }; 391 392 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 393