1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/malloc.h> 33 #include <sys/mbuf.h> 34 #include <sys/module.h> 35 #include <sys/priv.h> 36 #include <sys/protosw.h> 37 #include <sys/sdt.h> 38 #include <sys/systm.h> 39 #include <sys/socket.h> 40 #include <sys/sockbuf.h> 41 #include <sys/socketvar.h> 42 #include <sys/types.h> 43 44 #include <net/route.h> 45 #include <net/if.h> 46 #include <net/if_var.h> 47 #include <net/if_private.h> 48 #include <net/vnet.h> 49 50 #include <netinet/in.h> 51 #include <netinet/in_kdtrace.h> 52 #include <netinet/ip_var.h> 53 #include <netinet/ip6.h> 54 #include <netinet/icmp6.h> 55 56 #include <netinet6/in6_var.h> 57 #include <netinet6/nd6.h> 58 #include <netinet6/scope6_var.h> 59 #include <netinet6/send.h> 60 61 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery"); 62 63 /* 64 * The socket used to communicate with the SeND daemon. 65 */ 66 VNET_DEFINE_STATIC(struct socket *, send_so); 67 #define V_send_so VNET(send_so) 68 69 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send)); 70 u_long send_recvspace = 9216; 71 72 struct mtx send_mtx; 73 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF) 74 #define SEND_LOCK() mtx_lock(&send_mtx) 75 #define SEND_UNLOCK() mtx_unlock(&send_mtx) 76 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx) 77 78 static int 79 send_attach(struct socket *so, int proto, struct thread *td) 80 { 81 int error; 82 83 SEND_LOCK(); 84 if (V_send_so != NULL) { 85 SEND_UNLOCK(); 86 return (EEXIST); 87 } 88 89 error = priv_check(td, PRIV_NETINET_RAW); 90 if (error) { 91 SEND_UNLOCK(); 92 return(error); 93 } 94 95 if (proto != IPPROTO_SEND) { 96 SEND_UNLOCK(); 97 return (EPROTONOSUPPORT); 98 } 99 error = soreserve(so, send_sendspace, send_recvspace); 100 if (error) { 101 SEND_UNLOCK(); 102 return(error); 103 } 104 105 V_send_so = so; 106 SEND_UNLOCK(); 107 108 return (0); 109 } 110 111 static int 112 send_output(struct mbuf *m, struct ifnet *ifp, int direction) 113 { 114 struct ip6_hdr *ip6; 115 struct sockaddr_in6 dst; 116 struct icmp6_hdr *icmp6; 117 struct epoch_tracker et; 118 int icmp6len; 119 int error; 120 121 /* 122 * Receive incoming (SeND-protected) or outgoing traffic 123 * (SeND-validated) from the SeND user space application. 124 */ 125 126 switch (direction) { 127 case SND_IN: 128 if (m->m_len < (sizeof(struct ip6_hdr) + 129 sizeof(struct icmp6_hdr))) { 130 m = m_pullup(m, sizeof(struct ip6_hdr) + 131 sizeof(struct icmp6_hdr)); 132 if (!m) 133 return (ENOBUFS); 134 } 135 136 /* Before passing off the mbuf record the proper interface. */ 137 m->m_pkthdr.rcvif = ifp; 138 139 if (m->m_flags & M_PKTHDR) 140 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 141 else 142 panic("Doh! not the first mbuf."); 143 144 ip6 = mtod(m, struct ip6_hdr *); 145 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 146 error = 0; 147 148 /* 149 * Output the packet as icmp6.c:icpm6_input() would do. 150 * The mbuf is always consumed, so we do not have to 151 * care about that. 152 */ 153 NET_EPOCH_ENTER(et); 154 switch (icmp6->icmp6_type) { 155 case ND_NEIGHBOR_SOLICIT: 156 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 157 break; 158 case ND_NEIGHBOR_ADVERT: 159 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 160 break; 161 case ND_REDIRECT: 162 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 163 break; 164 case ND_ROUTER_SOLICIT: 165 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 166 break; 167 case ND_ROUTER_ADVERT: 168 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 169 break; 170 default: 171 m_freem(m); 172 error = ENOSYS; 173 } 174 NET_EPOCH_EXIT(et); 175 176 return (error); 177 178 case SND_OUT: 179 if (m->m_len < sizeof(struct ip6_hdr)) { 180 m = m_pullup(m, sizeof(struct ip6_hdr)); 181 if (!m) 182 return (ENOBUFS); 183 } 184 ip6 = mtod(m, struct ip6_hdr *); 185 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 186 m->m_flags |= M_MCAST; 187 188 bzero(&dst, sizeof(dst)); 189 dst.sin6_family = AF_INET6; 190 dst.sin6_len = sizeof(dst); 191 dst.sin6_addr = ip6->ip6_dst; 192 193 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 194 195 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 196 197 /* 198 * Output the packet as nd6.c:nd6_output_lle() would do. 199 * The mbuf is always consumed, so we do not have to care 200 * about that. 201 * XXX-BZ as we added data, what about fragmenting, 202 * if now needed? 203 */ 204 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 205 NULL)); 206 if (error) 207 error = ENOENT; 208 return (error); 209 210 default: 211 panic("%s: direction %d neither SND_IN nor SND_OUT.", 212 __func__, direction); 213 } 214 } 215 216 /* 217 * Receive a SeND message from user space to be either send out by the kernel 218 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 219 * input path. 220 */ 221 static int 222 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 223 struct mbuf *control, struct thread *td) 224 { 225 struct sockaddr_send *sendsrc; 226 struct ifnet *ifp; 227 int error; 228 229 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 230 __func__, so, V_send_so)); 231 232 sendsrc = (struct sockaddr_send *)nam; 233 if (sendsrc->send_family != AF_INET6) { 234 error = EAFNOSUPPORT; 235 goto err; 236 } 237 if (sendsrc->send_len != sizeof(*sendsrc)) { 238 error = EINVAL; 239 goto err; 240 } 241 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 242 if (ifp == NULL) { 243 error = ENETUNREACH; 244 goto err; 245 } 246 247 error = send_output(m, ifp, sendsrc->send_direction); 248 if_rele(ifp); 249 m = NULL; 250 251 err: 252 if (control != NULL) 253 m_freem(control); 254 if (m != NULL) 255 m_freem(m); 256 257 return (error); 258 } 259 260 static void 261 send_close(struct socket *so) 262 { 263 264 SEND_LOCK(); 265 if (V_send_so) 266 V_send_so = NULL; 267 SEND_UNLOCK(); 268 } 269 270 /* 271 * Send a SeND message to user space, that was either received and has to be 272 * validated or was about to be send out and has to be handled by the SEND 273 * daemon adding SeND ICMPv6 options. 274 */ 275 static int 276 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 277 { 278 struct ip6_hdr *ip6; 279 struct sockaddr_send sendsrc; 280 281 SEND_LOCK(); 282 if (V_send_so == NULL) { 283 SEND_UNLOCK(); 284 return (-1); 285 } 286 287 /* 288 * Make sure to clear any possible internally embedded scope before 289 * passing the packet to user space for SeND cryptographic signature 290 * validation to succeed. 291 */ 292 ip6 = mtod(m, struct ip6_hdr *); 293 in6_clearscope(&ip6->ip6_src); 294 in6_clearscope(&ip6->ip6_dst); 295 296 bzero(&sendsrc, sizeof(sendsrc)); 297 sendsrc.send_len = sizeof(sendsrc); 298 sendsrc.send_family = AF_INET6; 299 sendsrc.send_direction = direction; 300 sendsrc.send_ifidx = ifp->if_index; 301 302 /* 303 * Send incoming or outgoing traffic to user space either to be 304 * protected (outgoing) or validated (incoming) according to rfc3971. 305 */ 306 SOCKBUF_LOCK(&V_send_so->so_rcv); 307 if (sbappendaddr_locked(&V_send_so->so_rcv, 308 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 309 soroverflow_locked(V_send_so); 310 /* XXX stats. */ 311 m_freem(m); 312 } else { 313 sorwakeup_locked(V_send_so); 314 } 315 316 SEND_UNLOCK(); 317 return (0); 318 } 319 320 static struct protosw send_protosw = { 321 .pr_type = SOCK_RAW, 322 .pr_flags = PR_ATOMIC|PR_ADDR, 323 .pr_protocol = IPPROTO_SEND, 324 .pr_attach = send_attach, 325 .pr_send = send_send, 326 .pr_detach = send_close 327 }; 328 329 static int 330 send_modevent(module_t mod, int type, void *unused) 331 { 332 #ifdef __notyet__ 333 VNET_ITERATOR_DECL(vnet_iter); 334 #endif 335 int error; 336 337 switch (type) { 338 case MOD_LOAD: 339 SEND_LOCK_INIT(); 340 341 error = protosw_register(&inet6domain, &send_protosw); 342 if (error != 0) { 343 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 344 __func__, __LINE__, error); 345 SEND_LOCK_DESTROY(); 346 break; 347 } 348 send_sendso_input_hook = send_input; 349 break; 350 case MOD_UNLOAD: 351 /* Do not allow unloading w/o locking. */ 352 return (EBUSY); 353 #ifdef __notyet__ 354 VNET_LIST_RLOCK_NOSLEEP(); 355 SEND_LOCK(); 356 VNET_FOREACH(vnet_iter) { 357 CURVNET_SET(vnet_iter); 358 if (V_send_so != NULL) { 359 CURVNET_RESTORE(); 360 SEND_UNLOCK(); 361 VNET_LIST_RUNLOCK_NOSLEEP(); 362 return (EBUSY); 363 } 364 CURVNET_RESTORE(); 365 } 366 SEND_UNLOCK(); 367 VNET_LIST_RUNLOCK_NOSLEEP(); 368 error = protosw_unregister(&send_protosw); 369 if (error == 0) 370 SEND_LOCK_DESTROY(); 371 send_sendso_input_hook = NULL; 372 break; 373 #endif 374 default: 375 error = 0; 376 break; 377 } 378 379 return (error); 380 } 381 382 static moduledata_t sendmod = { 383 "send", 384 send_modevent, 385 0 386 }; 387 388 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 389