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 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 235 if (ifp == NULL) { 236 error = ENETUNREACH; 237 goto err; 238 } 239 240 error = send_output(m, ifp, sendsrc->send_direction); 241 if_rele(ifp); 242 m = NULL; 243 244 err: 245 if (m != NULL) 246 m_freem(m); 247 return (error); 248 } 249 250 static void 251 send_close(struct socket *so) 252 { 253 254 SEND_LOCK(); 255 if (V_send_so) 256 V_send_so = NULL; 257 SEND_UNLOCK(); 258 } 259 260 /* 261 * Send a SeND message to user space, that was either received and has to be 262 * validated or was about to be send out and has to be handled by the SEND 263 * daemon adding SeND ICMPv6 options. 264 */ 265 static int 266 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 267 { 268 struct ip6_hdr *ip6; 269 struct sockaddr_send sendsrc; 270 271 SEND_LOCK(); 272 if (V_send_so == NULL) { 273 SEND_UNLOCK(); 274 return (-1); 275 } 276 277 /* 278 * Make sure to clear any possible internally embedded scope before 279 * passing the packet to user space for SeND cryptographic signature 280 * validation to succeed. 281 */ 282 ip6 = mtod(m, struct ip6_hdr *); 283 in6_clearscope(&ip6->ip6_src); 284 in6_clearscope(&ip6->ip6_dst); 285 286 bzero(&sendsrc, sizeof(sendsrc)); 287 sendsrc.send_len = sizeof(sendsrc); 288 sendsrc.send_family = AF_INET6; 289 sendsrc.send_direction = direction; 290 sendsrc.send_ifidx = ifp->if_index; 291 292 /* 293 * Send incoming or outgoing traffic to user space either to be 294 * protected (outgoing) or validated (incoming) according to rfc3971. 295 */ 296 SOCKBUF_LOCK(&V_send_so->so_rcv); 297 if (sbappendaddr_locked(&V_send_so->so_rcv, 298 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 299 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 300 /* XXX stats. */ 301 m_freem(m); 302 } else { 303 sorwakeup_locked(V_send_so); 304 } 305 306 SEND_UNLOCK(); 307 return (0); 308 } 309 310 struct pr_usrreqs send_usrreqs = { 311 .pru_attach = send_attach, 312 .pru_send = send_send, 313 .pru_detach = send_close 314 }; 315 struct protosw send_protosw = { 316 .pr_type = SOCK_RAW, 317 .pr_flags = PR_ATOMIC|PR_ADDR, 318 .pr_protocol = IPPROTO_SEND, 319 .pr_usrreqs = &send_usrreqs 320 }; 321 322 static int 323 send_modevent(module_t mod, int type, void *unused) 324 { 325 #ifdef __notyet__ 326 VNET_ITERATOR_DECL(vnet_iter); 327 #endif 328 int error; 329 330 switch (type) { 331 case MOD_LOAD: 332 SEND_LOCK_INIT(); 333 334 error = pf_proto_register(PF_INET6, &send_protosw); 335 if (error != 0) { 336 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 337 __func__, __LINE__, error); 338 SEND_LOCK_DESTROY(); 339 break; 340 } 341 send_sendso_input_hook = send_input; 342 break; 343 case MOD_UNLOAD: 344 /* Do not allow unloading w/o locking. */ 345 return (EBUSY); 346 #ifdef __notyet__ 347 VNET_LIST_RLOCK_NOSLEEP(); 348 SEND_LOCK(); 349 VNET_FOREACH(vnet_iter) { 350 CURVNET_SET(vnet_iter); 351 if (V_send_so != NULL) { 352 CURVNET_RESTORE(); 353 SEND_UNLOCK(); 354 VNET_LIST_RUNLOCK_NOSLEEP(); 355 return (EBUSY); 356 } 357 CURVNET_RESTORE(); 358 } 359 SEND_UNLOCK(); 360 VNET_LIST_RUNLOCK_NOSLEEP(); 361 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 362 if (error == 0) 363 SEND_LOCK_DESTROY(); 364 send_sendso_input_hook = NULL; 365 break; 366 #endif 367 default: 368 error = 0; 369 break; 370 } 371 372 return (error); 373 } 374 375 static moduledata_t sendmod = { 376 "send", 377 send_modevent, 378 0 379 }; 380 381 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 382