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 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 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 234 if (ifp == NULL) { 235 error = ENETUNREACH; 236 goto err; 237 } 238 239 error = send_output(m, ifp, sendsrc->send_direction); 240 if_rele(ifp); 241 m = NULL; 242 243 err: 244 if (m != NULL) 245 m_freem(m); 246 return (error); 247 } 248 249 static void 250 send_close(struct socket *so) 251 { 252 253 SEND_LOCK(); 254 if (V_send_so) 255 V_send_so = NULL; 256 SEND_UNLOCK(); 257 } 258 259 /* 260 * Send a SeND message to user space, that was either received and has to be 261 * validated or was about to be send out and has to be handled by the SEND 262 * daemon adding SeND ICMPv6 options. 263 */ 264 static int 265 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 266 { 267 struct ip6_hdr *ip6; 268 struct sockaddr_send sendsrc; 269 270 SEND_LOCK(); 271 if (V_send_so == NULL) { 272 SEND_UNLOCK(); 273 return (-1); 274 } 275 276 /* 277 * Make sure to clear any possible internally embedded scope before 278 * passing the packet to user space for SeND cryptographic signature 279 * validation to succeed. 280 */ 281 ip6 = mtod(m, struct ip6_hdr *); 282 in6_clearscope(&ip6->ip6_src); 283 in6_clearscope(&ip6->ip6_dst); 284 285 bzero(&sendsrc, sizeof(sendsrc)); 286 sendsrc.send_len = sizeof(sendsrc); 287 sendsrc.send_family = AF_INET6; 288 sendsrc.send_direction = direction; 289 sendsrc.send_ifidx = ifp->if_index; 290 291 /* 292 * Send incoming or outgoing traffic to user space either to be 293 * protected (outgoing) or validated (incoming) according to rfc3971. 294 */ 295 SOCKBUF_LOCK(&V_send_so->so_rcv); 296 if (sbappendaddr_locked(&V_send_so->so_rcv, 297 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 298 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 299 /* XXX stats. */ 300 m_freem(m); 301 } else { 302 sorwakeup_locked(V_send_so); 303 } 304 305 SEND_UNLOCK(); 306 return (0); 307 } 308 309 struct pr_usrreqs send_usrreqs = { 310 .pru_attach = send_attach, 311 .pru_send = send_send, 312 .pru_detach = send_close 313 }; 314 struct protosw send_protosw = { 315 .pr_type = SOCK_RAW, 316 .pr_flags = PR_ATOMIC|PR_ADDR, 317 .pr_protocol = IPPROTO_SEND, 318 .pr_usrreqs = &send_usrreqs 319 }; 320 321 static int 322 send_modevent(module_t mod, int type, void *unused) 323 { 324 #ifdef __notyet__ 325 VNET_ITERATOR_DECL(vnet_iter); 326 #endif 327 int error; 328 329 switch (type) { 330 case MOD_LOAD: 331 SEND_LOCK_INIT(); 332 333 error = pf_proto_register(PF_INET6, &send_protosw); 334 if (error != 0) { 335 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 336 __func__, __LINE__, error); 337 SEND_LOCK_DESTROY(); 338 break; 339 } 340 send_sendso_input_hook = send_input; 341 break; 342 case MOD_UNLOAD: 343 /* Do not allow unloading w/o locking. */ 344 return (EBUSY); 345 #ifdef __notyet__ 346 VNET_LIST_RLOCK_NOSLEEP(); 347 SEND_LOCK(); 348 VNET_FOREACH(vnet_iter) { 349 CURVNET_SET(vnet_iter); 350 if (V_send_so != NULL) { 351 CURVNET_RESTORE(); 352 SEND_UNLOCK(); 353 VNET_LIST_RUNLOCK_NOSLEEP(); 354 return (EBUSY); 355 } 356 CURVNET_RESTORE(); 357 } 358 SEND_UNLOCK(); 359 VNET_LIST_RUNLOCK_NOSLEEP(); 360 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 361 if (error == 0) 362 SEND_LOCK_DESTROY(); 363 send_sendso_input_hook = NULL; 364 break; 365 #endif 366 default: 367 error = 0; 368 break; 369 } 370 371 return (error); 372 } 373 374 static moduledata_t sendmod = { 375 "send", 376 send_modevent, 377 0 378 }; 379 380 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 381