1 /*- 2 * Copyright (c) 2009-2010 Ana Kukec <anchie@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 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/sockstate.h> 41 #include <sys/sockbuf.h> 42 #include <sys/socketvar.h> 43 #include <sys/types.h> 44 45 #include <net/route.h> 46 #include <net/if.h> 47 #include <net/if_var.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 static VNET_DEFINE(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 int icmp6len; 118 119 /* 120 * Receive incoming (SeND-protected) or outgoing traffic 121 * (SeND-validated) from the SeND user space application. 122 */ 123 124 switch (direction) { 125 case SND_IN: 126 if (m->m_len < (sizeof(struct ip6_hdr) + 127 sizeof(struct icmp6_hdr))) { 128 m = m_pullup(m, sizeof(struct ip6_hdr) + 129 sizeof(struct icmp6_hdr)); 130 if (!m) 131 return (ENOBUFS); 132 } 133 134 /* Before passing off the mbuf record the proper interface. */ 135 m->m_pkthdr.rcvif = ifp; 136 137 if (m->m_flags & M_PKTHDR) 138 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 139 else 140 panic("Doh! not the first mbuf."); 141 142 ip6 = mtod(m, struct ip6_hdr *); 143 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 144 145 /* 146 * Output the packet as icmp6.c:icpm6_input() would do. 147 * The mbuf is always consumed, so we do not have to 148 * care about that. 149 */ 150 switch (icmp6->icmp6_type) { 151 case ND_NEIGHBOR_SOLICIT: 152 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 153 break; 154 case ND_NEIGHBOR_ADVERT: 155 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 156 break; 157 case ND_REDIRECT: 158 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 159 break; 160 case ND_ROUTER_SOLICIT: 161 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 162 break; 163 case ND_ROUTER_ADVERT: 164 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 165 break; 166 default: 167 m_freem(m); 168 return (ENOSYS); 169 } 170 return (0); 171 172 case SND_OUT: 173 if (m->m_len < sizeof(struct ip6_hdr)) { 174 m = m_pullup(m, sizeof(struct ip6_hdr)); 175 if (!m) 176 return (ENOBUFS); 177 } 178 ip6 = mtod(m, struct ip6_hdr *); 179 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 180 m->m_flags |= M_MCAST; 181 182 bzero(&dst, sizeof(dst)); 183 dst.sin6_family = AF_INET6; 184 dst.sin6_len = sizeof(dst); 185 dst.sin6_addr = ip6->ip6_dst; 186 187 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 188 189 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 190 191 /* 192 * Output the packet as nd6.c:nd6_output_lle() would do. 193 * The mbuf is always consumed, so we do not have to care 194 * about that. 195 * XXX-BZ as we added data, what about fragmenting, 196 * if now needed? 197 */ 198 int error; 199 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 200 NULL)); 201 if (error) 202 error = ENOENT; 203 return (error); 204 205 default: 206 panic("%s: direction %d neither SND_IN nor SND_OUT.", 207 __func__, direction); 208 } 209 } 210 211 /* 212 * Receive a SeND message from user space to be either send out by the kernel 213 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 214 * input path. 215 */ 216 static int 217 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 218 struct mbuf *control, struct thread *td) 219 { 220 struct sockaddr_send *sendsrc; 221 struct ifnet *ifp; 222 int error; 223 224 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 225 __func__, so, V_send_so)); 226 227 sendsrc = (struct sockaddr_send *)nam; 228 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 229 if (ifp == NULL) { 230 error = ENETUNREACH; 231 goto err; 232 } 233 234 error = send_output(m, ifp, sendsrc->send_direction); 235 if_rele(ifp); 236 m = NULL; 237 238 err: 239 if (m != NULL) 240 m_freem(m); 241 return (error); 242 } 243 244 static void 245 send_close(struct socket *so) 246 { 247 248 SEND_LOCK(); 249 if (V_send_so) 250 V_send_so = NULL; 251 SEND_UNLOCK(); 252 } 253 254 /* 255 * Send a SeND message to user space, that was either received and has to be 256 * validated or was about to be send out and has to be handled by the SEND 257 * daemon adding SeND ICMPv6 options. 258 */ 259 static int 260 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 261 { 262 struct ip6_hdr *ip6; 263 struct sockaddr_send sendsrc; 264 265 SEND_LOCK(); 266 if (V_send_so == NULL) { 267 SEND_UNLOCK(); 268 return (-1); 269 } 270 271 /* 272 * Make sure to clear any possible internally embedded scope before 273 * passing the packet to user space for SeND cryptographic signature 274 * validation to succeed. 275 */ 276 ip6 = mtod(m, struct ip6_hdr *); 277 in6_clearscope(&ip6->ip6_src); 278 in6_clearscope(&ip6->ip6_dst); 279 280 bzero(&sendsrc, sizeof(sendsrc)); 281 sendsrc.send_len = sizeof(sendsrc); 282 sendsrc.send_family = AF_INET6; 283 sendsrc.send_direction = direction; 284 sendsrc.send_ifidx = ifp->if_index; 285 286 /* 287 * Send incoming or outgoing traffic to user space either to be 288 * protected (outgoing) or validated (incoming) according to rfc3971. 289 */ 290 SOCKBUF_LOCK(&V_send_so->so_rcv); 291 if (sbappendaddr_locked(&V_send_so->so_rcv, 292 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 293 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 294 /* XXX stats. */ 295 m_freem(m); 296 } else { 297 sorwakeup_locked(V_send_so); 298 } 299 300 SEND_UNLOCK(); 301 return (0); 302 } 303 304 struct pr_usrreqs send_usrreqs = { 305 .pru_attach = send_attach, 306 .pru_send = send_send, 307 .pru_detach = send_close 308 }; 309 struct protosw send_protosw = { 310 .pr_type = SOCK_RAW, 311 .pr_flags = PR_ATOMIC|PR_ADDR, 312 .pr_protocol = IPPROTO_SEND, 313 .pr_usrreqs = &send_usrreqs 314 }; 315 316 static int 317 send_modevent(module_t mod, int type, void *unused) 318 { 319 #ifdef __notyet__ 320 VNET_ITERATOR_DECL(vnet_iter); 321 #endif 322 int error; 323 324 switch (type) { 325 case MOD_LOAD: 326 SEND_LOCK_INIT(); 327 328 error = pf_proto_register(PF_INET6, &send_protosw); 329 if (error != 0) { 330 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 331 __func__, __LINE__, error); 332 SEND_LOCK_DESTROY(); 333 break; 334 } 335 send_sendso_input_hook = send_input; 336 break; 337 case MOD_UNLOAD: 338 /* Do not allow unloading w/o locking. */ 339 return (EBUSY); 340 #ifdef __notyet__ 341 VNET_LIST_RLOCK_NOSLEEP(); 342 SEND_LOCK(); 343 VNET_FOREACH(vnet_iter) { 344 CURVNET_SET(vnet_iter); 345 if (V_send_so != NULL) { 346 CURVNET_RESTORE(); 347 SEND_UNLOCK(); 348 VNET_LIST_RUNLOCK_NOSLEEP(); 349 return (EBUSY); 350 } 351 CURVNET_RESTORE(); 352 } 353 SEND_UNLOCK(); 354 VNET_LIST_RUNLOCK_NOSLEEP(); 355 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 356 if (error == 0) 357 SEND_LOCK_DESTROY(); 358 send_sendso_input_hook = NULL; 359 break; 360 #endif 361 default: 362 error = 0; 363 break; 364 } 365 366 return (error); 367 } 368 369 static moduledata_t sendmod = { 370 "send", 371 send_modevent, 372 0 373 }; 374 375 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 376