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/mbuf.h> 33 #include <sys/module.h> 34 #include <sys/priv.h> 35 #include <sys/protosw.h> 36 #include <sys/sdt.h> 37 #include <sys/systm.h> 38 #include <sys/socket.h> 39 #include <sys/sockstate.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/vnet.h> 48 49 #include <netinet/in.h> 50 #include <netinet/in_kdtrace.h> 51 #include <netinet/ip_var.h> 52 #include <netinet/ip6.h> 53 #include <netinet/icmp6.h> 54 55 #include <netinet6/in6_var.h> 56 #include <netinet6/nd6.h> 57 #include <netinet6/scope6_var.h> 58 #include <netinet6/send.h> 59 60 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery"); 61 62 /* 63 * The socket used to communicate with the SeND daemon. 64 */ 65 static VNET_DEFINE(struct socket *, send_so); 66 #define V_send_so VNET(send_so) 67 68 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send)); 69 u_long send_recvspace = 9216; 70 71 struct mtx send_mtx; 72 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF) 73 #define SEND_LOCK() mtx_lock(&send_mtx) 74 #define SEND_UNLOCK() mtx_unlock(&send_mtx) 75 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx) 76 77 static int 78 send_attach(struct socket *so, int proto, struct thread *td) 79 { 80 int error; 81 82 SEND_LOCK(); 83 if (V_send_so != NULL) { 84 SEND_UNLOCK(); 85 return (EEXIST); 86 } 87 88 error = priv_check(td, PRIV_NETINET_RAW); 89 if (error) { 90 SEND_UNLOCK(); 91 return(error); 92 } 93 94 if (proto != IPPROTO_SEND) { 95 SEND_UNLOCK(); 96 return (EPROTONOSUPPORT); 97 } 98 error = soreserve(so, send_sendspace, send_recvspace); 99 if (error) { 100 SEND_UNLOCK(); 101 return(error); 102 } 103 104 V_send_so = so; 105 SEND_UNLOCK(); 106 107 return (0); 108 } 109 110 static int 111 send_output(struct mbuf *m, struct ifnet *ifp, int direction) 112 { 113 struct ip6_hdr *ip6; 114 struct sockaddr_in6 dst; 115 struct icmp6_hdr *icmp6; 116 int icmp6len; 117 118 /* 119 * Receive incoming (SeND-protected) or outgoing traffic 120 * (SeND-validated) from the SeND user space application. 121 */ 122 123 switch (direction) { 124 case SND_IN: 125 if (m->m_len < (sizeof(struct ip6_hdr) + 126 sizeof(struct icmp6_hdr))) { 127 m = m_pullup(m, sizeof(struct ip6_hdr) + 128 sizeof(struct icmp6_hdr)); 129 if (!m) 130 return (ENOBUFS); 131 } 132 133 /* Before passing off the mbuf record the proper interface. */ 134 m->m_pkthdr.rcvif = ifp; 135 136 if (m->m_flags & M_PKTHDR) 137 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 138 else 139 panic("Doh! not the first mbuf."); 140 141 ip6 = mtod(m, struct ip6_hdr *); 142 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 143 144 /* 145 * Output the packet as icmp6.c:icpm6_input() would do. 146 * The mbuf is always consumed, so we do not have to 147 * care about that. 148 */ 149 switch (icmp6->icmp6_type) { 150 case ND_NEIGHBOR_SOLICIT: 151 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 152 break; 153 case ND_NEIGHBOR_ADVERT: 154 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 155 break; 156 case ND_REDIRECT: 157 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 158 break; 159 case ND_ROUTER_SOLICIT: 160 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 161 break; 162 case ND_ROUTER_ADVERT: 163 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 164 break; 165 default: 166 m_freem(m); 167 return (ENOSYS); 168 } 169 return (0); 170 171 case SND_OUT: 172 if (m->m_len < sizeof(struct ip6_hdr)) { 173 m = m_pullup(m, sizeof(struct ip6_hdr)); 174 if (!m) 175 return (ENOBUFS); 176 } 177 ip6 = mtod(m, struct ip6_hdr *); 178 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 179 m->m_flags |= M_MCAST; 180 181 bzero(&dst, sizeof(dst)); 182 dst.sin6_family = AF_INET6; 183 dst.sin6_len = sizeof(dst); 184 dst.sin6_addr = ip6->ip6_dst; 185 186 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 187 188 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 189 190 /* 191 * Output the packet as nd6.c:nd6_output_lle() would do. 192 * The mbuf is always consumed, so we do not have to care 193 * about that. 194 * XXX-BZ as we added data, what about fragmenting, 195 * if now needed? 196 */ 197 int error; 198 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 199 NULL)); 200 if (error) 201 error = ENOENT; 202 return (error); 203 204 default: 205 panic("%s: direction %d neither SND_IN nor SND_OUT.", 206 __func__, direction); 207 } 208 } 209 210 /* 211 * Receive a SeND message from user space to be either send out by the kernel 212 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 213 * input path. 214 */ 215 static int 216 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 217 struct mbuf *control, struct thread *td) 218 { 219 struct sockaddr_send *sendsrc; 220 struct ifnet *ifp; 221 int error; 222 223 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 224 __func__, so, V_send_so)); 225 226 sendsrc = (struct sockaddr_send *)nam; 227 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 228 if (ifp == NULL) { 229 error = ENETUNREACH; 230 goto err; 231 } 232 233 error = send_output(m, ifp, sendsrc->send_direction); 234 if_rele(ifp); 235 m = NULL; 236 237 err: 238 if (m != NULL) 239 m_freem(m); 240 return (error); 241 } 242 243 static void 244 send_close(struct socket *so) 245 { 246 247 SEND_LOCK(); 248 if (V_send_so) 249 V_send_so = NULL; 250 SEND_UNLOCK(); 251 } 252 253 /* 254 * Send a SeND message to user space, that was either received and has to be 255 * validated or was about to be send out and has to be handled by the SEND 256 * daemon adding SeND ICMPv6 options. 257 */ 258 static int 259 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 260 { 261 struct ip6_hdr *ip6; 262 struct sockaddr_send sendsrc; 263 264 SEND_LOCK(); 265 if (V_send_so == NULL) { 266 SEND_UNLOCK(); 267 return (-1); 268 } 269 270 /* 271 * Make sure to clear any possible internally embedded scope before 272 * passing the packet to user space for SeND cryptographic signature 273 * validation to succeed. 274 */ 275 ip6 = mtod(m, struct ip6_hdr *); 276 in6_clearscope(&ip6->ip6_src); 277 in6_clearscope(&ip6->ip6_dst); 278 279 bzero(&sendsrc, sizeof(sendsrc)); 280 sendsrc.send_len = sizeof(sendsrc); 281 sendsrc.send_family = AF_INET6; 282 sendsrc.send_direction = direction; 283 sendsrc.send_ifidx = ifp->if_index; 284 285 /* 286 * Send incoming or outgoing traffic to user space either to be 287 * protected (outgoing) or validated (incoming) according to rfc3971. 288 */ 289 SOCKBUF_LOCK(&V_send_so->so_rcv); 290 if (sbappendaddr_locked(&V_send_so->so_rcv, 291 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 292 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 293 /* XXX stats. */ 294 m_freem(m); 295 } else { 296 sorwakeup_locked(V_send_so); 297 } 298 299 SEND_UNLOCK(); 300 return (0); 301 } 302 303 struct pr_usrreqs send_usrreqs = { 304 .pru_attach = send_attach, 305 .pru_send = send_send, 306 .pru_detach = send_close 307 }; 308 struct protosw send_protosw = { 309 .pr_type = SOCK_RAW, 310 .pr_flags = PR_ATOMIC|PR_ADDR, 311 .pr_protocol = IPPROTO_SEND, 312 .pr_usrreqs = &send_usrreqs 313 }; 314 315 static int 316 send_modevent(module_t mod, int type, void *unused) 317 { 318 #ifdef __notyet__ 319 VNET_ITERATOR_DECL(vnet_iter); 320 #endif 321 int error; 322 323 switch (type) { 324 case MOD_LOAD: 325 SEND_LOCK_INIT(); 326 327 error = pf_proto_register(PF_INET6, &send_protosw); 328 if (error != 0) { 329 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 330 __func__, __LINE__, error); 331 SEND_LOCK_DESTROY(); 332 break; 333 } 334 send_sendso_input_hook = send_input; 335 break; 336 case MOD_UNLOAD: 337 /* Do not allow unloading w/o locking. */ 338 return (EBUSY); 339 #ifdef __notyet__ 340 VNET_LIST_RLOCK_NOSLEEP(); 341 SEND_LOCK(); 342 VNET_FOREACH(vnet_iter) { 343 CURVNET_SET(vnet_iter); 344 if (V_send_so != NULL) { 345 CURVNET_RESTORE(); 346 SEND_UNLOCK(); 347 VNET_LIST_RUNLOCK_NOSLEEP(); 348 return (EBUSY); 349 } 350 CURVNET_RESTORE(); 351 } 352 SEND_UNLOCK(); 353 VNET_LIST_RUNLOCK_NOSLEEP(); 354 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 355 if (error == 0) 356 SEND_LOCK_DESTROY(); 357 send_sendso_input_hook = NULL; 358 break; 359 #endif 360 default: 361 error = 0; 362 break; 363 } 364 365 return (error); 366 } 367 368 static moduledata_t sendmod = { 369 "send", 370 send_modevent, 371 0 372 }; 373 374 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 375