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/systm.h> 37 #include <sys/socket.h> 38 #include <sys/sockstate.h> 39 #include <sys/sockbuf.h> 40 #include <sys/socketvar.h> 41 #include <sys/types.h> 42 43 #include <net/route.h> 44 #include <net/if.h> 45 #include <net/if_var.h> 46 #include <net/vnet.h> 47 48 #include <netinet/in.h> 49 #include <netinet/ip_var.h> 50 #include <netinet/ip6.h> 51 #include <netinet/icmp6.h> 52 53 #include <netinet6/in6_var.h> 54 #include <netinet6/nd6.h> 55 #include <netinet6/scope6_var.h> 56 #include <netinet6/send.h> 57 58 static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery"); 59 60 /* 61 * The socket used to communicate with the SeND daemon. 62 */ 63 static VNET_DEFINE(struct socket *, send_so); 64 #define V_send_so VNET(send_so) 65 66 u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send)); 67 u_long send_recvspace = 9216; 68 69 struct mtx send_mtx; 70 #define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF) 71 #define SEND_LOCK() mtx_lock(&send_mtx) 72 #define SEND_UNLOCK() mtx_unlock(&send_mtx) 73 #define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx) 74 75 static int 76 send_attach(struct socket *so, int proto, struct thread *td) 77 { 78 int error; 79 80 SEND_LOCK(); 81 if (V_send_so != NULL) { 82 SEND_UNLOCK(); 83 return (EEXIST); 84 } 85 86 error = priv_check(td, PRIV_NETINET_RAW); 87 if (error) { 88 SEND_UNLOCK(); 89 return(error); 90 } 91 92 if (proto != IPPROTO_SEND) { 93 SEND_UNLOCK(); 94 return (EPROTONOSUPPORT); 95 } 96 error = soreserve(so, send_sendspace, send_recvspace); 97 if (error) { 98 SEND_UNLOCK(); 99 return(error); 100 } 101 102 V_send_so = so; 103 SEND_UNLOCK(); 104 105 return (0); 106 } 107 108 static int 109 send_output(struct mbuf *m, struct ifnet *ifp, int direction) 110 { 111 struct ip6_hdr *ip6; 112 struct sockaddr_in6 dst; 113 struct icmp6_hdr *icmp6; 114 int icmp6len; 115 116 /* 117 * Receive incoming (SeND-protected) or outgoing traffic 118 * (SeND-validated) from the SeND user space application. 119 */ 120 121 switch (direction) { 122 case SND_IN: 123 if (m->m_len < (sizeof(struct ip6_hdr) + 124 sizeof(struct icmp6_hdr))) { 125 m = m_pullup(m, sizeof(struct ip6_hdr) + 126 sizeof(struct icmp6_hdr)); 127 if (!m) 128 return (ENOBUFS); 129 } 130 131 /* Before passing off the mbuf record the proper interface. */ 132 m->m_pkthdr.rcvif = ifp; 133 134 if (m->m_flags & M_PKTHDR) 135 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 136 else 137 panic("Doh! not the first mbuf."); 138 139 ip6 = mtod(m, struct ip6_hdr *); 140 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 141 142 /* 143 * Output the packet as icmp6.c:icpm6_input() would do. 144 * The mbuf is always consumed, so we do not have to 145 * care about that. 146 */ 147 switch (icmp6->icmp6_type) { 148 case ND_NEIGHBOR_SOLICIT: 149 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 150 break; 151 case ND_NEIGHBOR_ADVERT: 152 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 153 break; 154 case ND_REDIRECT: 155 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 156 break; 157 case ND_ROUTER_SOLICIT: 158 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 159 break; 160 case ND_ROUTER_ADVERT: 161 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 162 break; 163 default: 164 return (ENOSYS); 165 } 166 return (0); 167 168 case SND_OUT: 169 if (m->m_len < sizeof(struct ip6_hdr)) { 170 m = m_pullup(m, sizeof(struct ip6_hdr)); 171 if (!m) 172 return (ENOBUFS); 173 } 174 ip6 = mtod(m, struct ip6_hdr *); 175 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 176 m->m_flags |= M_MCAST; 177 178 bzero(&dst, sizeof(dst)); 179 dst.sin6_family = AF_INET6; 180 dst.sin6_len = sizeof(dst); 181 dst.sin6_addr = ip6->ip6_dst; 182 183 /* 184 * Output the packet as nd6.c:nd6_output_lle() would do. 185 * The mbuf is always consumed, so we do not have to care 186 * about that. 187 * XXX-BZ as we added data, what about fragmenting, 188 * if now needed? 189 */ 190 int error; 191 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 192 NULL)); 193 if (error) 194 error = ENOENT; 195 return (error); 196 197 default: 198 panic("%s: direction %d neither SND_IN nor SND_OUT.", 199 __func__, direction); 200 } 201 } 202 203 /* 204 * Receive a SeND message from user space to be either send out by the kernel 205 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 206 * input path. 207 */ 208 static int 209 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 210 struct mbuf *control, struct thread *td) 211 { 212 struct sockaddr_send *sendsrc; 213 struct ifnet *ifp; 214 int error; 215 216 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 217 __func__, so, V_send_so)); 218 219 sendsrc = (struct sockaddr_send *)nam; 220 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 221 if (ifp == NULL) { 222 error = ENETUNREACH; 223 goto err; 224 } 225 226 error = send_output(m, ifp, sendsrc->send_direction); 227 if_rele(ifp); 228 m = NULL; 229 230 err: 231 if (m != NULL) 232 m_freem(m); 233 return (error); 234 } 235 236 static void 237 send_close(struct socket *so) 238 { 239 240 SEND_LOCK(); 241 if (V_send_so) 242 V_send_so = NULL; 243 SEND_UNLOCK(); 244 } 245 246 /* 247 * Send a SeND message to user space, that was either received and has to be 248 * validated or was about to be send out and has to be handled by the SEND 249 * daemon adding SeND ICMPv6 options. 250 */ 251 static int 252 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 253 { 254 struct ip6_hdr *ip6; 255 struct sockaddr_send sendsrc; 256 257 SEND_LOCK(); 258 if (V_send_so == NULL) { 259 SEND_UNLOCK(); 260 return (-1); 261 } 262 263 /* 264 * Make sure to clear any possible internally embedded scope before 265 * passing the packet to user space for SeND cryptographic signature 266 * validation to succeed. 267 */ 268 ip6 = mtod(m, struct ip6_hdr *); 269 in6_clearscope(&ip6->ip6_src); 270 in6_clearscope(&ip6->ip6_dst); 271 272 bzero(&sendsrc, sizeof(sendsrc)); 273 sendsrc.send_len = sizeof(sendsrc); 274 sendsrc.send_family = AF_INET6; 275 sendsrc.send_direction = direction; 276 sendsrc.send_ifidx = ifp->if_index; 277 278 /* 279 * Send incoming or outgoing traffic to user space either to be 280 * protected (outgoing) or validated (incoming) according to rfc3971. 281 */ 282 SOCKBUF_LOCK(&V_send_so->so_rcv); 283 if (sbappendaddr_locked(&V_send_so->so_rcv, 284 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 285 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 286 /* XXX stats. */ 287 m_freem(m); 288 } else { 289 sorwakeup_locked(V_send_so); 290 } 291 292 SEND_UNLOCK(); 293 return (0); 294 } 295 296 struct pr_usrreqs send_usrreqs = { 297 .pru_attach = send_attach, 298 .pru_send = send_send, 299 .pru_detach = send_close 300 }; 301 struct protosw send_protosw = { 302 .pr_type = SOCK_RAW, 303 .pr_flags = PR_ATOMIC|PR_ADDR, 304 .pr_protocol = IPPROTO_SEND, 305 .pr_usrreqs = &send_usrreqs 306 }; 307 308 static int 309 send_modevent(module_t mod, int type, void *unused) 310 { 311 #ifdef __notyet__ 312 VNET_ITERATOR_DECL(vnet_iter); 313 #endif 314 int error; 315 316 switch (type) { 317 case MOD_LOAD: 318 SEND_LOCK_INIT(); 319 320 error = pf_proto_register(PF_INET6, &send_protosw); 321 if (error != 0) { 322 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 323 __func__, __LINE__, error); 324 SEND_LOCK_DESTROY(); 325 break; 326 } 327 send_sendso_input_hook = send_input; 328 break; 329 case MOD_UNLOAD: 330 /* Do not allow unloading w/o locking. */ 331 return (EBUSY); 332 #ifdef __notyet__ 333 VNET_LIST_RLOCK_NOSLEEP(); 334 SEND_LOCK(); 335 VNET_FOREACH(vnet_iter) { 336 CURVNET_SET(vnet_iter); 337 if (V_send_so != NULL) { 338 CURVNET_RESTORE(); 339 SEND_UNLOCK(); 340 VNET_LIST_RUNLOCK_NOSLEEP(); 341 return (EBUSY); 342 } 343 CURVNET_RESTORE(); 344 } 345 SEND_UNLOCK(); 346 VNET_LIST_RUNLOCK_NOSLEEP(); 347 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 348 if (error == 0) 349 SEND_LOCK_DESTROY(); 350 send_sendso_input_hook = NULL; 351 break; 352 #endif 353 default: 354 error = 0; 355 break; 356 } 357 358 return (error); 359 } 360 361 static moduledata_t sendmod = { 362 "send", 363 send_modevent, 364 0 365 }; 366 367 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 368