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 int icmp6len; 119 120 /* 121 * Receive incoming (SeND-protected) or outgoing traffic 122 * (SeND-validated) from the SeND user space application. 123 */ 124 125 switch (direction) { 126 case SND_IN: 127 if (m->m_len < (sizeof(struct ip6_hdr) + 128 sizeof(struct icmp6_hdr))) { 129 m = m_pullup(m, sizeof(struct ip6_hdr) + 130 sizeof(struct icmp6_hdr)); 131 if (!m) 132 return (ENOBUFS); 133 } 134 135 /* Before passing off the mbuf record the proper interface. */ 136 m->m_pkthdr.rcvif = ifp; 137 138 if (m->m_flags & M_PKTHDR) 139 icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr); 140 else 141 panic("Doh! not the first mbuf."); 142 143 ip6 = mtod(m, struct ip6_hdr *); 144 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 145 146 /* 147 * Output the packet as icmp6.c:icpm6_input() would do. 148 * The mbuf is always consumed, so we do not have to 149 * care about that. 150 */ 151 switch (icmp6->icmp6_type) { 152 case ND_NEIGHBOR_SOLICIT: 153 nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len); 154 break; 155 case ND_NEIGHBOR_ADVERT: 156 nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len); 157 break; 158 case ND_REDIRECT: 159 icmp6_redirect_input(m, sizeof(struct ip6_hdr)); 160 break; 161 case ND_ROUTER_SOLICIT: 162 nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len); 163 break; 164 case ND_ROUTER_ADVERT: 165 nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len); 166 break; 167 default: 168 m_freem(m); 169 return (ENOSYS); 170 } 171 return (0); 172 173 case SND_OUT: 174 if (m->m_len < sizeof(struct ip6_hdr)) { 175 m = m_pullup(m, sizeof(struct ip6_hdr)); 176 if (!m) 177 return (ENOBUFS); 178 } 179 ip6 = mtod(m, struct ip6_hdr *); 180 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 181 m->m_flags |= M_MCAST; 182 183 bzero(&dst, sizeof(dst)); 184 dst.sin6_family = AF_INET6; 185 dst.sin6_len = sizeof(dst); 186 dst.sin6_addr = ip6->ip6_dst; 187 188 m_clrprotoflags(m); /* Avoid confusing lower layers. */ 189 190 IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6); 191 192 /* 193 * Output the packet as nd6.c:nd6_output_lle() would do. 194 * The mbuf is always consumed, so we do not have to care 195 * about that. 196 * XXX-BZ as we added data, what about fragmenting, 197 * if now needed? 198 */ 199 int error; 200 error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst, 201 NULL)); 202 if (error) 203 error = ENOENT; 204 return (error); 205 206 default: 207 panic("%s: direction %d neither SND_IN nor SND_OUT.", 208 __func__, direction); 209 } 210 } 211 212 /* 213 * Receive a SeND message from user space to be either send out by the kernel 214 * or, with SeND ICMPv6 options removed, to be further processed by the icmp6 215 * input path. 216 */ 217 static int 218 send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 219 struct mbuf *control, struct thread *td) 220 { 221 struct sockaddr_send *sendsrc; 222 struct ifnet *ifp; 223 int error; 224 225 KASSERT(V_send_so == so, ("%s: socket %p not send socket %p", 226 __func__, so, V_send_so)); 227 228 sendsrc = (struct sockaddr_send *)nam; 229 ifp = ifnet_byindex_ref(sendsrc->send_ifidx); 230 if (ifp == NULL) { 231 error = ENETUNREACH; 232 goto err; 233 } 234 235 error = send_output(m, ifp, sendsrc->send_direction); 236 if_rele(ifp); 237 m = NULL; 238 239 err: 240 if (m != NULL) 241 m_freem(m); 242 return (error); 243 } 244 245 static void 246 send_close(struct socket *so) 247 { 248 249 SEND_LOCK(); 250 if (V_send_so) 251 V_send_so = NULL; 252 SEND_UNLOCK(); 253 } 254 255 /* 256 * Send a SeND message to user space, that was either received and has to be 257 * validated or was about to be send out and has to be handled by the SEND 258 * daemon adding SeND ICMPv6 options. 259 */ 260 static int 261 send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused) 262 { 263 struct ip6_hdr *ip6; 264 struct sockaddr_send sendsrc; 265 266 SEND_LOCK(); 267 if (V_send_so == NULL) { 268 SEND_UNLOCK(); 269 return (-1); 270 } 271 272 /* 273 * Make sure to clear any possible internally embedded scope before 274 * passing the packet to user space for SeND cryptographic signature 275 * validation to succeed. 276 */ 277 ip6 = mtod(m, struct ip6_hdr *); 278 in6_clearscope(&ip6->ip6_src); 279 in6_clearscope(&ip6->ip6_dst); 280 281 bzero(&sendsrc, sizeof(sendsrc)); 282 sendsrc.send_len = sizeof(sendsrc); 283 sendsrc.send_family = AF_INET6; 284 sendsrc.send_direction = direction; 285 sendsrc.send_ifidx = ifp->if_index; 286 287 /* 288 * Send incoming or outgoing traffic to user space either to be 289 * protected (outgoing) or validated (incoming) according to rfc3971. 290 */ 291 SOCKBUF_LOCK(&V_send_so->so_rcv); 292 if (sbappendaddr_locked(&V_send_so->so_rcv, 293 (struct sockaddr *)&sendsrc, m, NULL) == 0) { 294 SOCKBUF_UNLOCK(&V_send_so->so_rcv); 295 /* XXX stats. */ 296 m_freem(m); 297 } else { 298 sorwakeup_locked(V_send_so); 299 } 300 301 SEND_UNLOCK(); 302 return (0); 303 } 304 305 struct pr_usrreqs send_usrreqs = { 306 .pru_attach = send_attach, 307 .pru_send = send_send, 308 .pru_detach = send_close 309 }; 310 struct protosw send_protosw = { 311 .pr_type = SOCK_RAW, 312 .pr_flags = PR_ATOMIC|PR_ADDR, 313 .pr_protocol = IPPROTO_SEND, 314 .pr_usrreqs = &send_usrreqs 315 }; 316 317 static int 318 send_modevent(module_t mod, int type, void *unused) 319 { 320 #ifdef __notyet__ 321 VNET_ITERATOR_DECL(vnet_iter); 322 #endif 323 int error; 324 325 switch (type) { 326 case MOD_LOAD: 327 SEND_LOCK_INIT(); 328 329 error = pf_proto_register(PF_INET6, &send_protosw); 330 if (error != 0) { 331 printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n", 332 __func__, __LINE__, error); 333 SEND_LOCK_DESTROY(); 334 break; 335 } 336 send_sendso_input_hook = send_input; 337 break; 338 case MOD_UNLOAD: 339 /* Do not allow unloading w/o locking. */ 340 return (EBUSY); 341 #ifdef __notyet__ 342 VNET_LIST_RLOCK_NOSLEEP(); 343 SEND_LOCK(); 344 VNET_FOREACH(vnet_iter) { 345 CURVNET_SET(vnet_iter); 346 if (V_send_so != NULL) { 347 CURVNET_RESTORE(); 348 SEND_UNLOCK(); 349 VNET_LIST_RUNLOCK_NOSLEEP(); 350 return (EBUSY); 351 } 352 CURVNET_RESTORE(); 353 } 354 SEND_UNLOCK(); 355 VNET_LIST_RUNLOCK_NOSLEEP(); 356 error = pf_proto_unregister(PF_INET6, IPPROTO_SEND, SOCK_RAW); 357 if (error == 0) 358 SEND_LOCK_DESTROY(); 359 send_sendso_input_hook = NULL; 360 break; 361 #endif 362 default: 363 error = 0; 364 break; 365 } 366 367 return (error); 368 } 369 370 static moduledata_t sendmod = { 371 "send", 372 send_modevent, 373 0 374 }; 375 376 DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 377