1 /*- 2 * Copyright (c) 2000 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Frank van der Linden. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the NetBSD 19 * Foundation, Inc. and its contributors. 20 * 4. Neither the name of The NetBSD Foundation nor the names of its 21 * contributors may be used to endorse or promote products derived 22 * from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 * 36 * $NetBSD: util.c,v 1.4 2000/08/03 00:04:30 fvdl Exp $ 37 * $FreeBSD: src/usr.sbin/rpcbind/util.c,v 1.6 2007/11/07 10:53:39 kevlo Exp $ 38 * $DragonFly$ 39 */ 40 41 #include <sys/types.h> 42 #include <sys/socket.h> 43 #include <sys/queue.h> 44 #include <net/if.h> 45 #include <netinet/in.h> 46 #include <ifaddrs.h> 47 #include <sys/poll.h> 48 #include <rpc/rpc.h> 49 #include <errno.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <netdb.h> 54 #include <netconfig.h> 55 #include <stdio.h> 56 #include <arpa/inet.h> 57 58 #include "rpcbind.h" 59 60 #define SA2SIN(sa) ((struct sockaddr_in *)(sa)) 61 #define SA2SINADDR(sa) (SA2SIN(sa)->sin_addr) 62 #ifdef INET6 63 #define SA2SIN6(sa) ((struct sockaddr_in6 *)(sa)) 64 #define SA2SIN6ADDR(sa) (SA2SIN6(sa)->sin6_addr) 65 #endif 66 67 static struct sockaddr_in *local_in4; 68 #ifdef INET6 69 static struct sockaddr_in6 *local_in6; 70 #endif 71 72 static int bitmaskcmp(void *, void *, void *, int); 73 #ifdef INET6 74 static void in6_fillscopeid(struct sockaddr_in6 *); 75 #endif 76 77 /* 78 * For all bits set in "mask", compare the corresponding bits in 79 * "dst" and "src", and see if they match. Returns 0 if the addresses 80 * match. 81 */ 82 static int 83 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 84 { 85 int i; 86 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 87 88 for (i = 0; i < bytelen; i++) 89 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i])) 90 return (1); 91 return (0); 92 } 93 94 /* 95 * Similar to code in ifconfig.c. Fill in the scope ID for link-local 96 * addresses returned by getifaddrs(). 97 */ 98 #ifdef INET6 99 static void 100 in6_fillscopeid(struct sockaddr_in6 *sin6) 101 { 102 u_int16_t ifindex; 103 104 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 105 ifindex = ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); 106 if (sin6->sin6_scope_id == 0 && ifindex != 0) { 107 sin6->sin6_scope_id = ifindex; 108 *(u_int16_t *)&sin6->sin6_addr.s6_addr[2] = 0; 109 } 110 } 111 } 112 #endif 113 114 /* 115 * Find a server address that can be used by `caller' to contact 116 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is 117 * non-NULL, it is used instead of `caller' as a hint suggesting 118 * the best address (e.g. the `r_addr' field of an rpc, which 119 * contains the rpcbind server address that the caller used). 120 * 121 * Returns the best server address as a malloc'd "universal address" 122 * string which should be freed by the caller. On error, returns NULL. 123 */ 124 char * 125 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 126 char *netid) 127 { 128 struct ifaddrs *ifap, *ifp = NULL, *bestif; 129 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf; 130 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa; 131 struct sockaddr_storage ss; 132 struct netconfig *nconf; 133 char *caller_uaddr = NULL, *hint_uaddr = NULL; 134 char *ret = NULL; 135 136 #ifdef ND_DEBUG 137 if (debugging) 138 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 139 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid); 140 #endif 141 caller_sa = caller->buf; 142 if ((nconf = rpcbind_get_conf(netid)) == NULL) 143 goto freeit; 144 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL) 145 goto freeit; 146 147 /* 148 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its 149 * address family is different from that of the caller. 150 */ 151 hint_sa = NULL; 152 if (clnt_uaddr != NULL) { 153 hint_uaddr = clnt_uaddr; 154 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL) 155 goto freeit; 156 hint_sa = hint_nbp->buf; 157 } 158 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) { 159 hint_uaddr = caller_uaddr; 160 hint_sa = caller->buf; 161 } 162 163 #ifdef ND_DEBUG 164 if (debugging) 165 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr); 166 #endif 167 /* Local caller, just return the server address. */ 168 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 || 169 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') { 170 ret = strdup(serv_uaddr); 171 goto freeit; 172 } 173 174 if (getifaddrs(&ifp) < 0) 175 goto freeit; 176 177 /* 178 * Loop through all interfaces. For each interface, see if the 179 * network portion of its address is equal to that of the client. 180 * If so, we have found the interface that we want to use. 181 */ 182 bestif = NULL; 183 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 184 ifsa = ifap->ifa_addr; 185 ifmasksa = ifap->ifa_netmask; 186 187 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family || 188 !(ifap->ifa_flags & IFF_UP)) 189 continue; 190 191 switch (hint_sa->sa_family) { 192 case AF_INET: 193 /* 194 * If the hint address matches this interface 195 * address/netmask, then we're done. 196 */ 197 if (!bitmaskcmp(&SA2SINADDR(ifsa), 198 &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa), 199 sizeof(struct in_addr))) { 200 bestif = ifap; 201 goto found; 202 } 203 break; 204 #ifdef INET6 205 case AF_INET6: 206 /* 207 * For v6 link local addresses, if the caller is on 208 * a link-local address then use the scope id to see 209 * which one. 210 */ 211 in6_fillscopeid(SA2SIN6(ifsa)); 212 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) && 213 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && 214 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) { 215 if (SA2SIN6(ifsa)->sin6_scope_id == 216 SA2SIN6(caller_sa)->sin6_scope_id) { 217 bestif = ifap; 218 goto found; 219 } 220 } else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa), 221 &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa), 222 sizeof(struct in6_addr))) { 223 bestif = ifap; 224 goto found; 225 } 226 break; 227 #endif 228 default: 229 continue; 230 } 231 232 /* 233 * Remember the first possibly useful interface, preferring 234 * "normal" to point-to-point and loopback ones. 235 */ 236 if (bestif == NULL || 237 (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) && 238 (bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)))) 239 bestif = ifap; 240 } 241 if (bestif == NULL) 242 goto freeit; 243 244 found: 245 /* 246 * Construct the new address using the the address from 247 * `bestif', and the port number from `serv_uaddr'. 248 */ 249 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 250 if (serv_nbp == NULL) 251 goto freeit; 252 serv_sa = serv_nbp->buf; 253 254 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len); 255 switch (ss.ss_family) { 256 case AF_INET: 257 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port; 258 break; 259 #ifdef INET6 260 case AF_INET6: 261 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port; 262 break; 263 #endif 264 } 265 tbuf.len = ss.ss_len; 266 tbuf.maxlen = sizeof(ss); 267 tbuf.buf = &ss; 268 ret = taddr2uaddr(nconf, &tbuf); 269 270 freeit: 271 if (caller_uaddr != NULL) 272 free(caller_uaddr); 273 if (hint_nbp != NULL) { 274 free(hint_nbp->buf); 275 free(hint_nbp); 276 } 277 if (serv_nbp != NULL) { 278 free(serv_nbp->buf); 279 free(serv_nbp); 280 } 281 if (ifp != NULL) 282 freeifaddrs(ifp); 283 284 #ifdef ND_DEBUG 285 if (debugging) 286 fprintf(stderr, "addrmerge: returning %s\n", ret); 287 #endif 288 return ret; 289 } 290 291 void 292 network_init(void) 293 { 294 #ifdef INET6 295 struct ifaddrs *ifap, *ifp; 296 struct ipv6_mreq mreq6; 297 unsigned int ifindex; 298 int s; 299 #endif 300 int ecode; 301 struct addrinfo hints, *res; 302 303 memset(&hints, 0, sizeof hints); 304 hints.ai_family = AF_INET; 305 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 306 if (debugging) 307 fprintf(stderr, "can't get local ip4 address: %s\n", 308 gai_strerror(ecode)); 309 } else { 310 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 311 if (local_in4 == NULL) { 312 if (debugging) 313 fprintf(stderr, "can't alloc local ip4 addr\n"); 314 } 315 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 316 } 317 318 #ifdef INET6 319 hints.ai_family = AF_INET6; 320 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 321 if (debugging) 322 fprintf(stderr, "can't get local ip6 address: %s\n", 323 gai_strerror(ecode)); 324 } else { 325 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 326 if (local_in6 == NULL) { 327 if (debugging) 328 fprintf(stderr, "can't alloc local ip6 addr\n"); 329 } 330 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 331 } 332 333 /* 334 * Now join the RPC ipv6 multicast group on all interfaces. 335 */ 336 if (getifaddrs(&ifp) < 0) 337 return; 338 339 mreq6.ipv6mr_interface = 0; 340 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 341 342 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 343 344 /* 345 * Loop through all interfaces. For each IPv6 multicast-capable 346 * interface, join the RPC multicast group on that interface. 347 */ 348 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 349 if (ifap->ifa_addr->sa_family != AF_INET6 || 350 !(ifap->ifa_flags & IFF_MULTICAST)) 351 continue; 352 ifindex = if_nametoindex(ifap->ifa_name); 353 if (ifindex == mreq6.ipv6mr_interface) 354 /* 355 * Already did this one. 356 */ 357 continue; 358 mreq6.ipv6mr_interface = ifindex; 359 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 360 sizeof mreq6) < 0) 361 if (debugging) 362 perror("setsockopt v6 multicast"); 363 } 364 #endif 365 366 /* close(s); */ 367 } 368 369 struct sockaddr * 370 local_sa(int af) 371 { 372 switch (af) { 373 case AF_INET: 374 return (struct sockaddr *)local_in4; 375 #ifdef INET6 376 case AF_INET6: 377 return (struct sockaddr *)local_in6; 378 #endif 379 default: 380 return NULL; 381 } 382 } 383