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 */ 39 40 #include <sys/types.h> 41 #include <sys/socket.h> 42 #include <sys/queue.h> 43 #include <net/if.h> 44 #include <netinet/in.h> 45 #include <ifaddrs.h> 46 #include <sys/poll.h> 47 #include <rpc/rpc.h> 48 #include <errno.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <netdb.h> 53 #include <netconfig.h> 54 #include <stdio.h> 55 #include <arpa/inet.h> 56 57 #include "rpcbind.h" 58 59 #define SA2SIN(sa) ((struct sockaddr_in *)(sa)) 60 #define SA2SINADDR(sa) (SA2SIN(sa)->sin_addr) 61 #ifdef INET6 62 #define SA2SIN6(sa) ((struct sockaddr_in6 *)(sa)) 63 #define SA2SIN6ADDR(sa) (SA2SIN6(sa)->sin6_addr) 64 #endif 65 66 static struct sockaddr_in *local_in4; 67 #ifdef INET6 68 static struct sockaddr_in6 *local_in6; 69 #endif 70 71 static int bitmaskcmp(void *, void *, void *, int); 72 #ifdef INET6 73 static void in6_fillscopeid(struct sockaddr_in6 *); 74 #endif 75 76 /* 77 * For all bits set in "mask", compare the corresponding bits in 78 * "dst" and "src", and see if they match. Returns 0 if the addresses 79 * match. 80 */ 81 static int 82 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 83 { 84 int i; 85 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 86 87 for (i = 0; i < bytelen; i++) 88 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i])) 89 return (1); 90 return (0); 91 } 92 93 /* 94 * Similar to code in ifconfig.c. Fill in the scope ID for link-local 95 * addresses returned by getifaddrs(). 96 */ 97 #ifdef INET6 98 static void 99 in6_fillscopeid(struct sockaddr_in6 *sin6) 100 { 101 u_int16_t ifindex; 102 103 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 104 ifindex = ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); 105 if (sin6->sin6_scope_id == 0 && ifindex != 0) { 106 sin6->sin6_scope_id = ifindex; 107 *(u_int16_t *)&sin6->sin6_addr.s6_addr[2] = 0; 108 } 109 } 110 } 111 #endif 112 113 /* 114 * Find a server address that can be used by `caller' to contact 115 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is 116 * non-NULL, it is used instead of `caller' as a hint suggesting 117 * the best address (e.g. the `r_addr' field of an rpc, which 118 * contains the rpcbind server address that the caller used). 119 * 120 * Returns the best server address as a malloc'd "universal address" 121 * string which should be freed by the caller. On error, returns NULL. 122 */ 123 char * 124 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 125 char *netid) 126 { 127 struct ifaddrs *ifap, *ifp = NULL, *bestif; 128 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf; 129 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa; 130 struct sockaddr_storage ss; 131 struct netconfig *nconf; 132 char *caller_uaddr = NULL, *hint_uaddr = NULL; 133 char *ret = NULL; 134 135 #ifdef ND_DEBUG 136 if (debugging) 137 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 138 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid); 139 #endif 140 caller_sa = caller->buf; 141 if ((nconf = rpcbind_get_conf(netid)) == NULL) 142 goto freeit; 143 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL) 144 goto freeit; 145 146 /* 147 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its 148 * address family is different from that of the caller. 149 */ 150 hint_sa = NULL; 151 if (clnt_uaddr != NULL) { 152 hint_uaddr = clnt_uaddr; 153 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL) 154 goto freeit; 155 hint_sa = hint_nbp->buf; 156 } 157 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) { 158 hint_uaddr = caller_uaddr; 159 hint_sa = caller->buf; 160 } 161 162 #ifdef ND_DEBUG 163 if (debugging) 164 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr); 165 #endif 166 /* Local caller, just return the server address. */ 167 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 || 168 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') { 169 ret = strdup(serv_uaddr); 170 goto freeit; 171 } 172 173 if (getifaddrs(&ifp) < 0) 174 goto freeit; 175 176 /* 177 * Loop through all interfaces. For each interface, see if the 178 * network portion of its address is equal to that of the client. 179 * If so, we have found the interface that we want to use. 180 */ 181 bestif = NULL; 182 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 183 ifsa = ifap->ifa_addr; 184 ifmasksa = ifap->ifa_netmask; 185 186 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family || 187 !(ifap->ifa_flags & IFF_UP)) 188 continue; 189 190 switch (hint_sa->sa_family) { 191 case AF_INET: 192 /* 193 * If the hint address matches this interface 194 * address/netmask, then we're done. 195 */ 196 if (!bitmaskcmp(&SA2SINADDR(ifsa), 197 &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa), 198 sizeof(struct in_addr))) { 199 bestif = ifap; 200 goto found; 201 } 202 break; 203 #ifdef INET6 204 case AF_INET6: 205 /* 206 * For v6 link local addresses, if the caller is on 207 * a link-local address then use the scope id to see 208 * which one. 209 */ 210 in6_fillscopeid(SA2SIN6(ifsa)); 211 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) && 212 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && 213 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) { 214 if (SA2SIN6(ifsa)->sin6_scope_id == 215 SA2SIN6(caller_sa)->sin6_scope_id) { 216 bestif = ifap; 217 goto found; 218 } 219 } else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa), 220 &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa), 221 sizeof(struct in6_addr))) { 222 bestif = ifap; 223 goto found; 224 } 225 break; 226 #endif 227 default: 228 continue; 229 } 230 231 /* 232 * Remember the first possibly useful interface, preferring 233 * "normal" to point-to-point and loopback ones. 234 */ 235 if (bestif == NULL || 236 (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) && 237 (bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)))) 238 bestif = ifap; 239 } 240 if (bestif == NULL) 241 goto freeit; 242 243 found: 244 /* 245 * Construct the new address using the the address from 246 * `bestif', and the port number from `serv_uaddr'. 247 */ 248 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 249 if (serv_nbp == NULL) 250 goto freeit; 251 serv_sa = serv_nbp->buf; 252 253 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len); 254 switch (ss.ss_family) { 255 case AF_INET: 256 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port; 257 break; 258 #ifdef INET6 259 case AF_INET6: 260 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port; 261 break; 262 #endif 263 } 264 tbuf.len = ss.ss_len; 265 tbuf.maxlen = sizeof(ss); 266 tbuf.buf = &ss; 267 ret = taddr2uaddr(nconf, &tbuf); 268 269 freeit: 270 if (caller_uaddr != NULL) 271 free(caller_uaddr); 272 if (hint_nbp != NULL) { 273 free(hint_nbp->buf); 274 free(hint_nbp); 275 } 276 if (serv_nbp != NULL) { 277 free(serv_nbp->buf); 278 free(serv_nbp); 279 } 280 if (ifp != NULL) 281 freeifaddrs(ifp); 282 283 #ifdef ND_DEBUG 284 if (debugging) 285 fprintf(stderr, "addrmerge: returning %s\n", ret); 286 #endif 287 return ret; 288 } 289 290 void 291 network_init(void) 292 { 293 #ifdef INET6 294 struct ifaddrs *ifap, *ifp; 295 struct ipv6_mreq mreq6; 296 unsigned int ifindex; 297 int s; 298 #endif 299 int ecode; 300 struct addrinfo hints, *res; 301 302 memset(&hints, 0, sizeof hints); 303 hints.ai_family = AF_INET; 304 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 305 if (debugging) 306 fprintf(stderr, "can't get local ip4 address: %s\n", 307 gai_strerror(ecode)); 308 } else { 309 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 310 if (local_in4 == NULL) { 311 if (debugging) 312 fprintf(stderr, "can't alloc local ip4 addr\n"); 313 } 314 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 315 } 316 317 #ifdef INET6 318 hints.ai_family = AF_INET6; 319 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 320 if (debugging) 321 fprintf(stderr, "can't get local ip6 address: %s\n", 322 gai_strerror(ecode)); 323 } else { 324 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 325 if (local_in6 == NULL) { 326 if (debugging) 327 fprintf(stderr, "can't alloc local ip6 addr\n"); 328 } 329 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 330 } 331 332 /* 333 * Now join the RPC ipv6 multicast group on all interfaces. 334 */ 335 if (getifaddrs(&ifp) < 0) 336 return; 337 338 mreq6.ipv6mr_interface = 0; 339 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 340 341 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 342 343 /* 344 * Loop through all interfaces. For each IPv6 multicast-capable 345 * interface, join the RPC multicast group on that interface. 346 */ 347 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 348 if (ifap->ifa_addr->sa_family != AF_INET6 || 349 !(ifap->ifa_flags & IFF_MULTICAST)) 350 continue; 351 ifindex = if_nametoindex(ifap->ifa_name); 352 if (ifindex == mreq6.ipv6mr_interface) 353 /* 354 * Already did this one. 355 */ 356 continue; 357 mreq6.ipv6mr_interface = ifindex; 358 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 359 sizeof mreq6) < 0) 360 if (debugging) 361 perror("setsockopt v6 multicast"); 362 } 363 #endif 364 365 /* close(s); */ 366 } 367 368 struct sockaddr * 369 local_sa(int af) 370 { 371 switch (af) { 372 case AF_INET: 373 return (struct sockaddr *)local_in4; 374 #ifdef INET6 375 case AF_INET6: 376 return (struct sockaddr *)local_in6; 377 #endif 378 default: 379 return NULL; 380 } 381 } 382