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