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