1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 29 /* All Rights Reserved */ 30 31 /* 32 * University Copyright- Copyright (c) 1982, 1986, 1988 33 * The Regents of the University of California 34 * All Rights Reserved 35 * 36 * University Acknowledgment- Portions of this document are derived from 37 * software developed by the University of California, Berkeley, and its 38 * contributors. 39 */ 40 41 #pragma ident "%Z%%M% %I% %E% SMI" 42 43 #include "c_synonyms.h" 44 #include <sys/types.h> 45 #include <sys/sockio.h> 46 #include <sys/socket.h> 47 #include <netinet/in.h> 48 #include <stdio.h> 49 #include <arpa/nameser.h> 50 #include <resolv.h> 51 52 #include <netinet/in.h> 53 #include <net/if.h> 54 #include <netinet/if_ether.h> 55 #include <arpa/inet.h> 56 57 #define MAXIFS 256 58 59 /* 60 * Resolver state default settings 61 */ 62 63 struct state _res = { 64 RES_TIMEOUT, /* retransmition time interval */ 65 4, /* number of times to retransmit */ 66 RES_DEFAULT, /* options flags */ 67 1, /* number of name servers */ 68 }; 69 70 /* 71 * Set up default settings. If the configuration file exist, the values 72 * there will have precedence. Otherwise, the server address is set to 73 * INADDR_LOOPBACK and the default domain name comes from the gethostname(). 74 * BUT if the NIS/RPC domain name is set, that is used if all else fails. 75 * 76 * The configuration file should only be used if you want to redefine your 77 * domain or run without a server on your machine. 78 * 79 * Note the user can always override then domain name with the environment 80 * variable LOCALDOMAIN which has absolute priority. 81 * 82 * 83 * Return 0 if completes successfully, -1 on error 84 */ 85 int 86 res_init(void) 87 { 88 register FILE *fp; 89 register char *cp, **pp; 90 register int n; 91 char buf[BUFSIZ]; 92 #ifdef SYSV 93 extern char *strchr(); 94 #else 95 extern char *index(); 96 #endif 97 extern char *strcpy(), *strncpy(); 98 extern char *getenv(); 99 int nserv = 0; /* number of nameserver records read from file */ 100 int haveenv = 0; 101 int havesearch = 0; 102 103 _res.nsaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); /* INADDR_ANY */ 104 _res.nsaddr.sin_family = AF_INET; 105 _res.nsaddr.sin_port = htons(NAMESERVER_PORT); 106 _res.nscount = 1; 107 108 #ifdef SIOCGIFNUM 109 { int numifs, s, n, int_up; 110 struct ifconf ifc; 111 register struct ifreq *ifrp; 112 struct ifreq ifr; 113 unsigned bufsize; 114 unsigned int flags; 115 char *buf; 116 extern void *malloc(); 117 118 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 119 perror("socket"); 120 return (-1); 121 } 122 if (ioctl(s, SIOCGIFNUM, (char *)&numifs) < 0) { 123 numifs = MAXIFS; 124 } 125 bufsize = numifs * sizeof (struct ifreq); 126 buf = (char *)malloc(bufsize); 127 if (buf == NULL) { 128 perror("out of memory"); 129 close(s); 130 return (-1); 131 } 132 ifc.ifc_len = bufsize; 133 ifc.ifc_buf = buf; 134 if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) { 135 perror("ifconfig: SIOCGIFCONF"); 136 close(s); 137 free(buf); 138 return (-1); 139 } 140 141 int_up = 0; 142 ifrp = ifc.ifc_req; 143 for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; 144 n--, ifrp++) { 145 memset((void *) &ifr, 0, sizeof (ifr)); 146 strncpy(ifr.ifr_name, ifrp->ifr_name, 147 sizeof (ifr.ifr_name)); 148 if (ioctl(s, SIOCGIFFLAGS, (char *)&ifr) < 0) { 149 perror("SIOCGIFFLAGS"); 150 close(s); 151 free(buf); 152 return (-1); 153 } 154 flags = ifr.ifr_flags; 155 /* we are looking for a non-loopback interface */ 156 if ((flags & IFF_UP) && ((flags & IFF_LOOPBACK) == 0)) 157 int_up = 1; 158 } 159 close(s); 160 free(buf); 161 if (int_up == 0) /* all the non-LOOPBACK interfaces are DOWN */ 162 return (-1); 163 } 164 #endif /* SIOCGIFNUM */ 165 166 167 /* 168 * for the benefit of hidden NIS domains, we use the same procedure 169 * as sendmail: convert leading + to dot, then drop to first dot 170 */ 171 getdomainname(buf, BUFSIZ); 172 if (buf[0] == '+') 173 buf[0] = '.'; 174 #ifdef SYSV 175 cp = strchr(buf, (int)'.'); 176 #else 177 cp = index(buf, '.'); 178 #endif 179 if (cp == NULL) 180 strcpy(_res.defdname, buf); 181 else 182 strcpy(_res.defdname, cp+1); 183 184 /* Allow user to override the local domain definition */ 185 if ((cp = getenv("LOCALDOMAIN")) != NULL) { 186 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname)); 187 haveenv++; 188 } 189 190 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) { 191 /* read the config file */ 192 while (fgets(buf, sizeof (buf), fp) != NULL) { 193 /* read default domain name */ 194 if (!strncmp(buf, "domain", sizeof ("domain") - 1)) { 195 if (haveenv) /* skip if have from environ */ 196 continue; 197 cp = buf + sizeof ("domain") - 1; 198 while (*cp == ' ' || *cp == '\t') 199 cp++; 200 if ((*cp == '\0') || (*cp == '\n')) 201 continue; 202 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); 203 #ifdef SYSV 204 if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) 205 #else 206 if ((cp = index(_res.defdname, '\n')) != NULL) 207 #endif 208 *cp = '\0'; 209 havesearch = 0; 210 continue; 211 } 212 /* set search list */ 213 if (!strncmp(buf, "search", sizeof ("search") - 1)) { 214 if (haveenv) /* skip if have from environ */ 215 continue; 216 cp = buf + sizeof ("search") - 1; 217 while (*cp == ' ' || *cp == '\t') 218 cp++; 219 if ((*cp == '\0') || (*cp == '\n')) 220 continue; 221 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); 222 #ifdef SYSV 223 if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) 224 #else 225 if ((cp = index(_res.defdname, '\n')) != NULL) 226 #endif 227 *cp = '\0'; 228 /* 229 * Set search list to be blank-separated strings 230 * on rest of line. 231 */ 232 cp = _res.defdname; 233 pp = _res.dnsrch; 234 *pp++ = cp; 235 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) { 236 if (*cp == ' ' || *cp == '\t') { 237 *cp = 0; 238 n = 1; 239 } else if (n) { 240 *pp++ = cp; 241 n = 0; 242 } 243 } 244 /* null terminate last domain if there are excess */ 245 while (*cp != '\0' && *cp != ' ' && *cp != '\t') 246 cp++; 247 *cp = '\0'; 248 *pp++ = 0; 249 havesearch = 1; 250 continue; 251 } 252 /* read nameservers to query */ 253 if (!strncmp(buf, "nameserver", sizeof ("nameserver") - 1) && 254 (nserv < MAXNS)) { 255 cp = buf + sizeof ("nameserver") - 1; 256 while (*cp == ' ' || *cp == '\t') 257 cp++; 258 if ((*cp == '\0') || (*cp == '\n')) 259 continue; 260 if ((_res.nsaddr_list[nserv].sin_addr.s_addr = 261 inet_addr(cp)) == (unsigned) -1) { 262 _res.nsaddr_list[n].sin_addr.s_addr = INADDR_ANY; 263 continue; 264 } 265 _res.nsaddr_list[nserv].sin_family = AF_INET; 266 _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT); 267 nserv++; 268 continue; 269 } 270 } 271 if (nserv > 1) 272 _res.nscount = nserv; 273 (void) fclose(fp); 274 } 275 if (_res.defdname[0] == 0) { 276 if (gethostname(buf, sizeof (_res.defdname)) == 0 && 277 #ifdef SYSV 278 (cp = strchr(buf, (int)'.'))) 279 #else 280 (cp = index(buf, '.'))) 281 #endif 282 (void) strcpy(_res.defdname, cp + 1); 283 } 284 285 /* find components of local domain that might be searched */ 286 if (havesearch == 0) { 287 pp = _res.dnsrch; 288 *pp++ = _res.defdname; 289 for (cp = _res.defdname, n = 0; *cp; cp++) 290 if (*cp == '.') 291 n++; 292 cp = _res.defdname; 293 for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH; n--) { 294 #ifdef SYSV 295 cp = strchr(cp, (int)'.'); 296 #else 297 cp = index(cp, '.'); 298 #endif 299 *pp++ = ++cp; 300 } 301 *pp++ = 0; 302 } 303 _res.options |= RES_INIT; 304 return (0); 305 } 306