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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2015 Gary Mills 24 * Copyright 2008 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 #include <sys/types.h> 42 #include <sys/sockio.h> 43 #include <sys/socket.h> 44 #include <netinet/in.h> 45 #include <stdio.h> 46 #include <string.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 #include <stropts.h> 50 #include <arpa/nameser.h> 51 #include <resolv.h> 52 53 #include <netinet/in.h> 54 #include <net/if.h> 55 #include <netinet/if_ether.h> 56 #include <arpa/inet.h> 57 58 /* 59 * Undocumented external function in libnsl 60 */ 61 extern int 62 getdomainname(char *, int); 63 64 #define MAXIFS 256 65 66 /* 67 * Resolver state default settings 68 */ 69 70 struct state _res = { 71 RES_TIMEOUT, /* retransmition time interval */ 72 4, /* number of times to retransmit */ 73 RES_DEFAULT, /* options flags */ 74 1, /* number of name servers */ 75 }; 76 77 /* 78 * Set up default settings. If the configuration file exist, the values 79 * there will have precedence. Otherwise, the server address is set to 80 * INADDR_LOOPBACK and the default domain name comes from the gethostname(). 81 * BUT if the NIS/RPC domain name is set, that is used if all else fails. 82 * 83 * The configuration file should only be used if you want to redefine your 84 * domain or run without a server on your machine. 85 * 86 * Note the user can always override then domain name with the environment 87 * variable LOCALDOMAIN which has absolute priority. 88 * 89 * 90 * Return 0 if completes successfully, -1 on error 91 */ 92 int 93 res_init(void) 94 { 95 register FILE *fp; 96 register char *cp, **pp; 97 register int n; 98 char buf[BUFSIZ]; 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; 116 117 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 118 perror("socket"); 119 return (-1); 120 } 121 if (ioctl(s, SIOCGIFNUM, (char *)&numifs) < 0) { 122 numifs = MAXIFS; 123 } 124 bufsize = numifs * sizeof (struct ifreq); 125 buf = (char *)malloc(bufsize); 126 if (buf == NULL) { 127 perror("out of memory"); 128 (void) close(s); 129 return (-1); 130 } 131 ifc.ifc_len = bufsize; 132 ifc.ifc_buf = buf; 133 if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) { 134 perror("ifconfig: SIOCGIFCONF"); 135 (void) close(s); 136 free(buf); 137 return (-1); 138 } 139 140 int_up = 0; 141 ifrp = ifc.ifc_req; 142 for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; 143 n--, ifrp++) { 144 (void) memset((void *) &ifr, 0, sizeof (ifr)); 145 strncpy(ifr.ifr_name, ifrp->ifr_name, 146 sizeof (ifr.ifr_name)); 147 if (ioctl(s, SIOCGIFFLAGS, (char *)&ifr) < 0) { 148 perror("SIOCGIFFLAGS"); 149 (void) close(s); 150 free(buf); 151 return (-1); 152 } 153 flags = ifr.ifr_flags; 154 /* we are looking for a non-loopback interface */ 155 if ((flags & IFF_UP) && ((flags & IFF_LOOPBACK) == 0)) 156 int_up = 1; 157 } 158 (void) close(s); 159 free(buf); 160 if (int_up == 0) /* all the non-LOOPBACK interfaces are DOWN */ 161 return (-1); 162 } 163 #endif /* SIOCGIFNUM */ 164 165 166 /* 167 * for the benefit of hidden NIS domains, we use the same procedure 168 * as sendmail: convert leading + to dot, then drop to first dot 169 */ 170 (void) getdomainname(buf, BUFSIZ); 171 if (buf[0] == '+') 172 buf[0] = '.'; 173 #ifdef SYSV 174 cp = strchr(buf, (int)'.'); 175 #else 176 cp = index(buf, '.'); 177 #endif 178 if (cp == NULL) 179 strcpy(_res.defdname, buf); 180 else 181 strcpy(_res.defdname, cp+1); 182 183 /* Allow user to override the local domain definition */ 184 if ((cp = getenv("LOCALDOMAIN")) != NULL) { 185 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname)); 186 haveenv++; 187 } 188 189 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) { 190 /* read the config file */ 191 while (fgets(buf, sizeof (buf), fp) != NULL) { 192 /* read default domain name */ 193 if (!strncmp(buf, "domain", sizeof ("domain") - 1)) { 194 if (haveenv) /* skip if have from environ */ 195 continue; 196 cp = buf + sizeof ("domain") - 1; 197 while (*cp == ' ' || *cp == '\t') 198 cp++; 199 if ((*cp == '\0') || (*cp == '\n')) 200 continue; 201 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); 202 #ifdef SYSV 203 if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) 204 #else 205 if ((cp = index(_res.defdname, '\n')) != NULL) 206 #endif 207 *cp = '\0'; 208 havesearch = 0; 209 continue; 210 } 211 /* set search list */ 212 if (!strncmp(buf, "search", sizeof ("search") - 1)) { 213 if (haveenv) /* skip if have from environ */ 214 continue; 215 cp = buf + sizeof ("search") - 1; 216 while (*cp == ' ' || *cp == '\t') 217 cp++; 218 if ((*cp == '\0') || (*cp == '\n')) 219 continue; 220 (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); 221 #ifdef SYSV 222 if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) 223 #else 224 if ((cp = index(_res.defdname, '\n')) != NULL) 225 #endif 226 *cp = '\0'; 227 /* 228 * Set search list to be blank-separated strings 229 * on rest of line. 230 */ 231 cp = _res.defdname; 232 pp = _res.dnsrch; 233 *pp++ = cp; 234 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) { 235 if (*cp == ' ' || *cp == '\t') { 236 *cp = 0; 237 n = 1; 238 } else if (n) { 239 *pp++ = cp; 240 n = 0; 241 } 242 } 243 /* null terminate last domain if there are excess */ 244 while (*cp != '\0' && *cp != ' ' && *cp != '\t') 245 cp++; 246 *cp = '\0'; 247 *pp++ = 0; 248 havesearch = 1; 249 continue; 250 } 251 /* read nameservers to query */ 252 if (!strncmp(buf, "nameserver", sizeof ("nameserver") - 1) && 253 (nserv < MAXNS)) { 254 cp = buf + sizeof ("nameserver") - 1; 255 while (*cp == ' ' || *cp == '\t') 256 cp++; 257 if ((*cp == '\0') || (*cp == '\n')) 258 continue; 259 if ((_res.nsaddr_list[nserv].sin_addr.s_addr = 260 inet_addr(cp)) == (unsigned) -1) { 261 _res.nsaddr_list[n].sin_addr.s_addr = INADDR_ANY; 262 continue; 263 } 264 _res.nsaddr_list[nserv].sin_family = AF_INET; 265 _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT); 266 nserv++; 267 continue; 268 } 269 } 270 if (nserv > 1) 271 _res.nscount = nserv; 272 (void) fclose(fp); 273 } 274 if (_res.defdname[0] == 0) { 275 if (gethostname(buf, sizeof (_res.defdname)) == 0 && 276 #ifdef SYSV 277 (cp = strchr(buf, (int)'.'))) 278 #else 279 (cp = index(buf, '.'))) 280 #endif 281 (void) strcpy(_res.defdname, cp + 1); 282 } 283 284 /* find components of local domain that might be searched */ 285 if (havesearch == 0) { 286 pp = _res.dnsrch; 287 *pp++ = _res.defdname; 288 for (cp = _res.defdname, n = 0; *cp; cp++) 289 if (*cp == '.') 290 n++; 291 cp = _res.defdname; 292 for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH; n--) { 293 #ifdef SYSV 294 cp = strchr(cp, (int)'.'); 295 #else 296 cp = index(cp, '.'); 297 #endif 298 *pp++ = ++cp; 299 } 300 *pp++ = 0; 301 } 302 _res.options |= RES_INIT; 303 return (0); 304 } 305