/*- * Copyright (c) 1985, 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * Portions Copyright (c) 1993 by Digital Equipment Corporation. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies, and that * the name of Digital Equipment Corporation not be used in advertising or * publicity pertaining to distribution of the document or software without * specific, written prior permission. * * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS * SOFTWARE. * - * --Copyright-- */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93"; static char rcsid[] = "$Id: res_init.c,v 4.9.1.1 1993/05/02 22:43:03 vixie Rel $"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include #include #include #include /* * Resolver state default settings */ struct __res_state _res = { RES_TIMEOUT, /* retransmition time interval */ 4, /* number of times to retransmit */ RES_DEFAULT, /* options flags */ 1, /* number of name servers */ }; /* * Set up default settings. If the configuration file exist, the values * there will have precedence. Otherwise, the server address is set to * INADDR_ANY and the default domain name comes from the gethostname(). * * The configuration file should only be used if you want to redefine your * domain or run without a server on your machine. * * Return 0 if completes successfully, -1 on error */ res_init() { register FILE *fp; register char *cp, **pp; register int n; char buf[BUFSIZ]; int nserv = 0; /* number of nameserver records read from file */ int haveenv = 0; int havesearch = 0; #ifdef USELOOPBACK _res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1); #else _res.nsaddr.sin_addr.s_addr = INADDR_ANY; #endif _res.nsaddr.sin_family = AF_INET; _res.nsaddr.sin_port = htons(NAMESERVER_PORT); _res.nscount = 1; _res.pfcode = 0; /* Allow user to override the local domain definition */ if ((cp = getenv("LOCALDOMAIN")) != NULL) { (void)strncpy(_res.defdname, cp, sizeof(_res.defdname)); if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL) *cp = '\0'; haveenv++; } if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) { /* read the config file */ while (fgets(buf, sizeof(buf), fp) != NULL) { /* skip comments */ if ((*buf == ';') || (*buf == '#')) continue; /* read default domain name */ if (!strncmp(buf, "domain", sizeof("domain") - 1)) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof("domain") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1); if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL) *cp = '\0'; havesearch = 0; continue; } /* set search list */ if (!strncmp(buf, "search", sizeof("search") - 1)) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof("search") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1); if ((cp = strchr(_res.defdname, '\n')) != NULL) *cp = '\0'; /* * Set search list to be blank-separated strings * on rest of line. */ cp = _res.defdname; pp = _res.dnsrch; *pp++ = cp; for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) { if (*cp == ' ' || *cp == '\t') { *cp = 0; n = 1; } else if (n) { *pp++ = cp; n = 0; } } /* null terminate last domain if there are excess */ while (*cp != '\0' && *cp != ' ' && *cp != '\t') cp++; *cp = '\0'; *pp++ = 0; havesearch = 1; continue; } /* read nameservers to query */ if (!strncmp(buf, "nameserver", sizeof("nameserver") - 1) && nserv < MAXNS) { struct in_addr a; cp = buf + sizeof("nameserver") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) { _res.nsaddr_list[nserv].sin_addr = a; _res.nsaddr_list[nserv].sin_family = AF_INET; _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT); nserv++; } continue; } } if (nserv > 1) _res.nscount = nserv; (void) fclose(fp); } if (_res.defdname[0] == 0) { if (gethostname(buf, sizeof(_res.defdname)) == 0 && (cp = strchr(buf, '.'))) (void)strcpy(_res.defdname, cp + 1); } /* find components of local domain that might be searched */ if (havesearch == 0) { pp = _res.dnsrch; *pp++ = _res.defdname; for (cp = _res.defdname, n = 0; *cp; cp++) if (*cp == '.') n++; cp = _res.defdname; for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH; n--) { cp = strchr(cp, '.'); *pp++ = ++cp; } *pp++ = 0; } _res.options |= RES_INIT; return (0); }