/* $Id: res_init.c,v 1.1.1.1 2006/09/14 01:59:06 root Exp $ */ /* $OpenBSD: res_init.c,v 1.18 1999/09/03 21:14:51 deraadt Exp $ */ /* * ++Copyright++ 1985, 1989, 1993 * - * 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-- */ #include #include #include #include #include #include #include #include #include #include #include #include #include /*-------------------------------------- info about "sortlist" -------------- * Marc Majka 1994/04/16 * Allan Nathanson 1994/10/29 (BIND 4.9.3.x) * * NetInfo resolver configuration directory support. * * Allow a NetInfo directory to be created in the hierarchy which * contains the same information as the resolver configuration file. * * - The local domain name is stored as the value of the "domain" property. * - The Internet address(es) of the name server(s) are stored as values * of the "nameserver" property. * - The name server addresses are stored as values of the "nameserver" * property. * - The search list for host-name lookup is stored as values of the * "search" property. * - The sortlist comprised of IP address netmask pairs are stored as * values of the "sortlist" property. The IP address and optional netmask * should be seperated by a slash (/) or ampersand (&) character. * - Internal resolver variables can be set from the value of the "options" * property. */ #ifndef PMON static void res_setoptions __P((char *, char *)); #endif #ifdef RESOLVSORT static const char sort_mask[] = "/&"; #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL) static u_int32_t net_mask __P((struct in_addr)); #endif /* * Resolver state default settings. */ struct __res_state _res # if defined(__BIND_RES_TEXT) = { RES_TIMEOUT, } /* Motorola, et al. */ # endif ; /* * 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(). * * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1 * rather than INADDR_ANY ("0.0.0.0") as the default name server address * since it was noted that INADDR_ANY actually meant ``the first interface * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface, * it had to be "up" in order for you to reach your own name server. It * was later decided that since the recommended practice is to always * install local static routes through 127.0.0.1 for all your network * interfaces, that we could solve this problem without a code change. * * The configuration file should always be used, since it is the only way * to specify a default domain. If you are running a server on your local * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1" * in the configuration file. * * Return 0 if completes successfully, -1 on error */ int res_init() { int nserv = 0; /* number of nameserver records read from file */ char buf[MAXHOSTNAMELEN]; register char *cp, **pp; register int n; int haveenv = 0; int havesearch = 0; #ifndef RFC1535 int dots; #endif /* * These three fields used to be statically initialized. This made * it hard to use this code in a shared library. It is necessary, * now that we're doing dynamic initialization here, that we preserve * the old semantics: if an application modifies one of these three * fields of _res before res_init() is called, res_init() will not * alter them. Of course, if an application is setting them to * _zero_ before calling res_init(), hoping to override what used * to be the static default, we can't detect it and unexpected results * will follow. Zero for any of these fields would make no sense, * so one can safely assume that the applications were already getting * unexpected results. * * _res.options is tricky since some apps were known to diddle the bits * before res_init() was first called. We can't replicate that semantic * with dynamic initialization (they may have turned bits off that are * set in RES_DEFAULT). Our solution is to declare such applications * "broken". They could fool us by setting RES_INIT but none do (yet). */ if (!_res.retrans) _res.retrans = RES_TIMEOUT; if (!_res.retry) _res.retry = 4; if (!(_res.options & RES_INIT)) _res.options = RES_DEFAULT; _res.nsaddr.sin_addr.s_addr = INADDR_ANY; _res.nsaddr.sin_family = AF_INET; _res.nsaddr.sin_port = htons(NAMESERVER_PORT); _res.nscount = 1; _res.ndots = 1; _res.pfcode = 0; strncpy(_res.lookups, "f", sizeof _res.lookups); /* Allow user to override the local domain definition */ if ((cp = getenv("localdomain")) != NULL) { (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1); _res.defdname[sizeof(_res.defdname) - 1] = '\0'; haveenv++; /* * Set search list to be blank-separated strings * from rest of env value. Permits users of LOCALDOMAIN * to still have a search list, and anyone to set the * one that they want to use as an individual (even more * important now that the rfc1535 stuff restricts searches) */ cp = _res.defdname; pp = _res.dnsrch; *pp++ = cp; for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) { if (*cp == '\n') /* silly backwards compat */ break; else if (*cp == ' ' || *cp == '\t') { *cp = 0; n = 1; } else if (n) { *pp++ = cp; n = 0; havesearch = 1; } } /* null terminate last domain if there are excess */ while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n') cp++; *cp = '\0'; *pp++ = 0; } if ((cp = getenv("nameserver")) != NULL) { char *ep; strncpy (buf, cp, sizeof(buf)-1); for (cp = buf; cp && *cp; cp = ep) { if (*cp == ' ' || *cp == '\t') { cp++; continue; } ep = strpbrk(cp, " \t"); if (ep != NULL) *ep++ = '\0'; if ((_res.nsaddr_list[nserv].sin_addr.s_addr = inet_addr(cp)) == (unsigned)-1) { _res.nsaddr_list[nserv].sin_addr.s_addr = INADDR_ANY; continue; } _res.nsaddr_list[nserv].sin_family = AF_INET; _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT); nserv++; } } if (nserv > 1) _res.nscount = nserv; if (_res.defdname[0] == 0 && gethostname(buf, sizeof(_res.defdname) - 1) == 0 && (cp = strchr(buf, '.')) != NULL) { strncpy(_res.defdname, cp + 1, sizeof(_res.defdname) - 1); _res.defdname[sizeof(_res.defdname) - 1] = '\0'; } /* find components of local domain that might be searched */ if (havesearch == 0) { pp = _res.dnsrch; *pp++ = _res.defdname; *pp = NULL; #ifndef RFC1535 dots = 0; for (cp = _res.defdname; *cp; cp++) dots += (*cp == '.'); cp = _res.defdname; while (pp < _res.dnsrch + MAXDFLSRCH) { if (dots < LOCALDOMAINPARTS) break; cp = strchr(cp, '.') + 1; /* we know there is one */ *pp++ = cp; dots--; } *pp = NULL; #ifdef DEBUG if (_res.options & RES_DEBUG) { printf(";; res_init()... default dnsrch list:\n"); for (pp = _res.dnsrch; *pp; pp++) printf(";;\t%s\n", *pp); printf(";;\t..END..\n"); } #endif /* DEBUG */ #endif /* !RFC1535 */ } _res.options |= RES_INIT; return (0); }