/* * 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. * 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. */ /* * Portions Copyright (c) 1996-1999 by Internet Software Consortium. * * 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. * * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE * CONSORTIUM 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. */ #if defined(LIBC_SCCS) && !defined(lint) static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93"; static const char rcsid[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixie Exp $"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Options. Should all be left alone. */ #define RESOLVSORT #define RFC1535 /* #undef DEBUG */ static void res_setoptions (res_state, const char *, const char *) internal_function; #ifdef RESOLVSORT static const char sort_mask_chars[] = "/&"; #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL) static u_int32_t net_mask (struct in_addr) __THROW; #endif #if !defined(isascii) /* XXX - could be a function */ # define isascii(c) (!(c & 0200)) #endif #ifdef _LIBC unsigned long long int __res_initstamp attribute_hidden; #endif /* * Resolver state default settings. */ /* * 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_ninit(res_state statp) { extern int __res_vinit(res_state, int); return (__res_vinit(statp, 0)); } #ifdef _LIBC libc_hidden_def (__res_ninit) #endif /* This function has to be reachable by res_data.c but not publically. */ int __res_vinit(res_state statp, int preinit) { FILE *fp; char *cp, **pp; int n; char buf[BUFSIZ]; int nserv = 0; /* number of IPv4 nameservers read from file */ #ifdef _LIBC int nservall = 0; /* number of (IPv4 + IPV6) nameservers read from file */ #endif int haveenv = 0; int havesearch = 0; #ifdef RESOLVSORT int nsort = 0; char *net; #endif #ifndef RFC1535 int dots; #endif #ifdef _LIBC statp->_u._ext.initstamp = __res_initstamp; #endif if (!preinit) { statp->retrans = RES_TIMEOUT; statp->retry = RES_DFLRETRY; statp->options = RES_DEFAULT; statp->id = res_randomid(); } statp->nscount = 0; statp->ndots = 1; statp->pfcode = 0; statp->_vcsock = -1; statp->_flags = 0; statp->qhook = NULL; statp->rhook = NULL; statp->_u._ext.nsinit = 0; statp->_u._ext.nscount = 0; #ifdef _LIBC statp->_u._ext.nscount6 = 0; for (n = 0; n < MAXNS; n++) { statp->_u._ext.nsaddrs[n] = NULL; statp->_u._ext.nsmap[n] = MAXNS; } #endif /* Allow user to override the local domain definition */ if ((cp = getenv("LOCALDOMAIN")) != NULL) { (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); statp->defdname[sizeof(statp->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 = statp->defdname; pp = statp->dnsrch; *pp++ = cp; for (n = 0; *cp && pp < statp->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; } #define MATCH(line, name) \ (!strncmp(line, name, sizeof(name) - 1) && \ (line[sizeof(name) - 1] == ' ' || \ line[sizeof(name) - 1] == '\t')) if ((fp = fopen(_PATH_RESCONF, "rce")) != NULL) { /* No threads use this stream. */ __fsetlocking (fp, FSETLOCKING_BYCALLER); /* read the config file */ while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) { /* skip comments */ if (*buf == ';' || *buf == '#') continue; /* read default domain name */ if (MATCH(buf, "domain")) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof("domain") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); statp->defdname[sizeof(statp->defdname) - 1] = '\0'; if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL) *cp = '\0'; havesearch = 0; continue; } /* set search list */ if (MATCH(buf, "search")) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof("search") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); statp->defdname[sizeof(statp->defdname) - 1] = '\0'; if ((cp = strchr(statp->defdname, '\n')) != NULL) *cp = '\0'; /* * Set search list to be blank-separated strings * on rest of line. */ cp = statp->defdname; pp = statp->dnsrch; *pp++ = cp; for (n = 0; *cp && pp < statp->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 */ #ifdef _LIBC if (MATCH(buf, "nameserver") && nservall < MAXNS) { #else if (MATCH(buf, "nameserver") && nserv < MAXNS) { #endif struct in_addr a; cp = buf + sizeof("nameserver") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp != '\0') && (*cp != '\n') && __inet_aton(cp, &a)) { statp->nsaddr_list[nservall].sin_addr = a; statp->nsaddr_list[nservall].sin_family = AF_INET; statp->nsaddr_list[nservall].sin_port = htons(NAMESERVER_PORT); nserv++; #ifdef _LIBC nservall++; } else { struct in6_addr a6; char *el; if ((el = strpbrk(cp, " \t\n")) != NULL) *el = '\0'; if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL) *el = '\0'; if ((*cp != '\0') && (__inet_pton(AF_INET6, cp, &a6) > 0)) { struct sockaddr_in6 *sa6; sa6 = malloc(sizeof(*sa6)); if (sa6 != NULL) { sa6->sin6_family = AF_INET6; sa6->sin6_port = htons(NAMESERVER_PORT); sa6->sin6_flowinfo = 0; sa6->sin6_addr = a6; if (__glibc_likely (el == NULL)) sa6->sin6_scope_id = 0; else { int try_numericscope = 1; if (IN6_IS_ADDR_LINKLOCAL (&a6) || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) { sa6->sin6_scope_id = __if_nametoindex (el + 1); if (sa6->sin6_scope_id != 0) try_numericscope = 0; } if (try_numericscope) { char *end; sa6->sin6_scope_id = (uint32_t) strtoul (el + 1, &end, 10); if (*end != '\0') sa6->sin6_scope_id = 0; } } statp->_u._ext.nsaddrs[nservall] = sa6; statp->_u._ext.nssocks[nservall] = -1; statp->_u._ext.nsmap[nservall] = MAXNS + 1; nservall++; } } #endif } continue; } #ifdef RESOLVSORT if (MATCH(buf, "sortlist")) { struct in_addr a; cp = buf + sizeof("sortlist") - 1; while (nsort < MAXRESOLVSORT) { while (*cp == ' ' || *cp == '\t') cp++; if (*cp == '\0' || *cp == '\n' || *cp == ';') break; net = cp; while (*cp && !ISSORTMASK(*cp) && *cp != ';' && isascii(*cp) && !isspace(*cp)) cp++; n = *cp; *cp = 0; if (__inet_aton(net, &a)) { statp->sort_list[nsort].addr = a; if (ISSORTMASK(n)) { *cp++ = n; net = cp; while (*cp && *cp != ';' && isascii(*cp) && !isspace(*cp)) cp++; n = *cp; *cp = 0; if (__inet_aton(net, &a)) { statp->sort_list[nsort].mask = a.s_addr; } else { statp->sort_list[nsort].mask = net_mask(statp->sort_list[nsort].addr); } } else { statp->sort_list[nsort].mask = net_mask(statp->sort_list[nsort].addr); } nsort++; } *cp = n; } continue; } #endif if (MATCH(buf, "options")) { res_setoptions(statp, buf + sizeof("options") - 1, "conf"); continue; } } statp->nscount = nservall; #ifdef _LIBC if (nservall - nserv > 0) { statp->_u._ext.nscount6 = nservall - nserv; /* We try IPv6 servers again. */ statp->ipv6_unavail = false; } #endif #ifdef RESOLVSORT statp->nsort = nsort; #endif (void) fclose(fp); } if (__builtin_expect(statp->nscount == 0, 0)) { statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1); statp->nsaddr.sin_family = AF_INET; statp->nsaddr.sin_port = htons(NAMESERVER_PORT); statp->nscount = 1; } if (statp->defdname[0] == 0 && __gethostname(buf, sizeof(statp->defdname) - 1) == 0 && (cp = strchr(buf, '.')) != NULL) strcpy(statp->defdname, cp + 1); /* find components of local domain that might be searched */ if (havesearch == 0) { pp = statp->dnsrch; *pp++ = statp->defdname; *pp = NULL; #ifndef RFC1535 dots = 0; for (cp = statp->defdname; *cp; cp++) dots += (*cp == '.'); cp = statp->defdname; while (pp < statp->dnsrch + MAXDFLSRCH) { if (dots < LOCALDOMAINPARTS) break; cp = __rawmemchr(cp, '.') + 1; /* we know there is one */ *pp++ = cp; dots--; } *pp = NULL; #ifdef DEBUG if (statp->options & RES_DEBUG) { printf(";; res_init()... default dnsrch list:\n"); for (pp = statp->dnsrch; *pp; pp++) printf(";;\t%s\n", *pp); printf(";;\t..END..\n"); } #endif #endif /* !RFC1535 */ } if ((cp = getenv("RES_OPTIONS")) != NULL) res_setoptions(statp, cp, "env"); statp->options |= RES_INIT; return (0); } static void internal_function res_setoptions(res_state statp, const char *options, const char *source) { const char *cp = options; int i; #ifdef DEBUG if (statp->options & RES_DEBUG) printf(";; res_setoptions(\"%s\", \"%s\")...\n", options, source); #endif while (*cp) { /* skip leading and inner runs of spaces */ while (*cp == ' ' || *cp == '\t') cp++; /* search for and process individual options */ if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) { i = atoi(cp + sizeof("ndots:") - 1); if (i <= RES_MAXNDOTS) statp->ndots = i; else statp->ndots = RES_MAXNDOTS; #ifdef DEBUG if (statp->options & RES_DEBUG) printf(";;\tndots=%d\n", statp->ndots); #endif } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) { i = atoi(cp + sizeof("timeout:") - 1); if (i <= RES_MAXRETRANS) statp->retrans = i; else statp->retrans = RES_MAXRETRANS; } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){ i = atoi(cp + sizeof("attempts:") - 1); if (i <= RES_MAXRETRY) statp->retry = i; else statp->retry = RES_MAXRETRY; } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) { #ifdef DEBUG if (!(statp->options & RES_DEBUG)) { printf(";; res_setoptions(\"%s\", \"%s\")..\n", options, source); statp->options |= RES_DEBUG; } printf(";;\tdebug\n"); #endif } else { static const struct { char str[22]; uint8_t len; uint8_t clear; unsigned long int flag; } options[] = { #define STRnLEN(str) str, sizeof (str) - 1 { STRnLEN ("inet6"), 0, RES_USE_INET6 }, { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING }, { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT }, { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT }, { STRnLEN ("rotate"), 0, RES_ROTATE }, { STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME }, { STRnLEN ("edns0"), 0, RES_USE_EDNS0 }, { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP }, { STRnLEN ("single-request"), 0, RES_SNGLKUP }, { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY }, { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY }, { STRnLEN ("use-vc"), 0, RES_USEVC } }; #define noptions (sizeof (options) / sizeof (options[0])) int i; for (i = 0; i < noptions; ++i) if (strncmp (cp, options[i].str, options[i].len) == 0) { if (options[i].clear) statp->options &= options[i].flag; else statp->options |= options[i].flag; break; } if (i == noptions) { /* XXX - print a warning here? */ } } /* skip to next run of spaces */ while (*cp && *cp != ' ' && *cp != '\t') cp++; } } #ifdef RESOLVSORT /* XXX - should really support CIDR which means explicit masks always. */ static u_int32_t net_mask(in) /* XXX - should really use system's version of this */ struct in_addr in; { u_int32_t i = ntohl(in.s_addr); if (IN_CLASSA(i)) return (htonl(IN_CLASSA_NET)); else if (IN_CLASSB(i)) return (htonl(IN_CLASSB_NET)); return (htonl(IN_CLASSC_NET)); } #endif u_int res_randomid(void) { return 0xffff & __getpid(); } #ifdef _LIBC libc_hidden_def (__res_randomid) #endif /* * This routine is for closing the socket if a virtual circuit is used and * the program wants to close it. This provides support for endhostent() * which expects to close the socket. * * This routine is not expected to be user visible. */ void __res_iclose(res_state statp, bool free_addr) { int ns; if (statp->_vcsock >= 0) { close_not_cancel_no_status(statp->_vcsock); statp->_vcsock = -1; statp->_flags &= ~(RES_F_VC | RES_F_CONN); } #ifdef _LIBC for (ns = 0; ns < MAXNS; ns++) #else for (ns = 0; ns < statp->_u._ext.nscount; ns++) #endif if (statp->_u._ext.nsaddrs[ns]) { if (statp->_u._ext.nssocks[ns] != -1) { close_not_cancel_no_status(statp->_u._ext.nssocks[ns]); statp->_u._ext.nssocks[ns] = -1; } if (free_addr) { free (statp->_u._ext.nsaddrs[ns]); statp->_u._ext.nsaddrs[ns] = NULL; } } if (free_addr) statp->_u._ext.nsinit = 0; } libc_hidden_def (__res_iclose) void res_nclose(res_state statp) { __res_iclose (statp, true); } #ifdef _LIBC libc_hidden_def (__res_nclose) #endif #ifdef _LIBC # ifdef _LIBC_REENTRANT /* This is called when a thread is exiting to free resources held in _res. */ static void __attribute__ ((section ("__libc_thread_freeres_fn"))) res_thread_freeres (void) { if (_res.nscount == 0) /* Never called res_ninit. */ return; __res_iclose (&_res, true); /* Close any VC sockets. */ /* Make sure we do a full re-initialization the next time. */ _res.options = 0; } text_set_element (__libc_thread_subfreeres, res_thread_freeres); text_set_element (__libc_subfreeres, res_thread_freeres); # endif #endif