diff options
Diffstat (limited to 'resolv')
| -rw-r--r-- | resolv/res_init.c | 700 |
1 files changed, 366 insertions, 334 deletions
diff --git a/resolv/res_init.c b/resolv/res_init.c index eb8e308fda..49fc94595b 100644 --- a/resolv/res_init.c +++ b/resolv/res_init.c @@ -1,3 +1,21 @@ +/* Resolver state initialization and resolv.conf parsing. + Copyright (C) 1995-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + /* * Copyright (c) 1985, 1989, 1993 * The Regents of the University of California. All rights reserved. @@ -83,26 +101,15 @@ #include <sys/types.h> #include <inet/net-internal.h> -static void res_setoptions (res_state, const char *, const char *) - internal_function; -static u_int32_t net_mask (struct in_addr) __THROW; +static void res_setoptions (res_state, const char *, const char *); +static uint32_t net_mask (struct in_addr); unsigned long long int __res_initstamp attribute_hidden; -/* - * 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_LOOPBACK and the default domain name comes from gethostname. - * - * Return 0 if completes successfully, -1 on error - */ int -res_ninit(res_state statp) { - return (__res_vinit(statp, 0)); +res_ninit (res_state statp) +{ + return __res_vinit (statp, 0); } libc_hidden_def (__res_ninit) @@ -114,349 +121,374 @@ is_sort_mask (char ch) return ch == '/' || ch == '&'; } -/* This function has to be reachable by res_data.c but not publically. */ +/* Set up default settings. If the /etc/resolv.conf configuration + file exist, the values there will have precedence. Otherwise, the + server address is set to INADDR_LOOPBACK and the default domain + name comes from gethostname. The RES_OPTIONS and LOCALDOMAIN + environment variables can be used to override some settings. + Return 0 if completes successfully, -1 on error. */ int -__res_vinit(res_state statp, int preinit) { - FILE *fp; - char *cp, **pp; - int n; - char buf[BUFSIZ]; - int nserv = 0; /* number of nameservers read from file */ - int have_serv6 = 0; - int haveenv = 0; - int havesearch = 0; - int nsort = 0; - char *net; - statp->_u._ext.initstamp = __res_initstamp; +__res_vinit (res_state statp, int preinit) +{ + char *cp, **pp; + char buf[BUFSIZ]; + int nserv = 0; /* Number of nameservers read from file. */ + bool have_serv6 = false; + bool haveenv = false; + bool havesearch = false; + int nsort = 0; + char *net; + statp->_u._ext.initstamp = __res_initstamp; - if (!preinit) { - statp->retrans = RES_TIMEOUT; - statp->retry = RES_DFLRETRY; - statp->options = RES_DEFAULT; - statp->id = res_randomid(); - } + if (!preinit) + { + statp->retrans = RES_TIMEOUT; + statp->retry = RES_DFLRETRY; + statp->options = RES_DEFAULT; + statp->id = res_randomid (); + } - statp->nscount = 0; - statp->defdname[0] = '\0'; - statp->ndots = 1; - statp->pfcode = 0; - statp->_vcsock = -1; - statp->_flags = 0; - statp->__glibc_unused_qhook = NULL; - statp->__glibc_unused_rhook = NULL; - statp->_u._ext.nscount = 0; - for (n = 0; n < MAXNS; n++) - statp->_u._ext.nsaddrs[n] = NULL; + statp->nscount = 0; + statp->defdname[0] = '\0'; + statp->ndots = 1; + statp->pfcode = 0; + statp->_vcsock = -1; + statp->_flags = 0; + statp->__glibc_unused_qhook = NULL; + statp->__glibc_unused_rhook = NULL; + statp->_u._ext.nscount = 0; + for (int n = 0; n < MAXNS; n++) + statp->_u._ext.nsaddrs[n] = NULL; - /* 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++; + /* Allow user to override the local domain definition. */ + if ((cp = getenv ("LOCALDOMAIN")) != NULL) + { + strncpy (statp->defdname, cp, sizeof (statp->defdname) - 1); + statp->defdname[sizeof (statp->defdname) - 1] = '\0'; + haveenv = true; - /* - * 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; - } + /* 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 (int n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) + { + if (*cp == '\n') + break; + else if (*cp == ' ' || *cp == '\t') + { + *cp = 0; + n = 1; + } + else if (n > 0) + { + *pp++ = cp; + n = 0; + havesearch = true; + } + } + /* 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')) +#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 */ - if (MATCH(buf, "nameserver") && nserv < MAXNS) { - struct in_addr a; + FILE *fp = fopen (_PATH_RESCONF, "rce"); + if (fp != 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) + /* LOCALDOMAIN overrides the configuration file. */ + 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 = false; + continue; + } + /* Set search list. */ + if (MATCH (buf, "search")) + { + if (haveenv) + /* LOCALDOMAIN overrides the configuration file. */ + 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 (int 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 = true; + continue; + } + /* Read nameservers to query. */ + if (MATCH (buf, "nameserver") && 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)) { - statp->nsaddr_list[nserv].sin_addr = a; - statp->nsaddr_list[nserv].sin_family = AF_INET; - statp->nsaddr_list[nserv].sin_port = - htons(NAMESERVER_PORT); - nserv++; - } else { - struct in6_addr a6; - char *el; + cp = buf + sizeof ("nameserver") - 1; + while (*cp == ' ' || *cp == '\t') + cp++; + if ((*cp != '\0') && (*cp != '\n') && __inet_aton (cp, &a)) + { + statp->nsaddr_list[nserv].sin_addr = a; + statp->nsaddr_list[nserv].sin_family = AF_INET; + statp->nsaddr_list[nserv].sin_port = htons (NAMESERVER_PORT); + nserv++; + } + 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; + 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; + 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; - sa6->sin6_scope_id = 0; - if (__glibc_likely (el != NULL)) { - /* Ignore errors, for backwards - compatibility. */ - (void) __inet6_scopeid_pton - (&a6, el + 1, &sa6->sin6_scope_id); - } + sa6->sin6_scope_id = 0; + if (__glibc_likely (el != NULL)) + /* Ignore errors, for backwards + compatibility. */ + __inet6_scopeid_pton + (&a6, el + 1, &sa6->sin6_scope_id); - statp->nsaddr_list[nserv].sin_family = 0; - statp->_u._ext.nsaddrs[nserv] = sa6; - statp->_u._ext.nssocks[nserv] = -1; - have_serv6 = 1; - nserv++; - } - } - } - continue; - } - if (MATCH(buf, "sortlist")) { - struct in_addr a; + statp->nsaddr_list[nserv].sin_family = 0; + statp->_u._ext.nsaddrs[nserv] = sa6; + statp->_u._ext.nssocks[nserv] = -1; + have_serv6 = true; + nserv++; + } + } + } + continue; + } + 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 && !is_sort_mask (*cp) && *cp != ';' && - isascii(*cp) && !isspace(*cp)) - cp++; - n = *cp; - *cp = 0; - if (__inet_aton(net, &a)) { - statp->sort_list[nsort].addr = a; - if (is_sort_mask (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; - } - if (MATCH(buf, "options")) { - res_setoptions(statp, buf + sizeof("options") - 1, "conf"); - continue; - } - } - statp->nscount = nserv; - if (have_serv6) { - /* We try IPv6 servers again. */ - statp->ipv6_unavail = false; - } - statp->nsort = nsort; - (void) fclose(fp); - } - if (__glibc_unlikely (statp->nscount == 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); + cp = buf + sizeof ("sortlist") - 1; + while (nsort < MAXRESOLVSORT) + { + while (*cp == ' ' || *cp == '\t') + cp++; + if (*cp == '\0' || *cp == '\n' || *cp == ';') + break; + net = cp; + while (*cp && !is_sort_mask (*cp) && *cp != ';' + && isascii (*cp) && !isspace (*cp)) + cp++; + char separator = *cp; + *cp = 0; + if (__inet_aton (net, &a)) + { + statp->sort_list[nsort].addr = a; + if (is_sort_mask (separator)) + { + *cp++ = separator; + net = cp; + while (*cp && *cp != ';' + && isascii (*cp) && !isspace (*cp)) + cp++; + separator = *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 = separator; + } + continue; + } + if (MATCH (buf, "options")) + { + res_setoptions (statp, buf + sizeof ("options") - 1, "conf"); + continue; + } + } + statp->nscount = nserv; + if (have_serv6) + /* We try IPv6 servers again. */ + statp->ipv6_unavail = false; + statp->nsort = nsort; + fclose (fp); + } + if (__glibc_unlikely (statp->nscount == 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; + /* Find components of local domain that might be searched. */ + if (!havesearch) + { + pp = statp->dnsrch; + *pp++ = statp->defdname; + *pp = NULL; - } + } - if ((cp = getenv("RES_OPTIONS")) != NULL) - res_setoptions(statp, cp, "env"); - statp->options |= RES_INIT; - return (0); + 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; +res_setoptions (res_state statp, const char *options, const char *source) +{ + const char *cp = options; - 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; - } 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 { - static const struct - { - char str[22]; - uint8_t len; - uint8_t clear; - unsigned long int flag; - } options[] = { + 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)) + { + int i = atoi (cp + sizeof ("ndots:") - 1); + if (i <= RES_MAXNDOTS) + statp->ndots = i; + else + statp->ndots = RES_MAXNDOTS; + } + else if (!strncmp (cp, "timeout:", sizeof ("timeout:") - 1)) + { + int 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)) + { + int i = atoi (cp + sizeof ("attempts:") - 1); + if (i <= RES_MAXRETRY) + statp->retry = i; + else + statp->retry = RES_MAXRETRY; + } + 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, DEPRECATED_RES_USE_INET6 }, - { STRnLEN ("rotate"), 0, RES_ROTATE }, - { 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 } - }; + { STRnLEN ("inet6"), 0, DEPRECATED_RES_USE_INET6 }, + { STRnLEN ("rotate"), 0, RES_ROTATE }, + { 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++; - } + for (int 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; + } + } + /* Skip to next run of spaces. */ + while (*cp && *cp != ' ' && *cp != '\t') + cp++; + } } -/* XXX - should really support CIDR which means explicit masks always. */ -/* XXX - should really use system's version of this */ -static u_int32_t +static uint32_t net_mask (struct in_addr in) { - u_int32_t i = ntohl(in.s_addr); + uint32_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)); + if (IN_CLASSA (i)) + return htonl (IN_CLASSA_NET); + else if (IN_CLASSB (i)) + return htonl (IN_CLASSB_NET); + return htonl (IN_CLASSC_NET); } |