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-rw-r--r--resolv/res_hconf.c572
1 files changed, 0 insertions, 572 deletions
diff --git a/resolv/res_hconf.c b/resolv/res_hconf.c
deleted file mode 100644
index 8fc06e9abd..0000000000
--- a/resolv/res_hconf.c
+++ /dev/null
@@ -1,572 +0,0 @@
-/* Copyright (C) 1993-2017 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by David Mosberger (davidm@azstarnet.com).
-
- 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/>. */
-
-/* This file provides a Linux /etc/host.conf compatible front end to
- the various name resolvers (/etc/hosts, named, NIS server, etc.).
- Though mostly compatibly, the following differences exist compared
- to the original implementation:
-
- - line comments can appear anywhere (not just at the beginning of
- a line)
-*/
-
-#include <assert.h>
-#include <errno.h>
-#include <ctype.h>
-#include <libintl.h>
-#include <memory.h>
-#include <stdio.h>
-#include <stdio_ext.h>
-#include <stdlib.h>
-#include <string.h>
-#include <net/if.h>
-#include <sys/ioctl.h>
-#include <unistd.h>
-#include <netinet/in.h>
-#include <libc-lock.h>
-#include "ifreq.h"
-#include "res_hconf.h"
-#include <wchar.h>
-#include <atomic.h>
-
-#if IS_IN (libc)
-# define fgets_unlocked __fgets_unlocked
-#endif
-
-#define _PATH_HOSTCONF "/etc/host.conf"
-
-/* Environment vars that all user to override default behavior: */
-#define ENV_HOSTCONF "RESOLV_HOST_CONF"
-#define ENV_TRIM_OVERR "RESOLV_OVERRIDE_TRIM_DOMAINS"
-#define ENV_TRIM_ADD "RESOLV_ADD_TRIM_DOMAINS"
-#define ENV_MULTI "RESOLV_MULTI"
-#define ENV_REORDER "RESOLV_REORDER"
-
-enum parse_cbs
- {
- CB_none,
- CB_arg_trimdomain_list,
- CB_arg_bool
- };
-
-static const struct cmd
-{
- const char name[11];
- uint8_t cb;
- unsigned int arg;
-} cmd[] =
-{
- {"order", CB_none, 0},
- {"trim", CB_arg_trimdomain_list, 0},
- {"multi", CB_arg_bool, HCONF_FLAG_MULTI},
- {"reorder", CB_arg_bool, HCONF_FLAG_REORDER}
-};
-
-/* Structure containing the state. */
-struct hconf _res_hconf;
-
-/* Skip white space. */
-static const char *
-skip_ws (const char *str)
-{
- while (isspace (*str)) ++str;
- return str;
-}
-
-
-/* Skip until whitespace, comma, end of line, or comment character. */
-static const char *
-skip_string (const char *str)
-{
- while (*str && !isspace (*str) && *str != '#' && *str != ',')
- ++str;
- return str;
-}
-
-
-static const char *
-arg_trimdomain_list (const char *fname, int line_num, const char *args)
-{
- const char * start;
- size_t len;
-
- do
- {
- start = args;
- args = skip_string (args);
- len = args - start;
-
- if (_res_hconf.num_trimdomains >= TRIMDOMAINS_MAX)
- {
- char *buf;
-
- if (__asprintf (&buf, _("\
-%s: line %d: cannot specify more than %d trim domains"),
- fname, line_num, TRIMDOMAINS_MAX) < 0)
- return 0;
-
- __fxprintf (NULL, "%s", buf);
-
- free (buf);
- return 0;
- }
- _res_hconf.trimdomain[_res_hconf.num_trimdomains++] =
- __strndup (start, len);
- args = skip_ws (args);
- switch (*args)
- {
- case ',': case ';': case ':':
- args = skip_ws (++args);
- if (!*args || *args == '#')
- {
- char *buf;
-
- if (__asprintf (&buf, _("\
-%s: line %d: list delimiter not followed by domain"),
- fname, line_num) < 0)
- return 0;
-
- __fxprintf (NULL, "%s", buf);
-
- free (buf);
- return 0;
- }
- default:
- break;
- }
- }
- while (*args && *args != '#');
- return args;
-}
-
-
-static const char *
-arg_bool (const char *fname, int line_num, const char *args, unsigned flag)
-{
- if (__strncasecmp (args, "on", 2) == 0)
- {
- args += 2;
- _res_hconf.flags |= flag;
- }
- else if (__strncasecmp (args, "off", 3) == 0)
- {
- args += 3;
- _res_hconf.flags &= ~flag;
- }
- else
- {
- char *buf;
-
- if (__asprintf (&buf,
- _("%s: line %d: expected `on' or `off', found `%s'\n"),
- fname, line_num, args) < 0)
- return 0;
-
- __fxprintf (NULL, "%s", buf);
-
- free (buf);
- return 0;
- }
- return args;
-}
-
-
-static void
-parse_line (const char *fname, int line_num, const char *str)
-{
- const char *start;
- const struct cmd *c = 0;
- size_t len;
- size_t i;
-
- str = skip_ws (str);
-
- /* skip line comment and empty lines: */
- if (*str == '\0' || *str == '#') return;
-
- start = str;
- str = skip_string (str);
- len = str - start;
-
- for (i = 0; i < sizeof (cmd) / sizeof (cmd[0]); ++i)
- {
- if (__strncasecmp (start, cmd[i].name, len) == 0
- && strlen (cmd[i].name) == len)
- {
- c = &cmd[i];
- break;
- }
- }
- if (c == NULL)
- {
- char *buf;
-
- if (__asprintf (&buf, _("%s: line %d: bad command `%s'\n"),
- fname, line_num, start) < 0)
- return;
-
- __fxprintf (NULL, "%s", buf);
-
- free (buf);
- return;
- }
-
- /* process args: */
- str = skip_ws (str);
-
- if (c->cb == CB_arg_trimdomain_list)
- str = arg_trimdomain_list (fname, line_num, str);
- else if (c->cb == CB_arg_bool)
- str = arg_bool (fname, line_num, str, c->arg);
- else
- /* Ignore the line. */
- return;
-
- if (!str)
- return;
-
- /* rest of line must contain white space or comment only: */
- while (*str)
- {
- if (!isspace (*str)) {
- if (*str != '#')
- {
- char *buf;
-
- if (__asprintf (&buf,
- _("%s: line %d: ignoring trailing garbage `%s'\n"),
- fname, line_num, str) < 0)
- break;
-
- __fxprintf (NULL, "%s", buf);
-
- free (buf);
- }
- break;
- }
- ++str;
- }
-}
-
-
-static void
-do_init (void)
-{
- const char *hconf_name;
- int line_num = 0;
- char buf[256], *envval;
- FILE *fp;
-
- memset (&_res_hconf, '\0', sizeof (_res_hconf));
-
- hconf_name = getenv (ENV_HOSTCONF);
- if (hconf_name == NULL)
- hconf_name = _PATH_HOSTCONF;
-
- fp = fopen (hconf_name, "rce");
- if (fp)
- {
- /* No threads using this stream. */
- __fsetlocking (fp, FSETLOCKING_BYCALLER);
-
- while (fgets_unlocked (buf, sizeof (buf), fp))
- {
- ++line_num;
- *__strchrnul (buf, '\n') = '\0';
- parse_line (hconf_name, line_num, buf);
- }
- fclose (fp);
- }
-
- envval = getenv (ENV_MULTI);
- if (envval)
- arg_bool (ENV_MULTI, 1, envval, HCONF_FLAG_MULTI);
-
- envval = getenv (ENV_REORDER);
- if (envval)
- arg_bool (ENV_REORDER, 1, envval, HCONF_FLAG_REORDER);
-
- envval = getenv (ENV_TRIM_ADD);
- if (envval)
- arg_trimdomain_list (ENV_TRIM_ADD, 1, envval);
-
- envval = getenv (ENV_TRIM_OVERR);
- if (envval)
- {
- _res_hconf.num_trimdomains = 0;
- arg_trimdomain_list (ENV_TRIM_OVERR, 1, envval);
- }
-
- /* See comments on the declaration of _res_hconf. */
- atomic_store_release (&_res_hconf.initialized, 1);
-}
-
-
-/* Initialize hconf datastructure by reading host.conf file and
- environment variables. */
-void
-_res_hconf_init (void)
-{
- __libc_once_define (static, once);
-
- __libc_once (once, do_init);
-}
-
-
-#if IS_IN (libc)
-# if defined SIOCGIFCONF && defined SIOCGIFNETMASK
-/* List of known interfaces. */
-libc_freeres_ptr (
-static struct netaddr
-{
- int addrtype;
- union
- {
- struct
- {
- u_int32_t addr;
- u_int32_t mask;
- } ipv4;
- } u;
-} *ifaddrs);
-# endif
-
-/* Reorder addresses returned in a hostent such that the first address
- is an address on the local subnet, if there is such an address.
- Otherwise, nothing is changed.
-
- Note that this function currently only handles IPv4 addresses. */
-
-void
-_res_hconf_reorder_addrs (struct hostent *hp)
-{
-#if defined SIOCGIFCONF && defined SIOCGIFNETMASK
- int i, j;
- /* Number of interfaces. Also serves as a flag for the
- double-checked locking idiom. */
- static int num_ifs = -1;
- /* Local copy of num_ifs, for non-atomic access. */
- int num_ifs_local;
- /* We need to protect the dynamic buffer handling. The lock is only
- acquired during initialization. Afterwards, a positive num_ifs
- value indicates completed initialization. */
- __libc_lock_define_initialized (static, lock);
-
- /* Only reorder if we're supposed to. */
- if ((_res_hconf.flags & HCONF_FLAG_REORDER) == 0)
- return;
-
- /* Can't deal with anything but IPv4 for now... */
- if (hp->h_addrtype != AF_INET)
- return;
-
- /* This load synchronizes with the release MO store in the
- initialization block below. */
- num_ifs_local = atomic_load_acquire (&num_ifs);
- if (num_ifs_local <= 0)
- {
- struct ifreq *ifr, *cur_ifr;
- int sd, num, i;
- /* Save errno. */
- int save = errno;
-
- /* Initialize interface table. */
-
- /* The SIOCGIFNETMASK ioctl will only work on an AF_INET socket. */
- sd = __socket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
- if (sd < 0)
- return;
-
- /* Get lock. */
- __libc_lock_lock (lock);
-
- /* Recheck, somebody else might have done the work by now. No
- ordering is required for the load because we have the lock,
- and num_ifs is only updated under the lock. Also see (3) in
- the analysis below. */
- num_ifs_local = atomic_load_relaxed (&num_ifs);
- if (num_ifs_local <= 0)
- {
- /* This is the only block which writes to num_ifs. It can
- be executed several times (sequentially) if
- initialization does not yield any interfaces, and num_ifs
- remains zero. However, once we stored a positive value
- in num_ifs below, this block cannot be entered again due
- to the condition above. */
- int new_num_ifs = 0;
-
- /* Get a list of interfaces. */
- __ifreq (&ifr, &num, sd);
- if (!ifr)
- goto cleanup;
-
- ifaddrs = malloc (num * sizeof (ifaddrs[0]));
- if (!ifaddrs)
- goto cleanup1;
-
- /* Copy usable interfaces in ifaddrs structure. */
- for (cur_ifr = ifr, i = 0; i < num;
- cur_ifr = __if_nextreq (cur_ifr), ++i)
- {
- union
- {
- struct sockaddr sa;
- struct sockaddr_in sin;
- } ss;
-
- if (cur_ifr->ifr_addr.sa_family != AF_INET)
- continue;
-
- ifaddrs[new_num_ifs].addrtype = AF_INET;
- ss.sa = cur_ifr->ifr_addr;
- ifaddrs[new_num_ifs].u.ipv4.addr = ss.sin.sin_addr.s_addr;
-
- if (__ioctl (sd, SIOCGIFNETMASK, cur_ifr) < 0)
- continue;
-
- ss.sa = cur_ifr->ifr_netmask;
- ifaddrs[new_num_ifs].u.ipv4.mask = ss.sin.sin_addr.s_addr;
-
- /* Now we're committed to this entry. */
- ++new_num_ifs;
- }
- /* Just keep enough memory to hold all the interfaces we want. */
- ifaddrs = realloc (ifaddrs, new_num_ifs * sizeof (ifaddrs[0]));
- assert (ifaddrs != NULL);
-
- cleanup1:
- __if_freereq (ifr, num);
-
- cleanup:
- /* Release lock, preserve error value, and close socket. */
- errno = save;
-
- /* Advertise successful initialization if new_num_ifs is
- positive (and no updates to ifaddrs are permitted after
- that). Otherwise, num_ifs remains unchanged, at zero.
- This store synchronizes with the initial acquire MO
- load. */
- atomic_store_release (&num_ifs, new_num_ifs);
- /* Keep the local copy current, to save another load. */
- num_ifs_local = new_num_ifs;
- }
-
- __libc_lock_unlock (lock);
-
- __close (sd);
- }
-
- /* num_ifs_local cannot be negative because the if statement above
- covered this case. It can still be zero if we just performed
- initialization, but could not find any interfaces. */
- if (num_ifs_local == 0)
- return;
-
- /* The code below accesses ifaddrs, so we need to ensure that the
- initialization happens-before this point.
-
- The actual initialization is sequenced-before the release store
- to num_ifs, and sequenced-before the end of the critical section.
-
- This means there are three possible executions:
-
- (1) The thread that initialized the data also uses it, so
- sequenced-before is sufficient to ensure happens-before.
-
- (2) The release MO store of num_ifs synchronizes-with the acquire
- MO load, and the acquire MO load is sequenced before the use
- of the initialized data below.
-
- (3) We enter the critical section, and the relaxed MO load of
- num_ifs yields a positive value. The write to ifaddrs is
- sequenced-before leaving the critical section. Leaving the
- critical section happens-before we entered the critical
- section ourselves, which means that the write to ifaddrs
- happens-before this point.
-
- Consequently, all potential writes to ifaddrs (and the data it
- points to) happens-before this point. */
-
- /* Find an address for which we have a direct connection. */
- for (i = 0; hp->h_addr_list[i]; ++i)
- {
- struct in_addr *haddr = (struct in_addr *) hp->h_addr_list[i];
-
- for (j = 0; j < num_ifs_local; ++j)
- {
- u_int32_t if_addr = ifaddrs[j].u.ipv4.addr;
- u_int32_t if_netmask = ifaddrs[j].u.ipv4.mask;
-
- if (((haddr->s_addr ^ if_addr) & if_netmask) == 0)
- {
- void *tmp;
-
- tmp = hp->h_addr_list[i];
- hp->h_addr_list[i] = hp->h_addr_list[0];
- hp->h_addr_list[0] = tmp;
- return;
- }
- }
- }
-#endif /* defined(SIOCGIFCONF) && ... */
-}
-
-
-/* If HOSTNAME has a postfix matching any of the trimdomains, trim away
- that postfix. Notice that HOSTNAME is modified inplace. Also, the
- original code applied all trimdomains in order, meaning that the
- same domainname could be trimmed multiple times. I believe this
- was unintentional. */
-void
-_res_hconf_trim_domain (char *hostname)
-{
- size_t hostname_len, trim_len;
- int i;
-
- hostname_len = strlen (hostname);
-
- for (i = 0; i < _res_hconf.num_trimdomains; ++i)
- {
- const char *trim = _res_hconf.trimdomain[i];
-
- trim_len = strlen (trim);
- if (hostname_len > trim_len
- && __strcasecmp (&hostname[hostname_len - trim_len], trim) == 0)
- {
- hostname[hostname_len - trim_len] = '\0';
- break;
- }
- }
-}
-
-
-/* Trim all hostnames/aliases in HP according to the trimdomain list.
- Notice that HP is modified inplace! */
-void
-_res_hconf_trim_domains (struct hostent *hp)
-{
- int i;
-
- if (_res_hconf.num_trimdomains == 0)
- return;
-
- _res_hconf_trim_domain (hp->h_name);
- for (i = 0; hp->h_aliases[i]; ++i)
- _res_hconf_trim_domain (hp->h_aliases[i]);
-}
-#endif
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