glibc/resolv/res_hconf.c

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Wed May 22 22:10:01 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * stdlib/canonicalize.c: New file. * stdlib/stdlib.h: Declare canonicalize_file_name, realpath. * stdlib/Makefile (routines): Add canonicalize. * posix/unistd.h: Declare __canonicalize_directory_name_internal. Thu May 23 00:01:10 1996 Ulrich Drepper <drepper@cygnus.com> * db/recno/rec_seq.c: Prevent `sccsid' definition by using the same #if condition as in the other db files. * intl/Makefile: Add -Wno-unused CFLAGS for compilation of bindtextdom.c, finddomain.c, and localealias.c. * intl/dcgettext.c: Don't define prototype for getcwd() when compiling in glibc. * libio/cleanup.c: Add prototype for _IO_register_cleanup. * libio/filedoalloc.c, libio/fileops.c, libio/iopopen.c: Don't define _POSIX_SOURCE unconditionally. * libio/filedoalloc.c, libio/iopopen.c: Include <unistd.h> if compiling in glibc. * libio/fileops.c (_IO_file_close_it): Don't sync file, call flush instead. This relaxes the rules from POSIX.1 about changing the active handle a bit. * libio/iofopncook.c (struct _IO_cookie_file): Move definition into <libio.h>. Add prototypes for local functions to prevent warnings. * libio/iopopen.c: Change prototypes for _IO_fork, _IO_pipe, and _IO_DUP2 to contain complete parameter list. * libio/libio.h: Add definition of struct _IO_cookie_file. * libio/libioP.h: Add prototypes for _IO_vasprintf, _IO_vdprintf, and _IO_vsnprintf. * libio/memstream.c: Include <stdio.h>. * libio/stdio.h: Add prototypes for fopencookie, __stdio_gen_tempname, __vfscanf, __vsscanf, and __vsnprintf. * libio/strops.c: Avoid useless expression in `for' initializer. * locale/findlocale.c: Add some casts to prevent warnings. * locale/programs/locfile.c (write_locale_data): Don't use double `/' in locale binary file. * posix/unistd.h: Remove prototype for `reboot'. Update from bind-4.9.4-T1A. * resolv/Makefile (routines): Add inet_ntop and inet_pton. * resolv/arpa/nameser.h: Add definition of IN6ADDRSZ. * resolv/gethnamaddr.c, resolv/getnetnamadr.c, resolv/res_comp.c, resolv/res_debug.c, resolv/res_init.c * resolv/inet_ntop.c, resolv/inet_pton.c: New files. * resolv/resolv.h: Add RES_USE_INET6 flag. (__dn_isvalid): Renamed to __res_dnok. Add prototypes for __res_ownok and __res_mailok. * stdio-common/Makefile: Add -Wno-unused to CFLAGS for _itoa.c. * stdio-common/getline.c, stdio-common/vfscanf.c, sysdeps/posix/tempname.c: Don't use <ansidecl.h> anymore. * sysdeps/unix/sysv/linux/Makefile [$subdir == misc] (sysdep_routines): Add s_reboot. (install-others): Add $(includedir)/sys/syscall.h. New rule for $(includedir)/sys/syscall.h to produce from <asm/unistd.h>. * sysdeps/unix/sysv/linux/reboot.c: New file. Make single argument function call 3 argument system call. * sysdeps/unix/sysv/linux/sys/reboot.h: New file. Linux specific definition for reboot function. * sysdeps/unix/sysv/linux/syscall.h: Remove old and obsolete comment. * sysdeps/unix/sysv/linux/syscalls.list: Rename function for reboot syscall to __syscall_reboot. * wcsmbs/wchar.h: Protect prototypes for wcstof and wcstold by __USE_GNU, not USE_GNU. Tue May 21 21:55:49 1996 David Mosberger-Tang <davidm@AZStarNet.com> * locale/programs/charset.c, locale/programs/ld-collate.c: Add casts to prevent warnings on 64-bit machines. * locale/programs/ld-monetary.c: Don't do unnecessary tests for int_frac_digits and frac_digits which only produce warnings. Mon May 13 23:45:29 1996 David Mosberger-Tang <davidm@AZStarNet.com> * inet/arpa/inet.h: Backup return type of inet_addr to u_long. * resolv/inet_addr.c: Likewise. * resolv/Makefile (distribute): Add res_hconf.h (routines): Add res_hconf. * resolv/gethnamaddr.c: Add support for /etc/host.conf. * resolv/res_init.c: Initialize /etc/host.conf reader. * resolv/res_hconf.c, resolv/res_hconf.h: New files. Implementation of reading /etc/host.conf. Wed May 22 21:21:15 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * Rules (%.out rules): Prepend $($*-ENV) to the command. * sysdeps/unix/sysv/linux/i386/brk.c (___brk_addr): Define as weak alias for __curbrk. Wed May 22 19:37:27 1996 Miles Bader <miles@gnu.ai.mit.edu> * hurd/hurdexec.c (_hurd_exec): Pass INIT_TRACEMASK. * hurd/hurdmsg.c (set_int): Support INIT_TRACEMASK. Wed May 22 18:47:31 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * sysdeps/mach/hurd/getcwd.c (_hurd_canonicalize_directory_name_internal): New function, broken out of __getcwd. (__getcwd): Use it. (__canonicalize_directory_name_internal): New function using it. * sysdeps/posix/getcwd.c (__canonicalize_directory_name_internal): New function, broken out of __getcwd. (__getcwd): Use it. Wed May 22 18:14:05 1996 Miles Bader <miles@gnu.ai.mit.edu> * string/argz-create.c (__argz_create): Correctly calculate length. * string/argz-extract.c (__argz_extract): Add terminating 0 entry. * hurd/hurdstartup.c (_hurd_startup): ... and don't so here. [HAVE_VMSDIR_H]: Include "vmsdir.h". (glob) [VMS]: Don't grok ~.
1996-05-23 03:15:42 +00:00
/* Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc.
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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* 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:
- new command "spoof" takes an arguments like RESOLV_SPOOF_CHECK
environment variable (i.e., `off', `nowarn', or `warn').
- line comments can appear anywhere (not just at the beginning of
a line)
*/
#include <ctype.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "res_hconf.h"
#define _PATH_HOSTCONF "/etc/host.conf"
/* Environment vars that all user to override default behavior: */
#define ENV_HOSTCONF "RESOLV_HOST_CONF"
#define ENV_SERVORDER "RESOLV_SERV_ORDER"
#define ENV_SPOOF "RESOLV_SPOOF_CHECK"
#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"
static const char * arg_service_list (const char *, int, const char *,
unsigned);
static const char * arg_trimdomain_list (const char *, int, const char *,
unsigned);
static const char * arg_spoof (const char *, int, const char *, unsigned);
static const char * arg_bool (const char *, int, const char *, unsigned);
static struct cmd {
const char * name;
const char * (*parse_args)(const char * filename, int line_num,
const char * args, unsigned arg);
unsigned arg;;
} cmd[] = {
{"order", arg_service_list, 0},
{"trim", arg_trimdomain_list, 0},
{"spoof", arg_spoof, 0},
{"multi", arg_bool, HCONF_FLAG_MULTI},
{"nospoof", arg_bool, HCONF_FLAG_SPOOF},
{"spoofalert", arg_bool, HCONF_FLAG_SPOOFALERT},
{"reorder", arg_bool, HCONF_FLAG_REORDER}
};
/*
* Why isn't this in stdlib?
*/
char *
strndup (const char * s, size_t n)
{
char * retval;
retval = malloc (n + 1);
if (!retval)
return retval;
memcpy (retval, s, n);
retval[n] = '\0'; /* ensure return value is terminated */
return retval;
}
/* 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_service_list (const char * fname, int line_num, const char * args,
unsigned arg)
{
enum Name_Service service;
const char * start;
size_t len;
int i;
static struct {
const char * name;
enum Name_Service service;
} svcs[] = {
{"bind", SERVICE_BIND},
{"hosts", SERVICE_HOSTS},
{"nis", SERVICE_NIS},
};
do
{
start = args;
args = skip_string (args);
len = args - start;
service = SERVICE_NONE;
for (i = 0; i < sizeof (svcs) / sizeof (svcs[0]); ++i)
{
if (strncasecmp (start, svcs[i].name, len) == 0
&& len == strlen (svcs[i].name))
{
service = svcs[i].service;
break;
}
}
if (service == SERVICE_NONE)
{
fprintf (stderr, "%s: line %d: expected service, found `%s'\n",
fname, line_num, start);
return 0;
}
if (_res_hconf.num_services >= SERVICE_MAX)
{
fprintf (stderr, "%s: line %d: cannot specify more than %d services",
fname, line_num, SERVICE_MAX);
return 0;
}
_res_hconf.service[_res_hconf.num_services++] = service;
args = skip_ws (args);
switch (*args)
{
case ',': case ';': case ':':
args = skip_ws (++args);
if (!*args || *args == '#')
{
fprintf (stderr,
"%s: line %d: list delimiter not followed by keyword",
fname, line_num);
return 0;
}
default:
break;
}
}
while (*args && *args != '#');
return args;
}
static const char *
arg_trimdomain_list (const char * fname, int line_num, const char * args,
unsigned flag)
{
const char * start;
size_t len;
do
{
start = args;
args = skip_string (args);
len = args - start;
if (_res_hconf.num_trimdomains >= TRIMDOMAINS_MAX)
{
fprintf (stderr,
"%s: line %d: cannot specify more than %d trim domains",
fname, line_num, TRIMDOMAINS_MAX);
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 == '#')
{
fprintf (stderr,
"%s: line %d: list delimiter not followed by domain",
fname, line_num);
return 0;
}
default:
break;
}
}
while (*args && *args != '#');
return args;
}
static const char *
arg_spoof (const char * fname, int line_num, const char * args, unsigned flag)
{
const char * start = args;
size_t len;
args = skip_string (args);
len = args - start;
if (len == 3 && strncasecmp (start, "off", len) == 0)
_res_hconf.flags &= ~(HCONF_FLAG_SPOOF | HCONF_FLAG_SPOOFALERT);
else
{
_res_hconf.flags |= (HCONF_FLAG_SPOOF | HCONF_FLAG_SPOOFALERT);
if ((len == 6 && strncasecmp (start, "nowarn", len) == 0)
|| !(len == 4 && strncasecmp (start, "warn", len) == 0))
_res_hconf.flags &= ~HCONF_FLAG_SPOOFALERT;
}
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
{
fprintf (stderr, "%s: line %d: expected `on' or `off', found `%s'\n",
fname, line_num, args);
return 0;
}
return args;
}
static void
parse_line (const char * fname, int line_num, const char * str)
{
const char * start;
struct cmd * c = 0;
size_t len;
int i;
str = skip_ws (str);
if (*str == '#') return; /* skip line comment */
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)
{
fprintf (stderr, "%s: line %d: bad command `%s'\n",
fname, line_num, start);
return;
}
/* process args: */
str = skip_ws (str);
str = (*c->parse_args) (fname, line_num, str, c->arg);
if (!str)
return;
/* rest of line must contain white space or comment only: */
while (*str)
{
if (!isspace (*str)) {
if (*str != '#')
fprintf (stderr, "%s: line %d: ignoring trailing garbage `%s'\n",
fname, line_num, str);
break;
}
++str;
}
}
/* Initialize hconf datastructure by reading host.conf file and
environment variables. */
void
_res_hconf_init (void)
{
const char * hconf_name;
int line_num = 0;
char buf[256], * end, * envval;
FILE * fp;
memset (&_res_hconf, 0, sizeof (_res_hconf));
hconf_name = getenv (ENV_HOSTCONF);
if (!hconf_name)
hconf_name = _PATH_HOSTCONF;
fp = fopen (hconf_name, "r");
if (!fp)
/* make up something reasonable: */
_res_hconf.service[_res_hconf.num_services++] = SERVICE_BIND;
else
{
while (fgets (buf, sizeof (buf), fp))
{
++line_num;
end = strchr (buf, '\n');
if (end)
*end = '\0';
parse_line (hconf_name, line_num, buf);
}
fclose (fp);
}
envval = getenv (ENV_SERVORDER);
if (envval)
{
_res_hconf.num_services = 0;
arg_service_list (ENV_SERVORDER, 1, envval, 0);
}
envval = getenv (ENV_SPOOF);
if (envval)
arg_spoof (ENV_SPOOF, 1, envval, 0);
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, 0);
envval = getenv (ENV_TRIM_OVERR);
if (envval)
{
_res_hconf.num_trimdomains = 0;
arg_trimdomain_list (ENV_TRIM_OVERR, 1, envval, 0);
}
}
/* 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. */
void
_res_hconf_reorder_addrs (struct hostent * hp)
{
#if defined (SIOCGIFCONF) && defined (SIOCGIFNETMASK)
static int num_ifs = -1; /* number of interfaces */
static struct netaddr {
int addrtype;
union {
struct {
u_int32_t addr;
u_int32_t mask;
} ipv4
} u;
} * ifaddrs;
if (hp->h_addrtype != AF_INET)
return; /* can't deal with anything but IPv4 for now... */
if (num_ifs <= 0)
{
struct ifconf ifs;
struct ifreq * ifr;
size_t size, num;
int sd;
/* initialize interface table: */
num_ifs = 0;
sd = socket (AF_INET, SOCK_DGRAM, 0);
if (sd < 0)
return;
/* Now get list of interfaces. Since we don't know how many
interfaces there are, we keep increasing the buffer size
until we have at least sizeof(struct ifreq) too many bytes.
That implies that the ioctl() return because it ran out of
interfaces, not memory */
size = 0;
ifs.ifc_buf = 0;
do {
size += 4 * sizeof (struct ifreq);
ifs.ifc_buf = realloc (ifs.ifs_buf, size);
if (!ifs.ifc_buf)
{
close (sd);
return;
}
ifs.ifc_len = size;
if (ioctl (sd, SIOCGIFCONF, &ifs) < 0)
goto cleanup;
} while (size - ifs.ifc_len < sizeof (struct ifreq));
num = ifs.ifc_len / sizeof (struct ifreq);
ifaddrs = malloc (num * sizeof (ifaddrs[0]));
if (!ifaddrs)
goto cleanup;
ifr = ifs.ifc_req;
for (i = 0; i < num; ++i) {
if (ifr->ifr_addr.sa_family != AF_INET)
continue;
ifaddrs[num_ifs].addrtype = AF_INET;
memcpy (&ifaddrs[num_ifs].u.ipv4.addr,
&((struct sockaddr_in *)ifr->ifr_addr)->sin_addr, 4);
if (ioctl (sd, SIOCGIFNETMASK, if) < 0)
continue;
memcpy (&ifaddrs[num_ifs].u.ipv4.mask,
((struct sockaddr_in *)ifr->ifr_mask)->sin_addr, 4);
++num_ifs; /* now we're committed to this entry */
}
/* just keep enough memory to hold all the interfaces we want: */
ifaddrs = realloc (ifaddrs, num_ifs * sizeof (ifaddrs[0]));
cleanup:
close (sd);
free (ifs.ifc_buf);
}
if (num_ifs == 0)
return;
/* find an address for which we have a direct connection: */
for (i = 0; hp->h_addr_list[i]; ++i)
{
h_addr = (struct in_addr *) hp->h_addr_list[i];
for (j = 0; j < num_ifs; ++j)
{
if_addr = ifaddrs[j].u.ipv4.addr;
if_netmask = ifaddrs[j].u.ipv4.mask;
if (((h_addr->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]);
}
#if 0
struct hostent *
_hconf_gethostent (void)
{
}
struct hostent *
_hconf_gethostbyname (const char * name)
{
}
struct hostent *
_hconf_gethostbyaddr (const char * addr, int len, int type)
{
}
struct hostent *
_hconf_gethtbyname (const char * name)
{
}
#endif