From fa0bc87c32d02cd81ec4d0ae00e0d943c683e6e1 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 23 May 1996 03:15:42 +0000 Subject: Wed May 22 22:10:01 1996 Roland McGrath * 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 * 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 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 . 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 . * 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 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 . * 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 * 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 * 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 * 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 * 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 * 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 * 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 ~. --- resolv/res_hconf.c | 566 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 566 insertions(+) create mode 100644 resolv/res_hconf.c (limited to 'resolv/res_hconf.c') diff --git a/resolv/res_hconf.c b/resolv/res_hconf.c new file mode 100644 index 0000000000..b08dd3ced7 --- /dev/null +++ b/resolv/res_hconf.c @@ -0,0 +1,566 @@ +/* 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 +#include +#include +#include +#include + +#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 -- cgit v1.2.3