Logo Search packages:      
Sourcecode: samhain version File versions  Download package

sh_static.c

/*  Copyright (C) 2003     Manuel Novoa III
 *
 *  This 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.
 *
 *  This 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 this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*  Nov 6, 2003  Initial version.
 *
 *  NOTE: This implementation is quite strict about requiring all
 *    field seperators.  It also does not allow leading whitespace
 *    except when processing the numeric fields.  glibc is more
 *    lenient.  See the various glibc difference comments below.
 *
 *  TODO:
 *    Move to dynamic allocation of (currently staticly allocated)
 *      buffers; especially for the group-related functions since
 *      large group member lists will cause error returns.
 *
 */

/* Jul 20, 2004 Adapted for samhain. Rainer Wichmann.
 *
 *   Stripped all unneeded code.
 */

#include "config_xor.h"

#if defined(SH_COMPILE_STATIC) && defined(__linux__)

#define _GNU_SOURCE
#include <features.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stddef.h>
#include <errno.h>
#include <assert.h>
#include <ctype.h>
#include <pwd.h>
#include <grp.h>

#ifndef _PATH_PASSWD
#define _PATH_PASSWD "/etc/passwd"
#endif
#ifndef _PATH_GROUP
#define _PATH_GROUP "/etc/group"
#endif



/**********************************************************************/
/* Sizes for staticly allocated buffers. */

#define PWD_BUFFER_SIZE 256
#define GRP_BUFFER_SIZE 256

/**********************************************************************/
/* Prototypes for internal functions. */

static int __parsepwent(void *pw, char *line);
static int __parsegrent(void *gr, char *line);

static int __pgsreader(int (*__parserfunc)(void *d, char *line), void *data,
                   char *__restrict line_buff, 
                   size_t buflen, FILE *f);

#undef  GETXXKEY_R_FUNC 
#undef  GETXXKEY_R_PARSER
#undef  GETXXKEY_R_ENTTYPE
#undef  GETXXKEY_R_TEST
#undef  DO_GETXXKEY_R_KEYTYPE
#undef  DO_GETXXKEY_R_PATHNAME
#define GETXXKEY_R_FUNC             sh_getpwnam_r
#define GETXXKEY_R_PARSER     __parsepwent
#define GETXXKEY_R_ENTTYPE          struct passwd
#define GETXXKEY_R_TEST(ENT)  (!strcmp((ENT)->pw_name, key))
#define DO_GETXXKEY_R_KEYTYPE const char *__restrict
#define DO_GETXXKEY_R_PATHNAME  _PATH_PASSWD

static int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
                     GETXXKEY_R_ENTTYPE *__restrict resultbuf,
                     char *__restrict buffer, size_t buflen,
                     GETXXKEY_R_ENTTYPE **__restrict result)
{
  FILE *stream;
  int rv;
  
  *result = NULL;
  
  if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
    rv = errno;
  } else {
    /* __STDIO_SET_USER_LOCKING(stream); */
    do {
      if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
                       buffer, buflen, stream))
        ) {
      if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
        *result = resultbuf;
        break;
      }
      } else {
      if (rv == ENOENT) {     /* end-of-file encountered. */
        rv = 0;
      }
      break;
      }
    } while (1);
    fclose(stream);
  }
  
  return rv;
}

#undef  GETXXKEY_R_FUNC 
#undef  GETXXKEY_R_PARSER
#undef  GETXXKEY_R_ENTTYPE
#undef  GETXXKEY_R_TEST
#undef  DO_GETXXKEY_R_KEYTYPE
#undef  DO_GETXXKEY_R_PATHNAME
#define GETXXKEY_R_FUNC             sh_getgrnam_r
#define GETXXKEY_R_PARSER     __parsegrent
#define GETXXKEY_R_ENTTYPE          struct group
#define GETXXKEY_R_TEST(ENT)  (!strcmp((ENT)->gr_name, key))
#define DO_GETXXKEY_R_KEYTYPE const char *__restrict
#define DO_GETXXKEY_R_PATHNAME  _PATH_GROUP

static int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
                     GETXXKEY_R_ENTTYPE *__restrict resultbuf,
                     char *__restrict buffer, size_t buflen,
                     GETXXKEY_R_ENTTYPE **__restrict result)
{
  FILE *stream;
  int rv;
  
  *result = NULL;
  
  if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
    rv = errno;
  } else {
    /* __STDIO_SET_USER_LOCKING(stream); */
    do {
      if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
                       buffer, buflen, stream))
        ) {
      if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
        *result = resultbuf;
        break;
      }
      } else {
      if (rv == ENOENT) {     /* end-of-file encountered. */
        rv = 0;
      }
      break;
      }
    } while (1);
    fclose(stream);
  }
  
  return rv;
}

#undef  GETXXKEY_R_FUNC 
#undef  GETXXKEY_R_PARSER
#undef  GETXXKEY_R_ENTTYPE
#undef  GETXXKEY_R_TEST
#undef  DO_GETXXKEY_R_KEYTYPE
#undef  DO_GETXXKEY_R_PATHNAME
#define GETXXKEY_R_FUNC             sh_getpwuid_r
#define GETXXKEY_R_PARSER     __parsepwent
#define GETXXKEY_R_ENTTYPE          struct passwd
#define GETXXKEY_R_TEST(ENT)  ((ENT)->pw_uid == key)
#define DO_GETXXKEY_R_KEYTYPE uid_t
#define DO_GETXXKEY_R_PATHNAME  _PATH_PASSWD

static int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
                     GETXXKEY_R_ENTTYPE *__restrict resultbuf,
                     char *__restrict buffer, size_t buflen,
                     GETXXKEY_R_ENTTYPE **__restrict result)
{
  FILE *stream;
  int rv;
  
  *result = NULL;
  
  if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
    rv = errno;
  } else {
    /* __STDIO_SET_USER_LOCKING(stream); */
    do {
      if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
                       buffer, buflen, stream))
        ) {
      if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
        *result = resultbuf;
        break;
      }
      } else {
      if (rv == ENOENT) {     /* end-of-file encountered. */
        rv = 0;
      }
      break;
      }
    } while (1);
    fclose(stream);
  }
  
  return rv;
}

#undef  GETXXKEY_R_FUNC 
#undef  GETXXKEY_R_PARSER
#undef  GETXXKEY_R_ENTTYPE
#undef  GETXXKEY_R_TEST
#undef  DO_GETXXKEY_R_KEYTYPE
#undef  DO_GETXXKEY_R_PATHNAME
#define GETXXKEY_R_FUNC             sh_getgrgid_r
#define GETXXKEY_R_PARSER     __parsegrent
#define GETXXKEY_R_ENTTYPE          struct group
#define GETXXKEY_R_TEST(ENT)  ((ENT)->gr_gid == key)
#define DO_GETXXKEY_R_KEYTYPE gid_t
#define DO_GETXXKEY_R_PATHNAME  _PATH_GROUP

static int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
                     GETXXKEY_R_ENTTYPE *__restrict resultbuf,
                     char *__restrict buffer, size_t buflen,
                     GETXXKEY_R_ENTTYPE **__restrict result)
{
  FILE *stream;
  int rv;
  
  *result = NULL;
  
  if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
    rv = errno;
  } else {
    /* __STDIO_SET_USER_LOCKING(stream); */
    do {
      if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
                       buffer, buflen, stream))
        ) {
      if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
        *result = resultbuf;
        break;
      }
      } else {
      if (rv == ENOENT) {     /* end-of-file encountered. */
        rv = 0;
      }
      break;
      }
    } while (1);
    fclose(stream);
  }
  
  return rv;
}

struct passwd * sh_getpwuid(uid_t uid)
{
      static char buffer[PWD_BUFFER_SIZE];
      static struct passwd resultbuf;
      struct passwd *result;

      sh_getpwuid_r(uid, &resultbuf, buffer, sizeof(buffer), &result);
      return result;
}

struct group * sh_getgrgid(gid_t gid)
{
      static char buffer[GRP_BUFFER_SIZE];
      static struct group resultbuf;
      struct group *result;

      sh_getgrgid_r(gid, &resultbuf, buffer, sizeof(buffer), &result);
      return result;
}


struct passwd * sh_getpwnam(const char *name)
{
      static char buffer[PWD_BUFFER_SIZE];
      static struct passwd resultbuf;
      struct passwd *result;

      sh_getpwnam_r(name, &resultbuf, buffer, sizeof(buffer), &result);
      return result;
}

struct group * sh_getgrnam(const char *name)
{
      static char buffer[GRP_BUFFER_SIZE];
      static struct group resultbuf;
      struct group *result;

      sh_getgrnam_r(name, &resultbuf, buffer, sizeof(buffer), &result);
      return result;
}

#define LOCK            ((void) 0)
#define UNLOCK          ((void) 0)

static FILE *pwf = NULL;

void  sh_setpwent(void)
{
      LOCK;
      if (pwf) {
            rewind(pwf);
      }
      UNLOCK;
}

void  sh_endpwent(void)
{
      LOCK;
      if (pwf) {
            fclose(pwf);
            pwf = NULL;
      }
      UNLOCK;
}


static int  sh_getpwent_r(struct passwd *__restrict resultbuf, 
                    char *__restrict buffer, size_t buflen,
                    struct passwd **__restrict result)
{
      int rv;

      LOCK;

      *result = NULL;                     /* In case of error... */

      if (!pwf) {
            if (!(pwf = fopen(_PATH_PASSWD, "r"))) {
                  rv = errno;
                  goto ERR;
            }
            /* __STDIO_SET_USER_LOCKING(pwf); */
      }

      if (!(rv = __pgsreader(__parsepwent, resultbuf,
                                       buffer, buflen, pwf))) {
            *result = resultbuf;
      }

 ERR:
      UNLOCK;

      return rv;
}

#define LOCK            ((void) 0)
#define UNLOCK          ((void) 0)

static FILE *grf = NULL;

void  sh_setgrent(void)
{
      LOCK;
      if (grf) {
            rewind(grf);
      }
      UNLOCK;
}

void  sh_endgrent(void)
{
      LOCK;
      if (grf) {
            fclose(grf);
            grf = NULL;
      }
      UNLOCK;
}

static int sh_getgrent_r(struct group *__restrict resultbuf,
                   char *__restrict buffer, size_t buflen,
                   struct group **__restrict result)
{
      int rv;

      LOCK;

      *result = NULL;                     /* In case of error... */

      if (!grf) {
            if (!(grf = fopen(_PATH_GROUP, "r"))) {
                  rv = errno;
                  goto ERR;
            }
            /* __STDIO_SET_USER_LOCKING(grf); */
      }

      if (!(rv = __pgsreader(__parsegrent, resultbuf,
                                       buffer, buflen, grf))) {
            *result = resultbuf;
      }

 ERR:
      UNLOCK;

      return rv;
}


struct passwd * sh_getpwent(void)
{
      static char line_buff[PWD_BUFFER_SIZE];
      static struct passwd pwd;
      struct passwd *result;

      sh_getpwent_r(&pwd, line_buff, sizeof(line_buff), &result);
      return result;
}


struct group * sh_getgrent(void)
{
      static char line_buff[GRP_BUFFER_SIZE];
      static struct group gr;
      struct group *result;

       sh_getgrent_r(&gr, line_buff, sizeof(line_buff), &result);
      return result;
}

int  sh_initgroups(const char *user, gid_t gid)
{
      FILE *grf;
      gid_t *group_list;
      int num_groups, rv;
      char **m;
      struct group group;
      char buff[PWD_BUFFER_SIZE];

      rv = -1;

      /* We alloc space for 8 gids at a time. */
      if (((group_list = (gid_t *) malloc(8*sizeof(gid_t *))) != NULL)
            && ((grf = fopen(_PATH_GROUP, "r")) != NULL)
            ) {

        /* __STDIO_SET_USER_LOCKING(grf); */

            *group_list = gid;
            num_groups = 1;

            while (!__pgsreader(__parsegrent, &group, buff, sizeof(buff), grf)) {
                  assert(group.gr_mem); /* Must have at least a NULL terminator. */
                  if (group.gr_gid != gid) {
                        for (m=group.gr_mem ; *m ; m++) {
                              if (!strcmp(*m, user)) {
                                    if (!(num_groups & 7)) {
                                          gid_t *tmp = (gid_t *)
                                                realloc(group_list,
                                                            (num_groups+8) * sizeof(gid_t *));
                                          if (!tmp) {
                                                rv = -1;
                                                goto DO_CLOSE;
                                          }
                                          group_list = tmp;
                                    }
                                    group_list[num_groups++] = group.gr_gid;
                                    break;
                              }
                        }
                  }
            }

            rv = setgroups(num_groups, group_list);
      DO_CLOSE:
            fclose(grf);
      }

      /* group_list will be NULL if initial malloc failed, which may trigger
       * warnings from various malloc debuggers. */
      free(group_list);
      return rv;
}


/**********************************************************************/
/* Internal uClibc functions.                                         */
/**********************************************************************/

static const unsigned char pw_off[] = {
      offsetof(struct passwd, pw_name),   /* 0 */
      offsetof(struct passwd, pw_passwd), /* 1 */
      offsetof(struct passwd, pw_uid),    /* 2 - not a char ptr */
      offsetof(struct passwd, pw_gid),    /* 3 - not a char ptr */
      offsetof(struct passwd, pw_gecos),  /* 4 */
      offsetof(struct passwd, pw_dir),    /* 5 */
      offsetof(struct passwd, pw_shell)   /* 6 */
};

static int __parsepwent(void *data, char *line)
{
      char *endptr;
      char *p;
      int i;

      i = 0;
      do {
            p = ((char *) ((struct passwd *) data)) + pw_off[i];

            if ((i & 6) ^ 2) {      /* i!=2 and i!=3 */
                  *((char **) p) = line;
                  if (i==6) {
                        return 0;
                  }
                  /* NOTE: glibc difference - glibc allows omission of
                   * ':' seperators after the gid field if all remaining
                   * entries are empty.  We require all separators. */
                  if (!(line = strchr(line, ':'))) {
                        break;
                  }
            } else {
                  unsigned long t = strtoul(line, &endptr, 10);
                  /* Make sure we had at least one digit, and that the
                   * failing char is the next field seperator ':'.  See
                   * glibc difference note above. */
                  /* TODO: Also check for leading whitespace? */
                  if ((endptr == line) || (*endptr != ':')) {
                        break;
                  }
                  line = endptr;
                  if (i & 1) {            /* i == 3 -- gid */
                        *((gid_t *) p) = t;
                  } else {                /* i == 2 -- uid */
                        *((uid_t *) p) = t;
                  }
            }

            *line++ = 0;
            ++i;
      } while (1);

      return -1;
}

static const unsigned char gr_off[] = {
      offsetof(struct group, gr_name),    /* 0 */
      offsetof(struct group, gr_passwd),  /* 1 */
      offsetof(struct group, gr_gid)            /* 2 - not a char ptr */
};

static int __parsegrent(void *data, char *line)
{
      char *endptr;
      char *p;
      int i;
      char **members;
      char *end_of_buf;

      end_of_buf = ((struct group *) data)->gr_name; /* Evil hack! */
      i = 0;
      do {
            p = ((char *) ((struct group *) data)) + gr_off[i];

            if (i < 2) {
                  *((char **) p) = line;
                  if (!(line = strchr(line, ':'))) {
                        break;
                  }
                  *line++ = 0;
                  ++i;
            } else {
                  *((gid_t *) p) = strtoul(line, &endptr, 10);

                  /* NOTE: glibc difference - glibc allows omission of the
                   * trailing colon when there is no member list.  We treat
                   * this as an error. */

                  /* Make sure we had at least one digit, and that the
                   * failing char is the next field seperator ':'.  See
                   * glibc difference note above. */
                  if ((endptr == line) || (*endptr != ':')) {
                        break;
                  }

                  i = 1;                        /* Count terminating NULL ptr. */
                  p = endptr;

                  if (p[1]) { /* We have a member list to process. */
                        /* Overwrite the last ':' with a ',' before counting.
                         * This allows us to test for initial ',' and adds
                         * one ',' so that the ',' count equals the member
                         * count. */
                        *p = ',';
                        do {
                              /* NOTE: glibc difference - glibc allows and trims leading
                               * (but not trailing) space.  We treat this as an error. */
                              /* NOTE: glibc difference - glibc allows consecutive and
                               * trailing commas, and ignores "empty string" users.  We
                               * treat this as an error. */
                              if (*p == ',') {
                                    ++i;
                                    *p = 0;     /* nul-terminate each member string. */
                                    if (!*++p || (*p == ',') || isspace(*p)) {
                                          goto ERR;
                                    }
                              }
                        } while (*++p);
                  }

                  /* Now align (p+1), rounding up. */
                  /* Assumes sizeof(char **) is a power of 2. */
                  members = (char **)( (((intptr_t) p) + sizeof(char **))
                                                 & ~((intptr_t)(sizeof(char **) - 1)) );

                  if (((char *)(members + i)) > end_of_buf) {     /* No space. */
                        break;
                  }

                  ((struct group *) data)->gr_mem = members;

                  if (--i) {
                        p = endptr; /* Pointing to char prior to first member. */
                        do {
                              *members++ = ++p;
                              if (!--i) break;
                              while (*++p) {}
                        } while (1);
                  }                       
                  *members = NULL;

                  return 0;
            }
      } while (1);

 ERR:
      return -1;
}

/* Reads until if EOF, or until if finds a line which fits in the buffer
 * and for which the parser function succeeds.
 *
 * Returns 0 on success and ENOENT for end-of-file (glibc concession).
 */

static int __pgsreader(int (*__parserfunc)(void *d, char *line), void *data,
                   char *__restrict line_buff, size_t buflen, FILE *f)
{
        size_t line_len; /* int -> size_t R.W. */
      int skip;
      int rv = ERANGE;

      if (buflen < PWD_BUFFER_SIZE) {
              errno = rv;
      } else {
        /* __STDIO_THREADLOCK(f); */

            skip = 0;
            do {
                  if (!fgets_unlocked(line_buff, buflen, f)) {
                        if (feof_unlocked(f)) {
                              rv = ENOENT;
                        }
                        break;
                  }

                  line_len = strlen(line_buff) - 1; /* strlen() must be > 0. */
                  if (line_buff[line_len] == '\n') {
                        line_buff[line_len] = 0;
                  } else if (line_len + 2 == buflen) { /* line too long */
                        ++skip;
                        continue;
                  }

                  if (skip) {
                        --skip;
                        continue;
                  }

                  /* NOTE: glibc difference - glibc strips leading whitespace from
                   * records.  We do not allow leading whitespace. */

                  /* Skip empty lines, comment lines, and lines with leading
                   * whitespace. */
                  if (*line_buff && (*line_buff != '#') && !isspace(*line_buff)) {
                        if (__parserfunc == __parsegrent) { /* Do evil group hack. */
                              /* The group entry parsing function needs to know where
                               * the end of the buffer is so that it can construct the
                               * group member ptr table. */
                              ((struct group *) data)->gr_name = line_buff + buflen;
                        }

                        if (!__parserfunc(data, line_buff)) {
                              rv = 0;
                              break;
                        }
                  }
            } while (1);

            /* __STDIO_THREADUNLOCK(f); */
      }

      return rv;
}

/* resolv.c: DNS Resolver
 *
 * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
 *                     The Silver Hammer Group, Ltd.
 *
 * This 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.
*/

/*
 * Portions Copyright (c) 1985, 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.
 */

/*
 *
 *  5-Oct-2000 W. Greathouse  wgreathouse@smva.com
 *                              Fix memory leak and memory corruption.
 *                              -- Every name resolution resulted in
 *                                 a new parse of resolv.conf and new
 *                                 copy of nameservers allocated by
 *                                 strdup.
 *                              -- Every name resolution resulted in
 *                                 a new read of resolv.conf without
 *                                 resetting index from prior read...
 *                                 resulting in exceeding array bounds.
 *
 *                              Limit nameservers read from resolv.conf
 *
 *                              Add "search" domains from resolv.conf
 *
 *                              Some systems will return a security
 *                              signature along with query answer for
 *                              dynamic DNS entries.
 *                              -- skip/ignore this answer
 *
 *                              Include arpa/nameser.h for defines.
 *
 *                              General cleanup
 *
 * 20-Jun-2001 Michal Moskal <malekith@pld.org.pl>
 *   partial IPv6 support (i.e. gethostbyname2() and resolve_address2()
 *   functions added), IPv6 nameservers are also supported.
 *
 * 6-Oct-2001 Jari Korva <jari.korva@iki.fi>
 *   more IPv6 support (IPv6 support for gethostbyaddr();
 *   address family parameter and improved IPv6 support for get_hosts_byname
 *   and read_etc_hosts; getnameinfo() port from glibc; defined
 *   defined ip6addr_any and in6addr_loopback)
 *
 * 2-Feb-2002 Erik Andersen <andersee@debian.org>
 * Added gethostent(), sethostent(), and endhostent()
 *
 * 17-Aug-2002 Manuel Novoa III <mjn3@codepoet.org>
 *   Fixed __read_etc_hosts_r to return alias list, and modified buffer
 *   allocation accordingly.  See MAX_ALIASES and ALIAS_DIM below.
 *   This fixes the segfault in the Python 2.2.1 socket test.
 *
 * 04-Jan-2003 Jay Kulpinski <jskulpin@berkshire.rr.com>
 *   Fixed __decode_dotted to count the terminating null character
 *   in a host name.
 *
 * 02-Oct-2003 Tony J. White <tjw@tjw.org>
 *   Lifted dn_expand() and dependent ns_name_uncompress(), ns_name_unpack(),
 *   and ns_name_ntop() from glibc 2.3.2 for compatibility with ipsec-tools 
 *   and openldap.
 *
 */

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

/* close()
 */
#include <unistd.h>

/* 'struct hostent'
 */
#include <netdb.h>

/* constanst like HFIXEDSZ
 */
#include <arpa/nameser.h>

#define BIGLOCK
#define BIGUNLOCK

#define __UCLIBC_HAS_IPV6__
#define MAX_RECURSE 5
#define REPLY_TIMEOUT 10
#define MAX_RETRIES 3
#define MAX_SERVERS 3
#define MAX_SEARCH 4
#define MAX_ALIASES     5

/* 1:ip + 1:full + MAX_ALIASES:aliases + 1:NULL */
#define     ALIAS_DIM         (2 + MAX_ALIASES + 1)

static int __nameservers;
static char * __nameserver[MAX_SERVERS];
static int __searchdomains;
static char * __searchdomain[MAX_SEARCH];

#undef DEBUG
/*#define DEBUG*/

#ifdef DEBUG
#define DPRINTF(X,args...) fprintf(stderr, X, ##args)
#else
#define DPRINTF(X,args...)
#endif /* DEBUG */

struct resolv_header {
      int id;
      int qr,opcode,aa,tc,rd,ra,rcode;
      int qdcount;
      int ancount;
      int nscount;
      int arcount;
};

struct resolv_question {
      char * dotted;
      int qtype;
      int qclass;
};

struct resolv_answer {
      char * dotted;
      int atype;
      int aclass;
      int ttl;
      int rdlength;
      unsigned char * rdata;
      int rdoffset;
};

enum etc_hosts_action {
    GET_HOSTS_BYNAME = 0,
    GETHOSTENT,
    GET_HOSTS_BYADDR,
};

static int __encode_header(struct resolv_header *h, unsigned char *dest, int maxlen)
{
      if (maxlen < HFIXEDSZ)
            return -1;

      dest[0] = (h->id & 0xff00) >> 8;
      dest[1] = (h->id & 0x00ff) >> 0;
      dest[2] = (h->qr ? 0x80 : 0) |
            ((h->opcode & 0x0f) << 3) |
            (h->aa ? 0x04 : 0) | 
            (h->tc ? 0x02 : 0) | 
            (h->rd ? 0x01 : 0);
      dest[3] = (h->ra ? 0x80 : 0) | (h->rcode & 0x0f);
      dest[4] = (h->qdcount & 0xff00) >> 8;
      dest[5] = (h->qdcount & 0x00ff) >> 0;
      dest[6] = (h->ancount & 0xff00) >> 8;
      dest[7] = (h->ancount & 0x00ff) >> 0;
      dest[8] = (h->nscount & 0xff00) >> 8;
      dest[9] = (h->nscount & 0x00ff) >> 0;
      dest[10] = (h->arcount & 0xff00) >> 8;
      dest[11] = (h->arcount & 0x00ff) >> 0;

      return HFIXEDSZ;
}

static int __decode_header(unsigned char *data, struct resolv_header *h)
{
      h->id = (data[0] << 8) | data[1];
      h->qr = (data[2] & 0x80) ? 1 : 0;
      h->opcode = (data[2] >> 3) & 0x0f;
      h->aa = (data[2] & 0x04) ? 1 : 0;
      h->tc = (data[2] & 0x02) ? 1 : 0;
      h->rd = (data[2] & 0x01) ? 1 : 0;
      h->ra = (data[3] & 0x80) ? 1 : 0;
      h->rcode = data[3] & 0x0f;
      h->qdcount = (data[4] << 8) | data[5];
      h->ancount = (data[6] << 8) | data[7];
      h->nscount = (data[8] << 8) | data[9];
      h->arcount = (data[10] << 8) | data[11];

      return HFIXEDSZ;
}

static int __length_dotted(const unsigned char *data, int offset)
{
      int orig_offset = offset;
      int l;

      if (!data)
            return -1;

      while ((l = data[offset++])) {

            if ((l & 0xc0) == (0xc0)) {
                  offset++;
                  break;
            }

            offset += l;
      }

      return offset - orig_offset;
}

static int __length_question(unsigned char *message, int offset)
{
      int i;

      i = __length_dotted(message, offset);
      if (i < 0)
            return i;

      return i + 4;
}

/* Decode a dotted string from nameserver transport-level encoding.
   This routine understands compressed data. */

static int __decode_dotted(const unsigned char *data, int offset,
                          char *dest, int maxlen)
{
      int l;
      int measure = 1;
      int total = 0;
      int used = 0;

      if (!data)
            return -1;

      while ((l=data[offset++])) {
            if (measure)
                total++;
            if ((l & 0xc0) == (0xc0)) {
                  if (measure)
                        total++;
                  /* compressed item, redirect */
                  offset = ((l & 0x3f) << 8) | data[offset];
                  measure = 0;
                  continue;
            }

            if ((used + l + 1) >= maxlen)
                  return -1;

            memcpy(dest + used, data + offset, l);
            offset += l;
            used += l;
            if (measure)
                  total += l;

            if (data[offset] != 0)
                  dest[used++] = '.';
            else
                  dest[used++] = '\0';
      }

      /* The null byte must be counted too */
      if (measure) {
          total++;
      }

      DPRINTF("Total decode len = %d\n", total);

      return total;
}

static int __decode_answer(unsigned char *message, int offset,
                          struct resolv_answer *a)
{
      char temp[256];
      int i;

      i = __decode_dotted(message, offset, temp, sizeof(temp));
      if (i < 0)
            return i;

      message += offset + i;

      a->dotted = strdup(temp);
      a->atype = (message[0] << 8) | message[1];
      message += 2;
      a->aclass = (message[0] << 8) | message[1];
      message += 2;
      a->ttl = (message[0] << 24) |
            (message[1] << 16) | (message[2] << 8) | (message[3] << 0);
      message += 4;
      a->rdlength = (message[0] << 8) | message[1];
      message += 2;
      a->rdata = message;
      a->rdoffset = offset + i + RRFIXEDSZ;

      DPRINTF("i=%d,rdlength=%d\n", i, a->rdlength);

      return i + RRFIXEDSZ + a->rdlength;
}


/* Encode a dotted string into nameserver transport-level encoding.
   This routine is fairly dumb, and doesn't attempt to compress
   the data */

static int __encode_dotted(const char *dotted, unsigned char *dest, int maxlen)
{
      unsigned int used = 0;

      while (dotted && *dotted) {
            char *c = strchr(dotted, '.');
            unsigned int l = c ? (unsigned int)(c - dotted) : strlen(dotted);

            if (l >= ((unsigned int)maxlen - used - 1))
                  return -1;

            dest[used++] = l;
            memcpy(dest + used, dotted, l);
            used += l;

            if (c)
                  dotted = c + 1;
            else
                  break;
      }

      if (maxlen < 1)
            return -1;

      dest[used++] = 0;

      return used;
}

static int __encode_question(struct resolv_question *q,
                              unsigned char *dest, int maxlen)
{
      int i;

      i = __encode_dotted(q->dotted, dest, maxlen);
      if (i < 0)
            return i;

      dest += i;
      maxlen -= i;

      if (maxlen < 4)
            return -1;

      dest[0] = (q->qtype & 0xff00) >> 8;
      dest[1] = (q->qtype & 0x00ff) >> 0;
      dest[2] = (q->qclass & 0xff00) >> 8;
      dest[3] = (q->qclass & 0x00ff) >> 0;

      return i + 4;
}


/* Just for the record, having to lock __dns_lookup() just for these two globals
 * is pretty lame.  I think these two variables can probably be de-global-ized, 
 * which should eliminate the need for doing locking here...  Needs a closer 
 * look anyways. */
static int ns=0, id=1;

static int __dns_lookup(const char *name, int type, int nscount, char **nsip,
                     unsigned char **outpacket, struct resolv_answer *a)
{
      int i, j, len, fd, pos, rc;
      struct timeval tv;
      fd_set fds;
      struct resolv_header h;
      struct resolv_question q;
      int retries = 0;
      unsigned char * packet = malloc(PACKETSZ);
      char *dns, *lookup = malloc(MAXDNAME);
      int variant = 0;
      struct sockaddr_in sa;
#ifdef __UCLIBC_HAS_IPV6__
      int v6;
      struct sockaddr_in6 sa6;
#endif

      fd = -1;

      if (!packet || !lookup || !nscount)
          goto fail;

      DPRINTF("Looking up type %d answer for '%s'\n", type, name);

      LOCK;
      ns %= nscount;
      UNLOCK;

      while (retries++ < MAX_RETRIES) {
            if (fd != -1)
                  close(fd);

            memset(packet, 0, PACKETSZ);

            memset(&h, 0, sizeof(h));

            /* Mess with globals while under lock */
            LOCK;
            ++id;
            id &= 0xffff;
            h.id = id;
            dns = nsip[ns];
            UNLOCK;

            h.qdcount = 1;
            h.rd = 1;

            DPRINTF("encoding header\n", h.rd);

            i = __encode_header(&h, packet, PACKETSZ);
            if (i < 0)
                  goto fail;

            strncpy(lookup,name,MAXDNAME);
            BIGLOCK;
            if (variant < __searchdomains && strchr(lookup, '.') == NULL)
            {
                strncat(lookup,".", MAXDNAME);
                strncat(lookup,__searchdomain[variant], MAXDNAME);
            }
            BIGUNLOCK;
            DPRINTF("lookup name: %s\n", lookup);
            q.dotted = (char *)lookup;
            q.qtype = type;
            q.qclass = C_IN; /* CLASS_IN */

            j = __encode_question(&q, packet+i, PACKETSZ-i);
            if (j < 0)
                  goto fail;

            len = i + j;

            DPRINTF("On try %d, sending query to port %d of machine %s\n",
                        retries, NAMESERVER_PORT, dns);

#ifdef __UCLIBC_HAS_IPV6__
            v6 = inet_pton(AF_INET6, dns, &sa6.sin6_addr) > 0;
            fd = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP);
#else
            fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
#endif
            if (fd < 0) {
                continue;
            }

            /* Connect to the UDP socket so that asyncronous errors are returned */        
#ifdef __UCLIBC_HAS_IPV6__
            if (v6) {
                sa6.sin6_family = AF_INET6;
                sa6.sin6_port = htons(NAMESERVER_PORT);
                /* sa6.sin6_addr is already here */
                rc = connect(fd, (struct sockaddr *) &sa6, sizeof(sa6));
            } else {
#endif
                sa.sin_family = AF_INET;
                sa.sin_port = htons(NAMESERVER_PORT);
                sa.sin_addr.s_addr = inet_addr(dns);
                rc = connect(fd, (struct sockaddr *) &sa, sizeof(sa));
#ifdef __UCLIBC_HAS_IPV6__
            }
#endif
            if (rc < 0) {
                if (errno == ENETUNREACH) {
                  /* routing error, presume not transient */
                  goto tryall;
                } else
                  /* retry */
                  continue;
            }

            DPRINTF("Transmitting packet of length %d, id=%d, qr=%d\n",
                        len, h.id, h.qr);

            send(fd, packet, len, 0);

            FD_ZERO(&fds);
            FD_SET(fd, &fds);
            tv.tv_sec = REPLY_TIMEOUT;
            tv.tv_usec = 0;
            if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
                DPRINTF("Timeout\n");

                  /* timed out, so retry send and receive, 
                   * to next nameserver on queue */
                  goto again;
            }

            i = recv(fd, packet, 512, 0);
            if (i < HFIXEDSZ) {
                  /* too short ! */
                  goto again;
            }

            __decode_header(packet, &h);

            DPRINTF("id = %d, qr = %d\n", h.id, h.qr);

            LOCK;
            if ((h.id != id) || (!h.qr)) {
                  UNLOCK;
                  /* unsolicited */
                  goto again;
            }
            UNLOCK;


            DPRINTF("Got response %s\n", "(i think)!");
            DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n",
                        h.qdcount, h.ancount, h.nscount, h.arcount);
            DPRINTF("opcode=%d,aa=%d,tc=%d,rd=%d,ra=%d,rcode=%d\n",
                        h.opcode, h.aa, h.tc, h.rd, h.ra, h.rcode);

            if ((h.rcode) || (h.ancount < 1)) {
                  /* negative result, not present */
                  goto again;
            }

            pos = HFIXEDSZ;

            for (j = 0; j < h.qdcount; j++) {
                  DPRINTF("Skipping question %d at %d\n", j, pos);
                  i = __length_question(packet, pos);
                  DPRINTF("Length of question %d is %d\n", j, i);
                  if (i < 0)
                        goto again;
                  pos += i;
            }
            DPRINTF("Decoding answer at pos %d\n", pos);

            for (j=0;j<h.ancount;j++)
            {
                i = __decode_answer(packet, pos, a);

                if (i<0) {
                  DPRINTF("failed decode %d\n", i);
                  goto again;
                }
                /* For all but T_SIG, accept first answer */
                if (a->atype != T_SIG)
                  break;

                DPRINTF("skipping T_SIG %d\n", i);
                free(a->dotted);
                pos += i;
            }

            DPRINTF("Answer name = |%s|\n", a->dotted);
            DPRINTF("Answer type = |%d|\n", a->atype);

            close(fd);

            if (outpacket)
                  *outpacket = packet;
            else
                  free(packet);
            free(lookup);
            return (0);                   /* success! */

        tryall:
            /* if there are other nameservers, give them a go,
               otherwise return with error */
            {
                int sdomains;

                BIGLOCK;
                sdomains=__searchdomains;
                BIGUNLOCK;
                variant = 0;
                if (retries >= nscount*(sdomains+1))
                  goto fail;
            }

        again:
            /* if there are searchdomains, try them or fallback as passed */
            {
                int sdomains;
                BIGLOCK;
                sdomains=__searchdomains;
                BIGUNLOCK;

                if (variant < sdomains) {
                  /* next search */
                  variant++;
                } else {
                  /* next server, first search */
                  LOCK;
                  ns = (ns + 1) % nscount;
                  UNLOCK;
                  variant = 0;
                }
            }
      }

fail:
      if (fd != -1)
          close(fd);
      if (lookup)
          free(lookup);
      if (packet)
          free(packet);
      return -1;
}

static void __open_etc_hosts(FILE **fp)
{
      if ((*fp = fopen("/etc/hosts", "r")) == NULL) {
            *fp = fopen("/etc/config/hosts", "r");
      }
      return;
}

static int __read_etc_hosts_r(FILE * fp, const char * name, int type,
                 enum etc_hosts_action action,
                 struct hostent * result_buf,
                 char * buf, size_t buflen,
                 struct hostent ** result,
                 int * h_errnop)
{
      struct in_addr    *in=NULL;
      struct in_addr    **addr_list=NULL;
#ifdef __UCLIBC_HAS_IPV6__
      struct in6_addr   *in6=NULL;
      struct in6_addr   **addr_list6=NULL;
#endif /* __UCLIBC_HAS_IPV6__ */
      char                          *cp;
      char                          **alias;
      int                                 aliases, i;
      int         ret=HOST_NOT_FOUND;

      if (buflen < sizeof(char *)*(ALIAS_DIM))
            return ERANGE;
      alias=(char **)buf;
      buf+=sizeof(char **)*(ALIAS_DIM);
      buflen-=sizeof(char **)*(ALIAS_DIM);

      if (action!=GETHOSTENT) {
#ifdef __UCLIBC_HAS_IPV6__
            char *p=buf;
            size_t len=buflen;
#endif /* __UCLIBC_HAS_IPV6__ */
            *h_errnop=NETDB_INTERNAL;
            if (buflen < sizeof(*in))
                  return ERANGE;
            in=(struct in_addr*)buf;
            buf+=sizeof(*in);
            buflen-=sizeof(*in);

            if (buflen < sizeof(*addr_list)*2)
                  return ERANGE;
            addr_list=(struct in_addr **)buf;
            buf+=sizeof(*addr_list)*2;
            buflen-=sizeof(*addr_list)*2;

#ifdef __UCLIBC_HAS_IPV6__
            if (len < sizeof(*in6))
                  return ERANGE;
            in6=(struct in6_addr*)p;
            p+=sizeof(*in6);
            len-=sizeof(*in6);

            if (len < sizeof(*addr_list6)*2)
                  return ERANGE;
            addr_list6=(struct in6_addr**)p;
            p+=sizeof(*addr_list6)*2;
            len-=sizeof(*addr_list6)*2;

            if (len < buflen) {
                  buflen=len;
                  buf=p;
            }
#endif /* __UCLIBC_HAS_IPV6__ */

            if (buflen < 80)
                  return ERANGE;

            __open_etc_hosts(&fp);
            if (fp == NULL) {
                  result=NULL;
                  return errno;
            }
      }

      *h_errnop=HOST_NOT_FOUND;
      while (fgets(buf, buflen, fp)) {
            if ((cp = strchr(buf, '#')))
                  *cp = '\0';
            DPRINTF("Looking at: %s\n", buf);
            aliases = 0;

            cp = buf;
            while (*cp) {
                  while (*cp && isspace(*cp))
                        *cp++ = '\0';
                  if (!*cp)
                        continue;
                  if (aliases < (2+MAX_ALIASES))
                        alias[aliases++] = cp;
                  while (*cp && !isspace(*cp))
                        cp++;
            }
            alias[aliases] = 0;

            if (aliases < 2)
                  continue; /* syntax error really */
            
            if (action==GETHOSTENT) {
                  /* Return whatever the next entry happens to be. */
                  break;
            } else if (action==GET_HOSTS_BYADDR) {
                  if (strcmp(name, alias[0]) != 0)
                        continue;
            } else {
                  /* GET_HOSTS_BYNAME */
                  for (i = 1; i < aliases; i++)
                        if (strcasecmp(name, alias[i]) == 0)
                              break;
                  if (i >= aliases)
                        continue;
            }

            if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
                  DPRINTF("Found INET\n");
                  addr_list[0] = in;
                  addr_list[1] = 0;
                  result_buf->h_name = alias[1];
                  result_buf->h_addrtype = AF_INET;
                  result_buf->h_length = sizeof(*in);
                  result_buf->h_addr_list = (char**) addr_list;
                  result_buf->h_aliases = alias + 2;
                  *result=result_buf;
                  ret=NETDB_SUCCESS;
#ifdef __UCLIBC_HAS_IPV6__
        } else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
                  DPRINTF("Found INET6\n");
                  addr_list6[0] = in6;
                  addr_list6[1] = 0;
                  result_buf->h_name = alias[1];
                  result_buf->h_addrtype = AF_INET6;
                  result_buf->h_length = sizeof(*in6);
                  result_buf->h_addr_list = (char**) addr_list6;
                  result_buf->h_aliases = alias + 2;
                  *result=result_buf;
                  ret=NETDB_SUCCESS;
#endif /* __UCLIBC_HAS_IPV6__ */
            } else {
                  DPRINTF("Error\n");
                  ret=TRY_AGAIN;
                  break; /* bad ip address */
        }
        
            if (action!=GETHOSTENT) {
                  fclose(fp);
            }
            return ret;
      }
      if (action!=GETHOSTENT) {
            fclose(fp);
      }
      return ret;
}

/*
 *    we currently read formats not quite the same as that on normal
 *    unix systems, we can have a list of nameservers after the keyword.
 */
int __get_hosts_byname_r(const char * name, int type,
                      struct hostent * result_buf,
                      char * buf, size_t buflen,
                      struct hostent ** result,
                      int * h_errnop)
{
      return(__read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME, result_buf, buf, buflen, result, h_errnop));
}

static int __open_nameservers()
{
      FILE *fp;
      int i;
#define RESOLV_ARGS 5
      char szBuffer[128], *p, *argv[RESOLV_ARGS];
      int argc;

      BIGLOCK;
      if (__nameservers > 0) { 
          BIGUNLOCK;
          return 0;
      }

      if ((fp = fopen("/etc/resolv.conf", "r")) ||
                  (fp = fopen("/etc/config/resolv.conf", "r"))) {

            while (fgets(szBuffer, sizeof(szBuffer), fp) != NULL) {

                  for (p = szBuffer; *p && isspace(*p); p++)
                        /* skip white space */;
                  if (*p == '\0' || *p == '\n' || *p == '#') /* skip comments etc */
                        continue;
                  argc = 0;
                  while (*p && argc < RESOLV_ARGS) {
                        argv[argc++] = p;
                        while (*p && !isspace(*p) && *p != '\n')
                              p++;
                        while (*p && (isspace(*p) || *p == '\n')) /* remove spaces */
                              *p++ = '\0';
                  }

                  if (strcmp(argv[0], "nameserver") == 0) {
                        for (i = 1; i < argc && __nameservers < MAX_SERVERS; i++) {
                              __nameserver[__nameservers++] = strdup(argv[i]);
                              DPRINTF("adding nameserver %s\n", argv[i]);
                        }
                  }

                  /* domain and search are mutually exclusive, the last one wins */
                  if (strcmp(argv[0],"domain")==0 || strcmp(argv[0],"search")==0) {
                        while (__searchdomains > 0) {
                              free(__searchdomain[--__searchdomains]);
                              __searchdomain[__searchdomains] = NULL;
                        }
                        for (i=1; i < argc && __searchdomains < MAX_SEARCH; i++) {
                              __searchdomain[__searchdomains++] = strdup(argv[i]);
                              DPRINTF("adding search %s\n", argv[i]);
                        }
                  }
            }
            fclose(fp);
      } else {
          DPRINTF("failed to open %s\n", "resolv.conf");
      }
      DPRINTF("nameservers = %d\n", __nameservers);
      BIGUNLOCK;
      return 0;
}

static int sh_gethostbyname_r(const char * name,
                      struct hostent * result_buf,
                      char * buf, size_t buflen,
                      struct hostent ** result,
                      int * h_errnop)
{
      struct in_addr *in;
      struct in_addr **addr_list;
      unsigned char *packet;
      struct resolv_answer a;
      int i;
      int nest = 0;
      int __nameserversXX;
      char ** __nameserverXX;

      __open_nameservers();

      *result=NULL;
      if (!name)
            return EINVAL;

      /* do /etc/hosts first */
      if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
                          buf, buflen, result, h_errnop))==0)
            return i;
      switch (*h_errnop) {
            case HOST_NOT_FOUND:
            case NO_ADDRESS:
                  break;
            case NETDB_INTERNAL:
                  if (errno == ENOENT) {
                      break;
                  }
                  /* else fall through */
            default:
                  return i;
      }

      DPRINTF("Nothing found in /etc/hosts\n");

      *h_errnop = NETDB_INTERNAL;
      if (buflen < sizeof(*in))
            return ERANGE;
      in=(struct in_addr*)buf;
      buf+=sizeof(*in);
      buflen-=sizeof(*in);

      if (buflen < sizeof(*addr_list)*2)
            return ERANGE;
      addr_list=(struct in_addr**)buf;
      buf+=sizeof(*addr_list)*2;
      buflen-=sizeof(*addr_list)*2;

      addr_list[0] = in;
      addr_list[1] = 0;
      
      if (buflen<256)
            return ERANGE;
      strncpy(buf, name, buflen);

      /* First check if this is already an address */
      if (inet_aton(name, in)) {
          result_buf->h_name = buf;
          result_buf->h_addrtype = AF_INET;
          result_buf->h_length = sizeof(*in);
          result_buf->h_addr_list = (char **) addr_list;
          *result=result_buf;
          *h_errnop = NETDB_SUCCESS;
          return NETDB_SUCCESS;
      }

      for (;;) {

      BIGLOCK;
      __nameserversXX=__nameservers;
      __nameserverXX=__nameserver;
      BIGUNLOCK;
            i = __dns_lookup(buf, T_A, __nameserversXX, __nameserverXX, &packet, &a);

            if (i < 0) {
                  *h_errnop = HOST_NOT_FOUND;
                  DPRINTF("__dns_lookup\n");
                  return TRY_AGAIN;
            }

            strncpy(buf, a.dotted, buflen);
            free(a.dotted);

            if (a.atype == T_CNAME) {           /* CNAME */
                  DPRINTF("Got a CNAME in gethostbyname()\n");
                  i = __decode_dotted(packet, a.rdoffset, buf, buflen);
                  free(packet);

                  if (i < 0) {
                        *h_errnop = NO_RECOVERY;
                        DPRINTF("__decode_dotted\n");
                        return -1;
                  }
                  if (++nest > MAX_RECURSE) {
                        *h_errnop = NO_RECOVERY;
                        DPRINTF("recursion\n");
                        return -1;
                  }
                  continue;
            } else if (a.atype == T_A) {  /* ADDRESS */
                  memcpy(in, a.rdata, sizeof(*in));
                  result_buf->h_name = buf;
                  result_buf->h_addrtype = AF_INET;
                  result_buf->h_length = sizeof(*in);
                  result_buf->h_addr_list = (char **) addr_list;
                  free(packet);
                  break;
            } else {
                  free(packet);
                  *h_errnop=HOST_NOT_FOUND;
                  return TRY_AGAIN;
            }
      }

      *result=result_buf;
      *h_errnop = NETDB_SUCCESS;
      return NETDB_SUCCESS;
}

struct hostent * sh_gethostbyname(const char *name)
{
      static struct hostent h;
      static char buf[sizeof(struct in_addr) +
                  sizeof(struct in_addr *)*2 +
                  sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
      struct hostent *hp;

      sh_gethostbyname_r(name, &h, buf, sizeof(buf), &hp, &h_errno);

      return hp;
}

static int __get_hosts_byaddr_r(const char * addr, int len, int type,
                      struct hostent * result_buf,
                      char * buf, size_t buflen,
                      struct hostent ** result,
                      int * h_errnop)
{
#ifndef __UCLIBC_HAS_IPV6__
      char  ipaddr[INET_ADDRSTRLEN];
#else
      char  ipaddr[INET6_ADDRSTRLEN];
#endif /* __UCLIBC_HAS_IPV6__ */

    switch (type) {
      case AF_INET:
            if (len != sizeof(struct in_addr))
                  return 0;
            break;
#ifdef __UCLIBC_HAS_IPV6__
      case AF_INET6:
            if (len != sizeof(struct in6_addr))
                  return 0;
            break;
#endif /* __UCLIBC_HAS_IPV6__ */
      default:
            return 0;
      }

      inet_ntop(type, addr, ipaddr, sizeof(ipaddr));

      return(__read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR, 
                result_buf, buf, buflen, result, h_errnop));
}

static int sh_gethostbyaddr_r (const void *addr, socklen_t len, int type,
                      struct hostent * result_buf,
                      char * buf, size_t buflen,
                      struct hostent ** result,
                      int * h_errnop)

{
      struct in_addr *in;
      struct in_addr **addr_list;
#ifdef __UCLIBC_HAS_IPV6__
      char *qp;
      size_t plen;
      struct in6_addr   *in6;
      struct in6_addr   **addr_list6;
#endif /* __UCLIBC_HAS_IPV6__ */
      unsigned char *packet;
      struct resolv_answer a;
      int i;
      int nest = 0;
      int __nameserversXX;
      char ** __nameserverXX;

      *result=NULL;
      if (!addr)
            return EINVAL;
        
      switch (type) {
            case AF_INET:
                  if (len != sizeof(struct in_addr))
                        return EINVAL;
                  break;
#ifdef __UCLIBC_HAS_IPV6__
            case AF_INET6:
                  if (len != sizeof(struct in6_addr))
                        return EINVAL;
                  break;
#endif /* __UCLIBC_HAS_IPV6__ */
            default:
                  return EINVAL;
      }

      /* do /etc/hosts first */
      if ((i=__get_hosts_byaddr_r(addr, len, type, result_buf,
                          buf, buflen, result, h_errnop))==0)
            return i;
      switch (*h_errnop) {
            case HOST_NOT_FOUND:
            case NO_ADDRESS:
                  break;
            default:
                  return i;
      }

      __open_nameservers();

#ifdef __UCLIBC_HAS_IPV6__
      qp=buf;
      plen=buflen;
#endif /* __UCLIBC_HAS_IPV6__ */

      *h_errnop = NETDB_INTERNAL;
      if (buflen < sizeof(*in))
            return ERANGE;
      in=(struct in_addr*)buf;
      buf+=sizeof(*in);
      buflen-=sizeof(*in);

      if (buflen < sizeof(*addr_list)*2)
            return ERANGE;
      addr_list=(struct in_addr**)buf;
      buf+=sizeof(*addr_list)*2;
      buflen-=sizeof(*addr_list)*2;

#ifdef __UCLIBC_HAS_IPV6__
      if (plen < sizeof(*in6))
            return ERANGE;
      in6=(struct in6_addr*)qp;
      qp+=sizeof(*in6);
      plen-=sizeof(*in6);

      if (plen < sizeof(*addr_list6)*2)
            return ERANGE;
      addr_list6=(struct in6_addr**)qp;
      qp+=sizeof(*addr_list6)*2;
      plen-=sizeof(*addr_list6)*2;

      if (plen < buflen) {
            buflen=plen;
            buf=qp;
      }
#endif /* __UCLIBC_HAS_IPV6__ */

      if (buflen<256)
            return ERANGE;

      if(type == AF_INET) {
            unsigned char *tmp_addr = (unsigned char *)addr;

            memcpy(&in->s_addr, addr, len);

            addr_list[0] = in;

            sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
                  tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
#ifdef __UCLIBC_HAS_IPV6__
      } else {
            memcpy(in6->s6_addr, addr, len);

            addr_list6[0] = in6;
            qp = buf;

            for (i = len - 1; i >= 0; i--) {
                  qp += sprintf(qp, "%x.%x.", in6->s6_addr[i] & 0xf,
                        (in6->s6_addr[i] >> 4) & 0xf);
      }
      strcpy(qp, "ip6.int");
#endif /* __UCLIBC_HAS_IPV6__ */
      }

      addr_list[1] = 0;

      for (;;) {

      BIGLOCK;
      __nameserversXX=__nameservers;
      __nameserverXX=__nameserver;
      BIGUNLOCK;
            i = __dns_lookup(buf, T_PTR, __nameserversXX, __nameserverXX, &packet, &a);

            if (i < 0) {
                  *h_errnop = HOST_NOT_FOUND;
                  return TRY_AGAIN;
            }

            strncpy(buf, a.dotted, buflen);
            free(a.dotted);

            if (a.atype == T_CNAME) {           /* CNAME */
                  DPRINTF("Got a CNAME in gethostbyaddr()\n");
                  i = __decode_dotted(packet, a.rdoffset, buf, buflen);
                  free(packet);

                  if (i < 0) {
                        *h_errnop = NO_RECOVERY;
                        return -1;
                  }
                  if (++nest > MAX_RECURSE) {
                        *h_errnop = NO_RECOVERY;
                        return -1;
                  }
                  continue;
            } else if (a.atype == T_PTR) {      /* ADDRESS */
                  i = __decode_dotted(packet, a.rdoffset, buf, buflen);
                  free(packet);

                  result_buf->h_name = buf;
                  result_buf->h_addrtype = type;

                  if(type == AF_INET) {
                        result_buf->h_length = sizeof(*in);
#ifdef __UCLIBC_HAS_IPV6__
                  } else {
                        result_buf->h_length = sizeof(*in6);
#endif /* __UCLIBC_HAS_IPV6__ */
            }

                  result_buf->h_addr_list = (char **) addr_list;
                  break;
            } else {
                  free(packet);
                  *h_errnop = NO_ADDRESS;
                  return TRY_AGAIN;
            }
      }

      *result=result_buf;
      *h_errnop = NETDB_SUCCESS;
      return NETDB_SUCCESS;
}

struct hostent * sh_gethostbyaddr (const void *addr, socklen_t len, int type)
{
      static struct hostent h;
      static char buf[
#ifndef __UCLIBC_HAS_IPV6__
            sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
#else
            sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
#endif /* __UCLIBC_HAS_IPV6__ */
            sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
      struct hostent *hp;

      sh_gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
        
      return hp;
}

/* NEED_STATIC_LIBS */
#else

/* include something to avoid empty compilation unit */
#include <stdio.h>

#endif


Generated by  Doxygen 1.6.0   Back to index