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Sourcecode: udev version File versions

udev_libc_wrapper.c

/*
 * udev_libc_wrapper - wrapping of functions missing in a specific libc
 *                 or not working in a statically compiled binary
 *
 * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2005 Kay Sievers <kay@vrfy.org>
 *
 *    This program is free software; you can redistribute it and/or modify it
 *    under the terms of the GNU General Public License as published by the
 *    Free Software Foundation version 2 of the License.
 * 
 *    This program 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
 *    General Public License for more details.
 * 
 *    You should have received a copy of the GNU General Public License along
 *    with this program; if not, write to the Free Software Foundation, Inc.,
 *    675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/types.h>

#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_utils.h"
#include "logging.h"

#ifdef __KLIBC__
#define __OWN_USERDB_PARSER__
#endif

#ifdef USE_STATIC
#define __OWN_USERDB_PARSER__
#endif

#ifndef strlcpy
size_t strlcpy(char *dst, const char *src, size_t size)
{
      size_t bytes = 0;
      char *q = dst;
      const char *p = src;
      char ch;

      while ((ch = *p++)) {
            if (bytes < size)
                  *q++ = ch;
            bytes++;
      }

      *q = '\0';
      return bytes;
}
#endif

#ifndef strlcat
size_t strlcat(char *dst, const char *src, size_t size)
{
      size_t bytes = 0;
      char *q = dst;
      const char *p = src;
      char ch;

      while (bytes < size && *q) {
            q++;
            bytes++;
      }

      while ((ch = *p++)) {
            if (bytes < size)
            *q++ = ch;
            bytes++;
      }

      *q = '\0';
      return bytes;
}
#endif

#ifndef __OWN_USERDB_PARSER__
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>

uid_t lookup_user(const char *user)
{
      struct passwd *pw;
      uid_t uid = 0;

      pw = getpwnam(user);
      if (pw == NULL)
            dbg("specified user unknown '%s'", user);
      else
            uid = pw->pw_uid;

      return uid;
}

gid_t lookup_group(const char *group)
{
      struct group *gr;
      gid_t gid = 0;

      gr = getgrnam(group);
      if (gr == NULL)
            dbg("specified group unknown '%s'", group);
      else
            gid = gr->gr_gid;

      return gid;
}

#else /* __OWN_USERDB_PARSER__ */

#define PASSWD_FILE           "/etc/passwd"
#define GROUP_FILE            "/etc/group"

/* return the id of a passwd style line, selected by the users name */
static unsigned long get_id_by_name(const char *uname, const char *dbfile)
{
      unsigned long id = 0;
      char line[LINE_SIZE];
      char *buf;
      char *bufline;
      size_t bufsize;
      size_t cur;
      size_t count;
      char *pos;
      char *name;
      char *idstr;
      char *tail;

      if (file_map(dbfile, &buf, &bufsize) != 0) {
            dbg("can't open '%s' as db file", dbfile);
            return 0;
      }
      dbg("search '%s' in '%s'", uname, dbfile);

      /* loop through the whole file */
      cur = 0;
      while (cur < bufsize) {
            count = buf_get_line(buf, bufsize, cur);
            bufline = &buf[cur];
            cur += count+1;

            if (count >= sizeof(line))
                  continue;

            strlcpy(line, bufline, count);
            pos = line;

            /* get name */
            name = strsep(&pos, ":");
            if (name == NULL)
                  continue;

            /* skip pass */
            if (strsep(&pos, ":") == NULL)
                  continue;

            /* get id */
            idstr = strsep(&pos, ":");
            if (idstr == NULL)
                  continue;

            if (strcmp(uname, name) == 0) {
                  id = strtoul(idstr, &tail, 10);
                  if (tail[0] != '\0') {
                        id = 0;
                        dbg("no id found for '%s'",  name);
                  } else
                        dbg("id for '%s' is '%li'", name, id);
                  break;
            }
      }

      file_unmap(buf, bufsize);
      return id;
}

uid_t lookup_user(const char *user)
{
      unsigned long id;

      id = get_id_by_name(user, PASSWD_FILE);
      return (uid_t) id;
}

gid_t lookup_group(const char *group)
{
      unsigned long id;

      id = get_id_by_name(group, GROUP_FILE);
      return (gid_t) id;
}
#endif /* __OWN_USERDB_PARSER__ */

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