//
// File functions for libppd
//
// Copyright © 2007-2019 by Apple Inc.
// Copyright © 1997-2007 by Easy Software Products, all rights reserved.
//
// Licensed under Apache License v2.0.  See the file "LICENSE" for more
// information.


//
// Include necessary headers...
//

#include <ppd/file-private.h>
#include <ppd/debug-internal.h>
#include <ppd/libcups2-private.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <cups/language.h>

#  ifdef HAVE_LIBZ
#    include <zlib.h>
#  endif // HAVE_LIBZ


//
// Macro for localized text...
//

#  define _(x) x


#ifndef _WIN32
//
// '_ppdFileCheck()' - Check the permissions of the given filename.
//

_ppd_fc_result_t			// O - Check result
_ppdFileCheck(
    const char          *filename,	// I - Filename to check
    _ppd_fc_filetype_t  filetype,	// I - Type of file checks?
    int                 dorootchecks,	// I - Check for root permissions?
    cf_logfunc_t    log,		// I - Log function
    void                *ld)		// I - Data pointer for log function
{
  struct stat		fileinfo;	// File information
  char			message[1024],	// Message string
			temp[1024],	// Parent directory filename
			*ptr;		// Pointer into parent directory
  _ppd_fc_result_t	result;		// Check result


  //
  // Does the filename contain a relative path ("../")?
  //

  if (strstr(filename, "../"))
  {
    //
    // Yes, fail it!
    //

    result = _PPD_FILE_CHECK_RELATIVE_PATH;
    goto finishup;
  }

  //
  // Does the program even exist and is it accessible?
  //

  if (stat(filename, &fileinfo))
  {
    //
    // Nope...
    //

    result = _PPD_FILE_CHECK_MISSING;
    goto finishup;
  }

  //
  // Check the execute bit...
  //

  result = _PPD_FILE_CHECK_OK;

  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
  {
    if (!S_ISDIR(fileinfo.st_mode))
      result = _PPD_FILE_CHECK_WRONG_TYPE;
  }
  else if (!S_ISREG(fileinfo.st_mode))
    result = _PPD_FILE_CHECK_WRONG_TYPE;

  if (result)
    goto finishup;

  //
  // Are we doing root checks?
  //

  if (!dorootchecks)
  {
    //
    // Nope, so anything (else) goes...
    //

    goto finishup;
  }

  //
  // Verify permission of the file itself:
  //
  // 1. Must be owned by root
  // 2. Must not be writable by group
  // 3. Must not be setuid
  // 4. Must not be writable by others
  //

  if (fileinfo.st_uid ||		// 1. Must be owned by root
      (fileinfo.st_mode & S_IWGRP) ||	// 2. Must not be writable by group
      (fileinfo.st_mode & S_ISUID) ||	// 3. Must not be setuid
      (fileinfo.st_mode & S_IWOTH))	// 4. Must not be writable by others
  {
    result = _PPD_FILE_CHECK_PERMISSIONS;
    goto finishup;
  }

  if (filetype == _PPD_FILE_CHECK_DIRECTORY ||
      filetype == _PPD_FILE_CHECK_FILE_ONLY)
    goto finishup;

  //
  // Now check the containing directory...
  //

  strlcpy(temp, filename, sizeof(temp));
  if ((ptr = strrchr(temp, '/')) != NULL)
  {
    if (ptr == temp)
      ptr[1] = '\0';
    else
      *ptr = '\0';
  }

  if (stat(temp, &fileinfo))
  {
    //
    // Doesn't exist?!?
    //

    result   = _PPD_FILE_CHECK_MISSING;
    filetype = _PPD_FILE_CHECK_DIRECTORY;
    filename = temp;

    goto finishup;
  }

  if (fileinfo.st_uid ||		// 1. Must be owned by root
      (fileinfo.st_mode & S_IWGRP) ||	// 2. Must not be writable by group
      (fileinfo.st_mode & S_ISUID) ||	// 3. Must not be setuid
      (fileinfo.st_mode & S_IWOTH))	// 4. Must not be writable by others
  {
    result   = _PPD_FILE_CHECK_PERMISSIONS;
    filetype = _PPD_FILE_CHECK_DIRECTORY;
    filename = temp;
  }

  //
  // Common return point...
  //

  finishup:

  if (log)
  {
    cups_lang_t *lang = cupsLangDefault();
					// Localization information
    cf_loglevel_t loglevel;

    switch (result)
    {
      case _PPD_FILE_CHECK_OK :
	  loglevel = CF_LOGLEVEL_DEBUG;
	  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("Directory \"%s\" permissions OK "
					    "(0%o/uid=%d/gid=%d).")),
		     filename, fileinfo.st_mode, (int)fileinfo.st_uid,
		     (int)fileinfo.st_gid);
	  else
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("File \"%s\" permissions OK "
					    "(0%o/uid=%d/gid=%d).")),
		     filename, fileinfo.st_mode, (int)fileinfo.st_uid,
		     (int)fileinfo.st_gid);
          break;

      case _PPD_FILE_CHECK_MISSING :
	  loglevel = CF_LOGLEVEL_ERROR;
	  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("Directory \"%s\" not available: "
					    "%s")),
		     filename, strerror(errno));
	  else
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("File \"%s\" not available: %s")),
		     filename, strerror(errno));
          break;

      case _PPD_FILE_CHECK_PERMISSIONS :
	  loglevel = CF_LOGLEVEL_ERROR;
	  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("Directory \"%s\" has insecure "
					    "permissions "
					    "(0%o/uid=%d/gid=%d).")),
		     filename, fileinfo.st_mode, (int)fileinfo.st_uid,
		     (int)fileinfo.st_gid);
	  else
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("File \"%s\" has insecure "
					    "permissions "
					    "(0%o/uid=%d/gid=%d).")),
		     filename, fileinfo.st_mode, (int)fileinfo.st_uid,
		     (int)fileinfo.st_gid);
          break;

      case _PPD_FILE_CHECK_WRONG_TYPE :
	  loglevel = CF_LOGLEVEL_ERROR;
	  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("Directory \"%s\" is a file.")),
		     filename);
	  else
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("File \"%s\" is a directory.")),
		     filename);
          break;

      case _PPD_FILE_CHECK_RELATIVE_PATH :
	  loglevel = CF_LOGLEVEL_ERROR;
	  if (filetype == _PPD_FILE_CHECK_DIRECTORY)
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("Directory \"%s\" contains a "
					    "relative path.")), filename);
	  else
	    snprintf(message, sizeof(message),
		     cupsLangGetString(lang, _("File \"%s\" contains a relative "
					    "path.")), filename);
          break;
    }

    log(ld, loglevel, message);
  }

  return (result);
}
#endif // !_WIN32