cups/tempfile.c

   1 /*
   2  * Temp file utilities for CUPS.
   3  *
   4  * Copyright 2007-2014 by Apple Inc.
   5  * Copyright 1997-2006 by Easy Software Products.
   6  *
   7  * These coded instructions, statements, and computer programs are the
   8  * property of Apple Inc. and are protected by Federal copyright
   9  * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  10  * which should have been included with this file.  If this file is
  11  * file is missing or damaged, see the license at "http://www.cups.org/".
  12  *
  13  * This file is subject to the Apple OS-Developed Software exception.
  14  */
  15
  16 /*
  17  * Include necessary headers...
  18  */
  19
  20 #include "cups-private.h"
  21 #include <stdlib.h>
  22 #include <fcntl.h>
  23 #include <sys/stat.h>
  24 #if defined(WIN32) || defined(__EMX__)
  25 #  include <io.h>
  26 #else
  27 #  include <unistd.h>
  28 #endif /* WIN32 || __EMX__ */
  29
  30
  31 /*
  32  * 'cupsTempFd()' - Creates a temporary file.
  33  *
  34  * The temporary filename is returned in the filename buffer.
  35  * The temporary file is opened for reading and writing.
  36  */
  37
  38 int                                     /* O - New file descriptor or -1 on error */
  39 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  40            int  len)                    /* I - Size of buffer */
  41 {
  42   int           fd;                     /* File descriptor for temp file */
  43   int           tries;                  /* Number of tries */
  44   const char    *tmpdir;                /* TMPDIR environment var */
  45 #ifdef WIN32
  46   char          tmppath[1024];          /* Windows temporary directory */
  47   DWORD         curtime;                /* Current time */
  48 #else
  49   struct timeval curtime;               /* Current time */
  50 #endif /* WIN32 */
  51
  52
  53  /*
  54   * See if TMPDIR is defined...
  55   */
  56
  57 #ifdef WIN32
  58   if ((tmpdir = getenv("TEMP")) == NULL)
  59   {
  60     GetTempPath(sizeof(tmppath), tmppath);
  61     tmpdir = tmppath;
  62   }
  63 #else
  64  /*
  65   * Previously we put root temporary files in the default CUPS temporary
  66   * directory under /var/spool/cups.  However, since the scheduler cleans
  67   * out temporary files there and runs independently of the user apps, we
  68   * don't want to use it unless specifically told to by cupsd.
  69   */
  70
  71   if ((tmpdir = getenv("TMPDIR")) == NULL)
  72 #  if defined(__APPLE__) && !TARGET_OS_IOS
  73     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  74 #  else
  75     tmpdir = "/tmp";
  76 #  endif /* __APPLE__  && !TARGET_OS_IOS */
  77 #endif /* WIN32 */
  78
  79  /*
  80   * Make the temporary name using the specified directory...
  81   */
  82
  83   tries = 0;
  84
  85   do
  86   {
  87 #ifdef WIN32
  88    /*
  89     * Get the current time of day...
  90     */
  91
  92     curtime =  GetTickCount() + tries;
  93
  94    /*
  95     * Format a string using the hex time values...
  96     */
  97
  98     snprintf(filename, (size_t)len - 1, "%s/%05lx%08lx", tmpdir, GetCurrentProcessId(), curtime);
  99 #else
 100    /*
 101     * Get the current time of day...
 102     */
 103
 104     gettimeofday(&curtime, NULL);
 105
 106    /*
 107     * Format a string using the hex time values...
 108     */
 109
 110     snprintf(filename, (size_t)len - 1, "%s/%05x%08x", tmpdir, (unsigned)getpid(), (unsigned)(curtime.tv_sec + curtime.tv_usec + tries));
 111 #endif /* WIN32 */
 112
 113    /*
 114     * Open the file in "exclusive" mode, making sure that we don't
 115     * stomp on an existing file or someone's symlink crack...
 116     */
 117
 118 #ifdef WIN32
 119     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 120               _S_IREAD | _S_IWRITE);
 121 #elif defined(O_NOFOLLOW)
 122     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 123 #else
 124     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 125 #endif /* WIN32 */
 126
 127     if (fd < 0 && errno != EEXIST)
 128       break;
 129
 130     tries ++;
 131   }
 132   while (fd < 0 && tries < 1000);
 133
 134  /*
 135   * Return the file descriptor...
 136   */
 137
 138   return (fd);
 139 }
 140
 141
 142 /*
 143  * 'cupsTempFile()' - Generates a temporary filename.
 144  *
 145  * The temporary filename is returned in the filename buffer.
 146  * This function is deprecated and will no longer generate a temporary
 147  * filename - use @link cupsTempFd@ or @link cupsTempFile2@ instead.
 148  *
 149  * @deprecated@
 150  */
 151
 152 char *                                  /* O - Filename or @code NULL@ on error */
 153 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 154              int  len)                  /* I - Size of buffer */
 155 {
 156   (void)len;
 157
 158   if (filename)
 159     *filename = '\0';
 160
 161   return (NULL);
 162 }
 163
 164
 165 /*
 166  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 167  *
 168  * The temporary filename is returned in the filename buffer.
 169  * The temporary file is opened for writing.
 170  *
 171  * @since CUPS 1.2/macOS 10.5@
 172  */
 173
 174 cups_file_t *                           /* O - CUPS file or @code NULL@ on error */
 175 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 176               int  len)                 /* I - Size of buffer */
 177 {
 178   cups_file_t   *file;                  /* CUPS file */
 179   int           fd;                     /* File descriptor */
 180
 181
 182   if ((fd = cupsTempFd(filename, len)) < 0)
 183     return (NULL);
 184   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 185   {
 186     close(fd);
 187     unlink(filename);
 188     return (NULL);
 189   }
 190   else
 191     return (file);
 192 }