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  * Licensed under Apache License v2.0.  See the file "LICENSE" for more information.
   8  */
   9
  10 /*
  11  * Include necessary headers...
  12  */
  13
  14 #include "cups-private.h"
  15 #include <stdlib.h>
  16 #include <fcntl.h>
  17 #include <sys/stat.h>
  18 #if defined(WIN32) || defined(__EMX__)
  19 #  include <io.h>
  20 #else
  21 #  include <unistd.h>
  22 #endif /* WIN32 || __EMX__ */
  23
  24
  25 /*
  26  * 'cupsTempFd()' - Creates a temporary file.
  27  *
  28  * The temporary filename is returned in the filename buffer.
  29  * The temporary file is opened for reading and writing.
  30  */
  31
  32 int                                     /* O - New file descriptor or -1 on error */
  33 cupsTempFd(char *filename,              /* I - Pointer to buffer */
  34            int  len)                    /* I - Size of buffer */
  35 {
  36   int           fd;                     /* File descriptor for temp file */
  37   int           tries;                  /* Number of tries */
  38   const char    *tmpdir;                /* TMPDIR environment var */
  39 #ifdef WIN32
  40   char          tmppath[1024];          /* Windows temporary directory */
  41   DWORD         curtime;                /* Current time */
  42 #else
  43   struct timeval curtime;               /* Current time */
  44 #endif /* WIN32 */
  45
  46
  47  /*
  48   * See if TMPDIR is defined...
  49   */
  50
  51 #ifdef WIN32
  52   if ((tmpdir = getenv("TEMP")) == NULL)
  53   {
  54     GetTempPath(sizeof(tmppath), tmppath);
  55     tmpdir = tmppath;
  56   }
  57 #else
  58  /*
  59   * Previously we put root temporary files in the default CUPS temporary
  60   * directory under /var/spool/cups.  However, since the scheduler cleans
  61   * out temporary files there and runs independently of the user apps, we
  62   * don't want to use it unless specifically told to by cupsd.
  63   */
  64
  65   if ((tmpdir = getenv("TMPDIR")) == NULL)
  66 #  if defined(__APPLE__) && !TARGET_OS_IOS
  67     tmpdir = "/private/tmp";            /* /tmp is a symlink to /private/tmp */
  68 #  else
  69     tmpdir = "/tmp";
  70 #  endif /* __APPLE__  && !TARGET_OS_IOS */
  71 #endif /* WIN32 */
  72
  73  /*
  74   * Make the temporary name using the specified directory...
  75   */
  76
  77   tries = 0;
  78
  79   do
  80   {
  81 #ifdef WIN32
  82    /*
  83     * Get the current time of day...
  84     */
  85
  86     curtime =  GetTickCount() + tries;
  87
  88    /*
  89     * Format a string using the hex time values...
  90     */
  91
  92     snprintf(filename, (size_t)len - 1, "%s/%05lx%08lx", tmpdir, GetCurrentProcessId(), curtime);
  93 #else
  94    /*
  95     * Get the current time of day...
  96     */
  97
  98     gettimeofday(&curtime, NULL);
  99
 100    /*
 101     * Format a string using the hex time values...
 102     */
 103
 104     snprintf(filename, (size_t)len - 1, "%s/%05x%08x", tmpdir, (unsigned)getpid(), (unsigned)(curtime.tv_sec + curtime.tv_usec + tries));
 105 #endif /* WIN32 */
 106
 107    /*
 108     * Open the file in "exclusive" mode, making sure that we don't
 109     * stomp on an existing file or someone's symlink crack...
 110     */
 111
 112 #ifdef WIN32
 113     fd = open(filename, _O_CREAT | _O_RDWR | _O_TRUNC | _O_BINARY,
 114               _S_IREAD | _S_IWRITE);
 115 #elif defined(O_NOFOLLOW)
 116     fd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 117 #else
 118     fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 119 #endif /* WIN32 */
 120
 121     if (fd < 0 && errno != EEXIST)
 122       break;
 123
 124     tries ++;
 125   }
 126   while (fd < 0 && tries < 1000);
 127
 128  /*
 129   * Return the file descriptor...
 130   */
 131
 132   return (fd);
 133 }
 134
 135
 136 /*
 137  * 'cupsTempFile()' - Generates a temporary filename.
 138  *
 139  * The temporary filename is returned in the filename buffer.
 140  * This function is deprecated and will no longer generate a temporary
 141  * filename - use @link cupsTempFd@ or @link cupsTempFile2@ instead.
 142  *
 143  * @deprecated@
 144  */
 145
 146 char *                                  /* O - Filename or @code NULL@ on error */
 147 cupsTempFile(char *filename,            /* I - Pointer to buffer */
 148              int  len)                  /* I - Size of buffer */
 149 {
 150   (void)len;
 151
 152   if (filename)
 153     *filename = '\0';
 154
 155   return (NULL);
 156 }
 157
 158
 159 /*
 160  * 'cupsTempFile2()' - Creates a temporary CUPS file.
 161  *
 162  * The temporary filename is returned in the filename buffer.
 163  * The temporary file is opened for writing.
 164  *
 165  * @since CUPS 1.2/macOS 10.5@
 166  */
 167
 168 cups_file_t *                           /* O - CUPS file or @code NULL@ on error */
 169 cupsTempFile2(char *filename,           /* I - Pointer to buffer */
 170               int  len)                 /* I - Size of buffer */
 171 {
 172   cups_file_t   *file;                  /* CUPS file */
 173   int           fd;                     /* File descriptor */
 174
 175
 176   if ((fd = cupsTempFd(filename, len)) < 0)
 177     return (NULL);
 178   else if ((file = cupsFileOpenFd(fd, "w")) == NULL)
 179   {
 180     close(fd);
 181     unlink(filename);
 182     return (NULL);
 183   }
 184   else
 185     return (file);
 186 }