src/common/file_perm.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * File and directory permission routines
   4  *
   5  *
   6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * src/common/file_perm.c
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #include "c.h"
  14
  15 #include "common/file_perm.h"
  16
  17 /* Modes for creating directories and files in the data directory */
  18 int                     pg_dir_create_mode = PG_DIR_MODE_OWNER;
  19 int                     pg_file_create_mode = PG_FILE_MODE_OWNER;
  20
  21 /*
  22  * Mode mask to pass to umask().  This is more of a preventative measure since
  23  * all file/directory creates should be performed using the create modes above.
  24  */
  25 int                     pg_mode_mask = PG_MODE_MASK_OWNER;
  26
  27 /*
  28  * Set create modes and mask to use when writing to PGDATA based on the data
  29  * directory mode passed.  If group read/execute are present in the mode, then
  30  * create modes and mask will be relaxed to allow group read/execute on all
  31  * newly created files and directories.
  32  */
  33 void
  34 SetDataDirectoryCreatePerm(int dataDirMode)
  35 {
  36         /* If the data directory mode has group access */
  37         if ((PG_DIR_MODE_GROUP & dataDirMode) == PG_DIR_MODE_GROUP)
  38         {
  39                 pg_dir_create_mode = PG_DIR_MODE_GROUP;
  40                 pg_file_create_mode = PG_FILE_MODE_GROUP;
  41                 pg_mode_mask = PG_MODE_MASK_GROUP;
  42         }
  43         /* Else use default permissions */
  44         else
  45         {
  46                 pg_dir_create_mode = PG_DIR_MODE_OWNER;
  47                 pg_file_create_mode = PG_FILE_MODE_OWNER;
  48                 pg_mode_mask = PG_MODE_MASK_OWNER;
  49         }
  50 }
  51
  52 #ifdef FRONTEND
  53
  54 /*
  55  * Get the create modes and mask to use when writing to PGDATA by examining the
  56  * mode of the PGDATA directory and calling SetDataDirectoryCreatePerm().
  57  *
  58  * Errors are not handled here and should be reported by the application when
  59  * false is returned.
  60  *
  61  * Suppress when on Windows, because there may not be proper support for Unix-y
  62  * file permissions.  But we still run stat() on the directory so that callers
  63  * get consistent behavior for example if the directory does not exist.
  64  */
  65 bool
  66 GetDataDirectoryCreatePerm(const char *dataDir)
  67 {
  68         struct stat statBuf;
  69
  70         /*
  71          * If an error occurs getting the mode then return false.  The caller is
  72          * responsible for generating an error, if appropriate, indicating that we
  73          * were unable to access the data directory.
  74          */
  75         if (stat(dataDir, &statBuf) == -1)
  76                 return false;
  77
  78 #if !defined(WIN32) && !defined(__CYGWIN__)
  79         /* Set permissions */
  80         SetDataDirectoryCreatePerm(statBuf.st_mode);
  81 #endif
  82
  83         return true;
  84 }
  85
  86
  87 #endif                                                  /* FRONTEND */