release/src/router/busybox/libbb/make_directory.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * parse_mode implementation for busybox
   4  *
   5  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8  */
   9
  10 /* Mar 5, 2003    Manuel Novoa III
  11  *
  12  * This is the main work function for the 'mkdir' applet.  As such, it
  13  * strives to be SUSv3 compliant in it's behaviour when recursively
  14  * making missing parent dirs, and in it's mode setting of the final
  15  * directory 'path'.
  16  *
  17  * To recursively build all missing intermediate directories, make
  18  * sure that (flags & FILEUTILS_RECUR) is non-zero.  Newly created
  19  * intermediate directories will have at least u+wx perms.
  20  *
  21  * To set specific permissions on 'path', pass the appropriate 'mode'
  22  * val.  Otherwise, pass -1 to get default permissions.
  23  */
  24
  25 #include "libbb.h"
  26
  27 /* This function is used from NOFORK applets. It must not allocate anything */
  28
  29 int FAST_FUNC bb_make_directory(char *path, long mode, int flags)
  30 {
  31         mode_t mask;
  32         const char *fail_msg;
  33         char *s = path;
  34         char c;
  35         struct stat st;
  36
  37         mask = umask(0);
  38         umask(mask & ~0300); /* Ensure intermediate dirs are wx */
  39
  40         while (1) {
  41                 c = '\0';
  42
  43                 if (flags & FILEUTILS_RECUR) {  /* Get the parent. */
  44                         /* Bypass leading non-'/'s and then subsequent '/'s. */
  45                         while (*s) {
  46                                 if (*s == '/') {
  47                                         do {
  48                                                 ++s;
  49                                         } while (*s == '/');
  50                                         c = *s; /* Save the current char */
  51                                         *s = '\0'; /* and replace it with nul. */
  52                                         break;
  53                                 }
  54                                 ++s;
  55                         }
  56                 }
  57
  58                 if (!c) /* Last component uses orig umask */
  59                         umask(mask);
  60
  61                 if (mkdir(path, 0777) < 0) {
  62                         /* If we failed for any other reason than the directory
  63                          * already exists, output a diagnostic and return -1. */
  64                         if (errno != EEXIST
  65                          || !(flags & FILEUTILS_RECUR)
  66                          || ((stat(path, &st) < 0) || !S_ISDIR(st.st_mode))
  67                         ) {
  68                                 fail_msg = "create";
  69                                 umask(mask);
  70                                 break;
  71                         }
  72                         /* Since the directory exists, don't attempt to change
  73                          * permissions if it was the full target.  Note that
  74                          * this is not an error condition. */
  75                         if (!c) {
  76                                 umask(mask);
  77                                 return 0;
  78                         }
  79                 }
  80
  81                 if (!c) {
  82                         /* Done.  If necessary, update perms on the newly
  83                          * created directory.  Failure to update here _is_
  84                          * an error. */
  85                         if ((mode != -1) && (chmod(path, mode) < 0)) {
  86                                 fail_msg = "set permissions of";
  87                                 break;
  88                         }
  89                         return 0;
  90                 }
  91
  92                 /* Remove any inserted nul from the path (recursive mode). */
  93                 *s = c;
  94         } /* while (1) */
  95
  96         bb_perror_msg("cannot %s directory '%s'", fail_msg, path);
  97         return -1;
  98 }