fs/reiserfs/mode_string.c

   1 /*
   2  * mode_string implementation for busybox
   3  *
   4  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  */
  21
  22 /* Aug 13, 2003
  23  * Fix a bug reported by junkio@cox.net involving the mode_chars index.
  24  */
  25
  26
  27 #include <common.h>
  28 #include <linux/stat.h>
  29
  30 #if ( S_ISUID != 04000 ) || ( S_ISGID != 02000 ) || ( S_ISVTX != 01000 ) \
  31  || ( S_IRUSR != 00400 ) || ( S_IWUSR != 00200 ) || ( S_IXUSR != 00100 ) \
  32  || ( S_IRGRP != 00040 ) || ( S_IWGRP != 00020 ) || ( S_IXGRP != 00010 ) \
  33  || ( S_IROTH != 00004 ) || ( S_IWOTH != 00002 ) || ( S_IXOTH != 00001 )
  34 #error permission bitflag value assumption(s) violated!
  35 #endif
  36
  37 #if ( S_IFSOCK!= 0140000 ) || ( S_IFLNK != 0120000 ) \
  38  || ( S_IFREG != 0100000 ) || ( S_IFBLK != 0060000 ) \
  39  || ( S_IFDIR != 0040000 ) || ( S_IFCHR != 0020000 ) \
  40  || ( S_IFIFO != 0010000 )
  41 #warning mode type bitflag value assumption(s) violated! falling back to larger version
  42
  43 #if (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX) == 07777
  44 #undef mode_t
  45 #define mode_t unsigned short
  46 #endif
  47
  48 static const mode_t mode_flags[] = {
  49         S_IRUSR, S_IWUSR, S_IXUSR, S_ISUID,
  50         S_IRGRP, S_IWGRP, S_IXGRP, S_ISGID,
  51         S_IROTH, S_IWOTH, S_IXOTH, S_ISVTX
  52 };
  53
  54 /* The static const char arrays below are duplicated for the two cases
  55  * because moving them ahead of the mode_flags declaration cause a text
  56  * size increase with the gcc version I'm using. */
  57
  58 /* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  59  * and 'B' types don't appear to be available on linux.  So I removed them. */
  60 static const char type_chars[16] = "?pc?d?b?-?l?s???";
  61 /*                                  0123456789abcdef */
  62 static const char mode_chars[7] = "rwxSTst";
  63
  64 const char *bb_mode_string(int mode)
  65 {
  66         static char buf[12];
  67         char *p = buf;
  68
  69         int i, j, k;
  70
  71         *p = type_chars[ (mode >> 12) & 0xf ];
  72         i = 0;
  73         do {
  74                 j = k = 0;
  75                 do {
  76                         *++p = '-';
  77                         if (mode & mode_flags[i+j]) {
  78                                 *p = mode_chars[j];
  79                                 k = j;
  80                         }
  81                 } while (++j < 3);
  82                 if (mode & mode_flags[i+j]) {
  83                         *p = mode_chars[3 + (k & 2) + ((i&8) >> 3)];
  84                 }
  85                 i += 4;
  86         } while (i < 12);
  87
  88         /* Note: We don't bother with nul termination because bss initialization
  89          * should have taken care of that for us.  If the user scribbled in buf
  90          * memory, they deserve whatever happens.  But we'll at least assert. */
  91         if (buf[10] != 0) return NULL;
  92
  93         return buf;
  94 }
  95
  96 #else
  97
  98 /* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  99  * and 'B' types don't appear to be available on linux.  So I removed them. */
 100 static const char type_chars[16] = "?pc?d?b?-?l?s???";
 101 /*                                  0123456789abcdef */
 102 static const char mode_chars[7] = "rwxSTst";
 103
 104 const char *bb_mode_string(int mode)
 105 {
 106         static char buf[12];
 107         char *p = buf;
 108
 109         int i, j, k, m;
 110
 111         *p = type_chars[ (mode >> 12) & 0xf ];
 112         i = 0;
 113         m = 0400;
 114         do {
 115                 j = k = 0;
 116                 do {
 117                         *++p = '-';
 118                         if (mode & m) {
 119                                 *p = mode_chars[j];
 120                                 k = j;
 121                         }
 122                         m >>= 1;
 123                 } while (++j < 3);
 124                 ++i;
 125                 if (mode & (010000 >> i)) {
 126                         *p = mode_chars[3 + (k & 2) + (i == 3)];
 127                 }
 128         } while (i < 3);
 129
 130         /* Note: We don't bother with nul termination because bss initialization
 131          * should have taken care of that for us.  If the user scribbled in buf
 132          * memory, they deserve whatever happens.  But we'll at least assert. */
 133         if (buf[10] != 0) return NULL;
 134
 135         return buf;
 136 }
 137
 138 #endif