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  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 /* Aug 13, 2003
  10  * Fix a bug reported by junkio@cox.net involving the mode_chars index.
  11  */
  12
  13
  14 #include <common.h>
  15 #include <linux/stat.h>
  16
  17 #if ( S_ISUID != 04000 ) || ( S_ISGID != 02000 ) || ( S_ISVTX != 01000 ) \
  18  || ( S_IRUSR != 00400 ) || ( S_IWUSR != 00200 ) || ( S_IXUSR != 00100 ) \
  19  || ( S_IRGRP != 00040 ) || ( S_IWGRP != 00020 ) || ( S_IXGRP != 00010 ) \
  20  || ( S_IROTH != 00004 ) || ( S_IWOTH != 00002 ) || ( S_IXOTH != 00001 )
  21 #error permission bitflag value assumption(s) violated!
  22 #endif
  23
  24 #if ( S_IFSOCK!= 0140000 ) || ( S_IFLNK != 0120000 ) \
  25  || ( S_IFREG != 0100000 ) || ( S_IFBLK != 0060000 ) \
  26  || ( S_IFDIR != 0040000 ) || ( S_IFCHR != 0020000 ) \
  27  || ( S_IFIFO != 0010000 )
  28 #warning mode type bitflag value assumption(s) violated! falling back to larger version
  29
  30 #if (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX) == 07777
  31 #undef mode_t
  32 #define mode_t unsigned short
  33 #endif
  34
  35 static const mode_t mode_flags[] = {
  36         S_IRUSR, S_IWUSR, S_IXUSR, S_ISUID,
  37         S_IRGRP, S_IWGRP, S_IXGRP, S_ISGID,
  38         S_IROTH, S_IWOTH, S_IXOTH, S_ISVTX
  39 };
  40
  41 /* The static const char arrays below are duplicated for the two cases
  42  * because moving them ahead of the mode_flags declaration cause a text
  43  * size increase with the gcc version I'm using. */
  44
  45 /* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  46  * and 'B' types don't appear to be available on linux.  So I removed them. */
  47 static const char type_chars[16] = "?pc?d?b?-?l?s???";
  48 /*                                  0123456789abcdef */
  49 static const char mode_chars[7] = "rwxSTst";
  50
  51 const char *bb_mode_string(int mode)
  52 {
  53         static char buf[12];
  54         char *p = buf;
  55
  56         int i, j, k;
  57
  58         *p = type_chars[ (mode >> 12) & 0xf ];
  59         i = 0;
  60         do {
  61                 j = k = 0;
  62                 do {
  63                         *++p = '-';
  64                         if (mode & mode_flags[i+j]) {
  65                                 *p = mode_chars[j];
  66                                 k = j;
  67                         }
  68                 } while (++j < 3);
  69                 if (mode & mode_flags[i+j]) {
  70                         *p = mode_chars[3 + (k & 2) + ((i&8) >> 3)];
  71                 }
  72                 i += 4;
  73         } while (i < 12);
  74
  75         /* Note: We don't bother with nul termination because bss initialization
  76          * should have taken care of that for us.  If the user scribbled in buf
  77          * memory, they deserve whatever happens.  But we'll at least assert. */
  78         if (buf[10] != 0) return NULL;
  79
  80         return buf;
  81 }
  82
  83 #else
  84
  85 /* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  86  * and 'B' types don't appear to be available on linux.  So I removed them. */
  87 static const char type_chars[16] = "?pc?d?b?-?l?s???";
  88 /*                                  0123456789abcdef */
  89 static const char mode_chars[7] = "rwxSTst";
  90
  91 const char *bb_mode_string(int mode)
  92 {
  93         static char buf[12];
  94         char *p = buf;
  95
  96         int i, j, k, m;
  97
  98         *p = type_chars[ (mode >> 12) & 0xf ];
  99         i = 0;
 100         m = 0400;
 101         do {
 102                 j = k = 0;
 103                 do {
 104                         *++p = '-';
 105                         if (mode & m) {
 106                                 *p = mode_chars[j];
 107                                 k = j;
 108                         }
 109                         m >>= 1;
 110                 } while (++j < 3);
 111                 ++i;
 112                 if (mode & (010000 >> i)) {
 113                         *p = mode_chars[3 + (k & 2) + (i == 3)];
 114                 }
 115         } while (i < 3);
 116
 117         /* Note: We don't bother with nul termination because bss initialization
 118          * should have taken care of that for us.  If the user scribbled in buf
 119          * memory, they deserve whatever happens.  But we'll at least assert. */
 120         if (buf[10] != 0) return NULL;
 121
 122         return buf;
 123 }
 124
 125 #endif