LXR busybox/libbb/mode

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * mode_string 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 source tree.
   8 */
   9
  10/* Aug 13, 2003
  11 * Fix a bug reported by junkio@cox.net involving the mode_chars index.
  12 */
  13
  14
  15#include <assert.h>
  16#include <sys/stat.h>
  17
  18#include "libbb.h"
  19
  20#if ( S_ISUID != 04000 ) || ( S_ISGID != 02000 ) || ( S_ISVTX != 01000 ) \
  21 || ( S_IRUSR != 00400 ) || ( S_IWUSR != 00200 ) || ( S_IXUSR != 00100 ) \
  22 || ( S_IRGRP != 00040 ) || ( S_IWGRP != 00020 ) || ( S_IXGRP != 00010 ) \
  23 || ( S_IROTH != 00004 ) || ( S_IWOTH != 00002 ) || ( S_IXOTH != 00001 )
  24#error permission bitflag value assumption(s) violated!
  25#endif
  26
  27#if ( S_IFSOCK!= 0140000 ) || ( S_IFLNK != 0120000 ) \
  28 || ( S_IFREG != 0100000 ) || ( S_IFBLK != 0060000 ) \
  29 || ( S_IFDIR != 0040000 ) || ( S_IFCHR != 0020000 ) \
  30 || ( S_IFIFO != 0010000 )
  31#warning mode type bitflag value assumption(s) violated! falling back to larger version
  32
  33#if (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX) == 07777
  34#undef mode_t
  35#define mode_t unsigned short
  36#endif
  37
  38static const mode_t mode_flags[] = {
  39        S_IRUSR, S_IWUSR, S_IXUSR, S_ISUID,
  40        S_IRGRP, S_IWGRP, S_IXGRP, S_ISGID,
  41        S_IROTH, S_IWOTH, S_IXOTH, S_ISVTX
  42};
  43
  44/* The static const char arrays below are duplicated for the two cases
  45 * because moving them ahead of the mode_flags declaration cause a text
  46 * size increase with the gcc version I'm using. */
  47
  48/* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  49 * and 'B' types don't appear to be available on linux.  So I removed them. */
  50static const char type_chars[16] ALIGN1 = "?pc?d?b?-?l?s???";
  51/***************************************** 0123456789abcdef */
  52static const char mode_chars[7] ALIGN1 = "rwxSTst";
  53
  54const char* FAST_FUNC bb_mode_string(mode_t mode)
  55{
  56        static char buf[12];
  57        char *p = buf;
  58
  59        int i, j, k;
  60
  61        *p = type_chars[ (mode >> 12) & 0xf ];
  62        i = 0;
  63        do {
  64                j = k = 0;
  65                do {
  66                        *++p = '-';
  67                        if (mode & mode_flags[i+j]) {
  68                                *p = mode_chars[j];
  69                                k = j;
  70                        }
  71                } while (++j < 3);
  72                if (mode & mode_flags[i+j]) {
  73                        *p = mode_chars[3 + (k & 2) + ((i&8) >> 3)];
  74                }
  75                i += 4;
  76        } while (i < 12);
  77
  78        /* Note: We don't bother with nul termination because bss initialization
  79         * should have taken care of that for us.  If the user scribbled in buf
  80         * memory, they deserve whatever happens.  But we'll at least assert. */
  81        assert(buf[10] == 0);
  82
  83        return buf;
  84}
  85
  86#else
  87
  88/* The previous version used "0pcCd?bB-?l?s???".  However, the '0', 'C',
  89 * and 'B' types don't appear to be available on linux.  So I removed them. */
  90static const char type_chars[16] = "?pc?d?b?-?l?s???";
  91/********************************** 0123456789abcdef */
  92static const char mode_chars[7] = "rwxSTst";
  93
  94const char* FAST_FUNC bb_mode_string(mode_t mode)
  95{
  96        static char buf[12];
  97        char *p = buf;
  98
  99        int i, j, k, m;
 100
 101        *p = type_chars[ (mode >> 12) & 0xf ];
 102        i = 0;
 103        m = 0400;
 104        do {
 105                j = k = 0;
 106                do {
 107                        *++p = '-';
 108                        if (mode & m) {
 109                                *p = mode_chars[j];
 110                                k = j;
 111                        }
 112                        m >>= 1;
 113                } while (++j < 3);
 114                ++i;
 115                if (mode & (010000 >> i)) {
 116                        *p = mode_chars[3 + (k & 2) + (i == 3)];
 117                }
 118        } while (i < 3);
 119
 120        /* Note: We don't bother with nul termination because bss initialization
 121         * should have taken care of that for us.  If the user scribbled in buf
 122         * memory, they deserve whatever happens.  But we'll at least assert. */
 123        assert(buf[10] == 0);
 124
 125        return buf;
 126}
 127
 128#endif
 129