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 tarball for details.
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