Contents of /trunk/mkinitrd-magellan/busybox/libbb/parse_mode.c
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Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
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Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
File MIME type: text/plain
File size: 3350 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
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 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */ |
11 | |
12 | #include <stdlib.h> |
13 | #include <assert.h> |
14 | #include <sys/stat.h> |
15 | #include "libbb.h" |
16 | |
17 | #define FILEMODEBITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) |
18 | |
19 | int bb_parse_mode(const char *s, mode_t *current_mode) |
20 | { |
21 | static const mode_t who_mask[] = { |
22 | S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO, /* a */ |
23 | S_ISUID | S_IRWXU, /* u */ |
24 | S_ISGID | S_IRWXG, /* g */ |
25 | S_IRWXO /* o */ |
26 | }; |
27 | |
28 | static const mode_t perm_mask[] = { |
29 | S_IRUSR | S_IRGRP | S_IROTH, /* r */ |
30 | S_IWUSR | S_IWGRP | S_IWOTH, /* w */ |
31 | S_IXUSR | S_IXGRP | S_IXOTH, /* x */ |
32 | S_IXUSR | S_IXGRP | S_IXOTH, /* X -- special -- see below */ |
33 | S_ISUID | S_ISGID, /* s */ |
34 | S_ISVTX /* t */ |
35 | }; |
36 | |
37 | static const char who_chars[] = "augo"; |
38 | static const char perm_chars[] = "rwxXst"; |
39 | |
40 | const char *p; |
41 | |
42 | mode_t wholist; |
43 | mode_t permlist; |
44 | mode_t mask; |
45 | mode_t new_mode; |
46 | char op; |
47 | |
48 | assert(s); |
49 | |
50 | if (((unsigned int)(*s - '0')) < 8) { |
51 | unsigned long tmp; |
52 | char *e; |
53 | |
54 | tmp = strtol(s, &e, 8); |
55 | if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */ |
56 | return 0; |
57 | } |
58 | *current_mode = tmp; |
59 | return 1; |
60 | } |
61 | |
62 | mask = umask(0); |
63 | umask(mask); |
64 | |
65 | new_mode = *current_mode; |
66 | |
67 | /* Note: We allow empty clauses, and hence empty modes. |
68 | * We treat an empty mode as no change to perms. */ |
69 | |
70 | while (*s) { /* Process clauses. */ |
71 | |
72 | if (*s == ',') { /* We allow empty clauses. */ |
73 | ++s; |
74 | continue; |
75 | } |
76 | |
77 | /* Get a wholist. */ |
78 | wholist = 0; |
79 | |
80 | WHO_LIST: |
81 | p = who_chars; |
82 | do { |
83 | if (*p == *s) { |
84 | wholist |= who_mask[(int)(p-who_chars)]; |
85 | if (!*++s) { |
86 | return 0; |
87 | } |
88 | goto WHO_LIST; |
89 | } |
90 | } while (*++p); |
91 | |
92 | do { /* Process action list. */ |
93 | if ((*s != '+') && (*s != '-')) { |
94 | if (*s != '=') { |
95 | return 0; |
96 | } |
97 | /* Since op is '=', clear all bits corresponding to the |
98 | * wholist, of all file bits if wholist is empty. */ |
99 | permlist = ~FILEMODEBITS; |
100 | if (wholist) { |
101 | permlist = ~wholist; |
102 | } |
103 | new_mode &= permlist; |
104 | } |
105 | op = *s++; |
106 | |
107 | /* Check for permcopy. */ |
108 | p = who_chars + 1; /* Skip 'a' entry. */ |
109 | do { |
110 | if (*p == *s) { |
111 | int i = 0; |
112 | permlist = who_mask[(int)(p-who_chars)] |
113 | & (S_IRWXU | S_IRWXG | S_IRWXO) |
114 | & new_mode; |
115 | do { |
116 | if (permlist & perm_mask[i]) { |
117 | permlist |= perm_mask[i]; |
118 | } |
119 | } while (++i < 3); |
120 | ++s; |
121 | goto GOT_ACTION; |
122 | } |
123 | } while (*++p); |
124 | |
125 | /* It was not a permcopy, so get a permlist. */ |
126 | permlist = 0; |
127 | |
128 | PERM_LIST: |
129 | p = perm_chars; |
130 | do { |
131 | if (*p == *s) { |
132 | if ((*p != 'X') |
133 | || (new_mode & (S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH)) |
134 | ) { |
135 | permlist |= perm_mask[(int)(p-perm_chars)]; |
136 | } |
137 | if (!*++s) { |
138 | break; |
139 | } |
140 | goto PERM_LIST; |
141 | } |
142 | } while (*++p); |
143 | |
144 | GOT_ACTION: |
145 | if (permlist) { /* The permlist was nonempty. */ |
146 | mode_t tmp = ~mask; |
147 | if (wholist) { |
148 | tmp = wholist; |
149 | } |
150 | permlist &= tmp; |
151 | |
152 | if (op == '-') { |
153 | new_mode &= ~permlist; |
154 | } else { |
155 | new_mode |= permlist; |
156 | } |
157 | } |
158 | } while (*s && (*s != ',')); |
159 | } |
160 | |
161 | *current_mode = new_mode; |
162 | |
163 | return 1; |
164 | } |