1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) tons of folks.  Tracking down who wrote what
6 * isn't something I'm going to worry about...  If you wrote something
7 * here, please feel free to acknowledge your work.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
24 * Permission has been granted to redistribute this code under the GPL.
25 *
26 */
27
28#include <stdio.h>
29#include <stdlib.h>
30#include "libbb.h"
31
32
33/* This function parses the sort of string you might pass
34 * to chmod (i.e., [ugoa]{+|-|=}[rwxst] ) and returns the
35 * correct mode described by the string. */
36extern int parse_mode(const char *s, mode_t * theMode)
37{
38	static const mode_t group_set[] = {
39		S_ISUID | S_IRWXU,		/* u */
40		S_ISGID | S_IRWXG,		/* g */
41		S_IRWXO,				/* o */
42		S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO /* a */
43	};
44
45	static const mode_t mode_set[] = {
46		S_IRUSR | S_IRGRP | S_IROTH, /* r */
47		S_IWUSR | S_IWGRP | S_IWOTH, /* w */
48		S_IXUSR | S_IXGRP | S_IXOTH, /* x */
49		S_ISUID | S_ISGID,		/* s */
50		S_ISVTX					/* t */
51	};
52
53	static const char group_chars[] = "ugoa";
54	static const char mode_chars[] = "rwxst";
55
56	const char *p;
57
58	mode_t andMode =
59		S_ISVTX | S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
60	mode_t orMode = 0;
61	mode_t mode;
62	mode_t groups;
63	char type;
64	char c;
65
66	if (s==NULL) {
67		return (FALSE);
68	}
69
70	do {
71		mode = 0;
72		groups = 0;
73	NEXT_GROUP:
74		if ((c = *s++) == '\0') {
75			return -1;
76		}
77		for (p=group_chars ; *p ; p++) {
78			if (*p == c) {
79				groups |= group_set[(int)(p-group_chars)];
80				goto NEXT_GROUP;
81			}
82		}
83		switch (c) {
84			case '=':
85			case '+':
86			case '-':
87				type = c;
88				if (groups == 0) { /* The default is "all" */
89					groups |= S_ISUID | S_ISGID | S_ISVTX
90							| S_IRWXU | S_IRWXG | S_IRWXO;
91				}
92				break;
93			default:
94				if ((c < '0') || (c > '7') || (mode | groups)) {
95					return (FALSE);
96				} else {
97					*theMode = strtol(--s, NULL, 8);
98					return (TRUE);
99				}
100		}
101
102	NEXT_MODE:
103		if (((c = *s++) != '\0') && (c != ',')) {
104			for (p=mode_chars ; *p ; p++) {
105				if (*p == c) {
106					mode |= mode_set[(int)(p-mode_chars)];
107					goto NEXT_MODE;
108				}
109			}
110			break;				/* We're done so break out of loop.*/
111		}
112		switch (type) {
113			case '=':
114				andMode &= ~(groups); /* Now fall through. */
115			case '+':
116				orMode |= mode & groups;
117				break;
118			case '-':
119				andMode &= ~(mode & groups);
120				orMode &= ~(mode & groups);
121				break;
122		}
123	} while (c == ',');
124
125	*theMode &= andMode;
126	*theMode |= orMode;
127
128	return TRUE;
129}
130
131/* END CODE */
132/*
133Local Variables:
134c-file-style: "linux"
135c-basic-offset: 4
136tab-width: 4
137End:
138*/
139