1/****************************************************************************
2 * Copyright (c) 1998-2006,2007 Free Software Foundation, Inc.              *
3 *                                                                          *
4 * Permission is hereby granted, free of charge, to any person obtaining a  *
5 * copy of this software and associated documentation files (the            *
6 * "Software"), to deal in the Software without restriction, including      *
7 * without limitation the rights to use, copy, modify, merge, publish,      *
8 * distribute, distribute with modifications, sublicense, and/or sell       *
9 * copies of the Software, and to permit persons to whom the Software is    *
10 * furnished to do so, subject to the following conditions:                 *
11 *                                                                          *
12 * The above copyright notice and this permission notice shall be included  *
13 * in all copies or substantial portions of the Software.                   *
14 *                                                                          *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22 *                                                                          *
23 * Except as contained in this notice, the name(s) of the above copyright   *
24 * holders shall not be used in advertising or otherwise to promote the     *
25 * sale, use or other dealings in this Software without prior written       *
26 * authorization.                                                           *
27 ****************************************************************************/
28
29/****************************************************************************
30 *  Author: Thomas E. Dickey                                                *
31 ****************************************************************************/
32
33#include <curses.priv.h>
34
35#include <ctype.h>
36#include <sys/stat.h>
37
38#include <tic.h>
39#include <nc_alloc.h>
40
41MODULE_ID("$Id: access.c,v 1.14 2007/11/18 00:57:53 tom Exp $")
42
43#define LOWERCASE(c) ((isalpha(UChar(c)) && isupper(UChar(c))) ? tolower(UChar(c)) : (c))
44
45NCURSES_EXPORT(char *)
46_nc_rootname(char *path)
47{
48    char *result = _nc_basename(path);
49#if !MIXEDCASE_FILENAMES || defined(PROG_EXT)
50    static char *temp;
51    char *s;
52
53    temp = strdup(result);
54    result = temp;
55#if !MIXEDCASE_FILENAMES
56    for (s = result; *s != '\0'; ++s) {
57	*s = LOWERCASE(*s);
58    }
59#endif
60#if defined(PROG_EXT)
61    if ((s = strrchr(result, '.')) != 0) {
62	if (!strcmp(s, PROG_EXT))
63	    *s = '\0';
64    }
65#endif
66#endif
67    return result;
68}
69
70/*
71 * Check if a string appears to be an absolute pathname.
72 */
73NCURSES_EXPORT(bool)
74_nc_is_abs_path(const char *path)
75{
76#if defined(__EMX__) || defined(__DJGPP__)
77#define is_pathname(s) ((((s) != 0) && ((s)[0] == '/')) \
78		  || (((s)[0] != 0) && ((s)[1] == ':')))
79#else
80#define is_pathname(s) ((s) != 0 && (s)[0] == '/')
81#endif
82    return is_pathname(path);
83}
84
85/*
86 * Return index of the basename
87 */
88NCURSES_EXPORT(unsigned)
89_nc_pathlast(const char *path)
90{
91    const char *test = strrchr(path, '/');
92#ifdef __EMX__
93    if (test == 0)
94	test = strrchr(path, '\\');
95#endif
96    if (test == 0)
97	test = path;
98    else
99	test++;
100    return (test - path);
101}
102
103NCURSES_EXPORT(char *)
104_nc_basename(char *path)
105{
106    return path + _nc_pathlast(path);
107}
108
109NCURSES_EXPORT(int)
110_nc_access(const char *path, int mode)
111{
112    if (access(path, mode) < 0) {
113	if ((mode & W_OK) != 0
114	    && errno == ENOENT
115	    && strlen(path) < PATH_MAX) {
116	    char head[PATH_MAX];
117	    char *leaf = _nc_basename(strcpy(head, path));
118
119	    if (leaf == 0)
120		leaf = head;
121	    *leaf = '\0';
122	    if (head == leaf)
123		(void) strcpy(head, ".");
124
125	    return access(head, R_OK | W_OK | X_OK);
126	}
127	return -1;
128    }
129    return 0;
130}
131
132NCURSES_EXPORT(bool)
133_nc_is_dir_path(const char *path)
134{
135    bool result = FALSE;
136    struct stat sb;
137
138    if (stat(path, &sb) == 0
139	&& (sb.st_mode & S_IFMT) == S_IFDIR) {
140	result = TRUE;
141    }
142    return result;
143}
144
145NCURSES_EXPORT(bool)
146_nc_is_file_path(const char *path)
147{
148    bool result = FALSE;
149    struct stat sb;
150
151    if (stat(path, &sb) == 0
152	&& (sb.st_mode & S_IFMT) == S_IFREG) {
153	result = TRUE;
154    }
155    return result;
156}
157
158#ifndef USE_ROOT_ENVIRON
159/*
160 * Returns true if we allow application to use environment variables that are
161 * used for searching lists of directories, etc.
162 */
163NCURSES_EXPORT(int)
164_nc_env_access(void)
165{
166#if HAVE_ISSETUGID
167    if (issetugid())
168	return FALSE;
169#elif HAVE_GETEUID && HAVE_GETEGID
170    if (getuid() != geteuid()
171	|| getgid() != getegid())
172	return FALSE;
173#endif
174    return getuid() != 0 && geteuid() != 0;	/* ...finally, disallow root */
175}
176#endif
177