access.c revision 225736
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