1 /**************************************************************************** 2 * Copyright 2019,2020 Thomas E. Dickey * 3 * Copyright 1998-2011,2012 Free Software Foundation, Inc. * 4 * * 5 * Permission is hereby granted, free of charge, to any person obtaining a * 6 * copy of this software and associated documentation files (the * 7 * "Software"), to deal in the Software without restriction, including * 8 * without limitation the rights to use, copy, modify, merge, publish, * 9 * distribute, distribute with modifications, sublicense, and/or sell * 10 * copies of the Software, and to permit persons to whom the Software is * 11 * furnished to do so, subject to the following conditions: * 12 * * 13 * The above copyright notice and this permission notice shall be included * 14 * in all copies or substantial portions of the Software. * 15 * * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * 19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * 20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * 21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * 22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * 23 * * 24 * Except as contained in this notice, the name(s) of the above copyright * 25 * holders shall not be used in advertising or otherwise to promote the * 26 * sale, use or other dealings in this Software without prior written * 27 * authorization. * 28 ****************************************************************************/ 29 30 /**************************************************************************** 31 * Author: Thomas E. Dickey * 32 ****************************************************************************/ 33 34 #include <curses.priv.h> 35 36 #include <ctype.h> 37 38 #include <tic.h> 39 40 MODULE_ID("$Id: access.c,v 1.25 2020/02/02 23:34:34 tom Exp $") 41 42 #define LOWERCASE(c) ((isalpha(UChar(c)) && isupper(UChar(c))) ? tolower(UChar(c)) : (c)) 43 44 NCURSES_EXPORT(char *) 45 _nc_rootname(char *path) 46 { 47 char *result = _nc_basename(path); 48 #if !MIXEDCASE_FILENAMES || defined(PROG_EXT) 49 static char *temp; 50 char *s; 51 52 temp = strdup(result); 53 result = temp; 54 #if !MIXEDCASE_FILENAMES 55 for (s = result; *s != '\0'; ++s) { 56 *s = (char) LOWERCASE(*s); 57 } 58 #endif 59 #if defined(PROG_EXT) 60 if ((s = strrchr(result, '.')) != 0) { 61 if (!strcmp(s, PROG_EXT)) 62 *s = '\0'; 63 } 64 #endif 65 #endif 66 return result; 67 } 68 69 /* 70 * Check if a string appears to be an absolute pathname. 71 */ 72 NCURSES_EXPORT(bool) 73 _nc_is_abs_path(const char *path) 74 { 75 #if defined(__EMX__) || defined(__DJGPP__) 76 #define is_pathname(s) ((((s) != 0) && ((s)[0] == '/')) \ 77 || (((s)[0] != 0) && ((s)[1] == ':'))) 78 #else 79 #define is_pathname(s) ((s) != 0 && (s)[0] == '/') 80 #endif 81 return is_pathname(path); 82 } 83 84 /* 85 * Return index of the basename 86 */ 87 NCURSES_EXPORT(unsigned) 88 _nc_pathlast(const char *path) 89 { 90 const char *test = strrchr(path, '/'); 91 #ifdef __EMX__ 92 if (test == 0) 93 test = strrchr(path, '\\'); 94 #endif 95 if (test == 0) 96 test = path; 97 else 98 test++; 99 return (unsigned) (test - path); 100 } 101 102 NCURSES_EXPORT(char *) 103 _nc_basename(char *path) 104 { 105 return path + _nc_pathlast(path); 106 } 107 108 NCURSES_EXPORT(int) 109 _nc_access(const char *path, int mode) 110 { 111 int result; 112 113 if (path == 0) { 114 result = -1; 115 } else if (access(path, mode) < 0) { 116 if ((mode & W_OK) != 0 117 && errno == ENOENT 118 && strlen(path) < PATH_MAX) { 119 char head[PATH_MAX]; 120 char *leaf; 121 122 _nc_STRCPY(head, path, sizeof(head)); 123 leaf = _nc_basename(head); 124 if (leaf == 0) 125 leaf = head; 126 *leaf = '\0'; 127 if (head == leaf) 128 _nc_STRCPY(head, ".", sizeof(head)); 129 130 result = access(head, R_OK | W_OK | X_OK); 131 } else { 132 result = -1; 133 } 134 } else { 135 result = 0; 136 } 137 return result; 138 } 139 140 NCURSES_EXPORT(bool) 141 _nc_is_dir_path(const char *path) 142 { 143 bool result = FALSE; 144 struct stat sb; 145 146 if (stat(path, &sb) == 0 147 && S_ISDIR(sb.st_mode)) { 148 result = TRUE; 149 } 150 return result; 151 } 152 153 NCURSES_EXPORT(bool) 154 _nc_is_file_path(const char *path) 155 { 156 bool result = FALSE; 157 struct stat sb; 158 159 if (stat(path, &sb) == 0 160 && S_ISREG(sb.st_mode)) { 161 result = TRUE; 162 } 163 return result; 164 } 165 166 #ifndef USE_ROOT_ENVIRON 167 /* 168 * Returns true if we allow application to use environment variables that are 169 * used for searching lists of directories, etc. 170 */ 171 NCURSES_EXPORT(int) 172 _nc_env_access(void) 173 { 174 #if HAVE_ISSETUGID 175 if (issetugid()) 176 return FALSE; 177 #elif HAVE_GETEUID && HAVE_GETEGID 178 if (getuid() != geteuid() 179 || getgid() != getegid()) 180 return FALSE; 181 #endif 182 /* ...finally, disallow root */ 183 return (getuid() != ROOT_UID) && (geteuid() != ROOT_UID); 184 } 185 #endif 186