/****************************************************************************
- * Copyright (c) 1998,2000 Free Software Foundation, Inc. *
+ * Copyright 2019-2020,2021 Thomas E. Dickey *
+ * Copyright 1998-2011,2012 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
****************************************************************************/
/****************************************************************************
- * Author: Thomas E. Dickey <dickey@clark.net> 1998,2000 *
+ * Author: Thomas E. Dickey *
****************************************************************************/
#include <curses.priv.h>
+
+#include <ctype.h>
+
+#ifndef USE_ROOT_ACCESS
+#if HAVE_SETFSUID
+#include <sys/fsuid.h>
+#else
+#include <sys/stat.h>
+#endif
+#endif
+
#include <tic.h>
-MODULE_ID("$Id: access.c,v 1.4 2000/10/08 01:25:06 tom Exp $")
+MODULE_ID("$Id: access.c,v 1.31 2021/08/29 10:35:17 tom Exp $")
-char *
-_nc_basename(char *path)
+#define LOWERCASE(c) ((isalpha(UChar(c)) && isupper(UChar(c))) ? tolower(UChar(c)) : (c))
+
+#ifdef _NC_MSC
+# define ACCESS(FN, MODE) access((FN), (MODE)&(R_OK|W_OK))
+#else
+# define ACCESS access
+#endif
+
+NCURSES_EXPORT(char *)
+_nc_rootname(char *path)
{
- char *result = strrchr(path, '/');
+ char *result = _nc_basename(path);
+#if !MIXEDCASE_FILENAMES || defined(PROG_EXT)
+ static char *temp;
+ char *s;
+
+ temp = strdup(result);
+ result = temp;
+#if !MIXEDCASE_FILENAMES
+ for (s = result; *s != '\0'; ++s) {
+ *s = (char) LOWERCASE(*s);
+ }
+#endif
+#if defined(PROG_EXT)
+ if ((s = strrchr(result, '.')) != 0) {
+ if (!strcmp(s, PROG_EXT))
+ *s = '\0';
+ }
+#endif
+#endif
+ return result;
+}
+
+/*
+ * Check if a string appears to be an absolute pathname.
+ */
+NCURSES_EXPORT(bool)
+_nc_is_abs_path(const char *path)
+{
+#if defined(__EMX__) || defined(__DJGPP__)
+#define is_pathname(s) ((((s) != 0) && ((s)[0] == '/')) \
+ || (((s)[0] != 0) && ((s)[1] == ':')))
+#else
+#define is_pathname(s) ((s) != 0 && (s)[0] == '/')
+#endif
+ return is_pathname(path);
+}
+
+/*
+ * Return index of the basename
+ */
+NCURSES_EXPORT(unsigned)
+_nc_pathlast(const char *path)
+{
+ const char *test = strrchr(path, '/');
#ifdef __EMX__
- if (result == 0)
- result = strrchr(path, '\\');
+ if (test == 0)
+ test = strrchr(path, '\\');
#endif
- if (result == 0)
- result = path;
+ if (test == 0)
+ test = path;
else
- result++;
- return result;
+ test++;
+ return (unsigned) (test - path);
+}
+
+NCURSES_EXPORT(char *)
+_nc_basename(char *path)
+{
+ return path + _nc_pathlast(path);
}
-int
+NCURSES_EXPORT(int)
_nc_access(const char *path, int mode)
{
- if (access(path, mode) < 0) {
+ int result;
+
+ if (path == 0) {
+ result = -1;
+ } else if (ACCESS(path, mode) < 0) {
if ((mode & W_OK) != 0
&& errno == ENOENT
&& strlen(path) < PATH_MAX) {
char head[PATH_MAX];
- char *leaf = _nc_basename(strcpy(head, path));
+ char *leaf;
+ _nc_STRCPY(head, path, sizeof(head));
+ leaf = _nc_basename(head);
if (leaf == 0)
leaf = head;
*leaf = '\0';
if (head == leaf)
- (void) strcpy(head, ".");
+ _nc_STRCPY(head, ".", sizeof(head));
- return access(head, R_OK | W_OK | X_OK);
+ result = ACCESS(head, R_OK | W_OK | X_OK);
+ } else {
+ result = -1;
}
- return -1;
+ } else {
+ result = 0;
}
- return 0;
+ return result;
}
+NCURSES_EXPORT(bool)
+_nc_is_dir_path(const char *path)
+{
+ bool result = FALSE;
+ struct stat sb;
+
+ if (stat(path, &sb) == 0
+ && S_ISDIR(sb.st_mode)) {
+ result = TRUE;
+ }
+ return result;
+}
+
+NCURSES_EXPORT(bool)
+_nc_is_file_path(const char *path)
+{
+ bool result = FALSE;
+ struct stat sb;
+
+ if (stat(path, &sb) == 0
+ && S_ISREG(sb.st_mode)) {
+ result = TRUE;
+ }
+ return result;
+}
+
+#if HAVE_ISSETUGID
+#define is_elevated() issetugid()
+#elif HAVE_GETEUID && HAVE_GETEGID
+#define is_elevated() \
+ (getuid() != geteuid() \
+ || getgid() != getegid())
+#else
+#define is_elevated() FALSE
+#endif
+
+#if HAVE_SETFSUID
+#define lower_privileges() \
+ int save_err = errno; \
+ setfsuid(getuid()); \
+ setfsgid(getgid()); \
+ errno = save_err
+#define resume_elevation() \
+ save_err = errno; \
+ setfsuid(geteuid()); \
+ setfsgid(getegid()); \
+ errno = save_err
+#else
+#define lower_privileges() /* nothing */
+#define resume_elevation() /* nothing */
+#endif
+
#ifndef USE_ROOT_ENVIRON
/*
* Returns true if we allow application to use environment variables that are
* used for searching lists of directories, etc.
*/
-int
+NCURSES_EXPORT(int)
_nc_env_access(void)
{
-#if HAVE_ISSETUGID
- if (issetugid())
- return FALSE;
-#elif HAVE_GETEUID && HAVE_GETEGID
- if (getuid() != geteuid()
- || getgid() != getegid())
- return FALSE;
+ int result = TRUE;
+
+ if (is_elevated()) {
+ result = FALSE;
+ } else if ((getuid() == ROOT_UID) || (geteuid() == ROOT_UID)) {
+ result = FALSE;
+ }
+ return result;
+}
+#endif /* USE_ROOT_ENVIRON */
+
+#ifndef USE_ROOT_ACCESS
+/*
+ * Limit privileges if possible; otherwise disallow access for updating files.
+ */
+NCURSES_EXPORT(FILE *)
+_nc_safe_fopen(const char *path, const char *mode)
+{
+ FILE *result = NULL;
+#if HAVE_SETFSUID
+ lower_privileges();
+ result = fopen(path, mode);
+ resume_elevation();
+#else
+ if (!is_elevated() || *mode == 'r') {
+ result = fopen(path, mode);
+ }
#endif
- return getuid() != 0; /* ...finally, disallow root */
+ return result;
}
+
+NCURSES_EXPORT(int)
+_nc_safe_open3(const char *path, int flags, mode_t mode)
+{
+ int result = -1;
+#if HAVE_SETFSUID
+ lower_privileges();
+ result = open(path, flags, mode);
+ resume_elevation();
+#else
+ if (!is_elevated() || (flags & O_RDONLY)) {
+ result = open(path, flags, mode);
+ }
#endif
+ return result;
+}
+#endif /* USE_ROOT_ENVIRON */
projects / ncurses.git / blobdiff