X-Git-Url: http://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=ncurses%2Ftinfo%2Faccess.c;h=a735db26eee600c5fb218c83224de4324aeb75bf;hb=HEAD;hp=6fbe9217604556aec637c048d8d66825c20b1100;hpb=c633e5103a29a38532cf1925257b91cea33fd090;p=ncurses.git diff --git a/ncurses/tinfo/access.c b/ncurses/tinfo/access.c index 6fbe9217..50a5769c 100644 --- a/ncurses/tinfo/access.c +++ b/ncurses/tinfo/access.c @@ -1,5 +1,6 @@ /**************************************************************************** - * Copyright (c) 1998,2000 Free Software Foundation, Inc. * + * Copyright 2019-2021,2023 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 * @@ -27,68 +28,257 @@ ****************************************************************************/ /**************************************************************************** - * Author: Thomas E. Dickey 1998,2000 * + * Author: Thomas E. Dickey * ****************************************************************************/ #include + +#include + +#ifndef USE_ROOT_ACCESS +#if HAVE_SETFSUID +#include +#else +#include +#endif +#endif + +#if HAVE_GETAUXVAL && HAVE_SYS_AUXV_H && defined(__GLIBC__) && (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 19) +#include +#define USE_GETAUXVAL 1 +#else +#define USE_GETAUXVAL 0 +#endif + #include -MODULE_ID("$Id: access.c,v 1.4 2000/10/08 01:25:06 tom Exp $") +MODULE_ID("$Id: access.c,v 1.37 2023/06/24 21:55:09 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 = _nc_basename(path); +#if !MIXEDCASE_FILENAMES || defined(PROG_EXT) + static char *temp; + char *s; + + if ((temp = strdup(result)) != 0) + 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) { - char *result = strrchr(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; } -#ifndef USE_ROOT_ENVIRON +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_GETEUID && HAVE_GETEGID +#define is_posix_elevated() \ + (getuid() != geteuid() \ + || getgid() != getegid()) +#else +#define is_posix_elevated() FALSE +#endif + +#if HAVE_ISSETUGID +#define is_elevated() issetugid() +#elif USE_GETAUXVAL && defined(AT_SECURE) +#define is_elevated() \ + (getauxval(AT_SECURE) \ + ? TRUE \ + : (errno != ENOENT \ + ? FALSE \ + : is_posix_elevated())) +#else +#define is_elevated() is_posix_elevated() +#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 + /* - * Returns true if we allow application to use environment variables that are - * used for searching lists of directories, etc. + * Returns true if not running as root or setuid. We use this check to allow + * applications 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; -#endif - return getuid() != 0; /* ...finally, disallow root */ + int result = TRUE; + +#if HAVE_GETUID && HAVE_GETEUID +#if !defined(USE_SETUID_ENVIRON) + if (is_elevated()) { + result = FALSE; + } +#endif +#if !defined(USE_ROOT_ENVIRON) + if ((getuid() == ROOT_UID) || (geteuid() == ROOT_UID)) { + result = FALSE; + } +#endif +#endif /* HAVE_GETUID && HAVE_GETEUID */ + return result; +} + +#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 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_ACCESS */