From c5a841743b71a60935edbb8fcacf31643158c322 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 6 Aug 2004 23:44:27 +0000 Subject: [PATCH] [HAVE_LIBGEN_H]: Include , for eaccess on Solaris and SVR4-like systems. (euidaccess): Use HAVE_EACCESS, not HAVE_DECL_EACCESS. [!defined LIBC]: Included group-member.h, stat-macros.h. (S_IXUSR, S_IXGRP, S_IXOTH, S_IROTH, S_IWOTH, S_IXOTH): Remove; now done by stat-macros.h. (NGROUPS_MAX, group_member): Remove; now done by group-member.h. No need to include . (errno): Remove decl; we now assume C89 or better. (access, getuid, getgid, geteuid, getegid, stat) [defined _LIBC]: New macros. (uid, gid, have_ids): Remove these static variables. They weren't accurate for programs that also invoked setreuid etc. (euidaccess) [defined EFF_ONLY_OK || defined ACC_SELF || HAVE_DECL_EACCSS]: Use builtin substitutes. [defined _LIBC]: Ignore __libc_enable_secure; it's not a correct optimization for programs run as root that later invoke setreuid. [no builtin substitutes && HAVE_DECL_SETREGID && PREFER_NONREENTRANT_EUIDACCESS]: Use setreuid+setregid to get the correct answer. [no builtin substitutes && ! (HAVE_DECL_SETREGID && PREFER_NONREENTRANT_EUIDACCESS)]: Don't assume that the stat macros have their historical values, as POSIX doesn't require this. [defined TEST]: Include ; don't include errno.h twice; include rather than "error.h". --- lib/euidaccess.c | 213 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 108 insertions(+), 105 deletions(-) diff --git a/lib/euidaccess.c b/lib/euidaccess.c index 772cf6f1f..d63566c60 100644 --- a/lib/euidaccess.c +++ b/lib/euidaccess.c @@ -1,7 +1,7 @@ /* euidaccess -- check if effective user id can access file - Copyright (C) 1990, 1991, 1995, 1998, 2000, 2003 Free Software - Foundation, Inc. + Copyright (C) 1990, 1991, 1995, 1998, 2000, 2003, 2004 Free + Software Foundation, Inc. This file is part of the GNU C Library. @@ -33,49 +33,27 @@ #include #include -#ifdef S_IEXEC -# ifndef S_IXUSR -# define S_IXUSR S_IEXEC -# endif -# ifndef S_IXGRP -# define S_IXGRP (S_IEXEC >> 3) -# endif -# ifndef S_IXOTH -# define S_IXOTH (S_IEXEC >> 6) -# endif -#endif /* S_IEXEC */ - -#if defined (HAVE_UNISTD_H) || defined (_LIBC) +#if HAVE_UNISTD_H || defined _LIBC # include #endif -#ifdef _POSIX_VERSION -# include -# if !defined(NGROUPS_MAX) || NGROUPS_MAX < 1 -# undef NGROUPS_MAX -# define NGROUPS_MAX sysconf (_SC_NGROUPS_MAX) -# endif /* NGROUPS_MAX */ +#if HAVE_LIBGEN_H +# include +#endif -#else /* not _POSIX_VERSION */ +#ifndef _POSIX_VERSION uid_t getuid (); gid_t getgid (); uid_t geteuid (); gid_t getegid (); -# include -# if !defined(NGROUPS_MAX) && defined(NGROUPS) -# define NGROUPS_MAX NGROUPS -# endif /* not NGROUPS_MAX and NGROUPS */ -#endif /* not POSIX_VERSION */ +#endif #include -#ifndef errno -extern int errno; -#endif #ifndef __set_errno # define __set_errno(val) errno = (val) #endif -#if defined(EACCES) && !defined(EACCESS) +#if defined EACCES && !defined EACCESS # define EACCESS EACCES #endif @@ -86,117 +64,142 @@ extern int errno; # define R_OK 4 #endif -#if !defined (S_IROTH) && defined (R_OK) -# define S_IROTH R_OK -#endif - -#if !defined (S_IWOTH) && defined (W_OK) -# define S_IWOTH W_OK -#endif - -#if !defined (S_IXOTH) && defined (X_OK) -# define S_IXOTH X_OK -#endif #ifdef _LIBC +# define access __access +# define getuid __getuid +# define getgid __getgid +# define geteuid __geteuid +# define getegid __getegid # define group_member __group_member # define euidaccess __euidaccess +# undef stat +# define stat stat64 #else -/* The user's real user id. */ -static uid_t uid; - -/* The user's real group id. */ -static gid_t gid; - -# if HAVE_GETGROUPS -int group_member (); -# else -# define group_member(gid) 0 -# endif +# include "group-member.h" +# include "stat-macros.h" #endif -/* The user's effective user id. */ -static uid_t euid; - -/* The user's effective group id. */ -static gid_t egid; - -/* Nonzero if UID, GID, EUID, and EGID have valid values. */ -static int have_ids; - - /* Return 0 if the user has permission of type MODE on file PATH; - otherwise, return -1 and set `errno' to EACCESS. + otherwise, return -1 and set `errno'. Like access, except that it uses the effective user and group - id's instead of the real ones, and it does not check for read-only - filesystem, text busy, etc. */ + id's instead of the real ones, and it does not always check for read-only + file system, text busy, etc. */ int euidaccess (const char *path, int mode) { +#if defined EFF_ONLY_OK + return access (path, mode | EFF_ONLY_OK); +#elif defined ACC_SELF + return accessx (path, mode, ACC_SELF); +#elif HAVE_EACCESS + return eaccess (path, mode); +#else + + uid_t uid = getuid (); + gid_t gid = getgid (); + uid_t euid = geteuid (); + gid_t egid = getegid (); struct stat stats; - int granted; -#ifdef _LIBC - if (! __libc_enable_secure) - /* If we are not set-uid or set-gid, access does the same. */ - return __access (path, mode); -#else - if (have_ids == 0) +# if HAVE_DECL_SETREGID && PREFER_NONREENTRANT_EUIDACCESS + + /* Define PREFER_NONREENTRANT_EUIDACCESS if you prefer euidaccess to + return the correct result even if this would make it + nonreentrant. Define this only if your entire application is + safe even if the uid or gid might temporarily change. If your + application uses signal handlers or threads it is probably not + safe. */ + + if (mode == F_OK) + return stat (path, &stats); + else { - have_ids = 1; - uid = getuid (); - gid = getgid (); - euid = geteuid (); - egid = getegid (); + int result; + int saved_errno; + + if (uid != euid) + setreuid (euid, uid); + if (gid != egid) + setregid (egid, gid); + + result = access (path, mode); + saved_errno = errno; + + /* Restore them. */ + if (uid != euid) + setreuid (uid, euid); + if (gid != egid) + setregid (gid, egid); + + errno = saved_errno; + return result; } +# else + + /* The following code assumes the traditional Unix model, and is not + correct on systems that have ACLs or the like. However, it's + better than nothing, and it is reentrant. */ + + unsigned int granted; if (uid == euid && gid == egid) /* If we are not set-uid or set-gid, access does the same. */ return access (path, mode); -#endif if (stat (path, &stats)) return -1; - mode &= (X_OK | W_OK | R_OK); /* Clear any bogus bits. */ -#if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH - ?error Oops, portability assumptions incorrect. -#endif - - if (mode == F_OK) - return 0; /* The file exists. */ - -#ifdef _LIBC - /* Now we need the IDs. */ - if (have_ids == 0) - { - have_ids = 1; - euid = __geteuid (); - egid = __getegid (); - } -#endif - /* The super-user can read and write any file, and execute any file - that anyone can execute. */ + that anyone can execute. */ if (euid == 0 && ((mode & X_OK) == 0 || (stats.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)))) return 0; + /* Convert the mode to traditional form, clearing any bogus bits. */ + if (R_OK == 4 && W_OK == 2 && X_OK == 1 && F_OK == 0) + mode &= 7; + else + mode = ((mode & R_OK ? 4 : 0) + + (mode & W_OK ? 2 : 0) + + (mode & X_OK ? 1 : 0)); + + if (mode == 0) + return 0; /* The file exists. */ + + /* Convert the file's permission bits to traditional form. */ + if (S_IRUSR == (4 << 6) && S_IWUSR == (2 << 6) && S_IXUSR == (1 << 6) + && S_IRGRP == (4 << 3) && S_IWGRP == (2 << 3) && S_IXGRP == (1 << 3) + && S_IROTH == (4 << 0) && S_IWOTH == (2 << 0) && S_IXOTH == (1 << 0)) + granted = stats.st_mode; + else + granted = ((stats.st_mode & S_IRUSR ? 4 << 6 : 0) + + (stats.st_mode & S_IWUSR ? 2 << 6 : 0) + + (stats.st_mode & S_IXUSR ? 1 << 6 : 0) + + (stats.st_mode & S_IRGRP ? 4 << 3 : 0) + + (stats.st_mode & S_IWGRP ? 2 << 3 : 0) + + (stats.st_mode & S_IXGRP ? 1 << 3 : 0) + + (stats.st_mode & S_IROTH ? 4 << 0 : 0) + + (stats.st_mode & S_IWOTH ? 2 << 0 : 0) + + (stats.st_mode & S_IXOTH ? 1 << 0 : 0)); + if (euid == stats.st_uid) - granted = (unsigned) (stats.st_mode & (mode << 6)) >> 6; + granted >>= 6; else if (egid == stats.st_gid || group_member (stats.st_gid)) - granted = (unsigned) (stats.st_mode & (mode << 3)) >> 3; - else - granted = (stats.st_mode & mode); - if (granted == mode) + granted >>= 3; + + if ((mode & ~granted) == 0) return 0; __set_errno (EACCESS); return -1; + +# endif +#endif } #undef euidaccess #ifdef weak_alias @@ -204,9 +207,9 @@ weak_alias (__euidaccess, euidaccess) #endif #ifdef TEST +# include # include -# include -# include "error.h" +# include char *program_name; -- 2.11.0