X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Feuidaccess.c;h=f73438e6f4787124b532911128a3ce43114a2661;hb=533101a268dc5015a140ff4695d8eeb04fbe57b6;hp=598b875225575fd6f3b395915046e48280801543;hpb=5a79e1f048bd5ad328af146c6002baad87fd4f25;p=gnulib.git

diff --git a/lib/euidaccess.c b/lib/euidaccess.c
index 598b87522..f73438e6f 100644
--- a/lib/euidaccess.c
+++ b/lib/euidaccess.c
@@ -1,10 +1,14 @@
 /* euidaccess -- check if effective user id can access file
-   Copyright (C) 1990, 1991 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1990-1991, 1995, 1998, 2000, 2003-2006, 2008-2013 Free
+   Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,189 +16,191 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-/* Written by David MacKenzie and Torbjorn Granlund. */
+/* Written by David MacKenzie and Torbjorn Granlund.
+   Adapted for GNU C library by Roland McGrath.  */
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
+#ifndef _LIBC
+# include <config.h>
 #endif
 
+#include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
-#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 */
+#include "root-uid.h"
 
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
+#if HAVE_LIBGEN_H
+# include <libgen.h>
 #endif
 
-#ifdef _POSIX_VERSION
-#include <limits.h>
-#if !defined(NGROUPS_MAX) || NGROUPS_MAX < 1
-#undef NGROUPS_MAX
-#define NGROUPS_MAX sysconf (_SC_NGROUPS_MAX)
-#endif /* NGROUPS_MAX */
-
-#else /* not _POSIX_VERSION */
-uid_t getuid ();
-gid_t getgid ();
-uid_t geteuid ();
-gid_t getegid ();
-#include <sys/param.h>
-#if !defined(NGROUPS_MAX) && defined(NGROUPS)
-#define NGROUPS_MAX NGROUPS
-#endif /* not NGROUPS_MAX and NGROUPS */
-#endif /* not POSIX_VERSION */
-
 #include <errno.h>
-#ifndef errno
-extern int errno;
+#ifndef __set_errno
+# define __set_errno(val) errno = (val)
 #endif
 
-#if defined(EACCES) && !defined(EACCESS)
-#define EACCESS EACCES
+#if defined EACCES && !defined EACCESS
+# define EACCESS EACCES
 #endif
 
 #ifndef F_OK
-#define F_OK 0
-#define X_OK 1
-#define W_OK 2
-#define R_OK 4
+# define F_OK 0
+# define X_OK 1
+# define W_OK 2
+# define R_OK 4
 #endif
 
-#include "safe-stat.h"
-
-/* The user's real user id. */
-static uid_t uid;
-
-/* The user's real group id. */
-static gid_t gid;
 
-/* The user's effective user id. */
-static uid_t euid;
+#ifdef _LIBC
 
-/* The user's effective group id. */
-static gid_t egid;
+# 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
 
-int group_member ();
-
-/* Nonzero if UID, GID, EUID, and EGID have valid values. */
-static int have_ids = 0;
+#endif
 
-/* Like euidaccess, except that a pointer to a filled-in stat structure
-   describing the file is provided instead of a filename.
-   Because this function is almost guaranteed to fail on systems that
-   use ACLs, a third argument *PATH may be used.  If it is non-NULL,
-   it is assumed to be the name of the file corresponding to STATP.
-   Then, if the user is not running set-uid or set-gid, use access
-   instead of attempting a manual and non-portable comparison.  */
+/* Return 0 if the user has permission of type MODE on FILE;
+   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 always check for read-only
+   file system, text busy, etc.  */
 
 int
-eaccess_stat (statp, mode, path)
-     const struct stat *statp;
-     int mode;
-     const char *path;
+euidaccess (const char *file, int mode)
 {
-  int granted;
+#if HAVE_FACCESSAT                   /* glibc, AIX 7, Solaris 11, Cygwin 1.7 */
+  return faccessat (AT_FDCWD, file, mode, AT_EACCESS);
+#elif defined EFF_ONLY_OK               /* IRIX, OSF/1, Interix */
+  return access (file, mode | EFF_ONLY_OK);
+#elif defined ACC_SELF                  /* AIX */
+  return accessx (file, mode, ACC_SELF);
+#elif HAVE_EACCESS                      /* FreeBSD */
+  return eaccess (file, mode);
+#else       /* Mac OS X, NetBSD, OpenBSD, HP-UX, Solaris, Cygwin, mingw, BeOS */
+
+  uid_t uid = getuid ();
+  gid_t gid = getgid ();
+  uid_t euid = geteuid ();
+  gid_t egid = getegid ();
+  struct stat stats;
 
-  mode &= (X_OK | W_OK | R_OK);	/* Clear any bogus bits. */
+# if HAVE_DECL_SETREGID && PREFER_NONREENTRANT_EUIDACCESS
 
-  if (mode == F_OK)
-    return 0;			/* The file exists. */
+  /* 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 (have_ids == 0)
+  if (mode == F_OK)
+    return stat (file, &stats);
+  else
     {
-      have_ids = 1;
-      uid = getuid ();
-      gid = getgid ();
-      euid = geteuid ();
-      egid = getegid ();
-    }
+      int result;
+      int saved_errno;
 
-  if (path && uid == euid && gid == egid)
-    {
-      return access (path, mode);
-    }
+      if (uid != euid)
+        setreuid (euid, uid);
+      if (gid != egid)
+        setregid (egid, gid);
 
-  /* The super-user can read and write any file, and execute any file
-     that anyone can execute. */
-  if (euid == 0 && ((mode & X_OK) == 0
-		    || (statp->st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
-    return 0;
+      result = access (file, mode);
+      saved_errno = errno;
 
-  if (euid == statp->st_uid)
-    granted = (unsigned) (statp->st_mode & (mode << 6)) >> 6;
-  else if (egid == statp->st_gid
-#ifdef HAVE_GETGROUPS
-	   || group_member (statp->st_gid)
-#endif
-	   )
-    granted = (unsigned) (statp->st_mode & (mode << 3)) >> 3;
-  else
-    granted = (statp->st_mode & mode);
-  if (granted == mode)
-    return 0;
-  errno = EACCESS;
-  return -1;
-}
+      /* Restore them.  */
+      if (uid != euid)
+        setreuid (uid, euid);
+      if (gid != egid)
+        setregid (gid, egid);
 
-/* Return 0 if the user has permission of type MODE on file PATH;
-   otherwise, return -1 and set `errno' to EACCESS.
-   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. */
+      errno = saved_errno;
+      return result;
+    }
 
-int
-euidaccess (path, mode)
-     const char *path;
-     int mode;
-{
-  struct stat stats;
+# else
 
-  if (have_ids == 0)
-    {
-      have_ids = 1;
-      uid = getuid ();
-      gid = getgid ();
-      euid = geteuid ();
-      egid = getegid ();
-    }
+  /* 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)
-    {
-      return access (path, mode);
-    }
+    /* If we are not set-uid or set-gid, access does the same.  */
+    return access (file, mode);
 
-  if (stat (path, &stats))
+  if (stat (file, &stats) != 0)
     return -1;
 
-  return eaccess_stat (&stats, mode, path);
-}
+  /* The super-user can read and write any file, and execute any file
+     that anyone can execute.  */
+  if (euid == ROOT_UID
+      && ((mode & X_OK) == 0
+          || (stats.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
+    return 0;
 
-#ifdef TEST
-#include <stdio.h>
-#include <errno.h>
+  /* 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 >>= 6;
+  else if (egid == stats.st_gid || group_member (stats.st_gid))
+    granted >>= 3;
+
+  if ((mode & ~granted) == 0)
+    return 0;
+  __set_errno (EACCESS);
+  return -1;
 
-void error ();
+# endif
+#endif
+}
+#undef euidaccess
+#ifdef weak_alias
+weak_alias (__euidaccess, euidaccess)
+#endif
+
+#ifdef TEST
+# include <error.h>
+# include <stdio.h>
+# include <stdlib.h>
 
 char *program_name;
 
 int
-main (argc, argv)
-     int argc;
-     char **argv;
+main (int argc, char **argv)
 {
   char *file;
   int mode;