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-rw-r--r--sysdeps/posix/euidaccess.c201
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diff --git a/sysdeps/posix/euidaccess.c b/sysdeps/posix/euidaccess.c
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+/* euidaccess -- check if effective user id can access file
+   Copyright (C) 1990, 1991, 1995 Free Software Foundation, Inc.
+
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/* Written by David MacKenzie and Torbjorn Granlund.
+   Adapted for GNU C library by Roland McGrath.  */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.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 */
+
+#if defined (HAVE_UNISTD_H) || defined (_LIBC)
+#include <unistd.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;
+#endif
+
+#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
+#endif
+
+
+#ifdef _LIBC
+
+#define group_member __group_member
+
+#else
+
+/* 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;
+
+/* The user's effective group id. */
+static gid_t egid;
+
+/* Nonzero if UID, GID, EUID, and EGID have valid values. */
+static int have_ids = 0;
+
+#ifdef HAVE_GETGROUPS
+int group_member ();
+#else
+#define group_member(gid)	0
+#endif
+
+#endif
+
+
+/* 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. */
+
+int
+euidaccess (path, mode)
+     const char *path;
+     int mode;
+{
+  struct stat stats;
+  int granted;
+
+#ifdef	_LIBC
+  uid_t uid = getuid (), euid = geteuid ();
+  gid_t gid = getgid (), egid = getegid ();
+#else
+  if (have_ids == 0)
+    {
+      have_ids = 1;
+      uid = getuid ();
+      gid = getgid ();
+      euid = geteuid ();
+      egid = getegid ();
+    }
+#endif
+
+  if (uid == euid && gid == egid)
+    /* If we are not set-uid or set-gid, access does the same.  */
+    return access (path, mode);
+
+  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. */
+
+  /* The super-user can read and write any file, and execute any file
+     that anyone can execute. */
+  if (euid == 0 && ((mode & X_OK) == 0
+		    || (stats.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
+    return 0;
+
+  if (euid == stats.st_uid)
+    granted = (unsigned) (stats.st_mode & (mode << 6)) >> 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)
+    return 0;
+  errno = EACCESS;
+  return -1;
+}
+
+#ifdef TEST
+#include <stdio.h>
+#include <errno.h>
+#include "error.h"
+
+char *program_name;
+
+int
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  char *file;
+  int mode;
+  int err;
+
+  program_name = argv[0];
+  if (argc < 3)
+    abort ();
+  file = argv[1];
+  mode = atoi (argv[2]);
+
+  err = euidaccess (file, mode);
+  printf ("%d\n", err);
+  if (err != 0)
+    error (0, errno, "%s", file);
+  exit (0);
+}
+#endif