* ntea.cc (read_ea): Try to open file first to have more sensible

	error codes.  Always refuse non "user." EAs for Linux compatibility
	and return EOPNOTSUPP.  Fix handling of empty (== non-existant) EAs.
	Always prepend "user." prefix to EA names.
	(write_ea): Try to open file first to have more sensible error codes.
	Always refuse non "user." EAs for Linux compatibility and return
	EOPNOTSUPP.  Delay skipping "user." prefix until after potential call
	to read_ea.

1 files changed, 54 insertions, 35 deletions

diff --git a/winsup/cygwin/ntea.cc b/winsup/cygwin/ntea.cc
index 744076ef7..7e3240abc 100644
--- a/winsup/cygwin/ntea.cc
+++ b/winsup/cygwin/ntea.cc
@@ -56,22 +56,34 @@ read_ea (HANDLE hdl, path_conv &pc, const char *name, char *value, size_t size)
   debug_printf ("read_ea (%S, %s, %p, %lu)",
 		attr.ObjectName, name, value, size);
 
+  /* Early open if handle is NULL.  This allows to return error codes like
+     ENOENT before we actually check for the correctness of the EA name and
+     stuff like that. */
+  if (!hdl)
+    {
+      status = NtOpenFile (&h, READ_CONTROL | FILE_READ_EA, &attr, &io,
+			   FILE_SHARE_VALID_FLAGS, FILE_OPEN_FOR_BACKUP_INTENT);
+      if (!NT_SUCCESS (status))
+	{
+	  __seterrno_from_nt_status (status);
+	  goto out;
+	}
+      hdl = NULL;
+    }
+
   fea = (PFILE_FULL_EA_INFORMATION) alloca (EA_BUFSIZ);
 
   if (name)
     {
       size_t nlen;
 
-      /* Samba hides the user namespace from Windows clients.  If we try to
-	 retrieve a user namespace item, we remove the leading namespace from
-	 the name, otherwise the search fails. */
-      if (!pc.fs_is_samba ())
-	/* nothing to do */;
-      else if (ascii_strncasematch (name, "user.", 5))
+      /* For compatibility with Linux, we only allow user xattrs and
+         return EOPNOTSUPP otherwise. */
+      if (ascii_strncasematch (name, "user.", 5))
 	name += 5;
       else
 	{
-	  set_errno (ENOATTR);
+	  set_errno (EOPNOTSUPP);
 	  goto out;
 	}
 
@@ -117,6 +129,16 @@ read_ea (HANDLE hdl, path_conv &pc, const char *name, char *value, size_t size)
     }
   if (name)
     {
+      /* Another weird behaviour of ZwQueryEaFile.  If you ask for a
+	 specific EA which is not present in the file's EA list, you don't
+	 get a useful error code like STATUS_NONEXISTENT_EA_ENTRY.  Rather
+	 ZwQueryEaFile returns success with the entry's EaValueLength
+	 set to 0. */
+      if (!fea->EaValueLength)
+	{
+	  set_errno (ENOATTR);
+	  goto out;
+	}
       if (size > 0)
 	{
 	  if (size < fea->EaValueLength)
@@ -124,19 +146,8 @@ read_ea (HANDLE hdl, path_conv &pc, const char *name, char *value, size_t size)
 	      set_errno (ERANGE);
 	      goto out;
 	    }
-	  /* Another weird behaviour of ZwQueryEaFile.  If you ask for a
-	     specific EA which is not present in the file's EA list, you don't
-	     get a useful error code like STATUS_NONEXISTENT_EA_ENTRY.  Rather
-	     ZwQueryEaFile returns success with the entry's EaValueLength
-	     set to 0. */
-	  if (!fea->EaValueLength)
-	    {
-	      set_errno (ENOATTR);
-	      goto out;
-	    }
-	  else
-	    memcpy (value, fea->EaName + fea->EaNameLength + 1,
-		    fea->EaValueLength);
+	  memcpy (value, fea->EaName + fea->EaNameLength + 1,
+		  fea->EaValueLength);
 	}
       ret = fea->EaValueLength;
     }
@@ -158,8 +169,7 @@ read_ea (HANDLE hdl, path_conv &pc, const char *name, char *value, size_t size)
 		 it in EA listings to keep tools like attr/getfattr/setfattr
 		 happy. */
 	      char tmpbuf[MAX_EA_NAME_LEN * 2], *tp = tmpbuf;
-	      if (pc.fs_is_samba ())
-		tp = stpcpy (tmpbuf, "user.");
+	      tp = stpcpy (tmpbuf, "user.");
 	      stpcpy (tp, fea->EaName);
 	      /* NTFS stores all EA names in uppercase unfortunately.  To keep
 		 compatibility with ext/xfs EA namespaces and accompanying
@@ -210,20 +220,26 @@ write_ea (HANDLE hdl, path_conv &pc, const char *name, const char *value,
   debug_printf ("write_ea (%S, %s, %p, %lu, %d)",
 		attr.ObjectName, name, value, size, flags);
 
-  /* Samba hides the user namespace from Windows clients.  If we get a
-     user namespace item, we remove the leading namespace from the name.
-     This keeps tools like attr/getfattr/setfattr happy.  Otherwise
-     setting the EA fails as if we don't have the permissions. */
-      /* Samba hides the user namespace from Windows clients.  If we try to
-	 retrieve a user namespace item, we remove the leading namespace from
-	 the name, otherwise the search fails. */
-  if (!pc.fs_is_samba ())
-    /* nothing to do */;
-  else if (ascii_strncasematch (name, "user.", 5))
-    name += 5;
-  else
+  /* Early open if handle is NULL.  This allows to return error codes like
+     ENOENT before we actually check for the correctness of the EA name and
+     stuff like that. */
+  if (!hdl)
+    {
+      status = NtOpenFile (&h, READ_CONTROL | FILE_WRITE_EA, &attr, &io,
+			   FILE_SHARE_VALID_FLAGS, FILE_OPEN_FOR_BACKUP_INTENT);
+      if (!NT_SUCCESS (status))
+	{
+	  __seterrno_from_nt_status (status);
+	  goto out;
+	}
+      hdl = NULL;
+    }
+
+  /* For compatibility with Linux, we only allow user xattrs and
+     return EOPNOTSUPP otherwise. */
+  if (!ascii_strncasematch (name, "user.", 5))
     {
-      set_errno (ENOATTR);
+      set_errno (EOPNOTSUPP);
       goto out;
     }
 
@@ -249,6 +265,9 @@ write_ea (HANDLE hdl, path_conv &pc, const char *name, const char *value,
 	goto out;
     }
 
+  /* Skip "user." prefix. */
+  name += 5;
+
   if ((nlen = strlen (name)) >= MAX_EA_NAME_LEN)
     {
       set_errno (EINVAL);