core/setxattr: prevent users from setting glusterfs xattrs

* Each xlator prevents the user from setting glusterfs-internal
xattrs like trusted.gfid by handling it in respective setxattr
functions. The speacial case of trusted.gfid is handled in
fuse (Not in posix because posix_setxattr is used to set gfid).

* For xlators which did not define setxattr and/or fsetxattr,
the functions have been implemented with appropriate checks.

xlator         |     fops-added
_______________|__________________________
               |
1. afr         |     fsetxattr
2. stripe      |     setxatrr and fsetxattr
3. quota       |     setxattr and fsetxattr

Change-Id: Ib62abb7067415b23a708002f884d30e8866fbf48
BUG: 765487
Signed-off-by: Rajesh Amaravathi <rajesh@redhat.com>
Reviewed-on: http://review.gluster.com/685
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amar@gluster.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 32c80075356..8c1cd8f7568 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -2641,6 +2641,12 @@ fuse_setxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
                 return;
         }
 
+        if (!strcmp (GFID_XATTR_KEY, name)) {
+                send_fuse_err (this, finh, EPERM);
+                GF_FREE (finh);
+                return;
+        }
+
         GET_STATE (this, finh, state);
         state->size = fsi->size;
         ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);