make getxattr fail with ERANGE if reply is bigger than what was requested

Edited by avati: make the function signature of fuse_xattr_reply_buf() use 'const char *value' instead of 'char *value'

Signed-off-by: Anand V. Avati <avati@amp.gluster.com>

1 files changed, 25 insertions, 31 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 297744cd61e..2a5c0cc29b8 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -1919,6 +1919,24 @@ fuse_setxattr (fuse_req_t req, fuse_ino_t ino, const char *name,
         return;
 }
 
+static void
+fuse_reply_xattr_buf(fuse_state_t *state, fuse_req_t req, const char *value,
+                     size_t ret)
+{
+        /* linux kernel limits the size of xattr value to 64k */
+        if (ret > GLUSTERFS_XATTR_LEN_MAX)
+                fuse_reply_err (req, E2BIG);
+        else if (state->size) {
+                /* if callback for getxattr and asks for value */
+                if (ret > state->size)
+                        /* reply would be bigger than
+                         * what was asked by kernel */
+                        fuse_reply_err (req, ERANGE);
+                else
+                        fuse_reply_buf (req, value, ret);
+        } else
+                fuse_reply_xattr (req, ret);
+}
 
 static int
 fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
@@ -1981,16 +1999,8 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                 ret = value_data->len; /* Don't return the value for '\0' */
                                 value = value_data->data;
         
-                                /* linux kernel limits the size of xattr value to 64k */
-                                if (ret > GLUSTERFS_XATTR_LEN_MAX) {
-                                        fuse_reply_err (req, E2BIG);
-                                } else if (state->size) {
-                                        /* if callback for getxattr and asks for value */
-                                        fuse_reply_buf (req, value, ret);
-                                } else {
-                                        /* if callback for getxattr and asks for value length only */
-                                        fuse_reply_xattr (req, ret);
-                                } /* if(ret >...)...else if...else */
+                                fuse_reply_xattr_buf (state, req, value, ret);
+                                /* if(ret >...)...else if...else */
                         }  else if (!strcmp (state->name, "user.glusterfs-booster-volfile")) {
 				if (!priv->volfile) {
 					memset (&st, 0, sizeof (st));
@@ -2011,21 +2021,11 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 					}
 				}
 				
-				if (priv->volfile_size > GLUSTERFS_XATTR_LEN_MAX) {
-					fuse_reply_err (req, E2BIG);
-				} else if (state->size) {
-					/* if callback for getxattr and asks for value */
-					fuse_reply_buf (req, priv->volfile, priv->volfile_size);
-				} else {
-					/* if callback for getxattr and asks for value length only */
-					fuse_reply_xattr (req, priv->volfile_size);
-				} /* if(ret >...)...else if...else */
+				fuse_reply_xattr_buf (state, req, priv->volfile, priv->volfile_size);
+				/* if(ret >...)...else if...else */
 			} else if (!strcmp (state->name, "user.glusterfs-booster-path")) {
-				if (state->size) {
-					fuse_reply_buf (req, state->loc.path, strlen (state->loc.path) + 1);
-				} else {
-					fuse_reply_xattr (req, strlen (state->loc.path) + 1);
-				}
+				fuse_reply_xattr_buf (state, req, state->loc.path,
+				                      strlen(state->loc.path) + 1);
 			} else {
 				fuse_reply_err (req, ENODATA);
 			} /* if(value_data)...else */
@@ -2046,13 +2046,7 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                 len += strlen (trav->key) + 1;
                                 trav = trav->next;
                         } /* while(trav) */
-                        if (state->size) {
-                                /* if callback for listxattr and asks for list of keys */
-                                fuse_reply_buf (req, value, len);
-                        } else {
-                                /* if callback for listxattr and asks for length of keys only */
-                                fuse_reply_xattr (req, len);
-                        } /* if(state->size)...else */
+                        fuse_reply_xattr_buf (state, req, value, len);
 		} /* if(state->name)...else */
         } else {
                 /* if failure - no need to check if listxattr or getxattr */