Add support for REMOVE_BUCKET operation in group

Signed-off-by: Hongliang Liu <[email protected]>

.gitignore

@@ -11,3 +11,4 @@
 
 .idea/
 .vscode/
+vendor

VERSION

@@ -1 +1 @@
-v0.6.7
+v0.6.8

ofctrl/fgraphGroup.go

@@ -109,13 +109,25 @@ func (self *Group) getGroupModMessage(command int) *openflow15.GroupMod {
 		groupMod.Type = openflow15.GT_FF
 	}
 
-	for _, bkt := range self.Buckets {
-		// Add the bucket to group
-		groupMod.AddBucket(*bkt)
+	// OFPGC_REMOVE_BUCKET does not need bucket list.
+	if command != openflow15.OFPGC_REMOVE_BUCKET {
+		for _, bkt := range self.Buckets {
+			// Add the bucket to group
+			groupMod.AddBucket(*bkt)
+		}
 	}
 
 	if command == openflow15.OFPGC_INSERT_BUCKET {
+		// In a request of type OFPGC_INSERT_BUCKET, the command_bucket_id field is used to specify the position in the
+		// current action bucket list to insert new action buckets. Here place the buckets to the end of the current action
+		// bucket list.
 		groupMod.CommandBucketId = openflow15.OFPG_BUCKET_LAST
+	} else if command == openflow15.OFPGC_REMOVE_BUCKET {
+		// In a request of type OFPGC_REMOVE_BUCKET, the CommandBucketId field is used to specify the identifier of the
+		// bucket to remove from current action bucket list.
+		groupMod.CommandBucketId = self.Buckets[0].BucketId
+		// In a request of type OFPGC_REMOVE_BUCKET, bucket list should be empty when removing a bucket.
+		groupMod.Buckets = nil
 	}
 	groupMod.Command = uint16(command)
 	return groupMod