| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package udp |
| |
| import ( |
| "fmt" |
| "net" |
| |
| log "github.com/Sirupsen/logrus" |
| ) |
| |
| const MAX_PACKET_SIZE = 2048 |
| |
| func Listen(peerString string, dispatchCb func(data []byte)) ( |
| *net.UDPConn, *net.UDPAddr, error) { |
| |
| addr, err := net.ResolveUDPAddr("udp", peerString) |
| if err != nil { |
| return nil, nil, |
| fmt.Errorf("Failure resolving name for UDP session: %s", |
| err.Error()) |
| } |
| |
| conn, err := net.ListenUDP("udp", nil) |
| if err != nil { |
| return nil, nil, |
| fmt.Errorf("Failed to listen for UDP responses: %s", err.Error()) |
| } |
| |
| go func() { |
| data := make([]byte, MAX_PACKET_SIZE) |
| |
| for { |
| nr, srcAddr, err := conn.ReadFromUDP(data) |
| if err != nil { |
| // Connection closed or read error. |
| return |
| } |
| |
| log.Debugf("Received message from %v %d", srcAddr, nr) |
| dispatchCb(data[0:nr]) |
| } |
| }() |
| |
| return conn, addr, nil |
| } |