package conn import ( "bytes" "net" "os" "time" ) const ( ICMP_ECHO_REQUEST = 8 ICMP_ECHO_REPLY = 0 ) // Ping Request func makePingRequest(id, seq, pktlen int, filler []byte) []byte { p := make([]byte, pktlen) copy(p[8:], bytes.Repeat(filler, (pktlen-8)/len(filler)+1)) p[0] = ICMP_ECHO_REQUEST // type p[1] = 0 // code p[2] = 0 // cksum p[3] = 0 // cksum p[4] = uint8(id >> 8) // id p[5] = uint8(id & 0xff) // id p[6] = uint8(seq >> 8) // sequence p[7] = uint8(seq & 0xff) // sequence // calculate icmp checksum cklen := len(p) s := uint32(0) for i := 0; i < (cklen - 1); i += 2 { s += uint32(p[i+1])<<8 | uint32(p[i]) } if cklen&1 == 1 { s += uint32(p[cklen-1]) } s = (s >> 16) + (s & 0xffff) s = s + (s >> 16) // place checksum back in header; using ^= avoids the // assumption the checksum bytes are zero p[2] ^= uint8(^s & 0xff) p[3] ^= uint8(^s >> 8) return p } func parsePingReply(p []byte) (id, seq int) { id = int(p[4])<<8 | int(p[5]) seq = int(p[6])<<8 | int(p[7]) return } // Ping func Ping(addr string, i int) bool { // *IPAddr raddr, e := net.ResolveIPAddr("ip4", addr) if e != nil { return false } // *IPConn ipconn, ee := net.DialIP("ip4:icmp", nil, raddr) if ee != nil { return false } // 保证连接正常关闭 defer ipconn.Close() // PID sendid := os.Getpid() & 0xffff sendseq := 1 pingpktlen := 64 for { sendpkt := makePingRequest(sendid, sendseq, pingpktlen, []byte("Go Ping")) // 发送请求 n, err := ipconn.WriteToIP(sendpkt, raddr) if err != nil || n != pingpktlen { break } // 超时 ipconn.SetDeadline(time.Now().Add(5 * time.Second)) // 返回数据 resp := make([]byte, 1024) for { // 读取返回 _, _, err := ipconn.ReadFrom(resp) if err != nil { break } // 判断状态 if resp[0] != ICMP_ECHO_REPLY { continue } // 判断状态 rcvid, rcvseq := parsePingReply(resp) if rcvid != sendid || rcvseq != sendseq { break } // 成功返回 return true } // 执行次数内未成功返回 if i == sendseq { break } // 计数器 sendseq++ } // 失败返回 return false } 有疑问加站长微信联系（非本文作者）
