1 package main 2  3 import ( 4     "fmt" 5     "net" 6     "os" 7     "io" 8     "bytes" 9 )10 11 func main() {12     if len(os.Args) != 2 {13         fmt.Println("Usage : ", os.Args[0], "host")14         os.Exit(0)15     }16     service := os.Args[1]17 18     conn, err := net.Dial("ip4:icmp", service)19     checkError(err)20 21     var msg [512]byte22     msg[0] = 823     msg[1] = 024     msg[2] = 025     msg[3] = 026     msg[4] = 027     msg[5] = 1328     msg[6] = 029     msg[7] = 3730     len := 831     check := checkSum(msg[0:len])32     msg[2] = byte(check >> 8)33     msg[3] = byte(check & 255)34 35     _, err = conn.Write(msg[0:len])36     checkError(err)37 38     fmt.Println("Got response")39     if msg[5] == 13 {40         fmt.Println("Identifier matches")41     }42     if msg[7] == 37 {43         fmt.Println("Sequence matches")44     }45 46     os.Exit(0)47 }48 49 func checkSum(msg []byte) uint16 {50     sum := 051 52     for n := 1; n < len(msg) - 1; n += 2 {53         sum += int(msg[n]) * 256 + int(msg[n+1])54     }55     sum = (sum >> 16 ) + (sum & 0xffff)56     sum += (sum >> 16)57     var answer uint16 = uint16(^sum)58     return answer59 }60 61 func checkError(err error) {62     if err != nil {63         fmt.Fprintf(os.Stderr, "Fatal error : %s\n", err.Error())64         os.Exit(1)65     }66 }67 68 func readFully(conn net.Conn) ([]byte, error) {69     defer conn.Close()70 71     result := bytes.NewBuffer(nil)72     var buf [512]byte73     for {74         n, err := conn.Read(buf[0:])75         result.Write(buf[0:n])76         if err != nil {77             if err == io.EOF {78                 break79             }80             return nil, err81         }82     }83 84     return result.Bytes(), nil85 }

$ go build icmptest.go $ lsicmptest  icmptest.go$ ./icmptest www.baidu.comGot responseIdentifier matchesSequence matches