package main
import (
"flag"
"fmt"
"net"
"os"
"strconv"
"time"
)
func main() {
var count int
var timeout int64
var size int
var neverstop bool
flag.Int64Var(&timeout, "w", 1000, "等待每次回复的超时时间(毫秒)。")
flag.IntVar(&count, "n", 4, "要发送的回显请求数。")
flag.IntVar(&size, "l", 32, "要发送缓冲区大小。")
flag.BoolVar(&neverstop, "t", true, "Ping 指定的主机，直到停止。")
flag.Parse()
args := flag.Args()
if len(args) < 1 {
fmt.Println("Usage: ", os.Args[0], "host")
flag.PrintDefaults()
flag.Usage()
os.Exit(1)
}
ch := make(chan int)
argsmap := map[string]interface{}{}
argsmap["w"] = timeout
argsmap["n"] = count
argsmap["l"] = size
argsmap["t"] = neverstop
for _, host := range args {
go ping(host, ch, argsmap)
}
for i := 0; i < len(args); i++ {
<-ch
}
os.Exit(0)
}
func ping(host string, c chan int, args map[string]interface{}) {
var count int
var size int
var timeout int64
var neverstop bool
count = args["n"].(int)
size = args["l"].(int)
timeout = args["w"].(int64)
neverstop = args["t"].(bool)
cname, _ := net.LookupCNAME(host)
starttime := time.Now()
conn, err := net.DialTimeout("ip4:icmp", host, time.Duration(timeout*1000*1000))
ip := conn.RemoteAddr()
fmt.Println("正在 Ping " + cname + " [" + ip.String() + "] 具有 32 字节的数据:")
var seq int16 = 1
id0, id1 := genidentifier(host)
const ECHO_REQUEST_HEAD_LEN = 8
sendN := 0
recvN := 0
lostN := 0
shortT := -1
longT := -1
sumT := 0
for count > 0 || neverstop {
sendN++
var msg []byte = make([]byte, size+ECHO_REQUEST_HEAD_LEN)
msg[0] = 8 // echo
msg[1] = 0 // code 0
msg[2] = 0 // checksum
msg[3] = 0 // checksum
msg[4], msg[5] = id0, id1 //identifier[0] identifier[1]
msg[6], msg[7] = gensequence(seq) //sequence[0], sequence[1]
length := size + ECHO_REQUEST_HEAD_LEN
check := checkSum(msg[0:length])
msg[2] = byte(check >> 8)
msg[3] = byte(check & 255)
conn, err = net.DialTimeout("ip:icmp", host, time.Duration(timeout*1000*1000))
checkError(err)
starttime = time.Now()
conn.SetDeadline(starttime.Add(time.Duration(timeout * 1000 * 1000)))
_, err = conn.Write(msg[0:length])
const ECHO_REPLY_HEAD_LEN = 20
var receive []byte = make([]byte, ECHO_REPLY_HEAD_LEN+length)
n, err := conn.Read(receive)
_ = n
var endduration int = int(int64(time.Since(starttime)) / (1000 * 1000))
sumT += endduration
time.Sleep(1000 * 1000 * 1000)
if err != nil || receive[ECHO_REPLY_HEAD_LEN+4] != msg[4] || receive[ECHO_REPLY_HEAD_LEN+5] != msg[5] || receive[ECHO_REPLY_HEAD_LEN+6] != msg[6] || receive[ECHO_REPLY_HEAD_LEN+7] != msg[7] || endduration >= int(timeout) || receive[ECHO_REPLY_HEAD_LEN] == 11 {
lostN++
fmt.Println("对 " + cname + "[" + ip.String() + "]" + " 的请求超时。")
} else {
if shortT == -1 {
shortT = endduration
} else if shortT > endduration {
shortT = endduration
}
if longT == -1 {
longT = endduration
} else if longT < endduration {
longT = endduration
}
recvN++
ttl := int(receive[8])
// fmt.Println(ttl)
fmt.Println("来自 " + cname + "[" + ip.String() + "]" + " 的回复: 字节=32 时间=" + strconv.Itoa(endduration) + "ms TTL=" + strconv.Itoa(ttl))
}
seq++
count--
}
stat(ip.String(), sendN, lostN, recvN, shortT, longT, sumT)
c <- 1
}
func checkSum(msg []byte) uint16 {
sum := 0
length := len(msg)
for i := 0; i < length-1; i += 2 {
sum += int(msg[i])*256 + int(msg[i+1])
}
if length%2 == 1 {
sum += int(msg[length-1]) * 256 // notice here, why *256?
}
sum = (sum >> 16) + (sum & 0xffff)
sum += (sum >> 16)
var answer uint16 = uint16(^sum)
return answer
}
func checkError(err error) {
if err != nil {
fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
os.Exit(1)
}
}
func gensequence(v int16) (byte, byte) {
ret1 := byte(v >> 8)
ret2 := byte(v & 255)
return ret1, ret2
}
func genidentifier(host string) (byte, byte) {
return host[0], host[1]
}
func stat(ip string, sendN int, lostN int, recvN int, shortT int, longT int, sumT int) {
fmt.Println()
fmt.Println(ip, " 的 Ping 统计信息:")
fmt.Printf(" 数据包: 已发送 = %d，已接收 = %d，丢失 = %d (%d%% 丢失)，\n", sendN, recvN, lostN, int(lostN*100/sendN))
fmt.Println("往返行程的估计时间(以毫秒为单位):")
if recvN != 0 {
fmt.Printf(" 最短 = %dms，最长 = %dms，平均 = %dms\n", shortT, longT, sumT/sendN)
}
}
