ping命令

package main

import (
   "bytes"
   "database/sql"
   "errors"
   "fmt"
   _ "github.com/go-sql-driver/mysql"
   "net"
   "os"
   "strings"
   "time"
)

func mainPing2() {
   const DBDriverName = "mysql"
   const DBDataSourceName = "root:qazwsx@tcp(10.128.1.55:3306)/noc"
   db, e := sql.Open(DBDriverName, DBDataSourceName)
   if e != nil {
      panic(e)
   }
   e = db.Ping()
   if e != nil {
      panic(e)
   }
   // close database after all work is done
   defer db.Close()

   ips := []string{"10.128.1.194", "10.128.1.57"}
   s := "SELECT ipaddr,lastconntime FROM  devicestatus WHERE ipaddr IN ("" + strings.Join(ips, "","") + "");"
   m := map[string]map[string]string{}
   now := func() string {
      return fmt.Sprint(time.Now())
   }
   f := func() {
      rows, e := db.Query(s)
      if e != nil {
         panic(e)
      }
      for rows.Next() {
         var ipaddr, lastconntime string
         e = rows.Scan(&ipaddr, &lastconntime)
         if m[ipaddr] == nil {
            m[ipaddr] = map[string]string{}
         }
         m[ipaddr][now()] = strings.Join([]string{lastconntime}, ",")
      }
   }

   for i := 0; i < 8; i++ {
      f()
      time.Sleep(60 * time.Second)
   }
   for k, v := range m {
      for k1, v1 := range v {
         fmt.Println(k, k1, v1)
      }
   }
}

// Copyright 2009 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// taken from http://golang.org/src/pkg/net/ipraw_test.go

const (
   icmpv4EchoRequest = 8
   icmpv4EchoReply   = 0
   icmpv6EchoRequest = 128
   icmpv6EchoReply   = 129
)

type icmpMessage struct {
   Type     int             // type
   Code     int             // code
   Checksum int             // checksum
   Body     icmpMessageBody // body
}

type icmpMessageBody interface {
   Len() int
   Marshal() ([]byte, error)
}

// Marshal returns the binary enconding of the ICMP echo request or
// reply message m.
func (m *icmpMessage) Marshal() ([]byte, error) {
   b := []byte{byte(m.Type), byte(m.Code), 0, 0}
   if m.Body != nil && m.Body.Len() != 0 {
      mb, err := m.Body.Marshal()
      if err != nil {
         return nil, err
      }
      b = append(b, mb...)
   }
   switch m.Type {
   case icmpv6EchoRequest, icmpv6EchoReply:
      return b, nil
   }
   csumcv := len(b) - 1 // checksum coverage
   s := uint32(0)
   for i := 0; i < csumcv; i += 2 {
      s += uint32(b[i+1])<<8 | uint32(b[i])
   }
   if csumcv&1 == 0 {
      s += uint32(b[csumcv])
   }
   s = s>>16 + s&0xffff
   s = s + s>>16
   // Place checksum back in header; using ^= avoids the
   // assumption the checksum bytes are zero.
   b[2] ^= byte(^s & 0xff)
   b[3] ^= byte(^s >> 8)
   return b, nil
}

// parseICMPMessage parses b as an ICMP message.
func parseICMPMessage(b []byte) (*icmpMessage, error) {
   msglen := len(b)
   if msglen < 4 {
      return nil, errors.New("message too short")
   }
   m := &icmpMessage{Type: int(b[0]), Code: int(b[1]), Checksum: int(b[2])<<8 | int(b[3])}
   if msglen > 4 {
      var err error
      switch m.Type {
      case icmpv4EchoRequest, icmpv4EchoReply, icmpv6EchoRequest, icmpv6EchoReply:
         m.Body, err = parseICMPEcho(b[4:])
         if err != nil {
            return nil, err
         }
      }
   }
   return m, nil
}

// imcpEcho represenets an ICMP echo request or reply message body.
type icmpEcho struct {
   ID   int    // identifier
   Seq  int    // sequence number
   Data []byte // data
}

func (p *icmpEcho) Len() int {
   if p == nil {
      return 0
   }
   return 4 + len(p.Data)
}

// Marshal returns the binary enconding of the ICMP echo request or
// reply message body p.
func (p *icmpEcho) Marshal() ([]byte, error) {
   b := make([]byte, 4+len(p.Data))
   b[0], b[1] = byte(p.ID>>8), byte(p.ID&0xff)
   b[2], b[3] = byte(p.Seq>>8), byte(p.Seq&0xff)
   copy(b[4:], p.Data)
   return b, nil
}

// parseICMPEcho parses b as an ICMP echo request or reply message body.
func parseICMPEcho(b []byte) (*icmpEcho, error) {
   bodylen := len(b)
   p := &icmpEcho{ID: int(b[0])<<8 | int(b[1]), Seq: int(b[2])<<8 | int(b[3])}
   if bodylen > 4 {
      p.Data = make([]byte, bodylen-4)
      copy(p.Data, b[4:])
   }
   return p, nil
}

func Ping(address string, timeout int) (alive bool) {
   err := Pinger(address, timeout)
   alive = err == nil
   return
}

func Pinger(address string, timeout int) (err error) {
   c, err := net.Dial("ip4:icmp", address)
   if err != nil {
      return
   }
   c.SetDeadline(time.Now().Add(time.Duration(timeout) * time.Second))
   defer c.Close()

   typ := icmpv4EchoRequest
   xid, xseq := os.Getpid()&0xffff, 1
   wb, err := (&icmpMessage{
      Type: typ, Code: 0,
      Body: &icmpEcho{
         ID: xid, Seq: xseq,
         Data: bytes.Repeat([]byte("Go Go Gadget Ping!!!"), 3),
      },
   }).Marshal()
   if err != nil {
      return
   }
   if _, err = c.Write(wb); err != nil {
      return
   }
   var m *icmpMessage
   rb := make([]byte, 20+len(wb))
   for {
      if _, err = c.Read(rb); err != nil {
         return
      }
      rb = ipv4Payload(rb)
      if m, err = parseICMPMessage(rb); err != nil {
         return
      }
      switch m.Type {
      case icmpv4EchoRequest, icmpv6EchoRequest:
         continue
      }
      break
   }
   return
}

func ipv4Payload(b []byte) []byte {
   if len(b) < 20 {
      return b
   }
   hdrlen := int(b[0]&0x0f) << 2
   return b[hdrlen:]
}

golang实现ping命令 - 云+社区 - 腾讯云 https://cloud.tencent.com/developer/article/1071047