p2p/public_ip.go

   1 package p2p
   2
   3 import (
   4         "io/ioutil"
   5         "net"
   6         "net/http"
   7         "strings"
   8         "time"
   9 )
  10
  11 var ipCheckServices = []string{
  12         "http://members.3322.org/dyndns/getip",
  13         "http://ifconfig.me/",
  14         "http://icanhazip.com/",
  15         "http://ifconfig.io/ip",
  16         "http://ident.me/",
  17         "http://whatismyip.akamai.com/",
  18         "http://myip.dnsomatic.com/",
  19         "http://diagnostic.opendns.com/myip",
  20         "http://myexternalip.com/raw",
  21 }
  22
  23 // IPResult is the ip check response
  24 type IPResult struct {
  25         Success bool
  26         IP      string
  27 }
  28
  29 var timeout = time.Duration(5)
  30
  31 // GetIP return the ip of the current host
  32 func GetIP() *IPResult {
  33         resultCh := make(chan *IPResult, 1)
  34         for _, s := range ipCheckServices {
  35                 go ipAddress(s, resultCh)
  36         }
  37
  38         for {
  39                 select {
  40                 case result := <-resultCh:
  41                         return result
  42                 case <-time.After(time.Second * timeout):
  43                         return &IPResult{false, ""}
  44                 }
  45         }
  46 }
  47
  48 func ipAddress(service string, done chan<- *IPResult) {
  49         client := http.Client{Timeout: time.Duration(timeout * time.Second)}
  50         resp, err := client.Get(service)
  51         if err != nil {
  52                 return
  53         }
  54
  55         defer resp.Body.Close()
  56         data, err := ioutil.ReadAll(resp.Body)
  57         if err != nil {
  58                 return
  59         }
  60
  61         address := strings.TrimSpace(string(data))
  62         if ip := net.ParseIP(address); ip != nil && ip.To4() != nil {
  63                 select {
  64                 case done <- &IPResult{true, address}:
  65                         return
  66                 default:
  67                         return
  68                 }
  69         }
  70 }