// Lookup - lookup host and initialize host IP's
func Lookup(hostport string) (*TCPMap, error) {
host, port, err := net.SplitHostPort(hostport)
if err != nil {
return nil, err
}
portInt, err := strconv.Atoi(port)
if err != nil {
return nil, err
}
resolver, err := dns_resolver.NewFromResolvConf(RESOLVCONFIG)
if err != nil {
resolver = dns_resolver.New([]string{"8.8.8.8", "8.8.4.4"})
} else {
logrus.Debugf("Found %s DNS config, attempting to use it", RESOLVCONFIG)
}
ips, err := resolver.LookupHost(host)
if err != nil {
return nil, err
}
if len(ips) == 0 {
return nil, ErrEmptyIPS
}
tcp := &TCPMap{}
for _, ip := range ips {
tcp.Add(ip, portInt)
}
return tcp, nil
}
// test tests a site and looks at Via support
func (s *site) test(l *os.File) {
resolver := dns_resolver.New([]string{resolverName})
// Check that the origin server resolves
s.resolves.ran = true
name := s.origin
if net.ParseIP(name) == nil {
_, err := resolver.LookupHost(name)
if err != nil {
s.logf(l, "Error resolving name: %s", err)
s.resolves.yesno = false
return
}
}
s.resolves.yesno = true
protocol := "http://"
// Note: we disable compression in the http.Transport so that the
// Go library does not add the Accept-Encoding and does not do
// transparent decompression.
//
// The Accept-Encoding header is added to the request which means
// that we'll potentially get gzipped content in return.
transport := &http.Transport{}
transport.DisableCompression = true
// Custom dialer is needed to use special DNS resolver so that the
// default resolver can be overriden
transport.Dial = func(network, address string) (net.Conn, error) {
host, port, err := net.SplitHostPort(address)
if err != nil {
return nil, err
}
if net.ParseIP(host) != nil {
return net.Dial(network, address)
}
ips, err := resolver.LookupHost(host)
if err != nil {
return nil, err
}
if len(ips) == 0 {
return nil, fmt.Errorf("Failed to get any IPs for %s", address)
}
return net.Dial(network, net.JoinHostPort(ips[0].String(), port))
}
client := &http.Client{Transport: transport}
req, err := http.NewRequest("GET", protocol+name, nil)
req.Header.Set("Accept-Encoding", "gzip,deflate")
req.Header.Set("Host", s.host)
s.noVia.ran = true
if *dump {
fmt.Printf("%#v\n", req)
}
respNoVia, err := client.Do(req)
if *dump {
fmt.Printf("%#v\n", respNoVia)
}
if err != nil {
s.logf(l, "HTTP request %#v failed: %s", req, err)
return
}
s.noVia.yesno = true
sizeNoVia := 0
if respNoVia != nil && respNoVia.Body != nil {
b, _ := ioutil.ReadAll(respNoVia.Body)
sizeNoVia = len(b)
respNoVia.Body.Close()
}
s.noViaSize = sizeNoVia
s.noViaEncoding = respNoVia.Header.Get("Content-Encoding")
s.noViaServer = respNoVia.Header.Get("Server")
transport.CloseIdleConnections()
// Now add the Via header to the same request and repeate
req.Header.Set("Via", "viascan 1.0")
s.via.ran = true
if *dump {
fmt.Printf("%#v\n", req)
}
respVia, err := client.Do(req)
if *dump {
fmt.Printf("%#v\n", respVia)
}
if err != nil {
s.logf(l, "HTTP request %#v failed: %s", req, err)
return
}
s.via.yesno = true
sizeVia := 0
if respVia != nil && respVia.Body != nil {
b, _ := ioutil.ReadAll(respVia.Body)
sizeVia = len(b)
respVia.Body.Close()
}
s.viaSize = sizeVia
s.viaEncoding = respVia.Header.Get("Content-Encoding")
s.viaServer = respVia.Header.Get("Server")
transport.CloseIdleConnections()
}