micro/transport/http/http_proxy.go

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2020-08-10 17:58:39 +03:00
package http
2019-01-02 18:24:17 +03:00
import (
"bufio"
"encoding/base64"
"fmt"
"io"
"net"
"net/http"
"net/http/httputil"
"net/url"
)
const (
proxyAuthHeader = "Proxy-Authorization"
)
func getURL(addr string) (*url.URL, error) {
r := &http.Request{
URL: &url.URL{
Scheme: "https",
Host: addr,
},
}
return http.ProxyFromEnvironment(r)
}
type pbuffer struct {
net.Conn
r io.Reader
}
func (p *pbuffer) Read(b []byte) (int, error) {
return p.r.Read(b)
}
func proxyDial(conn net.Conn, addr string, proxyURL *url.URL) (_ net.Conn, err error) {
defer func() {
if err != nil {
conn.Close()
}
}()
r := &http.Request{
Method: http.MethodConnect,
URL: &url.URL{Host: addr},
Header: map[string][]string{"User-Agent": {"micro/latest"}},
}
if user := proxyURL.User; user != nil {
u := user.Username()
p, _ := user.Password()
auth := []byte(u + ":" + p)
basicAuth := base64.StdEncoding.EncodeToString(auth)
r.Header.Add(proxyAuthHeader, "Basic "+basicAuth)
}
if err := r.Write(conn); err != nil {
return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
}
br := bufio.NewReader(conn)
rsp, err := http.ReadResponse(br, r)
if err != nil {
return nil, fmt.Errorf("reading server HTTP response: %v", err)
}
defer rsp.Body.Close()
if rsp.StatusCode != http.StatusOK {
dump, err := httputil.DumpResponse(rsp, true)
if err != nil {
return nil, fmt.Errorf("failed to do connect handshake, status code: %s", rsp.Status)
}
return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
}
return &pbuffer{Conn: conn, r: br}, nil
}
// Creates a new connection
func newConn(dial func(string) (net.Conn, error)) func(string) (net.Conn, error) {
return func(addr string) (net.Conn, error) {
// get the proxy url
proxyURL, err := getURL(addr)
if err != nil {
return nil, err
}
// set to addr
callAddr := addr
// got proxy
if proxyURL != nil {
callAddr = proxyURL.Host
}
// dial the addr
c, err := dial(callAddr)
if err != nil {
return nil, err
}
// do proxy connect if we have proxy url
if proxyURL != nil {
c, err = proxyDial(c, addr, proxyURL)
}
return c, err
}
}