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Copy pathhttp.go
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468 lines (394 loc) · 10.7 KB
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package gost
import (
"bufio"
"bytes"
"context"
"encoding/base64"
"fmt"
"net"
"net/http"
"net/http/httputil"
"net/url"
"os"
"strconv"
"strings"
"time"
"github.com/go-log/log"
)
type httpConnector struct {
User *url.Userinfo
}
// HTTPConnector creates a Connector for HTTP proxy client.
// It accepts an optional auth info for HTTP Basic Authentication.
func HTTPConnector(user *url.Userinfo) Connector {
return &httpConnector{User: user}
}
func (c *httpConnector) Connect(conn net.Conn, address string, options ...ConnectOption) (net.Conn, error) {
return c.ConnectContext(context.Background(), conn, "tcp", address, options...)
}
func (c *httpConnector) ConnectContext(ctx context.Context, conn net.Conn, network, address string, options ...ConnectOption) (net.Conn, error) {
switch network {
case "udp", "udp4", "udp6":
return nil, fmt.Errorf("%s unsupported", network)
}
opts := &ConnectOptions{}
for _, option := range options {
option(opts)
}
timeout := opts.Timeout
if timeout <= 0 {
timeout = ConnectTimeout
}
ua := opts.UserAgent
if ua == "" {
ua = DefaultUserAgent
}
conn.SetDeadline(time.Now().Add(timeout))
defer conn.SetDeadline(time.Time{})
req := &http.Request{
Method: http.MethodConnect,
URL: &url.URL{Host: address},
Host: address,
ProtoMajor: 1,
ProtoMinor: 1,
Header: make(http.Header),
}
req.Header.Set("User-Agent", ua)
req.Header.Set("Proxy-Connection", "keep-alive")
user := opts.User
if user == nil {
user = c.User
}
if user != nil {
u := user.Username()
p, _ := user.Password()
req.Header.Set("Proxy-Authorization",
"Basic "+base64.StdEncoding.EncodeToString([]byte(u+":"+p)))
}
if err := req.Write(conn); err != nil {
return nil, err
}
if Debug {
dump, _ := httputil.DumpRequest(req, false)
log.Log(string(dump))
}
resp, err := http.ReadResponse(bufio.NewReader(conn), req)
if err != nil {
return nil, err
}
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Log(string(dump))
}
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%s", resp.Status)
}
return conn, nil
}
type httpHandler struct {
options *HandlerOptions
}
// HTTPHandler creates a server Handler for HTTP proxy server.
func HTTPHandler(opts ...HandlerOption) Handler {
h := &httpHandler{}
h.Init(opts...)
return h
}
func (h *httpHandler) Init(options ...HandlerOption) {
if h.options == nil {
h.options = &HandlerOptions{}
}
for _, opt := range options {
opt(h.options)
}
}
func (h *httpHandler) Handle(conn net.Conn) {
defer conn.Close()
req, err := http.ReadRequest(bufio.NewReader(conn))
if err != nil {
log.Logf("[http] %s - %s : %s", conn.RemoteAddr(), conn.LocalAddr(), err)
return
}
defer req.Body.Close()
h.handleRequest(conn, req)
}
func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
if req == nil {
return
}
// try to get the actual host.
if v := req.Header.Get("Gost-Target"); v != "" {
if h, err := decodeServerName(v); err == nil {
req.Host = h
}
}
host := req.Host
if _, port, _ := net.SplitHostPort(host); port == "" {
host = net.JoinHostPort(host, "80")
}
u, _, _ := basicProxyAuth(req.Header.Get("Proxy-Authorization"))
if u != "" {
u += "@"
}
log.Logf("[http] %s%s -> %s -> %s",
u, conn.RemoteAddr(), h.options.Node.String(), host)
if Debug {
dump, _ := httputil.DumpRequest(req, false)
log.Logf("[http] %s -> %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
req.Header.Del("Gost-Target")
resp := &http.Response{
ProtoMajor: 1,
ProtoMinor: 1,
Header: http.Header{},
}
resp.Header.Add("Proxy-Agent", "gost/"+Version)
if !Can("tcp", host, h.options.Whitelist, h.options.Blacklist) {
log.Logf("[http] %s - %s : Unauthorized to tcp connect to %s",
conn.RemoteAddr(), conn.LocalAddr(), host)
resp.StatusCode = http.StatusForbidden
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Logf("[http] %s <- %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
resp.Write(conn)
return
}
if h.options.Bypass.Contains(host) {
resp.StatusCode = http.StatusForbidden
log.Logf("[http] %s - %s bypass %s",
conn.RemoteAddr(), conn.LocalAddr(), host)
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Logf("[http] %s <- %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
resp.Write(conn)
return
}
if !h.authenticate(conn, req, resp) {
return
}
if req.Method == "PRI" || (req.Method != http.MethodConnect && req.URL.Scheme != "http") {
resp.StatusCode = http.StatusBadRequest
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Logf("[http] %s <- %s\n%s",
conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
resp.Write(conn)
return
}
req.Header.Del("Proxy-Authorization")
retries := 1
if h.options.Chain != nil && h.options.Chain.Retries > 0 {
retries = h.options.Chain.Retries
}
if h.options.Retries > 0 {
retries = h.options.Retries
}
var err error
var cc net.Conn
var route *Chain
for i := 0; i < retries; i++ {
route, err = h.options.Chain.selectRouteFor(host)
if err != nil {
log.Logf("[http] %s -> %s : %s",
conn.RemoteAddr(), conn.LocalAddr(), err)
continue
}
buf := bytes.Buffer{}
fmt.Fprintf(&buf, "%s -> %s -> ",
conn.RemoteAddr(), h.options.Node.String())
for _, nd := range route.route {
fmt.Fprintf(&buf, "%d@%s -> ", nd.ID, nd.String())
}
fmt.Fprintf(&buf, "%s", host)
log.Log("[route]", buf.String())
// forward http request
lastNode := route.LastNode()
if req.Method != http.MethodConnect && lastNode.Protocol == "http" {
err = h.forwardRequest(conn, req, route)
if err == nil {
return
}
log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), conn.LocalAddr(), err)
continue
}
cc, err = route.Dial(host,
TimeoutChainOption(h.options.Timeout),
HostsChainOption(h.options.Hosts),
ResolverChainOption(h.options.Resolver),
)
if err == nil {
break
}
log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), conn.LocalAddr(), err)
}
if err != nil {
resp.StatusCode = http.StatusServiceUnavailable
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Logf("[http] %s <- %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
resp.Write(conn)
return
}
defer cc.Close()
if req.Method == http.MethodConnect {
b := []byte("HTTP/1.1 200 Connection established\r\n" +
"Proxy-Agent: gost/" + Version + "\r\n\r\n")
if Debug {
log.Logf("[http] %s <- %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(b))
}
conn.Write(b)
} else {
req.Header.Del("Proxy-Connection")
if err = req.Write(cc); err != nil {
log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), conn.LocalAddr(), err)
return
}
}
log.Logf("[http] %s <-> %s", conn.RemoteAddr(), host)
transport(conn, cc)
log.Logf("[http] %s >-< %s", conn.RemoteAddr(), host)
}
func (h *httpHandler) authenticate(conn net.Conn, req *http.Request, resp *http.Response) (ok bool) {
u, p, _ := basicProxyAuth(req.Header.Get("Proxy-Authorization"))
if Debug && (u != "" || p != "") {
log.Logf("[http] %s -> %s : Authorization '%s' '%s'",
conn.RemoteAddr(), conn.LocalAddr(), u, p)
}
if h.options.Authenticator == nil || h.options.Authenticator.Authenticate(u, p) {
return true
}
// probing resistance is enabled, and knocking host is mismatch.
if ss := strings.SplitN(h.options.ProbeResist, ":", 2); len(ss) == 2 &&
(h.options.KnockingHost == "" || !strings.EqualFold(req.URL.Hostname(), h.options.KnockingHost)) {
resp.StatusCode = http.StatusServiceUnavailable // default status code
switch ss[0] {
case "code":
resp.StatusCode, _ = strconv.Atoi(ss[1])
case "web":
url := ss[1]
if !strings.HasPrefix(url, "http") {
url = "http://" + url
}
if r, err := http.Get(url); err == nil {
resp = r
}
case "host":
cc, err := net.Dial("tcp", ss[1])
if err == nil {
defer cc.Close()
req.Write(cc)
log.Logf("[http] %s <-> %s : forward to %s",
conn.RemoteAddr(), conn.LocalAddr(), ss[1])
transport(conn, cc)
log.Logf("[http] %s >-< %s : forward to %s",
conn.RemoteAddr(), conn.LocalAddr(), ss[1])
return
}
case "file":
f, _ := os.Open(ss[1])
if f != nil {
resp.StatusCode = http.StatusOK
if finfo, _ := f.Stat(); finfo != nil {
resp.ContentLength = finfo.Size()
}
resp.Header.Set("Content-Type", "text/html")
resp.Body = f
}
}
}
if resp.StatusCode == 0 {
log.Logf("[http] %s <- %s : proxy authentication required",
conn.RemoteAddr(), conn.LocalAddr())
resp.StatusCode = http.StatusProxyAuthRequired
resp.Header.Add("Proxy-Authenticate", "Basic realm=\"gost\"")
} else {
resp.Header = http.Header{}
resp.Header.Set("Server", "nginx/1.14.1")
resp.Header.Set("Date", time.Now().Format(http.TimeFormat))
if resp.StatusCode == http.StatusOK {
resp.Header.Set("Connection", "keep-alive")
}
}
if Debug {
dump, _ := httputil.DumpResponse(resp, false)
log.Logf("[http] %s <- %s\n%s",
conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
resp.Write(conn)
return
}
func (h *httpHandler) forwardRequest(conn net.Conn, req *http.Request, route *Chain) error {
if route.IsEmpty() {
return nil
}
host := req.Host
var userpass string
if user := route.LastNode().User; user != nil {
u := user.Username()
p, _ := user.Password()
userpass = base64.StdEncoding.EncodeToString([]byte(u + ":" + p))
}
cc, err := route.Conn()
if err != nil {
return err
}
defer cc.Close()
errc := make(chan error, 1)
go func() {
errc <- copyBuffer(conn, cc)
}()
go func() {
for {
if userpass != "" {
req.Header.Set("Proxy-Authorization", "Basic "+userpass)
}
cc.SetWriteDeadline(time.Now().Add(WriteTimeout))
if !req.URL.IsAbs() {
req.URL.Scheme = "http" // make sure that the URL is absolute
}
err := req.WriteProxy(cc)
if err != nil {
log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), conn.LocalAddr(), err)
errc <- err
return
}
cc.SetWriteDeadline(time.Time{})
req, err = http.ReadRequest(bufio.NewReader(conn))
if err != nil {
errc <- err
return
}
if Debug {
dump, _ := httputil.DumpRequest(req, false)
log.Logf("[http] %s -> %s\n%s",
conn.RemoteAddr(), conn.LocalAddr(), string(dump))
}
}
}()
log.Logf("[http] %s <-> %s", conn.RemoteAddr(), host)
<-errc
log.Logf("[http] %s >-< %s", conn.RemoteAddr(), host)
return nil
}
func basicProxyAuth(proxyAuth string) (username, password string, ok bool) {
if proxyAuth == "" {
return
}
if !strings.HasPrefix(proxyAuth, "Basic ") {
return
}
c, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(proxyAuth, "Basic "))
if err != nil {
return
}
cs := string(c)
s := strings.IndexByte(cs, ':')
if s < 0 {
return
}
return cs[:s], cs[s+1:], true
}