Initial commit

proxy/server.go

@@ -0,0 +1,197 @@
+package proxy
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	"golang.org/x/net/proxy"
+	"proxy-pool/config"
+	"proxy-pool/storage"
+)
+
+type Server struct {
+	storage *storage.Storage
+	cfg     *config.Config
+}
+
+func New(s *storage.Storage, cfg *config.Config) *Server {
+	return &Server{
+		storage: s,
+		cfg:     cfg,
+	}
+}
+
+func (s *Server) Start() error {
+	log.Printf("proxy server listening on %s", s.cfg.ProxyPort)
+	return http.ListenAndServe(s.cfg.ProxyPort, s)
+}
+
+func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodConnect {
+		s.handleTunnel(w, r)
+	} else {
+		s.handleHTTP(w, r)
+	}
+}
+
+// handleHTTP 处理普通 HTTP 请求（带自动重试）
+func (s *Server) handleHTTP(w http.ResponseWriter, r *http.Request) {
+	var tried []string
+	for attempt := 0; attempt <= s.cfg.MaxRetry; attempt++ {
+		p, err := s.storage.GetRandomExclude(tried)
+		if err != nil {
+			http.Error(w, "no available proxy", http.StatusServiceUnavailable)
+			return
+		}
+
+		client, err := s.buildClient(p)
+		if err != nil {
+			s.storage.Delete(p.Address)
+			continue
+		}
+
+		// 转发请求（使用完整 URL，上游代理通过 client transport 设置）
+		req, err := http.NewRequest(r.Method, r.URL.String(), r.Body)
+		if err != nil {
+			continue
+		}
+		req.Header = r.Header.Clone()
+		req.Header.Del("Proxy-Connection")
+
+		resp, err := client.Do(req)
+		if err != nil {
+			log.Printf("[proxy] %s via %s failed, removing", r.RequestURI, p.Address)
+			s.storage.Delete(p.Address)
+			continue
+		}
+		defer resp.Body.Close()
+
+		// 写回响应
+		for k, vv := range resp.Header {
+			for _, v := range vv {
+				w.Header().Add(k, v)
+			}
+		}
+		w.WriteHeader(resp.StatusCode)
+		io.Copy(w, resp.Body)
+		if resp.StatusCode == 429 {
+			log.Printf("[proxy] ⚠️  429 %s via %s (protocol=%s)", r.RequestURI, p.Address, p.Protocol)
+		} else {
+			log.Printf("[proxy] %s via %s -> %d", r.RequestURI, p.Address, resp.StatusCode)
+		}
+		return
+	}
+
+	http.Error(w, "all proxies failed", http.StatusBadGateway)
+}
+
+// handleTunnel 处理 HTTPS CONNECT 隧道（带自动重试）
+func (s *Server) handleTunnel(w http.ResponseWriter, r *http.Request) {
+	var tried []string
+	for attempt := 0; attempt <= s.cfg.MaxRetry; attempt++ {
+		p, err := s.storage.GetRandomExclude(tried)
+		if err != nil {
+			http.Error(w, "no available proxy", http.StatusServiceUnavailable)
+			return
+		}
+
+		conn, err := s.dialViaProxy(p, r.Host)
+		if err != nil {
+			log.Printf("[tunnel] dial %s via %s failed, removing", r.Host, p.Address)
+			s.storage.Delete(p.Address)
+			continue
+		}
+
+		// 告知客户端隧道建立
+		hijacker, ok := w.(http.Hijacker)
+		if !ok {
+			conn.Close()
+			http.Error(w, "hijack not supported", http.StatusInternalServerError)
+			return
+		}
+		clientConn, _, err := hijacker.Hijack()
+		if err != nil {
+			conn.Close()
+			return
+		}
+
+		fmt.Fprintf(clientConn, "HTTP/1.1 200 Connection Established\r\n\r\n")
+		log.Printf("[tunnel] %s via %s established", r.Host, p.Address)
+
+		// 双向转发
+		go transfer(conn, clientConn)
+		go transfer(clientConn, conn)
+		return
+	}
+
+	http.Error(w, "all proxies failed", http.StatusBadGateway)
+}
+
+func (s *Server) dialViaProxy(p *storage.Proxy, host string) (net.Conn, error) {
+	timeout := time.Duration(s.cfg.ValidateTimeout) * time.Second
+	switch p.Protocol {
+	case "http":
+		conn, err := net.DialTimeout("tcp", p.Address, timeout)
+		if err != nil {
+			return nil, err
+		}
+		// 发送 CONNECT 请求给上游 HTTP 代理
+		fmt.Fprintf(conn, "CONNECT %s HTTP/1.1\r\nHost: %s\r\n\r\n", host, host)
+		buf := make([]byte, 256)
+		n, err := conn.Read(buf)
+		if err != nil {
+			conn.Close()
+			return nil, err
+		}
+		if n < 12 {
+			conn.Close()
+			return nil, fmt.Errorf("short response from proxy")
+		}
+		return conn, nil
+	case "socks5":
+		dialer, err := proxy.SOCKS5("tcp", p.Address, nil, proxy.Direct)
+		if err != nil {
+			return nil, err
+		}
+		return dialer.Dial("tcp", host)
+	default:
+		return nil, fmt.Errorf("unsupported protocol: %s", p.Protocol)
+	}
+}
+
+func (s *Server) buildClient(p *storage.Proxy) (*http.Client, error) {
+	timeout := time.Duration(s.cfg.ValidateTimeout) * time.Second
+	switch p.Protocol {
+	case "http":
+		proxyURL, err := url.Parse(fmt.Sprintf("http://%s", p.Address))
+		if err != nil {
+			return nil, err
+		}
+		return &http.Client{
+			Transport: &http.Transport{Proxy: http.ProxyURL(proxyURL)},
+			Timeout:   timeout,
+		}, nil
+	case "socks5":
+		dialer, err := proxy.SOCKS5("tcp", p.Address, nil, proxy.Direct)
+		if err != nil {
+			return nil, err
+		}
+		return &http.Client{
+			Transport: &http.Transport{Dial: dialer.Dial},
+			Timeout:   timeout,
+		}, nil
+	default:
+		return nil, fmt.Errorf("unsupported protocol: %s", p.Protocol)
+	}
+}
+
+func transfer(dst io.WriteCloser, src io.ReadCloser) {
+	defer dst.Close()
+	defer src.Close()
+	io.Copy(dst, src)
+}