Refactor: HTTP clients, unified HTTP2/QUIC options, Apple engines

common/httpclient/helpers.go

@@ -0,0 +1,86 @@
+package httpclient
+
+import (
+	"context"
+	stdTLS "crypto/tls"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/sagernet/sing-box/common/tls"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func dialTLS(ctx context.Context, rawDialer N.Dialer, baseTLSConfig tls.Config, destination M.Socksaddr, nextProtos []string, expectProto string) (net.Conn, error) {
+	if baseTLSConfig == nil {
+		return nil, E.New("TLS transport unavailable")
+	}
+	tlsConfig := baseTLSConfig.Clone()
+	if tlsConfig.ServerName() == "" && destination.IsValid() {
+		tlsConfig.SetServerName(destination.AddrString())
+	}
+	tlsConfig.SetNextProtos(nextProtos)
+	conn, err := rawDialer.DialContext(ctx, N.NetworkTCP, destination)
+	if err != nil {
+		return nil, err
+	}
+	tlsConn, err := tls.ClientHandshake(ctx, conn, tlsConfig)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	if expectProto != "" && tlsConn.ConnectionState().NegotiatedProtocol != expectProto {
+		tlsConn.Close()
+		return nil, errHTTP2Fallback
+	}
+	return tlsConn, nil
+}
+
+func applyHeaders(request *http.Request, headers http.Header, host string) {
+	for header, values := range headers {
+		request.Header[header] = append([]string(nil), values...)
+	}
+	if host != "" {
+		request.Host = host
+	}
+}
+
+func requestRequiresHTTP1(request *http.Request) bool {
+	return strings.Contains(strings.ToLower(request.Header.Get("Connection")), "upgrade") &&
+		strings.EqualFold(request.Header.Get("Upgrade"), "websocket")
+}
+
+func requestReplayable(request *http.Request) bool {
+	return request.Body == nil || request.Body == http.NoBody || request.GetBody != nil
+}
+
+func cloneRequestForRetry(request *http.Request) *http.Request {
+	cloned := request.Clone(request.Context())
+	if request.Body != nil && request.Body != http.NoBody && request.GetBody != nil {
+		cloned.Body = mustGetBody(request)
+	}
+	return cloned
+}
+
+func mustGetBody(request *http.Request) io.ReadCloser {
+	body, err := request.GetBody()
+	if err != nil {
+		panic(err)
+	}
+	return body
+}
+
+func buildSTDTLSConfig(baseTLSConfig tls.Config, destination M.Socksaddr, nextProtos []string) (*stdTLS.Config, error) {
+	if baseTLSConfig == nil {
+		return nil, nil
+	}
+	tlsConfig := baseTLSConfig.Clone()
+	if tlsConfig.ServerName() == "" && destination.IsValid() {
+		tlsConfig.SetServerName(destination.AddrString())
+	}
+	tlsConfig.SetNextProtos(nextProtos)
+	return tlsConfig.STDConfig()
+}