Add sing-box API service

experimental/libbox/command_client_remote.go

@@ -0,0 +1,101 @@
+package libbox
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/metadata"
+)
+
+type RemoteConnectionOptions struct {
+	URL    string
+	Secret string
+}
+
+const commandClientRemoteProbeTimeout = 10 * time.Second
+
+type remoteConnection struct {
+	target      string
+	dialOptions []grpc.DialOption
+}
+
+func newRemoteConnection(options *RemoteConnectionOptions) (*remoteConnection, error) {
+	if options == nil {
+		return nil, E.New("missing remote connection options")
+	}
+	urlString := options.URL
+	if !strings.Contains(urlString, "://") {
+		urlString = "http://" + urlString
+	}
+	serverURL, err := url.Parse(urlString)
+	if err != nil {
+		return nil, E.Cause(err, "parse server URL")
+	}
+	host := serverURL.Hostname()
+	if host == "" {
+		return nil, E.New("missing host in server URL: ", options.URL)
+	}
+	var (
+		transportCredentials credentials.TransportCredentials
+		defaultPort          string
+	)
+	switch serverURL.Scheme {
+	case "http":
+		transportCredentials = insecure.NewCredentials()
+		defaultPort = "80"
+	case "https":
+		transportCredentials = credentials.NewTLS(&tls.Config{ServerName: host})
+		defaultPort = "443"
+	default:
+		return nil, E.New("unsupported server URL scheme: ", serverURL.Scheme, ", expected http or https")
+	}
+	port := serverURL.Port()
+	if port == "" {
+		port = defaultPort
+	}
+	dialOptions := []grpc.DialOption{
+		grpc.WithTransportCredentials(transportCredentials),
+	}
+	if options.Secret != "" {
+		authorization := "Bearer " + options.Secret
+		dialOptions = append(dialOptions,
+			grpc.WithUnaryInterceptor(func(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+				return invoker(metadata.AppendToOutgoingContext(ctx, "authorization", authorization), method, req, reply, cc, opts...)
+			}),
+			grpc.WithStreamInterceptor(func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+				return streamer(metadata.AppendToOutgoingContext(ctx, "authorization", authorization), desc, cc, method, opts...)
+			}),
+		)
+	}
+	return &remoteConnection{
+		target:      net.JoinHostPort(host, port),
+		dialOptions: dialOptions,
+	}, nil
+}
+
+func NewRemoteCommandClient(handler CommandClientHandler, options *CommandClientOptions, remoteOptions *RemoteConnectionOptions) (*CommandClient, error) {
+	remote, err := newRemoteConnection(remoteOptions)
+	if err != nil {
+		return nil, err
+	}
+	client := NewCommandClient(handler, options)
+	client.remote = remote
+	return client, nil
+}
+
+func NewStandaloneRemoteCommandClient(remoteOptions *RemoteConnectionOptions) (*CommandClient, error) {
+	remote, err := newRemoteConnection(remoteOptions)
+	if err != nil {
+		return nil, err
+	}
+	return &CommandClient{remote: remote}, nil
+}