Use runtime-dir Unix sockets for local gRPC

internal/api/host.go

@@ -4,10 +4,13 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"os"
+	"path/filepath"
 	"strings"
 	"sync"
 
 	"git.julianfamily.org/keepassgo/internal/clipboard"
+	"git.julianfamily.org/keepassgo/internal/grpcaddr"
 	"git.julianfamily.org/keepassgo/internal/passwords"
 	"git.julianfamily.org/keepassgo/internal/session"
 	"git.julianfamily.org/keepassgo/internal/vault"
@@ -27,6 +30,7 @@ type Host struct {
 	lastModel  vault.Model
 	started    bool
 	listenAddr string
+	socketPath string
 }
 
 func StartHost(addr string, lifecycle lifecycleBackend, profiles map[string]passwords.Profile, clipboardWriter clipboard.Writer, dirty DirtyProvider) (*Host, error) {
@@ -35,7 +39,11 @@ func StartHost(addr string, lifecycle lifecycleBackend, profiles map[string]pass
 		return nil, nil
 	}
 
-	listener, err := net.Listen("tcp", addr)
+	network, endpoint, err := grpcaddr.Parse(addr)
+	if err != nil {
+		return nil, err
+	}
+	listener, socketPath, err := listen(network, endpoint)
 	if err != nil {
 		return nil, fmt.Errorf("listen gRPC host %s: %w", addr, err)
 	}
@@ -50,7 +58,8 @@ func StartHost(addr string, lifecycle lifecycleBackend, profiles map[string]pass
 		listener:   listener,
 		lifecycle:  lifecycle,
 		dirty:      dirty,
-		listenAddr: listener.Addr().String(),
+		listenAddr: formatListenAddress(network, listener.Addr().String(), socketPath),
+		socketPath: socketPath,
 		started:    true,
 	}
 	if err := host.SyncFromLifecycle(); err != nil && !errors.Is(err, session.ErrLocked) {
@@ -91,7 +100,13 @@ func (h *Host) Stop() error {
 	}
 	h.started = false
 	h.grpcServer.Stop()
-	return h.listener.Close()
+	err := h.listener.Close()
+	if h.socketPath != "" {
+		if removeErr := os.Remove(h.socketPath); removeErr != nil && !errors.Is(removeErr, os.ErrNotExist) && err == nil {
+			err = removeErr
+		}
+	}
+	return err
 }
 
 func (h *Host) SyncFromLifecycle() error {
@@ -120,3 +135,35 @@ func (h *Host) SyncFromLifecycle() error {
 	h.server.SetSessionState(h.lastModel, locked, dirty)
 	return nil
 }
+
+func listen(network, endpoint string) (net.Listener, string, error) {
+	if network == "unix" {
+		if err := os.MkdirAll(filepath.Dir(endpoint), 0o700); err != nil {
+			return nil, "", err
+		}
+		if err := os.Remove(endpoint); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return nil, "", err
+		}
+		listener, err := net.Listen("unix", endpoint)
+		if err != nil {
+			return nil, "", err
+		}
+		if err := os.Chmod(endpoint, 0o600); err != nil {
+			_ = listener.Close()
+			return nil, "", err
+		}
+		return listener, endpoint, nil
+	}
+	listener, err := net.Listen(network, endpoint)
+	if err != nil {
+		return nil, "", err
+	}
+	return listener, "", nil
+}
+
+func formatListenAddress(network, listenerAddr, socketPath string) string {
+	if network == "unix" {
+		return "unix://" + socketPath
+	}
+	return listenerAddr
+}