Initial commit.

internal/daemon/peercred_linux.go

@@ -0,0 +1,37 @@
+//go:build linux
+
+package daemon
+
+import (
+	"net"
+
+	"golang.org/x/sys/unix"
+)
+
+// getPeerCredentials extracts peer credentials from a Unix socket connection on Linux.
+func (s *Server) getPeerCredentials(conn net.Conn) *PeerCredentials {
+	unixConn, ok := conn.(*net.UnixConn)
+	if !ok {
+		return nil
+	}
+
+	rawConn, err := unixConn.SyscallConn()
+	if err != nil {
+		return nil
+	}
+
+	var creds *PeerCredentials
+	rawConn.Control(func(fd uintptr) {
+		ucred, err := unix.GetsockoptUcred(int(fd), unix.SOL_SOCKET, unix.SO_PEERCRED)
+		if err != nil {
+			return
+		}
+		creds = &PeerCredentials{
+			UID: ucred.Uid,
+			GID: ucred.Gid,
+			PID: ucred.Pid,
+		}
+	})
+
+	return creds
+}