bastion 0.53.2

client-go/service_peer.go

@@ -0,0 +1,28 @@
+//go:build linux || darwin
+
+package main
+
+import (
+	"errors"
+	"net"
+)
+
+// servicePeerUID is the uid the kernel stamped on the OTHER end of a unix
+// socket connection at connect() time (SO_PEERCRED / LOCAL_PEERCRED via
+// contextPeerUID). It is who is actually listening, whatever the path said.
+func servicePeerUID(c net.Conn) (uint32, error) {
+	uc, ok := c.(*net.UnixConn)
+	if !ok {
+		return 0, errors.New("not a unix socket connection")
+	}
+	raw, err := uc.SyscallConn()
+	if err != nil {
+		return 0, err
+	}
+	var uid uint32
+	var cerr error
+	if err := raw.Control(func(fd uintptr) { uid, cerr = contextPeerUID(fd) }); err != nil {
+		return 0, err
+	}
+	return uid, cerr
+}