From f8198c042810b2c512c610654272db845e32b75e Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 25 Aug 2019 12:45:13 -0600
Subject: [PATCH] device: getsockname on linux to determine port

It turns out Go isn't passing the pointer properly so we wound up with a
zero port every time.
---
 device/conn_linux.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/device/conn_linux.go b/device/conn_linux.go
index ebbbe11..f74ad51 100644
--- a/device/conn_linux.go
+++ b/device/conn_linux.go
@@ -391,6 +391,11 @@ func create4(port uint16) (int, uint16, error) {
 		return FD_ERR, 0, err
 	}
 
+	sa, err := unix.Getsockname(fd)
+	if err == nil {
+		addr.Port = sa.(*unix.SockaddrInet4).Port
+	}
+
 	return fd, uint16(addr.Port), err
 }
 
@@ -450,6 +455,11 @@ func create6(port uint16) (int, uint16, error) {
 		return FD_ERR, 0, err
 	}
 
+	sa, err := unix.Getsockname(fd)
+	if err == nil {
+		addr.Port = sa.(*unix.SockaddrInet6).Port
+	}
+
 	return fd, uint16(addr.Port), err
 }