From 12ce53271baa04a8a8a2c491e1604c53d5f05cfb Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 23 Mar 2021 12:41:34 -0600
Subject: tun: freebsd: use broadcast mode instead of PPP mode

It makes the routing configuration simpler.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 tun/tun_freebsd.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tun/tun_freebsd.go b/tun/tun_freebsd.go
index 1883aad..c2ad65f 100644
--- a/tun/tun_freebsd.go
+++ b/tun/tun_freebsd.go
@@ -292,6 +292,23 @@ func CreateTUN(name string, mtu int) (Device, error) {
 		return nil, fmt.Errorf("Unable to put into IFHEAD mode: %w", errno)
 	}
 
+	// Get out of PPP mode.
+	ifflags := syscall.IFF_BROADCAST
+	tun.operateOnFd(func(fd uintptr) {
+		_, _, errno = unix.Syscall(
+			unix.SYS_IOCTL,
+			fd,
+			uintptr(_TUNSIFMODE),
+			uintptr(unsafe.Pointer(&ifflags)),
+		)
+	})
+
+	if errno != 0 {
+		tunFile.Close()
+		tunDestroy(assignedName)
+		return nil, fmt.Errorf("Unable to put into IFF_BROADCAST mode: %w", errno)
+	}
+
 	// Open control sockets
 	confd, err := unix.Socket(
 		unix.AF_INET,
-- 
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