Initial FreeBSD/OpenBSD/NetBSD support (doesn't have syscalls for interface config yet)

syscalls_bsd.go

@@ -0,0 +1,47 @@
+// +build openbsd freebsd netbsd
+
+package water
+
+import (
+	"errors"
+	"os"
+)
+
+func openDev(config Config) (ifce *Interface, err error) {
+	switch config.Name[:8] {
+	case "/dev/tap":
+		return newTAP(config)
+	case "/dev/tun":
+		return newTUN(config)
+	default:
+		return nil, errors.New("unrecognized driver")
+	}
+}
+
+func newTAP(config Config) (ifce *Interface, err error) {
+	if config.Name[:8] != "/dev/tap" {
+		panic("TUN/TAP name must be in format /dev/tunX or /dev/tapX")
+	}
+
+	file, err := os.OpenFile(config.Name, os.O_RDWR, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	ifce = &Interface{isTAP: true, ReadWriteCloser: file, name: config.Name[5:]}
+	return
+}
+
+func newTUN(config Config) (ifce *Interface, err error) {
+	if config.Name[:8] != "/dev/tun" {
+		panic("TUN/TAP name must be in format /dev/tunX or /dev/tapX")
+	}
+
+	file, err := os.OpenFile(config.Name, os.O_RDWR, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	ifce = &Interface{isTAP: false, ReadWriteCloser: file, name: config.Name[5:]}
+	return
+}