Add partial (client) binding support for BSD (#260)

1 files changed, 18 insertions, 0 deletions

diff --git a/dhcpv4/bindtodevice_bsd.go b/dhcpv4/bindtodevice_bsd.go
new file mode 100644
index 0000000..0f1b581
--- /dev/null
+++ b/dhcpv4/bindtodevice_bsd.go
@@ -0,0 +1,18 @@
+// +build freebsd openbsd netbsd
+
+package dhcpv4
+
+import (
+	"net"
+	"syscall"
+)
+
+// BindToInterface emulates linux's SO_BINDTODEVICE option for a socket by using
+// IP_RECVIF.
+func BindToInterface(fd int, ifname string) error {
+	iface, err := net.InterfaceByName(ifname)
+	if err != nil {
+		return err
+	}
+	return syscall.SetsockoptInt(fd, syscall.IPPROTO_IP, syscall.IP_RECVIF, iface.Index)
+}