From ffffbbcc8a3344a45c45884f11a1aee1407615ab Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Mon, 21 Oct 2019 13:29:57 +0200 Subject: device: allow blackholing sockets --- device/boundif_windows.go | 6 ++++-- device/conn_default.go | 12 ++++++++++-- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/device/boundif_windows.go b/device/boundif_windows.go index 7879a43..6908415 100644 --- a/device/boundif_windows.go +++ b/device/boundif_windows.go @@ -18,7 +18,7 @@ const ( sockoptIPV6_UNICAST_IF = 31 ) -func (device *Device) BindSocketToInterface4(interfaceIndex uint32) error { +func (device *Device) BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error { /* MSDN says for IPv4 this needs to be in net byte order, so that it's like an IP address with leading zeros. */ bytes := make([]byte, 4) binary.BigEndian.PutUint32(bytes, interfaceIndex) @@ -41,10 +41,11 @@ func (device *Device) BindSocketToInterface4(interfaceIndex uint32) error { if err != nil { return err } + device.net.bind.(*nativeBind).blackhole4 = blackhole return nil } -func (device *Device) BindSocketToInterface6(interfaceIndex uint32) error { +func (device *Device) BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error { sysconn, err := device.net.bind.(*nativeBind).ipv6.SyscallConn() if err != nil { return err @@ -58,5 +59,6 @@ func (device *Device) BindSocketToInterface6(interfaceIndex uint32) error { if err != nil { return err } + device.net.bind.(*nativeBind).blackhole6 = blackhole return nil } diff --git a/device/conn_default.go b/device/conn_default.go index 820bb96..661f57d 100644 --- a/device/conn_default.go +++ b/device/conn_default.go @@ -21,8 +21,10 @@ import ( */ type nativeBind struct { - ipv4 *net.UDPConn - ipv6 *net.UDPConn + ipv4 *net.UDPConn + ipv6 *net.UDPConn + blackhole4 bool + blackhole6 bool } type NativeEndpoint net.UDPAddr @@ -159,11 +161,17 @@ func (bind *nativeBind) Send(buff []byte, endpoint Endpoint) error { if bind.ipv4 == nil { return syscall.EAFNOSUPPORT } + if bind.blackhole4 { + return nil + } _, err = bind.ipv4.WriteToUDP(buff, (*net.UDPAddr)(nend)) } else { if bind.ipv6 == nil { return syscall.EAFNOSUPPORT } + if bind.blackhole6 { + return nil + } _, err = bind.ipv6.WriteToUDP(buff, (*net.UDPAddr)(nend)) } return err -- cgit v1.2.3