From ffffbbcc8a3344a45c45884f11a1aee1407615ab Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Mon, 21 Oct 2019 13:29:57 +0200
Subject: [PATCH] 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