wgengine: start logging DISCO frames to pcap stream

Signed-off-by: Tom DNetto <tom@tailscale.com>

wgengine/wgengine.go

@@ -43,12 +43,6 @@ type NetInfoCallback func(*tailcfg.NetInfo)
 // into network map updates.
 type NetworkMapCallback func(*netmap.NetworkMap)
 
-// CaptureCallback is the type used to record packets when
-// debugging packet-capture. This function must not take
-// ownership of the provided data slice: it may only copy
-// out of it within the lifetime of the function.
-type CaptureCallback func(capture.Path, time.Time, []byte)
-
 // someHandle is allocated so its pointer address acts as a unique
 // map key handle. (It needs to have non-zero size for Go to guarantee
 // the pointer is unique.)
@@ -182,5 +176,5 @@ type Engine interface {
 	// InstallCaptureHook registers a function to be called to capture
 	// packets traversing the data path. The hook can be uninstalled by
 	// calling this function with a nil value.
-	InstallCaptureHook(CaptureCallback)
+	InstallCaptureHook(capture.Callback)
 }