tun: guard Device.Events() against chan writes

Signed-off-by: Jordan Whited <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

Author: jwhited

tun/netstack/tun.go

@@ -109,7 +109,7 @@ func (tun *netTun) File() *os.File {
 	return nil
 }
 
-func (tun *netTun) Events() chan tun.Event {
+func (tun *netTun) Events() <-chan tun.Event {
 	return tun.events
 }
 

tun/tun.go

@@ -24,6 +24,6 @@ type Device interface {
 	Flush() error                   // flush all previous writes to the device
 	MTU() (int, error)              // returns the MTU of the device
 	Name() (string, error)          // fetches and returns the current name
-	Events() chan Event             // returns a constant channel of events related to the device
+	Events() <-chan Event           // returns a constant channel of events related to the device
 	Close() error                   // stops the device and closes the event channel
 }

tun/tun_darwin.go

@@ -213,7 +213,7 @@ func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *NativeTun) Events() chan Event {
+func (tun *NativeTun) Events() <-chan Event {
 	return tun.events
 }
 

tun/tun_freebsd.go

@@ -329,7 +329,7 @@ func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *NativeTun) Events() chan Event {
+func (tun *NativeTun) Events() <-chan Event {
 	return tun.events
 }
 

tun/tun_linux.go

@@ -376,7 +376,7 @@ func (tun *NativeTun) Read(buf []byte, offset int) (n int, err error) {
 	return
 }
 
-func (tun *NativeTun) Events() chan Event {
+func (tun *NativeTun) Events() <-chan Event {
 	return tun.events
 }
 

tun/tun_openbsd.go

@@ -200,7 +200,7 @@ func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *NativeTun) Events() chan Event {
+func (tun *NativeTun) Events() <-chan Event {
 	return tun.events
 }
 

tun/tun_windows.go

@@ -102,7 +102,7 @@ func (tun *NativeTun) File() *os.File {
 	return nil
 }
 
-func (tun *NativeTun) Events() chan Event {
+func (tun *NativeTun) Events() <-chan Event {
 	return tun.events
 }
 

tun/tuntest/tuntest.go

@@ -138,10 +138,10 @@ func (t *chTun) Write(data []byte, offset int) (int, error) {
 
 const DefaultMTU = 1420
 
-func (t *chTun) Flush() error           { return nil }
-func (t *chTun) MTU() (int, error)      { return DefaultMTU, nil }
-func (t *chTun) Name() (string, error)  { return "loopbackTun1", nil }
-func (t *chTun) Events() chan tun.Event { return t.c.events }
+func (t *chTun) Flush() error             { return nil }
+func (t *chTun) MTU() (int, error)        { return DefaultMTU, nil }
+func (t *chTun) Name() (string, error)    { return "loopbackTun1", nil }
+func (t *chTun) Events() <-chan tun.Event { return t.c.events }
 func (t *chTun) Close() error {
 	t.Write(nil, -1)
 	return nil