From cecb41515d780213fd6b37bd04686f5296edf84c Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josh@tailscale.com>
Date: Mon, 25 Jan 2021 09:35:35 -0800
Subject: [PATCH] device: serialize access to IpcSetOperation
Interleaves IpcSetOperations would spell trouble.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
---
device/device.go | 1 +
device/uapi.go | 3 +++
2 files changed, 4 insertions(+)
diff --git a/device/device.go b/device/device.go
index 58e996f..5d11766 100644
--- a/device/device.go
+++ b/device/device.go
@@ -23,6 +23,7 @@ type Device struct {
isUp AtomicBool // device is (going) up
isClosed AtomicBool // device is closed? (acting as guard)
log *Logger
+ ipcSetMu sync.Mutex // serializes UAPI set operations
// synchronized resources (locks acquired in order)
diff --git a/device/uapi.go b/device/uapi.go
index bf38459..c1ddb38 100644
--- a/device/uapi.go
+++ b/device/uapi.go
@@ -121,6 +121,9 @@ func (device *Device) IpcGetOperation(w io.Writer) error {
// IpcSetOperation implements the WireGuard configuration protocol "set" operation.
// See https://www.wireguard.com/xplatform/#configuration-protocol for details.
func (device *Device) IpcSetOperation(r io.Reader) (err error) {
+ device.ipcSetMu.Lock()
+ defer device.ipcSetMu.Unlock()
+
defer func() {
if err != nil {
device.log.Error.Println(err)