From 14162b99a46ae155a0474dbc6a1768722f7f6285 Mon Sep 17 00:00:00 2001
From: Danny Kopping <danny@coder.com>
Date: Fri, 12 Dec 2025 14:56:16 +0200
Subject: [PATCH 1/2] fix: use small buffers to make tests more efficient

Signed-off-by: Danny Kopping <danny@coder.com>
---
 conn/batchsize_default.go          | 12 ++++++++++++
 conn/batchsize_testsmall.go        | 16 ++++++++++++++++
 conn/conn.go                       |  4 ----
 device/queueconstants_default.go   |  2 +-
 device/queueconstants_testsmall.go | 21 +++++++++++++++++++++
 5 files changed, 50 insertions(+), 5 deletions(-)
 create mode 100644 conn/batchsize_default.go
 create mode 100644 conn/batchsize_testsmall.go
 create mode 100644 device/queueconstants_testsmall.go

diff --git a/conn/batchsize_default.go b/conn/batchsize_default.go
new file mode 100644
index 000000000..d9e8ad7ed
--- /dev/null
+++ b/conn/batchsize_default.go
@@ -0,0 +1,12 @@
+//go:build !testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+const (
+	IdealBatchSize = 128 // maximum number of packets handled per read and write
+)
diff --git a/conn/batchsize_testsmall.go b/conn/batchsize_testsmall.go
new file mode 100644
index 000000000..524ae3a8c
--- /dev/null
+++ b/conn/batchsize_testsmall.go
@@ -0,0 +1,16 @@
+//go:build testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ *
+ * Modified by Coder for test environments to reduce memory usage.
+ */
+
+package conn
+
+// IdealBatchSize is reduced for tests to minimize memory usage.
+// In production, this is 128 (see batchsize_default.go), but tests don't need
+// the full batch capacity and this significantly reduces memory overhead
+// from wireguard buffer pools (~8MB per connection down to ~256KB).
+const IdealBatchSize = 4
diff --git a/conn/conn.go b/conn/conn.go
index a1f57d2b1..f0221562a 100644
--- a/conn/conn.go
+++ b/conn/conn.go
@@ -15,10 +15,6 @@ import (
 	"strings"
 )
 
-const (
-	IdealBatchSize = 128 // maximum number of packets handled per read and write
-)
-
 // A ReceiveFunc receives at least one packet from the network and writes them
 // into packets. On a successful read it returns the number of elements of
 // sizes, packets, and endpoints that should be evaluated. Some elements of
diff --git a/device/queueconstants_default.go b/device/queueconstants_default.go
index 9749cb789..3bd62ac51 100644
--- a/device/queueconstants_default.go
+++ b/device/queueconstants_default.go
@@ -1,4 +1,4 @@
-//go:build !android && !ios && !windows
+//go:build !android && !ios && !windows && !testsmallbuffers
 
 /* SPDX-License-Identifier: MIT
  *
diff --git a/device/queueconstants_testsmall.go b/device/queueconstants_testsmall.go
new file mode 100644
index 000000000..0ab06c0fb
--- /dev/null
+++ b/device/queueconstants_testsmall.go
@@ -0,0 +1,21 @@
+//go:build testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ *
+ * Modified by Coder for test environments to reduce memory usage.
+ */
+
+package device
+
+import "github.com/tailscale/wireguard-go/conn"
+
+const (
+	QueueStagedSize            = conn.IdealBatchSize
+	QueueOutboundSize          = 64   // Reduced from 1024 for tests
+	QueueInboundSize           = 64   // Reduced from 1024 for tests
+	QueueHandshakeSize         = 64   // Reduced from 1024 for tests
+	MaxSegmentSize             = 2048 // Reduced from 65535 for tests (enough for typical packets)
+	PreallocatedBuffersPerPool = 0    // Disable and allow for infinite memory growth
+)

From bb12dfe22d7ff8127ee642a6829dd2d384c05a98 Mon Sep 17 00:00:00 2001
From: Danny Kopping <danny@coder.com>
Date: Fri, 12 Dec 2025 15:42:29 +0200
Subject: [PATCH 2/2] fix: add !testsmallbuffers to platform-specific build
 tags

Windows, Android, and iOS queueconstants files need to exclude
testsmallbuffers to avoid duplicate constant declarations when
building with -tags=testsmallbuffers.

Signed-off-by: Danny Kopping <danny@coder.com>
---
 device/queueconstants_android.go | 2 ++
 device/queueconstants_ios.go     | 2 +-
 device/queueconstants_windows.go | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/device/queueconstants_android.go b/device/queueconstants_android.go
index bab9625c4..44aaa3ddc 100644
--- a/device/queueconstants_android.go
+++ b/device/queueconstants_android.go
@@ -1,3 +1,5 @@
+//go:build android && !testsmallbuffers
+
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
diff --git a/device/queueconstants_ios.go b/device/queueconstants_ios.go
index acd3cec13..92bc96f3c 100644
--- a/device/queueconstants_ios.go
+++ b/device/queueconstants_ios.go
@@ -1,4 +1,4 @@
-//go:build ios
+//go:build ios && !testsmallbuffers
 
 /* SPDX-License-Identifier: MIT
  *
diff --git a/device/queueconstants_windows.go b/device/queueconstants_windows.go
index 1eee32ba1..3e3f660af 100644
--- a/device/queueconstants_windows.go
+++ b/device/queueconstants_windows.go
@@ -1,3 +1,5 @@
+//go:build !testsmallbuffers
+
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.