From 96a488e37ecc8cf0d57b8009eab4ed270617eb18 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Wed, 17 Feb 2021 21:35:33 -0800
Subject: [PATCH] wgengine/router: simplify func normalizeCIDR using netaddr
 method

---
 wgengine/router/router_linux.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/wgengine/router/router_linux.go b/wgengine/router/router_linux.go
index c3724d77f..ec6359e11 100644
--- a/wgengine/router/router_linux.go
+++ b/wgengine/router/router_linux.go
@@ -1020,9 +1020,7 @@ func tsChain(chain string) string {
 // normalizeCIDR returns cidr as an ip/mask string, with the host bits
 // of the IP address zeroed out.
 func normalizeCIDR(cidr netaddr.IPPrefix) string {
-	ncidr := cidr.IPNet()
-	nip := ncidr.IP.Mask(ncidr.Mask)
-	return fmt.Sprintf("%s/%d", nip, cidr.Bits)
+	return cidr.Masked().String()
 }
 
 func cleanup(logf logger.Logf, interfaceName string) {