From 753b5776963ed2cbb6980a1f678565469868cf0f Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Sat, 4 Mar 2023 15:32:38 +0000
Subject: [PATCH] Limit echo on a per source basis

---
 .../networking/templates/default/nftables.conf.erb | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/cookbooks/networking/templates/default/nftables.conf.erb b/cookbooks/networking/templates/default/nftables.conf.erb
index 63bcb908b..13e070569 100644
--- a/cookbooks/networking/templates/default/nftables.conf.erb
+++ b/cookbooks/networking/templates/default/nftables.conf.erb
@@ -30,6 +30,16 @@ table inet filter {
     flags dynamic
   }
 
+  set limit-icmp-echo-ip {
+    type ipv4_addr
+    flags dynamic
+  }
+
+  set limit-icmp-echo-ip6 {
+    type ipv6_addr
+    flags dynamic
+  }
+
 <%- node[:networking][:firewall][:sets].each do |set| %>
   set <%= set %> {
 <%- if set.end_with?("-ip") %>
@@ -61,11 +71,11 @@ table inet filter {
     ct state { established, related } accept
 
     icmp type { destination-unreachable } accept
-    icmp type { echo-request } limit rate 1/second accept
+    icmp type { echo-request } add @limit-icmp-echo-ip { ip saddr limit rate 1/second } accept
     icmp type { echo-request } drop
 
     icmpv6 type { nd-neighbor-solicit, nd-neighbor-advert, nd-router-solicit, nd-router-advert } accept
-    icmpv6 type { echo-request } limit rate 1/second accept
+    icmpv6 type { echo-request } add @limit-icmp-echo-ip6 { ip6 saddr limit rate 1/second } accept
     icmpv6 type { echo-request } drop
 
     meta l4proto { icmp, icmpv6 } jump log-and-drop
-- 
2.39.5