From 38be6c13f76e893cf47636257071b440dec0c5b2 Mon Sep 17 00:00:00 2001
From: Robert Günzler <r@gnzler.io>
Date: Sun, 7 Sep 2025 17:32:13 +0200
Subject: initial commit
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Signed-off-by: Robert Günzler <r@gnzler.io>
---
 bundles/firewall/files/etc/nftables.d/00-basic.nft | 59 ++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 bundles/firewall/files/etc/nftables.d/00-basic.nft

(limited to 'bundles/firewall/files/etc/nftables.d/00-basic.nft')

diff --git a/bundles/firewall/files/etc/nftables.d/00-basic.nft b/bundles/firewall/files/etc/nftables.d/00-basic.nft
new file mode 100644
index 0000000..493ab38
--- /dev/null
+++ b/bundles/firewall/files/etc/nftables.d/00-basic.nft
@@ -0,0 +1,59 @@
+#!/usr/sbin/nft -f
+# vim: set ts=4 sw=4:
+table inet filter {
+	chain input {
+		iifname lo accept \
+		comment "Accept any localhost traffic"
+
+		ct state { established, related } accept \
+		comment "Accept traffic originated from us"
+
+		ct state invalid drop \
+		comment "Drop invalid connections"
+
+		tcp dport 113 reject with icmpx type port-unreachable \
+		comment "Reject AUTH to make it fail fast"
+
+		# ICMPv4
+
+		ip protocol icmp icmp type {
+			echo-reply,  # type 0
+			destination-unreachable,  # type 3
+			echo-request,  # type 8
+			time-exceeded,  # type 11
+			parameter-problem,  # type 12
+		} accept \
+		comment "Accept ICMP"
+
+		# ICMPv6
+
+		icmpv6 type {
+			destination-unreachable,  # type 1
+			packet-too-big,  # type 2
+			time-exceeded,  # type 3
+			parameter-problem,  # type 4
+			echo-request,  # type 128
+			echo-reply,  # type 129
+		} accept \
+		comment "Accept basic IPv6 functionality"
+
+		icmpv6 type {
+			nd-router-solicit,  # type 133
+			nd-router-advert,  # type 134
+			nd-neighbor-solicit,  # type 135
+			nd-neighbor-advert,  # type 136
+		} ip6 hoplimit 255 accept \
+		comment "Allow IPv6 SLAAC"
+
+		icmpv6 type {
+			mld-listener-query,  # type 130
+			mld-listener-report,  # type 131
+			mld-listener-reduction,  # type 132
+			mld2-listener-report,  # type 143
+		} ip6 saddr fe80::/10 accept \
+		comment "Allow IPv6 multicast listener discovery on link-local"
+
+		ip6 saddr fe80::/10 udp sport 547 udp dport 546 accept \
+		comment "Accept DHCPv6 replies from IPv6 link-local addresses"
+	}
+}
-- 
cgit 1.4.1