chore: remove all IPv6 functionality

tasks/firewall.yaml

@@ -1,2 +1,142 @@
 ---
-# Configure firewall
+
+# deploy ipv4 iptable rules
+- name: "firewall - ipv4 rules"
+  ansible.builtin.copy:
+    dest: "/etc/iptables/rules-save"
+    mode: "0600"
+    owner: "root"
+    group: "root"
+    content: |
+      *nat
+      :PREROUTING ACCEPT [0:0]
+      :INPUT ACCEPT [0:0]
+      :OUTPUT ACCEPT [0:0]
+      :POSTROUTING ACCEPT [0:0]
+      # NAT masquerade from LAN to WAN
+      -A POSTROUTING -o {{ wan_interface }} -j MASQUERADE
+      {% for forward in nat_port_forwards %}
+      # {{ forward.name }}
+      -A PREROUTING -i {{ wan_interface }} -p {{ forward.protocol | default('tcp') }} --dport {{ forward.port }} -j DNAT --to-destination {{ forward.dst }}:{{ forward.port }}
+      {% endfor %}
+      COMMIT
+
+      *filter
+      :INPUT DROP [0:0]
+      :FORWARD DROP [0:0]
+      :OUTPUT ACCEPT [0:0]
+      # Allow established/related
+      -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
+      -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
+      # Allow loopback
+      -A INPUT -i lo -j ACCEPT
+      # Allow LAN management access
+      -A INPUT -i {{ lan_interface }} -j ACCEPT
+      # Allow forwarding from LAN to anywhere
+      -A FORWARD -i {{ lan_interface }} -o {{ wan_interface }} -j ACCEPT
+      {% for forward in nat_port_forwards %}
+      # {{ forward.name }}
+      -A FORWARD -i {{ wan_interface }} -o {{ lan_interface }} -d {{ forward.dst }} -p {{ forward.protocol | default('tcp') }} --dport {{ forward.port }} -j ACCEPT
+      {% endfor %}
+      COMMIT
+  notify: "restart iptables"
+  when: "ipv4_enabled"
+
+
+# deploy ipv6 iptable rules
+- name: "firewall - deploy ipv6 rules"
+  ansible.builtin.copy:
+    dest: "/etc/ip6tables/rules-save"
+    mode: "0600"
+    owner: "root"
+    group: "root"
+    content: |
+      *filter
+      :INPUT DROP [0:0]
+      :FORWARD DROP [0:0]
+      :OUTPUT ACCEPT [0:0]
+      # Allow established/related
+      -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
+      -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
+      # Allow loopback
+      -A INPUT -i lo -j ACCEPT
+      # Allow LAN management access
+      -A INPUT -i {{ lan_interface }} -j ACCEPT
+      # Allow ICMPv6 (required for NDP/RA)
+      -A INPUT -p ipv6-icmp -j ACCEPT
+      -A FORWARD -p ipv6-icmp -j ACCEPT
+      # Allow forwarding from LAN to anywhere
+      -A FORWARD -i {{ lan_interface }} -o {{ wan_interface }} -j ACCEPT
+      COMMIT
+  notify: "restart ip6tables"
+  when: "ipv6_enabled"
+
+# remove iptables rules when disabled
+- name: "firewall - remove ipv4 rules"
+  ansible.builtin.file:
+    path: "/etc/iptables/rules-save"
+    state: "absent"
+  notify: "restart iptables"
+  when: "not ipv4_enabled"
+
+# remove ip6tables rules when disabled
+- name: "firewall - remove ipv6 rules"
+  ansible.builtin.file:
+    path: "/etc/ip6tables/rules-save"
+    state: "absent"
+  notify: "restart ip6tables"
+  when: "not ipv6_enabled"
+
+
+# load nf_conntrack module
+- name: "firewall - load nf_conntrack module"
+  community.general.modprobe:
+    name: "nf_conntrack"
+    state: "present"
+  when: "ipv4_enabled or ipv6_enabled"
+
+# configure nf_conntrack hashsize
+- name: "firewall - configure nf_conntrack hashsize"
+  ansible.builtin.lineinfile:
+    path: "/etc/modprobe.d/nf_conntrack.conf"
+    line: "options nf_conntrack hashsize=16384"
+    create: true
+    mode: "0644"
+    owner: "root"
+    group: "root"
+  when: "ipv4_enabled or ipv6_enabled"
+
+# load nf_conntrack at boot
+- name: "firewall - load nf_conntrack at boot"
+  ansible.builtin.lineinfile:
+    path: "/etc/modules"
+    line: "nf_conntrack"
+    create: true
+    mode: "0644"
+    owner: "root"
+    group: "root"
+  when: "ipv4_enabled or ipv6_enabled"
+
+# set nf_conntrack hashsize at runtime
+- name: "firewall - set nf_conntrack hashsize runtime"
+  ansible.builtin.shell:
+    cmd: "echo 16384 > /sys/module/nf_conntrack/parameters/hashsize"
+  changed_when: false
+  when: "ipv4_enabled or ipv6_enabled"
+
+# configure nf_conntrack sysctl settings
+- name: "firewall - configure conntrack sysctl settings"
+  ansible.posix.sysctl:
+    name: "{{ item.name }}"
+    value: "{{ item.value }}"
+    state: "present"
+    sysctl_file: "/etc/sysctl.conf"
+    reload: false
+  loop:
+    - name: "net.netfilter.nf_conntrack_max"
+      value: "16384"
+    - name: "net.netfilter.nf_conntrack_tcp_timeout_established"
+      value: "3600"
+    - name: "net.netfilter.nf_conntrack_generic_timeout"
+      value: "120"
+  when: "ipv4_enabled or ipv6_enabled"