Generalise configuration of firewall sets

[chef.git] / cookbooks / networking / templates / default / nftables.conf.erb

diff --git a/cookbooks/networking/templates/default/nftables.conf.erb b/cookbooks/networking/templates/default/nftables.conf.erb
index 65d090db31d3cd6ed2b19b3ded337c516402e745..74d104fadae5cf9e38f7f698bd148c8f3d9175c3 100644 (file)
--- a/cookbooks/networking/templates/default/nftables.conf.erb
+++ b/cookbooks/networking/templates/default/nftables.conf.erb
@@ -1,48 +1,70 @@
 #!/usr/sbin/nft -f
 
+<% unless @interfaces.empty? -%>
 define external-interfaces = { <%= @interfaces.sort.uniq.join(", ") %> }
+<% end -%>
 
-define ip-private-addresses = { 10.0.0.0/8, 127.0.0.0/8, 169.254.0.0/16, 172.16.0.0/12, 192.0.2.0/24, 192.168.0.0/16 }
+define ip-private-addresses = { 0.0.0.0, 10.0.0.0/8, 127.0.0.0/8, 169.254.0.0/16, 172.16.0.0/12, 192.0.2.0/24, 192.168.0.0/16 }
+define ip-multicast-addresses = { 224.0.0.0/4 }
 define ip6-private-addresses = { 2001:db8::/32, fc00::/7 }
+define ip6-multicast-addresses = { ff00::/8 }
 
-flush ruleset
-
-table inet filter {
+table inet chef-filter {
   set ip-osm-addresses {
     type ipv4_addr
-<%- unless Array(@hosts["inet"]).empty? %>
+<% unless Array(@hosts["inet"]).empty? -%>
     elements = { <%= Array(@hosts["inet"]).sort.join(", ") %> }
-<%- end %>
+<% end -%>
   }
 
   set ip6-osm-addresses {
     type ipv6_addr
-<%- unless Array(@hosts["inet"]).empty? %>
+<% unless Array(@hosts["inet"]).empty? -%>
     elements = { <%= Array(@hosts["inet6"]).sort.join(", ") %> }
-<%- end %>
+<% end -%>
   }
 
-  set ip-blacklist {
+  set ip-blocklist {
     type ipv4_addr
-    flags dynamic
+    flags interval
   }
 
-  set ip6-blacklist {
+  set ip6-blocklist {
     type ipv6_addr
-    flags dynamic
+    flags interval
   }
 
-<%- node[:networking][:firewall][:sets].each do |set| %>
-  set <%= set %> {
-<%- if set.end_with?("-ip") %>
+  set ratelimit-icmp-echo-ip {
     type ipv4_addr
-<%- elsif set.end_with?("-ip6") %>
+    flags dynamic
+    timeout 120s
+  }
+
+  set ratelimit-icmp-echo-ip6 {
     type ipv6_addr
-<%- end %>
     flags dynamic
+    timeout 120s
+  }
+
+<% node[:networking][:firewall][:sets].each do |set| -%>
+  set <%= set[:name] %> {
+    type <%= set[:type] %>
+<% if set[:flags] -%>
+    flags <%= set[:flags].join(", ") %>
+<% end -%>
+<% if set[:timeout] -%>
+    timeout <%= set[:timeout] %>s
+<% end -%>
+  }
+
+<% end -%>
+
+<% node[:networking][:firewall][:helpers].each do |helper| -%>
+  ct helper <%= helper[:name] %> {
+    type "<%= helper[:helper] %>" protocol <%= helper[:protocol] %>
   }
 
-<%- end %>
+<% end -%>
   chain log-and-drop {
     limit rate 1/second log
     drop
@@ -54,36 +76,53 @@ table inet filter {
   }
 
   chain incoming {
-    ip saddr { $ip-private-addresses } jump log-and-drop
-    ip6 saddr { $ip6-private-addresses } jump log-and-drop
+<% if node[:networking][:firewall][:allowlist].empty? -%>
+    ip saddr { $ip-private-addresses, $ip-multicast-addresses } jump log-and-drop
+<% else -%>
+    ip saddr { $ip-private-addresses, $ip-multicast-addresses } ip saddr != { <%= node[:networking][:firewall][:allowlist].sort.join(", ") %> } jump log-and-drop
+<% end -%>
+    ip6 saddr { $ip6-private-addresses, $ip6-multicast-addresses } jump log-and-drop
 
-    ip saddr @ip-blacklist jump log-and-drop
-    ip6 saddr @ip6-blacklist jump log-and-drop
+    ip saddr @ip-blocklist jump log-and-drop
+    ip6 saddr @ip6-blocklist jump log-and-drop
 
-    ct state { established, related } accept
+    icmp type { echo-request } update @ratelimit-icmp-echo-ip { ip saddr limit rate 1/second } accept
+    icmp type { echo-request } drop
 
-    icmp type { destination-unreachable } accept
     icmpv6 type { nd-neighbor-solicit, nd-neighbor-advert, nd-router-solicit, nd-router-advert } accept
+    icmpv6 type { echo-request } update @ratelimit-icmp-echo-ip6 { ip6 saddr limit rate 1/second } accept
+    icmpv6 type { echo-request } drop
 
-    icmp type { echo-request } limit rate 1/second accept
-    icmpv6 type { echo-request } limit rate 1/second accept
+    ct state { established, related } accept
 
     meta l4proto { icmp, icmpv6 } jump log-and-drop
 
-<%- node[:networking][:firewall][:incoming].uniq.each do |rule| %>
+    tcp flags & (fin|syn|rst|psh|ack|urg) == fin|psh|urg jump log-and-drop
+    tcp flags & (fin|syn|rst|psh|ack|urg) == 0x0 jump log-and-drop
+    tcp flags & (syn|rst) == syn|rst jump log-and-drop
+    tcp flags & (fin|rst) == fin|rst jump log-and-drop
+    tcp flags & (fin|syn) == fin|syn jump log-and-drop
+    tcp flags & (fin|psh|ack) == fin|psh jump log-and-drop
+    tcp sport 0 tcp flags & (fin|syn|rst|ack) == syn jump log-and-drop
+
+<% node[:networking][:firewall][:incoming].uniq.each do |rule| -%>
     <%= rule %>
-<%- end %>
+<% end -%>
 
     jump log-and-drop
   }
 
   chain outgoing {
+<% if node[:networking][:firewall][:allowlist].empty? -%>
     ip daddr { $ip-private-addresses } jump log-and-drop
+<% else -%>
+    ip daddr { $ip-private-addresses } ip daddr != { <%= node[:networking][:firewall][:allowlist].sort.join(", ") %> } jump log-and-drop
+<% end -%>
     ip6 daddr { $ip6-private-addresses } jump log-and-drop
 
-<%- node[:networking][:firewall][:outgoing].each do |rule| %>
+<% node[:networking][:firewall][:outgoing].each do |rule| -%>
     <%= rule %>
-<%- end %>
+<% end -%>
 
     accept
   }
@@ -91,7 +130,9 @@ table inet filter {
   chain input {
     type filter hook input priority filter;
 
-    iif { $external-interfaces } jump incoming
+<% unless @interfaces.empty? -%>
+    iifname { $external-interfaces } jump incoming
+<% end -%>
 
     accept
   }
@@ -99,8 +140,10 @@ table inet filter {
   chain forward {
     type filter hook forward priority filter;
 
-    iif { $external-interfaces } jump incoming
-    oif { $external-interfaces } jump outgoing
+<% unless @interfaces.empty? -%>
+    iifname { $external-interfaces } jump incoming
+    oifname { $external-interfaces } jump outgoing
+<% end -%>
 
     accept
   }
@@ -108,22 +151,24 @@ table inet filter {
   chain output {
     type filter hook output priority filter;
 
-    oif { $external-interfaces } jump outgoing
+<% unless @interfaces.empty? -%>
+    oifname { $external-interfaces } jump outgoing
+<% end -%>
 
     accept
   }
 }
-<%- if node[:roles].include?("gateway") %>
+<% if node[:roles].include?("gateway") -%>
 
-table ip nat {
+table ip chef-nat {
   chain postrouting {
     type nat hook postrouting priority srcnat;
 
-<%- node.interfaces(:role => :external).each do |external| %>
-<%- node.interfaces(:role => :internal).each do |internal| %>
-    oif { < %= external[:interface] %> } ip saddr { <%= internal[:network] %>/<%= internal[:prefix] %> } snat <%= external[:address] %>
-<%- end %>
-<%- end %>
+<% node.interfaces(:role => :external, :family => :inet).each do |external| -%>
+<% node.interfaces(:role => :internal, :family => :inet).each do |internal| -%>
+    oifname { <%= external[:interface] %> } ip saddr { <%= internal[:network] %>/<%= internal[:prefix] %> } snat <%= external[:address] %>
+<% end -%>
+<% end -%>
   }
 }
-<%- end %>
+<% end -%>