fw4: refactor family selection for forwarding rules

Use the common `infer_family()` helper when parsing `forwarding` sections
to simplify the code. Also add some test coverage for the changed code.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/root/usr/share/ucode/fw4.uc b/root/usr/share/ucode/fw4.uc
index 4ca1d79fa00a955e849e3261e409969ba65c47ce..76360c8294e1b49e1e4a3e9a9bfbdff6c8cd194c 100644 (file)
--- a/root/usr/share/ucode/fw4.uc
+++ b/root/usr/share/ucode/fw4.uc
@@ -2099,7 +2099,7 @@ return {
                                proto: { any: true }
                        };
 
-                       f.name ||= `Accept ${fwd.src.any ? "any" : fwd.src.zone.name} to ${fwd.dest.any ? "any" : fwd.dest.zone.name} forwarding`;
+                       f.name ||= `Accept ${fwd.src.any ? "any" : fwd.src.zone.name} to ${fwd.dest.any ? "any" : fwd.dest.zone.name} ${family ? `${this.nfproto(family, true)} ` : ''}forwarding`;
                        f.chain = fwd.src.any ? "forward" : `forward_${fwd.src.zone.name}`;
 
                        if (fwd.dest.any)
@@ -2111,31 +2111,15 @@ return {
                };
 
 
-               let family = fwd.family;
-
                /* inherit family restrictions from related zones */
-               if (family === 0 || family === null) {
-                       let f1 = fwd.src.zone ? fwd.src.zone.family : 0;
-                       let f2 = fwd.dest.zone ? fwd.dest.zone.family : 0;
-
-                       if (f1 && f2 && f1 != f2) {
-                               this.warn_section(data,
-                                       `references src ${fwd.src.zone.name} restricted to ${this.nfproto(f1, true)} and dest ${fwd.dest.zone.name} restricted to ${this.nfproto(f2, true)}, ignoring forwarding`);
-
-                               return;
-                       }
-                       else if (f1) {
-                               this.warn_section(data,
-                                       `inheriting ${this.nfproto(f1, true)} restriction from src ${fwd.src.zone.name}`);
-
-                               family = f1;
-                       }
-                       else if (f2) {
-                               this.warn_section(data,
-                                       `inheriting ${this.nfproto(f2, true)} restriction from dest ${fwd.dest.zone.name}`);
+               let family = infer_family(fwd.family, [
+                       fwd.src?.zone, "source zone",
+                       fwd.dest?.zone, "destination zone"
+               ]);
 
-                               family = f2;
-                       }
+               if (type(family) == "string") {
+                       this.warn_section(data, `${family}, skipping`);
+                       return;
                }
 
                add_rule(family, fwd);

diff --git a/tests/04_forwardings/01_family_selections b/tests/04_forwardings/01_family_selections
new file mode 100644 (file)
index 0000000..c7b0345
--- /dev/null
+++ b/tests/04_forwardings/01_family_selections
@@ -0,0 +1,246 @@
+Test that the zone family is honoured when setting up inter-zone forwarding rules.
+
+-- Testcase --
+{%
+       include("./root/usr/share/firewall4/main.uc", {
+               getenv: function(varname) {
+                       switch (varname) {
+                       case 'ACTION':
+                               return 'print';
+                       }
+               }
+       })
+%}
+-- End --
+
+-- File uci/helpers.json --
+{}
+-- End --
+
+-- File uci/firewall.json --
+{
+       "zone": [
+               {
+                       "name": "wanA",
+                       "device": [ "eth0" ],
+                       "auto_helper": 0
+               },
+
+               {
+                       "name": "wanB",
+                       "device": [ "eth1" ],
+                       "auto_helper": 0
+               },
+
+               {
+                       "name": "lan",
+                       "device": [ "eth2" ],
+                       "auto_helper": 0
+               }
+       ],
+
+       "forwarding": [
+               {
+                       ".description": "This should only allow IPv6 forwarding from lan to wanA",
+                       "src": "lan",
+                       "dest": "wanA",
+                       "family": "IPv6"
+               },
+
+               {
+                       ".description": "This should only allow IPv4 forwarding from lan to wanB",
+                       "src": "lan",
+                       "dest": "wanB",
+                       "family": "IPv4"
+               }
+       ]
+}
+-- End --
+
+-- Expect stdout --
+table inet fw4
+flush table inet fw4
+
+table inet fw4 {
+       #
+       # Set definitions
+       #
+
+
+       #
+       # Defines
+       #
+
+       define wanA_devices = { "eth0" }
+       define wanB_devices = { "eth1" }
+       define lan_devices = { "eth2" }
+
+       #
+       # User includes
+       #
+
+       include "/etc/nftables.d/*.nft"
+
+
+       #
+       # Filter rules
+       #
+
+       chain input {
+               type filter hook input priority filter; policy drop;
+
+               iifname "lo" accept comment "!fw4: Accept traffic from loopback"
+
+               ct state established,related accept comment "!fw4: Allow inbound established and related flows"
+               iifname "eth0" jump input_wanA comment "!fw4: Handle wanA IPv4/IPv6 input traffic"
+               iifname "eth1" jump input_wanB comment "!fw4: Handle wanB IPv4/IPv6 input traffic"
+               iifname "eth2" jump input_lan comment "!fw4: Handle lan IPv4/IPv6 input traffic"
+       }
+
+       chain forward {
+               type filter hook forward priority filter; policy drop;
+
+               ct state established,related accept comment "!fw4: Allow forwarded established and related flows"
+               iifname "eth0" jump forward_wanA comment "!fw4: Handle wanA IPv4/IPv6 forward traffic"
+               iifname "eth1" jump forward_wanB comment "!fw4: Handle wanB IPv4/IPv6 forward traffic"
+               iifname "eth2" jump forward_lan comment "!fw4: Handle lan IPv4/IPv6 forward traffic"
+       }
+
+       chain output {
+               type filter hook output priority filter; policy drop;
+
+               oifname "lo" accept comment "!fw4: Accept traffic towards loopback"
+
+               ct state established,related accept comment "!fw4: Allow outbound established and related flows"
+               oifname "eth0" jump output_wanA comment "!fw4: Handle wanA IPv4/IPv6 output traffic"
+               oifname "eth1" jump output_wanB comment "!fw4: Handle wanB IPv4/IPv6 output traffic"
+               oifname "eth2" jump output_lan comment "!fw4: Handle lan IPv4/IPv6 output traffic"
+       }
+
+       chain handle_reject {
+               meta l4proto tcp reject with tcp reset comment "!fw4: Reject TCP traffic"
+               reject with icmpx type port-unreachable comment "!fw4: Reject any other traffic"
+       }
+
+       chain input_wanA {
+               jump drop_from_wanA
+       }
+
+       chain output_wanA {
+               jump drop_to_wanA
+       }
+
+       chain forward_wanA {
+               jump drop_to_wanA
+       }
+
+       chain accept_to_wanA {
+               oifname "eth0" counter accept comment "!fw4: accept wanA IPv4/IPv6 traffic"
+       }
+
+       chain drop_from_wanA {
+               iifname "eth0" counter drop comment "!fw4: drop wanA IPv4/IPv6 traffic"
+       }
+
+       chain drop_to_wanA {
+               oifname "eth0" counter drop comment "!fw4: drop wanA IPv4/IPv6 traffic"
+       }
+
+       chain input_wanB {
+               jump drop_from_wanB
+       }
+
+       chain output_wanB {
+               jump drop_to_wanB
+       }
+
+       chain forward_wanB {
+               jump drop_to_wanB
+       }
+
+       chain accept_to_wanB {
+               oifname "eth1" counter accept comment "!fw4: accept wanB IPv4/IPv6 traffic"
+       }
+
+       chain drop_from_wanB {
+               iifname "eth1" counter drop comment "!fw4: drop wanB IPv4/IPv6 traffic"
+       }
+
+       chain drop_to_wanB {
+               oifname "eth1" counter drop comment "!fw4: drop wanB IPv4/IPv6 traffic"
+       }
+
+       chain input_lan {
+               jump drop_from_lan
+       }
+
+       chain output_lan {
+               jump drop_to_lan
+       }
+
+       chain forward_lan {
+               meta nfproto ipv6 jump accept_to_wanA comment "!fw4: Accept lan to wanA IPv6 forwarding"
+               meta nfproto ipv4 jump accept_to_wanB comment "!fw4: Accept lan to wanB IPv4 forwarding"
+               jump drop_to_lan
+       }
+
+       chain drop_from_lan {
+               iifname "eth2" counter drop comment "!fw4: drop lan IPv4/IPv6 traffic"
+       }
+
+       chain drop_to_lan {
+               oifname "eth2" counter drop comment "!fw4: drop lan IPv4/IPv6 traffic"
+       }
+
+
+       #
+       # NAT rules
+       #
+
+       chain dstnat {
+               type nat hook prerouting priority dstnat; policy accept;
+       }
+
+       chain srcnat {
+               type nat hook postrouting priority srcnat; policy accept;
+       }
+
+
+       #
+       # Raw rules (notrack & helper)
+       #
+
+       chain raw_prerouting {
+               type filter hook prerouting priority raw; policy accept;
+       }
+
+       chain raw_output {
+               type filter hook output priority raw; policy accept;
+       }
+
+
+       #
+       # Mangle rules
+       #
+
+       chain mangle_prerouting {
+               type filter hook prerouting priority mangle; policy accept;
+       }
+
+       chain mangle_postrouting {
+               type filter hook postrouting priority mangle; policy accept;
+       }
+
+       chain mangle_input {
+               type filter hook input priority mangle; policy accept;
+       }
+
+       chain mangle_output {
+               type filter hook output priority mangle; policy accept;
+       }
+
+       chain mangle_forward {
+               type filter hook forward priority mangle; policy accept;
+       }
+}
+-- End --