example config for ppoe router

hard cases make bad law

nat.nft

@@ -0,0 +1,16 @@
+#!/usr/bin/nft -f
+
+flush ruleset
+
+table ip nat {
+	chain prerouting {
+		type nat hook prerouting priority 0; policy accept;
+	}
+
+	# for all packets to WAN, after routing, replace source address with primary IP of WAN interface
+	chain postrouting {
+		type nat hook postrouting priority 100; policy accept;
+		oifname "ppp0" masquerade
+	}
+}
+

rotuer.nix

@@ -0,0 +1,215 @@
+# This is not part of Liminix per se. This is my "scratchpad"
+# configuration for the device I'm testing with.
+#
+# Parts of it do do things that Liminix eventually needs to do, but
+# don't look in here for solutions - just for identifying the
+# problems.
+
+
+{ config, pkgs, lib, ... } :
+let
+  secrets = import ./rotuer-secrets.nix;
+  inherit (pkgs.liminix.networking)
+    address
+    bridge
+    dnsmasq
+    hostapd
+    interface
+    pppoe
+    route;
+  inherit (pkgs.liminix.services) oneshot longrun bundle target;
+  inherit (pkgs)
+    waitup
+    serviceFns
+    iptables;
+in rec {
+  services.loopback =
+    let iface = interface { type = "loopback"; device = "lo";};
+    in bundle {
+      name = "loopback";
+      contents = [
+        (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
+        (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
+      ];
+    };
+
+  boot = {
+    tftp = {
+      enable = true;
+      serverip = "10.0.0.1";
+      ipaddr = "10.0.0.8";
+    };
+  };
+
+  imports = [
+    ./modules/wlan.nix
+    ./modules/phram.nix
+  ];
+
+  kernel = {
+    config = {
+      PPP = "y";
+      PPP_BSDCOMP = "y";
+      PPP_DEFLATE = "y";
+      PPP_ASYNC = "y";
+      PPP_SYNC_TTY = "y";
+      BRIDGE = "y";
+
+      NETFILTER_XT_MATCH_CONNTRACK = "y";
+
+      IP6_NF_IPTABLES= "y";
+      IP_NF_IPTABLES= "y";
+      IP_NF_NAT = "y";
+      IP_NF_TARGET_MASQUERADE = "y";
+      NETFILTER = "y";
+      NETFILTER_ADVANCED = "y";
+      NETFILTER_XTABLES = "y";
+
+      NFT_COMPAT = "y";
+      NFT_CT = "y";
+      NFT_LOG = "y";
+      NFT_MASQ = "y";
+      NFT_NAT = "y";
+      NFT_REJECT = "y";
+      NFT_REJECT_INET = "y";
+
+      NF_CONNTRACK = "y";
+      NF_NAT = "y";
+      NF_NAT_MASQUERADE  = "y";
+      NF_TABLES= "y";
+      NF_TABLES_INET = "y";
+      NF_TABLES_IPV4 = "y";
+      NF_TABLES_IPV6 = "y";
+    };
+  };
+
+  services.lan =
+    let iface = interface {
+          type = "bridge";
+          device = "lan";
+        };
+    in address iface {
+      family = "inet4"; address ="10.8.0.1"; prefixLength = 16;
+    };
+
+  services.wireless = interface {
+    type = "hardware";
+    device = "wlan0";
+    dependencies = [ config.services.wlan_module ];
+  };
+
+  services.wired = interface {
+    type = "hardware";
+    device = "eth0";
+    primary = services.lan;
+  };
+
+  services.hostap = hostapd (services.wireless) {
+    params = {
+      ssid = "liminix";
+      country_code = "GB";
+      hw_mode="g";
+      channel = "2";
+      wmm_enabled = 1;
+      ieee80211n = 1;
+      inherit (secrets) wpa_passphrase;
+      auth_algs = 1; # 1=wpa2, 2=wep, 3=both
+      wpa = 2;       # 1=wpa, 2=wpa2, 3=both
+      wpa_key_mgmt = "WPA-PSK";
+      wpa_pairwise = "TKIP CCMP";   # auth for wpa (may not need this?)
+      rsn_pairwise = "CCMP";        # auth for wpa2
+    };
+  };
+
+  services.bridgewlan =
+    let waitup-wlan = longrun {
+          name = "waitup-wlan0";
+          run = "${waitup}/bin/waitup wlan0 10";
+          notification-fd = 10;
+          dependencies = [ services.wireless services.hostap ];
+        };
+    in oneshot {
+      name = "add-wlan-to-bridge";
+      up = "ip link set dev ${services.wireless.device} master ${services.lan.device}";
+      down = "ip link set dev ${services.wireless.device} nomaster";
+      dependencies = [ waitup-wlan  ];
+    };
+
+  users.dnsmasq = {
+    uid = 51; gid= 51; gecos = "DNS/DHCP service user";
+    dir = "/run/dnsmasq";
+    shell = "/bin/false";
+  };
+  groups.dnsmasq = {
+    gid = 51; usernames = ["dnsmasq"];
+  };
+  groups.system.usernames = ["dnsmasq"];
+
+  services.dns =
+    dnsmasq {
+      resolvconf = services.resolvconf;
+      interface = services.lan;
+      ranges = ["10.8.0.10,10.8.0.240"];
+      domain = "fake.liminix.org";
+    };
+
+  services.wan =
+    let iface = interface { type = "hardware"; device = "eth1"; };
+    in pppoe iface {
+      ppp-options = [
+        "debug" "+ipv6" "noauth"
+        "name" secrets.l2tp.name
+        "password" secrets.l2tp.password
+      ];
+    };
+
+  services.resolvconf = oneshot rec {
+    dependencies = [ services.wan ];
+    name = "resolvconf";
+    up = ''
+      . ${serviceFns}
+      ( cd `mkoutputs ${name}`; umask 0027
+       echo "nameserver $(output ${services.wan} ns1)" > resolv.conf
+       echo "nameserver $(output ${services.wan} ns2)" >> resolv.conf
+      )
+    '';
+    down = ''
+      rm -rf /run/service-state/${name}/
+    '';
+  };
+
+  services.defaultroute4 = route {
+    name = "defaultroute";
+    via = "$(output ${services.wan} address)";
+    target = "default";
+    dependencies = [ services.wan ];
+  };
+
+  services.packet_forwarding =
+    let filename = "/proc/sys/net/ipv4/conf/all/forwarding";
+    in oneshot {
+      name = "let-the-ip-flow";
+      up = ''
+        ${pkgs.nftables}/bin/nft -f ${./nat.nft}
+        echo 1 > ${filename}
+      '';
+      down = "echo 0 > ${filename}";
+    };
+
+  services.default = target {
+    name = "default";
+    contents = with services; [
+      loopback
+      wired
+      wireless
+      lan
+      hostap
+      defaultroute4
+      packet_forwarding
+      dns
+      bridgewlan
+      resolvconf
+    ];
+  };
+  defaultProfile.packages = with pkgs;  [ nftables strace tcpdump ] ;
+}