nixos/modules/hostapd: fork and expand hostapd

1 files changed, 552 insertions, 0 deletions

diff --git a/nixos/modules/hostapd.nix b/nixos/modules/hostapd.nix
new file mode 100644
index 0000000..0ca66d0
--- /dev/null
+++ b/nixos/modules/hostapd.nix
@@ -0,0 +1,552 @@
+{ config, lib, pkgs, utils, ... }:
+
+# TODO:
+#
+# asserts
+#   ensure that the nl80211 module is loaded/compiled in the kernel
+#   wpa_supplicant and hostapd on the same wireless interface doesn't make any sense
+
+with builtins;
+with lib;
+
+let
+
+  cfg = config.networking.hostapd;
+
+  options_bss = {
+
+      ssid = mkOption {
+        type = types.str;
+        default = "nixos";
+        example = "mySpecialSSID";
+        description = "SSID to be used in IEEE 802.11 management frames.";
+      };
+
+      wpa = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Enable WPA (IEEE 802.11i/D3.0) to authenticate with the access point.
+        '';
+      };
+
+      wpa3 = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Use WPA3 instead of WPA2 for authentication. This changes the key
+          management from WPA_PSK to SAE.
+        '';
+      };
+
+      wpaPassphrase = mkOption {
+        type = with types; nullOr str;
+        default = null;
+        example = "any_64_char_string";
+        description = ''
+          WPA-PSK (pre-shared-key) passphrase. Clients will need this
+          passphrase to associate with this access point.
+          Warning: This passphrase will get put into a world-readable file in
+          the Nix store! You should use wpaPskFile in most cases.
+        '';
+      };
+
+      wpaPskFile = mkOption {
+        type = with types; nullOr str;
+        default = null;
+        example = "/etc/hostapd.wpa_psk";
+        description = ''
+          Optionally, WPA PSKs can be read from a separate text file (containing
+          list of (PSK,MAC address) pairs. This allows more than one PSK to be
+          configured.  Use absolute path name to make sure that the files can be
+          read on SIGHUP configuration reloads.
+          This is higly suggested to be used over wpaPassphrase as it won't save
+          your password to the Nix store!
+        '';
+      };
+
+  };
+
+  options_interface = options_bss // {
+
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Enable putting a wireless interface into infrastructure mode,
+          allowing other wireless devices to associate with the wireless
+          interface and do wireless networking. A simple access point will
+          <option>enable hostapd.<name>.wpa</option>, set
+          <option>hostapd.<name>.wpaPassphrase</option>, and
+          <option>hostapd.<name>.ssid</option>, as well as DHCP on the wireless
+          interface to provide IP addresses to the associated stations, and
+          NAT (from the wireless interface to an upstream interface).
+        '';
+      };
+
+      group = mkOption {
+        default = "wheel";
+        example = "network";
+        type = types.str;
+        description = ''
+          Members of this group can control <command>hostapd</command>.
+        '';
+      };
+
+      logLevel = mkOption {
+        default = 2;
+        type = types.int;
+        description = ''
+          Levels (minimum value for logged events):
+          0 = verbose debugging
+          1 = debugging
+          2 = informational messages
+          3 = notification
+          4 = warning
+        '';
+      };
+
+      driver = mkOption {
+        default = "nl80211";
+        example = "hostapd";
+        type = types.str;
+        description = ''
+          Which driver <command>hostapd</command> will use.
+          Most applications will probably use the default.
+        '';
+      };
+
+      channel = mkOption {
+        default = 7;
+        example = 11;
+        type = types.int;
+        description = ''
+          Channel number (IEEE 802.11)
+          Please note that some drivers do not use this value from
+          <command>hostapd</command> and the channel will need to be configured
+          separately with <command>iwconfig</command>.
+        '';
+      };
+
+      hwMode = mkOption {
+        default = "g";
+        type = types.enum [ "a" "b" "g" ];
+        description = ''
+          Operation mode.
+          (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE 802.11g).
+        '';
+      };
+
+      countryCode = mkOption {
+        default = null;
+        example = "US";
+        type = with types; nullOr str;
+        description = ''
+          Country code (ISO/IEC 3166-1). Used to set regulatory domain.
+          Set as needed to indicate country in which device is operating.
+          This can limit available channels and transmit power.
+          These two octets are used as the first two octets of the Country String
+          (dot11CountryString).
+          This enables IEEE 802.11d. This advertises the countryCode and the set
+          of allowed channels and transmit power levels based on the regulatory
+          limits.
+          This is required in most places by law and thus enforced to be set!
+        '';
+      };
+
+      ieee80211h = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Enable IEEE 802.11h. This enables radar detection and DFS support if
+          available. DFS support is required on outdoor 5 GHz channels in most countries
+          of the world.
+        '';
+      };
+
+      ieee80211n = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Whether IEEE 802.11n (HT) is enabled";
+      };
+
+      ht_capab = mkOption {
+        type = with types; listOf str;
+        default = ["HT40-" "SHORT-GI-20" "SHORT-GI-40"];
+        description = ''
+        HT capabilities (list of flags)
+        LDPC coding capability: [LDPC] = supported
+        Supported channel width set: [HT40-] = both 20 MHz and 40 MHz with secondary
+          channel below the primary channel; [HT40+] = both 20 MHz and 40 MHz
+          with secondary channel above the primary channel
+          (20 MHz only if neither is set)
+          Note: There are limits on which channels can be used with HT40- and
+          HT40+. Following table shows the channels that may be available for
+          HT40- and HT40+ use per IEEE 802.11n Annex J:
+          freq		HT40-		HT40+
+          2.4 GHz		5-13		1-7 (1-9 in Europe/Japan)
+          5 GHz		40,48,56,64	36,44,52,60
+          (depending on the location, not all of these channels may be available
+          for use)
+          Please note that 40 MHz channels may switch their primary and secondary
+          channels if needed or creation of 40 MHz channel maybe rejected based
+          on overlapping BSSes. These changes are done automatically when hostapd
+          is setting up the 40 MHz channel.
+        HT-greenfield: [GF] (disabled if not set)
+        Short GI for 20 MHz: [SHORT-GI-20] (disabled if not set)
+        Short GI for 40 MHz: [SHORT-GI-40] (disabled if not set)
+        Tx STBC: [TX-STBC] (disabled if not set)
+        Rx STBC: [RX-STBC1] (one spatial stream), [RX-STBC12] (one or two spatial
+          streams), or [RX-STBC123] (one, two, or three spatial streams); Rx STBC
+          disabled if none of these set
+        HT-delayed Block Ack: [DELAYED-BA] (disabled if not set)
+        Maximum A-MSDU length: [MAX-AMSDU-7935] for 7935 octets (3839 octets if not
+          set)
+        DSSS/CCK Mode in 40 MHz: [DSSS_CCK-40] = allowed (not allowed if not set)
+        40 MHz intolerant [40-INTOLERANT] (not advertised if not set)
+        L-SIG TXOP protection support: [LSIG-TXOP-PROT] (disabled if not set)
+        '';
+      };
+
+      require_ht = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Require stations to support VHT PHY (reject association if they do not)";
+      };
+
+      ieee80211ac = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether IEEE 802.11ac (VHT) is enabled";
+      };
+
+      vht_capab = mkOption {
+        type = with types; listOf str;
+        default = ["SHORT-GI-80" "HTC-VHT"];
+        description = ''
+          VHT capabilities (list of flags)
+
+          vht_max_mpdu_len: [MAX-MPDU-7991] [MAX-MPDU-11454]
+          Indicates maximum MPDU length
+          0 = 3895 octets (default)
+          1 = 7991 octets
+          2 = 11454 octets
+          3 = reserved
+
+          supported_chan_width: [VHT160] [VHT160-80PLUS80]
+          Indicates supported Channel widths
+          0 = 160 MHz & 80+80 channel widths are not supported (default)
+          1 = 160 MHz channel width is supported
+          2 = 160 MHz & 80+80 channel widths are supported
+          3 = reserved
+
+          Rx LDPC coding capability: [RXLDPC]
+          Indicates support for receiving LDPC coded pkts
+          0 = Not supported (default)
+          1 = Supported
+
+          Short GI for 80 MHz: [SHORT-GI-80]
+          Indicates short GI support for reception of packets transmitted with TXVECTOR
+          params format equal to VHT and CBW = 80Mhz
+          0 = Not supported (default)
+          1 = Supported
+
+          Short GI for 160 MHz: [SHORT-GI-160]
+          Indicates short GI support for reception of packets transmitted with TXVECTOR
+          params format equal to VHT and CBW = 160Mhz
+          0 = Not supported (default)
+          1 = Supported
+
+          Tx STBC: [TX-STBC-2BY1]
+          Indicates support for the transmission of at least 2x1 STBC
+          0 = Not supported (default)
+          1 = Supported
+
+          Rx STBC: [RX-STBC-1] [RX-STBC-12] [RX-STBC-123] [RX-STBC-1234]
+          Indicates support for the reception of PPDUs using STBC
+          0 = Not supported (default)
+          1 = support of one spatial stream
+          2 = support of one and two spatial streams
+          3 = support of one, two and three spatial streams
+          4 = support of one, two, three and four spatial streams
+          5,6,7 = reserved
+
+          SU Beamformer Capable: [SU-BEAMFORMER]
+          Indicates support for operation as a single user beamformer
+          0 = Not supported (default)
+          1 = Supported
+
+          SU Beamformee Capable: [SU-BEAMFORMEE]
+          Indicates support for operation as a single user beamformee
+          0 = Not supported (default)
+          1 = Supported
+
+          Compressed Steering Number of Beamformer Antennas Supported:
+          [BF-ANTENNA-2] [BF-ANTENNA-3] [BF-ANTENNA-4]
+            Beamformee's capability indicating the maximum number of beamformer
+            antennas the beamformee can support when sending compressed beamforming
+            feedback
+          If SU beamformer capable, set to maximum value minus 1
+          else reserved (default)
+
+          Number of Sounding Dimensions:
+          [SOUNDING-DIMENSION-2] [SOUNDING-DIMENSION-3] [SOUNDING-DIMENSION-4]
+          Beamformer's capability indicating the maximum value of the NUM_STS parameter
+          in the TXVECTOR of a VHT NDP
+          If SU beamformer capable, set to maximum value minus 1
+          else reserved (default)
+
+          MU Beamformer Capable: [MU-BEAMFORMER]
+          Indicates support for operation as an MU beamformer
+          0 = Not supported or sent by Non-AP STA (default)
+          1 = Supported
+
+          VHT TXOP PS: [VHT-TXOP-PS]
+          Indicates whether or not the AP supports VHT TXOP Power Save Mode
+           or whether or not the STA is in VHT TXOP Power Save mode
+          0 = VHT AP doesn't support VHT TXOP PS mode (OR) VHT STA not in VHT TXOP PS
+           mode
+          1 = VHT AP supports VHT TXOP PS mode (OR) VHT STA is in VHT TXOP power save
+           mode
+
+          +HTC-VHT Capable: [HTC-VHT]
+          Indicates whether or not the STA supports receiving a VHT variant HT Control
+          field.
+          0 = Not supported (default)
+          1 = supported
+
+          Maximum A-MPDU Length Exponent: [MAX-A-MPDU-LEN-EXP0]..[MAX-A-MPDU-LEN-EXP7]
+          Indicates the maximum length of A-MPDU pre-EOF padding that the STA can recv
+          This field is an integer in the range of 0 to 7.
+          The length defined by this field is equal to
+          2 pow(13 + Maximum A-MPDU Length Exponent) -1 octets
+
+          VHT Link Adaptation Capable: [VHT-LINK-ADAPT2] [VHT-LINK-ADAPT3]
+          Indicates whether or not the STA supports link adaptation using VHT variant
+          HT Control field
+          If +HTC-VHTcapable is 1
+           0 = (no feedback) if the STA does not provide VHT MFB (default)
+           1 = reserved
+           2 = (Unsolicited) if the STA provides only unsolicited VHT MFB
+           3 = (Both) if the STA can provide VHT MFB in response to VHT MRQ and if the
+               STA provides unsolicited VHT MFB
+          Reserved if +HTC-VHTcapable is 0
+
+          Rx Antenna Pattern Consistency: [RX-ANTENNA-PATTERN]
+          Indicates the possibility of Rx antenna pattern change
+          0 = Rx antenna pattern might change during the lifetime of an association
+          1 = Rx antenna pattern does not change during the lifetime of an association
+
+          Tx Antenna Pattern Consistency: [TX-ANTENNA-PATTERN]
+          Indicates the possibility of Tx antenna pattern change
+          0 = Tx antenna pattern might change during the lifetime of an association
+          1 = Tx antenna pattern does not change during the lifetime of an association
+        '';
+      };
+
+      require_vht = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Require stations to support VHT PHY (reject association if they do not)";
+      };
+
+      vht_oper_chwidth= mkOption {
+        type = types.int;
+        default = 1;
+        description = ''
+          0 = 20 or 40 MHz operating Channel width
+          1 = 80 MHz channel width
+          2 = 160 MHz channel width
+          3 = 80+80 MHz channel width
+          '';
+      };
+
+      vht_oper_centr_freq_seg0_idx = mkOption {
+        type = types.int;
+        default = 42;
+        description = ''
+          center freq 5 GHz + (5 * index)
+          So index 42 gives center freq 5.210 GHz which is channel 42 in 5G band.
+          '';
+      };
+
+      vht_oper_centr_freq_seg1_idx = mkOption {
+        type = types.int;
+        default = 159;
+        description = ''
+          center freq = 5 GHz + (5 * index)
+          So index 159 gives center freq 5.795 GHz which is channel 159 in 5G band.
+          '';
+      };
+
+      use_sta_nsts = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+        Workaround to use station's nsts capability in (Re)Association Response frame
+        This may be needed with some deployed devices as an interoperability
+        workaround for beamforming if the AP's capability is greater than the
+        station's capability. This is disabled by default and can be enabled by
+        setting use_sta_nsts=true.
+        '';
+      };
+
+      ieee80211ax = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether IEEE 802.11ax (HE) is enabled";
+      };
+
+      bss = mkOption {
+        type = with types; attrsOf (submodule {options = options_bss;});
+        default = { };
+        example = literalExpression ''
+          {
+            "wlan0host" = {
+              ssid = "HostNetwork";
+              wpaPassphrase = "NotSoSecretPassword";
+            };
+          }
+          '';
+        description = ''
+          Support for multiple BSSIDs.
+          '';
+      };
+
+      extraConfig = mkOption {
+        default = "";
+        type = types.lines;
+        description = "Extra configuration options to put in hostapd.conf.";
+      };
+
+  };
+
+
+  configFile = interface: let
+    icfg = cfg."${interface}";
+  in ''
+    ctrl_interface=/run/hostapd
+    ctrl_interface_group=${icfg.group}
+
+    # logging (debug level)
+    logger_syslog=-1
+    logger_syslog_level=${toString icfg.logLevel}
+    logger_stdout=-1
+    logger_stdout_level=${toString icfg.logLevel}
+
+    interface=${interface}
+    driver=${icfg.driver}
+    hw_mode=${icfg.hwMode}
+    channel=${toString icfg.channel}
+    country_code=${icfg.countryCode}
+    ieee80211d=1
+    ${optionalString (icfg.ieee80211h) "ieee80211h=1"}
+    ${optionalString icfg.ieee80211n ''
+      ieee80211n=1
+      ht_capab=${mapCapab icfg.ht_capab}
+      require_ht=${boolean icfg.require_ht}
+    ''}
+    ${optionalString icfg.ieee80211ac ''
+      ieee80211ac=1
+      vht_capab=${mapCapab icfg.vht_capab}
+      require_vht=${boolean icfg.require_vht}
+      vht_oper_chwidth=${toString icfg.vht_oper_chwidth}
+      vht_oper_centr_freq_seg0_idx=${toString icfg.vht_oper_centr_freq_seg0_idx}
+      vht_oper_centr_freq_seg1_idx=${toString icfg.vht_oper_centr_freq_seg1_idx}
+      use_sta_nsts=${boolean icfg.use_sta_nsts}
+    ''}
+    ${optionalString icfg.ieee80211ax ''
+      ieee80211ax=1
+    ''}
+
+    ssid=${icfg.ssid}
+    ${configBss icfg}
+
+    ${concatMapStringsSep "\n" (bss: ''
+      bss=${bss}
+      use_driver_iface_addr=1
+      ${configBss icfg.bss."${bss}"}'') (attrNames icfg.bss)}
+
+    ${icfg.extraConfig}
+  '';
+
+  mapCapab = list: concatStrings (map (key: "[${key}]") list);
+  boolean = bool: if bool then "1" else "0";
+
+  configBss = bsscfg: ''
+    ${optionalString bsscfg.wpa ''
+      wpa=2
+      wpa_pairwise=CCMP TKIP
+      wpa_key_mgmt=${if bsscfg.wpa3 then "SAE" else "WPA-PSK"}
+      ${optionalString (bsscfg.wpaPassphrase != null) "wpa_passphrase=${bsscfg.wpaPassphrase}"}
+      ${optionalString (bsscfg.wpaPskFile != null) "wpa_psk_file=${bsscfg.wpaPskFile}"}
+    ''}
+  '';
+
+  etcConfigs = listToAttrs (map
+    (n: nameValuePair "hostapd/${n}.conf" {text = configFile n;})
+    (attrNames (filterAttrs (n: v: v.enable) cfg))
+  );
+
+in
+
+{
+
+  #disabledModules = [ "services/networking/hostapd.nix" ];
+
+  ###### interface
+
+  options = {
+    networking.hostapd = mkOption {
+      type = with types; attrsOf (submodule {options = options_interface;});
+      default = { };
+      example = literalExpression ''
+        { "wlan0" = {
+            hw_mode = "a";
+            channel = 11;
+            ssid = "MyNetwork";
+            wpaPassphrase = "SecretPassword";
+          };
+        }
+        '';
+      description = ''
+        Interface for which to start <command>hostapd</command>.
+        '';
+    };
+  };
+
+
+  ###### implementation
+
+  config = mkIf (any (val: val.enable) (attrValues cfg)) {
+    assertions = [{
+      assertion = all (val: ! val.enable or val.countryCode != null) (attrValues cfg);
+      message = "Country code has to be specified to prevent violation of the law.";
+    }];
+    ## TODO mkRenamedOptionModule
+
+    environment.systemPackages = [ pkgs.hostapd ];
+    services.udev.packages = [ pkgs.crda ];
+
+    environment.etc = etcConfigs;
+
+    systemd.services.hostapd = let
+      interfaces = map utils.escapeSystemdPath (attrNames (filterAttrs (n: v: v.enable) cfg));
+      links = interfaces ++ (map utils.escapeSystemdPath (concatMap attrNames (catAttrs "bss" (attrValues (filterAttrs (n: v: v.enable) cfg)))));
+      devices = map (ifc: "sys-subsystem-net-devices-${ifc}.device") interfaces;
+      services = map (ifc: "network-link-${ifc}.service") links;
+    in {
+        description = "hostapd wireless AP";
+        path = [ pkgs.hostapd ];
+        after = devices;
+        bindsTo = devices;
+        requiredBy = services;
+        wantedBy = [ "multi-user.target" ];
+
+        serviceConfig =
+          { ExecStart = "${pkgs.hostapd}/bin/hostapd ${toString (map (v: "/etc/${v}") (attrNames etcConfigs))}";
+            Restart = "always";
+          };
+      };
+  };
+}