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-rw-r--r--nixos/modules/services/hardware/udev.nix341
1 files changed, 341 insertions, 0 deletions
diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
new file mode 100644
index 00000000000..61448af2d33
--- /dev/null
+++ b/nixos/modules/services/hardware/udev.nix
@@ -0,0 +1,341 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  udev = config.systemd.package;
+
+  cfg = config.services.udev;
+
+  extraUdevRules = pkgs.writeTextFile {
+    name = "extra-udev-rules";
+    text = cfg.extraRules;
+    destination = "/etc/udev/rules.d/99-local.rules";
+  };
+
+  extraHwdbFile = pkgs.writeTextFile {
+    name = "extra-hwdb-file";
+    text = cfg.extraHwdb;
+    destination = "/etc/udev/hwdb.d/99-local.hwdb";
+  };
+
+  nixosRules = ''
+    # Miscellaneous devices.
+    KERNEL=="kvm",                  MODE="0666"
+    KERNEL=="kqemu",                MODE="0666"
+
+    # Needed for gpm.
+    SUBSYSTEM=="input", KERNEL=="mice", TAG+="systemd"
+  '';
+
+  # Perform substitutions in all udev rules files.
+  udevRules = pkgs.runCommand "udev-rules"
+    { preferLocalBuild = true;
+      allowSubstitutes = false;
+      packages = unique (map toString cfg.packages);
+    }
+    ''
+      mkdir -p $out
+      shopt -s nullglob
+      set +o pipefail
+
+      # Set a reasonable $PATH for programs called by udev rules.
+      echo 'ENV{PATH}="${udevPath}/bin:${udevPath}/sbin"' > $out/00-path.rules
+
+      # Add the udev rules from other packages.
+      for i in $packages; do
+        echo "Adding rules for package $i"
+        for j in $i/{etc,lib}/udev/rules.d/*; do
+          echo "Copying $j to $out/$(basename $j)"
+          cat $j > $out/$(basename $j)
+        done
+      done
+
+      # Fix some paths in the standard udev rules.  Hacky.
+      for i in $out/*.rules; do
+        substituteInPlace $i \
+          --replace \"/sbin/modprobe \"${pkgs.kmod}/bin/modprobe \
+          --replace \"/sbin/mdadm \"${pkgs.mdadm}/sbin/mdadm \
+          --replace \"/sbin/blkid \"${pkgs.util-linux}/sbin/blkid \
+          --replace \"/bin/mount \"${pkgs.util-linux}/bin/mount \
+          --replace /usr/bin/readlink ${pkgs.coreutils}/bin/readlink \
+          --replace /usr/bin/basename ${pkgs.coreutils}/bin/basename
+      done
+
+      echo -n "Checking that all programs called by relative paths in udev rules exist in ${udev}/lib/udev... "
+      import_progs=$(grep 'IMPORT{program}="[^/$]' $out/* |
+        sed -e 's/.*IMPORT{program}="\([^ "]*\)[ "].*/\1/' | uniq)
+      run_progs=$(grep -v '^[[:space:]]*#' $out/* | grep 'RUN+="[^/$]' |
+        sed -e 's/.*RUN+="\([^ "]*\)[ "].*/\1/' | uniq)
+      for i in $import_progs $run_progs; do
+        if [[ ! -x ${udev}/lib/udev/$i && ! $i =~ socket:.* ]]; then
+          echo "FAIL"
+          echo "$i is called in udev rules but not installed by udev"
+          exit 1
+        fi
+      done
+      echo "OK"
+
+      echo -n "Checking that all programs called by absolute paths in udev rules exist... "
+      import_progs=$(grep 'IMPORT{program}="\/' $out/* |
+        sed -e 's/.*IMPORT{program}="\([^ "]*\)[ "].*/\1/' | uniq)
+      run_progs=$(grep -v '^[[:space:]]*#' $out/* | grep 'RUN+="/' |
+        sed -e 's/.*RUN+="\([^ "]*\)[ "].*/\1/' | uniq)
+      for i in $import_progs $run_progs; do
+        # if the path refers to /run/current-system/systemd, replace with config.systemd.package
+        if [[ $i == /run/current-system/systemd* ]]; then
+          i="${config.systemd.package}/''${i#/run/current-system/systemd/}"
+        fi
+        if [[ ! -x $i ]]; then
+          echo "FAIL"
+          echo "$i is called in udev rules but is not executable or does not exist"
+          exit 1
+        fi
+      done
+      echo "OK"
+
+      filesToFixup="$(for i in "$out"/*; do
+        grep -l '\B\(/usr\)\?/s\?bin' "$i" || :
+      done)"
+
+      if [ -n "$filesToFixup" ]; then
+        echo "Consider fixing the following udev rules:"
+        echo "$filesToFixup" | while read localFile; do
+          remoteFile="origin unknown"
+          for i in ${toString cfg.packages}; do
+            for j in "$i"/*/udev/rules.d/*; do
+              [ -e "$out/$(basename "$j")" ] || continue
+              [ "$(basename "$j")" = "$(basename "$localFile")" ] || continue
+              remoteFile="originally from $j"
+              break 2
+            done
+          done
+          refs="$(
+            grep -o '\B\(/usr\)\?/s\?bin/[^ "]\+' "$localFile" \
+              | sed -e ':r;N;''${s/\n/ and /;br};s/\n/, /g;br'
+          )"
+          echo "$localFile ($remoteFile) contains references to $refs."
+        done
+        exit 1
+      fi
+
+      # If auto-configuration is disabled, then remove
+      # udev's 80-drivers.rules file, which contains rules for
+      # automatically calling modprobe.
+      ${optionalString (!config.boot.hardwareScan) ''
+        ln -s /dev/null $out/80-drivers.rules
+      ''}
+    ''; # */
+
+  hwdbBin = pkgs.runCommand "hwdb.bin"
+    { preferLocalBuild = true;
+      allowSubstitutes = false;
+      packages = unique (map toString ([udev] ++ cfg.packages));
+    }
+    ''
+      mkdir -p etc/udev/hwdb.d
+      for i in $packages; do
+        echo "Adding hwdb files for package $i"
+        for j in $i/{etc,lib}/udev/hwdb.d/*; do
+          ln -s $j etc/udev/hwdb.d/$(basename $j)
+        done
+      done
+
+      echo "Generating hwdb database..."
+      # hwdb --update doesn't return error code even on errors!
+      res="$(${pkgs.buildPackages.udev}/bin/udevadm hwdb --update --root=$(pwd) 2>&1)"
+      echo "$res"
+      [ -z "$(echo "$res" | egrep '^Error')" ]
+      mv etc/udev/hwdb.bin $out
+    '';
+
+  # Udev has a 512-character limit for ENV{PATH}, so create a symlink
+  # tree to work around this.
+  udevPath = pkgs.buildEnv {
+    name = "udev-path";
+    paths = cfg.path;
+    pathsToLink = [ "/bin" "/sbin" ];
+    ignoreCollisions = true;
+  };
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    boot.hardwareScan = mkOption {
+      type = types.bool;
+      default = true;
+      description = ''
+        Whether to try to load kernel modules for all detected hardware.
+        Usually this does a good job of providing you with the modules
+        you need, but sometimes it can crash the system or cause other
+        nasty effects.
+      '';
+    };
+
+    services.udev = {
+
+      packages = mkOption {
+        type = types.listOf types.path;
+        default = [];
+        description = ''
+          List of packages containing <command>udev</command> rules.
+          All files found in
+          <filename><replaceable>pkg</replaceable>/etc/udev/rules.d</filename> and
+          <filename><replaceable>pkg</replaceable>/lib/udev/rules.d</filename>
+          will be included.
+        '';
+        apply = map getBin;
+      };
+
+      path = mkOption {
+        type = types.listOf types.path;
+        default = [];
+        description = ''
+          Packages added to the <envar>PATH</envar> environment variable when
+          executing programs from Udev rules.
+        '';
+      };
+
+      initrdRules = mkOption {
+        default = "";
+        example = ''
+          SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:1D:60:B9:6D:4F", KERNEL=="eth*", NAME="my_fast_network_card"
+        '';
+        type = types.lines;
+        description = ''
+          <command>udev</command> rules to include in the initrd
+          <emphasis>only</emphasis>. They'll be written into file
+          <filename>99-local.rules</filename>. Thus they are read and applied
+          after the essential initrd rules.
+        '';
+      };
+
+      extraRules = mkOption {
+        default = "";
+        example = ''
+          ENV{ID_VENDOR_ID}=="046d", ENV{ID_MODEL_ID}=="0825", ENV{PULSE_IGNORE}="1"
+        '';
+        type = types.lines;
+        description = ''
+          Additional <command>udev</command> rules. They'll be written
+          into file <filename>99-local.rules</filename>. Thus they are
+          read and applied after all other rules.
+        '';
+      };
+
+      extraHwdb = mkOption {
+        default = "";
+        example = ''
+          evdev:input:b0003v05AFp8277*
+            KEYBOARD_KEY_70039=leftalt
+            KEYBOARD_KEY_700e2=leftctrl
+        '';
+        type = types.lines;
+        description = ''
+          Additional <command>hwdb</command> files. They'll be written
+          into file <filename>99-local.hwdb</filename>. Thus they are
+          read after all other files.
+        '';
+      };
+
+    };
+
+    hardware.firmware = mkOption {
+      type = types.listOf types.package;
+      default = [];
+      description = ''
+        List of packages containing firmware files.  Such files
+        will be loaded automatically if the kernel asks for them
+        (i.e., when it has detected specific hardware that requires
+        firmware to function).  If multiple packages contain firmware
+        files with the same name, the first package in the list takes
+        precedence.  Note that you must rebuild your system if you add
+        files to any of these directories.
+      '';
+      apply = list: pkgs.buildEnv {
+        name = "firmware";
+        paths = list;
+        pathsToLink = [ "/lib/firmware" ];
+        ignoreCollisions = true;
+      };
+    };
+
+    networking.usePredictableInterfaceNames = mkOption {
+      default = true;
+      type = types.bool;
+      description = ''
+        Whether to assign <link
+        xlink:href='http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames'>predictable
+        names to network interfaces</link>.  If enabled, interfaces
+        are assigned names that contain topology information
+        (e.g. <literal>wlp3s0</literal>) and thus should be stable
+        across reboots.  If disabled, names depend on the order in
+        which interfaces are discovered by the kernel, which may
+        change randomly across reboots; for instance, you may find
+        <literal>eth0</literal> and <literal>eth1</literal> flipping
+        unpredictably.
+      '';
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf (!config.boot.isContainer) {
+
+    services.udev.extraRules = nixosRules;
+
+    services.udev.packages = [ extraUdevRules extraHwdbFile ];
+
+    services.udev.path = [ pkgs.coreutils pkgs.gnused pkgs.gnugrep pkgs.util-linux udev ];
+
+    boot.kernelParams = mkIf (!config.networking.usePredictableInterfaceNames) [ "net.ifnames=0" ];
+
+    boot.initrd.extraUdevRulesCommands = optionalString (cfg.initrdRules != "")
+      ''
+        cat <<'EOF' > $out/99-local.rules
+        ${cfg.initrdRules}
+        EOF
+      '';
+
+    environment.etc =
+      {
+        "udev/rules.d".source = udevRules;
+        "udev/hwdb.bin".source = hwdbBin;
+      };
+
+    system.requiredKernelConfig = with config.lib.kernelConfig; [
+      (isEnabled "UNIX")
+      (isYes "INOTIFY_USER")
+      (isYes "NET")
+    ];
+
+    # We don't place this into `extraModprobeConfig` so that stage-1 ramdisk doesn't bloat.
+    environment.etc."modprobe.d/firmware.conf".text = "options firmware_class path=${config.hardware.firmware}/lib/firmware";
+
+    system.activationScripts.udevd =
+      ''
+        # The deprecated hotplug uevent helper is not used anymore
+        if [ -e /proc/sys/kernel/hotplug ]; then
+          echo "" > /proc/sys/kernel/hotplug
+        fi
+
+        # Allow the kernel to find our firmware.
+        if [ -e /sys/module/firmware_class/parameters/path ]; then
+          echo -n "${config.hardware.firmware}/lib/firmware" > /sys/module/firmware_class/parameters/path
+        fi
+      '';
+
+    systemd.services.systemd-udevd =
+      { restartTriggers = cfg.packages;
+      };
+
+  };
+}