nixpkgs/nixos/modules/services/hardware/udev.nix
Florian Klink 80b0997499 nixos/udev: harmonize extraRules example
Use the same sample as in https://wiki.debian.org/NetworkInterfaceNames,
which includes the `ACTION=="add"` condition.
2020-12-22 11:16:29 +01:00

320 lines
10 KiB
Nix

{ 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.
'';
};
extraRules = 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 = ''
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" ];
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")
];
boot.extraModprobeConfig = "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;
};
};
}