nixpkgs/nixos/modules/services/hardware/udev.nix
2024-08-30 00:30:53 +02:00

446 lines
15 KiB
Nix

{ config, lib, pkgs, ... }:
let
udev = config.systemd.package;
cfg = config.services.udev;
initrdUdevRules = pkgs.runCommand "initrd-udev-rules" {} ''
mkdir -p $out/etc/udev/rules.d
for f in 60-cdrom_id 60-persistent-storage 75-net-description 80-drivers 80-net-setup-link; do
ln -s ${config.boot.initrd.systemd.package}/lib/udev/rules.d/$f.rules $out/etc/udev/rules.d
done
'';
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 = ''
# Needed for gpm.
SUBSYSTEM=="input", KERNEL=="mice", TAG+="systemd"
'';
nixosInitrdRules = ''
# Mark dm devices as db_persist so that they are kept active after switching root
SUBSYSTEM=="block", KERNEL=="dm-[0-9]*", ACTION=="add|change", OPTIONS+="db_persist"
'';
# Perform substitutions in all udev rules files.
udevRulesFor = { name, udevPackages, udevPath, udev, systemd, binPackages, initrdBin ? null }: pkgs.runCommand name
{ preferLocalBuild = true;
allowSubstitutes = false;
packages = lib.unique (map toString udevPackages);
}
''
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 2>/dev/null
${lib.optionalString (initrdBin != null) ''
substituteInPlace $i --replace '/run/current-system/systemd' "${lib.removeSuffix "/bin" initrdBin}"
''}
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 [[ $i == /run/current-system/systemd* ]]; then
i="${systemd}/''${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
# list all files referring to (/usr)/bin paths, but allow references to /bin/sh.
grep -P -l '\B(?!\/bin\/sh\b)(\/usr)?\/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 ${toString binPackages}; do
for j in "$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.
${lib.optionalString (!config.boot.hardwareScan) ''
ln -s /dev/null $out/80-drivers.rules
''}
'';
hwdbBin = pkgs.runCommand "hwdb.bin"
{ preferLocalBuild = true;
allowSubstitutes = false;
packages = lib.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 $j)
done
done
echo "Generating hwdb database..."
# hwdb --update doesn't return error code even on errors!
res="$(${pkgs.buildPackages.systemd}/bin/systemd-hwdb --root=$(pwd) update 2>&1)"
echo "$res"
[ -z "$(echo "$res" | egrep '^Error')" ]
mv etc/udev/hwdb.bin $out
'';
compressFirmware = firmware:
let
inherit (config.boot.kernelPackages) kernelAtLeast;
in
if ! (firmware.compressFirmware or true) then
firmware
else
if kernelAtLeast "5.19" then pkgs.compressFirmwareZstd firmware
else if kernelAtLeast "5.3" then pkgs.compressFirmwareXz firmware
else firmware;
# 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 = lib.mkOption {
type = lib.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 = {
enable = lib.mkEnableOption "udev, a device manager for the Linux kernel" // {
default = true;
};
packages = lib.mkOption {
type = lib.types.listOf lib.types.path;
default = [];
description = ''
List of packages containing {command}`udev` rules.
All files found in
{file}`«pkg»/etc/udev/rules.d` and
{file}`«pkg»/lib/udev/rules.d`
will be included.
'';
apply = map lib.getBin;
};
path = lib.mkOption {
type = lib.types.listOf lib.types.path;
default = [];
description = ''
Packages added to the {env}`PATH` environment variable when
executing programs from Udev rules.
coreutils, gnu{sed,grep}, util-linux and config.systemd.package are
automatically included.
'';
};
extraRules = lib.mkOption {
default = "";
example = ''
ENV{ID_VENDOR_ID}=="046d", ENV{ID_MODEL_ID}=="0825", ENV{PULSE_IGNORE}="1"
'';
type = lib.types.lines;
description = ''
Additional {command}`udev` rules. They'll be written
into file {file}`99-local.rules`. Thus they are
read and applied after all other rules.
'';
};
extraHwdb = lib.mkOption {
default = "";
example = ''
evdev:input:b0003v05AFp8277*
KEYBOARD_KEY_70039=leftalt
KEYBOARD_KEY_700e2=leftctrl
'';
type = lib.types.lines;
description = ''
Additional {command}`hwdb` files. They'll be written
into file {file}`99-local.hwdb`. Thus they are
read after all other files.
'';
};
};
hardware.firmware = lib.mkOption {
type = lib.types.listOf lib.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 = map compressFirmware list;
pathsToLink = [ "/lib/firmware" ];
ignoreCollisions = true;
};
};
networking.usePredictableInterfaceNames = lib.mkOption {
default = true;
type = lib.types.bool;
description = ''
Whether to assign [predictable names to network interfaces](https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/).
If enabled, interfaces
are assigned names that contain topology information
(e.g. `wlp3s0`) 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
`eth0` and `eth1` flipping
unpredictably.
'';
};
boot.initrd.services.udev = {
packages = lib.mkOption {
type = lib.types.listOf lib.types.path;
default = [];
description = ''
*This will only be used when systemd is used in stage 1.*
List of packages containing {command}`udev` rules that will be copied to stage 1.
All files found in
{file}`«pkg»/etc/udev/rules.d` and
{file}`«pkg»/lib/udev/rules.d`
will be included.
'';
};
binPackages = lib.mkOption {
type = lib.types.listOf lib.types.path;
default = [];
description = ''
*This will only be used when systemd is used in stage 1.*
Packages to search for binaries that are referenced by the udev rules in stage 1.
This list always contains /bin of the initrd.
'';
apply = map lib.getBin;
};
rules = lib.mkOption {
default = "";
example = ''
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:1D:60:B9:6D:4F", KERNEL=="eth*", NAME="my_fast_network_card"
'';
type = lib.types.lines;
description = ''
{command}`udev` rules to include in the initrd
*only*. They'll be written into file
{file}`99-local.rules`. Thus they are read and applied
after the essential initrd rules.
'';
};
};
};
###### implementation
config = lib.mkIf cfg.enable {
services.udev.extraRules = nixosRules;
services.udev.packages = [ extraUdevRules extraHwdbFile ];
services.udev.path = [ pkgs.coreutils pkgs.gnused pkgs.gnugrep pkgs.util-linux udev ];
boot.kernelParams = lib.mkIf (!config.networking.usePredictableInterfaceNames) [ "net.ifnames=0" ];
boot.initrd.extraUdevRulesCommands = lib.mkIf (!config.boot.initrd.systemd.enable && config.boot.initrd.services.udev.rules != "")
''
cat <<'EOF' > $out/99-local.rules
${config.boot.initrd.services.udev.rules}
EOF
'';
boot.initrd.services.udev.rules = nixosInitrdRules;
boot.initrd.systemd.additionalUpstreamUnits = [
"initrd-udevadm-cleanup-db.service"
"systemd-udevd-control.socket"
"systemd-udevd-kernel.socket"
"systemd-udevd.service"
"systemd-udev-settle.service"
"systemd-udev-trigger.service"
];
boot.initrd.systemd.storePaths = [
"${config.boot.initrd.systemd.package}/lib/systemd/systemd-udevd"
"${config.boot.initrd.systemd.package}/lib/udev/ata_id"
"${config.boot.initrd.systemd.package}/lib/udev/cdrom_id"
"${config.boot.initrd.systemd.package}/lib/udev/scsi_id"
"${config.boot.initrd.systemd.package}/lib/udev/rules.d"
] ++ map (x: "${x}/bin") config.boot.initrd.services.udev.binPackages;
# Generate the udev rules for the initrd
boot.initrd.systemd.contents = {
"/etc/udev/rules.d".source = udevRulesFor {
name = "initrd-udev-rules";
initrdBin = config.boot.initrd.systemd.contents."/bin".source;
udevPackages = config.boot.initrd.services.udev.packages;
udevPath = config.boot.initrd.systemd.contents."/bin".source;
udev = config.boot.initrd.systemd.package;
systemd = config.boot.initrd.systemd.package;
binPackages = config.boot.initrd.services.udev.binPackages ++ [ config.boot.initrd.systemd.contents."/bin".source ];
};
};
# Insert initrd rules
boot.initrd.services.udev.packages = [
initrdUdevRules
(lib.mkIf (config.boot.initrd.services.udev.rules != "") (pkgs.writeTextFile {
name = "initrd-udev-rules";
destination = "/etc/udev/rules.d/99-local.rules";
text = config.boot.initrd.services.udev.rules;
}))
];
environment.etc = {
"udev/rules.d".source = udevRulesFor {
name = "udev-rules";
udevPackages = cfg.packages;
systemd = config.systemd.package;
binPackages = cfg.packages;
inherit udevPath udev;
};
"udev/hwdb.bin".source = hwdbBin;
} // lib.optionalAttrs config.boot.modprobeConfig.enable {
# We don't place this into `extraModprobeConfig` so that stage-1 ramdisk doesn't bloat.
"modprobe.d/firmware.conf".text = "options firmware_class path=${config.hardware.firmware}/lib/firmware";
};
system.requiredKernelConfig = with config.lib.kernelConfig; [
(isEnabled "UNIX")
(isYes "INOTIFY_USER")
(isYes "NET")
];
system.activationScripts.udevd = lib.mkIf config.boot.kernel.enable ''
# 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;
};
};
imports = [
(lib.mkRenamedOptionModule [ "services" "udev" "initrdRules" ] [ "boot" "initrd" "services" "udev" "rules" ])
];
}