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Active-session device access manager
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5.6 kB · 184 lines
Rust
at master
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pub struct Config { pub lua: mlua::Lua, pub rules: rc::Rc<cell::RefCell<Vec<LuaRule>>>,}
impl Config { pub fn load(rule_dirs: &[path::PathBuf]) -> anyhow::Result<Self> { let lua = mlua::Lua::new_with( mlua::StdLib::TABLE | mlua::StdLib::STRING | mlua::StdLib::MATH | mlua::StdLib::UTF8, mlua::LuaOptions::default(), ) .map_err(|e| anyhow::anyhow!("{e}"))?; lua.set_memory_limit(512 * 1024) .map_err(|e| anyhow::anyhow!("{e}"))?;
let globals = lua.globals(); globals .set("api_version", 1) .map_err(|e| anyhow::anyhow!("{e}"))?;
let rules = rc::Rc::new(cell::RefCell::new(Vec::new()));
let device_fn = lua .create_function({ let rules = rc::Rc::clone(&rules); move |lua, rule: mlua::Table| { let access = match rule.get::<String>("access")?.as_str() { "r" => AccessMode::Read, "w" => AccessMode::Write, "rw" => AccessMode::ReadWrite, other => { return Err(mlua::Error::RuntimeError(format!( "invalid access mode: {other}" ))); } };
let match_fn = lua.create_registry_value(rule.get::<mlua::Function>("match")?)?;
rules.borrow_mut().push(LuaRule { access, match_fn });
Ok(()) } }) .map_err(|e| anyhow::anyhow!("{e}"))?;
lua.globals() .set("device", device_fn) .map_err(|e| anyhow::anyhow!("{e}"))?;
for dir in rule_dirs.iter().filter(|dir| dir.exists()) { let mut rule_paths = fs::read_dir(dir)? .map(|rule| rule.map(|rule| rule.path())) .collect::<Result<Vec<_>, _>>()?; rule_paths.retain(|path| path.extension().is_some_and(|extension| extension == "lua")); rule_paths.sort();
for path in rule_paths { let source = fs::read_to_string(&path)?;
lua.load(&source) .set_name(path.to_string_lossy().as_ref()) .exec() .map_err(|e| anyhow::anyhow!("{e}"))?;
log::debug!(path:% = path.display(); "loaded Lua rule file"); } }
Ok(Self { lua, rules }) }}
#[derive(Clone, Copy, PartialEq, Eq)]pub enum AccessMode { Read, Write, ReadWrite,}
impl AccessMode { pub const fn as_str(self) -> &'static str { match self { Self::Read => "r", Self::Write => "w", Self::ReadWrite => "rw", } }}
pub struct LuaRule { pub access: AccessMode, pub match_fn: mlua::RegistryKey,}
#[derive(Clone)]pub struct LuaDevice { pub device: udev::Device,}
impl LuaDevice { pub const fn new(device: udev::Device) -> Self { Self { device } }}
impl mlua::UserData for LuaDevice { fn add_fields<F: mlua::UserDataFields<Self>>(fields: &mut F) { fields.add_field_method_get("subsystem", |_, this| { Ok(this .device .subsystem() .map(|subsystem| subsystem.to_string_lossy().into_owned())) });
fields.add_field_method_get("sysname", |_, this| { Ok(this.device.sysname().to_string_lossy().into_owned()) });
fields.add_field_method_get("syspath", |_, this| { Ok(this.device.syspath().to_string_lossy().into_owned()) });
fields.add_field_method_get("devnode", |_, this| { Ok(this .device .devnode() .map(|devnode| devnode.to_string_lossy().into_owned())) }); }
fn add_methods<M: mlua::UserDataMethods<Self>>(methods: &mut M) { methods.add_method("attr", |_, this, name: String| { Ok(this .device .attribute_value(&name) .map(|value| value.to_string_lossy().into_owned())) });
methods.add_method("property", |_, this, name: String| { Ok(this .device .property_value(&name) .map(|value| value.to_string_lossy().into_owned())) });
methods.add_method("parent", |lua, this, subsystem: Option<String>| { let mut parent = this.device.parent();
while let Some(device) = parent { let matches = subsystem.as_deref().is_none_or(|subsystem| { device .subsystem() .is_some_and(|device_subsystem| device_subsystem == subsystem) });
if matches { return lua.create_userdata(Self::new(device)).map(Some); }
parent = device.parent(); }
Ok(None::<mlua::AnyUserData>) });
methods.add_method("parents", |lua, this, ()| { let parents = lua.create_table()?; let mut parent = this.device.parent(); let mut index = 1;
while let Some(device) = parent { parents.set(index, Self::new(device.clone()))?; index += 1; parent = device.parent(); }
Ok(parents) }); }}