cat-dev 0.0.13

//! Server implementation for SATA Server.

mod change_mode;
mod change_owner;
mod close_file;
mod close_folder;
pub mod connection_flags;
mod create_folder;
mod info_by_query;
mod open_file;
mod open_folder;
mod ping;
mod read_file;
mod read_folder;
mod remove;
mod rename;
mod rewind_folder;
mod set_file_position;
pub mod wal;
mod write_file;

use crate::{
	errors::{APIError, CatBridgeError},
	fsemul::{
		HostFilesystem,
		pcfs::sata::{
			proto::SataRequest,
			server::{
				connection_flags::{
					SATA_CONNECTION_FLAGS, SataConnectionFlags, SataConnectionFlagsLayer,
				},
				wal::{
					WriteAheadLog,
					layer::{WALBeginStreamLayer, WALEndStreamLayer, WALMessageLayer},
				},
			},
		},
	},
	net::{
		DEFAULT_CAT_DEV_CHUNK_SIZE, DEFAULT_CAT_DEV_SLOWDOWN,
		additions::{RequestIDLayer, StreamIDLayer},
		models::{Endianness, FromRef, NagleGuard, Response},
		server::{Router, TCPServer, models::ResponseStreamEvent, requestable::Body},
	},
};
use bytes::Bytes;
use local_ip_address::local_ip;
use std::{
	net::{IpAddr, Ipv4Addr, SocketAddrV4},
	path::PathBuf,
	time::Duration,
};
use tower::ServiceBuilder;
use tracing::{field::valuable, warn};
use valuable::{Fields, NamedField, NamedValues, StructDef, Structable, Valuable, Value, Visit};

/// The default port to use for hosting the SATA Server.
pub const DEFAULT_SATA_PORT: u16 = 7500_u16;

/// The 'state' of the server that is server wide.
#[derive(Clone, Debug, Valuable)]
pub struct PcfsServerState {
	/// If we're not actually removing files, and preventing things from being removed.
	disable_real_removal: bool,
	/// The underlying host filesystem to write too.
	host_filesystem: HostFilesystem,
	/// Our process id.
	pid: u32,
}

impl PcfsServerState {
	#[must_use]
	pub const fn new(
		disable_real_removal: bool,
		host_filesystem: HostFilesystem,
		pid: u32,
	) -> Self {
		PcfsServerState {
			disable_real_removal,
			host_filesystem,
			pid,
		}
	}

	#[must_use]
	pub const fn disable_real_removal(&self) -> bool {
		self.disable_real_removal
	}

	#[must_use]
	pub const fn host_filesystem(&self) -> &HostFilesystem {
		&self.host_filesystem
	}

	#[must_use]
	pub const fn pid(&self) -> u32 {
		self.pid
	}
}

impl FromRef<PcfsServerState> for HostFilesystem {
	fn from_ref(input: &PcfsServerState) -> Self {
		input.host_filesystem.clone()
	}
}

impl FromRef<PcfsServerState> for u32 {
	fn from_ref(input: &PcfsServerState) -> Self {
		input.pid
	}
}

#[allow(
	// TODO(mythra): maybe refactor these into two variant enums.
	clippy::struct_excessive_bools,
)]
#[derive(Clone, Debug)]
pub struct PcfsSataServerBuilder {
	/// The explicit address to bind too, otherwise a local ip will be fetched.
	address: Option<Ipv4Addr>,
	/// Allow overriding the amount of time that we wait to make sure everything
	/// is safe for a cat-dev.
	///
	/// *note: `None` does not mean cat-dev sleep is disabled, that is controleld
	/// through [`Self::fully_disable_cat_dev_sleep`]*.
	cat_dev_sleep_override: Option<Duration>,
	/// Override the chunking value, and how many bytes we'll purposefully chunk on
	/// when sending out TCP data.
	///
	/// *note: `None` does not mean cat-dev sleep is disabled, that is controleld
	/// through [`Self::fully_disable_chunk_override`]*.
	chunk_override: Option<usize>,
	/// If we should disable Combined Send+Recv.
	disable_csr: bool,
	/// If we should disable FFIO.
	disable_ffio: bool,
	/// If we should disable real removal of files. Prevents anything from being lost.
	disable_real_removal: bool,
	/// An override to fully disable any cat-dev sleeping to prevent issues.
	fully_disable_cat_dev_sleep: bool,
	/// An override to fully disable any TCP level chunking.
	fully_disable_chunk_override: bool,
	/// The host filesystem to treat when serving PCFS-SATA requests.
	host_filesystem: HostFilesystem,
	/// The explicit port to bind too if not the default.
	port: Option<u16>,
	/// A place to write a SATA WAL too.
	sata_wal_location: Option<PathBuf>,
	/// If we should trace all I/O when in debug mode.
	trace_during_debug: bool,
}

impl PcfsSataServerBuilder {
	/// Create a new builder for creating a PCFS-Sata Server.
	#[must_use]
	pub const fn new(host_filesystem: HostFilesystem) -> Self {
		Self {
			address: None,
			cat_dev_sleep_override: None,
			chunk_override: None,
			disable_csr: false,
			disable_ffio: false,
			disable_real_removal: false,
			fully_disable_cat_dev_sleep: false,
			fully_disable_chunk_override: false,
			host_filesystem,
			port: None,
			sata_wal_location: None,
			trace_during_debug: false,
		}
	}

	#[must_use]
	pub const fn address(&self) -> Option<Ipv4Addr> {
		self.address
	}
	#[must_use]
	pub const fn set_address(mut self, new_address: Option<Ipv4Addr>) -> Self {
		self.address = new_address;
		self
	}

	#[must_use]
	pub const fn cat_dev_sleep_override(&self) -> Option<Duration> {
		self.cat_dev_sleep_override
	}
	#[must_use]
	pub const fn set_cat_dev_sleep_override(mut self, new: Option<Duration>) -> Self {
		self.cat_dev_sleep_override = new;
		self
	}

	#[must_use]
	pub const fn chunk_override(&self) -> Option<usize> {
		self.chunk_override
	}
	#[must_use]
	pub const fn set_chunk_override(mut self, chunk: Option<usize>) -> Self {
		self.chunk_override = chunk;
		self
	}

	#[must_use]
	pub const fn disable_csr(&self) -> bool {
		self.disable_csr
	}
	#[must_use]
	pub const fn set_disable_csr(mut self, new: bool) -> Self {
		self.disable_csr = new;
		self
	}

	#[must_use]
	pub const fn disable_ffio(&self) -> bool {
		self.disable_ffio
	}
	#[must_use]
	pub const fn set_disable_ffio(mut self, new: bool) -> Self {
		self.disable_ffio = new;
		self
	}

	#[must_use]
	pub const fn disable_real_removal(&self) -> bool {
		self.disable_real_removal
	}
	#[must_use]
	pub const fn set_disable_real_removal(mut self, new: bool) -> Self {
		self.disable_real_removal = new;
		self
	}

	#[must_use]
	pub const fn fully_disable_cat_dev_sleep(&self) -> bool {
		self.fully_disable_cat_dev_sleep
	}
	#[must_use]
	pub const fn set_fully_disable_cat_dev_sleep(mut self, new: bool) -> Self {
		self.fully_disable_cat_dev_sleep = new;
		self
	}

	#[must_use]
	pub const fn fully_disable_chunk_override(&self) -> bool {
		self.fully_disable_chunk_override
	}
	#[must_use]
	pub const fn set_fully_disable_chunk_override(mut self, new: bool) -> Self {
		self.fully_disable_chunk_override = new;
		self
	}

	#[must_use]
	pub const fn host_filesystem(&self) -> &HostFilesystem {
		&self.host_filesystem
	}
	#[must_use]
	pub fn set_host_filesystem(mut self, new: HostFilesystem) -> Self {
		self.host_filesystem = new;
		self
	}

	#[must_use]
	pub const fn port(&self) -> Option<u16> {
		self.port
	}
	#[must_use]
	pub const fn set_port(mut self, new: Option<u16>) -> Self {
		self.port = new;
		self
	}

	#[must_use]
	pub fn sata_wal_location(&self) -> Option<&PathBuf> {
		self.sata_wal_location.as_ref()
	}
	#[must_use]
	pub fn set_sata_wal_location(mut self, new_location: Option<PathBuf>) -> Self {
		self.sata_wal_location = new_location;
		self
	}

	#[must_use]
	pub const fn trace_during_debug(&self) -> bool {
		self.trace_during_debug
	}
	#[must_use]
	pub const fn set_trace_during_debug(mut self, new: bool) -> Self {
		self.trace_during_debug = new;
		self
	}

	/// Create a TCP server that is capable of serving PCFS-SATA to a cat-dev
	/// console.
	///
	/// ## Errors
	///
	/// If we cannot lookup the address to bind too, or there's been some
	/// programming error, and we run into an API error calling an internal
	/// api wrong.
	pub async fn build(self) -> Result<TCPServer<PcfsServerState>, CatBridgeError> {
		let ip = self
			.address
			.or_else(|| {
				// This always returns an ipv4 address, but is still returning
				// an ip address for legacy reasons.
				local_ip().ok().map(|ip| match ip {
					IpAddr::V4(v4) => v4,
					IpAddr::V6(_v6) => unreachable!(),
				})
			})
			.ok_or(APIError::NoHostIpFound)?;
		let bound_address = SocketAddrV4::new(ip, self.port.unwrap_or(DEFAULT_SATA_PORT));

		let mut router = Router::<PcfsServerState>::new_with_offset(0x30);
		router.add_route(&0x0_u32.to_be_bytes(), create_folder::handle_create_folder)?;
		router.add_route(&0x1_u32.to_be_bytes(), open_folder::handle_open_folder)?;
		router.add_route(&0x2_u32.to_be_bytes(), read_folder::handle_read_folder)?;
		router.add_route(&0x3_u32.to_be_bytes(), rewind_folder::handle_rewind_folder)?;
		router.add_route(&0x4_u32.to_be_bytes(), close_folder::handle_close_folder)?;
		router.add_route(&0x5_u32.to_be_bytes(), open_file::handle_open_file)?;
		router.add_route(&0x6_u32.to_be_bytes(), read_file::handle_read_file)?;
		router.add_route(&0x7_u32.to_be_bytes(), write_file::handle_write_file)?;
		router.add_route(
			&0x9_u32.to_be_bytes(),
			set_file_position::handle_set_file_position,
		)?;
		router.add_route(&0xB_u32.to_be_bytes(), info_by_query::stat_fd)?;
		router.add_route(&0xD_u32.to_be_bytes(), close_file::handle_close_file)?;
		router.add_route(&0xE_u32.to_be_bytes(), remove::handle_removal)?;
		router.add_route(&0xF_u32.to_be_bytes(), rename::handle_rename)?;
		router.add_route(
			&0x10_u32.to_be_bytes(),
			info_by_query::handle_get_info_by_query,
		)?;
		router.add_route(&0x12_u32.to_be_bytes(), change_owner::handle_change_owner)?;
		router.add_route(&0x13_u32.to_be_bytes(), change_mode::handle_change_mode)?;
		router.add_route(&0x14_u32.to_be_bytes(), ping::handle_ping)?;
		router.fallback_handler(unknown_packet_handler)?;

		let mut server = TCPServer::new_with_state(
			"pcfs-sata",
			bound_address,
			router,
			(None, None),
			NagleGuard::U32LengthPrefixed(Endianness::Big, Some(0x20)),
			PcfsServerState::new(
				self.disable_real_removal,
				self.host_filesystem,
				std::process::id(),
			),
			self.trace_during_debug,
		)
		.await?;
		let wal = self
			.sata_wal_location
			.and_then(|path| WriteAheadLog::new(path).ok());

		server.set_on_stream_begin(async move |event: ResponseStreamEvent<PcfsServerState>| {
			let sid = event.stream_id();

			_ = SATA_CONNECTION_FLAGS
				.insert_async(
					sid,
					SataConnectionFlags::new_with_flags(!self.disable_ffio, !self.disable_csr),
				)
				.await;

			Ok(true)
		})?;
		if let Some(w) = wal.as_ref() {
			server.layer_on_stream_begin(WALBeginStreamLayer(w.clone()))?;
		}
		server.set_on_stream_end(on_sata_stream_end)?;
		if let Some(w) = wal.as_ref() {
			server.layer_on_stream_end(WALEndStreamLayer(w.clone()))?;
		}

		create_initial_server_layer(&mut server, wal, self.trace_during_debug);

		server.set_chunk_output_at_size(if self.fully_disable_chunk_override {
			None
		} else if let Some(over_ride) = self.chunk_override {
			Some(over_ride)
		} else {
			Some(DEFAULT_CAT_DEV_CHUNK_SIZE)
		});
		server.set_cat_dev_slowdown(if self.fully_disable_cat_dev_sleep {
			None
		} else if let Some(over_ride) = self.cat_dev_sleep_override {
			Some(over_ride)
		} else {
			Some(DEFAULT_CAT_DEV_SLOWDOWN)
		});

		Ok(server)
	}
}

const PCFS_SATA_SERVER_BUILDER_FIELDS: &[NamedField<'static>] = &[
	NamedField::new("address"),
	NamedField::new("cat_dev_sleep_override"),
	NamedField::new("chunk_override"),
	NamedField::new("disable_csr"),
	NamedField::new("disable_ffio"),
	NamedField::new("disable_real_removal"),
	NamedField::new("fully_disable_cat_dev_sleep"),
	NamedField::new("fully_disable_chunk_override"),
	NamedField::new("host_filesystem"),
	NamedField::new("port"),
	NamedField::new("sata_wal_location"),
	NamedField::new("trace_during_debug"),
];

impl Structable for PcfsSataServerBuilder {
	fn definition(&self) -> StructDef<'_> {
		StructDef::new_static(
			"PcfsSataServerBuilder",
			Fields::Named(PCFS_SATA_SERVER_BUILDER_FIELDS),
		)
	}
}

impl Valuable for PcfsSataServerBuilder {
	fn as_value(&self) -> Value<'_> {
		Value::Structable(self)
	}

	fn visit(&self, visitor: &mut dyn Visit) {
		visitor.visit_named_fields(&NamedValues::new(
			PCFS_SATA_SERVER_BUILDER_FIELDS,
			&[
				Valuable::as_value(
					&self
						.address
						.map_or_else(|| "<none>".to_owned(), |ip| format!("{ip}")),
				),
				Valuable::as_value(
					&self
						.cat_dev_sleep_override
						.map_or_else(|| "<none>".to_owned(), |dur| format!("{}s", dur.as_secs())),
				),
				Valuable::as_value(&self.chunk_override),
				Valuable::as_value(&self.disable_csr),
				Valuable::as_value(&self.disable_ffio),
				Valuable::as_value(&self.disable_real_removal),
				Valuable::as_value(&self.fully_disable_cat_dev_sleep),
				Valuable::as_value(&self.fully_disable_chunk_override),
				Valuable::as_value(&self.host_filesystem),
				Valuable::as_value(&self.port),
				Valuable::as_value(&self.sata_wal_location),
				Valuable::as_value(&self.trace_during_debug),
			],
		));
	}
}

fn create_initial_server_layer(
	server: &mut TCPServer<PcfsServerState>,
	mut wal: Option<WriteAheadLog>,
	trace_during_debug: bool,
) {
	if let Some(w) = wal.take() {
		if trace_during_debug {
			server.layer_initial_service(
				ServiceBuilder::new()
					.layer(RequestIDLayer::new("sata".to_owned()))
					.layer(StreamIDLayer)
					.layer(SataConnectionFlagsLayer)
					.layer(WALMessageLayer(w)),
			);
		} else {
			server.layer_initial_service(
				ServiceBuilder::new()
					.layer(RequestIDLayer::new("sata".to_owned()))
					.layer(SataConnectionFlagsLayer)
					.layer(WALMessageLayer(w)),
			);
		}
	} else if trace_during_debug {
		server.layer_initial_service(
			ServiceBuilder::new()
				.layer(RequestIDLayer::new("sata".to_owned()))
				.layer(StreamIDLayer)
				.layer(SataConnectionFlagsLayer),
		);
	} else {
		server.layer_initial_service(
			ServiceBuilder::new()
				.layer(RequestIDLayer::new("sata".to_owned()))
				.layer(SataConnectionFlagsLayer),
		);
	}
}

async fn unknown_packet_handler(Body(request): Body<Bytes>) -> Response {
	if let Ok(req) = SataRequest::<Bytes>::parse_opaque(request.clone()) {
		warn!(
			header = valuable(req.header()),
			command_info = valuable(req.command_info()),
			body = format!("{:02X?}", req.body()),
			"Unknown Pcfs Sata packet!",
		);
	} else {
		warn!(
			packet = format!("{:02X?}", request),
			"Unknown Unparsable Pcfs Sata Packet!",
		);
	}

	Response::empty_close()
}

/// Gets called when an PCFS SATA stream ends.
///
/// This is where we actually 'cleanup' all the data related to the PCFS
/// stream. For us this really just means clearing the stream id from the map
/// of version/capability flags we're using.
///
/// ## Errors
///
/// This shouldn't ever error, but needs to make the signature pass to auto
/// turn into a tower service.
async fn on_sata_stream_end(
	event: ResponseStreamEvent<PcfsServerState>,
) -> Result<(), CatBridgeError> {
	let sid = event.stream_id();
	_ = SATA_CONNECTION_FLAGS.remove_async(&sid).await;
	Ok(())
}