lib.rs

mod bitcoin;
pub mod commands;
pub mod config;
#[cfg(unix)]
mod daemonize;
mod database;
pub mod descriptors;
#[cfg(feature = "jsonrpc_server")]
mod jsonrpc;
#[cfg(test)]
mod testutils;

pub use miniscript;

#[cfg(feature = "jsonrpc_server")]
use crate::jsonrpc::server::{rpcserver_loop, rpcserver_setup};
use crate::{
    bitcoin::{
        d::{BitcoinD, BitcoindError},
        poller, BitcoinInterface,
    },
    config::Config,
    database::{
        sqlite::{FreshDbOptions, SqliteDb, SqliteDbError},
        DatabaseInterface,
    },
};

use std::{error, fmt, fs, io, path, sync};

use miniscript::bitcoin::secp256k1;

#[cfg(not(test))]
use std::{panic, process};
// A panic in any thread should stop the main thread, and print the panic.
#[cfg(not(test))]
fn setup_panic_hook() {
    panic::set_hook(Box::new(move |panic_info| {
        let file = panic_info
            .location()
            .map(|l| l.file())
            .unwrap_or_else(|| "'unknown'");
        let line = panic_info
            .location()
            .map(|l| l.line().to_string())
            .unwrap_or_else(|| "'unknown'".to_string());

        let bt = backtrace::Backtrace::new();
        let info = panic_info
            .payload()
            .downcast_ref::<&str>()
            .map(|s| s.to_string())
            .or_else(|| panic_info.payload().downcast_ref::<String>().cloned());
        log::error!(
            "panic occurred at line {} of file {}: {:?}\n{:?}",
            line,
            file,
            info,
            bt
        );

        process::exit(1);
    }));
}

#[derive(Debug, Clone)]
pub struct Version {
    pub major: u32,
    pub minor: u32,
}

impl fmt::Display for Version {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}.{}", self.major, self.minor)
    }
}

pub const VERSION: Version = Version { major: 0, minor: 1 };

#[derive(Debug)]
pub enum StartupError {
    Io(io::Error),
    DefaultDataDirNotFound,
    DatadirCreation(path::PathBuf, io::Error),
    MissingBitcoindConfig,
    Database(SqliteDbError),
    Bitcoind(BitcoindError),
    #[cfg(unix)]
    Daemonization(&'static str),
}

impl fmt::Display for StartupError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Io(e) => write!(f, "{}", e),
            Self::DefaultDataDirNotFound => write!(
                f,
                "Not data directory was specified and a default path could not be determined for this platform."
            ),
            Self::DatadirCreation(dir_path, e) => write!(
                f,
                "Could not create data directory at '{}': '{}'", dir_path.display(), e
            ),
            Self::MissingBitcoindConfig => write!(
                f,
                "Our Bitcoin interface is bitcoind but we have no 'bitcoind_config' entry in the configuration."
            ),
            Self::Database(e) => write!(f, "Error initializing database: '{}'.", e),
            Self::Bitcoind(e) => write!(f, "Error setting up bitcoind interface: '{}'.", e),
            #[cfg(unix)]
            Self::Daemonization(e) => write!(f, "Error when daemonizing: '{}'.", e),
        }
    }
}

impl error::Error for StartupError {}

impl From<io::Error> for StartupError {
    fn from(e: io::Error) -> Self {
        Self::Io(e)
    }
}

impl From<SqliteDbError> for StartupError {
    fn from(e: SqliteDbError) -> Self {
        Self::Database(e)
    }
}

impl From<BitcoindError> for StartupError {
    fn from(e: BitcoindError) -> Self {
        Self::Bitcoind(e)
    }
}

fn create_datadir(datadir_path: &path::Path) -> Result<(), StartupError> {
    #[cfg(unix)]
    return {
        use fs::DirBuilder;
        use std::os::unix::fs::DirBuilderExt;

        let mut builder = DirBuilder::new();
        builder
            .mode(0o700)
            .recursive(true)
            .create(datadir_path)
            .map_err(|e| StartupError::DatadirCreation(datadir_path.to_path_buf(), e))
    };

    // TODO: permissions on Windows..
    #[cfg(not(unix))]
    return {
        fs::create_dir_all(datadir_path)
            .map_err(|e| StartupError::DatadirCreation(datadir_path.to_path_buf(), e))
    };
}

// Connect to the SQLite database. Create it if starting fresh, and do some sanity checks.
// If all went well, returns the interface to the SQLite database.
fn setup_sqlite(
    config: &Config,
    data_dir: &path::Path,
    fresh_data_dir: bool,
    secp: &secp256k1::Secp256k1<secp256k1::VerifyOnly>,
) -> Result<SqliteDb, StartupError> {
    let db_path: path::PathBuf = [data_dir, path::Path::new("lianad.sqlite3")]
        .iter()
        .collect();
    let options = if fresh_data_dir {
        Some(FreshDbOptions {
            bitcoind_network: config.bitcoin_config.network,
            main_descriptor: config.main_descriptor.clone(),
        })
    } else {
        None
    };
    let sqlite = SqliteDb::new(db_path, options, secp)?;
    sqlite.sanity_check(config.bitcoin_config.network, &config.main_descriptor)?;
    log::info!("Database initialized and checked.");

    Ok(sqlite)
}

// Connect to bitcoind. Setup the watchonly wallet, and do some sanity checks.
// If all went well, returns the interface to bitcoind.
fn setup_bitcoind(
    config: &Config,
    data_dir: &path::Path,
    fresh_data_dir: bool,
) -> Result<BitcoinD, StartupError> {
    // NOTE: this is a hack! We normally store the watchonly wallet within our data directory.
    // But on windows bitcoind would prefix the wallet path with "C:\\\\?" when calling
    // 'loadwallet'. Therefore instead on Windows store the wallet.dat in bitcoind's data directory
    // instead by not providing an absolute path but the name of a wallet.
    #[cfg(not(windows))]
    let wo_path: path::PathBuf = [data_dir, path::Path::new("lianad_watchonly_wallet")]
        .iter()
        .collect();
    #[cfg(windows)]
    let wo_path = path::Path::new("lianad_watchonly_wallet");

    let bitcoind = BitcoinD::new(
        config
            .bitcoind_config
            .as_ref()
            .ok_or(StartupError::MissingBitcoindConfig)?,
        wo_path.to_str().expect("Must be valid unicode").to_string(),
    )?;
    if fresh_data_dir {
        bitcoind.create_watchonly_wallet(&config.main_descriptor)?;
        log::info!("Created a new watchonly wallet on bitcoind.");
    }
    bitcoind.maybe_load_watchonly_wallet()?;
    bitcoind.sanity_check(&config.main_descriptor, config.bitcoin_config.network)?;
    log::info!("Connection to bitcoind established and checked.");

    Ok(bitcoind)
}

#[derive(Clone)]
pub struct DaemonControl {
    config: Config,
    bitcoin: sync::Arc<sync::Mutex<dyn BitcoinInterface>>,
    // FIXME: Should we require Sync on DatabaseInterface rather than using a Mutex?
    db: sync::Arc<sync::Mutex<dyn DatabaseInterface>>,
    secp: secp256k1::Secp256k1<secp256k1::VerifyOnly>,
}

impl DaemonControl {
    pub fn new(
        config: Config,
        bitcoin: sync::Arc<sync::Mutex<dyn BitcoinInterface>>,
        db: sync::Arc<sync::Mutex<dyn DatabaseInterface>>,
        secp: secp256k1::Secp256k1<secp256k1::VerifyOnly>,
    ) -> DaemonControl {
        DaemonControl {
            config,
            bitcoin,
            db,
            secp,
        }
    }

    // Useful for unit test to directly mess up with the DB
    #[cfg(test)]
    pub fn db(&self) -> sync::Arc<sync::Mutex<dyn DatabaseInterface>> {
        self.db.clone()
    }
}

pub struct DaemonHandle {
    pub control: DaemonControl,
    bitcoin_poller: poller::Poller,
}

impl DaemonHandle {
    /// This starts the Liana daemon. Call `shutdown` to shut it down.
    ///
    /// You may specify a custom Bitcoin interface through the `bitcoin` parameter. If `None`, the
    /// default Bitcoin interface (`bitcoind` JSONRPC) will be used.
    /// You may specify a custom Database interface through the `db` parameter. If `None`, the
    /// default Database interface (SQLite) will be used.
    ///
    /// **Note**: we internally use threads, and set a panic hook. A downstream application must
    /// not overwrite this panic hook.
    pub fn start(
        config: Config,
        bitcoin: Option<impl BitcoinInterface + 'static>,
        db: Option<impl DatabaseInterface + 'static>,
    ) -> Result<Self, StartupError> {
        #[cfg(not(test))]
        setup_panic_hook();

        let secp = secp256k1::Secp256k1::verification_only();

        // First, check the data directory
        let mut data_dir = config
            .data_dir()
            .ok_or(StartupError::DefaultDataDirNotFound)?;
        data_dir.push(config.bitcoin_config.network.to_string());
        let fresh_data_dir = !data_dir.as_path().exists();
        if fresh_data_dir {
            create_datadir(&data_dir)?;
            log::info!("Created a new data directory at '{}'", data_dir.display());
        }

        // Then set up the database
        let db = match db {
            Some(db) => sync::Arc::from(sync::Mutex::from(db)),
            None => sync::Arc::from(sync::Mutex::from(setup_sqlite(
                &config,
                &data_dir,
                fresh_data_dir,
                &secp,
            )?)) as sync::Arc<sync::Mutex<dyn DatabaseInterface>>,
        };

        // Now, set up the Bitcoin interface.
        let bit = match bitcoin {
            Some(bit) => sync::Arc::from(sync::Mutex::from(bit)),
            None => sync::Arc::from(sync::Mutex::from(setup_bitcoind(
                &config,
                &data_dir,
                fresh_data_dir,
            )?)) as sync::Arc<sync::Mutex<dyn BitcoinInterface>>,
        };

        // If we are on a UNIX system and they told us to daemonize, do it now.
        // NOTE: it's safe to daemonize now, as we don't carry any open DB connection
        // https://www.sqlite.org/howtocorrupt.html#_carrying_an_open_database_connection_across_a_fork_
        #[cfg(unix)]
        if config.daemon {
            log::info!("Daemonizing");
            let log_file = data_dir.as_path().join("log");
            let pid_file = data_dir.as_path().join("lianad.pid");
            unsafe {
                daemonize::daemonize(&data_dir, &log_file, &pid_file)
                    .map_err(StartupError::Daemonization)?;
            }
        }

        // Spawn the bitcoind poller with a retry limit high enough that we'd fail after that.
        let bitcoin_poller = poller::Poller::start(
            bit.clone(),
            db.clone(),
            config.bitcoin_config.poll_interval_secs,
            config.main_descriptor.clone(),
        );

        // Finally, set up the API.
        let control = DaemonControl::new(config, bit, db, secp);

        Ok(Self {
            control,
            bitcoin_poller,
        })
    }

    /// Start the Liana daemon with the default Bitcoin and database interfaces (`bitcoind` RPC
    /// and SQLite).
    pub fn start_default(config: Config) -> Result<DaemonHandle, StartupError> {
        DaemonHandle::start(config, Option::<BitcoinD>::None, Option::<SqliteDb>::None)
    }

    /// Start the JSONRPC server and listen for incoming commands until we die.
    /// Like DaemonHandle::shutdown(), this stops the Bitcoin poller at teardown.
    #[cfg(feature = "jsonrpc_server")]
    pub fn rpc_server(self) -> Result<(), io::Error> {
        let DaemonHandle {
            control,
            bitcoin_poller: poller,
        } = self;

        let rpc_socket: path::PathBuf = [
            control
                .config
                .data_dir()
                .expect("Didn't fail at startup, must not now")
                .as_path(),
            path::Path::new(&control.config.bitcoin_config.network.to_string()),
            path::Path::new("lianad_rpc"),
        ]
        .iter()
        .collect();
        let listener = rpcserver_setup(&rpc_socket)?;
        log::info!("JSONRPC server started.");

        rpcserver_loop(listener, control)?;
        log::info!("JSONRPC server stopped.");

        poller.stop();

        Ok(())
    }

    // NOTE: this moves out the data as it should not be reused after shutdown
    /// Shut down the Liana daemon.
    pub fn shutdown(self) {
        self.bitcoin_poller.stop();
    }

    // We need a shutdown utility that does not move for implementing Drop for the DummyLiana
    #[cfg(test)]
    pub fn test_shutdown(&mut self) {
        self.bitcoin_poller.test_stop();
    }
}

#[cfg(all(test, unix))]
mod tests {
    use super::*;
    use crate::{
        config::{BitcoinConfig, BitcoindConfig},
        descriptors::MultipathDescriptor,
        testutils::*,
    };

    use miniscript::bitcoin;
    use std::{
        fs,
        io::{BufRead, BufReader, Write},
        net, path,
        str::FromStr,
        thread, time,
    };

    // Read all bytes from the socket until the end of a JSON object, good enough approximation.
    fn read_til_json_end(stream: &mut net::TcpStream) {
        stream
            .set_read_timeout(Some(time::Duration::from_secs(5)))
            .unwrap();
        let mut reader = BufReader::new(stream);
        loop {
            let mut line = String::new();
            reader.read_line(&mut line).unwrap();

            if line.starts_with("Authorization") {
                let mut buf = vec![0; 256];
                reader.read_until(b'}', &mut buf).unwrap();
                return;
            }
        }
    }

    // Respond to the two "echo" sent at startup to sanity check the connection
    fn complete_sanity_check(server: &net::TcpListener) {
        let echo_resp =
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":[]}\n".as_bytes();

        // Read the first echo, respond to it
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(echo_resp).unwrap();
        stream.flush().unwrap();

        // Read the second echo, respond to it
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(echo_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a pruned getblockchaininfo telling them we are at version 24.0
    fn complete_version_check(server: &net::TcpListener) {
        let net_resp =
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"version\":240000}}\n"
                .as_bytes();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a pruned getblockchaininfo telling them we are on mainnet
    fn complete_network_check(server: &net::TcpListener) {
        let net_resp =
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"chain\":\"main\"}}\n"
                .as_bytes();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them responses for the calls involved when creating a fresh wallet
    fn complete_wallet_creation(server: &net::TcpListener) {
        let net_resp =
            ["HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":[]}\n".as_bytes()]
                .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();

        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"name\":\"dummy\"}}\n"
                .as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();

        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":[{\"success\":true}]}\n"
                .as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a dummy result to loadwallet.
    fn complete_wallet_loading(server: &net::TcpListener) {
        let listwallets_resp =
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":[]}\n".as_bytes();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(listwallets_resp).unwrap();
        stream.flush().unwrap();

        let loadwallet_resp =
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"name\":\"dummy\"}}\n"
                .as_bytes();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(loadwallet_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a response to 'listwallets' with the watchonly wallet path
    fn complete_wallet_check(server: &net::TcpListener, watchonly_wallet_path: &str) {
        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":[\"".as_bytes(),
            watchonly_wallet_path.as_bytes(),
            "\"]}\n".as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a response to 'listdescriptors' with the receive and change descriptors
    fn complete_desc_check(server: &net::TcpListener, receive_desc: &str, change_desc: &str) {
        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"descriptors\":[{\"desc\":\"".as_bytes(),
            receive_desc.as_bytes(),
            "\",\"timestamp\":0},".as_bytes(),
            "{\"desc\":\"".as_bytes(),
            change_desc.as_bytes(),
            "\",\"timestamp\":1}]}}\n".as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a response to 'getblockhash' with the genesis block hash
    fn complete_tip_init(server: &net::TcpListener) {
        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":\"000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f\"}\n".as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();
    }

    // Send them a response to 'getblockchaininfo' saying we are far from being synced
    fn complete_sync_check(server: &net::TcpListener) {
        let net_resp = [
            "HTTP/1.1 200\n\r\n{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":{\"verificationprogress\":0.1}}\n".as_bytes(),
        ]
        .concat();
        let (mut stream, _) = server.accept().unwrap();
        read_til_json_end(&mut stream);
        stream.write_all(&net_resp).unwrap();
        stream.flush().unwrap();
    }

    // TODO: we could move the dummy bitcoind thread stuff to the bitcoind module to test the
    // bitcoind interface, and use the DummyLiana from testutils to sanity check the startup.
    // Note that startup as checked by this unit test is also tested in the functional test
    // framework.
    #[test]
    fn daemon_startup() {
        let tmp_dir = tmp_dir();
        fs::create_dir_all(&tmp_dir).unwrap();
        let data_dir: path::PathBuf = [tmp_dir.as_path(), path::Path::new("datadir")]
            .iter()
            .collect();
        let wo_path: path::PathBuf = [
            data_dir.as_path(),
            path::Path::new("bitcoin"),
            path::Path::new("lianad_watchonly_wallet"),
        ]
        .iter()
        .collect();
        let wo_path = wo_path.to_str().unwrap().to_string();

        // Configure a dummy bitcoind
        let network = bitcoin::Network::Bitcoin;
        let cookie: path::PathBuf = [
            tmp_dir.as_path(),
            path::Path::new(&format!(
                "dummy_bitcoind_{:?}.cookie",
                thread::current().id()
            )),
        ]
        .iter()
        .collect();
        fs::write(&cookie, [0; 32]).unwrap(); // Will overwrite should it exist already
        let addr: net::SocketAddr =
            net::SocketAddrV4::new(net::Ipv4Addr::new(127, 0, 0, 1), 0).into();
        let server = net::TcpListener::bind(addr).unwrap();
        let addr = server.local_addr().unwrap();
        let bitcoin_config = BitcoinConfig {
            network,
            poll_interval_secs: time::Duration::from_secs(2),
        };
        let bitcoind_config = BitcoindConfig {
            addr,
            cookie_path: cookie,
        };

        // Create a dummy config with this bitcoind
        let desc_str = "wsh(andor(pk(xpub68JJTXc1MWK8KLW4HGLXZBJknja7kDUJuFHnM424LbziEXsfkh1WQCiEjjHw4zLqSUm4rvhgyGkkuRowE9tCJSgt3TQB5J3SKAbZ2SdcKST/<0;1>/*),older(10000),pk(xpub68JJTXc1MWK8PEQozKsRatrUHXKFNkD1Cb1BuQU9Xr5moCv87anqGyXLyUd4KpnDyZgo3gz4aN1r3NiaoweFW8UutBsBbgKHzaD5HkTkifK/<0;1>/*)))#yudtr0k5";
        let desc = MultipathDescriptor::from_str(desc_str).unwrap();
        let receive_desc = desc.receive_descriptor().clone();
        let change_desc = desc.change_descriptor().clone();
        let config = Config {
            bitcoin_config,
            bitcoind_config: Some(bitcoind_config),
            data_dir: Some(data_dir),
            #[cfg(unix)]
            daemon: false,
            log_level: log::LevelFilter::Debug,
            main_descriptor: desc,
        };

        // Start the daemon in a new thread so the current one acts as the bitcoind server.
        let daemon_thread = thread::spawn({
            let config = config.clone();
            move || {
                let handle = DaemonHandle::start_default(config).unwrap();
                handle.shutdown();
            }
        });
        complete_sanity_check(&server);
        complete_wallet_creation(&server);
        complete_wallet_loading(&server);
        complete_version_check(&server);
        complete_network_check(&server);
        complete_wallet_check(&server, &wo_path);
        complete_desc_check(&server, &receive_desc.to_string(), &change_desc.to_string());
        complete_tip_init(&server);
        complete_sync_check(&server);
        daemon_thread.join().unwrap();

        // The datadir is created now, so if we restart it it won't create the wo wallet.
        let daemon_thread = thread::spawn(move || {
            let handle = DaemonHandle::start_default(config).unwrap();
            handle.shutdown();
        });
        complete_sanity_check(&server);
        complete_wallet_loading(&server);
        complete_version_check(&server);
        complete_network_check(&server);
        complete_wallet_check(&server, &wo_path);
        complete_desc_check(&server, &receive_desc.to_string(), &change_desc.to_string());
        complete_sync_check(&server);
        daemon_thread.join().unwrap();

        fs::remove_dir_all(&tmp_dir).unwrap();
    }
}