sausage/host/src/api/server.rs

//! The host HTTP listener and console startup share one owned API and credentials store.
use super::Api;
use crate::cred::{Caller, Cred};
use std::{net::SocketAddr, path::Path, sync::Arc};

#[derive(Clone, Debug, clap::Args)]
pub struct Options {
    /// Address of the host's approval, enrollment, and secret-entry listener.
    #[arg(long, default_value = "127.0.0.1:8081")]
    pub api_listen: SocketAddr,
    /// WebAuthn relying-party ID for the host pages.
    #[arg(long, default_value = "localhost")]
    pub api_rp_id: String,
    /// Browser origin of the host pages, not the world's origin.
    #[arg(long, default_value = "http://localhost:8081")]
    pub api_origin: String,
}

pub struct Listener {
    server: Arc<tiny_http::Server>,
    thread: Option<std::thread::JoinHandle<()>>,
}
impl Listener {
    pub fn start(cred: Arc<Cred>, host_dir: &Path, options: Options) -> anyhow::Result<Self> {
        let api = Arc::new(Api::open(
            cred,
            host_dir,
            &options.api_rp_id,
            &options.api_origin,
        )?);
        Self::start_with_api(api, options)
    }
    pub fn start_with_api(api: Arc<Api>, options: Options) -> anyhow::Result<Self> {
        let server = Arc::new(
            tiny_http::Server::http(options.api_listen)
                .map_err(|_| anyhow::anyhow!("host API address unavailable"))?,
        );
        let serving = server.clone();
        let thread = std::thread::spawn(move || {
            let runtime = tokio::runtime::Builder::new_current_thread()
                .enable_all()
                .build()
                .expect("API runtime");
            for mut request in serving.incoming_requests() {
                let response = (|| -> anyhow::Result<_> {
                    let mut body = Vec::new();
                    request.as_reader().read_to_end(&mut body)?;
                    let request = http::Request::builder()
                        .method(request.method().as_str())
                        .uri(request.url())
                        .body(bytes::Bytes::from(body))?;
                    Ok(runtime.block_on(super::handle(
                        &api,
                        Caller {
                            program: "/host/browser".into(),
                            pid: std::process::id(),
                            conversations: Vec::new(),
                        },
                        request,
                    )))
                })();
                let response = response.unwrap_or_else(|_| {
                    http::Response::builder()
                        .status(400)
                        .header("content-type", "application/json")
                        .body(bytes::Bytes::from_static(
                            b"{\"error\":\"invalid_request\",\"message\":\"invalid_request\"}",
                        ))
                        .expect("static response")
                });
                let content_type = response.headers()["content-type"].as_bytes();
                let reply = tiny_http::Response::from_data(response.body().to_vec())
                    .with_status_code(response.status().as_u16())
                    .with_header(
                        tiny_http::Header::from_bytes(b"Content-Type", content_type)
                            .expect("static header"),
                    );
                let _ = request.respond(reply);
            }
        });
        Ok(Self {
            server,
            thread: Some(thread),
        })
    }
    pub fn address(&self) -> SocketAddr {
        self.server.server_addr().to_ip().expect("TCP listener")
    }
}
impl Drop for Listener {
    fn drop(&mut self) {
        self.server.unblock();
        if let Some(thread) = self.thread.take() {
            let _ = thread.join();
        }
    }
}

/// Preserve the console lifecycle with one API for guests and host pages.
pub async fn run_with_userland(
    path: &Path,
    userland: Option<&Path>,
    options: Options,
) -> anyhow::Result<()> {
    let world = crate::world::World::open_with_userland(path, userland)?;
    let cred = Arc::new(Cred::open(&world.host_dir)?);
    let api = Arc::new(Api::open(
        cred.clone(),
        &world.host_dir,
        &options.api_rp_id,
        &options.api_origin,
    )?);
    let runtime = crate::process::Runtime::new_with_hooks(
        crate::world::World {
            root: world.root.clone(),
            host_dir: world.host_dir.clone(),
            processes: world.processes.clone(),
        },
        cred.clone(),
        crate::process::default_script(),
        Some(api.clone()),
    )?;
    let (sender, receiver) = crate::harness::input::channel();
    api.attach_harness(sender.clone());
    let listener = Listener::start_with_api(api, options)?;
    runtime
        .network_policy()
        .deny_host_port(listener.address().port());
    let services = crate::process::supervise(runtime.clone());
    let result = tokio::task::spawn_blocking(move || -> anyhow::Result<()> {
        tokio::runtime::Builder::new_current_thread()
            .enable_all()
            .build()?
            .block_on(crate::harness::run_console_with_input(
                world,
                Arc::new(runtime),
                cred,
                sender,
                receiver,
            ))
    })
    .await
    .map_err(anyhow::Error::from)
    .and_then(|result| result)
    .map_err(|error| {
        let mut text = error.to_string();
        for key in ["PI_PROXY_BASE_URL", "PI_PROXY_API_KEY"] {
            if let Ok(value) = std::env::var(key)
                && !value.is_empty()
            {
                text = text.replace(&value, "[redacted]");
            }
        }
        anyhow::anyhow!(text)
    });
    services.shutdown().await;
    drop(listener);
    result
}