chiark / gitweb /
read_limited_bytes: take a `capacity` argument
[hippotat.git] / src / bin / server.rs
index f56db02d0c2271b8c16c8714d99b66a8a7a7dd46..b0bac2a64af9453b033146bc19d9ba0767cee2f5 100644 (file)
@@ -15,11 +15,39 @@ pub struct Opts {
 
 const METADATA_MAX_LEN: usize = MAX_OVERHEAD;
 
+type AllClients = HashMap<ClientName, ClientHandles>;
+
+struct ClientHandles {
+  ic: Arc<InstanceConfig>,
+  web: tokio::sync::mpsc::Sender<WebRequest>,
+}
+
+/// Sent from hyper worker pool task to client task
+#[allow(dead_code)] // xxx
+struct WebRequest {
+  // initial part of body
+  // used up to and including first 2 lines of metadata
+  // end delimiter for the metadata not yet located, but in here somewhere
+  initial: Box<[u8]>,
+  initial_remaining: usize,
+  body: hyper::body::Body,
+  reply_to: tokio::sync::oneshot::Sender<WebResponse>,
+  warnings: Warnings,
+}
+
+/// Reply from client task to hyper worker pool task
+#[allow(dead_code)] // xxx
+struct WebResponse {
+  warnings: Warnings,
+  data: Result<WebResponseData, AE>,
+}
+
+type WebResponseData = ();
+
 async fn handle(
-//    context: (),
-//    addr: SocketAddr,
-    req: hyper::Request<hyper::Body>
-) -> Result<hyper::Response<hyper::Body>, Infallible> {
+  all_clients: Arc<AllClients>,
+  req: hyper::Request<hyper::Body>
+) -> Result<hyper::Response<hyper::Body>, Void> {
   if req.method() == Method::GET {
     let mut resp = hyper::Response::new(hyper::Body::from("hippotat\r\n"));
     resp.headers_mut().insert(
@@ -57,7 +85,9 @@ async fn handle(
     };
 
     let mut body = req.into_body();
-    let initial = match read_limited_bytes(METADATA_MAX_LEN, &mut body).await {
+    let initial = match read_limited_bytes(
+      METADATA_MAX_LEN, default(), default(), &mut body
+    ).await {
       Ok(all) => all,
       Err(ReadLimitedError::Truncated { sofar,.. }) => sofar,
       Err(ReadLimitedError::Hyper(e)) => throw!(e),
@@ -78,17 +108,82 @@ async fn handle(
       r#"first multipart component must be name="m""#
     )) }
 
-    let nl = memchr::memchr2(b'\r', b'\n', comp.payload_start)
-      .ok_or_else(|| anyhow!("no newline in first metadata line?"))?;
+    let mut meta = MetadataFieldIterator::new(comp.payload_start);
+
+    let client: ClientName = meta.need_parse().context("client addr")?;
+
+    let mut hmac_got = [0; HMAC_L];
+    let (client_time, hmac_got_l) = (||{
+      let token: &str = meta.need_next().context(r#"find in "m""#)?;
+      let (time_t, hmac_b64) = token.split_once(' ')
+        .ok_or_else(|| anyhow!("split"))?;
+      let time_t = u64::from_str_radix(time_t, 16).context("parse time_t")?;
+      let l = io::copy(
+        &mut base64::read::DecoderReader::new(&mut hmac_b64.as_bytes(),
+                                              BASE64_CONFIG),
+        &mut &mut hmac_got[..]
+      ).context("parse b64 token")?;
+      let l = l.try_into()?;
+      Ok::<_,AE>((time_t, l))
+    })().context("token")?;
+    let hmac_got = &hmac_got[0..hmac_got_l];
+
+    let client = all_clients.get(&client);
 
-    let client = &comp.payload_start[0..nl];
-    let client = str::from_utf8(client).context("client addr utf-8")?;
-    let client: IpAddr = client.parse().context("client address")?;
+    // We attempt to hide whether the client exists we don't try to
+    // hide the hash lookup computationgs, but we do try to hide the
+    // HMAC computation by always doing it.  We hope that the compiler
+    // doesn't produce a specialised implementation for the dummy
+    // secret value.
+    let client_exists = subtle::Choice::from(client.is_some() as u8);
+    let secret = client.map(|c| c.ic.secret.0.as_bytes());
+    let secret = secret.unwrap_or(&[0x55; HMAC_B][..]);
+    let client_time_s = format!("{:x}", client_time);
+    let hmac_exp = token_hmac(secret, client_time_s.as_bytes());
+    // We also definitely want a consttime memeq for the hmac value
+    let hmac_ok = hmac_got.ct_eq(&hmac_exp);
+    //dbg!(DumpHex(&hmac_exp), client.is_some());
+    //dbg!(DumpHex(hmac_got), hmac_ok, client_exists);
+    if ! bool::from(hmac_ok & client_exists) {
+      throw!(anyhow!("xxx should be a 403 error"));
+    }
+
+    let client = client.unwrap();
+    let now = time_t_now();
+    let chk_skew = |a: u64, b: u64, c_ahead_behind| {
+      if let Some(a_ahead) = a.checked_sub(b) {
+        if a_ahead > client.ic.max_clock_skew.as_secs() {
+          throw!(anyhow!("too much clock skew (client {} by {})",
+                         c_ahead_behind, a_ahead));
+        }
+      }
+      Ok::<_,AE>(())
+    };
+    chk_skew(client_time, now, "ahead")?;
+    chk_skew(now, client_time, "behind")?;
+
+    let initial_remaining = meta.remaining_bytes_len();
 
-    eprintln!("boundary={:?} start={} name={:?} client={}",
-              boundary, start, &comp.name, client);
+    //eprintln!("boundary={:?} start={} name={:?} client={}",
+    // boundary, start, &comp.name, &client.ic);
 
-    Ok::<_,AE>(())
+    let (reply_to, reply_recv) = tokio::sync::oneshot::channel();
+    let wreq = WebRequest {
+      initial,
+      initial_remaining,
+      body,
+      warnings: mem::take(&mut warnings),
+      reply_to
+    };
+    trace!("{} request", &client.ic);
+
+    client.web.try_send(wreq)
+      .map_err(|_| anyhow!("client task shut down!"))?;
+
+    let reply: WebResponse = reply_recv.await?;
+    warnings = reply.warnings;
+
+    reply.data
   }.await {
     Ok(()) => {
     },
@@ -102,40 +197,159 @@ async fn handle(
   Ok(hyper::Response::new(hyper::Body::from("Hello World")))
 }
 
+#[allow(unused_variables)] // xxx
+async fn run_client(_ic: Arc<InstanceConfig>,
+                    mut web: mpsc::Receiver<WebRequest>)
+                    -> Result<Void, AE>
+{
+  struct Outstanding {
+    reply_to: tokio::sync::oneshot::Sender<WebResponse>,
+    max_requests_outstanding: u32,
+  }
+  let mut outstanding: VecDeque<Outstanding> = default();
+  let  downbound: VecDeque<(/*xxx*/)> = default();
+
+  let try_send_response = |
+    reply_to: tokio::sync::oneshot::Sender<WebResponse>,
+    response: WebResponse
+  | {
+    reply_to.send(response)
+      .unwrap_or_else(|_: WebResponse| () /* oh dear */ /* xxx trace? */);
+  };
+
+  loop {
+    if let Some(ret) = {
+      if ! downbound.is_empty() {
+        outstanding.pop_front()
+      } else if let Some((i,_)) = outstanding.iter().enumerate().find({
+        |(_,o)| outstanding.len() > o.max_requests_outstanding.sat()
+      }) {
+        Some(outstanding.remove(i).unwrap())
+      } else {
+        None
+      }
+    } {
+      let response = WebResponse {
+        data: Ok(()),
+        warnings: default(),
+      };
+
+      try_send_response(ret.reply_to, response);
+    }
+
+    select!{
+      req = web.recv() =>
+      {
+        let WebRequest {
+          initial, initial_remaining, body,
+          reply_to, warnings,
+        } = req.ok_or_else(|| anyhow!("webservers all shut down!"))?;
+
+        match async {
+
+          // xxx size limit
+
+          let whole_request = body.try_fold(
+            initial.into_vec(),
+            |mut w, by| async move { w.extend_from_slice(&by); Ok(w) },
+          ).await.context("read request body")?;
+
+          dbg!(whole_request.len());
+
+/*          
+
+          multipart::ComponentIterator::resume_mid_component(
+            &initial[initial_remaining..],
+  */          
+
+          Ok::<_,AE>(())
+        }.await {
+          Ok(()) => outstanding.push_back(Outstanding {
+            reply_to: reply_to,
+            max_requests_outstanding: 42, // xxx
+          }),
+          Err(e) => {
+            try_send_response(reply_to, WebResponse {
+              data: Err(e),
+              warnings,
+            });
+          },
+        }
+      }
+    }
+  }
+  //Err(anyhow!("xxx"))
+}
 
 #[tokio::main]
 async fn main() {
   let opts = Opts::from_args();
-  let mut hservers = vec![];
-  let (ics, global,ipif) = config::startup(
+  let mut tasks: Vec<(
+    JoinHandle<AE>,
+    String,
+  )> = vec![];
+
+  let (global, ipif) = config::startup(
     "hippotatd", LinkEnd::Server,
     &opts.config, &opts.log, |ics|
   {
     let global = config::InstanceConfigGlobal::from(&ics);
     let ipif = Ipif::start(&global.ipif, None)?;
 
-    let make_service = hyper::service::make_service_fn(|_conn| async {
-      Ok::<_, Infallible>(hyper::service::service_fn(handle))
-    });
+    let all_clients: AllClients = ics.into_iter().map(|ic| {
+      let ic = Arc::new(ic);
+
+      let (web_send, web_recv) = mpsc::channel(
+        5 // xxx should me max_requests_outstanding but that's
+          // marked client-only so needs rework
+      );
+
+      let ic_ = ic.clone();
+      tasks.push((tokio::spawn(async move {
+        run_client(ic_, web_recv).await.void_unwrap_err()
+      }), format!("client {}", &ic)));
+
+      (ic.link.client,
+       ClientHandles {
+         ic,
+         web: web_send,
+       })
+    }).collect();
+    let all_clients = Arc::new(all_clients);
 
     for addr in &global.addrs {
+      let all_clients_ = all_clients.clone();
+      let make_service = hyper::service::make_service_fn(move |_conn| {
+        let all_clients_ = all_clients_.clone();
+        async { Ok::<_, Void>( hyper::service::service_fn(move |req| {
+          handle(all_clients_.clone(), req)
+        }) ) } }
+      );
+
       let addr = SocketAddr::new(*addr, global.port);
       let server = hyper::Server::try_bind(&addr)
         .context("bind")?
         .http1_preserve_header_case(true)
         .serve(make_service);
       info!("listening on {}", &addr);
-      let task = tokio::task::spawn(server);
-      hservers.push(task);
+      let task = tokio::task::spawn(async move {
+        match server.await {
+          Ok(()) => anyhow!("shut down?!"),
+          Err(e) => e.into(),
+        }
+      });
+      tasks.push((task, format!("http server {}", addr)));
     }
-
-    Ok((ics, global, ipif))
+    
+    Ok((global, ipif))
   });
 
-  let x = future::select_all(&mut hservers).await;
-  error!("xxx hserver {:?}", &x);
+  let died = future::select_all(
+    tasks.iter_mut().map(|e| &mut e.0)
+  ).await;
+  error!("xxx {:?}", &died);
 
   ipif.quitting(None).await;
 
-  dbg!(ics, global);
+  dbg!(global);
 }