From 8e21ba311cb9fa2e9c700897b429c04e0f80749c Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 16 Aug 2021 01:07:22 +0100
Subject: [PATCH] sort out error handling for server rx slip frames

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/bin/client.rs | 10 +++++++---
 src/bin/server.rs |  2 +-
 src/slip.rs       | 22 ++++++++++++----------
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/src/bin/client.rs b/src/bin/client.rs
index 10b2076..cfb632e 100644
--- a/src/bin/client.rs
+++ b/src/bin/client.rs
@@ -282,16 +282,20 @@ async fn run_client<C:HCC>(
               let addr = ip_packet_addr::<true>(header)?;
               if addr != ic.link.client.0 { throw!(PE::Dst(addr)) }
               Ok(())
-            }, |(o,())| Ok({ rx_queue.push(o); }),
-               |e| error!("{} #{}: rx discarding: {}", &ic, req_num, e))
+            },
+            |(o,())| Ok({ rx_queue.push(o); }),
+            |e| Ok::<_,SlipFramesError<Void>>( {
+              error!("{} #{}: rx discarding: {}", &ic, req_num, e);
+            }))
             {
               Ok(()) => reporter.lock().success(),
-              Err(ErrorOnlyBad) => {
+              Err(SlipFramesError::ErrorOnlyBad) => {
                 reqs.push(Box::pin(async {
                   tokio::time::sleep(ic.http_retry).await;
                   None
                 }));
               },
+              Err(SlipFramesError::Other(v)) => unreachable!(v),
             }
           }
         },
diff --git a/src/bin/server.rs b/src/bin/server.rs
index 4a80704..73f2de5 100644
--- a/src/bin/server.rs
+++ b/src/bin/server.rs
@@ -349,7 +349,7 @@ async fn run_client(ic: Arc<InstanceConfig>,
               let daddr = ip_packet_addr::<true>(header)?;
               Ok(daddr)
             }, |(daddr,packet)| route_packet(daddr,packet),
-               |e| { let _xxx = warnings.add(&e); }
+               |e| Ok::<_,SlipFramesError<_>>({ warnings.add(&e)?; })
             )?;
           }
 
diff --git a/src/slip.rs b/src/slip.rs
index 955c36f..6bb508b 100644
--- a/src/slip.rs
+++ b/src/slip.rs
@@ -24,13 +24,14 @@ impl SlipMime for Slip2Mime { const CONV_TO: Option<bool> = Some(true); }
 impl SlipMime for Mime2Slip { const CONV_TO: Option<bool> = Some(false); }
 impl SlipMime for SlipNoConv { const CONV_TO: Option<bool> = None; }
 
-#[derive(Debug)]
-#[derive(Error)]
-#[error("only bad IP datagrams")]
-pub struct ErrorOnlyBad;
-
-#[throws(ErrorOnlyBad)]
-pub fn checkn<AC, EH, OUT, ACR, M: SlipMime+Copy>(
+#[derive(Debug,Error)]
+pub enum SlipFramesError<E> where E: std::error::Error + 'static {
+  #[error("only bad IP datagrams")] ErrorOnlyBad,
+  #[error("{0}")] Other(#[from] E),
+}
+  
+#[throws(SlipFramesError<EHE>)]
+pub fn checkn<AC, EH, EHE, OUT, ACR, M: SlipMime+Copy>(
   mime: M,
   mtu: u32,
   data: &[u8],
@@ -39,7 +40,8 @@ pub fn checkn<AC, EH, OUT, ACR, M: SlipMime+Copy>(
   mut error_handler: EH
 ) where AC: Fn(&[u8]) -> Result<ACR, PacketError> + Copy,
         OUT: FnMut((Box<[u8]>, ACR)) -> Result<(), PacketError>,
-        EH: FnMut(PacketError),
+        EH: FnMut(PacketError) -> Result<(), SlipFramesError<EHE>>,
+        EHE: std::error::Error + 'static,
 {
   //  eprintln!("before: {:?}", DumpHex(data));
   if data.is_empty() { return }
@@ -54,11 +56,11 @@ pub fn checkn<AC, EH, OUT, ACR, M: SlipMime+Copy>(
       Ok::<_,PE>(())
     })() {
       Ok(()) => { },
-      Err(e) => { err=true; error_handler(e); },
+      Err(e) => { err=true; error_handler(e)?; },
     }
   }
 //  eprintln!(" after: {:?}", DumpHex(data));
-  if err && !ok { throw!(ErrorOnlyBad) }
+  if err && !ok { throw!(SlipFramesError::ErrorOnlyBad) }
 }
 
 #[throws(PacketError)]
-- 
2.30.2