Return from EthernetInterface::poll() on errors, don't swallow them.

whitequark · whitequark · commit 1ece71a7747f · 2017-08-30T10:20:11.000Z
We still print them into our debug log though, because it has more
context; the caller may opt to ignore any poll errors and only
use the smoltcp debug log as a, well, debugging aid, or it could
print user-visible warnings to alert the user to unusual network
conditions.
diff --git a/src/iface/ethernet.rs b/src/iface/ethernet.rs
@@ -142,7 +142,7 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {
                     Ok(response) => response,
                     Err(err) => {
                         net_debug!("cannot process ingress packet: {}", err);
-                        continue
+                        return Err(err)
                     }
                 };
             processed_any = true;
@@ -151,7 +151,7 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {
                 Ok(()) => (),
                 Err(err) => {
                     net_debug!("cannot dispatch response packet: {}", err);
-                    continue
+                    return Err(err)
                 }
             }
         }
@@ -185,8 +185,10 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {
                 };
             match (device_result, socket_result) {
                 (Ok(()), Err(Error::Exhausted)) => (), // nothing to transmit
-                (Err(err), _) | (_, Err(err)) =>
-                    net_debug!("cannot dispatch egress packet: {}", err),
+                (Err(err), _) | (_, Err(err)) => {
+                    net_debug!("cannot dispatch egress packet: {}", err);
+                    return Err(err)
+                }
                 (Ok(()), Ok(())) => ()
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -142,7 +142,7 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {`
`142`	`142`	`Ok(response) => response,`
`143`	`143`	`Err(err) => {`
`144`	`144`	`net_debug!("cannot process ingress packet: {}", err);`
`145`		`- continue`
	`145`	`+ return Err(err)`
`146`	`146`	`}`
`147`	`147`	`};`
`148`	`148`	`processed_any = true;`
`@@ -151,7 +151,7 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {`
`151`	`151`	`Ok(()) => (),`
`152`	`152`	`Err(err) => {`
`153`	`153`	`net_debug!("cannot dispatch response packet: {}", err);`
`154`		`- continue`
	`154`	`+ return Err(err)`
`155`	`155`	`}`
`156`	`156`	`}`
`157`	`157`	`}`
`@@ -185,8 +185,10 @@ impl<'a, 'b, 'c, DeviceT: Device + 'a> Interface<'a, 'b, 'c, DeviceT> {`
`185`	`185`	`};`
`186`	`186`	`match (device_result, socket_result) {`
`187`	`187`	`(Ok(()), Err(Error::Exhausted)) => (), // nothing to transmit`
`188`		`- (Err(err), _) \| (_, Err(err)) =>`
`189`		`- net_debug!("cannot dispatch egress packet: {}", err),`
	`188`	`+ (Err(err), _) \| (_, Err(err)) => {`
	`189`	`+ net_debug!("cannot dispatch egress packet: {}", err);`
	`190`	`+ return Err(err)`
	`191`	`+ }`
`190`	`192`	`(Ok(()), Ok(())) => ()`
`191`	`193`	`}`
`192`	`194`	`}`