fix(yamux): set EoF when remote peer half closes the stream in yamux (#1086)

libp2p/muxers/yamux/yamux.nim

@@ -164,7 +164,6 @@ type
     closedRemotely: Future[void].Raising([])
     closedLocally: bool
     receivedData: AsyncEvent
-    returnedEof: bool
 
 proc `$`(channel: YamuxChannel): string =
   result = if channel.conn.dir == Out: "=> " else: "<= "
@@ -204,8 +203,8 @@ proc remoteClosed(channel: YamuxChannel) {.async: (raises: []).} =
 
 method closeImpl*(channel: YamuxChannel) {.async: (raises: []).} =
   if not channel.closedLocally:
+    trace "Closing yamux channel locally", streamId = channel.id, conn = channel.conn
     channel.closedLocally = true
-    channel.isEof = true
 
     if not channel.isReset and channel.sendQueue.len == 0:
       try: await channel.conn.write(YamuxHeader.data(channel.id, 0, {Fin}))
@@ -273,7 +272,7 @@ method readOnce*(
         newLPStreamClosedError()
       else:
         newLPStreamConnDownError()
-  if channel.returnedEof:
+  if channel.isEof:
     raise newLPStreamRemoteClosedError()
   if channel.recvQueue.len == 0:
     channel.receivedData.clear()
@@ -281,9 +280,8 @@ method readOnce*(
       discard await race(channel.closedRemotely, channel.receivedData.wait())
     except ValueError: raiseAssert("Futures list is not empty")
     if channel.closedRemotely.completed() and channel.recvQueue.len == 0:
-      channel.returnedEof = true
       channel.isEof = true
-      return 0
+      return 0 # we return 0 to indicate that the channel is closed for reading from now on
 
   let toRead = min(channel.recvQueue.len, nbytes)
 

libp2p/protocols/ping.nim

@@ -56,7 +56,7 @@ method init*(p: Ping) =
       trace "handling ping", conn
       var buf: array[PingSize, byte]
       await conn.readExactly(addr buf[0], PingSize)
-      trace "echoing ping", conn
+      trace "echoing ping", conn, pingData = @buf
       await conn.write(@buf)
       if not isNil(p.pingHandler):
         await p.pingHandler(conn.peerId)

tests/testrelayv2.nim

@@ -315,7 +315,6 @@ suite "Circuit Relay V2":
         await sleepAsync(chronos.timer.seconds(ttl + 1))
 
         expect(DialFailedError):
-          check: conn.atEof()
           await conn.close()
           await src.connect(rel.peerInfo.peerId, rel.peerInfo.addrs)
           conn = await src.dial(dst.peerInfo.peerId, @[ addrs ], customProtoCodec)

tests/testyamux.nim

@@ -377,3 +377,24 @@ suite "Yamux":
       expect LPStreamClosedError: discard await streamA.readLp(100)
       blocker.complete()
       await streamA.close()
+
+    asyncTest "Peer must be able to read from stream after closing it for writing":
+      mSetup()
+
+      yamuxb.streamHandler = proc(conn: Connection) {.async: (raises: []).} =
+        try:
+          check (await conn.readLp(100)) == fromHex("1234")
+        except CancelledError, LPStreamError:
+          return
+        try:
+          await conn.writeLp(fromHex("5678"))
+        except CancelledError, LPStreamError:
+          return
+        await conn.close()
+
+      let streamA = await yamuxa.newStream()
+      check streamA == yamuxa.getStreams()[0]
+
+      await streamA.writeLp(fromHex("1234"))
+      await streamA.close()
+      check (await streamA.readLp(100)) == fromHex("5678")

tests/transport-interop/Dockerfile

@@ -11,6 +11,6 @@ COPY . nim-libp2p/
 
 RUN \
   cd nim-libp2p && \
-  nim c --skipProjCfg --skipParentCfg --NimblePath:./nimbledeps/pkgs -p:nim-libp2p -d:chronicles_log_level=WARN --threads:off ./tests/transport-interop/main.nim
+  nim c --skipProjCfg --skipParentCfg --NimblePath:./nimbledeps/pkgs -p:nim-libp2p -d:chronicles_log_level=WARN -d:chronicles_default_output_device=stderr --threads:off ./tests/transport-interop/main.nim
 
 ENTRYPOINT ["/app/nim-libp2p/tests/transport-interop/main"]