From 1bcf85dd243cd51c5e9c1e164748c804af88e657 Mon Sep 17 00:00:00 2001
From: Norman Maurer <norman.maurer@googlemail.com>
Date: Fri, 23 Mar 2018 16:02:31 +0100
Subject: [PATCH] Correctly fail EventLoopFuture for unsupported operations on
 ServerSocketChannel (#226)

Motivation:

ServerSocketChannel should just fail the EventLoopFuture for unsupported operations and not crash.

Modifications:

- Correctly fail the EventLoopFuture for unsupported operations
- Add unit test.

Result:

No more crashes when users invoke unsupported operations.
---
 Sources/NIO/SocketChannel.swift               | 12 ++++++
 Tests/NIOTests/SocketChannelTest+XCTest.swift |  3 ++
 Tests/NIOTests/SocketChannelTest.swift        | 42 +++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/Sources/NIO/SocketChannel.swift b/Sources/NIO/SocketChannel.swift
index 1c02032425..be1a636091 100644
--- a/Sources/NIO/SocketChannel.swift
+++ b/Sources/NIO/SocketChannel.swift
@@ -436,6 +436,18 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
             ch.close(promise: nil)
         }
     }
+
+    override func bufferPendingWrite(data: NIOAny, promise: EventLoopPromise<Void>?) {
+        promise?.fail(error: ChannelError.operationUnsupported)
+    }
+
+    override func markFlushPoint(promise: EventLoopPromise<Void>?) {
+        promise?.fail(error: ChannelError.operationUnsupported)
+    }
+
+    override func flushNow() -> IONotificationState {
+        return IONotificationState.unregister
+    }
 }
 
 /// A channel used with datagram sockets.
diff --git a/Tests/NIOTests/SocketChannelTest+XCTest.swift b/Tests/NIOTests/SocketChannelTest+XCTest.swift
index 3427570b4c..41202c82a1 100644
--- a/Tests/NIOTests/SocketChannelTest+XCTest.swift
+++ b/Tests/NIOTests/SocketChannelTest+XCTest.swift
@@ -36,6 +36,9 @@ extension SocketChannelTest {
                 ("testAcceptFailsWithEFAULT", testAcceptFailsWithEFAULT),
                 ("testSetGetOptionClosedServerSocketChannel", testSetGetOptionClosedServerSocketChannel),
                 ("testConnect", testConnect),
+                ("testWriteServerSocketChannel", testWriteServerSocketChannel),
+                ("testWriteAndFlushServerSocketChannel", testWriteAndFlushServerSocketChannel),
+                ("testConnectServerSocketChannel", testConnectServerSocketChannel),
            ]
    }
 }
diff --git a/Tests/NIOTests/SocketChannelTest.swift b/Tests/NIOTests/SocketChannelTest.swift
index 42c8a2e569..3841a5ef8f 100644
--- a/Tests/NIOTests/SocketChannelTest.swift
+++ b/Tests/NIOTests/SocketChannelTest.swift
@@ -219,4 +219,46 @@ public class SocketChannelTest : XCTestCase {
         try channel.closeFuture.wait()
         try promise.futureResult.wait()
     }
+
+    public func testWriteServerSocketChannel() throws {
+        let group = MultiThreadedEventLoopGroup(numThreads: 1)
+        defer { XCTAssertNoThrow(try group.syncShutdownGracefully()) }
+
+        let serverChannel = try ServerBootstrap(group: group).bind(host: "127.0.0.1", port: 0).wait()
+        do {
+            try serverChannel.write("test").wait()
+        } catch let err as ChannelError where err == .operationUnsupported {
+            // expected
+        }
+        try serverChannel.close().wait()
+    }
+
+
+    public func testWriteAndFlushServerSocketChannel() throws {
+        let group = MultiThreadedEventLoopGroup(numThreads: 1)
+        defer { XCTAssertNoThrow(try group.syncShutdownGracefully()) }
+
+        let serverChannel = try ServerBootstrap(group: group).bind(host: "127.0.0.1", port: 0).wait()
+        do {
+            try serverChannel.writeAndFlush("test").wait()
+        } catch let err as ChannelError where err == .operationUnsupported {
+            // expected
+        }
+        try serverChannel.close().wait()
+    }
+
+    
+    public func testConnectServerSocketChannel() throws {
+        let group = MultiThreadedEventLoopGroup(numThreads: 1)
+        defer { XCTAssertNoThrow(try group.syncShutdownGracefully()) }
+
+        let serverChannel = try ServerBootstrap(group: group).bind(host: "127.0.0.1", port: 0).wait()
+        do {
+            try serverChannel.connect(to: serverChannel.localAddress!).wait()
+        } catch let err as ChannelError where err == .operationUnsupported {
+            // expected
+        }
+        try serverChannel.close().wait()
+    }
+
 }