Fix getRemoteAddress()

net/src/main/scala/epollcat/internal/net/EpollAsyncSocketChannel.scala

@@ -21,6 +21,7 @@ import epollcat.unsafe.EpollRuntime
 
 import java.io.IOException
 import java.net.ConnectException
+import java.net.InetAddress
 import java.net.InetSocketAddress
 import java.net.SocketAddress
 import java.net.SocketOption
@@ -36,6 +37,7 @@ import scala.scalanative.annotation.stub
 import scala.scalanative.libc.errno
 import scala.scalanative.posix
 import scala.scalanative.posix.netdbOps._
+import scala.scalanative.posix.netinet.inOps._
 import scala.scalanative.unsafe._
 import scala.scalanative.unsigned._
 
@@ -45,7 +47,6 @@ final class EpollAsyncSocketChannel private (fd: Int) extends AsynchronousSocket
 
   private[this] var _isOpen: Boolean = true
   private[this] var outputShutdown: Boolean = false
-  private[this] var remoteAddress: SocketAddress = null
   private[this] var readReady: Boolean = false
   private[this] var readCallback: Runnable = null
   private[this] var writeReady: Boolean = false
@@ -85,7 +86,22 @@ final class EpollAsyncSocketChannel private (fd: Int) extends AsynchronousSocket
     this
   }
 
-  def getRemoteAddress(): SocketAddress = remoteAddress
+  def getRemoteAddress(): SocketAddress = {
+    val addr = stackalloc[posix.netinet.in.sockaddr_in]()
+    val len = stackalloc[posix.sys.socket.socklen_t]()
+    !len = sizeof[posix.sys.socket.sockaddr].toUInt
+    if (posix
+        .sys
+        .socket
+        .getpeername(fd, addr.asInstanceOf[Ptr[posix.sys.socket.sockaddr]], len) == -1)
+      throw new IOException(s"getpeername: ${errno.errno}")
+    val port = posix.arpa.inet.htons(addr.sin_port).toInt
+    val addrBytes = addr.sin_addr.at1.asInstanceOf[Ptr[Byte]]
+    val inetAddr = InetAddress.getByAddress(
+      Array(addrBytes(0), addrBytes(1), addrBytes(2), addrBytes(3))
+    )
+    new InetSocketAddress(inetAddr, port)
+  }
 
   @stub
   def read[A](
@@ -214,7 +230,6 @@ final class EpollAsyncSocketChannel private (fd: Int) extends AsynchronousSocket
         return handler.failed(new IOException(s"getsockopt: ${errno.errno}"), attachment)
 
       if (!optval == 0) {
-        remoteAddress = remote
         handler.completed(null, attachment)
       } else {
         val ex = !optval match {

tests/shared/src/test/scala/epollcat/tcp/TcpSuite.scala

@@ -62,6 +62,9 @@ class TcpSuite extends EpollcatSuite {
 
     def localAddress: IO[SocketAddress] =
       IO(ch.getLocalAddress())
+
+    def remoteAddress: IO[SocketAddress] =
+      IO(ch.getRemoteAddress())
   }
 
   object IOSocketChannel {
@@ -164,6 +167,26 @@ class TcpSuite extends EpollcatSuite {
     }
   }
 
+  test("local and remote addresses") {
+    IOServerSocketChannel.open.evalTap(_.bind(new InetSocketAddress("127.0.0.1", 0))).use {
+      server =>
+        IOSocketChannel.open.use { clientCh =>
+          server.localAddress.flatMap(clientCh.connect(_)) *>
+            server.accept.use { serverCh =>
+              for {
+                serverLocal <- serverCh.localAddress
+                serverRemote <- serverCh.remoteAddress
+                clientLocal <- clientCh.localAddress
+                clientRemote <- clientCh.remoteAddress
+              } yield {
+                assertEquals(clientRemote, serverLocal)
+                assertEquals(serverRemote, clientLocal)
+              }
+            }
+        }
+    }
+  }
+
   test("read after shutdownInput") {
     IOServerSocketChannel
       .open