Provide access to getsockname()/getpeername()

Port of #3323 with added tests

lib/pure/asyncnet.nim

@@ -166,6 +166,18 @@ proc newAsyncSocket*(domain: Domain = AF_INET, sockType: SockType = SOCK_STREAM,
     raiseOSError(osLastError())
   result = newAsyncSocket(fd, domain, sockType, protocol, buffered)
 
+proc getLocalAddr*(socket: AsyncSocket): (string, Port) =
+  ## Get the socket's local address and port number.
+  ##
+  ## This is high-level interface for `getsockname`:idx:.
+  getLocalAddr(socket.fd, socket.domain)
+
+proc getPeerAddr*(socket: AsyncSocket): (string, Port) =
+  ## Get the socket's peer address and port number.
+  ##
+  ## This is high-level interface for `getpeername`:idx:.
+  getPeerAddr(socket.fd, socket.domain)
+
 proc newAsyncSocket*(domain, sockType, protocol: cint,
     buffered = true): AsyncSocket =
   ## Creates a new asynchronous socket.

tests/async/tasyncawait.nim

@@ -26,6 +26,10 @@ proc launchSwarm(port: Port) {.async.} =
 proc readMessages(client: AsyncFD) {.async.} =
   # wrapping the AsyncFd into a AsyncSocket object
   var sockObj = newAsyncSocket(client)
+  var (ipaddr, port) = sockObj.getPeerAddr()
+  doAssert ipaddr == "127.0.0.1"
+  (ipaddr, port) = sockObj.getLocalAddr()
+  doAssert ipaddr == "127.0.0.1"
   while true:
     var line = await recvLine(sockObj)
     if line == "":