getsockname mirrors UNIX getsockname now. Added getpeername.

NEWS.md

@@ -3,6 +3,8 @@ Julia v0.7.0 Release Notes
 
 New language features
 ---------------------
+  * `getpeername` on a `TCPSocket` returns the address and port of the remote
+    endpoint of the TCP connection ([#21825]).
 
 
 Language changes
@@ -24,6 +26,9 @@ This section lists changes that do not have deprecation warnings.
 
   * Passing the same keyword argument multiple times is now a syntax error ([#16937]).
 
+  * `getsockname` on a `TCPSocket` now returns the locally bound address and port
+    of the socket. Previously the address of the remote endpoint was being
+    returned ([#21825]).
 
 Library improvements
 --------------------

base/distributed/managers.jl

@@ -481,7 +481,7 @@ function bind_client_port(s)
                             s.handle, hton(client_port[]), hton(UInt32(0)), 0)
     Base.uv_error("bind() failed", err)
 
-    _addr, port = Base._sockname(s, true)
+    _addr, port = getsockname(s)
     client_port[] = port
     return s
 end

base/exports.jl

@@ -1071,6 +1071,7 @@ export
     getaddrinfo,
     gethostname,
     getipaddr,
+    getpeername,
     getsockname,
     htol,
     hton,

base/socket.jl

@@ -827,7 +827,7 @@ function listenany(host::IPAddr, default_port)
         sock = TCPServer()
         if bind(sock, addr) && trylisten(sock) == 0
             if default_port == 0
-                _addr, port = _sockname(sock, true)
+                _addr, port = getsockname(sock)
                 return (port, sock)
             end
             return (addr.port, sock)
@@ -845,15 +845,24 @@ listenany(default_port) = listenany(IPv4(UInt32(0)), default_port)
 """
     getsockname(sock::Union{TCPServer, TCPSocket}) -> (IPAddr, UInt16)
 
-Get the IP address and the port that the given `TCPSocket` is connected to
-(or bound to, in the case of `TCPServer`).
+Get the IP address and port that the given socket is bound to.
 """
-getsockname(sock::Union{TCPServer, TCPSocket}) = _sockname(sock, isa(sock, TCPServer))
+getsockname(sock::Union{TCPSocket, TCPServer}) = _sockname(sock, true)
 
-function _sockname(sock, self)
+
+"""
+    getpeername(sock::TCPSocket) -> (IPAddr, UInt16)
+
+Get the IP address and port of the remote endpoint that the given
+socket is connected to. Valid only for connected TCP sockets.
+"""
+getpeername(sock::TCPSocket) = _sockname(sock, false)
+
+function _sockname(sock, self=true)
     rport = Ref{Cushort}(0)
     raddress = zeros(UInt8, 16)
     rfamily = Ref{Cuint}(0)
+
     if self
         r = ccall(:jl_tcp_getsockname, Int32,
                 (Ptr{Void}, Ref{Cushort}, Ptr{Void}, Ref{Cuint}),
@@ -886,7 +895,7 @@ function _sockname(sock, self)
             naddr = ntoh(unsafe_load(Ptr{UInt128}(pointer(raddress)), 1))
             addr = IPv6(naddr)
         else
-            error("unsupported address family: $(getindex(rfamily))")
+            error(string("unsupported address family: ", getindex(rfamily)))
         end
     else
         error("cannot obtain socket name")

doc/src/stdlib/io-network.md

@@ -162,6 +162,7 @@ Base.listen(::Any)
 Base.listen(::AbstractString)
 Base.getaddrinfo
 Base.getsockname
+Base.getpeername
 Base.IPv4
 Base.IPv6
 Base.nb_available

test/socket.jl

@@ -193,56 +193,35 @@ if !is_windows() || Sys.windows_version() >= Sys.WINDOWS_VISTA_VER
 end
 
 begin
-    default_port = UInt16(11011)
-    default_addr = IPv4("127.0.0.1")
+    for (addr, porthint) in [(IPv4("127.0.0.1"), UInt16(11011)),
+                        (IPv6("::1"), UInt16(11012)), (getipaddr(), UInt16(11013))]
+        port, listen_sock = listenany(addr, porthint)
+        gsn_addr, gsn_port = getsockname(listen_sock)
 
-    sock = Base.TCPServer()
-    bind(sock,Base.InetAddr(default_addr,default_port))
-    listen(sock)
+        @test addr == gsn_addr
+        @test port == gsn_port
 
-    new_addr, new_port = getsockname(sock)
+        @test_throws MethodError getpeername(listen_sock)
 
-    @test default_addr == new_addr
-    @test default_port == new_port
-    close(sock)
-end
+        # connect to it
+        client_sock = connect(addr, port)
+        server_sock = accept(listen_sock)
 
-begin
-    default_port = UInt16(21011)
-    default_addr = IPv6("::1")
+        self_client_addr, self_client_port = getsockname(client_sock)
+        peer_client_addr, peer_client_port = getpeername(client_sock)
+        self_srvr_addr, self_srvr_port = getsockname(server_sock)
+        peer_srvr_addr, peer_srvr_port = getpeername(server_sock)
 
-    sock = Base.TCPServer()
-    addr = Base.InetAddr(default_addr,default_port)
-    bind(sock,addr)
-    listen(sock)
+        @test self_client_addr == peer_client_addr == self_srvr_addr == peer_srvr_addr
 
-    new_addr, new_port = getsockname(sock)
+        @test peer_client_port == self_srvr_port
+        @test peer_srvr_port == self_client_port
+        @test self_srvr_port != self_client_port
 
-    @test default_addr == new_addr
-    @test default_port == new_port
-    close(sock)
-end
-
-begin
-    default_port = UInt16(11011)
-    default_addr = getipaddr()
-
-    sock = Base.TCPServer()
-    bind(sock,Base.InetAddr(default_addr,default_port))
-    listen(sock)
-
-    @async begin
-        sleep(1)
-        ssock = connect(default_addr, default_port)
+        close(listen_sock)
+        close(client_sock)
+        close(server_sock)
     end
-
-    csock = accept(sock)
-    new_addr, new_port = getsockname(csock)
-
-    @test default_addr == new_addr
-    @test new_port > 0
-    close(csock)
-    close(sock)
 end
 
 # Local-machine broadcast