net: add bound_endpoint procedure

core/net/socket.odin

@@ -134,6 +134,13 @@ listen_tcp :: proc(interface_endpoint: Endpoint, backlog := 1000) -> (socket: TC
 	return _listen_tcp(interface_endpoint, backlog)
 }
 
+/*
+	Returns the endpoint that the given socket is listening / bound on.
+*/
+bound_endpoint :: proc(socket: Any_Socket) -> (endpoint: Endpoint, err: Network_Error) {
+	return _bound_endpoint(socket)
+}
+
 accept_tcp :: proc(socket: TCP_Socket, options := default_tcp_options) -> (client: TCP_Socket, source: Endpoint, err: Network_Error) {
 	return _accept_tcp(socket, options)
 }

core/net/socket_darwin.odin

@@ -22,6 +22,7 @@ package net
 
 import "core:c"
 import "core:os"
+import "core:sys/posix"
 import "core:time"
 
 Socket_Option :: enum c.int {
@@ -138,6 +139,19 @@ _listen_tcp :: proc(interface_endpoint: Endpoint, backlog := 1000) -> (skt: TCP_
 	return
 }
 
+@(private)
+_bound_endpoint :: proc(sock: Any_Socket) -> (ep: Endpoint, err: Network_Error) {
+	addr: posix.sockaddr_storage
+	addr_len := posix.socklen_t(size_of(addr))
+	res := posix.getsockname(posix.FD(any_socket_to_socket(sock)), (^posix.sockaddr)(&addr), &addr_len)
+	if res != .OK {
+		err = Listen_Error(posix.errno())
+		return
+	}
+	ep = _sockaddr_to_endpoint((^os.SOCKADDR_STORAGE_LH)(&addr))
+	return
+}
+
 @(private)
 _accept_tcp :: proc(sock: TCP_Socket, options := default_tcp_options) -> (client: TCP_Socket, source: Endpoint, err: Network_Error) {
 	sockaddr: os.SOCKADDR_STORAGE_LH

core/net/socket_freebsd.odin

@@ -149,6 +149,20 @@ _listen_tcp :: proc(interface_endpoint: Endpoint, backlog := 1000) -> (socket: T
 	return
 }
 
+@(private)
+_bound_endpoint :: proc(sock: Any_Socket) -> (ep: Endpoint, err: Network_Error) {
+	sockaddr: freebsd.Socket_Address_Storage
+
+	errno := freebsd.getsockname(cast(Fd)any_socket_to_socket(sock), &sockaddr)
+	if errno != nil {
+		err = cast(Listen_Error)errno
+		return
+	}
+
+	ep = _sockaddr_to_endpoint(&sockaddr)
+	return
+}
+
 @(private)
 _accept_tcp :: proc(sock: TCP_Socket, options := default_tcp_options) -> (client: TCP_Socket, source: Endpoint, err: Network_Error) {
 	sockaddr: freebsd.Socket_Address_Storage

core/net/socket_linux.odin

@@ -202,6 +202,19 @@ _listen_tcp :: proc(endpoint: Endpoint, backlog := 1000) -> (TCP_Socket, Network
 	return cast(TCP_Socket) os_sock, nil
 }
 
+@(private)
+_bound_endpoint :: proc(sock: Any_Socket) -> (ep: Endpoint, err: Network_Error) {
+	addr: linux.Sock_Addr_Any
+	errno := linux.getsockname(_unwrap_os_socket(sock), &addr)
+	if errno != .NONE {
+		err = Listen_Error(errno)
+		return
+	}
+
+	ep = _wrap_os_addr(addr)
+	return
+}
+
 @(private)
 _accept_tcp :: proc(sock: TCP_Socket, options := default_tcp_options) -> (tcp_client: TCP_Socket, endpoint: Endpoint, err: Network_Error) {
 	addr: linux.Sock_Addr_Any

core/net/socket_windows.odin

@@ -120,6 +120,19 @@ _listen_tcp :: proc(interface_endpoint: Endpoint, backlog := 1000) -> (socket: T
 	return
 }
 
+@(private)
+_bound_endpoint :: proc(sock: Any_Socket) -> (ep: Endpoint, err: Network_Error) {
+	sockaddr: win.SOCKADDR_STORAGE_LH
+	sockaddrlen := c.int(size_of(sockaddr))
+	if win.getsockname(win.SOCKET(any_socket_to_socket(sock)), &sockaddr, &sockaddrlen) == win.SOCKET_ERROR {
+		err = Listen_Error(win.WSAGetLastError())
+		return
+	}
+
+	ep = _sockaddr_to_endpoint(&sockaddr)
+	return
+}
+
 @(private)
 _accept_tcp :: proc(sock: TCP_Socket, options := default_tcp_options) -> (client: TCP_Socket, source: Endpoint, err: Network_Error) {
 	for {
@@ -368,4 +381,4 @@ _sockaddr_to_endpoint :: proc(native_addr: ^win.SOCKADDR_STORAGE_LH) -> (ep: End
 		panic("native_addr is neither IP4 or IP6 address")
 	}
 	return
-}
+}

core/os/os_darwin.odin

@@ -204,7 +204,7 @@ ENOPROTOOPT     :: _Platform_Error.ENOPROTOOPT
 EPROTONOSUPPORT :: _Platform_Error.EPROTONOSUPPORT
 ESOCKTNOSUPPORT :: _Platform_Error.ESOCKTNOSUPPORT
 ENOTSUP         :: _Platform_Error.ENOTSUP
-EOPNOTSUPP 	:: _Platform_Error.EOPNOTSUPP
+EOPNOTSUPP 	    :: _Platform_Error.EOPNOTSUPP
 EPFNOSUPPORT    :: _Platform_Error.EPFNOSUPPORT
 EAFNOSUPPORT    :: _Platform_Error.EAFNOSUPPORT
 EADDRINUSE      :: _Platform_Error.EADDRINUSE

core/sys/freebsd/syscalls.odin

@@ -21,6 +21,7 @@ SYS_close      : uintptr : 6
 SYS_getpid     : uintptr : 20
 SYS_recvfrom   : uintptr : 29
 SYS_accept     : uintptr : 30
+SYS_getsockname: uintptr : 32
 SYS_fcntl      : uintptr : 92
 SYS_fsync      : uintptr : 95
 SYS_socket     : uintptr : 97
@@ -201,6 +202,26 @@ accept_nil :: proc "contextless" (s: Fd) -> (Fd, Errno) {
 
 accept :: proc { accept_T, accept_nil }
 
+// Get socket name.
+//
+// The getsockname() system call appeared in 4.2BSD.
+getsockname :: proc "contextless" (s: Fd, sockaddr: ^$T) -> Errno {
+	// sockaddr must contain a valid pointer, or this will segfault because
+	// we're telling the syscall that there's memory available to write to.
+	addrlen: socklen_t = size_of(T)
+
+	result, ok := intrinsics.syscall_bsd(SYS_getsockname,
+		cast(uintptr)s,
+		cast(uintptr)sockaddr,
+		cast(uintptr)&addrlen)
+
+	if !ok {
+		return cast(Errno)result
+	}
+
+	return nil
+}
+
 // Synchronize changes to a file.
 //
 // The fsync() system call appeared in 4.2BSD.