Added basic AF_UNIX support to asyncnet.

Unfortunately this required some code duplication because the
doConnect() from asynccommon.nim only works with addrInfo which does not
make sense for AF_UNIX.

makeUnixAddr() was moved to nativesocket.nim and exported

lib/pure/asyncnet.nim

@@ -622,6 +622,61 @@ proc bindAddr*(socket: AsyncSocket, port = Port(0), address = "") {.
     raiseOSError(osLastError())
   freeAddrInfo(aiList)
 
+when defined(posix):
+
+  proc connectUnix*(socket: AsyncSocket, path: string): Future[void] =
+    ## Binds Unix socket to `path`.
+    ## This only works on Unix-style systems: Mac OS X, BSD and Linux
+    when not defined(nimdoc):
+      let retFuture = newFuture[void]("connectUnix")
+      result = retFuture
+  
+      proc cb(fd: AsyncFD): bool =
+        let ret = SocketHandle(fd).getSockOptInt(cint(SOL_SOCKET), cint(SO_ERROR))
+        if ret == 0:
+          retFuture.complete()
+          return true
+        elif ret == EINTR:
+          return false
+        else:
+          retFuture.fail(newException(OSError, osErrorMsg(OSErrorCode(ret))))
+          return true
+  
+      var socketAddr = makeUnixAddr(path)
+      let ret = socket.fd.connect(cast[ptr SockAddr](addr socketAddr),
+                       (sizeof(socketAddr.sun_family) + path.len).Socklen)
+      if ret == 0:
+        # Request to connect completed immediately.
+        retFuture.complete()
+      else:
+        let lastError = osLastError()
+        if lastError.int32 == EINTR or lastError.int32 == EINPROGRESS:
+          addWrite(AsyncFD(socket.fd), cb)
+        else:
+          retFuture.fail(newException(OSError, osErrorMsg(lastError)))
+
+  proc bindUnix*(socket: AsyncSocket, path: string)  {.
+    tags: [ReadIOEffect].} =
+    ## Binds Unix socket to `path`.
+    ## This only works on Unix-style systems: Mac OS X, BSD and Linux
+    when not defined(nimdoc):
+      var socketAddr = makeUnixAddr(path)
+      if socket.fd.bindAddr(cast[ptr SockAddr](addr socketAddr),
+                            (sizeof(socketAddr.sun_family) + path.len).Socklen) != 0'i32:
+        raiseOSError(osLastError())
+
+elif defined(nimdoc):
+
+  proc connectUnix*(socket: AsyncSocket, path: string): Future[void] =
+    ## Binds Unix socket to `path`.
+    ## This only works on Unix-style systems: Mac OS X, BSD and Linux
+    discard
+  
+  proc bindUnix*(socket: AsyncSocket, path: string) =
+    ## Binds Unix socket to `path`.
+    ## This only works on Unix-style systems: Mac OS X, BSD and Linux
+    discard
+
 proc close*(socket: AsyncSocket) =
   ## Closes the socket.
   defer:

lib/pure/nativesockets.nim

@@ -105,6 +105,7 @@ else:
     osInvalidSocket* = posix.INVALID_SOCKET
     nativeAfInet = posix.AF_INET
     nativeAfInet6 = posix.AF_INET6
+    nativeAfUnix = posix.AF_UNIX
 
 proc `==`*(a, b: Port): bool {.borrow.}
   ## ``==`` for ports.
@@ -482,8 +483,18 @@ proc getAddrString*(sockAddr: ptr SockAddr): string =
         raiseOSError(osLastError())
     setLen(result, len(cstring(result)))
   else:
+    when defined(posix) and not defined(nimdoc):
+      if sockAddr.sa_family.cint == nativeAfUnix:
+        return "unix"
     raise newException(IOError, "Unknown socket family in getAddrString")
 
+when defined(posix) and not defined(nimdoc):
+  proc makeUnixAddr*(path: string): Sockaddr_un =
+    result.sun_family = AF_UNIX.uint16
+    if path.len >= Sockaddr_un_path_length:
+      raise newException(ValueError, "socket path too long")
+    copyMem(addr result.sun_path, path.cstring, path.len + 1)
+
 proc getSockName*(socket: SocketHandle): Port =
   ## returns the socket's associated port number.
   var name: Sockaddr_in

lib/pure/net.nim

@@ -947,13 +947,6 @@ proc setSockOpt*(socket: Socket, opt: SOBool, value: bool, level = SOL_SOCKET) {
   var valuei = cint(if value: 1 else: 0)
   setSockOptInt(socket.fd, cint(level), toCInt(opt), valuei)
 
-when defined(posix) and not defined(nimdoc):
-  proc makeUnixAddr(path: string): Sockaddr_un =
-    result.sun_family = AF_UNIX.uint16
-    if path.len >= Sockaddr_un_path_length:
-      raise newException(ValueError, "socket path too long")
-    copyMem(addr result.sun_path, path.cstring, path.len + 1)
-
 when defined(posix) or defined(nimdoc):
   proc connectUnix*(socket: Socket, path: string) =
     ## Connects to Unix socket on `path`.