package luv

Binds uv_udp_t.

Note that values of this type can be passed to functions in Luv.Handle, in addition to the functions in this module. In particular, see Luv.Handle.close.

Allocates and initializes a UDP socket.

Binds uv_udp_init_ex.

On libuv prior to 1.7.0, using ?domain causes this function to return Error `ENOSYS ("Function not implemented").

?recvmmsg is requires Luv 0.5.2 and libuv 1.37.0. Passing it with earlier libuv has no effect.

Feature checks:

• Luv.Require.(has udp_init_ex)
• Luv.Require.(has udp_recvmmg)

Wraps an existing socket in a libuv UDP handle.

Binds uv_udp_open.

Assigns an address to the given UDP handle.

Binds uv_udp_bind. See bind(3p).

Retrieves the address assigned to the given UDP handle.

Binds uv_udp_getsockname. See getsockname(3p).

Binds uv_membership.

Sets multicast group membership.

Binds uv_udp_set_membership.

Sets source-specific multicast group membership.

Binds uv_udp_set_source_membership.

Requires libuv 1.32.0.

Feature check: Luv.Require.(has udp_set_source_membership)

Sets multicast loopback.

Binds uv_udp_set_multicast_loop.

Sets the multicast TTL.

Binds uv_udp_set_multicast_ttl.

Sets the interface to be used for multicast.

Binds uv_udp_set_multicast_interface.

Sets broadcast.

Binds uv_udp_set_broadcast.

Sets the TTL.

Binds uv_udp_set_ttl.

Sends a datagram.

Binds uv_udp_send. See send(3p).

For connected UDP sockets, see Luv.UDP.Connected.send.

Like Luv.UDP.send, but only attempts to send the datagram immediately.

Binds uv_udp_try_send.

For connected UDP sockets, see Luv.UDP.Connected.try_send.

Binds uv_udp_flags.

Calls its callback whenever a datagram is received on the UDP socket.

Binds uv_udp_recv_start. See uv_udp_recv_cb and recv(3p).

The behavior is similar to Luv.Stream.read_start. See that function for the meaning of the ?allocate callback.

The main callback takes a Sockaddr.t option. This is usually Some sender_address, carrying the address of the peer. None usually indicates EAGAIN in libuv; libuv still calls the callback, in order to give the C user a chance to deallocate the data buffer. Since this is not usually an issue in OCaml, it is usually safe to simply ignore calls to the callback with sender address None.

The buffer can be empty (Luv.Buffer.size buffer = 0). This indicates an empty datagram.

Since UDP is connectionless, there is no EOF, and no means to indicate it.

The Recv_flag.t list callback argument can contain `PARTIAL, which indicates that the buffer allocated was too small for the datagram, a prefix of the data was received, and the rest of the datagram was dropped.

In summary, the important possible combinations of callback arguments are:

• Error _: “true” error that should be handled, reported, etc.
• Ok (_, None, _): EAGAIN inside libuv. Should typically be ignored.

• Ok (buffer, Some peer, flags): datagram received. In this case, there are additional possibilities:

  • Luv.Buffer.size buffer = 0: the datagram is empty, because an empty datagram was sent.
  • List.mem `PARTIAL flags = true: the read was partial, because the buffer was too small for the datagram.

Stops the callback provided to Luv.UDP.recv_start.

Binds uv_udp_recv_stop.

Evaluates to true if and only if the given handle was created with ~recvmmsg:true and the platform supports recvmmsg(2).

Binds uv_udp_using_recvmmsg.

Requires Luv 0.5.5 and libuv 1.39.0.

Feature check: Luv.Require.(has udp_using_recvmmsg)

Binds uv_udp_get_send_queue_size.

Binds uv_udp_get_send_queue_count.

Connected UDP sockets.