1092 lines
42 KiB
Ada
1092 lines
42 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- G N A T . S O C K E T S --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 2001-2006, AdaCore --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 2, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING. If not, write --
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-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
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-- Boston, MA 02110-1301, USA. --
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-- --
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-- As a special exception, if other files instantiate generics from this --
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-- unit, or you link this unit with other files to produce an executable, --
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-- this unit does not by itself cause the resulting executable to be --
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-- covered by the GNU General Public License. This exception does not --
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-- however invalidate any other reasons why the executable file might be --
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-- covered by the GNU Public License. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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-- This package provides an interface to the sockets communication facility
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-- provided on many operating systems. This is implemented on the following
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-- platforms:
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-- All native ports, with restrictions as follows
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-- Multicast is available only on systems which provide support for this
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-- feature, so it is not available if Multicast is not supported, or not
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-- installed. In particular Multicast is not available with the Windows
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-- version.
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-- The VMS implementation has implemented using the DECC RTL Socket API,
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-- and is thus subject to limitations in the implementation of this API.
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-- VxWorks cross ports fully implement this package
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-- This package is not yet implemented on LynxOS or other cross ports
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with Ada.Exceptions;
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with Ada.Streams;
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with Ada.Unchecked_Deallocation;
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with System;
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package GNAT.Sockets is
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-- Sockets are designed to provide a consistent communication facility
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-- between applications. This package provides an Ada-like interface
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-- similar to that proposed as part of the BSD socket layer.
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-- GNAT.Sockets has been designed with several ideas in mind
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-- This is a system independent interface. Therefore, we try as much as
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-- possible to mask system incompatibilities. Some functionalities are not
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-- available because there are not fully supported on some systems.
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-- This is a thick binding. For instance, a major effort has been done to
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-- avoid using memory addresses or untyped ints. We preferred to define
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-- streams and enumeration types. Errors are not returned as returned
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-- values but as exceptions.
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-- This package provides a POSIX-compliant interface (between two
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-- different implementations of the same routine, we adopt the one closest
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-- to the POSIX specification). For instance, using select(), the
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-- notification of an asynchronous connect failure is delivered in the
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-- write socket set (POSIX) instead of the exception socket set (NT).
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-- Here is a typical example of what you can do:
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-- with GNAT.Sockets; use GNAT.Sockets;
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-- with Ada.Text_IO;
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-- with Ada.Exceptions; use Ada.Exceptions;
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-- procedure PingPong is
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-- Group : constant String := "239.255.128.128";
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-- -- Multicast group: administratively scoped IP address
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-- task Pong is
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-- entry Start;
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-- entry Stop;
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-- end Pong;
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-- task body Pong is
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-- Address : Sock_Addr_Type;
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-- Server : Socket_Type;
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-- Socket : Socket_Type;
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-- Channel : Stream_Access;
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-- begin
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-- accept Start;
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--
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-- -- Get an Internet address of a host (here the local host name).
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-- -- Note that a host can have several addresses. Here we get
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-- -- the first one which is supposed to be the official one.
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-- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1);
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-- -- Get a socket address that is an Internet address and a port
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-- Address.Port := 5876;
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-- -- The first step is to create a socket. Once created, this
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-- -- socket must be associated to with an address. Usually only a
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-- -- server (Pong here) needs to bind an address explicitly. Most
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-- -- of the time clients can skip this step because the socket
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-- -- routines will bind an arbitrary address to an unbound socket.
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-- Create_Socket (Server);
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-- -- Allow reuse of local addresses
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-- Set_Socket_Option
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-- (Server,
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-- Socket_Level,
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-- (Reuse_Address, True));
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-- Bind_Socket (Server, Address);
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-- -- A server marks a socket as willing to receive connect events
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-- Listen_Socket (Server);
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-- -- Once a server calls Listen_Socket, incoming connects events
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-- -- can be accepted. The returned Socket is a new socket that
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-- -- represents the server side of the connection. Server remains
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-- -- available to receive further connections.
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-- Accept_Socket (Server, Socket, Address);
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-- -- Return a stream associated to the connected socket
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-- Channel := Stream (Socket);
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-- -- Force Pong to block
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-- delay 0.2;
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-- -- Receive and print message from client Ping
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-- declare
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-- Message : String := String'Input (Channel);
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-- begin
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-- Ada.Text_IO.Put_Line (Message);
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-- -- Send same message back to client Ping
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-- String'Output (Channel, Message);
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-- end;
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-- Close_Socket (Server);
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-- Close_Socket (Socket);
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-- -- Part of the multicast example
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-- -- Create a datagram socket to send connectionless, unreliable
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-- -- messages of a fixed maximum length.
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-- Create_Socket (Socket, Family_Inet, Socket_Datagram);
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-- -- Allow reuse of local addresses
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-- Set_Socket_Option
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-- (Socket,
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-- Socket_Level,
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-- (Reuse_Address, True));
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-- -- Join a multicast group
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr));
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-- -- Controls the live time of the datagram to avoid it being
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-- -- looped forever due to routing errors. Routers decrement
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-- -- the TTL of every datagram as it traverses from one network
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-- -- to another and when its value reaches 0 the packet is
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-- -- dropped. Default is 1.
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Multicast_TTL, 1));
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-- -- Want the data you send to be looped back to your host
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Multicast_Loop, True));
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-- -- If this socket is intended to receive messages, bind it
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-- -- to a given socket address.
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-- Address.Addr := Any_Inet_Addr;
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-- Address.Port := 55505;
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-- Bind_Socket (Socket, Address);
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-- -- If this socket is intended to send messages, provide the
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-- -- receiver socket address.
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-- Address.Addr := Inet_Addr (Group);
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-- Address.Port := 55506;
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-- Channel := Stream (Socket, Address);
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-- -- Receive and print message from client Ping
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-- declare
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-- Message : String := String'Input (Channel);
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-- begin
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-- -- Get the address of the sender
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-- Address := Get_Address (Channel);
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-- Ada.Text_IO.Put_Line (Message & " from " & Image (Address));
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-- -- Send same message back to client Ping
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-- String'Output (Channel, Message);
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-- end;
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-- Close_Socket (Socket);
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-- accept Stop;
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-- exception when E : others =>
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-- Ada.Text_IO.Put_Line
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-- (Exception_Name (E) & ": " & Exception_Message (E));
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-- end Pong;
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-- task Ping is
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-- entry Start;
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-- entry Stop;
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-- end Ping;
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-- task body Ping is
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-- Address : Sock_Addr_Type;
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-- Socket : Socket_Type;
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-- Channel : Stream_Access;
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-- begin
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-- accept Start;
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-- -- See comments in Ping section for the first steps
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-- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1);
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-- Address.Port := 5876;
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-- Create_Socket (Socket);
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-- Set_Socket_Option
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-- (Socket,
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-- Socket_Level,
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-- (Reuse_Address, True));
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-- -- Force Pong to block
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-- delay 0.2;
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-- -- If the client's socket is not bound, Connect_Socket will
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-- -- bind to an unused address. The client uses Connect_Socket to
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-- -- create a logical connection between the client's socket and
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-- -- a server's socket returned by Accept_Socket.
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-- Connect_Socket (Socket, Address);
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-- Channel := Stream (Socket);
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-- -- Send message to server Pong
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-- String'Output (Channel, "Hello world");
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-- -- Force Ping to block
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-- delay 0.2;
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-- -- Receive and print message from server Pong
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-- Ada.Text_IO.Put_Line (String'Input (Channel));
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-- Close_Socket (Socket);
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-- -- Part of multicast example. Code similar to Pong's one
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-- Create_Socket (Socket, Family_Inet, Socket_Datagram);
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-- Set_Socket_Option
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-- (Socket,
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-- Socket_Level,
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-- (Reuse_Address, True));
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr));
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Multicast_TTL, 1));
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-- Set_Socket_Option
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-- (Socket,
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-- IP_Protocol_For_IP_Level,
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-- (Multicast_Loop, True));
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-- Address.Addr := Any_Inet_Addr;
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-- Address.Port := 55506;
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-- Bind_Socket (Socket, Address);
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-- Address.Addr := Inet_Addr (Group);
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-- Address.Port := 55505;
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-- Channel := Stream (Socket, Address);
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-- -- Send message to server Pong
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-- String'Output (Channel, "Hello world");
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-- -- Receive and print message from server Pong
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-- declare
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-- Message : String := String'Input (Channel);
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-- begin
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-- Address := Get_Address (Channel);
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-- Ada.Text_IO.Put_Line (Message & " from " & Image (Address));
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-- end;
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-- Close_Socket (Socket);
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-- accept Stop;
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-- exception when E : others =>
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-- Ada.Text_IO.Put_Line
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-- (Exception_Name (E) & ": " & Exception_Message (E));
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-- end Ping;
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-- begin
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-- -- Indicate whether the thread library provides process
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-- -- blocking IO. Basically, if you are not using FSU threads
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-- -- the default is ok.
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-- Initialize (Process_Blocking_IO => False);
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-- Ping.Start;
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-- Pong.Start;
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-- Ping.Stop;
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-- Pong.Stop;
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-- Finalize;
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-- end PingPong;
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procedure Initialize (Process_Blocking_IO : Boolean := False);
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-- Initialize must be called before using any other socket routines. The
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-- Process_Blocking_IO parameter indicates whether the thread library
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-- provides process-blocking or thread-blocking input/output operations.
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-- In the former case (typically with FSU threads) GNAT.Sockets should be
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-- initialized with a value of True to provide task-blocking IO through an
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-- emulation mechanism. Only the first call to Initialize is taken into
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-- account (further calls will be ignored). Note that with the default
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-- value of Process_Blocking_IO, this operation is a no-op on UNIX
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-- platforms, but applications should make sure to call it if portability
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-- is expected: some platforms (such as Windows) require initialization
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-- before any other socket operations.
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procedure Finalize;
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-- After Finalize is called it is not possible to use any routines
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-- exported in by this package. This procedure is idempotent.
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type Socket_Type is private;
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-- Sockets are used to implement a reliable bi-directional point-to-point,
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-- stream-based connections between hosts. No_Socket provides a special
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-- value to denote uninitialized sockets.
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No_Socket : constant Socket_Type;
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Socket_Error : exception;
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-- There is only one exception in this package to deal with an error during
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-- a socket routine. Once raised, its message contains a string describing
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-- the error code.
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function Image (Socket : Socket_Type) return String;
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-- Return a printable string for Socket
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function To_C (Socket : Socket_Type) return Integer;
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-- Return a file descriptor to be used by external subprograms. This is
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-- useful for C functions that are not yet interfaced in this package.
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type Family_Type is (Family_Inet, Family_Inet6);
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-- Address family (or protocol family) identifies the communication domain
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-- and groups protocols with similar address formats. IPv6 will soon be
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-- supported.
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type Mode_Type is (Socket_Stream, Socket_Datagram);
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-- Stream sockets provide connection-oriented byte streams. Datagram
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-- sockets support unreliable connectionless message based communication.
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type Shutmode_Type is (Shut_Read, Shut_Write, Shut_Read_Write);
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-- When a process closes a socket, the policy is to retain any data queued
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-- until either a delivery or a timeout expiration (in this case, the data
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-- are discarded). A finer control is available through shutdown. With
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-- Shut_Read, no more data can be received from the socket. With_Write, no
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-- more data can be transmitted. Neither transmission nor reception can be
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-- performed with Shut_Read_Write.
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type Port_Type is new Natural;
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-- Classical port definition. No_Port provides a special value to
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-- denote uninitialized port. Any_Port provides a special value
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-- enabling all ports.
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Any_Port : constant Port_Type;
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No_Port : constant Port_Type;
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type Inet_Addr_Type (Family : Family_Type := Family_Inet) is private;
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-- An Internet address depends on an address family (IPv4 contains 4
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-- octets and Ipv6 contains 16 octets). Any_Inet_Addr is a special value
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-- treated like a wildcard enabling all addresses. No_Inet_Addr provides a
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-- special value to denote uninitialized inet addresses.
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Any_Inet_Addr : constant Inet_Addr_Type;
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No_Inet_Addr : constant Inet_Addr_Type;
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Broadcast_Inet_Addr : constant Inet_Addr_Type;
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type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record
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Addr : Inet_Addr_Type (Family);
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Port : Port_Type;
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end record;
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-- Socket addresses fully define a socket connection with protocol family,
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-- an Internet address and a port. No_Sock_Addr provides a special value
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-- for uninitialized socket addresses.
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No_Sock_Addr : constant Sock_Addr_Type;
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function Image (Value : Inet_Addr_Type) return String;
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-- Return an image of an Internet address. IPv4 notation consists in 4
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-- octets in decimal format separated by dots. IPv6 notation consists in
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-- 16 octets in hexadecimal format separated by colons (and possibly
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-- dots).
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function Image (Value : Sock_Addr_Type) return String;
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-- Return inet address image and port image separated by a colon
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function Inet_Addr (Image : String) return Inet_Addr_Type;
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-- Convert address image from numbers-and-dots notation into an
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-- inet address.
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-- Host entries provide complete information on a given host: the official
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-- name, an array of alternative names or aliases and array of network
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-- addresses.
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type Host_Entry_Type
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(Aliases_Length, Addresses_Length : Natural) is private;
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function Official_Name (E : Host_Entry_Type) return String;
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-- Return official name in host entry
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function Aliases_Length (E : Host_Entry_Type) return Natural;
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-- Return number of aliases in host entry
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function Addresses_Length (E : Host_Entry_Type) return Natural;
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-- Return number of addresses in host entry
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function Aliases
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(E : Host_Entry_Type;
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N : Positive := 1) return String;
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-- Return N'th aliases in host entry. The first index is 1
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function Addresses
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(E : Host_Entry_Type;
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N : Positive := 1) return Inet_Addr_Type;
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-- Return N'th addresses in host entry. The first index is 1
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Host_Error : exception;
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-- Exception raised by the two following procedures. Once raised, its
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-- message contains a string describing the error code. This exception is
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-- raised when an host entry cannot be retrieved.
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function Get_Host_By_Address
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(Address : Inet_Addr_Type;
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Family : Family_Type := Family_Inet) return Host_Entry_Type;
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-- Return host entry structure for the given Inet address. Note that no
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-- result will be returned if there is no mapping of this IP address to a
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-- host name in the system tables (host database, DNS or otherwise).
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function Get_Host_By_Name
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(Name : String) return Host_Entry_Type;
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-- Return host entry structure for the given host name. Here name is
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-- either a host name, or an IP address. If Name is an IP address, this is
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-- equivalent to Get_Host_By_Address (Inet_Addr (Name)).
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function Host_Name return String;
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-- Return the name of the current host
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type Service_Entry_Type (Aliases_Length : Natural) is private;
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-- Service entries provide complete information on a given service: the
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-- official name, an array of alternative names or aliases and the port
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-- number.
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function Official_Name (S : Service_Entry_Type) return String;
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-- Return official name in service entry
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function Port_Number (S : Service_Entry_Type) return Port_Type;
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-- Return port number in service entry
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function Protocol_Name (S : Service_Entry_Type) return String;
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-- Return Protocol in service entry (usually UDP or TCP)
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function Aliases_Length (S : Service_Entry_Type) return Natural;
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-- Return number of aliases in service entry
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function Aliases
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(S : Service_Entry_Type;
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N : Positive := 1) return String;
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-- Return N'th aliases in service entry (the first index is 1)
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function Get_Service_By_Name
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(Name : String;
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Protocol : String) return Service_Entry_Type;
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-- Return service entry structure for the given service name
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function Get_Service_By_Port
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(Port : Port_Type;
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Protocol : String) return Service_Entry_Type;
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|
-- Return service entry structure for the given service port number
|
|
|
|
Service_Error : exception;
|
|
-- Comment required ???
|
|
|
|
-- Errors are described by an enumeration type. There is only one
|
|
-- exception Socket_Error in this package to deal with an error during a
|
|
-- socket routine. Once raised, its message contains the error code
|
|
-- between brackets and a string describing the error code.
|
|
|
|
-- The name of the enumeration constant documents the error condition
|
|
|
|
type Error_Type is
|
|
(Success,
|
|
Permission_Denied,
|
|
Address_Already_In_Use,
|
|
Cannot_Assign_Requested_Address,
|
|
Address_Family_Not_Supported_By_Protocol,
|
|
Operation_Already_In_Progress,
|
|
Bad_File_Descriptor,
|
|
Software_Caused_Connection_Abort,
|
|
Connection_Refused,
|
|
Connection_Reset_By_Peer,
|
|
Destination_Address_Required,
|
|
Bad_Address,
|
|
Host_Is_Down,
|
|
No_Route_To_Host,
|
|
Operation_Now_In_Progress,
|
|
Interrupted_System_Call,
|
|
Invalid_Argument,
|
|
Input_Output_Error,
|
|
Transport_Endpoint_Already_Connected,
|
|
Too_Many_Symbolic_Links,
|
|
Too_Many_Open_Files,
|
|
Message_Too_Long,
|
|
File_Name_Too_Long,
|
|
Network_Is_Down,
|
|
Network_Dropped_Connection_Because_Of_Reset,
|
|
Network_Is_Unreachable,
|
|
No_Buffer_Space_Available,
|
|
Protocol_Not_Available,
|
|
Transport_Endpoint_Not_Connected,
|
|
Socket_Operation_On_Non_Socket,
|
|
Operation_Not_Supported,
|
|
Protocol_Family_Not_Supported,
|
|
Protocol_Not_Supported,
|
|
Protocol_Wrong_Type_For_Socket,
|
|
Cannot_Send_After_Transport_Endpoint_Shutdown,
|
|
Socket_Type_Not_Supported,
|
|
Connection_Timed_Out,
|
|
Too_Many_References,
|
|
Resource_Temporarily_Unavailable,
|
|
Unknown_Host,
|
|
Host_Name_Lookup_Failure,
|
|
Non_Recoverable_Error,
|
|
Unknown_Server_Error,
|
|
Cannot_Resolve_Error);
|
|
|
|
-- Timeval_Duration is a subtype of Standard.Duration because the full
|
|
-- range of Standard.Duration cannot be represented in the equivalent C
|
|
-- structure. Moreover, negative values are not allowed to avoid system
|
|
-- incompatibilities.
|
|
|
|
Immediate : constant := 0.0;
|
|
Forever : constant := Duration (Integer'Last) * 1.0;
|
|
|
|
subtype Timeval_Duration is Duration range Immediate .. Forever;
|
|
|
|
-- Get_Socket_Options and Set_Socket_Options manipulate options associated
|
|
-- with a socket. Options may exist at multiple protocol levels in the
|
|
-- communication stack. Socket_Level is the uppermost socket level.
|
|
|
|
type Level_Type is (
|
|
Socket_Level,
|
|
IP_Protocol_For_IP_Level,
|
|
IP_Protocol_For_UDP_Level,
|
|
IP_Protocol_For_TCP_Level);
|
|
|
|
-- There are several options available to manipulate sockets. Each option
|
|
-- has a name and several values available. Most of the time, the value is
|
|
-- a boolean to enable or disable this option.
|
|
|
|
type Option_Name is (
|
|
Keep_Alive, -- Enable sending of keep-alive messages
|
|
Reuse_Address, -- Allow bind to reuse local address
|
|
Broadcast, -- Enable datagram sockets to recv/send broadcasts
|
|
Send_Buffer, -- Set/get the maximum socket send buffer in bytes
|
|
Receive_Buffer, -- Set/get the maximum socket recv buffer in bytes
|
|
Linger, -- Shutdown wait for msg to be sent or timeout occur
|
|
Error, -- Get and clear the pending socket error
|
|
No_Delay, -- Do not delay send to coalesce packets (TCP_NODELAY)
|
|
Add_Membership, -- Join a multicast group
|
|
Drop_Membership, -- Leave a multicast group
|
|
Multicast_If, -- Set default outgoing interface for multicast packets
|
|
Multicast_TTL, -- Indicate the time-to-live of sent multicast packets
|
|
Multicast_Loop, -- Sent multicast packets are looped to local socket
|
|
Send_Timeout, -- Set timeout value for output
|
|
Receive_Timeout); -- Set timeout value for input
|
|
|
|
type Option_Type (Name : Option_Name := Keep_Alive) is record
|
|
case Name is
|
|
when Keep_Alive |
|
|
Reuse_Address |
|
|
Broadcast |
|
|
Linger |
|
|
No_Delay |
|
|
Multicast_Loop =>
|
|
Enabled : Boolean;
|
|
|
|
case Name is
|
|
when Linger =>
|
|
Seconds : Natural;
|
|
when others =>
|
|
null;
|
|
end case;
|
|
|
|
when Send_Buffer |
|
|
Receive_Buffer =>
|
|
Size : Natural;
|
|
|
|
when Error =>
|
|
Error : Error_Type;
|
|
|
|
when Add_Membership |
|
|
Drop_Membership =>
|
|
Multicast_Address : Inet_Addr_Type;
|
|
Local_Interface : Inet_Addr_Type;
|
|
|
|
when Multicast_If =>
|
|
Outgoing_If : Inet_Addr_Type;
|
|
|
|
when Multicast_TTL =>
|
|
Time_To_Live : Natural;
|
|
|
|
when Send_Timeout |
|
|
Receive_Timeout =>
|
|
Timeout : Timeval_Duration;
|
|
|
|
end case;
|
|
end record;
|
|
|
|
-- There are several controls available to manipulate sockets. Each option
|
|
-- has a name and several values available. These controls differ from the
|
|
-- socket options in that they are not specific to sockets but are
|
|
-- available for any device.
|
|
|
|
type Request_Name is (
|
|
Non_Blocking_IO, -- Cause a caller not to wait on blocking operations.
|
|
N_Bytes_To_Read); -- Return the number of bytes available to read
|
|
|
|
type Request_Type (Name : Request_Name := Non_Blocking_IO) is record
|
|
case Name is
|
|
when Non_Blocking_IO =>
|
|
Enabled : Boolean;
|
|
|
|
when N_Bytes_To_Read =>
|
|
Size : Natural;
|
|
|
|
end case;
|
|
end record;
|
|
|
|
-- A request flag allows to specify the type of message transmissions or
|
|
-- receptions. A request flag can be combination of zero or more
|
|
-- predefined request flags.
|
|
|
|
type Request_Flag_Type is private;
|
|
|
|
No_Request_Flag : constant Request_Flag_Type;
|
|
-- This flag corresponds to the normal execution of an operation
|
|
|
|
Process_Out_Of_Band_Data : constant Request_Flag_Type;
|
|
-- This flag requests that the receive or send function operates on
|
|
-- out-of-band data when the socket supports this notion (e.g.
|
|
-- Socket_Stream).
|
|
|
|
Peek_At_Incoming_Data : constant Request_Flag_Type;
|
|
-- This flag causes the receive operation to return data from the
|
|
-- beginning of the receive queue without removing that data from the
|
|
-- queue. A subsequent receive call will return the same data.
|
|
|
|
Wait_For_A_Full_Reception : constant Request_Flag_Type;
|
|
-- This flag requests that the operation block until the full request is
|
|
-- satisfied. However, the call may still return less data than requested
|
|
-- if a signal is caught, an error or disconnect occurs, or the next data
|
|
-- to be received is of a different type than that returned. Note that
|
|
-- this flag depends on support in the underlying sockets implementation,
|
|
-- and is not supported under Windows.
|
|
|
|
Send_End_Of_Record : constant Request_Flag_Type;
|
|
-- This flag indicates that the entire message has been sent and so this
|
|
-- terminates the record.
|
|
|
|
function "+" (L, R : Request_Flag_Type) return Request_Flag_Type;
|
|
-- Combine flag L with flag R
|
|
|
|
type Stream_Element_Reference is access all Ada.Streams.Stream_Element;
|
|
|
|
type Vector_Element is record
|
|
Base : Stream_Element_Reference;
|
|
Length : Ada.Streams.Stream_Element_Count;
|
|
end record;
|
|
|
|
type Vector_Type is array (Integer range <>) of Vector_Element;
|
|
|
|
procedure Create_Socket
|
|
(Socket : out Socket_Type;
|
|
Family : Family_Type := Family_Inet;
|
|
Mode : Mode_Type := Socket_Stream);
|
|
-- Create an endpoint for communication. Raises Socket_Error on error
|
|
|
|
procedure Accept_Socket
|
|
(Server : Socket_Type;
|
|
Socket : out Socket_Type;
|
|
Address : out Sock_Addr_Type);
|
|
-- Extracts the first connection request on the queue of pending
|
|
-- connections, creates a new connected socket with mostly the same
|
|
-- properties as Server, and allocates a new socket. The returned Address
|
|
-- is filled in with the address of the connection. Raises Socket_Error on
|
|
-- error.
|
|
|
|
procedure Bind_Socket
|
|
(Socket : Socket_Type;
|
|
Address : Sock_Addr_Type);
|
|
-- Once a socket is created, assign a local address to it. Raise
|
|
-- Socket_Error on error.
|
|
|
|
procedure Close_Socket (Socket : Socket_Type);
|
|
-- Close a socket and more specifically a non-connected socket
|
|
|
|
procedure Connect_Socket
|
|
(Socket : Socket_Type;
|
|
Server : in out Sock_Addr_Type);
|
|
-- Make a connection to another socket which has the address of
|
|
-- Server. Raises Socket_Error on error.
|
|
|
|
procedure Control_Socket
|
|
(Socket : Socket_Type;
|
|
Request : in out Request_Type);
|
|
-- Obtain or set parameter values that control the socket. This control
|
|
-- differs from the socket options in that they are not specific to
|
|
-- sockets but are available for any device.
|
|
|
|
function Get_Peer_Name (Socket : Socket_Type) return Sock_Addr_Type;
|
|
-- Return the peer or remote socket address of a socket. Raise
|
|
-- Socket_Error on error.
|
|
|
|
function Get_Socket_Name (Socket : Socket_Type) return Sock_Addr_Type;
|
|
-- Return the local or current socket address of a socket. Return
|
|
-- No_Sock_Addr on error (for instance, socket closed or not locally
|
|
-- bound).
|
|
|
|
function Get_Socket_Option
|
|
(Socket : Socket_Type;
|
|
Level : Level_Type := Socket_Level;
|
|
Name : Option_Name) return Option_Type;
|
|
-- Get the options associated with a socket. Raises Socket_Error
|
|
-- on error.
|
|
|
|
procedure Listen_Socket
|
|
(Socket : Socket_Type;
|
|
Length : Positive := 15);
|
|
-- To accept connections, a socket is first created with Create_Socket,
|
|
-- a willingness to accept incoming connections and a queue Length for
|
|
-- incoming connections are specified. Raise Socket_Error on error.
|
|
|
|
procedure Receive_Socket
|
|
(Socket : Socket_Type;
|
|
Item : out Ada.Streams.Stream_Element_Array;
|
|
Last : out Ada.Streams.Stream_Element_Offset;
|
|
Flags : Request_Flag_Type := No_Request_Flag);
|
|
-- Receive message from Socket. Last is the index value such that Item
|
|
-- (Last) is the last character assigned. Note that Last is set to
|
|
-- Item'First - 1 when the socket has been closed by peer. This is not an
|
|
-- error and no exception is raised. Flags allows to control the
|
|
-- reception. Raise Socket_Error on error.
|
|
|
|
procedure Receive_Socket
|
|
(Socket : Socket_Type;
|
|
Item : out Ada.Streams.Stream_Element_Array;
|
|
Last : out Ada.Streams.Stream_Element_Offset;
|
|
From : out Sock_Addr_Type;
|
|
Flags : Request_Flag_Type := No_Request_Flag);
|
|
-- Receive message from Socket. If Socket is not connection-oriented, the
|
|
-- source address From of the message is filled in. Last is the index
|
|
-- value such that Item (Last) is the last character assigned. Flags
|
|
-- allows to control the reception. Raises Socket_Error on error.
|
|
|
|
procedure Receive_Vector
|
|
(Socket : Socket_Type;
|
|
Vector : Vector_Type;
|
|
Count : out Ada.Streams.Stream_Element_Count);
|
|
-- Receive data from a socket and scatter it into the set of vector
|
|
-- elements Vector. Count is set to the count of received stream elements.
|
|
|
|
function Resolve_Exception
|
|
(Occurrence : Ada.Exceptions.Exception_Occurrence) return Error_Type;
|
|
-- When Socket_Error or Host_Error are raised, the exception message
|
|
-- contains the error code between brackets and a string describing the
|
|
-- error code. Resolve_Error extracts the error code from an exception
|
|
-- message and translate it into an enumeration value.
|
|
|
|
procedure Send_Socket
|
|
(Socket : Socket_Type;
|
|
Item : Ada.Streams.Stream_Element_Array;
|
|
Last : out Ada.Streams.Stream_Element_Offset;
|
|
Flags : Request_Flag_Type := No_Request_Flag);
|
|
-- Transmit a message to another socket. Note that Last is set to
|
|
-- Item'First-1 when socket has been closed by peer. This is not
|
|
-- considered an error and no exception is raised. Flags allows to control
|
|
-- the transmission. Raises Socket_Error on any other error condition.
|
|
|
|
procedure Send_Socket
|
|
(Socket : Socket_Type;
|
|
Item : Ada.Streams.Stream_Element_Array;
|
|
Last : out Ada.Streams.Stream_Element_Offset;
|
|
To : Sock_Addr_Type;
|
|
Flags : Request_Flag_Type := No_Request_Flag);
|
|
-- Transmit a message to another socket. The address is given by To. Flags
|
|
-- allows to control the transmission. Raises Socket_Error on error.
|
|
|
|
procedure Send_Vector
|
|
(Socket : Socket_Type;
|
|
Vector : Vector_Type;
|
|
Count : out Ada.Streams.Stream_Element_Count);
|
|
-- Transmit data gathered from the set of vector elements Vector to a
|
|
-- socket. Count is set to the count of transmitted stream elements.
|
|
|
|
procedure Set_Socket_Option
|
|
(Socket : Socket_Type;
|
|
Level : Level_Type := Socket_Level;
|
|
Option : Option_Type);
|
|
-- Manipulate socket options. Raises Socket_Error on error
|
|
|
|
procedure Shutdown_Socket
|
|
(Socket : Socket_Type;
|
|
How : Shutmode_Type := Shut_Read_Write);
|
|
-- Shutdown a connected socket. If How is Shut_Read, further receives will
|
|
-- be disallowed. If How is Shut_Write, further sends will be disallowed.
|
|
-- If how is Shut_Read_Write, further sends and receives will be
|
|
-- disallowed.
|
|
|
|
type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class;
|
|
-- Same interface as Ada.Streams.Stream_IO
|
|
|
|
function Stream (Socket : Socket_Type) return Stream_Access;
|
|
-- Create a stream associated with a stream-based socket that is
|
|
-- already connected.
|
|
|
|
function Stream
|
|
(Socket : Socket_Type;
|
|
Send_To : Sock_Addr_Type) return Stream_Access;
|
|
-- Create a stream associated with a datagram-based socket that is already
|
|
-- bound. Send_To is the socket address to which messages are being sent.
|
|
|
|
function Get_Address (Stream : Stream_Access) return Sock_Addr_Type;
|
|
-- Return the socket address from which the last message was received
|
|
|
|
procedure Free is new Ada.Unchecked_Deallocation
|
|
(Ada.Streams.Root_Stream_Type'Class, Stream_Access);
|
|
-- Destroy a stream created by one of the Stream functions above,
|
|
-- releasing the corresponding resources. The user is responsible for
|
|
-- calling this subprogram when the stream is not needed anymore.
|
|
|
|
type Socket_Set_Type is limited private;
|
|
-- This type allows to manipulate sets of sockets. It allows to wait for
|
|
-- events on multiple endpoints at one time. This is an access type on a
|
|
-- system dependent structure. To avoid memory leaks it is highly
|
|
-- recommended to clean the access value with procedure Empty.
|
|
|
|
procedure Clear (Item : in out Socket_Set_Type; Socket : Socket_Type);
|
|
-- Remove Socket from Item
|
|
|
|
procedure Copy (Source : Socket_Set_Type; Target : in out Socket_Set_Type);
|
|
-- Copy Source into Target as Socket_Set_Type is limited private
|
|
|
|
procedure Empty (Item : in out Socket_Set_Type);
|
|
-- Remove all Sockets from Item and deallocate internal data
|
|
|
|
procedure Get (Item : in out Socket_Set_Type; Socket : out Socket_Type);
|
|
-- Extract a Socket from socket set Item. Socket is set to
|
|
-- No_Socket when the set is empty.
|
|
|
|
function Is_Empty (Item : Socket_Set_Type) return Boolean;
|
|
-- Return True iff Item is empty
|
|
|
|
function Is_Set
|
|
(Item : Socket_Set_Type;
|
|
Socket : Socket_Type) return Boolean;
|
|
-- Return True iff Socket is present in Item
|
|
|
|
procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type);
|
|
-- Insert Socket into Item
|
|
|
|
-- The select(2) system call waits for events to occur on any of a set of
|
|
-- file descriptors. Usually, three independent sets of descriptors are
|
|
-- watched (read, write and exception). A timeout gives an upper bound
|
|
-- on the amount of time elapsed before select returns. This function
|
|
-- blocks until an event occurs. On some platforms, the select(2) system
|
|
-- can block the full process (not just the calling thread).
|
|
--
|
|
-- Check_Selector provides the very same behaviour. The only difference is
|
|
-- that it does not watch for exception events. Note that on some
|
|
-- platforms it is kept process blocking on purpose. The timeout parameter
|
|
-- allows the user to have the behaviour he wants. Abort_Selector allows
|
|
-- to abort safely a Check_Selector that is blocked forever. A special
|
|
-- file descriptor is opened by Create_Selector and included in each call
|
|
-- to Check_Selector. Abort_Selector causes an event to occur on this
|
|
-- descriptor in order to unblock Check_Selector. The user must call
|
|
-- Close_Selector to discard this special file. A reason to abort a select
|
|
-- operation is typically to add a socket in one of the socket sets when
|
|
-- the timeout is set to forever.
|
|
|
|
type Selector_Type is limited private;
|
|
type Selector_Access is access all Selector_Type;
|
|
|
|
subtype Selector_Duration is Timeval_Duration;
|
|
|
|
procedure Create_Selector (Selector : out Selector_Type);
|
|
-- Create a new selector
|
|
|
|
procedure Close_Selector (Selector : in out Selector_Type);
|
|
-- Close Selector and all internal descriptors associated; deallocate any
|
|
-- associated resources. This subprogram may be called only when there is
|
|
-- no other task still using Selector (i.e. still executing Check_Selector
|
|
-- or Abort_Selector on this Selector).
|
|
|
|
type Selector_Status is (Completed, Expired, Aborted);
|
|
|
|
procedure Check_Selector
|
|
(Selector : in out Selector_Type;
|
|
R_Socket_Set : in out Socket_Set_Type;
|
|
W_Socket_Set : in out Socket_Set_Type;
|
|
Status : out Selector_Status;
|
|
Timeout : Selector_Duration := Forever);
|
|
-- Return when one Socket in R_Socket_Set has some data to be read or if
|
|
-- one Socket in W_Socket_Set is ready to transmit some data. In these
|
|
-- cases Status is set to Completed and sockets that are ready are set in
|
|
-- R_Socket_Set or W_Socket_Set. Status is set to Expired if no socket was
|
|
-- ready after a Timeout expiration. Status is set to Aborted if an abort
|
|
-- signal has been received while checking socket status. As this
|
|
-- procedure returns when Timeout occurs, it is a design choice to keep
|
|
-- this procedure process blocking. Note that a Timeout of 0.0 returns
|
|
-- immediately. Also note that two different Socket_Set_Type objects must
|
|
-- be passed as R_Socket_Set and W_Socket_Set (even if they denote the
|
|
-- same set of Sockets), or some event may be lost.
|
|
-- Socket_Error is raised when the select(2) system call returns an
|
|
-- error condition, or when a read error occurs on the signalling socket
|
|
-- used for the implementation of Abort_Selector.
|
|
|
|
procedure Check_Selector
|
|
(Selector : in out Selector_Type;
|
|
R_Socket_Set : in out Socket_Set_Type;
|
|
W_Socket_Set : in out Socket_Set_Type;
|
|
E_Socket_Set : in out Socket_Set_Type;
|
|
Status : out Selector_Status;
|
|
Timeout : Selector_Duration := Forever);
|
|
-- This refined version of Check_Selector allows to watch for exception
|
|
-- events (that is notifications of out-of-band transmission and
|
|
-- reception). As above, all of R_Socket_Set, W_Socket_Set and
|
|
-- E_Socket_Set must be different objects.
|
|
|
|
procedure Abort_Selector (Selector : Selector_Type);
|
|
-- Send an abort signal to the selector
|
|
|
|
private
|
|
|
|
type Socket_Type is new Integer;
|
|
No_Socket : constant Socket_Type := -1;
|
|
|
|
type Selector_Type is limited record
|
|
R_Sig_Socket : Socket_Type := No_Socket;
|
|
W_Sig_Socket : Socket_Type := No_Socket;
|
|
end record;
|
|
|
|
pragma Volatile (Selector_Type);
|
|
|
|
-- The two signalling sockets are used to abort a select operation
|
|
|
|
subtype Socket_Set_Access is System.Address;
|
|
No_Socket_Set : constant Socket_Set_Access := System.Null_Address;
|
|
|
|
type Socket_Set_Type is record
|
|
Last : Socket_Type := No_Socket;
|
|
Set : Socket_Set_Access := No_Socket_Set;
|
|
end record;
|
|
|
|
subtype Inet_Addr_Comp_Type is Natural range 0 .. 255;
|
|
-- Octet for Internet address
|
|
|
|
type Inet_Addr_VN_Type is array (Natural range <>) of Inet_Addr_Comp_Type;
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|
|
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subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 .. 4);
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|
subtype Inet_Addr_V6_Type is Inet_Addr_VN_Type (1 .. 16);
|
|
|
|
type Inet_Addr_Type (Family : Family_Type := Family_Inet) is record
|
|
case Family is
|
|
when Family_Inet =>
|
|
Sin_V4 : Inet_Addr_V4_Type := (others => 0);
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|
|
|
when Family_Inet6 =>
|
|
Sin_V6 : Inet_Addr_V6_Type := (others => 0);
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|
end case;
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|
end record;
|
|
|
|
Any_Port : constant Port_Type := 0;
|
|
No_Port : constant Port_Type := 0;
|
|
|
|
Any_Inet_Addr : constant Inet_Addr_Type :=
|
|
(Family_Inet, (others => 0));
|
|
No_Inet_Addr : constant Inet_Addr_Type :=
|
|
(Family_Inet, (others => 0));
|
|
Broadcast_Inet_Addr : constant Inet_Addr_Type :=
|
|
(Family_Inet, (others => 255));
|
|
|
|
No_Sock_Addr : constant Sock_Addr_Type := (Family_Inet, No_Inet_Addr, 0);
|
|
|
|
Max_Name_Length : constant := 64;
|
|
-- The constant MAXHOSTNAMELEN is usually set to 64
|
|
|
|
subtype Name_Index is Natural range 1 .. Max_Name_Length;
|
|
|
|
type Name_Type
|
|
(Length : Name_Index := Max_Name_Length)
|
|
is record
|
|
Name : String (1 .. Length);
|
|
end record;
|
|
-- We need fixed strings to avoid access types in host entry type
|
|
|
|
type Name_Array is array (Natural range <>) of Name_Type;
|
|
type Inet_Addr_Array is array (Natural range <>) of Inet_Addr_Type;
|
|
|
|
type Host_Entry_Type (Aliases_Length, Addresses_Length : Natural) is record
|
|
Official : Name_Type;
|
|
Aliases : Name_Array (1 .. Aliases_Length);
|
|
Addresses : Inet_Addr_Array (1 .. Addresses_Length);
|
|
end record;
|
|
|
|
type Service_Entry_Type (Aliases_Length : Natural) is record
|
|
Official : Name_Type;
|
|
Aliases : Name_Array (1 .. Aliases_Length);
|
|
Port : Port_Type;
|
|
Protocol : Name_Type;
|
|
end record;
|
|
|
|
type Request_Flag_Type is mod 2 ** 8;
|
|
No_Request_Flag : constant Request_Flag_Type := 0;
|
|
Process_Out_Of_Band_Data : constant Request_Flag_Type := 1;
|
|
Peek_At_Incoming_Data : constant Request_Flag_Type := 2;
|
|
Wait_For_A_Full_Reception : constant Request_Flag_Type := 4;
|
|
Send_End_Of_Record : constant Request_Flag_Type := 8;
|
|
|
|
end GNAT.Sockets;
|