| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- G N A T . S O C K E T S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2001-2005, AdaCore -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package provides an interface to the sockets communication facility |
| -- provided on many operating systems. This is implemented on the following |
| -- platforms: |
| |
| -- All native ports, with restrictions as follows |
| |
| -- Multicast is available only on systems which provide support for this |
| -- feature, so it is not available if Multicast is not supported, or not |
| -- installed. In particular Multicast is not available with the Windows |
| -- version. |
| |
| -- The VMS implementation has implemented using the DECC RTL Socket API, |
| -- and is thus subject to limitations in the implementation of this API. |
| |
| -- VxWorks cross ports fully implement this package |
| |
| -- This package is not yet implemented on LynxOS or other cross ports |
| |
| with Ada.Exceptions; |
| with Ada.Streams; |
| with Ada.Unchecked_Deallocation; |
| |
| with System; |
| |
| package GNAT.Sockets is |
| |
| -- Sockets are designed to provide a consistent communication facility |
| -- between applications. This package provides an Ada-like interface |
| -- similar to that proposed as part of the BSD socket layer. |
| |
| -- GNAT.Sockets has been designed with several ideas in mind |
| |
| -- This is a system independent interface. Therefore, we try as much as |
| -- possible to mask system incompatibilities. Some functionalities are not |
| -- available because there are not fully supported on some systems. |
| |
| -- This is a thick binding. For instance, a major effort has been done to |
| -- avoid using memory addresses or untyped ints. We preferred to define |
| -- streams and enumeration types. Errors are not returned as returned |
| -- values but as exceptions. |
| |
| -- This package provides a POSIX-compliant interface (between two |
| -- different implementations of the same routine, we adopt the one closest |
| -- to the POSIX specification). For instance, using select(), the |
| -- notification of an asynchronous connect failure is delivered in the |
| -- write socket set (POSIX) instead of the exception socket set (NT). |
| |
| -- Here is a typical example of what you can do: |
| |
| -- with GNAT.Sockets; use GNAT.Sockets; |
| |
| -- with Ada.Text_IO; |
| -- with Ada.Exceptions; use Ada.Exceptions; |
| |
| -- procedure PingPong is |
| |
| -- Group : constant String := "239.255.128.128"; |
| -- -- Multicast group: administratively scoped IP address |
| |
| -- task Pong is |
| -- entry Start; |
| -- entry Stop; |
| -- end Pong; |
| |
| -- task body Pong is |
| -- Address : Sock_Addr_Type; |
| -- Server : Socket_Type; |
| -- Socket : Socket_Type; |
| -- Channel : Stream_Access; |
| |
| -- begin |
| -- accept Start; |
| -- |
| -- -- Get an Internet address of a host (here the local host name). |
| -- -- Note that a host can have several addresses. Here we get |
| -- -- the first one which is supposed to be the official one. |
| |
| -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); |
| |
| -- -- Get a socket address that is an Internet address and a port |
| |
| -- Address.Port := 5876; |
| |
| -- -- The first step is to create a socket. Once created, this |
| -- -- socket must be associated to with an address. Usually only a |
| -- -- server (Pong here) needs to bind an address explicitly. Most |
| -- -- of the time clients can skip this step because the socket |
| -- -- routines will bind an arbitrary address to an unbound socket. |
| |
| -- Create_Socket (Server); |
| |
| -- -- Allow reuse of local addresses |
| |
| -- Set_Socket_Option |
| -- (Server, |
| -- Socket_Level, |
| -- (Reuse_Address, True)); |
| |
| -- Bind_Socket (Server, Address); |
| |
| -- -- A server marks a socket as willing to receive connect events |
| |
| -- Listen_Socket (Server); |
| |
| -- -- Once a server calls Listen_Socket, incoming connects events |
| -- -- can be accepted. The returned Socket is a new socket that |
| -- -- represents the server side of the connection. Server remains |
| -- -- available to receive further connections. |
| |
| -- Accept_Socket (Server, Socket, Address); |
| |
| -- -- Return a stream associated to the connected socket |
| |
| -- Channel := Stream (Socket); |
| |
| -- -- Force Pong to block |
| |
| -- delay 0.2; |
| |
| -- -- Receive and print message from client Ping |
| |
| -- declare |
| -- Message : String := String'Input (Channel); |
| |
| -- begin |
| -- Ada.Text_IO.Put_Line (Message); |
| |
| -- -- Send same message back to client Ping |
| |
| -- String'Output (Channel, Message); |
| -- end; |
| |
| -- Close_Socket (Server); |
| -- Close_Socket (Socket); |
| |
| -- -- Part of the multicast example |
| |
| -- -- Create a datagram socket to send connectionless, unreliable |
| -- -- messages of a fixed maximum length. |
| |
| -- Create_Socket (Socket, Family_Inet, Socket_Datagram); |
| |
| -- -- Allow reuse of local addresses |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- Socket_Level, |
| -- (Reuse_Address, True)); |
| |
| -- -- Join a multicast group |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); |
| |
| -- -- Controls the live time of the datagram to avoid it being |
| -- -- looped forever due to routing errors. Routers decrement |
| -- -- the TTL of every datagram as it traverses from one network |
| -- -- to another and when its value reaches 0 the packet is |
| -- -- dropped. Default is 1. |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Multicast_TTL, 1)); |
| |
| -- -- Want the data you send to be looped back to your host |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Multicast_Loop, True)); |
| |
| -- -- If this socket is intended to receive messages, bind it |
| -- -- to a given socket address. |
| |
| -- Address.Addr := Any_Inet_Addr; |
| -- Address.Port := 55505; |
| |
| -- Bind_Socket (Socket, Address); |
| |
| -- -- If this socket is intended to send messages, provide the |
| -- -- receiver socket address. |
| |
| -- Address.Addr := Inet_Addr (Group); |
| -- Address.Port := 55506; |
| |
| -- Channel := Stream (Socket, Address); |
| |
| -- -- Receive and print message from client Ping |
| |
| -- declare |
| -- Message : String := String'Input (Channel); |
| |
| -- begin |
| -- -- Get the address of the sender |
| |
| -- Address := Get_Address (Channel); |
| -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); |
| |
| -- -- Send same message back to client Ping |
| |
| -- String'Output (Channel, Message); |
| -- end; |
| |
| -- Close_Socket (Socket); |
| |
| -- accept Stop; |
| |
| -- exception when E : others => |
| -- Ada.Text_IO.Put_Line |
| -- (Exception_Name (E) & ": " & Exception_Message (E)); |
| -- end Pong; |
| |
| -- task Ping is |
| -- entry Start; |
| -- entry Stop; |
| -- end Ping; |
| |
| -- task body Ping is |
| -- Address : Sock_Addr_Type; |
| -- Socket : Socket_Type; |
| -- Channel : Stream_Access; |
| |
| -- begin |
| -- accept Start; |
| |
| -- -- See comments in Ping section for the first steps |
| |
| -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); |
| -- Address.Port := 5876; |
| -- Create_Socket (Socket); |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- Socket_Level, |
| -- (Reuse_Address, True)); |
| |
| -- -- Force Pong to block |
| |
| -- delay 0.2; |
| |
| -- -- If the client's socket is not bound, Connect_Socket will |
| -- -- bind to an unused address. The client uses Connect_Socket to |
| -- -- create a logical connection between the client's socket and |
| -- -- a server's socket returned by Accept_Socket. |
| |
| -- Connect_Socket (Socket, Address); |
| |
| -- Channel := Stream (Socket); |
| |
| -- -- Send message to server Pong |
| |
| -- String'Output (Channel, "Hello world"); |
| |
| -- -- Force Ping to block |
| |
| -- delay 0.2; |
| |
| -- -- Receive and print message from server Pong |
| |
| -- Ada.Text_IO.Put_Line (String'Input (Channel)); |
| -- Close_Socket (Socket); |
| |
| -- -- Part of multicast example. Code similar to Pong's one |
| |
| -- Create_Socket (Socket, Family_Inet, Socket_Datagram); |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- Socket_Level, |
| -- (Reuse_Address, True)); |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Multicast_TTL, 1)); |
| |
| -- Set_Socket_Option |
| -- (Socket, |
| -- IP_Protocol_For_IP_Level, |
| -- (Multicast_Loop, True)); |
| |
| -- Address.Addr := Any_Inet_Addr; |
| -- Address.Port := 55506; |
| |
| -- Bind_Socket (Socket, Address); |
| |
| -- Address.Addr := Inet_Addr (Group); |
| -- Address.Port := 55505; |
| |
| -- Channel := Stream (Socket, Address); |
| |
| -- -- Send message to server Pong |
| |
| -- String'Output (Channel, "Hello world"); |
| |
| -- -- Receive and print message from server Pong |
| |
| -- declare |
| -- Message : String := String'Input (Channel); |
| |
| -- begin |
| -- Address := Get_Address (Channel); |
| -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); |
| -- end; |
| |
| -- Close_Socket (Socket); |
| |
| -- accept Stop; |
| |
| -- exception when E : others => |
| -- Ada.Text_IO.Put_Line |
| -- (Exception_Name (E) & ": " & Exception_Message (E)); |
| -- end Ping; |
| |
| -- begin |
| -- -- Indicate whether the thread library provides process |
| -- -- blocking IO. Basically, if you are not using FSU threads |
| -- -- the default is ok. |
| |
| -- Initialize (Process_Blocking_IO => False); |
| -- Ping.Start; |
| -- Pong.Start; |
| -- Ping.Stop; |
| -- Pong.Stop; |
| -- Finalize; |
| -- end PingPong; |
| |
| procedure Initialize (Process_Blocking_IO : Boolean := False); |
| -- Initialize must be called before using any other socket routines. The |
| -- Process_Blocking_IO parameter indicates whether the thread library |
| -- provides process-blocking or thread-blocking input/output operations. |
| -- In the former case (typically with FSU threads) GNAT.Sockets should be |
| -- initialized with a value of True to provide task-blocking IO through an |
| -- emulation mechanism. Only the first call to Initialize is taken into |
| -- account (further calls will be ignored). Note that with the default |
| -- value of Process_Blocking_IO, this operation is a no-op on UNIX |
| -- platforms, but applications should make sure to call it if portability |
| -- is expected: some platforms (such as Windows) require initialization |
| -- before any other socket operations. |
| |
| procedure Finalize; |
| -- After Finalize is called it is not possible to use any routines |
| -- exported in by this package. This procedure is idempotent. |
| |
| type Socket_Type is private; |
| -- Sockets are used to implement a reliable bi-directional point-to-point, |
| -- stream-based connections between hosts. No_Socket provides a special |
| -- value to denote uninitialized sockets. |
| |
| No_Socket : constant Socket_Type; |
| |
| Socket_Error : exception; |
| -- There is only one exception in this package to deal with an error during |
| -- a socket routine. Once raised, its message contains a string describing |
| -- the error code. |
| |
| function Image (Socket : Socket_Type) return String; |
| -- Return a printable string for Socket |
| |
| function To_C (Socket : Socket_Type) return Integer; |
| -- Return a file descriptor to be used by external subprograms. This is |
| -- useful for C functions that are not yet interfaced in this package. |
| |
| type Family_Type is (Family_Inet, Family_Inet6); |
| -- Address family (or protocol family) identifies the communication domain |
| -- and groups protocols with similar address formats. IPv6 will soon be |
| -- supported. |
| |
| type Mode_Type is (Socket_Stream, Socket_Datagram); |
| -- Stream sockets provide connection-oriented byte streams. Datagram |
| -- sockets support unreliable connectionless message based communication. |
| |
| type Shutmode_Type is (Shut_Read, Shut_Write, Shut_Read_Write); |
| -- When a process closes a socket, the policy is to retain any data queued |
| -- until either a delivery or a timeout expiration (in this case, the data |
| -- are discarded). A finer control is available through shutdown. With |
| -- Shut_Read, no more data can be received from the socket. With_Write, no |
| -- more data can be transmitted. Neither transmission nor reception can be |
| -- performed with Shut_Read_Write. |
| |
| type Port_Type is new Natural; |
| -- Classical port definition. No_Port provides a special value to |
| -- denote uninitialized port. Any_Port provides a special value |
| -- enabling all ports. |
| |
| Any_Port : constant Port_Type; |
| No_Port : constant Port_Type; |
| |
| type Inet_Addr_Type (Family : Family_Type := Family_Inet) is private; |
| -- An Internet address depends on an address family (IPv4 contains 4 |
| -- octets and Ipv6 contains 16 octets). Any_Inet_Addr is a special value |
| -- treated like a wildcard enabling all addresses. No_Inet_Addr provides a |
| -- special value to denote uninitialized inet addresses. |
| |
| Any_Inet_Addr : constant Inet_Addr_Type; |
| No_Inet_Addr : constant Inet_Addr_Type; |
| Broadcast_Inet_Addr : constant Inet_Addr_Type; |
| |
| type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record |
| Addr : Inet_Addr_Type (Family); |
| Port : Port_Type; |
| end record; |
| -- Socket addresses fully define a socket connection with protocol family, |
| -- an Internet address and a port. No_Sock_Addr provides a special value |
| -- for uninitialized socket addresses. |
| |
| No_Sock_Addr : constant Sock_Addr_Type; |
| |
| function Image (Value : Inet_Addr_Type) return String; |
| -- Return an image of an Internet address. IPv4 notation consists in 4 |
| -- octets in decimal format separated by dots. IPv6 notation consists in |
| -- 16 octets in hexadecimal format separated by colons (and possibly |
| -- dots). |
| |
| function Image (Value : Sock_Addr_Type) return String; |
| -- Return inet address image and port image separated by a colon |
| |
| function Inet_Addr (Image : String) return Inet_Addr_Type; |
| -- Convert address image from numbers-and-dots notation into an |
| -- inet address. |
| |
| -- Host entries provide complete information on a given host: the official |
| -- name, an array of alternative names or aliases and array of network |
| -- addresses. |
| |
| type Host_Entry_Type |
| (Aliases_Length, Addresses_Length : Natural) is private; |
| |
| function Official_Name (E : Host_Entry_Type) return String; |
| -- Return official name in host entry |
| |
| function Aliases_Length (E : Host_Entry_Type) return Natural; |
| -- Return number of aliases in host entry |
| |
| function Addresses_Length (E : Host_Entry_Type) return Natural; |
| -- Return number of addresses in host entry |
| |
| function Aliases |
| (E : Host_Entry_Type; |
| N : Positive := 1) return String; |
| -- Return N'th aliases in host entry. The first index is 1 |
| |
| function Addresses |
| (E : Host_Entry_Type; |
| N : Positive := 1) return Inet_Addr_Type; |
| -- Return N'th addresses in host entry. The first index is 1 |
| |
| Host_Error : exception; |
| -- Exception raised by the two following procedures. Once raised, its |
| -- message contains a string describing the error code. This exception is |
| -- raised when an host entry cannot be retrieved. |
| |
| function Get_Host_By_Address |
| (Address : Inet_Addr_Type; |
| Family : Family_Type := Family_Inet) return Host_Entry_Type; |
| -- Return host entry structure for the given Inet address. Note that no |
| -- result will be returned if there is no mapping of this IP address to a |
| -- host name in the system tables (host database, DNS or otherwise). |
| |
| function Get_Host_By_Name |
| (Name : String) return Host_Entry_Type; |
| -- Return host entry structure for the given host name. Here name is |
| -- either a host name, or an IP address. If Name is an IP address, this is |
| -- equivalent to Get_Host_By_Address (Inet_Addr (Name)). |
| |
| function Host_Name return String; |
| -- Return the name of the current host |
| |
| type Service_Entry_Type (Aliases_Length : Natural) is private; |
| -- Service entries provide complete information on a given service: the |
| -- official name, an array of alternative names or aliases and the port |
| -- number. |
| |
| function Official_Name (S : Service_Entry_Type) return String; |
| -- Return official name in service entry |
| |
| function Port_Number (S : Service_Entry_Type) return Port_Type; |
| -- Return port number in service entry |
| |
| function Protocol_Name (S : Service_Entry_Type) return String; |
| -- Return Protocol in service entry (usually UDP or TCP) |
| |
| function Aliases_Length (S : Service_Entry_Type) return Natural; |
| -- Return number of aliases in service entry |
| |
| function Aliases |
| (S : Service_Entry_Type; |
| N : Positive := 1) return String; |
| -- Return N'th aliases in service entry (the first index is 1) |
| |
| function Get_Service_By_Name |
| (Name : String; |
| Protocol : String) return Service_Entry_Type; |
| -- Return service entry structure for the given service name |
| |
| function Get_Service_By_Port |
| (Port : Port_Type; |
| Protocol : String) return Service_Entry_Type; |
| -- 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 |
| |
| 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; |
| W_Sig_Socket : Socket_Type; |
| 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; |
| |
| subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 .. 4); |
| 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); |
| |
| when Family_Inet6 => |
| Sin_V6 : Inet_Addr_V6_Type := (others => 0); |
| end case; |
| 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; |
