-- --
-- S p e c --
-- --
--- Copyright (C) 2001-2003 Ada Core Technologies, Inc. --
+-- Copyright (C) 2001-2007, 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- --
-- 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, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- 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 package provides an interface to the sockets communication
--- facility provided on many operating systems. This is implemented
--- on the following platforms:
+-- 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, except Interix, with restrictions as follows
+-- 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.
+-- 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.
+-- The VMS implementation was implemented using the DECC RTL Socket API,
+-- and is thus subject to limitations in the implementation of this API.
--- This package is not supported on the Interix port of GNAT.
+-- VxWorks cross ports fully implement this package
--- VxWorks cross ports fully implement this package.
-
--- This package is not yet implemented on LynxOS.
+-- This package is not yet implemented on LynxOS or other cross ports
with Ada.Exceptions;
with Ada.Streams;
+with Ada.Unchecked_Deallocation;
with System;
-- 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.
+ -- 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 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 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).
+ -- 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:
-- 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.
+ -- -- 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);
-- 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
-- Bind_Socket (Socket, Address);
+ -- -- Join a multicast group
+
+ -- -- Portability note: On Windows, this option may be set only
+ -- -- on a bound socket.
+
+ -- Set_Socket_Option
+ -- (Socket,
+ -- IP_Protocol_For_IP_Level,
+ -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr));
+
-- -- If this socket is intended to send messages, provide the
-- -- receiver socket address.
-- Channel := Stream (Socket);
- -- -- Send message to server Pong.
+ -- -- Send message to server Pong
-- String'Output (Channel, "Hello world");
-- 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
-- Bind_Socket (Socket, Address);
+ -- Set_Socket_Option
+ -- (Socket,
+ -- IP_Protocol_For_IP_Level,
+ -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr));
+
-- Address.Addr := Inet_Addr (Group);
-- Address.Port := 55505;
-- 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);
+ -- Initialize;
-- Ping.Start;
-- Pong.Start;
-- Ping.Stop;
-- Finalize;
-- end PingPong;
- procedure Initialize (Process_Blocking_IO : Boolean := False);
+ procedure Initialize;
-- 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.
+ -- Note that 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 socket operation.
+
+ procedure Initialize (Process_Blocking_IO : Boolean);
+ pragma Obsolescent
+ (Entity => Initialize,
+ "passing a parameter to Initialize is not supported anymore");
+ -- Previous versions of GNAT.Sockets used to require the user to indicate
+ -- whether socket I/O was process- or thread-blocking on the platform.
+ -- This property is now determined automatically when the run-time library
+ -- is built. The old version of Initialize, taking a parameter, is kept
+ -- for compatibility reasons, but this interface is obsolete (and if the
+ -- value given is wrong, an exception will be raised at run time).
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.
+ -- 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.
+ -- 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
- -- especially the C functions that are not yet interfaced in this
- -- package.
+ -- 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.
+ -- 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.
+ -- 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
+ -- 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;
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_Address is a
- -- special value treated like a wildcard enabling all addresses.
- -- No_Inet_Addr provides a special value to denote uninitialized
- -- inet addresses.
+ -- 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;
+ 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 a
- -- protocol family, an Internet address and a port. No_Sock_Addr
- -- provides a special value for uninitialized socket addresses.
+ -- 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).
+ -- 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.
+ -- 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.
+ -- 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;
-- 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.
+ (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.
+ (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 can not be retrieved.
+ -- 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
+ 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.
+ (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
- -- Service entries provide complete information on a given
- -- service: the official name, an array of alternative names or
- -- aliases and the port number.
-
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
-- 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.
+ (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;
+ 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;
+ 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.
+ -- 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.
+ -- The name of the enumeration constant documents the error condition
type Error_Type is
(Success,
Unknown_Server_Error,
Cannot_Resolve_Error);
- -- 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.
+ -- 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_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.
+ -- 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 broadcast packets
- 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_TTL, -- Indicate the time-to-live of sent multicast packets
- Multicast_Loop); -- Sent multicast packets are looped to the local socket
+ 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 Add_Membership |
Drop_Membership =>
- Multiaddr : Inet_Addr_Type;
- Interface : Inet_Addr_Type;
+ 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.
+ -- 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.
end case;
end record;
- -- A request flag allows to specify the type of message
- -- transmissions or receptions. A request flag can be a
- -- combination of zero or more predefined request flags.
+ -- 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.
+ -- 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.
+ -- 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.
+ -- 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 dif-
- -- ferent type than that returned.
+ -- 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.
+ -- 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
(Socket : out Socket_Type;
Family : Family_Type := Family_Inet;
Mode : Mode_Type := Socket_Stream);
- -- Create an endpoint for communication. Raises Socket_Error on error.
+ -- 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);
- -- Extract 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.
+ -- 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;
-- Socket_Error on error.
procedure Close_Socket (Socket : Socket_Type);
- -- Close a socket and more specifically a non-connected socket.
+ -- Close a socket and more specifically a non-connected socket
procedure Connect_Socket
(Socket : Socket_Type;
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.
+ -- 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
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).
+ -- 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;
+ 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.
+ -- 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.
+ -- 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;
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.
+ -- 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;
-- 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.
+ (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;
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.
+ -- 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;
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.
+ -- 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;
(Socket : Socket_Type;
Level : Level_Type := Socket_Level;
Option : Option_Type);
- -- Manipulate socket options. Raises Socket_Error on error.
+ -- 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.
+ -- 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;
+ 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 (Stream : in out Stream_Access);
- -- Destroy a stream created by one of the Stream functions above, and
- -- release associated resources. The user is responsible for calling
- -- this subprogram when the stream is not needed anymore.
+ 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.
+ -- 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
-- 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 if Item 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 if Socket is present in Item
+ Socket : Socket_Type) return Boolean;
+ -- Return True iff Socket is present in Item
- procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type);
+ procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type);
-- Insert Socket into Item
- -- C select() waits for a number of file descriptors to change
- -- status. 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,
- -- C select can block the full process.
+ -- 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 in 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.
+ -- 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;
- -- Selector_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 Selector_Duration is Duration range Immediate .. Forever;
+ 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
+ -- 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);
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 receive 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 objects must be passed
- -- as R_Socket_Set and W_Socket_Set (even if they contain the same
- -- set of Sockets), or some event will be lost.
+ -- 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.
+ -- 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;
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.
+ -- 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.
+ -- Send an abort signal to the selector
private
No_Socket : constant Socket_Type := -1;
type Selector_Type is limited record
- R_Sig_Socket : Socket_Type;
- W_Sig_Socket : Socket_Type;
+ 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.
+ -- 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;
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));
+ 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);
+ 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
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