Mercurial > hg > CbC > CbC_gcc
diff gcc/ada/libgnat/g-socket.ads @ 111:04ced10e8804
gcc 7
| author | kono |
|---|---|
| date | Fri, 27 Oct 2017 22:46:09 +0900 |
| parents | |
| children | 84e7813d76e9 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/ada/libgnat/g-socket.ads Fri Oct 27 22:46:09 2017 +0900 @@ -0,0 +1,1288 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- G N A T . S O C K E T S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2001-2017, 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 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- 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. + +-- 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 Interfaces.C; + +with System.OS_Constants; +with System.Storage_Elements; + +package GNAT.Sockets is + + -- Sockets are designed to provide a consistent communication facility + -- between applications. This package provides an Ada binding to the + -- de-facto standard BSD sockets API. The documentation below covers + -- only the specific binding provided by this package. It assumes that + -- the reader is already familiar with general network programming and + -- sockets usage. A useful reference on this matter is W. Richard Stevens' + -- "UNIX Network Programming: The Sockets Networking API" + -- (ISBN: 0131411551). + + -- 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). + + -- The example below demonstrates various features of GNAT.Sockets: + + -- 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 + -- -- 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 Start; + + -- 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)); + + -- -- 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); + + -- -- 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. + + -- 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 Ping 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, + -- (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); + + -- 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; + + -- 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 + -- Initialize; + -- Ping.Start; + -- Pong.Start; + -- Ping.Stop; + -- Pong.Stop; + -- Finalize; + -- end PingPong; + + package SOSC renames System.OS_Constants; + -- Renaming used to provide short-hand notations throughout the sockets + -- binding. Note that System.OS_Constants is an internal unit, and the + -- entities declared therein are not meant for direct access by users, + -- including through this renaming. + + use type Interfaces.C.int; + -- Need visibility on "-" operator so that we can write -1 + + procedure Initialize; + pragma Obsolescent + (Entity => Initialize, + Message => "explicit initialization is no longer required"); + -- Initialize must be called before using any other socket routines. + -- 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. + -- This is now a no-op (initialization and finalization are done + -- automatically). + + procedure Initialize (Process_Blocking_IO : Boolean); + pragma Obsolescent + (Entity => Initialize, + Message => "passing a parameter to Initialize is no longer supported"); + -- 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). + -- This is now a no-op (initialization and finalization are done + -- automatically). + + procedure Finalize; + pragma Obsolescent + (Entity => Finalize, + Message => "explicit finalization is no longer required"); + -- After Finalize is called it is not possible to use any routines + -- exported in by this package. This procedure is idempotent. + -- This is now a no-op (initialization and finalization are done + -- automatically). + + 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; + + type Selector_Type is limited private; + type Selector_Access is access all Selector_Type; + -- Selector objects are used to wait for i/o events to occur on sockets + + Null_Selector : constant Selector_Type; + -- The Null_Selector can be used in place of a normal selector without + -- having to call Create_Selector if the use of Abort_Selector is not + -- required. + + -- Timeval_Duration is a subtype of Standard.Duration because the full + -- range of Standard.Duration cannot be represented in the equivalent C + -- structure (struct timeval). Moreover, negative values are not allowed + -- to avoid system incompatibilities. + + Immediate : constant Duration := 0.0; + + Forever : constant Duration := + Duration'Min (Duration'Last, 1.0 * SOSC.MAX_tv_sec); + -- Largest possible Duration that is also a valid value for struct timeval + + subtype Timeval_Duration is Duration range Immediate .. Forever; + + subtype Selector_Duration is Timeval_Duration; + -- Timeout value for selector operations + + type Selector_Status is (Completed, Expired, Aborted); + -- Completion status of a selector operation, indicated as follows: + -- Complete: one of the expected events occurred + -- Expired: no event occurred before the expiration of the timeout + -- Aborted: an external action cancelled the wait operation before + -- any event occurred. + + 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_Ada (Fd : Integer) return Socket_Type with Inline; + -- Convert a file descriptor to Socket_Type. This is useful when a socket + -- file descriptor is obtained from an external library call. + + function To_C (Socket : Socket_Type) return Integer with Inline; + -- 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. + + 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 range 0 .. 16#ffff#; + -- TCP/UDP port number + + Any_Port : constant Port_Type; + -- All ports + + No_Port : constant Port_Type; + -- Uninitialized port number + + 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; + Loopback_Inet_Addr : constant Inet_Addr_Type; + + -- Useful constants for IPv4 multicast addresses + + Unspecified_Group_Inet_Addr : constant Inet_Addr_Type; + All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type; + All_Routers_Group_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; + pragma No_Component_Reordering (Sock_Addr_Type); + -- 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 + -- Note that on some platforms, a single error value is used for both + -- EWOULDBLOCK and EAGAIN. Both errors are therefore always reported as + -- Resource_Temporarily_Unavailable. + + 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, + Broken_Pipe, + Unknown_Host, + Host_Name_Lookup_Failure, + Non_Recoverable_Error, + 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. + + 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 + (Generic_Option, + 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 data (TCP_NODELAY) + Add_Membership, -- Join a multicast group + Drop_Membership, -- Leave a multicast group + Multicast_If, -- Set default out interface for multicast packets + Multicast_TTL, -- Set the time-to-live of sent multicast packets + Multicast_Loop, -- Sent multicast packets are looped to local socket + Receive_Packet_Info, -- Receive low level packet info as ancillary data + Send_Timeout, -- Set timeout value for output + Receive_Timeout, -- Set timeout value for input + Busy_Polling); -- Set busy polling mode + subtype Specific_Option_Name is + Option_Name range Keep_Alive .. Option_Name'Last; + + type Option_Type (Name : Option_Name := Keep_Alive) is record + case Name is + when Generic_Option => + Optname : Interfaces.C.int := -1; + Optval : Interfaces.C.int; + + when Keep_Alive | + Reuse_Address | + Broadcast | + Linger | + No_Delay | + Receive_Packet_Info | + Multicast_Loop => + Enabled : Boolean; + + case Name is + when Linger => + Seconds : Natural; + when others => + null; + end case; + + when Busy_Polling => + Microseconds : Natural; + + 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 specification of 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 : Interfaces.C.size_t; + 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. Note: if Server is a non-blocking socket, whether or not this + -- aspect is inherited by Socket is platform-dependent. + + procedure Accept_Socket + (Server : Socket_Type; + Socket : out Socket_Type; + Address : out Sock_Addr_Type; + Timeout : Selector_Duration; + Selector : access Selector_Type := null; + Status : out Selector_Status); + -- Accept a new connection on Server using Accept_Socket, waiting no longer + -- than the given timeout duration. Status is set to indicate whether the + -- operation completed successfully, timed out, or was aborted. If Selector + -- is not null, the designated selector is used to wait for the socket to + -- become available, else a private selector object is created by this + -- procedure and destroyed before it returns. + + 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 : Sock_Addr_Type); + -- Make a connection to another socket which has the address of Server. + -- Raises Socket_Error on error. + + procedure Connect_Socket + (Socket : Socket_Type; + Server : Sock_Addr_Type; + Timeout : Selector_Duration; + Selector : access Selector_Type := null; + Status : out Selector_Status); + -- Connect Socket to the given Server address using Connect_Socket, waiting + -- no longer than the given timeout duration. Status is set to indicate + -- whether the operation completed successfully, timed out, or was aborted. + -- If Selector is not null, the designated selector is used to wait for the + -- socket to become available, else a private selector object is created + -- by this procedure and destroyed before it returns. If Timeout is 0.0, + -- no attempt is made to detect whether the connection has succeeded; it + -- is up to the user to determine this using Check_Selector later on. + + 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 (e.g. socket closed or not locally bound). + + function Get_Socket_Option + (Socket : Socket_Type; + Level : Level_Type := Socket_Level; + Name : Option_Name; + Optname : Interfaces.C.int := -1) return Option_Type; + -- Get the options associated with a socket. Raises Socket_Error on error. + -- Optname identifies specific option when Name is Generic_Option. + + procedure Listen_Socket + (Socket : Socket_Type; + Length : Natural := 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. + -- The queue length of 15 is an example value that should be appropriate + -- in usual cases. It can be adjusted according to each application's + -- particular requirements. + + 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 in this case unless Item'First + -- is Stream_Element_Offset'First, in which case Constraint_Error is + -- raised. Flags allows control of 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 control of the reception. Raises Socket_Error on error. + + procedure Receive_Vector + (Socket : Socket_Type; + Vector : Vector_Type; + Count : out Ada.Streams.Stream_Element_Count; + Flags : Request_Flag_Type := No_Request_Flag); + -- 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. + -- Flags allow control over reception. + + 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; + To : access Sock_Addr_Type; + Flags : Request_Flag_Type := No_Request_Flag); + pragma Inline (Send_Socket); + -- Transmit a message over a socket. For a datagram socket, the address + -- is given by To.all. For a stream socket, To must be null. Last + -- is the index value such that Item (Last) is the last character + -- sent. Note that Last is set to Item'First - 1 if the socket has been + -- closed by the peer (unless Item'First is Stream_Element_Offset'First, + -- in which case Constraint_Error is raised instead). This is not an error, + -- and Socket_Error is not raised in that case. Flags allows control of the + -- transmission. Raises exception Socket_Error on error. Note: this + -- subprogram is inlined because it is also used to implement the two + -- variants below. + + 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 over a socket. Upon return, Last is set to the index + -- within Item of the last element transmitted. Flags allows control of + -- the transmission. Raises Socket_Error on any detected 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 over a datagram socket. The destination address is + -- To. Flags allows control of the transmission. Raises Socket_Error on + -- error. + + procedure Send_Vector + (Socket : Socket_Type; + Vector : Vector_Type; + Count : out Ada.Streams.Stream_Element_Count; + Flags : Request_Flag_Type := No_Request_Flag); + -- Transmit data gathered from the set of vector elements Vector to a + -- socket. Count is set to the count of transmitted stream elements. Flags + -- allow control over transmission. + + procedure Set_Close_On_Exec + (Socket : Socket_Type; + Close_On_Exec : Boolean; + Status : out Boolean); + -- When Close_On_Exec is True, mark Socket to be closed automatically when + -- a new program is executed by the calling process (i.e. prevent Socket + -- from being inherited by child processes). When Close_On_Exec is False, + -- mark Socket to not be closed on exec (i.e. allow it to be inherited). + -- Status is False if the operation could not be performed, or is not + -- supported on the target platform. + + 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 connected stream-based socket. + -- Note: keep in mind that the default stream attributes for composite + -- types perform separate Read/Write operations for each component, + -- recursively. If performance is an issue, you may want to consider + -- introducing a buffering stage. + + function Stream + (Socket : Socket_Type; + Send_To : Sock_Addr_Type) return Stream_Access; + -- Create a stream associated with an already bound datagram-based socket. + -- Send_To is the destination address to which messages are being sent. + + function Get_Address + (Stream : not null 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 manipulation of sets of sockets. It allows waiting + -- for events on multiple endpoints at one time. This type has default + -- initialization, and the default value is the empty set. + -- + -- Note: This type used to contain a pointer to dynamically allocated + -- storage, but this is not the case anymore, and no special precautions + -- are required to avoid memory leaks. + + procedure Clear (Item : in out Socket_Set_Type; Socket : Socket_Type); + -- Remove Socket from Item + + procedure Copy (Source : Socket_Set_Type; Target : out Socket_Set_Type); + -- Copy Source into Target as Socket_Set_Type is limited private + + procedure Empty (Item : out Socket_Set_Type); + -- Remove all Sockets from Item + + 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 + + function Image (Item : Socket_Set_Type) return String; + -- Return a printable image of Item, for debugging purposes + + -- 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 behavior. 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 behavior he wants. Abort_Selector allows the safe + -- abort of a blocked Check_Selector call. A special socket 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. Note that each call to Abort_Selector will cause + -- exactly one call to Check_Selector to return with Aborted status. The + -- special socket created by Create_Selector is closed when Close_Selector + -- is called. + -- + -- A typical case where it is useful to abort a Check_Selector operation is + -- the situation where a change to the monitored sockets set must be made. + + procedure Create_Selector (Selector : out Selector_Type); + -- Initialize (open) 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). Has no effect if Selector is + -- already closed. + + procedure Check_Selector + (Selector : 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. + -- + -- 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. Also keep in mind that this + -- procedure modifies the passed socket sets to indicate which sockets + -- actually had events upon return. The socket set therefore has to + -- be reset by the caller for further calls. + -- + -- 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 : 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 watching for exception + -- events (i.e. 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. The Selector may not be the + -- Null_Selector. + + type Fd_Set is private; + -- ??? This type must not be used directly, it needs to be visible because + -- it is used in the visible part of GNAT.Sockets.Thin_Common. This is + -- really an inversion of abstraction. The private part of GNAT.Sockets + -- needs to have visibility on this type, but since Thin_Common is a child + -- of Sockets, the type can't be declared there. The correct fix would + -- be to move the thin sockets binding outside of GNAT.Sockets altogether, + -- e.g. by renaming it to GNAT.Sockets_Thin. + +private + + type Socket_Type is new Integer; + No_Socket : constant Socket_Type := -1; + + -- A selector is either a null selector, which is always "open" and can + -- never be aborted, or a regular selector, which is created "closed", + -- becomes "open" when Create_Selector is called, and "closed" again when + -- Close_Selector is called. + + type Selector_Type (Is_Null : Boolean := False) is limited record + case Is_Null is + when True => + null; + + when False => + R_Sig_Socket : Socket_Type := No_Socket; + W_Sig_Socket : Socket_Type := No_Socket; + -- Signalling sockets used to abort a select operation + end case; + end record; + + pragma Volatile (Selector_Type); + + Null_Selector : constant Selector_Type := (Is_Null => True); + + type Fd_Set is + new System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_fd_set); + for Fd_Set'Alignment use Interfaces.C.long'Alignment; + -- Set conservative alignment so that our Fd_Sets are always adequately + -- aligned for the underlying data type (which is implementation defined + -- and may be an array of C long integers). + + type Fd_Set_Access is access all Fd_Set; + pragma Convention (C, Fd_Set_Access); + No_Fd_Set_Access : constant Fd_Set_Access := null; + + type Socket_Set_Type is record + Last : Socket_Type := No_Socket; + -- Highest socket in set. Last = No_Socket denotes an empty set (which + -- is the default initial value). + + Set : aliased Fd_Set; + -- Underlying socket set. Note that the contents of this component is + -- undefined if Last = No_Socket. + 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)); + Loopback_Inet_Addr : constant Inet_Addr_Type := + (Family_Inet, (127, 0, 0, 1)); + + Unspecified_Group_Inet_Addr : constant Inet_Addr_Type := + (Family_Inet, (224, 0, 0, 0)); + All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type := + (Family_Inet, (224, 0, 0, 1)); + All_Routers_Group_Inet_Addr : constant Inet_Addr_Type := + (Family_Inet, (224, 0, 0, 2)); + + 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; + Port : Port_Type; + Protocol : Name_Type; + Aliases : Name_Array (1 .. Aliases_Length); + 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;