| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- G N A T . S O C K E T S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2001-2025, 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.Strings.Unbounded; |
| 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, |
| (if SOSC."=" (SOSC.Target_OS, SOSC.Windows) |
| then Duration (2 ** 32 / 1000) |
| else 1.0 * SOSC.MAX_tv_sec)); |
| -- Largest possible Duration that is also a valid value for the OS type |
| -- used for socket timeout. |
| |
| 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: |
| -- Completed: 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, Family_Unix, Family_Unspec); |
| -- Address family (or protocol family) identifies the communication domain |
| -- and groups protocols with similar address formats. |
| -- The order of the enumeration elements should not be changed unilaterally |
| -- because the IPv6_TCP_Preferred routine rely on it. |
| |
| subtype Family_Inet_4_6 is Family_Type range Family_Inet .. Family_Inet6; |
| |
| type Mode_Type is (Socket_Stream, Socket_Datagram, Socket_Raw); |
| -- Stream sockets provide connection-oriented byte streams. Datagram |
| -- sockets support unreliable connectionless message-based communication. |
| -- Raw sockets provide raw network-protocol access. |
| -- The order of the enumeration elements should not be changed unilaterally |
| -- because the IPv6_TCP_Preferred routine relies on it. |
| |
| 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). 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_Comp_Type is mod 2 ** 8; |
| -- Octet for Internet address |
| |
| Inet_Addr_Bytes_Length : constant array (Family_Inet_4_6) of Natural := |
| [Family_Inet => 4, Family_Inet6 => 16]; |
| |
| type Inet_Addr_Bytes is array (Natural range <>) of Inet_Addr_Comp_Type; |
| |
| subtype Inet_Addr_V4_Type is |
| Inet_Addr_Bytes (1 .. Inet_Addr_Bytes_Length (Family_Inet)); |
| subtype Inet_Addr_V6_Type is |
| Inet_Addr_Bytes (1 .. Inet_Addr_Bytes_Length (Family_Inet6)); |
| |
| subtype Inet_Addr_VN_Type is Inet_Addr_Bytes; |
| -- For backwards compatibility |
| |
| type Inet_Addr_Type (Family : Family_Inet_4_6 := 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; |
| |
| -- An Internet address depends on an address family (IPv4 contains 4 octets |
| -- and IPv6 contains 16 octets). |
| |
| Any_Inet_Addr : constant Inet_Addr_Type; |
| -- Wildcard enabling all addresses to use with bind |
| |
| Any_Inet6_Addr : constant Inet_Addr_Type; |
| -- Idem for IPV6 socket |
| |
| No_Inet_Addr : constant Inet_Addr_Type; |
| -- Uninitialized inet address |
| |
| Broadcast_Inet_Addr : constant Inet_Addr_Type; |
| -- Broadcast destination address in the current network |
| |
| Loopback_Inet_Addr : constant Inet_Addr_Type; |
| -- Loopback address to the local host |
| |
| Loopback_Inet6_Addr : constant Inet_Addr_Type; |
| -- IPv6 Loopback address to the local host |
| |
| -- Useful constants for multicast addresses |
| |
| Unspecified_Group_Inet_Addr : constant Inet_Addr_Type; |
| -- IPv4 multicast mask with prefix length 4 |
| |
| Unspecified_Group_Inet6_Addr : constant Inet_Addr_Type; |
| -- IPv6 multicast mask with prefix length 16 |
| |
| All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type; |
| -- Multicast group addresses all hosts on the same network segment |
| |
| All_Hosts_Group_Inet6_Addr : constant Inet_Addr_Type; |
| -- Idem for IPv6 protocol |
| |
| All_Routers_Group_Inet_Addr : constant Inet_Addr_Type; |
| -- Multicast group addresses all routers on the same network segment |
| |
| All_Routers_Group_Inet6_Addr : constant Inet_Addr_Type; |
| -- Idem for IPv6 protocol |
| |
| IPv4_To_IPv6_Prefix : constant Inet_Addr_Bytes := |
| [1 .. 10 => 0, 11 .. 12 => 255]; |
| -- Prefix for IPv4 mapped to IPv6 addresses |
| |
| -- Functions to handle masks and prefixes |
| |
| function Mask |
| (Family : Family_Inet_4_6; |
| Length : Natural; |
| Host : Boolean := False) return Inet_Addr_Type; |
| -- Return an address mask of the given family with the given prefix length. |
| -- If Host is False, this is a network mask (i.e. network bits are 1, |
| -- and host bits are 0); if Host is True, this is a host mask (i.e. |
| -- network bits are 0, and host bits are 1). |
| |
| function "and" (Addr, Mask : Inet_Addr_Type) return Inet_Addr_Type; |
| function "or" (Net, Host : Inet_Addr_Type) return Inet_Addr_Type; |
| function "not" (Mask : Inet_Addr_Type) return Inet_Addr_Type; |
| -- Bit-wise operations on inet addresses (both operands must have the |
| -- same address family). |
| |
| type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record |
| case Family is |
| when Family_Unix => |
| Name : Ada.Strings.Unbounded.Unbounded_String; |
| when Family_Inet_4_6 => |
| Addr : Inet_Addr_Type (Family); |
| Port : Port_Type; |
| when Family_Unspec => |
| null; |
| end case; |
| 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; |
| -- Uninitialized socket address |
| |
| function Is_IPv4_Address (Name : String) return Boolean; |
| -- Return true when Name is an IPv4 address in dotted quad notation |
| |
| function Is_IPv6_Address (Name : String) return Boolean; |
| -- Return true when Name is an IPv6 address in numeric format |
| |
| 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 |
| -- 8 hextets in hexadecimal format separated by colons. |
| |
| function Image (Value : Sock_Addr_Type) return String; |
| -- Return socket address image. Network socket address image will be with |
| -- a port image separated by a colon. |
| |
| function Inet_Addr (Image : String) return Inet_Addr_Type; |
| -- Convert address image from numbers-dots-and-colons notation into an |
| -- inet address. |
| |
| function Unix_Socket_Address (Addr : String) return Sock_Addr_Type; |
| -- Convert unix local socket name to Sock_Addr_Type |
| |
| function Network_Socket_Address |
| (Addr : Inet_Addr_Type; Port : Port_Type) return Sock_Addr_Type; |
| -- Create network socket 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_IPv6_Level, |
| IP_Protocol_For_UDP_Level, |
| IP_Protocol_For_TCP_Level, |
| IP_Protocol_For_ICMP_Level, |
| IP_Protocol_For_IGMP_Level, |
| IP_Protocol_For_RAW_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. Each socket option is |
| -- provided with an appropriate C name taken from the sockets API comments. |
| -- The C name can be used to find a detailed description in the OS-specific |
| -- documentation. The options are grouped by main Level_Type value, which |
| -- can be used together with this option in calls to the Set_Socket_Option |
| -- and Get_Socket_Option routines. Note that some options can be used with |
| -- more than one level. |
| |
| type Option_Name is |
| (Generic_Option, |
| -- Can be used to set/get any socket option via an OS-specific option |
| -- code with an integer value. |
| |
| ------------------ |
| -- Socket_Level -- |
| ------------------ |
| |
| Keep_Alive, -- SO_KEEPALIVE |
| -- Enable sending of keep-alive messages on connection-oriented sockets |
| |
| Reuse_Address, -- SO_REUSEADDR |
| -- Enable binding to an address and port already in use |
| |
| Broadcast, -- SO_BROADCAST |
| -- Enable sending broadcast datagrams on the socket |
| |
| Send_Buffer, -- SO_SNDBUF |
| -- Set/get the maximum socket send buffer in bytes |
| |
| Receive_Buffer, -- SO_RCVBUF |
| -- Set/get the maximum socket receive buffer in bytes |
| |
| Linger, -- SO_LINGER |
| -- When enabled, a Close_Socket or Shutdown_Socket will wait until all |
| -- queued messages for the socket have been successfully sent or the |
| -- linger timeout has been reached. |
| |
| Error, -- SO_ERROR |
| -- Get and clear the pending socket error integer code |
| |
| Send_Timeout, -- SO_SNDTIMEO |
| -- Specify sending timeout until reporting an error |
| |
| Receive_Timeout, -- SO_RCVTIMEO |
| -- Specify receiving timeout until reporting an error |
| |
| Busy_Polling, -- SO_BUSY_POLL |
| -- Sets the approximate time in microseconds to busy poll on a blocking |
| -- receive when there is no data. |
| |
| Bind_To_Device, -- SO_BINDTODEVICE |
| -- Bind to a specific NIC (Network Interface Controller) |
| |
| ------------------------------- |
| -- IP_Protocol_For_TCP_Level -- |
| ------------------------------- |
| |
| No_Delay, -- TCP_NODELAY |
| -- Disable the Nagle algorithm. This means that output buffer content |
| -- is always sent as soon as possible, even if there is only a small |
| -- amount of data. |
| |
| Keep_Alive_Count, -- TCP_KEEPCNT |
| -- Maximum number of keepalive probes |
| |
| Keep_Alive_Idle, -- TCP_KEEPIDLE |
| -- Idle time before TCP starts sending keepalive probes |
| |
| Keep_Alive_Interval, -- TCP_KEEPINTVL |
| -- Time between individual keepalive probes |
| |
| ------------------------------ |
| -- IP_Protocol_For_IP_Level -- |
| ------------------------------ |
| |
| Add_Membership_V4, -- IP_ADD_MEMBERSHIP |
| -- Join a multicast group |
| |
| Drop_Membership_V4, -- IP_DROP_MEMBERSHIP |
| -- Leave a multicast group |
| |
| Multicast_If_V4, -- IP_MULTICAST_IF |
| -- Set/Get outgoing interface for sending multicast packets |
| |
| Multicast_Loop_V4, -- IP_MULTICAST_LOOP |
| -- This boolean option determines whether sent multicast packets should |
| -- be looped back to the local sockets. |
| |
| Multicast_TTL, -- IP_MULTICAST_TTL |
| -- Set/Get the time-to-live of sent multicast packets |
| |
| Receive_Packet_Info, -- IP_PKTINFO |
| -- Receive low-level packet info as ancillary data |
| |
| -------------------------------- |
| -- IP_Protocol_For_IPv6_Level -- |
| -------------------------------- |
| |
| Add_Membership_V6, -- IPV6_ADD_MEMBERSHIP |
| -- Join IPv6 multicast group |
| |
| Drop_Membership_V6, -- IPV6_DROP_MEMBERSHIP |
| -- Leave IPv6 multicast group |
| |
| Multicast_If_V6, -- IPV6_MULTICAST_IF |
| -- Set/Get outgoing interface index for sending multicast packets |
| |
| Multicast_Loop_V6, -- IPV6_MULTICAST_LOOP |
| -- This boolean option determines whether sent multicast IPv6 packets |
| -- should be looped back to the local sockets. |
| |
| IPv6_Only, -- IPV6_V6ONLY |
| -- Restricted to IPv6 communications only |
| |
| Multicast_Hops -- IPV6_MULTICAST_HOPS |
| -- Set the multicast hop limit for the IPv6 socket |
| ); |
| |
| subtype Specific_Option_Name is |
| Option_Name range Keep_Alive .. Option_Name'Last; |
| |
| Add_Membership : Option_Name renames Add_Membership_V4; |
| Drop_Membership : Option_Name renames Drop_Membership_V4; |
| Multicast_If : Option_Name renames Multicast_If_V4; |
| Multicast_Loop : Option_Name renames Multicast_Loop_V4; |
| |
| 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 | |
| IPv6_Only | |
| Multicast_Loop_V4 | |
| Multicast_Loop_V6 => |
| Enabled : Boolean; |
| |
| case Name is |
| when Linger => |
| Seconds : Natural; |
| when others => |
| null; |
| end case; |
| |
| when Keep_Alive_Count => |
| Count : Natural; |
| |
| when Keep_Alive_Idle => |
| Idle_Seconds : Natural; |
| |
| when Keep_Alive_Interval => |
| Interval_Seconds : Natural; |
| |
| when Busy_Polling => |
| Microseconds : Natural; |
| |
| when Send_Buffer | |
| Receive_Buffer => |
| Size : Natural; |
| |
| when Error => |
| Error : Error_Type; |
| |
| when Add_Membership_V4 | |
| Add_Membership_V6 | |
| Drop_Membership_V4 | |
| Drop_Membership_V6 => |
| Multicast_Address : Inet_Addr_Type; |
| case Name is |
| when Add_Membership_V4 | |
| Drop_Membership_V4 => |
| Local_Interface : Inet_Addr_Type; |
| when others => |
| Interface_Index : Natural; |
| end case; |
| |
| when Multicast_If_V4 => |
| Outgoing_If : Inet_Addr_Type; |
| |
| when Multicast_If_V6 => |
| Outgoing_If_Index : Natural; |
| |
| when Multicast_TTL => |
| Time_To_Live : Natural; |
| |
| when Multicast_Hops => |
| Hop_Limit : Integer range -1 .. 255; |
| |
| when Send_Timeout | |
| Receive_Timeout => |
| Timeout : Timeval_Duration; |
| |
| when Bind_To_Device => |
| Device : Ada.Strings.Unbounded.Unbounded_String; |
| 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; |
| |
| type Address_Info is record |
| Addr : Sock_Addr_Type; |
| Mode : Mode_Type := Socket_Stream; |
| Level : Level_Type := IP_Protocol_For_IP_Level; |
| end record; |
| |
| type Address_Info_Array is array (Positive range <>) of Address_Info; |
| |
| function Get_Address_Info |
| (Host : String; |
| Service : String; |
| Family : Family_Type := Family_Unspec; |
| Mode : Mode_Type := Socket_Stream; |
| Level : Level_Type := IP_Protocol_For_IP_Level; |
| Numeric_Host : Boolean := False; |
| Passive : Boolean := False; |
| Unknown : access procedure |
| (Family, Mode, Level, Length : Integer) := null) |
| return Address_Info_Array; |
| -- Returns available addresses for the Host and Service names. |
| -- If Family is Family_Unspec, all available protocol families returned. |
| -- Service is the name of service as defined in /etc/services or port |
| -- number in string representation. |
| -- If Unknown procedure access specified it will be called in case of |
| -- unknown family found. |
| -- Numeric_Host flag suppresses any potentially lengthy network host |
| -- address lookups, and Host have to represent numerical network address in |
| -- this case. |
| -- If Passive is True and Host is empty then the returned socket addresses |
| -- will be suitable for binding a socket that will accept connections. |
| -- The returned socket address will contain the "wildcard address". |
| -- The wildcard address is used by applications (typically servers) that |
| -- intend to accept connections on any of the hosts's network addresses. |
| -- If Host is not empty, then the Passive flag is ignored. |
| -- If Passive is False, then the returned socket addresses will be suitable |
| -- for use with connect, sendto, or sendmsg. If Host is empty, then the |
| -- network address will be set to the loopback interface address; |
| -- this is used by applications that intend to communicate with peers |
| -- running on the same host. |
| |
| procedure Sort |
| (Addr_Info : in out Address_Info_Array; |
| Compare : access function (Left, Right : Address_Info) return Boolean); |
| -- Sort address info array in order defined by compare function |
| |
| function IPv6_TCP_Preferred (Left, Right : Address_Info) return Boolean; |
| -- To use with Sort to order where IPv6 and TCP addresses first |
| |
| type Host_Service (Host_Length, Service_Length : Natural) is record |
| Host : String (1 .. Host_Length); |
| Service : String (1 .. Service_Length); |
| end record; |
| |
| function Get_Name_Info |
| (Addr : Sock_Addr_Type; |
| Numeric_Host : Boolean := False; |
| Numeric_Serv : Boolean := False) return Host_Service; |
| -- Returns host and service names by the address and port. |
| -- If Numeric_Host is True, then the numeric form of the hostname is |
| -- returned. When Numeric_Host is False, this will still happen in case the |
| -- host name cannot be determined. |
| -- If Numenric_Serv is True, then the numeric form of the service address |
| -- (port number) is returned. When Numenric_Serv is False, this will still |
| -- happen in case the service's name cannot be determined. |
| |
| procedure Create_Socket |
| (Socket : out Socket_Type; |
| Family : Family_Type := Family_Inet; |
| Mode : Mode_Type := Socket_Stream; |
| Level : Level_Type := IP_Protocol_For_IP_Level); |
| -- Create an endpoint for communication. Raises Socket_Error on error |
| |
| procedure Create_Socket_Pair |
| (Left : out Socket_Type; |
| Right : out Socket_Type; |
| Family : Family_Type := Family_Unspec; |
| Mode : Mode_Type := Socket_Stream; |
| Level : Level_Type := IP_Protocol_For_IP_Level); |
| -- Create two connected sockets. Raises Socket_Error on error. |
| -- If Family is unspecified, it creates Family_Unix sockets on UNIX and |
| -- Family_Inet sockets on non UNIX platforms. |
| |
| 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; |
| 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; |
| 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 |
| |
| package ASU renames Ada.Strings.Unbounded; |
| |
| 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; |
| |
| Any_Port : constant Port_Type := 0; |
| No_Port : constant Port_Type := 0; |
| |
| Any_Inet_Addr : constant Inet_Addr_Type := |
| (Family_Inet, [others => 0]); |
| Any_Inet6_Addr : constant Inet_Addr_Type := |
| (Family_Inet6, [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]); |
| Loopback_Inet6_Addr : constant Inet_Addr_Type := |
| (Family_Inet6, |
| [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 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]); |
| |
| Unspecified_Group_Inet6_Addr : constant Inet_Addr_Type := |
| (Family_Inet6, [255, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]); |
| All_Hosts_Group_Inet6_Addr : constant Inet_Addr_Type := |
| (Family_Inet6, [255, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]); |
| All_Routers_Group_Inet6_Addr : constant Inet_Addr_Type := |
| (Family_Inet6, [255, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2]); |
| |
| No_Sock_Addr : constant Sock_Addr_Type := (Family_Inet, No_Inet_Addr, 0); |
| |
| Max_Name_Length : constant := SOSC.NI_MAXHOST; |
| -- Most systems don't provide constants that specify the maximum size |
| -- of either a FQDN or a service name. In order to aid applications in |
| -- allocating buffers, the constant NI_MAXHOST is defined in <netdb.h>. |
| |
| 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 (Positive range <>) of Name_Type; |
| type Inet_Addr_Array is array (Positive 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; |
| |
| procedure Raise_Socket_Error (Error : Integer) with No_Return; |
| -- Raise Socket_Error with an exception message describing the error code |
| -- from errno. |
| |
| end GNAT.Sockets; |
