1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- G N A T . S O C K E T S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2001-2014, AdaCore -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package provides an interface to the sockets communication facility 33-- provided on many operating systems. This is implemented on the following 34-- platforms: 35 36-- All native ports, with restrictions as follows 37 38-- Multicast is available only on systems which provide support for this 39-- feature, so it is not available if Multicast is not supported, or not 40-- installed. 41 42-- VxWorks cross ports fully implement this package 43 44-- This package is not yet implemented on LynxOS or other cross ports 45 46with Ada.Exceptions; 47with Ada.Streams; 48with Ada.Unchecked_Deallocation; 49 50with Interfaces.C; 51 52with System.OS_Constants; 53with System.Storage_Elements; 54 55package GNAT.Sockets is 56 57 -- Sockets are designed to provide a consistent communication facility 58 -- between applications. This package provides an Ada binding to the 59 -- de-facto standard BSD sockets API. The documentation below covers 60 -- only the specific binding provided by this package. It assumes that 61 -- the reader is already familiar with general network programming and 62 -- sockets usage. A useful reference on this matter is W. Richard Stevens' 63 -- "UNIX Network Programming: The Sockets Networking API" 64 -- (ISBN: 0131411551). 65 66 -- GNAT.Sockets has been designed with several ideas in mind 67 68 -- This is a system independent interface. Therefore, we try as much as 69 -- possible to mask system incompatibilities. Some functionalities are not 70 -- available because there are not fully supported on some systems. 71 72 -- This is a thick binding. For instance, a major effort has been done to 73 -- avoid using memory addresses or untyped ints. We preferred to define 74 -- streams and enumeration types. Errors are not returned as returned 75 -- values but as exceptions. 76 77 -- This package provides a POSIX-compliant interface (between two 78 -- different implementations of the same routine, we adopt the one closest 79 -- to the POSIX specification). For instance, using select(), the 80 -- notification of an asynchronous connect failure is delivered in the 81 -- write socket set (POSIX) instead of the exception socket set (NT). 82 83 -- The example below demonstrates various features of GNAT.Sockets: 84 85 -- with GNAT.Sockets; use GNAT.Sockets; 86 87 -- with Ada.Text_IO; 88 -- with Ada.Exceptions; use Ada.Exceptions; 89 90 -- procedure PingPong is 91 92 -- Group : constant String := "239.255.128.128"; 93 -- -- Multicast group: administratively scoped IP address 94 95 -- task Pong is 96 -- entry Start; 97 -- entry Stop; 98 -- end Pong; 99 100 -- task body Pong is 101 -- Address : Sock_Addr_Type; 102 -- Server : Socket_Type; 103 -- Socket : Socket_Type; 104 -- Channel : Stream_Access; 105 106 -- begin 107 -- -- Get an Internet address of a host (here the local host name). 108 -- -- Note that a host can have several addresses. Here we get 109 -- -- the first one which is supposed to be the official one. 110 111 -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); 112 113 -- -- Get a socket address that is an Internet address and a port 114 115 -- Address.Port := 5876; 116 117 -- -- The first step is to create a socket. Once created, this 118 -- -- socket must be associated to with an address. Usually only a 119 -- -- server (Pong here) needs to bind an address explicitly. Most 120 -- -- of the time clients can skip this step because the socket 121 -- -- routines will bind an arbitrary address to an unbound socket. 122 123 -- Create_Socket (Server); 124 125 -- -- Allow reuse of local addresses 126 127 -- Set_Socket_Option 128 -- (Server, 129 -- Socket_Level, 130 -- (Reuse_Address, True)); 131 132 -- Bind_Socket (Server, Address); 133 134 -- -- A server marks a socket as willing to receive connect events 135 136 -- Listen_Socket (Server); 137 138 -- -- Once a server calls Listen_Socket, incoming connects events 139 -- -- can be accepted. The returned Socket is a new socket that 140 -- -- represents the server side of the connection. Server remains 141 -- -- available to receive further connections. 142 143 -- accept Start; 144 145 -- Accept_Socket (Server, Socket, Address); 146 147 -- -- Return a stream associated to the connected socket 148 149 -- Channel := Stream (Socket); 150 151 -- -- Force Pong to block 152 153 -- delay 0.2; 154 155 -- -- Receive and print message from client Ping 156 157 -- declare 158 -- Message : String := String'Input (Channel); 159 160 -- begin 161 -- Ada.Text_IO.Put_Line (Message); 162 163 -- -- Send same message back to client Ping 164 165 -- String'Output (Channel, Message); 166 -- end; 167 168 -- Close_Socket (Server); 169 -- Close_Socket (Socket); 170 171 -- -- Part of the multicast example 172 173 -- -- Create a datagram socket to send connectionless, unreliable 174 -- -- messages of a fixed maximum length. 175 176 -- Create_Socket (Socket, Family_Inet, Socket_Datagram); 177 178 -- -- Allow reuse of local addresses 179 180 -- Set_Socket_Option 181 -- (Socket, 182 -- Socket_Level, 183 -- (Reuse_Address, True)); 184 185 -- -- Controls the live time of the datagram to avoid it being 186 -- -- looped forever due to routing errors. Routers decrement 187 -- -- the TTL of every datagram as it traverses from one network 188 -- -- to another and when its value reaches 0 the packet is 189 -- -- dropped. Default is 1. 190 191 -- Set_Socket_Option 192 -- (Socket, 193 -- IP_Protocol_For_IP_Level, 194 -- (Multicast_TTL, 1)); 195 196 -- -- Want the data you send to be looped back to your host 197 198 -- Set_Socket_Option 199 -- (Socket, 200 -- IP_Protocol_For_IP_Level, 201 -- (Multicast_Loop, True)); 202 203 -- -- If this socket is intended to receive messages, bind it 204 -- -- to a given socket address. 205 206 -- Address.Addr := Any_Inet_Addr; 207 -- Address.Port := 55505; 208 209 -- Bind_Socket (Socket, Address); 210 211 -- -- Join a multicast group 212 213 -- -- Portability note: On Windows, this option may be set only 214 -- -- on a bound socket. 215 216 -- Set_Socket_Option 217 -- (Socket, 218 -- IP_Protocol_For_IP_Level, 219 -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); 220 221 -- -- If this socket is intended to send messages, provide the 222 -- -- receiver socket address. 223 224 -- Address.Addr := Inet_Addr (Group); 225 -- Address.Port := 55506; 226 227 -- Channel := Stream (Socket, Address); 228 229 -- -- Receive and print message from client Ping 230 231 -- declare 232 -- Message : String := String'Input (Channel); 233 234 -- begin 235 -- -- Get the address of the sender 236 237 -- Address := Get_Address (Channel); 238 -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); 239 240 -- -- Send same message back to client Ping 241 242 -- String'Output (Channel, Message); 243 -- end; 244 245 -- Close_Socket (Socket); 246 247 -- accept Stop; 248 249 -- exception when E : others => 250 -- Ada.Text_IO.Put_Line 251 -- (Exception_Name (E) & ": " & Exception_Message (E)); 252 -- end Pong; 253 254 -- task Ping is 255 -- entry Start; 256 -- entry Stop; 257 -- end Ping; 258 259 -- task body Ping is 260 -- Address : Sock_Addr_Type; 261 -- Socket : Socket_Type; 262 -- Channel : Stream_Access; 263 264 -- begin 265 -- accept Start; 266 267 -- -- See comments in Ping section for the first steps 268 269 -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); 270 -- Address.Port := 5876; 271 -- Create_Socket (Socket); 272 273 -- Set_Socket_Option 274 -- (Socket, 275 -- Socket_Level, 276 -- (Reuse_Address, True)); 277 278 -- -- Force Ping to block 279 280 -- delay 0.2; 281 282 -- -- If the client's socket is not bound, Connect_Socket will 283 -- -- bind to an unused address. The client uses Connect_Socket to 284 -- -- create a logical connection between the client's socket and 285 -- -- a server's socket returned by Accept_Socket. 286 287 -- Connect_Socket (Socket, Address); 288 289 -- Channel := Stream (Socket); 290 291 -- -- Send message to server Pong 292 293 -- String'Output (Channel, "Hello world"); 294 295 -- -- Force Ping to block 296 297 -- delay 0.2; 298 299 -- -- Receive and print message from server Pong 300 301 -- Ada.Text_IO.Put_Line (String'Input (Channel)); 302 -- Close_Socket (Socket); 303 304 -- -- Part of multicast example. Code similar to Pong's one 305 306 -- Create_Socket (Socket, Family_Inet, Socket_Datagram); 307 308 -- Set_Socket_Option 309 -- (Socket, 310 -- Socket_Level, 311 -- (Reuse_Address, True)); 312 313 -- Set_Socket_Option 314 -- (Socket, 315 -- IP_Protocol_For_IP_Level, 316 -- (Multicast_TTL, 1)); 317 318 -- Set_Socket_Option 319 -- (Socket, 320 -- IP_Protocol_For_IP_Level, 321 -- (Multicast_Loop, True)); 322 323 -- Address.Addr := Any_Inet_Addr; 324 -- Address.Port := 55506; 325 326 -- Bind_Socket (Socket, Address); 327 328 -- Set_Socket_Option 329 -- (Socket, 330 -- IP_Protocol_For_IP_Level, 331 -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); 332 333 -- Address.Addr := Inet_Addr (Group); 334 -- Address.Port := 55505; 335 336 -- Channel := Stream (Socket, Address); 337 338 -- -- Send message to server Pong 339 340 -- String'Output (Channel, "Hello world"); 341 342 -- -- Receive and print message from server Pong 343 344 -- declare 345 -- Message : String := String'Input (Channel); 346 347 -- begin 348 -- Address := Get_Address (Channel); 349 -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); 350 -- end; 351 352 -- Close_Socket (Socket); 353 354 -- accept Stop; 355 356 -- exception when E : others => 357 -- Ada.Text_IO.Put_Line 358 -- (Exception_Name (E) & ": " & Exception_Message (E)); 359 -- end Ping; 360 361 -- begin 362 -- Initialize; 363 -- Ping.Start; 364 -- Pong.Start; 365 -- Ping.Stop; 366 -- Pong.Stop; 367 -- Finalize; 368 -- end PingPong; 369 370 package SOSC renames System.OS_Constants; 371 -- Renaming used to provide short-hand notations throughout the sockets 372 -- binding. Note that System.OS_Constants is an internal unit, and the 373 -- entities declared therein are not meant for direct access by users, 374 -- including through this renaming. 375 376 procedure Initialize; 377 pragma Obsolescent 378 (Entity => Initialize, 379 Message => "explicit initialization is no longer required"); 380 -- Initialize must be called before using any other socket routines. 381 -- Note that this operation is a no-op on UNIX platforms, but applications 382 -- should make sure to call it if portability is expected: some platforms 383 -- (such as Windows) require initialization before any socket operation. 384 -- This is now a no-op (initialization and finalization are done 385 -- automatically). 386 387 procedure Initialize (Process_Blocking_IO : Boolean); 388 pragma Obsolescent 389 (Entity => Initialize, 390 Message => "passing a parameter to Initialize is no longer supported"); 391 -- Previous versions of GNAT.Sockets used to require the user to indicate 392 -- whether socket I/O was process- or thread-blocking on the platform. 393 -- This property is now determined automatically when the run-time library 394 -- is built. The old version of Initialize, taking a parameter, is kept 395 -- for compatibility reasons, but this interface is obsolete (and if the 396 -- value given is wrong, an exception will be raised at run time). 397 -- This is now a no-op (initialization and finalization are done 398 -- automatically). 399 400 procedure Finalize; 401 pragma Obsolescent 402 (Entity => Finalize, 403 Message => "explicit finalization is no longer required"); 404 -- After Finalize is called it is not possible to use any routines 405 -- exported in by this package. This procedure is idempotent. 406 -- This is now a no-op (initialization and finalization are done 407 -- automatically). 408 409 type Socket_Type is private; 410 -- Sockets are used to implement a reliable bi-directional point-to-point, 411 -- stream-based connections between hosts. No_Socket provides a special 412 -- value to denote uninitialized sockets. 413 414 No_Socket : constant Socket_Type; 415 416 type Selector_Type is limited private; 417 type Selector_Access is access all Selector_Type; 418 -- Selector objects are used to wait for i/o events to occur on sockets 419 420 Null_Selector : constant Selector_Type; 421 -- The Null_Selector can be used in place of a normal selector without 422 -- having to call Create_Selector if the use of Abort_Selector is not 423 -- required. 424 425 -- Timeval_Duration is a subtype of Standard.Duration because the full 426 -- range of Standard.Duration cannot be represented in the equivalent C 427 -- structure (struct timeval). Moreover, negative values are not allowed 428 -- to avoid system incompatibilities. 429 430 Immediate : constant Duration := 0.0; 431 432 Forever : constant Duration := 433 Duration'Min (Duration'Last, 1.0 * SOSC.MAX_tv_sec); 434 -- Largest possible Duration that is also a valid value for struct timeval 435 436 subtype Timeval_Duration is Duration range Immediate .. Forever; 437 438 subtype Selector_Duration is Timeval_Duration; 439 -- Timeout value for selector operations 440 441 type Selector_Status is (Completed, Expired, Aborted); 442 -- Completion status of a selector operation, indicated as follows: 443 -- Complete: one of the expected events occurred 444 -- Expired: no event occurred before the expiration of the timeout 445 -- Aborted: an external action cancelled the wait operation before 446 -- any event occurred. 447 448 Socket_Error : exception; 449 -- There is only one exception in this package to deal with an error during 450 -- a socket routine. Once raised, its message contains a string describing 451 -- the error code. 452 453 function Image (Socket : Socket_Type) return String; 454 -- Return a printable string for Socket 455 456 function To_C (Socket : Socket_Type) return Integer; 457 -- Return a file descriptor to be used by external subprograms. This is 458 -- useful for C functions that are not yet interfaced in this package. 459 460 type Family_Type is (Family_Inet, Family_Inet6); 461 -- Address family (or protocol family) identifies the communication domain 462 -- and groups protocols with similar address formats. 463 464 type Mode_Type is (Socket_Stream, Socket_Datagram); 465 -- Stream sockets provide connection-oriented byte streams. Datagram 466 -- sockets support unreliable connectionless message based communication. 467 468 type Shutmode_Type is (Shut_Read, Shut_Write, Shut_Read_Write); 469 -- When a process closes a socket, the policy is to retain any data queued 470 -- until either a delivery or a timeout expiration (in this case, the data 471 -- are discarded). A finer control is available through shutdown. With 472 -- Shut_Read, no more data can be received from the socket. With_Write, no 473 -- more data can be transmitted. Neither transmission nor reception can be 474 -- performed with Shut_Read_Write. 475 476 type Port_Type is range 0 .. 16#ffff#; 477 -- TCP/UDP port number 478 479 Any_Port : constant Port_Type; 480 -- All ports 481 482 No_Port : constant Port_Type; 483 -- Uninitialized port number 484 485 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is private; 486 -- An Internet address depends on an address family (IPv4 contains 4 octets 487 -- and IPv6 contains 16 octets). Any_Inet_Addr is a special value treated 488 -- like a wildcard enabling all addresses. No_Inet_Addr provides a special 489 -- value to denote uninitialized inet addresses. 490 491 Any_Inet_Addr : constant Inet_Addr_Type; 492 No_Inet_Addr : constant Inet_Addr_Type; 493 Broadcast_Inet_Addr : constant Inet_Addr_Type; 494 Loopback_Inet_Addr : constant Inet_Addr_Type; 495 496 -- Useful constants for IPv4 multicast addresses 497 498 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type; 499 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type; 500 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type; 501 502 type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record 503 Addr : Inet_Addr_Type (Family); 504 Port : Port_Type; 505 end record; 506 -- Socket addresses fully define a socket connection with protocol family, 507 -- an Internet address and a port. No_Sock_Addr provides a special value 508 -- for uninitialized socket addresses. 509 510 No_Sock_Addr : constant Sock_Addr_Type; 511 512 function Image (Value : Inet_Addr_Type) return String; 513 -- Return an image of an Internet address. IPv4 notation consists in 4 514 -- octets in decimal format separated by dots. IPv6 notation consists in 515 -- 16 octets in hexadecimal format separated by colons (and possibly 516 -- dots). 517 518 function Image (Value : Sock_Addr_Type) return String; 519 -- Return inet address image and port image separated by a colon 520 521 function Inet_Addr (Image : String) return Inet_Addr_Type; 522 -- Convert address image from numbers-and-dots notation into an 523 -- inet address. 524 525 -- Host entries provide complete information on a given host: the official 526 -- name, an array of alternative names or aliases and array of network 527 -- addresses. 528 529 type Host_Entry_Type 530 (Aliases_Length, Addresses_Length : Natural) is private; 531 532 function Official_Name (E : Host_Entry_Type) return String; 533 -- Return official name in host entry 534 535 function Aliases_Length (E : Host_Entry_Type) return Natural; 536 -- Return number of aliases in host entry 537 538 function Addresses_Length (E : Host_Entry_Type) return Natural; 539 -- Return number of addresses in host entry 540 541 function Aliases 542 (E : Host_Entry_Type; 543 N : Positive := 1) return String; 544 -- Return N'th aliases in host entry. The first index is 1 545 546 function Addresses 547 (E : Host_Entry_Type; 548 N : Positive := 1) return Inet_Addr_Type; 549 -- Return N'th addresses in host entry. The first index is 1 550 551 Host_Error : exception; 552 -- Exception raised by the two following procedures. Once raised, its 553 -- message contains a string describing the error code. This exception is 554 -- raised when an host entry cannot be retrieved. 555 556 function Get_Host_By_Address 557 (Address : Inet_Addr_Type; 558 Family : Family_Type := Family_Inet) return Host_Entry_Type; 559 -- Return host entry structure for the given Inet address. Note that no 560 -- result will be returned if there is no mapping of this IP address to a 561 -- host name in the system tables (host database, DNS or otherwise). 562 563 function Get_Host_By_Name 564 (Name : String) return Host_Entry_Type; 565 -- Return host entry structure for the given host name. Here name is 566 -- either a host name, or an IP address. If Name is an IP address, this 567 -- is equivalent to Get_Host_By_Address (Inet_Addr (Name)). 568 569 function Host_Name return String; 570 -- Return the name of the current host 571 572 type Service_Entry_Type (Aliases_Length : Natural) is private; 573 -- Service entries provide complete information on a given service: the 574 -- official name, an array of alternative names or aliases and the port 575 -- number. 576 577 function Official_Name (S : Service_Entry_Type) return String; 578 -- Return official name in service entry 579 580 function Port_Number (S : Service_Entry_Type) return Port_Type; 581 -- Return port number in service entry 582 583 function Protocol_Name (S : Service_Entry_Type) return String; 584 -- Return Protocol in service entry (usually UDP or TCP) 585 586 function Aliases_Length (S : Service_Entry_Type) return Natural; 587 -- Return number of aliases in service entry 588 589 function Aliases 590 (S : Service_Entry_Type; 591 N : Positive := 1) return String; 592 -- Return N'th aliases in service entry (the first index is 1) 593 594 function Get_Service_By_Name 595 (Name : String; 596 Protocol : String) return Service_Entry_Type; 597 -- Return service entry structure for the given service name 598 599 function Get_Service_By_Port 600 (Port : Port_Type; 601 Protocol : String) return Service_Entry_Type; 602 -- Return service entry structure for the given service port number 603 604 Service_Error : exception; 605 -- Comment required ??? 606 607 -- Errors are described by an enumeration type. There is only one exception 608 -- Socket_Error in this package to deal with an error during a socket 609 -- routine. Once raised, its message contains the error code between 610 -- brackets and a string describing the error code. 611 612 -- The name of the enumeration constant documents the error condition 613 -- Note that on some platforms, a single error value is used for both 614 -- EWOULDBLOCK and EAGAIN. Both errors are therefore always reported as 615 -- Resource_Temporarily_Unavailable. 616 617 type Error_Type is 618 (Success, 619 Permission_Denied, 620 Address_Already_In_Use, 621 Cannot_Assign_Requested_Address, 622 Address_Family_Not_Supported_By_Protocol, 623 Operation_Already_In_Progress, 624 Bad_File_Descriptor, 625 Software_Caused_Connection_Abort, 626 Connection_Refused, 627 Connection_Reset_By_Peer, 628 Destination_Address_Required, 629 Bad_Address, 630 Host_Is_Down, 631 No_Route_To_Host, 632 Operation_Now_In_Progress, 633 Interrupted_System_Call, 634 Invalid_Argument, 635 Input_Output_Error, 636 Transport_Endpoint_Already_Connected, 637 Too_Many_Symbolic_Links, 638 Too_Many_Open_Files, 639 Message_Too_Long, 640 File_Name_Too_Long, 641 Network_Is_Down, 642 Network_Dropped_Connection_Because_Of_Reset, 643 Network_Is_Unreachable, 644 No_Buffer_Space_Available, 645 Protocol_Not_Available, 646 Transport_Endpoint_Not_Connected, 647 Socket_Operation_On_Non_Socket, 648 Operation_Not_Supported, 649 Protocol_Family_Not_Supported, 650 Protocol_Not_Supported, 651 Protocol_Wrong_Type_For_Socket, 652 Cannot_Send_After_Transport_Endpoint_Shutdown, 653 Socket_Type_Not_Supported, 654 Connection_Timed_Out, 655 Too_Many_References, 656 Resource_Temporarily_Unavailable, 657 Broken_Pipe, 658 Unknown_Host, 659 Host_Name_Lookup_Failure, 660 Non_Recoverable_Error, 661 Unknown_Server_Error, 662 Cannot_Resolve_Error); 663 664 -- Get_Socket_Options and Set_Socket_Options manipulate options associated 665 -- with a socket. Options may exist at multiple protocol levels in the 666 -- communication stack. Socket_Level is the uppermost socket level. 667 668 type Level_Type is 669 (Socket_Level, 670 IP_Protocol_For_IP_Level, 671 IP_Protocol_For_UDP_Level, 672 IP_Protocol_For_TCP_Level); 673 674 -- There are several options available to manipulate sockets. Each option 675 -- has a name and several values available. Most of the time, the value is 676 -- a boolean to enable or disable this option. 677 678 type Option_Name is 679 (Keep_Alive, -- Enable sending of keep-alive messages 680 Reuse_Address, -- Allow bind to reuse local address 681 Broadcast, -- Enable datagram sockets to recv/send broadcasts 682 Send_Buffer, -- Set/get the maximum socket send buffer in bytes 683 Receive_Buffer, -- Set/get the maximum socket recv buffer in bytes 684 Linger, -- Shutdown wait for msg to be sent or timeout occur 685 Error, -- Get and clear the pending socket error 686 No_Delay, -- Do not delay send to coalesce data (TCP_NODELAY) 687 Add_Membership, -- Join a multicast group 688 Drop_Membership, -- Leave a multicast group 689 Multicast_If, -- Set default out interface for multicast packets 690 Multicast_TTL, -- Set the time-to-live of sent multicast packets 691 Multicast_Loop, -- Sent multicast packets are looped to local socket 692 Receive_Packet_Info, -- Receive low level packet info as ancillary data 693 Send_Timeout, -- Set timeout value for output 694 Receive_Timeout); -- Set timeout value for input 695 696 type Option_Type (Name : Option_Name := Keep_Alive) is record 697 case Name is 698 when Keep_Alive | 699 Reuse_Address | 700 Broadcast | 701 Linger | 702 No_Delay | 703 Receive_Packet_Info | 704 Multicast_Loop => 705 Enabled : Boolean; 706 707 case Name is 708 when Linger => 709 Seconds : Natural; 710 when others => 711 null; 712 end case; 713 714 when Send_Buffer | 715 Receive_Buffer => 716 Size : Natural; 717 718 when Error => 719 Error : Error_Type; 720 721 when Add_Membership | 722 Drop_Membership => 723 Multicast_Address : Inet_Addr_Type; 724 Local_Interface : Inet_Addr_Type; 725 726 when Multicast_If => 727 Outgoing_If : Inet_Addr_Type; 728 729 when Multicast_TTL => 730 Time_To_Live : Natural; 731 732 when Send_Timeout | 733 Receive_Timeout => 734 Timeout : Timeval_Duration; 735 736 end case; 737 end record; 738 739 -- There are several controls available to manipulate sockets. Each option 740 -- has a name and several values available. These controls differ from the 741 -- socket options in that they are not specific to sockets but are 742 -- available for any device. 743 744 type Request_Name is 745 (Non_Blocking_IO, -- Cause a caller not to wait on blocking operations 746 N_Bytes_To_Read); -- Return the number of bytes available to read 747 748 type Request_Type (Name : Request_Name := Non_Blocking_IO) is record 749 case Name is 750 when Non_Blocking_IO => 751 Enabled : Boolean; 752 753 when N_Bytes_To_Read => 754 Size : Natural; 755 756 end case; 757 end record; 758 759 -- A request flag allows specification of the type of message transmissions 760 -- or receptions. A request flag can be combination of zero or more 761 -- predefined request flags. 762 763 type Request_Flag_Type is private; 764 765 No_Request_Flag : constant Request_Flag_Type; 766 -- This flag corresponds to the normal execution of an operation 767 768 Process_Out_Of_Band_Data : constant Request_Flag_Type; 769 -- This flag requests that the receive or send function operates on 770 -- out-of-band data when the socket supports this notion (e.g. 771 -- Socket_Stream). 772 773 Peek_At_Incoming_Data : constant Request_Flag_Type; 774 -- This flag causes the receive operation to return data from the beginning 775 -- of the receive queue without removing that data from the queue. A 776 -- subsequent receive call will return the same data. 777 778 Wait_For_A_Full_Reception : constant Request_Flag_Type; 779 -- This flag requests that the operation block until the full request is 780 -- satisfied. However, the call may still return less data than requested 781 -- if a signal is caught, an error or disconnect occurs, or the next data 782 -- to be received is of a different type than that returned. Note that 783 -- this flag depends on support in the underlying sockets implementation, 784 -- and is not supported under Windows. 785 786 Send_End_Of_Record : constant Request_Flag_Type; 787 -- This flag indicates that the entire message has been sent and so this 788 -- terminates the record. 789 790 function "+" (L, R : Request_Flag_Type) return Request_Flag_Type; 791 -- Combine flag L with flag R 792 793 type Stream_Element_Reference is access all Ada.Streams.Stream_Element; 794 795 type Vector_Element is record 796 Base : Stream_Element_Reference; 797 Length : Interfaces.C.size_t; 798 end record; 799 800 type Vector_Type is array (Integer range <>) of Vector_Element; 801 802 procedure Create_Socket 803 (Socket : out Socket_Type; 804 Family : Family_Type := Family_Inet; 805 Mode : Mode_Type := Socket_Stream); 806 -- Create an endpoint for communication. Raises Socket_Error on error 807 808 procedure Accept_Socket 809 (Server : Socket_Type; 810 Socket : out Socket_Type; 811 Address : out Sock_Addr_Type); 812 -- Extracts the first connection request on the queue of pending 813 -- connections, creates a new connected socket with mostly the same 814 -- properties as Server, and allocates a new socket. The returned Address 815 -- is filled in with the address of the connection. Raises Socket_Error on 816 -- error. Note: if Server is a non-blocking socket, whether or not this 817 -- aspect is inherited by Socket is platform-dependent. 818 819 procedure Accept_Socket 820 (Server : Socket_Type; 821 Socket : out Socket_Type; 822 Address : out Sock_Addr_Type; 823 Timeout : Selector_Duration; 824 Selector : access Selector_Type := null; 825 Status : out Selector_Status); 826 -- Accept a new connection on Server using Accept_Socket, waiting no longer 827 -- than the given timeout duration. Status is set to indicate whether the 828 -- operation completed successfully, timed out, or was aborted. If Selector 829 -- is not null, the designated selector is used to wait for the socket to 830 -- become available, else a private selector object is created by this 831 -- procedure and destroyed before it returns. 832 833 procedure Bind_Socket 834 (Socket : Socket_Type; 835 Address : Sock_Addr_Type); 836 -- Once a socket is created, assign a local address to it. Raise 837 -- Socket_Error on error. 838 839 procedure Close_Socket (Socket : Socket_Type); 840 -- Close a socket and more specifically a non-connected socket 841 842 procedure Connect_Socket 843 (Socket : Socket_Type; 844 Server : Sock_Addr_Type); 845 -- Make a connection to another socket which has the address of Server. 846 -- Raises Socket_Error on error. 847 848 procedure Connect_Socket 849 (Socket : Socket_Type; 850 Server : Sock_Addr_Type; 851 Timeout : Selector_Duration; 852 Selector : access Selector_Type := null; 853 Status : out Selector_Status); 854 -- Connect Socket to the given Server address using Connect_Socket, waiting 855 -- no longer than the given timeout duration. Status is set to indicate 856 -- whether the operation completed successfully, timed out, or was aborted. 857 -- If Selector is not null, the designated selector is used to wait for the 858 -- socket to become available, else a private selector object is created 859 -- by this procedure and destroyed before it returns. If Timeout is 0.0, 860 -- no attempt is made to detect whether the connection has succeeded; it 861 -- is up to the user to determine this using Check_Selector later on. 862 863 procedure Control_Socket 864 (Socket : Socket_Type; 865 Request : in out Request_Type); 866 -- Obtain or set parameter values that control the socket. This control 867 -- differs from the socket options in that they are not specific to sockets 868 -- but are available for any device. 869 870 function Get_Peer_Name (Socket : Socket_Type) return Sock_Addr_Type; 871 -- Return the peer or remote socket address of a socket. Raise 872 -- Socket_Error on error. 873 874 function Get_Socket_Name (Socket : Socket_Type) return Sock_Addr_Type; 875 -- Return the local or current socket address of a socket. Return 876 -- No_Sock_Addr on error (e.g. socket closed or not locally bound). 877 878 function Get_Socket_Option 879 (Socket : Socket_Type; 880 Level : Level_Type := Socket_Level; 881 Name : Option_Name) return Option_Type; 882 -- Get the options associated with a socket. Raises Socket_Error on error 883 884 procedure Listen_Socket 885 (Socket : Socket_Type; 886 Length : Natural := 15); 887 -- To accept connections, a socket is first created with Create_Socket, 888 -- a willingness to accept incoming connections and a queue Length for 889 -- incoming connections are specified. Raise Socket_Error on error. 890 -- The queue length of 15 is an example value that should be appropriate 891 -- in usual cases. It can be adjusted according to each application's 892 -- particular requirements. 893 894 procedure Receive_Socket 895 (Socket : Socket_Type; 896 Item : out Ada.Streams.Stream_Element_Array; 897 Last : out Ada.Streams.Stream_Element_Offset; 898 Flags : Request_Flag_Type := No_Request_Flag); 899 -- Receive message from Socket. Last is the index value such that Item 900 -- (Last) is the last character assigned. Note that Last is set to 901 -- Item'First - 1 when the socket has been closed by peer. This is not 902 -- an error, and no exception is raised in this case unless Item'First 903 -- is Stream_Element_Offset'First, in which case Constraint_Error is 904 -- raised. Flags allows control of the reception. Raise Socket_Error on 905 -- error. 906 907 procedure Receive_Socket 908 (Socket : Socket_Type; 909 Item : out Ada.Streams.Stream_Element_Array; 910 Last : out Ada.Streams.Stream_Element_Offset; 911 From : out Sock_Addr_Type; 912 Flags : Request_Flag_Type := No_Request_Flag); 913 -- Receive message from Socket. If Socket is not connection-oriented, the 914 -- source address From of the message is filled in. Last is the index 915 -- value such that Item (Last) is the last character assigned. Flags 916 -- allows control of the reception. Raises Socket_Error on error. 917 918 procedure Receive_Vector 919 (Socket : Socket_Type; 920 Vector : Vector_Type; 921 Count : out Ada.Streams.Stream_Element_Count; 922 Flags : Request_Flag_Type := No_Request_Flag); 923 -- Receive data from a socket and scatter it into the set of vector 924 -- elements Vector. Count is set to the count of received stream elements. 925 -- Flags allow control over reception. 926 927 function Resolve_Exception 928 (Occurrence : Ada.Exceptions.Exception_Occurrence) return Error_Type; 929 -- When Socket_Error or Host_Error are raised, the exception message 930 -- contains the error code between brackets and a string describing the 931 -- error code. Resolve_Error extracts the error code from an exception 932 -- message and translate it into an enumeration value. 933 934 procedure Send_Socket 935 (Socket : Socket_Type; 936 Item : Ada.Streams.Stream_Element_Array; 937 Last : out Ada.Streams.Stream_Element_Offset; 938 To : access Sock_Addr_Type; 939 Flags : Request_Flag_Type := No_Request_Flag); 940 pragma Inline (Send_Socket); 941 -- Transmit a message over a socket. For a datagram socket, the address 942 -- is given by To.all. For a stream socket, To must be null. Last 943 -- is the index value such that Item (Last) is the last character 944 -- sent. Note that Last is set to Item'First - 1 if the socket has been 945 -- closed by the peer (unless Item'First is Stream_Element_Offset'First, 946 -- in which case Constraint_Error is raised instead). This is not an error, 947 -- and Socket_Error is not raised in that case. Flags allows control of the 948 -- transmission. Raises exception Socket_Error on error. Note: this 949 -- subprogram is inlined because it is also used to implement the two 950 -- variants below. 951 952 procedure Send_Socket 953 (Socket : Socket_Type; 954 Item : Ada.Streams.Stream_Element_Array; 955 Last : out Ada.Streams.Stream_Element_Offset; 956 Flags : Request_Flag_Type := No_Request_Flag); 957 -- Transmit a message over a socket. Upon return, Last is set to the index 958 -- within Item of the last element transmitted. Flags allows control of 959 -- the transmission. Raises Socket_Error on any detected error condition. 960 961 procedure Send_Socket 962 (Socket : Socket_Type; 963 Item : Ada.Streams.Stream_Element_Array; 964 Last : out Ada.Streams.Stream_Element_Offset; 965 To : Sock_Addr_Type; 966 Flags : Request_Flag_Type := No_Request_Flag); 967 -- Transmit a message over a datagram socket. The destination address is 968 -- To. Flags allows control of the transmission. Raises Socket_Error on 969 -- error. 970 971 procedure Send_Vector 972 (Socket : Socket_Type; 973 Vector : Vector_Type; 974 Count : out Ada.Streams.Stream_Element_Count; 975 Flags : Request_Flag_Type := No_Request_Flag); 976 -- Transmit data gathered from the set of vector elements Vector to a 977 -- socket. Count is set to the count of transmitted stream elements. Flags 978 -- allow control over transmission. 979 980 procedure Set_Close_On_Exec 981 (Socket : Socket_Type; 982 Close_On_Exec : Boolean; 983 Status : out Boolean); 984 -- When Close_On_Exec is True, mark Socket to be closed automatically when 985 -- a new program is executed by the calling process (i.e. prevent Socket 986 -- from being inherited by child processes). When Close_On_Exec is False, 987 -- mark Socket to not be closed on exec (i.e. allow it to be inherited). 988 -- Status is False if the operation could not be performed, or is not 989 -- supported on the target platform. 990 991 procedure Set_Socket_Option 992 (Socket : Socket_Type; 993 Level : Level_Type := Socket_Level; 994 Option : Option_Type); 995 -- Manipulate socket options. Raises Socket_Error on error 996 997 procedure Shutdown_Socket 998 (Socket : Socket_Type; 999 How : Shutmode_Type := Shut_Read_Write); 1000 -- Shutdown a connected socket. If How is Shut_Read further receives will 1001 -- be disallowed. If How is Shut_Write further sends will be disallowed. 1002 -- If How is Shut_Read_Write further sends and receives will be disallowed. 1003 1004 type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class; 1005 -- Same interface as Ada.Streams.Stream_IO 1006 1007 function Stream (Socket : Socket_Type) return Stream_Access; 1008 -- Create a stream associated with an already connected stream-based socket 1009 1010 function Stream 1011 (Socket : Socket_Type; 1012 Send_To : Sock_Addr_Type) return Stream_Access; 1013 -- Create a stream associated with an already bound datagram-based socket. 1014 -- Send_To is the destination address to which messages are being sent. 1015 1016 function Get_Address 1017 (Stream : not null Stream_Access) return Sock_Addr_Type; 1018 -- Return the socket address from which the last message was received 1019 1020 procedure Free is new Ada.Unchecked_Deallocation 1021 (Ada.Streams.Root_Stream_Type'Class, Stream_Access); 1022 -- Destroy a stream created by one of the Stream functions above, releasing 1023 -- the corresponding resources. The user is responsible for calling this 1024 -- subprogram when the stream is not needed anymore. 1025 1026 type Socket_Set_Type is limited private; 1027 -- This type allows manipulation of sets of sockets. It allows waiting 1028 -- for events on multiple endpoints at one time. This type has default 1029 -- initialization, and the default value is the empty set. 1030 -- 1031 -- Note: This type used to contain a pointer to dynamically allocated 1032 -- storage, but this is not the case anymore, and no special precautions 1033 -- are required to avoid memory leaks. 1034 1035 procedure Clear (Item : in out Socket_Set_Type; Socket : Socket_Type); 1036 -- Remove Socket from Item 1037 1038 procedure Copy (Source : Socket_Set_Type; Target : out Socket_Set_Type); 1039 -- Copy Source into Target as Socket_Set_Type is limited private 1040 1041 procedure Empty (Item : out Socket_Set_Type); 1042 -- Remove all Sockets from Item 1043 1044 procedure Get (Item : in out Socket_Set_Type; Socket : out Socket_Type); 1045 -- Extract a Socket from socket set Item. Socket is set to 1046 -- No_Socket when the set is empty. 1047 1048 function Is_Empty (Item : Socket_Set_Type) return Boolean; 1049 -- Return True iff Item is empty 1050 1051 function Is_Set 1052 (Item : Socket_Set_Type; 1053 Socket : Socket_Type) return Boolean; 1054 -- Return True iff Socket is present in Item 1055 1056 procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type); 1057 -- Insert Socket into Item 1058 1059 function Image (Item : Socket_Set_Type) return String; 1060 -- Return a printable image of Item, for debugging purposes 1061 1062 -- The select(2) system call waits for events to occur on any of a set of 1063 -- file descriptors. Usually, three independent sets of descriptors are 1064 -- watched (read, write and exception). A timeout gives an upper bound 1065 -- on the amount of time elapsed before select returns. This function 1066 -- blocks until an event occurs. On some platforms, the select(2) system 1067 -- can block the full process (not just the calling thread). 1068 -- 1069 -- Check_Selector provides the very same behavior. The only difference is 1070 -- that it does not watch for exception events. Note that on some platforms 1071 -- it is kept process blocking on purpose. The timeout parameter allows the 1072 -- user to have the behavior he wants. Abort_Selector allows the safe 1073 -- abort of a blocked Check_Selector call. A special socket is opened by 1074 -- Create_Selector and included in each call to Check_Selector. 1075 -- 1076 -- Abort_Selector causes an event to occur on this descriptor in order to 1077 -- unblock Check_Selector. Note that each call to Abort_Selector will cause 1078 -- exactly one call to Check_Selector to return with Aborted status. The 1079 -- special socket created by Create_Selector is closed when Close_Selector 1080 -- is called. 1081 -- 1082 -- A typical case where it is useful to abort a Check_Selector operation is 1083 -- the situation where a change to the monitored sockets set must be made. 1084 1085 procedure Create_Selector (Selector : out Selector_Type); 1086 -- Initialize (open) a new selector 1087 1088 procedure Close_Selector (Selector : in out Selector_Type); 1089 -- Close Selector and all internal descriptors associated; deallocate any 1090 -- associated resources. This subprogram may be called only when there is 1091 -- no other task still using Selector (i.e. still executing Check_Selector 1092 -- or Abort_Selector on this Selector). Has no effect if Selector is 1093 -- already closed. 1094 1095 procedure Check_Selector 1096 (Selector : Selector_Type; 1097 R_Socket_Set : in out Socket_Set_Type; 1098 W_Socket_Set : in out Socket_Set_Type; 1099 Status : out Selector_Status; 1100 Timeout : Selector_Duration := Forever); 1101 -- Return when one Socket in R_Socket_Set has some data to be read or if 1102 -- one Socket in W_Socket_Set is ready to transmit some data. In these 1103 -- cases Status is set to Completed and sockets that are ready are set in 1104 -- R_Socket_Set or W_Socket_Set. Status is set to Expired if no socket was 1105 -- ready after a Timeout expiration. Status is set to Aborted if an abort 1106 -- signal has been received while checking socket status. 1107 -- 1108 -- Note that two different Socket_Set_Type objects must be passed as 1109 -- R_Socket_Set and W_Socket_Set (even if they denote the same set of 1110 -- Sockets), or some event may be lost. 1111 -- 1112 -- Socket_Error is raised when the select(2) system call returns an error 1113 -- condition, or when a read error occurs on the signalling socket used for 1114 -- the implementation of Abort_Selector. 1115 1116 procedure Check_Selector 1117 (Selector : Selector_Type; 1118 R_Socket_Set : in out Socket_Set_Type; 1119 W_Socket_Set : in out Socket_Set_Type; 1120 E_Socket_Set : in out Socket_Set_Type; 1121 Status : out Selector_Status; 1122 Timeout : Selector_Duration := Forever); 1123 -- This refined version of Check_Selector allows watching for exception 1124 -- events (i.e. notifications of out-of-band transmission and reception). 1125 -- As above, all of R_Socket_Set, W_Socket_Set and E_Socket_Set must be 1126 -- different objects. 1127 1128 procedure Abort_Selector (Selector : Selector_Type); 1129 -- Send an abort signal to the selector. The Selector may not be the 1130 -- Null_Selector. 1131 1132 type Fd_Set is private; 1133 -- ??? This type must not be used directly, it needs to be visible because 1134 -- it is used in the visible part of GNAT.Sockets.Thin_Common. This is 1135 -- really an inversion of abstraction. The private part of GNAT.Sockets 1136 -- needs to have visibility on this type, but since Thin_Common is a child 1137 -- of Sockets, the type can't be declared there. The correct fix would 1138 -- be to move the thin sockets binding outside of GNAT.Sockets altogether, 1139 -- e.g. by renaming it to GNAT.Sockets_Thin. 1140 1141private 1142 1143 type Socket_Type is new Integer; 1144 No_Socket : constant Socket_Type := -1; 1145 1146 -- A selector is either a null selector, which is always "open" and can 1147 -- never be aborted, or a regular selector, which is created "closed", 1148 -- becomes "open" when Create_Selector is called, and "closed" again when 1149 -- Close_Selector is called. 1150 1151 type Selector_Type (Is_Null : Boolean := False) is limited record 1152 case Is_Null is 1153 when True => 1154 null; 1155 1156 when False => 1157 R_Sig_Socket : Socket_Type := No_Socket; 1158 W_Sig_Socket : Socket_Type := No_Socket; 1159 -- Signalling sockets used to abort a select operation 1160 end case; 1161 end record; 1162 1163 pragma Volatile (Selector_Type); 1164 1165 Null_Selector : constant Selector_Type := (Is_Null => True); 1166 1167 type Fd_Set is 1168 new System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_fd_set); 1169 for Fd_Set'Alignment use Interfaces.C.long'Alignment; 1170 -- Set conservative alignment so that our Fd_Sets are always adequately 1171 -- aligned for the underlying data type (which is implementation defined 1172 -- and may be an array of C long integers). 1173 1174 type Fd_Set_Access is access all Fd_Set; 1175 pragma Convention (C, Fd_Set_Access); 1176 No_Fd_Set_Access : constant Fd_Set_Access := null; 1177 1178 type Socket_Set_Type is record 1179 Last : Socket_Type := No_Socket; 1180 -- Highest socket in set. Last = No_Socket denotes an empty set (which 1181 -- is the default initial value). 1182 1183 Set : aliased Fd_Set; 1184 -- Underlying socket set. Note that the contents of this component is 1185 -- undefined if Last = No_Socket. 1186 end record; 1187 1188 subtype Inet_Addr_Comp_Type is Natural range 0 .. 255; 1189 -- Octet for Internet address 1190 1191 type Inet_Addr_VN_Type is array (Natural range <>) of Inet_Addr_Comp_Type; 1192 1193 subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 .. 4); 1194 subtype Inet_Addr_V6_Type is Inet_Addr_VN_Type (1 .. 16); 1195 1196 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is record 1197 case Family is 1198 when Family_Inet => 1199 Sin_V4 : Inet_Addr_V4_Type := (others => 0); 1200 1201 when Family_Inet6 => 1202 Sin_V6 : Inet_Addr_V6_Type := (others => 0); 1203 end case; 1204 end record; 1205 1206 Any_Port : constant Port_Type := 0; 1207 No_Port : constant Port_Type := 0; 1208 1209 Any_Inet_Addr : constant Inet_Addr_Type := 1210 (Family_Inet, (others => 0)); 1211 No_Inet_Addr : constant Inet_Addr_Type := 1212 (Family_Inet, (others => 0)); 1213 Broadcast_Inet_Addr : constant Inet_Addr_Type := 1214 (Family_Inet, (others => 255)); 1215 Loopback_Inet_Addr : constant Inet_Addr_Type := 1216 (Family_Inet, (127, 0, 0, 1)); 1217 1218 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type := 1219 (Family_Inet, (224, 0, 0, 0)); 1220 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type := 1221 (Family_Inet, (224, 0, 0, 1)); 1222 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type := 1223 (Family_Inet, (224, 0, 0, 2)); 1224 1225 No_Sock_Addr : constant Sock_Addr_Type := (Family_Inet, No_Inet_Addr, 0); 1226 1227 Max_Name_Length : constant := 64; 1228 -- The constant MAXHOSTNAMELEN is usually set to 64 1229 1230 subtype Name_Index is Natural range 1 .. Max_Name_Length; 1231 1232 type Name_Type (Length : Name_Index := Max_Name_Length) is record 1233 Name : String (1 .. Length); 1234 end record; 1235 -- We need fixed strings to avoid access types in host entry type 1236 1237 type Name_Array is array (Natural range <>) of Name_Type; 1238 type Inet_Addr_Array is array (Natural range <>) of Inet_Addr_Type; 1239 1240 type Host_Entry_Type (Aliases_Length, Addresses_Length : Natural) is record 1241 Official : Name_Type; 1242 Aliases : Name_Array (1 .. Aliases_Length); 1243 Addresses : Inet_Addr_Array (1 .. Addresses_Length); 1244 end record; 1245 1246 type Service_Entry_Type (Aliases_Length : Natural) is record 1247 Official : Name_Type; 1248 Aliases : Name_Array (1 .. Aliases_Length); 1249 Port : Port_Type; 1250 Protocol : Name_Type; 1251 end record; 1252 1253 type Request_Flag_Type is mod 2 ** 8; 1254 No_Request_Flag : constant Request_Flag_Type := 0; 1255 Process_Out_Of_Band_Data : constant Request_Flag_Type := 1; 1256 Peek_At_Incoming_Data : constant Request_Flag_Type := 2; 1257 Wait_For_A_Full_Reception : constant Request_Flag_Type := 4; 1258 Send_End_Of_Record : constant Request_Flag_Type := 8; 1259 1260end GNAT.Sockets; 1261