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) 2001-2013, 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-- The VMS implementation was implemented using the DECC RTL Socket API, 43-- and is thus subject to limitations in the implementation of this API. 44 45-- VxWorks cross ports fully implement this package 46 47-- This package is not yet implemented on LynxOS or other cross ports 48 49with Ada.Exceptions; 50with Ada.Streams; 51with Ada.Unchecked_Deallocation; 52 53with Interfaces.C; 54 55with System.OS_Constants; 56with System.Storage_Elements; 57 58package GNAT.Sockets is 59 60 -- Sockets are designed to provide a consistent communication facility 61 -- between applications. This package provides an Ada binding to the 62 -- de-facto standard BSD sockets API. The documentation below covers 63 -- only the specific binding provided by this package. It assumes that 64 -- the reader is already familiar with general network programming and 65 -- sockets usage. A useful reference on this matter is W. Richard Stevens' 66 -- "UNIX Network Programming: The Sockets Networking API" 67 -- (ISBN: 0131411551). 68 69 -- GNAT.Sockets has been designed with several ideas in mind 70 71 -- This is a system independent interface. Therefore, we try as much as 72 -- possible to mask system incompatibilities. Some functionalities are not 73 -- available because there are not fully supported on some systems. 74 75 -- This is a thick binding. For instance, a major effort has been done to 76 -- avoid using memory addresses or untyped ints. We preferred to define 77 -- streams and enumeration types. Errors are not returned as returned 78 -- values but as exceptions. 79 80 -- This package provides a POSIX-compliant interface (between two 81 -- different implementations of the same routine, we adopt the one closest 82 -- to the POSIX specification). For instance, using select(), the 83 -- notification of an asynchronous connect failure is delivered in the 84 -- write socket set (POSIX) instead of the exception socket set (NT). 85 86 -- The example below demonstrates various features of GNAT.Sockets: 87 88 -- with GNAT.Sockets; use GNAT.Sockets; 89 90 -- with Ada.Text_IO; 91 -- with Ada.Exceptions; use Ada.Exceptions; 92 93 -- procedure PingPong is 94 95 -- Group : constant String := "239.255.128.128"; 96 -- -- Multicast group: administratively scoped IP address 97 98 -- task Pong is 99 -- entry Start; 100 -- entry Stop; 101 -- end Pong; 102 103 -- task body Pong is 104 -- Address : Sock_Addr_Type; 105 -- Server : Socket_Type; 106 -- Socket : Socket_Type; 107 -- Channel : Stream_Access; 108 109 -- begin 110 -- -- Get an Internet address of a host (here the local host name). 111 -- -- Note that a host can have several addresses. Here we get 112 -- -- the first one which is supposed to be the official one. 113 114 -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); 115 116 -- -- Get a socket address that is an Internet address and a port 117 118 -- Address.Port := 5876; 119 120 -- -- The first step is to create a socket. Once created, this 121 -- -- socket must be associated to with an address. Usually only a 122 -- -- server (Pong here) needs to bind an address explicitly. Most 123 -- -- of the time clients can skip this step because the socket 124 -- -- routines will bind an arbitrary address to an unbound socket. 125 126 -- Create_Socket (Server); 127 128 -- -- Allow reuse of local addresses 129 130 -- Set_Socket_Option 131 -- (Server, 132 -- Socket_Level, 133 -- (Reuse_Address, True)); 134 135 -- Bind_Socket (Server, Address); 136 137 -- -- A server marks a socket as willing to receive connect events 138 139 -- Listen_Socket (Server); 140 141 -- -- Once a server calls Listen_Socket, incoming connects events 142 -- -- can be accepted. The returned Socket is a new socket that 143 -- -- represents the server side of the connection. Server remains 144 -- -- available to receive further connections. 145 146 -- accept Start; 147 148 -- Accept_Socket (Server, Socket, Address); 149 150 -- -- Return a stream associated to the connected socket 151 152 -- Channel := Stream (Socket); 153 154 -- -- Force Pong to block 155 156 -- delay 0.2; 157 158 -- -- Receive and print message from client Ping 159 160 -- declare 161 -- Message : String := String'Input (Channel); 162 163 -- begin 164 -- Ada.Text_IO.Put_Line (Message); 165 166 -- -- Send same message back to client Ping 167 168 -- String'Output (Channel, Message); 169 -- end; 170 171 -- Close_Socket (Server); 172 -- Close_Socket (Socket); 173 174 -- -- Part of the multicast example 175 176 -- -- Create a datagram socket to send connectionless, unreliable 177 -- -- messages of a fixed maximum length. 178 179 -- Create_Socket (Socket, Family_Inet, Socket_Datagram); 180 181 -- -- Allow reuse of local addresses 182 183 -- Set_Socket_Option 184 -- (Socket, 185 -- Socket_Level, 186 -- (Reuse_Address, True)); 187 188 -- -- Controls the live time of the datagram to avoid it being 189 -- -- looped forever due to routing errors. Routers decrement 190 -- -- the TTL of every datagram as it traverses from one network 191 -- -- to another and when its value reaches 0 the packet is 192 -- -- dropped. Default is 1. 193 194 -- Set_Socket_Option 195 -- (Socket, 196 -- IP_Protocol_For_IP_Level, 197 -- (Multicast_TTL, 1)); 198 199 -- -- Want the data you send to be looped back to your host 200 201 -- Set_Socket_Option 202 -- (Socket, 203 -- IP_Protocol_For_IP_Level, 204 -- (Multicast_Loop, True)); 205 206 -- -- If this socket is intended to receive messages, bind it 207 -- -- to a given socket address. 208 209 -- Address.Addr := Any_Inet_Addr; 210 -- Address.Port := 55505; 211 212 -- Bind_Socket (Socket, Address); 213 214 -- -- Join a multicast group 215 216 -- -- Portability note: On Windows, this option may be set only 217 -- -- on a bound socket. 218 219 -- Set_Socket_Option 220 -- (Socket, 221 -- IP_Protocol_For_IP_Level, 222 -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); 223 224 -- -- If this socket is intended to send messages, provide the 225 -- -- receiver socket address. 226 227 -- Address.Addr := Inet_Addr (Group); 228 -- Address.Port := 55506; 229 230 -- Channel := Stream (Socket, Address); 231 232 -- -- Receive and print message from client Ping 233 234 -- declare 235 -- Message : String := String'Input (Channel); 236 237 -- begin 238 -- -- Get the address of the sender 239 240 -- Address := Get_Address (Channel); 241 -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); 242 243 -- -- Send same message back to client Ping 244 245 -- String'Output (Channel, Message); 246 -- end; 247 248 -- Close_Socket (Socket); 249 250 -- accept Stop; 251 252 -- exception when E : others => 253 -- Ada.Text_IO.Put_Line 254 -- (Exception_Name (E) & ": " & Exception_Message (E)); 255 -- end Pong; 256 257 -- task Ping is 258 -- entry Start; 259 -- entry Stop; 260 -- end Ping; 261 262 -- task body Ping is 263 -- Address : Sock_Addr_Type; 264 -- Socket : Socket_Type; 265 -- Channel : Stream_Access; 266 267 -- begin 268 -- accept Start; 269 270 -- -- See comments in Ping section for the first steps 271 272 -- Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); 273 -- Address.Port := 5876; 274 -- Create_Socket (Socket); 275 276 -- Set_Socket_Option 277 -- (Socket, 278 -- Socket_Level, 279 -- (Reuse_Address, True)); 280 281 -- -- Force Ping to block 282 283 -- delay 0.2; 284 285 -- -- If the client's socket is not bound, Connect_Socket will 286 -- -- bind to an unused address. The client uses Connect_Socket to 287 -- -- create a logical connection between the client's socket and 288 -- -- a server's socket returned by Accept_Socket. 289 290 -- Connect_Socket (Socket, Address); 291 292 -- Channel := Stream (Socket); 293 294 -- -- Send message to server Pong 295 296 -- String'Output (Channel, "Hello world"); 297 298 -- -- Force Ping to block 299 300 -- delay 0.2; 301 302 -- -- Receive and print message from server Pong 303 304 -- Ada.Text_IO.Put_Line (String'Input (Channel)); 305 -- Close_Socket (Socket); 306 307 -- -- Part of multicast example. Code similar to Pong's one 308 309 -- Create_Socket (Socket, Family_Inet, Socket_Datagram); 310 311 -- Set_Socket_Option 312 -- (Socket, 313 -- Socket_Level, 314 -- (Reuse_Address, True)); 315 316 -- Set_Socket_Option 317 -- (Socket, 318 -- IP_Protocol_For_IP_Level, 319 -- (Multicast_TTL, 1)); 320 321 -- Set_Socket_Option 322 -- (Socket, 323 -- IP_Protocol_For_IP_Level, 324 -- (Multicast_Loop, True)); 325 326 -- Address.Addr := Any_Inet_Addr; 327 -- Address.Port := 55506; 328 329 -- Bind_Socket (Socket, Address); 330 331 -- Set_Socket_Option 332 -- (Socket, 333 -- IP_Protocol_For_IP_Level, 334 -- (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); 335 336 -- Address.Addr := Inet_Addr (Group); 337 -- Address.Port := 55505; 338 339 -- Channel := Stream (Socket, Address); 340 341 -- -- Send message to server Pong 342 343 -- String'Output (Channel, "Hello world"); 344 345 -- -- Receive and print message from server Pong 346 347 -- declare 348 -- Message : String := String'Input (Channel); 349 350 -- begin 351 -- Address := Get_Address (Channel); 352 -- Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); 353 -- end; 354 355 -- Close_Socket (Socket); 356 357 -- accept Stop; 358 359 -- exception when E : others => 360 -- Ada.Text_IO.Put_Line 361 -- (Exception_Name (E) & ": " & Exception_Message (E)); 362 -- end Ping; 363 364 -- begin 365 -- Initialize; 366 -- Ping.Start; 367 -- Pong.Start; 368 -- Ping.Stop; 369 -- Pong.Stop; 370 -- Finalize; 371 -- end PingPong; 372 373 package SOSC renames System.OS_Constants; 374 -- Renaming used to provide short-hand notations throughout the sockets 375 -- binding. Note that System.OS_Constants is an internal unit, and the 376 -- entities declared therein are not meant for direct access by users, 377 -- including through this renaming. 378 379 procedure Initialize; 380 pragma Obsolescent 381 (Entity => Initialize, 382 Message => "explicit initialization is no longer required"); 383 -- Initialize must be called before using any other socket routines. 384 -- Note that this operation is a no-op on UNIX platforms, but applications 385 -- should make sure to call it if portability is expected: some platforms 386 -- (such as Windows) require initialization before any socket operation. 387 -- This is now a no-op (initialization and finalization are done 388 -- automatically). 389 390 procedure Initialize (Process_Blocking_IO : Boolean); 391 pragma Obsolescent 392 (Entity => Initialize, 393 Message => "passing a parameter to Initialize is no longer supported"); 394 -- Previous versions of GNAT.Sockets used to require the user to indicate 395 -- whether socket I/O was process- or thread-blocking on the platform. 396 -- This property is now determined automatically when the run-time library 397 -- is built. The old version of Initialize, taking a parameter, is kept 398 -- for compatibility reasons, but this interface is obsolete (and if the 399 -- value given is wrong, an exception will be raised at run time). 400 -- This is now a no-op (initialization and finalization are done 401 -- automatically). 402 403 procedure Finalize; 404 pragma Obsolescent 405 (Entity => Finalize, 406 Message => "explicit finalization is no longer required"); 407 -- After Finalize is called it is not possible to use any routines 408 -- exported in by this package. This procedure is idempotent. 409 -- This is now a no-op (initialization and finalization are done 410 -- automatically). 411 412 type Socket_Type is private; 413 -- Sockets are used to implement a reliable bi-directional point-to-point, 414 -- stream-based connections between hosts. No_Socket provides a special 415 -- value to denote uninitialized sockets. 416 417 No_Socket : constant Socket_Type; 418 419 type Selector_Type is limited private; 420 type Selector_Access is access all Selector_Type; 421 -- Selector objects are used to wait for i/o events to occur on sockets 422 423 Null_Selector : constant Selector_Type; 424 -- The Null_Selector can be used in place of a normal selector without 425 -- having to call Create_Selector if the use of Abort_Selector is not 426 -- required. 427 428 -- Timeval_Duration is a subtype of Standard.Duration because the full 429 -- range of Standard.Duration cannot be represented in the equivalent C 430 -- structure (struct timeval). Moreover, negative values are not allowed 431 -- to avoid system incompatibilities. 432 433 Immediate : constant Duration := 0.0; 434 435 Forever : constant Duration := 436 Duration'Min (Duration'Last, 1.0 * SOSC.MAX_tv_sec); 437 -- Largest possible Duration that is also a valid value for struct timeval 438 439 subtype Timeval_Duration is Duration range Immediate .. Forever; 440 441 subtype Selector_Duration is Timeval_Duration; 442 -- Timeout value for selector operations 443 444 type Selector_Status is (Completed, Expired, Aborted); 445 -- Completion status of a selector operation, indicated as follows: 446 -- Complete: one of the expected events occurred 447 -- Expired: no event occurred before the expiration of the timeout 448 -- Aborted: an external action cancelled the wait operation before 449 -- any event occurred. 450 451 Socket_Error : exception; 452 -- There is only one exception in this package to deal with an error during 453 -- a socket routine. Once raised, its message contains a string describing 454 -- the error code. 455 456 function Image (Socket : Socket_Type) return String; 457 -- Return a printable string for Socket 458 459 function To_C (Socket : Socket_Type) return Integer; 460 -- Return a file descriptor to be used by external subprograms. This is 461 -- useful for C functions that are not yet interfaced in this package. 462 463 type Family_Type is (Family_Inet, Family_Inet6); 464 -- Address family (or protocol family) identifies the communication domain 465 -- and groups protocols with similar address formats. 466 467 type Mode_Type is (Socket_Stream, Socket_Datagram); 468 -- Stream sockets provide connection-oriented byte streams. Datagram 469 -- sockets support unreliable connectionless message based communication. 470 471 type Shutmode_Type is (Shut_Read, Shut_Write, Shut_Read_Write); 472 -- When a process closes a socket, the policy is to retain any data queued 473 -- until either a delivery or a timeout expiration (in this case, the data 474 -- are discarded). A finer control is available through shutdown. With 475 -- Shut_Read, no more data can be received from the socket. With_Write, no 476 -- more data can be transmitted. Neither transmission nor reception can be 477 -- performed with Shut_Read_Write. 478 479 type Port_Type is range 0 .. 16#ffff#; 480 -- TCP/UDP port number 481 482 Any_Port : constant Port_Type; 483 -- All ports 484 485 No_Port : constant Port_Type; 486 -- Uninitialized port number 487 488 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is private; 489 -- An Internet address depends on an address family (IPv4 contains 4 octets 490 -- and IPv6 contains 16 octets). Any_Inet_Addr is a special value treated 491 -- like a wildcard enabling all addresses. No_Inet_Addr provides a special 492 -- value to denote uninitialized inet addresses. 493 494 Any_Inet_Addr : constant Inet_Addr_Type; 495 No_Inet_Addr : constant Inet_Addr_Type; 496 Broadcast_Inet_Addr : constant Inet_Addr_Type; 497 Loopback_Inet_Addr : constant Inet_Addr_Type; 498 499 -- Useful constants for IPv4 multicast addresses 500 501 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type; 502 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type; 503 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type; 504 505 type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record 506 Addr : Inet_Addr_Type (Family); 507 Port : Port_Type; 508 end record; 509 -- Socket addresses fully define a socket connection with protocol family, 510 -- an Internet address and a port. No_Sock_Addr provides a special value 511 -- for uninitialized socket addresses. 512 513 No_Sock_Addr : constant Sock_Addr_Type; 514 515 function Image (Value : Inet_Addr_Type) return String; 516 -- Return an image of an Internet address. IPv4 notation consists in 4 517 -- octets in decimal format separated by dots. IPv6 notation consists in 518 -- 16 octets in hexadecimal format separated by colons (and possibly 519 -- dots). 520 521 function Image (Value : Sock_Addr_Type) return String; 522 -- Return inet address image and port image separated by a colon 523 524 function Inet_Addr (Image : String) return Inet_Addr_Type; 525 -- Convert address image from numbers-and-dots notation into an 526 -- inet address. 527 528 -- Host entries provide complete information on a given host: the official 529 -- name, an array of alternative names or aliases and array of network 530 -- addresses. 531 532 type Host_Entry_Type 533 (Aliases_Length, Addresses_Length : Natural) is private; 534 535 function Official_Name (E : Host_Entry_Type) return String; 536 -- Return official name in host entry 537 538 function Aliases_Length (E : Host_Entry_Type) return Natural; 539 -- Return number of aliases in host entry 540 541 function Addresses_Length (E : Host_Entry_Type) return Natural; 542 -- Return number of addresses in host entry 543 544 function Aliases 545 (E : Host_Entry_Type; 546 N : Positive := 1) return String; 547 -- Return N'th aliases in host entry. The first index is 1 548 549 function Addresses 550 (E : Host_Entry_Type; 551 N : Positive := 1) return Inet_Addr_Type; 552 -- Return N'th addresses in host entry. The first index is 1 553 554 Host_Error : exception; 555 -- Exception raised by the two following procedures. Once raised, its 556 -- message contains a string describing the error code. This exception is 557 -- raised when an host entry cannot be retrieved. 558 559 function Get_Host_By_Address 560 (Address : Inet_Addr_Type; 561 Family : Family_Type := Family_Inet) return Host_Entry_Type; 562 -- Return host entry structure for the given Inet address. Note that no 563 -- result will be returned if there is no mapping of this IP address to a 564 -- host name in the system tables (host database, DNS or otherwise). 565 566 function Get_Host_By_Name 567 (Name : String) return Host_Entry_Type; 568 -- Return host entry structure for the given host name. Here name is 569 -- either a host name, or an IP address. If Name is an IP address, this 570 -- is equivalent to Get_Host_By_Address (Inet_Addr (Name)). 571 572 function Host_Name return String; 573 -- Return the name of the current host 574 575 type Service_Entry_Type (Aliases_Length : Natural) is private; 576 -- Service entries provide complete information on a given service: the 577 -- official name, an array of alternative names or aliases and the port 578 -- number. 579 580 function Official_Name (S : Service_Entry_Type) return String; 581 -- Return official name in service entry 582 583 function Port_Number (S : Service_Entry_Type) return Port_Type; 584 -- Return port number in service entry 585 586 function Protocol_Name (S : Service_Entry_Type) return String; 587 -- Return Protocol in service entry (usually UDP or TCP) 588 589 function Aliases_Length (S : Service_Entry_Type) return Natural; 590 -- Return number of aliases in service entry 591 592 function Aliases 593 (S : Service_Entry_Type; 594 N : Positive := 1) return String; 595 -- Return N'th aliases in service entry (the first index is 1) 596 597 function Get_Service_By_Name 598 (Name : String; 599 Protocol : String) return Service_Entry_Type; 600 -- Return service entry structure for the given service name 601 602 function Get_Service_By_Port 603 (Port : Port_Type; 604 Protocol : String) return Service_Entry_Type; 605 -- Return service entry structure for the given service port number 606 607 Service_Error : exception; 608 -- Comment required ??? 609 610 -- Errors are described by an enumeration type. There is only one exception 611 -- Socket_Error in this package to deal with an error during a socket 612 -- routine. Once raised, its message contains the error code between 613 -- brackets and a string describing the error code. 614 615 -- The name of the enumeration constant documents the error condition 616 -- Note that on some platforms, a single error value is used for both 617 -- EWOULDBLOCK and EAGAIN. Both errors are therefore always reported as 618 -- Resource_Temporarily_Unavailable. 619 620 type Error_Type is 621 (Success, 622 Permission_Denied, 623 Address_Already_In_Use, 624 Cannot_Assign_Requested_Address, 625 Address_Family_Not_Supported_By_Protocol, 626 Operation_Already_In_Progress, 627 Bad_File_Descriptor, 628 Software_Caused_Connection_Abort, 629 Connection_Refused, 630 Connection_Reset_By_Peer, 631 Destination_Address_Required, 632 Bad_Address, 633 Host_Is_Down, 634 No_Route_To_Host, 635 Operation_Now_In_Progress, 636 Interrupted_System_Call, 637 Invalid_Argument, 638 Input_Output_Error, 639 Transport_Endpoint_Already_Connected, 640 Too_Many_Symbolic_Links, 641 Too_Many_Open_Files, 642 Message_Too_Long, 643 File_Name_Too_Long, 644 Network_Is_Down, 645 Network_Dropped_Connection_Because_Of_Reset, 646 Network_Is_Unreachable, 647 No_Buffer_Space_Available, 648 Protocol_Not_Available, 649 Transport_Endpoint_Not_Connected, 650 Socket_Operation_On_Non_Socket, 651 Operation_Not_Supported, 652 Protocol_Family_Not_Supported, 653 Protocol_Not_Supported, 654 Protocol_Wrong_Type_For_Socket, 655 Cannot_Send_After_Transport_Endpoint_Shutdown, 656 Socket_Type_Not_Supported, 657 Connection_Timed_Out, 658 Too_Many_References, 659 Resource_Temporarily_Unavailable, 660 Broken_Pipe, 661 Unknown_Host, 662 Host_Name_Lookup_Failure, 663 Non_Recoverable_Error, 664 Unknown_Server_Error, 665 Cannot_Resolve_Error); 666 667 -- Get_Socket_Options and Set_Socket_Options manipulate options associated 668 -- with a socket. Options may exist at multiple protocol levels in the 669 -- communication stack. Socket_Level is the uppermost socket level. 670 671 type Level_Type is 672 (Socket_Level, 673 IP_Protocol_For_IP_Level, 674 IP_Protocol_For_UDP_Level, 675 IP_Protocol_For_TCP_Level); 676 677 -- There are several options available to manipulate sockets. Each option 678 -- has a name and several values available. Most of the time, the value is 679 -- a boolean to enable or disable this option. 680 681 type Option_Name is 682 (Keep_Alive, -- Enable sending of keep-alive messages 683 Reuse_Address, -- Allow bind to reuse local address 684 Broadcast, -- Enable datagram sockets to recv/send broadcasts 685 Send_Buffer, -- Set/get the maximum socket send buffer in bytes 686 Receive_Buffer, -- Set/get the maximum socket recv buffer in bytes 687 Linger, -- Shutdown wait for msg to be sent or timeout occur 688 Error, -- Get and clear the pending socket error 689 No_Delay, -- Do not delay send to coalesce data (TCP_NODELAY) 690 Add_Membership, -- Join a multicast group 691 Drop_Membership, -- Leave a multicast group 692 Multicast_If, -- Set default out interface for multicast packets 693 Multicast_TTL, -- Set the time-to-live of sent multicast packets 694 Multicast_Loop, -- Sent multicast packets are looped to local socket 695 Receive_Packet_Info, -- Receive low level packet info as ancillary data 696 Send_Timeout, -- Set timeout value for output 697 Receive_Timeout); -- Set timeout value for input 698 699 type Option_Type (Name : Option_Name := Keep_Alive) is record 700 case Name is 701 when Keep_Alive | 702 Reuse_Address | 703 Broadcast | 704 Linger | 705 No_Delay | 706 Receive_Packet_Info | 707 Multicast_Loop => 708 Enabled : Boolean; 709 710 case Name is 711 when Linger => 712 Seconds : Natural; 713 when others => 714 null; 715 end case; 716 717 when Send_Buffer | 718 Receive_Buffer => 719 Size : Natural; 720 721 when Error => 722 Error : Error_Type; 723 724 when Add_Membership | 725 Drop_Membership => 726 Multicast_Address : Inet_Addr_Type; 727 Local_Interface : Inet_Addr_Type; 728 729 when Multicast_If => 730 Outgoing_If : Inet_Addr_Type; 731 732 when Multicast_TTL => 733 Time_To_Live : Natural; 734 735 when Send_Timeout | 736 Receive_Timeout => 737 Timeout : Timeval_Duration; 738 739 end case; 740 end record; 741 742 -- There are several controls available to manipulate sockets. Each option 743 -- has a name and several values available. These controls differ from the 744 -- socket options in that they are not specific to sockets but are 745 -- available for any device. 746 747 type Request_Name is 748 (Non_Blocking_IO, -- Cause a caller not to wait on blocking operations 749 N_Bytes_To_Read); -- Return the number of bytes available to read 750 751 type Request_Type (Name : Request_Name := Non_Blocking_IO) is record 752 case Name is 753 when Non_Blocking_IO => 754 Enabled : Boolean; 755 756 when N_Bytes_To_Read => 757 Size : Natural; 758 759 end case; 760 end record; 761 762 -- A request flag allows to specify the type of message transmissions or 763 -- receptions. A request flag can be combination of zero or more 764 -- predefined request flags. 765 766 type Request_Flag_Type is private; 767 768 No_Request_Flag : constant Request_Flag_Type; 769 -- This flag corresponds to the normal execution of an operation 770 771 Process_Out_Of_Band_Data : constant Request_Flag_Type; 772 -- This flag requests that the receive or send function operates on 773 -- out-of-band data when the socket supports this notion (e.g. 774 -- Socket_Stream). 775 776 Peek_At_Incoming_Data : constant Request_Flag_Type; 777 -- This flag causes the receive operation to return data from the beginning 778 -- of the receive queue without removing that data from the queue. A 779 -- subsequent receive call will return the same data. 780 781 Wait_For_A_Full_Reception : constant Request_Flag_Type; 782 -- This flag requests that the operation block until the full request is 783 -- satisfied. However, the call may still return less data than requested 784 -- if a signal is caught, an error or disconnect occurs, or the next data 785 -- to be received is of a different type than that returned. Note that 786 -- this flag depends on support in the underlying sockets implementation, 787 -- and is not supported under Windows. 788 789 Send_End_Of_Record : constant Request_Flag_Type; 790 -- This flag indicates that the entire message has been sent and so this 791 -- terminates the record. 792 793 function "+" (L, R : Request_Flag_Type) return Request_Flag_Type; 794 -- Combine flag L with flag R 795 796 type Stream_Element_Reference is access all Ada.Streams.Stream_Element; 797 798 type Vector_Element is record 799 Base : Stream_Element_Reference; 800 Length : Ada.Streams.Stream_Element_Count; 801 end record; 802 803 type Vector_Type is array (Integer range <>) of Vector_Element; 804 805 procedure Create_Socket 806 (Socket : out Socket_Type; 807 Family : Family_Type := Family_Inet; 808 Mode : Mode_Type := Socket_Stream); 809 -- Create an endpoint for communication. Raises Socket_Error on error 810 811 procedure Accept_Socket 812 (Server : Socket_Type; 813 Socket : out Socket_Type; 814 Address : out Sock_Addr_Type); 815 -- Extracts the first connection request on the queue of pending 816 -- connections, creates a new connected socket with mostly the same 817 -- properties as Server, and allocates a new socket. The returned Address 818 -- is filled in with the address of the connection. Raises Socket_Error on 819 -- error. Note: if Server is a non-blocking socket, whether or not this 820 -- aspect is inherited by Socket is platform-dependent. 821 822 procedure Accept_Socket 823 (Server : Socket_Type; 824 Socket : out Socket_Type; 825 Address : out Sock_Addr_Type; 826 Timeout : Selector_Duration; 827 Selector : access Selector_Type := null; 828 Status : out Selector_Status); 829 -- Accept a new connection on Server using Accept_Socket, waiting no longer 830 -- than the given timeout duration. Status is set to indicate whether the 831 -- operation completed successfully, timed out, or was aborted. If Selector 832 -- is not null, the designated selector is used to wait for the socket to 833 -- become available, else a private selector object is created by this 834 -- procedure and destroyed before it returns. 835 836 procedure Bind_Socket 837 (Socket : Socket_Type; 838 Address : Sock_Addr_Type); 839 -- Once a socket is created, assign a local address to it. Raise 840 -- Socket_Error on error. 841 842 procedure Close_Socket (Socket : Socket_Type); 843 -- Close a socket and more specifically a non-connected socket 844 845 procedure Connect_Socket 846 (Socket : Socket_Type; 847 Server : Sock_Addr_Type); 848 -- Make a connection to another socket which has the address of Server. 849 -- Raises Socket_Error on error. 850 851 procedure Connect_Socket 852 (Socket : Socket_Type; 853 Server : Sock_Addr_Type; 854 Timeout : Selector_Duration; 855 Selector : access Selector_Type := null; 856 Status : out Selector_Status); 857 -- Connect Socket to the given Server address using Connect_Socket, waiting 858 -- no longer than the given timeout duration. Status is set to indicate 859 -- whether the operation completed successfully, timed out, or was aborted. 860 -- If Selector is not null, the designated selector is used to wait for the 861 -- socket to become available, else a private selector object is created 862 -- by this procedure and destroyed before it returns. If Timeout is 0.0, 863 -- no attempt is made to detect whether the connection has succeeded; it 864 -- is up to the user to determine this using Check_Selector later on. 865 866 procedure Control_Socket 867 (Socket : Socket_Type; 868 Request : in out Request_Type); 869 -- Obtain or set parameter values that control the socket. This control 870 -- differs from the socket options in that they are not specific to sockets 871 -- but are available for any device. 872 873 function Get_Peer_Name (Socket : Socket_Type) return Sock_Addr_Type; 874 -- Return the peer or remote socket address of a socket. Raise 875 -- Socket_Error on error. 876 877 function Get_Socket_Name (Socket : Socket_Type) return Sock_Addr_Type; 878 -- Return the local or current socket address of a socket. Return 879 -- No_Sock_Addr on error (e.g. socket closed or not locally bound). 880 881 function Get_Socket_Option 882 (Socket : Socket_Type; 883 Level : Level_Type := Socket_Level; 884 Name : Option_Name) return Option_Type; 885 -- Get the options associated with a socket. Raises Socket_Error on error 886 887 procedure Listen_Socket 888 (Socket : Socket_Type; 889 Length : Natural := 15); 890 -- To accept connections, a socket is first created with Create_Socket, 891 -- a willingness to accept incoming connections and a queue Length for 892 -- incoming connections are specified. Raise Socket_Error on error. 893 -- The queue length of 15 is an example value that should be appropriate 894 -- in usual cases. It can be adjusted according to each application's 895 -- particular requirements. 896 897 procedure Receive_Socket 898 (Socket : Socket_Type; 899 Item : out Ada.Streams.Stream_Element_Array; 900 Last : out Ada.Streams.Stream_Element_Offset; 901 Flags : Request_Flag_Type := No_Request_Flag); 902 -- Receive message from Socket. Last is the index value such that Item 903 -- (Last) is the last character assigned. Note that Last is set to 904 -- Item'First - 1 when the socket has been closed by peer. This is not 905 -- an error, and no exception is raised in this case unless Item'First 906 -- is Stream_Element_Offset'First, in which case Constraint_Error is 907 -- raised. Flags allows to control the reception. Raise Socket_Error on 908 -- error. 909 910 procedure Receive_Socket 911 (Socket : Socket_Type; 912 Item : out Ada.Streams.Stream_Element_Array; 913 Last : out Ada.Streams.Stream_Element_Offset; 914 From : out Sock_Addr_Type; 915 Flags : Request_Flag_Type := No_Request_Flag); 916 -- Receive message from Socket. If Socket is not connection-oriented, the 917 -- source address From of the message is filled in. Last is the index 918 -- value such that Item (Last) is the last character assigned. Flags 919 -- allows to control the reception. Raises Socket_Error on error. 920 921 procedure Receive_Vector 922 (Socket : Socket_Type; 923 Vector : Vector_Type; 924 Count : out Ada.Streams.Stream_Element_Count; 925 Flags : Request_Flag_Type := No_Request_Flag); 926 -- Receive data from a socket and scatter it into the set of vector 927 -- elements Vector. Count is set to the count of received stream elements. 928 -- Flags allow control over reception. 929 930 function Resolve_Exception 931 (Occurrence : Ada.Exceptions.Exception_Occurrence) return Error_Type; 932 -- When Socket_Error or Host_Error are raised, the exception message 933 -- contains the error code between brackets and a string describing the 934 -- error code. Resolve_Error extracts the error code from an exception 935 -- message and translate it into an enumeration value. 936 937 procedure Send_Socket 938 (Socket : Socket_Type; 939 Item : Ada.Streams.Stream_Element_Array; 940 Last : out Ada.Streams.Stream_Element_Offset; 941 To : access Sock_Addr_Type; 942 Flags : Request_Flag_Type := No_Request_Flag); 943 pragma Inline (Send_Socket); 944 -- Transmit a message over a socket. For a datagram socket, the address 945 -- is given by To.all. For a stream socket, To must be null. Last 946 -- is the index value such that Item (Last) is the last character 947 -- sent. Note that Last is set to Item'First - 1 if the socket has been 948 -- closed by the peer (unless Item'First is Stream_Element_Offset'First, 949 -- in which case Constraint_Error is raised instead). This is not an error, 950 -- and Socket_Error is not raised in that case. Flags allows control of the 951 -- transmission. Raises exception Socket_Error on error. Note: this 952 -- subprogram is inlined because it is also used to implement the two 953 -- variants below. 954 955 procedure Send_Socket 956 (Socket : Socket_Type; 957 Item : Ada.Streams.Stream_Element_Array; 958 Last : out Ada.Streams.Stream_Element_Offset; 959 Flags : Request_Flag_Type := No_Request_Flag); 960 -- Transmit a message over a socket. Upon return, Last is set to the index 961 -- within Item of the last element transmitted. Flags allows to control 962 -- the transmission. Raises Socket_Error on any detected error condition. 963 964 procedure Send_Socket 965 (Socket : Socket_Type; 966 Item : Ada.Streams.Stream_Element_Array; 967 Last : out Ada.Streams.Stream_Element_Offset; 968 To : Sock_Addr_Type; 969 Flags : Request_Flag_Type := No_Request_Flag); 970 -- Transmit a message over a datagram socket. The destination address is 971 -- To. Flags allows to control the transmission. Raises Socket_Error on 972 -- error. 973 974 procedure Send_Vector 975 (Socket : Socket_Type; 976 Vector : Vector_Type; 977 Count : out Ada.Streams.Stream_Element_Count; 978 Flags : Request_Flag_Type := No_Request_Flag); 979 -- Transmit data gathered from the set of vector elements Vector to a 980 -- socket. Count is set to the count of transmitted stream elements. Flags 981 -- allow control over transmission. 982 983 procedure Set_Close_On_Exec 984 (Socket : Socket_Type; 985 Close_On_Exec : Boolean; 986 Status : out Boolean); 987 -- When Close_On_Exec is True, mark Socket to be closed automatically when 988 -- a new program is executed by the calling process (i.e. prevent Socket 989 -- from being inherited by child processes). When Close_On_Exec is False, 990 -- mark Socket to not be closed on exec (i.e. allow it to be inherited). 991 -- Status is False if the operation could not be performed, or is not 992 -- supported on the target platform. 993 994 procedure Set_Socket_Option 995 (Socket : Socket_Type; 996 Level : Level_Type := Socket_Level; 997 Option : Option_Type); 998 -- Manipulate socket options. Raises Socket_Error on error 999 1000 procedure Shutdown_Socket 1001 (Socket : Socket_Type; 1002 How : Shutmode_Type := Shut_Read_Write); 1003 -- Shutdown a connected socket. If How is Shut_Read further receives will 1004 -- be disallowed. If How is Shut_Write further sends will be disallowed. 1005 -- If How is Shut_Read_Write further sends and receives will be disallowed. 1006 1007 type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class; 1008 -- Same interface as Ada.Streams.Stream_IO 1009 1010 function Stream (Socket : Socket_Type) return Stream_Access; 1011 -- Create a stream associated with an already connected stream-based socket 1012 1013 function Stream 1014 (Socket : Socket_Type; 1015 Send_To : Sock_Addr_Type) return Stream_Access; 1016 -- Create a stream associated with an already bound datagram-based socket. 1017 -- Send_To is the destination address to which messages are being sent. 1018 1019 function Get_Address 1020 (Stream : not null Stream_Access) return Sock_Addr_Type; 1021 -- Return the socket address from which the last message was received 1022 1023 procedure Free is new Ada.Unchecked_Deallocation 1024 (Ada.Streams.Root_Stream_Type'Class, Stream_Access); 1025 -- Destroy a stream created by one of the Stream functions above, releasing 1026 -- the corresponding resources. The user is responsible for calling this 1027 -- subprogram when the stream is not needed anymore. 1028 1029 type Socket_Set_Type is limited private; 1030 -- This type allows to manipulate sets of sockets. It allows to wait for 1031 -- events on multiple endpoints at one time. This type has default 1032 -- initialization, and the default value is the empty set. 1033 -- 1034 -- Note: This type used to contain a pointer to dynamically allocated 1035 -- storage, but this is not the case anymore, and no special precautions 1036 -- are required to avoid memory leaks. 1037 1038 procedure Clear (Item : in out Socket_Set_Type; Socket : Socket_Type); 1039 -- Remove Socket from Item 1040 1041 procedure Copy (Source : Socket_Set_Type; Target : out Socket_Set_Type); 1042 -- Copy Source into Target as Socket_Set_Type is limited private 1043 1044 procedure Empty (Item : out Socket_Set_Type); 1045 -- Remove all Sockets from Item 1046 1047 procedure Get (Item : in out Socket_Set_Type; Socket : out Socket_Type); 1048 -- Extract a Socket from socket set Item. Socket is set to 1049 -- No_Socket when the set is empty. 1050 1051 function Is_Empty (Item : Socket_Set_Type) return Boolean; 1052 -- Return True iff Item is empty 1053 1054 function Is_Set 1055 (Item : Socket_Set_Type; 1056 Socket : Socket_Type) return Boolean; 1057 -- Return True iff Socket is present in Item 1058 1059 procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type); 1060 -- Insert Socket into Item 1061 1062 function Image (Item : Socket_Set_Type) return String; 1063 -- Return a printable image of Item, for debugging purposes 1064 1065 -- The select(2) system call waits for events to occur on any of a set of 1066 -- file descriptors. Usually, three independent sets of descriptors are 1067 -- watched (read, write and exception). A timeout gives an upper bound 1068 -- on the amount of time elapsed before select returns. This function 1069 -- blocks until an event occurs. On some platforms, the select(2) system 1070 -- can block the full process (not just the calling thread). 1071 -- 1072 -- Check_Selector provides the very same behaviour. The only difference is 1073 -- that it does not watch for exception events. Note that on some platforms 1074 -- it is kept process blocking on purpose. The timeout parameter allows the 1075 -- user to have the behaviour he wants. Abort_Selector allows to safely 1076 -- abort a blocked Check_Selector call. A special socket is opened by 1077 -- Create_Selector and included in each call to Check_Selector. 1078 -- 1079 -- Abort_Selector causes an event to occur on this descriptor in order to 1080 -- unblock Check_Selector. Note that each call to Abort_Selector will cause 1081 -- exactly one call to Check_Selector to return with Aborted status. The 1082 -- special socket created by Create_Selector is closed when Close_Selector 1083 -- is called. 1084 -- 1085 -- A typical case where it is useful to abort a Check_Selector operation is 1086 -- the situation where a change to the monitored sockets set must be made. 1087 1088 procedure Create_Selector (Selector : out Selector_Type); 1089 -- Initialize (open) a new selector 1090 1091 procedure Close_Selector (Selector : in out Selector_Type); 1092 -- Close Selector and all internal descriptors associated; deallocate any 1093 -- associated resources. This subprogram may be called only when there is 1094 -- no other task still using Selector (i.e. still executing Check_Selector 1095 -- or Abort_Selector on this Selector). Has no effect if Selector is 1096 -- already closed. 1097 1098 procedure Check_Selector 1099 (Selector : Selector_Type; 1100 R_Socket_Set : in out Socket_Set_Type; 1101 W_Socket_Set : in out Socket_Set_Type; 1102 Status : out Selector_Status; 1103 Timeout : Selector_Duration := Forever); 1104 -- Return when one Socket in R_Socket_Set has some data to be read or if 1105 -- one Socket in W_Socket_Set is ready to transmit some data. In these 1106 -- cases Status is set to Completed and sockets that are ready are set in 1107 -- R_Socket_Set or W_Socket_Set. Status is set to Expired if no socket was 1108 -- ready after a Timeout expiration. Status is set to Aborted if an abort 1109 -- signal has been received while checking socket status. 1110 -- 1111 -- Note that two different Socket_Set_Type objects must be passed as 1112 -- R_Socket_Set and W_Socket_Set (even if they denote the same set of 1113 -- Sockets), or some event may be lost. 1114 -- 1115 -- Socket_Error is raised when the select(2) system call returns an error 1116 -- condition, or when a read error occurs on the signalling socket used for 1117 -- the implementation of Abort_Selector. 1118 1119 procedure Check_Selector 1120 (Selector : Selector_Type; 1121 R_Socket_Set : in out Socket_Set_Type; 1122 W_Socket_Set : in out Socket_Set_Type; 1123 E_Socket_Set : in out Socket_Set_Type; 1124 Status : out Selector_Status; 1125 Timeout : Selector_Duration := Forever); 1126 -- This refined version of Check_Selector allows watching for exception 1127 -- events (i.e. notifications of out-of-band transmission and reception). 1128 -- As above, all of R_Socket_Set, W_Socket_Set and E_Socket_Set must be 1129 -- different objects. 1130 1131 procedure Abort_Selector (Selector : Selector_Type); 1132 -- Send an abort signal to the selector. The Selector may not be the 1133 -- Null_Selector. 1134 1135 type Fd_Set is private; 1136 -- ??? This type must not be used directly, it needs to be visible because 1137 -- it is used in the visible part of GNAT.Sockets.Thin_Common. This is 1138 -- really an inversion of abstraction. The private part of GNAT.Sockets 1139 -- needs to have visibility on this type, but since Thin_Common is a child 1140 -- of Sockets, the type can't be declared there. The correct fix would 1141 -- be to move the thin sockets binding outside of GNAT.Sockets altogether, 1142 -- e.g. by renaming it to GNAT.Sockets_Thin. 1143 1144private 1145 1146 type Socket_Type is new Integer; 1147 No_Socket : constant Socket_Type := -1; 1148 1149 -- A selector is either a null selector, which is always "open" and can 1150 -- never be aborted, or a regular selector, which is created "closed", 1151 -- becomes "open" when Create_Selector is called, and "closed" again when 1152 -- Close_Selector is called. 1153 1154 type Selector_Type (Is_Null : Boolean := False) is limited record 1155 case Is_Null is 1156 when True => 1157 null; 1158 1159 when False => 1160 R_Sig_Socket : Socket_Type := No_Socket; 1161 W_Sig_Socket : Socket_Type := No_Socket; 1162 -- Signalling sockets used to abort a select operation 1163 end case; 1164 end record; 1165 1166 pragma Volatile (Selector_Type); 1167 1168 Null_Selector : constant Selector_Type := (Is_Null => True); 1169 1170 type Fd_Set is 1171 new System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_fd_set); 1172 for Fd_Set'Alignment use Interfaces.C.long'Alignment; 1173 -- Set conservative alignment so that our Fd_Sets are always adequately 1174 -- aligned for the underlying data type (which is implementation defined 1175 -- and may be an array of C long integers). 1176 1177 type Fd_Set_Access is access all Fd_Set; 1178 pragma Convention (C, Fd_Set_Access); 1179 No_Fd_Set_Access : constant Fd_Set_Access := null; 1180 1181 type Socket_Set_Type is record 1182 Last : Socket_Type := No_Socket; 1183 -- Highest socket in set. Last = No_Socket denotes an empty set (which 1184 -- is the default initial value). 1185 1186 Set : aliased Fd_Set; 1187 -- Underlying socket set. Note that the contents of this component is 1188 -- undefined if Last = No_Socket. 1189 end record; 1190 1191 subtype Inet_Addr_Comp_Type is Natural range 0 .. 255; 1192 -- Octet for Internet address 1193 1194 type Inet_Addr_VN_Type is array (Natural range <>) of Inet_Addr_Comp_Type; 1195 1196 subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 .. 4); 1197 subtype Inet_Addr_V6_Type is Inet_Addr_VN_Type (1 .. 16); 1198 1199 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is record 1200 case Family is 1201 when Family_Inet => 1202 Sin_V4 : Inet_Addr_V4_Type := (others => 0); 1203 1204 when Family_Inet6 => 1205 Sin_V6 : Inet_Addr_V6_Type := (others => 0); 1206 end case; 1207 end record; 1208 1209 Any_Port : constant Port_Type := 0; 1210 No_Port : constant Port_Type := 0; 1211 1212 Any_Inet_Addr : constant Inet_Addr_Type := 1213 (Family_Inet, (others => 0)); 1214 No_Inet_Addr : constant Inet_Addr_Type := 1215 (Family_Inet, (others => 0)); 1216 Broadcast_Inet_Addr : constant Inet_Addr_Type := 1217 (Family_Inet, (others => 255)); 1218 Loopback_Inet_Addr : constant Inet_Addr_Type := 1219 (Family_Inet, (127, 0, 0, 1)); 1220 1221 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type := 1222 (Family_Inet, (224, 0, 0, 0)); 1223 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type := 1224 (Family_Inet, (224, 0, 0, 1)); 1225 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type := 1226 (Family_Inet, (224, 0, 0, 2)); 1227 1228 No_Sock_Addr : constant Sock_Addr_Type := (Family_Inet, No_Inet_Addr, 0); 1229 1230 Max_Name_Length : constant := 64; 1231 -- The constant MAXHOSTNAMELEN is usually set to 64 1232 1233 subtype Name_Index is Natural range 1 .. Max_Name_Length; 1234 1235 type Name_Type (Length : Name_Index := Max_Name_Length) is record 1236 Name : String (1 .. Length); 1237 end record; 1238 -- We need fixed strings to avoid access types in host entry type 1239 1240 type Name_Array is array (Natural range <>) of Name_Type; 1241 type Inet_Addr_Array is array (Natural range <>) of Inet_Addr_Type; 1242 1243 type Host_Entry_Type (Aliases_Length, Addresses_Length : Natural) is record 1244 Official : Name_Type; 1245 Aliases : Name_Array (1 .. Aliases_Length); 1246 Addresses : Inet_Addr_Array (1 .. Addresses_Length); 1247 end record; 1248 1249 type Service_Entry_Type (Aliases_Length : Natural) is record 1250 Official : Name_Type; 1251 Aliases : Name_Array (1 .. Aliases_Length); 1252 Port : Port_Type; 1253 Protocol : Name_Type; 1254 end record; 1255 1256 type Request_Flag_Type is mod 2 ** 8; 1257 No_Request_Flag : constant Request_Flag_Type := 0; 1258 Process_Out_Of_Band_Data : constant Request_Flag_Type := 1; 1259 Peek_At_Incoming_Data : constant Request_Flag_Type := 2; 1260 Wait_For_A_Full_Reception : constant Request_Flag_Type := 4; 1261 Send_End_Of_Record : constant Request_Flag_Type := 8; 1262 1263end GNAT.Sockets; 1264