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) 2001-2018, 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 use type Interfaces.C.int; 377 -- Need visibility on "-" operator so that we can write -1 378 379 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_Ada (Fd : Integer) return Socket_Type with Inline; 460 -- Convert a file descriptor to Socket_Type. This is useful when a socket 461 -- file descriptor is obtained from an external library call. 462 463 function To_C (Socket : Socket_Type) return Integer with Inline; 464 -- Return a file descriptor to be used by external subprograms. This is 465 -- useful for C functions that are not yet interfaced in this package. 466 467 type Family_Type is (Family_Inet, Family_Inet6); 468 -- Address family (or protocol family) identifies the communication domain 469 -- and groups protocols with similar address formats. 470 471 type Mode_Type is (Socket_Stream, Socket_Datagram); 472 -- Stream sockets provide connection-oriented byte streams. Datagram 473 -- sockets support unreliable connectionless message based communication. 474 475 type Shutmode_Type is (Shut_Read, Shut_Write, Shut_Read_Write); 476 -- When a process closes a socket, the policy is to retain any data queued 477 -- until either a delivery or a timeout expiration (in this case, the data 478 -- are discarded). A finer control is available through shutdown. With 479 -- Shut_Read, no more data can be received from the socket. With_Write, no 480 -- more data can be transmitted. Neither transmission nor reception can be 481 -- performed with Shut_Read_Write. 482 483 type Port_Type is range 0 .. 16#ffff#; 484 -- TCP/UDP port number 485 486 Any_Port : constant Port_Type; 487 -- All ports 488 489 No_Port : constant Port_Type; 490 -- Uninitialized port number 491 492 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is private; 493 -- An Internet address depends on an address family (IPv4 contains 4 octets 494 -- and IPv6 contains 16 octets). Any_Inet_Addr is a special value treated 495 -- like a wildcard enabling all addresses. No_Inet_Addr provides a special 496 -- value to denote uninitialized inet addresses. 497 498 Any_Inet_Addr : constant Inet_Addr_Type; 499 No_Inet_Addr : constant Inet_Addr_Type; 500 Broadcast_Inet_Addr : constant Inet_Addr_Type; 501 Loopback_Inet_Addr : constant Inet_Addr_Type; 502 503 -- Useful constants for IPv4 multicast addresses 504 505 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type; 506 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type; 507 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type; 508 509 type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record 510 Addr : Inet_Addr_Type (Family); 511 Port : Port_Type; 512 end record; 513 pragma No_Component_Reordering (Sock_Addr_Type); 514 -- Socket addresses fully define a socket connection with protocol family, 515 -- an Internet address and a port. No_Sock_Addr provides a special value 516 -- for uninitialized socket addresses. 517 518 No_Sock_Addr : constant Sock_Addr_Type; 519 520 function Image (Value : Inet_Addr_Type) return String; 521 -- Return an image of an Internet address. IPv4 notation consists in 4 522 -- octets in decimal format separated by dots. IPv6 notation consists in 523 -- 16 octets in hexadecimal format separated by colons (and possibly 524 -- dots). 525 526 function Image (Value : Sock_Addr_Type) return String; 527 -- Return inet address image and port image separated by a colon 528 529 function Inet_Addr (Image : String) return Inet_Addr_Type; 530 -- Convert address image from numbers-and-dots notation into an 531 -- inet address. 532 533 -- Host entries provide complete information on a given host: the official 534 -- name, an array of alternative names or aliases and array of network 535 -- addresses. 536 537 type Host_Entry_Type 538 (Aliases_Length, Addresses_Length : Natural) is private; 539 540 function Official_Name (E : Host_Entry_Type) return String; 541 -- Return official name in host entry 542 543 function Aliases_Length (E : Host_Entry_Type) return Natural; 544 -- Return number of aliases in host entry 545 546 function Addresses_Length (E : Host_Entry_Type) return Natural; 547 -- Return number of addresses in host entry 548 549 function Aliases 550 (E : Host_Entry_Type; 551 N : Positive := 1) return String; 552 -- Return N'th aliases in host entry. The first index is 1 553 554 function Addresses 555 (E : Host_Entry_Type; 556 N : Positive := 1) return Inet_Addr_Type; 557 -- Return N'th addresses in host entry. The first index is 1 558 559 Host_Error : exception; 560 -- Exception raised by the two following procedures. Once raised, its 561 -- message contains a string describing the error code. This exception is 562 -- raised when an host entry cannot be retrieved. 563 564 function Get_Host_By_Address 565 (Address : Inet_Addr_Type; 566 Family : Family_Type := Family_Inet) return Host_Entry_Type; 567 -- Return host entry structure for the given Inet address. Note that no 568 -- result will be returned if there is no mapping of this IP address to a 569 -- host name in the system tables (host database, DNS or otherwise). 570 571 function Get_Host_By_Name 572 (Name : String) return Host_Entry_Type; 573 -- Return host entry structure for the given host name. Here name is 574 -- either a host name, or an IP address. If Name is an IP address, this 575 -- is equivalent to Get_Host_By_Address (Inet_Addr (Name)). 576 577 function Host_Name return String; 578 -- Return the name of the current host 579 580 type Service_Entry_Type (Aliases_Length : Natural) is private; 581 -- Service entries provide complete information on a given service: the 582 -- official name, an array of alternative names or aliases and the port 583 -- number. 584 585 function Official_Name (S : Service_Entry_Type) return String; 586 -- Return official name in service entry 587 588 function Port_Number (S : Service_Entry_Type) return Port_Type; 589 -- Return port number in service entry 590 591 function Protocol_Name (S : Service_Entry_Type) return String; 592 -- Return Protocol in service entry (usually UDP or TCP) 593 594 function Aliases_Length (S : Service_Entry_Type) return Natural; 595 -- Return number of aliases in service entry 596 597 function Aliases 598 (S : Service_Entry_Type; 599 N : Positive := 1) return String; 600 -- Return N'th aliases in service entry (the first index is 1) 601 602 function Get_Service_By_Name 603 (Name : String; 604 Protocol : String) return Service_Entry_Type; 605 -- Return service entry structure for the given service name 606 607 function Get_Service_By_Port 608 (Port : Port_Type; 609 Protocol : String) return Service_Entry_Type; 610 -- Return service entry structure for the given service port number 611 612 Service_Error : exception; 613 -- Comment required ??? 614 615 -- Errors are described by an enumeration type. There is only one exception 616 -- Socket_Error in this package to deal with an error during a socket 617 -- routine. Once raised, its message contains the error code between 618 -- brackets and a string describing the error code. 619 620 -- The name of the enumeration constant documents the error condition 621 -- Note that on some platforms, a single error value is used for both 622 -- EWOULDBLOCK and EAGAIN. Both errors are therefore always reported as 623 -- Resource_Temporarily_Unavailable. 624 625 type Error_Type is 626 (Success, 627 Permission_Denied, 628 Address_Already_In_Use, 629 Cannot_Assign_Requested_Address, 630 Address_Family_Not_Supported_By_Protocol, 631 Operation_Already_In_Progress, 632 Bad_File_Descriptor, 633 Software_Caused_Connection_Abort, 634 Connection_Refused, 635 Connection_Reset_By_Peer, 636 Destination_Address_Required, 637 Bad_Address, 638 Host_Is_Down, 639 No_Route_To_Host, 640 Operation_Now_In_Progress, 641 Interrupted_System_Call, 642 Invalid_Argument, 643 Input_Output_Error, 644 Transport_Endpoint_Already_Connected, 645 Too_Many_Symbolic_Links, 646 Too_Many_Open_Files, 647 Message_Too_Long, 648 File_Name_Too_Long, 649 Network_Is_Down, 650 Network_Dropped_Connection_Because_Of_Reset, 651 Network_Is_Unreachable, 652 No_Buffer_Space_Available, 653 Protocol_Not_Available, 654 Transport_Endpoint_Not_Connected, 655 Socket_Operation_On_Non_Socket, 656 Operation_Not_Supported, 657 Protocol_Family_Not_Supported, 658 Protocol_Not_Supported, 659 Protocol_Wrong_Type_For_Socket, 660 Cannot_Send_After_Transport_Endpoint_Shutdown, 661 Socket_Type_Not_Supported, 662 Connection_Timed_Out, 663 Too_Many_References, 664 Resource_Temporarily_Unavailable, 665 Broken_Pipe, 666 Unknown_Host, 667 Host_Name_Lookup_Failure, 668 Non_Recoverable_Error, 669 Unknown_Server_Error, 670 Cannot_Resolve_Error); 671 672 -- Get_Socket_Options and Set_Socket_Options manipulate options associated 673 -- with a socket. Options may exist at multiple protocol levels in the 674 -- communication stack. Socket_Level is the uppermost socket level. 675 676 type Level_Type is 677 (Socket_Level, 678 IP_Protocol_For_IP_Level, 679 IP_Protocol_For_UDP_Level, 680 IP_Protocol_For_TCP_Level); 681 682 -- There are several options available to manipulate sockets. Each option 683 -- has a name and several values available. Most of the time, the value is 684 -- a boolean to enable or disable this option. 685 686 type Option_Name is 687 (Generic_Option, 688 Keep_Alive, -- Enable sending of keep-alive messages 689 Reuse_Address, -- Allow bind to reuse local address 690 Broadcast, -- Enable datagram sockets to recv/send broadcasts 691 Send_Buffer, -- Set/get the maximum socket send buffer in bytes 692 Receive_Buffer, -- Set/get the maximum socket recv buffer in bytes 693 Linger, -- Shutdown wait for msg to be sent or timeout occur 694 Error, -- Get and clear the pending socket error 695 No_Delay, -- Do not delay send to coalesce data (TCP_NODELAY) 696 Add_Membership, -- Join a multicast group 697 Drop_Membership, -- Leave a multicast group 698 Multicast_If, -- Set default out interface for multicast packets 699 Multicast_TTL, -- Set the time-to-live of sent multicast packets 700 Multicast_Loop, -- Sent multicast packets are looped to local socket 701 Receive_Packet_Info, -- Receive low level packet info as ancillary data 702 Send_Timeout, -- Set timeout value for output 703 Receive_Timeout, -- Set timeout value for input 704 Busy_Polling); -- Set busy polling mode 705 subtype Specific_Option_Name is 706 Option_Name range Keep_Alive .. Option_Name'Last; 707 708 type Option_Type (Name : Option_Name := Keep_Alive) is record 709 case Name is 710 when Generic_Option => 711 Optname : Interfaces.C.int := -1; 712 Optval : Interfaces.C.int; 713 714 when Keep_Alive | 715 Reuse_Address | 716 Broadcast | 717 Linger | 718 No_Delay | 719 Receive_Packet_Info | 720 Multicast_Loop => 721 Enabled : Boolean; 722 723 case Name is 724 when Linger => 725 Seconds : Natural; 726 when others => 727 null; 728 end case; 729 730 when Busy_Polling => 731 Microseconds : Natural; 732 733 when Send_Buffer | 734 Receive_Buffer => 735 Size : Natural; 736 737 when Error => 738 Error : Error_Type; 739 740 when Add_Membership | 741 Drop_Membership => 742 Multicast_Address : Inet_Addr_Type; 743 Local_Interface : Inet_Addr_Type; 744 745 when Multicast_If => 746 Outgoing_If : Inet_Addr_Type; 747 748 when Multicast_TTL => 749 Time_To_Live : Natural; 750 751 when Send_Timeout | 752 Receive_Timeout => 753 Timeout : Timeval_Duration; 754 755 end case; 756 end record; 757 758 -- There are several controls available to manipulate sockets. Each option 759 -- has a name and several values available. These controls differ from the 760 -- socket options in that they are not specific to sockets but are 761 -- available for any device. 762 763 type Request_Name is 764 (Non_Blocking_IO, -- Cause a caller not to wait on blocking operations 765 N_Bytes_To_Read); -- Return the number of bytes available to read 766 767 type Request_Type (Name : Request_Name := Non_Blocking_IO) is record 768 case Name is 769 when Non_Blocking_IO => 770 Enabled : Boolean; 771 772 when N_Bytes_To_Read => 773 Size : Natural; 774 775 end case; 776 end record; 777 778 -- A request flag allows specification of the type of message transmissions 779 -- or receptions. A request flag can be combination of zero or more 780 -- predefined request flags. 781 782 type Request_Flag_Type is private; 783 784 No_Request_Flag : constant Request_Flag_Type; 785 -- This flag corresponds to the normal execution of an operation 786 787 Process_Out_Of_Band_Data : constant Request_Flag_Type; 788 -- This flag requests that the receive or send function operates on 789 -- out-of-band data when the socket supports this notion (e.g. 790 -- Socket_Stream). 791 792 Peek_At_Incoming_Data : constant Request_Flag_Type; 793 -- This flag causes the receive operation to return data from the beginning 794 -- of the receive queue without removing that data from the queue. A 795 -- subsequent receive call will return the same data. 796 797 Wait_For_A_Full_Reception : constant Request_Flag_Type; 798 -- This flag requests that the operation block until the full request is 799 -- satisfied. However, the call may still return less data than requested 800 -- if a signal is caught, an error or disconnect occurs, or the next data 801 -- to be received is of a different type than that returned. Note that 802 -- this flag depends on support in the underlying sockets implementation, 803 -- and is not supported under Windows. 804 805 Send_End_Of_Record : constant Request_Flag_Type; 806 -- This flag indicates that the entire message has been sent and so this 807 -- terminates the record. 808 809 function "+" (L, R : Request_Flag_Type) return Request_Flag_Type; 810 -- Combine flag L with flag R 811 812 type Stream_Element_Reference is access all Ada.Streams.Stream_Element; 813 814 type Vector_Element is record 815 Base : Stream_Element_Reference; 816 Length : Interfaces.C.size_t; 817 end record; 818 819 type Vector_Type is array (Integer range <>) of Vector_Element; 820 821 procedure Create_Socket 822 (Socket : out Socket_Type; 823 Family : Family_Type := Family_Inet; 824 Mode : Mode_Type := Socket_Stream); 825 -- Create an endpoint for communication. Raises Socket_Error on error 826 827 procedure Accept_Socket 828 (Server : Socket_Type; 829 Socket : out Socket_Type; 830 Address : out Sock_Addr_Type); 831 -- Extracts the first connection request on the queue of pending 832 -- connections, creates a new connected socket with mostly the same 833 -- properties as Server, and allocates a new socket. The returned Address 834 -- is filled in with the address of the connection. Raises Socket_Error on 835 -- error. Note: if Server is a non-blocking socket, whether or not this 836 -- aspect is inherited by Socket is platform-dependent. 837 838 procedure Accept_Socket 839 (Server : Socket_Type; 840 Socket : out Socket_Type; 841 Address : out Sock_Addr_Type; 842 Timeout : Selector_Duration; 843 Selector : access Selector_Type := null; 844 Status : out Selector_Status); 845 -- Accept a new connection on Server using Accept_Socket, waiting no longer 846 -- than the given timeout duration. Status is set to indicate whether the 847 -- operation completed successfully, timed out, or was aborted. If Selector 848 -- is not null, the designated selector is used to wait for the socket to 849 -- become available, else a private selector object is created by this 850 -- procedure and destroyed before it returns. 851 852 procedure Bind_Socket 853 (Socket : Socket_Type; 854 Address : Sock_Addr_Type); 855 -- Once a socket is created, assign a local address to it. Raise 856 -- Socket_Error on error. 857 858 procedure Close_Socket (Socket : Socket_Type); 859 -- Close a socket and more specifically a non-connected socket 860 861 procedure Connect_Socket 862 (Socket : Socket_Type; 863 Server : Sock_Addr_Type); 864 -- Make a connection to another socket which has the address of Server. 865 -- Raises Socket_Error on error. 866 867 procedure Connect_Socket 868 (Socket : Socket_Type; 869 Server : Sock_Addr_Type; 870 Timeout : Selector_Duration; 871 Selector : access Selector_Type := null; 872 Status : out Selector_Status); 873 -- Connect Socket to the given Server address using Connect_Socket, waiting 874 -- no longer than the given timeout duration. Status is set to indicate 875 -- whether the operation completed successfully, timed out, or was aborted. 876 -- If Selector is not null, the designated selector is used to wait for the 877 -- socket to become available, else a private selector object is created 878 -- by this procedure and destroyed before it returns. If Timeout is 0.0, 879 -- no attempt is made to detect whether the connection has succeeded; it 880 -- is up to the user to determine this using Check_Selector later on. 881 882 procedure Control_Socket 883 (Socket : Socket_Type; 884 Request : in out Request_Type); 885 -- Obtain or set parameter values that control the socket. This control 886 -- differs from the socket options in that they are not specific to sockets 887 -- but are available for any device. 888 889 function Get_Peer_Name (Socket : Socket_Type) return Sock_Addr_Type; 890 -- Return the peer or remote socket address of a socket. Raise 891 -- Socket_Error on error. 892 893 function Get_Socket_Name (Socket : Socket_Type) return Sock_Addr_Type; 894 -- Return the local or current socket address of a socket. Return 895 -- No_Sock_Addr on error (e.g. socket closed or not locally bound). 896 897 function Get_Socket_Option 898 (Socket : Socket_Type; 899 Level : Level_Type := Socket_Level; 900 Name : Option_Name; 901 Optname : Interfaces.C.int := -1) return Option_Type; 902 -- Get the options associated with a socket. Raises Socket_Error on error. 903 -- Optname identifies specific option when Name is Generic_Option. 904 905 procedure Listen_Socket 906 (Socket : Socket_Type; 907 Length : Natural := 15); 908 -- To accept connections, a socket is first created with Create_Socket, 909 -- a willingness to accept incoming connections and a queue Length for 910 -- incoming connections are specified. Raise Socket_Error on error. 911 -- The queue length of 15 is an example value that should be appropriate 912 -- in usual cases. It can be adjusted according to each application's 913 -- particular requirements. 914 915 procedure Receive_Socket 916 (Socket : Socket_Type; 917 Item : out Ada.Streams.Stream_Element_Array; 918 Last : out Ada.Streams.Stream_Element_Offset; 919 Flags : Request_Flag_Type := No_Request_Flag); 920 -- Receive message from Socket. Last is the index value such that Item 921 -- (Last) is the last character assigned. Note that Last is set to 922 -- Item'First - 1 when the socket has been closed by peer. This is not 923 -- an error, and no exception is raised in this case unless Item'First 924 -- is Stream_Element_Offset'First, in which case Constraint_Error is 925 -- raised. Flags allows control of the reception. Raise Socket_Error on 926 -- error. 927 928 procedure Receive_Socket 929 (Socket : Socket_Type; 930 Item : out Ada.Streams.Stream_Element_Array; 931 Last : out Ada.Streams.Stream_Element_Offset; 932 From : out Sock_Addr_Type; 933 Flags : Request_Flag_Type := No_Request_Flag); 934 -- Receive message from Socket. If Socket is not connection-oriented, the 935 -- source address From of the message is filled in. Last is the index 936 -- value such that Item (Last) is the last character assigned. Flags 937 -- allows control of the reception. Raises Socket_Error on error. 938 939 procedure Receive_Vector 940 (Socket : Socket_Type; 941 Vector : Vector_Type; 942 Count : out Ada.Streams.Stream_Element_Count; 943 Flags : Request_Flag_Type := No_Request_Flag); 944 -- Receive data from a socket and scatter it into the set of vector 945 -- elements Vector. Count is set to the count of received stream elements. 946 -- Flags allow control over reception. 947 948 function Resolve_Exception 949 (Occurrence : Ada.Exceptions.Exception_Occurrence) return Error_Type; 950 -- When Socket_Error or Host_Error are raised, the exception message 951 -- contains the error code between brackets and a string describing the 952 -- error code. Resolve_Error extracts the error code from an exception 953 -- message and translate it into an enumeration value. 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 To : access Sock_Addr_Type; 960 Flags : Request_Flag_Type := No_Request_Flag); 961 pragma Inline (Send_Socket); 962 -- Transmit a message over a socket. For a datagram socket, the address 963 -- is given by To.all. For a stream socket, To must be null. Last 964 -- is the index value such that Item (Last) is the last character 965 -- sent. Note that Last is set to Item'First - 1 if the socket has been 966 -- closed by the peer (unless Item'First is Stream_Element_Offset'First, 967 -- in which case Constraint_Error is raised instead). This is not an error, 968 -- and Socket_Error is not raised in that case. Flags allows control of the 969 -- transmission. Raises exception Socket_Error on error. Note: this 970 -- subprogram is inlined because it is also used to implement the two 971 -- variants below. 972 973 procedure Send_Socket 974 (Socket : Socket_Type; 975 Item : Ada.Streams.Stream_Element_Array; 976 Last : out Ada.Streams.Stream_Element_Offset; 977 Flags : Request_Flag_Type := No_Request_Flag); 978 -- Transmit a message over a socket. Upon return, Last is set to the index 979 -- within Item of the last element transmitted. Flags allows control of 980 -- the transmission. Raises Socket_Error on any detected error condition. 981 982 procedure Send_Socket 983 (Socket : Socket_Type; 984 Item : Ada.Streams.Stream_Element_Array; 985 Last : out Ada.Streams.Stream_Element_Offset; 986 To : Sock_Addr_Type; 987 Flags : Request_Flag_Type := No_Request_Flag); 988 -- Transmit a message over a datagram socket. The destination address is 989 -- To. Flags allows control of the transmission. Raises Socket_Error on 990 -- error. 991 992 procedure Send_Vector 993 (Socket : Socket_Type; 994 Vector : Vector_Type; 995 Count : out Ada.Streams.Stream_Element_Count; 996 Flags : Request_Flag_Type := No_Request_Flag); 997 -- Transmit data gathered from the set of vector elements Vector to a 998 -- socket. Count is set to the count of transmitted stream elements. Flags 999 -- allow control over transmission. 1000 1001 procedure Set_Close_On_Exec 1002 (Socket : Socket_Type; 1003 Close_On_Exec : Boolean; 1004 Status : out Boolean); 1005 -- When Close_On_Exec is True, mark Socket to be closed automatically when 1006 -- a new program is executed by the calling process (i.e. prevent Socket 1007 -- from being inherited by child processes). When Close_On_Exec is False, 1008 -- mark Socket to not be closed on exec (i.e. allow it to be inherited). 1009 -- Status is False if the operation could not be performed, or is not 1010 -- supported on the target platform. 1011 1012 procedure Set_Socket_Option 1013 (Socket : Socket_Type; 1014 Level : Level_Type := Socket_Level; 1015 Option : Option_Type); 1016 -- Manipulate socket options. Raises Socket_Error on error 1017 1018 procedure Shutdown_Socket 1019 (Socket : Socket_Type; 1020 How : Shutmode_Type := Shut_Read_Write); 1021 -- Shutdown a connected socket. If How is Shut_Read further receives will 1022 -- be disallowed. If How is Shut_Write further sends will be disallowed. 1023 -- If How is Shut_Read_Write further sends and receives will be disallowed. 1024 1025 type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class; 1026 -- Same interface as Ada.Streams.Stream_IO 1027 1028 function Stream (Socket : Socket_Type) return Stream_Access; 1029 -- Create a stream associated with a connected stream-based socket. 1030 -- Note: keep in mind that the default stream attributes for composite 1031 -- types perform separate Read/Write operations for each component, 1032 -- recursively. If performance is an issue, you may want to consider 1033 -- introducing a buffering stage. 1034 1035 function Stream 1036 (Socket : Socket_Type; 1037 Send_To : Sock_Addr_Type) return Stream_Access; 1038 -- Create a stream associated with an already bound datagram-based socket. 1039 -- Send_To is the destination address to which messages are being sent. 1040 1041 function Get_Address 1042 (Stream : not null Stream_Access) return Sock_Addr_Type; 1043 -- Return the socket address from which the last message was received 1044 1045 procedure Free is new Ada.Unchecked_Deallocation 1046 (Ada.Streams.Root_Stream_Type'Class, Stream_Access); 1047 -- Destroy a stream created by one of the Stream functions above, releasing 1048 -- the corresponding resources. The user is responsible for calling this 1049 -- subprogram when the stream is not needed anymore. 1050 1051 type Socket_Set_Type is limited private; 1052 -- This type allows manipulation of sets of sockets. It allows waiting 1053 -- for events on multiple endpoints at one time. This type has default 1054 -- initialization, and the default value is the empty set. 1055 -- 1056 -- Note: This type used to contain a pointer to dynamically allocated 1057 -- storage, but this is not the case anymore, and no special precautions 1058 -- are required to avoid memory leaks. 1059 1060 procedure Clear (Item : in out Socket_Set_Type; Socket : Socket_Type); 1061 -- Remove Socket from Item 1062 1063 procedure Copy (Source : Socket_Set_Type; Target : out Socket_Set_Type); 1064 -- Copy Source into Target as Socket_Set_Type is limited private 1065 1066 procedure Empty (Item : out Socket_Set_Type); 1067 -- Remove all Sockets from Item 1068 1069 procedure Get (Item : in out Socket_Set_Type; Socket : out Socket_Type); 1070 -- Extract a Socket from socket set Item. Socket is set to 1071 -- No_Socket when the set is empty. 1072 1073 function Is_Empty (Item : Socket_Set_Type) return Boolean; 1074 -- Return True iff Item is empty 1075 1076 function Is_Set 1077 (Item : Socket_Set_Type; 1078 Socket : Socket_Type) return Boolean; 1079 -- Return True iff Socket is present in Item 1080 1081 procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type); 1082 -- Insert Socket into Item 1083 1084 function Image (Item : Socket_Set_Type) return String; 1085 -- Return a printable image of Item, for debugging purposes 1086 1087 -- The select(2) system call waits for events to occur on any of a set of 1088 -- file descriptors. Usually, three independent sets of descriptors are 1089 -- watched (read, write and exception). A timeout gives an upper bound 1090 -- on the amount of time elapsed before select returns. This function 1091 -- blocks until an event occurs. On some platforms, the select(2) system 1092 -- can block the full process (not just the calling thread). 1093 -- 1094 -- Check_Selector provides the very same behavior. The only difference is 1095 -- that it does not watch for exception events. Note that on some platforms 1096 -- it is kept process blocking on purpose. The timeout parameter allows the 1097 -- user to have the behavior he wants. Abort_Selector allows the safe 1098 -- abort of a blocked Check_Selector call. A special socket is opened by 1099 -- Create_Selector and included in each call to Check_Selector. 1100 -- 1101 -- Abort_Selector causes an event to occur on this descriptor in order to 1102 -- unblock Check_Selector. Note that each call to Abort_Selector will cause 1103 -- exactly one call to Check_Selector to return with Aborted status. The 1104 -- special socket created by Create_Selector is closed when Close_Selector 1105 -- is called. 1106 -- 1107 -- A typical case where it is useful to abort a Check_Selector operation is 1108 -- the situation where a change to the monitored sockets set must be made. 1109 1110 procedure Create_Selector (Selector : out Selector_Type); 1111 -- Initialize (open) a new selector 1112 1113 procedure Close_Selector (Selector : in out Selector_Type); 1114 -- Close Selector and all internal descriptors associated; deallocate any 1115 -- associated resources. This subprogram may be called only when there is 1116 -- no other task still using Selector (i.e. still executing Check_Selector 1117 -- or Abort_Selector on this Selector). Has no effect if Selector is 1118 -- already closed. 1119 1120 procedure Check_Selector 1121 (Selector : Selector_Type; 1122 R_Socket_Set : in out Socket_Set_Type; 1123 W_Socket_Set : in out Socket_Set_Type; 1124 Status : out Selector_Status; 1125 Timeout : Selector_Duration := Forever); 1126 -- Return when one Socket in R_Socket_Set has some data to be read or if 1127 -- one Socket in W_Socket_Set is ready to transmit some data. In these 1128 -- cases Status is set to Completed and sockets that are ready are set in 1129 -- R_Socket_Set or W_Socket_Set. Status is set to Expired if no socket was 1130 -- ready after a Timeout expiration. Status is set to Aborted if an abort 1131 -- signal has been received while checking socket status. 1132 -- 1133 -- Note that two different Socket_Set_Type objects must be passed as 1134 -- R_Socket_Set and W_Socket_Set (even if they denote the same set of 1135 -- Sockets), or some event may be lost. Also keep in mind that this 1136 -- procedure modifies the passed socket sets to indicate which sockets 1137 -- actually had events upon return. The socket set therefore has to 1138 -- be reset by the caller for further calls. 1139 -- 1140 -- Socket_Error is raised when the select(2) system call returns an error 1141 -- condition, or when a read error occurs on the signalling socket used for 1142 -- the implementation of Abort_Selector. 1143 1144 procedure Check_Selector 1145 (Selector : Selector_Type; 1146 R_Socket_Set : in out Socket_Set_Type; 1147 W_Socket_Set : in out Socket_Set_Type; 1148 E_Socket_Set : in out Socket_Set_Type; 1149 Status : out Selector_Status; 1150 Timeout : Selector_Duration := Forever); 1151 -- This refined version of Check_Selector allows watching for exception 1152 -- events (i.e. notifications of out-of-band transmission and reception). 1153 -- As above, all of R_Socket_Set, W_Socket_Set and E_Socket_Set must be 1154 -- different objects. 1155 1156 procedure Abort_Selector (Selector : Selector_Type); 1157 -- Send an abort signal to the selector. The Selector may not be the 1158 -- Null_Selector. 1159 1160 type Fd_Set is private; 1161 -- ??? This type must not be used directly, it needs to be visible because 1162 -- it is used in the visible part of GNAT.Sockets.Thin_Common. This is 1163 -- really an inversion of abstraction. The private part of GNAT.Sockets 1164 -- needs to have visibility on this type, but since Thin_Common is a child 1165 -- of Sockets, the type can't be declared there. The correct fix would 1166 -- be to move the thin sockets binding outside of GNAT.Sockets altogether, 1167 -- e.g. by renaming it to GNAT.Sockets_Thin. 1168 1169private 1170 1171 type Socket_Type is new Integer; 1172 No_Socket : constant Socket_Type := -1; 1173 1174 -- A selector is either a null selector, which is always "open" and can 1175 -- never be aborted, or a regular selector, which is created "closed", 1176 -- becomes "open" when Create_Selector is called, and "closed" again when 1177 -- Close_Selector is called. 1178 1179 type Selector_Type (Is_Null : Boolean := False) is limited record 1180 case Is_Null is 1181 when True => 1182 null; 1183 1184 when False => 1185 R_Sig_Socket : Socket_Type := No_Socket; 1186 W_Sig_Socket : Socket_Type := No_Socket; 1187 -- Signalling sockets used to abort a select operation 1188 end case; 1189 end record; 1190 1191 pragma Volatile (Selector_Type); 1192 1193 Null_Selector : constant Selector_Type := (Is_Null => True); 1194 1195 type Fd_Set is 1196 new System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_fd_set); 1197 for Fd_Set'Alignment use Interfaces.C.long'Alignment; 1198 -- Set conservative alignment so that our Fd_Sets are always adequately 1199 -- aligned for the underlying data type (which is implementation defined 1200 -- and may be an array of C long integers). 1201 1202 type Fd_Set_Access is access all Fd_Set; 1203 pragma Convention (C, Fd_Set_Access); 1204 No_Fd_Set_Access : constant Fd_Set_Access := null; 1205 1206 type Socket_Set_Type is record 1207 Last : Socket_Type := No_Socket; 1208 -- Highest socket in set. Last = No_Socket denotes an empty set (which 1209 -- is the default initial value). 1210 1211 Set : aliased Fd_Set; 1212 -- Underlying socket set. Note that the contents of this component is 1213 -- undefined if Last = No_Socket. 1214 end record; 1215 1216 subtype Inet_Addr_Comp_Type is Natural range 0 .. 255; 1217 -- Octet for Internet address 1218 1219 type Inet_Addr_VN_Type is array (Natural range <>) of Inet_Addr_Comp_Type; 1220 1221 subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 .. 4); 1222 subtype Inet_Addr_V6_Type is Inet_Addr_VN_Type (1 .. 16); 1223 1224 type Inet_Addr_Type (Family : Family_Type := Family_Inet) is record 1225 case Family is 1226 when Family_Inet => 1227 Sin_V4 : Inet_Addr_V4_Type := (others => 0); 1228 1229 when Family_Inet6 => 1230 Sin_V6 : Inet_Addr_V6_Type := (others => 0); 1231 end case; 1232 end record; 1233 1234 Any_Port : constant Port_Type := 0; 1235 No_Port : constant Port_Type := 0; 1236 1237 Any_Inet_Addr : constant Inet_Addr_Type := 1238 (Family_Inet, (others => 0)); 1239 No_Inet_Addr : constant Inet_Addr_Type := 1240 (Family_Inet, (others => 0)); 1241 Broadcast_Inet_Addr : constant Inet_Addr_Type := 1242 (Family_Inet, (others => 255)); 1243 Loopback_Inet_Addr : constant Inet_Addr_Type := 1244 (Family_Inet, (127, 0, 0, 1)); 1245 1246 Unspecified_Group_Inet_Addr : constant Inet_Addr_Type := 1247 (Family_Inet, (224, 0, 0, 0)); 1248 All_Hosts_Group_Inet_Addr : constant Inet_Addr_Type := 1249 (Family_Inet, (224, 0, 0, 1)); 1250 All_Routers_Group_Inet_Addr : constant Inet_Addr_Type := 1251 (Family_Inet, (224, 0, 0, 2)); 1252 1253 No_Sock_Addr : constant Sock_Addr_Type := (Family_Inet, No_Inet_Addr, 0); 1254 1255 Max_Name_Length : constant := 64; 1256 -- The constant MAXHOSTNAMELEN is usually set to 64 1257 1258 subtype Name_Index is Natural range 1 .. Max_Name_Length; 1259 1260 type Name_Type (Length : Name_Index := Max_Name_Length) is record 1261 Name : String (1 .. Length); 1262 end record; 1263 -- We need fixed strings to avoid access types in host entry type 1264 1265 type Name_Array is array (Natural range <>) of Name_Type; 1266 type Inet_Addr_Array is array (Natural range <>) of Inet_Addr_Type; 1267 1268 type Host_Entry_Type (Aliases_Length, Addresses_Length : Natural) is record 1269 Official : Name_Type; 1270 Aliases : Name_Array (1 .. Aliases_Length); 1271 Addresses : Inet_Addr_Array (1 .. Addresses_Length); 1272 end record; 1273 1274 type Service_Entry_Type (Aliases_Length : Natural) is record 1275 Official : Name_Type; 1276 Port : Port_Type; 1277 Protocol : Name_Type; 1278 Aliases : Name_Array (1 .. Aliases_Length); 1279 end record; 1280 1281 type Request_Flag_Type is mod 2 ** 8; 1282 No_Request_Flag : constant Request_Flag_Type := 0; 1283 Process_Out_Of_Band_Data : constant Request_Flag_Type := 1; 1284 Peek_At_Incoming_Data : constant Request_Flag_Type := 2; 1285 Wait_For_A_Full_Reception : constant Request_Flag_Type := 4; 1286 Send_End_Of_Record : constant Request_Flag_Type := 8; 1287 1288end GNAT.Sockets; 1289