1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . S O C K E T S --
9 -- Copyright (C) 2001-2004 Ada Core Technologies, Inc. --
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 2, 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with Ada.Streams; use Ada.Streams;
35 with Ada.Exceptions; use Ada.Exceptions;
36 with Ada.Unchecked_Conversion;
38 with Interfaces.C.Strings;
40 with GNAT.OS_Lib; use GNAT.OS_Lib;
41 with GNAT.Sockets.Constants;
42 with GNAT.Sockets.Thin; use GNAT.Sockets.Thin;
45 with GNAT.Sockets.Linker_Options;
46 pragma Warnings (Off, GNAT.Sockets.Linker_Options);
47 -- Need to include pragma Linker_Options which is platform dependent
49 with System; use System;
51 package body GNAT.Sockets is
53 use type C.int, System.Address;
55 Finalized : Boolean := False;
56 Initialized : Boolean := False;
58 ENOERROR : constant := 0;
60 -- Correspondance tables
62 Families : constant array (Family_Type) of C.int :=
63 (Family_Inet => Constants.AF_INET,
64 Family_Inet6 => Constants.AF_INET6);
66 Levels : constant array (Level_Type) of C.int :=
67 (Socket_Level => Constants.SOL_SOCKET,
68 IP_Protocol_For_IP_Level => Constants.IPPROTO_IP,
69 IP_Protocol_For_UDP_Level => Constants.IPPROTO_UDP,
70 IP_Protocol_For_TCP_Level => Constants.IPPROTO_TCP);
72 Modes : constant array (Mode_Type) of C.int :=
73 (Socket_Stream => Constants.SOCK_STREAM,
74 Socket_Datagram => Constants.SOCK_DGRAM);
76 Shutmodes : constant array (Shutmode_Type) of C.int :=
77 (Shut_Read => Constants.SHUT_RD,
78 Shut_Write => Constants.SHUT_WR,
79 Shut_Read_Write => Constants.SHUT_RDWR);
81 Requests : constant array (Request_Name) of C.int :=
82 (Non_Blocking_IO => Constants.FIONBIO,
83 N_Bytes_To_Read => Constants.FIONREAD);
85 Options : constant array (Option_Name) of C.int :=
86 (Keep_Alive => Constants.SO_KEEPALIVE,
87 Reuse_Address => Constants.SO_REUSEADDR,
88 Broadcast => Constants.SO_BROADCAST,
89 Send_Buffer => Constants.SO_SNDBUF,
90 Receive_Buffer => Constants.SO_RCVBUF,
91 Linger => Constants.SO_LINGER,
92 Error => Constants.SO_ERROR,
93 No_Delay => Constants.TCP_NODELAY,
94 Add_Membership => Constants.IP_ADD_MEMBERSHIP,
95 Drop_Membership => Constants.IP_DROP_MEMBERSHIP,
96 Multicast_TTL => Constants.IP_MULTICAST_TTL,
97 Multicast_Loop => Constants.IP_MULTICAST_LOOP);
99 Flags : constant array (0 .. 3) of C.int :=
100 (0 => Constants.MSG_OOB, -- Process_Out_Of_Band_Data
101 1 => Constants.MSG_PEEK, -- Peek_At_Incoming_Data
102 2 => Constants.MSG_WAITALL, -- Wait_For_A_Full_Reception
103 3 => Constants.MSG_EOR); -- Send_End_Of_Record
105 Socket_Error_Id : constant Exception_Id := Socket_Error'Identity;
106 Host_Error_Id : constant Exception_Id := Host_Error'Identity;
108 Hex_To_Char : constant String (1 .. 16) := "0123456789ABCDEF";
109 -- Use to print in hexadecimal format
111 function To_In_Addr is new Ada.Unchecked_Conversion (C.int, In_Addr);
112 function To_Int is new Ada.Unchecked_Conversion (In_Addr, C.int);
114 -----------------------
115 -- Local subprograms --
116 -----------------------
118 function Resolve_Error
119 (Error_Value : Integer;
120 From_Errno : Boolean := True) return Error_Type;
121 -- Associate an enumeration value (error_type) to en error value
122 -- (errno). From_Errno prevents from mixing h_errno with errno.
124 function To_Name (N : String) return Name_Type;
125 function To_String (HN : Name_Type) return String;
126 -- Conversion functions
128 function To_Int (F : Request_Flag_Type) return C.int;
129 -- Return the int value corresponding to the specified flags combination
131 function Set_Forced_Flags (F : C.int) return C.int;
132 -- Return F with the bits from Constants.MSG_Forced_Flags forced set
134 function Short_To_Network
135 (S : C.unsigned_short) return C.unsigned_short;
136 pragma Inline (Short_To_Network);
137 -- Convert a port number into a network port number
139 function Network_To_Short
140 (S : C.unsigned_short) return C.unsigned_short
141 renames Short_To_Network;
142 -- Symetric operation
145 (Val : Inet_Addr_VN_Type;
146 Hex : Boolean := False) return String;
147 -- Output an array of inet address components either in
148 -- hexadecimal or in decimal mode.
150 function Is_IP_Address (Name : String) return Boolean;
151 -- Return true when Name is an IP address in standard dot notation.
153 function To_In_Addr (Addr : Inet_Addr_Type) return Thin.In_Addr;
154 function To_Inet_Addr (Addr : In_Addr) return Inet_Addr_Type;
155 -- Conversion functions
157 function To_Host_Entry (E : Hostent) return Host_Entry_Type;
158 -- Conversion function
160 function To_Service_Entry (E : Servent) return Service_Entry_Type;
161 -- Conversion function
163 function To_Timeval (Val : Selector_Duration) return Timeval;
164 -- Separate Val in seconds and microseconds
166 procedure Raise_Socket_Error (Error : Integer);
167 -- Raise Socket_Error with an exception message describing
170 procedure Raise_Host_Error (Error : Integer);
171 -- Raise Host_Error exception with message describing error code
172 -- (note hstrerror seems to be obsolete).
174 procedure Narrow (Item : in out Socket_Set_Type);
175 -- Update Last as it may be greater than the real last socket
177 -- Types needed for Datagram_Socket_Stream_Type
179 type Datagram_Socket_Stream_Type is new Root_Stream_Type with record
180 Socket : Socket_Type;
182 From : Sock_Addr_Type;
185 type Datagram_Socket_Stream_Access is
186 access all Datagram_Socket_Stream_Type;
189 (Stream : in out Datagram_Socket_Stream_Type;
190 Item : out Ada.Streams.Stream_Element_Array;
191 Last : out Ada.Streams.Stream_Element_Offset);
194 (Stream : in out Datagram_Socket_Stream_Type;
195 Item : Ada.Streams.Stream_Element_Array);
197 -- Types needed for Stream_Socket_Stream_Type
199 type Stream_Socket_Stream_Type is new Root_Stream_Type with record
200 Socket : Socket_Type;
203 type Stream_Socket_Stream_Access is
204 access all Stream_Socket_Stream_Type;
207 (Stream : in out Stream_Socket_Stream_Type;
208 Item : out Ada.Streams.Stream_Element_Array;
209 Last : out Ada.Streams.Stream_Element_Offset);
212 (Stream : in out Stream_Socket_Stream_Type;
213 Item : Ada.Streams.Stream_Element_Array);
219 function "+" (L, R : Request_Flag_Type) return Request_Flag_Type is
228 procedure Abort_Selector (Selector : Selector_Type) is
229 Buf : aliased Character := ASCII.NUL;
231 pragma Unreferenced (Discard);
234 -- Send an empty array to unblock C select system call
236 Discard := C_Write (C.int (Selector.W_Sig_Socket), Buf'Address, 1);
243 procedure Accept_Socket
244 (Server : Socket_Type;
245 Socket : out Socket_Type;
246 Address : out Sock_Addr_Type)
249 Sin : aliased Sockaddr_In;
250 Len : aliased C.int := Sin'Size / 8;
253 Res := C_Accept (C.int (Server), Sin'Address, Len'Access);
255 if Res = Failure then
256 Raise_Socket_Error (Socket_Errno);
259 Socket := Socket_Type (Res);
261 Address.Addr := To_Inet_Addr (Sin.Sin_Addr);
262 Address.Port := Port_Type (Network_To_Short (Sin.Sin_Port));
270 (E : Host_Entry_Type;
271 N : Positive := 1) return Inet_Addr_Type
274 return E.Addresses (N);
277 ----------------------
278 -- Addresses_Length --
279 ----------------------
281 function Addresses_Length (E : Host_Entry_Type) return Natural is
283 return E.Addresses_Length;
284 end Addresses_Length;
291 (E : Host_Entry_Type;
292 N : Positive := 1) return String
295 return To_String (E.Aliases (N));
303 (S : Service_Entry_Type;
304 N : Positive := 1) return String
307 return To_String (S.Aliases (N));
314 function Aliases_Length (E : Host_Entry_Type) return Natural is
316 return E.Aliases_Length;
323 function Aliases_Length (S : Service_Entry_Type) return Natural is
325 return S.Aliases_Length;
332 procedure Bind_Socket
333 (Socket : Socket_Type;
334 Address : Sock_Addr_Type)
337 Sin : aliased Sockaddr_In;
338 Len : constant C.int := Sin'Size / 8;
341 if Address.Family = Family_Inet6 then
345 Set_Length (Sin'Unchecked_Access, Len);
346 Set_Family (Sin'Unchecked_Access, Families (Address.Family));
348 (Sin'Unchecked_Access,
349 Short_To_Network (C.unsigned_short (Address.Port)));
351 Res := C_Bind (C.int (Socket), Sin'Address, Len);
353 if Res = Failure then
354 Raise_Socket_Error (Socket_Errno);
362 procedure Check_Selector
363 (Selector : in out Selector_Type;
364 R_Socket_Set : in out Socket_Set_Type;
365 W_Socket_Set : in out Socket_Set_Type;
366 Status : out Selector_Status;
367 Timeout : Selector_Duration := Forever)
369 E_Socket_Set : Socket_Set_Type; -- (No_Socket, No_Socket_Set)
372 (Selector, R_Socket_Set, W_Socket_Set, E_Socket_Set, Status, Timeout);
375 procedure Check_Selector
376 (Selector : in out Selector_Type;
377 R_Socket_Set : in out Socket_Set_Type;
378 W_Socket_Set : in out Socket_Set_Type;
379 E_Socket_Set : in out Socket_Set_Type;
380 Status : out Selector_Status;
381 Timeout : Selector_Duration := Forever)
385 RSet : Socket_Set_Type;
386 WSet : Socket_Set_Type;
387 ESet : Socket_Set_Type;
388 TVal : aliased Timeval;
389 TPtr : Timeval_Access;
394 -- No timeout or Forever is indicated by a null timeval pointer
396 if Timeout = Forever then
399 TVal := To_Timeval (Timeout);
400 TPtr := TVal'Unchecked_Access;
403 -- Copy R_Socket_Set in RSet and add read signalling socket
405 RSet := (Set => New_Socket_Set (R_Socket_Set.Set),
406 Last => R_Socket_Set.Last);
407 Set (RSet, Selector.R_Sig_Socket);
409 -- Copy W_Socket_Set in WSet
411 WSet := (Set => New_Socket_Set (W_Socket_Set.Set),
412 Last => W_Socket_Set.Last);
414 -- Copy E_Socket_Set in ESet
416 ESet := (Set => New_Socket_Set (E_Socket_Set.Set),
417 Last => E_Socket_Set.Last);
419 Last := C.int'Max (C.int'Max (C.int (RSet.Last),
431 if Res = Failure then
432 Raise_Socket_Error (Socket_Errno);
435 -- If Select was resumed because of read signalling socket,
436 -- read this data and remove socket from set.
438 if Is_Set (RSet, Selector.R_Sig_Socket) then
439 Clear (RSet, Selector.R_Sig_Socket);
444 Res := C_Read (C.int (Selector.R_Sig_Socket), Buf'Address, 1);
453 -- Update RSet, WSet and ESet in regard to their new socket
460 -- Reset RSet as it should be if R_Sig_Socket was not added
462 if Is_Empty (RSet) then
466 if Is_Empty (WSet) then
470 if Is_Empty (ESet) then
474 -- Deliver RSet, WSet and ESet
476 Empty (R_Socket_Set);
477 R_Socket_Set := RSet;
479 Empty (W_Socket_Set);
480 W_Socket_Set := WSet;
482 Empty (E_Socket_Set);
483 E_Socket_Set := ESet;
491 (Item : in out Socket_Set_Type;
492 Socket : Socket_Type)
494 Last : aliased C.int := C.int (Item.Last);
497 if Item.Last /= No_Socket then
498 Remove_Socket_From_Set (Item.Set, C.int (Socket));
499 Last_Socket_In_Set (Item.Set, Last'Unchecked_Access);
500 Item.Last := Socket_Type (Last);
508 -- Comments needed below ???
509 -- Why are exceptions ignored ???
511 procedure Close_Selector (Selector : in out Selector_Type) is
514 Close_Socket (Selector.R_Sig_Socket);
522 Close_Socket (Selector.W_Sig_Socket);
534 procedure Close_Socket (Socket : Socket_Type) is
538 Res := C_Close (C.int (Socket));
540 if Res = Failure then
541 Raise_Socket_Error (Socket_Errno);
549 procedure Connect_Socket
550 (Socket : Socket_Type;
551 Server : in out Sock_Addr_Type)
554 Sin : aliased Sockaddr_In;
555 Len : constant C.int := Sin'Size / 8;
558 if Server.Family = Family_Inet6 then
562 Set_Length (Sin'Unchecked_Access, Len);
563 Set_Family (Sin'Unchecked_Access, Families (Server.Family));
564 Set_Address (Sin'Unchecked_Access, To_In_Addr (Server.Addr));
566 (Sin'Unchecked_Access,
567 Short_To_Network (C.unsigned_short (Server.Port)));
569 Res := C_Connect (C.int (Socket), Sin'Address, Len);
571 if Res = Failure then
572 Raise_Socket_Error (Socket_Errno);
580 procedure Control_Socket
581 (Socket : Socket_Type;
582 Request : in out Request_Type)
589 when Non_Blocking_IO =>
590 Arg := C.int (Boolean'Pos (Request.Enabled));
592 when N_Bytes_To_Read =>
599 Requests (Request.Name),
600 Arg'Unchecked_Access);
602 if Res = Failure then
603 Raise_Socket_Error (Socket_Errno);
607 when Non_Blocking_IO =>
610 when N_Bytes_To_Read =>
611 Request.Size := Natural (Arg);
621 (Source : Socket_Set_Type;
622 Target : in out Socket_Set_Type)
626 if Source.Last /= No_Socket then
627 Target.Set := New_Socket_Set (Source.Set);
628 Target.Last := Source.Last;
632 ---------------------
633 -- Create_Selector --
634 ---------------------
636 procedure Create_Selector (Selector : out Selector_Type) is
641 Sin : aliased Sockaddr_In;
642 Len : aliased C.int := Sin'Size / 8;
646 -- We open two signalling sockets. One of them is used to
647 -- send data to the other, which is included in a C_Select
648 -- socket set. The communication is used to force the call
649 -- to C_Select to complete, and the waiting task to resume
652 -- Create a listening socket
654 S0 := C_Socket (Constants.AF_INET, Constants.SOCK_STREAM, 0);
656 Raise_Socket_Error (Socket_Errno);
659 -- Sin is already correctly initialized. Bind the socket to any
662 Res := C_Bind (S0, Sin'Address, Len);
663 if Res = Failure then
666 Raise_Socket_Error (Err);
669 -- Get the port used by the socket
671 Res := C_Getsockname (S0, Sin'Address, Len'Access);
673 if Res = Failure then
676 Raise_Socket_Error (Err);
679 Res := C_Listen (S0, 2);
681 if Res = Failure then
684 Raise_Socket_Error (Err);
687 S1 := C_Socket (Constants.AF_INET, Constants.SOCK_STREAM, 0);
692 Raise_Socket_Error (Err);
695 -- Use INADDR_LOOPBACK
697 Sin.Sin_Addr.S_B1 := 127;
698 Sin.Sin_Addr.S_B2 := 0;
699 Sin.Sin_Addr.S_B3 := 0;
700 Sin.Sin_Addr.S_B4 := 1;
702 -- Do a connect and accept the connection
704 Res := C_Connect (S1, Sin'Address, Len);
706 if Res = Failure then
710 Raise_Socket_Error (Err);
713 S2 := C_Accept (S0, Sin'Address, Len'Access);
719 Raise_Socket_Error (Err);
724 if Res = Failure then
725 Raise_Socket_Error (Socket_Errno);
728 Selector.R_Sig_Socket := Socket_Type (S1);
729 Selector.W_Sig_Socket := Socket_Type (S2);
736 procedure Create_Socket
737 (Socket : out Socket_Type;
738 Family : Family_Type := Family_Inet;
739 Mode : Mode_Type := Socket_Stream)
744 Res := C_Socket (Families (Family), Modes (Mode), 0);
746 if Res = Failure then
747 Raise_Socket_Error (Socket_Errno);
750 Socket := Socket_Type (Res);
757 procedure Empty (Item : in out Socket_Set_Type) is
759 if Item.Set /= No_Socket_Set then
760 Free_Socket_Set (Item.Set);
761 Item.Set := No_Socket_Set;
764 Item.Last := No_Socket;
771 procedure Finalize is
786 (Item : in out Socket_Set_Type;
787 Socket : out Socket_Type)
790 L : aliased C.int := C.int (Item.Last);
793 if Item.Last /= No_Socket then
795 (Item.Set, L'Unchecked_Access, S'Unchecked_Access);
796 Item.Last := Socket_Type (L);
797 Socket := Socket_Type (S);
807 function Get_Address (Stream : Stream_Access) return Sock_Addr_Type is
809 if Stream = null then
812 elsif Stream.all in Datagram_Socket_Stream_Type then
813 return Datagram_Socket_Stream_Type (Stream.all).From;
816 return Get_Peer_Name (Stream_Socket_Stream_Type (Stream.all).Socket);
820 -------------------------
821 -- Get_Host_By_Address --
822 -------------------------
824 function Get_Host_By_Address
825 (Address : Inet_Addr_Type;
826 Family : Family_Type := Family_Inet) return Host_Entry_Type
828 pragma Unreferenced (Family);
830 HA : aliased In_Addr := To_In_Addr (Address);
831 Res : Hostent_Access;
835 -- This C function is not always thread-safe. Protect against
836 -- concurrent access.
839 Res := C_Gethostbyaddr (HA'Address, HA'Size / 8, Constants.AF_INET);
844 Raise_Host_Error (Err);
847 -- Translate from the C format to the API format
850 HE : constant Host_Entry_Type := To_Host_Entry (Res.all);
856 end Get_Host_By_Address;
858 ----------------------
859 -- Get_Host_By_Name --
860 ----------------------
862 function Get_Host_By_Name (Name : String) return Host_Entry_Type is
863 HN : constant C.char_array := C.To_C (Name);
864 Res : Hostent_Access;
868 -- Detect IP address name and redirect to Inet_Addr
870 if Is_IP_Address (Name) then
871 return Get_Host_By_Address (Inet_Addr (Name));
874 -- This C function is not always thread-safe. Protect against
875 -- concurrent access.
878 Res := C_Gethostbyname (HN);
883 Raise_Host_Error (Err);
886 -- Translate from the C format to the API format
889 HE : constant Host_Entry_Type := To_Host_Entry (Res.all);
895 end Get_Host_By_Name;
901 function Get_Peer_Name (Socket : Socket_Type) return Sock_Addr_Type is
902 Sin : aliased Sockaddr_In;
903 Len : aliased C.int := Sin'Size / 8;
904 Res : Sock_Addr_Type (Family_Inet);
907 if C_Getpeername (C.int (Socket), Sin'Address, Len'Access) = Failure then
908 Raise_Socket_Error (Socket_Errno);
911 Res.Addr := To_Inet_Addr (Sin.Sin_Addr);
912 Res.Port := Port_Type (Network_To_Short (Sin.Sin_Port));
917 -------------------------
918 -- Get_Service_By_Name --
919 -------------------------
921 function Get_Service_By_Name
923 Protocol : String) return Service_Entry_Type
925 SN : constant C.char_array := C.To_C (Name);
926 SP : constant C.char_array := C.To_C (Protocol);
927 Res : Servent_Access;
930 -- This C function is not always thread-safe. Protect against
931 -- concurrent access.
934 Res := C_Getservbyname (SN, SP);
938 Ada.Exceptions.Raise_Exception
939 (Service_Error'Identity, "Service not found");
942 -- Translate from the C format to the API format
945 SE : constant Service_Entry_Type := To_Service_Entry (Res.all);
951 end Get_Service_By_Name;
953 -------------------------
954 -- Get_Service_By_Port --
955 -------------------------
957 function Get_Service_By_Port
959 Protocol : String) return Service_Entry_Type
961 SP : constant C.char_array := C.To_C (Protocol);
962 Res : Servent_Access;
965 -- This C function is not always thread-safe. Protect against
966 -- concurrent access.
969 Res := C_Getservbyport
970 (C.int (Short_To_Network (C.unsigned_short (Port))), SP);
974 Ada.Exceptions.Raise_Exception
975 (Service_Error'Identity, "Service not found");
978 -- Translate from the C format to the API format
981 SE : constant Service_Entry_Type := To_Service_Entry (Res.all);
987 end Get_Service_By_Port;
989 ---------------------
990 -- Get_Socket_Name --
991 ---------------------
993 function Get_Socket_Name
994 (Socket : Socket_Type) return Sock_Addr_Type
996 Sin : aliased Sockaddr_In;
997 Len : aliased C.int := Sin'Size / 8;
999 Addr : Sock_Addr_Type := No_Sock_Addr;
1002 Res := C_Getsockname (C.int (Socket), Sin'Address, Len'Access);
1003 if Res /= Failure then
1004 Addr.Addr := To_Inet_Addr (Sin.Sin_Addr);
1005 Addr.Port := Port_Type (Network_To_Short (Sin.Sin_Port));
1009 end Get_Socket_Name;
1011 -----------------------
1012 -- Get_Socket_Option --
1013 -----------------------
1015 function Get_Socket_Option
1016 (Socket : Socket_Type;
1017 Level : Level_Type := Socket_Level;
1018 Name : Option_Name) return Option_Type
1020 use type C.unsigned_char;
1022 V8 : aliased Two_Int;
1024 V1 : aliased C.unsigned_char;
1025 Len : aliased C.int;
1026 Add : System.Address;
1028 Opt : Option_Type (Name);
1032 when Multicast_Loop |
1060 Add, Len'Unchecked_Access);
1062 if Res = Failure then
1063 Raise_Socket_Error (Socket_Errno);
1071 Opt.Enabled := (V4 /= 0);
1074 Opt.Enabled := (V8 (V8'First) /= 0);
1075 Opt.Seconds := Natural (V8 (V8'Last));
1079 Opt.Size := Natural (V4);
1082 Opt.Error := Resolve_Error (Integer (V4));
1084 when Add_Membership |
1086 Opt.Multicast_Address := To_Inet_Addr (To_In_Addr (V8 (V8'First)));
1087 Opt.Local_Interface := To_Inet_Addr (To_In_Addr (V8 (V8'Last)));
1089 when Multicast_TTL =>
1090 Opt.Time_To_Live := Integer (V1);
1092 when Multicast_Loop =>
1093 Opt.Enabled := (V1 /= 0);
1098 end Get_Socket_Option;
1104 function Host_Name return String is
1105 Name : aliased C.char_array (1 .. 64);
1109 Res := C_Gethostname (Name'Address, Name'Length);
1111 if Res = Failure then
1112 Raise_Socket_Error (Socket_Errno);
1115 return C.To_Ada (Name);
1123 (Val : Inet_Addr_VN_Type;
1124 Hex : Boolean := False) return String
1126 -- The largest Inet_Addr_Comp_Type image occurs with IPv4. It
1127 -- has at most a length of 3 plus one '.' character.
1129 Buffer : String (1 .. 4 * Val'Length);
1130 Length : Natural := 1;
1131 Separator : Character;
1133 procedure Img10 (V : Inet_Addr_Comp_Type);
1134 -- Append to Buffer image of V in decimal format
1136 procedure Img16 (V : Inet_Addr_Comp_Type);
1137 -- Append to Buffer image of V in hexadecimal format
1143 procedure Img10 (V : Inet_Addr_Comp_Type) is
1144 Img : constant String := V'Img;
1145 Len : constant Natural := Img'Length - 1;
1148 Buffer (Length .. Length + Len - 1) := Img (2 .. Img'Last);
1149 Length := Length + Len;
1156 procedure Img16 (V : Inet_Addr_Comp_Type) is
1158 Buffer (Length) := Hex_To_Char (Natural (V / 16) + 1);
1159 Buffer (Length + 1) := Hex_To_Char (Natural (V mod 16) + 1);
1160 Length := Length + 2;
1163 -- Start of processing for Image
1172 for J in Val'Range loop
1179 if J /= Val'Last then
1180 Buffer (Length) := Separator;
1181 Length := Length + 1;
1185 return Buffer (1 .. Length - 1);
1192 function Image (Value : Inet_Addr_Type) return String is
1194 if Value.Family = Family_Inet then
1195 return Image (Inet_Addr_VN_Type (Value.Sin_V4), Hex => False);
1197 return Image (Inet_Addr_VN_Type (Value.Sin_V6), Hex => True);
1205 function Image (Value : Sock_Addr_Type) return String is
1206 Port : constant String := Value.Port'Img;
1208 return Image (Value.Addr) & ':' & Port (2 .. Port'Last);
1215 function Image (Socket : Socket_Type) return String is
1224 function Inet_Addr (Image : String) return Inet_Addr_Type is
1225 use Interfaces.C.Strings;
1227 Img : chars_ptr := New_String (Image);
1232 Res := C_Inet_Addr (Img);
1236 if Res = Failure then
1237 Raise_Socket_Error (Err);
1240 return To_Inet_Addr (To_In_Addr (Res));
1247 procedure Initialize (Process_Blocking_IO : Boolean := False) is
1249 if not Initialized then
1250 Initialized := True;
1251 Thin.Initialize (Process_Blocking_IO);
1259 function Is_Empty (Item : Socket_Set_Type) return Boolean is
1261 return Item.Last = No_Socket;
1268 function Is_IP_Address (Name : String) return Boolean is
1270 for J in Name'Range loop
1272 and then Name (J) not in '0' .. '9'
1286 (Item : Socket_Set_Type;
1287 Socket : Socket_Type) return Boolean
1290 return Item.Last /= No_Socket
1291 and then Socket <= Item.Last
1292 and then Is_Socket_In_Set (Item.Set, C.int (Socket)) /= 0;
1299 procedure Listen_Socket
1300 (Socket : Socket_Type;
1301 Length : Positive := 15)
1303 Res : constant C.int := C_Listen (C.int (Socket), C.int (Length));
1305 if Res = Failure then
1306 Raise_Socket_Error (Socket_Errno);
1314 procedure Narrow (Item : in out Socket_Set_Type) is
1315 Last : aliased C.int := C.int (Item.Last);
1317 if Item.Set /= No_Socket_Set then
1318 Last_Socket_In_Set (Item.Set, Last'Unchecked_Access);
1319 Item.Last := Socket_Type (Last);
1327 function Official_Name (E : Host_Entry_Type) return String is
1329 return To_String (E.Official);
1336 function Official_Name (S : Service_Entry_Type) return String is
1338 return To_String (S.Official);
1345 function Port_Number (S : Service_Entry_Type) return Port_Type is
1354 function Protocol_Name (S : Service_Entry_Type) return String is
1356 return To_String (S.Protocol);
1359 ----------------------
1360 -- Raise_Host_Error --
1361 ----------------------
1363 procedure Raise_Host_Error (Error : Integer) is
1365 function Host_Error_Message return String;
1366 -- We do not use a C function like strerror because hstrerror
1367 -- that would correspond seems to be obsolete. Return
1368 -- appropriate string for error value.
1370 ------------------------
1371 -- Host_Error_Message --
1372 ------------------------
1374 function Host_Error_Message return String is
1377 when Constants.HOST_NOT_FOUND => return "Host not found";
1378 when Constants.TRY_AGAIN => return "Try again";
1379 when Constants.NO_RECOVERY => return "No recovery";
1380 when Constants.NO_DATA => return "No address";
1381 when others => return "Unknown error";
1383 end Host_Error_Message;
1385 -- Start of processing for Raise_Host_Error
1388 Ada.Exceptions.Raise_Exception (Host_Error'Identity, Host_Error_Message);
1389 end Raise_Host_Error;
1391 ------------------------
1392 -- Raise_Socket_Error --
1393 ------------------------
1395 procedure Raise_Socket_Error (Error : Integer) is
1396 use type C.Strings.chars_ptr;
1398 function Image (E : Integer) return String;
1404 function Image (E : Integer) return String is
1405 Msg : String := E'Img & "] ";
1407 Msg (Msg'First) := '[';
1411 -- Start of processing for Raise_Socket_Error
1414 Ada.Exceptions.Raise_Exception
1415 (Socket_Error'Identity,
1416 Image (Error) & C.Strings.Value (Socket_Error_Message (Error)));
1417 end Raise_Socket_Error;
1424 (Stream : in out Datagram_Socket_Stream_Type;
1425 Item : out Ada.Streams.Stream_Element_Array;
1426 Last : out Ada.Streams.Stream_Element_Offset)
1428 First : Ada.Streams.Stream_Element_Offset := Item'First;
1429 Index : Ada.Streams.Stream_Element_Offset := First - 1;
1430 Max : constant Ada.Streams.Stream_Element_Offset := Item'Last;
1436 Item (First .. Max),
1442 -- Exit when all or zero data received. Zero means that
1443 -- the socket peer is closed.
1445 exit when Index < First or else Index = Max;
1456 (Stream : in out Stream_Socket_Stream_Type;
1457 Item : out Ada.Streams.Stream_Element_Array;
1458 Last : out Ada.Streams.Stream_Element_Offset)
1460 First : Ada.Streams.Stream_Element_Offset := Item'First;
1461 Index : Ada.Streams.Stream_Element_Offset := First - 1;
1462 Max : constant Ada.Streams.Stream_Element_Offset := Item'Last;
1466 Receive_Socket (Stream.Socket, Item (First .. Max), Index);
1469 -- Exit when all or zero data received. Zero means that
1470 -- the socket peer is closed.
1472 exit when Index < First or else Index = Max;
1478 --------------------
1479 -- Receive_Socket --
1480 --------------------
1482 procedure Receive_Socket
1483 (Socket : Socket_Type;
1484 Item : out Ada.Streams.Stream_Element_Array;
1485 Last : out Ada.Streams.Stream_Element_Offset;
1486 Flags : Request_Flag_Type := No_Request_Flag)
1488 use type Ada.Streams.Stream_Element_Offset;
1495 Item (Item'First)'Address,
1499 if Res = Failure then
1500 Raise_Socket_Error (Socket_Errno);
1503 Last := Item'First + Ada.Streams.Stream_Element_Offset (Res - 1);
1506 --------------------
1507 -- Receive_Socket --
1508 --------------------
1510 procedure Receive_Socket
1511 (Socket : Socket_Type;
1512 Item : out Ada.Streams.Stream_Element_Array;
1513 Last : out Ada.Streams.Stream_Element_Offset;
1514 From : out Sock_Addr_Type;
1515 Flags : Request_Flag_Type := No_Request_Flag)
1517 use type Ada.Streams.Stream_Element_Offset;
1520 Sin : aliased Sockaddr_In;
1521 Len : aliased C.int := Sin'Size / 8;
1527 Item (Item'First)'Address,
1530 Sin'Unchecked_Access,
1531 Len'Unchecked_Access);
1533 if Res = Failure then
1534 Raise_Socket_Error (Socket_Errno);
1537 Last := Item'First + Ada.Streams.Stream_Element_Offset (Res - 1);
1539 From.Addr := To_Inet_Addr (Sin.Sin_Addr);
1540 From.Port := Port_Type (Network_To_Short (Sin.Sin_Port));
1547 function Resolve_Error
1548 (Error_Value : Integer;
1549 From_Errno : Boolean := True) return Error_Type
1551 use GNAT.Sockets.Constants;
1554 if not From_Errno then
1556 when Constants.HOST_NOT_FOUND => return Unknown_Host;
1557 when Constants.TRY_AGAIN => return Host_Name_Lookup_Failure;
1558 when Constants.NO_RECOVERY =>
1559 return Non_Recoverable_Error;
1560 when Constants.NO_DATA => return Unknown_Server_Error;
1561 when others => return Cannot_Resolve_Error;
1566 when ENOERROR => return Success;
1567 when EACCES => return Permission_Denied;
1568 when EADDRINUSE => return Address_Already_In_Use;
1569 when EADDRNOTAVAIL => return Cannot_Assign_Requested_Address;
1570 when EAFNOSUPPORT =>
1571 return Address_Family_Not_Supported_By_Protocol;
1572 when EALREADY => return Operation_Already_In_Progress;
1573 when EBADF => return Bad_File_Descriptor;
1574 when ECONNABORTED => return Software_Caused_Connection_Abort;
1575 when ECONNREFUSED => return Connection_Refused;
1576 when ECONNRESET => return Connection_Reset_By_Peer;
1577 when EDESTADDRREQ => return Destination_Address_Required;
1578 when EFAULT => return Bad_Address;
1579 when EHOSTDOWN => return Host_Is_Down;
1580 when EHOSTUNREACH => return No_Route_To_Host;
1581 when EINPROGRESS => return Operation_Now_In_Progress;
1582 when EINTR => return Interrupted_System_Call;
1583 when EINVAL => return Invalid_Argument;
1584 when EIO => return Input_Output_Error;
1585 when EISCONN => return Transport_Endpoint_Already_Connected;
1586 when ELOOP => return Too_Many_Symbolic_Links;
1587 when EMFILE => return Too_Many_Open_Files;
1588 when EMSGSIZE => return Message_Too_Long;
1589 when ENAMETOOLONG => return File_Name_Too_Long;
1590 when ENETDOWN => return Network_Is_Down;
1592 return Network_Dropped_Connection_Because_Of_Reset;
1593 when ENETUNREACH => return Network_Is_Unreachable;
1594 when ENOBUFS => return No_Buffer_Space_Available;
1595 when ENOPROTOOPT => return Protocol_Not_Available;
1596 when ENOTCONN => return Transport_Endpoint_Not_Connected;
1597 when ENOTSOCK => return Socket_Operation_On_Non_Socket;
1598 when EOPNOTSUPP => return Operation_Not_Supported;
1599 when EPFNOSUPPORT => return Protocol_Family_Not_Supported;
1600 when EPROTONOSUPPORT => return Protocol_Not_Supported;
1601 when EPROTOTYPE => return Protocol_Wrong_Type_For_Socket;
1603 return Cannot_Send_After_Transport_Endpoint_Shutdown;
1604 when ESOCKTNOSUPPORT => return Socket_Type_Not_Supported;
1605 when ETIMEDOUT => return Connection_Timed_Out;
1606 when ETOOMANYREFS => return Too_Many_References;
1607 when EWOULDBLOCK => return Resource_Temporarily_Unavailable;
1608 when others => null;
1611 return Cannot_Resolve_Error;
1614 -----------------------
1615 -- Resolve_Exception --
1616 -----------------------
1618 function Resolve_Exception
1619 (Occurrence : Exception_Occurrence) return Error_Type
1621 Id : constant Exception_Id := Exception_Identity (Occurrence);
1622 Msg : constant String := Exception_Message (Occurrence);
1623 First : Natural := Msg'First;
1628 while First <= Msg'Last
1629 and then Msg (First) not in '0' .. '9'
1634 if First > Msg'Last then
1635 return Cannot_Resolve_Error;
1640 while Last < Msg'Last
1641 and then Msg (Last + 1) in '0' .. '9'
1646 Val := Integer'Value (Msg (First .. Last));
1648 if Id = Socket_Error_Id then
1649 return Resolve_Error (Val);
1650 elsif Id = Host_Error_Id then
1651 return Resolve_Error (Val, False);
1653 return Cannot_Resolve_Error;
1655 end Resolve_Exception;
1657 --------------------
1658 -- Receive_Vector --
1659 --------------------
1661 procedure Receive_Vector
1662 (Socket : Socket_Type;
1663 Vector : Vector_Type;
1664 Count : out Ada.Streams.Stream_Element_Count)
1672 Vector (Vector'First)'Address,
1675 if Res = Failure then
1676 Raise_Socket_Error (Socket_Errno);
1679 Count := Ada.Streams.Stream_Element_Count (Res);
1686 procedure Send_Socket
1687 (Socket : Socket_Type;
1688 Item : Ada.Streams.Stream_Element_Array;
1689 Last : out Ada.Streams.Stream_Element_Offset;
1690 Flags : Request_Flag_Type := No_Request_Flag)
1692 use type Ada.Streams.Stream_Element_Offset;
1700 Item (Item'First)'Address,
1702 Set_Forced_Flags (To_Int (Flags)));
1704 if Res = Failure then
1705 Raise_Socket_Error (Socket_Errno);
1708 Last := Item'First + Ada.Streams.Stream_Element_Offset (Res - 1);
1715 procedure Send_Socket
1716 (Socket : Socket_Type;
1717 Item : Ada.Streams.Stream_Element_Array;
1718 Last : out Ada.Streams.Stream_Element_Offset;
1719 To : Sock_Addr_Type;
1720 Flags : Request_Flag_Type := No_Request_Flag)
1722 use type Ada.Streams.Stream_Element_Offset;
1725 Sin : aliased Sockaddr_In;
1726 Len : constant C.int := Sin'Size / 8;
1729 Set_Length (Sin'Unchecked_Access, Len);
1730 Set_Family (Sin'Unchecked_Access, Families (To.Family));
1731 Set_Address (Sin'Unchecked_Access, To_In_Addr (To.Addr));
1733 (Sin'Unchecked_Access,
1734 Short_To_Network (C.unsigned_short (To.Port)));
1738 Item (Item'First)'Address,
1740 Set_Forced_Flags (To_Int (Flags)),
1741 Sin'Unchecked_Access,
1744 if Res = Failure then
1745 Raise_Socket_Error (Socket_Errno);
1748 Last := Item'First + Ada.Streams.Stream_Element_Offset (Res - 1);
1755 procedure Send_Vector
1756 (Socket : Socket_Type;
1757 Vector : Vector_Type;
1758 Count : out Ada.Streams.Stream_Element_Count)
1766 Vector (Vector'First)'Address,
1769 if Res = Failure then
1770 Raise_Socket_Error (Socket_Errno);
1773 Count := Ada.Streams.Stream_Element_Count (Res);
1780 procedure Set (Item : in out Socket_Set_Type; Socket : Socket_Type) is
1782 if Item.Set = No_Socket_Set then
1783 Item.Set := New_Socket_Set (No_Socket_Set);
1784 Item.Last := Socket;
1786 elsif Item.Last < Socket then
1787 Item.Last := Socket;
1790 Insert_Socket_In_Set (Item.Set, C.int (Socket));
1793 ----------------------
1794 -- Set_Forced_Flags --
1795 ----------------------
1797 function Set_Forced_Flags (F : C.int) return C.int is
1798 use type C.unsigned;
1799 function To_unsigned is
1800 new Ada.Unchecked_Conversion (C.int, C.unsigned);
1802 new Ada.Unchecked_Conversion (C.unsigned, C.int);
1804 return To_int (To_unsigned (F) or Constants.MSG_Forced_Flags);
1805 end Set_Forced_Flags;
1807 -----------------------
1808 -- Set_Socket_Option --
1809 -----------------------
1811 procedure Set_Socket_Option
1812 (Socket : Socket_Type;
1813 Level : Level_Type := Socket_Level;
1814 Option : Option_Type)
1816 V8 : aliased Two_Int;
1818 V1 : aliased C.unsigned_char;
1819 Len : aliased C.int;
1820 Add : System.Address := Null_Address;
1829 V4 := C.int (Boolean'Pos (Option.Enabled));
1834 V8 (V8'First) := C.int (Boolean'Pos (Option.Enabled));
1835 V8 (V8'Last) := C.int (Option.Seconds);
1841 V4 := C.int (Option.Size);
1846 V4 := C.int (Boolean'Pos (True));
1850 when Add_Membership |
1852 V8 (V8'First) := To_Int (To_In_Addr (Option.Multicast_Address));
1853 V8 (V8'Last) := To_Int (To_In_Addr (Option.Local_Interface));
1857 when Multicast_TTL =>
1858 V1 := C.unsigned_char (Option.Time_To_Live);
1862 when Multicast_Loop =>
1863 V1 := C.unsigned_char (Boolean'Pos (Option.Enabled));
1872 Options (Option.Name),
1875 if Res = Failure then
1876 Raise_Socket_Error (Socket_Errno);
1878 end Set_Socket_Option;
1880 ----------------------
1881 -- Short_To_Network --
1882 ----------------------
1884 function Short_To_Network (S : C.unsigned_short) return C.unsigned_short is
1885 use type C.unsigned_short;
1888 -- Big-endian case. No conversion needed. On these platforms,
1889 -- htons() defaults to a null procedure.
1891 pragma Warnings (Off);
1892 -- Since the test can generate "always True/False" warning
1894 if Default_Bit_Order = High_Order_First then
1897 pragma Warnings (On);
1899 -- Little-endian case. We must swap the high and low bytes of this
1900 -- short to make the port number network compliant.
1903 return (S / 256) + (S mod 256) * 256;
1905 end Short_To_Network;
1907 ---------------------
1908 -- Shutdown_Socket --
1909 ---------------------
1911 procedure Shutdown_Socket
1912 (Socket : Socket_Type;
1913 How : Shutmode_Type := Shut_Read_Write)
1918 Res := C_Shutdown (C.int (Socket), Shutmodes (How));
1920 if Res = Failure then
1921 Raise_Socket_Error (Socket_Errno);
1923 end Shutdown_Socket;
1930 (Socket : Socket_Type;
1931 Send_To : Sock_Addr_Type) return Stream_Access
1933 S : Datagram_Socket_Stream_Access;
1936 S := new Datagram_Socket_Stream_Type;
1939 S.From := Get_Socket_Name (Socket);
1940 return Stream_Access (S);
1947 function Stream (Socket : Socket_Type) return Stream_Access is
1948 S : Stream_Socket_Stream_Access;
1951 S := new Stream_Socket_Stream_Type;
1953 return Stream_Access (S);
1960 function To_C (Socket : Socket_Type) return Integer is
1962 return Integer (Socket);
1969 function To_Host_Entry (E : Hostent) return Host_Entry_Type is
1972 Official : constant String :=
1973 C.Strings.Value (E.H_Name);
1975 Aliases : constant Chars_Ptr_Array :=
1976 Chars_Ptr_Pointers.Value (E.H_Aliases);
1977 -- H_Aliases points to a list of name aliases. The list is
1978 -- terminated by a NULL pointer.
1980 Addresses : constant In_Addr_Access_Array :=
1981 In_Addr_Access_Pointers.Value (E.H_Addr_List);
1982 -- H_Addr_List points to a list of binary addresses (in network
1983 -- byte order). The list is terminated by a NULL pointer.
1985 -- H_Length is not used because it is currently only set to 4.
1986 -- H_Addrtype is always AF_INET
1988 Result : Host_Entry_Type
1989 (Aliases_Length => Aliases'Length - 1,
1990 Addresses_Length => Addresses'Length - 1);
1991 -- The last element is a null pointer
1997 Result.Official := To_Name (Official);
1999 Source := Aliases'First;
2000 Target := Result.Aliases'First;
2001 while Target <= Result.Aliases_Length loop
2002 Result.Aliases (Target) :=
2003 To_Name (C.Strings.Value (Aliases (Source)));
2004 Source := Source + 1;
2005 Target := Target + 1;
2008 Source := Addresses'First;
2009 Target := Result.Addresses'First;
2010 while Target <= Result.Addresses_Length loop
2011 Result.Addresses (Target) :=
2012 To_Inet_Addr (Addresses (Source).all);
2013 Source := Source + 1;
2014 Target := Target + 1;
2024 function To_In_Addr (Addr : Inet_Addr_Type) return Thin.In_Addr is
2026 if Addr.Family = Family_Inet then
2027 return (S_B1 => C.unsigned_char (Addr.Sin_V4 (1)),
2028 S_B2 => C.unsigned_char (Addr.Sin_V4 (2)),
2029 S_B3 => C.unsigned_char (Addr.Sin_V4 (3)),
2030 S_B4 => C.unsigned_char (Addr.Sin_V4 (4)));
2040 function To_Inet_Addr
2041 (Addr : In_Addr) return Inet_Addr_Type
2043 Result : Inet_Addr_Type;
2045 Result.Sin_V4 (1) := Inet_Addr_Comp_Type (Addr.S_B1);
2046 Result.Sin_V4 (2) := Inet_Addr_Comp_Type (Addr.S_B2);
2047 Result.Sin_V4 (3) := Inet_Addr_Comp_Type (Addr.S_B3);
2048 Result.Sin_V4 (4) := Inet_Addr_Comp_Type (Addr.S_B4);
2056 function To_Int (F : Request_Flag_Type) return C.int
2058 Current : Request_Flag_Type := F;
2059 Result : C.int := 0;
2062 for J in Flags'Range loop
2063 exit when Current = 0;
2065 if Current mod 2 /= 0 then
2066 if Flags (J) = -1 then
2067 Raise_Socket_Error (Constants.EOPNOTSUPP);
2069 Result := Result + Flags (J);
2072 Current := Current / 2;
2082 function To_Name (N : String) return Name_Type is
2084 return Name_Type'(N'Length, N);
2087 ----------------------
2088 -- To_Service_Entry --
2089 ----------------------
2091 function To_Service_Entry (E : Servent) return Service_Entry_Type is
2094 Official : constant String :=
2095 C.Strings.Value (E.S_Name);
2097 Aliases : constant Chars_Ptr_Array :=
2098 Chars_Ptr_Pointers.Value (E.S_Aliases);
2099 -- S_Aliases points to a list of name aliases. The list is
2100 -- terminated by a NULL pointer.
2102 Protocol : constant String :=
2103 C.Strings.Value (E.S_Proto);
2105 Result : Service_Entry_Type
2106 (Aliases_Length => Aliases'Length - 1);
2107 -- The last element is a null pointer
2113 Result.Official := To_Name (Official);
2115 Source := Aliases'First;
2116 Target := Result.Aliases'First;
2117 while Target <= Result.Aliases_Length loop
2118 Result.Aliases (Target) :=
2119 To_Name (C.Strings.Value (Aliases (Source)));
2120 Source := Source + 1;
2121 Target := Target + 1;
2125 Port_Type (Network_To_Short (C.unsigned_short (E.S_Port)));
2127 Result.Protocol := To_Name (Protocol);
2130 end To_Service_Entry;
2136 function To_String (HN : Name_Type) return String is
2138 return HN.Name (1 .. HN.Length);
2145 function To_Timeval (Val : Selector_Duration) return Timeval is
2150 -- If zero, set result as zero (otherwise it gets rounded down to -1)
2156 -- Normal case where we do round down
2159 S := Timeval_Unit (Val - 0.5);
2160 MS := Timeval_Unit (1_000_000 * (Val - Selector_Duration (S)));
2171 (Stream : in out Datagram_Socket_Stream_Type;
2172 Item : Ada.Streams.Stream_Element_Array)
2174 First : Ada.Streams.Stream_Element_Offset := Item'First;
2175 Index : Ada.Streams.Stream_Element_Offset := First - 1;
2176 Max : constant Ada.Streams.Stream_Element_Offset := Item'Last;
2182 Item (First .. Max),
2186 -- Exit when all or zero data sent. Zero means that the
2187 -- socket has been closed by peer.
2189 exit when Index < First or else Index = Max;
2194 if Index /= Max then
2204 (Stream : in out Stream_Socket_Stream_Type;
2205 Item : Ada.Streams.Stream_Element_Array)
2207 First : Ada.Streams.Stream_Element_Offset := Item'First;
2208 Index : Ada.Streams.Stream_Element_Offset := First - 1;
2209 Max : constant Ada.Streams.Stream_Element_Offset := Item'Last;
2213 Send_Socket (Stream.Socket, Item (First .. Max), Index);
2215 -- Exit when all or zero data sent. Zero means that the
2216 -- socket has been closed by peer.
2218 exit when Index < First or else Index = Max;
2223 if Index /= Max then