1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--              G N A T . S O C K E T S . T H I N _ C O M M O N             --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--                     Copyright (C) 2008-2012, 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 is the target-independent part of the thin sockets mapping.
33--  This package should not be directly with'ed by an applications program.
34
35with Ada.Unchecked_Conversion;
36
37with Interfaces.C;
38with Interfaces.C.Pointers;
39
40package GNAT.Sockets.Thin_Common is
41
42   package C renames Interfaces.C;
43
44   use type C.int;
45   --  This is so we can declare the Failure constant below
46
47   Success : constant C.int :=  0;
48   Failure : constant C.int := -1;
49
50   type time_t is
51     range -2 ** (8 * SOSC.SIZEOF_tv_sec - 1)
52         .. 2 ** (8 * SOSC.SIZEOF_tv_sec - 1) - 1;
53   for time_t'Size use 8 * SOSC.SIZEOF_tv_sec;
54   pragma Convention (C, time_t);
55
56   type suseconds_t is
57     range -2 ** (8 * SOSC.SIZEOF_tv_usec - 1)
58         .. 2 ** (8 * SOSC.SIZEOF_tv_usec - 1) - 1;
59   for suseconds_t'Size use 8 * SOSC.SIZEOF_tv_usec;
60   pragma Convention (C, suseconds_t);
61
62   type Timeval is record
63      Tv_Sec  : time_t;
64      Tv_Usec : suseconds_t;
65   end record;
66   pragma Convention (C, Timeval);
67
68   type Timeval_Access is access all Timeval;
69   pragma Convention (C, Timeval_Access);
70
71   Immediat : constant Timeval := (0, 0);
72
73   -------------------------------------------
74   -- Mapping tables to low level constants --
75   -------------------------------------------
76
77   Families : constant array (Family_Type) of C.int :=
78                (Family_Inet  => SOSC.AF_INET,
79                 Family_Inet6 => SOSC.AF_INET6);
80
81   Lengths  : constant array (Family_Type) of C.unsigned_char :=
82                (Family_Inet  => SOSC.SIZEOF_sockaddr_in,
83                 Family_Inet6 => SOSC.SIZEOF_sockaddr_in6);
84
85   ----------------------------
86   -- Generic socket address --
87   ----------------------------
88
89   --  Common header
90
91   --  All socket address types (struct sockaddr, struct sockaddr_storage,
92   --  and protocol specific address types) start with the same 2-byte header,
93   --  which is either a length and a family (one byte each) or just a two-byte
94   --  family. The following unchecked union describes the two possible layouts
95   --  and is meant to be constrained with SOSC.Have_Sockaddr_Len.
96
97   type Sockaddr_Length_And_Family
98     (Has_Sockaddr_Len : Boolean := False)
99   is record
100      case Has_Sockaddr_Len is
101         when True =>
102            Length      : C.unsigned_char;
103            Char_Family : C.unsigned_char;
104
105         when False =>
106            Short_Family : C.unsigned_short;
107      end case;
108   end record;
109   pragma Unchecked_Union (Sockaddr_Length_And_Family);
110   pragma Convention (C, Sockaddr_Length_And_Family);
111
112   procedure Set_Family
113     (Length_And_Family : out Sockaddr_Length_And_Family;
114      Family            : Family_Type);
115   --  Set the family component to the appropriate value for Family, and also
116   --  set Length accordingly if applicable on this platform.
117
118   type Sockaddr is record
119      Sa_Family : Sockaddr_Length_And_Family;
120      --  Address family (and address length on some platforms)
121
122      Sa_Data : C.char_array (1 .. 14) := (others => C.nul);
123      --  Family-specific data
124      --  Note that some platforms require that all unused (reserved) bytes
125      --  in addresses be initialized to 0 (e.g. VxWorks).
126   end record;
127   pragma Convention (C, Sockaddr);
128   --  Generic socket address
129
130   type Sockaddr_Access is access all Sockaddr;
131   pragma Convention (C, Sockaddr_Access);
132   --  Access to socket address
133
134   ----------------------------
135   -- AF_INET socket address --
136   ----------------------------
137
138   type In_Addr is record
139      S_B1, S_B2, S_B3, S_B4 : C.unsigned_char;
140   end record;
141   for In_Addr'Alignment use C.int'Alignment;
142   pragma Convention (C, In_Addr);
143   --  IPv4 address, represented as a network-order C.int. Note that the
144   --  underlying operating system may assume that values of this type have
145   --  C.int alignment, so we need to provide a suitable alignment clause here.
146
147   function To_In_Addr is new Ada.Unchecked_Conversion (C.int, In_Addr);
148   function To_Int     is new Ada.Unchecked_Conversion (In_Addr, C.int);
149
150   type In_Addr_Access is access all In_Addr;
151   pragma Convention (C, In_Addr_Access);
152   --  Access to internet address
153
154   Inaddr_Any : aliased constant In_Addr := (others => 0);
155   --  Any internet address (all the interfaces)
156
157   type In_Addr_Access_Array is array (C.size_t range <>)
158     of aliased In_Addr_Access;
159   pragma Convention (C, In_Addr_Access_Array);
160
161   package In_Addr_Access_Pointers is new C.Pointers
162     (C.size_t, In_Addr_Access, In_Addr_Access_Array, null);
163   --  Array of internet addresses
164
165   type Sockaddr_In is record
166      Sin_Family : Sockaddr_Length_And_Family;
167      --  Address family (and address length on some platforms)
168
169      Sin_Port : C.unsigned_short;
170      --  Port in network byte order
171
172      Sin_Addr : In_Addr;
173      --  IPv4 address
174
175      Sin_Zero : C.char_array (1 .. 8) := (others => C.nul);
176      --  Padding
177      --
178      --  Note that some platforms require that all unused (reserved) bytes
179      --  in addresses be initialized to 0 (e.g. VxWorks).
180   end record;
181   pragma Convention (C, Sockaddr_In);
182   --  Internet socket address
183
184   type Sockaddr_In_Access is access all Sockaddr_In;
185   pragma Convention (C, Sockaddr_In_Access);
186   --  Access to internet socket address
187
188   procedure Set_Port
189     (Sin  : Sockaddr_In_Access;
190      Port : C.unsigned_short);
191   pragma Inline (Set_Port);
192   --  Set Sin.Sin_Port to Port
193
194   procedure Set_Address
195     (Sin     : Sockaddr_In_Access;
196      Address : In_Addr);
197   pragma Inline (Set_Address);
198   --  Set Sin.Sin_Addr to Address
199
200   ------------------
201   -- Host entries --
202   ------------------
203
204   type Hostent is new
205     System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_struct_hostent);
206   for Hostent'Alignment use 8;
207   --  Host entry. This is an opaque type used only via the following
208   --  accessor functions, because 'struct hostent' has different layouts on
209   --  different platforms.
210
211   type Hostent_Access is access all Hostent;
212   pragma Convention (C, Hostent_Access);
213   --  Access to host entry
214
215   --  Note: the hostent and servent accessors that return char*
216   --  values are compiled with GCC, and on VMS they always return
217   --  64-bit pointers, so we can't use C.Strings.chars_ptr, which
218   --  on VMS is 32 bits.
219
220   function Hostent_H_Name
221     (E : Hostent_Access) return System.Address;
222
223   function Hostent_H_Alias
224     (E : Hostent_Access; I : C.int) return System.Address;
225
226   function Hostent_H_Addrtype
227     (E : Hostent_Access) return C.int;
228
229   function Hostent_H_Length
230     (E : Hostent_Access) return C.int;
231
232   function Hostent_H_Addr
233     (E : Hostent_Access; Index : C.int) return System.Address;
234
235   ---------------------
236   -- Service entries --
237   ---------------------
238
239   type Servent is new
240     System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_struct_servent);
241   for Servent'Alignment use 8;
242   --  Service entry. This is an opaque type used only via the following
243   --  accessor functions, because 'struct servent' has different layouts on
244   --  different platforms.
245
246   type Servent_Access is access all Servent;
247   pragma Convention (C, Servent_Access);
248   --  Access to service entry
249
250   function Servent_S_Name
251     (E : Servent_Access) return System.Address;
252
253   function Servent_S_Alias
254     (E : Servent_Access; Index : C.int) return System.Address;
255
256   function Servent_S_Port
257     (E : Servent_Access) return C.unsigned_short;
258
259   function Servent_S_Proto
260     (E : Servent_Access) return System.Address;
261
262   ------------------
263   -- NetDB access --
264   ------------------
265
266   --  There are three possible situations for the following NetDB access
267   --  functions:
268   --    - inherently thread safe (case of data returned in a thread specific
269   --      buffer);
270   --    - thread safe using user-provided buffer;
271   --    - thread unsafe.
272   --
273   --  In the first and third cases, the Buf and Buflen are ignored. In the
274   --  second case, the caller must provide a buffer large enough to
275   --  accommodate the returned data. In the third case, the caller must ensure
276   --  that these functions are called within a critical section.
277
278   function C_Gethostbyname
279     (Name     : C.char_array;
280      Ret      : not null access Hostent;
281      Buf      : System.Address;
282      Buflen   : C.int;
283      H_Errnop : not null access C.int) return C.int;
284
285   function C_Gethostbyaddr
286     (Addr      : System.Address;
287      Addr_Len  : C.int;
288      Addr_Type : C.int;
289      Ret       : not null access Hostent;
290      Buf       : System.Address;
291      Buflen    : C.int;
292      H_Errnop  : not null access C.int) return C.int;
293
294   function C_Getservbyname
295     (Name   : C.char_array;
296      Proto  : C.char_array;
297      Ret    : not null access Servent;
298      Buf    : System.Address;
299      Buflen : C.int) return C.int;
300
301   function C_Getservbyport
302     (Port   : C.int;
303      Proto  : C.char_array;
304      Ret    : not null access Servent;
305      Buf    : System.Address;
306      Buflen : C.int) return C.int;
307
308   ------------------------------------
309   -- Scatter/gather vector handling --
310   ------------------------------------
311
312   type Msghdr is record
313      Msg_Name       : System.Address;
314      Msg_Namelen    : C.unsigned;
315      Msg_Iov        : System.Address;
316      Msg_Iovlen     : SOSC.Msg_Iovlen_T;
317      Msg_Control    : System.Address;
318      Msg_Controllen : C.size_t;
319      Msg_Flags      : C.int;
320   end record;
321   pragma Convention (C, Msghdr);
322
323   ----------------------------
324   -- Socket sets management --
325   ----------------------------
326
327   procedure Get_Socket_From_Set
328     (Set    : access Fd_Set;
329      Last   : access C.int;
330      Socket : access C.int);
331   --  Get last socket in Socket and remove it from the socket set. The
332   --  parameter Last is a maximum value of the largest socket. This hint is
333   --  used to avoid scanning very large socket sets. After a call to
334   --  Get_Socket_From_Set, Last is set back to the real largest socket in the
335   --  socket set.
336
337   procedure Insert_Socket_In_Set
338     (Set    : access Fd_Set;
339      Socket : C.int);
340   --  Insert socket in the socket set
341
342   function  Is_Socket_In_Set
343     (Set    : access constant Fd_Set;
344      Socket : C.int) return C.int;
345   --  Check whether Socket is in the socket set, return a non-zero
346   --  value if it is, zero if it is not.
347
348   procedure Last_Socket_In_Set
349     (Set  : access Fd_Set;
350      Last : access C.int);
351   --  Find the largest socket in the socket set. This is needed for select().
352   --  When Last_Socket_In_Set is called, parameter Last is a maximum value of
353   --  the largest socket. This hint is used to avoid scanning very large
354   --  socket sets. After the call, Last is set back to the real largest socket
355   --  in the socket set.
356
357   procedure Remove_Socket_From_Set (Set : access Fd_Set; Socket : C.int);
358   --  Remove socket from the socket set
359
360   procedure Reset_Socket_Set (Set : access Fd_Set);
361   --  Make Set empty
362
363   ------------------------------------------
364   -- Pairs of signalling file descriptors --
365   ------------------------------------------
366
367   type Two_Ints is array (0 .. 1) of C.int;
368   pragma Convention (C, Two_Ints);
369   --  Container for two int values
370
371   subtype Fd_Pair is Two_Ints;
372   --  Two_Ints as used for Create_Signalling_Fds: a pair of connected file
373   --  descriptors, one of which (the "read end" of the connection) being used
374   --  for reading, the other one (the "write end") being used for writing.
375
376   Read_End  : constant := 0;
377   Write_End : constant := 1;
378   --  Indexes into an Fd_Pair value providing access to each of the connected
379   --  file descriptors.
380
381   function Inet_Pton
382     (Af  : C.int;
383      Cp  : System.Address;
384      Inp : System.Address) return C.int;
385
386   function C_Ioctl
387     (Fd  : C.int;
388      Req : SOSC.IOCTL_Req_T;
389      Arg : access C.int) return C.int;
390
391private
392   pragma Import (C, Get_Socket_From_Set, "__gnat_get_socket_from_set");
393   pragma Import (C, Is_Socket_In_Set, "__gnat_is_socket_in_set");
394   pragma Import (C, Last_Socket_In_Set, "__gnat_last_socket_in_set");
395   pragma Import (C, Insert_Socket_In_Set, "__gnat_insert_socket_in_set");
396   pragma Import (C, Remove_Socket_From_Set, "__gnat_remove_socket_from_set");
397   pragma Import (C, Reset_Socket_Set, "__gnat_reset_socket_set");
398   pragma Import (C, C_Ioctl, "__gnat_socket_ioctl");
399   pragma Import (C, Inet_Pton, SOSC.Inet_Pton_Linkname);
400
401   pragma Import (C, C_Gethostbyname, "__gnat_gethostbyname");
402   pragma Import (C, C_Gethostbyaddr, "__gnat_gethostbyaddr");
403   pragma Import (C, C_Getservbyname, "__gnat_getservbyname");
404   pragma Import (C, C_Getservbyport, "__gnat_getservbyport");
405
406   pragma Import (C, Servent_S_Name,  "__gnat_servent_s_name");
407   pragma Import (C, Servent_S_Alias, "__gnat_servent_s_alias");
408   pragma Import (C, Servent_S_Port,  "__gnat_servent_s_port");
409   pragma Import (C, Servent_S_Proto, "__gnat_servent_s_proto");
410
411   pragma Import (C, Hostent_H_Name,     "__gnat_hostent_h_name");
412   pragma Import (C, Hostent_H_Alias,    "__gnat_hostent_h_alias");
413   pragma Import (C, Hostent_H_Addrtype, "__gnat_hostent_h_addrtype");
414   pragma Import (C, Hostent_H_Length,   "__gnat_hostent_h_length");
415   pragma Import (C, Hostent_H_Addr,     "__gnat_hostent_h_addr");
416
417end GNAT.Sockets.Thin_Common;
418