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) 2008-2019, 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;
36with Interfaces.C.Strings;
37
38package GNAT.Sockets.Thin_Common is
39
40   package C renames Interfaces.C;
41   package CS renames C.Strings;
42
43   Success : constant C.int :=  0;
44   Failure : constant C.int := -1;
45
46   type time_t is
47     range -2 ** (8 * SOSC.SIZEOF_tv_sec - 1)
48         .. 2 ** (8 * SOSC.SIZEOF_tv_sec - 1) - 1;
49   for time_t'Size use 8 * SOSC.SIZEOF_tv_sec;
50   pragma Convention (C, time_t);
51
52   type suseconds_t is
53     range -2 ** (8 * SOSC.SIZEOF_tv_usec - 1)
54         .. 2 ** (8 * SOSC.SIZEOF_tv_usec - 1) - 1;
55   for suseconds_t'Size use 8 * SOSC.SIZEOF_tv_usec;
56   pragma Convention (C, suseconds_t);
57
58   type Timeval is record
59      Tv_Sec  : time_t;
60      Tv_Usec : suseconds_t;
61   end record;
62   pragma Convention (C, Timeval);
63
64   type Timeval_Access is access all Timeval;
65   pragma Convention (C, Timeval_Access);
66
67   type socklen_t is mod 2 ** (8 * SOSC.SIZEOF_socklen_t);
68   for socklen_t'Size use (8 * SOSC.SIZEOF_socklen_t);
69
70   Immediat : constant Timeval := (0, 0);
71
72   -------------------------------------------
73   -- Mapping tables to low level constants --
74   -------------------------------------------
75
76   Families : constant array (Family_Type) of C.int :=
77                (Family_Unspec => SOSC.AF_UNSPEC,
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_Unspec => 0,
83                 Family_Inet   => SOSC.SIZEOF_sockaddr_in,
84                 Family_Inet6  => SOSC.SIZEOF_sockaddr_in6);
85
86   ----------------------------
87   -- Generic socket address --
88   ----------------------------
89
90   --  Common header
91
92   --  All socket address types (struct sockaddr, struct sockaddr_storage,
93   --  and protocol specific address types) start with the same 2-byte header,
94   --  which is either a length and a family (one byte each) or just a two-byte
95   --  family. The following unchecked union describes the two possible layouts
96   --  and is meant to be constrained with SOSC.Have_Sockaddr_Len.
97
98   type Sockaddr_Length_And_Family
99     (Has_Sockaddr_Len : Boolean := False)
100   is record
101      case Has_Sockaddr_Len is
102         when True =>
103            Length      : C.unsigned_char;
104            Char_Family : C.unsigned_char;
105
106         when False =>
107            Short_Family : C.unsigned_short;
108      end case;
109   end record;
110   pragma Unchecked_Union (Sockaddr_Length_And_Family);
111   pragma Convention (C, Sockaddr_Length_And_Family);
112
113   procedure Set_Family
114     (Length_And_Family : out Sockaddr_Length_And_Family;
115      Family            : Family_Type);
116   --  Set the family component to the appropriate value for Family, and also
117   --  set Length accordingly if applicable on this platform.
118
119   ----------------------------
120   -- AF_INET socket address --
121   ----------------------------
122
123   type In_Addr is record
124      S_B1, S_B2, S_B3, S_B4 : C.unsigned_char;
125   end record;
126   for In_Addr'Alignment use C.int'Alignment;
127   pragma Convention (C, In_Addr);
128   --  IPv4 address, represented as a network-order C.int. Note that the
129   --  underlying operating system may assume that values of this type have
130   --  C.int alignment, so we need to provide a suitable alignment clause here.
131
132   function To_In_Addr is new Ada.Unchecked_Conversion (C.int, In_Addr);
133   function To_Int     is new Ada.Unchecked_Conversion (In_Addr, C.int);
134
135   function To_In_Addr (Addr : Inet_Addr_Type) return In_Addr;
136   procedure To_Inet_Addr
137     (Addr   : In_Addr;
138      Result : out Inet_Addr_Type);
139   --  Conversion functions
140
141   type In6_Addr is array (1 .. 16) of C.unsigned_char;
142   for In6_Addr'Alignment use C.int'Alignment;
143   pragma Convention (C, In6_Addr);
144
145   function To_In6_Addr (Addr : Inet_Addr_Type) return In6_Addr;
146   procedure To_Inet_Addr
147     (Addr   : In6_Addr;
148      Result : out Inet_Addr_Type);
149   --  Conversion functions
150
151   type Sockaddr (Family : Family_Type := Family_Inet) is record
152      Sin_Family : Sockaddr_Length_And_Family;
153      --  Address family (and address length on some platforms)
154
155      Sin_Port : C.unsigned_short;
156      --  Port in network byte order
157
158      case Family is
159      when Family_Inet =>
160         Sin_Addr : In_Addr := (others => 0);
161         --  IPv4 address
162
163         Sin_Zero : C.char_array (1 .. 8) := (others => C.nul);
164         --  Padding
165         --
166         --  Note that some platforms require that all unused (reserved) bytes
167         --  in addresses be initialized to 0 (e.g. VxWorks).
168      when Family_Inet6 =>
169         Sin6_FlowInfo : Interfaces.Unsigned_32 := 0;
170         Sin6_Addr     : In6_Addr := (others => 0);
171         Sin6_Scope_Id : Interfaces.Unsigned_32 := 0;
172      when Family_Unspec =>
173         null;
174      end case;
175   end record;
176   pragma Unchecked_Union (Sockaddr);
177   pragma Convention (C, Sockaddr);
178   --  Internet socket address
179
180   type Sockaddr_Access is access all Sockaddr;
181   pragma Convention (C, Sockaddr_Access);
182   --  Access to internet socket address
183
184   procedure Set_Address
185     (Sin     : Sockaddr_Access;
186      Address : Sock_Addr_Type);
187   --  Initialise all necessary fields in Sin from Address.
188   --  Set appropriate Family, Port, and either Sin.Sin_Addr or Sin.Sin6_Addr
189   --  depend on family.
190
191   function Get_Address (Sin : Sockaddr) return Sock_Addr_Type;
192   --  Get Sock_Addr_Type from Sockaddr
193
194   ------------------
195   -- Host entries --
196   ------------------
197
198   type Hostent is new
199     System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_struct_hostent);
200   for Hostent'Alignment use 8;
201   --  Host entry. This is an opaque type used only via the following
202   --  accessor functions, because 'struct hostent' has different layouts on
203   --  different platforms.
204
205   type Hostent_Access is access all Hostent;
206   pragma Convention (C, Hostent_Access);
207   --  Access to host entry
208
209   function Hostent_H_Name
210     (E : Hostent_Access) return System.Address;
211
212   function Hostent_H_Alias
213     (E : Hostent_Access; I : C.int) return System.Address;
214
215   function Hostent_H_Addrtype
216     (E : Hostent_Access) return C.int;
217
218   function Hostent_H_Length
219     (E : Hostent_Access) return C.int;
220
221   function Hostent_H_Addr
222     (E : Hostent_Access; Index : C.int) return System.Address;
223
224   ---------------------
225   -- Service entries --
226   ---------------------
227
228   type Servent is new
229     System.Storage_Elements.Storage_Array (1 .. SOSC.SIZEOF_struct_servent);
230   for Servent'Alignment use 8;
231   --  Service entry. This is an opaque type used only via the following
232   --  accessor functions, because 'struct servent' has different layouts on
233   --  different platforms.
234
235   type Servent_Access is access all Servent;
236   pragma Convention (C, Servent_Access);
237   --  Access to service entry
238
239   function Servent_S_Name
240     (E : Servent_Access) return System.Address;
241
242   function Servent_S_Alias
243     (E : Servent_Access; Index : C.int) return System.Address;
244
245   function Servent_S_Port
246     (E : Servent_Access) return C.unsigned_short;
247
248   function Servent_S_Proto
249     (E : Servent_Access) return System.Address;
250
251   ------------------
252   -- NetDB access --
253   ------------------
254
255   --  There are three possible situations for the following NetDB access
256   --  functions:
257   --    - inherently thread safe (case of data returned in a thread specific
258   --      buffer);
259   --    - thread safe using user-provided buffer;
260   --    - thread unsafe.
261   --
262   --  In the first and third cases, the Buf and Buflen are ignored. In the
263   --  second case, the caller must provide a buffer large enough to
264   --  accommodate the returned data. In the third case, the caller must ensure
265   --  that these functions are called within a critical section.
266
267   function C_Gethostbyname
268     (Name     : C.char_array;
269      Ret      : not null access Hostent;
270      Buf      : System.Address;
271      Buflen   : C.int;
272      H_Errnop : not null access C.int) return C.int;
273
274   function C_Gethostbyaddr
275     (Addr      : System.Address;
276      Addr_Len  : C.int;
277      Addr_Type : C.int;
278      Ret       : not null access Hostent;
279      Buf       : System.Address;
280      Buflen    : C.int;
281      H_Errnop  : not null access C.int) return C.int;
282
283   function C_Getservbyname
284     (Name   : C.char_array;
285      Proto  : C.char_array;
286      Ret    : not null access Servent;
287      Buf    : System.Address;
288      Buflen : C.int) return C.int;
289
290   function C_Getservbyport
291     (Port   : C.int;
292      Proto  : C.char_array;
293      Ret    : not null access Servent;
294      Buf    : System.Address;
295      Buflen : C.int) return C.int;
296
297   Address_Size : constant := Standard'Address_Size;
298
299   type Addrinfo;
300   type Addrinfo_Access is access all Addrinfo;
301
302   type Addrinfo is record
303      ai_flags     : C.int;
304      ai_family    : C.int;
305      ai_socktype  : C.int;
306      ai_protocol  : C.int;
307      ai_addrlen   : socklen_t;
308      ai_addr      : Sockaddr_Access;
309      ai_canonname : CS.char_array_access;
310      ai_next      : Addrinfo_Access;
311   end record with Convention => C;
312   for Addrinfo use record
313      ai_flags     at SOSC.AI_FLAGS_OFFSET     range 0 .. C.int'Size - 1;
314      ai_family    at SOSC.AI_FAMILY_OFFSET    range 0 .. C.int'Size - 1;
315      ai_socktype  at SOSC.AI_SOCKTYPE_OFFSET  range 0 .. C.int'Size - 1;
316      ai_protocol  at SOSC.AI_PROTOCOL_OFFSET  range 0 .. C.int'Size - 1;
317      ai_addrlen   at SOSC.AI_ADDRLEN_OFFSET   range 0 .. socklen_t'Size - 1;
318      ai_canonname at SOSC.AI_CANONNAME_OFFSET range 0 .. Address_Size - 1;
319      ai_addr      at SOSC.AI_ADDR_OFFSET      range 0 .. Address_Size - 1;
320      ai_next      at SOSC.AI_NEXT_OFFSET      range 0 .. Address_Size - 1;
321   end record;
322
323   function C_Getaddrinfo
324     (Node    : CS.char_array_access;
325      Service : CS.char_array_access;
326      Hints   : access constant Addrinfo;
327      Res     : not null access Addrinfo_Access) return C.int;
328
329   procedure C_Freeaddrinfo (res : Addrinfo_Access);
330
331   function C_Getnameinfo
332     (sa      : Sockaddr_Access;
333      salen   : socklen_t;
334      host    : CS.char_array_access;
335      hostlen : C.size_t;
336      serv    : CS.char_array_access;
337      servlen : C.size_t;
338      flags   : C.int) return C.int;
339
340   function C_GAI_Strerror (ecode : C.int) return CS.chars_ptr;
341
342   ------------------------------------
343   -- Scatter/gather vector handling --
344   ------------------------------------
345
346   type Msghdr is record
347      Msg_Name       : System.Address;
348      Msg_Namelen    : C.unsigned;
349      Msg_Iov        : System.Address;
350      Msg_Iovlen     : SOSC.Msg_Iovlen_T;
351      Msg_Control    : System.Address;
352      Msg_Controllen : C.size_t;
353      Msg_Flags      : C.int;
354   end record;
355   pragma Convention (C, Msghdr);
356
357   ----------------------------
358   -- Socket sets management --
359   ----------------------------
360
361   procedure Get_Socket_From_Set
362     (Set    : access Fd_Set;
363      Last   : access C.int;
364      Socket : access C.int);
365   --  Get last socket in Socket and remove it from the socket set. The
366   --  parameter Last is a maximum value of the largest socket. This hint is
367   --  used to avoid scanning very large socket sets. After a call to
368   --  Get_Socket_From_Set, Last is set back to the real largest socket in the
369   --  socket set.
370
371   procedure Insert_Socket_In_Set
372     (Set    : access Fd_Set;
373      Socket : C.int);
374   --  Insert socket in the socket set
375
376   function  Is_Socket_In_Set
377     (Set    : access constant Fd_Set;
378      Socket : C.int) return C.int;
379   --  Check whether Socket is in the socket set, return a non-zero
380   --  value if it is, zero if it is not.
381
382   procedure Last_Socket_In_Set
383     (Set  : access Fd_Set;
384      Last : access C.int);
385   --  Find the largest socket in the socket set. This is needed for select().
386   --  When Last_Socket_In_Set is called, parameter Last is a maximum value of
387   --  the largest socket. This hint is used to avoid scanning very large
388   --  socket sets. After the call, Last is set back to the real largest socket
389   --  in the socket set.
390
391   procedure Remove_Socket_From_Set (Set : access Fd_Set; Socket : C.int);
392   --  Remove socket from the socket set
393
394   procedure Reset_Socket_Set (Set : access Fd_Set);
395   --  Make Set empty
396
397   ------------------------------------------
398   -- Pairs of signalling file descriptors --
399   ------------------------------------------
400
401   type Two_Ints is array (0 .. 1) of C.int;
402   pragma Convention (C, Two_Ints);
403   --  Container for two int values
404
405   subtype Fd_Pair is Two_Ints;
406   --  Two_Ints as used for Create_Signalling_Fds: a pair of connected file
407   --  descriptors, one of which (the "read end" of the connection) being used
408   --  for reading, the other one (the "write end") being used for writing.
409
410   Read_End  : constant := 0;
411   Write_End : constant := 1;
412   --  Indexes into an Fd_Pair value providing access to each of the connected
413   --  file descriptors.
414
415   function Inet_Pton
416     (Af  : C.int;
417      Cp  : System.Address;
418      Inp : System.Address) return C.int;
419
420   function Inet_Ntop
421     (Af   : C.int;
422      Src  : System.Address;
423      Dst  : CS.char_array_access;
424      Size : socklen_t) return CS.char_array_access;
425
426   function C_Ioctl
427     (Fd  : C.int;
428      Req : SOSC.IOCTL_Req_T;
429      Arg : access C.int) return C.int;
430
431   function Short_To_Network
432     (S : C.unsigned_short) return C.unsigned_short;
433   pragma Inline (Short_To_Network);
434   --  Convert a port number into a network port number
435
436   function Network_To_Short
437     (S : C.unsigned_short) return C.unsigned_short
438   renames Short_To_Network;
439   --  Symmetric operation
440
441private
442   pragma Import (C, Get_Socket_From_Set, "__gnat_get_socket_from_set");
443   pragma Import (C, Is_Socket_In_Set, "__gnat_is_socket_in_set");
444   pragma Import (C, Last_Socket_In_Set, "__gnat_last_socket_in_set");
445   pragma Import (C, Insert_Socket_In_Set, "__gnat_insert_socket_in_set");
446   pragma Import (C, Remove_Socket_From_Set, "__gnat_remove_socket_from_set");
447   pragma Import (C, Reset_Socket_Set, "__gnat_reset_socket_set");
448   pragma Import (C, C_Ioctl, "__gnat_socket_ioctl");
449   pragma Import (C, Inet_Pton, SOSC.Inet_Pton_Linkname);
450   pragma Import (C, Inet_Ntop, SOSC.Inet_Ntop_Linkname);
451
452   pragma Import (C, C_Gethostbyname, "__gnat_gethostbyname");
453   pragma Import (C, C_Gethostbyaddr, "__gnat_gethostbyaddr");
454   pragma Import (C, C_Getservbyname, "__gnat_getservbyname");
455   pragma Import (C, C_Getservbyport, "__gnat_getservbyport");
456
457   pragma Import (C, C_Getaddrinfo,   "__gnat_getaddrinfo");
458   pragma Import (C, C_Freeaddrinfo,  "__gnat_freeaddrinfo");
459   pragma Import (C, C_Getnameinfo,   "__gnat_getnameinfo");
460   pragma Import (C, C_GAI_Strerror,  "__gnat_gai_strerror");
461
462   pragma Import (C, Servent_S_Name,  "__gnat_servent_s_name");
463   pragma Import (C, Servent_S_Alias, "__gnat_servent_s_alias");
464   pragma Import (C, Servent_S_Port,  "__gnat_servent_s_port");
465   pragma Import (C, Servent_S_Proto, "__gnat_servent_s_proto");
466
467   pragma Import (C, Hostent_H_Name,     "__gnat_hostent_h_name");
468   pragma Import (C, Hostent_H_Alias,    "__gnat_hostent_h_alias");
469   pragma Import (C, Hostent_H_Addrtype, "__gnat_hostent_h_addrtype");
470   pragma Import (C, Hostent_H_Length,   "__gnat_hostent_h_length");
471   pragma Import (C, Hostent_H_Addr,     "__gnat_hostent_h_addr");
472
473end GNAT.Sockets.Thin_Common;
474