about summary refs log tree commit diff
path: root/nss/getXXbyYY_r.c
blob: d85169ab812c54cba38cb56519bcd08cc35454ae (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/* Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "nsswitch.h"

/*******************************************************************\
|* Here we assume several symbols to be defined:		   *|
|* 								   *|
|* LOOKUP_TYPE   - the return type of the function		   *|
|* 								   *|
|* FUNCTION_NAME - name of the non-reentrant function		   *|
|* 								   *|
|* DATABASE_NAME - name of the database the function accesses	   *|
|*		   (e.g., host, services, ...)			   *|
|* 								   *|
|* ADD_PARAMS    - additional parameter, can vary in number	   *|
|* 								   *|
|* ADD_VARIABLES - names of additional parameter		   *|
|* 								   *|
|* Optionally the following vars can be defined:		   *|
|* 								   *|
|* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
|*		   the global `h_errno' variable.		   *|
|* 								   *|
|* NEED__RES     - the global _res variable might be used so we	   *|
|* 		   will have to initialize it if necessary	   *|
|* 								   *|
\*******************************************************************/

/* To make the real sources a bit prettier.  */
#define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name

#define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
#define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
#define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
#define STRINGIZE(name) STRINGIZE1 (name)
#define STRINGIZE1(name) #name

#define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
#define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
#define CONCAT3_2(Pre, Name, Post) Pre##Name##Post

/* Sometimes we need to store error codes in the `h_errno' variable.  */
#ifdef NEED_H_ERRNO
# define H_ERRNO_PARM , int *h_errnop
# define H_ERRNO_VAR , h_errnop
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
#endif


/* Type of the lookup function we need here.  */
typedef int (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *, int
				H_ERRNO_PARM);

/* Some usages of this file might use this variable.  */
extern struct __res_state _res;

/* The lookup function for the first entry of this service.  */
extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp);



int
INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
			   size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
{
  static service_user *startp = NULL;
  static lookup_function start_fct;
  service_user *nip;
  lookup_function fct;
  int no_more;
  enum nss_status status = NSS_STATUS_UNAVAIL;

  if (startp == NULL)
    {
      no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, (void **) &fct);
      if (no_more)
	startp = (service_user *) -1;
      else
	{
	  startp = nip;
	  start_fct = fct;

#ifdef NEED__RES
	  /* The resolver code will really be used so we have to
	     initialize it.  */
	  if ((_res.options & RES_INIT) == 0 && res_init () == -1)
	    {
	      *h_errnop = NETDB_INTERNAL;
	      return NULL;
	    }
#endif /* need _res */
	}
    }
  else
    {
      fct = start_fct;
      no_more = (nip = startp) == (service_user *) -1;
    }

  while (no_more == 0)
    {
      status = (*fct) (ADD_VARIABLES, resbuf, buffer, buflen H_ERRNO_VAR);

      no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
			    (void **) &fct, status, 0);
    }

  *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
  return status == NSS_STATUS_SUCCESS ? 0 : -1;
}

#define do_weak_alias(n1, n2) weak_alias ((n1), (n2))
do_weak_alias (INTERNAL (REENTRANT_NAME), REENTRANT_NAME)