aboutsummaryrefslogtreecommitdiff
path: root/nss/getXXbyYY_r.c
blob: 5bb28f71415098b55db5cf35e8942d160804d34b (plain)
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/* Copyright (C) 1996,97,98,99,2000,2001,2002 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

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

#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include "nsswitch.h"
#ifdef USE_NSCD
# include <nscd/nscd_proto.h>
#endif
#ifdef NEED__RES_HCONF
# include <resolv/res_hconf.h>
#endif
#ifdef NEED__RES
# include <resolv.h>
#endif
/*******************************************************************\
|* 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	   *|
|*								   *|
|* PREPROCESS    - code run before anything else		   *|
|*								   *|
|* POSTPROCESS   - code run after the lookup			   *|
|*								   *|
\*******************************************************************/

/* 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 NEW(name) NEW1 (name)
#define NEW1(name) __new_##name

#ifdef USE_NSCD
# define NSCD_NAME ADD_NSCD (REENTRANT_NAME)
# define ADD_NSCD(name) ADD_NSCD1 (name)
# define ADD_NSCD1(name) __nscd_##name
# define NOT_USENSCD_NAME ADD_NOT_NSCDUSE (DATABASE_NAME)
# define ADD_NOT_NSCDUSE(name) ADD_NOT_NSCDUSE1 (name)
# define ADD_NOT_NSCDUSE1(name) __nss_not_use_nscd_##name
#endif

#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

#ifndef DB_LOOKUP_FCT
# 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
#endif

/* 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
# define H_ERRNO_VAR_P h_errnop
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
# define H_ERRNO_VAR_P NULL
#endif

#ifndef HAVE_TYPE
# define TYPE_VAR_P NULL
# define FLAGS_VAR 0
#endif

#ifdef HAVE_AF
# define AF_VAR_P &af
#else
# define AF_VAR_P NULL
#endif

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

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

/* Interval in which we transfer retry to contact the NSCD.  */
#define NSS_NSCD_RETRY	100


int
INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
			   size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
{
  static service_user *startp;
  static lookup_function start_fct;
  service_user *nip;
  union
  {
    lookup_function l;
    void *ptr;
  } fct;

  int no_more;
  enum nss_status status = NSS_STATUS_UNAVAIL;
#ifdef USE_NSCD
  int nscd_status;
#endif
#ifdef NEED_H_ERRNO
  bool any_service = false;
#endif

#ifdef PREPROCESS
  PREPROCESS;
#endif

#ifdef HANDLE_DIGITS_DOTS
  switch (__nss_hostname_digits_dots (name, resbuf, &buffer, NULL,
				      buflen, result, &status,
				      TYPE_VAR_P, FLAGS_VAR, AF_VAR_P,
				      H_ERRNO_VAR_P))
    {
    case -1:
      return errno;
    case 1:
      goto done;
    }
#endif

#ifdef USE_NSCD
  if (NOT_USENSCD_NAME && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY)
    NOT_USENSCD_NAME = 0;

  if (!NOT_USENSCD_NAME)
    {
      nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen
			       H_ERRNO_VAR);
      if (nscd_status >= 0)
	{
	  *result = nscd_status == 0 ? resbuf : NULL;
	  return nscd_status;
	}
    }
#endif

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

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

  while (no_more == 0)
    {
#ifdef NEED_H_ERRNO
      any_service = true;
#endif

      status = DL_CALL_FCT (fct.l, (ADD_VARIABLES, resbuf, buffer, buflen,
				    &errno H_ERRNO_VAR));

      /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
	 provided buffer is too small.  In this case we should give
	 the user the possibility to enlarge the buffer and we should
	 not simply go on with the next service (even if the TRYAGAIN
	 action tells us so).  */
      if (status == NSS_STATUS_TRYAGAIN
#ifdef NEED_H_ERRNO
	  && *h_errnop == NETDB_INTERNAL
#endif
	  && errno == ERANGE)
	break;

      no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
			    &fct.ptr, status, 0);
    }

#ifdef HANDLE_DIGITS_DOTS
done:
#endif
  *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
#ifdef NEED_H_ERRNO
  if (status != NSS_STATUS_SUCCESS && ! any_service)
    /* We were not able to use any service.  */
    *h_errnop = NO_RECOVERY;
#endif
#ifdef POSTPROCESS
  POSTPROCESS;
#endif
  return (status == NSS_STATUS_SUCCESS ? 0
	  : status != NSS_STATUS_TRYAGAIN ? ENOENT
#ifdef NEED_H_ERRNO
	  /* These functions only set errno if h_errno is NETDB_INTERNAL.  */
	  : *h_errnop != NETDB_INTERNAL ? EAGAIN
#endif
	  : errno);
}


#include <shlib-compat.h>
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
#define OLD(name) OLD1 (name)
#define OLD1(name) __old_##name

int
OLD (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
		      size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
{
  int ret = INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, resbuf, buffer,
				       buflen, result H_ERRNO_VAR);

  if (ret != 0)
    ret = -1;

  return ret;
}

#define do_symbol_version(real, name, version) \
  compat_symbol (libc, real, name, version)
do_symbol_version (OLD (REENTRANT_NAME), REENTRANT_NAME, GLIBC_2_0);
#endif

/* As INTERNAL (REENTRANT_NAME) may be hidden, we need an alias
   in between so that the REENTRANT_NAME@@GLIBC_2.1.2 is not
   hidden too.  */
strong_alias (INTERNAL (REENTRANT_NAME), NEW (REENTRANT_NAME));

#define do_default_symbol_version(real, name, version) \
  versioned_symbol (libc, real, name, version)
do_default_symbol_version (NEW (REENTRANT_NAME),
			   REENTRANT_NAME, GLIBC_2_1_2);