1 /* Copyright (C) 1996-2013 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
26 # include <nscd/nscd_proto.h>
28 #ifdef NEED__RES_HCONF
29 # include <resolv/res_hconf.h>
34 /*******************************************************************\
35 |* Here we assume several symbols to be defined: *|
37 |* LOOKUP_TYPE - the return type of the function *|
39 |* FUNCTION_NAME - name of the non-reentrant function *|
41 |* DATABASE_NAME - name of the database the function accesses *|
42 |* (e.g., host, services, ...) *|
44 |* ADD_PARAMS - additional parameters, can vary in number *|
46 |* ADD_VARIABLES - names of additional parameters *|
48 |* Optionally the following vars can be defined: *|
50 |* EXTRA_PARAMS - optional parameters, can vary in number *|
52 |* EXTRA_VARIABLES - names of optional parameter *|
54 |* FUNCTION2_NAME - alternative name of the non-reentrant function *|
56 |* NEED_H_ERRNO - an extra parameter will be passed to point to *|
57 |* the global `h_errno' variable. *|
59 |* NEED__RES - the global _res variable might be used so we *|
60 |* will have to initialize it if necessary *|
62 |* PREPROCESS - code run before anything else *|
64 |* POSTPROCESS - code run after the lookup *|
66 \*******************************************************************/
68 /* To make the real sources a bit prettier. */
69 #define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
71 # define REENTRANT2_NAME APPEND_R (FUNCTION2_NAME)
73 # define REENTRANT2_NAME NULL
75 #define APPEND_R(name) APPEND_R1 (name)
76 #define APPEND_R1(name) name##_r
77 #define INTERNAL(name) INTERNAL1 (name)
78 #define INTERNAL1(name) __##name
79 #define NEW(name) NEW1 (name)
80 #define NEW1(name) __new_##name
83 # define NSCD_NAME ADD_NSCD (REENTRANT_NAME)
84 # define ADD_NSCD(name) ADD_NSCD1 (name)
85 # define ADD_NSCD1(name) __nscd_##name
86 # define NOT_USENSCD_NAME ADD_NOT_NSCDUSE (DATABASE_NAME)
87 # define ADD_NOT_NSCDUSE(name) ADD_NOT_NSCDUSE1 (name)
88 # define ADD_NOT_NSCDUSE1(name) __nss_not_use_nscd_##name
89 # define CONCAT2(arg1, arg2) CONCAT2_2 (arg1, arg2)
90 # define CONCAT2_2(arg1, arg2) arg1##arg2
93 #define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
94 #define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
96 # define REENTRANT2_NAME_STRING STRINGIZE (REENTRANT2_NAME)
98 # define REENTRANT2_NAME_STRING NULL
100 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
101 #define STRINGIZE(name) STRINGIZE1 (name)
102 #define STRINGIZE1(name) #name
104 #ifndef DB_LOOKUP_FCT
105 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2)
106 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
107 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
110 /* Sometimes we need to store error codes in the `h_errno' variable. */
112 # define H_ERRNO_PARM , int *h_errnop
113 # define H_ERRNO_VAR , h_errnop
114 # define H_ERRNO_VAR_P h_errnop
116 # define H_ERRNO_PARM
118 # define H_ERRNO_VAR_P NULL
122 # define EXTRA_PARAMS
124 #ifndef EXTRA_VARIABLES
125 # define EXTRA_VARIABLES
131 # define AF_VAL AF_INET
134 /* Type of the lookup function we need here. */
135 typedef enum nss_status (*lookup_function
) (ADD_PARAMS
, LOOKUP_TYPE
*, char *,
136 size_t, int * H_ERRNO_PARM
139 /* The lookup function for the first entry of this service. */
140 extern int DB_LOOKUP_FCT (service_user
**nip
, const char *name
,
141 const char *name2
, void **fctp
)
143 libc_hidden_proto (DB_LOOKUP_FCT
)
147 INTERNAL (REENTRANT_NAME
) (ADD_PARAMS
, LOOKUP_TYPE
*resbuf
, char *buffer
,
148 size_t buflen
, LOOKUP_TYPE
**result H_ERRNO_PARM
151 static bool startp_initialized
;
152 static service_user
*startp
;
153 static lookup_function start_fct
;
162 enum nss_status status
= NSS_STATUS_UNAVAIL
;
167 bool any_service
= false;
174 #ifdef HANDLE_DIGITS_DOTS
175 switch (__nss_hostname_digits_dots (name
, resbuf
, &buffer
, NULL
,
176 buflen
, result
, &status
, AF_VAL
,
190 if (NOT_USENSCD_NAME
> 0 && ++NOT_USENSCD_NAME
> NSS_NSCD_RETRY
)
191 NOT_USENSCD_NAME
= 0;
193 if (!NOT_USENSCD_NAME
194 && !__nss_database_custom
[CONCAT2 (NSS_DBSIDX_
, DATABASE_NAME
)])
196 nscd_status
= NSCD_NAME (ADD_VARIABLES
, resbuf
, buffer
, buflen
, result
198 if (nscd_status
>= 0)
203 if (! startp_initialized
)
205 no_more
= DB_LOOKUP_FCT (&nip
, REENTRANT_NAME_STRING
,
206 REENTRANT2_NAME_STRING
, &fct
.ptr
);
209 void *tmp_ptr
= (service_user
*) -1l;
211 PTR_MANGLE (tmp_ptr
);
218 /* The resolver code will really be used so we have to
220 if (__res_maybe_init (&_res
, 0) == -1)
222 *h_errnop
= NETDB_INTERNAL
;
226 #endif /* need _res */
227 #ifdef NEED__RES_HCONF
228 if (!_res_hconf
.initialized
)
230 #endif /* need _res_hconf */
232 void *tmp_ptr
= fct
.l
;
234 PTR_MANGLE (tmp_ptr
);
239 PTR_MANGLE (tmp_ptr
);
244 /* Make sure start_fct and startp are written before
245 startp_initialized. */
246 atomic_write_barrier ();
247 startp_initialized
= true;
254 PTR_DEMANGLE (fct
.l
);
257 no_more
= nip
== (service_user
*) -1l;
266 status
= DL_CALL_FCT (fct
.l
, (ADD_VARIABLES
, resbuf
, buffer
, buflen
,
267 &errno H_ERRNO_VAR EXTRA_VARIABLES
));
269 /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
270 provided buffer is too small. In this case we should give
271 the user the possibility to enlarge the buffer and we should
272 not simply go on with the next service (even if the TRYAGAIN
273 action tells us so). */
274 if (status
== NSS_STATUS_TRYAGAIN
276 && *h_errnop
== NETDB_INTERNAL
281 no_more
= __nss_next2 (&nip
, REENTRANT_NAME_STRING
,
282 REENTRANT2_NAME_STRING
, &fct
.ptr
, status
, 0);
285 #ifdef HANDLE_DIGITS_DOTS
288 *result
= status
== NSS_STATUS_SUCCESS
? resbuf
: NULL
;
290 if (status
== NSS_STATUS_UNAVAIL
)
291 /* Either we failed to lookup the functions or the functions themselves
292 had a system error. Set NETDB_INTERNAL here to let the caller know
293 that the errno may have the real reason for failure. */
294 *h_errnop
= NETDB_INTERNAL
;
295 else if (status
!= NSS_STATUS_SUCCESS
&& !any_service
)
296 /* We were not able to use any service. */
297 *h_errnop
= NO_RECOVERY
;
304 if (status
== NSS_STATUS_SUCCESS
|| status
== NSS_STATUS_NOTFOUND
)
306 /* Don't pass back ERANGE if this is not for a too-small buffer. */
307 else if (errno
== ERANGE
&& status
!= NSS_STATUS_TRYAGAIN
)
310 /* These functions only set errno if h_errno is NETDB_INTERNAL. */
311 else if (status
== NSS_STATUS_TRYAGAIN
&& *h_errnop
!= NETDB_INTERNAL
)
322 #ifdef NO_COMPAT_NEEDED
323 strong_alias (INTERNAL (REENTRANT_NAME
), REENTRANT_NAME
);
324 #elif !defined FUNCTION2_NAME
325 # include <shlib-compat.h>
326 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
327 # define OLD(name) OLD1 (name)
328 # define OLD1(name) __old_##name
331 attribute_compat_text_section
332 OLD (REENTRANT_NAME
) (ADD_PARAMS
, LOOKUP_TYPE
*resbuf
, char *buffer
,
333 size_t buflen
, LOOKUP_TYPE
**result H_ERRNO_PARM
)
335 int ret
= INTERNAL (REENTRANT_NAME
) (ADD_VARIABLES
, resbuf
, buffer
,
336 buflen
, result H_ERRNO_VAR
);
338 if (ret
!= 0 || result
== NULL
)
344 # define do_symbol_version(real, name, version) \
345 compat_symbol (libc, real, name, version)
346 do_symbol_version (OLD (REENTRANT_NAME
), REENTRANT_NAME
, GLIBC_2_0
);
349 /* As INTERNAL (REENTRANT_NAME) may be hidden, we need an alias
350 in between so that the REENTRANT_NAME@@GLIBC_2.1.2 is not
352 strong_alias (INTERNAL (REENTRANT_NAME
), NEW (REENTRANT_NAME
));
354 # define do_default_symbol_version(real, name, version) \
355 versioned_symbol (libc, real, name, version)
356 do_default_symbol_version (NEW (REENTRANT_NAME
),
357 REENTRANT_NAME
, GLIBC_2_1_2
);
360 nss_interface_function (REENTRANT_NAME
)