text: /* Copyright (C) 1996-2004,2006,2007,2009,2010 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, see
     <http://www.gnu.org/licenses/>.  */
  
  #include <assert.h>
  #include <atomic.h>
  #include <errno.h>
  #include <stdbool.h>
  #include "nsswitch.h"
  #include "sysdep.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 parameters, can vary in number	   *|
  |*								   *|
  |* ADD_VARIABLES - names of additional parameters		   *|
  |*								   *|
  |* Optionally the following vars can be defined:		   *|
  |*								   *|
  |* EXTRA_PARAMS  - optional parameters, can vary in number	   *|
  |*								   *|
  |* EXTRA_VARIABLES - names of optional parameter		   *|
  |*								   *|
  |* FUNCTION_NAME - alternative name of the non-reentrant function  *|
  |*								   *|
  |* 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)
  #ifdef FUNCTION2_NAME
  # define REENTRANT2_NAME APPEND_R (FUNCTION2_NAME)
  #else
  # define REENTRANT2_NAME NULL
  #endif
  #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
  # define CONCAT2(arg1, arg2) CONCAT2_2 (arg1, arg2)
  # define CONCAT2_2(arg1, arg2) arg1##arg2
  #endif
  
  #define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
  #define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
  #ifdef FUNCTION2_NAME
  # define REENTRANT2_NAME_STRING STRINGIZE (REENTRANT2_NAME)
  #else
  # define REENTRANT2_NAME_STRING NULL
  #endif
  #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, _lookup2)
  # 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 EXTRA_PARAMS
  # define EXTRA_PARAMS
  #endif
  #ifndef EXTRA_VARIABLES
  # define EXTRA_VARIABLES
  #endif
  
  #ifdef HAVE_AF
  # define AF_VAL af
  #else
  # define AF_VAL AF_INET
  #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
  					    EXTRA_PARAMS);
  
  /* The lookup function for the first entry of this service.  */
  extern int DB_LOOKUP_FCT (service_user **nip, const char *name,
  			  const char *name2, void **fctp)
       internal_function;
  libc_hidden_proto (DB_LOOKUP_FCT)
  
  
  int
  INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
  			   size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM
  			   EXTRA_PARAMS)
  {
    static bool startp_initialized;
    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, AF_VAL,
  				      H_ERRNO_VAR_P))
      {
      case -1:
        return errno;
      case 1:
        goto done;
      }
  #endif
  
  #ifdef USE_NSCD
    if (NOT_USENSCD_NAME > 0 && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY)
      NOT_USENSCD_NAME = 0;
  
    if (!NOT_USENSCD_NAME
        && !__nss_database_custom[CONCAT2 (NSS_DBSIDX_, DATABASE_NAME)])
      {
        nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen, result
  			       H_ERRNO_VAR);
        if (nscd_status >= 0)
  	return nscd_status;
      }
  #endif
  
    if (! startp_initialized)
      {
        no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING,
  			       REENTRANT2_NAME_STRING, &fct.ptr);
        if (no_more)
  	{
  	  void *tmp_ptr = (service_user *) -1l;
  	  PTR_MANGLE (tmp_ptr);
  	  startp = tmp_ptr;
  	}
        else
  	{
  #ifdef NEED__RES
  	  /* The resolver code will really be used so we have to
  	     initialize it.  */
  	  if (__res_maybe_init (&_res, 0) == -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 */
  
  	  void *tmp_ptr = fct.l;
  	  PTR_MANGLE (tmp_ptr);
  	  start_fct = tmp_ptr;
  	  tmp_ptr = nip;
  	  PTR_MANGLE (tmp_ptr);
  	  startp = tmp_ptr;
  	}
  
        /* Make sure start_fct and startp are written before
  	 startp_initialized.  */
        atomic_write_barrier ();
        startp_initialized = true;
      }
    else
      {
        fct.l = start_fct;
        PTR_DEMANGLE (fct.l);
        nip = startp;
        PTR_DEMANGLE (nip);
        no_more = nip == (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 EXTRA_VARIABLES));
  
        /* 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_next2 (&nip, REENTRANT_NAME_STRING,
  			     REENTRANT2_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
  
    int res;
    if (status == NSS_STATUS_SUCCESS || status == NSS_STATUS_NOTFOUND)
      res = 0;
    /* Don't pass back ERANGE if this is not for a too-small buffer.  */
    else if (errno == ERANGE && status != NSS_STATUS_TRYAGAIN)
      res = EINVAL;
  #ifdef NEED_H_ERRNO
    /* These functions only set errno if h_errno is NETDB_INTERNAL.  */
    else if (status == NSS_STATUS_TRYAGAIN && *h_errnop != NETDB_INTERNAL)
      res = EAGAIN;
  #endif
    else
      return errno;
  
    __set_errno (res);
    return res;
  }
  
  
  #ifdef NO_COMPAT_NEEDED
  strong_alias (INTERNAL (REENTRANT_NAME), REENTRANT_NAME);
  #elif !defined FUNCTION2_NAME
  # 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
  attribute_compat_text_section
  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 || result == NULL)
      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);
  #endif
  
  static_link_warning (REENTRANT_NAME)
  