/* Copyright (C) 1996-2018 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 <ctype.h>

#include <dlfcn.h>

#include <errno.h>

#include <netdb.h>

#include <libc-lock.h>

#include <search.h>

#include <stdio.h>

#include <stdio_ext.h>

#include <stdlib.h>

#include <string.h>

#include <aliases.h>

#include <grp.h>

#include <netinet/ether.h>

#include <pwd.h>

#include <shadow.h>

#if !defined DO_STATIC_NSS || defined SHARED

# include <gnu/lib-names.h>

#endif

#include "nsswitch.h"

#include "../nscd/nscd_proto.h"

#include <sysdep.h>

#include <config.h>

#ifdef LINK_OBSOLETE_NSL

# define DEFAULT_CONFIG    "compat [NOTFOUND=return] files"

# define DEFAULT_DEFCONFIG "nis [NOTFOUND=return] files"

#else

# define DEFAULT_CONFIG    "files"

# define DEFAULT_DEFCONFIG "files"

#endif

/* Prototypes for the local functions.  */

static name_database *nss_parse_file (const char *fname);

static name_database_entry *nss_getline (char *line);

static service_user *nss_parse_service_list (const char *line);

#if !defined DO_STATIC_NSS || defined SHARED

static service_library *nss_new_service (name_database *database,

					 const char *name);

#endif

/* Declare external database variables.  */

#define DEFINE_DATABASE(name)						      \

  service_user *__nss_##name##_database attribute_hidden;		      \

  weak_extern (__nss_##name##_database)

#include "databases.def"

#undef DEFINE_DATABASE

/* Structure to map database name to variable.  */

static const struct

{

  const char name[10];

  service_user **dbp;

} databases[] =

{

#define DEFINE_DATABASE(name)						      \

  { #name, &__nss_##name##_database },

#include "databases.def"

#undef DEFINE_DATABASE

};

#define ndatabases (sizeof (databases) / sizeof (databases[0]))

#ifdef USE_NSCD

/* Flags whether custom rules for database is set.  */

bool __nss_database_custom[NSS_DBSIDX_max];

#endif

__libc_lock_define_initialized (static, lock)

#if !defined DO_STATIC_NSS || defined SHARED

/* String with revision number of the shared object files.  */

static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;

#endif

/* The root of the whole data base.  */

static name_database *service_table;

/* List of default service lists that were generated by glibc because

   /etc/nsswitch.conf did not provide a value.

   The list is only maintained so we can free such service lists in

   __libc_freeres.  */

static name_database_entry *defconfig_entries;

#if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)

/* Nonzero if this is the nscd process.  */

static bool is_nscd;

/* The callback passed to the init functions when nscd is used.  */

static void (*nscd_init_cb) (size_t, struct traced_file *);

#endif

/* -1 == database not found

    0 == database entry pointer stored */

int

__nss_database_lookup2 (const char *database, const char *alternate_name,

			const char *defconfig, service_user **ni)

{

  /* Prevent multiple threads to change the service table.  */

  __libc_lock_lock (lock);

  /* Reconsider database variable in case some other thread called

     `__nss_configure_lookup' while we waited for the lock.  */

  if (*ni != NULL)

    {

      __libc_lock_unlock (lock);

      return 0;

    }

  /* Are we initialized yet?  */

  if (service_table == NULL)

    /* Read config file.  */

    service_table = nss_parse_file (_PATH_NSSWITCH_CONF);

  /* Test whether configuration data is available.  */

  if (service_table != NULL)

    {

      /* Return first `service_user' entry for DATABASE.  */

      name_database_entry *entry;

      /* XXX Could use some faster mechanism here.  But each database is

	 only requested once and so this might not be critical.  */

      for (entry = service_table->entry; entry != NULL; entry = entry->next)

	if (strcmp (database, entry->name) == 0)

	  *ni = entry->service;

      if (*ni == NULL && alternate_name != NULL)

	/* We haven't found an entry so far.  Try to find it with the

	   alternative name.  */

	for (entry = service_table->entry; entry != NULL; entry = entry->next)

	  if (strcmp (alternate_name, entry->name) == 0)

	    *ni = entry->service;

    }

  /* No configuration data is available, either because nsswitch.conf

     doesn't exist or because it doesn't have a line for this database.

     DEFCONFIG specifies the default service list for this database,

     or null to use the most common default.  */

  if (*ni == NULL)

    {

      *ni = nss_parse_service_list (defconfig ?: DEFAULT_DEFCONFIG);

      if (*ni != NULL)

	{

	  /* Record the memory we've just allocated in defconfig_entries list,

	     so we can free it later.  */

	  name_database_entry *entry;

	  /* Allocate ENTRY plus size of name (1 here).  */

	  entry = (name_database_entry *) malloc (sizeof (*entry) + 1);

	  if (entry != NULL)

	    {

	      entry->next = defconfig_entries;

	      entry->service = *ni;

	      entry->name[0] = '\0';

	      defconfig_entries = entry;

	    }

	}

    }

  __libc_lock_unlock (lock);

  return *ni != NULL ? 0 : -1;

}

libc_hidden_def (__nss_database_lookup2)

/* -1 == not found

    0 == function found

    1 == finished */

int

__nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,

	      void **fctp)

{

  *fctp = __nss_lookup_function (*ni, fct_name);

  if (*fctp == NULL && fct2_name != NULL)

    *fctp = __nss_lookup_function (*ni, fct2_name);

  while (*fctp == NULL

	 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE

	 && (*ni)->next != NULL)

    {

      *ni = (*ni)->next;

      *fctp = __nss_lookup_function (*ni, fct_name);

      if (*fctp == NULL && fct2_name != NULL)

	*fctp = __nss_lookup_function (*ni, fct2_name);

    }

  return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;

}

libc_hidden_def (__nss_lookup)

/* -1 == not found

    0 == adjusted for next function

    1 == finished */

int

__nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,

	     void **fctp, int status, int all_values)

{

  if (all_values)

    {

      if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN

	  && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN

	  && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN

	  && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)

	return 1;

    }

  else

    {

      /* This is really only for debugging.  */

      if (__builtin_expect (NSS_STATUS_TRYAGAIN > status

			    || status > NSS_STATUS_RETURN, 0))

	 __libc_fatal ("Illegal status in __nss_next.\n");

       if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)

	 return 1;

    }

  if ((*ni)->next == NULL)

    return -1;

  do

    {

      *ni = (*ni)->next;

      *fctp = __nss_lookup_function (*ni, fct_name);

      if (*fctp == NULL && fct2_name != NULL)

	*fctp = __nss_lookup_function (*ni, fct2_name);

    }

  while (*fctp == NULL

	 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE

	 && (*ni)->next != NULL);

  return *fctp != NULL ? 0 : -1;

}

libc_hidden_def (__nss_next2)

int

__nss_configure_lookup (const char *dbname, const char *service_line)

{

  service_user *new_db;

  size_t cnt;

  for (cnt = 0; cnt < ndatabases; ++cnt)

    {

      int cmp = strcmp (dbname, databases[cnt].name);

      if (cmp == 0)

	break;

      if (cmp < 0)

	{

	  __set_errno (EINVAL);

	  return -1;

	}

    }

  if (cnt == ndatabases)

    {

      __set_errno (EINVAL);

      return -1;

    }

  /* Test whether it is really used.  */

  if (databases[cnt].dbp == NULL)

    /* Nothing to do, but we could do.  */

    return 0;

  /* Try to generate new data.  */

  new_db = nss_parse_service_list (service_line);

  if (new_db == NULL)

    {

      /* Illegal service specification.  */

      __set_errno (EINVAL);

      return -1;

    }

  /* Prevent multiple threads to change the service table.  */

  __libc_lock_lock (lock);

  /* Install new rules.  */

  *databases[cnt].dbp = new_db;

#ifdef USE_NSCD

  __nss_database_custom[cnt] = true;

#endif

  __libc_lock_unlock (lock);

  return 0;

}

/* Comparison function for searching NI->known tree.  */

static int

known_compare (const void *p1, const void *p2)

{

  return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,

				*(const char *const *) p2);

}

#if !defined DO_STATIC_NSS || defined SHARED

/* Load library.  */

static int

nss_load_library (service_user *ni)

{

  if (ni->library == NULL)

    {

      /* This service has not yet been used.  Fetch the service

	 library for it, creating a new one if need be.  If there

	 is no service table from the file, this static variable

	 holds the head of the service_library list made from the

	 default configuration.  */

      static name_database default_table;

      ni->library = nss_new_service (service_table ?: &default_table,

				     ni->name);

      if (ni->library == NULL)

	return -1;

    }

  if (ni->library->lib_handle == NULL)

    {

      /* Load the shared library.  */

      size_t shlen = (7 + strlen (ni->name) + 3

		      + strlen (__nss_shlib_revision) + 1);

      int saved_errno = errno;

      char shlib_name[shlen];

      /* Construct shared object name.  */

      __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,

					      "libnss_"),

				    ni->name),

			  ".so"),

		__nss_shlib_revision);

      ni->library->lib_handle = __libc_dlopen (shlib_name);

      if (ni->library->lib_handle == NULL)

	{

	  /* Failed to load the library.  */

	  ni->library->lib_handle = (void *) -1l;

	  __set_errno (saved_errno);

	}

# ifdef USE_NSCD

      else if (is_nscd)

	{

	  /* Call the init function when nscd is used.  */

	  size_t initlen = (5 + strlen (ni->name)

			    + strlen ("_init") + 1);

	  char init_name[initlen];

	  /* Construct the init function name.  */

	  __stpcpy (__stpcpy (__stpcpy (init_name,

					"_nss_"),

			      ni->name),

		    "_init");

	  /* Find the optional init function.  */

	  void (*ifct) (void (*) (size_t, struct traced_file *))

	    = __libc_dlsym (ni->library->lib_handle, init_name);

	  if (ifct != NULL)

	    {

	      void (*cb) (size_t, struct traced_file *) = nscd_init_cb;

#  ifdef PTR_DEMANGLE

	      PTR_DEMANGLE (cb);

#  endif

	      ifct (cb);

	    }

	}

# endif

    }

  return 0;

}

#endif

void *

__nss_lookup_function (service_user *ni, const char *fct_name)

{

  void **found, *result;

  /* We now modify global data.  Protect it.  */

  __libc_lock_lock (lock);

  /* Search the tree of functions previously requested.  Data in the

     tree are `known_function' structures, whose first member is a

     `const char *', the lookup key.  The search returns a pointer to

     the tree node structure; the first member of the is a pointer to

     our structure (i.e. what will be a `known_function'); since the

     first member of that is the lookup key string, &FCT_NAME is close

     enough to a pointer to our structure to use as a lookup key that

     will be passed to `known_compare' (above).  */

  found = __tsearch (&fct_name, &ni->known, &known_compare);

  if (found == NULL)

    /* This means out-of-memory.  */

    result = NULL;

  else if (*found != &fct_name)

    {

      /* The search found an existing structure in the tree.  */

      result = ((known_function *) *found)->fct_ptr;

#ifdef PTR_DEMANGLE

      PTR_DEMANGLE (result);

#endif

    }

  else

    {

      /* This name was not known before.  Now we have a node in the tree

	 (in the proper sorted position for FCT_NAME) that points to

	 &FCT_NAME instead of any real `known_function' structure.

	 Allocate a new structure and fill it in.  */

      known_function *known = malloc (sizeof *known);

      if (! known)

	{

#if !defined DO_STATIC_NSS || defined SHARED

	remove_from_tree:

#endif

	  /* Oops.  We can't instantiate this node properly.

	     Remove it from the tree.  */

	  __tdelete (&fct_name, &ni->known, &known_compare);

	  free (known);

	  result = NULL;

	}

      else

	{

	  /* Point the tree node at this new structure.  */

	  *found = known;

	  known->fct_name = fct_name;

#if !defined DO_STATIC_NSS || defined SHARED

	  /* Load the appropriate library.  */

	  if (nss_load_library (ni) != 0)

	    /* This only happens when out of memory.  */

	    goto remove_from_tree;

	  if (ni->library->lib_handle == (void *) -1l)

	    /* Library not found => function not found.  */

	    result = NULL;

	  else

	    {

	      /* Get the desired function.  */

	      size_t namlen = (5 + strlen (ni->name) + 1

			       + strlen (fct_name) + 1);

	      char name[namlen];

	      /* Construct the function name.  */

	      __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),

					    ni->name),

				  "_"),

			fct_name);

	      /* Look up the symbol.  */

	      result = __libc_dlsym (ni->library->lib_handle, name);

	    }

#else

	  /* We can't get function address dynamically in static linking. */

	  {

# define DEFINE_ENT(h,nm)						      \

	    { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },		      \

	    { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },		      \

	    { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },

# define DEFINE_GET(h,nm)						      \

	    { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },

# define DEFINE_GETBY(h,nm,ky)						      \

	    { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },

	    static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =

	      {

# include "function.def"

		{ NULL, NULL }

	      };

	    size_t namlen = (5 + strlen (ni->name) + 1

			     + strlen (fct_name) + 1);

	    char name[namlen];

	    /* Construct the function name.  */

	    __stpcpy (__stpcpy (__stpcpy (name, ni->name),

				"_"),

		      fct_name);

	    result = NULL;

	    for (tp = &tbl[0]; tp->fname; tp++)

	      if (strcmp (tp->fname, name) == 0)

		{

		  result = tp->fp;

		  break;

		}

	  }

#endif

	  /* Remember function pointer for later calls.  Even if null, we

	     record it so a second try needn't search the library again.  */

	  known->fct_ptr = result;

#ifdef PTR_MANGLE

	  PTR_MANGLE (known->fct_ptr);

#endif

	}

    }

  /* Remove the lock.  */

  __libc_lock_unlock (lock);

  return result;

}

libc_hidden_def (__nss_lookup_function)

static name_database *

nss_parse_file (const char *fname)

{

  FILE *fp;

  name_database *result;

  name_database_entry *last;

  char *line;

  size_t len;

  /* Open the configuration file.  */

  fp = fopen (fname, "rce");

  if (fp == NULL)

    return NULL;

  /* No threads use this stream.  */

  __fsetlocking (fp, FSETLOCKING_BYCALLER);

  result = (name_database *) malloc (sizeof (name_database));

  if (result == NULL)

    {

      fclose (fp);

      return NULL;

    }

  result->entry = NULL;

  result->library = NULL;

  last = NULL;

  line = NULL;

  len = 0;

  do

    {

      name_database_entry *this;

      ssize_t n;

      n = __getline (&line, &len, fp);

      if (n < 0)

	break;

      if (line[n - 1] == '\n')

	line[n - 1] = '\0';

      /* Because the file format does not know any form of quoting we

	 can search forward for the next '#' character and if found

	 make it terminating the line.  */

      *__strchrnul (line, '#') = '\0';

      /* If the line is blank it is ignored.  */

      if (line[0] == '\0')

	continue;

      /* Each line completely specifies the actions for a database.  */

      this = nss_getline (line);

      if (this != NULL)

	{

	  if (last != NULL)

	    last->next = this;

	  else

	    result->entry = this;

	  last = this;

	}

    }

  while (!__feof_unlocked (fp));

  /* Free the buffer.  */

  free (line);

  /* Close configuration file.  */

  fclose (fp);

  return result;

}

/* Read the source names:

	`( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'

   */

static service_user *

nss_parse_service_list (const char *line)

{

  service_user *result = NULL, **nextp = &result;

  while (1)

    {

      service_user *new_service;

      const char *name;

      while (isspace (line[0]))

	++line;

      if (line[0] == '\0')

	/* No source specified.  */

	return result;

      /* Read <source> identifier.  */

      name = line;

      while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')

	++line;

      if (name == line)

	return result;

      new_service = (service_user *) malloc (sizeof (service_user)

					     + (line - name + 1));

      if (new_service == NULL)

	return result;

      *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';

      /* Set default actions.  */

      new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;

      new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;

      new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;

      new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;

      new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;

      new_service->library = NULL;

      new_service->known = NULL;

      new_service->next = NULL;

      while (isspace (line[0]))

	++line;

      if (line[0] == '[')

	{

	  /* Read criterions.  */

	  do

	    ++line;

	  while (line[0] != '\0' && isspace (line[0]));

	  do

	    {

	      int not;

	      enum nss_status status;

	      lookup_actions action;

	      /* Grok ! before name to mean all statii but that one.  */

	      not = line[0] == '!';

	      if (not)

		++line;

	      /* Read status name.  */

	      name = line;

	      while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='

		     && line[0] != ']')

		++line;

	      /* Compare with known statii.  */

	      if (line - name == 7)

		{

		  if (__strncasecmp (name, "SUCCESS", 7) == 0)

		    status = NSS_STATUS_SUCCESS;

		  else if (__strncasecmp (name, "UNAVAIL", 7) == 0)

		    status = NSS_STATUS_UNAVAIL;

		  else

		    goto finish;

		}

	      else if (line - name == 8)

		{

		  if (__strncasecmp (name, "NOTFOUND", 8) == 0)

		    status = NSS_STATUS_NOTFOUND;

		  else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)

		    status = NSS_STATUS_TRYAGAIN;

		  else

		    goto finish;

		}

	      else

		goto finish;

	      while (isspace (line[0]))

		++line;

	      if (line[0] != '=')

		goto finish;

	      do

		++line;

	      while (isspace (line[0]));

	      name = line;

	      while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='

		     && line[0] != ']')

		++line;

	      if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)

		action = NSS_ACTION_RETURN;

	      else if (line - name == 8

		       && __strncasecmp (name, "CONTINUE", 8) == 0)

		action = NSS_ACTION_CONTINUE;

	      else if (line - name == 5

		       && __strncasecmp (name, "MERGE", 5) == 0)

		action = NSS_ACTION_MERGE;

	      else

		goto finish;

	      if (not)

		{

		  /* Save the current action setting for this status,

		     set them all to the given action, and reset this one.  */

		  const lookup_actions save = new_service->actions[2 + status];

		  new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;

		  new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;

		  new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;

		  new_service->actions[2 + NSS_STATUS_SUCCESS] = action;

		  new_service->actions[2 + status] = save;

		}

	      else

		new_service->actions[2 + status] = action;

	      /* Skip white spaces.  */

	      while (isspace (line[0]))

		++line;

	    }

	  while (line[0] != ']');

	  /* Skip the ']'.  */

	  ++line;

	}

      *nextp = new_service;

      nextp = &new_service->next;

      continue;

    finish:

      free (new_service);

      return result;

    }

}

static name_database_entry *

nss_getline (char *line)

{

  const char *name;

  name_database_entry *result;

  size_t len;

  /* Ignore leading white spaces.  ATTENTION: this is different from

     what is implemented in Solaris.  The Solaris man page says a line

     beginning with a white space character is ignored.  We regard

     this as just another misfeature in Solaris.  */

  while (isspace (line[0]))

    ++line;

  /* Recognize `<database> ":"'.  */

  name = line;

  while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')

    ++line;

  if (line[0] == '\0' || name == line)

    /* Syntax error.  */

    return NULL;

  *line++ = '\0';

  len = strlen (name) + 1;

  result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);

  if (result == NULL)

    return NULL;

  /* Save the database name.  */

  memcpy (result->name, name, len);

  /* Parse the list of services.  */

  result->service = nss_parse_service_list (line);

  result->next = NULL;

  return result;

}

#if !defined DO_STATIC_NSS || defined SHARED

static service_library *

nss_new_service (name_database *database, const char *name)

{

  service_library **currentp = &database->library;

  while (*currentp != NULL)

    {

      if (strcmp ((*currentp)->name, name) == 0)

	return *currentp;

      currentp = &(*currentp)->next;

    }

  /* We have to add the new service.  */

  *currentp = (service_library *) malloc (sizeof (service_library));

  if (*currentp == NULL)

    return NULL;

  (*currentp)->name = name;

  (*currentp)->lib_handle = NULL;

  (*currentp)->next = NULL;

  return *currentp;

}

#endif

#if defined SHARED && defined USE_NSCD

/* Load all libraries for the service.  */

static void

nss_load_all_libraries (const char *service, const char *def)

{

  service_user *ni = NULL;

  if (__nss_database_lookup2 (service, NULL, def, &ni) == 0)

    while (ni != NULL)

      {

	nss_load_library (ni);

	ni = ni->next;

      }

}

/* Called by nscd and nscd alone.  */

void

__nss_disable_nscd (void (*cb) (size_t, struct traced_file *))

{

# ifdef PTR_MANGLE

  PTR_MANGLE (cb);

# endif

  nscd_init_cb = cb;

  is_nscd = true;

  /* Find all the relevant modules so that the init functions are called.  */

  nss_load_all_libraries ("passwd", DEFAULT_CONFIG);

  nss_load_all_libraries ("group", DEFAULT_CONFIG);

  nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");

  nss_load_all_libraries ("services", NULL);

  /* Disable all uses of NSCD.  */

  __nss_not_use_nscd_passwd = -1;

  __nss_not_use_nscd_group = -1;

  __nss_not_use_nscd_hosts = -1;

  __nss_not_use_nscd_services = -1;

  __nss_not_use_nscd_netgroup = -1;

}

#endif

static void

free_database_entries (name_database_entry *entry)

{

  while (entry != NULL)

    {

      name_database_entry *olde = entry;

      service_user *service = entry->service;

      while (service != NULL)

	{

	  service_user *olds = service;

	  if (service->known != NULL)

	    __tdestroy (service->known, free);

	  service = service->next;

	  free (olds);

	}