Update.

[glibc.git] / nis / nss_compat / compat-pwd.c

/* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 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 <nss.h>
#include <pwd.h>
#include <errno.h>
#include <ctype.h>
#include <fcntl.h>
#include <netdb.h>
#include <string.h>
#include <bits/libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include <rpcsvc/nis.h>
#include <nsswitch.h>

/* Comment out the following line for the production version.  */
/* #define NDEBUG 1 */
#include <assert.h>

#include "netgroup.h"
#include "nss-nisplus.h"
#include "nisplus-parser.h"

static service_user *ni = NULL;
static bool_t use_nisplus = FALSE; /* default: passwd_compat: nis */
static nis_name pwdtable = NULL; /* Name of the pwd table */
static size_t pwdtablelen = 0;

/* Get the declaration of the parser function.  */
#define ENTNAME pwent
#define STRUCTURE passwd
#define EXTERN_PARSER
#include <nss/nss_files/files-parse.c>

/* Structure for remembering -@netgroup and -user members ... */
#define BLACKLIST_INITIAL_SIZE 512
#define BLACKLIST_INCREMENT 256
struct blacklist_t
  {
    char *data;
    int current;
    int size;
  };

struct ent_t
  {
    bool_t netgroup;
    bool_t nis;
    bool_t first;
    char *oldkey;
    int oldkeylen;
    nis_result *result;
    FILE *stream;
    struct blacklist_t blacklist;
    struct passwd pwd;
    struct __netgrent netgrdata;
  };
typedef struct ent_t ent_t;

static ent_t ext_ent = {0, 0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0},
                        {NULL, NULL, 0, 0, NULL, NULL, NULL}};

/* Protect global state against multiple changers.  */
__libc_lock_define_initialized (static, lock)

/* Prototypes for local functions.  */
static void blacklist_store_name (const char *, ent_t *);
static int in_blacklist (const char *, int, ent_t *);

static void
give_pwd_free (struct passwd *pwd)
{
  if (pwd->pw_name != NULL)
    free (pwd->pw_name);
  if (pwd->pw_passwd != NULL)
    free (pwd->pw_passwd);
  if (pwd->pw_gecos != NULL)
    free (pwd->pw_gecos);
  if (pwd->pw_dir != NULL)
    free (pwd->pw_dir);
  if (pwd->pw_shell != NULL)
    free (pwd->pw_shell);

  memset (pwd, '\0', sizeof (struct passwd));
}

static size_t
pwd_need_buflen (struct passwd *pwd)
{
  size_t len = 0;

  if (pwd->pw_passwd != NULL)
    len += strlen (pwd->pw_passwd) + 1;

  if (pwd->pw_gecos != NULL)
    len += strlen (pwd->pw_gecos) + 1;

  if (pwd->pw_dir != NULL)
    len += strlen (pwd->pw_dir) + 1;

  if (pwd->pw_shell != NULL)
    len += strlen (pwd->pw_shell) + 1;

  return len;
}

static void
copy_pwd_changes (struct passwd *dest, struct passwd *src,
                  char *buffer, size_t buflen)
{
  if (src->pw_passwd != NULL && strlen (src->pw_passwd))
    {
      if (buffer == NULL)
        dest->pw_passwd = strdup (src->pw_passwd);
      else if (dest->pw_passwd &&
               strlen (dest->pw_passwd) >= strlen (src->pw_passwd))
        strcpy (dest->pw_passwd, src->pw_passwd);
      else
        {
          dest->pw_passwd = buffer;
          strcpy (dest->pw_passwd, src->pw_passwd);
          buffer += strlen (dest->pw_passwd) + 1;
          buflen = buflen - (strlen (dest->pw_passwd) + 1);
        }
    }

  if (src->pw_gecos != NULL && strlen (src->pw_gecos))
    {
      if (buffer == NULL)
        dest->pw_gecos = strdup (src->pw_gecos);
      else if (dest->pw_gecos &&
               strlen (dest->pw_gecos) >= strlen (src->pw_gecos))
        strcpy (dest->pw_gecos, src->pw_gecos);
      else
        {
          dest->pw_gecos = buffer;
          strcpy (dest->pw_gecos, src->pw_gecos);
          buffer += strlen (dest->pw_gecos) + 1;
          buflen = buflen - (strlen (dest->pw_gecos) + 1);
        }
    }
  if (src->pw_dir != NULL && strlen (src->pw_dir))
    {
      if (buffer == NULL)
        dest->pw_dir = strdup (src->pw_dir);
      else if (dest->pw_dir &&
               strlen (dest->pw_dir) >= strlen (src->pw_dir))
        strcpy (dest->pw_dir, src->pw_dir);
      else
        {
          dest->pw_dir = buffer;
          strcpy (dest->pw_dir, src->pw_dir);
          buffer += strlen (dest->pw_dir) + 1;
          buflen = buflen - (strlen (dest->pw_dir) + 1);
        }
    }

  if (src->pw_shell != NULL && strlen (src->pw_shell))
    {
      if (buffer == NULL)
        dest->pw_shell = strdup (src->pw_shell);
      else if (dest->pw_shell &&
               strlen (dest->pw_shell) >= strlen (src->pw_shell))
        strcpy (dest->pw_shell, src->pw_shell);
      else
        {
          dest->pw_shell = buffer;
          strcpy (dest->pw_shell, src->pw_shell);
          buffer += strlen (dest->pw_shell) + 1;
          buflen = buflen - (strlen (dest->pw_shell) + 1);
        }
    }
}

static enum nss_status
internal_setpwent (ent_t *ent)
{
  enum nss_status status = NSS_STATUS_SUCCESS;

  ent->nis = ent->first = ent->netgroup = 0;

  /* If something was left over free it.  */
  if (ent->netgroup)
    __internal_endnetgrent (&ent->netgrdata);

  if (ent->oldkey != NULL)
    {
      free (ent->oldkey);
      ent->oldkey = NULL;
      ent->oldkeylen = 0;
    }

  if (ent->result != NULL)
    {
      nis_freeresult (ent->result);
      ent->result = NULL;
    }

  if (pwdtable == NULL)
    {
      static const char key[] = "passwd.org_dir.";
      const char *local_dir = nis_local_directory ();
      size_t len_local_dir = strlen (local_dir);

      pwdtable = malloc (sizeof (key) + len_local_dir);
      if (pwdtable == NULL)
        return NSS_STATUS_TRYAGAIN;

      pwdtablelen = ((char *) mempcpy (mempcpy (pwdtable,
                                                key, sizeof (key) - 1),
                                       local_dir, len_local_dir + 1)
                     - pwdtable) - 1;

      /* *Maybe* (I'm no NIS expert) we have to duplicate the `local_dir'
         value since it might change during our work.  So add a test here.  */
      assert (pwdtablelen == sizeof (key) + len_local_dir);
    }

  ent->blacklist.current = 0;
  if (ent->blacklist.data != NULL)
    ent->blacklist.data[0] = '\0';

  if (ent->stream == NULL)
    {
      ent->stream = fopen ("/etc/passwd", "r");

      if (ent->stream == NULL)
        status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
      else
        {
          /* We have to make sure the file is  `closed on exec'.  */
          int result, flags;

          result = flags = fcntl (fileno (ent->stream), F_GETFD, 0);
          if (result >= 0)
            {
              flags |= FD_CLOEXEC;
              result = fcntl (fileno (ent->stream), F_SETFD, flags);
            }
          if (result < 0)
            {
              /* Something went wrong.  Close the stream and return a
                 failure.  */
              fclose (ent->stream);
              ent->stream = NULL;
              status = NSS_STATUS_UNAVAIL;
            }
        }
    }
  else
    rewind (ent->stream);

  give_pwd_free (&ent->pwd);

  return status;
}


enum nss_status
_nss_compat_setpwent (void)
{
  enum nss_status result;

  __libc_lock_lock (lock);

  if (ni == NULL)
    {
      __nss_database_lookup ("passwd_compat", NULL, "nis", &ni);
      use_nisplus = (strcmp (ni->name, "nisplus") == 0);
    }

  result = internal_setpwent (&ext_ent);

  __libc_lock_unlock (lock);

  return result;
}


static enum nss_status
internal_endpwent (ent_t *ent)
{
  if (ent->stream != NULL)
    {
      fclose (ent->stream);
      ent->stream = NULL;
    }

  if (ent->netgroup)
    __internal_endnetgrent (&ent->netgrdata);

  ent->nis = ent->first = ent->netgroup = 0;

  if (ent->oldkey != NULL)
    {
      free (ent->oldkey);
      ent->oldkey = NULL;
      ent->oldkeylen = 0;
    }

  if (ent->result != NULL)
    {
      nis_freeresult (ent->result);
      ent->result = NULL;
    }

  ent->blacklist.current = 0;
  if (ent->blacklist.data != NULL)
    ent->blacklist.data[0] = '\0';

  give_pwd_free (&ent->pwd);

  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_compat_endpwent (void)
{
  enum nss_status result;

  __libc_lock_lock (lock);

  result = internal_endpwent (&ext_ent);

  __libc_lock_unlock (lock);

  return result;
}

static enum nss_status
getpwent_next_nis_netgr (const char *name, struct passwd *result, ent_t *ent,
                         char *group, char *buffer, size_t buflen)
{
  struct parser_data *data = (void *) buffer;
  char *ypdomain, *host, *user, *domain, *outval, *p, *p2;
  int status, outvallen;
  size_t p2len;

  if (yp_get_default_domain (&ypdomain) != YPERR_SUCCESS)
    {
      ent->netgroup = 0;
      ent->first = 0;
      give_pwd_free (&ent->pwd);
      return NSS_STATUS_UNAVAIL;
    }

  if (ent->first == TRUE)
    {
      memset (&ent->netgrdata, 0, sizeof (struct __netgrent));
      __internal_setnetgrent (group, &ent->netgrdata);
      ent->first = FALSE;
    }

  while (1)
    {
      char *saved_cursor;
      int parse_res;

      saved_cursor = ent->netgrdata.cursor;
      status = __internal_getnetgrent_r (&host, &user, &domain,
                                         &ent->netgrdata, buffer, buflen);
      if (status != 1)
        {
          __internal_endnetgrent (&ent->netgrdata);
          ent->netgroup = 0;
          give_pwd_free (&ent->pwd);
          return NSS_STATUS_RETURN;
        }

      if (user == NULL || user[0] == '-')
        continue;

      if (domain != NULL && strcmp (ypdomain, domain) != 0)
        continue;

      /* If name != NULL, we are called from getpwnam */
      if (name != NULL)
        if (strcmp (user, name) != 0)
          continue;

      if (yp_match (ypdomain, "passwd.byname", user,
                    strlen (user), &outval, &outvallen)
          != YPERR_SUCCESS)
        continue;

      p2len = pwd_need_buflen (&ent->pwd);
      if (p2len > buflen)
        {
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      p2 = buffer + (buflen - p2len);
      buflen -= p2len;
      p = strncpy (buffer, outval, buflen);
      while (isspace (*p))
        p++;
      free (outval);
      if ((parse_res = _nss_files_parse_pwent (p, result, data, buflen)) == -1)
        {
          ent->netgrdata.cursor = saved_cursor;
          return NSS_STATUS_TRYAGAIN;
        }

      if (parse_res)
        {
          /* Store the User in the blacklist for the "+" at the end of
             /etc/passwd */
          blacklist_store_name (result->pw_name, ent);
          copy_pwd_changes (result, &ent->pwd, p2, p2len);
          break;
        }
    }

  return NSS_STATUS_SUCCESS;
}

static enum nss_status
getpwent_next_nisplus_netgr (const char *name, struct passwd *result,
                             ent_t *ent, char *group, char *buffer,
                             size_t buflen)
{
  char *ypdomain, *host, *user, *domain, *p2;
  int status, parse_res;
  size_t p2len;
  nis_result *nisres;

  /* Maybe we should use domainname here ? We need the current
     domainname for the domain field in netgroups */
  if (yp_get_default_domain (&ypdomain) != YPERR_SUCCESS)
    {
      ent->netgroup = 0;
      ent->first = 0;
      give_pwd_free (&ent->pwd);
      return NSS_STATUS_UNAVAIL;
    }

  if (ent->first == TRUE)
    {
      bzero (&ent->netgrdata, sizeof (struct __netgrent));
      __internal_setnetgrent (group, &ent->netgrdata);
      ent->first = FALSE;
    }

  while (1)
    {
      char *saved_cursor;

      saved_cursor = ent->netgrdata.cursor;
      status = __internal_getnetgrent_r (&host, &user, &domain,
                                         &ent->netgrdata, buffer, buflen);
      if (status != 1)
        {
          __internal_endnetgrent (&ent->netgrdata);
          ent->netgroup = 0;
          give_pwd_free (&ent->pwd);
          return NSS_STATUS_RETURN;
        }

      if (user == NULL || user[0] == '-')
        continue;

      if (domain != NULL && strcmp (ypdomain, domain) != 0)
        continue;

      /* If name != NULL, we are called from getpwnam */
      if (name != NULL)
        if (strcmp (user, name) != 0)
          continue;

      p2len = pwd_need_buflen (&ent->pwd);
      if (p2len > buflen)
        {
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      p2 = buffer + (buflen - p2len);
      buflen -= p2len;
      {
        char buf[strlen (user) + 30 + pwdtablelen];
        sprintf(buf, "[name=%s],%s", user, pwdtable);
        nisres = nis_list(buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
      }
      if (niserr2nss (nisres->status) != NSS_STATUS_SUCCESS)
        {
          nis_freeresult (nisres);
          continue;
        }
      if ((parse_res = _nss_nisplus_parse_pwent (nisres, result, buffer,
                                                 buflen)) == -1)
        {
          nis_freeresult (nisres);
          ent->netgrdata.cursor = saved_cursor;
          return NSS_STATUS_TRYAGAIN;
        }
      nis_freeresult (nisres);

      if (parse_res)
        {
          /* Store the User in the blacklist for the "+" at the end of
             /etc/passwd */
          blacklist_store_name (result->pw_name, ent);
          copy_pwd_changes (result, &ent->pwd, p2, p2len);
          break;
        }
    }

  return NSS_STATUS_SUCCESS;
}

static enum nss_status
getpwent_next_nisplus (struct passwd *result, ent_t *ent, char *buffer,
                       size_t buflen)
{
  int parse_res;
  size_t p2len;
  char *p2;

  p2len = pwd_need_buflen (&ent->pwd);
  if (p2len > buflen)
    {
      __set_errno (ERANGE);
      return NSS_STATUS_TRYAGAIN;
    }
  p2 = buffer + (buflen - p2len);
  buflen -= p2len;
  do
    {
      bool_t saved_first;
      nis_result *saved_res;

      if (ent->first)
        {
          saved_first = TRUE;
          saved_res = ent->result;

          ent->result = nis_first_entry(pwdtable);
          if (niserr2nss (ent->result->status) != NSS_STATUS_SUCCESS)
            {
              ent->nis = 0;
              give_pwd_free (&ent->pwd);
              return niserr2nss (ent->result->status);
            }
          ent->first = FALSE;
        }
      else
        {
          nis_result *res;

          res = nis_next_entry(pwdtable, &ent->result->cookie);
          saved_res = ent->result;
          saved_first = FALSE;
          ent->result = res;
          if (niserr2nss (ent->result->status) != NSS_STATUS_SUCCESS)
            {
              ent->nis = 0;
              nis_freeresult (saved_res);
              give_pwd_free (&ent->pwd);
              return niserr2nss (ent->result->status);
            }
        }
      if ((parse_res = _nss_nisplus_parse_pwent (ent->result, result, buffer,
                                                 buflen)) == -1)
        {
          nis_freeresult (ent->result);
          ent->result = saved_res;
          ent->first = saved_first;
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      else
        {
          if (!saved_first)
            nis_freeresult (saved_res);
        }

      if (parse_res &&
          in_blacklist (result->pw_name, strlen (result->pw_name), ent))
        parse_res = 0; /* if result->pw_name in blacklist,search next entry */
    }
  while (!parse_res);

  copy_pwd_changes (result, &ent->pwd, p2, p2len);

  return NSS_STATUS_SUCCESS;
}

static enum nss_status
getpwent_next_nis (struct passwd *result, ent_t *ent, char *buffer,
                   size_t buflen)
{
  struct parser_data *data = (void *) buffer;
  char *domain, *outkey, *outval, *p, *p2;
  int outkeylen, outvallen, parse_res;
  size_t p2len;

  if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
    {
      ent->nis = 0;
      give_pwd_free (&ent->pwd);
      return NSS_STATUS_UNAVAIL;
    }

  p2len = pwd_need_buflen (&ent->pwd);
  if (p2len > buflen)
    {
      __set_errno (ERANGE);
      return NSS_STATUS_TRYAGAIN;
    }
  p2 = buffer + (buflen - p2len);
  buflen -= p2len;
  do
    {
      bool_t saved_first;
      char *saved_oldkey;
      int saved_oldlen;

      if (ent->first)
        {
          if (yp_first (domain, "passwd.byname", &outkey, &outkeylen,
                        &outval, &outvallen) != YPERR_SUCCESS)
            {
              ent->nis = 0;
              give_pwd_free (&ent->pwd);
              return NSS_STATUS_UNAVAIL;
            }

          saved_first = TRUE;
          saved_oldkey = ent->oldkey;
          saved_oldlen = ent->oldkeylen;
          ent->oldkey = outkey;
          ent->oldkeylen = outkeylen;
          ent->first = FALSE;
        }
      else
        {
          if (yp_next (domain, "passwd.byname", ent->oldkey, ent->oldkeylen,
                       &outkey, &outkeylen, &outval, &outvallen)
              != YPERR_SUCCESS)
            {
              ent->nis = 0;
              give_pwd_free (&ent->pwd);
              return NSS_STATUS_NOTFOUND;
            }

          saved_first = FALSE;
          saved_oldkey = ent->oldkey;
          saved_oldlen = ent->oldkeylen;
          ent->oldkey = outkey;
          ent->oldkeylen = outkeylen;
        }

      /* Copy the found data to our buffer  */
      p = strncpy (buffer, outval, buflen);

      /* ...and free the data.  */
      free (outval);

      while (isspace (*p))
        ++p;
      if ((parse_res = _nss_files_parse_pwent (p, result, data, buflen)) == -1)
        {
          free (ent->oldkey);
          ent->oldkey = saved_oldkey;
          ent->oldkeylen = saved_oldlen;
          ent->first = saved_first;
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      else
        {
          if (!saved_first)
            free (saved_oldkey);
        }
      if (parse_res &&
          in_blacklist (result->pw_name, strlen (result->pw_name), ent))
        parse_res = 0;
    }
  while (!parse_res);

  copy_pwd_changes (result, &ent->pwd, p2, p2len);

  return NSS_STATUS_SUCCESS;
}

/* This function handle the +user entrys in /etc/passwd */
static enum nss_status
getpwnam_plususer (const char *name, struct passwd *result, char *buffer,
                   size_t buflen)
{
  struct parser_data *data = (void *) buffer;
  struct passwd pwd;
  int parse_res;
  char *p;
  size_t plen;

  memset (&pwd, '\0', sizeof (struct passwd));

  copy_pwd_changes (&pwd, result, NULL, 0);

  plen = pwd_need_buflen (&pwd);
  if (plen > buflen)
    {
      __set_errno (ERANGE);
      return NSS_STATUS_TRYAGAIN;
    }
  p = buffer + (buflen - plen);
  buflen -= plen;

  if (use_nisplus) /* Do the NIS+ query here */
    {
      nis_result *res;
      char buf[strlen (name) + 24 + pwdtablelen];

      sprintf(buf, "[name=%s],%s", name, pwdtable);
      res = nis_list(buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
      if (niserr2nss (res->status) != NSS_STATUS_SUCCESS)
        {
          enum nss_status status =  niserr2nss (res->status);

          nis_freeresult (res);
          return status;
        }
      if ((parse_res = _nss_nisplus_parse_pwent (res, result, buffer,
                                                 buflen)) == -1)
        {
          nis_freeresult (res);
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      nis_freeresult (res);
    }
  else /* Use NIS */
    {
      char *domain, *outval, *ptr;
      int outvallen;

      if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
        return NSS_STATUS_TRYAGAIN;

      if (yp_match (domain, "passwd.byname", name, strlen (name),
                    &outval, &outvallen)
          != YPERR_SUCCESS)
        return NSS_STATUS_TRYAGAIN;
      ptr = strncpy (buffer, outval, buflen < (size_t) outvallen ?
                     buflen : (size_t) outvallen);
      buffer[buflen < (size_t) outvallen ? buflen : (size_t) outvallen] = '\0';
      free (outval);
      while (isspace (*ptr))
        ptr++;
      if ((parse_res = _nss_files_parse_pwent (ptr, result, data, buflen))
          == -1)
        {
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
    }

  if (parse_res > 0)
    {
      copy_pwd_changes (result, &pwd, p, plen);
      give_pwd_free (&pwd);
      /* We found the entry.  */
      return NSS_STATUS_SUCCESS;
    }
  else
    {
      /* Give buffer the old len back */
      buflen += plen;
      give_pwd_free (&pwd);
    }
  return NSS_STATUS_RETURN;
}

static enum nss_status
getpwent_next_file (struct passwd *result, ent_t *ent,
                    char *buffer, size_t buflen)
{
  struct parser_data *data = (void *) buffer;
  while (1)
    {
      fpos_t pos;
      char *p;
      int parse_res;

      do
        {
          fgetpos (ent->stream, &pos);
          p = fgets (buffer, buflen, ent->stream);
          if (p == NULL)
            return NSS_STATUS_NOTFOUND;

          /* Terminate the line for any case.  */
          buffer[buflen - 1] = '\0';

          /* Skip leading blanks.  */
          while (isspace (*p))
            ++p;
        }
      while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines.  */
      /* Parse the line.  If it is invalid, loop to
         get the next line of the file to parse.  */
             !(parse_res = _nss_files_parse_pwent (p, result, data, buflen)));

      if (parse_res == -1)
        {
          /* The parser ran out of space.  */
          fsetpos (ent->stream, &pos);
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }

      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
        /* This is a real entry.  */
        break;

      /* -@netgroup */
      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          char buf2[1024];
          char *user, *host, *domain;
          struct __netgrent netgrdata;

          bzero (&netgrdata, sizeof (struct __netgrent));
          __internal_setnetgrent (&result->pw_name[2], &netgrdata);
          while (__internal_getnetgrent_r (&host, &user, &domain,
                                           &netgrdata, buf2, sizeof (buf2)))
            {
              if (user != NULL && user[0] != '-')
                blacklist_store_name (user, ent);
            }
          __internal_endnetgrent (&netgrdata);
          continue;
        }

      /* +@netgroup */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          int status;

          ent->netgroup = TRUE;
          ent->first = TRUE;
          copy_pwd_changes (&ent->pwd, result, NULL, 0);

          if (use_nisplus)
            status =  getpwent_next_nisplus_netgr (NULL, result, ent,
                                                   &result->pw_name[2],
                                                   buffer, buflen);
          else
            status =  getpwent_next_nis_netgr (NULL, result, ent,
                                               &result->pw_name[2],
                                               buffer, buflen);
          if (status == NSS_STATUS_RETURN)
            continue;
          else
            return status;
        }

      /* -user */
      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          blacklist_store_name (&result->pw_name[1], ent);
          continue;
        }

      /* +user */
      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          enum nss_status status;

          /* Store the User in the blacklist for the "+" at the end of
             /etc/passwd */
          blacklist_store_name (&result->pw_name[1], ent);
          status = getpwnam_plususer (&result->pw_name[1], result, buffer,
                                      buflen);
          if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
            break;
          else
            if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
              continue;
            else
              return status;
        }

      /* +:... */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
        {
          ent->nis = TRUE;
          ent->first = TRUE;
          copy_pwd_changes (&ent->pwd, result, NULL, 0);

          if (use_nisplus)
            return getpwent_next_nisplus (result, ent, buffer, buflen);
          else
            return getpwent_next_nis (result, ent, buffer, buflen);
        }
    }

  return NSS_STATUS_SUCCESS;
}


static enum nss_status
internal_getpwent_r (struct passwd *pw, ent_t *ent, char *buffer,
                     size_t buflen)
{
  if (ent->netgroup)
    {
      int status;

      /* We are searching members in a netgroup */
      /* Since this is not the first call, we don't need the group name */
      if (use_nisplus)
        status = getpwent_next_nisplus_netgr (NULL, pw, ent, NULL, buffer,
                                              buflen);
      else
        status = getpwent_next_nis_netgr (NULL, pw, ent, NULL, buffer, buflen);
      if (status == NSS_STATUS_RETURN)
        return getpwent_next_file (pw, ent, buffer, buflen);
      else
        return status;
    }
  else
    if (ent->nis)
      {
        if (use_nisplus)
          return getpwent_next_nisplus (pw, ent, buffer, buflen);
        else
          return getpwent_next_nis (pw, ent, buffer, buflen);
      }
    else
      return getpwent_next_file (pw, ent, buffer, buflen);
}

enum nss_status
_nss_compat_getpwent_r (struct passwd *pwd, char *buffer, size_t buflen)
{
  enum nss_status status = NSS_STATUS_SUCCESS;

  __libc_lock_lock (lock);

  if (ni == NULL)
    {
      __nss_database_lookup ("passwd_compat", NULL, "nis", &ni);
      use_nisplus = (strcmp (ni->name, "nisplus") == 0);
    }

  /* Be prepared that the setpwent function was not called before.  */
  if (ext_ent.stream == NULL)
    status = internal_setpwent (&ext_ent);

  if (status == NSS_STATUS_SUCCESS)
    status = internal_getpwent_r (pwd, &ext_ent, buffer, buflen);

  __libc_lock_unlock (lock);

  return status;
}

/* Searches in /etc/passwd and the NIS/NIS+ map for a special user */
static enum nss_status
internal_getpwnam_r (const char *name, struct passwd *result, ent_t *ent,
                     char *buffer, size_t buflen)
{
  struct parser_data *data = (void *) buffer;

  while (1)
    {
      fpos_t pos;
      char *p;
      int parse_res;

      do
        {
          fgetpos (ent->stream, &pos);
          p = fgets (buffer, buflen, ent->stream);
          if (p == NULL)
            {
              if (feof (ent->stream))
                return NSS_STATUS_NOTFOUND;
              else
                {
                  __set_errno (ERANGE);
                  return NSS_STATUS_TRYAGAIN;
                }
            }

          /* Terminate the line for any case.  */
          buffer[buflen - 1] = '\0';

          /* Skip leading blanks.  */
          while (isspace (*p))
            ++p;
        }
      while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines.  */
             /* Parse the line.  If it is invalid, loop to
                get the next line of the file to parse.  */
             !(parse_res = _nss_files_parse_pwent (p, result, data, buflen)));

      if (parse_res == -1)
        {
          /* The parser ran out of space.  */
          fsetpos (ent->stream, &pos);
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }

      /* This is a real entry.  */
      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
        {
          if (strcmp (result->pw_name, name) == 0)
            return NSS_STATUS_SUCCESS;
          else
            continue;
        }

      /* -@netgroup */
      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          char buf2[1024];
          char *user, *host, *domain;
          struct __netgrent netgrdata;

          bzero (&netgrdata, sizeof (struct __netgrent));
          __internal_setnetgrent (&result->pw_name[2], &netgrdata);
          while (__internal_getnetgrent_r (&host, &user, &domain,
                                           &netgrdata, buf2, sizeof (buf2)))
            {
              if (user != NULL && user[0] != '-')
                if (strcmp (user, name) == 0)
                  return NSS_STATUS_NOTFOUND;
            }
          __internal_endnetgrent (&netgrdata);
          continue;
        }

      /* +@netgroup */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          char buf[strlen (result->pw_name)];
          int status;

          strcpy (buf, &result->pw_name[2]);
          ent->netgroup = TRUE;
          ent->first = TRUE;
          copy_pwd_changes (&ent->pwd, result, NULL, 0);

          do
            {
              if (use_nisplus)
                status = getpwent_next_nisplus_netgr (name, result, ent, buf,
                                                      buffer, buflen);
              else
                status = getpwent_next_nis_netgr (name, result, ent, buf,
                                                  buffer, buflen);
              if (status == NSS_STATUS_RETURN)
                continue;

              if (status == NSS_STATUS_SUCCESS &&
                  strcmp (result->pw_name, name) == 0)
                return NSS_STATUS_SUCCESS;
            } while (status == NSS_STATUS_SUCCESS);
          continue;
        }

      /* -user */
      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          if (strcmp (&result->pw_name[1], name) == 0)
            return NSS_STATUS_NOTFOUND;
          else
            continue;
        }

      /* +user */
      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          if (strcmp (name, &result->pw_name[1]) == 0)
            {
              enum nss_status status;

              status = getpwnam_plususer (name, result, buffer, buflen);
              if (status == NSS_STATUS_RETURN)
                /* We couldn't parse the entry */
                return NSS_STATUS_NOTFOUND;
              else
                return status;
            }
        }

      /* +:... */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
        {
          enum nss_status status;

          status = getpwnam_plususer (name, result, buffer, buflen);
          if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
            break;
          else
            if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
              return NSS_STATUS_NOTFOUND;
            else
              return status;
        }
    }
  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_compat_getpwnam_r (const char *name, struct passwd *pwd,
                        char *buffer, size_t buflen)
{
  ent_t ent = {0, 0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0},
               {NULL, NULL, 0, 0, NULL, NULL, NULL}};
  enum nss_status status;

  if (name[0] == '-' || name[0] == '+')
    return NSS_STATUS_NOTFOUND;

  __libc_lock_lock (lock);

  if (ni == NULL)
    {
      __nss_database_lookup ("passwd_compat", NULL, "nis", &ni);
      use_nisplus = (strcmp (ni->name, "nisplus") == 0);
    }

  __libc_lock_unlock (lock);

  status = internal_setpwent (&ent);
  if (status != NSS_STATUS_SUCCESS)
    return status;

  status = internal_getpwnam_r (name, pwd, &ent, buffer, buflen);

  internal_endpwent (&ent);

  return status;
}

/* This function handle the + entry in /etc/passwd for getpwuid */
static enum nss_status
getpwuid_plususer (uid_t uid, struct passwd *result, char *buffer,
                   size_t buflen)
{
  struct parser_data *data = (void *) buffer;
  struct passwd pwd;
  int parse_res;
  char *p;
  size_t plen;

  memset (&pwd, '\0', sizeof (struct passwd));

  copy_pwd_changes (&pwd, result, NULL, 0);

  plen = pwd_need_buflen (&pwd);
  if (plen > buflen)
    {
      __set_errno (ERANGE);
      return NSS_STATUS_TRYAGAIN;
    }
  p = buffer + (buflen - plen);
  buflen -= plen;

  if (use_nisplus) /* Do the NIS+ query here */
    {
      nis_result *res;
      char buf[1024 + pwdtablelen];

      sprintf(buf, "[uid=%d],%s", uid, pwdtable);
      res = nis_list(buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
      if (niserr2nss (res->status) != NSS_STATUS_SUCCESS)
        {
          enum nss_status status =  niserr2nss (res->status);

          nis_freeresult (res);
          return status;
        }
      if ((parse_res = _nss_nisplus_parse_pwent (res, result, buffer,
                                                 buflen)) == -1)
        {
          nis_freeresult (res);
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
      nis_freeresult (res);
    }
  else /* Use NIS */
    {
      char buf[1024];
      char *domain, *outval, *ptr;
      int outvallen;

      if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
        return NSS_STATUS_TRYAGAIN;

      sprintf (buf, "%d", uid);
      if (yp_match (domain, "passwd.byuid", buf, strlen (buf),
                    &outval, &outvallen)
          != YPERR_SUCCESS)
        return NSS_STATUS_TRYAGAIN;
      ptr = strncpy (buffer, outval, buflen < (size_t) outvallen ?
                     buflen : (size_t) outvallen);
      buffer[buflen < (size_t) outvallen ? buflen : (size_t) outvallen] = '\0';
      free (outval);
      while (isspace (*ptr))
        ptr++;
      if ((parse_res = _nss_files_parse_pwent (ptr, result, data, buflen))
          == -1)
        {
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }
    }

  if (parse_res > 0)
    {
      copy_pwd_changes (result, &pwd, p, plen);
      give_pwd_free (&pwd);
      /* We found the entry.  */
      return NSS_STATUS_SUCCESS;
    }
  else
    {
      /* Give buffer the old len back */
      buflen += plen;
      give_pwd_free (&pwd);
    }
  return NSS_STATUS_RETURN;
}

/* Searches in /etc/passwd and the NIS/NIS+ map for a special user id */
static enum nss_status
internal_getpwuid_r (uid_t uid, struct passwd *result, ent_t *ent,
                     char *buffer, size_t buflen)
{
  struct parser_data *data = (void *) buffer;

  while (1)
    {
      fpos_t pos;
      char *p;
      int parse_res;

      do
        {
          fgetpos (ent->stream, &pos);
          p = fgets (buffer, buflen, ent->stream);
          if (p == NULL)
            return NSS_STATUS_NOTFOUND;

          /* Terminate the line for any case.  */
          buffer[buflen - 1] = '\0';

          /* Skip leading blanks.  */
          while (isspace (*p))
            ++p;
        }
      while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines.  */
             /* Parse the line.  If it is invalid, loop to
                get the next line of the file to parse.  */
             !(parse_res = _nss_files_parse_pwent (p, result, data, buflen)));

      if (parse_res == -1)
        {
          /* The parser ran out of space.  */
          fsetpos (ent->stream, &pos);
          __set_errno (ERANGE);
          return NSS_STATUS_TRYAGAIN;
        }

      /* This is a real entry.  */
      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
        {
          if (result->pw_uid == uid)
            return NSS_STATUS_SUCCESS;
          else
            continue;
        }

      /* -@netgroup */
      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          char buf2[1024];
          char *user, *host, *domain;
          struct __netgrent netgrdata;

          bzero (&netgrdata, sizeof (struct __netgrent));
          __internal_setnetgrent (&result->pw_name[2], &netgrdata);
          while (__internal_getnetgrent_r (&host, &user, &domain,
                                           &netgrdata, buf2, sizeof (buf2)))
            {
              if (user != NULL && user[0] != '-')
                blacklist_store_name (user, ent);
            }
          __internal_endnetgrent (&netgrdata);
          continue;
        }

      /* +@netgroup */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
          && result->pw_name[2] != '\0')
        {
          char buf[strlen (result->pw_name)];
          int status;

          strcpy (buf, &result->pw_name[2]);
          ent->netgroup = TRUE;
          ent->first = TRUE;
          copy_pwd_changes (&ent->pwd, result, NULL, 0);

          do
            {
              if (use_nisplus)
                status = getpwent_next_nisplus_netgr (NULL, result, ent, buf,
                                                      buffer, buflen);
              else
                status = getpwent_next_nis_netgr (NULL, result, ent, buf,
                                                  buffer, buflen);
              if (status == NSS_STATUS_RETURN)
                continue;

              if (status == NSS_STATUS_SUCCESS && uid == result->pw_uid)
                return NSS_STATUS_SUCCESS;
            } while (status == NSS_STATUS_SUCCESS);
          continue;
        }

      /* -user */
      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          blacklist_store_name (&result->pw_name[1], ent);
          continue;
        }

      /* +user */
      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
          && result->pw_name[1] != '@')
        {
          enum nss_status status;

          /* Store the User in the blacklist for the "+" at the end of
             /etc/passwd */
          blacklist_store_name (&result->pw_name[1], ent);
          status = getpwnam_plususer (&result->pw_name[1], result, buffer,
                                      buflen);
          if (status == NSS_STATUS_SUCCESS && result->pw_uid == uid)
            break;
          else
            continue;
        }

      /* +:... */
      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
        {
          enum nss_status status;

          status = getpwuid_plususer (uid, result, buffer, buflen);
          if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
            break;
          else
            if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
              return NSS_STATUS_NOTFOUND;
            else
              return status;
        }
    }
  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_compat_getpwuid_r (uid_t uid, struct passwd *pwd,
                        char *buffer, size_t buflen)
{
  ent_t ent = {0, 0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0},
               {NULL, NULL, 0, 0, NULL, NULL, NULL}};
  enum nss_status status;

  __libc_lock_lock (lock);

  if (ni == NULL)
    {
      __nss_database_lookup ("passwd_compat", NULL, "nis", &ni);
      use_nisplus = (strcmp (ni->name, "nisplus") == 0);
    }

  __libc_lock_unlock (lock);

  status = internal_setpwent (&ent);
  if (status != NSS_STATUS_SUCCESS)
    return status;

  status = internal_getpwuid_r (uid, pwd, &ent, buffer, buflen);

  internal_endpwent (&ent);

  return status;
}


/* Support routines for remembering -@netgroup and -user entries.
   The names are stored in a single string with `|' as separator. */
static void
blacklist_store_name (const char *name, ent_t *ent)
{
  int namelen = strlen (name);
  char *tmp;

  /* first call, setup cache */
  if (ent->blacklist.size == 0)
    {
      ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
      ent->blacklist.data = malloc (ent->blacklist.size);
      if (ent->blacklist.data == NULL)
        return;
      ent->blacklist.data[0] = '|';
      ent->blacklist.data[1] = '\0';
      ent->blacklist.current = 1;
    }
  else
    {
      if (in_blacklist (name, namelen, ent))
        return;                 /* no duplicates */

      if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
        {
          ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
          tmp = realloc (ent->blacklist.data, ent->blacklist.size);
          if (tmp == NULL)
            {
              free (ent->blacklist.data);
              ent->blacklist.size = 0;
              return;
            }
          ent->blacklist.data = tmp;
        }
    }

  tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
  *tmp++ = '|';
  *tmp = '\0';
  ent->blacklist.current += namelen + 1;

  return;
}

/* returns TRUE if ent->blacklist contains name, else FALSE */
static bool_t
in_blacklist (const char *name, int namelen, ent_t *ent)
{
  char buf[namelen + 3];
  char *cp;

  if (ent->blacklist.data == NULL)
    return FALSE;

  buf[0] = '|';
  cp = stpcpy (&buf[1], name);
  *cp++= '|';
  *cp = '\0';
  return strstr (ent->blacklist.data, buf) != NULL;
}