/* Copyright (C) 1998-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.

   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 <errno.h>

#include <pwd.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/mman.h>

#include <sys/socket.h>

#include <sys/uio.h>

#include <sys/un.h>

#include <not-cancel.h>

#include <_itoa.h>

#include "nscd-client.h"

#include "nscd_proto.h"

int __nss_not_use_nscd_passwd;

static int nscd_getpw_r (const char *key, size_t keylen, request_type type,

			 struct passwd *resultbuf, char *buffer,

			 size_t buflen, struct passwd **result);

int

__nscd_getpwnam_r (const char *name, struct passwd *resultbuf, char *buffer,

		   size_t buflen, struct passwd **result)

{

  if (name == NULL)

    return -1;

  return nscd_getpw_r (name, strlen (name) + 1, GETPWBYNAME, resultbuf,

		       buffer, buflen, result);

}

int

__nscd_getpwuid_r (uid_t uid, struct passwd *resultbuf, char *buffer,

		   size_t buflen, struct passwd **result)

{

  char buf[3 * sizeof (uid_t)];

  buf[sizeof (buf) - 1] = '\0';

  char *cp = _itoa_word (uid, buf + sizeof (buf) - 1, 10, 0);

  return nscd_getpw_r (cp, buf + sizeof (buf) - cp, GETPWBYUID, resultbuf,

		       buffer, buflen, result);

}

libc_locked_map_ptr (static, map_handle);

/* Note that we only free the structure if necessary.  The memory

   mapping is not removed since it is not visible to the malloc

   handling.  */

libc_freeres_fn (pw_map_free)

{

  if (map_handle.mapped != NO_MAPPING)

    {

      void *p = map_handle.mapped;

      map_handle.mapped = NO_MAPPING;

      free (p);

    }

}

static int

nscd_getpw_r (const char *key, size_t keylen, request_type type,

	      struct passwd *resultbuf, char *buffer, size_t buflen,

	      struct passwd **result)

{

  int gc_cycle;

  int nretries = 0;

  /* If the mapping is available, try to search there instead of

     communicating with the nscd.  */

  struct mapped_database *mapped;

  mapped = __nscd_get_map_ref (GETFDPW, "passwd", &map_handle, &gc_cycle);

 retry:;

  const char *pw_name = NULL;

  int retval = -1;

  const char *recend = (const char *) ~UINTMAX_C (0);

  pw_response_header pw_resp;

  if (mapped != NO_MAPPING)

    {

      struct datahead *found = __nscd_cache_search (type, key, keylen, mapped,

						    sizeof pw_resp);

      if (found != NULL)

	{

	  pw_name = (const char *) (&found->data[0].pwdata + 1);

	  pw_resp = found->data[0].pwdata;

	  recend = (const char *) found->data + found->recsize;

	  /* Now check if we can trust pw_resp fields.  If GC is

	     in progress, it can contain anything.  */

	  if (mapped->head->gc_cycle != gc_cycle)

	    {

	      retval = -2;

	      goto out;

	    }

	}

    }

  int sock = -1;

  if (pw_name == NULL)

    {

      sock = __nscd_open_socket (key, keylen, type, &pw_resp,

				 sizeof (pw_resp));

      if (sock == -1)

	{

	  __nss_not_use_nscd_passwd = 1;

	  goto out;

	}

    }

  /* No value found so far.  */

  *result = NULL;

  if (__glibc_unlikely (pw_resp.found == -1))

    {

      /* The daemon does not cache this database.  */

      __nss_not_use_nscd_passwd = 1;

      goto out_close;

    }

  if (pw_resp.found == 1)

    {

      /* Set the information we already have.  */

      resultbuf->pw_uid = pw_resp.pw_uid;

      resultbuf->pw_gid = pw_resp.pw_gid;

      char *p = buffer;

      /* get pw_name */

      resultbuf->pw_name = p;

      p += pw_resp.pw_name_len;

      /* get pw_passwd */

      resultbuf->pw_passwd = p;

      p += pw_resp.pw_passwd_len;

      /* get pw_gecos */

      resultbuf->pw_gecos = p;

      p += pw_resp.pw_gecos_len;

      /* get pw_dir */

      resultbuf->pw_dir = p;

      p += pw_resp.pw_dir_len;

      /* get pw_pshell */

      resultbuf->pw_shell = p;

      p += pw_resp.pw_shell_len;

      ssize_t total = p - buffer;

      if (__glibc_unlikely (pw_name + total > recend))

	goto out_close;

      if (__glibc_unlikely (buflen < total))

	{

	  __set_errno (ERANGE);

	  retval = ERANGE;

	  goto out_close;

	}

      retval = 0;

      if (pw_name == NULL)

	{

	  ssize_t nbytes = __readall (sock, buffer, total);

	  if (__glibc_unlikely (nbytes != total))

	    {

	      /* The `errno' to some value != ERANGE.  */

	      __set_errno (ENOENT);

	      retval = ENOENT;

	    }

	  else

	    *result = resultbuf;

	}

      else

	{

	  /* Copy the various strings.  */

	  memcpy (resultbuf->pw_name, pw_name, total);

	  /* Try to detect corrupt databases.  */

	  if (resultbuf->pw_name[pw_resp.pw_name_len - 1] != '\0'

	      || resultbuf->pw_passwd[pw_resp.pw_passwd_len - 1] != '\0'

	      || resultbuf->pw_gecos[pw_resp.pw_gecos_len - 1] != '\0'

	      || resultbuf->pw_dir[pw_resp.pw_dir_len - 1] != '\0'

	      || resultbuf->pw_shell[pw_resp.pw_shell_len - 1] != '\0')

	    {

	      /* We cannot use the database.  */

	      retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;

	      goto out_close;

	    }

	  *result = resultbuf;

	}

    }

  else

    {

      /* Set errno to 0 to indicate no error, just no found record.  */

      __set_errno (0);

      /* Even though we have not found anything, the result is zero.  */

      retval = 0;

    }

 out_close:

  if (sock != -1)

    __close_nocancel_nostatus (sock);

 out:

  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)

    {

      /* When we come here this means there has been a GC cycle while we

	 were looking for the data.  This means the data might have been

	 inconsistent.  Retry if possible.  */

      if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)

	{

	  /* nscd is just running gc now.  Disable using the mapping.  */

	  if (atomic_decrement_val (&mapped->counter) == 0)

	    __nscd_unmap (mapped);

	  mapped = NO_MAPPING;

	}

      if (retval != -1)

	goto retry;

    }

  return retval;

}