/*
   nslcd-prot.c - common functions for NSLCD lookups

   Copyright (C) 2006 West Consulting
   Copyright (C) 2006, 2007, 2008, 2009, 2010, 2012 Arthur de Jong

   This 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.

   This 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 this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301 USA
*/

#include "config.h"

#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif /* HAVE_STDINT_H */
#include <unistd.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>

#include "nslcd.h"
#include "nslcd-prot.h"
#include "compat/socket.h"

/* read timeout is 60 seconds because looking up stuff may take some time
   write timeout is 10 secods because nslcd could be loaded with requests */
#define READ_TIMEOUT 60 * 1000
#define WRITE_TIMEOUT 10 * 1000

/* buffer sizes for I/O */
#define READBUFFER_MINSIZE 1024
#define READBUFFER_MAXSIZE 2 * 1024 * 1024
#define WRITEBUFFER_MINSIZE 32
#define WRITEBUFFER_MAXSIZE 32

/* Note that the READBUFFER_MAXSIZE should be large enough to hold any single
   result entity as defined in nslcd.h because the get*ent() functions expect
   to be able to tio_reset() the stream to re-read the current entity.
   Since group entities can grow arbitrarily large, this setting limits the
   number of users that can be put in a group. */

/* returns a socket to the server or NULL on error (see errno),
   socket should be closed with fclose() */
TFILE *nslcd_client_open()
{
  int sock;
  struct sockaddr_un addr;
  TFILE *fp;
  int flags;
  /* create a socket */
  if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
    return NULL;
  /* create socket address structure */
  memset(&addr, 0, sizeof(struct sockaddr_un));
  addr.sun_family = AF_UNIX;
  strncpy(addr.sun_path, NSLCD_SOCKET, sizeof(addr.sun_path));
  addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
  /* close the file descriptor on exec (ignore errors) */
  flags = fcntl(sock, F_GETFL);
  if (flags >= 0)
    (void)fcntl(sock, F_SETFD, flags | FD_CLOEXEC);
  /* connect to the socket */
  if (connect(sock, (struct sockaddr *)&addr, SUN_LEN(&addr)) < 0)
  {
    (void)close(sock);
    return NULL;
  }
  /* create a stream object */
  if ((fp = tio_fdopen(sock, READ_TIMEOUT, WRITE_TIMEOUT,
                       READBUFFER_MINSIZE, READBUFFER_MAXSIZE,
                       WRITEBUFFER_MINSIZE, WRITEBUFFER_MAXSIZE)) == NULL)
  {
    (void)close(sock);
    return NULL;
  }
  /* return the stream */
  return fp;
}