incubator-nuttx/libc/netdb/lib_dnsbind.c

124 lines
3.9 KiB
C

/****************************************************************************
* libc/netdb/lib_dnsclien.c
*
* Copyright (C) 2007, 2009, 2012, 2014-2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/time.h>
#include <unistd.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/net/dns.h>
#include "netdb/lib_dns.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#if CONFIG_NSOCKET_DESCRIPTORS < 1
# error CONFIG_NSOCKET_DESCRIPTORS must be greater than zero
#endif
#if CONFIG_NET_SOCKOPTS < 1
# error CONFIG_NET_SOCKOPTS required by this logic
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: dns_bind
*
* Description:
* Initialize the DNS resolver and return a socket bound to the DNS name
* server. The name server was previously selected via dns_server().
*
* Input Parameters:
* None
*
* Returned Value:
* On success, the bound, non-negative socket descriptor is returned. A
* negated errno value is returned on any failure.
*
****************************************************************************/
int dns_bind(void)
{
struct timeval tv;
int errcode;
int sd;
int ret;
/* Has the DNS client been properly initialized? */
if (!dns_initialize())
{
nerr("ERROR: DNS client has not been initialized\n");
return -EDESTADDRREQ;
}
/* Create a new socket */
sd = socket(PF_INET, SOCK_DGRAM, 0);
if (sd < 0)
{
errcode = get_errno();
nerr("ERROR: socket() failed: %d\n", errcode);
return -errcode;
}
/* Set up a receive timeout */
tv.tv_sec = 30;
tv.tv_usec = 0;
ret = setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(struct timeval));
if (ret < 0)
{
errcode = get_errno();
nerr("ERROR: setsockopt() failed: %d\n", errcode);
close(sd);
return -errcode;
}
return sd;
}