nuttx/libc/netdb/lib_dnsinit.c

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/****************************************************************************
* libc/netdb/lib_dnscache.c
*
* Copyright (C) 2007, 2009, 2012, 2014-2017 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 <string.h>
#include <semaphore.h>
#include <errno.h>
#include <assert.h>
2016-01-14 22:12:42 +01:00
#include <arpa/inet.h>
#include <nuttx/semaphore.h>
#include "netdb/lib_dns.h"
/****************************************************************************
* Private Data
****************************************************************************/
static sem_t g_dns_sem; /* Protects g_seqno and DNS cache */
static bool g_dns_initialized; /* DNS data structures initialized */
/****************************************************************************
* Public Data
****************************************************************************/
#if defined(CONFIG_NETDB_DNSSERVER_IPv6) && !defined(CONFIG_NETDB_RESOLVCONF)
/* This is the default IPv6 DNS server address */
static const uint16_t g_ipv6_hostaddr[8] =
{
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_1),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_2),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_3),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_4),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_5),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_6),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_7),
HTONS(CONFIG_NETDB_DNSSERVER_IPv6ADDR_8)
};
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: dns_initialize
*
* Description:
* Make sure that the DNS client has been properly initialized for use.
*
****************************************************************************/
bool dns_initialize(void)
{
/* Have DNS data structures been initialized? */
if (!g_dns_initialized)
{
(void)nxsem_init(&g_dns_sem, 0, 1);
g_dns_initialized = true;
}
#ifndef CONFIG_NETDB_RESOLVCONF
/* Has the DNS server IP address been assigned? */
if (!g_dns_address)
{
#if defined(CONFIG_NETDB_DNSSERVER_IPv4)
struct sockaddr_in addr4;
int ret;
/* No, configure the default IPv4 DNS server address */
addr4.sin_family = AF_INET;
addr4.sin_port = HTONS(DNS_DEFAULT_PORT);
addr4.sin_addr.s_addr = HTONL(CONFIG_NETDB_DNSSERVER_IPv4ADDR);
ret = dns_add_nameserver((FAR struct sockaddr *)&addr4,
sizeof(struct sockaddr_in));
if (ret < 0)
{
return false;
}
#elif defined(CONFIG_NETDB_DNSSERVER_IPv6)
struct sockaddr_in6 addr6;
int ret;
/* No, configure the default IPv6 DNS server address */
addr6.sin6_family = AF_INET6;
addr6.sin6_port = HTONS(DNS_DEFAULT_PORT);
memcpy(addr6.sin6_addr.s6_addr, g_ipv6_hostaddr, 16);
ret = dns_add_nameserver((FAR struct sockaddr *)&addr6,
sizeof(struct sockaddr_in6));
if (ret < 0)
{
return false;
}
#else
/* Then we are not ready to perform DNS queries */
return false;
#endif
}
#endif /* !CONFIG_NETDB_RESOLVCONF */
return true;
}
/****************************************************************************
* Name: dns_semtake
*
* Description:
* Take the DNS semaphore, ignoring errors do to the receipt of signals.
*
****************************************************************************/
void dns_semtake(void)
{
int errcode = 0;
int ret;
do
{
ret = _SEM_WAIT(&g_dns_sem);
if (ret < 0)
{
errcode = SEM_ERRNO(ret);
DEBUGASSERT(errcode == EINTR);
}
}
while (ret < 0 && errcode == EINTR);
}
/****************************************************************************
* Name: dns_semgive
*
* Description:
* Release the DNS semaphore
*
****************************************************************************/
void dns_semgive(void)
{
DEBUGVERIFY(_SEM_POST(&g_dns_sem));
}