netdb: Move DNS initialization and cache logic to separate files
This commit is contained in:
Gregory Nutt
parent
0889963b50
commit
62f04d98c1
@ -48,7 +48,11 @@ endif
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# Add DNS lookup support
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# Add DNS lookup support
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ifeq ($(CONFIG_NETDB_DNSCLIENT),y)
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ifeq ($(CONFIG_NETDB_DNSCLIENT),y)
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CSRCS += lib_dnsclient.c lib_dnsaddserver.c lib_dnsforeach.c
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CSRCS += lib_dnsinit.c lib_dnsclient.c lib_dnsaddserver.c lib_dnsforeach.c
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ifneq ($(CONFIG_NETDB_DNSCLIENT_ENTRIES),0)
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CSRCS += lib_dnscache.c
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endif
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endif
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endif
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# Add the net directory to the build
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# Add the net directory to the build
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@ -125,6 +125,36 @@ EXTERN bool g_dns_address; /* true: We have the address of the DNS server */
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* Public Function Prototypes
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* Public Function Prototypes
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****************************************************************************/
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****************************************************************************/
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/****************************************************************************
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* Name: dns_initialize
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*
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* Description:
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* Make sure that the DNS client has been properly initialized for use.
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*
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****************************************************************************/
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bool dns_initialize(void);
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/****************************************************************************
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* Name: dns_semtake
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*
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* Description:
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* Take the DNS semaphore, ignoring errors do to the receipt of signals.
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*
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****************************************************************************/
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void dns_semtake(void);
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/****************************************************************************
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* Name: dns_semgive
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*
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* Description:
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* Release the DNS semaphore
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*
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****************************************************************************/
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void dns_semgive(void);
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/****************************************************************************
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/****************************************************************************
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* Name: dns_bind
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* Name: dns_bind
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*
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*
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@ -167,6 +197,27 @@ int dns_bind(void);
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int dns_query(int sd, FAR const char *hostname, FAR struct sockaddr *addr,
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int dns_query(int sd, FAR const char *hostname, FAR struct sockaddr *addr,
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FAR socklen_t *addrlen);
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FAR socklen_t *addrlen);
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/****************************************************************************
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* Name: dns_save_answer
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*
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* Description:
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* Same the last resolved hostname in the DNS cache
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*
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* Input Parameters:
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* hostname - The hostname string to be cached.
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* addr - The IP address associated with the hostname
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* addrlen - The size of the of the IP address.
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
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void dns_save_answer(FAR const char *hostname,
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FAR const struct sockaddr *addr, socklen_t addrlen);
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#endif
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/****************************************************************************
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/****************************************************************************
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* Name: dns_find_answer
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* Name: dns_find_answer
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*
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*
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316
libc/netdb/lib_dnscache.c
Normal file
316
libc/netdb/lib_dnscache.c
Normal file
@ -0,0 +1,316 @@
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/****************************************************************************
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* libc/netdb/lib_dnscache.c
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*
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* Copyright (C) 2007, 2009, 2012, 2014-2016 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/time.h>
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#include <string.h>
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#include <time.h>
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#include <errno.h>
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#include <debug.h>
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#include "netdb/lib_dns.h"
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#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Use clock monotonic, if possible */
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#ifdef CONFIG_CLOCK_MONOTONIC
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# define DNS_CLOCK CLOCK_MONOTONIC
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#else
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# define DNS_CLOCK CLOCK_REALTIME
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#endif
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/****************************************************************************
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* Private Types
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****************************************************************************/
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/* This described one entry in the cache of resolved hostnames */
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struct dns_cache_s
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{
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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time_t ctime; /* Creation time */
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#endif
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char name[CONFIG_NETDB_DNSCLIENT_NAMESIZE];
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union dns_server_u addr; /* Resolved address */
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};
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static uint8_t g_dns_head; /* Head of the circular, DNS resolver cache */
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static uint8_t g_dns_tail; /* Tail of the circular, DNS resolver cache */
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/* This is the DNS resolver cache */
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static struct dns_cache_s g_dns_cache[CONFIG_NETDB_DNSCLIENT_ENTRIES];
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: dns_save_answer
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*
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* Description:
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* Same the last resolved hostname in the DNS cache
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*
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* Input Parameters:
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* hostname - The hostname string to be cached.
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* addr - The IP address associated with the hostname
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* addrlen - The size of the of the IP address.
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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void dns_save_answer(FAR const char *hostname,
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FAR const struct sockaddr *addr, socklen_t addrlen)
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{
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FAR struct dns_cache_s *entry;
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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struct timespec now;
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#endif
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int next;
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int ndx;
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/* Get exclusive access to the DNS cache */
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dns_semtake();
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/* Get the index to the new head of the list */
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ndx = g_dns_head;
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next = ndx + 1;
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if (next >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
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{
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next = 0;
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}
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/* If the next head pointer would match the tail index, then increment
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* the tail index, discarding the oldest mapping in the cache.
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*/
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if (next == g_dns_tail)
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{
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int tmp = g_dns_tail + 1;
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if (tmp >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
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{
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tmp = 0;
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}
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g_dns_tail = tmp;
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}
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/* Save the answer in the cache */
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entry = &g_dns_cache[ndx];
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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/* Get the current time, using CLOCK_MONOTONIC if possible */
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(void)clock_settime(DNS_CLOCK, &now);
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entry->ctime = (time_t)now.tv_sec;
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#endif
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strncpy(entry->name, hostname, CONFIG_NETDB_DNSCLIENT_NAMESIZE);
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memcpy(&entry->addr.addr, addr, addrlen);
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/* Save the updated head index */
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g_dns_head = next;
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dns_semgive();
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}
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/****************************************************************************
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* Name: dns_find_answer
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*
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* Description:
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* Check if we already have the resolved hostname address in the cache.
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*
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* Input Parameters:
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* hostname - The hostname string to be resolved.
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* addr - The location to return the IP address associated with the
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* hostname
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* addrlen - On entry, the size of the buffer backing up the 'addr'
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* pointer. On return, this location will hold the actual size of
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* the returned address.
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*
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* Returned Value:
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* If the host name was successfully found in the DNS name resolution
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* cache, zero (OK) will be returned. Otherwise, some negated errno
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* value will be returned, typically -ENOENT meaning that the hostname
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* was not found in the cache.
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*
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****************************************************************************/
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int dns_find_answer(FAR const char *hostname, FAR struct sockaddr *addr,
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FAR socklen_t *addrlen)
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{
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FAR struct dns_cache_s *entry;
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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struct timespec now;
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uint32_t elapsed;
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int ret;
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#endif
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int next;
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int ndx;
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/* If DNS not initialized, no need to proceed */
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if (!dns_initialize())
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{
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ndbg("ERROR: DNS failed to initialize\n");
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return -EAGAIN;
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}
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/* Get exclusive access to the DNS cache */
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dns_semtake();
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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/* Get the current time, using CLOCK_MONOTONIC if possible */
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ret = clock_settime(DNS_CLOCK, &now);
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#endif
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/* REVISIT: This is not thread safe */
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for (ndx = g_dns_tail; ndx != g_dns_head; ndx = next)
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{
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entry = &g_dns_cache[ndx];
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/* Advance the index for the next time through the loop, handling
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* wrapping to the beginning of the circular buffer.
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*/
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next = ndx + 1;
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if (next >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
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{
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next = 0;
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}
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#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
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/* Check if this entry has expired
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* REVISIT: Does not this calculation assume that the sizeof(time_t)
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* is equal to the sizeof(uint32_t)?
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*/
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elapsed = (uint32_t)now.tv_sec - (uint32_t)entry->ctime;
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if (ret >= 0 && elapsed > CONFIG_NETDB_DNSCLIENT_LIFESEC)
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{
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/* This entry has expired. Increment the tail index to exclude
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* this entry on future traversals.
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*/
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g_dns_tail = next;
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}
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else
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#endif
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{
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/* The entry has not expired, check for a name match. Notice that
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* because the names are truncated to CONFIG_NETDB_DNSCLIENT_NAMESIZE,
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* this has the possibility of aliasing two names and returning
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* the wrong entry from the cache.
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*/
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if (strncmp(hostname, entry->name, CONFIG_NETDB_DNSCLIENT_NAMESIZE) == 0)
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{
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socklen_t inlen;
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/* We have a match. Return the resolved host address */
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#ifdef CONFIG_NET_IPv4
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if (entry->addr.addr.sa_family == AF_INET)
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#ifdef CONFIG_NET_IPv6
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#endif
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{
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inlen = sizeof(struct sockaddr_in);
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}
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#endif
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#ifdef CONFIG_NET_IPv6
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else
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#ifdef CONFIG_NET_IPv4
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#endif
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{
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inlen = sizeof(struct sockaddr_in6);
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}
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#endif
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/* Make sure that the address will fit in the caller-provided
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* buffer.
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*/
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if (*addrlen < inlen)
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{
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ret = -ERANGE;
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goto errout_with_sem;
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}
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/* Return the address information */
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memcpy(addr, &entry->addr.addr, inlen);
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*addrlen = inlen;
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dns_semgive();
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return OK;
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}
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}
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}
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ret = -ENOENT;
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errout_with_sem:
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dns_semgive();
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return ret;
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}
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#endif /* CONFIG_NETDB_DNSCLIENT_ENTRIES > 0 */
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@ -46,20 +46,18 @@
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#include <nuttx/config.h>
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#include <nuttx/config.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/time.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <string.h>
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#include <unistd.h>
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#include <unistd.h>
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#include <semaphore.h>
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#include <string.h>
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#include <time.h>
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#include <errno.h>
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#include <errno.h>
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#include <debug.h>
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#include <debug.h>
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#include <assert.h>
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#include <arpa/inet.h>
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#include <arpa/inet.h>
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#include <netinet/in.h>
|
|
||||||
|
#if 0
|
||||||
|
#include <time.h>
|
||||||
|
|
||||||
|
#endif
|
||||||
|
|
||||||
#include <nuttx/net/dns.h>
|
#include <nuttx/net/dns.h>
|
||||||
|
|
||||||
@ -78,249 +76,20 @@
|
|||||||
#define SEND_BUFFER_SIZE 64
|
#define SEND_BUFFER_SIZE 64
|
||||||
#define RECV_BUFFER_SIZE CONFIG_NETDB_DNSCLIENT_MAXRESPONSE
|
#define RECV_BUFFER_SIZE CONFIG_NETDB_DNSCLIENT_MAXRESPONSE
|
||||||
|
|
||||||
/* Use clock monotonic, if possible */
|
|
||||||
|
|
||||||
#ifdef CONFIG_CLOCK_MONOTONIC
|
|
||||||
# define DNS_CLOCK CLOCK_MONOTONIC
|
|
||||||
#else
|
|
||||||
# define DNS_CLOCK CLOCK_REALTIME
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/****************************************************************************
|
/****************************************************************************
|
||||||
* Private Types
|
* Private Types
|
||||||
****************************************************************************/
|
****************************************************************************/
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
|
|
||||||
/* This described one entry in the cache of resolved hostnames */
|
|
||||||
|
|
||||||
struct dns_cache_s
|
|
||||||
{
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
time_t ctime; /* Creation time */
|
|
||||||
#endif
|
|
||||||
char name[CONFIG_NETDB_DNSCLIENT_NAMESIZE];
|
|
||||||
union dns_server_u addr; /* Resolved address */
|
|
||||||
};
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/****************************************************************************
|
/****************************************************************************
|
||||||
* Private Data
|
* Private Data
|
||||||
****************************************************************************/
|
****************************************************************************/
|
||||||
|
|
||||||
static sem_t g_dns_sem; /* Protects g_seqno and DNS cache */
|
|
||||||
static bool g_dns_initialized; /* DNS data structures initialized */
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
|
|
||||||
static uint8_t g_dns_head; /* Head of the circular, DNS resolver cache */
|
|
||||||
static uint8_t g_dns_tail; /* Tail of the circular, DNS resolver cache */
|
|
||||||
#endif
|
|
||||||
static uint8_t g_seqno; /* Sequence number of the next request */
|
static uint8_t g_seqno; /* Sequence number of the next request */
|
||||||
|
|
||||||
#ifdef CONFIG_NETDB_DNSSERVER_IPv6
|
|
||||||
/* 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
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
|
|
||||||
/* This is the DNS resolver cache */
|
|
||||||
|
|
||||||
static struct dns_cache_s g_dns_cache[CONFIG_NETDB_DNSCLIENT_ENTRIES];
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/****************************************************************************
|
/****************************************************************************
|
||||||
* Private Functions
|
* Private Functions
|
||||||
****************************************************************************/
|
****************************************************************************/
|
||||||
|
|
||||||
/****************************************************************************
|
|
||||||
* Name: dns_semtake
|
|
||||||
*
|
|
||||||
* Description:
|
|
||||||
* Take the DNS semaphore, ignoring errors do to the receipt of signals.
|
|
||||||
*
|
|
||||||
****************************************************************************/
|
|
||||||
|
|
||||||
static void dns_semtake(void)
|
|
||||||
{
|
|
||||||
int errcode = 0;
|
|
||||||
int ret;
|
|
||||||
|
|
||||||
do
|
|
||||||
{
|
|
||||||
ret = sem_wait(&g_dns_sem);
|
|
||||||
if (ret < 0)
|
|
||||||
{
|
|
||||||
errcode = get_errno();
|
|
||||||
DEBUGASSERT(errcode == EINTR);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
while (ret < 0 && errcode == EINTR);
|
|
||||||
}
|
|
||||||
|
|
||||||
/****************************************************************************
|
|
||||||
* Name: dns_semgive
|
|
||||||
*
|
|
||||||
* Description:
|
|
||||||
* Release the DNS semaphore
|
|
||||||
*
|
|
||||||
****************************************************************************/
|
|
||||||
|
|
||||||
#define dns_semgive() sem_post(&g_dns_sem)
|
|
||||||
|
|
||||||
/****************************************************************************
|
|
||||||
* Name: dns_initialize
|
|
||||||
*
|
|
||||||
* Description:
|
|
||||||
* Make sure that the DNS client has been properly initialized for use.
|
|
||||||
*
|
|
||||||
****************************************************************************/
|
|
||||||
|
|
||||||
static bool dns_initialize(void)
|
|
||||||
{
|
|
||||||
/* Have DNS data structures been initialized? */
|
|
||||||
|
|
||||||
if (!g_dns_initialized)
|
|
||||||
{
|
|
||||||
sem_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 /* !ONFIG_NETDB_RESOLVCONF */
|
|
||||||
|
|
||||||
return true;
|
|
||||||
}
|
|
||||||
|
|
||||||
/****************************************************************************
|
|
||||||
* Name: dns_save_answer
|
|
||||||
*
|
|
||||||
* Description:
|
|
||||||
* Same the last resolved hostname in the DNS cache
|
|
||||||
*
|
|
||||||
* Input Parameters:
|
|
||||||
* hostname - The hostname string to be cached.
|
|
||||||
* addr - The IP address associated with the hostname
|
|
||||||
* addrlen - The size of the of the IP address.
|
|
||||||
*
|
|
||||||
* Returned Value:
|
|
||||||
* None
|
|
||||||
*
|
|
||||||
****************************************************************************/
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
|
|
||||||
static void dns_save_answer(FAR const char *hostname,
|
|
||||||
FAR const struct sockaddr *addr,
|
|
||||||
socklen_t addrlen)
|
|
||||||
{
|
|
||||||
FAR struct dns_cache_s *entry;
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
struct timespec now;
|
|
||||||
#endif
|
|
||||||
int next;
|
|
||||||
int ndx;
|
|
||||||
|
|
||||||
/* Get exclusive access to the DNS cache */
|
|
||||||
|
|
||||||
dns_semtake();
|
|
||||||
|
|
||||||
/* Get the index to the new head of the list */
|
|
||||||
|
|
||||||
ndx = g_dns_head;
|
|
||||||
next = ndx + 1;
|
|
||||||
if (next >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
|
|
||||||
{
|
|
||||||
next = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* If the next head pointer would match the tail index, then increment
|
|
||||||
* the tail index, discarding the oldest mapping in the cache.
|
|
||||||
*/
|
|
||||||
|
|
||||||
if (next == g_dns_tail)
|
|
||||||
{
|
|
||||||
int tmp = g_dns_tail + 1;
|
|
||||||
if (tmp >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
|
|
||||||
{
|
|
||||||
tmp = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
g_dns_tail = tmp;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Save the answer in the cache */
|
|
||||||
|
|
||||||
entry = &g_dns_cache[ndx];
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
/* Get the current time, using CLOCK_MONOTONIC if possible */
|
|
||||||
|
|
||||||
(void)clock_settime(DNS_CLOCK, &now);
|
|
||||||
entry->ctime = (time_t)now.tv_sec;
|
|
||||||
#endif
|
|
||||||
|
|
||||||
strncpy(entry->name, hostname, CONFIG_NETDB_DNSCLIENT_NAMESIZE);
|
|
||||||
memcpy(&entry->addr.addr, addr, addrlen);
|
|
||||||
|
|
||||||
/* Save the updated head index */
|
|
||||||
|
|
||||||
g_dns_head = next;
|
|
||||||
dns_semgive();
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/****************************************************************************
|
/****************************************************************************
|
||||||
* Name: dns_parse_name
|
* Name: dns_parse_name
|
||||||
*
|
*
|
||||||
@ -859,148 +628,3 @@ int dns_query(int sd, FAR const char *hostname, FAR struct sockaddr *addr,
|
|||||||
|
|
||||||
return -ETIMEDOUT;
|
return -ETIMEDOUT;
|
||||||
}
|
}
|
||||||
|
|
||||||
/****************************************************************************
|
|
||||||
* Name: dns_find_answer
|
|
||||||
*
|
|
||||||
* Description:
|
|
||||||
* Check if we already have the resolved hostname address in the cache.
|
|
||||||
*
|
|
||||||
* Input Parameters:
|
|
||||||
* hostname - The hostname string to be resolved.
|
|
||||||
* addr - The location to return the IP address associated with the
|
|
||||||
* hostname
|
|
||||||
* addrlen - On entry, the size of the buffer backing up the 'addr'
|
|
||||||
* pointer. On return, this location will hold the actual size of
|
|
||||||
* the returned address.
|
|
||||||
*
|
|
||||||
* Returned Value:
|
|
||||||
* If the host name was successfully found in the DNS name resolution
|
|
||||||
* cache, zero (OK) will be returned. Otherwise, some negated errno
|
|
||||||
* value will be returned, typically -ENOENT meaning that the hostname
|
|
||||||
* was not found in the cache.
|
|
||||||
*
|
|
||||||
****************************************************************************/
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_ENTRIES > 0
|
|
||||||
int dns_find_answer(FAR const char *hostname, FAR struct sockaddr *addr,
|
|
||||||
FAR socklen_t *addrlen)
|
|
||||||
{
|
|
||||||
FAR struct dns_cache_s *entry;
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
struct timespec now;
|
|
||||||
uint32_t elapsed;
|
|
||||||
int ret;
|
|
||||||
#endif
|
|
||||||
int next;
|
|
||||||
int ndx;
|
|
||||||
|
|
||||||
/* If DNS not initialized, no need to proceed */
|
|
||||||
|
|
||||||
if (!g_dns_initialized)
|
|
||||||
{
|
|
||||||
ndbg("ERROR: DNS not initialized yet\n");
|
|
||||||
return -EAGAIN;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Get exclusive access to the DNS cache */
|
|
||||||
|
|
||||||
dns_semtake();
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
/* Get the current time, using CLOCK_MONOTONIC if possible */
|
|
||||||
|
|
||||||
ret = clock_settime(DNS_CLOCK, &now);
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/* REVISIT: This is not thread safe */
|
|
||||||
|
|
||||||
for (ndx = g_dns_tail; ndx != g_dns_head; ndx = next)
|
|
||||||
{
|
|
||||||
entry = &g_dns_cache[ndx];
|
|
||||||
|
|
||||||
/* Advance the index for the next time through the loop, handling
|
|
||||||
* wrapping to the beginning of the circular buffer.
|
|
||||||
*/
|
|
||||||
|
|
||||||
next = ndx + 1;
|
|
||||||
if (next >= CONFIG_NETDB_DNSCLIENT_ENTRIES)
|
|
||||||
{
|
|
||||||
next = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
#if CONFIG_NETDB_DNSCLIENT_LIFESEC > 0
|
|
||||||
/* Check if this entry has expired
|
|
||||||
* REVISIT: Does not this calculation assume that the sizeof(time_t)
|
|
||||||
* is equal to the sizeof(uint32_t)?
|
|
||||||
*/
|
|
||||||
|
|
||||||
elapsed = (uint32_t)now.tv_sec - (uint32_t)entry->ctime;
|
|
||||||
if (ret >= 0 && elapsed > CONFIG_NETDB_DNSCLIENT_LIFESEC)
|
|
||||||
{
|
|
||||||
/* This entry has expired. Increment the tail index to exclude
|
|
||||||
* this entry on future traversals.
|
|
||||||
*/
|
|
||||||
|
|
||||||
g_dns_tail = next;
|
|
||||||
}
|
|
||||||
else
|
|
||||||
#endif
|
|
||||||
{
|
|
||||||
/* The entry has not expired, check for a name match. Notice that
|
|
||||||
* because the names are truncated to CONFIG_NETDB_DNSCLIENT_NAMESIZE,
|
|
||||||
* this has the possibility of aliasing two names and returning
|
|
||||||
* the wrong entry from the cache.
|
|
||||||
*/
|
|
||||||
|
|
||||||
if (strncmp(hostname, entry->name, CONFIG_NETDB_DNSCLIENT_NAMESIZE) == 0)
|
|
||||||
{
|
|
||||||
socklen_t inlen;
|
|
||||||
|
|
||||||
/* We have a match. Return the resolved host address */
|
|
||||||
|
|
||||||
#ifdef CONFIG_NET_IPv4
|
|
||||||
if (entry->addr.addr.sa_family == AF_INET)
|
|
||||||
#ifdef CONFIG_NET_IPv6
|
|
||||||
#endif
|
|
||||||
{
|
|
||||||
inlen = sizeof(struct sockaddr_in);
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|
||||||
#ifdef CONFIG_NET_IPv6
|
|
||||||
else
|
|
||||||
#ifdef CONFIG_NET_IPv4
|
|
||||||
#endif
|
|
||||||
{
|
|
||||||
inlen = sizeof(struct sockaddr_in6);
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
/* Make sure that the address will fit in the caller-provided
|
|
||||||
* buffer.
|
|
||||||
*/
|
|
||||||
|
|
||||||
if (*addrlen < inlen)
|
|
||||||
{
|
|
||||||
ret = -ERANGE;
|
|
||||||
goto errout_with_sem;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Return the address information */
|
|
||||||
|
|
||||||
memcpy(addr, &entry->addr.addr, inlen);
|
|
||||||
*addrlen = inlen;
|
|
||||||
|
|
||||||
dns_semgive();
|
|
||||||
return OK;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
ret = -ENOENT;
|
|
||||||
|
|
||||||
errout_with_sem:
|
|
||||||
dns_semgive();
|
|
||||||
return ret;
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|||||||
184
libc/netdb/lib_dnsinit.c
Normal file
184
libc/netdb/lib_dnsinit.c
Normal file
@ -0,0 +1,184 @@
|
|||||||
|
/****************************************************************************
|
||||||
|
* libc/netdb/lib_dnscache.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 <semaphore.h>
|
||||||
|
#include <errno.h>
|
||||||
|
#include <assert.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)
|
||||||
|
{
|
||||||
|
sem_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 = get_errno();
|
||||||
|
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));
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue
Block a user