xref: /FreeRTOS-Plus-TCP-v4.0.0/source/include/FreeRTOS_DNS_Cache.h (revision 245d5879903cfc6e52a466fc1067fe54f869740c) 
1 /*
2  * FreeRTOS+TCP <DEVELOPMENT BRANCH>
3  * Copyright (C) 2022 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
4  *
5  * SPDX-License-Identifier: MIT
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy of
8  * this software and associated documentation files (the "Software"), to deal in
9  * the Software without restriction, including without limitation the rights to
10  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11  * the Software, and to permit persons to whom the Software is furnished to do so,
12  * subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in all
15  * copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
20  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
21  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * https://github.com/FreeRTOS
25  * https://www.FreeRTOS.org
26  */
27 
28 #ifndef FREERTOS_DNS_CACHE_H
29 #define FREERTOS_DNS_CACHE_H
30 
31 /* FreeRTOS includes. */
32 #include "FreeRTOS.h"
33 
34 #include "FreeRTOS_DNS_Globals.h"
35 
36 /* Standard includes. */
37 #include <stdint.h>
38 
39 #if ( ( ipconfigUSE_DNS_CACHE == 1 ) && ( ipconfigUSE_DNS != 0 ) )
40 
41 /**
42  * @brief cache entry format structure
43  */
44     typedef struct xDNS_CACHE_TABLE_ROW
45     {
46         IPv46_Address_t xAddresses[ ipconfigDNS_CACHE_ADDRESSES_PER_ENTRY ]; /*!< The IP address(es) of an ARP cache entry. */
47         char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ];                        /*!< The name of the host */
48         uint32_t ulTTL;                                                      /*!< Time-to-Live (in seconds) from the DNS server. */
49         uint32_t ulTimeWhenAddedInSeconds;                                   /*!< time at which the entry was added */
50         #if ( ipconfigDNS_CACHE_ADDRESSES_PER_ENTRY > 1 )
51             uint8_t ucNumIPAddresses;                                        /*!< number of ip addresses for the same entry */
52             uint8_t ucCurrentIPAddress;                                      /*!< current ip address index */
53         #endif
54     } DNSCacheRow_t;
55 
56 /* Look for the indicated host name in the DNS cache. Returns the IPv4
57  * address if present, or 0x0 otherwise. */
58     uint32_t FreeRTOS_dnslookup( const char * pcHostName );
59 
60     void FreeRTOS_dnsclear( void );
61 
62 /**
63  * @brief For debugging only: prints the contents of the DNS cache table.
64  */
65     void vShowDNSCacheTable( void );
66 
67     BaseType_t FreeRTOS_dns_update( const char * pcName,
68                                     IPv46_Address_t * pxIP,
69                                     uint32_t ulTTL,
70                                     BaseType_t xLookUp,
71                                     struct freertos_addrinfo ** ppxAddressInfo );
72 
73     BaseType_t FreeRTOS_ProcessDNSCache( const char * pcName,
74                                          IPv46_Address_t * pxIP,
75                                          uint32_t ulTTL,
76                                          BaseType_t xLookUp,
77                                          struct freertos_addrinfo ** ppxAddressInfo );
78 
79     uint32_t Prepare_CacheLookup( const char * pcHostName,
80                                   BaseType_t xFamily,
81                                   struct freertos_addrinfo ** ppxAddressInfo );
82 #endif /* if ( ipconfigUSE_DNS_CACHE == 1 ) */
83 
84 #endif /* ifndef FREERTOS_DNS_CACHE_H */
85