1 /*
2  * FreeRTOS+TCP V3.1.0
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_PARSER_H
29 #define FREERTOS_DNS_PARSER_H
30 
31 /* FreeRTOS includes. */
32 #include "FreeRTOS.h"
33 
34 /* FreeRTOS+TCP includes. */
35 #include "FreeRTOS_IP.h"
36 
37 #include "FreeRTOS_DNS_Globals.h"
38 
39 /* Standard includes. */
40 #include <stdint.h>
41 #if ( ipconfigUSE_DNS != 0 )
42 
43 /** @brief Flag DNS parsing errors in situations where an IPv4 address is the return
44  * type. */
45 
46     #if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
47         size_t DNS_ReadNameField( const uint8_t * pucByte,
48                                   size_t uxRemainingBytes,
49                                   char * pcName,
50                                   size_t uxDestLen );
51     #endif /* ipconfigUSE_DNS_CACHE || ipconfigDNS_USE_CALLBACKS */
52 
53 /*
54  * Simple routine that jumps over the NAME field of a resource record.
55  * It returns the number of bytes read.
56  */
57     size_t DNS_SkipNameField( const uint8_t * pucByte,
58                               size_t uxLength );
59 
60 /*
61  * Process a response packet from a DNS server.
62  * The parameter 'xExpected' indicates whether the identifier in the reply
63  * was expected, and thus if the DNS cache may be updated with the reply.
64  */
65     uint32_t DNS_ParseDNSReply( uint8_t * pucUDPPayloadBuffer,
66                                 size_t uxBufferLength,
67                                 BaseType_t xExpected );
68 
69 /*
70  * The NBNS and the LLMNR protocol share this reply function.
71  */
72     #if ( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) )
73         void prepareReplyDNSMessage( NetworkBufferDescriptor_t * pxNetworkBuffer,
74                                      BaseType_t lNetLength );
75     #endif
76     #if ( ipconfigUSE_NBNS == 1 )
77         void DNS_TreatNBNS( uint8_t * pucPayload,
78                             size_t uxBufferLength,
79                             uint32_t ulIPAddress );
80     #endif
81 
82     uint32_t parseDNSAnswer( const DNSMessage_t * pxDNSMessageHeader,
83                              uint8_t * pucByte,
84                              size_t uxSourceBytesRemaining,
85                              size_t * uxBytesRead
86     #if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
87                                  ,
88                                  const char * pcName,
89                                  BaseType_t xDoStore
90     #endif
91                              );
92 #endif /* if ( ipconfigUSE_DNS != 0 ) */
93 #endif /* ifndef FREERTOS_DNS_PARSER_H */
94