1425 lines
45 KiB
C
1425 lines
45 KiB
C
/*
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* FreeRTOS+TCP V2.0.11
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* Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://aws.amazon.com/freertos
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* http://www.FreeRTOS.org
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*/
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/* Standard includes. */
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#include <stdint.h>
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/* FreeRTOS includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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#include "queue.h"
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#include "list.h"
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#include "semphr.h"
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/* FreeRTOS+TCP includes. */
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#include "FreeRTOS_IP.h"
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#include "FreeRTOS_Sockets.h"
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#include "FreeRTOS_IP_Private.h"
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#include "FreeRTOS_UDP_IP.h"
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#include "FreeRTOS_DNS.h"
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#include "NetworkBufferManagement.h"
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#include "NetworkInterface.h"
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#include "IPTraceMacroDefaults.h"
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/* Exclude the entire file if DNS is not enabled. */
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#if( ipconfigUSE_DNS != 0 )
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#if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN )
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#define dnsDNS_PORT 0x3500
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#define dnsONE_QUESTION 0x0100
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#define dnsOUTGOING_FLAGS 0x0001 /* Standard query. */
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#define dnsRX_FLAGS_MASK 0x0f80 /* The bits of interest in the flags field of incoming DNS messages. */
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#define dnsEXPECTED_RX_FLAGS 0x0080 /* Should be a response, without any errors. */
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#else
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#define dnsDNS_PORT 0x0035
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#define dnsONE_QUESTION 0x0001
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#define dnsOUTGOING_FLAGS 0x0100 /* Standard query. */
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#define dnsRX_FLAGS_MASK 0x800f /* The bits of interest in the flags field of incoming DNS messages. */
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#define dnsEXPECTED_RX_FLAGS 0x8000 /* Should be a response, without any errors. */
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#endif /* ipconfigBYTE_ORDER */
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/* The maximum number of times a DNS request should be sent out if a response
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is not received, before giving up. */
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#ifndef ipconfigDNS_REQUEST_ATTEMPTS
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#define ipconfigDNS_REQUEST_ATTEMPTS 5
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#endif
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/* If the top two bits in the first character of a name field are set then the
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name field is an offset to the string, rather than the string itself. */
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#define dnsNAME_IS_OFFSET ( ( uint8_t ) 0xc0 )
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/* NBNS flags. */
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#define dnsNBNS_FLAGS_RESPONSE 0x8000
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#define dnsNBNS_FLAGS_OPCODE_MASK 0x7800
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#define dnsNBNS_FLAGS_OPCODE_QUERY 0x0000
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#define dnsNBNS_FLAGS_OPCODE_REGISTRATION 0x2800
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/* Host types. */
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#define dnsTYPE_A_HOST 0x01
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#define dnsCLASS_IN 0x01
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/* LLMNR constants. */
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#define dnsLLMNR_TTL_VALUE 300000
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#define dnsLLMNR_FLAGS_IS_REPONSE 0x8000
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/* NBNS constants. */
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#define dnsNBNS_TTL_VALUE 3600 /* 1 hour valid */
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#define dnsNBNS_TYPE_NET_BIOS 0x0020
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#define dnsNBNS_CLASS_IN 0x01
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#define dnsNBNS_NAME_FLAGS 0x6000
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#define dnsNBNS_ENCODED_NAME_LENGTH 32
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/* If the queried NBNS name matches with the device's name,
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the query will be responded to with these flags: */
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#define dnsNBNS_QUERY_RESPONSE_FLAGS ( 0x8500 )
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/* Flag DNS parsing errors in situations where an IPv4 address is the return
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type. */
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#define dnsPARSE_ERROR 0UL
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/*
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* Create a socket and bind it to the standard DNS port number. Return the
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* the created socket - or NULL if the socket could not be created or bound.
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*/
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static Socket_t prvCreateDNSSocket( void );
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/*
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* Create the DNS message in the zero copy buffer passed in the first parameter.
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*/
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static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, const char *pcHostName, TickType_t xIdentifier );
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/*
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* Simple routine that jumps over the NAME field of a resource record.
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*/
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static uint8_t *prvSkipNameField( uint8_t *pucByte, size_t xSourceLen );
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/*
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* Process a response packet from a DNS server.
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*/
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static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, size_t xBufferLength, TickType_t xIdentifier );
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/*
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* Prepare and send a message to a DNS server. 'xReadTimeOut_ms' will be passed as
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* zero, in case the user has supplied a call-back function.
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*/
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static uint32_t prvGetHostByName( const char *pcHostName, TickType_t xIdentifier, TickType_t xReadTimeOut_ms );
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/*
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* The NBNS and the LLMNR protocol share this reply function.
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*/
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#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) )
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static void prvReplyDNSMessage( NetworkBufferDescriptor_t *pxNetworkBuffer, BaseType_t lNetLength );
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#endif
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#if( ipconfigUSE_NBNS == 1 )
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static portINLINE void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, size_t xBufferLength, uint32_t ulIPAddress );
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#endif /* ipconfigUSE_NBNS */
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#if( ipconfigUSE_DNS_CACHE == 1 )
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static uint8_t *prvReadNameField( uint8_t *pucByte, size_t xSourceLen, char *pcName, size_t xLen );
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static void prvProcessDNSCache( const char *pcName, uint32_t *pulIP, uint32_t ulTTL, BaseType_t xLookUp );
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typedef struct xDNS_CACHE_TABLE_ROW
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{
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uint32_t ulIPAddress; /* The IP address of an ARP cache entry. */
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char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ]; /* The name of the host */
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uint32_t ulTTL; /* Time-to-Live (in seconds) from the DNS server. */
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uint32_t ulTimeWhenAddedInSeconds;
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} DNSCacheRow_t;
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static DNSCacheRow_t xDNSCache[ ipconfigDNS_CACHE_ENTRIES ];
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#endif /* ipconfigUSE_DNS_CACHE == 1 */
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#if( ipconfigUSE_LLMNR == 1 )
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const MACAddress_t xLLMNR_MacAdress = { { 0x01, 0x00, 0x5e, 0x00, 0x00, 0xfc } };
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#endif /* ipconfigUSE_LLMNR == 1 */
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/*-----------------------------------------------------------*/
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#include "pack_struct_start.h"
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struct xDNSMessage
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{
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uint16_t usIdentifier;
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uint16_t usFlags;
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uint16_t usQuestions;
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uint16_t usAnswers;
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uint16_t usAuthorityRRs;
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uint16_t usAdditionalRRs;
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}
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#include "pack_struct_end.h"
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typedef struct xDNSMessage DNSMessage_t;
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/* A DNS query consists of a header, as described in 'struct xDNSMessage'
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It is followed by 1 or more queries, each one consisting of a name and a tail,
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with two fields: type and class
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*/
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#include "pack_struct_start.h"
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struct xDNSTail
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{
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uint16_t usType;
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uint16_t usClass;
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}
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#include "pack_struct_end.h"
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typedef struct xDNSTail DNSTail_t;
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/* DNS answer record header. */
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#include "pack_struct_start.h"
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struct xDNSAnswerRecord
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{
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uint16_t usType;
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uint16_t usClass;
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uint32_t ulTTL;
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uint16_t usDataLength;
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}
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#include "pack_struct_end.h"
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typedef struct xDNSAnswerRecord DNSAnswerRecord_t;
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#if( ipconfigUSE_LLMNR == 1 )
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#include "pack_struct_start.h"
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struct xLLMNRAnswer
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{
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uint8_t ucNameCode;
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uint8_t ucNameOffset; /* The name is not repeated in the answer, only the offset is given with "0xc0 <offs>" */
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uint16_t usType;
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uint16_t usClass;
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uint32_t ulTTL;
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uint16_t usDataLength;
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uint32_t ulIPAddress;
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}
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#include "pack_struct_end.h"
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typedef struct xLLMNRAnswer LLMNRAnswer_t;
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#endif /* ipconfigUSE_LLMNR == 1 */
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#if( ipconfigUSE_NBNS == 1 )
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#include "pack_struct_start.h"
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struct xNBNSRequest
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{
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uint16_t usRequestId;
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uint16_t usFlags;
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uint16_t ulRequestCount;
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uint16_t usAnswerRSS;
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uint16_t usAuthRSS;
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uint16_t usAdditionalRSS;
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uint8_t ucNameSpace;
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uint8_t ucName[ dnsNBNS_ENCODED_NAME_LENGTH ];
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uint8_t ucNameZero;
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uint16_t usType;
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uint16_t usClass;
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}
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#include "pack_struct_end.h"
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typedef struct xNBNSRequest NBNSRequest_t;
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#include "pack_struct_start.h"
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struct xNBNSAnswer
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{
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uint16_t usType;
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uint16_t usClass;
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uint32_t ulTTL;
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uint16_t usDataLength;
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uint16_t usNbFlags; /* NetBIOS flags 0x6000 : IP-address, big-endian */
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uint32_t ulIPAddress;
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}
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#include "pack_struct_end.h"
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typedef struct xNBNSAnswer NBNSAnswer_t;
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#endif /* ipconfigUSE_NBNS == 1 */
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/*-----------------------------------------------------------*/
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#if( ipconfigUSE_DNS_CACHE == 1 )
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uint32_t FreeRTOS_dnslookup( const char *pcHostName )
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{
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uint32_t ulIPAddress = 0UL;
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prvProcessDNSCache( pcHostName, &ulIPAddress, 0, pdTRUE );
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return ulIPAddress;
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}
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#endif /* ipconfigUSE_DNS_CACHE == 1 */
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/*-----------------------------------------------------------*/
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#if( ipconfigDNS_USE_CALLBACKS != 0 )
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typedef struct xDNS_Callback {
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TickType_t xRemaningTime; /* Timeout in ms */
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FOnDNSEvent pCallbackFunction; /* Function to be called when the address has been found or when a timeout has beeen reached */
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TimeOut_t xTimeoutState;
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void *pvSearchID;
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struct xLIST_ITEM xListItem;
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char pcName[ 1 ];
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} DNSCallback_t;
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static List_t xCallbackList;
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/* Define FreeRTOS_gethostbyname() as a normal blocking call. */
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uint32_t FreeRTOS_gethostbyname( const char *pcHostName )
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{
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return FreeRTOS_gethostbyname_a( pcHostName, ( FOnDNSEvent ) NULL, ( void* )NULL, 0 );
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}
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/*-----------------------------------------------------------*/
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/* Initialise the list of call-back structures. */
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void vDNSInitialise( void );
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void vDNSInitialise( void )
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{
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vListInitialise( &xCallbackList );
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}
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/*-----------------------------------------------------------*/
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/* Iterate through the list of call-back structures and remove
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old entries which have reached a timeout.
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As soon as the list hase become empty, the DNS timer will be stopped
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In case pvSearchID is supplied, the user wants to cancel a DNS request
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*/
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void vDNSCheckCallBack( void *pvSearchID );
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void vDNSCheckCallBack( void *pvSearchID )
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{
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const ListItem_t *pxIterator;
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const MiniListItem_t* xEnd = ( const MiniListItem_t* )listGET_END_MARKER( &xCallbackList );
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vTaskSuspendAll();
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{
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for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd );
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pxIterator != ( const ListItem_t * ) xEnd;
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)
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{
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DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator );
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/* Move to the next item because we might remove this item */
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pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator );
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if( ( pvSearchID != NULL ) && ( pvSearchID == pxCallback->pvSearchID ) )
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{
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uxListRemove( &pxCallback->xListItem );
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vPortFree( pxCallback );
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}
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else if( xTaskCheckForTimeOut( &pxCallback->xTimeoutState, &pxCallback->xRemaningTime ) != pdFALSE )
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{
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pxCallback->pCallbackFunction( pxCallback->pcName, pxCallback->pvSearchID, 0 );
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uxListRemove( &pxCallback->xListItem );
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vPortFree( ( void * ) pxCallback );
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}
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}
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}
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xTaskResumeAll();
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if( listLIST_IS_EMPTY( &xCallbackList ) )
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{
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vIPSetDnsTimerEnableState( pdFALSE );
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}
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}
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/*-----------------------------------------------------------*/
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void FreeRTOS_gethostbyname_cancel( void *pvSearchID )
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{
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/* _HT_ Should better become a new API call to have the IP-task remove the callback */
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vDNSCheckCallBack( pvSearchID );
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}
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/*-----------------------------------------------------------*/
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/* FreeRTOS_gethostbyname_a() was called along with callback parameters.
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Store them in a list for later reference. */
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static void vDNSSetCallBack( const char *pcHostName, void *pvSearchID, FOnDNSEvent pCallbackFunction, TickType_t xTimeout, TickType_t xIdentifier );
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static void vDNSSetCallBack( const char *pcHostName, void *pvSearchID, FOnDNSEvent pCallbackFunction, TickType_t xTimeout, TickType_t xIdentifier )
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{
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size_t lLength = strlen( pcHostName );
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DNSCallback_t *pxCallback = ( DNSCallback_t * )pvPortMalloc( sizeof( *pxCallback ) + lLength );
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/* Translate from ms to number of clock ticks. */
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xTimeout /= portTICK_PERIOD_MS;
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if( pxCallback != NULL )
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{
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if( listLIST_IS_EMPTY( &xCallbackList ) )
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{
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/* This is the first one, start the DNS timer to check for timeouts */
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vIPReloadDNSTimer( FreeRTOS_min_uint32( 1000U, xTimeout ) );
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}
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strcpy( pxCallback->pcName, pcHostName );
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pxCallback->pCallbackFunction = pCallbackFunction;
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pxCallback->pvSearchID = pvSearchID;
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pxCallback->xRemaningTime = xTimeout;
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vTaskSetTimeOutState( &pxCallback->xTimeoutState );
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listSET_LIST_ITEM_OWNER( &( pxCallback->xListItem ), ( void* ) pxCallback );
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listSET_LIST_ITEM_VALUE( &( pxCallback->xListItem ), xIdentifier );
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vTaskSuspendAll();
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{
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vListInsertEnd( &xCallbackList, &pxCallback->xListItem );
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}
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xTaskResumeAll();
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}
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}
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/*-----------------------------------------------------------*/
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/* A DNS reply was received, see if there is any matching entry and
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call the handler. */
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static void vDNSDoCallback( TickType_t xIdentifier, const char *pcName, uint32_t ulIPAddress );
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static void vDNSDoCallback( TickType_t xIdentifier, const char *pcName, uint32_t ulIPAddress )
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{
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const ListItem_t *pxIterator;
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const MiniListItem_t* xEnd = ( const MiniListItem_t* )listGET_END_MARKER( &xCallbackList );
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vTaskSuspendAll();
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{
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for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd );
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pxIterator != ( const ListItem_t * ) xEnd;
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pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ) )
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{
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if( listGET_LIST_ITEM_VALUE( pxIterator ) == xIdentifier )
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{
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DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator );
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pxCallback->pCallbackFunction( pcName, pxCallback->pvSearchID, ulIPAddress );
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uxListRemove( &pxCallback->xListItem );
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vPortFree( pxCallback );
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if( listLIST_IS_EMPTY( &xCallbackList ) )
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{
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vIPSetDnsTimerEnableState( pdFALSE );
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}
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break;
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}
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}
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}
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xTaskResumeAll();
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}
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#endif /* ipconfigDNS_USE_CALLBACKS != 0 */
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/*-----------------------------------------------------------*/
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#if( ipconfigDNS_USE_CALLBACKS == 0 )
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uint32_t FreeRTOS_gethostbyname( const char *pcHostName )
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#else
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uint32_t FreeRTOS_gethostbyname_a( const char *pcHostName, FOnDNSEvent pCallback, void *pvSearchID, TickType_t xTimeout )
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#endif
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{
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uint32_t ulIPAddress = 0UL;
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TickType_t xReadTimeOut_ms = ipconfigSOCK_DEFAULT_RECEIVE_BLOCK_TIME;
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TickType_t xIdentifier = 0;
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/* If the supplied hostname is IP address, convert it to uint32_t
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and return. */
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#if( ipconfigINCLUDE_FULL_INET_ADDR == 1 )
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{
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ulIPAddress = FreeRTOS_inet_addr( pcHostName );
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}
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#endif /* ipconfigINCLUDE_FULL_INET_ADDR == 1 */
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/* If a DNS cache is used then check the cache before issuing another DNS
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request. */
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#if( ipconfigUSE_DNS_CACHE == 1 )
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{
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if( ulIPAddress == 0UL )
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{
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ulIPAddress = FreeRTOS_dnslookup( pcHostName );
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if( ulIPAddress != 0 )
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{
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FreeRTOS_debug_printf( ( "FreeRTOS_gethostbyname: found '%s' in cache: %lxip\n", pcHostName, ulIPAddress ) );
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}
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else
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{
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/* prvGetHostByName will be called to start a DNS lookup */
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}
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}
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}
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#endif /* ipconfigUSE_DNS_CACHE == 1 */
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/* Generate a unique identifier. */
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if( 0 == ulIPAddress )
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{
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xIdentifier = ( TickType_t )ipconfigRAND32( );
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}
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#if( ipconfigDNS_USE_CALLBACKS != 0 )
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{
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if( pCallback != NULL )
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{
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if( ulIPAddress == 0UL )
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{
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/* The user has provided a callback function, so do not block on recvfrom() */
|
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if( 0 != xIdentifier )
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{
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xReadTimeOut_ms = 0;
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vDNSSetCallBack( pcHostName, pvSearchID, pCallback, xTimeout, ( TickType_t )xIdentifier );
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}
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}
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else
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{
|
|
/* The IP address is known, do the call-back now. */
|
|
pCallback( pcHostName, pvSearchID, ulIPAddress );
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if( ( ulIPAddress == 0UL ) && ( 0 != xIdentifier ) )
|
|
{
|
|
ulIPAddress = prvGetHostByName( pcHostName, xIdentifier, xReadTimeOut_ms );
|
|
}
|
|
|
|
return ulIPAddress;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static uint32_t prvGetHostByName( const char *pcHostName, TickType_t xIdentifier, TickType_t xReadTimeOut_ms )
|
|
{
|
|
struct freertos_sockaddr xAddress;
|
|
Socket_t xDNSSocket;
|
|
uint32_t ulIPAddress = 0UL;
|
|
uint8_t *pucUDPPayloadBuffer;
|
|
uint32_t ulAddressLength = sizeof( struct freertos_sockaddr );
|
|
BaseType_t xAttempt;
|
|
int32_t lBytes;
|
|
size_t xPayloadLength, xExpectedPayloadLength;
|
|
TickType_t xWriteTimeOut_ms = ipconfigSOCK_DEFAULT_SEND_BLOCK_TIME;
|
|
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
BaseType_t bHasDot = pdFALSE;
|
|
#endif /* ipconfigUSE_LLMNR == 1 */
|
|
|
|
/* If LLMNR is being used then determine if the host name includes a '.' -
|
|
if not then LLMNR can be used as the lookup method. */
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
{
|
|
const char *pucPtr;
|
|
for( pucPtr = pcHostName; *pucPtr; pucPtr++ )
|
|
{
|
|
if( *pucPtr == '.' )
|
|
{
|
|
bHasDot = pdTRUE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
#endif /* ipconfigUSE_LLMNR == 1 */
|
|
|
|
/* Two is added at the end for the count of characters in the first
|
|
subdomain part and the string end byte. */
|
|
xExpectedPayloadLength = sizeof( DNSMessage_t ) + strlen( pcHostName ) + sizeof( uint16_t ) + sizeof( uint16_t ) + 2u;
|
|
|
|
xDNSSocket = prvCreateDNSSocket();
|
|
|
|
if( xDNSSocket != NULL )
|
|
{
|
|
FreeRTOS_setsockopt( xDNSSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xWriteTimeOut_ms, sizeof( TickType_t ) );
|
|
FreeRTOS_setsockopt( xDNSSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xReadTimeOut_ms, sizeof( TickType_t ) );
|
|
|
|
for( xAttempt = 0; xAttempt < ipconfigDNS_REQUEST_ATTEMPTS; xAttempt++ )
|
|
{
|
|
/* Get a buffer. This uses a maximum delay, but the delay will be
|
|
capped to ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS so the return value
|
|
still needs to be tested. */
|
|
pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xExpectedPayloadLength, portMAX_DELAY );
|
|
|
|
if( pucUDPPayloadBuffer != NULL )
|
|
{
|
|
/* Create the message in the obtained buffer. */
|
|
xPayloadLength = prvCreateDNSMessage( pucUDPPayloadBuffer, pcHostName, xIdentifier );
|
|
|
|
iptraceSENDING_DNS_REQUEST();
|
|
|
|
/* Obtain the DNS server address. */
|
|
FreeRTOS_GetAddressConfiguration( NULL, NULL, NULL, &ulIPAddress );
|
|
|
|
/* Send the DNS message. */
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
if( bHasDot == pdFALSE )
|
|
{
|
|
/* Use LLMNR addressing. */
|
|
( ( DNSMessage_t * ) pucUDPPayloadBuffer) -> usFlags = 0;
|
|
xAddress.sin_addr = ipLLMNR_IP_ADDR; /* Is in network byte order. */
|
|
xAddress.sin_port = FreeRTOS_ntohs( ipLLMNR_PORT );
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/* Use DNS server. */
|
|
xAddress.sin_addr = ulIPAddress;
|
|
xAddress.sin_port = dnsDNS_PORT;
|
|
}
|
|
|
|
ulIPAddress = 0UL;
|
|
|
|
if( FreeRTOS_sendto( xDNSSocket, pucUDPPayloadBuffer, xPayloadLength, FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) != 0 )
|
|
{
|
|
/* Wait for the reply. */
|
|
lBytes = FreeRTOS_recvfrom( xDNSSocket, &pucUDPPayloadBuffer, 0, FREERTOS_ZERO_COPY, &xAddress, &ulAddressLength );
|
|
|
|
if( lBytes > 0 )
|
|
{
|
|
/* The reply was received. Process it. */
|
|
ulIPAddress = prvParseDNSReply( pucUDPPayloadBuffer, lBytes, xIdentifier );
|
|
|
|
/* Finished with the buffer. The zero copy interface
|
|
is being used, so the buffer must be freed by the
|
|
task. */
|
|
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
|
|
|
|
if( ulIPAddress != 0UL )
|
|
{
|
|
/* All done. */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The message was not sent so the stack will not be
|
|
releasing the zero copy - it must be released here. */
|
|
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Finished with the socket. */
|
|
FreeRTOS_closesocket( xDNSSocket );
|
|
}
|
|
|
|
return ulIPAddress;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, const char *pcHostName, TickType_t xIdentifier )
|
|
{
|
|
DNSMessage_t *pxDNSMessageHeader;
|
|
uint8_t *pucStart, *pucByte;
|
|
DNSTail_t *pxTail;
|
|
static const DNSMessage_t xDefaultPartDNSHeader =
|
|
{
|
|
0, /* The identifier will be overwritten. */
|
|
dnsOUTGOING_FLAGS, /* Flags set for standard query. */
|
|
dnsONE_QUESTION, /* One question is being asked. */
|
|
0, /* No replies are included. */
|
|
0, /* No authorities. */
|
|
0 /* No additional authorities. */
|
|
};
|
|
|
|
/* Copy in the const part of the header. */
|
|
memcpy( ( void * ) pucUDPPayloadBuffer, ( void * ) &xDefaultPartDNSHeader, sizeof( xDefaultPartDNSHeader ) );
|
|
|
|
/* Write in a unique identifier. */
|
|
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
|
|
pxDNSMessageHeader->usIdentifier = ( uint16_t ) xIdentifier;
|
|
|
|
/* Create the resource record at the end of the header. First
|
|
find the end of the header. */
|
|
pucStart = pucUDPPayloadBuffer + sizeof( xDefaultPartDNSHeader );
|
|
|
|
/* Leave a gap for the first length bytes. */
|
|
pucByte = pucStart + 1;
|
|
|
|
/* Copy in the host name. */
|
|
strcpy( ( char * ) pucByte, pcHostName );
|
|
|
|
/* Mark the end of the string. */
|
|
pucByte += strlen( pcHostName );
|
|
*pucByte = 0x00u;
|
|
|
|
/* Walk the string to replace the '.' characters with byte counts.
|
|
pucStart holds the address of the byte count. Walking the string
|
|
starts after the byte count position. */
|
|
pucByte = pucStart;
|
|
|
|
do
|
|
{
|
|
pucByte++;
|
|
|
|
while( ( *pucByte != 0x00 ) && ( *pucByte != '.' ) )
|
|
{
|
|
pucByte++;
|
|
}
|
|
|
|
/* Fill in the byte count, then move the pucStart pointer up to
|
|
the found byte position. */
|
|
*pucStart = ( uint8_t ) ( ( uint32_t ) pucByte - ( uint32_t ) pucStart );
|
|
( *pucStart )--;
|
|
|
|
pucStart = pucByte;
|
|
|
|
} while( *pucByte != 0x00 );
|
|
|
|
/* Finish off the record. */
|
|
|
|
pxTail = (DNSTail_t *)( pucByte + 1 );
|
|
|
|
vSetField16( pxTail, DNSTail_t, usType, dnsTYPE_A_HOST ); /* Type A: host */
|
|
vSetField16( pxTail, DNSTail_t, usClass, dnsCLASS_IN ); /* 1: Class IN */
|
|
|
|
/* Return the total size of the generated message, which is the space from
|
|
the last written byte to the beginning of the buffer. */
|
|
return ( ( uint32_t ) pucByte - ( uint32_t ) pucUDPPayloadBuffer + 1 ) + sizeof( *pxTail );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
|
|
static uint8_t *prvReadNameField( uint8_t *pucByte, size_t xSourceLen, char *pcName, size_t xDestLen )
|
|
{
|
|
size_t xNameLen = 0;
|
|
BaseType_t xCount;
|
|
|
|
if( 0 == xSourceLen )
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/* Determine if the name is the fully coded name, or an offset to the name
|
|
elsewhere in the message. */
|
|
if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET )
|
|
{
|
|
/* Jump over the two byte offset. */
|
|
if( xSourceLen > sizeof( uint16_t ) )
|
|
{
|
|
pucByte += sizeof( uint16_t );
|
|
}
|
|
else
|
|
{
|
|
pucByte = NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* pucByte points to the full name. Walk over the string. */
|
|
while( ( NULL != pucByte ) && ( *pucByte != 0x00 ) && ( xSourceLen > 1 ) )
|
|
{
|
|
/* If this is not the first time through the loop, then add a
|
|
separator in the output. */
|
|
if( ( xNameLen > 0 ) && ( xNameLen < ( xDestLen - 1 ) ) )
|
|
{
|
|
pcName[ xNameLen++ ] = '.';
|
|
}
|
|
|
|
/* Process the first/next sub-string. */
|
|
for( xCount = *(pucByte++), xSourceLen--;
|
|
xCount-- && xSourceLen > 1;
|
|
pucByte++, xSourceLen-- )
|
|
{
|
|
if( xNameLen < xDestLen - 1 )
|
|
{
|
|
pcName[ xNameLen++ ] = *( ( char * )pucByte );
|
|
}
|
|
else
|
|
{
|
|
/* DNS name is too big for the provided buffer. */
|
|
pucByte = NULL;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Confirm that a fully formed name was found. */
|
|
if( NULL != pucByte )
|
|
{
|
|
if( 0x00 == *pucByte )
|
|
{
|
|
pucByte++;
|
|
xSourceLen--;
|
|
pcName[ xNameLen++ ] = '\0';
|
|
}
|
|
else
|
|
{
|
|
pucByte = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
return pucByte;
|
|
}
|
|
#endif /* ipconfigUSE_DNS_CACHE == 1 */
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static uint8_t *prvSkipNameField( uint8_t *pucByte, size_t xSourceLen )
|
|
{
|
|
size_t xChunkLength;
|
|
|
|
if( 0 == xSourceLen )
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/* Determine if the name is the fully coded name, or an offset to the name
|
|
elsewhere in the message. */
|
|
if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET )
|
|
{
|
|
/* Jump over the two byte offset. */
|
|
if( xSourceLen > sizeof( uint16_t ) )
|
|
{
|
|
pucByte += sizeof( uint16_t );
|
|
}
|
|
else
|
|
{
|
|
pucByte = NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* pucByte points to the full name. Walk over the string. */
|
|
while( ( *pucByte != 0x00 ) && ( xSourceLen > 1 ) )
|
|
{
|
|
xChunkLength = *pucByte + 1;
|
|
|
|
if( xSourceLen > xChunkLength )
|
|
{
|
|
xSourceLen -= xChunkLength;
|
|
pucByte += xChunkLength;
|
|
}
|
|
else
|
|
{
|
|
pucByte = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Confirm that a fully formed name was found. */
|
|
if( NULL != pucByte )
|
|
{
|
|
if( 0x00 == *pucByte )
|
|
{
|
|
pucByte++;
|
|
}
|
|
else
|
|
{
|
|
pucByte = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
return pucByte;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
uint32_t ulDNSHandlePacket( NetworkBufferDescriptor_t *pxNetworkBuffer )
|
|
{
|
|
uint8_t *pucUDPPayloadBuffer;
|
|
size_t xPlayloadBufferLength;
|
|
DNSMessage_t *pxDNSMessageHeader;
|
|
|
|
xPlayloadBufferLength = pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t );
|
|
if ( xPlayloadBufferLength < sizeof( DNSMessage_t ) )
|
|
{
|
|
return pdFAIL;
|
|
}
|
|
|
|
pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + sizeof( UDPPacket_t );
|
|
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
|
|
|
|
if( pxNetworkBuffer->xDataLength > sizeof( UDPPacket_t ) )
|
|
{
|
|
prvParseDNSReply( pucUDPPayloadBuffer,
|
|
xPlayloadBufferLength,
|
|
( uint32_t )pxDNSMessageHeader->usIdentifier );
|
|
}
|
|
|
|
/* The packet was not consumed. */
|
|
return pdFAIL;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if( ipconfigUSE_NBNS == 1 )
|
|
|
|
uint32_t ulNBNSHandlePacket (NetworkBufferDescriptor_t *pxNetworkBuffer )
|
|
{
|
|
UDPPacket_t *pxUDPPacket = ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;
|
|
uint8_t *pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + sizeof( UDPPacket_t );
|
|
|
|
if( pxNetworkBuffer->xDataLength > sizeof( UDPPacket_t) )
|
|
{
|
|
prvTreatNBNS( pucUDPPayloadBuffer,
|
|
pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t ),
|
|
pxUDPPacket->xIPHeader.ulSourceIPAddress );
|
|
}
|
|
|
|
/* The packet was not consumed. */
|
|
return pdFAIL;
|
|
}
|
|
|
|
#endif /* ipconfigUSE_NBNS */
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, size_t xBufferLength, TickType_t xIdentifier )
|
|
{
|
|
DNSMessage_t *pxDNSMessageHeader;
|
|
DNSAnswerRecord_t *pxDNSAnswerRecord;
|
|
uint32_t ulIPAddress = 0UL;
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
char *pcRequestedName = NULL;
|
|
#endif
|
|
uint8_t *pucByte;
|
|
size_t xSourceBytesRemaining;
|
|
uint16_t x, usDataLength, usQuestions;
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
uint16_t usType = 0, usClass = 0;
|
|
#endif
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ] = "";
|
|
#endif
|
|
|
|
/* Ensure that the buffer is of at least minimal DNS message length. */
|
|
if( xBufferLength < sizeof( DNSMessage_t ) )
|
|
{
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
else
|
|
{
|
|
xSourceBytesRemaining = xBufferLength;
|
|
}
|
|
|
|
/* Parse the DNS message header. */
|
|
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
|
|
|
|
if( pxDNSMessageHeader->usIdentifier == ( uint16_t ) xIdentifier )
|
|
{
|
|
/* Start at the first byte after the header. */
|
|
pucByte = pucUDPPayloadBuffer + sizeof( DNSMessage_t );
|
|
xSourceBytesRemaining -= sizeof( DNSMessage_t );
|
|
|
|
/* Skip any question records. */
|
|
usQuestions = FreeRTOS_ntohs( pxDNSMessageHeader->usQuestions );
|
|
for( x = 0; x < usQuestions; x++ )
|
|
{
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
{
|
|
if( x == 0 )
|
|
{
|
|
pcRequestedName = ( char * ) pucByte;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
if( x == 0 )
|
|
{
|
|
pucByte = prvReadNameField( pucByte,
|
|
xSourceBytesRemaining,
|
|
pcName,
|
|
sizeof( pcName ) );
|
|
|
|
/* Check for a malformed response. */
|
|
if( NULL == pucByte )
|
|
{
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
else
|
|
{
|
|
xSourceBytesRemaining = ( pucUDPPayloadBuffer + xBufferLength ) - pucByte;
|
|
}
|
|
}
|
|
else
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
{
|
|
/* Skip the variable length pcName field. */
|
|
pucByte = prvSkipNameField( pucByte,
|
|
xSourceBytesRemaining );
|
|
|
|
/* Check for a malformed response. */
|
|
if( NULL == pucByte )
|
|
{
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
else
|
|
{
|
|
xSourceBytesRemaining = pucUDPPayloadBuffer + xBufferLength - pucByte;
|
|
}
|
|
}
|
|
|
|
/* Check the remaining buffer size. */
|
|
if( xSourceBytesRemaining >= sizeof( uint32_t ) )
|
|
{
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
{
|
|
/* usChar2u16 returns value in host endianness */
|
|
usType = usChar2u16( pucByte );
|
|
usClass = usChar2u16( pucByte + 2 );
|
|
}
|
|
#endif /* ipconfigUSE_LLMNR */
|
|
|
|
/* Skip the type and class fields. */
|
|
pucByte += sizeof( uint32_t );
|
|
xSourceBytesRemaining -= sizeof( uint32_t );
|
|
}
|
|
else
|
|
{
|
|
/* Malformed response. */
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
}
|
|
|
|
/* Search through the answer records. */
|
|
pxDNSMessageHeader->usAnswers = FreeRTOS_ntohs( pxDNSMessageHeader->usAnswers );
|
|
|
|
if( ( pxDNSMessageHeader->usFlags & dnsRX_FLAGS_MASK ) == dnsEXPECTED_RX_FLAGS )
|
|
{
|
|
for( x = 0; x < pxDNSMessageHeader->usAnswers; x++ )
|
|
{
|
|
pucByte = prvSkipNameField( pucByte,
|
|
xSourceBytesRemaining );
|
|
|
|
/* Check for a malformed response. */
|
|
if( NULL == pucByte )
|
|
{
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
else
|
|
{
|
|
xSourceBytesRemaining = pucUDPPayloadBuffer + xBufferLength - pucByte;
|
|
}
|
|
|
|
/* Is there enough data for an IPv4 A record answer and, if so,
|
|
is this an A record? */
|
|
if( xSourceBytesRemaining >= sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t ) &&
|
|
usChar2u16( pucByte ) == dnsTYPE_A_HOST )
|
|
{
|
|
/* This is the required record type and is of sufficient size. */
|
|
pxDNSAnswerRecord = ( DNSAnswerRecord_t * )pucByte;
|
|
|
|
/* Sanity check the data length of an IPv4 answer. */
|
|
if( FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength ) == sizeof( uint32_t ) )
|
|
{
|
|
/* Copy the IP address out of the record. */
|
|
memcpy( &ulIPAddress,
|
|
pucByte + sizeof( DNSAnswerRecord_t ),
|
|
sizeof( uint32_t ) );
|
|
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
{
|
|
prvProcessDNSCache( pcName, &ulIPAddress, pxDNSAnswerRecord->ulTTL, pdFALSE );
|
|
}
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
#if( ipconfigDNS_USE_CALLBACKS != 0 )
|
|
{
|
|
/* See if any asynchronous call was made to FreeRTOS_gethostbyname_a() */
|
|
vDNSDoCallback( ( TickType_t ) pxDNSMessageHeader->usIdentifier, pcName, ulIPAddress );
|
|
}
|
|
#endif /* ipconfigDNS_USE_CALLBACKS != 0 */
|
|
}
|
|
|
|
pucByte += sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t );
|
|
xSourceBytesRemaining -= ( sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t ) );
|
|
break;
|
|
}
|
|
else if( xSourceBytesRemaining >= sizeof( DNSAnswerRecord_t ) )
|
|
{
|
|
/* It's not an A record, so skip it. Get the header location
|
|
and then jump over the header. */
|
|
pxDNSAnswerRecord = ( DNSAnswerRecord_t * )pucByte;
|
|
pucByte += sizeof( DNSAnswerRecord_t );
|
|
xSourceBytesRemaining -= sizeof( DNSAnswerRecord_t );
|
|
|
|
/* Determine the length of the answer data from the header. */
|
|
usDataLength = FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength );
|
|
|
|
/* Jump over the answer. */
|
|
if( xSourceBytesRemaining >= usDataLength )
|
|
{
|
|
pucByte += usDataLength;
|
|
xSourceBytesRemaining -= usDataLength;
|
|
}
|
|
else
|
|
{
|
|
/* Malformed response. */
|
|
return dnsPARSE_ERROR;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#if( ipconfigUSE_LLMNR == 1 )
|
|
else if( usQuestions && ( usType == dnsTYPE_A_HOST ) && ( usClass == dnsCLASS_IN ) )
|
|
{
|
|
/* If this is not a reply to our DNS request, it might an LLMNR
|
|
request. */
|
|
if( xApplicationDNSQueryHook ( ( pcRequestedName + 1 ) ) )
|
|
{
|
|
int16_t usLength;
|
|
NetworkBufferDescriptor_t *pxNewBuffer = NULL;
|
|
NetworkBufferDescriptor_t *pxNetworkBuffer = pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
|
|
LLMNRAnswer_t *pxAnswer;
|
|
|
|
if( ( xBufferAllocFixedSize == pdFALSE ) && ( pxNetworkBuffer != NULL ) )
|
|
{
|
|
BaseType_t xDataLength = xBufferLength + sizeof( UDPHeader_t ) + sizeof( EthernetHeader_t ) + sizeof( IPHeader_t );
|
|
|
|
/* The field xDataLength was set to the length of the UDP payload.
|
|
The answer (reply) will be longer than the request, so the packet
|
|
must be duplicaed into a bigger buffer */
|
|
pxNetworkBuffer->xDataLength = xDataLength;
|
|
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, xDataLength + 16 );
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
BaseType_t xOffset1, xOffset2;
|
|
|
|
xOffset1 = ( BaseType_t ) ( pucByte - pucUDPPayloadBuffer );
|
|
xOffset2 = ( BaseType_t ) ( ( ( uint8_t * ) pcRequestedName ) - pucUDPPayloadBuffer );
|
|
|
|
pxNetworkBuffer = pxNewBuffer;
|
|
pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + ipUDP_PAYLOAD_OFFSET_IPv4;
|
|
|
|
pucByte = pucUDPPayloadBuffer + xOffset1;
|
|
pcRequestedName = ( char * ) ( pucUDPPayloadBuffer + xOffset2 );
|
|
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
|
|
|
|
}
|
|
else
|
|
{
|
|
/* Just to indicate that the message may not be answered. */
|
|
pxNetworkBuffer = NULL;
|
|
}
|
|
}
|
|
if( pxNetworkBuffer != NULL )
|
|
{
|
|
pxAnswer = (LLMNRAnswer_t *)pucByte;
|
|
|
|
/* We leave 'usIdentifier' and 'usQuestions' untouched */
|
|
vSetField16( pxDNSMessageHeader, DNSMessage_t, usFlags, dnsLLMNR_FLAGS_IS_REPONSE ); /* Set the response flag */
|
|
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAnswers, 1 ); /* Provide a single answer */
|
|
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAuthorityRRs, 0 ); /* No authority */
|
|
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAdditionalRRs, 0 ); /* No additional info */
|
|
|
|
pxAnswer->ucNameCode = dnsNAME_IS_OFFSET;
|
|
pxAnswer->ucNameOffset = ( uint8_t )( pcRequestedName - ( char * ) pucUDPPayloadBuffer );
|
|
|
|
vSetField16( pxAnswer, LLMNRAnswer_t, usType, dnsTYPE_A_HOST ); /* Type A: host */
|
|
vSetField16( pxAnswer, LLMNRAnswer_t, usClass, dnsCLASS_IN ); /* 1: Class IN */
|
|
vSetField32( pxAnswer, LLMNRAnswer_t, ulTTL, dnsLLMNR_TTL_VALUE );
|
|
vSetField16( pxAnswer, LLMNRAnswer_t, usDataLength, 4 );
|
|
vSetField32( pxAnswer, LLMNRAnswer_t, ulIPAddress, FreeRTOS_ntohl( *ipLOCAL_IP_ADDRESS_POINTER ) );
|
|
|
|
usLength = ( int16_t ) ( sizeof( *pxAnswer ) + ( size_t ) ( pucByte - pucUDPPayloadBuffer ) );
|
|
|
|
prvReplyDNSMessage( pxNetworkBuffer, usLength );
|
|
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
vReleaseNetworkBufferAndDescriptor( pxNewBuffer );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif /* ipconfigUSE_LLMNR == 1 */
|
|
}
|
|
|
|
return ulIPAddress;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if( ipconfigUSE_NBNS == 1 )
|
|
|
|
static void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, size_t xBufferLength, uint32_t ulIPAddress )
|
|
{
|
|
uint16_t usFlags, usType, usClass;
|
|
uint8_t *pucSource, *pucTarget;
|
|
uint8_t ucByte;
|
|
uint8_t ucNBNSName[ 17 ];
|
|
|
|
/* Check for minimum buffer size. */
|
|
if( xBufferLength < sizeof( NBNSRequest_t ) )
|
|
{
|
|
return;
|
|
}
|
|
|
|
/* Read the request flags in host endianness. */
|
|
usFlags = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usFlags ) );
|
|
|
|
if( ( usFlags & dnsNBNS_FLAGS_OPCODE_MASK ) == dnsNBNS_FLAGS_OPCODE_QUERY )
|
|
{
|
|
usType = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usType ) );
|
|
usClass = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usClass ) );
|
|
|
|
/* Not used for now */
|
|
( void )usClass;
|
|
/* For NBNS a name is 16 bytes long, written with capitals only.
|
|
Make sure that the copy is terminated with a zero. */
|
|
pucTarget = ucNBNSName + sizeof(ucNBNSName ) - 2;
|
|
pucTarget[ 1 ] = '\0';
|
|
|
|
/* Start with decoding the last 2 bytes. */
|
|
pucSource = pucUDPPayloadBuffer + ( offsetof( NBNSRequest_t, ucName ) + ( dnsNBNS_ENCODED_NAME_LENGTH - 2 ) );
|
|
|
|
for( ;; )
|
|
{
|
|
ucByte = ( uint8_t ) ( ( ( pucSource[ 0 ] - 0x41 ) << 4 ) | ( pucSource[ 1 ] - 0x41 ) );
|
|
|
|
/* Make sure there are no trailing spaces in the name. */
|
|
if( ( ucByte == ' ' ) && ( pucTarget[ 1 ] == '\0' ) )
|
|
{
|
|
ucByte = '\0';
|
|
}
|
|
|
|
*pucTarget = ucByte;
|
|
|
|
if( pucTarget == ucNBNSName )
|
|
{
|
|
break;
|
|
}
|
|
|
|
pucTarget -= 1;
|
|
pucSource -= 2;
|
|
}
|
|
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
{
|
|
if( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) != 0 )
|
|
{
|
|
/* If this is a response from another device,
|
|
add the name to the DNS cache */
|
|
prvProcessDNSCache( ( char * ) ucNBNSName, &ulIPAddress, 0, pdFALSE );
|
|
}
|
|
}
|
|
#else
|
|
{
|
|
/* Avoid compiler warnings. */
|
|
( void ) ulIPAddress;
|
|
}
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
|
|
if( ( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) == 0 ) &&
|
|
( usType == dnsNBNS_TYPE_NET_BIOS ) &&
|
|
( xApplicationDNSQueryHook( ( const char * ) ucNBNSName ) != pdFALSE ) )
|
|
{
|
|
uint16_t usLength;
|
|
DNSMessage_t *pxMessage;
|
|
NBNSAnswer_t *pxAnswer;
|
|
|
|
/* Someone is looking for a device with ucNBNSName,
|
|
prepare a positive reply. */
|
|
NetworkBufferDescriptor_t *pxNetworkBuffer = pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
|
|
|
|
if( ( xBufferAllocFixedSize == pdFALSE ) && ( pxNetworkBuffer != NULL ) )
|
|
{
|
|
NetworkBufferDescriptor_t *pxNewBuffer;
|
|
BaseType_t xDataLength = pxNetworkBuffer->xDataLength + sizeof( UDPHeader_t ) +
|
|
sizeof( EthernetHeader_t ) + sizeof( IPHeader_t );
|
|
|
|
/* The field xDataLength was set to the length of the UDP payload.
|
|
The answer (reply) will be longer than the request, so the packet
|
|
must be duplicated into a bigger buffer */
|
|
pxNetworkBuffer->xDataLength = xDataLength;
|
|
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, xDataLength + 16 );
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
pucUDPPayloadBuffer = pxNewBuffer->pucEthernetBuffer + sizeof( UDPPacket_t );
|
|
pxNetworkBuffer = pxNewBuffer;
|
|
}
|
|
else
|
|
{
|
|
/* Just prevent that a reply will be sent */
|
|
pxNetworkBuffer = NULL;
|
|
}
|
|
}
|
|
|
|
/* Should not occur: pucUDPPayloadBuffer is part of a xNetworkBufferDescriptor */
|
|
if( pxNetworkBuffer != NULL )
|
|
{
|
|
pxMessage = (DNSMessage_t *)pucUDPPayloadBuffer;
|
|
|
|
/* As the fields in the structures are not word-aligned, we have to
|
|
copy the values byte-by-byte using macro's vSetField16() and vSetField32() */
|
|
vSetField16( pxMessage, DNSMessage_t, usFlags, dnsNBNS_QUERY_RESPONSE_FLAGS ); /* 0x8500 */
|
|
vSetField16( pxMessage, DNSMessage_t, usQuestions, 0 );
|
|
vSetField16( pxMessage, DNSMessage_t, usAnswers, 1 );
|
|
vSetField16( pxMessage, DNSMessage_t, usAuthorityRRs, 0 );
|
|
vSetField16( pxMessage, DNSMessage_t, usAdditionalRRs, 0 );
|
|
|
|
pxAnswer = (NBNSAnswer_t *)( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usType ) );
|
|
|
|
vSetField16( pxAnswer, NBNSAnswer_t, usType, usType ); /* Type */
|
|
vSetField16( pxAnswer, NBNSAnswer_t, usClass, dnsNBNS_CLASS_IN ); /* Class */
|
|
vSetField32( pxAnswer, NBNSAnswer_t, ulTTL, dnsNBNS_TTL_VALUE );
|
|
vSetField16( pxAnswer, NBNSAnswer_t, usDataLength, 6 ); /* 6 bytes including the length field */
|
|
vSetField16( pxAnswer, NBNSAnswer_t, usNbFlags, dnsNBNS_NAME_FLAGS );
|
|
vSetField32( pxAnswer, NBNSAnswer_t, ulIPAddress, FreeRTOS_ntohl( *ipLOCAL_IP_ADDRESS_POINTER ) );
|
|
|
|
usLength = ( uint16_t ) ( offsetof( NBNSRequest_t, usType ) + sizeof( NBNSAnswer_t ) );
|
|
|
|
prvReplyDNSMessage( pxNetworkBuffer, usLength );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif /* ipconfigUSE_NBNS */
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static Socket_t prvCreateDNSSocket( void )
|
|
{
|
|
Socket_t xSocket = NULL;
|
|
struct freertos_sockaddr xAddress;
|
|
BaseType_t xReturn;
|
|
TickType_t xTimeoutTime = pdMS_TO_TICKS( 200 );
|
|
|
|
/* This must be the first time this function has been called. Create
|
|
the socket. */
|
|
xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );
|
|
|
|
/* Auto bind the port. */
|
|
xAddress.sin_port = 0u;
|
|
xReturn = FreeRTOS_bind( xSocket, &xAddress, sizeof( xAddress ) );
|
|
|
|
/* Check the bind was successful, and clean up if not. */
|
|
if( xReturn != 0 )
|
|
{
|
|
FreeRTOS_closesocket( xSocket );
|
|
xSocket = NULL;
|
|
}
|
|
else
|
|
{
|
|
/* Set the send and receive timeouts. */
|
|
FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );
|
|
FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );
|
|
}
|
|
|
|
return xSocket;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) )
|
|
|
|
static void prvReplyDNSMessage( NetworkBufferDescriptor_t *pxNetworkBuffer, BaseType_t lNetLength )
|
|
{
|
|
UDPPacket_t *pxUDPPacket;
|
|
IPHeader_t *pxIPHeader;
|
|
UDPHeader_t *pxUDPHeader;
|
|
|
|
pxUDPPacket = (UDPPacket_t *) pxNetworkBuffer->pucEthernetBuffer;
|
|
pxIPHeader = &pxUDPPacket->xIPHeader;
|
|
pxUDPHeader = &pxUDPPacket->xUDPHeader;
|
|
/* HT: started using defines like 'ipSIZE_OF_xxx' */
|
|
pxIPHeader->usLength = FreeRTOS_htons( lNetLength + ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_UDP_HEADER );
|
|
/* HT:endian: should not be translated, copying from packet to packet */
|
|
pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;
|
|
pxIPHeader->ulSourceIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;
|
|
pxIPHeader->ucTimeToLive = ipconfigUDP_TIME_TO_LIVE;
|
|
pxIPHeader->usIdentification = FreeRTOS_htons( usPacketIdentifier );
|
|
usPacketIdentifier++;
|
|
pxUDPHeader->usLength = FreeRTOS_htons( lNetLength + ipSIZE_OF_UDP_HEADER );
|
|
vFlip_16( pxUDPPacket->xUDPHeader.usSourcePort, pxUDPPacket->xUDPHeader.usDestinationPort );
|
|
|
|
#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
|
|
{
|
|
/* calculate the IP header checksum */
|
|
pxIPHeader->usHeaderChecksum = 0x00;
|
|
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0UL, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
|
|
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
|
|
|
|
/* calculate the UDP checksum for outgoing package */
|
|
usGenerateProtocolChecksum( ( uint8_t* ) pxUDPPacket, lNetLength, pdTRUE );
|
|
}
|
|
#endif
|
|
|
|
/* Important: tell NIC driver how many bytes must be sent */
|
|
pxNetworkBuffer->xDataLength = ( size_t ) ( lNetLength + ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_UDP_HEADER + ipSIZE_OF_ETH_HEADER );
|
|
|
|
/* This function will fill in the eth addresses and send the packet */
|
|
vReturnEthernetFrame( pxNetworkBuffer, pdFALSE );
|
|
}
|
|
|
|
#endif /* ipconfigUSE_NBNS == 1 || ipconfigUSE_LLMNR == 1 */
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if( ipconfigUSE_DNS_CACHE == 1 )
|
|
|
|
static void prvProcessDNSCache( const char *pcName, uint32_t *pulIP, uint32_t ulTTL, BaseType_t xLookUp )
|
|
{
|
|
BaseType_t x;
|
|
BaseType_t xFound = pdFALSE;
|
|
uint32_t ulCurrentTimeSeconds = ( xTaskGetTickCount() / portTICK_PERIOD_MS ) / 1000;
|
|
static BaseType_t xFreeEntry = 0;
|
|
|
|
/* For each entry in the DNS cache table. */
|
|
for( x = 0; x < ipconfigDNS_CACHE_ENTRIES; x++ )
|
|
{
|
|
if( xDNSCache[ x ].pcName[ 0 ] == 0 )
|
|
{
|
|
break;
|
|
}
|
|
|
|
if( 0 == strcmp( xDNSCache[ x ].pcName, pcName ) )
|
|
{
|
|
/* Is this function called for a lookup or to add/update an IP address? */
|
|
if( xLookUp != pdFALSE )
|
|
{
|
|
/* Confirm that the record is still fresh. */
|
|
if( ulCurrentTimeSeconds < ( xDNSCache[ x ].ulTimeWhenAddedInSeconds + FreeRTOS_ntohl( xDNSCache[ x ].ulTTL ) ) )
|
|
{
|
|
*pulIP = xDNSCache[ x ].ulIPAddress;
|
|
}
|
|
else
|
|
{
|
|
/* Age out the old cached record. */
|
|
xDNSCache[ x ].pcName[ 0 ] = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
xDNSCache[ x ].ulIPAddress = *pulIP;
|
|
xDNSCache[ x ].ulTTL = ulTTL;
|
|
xDNSCache[ x ].ulTimeWhenAddedInSeconds = ulCurrentTimeSeconds;
|
|
}
|
|
|
|
xFound = pdTRUE;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if( xFound == pdFALSE )
|
|
{
|
|
if( xLookUp != pdFALSE )
|
|
{
|
|
*pulIP = 0;
|
|
}
|
|
else
|
|
{
|
|
/* Add or update the item. */
|
|
if( strlen( pcName ) < ipconfigDNS_CACHE_NAME_LENGTH )
|
|
{
|
|
strcpy( xDNSCache[ xFreeEntry ].pcName, pcName );
|
|
|
|
xDNSCache[ xFreeEntry ].ulIPAddress = *pulIP;
|
|
xDNSCache[ xFreeEntry ].ulTTL = ulTTL;
|
|
xDNSCache[ xFreeEntry ].ulTimeWhenAddedInSeconds = ulCurrentTimeSeconds;
|
|
|
|
xFreeEntry++;
|
|
if( xFreeEntry == ipconfigDNS_CACHE_ENTRIES )
|
|
{
|
|
xFreeEntry = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if( ( xLookUp == 0 ) || ( *pulIP != 0 ) )
|
|
{
|
|
FreeRTOS_debug_printf( ( "prvProcessDNSCache: %s: '%s' @ %lxip\n", xLookUp ? "look-up" : "add", pcName, FreeRTOS_ntohl( *pulIP ) ) );
|
|
}
|
|
}
|
|
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
|
|
#endif /* ipconfigUSE_DNS != 0 */
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* Provide access to private members for testing. */
|
|
#ifdef AMAZON_FREERTOS_ENABLE_UNIT_TESTS
|
|
#include "aws_freertos_tcp_test_access_dns_define.h"
|
|
#endif
|
|
|