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/*
* FreeRTOS V202111.00
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* Standard includes. */
#include <assert.h>
#include "http_demo_utils.h"
/* Exponential backoff retry include. */
#include "backoff_algorithm.h"
/* Parser utilities. */
#include "http_parser.h"
/*-----------------------------------------------------------*/
/**
* @brief The maximum number of retries for network operation with server.
*/
#define RETRY_MAX_ATTEMPTS ( 5U )
/**
* @brief The maximum back-off delay (in milliseconds) for retrying failed
* operation with server.
*/
#define RETRY_MAX_BACKOFF_DELAY_MS ( 5000U )
/**
* @brief The base back-off delay (in milliseconds) to use for network operation
* retry attempts.
*/
#define RETRY_BACKOFF_BASE_MS ( 500U )
/*-----------------------------------------------------------*/
/**
* @brief Each compilation unit that consumes the NetworkContext must define it.
* It should contain a single pointer to the type of your desired transport.
* This utility is used by both TLS and plaintext HTTP demos, so define this pointer as void *.
*
* @note Transport stacks are defined in FreeRTOS-Plus/Source/Application-Protocols/network_transport.
*/
struct NetworkContext
{
void * pParams;
};
/*-----------------------------------------------------------*/
extern UBaseType_t uxRand();
/*-----------------------------------------------------------*/
BaseType_t connectToServerWithBackoffRetries( TransportConnect_t connectFunction,
NetworkContext_t * pxNetworkContext )
{
BaseType_t xReturn = pdFAIL;
/* Status returned by the retry utilities. */
BackoffAlgorithmStatus_t xBackoffAlgStatus = BackoffAlgorithmSuccess;
/* Struct containing the next backoff time. */
BackoffAlgorithmContext_t xReconnectParams;
uint16_t usNextBackoff = 0U;
assert( connectFunction != NULL );
/* Initialize reconnect attempts and interval */
BackoffAlgorithm_InitializeParams( &xReconnectParams,
RETRY_BACKOFF_BASE_MS,
RETRY_MAX_BACKOFF_DELAY_MS,
RETRY_MAX_ATTEMPTS );
/* Attempt to connect to the HTTP server. If connection fails, retry after a
* timeout. The timeout value will exponentially increase until either the
* maximum timeout value is reached or the set number of attempts are
* exhausted.*/
do
{
xReturn = connectFunction( pxNetworkContext );
if( xReturn != pdPASS )
{
/* Generate a random number and calculate backoff value (in milliseconds) for
* the next connection retry.
* Note: It is recommended to seed the random number generator with a device-specific
* entropy source so that possibility of multiple devices retrying failed network operations
* at similar intervals can be avoided. */
xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextBackoff );
if( xBackoffAlgStatus == BackoffAlgorithmSuccess )
{
LogWarn( ( "Connection to the HTTP server failed. "
"Retrying connection with backoff and jitter." ) );
LogInfo( ( "Retry attempt %lu out of maximum retry attempts %lu.",
xReconnectParams.attemptsDone,
RETRY_MAX_ATTEMPTS ) );
}
}
} while( ( xReturn == pdFAIL ) && ( xBackoffAlgStatus == BackoffAlgorithmSuccess ) );
if( xReturn == pdFAIL )
{
LogError( ( "Connection to the server failed, all attempts exhausted." ) );
}
return xReturn;
}
/*-----------------------------------------------------------*/
HTTPStatus_t getUrlPath( const char * pcUrl,
size_t xUrlLen,
const char ** pcPath,
size_t * pxPathLen )
{
/* http-parser status. Initialized to 1 to signify failure. */
int lParserStatus = 1;
struct http_parser_url xUrlParser;
HTTPStatus_t xHTTPStatus = HTTPSuccess;
/* Sets all members in xUrlParser to 0. */
http_parser_url_init( &xUrlParser );
if( ( pcUrl == NULL ) || ( pcPath == NULL ) || ( pxPathLen == NULL ) )
{
LogError( ( "NULL parameter passed to getUrlPath()." ) );
xHTTPStatus = HTTPInvalidParameter;
}
if( xHTTPStatus == HTTPSuccess )
{
lParserStatus = http_parser_parse_url( pcUrl, xUrlLen, 0, &xUrlParser );
if( lParserStatus != 0 )
{
LogError( ( "Error parsing the input URL %.*s. Error code: %d.",
( int32_t ) xUrlLen,
pcUrl,
lParserStatus ) );
xHTTPStatus = HTTPParserInternalError;
}
}
if( xHTTPStatus == HTTPSuccess )
{
*pxPathLen = ( size_t ) ( xUrlParser.field_data[ UF_PATH ].len );
if( *pxPathLen == 0 )
{
xHTTPStatus = HTTPNoResponse;
*pcPath = NULL;
}
else
{
*pcPath = &pcUrl[ xUrlParser.field_data[ UF_PATH ].off ];
}
}
if( xHTTPStatus != HTTPSuccess )
{
LogError( ( "Error parsing the path from URL %s. Error code: %d",
pcUrl,
xHTTPStatus ) );
}
return xHTTPStatus;
}
/*-----------------------------------------------------------*/
HTTPStatus_t getUrlAddress( const char * pcUrl,
size_t xUrlLen,
const char ** pcAddress,
size_t * pxAddressLen )
{
/* http-parser status. Initialized to 1 to signify failure. */
int lParserStatus = 1;
struct http_parser_url xUrlParser;
HTTPStatus_t xHTTPStatus = HTTPSuccess;
/* Sets all members in xUrlParser to 0. */
http_parser_url_init( &xUrlParser );
if( ( pcUrl == NULL ) || ( pcAddress == NULL ) || ( pxAddressLen == NULL ) )
{
LogError( ( "NULL parameter passed to getUrlAddress()." ) );
xHTTPStatus = HTTPInvalidParameter;
}
if( xHTTPStatus == HTTPSuccess )
{
lParserStatus = http_parser_parse_url( pcUrl, xUrlLen, 0, &xUrlParser );
if( lParserStatus != 0 )
{
LogError( ( "Error parsing the input URL %.*s. Error code: %d.",
( int32_t ) xUrlLen,
pcUrl,
lParserStatus ) );
xHTTPStatus = HTTPParserInternalError;
}
}
if( xHTTPStatus == HTTPSuccess )
{
*pxAddressLen = ( size_t ) ( xUrlParser.field_data[ UF_HOST ].len );
if( *pxAddressLen == 0 )
{
xHTTPStatus = HTTPNoResponse;
*pcAddress = NULL;
}
else
{
*pcAddress = &pcUrl[ xUrlParser.field_data[ UF_HOST ].off ];
}
}
if( xHTTPStatus != HTTPSuccess )
{
LogError( ( "Error parsing the address from URL %s. Error code %d",
pcUrl,
xHTTPStatus ) );
}
return xHTTPStatus;
}
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