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Diff: lib_NDEF_Handover.cpp
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diff -r 000000000000 -r de13951f30f6 lib_NDEF_Handover.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib_NDEF_Handover.cpp Thu Nov 14 10:34:11 2019 +0000 @@ -0,0 +1,509 @@ +/** + ****************************************************************************** + * @file lib_NDEF_Bluetooth.c + * @author MMY Application Team + * @version $Revision: 2702 $ + * @date $Date: 2016-07-13 18:45:05 +0200 (Wed, 13 Jul 2016) $ + * @brief This file helps to manage a NDEF Handover message. + * @ingroup libNDEF_Handover + ****************************************************************************** + * @attention + * + * <h2><center>© COPYRIGHT 2016 STMicroelectronics</center></h2> + * + * Licensed under ST MYLIBERTY SOFTWARE LICENSE AGREEMENT (the "License"); + * You may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.st.com/myliberty + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, + * AND SPECIFICALLY DISCLAIMING THE IMPLIED WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. + * See the License for the specific language governing permissions and + * limitations under the License. + * + ****************************************************************************** + */ +/* Includes ------------------------------------------------------------------*/ +#include "lib_NDEF_Handover.h" + +/** @addtogroup lib_NDEF_Handover NDEF Handover library + * @ingroup libNDEF + * @brief This module is used to manage the NDEF Handover messages, to negociate the switch to a non-nfc protocol of communication. + * @details + * The NDEF Handover process is described by the NFC Forum Connection Handover specification. + * It consists in a specific NDEF message construct, as: + * - NDEF 1st record: Handover Request or Handover Select record + * - Version + * - Collision Resolution (nested record, optional) + * - Random number + * - Alternative Carrier 1 (nested record) + * - Power state + * - Reference Data + * - Auxiliary Data Reference 1 + * - ... + * - Auxiliary Data Reference N + * - ... + * - Alternative Carrier N (nested record) + * - NDEF record 2+: Alternative Carrier or Auxiliary Data: Connection details for one of the AC (record ID is the AC Reference Data or an Auxiliary Data Reference). + * - ... + * - NDEF record N: Alternative Carrier or Auxiliary Data: Connection details for one of the AC (record ID is the AC Reference Data or an Auxiliary Data Reference). + * _________________ + * @section Handover_Library_Usage NDEF Handover Library usage: + * @subsection Static_Handover Static Handover + * The Static Handover is used when a device is only equipped with a NFC Tag (no peer-to-peer) to directly propose a set of Alternative Carriers (ACs: bluetooth, wifi,...) + * without running the full handover request-select process.\n + * The Handover Select record use in that case is similar to the one used during a regular Handover negociation.\n + * 1. Declare & initialize an instance of `Ndef_Handover_t`, such as: + * + * Ndef_Handover_t wHandover = {.type = NDEF_HANDOVER_SELECT_TYPE, .version = NDEF_HANDOVER_VERSION_1_2}; + * 2. Declare a `sRecordInfo_t` instance: + * + * sRecordInfo_t HandoverRecord; + * 3. Call the `NDEF_CreateHandover` function, to start preparing the Handover Select record + * + * NDEF_CreateHandover(&wHandover,&HandoverRecord); + * 4. Call the `NDEF_AddAlternativeCarrier` for each Alternative Carrier (such as Bluetooth, Wifi, ...) + * 5. Declare and initialize as many `Ndef_Handover_alternative_carrier_t` instances as the number of non-NFC protocol available. + * And then call the `NDEF_AddAlternativeCarrier` for each of them. + * + * Ndef_Handover_alternative_carrier_t wAC_BREDR = {.cps = NDEF_HANDOVER_AC_CPS_ACTIVE, + * .aux_data_ref_count = 0}; + * Ndef_Handover_alternative_carrier_t wAC_BLE = {.cps = NDEF_HANDOVER_AC_CPS_ACTIVE, + * .aux_data_ref_count = 0}; + * Ndef_Handover_alternative_carrier_t wAC_Wifi = {.cps = NDEF_HANDOVER_AC_CPS_ACTIVE, + * .aux_data_ref_count = 0}; + * + * NDEF_AddAlternativeCarrier(&wAC_BREDR,"urn:nfc:handover:bredr", NULL,&HandoverRecord ); + * NDEF_AddAlternativeCarrier(&wAC_BLE,"urn:nfc:handover:ble", NULL,&HandoverRecord ); + * NDEF_AddAlternativeCarrier(&wAC_Wifi,"urn:nfc:handover:wifi", NULL,&HandoverRecord ); + * @note + * 1. In this example a single `Ndef_Handover_alternative_carrier_t` could have been used, as the parameters are the same for all ACs. + * 2. If more than one NDEF record is required to provide the AC connection details, the `aux_data_ref_count` must specify the number of additional records. + * + * Ndef_Handover_alternative_carrier_t wAC_Wifi = {.cps = NDEF_HANDOVER_AC_CPS_ACTIVE, + * .aux_data_ref_count = 2}; + * Then, it's required to initialize an array of pointers to these Auxiliary Data Reference, as: + * + * char *aux_data_ref1 = "urn:nfc:handover:wifi:aux_data_ref1"; + * char *aux_data_ref2 = "urn:nfc:handover:wifi:aux_data_ref2"; + * char *wifi_aux_ref_data_array[2] = {aux_data_ref1,aux_data_ref2}; + * And then provide this array as the 3rd argument to the 'NDEF_AddAlternativeCarrier' function: + * + * NDEF_AddAlternativeCarrier(&wAC_Wifi,"urn:nfc:handover:wifi", wifi_aux_ref_data_array,&HandoverRecord ); + * 6. Call the `NDEF_WriteHandover` function to finalize the NDEF message and write it to the tag. + * + * NDEF_WriteHandover(&HandoverRecord, NDEF_Buffer); + * 7. Then call other functions (from the libNDEF or not) to add records, describing the Alternative Carriers, to the NDEF message: + * + * NDEF_AppendBluetoothOOB ( &w_ble_oob, "urn:nfc:handover:ble" ); + * NDEF_AppendBluetoothOOB ( &w_bredr_oob, "urn:nfc:handover:bredr" ); + * @note + * 1. The ID of these additional records (2nd argument in the above example) must match the Data Reference provided within the Handover record. + * 2. If Auxiliary Data References are expected they must also be added to the NDEF message, with their ID matching the ID provided to the Alternative Carrier record. + * + * @section Reading_Handover Reading through a Handover Request message + * 1. Read the 1st record of the NDEF message: + * + * sRecordInfo_t rRecord; + * NDEF_ReadNDEF(NDEF_Buffer); + * NDEF_IdentifyBuffer(rRecord,NDEF_Buffer); + * 2. Decode the handover: + * + * Ndef_Handover_t rHandover; + * NDEF_ReadHandover(&rRecord , &rHandover ); + * 3. Read all Alternative Carrier records, and their Auxiliary Data References if any. + * + * uint8_t ac_index, aux_index; + * for(ac_index=0;ac_index<rHandover.nb_alternative_carrier;ac_index++) + * { + * Ndef_Handover_alternative_carrier_t rAC; + * NDEF_ReadAC( ac_index, &rHandover , &rAC ); + * for(aux_index = 0; aux_index < rAC.aux_data_ref_count; aux_index++) + * { + * sRecordInfo_t AuxRecord; + * NDEF_ReadAuxData( aux_index, &rAC, &AuxRecord ); + * // Do something with this Auxiliary Data + * } + * // Process this AC (Extract OOB/or whatever data), and decide if this Carrier is supported or not. + * } + * 4. Choose the prefered Carrier and write a Handover Select record with the prefered AC as described in the @ref Static_Handover section. + * @{ + */ + + + +/** + * @brief This function searches the NDEF message to retrieve the nth Auxiliary Data record if present. + * @param aux_data_nb Position of the Auxiliary Data Reference in the Alternative Carrier. + * @param pAC Pointer on the Alternative Carrier structure where to find the Auxiliary Data Reference. + * @param pRecord Pointer to return the output Auxiliary Data record. + * @retval NDEF_OK The Auxiliary Data record has been retrieved. + * @retval NDEF_ERROR Not able to find the Auxiliary Data in the NDEF message. + */ +uint16_t NDEF_ReadAuxData( uint8_t aux_data_nb, Ndef_Handover_alternative_carrier_t *pAC, sRecordInfo_t *pRecord ) +{ + uint16_t status; + uint8_t* pData = pAC->aux_data_ref_start; + uint8_t current_aux = 0; + uint8_t* aux_id; + uint8_t aux_id_length; + + if((pAC->aux_data_ref_start == NULL) || + (pAC->aux_data_ref_end == NULL) || + (pAC->aux_data_ref_count == 0) || + (aux_data_nb >= pAC->aux_data_ref_count)) + return NDEF_ERROR; + + + while((current_aux < aux_data_nb) && (pData < pAC->aux_data_ref_end)) + { + aux_id_length = *pData++; + aux_id = pData; + pData += aux_id_length; + current_aux++; + } + + pData = pAC->aux_data_ref_end; + /* if ac has been found */ + if(current_aux == aux_data_nb) + { + /* let's now look for the corresponding record - must be after the Handover record */ + do { + status = NDEF_IdentifyBuffer(pRecord,pData); + if(status != NDEF_OK) return status; + pData = pAC->ac_record.PayloadBufferAdd; + + if((pRecord->IDLength == aux_id_length) && + !memcmp(pRecord->ID, aux_id,aux_id_length)) + { + /* this is the record we were looking for, so exit */ + return NDEF_OK; + } + + // go to next record + pData = pRecord->PayloadBufferAdd + pRecord->PayloadLength; + + } while (!(pRecord->RecordFlags & MB_Mask)); + + } + // if we go there, it means that the record ID is not found + return NDEF_ERROR; +} + + + +/** + * @brief This function reads the NDEF message and retrieves the nth Alternative Carrier record if present. + * @param ac_nb Position of the Alternative Carrier Reference in the Handover record. + * @param pHandover Pointer to the Handover record where to find the AC Reference Data. + * @param pAC Pointer used to return the output Alternative Carrier record. + * @retval NDEF_OK The Alternative Carrier record has been retrieved. + * @retval NDEF_ERROR Not able to find the Alternative Carrier in the NDEF message. + */ +uint16_t NDEF_ReadAC( uint8_t ac_nb, Ndef_Handover_t *pHandover , Ndef_Handover_alternative_carrier_t *pAC ) +{ + uint16_t status; + uint8_t* pData = pHandover->ac_start; + uint8_t current_ac = 0; + uint8_t* ac_id; + uint8_t ac_id_length; + sRecordInfo_t NestedRecord; + uint8_t ac_found = 0; + + if((pHandover->ac_start == NULL) || + (pHandover->ac_end == NULL) || + (pHandover->nb_alternative_carrier == 0) || + (ac_nb >= pHandover->nb_alternative_carrier)) + return NDEF_ERROR; + + // Default handover init + pAC->aux_data_ref_count = 0; + + while((current_ac <= ac_nb)&&(current_ac <= pHandover->nb_alternative_carrier) && (pData < pHandover->ac_end)) + { + status = NDEF_IdentifyBuffer(&NestedRecord,pData); + if(status != NDEF_OK) return status; + // go to payload address + pData = NestedRecord.PayloadBufferAdd; + + if(!memcmp(NestedRecord.Type,NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR,strlen(NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR))) + { + if(current_ac == ac_nb) + { + // parse the AC now + pAC->cps = pData[0] & NDEF_HANDOVER_AC_CPS_MASK; + ac_id_length = pData[1]; + ac_id = &pData[2]; + pAC->aux_data_ref_count = pData[2 + ac_id_length]; + pAC->aux_data_ref_start = &pData[3 + ac_id_length]; + pAC->aux_data_ref_end = pData + NestedRecord.PayloadLength; + ac_found = 1; + } + current_ac++; + } + // go to next record + pData += NestedRecord.PayloadLength; + } + pData = pHandover->ac_end; + /* if ac has been found */ + if(ac_found) + { + /* let's now look for the corresponding record - must be after the Handover record */ + do { + status = NDEF_IdentifyBuffer(&pAC->ac_record,pData); + if(status != NDEF_OK) return status; + pData = pAC->ac_record.PayloadBufferAdd; + + if((pAC->ac_record.IDLength == ac_id_length) && + !memcmp(pAC->ac_record.ID, ac_id,ac_id_length)) + { + /* this is the record we were looking for, so exit */ + return NDEF_OK; + } + + // go to next record + pData = pAC->ac_record.PayloadBufferAdd + pAC->ac_record.PayloadLength; + // TO DO: add a security condition to avoid infinite loop if NDEF file is corrupted + } while (!(pAC->ac_record.RecordFlags & ME_Mask)); + + } + // if we go there, it means that the record ID is not found + return NDEF_ERROR; +} + + +/** + * @brief This function reads a record and retrieves the Handover information if present. + * @param pRecord Pointer on the record structure to be read. + * @param pHandover Pointer used to return the Handover information. + * @retval NDEF_OK Handover information has been retrieved from the record. + * @retval NDEF_ERROR Not able to read the Handover information from the record. + */ +uint16_t NDEF_ReadHandover(sRecordInfo_t *pRecord , Ndef_Handover_t *pHandover ) +{ + uint16_t status; + uint8_t* pData = pRecord->PayloadBufferAdd; + uint8_t* pEnd = pData + pRecord->PayloadLength; + sRecordInfo_t NestedRecord; + + /* Default Handover Structure init */ + pHandover->version =0; + pHandover->nb_alternative_carrier =0; + pHandover->has_cr = 0; + pHandover->ac_start = NULL; + pHandover->ac_end = NULL; + + /* A Handover record should never be the end of the NDEF message */ + if(pRecord->RecordFlags & ME_Mask) + return NDEF_ERROR; + + if( !memcmp(pRecord->Type,NDEF_HANDOVER_REQUEST_TYPE_STR,strlen(NDEF_HANDOVER_REQUEST_TYPE_STR)) ) + { + pHandover->type = NDEF_HANDOVER_REQUEST_TYPE; + } else if ( !memcmp(pRecord->Type,NDEF_HANDOVER_SELECT_TYPE_STR,strlen(NDEF_HANDOVER_SELECT_TYPE_STR)) ) + { + pHandover->type = NDEF_HANDOVER_SELECT_TYPE; + } else { + /* This is not a Handover record! */ + return NDEF_ERROR; + } + + pHandover->version = *pData++; + + /* Following records are nested into Hr/s record */ + while (pData < pEnd) + { + status = NDEF_IdentifyBuffer(&NestedRecord,pData); + if(status != NDEF_OK) return status; + /* save record address */ + uint8_t* pACRecord = pData; + /* go to payload address */ + pData = NestedRecord.PayloadBufferAdd; + + /* Parse Collision Resolution if Handover request */ + if(pHandover->type == NDEF_HANDOVER_REQUEST_TYPE) + { + + if(!memcmp(NestedRecord.Type,NDEF_HANDOVER_COLLISION_RESOLUTION_TYPE_STR,strlen(NDEF_HANDOVER_COLLISION_RESOLUTION_TYPE_STR))) + { + pHandover->has_cr = 1; + pHandover->cr_random_number = *(uint16_t*)pData; + } + } + + /* Parse AlternativeCarriers just to know how many they are */ + else if(!memcmp(NestedRecord.Type,NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR,strlen(NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR))) + { + pHandover->nb_alternative_carrier++; + if(pHandover->ac_start == NULL) + pHandover->ac_start = pACRecord; + pHandover->ac_end = pData + NestedRecord.PayloadLength; + /* don't parse the AC now */ + } + else { + /* this is an unexpected type, just ignore it */ + } + /* go to next record */ + pData += NestedRecord.PayloadLength; + + } + + return NDEF_OK; +} + +/** + * @brief This function prepares the Handover record with the data given in the Handover structure. + * @param pHandover Pointer on structure containing the handover basic information. + * @param pRecord Pointer used to return the prepared Handover record. + * @retval NDEF_OK The record has been prepared. + * @retval NDEF_ERROR The record has not been prepared. + */ +uint16_t NDEF_CreateHandover(Ndef_Handover_t *pHandover, sRecordInfo_t* pRecord ) +{ + uint16_t status = NDEF_ERROR; + + /* Use a static buffer to prepare the Handover record */ + pRecord->PayloadBufferAdd = NDEF_Record_Buffer; + /* Alternative, where the user must first allocate the Payload buffer in the record: + * if (pRecord->PayloadBufferAdd == NULL) + * return NDEF_ERROR; + */ + + /* Handover MUST be the first record (SR mask to be updated when actually writing the record) */ + pRecord->RecordFlags = MB_Mask | ME_Mask | TNF_WellKnown; + + if(pHandover->type == NDEF_HANDOVER_SELECT_TYPE) + { + pRecord->TypeLength = strlen(NDEF_HANDOVER_SELECT_TYPE_STR); + memcpy(pRecord->Type, NDEF_HANDOVER_SELECT_TYPE_STR,pRecord->TypeLength); + } + else if (pHandover->type == NDEF_HANDOVER_REQUEST_TYPE) + { + pRecord->TypeLength = strlen(NDEF_HANDOVER_SELECT_TYPE_STR); + memcpy(pRecord->Type, NDEF_HANDOVER_REQUEST_TYPE_STR,pRecord->TypeLength); + } + else + return NDEF_ERROR; + + pRecord->PayloadLength = sizeof(pHandover->version); + *pRecord->PayloadBufferAdd = pHandover->version; + + /* Don't write the record for now, additionnal Alternative Carriers to come as nested records. */ + + return status; +} + + +/** + * @brief This function adds an Alternative Carrier record to a Handover record using the data given in the AC structure. + * @param pAC Pointer on input AC structure. + * @param CarrierDataRef String with the Alternative Carrier Data Reference (ID of the corresponding record in the NDEF message). + * @param AuxDataRefID Array with pointers to the Auxiliary Data References (as many as defined in pAC structure). + * @param pRecord Pointer on the Handover record to be filled with the AC data, must have been previously initialized with the NDEF_CreateHandover function. + * @retval NDEF_OK The Handover record has been updated with AC information. + * @retval NDEF_ERROR The Handover record cannot be updated with the AC information. + * @retval NDEF_ERROR_MEMORY_INTERNAL The internal buffer for records is too small to add the AC information. + */ +uint16_t NDEF_AddAlternativeCarrier(Ndef_Handover_alternative_carrier_t *pAC,char *CarrierDataRef, char **AuxDataRefID, sRecordInfo_t* pRecord, I2C* mi2cChannel ) +{ + /* Specific buffer to prepare the Alternative Carrier record */ + uint8_t NDEF_AlternativeCarrier_Buffer[NDEF_AC_BUFFER_SIZE]; + + /* check that there is enough space in the buffers */ + pAC->ac_record.PayloadLength = NDEF_GetACDataLength(pAC,CarrierDataRef,AuxDataRefID); + if(((pRecord->PayloadLength + pAC->ac_record.PayloadLength) > NDEF_RECORD_MAX_SIZE) || + (pAC->ac_record.PayloadLength > NDEF_AC_BUFFER_SIZE)) + return NDEF_ERROR_MEMORY_INTERNAL; + + /* Use specific buffer to prepare the nested record */ + uint8_t *pData = NDEF_AlternativeCarrier_Buffer; + pAC->ac_record.PayloadBufferAdd = pData; + /* Following line is an alternative where the user must allocate the payload buffer of the ac_record: + * uint8_t* pData = pAC->ac_record.PayloadBufferAdd ; + */ + + if ((pRecord->PayloadBufferAdd == NULL) || + (pRecord->PayloadLength == 0)) + return NDEF_ERROR; + + /* AC is not the first record */ + pAC->ac_record.RecordFlags = TNF_WellKnown; + + pAC->ac_record.TypeLength = strlen(NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR); + memcpy(pAC->ac_record.Type, NDEF_HANDOVER_ALTERNATIVE_CARRIER_TYPE_STR,pAC->ac_record.TypeLength); + + /* Length : cps byte + data ref length byte + auxiliary data ref count byte + data ref length */ + *pData++ = pAC->cps & NDEF_HANDOVER_AC_CPS_MASK; + *pData++ = strlen(CarrierDataRef); + memcpy(pData, CarrierDataRef, strlen(CarrierDataRef)); + pData += strlen(CarrierDataRef); + *pData++ = pAC->aux_data_ref_count; + + uint8_t AuxDataIndex; + for(AuxDataIndex = 0;AuxDataIndex<pAC->aux_data_ref_count;AuxDataIndex++) + { + *pData++ = strlen(AuxDataRefID[AuxDataIndex]); + memcpy(pData, AuxDataRefID[AuxDataIndex], strlen(AuxDataRefID[AuxDataIndex])); + pData += strlen(AuxDataRefID[AuxDataIndex]); + } + + /* Append the nested record right after the Handover record - increase its length accordingly */ + pRecord->PayloadLength += NDEF_WriteRecord(&pAC->ac_record,pRecord->PayloadBufferAdd + pRecord->PayloadLength, mi2cChannel); + return NDEF_OK; +} + + +/** + * @brief This function returns the length of an Alternative Carrier record data (excluding the record metadata). + * @param pAC Pointer on the input AC structure. + * @param CarrierDataRef String with the Alternative Carrier Data Reference. + * @param AuxDataRefID Array with the Auxiliary Data References (as many as defined in the pAC structure). + * @return The computed length in bytes corresponding to the provided Alternative Carrier information. + */ +uint32_t NDEF_GetACDataLength(Ndef_Handover_alternative_carrier_t *pAC,char *CarrierDataRef, char **AuxDataRefID) +{ + uint8_t AuxDataIndex; + + /* First compute the Data length */ + uint32_t length = 1 + // cps + 1 + // Carrier data ref length + strlen(CarrierDataRef) + // Carrier data ref + 1 + // auxiliary data count + pAC->aux_data_ref_count * 1; // auxiliary data lengths + + /* Then adds the length of the Auxiliary Data */ + for(AuxDataIndex = 0;AuxDataIndex<pAC->aux_data_ref_count;AuxDataIndex++) + { + length += strlen(AuxDataRefID[AuxDataIndex]); + } + + return length; +} + +/** + * @brief This function writes the Handover record into the memory. + * @param pRecord Pointer on the input Handover record. + * @param pNdef Pointer to a NDEF buffer (used to prepare the data before actual writing to the memory). + * @retval NDEF_OK The memory has been written. + * @retval NDEF_ERROR_MEMORY_INTERNAL Cannot write to tag. + * @retval NDEF_ERROR_NOT_FORMATED CCFile data not supported or not present. + * @retval NDEF_ERROR_MEMORY_TAG Size not compatible with memory. + * @retval NDEF_ERROR_LOCKED Tag locked, cannot be write. + */ +uint16_t NDEF_WriteHandover( sRecordInfo_t* pRecord , uint8_t* pNdef, I2C* mi2cChannel) +{ + /* Note: in case of Handover Select for no matching alternative carrier, the ME bit flag must be set by the caller */ + + uint32_t Size = NDEF_WriteRecord(pRecord,pNdef, mi2cChannel); + return NDEF_WriteNDEF(Size,pNdef, mi2cChannel); +} + +/** + * @} + */ + +/******************* (C) COPYRIGHT 2015 STMicroelectronics *****END OF FILE****/