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rewrote sdp_handle_service_search_attribute_request to support minimal buffers
This commit is contained in:
matthias.ringwald
parent
cf19c47a24
commit
cf5c39ed1c
157
src/sdp.c
157
src/sdp.c
@ -439,6 +439,9 @@ static uint16_t sdp_get_size_for_service_search_attribute_response(uint8_t * ser
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int sdp_handle_service_search_attribute_request(uint8_t * packet, uint16_t remote_mtu){
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// SDP header before attribute sevice list: 7
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// Continuation, worst case: 5
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// get request details
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uint16_t transaction_id = READ_NET_16(packet, 1);
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// not used yet - uint16_t param_len = READ_NET_16(packet, 3);
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@ -449,107 +452,85 @@ int sdp_handle_service_search_attribute_request(uint8_t * packet, uint16_t remot
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uint16_t attributeIDListLen = de_get_len(attributeIDList);
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uint8_t * continuationState = &packet[5+serviceSearchPatternLen+2+attributeIDListLen];
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// calc maximumAttributeByteCount based on remote MTU
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uint16_t maximumAttributeByteCount2 = remote_mtu - (7+5);
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// calc maximumAttributeByteCount based on remote MTU, SDP header and reserved Continuation block
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uint16_t maximumAttributeByteCount2 = remote_mtu - 12;
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if (maximumAttributeByteCount2 < maximumAttributeByteCount) {
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maximumAttributeByteCount = maximumAttributeByteCount2;
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}
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// continuation state contains index of next service record to examine
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// continuation state contains the offset into this particular response
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uint16_t continuation_service_index = 0;
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uint16_t continuation_service_index = 0;
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uint16_t continuation_offset = 0;
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int continuation = 0;
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if (continuationState[0] == 4){
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continuation_service_index = READ_NET_16(continuationState, 1);
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continuation_service_index = READ_NET_16(continuationState, 1);
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continuation_offset = READ_NET_16(continuationState, 3);
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}
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// get sum of all service attribute responses on first response
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linked_item_t *it;
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if (continuation_service_index == 0 && continuation_offset == 0){
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uint16_t total_response_size = 3 + sdp_get_size_for_service_search_attribute_response(serviceSearchPattern, attributeIDList);
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log_info("total response size %u, maximumAttributeByteCount %u \n", total_response_size, maximumAttributeByteCount);
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}
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printf("--> sdp_handle_service_search_attribute_request, cont %u/%u, max %u\n", continuation_service_index, continuation_offset, maximumAttributeByteCount);
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// get highest index of matching record - to know when to stop
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int highest_matching_record = -1;
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uint16_t current_service_index = 0;
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// for all service records that match
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for (it = (linked_item_t *) sdp_service_records; it ; it = it->next, ++current_service_index){
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service_record_item_t * item = (service_record_item_t *) it;
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if (sdp_record_matches_service_search_pattern(item->service_record, serviceSearchPattern)){
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highest_matching_record = current_service_index;
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}
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}
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printf("-> sdp_handle_service_search_attribute_request: continuation (%u, %u)\n", continuation_service_index, continuation_offset);
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// AttributeLists - starts at offset 7
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uint16_t pos = 7;
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int complete_response = 0;
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// and create DES header for it
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// header
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sdp_response_buffer[0] = SDP_ServiceSearchAttributeResponse;
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net_store_16(sdp_response_buffer, 1, transaction_id);
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// for all service records that match
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current_service_index = 0;
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for (it = (linked_item_t *) sdp_service_records; it ; it = it->next, ++current_service_index){
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service_record_item_t * item = (service_record_item_t *) it;
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if (current_service_index >= continuation_service_index ) {
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if (sdp_record_matches_service_search_pattern(item->service_record, serviceSearchPattern)){
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// create sequence and copy specified attributes
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uint8_t *attributeList = &sdp_response_buffer[pos];
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de_create_sequence(attributeList);
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sdp_append_attributes_in_attributeIDList(item->service_record, attributeIDList, 0,SDP_RESPONSE_BUFFER_SIZE-7-3, attributeList);
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uint16_t listLen = de_get_len(attributeList);
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// handle continuation
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if (continuation_offset){
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memmove(&sdp_response_buffer[pos], &sdp_response_buffer[pos+continuation_offset], maximumAttributeByteCount);
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listLen -= continuation_offset;
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}
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pos += listLen;
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// complete response from this record?
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if (pos - 7 <= maximumAttributeByteCount){
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continuation_offset = 0;
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current_service_index++;
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if (current_service_index > highest_matching_record) {
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// done
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continuation = 0;
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break;
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} else {
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if (!complete_response){
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continuation = 1;
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break;
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}
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}
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} else {
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continuation_offset += maximumAttributeByteCount;
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if (!continuation_service_index && continuation_offset == maximumAttributeByteCount){
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continuation_offset -= 3; // without initial header
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}
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complete_response = 0;
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continuation = 1;
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break;
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}
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}
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}
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// add DES with total size for first request
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if (continuation_service_index == 0 && continuation_offset == 0){
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uint16_t total_response_size = sdp_get_size_for_service_search_attribute_response(serviceSearchPattern, attributeIDList);
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de_store_descriptor_with_len(&sdp_response_buffer[pos], DE_DES, DE_SIZE_VAR_16, total_response_size);
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log_info("total response size %u\n", total_response_size);
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pos += 3;
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maximumAttributeByteCount -= 3;
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}
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// create attribute list
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int first_answer = 1;
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int continuation = 0;
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uint16_t current_service_index = 0;
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linked_item_t *it = (linked_item_t *) sdp_service_records;
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for ( ; it ; it = it->next, ++current_service_index){
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service_record_item_t * item = (service_record_item_t *) it;
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if (current_service_index < continuation_service_index ) continue;
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if (!sdp_record_matches_service_search_pattern(item->service_record, serviceSearchPattern)) continue;
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// Continuation State
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uint16_t attributeListByteCount = pos - 7;
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if (continuation){
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if (pos > 7 + maximumAttributeByteCount) {
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pos = 7 + maximumAttributeByteCount;
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attributeListByteCount = maximumAttributeByteCount;
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if (continuation_offset == 0){
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// get size of this record
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uint16_t filtered_attributes_size = spd_get_filtered_size(item->service_record, attributeIDList);
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// stop if complete record doesn't fits into response but we already have a partial response
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if ((filtered_attributes_size + 3 > maximumAttributeByteCount) && !first_answer) {
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continuation = 1;
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break;
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}
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// store DES
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de_store_descriptor_with_len(&sdp_response_buffer[pos], DE_DES, DE_SIZE_VAR_16, filtered_attributes_size);
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maximumAttributeByteCount -= 3;
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pos += 3;
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}
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first_answer = 0;
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// copy maximumAttributeByteCount from record
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uint16_t bytes_used;
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int complete = sdp_filter_attributes_in_attributeIDList(item->service_record, attributeIDList, continuation_offset, maximumAttributeByteCount, &bytes_used, &sdp_response_buffer[pos]);
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pos += bytes_used;
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if (complete) {
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continuation_offset = 0;
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continue;
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}
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continuation = 1;
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continuation_offset += bytes_used;
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break;
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}
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uint16_t attributeListsByteCount = pos - 7;
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// Continuation State
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if (continuation){
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sdp_response_buffer[pos++] = 4;
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net_store_16(sdp_response_buffer, pos, (uint16_t) current_service_index);
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pos += 2;
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@ -560,9 +541,11 @@ int sdp_handle_service_search_attribute_request(uint8_t * packet, uint16_t remot
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sdp_response_buffer[pos++] = 0;
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}
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// update header
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// create SDP header
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sdp_response_buffer[0] = SDP_ServiceSearchAttributeResponse;
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net_store_16(sdp_response_buffer, 1, transaction_id);
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net_store_16(sdp_response_buffer, 3, pos - 5); // size of variable payload
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net_store_16(sdp_response_buffer, 5, attributeListByteCount); // AttributeListsByteCount
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net_store_16(sdp_response_buffer, 5, attributeListsByteCount);
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return pos;
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}
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@ -687,7 +670,7 @@ static void dump_service_search_response(void){
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void sdp_test(){
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const uint16_t remote_mtu = 48;
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const uint16_t remote_mtu = 23;
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uint8_t allAttributeIDs[20]; //
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// create an attribute list
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@ -779,7 +762,7 @@ void sdp_test(){
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de_add_number(serviceSearchPattern, DE_UUID, DE_SIZE_16, 0x0001);
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}
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uint16_t serviceSearchPatternLen = de_get_len(serviceSearchPattern);
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net_store_16(request, 5 + serviceSearchPatternLen, 46); // MaximumAttributeByteCount:
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net_store_16(request, 5 + serviceSearchPatternLen, 1000); // MaximumAttributeByteCount:
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uint8_t * attributeIDList = request + 5 + serviceSearchPatternLen + 2;
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de_create_sequence(attributeIDList);
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de_add_number(attributeIDList, DE_UINT, DE_SIZE_32, 0x0000ffff);
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