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btstack/ble/att.c

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/*
* Copyright (C) 2014 BlueKitchen GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* 4. Any redistribution, use, or modification is done solely for
* personal benefit and not for any commercial purpose or for
* monetary gain.
*
* THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
* RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Please inquire about commercial licensing options at
* contact@bluekitchen-gmbh.com
*
*/
#include <stdio.h>
#include <string.h>
#include "att.h"
#include "debug.h"
#include <btstack/utils.h>
// Buetooth Base UUID 00000000-0000-1000-8000-00805F9B34FB in little endian
static const uint8_t bluetooth_base_uuid[] = { 0xfb, 0x34, 0x9b, 0x5f, 0x80, 0x00, 0x00, 0x80, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
static int is_Bluetooth_Base_UUID(uint8_t const *uuid){
if (memcmp(&uuid[0], &bluetooth_base_uuid[0], 12)) return 0;
if (memcmp(&uuid[14], &bluetooth_base_uuid[14], 2)) return 0;
return 1;
}
static uint16_t uuid16_from_uuid(uint16_t uuid_len, uint8_t * uuid){
if (uuid_len == 2) return READ_BT_16(uuid, 0);
if (!is_Bluetooth_Base_UUID(uuid)) return 0;
return READ_BT_16(uuid, 12);
}
// ATT Database
static uint8_t const * att_db = NULL;
static att_read_callback_t att_read_callback = NULL;
static att_write_callback_t att_write_callback = NULL;
static uint8_t att_prepare_write_error_code = 0;
static uint16_t att_prepare_write_error_handle = 0x0000;
// new java-style iterator
typedef struct att_iterator {
// private
uint8_t const * att_ptr;
// public
uint16_t size;
uint16_t flags;
uint16_t handle;
uint8_t const * uuid;
uint16_t value_len;
uint8_t const * value;
} att_iterator_t;
void att_iterator_init(att_iterator_t *it){
it->att_ptr = att_db;
}
int att_iterator_has_next(att_iterator_t *it){
return it->att_ptr != NULL;
}
void att_iterator_fetch_next(att_iterator_t *it){
it->size = READ_BT_16(it->att_ptr, 0);
if (it->size == 0){
it->flags = 0;
it->handle = 0;
it->uuid = NULL;
it->value_len = 0;
it->value = NULL;
it->att_ptr = NULL;
return;
}
it->flags = READ_BT_16(it->att_ptr, 2);
it->handle = READ_BT_16(it->att_ptr, 4);
it->uuid = &it->att_ptr[6];
// handle 128 bit UUIDs
if (it->flags & ATT_PROPERTY_UUID128){
it->value_len = it->size - 22;
it->value = &it->att_ptr[22];
} else {
it->value_len = it->size - 8;
it->value = &it->att_ptr[8];
}
// advance AFTER setting values
it->att_ptr += it->size;
}
int att_iterator_match_uuid16(att_iterator_t *it, uint16_t uuid){
if (it->handle == 0) return 0;
if (it->flags & ATT_PROPERTY_UUID128){
if (!is_Bluetooth_Base_UUID(it->uuid)) return 0;
return READ_BT_16(it->uuid, 12) == uuid;
}
return READ_BT_16(it->uuid, 0) == uuid;
}
int att_iterator_match_uuid(att_iterator_t *it, uint8_t *uuid, uint16_t uuid_len){
if (it->handle == 0) return 0;
// input: UUID16
if (uuid_len == 2) {
return att_iterator_match_uuid16(it, READ_BT_16(uuid, 0));
}
// input and db: UUID128
if (it->flags & ATT_PROPERTY_UUID128){
return memcmp(it->uuid, uuid, 16) == 0;
}
// input: UUID128, db: UUID16
if (!is_Bluetooth_Base_UUID(uuid)) return 0;
return READ_BT_16(uuid, 12) == READ_BT_16(it->uuid, 0);
}
int att_find_handle(att_iterator_t *it, uint16_t handle){
if (handle == 0) return 0;
att_iterator_init(it);
while (att_iterator_has_next(it)){
att_iterator_fetch_next(it);
if (it->handle != handle) continue;
return 1;
}
return 0;
}
// experimental client API
uint16_t att_uuid_for_handle(uint16_t handle){
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok) return 0;
if (it.flags & ATT_PROPERTY_UUID128) return 0;
return READ_BT_16(it.uuid, 0);
}
// end of client API
static void att_update_value_len(att_iterator_t *it, uint16_t con_handle){
if ((it->flags & ATT_PROPERTY_DYNAMIC) == 0 || !att_read_callback) return;
it->value_len = (*att_read_callback)(con_handle, it->handle, 0, NULL, 0);
return;
}
// copy attribute value from offset into buffer with given size
static int att_copy_value(att_iterator_t *it, uint16_t offset, uint8_t * buffer, uint16_t buffer_size, uint16_t con_handle){
// DYNAMIC
if ((it->flags & ATT_PROPERTY_DYNAMIC) && att_read_callback) {
return (*att_read_callback)(con_handle, it->handle, offset, buffer, buffer_size);
}
// STATIC
uint16_t bytes_to_copy = it->value_len - offset;
if (bytes_to_copy > buffer_size){
bytes_to_copy = buffer_size;
}
memcpy(buffer, it->value, bytes_to_copy);
return bytes_to_copy;
}
void att_set_db(uint8_t const * db){
att_db = db;
}
void att_set_read_callback(att_read_callback_t callback){
att_read_callback = callback;
}
void att_set_write_callback(att_write_callback_t callback){
att_write_callback = callback;
}
void att_dump_attributes(void){
att_iterator_t it;
att_iterator_init(&it);
uint8_t uuid128[16];
while (att_iterator_has_next(&it)){
att_iterator_fetch_next(&it);
if (it.handle == 0) {
log_info("Handle: END");
return;
}
log_info("Handle: 0x%04x, flags: 0x%04x, uuid: ", it.handle, it.flags);
if (it.flags & ATT_PROPERTY_UUID128){
swap128(it.uuid, uuid128);
log_info("%s", uuid128_to_str(uuid128));
} else {
log_info("%04x", READ_BT_16(it.uuid, 0));
}
log_info(", value_len: %u, value: ", it.value_len);
hexdump(it.value, it.value_len);
}
}
static void att_prepare_write_reset(void){
att_prepare_write_error_code = 0;
att_prepare_write_error_handle = 0x0000;
}
static void att_prepare_write_update_errors(uint8_t error_code, uint16_t handle){
// first ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LENGTH has highest priority
if (error_code == ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LENGTH && error_code != att_prepare_write_error_code){
att_prepare_write_error_code = error_code;
att_prepare_write_error_handle = handle;
return;
}
// first ATT_ERROR_INVALID_OFFSET is next
if (error_code == ATT_ERROR_INVALID_OFFSET && att_prepare_write_error_code == 0){
att_prepare_write_error_code = error_code;
att_prepare_write_error_handle = handle;
return;
}
}
static uint16_t setup_error(uint8_t * response_buffer, uint16_t request, uint16_t handle, uint8_t error_code){
response_buffer[0] = ATT_ERROR_RESPONSE;
response_buffer[1] = request;
bt_store_16(response_buffer, 2, handle);
response_buffer[4] = error_code;
return 5;
}
static inline uint16_t setup_error_read_not_permitted(uint8_t * response_buffer, uint16_t request, uint16_t start_handle){
return setup_error(response_buffer, request, start_handle, ATT_ERROR_READ_NOT_PERMITTED);
}
static inline uint16_t setup_error_write_not_permitted(uint8_t * response_buffer, uint16_t request, uint16_t start_handle){
return setup_error(response_buffer, request, start_handle, ATT_ERROR_WRITE_NOT_PERMITTED);
}
static inline uint16_t setup_error_atribute_not_found(uint8_t * response_buffer, uint16_t request, uint16_t start_handle){
return setup_error(response_buffer, request, start_handle, ATT_ERROR_ATTRIBUTE_NOT_FOUND);
}
static inline uint16_t setup_error_invalid_handle(uint8_t * response_buffer, uint16_t request, uint16_t handle){
return setup_error(response_buffer, request, handle, ATT_ERROR_INVALID_HANDLE);
}
static inline uint16_t setup_error_invalid_offset(uint8_t * response_buffer, uint16_t request, uint16_t handle){
return setup_error(response_buffer, request, handle, ATT_ERROR_INVALID_OFFSET);
}
static uint8_t att_validate_security(att_connection_t * att_connection, att_iterator_t * it){
int required_encryption_size = it->flags >> 12;
if (required_encryption_size) required_encryption_size++; // store -1 to fit into 4 bit
log_info("att_validate_security. flags 0x%04x - req enc size %u, authorized %u, authenticated %u, encryption_key_size %u",
it->flags, required_encryption_size, att_connection->authorized, att_connection->authenticated, att_connection->encryption_key_size);
if ((it->flags & ATT_PROPERTY_AUTHENTICATION_REQUIRED) && att_connection->authenticated == 0) {
return ATT_ERROR_INSUFFICIENT_AUTHENTICATION;
}
if ((it->flags & ATT_PROPERTY_AUTHORIZATION_REQUIRED) && att_connection->authorized == 0) {
return ATT_ERROR_INSUFFICIENT_AUTHORIZATION;
}
if (required_encryption_size > 0 && att_connection->encryption_key_size == 0){
return ATT_ERROR_INSUFFICIENT_ENCRYPTION;
}
if (required_encryption_size > att_connection->encryption_key_size){
return ATT_ERROR_INSUFFICIENT_ENCRYPTION_KEY_SIZE;
}
return 0;
}
//
// MARK: ATT_EXCHANGE_MTU_REQUEST
//
static uint16_t handle_exchange_mtu_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer){
uint16_t client_rx_mtu = READ_BT_16(request_buffer, 1);
// find min(local max mtu, remote mtu) and use as mtu for this connection
if (client_rx_mtu < att_connection->max_mtu){
att_connection->mtu = client_rx_mtu;
} else {
att_connection->mtu = att_connection->max_mtu;
}
response_buffer[0] = ATT_EXCHANGE_MTU_RESPONSE;
bt_store_16(response_buffer, 1, att_connection->mtu);
return 3;
}
//
// MARK: ATT_FIND_INFORMATION_REQUEST
//
// TODO: handle other types then GATT_PRIMARY_SERVICE_UUID and GATT_SECONDARY_SERVICE_UUID
//
static uint16_t handle_find_information_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size,
uint16_t start_handle, uint16_t end_handle){
log_info("ATT_FIND_INFORMATION_REQUEST: from %04X to %04X", start_handle, end_handle);
uint8_t request_type = ATT_FIND_INFORMATION_REQUEST;
if (start_handle > end_handle || start_handle == 0){
return setup_error_invalid_handle(response_buffer, request_type, start_handle);
}
uint16_t offset = 1;
uint16_t uuid_len = 0;
att_iterator_t it;
att_iterator_init(&it);
while (att_iterator_has_next(&it)){
att_iterator_fetch_next(&it);
if (!it.handle) break;
if (it.handle > end_handle) break;
if (it.handle < start_handle) continue;
// log_info("Handle 0x%04x", it.handle);
uint16_t this_uuid_len = (it.flags & ATT_PROPERTY_UUID128) ? 16 : 2;
// check if value has same len as last one if not first result
if (offset > 1){
if (this_uuid_len != uuid_len) {
break;
}
}
// first
if (offset == 1) {
uuid_len = this_uuid_len;
// set format field
response_buffer[offset] = (it.flags & ATT_PROPERTY_UUID128) ? 0x02 : 0x01;
offset++;
}
// space?
if (offset + 2 + uuid_len > response_buffer_size) break;
// store
bt_store_16(response_buffer, offset, it.handle);
offset += 2;
memcpy(response_buffer + offset, it.uuid, uuid_len);
offset += uuid_len;
}
if (offset == 1){
return setup_error_atribute_not_found(response_buffer, request_type, start_handle);
}
response_buffer[0] = ATT_FIND_INFORMATION_REPLY;
return offset;
}
static uint16_t handle_find_information_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
return handle_find_information_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1), READ_BT_16(request_buffer, 3));
}
//
// MARK: ATT_FIND_BY_TYPE_VALUE
//
// "Only attributes with attribute handles between and including the Starting Handle parameter
// and the Ending Handle parameter that match the requested attri- bute type and the attribute
// value that have sufficient permissions to allow reading will be returned" -> (1)
//
// TODO: handle other types then GATT_PRIMARY_SERVICE_UUID and GATT_SECONDARY_SERVICE_UUID
//
// NOTE: doesn't handle DYNAMIC values
// NOTE: only supports 16 bit UUIDs
//
static uint16_t handle_find_by_type_value_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size,
uint16_t start_handle, uint16_t end_handle,
uint16_t attribute_type, uint16_t attribute_len, uint8_t* attribute_value){
log_info("ATT_FIND_BY_TYPE_VALUE_REQUEST: from %04X to %04X, type %04X, value: ", start_handle, end_handle, attribute_type);
hexdump(attribute_value, attribute_len);
uint8_t request_type = ATT_FIND_BY_TYPE_VALUE_REQUEST;
if (start_handle > end_handle || start_handle == 0){
return setup_error_invalid_handle(response_buffer, request_type, start_handle);
}
uint16_t offset = 1;
uint16_t in_group = 0;
uint16_t prev_handle = 0;
att_iterator_t it;
att_iterator_init(&it);
while (att_iterator_has_next(&it)){
att_iterator_fetch_next(&it);
if (it.handle && it.handle < start_handle) continue;
if (it.handle > end_handle) break; // (1)
// close current tag, if within a group and a new service definition starts or we reach end of att db
if (in_group &&
(it.handle == 0 || att_iterator_match_uuid16(&it, GATT_PRIMARY_SERVICE_UUID) || att_iterator_match_uuid16(&it, GATT_SECONDARY_SERVICE_UUID))){
log_info("End of group, handle 0x%04x", prev_handle);
bt_store_16(response_buffer, offset, prev_handle);
offset += 2;
in_group = 0;
// check if space for another handle pair available
if (offset + 4 > response_buffer_size){
break;
}
}
// keep track of previous handle
prev_handle = it.handle;
// does current attribute match
if (it.handle && att_iterator_match_uuid16(&it, attribute_type) && attribute_len == it.value_len && memcmp(attribute_value, it.value, it.value_len) == 0){
log_info("Begin of group, handle 0x%04x", it.handle);
bt_store_16(response_buffer, offset, it.handle);
offset += 2;
in_group = 1;
}
}
if (offset == 1){
return setup_error_atribute_not_found(response_buffer, request_type, start_handle);
}
response_buffer[0] = ATT_FIND_BY_TYPE_VALUE_RESPONSE;
return offset;
}
static uint16_t handle_find_by_type_value_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
int attribute_len = request_len - 7;
return handle_find_by_type_value_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1),
READ_BT_16(request_buffer, 3), READ_BT_16(request_buffer, 5), attribute_len, &request_buffer[7]);
}
//
// MARK: ATT_READ_BY_TYPE_REQUEST
//
static uint16_t handle_read_by_type_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size,
uint16_t start_handle, uint16_t end_handle,
uint16_t attribute_type_len, uint8_t * attribute_type){
log_info("ATT_READ_BY_TYPE_REQUEST: from %04X to %04X, type: ", start_handle, end_handle);
hexdump(attribute_type, attribute_type_len);
uint8_t request_type = ATT_READ_BY_TYPE_REQUEST;
if (start_handle > end_handle || start_handle == 0){
return setup_error_invalid_handle(response_buffer, request_type, start_handle);
}
uint16_t offset = 1;
uint16_t pair_len = 0;
att_iterator_t it;
att_iterator_init(&it);
uint8_t error_code = 0;
uint16_t first_matching_but_unreadable_handle = 0;
while (att_iterator_has_next(&it)){
att_iterator_fetch_next(&it);
if (!it.handle) break;
if (it.handle < start_handle) continue;
if (it.handle > end_handle) break; // (1)
// does current attribute match
if (!att_iterator_match_uuid(&it, attribute_type, attribute_type_len)) continue;
// skip handles that cannot be read but rembember that there has been at least one
if ((it.flags & ATT_PROPERTY_READ) == 0) {
if (first_matching_but_unreadable_handle == 0) {
first_matching_but_unreadable_handle = it.handle;
}
continue;
}
// check security requirements
error_code = att_validate_security(att_connection, &it);
if (error_code) break;
att_update_value_len(&it, att_connection->con_handle);
// check if value has same len as last one
uint16_t this_pair_len = 2 + it.value_len;
if (offset > 1){
if (pair_len != this_pair_len) {
break;
}
}
// first
if (offset == 1) {
pair_len = this_pair_len;
response_buffer[offset] = pair_len;
offset++;
}
// space?
if (offset + pair_len > response_buffer_size) {
if (offset > 2) break;
it.value_len = response_buffer_size - 4;
response_buffer[1] = 2 + it.value_len;
}
// store
bt_store_16(response_buffer, offset, it.handle);
offset += 2;
uint16_t bytes_copied = att_copy_value(&it, 0, response_buffer + offset, it.value_len, att_connection->con_handle);
offset += bytes_copied;
}
// at least one attribute could be read
if (offset > 1){
response_buffer[0] = ATT_READ_BY_TYPE_RESPONSE;
return offset;
}
// first attribute had an error
if (error_code){
return setup_error(response_buffer, request_type, start_handle, error_code);
}
// no other errors, but all found attributes had been non-readable
if (first_matching_but_unreadable_handle){
return setup_error_read_not_permitted(response_buffer, request_type, first_matching_but_unreadable_handle);
}
// attribute not found
return setup_error_atribute_not_found(response_buffer, request_type, start_handle);
}
static uint16_t handle_read_by_type_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
int attribute_type_len;
if (request_len <= 7){
attribute_type_len = 2;
} else {
attribute_type_len = 16;
}
return handle_read_by_type_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1), READ_BT_16(request_buffer, 3), attribute_type_len, &request_buffer[5]);
}
//
// MARK: ATT_READ_BY_TYPE_REQUEST
//
static uint16_t handle_read_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size, uint16_t handle){
log_info("ATT_READ_REQUEST: handle %04x", handle);
uint8_t request_type = ATT_READ_REQUEST;
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok){
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
// check if handle can be read
if ((it.flags & ATT_PROPERTY_READ) == 0) {
return setup_error_read_not_permitted(response_buffer, request_type, handle);
}
// check security requirements
uint8_t error_code = att_validate_security(att_connection, &it);
if (error_code) {
return setup_error(response_buffer, request_type, handle, error_code);
}
att_update_value_len(&it, att_connection->con_handle);
uint16_t offset = 1;
// limit data
if (offset + it.value_len > response_buffer_size) {
it.value_len = response_buffer_size - 1;
}
// store
uint16_t bytes_copied = att_copy_value(&it, 0, response_buffer + offset, it.value_len, att_connection->con_handle);
offset += bytes_copied;
response_buffer[0] = ATT_READ_RESPONSE;
return offset;
}
static uint16_t handle_read_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
return handle_read_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1));
}
//
// MARK: ATT_READ_BLOB_REQUEST 0x0c
//
static uint16_t handle_read_blob_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size, uint16_t handle, uint16_t value_offset){
log_info("ATT_READ_BLOB_REQUEST: handle %04x, offset %u", handle, value_offset);
uint8_t request_type = ATT_READ_BLOB_REQUEST;
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok){
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
// check if handle can be read
if ((it.flags & ATT_PROPERTY_READ) == 0) {
return setup_error_read_not_permitted(response_buffer, request_type, handle);
}
// check security requirements
uint8_t error_code = att_validate_security(att_connection, &it);
if (error_code) {
return setup_error(response_buffer, request_type, handle, error_code);
}
att_update_value_len(&it, att_connection->con_handle);
if (value_offset > it.value_len){
return setup_error_invalid_offset(response_buffer, request_type, handle);
}
// limit data
uint16_t offset = 1;
if (offset + it.value_len - value_offset > response_buffer_size) {
it.value_len = response_buffer_size - 1 + value_offset;
}
// store
uint16_t bytes_copied = att_copy_value(&it, value_offset, response_buffer + offset, it.value_len - value_offset, att_connection->con_handle);
offset += bytes_copied;
response_buffer[0] = ATT_READ_BLOB_RESPONSE;
return offset;
}
uint16_t handle_read_blob_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
return handle_read_blob_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1), READ_BT_16(request_buffer, 3));
}
//
// MARK: ATT_READ_MULTIPLE_REQUEST 0x0e
//
static uint16_t handle_read_multiple_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size, uint16_t num_handles, uint16_t * handles){
log_info("ATT_READ_MULTIPLE_REQUEST: num handles %u", num_handles);
uint8_t request_type = ATT_READ_MULTIPLE_REQUEST;
// TODO: figure out which error to respond with
// if (num_handles < 2){
// return setup_error(response_buffer, ATT_READ_MULTIPLE_REQUEST, handle, ???);
// }
uint16_t offset = 1;
int i;
uint8_t error_code = 0;
uint16_t handle = 0;
for (i=0;i<num_handles;i++){
handle = handles[i];
if (handle == 0){
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok){
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
// check if handle can be read
if ((it.flags & ATT_PROPERTY_READ) == 0) {
error_code = ATT_ERROR_READ_NOT_PERMITTED;
break;
}
// check security requirements
error_code = att_validate_security(att_connection, &it);
if (error_code) break;
att_update_value_len(&it, att_connection->con_handle);
// limit data
if (offset + it.value_len > response_buffer_size) {
it.value_len = response_buffer_size - 1;
}
// store
uint16_t bytes_copied = att_copy_value(&it, 0, response_buffer + offset, it.value_len, att_connection->con_handle);
offset += bytes_copied;
}
if (error_code){
return setup_error(response_buffer, request_type, handle, error_code);
}
response_buffer[0] = ATT_READ_MULTIPLE_RESPONSE;
return offset;
}
uint16_t handle_read_multiple_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
int num_handles = (request_len - 1) >> 1;
return handle_read_multiple_request2(att_connection, response_buffer, response_buffer_size, num_handles, (uint16_t*) &request_buffer[1]);
}
//
// MARK: ATT_READ_BY_GROUP_TYPE_REQUEST 0x10
//
// Only handles GATT_PRIMARY_SERVICE_UUID and GATT_SECONDARY_SERVICE_UUID
// Core v4.0, vol 3, part g, 2.5.3
// "The «Primary Service» and «Secondary Service» grouping types may be used in the Read By Group Type Request.
// The «Characteristic» grouping type shall not be used in the ATT Read By Group Type Request."
//
// NOTE: doesn't handle DYNAMIC values
//
// NOTE: we don't check for security as PRIMARY and SECONDAY SERVICE definition shouldn't be protected
// Core 4.0, vol 3, part g, 8.1
// "The list of services and characteristics that a device supports is not considered private or
// confidential information, and therefore the Service and Characteristic Discovery procedures
// shall always be permitted. "
//
static uint16_t handle_read_by_group_type_request2(att_connection_t * att_connection, uint8_t * response_buffer, uint16_t response_buffer_size,
uint16_t start_handle, uint16_t end_handle,
uint16_t attribute_type_len, uint8_t * attribute_type){
log_info("ATT_READ_BY_GROUP_TYPE_REQUEST: from %04X to %04X, buffer size %u, type: ", start_handle, end_handle, response_buffer_size);
hexdump(attribute_type, attribute_type_len);
uint8_t request_type = ATT_READ_BY_GROUP_TYPE_REQUEST;
if (start_handle > end_handle || start_handle == 0){
return setup_error_invalid_handle(response_buffer, request_type, start_handle);
}
// assert UUID is primary or secondary service uuid
uint16_t uuid16 = uuid16_from_uuid(attribute_type_len, attribute_type);
if (uuid16 != GATT_PRIMARY_SERVICE_UUID && uuid16 != GATT_SECONDARY_SERVICE_UUID){
return setup_error(response_buffer, request_type, start_handle, ATT_ERROR_UNSUPPORTED_GROUP_TYPE);
}
uint16_t offset = 1;
uint16_t pair_len = 0;
uint16_t in_group = 0;
uint16_t group_start_handle = 0;
uint8_t const * group_start_value = NULL;
uint16_t prev_handle = 0;
att_iterator_t it;
att_iterator_init(&it);
while (att_iterator_has_next(&it)){
att_iterator_fetch_next(&it);
if (it.handle && it.handle < start_handle) continue;
if (it.handle > end_handle) break; // (1)
// log_info("Handle 0x%04x", it.handle);
// close current tag, if within a group and a new service definition starts or we reach end of att db
if (in_group &&
(it.handle == 0 || att_iterator_match_uuid16(&it, GATT_PRIMARY_SERVICE_UUID) || att_iterator_match_uuid16(&it, GATT_SECONDARY_SERVICE_UUID))){
// log_info("End of group, handle 0x%04x, val_len: %u", prev_handle, pair_len - 4);
bt_store_16(response_buffer, offset, group_start_handle);
offset += 2;
bt_store_16(response_buffer, offset, prev_handle);
offset += 2;
memcpy(response_buffer + offset, group_start_value, pair_len - 4);
offset += pair_len - 4;
in_group = 0;
// check if space for another handle pair available
if (offset + pair_len > response_buffer_size){
break;
}
}
// keep track of previous handle
prev_handle = it.handle;
// does current attribute match
// log_info("compare: %04x == %04x", *(uint16_t*) context->attribute_type, *(uint16_t*) uuid);
if (it.handle && att_iterator_match_uuid(&it, attribute_type, attribute_type_len)) {
// check if value has same len as last one
uint16_t this_pair_len = 4 + it.value_len;
if (offset > 1){
if (this_pair_len != pair_len) {
break;
}
}
// log_info("Begin of group, handle 0x%04x", it.handle);
// first
if (offset == 1) {
pair_len = this_pair_len;
response_buffer[offset] = this_pair_len;
offset++;
}
group_start_handle = it.handle;
group_start_value = it.value;
in_group = 1;
}
}
if (offset == 1){
return setup_error_atribute_not_found(response_buffer, request_type, start_handle);
}
response_buffer[0] = ATT_READ_BY_GROUP_TYPE_RESPONSE;
return offset;
}
uint16_t handle_read_by_group_type_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
int attribute_type_len;
if (request_len <= 7){
attribute_type_len = 2;
} else {
attribute_type_len = 16;
}
return handle_read_by_group_type_request2(att_connection, response_buffer, response_buffer_size, READ_BT_16(request_buffer, 1), READ_BT_16(request_buffer, 3), attribute_type_len, &request_buffer[5]);
}
//
// MARK: ATT_WRITE_REQUEST 0x12
static uint16_t handle_write_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
uint8_t request_type = ATT_WRITE_REQUEST;
uint16_t handle = READ_BT_16(request_buffer, 1);
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok) {
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
if (!att_write_callback) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
if ((it.flags & ATT_PROPERTY_WRITE) == 0) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
if ((it.flags & ATT_PROPERTY_DYNAMIC) == 0) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
// check security requirements
uint8_t error_code = att_validate_security(att_connection, &it);
if (error_code) {
return setup_error(response_buffer, request_type, handle, error_code);
}
error_code = (*att_write_callback)(att_connection->con_handle, handle, ATT_TRANSACTION_MODE_NONE, 0, request_buffer + 3, request_len - 3);
if (error_code) {
return setup_error(response_buffer, request_type, handle, error_code);
}
response_buffer[0] = ATT_WRITE_RESPONSE;
return 1;
}
//
// MARK: ATT_PREPARE_WRITE_REQUEST 0x16
static uint16_t handle_prepare_write_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
uint8_t request_type = ATT_PREPARE_WRITE_REQUEST;
uint16_t handle = READ_BT_16(request_buffer, 1);
uint16_t offset = READ_BT_16(request_buffer, 3);
if (!att_write_callback) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok) {
return setup_error_invalid_handle(response_buffer, request_type, handle);
}
if ((it.flags & ATT_PROPERTY_WRITE) == 0) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
if ((it.flags & ATT_PROPERTY_DYNAMIC) == 0) {
return setup_error_write_not_permitted(response_buffer, request_type, handle);
}
// check security requirements
uint8_t error_code = att_validate_security(att_connection, &it);
if (error_code) {
return setup_error(response_buffer, request_type, handle, error_code);
}
error_code = (*att_write_callback)(att_connection->con_handle, handle, ATT_TRANSACTION_MODE_ACTIVE, offset, request_buffer + 5, request_len - 5);
switch (error_code){
case 0:
break;
case ATT_ERROR_INVALID_OFFSET:
case ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LENGTH:
// postpone to execute write request
att_prepare_write_update_errors(error_code, handle);
break;
default:
return setup_error(response_buffer, request_type, handle, error_code);
}
// response: echo request
memcpy(response_buffer, request_buffer, request_len);
response_buffer[0] = ATT_PREPARE_WRITE_RESPONSE;
return request_len;
}
/*
* @brief transcation queue of prepared writes, e.g., after disconnect
*/
void att_clear_transaction_queue(att_connection_t * att_connection){
if (!att_write_callback) return;
(*att_write_callback)(att_connection->con_handle, 0, ATT_TRANSACTION_MODE_CANCEL, 0, NULL, 0);
}
// MARK: ATT_EXECUTE_WRITE_REQUEST 0x18
// NOTE: security has been verified by handle_prepare_write_request
static uint16_t handle_execute_write_request(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
uint8_t request_type = ATT_EXECUTE_WRITE_REQUEST;
if (!att_write_callback) {
return setup_error_write_not_permitted(response_buffer, request_type, 0);
}
if (request_buffer[1]) {
// deliver queued errors
if (att_prepare_write_error_code){
att_clear_transaction_queue(att_connection);
uint8_t error_code = att_prepare_write_error_code;
uint16_t handle = att_prepare_write_error_handle;
att_prepare_write_reset();
return setup_error(response_buffer, request_type, handle, error_code);
}
(*att_write_callback)(att_connection->con_handle, 0, ATT_TRANSACTION_MODE_EXECUTE, 0, NULL, 0);
} else {
att_clear_transaction_queue(att_connection);
}
response_buffer[0] = ATT_EXECUTE_WRITE_RESPONSE;
return 1;
}
// MARK: ATT_WRITE_COMMAND 0x52
// Core 4.0, vol 3, part F, 3.4.5.3
// "No Error Response or Write Response shall be sent in response to this command"
static void handle_write_command(att_connection_t * att_connection, uint8_t * request_buffer, uint16_t request_len,
uint8_t * response_buffer, uint16_t response_buffer_size){
if (!att_write_callback) return;
uint16_t handle = READ_BT_16(request_buffer, 1);
att_iterator_t it;
int ok = att_find_handle(&it, handle);
if (!ok) return;
if ((it.flags & ATT_PROPERTY_DYNAMIC) == 0) return;
if ((it.flags & ATT_PROPERTY_WRITE_WITHOUT_RESPONSE) == 0) return;
if (att_validate_security(att_connection, &it)) return;
(*att_write_callback)(att_connection->con_handle, handle, ATT_TRANSACTION_MODE_NONE, 0, request_buffer + 3, request_len - 3);
}
// MARK: helper for ATT_HANDLE_VALUE_NOTIFICATION and ATT_HANDLE_VALUE_INDICATION
static uint16_t prepare_handle_value(att_connection_t * att_connection,
uint16_t handle,
uint8_t *value,
uint16_t value_len,
uint8_t * response_buffer){
bt_store_16(response_buffer, 1, handle);
if (value_len > att_connection->mtu - 3){
value_len = att_connection->mtu - 3;
}
memcpy(&response_buffer[3], value, value_len);
return value_len + 3;
}
// MARK: ATT_HANDLE_VALUE_NOTIFICATION 0x1b
uint16_t att_prepare_handle_value_notification(att_connection_t * att_connection,
uint16_t handle,
uint8_t *value,
uint16_t value_len,
uint8_t * response_buffer){
response_buffer[0] = ATT_HANDLE_VALUE_NOTIFICATION;
return prepare_handle_value(att_connection, handle, value, value_len, response_buffer);
}
// MARK: ATT_HANDLE_VALUE_INDICATION 0x1d
uint16_t att_prepare_handle_value_indication(att_connection_t * att_connection,
uint16_t handle,
uint8_t *value,
uint16_t value_len,
uint8_t * response_buffer){
response_buffer[0] = ATT_HANDLE_VALUE_INDICATION;
return prepare_handle_value(att_connection, handle, value, value_len, response_buffer);
}
// MARK: Dispatcher
uint16_t att_handle_request(att_connection_t * att_connection,
uint8_t * request_buffer,
uint16_t request_len,
uint8_t * response_buffer){
uint16_t response_len = 0;
uint16_t response_buffer_size = att_connection->mtu;
switch (request_buffer[0]){
case ATT_EXCHANGE_MTU_REQUEST:
response_len = handle_exchange_mtu_request(att_connection, request_buffer, request_len, response_buffer);
break;
case ATT_FIND_INFORMATION_REQUEST:
response_len = handle_find_information_request(att_connection, request_buffer, request_len,response_buffer, response_buffer_size);
break;
case ATT_FIND_BY_TYPE_VALUE_REQUEST:
response_len = handle_find_by_type_value_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_READ_BY_TYPE_REQUEST:
response_len = handle_read_by_type_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_READ_REQUEST:
response_len = handle_read_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_READ_BLOB_REQUEST:
response_len = handle_read_blob_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_READ_MULTIPLE_REQUEST:
response_len = handle_read_multiple_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_READ_BY_GROUP_TYPE_REQUEST:
response_len = handle_read_by_group_type_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_WRITE_REQUEST:
response_len = handle_write_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_PREPARE_WRITE_REQUEST:
response_len = handle_prepare_write_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_EXECUTE_WRITE_REQUEST:
response_len = handle_execute_write_request(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_WRITE_COMMAND:
handle_write_command(att_connection, request_buffer, request_len, response_buffer, response_buffer_size);
break;
case ATT_SIGNED_WRITE_COMMAND:
log_info("handle_signed_write_command preprocessed by att_server.c");
break;
default:
log_info("Unhandled ATT Command: %02X, DATA: ", request_buffer[0]);
hexdump(&request_buffer[9], request_len-9);
break;
}
return response_len;
}
#if 0
// test profile
#include "profile.h"
int main(void){
int acl_buffer_size;
uint8_t acl_buffer[27];
att_set_db(profile_data);
att_dump_attributes();
uint8_t uuid_1[] = { 0x00, 0x18};
acl_buffer_size = handle_find_by_type_value_request2(acl_buffer, 19, 0, 0xffff, 0x2800, 2, (uint8_t *) &uuid_1);
hexdump(acl_buffer, acl_buffer_size);
uint8_t uuid_3[] = { 0x00, 0x2a};
acl_buffer_size = handle_read_by_type_request2(acl_buffer, 19, 0, 0xffff, 2, (uint8_t *) &uuid_3);
hexdump(acl_buffer, acl_buffer_size);
acl_buffer_size = handle_find_by_type_value_request2(acl_buffer, 19, 0, 0xffff, 0x2800, 2, (uint8_t *) &uuid_1);
hexdump(acl_buffer, acl_buffer_size);
uint8_t uuid_4[] = { 0x00, 0x28};
acl_buffer_size = handle_read_by_group_type_request2(acl_buffer, 20, 0, 0xffff, 2, (uint8_t *) &uuid_4);
hexdump(acl_buffer, acl_buffer_size);
acl_buffer_size = handle_find_information_request2(acl_buffer, 20, 0, 0xffff);
hexdump(acl_buffer, acl_buffer_size);
acl_buffer_size = handle_find_information_request2(acl_buffer, 20, 3, 0xffff);
hexdump(acl_buffer, acl_buffer_size);
acl_buffer_size = handle_find_information_request2(acl_buffer, 20, 5, 0xffff);
hexdump(acl_buffer, acl_buffer_size);
acl_buffer_size = handle_read_request2(acl_buffer, 19, 0x0003);
hexdump(acl_buffer, acl_buffer_size);
return 0;
}
#endif
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