mirror/btstack
1
0
Fork 0
mirror of https://github.com/bluekitchen/btstack.git synced 2025-01-26 03:35:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

h5: enable Data Integrity Check, validate crc of incoming packets

Browse Source
This commit is contained in:
Matthias Ringwald 2017-02-23 23:41:35 +01:00
parent 91858f1872
commit 79b61987df
1 changed files with 52 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
src/hci_transport_h5.c
View File

@ -69,10 +69,10 @@ typedef enum {
} hci_transport_link_actions_t;
// Configuration Field. No packet buffers -> sliding window = 1, no OOF flow control, no data integrity check
// Configuration Field. No packet buffers -> sliding window = 1, no OOF flow control, support data integrity check
#define LINK_CONFIG_SLIDING_WINDOW_SIZE 1
#define LINK_CONFIG_OOF_FLOW_CONTROL 0
#define LINK_CONFIG_DATA_INTEGRITY_CHECK 0
#define LINK_CONFIG_DATA_INTEGRITY_CHECK 1
#define LINK_CONFIG_VERSION_NR 0
#define LINK_CONFIG_FIELD (LINK_CONFIG_SLIDING_WINDOW_SIZE | (LINK_CONFIG_OOF_FLOW_CONTROL << 3) | (LINK_CONFIG_DATA_INTEGRITY_CHECK << 4) | (LINK_CONFIG_VERSION_NR << 5))
@ -143,6 +143,44 @@ static void hci_transport_link_timeout_handler(btstack_timer_source_t * timer);
static void hci_transport_link_run(void);
static void hci_transport_slip_init(void);
// CRC16-CCITT Calculation - compromise: use 32 byte table - 512 byte table would be faster, but that's too large
static const uint16_t crc16_ccitt_table[] ={
0x0000, 0x1081, 0x2102, 0x3183,
0x4204, 0x5285, 0x6306, 0x7387,
0x8408, 0x9489, 0xa50a, 0xb58b,
0xc60c, 0xd68d, 0xe70e, 0xf78f
};
static uint16_t crc16_ccitt_update (uint16_t crc, uint8_t ch){
crc = (crc >> 4) ^ crc16_ccitt_table[(crc ^ ch) & 0x000f];
crc = (crc >> 4) ^ crc16_ccitt_table[(crc ^ (ch >> 4)) & 0x000f];
return crc;
}
static uint16_t btstack_reverse_bits_16(uint16_t value){
int reverse = 0;
int i;
for (i = 0; i < 16; i++) {
reverse = reverse << 1;
reverse |= value & 1;
value = value >> 1;
}
return reverse;
}
static uint16_t crc16_calc_for_slip_frame(uint8_t * header, uint8_t * payload, uint16_t len){
int i;
uint16_t crc = 0xffff;
for (i=0 ; i < 4 ; i++){
crc = crc16_ccitt_update(crc, header[i]);
}
for (i=0 ; i < len ; i++){
crc = crc16_ccitt_update(crc, payload[i]);
}
return btstack_reverse_bits_16(crc);
}
// -----------------------------
static void hci_transport_inactivity_timeout_handler(btstack_timer_source_t * ts){
log_info("h5: inactivity timeout. link state %d, peer asleep %u, actions 0x%02x, outgoing packet %u",
@ -431,7 +469,7 @@ static void hci_transport_h5_process_frame(uint16_t frame_size){
uint8_t link_packet_type = slip_header[1] & 0x0f;
uint16_t link_payload_len = (slip_header[1] >> 4) | (slip_header[2] << 4);
log_info("hci_transport_h5_process_frame, reliable %u, packet type %u, seq_nr %u, ack_nr %u", reliable_packet, link_packet_type, seq_nr, ack_nr);
log_info("hci_transport_h5_process_frame, reliable %u, packet type %u, seq_nr %u, ack_nr %u , dic %u", reliable_packet, link_packet_type, seq_nr, ack_nr, data_integrity_check_present);
log_info_hexdump(slip_header, 4);
log_info_hexdump(slip_payload, frame_size_without_header);
@ -459,7 +497,15 @@ static void hci_transport_h5_process_frame(uint16_t frame_size){
return;
}
// (TODO data integrity check)
// validate data integrity check
if (data_integrity_check_present){
uint16_t dic_packet = big_endian_read_16(slip_payload, received_payload_len);
uint16_t dic_calculate = crc16_calc_for_slip_frame(slip_header, slip_payload, received_payload_len);
if (dic_packet != dic_calculate){
log_info("h5: expected dic value 0x%04x but got 0x%04x", dic_calculate, dic_packet);
return;
}
}
switch (link_state){
case LINK_UNINITIALIZED:
@ -485,11 +531,11 @@ static void hci_transport_h5_process_frame(uint16_t frame_size){
hci_transport_link_actions |= HCI_TRANSPORT_LINK_SEND_SYNC_RESPONSE;
}
if (memcmp(slip_payload, link_control_config, link_control_config_prefix_len) == 0){
log_info("link: received config");
log_info("link: received config, 0x%02x", slip_payload[2]);
hci_transport_link_actions |= HCI_TRANSPORT_LINK_SEND_CONFIG_RESPONSE;
}
if (memcmp(slip_payload, link_control_config_response, link_control_config_response_prefix_len) == 0){
log_info("link: received config response");
log_info("link: received config response 0x%02x", slip_payload[2]);
link_state = LINK_ACTIVE;
btstack_run_loop_remove_timer(&link_timer);
log_info("link activated");