mirror/btstack
1
0
Fork 0
mirror of https://github.com/bluekitchen/btstack.git synced 2025-01-27 06:35:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

l2cap-ertm: store out of sequence SDUs, process in order after missing packet is received

Browse Source
This commit is contained in:
Matthias Ringwald 2017-07-24 15:05:57 +02:00
parent e32be4094e
commit 707347078f
2 changed files with 43 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
src/l2cap.c
View File

@ -2624,6 +2624,29 @@ static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t
#endif
#ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE
// @param delta number of frames in the future, >= 1
static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, uint8_t * payload, uint16_t size){
log_info("Store SDU with delta %u", delta);
// get rx state for packet to store
int index = l2cap_channel->rx_store_index + delta - 1;
if (index > l2cap_channel->num_rx_buffers){
index -= l2cap_channel->num_rx_buffers;
}
log_info("Index of packet to store %u", index);
l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index];
// check if buffer is free
if (rx_state->valid){
log_error("Packet buffer already used");
return;
}
rx_state->valid = 1;
rx_state->sar = sar;
rx_state->len = size;
uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index];
memcpy(rx_buffer, payload, size);
}
static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, uint8_t * payload, uint16_t size){
switch (sar){
case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU:
@ -2806,9 +2829,26 @@ static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *pa
// process SDU
l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2));
// process stored segments
while (1){
int index = l2cap_channel->rx_store_index;
l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index];
if (!rx_state->valid) break;
rx_state->valid = 0;
l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len);
index++;
if (index >= l2cap_channel->num_rx_buffers){
index = 0;
}
l2cap_channel->rx_store_index = index;
}
} else {
int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f;
if (delta < 2){
// store segment
l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2));
log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq);
l2cap_channel->send_supervisor_frame_selective_reject = 1;
} else {

4
src/l2cap.h
View File

@ -118,7 +118,6 @@ typedef enum {
typedef struct {
l2cap_segmentation_and_reassembly_t sar;
uint16_t len;
uint8_t tx_seq;
uint8_t valid;
} l2cap_ertm_rx_packet_state_t;
@ -268,6 +267,9 @@ typedef struct {
// local mps = size of rx/tx packets
uint16_t local_mps;
// receiver: buffer index of to store packet with delta = 1
uint8_t rx_store_index;
// receiver - reassemly
uint16_t reassembly_pos;