fix RLC UM issue with very large MAC grants

master
Andre Puschmann 6 years ago
parent 1ba9c4adc1
commit a6d9181881

@ -39,6 +39,8 @@
namespace srslte {
#define RLC_UM_MAX_SDU_SIZE (2048-1) // Length of LI field is 11bits
struct rlc_umd_pdu_t{
rlc_umd_pdu_header_t header;
byte_buffer_t *buf;
@ -146,6 +148,7 @@ private:
bool configure(srslte_rlc_config_t cfg, std::string rb_name);
void handle_data_pdu(uint8_t *payload, uint32_t nof_bytes);
void reassemble_rx_sdus();
bool pdu_belongs_to_rx_sdu();
bool inside_reordering_window(uint16_t sn);
uint32_t get_num_rx_bytes();
void reset_metrics();
@ -213,6 +216,7 @@ private:
uint32_t lcid;
srslte_rlc_um_config_t cfg;
std::string rb_name;
byte_buffer_pool *pool;
std::string get_rb_name(srsue::rrc_interface_rlc *rrc, uint32_t lcid, bool is_mrb);
};

@ -37,6 +37,7 @@ namespace srslte {
rlc_um::rlc_um(uint32_t queue_len)
:lcid(0)
,tx(queue_len)
,pool(byte_buffer_pool::get_instance())
,rrc(NULL)
,log(NULL)
{
@ -150,6 +151,11 @@ uint32_t rlc_um::get_bearer()
***************************************************************************/
void rlc_um::write_sdu(byte_buffer_t *sdu, bool blocking)
{
if (sdu->N_bytes > RLC_UM_MAX_SDU_SIZE) {
log->warning("Dropping too long SDU of size %d B (Max. size %d B).", sdu->N_bytes, RLC_UM_MAX_SDU_SIZE);
pool->deallocate(sdu);
}
if (blocking) {
tx.write_sdu(sdu);
} else {
@ -399,7 +405,7 @@ int rlc_um::rlc_um_tx::build_data_pdu(uint8_t *payload, uint32_t nof_bytes)
uint8_t *pdu_ptr = pdu->msg;
int head_len = rlc_um_packed_length(&header);
int pdu_space = nof_bytes;
int pdu_space = SRSLTE_MIN(nof_bytes, pdu->get_tailroom());;
if(pdu_space <= head_len + 1)
{
@ -430,7 +436,7 @@ int rlc_um::rlc_um_tx::build_data_pdu(uint8_t *payload, uint32_t nof_bytes)
pool->deallocate(tx_sdu);
tx_sdu = NULL;
}
pdu_space -= to_move;
pdu_space -= SRSLTE_MIN(to_move, pdu->get_tailroom());
header.fi |= RLC_FI_FIELD_NOT_START_ALIGNED; // First byte does not correspond to first byte of SDU
}
@ -474,7 +480,7 @@ int rlc_um::rlc_um_tx::build_data_pdu(uint8_t *payload, uint32_t nof_bytes)
memcpy(payload, pdu->msg, pdu->N_bytes);
uint32_t ret = pdu->N_bytes;
log->info("%s Transmitting PDU SN=%d (%d B)\n", get_rb_name(), header.sn, pdu->N_bytes);
log->info("%s Tx PDU SN=%d (%d B)\n", get_rb_name(), header.sn, pdu->N_bytes);
pool->deallocate(pdu);
debug_state();
@ -595,7 +601,7 @@ void rlc_um::rlc_um_rx::handle_data_pdu(uint8_t *payload, uint32_t nof_bytes)
rlc_um_read_data_pdu_header(payload, nof_bytes, cfg.rx_sn_field_length, &header);
log->info_hex(payload, nof_bytes, "RX %s Rx data PDU SN: %d", get_rb_name(), header.sn);
log->info_hex(payload, nof_bytes, "RX %s Rx data PDU SN: %d (%d B)", get_rb_name(), header.sn, nof_bytes);
if(RX_MOD_BASE(header.sn) >= RX_MOD_BASE(vr_uh-cfg.rx_window_size) &&
RX_MOD_BASE(header.sn) < RX_MOD_BASE(vr_ur))
@ -758,35 +764,29 @@ void rlc_um::rlc_um_rx::reassemble_rx_sdus()
// Now update vr_ur until we reach an SN we haven't yet received
while(rx_window.end() != rx_window.find(vr_ur)) {
log->debug("Reassemble loop for vr_ur=%d\n", vr_ur);
if ((vr_ur_in_rx_sdu+1)%cfg.rx_mod != vr_ur) {
log->warning("PDU SN=%d lost, dropping remainder of %d\n", vr_ur_in_rx_sdu+1, vr_ur);
if (not pdu_belongs_to_rx_sdu()) {
log->warning("PDU SN=%d lost, stop reassambling SDU (vr_ur_in_rx_sdu=%d)\n", vr_ur_in_rx_sdu+1, vr_ur_in_rx_sdu);
pdu_lost = false; // Reset flag to not prevent reassembling of further segments
rx_sdu->reset();
}
// Handle any SDU segments
for(uint32_t i=0; i<rx_window[vr_ur].header.N_li; i++) {
int len = rx_window[vr_ur].header.li[i];
log->debug("Handling SDU egment i=%d with len=%d of vr_ur=%d N_li=%d [%s]\n", i, len, vr_ur, rx_window[vr_ur].header.N_li, rlc_fi_field_text[rx_window[vr_ur].header.fi]);
// Check if the first part of the PDU is a middle or end segment
if (rx_sdu->N_bytes == 0 && i == 0 && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
log->warning_hex(rx_window[vr_ur].buf->msg, len, "Dropping first part of SN %d due to lost start segment\n", vr_ur);
log->warning_hex(rx_window[vr_ur].buf->msg, len, "Dropping first %d B of SN %d due to lost start segment\n", len, vr_ur);
// Advance data pointers and continue with next segment
rx_window[vr_ur].buf->msg += len;
rx_window[vr_ur].buf->N_bytes -= len;
rx_sdu->reset();
// beginning of next SDU?
if (rx_window[vr_ur].header.fi == RLC_FI_FIELD_NOT_START_OR_END_ALIGNED) {
len = rx_window[vr_ur].buf->N_bytes;
log->info_hex(rx_window[vr_ur].buf->msg, len, "Copying first %d bytes of new SDU\n", len);
memcpy(rx_sdu->msg, rx_window[vr_ur].buf->msg, len);
rx_sdu->N_bytes = len;
rx_window[vr_ur].buf->msg += len;
rx_window[vr_ur].buf->N_bytes -= len;
log->info("Updating vr_ur_in_rx_sdu. old=%d, new=%d\n", vr_ur_in_rx_sdu, vr_ur);
vr_ur_in_rx_sdu = vr_ur;
goto clean_up_rx_window;
}
// Reset flag, it is safe to process all remaining segments of this PDU
pdu_lost = false;
continue;
}
// Check available space in SDU
@ -796,16 +796,22 @@ void rlc_um::rlc_um_rx::reassemble_rx_sdus()
goto clean_up_rx_window;
}
log->info_hex(rx_window[vr_ur].buf->msg, len, "Concatenating %d bytes in to current length %d. rx_window remaining bytes=%d, vr_ur_in_rx_sdu=%d, vr_ur=%d, rx_mod=%d, last_mod=%d\n",
len, rx_sdu->N_bytes, rx_window[vr_ur].buf->N_bytes, vr_ur_in_rx_sdu, vr_ur, cfg.rx_mod, (vr_ur_in_rx_sdu+1)%cfg.rx_mod);
if (not pdu_belongs_to_rx_sdu()) {
log->info_hex(rx_window[vr_ur].buf->msg, len, "Copying first %d bytes of new SDU\n", len);
log->info("Updating vr_ur_in_rx_sdu. old=%d, new=%d\n", vr_ur_in_rx_sdu, vr_ur);
vr_ur_in_rx_sdu = vr_ur;
} else {
log->info_hex(rx_window[vr_ur].buf->msg, len, "Concatenating %d bytes in to current length %d. rx_window remaining bytes=%d, vr_ur_in_rx_sdu=%d, vr_ur=%d, rx_mod=%d, last_mod=%d\n",
len, rx_sdu->N_bytes, rx_window[vr_ur].buf->N_bytes, vr_ur_in_rx_sdu, vr_ur, cfg.rx_mod, (vr_ur_in_rx_sdu+1)%cfg.rx_mod);
}
memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, len);
rx_sdu->N_bytes += len;
rx_window[vr_ur].buf->msg += len;
rx_window[vr_ur].buf->N_bytes -= len;
if((pdu_lost && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) || (vr_ur != ((vr_ur_in_rx_sdu+1)%cfg.rx_mod))) {
log->warning("Dropping remainder of lost PDU (update vr_ur middle segments, vr_ur=%d, vr_ur_in_rx_sdu=%d)\n", vr_ur, vr_ur_in_rx_sdu);
rx_sdu->reset();
} else {
vr_ur_in_rx_sdu = vr_ur;
if (not pdu_lost && pdu_belongs_to_rx_sdu()) {
log->info_hex(rx_sdu->msg, rx_sdu->N_bytes, "%s Rx SDU vr_ur=%d, i=%d, (update vr_ur middle segments)", get_rb_name(), vr_ur, i);
rx_sdu->set_timestamp();
if(cfg.is_mrb){
@ -818,6 +824,11 @@ void rlc_um::rlc_um_rx::reassemble_rx_sdus()
log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
return;
}
} else {
log->warning("Dropping remainder of lost PDU (update vr_ur middle segments, vr_ur=%d, vr_ur_in_rx_sdu=%d)\n", vr_ur, vr_ur_in_rx_sdu);
// Advance data pointers and continue with next segment
rx_window[vr_ur].buf->msg += len;
rx_window[vr_ur].buf->N_bytes -= len;
}
pdu_lost = false;
}
@ -833,8 +844,8 @@ void rlc_um::rlc_um_rx::reassemble_rx_sdus()
rx_window[vr_ur].buf->N_bytes < SRSLTE_MAX_BUFFER_SIZE_BYTES &&
rx_window[vr_ur].buf->N_bytes + rx_sdu->N_bytes < SRSLTE_MAX_BUFFER_SIZE_BYTES)
{
log->info_hex(rx_window[vr_ur].buf->msg, rx_window[vr_ur].buf->N_bytes, "Writing last segment in SDU buffer. Updating vr_ur=%d, Buffer size=%d, segment size=%d\n",
vr_ur, rx_sdu->N_bytes, rx_window[vr_ur].buf->N_bytes);
log->info_hex(rx_window[vr_ur].buf->msg, rx_window[vr_ur].buf->N_bytes, "Writing last segment in SDU buffer. Updating vr_ur=%d, vr_ur_in_rx_sdu=%d, Buffer size=%d, segment size=%d\n",
vr_ur, vr_ur_in_rx_sdu, rx_sdu->N_bytes, rx_window[vr_ur].buf->N_bytes);
memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, rx_window[vr_ur].buf->N_bytes);
rx_sdu->N_bytes += rx_window[vr_ur].buf->N_bytes;
} else {
@ -872,6 +883,18 @@ clean_up_rx_window:
}
}
// Only called when lock is hold
bool rlc_um::rlc_um_rx::pdu_belongs_to_rx_sdu()
{
// return true if the currently received SDU
if (((vr_ur_in_rx_sdu + 1)%cfg.rx_mod == vr_ur) || (vr_ur == vr_ur_in_rx_sdu)) {
return true;
}
return false;
}
// Only called when lock is hold
// 36.322 Section 5.1.2.2.1
bool rlc_um::rlc_um_rx::inside_reordering_window(uint16_t sn)

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