| /* Copied from tbf.cpp |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * Copyright (C) 2013 by Holger Hans Peter Freyther |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <bts.h> |
| #include <tbf.h> |
| #include <rlc.h> |
| #include <encoding.h> |
| #include <gprs_rlcmac.h> |
| #include <gprs_debug.h> |
| #include <gprs_bssgp_pcu.h> |
| #include <decoding.h> |
| #include <pcu_l1_if.h> |
| |
| extern "C" { |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/talloc.h> |
| } |
| |
| #include <errno.h> |
| #include <string.h> |
| |
| /* After receiving these frames, we send ack/nack. */ |
| #define SEND_ACK_AFTER_FRAMES 20 |
| |
| extern void *tall_pcu_ctx; |
| |
| |
| /* |
| * Store received block data in LLC message(s) and forward to SGSN |
| * if complete. |
| */ |
| int gprs_rlcmac_ul_tbf::assemble_forward_llc(const gprs_rlc_data *_data) |
| { |
| const uint8_t *data = _data->block; |
| uint8_t len = _data->len; |
| const struct rlc_ul_header *rh = (const struct rlc_ul_header *) data; |
| uint8_t e, m; |
| struct rlc_li_field *li; |
| uint8_t frame_offset[16], offset = 0, chunk; |
| int i, frames = 0; |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Assembling frames: (len=%d)\n", len); |
| |
| data += 3; |
| len -= 3; |
| e = rh->e; /* if extended */ |
| m = 1; /* more frames, that means: the first frame */ |
| |
| /* Parse frame offsets from length indicator(s), if any. */ |
| while (1) { |
| if (frames == (int)sizeof(frame_offset)) { |
| LOGP(DRLCMACUL, LOGL_ERROR, "%s too many frames in " |
| "block\n", tbf_name(this)); |
| return -EINVAL; |
| } |
| frame_offset[frames++] = offset; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "-- Frame %d starts at offset " |
| "%d\n", frames, offset); |
| if (!len) |
| break; |
| /* M == 0 and E == 0 is not allowed in this version. */ |
| if (!m && !e) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA " |
| "ignored, because M='0' and E='0'.\n", |
| tbf_name(this)); |
| return 0; |
| } |
| /* no more frames in this segment */ |
| if (e) { |
| break; |
| } |
| /* There is a new frame and an LI that delimits it. */ |
| if (m) { |
| li = (struct rlc_li_field *)data; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "-- Delimiter len=%d\n", |
| li->li); |
| /* Special case: LI == 0 |
| * If the last segment would fit precisely into the |
| * rest of the RLC MAC block, there would be no way |
| * to delimit that this segment ends and is not |
| * continued in the next block. |
| * The special LI (0) is used to force the segment to |
| * extend into the next block, so it is delimited there. |
| * This LI must be skipped. Also it is the last LI. |
| */ |
| if (li->li == 0) { |
| data++; |
| len--; |
| m = 1; /* M is ignored, we know there is more */ |
| break; /* handle E as '1', so we break! */ |
| } |
| e = li->e; |
| m = li->m; |
| offset += li->li; |
| data++; |
| len--; |
| continue; |
| } |
| } |
| if (!m) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Last frame carries spare " |
| "data\n"); |
| } |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Data length after length fields: %d\n", |
| len); |
| /* TLLI */ |
| if (rh->ti) { |
| if (len < 4) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA TLLI out of " |
| "frame border\n", tbf_name(this)); |
| return -EINVAL; |
| } |
| data += 4; |
| len -= 4; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping TLLI: " |
| "%d\n", len); |
| } |
| |
| /* PFI */ |
| if (rh->pi) { |
| LOGP(DRLCMACUL, LOGL_ERROR, "ERROR: PFI not supported, " |
| "please disable in SYSTEM INFORMATION\n"); |
| if (len < 1) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA PFI out of " |
| "frame border\n", tbf_name(this)); |
| return -EINVAL; |
| } |
| data++; |
| len--; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping PFI: " |
| "%d\n", len); |
| } |
| |
| /* Now we have: |
| * - a list of frames offsets: frame_offset[] |
| * - number of frames: i |
| * - m == 0: Last frame carries spare data (end of TBF). |
| */ |
| |
| /* Check if last offset would exceed frame. */ |
| if (offset > len) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA ignored, " |
| "because LI delimits data that exceeds block size.\n", |
| tbf_name(this)); |
| return -EINVAL; |
| } |
| |
| /* create LLC frames */ |
| for (i = 0; i < frames; i++) { |
| /* last frame ? */ |
| if (i == frames - 1) { |
| /* no more data in last frame */ |
| if (!m) |
| break; |
| /* data until end of frame */ |
| chunk = len - frame_offset[i]; |
| } else { |
| /* data until next frame */ |
| chunk = frame_offset[i + 1] - frame_offset[i]; |
| } |
| if (!m_llc.fits_in_current_frame(chunk)) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "%s LLC frame exceeds " |
| "maximum size %u.\n", tbf_name(this), |
| m_llc.remaining_space()); |
| chunk = m_llc.remaining_space(); |
| } |
| m_llc.append_frame(data + frame_offset[i], chunk); |
| m_llc.consume(chunk); |
| /* not last frame. */ |
| if (i != frames - 1) { |
| /* send frame to SGSN */ |
| LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame len=%d\n", |
| tbf_name(this) , m_llc.frame_length()); |
| snd_ul_ud(); |
| m_llc.reset(); |
| /* also check if CV==0, because the frame may fill up the |
| * block precisely, then it is also complete. normally the |
| * frame would be extended into the next block with a 0-length |
| * delimiter added to this block. */ |
| } else if (rh->cv == 0) { |
| /* send frame to SGSN */ |
| LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame " |
| "that fits precisely in last block: " |
| "len=%d\n", tbf_name(this), m_llc.frame_length()); |
| snd_ul_ud(); |
| m_llc.reset(); |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn) |
| { |
| int final = (state_is(GPRS_RLCMAC_FINISHED)); |
| struct msgb *msg; |
| |
| if (final) { |
| if (poll_state != GPRS_RLCMAC_POLL_NONE) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already " |
| "sheduled for %s, so we must wait for " |
| "final uplink ack...\n", tbf_name(this)); |
| return NULL; |
| } |
| if (bts->sba()->find(trx->trx_no, control_ts, (fn + 13) % 2715648)) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already " |
| "scheduled for single block allocation...\n"); |
| return NULL; |
| } |
| } |
| |
| msg = msgb_alloc(23, "rlcmac_ul_ack"); |
| if (!msg) |
| return NULL; |
| bitvec *ack_vec = bitvec_alloc(23); |
| if (!ack_vec) { |
| msgb_free(msg); |
| return NULL; |
| } |
| bitvec_unhex(ack_vec, |
| "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t); |
| Encoding::write_packet_uplink_ack(bts_data(), mac_control_block, this, final); |
| encode_gsm_rlcmac_downlink(ack_vec, mac_control_block); |
| bitvec_pack(ack_vec, msgb_put(msg, 23)); |
| bitvec_free(ack_vec); |
| talloc_free(mac_control_block); |
| |
| /* now we must set this flag, so we are allowed to assign downlink |
| * TBF on PACCH. it is only allowed when TLLI is acknowledged. */ |
| m_contention_resolution_done = 1; |
| |
| if (final) { |
| poll_state = GPRS_RLCMAC_POLL_SCHED; |
| poll_fn = (fn + 13) % 2715648; |
| /* waiting for final acknowledge */ |
| ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK; |
| m_final_ack_sent = 1; |
| } else |
| ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE; |
| |
| return msg; |
| } |
| |
| int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged(const uint8_t *data, |
| size_t len, struct pcu_l1_meas *meas) |
| { |
| struct rlc_ul_header *rh = (struct rlc_ul_header *)data; |
| int rc; |
| int8_t rssi = meas->have_rssi ? meas->rssi : 0; |
| |
| const uint16_t mod_sns = m_window.mod_sns(); |
| const uint16_t ws = m_window.ws(); |
| |
| this->state_flags |= (1 << GPRS_RLCMAC_FLAG_UL_DATA); |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TFI=%d received (V(Q)=%d .. " |
| "V(R)=%d)\n", rh->tfi, this->m_window.v_q(), |
| this->m_window.v_r()); |
| |
| /* process RSSI */ |
| gprs_rlcmac_rssi(this, rssi); |
| |
| /* store measurement values */ |
| if (ms()) |
| ms()->update_l1_meas(meas); |
| |
| /* get TLLI */ |
| if (!this->is_tlli_valid()) { |
| if (!extract_tlli(data, len)) |
| return 0; |
| /* already have TLLI, but we stille get another one */ |
| } else if (rh->ti) { |
| uint32_t tlli; |
| rc = Decoding::tlli_from_ul_data(data, len, &tlli); |
| if (rc) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI " |
| "of UL DATA TFI=%d.\n", rh->tfi); |
| return 0; |
| } |
| if (tlli != this->tlli()) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL " |
| "DATA TFI=%d. (Ignoring due to contention " |
| "resolution)\n", rh->tfi); |
| return 0; |
| } |
| } |
| |
| /* restart T3169 */ |
| tbf_timer_start(this, 3169, bts_data()->t3169, 0); |
| |
| /* Increment RX-counter */ |
| this->m_rx_counter++; |
| |
| if (!m_window.is_in_window(rh->bsn)) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window " |
| "%d..%d (it's normal)\n", rh->bsn, |
| m_window.v_q(), |
| (m_window.v_q() + ws - 1) & mod_sns); |
| maybe_schedule_uplink_acknack(rh); |
| return 0; |
| } |
| |
| /* Write block to buffer and set receive state array. */ |
| m_rlc.block(rh->bsn)->put_data(data, len); |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n", |
| rh->bsn, m_window.v_q(), |
| (m_window.v_q() + ws - 1) & mod_sns); |
| |
| /* Raise V(Q) if possible, and retrieve LLC frames from blocks. |
| * This is looped until there is a gap (non received block) or |
| * the window is empty.*/ |
| const uint16_t v_q_beg = m_window.v_q(); |
| |
| const uint16_t count = m_window.receive_bsn(rh->bsn); |
| |
| /* Retrieve LLC frames from blocks that are ready */ |
| for (uint16_t i = 0; i < count; ++i) { |
| uint16_t index = (v_q_beg + i) & mod_sns; |
| assemble_forward_llc(m_rlc.block(index)); |
| } |
| |
| /* Check CV of last frame in buffer */ |
| if (this->state_is(GPRS_RLCMAC_FLOW) /* still in flow state */ |
| && this->m_window.v_q() == this->m_window.v_r()) { /* if complete */ |
| struct rlc_ul_header *last_rh = (struct rlc_ul_header *) |
| m_rlc.block((m_window.v_r() - 1) & mod_sns)->block; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- No gaps in received block, " |
| "last block: BSN=%d CV=%d\n", last_rh->bsn, |
| last_rh->cv); |
| if (last_rh->cv == 0) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Finished with UL " |
| "TBF\n"); |
| set_state(GPRS_RLCMAC_FINISHED); |
| /* Reset N3103 counter. */ |
| this->m_n3103 = 0; |
| } |
| } |
| |
| /* If TLLI is included or if we received half of the window, we send |
| * an ack/nack */ |
| maybe_schedule_uplink_acknack(rh); |
| |
| return 0; |
| } |
| |
| void gprs_rlcmac_ul_tbf::maybe_schedule_uplink_acknack(const rlc_ul_header *rh) |
| { |
| if (rh->si || rh->ti || state_is(GPRS_RLCMAC_FINISHED) |
| || (m_rx_counter % SEND_ACK_AFTER_FRAMES) == 0) { |
| if (rh->si) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "- Scheduling Ack/Nack, " |
| "because MS is stalled.\n"); |
| } |
| if (rh->ti) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because TLLI is included.\n"); |
| } |
| if (state_is(GPRS_RLCMAC_FINISHED)) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because last block has CV==0.\n"); |
| } |
| if ((m_rx_counter % SEND_ACK_AFTER_FRAMES) == 0) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because %d frames received.\n", |
| SEND_ACK_AFTER_FRAMES); |
| } |
| if (ul_ack_state == GPRS_RLCMAC_UL_ACK_NONE) { |
| /* trigger sending at next RTS */ |
| ul_ack_state = GPRS_RLCMAC_UL_ACK_SEND_ACK; |
| } else { |
| /* already triggered */ |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Sending Ack/Nack is " |
| "already triggered, don't schedule!\n"); |
| } |
| } |
| } |
| |
| /* Send Uplink unit-data to SGSN. */ |
| int gprs_rlcmac_ul_tbf::snd_ul_ud() |
| { |
| uint8_t qos_profile[3]; |
| struct msgb *llc_pdu; |
| unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + m_llc.frame_length(); |
| struct bssgp_bvc_ctx *bctx = gprs_bssgp_pcu_current_bctx(); |
| |
| LOGP(DBSSGP, LOGL_INFO, "LLC [PCU -> SGSN] %s len=%d\n", tbf_name(this), m_llc.frame_length()); |
| if (!bctx) { |
| LOGP(DBSSGP, LOGL_ERROR, "No bctx\n"); |
| m_llc.reset_frame_space(); |
| return -EIO; |
| } |
| |
| llc_pdu = msgb_alloc_headroom(msg_len, msg_len,"llc_pdu"); |
| uint8_t *buf = msgb_push(llc_pdu, TL16V_GROSS_LEN(sizeof(uint8_t)*m_llc.frame_length())); |
| tl16v_put(buf, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*m_llc.frame_length(), m_llc.frame); |
| qos_profile[0] = QOS_PROFILE >> 16; |
| qos_profile[1] = QOS_PROFILE >> 8; |
| qos_profile[2] = QOS_PROFILE; |
| bssgp_tx_ul_ud(bctx, tlli(), qos_profile, llc_pdu); |
| |
| m_llc.reset_frame_space(); |
| return 0; |
| } |
| |