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-rw-r--r--src/gprs_rlcmac_data.c1461
1 files changed, 1461 insertions, 0 deletions
diff --git a/src/gprs_rlcmac_data.c b/src/gprs_rlcmac_data.c
new file mode 100644
index 0000000..0efcb79
--- /dev/null
+++ b/src/gprs_rlcmac_data.c
@@ -0,0 +1,1461 @@
+/* Data block transfer
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * 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 <gprs_bssgp_pcu.h>
+#include <gprs_rlcmac.h>
+#include <gprs_rlcmac_ctrl.h>
+#include <pcu_l1_if.h>
+
+extern void *tall_pcu_ctx;
+
+int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
+ uint8_t num_frames, uint32_t num_octets);
+
+/* After receiving these frames, we send ack/nack. */
+#define SEND_ACK_AFTER_FRAMES 20
+
+/* After sending these frames, we poll for ack/nack. */
+#define POLL_ACK_AFTER_FRAMES 10
+
+/* If acknowledgement to uplink/downlin assignmentshould be polled */
+#define POLLING_ASSIGNMENT 0
+
+/* TS 04.60 10.2.2 */
+struct rlc_ul_header {
+ uint8_t r:1,
+ si:1,
+ cv:4,
+ pt:2;
+ uint8_t ti:1,
+ tfi:5,
+ pi:1,
+ spare:1;
+ uint8_t e:1,
+ bsn:7;
+} __attribute__ ((packed));
+
+struct rlc_dl_header {
+ uint8_t usf:3,
+ s_p:1,
+ rrbp:2,
+ pt:2;
+ uint8_t fbi:1,
+ tfi:5,
+ pr:2;
+ uint8_t e:1,
+ bsn:7;
+} __attribute__ ((packed));
+
+struct rlc_li_field {
+ uint8_t e:1,
+ m:1,
+ li:6;
+} __attribute__ ((packed));
+
+int gprs_rlcmac_poll_timeout(struct gprs_rlcmac_tbf *tbf)
+{
+ LOGP(DRLCMAC, LOGL_NOTICE, "Poll timeout for %s TBF=%d\n",
+ (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi);
+
+ tbf->poll_state = GPRS_RLCMAC_POLL_NONE;
+
+ if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET "
+ "CONTROL ACK for PACKET UPLINK ACK\n");
+ tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
+ if (tbf->state == GPRS_RLCMAC_FINISHED) {
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+
+ tbf->dir.ul.n3103++;
+ if (tbf->dir.ul.n3103 == bts->n3103) {
+ LOGP(DRLCMAC, LOGL_NOTICE,
+ "- N3103 exceeded\n");
+ tbf_new_state(tbf, GPRS_RLCMAC_RELEASING);
+ tbf_timer_start(tbf, 3169, bts->t3169, 0);
+ return 0;
+ }
+ /* reschedule UL ack */
+ tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_SEND_ACK;
+ }
+ } else
+ if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET "
+ "CONTROL ACK for PACKET UPLINK ASSIGNMENT.\n");
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
+ } else
+ if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET "
+ "CONTROL ACK for PACKET DOWNLINK ASSIGNMENT.\n");
+ tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
+ /* in case out downlink assigment failed: */
+ if (tbf->state == GPRS_RLCMAC_ASSIGN) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Assignment failed\n");
+ tbf_free(tbf);
+ }
+ } else
+ if (tbf->direction == GPRS_RLCMAC_DL_TBF)
+ {
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET "
+ " DOWNLINK ACK.\n");
+ tbf->dir.dl.n3105++;
+ if (tbf->dir.dl.n3105 == bts->n3105) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- N3105 exceeded\n");
+ tbf_new_state(tbf, GPRS_RLCMAC_RELEASING);
+ tbf_timer_start(tbf, 3195, bts->t3195, 0);
+ return 0;
+ }
+ } else
+ LOGP(DRLCMAC, LOGL_ERROR, "- Poll Timeout, but no event!\n");
+
+ return 0;
+}
+
+int gprs_rlcmac_rcv_control_ack(uint8_t trx, uint8_t ts, uint32_t fn,
+ uint32_t tlli)
+{
+ struct gprs_rlcmac_tbf *tbf;
+ uint8_t tfi;
+
+ tbf = tbf_by_poll_fn(fn, trx, ts);
+ if (!tbf) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "PACKET CONTROL ACK with "
+ "unknown FN=%u TLL=0x%08x (TRX %d TS %d)\n",
+ fn, tlli, trx, ts);
+ return -EINVAL;
+ }
+ tfi = tbf->tfi;
+ if (tlli != tbf->tlli) {
+ LOGP(DRLCMAC, LOGL_INFO, "Phone changed TLLI to "
+ "0x%08x\n", tlli);
+ tbf->tlli = tlli;
+ }
+ LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Control Ack\n", tbf->tfi, tbf->tlli);
+ tbf->poll_state = GPRS_RLCMAC_POLL_NONE;
+
+ /* check if this control ack belongs to packet uplink ack */
+ if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
+ tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
+ tbf_free(tbf);
+ return 0;
+ }
+ if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] DOWNLINK ASSIGNED TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
+ tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
+ if (tbf->direction == GPRS_RLCMAC_UL_TBF)
+ tbf = tbf_by_tlli(tbf->tlli,
+ GPRS_RLCMAC_DL_TBF);
+ if (!tbf) {
+ LOGP(DRLCMAC, LOGL_ERROR, "Got ACK, but DL "
+ "TBF is gone\n");
+ return -EIO;
+ }
+ tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+ tbf_assign_control_ts(tbf);
+ return 0;
+ }
+ if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_WAIT_ACK) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [DOWNLINK] UPLINK ASSIGNED TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
+ if (tbf->direction == GPRS_RLCMAC_DL_TBF)
+ tbf = tbf_by_tlli(tbf->tlli,
+ GPRS_RLCMAC_UL_TBF);
+ if (!tbf) {
+ LOGP(DRLCMAC, LOGL_ERROR, "Got ACK, but UL "
+ "TBF is gone\n");
+ return -EIO;
+ }
+ tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+ tbf_assign_control_ts(tbf);
+ return 0;
+ }
+ LOGP(DRLCMAC, LOGL_ERROR, "Error: received PACET CONTROL ACK "
+ "at no request\n");
+ return EINVAL;
+}
+
+int gprs_rlcmac_rcv_downlink_ack(uint8_t trx, uint8_t ts, uint32_t fn, uint16_t tfi, uint8_t final, uint8_t ssn, uint8_t *rbb, uint8_t request)
+{
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+ struct gprs_rlcmac_tbf *tbf;
+ int rc;
+
+ tbf = tbf_by_poll_fn(fn, trx, ts);
+ if (!tbf) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "PACKET DOWNLINK ACK with "
+ "unknown FN=%u TBF=%d (TRX %d TS %d)\n",
+ fn, tfi, trx, ts);
+ return -EINVAL;
+ }
+ /* reset N3105 */
+ tbf->dir.dl.n3105 = 0;
+ /* stop timer T3191 */
+ tbf_timer_stop(tbf);
+ LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Downlink Ack/Nack\n", tbf->tfi, tbf->tlli);
+ tbf->poll_state = GPRS_RLCMAC_POLL_NONE;
+
+ rc = gprs_rlcmac_downlink_ack(tbf, final, ssn, rbb);
+ if (rc == 1) {
+ tbf_free(tbf);
+ return 0;
+ }
+ /* check for channel request */
+ if (request) {
+ uint8_t trx, ts;
+ struct gprs_rlcmac_tbf *ul_tbf;
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
+ "message, so we provide one:\n");
+ /* create new TBF, use sme TRX as DL TBF */
+ tfi = tfi_alloc(GPRS_RLCMAC_UL_TBF, &trx, &ts, tbf->trx, tbf->first_ts);
+ if (tfi < 0) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
+ /* FIXME: send reject */
+ return -EIO;
+ }
+ /* use multislot class of downlink TBF */
+ ul_tbf = tbf_alloc(tbf, GPRS_RLCMAC_UL_TBF, tfi, trx,
+ ts, tbf->ms_class, 0);
+ if (!ul_tbf) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
+ /* FIXME: send reject */
+ return -EIO;
+ }
+ ul_tbf->tlli = tbf->tlli;
+ ul_tbf->tlli_valid = 1; /* no contention resolution */
+ ul_tbf->dir.ul.contention_resolution_done = 1;
+ ul_tbf->ta = tbf->ta; /* use current TA */
+ tbf_new_state(ul_tbf, GPRS_RLCMAC_ASSIGN);
+ tbf_timer_start(ul_tbf, 3169, bts->t3169, 0);
+ /* schedule uplink assignment */
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+ }
+
+ return 0;
+}
+
+#ifdef DEBUG_DL_ASS_IDLE
+ char debug_imsi[16];
+#endif
+
+void tbf_timer_cb(void *_tbf)
+{
+ struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf;
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "%s TBF=%d timer %u expired.\n",
+ (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi,
+ tbf->T);
+
+ tbf->num_T_exp++;
+
+ switch (tbf->T) {
+#ifdef DEBUG_DL_ASS_IDLE
+ case 1234:
+ gprs_rlcmac_trigger_downlink_assignment(tbf, NULL, debug_imsi);
+ break;
+#endif
+ case 0: /* assignment */
+ /* change state to FLOW, so scheduler will start transmission */
+ if (tbf->state == GPRS_RLCMAC_ASSIGN) {
+ tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+ tbf_assign_control_ts(tbf);
+ } else
+ LOGP(DRLCMAC, LOGL_ERROR, "Error: TBF is not in assign "
+ "state\n");
+ break;
+ case 3169:
+ case 3191:
+ case 3195:
+ LOGP(DRLCMAC, LOGL_NOTICE, "TBF T%d timeout during "
+ "transsmission\n", tbf->T);
+ /* fall through */
+ case 3193:
+ LOGP(DRLCMAC, LOGL_DEBUG, "TBF will be freed due to timeout\n");
+ /* free TBF */
+ tbf_free(tbf);
+ break;
+ default:
+ LOGP(DRLCMAC, LOGL_ERROR, "Timer expired in unknown mode: %u\n",
+ tbf->T);
+ }
+}
+
+/*
+ * UL data block flow
+ */
+
+/* get TLLI from received UL data block */
+static int tlli_from_ul_data(uint8_t *data, uint8_t len, uint32_t *tlli)
+{
+ struct rlc_ul_header *rh = (struct rlc_ul_header *)data;
+ struct rlc_li_field *li;
+ uint8_t e;
+
+ if (!rh->ti)
+ return -EINVAL;
+
+ data += 3;
+ len -= 3;
+ e = rh->e;
+ /* if E is not set (LI follows) */
+ while (!e) {
+ if (!len) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA LI extended, "
+ "but no more data\n");
+ return -EINVAL;
+ }
+ /* get new E */
+ li = (struct rlc_li_field *)data;
+ if (li->e == 0) /* if LI==0, E is interpreted as '1' */
+ e = 1;
+ else
+ e = li->e;
+ data++;
+ len--;
+ }
+ if (len < 4) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TLLI out of frame "
+ "border\n");
+ return -EINVAL;
+ }
+ *tlli = ntohl(*((uint32_t *)data));
+
+ return 0;
+}
+
+/* Store received block data in LLC message(s) and forward to SGSN if complete.
+ */
+static int gprs_rlcmac_assemble_llc(struct gprs_rlcmac_tbf *tbf, uint8_t *data,
+ uint8_t len)
+{
+ struct rlc_ul_header *rh = (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, "Too many frames in "
+ "block\n");
+ 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, "UL DATA TBF=%d "
+ "ignored, because M='0' and E='0'.\n",
+ tbf->tfi);
+ 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, "UL DATA TLLI out of "
+ "frame border\n");
+ 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, "UL DATA PFI out of "
+ "frame border\n");
+ 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, "UL DATA TBF=%d ignored, "
+ "because LI delimits data that exceeds block size.\n",
+ tbf->tfi);
+ 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];
+ }
+ LOGP(DRLCMACUL, LOGL_DEBUG, "-- Appending chunk (len=%d) to "
+ "frame at %d.\n", chunk, tbf->llc_index);
+ if (tbf->llc_index + chunk > LLC_MAX_LEN) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "LLC frame exceeds "
+ "maximum size.\n");
+ chunk = LLC_MAX_LEN - tbf->llc_index;
+ }
+ memcpy(tbf->llc_frame + tbf->llc_index, data + frame_offset[i],
+ chunk);
+ tbf->llc_index += chunk;
+ /* not last frame. */
+ if (i != frames - 1) {
+ /* send frame to SGSN */
+ LOGP(DRLCMACUL, LOGL_INFO, "Complete UL frame for "
+ "TBF=%d: len=%d\n", tbf->tfi, tbf->llc_index);
+ gprs_rlcmac_tx_ul_ud(tbf);
+ tbf->llc_index = 0; /* reset frame space */
+ /* 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, "Complete UL frame for "
+ "TBF=%d that fits precisely in last block: "
+ "len=%d\n", tbf->tfi, tbf->llc_index);
+ gprs_rlcmac_tx_ul_ud(tbf);
+ tbf->llc_index = 0; /* reset frame space */
+ }
+ }
+
+ return 0;
+}
+
+struct msgb *gprs_rlcmac_send_uplink_ack(struct gprs_rlcmac_tbf *tbf,
+ uint32_t fn)
+{
+ int final = (tbf->state == GPRS_RLCMAC_FINISHED);
+ struct msgb *msg;
+
+ if (final && tbf->poll_state != GPRS_RLCMAC_POLL_NONE) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
+ "sheduled for TBF=%d, so we must wait for final uplink "
+ "ack...\n", tbf->tfi);
+ return NULL;
+ }
+
+ msg = write_packet_uplink_ack(tbf, final);
+ if (!msg)
+ return NULL;
+
+ /* now we must set this flag, so we are allowed to assign downlink
+ * TBF on PACCH. it is only allowed when TLLI is aknowledged. */
+ tbf->dir.ul.contention_resolution_done = 1;
+
+ if (final) {
+ tbf->poll_state = GPRS_RLCMAC_POLL_SCHED;
+ tbf->poll_fn = (fn + 13) % 2715648;
+ /* waiting for final acknowledge */
+ tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK;
+ tbf->dir.ul.final_ack_sent = 1;
+ } else
+ tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
+
+ return msg;
+}
+
+/* receive UL data block
+ *
+ * The blocks are defragmented and forwarded as LLC frames, if complete.
+ */
+int gprs_rlcmac_rcv_data_block_acknowledged(uint8_t trx, uint8_t ts,
+ uint8_t *data, uint8_t len)
+{
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+ struct gprs_rlcmac_tbf *tbf;
+ struct rlc_ul_header *rh = (struct rlc_ul_header *)data;
+ uint16_t mod_sns, mod_sns_half, offset_v_q, offset_v_r, index;
+ int rc;
+
+ switch (len) {
+ case 54:
+ /* omitting spare bits */
+ len = 53;
+ break;
+ case 40:
+ /* omitting spare bits */
+ len = 39;
+ break;
+ case 34:
+ /* omitting spare bits */
+ len = 33;
+ break;
+ case 23:
+ break;
+ default:
+ LOGP(DRLCMACUL, LOGL_ERROR, "Dropping data block with invalid"
+ "length: %d)\n", len);
+ return -EINVAL;
+ }
+
+ /* find TBF inst from given TFI */
+ tbf = tbf_by_tfi(rh->tfi, trx, ts, GPRS_RLCMAC_UL_TBF);
+ if (!tbf) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA unknown TBF=%d\n",
+ rh->tfi);
+ return 0;
+ }
+
+ LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TBF=%d received (V(Q)=%d .. "
+ "V(R)=%d)\n", rh->tfi, tbf->dir.ul.v_q, tbf->dir.ul.v_r);
+
+ /* get TLLI */
+ if (!tbf->tlli_valid) {
+ struct gprs_rlcmac_tbf *dl_tbf;
+
+ /* no TLLI yet */
+ if (!rh->ti) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TBF=%d without "
+ "TLLI, but no TLLI received yet\n", rh->tfi);
+ return 0;
+ }
+ rc = tlli_from_ul_data(data, len, &tbf->tlli);
+ if (rc) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI "
+ "of UL DATA TBF=%d.\n", rh->tfi);
+ return 0;
+ }
+ tbf->tlli_valid = 1;
+ LOGP(DRLCMACUL, LOGL_INFO, "Decoded premier TLLI=0x%08x of "
+ "UL DATA TBF=%d.\n", tbf->tlli, rh->tfi);
+ if ((dl_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_DL_TBF))) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "Got RACH from "
+ "TLLI=0x%08x while DL TBF=%d still exists. "
+ "Killing pending DL TBF\n", tbf->tlli,
+ dl_tbf->tfi);
+ tbf_free(dl_tbf);
+ }
+ /* already have TLLI, but we stille get another one */
+ } else if (rh->ti) {
+ uint32_t tlli;
+ rc = tlli_from_ul_data(data, len, &tlli);
+ if (rc) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI "
+ "of UL DATA TBF=%d.\n", rh->tfi);
+ return 0;
+ }
+ if (tlli != tbf->tlli) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL "
+ "DATA TBF=%d. (Ignoring due to contention "
+ "resolution)\n", rh->tfi);
+ return 0;
+ }
+ }
+
+ mod_sns = tbf->sns - 1;
+ mod_sns_half = (tbf->sns >> 1) - 1;
+
+ /* restart T3169 */
+ tbf_timer_start(tbf, 3169, bts->t3169, 0);
+
+ /* Increment RX-counter */
+ tbf->dir.ul.rx_counter++;
+
+ /* current block relative to lowest unreceived block */
+ offset_v_q = (rh->bsn - tbf->dir.ul.v_q) & mod_sns;
+ /* If out of window (may happen if blocks below V(Q) are received
+ * again. */
+ if (offset_v_q >= tbf->ws) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window "
+ "%d..%d (it's normal)\n", rh->bsn, tbf->dir.ul.v_q,
+ (tbf->dir.ul.v_q + tbf->ws - 1) & mod_sns);
+ return 0;
+ }
+ /* Write block to buffer and set receive state array. */
+ index = rh->bsn & mod_sns_half; /* memory index of block */
+ memcpy(tbf->rlc_block[index], data, len); /* Copy block. */
+ tbf->rlc_block_len[index] = len;
+ tbf->dir.ul.v_n[index] = 'R'; /* Mark received block. */
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n",
+ rh->bsn, tbf->dir.ul.v_q,
+ (tbf->dir.ul.v_q + tbf->ws - 1) & mod_sns);
+ /* Raise V(R) to highest received sequence number not received. */
+ offset_v_r = (rh->bsn + 1 - tbf->dir.ul.v_r) & mod_sns;
+ if (offset_v_r < (tbf->sns >> 1)) { /* Positive offset, so raise. */
+ while (offset_v_r--) {
+ if (offset_v_r) /* all except the received block */
+ tbf->dir.ul.v_n[tbf->dir.ul.v_r & mod_sns_half]
+ = 'N'; /* Mark block as not received */
+ tbf->dir.ul.v_r = (tbf->dir.ul.v_r + 1) & mod_sns;
+ /* Inc V(R). */
+ }
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Raising V(R) to %d\n",
+ tbf->dir.ul.v_r);
+ }
+
+ /* 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.*/
+ while (tbf->dir.ul.v_q != tbf->dir.ul.v_r && tbf->dir.ul.v_n[
+ (index = tbf->dir.ul.v_q & mod_sns_half)] == 'R') {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Taking block %d out, raising "
+ "V(Q) to %d\n", tbf->dir.ul.v_q,
+ (tbf->dir.ul.v_q + 1) & mod_sns);
+ /* get LLC data from block */
+ gprs_rlcmac_assemble_llc(tbf, tbf->rlc_block[index],
+ tbf->rlc_block_len[index]);
+ /* raise V(Q), because block already received */
+ tbf->dir.ul.v_q = (tbf->dir.ul.v_q + 1) & mod_sns;
+ }
+
+ /* Check CV of last frame in buffer */
+ if (tbf->state == GPRS_RLCMAC_FLOW /* still in flow state */
+ && tbf->dir.ul.v_q == tbf->dir.ul.v_r) { /* if complete */
+ struct rlc_ul_header *last_rh = (struct rlc_ul_header *)
+ tbf->rlc_block[(tbf->dir.ul.v_r - 1) & mod_sns_half];
+ 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");
+ tbf_new_state(tbf, GPRS_RLCMAC_FINISHED);
+ /* Reset N3103 counter. */
+ tbf->dir.ul.n3103 = 0;
+ }
+ }
+
+ /* If TLLI is included or if we received half of the window, we send
+ * an ack/nack */
+ if (rh->si || rh->ti || tbf->state == GPRS_RLCMAC_FINISHED
+ || (tbf->dir.ul.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 (tbf->state == GPRS_RLCMAC_FINISHED) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
+ "because last block has CV==0.\n");
+ }
+ if ((tbf->dir.ul.rx_counter % SEND_ACK_AFTER_FRAMES) == 0) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
+ "because %d frames received.\n",
+ SEND_ACK_AFTER_FRAMES);
+ }
+ if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_NONE) {
+ /* trigger sending at next RTS */
+ tbf->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");
+ }
+ }
+
+ return 0;
+}
+
+struct msgb *gprs_rlcmac_send_packet_uplink_assignment(
+ struct gprs_rlcmac_tbf *tbf, uint32_t fn)
+{
+ struct msgb *msg;
+ struct gprs_rlcmac_tbf *new_tbf;
+
+#if POLLING_ASSIGNMENT == 1
+ if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
+ "sheduled for TBF=%d, so we must wait for uplink "
+ "assignment...\n", tbf->tfi);
+ return NULL;
+ }
+#endif
+
+ /* on down TBF we get the uplink TBF to be assigned. */
+ if (tbf->direction == GPRS_RLCMAC_DL_TBF)
+ new_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_UL_TBF);
+ else
+ new_tbf = tbf;
+
+ if (!new_tbf) {
+ LOGP(DRLCMACUL, LOGL_ERROR, "We have a schedule for uplink "
+ "assignment at downlink TBF=%d, but there is no uplink "
+ "TBF\n", tbf->tfi);
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
+ return NULL;
+ }
+
+ LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Uplink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli);
+
+ msg = write_packet_uplink_assignment(tbf->tfi,
+ (tbf->direction == GPRS_RLCMAC_DL_TBF), 0, 0, new_tbf,
+ POLLING_ASSIGNMENT);
+ if (!msg)
+ return NULL;
+
+#if POLLING_ASSIGNMENT == 1
+ FIXME process does not work, also the acknowledgement is not checked.
+ tbf->poll_state = GPRS_RLCMAC_POLL_SCHED;
+ tbf->poll_fn = (fn + 13) % 2715648;
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_WAIT_ACK;
+#else
+ tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
+ tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW);
+ tbf_assign_control_ts(new_tbf);
+#endif
+
+ return msg;
+}
+
+int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta)
+{
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+ struct gprs_rlcmac_tbf *tbf;
+ uint8_t trx, ts;
+ int8_t tfi; /* must be signed */
+ uint8_t imm_ass[23];
+ int rc;
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF on RACH, so we provide "
+ "one:\n");
+ // Create new TBF
+ tfi = tfi_alloc(GPRS_RLCMAC_UL_TBF, &trx, &ts, -1, -1);
+ if (tfi < 0) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
+ /* FIXME: send reject */
+ return -EBUSY;
+ }
+ /* set class to 0, since we don't know the multislot class yet */
+ tbf = tbf_alloc(NULL, GPRS_RLCMAC_UL_TBF, tfi, trx, ts, 0, 1);
+ if (!tbf) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
+ /* FIXME: send reject */
+ return -EBUSY;
+ }
+ if (qta < 0)
+ qta = 0;
+ if (qta > 252)
+ qta = 252;
+ tbf->ta = qta >> 2;
+ tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+ tbf_timer_start(tbf, 3169, bts->t3169, 0);
+ LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] START TFI: %u\n", tbf->tfi);
+ LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u RACH qbit-ta=%d ra=%d, Fn=%d (%d,%d,%d)\n", tbf->tfi, qta, ra, Fn, (Fn / (26 * 51)) % 32, Fn % 51, Fn % 26);
+ LOGP(DRLCMAC, LOGL_INFO, "TX: START TFI: %u Immediate Assignment Uplink (AGCH)\n", tbf->tfi);
+ rc = write_immediate_assignment_uplink(imm_ass, ra, Fn, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, tbf->dir.ul.usf[tbf->first_ts], 0, 0);
+ if (rc < 0)
+ return rc;
+
+ pcu_l1if_tx_agch(imm_ass);
+ return 0;
+}
+
+
+/*
+ * DL data block flow
+ */
+
+static struct msgb *llc_dequeue(struct gprs_rlcmac_tbf *tbf)
+{
+ struct msgb *msg;
+ struct timeval *tv, tv_now;
+ uint32_t octets = 0, frames = 0;
+
+ gettimeofday(&tv_now, NULL);
+
+ while ((msg = msgb_dequeue(&tbf->llc_queue))) {
+ tv = (struct timeval *)msg->data;
+ msgb_pull(msg, sizeof(*tv));
+ if (tv->tv_sec /* not infinite */
+ && (tv_now.tv_sec > tv->tv_sec /* and secs expired */
+ || (tv_now.tv_sec == tv->tv_sec /* .. or if secs equal .. */
+ && tv_now.tv_usec > tv->tv_usec))) { /* .. usecs expired */
+ LOGP(DRLCMACDL, LOGL_NOTICE, "Discarding LLC PDU of "
+ "DL TBF=%d, because lifetime limit reached\n",
+ tbf->tfi);
+ frames++;
+ octets += msg->len;
+ msgb_free(msg);
+ continue;
+ }
+ break;
+ }
+
+ if (frames) {
+ if (frames > 0xff)
+ frames = 0xff;
+ if (octets > 0xffffff)
+ octets = 0xffffff;
+ bssgp_tx_llc_discarded(bctx, tbf->tlli, frames, octets);
+ }
+
+ return msg;
+}
+
+static int gprs_rlcmac_debug_bw(struct gprs_rlcmac_tbf *tbf, uint16_t octets)
+{
+ struct timeval now_tv, *bw_tv = &tbf->bw_tv;
+ uint32_t elapsed;
+
+ tbf->bw_octets += octets;
+
+ gettimeofday(&now_tv, NULL);
+ elapsed = ((now_tv.tv_sec - bw_tv->tv_sec) << 7)
+ + ((now_tv.tv_usec - bw_tv->tv_usec) << 7) / 1000000;
+ if (elapsed < 128)
+ return 0;
+
+ LOGP(DRLCMACBW, LOGL_DEBUG, "DL Bandwitdh of TLLI=0x%08x: %d KBits/s\n",
+ tbf->tlli, tbf->bw_octets / elapsed);
+
+ /* reset bandwidth values timestamp */
+ memcpy(bw_tv, &now_tv, sizeof(struct timeval));
+ tbf->bw_octets = 0;
+
+ return 0;
+}
+
+/* send DL data block
+ *
+ * The messages are fragmented and forwarded as data blocks.
+ */
+struct msgb *gprs_rlcmac_send_data_block_acknowledged(
+ struct gprs_rlcmac_tbf *tbf, uint32_t fn, uint8_t ts)
+{
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+ struct rlc_dl_header *rh;
+ struct rlc_li_field *li;
+ uint8_t block_length; /* total length of block, including spare bits */
+ uint8_t block_data; /* usable data of block, w/o spare bits, inc. MAC */
+ struct msgb *msg, *dl_msg;
+ uint8_t bsn;
+ uint16_t mod_sns = tbf->sns - 1;
+ uint16_t mod_sns_half = (tbf->sns >> 1) - 1;
+ uint16_t index;
+ uint8_t *delimiter, *data, *e_pointer;
+ uint8_t len;
+ uint16_t space, chunk;
+
+ LOGP(DRLCMACDL, LOGL_DEBUG, "DL DATA TBF=%d downlink (V(A)==%d .. "
+ "V(S)==%d)\n", tbf->tfi, tbf->dir.dl.v_a, tbf->dir.dl.v_s);
+
+do_resend:
+ /* check if there is a block with negative acknowledgement */
+ for (bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s;
+ bsn = (bsn + 1) & mod_sns) {
+ index = (bsn & mod_sns_half);
+ if (tbf->dir.dl.v_b[index] == 'N'
+ || tbf->dir.dl.v_b[index] == 'X') {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Resending BSN %d\n",
+ bsn);
+ /* re-send block with negative aknowlegement */
+ tbf->dir.dl.v_b[index] = 'U'; /* unacked */
+ goto tx_block;
+ }
+ }
+
+ /* if the window has stalled, or transfer is complete,
+ * send an unacknowledged block */
+ if (tbf->state == GPRS_RLCMAC_FINISHED
+ || ((tbf->dir.dl.v_s - tbf->dir.dl.v_a) & mod_sns) == tbf->ws) {
+ int resend = 0;
+
+ if (tbf->state == GPRS_RLCMAC_FINISHED)
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, "
+ "because all blocks have been transmitted.\n",
+ tbf->dir.dl.v_a);
+ else
+ LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, "
+ "because all window is stalled.\n",
+ tbf->dir.dl.v_a);
+ /* If V(S) == V(A) and finished state, we would have received
+ * acknowledgement of all transmitted block. In this case we
+ * would have transmitted the final block, and received ack
+ * from MS. But in this case we did not receive the final ack
+ * indication from MS. This should never happen if MS works
+ * correctly. */
+ if (tbf->dir.dl.v_s == tbf->dir.dl.v_a) {
+ LOGP(DRLCMACDL, LOGL_ERROR, "- MS acked all block, "
+ "but we still transmitting!\n");
+ /* we just send final block again */
+ index = ((tbf->dir.dl.v_s - 1) & mod_sns_half);
+ goto tx_block;
+ }
+
+ /* cycle through all unacked blocks */
+ for (bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s;
+ bsn = (bsn + 1) & mod_sns) {
+ index = (bsn & mod_sns_half);
+ if (tbf->dir.dl.v_b[index] == 'U') {
+ /* mark to be re-send */
+ tbf->dir.dl.v_b[index] = 'X';
+ resend++;
+ }
+ }
+ /* At this point there should be at leasst one unacked block
+ * to be resent. If not, this is an software error. */
+ if (resend == 0) {
+ LOGP(DRLCMACDL, LOGL_ERROR, "Software error: "
+ "There are no unacknowledged blocks, but V(A) "
+ " != V(S). PLEASE FIX!\n");
+ /* we just send final block again */
+ index = ((tbf->dir.dl.v_s - 1) & mod_sns_half);
+ goto tx_block;
+ }
+ goto do_resend;
+ }
+
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d\n",
+ tbf->dir.dl.v_s);
+
+ /* now we still have untransmitted LLC data, so we fill mac block */
+ index = tbf->dir.dl.v_s & mod_sns_half;
+ data = tbf->rlc_block[index];
+ switch (bts->initial_cs) {
+ case 2: /* CS-2 */
+ block_length = 34;
+ block_data = 33;
+ break;
+ case 3: /* CS-3 */
+ block_length = 40;
+ block_data = 39;
+ break;
+ case 4: /* CS-4 */
+ block_length = 54;
+ block_data = 53;
+ break;
+ default: /* CS-1 */
+ block_length = 23;
+ block_data = 23;
+ }
+ memset(data, 0x2b, block_data); /* spare bits will be left 0 */
+ rh = (struct rlc_dl_header *)data;
+ rh->pt = 0; /* Data Block */
+ rh->rrbp = rh->s_p = 0; /* Polling, set later, if required */
+ rh->usf = 7; /* will be set at scheduler */
+ rh->pr = 0; /* FIXME: power reduction */
+ rh->tfi = tbf->tfi; /* TFI */
+ rh->fbi = 0; /* Final Block Indicator, set late, if true */
+ rh->bsn = tbf->dir.dl.v_s; /* Block Sequence Number */
+ rh->e = 0; /* Extension bit, maybe set later */
+ e_pointer = data + 2; /* points to E of current chunk */
+ data += 3;
+ delimiter = data; /* where next length header would be stored */
+ space = block_data - 3;
+ while (1) {
+ chunk = tbf->llc_length - tbf->llc_index;
+ /* if chunk will exceed block limit */
+ if (chunk > space) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
+ "larger than space (%d) left in block: copy "
+ "only remaining space, and we are done\n",
+ chunk, space);
+ /* block is filled, so there is no extension */
+ *e_pointer |= 0x01;
+ /* fill only space */
+ memcpy(data, tbf->llc_frame + tbf->llc_index, space);
+ /* incement index */
+ tbf->llc_index += space;
+ /* return data block as message */
+ break;
+ }
+ /* if FINAL chunk would fit precisely in space left */
+ if (chunk == space && llist_empty(&tbf->llc_queue)) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
+ "would exactly fit into space (%d): because "
+ "this is a final block, we don't add length "
+ "header, and we are done\n", chunk, space);
+ LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for "
+ "TBF=%d that fits precisely in last block: "
+ "len=%d\n", tbf->tfi, tbf->llc_length);
+ gprs_rlcmac_debug_bw(tbf, tbf->llc_length);
+ /* block is filled, so there is no extension */
+ *e_pointer |= 0x01;
+ /* fill space */
+ memcpy(data, tbf->llc_frame + tbf->llc_index, space);
+ /* reset LLC frame */
+ tbf->llc_index = tbf->llc_length = 0;
+ /* final block */
+ rh->fbi = 1; /* we indicate final block */
+ tbf_new_state(tbf, GPRS_RLCMAC_FINISHED);
+ /* return data block as message */
+ break;
+ }
+ /* if chunk would fit exactly in space left */
+ if (chunk == space) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
+ "would exactly fit into space (%d): add length "
+ "header with LI=0, to make frame extend to "
+ "next block, and we are done\n", chunk, space);
+ /* make space for delimiter */
+ if (delimiter != data)
+ memcpy(delimiter + 1, delimiter,
+ data - delimiter);
+ data++;
+ space--;
+ /* add LI with 0 length */
+ li = (struct rlc_li_field *)delimiter;
+ li->e = 1; /* not more extension */
+ li->m = 0; /* shall be set to 0, in case of li = 0 */
+ li->li = 0; /* chunk fills the complete space */
+ // no need to set e_pointer nor increase delimiter
+ /* fill only space, which is 1 octet less than chunk */
+ memcpy(data, tbf->llc_frame + tbf->llc_index, space);
+ /* incement index */
+ tbf->llc_index += space;
+ /* return data block as message */
+ break;
+ }
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d is less "
+ "than remaining space (%d): add length header to "
+ "to delimit LLC frame\n", chunk, space);
+ /* the LLC frame chunk ends in this block */
+ /* make space for delimiter */
+ if (delimiter != data)
+ memcpy(delimiter + 1, delimiter, data - delimiter);
+ data++;
+ space--;
+ /* add LI to delimit frame */
+ li = (struct rlc_li_field *)delimiter;
+ li->e = 0; /* Extension bit, maybe set later */
+ li->m = 0; /* will be set later, if there is more LLC data */
+ li->li = chunk; /* length of chunk */
+ e_pointer = delimiter; /* points to E of current delimiter */
+ delimiter++;
+ /* copy (rest of) LLC frame to space */
+ memcpy(data, tbf->llc_frame + tbf->llc_index, chunk);
+ data += chunk;
+ space -= chunk;
+ LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for TBF=%d: "
+ "len=%d\n", tbf->tfi, tbf->llc_length);
+ gprs_rlcmac_debug_bw(tbf, tbf->llc_length);
+ /* reset LLC frame */
+ tbf->llc_index = tbf->llc_length = 0;
+ /* dequeue next LLC frame, if any */
+ msg = llc_dequeue(tbf);
+ if (msg) {
+ LOGP(DRLCMACDL, LOGL_INFO, "- Dequeue next LLC for "
+ "TBF=%d (len=%d)\n", tbf->tfi, msg->len);
+ memcpy(tbf->llc_frame, msg->data, msg->len);
+ tbf->llc_length = msg->len;
+ msgb_free(msg);
+ }
+ /* if we have more data and we have space left */
+ if (space > 0 && tbf->llc_length) {
+ li->m = 1; /* we indicate more frames to follow */
+ continue;
+ }
+ /* if we don't have more LLC frames */
+ if (!tbf->llc_length) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we "
+ "done.\n");
+ li->e = 1; /* we cannot extend */
+ rh->fbi = 1; /* we indicate final block */
+ tbf->dir.dl.tx_counter = POLL_ACK_AFTER_FRAMES + 1;
+ /* + 1 indicates: first final ack */
+ tbf_new_state(tbf, GPRS_RLCMAC_FINISHED);
+ break;
+ }
+ /* we have no space left */
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- No space left, so we are "
+ "done.\n");
+ li->e = 1; /* we cannot extend */
+ break;
+ }
+ LOGP(DRLCMACDL, LOGL_DEBUG, "data block: %s\n",
+ osmo_hexdump(tbf->rlc_block[index], block_length));
+ tbf->rlc_block_len[index] = block_length;
+ /* raise send state and set ack state array */
+ tbf->dir.dl.v_b[index] = 'U'; /* unacked */
+ tbf->dir.dl.v_s = (tbf->dir.dl.v_s + 1) & mod_sns; /* inc send state */
+
+tx_block:
+ /* from this point on, new block is sent or old block is resent */
+
+ /* get data and header from current block */
+ data = tbf->rlc_block[index];
+ len = tbf->rlc_block_len[index];
+ rh = (struct rlc_dl_header *)data;
+
+ /* Clear Polling, if still set in history buffer */
+ rh->s_p = 0;
+
+ /* poll after POLL_ACK_AFTER_FRAMES frames, or when final block is tx.
+ */
+ if (tbf->dir.dl.tx_counter >= POLL_ACK_AFTER_FRAMES) {
+ if (tbf->dir.dl.tx_counter > POLL_ACK_AFTER_FRAMES) {
+ /* if rx_counter is POLL_ACK_AFTER_FRAMES + 1, this
+ * indicates: poll caused by final ack. */
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
+ "polling, because final block sent.\n");
+ } else {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
+ "polling, because %d blocks sent.\n",
+ POLL_ACK_AFTER_FRAMES);
+ }
+ tbf->dir.dl.tx_counter = 0;
+ /* scheduling not possible, because: */
+ if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE)
+ LOGP(DRLCMAC, LOGL_DEBUG, "Polling is already "
+ "sheduled for TBF=%d, so we must wait for "
+ "requesting downlink ack\n", tbf->tfi);
+ else if (tbf->control_ts != ts)
+ LOGP(DRLCMAC, LOGL_DEBUG, "Polling cannot be "
+ "sheduled in this TS %d, waiting for "
+ "TS %d\n", ts, tbf->control_ts);
+ else {
+ LOGP(DRLCMAC, LOGL_DEBUG, "Polling sheduled in this "
+ "TS %d\n", ts);
+ /* start timer whenever we send the final block */
+ if (rh->fbi == 1)
+ tbf_timer_start(tbf, 3191, bts->t3191, 0);
+
+ /* schedule polling */
+ tbf->poll_state = GPRS_RLCMAC_POLL_SCHED;
+ tbf->poll_fn = (fn + 13) % 2715648;
+
+ /* set polling in header */
+ rh->rrbp = 0; /* N+13 */
+ rh->s_p = 1; /* Polling */
+
+ /* Increment TX-counter */
+ tbf->dir.dl.tx_counter++;
+ }
+ } else {
+ /* Increment TX-counter */
+ tbf->dir.dl.tx_counter++;
+ }
+
+ /* return data block as message */
+ dl_msg = msgb_alloc(len, "rlcmac_dl_data");
+ if (!dl_msg)
+ return NULL;
+ memcpy(msgb_put(dl_msg, len), data, len);
+
+ return dl_msg;
+}
+
+int gprs_rlcmac_downlink_ack(struct gprs_rlcmac_tbf *tbf, uint8_t final,
+ uint8_t ssn, uint8_t *rbb)
+{
+ char show_rbb[65], show_v_b[RLC_MAX_SNS + 1];
+ uint16_t mod_sns = tbf->sns - 1;
+ uint16_t mod_sns_half = (tbf->sns >> 1) - 1;
+ int i; /* must be signed */
+ int16_t dist; /* must be signed */
+ uint8_t bit;
+ uint16_t bsn;
+ struct msgb *msg;
+
+ LOGP(DRLCMACDL, LOGL_DEBUG, "TBF=%d downlink acknowledge\n",
+ tbf->tfi);
+
+ if (!final) {
+ /* show received array in debug (bit 64..1) */
+ for (i = 63; i >= 0; i--) {
+ bit = (rbb[i >> 3] >> (7 - (i&7))) & 1;
+ show_rbb[i] = (bit) ? '1' : 'o';
+ }
+ show_rbb[64] = '\0';
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- ack: (BSN=%d)\"%s\""
+ "(BSN=%d) 1=ACK o=NACK\n", (ssn - 64) & mod_sns,
+ show_rbb, (ssn - 1) & mod_sns);
+
+ /* apply received array to receive state (SSN-64..SSN-1) */
+ /* calculate distance of ssn from V(S) */
+ dist = (tbf->dir.dl.v_s - ssn) & mod_sns;
+ /* check if distance is less than distance V(A)..V(S) */
+ if (dist < ((tbf->dir.dl.v_s - tbf->dir.dl.v_a) & mod_sns)) {
+ /* SSN - 1 is in range V(A)..V(S)-1 */
+ for (i = 63, bsn = (ssn - 1) & mod_sns;
+ i >= 0 && bsn != ((tbf->dir.dl.v_a - 1) & mod_sns);
+ i--, bsn = (bsn - 1) & mod_sns) {
+ bit = (rbb[i >> 3] >> (7 - (i&7))) & 1;
+ if (bit) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- got "
+ "ack for BSN=%d\n", bsn);
+ tbf->dir.dl.v_b[bsn & mod_sns_half]
+ = 'A';
+ } else {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- got "
+ "NACK for BSN=%d\n", bsn);
+ tbf->dir.dl.v_b[bsn & mod_sns_half]
+ = 'N';
+ }
+ }
+ } else {
+ /* this might happpen, if the downlink assignment
+ * was not received by ms and the ack refers
+ * to previous TBF
+ * FIXME: we should implement polling for
+ * control ack!*/
+ LOGP(DRLCMACDL, LOGL_NOTICE, "- ack range is out of "
+ "V(A)..V(S) range (DL TBF=%d) Free TFB!\n",
+ tbf->tfi);
+ return 1; /* indicate to free TBF */
+ }
+
+ /* raise V(A), if possible */
+ for (i = 0, bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s;
+ i++, bsn = (bsn + 1) & mod_sns) {
+ if (tbf->dir.dl.v_b[bsn & mod_sns_half] == 'A') {
+ tbf->dir.dl.v_b[bsn & mod_sns_half] = 'I';
+ /* mark invalid */
+ tbf->dir.dl.v_a = (tbf->dir.dl.v_a + 1)
+ & mod_sns;
+ } else
+ break;
+ }
+
+ /* show receive state array in debug (V(A)..V(S)-1) */
+ for (i = 0, bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s;
+ i++, bsn = (bsn + 1) & mod_sns) {
+ show_v_b[i] = tbf->dir.dl.v_b[bsn & mod_sns_half];
+ if (show_v_b[i] == 0)
+ show_v_b[i] = ' ';
+ }
+ show_v_b[i] = '\0';
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- V(B): (V(A)=%d)\"%s\""
+ "(V(S)-1=%d) A=Acked N=Nacked U=Unacked "
+ "X=Resend-Unacked\n", tbf->dir.dl.v_a, show_v_b,
+ (tbf->dir.dl.v_s - 1) & mod_sns);
+
+ if (tbf->state == GPRS_RLCMAC_FINISHED
+ && tbf->dir.dl.v_s == tbf->dir.dl.v_a) {
+ LOGP(DRLCMACDL, LOGL_NOTICE, "Received final block, "
+ "but without final ack inidcation\n");
+ } else
+ return 0;
+ } else
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Final ACK received.\n");
+
+ /* check for LLC PDU in the LLC Queue */
+ msg = llc_dequeue(tbf);
+ if (!msg) {
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+
+ /* no message, start T3193, change state to RELEASE */
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- No new message, so we "
+ "release.\n");
+ /* start T3193 */
+ tbf_timer_start(tbf, 3193, bts->t3193_msec / 1000,
+ bts->t3193_msec & 1000);
+ tbf_new_state(tbf, GPRS_RLCMAC_WAIT_RELEASE);
+
+ return 0;
+ }
+ memcpy(tbf->llc_frame, msg->data, msg->len);
+ tbf->llc_length = msg->len;
+ msgb_free(msg);
+
+ /* we have a message, so we trigger downlink assignment, and there
+ * set the state to ASSIGN. also we set old_downlink, because we
+ * re-use this tbf. */
+ LOGP(DRLCMAC, LOGL_DEBUG, "Trigger dowlink assignment on PACCH, "
+ "because another LLC PDU has arrived in between\n");
+ memset(&tbf->dir.dl, 0, sizeof(tbf->dir.dl)); /* reset RLC states */
+ tbf_update(tbf);
+ gprs_rlcmac_trigger_downlink_assignment(tbf, tbf, NULL);
+
+ return 0;
+}
+
+
+struct msgb *gprs_rlcmac_send_packet_downlink_assignment(
+ struct gprs_rlcmac_tbf *tbf, uint32_t fn)
+{
+ struct msgb *msg;
+ struct gprs_rlcmac_tbf *new_tbf;
+
+#if POLLING_ASSIGNMENT == 1
+ if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "Polling is already "
+ "sheduled for TBF=%d, so we must wait for downlink "
+ "assignment...\n", tbf->tfi);
+ return NULL;
+ }
+#endif
+
+ /* on uplink TBF we get the downlink TBF to be assigned. */
+ if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
+ /* be sure to check first, if contention resolution is done,
+ * otherwise we cannot send the assignment yet */
+ if (!tbf->dir.ul.contention_resolution_done) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "Cannot assign DL TBF now, "
+ "because contention resolution is not "
+ "finished.\n");
+ return NULL;
+ }
+ new_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_DL_TBF);
+ } else
+ new_tbf = tbf;
+ if (!new_tbf) {
+ LOGP(DRLCMACDL, LOGL_ERROR, "We have a schedule for downlink "
+ "assignment at uplink TBF=%d, but there is no downlink "
+ "TBF\n", tbf->tfi);
+ tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
+ return NULL;
+ }
+
+ LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Downlink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli);
+ msg = write_packet_downlink_assignment(tbf->tfi,
+ (tbf->direction == GPRS_RLCMAC_DL_TBF), new_tbf,
+ POLLING_ASSIGNMENT);
+ if (!msg)
+ return NULL;
+
+#if POLLING_ASSIGNMENT == 1
+ tbf->poll_state = GPRS_RLCMAC_POLL_SCHED;
+ tbf->poll_fn = (fn + 13) % 2715648;
+ tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_WAIT_ACK;
+#else
+ tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
+ tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW);
+ tbf_assign_control_ts(new_tbf);
+#endif
+
+ return msg;
+}
+
+static void gprs_rlcmac_downlink_assignment(struct gprs_rlcmac_tbf *tbf,
+ uint8_t poll, char *imsi)
+{
+ uint8_t imm_ass[23];
+ int rc;
+
+ LOGP(DRLCMAC, LOGL_INFO, "TX: START TFI: %u TLLI: 0x%08x Immediate Assignment Downlink (PCH)\n", tbf->tfi, tbf->tlli);
+ /* use request reference that has maximum distance to current time,
+ * so the assignment will not conflict with possible RACH requests. */
+ rc = write_immediate_assignment_downlink(imm_ass, 125, (tbf->pdch[tbf->first_ts]->last_rts_fn + 21216) % 2715648, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, tbf->tlli, poll, tbf->poll_fn);
+ if (rc < 0)
+ return;
+
+ pcu_l1if_tx_pch(imm_ass, imsi);
+}
+
+/* depending on the current TBF, we assign on PACCH or AGCH */
+void gprs_rlcmac_trigger_downlink_assignment(struct gprs_rlcmac_tbf *tbf,
+ struct gprs_rlcmac_tbf *old_tbf, char *imsi)
+{
+#ifdef DEBUG_DL_ASS_IDLE
+ strncpy(debug_imsi, imsi);
+ LOGP(DRLCMAC, LOGL_ERROR, "**** DEBUGGING DOWNLINK ASSIGNMENT ****\n");
+#endif
+
+ /* stop pending timer */
+ tbf_timer_stop(tbf);
+
+ /* check for downlink tbf: */
+ if (old_tbf) {
+#ifdef DEBUG_DL_ASS_IDLE
+ LOGP(DRLCMAC, LOGL_ERROR, "We must wait for current TBF to be "
+ "released.\n");
+ /* wait one second until assignment */
+ tbf_timer_start(tbf, 1234, 1,0);
+#else
+ LOGP(DRLCMAC, LOGL_DEBUG, "Send dowlink assignment on "
+ "PACCH, because %s TBF=%d exists for TLLI=0x%08x\n",
+ (old_tbf->direction == GPRS_RLCMAC_UL_TBF)
+ ? "UL" : "DL", old_tbf->tfi, old_tbf->tlli);
+ old_tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_SEND_ASS;
+ /* use TA from old TBF */
+ tbf->ta = old_tbf->ta;
+ /* change state */
+ tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN);
+#endif
+ } else {
+ LOGP(DRLCMAC, LOGL_DEBUG, "Send dowlink assignment for TBF=%d on PCH, no TBF exist (IMSI=%s)\n", tbf->tfi, imsi);
+ if (!imsi || strlen(imsi) < 3) {
+ LOGP(DRLCMAC, LOGL_ERROR, "No valid IMSI!\n");
+ return;
+ }
+ /* change state */
+ tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN);
+ /* send immediate assignment */
+ gprs_rlcmac_downlink_assignment(tbf, 0, imsi);
+ /* send immediate assignment */
+ gprs_rlcmac_downlink_assignment(tbf, 0, imsi);
+ /* start timer */
+ tbf_timer_start(tbf, 0, Tassign_agch);
+ }
+ }
+