764 lines
27 KiB
C
764 lines
27 KiB
C
/* Paging helper and manager.... */
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/* (C) 2009,2013 by Holger Hans Peter Freyther <zecke@selfish.org>
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/*
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* Relevant specs:
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* 12.21:
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* - 9.4.12 for CCCH Local Threshold
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*
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* 05.58:
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* - 8.5.2 CCCH Load indication
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* - 9.3.15 Paging Load
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*
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* Approach:
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* - Send paging command to subscriber
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* - On Channel Request we will remember the reason
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* - After the ACK we will request the identity
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* - Then we will send assign the gsm_subscriber and
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* - and call a callback
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <osmocom/core/talloc.h>
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#include <osmocom/core/tdef.h>
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#include <osmocom/gsm/gsm48.h>
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#include <osmocom/gsm/gsm0502.h>
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#include <osmocom/bsc/bsc_subscriber.h>
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#include <osmocom/bsc/paging.h>
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#include <osmocom/bsc/debug.h>
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#include <osmocom/bsc/signal.h>
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#include <osmocom/bsc/abis_rsl.h>
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#include <osmocom/bsc/gsm_data.h>
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#include <osmocom/bsc/chan_alloc.h>
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#include <osmocom/bsc/gsm_08_08.h>
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#include <osmocom/bsc/gsm_04_08_rr.h>
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#include <osmocom/bsc/bsc_subscr_conn_fsm.h>
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#include <osmocom/bsc/bts.h>
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#include <osmocom/bsc/bsc_stats.h>
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void *tall_paging_ctx = NULL;
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/* How many paging requests to Tx on RSL at max before going back to main loop */
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#define MAX_PAGE_REQ_PER_ITER 10
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#define MAX_TX_DELAY_TIME_SEC 60
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/* How often to attempt sending new paging requests (initial, not retrans): 250ms */
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static const struct timespec initial_period = {
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.tv_sec = 0,
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.tv_nsec = 250 * 1000 * 1000,
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};
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/* Minimum period between retransmits of paging req to a subscriber: 500ms */
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static const struct timespec retrans_period = {
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.tv_sec = 0,
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.tv_nsec = 500 * 1000 * 1000,
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};
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/* If no CCCH Lod Ind is received before this time period, the BTS is considered
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* to have stopped sending CCCH Load Indication, probaby due to being under Load
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* Threshold: */
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#define bts_no_ccch_load_ind_timeout_sec(bts) ((bts)->ccch_load_ind_period * 2)
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/*
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* Kill one paging request update the internal list...
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*/
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static void paging_remove_request(struct gsm_bts_paging_state *paging_bts,
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struct gsm_paging_request *to_be_deleted)
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{
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to_be_deleted->bsub->active_paging_requests--;
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osmo_timer_del(&to_be_deleted->T3113);
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llist_del(&to_be_deleted->entry);
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paging_bts->pending_requests_len--;
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bsc_subscr_put(to_be_deleted->bsub, BSUB_USE_PAGING_REQUEST);
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talloc_free(to_be_deleted);
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if (llist_empty(&paging_bts->pending_requests))
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osmo_timer_del(&paging_bts->work_timer);
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}
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static void page_ms(struct gsm_paging_request *request)
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{
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unsigned int page_group;
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struct gsm_bts *bts = request->bts;
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struct osmo_mobile_identity mi;
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log_set_context(LOG_CTX_BSC_SUBSCR, request->bsub);
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LOG_PAGING_BTS(request, bts, DPAG, LOGL_INFO,
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"Going to send paging command for ch. type %d (attempt %d)\n",
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request->chan_type, request->attempts);
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if (request->bsub->tmsi == GSM_RESERVED_TMSI) {
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mi = (struct osmo_mobile_identity){
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.type = GSM_MI_TYPE_IMSI,
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};
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OSMO_STRLCPY_ARRAY(mi.imsi, request->bsub->imsi);
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} else {
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mi = (struct osmo_mobile_identity){
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.type = GSM_MI_TYPE_TMSI,
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.tmsi = request->bsub->tmsi,
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};
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}
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page_group = gsm0502_calc_paging_group(&bts->si_common.chan_desc,
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str_to_imsi(request->bsub->imsi));
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rsl_paging_cmd(bts, page_group, &mi, request->chan_type, false);
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log_set_context(LOG_CTX_BSC_SUBSCR, NULL);
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}
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static void paging_handle_pending_requests(struct gsm_bts_paging_state *paging_bts);
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static void paging_schedule_if_needed(struct gsm_bts_paging_state *paging_bts)
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{
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/* paging_handle_pending_requests() will schedule work_timer if work
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* needs to be partitioned in several iterations. */
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if (!osmo_timer_pending(&paging_bts->work_timer))
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paging_handle_pending_requests(paging_bts);
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}
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static void paging_give_credit(void *data)
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{
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struct gsm_bts_paging_state *paging_bts_st = data;
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struct gsm_bts *bts = paging_bts_st->bts;
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unsigned int load_ind_timeout = bts_no_ccch_load_ind_timeout_sec(bts);
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uint16_t estimated_slots = paging_estimate_available_slots(bts, load_ind_timeout);
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LOG_BTS(bts, DPAG, LOGL_INFO,
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"Timeout waiting for CCCH Load Indication, assuming BTS is below Load Threshold (available_slots %u -> %u)\n",
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paging_bts_st->available_slots, estimated_slots);
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paging_bts_st->available_slots = estimated_slots;
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paging_schedule_if_needed(paging_bts_st);
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osmo_timer_schedule(&bts->paging.credit_timer, load_ind_timeout, 0);
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}
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/*! count the number of free channels for given RSL channel type required
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* \param[in] BTS on which we shall count
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* \param[in] rsl_type the RSL channel needed type
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* \returns number of free channels matching \a rsl_type in \a bts */
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static int can_send_pag_req(struct gsm_bts *bts, int rsl_type)
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{
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struct pchan_load pl;
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int count;
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memset(&pl, 0, sizeof(pl));
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bts_chan_load(&pl, bts);
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switch (rsl_type) {
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case RSL_CHANNEED_TCH_F:
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case RSL_CHANNEED_TCH_ForH:
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goto count_tch;
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break;
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case RSL_CHANNEED_SDCCH:
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goto count_sdcch;
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break;
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case RSL_CHANNEED_ANY:
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default:
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if (bts->network->pag_any_tch)
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goto count_tch;
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else
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goto count_sdcch;
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break;
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}
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return 0;
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/* could available SDCCH */
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count_sdcch:
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count = 0;
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count += pl.pchan[GSM_PCHAN_SDCCH8_SACCH8C].total
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- pl.pchan[GSM_PCHAN_SDCCH8_SACCH8C].used;
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count += pl.pchan[GSM_PCHAN_CCCH_SDCCH4].total
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- pl.pchan[GSM_PCHAN_CCCH_SDCCH4].used;
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return bts->paging.free_chans_need > count;
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count_tch:
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count = 0;
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count += pl.pchan[GSM_PCHAN_TCH_F].total
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- pl.pchan[GSM_PCHAN_TCH_F].used;
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if (bts->network->neci)
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count += pl.pchan[GSM_PCHAN_TCH_H].total
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- pl.pchan[GSM_PCHAN_TCH_H].used;
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return bts->paging.free_chans_need > count;
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}
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/*
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* This is kicked by the periodic PAGING LOAD Indicator
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* coming from abis_rsl.c
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*
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* We attempt to iterate once over the list of items but
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* only upto available_slots.
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*/
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static void paging_handle_pending_requests(struct gsm_bts_paging_state *paging_bts)
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{
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struct gsm_paging_request *request, *initial_request;
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unsigned int num_paged = 0;
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struct gsm_bts *bts = paging_bts->bts;
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struct timespec now, retrans_ts;
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/*
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* Determine if the pending_requests list is empty and
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* return then.
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*/
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if (llist_empty(&paging_bts->pending_requests)) {
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/* since the list is empty, no need to reschedule the timer */
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return;
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}
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osmo_clock_gettime(CLOCK_MONOTONIC, &now);
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paging_bts->last_sched_ts = now;
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/* do while loop: Try send at most first MAX_PAGE_REQ_PER_ITER paging
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* requests (or before if there are no more available slots). Since
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* transmitted requests are re-appended at the end of the list, we check
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* until we find the first req again, in order to avoid retransmitting
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* repeated requests until next time paging is scheduled. */
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initial_request = llist_first_entry(&paging_bts->pending_requests,
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struct gsm_paging_request, entry);
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request = initial_request;
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do {
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/* We run out of available slots. Wait until next CCCH Load Ind
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* arrives or credit_timer triggers to keep processing requests.
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*/
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if (paging_bts->available_slots == 0) {
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LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO,
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"Paging delayed: waiting for available slots at BTS\n");
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return;
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}
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/* we need to determine the number of free channels */
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if (paging_bts->free_chans_need != -1 &&
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can_send_pag_req(request->bts, request->chan_type) != 0) {
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LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_INFO,
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"Paging delayed: not enough free channels (<%d)\n",
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paging_bts->free_chans_need);
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goto sched_next_iter;
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}
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/* If we reach around back of the queue (retransmitions), check
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* if time to retransmit has elapsed. Otherwise, wait until its
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* time to retransmit. */
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if (request->attempts > 0) {
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timespecadd(&request->last_attempt_ts, &retrans_period, &retrans_ts);
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if (timespeccmp(&now, &retrans_ts, <)) {
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struct timespec tdiff;
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timespecsub(&retrans_ts, &now, &tdiff);
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LOG_PAGING_BTS(request, request->bts, DPAG, LOGL_DEBUG,
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"Paging delayed: retransmission happens in %lld.%06lds\n",
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(long long)tdiff.tv_sec, tdiff.tv_nsec / 1000);
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osmo_timer_schedule(&paging_bts->work_timer, tdiff.tv_sec, tdiff.tv_nsec / 1000);
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return;
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}
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}
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/* handle the paging request now */
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page_ms(request);
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paging_bts->available_slots--;
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request->last_attempt_ts = now;
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request->attempts++;
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num_paged++;
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llist_del(&request->entry);
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llist_add_tail(&request->entry, &paging_bts->pending_requests);
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request = llist_first_entry(&paging_bts->pending_requests,
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struct gsm_paging_request, entry);
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} while (request != initial_request && num_paged < MAX_PAGE_REQ_PER_ITER);
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/* Once done iterating, prepare next scheduling: */
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sched_next_iter:
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LOG_BTS(bts, DPAG, LOGL_DEBUG, "Paged %u subscribers during last iteration. "
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"Scheduling next batch in %lld.%06lds (available_slots=%u)\n",
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num_paged, (long long)initial_period.tv_sec, initial_period.tv_nsec / 1000,
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paging_bts->available_slots);
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osmo_timer_schedule(&paging_bts->work_timer, initial_period.tv_sec, initial_period.tv_nsec / 1000);
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}
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static void paging_worker(void *data)
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{
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struct gsm_bts_paging_state *paging_bts = data;
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paging_handle_pending_requests(paging_bts);
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}
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/*! initialize the bts paging state, if it hasn't been initialized yet */
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void paging_init(struct gsm_bts *bts)
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{
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bts->paging.bts = bts;
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bts->paging.free_chans_need = -1;
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bts->paging.available_slots = 0;
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INIT_LLIST_HEAD(&bts->paging.pending_requests);
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osmo_timer_setup(&bts->paging.work_timer, paging_worker, &bts->paging);
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osmo_timer_setup(&bts->paging.credit_timer, paging_give_credit, &bts->paging);
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}
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/* Called upon the bts struct being freed */
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void paging_destructor(struct gsm_bts *bts)
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{
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paging_flush_bts(bts, NULL);
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osmo_timer_del(&bts->paging.credit_timer);
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osmo_timer_del(&bts->paging.work_timer);
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}
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/*! Call-back once T3113 (paging timeout) expires for given paging_request */
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static void paging_T3113_expired(void *data)
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{
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struct gsm_paging_request *req = (struct gsm_paging_request *)data;
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log_set_context(LOG_CTX_BSC_SUBSCR, req->bsub);
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LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_INFO, "T3113 expired\n");
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/* must be destroyed before calling cbfn, to prevent double free */
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rate_ctr_inc(rate_ctr_group_get_ctr(req->bts->bts_ctrs, BTS_CTR_PAGING_EXPIRED));
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/* If last BTS paging times out (active_paging_requests will be
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* decremented in paging_remove_request below): */
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if (req->bsub->active_paging_requests == 1)
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rate_ctr_inc(rate_ctr_group_get_ctr(bsc_gsmnet->bsc_ctrs, BSC_CTR_PAGING_EXPIRED));
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/* destroy it now. Do not access req afterwards */
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paging_remove_request(&req->bts->paging, req);
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log_set_context(LOG_CTX_BSC_SUBSCR, NULL);
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}
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#define GSM51_MFRAME_DURATION_us (51 * GSM_TDMA_FN_DURATION_uS) /* 235365 us */
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static unsigned int paging_estimate_delay_us(struct gsm_bts *bts, unsigned int num_reqs,
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unsigned int num_reqs_same_pgroup);
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static unsigned int calculate_timer_3113(struct gsm_paging_request *req, unsigned int reqs_before,
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unsigned int reqs_before_same_pgroup)
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{
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unsigned int to_us, estimated_to, to;
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struct gsm_bts *bts = req->bts;
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struct osmo_tdef *d = osmo_tdef_get_entry(bts->network->T_defs, 3113);
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unsigned int rach_max_trans, rach_tx_integer, bs_pa_mfrms;
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/* Note: d should always contain a valid pointer since all timers,
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* including 3113 are statically pre-defined in
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* struct osmo_tdef gsm_network_T_defs. */
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OSMO_ASSERT(d);
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if (!bts->T3113_dynamic) {
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to = d->val;
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goto ret;
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}
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/* MFRMS defines repeat interval of paging messages for MSs that belong
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* to same paging group across multiple 51 frame multiframes.
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* MAXTRANS defines maximum number of RACH retransmissions, spread over
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* TXINTEGER slots.
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*/
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rach_max_trans = rach_max_trans_raw2val(bts->si_common.rach_control.max_trans);
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rach_tx_integer = rach_tx_integer_raw2val(bts->si_common.rach_control.tx_integer);
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bs_pa_mfrms = (bts->si_common.chan_desc.bs_pa_mfrms + 2);
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to_us = GSM51_MFRAME_DURATION_us * bs_pa_mfrms +
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GSM_TDMA_FN_DURATION_uS * rach_tx_integer * rach_max_trans;
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/* Now add some extra time based on how many requests need to be transmitted before this one: */
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to_us += paging_estimate_delay_us(bts, reqs_before, reqs_before_same_pgroup);
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/* ceiling in seconds + extra time */
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estimated_to = (to_us + 999999) / 1000000 + d->val;
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/* upper bound: 60s (OS#5553) */
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if (estimated_to > MAX_TX_DELAY_TIME_SEC)
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to = MAX_TX_DELAY_TIME_SEC;
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else
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to = estimated_to;
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LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG,
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"Paging request: T3113 expires in %u seconds (estimated %u)\n",
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to, estimated_to);
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ret:
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osmo_stat_item_set(osmo_stat_item_group_get_item(bts->bts_statg, BTS_STAT_T3113), to);
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return to;
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}
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/*! Start paging + paging timer for given subscriber on given BTS
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* \param bts BTS on which to page
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* \param[in] bsub subscriber we want to page
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* \param[in] type type of radio channel we're requirign
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* \param[in] msc MSC which has issue this paging
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* \returns 0 on success, negative on error */
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static int _paging_request(const struct bsc_paging_params *params, struct gsm_bts *bts)
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{
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struct gsm_bts_paging_state *bts_entry = &bts->paging;
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struct gsm_paging_request *req, *last_initial_req = NULL;
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unsigned int t3113_timeout_s;
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unsigned int reqs_before = 0, reqs_before_same_pgroup = 0;
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uint8_t pgroup = gsm0502_calc_paging_group(&bts->si_common.chan_desc,
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str_to_imsi(params->bsub->imsi));
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rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_ATTEMPTED));
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|
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/* don't try to queue more requests than we can realistically handle within MAX_TX_DELAY_TIME_SEC seconds */
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if (paging_pending_requests_nr(bts) > paging_estimate_available_slots(bts, MAX_TX_DELAY_TIME_SEC)) {
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rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_OVERLOAD));
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return -ENOSPC;
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}
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|
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/* Iterate list of pending requests to find if we already have one for
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* the given subscriber. While on it, find the last
|
|
* not-yet-ever-once-transmitted request; the new request will be added
|
|
* immediately after it, giving higher prio to initial transmissions
|
|
* (no retrans). This avoids new subscribers being paged to be delayed
|
|
* if the paging queue is full due to a lot of retranmissions.
|
|
* Retranmissions usually mean MS are not reachable/available, so the
|
|
* rationale here is to prioritize new subs which may be available. */
|
|
llist_for_each_entry(req, &bts_entry->pending_requests, entry) {
|
|
if (params->bsub == req->bsub) {
|
|
LOG_PAGING_BTS(params, bts, DPAG, LOGL_INFO, "Paging request already pending for this subscriber\n");
|
|
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_ALREADY));
|
|
return -EEXIST;
|
|
}
|
|
if (req->attempts == 0) {
|
|
last_initial_req = req;
|
|
reqs_before++;
|
|
if (req->pgroup == pgroup)
|
|
reqs_before_same_pgroup++;
|
|
} else if (last_initial_req == NULL) {
|
|
/* If no req with attempts=0 was found, we'll append to end of list, so keep counting. */
|
|
reqs_before++;
|
|
if (req->pgroup == pgroup)
|
|
reqs_before_same_pgroup++;
|
|
}
|
|
}
|
|
|
|
LOG_PAGING_BTS(params, bts, DPAG, LOGL_DEBUG, "Start paging\n");
|
|
params->bsub->active_paging_requests++;
|
|
req = talloc_zero(tall_paging_ctx, struct gsm_paging_request);
|
|
OSMO_ASSERT(req);
|
|
req->reason = params->reason;
|
|
req->bsub = params->bsub;
|
|
bsc_subscr_get(req->bsub, BSUB_USE_PAGING_REQUEST);
|
|
req->bts = bts;
|
|
req->chan_type = params->chan_needed;
|
|
req->pgroup = pgroup;
|
|
req->msc = params->msc;
|
|
osmo_timer_setup(&req->T3113, paging_T3113_expired, req);
|
|
|
|
bts_entry->pending_requests_len++;
|
|
/* there's no initial req (attempts==0), add to the start of the list */
|
|
if (last_initial_req == NULL)
|
|
llist_add(&req->entry, &bts_entry->pending_requests);
|
|
else/* Add in the middle of the list after last_initial_req */
|
|
__llist_add(&req->entry, &last_initial_req->entry, last_initial_req->entry.next);
|
|
|
|
t3113_timeout_s = calculate_timer_3113(req, reqs_before, reqs_before_same_pgroup);
|
|
osmo_timer_schedule(&req->T3113, t3113_timeout_s, 0);
|
|
|
|
/* Trigger scheduler if needed: */
|
|
if (!osmo_timer_pending(&bts_entry->work_timer)) {
|
|
paging_handle_pending_requests(bts_entry);
|
|
} else if (last_initial_req == NULL) {
|
|
/* Worker timer is armed -> there was already one req before
|
|
* last_initial_req is NULL -> There were no initial requests in
|
|
* the list, aka the timer is waiting for retransmition,
|
|
* which is a longer period.
|
|
* Let's recaculate the time to adapt it to initial_period: */
|
|
struct timespec now, elapsed, tdiff;
|
|
osmo_clock_gettime(CLOCK_MONOTONIC, &now);
|
|
timespecsub(&now, &bts_entry->last_sched_ts, &elapsed);
|
|
if (timespeccmp(&elapsed, &initial_period, <)) {
|
|
timespecsub(&initial_period, &elapsed, &tdiff);
|
|
} else {
|
|
tdiff = (struct timespec){.tv_sec = 0, .tv_nsec = 0 };
|
|
}
|
|
LOG_PAGING_BTS(req, req->bts, DPAG, LOGL_DEBUG,
|
|
"New req arrived: re-scheduling next batch in %lld.%06lds\n",
|
|
(long long)tdiff.tv_sec, tdiff.tv_nsec / 1000);
|
|
/* Avoid scheduling timer for short periods, run cb directly: */
|
|
if (tdiff.tv_sec == 0 && tdiff.tv_nsec < 5000)
|
|
paging_worker(bts_entry);
|
|
else
|
|
osmo_timer_schedule(&bts_entry->work_timer, tdiff.tv_sec, tdiff.tv_nsec / 1000);
|
|
} /* else: worker is already ongoing submitting initial requests, nothing do be done */
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Handle PAGING request from MSC for one (matching) BTS
|
|
* \param bts BTS on which to page
|
|
* \param[in] bsub subscriber we want to page
|
|
* \param[in] type type of radio channel we're requirign
|
|
* \param[in] msc MSC which has issue this paging
|
|
* returns 1 on success; 0 in case of error (e.g. TRX down) */
|
|
int paging_request_bts(const struct bsc_paging_params *params, struct gsm_bts *bts)
|
|
{
|
|
int rc;
|
|
|
|
/* skip all currently inactive TRX */
|
|
if (!trx_is_usable(bts->c0))
|
|
return 0;
|
|
|
|
/* Trigger paging, pass any error to the caller */
|
|
rc = _paging_request(params, bts);
|
|
if (rc < 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*! Stop paging a given subscriber on a given BTS.
|
|
* \param[out] returns the MSC that paged the subscriber, if any.
|
|
* \param[out] returns the reason for a pending paging, if any.
|
|
* \param[in] bts BTS which has received a paging response.
|
|
* \param[in] bsub subscriber.
|
|
* \returns number of pending pagings.
|
|
*/
|
|
static int paging_request_stop_bts(struct bsc_msc_data **msc_p, enum bsc_paging_reason *reason_p,
|
|
struct gsm_bts *bts, struct bsc_subscr *bsub)
|
|
{
|
|
struct gsm_bts_paging_state *bts_entry = &bts->paging;
|
|
struct gsm_paging_request *req, *req2;
|
|
|
|
*msc_p = NULL;
|
|
*reason_p = BSC_PAGING_NONE;
|
|
|
|
llist_for_each_entry_safe(req, req2, &bts_entry->pending_requests,
|
|
entry) {
|
|
if (req->bsub != bsub)
|
|
continue;
|
|
*msc_p = req->msc;
|
|
*reason_p = req->reason;
|
|
LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, "Stop paging\n");
|
|
paging_remove_request(&bts->paging, req);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Stop paging on all cells and return the MSC that paged (if any) and all pending paging reasons.
|
|
* \param[out] returns the MSC that paged the subscriber, if there was a pending request.
|
|
* \param[out] returns the ORed bitmask of all reasons of pending pagings.
|
|
* \param[in] bts BTS which has received a paging response
|
|
* \param[in] bsub subscriber
|
|
* \returns number of pending pagings.
|
|
*/
|
|
int paging_request_stop(struct bsc_msc_data **msc_p, enum bsc_paging_reason *reasons_p,
|
|
struct gsm_bts *bts, struct bsc_subscr *bsub)
|
|
{
|
|
struct gsm_bts *bts_i;
|
|
struct bsc_msc_data *paged_from_msc;
|
|
int count;
|
|
enum bsc_paging_reason reasons;
|
|
OSMO_ASSERT(bts);
|
|
|
|
count = paging_request_stop_bts(&paged_from_msc, &reasons, bts, bsub);
|
|
if (paged_from_msc) {
|
|
count++;
|
|
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_RESPONDED));
|
|
rate_ctr_inc(rate_ctr_group_get_ctr(bts->network->bsc_ctrs, BSC_CTR_PAGING_RESPONDED));
|
|
}
|
|
|
|
llist_for_each_entry(bts_i, &bsc_gsmnet->bts_list, list) {
|
|
struct bsc_msc_data *paged_from_msc2;
|
|
enum bsc_paging_reason reason2;
|
|
count += paging_request_stop_bts(&paged_from_msc2, &reason2, bts_i, bsub);
|
|
if (paged_from_msc2) {
|
|
reasons |= reason2;
|
|
if (!paged_from_msc) {
|
|
/* If this happened, it would be a bit weird: it means there was no Paging Request
|
|
* pending on the BTS that sent the Paging Reponse, but there *is* a Paging Request
|
|
* pending on a different BTS. But why not return an MSC when we found one. */
|
|
paged_from_msc = paged_from_msc2;
|
|
}
|
|
}
|
|
}
|
|
|
|
*msc_p = paged_from_msc;
|
|
*reasons_p = reasons;
|
|
|
|
return count;
|
|
}
|
|
|
|
/* Remove all paging requests, for specific reasons only. */
|
|
int paging_request_cancel(struct bsc_subscr *bsub, enum bsc_paging_reason reasons)
|
|
{
|
|
struct gsm_bts *bts;
|
|
int count = 0;
|
|
|
|
llist_for_each_entry(bts, &bsc_gsmnet->bts_list, list) {
|
|
struct gsm_paging_request *req, *req2;
|
|
|
|
llist_for_each_entry_safe(req, req2, &bts->paging.pending_requests, entry) {
|
|
if (req->bsub != bsub)
|
|
continue;
|
|
if (!(req->reason & reasons))
|
|
continue;
|
|
LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, "Cancel paging\n");
|
|
paging_remove_request(&bts->paging, req);
|
|
count++;
|
|
}
|
|
}
|
|
return count;
|
|
}
|
|
|
|
/*! Update the BTS paging buffer slots on given BTS */
|
|
void paging_update_buffer_space(struct gsm_bts *bts, uint16_t free_slots)
|
|
{
|
|
LOG_BTS(bts, DPAG, LOGL_DEBUG, "Rx CCCH Load Indication from BTS (available_slots %u -> %u)\n",
|
|
bts->paging.available_slots, free_slots);
|
|
bts->paging.available_slots = free_slots;
|
|
/* Re-arm credit_timer if needed */
|
|
if (trx_is_usable(bts->c0)) {
|
|
paging_schedule_if_needed(&bts->paging);
|
|
osmo_timer_schedule(&bts->paging.credit_timer,
|
|
bts_no_ccch_load_ind_timeout_sec(bts), 0);
|
|
}
|
|
}
|
|
|
|
/*! Count the number of pending paging requests on given BTS */
|
|
unsigned int paging_pending_requests_nr(struct gsm_bts *bts)
|
|
{
|
|
return bts->paging.pending_requests_len;
|
|
}
|
|
|
|
/*! Flush all paging requests at a given BTS for a given MSC (or NULL if all MSC should be flushed). */
|
|
void paging_flush_bts(struct gsm_bts *bts, struct bsc_msc_data *msc)
|
|
{
|
|
struct gsm_paging_request *req, *req2;
|
|
int num_cancelled = 0;
|
|
|
|
llist_for_each_entry_safe(req, req2, &bts->paging.pending_requests, entry) {
|
|
if (msc && req->msc != msc)
|
|
continue;
|
|
/* now give up the data structure */
|
|
LOG_PAGING_BTS(req, bts, DPAG, LOGL_DEBUG, "Stop paging (flush)\n");
|
|
paging_remove_request(&bts->paging, req);
|
|
num_cancelled++;
|
|
}
|
|
|
|
rate_ctr_add(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_CTR_PAGING_MSC_FLUSH), num_cancelled);
|
|
}
|
|
|
|
/*! Flush all paging requests issued by \a msc on any BTS in \a net */
|
|
void paging_flush_network(struct gsm_network *net, struct bsc_msc_data *msc)
|
|
{
|
|
struct gsm_bts *bts;
|
|
|
|
llist_for_each_entry(bts, &net->bts_list, list)
|
|
paging_flush_bts(bts, msc);
|
|
}
|
|
|
|
/*! Estimate available_slots credit over a time period, used when below CCCH Load Indication Threshold */
|
|
uint16_t paging_estimate_available_slots(struct gsm_bts *bts, unsigned int time_span_s)
|
|
{
|
|
unsigned int n_pag_blocks = gsm0502_get_n_pag_blocks(&bts->si_common.chan_desc);
|
|
uint16_t available_slots = n_pag_blocks * time_span_s * 1000000 / GSM51_MFRAME_DURATION_us;
|
|
LOG_BTS(bts, DPAG, LOGL_DEBUG, "Estimated %u paging available_slots over %u seconds\n",
|
|
available_slots, time_span_s);
|
|
return available_slots;
|
|
}
|
|
|
|
/*! Conservative estimate of time needed by BTS to schedule a number of paging
|
|
* requests (num_reqs), based on current load at the BSC queue (doesn't take into
|
|
* account BTs own buffer) */
|
|
static unsigned int paging_estimate_delay_us(struct gsm_bts *bts, unsigned int num_reqs,
|
|
unsigned int num_reqs_same_pgroup)
|
|
{
|
|
unsigned int n_pag_blocks, n_mframes, time_us = 0;
|
|
|
|
n_pag_blocks = gsm0502_get_n_pag_blocks(&bts->si_common.chan_desc);
|
|
|
|
/* First of all, we need to extend the timeout in relation to the amount
|
|
* of paging requests in the BSC queue. In here we don't care about the
|
|
* paging group, because they are mixed in the same queue. If we don't
|
|
* take this into account, it could happen that if lots of requests are
|
|
* received at the BSC (from MSC) around the same time, they could time
|
|
* out in the BSC queue before arriving at the BTS. We already account of
|
|
* same-paging-group ones further below, so don't take them into account
|
|
* here: */
|
|
unsigned int num_reqs_other_groups = num_reqs - num_reqs_same_pgroup;
|
|
time_us += ((num_reqs_other_groups * GSM51_MFRAME_DURATION_us) + (n_pag_blocks - 1)) / n_pag_blocks;
|
|
|
|
/* Now we extend the timeout based on the amount of requests of the same
|
|
* paging group before the present one: */
|
|
n_mframes = (num_reqs_same_pgroup + (n_pag_blocks - 1)) / n_pag_blocks;
|
|
time_us += n_mframes * GSM51_MFRAME_DURATION_us;
|
|
/* the multiframes are not consecutive for a paging group, let's add the spacing between: */
|
|
if (n_mframes > 1) {
|
|
unsigned int bs_pa_mfrms = (bts->si_common.chan_desc.bs_pa_mfrms + 2);
|
|
time_us += (n_mframes - 1) * bs_pa_mfrms * GSM51_MFRAME_DURATION_us;
|
|
}
|
|
return time_us;
|
|
}
|
|
|
|
/* Callback function to be called every time we receive a signal from NM */
|
|
static int nm_sig_cb(unsigned int subsys, unsigned int signal,
|
|
void *handler_data, void *signal_data)
|
|
{
|
|
struct nm_running_chg_signal_data *nsd;
|
|
struct gsm_bts *bts;
|
|
struct gsm_bts_trx *trx;
|
|
unsigned int load_ind_timeout;
|
|
|
|
if (signal != S_NM_RUNNING_CHG)
|
|
return 0;
|
|
|
|
nsd = signal_data;
|
|
bts = nsd->bts;
|
|
|
|
switch (nsd->obj_class) {
|
|
case NM_OC_RADIO_CARRIER:
|
|
trx = (struct gsm_bts_trx *)nsd->obj;
|
|
break;
|
|
case NM_OC_BASEB_TRANSC:
|
|
trx = gsm_bts_bb_trx_get_trx((struct gsm_bts_bb_trx *)nsd->obj);
|
|
break;
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
/* We only care about state changes of C0. */
|
|
if (trx != trx->bts->c0)
|
|
return 0;
|
|
|
|
if (nsd->running) {
|
|
if (trx_is_usable(trx)) {
|
|
LOG_BTS(bts, DPAG, LOGL_INFO, "C0 becomes available for paging\n");
|
|
/* Fill in initial credit */
|
|
load_ind_timeout = bts_no_ccch_load_ind_timeout_sec(bts);
|
|
bts->paging.available_slots = paging_estimate_available_slots(bts, load_ind_timeout);
|
|
/* Start scheduling credit_timer */
|
|
osmo_timer_schedule(&bts->paging.credit_timer,
|
|
bts_no_ccch_load_ind_timeout_sec(bts), 0);
|
|
/* work_timer will be started when new paging requests arrive. */
|
|
}
|
|
} else {
|
|
/* If credit timer was not pending it means C0 was already unavailable before (rcarrier||bbtransc) */
|
|
if (osmo_timer_pending(&bts->paging.credit_timer)) {
|
|
LOG_BTS(bts, DPAG, LOGL_INFO, "C0 becomes unavailable for paging\n");
|
|
/* Note: flushing will osmo_timer_del(&bts->paging.work_timer) when queue becomes empty */
|
|
paging_flush_bts(bts, NULL);
|
|
osmo_timer_del(&bts->paging.credit_timer);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* To be called once at startup of the process: */
|
|
void paging_global_init(void)
|
|
{
|
|
osmo_signal_register_handler(SS_NM, nm_sig_cb, NULL);
|
|
}
|