138 lines
3.0 KiB
C++
138 lines
3.0 KiB
C++
/*
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* ta.cpp timing advance handling
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* Copyright (C) 2012 Ivan Klyuchnikov
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* Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
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* Copyright (C) 2013 by Holger Hans Peter Freyther
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (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 General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <ta.h>
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#include <gprs_rlcmac.h>
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extern "C" {
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#include <osmocom/core/talloc.h>
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}
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#include <errno.h>
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extern void *tall_pcu_ctx;
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/*
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* timing advance memory
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*/
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/* enable to debug timing advance memory */
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//#define DEBUG_TA
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struct gprs_rlcmac_ta {
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struct llist_head list;
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uint32_t tlli;
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uint8_t ta;
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};
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TimingAdvance::TimingAdvance()
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: m_ta_len(0)
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{
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INIT_LLIST_HEAD(&m_ta_list);
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}
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/* remember timing advance of a given TLLI */
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int TimingAdvance::remember(uint32_t tlli, uint8_t ta)
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{
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struct gprs_rlcmac_ta *ta_entry;
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/* check for existing entry */
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llist_for_each_entry(ta_entry, &m_ta_list, list) {
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if (ta_entry->tlli == tlli) {
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#ifdef DEBUG_TA
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fprintf(stderr, "update %08x %d\n", tlli, ta);
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#endif
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ta_entry->ta = ta;
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/* relink to end of list */
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llist_del(&ta_entry->list);
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llist_add_tail(&ta_entry->list, &m_ta_list);
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return 0;
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}
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}
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#ifdef DEBUG_TA
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fprintf(stderr, "remember %08x %d\n", tlli, ta);
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#endif
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/* if list is full, remove oldest entry */
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if (m_ta_len == 30) {
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ta_entry = llist_entry(m_ta_list.next,
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struct gprs_rlcmac_ta, list);
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llist_del(&ta_entry->list);
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talloc_free(ta_entry);
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m_ta_len--;
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}
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/* create new TA entry */
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ta_entry = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ta);
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if (!ta_entry)
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return -ENOMEM;
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ta_entry->tlli = tlli;
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ta_entry->ta = ta;
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llist_add_tail(&ta_entry->list, &m_ta_list);
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m_ta_len++;
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return 0;
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}
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int TimingAdvance::recall(uint32_t tlli)
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{
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struct gprs_rlcmac_ta *ta_entry;
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uint8_t ta;
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llist_for_each_entry(ta_entry, &m_ta_list, list) {
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if (ta_entry->tlli == tlli) {
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ta = ta_entry->ta;
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#ifdef DEBUG_TA
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fprintf(stderr, "recall %08x %d\n", tlli, ta);
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#endif
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return ta;
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}
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}
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#ifdef DEBUG_TA
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fprintf(stderr, "no entry for %08x\n", tlli);
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#endif
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return -EINVAL;
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}
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int TimingAdvance::flush()
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{
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struct gprs_rlcmac_ta *ta_entry;
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int count = 0;
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while (!llist_empty(&m_ta_list)) {
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ta_entry = llist_entry(m_ta_list.next,
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struct gprs_rlcmac_ta, list);
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#ifdef DEBUG_TA
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fprintf(stderr, "flush entry %08x %d\n", ta_entry->tlli,
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ta_entry->ta);
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#endif
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llist_del(&ta_entry->list);
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talloc_free(ta_entry);
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count++;
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}
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m_ta_len = 0;
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return count;
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}
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