Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 1 | /* |
| 2 | * ta.cpp timing advance handling |
| 3 | * Copyright (C) 2012 Ivan Klyuchnikov |
| 4 | * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| 5 | * Copyright (C) 2013 by Holger Hans Peter Freyther |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version 2 |
| 10 | * of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 20 | */ |
| 21 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 22 | #include <ta.h> |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 23 | #include <gprs_rlcmac.h> |
| 24 | |
| 25 | extern "C" { |
| 26 | #include <osmocom/core/talloc.h> |
| 27 | } |
| 28 | |
| 29 | #include <errno.h> |
| 30 | |
| 31 | extern void *tall_pcu_ctx; |
| 32 | |
| 33 | /* |
| 34 | * timing advance memory |
| 35 | */ |
| 36 | |
| 37 | /* enable to debug timing advance memory */ |
| 38 | //#define DEBUG_TA |
| 39 | |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 40 | struct gprs_rlcmac_ta { |
| 41 | struct llist_head list; |
| 42 | uint32_t tlli; |
| 43 | uint8_t ta; |
| 44 | }; |
| 45 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 46 | TimingAdvance::TimingAdvance() |
| 47 | : m_ta_len(0) |
| 48 | { |
| 49 | INIT_LLIST_HEAD(&m_ta_list); |
| 50 | } |
| 51 | |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 52 | /* remember timing advance of a given TLLI */ |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 53 | int TimingAdvance::remember(uint32_t tlli, uint8_t ta) |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 54 | { |
| 55 | struct gprs_rlcmac_ta *ta_entry; |
| 56 | |
| 57 | /* check for existing entry */ |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 58 | llist_for_each_entry(ta_entry, &m_ta_list, list) { |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 59 | if (ta_entry->tlli == tlli) { |
| 60 | #ifdef DEBUG_TA |
| 61 | fprintf(stderr, "update %08x %d\n", tlli, ta); |
| 62 | #endif |
| 63 | ta_entry->ta = ta; |
| 64 | /* relink to end of list */ |
| 65 | llist_del(&ta_entry->list); |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 66 | llist_add_tail(&ta_entry->list, &m_ta_list); |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 67 | return 0; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | #ifdef DEBUG_TA |
| 72 | fprintf(stderr, "remember %08x %d\n", tlli, ta); |
| 73 | #endif |
| 74 | /* if list is full, remove oldest entry */ |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 75 | if (m_ta_len == 30) { |
| 76 | ta_entry = llist_entry(m_ta_list.next, |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 77 | struct gprs_rlcmac_ta, list); |
| 78 | llist_del(&ta_entry->list); |
| 79 | talloc_free(ta_entry); |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 80 | m_ta_len--; |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 81 | } |
| 82 | |
| 83 | /* create new TA entry */ |
| 84 | ta_entry = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ta); |
| 85 | if (!ta_entry) |
| 86 | return -ENOMEM; |
| 87 | |
| 88 | ta_entry->tlli = tlli; |
| 89 | ta_entry->ta = ta; |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 90 | llist_add_tail(&ta_entry->list, &m_ta_list); |
| 91 | m_ta_len++; |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 96 | int TimingAdvance::recall(uint32_t tlli) |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 97 | { |
| 98 | struct gprs_rlcmac_ta *ta_entry; |
| 99 | uint8_t ta; |
| 100 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 101 | llist_for_each_entry(ta_entry, &m_ta_list, list) { |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 102 | if (ta_entry->tlli == tlli) { |
| 103 | ta = ta_entry->ta; |
| 104 | #ifdef DEBUG_TA |
| 105 | fprintf(stderr, "recall %08x %d\n", tlli, ta); |
| 106 | #endif |
| 107 | return ta; |
| 108 | } |
| 109 | } |
| 110 | #ifdef DEBUG_TA |
| 111 | fprintf(stderr, "no entry for %08x\n", tlli); |
| 112 | #endif |
| 113 | |
| 114 | return -EINVAL; |
| 115 | } |
| 116 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 117 | int TimingAdvance::flush() |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 118 | { |
| 119 | struct gprs_rlcmac_ta *ta_entry; |
| 120 | int count = 0; |
| 121 | |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 122 | while (!llist_empty(&m_ta_list)) { |
| 123 | ta_entry = llist_entry(m_ta_list.next, |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 124 | struct gprs_rlcmac_ta, list); |
| 125 | #ifdef DEBUG_TA |
| 126 | fprintf(stderr, "flush entry %08x %d\n", ta_entry->tlli, |
| 127 | ta_entry->ta); |
| 128 | #endif |
| 129 | llist_del(&ta_entry->list); |
| 130 | talloc_free(ta_entry); |
| 131 | count++; |
| 132 | } |
Holger Hans Peter Freyther | 111614a | 2013-10-19 20:04:57 +0200 | [diff] [blame] | 133 | m_ta_len = 0; |
Holger Hans Peter Freyther | d6ef534 | 2013-10-19 19:50:00 +0200 | [diff] [blame] | 134 | |
| 135 | return count; |
| 136 | } |
| 137 | |
Holger Hans Peter Freyther | bc1626e | 2013-10-30 19:50:49 +0100 | [diff] [blame] | 138 | int TimingAdvance::update(uint32_t, uint32_t new_tlli, uint8_t ta) |
| 139 | { |
| 140 | /* for now just add the new entry and don't bother about the old one */ |
| 141 | return remember(new_tlli, ta); |
| 142 | } |