| /* Copied from tbf.cpp |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * Copyright (C) 2013 by Holger Hans Peter Freyther |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <tbf.h> |
| #include <bts.h> |
| |
| #include <stdio.h> |
| |
| extern "C" { |
| #include <osmocom/core/msgb.h> |
| } |
| |
| /* reset LLC frame */ |
| void gprs_llc::reset() |
| { |
| m_index = 0; |
| m_length = 0; |
| |
| memset(frame, 0x42, sizeof(frame)); |
| } |
| |
| void gprs_llc::reset_frame_space() |
| { |
| m_index = 0; |
| } |
| |
| /* Put an Unconfirmed Information (UI) Dummy command, see GSM 44.064, 6.4.2.2 */ |
| void gprs_llc::put_dummy_frame(size_t req_len) |
| { |
| /* The shortest dummy command (the spec requests at least 6 octets) */ |
| static const uint8_t llc_dummy_command[] = { |
| 0x43, 0xc0, 0x01, 0x2b, 0x2b, 0x2b |
| }; |
| static const size_t max_dummy_command_len = 79; |
| |
| put_frame(llc_dummy_command, sizeof(llc_dummy_command)); |
| |
| if (req_len > max_dummy_command_len) |
| req_len = max_dummy_command_len; |
| |
| /* Add further stuffing, if the requested length exceeds the minimum |
| * dummy command length */ |
| while (m_length < req_len) |
| frame[m_length++] = 0x2b; |
| } |
| |
| void gprs_llc::put_frame(const uint8_t *data, size_t len) |
| { |
| /* only put frames when we are empty */ |
| OSMO_ASSERT(m_index == 0 && m_length == 0); |
| append_frame(data, len); |
| } |
| |
| void gprs_llc::append_frame(const uint8_t *data, size_t len) |
| { |
| /* TODO: bounds check */ |
| memcpy(frame + m_length, data, len); |
| m_length += len; |
| } |
| |
| void gprs_llc::init() |
| { |
| reset(); |
| } |
| |
| bool gprs_llc::is_user_data_frame(uint8_t *data, size_t len) |
| { |
| if (len < 2) |
| return false; |
| |
| if ((data[0] & 0x0f) == 1 /* GPRS_SAPI_GMM */) |
| return false; |
| |
| if ((data[0] & 0xe0) != 0xc0 /* LLC UI */) |
| /* It is not an LLC UI frame, see TS 44.064, 6.3 */ |
| return false; |
| |
| return true; |
| } |
| |
| void gprs_llc_queue::init() |
| { |
| INIT_LLIST_HEAD(&m_queue); |
| m_queue_size = 0; |
| m_queue_octets = 0; |
| m_avg_queue_delay = 0; |
| } |
| |
| void gprs_llc_queue::enqueue(struct msgb *llc_msg, const MetaInfo *info) |
| { |
| static const MetaInfo def_meta = {{0}}; |
| MetaInfo *meta_storage; |
| |
| osmo_static_assert(sizeof(*info) <= sizeof(llc_msg->cb), info_does_not_fit); |
| |
| m_queue_size += 1; |
| m_queue_octets += msgb_length(llc_msg); |
| |
| meta_storage = (MetaInfo *)&llc_msg->cb[0]; |
| *meta_storage = info ? *info : def_meta; |
| |
| msgb_enqueue(&m_queue, llc_msg); |
| } |
| |
| void gprs_llc_queue::clear(BTS *bts) |
| { |
| struct msgb *msg; |
| |
| while ((msg = msgb_dequeue(&m_queue))) { |
| if (bts) |
| bts->llc_dropped_frame(); |
| msgb_free(msg); |
| } |
| |
| m_queue_size = 0; |
| m_queue_octets = 0; |
| } |
| |
| #define ALPHA 0.5f |
| |
| struct msgb *gprs_llc_queue::dequeue(const MetaInfo **info) |
| { |
| struct msgb *msg; |
| struct timeval *tv, tv_now, tv_result; |
| uint32_t lifetime; |
| const MetaInfo *meta_storage; |
| |
| msg = msgb_dequeue(&m_queue); |
| if (!msg) |
| return NULL; |
| |
| meta_storage = (MetaInfo *)&msg->cb[0]; |
| |
| if (info) |
| *info = meta_storage; |
| |
| m_queue_size -= 1; |
| m_queue_octets -= msgb_length(msg); |
| |
| /* take the second time */ |
| gettimeofday(&tv_now, NULL); |
| tv = (struct timeval *)&msg->data[sizeof(*tv)]; |
| timersub(&tv_now, &meta_storage->recv_time, &tv_result); |
| |
| lifetime = tv_result.tv_sec*1000 + tv_result.tv_usec/1000; |
| m_avg_queue_delay = m_avg_queue_delay * ALPHA + lifetime * (1-ALPHA); |
| |
| return msg; |
| } |
| |
| void gprs_llc_queue::calc_pdu_lifetime(BTS *bts, const uint16_t pdu_delay_csec, struct timeval *tv) |
| { |
| uint16_t delay_csec; |
| if (bts->bts_data()->force_llc_lifetime) |
| delay_csec = bts->bts_data()->force_llc_lifetime; |
| else |
| delay_csec = pdu_delay_csec; |
| |
| /* keep timestamp at 0 for infinite delay */ |
| if (delay_csec == 0xffff) { |
| memset(tv, 0, sizeof(*tv)); |
| return; |
| } |
| |
| /* calculate timestamp of timeout */ |
| struct timeval now, csec; |
| gettimeofday(&now, NULL); |
| csec.tv_usec = (delay_csec % 100) * 10000; |
| csec.tv_sec = delay_csec / 100; |
| |
| timeradd(&now, &csec, tv); |
| } |
| |
| bool gprs_llc_queue::is_frame_expired(const struct timeval *tv_now, |
| const struct timeval *tv) |
| { |
| /* Timeout is infinite */ |
| if (tv->tv_sec == 0 && tv->tv_usec == 0) |
| return false; |
| |
| return timercmp(tv_now, tv, >); |
| } |