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osmo-bts/src/common/bts.c

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/* BTS support code common to all supported BTS models */
/* (C) 2011 by Andreas Eversberg <jolly@eversberg.eu>
* (C) 2011 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 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 Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <osmocom/core/select.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <osmocom/gsm/protocol/gsm_12_21.h>
#include <osmocom/gsm/lapdm.h>
#include <osmocom/trau/osmo_ortp.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/abis.h>
#include <osmo-bts/bts.h>
#include <osmo-bts/bts_model.h>
#include <osmo-bts/rsl.h>
#include <osmo-bts/oml.h>
#include <osmo-bts/signal.h>
static void bts_update_agch_max_queue_length(struct gsm_bts *bts);
struct gsm_network bts_gsmnet = {
.bts_list = { &bts_gsmnet.bts_list, &bts_gsmnet.bts_list },
.num_bts = 0,
};
void *tall_bts_ctx;
/* Table 3.1 TS 04.08: Values of parameter S */
static const uint8_t tx_integer[] = {
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 20, 25, 32, 50,
};
static const uint8_t s_values[][2] = {
{ 55, 41 }, { 76, 52 }, { 109, 58 }, { 163, 86 }, { 217, 115 },
};
static int bts_signal_cbfn(unsigned int subsys, unsigned int signal,
void *hdlr_data, void *signal_data)
{
if (subsys == SS_GLOBAL && signal == S_NEW_SYSINFO) {
struct gsm_bts *bts = signal_data;
bts_update_agch_max_queue_length(bts);
}
return 0;
}
/* Initialize the BTS (and TRX) data structures, called before config
* file reading */
int bts_init(struct gsm_bts *bts)
{
struct gsm_bts_role_bts *btsb;
struct gsm_bts_trx *trx;
int rc, i;
static int initialized = 0;
void *tall_rtp_ctx;
/* add to list of BTSs */
llist_add_tail(&bts->list, &bts_gsmnet.bts_list);
bts->band = GSM_BAND_1800;
bts->role = btsb = talloc_zero(bts, struct gsm_bts_role_bts);
INIT_LLIST_HEAD(&btsb->agch_queue);
btsb->agch_queue_length = 0;
/* enable management with default levels,
* raise threshold to GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DISABLE to
* disable this feature.
*/
btsb->agch_queue_low_level = GSM_BTS_AGCH_QUEUE_LOW_LEVEL_DEFAULT;
btsb->agch_queue_high_level = GSM_BTS_AGCH_QUEUE_HIGH_LEVEL_DEFAULT;
btsb->agch_queue_thresh_level = GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DEFAULT;
/* configurable via VTY */
btsb->paging_state = paging_init(btsb, 200, 0);
btsb->ul_power_target = -75; /* dBm default */
/* configurable via OML */
btsb->load.ccch.load_ind_period = 112;
load_timer_start(bts);
btsb->rtp_jitter_buf_ms = 100;
btsb->max_ta = 63;
btsb->ny1 = 4;
btsb->t3105_ms = 300;
for (i = 0; i < ARRAY_SIZE(btsb->t200_ms); i++)
btsb->t200_ms[i] = oml_default_t200_ms[i];
/* default RADIO_LINK_TIMEOUT */
btsb->radio_link_timeout = 32;
/* Start with the site manager */
oml_mo_state_init(&bts->site_mgr.mo, NM_OPSTATE_ENABLED, NM_AVSTATE_OK);
/* set BTS to dependency */
oml_mo_state_init(&bts->mo, -1, NM_AVSTATE_DEPENDENCY);
oml_mo_state_init(&bts->gprs.nse.mo, -1, NM_AVSTATE_DEPENDENCY);
oml_mo_state_init(&bts->gprs.cell.mo, -1, NM_AVSTATE_DEPENDENCY);
oml_mo_state_init(&bts->gprs.nsvc[0].mo, -1, NM_AVSTATE_DEPENDENCY);
oml_mo_state_init(&bts->gprs.nsvc[1].mo, NM_OPSTATE_DISABLED, NM_AVSTATE_OFF_LINE);
/* initialize bts data structure */
llist_for_each_entry(trx, &bts->trx_list, list) {
struct trx_power_params *tpp = &trx->power_params;
int i;
for (i = 0; i < ARRAY_SIZE(trx->ts); i++) {
struct gsm_bts_trx_ts *ts = &trx->ts[i];
int k;
for (k = 0; k < ARRAY_SIZE(ts->lchan); k++) {
struct gsm_lchan *lchan = &ts->lchan[k];
INIT_LLIST_HEAD(&lchan->dl_tch_queue);
}
}
/* Default values for the power adjustments */
tpp->ramp.max_initial_pout_mdBm = to_mdB(23);
tpp->ramp.step_size_mdB = to_mdB(2);
tpp->ramp.step_interval_sec = 1;
}
/* allocate a talloc pool for ORTP to ensure it doesn't have to go back
* to the libc malloc all the time */
tall_rtp_ctx = talloc_pool(tall_bts_ctx, 262144);
osmo_rtp_init(tall_rtp_ctx);
rc = bts_model_init(bts);
if (rc < 0) {
llist_del(&bts->list);
return rc;
}
bts_gsmnet.num_bts++;
if (!initialized) {
osmo_signal_register_handler(SS_GLOBAL, bts_signal_cbfn, NULL);
initialized = 1;
}
INIT_LLIST_HEAD(&btsb->smscb_state.queue);
INIT_LLIST_HEAD(&btsb->oml_queue);
return rc;
}
static void shutdown_timer_cb(void *data)
{
fprintf(stderr, "Shutdown timer expired\n");
exit(42);
}
static struct osmo_timer_list shutdown_timer = {
.cb = &shutdown_timer_cb,
};
void bts_shutdown(struct gsm_bts *bts, const char *reason)
{
struct gsm_bts_trx *trx;
if (osmo_timer_pending(&shutdown_timer)) {
LOGP(DOML, LOGL_NOTICE,
"BTS is already being shutdown.\n");
return;
}
LOGP(DOML, LOGL_NOTICE, "Shutting down BTS %u, Reason %s\n",
bts->nr, reason);
llist_for_each_entry(trx, &bts->trx_list, list) {
bts_model_trx_deact_rf(trx);
bts_model_trx_close(trx);
}
/* shedule a timer to make sure select loop logic can run again
* to dispatch any pending primitives */
osmo_timer_schedule(&shutdown_timer, 3, 0);
}
/* main link is established, send status report */
int bts_link_estab(struct gsm_bts *bts)
{
int i, j;
LOGP(DSUM, LOGL_INFO, "Main link established, sending Status'.\n");
/* BTS and SITE MGR are EANBLED, BTS is DEPENDENCY */
oml_tx_state_changed(&bts->site_mgr.mo);
oml_tx_state_changed(&bts->mo);
/* those should all be in DEPENDENCY */
oml_tx_state_changed(&bts->gprs.nse.mo);
oml_tx_state_changed(&bts->gprs.cell.mo);
oml_tx_state_changed(&bts->gprs.nsvc[0].mo);
oml_tx_state_changed(&bts->gprs.nsvc[1].mo);
/* All other objects start off-line until the BTS Model code says otherwise */
for (i = 0; i < bts->num_trx; i++) {
struct gsm_bts_trx *trx = gsm_bts_trx_num(bts, i);
oml_tx_state_changed(&trx->mo);
oml_tx_state_changed(&trx->bb_transc.mo);
for (j = 0; j < ARRAY_SIZE(trx->ts); j++) {
struct gsm_bts_trx_ts *ts = &trx->ts[j];
oml_tx_state_changed(&ts->mo);
}
}
return bts_model_oml_estab(bts);
}
/* RSL link is established, send status report */
int trx_link_estab(struct gsm_bts_trx *trx)
{
struct e1inp_sign_link *link = trx->rsl_link;
uint8_t radio_state = link ? NM_OPSTATE_ENABLED : NM_OPSTATE_DISABLED;
LOGP(DSUM, LOGL_INFO, "RSL link (TRX %02x) state changed to %s, sending Status'.\n",
trx->nr, link ? "up" : "down");
oml_mo_state_chg(&trx->mo, radio_state, NM_AVSTATE_OK);
if (link)
rsl_tx_rf_res(trx);
else
bts_model_trx_deact_rf(trx);
return 0;
}
/* set the availability of the TRX (used by PHY driver) */
int trx_set_available(struct gsm_bts_trx *trx, int avail)
{
int tn;
LOGP(DSUM, LOGL_INFO, "TRX(%d): Setting available = %d\n",
trx->nr, avail);
if (avail) {
oml_mo_state_chg(&trx->mo, NM_OPSTATE_DISABLED, NM_AVSTATE_OK);
oml_mo_tx_sw_act_rep(&trx->mo);
oml_mo_state_chg(&trx->bb_transc.mo, -1, NM_AVSTATE_OK);
oml_mo_tx_sw_act_rep(&trx->bb_transc.mo);
for (tn = 0; tn < ARRAY_SIZE(trx->ts); tn++)
oml_mo_state_chg(&trx->ts[tn].mo, NM_OPSTATE_DISABLED, NM_AVSTATE_DEPENDENCY);
} else {
oml_mo_state_chg(&trx->mo, NM_OPSTATE_DISABLED, NM_AVSTATE_OFF_LINE);
oml_mo_state_chg(&trx->bb_transc.mo, -1, NM_AVSTATE_OFF_LINE);
for (tn = 0; tn < ARRAY_SIZE(trx->ts); tn++)
oml_mo_state_chg(&trx->ts[tn].mo, NM_OPSTATE_DISABLED, NM_AVSTATE_OFF_LINE);
}
return 0;
}
int lchan_init_lapdm(struct gsm_lchan *lchan)
{
struct lapdm_channel *lc = &lchan->lapdm_ch;
lapdm_channel_init(lc, LAPDM_MODE_BTS);
lapdm_channel_set_flags(lc, LAPDM_ENT_F_POLLING_ONLY);
lapdm_channel_set_l1(lc, NULL, lchan);
lapdm_channel_set_l3(lc, lapdm_rll_tx_cb, lchan);
oml_set_lchan_t200(lchan);
return 0;
}
#define CCCH_RACH_RATIO_COMBINED256 (256*1/9)
#define CCCH_RACH_RATIO_SEPARATE256 (256*10/55)
int bts_agch_max_queue_length(int T, int bcch_conf)
{
int S, ccch_rach_ratio256, i;
int T_group = 0;
int is_ccch_comb = 0;
if (bcch_conf == RSL_BCCH_CCCH_CONF_1_C)
is_ccch_comb = 1;
/*
* The calculation is based on the ratio of the number RACH slots and
* CCCH blocks per time:
* Lmax = (T + 2*S) / R_RACH * R_CCCH
* where
* T3126_min = (T + 2*S) / R_RACH, as defined in GSM 04.08, 11.1.1
* R_RACH is the RACH slot rate (e.g. RACHs per multiframe)
* R_CCCH is the CCCH block rate (same time base like R_RACH)
* S and T are defined in GSM 04.08, 3.3.1.1.2
* The ratio is mainly influenced by the downlink only channels
* (BCCH, FCCH, SCH, CBCH) that can not be used for CCCH.
* An estimation with an error of < 10% is used:
* ~ 1/9 if CCCH is combined with SDCCH, and
* ~ 1/5.5 otherwise.
*/
ccch_rach_ratio256 = is_ccch_comb ?
CCCH_RACH_RATIO_COMBINED256 :
CCCH_RACH_RATIO_SEPARATE256;
for (i = 0; i < ARRAY_SIZE(tx_integer); i++) {
if (tx_integer[i] == T) {
T_group = i % 5;
break;
}
}
S = s_values[T_group][is_ccch_comb];
return (T + 2 * S) * ccch_rach_ratio256 / 256;
}
static void bts_update_agch_max_queue_length(struct gsm_bts *bts)
{
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
struct gsm48_system_information_type_3 *si3;
int old_max_length = btsb->agch_max_queue_length;
if (!(bts->si_valid & (1<<SYSINFO_TYPE_3)))
return;
si3 = GSM_BTS_SI(bts, SYSINFO_TYPE_3);
btsb->agch_max_queue_length =
bts_agch_max_queue_length(si3->rach_control.tx_integer,
si3->control_channel_desc.ccch_conf);
if (btsb->agch_max_queue_length != old_max_length)
LOGP(DRSL, LOGL_INFO, "Updated AGCH max queue length to %d\n",
btsb->agch_max_queue_length);
}
#define REQ_REFS_PER_IMM_ASS_REJ 4
static int store_imm_ass_rej_refs(struct gsm48_imm_ass_rej *rej,
struct gsm48_req_ref *req_refs,
uint8_t *wait_inds,
int count)
{
switch (count) {
case 0:
/* TODO: Warning ? */
return 0;
default:
count = 4;
rej->req_ref4 = req_refs[3];
rej->wait_ind4 = wait_inds[3];
/* fall through */
case 3:
rej->req_ref3 = req_refs[2];
rej->wait_ind3 = wait_inds[2];
/* fall through */
case 2:
rej->req_ref2 = req_refs[1];
rej->wait_ind2 = wait_inds[1];
/* fall through */
case 1:
rej->req_ref1 = req_refs[0];
rej->wait_ind1 = wait_inds[0];
break;
}
switch (count) {
case 1:
rej->req_ref2 = req_refs[0];
rej->wait_ind2 = wait_inds[0];
/* fall through */
case 2:
rej->req_ref3 = req_refs[0];
rej->wait_ind3 = wait_inds[0];
/* fall through */
case 3:
rej->req_ref4 = req_refs[0];
rej->wait_ind4 = wait_inds[0];
/* fall through */
default:
break;
}
return count;
}
static int extract_imm_ass_rej_refs(struct gsm48_imm_ass_rej *rej,
struct gsm48_req_ref *req_refs,
uint8_t *wait_inds)
{
int count = 0;
req_refs[count] = rej->req_ref1;
wait_inds[count] = rej->wait_ind1;
count++;
if (memcmp(&rej->req_ref1, &rej->req_ref2, sizeof(rej->req_ref2))) {
req_refs[count] = rej->req_ref2;
wait_inds[count] = rej->wait_ind2;
count++;
}
if (memcmp(&rej->req_ref1, &rej->req_ref3, sizeof(rej->req_ref3)) &&
memcmp(&rej->req_ref2, &rej->req_ref3, sizeof(rej->req_ref3))) {
req_refs[count] = rej->req_ref3;
wait_inds[count] = rej->wait_ind3;
count++;
}
if (memcmp(&rej->req_ref1, &rej->req_ref4, sizeof(rej->req_ref4)) &&
memcmp(&rej->req_ref2, &rej->req_ref4, sizeof(rej->req_ref4)) &&
memcmp(&rej->req_ref3, &rej->req_ref4, sizeof(rej->req_ref4))) {
req_refs[count] = rej->req_ref4;
wait_inds[count] = rej->wait_ind4;
count++;
}
return count;
}
static int try_merge_imm_ass_rej(struct gsm48_imm_ass_rej *old_rej,
struct gsm48_imm_ass_rej *new_rej)
{
struct gsm48_req_ref req_refs[2 * REQ_REFS_PER_IMM_ASS_REJ];
uint8_t wait_inds[2 * REQ_REFS_PER_IMM_ASS_REJ];
int count = 0;
int stored = 0;
if (new_rej->msg_type != GSM48_MT_RR_IMM_ASS_REJ)
return 0;
if (old_rej->msg_type != GSM48_MT_RR_IMM_ASS_REJ)
return 0;
/* GSM 08.58, 5.7
* -> The BTS may combine serveral IMM.ASS.REJ messages
* -> Identical request refs in one message may be squeezed
*
* GSM 04.08, 9.1.20.2
* -> Request ref and wait ind are duplicated to fill the message
*/
/* Extract all entries */
count = extract_imm_ass_rej_refs(old_rej,
&req_refs[count], &wait_inds[count]);
if (count == REQ_REFS_PER_IMM_ASS_REJ)
return 0;
count += extract_imm_ass_rej_refs(new_rej,
&req_refs[count], &wait_inds[count]);
/* Store entries into old message */
stored = store_imm_ass_rej_refs(old_rej,
&req_refs[stored], &wait_inds[stored],
count);
count -= stored;
if (count == 0)
return 1;
/* Store remaining entries into new message */
stored += store_imm_ass_rej_refs(new_rej,
&req_refs[stored], &wait_inds[stored],
count);
return 0;
}
int bts_agch_enqueue(struct gsm_bts *bts, struct msgb *msg)
{
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
int hard_limit = 1000;
struct gsm48_imm_ass_rej *imm_ass_cmd = msgb_l3(msg);
if (btsb->agch_queue_length > hard_limit) {
LOGP(DSUM, LOGL_ERROR,
"AGCH: too many messages in queue, "
"refusing message type 0x%02x, length = %d/%d\n",
((struct gsm48_imm_ass *)msgb_l3(msg))->msg_type,
btsb->agch_queue_length, btsb->agch_max_queue_length);
btsb->agch_queue_rejected_msgs++;
return -ENOMEM;
}
if (btsb->agch_queue_length > 0) {
struct msgb *last_msg =
llist_entry(btsb->agch_queue.prev, struct msgb, list);
struct gsm48_imm_ass_rej *last_imm_ass_rej = msgb_l3(last_msg);
if (try_merge_imm_ass_rej(last_imm_ass_rej, imm_ass_cmd)) {
btsb->agch_queue_merged_msgs++;
msgb_free(msg);
return 0;
}
}
msgb_enqueue(&btsb->agch_queue, msg);
btsb->agch_queue_length++;
return 0;
}
struct msgb *bts_agch_dequeue(struct gsm_bts *bts)
{
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
struct msgb *msg = msgb_dequeue(&btsb->agch_queue);
if (!msg)
return NULL;
btsb->agch_queue_length--;
return msg;
}
/*
* Remove lower prio messages if the queue has grown too long.
*
* \return 0 iff the number of messages in the queue would fit into the AGCH
* reserved part of the CCCH.
*/
static void compact_agch_queue(struct gsm_bts *bts)
{
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
struct msgb *msg, *msg2;
int max_len, slope, offs;
int level_low = btsb->agch_queue_low_level;
int level_high = btsb->agch_queue_high_level;
int level_thres = btsb->agch_queue_thresh_level;
max_len = btsb->agch_max_queue_length;
if (max_len == 0)
max_len = 1;
if (btsb->agch_queue_length < max_len * level_thres / 100)
return;
/* p^
* 1+ /'''''
* | /
* | /
* 0+---/--+----+--> Q length
* low high max_len
*/
offs = max_len * level_low / 100;
if (level_high > level_low)
slope = 0x10000 * 100 / (level_high - level_low);
else
slope = 0x10000 * max_len; /* p_drop >= 1 if len > offs */
llist_for_each_entry_safe(msg, msg2, &btsb->agch_queue, list) {
struct gsm48_imm_ass *imm_ass_cmd = msgb_l3(msg);
int p_drop;
if (imm_ass_cmd->msg_type != GSM48_MT_RR_IMM_ASS_REJ)
return;
/* IMMEDIATE ASSIGN REJECT */
p_drop = (btsb->agch_queue_length - offs) * slope / max_len;
if ((random() & 0xffff) >= p_drop)
return;
llist_del(&msg->list);
btsb->agch_queue_length--;
msgb_free(msg);
btsb->agch_queue_dropped_msgs++;
}
return;
}
int bts_ccch_copy_msg(struct gsm_bts *bts, uint8_t *out_buf, struct gsm_time *gt,
int is_ag_res)
{
struct msgb *msg = NULL;
struct gsm_bts_role_bts *btsb = bts->role;
int rc = 0;
int is_empty = 1;
/* Do queue house keeping.
* This needs to be done every time a CCCH message is requested, since
* the queue max length is calculated based on the CCCH block rate and
* PCH messages also reduce the drain of the AGCH queue.
*/
compact_agch_queue(bts);
/* Check for paging messages first if this is PCH */
if (!is_ag_res)
rc = paging_gen_msg(btsb->paging_state, out_buf, gt, &is_empty);
/* Check whether the block may be overwritten */
if (!is_empty)
return rc;
msg = bts_agch_dequeue(bts);
if (!msg)
return rc;
/* Copy AGCH message */
memcpy(out_buf, msgb_l3(msg), msgb_l3len(msg));
rc = msgb_l3len(msg);
msgb_free(msg);
if (is_ag_res)
btsb->agch_queue_agch_msgs++;
else
btsb->agch_queue_pch_msgs++;
return rc;
}
int bts_supports_cipher(struct gsm_bts_role_bts *bts, int rsl_cipher)
{
int sup;
if (rsl_cipher < 1 || rsl_cipher > 8)
return -ENOTSUP;
/* No encryption is always supported */
if (rsl_cipher == 1)
return 1;
sup = (1 << (rsl_cipher - 2)) & bts->support.ciphers;
return sup > 0;
}
int trx_ms_pwr_ctrl_is_osmo(struct gsm_bts_trx *trx)
{
return trx->ms_power_control == 1;
}
struct gsm_time *get_time(struct gsm_bts *bts)
{
struct gsm_bts_role_bts *btsb = bts->role;
return &btsb->gsm_time;
}
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