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osmo-msc/src/abis_rsl.c

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/* GSM Radio Signalling Link messages on the A-bis interface
* 3GPP TS 08.58 version 8.6.0 Release 1999 / ETSI TS 100 596 V8.6.0 */
/* (C) 2008 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 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include "gsm_data.h"
#include "gsm_04_08.h"
#include "abis_rsl.h"
#include "debug.h"
#include "tlv.h"
#define RSL_ALLOC_SIZE 1024
static u_int8_t mdisc_by_msgtype(u_int8_t msg_type)
{
/* mask off the transparent bit ? */
msg_type &= 0xfe;
if (msg_type & 0xf0 == 0x00)
return ABIS_RSL_MDISC_RLL;
if (msg_type & 0xf0 == 0x10) {
if (msg_type >= 0x19 && msg_type <= 0x22)
return ABIS_RSL_MDISC_TRX;
else
return ABIS_RSL_MDISC_COM_CHAN;
}
if (msg_type & 0xc == 0x00)
return ABIS_RSL_MDISC_DED_CHAN;
return ABIS_RSL_MDISC_LOC;
}
static inline void init_dchan_hdr(struct abis_rsl_dchan_hdr *dh,
u_int8_t msg_type)
{
dh->c.msg_discr = mdisc_by_msgtype(msg_type);
dh->c.msg_type = msg_type;
dh->ie_chan = RSL_IE_CHAN_NR;
}
static inline void init_llm_hdr(struct abis_rsl_rll_hdr *dh,
u_int8_t msg_type)
{
/* dh->c.msg_discr = mdisc_by_msgtype(msg_type); */
dh->c.msg_discr = ABIS_RSL_MDISC_RLL;
dh->c.msg_type = msg_type;
dh->ie_chan = RSL_IE_CHAN_NR;
dh->ie_link_id = RSL_IE_LINK_IDENT;
}
/* encode channel number as per Section 9.3.1 */
u_int8_t rsl_enc_chan_nr(u_int8_t type, u_int8_t subch, u_int8_t timeslot)
{
u_int8_t ret;
ret = (timeslot & 0x07) | type;
switch (type) {
case RSL_CHAN_Lm_ACCHs:
subch &= 0x01;
break;
case RSL_CHAN_SDCCH4_ACCH:
subch &= 0x07;
break;
case RSL_CHAN_SDCCH8_ACCH:
subch &= 0x07;
break;
default:
/* no subchannels allowed */
subch = 0x00;
break;
}
ret |= (subch << 3);
return ret;
}
/* As per TS 03.03 Section 2.2, the IMSI has 'not more than 15 digits' */
u_int64_t str_to_imsi(const char *imsi_str)
{
u_int64_t ret;
ret = strtoull(imsi_str, NULL, 10);
return ret;
}
/* Table 5 Clause 7 TS 05.02 */
unsigned int n_pag_blocks(int bs_ccch_sdcch_comb, unsigned int bs_ag_blks_res)
{
if (!bs_ccch_sdcch_comb)
return 9 - bs_ag_blks_res;
else
return 3 - bs_ag_blks_res;
}
/* Chapter 6.5.2 of TS 05.02 */
unsigned int get_ccch_group(u_int64_t imsi, unsigned int bs_cc_chans,
unsigned int n_pag_blocks)
{
return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) / n_pag_blocks;
}
/* Chapter 6.5.2 of TS 05.02 */
unsigned int get_paging_group(u_int64_t imsi, unsigned int bs_cc_chans,
int n_pag_blocks)
{
return (imsi % 1000) % (bs_cc_chans * n_pag_blocks) % n_pag_blocks;
}
/* Send a BCCH_INFO message as per Chapter 8.5.1 */
int rsl_bcch_info(struct gsm_bts *bts, u_int8_t type,
const u_int8_t *data, int len)
{
struct abis_rsl_dchan_hdr *dh;
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof*dh);
init_dchan_hdr(dh, RSL_MT_BCCH_INFO);
dh->chan_nr = RSL_CHAN_BCCH;
msgb_tv_put(msg, RSL_IE_SYSINFO_TYPE, type);
msgb_tlv_put(msg, RSL_IE_FULL_BCCH_INFO, len, data);
return abis_rsl_sendmsg(bts, msg);
}
int rsl_sacch_filling(struct gsm_bts *bts, u_int8_t type,
const u_int8_t *data, int len)
{
struct abis_rsl_common_hdr *ch;
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
ch = (struct abis_rsl_common_hdr *) msgb_put(msg, sizeof(*ch));
ch->msg_discr = ABIS_RSL_MDISC_TRX;
ch->msg_type = RSL_MT_SACCH_FILL;
msgb_tv_put(msg, RSL_IE_SYSINFO_TYPE, type);
msgb_tlv_put(msg, RSL_IE_L3_INFO, len, data);
return abis_rsl_sendmsg(bts, msg);
}
/* Chapter 8.4.1 */
int rsl_chan_activate(struct gsm_bts *bts, u_int8_t chan_nr,
u_int8_t act_type,
struct rsl_ie_chan_mode *chan_mode,
struct rsl_ie_chan_ident *chan_ident,
u_int8_t bs_power, u_int8_t ms_power,
u_int8_t ta)
{
struct abis_rsl_dchan_hdr *dh;
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
u_int8_t encr_info = 0x01;
dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));
init_dchan_hdr(dh, RSL_MT_CHAN_ACTIV);
dh->chan_nr = chan_nr;
msgb_tv_put(msg, RSL_IE_ACT_TYPE, act_type);
/* For compatibility with Phase 1 */
msgb_tlv_put(msg, RSL_IE_CHAN_MODE, sizeof(*chan_mode),
(u_int8_t *) chan_mode);
msgb_tlv_put(msg, RSL_IE_CHAN_IDENT, 4,
(u_int8_t *) &chan_ident);
/* FIXME: this shoould be optional */
msgb_tlv_put(msg, RSL_IE_ENCR_INFO, 1,
(u_int8_t *) &encr_info);
msgb_tv_put(msg, RSL_IE_BS_POWER, bs_power);
msgb_tv_put(msg, RSL_IE_MS_POWER, ms_power);
msgb_tv_put(msg, RSL_IE_TIMING_ADVANCE, ta);
return abis_rsl_sendmsg(bts, msg);
}
#define TSC 7
int rsl_chan_activate_tch_f(struct gsm_bts_trx_ts *ts)
{
u_int8_t chan_nr = rsl_enc_chan_nr(RSL_CHAN_Bm_ACCHs, 0, ts->nr);
u_int16_t arfcn = ts->trx->arfcn;
struct rsl_ie_chan_mode cm;
struct rsl_ie_chan_ident ci;
cm.dtx_dtu = 0;
cm.spd_ind = RSL_CMOD_SPD_SPEECH;
cm.chan_rt = RSL_CMOD_CRT_TCH_Bm;
cm.chan_rate = RSL_CMOD_SP_GSM1;
ci.chan_desc.iei = 0x64;
ci.chan_desc.chan_nr = chan_nr;
/* FIXME: this doesn't support hopping */
ci.chan_desc.oct3 = (TSC << 5) | ((arfcn & 0x3ff) >> 8);
ci.chan_desc.oct4 = arfcn & 0xff;
#if 0
ci.mobile_alloc.tag = 0x72;
ci.mobile_alloc.len = 0; /* as per Section 9.3.5 */
#endif
return rsl_chan_activate(ts->trx->bts, chan_nr, 0x01, &cm, &ci, 0x01, 0x0f, 0x00);
}
int rsl_chan_activate_sdcch(struct gsm_bts_trx_ts *ts)
{
u_int8_t chan_nr = rsl_enc_chan_nr(RSL_CHAN_SDCCH4_ACCH, 0, ts->nr);
u_int16_t arfcn = ts->trx->arfcn;
struct rsl_ie_chan_mode cm;
struct rsl_ie_chan_ident ci;
cm.dtx_dtu = 0x00;
cm.spd_ind = RSL_CMOD_SPD_SIGN;
cm.chan_rt = RSL_CMOD_CRT_SDCCH;
cm.chan_rate = 0x00;
ci.chan_desc.iei = 0x64;
ci.chan_desc.chan_nr = chan_nr;
ci.chan_desc.oct3 = (TSC << 5) | ((arfcn & 0x3ff) >> 8);
ci.chan_desc.oct4 = arfcn & 0xff;
/* FIXME: we're sending BS power IE, whcih Abissim doesn't */
return rsl_chan_activate(ts->trx->bts, chan_nr, 0x00, &cm, &ci, 0x01, 0x0f, 0x00);
}
int rsl_chan_release(struct gsm_bts_trx_ts *ts, u_int8_t chan_nr)
{
struct abis_rsl_dchan_hdr *dh;
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));
init_dchan_hdr(dh, RSL_MT_RF_CHAN_REL);
dh->chan_nr = chan_nr;
return abis_rsl_sendmsg(ts->trx->bts, msg);
}
int rsl_paging_cmd(struct gsm_bts *bts, u_int8_t paging_group, u_int8_t len,
u_int8_t *ms_ident, u_int8_t chan_needed)
{
struct abis_rsl_dchan_hdr *dh;
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));
init_dchan_hdr(dh, RSL_MT_PAGING_CMD);
dh->chan_nr = RSL_CHAN_PCH_AGCH;
msgb_tv_put(msg, RSL_IE_PAGING_GROUP, paging_group);
msgb_tlv_put(msg, RSL_IE_MS_IDENTITY, len, ms_ident);
msgb_tv_put(msg, RSL_IE_CHAN_NEEDED, chan_needed);
return abis_rsl_sendmsg(bts, msg);
}
int imsi_str2bcd(u_int8_t *bcd_out, const char *str_in)
{
int i, len = strlen(str_in);
for (i = 0; i < len; i++) {
int num = str_in[i] - 0x30;
if (num < 0 || num > 9)
return -1;
if (i % 2 == 0)
bcd_out[i/2] = num;
else
bcd_out[i/2] |= (num << 4);
}
return 0;
}
# if 0
int rsl_paging_cmd_imsi(struct gsm_bts *bts, u_int8_t chan_needed, const char *imsi_str)
{
/* FIXME: derive the MS Identity */
return rsl_paging_cmd(bts, paging_group, x, y, chan_needed);
}
#endif
int rsl_imm_assign_cmd(struct gsm_bts *bts, u_int8_t len, u_int8_t *val)
{
struct msgb *msg = msgb_alloc(RSL_ALLOC_SIZE);
struct abis_rsl_dchan_hdr *dh;
dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));
init_dchan_hdr(dh, RSL_MT_IMMEDIATE_ASSIGN_CMD);
dh->chan_nr = RSL_CHAN_PCH_AGCH;
/* If phase 2, FULL_IMM_ASS_INFO */
msgb_tlv_put(msg, RSL_IE_IMM_ASS_INFO, len, val);
return abis_rsl_sendmsg(bts, msg);
}
/* Chapter 8.3.1 */
int rsl_data_request(struct gsm_bts *bts, struct msgb *msg)
{
/* FIXME: prepend RSL header to layer 3 message */
u_int8_t len = msg->len;
struct abis_rsl_rll_hdr *rh;
msgb_tv_push(msg, RSL_IE_L3_INFO, len);
rh = (struct abis_rsl_rll_hdr *) msgb_push(msg, sizeof(*rh));
init_llm_hdr(rh, RSL_MT_DATA_REQ);
rh->chan_nr = RSL_CHAN_SDCCH4_ACCH; /* FIXME: don't harcode */
return abis_rsl_sendmsg(bts, msg);
}
static int abis_rsl_rx_dchan(struct msgb *msg)
{
struct abis_rsl_common_hdr *rslh = msgb_l2(msg) ;
switch (rslh->msg_type) {
case RSL_MT_CHAN_ACTIV_ACK:
case RSL_MT_CHAN_ACTIV_NACK:
case RSL_MT_CONN_FAIL:
case RSL_MT_MEAS_RES:
case RSL_MT_MODE_MODIFY_ACK:
case RSL_MT_MODE_MODIFY_NACK:
case RSL_MT_PHY_CONTEXT_CONF:
case RSL_MT_PREPROC_MEAS_RES:
case RSL_MT_RF_CHAN_REL_ACK:
case RSL_MT_TALKER_DET:
case RSL_MT_LISTENER_DET:
case RSL_MT_REMOTE_CODEC_CONF_REP:
case RSL_MT_MR_CODEC_MOD_ACK:
case RSL_MT_MR_CODEC_MOD_NACK:
case RSL_MT_MR_CODEC_MOD_PER:
fprintf(stderr, "Unimplemented Abis RSL DChan msg 0x%02x\n",
rslh->msg_type);
break;
default:
fprintf(stderr, "unknown Abis RSL DChan msg 0x%02x\n",
rslh->msg_type);
return -EINVAL;
}
}
static int abis_rsl_rx_trx(struct msgb *msg)
{
struct abis_rsl_common_hdr *rslh = msgb_l2(msg) ;
switch (rslh->msg_type) {
case RSL_MT_RF_RES_IND:
/* interference on idle channels of TRX */
case RSL_MT_OVERLOAD:
/* indicate CCCH / ACCH / processor overload */
case RSL_MT_ERROR_REPORT:
fprintf(stderr, "Unimplemented Abis RSL TRX message type 0x%02x\n",
rslh->msg_type);
break;
default:
fprintf(stderr, "Unknown Abis RSL TRX message type 0x%02x\n",
rslh->msg_type);
return -EINVAL;
}
}
static int rsl_rx_chan_rqd(struct msgb *msg)
{
struct gsm_bts *bts = msg->bts_link->bts;
struct gsm48_imm_ass ia;
u_int16_t arfcn;
u_int8_t ts_number, subch;
/* MS has requested a channel on the RACH */
/* parse channel number, request reference, access delay */
/* FIXME: check permission/availability */
ts_number = 0;
arfcn = HARDCODED_ARFCN;
subch = 0;
/* send CHANNEL ACTIVATION on RSL to BTS */
rsl_chan_activate_sdcch(&bts->trx[0].ts[ts_number]);
/* create IMMEDIATE ASSIGN 04.08 messge */
memset(&ia, 0, sizeof(ia));
ia.l2_plen = 0x2d;
ia.proto_discr = GSM48_PDISC_RR;
ia.msg_type = GSM48_MT_RR_IMM_ASS;
ia.page_mode = GSM48_PM_NORMAL;
ia.chan_desc.chan_nr = rsl_enc_chan_nr(RSL_CHAN_SDCCH4_ACCH, subch, ts_number);
ia.chan_desc.h0.h = 0;
ia.chan_desc.h0.arfcn_high = arfcn >> 8;
ia.chan_desc.h0.arfcn_low = arfcn & 0xff;
ia.chan_desc.h0.tsc = 7;
/* FIXME: use real request reference extracted from CHAN_RQD */
ia.req_ref.ra = 0x80 | 0x1e;
ia.req_ref.t2 = 0x0c;
ia.req_ref.t1_ = 0x12;
ia.req_ref.t3_low = 0x19 & 3;
ia.req_ref.t3_high = 0x19 >> 3;
ia.timing_advance = 0;
ia.mob_alloc_len = 0;
/* send IMMEDIATE ASSIGN CMD on RSL to BTS (to send on CCCH to MS) */
return rsl_imm_assign_cmd(bts, sizeof(ia), (u_int8_t *) &ia);
}
static int abis_rsl_rx_cchan(struct msgb *msg)
{
struct abis_rsl_common_hdr *rslh = msgb_l2(msg) ;
int rc;
switch (rslh->msg_type) {
case RSL_MT_CHAN_RQD:
/* MS has requested a channel on the RACH */
rc = rsl_rx_chan_rqd(msg);
break;
case RSL_MT_DELETE_IND:
/* CCCH overloaded, IMM_ASSIGN was dropped */
case RSL_MT_CBCH_LOAD_IND:
/* current load on the CBCH */
case RSL_MT_CCCH_LOAD_IND:
/* current load on the CCCH */
fprintf(stderr, "Unimplemented Abis RSL TRX message type 0x%02x\n",
rslh->msg_type);
break;
default:
fprintf(stderr, "Unknown Abis RSL TRX message type 0x%02x\n",
rslh->msg_type);
return -EINVAL;
}
}
/* ESTABLISH INDICATION, LOCATION AREA UPDATE REQUEST
0x02, 0x06,
0x01, 0x20,
0x02, 0x00,
0x0b, 0x00, 0x0f, 0x05, 0x08, ... */
static int abis_rsl_rx_rll(struct msgb *msg)
{
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
int rc;
switch (rllh->c.msg_type) {
case RSL_MT_DATA_IND:
DEBUGP(DRLL, "DATA INDICATION\n");
/* FIXME: parse L3 info element */
rc = gsm0408_rcvmsg(msg);
break;
case RSL_MT_EST_IND:
DEBUGP(DRLL, "ESTABLISH INDICATION\n");
/* FIXME: parse L3 info element */
rc = gsm0408_rcvmsg(msg);
break;
case RSL_MT_ERROR_IND:
case RSL_MT_REL_IND:
case RSL_MT_UNIT_DATA_IND:
fprintf(stderr, "unimplemented Abis RLL message type 0x%02x\n",
rllh->c.msg_type);
break;
default:
fprintf(stderr, "unknown Abis RLL message type 0x%02x\n",
rllh->c.msg_type);
}
}
/* Entry-point where L2 RSL from BTS enters */
int abis_rsl_rx(struct msgb *msg)
{
struct abis_rsl_common_hdr *rslh = msgb_l2(msg) ;
unsigned int l2_len = (void *)msg->tail - msgb_l2(msg);
int rc;
switch (rslh->msg_discr & 0xfe) {
case ABIS_RSL_MDISC_RLL:
rc = abis_rsl_rx_rll(msg);
break;
case ABIS_RSL_MDISC_DED_CHAN:
rc = abis_rsl_rx_dchan(msg);
break;
case ABIS_RSL_MDISC_COM_CHAN:
case ABIS_RSL_MDISC_TRX:
rc = abis_rsl_rx_cchan(msg);
break;
case ABIS_RSL_MDISC_LOC:
default:
fprintf(stderr, "unknown RSL message discriminator 0x%02x\n",
rslh->msg_discr);
return -EINVAL;
}
}
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