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/* GSM 08.08 BSSMAP handling */
/* (C) 2009-2010 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2009-2010 by On-Waves
* 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 <openbsc/osmo_bsc.h>
#include <openbsc/osmo_bsc_grace.h>
#include <openbsc/debug.h>
#include <osmocore/gsm0808.h>
#include <osmocore/protocol/gsm_08_08.h>
#include <arpa/inet.h>
static uint16_t read_data16(const uint8_t *data)
{
uint16_t res;
memcpy(&res, data, sizeof(res));
return res;
}
static int bssmap_handle_reset_ack(struct gsm_network *net,
struct msgb *msg, unsigned int length)
{
LOGP(DMSC, LOGL_NOTICE, "Reset ACK from MSC\n");
return 0;
}
/* GSM 08.08 § 3.2.1.19 */
static int bssmap_handle_paging(struct gsm_network *net,
struct msgb *msg, unsigned int payload_length)
{
struct tlv_parsed tp;
char mi_string[GSM48_MI_SIZE];
uint32_t tmsi = GSM_RESERVED_TMSI;
unsigned int lac = GSM_LAC_RESERVED_ALL_BTS;
uint8_t data_length;
const uint8_t *data;
uint8_t chan_needed = RSL_CHANNEED_ANY;
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, payload_length - 1, 0, 0);
if (!TLVP_PRESENT(&tp, GSM0808_IE_IMSI)) {
LOGP(DMSC, LOGL_ERROR, "Mandantory IMSI not present.\n");
return -1;
} else if ((TLVP_VAL(&tp, GSM0808_IE_IMSI)[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI) {
LOGP(DMSC, LOGL_ERROR, "Wrong content in the IMSI\n");
return -1;
}
if (!TLVP_PRESENT(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST)) {
LOGP(DMSC, LOGL_ERROR, "Mandantory CELL IDENTIFIER LIST not present.\n");
return -1;
}
if (TLVP_PRESENT(&tp, GSM0808_IE_TMSI)) {
gsm48_mi_to_string(mi_string, sizeof(mi_string),
TLVP_VAL(&tp, GSM0808_IE_TMSI), TLVP_LEN(&tp, GSM0808_IE_TMSI));
tmsi = strtoul(mi_string, NULL, 10);
}
/*
* parse the IMSI
*/
gsm48_mi_to_string(mi_string, sizeof(mi_string),
TLVP_VAL(&tp, GSM0808_IE_IMSI), TLVP_LEN(&tp, GSM0808_IE_IMSI));
/*
* parse the cell identifier list
*/
data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
/*
* Support paging to all network or one BTS at one LAC
*/
if (data_length == 3 && data[0] == CELL_IDENT_LAC) {
lac = ntohs(read_data16(&data[1]));
} else if (data_length > 1 || (data[0] & 0x0f) != CELL_IDENT_BSS) {
LOGP(DMSC, LOGL_ERROR, "Unsupported Cell Identifier List: %s\n", hexdump(data, data_length));
return -1;
}
if (TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_NEEDED) && TLVP_LEN(&tp, GSM0808_IE_CHANNEL_NEEDED) == 1)
chan_needed = TLVP_VAL(&tp, GSM0808_IE_CHANNEL_NEEDED)[0] & 0x03;
if (TLVP_PRESENT(&tp, GSM0808_IE_EMLPP_PRIORITY)) {
LOGP(DMSC, LOGL_ERROR, "eMLPP is not handled\n");
}
LOGP(DMSC, LOGL_DEBUG, "Paging request from MSC IMSI: '%s' TMSI: '0x%x/%u' LAC: 0x%x\n", mi_string, tmsi, tmsi, lac);
LOGP(DMSC, LOGL_ERROR, "Paging is not implemented...\n");
return -1;
}
static int bssmap_rcvmsg_udt(struct gsm_network *net,
struct msgb *msg, unsigned int length)
{
int ret = 0;
if (length < 1) {
LOGP(DMSC, LOGL_ERROR, "Not enough room: %d\n", length);
return -1;
}
switch (msg->l4h[0]) {
case BSS_MAP_MSG_RESET_ACKNOWLEDGE:
ret = bssmap_handle_reset_ack(net, msg, length);
break;
case BSS_MAP_MSG_PAGING:
if (bsc_grace_allow_new_connection(net))
ret = bssmap_handle_paging(net, msg, length);
break;
}
return ret;
}
static int bssmap_rcvmsg_dt1(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int length)
{
return -1;
}
static int dtap_rcvmsg(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int length)
{
return -1;
}
int bsc_handle_udt(struct gsm_network *network,
struct bsc_msc_connection *conn,
struct msgb *msgb, unsigned int length)
{
struct bssmap_header *bs;
LOGP(DMSC, LOGL_DEBUG, "Incoming SCCP message ftom MSC: %s\n",
hexdump(msgb->l3h, length));
if (length < sizeof(*bs)) {
LOGP(DMSC, LOGL_ERROR, "The header is too short.\n");
return -1;
}
bs = (struct bssmap_header *) msgb->l3h;
if (bs->length < length - sizeof(*bs))
return -1;
switch (bs->type) {
case BSSAP_MSG_BSS_MANAGEMENT:
msgb->l4h = &msgb->l3h[sizeof(*bs)];
bssmap_rcvmsg_udt(network, msgb, length - sizeof(*bs));
break;
default:
LOGP(DMSC, LOGL_ERROR, "Unimplemented msg type: %d\n", bs->type);
}
return 0;
}
int bsc_handle_dt1(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int len)
{
if (len < sizeof(struct bssmap_header)) {
LOGP(DMSC, LOGL_ERROR, "The header is too short.\n");
}
switch (msg->l3h[0]) {
case BSSAP_MSG_BSS_MANAGEMENT:
msg->l4h = &msg->l3h[sizeof(struct bssmap_header)];
bssmap_rcvmsg_dt1(conn, msg, len - sizeof(struct bssmap_header));
break;
case BSSAP_MSG_DTAP:
dtap_rcvmsg(conn, msg, len);
break;
default:
LOGP(DMSC, LOGL_DEBUG, "Unimplemented msg type: %d\n", msg->l3h[0]);
}
return -1;
}
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