osmo-bsc/src/osmo-bsc/osmo_bsc_bssap.c

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/* GSM 08.08 BSSMAP handling */
/* (C) 2009-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2009-2012 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 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 Affero 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 <osmocom/bsc/osmo_bsc.h>
#include <osmocom/bsc/osmo_bsc_grace.h>
#include <osmocom/bsc/osmo_bsc_rf.h>
#include <osmocom/bsc/bsc_msc_data.h>
#include <osmocom/bsc/debug.h>
#include <osmocom/bsc/bsc_subscriber.h>
#include <osmocom/legacy_mgcp/mgcp.h>
#include <osmocom/bsc/osmo_bsc_mgcp.h>
#include <osmocom/bsc/paging.h>
#include <osmocom/bsc/gsm_04_08_utils.h>
#include <osmocom/gsm/protocol/gsm_08_08.h>
#include <osmocom/gsm/gsm0808.h>
#include <osmocom/gsm/gsm0808_utils.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/bsc/osmo_bsc_sigtran.h>
#include <osmocom/bsc/a_reset.h>
#include <osmocom/core/byteswap.h>
#define IP_V4_ADDR_LEN 4
/*
* helpers for the assignment command
*/
/* Helper function for match_codec_pref(), looks up a matching permitted speech
* value for a given msc audio codec pref */
enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support *audio)
{
if (audio->hr) {
switch (audio->ver) {
case 1:
return GSM0808_PERM_HR1;
break;
case 2:
return GSM0808_PERM_HR2;
break;
case 3:
return GSM0808_PERM_HR3;
break;
default:
LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
audio->ver);
return GSM0808_PERM_FR1;
}
} else {
switch (audio->ver) {
case 1:
return GSM0808_PERM_FR1;
break;
case 2:
return GSM0808_PERM_FR2;
break;
case 3:
return GSM0808_PERM_FR3;
break;
default:
LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
audio->ver);
return GSM0808_PERM_HR1;
}
}
}
/* Helper function for match_codec_pref(), looks up a matching chan mode for
* a given permitted speech value */
enum gsm48_chan_mode gsm88_to_chan_mode(enum gsm0808_permitted_speech speech)
{
switch (speech) {
case GSM0808_PERM_HR1:
case GSM0808_PERM_FR1:
return GSM48_CMODE_SPEECH_V1;
break;
case GSM0808_PERM_HR2:
case GSM0808_PERM_FR2:
return GSM48_CMODE_SPEECH_EFR;
break;
case GSM0808_PERM_HR3:
case GSM0808_PERM_FR3:
return GSM48_CMODE_SPEECH_AMR;
break;
default:
LOGP(DMSC, LOGL_FATAL,
"Unsupported permitted speech selected, assuming AMR as channel mode...\n");
return GSM48_CMODE_SPEECH_AMR;
}
}
/* Helper function for match_codec_pref(), tests if a given audio support
* matches one of the permitted speech settings of the channel type element.
* The matched permitted speech value is then also compared against the
* speech codec list. (optional, only relevant for AoIP) */
static bool test_codec_pref(const struct gsm0808_channel_type *ct,
const struct gsm0808_speech_codec_list *scl,
uint8_t perm_spch)
{
unsigned int i;
bool match = false;
struct gsm0808_speech_codec sc;
int rc;
/* Try to finde the given permitted speech value in the
* codec list of the channel type element */
for (i = 0; i < ct->perm_spch_len; i++) {
if (ct->perm_spch[i] == perm_spch) {
match = true;
break;
}
}
/* If we do not have a speech codec list to test against,
* we just exit early (will be always the case in non-AoIP networks) */
if (!scl)
return match;
/* If we failed to match until here, there is no
* point in testing further */
if (match == false)
return false;
/* Extrapolate speech codec data */
rc = gsm0808_speech_codec_from_chan_type(&sc, perm_spch);
if (rc < 0)
return false;
/* Try to find extrapolated speech codec data in
* the speech codec list */
for (i = 0; i < scl->len; i++) {
if (memcmp(&sc, &scl->codec[i], sizeof(sc)) == 0)
return true;
}
return false;
}
/* Helper function for bssmap_handle_assignm_req(), matches the codec
* preferences from the MSC with the codec preferences */
static int match_codec_pref(int *full_rate, enum gsm48_chan_mode *chan_mode,
const struct gsm0808_channel_type *ct,
const struct gsm0808_speech_codec_list *scl,
const struct bsc_msc_data *msc)
{
unsigned int i;
uint8_t perm_spch;
bool match = false;
for (i = 0; i < msc->audio_length; i++) {
perm_spch = audio_support_to_gsm88(msc->audio_support[i]);
if (test_codec_pref(ct, scl, perm_spch)) {
match = true;
break;
}
}
/* Exit without result, in case no match can be deteched */
if (!match) {
*full_rate = -1;
*chan_mode = GSM48_CMODE_SIGN;
return -1;
}
/* Check if the result is a half or full rate codec */
if (perm_spch == GSM0808_PERM_HR1 || perm_spch == GSM0808_PERM_HR2
|| perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_HR4
|| perm_spch == GSM0808_PERM_HR6)
*full_rate = 0;
else
*full_rate = 1;
/* Lookup a channel mode for the selected codec */
*chan_mode = gsm88_to_chan_mode(perm_spch);
return 0;
}
static int bssmap_handle_reset_ack(struct bsc_msc_data *msc,
struct msgb *msg, unsigned int length)
{
LOGP(DMSC, LOGL_NOTICE, "RESET ACK from MSC: %s\n",
osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance),
&msc->a.msc_addr));
/* Inform the FSM that controls the RESET/RESET-ACK procedure
* that we have successfully received the reset-ack message */
a_reset_ack_confirm(msc->a.reset);
return 0;
}
/* Handle MSC sided reset */
static int bssmap_handle_reset(struct bsc_msc_data *msc,
struct msgb *msg, unsigned int length)
{
LOGP(DMSC, LOGL_NOTICE, "RESET from MSC: %s\n",
osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance),
&msc->a.msc_addr));
/* Instruct the bsc to close all open sigtran connections and to
* close all active channels on the BTS side as well */
osmo_bsc_sigtran_reset(msc);
/* Inform the MSC that we have received the reset request and
* that we acted accordingly */
osmo_bsc_sigtran_tx_reset_ack(msc);
return 0;
}
/* GSM 08.08 § 3.2.1.19 */
static int bssmap_handle_paging(struct bsc_msc_data *msc,
struct msgb *msg, unsigned int payload_length)
{
struct bsc_subscr *subscr;
struct tlv_parsed tp;
char mi_string[GSM48_MI_SIZE];
uint32_t tmsi = GSM_RESERVED_TMSI;
unsigned int lac;
uint8_t data_length;
const uint8_t *data;
uint8_t chan_needed = RSL_CHANNEED_ANY;
uint8_t cell_ident;
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, "Mandatory 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, "Mandatory CELL IDENTIFIER LIST not present.\n");
return -1;
}
if (TLVP_PRESENT(&tp, GSM0808_IE_TMSI) &&
TLVP_LEN(&tp, GSM0808_IE_TMSI) == 4) {
tmsi = ntohl(tlvp_val32_unal(&tp, GSM0808_IE_TMSI));
}
/*
* parse the IMSI
*/
gsm48_mi_to_string(mi_string, sizeof(mi_string),
TLVP_VAL(&tp, GSM0808_IE_IMSI), TLVP_LEN(&tp, GSM0808_IE_IMSI));
/*
* There are various cell identifier list types defined at 3GPP TS § 08.08, we don't support all
* of them yet. To not disrupt paging operation just because we're lacking some implementation,
* interpret any unknown cell identifier type as "page the entire BSS".
*/
data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
if (data_length < 1) {
LOGP(DMSC, LOGL_ERROR, "Paging IMSI %s: Zero length Cell Identifier List\n",
mi_string);
return -1;
}
cell_ident = data[0] & 0xf;
/* Default fallback: page entire BSS */
lac = GSM_LAC_RESERVED_ALL_BTS;
switch (cell_ident) {
case CELL_IDENT_LAC:
if (data_length != 3) {
LOGP(DMSC, LOGL_ERROR, "Paging IMSI %s: Cell Identifier List for LAC (0x%x)"
" has invalid length: %u, paging entire BSS instead (%s)\n",
mi_string, CELL_IDENT_LAC, data_length, osmo_hexdump(data, data_length));
break;
}
lac = osmo_load16be(&data[1]);
break;
case CELL_IDENT_BSS:
if (data_length != 1) {
LOGP(DMSC, LOGL_ERROR, "Paging IMSI %s: Cell Identifier List for BSS (0x%x)"
" has invalid length: %u, paging entire BSS anyway (%s)\n",
mi_string, CELL_IDENT_BSS, data_length, osmo_hexdump(data, data_length));
}
break;
default:
LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: unimplemented Cell Identifier List (0x%x),"
" paging entire BSS instead (%s)\n",
mi_string, cell_ident, osmo_hexdump(data, data_length));
break;
}
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");
}
subscr = bsc_subscr_find_or_create_by_imsi(msc->network->bsc_subscribers,
mi_string);
if (!subscr) {
LOGP(DMSC, LOGL_ERROR, "Failed to allocate a subscriber for %s\n", mi_string);
return -1;
}
subscr->lac = lac;
subscr->tmsi = tmsi;
LOGP(DMSC, LOGL_INFO, "Paging request from MSC IMSI: '%s' TMSI: '0x%x/%u' LAC: 0x%x\n", mi_string, tmsi, tmsi, lac);
bsc_grace_paging_request(msc->network->bsc_data->rf_ctrl->policy,
subscr, chan_needed, msc);
return 0;
}
/*
* GSM 08.08 § 3.1.9.1 and 3.2.1.21...
* release our gsm_subscriber_connection and send message
*/
static int bssmap_handle_clear_command(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int payload_length)
{
struct msgb *resp;
/* TODO: handle the cause of this package */
if (conn->conn) {
LOGP(DMSC, LOGL_INFO, "Releasing all transactions on %p\n", conn);
gsm0808_clear(conn->conn);
bsc_subscr_con_free(conn->conn);
conn->conn = NULL;
}
/* generate the clear complete message */
resp = gsm0808_create_clear_complete();
if (!resp) {
LOGP(DMSC, LOGL_ERROR, "Sending clear complete failed.\n");
return -1;
}
if (conn->mgcp_ctx) {
/* NOTE: This is the AoIP case, osmo-bsc has to negotiate with
* the MGCP-GW. For this an mgcp_ctx should be created that
* contains the FSM and some system data. When the connection
* is removed from the MGCP-GW, then osmo_bsc_sigtran_send()
* calls osmo_bsc_sigtran_send(). */
mgcp_clear_complete(conn->mgcp_ctx, resp);
} else {
/* NOTE: This is the SCCP-Lite case, since we do not handle
* the MGCP-GW switching ourselves, we may skip everything
* that is MGCP-GW related and sent the clear complete message
* directly */
osmo_bsc_sigtran_send(conn, resp);
}
return 0;
}
/*
* GSM 08.08 § 3.4.7 cipher mode handling. We will have to pick
* the cipher to be used for this. In case we are already using
* a cipher we will have to send cipher mode reject to the MSC,
* otherwise we will have to pick something that we and the MS
* is supporting. Currently we are doing it in a rather static
* way by picking one ecnryption or no encrytpion.
*/
static int bssmap_handle_cipher_mode(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int payload_length)
{
uint16_t len;
struct gsm_network *network = NULL;
const uint8_t *data;
struct tlv_parsed tp;
struct msgb *resp;
int reject_cause = -1;
int include_imeisv = 1;
if (!conn->conn) {
LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");
goto reject;
}
if (conn->ciphering_handled) {
LOGP(DMSC, LOGL_ERROR, "Already seen ciphering command. Protocol Error.\n");
goto reject;
}
conn->ciphering_handled = 1;
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, payload_length - 1, 0, 0);
if (!TLVP_PRESENT(&tp, GSM0808_IE_ENCRYPTION_INFORMATION)) {
LOGP(DMSC, LOGL_ERROR, "IE Encryption Information missing.\n");
goto reject;
}
/*
* check if our global setting is allowed
* - Currently we check for A5/0 and A5/1
* - Copy the key if that is necessary
* - Otherwise reject
*/
len = TLVP_LEN(&tp, GSM0808_IE_ENCRYPTION_INFORMATION);
if (len < 1) {
LOGP(DMSC, LOGL_ERROR, "IE Encryption Information is too short.\n");
goto reject;
}
network = conn->conn->bts->network;
data = TLVP_VAL(&tp, GSM0808_IE_ENCRYPTION_INFORMATION);
if (TLVP_PRESENT(&tp, GSM0808_IE_CIPHER_RESPONSE_MODE))
include_imeisv = TLVP_VAL(&tp, GSM0808_IE_CIPHER_RESPONSE_MODE)[0] & 0x1;
if (network->a5_encryption == 0 && (data[0] & 0x1) == 0x1) {
gsm0808_cipher_mode(conn->conn, 0, NULL, 0, include_imeisv);
} else if (network->a5_encryption != 0 && (data[0] & 0x2) == 0x2) {
gsm0808_cipher_mode(conn->conn, 1, &data[1], len - 1, include_imeisv);
} else {
LOGP(DMSC, LOGL_ERROR, "Can not select encryption...\n");
goto reject;
}
return 0;
reject:
resp = gsm0808_create_cipher_reject(reject_cause);
if (!resp) {
LOGP(DMSC, LOGL_ERROR, "Sending the cipher reject failed.\n");
return -1;
}
osmo_bsc_sigtran_send(conn, resp);
return -1;
}
/*
* Handle the assignment request message.
*
* See §3.2.1.1 for the message type
*/
static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int length)
{
struct msgb *resp;
struct bsc_msc_data *msc;
struct tlv_parsed tp;
uint8_t timeslot = 0;
uint8_t multiplex = 0;
enum gsm48_chan_mode chan_mode = GSM48_CMODE_SIGN;
int port, full_rate = -1;
bool aoip = false;
struct sockaddr_storage rtp_addr;
struct gsm0808_channel_type ct;
struct gsm0808_speech_codec_list scl;
struct gsm0808_speech_codec_list *scl_ptr = NULL;
int rc;
const uint8_t *data;
char len;
if (!conn->conn) {
LOGP(DMSC, LOGL_ERROR,
"No lchan/msc_data in cipher mode command.\n");
return -1;
}
msc = conn->msc;
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0);
/* Check for channel type element, if its missing, immediately reject */
if (!TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_TYPE)) {
LOGP(DMSC, LOGL_ERROR, "Mandatory channel type not present.\n");
goto reject;
}
/* Detect if a CIC code is present, if so, we use the classic ip.access
* method to calculate the RTP port */
if (TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) {
conn->cic =
osmo_load16be(TLVP_VAL
(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE));
timeslot = conn->cic & 0x1f;
multiplex = (conn->cic & ~0x1f) >> 5;
} else if (TLVP_PRESENT(&tp, GSM0808_IE_AOIP_TRASP_ADDR)) {
/* Decode AoIP transport address element */
data = TLVP_VAL(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
len = TLVP_LEN(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, data, len);
if (rc < 0) {
LOGP(DMSC, LOGL_ERROR,
"Unable to decode aoip transport address.\n");
goto reject;
}
aoip = true;
} else {
LOGP(DMSC, LOGL_ERROR,
"transport address missing. Audio routing will not work.\n");
goto reject;
}
/* Decode speech codec list (AoIP) */
if (aoip) {
/* Check for speech codec list element */
if (!TLVP_PRESENT(&tp, GSM0808_IE_SPEECH_CODEC_LIST)) {
LOGP(DMSC, LOGL_ERROR,
"Mandatory speech codec list not present.\n");
goto reject;
}
/* Decode Speech Codec list */
data = TLVP_VAL(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
len = TLVP_LEN(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
rc = gsm0808_dec_speech_codec_list(&scl, data, len);
if (rc < 0) {
LOGP(DMSC, LOGL_ERROR,
"Unable to decode speech codec list\n");
goto reject;
}
scl_ptr = &scl;
}
/* Decode Channel Type element */
data = TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
len = TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE);
rc = gsm0808_dec_channel_type(&ct, data, len);
if (rc < 0) {
LOGP(DMSC, LOGL_ERROR, "unable to decode channel type.\n");
goto reject;
}
/* Currently we only support a limited subset of all
* possible channel types. The limitation ends by not using
* multi-slot, limiting the channel coding to speech */
if (ct.ch_indctr != GSM0808_CHAN_SPEECH) {
LOGP(DMSC, LOGL_ERROR,
"Unsupported channel type, currently only speech is supported!\n");
goto reject;
}
/* Match codec information from the assignment command against the
* local preferences of the BSC */
rc = match_codec_pref(&full_rate, &chan_mode, &ct, scl_ptr, msc);
if (rc < 0) {
LOGP(DMSC, LOGL_ERROR, "No supported audio type found for channel_type ="
" { ch_indctr=0x%x, ch_rate_type=0x%x, perm_spch=[ %s] }\n",
ct.ch_indctr, ct.ch_rate_type, osmo_hexdump(ct.perm_spch, ct.perm_spch_len));
/* TODO: actually output codec names, e.g. implement gsm0808_permitted_speech_names[] and
* iterate perm_spch. */
goto reject;
}
DEBUGP(DMSC, "Found matching audio type: %s %s for channel_type ="
" { ch_indctr=0x%x, ch_rate_type=0x%x, perm_spch=[ %s] }\n",
full_rate? "full rate" : "half rate",
get_value_string(gsm48_chan_mode_names, chan_mode),
ct.ch_indctr, ct.ch_rate_type, osmo_hexdump(ct.perm_spch, ct.perm_spch_len));
/* Forward the assingment request to lower layers */
if (aoip) {
/* Store network side RTP connection information, we will
* process this address later after we have established an RTP
* connection to the BTS. This is just for organizational
* reasons, functional wise it would not matter when exactly
* the network side RTP connection is made, as long it is made
* before we return with the assignment complete message. */
memcpy(&conn->aoip_rtp_addr_remote, &rtp_addr, sizeof(rtp_addr));
/* Create an assignment request using the MGCP fsm. This FSM
* is directly started when its created (now) and will also
* take care about the further processing (creating RTP
* endpoints, calling gsm0808_assign_req(), rsponding to
* the assignment request etc... */
conn->mgcp_ctx = mgcp_assignm_req(msc->network, msc->network->mgw.client, conn, chan_mode, full_rate);
if (!conn->mgcp_ctx) {
LOGP(DMSC, LOGL_ERROR, "MGCP GW failure, rejecting assignment... (id=%i)\n", conn->conn_id);
goto reject;
}
/* We now may return here, the FSM will do all further work */
return 0;
} else {
/* Note: In the sccp-lite case we to not perform any mgcp operation,
* (the MSC does that for us). We set conn->rtp_ip to 0 and check
* on this later. By this we know that we have to behave accordingly
* to sccp-lite. */
port = mgcp_timeslot_to_endpoint(multiplex, timeslot);
conn->rtp_port = rtp_calculate_port(port, msc->rtp_base);
conn->rtp_ip = 0;
return gsm0808_assign_req(conn->conn, chan_mode, full_rate);
}
reject:
resp =
gsm0808_create_assignment_failure
(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
if (!resp) {
LOGP(DMSC, LOGL_ERROR, "Channel allocation failure.\n");
return -1;
}
osmo_bsc_sigtran_send(conn, resp);
return -1;
}
static int bssmap_rcvmsg_udt(struct bsc_msc_data *msc,
struct msgb *msg, unsigned int length)
{
int ret = 0;
if (length < 1) {
LOGP(DMSC, LOGL_ERROR, "Not enough room: %d\n", length);
return -1;
}
LOGP(DMSC, LOGL_INFO, "Rx MSC UDT BSSMAP %s\n",
gsm0808_bssmap_name(msg->l4h[0]));
switch (msg->l4h[0]) {
case BSS_MAP_MSG_RESET_ACKNOWLEDGE:
ret = bssmap_handle_reset_ack(msc, msg, length);
break;
case BSS_MAP_MSG_RESET:
ret = bssmap_handle_reset(msc, msg, length);
break;
case BSS_MAP_MSG_PAGING:
ret = bssmap_handle_paging(msc, msg, length);
break;
default:
LOGP(DMSC, LOGL_NOTICE, "Received unimplemented BSSMAP UDT %s\n",
gsm0808_bssmap_name(msg->l4h[0]));
break;
}
return ret;
}
static int bssmap_rcvmsg_dt1(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int length)
{
int ret = 0;
if (length < 1) {
LOGP(DMSC, LOGL_ERROR, "Not enough room: %d\n", length);
return -1;
}
LOGP(DMSC, LOGL_INFO, "Rx MSC DT1 BSSMAP %s\n",
gsm0808_bssmap_name(msg->l4h[0]));
switch (msg->l4h[0]) {
case BSS_MAP_MSG_CLEAR_CMD:
ret = bssmap_handle_clear_command(conn, msg, length);
break;
case BSS_MAP_MSG_CIPHER_MODE_CMD:
ret = bssmap_handle_cipher_mode(conn, msg, length);
break;
case BSS_MAP_MSG_ASSIGMENT_RQST:
ret = bssmap_handle_assignm_req(conn, msg, length);
break;
default:
LOGP(DMSC, LOGL_NOTICE, "Unimplemented msg type: %s\n",
gsm0808_bssmap_name(msg->l4h[0]));
break;
}
return ret;
}
static int dtap_rcvmsg(struct osmo_bsc_sccp_con *conn,
struct msgb *msg, unsigned int length)
{
struct dtap_header *header;
struct msgb *gsm48;
uint8_t *data;
int rc, dtap_rc;
LOGP(DMSC, LOGL_DEBUG, "Rx MSC DTAP: %s\n",
osmo_hexdump(msg->l3h, length));
if (!conn->conn) {
LOGP(DMSC, LOGL_ERROR, "No subscriber connection available\n");
return -1;
}
header = (struct dtap_header *) msg->l3h;
if (sizeof(*header) >= length) {
LOGP(DMSC, LOGL_ERROR, "The DTAP header does not fit. Wanted: %zu got: %u\n", sizeof(*header), length);
LOGP(DMSC, LOGL_ERROR, "hex: %s\n", osmo_hexdump(msg->l3h, length));
return -1;
}
if (header->length > length - sizeof(*header)) {
LOGP(DMSC, LOGL_ERROR, "The DTAP l4 information does not fit: header: %u length: %u\n", header->length, length);
LOGP(DMSC, LOGL_ERROR, "hex: %s\n", osmo_hexdump(msg->l3h, length));
return -1;
}
LOGP(DMSC, LOGL_INFO, "Rx MSC DTAP, SAPI: %u CHAN: %u\n", header->link_id & 0x07, header->link_id & 0xC0);
/* forward the data */
gsm48 = gsm48_msgb_alloc_name("GSM 04.08 DTAP RCV");
if (!gsm48) {
LOGP(DMSC, LOGL_ERROR, "Allocation of the message failed.\n");
return -1;
}
gsm48->l3h = gsm48->data;
data = msgb_put(gsm48, length - sizeof(*header));
memcpy(data, msg->l3h + sizeof(*header), length - sizeof(*header));
/* pass it to the filter for extra actions */
rc = bsc_scan_msc_msg(conn->conn, gsm48);
dtap_rc = gsm0808_submit_dtap(conn->conn, gsm48, header->link_id, 1);
if (rc == BSS_SEND_USSD)
bsc_send_welcome_ussd(conn->conn);
return dtap_rc;
}
int bsc_handle_udt(struct bsc_msc_data *msc,
struct msgb *msgb, unsigned int length)
{
struct bssmap_header *bs;
LOGP(DMSC, LOGL_DEBUG, "Rx MSC UDT: %s\n",
osmo_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(msc, msgb, length - sizeof(*bs));
break;
default:
LOGP(DMSC, LOGL_NOTICE, "Unimplemented msg type: %s\n",
gsm0808_bssmap_name(bs->type));
}
return 0;
}
int bsc_handle_dt(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_NOTICE, "Unimplemented BSSAP msg type: %s\n",
gsm0808_bssap_name(msg->l3h[0]));
}
return -1;
}
/* Generate and send assignment complete message */
int bssmap_send_aoip_ass_compl(struct gsm_lchan *lchan)
{
struct msgb *resp;
struct gsm0808_speech_codec sc;
struct gsm_subscriber_connection *conn;
conn = lchan->conn;
OSMO_ASSERT(lchan->abis_ip.ass_compl.valid);
OSMO_ASSERT(conn);
OSMO_ASSERT(conn->sccp_con);
LOGP(DMSC, LOGL_DEBUG, "Sending assignment complete message... (id=%i)\n", conn->sccp_con->conn_id);
/* Extrapolate speech codec from speech mode */
gsm0808_speech_codec_from_chan_type(&sc, lchan->abis_ip.ass_compl.speech_mode);
/* Generate message */
resp = gsm0808_create_ass_compl(lchan->abis_ip.ass_compl.rr_cause,
lchan->abis_ip.ass_compl.chosen_channel,
lchan->abis_ip.ass_compl.encr_alg_id,
lchan->abis_ip.ass_compl.speech_mode,
&conn->sccp_con->aoip_rtp_addr_local,
&sc,
NULL);
if (!resp) {
LOGP(DMSC, LOGL_ERROR, "Failed to generate assignment completed message! (id=%i)\n",
conn->sccp_con->conn_id);
return -EINVAL;
}
return osmo_bsc_sigtran_send(conn->sccp_con, resp);
}