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bsc: Implement the assignment command to the point of calling into the BSC API

This commit is contained in:
Holger Hans Peter Freyther 2010-11-10 10:07:30 +01:00
parent fae3c65938
commit 50c579b8c5
2 changed files with 179 additions and 0 deletions
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1
openbsc/include/openbsc/osmo_bsc.h
View File

@ -11,6 +11,7 @@ struct osmo_bsc_sccp_con {
struct llist_head entry;
int ciphering_handled;
int rtp_port;
/* SCCP connection realted */
struct sccp_connection *sccp;

178
openbsc/src/bsc/osmo_bsc_bssap.c
View File

@ -21,7 +21,9 @@
#include <openbsc/osmo_bsc.h>
#include <openbsc/osmo_bsc_grace.h>
#include <openbsc/osmo_msc_data.h>
#include <openbsc/debug.h>
#include <openbsc/mgcp.h>
#include <osmocore/gsm0808.h>
#include <osmocore/protocol/gsm_08_08.h>
@ -36,6 +38,65 @@ static uint16_t read_data16(const uint8_t *data)
return res;
}
/*
* helpers for the assignment command
*/
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;
}
}
}
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;
}
LOGP(DMSC, LOGL_FATAL, "Should not be reached.\n");
return GSM48_CMODE_SPEECH_AMR;
}
static int bssmap_handle_reset_ack(struct gsm_network *net,
struct msgb *msg, unsigned int length)
{
@ -215,6 +276,120 @@ reject:
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 gsm_network *network;
struct tlv_parsed tp;
uint8_t *data;
uint16_t cic;
uint8_t timeslot;
uint8_t multiplex;
enum gsm48_chan_mode chan_mode = GSM48_CMODE_SIGN;
int i, supported, port, full_rate = -1;
if (!conn->conn) {
LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");
return -1;
}
network = conn->conn->bts->network;
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0);
if (!TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_TYPE)) {
LOGP(DMSC, LOGL_ERROR, "Mandantory channel type not present.\n");
goto reject;
}
if (!TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) {
LOGP(DMSC, LOGL_ERROR, "Identity code missing. Audio routing will not work.\n");
goto reject;
}
cic = ntohs(read_data16(TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)));
timeslot = cic & 0x1f;
multiplex = (cic & ~0x1f) >> 5;
/*
* Currently we only support a limited subset of all
* possible channel types. The limitation ends by not using
* multi-slot, limiting the channel coding, speech...
*/
if (TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE) < 3) {
LOGP(DMSC, LOGL_ERROR, "ChannelType len !=3 not supported: %d\n",
TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE));
goto reject;
}
/*
* Try to figure out if we support the proposed speech codecs. For
* now we will always pick the full rate codecs.
*/
data = (uint8_t *) TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
if ((data[0] & 0xf) != 0x1) {
LOGP(DMSC, LOGL_ERROR, "ChannelType != speech: %d\n", data[0]);
goto reject;
}
if (data[1] != GSM0808_SPEECH_FULL_PREF && data[1] != GSM0808_SPEECH_HALF_PREF) {
LOGP(DMSC, LOGL_ERROR, "ChannelType full not allowed: %d\n", data[1]);
goto reject;
}
/*
* go through the list of preferred codecs of our gsm network
* and try to find it among the permitted codecs. If we found
* it we will send chan_mode to the right mode and break the
* inner loop. The outer loop will exit due chan_mode having
* the correct value.
*/
full_rate = 0;
for (supported = 0;
chan_mode == GSM48_CMODE_SIGN && supported < network->msc_data->audio_length;
++supported) {
int perm_val = audio_support_to_gsm88(network->msc_data->audio_support[supported]);
for (i = 2; i < TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE); ++i) {
if ((data[i] & 0x7f) == perm_val) {
chan_mode = gsm88_to_chan_mode(perm_val);
full_rate = (data[i] & 0x4) == 0;
break;
} else if ((data[i] & 0x80) == 0x00) {
break;
}
}
}
if (chan_mode == GSM48_CMODE_SIGN) {
LOGP(DMSC, LOGL_ERROR, "No supported audio type found.\n");
goto reject;
}
/* map it to a MGCP Endpoint and a RTP port */
port = mgcp_timeslot_to_endpoint(multiplex, timeslot);
conn->rtp_port = rtp_calculate_port(port,
network->msc_data->rtp_base);
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;
}
bsc_queue_for_msc(conn, resp);
return -1;
}
static int bssmap_rcvmsg_udt(struct gsm_network *net,
struct msgb *msg, unsigned int length)
{
@ -255,6 +430,9 @@ static int bssmap_rcvmsg_dt1(struct osmo_bsc_sccp_con *conn,
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_DEBUG, "Unimplemented msg type: %d\n", msg->l4h[0]);
break;