bsc_api: Add some more comments to the code
diff --git a/openbsc/src/libbsc/bsc_api.c b/openbsc/src/libbsc/bsc_api.c
index 9504e53..c1aedb2 100644
--- a/openbsc/src/libbsc/bsc_api.c
+++ b/openbsc/src/libbsc/bsc_api.c
@@ -270,6 +270,7 @@
return 0;
}
+/*! \brief process incoming 08.08 DTAP from MSC (send via BTS to MS) */
int gsm0808_submit_dtap(struct gsm_subscriber_connection *conn,
struct msgb *msg, int link_id, int allow_sach)
{
@@ -294,7 +295,9 @@
}
msg->l3h = msg->data;
+ /* is requested SAPI already up? */
if (conn->lchan->sapis[sapi] == LCHAN_SAPI_UNUSED) {
+ /* Establish L2 for additional SAPI */
OBSC_LINKID_CB(msg) = link_id;
if (rll_establish(msg->lchan, sapi, rll_ind_cb, msg) != 0) {
msgb_free(msg);
@@ -303,6 +306,7 @@
}
return 0;
} else {
+ /* Directly forward via RLL/RSL to BTS */
return rsl_data_request(msg, link_id);
}
}
@@ -469,6 +473,7 @@
api->dtap(conn, link_id, msg);
}
+/*! \brief RSL has received a DATA INDICATION with L3 from MS */
int gsm0408_rcvmsg(struct msgb *msg, uint8_t link_id)
{
int rc;
@@ -484,8 +489,11 @@
if (lchan->conn) {
+ /* if we already have a connection, forward via DTAP to
+ * MSC */
dispatch_dtap(lchan->conn, link_id, msg);
} else {
+ /* allocate a new connection */
rc = BSC_API_CONN_POL_REJECT;
lchan->conn = subscr_con_allocate(msg->lchan);
if (!lchan->conn) {
@@ -493,6 +501,7 @@
return -1;
}
+ /* fwd via bsc_api to send COMPLETE L3 INFO to MSC */
rc = api->compl_l3(lchan->conn, msg, 0);
if (rc != BSC_API_CONN_POL_ACCEPT) {
@@ -505,6 +514,7 @@
return 0;
}
+/*! \brief We received a GSM 08.08 CIPHER MODE from the MSC */
int gsm0808_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
const uint8_t *key, int len, int include_imeisv)
{