cellular-infrastructure
/
osmo-bsc
mirror of https://gerrit.osmocom.org/osmo-bsc
9
0
Fork 0
Code Issues Releases Wiki Activity

HO: add queue to cache DTAP messages during handover/assignment 

Add ho_dtap_cache to gsm_subscriber_connection, a stock msgb queue to be used
with msgb_enqueue() and msgb_dequeue().

Keep a counter of queue length, to enforce a sane maximum counter for cached
messages. So far a hardcoded maximum of 23 messages will be cached.

Have balanced ho_dtap_cache_add() and ho_dtap_cache_flush() functions.

The original patch was by jolly, but I have basically completely replaced it
with the simpler msgb queue pattern.

Change-Id: I6e4d93628befb3d97e5cee0343cd9f8ba0b8620c
This commit is contained in:
Andreas Eversberg 2013-06-17 11:58:30 +02:00 committed by Harald Welte
parent 2660c0412d
commit 935e5d76dd
2 changed files with 77 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/osmocom/bsc/gsm_data.h
View File

@ -100,6 +100,10 @@ struct gsm_subscriber_connection {
/* buffer/cache for classmark of the ME of the subscriber */
struct gsm_classmark classmark;
/* Cache DTAP messages during handover/assignment (msgb_enqueue()/msgb_dequeue())*/
struct llist_head ho_dtap_cache;
unsigned int ho_dtap_cache_len;
};
static inline struct gsm_bts *conn_get_bts(struct gsm_subscriber_connection *conn) {

73
src/libbsc/bsc_api.c
View File

@ -39,6 +39,8 @@
#define GSM0808_T10_VALUE 6, 0
#define HO_DTAP_CACHE_MSGB_CB_LINK_ID 0
#define HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH 1
static void rll_ind_cb(struct gsm_lchan *, uint8_t, void *, enum bsc_rllr_ind);
static void send_sapi_reject(struct gsm_subscriber_connection *conn, int link_id);
@ -274,10 +276,54 @@ struct gsm_subscriber_connection *bsc_subscr_con_allocate(struct gsm_lchan *lcha
conn->lchan = lchan;
conn->bts = lchan->ts->trx->bts;
lchan->conn = conn;
INIT_LLIST_HEAD(&conn->ho_dtap_cache);
llist_add_tail(&conn->entry, &net->subscr_conns);
return conn;
}
static void ho_dtap_cache_add(struct gsm_subscriber_connection *conn, struct msgb *msg,
int link_id, bool allow_sacch)
{
if (conn->ho_dtap_cache_len >= 23) {
LOGP(DHO, LOGL_ERROR, "%s: Cannot cache more DTAP messages,"
" already reached sane maximum of %u cached messages\n",
bsc_subscr_name(conn->bsub), conn->ho_dtap_cache_len);
msgb_free(msg);
return;
}
conn->ho_dtap_cache_len ++;
LOGP(DHO, LOGL_DEBUG, "%s: Caching DTAP message during ho/ass (%u)\n",
bsc_subscr_name(conn->bsub), conn->ho_dtap_cache_len);
msg->cb[HO_DTAP_CACHE_MSGB_CB_LINK_ID] = (unsigned long)link_id;
msg->cb[HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH] = allow_sacch ? 1 : 0;
msgb_enqueue(&conn->ho_dtap_cache, msg);
}
static void ho_dtap_cache_flush(struct gsm_subscriber_connection *conn, int send)
{
struct msgb *msg;
unsigned int flushed_count = 0;
if (conn->secondary_lchan || conn->ho_lchan) {
LOGP(DHO, LOGL_ERROR, "%s: Cannot send cached DTAP messages, handover/assignment is still ongoing\n",
bsc_subscr_name(conn->bsub));
send = 0;
}
while ((msg = msgb_dequeue(&conn->ho_dtap_cache))) {
conn->ho_dtap_cache_len --;
flushed_count ++;
if (send) {
int link_id = (int)msg->cb[HO_DTAP_CACHE_MSGB_CB_LINK_ID];
bool allow_sacch = !!msg->cb[HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH];
LOGP(DHO, LOGL_DEBUG, "%s: Sending cached DTAP message after handover/assignment (%u/%u)\n",
bsc_subscr_name(conn->bsub), flushed_count, conn->ho_dtap_cache_len);
gsm0808_submit_dtap(conn, msg, link_id, allow_sacch);
} else
msgb_free(msg);
}
}
void bsc_subscr_con_free(struct gsm_subscriber_connection *conn)
{
if (!conn)
@ -301,6 +347,9 @@ void bsc_subscr_con_free(struct gsm_subscriber_connection *conn)
conn->secondary_lchan->conn = NULL;
}
/* drop pending messages */
ho_dtap_cache_flush(conn, 0);
llist_del(&conn->entry);
talloc_free(conn);
}
@ -325,6 +374,12 @@ int gsm0808_submit_dtap(struct gsm_subscriber_connection *conn,
return -1;
}
/* buffer message during assignment / handover */
if (conn->secondary_lchan || conn->ho_lchan) {
ho_dtap_cache_add(conn, msg, link_id, !! allow_sacch);
return 0;
}
sapi = link_id & 0x7;
msg->lchan = conn->lchan;
msg->dst = msg->lchan->ts->trx->rsl_link;
@ -458,6 +513,9 @@ static void handle_ass_compl(struct gsm_subscriber_connection *conn,
osmo_signal_dispatch(SS_LCHAN, S_LCHAN_ASSIGNMENT_COMPL, &sig);
/* FIXME: release old channel */
/* send pending messages, if any */
ho_dtap_cache_flush(conn, 1);
return;
}
@ -480,6 +538,9 @@ static void handle_ass_compl(struct gsm_subscriber_connection *conn,
conn->lchan = conn->secondary_lchan;
conn->secondary_lchan = NULL;
/* send pending messages, if any */
ho_dtap_cache_flush(conn, 1);
if (is_ipaccess_bts(conn_get_bts(conn)) && conn->lchan->tch_mode != GSM48_CMODE_SIGN)
rsl_ipacc_crcx(conn->lchan);
@ -508,6 +569,9 @@ static void handle_ass_fail(struct gsm_subscriber_connection *conn,
osmo_signal_dispatch(SS_LCHAN, S_LCHAN_ASSIGNMENT_FAIL, &sig);
/* FIXME: release allocated new channel */
/* send pending messages, if any */
ho_dtap_cache_flush(conn, 1);
return;
}
@ -523,6 +587,9 @@ static void handle_ass_fail(struct gsm_subscriber_connection *conn,
conn->secondary_lchan = NULL;
}
/* send pending messages, if any */
ho_dtap_cache_flush(conn, 1);
gh = msgb_l3(msg);
if (msgb_l3len(msg) - sizeof(*gh) != 1) {
LOGP(DMSC, LOGL_ERROR, "assignment failure unhandled: %zu\n",
@ -588,6 +655,9 @@ static void handle_rr_ho_compl(struct msgb *msg)
sig.mr = NULL;
osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_COMPL, &sig);
/* FIXME: release old channel */
/* send pending messages, if any */
ho_dtap_cache_flush(msg->lchan->conn, 1);
}
/* Chapter 9.1.17 Handover Failure */
@ -603,6 +673,9 @@ static void handle_rr_ho_fail(struct msgb *msg)
sig.mr = NULL;
osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_FAIL, &sig);
/* FIXME: release allocated new channel */
/* send pending messages, if any */
ho_dtap_cache_flush(msg->lchan->conn, 1);
}