Handle and dispatch paging requests in gsm_subscriber
Implement subscr_get_channel and subscr_put_channel to
a degree that SMS Submit and phone call scheduled at the
same time will deliver both (one after the other).
diff --git a/openbsc/src/gsm_subscriber.c b/openbsc/src/gsm_subscriber.c
index 3a81793..3062a6b 100644
--- a/openbsc/src/gsm_subscriber.c
+++ b/openbsc/src/gsm_subscriber.c
@@ -25,15 +25,77 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#include <assert.h>
#include <openbsc/gsm_subscriber.h>
#include <openbsc/paging.h>
#include <openbsc/debug.h>
+#include <openbsc/paging.h>
#include <openbsc/db.h>
-
LLIST_HEAD(active_subscribers);
+/*
+ * Struct for pending channel requests. This is managed in the
+ * llist_head requests of each subscriber. The reference counting
+ * should work in such a way that a subscriber with a pending request
+ * remains in memory.
+ */
+struct subscr_request {
+ struct llist_head entry;
+
+ /* back reference */
+ struct gsm_subscriber *subscr;
+
+ /* the requested channel type */
+ int channel_type;
+
+ /* the bts we have decided to use */
+ struct gsm_network *network;
+
+ /* the callback data */
+ gsm_cbfn *cbfn;
+ void *param;
+};
+
+/*
+ * We got the channel assigned and can now hand this channel
+ * over to one of our callbacks.
+ */
+static int subscr_paging_cb(unsigned int hooknum, unsigned int event,
+ struct msgb *msg, void *data, void *param)
+{
+ struct subscr_request *request;
+ struct gsm_subscriber *subscr = (struct gsm_subscriber *)param;
+
+ assert(!llist_empty(&subscr->requests));
+
+ /*
+ * FIXME: What to do with paging requests coming during
+ * this callback? We must be sure to not start paging when
+ * we have an active connection to a subscriber and to make
+ * the subscr_put_channel work as required...
+ */
+ request = (struct subscr_request *)subscr->requests.next;
+ llist_del(&request->entry);
+ subscr->in_callback = 1;
+ request->cbfn(hooknum, event, msg, data, request->param);
+ subscr->in_callback = 0;
+
+ free(request);
+ return 0;
+}
+
+static void subscr_send_paging_request(struct gsm_subscriber *subscr)
+{
+ struct subscr_request *request;
+ assert(!llist_empty(&subscr->requests));
+
+ request = (struct subscr_request *)subscr->requests.next;
+ paging_request(request->network, subscr, request->channel_type,
+ subscr_paging_cb, subscr);
+}
+
struct gsm_subscriber *subscr_alloc(void)
{
struct gsm_subscriber *s;
@@ -138,7 +200,36 @@
struct gsm_network *network, int type,
gsm_cbfn *cbfn, void *param)
{
- paging_request(network, subscr, type, cbfn, param);
+ struct subscr_request *request;
+
+ request = (struct subscr_request *)malloc(sizeof(*request));
+ if (!request) {
+ if (cbfn)
+ cbfn(GSM_HOOK_RR_PAGING, GSM_PAGING_OOM,
+ NULL, NULL, param);
+ return;
+ }
+
+ memset(request, 0, sizeof(*request));
+ request->network = network;
+ request->subscr = subscr;
+ request->channel_type = type;
+ request->cbfn = cbfn;
+ request->param = param;
+
+ /*
+ * FIXME: We might be able to assign more than one
+ * channel, e.g. voice and SMS submit at the same
+ * time.
+ */
+ if (!subscr->in_callback && llist_empty(&subscr->requests)) {
+ /* add to the list, send a request */
+ llist_add_tail(&request->entry, &subscr->requests);
+ subscr_send_paging_request(subscr);
+ } else {
+ /* this will be picked up later, from subscr_put_channel */
+ llist_add_tail(&request->entry, &subscr->requests);
+ }
}
void subscr_put_channel(struct gsm_lchan *lchan)
@@ -149,6 +240,21 @@
* of the lchan after having asked the next requestee to handle
* the channel.
*/
+ /*
+ * FIXME: is the lchan is of a different type we could still
+ * issue an immediate assignment for another channel and then
+ * close this one.
+ */
+ /*
+ * Currently we will drop the last ref of the lchan which
+ * will result in a channel release on RSL and we will start
+ * the paging. This should work most of the time as the MS
+ * will listen to the paging requests before we timeout
+ */
+
put_lchan(lchan);
+
+ if (lchan->subscr && !llist_empty(&lchan->subscr->requests))
+ subscr_send_paging_request(lchan->subscr);
}