[PATCH 3/3] [channel] Handle and dispatch paging requests in gsm_subscriber

From d1e5ef15114ee6071597d4338500c553d9959c87 Mon Sep 17 00:00:00 2001 From: Holger Freyther &lt;ich(a)tamarin.(none)&gt; Date: Sat, 18 Apr 2009 13:48:55 +0200 Subject: [PATCH 3/3] [channel] Handle and dispatch paging requests in gsm_subscriber Implement subscr_get_channel to a degree that a pending SMS Submit and a phone call should work. --- include/openbsc/gsm_data.h | 1 + include/openbsc/gsm_subscriber.h | 1 + src/gsm_subscriber.c | 113 ++++++++++++++++++++++++++++++++++++- 3 files changed, 111 insertions(+), 4 deletions(-) diff --git a/include/openbsc/gsm_data.h b/include/openbsc/gsm_data.h index 297d505..9a13b4b 100644 --- a/include/openbsc/gsm_data.h +++ b/include/openbsc/gsm_data.h @@ -26,6 +26,7 @@ enum gsm_paging_event { GSM_PAGING_SUCCEEDED, GSM_PAGING_EXPIRED, GSM_PAGING_VLR_UNKNOWN, + GSM_PAGING_OOM, }; struct msgb; diff --git a/include/openbsc/gsm_subscriber.h b/include/openbsc/gsm_subscriber.h index abe1fd7..d5c2a90 100644 --- a/include/openbsc/gsm_subscriber.h +++ b/include/openbsc/gsm_subscriber.h @@ -25,6 +25,7 @@ struct gsm_subscriber { struct llist_head entry; /* pending requests */ + int in_callback; struct llist_head requests; }; diff --git a/src/gsm_subscriber.c b/src/gsm_subscriber.c index d9e7116..200ac8f 100644 --- a/src/gsm_subscriber.c +++ b/src/gsm_subscriber.c @@ -25,16 +25,78 @@ #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 gsm_network *gsmnet = NULL; +/* + * 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_bts *bts; + + /* the callback data */ + gsm_cbfn *cbfn; + void *data; +}; + +/* + * 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 *)data; + + 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, request->data, 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->bts, subscr, request->channel_type, + subscr_paging_cb, subscr); +} + struct gsm_subscriber *subscr_alloc(void) { struct gsm_subscriber *s; @@ -139,8 +201,10 @@ void subscr_get_channel(struct gsm_subscriber *subscr, struct gsm_bts *default_bts, int type, gsm_cbfn *cbfn, void *data) { - /* FIXME: Find the right BTS... */ + struct subscr_request *request; struct gsm_bts *bts; + + /* FIXME: Find the right BTS... */ if (default_bts) bts = default_bts; else @@ -149,8 +213,34 @@ void subscr_get_channel(struct gsm_subscriber *subscr, if (!bts) goto error; - paging_request(bts, subscr, type, cbfn, data); - return; + request = (struct subscr_request *)malloc(sizeof(*request)); + if (!request) { + if (cbfn) + cbfn(GSM_HOOK_RR_PAGING, GSM_PAGING_OOM, + NULL, NULL, data); + return; + } + + memset(request, 0, sizeof(*request)); + request->bts = bts; + request->subscr = subscr; + request->channel_type = type; + request->cbfn = cbfn; + request->data = data; + + /* + * 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 */ + llist_add_tail(&request->entry, &subscr->requests); + } error: if (!cbfn) @@ -166,7 +256,22 @@ void subscr_put_channel(struct gsm_lchan *lchan) * 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); } void subscr_init(struct gsm_network *net) -- 1.6.3.1