libmsc/gsm_04_11.c: refactor MT SMS message handling
According to GSM TS 04.11, the SMC (Short Message Control) state
machine is a part of CM-sublayer of L3, that is responsible for
connection management (establisment and releasing), and SM-RP
(Relay Protocol) message delivery.
For some reason, the connection establisment request from SMC
(GSM411_MMSMS_EST_REQ) was not handled properly - it was
always assumed that connection is already established.
This is why the code initiating a MT (Mobile Terminated) SMS
transfer had to establish a radio connection with subscriber
manually.
Let's benefit from having the SMC state machine, and offload
connection establishment to it. This change makes the local
implementation closer to GSM TS 04.11, and facilitates the
further integration of GSUP transport.
NOTE: the expected unit test output is changed, because now we
always allocate a transaction first, and then establish a
connection, not vice versa.
Change-Id: I4a07ece80d8dd40b23da6bb1ffc9d3d745b54092
diff --git a/src/libmsc/gsm_04_11.c b/src/libmsc/gsm_04_11.c
index 14f9f57..88dc433 100644
--- a/src/libmsc/gsm_04_11.c
+++ b/src/libmsc/gsm_04_11.c
@@ -127,6 +127,87 @@
return msc_tx_dtap(conn, msg);
}
+/* Paging callback for MT SMS (Paging is triggered by SMC) */
+static int paging_cb_mmsms_est_req(unsigned int hooknum, unsigned int event,
+ struct msgb *msg, void *_conn, void *_trans)
+{
+ struct gsm_subscriber_connection *conn = _conn;
+ struct gsm_trans *trans = _trans;
+ struct gsm_sms *sms = trans->sms.sms;
+ int rc = 0;
+
+ DEBUGP(DLSMS, "paging_cb_mmsms_est_req(hooknum=%u, event=%u, "
+ "conn=%p, trans=%p)\n", hooknum, event, conn, trans);
+
+ if (hooknum != GSM_HOOK_RR_PAGING)
+ return -EINVAL;
+
+ /* Paging procedure has finished */
+ trans->paging_request = NULL;
+
+ switch (event) {
+ case GSM_PAGING_SUCCEEDED:
+ /* Associate transaction with established connection */
+ trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
+ /* FIXME: specify SACCH in case we already have active TCH */
+ trans->dlci = 0x03;
+ /* Confirm successful connection establishment */
+ gsm411_smc_recv(&trans->sms.smc_inst,
+ GSM411_MMSMS_EST_CNF, NULL, 0);
+ break;
+ case GSM_PAGING_EXPIRED:
+ case GSM_PAGING_BUSY:
+ /* Inform SMC about channel establishment failure */
+ gsm411_smc_recv(&trans->sms.smc_inst,
+ GSM411_MMSMS_REL_IND, NULL, 0);
+
+ /* Notify the SMSqueue and free stored SMS */
+ send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, event);
+ trans->sms.sms = NULL;
+ sms_free(sms);
+
+ /* Destroy this transaction */
+ trans_free(trans);
+ rc = -ETIMEDOUT;
+ break;
+ default:
+ LOGP(DLSMS, LOGL_ERROR, "Unhandled paging event: %d\n", event);
+ }
+
+ return rc;
+}
+
+static int gsm411_mmsms_est_req(struct gsm_trans *trans)
+{
+ /* Subscriber's data shall be associated */
+ OSMO_ASSERT(trans->vsub != NULL);
+
+ /* Check if connection is already established */
+ if (trans->conn != NULL) {
+ LOGP(DLSMS, LOGL_DEBUG, "Using an existing connection "
+ "for %s\n", vlr_subscr_name(trans->vsub));
+ return gsm411_smc_recv(&trans->sms.smc_inst,
+ GSM411_MMSMS_EST_CNF, NULL, 0);
+ }
+
+ /* Initiate Paging procedure */
+ LOGP(DLSMS, LOGL_DEBUG, "Initiating Paging procedure "
+ "for %s due to MMSMS_EST_REQ\n", vlr_subscr_name(trans->vsub));
+ trans->paging_request = subscr_request_conn(trans->vsub,
+ paging_cb_mmsms_est_req, trans, "MT SMS");
+ if (!trans->paging_request) {
+ LOGP(DLSMS, LOGL_ERROR, "Failed to initiate Paging "
+ "procedure for %s\n", vlr_subscr_name(trans->vsub));
+ /* Inform SMC about channel establishment failure */
+ gsm411_smc_recv(&trans->sms.smc_inst,
+ GSM411_MMSMS_REL_IND, NULL, 0);
+ trans_free(trans);
+ return -EIO;
+ }
+
+ return 0;
+}
+
/* Prefix msg with a 04.08/04.11 CP header */
static int gsm411_cp_sendmsg(struct msgb *msg, struct gsm_trans *trans,
uint8_t msg_type)
@@ -154,8 +235,7 @@
switch (msg_type) {
case GSM411_MMSMS_EST_REQ:
- /* recycle msg */
- rc = gsm411_smc_recv(inst, GSM411_MMSMS_EST_CNF, msg, 0);
+ rc = gsm411_mmsms_est_req(trans);
msgb_free(msg); /* upper layer does not free msg */
break;
case GSM411_MMSMS_DATA_REQ:
@@ -899,6 +979,120 @@
return rc;
}
+static struct gsm_trans *gsm411_alloc_mt_trans(struct gsm_network *net,
+ struct vlr_subscr *vsub)
+{
+ struct gsm_subscriber_connection *conn;
+ struct gsm_trans *trans;
+ int tid;
+
+ LOGP(DLSMS, LOGL_INFO, "Going to send a MT SMS\n");
+
+ /* Generate a new transaction ID */
+ tid = trans_assign_trans_id(net, vsub, GSM48_PDISC_SMS, 0);
+ if (tid == -1) {
+ LOGP(DLSMS, LOGL_ERROR, "No available transaction IDs\n");
+ return NULL;
+ }
+
+ /* Allocate a new transaction */
+ trans = trans_alloc(net, vsub, GSM48_PDISC_SMS, tid, new_callref++);
+ if (!trans) {
+ LOGP(DLSMS, LOGL_ERROR, "No memory for trans\n");
+ return NULL;
+ }
+
+ /* Init both SMC and SMR state machines */
+ gsm411_smc_init(&trans->sms.smc_inst, 0, 1,
+ gsm411_mn_recv, gsm411_mm_send);
+ gsm411_smr_init(&trans->sms.smr_inst, 0, 1,
+ gsm411_rl_recv, gsm411_mn_send);
+
+ /* Attempt to find an existing connection */
+ conn = connection_for_subscr(vsub);
+ if (conn) {
+ /* Associate transaction with connection */
+ trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
+ /* Generate unique RP Message Reference */
+ trans->sms.sm_rp_mr = conn->next_rp_ref++;
+ }
+
+ return trans;
+}
+
+/* High-level function to send an SMS to a given subscriber */
+int gsm411_send_sms(struct gsm_network *net,
+ struct vlr_subscr *vsub,
+ struct gsm_sms *sms)
+{
+ uint8_t *data, *rp_ud_len;
+ struct gsm_trans *trans;
+ struct msgb *msg;
+ int rc;
+
+ /* Allocate a new transaction for MT SMS */
+ trans = gsm411_alloc_mt_trans(net, vsub);
+ if (!trans) {
+ send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, 0);
+ sms_free(sms);
+ return -ENOMEM;
+ }
+
+ /* Allocate a message buffer for to be encoded SMS */
+ msg = gsm411_msgb_alloc();
+ if (!msg) {
+ send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, 0);
+ trans_free(trans);
+ sms_free(sms);
+ return -ENOMEM;
+ }
+
+ /* Hardcode SMSC Originating Address for now */
+ data = (uint8_t *)msgb_put(msg, 8);
+ data[0] = 0x07; /* originator length == 7 */
+ data[1] = 0x91; /* type of number: international, ISDN */
+ data[2] = 0x44; /* 447785016005 */
+ data[3] = 0x77;
+ data[4] = 0x58;
+ data[5] = 0x10;
+ data[6] = 0x06;
+ data[7] = 0x50;
+
+ /* Hardcoded Destination Address */
+ data = (uint8_t *)msgb_put(msg, 1);
+ data[0] = 0; /* destination length == 0 */
+
+ /* obtain a pointer for the rp_ud_len, so we can fill it later */
+ rp_ud_len = (uint8_t *)msgb_put(msg, 1);
+
+ if (sms->is_report) {
+ /* generate the 03.40 SMS-STATUS-REPORT TPDU */
+ rc = gsm340_gen_sms_status_report_tpdu(msg, sms);
+ } else {
+ /* generate the 03.40 SMS-DELIVER TPDU */
+ rc = gsm340_gen_sms_deliver_tpdu(msg, sms);
+ }
+ if (rc < 0) {
+ send_signal(S_SMS_UNKNOWN_ERROR, trans, sms, 0);
+ sms_free(sms);
+ trans_free(trans);
+ msgb_free(msg);
+ return rc;
+ }
+
+ *rp_ud_len = rc;
+
+ /* Store a pointer to abstract SMS representation */
+ trans->sms.sms = sms;
+
+ rate_ctr_inc(&net->msc_ctrs->ctr[MSC_CTR_SMS_DELIVERED]);
+ db_sms_inc_deliver_attempts(trans->sms.sms);
+
+ return gsm411_rp_sendmsg(&trans->sms.smr_inst, msg,
+ GSM411_MT_RP_DATA_MT, trans->sms.sm_rp_mr,
+ GSM411_SM_RL_DATA_REQ);
+}
+
/* Entry point for incoming GSM48_PDISC_SMS from abis_rsl.c */
int gsm0411_rcv_sms(struct gsm_subscriber_connection *conn,
struct msgb *msg)
@@ -985,159 +1179,6 @@
return rc;
}
-/* Take a SMS in gsm_sms structure and send it through an already
- * existing conn. We also assume that the caller ensured this conn already
- * has a SAPI3 RLL connection! */
-int gsm411_send_sms(struct gsm_subscriber_connection *conn, struct gsm_sms *sms)
-{
- struct msgb *msg = gsm411_msgb_alloc();
- struct gsm_trans *trans;
- uint8_t *data, *rp_ud_len;
- uint8_t msg_ref = conn->next_rp_ref++;
- int transaction_id;
- int rc;
-
- transaction_id =
- trans_assign_trans_id(conn->network, conn->vsub,
- GSM48_PDISC_SMS, 0);
- if (transaction_id == -1) {
- LOGP(DLSMS, LOGL_ERROR, "No available transaction ids\n");
- send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, 0);
- sms_free(sms);
- msgb_free(msg);
- return -EBUSY;
- }
-
- DEBUGP(DLSMS, "%s()\n", __func__);
-
- /* FIXME: allocate transaction with message reference */
- trans = trans_alloc(conn->network, conn->vsub,
- GSM48_PDISC_SMS,
- transaction_id, new_callref++);
- if (!trans) {
- LOGP(DLSMS, LOGL_ERROR, "No memory for trans\n");
- send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, 0);
- sms_free(sms);
- msgb_free(msg);
- /* FIXME: send some error message */
- return -ENOMEM;
- }
- gsm411_smc_init(&trans->sms.smc_inst, sms->id, 1,
- gsm411_mn_recv, gsm411_mm_send);
- gsm411_smr_init(&trans->sms.smr_inst, sms->id, 1,
- gsm411_rl_recv, gsm411_mn_send);
- trans->sms.sms = sms;
-
- trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
- trans->dlci = 0x03;
- /* FIXME: specify SACCH in case we already have active TCH */
-
- /* Hardcode SMSC Originating Address for now */
- data = (uint8_t *)msgb_put(msg, 8);
- data[0] = 0x07; /* originator length == 7 */
- data[1] = 0x91; /* type of number: international, ISDN */
- data[2] = 0x44; /* 447785016005 */
- data[3] = 0x77;
- data[4] = 0x58;
- data[5] = 0x10;
- data[6] = 0x06;
- data[7] = 0x50;
-
- /* Hardcoded Destination Address */
- data = (uint8_t *)msgb_put(msg, 1);
- data[0] = 0; /* destination length == 0 */
-
- /* obtain a pointer for the rp_ud_len, so we can fill it later */
- rp_ud_len = (uint8_t *)msgb_put(msg, 1);
-
- if (sms->is_report) {
- /* generate the 03.40 SMS-STATUS-REPORT TPDU */
- rc = gsm340_gen_sms_status_report_tpdu(msg, sms);
- } else {
- /* generate the 03.40 SMS-DELIVER TPDU */
- rc = gsm340_gen_sms_deliver_tpdu(msg, sms);
- }
- if (rc < 0) {
- send_signal(S_SMS_UNKNOWN_ERROR, trans, sms, 0);
- sms_free(sms);
- trans->sms.sms = NULL;
- trans_free(trans);
- msgb_free(msg);
- return rc;
- }
-
- *rp_ud_len = rc;
-
- DEBUGP(DLSMS, "TX: SMS DELIVER\n");
-
- rate_ctr_inc(&conn->network->msc_ctrs->ctr[MSC_CTR_SMS_DELIVERED]);
- db_sms_inc_deliver_attempts(trans->sms.sms);
-
- return gsm411_rp_sendmsg(&trans->sms.smr_inst, msg,
- GSM411_MT_RP_DATA_MT, msg_ref, GSM411_SM_RL_DATA_REQ);
-}
-
-/* paging callback. Here we get called if paging a subscriber has
- * succeeded or failed. */
-static int paging_cb_send_sms(unsigned int hooknum, unsigned int event,
- struct msgb *msg, void *_conn, void *_sms)
-{
- struct gsm_subscriber_connection *conn = _conn;
- struct gsm_sms *sms = _sms;
- int rc = 0;
-
- DEBUGP(DLSMS, "paging_cb_send_sms(hooknum=%u, event=%u, msg=%p,"
- "conn=%p, sms=%p/id: %llu)\n", hooknum, event, msg, conn, sms, sms->id);
-
- if (hooknum != GSM_HOOK_RR_PAGING)
- return -EINVAL;
-
- switch (event) {
- case GSM_PAGING_SUCCEEDED:
- gsm411_send_sms(conn, sms);
- break;
- case GSM_PAGING_EXPIRED:
- case GSM_PAGING_BUSY:
- send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, event);
- sms_free(sms);
- rc = -ETIMEDOUT;
- break;
- default:
- LOGP(DLSMS, LOGL_ERROR, "Unhandled paging event: %d\n", event);
- }
-
- return rc;
-}
-
-/* high-level function to send a SMS to a given subscriber. The function
- * will take care of paging the subscriber, establishing the RLL SAPI3
- * connection, etc. */
-int gsm411_send_sms_subscr(struct vlr_subscr *vsub,
- struct gsm_sms *sms)
-{
- struct gsm_subscriber_connection *conn;
- void *res;
-
- /* check if we already have an open conn to the subscriber.
- * if yes, send the SMS this way */
- conn = connection_for_subscr(vsub);
- if (conn) {
- LOGP(DLSMS, LOGL_DEBUG, "Sending SMS via already open connection %p to %s\n",
- conn, vlr_subscr_name(vsub));
- return gsm411_send_sms(conn, sms);
- }
-
- /* if not, we have to start paging */
- LOGP(DLSMS, LOGL_DEBUG, "Sending SMS: no connection open, start paging %s\n",
- vlr_subscr_name(vsub));
- res = subscr_request_conn(vsub, paging_cb_send_sms, sms, "send SMS");
- if (!res) {
- send_signal(S_SMS_UNKNOWN_ERROR, NULL, sms, GSM_PAGING_BUSY);
- sms_free(sms);
- }
- return 0;
-}
-
void _gsm411_sms_trans_free(struct gsm_trans *trans)
{
/* cleanup SMS instance */