diff options
Diffstat (limited to 'src/libmsc/ussd.c')
| -rw-r--r-- | src/libmsc/ussd.c | 69 |
1 files changed, 61 insertions, 8 deletions
diff --git a/src/libmsc/ussd.c b/src/libmsc/ussd.c index f285fcf8a..a27d47bd6 100644 --- a/src/libmsc/ussd.c +++ b/src/libmsc/ussd.c @@ -35,6 +35,10 @@ #include <osmocom/msc/osmo_msc.h> #include <osmocom/msc/vlr.h> #include <osmocom/msc/gsm_04_08.h> +#include <osmocom/msc/transaction.h> + +/* FIXME: choose a proper range */ +static uint32_t new_callref = 0x20000001; /* Declarations of USSD strings to be recognised */ const char USSD_TEXT_OWN_NUMBER[] = "*#100#"; @@ -57,19 +61,60 @@ static int send_own_number(struct gsm_subscriber_connection *conn, /* Entrypoint - handler function common to all mobile-originated USSDs */ int handle_rcv_ussd(struct gsm_subscriber_connection *conn, struct msgb *msg) { - int rc; + struct gsm48_hdr *gh = msgb_l3(msg); + struct gsm_trans *trans; struct ss_request req; - struct gsm48_hdr *gh; + uint8_t pdisc, tid; + uint8_t msg_type; + int rc; - /* TODO: Use subscriber_connection ref-counting if we ever want - * to keep the connection alive due ot ongoing USSD exchange. - * As we answer everytying synchronously so far, there's no need - * yet */ + pdisc = gsm48_hdr_pdisc(gh); + msg_type = gsm48_hdr_msg_type(gh); + tid = gsm48_hdr_trans_id_flip_ti(gh); - cm_service_request_concludes(conn, msg); + /* Associate logging messages with this subscriber */ + log_set_context(LOG_CTX_VLR_SUBSCR, conn->vsub); + + DEBUGP(DMM, "Received SS/USSD data (trans_id=%x, msg_type=%s)\n", + tid, gsm48_pdisc_msgtype_name(pdisc, msg_type)); + + /* Reuse existing transaction, or create a new one */ + trans = trans_find_by_id(conn, pdisc, tid); + if (!trans) { + /** + * According to GSM TS 04.80, section 2.4.2 "Register + * (mobile station to network direction)", the REGISTER + * message is sent by the mobile station to the network + * to assign a new transaction identifier for call independent + * supplementary service control and to request or acknowledge + * a supplementary service. + */ + if (msg_type != GSM0480_MTYPE_REGISTER) { + LOGP(DMM, LOGL_ERROR, "Unexpected message (msg_type=%s), " + "transaction is not allocated yet\n", + gsm48_pdisc_msgtype_name(pdisc, msg_type)); + gsm0480_send_ussd_reject(conn, &req, + GSM_0480_PROBLEM_CODE_TAG_GENERAL, + GSM_0480_GEN_PROB_CODE_UNRECOGNISED); + return -EINVAL; + } + + DEBUGP(DMM, " -> (new transaction)\n"); + trans = trans_alloc(conn->network, conn->vsub, + pdisc, tid, new_callref++); + if (!trans) { + DEBUGP(DMM, " -> No memory for trans\n"); + gsm0480_send_ussd_return_error(conn, &req, + GSM0480_ERR_CODE_SYSTEM_FAILURE); + return -ENOMEM; + } + + trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_NC_SS); + trans->dlci = OMSC_LINKID_CB(msg); + cm_service_request_concludes(conn, msg); + } memset(&req, 0, sizeof(req)); - gh = msgb_l3(msg); rc = gsm0480_decode_ss_request(gh, msgb_l3len(msg), &req); if (!rc) { LOGP(DMM, LOGL_ERROR, "SS/USSD message parsing error, " @@ -101,5 +146,13 @@ int handle_rcv_ussd(struct gsm_subscriber_connection *conn, struct msgb *msg) GSM0480_ERR_CODE_UNEXPECTED_DATA_VALUE); } + /** + * TODO: as we only handle *#100# for now, and always + * respond with RELEASE COMPLETE, let's manually free + * the transaction here, until the external interface + * is implemented. + */ + trans_free(trans); + return rc; } |