From 3229f442f46480551479b987f2f6a1b5c360e4d6 Mon Sep 17 00:00:00 2001 From: Holger Hans Peter Freyther Date: Mon, 11 Oct 2010 10:07:37 +0200 Subject: nat: Implement the matching of certain USSD messages Have various checks, check if the IMSI should be handled, if there is a USSD query set and then decode and compare the value. --- openbsc/src/nat/bsc_ussd.c | 64 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 63 insertions(+), 1 deletion(-) diff --git a/openbsc/src/nat/bsc_ussd.c b/openbsc/src/nat/bsc_ussd.c index 1812cf71d..c4e30d842 100644 --- a/openbsc/src/nat/bsc_ussd.c +++ b/openbsc/src/nat/bsc_ussd.c @@ -24,9 +24,71 @@ #include #include +#include + +#include + +#include + int bsc_check_ussd(struct sccp_connections *con, struct bsc_nat_parsed *parsed, struct msgb *msg) { - return 0; + uint32_t len; + uint8_t msg_type; + struct gsm48_hdr *hdr48; + struct bsc_nat_acc_lst *lst; + struct ussd_request req; + + /* + * various checks to avoid the decoding work. Right now we only want to + * decode if the connection was created for USSD, we do have a USSD access + * list, a query, a IMSI and such... + */ + if (con->con_type != NAT_CON_TYPE_SSA) + return 0; + + if (!con->imsi) + return 0; + + if (!con->bsc->nat->ussd_lst_name) + return 0; + if (!con->bsc->nat->ussd_query) + return 0; + + if (parsed->bssap != BSSAP_MSG_DTAP) + return 0; + + if (strlen(con->imsi) > GSM_IMSI_LENGTH) + return 0; + + hdr48 = bsc_unpack_dtap(parsed, msg, &len); + if (!hdr48) + return 0; + + msg_type = hdr48->msg_type & 0xbf; + if (hdr48->proto_discr != GSM48_PDISC_NC_SS || msg_type != GSM0480_MTYPE_REGISTER) + return 0; + + /* now check if it is a IMSI we care about */ + lst = bsc_nat_acc_lst_find(con->bsc->nat, con->bsc->nat->ussd_lst_name); + if (!lst) + return 0; + + if (bsc_nat_lst_check_allow(lst, con->imsi) != 0) + return 0; + + /* now decode the message and see if we really want to handle it */ + memset(&req, 0, sizeof(req)); + if (gsm0480_decode_ussd_request(hdr48, len, &req) != 1) + return 0; + if (req.text[0] == 0xff) + return 0; + + if (strcmp(req.text, con->bsc->nat->ussd_query) != 0) + return 0; + + /* found a USSD query for our subscriber */ + LOGP(DNAT, LOGL_NOTICE, "Found USSD query for %s\n", con->imsi); + return 1; } -- cgit v1.2.3