nat: And out the skip_indicator/transaction id from the gsm48 header
We need to and out the protocol discriminator as call control
might have use transactions. This has only failed for the USSD
filter so far as this must deal with transactions.
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 8c164a2..d382565 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -542,15 +542,16 @@
parsed->gsm_type == BSS_MAP_MSG_CIPHER_MODE_CMD) {
con->authorized = 1;
} else if (parsed->bssap == BSSAP_MSG_DTAP) {
- uint8_t msg_type;
+ uint8_t msg_type, proto;
uint32_t len;
struct gsm48_hdr *hdr48;
hdr48 = bsc_unpack_dtap(parsed, msg, &len);
if (!hdr48)
return;
+ proto = hdr48->proto_discr & 0x0f;
msg_type = hdr48->msg_type & 0xbf;
- if (hdr48->proto_discr == GSM48_PDISC_MM &&
+ if (proto == GSM48_PDISC_MM &&
msg_type == GSM48_MT_MM_CM_SERV_ACC)
con->authorized = 1;
}