04.08: add inline funcs for transaction id bits
Various users of gsm48_hdr apply the same hardcoded shifts/bitmasks to obtain
the transaction ID encoded in the upper nibble of the protocol discriminator.
Centralize. Patch for openbsc.git will follow.
diff --git a/include/osmocom/gsm/protocol/gsm_04_08.h b/include/osmocom/gsm/protocol/gsm_04_08.h
index 49e977b..d49b77f 100644
--- a/include/osmocom/gsm/protocol/gsm_04_08.h
+++ b/include/osmocom/gsm/protocol/gsm_04_08.h
@@ -763,6 +763,25 @@
return pdisc;
}
+static inline uint8_t gsm48_hdr_trans_id(const struct gsm48_hdr *hdr)
+{
+ /*
+ * 3GPP TS 24.007 version 12.0.0 Release 12,
+ * 11.2.3.1.3 Transaction identifier
+ */
+ return (hdr->proto_discr & 0xf0) >> 4;
+}
+
+static inline uint8_t gsm48_hdr_trans_id_flip_ti(const struct gsm48_hdr *hdr)
+{
+ return gsm48_hdr_trans_id(hdr) ^ 0x08;
+}
+
+static inline uint8_t gsm48_hdr_trans_id_no_ti(const struct gsm48_hdr *hdr)
+{
+ return gsm48_hdr_trans_id(hdr) & 0x07;
+}
+
static inline uint8_t gsm48_hdr_msg_type_r98(const struct gsm48_hdr *hdr)
{
/*