libmsc: duplicate gsm0808 / gsm48 functions (towards BSC)

In osmo-nitb, libmsc would directly call the functions on the BSC level, not
always via the bsc_api. When separating libmsc from libbsc, some functions are
missing from the linkage.

Hence duplicate these functions to libmsc, add an msc_ prefix for clarity, also
add a _tx to gsm0808_cipher_mode():

* add msc_gsm0808_tx_cipher_mode() (dummy/stub)
* add msc_gsm48_tx_mm_serv_ack()
* add msc_gsm48_tx_mm_serv_rej()

Call these from libmsc instead of

* gsm0808_cipher_mode()
* gsm48_tx_mm_serv_ack()
* gsm48_tx_mm_serv_rej()

Also add a comment relatd to msc_gsm0808_tx_cipher_mode() in two places.

Change-Id: I5b276853d3af71f5e3f0a031fd17b4fff0580020

1 files changed, 12 insertions, 0 deletions

diff --git a/openbsc/src/libmsc/a_iface.c b/openbsc/src/libmsc/a_iface.c
index 0eaeef188..1f471f97b 100644
--- a/openbsc/src/libmsc/a_iface.c
+++ b/openbsc/src/libmsc/a_iface.c
@@ -22,6 +22,9 @@
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/logging.h>
 
+#include <openbsc/debug.h>
+
+#include <openbsc/gsm_data.h>
 #include <openbsc/msc_ifaces.h>
 #include <openbsc/debug.h>
 
@@ -31,3 +34,12 @@ int a_tx(struct msgb *msg)
 	     " not implemented.\n%s\n", osmo_hexdump(msg->data, msg->len));
 	return -1;
 }
+
+int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
+			       const uint8_t *key, int len, int include_imeisv)
+{
+	/* TODO generalize for A- and Iu interfaces, don't name after 08.08 */
+	LOGP(DMSC, LOGL_ERROR, "gsm0808_cipher_mode(): message to be sent to"
+	     " BSC, but A interface not yet implemented.\n");
+	return -1;
+}