gsm/a5: Return -ENOTSUP if the selected cipher is not supported
Extracted from a patch by Max Suraev Max.Suraev@fairwaves.ru>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/gsm/a5.h b/include/osmocom/gsm/a5.h
index 649dbab..2f78a92 100644
--- a/include/osmocom/gsm/a5.h
+++ b/include/osmocom/gsm/a5.h
@@ -54,7 +54,7 @@
* - fn is the _real_ GSM frame number.
* (converted internally to fn_count)
*/
-void osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul);
+int osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul);
void osmo_a5_1(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul);
void osmo_a5_2(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul);
diff --git a/src/gsm/a5.c b/src/gsm/a5.c
index 356060a..de821e8 100644
--- a/src/gsm/a5.c
+++ b/src/gsm/a5.c
@@ -34,6 +34,7 @@
* \brief Osmocom GSM A5 ciphering algorithm implementation
*/
+#include <errno.h>
#include <string.h>
#include <osmocom/gsm/a5.h>
@@ -44,11 +45,12 @@
* \param[in] fn Frame number
* \param[out] dl Pointer to array of ubits to return Downlink cipher stream
* \param[out] ul Pointer to array of ubits to return Uplink cipher stream
+ * \returns 0 for success, -ENOTSUP for invalid cipher selection.
*
* Currently A5/[0-2] are supported.
* Either (or both) of dl/ul can be NULL if not needed.
*/
-void
+int
osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul)
{
switch (n)
@@ -70,8 +72,10 @@
default:
/* a5/[3..7] not supported here/yet */
- break;
+ return -ENOTSUP;
}
+
+ return 0;
}