RSL: Actually check if BSC-requested cipher is supported

include/osmo-bts/gsm_data.h

@@ -45,6 +45,9 @@ struct gsm_bts_role_bts {
 	char *bsc_oml_host;
 	char *rtp_bind_host;
 	unsigned int rtp_jitter_buf_ms;
+	struct {
+		uint8_t ciphers;
+	} support;
 };
 
 #define bts_role_bts(x)	((struct gsm_bts_role_bts *)(x)->role)

src/common/rsl.c

@@ -568,6 +568,12 @@ static void copy_sacch_si_to_lchan(struct gsm_lchan *lchan)
 static int encr_info2lchan(struct gsm_lchan *lchan,
 			   const uint8_t *val, uint8_t len)
 {
+	struct gsm_bts_role_bts *btsb = bts_role_bts(lchan->ts->trx->bts);
+
+	/* check if the encryption algorithm sent by BSC is supported! */
+	if (!((1 << *val) & btsb->support.ciphers))
+		 return -ENOTSUP;
+
 	/* length can be '1' in case of no ciphering */
 	if (len < 1)
 		return -EINVAL;
@@ -805,8 +811,6 @@ static int rsl_rx_encr_cmd(struct msgb *msg)
 			 return rsl_tx_error_report(msg->trx, RSL_ERR_IE_CONTENT);
 	}
 
-	/* FIXME: check if the encryption algorithm sent by BSC is supported! */
-
 	/* 9.3.2 Link Identifier */
 	link_id = *TLVP_VAL(&tp, RSL_IE_LINK_IDENT);
 

src/osmo-bts-sysmo/main.c

@@ -210,6 +210,7 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 	btsb = bts_role_bts(bts);
+	btsb->support.ciphers = (1 << 0) | (1 << 1) | (1 << 2);
 
 	handle_options(argc, argv);