llc: Make timeval arguments const

Some struct timeval pointer arguments do not have the const qualifier,
albeit the methods do not write to the structures. The next commit
will change related pointers to const, so this commit provides the
required constness.

Sponsored-by: On-Waves ehf

src/gprs_bssgp_pcu.cpp

@@ -804,8 +804,8 @@ struct bssgp_bvc_ctx *gprs_bssgp_pcu_current_bctx(void)
 	return the_pcu.bctx;
 }
 
-void gprs_bssgp_update_queue_delay(struct timeval *tv_recv,
-	struct timeval *tv_now)
+void gprs_bssgp_update_queue_delay(const struct timeval *tv_recv,
+	const struct timeval *tv_now)
 {
 	struct timeval *delay_sum = &the_pcu.queue_delay_sum;
 	struct timeval tv_delay;

src/gprs_bssgp_pcu.h

@@ -83,7 +83,7 @@ void gprs_bssgp_destroy(void);
 
 struct bssgp_bvc_ctx *gprs_bssgp_pcu_current_bctx(void);
 
-void gprs_bssgp_update_queue_delay(struct timeval *tv_recv,
-		struct timeval *tv_now);
+void gprs_bssgp_update_queue_delay(const struct timeval *tv_recv,
+		const struct timeval *tv_now);
 
 #endif // GPRS_BSSGP_PCU_H

src/llc.cpp

@@ -175,7 +175,8 @@ void gprs_llc_queue::calc_pdu_lifetime(BTS *bts, const uint16_t pdu_delay_csec,
 	timeradd(&now, &csec, tv);
 }
 
-bool gprs_llc_queue::is_frame_expired(struct timeval *tv_now, struct timeval *tv)
+bool gprs_llc_queue::is_frame_expired(const struct timeval *tv_now,
+	const struct timeval *tv)
 {
 	/* Timeout is infinite */
 	if (tv->tv_sec == 0 && tv->tv_usec == 0)

src/llc.h

@@ -63,8 +63,10 @@ struct gprs_llc {
  * I store the LLC frames that come from the SGSN.
  */
 struct gprs_llc_queue {
-	static void calc_pdu_lifetime(BTS *bts, const uint16_t pdu_delay_csec, struct timeval *tv);
-	static bool is_frame_expired(struct timeval *now, struct timeval *tv);
+	static void calc_pdu_lifetime(BTS *bts, const uint16_t pdu_delay_csec,
+		struct timeval *tv);
+	static bool is_frame_expired(const struct timeval *now,
+		const struct timeval *tv);
 	static bool is_user_data_frame(uint8_t *data, size_t len);
 
 	void init();