linux-kernel - [PATCH] netfilter: xt_time: use is_leap

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Message-ID: <20260123081051.336239-1-ruanjinjie@huawei.com>
Date: Fri, 23 Jan 2026 16:10:51 +0800
From: Jinjie Ruan <ruanjinjie@...wei.com>
To: <pablo@...filter.org>, <fw@...len.de>, <phil@....cc>,
	<davem@...emloft.net>, <edumazet@...gle.com>, <kuba@...nel.org>,
	<pabeni@...hat.com>, <horms@...nel.org>, <netfilter-devel@...r.kernel.org>,
	<coreteam@...filter.org>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: <ruanjinjie@...wei.com>
Subject: [PATCH] netfilter: xt_time: use is_leap_year() helper

Use the is_leap_year() helper from rtc.h instead of
writing it by hand

Signed-off-by: Jinjie Ruan <ruanjinjie@...wei.com>
---
 net/netfilter/xt_time.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/xt_time.c b/net/netfilter/xt_time.c
index 6aa12d0f54e2..00319d2a54da 100644
--- a/net/netfilter/xt_time.c
+++ b/net/netfilter/xt_time.c
@@ -14,6 +14,7 @@
 
 #include <linux/ktime.h>
 #include <linux/module.h>
+#include <linux/rtc.h>
 #include <linux/skbuff.h>
 #include <linux/types.h>
 #include <linux/netfilter/x_tables.h>
@@ -64,11 +65,6 @@ static const u_int16_t days_since_epoch[] = {
 	3287, 2922, 2557, 2191, 1826, 1461, 1096, 730, 365, 0,
 };
 
-static inline bool is_leap(unsigned int y)
-{
-	return y % 4 == 0 && (y % 100 != 0 || y % 400 == 0);
-}
-
 /*
  * Each network packet has a (nano)seconds-since-the-epoch (SSTE) timestamp.
  * Since we match against days and daytime, the SSTE value needs to be
@@ -138,7 +134,7 @@ static void localtime_3(struct xtm *r, time64_t time)
 	 * (A different approach to use would be to subtract a monthlength
 	 * from w repeatedly while counting.)
 	 */
-	if (is_leap(year)) {
+	if (is_leap_year(year)) {
 		/* use days_since_leapyear[] in a leap year */
 		for (i = ARRAY_SIZE(days_since_leapyear) - 1;
 		    i > 0 && days_since_leapyear[i] > w; --i)
-- 
2.34.1