netfilter: nft_meta: use 64-bit time arithmetic (6408c40c) · Commits · 戴 / test

On 32-bit architectures, get_seconds() returns an unsigned 32-bit time value, which also matches the type used in the nft_meta code. This will not overflow in year 2038 as a time_t would, but it still suffers from the overflow problem later on in year 2106. Change this instance to use the time64_t type consistently and avoid the deprecated get_seconds(). The nft_meta_weekday() calculation potentially gets a little slower on 32-bit architectures, but now it has the same behavior as on 64-bit architectures and does not overflow. Fixes: ("netfilter: nft_meta: support for time matching") Signed-off-by:

Arnd Bergmann <arnd@arndb.de> Acked-by:

Phil Sutter <phil@nwl.cc> Signed-off-by:

Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_meta.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -33,19 +33,19 @@

		static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);

		static u8 nft_meta_weekday(unsigned long secs)
		static u8 nft_meta_weekday(time64_t secs)
		{
		unsigned int dse;
		u8 wday;

		secs -= NFT_META_SECS_PER_MINUTE * sys_tz.tz_minuteswest;
		dse = secs / NFT_META_SECS_PER_DAY;
		dse = div_u64(secs, NFT_META_SECS_PER_DAY);
		wday = (4 + dse) % NFT_META_DAYS_PER_WEEK;

		return wday;
		}

		static u32 nft_meta_hour(unsigned long secs)
		static u32 nft_meta_hour(time64_t secs)
		{
		struct tm tm;

		@@ -250,10 +250,10 @@ void nft_meta_get_eval(const struct nft_expr *expr,
		nft_reg_store64(dest, ktime_get_real_ns());
		break;
		case NFT_META_TIME_DAY:
		nft_reg_store8(dest, nft_meta_weekday(get_seconds()));
		nft_reg_store8(dest, nft_meta_weekday(ktime_get_real_seconds()));
		break;
		case NFT_META_TIME_HOUR:
		*dest = nft_meta_hour(get_seconds());
		*dest = nft_meta_hour(ktime_get_real_seconds());
		break;
		default:
		WARN_ON(1);

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