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netfilter: nft_meta: use 64-bit time arithmetic

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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: 63d10e12b0 ("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>
This commit is contained in:
Arnd Bergmann 2019-11-08 22:32:47 +01:00 committed by Pablo Neira Ayuso
parent fcbad8293d
commit 6408c40c39
1 changed files with 5 additions and 5 deletions
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10
net/netfilter/nft_meta.c
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@ -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);