[NETFILTER]: xt_time: fix failure to match on Sundays
From: Andrew Schulman <andrex@xxxxxxxxxxxxxxxxx>
xt_time_match() in net/netfilter/xt_time.c in kernel 2.6.24 never
matches on Sundays. On my host I have a rule like
iptables -A OUTPUT -m time --weekdays Sun -j REJECT
and it never matches. The problem is in localtime_2(), which uses
r->weekday = (4 + r->dse) % 7;
to map the epoch day onto a weekday in {0,...,6}. In particular this
gives 0 for Sundays. But 0 has to be wrong; a weekday of 0 can never
match. xt_time_match() has
if (!(info->weekdays_match & (1 << current_time.weekday)))
return false;
and when current_time.weekday = 0, the result of the & is always
zero, even when info->weekdays_match = XT_TIME_ALL_WEEKDAYS = 0xFE.
Signed-off-by: Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx>
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
---
commit 342661f5a04f90772e0d33302634e010ab3649ed
tree 3dc6d36f9d245b9f2990ab503735904c1d8187d1
parent b306ccc2129dfc062653b3436df714fc758f3c45
author Andrew Schulman <andrex@xxxxxxxxxxxxxxxxx> Mon, 10 Mar 2008 17:50:42 +0100
committer Patrick McHardy <kaber@xxxxxxxxx> Mon, 10 Mar 2008 17:50:42 +0100
net/netfilter/xt_time.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/xt_time.c b/net/netfilter/xt_time.c
index e9a8794..9fa2e08 100644
--- a/net/netfilter/xt_time.c
+++ b/net/netfilter/xt_time.c
@@ -95,8 +95,11 @@ static inline void localtime_2(struct xtm *r, time_t time)
*/
r->dse = time / 86400;
- /* 1970-01-01 (w=0) was a Thursday (4). */
- r->weekday = (4 + r->dse) % 7;
+ /*
+ * 1970-01-01 (w=0) was a Thursday (4).
+ * -1 and +1 map Sunday properly onto 7.
+ */
+ r->weekday = (4 + r->dse - 1) % 7 + 1;
}
static void localtime_3(struct xtm *r, time_t time)
--
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