[NET]: Fix packet timestamping.
I've found the problem in general. It affects any 64-bit
architecture. The problem occurs when you change the system time.
Suppose that when you boot your system clock is forward by a day.
This gets recorded down in skb_tv_base. You then wind the clock back
by a day. From that point onwards the offset will be negative which
essentially overflows the 32-bit variables they're stored in.
In fact, why don't we just store the real time stamp in those 32-bit
variables? After all, we're not going to overflow for quite a while
yet.
When we do overflow, we'll need a better solution of course.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index f81fe8c..eaa44c4 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -492,8 +492,8 @@
if (entry->skb->tstamp.off_sec) {
struct nfqnl_msg_packet_timestamp ts;
- ts.sec = cpu_to_be64(skb_tv_base.tv_sec + entry->skb->tstamp.off_sec);
- ts.usec = cpu_to_be64(skb_tv_base.tv_usec + entry->skb->tstamp.off_usec);
+ ts.sec = cpu_to_be64(entry->skb->tstamp.off_sec);
+ ts.usec = cpu_to_be64(entry->skb->tstamp.off_usec);
NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
}