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[NET]: Fix packet timestamping.

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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>
This commit is contained in:
Herbert Xu
2005-10-03 13:57:23 -07:00
committed by David S. Miller
parent ddea7be0ec
commit 325ed82393
8 changed files with 15 additions and 26 deletions
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4
net/ipv6/netfilter/ip6_queue.c
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@@ -238,8 +238,8 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
pmsg->packet_id = (unsigned long )entry;
pmsg->data_len = data_len;
pmsg->timestamp_sec = skb_tv_base.tv_sec + entry->skb->tstamp.off_sec;
pmsg->timestamp_usec = skb_tv_base.tv_usec + entry->skb->tstamp.off_usec;
pmsg->timestamp_sec = entry->skb->tstamp.off_sec;
pmsg->timestamp_usec = entry->skb->tstamp.off_usec;
pmsg->mark = entry->skb->nfmark;
pmsg->hook = entry->info->hook;
pmsg->hw_protocol = entry->skb->protocol;