Evgeniy,
Sorry ! ; last sentence in my reply was chopped so here is my message
again with this last sentence (complete this time)
Thnks, I appreciate your (quick) answer;
Following your answer I tried adding a call to net_enable_timestamp() in
a module I wrote which use NF_HOOKS.
This is what is done , for example, in ipq_rcv_skb(struct sk_buff *skb)
in linux-2.6.14 in net/ipv4/netfilter/ip_queue.c.
After doing so I get timestamps which are not 0.
what I wonder now is :
1) does this have ANY performance implication (when dealing with a
high network load which can get to 50,000 packets per second?
2) It does work as I said, but I want to be cautios: Am I permitted to
add this method ? are there any implications for adding this method
which can create troubles ?
I must say that I am NOT changing anywhere the timestamp; it's only
for statistics.
Regards,
John
On 8/17/06, Evgeniy Polyakov <[EMAIL PROTECTED]> wrote:
On Thu, Aug 17, 2006 at 05:37:15PM +0300, John Que ([EMAIL PROTECTED]) wrote:
> Hello,
> I am using NF_HOOKS (a "PRE_ROUTING" hook).
> When I try to print the time stamps (sec and usec) of skb packets
> which I recieve
> in the hook callback I get 0. Other skb fileds are correct.
> According to my understanding, the time stamp should be updated
> when the packet is received. Isn't it so ? Any idea why am I getting
> "0" for tstamp fields (tstamp is a field in sk_buff and is an intance
> of skb_timeval).
Timestamps are disabled by default, if you have sockets which enable
SO_TIMESTAMP or netfilter queue target and other agents which can enable
it, you will see updated values in skb->tstamp.
--
Evgeniy Polyakov
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