Re: Capture send packets in ZC mode

Yes : 

https://github.com/google/gopacket/blob/master/pfring/pfring.go#L247

On Thu, 2017-10-26 at 19:14 +0200, Alfredo Cardigliano wrote:
> Hi
> are you setting the flush flag to 1 when calling pfring_send()?
> 
> Alfredo
> 
> > 
> > On 26 Oct 2017, at 18:42, Charles-Antoine Mathieu <charles-antoine.
> > [email protected]> wrote:
> > 
> > Hi,
> > 
> > I'm trying to implement that, but my results looks odd. I'm trying
> > to
> > ping a bunch of ~20 hosts with a latency of ~1.77 ms every 5
> > seconds.
> > 
> > I capture time right after pfring_send and pfring_recv. For every
> > batch
> > I get around the same latency for every host but the latency range
> > from
> > 1ms to 300ms.
> > 
> > 37.187.9.32 : 11.532119ms
> > 37.187.9.245 : 11.54512ms
> > 37.187.9.124 : 11.525933ms
> > ... 5 sec later the next batch ...
> > 37.187.9.14 : 107.540483ms
> > 37.187.9.17 : 107.519064ms
> > 37.187.9.32 : 107.505375ms
> > 
> > I wonder if you are aware of some kind of buffering that might
> > happen
> > in the process to yield such results.
> > 
> > The ring is opened in ZC mode
> > NIC model is Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network
> > Connection (rev 01)
> > 
> > I'm using gopacket and ARISTA's nanotime package to capture a
> > monotonic
> > time which rely upon CLOCK_MONOTONIC, it seems more reliable and
> > lightweight that time.Now() to me.
> > https://github.com/aristanetworks/goarista/blob/master/monotime/nan
> > otim
> > e.go
> > 
> > On Fri, 2017-10-06 at 16:38 +0200, Alfredo Cardigliano wrote:
> > > 
> > > Hi
> > > in ZC mode kernel is bypassed, thus you should send the packet
> > > and
> > > call clock_gettime()
> > > immediately after in order to compute latency (the same function
> > > is
> > > used for RX in this case).
> > > 
> > > Alfredo
> > > 
> > > > 
> > > > 
> > > > On 6 Oct 2017, at 16:34, Charles-Antoine Mathieu <charles-
> > > > antoine.m
> > > > [email protected]> wrote:
> > > > 
> > > > Hello,
> > > > 
> > > > I have a process that sends and receive ICMP packets using
> > > > PF_RING.
> > > > 
> > > > I'd like to capture send and received packets to be able to
> > > > compute
> > > > the
> > > > latency. When I'm not in ZC mode I get the send and the
> > > > received
> > > > packet
> > > > in the capture. However in ZC mode I only get the received
> > > > packets
> > > > in
> > > > the capture.
> > > > 
> > > > Is there a way go get the same behaviour in ZC mode ?
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