On 3/22/2022 1:02 PM, Ido Goshen wrote:
This test
https://doc.dpdk.org/dts/test_plans/jumboframes_test_plan.html#test-case-jumbo-frames-with-no-jumbo-frame-support
fails for pcap pmd
Jumbo packet is unexpectedly received and transmitted
Hi Ido,
Yes, pcap ignores MTU, but I don't see why it should use MTU (except
from making above DTS test pass).
For the cases packets written to .pcap file or read from a .pcap file,
most probably user is interested in all packets, I don't think using MTU
to filter the packets is a good idea, missing packets (because of MTU)
can confuse users.
Unless there is a good use case, I am for rejecting this feature.
----------------------------------------------------------------------------------------
without patch:
root@u18c_3nbp:/home/cgs/workspace/master/jumbo# ./dpdk-testpmd --no-huge
-m1024 -l 0-2
--vdev='net_pcap0,rx_pcap=rx_pcap=jumbo_9000.pcap,tx_pcap=file_tx.pcap' --
--no-flush-rx --total-num-mbufs=2048 -i
...
testpmd> start
...
testpmd> show port stats 0
######################## NIC statistics for port 0 ########################
RX-packets: 1 RX-missed: 0 RX-bytes: 8996
RX-errors: 0
RX-nombuf: 0
TX-packets: 1 TX-errors: 0 TX-bytes: 8996
Throughput (since last show)
Rx-pps: 0 Rx-bps: 0
Tx-pps: 0 Tx-bps: 0
############################################################################
----------------------------------------------------------------------------------------
While with the patch it will fail unless --max-pkt-len is used to support jumbo
root@u18c_3nbp:/home/cgs/workspace/master/jumbo# ./dpdk-testpmd-patch --no-huge
-m1024 -l 0-2
--vdev='net_pcap0,rx_pcap=rx_pcap=jumbo_9000.pcap,tx_pcap=file_tx.pcap' --
--no-flush-rx --total-num-mbufs=2048 -i
...
testpmd> start
...
testpmd> show port stats 0
######################## NIC statistics for port 0 ########################
RX-packets: 0 RX-missed: 0 RX-bytes: 0
RX-errors: 1
RX-nombuf: 0
TX-packets: 0 TX-errors: 0 TX-bytes: 0
Throughput (since last show)
Rx-pps: 0 Rx-bps: 0
Tx-pps: 0 Tx-bps: 0
############################################################################
root@u18c_3nbp:/home/cgs/workspace/master/jumbo# ./dpdk-testpmd-patch --no-huge
-m1024 -l 0-2
--vdev='net_pcap0,rx_pcap=rx_pcap=jumbo_9000.pcap,tx_pcap=file_tx.pcap' --
--no-flush-rx --total-num-mbufs=2048 -i --max-pkt-len 9400
...
testpmd> start
...
testpmd> show port stats 0
######################## NIC statistics for port 0 ########################
RX-packets: 1 RX-missed: 0 RX-bytes: 8996
RX-errors: 0
RX-nombuf: 0
TX-packets: 1 TX-errors: 0 TX-bytes: 8996
Throughput (since last show)
Rx-pps: 0 Rx-bps: 0
Tx-pps: 0 Tx-bps: 0
############################################################################
-----Original Message-----
From: Ido Goshen
Sent: Thursday, 17 March 2022 21:12
To: Stephen Hemminger <step...@networkplumber.org>
Cc: Ferruh Yigit <ferruh.yi...@intel.com>; dev@dpdk.org
Subject: RE: [PATCH] net/pcap: support MTU set
As far as I can see the initial device MTU is derived from port *RX*
configuration
in struct rte_eth_rxmode https://doc.dpdk.org/api-
21.11/structrte__eth__rxmode.html
Couple of real NICs I've tested (ixgbe, i40e based) don't allow oversized, tests
details can be seen in https://bugs.dpdk.org/show_bug.cgi?id=961
-----Original Message-----
From: Stephen Hemminger <step...@networkplumber.org>
Sent: Thursday, 17 March 2022 20:21
To: Ido Goshen <i...@cgstowernetworks.com>
Cc: Ferruh Yigit <ferruh.yi...@intel.com>; dev@dpdk.org
Subject: Re: [PATCH] net/pcap: support MTU set
On Thu, 17 Mar 2022 19:43:47 +0200
ido g <i...@cgstowernetworks.com> wrote:
+ if (unlikely(header.caplen > dev->data->mtu)) {
+ pcap_q->rx_stat.err_pkts++;
+ rte_pktmbuf_free(mbuf);
+ break;
+ }
MTU should only be enforced on transmit.
Other real network devices allow oversized packets.
Since the pcap file is something user provides, if you don't want that
then use something to filter the file.
