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From: "Wiles, Keith" <keith.wiles@intel.com>
To: Ravi Tandon <ravi.tandon1982@gmail.com>,
	"users@dpdk.org" <users@dpdk.org>
Subject: Re: [dpdk-users] Replicating PCAP packets read by pktgen for multiple	source addresses
Date: Mon, 14 Sep 2020 13:30:46 +0000
Message-ID: <DM6PR11MB45931F68589DB041E32F6CA2FE230@DM6PR11MB4593.namprd11.prod.outlook.com> (raw)
In-Reply-To: <CAKDHAW9GPKDdiwc5kpSVK=5nuGX3x3MRESt_xEUQvxpXY9UnvQ@mail.gmail.com>

You can edit the packet in the function below, but you have to do that action everytime. Freeing the mbuf I sok, you can look into the refcnt value in the mbuf if you want tx_burst to not free the packet completely.

From: users <users-bounces@dpdk.org>
Date: Sunday, September 13, 2020 at 5:00 PM
To: users@dpdk.org <users@dpdk.org>
Subject: [dpdk-users] Replicating PCAP packets read by pktgen for multiple source addresses

I want to use pktgen to read a pcap file and play that pcap file say 10
times by editing the source IP address for each run, please let me know
what's the best way of doing this.

I first thought of editing the source IP in the rte_mbuf pointed by pkts
before calling the rte_eth_tx_burst(info->pid, qid, pkts, cnt) function but
it seems that rte_eth_tx_burst function frees up the rte_mbuf pointed by
pkts after sending the packet once so I cannot edit the pkts buffer again.

static __inline__ void
trafficgen_send_burst(port_info_t *info, uint16_t qid)
struct mbuf_table   *mtab = &info->q[qid].tx_mbufs;
struct rte_mbuf **pkts;
struct qstats_s *qstats;
uint32_t ret, cnt, tap, rnd, tstamp, i;
int32_t seq_idx;

if ((cnt = mtab->len) == 0)

mtab->len = 0;
pkts = mtab->m_table;

if (trafficgen_tst_port_flags(info, SEND_RANGE_PKTS))
seq_idx = RANGE_PKT;
else if (trafficgen_tst_port_flags(info, SEND_RATE_PACKETS))
seq_idx = RATE_PKT;
seq_idx = SINGLE_PKT;

tap = trafficgen_tst_port_flags(info, PROCESS_TX_TAP_PKTS);
rnd = trafficgen_tst_port_flags(info, SEND_RANDOM_PKTS);
tstamp = trafficgen_tst_port_flags(info, (SEND_LATENCY_PKTS |

qstats = &info->qstats[qid];
qstats->txpkts += cnt;
for (i = 0; i < cnt; i++)
qstats->txbytes += rte_pktmbuf_data_len(pkts[i]);

*/*Inserting a for loop here doesn't help as rte_mbuf is freed by
/* Send all of the packets before we can exit this function */
while (cnt) {

if (rnd)
trafficgen_rnd_bits_apply(info, pkts, cnt, NULL);

if (tstamp)
trafficgen_tstamp_apply(info, pkts, cnt, seq_idx);

ret = rte_eth_tx_burst(info->pid, qid, pkts, cnt);

if (tap)
trafficgen_do_tx_tap(info, pkts, ret);

pkts += ret;
cnt -= ret;

Basically, I want to resend buffers stored in rte_mbuf again and again,
after modifying source IP in each run.


  reply	other threads:[~2020-09-14 13:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-13 21:59 Ravi Tandon
2020-09-14 13:30 ` Wiles, Keith [this message]
2020-09-14 16:03   ` Ravi Tandon
2020-09-14 17:52     ` Ravi Tandon
2020-09-14 21:19       ` Ravi Tandon

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