Re: [dpdk-users] Replicating PCAP packets read by pktgen for multiple source addresses

[Ravi Tandon <ravi.tandon1982@gmail.com>]

Dear Keith,

I was able to make it work after some code review by calling
rte_pktmbuf_free_bulk, after rte_eth_tx_burst.

Regards,
Ravi



On Mon, Sep 14, 2020 at 7:52 PM Ravi Tandon <ravi.tandon1982@gmail.com>
wrote:

> Dear Keith,
>
> After updating the refcnt value, I am able to transmit packet with
> multiple source IPs but the transmission stops after some time, even if I
> give
> start command again, transmission never starts, please let me know if I
> missed something, basically I want transmission forever unless stop command
> is triggered.
>
> The updated code is as below, I added 3 lines having num_src_ip in them to
> see whether my packets are transmitted burst x num_src_ip times, but
> transmission stopped after sometime, and I am unable to start it
> unless I restart pktgen
>
> static __inline__ void
> pktgen_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;
> *uint32_t num_src_ip = 5; /*Hard coded for timebeing*/*
>
> if ((cnt = mtab->len) == 0)
> return;
>
> mtab->len = 0;
> pkts = mtab->m_table;
>
> if (pktgen_tst_port_flags(info, SEND_RANGE_PKTS))
> seq_idx = RANGE_PKT;
> else if (pktgen_tst_port_flags(info, SEND_RATE_PACKETS))
> seq_idx = RATE_PKT;
> else
> seq_idx = SINGLE_PKT;
>
> tap = pktgen_tst_port_flags(info, PROCESS_TX_TAP_PKTS);
> rnd = pktgen_tst_port_flags(info, SEND_RANDOM_PKTS);
> tstamp = pktgen_tst_port_flags(info, (SEND_LATENCY_PKTS |
> SEND_RATE_PACKETS));
>
> qstats = &info->qstats[qid];
> qstats->txpkts += cnt;
> for (i = 0; i < cnt; i++) {
> qstats->txbytes += rte_pktmbuf_data_len(pkts[i]);
> *rte_mbuf_refcnt_update(pkts[i], num_src_ip);*
> }
>
> /* Send all of the packets before we can exit this function */
> while (cnt) {
> if (rnd)
> pktgen_rnd_bits_apply(info, pkts, cnt, NULL);
>
> if (tstamp)
> pktgen_tstamp_apply(info, pkts, cnt, seq_idx);
>
>
> *for(i = 0; i < num_src_ip; i++) *ret = rte_eth_tx_burst(info->pid, qid,
> pkts, cnt);
>
> if (tap)
> pktgen_do_tx_tap(info, pkts, ret);
>
> pkts += (ret);
> cnt -= (ret);
> }
> }
>
>
> Regards,
> Ravi
>
> On Mon, Sep 14, 2020 at 6:03 PM Ravi Tandon <ravi.tandon1982@gmail.com>
> wrote:
>
>> Thanks Keith.
>>
>> I updated the refcnt and it worked.
>>
>> Regards,
>> Ravi
>>
>> On Mon, Sep 14, 2020 at 3:30 PM Wiles, Keith <keith.wiles@intel.com>
>> wrote:
>>
>>> 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
>>>
>>> Hi,
>>>
>>> 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)
>>> return;
>>>
>>> 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;
>>> else
>>> 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 |
>>> SEND_RATE_PACKETS));
>>>
>>> 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
>>> rte_eth_tx_burst*/*
>>> /* 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.
>>>
>>> Thanks
>>> Ravi
>>>
>>