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From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Zhike Wang <wangzk320@163.com>, dev@dpdk.org
Cc: wangzhike@jd.com, Cian Ferriter <cian.ferriter@intel.com>
Subject: Re: [dpdk-dev] [PATCH] net/pcap: truncate packet if it is too large
Date: Tue, 3 Dec 2019 10:15:22 +0000
Message-ID: <b722195b-7ed7-e660-4762-6a9db1eaa903@intel.com> (raw)
In-Reply-To: <1573180417-5528-1-git-send-email-wangzk320@163.com>

On 11/8/2019 2:33 AM, Zhike Wang wrote:
> From: Zhike Wang <wangzhike@jd.com>
> 
> Previously large packet would be dropped, instead now it is better to keep it via truncating it.

Looks reasonable, thanks.

cc'ing Cian too, since he did some pcap work recently.

> 
> Signed-off-by: Zhike Wang <wangzhike@jd.com>
> ---
>  drivers/net/pcap/rte_eth_pcap.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
> index 5186d8f..4614239 100644
> --- a/drivers/net/pcap/rte_eth_pcap.c
> +++ b/drivers/net/pcap/rte_eth_pcap.c
> @@ -313,7 +313,7 @@ struct pmd_devargs_all {
>  	struct pcap_pkthdr header;
>  	pcap_dumper_t *dumper;
>  	unsigned char temp_data[RTE_ETH_PCAP_SNAPLEN];
> -	size_t len;
> +	size_t len, caplen;
>  
>  	pp = rte_eth_devices[dumper_q->port_id].process_private;
>  	dumper = pp->tx_dumper[dumper_q->queue_id];
> @@ -328,25 +328,23 @@ struct pmd_devargs_all {
>  		len = rte_pktmbuf_pkt_len(mbuf);
>  		if (unlikely(!rte_pktmbuf_is_contiguous(mbuf) &&
>  				len > sizeof(temp_data))) {
> -			PMD_LOG(ERR,
> -				"Dropping multi segment PCAP packet. Size (%zd) > max size (%zd).",
> -				len, sizeof(temp_data));
> -			rte_pktmbuf_free(mbuf);
> -			continue;
> +			caplen = sizeof(temp_data);
> +		} else {
> +			caplen = len;

No strong opinion, but what do you think removing the else leg by assigning the
'caplen' by default to 'len':
 len = caplen = rte_pktmbuf_pkt_len(mbuf);

>  		}
>  
>  		calculate_timestamp(&header.ts);
>  		header.len = len;
> -		header.caplen = header.len;
> +		header.caplen = caplen;
>  		/* rte_pktmbuf_read() returns a pointer to the data directly
>  		 * in the mbuf (when the mbuf is contiguous) or, otherwise,
>  		 * a pointer to temp_data after copying into it.
>  		 */
>  		pcap_dump((u_char *)dumper, &header,
> -			rte_pktmbuf_read(mbuf, 0, len, temp_data));
> +			rte_pktmbuf_read(mbuf, 0, caplen, temp_data));
>  
>  		num_tx++;
> -		tx_bytes += len;
> +		tx_bytes += caplen;
>  		rte_pktmbuf_free(mbuf);
>  	}
>  
> 


      reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-08  2:33 Zhike Wang
2019-12-03 10:15 ` Ferruh Yigit [this message]

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