Re: [dpdk-dev] Client Server Application using DPDK API

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Mar 15, 2016 at 09:06:12AM +0000, Vivek Gupta wrote:
> Hi
> 
> I am developing a network program using DPDK API. I want to extract the data which is there is rte_mbuf structure.
> 
> Referred to rte_mbuf structure manual but confused with fields 
> 
> uint16_t buf_len;         /**< Length of segment buffer. */
> uint16_t data_len;        /**< Amount of data in segment buffer. */
> 
> 
> Can someone help me to understand how to extract data from buffer?

The first value is the size of the buffer, the second is the amount of data
in the buffer. When working with a packet in an mbuf, the data_len is the value
you want.

/Bruce

> 
> Thanks & regards
> Vivek Gupta
> 
> -----Original Message-----
> From: Remy Horton [mailto:remy.horton@intel.com] 
> Sent: Wednesday, March 09, 2016 10:14 PM
> To: Vivek Gupta
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] Client Server Application using DPDK API
> 
> 'noon,
> 
> On 09/03/2016 08:45, Vivek Gupta wrote:
> > Hi
> >
> > I want to write a Client Server application using DPDK API on a single 
> > machine. What are the basic building block for that. How can we write 
> > such application?
> 
> examples/l2fwd/main.c and examples/ethtool/ethtool-app/main.c are probably the easier examples to follow. In terms of function calls, it is pretty much:
> 
> rte_eal_init(..);
> for (each port) {
> 	rte_pktmbuf_pool_create(..);
> 	rte_eth_dev_configure(..);
> 	rte_eth_dev_rx_queue_setup(..);
> 	rte_eth_dev_tx_queue_setup(..);
> 	rte_eth_dev_start(..);
> }
> while(1) {
> 	rte_eth_rx_burst(..); /* incoming frames */
> 	rte_eth_tx_burst(..); /* outgoing frames */ }
> 
> Bear in mind that DPDK deals with MAC frames rather than higher level IP packets, which may be an issue if you intend to use TCP/IP based application protocols.
> 
> 
> > ::DISCLAIMER::
> 
> Avoid using confidentality disclaimers on mailing list emails. It tends to "annoy" people.. :)
> 
> Regards,
> 
> ..Remy
> 
> 
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