Hi Banashankar, For proper TCP checksum calculation you have to calculate checksum over pseudo header (see app/test-pmd/cmdline.c) and put result in tcp_hdr->cksum
2014-01-26 Wiles, Roger Keith <keith.wiles at windriver.com> > Hi Banashankar, > > The tx_conf is used in the pktgen_config_ports() with the > rte_eth_tx_queue_setup() and I am not sure why it matters that tx_conf is > disable. The values are mostly zero, but some type of interaction must be > going on. It may be the txq_flags being set to IXGBE_SIMPLE_FLAGS and it > is overriding the the per packet flag later. You will need to look at the > driver to determine the real reason. > > The checksum should not be wrong unless the hardware registers are not > setup correctly, but I would not think that is the case. You may want to > verify the checksum is correct another way, because I can not see the > hardware doing the checksum wrong. > > Thanks > ++Keith > > > Keith Wiles, Principal Technologist for Networking member of the CTO > office, Wind River > mobile 940.213.5533 > [Powering 30 Years of Innovation]<http://www.windriver.com/announces/wr30/ > > > > On Jan 25, 2014, at 4:53 PM, Banashankar KV <banveerad at gmail.com<mailto: > banveerad at gmail.com>> wrote: > > Hi, > Thanks a lot for the reply ! > Yes I have checked those examples and had set all those flags. But IP > checksum started working after commenting off the txq_flags from > the pktgen.c file's tx_conf . > > And I added the following flag to calculate the tcp checksum. > > m->ol_flags |= PKT_TX_TCP_CKSUM > > its calculating the TCP checksum but turning out to be wrong checksum. > > Thanks > Banashankar > > > > On Fri, Jan 24, 2014 at 11:44 AM, Wiles, Roger Keith < > keith.wiles at windriver.com<mailto:keith.wiles at windriver.com>> wrote: > I have not enabled that feature myself, but I would expect it to work as > long as the hardware does. What does the docs say about enabling hardware > offload support? Did you look at the following files: > > ip_reassembly/ipv4_rsmbl.h: m->ol_flags |= PKT_TX_IP_CKSUM; > ipv4_frag/rte_ipv4_frag.h: out_pkt->ol_flags |= > PKT_TX_IP_CKSUM; > > Thanks > ++Keith > > Keith Wiles, Principal Technologist for Networking member of the CTO > office, Wind River > mobile 940.213.5533<tel:940.213.5533> > [Powering 30 Years of Innovation]<http://www.windriver.com/announces/wr30/ > > > > On Jan 24, 2014, at 12:54 PM, Banashankar KV <banveerad at gmail.com<mailto: > banveerad at gmail.com>> wrote: > > I was modifying a packet in pktgen_pcap_mbuf_ctor() > and after modifying I wanted to offload the checksum calculation to h/w > so I am setting these flags in pktgen_pcap_mbuf_ctor function. > > m->pkt.vlan_macip.f.l2_len = sizeof(struct ether_hdr); > m->pkt.vlan_macip.f.l3_len = sizeof(struct ipv4_hdr); > > m->ol_flags = PKT_TX_IP_CKSUM > > > I even tried with setting .txq_flags = 0 in rte_eth_txconf struct in > pktgen.c. > > But still not able to get the h/w checksum. Am I missing anything ? > > > > Thanks > Banashankar > > > > Regards, Vladimir
