> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Ferruh Yigit > Sent: Wednesday, 27 October 2021 12.49 > > On 10/20/2021 11:12 AM, Xiaoyun Li wrote: > > In csum forwarding mode, software UDP/TCP csum calculation only takes > > the first segment into account while using the whole packet length so > > the calculation will read invalid memory region with multi-segments > > packets and will get wrong value. > > This patch fixes this issue. > > > > Fixes: af75078fece3 ("first public release") > > Cc: sta...@dpdk.org > > > > Signed-off-by: Xiaoyun Li <xiaoyun...@intel.com> > > --- > > v3: > > * Use rte_raw_cksum() for multi-segs case instead of copying the > whole > > * packet. > > v2: > > * Use static stack memory instead of dynamic allocating in datapath > > --- > > app/test-pmd/csumonly.c | 68 ++++++++++++++++++++++++++++++++------ > --- > > 1 file changed, 53 insertions(+), 15 deletions(-) > > > > diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c > > index 090797318a..f3e60eb3c3 100644 > > --- a/app/test-pmd/csumonly.c > > +++ b/app/test-pmd/csumonly.c > > @@ -91,12 +91,41 @@ struct simple_gre_hdr { > > } __rte_packed; > > > > static uint16_t > > -get_udptcp_checksum(void *l3_hdr, void *l4_hdr, uint16_t ethertype) > > +get_udptcp_checksum(void *l3_hdr, struct rte_mbuf *m, uint16_t > l4_off, > > + uint16_t ethertype) > > { > > + uint16_t off = l4_off; > > + uint32_t cksum = 0; > > + char *buf; > > + > > + while (m != NULL) { > > + buf = rte_pktmbuf_mtod_offset(m, char *, off); > > + cksum += rte_raw_cksum(buf, m->data_len - off); > > + off = 0; > > + m = m->next; > > + } > > if (ethertype == _htons(RTE_ETHER_TYPE_IPV4)) > > - return rte_ipv4_udptcp_cksum(l3_hdr, l4_hdr); > > + cksum += rte_ipv4_phdr_cksum(l3_hdr, 0); > > else /* assume ethertype == RTE_ETHER_TYPE_IPV6 */ > > - return rte_ipv6_udptcp_cksum(l3_hdr, l4_hdr); > > + cksum += rte_ipv6_phdr_cksum(l3_hdr, 0); > > + > > Hi Xiaoyun, > > I can see 'rte_ipv[46]_udptcp_cksum()' is not taking multi segment mbuf > into account, so this fix is required, > but instead of implementing this logic into testpmd, what do you think > to have APIs to support multi segment mbufs? > This way other applications also benefit from it and we don't need to > maintain ip4/6 checksum related code in testpmd.
+1 Also, there is no need to implement the multi-segment raw checksum loop in test-pmd. You can use the multi-segment raw checksum function in the net library instead: http://code.dpdk.org/dpdk/latest/source/lib/net/rte_ip.h#L224 > > btw, how are you testing this?
