> From: Olivier Matz [mailto:olivier.m...@6wind.com] > Sent: Friday, July 10, 2020 2:41 PM > > On Fri, Jul 10, 2020 at 02:55:51PM +0800, Hongzhi Guo wrote: > > Per RFC768: > > If the computed checksum is zero, it is transmitted as all ones. > > An all zero transmitted checksum value means that the transmitter > > generated no checksum. > > > > RFC793 for TCP has no such special treatment for the checksum of > zero. > > > > Fixes: 6006818cfb26 ("net: new checksum functions") > > Cc: sta...@dpdk.org > > > > Signed-off-by: Hongzhi Guo <guohongz...@huawei.com> > > --- > > v2: > > * Fixed commit tile > > * Fixed the API comment > > --- > > --- > > lib/librte_net/rte_ip.h | 18 +++++++++++++++--- > > 1 file changed, 15 insertions(+), 3 deletions(-) > > > > diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h > > index 292f63fd7..d03c77120 100644 > > --- a/lib/librte_net/rte_ip.h > > +++ b/lib/librte_net/rte_ip.h > > @@ -325,7 +325,7 @@ rte_ipv4_phdr_cksum(const struct rte_ipv4_hdr > *ipv4_hdr, uint64_t ol_flags) > > * The pointer to the beginning of the L4 header. > > * @return > > * The complemented checksum to set in the IP packet > > - * or 0 on error > > + * or 0 if the IP length is invalid in the header. > > */ > > static inline uint16_t > > rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const > void *l4_hdr)
0 is a valid return value, so I suggest omitting it from the return value description: * @return - * The complemented checksum to set in the IP packet - * or 0 on error + * The complemented checksum to set in the IP packet. The comparison "if (l3_len < sizeof(struct rte_ipv4_hdr))" is only there to protect against invalid input; it prevents l4_len from becoming negative. For the same reason, unlikely() should be added to this comparison. Otherwise, Acked-by: Morten Brørup <m...@smartsharesystems.com>
