On Fri, Jul 10, 2020 at 02:20:08PM +0200, Morten Brørup wrote: > > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Hongzhi Guo > > Sent: Friday, July 10, 2020 1:43 PM > > > > With current code, the checksum of odd-length buffers is wrong on > > big endian CPUs: the last byte is not properly summed to the > > accumulator. > > > > Fix this by left-shifting the remaining byte by 8. For instance, > > if the last byte is 0x42, we should add 0x4200 to the accumulator > > on big endian CPUs. > > > > This change is similar to what is suggested in Errata 3133 of > > RFC 1071. > > > > Fixes: 6006818cfb26("net: new checksum functions") > > Cc: sta...@dpdk.org > > > > Signed-off-by: Hongzhi Guo <guohongz...@huawei.com> > > --- > > v2: > > * Explain the logic in the commit log > > * Fixed commit title > > --- > > --- > > lib/librte_net/rte_ip.h | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h > > index 292f63fd7..4fb0e314a 100644 > > --- a/lib/librte_net/rte_ip.h > > +++ b/lib/librte_net/rte_ip.h > > @@ -139,8 +139,11 @@ __rte_raw_cksum(const void *buf, size_t len, > > uint32_t sum) > > } > > > > /* if length is in odd bytes */ > > - if (len == 1) > > - sum += *((const uint8_t *)u16_buf); > > + if (len == 1) { > > + uint16_t left = 0; > > + *(uint8_t *)&left = *(const uint8_t *)u16_buf; > > + sum += left; > > + } > > > > return sum; > > } > > -- > > 2.21.0.windows.1 > > > > This is correct for both big and little endian CPUs. > > Reviewed-by: Morten Brørup <m...@smartsharesystems.com>
Acked-by: Olivier Matz <olivier.m...@6wind.com> Thanks!
