From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Olivier Matz" <olivier.matz@6wind.com>,
"Hongzhi Guo" <guohongzhi1@huawei.com>
Cc: <dev@dpdk.org>, <stable@dpdk.org>, <stephen@networkplumber.org>,
<thomas@monjalon.net>, <konstantin.ananyev@intel.com>,
<ferruh.yigit@intel.com>, <nicolas.chautru@intel.com>,
<zhoujingbin@huawei.com>, <chenchanghu@huawei.com>,
<jerry.lilijun@huawei.com>, <haifeng.lin@huawei.com>
Subject: Re: [dpdk-stable] [PATCH] net: fix unneeded replacement of 0 by ffff for TCP checksum
Date: Fri, 10 Jul 2020 15:10:34 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35C61118@smartserver.smartshare.dk> (raw)
In-Reply-To: <20200710124109.GY5869@platinum>
> From: Olivier Matz [mailto:olivier.matz@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: stable@dpdk.org
> >
> > Signed-off-by: Hongzhi Guo <guohongzhi1@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 <mb@smartsharesystems.com>
next prev parent reply other threads:[~2020-07-10 13:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 6:55 Hongzhi Guo
2020-07-10 12:41 ` Olivier Matz
2020-07-10 13:10 ` Morten Brørup [this message]
2020-07-10 13:16 ` Olivier Matz
2020-07-10 13:29 ` Morten Brørup
2020-07-10 13:41 ` Olivier Matz
2020-07-10 13:56 ` [dpdk-stable] [dpdk-dev] " Morten Brørup
2020-07-10 14:40 ` Olivier Matz
2020-07-10 14:52 ` Olivier Matz
2020-07-10 21:03 ` Thomas Monjalon
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