[dpdk-stable] patch 'net: fix checksum on big endian CPUs' has been queued to stable release 19.11.4

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/26/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Luca Boccassi

---
>From 862bc496af14cd62856037a9a5c882ef47461e50 Mon Sep 17 00:00:00 2001
From: Hongzhi Guo <guohongzhi1 at huawei.com>
Date: Fri, 10 Jul 2020 19:43:13 +0800
Subject: [PATCH] net: fix checksum on big endian CPUs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

[ upstream commit 982bb68cab2b93724f9625d53c309e73fa194e6e ]

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")

Signed-off-by: Hongzhi Guo <guohongzhi1 at huawei.com>
Reviewed-by: Morten Brørup <mb at smartsharesystems.com>
Acked-by: Olivier Matz <olivier.matz at 6wind.com>
---
 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 6254c5cc6..0897da744 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;
 }
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-07-24 12:53:53.396197351 +0100
+++ 0126-net-fix-checksum-on-big-endian-CPUs.patch	2020-07-24 12:53:48.423008994 +0100
@@ -1,4 +1,4 @@
-From 982bb68cab2b93724f9625d53c309e73fa194e6e Mon Sep 17 00:00:00 2001
+From 862bc496af14cd62856037a9a5c882ef47461e50 Mon Sep 17 00:00:00 2001
 From: Hongzhi Guo <guohongzhi1 at huawei.com>
 Date: Fri, 10 Jul 2020 19:43:13 +0800
 Subject: [PATCH] net: fix checksum on big endian CPUs
@@ -6,6 +6,8 @@
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 
+[ upstream commit 982bb68cab2b93724f9625d53c309e73fa194e6e ]
+
 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.
@@ -18,7 +20,6 @@
 RFC 1071.
 
 Fixes: 6006818cfb26("net: new checksum functions")
-Cc: stable at dpdk.org
 
 Signed-off-by: Hongzhi Guo <guohongzhi1 at huawei.com>
 Reviewed-by: Morten Brørup <mb at smartsharesystems.com>
@@ -28,7 +29,7 @@
  1 file changed, 5 insertions(+), 2 deletions(-)
 
 diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
-index a9ffc3357..fcd1eb342 100644
+index 6254c5cc6..0897da744 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)