patches for DPDK stable branches
 help / color / mirror / Atom feed
* [dpdk-stable] [PATCH] net: fix unneeded replacement of 0 by ffff for TCP checksum
@ 2020-07-10  6:55 Hongzhi Guo
  2020-07-10 12:41 ` Olivier Matz
  0 siblings, 1 reply; 10+ messages in thread
From: Hongzhi Guo @ 2020-07-10  6:55 UTC (permalink / raw)
  To: dev
  Cc: stable, stephen, mb, thomas, olivier.matz, konstantin.ananyev,
	ferruh.yigit, nicolas.chautru, zhoujingbin, chenchanghu,
	jerry.lilijun, haifeng.lin, guohongzhi1

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)
@@ -344,7 +344,13 @@ rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
 
 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
 	cksum = (~cksum) & 0xffff;
-	if (cksum == 0)
+	/*
+	 *Per RFC768:
+	 *If the computed checksum is zero for udp,
+	 *it is transmitted as all ones.
+	 *(the equivalent in one's complement arithmetic).
+	 */
+	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
 		cksum = 0xffff;
 
 	return (uint16_t)cksum;
@@ -438,7 +444,13 @@ rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
 
 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
 	cksum = (~cksum) & 0xffff;
-	if (cksum == 0)
+	/*
+	 *Per RFC768:
+	 *If the computed checksum is zero for udp,
+	 *it is transmitted as all ones.
+	 *(the equivalent in one's complement arithmetic).
+	 */
+	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
 		cksum = 0xffff;
 
 	return (uint16_t)cksum;
-- 
2.21.0.windows.1



^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2020-07-10 21:03 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-10  6:55 [dpdk-stable] [PATCH] net: fix unneeded replacement of 0 by ffff for TCP checksum Hongzhi Guo
2020-07-10 12:41 ` Olivier Matz
2020-07-10 13:10   ` Morten Brørup
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

patches for DPDK stable branches

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://inbox.dpdk.org/stable \
		stable@dpdk.org
	public-inbox-index stable

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git