bugfix: udptcp_checksum should tread tcp and udp differently
diff mbox series

Message ID 20200527144003.3592-1-guohongzhi1@huawei.com
State Superseded
Delegated to: Thomas Monjalon
Headers show
Series
  • bugfix: udptcp_checksum should tread tcp and udp differently
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ci/Intel-compilation success Compilation OK
ci/iol-testing warning Testing issues
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Commit Message

Hongzhi Guo May 27, 2020, 2:40 p.m. UTC
RFC 768 for UDP specifies:
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.

RFC 793 for TCP has no such special treatment for the checksum of zero.

Signed-off-by: guohongzhi <guohongzhi1@huawei.com>
---
 lib/librte_net/rte_ip.h | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Patch
diff mbox series

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 1ceb7b7..8bef313 100644
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -324,8 +324,7 @@  rte_ipv4_phdr_cksum(const struct rte_ipv4_hdr *ipv4_hdr, uint64_t ol_flags)
  * @param l4_hdr
  *   The pointer to the beginning of the L4 header.
  * @return
- *   The complemented checksum to set in the IP packet
- *   or 0 on error
+ *   The complemented checksum to set in the IP packet.
  */
 static inline uint16_t
 rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
@@ -344,7 +343,10 @@  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)
+	/* For Udp, if the computed checksum is zero,
+	 * it is transmitted as all ones.RFC768
+	 */
+	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
 		cksum = 0xffff;
 
 	return (uint16_t)cksum;
@@ -436,7 +438,10 @@  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)
+	/* For Udp, if the computed checksum is zero,
+	 * it is transmitted as all ones.RFC768
+	 */
+	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
 		cksum = 0xffff;
 
 	return (uint16_t)cksum;