diff mbox series

net/virtio: deduce IP length for Virtio TSO checksum

Message ID 20230216123554.2628837-1-boleslav.stankevich@oktetlabs.ru (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series net/virtio: deduce IP length for Virtio TSO checksum |

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/loongarch-compilation success Compilation OK
ci/loongarch-unit-testing success Unit Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-broadcom-Functional fail Functional Testing issues
ci/iol-broadcom-Performance success Performance Testing PASS
ci/iol-intel-Functional fail Functional Testing issues
ci/iol-intel-Performance success Performance Testing PASS
ci/github-robot: build success github build: passed
ci/iol-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-abi-testing success Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS

Commit Message

Boleslav Stankevich Feb. 16, 2023, 12:35 p.m. UTC 
  The length of TSO payload could not fit into 16 bits provided by the
IPv4 total length and IPv6 payload length fields. Thus, deduce it
from the length of the packet.

Signed-off-by: Boleslav Stankevich <boleslav.stankevich@oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 drivers/net/virtio/virtio_rxtx.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 2d0afd3302..e48ff3cca7 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -404,29 +404,36 @@  virtio_tso_fix_cksum(struct rte_mbuf *m)
 	if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
 			m->l4_len)) {
 		struct rte_ipv4_hdr *iph;
-		struct rte_ipv6_hdr *ip6h;
 		struct rte_tcp_hdr *th;
-		uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
+		uint16_t prev_cksum, new_cksum;
+		uint32_t ip_paylen;
 		uint32_t tmp;
 
 		iph = rte_pktmbuf_mtod_offset(m,
 					struct rte_ipv4_hdr *, m->l2_len);
 		th = RTE_PTR_ADD(iph, m->l3_len);
+
+		/*
+		 * Calculate IPv4 header checksum with current total length value
+		 * (whatever it is) to have correct checksum after update on edits
+		 * done by TSO.
+		 */
 		if ((iph->version_ihl >> 4) == 4) {
 			iph->hdr_checksum = 0;
 			iph->hdr_checksum = rte_ipv4_cksum(iph);
-			ip_len = iph->total_length;
-			ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
-				m->l3_len);
-		} else {
-			ip6h = (struct rte_ipv6_hdr *)iph;
-			ip_paylen = ip6h->payload_len;
 		}
 
+		/*
+		 * Do not use IPv4 total length and IPv6 payload length fields to get
+		 * TSO payload length since it could not fit into 16 bits.
+		 */
+		ip_paylen = rte_cpu_to_be_32(rte_pktmbuf_pkt_len(m) - m->l2_len -
+					m->l3_len);
+
 		/* calculate the new phdr checksum not including ip_paylen */
 		prev_cksum = th->cksum;
 		tmp = prev_cksum;
-		tmp += ip_paylen;
+		tmp += (ip_paylen & 0xffff) + (ip_paylen >> 16);
 		tmp = (tmp & 0xffff) + (tmp >> 16);
 		new_cksum = tmp;