[dpdk-dev] [PATCH] net/ena: fix L4 cksum flags condition for TX
Maciej Bielski
mba at semihalf.com
Thu Aug 1 13:45:36 CEST 2019
During an if-condition evaluation, a 2-bit flag evaluates to 'true' for
'0x1', '0x2' and '0x3'. Thus, from this perspective these flags are
indistinguishable. To make them distinct, respective bits must be
extracted with a mask and then checked for strict equality.
Specifically here, even if `PKT_TX_UDP_CKSUM` (value '0x3') was set, the
expression `mbuf->ol_flags & PKT_TX_TCP` (the second flag of value
'0x1') is evaluated first and the result is 'true'. In consequence, for
UDP packets the execution flow enters an incorrect branch.
Fixes: 56b8b9b7e5d2 (net/ena: convert to new Tx offloads API)
Cc: stable at dpdk.org
Signed-off-by: Maciej Bielski <mba at semihalf.com>
Reported-by: Eduard Serra <eduser25 at gmail.com>
---
drivers/net/ena/ena_ethdev.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index f58334080..eb9d643f0 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -330,12 +330,13 @@ static inline void ena_tx_mbuf_prepare(struct rte_mbuf *mbuf,
}
/* check if L4 checksum is needed */
- if ((mbuf->ol_flags & PKT_TX_TCP_CKSUM) &&
+ if (((mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM) &&
(queue_offloads & DEV_TX_OFFLOAD_TCP_CKSUM)) {
ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_TCP;
ena_tx_ctx->l4_csum_enable = true;
- } else if ((mbuf->ol_flags & PKT_TX_UDP_CKSUM) &&
- (queue_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)) {
+ } else if (((mbuf->ol_flags & PKT_TX_L4_MASK) ==
+ PKT_TX_UDP_CKSUM) &&
+ (queue_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)) {
ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_UDP;
ena_tx_ctx->l4_csum_enable = true;
} else {
--
2.20.1
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