[ 088/108] bnx2x: fix checksum validation

Ben Hutchings
2012-07-23T01:42:50Z

From: Eric Dumazet <edumazet@google.com>

commit d6cb3e41386f20fb0777d0b59a2def82c65d37f7 upstream.

bnx2x driver incorrectly sets ip_summed to CHECKSUM_UNNECESSARY on
encapsulated segments. TCP stack happily accepts frames with bad
checksums, if they are inside a GRE or IPIP encapsulation.

Our understanding is that if no IP or L4 csum validation was done by the
hardware, we should leave ip_summed as is (CHECKSUM_NONE), since
hardware doesn't provide CHECKSUM_COMPLETE support in its cqe.

Then, if IP/L4 checksumming was done by the hardware, set
CHECKSUM_UNNECESSARY if no error was flagged.

Patch based on findings and analysis from Robert Evans

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Yaniv Rosner <yanivr@broadcom.com>
Cc: Merav Sicron <meravs@broadcom.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Robert Evans <evansr@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 15 -------------
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 27 ++++++++++++++++++-----
2 files changed, 21 insertions(+), 21 deletions(-)

--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -723,21 +723,6 @@ struct bnx2x_fastpath {

#define ETH_RX_ERROR_FALGS ETH_FAST_PATH_RX_CQE_PHY_DECODE_ERR_FLG

-#define BNX2X_IP_CSUM_ERR(cqe) \
- (!((cqe)->fast_path_cqe.status_flags & \
- ETH_FAST_PATH_RX_CQE_IP_XSUM_NO_VALIDATION_FLG) && \
- ((cqe)->fast_path_cqe.type_error_flags & \
- ETH_FAST_PATH_RX_CQE_IP_BAD_XSUM_FLG))
-
-#define BNX2X_L4_CSUM_ERR(cqe) \
- (!((cqe)->fast_path_cqe.status_flags & \
- ETH_FAST_PATH_RX_CQE_L4_XSUM_NO_VALIDATION_FLG) && \
- ((cqe)->fast_path_cqe.type_error_flags & \
- ETH_FAST_PATH_RX_CQE_L4_BAD_XSUM_FLG))
-
-#define BNX2X_RX_CSUM_OK(cqe) \
- (!(BNX2X_L4_CSUM_ERR(cqe) || BNX2X_IP_CSUM_ERR(cqe)))
-
#define BNX2X_PRS_FLAG_OVERETH_IPV4(flags) \
(((le16_to_cpu(flags) & \
PARSING_FLAGS_OVER_ETHERNET_PROTOCOL) >> \
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -551,6 +551,26 @@ static inline void bnx2x_set_skb_rxhash(
le32_to_cpu(cqe->fast_path_cqe.rss_hash_result);
}

+static void bnx2x_csum_validate(struct sk_buff *skb, union eth_rx_cqe *cqe,
+ struct bnx2x_fastpath *fp)
+{
+ /* Do nothing if no IP/L4 csum validation was done */
+
+ if (cqe->fast_path_cqe.status_flags &
+ (ETH_FAST_PATH_RX_CQE_IP_XSUM_NO_VALIDATION_FLG |
+ ETH_FAST_PATH_RX_CQE_L4_XSUM_NO_VALIDATION_FLG))
+ return;
+
+ /* If both IP/L4 validation were done, check if an error was found. */
+
+ if (cqe->fast_path_cqe.type_error_flags &
+ (ETH_FAST_PATH_RX_CQE_IP_BAD_XSUM_FLG |
+ ETH_FAST_PATH_RX_CQE_L4_BAD_XSUM_FLG))
+ fp->eth_q_stats.hw_csum_err++;
+ else
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+}
+
int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget)
{
struct bnx2x *bp = fp->bp;
@@ -746,13 +766,9 @@ reuse_rx:

skb_checksum_none_assert(skb);

- if (bp->dev->features & NETIF_F_RXCSUM) {
+ if (bp->dev->features & NETIF_F_RXCSUM)
+ bnx2x_csum_validate(skb, cqe, fp);

- if (likely(BNX2X_RX_CSUM_OK(cqe)))
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- else
- fp->eth_q_stats.hw_csum_err++;
- }
}

skb_record_rx_queue(skb, fp->index);