Re: [PATCH] bnx2x: dont dereference tcp header on non tcp frames

Dmitry Kravkov
2011-04-20T09:41:26Z

On Wed, 2011-04-20 at 01:46 -0700, David Miller wrote:
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Wed, 20 Apr 2011 09:31:53 +0200
>
> > [PATCH] bnx2x: dont dereference tcp header on non tcp frames
> >
> > bnx2x_set_pbd_csum() & bnx2x_set_pbd_csum_e2() use
> > tcp_hdrlen(skb) even for non TCP frames
> >
> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
>
> Broadcom folks please review.
>

Following patch fixes udp checksum offload flow and also addresses
issues raised by Eric. We are testing it now.

From: Vladislav Zolotarov <vladz@broadcom.com>

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
---
drivers/net/bnx2x/bnx2x_cmn.c | 34 ++++++++++++++++++++++++----------
1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/net/bnx2x/bnx2x_cmn.c b/drivers/net/bnx2x/bnx2x_cmn.c
index e83ac6d..16581df 100644
--- a/drivers/net/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/bnx2x/bnx2x_cmn.c
@@ -2019,15 +2019,23 @@ static inline void bnx2x_set_pbd_gso(struct sk_buff *skb,
static inline u8 bnx2x_set_pbd_csum_e2(struct bnx2x *bp, struct sk_buff *skb,
u32 *parsing_data, u32 xmit_type)
{
- *parsing_data |= ((tcp_hdrlen(skb)/4) <<
- ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW_SHIFT) &
- ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW;
+ *parsing_data |=
+ ((((u8 *)skb_transport_header(skb) - skb->data) >> 1) <<
+ ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W_SHIFT) &
+ ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W;

- *parsing_data |= ((((u8 *)tcp_hdr(skb) - skb->data) / 2) <<
- ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W_SHIFT) &
- ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W;
+ if (xmit_type & XMIT_CSUM_TCP) {
+ *parsing_data |= ((tcp_hdrlen(skb) / 4) <<
+ ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW_SHIFT) &
+ ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW;

- return skb_transport_header(skb) + tcp_hdrlen(skb) - skb->data;
+ return skb_transport_header(skb) + tcp_hdrlen(skb) - skb->data;
+ } else
+ /* We support checksum offload for TCP and UDP only.
+ * No need to pass the UDP header length - it's a constant.
+ */
+ return skb_transport_header(skb) +
+ sizeof(struct udphdr) - skb->data;
}

/**
@@ -2043,7 +2051,7 @@ static inline u8 bnx2x_set_pbd_csum(struct bnx2x *bp, struct sk_buff *skb,
struct eth_tx_parse_bd_e1x *pbd,
u32 xmit_type)
{
- u8 hlen = (skb_network_header(skb) - skb->data) / 2;
+ u8 hlen = (skb_network_header(skb) - skb->data) >> 1;

/* for now NS flag is not used in Linux */
pbd->global_data =
@@ -2051,9 +2059,15 @@ static inline u8 bnx2x_set_pbd_csum(struct bnx2x *bp, struct sk_buff *skb,
ETH_TX_PARSE_BD_E1X_LLC_SNAP_EN_SHIFT));

pbd->ip_hlen_w = (skb_transport_header(skb) -
- skb_network_header(skb)) / 2;
+ skb_network_header(skb)) >> 1;

- hlen += pbd->ip_hlen_w + tcp_hdrlen(skb) / 2;
+ hlen += pbd->ip_hlen_w;
+
+ /* We support checksum offload for TCP and UDP only */
+ if (xmit_type & XMIT_CSUM_TCP)
+ hlen += tcp_hdrlen(skb) / 2;
+ else
+ hlen += sizeof(struct udphdr) / 2;

pbd->total_hlen_w = cpu_to_le16(hlen);
hlen = hlen*2;
--
1.7.2.2