bnx2x: fix UDP csum offload

Fixed packets parameters for FW in UDP checksum offload flow.

Do not dereference TCP headers on non TCP frames.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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;