[Bionic PATCH 03/19] ibmvnic: Include header descriptor support for ARP packets

[Thadeu Lima de Souza Cascardo]

From: Thomas Falcon <tlfalcon at linux.vnet.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1748517

In recent tests with new adapters, it was discovered that ARP
packets were not being properly processed. This patch adds
support for ARP packet headers to be passed to backing adapters,
if necessary.

Signed-off-by: Thomas Falcon <tlfalcon at linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 4eb50ceb5c156a166c0b00ac27f0ff3a0943cdfb)
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index c220e1016bec..e126de019243 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -59,6 +59,7 @@
 #include <linux/mm.h>
 #include <linux/ethtool.h>
 #include <linux/proc_fs.h>
+#include <linux/if_arp.h>
 #include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
@@ -1177,6 +1178,9 @@ static int build_hdr_data(u8 hdr_field, struct sk_buff *skb,
 			hdr_len[2] = tcp_hdrlen(skb);
 		else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
 			hdr_len[2] = sizeof(struct udphdr);
+	} else if (skb->protocol == htons(ETH_P_ARP)) {
+		hdr_len[1] = arp_hdr_len(skb->dev);
+		hdr_len[2] = 0;
 	}
 
 	memset(hdr_data, 0, 120);
@@ -1412,7 +1416,8 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	/* determine if l2/3/4 headers are sent to firmware */
 	if ((*hdrs >> 7) & 1 &&
 	    (skb->protocol == htons(ETH_P_IP) ||
-	     skb->protocol == htons(ETH_P_IPV6))) {
+	     skb->protocol == htons(ETH_P_IPV6) ||
+	     skb->protocol == htons(ETH_P_ARP))) {
 		build_hdr_descs_arr(tx_buff, &num_entries, *hdrs);
 		tx_crq.v1.n_crq_elem = num_entries;
 		tx_buff->indir_arr[0] = tx_crq;
-- 
2.15.1