hyperv: Add handling of IP header with option field in netvsc_set_hash()

In case that the IP header has optional field at the end, this patch will
get the port numbers after that field, and compute the hash. The general
parser skb_flow_dissect() is used here.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 16 deletions

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 0fcb5e7eb073..9e17d1a91e71 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -162,7 +162,7 @@ union sub_key {
  * data: network byte order
  * return: host byte order
  */
-static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
+static u32 comp_hash(u8 *key, int klen, void *data, int dlen)
 {
         union sub_key subk;
         int k_next = 4;
@@ -176,7 +176,7 @@ static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
         for (i = 0; i < dlen; i++) {
                 subk.kb = key[k_next];
                 k_next = (k_next + 1) % klen;
-                dt = data[i];
+                dt = ((u8 *)data)[i];
                 for (j = 0; j < 8; j++) {
                         if (dt & 0x80)
                                 ret ^= subk.ka;
@@ -190,26 +190,20 @@ static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
 
 static bool netvsc_set_hash(u32 *hash, struct sk_buff *skb)
 {
-        struct iphdr *iphdr;
+        struct flow_keys flow;
         int data_len;
-        bool ret = false;
 
-        if (eth_hdr(skb)->h_proto != htons(ETH_P_IP))
+        if (!skb_flow_dissect(skb, &flow) || flow.n_proto != htons(ETH_P_IP))
                 return false;
 
-        iphdr = ip_hdr(skb);
+        if (flow.ip_proto == IPPROTO_TCP)
+                data_len = 12;
+        else
+                data_len = 8;
 
-        if (iphdr->version == 4) {
-                if (iphdr->protocol == IPPROTO_TCP)
-                        data_len = 12;
-                else
-                        data_len = 8;
-                *hash = comp_hash(netvsc_hash_key, HASH_KEYLEN,
-                                  (u8 *)&iphdr->saddr, data_len);
-                ret = true;
-        }
+        *hash = comp_hash(netvsc_hash_key, HASH_KEYLEN, &flow, data_len);
 
-        return ret;
+        return true;
 }
 
 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,