net: Add utility functions to clear rxhash

In several places 'skb->rxhash = 0' is being done to clear the
rxhash value in an skb.  This does not clear l4_rxhash which could
still be set so that the rxhash wouldn't be recalculated on subsequent
call to skb_get_rxhash.  This patch adds an explict function to clear
all the rxhash related information in the skb properly.

skb_clear_hash_if_not_l4 clears the rxhash only if it is not marked as
l4_rxhash.

Fixed up places where 'skb->rxhash = 0' was being called.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 4 deletions

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 2481993a4970..c10a3ce5cbff 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -704,7 +704,7 @@ struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
                         memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
                         if (ip_defrag(skb, user))
                                 return NULL;
-                        skb->rxhash = 0;
+                        skb_clear_hash(skb);
                 }
         }
         return skb;
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 42ffbc8d65c6..6156f4ef5e91 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -56,7 +56,7 @@ int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
 
         skb_scrub_packet(skb, xnet);
 
-        skb->rxhash = 0;
+        skb_clear_hash(skb);
         skb_dst_set(skb, &rt->dst);
         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 
@@ -107,8 +107,7 @@ int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
 
         nf_reset(skb);
         secpath_reset(skb);
-        if (!skb->l4_rxhash)
-                skb->rxhash = 0;
+        skb_clear_hash_if_not_l4(skb);
         skb_dst_drop(skb);
         skb->vlan_tci = 0;
         skb_set_queue_mapping(skb, 0);