bonding: modify the old and add new xmit hash policies

This patch adds two new hash policy modes which use skb_flow_dissect:
3 - Encapsulated layer 2+3
4 - Encapsulated layer 3+4
There should be a good improvement for tunnel users in those modes.
It also changes the old hash functions to:
hash ^= (__force u32)flow.dst ^ (__force u32)flow.src;
hash ^= (hash >> 16);
hash ^= (hash >> 8);

Where hash will be initialized either to L2 hash, that is
SRCMAC[5] XOR DSTMAC[5], or to flow->ports which should be extracted
from the upper layer. Flow's dst and src are also extracted based on the
xmit policy either directly from the buffer or by using skb_flow_dissect,
but in both cases if the protocol is IPv6 then dst and src are obtained by
ipv6_addr_hash() on the real addresses. In case of a non-dissectable
packet, the algorithms fall back to L2 hashing.
The bond_set_mode_ops() function is now obsolete and thus deleted
because it was used only to set the proper hash policy. Also we trim a
pointer from struct bonding because we no longer need to keep the hash
function, now there's only a single hash function - bond_xmit_hash that
works based on bond->params.xmit_policy.

The hash function and skb_flow_dissect were suggested by Eric Dumazet.
The layer names were suggested by Andy Gospodarek, because I suck at
semantics.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 2 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index e06c644470b1..e9249527e7e7 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -318,7 +318,6 @@ static ssize_t bonding_store_mode(struct device *d,
 	/* don't cache arp_validate between modes */
 	bond->params.arp_validate = BOND_ARP_VALIDATE_NONE;
 	bond->params.mode = new_value;
-	bond_set_mode_ops(bond, bond->params.mode);
 	pr_info("%s: setting mode to %s (%d).\n",
 		bond->dev->name, bond_mode_tbl[new_value].modename,
 		new_value);
@@ -358,7 +357,6 @@ static ssize_t bonding_store_xmit_hash(struct device *d,
 		ret = -EINVAL;
 	} else {
 		bond->params.xmit_policy = new_value;
-		bond_set_mode_ops(bond, bond->params.mode);
 		pr_info("%s: setting xmit hash policy to %s (%d).\n",
 			bond->dev->name,
 			xmit_hashtype_tbl[new_value].modename, new_value);