bonding: Add new layer2+3 hash for xor/802.3ad modes

 	Add new hash for balance-xor and 802.3ad modes.  Originally
 submitted by "Glenn Griffin" <ggriffin.kernel@gmail.com>; modified by
 Jay Vosburgh to move setting of hash policy out of line, tweak the
 documentation update and add version update to 3.2.2.

	Glenn's original comment follows:

Included is a patch for a new xmit_hash_policy for the bonding driver
that selects slaves based on MAC and IP information.  This is a middle
ground between what currently exists in the layer2 only policy and the
layer3+4 policy.  This policy strives to be fully 802.3ad compliant by
transmitting every packet of any particular flow over the same link.
As documented the layer3+4 policy is not fully compliant for extreme
cases such as ip fragmentation, so this policy is a nice compromise
for environments that require full compliance but desire more than the
layer2 only policy.

Signed-off-by: "Glenn Griffin" <ggriffin.kernel@gmail.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

4 files changed, 69 insertions, 15 deletions

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 11340625e363..6cc30e0d5795 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -554,6 +554,30 @@ xmit_hash_policy
 
                 This algorithm is 802.3ad compliant.
 
+        layer2+3
+
+                This policy uses a combination of layer2 and layer3
+                protocol information to generate the hash.
+
+                Uses XOR of hardware MAC addresses and IP addresses to
+                generate the hash.  The formula is
+
+                (((source IP XOR dest IP) AND 0xffff) XOR
+                        ( source MAC XOR destination MAC ))
+                                modulo slave count
+
+                This algorithm will place all traffic to a particular
+                network peer on the same slave.  For non-IP traffic,
+                the formula is the same as for the layer2 transmit
+                hash policy.
+
+                This policy is intended to provide a more balanced
+                distribution of traffic than layer2 alone, especially
+                in environments where a layer3 gateway device is
+                required to reach most destinations.
+
+                This algorithm is 802.3ad complient.
+
         layer3+4
 
                 This policy uses upper layer protocol information,
@@ -589,8 +613,9 @@ xmit_hash_policy
                 or may not tolerate this noncompliance.
 
         The default value is layer2.  This option was added in bonding
-version 2.6.3.  In earlier versions of bonding, this parameter does
-not exist, and the layer2 policy is the only policy.
+        version 2.6.3.  In earlier versions of bonding, this parameter
+        does not exist, and the layer2 policy is the only policy.  The
+        layer2+3 value was added for bonding version 3.2.2.
 
 
 3. Configuring Bonding Devices
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e4a47149735f..08879d552ae0 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -175,6 +175,7 @@ struct bond_parm_tbl bond_mode_tbl[] = {
 struct bond_parm_tbl xmit_hashtype_tbl[] = {
 {       "layer2",               BOND_XMIT_POLICY_LAYER2},
 {       "layer3+4",             BOND_XMIT_POLICY_LAYER34},
+{       "layer2+3",             BOND_XMIT_POLICY_LAYER23},
 {       NULL,                   -1},
 };
 
@@ -3605,6 +3606,24 @@ void bond_unregister_arp(struct bonding *bond)
 /*---------------------------- Hashing Policies -----------------------------*/
 
 /*
+ * Hash for the output device based upon layer 2 and layer 3 data. If
+ * the packet is not IP mimic bond_xmit_hash_policy_l2()
+ */
+static int bond_xmit_hash_policy_l23(struct sk_buff *skb,
+                                     struct net_device *bond_dev, int count)
+{
+        struct ethhdr *data = (struct ethhdr *)skb->data;
+        struct iphdr *iph = ip_hdr(skb);
+
+        if (skb->protocol == __constant_htons(ETH_P_IP)) {
+                return ((ntohl(iph->saddr ^ iph->daddr) & 0xffff) ^
+                        (data->h_dest[5] ^ bond_dev->dev_addr[5])) % count;
+        }
+
+        return (data->h_dest[5] ^ bond_dev->dev_addr[5]) % count;
+}
+
+/*
  * Hash for the output device based upon layer 3 and layer 4 data. If
  * the packet is a frag or not TCP or UDP, just use layer 3 data.  If it is
  * altogether not IP, mimic bond_xmit_hash_policy_l2()
@@ -4306,6 +4325,22 @@ out:
 
 /*------------------------- Device initialization ---------------------------*/
 
+static void bond_set_xmit_hash_policy(struct bonding *bond)
+{
+        switch (bond->params.xmit_policy) {
+        case BOND_XMIT_POLICY_LAYER23:
+                bond->xmit_hash_policy = bond_xmit_hash_policy_l23;
+                break;
+        case BOND_XMIT_POLICY_LAYER34:
+                bond->xmit_hash_policy = bond_xmit_hash_policy_l34;
+                break;
+        case BOND_XMIT_POLICY_LAYER2:
+        default:
+                bond->xmit_hash_policy = bond_xmit_hash_policy_l2;
+                break;
+        }
+}
+
 /*
  * set bond mode specific net device operations
  */
@@ -4322,10 +4357,7 @@ void bond_set_mode_ops(struct bonding *bond, int mode)
                 break;
         case BOND_MODE_XOR:
                 bond_dev->hard_start_xmit = bond_xmit_xor;
-                if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER34)
-                        bond->xmit_hash_policy = bond_xmit_hash_policy_l34;
-                else
-                        bond->xmit_hash_policy = bond_xmit_hash_policy_l2;
+                bond_set_xmit_hash_policy(bond);
                 break;
         case BOND_MODE_BROADCAST:
                 bond_dev->hard_start_xmit = bond_xmit_broadcast;
@@ -4333,10 +4365,7 @@ void bond_set_mode_ops(struct bonding *bond, int mode)
         case BOND_MODE_8023AD:
                 bond_set_master_3ad_flags(bond);
                 bond_dev->hard_start_xmit = bond_3ad_xmit_xor;
-                if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER34)
-                        bond->xmit_hash_policy = bond_xmit_hash_policy_l34;
-                else
-                        bond->xmit_hash_policy = bond_xmit_hash_policy_l2;
+                bond_set_xmit_hash_policy(bond);
                 break;
         case BOND_MODE_ALB:
                 bond_set_master_alb_flags(bond);
@@ -4498,8 +4527,7 @@ int bond_parse_parm(char *mode_arg, struct bond_parm_tbl *tbl)
         for (i = 0; tbl[i].modename; i++) {
                 if ((isdigit(*mode_arg) &&
                      tbl[i].mode == simple_strtol(mode_arg, NULL, 0)) ||
-                    (strncmp(mode_arg, tbl[i].modename,
-                             strlen(tbl[i].modename)) == 0)) {
+                    (strcmp(mode_arg, tbl[i].modename) == 0)) {
                         return tbl[i].mode;
                 }
         }
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 61c1b4536d34..ccafc74c5a2b 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -22,8 +22,8 @@
 #include "bond_3ad.h"
 #include "bond_alb.h"
 
-#define DRV_VERSION     "3.2.1"
-#define DRV_RELDATE     "October 15, 2007"
+#define DRV_VERSION     "3.2.2"
+#define DRV_RELDATE     "December 6, 2007"
 #define DRV_NAME        "bonding"
 #define DRV_DESCRIPTION "Ethernet Channel Bonding Driver"
 
diff --git a/include/linux/if_bonding.h b/include/linux/if_bonding.h
index 84598fa2e9de..65c2d247068b 100644
--- a/include/linux/if_bonding.h
+++ b/include/linux/if_bonding.h
@@ -85,7 +85,8 @@
 
 /* hashing types */
 #define BOND_XMIT_POLICY_LAYER2         0 /* layer 2 (MAC only), default */
-#define BOND_XMIT_POLICY_LAYER34        1 /* layer 3+4 (IP ^ MAC) */
+#define BOND_XMIT_POLICY_LAYER34        1 /* layer 3+4 (IP ^ (TCP || UDP)) */
+#define BOND_XMIT_POLICY_LAYER23        2 /* layer 2+3 (IP ^ MAC) */
 
 typedef struct ifbond {
         __s32 bond_mode;