bonding: xor/802.3ad improved slave hash

Add support for alternate slave selection algorithms to bonding
balance-xor and 802.3ad modes.  Default mode (what we have now: xor of
MAC addresses) is "layer2", new choice is "layer3+4", using IP and port
information for hashing to select peer.

Originally submitted by Jason Gabler for balance-xor mode;
modified by Jay Vosburgh to additionally support 802.3ad mode.  Jason's
original comment is as follows:

The attached patch to the Linux Etherchannel Bonding driver modifies the
driver's "balance-xor" mode as follows:

      - alternate hashing policy support for mode 2
        * Added kernel parameter "xmit_policy" to allow the specification
          of different hashing policies for mode 2.  The original mode 2
          policy is the default, now found in xmit_hash_policy_layer2().
        * Added xmit_hash_policy_layer34()

This patch was inspired by hashing policies implemented by Cisco,
Foundry and IBM, which are explained in
Foundry documentation found at:
http://www.foundrynet.com/services/documentation/sribcg/Trunking.html#112750

Signed-off-by: Jason Gabler <jygabler@lbl.gov>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 6558af22eda4..d27f377b3eeb 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -25,6 +25,10 @@
  *
  * 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
  *	- Code cleanup and style changes
+ *
+ * 2005/05/05 - Jason Gabler <jygabler at lbl dot gov>
+ *      - added "xmit_policy" kernel parameter for alternate hashing policy
+ *	  support for mode 2
  */
 
 #ifndef _LINUX_BONDING_H
@@ -36,8 +40,8 @@
 #include "bond_3ad.h"
 #include "bond_alb.h"
 
-#define DRV_VERSION	"2.6.2"
-#define DRV_RELDATE	"June 5, 2005"
+#define DRV_VERSION	"2.6.3"
+#define DRV_RELDATE	"June 8, 2005"
 #define DRV_NAME	"bonding"
 #define DRV_DESCRIPTION	"Ethernet Channel Bonding Driver"
 
@@ -137,6 +141,7 @@
 
 struct bond_params {
 	int mode;
+	int xmit_policy;
 	int miimon;
 	int arp_interval;
 	int use_carrier;
@@ -198,6 +203,7 @@ struct bonding {
 #endif /* CONFIG_PROC_FS */
 	struct   list_head bond_list;
 	struct   dev_mc_list *mc_list;
+	int      (*xmit_hash_policy)(struct sk_buff *, struct net_device *, int);
 	u32      master_ip;
 	u16      flags;
 	struct   ad_bond_info ad_info;