bonding: gratuitous ARP
authorJay Vosburgh <fubar@us.ibm.com>
Sun, 26 Jun 2005 21:52:20 +0000 (17:52 -0400)
committerJeff Garzik <jgarzik@pobox.com>
Sun, 26 Jun 2005 21:52:20 +0000 (17:52 -0400)
Add support for generating gratuitous ARPs in bonding
active-backup mode when failovers occur.  Includes support for VLAN
tagging the ARPs as needed.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
drivers/net/bonding/bond_main.c
drivers/net/bonding/bonding.h

index 269a5e4..545f6fe 100644 (file)
  *        Solution is to move call to dev_remove_pack outside of the
  *        spinlock.
  *        Set version to 2.6.1.
- *
+ * 2005/06/05 - Jay Vosburgh <fubar@us.ibm.com>
+ *     - Support for generating gratuitous ARPs in active-backup mode.
+ *       Includes support for VLAN tagging all bonding-generated ARPs
+ *       as needed.  Set version to 2.6.2.
  */
 
 //#define BONDING_DEBUG 1
 #include <linux/ethtool.h>
 #include <linux/if_vlan.h>
 #include <linux/if_bonding.h>
+#include <net/route.h>
 #include "bonding.h"
 #include "bond_3ad.h"
 #include "bond_alb.h"
@@ -574,7 +578,6 @@ static struct proc_dir_entry *bond_proc_dir = NULL;
 
 static u32 arp_target[BOND_MAX_ARP_TARGETS] = { 0, } ;
 static int arp_ip_count        = 0;
-static u32 my_ip       = 0;
 static int bond_mode   = BOND_MODE_ROUNDROBIN;
 static int lacp_fast   = 0;
 static int app_abi_ver = 0;
@@ -611,6 +614,7 @@ static struct bond_parm_tbl bond_mode_tbl[] = {
 /*-------------------------- Forward declarations ---------------------------*/
 
 static inline void bond_set_mode_ops(struct net_device *bond_dev, int mode);
+static void bond_send_gratuitous_arp(struct bonding *bond);
 
 /*---------------------------- General routines -----------------------------*/
 
@@ -659,6 +663,7 @@ static int bond_add_vlan(struct bonding *bond, unsigned short vlan_id)
 
        INIT_LIST_HEAD(&vlan->vlan_list);
        vlan->vlan_id = vlan_id;
+       vlan->vlan_ip = 0;
 
        write_lock_bh(&bond->lock);
 
@@ -1468,16 +1473,6 @@ static void bond_change_active_slave(struct bonding *bond, struct slave *new_act
                }
        }
 
-       if (bond->params.mode == BOND_MODE_ACTIVEBACKUP) {
-               if (old_active) {
-                       bond_set_slave_inactive_flags(old_active);
-               }
-
-               if (new_active) {
-                       bond_set_slave_active_flags(new_active);
-               }
-       }
-
        if (USES_PRIMARY(bond->params.mode)) {
                bond_mc_swap(bond, new_active, old_active);
        }
@@ -1488,6 +1483,17 @@ static void bond_change_active_slave(struct bonding *bond, struct slave *new_act
        } else {
                bond->curr_active_slave = new_active;
        }
+
+       if (bond->params.mode == BOND_MODE_ACTIVEBACKUP) {
+               if (old_active) {
+                       bond_set_slave_inactive_flags(old_active);
+               }
+
+               if (new_active) {
+                       bond_set_slave_active_flags(new_active);
+               }
+               bond_send_gratuitous_arp(bond);
+       }
 }
 
 /**
@@ -2694,15 +2700,180 @@ out:
        read_unlock(&bond->lock);
 }
 
+
+static u32 bond_glean_dev_ip(struct net_device *dev)
+{
+       struct in_device *idev;
+       struct in_ifaddr *ifa;
+       u32 addr = 0;
+
+       if (!dev)
+               return 0;
+
+       rcu_read_lock();
+       idev = __in_dev_get(dev);
+       if (!idev)
+               goto out;
+
+       ifa = idev->ifa_list;
+       if (!ifa)
+               goto out;
+
+       addr = ifa->ifa_local;
+out:
+       rcu_read_unlock();
+       return addr;
+}
+
+static int bond_has_ip(struct bonding *bond)
+{
+       struct vlan_entry *vlan, *vlan_next;
+
+       if (bond->master_ip)
+               return 1;
+
+       if (list_empty(&bond->vlan_list))
+               return 0;
+
+       list_for_each_entry_safe(vlan, vlan_next, &bond->vlan_list,
+                                vlan_list) {
+               if (vlan->vlan_ip)
+                       return 1;
+       }
+
+       return 0;
+}
+
+/*
+ * We go to the (large) trouble of VLAN tagging ARP frames because
+ * switches in VLAN mode (especially if ports are configured as
+ * "native" to a VLAN) might not pass non-tagged frames.
+ */
+static void bond_arp_send(struct net_device *slave_dev, int arp_op, u32 dest_ip, u32 src_ip, unsigned short vlan_id)
+{
+       struct sk_buff *skb;
+
+       dprintk("arp %d on slave %s: dst %x src %x vid %d\n", arp_op,
+              slave_dev->name, dest_ip, src_ip, vlan_id);
+              
+       skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
+                        NULL, slave_dev->dev_addr, NULL);
+
+       if (!skb) {
+               printk(KERN_ERR DRV_NAME ": ARP packet allocation failed\n");
+               return;
+       }
+       if (vlan_id) {
+               skb = vlan_put_tag(skb, vlan_id);
+               if (!skb) {
+                       printk(KERN_ERR DRV_NAME ": failed to insert VLAN tag\n");
+                       return;
+               }
+       }
+       arp_xmit(skb);
+}
+
+
 static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 {
-       int i;
+       int i, vlan_id, rv;
        u32 *targets = bond->params.arp_targets;
+       struct vlan_entry *vlan, *vlan_next;
+       struct net_device *vlan_dev;
+       struct flowi fl;
+       struct rtable *rt;
 
        for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
-               arp_send(ARPOP_REQUEST, ETH_P_ARP, targets[i], slave->dev,
-                        my_ip, NULL, slave->dev->dev_addr,
-                        NULL);
+               dprintk("basa: target %x\n", targets[i]);
+               if (list_empty(&bond->vlan_list)) {
+                       dprintk("basa: empty vlan: arp_send\n");
+                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
+                                     bond->master_ip, 0);
+                       continue;
+               }
+
+               /*
+                * If VLANs are configured, we do a route lookup to
+                * determine which VLAN interface would be used, so we
+                * can tag the ARP with the proper VLAN tag.
+                */
+               memset(&fl, 0, sizeof(fl));
+               fl.fl4_dst = targets[i];
+               fl.fl4_tos = RTO_ONLINK;
+
+               rv = ip_route_output_key(&rt, &fl);
+               if (rv) {
+                       if (net_ratelimit()) {
+                               printk(KERN_WARNING DRV_NAME
+                            ": %s: no route to arp_ip_target %u.%u.%u.%u\n",
+                                      bond->dev->name, NIPQUAD(fl.fl4_dst));
+                       }
+                       continue;
+               }
+
+               /*
+                * This target is not on a VLAN
+                */
+               if (rt->u.dst.dev == bond->dev) {
+                       dprintk("basa: rtdev == bond->dev: arp_send\n");
+                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
+                                     bond->master_ip, 0);
+                       continue;
+               }
+
+               vlan_id = 0;
+               list_for_each_entry_safe(vlan, vlan_next, &bond->vlan_list,
+                                        vlan_list) {
+                       vlan_dev = bond->vlgrp->vlan_devices[vlan->vlan_id];
+                       if (vlan_dev == rt->u.dst.dev) {
+                               vlan_id = vlan->vlan_id;
+                               dprintk("basa: vlan match on %s %d\n",
+                                      vlan_dev->name, vlan_id);
+                               break;
+                       }
+               }
+
+               if (vlan_id) {
+                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
+                                     vlan->vlan_ip, vlan_id);
+                       continue;
+               }
+
+               if (net_ratelimit()) {
+                       printk(KERN_WARNING DRV_NAME
+              ": %s: no path to arp_ip_target %u.%u.%u.%u via rt.dev %s\n",
+                              bond->dev->name, NIPQUAD(fl.fl4_dst),
+                              rt->u.dst.dev ? rt->u.dst.dev->name : "NULL");
+               }
+       }
+}
+
+/*
+ * Kick out a gratuitous ARP for an IP on the bonding master plus one
+ * for each VLAN above us.
+ */
+static void bond_send_gratuitous_arp(struct bonding *bond)
+{
+       struct slave *slave = bond->curr_active_slave;
+       struct vlan_entry *vlan;
+       struct net_device *vlan_dev;
+
+       dprintk("bond_send_grat_arp: bond %s slave %s\n", bond->dev->name,
+                               slave ? slave->dev->name : "NULL");
+       if (!slave)
+               return;
+
+       if (bond->master_ip) {
+               bond_arp_send(slave->dev, ARPOP_REPLY, bond->master_ip,
+                                 bond->master_ip, 0);
+       }
+
+       list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
+               vlan_dev = bond->vlgrp->vlan_devices[vlan->vlan_id];
+               if (vlan->vlan_ip) {
+                       bond_arp_send(slave->dev, ARPOP_REPLY, vlan->vlan_ip,
+                                     vlan->vlan_ip, vlan->vlan_id);
+               }
        }
 }
 
@@ -2781,7 +2952,7 @@ static void bond_loadbalance_arp_mon(struct net_device *bond_dev)
                         */
                        if (((jiffies - slave->dev->trans_start) >= (2*delta_in_ticks)) ||
                            (((jiffies - slave->dev->last_rx) >= (2*delta_in_ticks)) &&
-                            my_ip)) {
+                            bond_has_ip(bond))) {
 
                                slave->link  = BOND_LINK_DOWN;
                                slave->state = BOND_STATE_BACKUP;
@@ -2920,7 +3091,7 @@ static void bond_activebackup_arp_mon(struct net_device *bond_dev)
                        if ((slave != bond->curr_active_slave) &&
                            (!bond->current_arp_slave) &&
                            (((jiffies - slave->dev->last_rx) >= 3*delta_in_ticks) &&
-                            my_ip)) {
+                            bond_has_ip(bond))) {
                                /* a backup slave has gone down; three times
                                 * the delta allows the current slave to be
                                 * taken out before the backup slave.
@@ -2966,8 +3137,8 @@ static void bond_activebackup_arp_mon(struct net_device *bond_dev)
                 * if it is up and needs to take over as the curr_active_slave
                 */
                if ((((jiffies - slave->dev->trans_start) >= (2*delta_in_ticks)) ||
-                    (((jiffies - slave->dev->last_rx) >= (2*delta_in_ticks)) &&
-                     my_ip)) &&
+           (((jiffies - slave->dev->last_rx) >= (2*delta_in_ticks)) &&
+            bond_has_ip(bond))) &&
                    ((jiffies - slave->jiffies) >= 2*delta_in_ticks)) {
 
                        slave->link  = BOND_LINK_DOWN;
@@ -3019,7 +3190,7 @@ static void bond_activebackup_arp_mon(struct net_device *bond_dev)
                /* the current slave must tx an arp to ensure backup slaves
                 * rx traffic
                 */
-               if (slave && my_ip) {
+               if (slave && bond_has_ip(bond)) {
                        bond_arp_send_all(bond, slave);
                }
        }
@@ -3471,10 +3642,67 @@ static int bond_netdev_event(struct notifier_block *this, unsigned long event, v
        return NOTIFY_DONE;
 }
 
+/*
+ * bond_inetaddr_event: handle inetaddr notifier chain events.
+ *
+ * We keep track of device IPs primarily to use as source addresses in
+ * ARP monitor probes (rather than spewing out broadcasts all the time).
+ *
+ * We track one IP for the main device (if it has one), plus one per VLAN.
+ */
+static int bond_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+       struct in_ifaddr *ifa = ptr;
+       struct net_device *vlan_dev, *event_dev = ifa->ifa_dev->dev;
+       struct bonding *bond, *bond_next;
+       struct vlan_entry *vlan, *vlan_next;
+
+       list_for_each_entry_safe(bond, bond_next, &bond_dev_list, bond_list) {
+               if (bond->dev == event_dev) {
+                       switch (event) {
+                       case NETDEV_UP:
+                               bond->master_ip = ifa->ifa_local;
+                               return NOTIFY_OK;
+                       case NETDEV_DOWN:
+                               bond->master_ip = bond_glean_dev_ip(bond->dev);
+                               return NOTIFY_OK;
+                       default:
+                               return NOTIFY_DONE;
+                       }
+               }
+
+               if (list_empty(&bond->vlan_list))
+                       continue;
+
+               list_for_each_entry_safe(vlan, vlan_next, &bond->vlan_list,
+                                        vlan_list) {
+                       vlan_dev = bond->vlgrp->vlan_devices[vlan->vlan_id];
+                       if (vlan_dev == event_dev) {
+                               switch (event) {
+                               case NETDEV_UP:
+                                       vlan->vlan_ip = ifa->ifa_local;
+                                       return NOTIFY_OK;
+                               case NETDEV_DOWN:
+                                       vlan->vlan_ip =
+                                               bond_glean_dev_ip(vlan_dev);
+                                       return NOTIFY_OK;
+                               default:
+                                       return NOTIFY_DONE;
+                               }
+                       }
+               }
+       }
+       return NOTIFY_DONE;
+}
+
 static struct notifier_block bond_netdev_notifier = {
        .notifier_call = bond_netdev_event,
 };
 
+static struct notifier_block bond_inetaddr_notifier = {
+       .notifier_call = bond_inetaddr_event,
+};
+
 /*-------------------------- Packet type handling ---------------------------*/
 
 /* register to receive lacpdus on a bond */
@@ -4060,17 +4288,6 @@ static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *bond_d
        struct bonding *bond = bond_dev->priv;
        int res = 1;
 
-       /* if we are sending arp packets, try to at least
-          identify our own ip address */
-       if (bond->params.arp_interval && !my_ip &&
-               (skb->protocol == __constant_htons(ETH_P_ARP))) {
-               char *the_ip = (char *)skb->data +
-                               sizeof(struct ethhdr) +
-                               sizeof(struct arphdr) +
-                               ETH_ALEN;
-               memcpy(&my_ip, the_ip, 4);
-       }
-
        read_lock(&bond->lock);
        read_lock(&bond->curr_slave_lock);
 
@@ -4669,6 +4886,7 @@ static int __init bonding_init(void)
 
        rtnl_unlock();
        register_netdevice_notifier(&bond_netdev_notifier);
+       register_inetaddr_notifier(&bond_inetaddr_notifier);
 
        return 0;
 
@@ -4684,6 +4902,7 @@ out_err:
 static void __exit bonding_exit(void)
 {
        unregister_netdevice_notifier(&bond_netdev_notifier);
+       unregister_inetaddr_notifier(&bond_inetaddr_notifier);
 
        rtnl_lock();
        bond_free_all();
index 8c32530..6558af2 100644 (file)
@@ -36,8 +36,8 @@
 #include "bond_3ad.h"
 #include "bond_alb.h"
 
-#define DRV_VERSION    "2.6.1"
-#define DRV_RELDATE    "October 29, 2004"
+#define DRV_VERSION    "2.6.2"
+#define DRV_RELDATE    "June 5, 2005"
 #define DRV_NAME       "bonding"
 #define DRV_DESCRIPTION        "Ethernet Channel Bonding Driver"
 
@@ -149,6 +149,7 @@ struct bond_params {
 
 struct vlan_entry {
        struct list_head vlan_list;
+       u32 vlan_ip;
        unsigned short vlan_id;
 };
 
@@ -197,6 +198,7 @@ struct bonding {
 #endif /* CONFIG_PROC_FS */
        struct   list_head bond_list;
        struct   dev_mc_list *mc_list;
+       u32      master_ip;
        u16      flags;
        struct   ad_bond_info ad_info;
        struct   alb_bond_info alb_info;