From c3ade5cad07f4d67f2e16a28f3c73d9483a55e0e Mon Sep 17 00:00:00 2001 From: Jay Vosburgh Date: Sun, 26 Jun 2005 17:52:20 -0400 Subject: bonding: gratuitous ARP 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 --- drivers/net/bonding/bond_main.c | 283 +++++++++++++++++++++++++++++++++++----- 1 file changed, 251 insertions(+), 32 deletions(-) (limited to 'drivers/net/bonding/bond_main.c') diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 269a5e4..545f6fe 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -475,7 +475,10 @@ * Solution is to move call to dev_remove_pack outside of the * spinlock. * Set version to 2.6.1. - * + * 2005/06/05 - Jay Vosburgh + * - 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 @@ -519,6 +522,7 @@ #include #include #include +#include #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(); -- cgit v1.1