Re: bond interface arp, vlan and trunk / network question

[Jiri Pirko]

Thu, Apr 23, 2009 at 03:12:29AM CEST, fubar@xxxxxxxxxx wrote:
>stefan novak <lms.brubaker@xxxxxxxxx> wrote:
>
>>so its a bug in kernel?
>
>	Yes.  I think the following patch should add support for
>arp_validate over VLANs, could you test this?  This is still a work in
>progress, so it's pretty rough around the edges, but the core
>functionality should be there.
>
>	This works by moving the skb_bond_should_drop logic around, and
>replaces the current inline code with a hook into bonding to do all of
>that, plus additional logic.  The reason for a hook is to get the
>skb_bond_should_drop callers from the VLAN input path before the input
>device is assigned to the VLAN device.
>
>	-J
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 99610f3..cc367a3 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -1607,6 +1607,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
> 	read_lock(&bond->lock);
> 
> 	new_slave->last_arp_rx = jiffies;
>+	bond_fix_slave_validate_flag(bond, new_slave);
> 
> 	if (bond->params.miimon && !bond->params.use_carrier) {
> 		link_reporting = bond_check_dev_link(bond, slave_dev, 1);
>@@ -2538,8 +2539,8 @@ static void bond_arp_send(struct net_device *slave_dev, int arp_op, __be32 dest_
> {
> 	struct sk_buff *skb;
> 
>-	pr_debug("arp %d on slave %s: dst %x src %x vid %d\n", arp_op,
>-	       slave_dev->name, dest_ip, src_ip, vlan_id);
>+	pr_debug("arp %d on slave %s: dst %x src %x vid %d j %lu\n", arp_op,
>+		 slave_dev->name, dest_ip, src_ip, vlan_id, jiffies);
> 	       
> 	skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
> 			 NULL, slave_dev->dev_addr, NULL);
>@@ -2679,8 +2680,6 @@ static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32
> 
> 	targets = bond->params.arp_targets;
> 	for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
>-		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
>-			&sip, &tip, i, &targets[i], bond_has_this_ip(bond, tip));
> 		if (sip == targets[i]) {
> 			if (bond_has_this_ip(bond, tip))
> 				slave->last_arp_rx = jiffies;
>@@ -2689,35 +2688,36 @@ static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32
> 	}
> }
> 
>-static int bond_arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
>+static void bond_handle_arp(struct sk_buff *skb, struct net_device *dev)
> {
> 	struct arphdr *arp;
> 	struct slave *slave;
>+	struct net_device *bond_dev = dev->master;
> 	struct bonding *bond;
> 	unsigned char *arp_ptr;
> 	__be32 sip, tip;
> 
> 	if (dev_net(dev) != &init_net)
>-		goto out;
>+		return;
> 
>-	if (!(dev->priv_flags & IFF_BONDING) || !(dev->flags & IFF_MASTER))
>-		goto out;
>+	bond = netdev_priv(bond_dev);
> 
>-	bond = netdev_priv(dev);
> 	read_lock(&bond->lock);
> 
>-	pr_debug("bond_arp_rcv: bond %s skb->dev %s orig_dev %s\n",
>-		bond->dev->name, skb->dev ? skb->dev->name : "NULL",
>-		orig_dev ? orig_dev->name : "NULL");
>-
>-	slave = bond_get_slave_by_dev(bond, orig_dev);
>+	slave = bond_get_slave_by_dev(bond, dev);
> 	if (!slave || !slave_do_arp_validate(bond, slave))
> 		goto out_unlock;
> 
> 	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
> 		goto out_unlock;
> 
>-	arp = arp_hdr(skb);
>+	/* Can't use arp_hdr; it's not initialized yet. */
>+	arp = (struct arphdr *)skb->data;
>+
>+	pr_debug("arp: hln %d p_t %d hrd %x pro %x pln %d\n",
>+	       arp->ar_hln, skb->pkt_type, ntohs(arp->ar_hrd),
>+	       ntohs(arp->ar_pro), arp->ar_pln);
>+
> 	if (arp->ar_hln != dev->addr_len ||
> 	    skb->pkt_type == PACKET_OTHERHOST ||
> 	    skb->pkt_type == PACKET_LOOPBACK ||
>@@ -2732,29 +2732,67 @@ static int bond_arp_rcv(struct sk_buff *skb, struct net_device *dev, struct pack
> 	arp_ptr += 4 + dev->addr_len;
> 	memcpy(&tip, arp_ptr, 4);
> 
>-	pr_debug("bond_arp_rcv: %s %s/%d av %d sv %d sip %pI4 tip %pI4\n",
>-		bond->dev->name, slave->dev->name, slave->state,
>-		bond->params.arp_validate, slave_do_arp_validate(bond, slave),
>-		&sip, &tip);
>-
>-	/*
>-	 * Backup slaves won't see the ARP reply, but do come through
>-	 * here for each ARP probe (so we swap the sip/tip to validate
>-	 * the probe).  In a "redundant switch, common router" type of
>-	 * configuration, the ARP probe will (hopefully) travel from
>-	 * the active, through one switch, the router, then the other
>-	 * switch before reaching the backup.
>-	 */
>-	if (slave->state == BOND_STATE_ACTIVE)
>+	switch (ntohs(arp->ar_op)) {
>+	case ARPOP_REPLY:
> 		bond_validate_arp(bond, slave, sip, tip);
>-	else
>+		break;
>+	case ARPOP_REQUEST:
> 		bond_validate_arp(bond, slave, tip, sip);
>+		break;
>+	}
> 
> out_unlock:
> 	read_unlock(&bond->lock);
>-out:
>-	dev_kfree_skb(skb);
>-	return NET_RX_SUCCESS;
>+}
>+
>+/*
>+ * Called by core packet processing in netif_receive_skb and in VLAN fast
>+ * path to (a) determine if packet should be dropped, and (b) to perform
>+ * ARP monitor processing (last_rx, validation).
>+ *
>+ * For the VLAN case, called before the skb->dev is reassigned to the
>+ * VLAN.
>+ *
>+ * Returns 1 if frame should nominally be dropped; 0 if it should be kept.
>+ *
>+ * We want to keep:
>+ * - all traffic on active slaves
>+ * - some traffic on inactive slaves: non-broadcast and non-multicast in
>+ * ALB/TLB mode and LACP frames in 802.3ad mode.
>+ *
>+ * ARP frames are handled as normal traffic; the ARP monitor handling
>+ * takes place here, so they need not be kept on inactive slaves.
>+ */
>+static int bond_handle_frame(struct sk_buff *skb)
>+{
>+	struct net_device *dev;
>+	struct net_device *master;
>+
>+	dev = skb->dev;
>+	master = dev->master;
>+	if (!master || !master->priv_flags & IFF_BONDING)
>+		return 0;
>+
>+	if (master->priv_flags & IFF_MASTER_ARPMON) {
>+		dev->last_rx = jiffies;
>+		if ((dev->priv_flags & IFF_SLAVE_NEEDARP) &&
>+		    skb->protocol == __constant_htons(ETH_P_ARP))
>+			bond_handle_arp(skb, dev);
>+	}
>+
>+	if (dev->priv_flags & IFF_SLAVE_INACTIVE) {
>+		if (master->priv_flags & IFF_MASTER_ALB) {
>+			if (skb->pkt_type != PACKET_BROADCAST &&
>+			    skb->pkt_type != PACKET_MULTICAST)
>+				return 0;
>+		}
>+		if (master->priv_flags & IFF_MASTER_8023AD &&
>+		    skb->protocol == __constant_htons(ETH_P_SLOW))
>+			return 0;
>+
>+		return 1;
>+	}
>+	return 0;
> }
> 
> /*
>@@ -3688,6 +3726,7 @@ static void bond_unregister_lacpdu(struct bonding *bond)
> 
> void bond_register_arp(struct bonding *bond)
> {
>+#if 0
> 	struct packet_type *pt = &bond->arp_mon_pt;
> 
> 	if (pt->type)
>@@ -3697,14 +3736,17 @@ void bond_register_arp(struct bonding *bond)
> 	pt->dev = bond->dev;
> 	pt->func = bond_arp_rcv;
> 	dev_add_pack(pt);
>+#endif
> }
> 
> void bond_unregister_arp(struct bonding *bond)
> {
>+#if 0
> 	struct packet_type *pt = &bond->arp_mon_pt;
> 
> 	dev_remove_pack(pt);
> 	pt->type = 0;
>+#endif
> }
> 
> /*---------------------------- Hashing Policies -----------------------------*/
>@@ -5188,6 +5230,8 @@ out_rtnl:
> 	return res;
> }
> 
>+extern int (*bond_handle_frame_hook)(struct sk_buff *skb);
>+
> static int __init bonding_init(void)
> {
> 	int i;
>@@ -5221,6 +5265,8 @@ static int __init bonding_init(void)
> 	register_inetaddr_notifier(&bond_inetaddr_notifier);
> 	bond_register_ipv6_notifier();
> 
>+	bond_handle_frame_hook = bond_handle_frame;
>+
> 	goto out;
> err:
> 	list_for_each_entry(bond, &bond_dev_list, bond_list) {
>@@ -5249,6 +5295,9 @@ static void __exit bonding_exit(void)
> 	rtnl_lock();
> 	bond_free_all();
> 	rtnl_unlock();
>+
>+	bond_handle_frame_hook = NULL;
>+
> }
> 
> module_init(bonding_init);
>diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
>index 18cf478..0e9f0e9 100644
>--- a/drivers/net/bonding/bond_sysfs.c
>+++ b/drivers/net/bonding/bond_sysfs.c
>@@ -484,8 +484,9 @@ static ssize_t bonding_store_arp_validate(struct device *d,
> 					  struct device_attribute *attr,
> 					  const char *buf, size_t count)
> {
>-	int new_value;
>+	int new_value, i;
> 	struct bonding *bond = to_bond(d);
>+	struct slave *slave;
> 
> 	new_value = bond_parse_parm(buf, arp_validate_tbl);
> 	if (new_value < 0) {
>@@ -504,13 +505,12 @@ static ssize_t bonding_store_arp_validate(struct device *d,
> 	       bond->dev->name, arp_validate_tbl[new_value].modename,
> 	       new_value);
> 
>-	if (!bond->params.arp_validate && new_value) {
>-		bond_register_arp(bond);
>-	} else if (bond->params.arp_validate && !new_value) {
>-		bond_unregister_arp(bond);
>-	}
>+	if (bond->params.arp_validate != new_value) {
>+		bond->params.arp_validate = new_value;
> 
>-	bond->params.arp_validate = new_value;
>+		bond_for_each_slave(bond, slave, i)
>+			bond_fix_slave_validate_flag(bond, slave);
>+	}
> 
> 	return count;
> }
>diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
>index ca849d2..275f08d 100644
>--- a/drivers/net/bonding/bonding.h
>+++ b/drivers/net/bonding/bonding.h
>@@ -283,6 +283,15 @@ static inline unsigned long slave_last_rx(struct bonding *bond,
> 	return slave->dev->last_rx;
> }
> 
>+static inline void bond_fix_slave_validate_flag(struct bonding *bond,
>+					       struct slave *slave)
>+{
>+	if (slave_do_arp_validate(bond, slave))
>+		slave->dev->priv_flags |= IFF_SLAVE_NEEDARP;
>+	else
>+		slave->dev->priv_flags &= ~IFF_SLAVE_NEEDARP;
>+}
>+
> static inline void bond_set_slave_inactive_flags(struct slave *slave)
> {
> 	struct bonding *bond = netdev_priv(slave->dev->master);
>@@ -290,14 +299,16 @@ static inline void bond_set_slave_inactive_flags(struct slave *slave)
> 	    bond->params.mode != BOND_MODE_ALB)
> 		slave->state = BOND_STATE_BACKUP;
> 	slave->dev->priv_flags |= IFF_SLAVE_INACTIVE;
>-	if (slave_do_arp_validate(bond, slave))
>-		slave->dev->priv_flags |= IFF_SLAVE_NEEDARP;
>+	bond_fix_slave_validate_flag(bond, slave);
> }
> 
> static inline void bond_set_slave_active_flags(struct slave *slave)
> {
>+	struct bonding *bond = netdev_priv(slave->dev->master);
>+
> 	slave->state = BOND_STATE_ACTIVE;
>-	slave->dev->priv_flags &= ~(IFF_SLAVE_INACTIVE | IFF_SLAVE_NEEDARP);
>+	slave->dev->priv_flags &= ~IFF_SLAVE_INACTIVE;
>+	bond_fix_slave_validate_flag(bond, slave);
> }
> 
> static inline void bond_set_master_3ad_flags(struct bonding *bond)
>diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>index 2e7783f..3dafd8f 100644
>--- a/include/linux/netdevice.h
>+++ b/include/linux/netdevice.h
>@@ -1874,6 +1874,7 @@ static inline void netif_set_gso_max_size(struct net_device *dev,
> 	dev->gso_max_size = size;
> }
> 
>+#if 0
> /* On bonding slaves other than the currently active slave, suppress
>  * duplicates except for 802.3ad ETH_P_SLOW, alb non-mcast/bcast, and
>  * ARP on active-backup slaves with arp_validate enabled.
>@@ -1906,6 +1907,8 @@ static inline int skb_bond_should_drop(struct sk_buff *skb)
> 	}
> 	return 0;
> }
>+#endif
>+extern int skb_bond_should_drop(struct sk_buff *skb);
> 
> extern struct pernet_operations __net_initdata loopback_net_ops;
> #endif /* __KERNEL__ */
>diff --git a/net/core/dev.c b/net/core/dev.c
>index 91d792d..ac5a37e 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -2098,6 +2098,56 @@ static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
> #define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)
> #endif
> 
>+#if defined(CONFIG_BONDING) || defined(CONFIG_BONDING_MODULE)
>+int (*bond_handle_frame_hook)(struct sk_buff *skb);
>+EXPORT_SYMBOL_GPL(bond_handle_frame_hook);
>+
>+/* On bonding slaves other than the currently active slave, suppress
>+ * duplicates except for 802.3ad ETH_P_SLOW, alb non-mcast/bcast, and
>+ * ARP on active-backup slaves with arp_validate enabled.
>+ */
>+int skb_bond_should_drop(struct sk_buff *skb)
>+{
>+	struct net_device *dev = skb->dev;
>+	struct net_device *master = dev->master;
>+
>+	if (master)
>+		return bond_handle_frame_hook(skb);

Maybe this hook can be called from netif_receive_skb() directly. You would safe
at least 2 dereferences, 1 if check. You would also need to add
"skb->dev->master &&" to if in __vlan_hwaccel_rx() and vlan_gro_common().
>+
>+	return 0;
>+
>+#if 0
>+		if (master->priv_flags & IFF_MASTER_ARPMON)
>+			dev->last_rx = jiffies;
>+
>+		if (dev->priv_flags & IFF_SLAVE_INACTIVE) {
>+			if ((dev->priv_flags & IFF_SLAVE_NEEDARP) &&
>+			    skb->protocol == __constant_htons(ETH_P_ARP))
>+				return 0;
>+
>+			if (master->priv_flags & IFF_MASTER_ALB) {
>+				if (skb->pkt_type != PACKET_BROADCAST &&
>+				    skb->pkt_type != PACKET_MULTICAST)
>+					return 0;
>+			}
>+			if (master->priv_flags & IFF_MASTER_8023AD &&
>+			    skb->protocol == __constant_htons(ETH_P_SLOW))
>+				return 0;
>+
>+			return 1;
>+		}
>+	}
>+	return 0;
>+#endif /* 0 */
>+}
>+#else
>+int skb_bond_should_drop(struct sk_buff *skb)
>+{
>+	return 0;
>+}
>+#endif
>+EXPORT_SYMBOL_GPL(skb_bond_should_drop);
>+
> #ifdef CONFIG_NET_CLS_ACT
> /* TODO: Maybe we should just force sch_ingress to be compiled in
>  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
>
>
>---
>	-Jay Vosburgh, IBM Linux Technology Center, fubar@xxxxxxxxxx
>--
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