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

From: Jiri Pirko
Date: Thu Apr 23 2009 - 04:06:11 EST


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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