[PATCH draft] bonding: add IPv6 NS/NA monitor support

From: Hangbin Liu <liuhangbin@gmail.com>
To: netdev@vger.kernel.org
Cc: Jay Vosburgh <j.vosburgh@gmail.com>,
	Veaceslav Falico <vfalico@gmail.com>,
	Andy Gospodarek <andy@greyhouse.net>,
	Jarod Wilson <jarod@redhat.com>, Jakub Kicinski <kuba@kernel.org>,
	Jiri Pirko <jiri@resnulli.us>,
	davem@davemloft.net, Denis Kirjanov <dkirjanov@suse.de>,
	David Ahern <dsahern@gmail.com>,
	Hangbin Liu <liuhangbin@gmail.com>
Subject: [PATCH draft] bonding: add IPv6 NS/NA monitor support
Date: Wed, 24 Nov 2021 15:18:53 +0800	[thread overview]
Message-ID: <20211124071854.1400032-1-liuhangbin@gmail.com> (raw)

This patch add bond IPv6 NS/NA monitor support. A new option
ns_ip6_target is added, which is similar with arp_ip_target.
The IPv6 NS/NA monitor will take effect when there is a valid IPv6
address. And ARP monitor will stop working.

A new field struct in6_addr ip6_addr is added to struct bond_opt_value
for IPv6 support. Thus __bond_opt_init() is also updated to check
string, addr first.

Function bond_handle_vlan() is split from bond_arp_send() for both
IPv4/IPv6 usage.

To alloc NS message and send out. ndisc_ns_create() and ndisc_send_skb()
are exported.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 Documentation/networking/bonding.rst |  11 ++
 drivers/net/bonding/bond_main.c      | 260 ++++++++++++++++++++++++---
 drivers/net/bonding/bond_netlink.c   |  48 +++++
 drivers/net/bonding/bond_options.c   | 142 ++++++++++++++-
 drivers/net/bonding/bond_sysfs.c     |  22 +++
 include/net/bond_options.h           |  14 +-
 include/net/bonding.h                |  36 ++++
 include/net/ndisc.h                  |   9 +
 include/uapi/linux/if_link.h         |   1 +
 net/ipv6/ndisc.c                     |  48 +++--
 tools/include/uapi/linux/if_link.h   |   1 +
 11 files changed, 544 insertions(+), 48 deletions(-)

diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst
index dc28c9551b9b..ff4560c4feae 100644
--- a/Documentation/networking/bonding.rst
+++ b/Documentation/networking/bonding.rst
@@ -312,6 +312,17 @@ arp_ip_target
 	maximum number of targets that can be specified is 16.  The
 	default value is no IP addresses.
 
+ns_ip6_target
+
+	Specifies the IPv6 addresses to use as IPv6 monitoring peers when
+	arp_interval is > 0.  These are the targets of the NS request
+	sent to determine the health of the link to the targets.
+	Specify these values in ffff:ffff::ffff:ffff format.  Multiple IPv6
+	addresses must be separated by a comma.  At least one IPv6
+	address must be given for NS/NA monitoring to function.  The
+	maximum number of targets that can be specified is 16.  The
+	default value is no IPv6 addresses.
+
 arp_validate
 
 	Specifies whether or not ARP probes and replies should be
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 9a28d3de798e..9f87f2abdc22 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -86,6 +86,7 @@
 #if IS_ENABLED(CONFIG_TLS_DEVICE)
 #include <net/tls.h>
 #endif
+#include <net/ip6_route.h>
 
 #include "bonding_priv.h"
 
@@ -2792,31 +2793,41 @@ static bool bond_has_this_ip(struct bonding *bond, __be32 ip)
 	return ret;
 }
 
-/* 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 slave *slave, int arp_op, __be32 dest_ip,
-			  __be32 src_ip, struct bond_vlan_tag *tags)
+static int bond_confirm_addr6(struct net_device *dev,
+			       struct netdev_nested_priv *priv)
 {
-	struct sk_buff *skb;
-	struct bond_vlan_tag *outer_tag = tags;
-	struct net_device *slave_dev = slave->dev;
-	struct net_device *bond_dev = slave->bond->dev;
+	struct in6_addr *addr = (struct in6_addr *)priv->data;
 
-	slave_dbg(bond_dev, slave_dev, "arp %d on slave: dst %pI4 src %pI4\n",
-		  arp_op, &dest_ip, &src_ip);
+	return ipv6_chk_addr(dev_net(dev), addr, dev, 0);
+}
 
-	skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
-			 NULL, slave_dev->dev_addr, NULL);
+static bool bond_has_this_ip6(struct bonding *bond, struct in6_addr *addr)
+{
+	struct netdev_nested_priv priv = {
+		.data = addr,
+	};
+	int ret = false;
 
-	if (!skb) {
-		net_err_ratelimited("ARP packet allocation failed\n");
-		return;
-	}
+	if (bond_confirm_addr6(bond->dev, &priv))
+		return true;
+
+	rcu_read_lock();
+	if (netdev_walk_all_upper_dev_rcu(bond->dev, bond_confirm_addr6, &priv))
+		ret = true;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static bool bond_handle_vlan(struct slave *slave, struct bond_vlan_tag *tags,
+			    struct sk_buff *skb)
+{
+	struct net_device *bond_dev = slave->bond->dev;
+	struct net_device *slave_dev = slave->dev;
+	struct bond_vlan_tag *outer_tag = tags;
 
 	if (!tags || tags->vlan_proto == VLAN_N_VID)
-		goto xmit;
+		return true;
 
 	tags++;
 
@@ -2833,7 +2844,7 @@ static void bond_arp_send(struct slave *slave, int arp_op, __be32 dest_ip,
 						tags->vlan_id);
 		if (!skb) {
 			net_err_ratelimited("failed to insert inner VLAN tag\n");
-			return;
+			return false;
 		}
 
 		tags++;
@@ -2846,10 +2857,57 @@ static void bond_arp_send(struct slave *slave, int arp_op, __be32 dest_ip,
 				       outer_tag->vlan_id);
 	}
 
-xmit:
-	arp_xmit(skb);
+	return true;
+}
+/* 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 slave *slave, int arp_op, __be32 dest_ip,
+			  __be32 src_ip, struct bond_vlan_tag *tags)
+{
+	struct sk_buff *skb;
+	struct net_device *slave_dev = slave->dev;
+	struct net_device *bond_dev = slave->bond->dev;
+
+	slave_dbg(bond_dev, slave_dev, "arp %d on slave: dst %pI4 src %pI4\n",
+		  arp_op, &dest_ip, &src_ip);
+
+	skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
+			 NULL, slave_dev->dev_addr, NULL);
+
+	if (!skb) {
+		net_err_ratelimited("ARP packet allocation failed\n");
+		return;
+	}
+
+	if (bond_handle_vlan(slave, tags, skb))
+		arp_xmit(skb);
+	return;
 }
 
+static void bond_ns_send(struct slave *slave, const struct in6_addr *daddr,
+			 const struct in6_addr *saddr, struct bond_vlan_tag *tags)
+{
+	struct sk_buff *skb;
+	struct net_device *slave_dev = slave->dev;
+	struct net_device *bond_dev = slave->bond->dev;
+	struct in6_addr mcaddr;
+
+	slave_dbg(bond_dev, slave_dev, "NS on slave: dst %pI6 src %pI6\n",
+		  &daddr, &saddr);
+
+	skb = ndisc_ns_create(slave_dev, daddr, saddr, 0);
+	if (!skb) {
+		net_err_ratelimited("NS packet allocation failed\n");
+		return;
+	}
+
+	addrconf_addr_solict_mult(daddr, &mcaddr);
+	if (bond_handle_vlan(slave, tags, skb))
+		ndisc_send_skb(skb, &mcaddr, saddr);
+	return;
+}
 /* Validate the device path between the @start_dev and the @end_dev.
  * The path is valid if the @end_dev is reachable through device
  * stacking.
@@ -3058,6 +3116,140 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
 	return RX_HANDLER_ANOTHER;
 }
 
+static void bond_ns_send_all(struct bonding *bond, struct slave *slave)
+{
+	struct in6_addr *targets = bond->params.ns_targets;
+	struct bond_vlan_tag *tags;
+	struct in6_addr saddr;
+	struct dst_entry *dst;
+	struct flowi6 fl6;
+	int i;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS && !ipv6_addr_any(&targets[i]); i++) {
+		slave_dbg(bond->dev, slave->dev, "%s: target %pI6\n",
+			  __func__, &targets[i]);
+		tags = NULL;
+
+		/* Find out through which dev should the packet go */
+		memset(&fl6, 0, sizeof(struct flowi6));
+		fl6.daddr = targets[i];
+		fl6.flowi6_oif = bond->dev->ifindex;
+
+		dst = ip6_route_output(dev_net(bond->dev), NULL, &fl6);
+		if (dst->error) {
+			dst_release(dst);
+			/* there's no route to target - try to send arp
+			 * probe to generate any traffic (arp_validate=0)
+			 */
+			if (bond->params.arp_validate)
+				pr_warn_once("%s: no route to ns_ip6_target %pI6 and arp_validate is set\n",
+					     bond->dev->name,
+					     &targets[i]);
+			bond_ns_send(slave, &targets[i], &in6addr_any, tags);
+			continue;
+		}
+
+		/* bond device itself */
+		if (dst->dev == bond->dev)
+			goto found;
+
+		rcu_read_lock();
+		tags = bond_verify_device_path(bond->dev, dst->dev, 0);
+		rcu_read_unlock();
+
+		if (!IS_ERR_OR_NULL(tags))
+			goto found;
+
+		/* Not our device - skip */
+		slave_dbg(bond->dev, slave->dev, "no path to ns_ip6_target %pI6 via dst->dev %s\n",
+			   &targets[i], dst->dev ? dst->dev->name : "NULL");
+
+		dst_release(dst);
+		continue;
+
+found:
+		if (!ipv6_dev_get_saddr(dev_net(dst->dev), dst->dev, &targets[i], 0, &saddr))
+			bond_ns_send(slave, &targets[i], &saddr, tags);
+		dst_release(dst);
+		kfree(tags);
+	}
+}
+
+static void bond_validate_ns(struct bonding *bond, struct slave *slave,
+			     struct in6_addr *saddr, struct in6_addr *daddr)
+{
+	int i;
+
+	if (ipv6_addr_any(saddr) || !bond_has_this_ip6(bond, daddr)) {
+		slave_dbg(bond->dev, slave->dev, "%s: sip %pI6 tip %pI6 not found\n",
+			   __func__, saddr, daddr);
+		return;
+	}
+
+	i = bond_get_targets_ip6(bond->params.ns_targets, saddr);
+	if (i == -1) {
+		slave_dbg(bond->dev, slave->dev, "%s: sip %pI6 not found in targets\n",
+			   __func__, saddr);
+		return;
+	}
+	slave->last_rx = jiffies;
+	slave->target_last_arp_rx[i] = jiffies;
+}
+
+int bond_na_rcv(const struct sk_buff *skb, struct bonding *bond,
+		 struct slave *slave)
+{
+	struct icmp6hdr *hdr = icmp6_hdr(skb);
+	struct slave *curr_active_slave, *curr_arp_slave;
+	struct in6_addr *saddr, *daddr;
+	bool is_icmpv6 = skb->protocol == __cpu_to_be16(ETH_P_IPV6);
+
+	if (!slave_do_arp_validate(bond, slave)) {
+		if ((slave_do_arp_validate_only(bond) && is_icmpv6) ||
+		    !slave_do_arp_validate_only(bond))
+			slave->last_rx = jiffies;
+		return RX_HANDLER_ANOTHER;
+	} else if (!is_icmpv6) {
+		return RX_HANDLER_ANOTHER;
+	}
+
+	slave_dbg(bond->dev, slave->dev, "%s: skb->dev %s\n",
+		   __func__, skb->dev->name);
+
+	if (skb->pkt_type == PACKET_OTHERHOST ||
+	    skb->pkt_type == PACKET_LOOPBACK ||
+	    hdr->icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT)
+		goto out;
+
+	saddr = &ipv6_hdr(skb)->saddr;
+	daddr = &ipv6_hdr(skb)->daddr;
+
+	slave_dbg(bond->dev, slave->dev, "%s: %s/%d av %d sv %d sip %pI6 tip %pI6\n",
+		  __func__, slave->dev->name, bond_slave_state(slave),
+		  bond->params.arp_validate, slave_do_arp_validate(bond, slave),
+		  saddr, daddr);
+
+	curr_active_slave = rcu_dereference(bond->curr_active_slave);
+	curr_arp_slave = rcu_dereference(bond->current_arp_slave);
+
+	/* We 'trust' the received ARP enough to validate it if:
+	 * see bond_arp_rcv().
+	 */
+	if (bond_is_active_slave(slave))
+		bond_validate_ns(bond, slave, saddr, daddr);
+	else if (curr_active_slave &&
+		 time_after(slave_last_rx(bond, curr_active_slave),
+			    curr_active_slave->last_link_up))
+		bond_validate_ns(bond, slave, saddr, daddr);
+	else if (curr_arp_slave &&
+		 bond_time_in_interval(bond,
+				       dev_trans_start(curr_arp_slave->dev), 1))
+		bond_validate_ns(bond, slave, saddr, daddr);
+
+out:
+	return RX_HANDLER_ANOTHER;
+}
+
 /* function to verify if we're in the arp_interval timeslice, returns true if
  * (last_act - arp_interval) <= jiffies <= (last_act + mod * arp_interval +
  * arp_interval/2) . the arp_interval/2 is needed for really fast networks.
@@ -3152,8 +3344,12 @@ static void bond_loadbalance_arp_mon(struct bonding *bond)
 		 * do - all replies will be rx'ed on same link causing slaves
 		 * to be unstable during low/no traffic periods
 		 */
-		if (bond_slave_is_up(slave))
-			bond_arp_send_all(bond, slave);
+		if (bond_slave_is_up(slave)) {
+			if (bond_do_ns_validate(bond))
+				bond_ns_send_all(bond, slave);
+			else
+				bond_arp_send_all(bond, slave);
+		}
 	}
 
 	rcu_read_unlock();
@@ -3367,7 +3563,10 @@ static bool bond_ab_arp_probe(struct bonding *bond)
 			    curr_active_slave->dev->name);
 
 	if (curr_active_slave) {
-		bond_arp_send_all(bond, curr_active_slave);
+		if (bond_do_ns_validate(bond))
+			bond_ns_send_all(bond, curr_active_slave);
+		else
+			bond_arp_send_all(bond, curr_active_slave);
 		return should_notify_rtnl;
 	}
 
@@ -3419,7 +3618,10 @@ static bool bond_ab_arp_probe(struct bonding *bond)
 	bond_set_slave_link_state(new_slave, BOND_LINK_BACK,
 				  BOND_SLAVE_NOTIFY_LATER);
 	bond_set_slave_active_flags(new_slave, BOND_SLAVE_NOTIFY_LATER);
-	bond_arp_send_all(bond, new_slave);
+	if (bond_do_ns_validate(bond))
+		bond_ns_send_all(bond, new_slave);
+	else
+		bond_arp_send_all(bond, new_slave);
 	new_slave->last_link_up = jiffies;
 	rcu_assign_pointer(bond->current_arp_slave, new_slave);
 
@@ -3955,7 +4157,10 @@ static int bond_open(struct net_device *bond_dev)
 
 	if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
 		queue_delayed_work(bond->wq, &bond->arp_work, 0);
-		bond->recv_probe = bond_arp_rcv;
+		if (bond_do_ns_validate(bond))
+			bond->recv_probe = bond_na_rcv;
+		else
+			bond->recv_probe = bond_arp_rcv;
 	}
 
 	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
@@ -5857,6 +6062,7 @@ static int bond_check_params(struct bond_params *params)
 		strscpy_pad(params->primary, primary, sizeof(params->primary));
 
 	memcpy(params->arp_targets, arp_target, sizeof(arp_target));
+	memset(params->ns_targets, 0, sizeof(struct in6_addr) * BOND_MAX_ARP_TARGETS);
 
 	return 0;
 }
diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 1007bf6d385d..0d4e0a3b7c4f 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -14,6 +14,7 @@
 #include <net/netlink.h>
 #include <net/rtnetlink.h>
 #include <net/bonding.h>
+#include <net/ipv6.h>
 
 static size_t bond_get_slave_size(const struct net_device *bond_dev,
 				  const struct net_device *slave_dev)
@@ -111,6 +112,7 @@ static const struct nla_policy bond_policy[IFLA_BOND_MAX + 1] = {
 	[IFLA_BOND_TLB_DYNAMIC_LB]	= { .type = NLA_U8 },
 	[IFLA_BOND_PEER_NOTIF_DELAY]    = { .type = NLA_U32 },
 	[IFLA_BOND_MISSED_MAX]		= { .type = NLA_U8 },
+	[IFLA_BOND_NS_IP6_TARGET]	= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy bond_slave_policy[IFLA_BOND_SLAVE_MAX + 1] = {
@@ -272,6 +274,31 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 		if (err)
 			return err;
 	}
+	if (data[IFLA_BOND_NS_IP6_TARGET]) {
+		struct nlattr *attr;
+		int i = 0, rem;
+
+		bond_option_ns_ip6_targets_clear(bond);
+		nla_for_each_nested(attr, data[IFLA_BOND_NS_IP6_TARGET], rem) {
+			struct in6_addr target;
+
+			if (nla_len(attr) < sizeof(target))
+				return -EINVAL;
+
+			target = nla_get_in6_addr(attr);
+
+			bond_opt_initaddr(&newval, &target);
+			err = __bond_opt_set(bond, BOND_OPT_NS_TARGETS,
+					     &newval);
+			if (err)
+				break;
+			i++;
+		}
+		if (i == 0 && bond->params.arp_interval)
+			netdev_warn(bond->dev, "Removing last ns target with arp_interval on\n");
+		if (err)
+			return err;
+	}
 	if (data[IFLA_BOND_ARP_VALIDATE]) {
 		int arp_validate = nla_get_u32(data[IFLA_BOND_ARP_VALIDATE]);
 
@@ -526,6 +553,9 @@ static size_t bond_get_size(const struct net_device *bond_dev)
 		nla_total_size(sizeof(u8)) + /* IFLA_BOND_TLB_DYNAMIC_LB */
 		nla_total_size(sizeof(u32)) +	/* IFLA_BOND_PEER_NOTIF_DELAY */
 		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_MISSED_MAX */
+						/* IFLA_BOND_NS_IP6_TARGET */
+		nla_total_size(sizeof(struct nlattr)) +
+		nla_total_size(sizeof(struct in6_addr)) * BOND_MAX_ARP_TARGETS +
 		0;
 }
 
@@ -603,6 +633,24 @@ static int bond_fill_info(struct sk_buff *skb,
 			bond->params.arp_all_targets))
 		goto nla_put_failure;
 
+	targets = nla_nest_start(skb, IFLA_BOND_NS_IP6_TARGET);
+	if (!targets)
+		goto nla_put_failure;
+
+	targets_added = 0;
+	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
+		if (!ipv6_addr_any(&bond->params.ns_targets[i])) {
+			if (nla_put_in6_addr(skb, i, &bond->params.ns_targets[i]))
+				goto nla_put_failure;
+			targets_added = 1;
+		}
+	}
+
+	if (targets_added)
+		nla_nest_end(skb, targets);
+	else
+		nla_nest_cancel(skb, targets);
+
 	primary = rtnl_dereference(bond->primary_slave);
 	if (primary &&
 	    nla_put_u32(skb, IFLA_BOND_PRIMARY, primary->dev->ifindex))
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 0f48921c4f15..d073d9c3ae9b 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -34,6 +34,12 @@ static int bond_option_arp_ip_target_add(struct bonding *bond, __be32 target);
 static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target);
 static int bond_option_arp_ip_targets_set(struct bonding *bond,
 					  const struct bond_opt_value *newval);
+static int bond_option_ns_ip6_target_add(struct bonding *bond,
+					 struct in6_addr *target);
+static int bond_option_ns_ip6_target_rem(struct bonding *bond,
+					 struct in6_addr *target);
+static int bond_option_ns_ip6_targets_set(struct bonding *bond,
+					  const struct bond_opt_value *newval);
 static int bond_option_arp_validate_set(struct bonding *bond,
 					const struct bond_opt_value *newval);
 static int bond_option_arp_all_targets_set(struct bonding *bond,
@@ -295,6 +301,13 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = {
 		.flags = BOND_OPTFLAG_RAWVAL,
 		.set = bond_option_arp_ip_targets_set
 	},
+	[BOND_OPT_NS_TARGETS] = {
+		.id = BOND_OPT_NS_TARGETS,
+		.name = "ns_ip6_target",
+		.desc = "NS targets in ffff:ffff::ffff:ffff form",
+		.flags = BOND_OPTFLAG_RAWVAL,
+		.set = bond_option_ns_ip6_targets_set
+	},
 	[BOND_OPT_DOWNDELAY] = {
 		.id = BOND_OPT_DOWNDELAY,
 		.name = "downdelay",
@@ -1052,7 +1065,10 @@ static int bond_option_arp_interval_set(struct bonding *bond,
 			cancel_delayed_work_sync(&bond->arp_work);
 		} else {
 			/* arp_validate can be set only in active-backup mode */
-			bond->recv_probe = bond_arp_rcv;
+			if (bond_do_ns_validate(bond))
+				bond->recv_probe = bond_na_rcv;
+			else
+				bond->recv_probe = bond_arp_rcv;
 			cancel_delayed_work_sync(&bond->mii_work);
 			queue_delayed_work(bond->wq, &bond->arp_work, 0);
 		}
@@ -1184,6 +1200,130 @@ static int bond_option_arp_ip_targets_set(struct bonding *bond,
 	return ret;
 }
 
+static void _bond_options_ns_ip6_target_set(struct bonding *bond, int slot,
+					    struct in6_addr *target,
+					    unsigned long last_rx)
+{
+	struct in6_addr *targets = bond->params.ns_targets;
+	struct list_head *iter;
+	struct slave *slave;
+
+	if (slot >= 0 && slot < BOND_MAX_ARP_TARGETS) {
+		bond_for_each_slave(bond, slave, iter)
+			slave->target_last_arp_rx[slot] = last_rx;
+		targets[slot] = *target;
+	}
+
+	/* Use IPv6 NS/NA monitor if NS target set */
+	if (bond_do_ns_validate(bond))
+		bond->recv_probe = bond_na_rcv;
+}
+
+void bond_option_ns_ip6_targets_clear(struct bonding *bond)
+{
+	struct in6_addr addr_any = in6addr_any;
+	int i;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
+		_bond_options_ns_ip6_target_set(bond, i, &addr_any, 0);
+}
+
+static int bond_option_ns_ip6_target_add(struct bonding *bond, struct in6_addr *target)
+{
+	struct in6_addr *targets = bond->params.ns_targets;
+	struct in6_addr addr_any = in6addr_any;
+	int index;
+
+	if (!bond_is_ip6_target_ok(target)) {
+		netdev_err(bond->dev, "invalid NS target %pI6 specified for addition\n",
+			   target);
+		return -EINVAL;
+	}
+
+	if (bond_get_targets_ip6(targets, target) != -1) { /* dup */
+		netdev_err(bond->dev, "NS target %pI6 is already present\n",
+			   &target);
+		return -EINVAL;
+	}
+
+	index = bond_get_targets_ip6(targets, &addr_any); /* first free slot */
+	if (index == -1) {
+		netdev_err(bond->dev, "NS target table is full!\n");
+		return -EINVAL;
+	}
+
+	netdev_dbg(bond->dev, "Adding NS target %pI6\n", &target);
+
+	_bond_options_ns_ip6_target_set(bond, index, target, jiffies);
+
+	return 0;
+}
+
+static int bond_option_ns_ip6_target_rem(struct bonding *bond, struct in6_addr *target)
+{
+	struct in6_addr *targets = bond->params.ns_targets;
+	struct list_head *iter;
+	struct slave *slave;
+	unsigned long *targets_rx;
+	int index, i;
+
+	if (!bond_is_ip6_target_ok(target)) {
+		netdev_err(bond->dev, "invalid NS target %pI6 specified for removal\n",
+			   target);
+		return -EINVAL;
+	}
+
+	index = bond_get_targets_ip6(targets, target);
+	if (index == -1) {
+		netdev_err(bond->dev, "unable to remove nonexistent NS target %pI6\n",
+			   target);
+		return -EINVAL;
+	}
+
+	if (index == 0 && ipv6_addr_any(&targets[1]) && bond->params.arp_interval)
+		netdev_warn(bond->dev, "Removing last NS target with arp_interval on\n");
+
+	netdev_dbg(bond->dev, "Removing NS target %pI6\n", target);
+
+	bond_for_each_slave(bond, slave, iter) {
+		targets_rx = slave->target_last_arp_rx;
+		for (i = index; (i < BOND_MAX_ARP_TARGETS-1) && !ipv6_addr_any(&targets[i+1]); i++)
+			targets_rx[i] = targets_rx[i+1];
+		targets_rx[i] = 0;
+	}
+	for (i = index; (i < BOND_MAX_ARP_TARGETS-1) && !ipv6_addr_any(&targets[i+1]); i++)
+		targets[i] = targets[i+1];
+	memset(&targets[i], 0, sizeof(struct in6_addr));
+
+	return 0;
+}
+
+static int bond_option_ns_ip6_targets_set(struct bonding *bond,
+					  const struct bond_opt_value *newval)
+{
+	int ret = -EPERM;
+	struct in6_addr target;
+
+	if (newval->string) {
+		if (!in6_pton(newval->string+1, -1, (u8 *)&target.s6_addr, -1, NULL)) {
+			netdev_err(bond->dev, "invalid NS target %pI6 specified\n",
+				   &target);
+			return ret;
+		}
+		if (newval->string[0] == '+')
+			ret = bond_option_ns_ip6_target_add(bond, &target);
+		else if (newval->string[0] == '-')
+			ret = bond_option_ns_ip6_target_rem(bond, &target);
+		else
+			netdev_err(bond->dev, "no command found in ns_ip6_targets file - use +<addr> or -<addr>\n");
+	} else {
+		target = newval->ip6_addr;
+		ret = bond_option_ns_ip6_target_add(bond, &target);
+	}
+
+	return ret;
+}
+
 static int bond_option_arp_validate_set(struct bonding *bond,
 					const struct bond_opt_value *newval)
 {
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 9b5a5df23d21..c61d95161782 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -25,6 +25,7 @@
 #include <linux/nsproxy.h>
 
 #include <net/bonding.h>
+#include <net/ipv6.h>
 
 #define to_bond(cd)	((struct bonding *)(netdev_priv(to_net_dev(cd))))
 
@@ -315,6 +316,26 @@ static ssize_t bonding_show_missed_max(struct device *d,
 static DEVICE_ATTR(arp_missed_max, 0644,
 		   bonding_show_missed_max, bonding_sysfs_store_option);
 
+static ssize_t bonding_show_ns_targets(struct device *d,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct bonding *bond = to_bond(d);
+	int i, res = 0;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
+		if (!ipv6_addr_any(&bond->params.ns_targets[i]))
+			res += sprintf(buf + res, "%pI6 ",
+				       &bond->params.ns_targets[i]);
+	}
+	if (res)
+		buf[res-1] = '\n'; /* eat the leftover space */
+
+	return res;
+}
+static DEVICE_ATTR(ns_ip6_target, 0644,
+		   bonding_show_ns_targets, bonding_sysfs_store_option);
+
 /* Show the up and down delays. */
 static ssize_t bonding_show_downdelay(struct device *d,
 				      struct device_attribute *attr,
@@ -761,6 +782,7 @@ static struct attribute *per_bond_attrs[] = {
 	&dev_attr_arp_all_targets.attr,
 	&dev_attr_arp_interval.attr,
 	&dev_attr_arp_ip_target.attr,
+	&dev_attr_ns_ip6_target.attr,
 	&dev_attr_downdelay.attr,
 	&dev_attr_updelay.attr,
 	&dev_attr_peer_notif_delay.attr,
diff --git a/include/net/bond_options.h b/include/net/bond_options.h
index dd75c071f67e..689cea946dbf 100644
--- a/include/net/bond_options.h
+++ b/include/net/bond_options.h
@@ -66,6 +66,7 @@ enum {
 	BOND_OPT_PEER_NOTIF_DELAY,
 	BOND_OPT_LACP_ACTIVE,
 	BOND_OPT_MISSED_MAX,
+	BOND_OPT_NS_TARGETS,
 	BOND_OPT_LAST
 };
 
@@ -79,6 +80,7 @@ struct bond_opt_value {
 	char *string;
 	u64 value;
 	u32 flags;
+	struct in6_addr ip6_addr;
 };
 
 struct bonding;
@@ -118,18 +120,22 @@ const struct bond_opt_value *bond_opt_get_val(unsigned int option, u64 val);
  * When value is ULLONG_MAX then string will be used.
  */
 static inline void __bond_opt_init(struct bond_opt_value *optval,
-				   char *string, u64 value)
+				   char *string, u64 value, struct in6_addr *addr)
 {
 	memset(optval, 0, sizeof(*optval));
 	optval->value = ULLONG_MAX;
-	if (value == ULLONG_MAX)
+	if (string)
 		optval->string = string;
+	else if (addr)
+		optval->ip6_addr = *addr;
 	else
 		optval->value = value;
 }
-#define bond_opt_initval(optval, value) __bond_opt_init(optval, NULL, value)
-#define bond_opt_initstr(optval, str) __bond_opt_init(optval, str, ULLONG_MAX)
+#define bond_opt_initval(optval, value) __bond_opt_init(optval, NULL, value, NULL)
+#define bond_opt_initstr(optval, str) __bond_opt_init(optval, str, ULLONG_MAX, NULL)
+#define bond_opt_initaddr(optval, addr) __bond_opt_init(optval, NULL, ULLONG_MAX, addr)
 
 void bond_option_arp_ip_targets_clear(struct bonding *bond);
+void bond_option_ns_ip6_targets_clear(struct bonding *bond);
 
 #endif /* _NET_BOND_OPTIONS_H */
diff --git a/include/net/bonding.h b/include/net/bonding.h
index f6ae3a4baea4..de1a38d1c531 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -29,6 +29,8 @@
 #include <net/bond_3ad.h>
 #include <net/bond_alb.h>
 #include <net/bond_options.h>
+#include <net/ipv6.h>
+#include <net/addrconf.h>
 
 #define BOND_MAX_ARP_TARGETS	16
 
@@ -146,6 +148,7 @@ struct bond_params {
 	struct reciprocal_value reciprocal_packets_per_slave;
 	u16 ad_actor_sys_prio;
 	u16 ad_user_port_key;
+	struct in6_addr ns_targets[BOND_MAX_ARP_TARGETS];
 
 	/* 2 bytes of padding : see ether_addr_equal_64bits() */
 	u8 ad_actor_system[ETH_ALEN + 2];
@@ -499,6 +502,13 @@ static inline int bond_is_ip_target_ok(__be32 addr)
 	return !ipv4_is_lbcast(addr) && !ipv4_is_zeronet(addr);
 }
 
+static inline int bond_is_ip6_target_ok(struct in6_addr *addr)
+{
+	return !ipv6_addr_any(addr) &&
+	       !ipv6_addr_loopback(addr) &&
+	       !ipv6_addr_is_multicast(addr);
+}
+
 /* Get the oldest arp which we've received on this slave for bond's
  * arp_targets.
  */
@@ -619,6 +629,18 @@ static inline __be32 bond_confirm_addr(struct net_device *dev, __be32 dst, __be3
 	return addr;
 }
 
+static inline bool bond_do_ns_validate(struct bonding *bond)
+{
+	int i;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
+		if (!ipv6_addr_any(&bond->params.ns_targets[i]))
+			return true;
+	}
+
+	return false;
+}
+
 struct bond_net {
 	struct net		*net;	/* Associated network namespace */
 	struct list_head	dev_list;
@@ -629,6 +651,7 @@ struct bond_net {
 };
 
 int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond, struct slave *slave);
+int bond_na_rcv(const struct sk_buff *skb, struct bonding *bond, struct slave *slave);
 netdev_tx_t bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb, struct net_device *slave_dev);
 int bond_create(struct net *net, const char *name);
 int bond_create_sysfs(struct bond_net *net);
@@ -749,6 +772,19 @@ static inline int bond_get_targets_ip(__be32 *targets, __be32 ip)
 	return -1;
 }
 
+static inline int bond_get_targets_ip6(struct in6_addr *targets, struct in6_addr *ip)
+{
+	int i;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
+		if (ipv6_addr_equal(&targets[i], ip))
+			return i;
+		else if (ipv6_addr_any(&targets[i]))
+			break;
+
+	return -1;
+}
+
 /* exported from bond_main.c */
 extern unsigned int bond_net_id;
 
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 04341d86585d..d2a7869ddfcb 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -459,10 +459,19 @@ void ndisc_cleanup(void);
 
 int ndisc_rcv(struct sk_buff *skb);
 
+void ip6_nd_hdr(struct sk_buff *skb,
+		       const struct in6_addr *saddr,
+		       const struct in6_addr *daddr,
+		       int hop_limit, int len);
+struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
+				const struct in6_addr *saddr, u64 nonce);
 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 		   u64 nonce);
 
+void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
+		    const struct in6_addr *saddr);
+
 void ndisc_send_rs(struct net_device *dev,
 		   const struct in6_addr *saddr, const struct in6_addr *daddr);
 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 4ac53b30b6dc..fc300b752f8d 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -859,6 +859,7 @@ enum {
 	IFLA_BOND_PEER_NOTIF_DELAY,
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
+	IFLA_BOND_NS_IP6_TARGET,
 	__IFLA_BOND_MAX,
 };
 
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index f03b597e4121..7b1f8ce69237 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -438,7 +438,7 @@ static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 	return skb;
 }
 
-static void ip6_nd_hdr(struct sk_buff *skb,
+void ip6_nd_hdr(struct sk_buff *skb,
 		       const struct in6_addr *saddr,
 		       const struct in6_addr *daddr,
 		       int hop_limit, int len)
@@ -465,10 +465,10 @@ static void ip6_nd_hdr(struct sk_buff *skb,
 	hdr->saddr = *saddr;
 	hdr->daddr = *daddr;
 }
+EXPORT_SYMBOL(ip6_nd_hdr);
 
-static void ndisc_send_skb(struct sk_buff *skb,
-			   const struct in6_addr *daddr,
-			   const struct in6_addr *saddr)
+void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
+		    const struct in6_addr *saddr)
 {
 	struct dst_entry *dst = skb_dst(skb);
 	struct net *net = dev_net(skb->dev);
@@ -515,6 +515,7 @@ static void ndisc_send_skb(struct sk_buff *skb,
 
 	rcu_read_unlock();
 }
+EXPORT_SYMBOL(ndisc_send_skb);
 
 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 		   const struct in6_addr *solicited_addr,
@@ -598,22 +599,16 @@ static void ndisc_send_unsol_na(struct net_device *dev)
 	in6_dev_put(idev);
 }
 
-void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
-		   const struct in6_addr *daddr, const struct in6_addr *saddr,
-		   u64 nonce)
+struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
+				const struct in6_addr *saddr, u64 nonce)
 {
 	struct sk_buff *skb;
-	struct in6_addr addr_buf;
 	int inc_opt = dev->addr_len;
 	int optlen = 0;
 	struct nd_msg *msg;
 
-	if (!saddr) {
-		if (ipv6_get_lladdr(dev, &addr_buf,
-				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
-			return;
-		saddr = &addr_buf;
-	}
+	if (!saddr)
+		return NULL;
 
 	if (ipv6_addr_any(saddr))
 		inc_opt = false;
@@ -625,7 +620,7 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 
 	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 	if (!skb)
-		return;
+		return NULL;
 
 	msg = skb_put(skb, sizeof(*msg));
 	*msg = (struct nd_msg) {
@@ -647,7 +642,28 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 		memcpy(opt + 2, &nonce, 6);
 	}
 
-	ndisc_send_skb(skb, daddr, saddr);
+	return skb;
+}
+EXPORT_SYMBOL(ndisc_ns_create);
+
+void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
+		   const struct in6_addr *daddr, const struct in6_addr *saddr,
+		   u64 nonce)
+{
+	struct sk_buff *skb;
+	struct in6_addr addr_buf;
+
+	if (!saddr) {
+		if (ipv6_get_lladdr(dev, &addr_buf,
+				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
+			return;
+		saddr = &addr_buf;
+	}
+
+	skb = ndisc_ns_create(dev, solicit, saddr, nonce);
+
+	if (skb)
+		ndisc_send_skb(skb, daddr, saddr);
 }
 
 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
diff --git a/tools/include/uapi/linux/if_link.h b/tools/include/uapi/linux/if_link.h
index 4772a115231a..2df505cfbff4 100644
--- a/tools/include/uapi/linux/if_link.h
+++ b/tools/include/uapi/linux/if_link.h
@@ -656,6 +656,7 @@ enum {
 	IFLA_BOND_PEER_NOTIF_DELAY,
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
+	IFLA_BOND_NS_IP6_TARGET,
 	__IFLA_BOND_MAX,
 };
 
-- 
2.31.1

