bonding: add new option ns_ip6_target

This patch add a new bonding option ns_ip6_target, which correspond
to the arp_ip_target. With this we set IPv6 targets and send IPv6 NS
request to determine the health of the link.

For other related options like the validation, we still use
arp_validate, and will change to ns_validate later.

Note: the sysfs configuration support was removed based on
https://lore.kernel.org/netdev/8863.1645071997@famine

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/bonding.rst

@@ -313,6 +313,17 @@ 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

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 +274,40 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 		if (err)
 			return err;
 	}
+#if IS_ENABLED(CONFIG_IPV6)
+	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 addr6;
+
+			if (nla_len(attr) < sizeof(addr6)) {
+				NL_SET_ERR_MSG(extack, "Invalid IPv6 address");
+				return -EINVAL;
+			}
+
+			addr6 = nla_get_in6_addr(attr);
+
+			if (ipv6_addr_type(&addr6) & IPV6_ADDR_LINKLOCAL) {
+				NL_SET_ERR_MSG(extack, "Invalid IPv6 addr6");
+				return -EINVAL;
+			}
+
+			bond_opt_initextra(&newval, &addr6, sizeof(addr6));
+			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;
+	}
+#endif
 	if (data[IFLA_BOND_ARP_VALIDATE]) {
 		int arp_validate = nla_get_u32(data[IFLA_BOND_ARP_VALIDATE]);
 
@@ -526,6 +562,9 @@ 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_NS_TARGETS +
 		0;
 }
 
@@ -603,6 +642,26 @@ static int bond_fill_info(struct sk_buff *skb,
 			bond->params.arp_all_targets))
 		goto nla_put_failure;
 
+#if IS_ENABLED(CONFIG_IPV6)
+	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_NS_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);
+#endif
+
 	primary = rtnl_dereference(bond->primary_slave);
 	if (primary &&
 	    nla_put_u32(skb, IFLA_BOND_PRIMARY, primary->dev->ifindex))

drivers/net/bonding/bond_options.c

@@ -34,6 +34,10 @@ 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);
+#if IS_ENABLED(CONFIG_IPV6)
+static int bond_option_ns_ip6_targets_set(struct bonding *bond,
+					  const struct bond_opt_value *newval);
+#endif
 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 +299,15 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = {
 		.flags = BOND_OPTFLAG_RAWVAL,
 		.set = bond_option_arp_ip_targets_set
 	},
+#if IS_ENABLED(CONFIG_IPV6)
+	[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
+	},
+#endif
 	[BOND_OPT_DOWNDELAY] = {
 		.id = BOND_OPT_DOWNDELAY,
 		.name = "downdelay",
@@ -1184,6 +1197,65 @@ static int bond_option_arp_ip_targets_set(struct bonding *bond,
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
+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_NS_TARGETS) {
+		bond_for_each_slave(bond, slave, iter)
+			slave->target_last_arp_rx[slot] = last_rx;
+		targets[slot] = *target;
+	}
+}
+
+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_NS_TARGETS; i++)
+		_bond_options_ns_ip6_target_set(bond, i, &addr_any, 0);
+}
+
+static int bond_option_ns_ip6_targets_set(struct bonding *bond,
+					  const struct bond_opt_value *newval)
+{
+	struct in6_addr *target = (struct in6_addr *)newval->extra;
+	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 %pI6c specified for addition\n",
+			   target);
+		return -EINVAL;
+	}
+
+	if (bond_get_targets_ip6(targets, target) != -1) { /* dup */
+		netdev_err(bond->dev, "NS target %pI6c 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 %pI6c\n", target);
+
+	_bond_options_ns_ip6_target_set(bond, index, target, jiffies);
+
+	return 0;
+}
+#endif
+
 static int bond_option_arp_validate_set(struct bonding *bond,
 					const struct bond_opt_value *newval)
 {

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
 };
 
@@ -140,5 +141,8 @@ static inline void __bond_opt_init(struct bond_opt_value *optval,
 	__bond_opt_init(optval, NULL, ULLONG_MAX, extra, extra_len)
 
 void bond_option_arp_ip_targets_clear(struct bonding *bond);
+#if IS_ENABLED(CONFIG_IPV6)
+void bond_option_ns_ip6_targets_clear(struct bonding *bond);
+#endif
 
 #endif /* _NET_BOND_OPTIONS_H */

include/net/bonding.h

@@ -503,6 +503,13 @@ 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.
  */

include/uapi/linux/if_link.h

@@ -860,6 +860,7 @@ enum {
 	IFLA_BOND_PEER_NOTIF_DELAY,
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
+	IFLA_BOND_NS_IP6_TARGET,
 	__IFLA_BOND_MAX,
 };
 

tools/include/uapi/linux/if_link.h

@@ -860,6 +860,7 @@ enum {
 	IFLA_BOND_PEER_NOTIF_DELAY,
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
+	IFLA_BOND_NS_IP6_TARGET,
 	__IFLA_BOND_MAX,
 };