bonding: guard ns_targets by CONFIG_IPV6

Guard ns_targets in struct bond_params by CONFIG_IPV6, which could save
256 bytes if IPv6 not configed. Also add this protection for function
bond_is_ip6_target_ok() and bond_get_targets_ip6().

Remove the IS_ENABLED() check for bond_opts[] as this will make
BOND_OPT_NS_TARGETS uninitialized if CONFIG_IPV6 not enabled. Add
a dummy bond_option_ns_ip6_targets_set() for this situation.

Fixes: 4e24be0 ("bonding: add new parameter ns_targets")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Jonathan Toppins <jtoppins@redhat.com>
Link: https://lore.kernel.org/r/20220531063727.224043-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/bonding/bond_main.c

@@ -6159,7 +6159,9 @@ 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));
+#if IS_ENABLED(CONFIG_IPV6)
 	memset(params->ns_targets, 0, sizeof(struct in6_addr) * BOND_MAX_NS_TARGETS);
+#endif
 
 	return 0;
 }

drivers/net/bonding/bond_options.c

@@ -34,10 +34,8 @@ 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,
@@ -299,15 +297,13 @@ 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",
@@ -1254,6 +1250,12 @@ static int bond_option_ns_ip6_targets_set(struct bonding *bond,
 
 	return 0;
 }
+#else
+static int bond_option_ns_ip6_targets_set(struct bonding *bond,
+					  const struct bond_opt_value *newval)
+{
+	return -EPERM;
+}
 #endif
 
 static int bond_option_arp_validate_set(struct bonding *bond,

include/net/bonding.h

@@ -149,7 +149,9 @@ struct bond_params {
 	struct reciprocal_value reciprocal_packets_per_slave;
 	u16 ad_actor_sys_prio;
 	u16 ad_user_port_key;
+#if IS_ENABLED(CONFIG_IPV6)
 	struct in6_addr ns_targets[BOND_MAX_NS_TARGETS];
+#endif
 
 	/* 2 bytes of padding : see ether_addr_equal_64bits() */
 	u8 ad_actor_system[ETH_ALEN + 2];
@@ -503,12 +505,14 @@ static inline int bond_is_ip_target_ok(__be32 addr)
 	return !ipv4_is_lbcast(addr) && !ipv4_is_zeronet(addr);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 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);
 }
+#endif
 
 /* Get the oldest arp which we've received on this slave for bond's
  * arp_targets.
@@ -746,6 +750,7 @@ static inline int bond_get_targets_ip(__be32 *targets, __be32 ip)
 	return -1;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static inline int bond_get_targets_ip6(struct in6_addr *targets, struct in6_addr *ip)
 {
 	int i;
@@ -758,6 +763,7 @@ static inline int bond_get_targets_ip6(struct in6_addr *targets, struct in6_addr
 
 	return -1;
 }
+#endif
 
 /* exported from bond_main.c */
 extern unsigned int bond_net_id;