tipc: make cluster size threshold for monitoring configurable

In this commit, we introduce support to configure the minimum
threshold to activate the new link monitoring algorithm.

Reviewed-by: Jon Maloy <[e-mail]>
Signed-off-by: Parthasarathy Bhuvaragan <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/tipc_netlink.h

···
 	TIPC_NL_NET_GET,
 	TIPC_NL_NET_SET,
 	TIPC_NL_NAME_TABLE_GET,
+	TIPC_NL_MON_SET,
 
 	__TIPC_NL_CMD_MAX,
 	TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
···
 	TIPC_NLA_NODE,			/* nest */
 	TIPC_NLA_NET,			/* nest */
 	TIPC_NLA_NAME_TABLE,		/* nest */
+	TIPC_NLA_MON,			/* nest */
 
 	__TIPC_NLA_MAX,
 	TIPC_NLA_MAX = __TIPC_NLA_MAX - 1
···
 
 	__TIPC_NLA_NAME_TABLE_MAX,
 	TIPC_NLA_NAME_TABLE_MAX = __TIPC_NLA_NAME_TABLE_MAX - 1
+};
+
+/* Monitor info */
+enum {
+	TIPC_NLA_MON_UNSPEC,
+	TIPC_NLA_MON_ACTIVATION_THRESHOLD,	/* u32 */
+
+	__TIPC_NLA_MON_MAX,
+	TIPC_NLA_MON_MAX = __TIPC_NLA_MON_MAX - 1
 };
 
 /* Publication info */

net/tipc/monitor.c

···
 	kfree(self);
 	kfree(mon);
 }
+
+int tipc_nl_monitor_set_threshold(struct net *net, u32 cluster_size)
+{
+	struct tipc_net *tn = tipc_net(net);
+
+	if (cluster_size > TIPC_CLUSTER_SIZE)
+		return -EINVAL;
+
+	tn->mon_threshold = cluster_size;
+
+	return 0;
+}

net/tipc/monitor.h

···
 			int bearer_id);
 void tipc_mon_remove_peer(struct net *net, u32 addr, int bearer_id);
 
+int tipc_nl_monitor_set_threshold(struct net *net, u32 cluster_size);
 extern const int tipc_max_domain_size;
 #endif

net/tipc/netlink.c

···
 	[TIPC_NLA_MEDIA]	= { .type = NLA_NESTED, },
 	[TIPC_NLA_NODE]		= { .type = NLA_NESTED, },
 	[TIPC_NLA_NET]		= { .type = NLA_NESTED, },
-	[TIPC_NLA_NAME_TABLE]	= { .type = NLA_NESTED, }
+	[TIPC_NLA_NAME_TABLE]	= { .type = NLA_NESTED, },
+	[TIPC_NLA_MON]		= { .type = NLA_NESTED, },
 };
 
 const struct nla_policy
 tipc_nl_name_table_policy[TIPC_NLA_NAME_TABLE_MAX + 1] = {
 	[TIPC_NLA_NAME_TABLE_UNSPEC]	= { .type = NLA_UNSPEC },
 	[TIPC_NLA_NAME_TABLE_PUBL]	= { .type = NLA_NESTED }
+};
+
+const struct nla_policy tipc_nl_monitor_policy[TIPC_NLA_MON_MAX + 1] = {
+	[TIPC_NLA_MON_UNSPEC]			= { .type = NLA_UNSPEC },
+	[TIPC_NLA_MON_ACTIVATION_THRESHOLD]	= { .type = NLA_U32 },
 };
 
 const struct nla_policy tipc_nl_sock_policy[TIPC_NLA_SOCK_MAX + 1] = {
···
 		.cmd	= TIPC_NL_NAME_TABLE_GET,
 		.dumpit	= tipc_nl_name_table_dump,
 		.policy = tipc_nl_policy,
-	}
+	},
+	{
+		.cmd	= TIPC_NL_MON_SET,
+		.doit	= tipc_nl_node_set_monitor,
+		.policy = tipc_nl_policy,
+	},
 };
 
 int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***attr)

net/tipc/netlink.h

···
 extern const struct nla_policy tipc_nl_bearer_policy[];
 extern const struct nla_policy tipc_nl_media_policy[];
 extern const struct nla_policy tipc_nl_udp_policy[];
+extern const struct nla_policy tipc_nl_monitor_policy[];
 
 int tipc_netlink_start(void);
 int tipc_netlink_compat_start(void);

net/tipc/node.c

···
 
 	return skb->len;
 }
+
+int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	int err;
+
+	if (!info->attrs[TIPC_NLA_MON])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_MON_MAX,
+			       info->attrs[TIPC_NLA_MON],
+			       tipc_nl_monitor_policy);
+	if (err)
+		return err;
+
+	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
+		u32 val;
+
+		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
+		err = tipc_nl_monitor_set_threshold(net, val);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}

net/tipc/node.h

···
 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info);
 
+int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info);
 #endif