1 files changed, 88 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_lc.c b/net/netfilter/ipvs/ip_vs_lc.c
new file mode 100644
index 000000000..9d34d81fc
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_lc.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IPVS:        Least-Connection Scheduling module
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *
+ * Changes:
+ *     Wensong Zhang            :     added the ip_vs_lc_update_svc
+ *     Wensong Zhang            :     added any dest with weight=0 is quiesced
+ */
+
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <net/ip_vs.h>
+
+/*
+ *	Least Connection scheduling
+ */
+static struct ip_vs_dest *
+ip_vs_lc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
+		  struct ip_vs_iphdr *iph)
+{
+	struct ip_vs_dest *dest, *least = NULL;
+	unsigned int loh = 0, doh;
+
+	IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
+
+	/*
+	 * Simply select the server with the least number of
+	 *        (activeconns<<5) + inactconns
+	 * Except whose weight is equal to zero.
+	 * If the weight is equal to zero, it means that the server is
+	 * quiesced, the existing connections to the server still get
+	 * served, but no new connection is assigned to the server.
+	 */
+
+	list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
+		if ((dest->flags & IP_VS_DEST_F_OVERLOAD) ||
+		    atomic_read(&dest->weight) == 0)
+			continue;
+		doh = ip_vs_dest_conn_overhead(dest);
+		if (!least || doh < loh) {
+			least = dest;
+			loh = doh;
+		}
+	}
+
+	if (!least)
+		ip_vs_scheduler_err(svc, "no destination available");
+	else
+		IP_VS_DBG_BUF(6, "LC: server %s:%u activeconns %d "
+			      "inactconns %d\n",
+			      IP_VS_DBG_ADDR(least->af, &least->addr),
+			      ntohs(least->port),
+			      atomic_read(&least->activeconns),
+			      atomic_read(&least->inactconns));
+
+	return least;
+}
+
+
+static struct ip_vs_scheduler ip_vs_lc_scheduler = {
+	.name =			"lc",
+	.refcnt =		ATOMIC_INIT(0),
+	.module =		THIS_MODULE,
+	.n_list =		LIST_HEAD_INIT(ip_vs_lc_scheduler.n_list),
+	.schedule =		ip_vs_lc_schedule,
+};
+
+
+static int __init ip_vs_lc_init(void)
+{
+	return register_ip_vs_scheduler(&ip_vs_lc_scheduler) ;
+}
+
+static void __exit ip_vs_lc_cleanup(void)
+{
+	unregister_ip_vs_scheduler(&ip_vs_lc_scheduler);
+	synchronize_rcu();
+}
+
+module_init(ip_vs_lc_init);
+module_exit(ip_vs_lc_cleanup);
+MODULE_LICENSE("GPL");