3 files changed, 90 insertions, 0 deletions

diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
index 0c3b1670b0d1..3b6929dec748 100644
--- a/net/netfilter/ipvs/Kconfig
+++ b/net/netfilter/ipvs/Kconfig
@@ -152,6 +152,16 @@ config	IP_VS_WLC
           If you want to compile it in kernel, say Y. To compile it as a
           module, choose M here. If unsure, say N.
 
+config  IP_VS_FO
+                tristate "weighted failover scheduling"
+        ---help---
+          The weighted failover scheduling algorithm directs network
+          connections to the server with the highest weight that is
+          currently available.
+
+          If you want to compile it in kernel, say Y. To compile it as a
+          module, choose M here. If unsure, say N.
+
 config  IP_VS_LBLC
         tristate "locality-based least-connection scheduling"
         ---help---
diff --git a/net/netfilter/ipvs/Makefile b/net/netfilter/ipvs/Makefile
index 34ee602ddb66..38b2723b2e3d 100644
--- a/net/netfilter/ipvs/Makefile
+++ b/net/netfilter/ipvs/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_IP_VS_RR) += ip_vs_rr.o
 obj-$(CONFIG_IP_VS_WRR) += ip_vs_wrr.o
 obj-$(CONFIG_IP_VS_LC) += ip_vs_lc.o
 obj-$(CONFIG_IP_VS_WLC) += ip_vs_wlc.o
+obj-$(CONFIG_IP_VS_FO) += ip_vs_fo.o
 obj-$(CONFIG_IP_VS_LBLC) += ip_vs_lblc.o
 obj-$(CONFIG_IP_VS_LBLCR) += ip_vs_lblcr.o
 obj-$(CONFIG_IP_VS_DH) += ip_vs_dh.o
diff --git a/net/netfilter/ipvs/ip_vs_fo.c b/net/netfilter/ipvs/ip_vs_fo.c
new file mode 100644
index 000000000000..6a2647d471ff
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_fo.c
@@ -0,0 +1,79 @@
+/*
+ * IPVS:        Weighted Fail Over module
+ *
+ * Authors:     Kenny Mathis <kmathis@chokepoint.net>
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ *     Kenny Mathis            :     added initial functionality based on weight
+ *
+ */
+
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <net/ip_vs.h>
+
+/* Weighted Fail Over Module */
+static struct ip_vs_dest *
+ip_vs_fo_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
+                  struct ip_vs_iphdr *iph)
+{
+        struct ip_vs_dest *dest, *hweight = NULL;
+        int hw = 0; /* Track highest weight */
+
+        IP_VS_DBG(6, "ip_vs_fo_schedule(): Scheduling...\n");
+
+        /* Basic failover functionality
+         * Find virtual server with highest weight and send it traffic
+         */
+        list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
+                if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
+                    atomic_read(&dest->weight) > hw) {
+                        hweight = dest;
+                        hw = atomic_read(&dest->weight);
+                }
+        }
+
+        if (hweight) {
+                IP_VS_DBG_BUF(6, "FO: server %s:%u activeconns %d weight %d\n",
+                              IP_VS_DBG_ADDR(svc->af, &hweight->addr),
+                              ntohs(hweight->port),
+                              atomic_read(&hweight->activeconns),
+                              atomic_read(&hweight->weight));
+                return hweight;
+        }
+
+        ip_vs_scheduler_err(svc, "no destination available");
+        return NULL;
+}
+
+static struct ip_vs_scheduler ip_vs_fo_scheduler = {
+        .name =                 "fo",
+        .refcnt =               ATOMIC_INIT(0),
+        .module =               THIS_MODULE,
+        .n_list =               LIST_HEAD_INIT(ip_vs_fo_scheduler.n_list),
+        .schedule =             ip_vs_fo_schedule,
+};
+
+static int __init ip_vs_fo_init(void)
+{
+        return register_ip_vs_scheduler(&ip_vs_fo_scheduler);
+}
+
+static void __exit ip_vs_fo_cleanup(void)
+{
+        unregister_ip_vs_scheduler(&ip_vs_fo_scheduler);
+        synchronize_rcu();
+}
+
+module_init(ip_vs_fo_init);
+module_exit(ip_vs_fo_cleanup);
+MODULE_LICENSE("GPL");