1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * IPVS: Weighted Fail Over module
5 * Authors: Kenny Mathis <kmathis@chokepoint.net>
8 * Kenny Mathis : added initial functionality based on weight
11 #define KMSG_COMPONENT "IPVS"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/module.h>
15 #include <linux/kernel.h>
17 #include <net/ip_vs.h>
19 /* Weighted Fail Over Module */
20 static struct ip_vs_dest *
21 ip_vs_fo_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
22 struct ip_vs_iphdr *iph)
24 struct ip_vs_dest *dest, *hweight = NULL;
25 int hw = 0; /* Track highest weight */
27 IP_VS_DBG(6, "ip_vs_fo_schedule(): Scheduling...\n");
29 /* Basic failover functionality
30 * Find virtual server with highest weight and send it traffic
32 list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
33 if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
34 atomic_read(&dest->weight) > hw) {
36 hw = atomic_read(&dest->weight);
41 IP_VS_DBG_BUF(6, "FO: server %s:%u activeconns %d weight %d\n",
42 IP_VS_DBG_ADDR(hweight->af, &hweight->addr),
44 atomic_read(&hweight->activeconns),
45 atomic_read(&hweight->weight));
49 ip_vs_scheduler_err(svc, "no destination available");
53 static struct ip_vs_scheduler ip_vs_fo_scheduler = {
55 .refcnt = ATOMIC_INIT(0),
56 .module = THIS_MODULE,
57 .n_list = LIST_HEAD_INIT(ip_vs_fo_scheduler.n_list),
58 .schedule = ip_vs_fo_schedule,
61 static int __init ip_vs_fo_init(void)
63 return register_ip_vs_scheduler(&ip_vs_fo_scheduler);
66 static void __exit ip_vs_fo_cleanup(void)
68 unregister_ip_vs_scheduler(&ip_vs_fo_scheduler);
72 module_init(ip_vs_fo_init);
73 module_exit(ip_vs_fo_cleanup);
74 MODULE_LICENSE("GPL");
75 MODULE_DESCRIPTION("ipvs weighted failover scheduler");