// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IPVS: Weighted Fail Over module
*
* Authors: Kenny Mathis <[email protected]>
*
* 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(hweight->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");
MODULE_DESCRIPTION("ipvs weighted failover scheduler");