1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * IPVS: Weighted Fail Over module 4 * 5 * Authors: Kenny Mathis <kmathis@chokepoint.net> 6 * 7 * Changes: 8 * Kenny Mathis : added initial functionality based on weight 9 */ 10 11#define KMSG_COMPONENT "IPVS" 12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 13 14#include <linux/module.h> 15#include <linux/kernel.h> 16 17#include <net/ip_vs.h> 18 19/* Weighted Fail Over Module */ 20static struct ip_vs_dest * 21ip_vs_fo_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, 22 struct ip_vs_iphdr *iph) 23{ 24 struct ip_vs_dest *dest, *hweight = NULL; 25 int hw = 0; /* Track highest weight */ 26 27 IP_VS_DBG(6, "ip_vs_fo_schedule(): Scheduling...\n"); 28 29 /* Basic failover functionality 30 * Find virtual server with highest weight and send it traffic 31 */ 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) { 35 hweight = dest; 36 hw = atomic_read(&dest->weight); 37 } 38 } 39 40 if (hweight) { 41 IP_VS_DBG_BUF(6, "FO: server %s:%u activeconns %d weight %d\n", 42 IP_VS_DBG_ADDR(hweight->af, &hweight->addr), 43 ntohs(hweight->port), 44 atomic_read(&hweight->activeconns), 45 atomic_read(&hweight->weight)); 46 return hweight; 47 } 48 49 ip_vs_scheduler_err(svc, "no destination available"); 50 return NULL; 51} 52 53static struct ip_vs_scheduler ip_vs_fo_scheduler = { 54 .name = "fo", 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, 59}; 60 61static int __init ip_vs_fo_init(void) 62{ 63 return register_ip_vs_scheduler(&ip_vs_fo_scheduler); 64} 65 66static void __exit ip_vs_fo_cleanup(void) 67{ 68 unregister_ip_vs_scheduler(&ip_vs_fo_scheduler); 69 synchronize_rcu(); 70} 71 72module_init(ip_vs_fo_init); 73module_exit(ip_vs_fo_cleanup); 74MODULE_LICENSE("GPL"); 75MODULE_DESCRIPTION("ipvs weighted failover scheduler"); 76