diff options
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_sched.c')
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_sched.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_sched.c b/net/netfilter/ipvs/ip_vs_sched.c new file mode 100644 index 000000000..d4903723b --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_sched.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IPVS An implementation of the IP virtual server support for the + * LINUX operating system. IPVS is now implemented as a module + * over the Netfilter framework. IPVS can be used to build a + * high-performance and highly available server based on a + * cluster of servers. + * + * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> + * Peter Kese <peter.kese@ijs.si> + * + * Changes: + */ + +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <asm/string.h> +#include <linux/kmod.h> +#include <linux/sysctl.h> + +#include <net/ip_vs.h> + +EXPORT_SYMBOL(ip_vs_scheduler_err); +/* + * IPVS scheduler list + */ +static LIST_HEAD(ip_vs_schedulers); + +/* semaphore for schedulers */ +static DEFINE_MUTEX(ip_vs_sched_mutex); + + +/* + * Bind a service with a scheduler + */ +int ip_vs_bind_scheduler(struct ip_vs_service *svc, + struct ip_vs_scheduler *scheduler) +{ + int ret; + + if (scheduler->init_service) { + ret = scheduler->init_service(svc); + if (ret) { + pr_err("%s(): init error\n", __func__); + return ret; + } + } + rcu_assign_pointer(svc->scheduler, scheduler); + return 0; +} + + +/* + * Unbind a service with its scheduler + */ +void ip_vs_unbind_scheduler(struct ip_vs_service *svc, + struct ip_vs_scheduler *sched) +{ + struct ip_vs_scheduler *cur_sched; + + cur_sched = rcu_dereference_protected(svc->scheduler, 1); + /* This check proves that old 'sched' was installed */ + if (!cur_sched) + return; + + if (sched->done_service) + sched->done_service(svc); + /* svc->scheduler can be set to NULL only by caller */ +} + + +/* + * Get scheduler in the scheduler list by name + */ +static struct ip_vs_scheduler *ip_vs_sched_getbyname(const char *sched_name) +{ + struct ip_vs_scheduler *sched; + + IP_VS_DBG(2, "%s(): sched_name \"%s\"\n", __func__, sched_name); + + mutex_lock(&ip_vs_sched_mutex); + + list_for_each_entry(sched, &ip_vs_schedulers, n_list) { + /* + * Test and get the modules atomically + */ + if (sched->module && !try_module_get(sched->module)) { + /* + * This scheduler is just deleted + */ + continue; + } + if (strcmp(sched_name, sched->name)==0) { + /* HIT */ + mutex_unlock(&ip_vs_sched_mutex); + return sched; + } + module_put(sched->module); + } + + mutex_unlock(&ip_vs_sched_mutex); + return NULL; +} + + +/* + * Lookup scheduler and try to load it if it doesn't exist + */ +struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name) +{ + struct ip_vs_scheduler *sched; + + /* + * Search for the scheduler by sched_name + */ + sched = ip_vs_sched_getbyname(sched_name); + + /* + * If scheduler not found, load the module and search again + */ + if (sched == NULL) { + request_module("ip_vs_%s", sched_name); + sched = ip_vs_sched_getbyname(sched_name); + } + + return sched; +} + +void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler) +{ + if (scheduler) + module_put(scheduler->module); +} + +/* + * Common error output helper for schedulers + */ + +void ip_vs_scheduler_err(struct ip_vs_service *svc, const char *msg) +{ + struct ip_vs_scheduler *sched = rcu_dereference(svc->scheduler); + char *sched_name = sched ? sched->name : "none"; + + if (svc->fwmark) { + IP_VS_ERR_RL("%s: FWM %u 0x%08X - %s\n", + sched_name, svc->fwmark, svc->fwmark, msg); +#ifdef CONFIG_IP_VS_IPV6 + } else if (svc->af == AF_INET6) { + IP_VS_ERR_RL("%s: %s [%pI6c]:%d - %s\n", + sched_name, ip_vs_proto_name(svc->protocol), + &svc->addr.in6, ntohs(svc->port), msg); +#endif + } else { + IP_VS_ERR_RL("%s: %s %pI4:%d - %s\n", + sched_name, ip_vs_proto_name(svc->protocol), + &svc->addr.ip, ntohs(svc->port), msg); + } +} + +/* + * Register a scheduler in the scheduler list + */ +int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler) +{ + struct ip_vs_scheduler *sched; + + if (!scheduler) { + pr_err("%s(): NULL arg\n", __func__); + return -EINVAL; + } + + if (!scheduler->name) { + pr_err("%s(): NULL scheduler_name\n", __func__); + return -EINVAL; + } + + /* increase the module use count */ + if (!ip_vs_use_count_inc()) + return -ENOENT; + + mutex_lock(&ip_vs_sched_mutex); + + if (!list_empty(&scheduler->n_list)) { + mutex_unlock(&ip_vs_sched_mutex); + ip_vs_use_count_dec(); + pr_err("%s(): [%s] scheduler already linked\n", + __func__, scheduler->name); + return -EINVAL; + } + + /* + * Make sure that the scheduler with this name doesn't exist + * in the scheduler list. + */ + list_for_each_entry(sched, &ip_vs_schedulers, n_list) { + if (strcmp(scheduler->name, sched->name) == 0) { + mutex_unlock(&ip_vs_sched_mutex); + ip_vs_use_count_dec(); + pr_err("%s(): [%s] scheduler already existed " + "in the system\n", __func__, scheduler->name); + return -EINVAL; + } + } + /* + * Add it into the d-linked scheduler list + */ + list_add(&scheduler->n_list, &ip_vs_schedulers); + mutex_unlock(&ip_vs_sched_mutex); + + pr_info("[%s] scheduler registered.\n", scheduler->name); + + return 0; +} + + +/* + * Unregister a scheduler from the scheduler list + */ +int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler) +{ + if (!scheduler) { + pr_err("%s(): NULL arg\n", __func__); + return -EINVAL; + } + + mutex_lock(&ip_vs_sched_mutex); + if (list_empty(&scheduler->n_list)) { + mutex_unlock(&ip_vs_sched_mutex); + pr_err("%s(): [%s] scheduler is not in the list. failed\n", + __func__, scheduler->name); + return -EINVAL; + } + + /* + * Remove it from the d-linked scheduler list + */ + list_del(&scheduler->n_list); + mutex_unlock(&ip_vs_sched_mutex); + + /* decrease the module use count */ + ip_vs_use_count_dec(); + + pr_info("[%s] scheduler unregistered.\n", scheduler->name); + + return 0; +} |