static int sync_thread(void *startup)
{
DECLARE_WAITQUEUE(wait, current);
mm_segment_t oldmm;
int state;
MOD_INC_USE_COUNT;
daemonize();
oldmm = get_fs();
set_fs(KERNEL_DS);
if (ip_vs_sync_state == IP_VS_STATE_MASTER)
sprintf(current->comm, "ipvs_syncmaster");
else if (ip_vs_sync_state == IP_VS_STATE_BACKUP)
sprintf(current->comm, "ipvs_syncbackup");
else IP_VS_BUG();
spin_lock_irq(¤t->sigmask_lock);
siginitsetinv(¤t->blocked, 0);
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
/* set up multicast address */
mcast_addr.sin_family = AF_INET;
mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
add_wait_queue(&sync_wait, &wait);
state = ip_vs_sync_state;
sync_pid = current->pid;
IP_VS_INFO("sync thread started.\n");
complete((struct completion *)startup);
/* processing master/backup loop here */
if (state == IP_VS_STATE_MASTER)
sync_master_loop();
else if (state == IP_VS_STATE_BACKUP)
sync_backup_loop();
else IP_VS_BUG();
remove_wait_queue(&sync_wait, &wait);
/* thread exits */
sync_pid = 0;
IP_VS_INFO("sync thread stopped!\n");
set_fs(oldmm);
MOD_DEC_USE_COUNT;
stop_sync = 0;
wake_up(&stop_sync_wait);
return 0;
}
/*
* Unregister a scheduler from the scheduler list
*/
int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler)
{
if (!scheduler) {
IP_VS_ERR( "unregister_ip_vs_scheduler(): NULL arg\n");
return -EINVAL;
}
write_lock_bh(&__ip_vs_sched_lock);
if (scheduler->n_list.next == &scheduler->n_list) {
write_unlock_bh(&__ip_vs_sched_lock);
IP_VS_ERR("unregister_ip_vs_scheduler(): [%s] scheduler "
"is not in the list. failed\n", scheduler->name);
return -EINVAL;
}
/*
* Remove it from the d-linked scheduler list
*/
list_del(&scheduler->n_list);
write_unlock_bh(&__ip_vs_sched_lock);
MOD_DEC_USE_COUNT;
IP_VS_INFO("[%s] scheduler unregistered.\n", scheduler->name);
return 0;
}
int __init ip_vs_protocol_init(void)
{
char protocols[64];
#define REGISTER_PROTOCOL(p) \
do { \
register_ip_vs_protocol(p); \
strcat(protocols, ", "); \
strcat(protocols, (p)->name); \
} while (0)
protocols[0] = '\0';
protocols[2] = '\0';
#ifdef CONFIG_IP_VS_PROTO_TCP
REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
#endif
#ifdef CONFIG_IP_VS_PROTO_UDP
REGISTER_PROTOCOL(&ip_vs_protocol_udp);
#endif
#ifdef CONFIG_IP_VS_PROTO_AH
REGISTER_PROTOCOL(&ip_vs_protocol_ah);
#endif
#ifdef CONFIG_IP_VS_PROTO_ESP
REGISTER_PROTOCOL(&ip_vs_protocol_esp);
#endif
IP_VS_INFO("Registered protocols (%s)\n", &protocols[2]);
return 0;
}
int stop_sync_thread(void)
{
DECLARE_WAITQUEUE(wait, current);
if (!sync_pid)
return -ESRCH;
IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
IP_VS_INFO("stopping sync thread %d ...\n", sync_pid);
__set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&stop_sync_wait, &wait);
ip_vs_sync_state = IP_VS_STATE_NONE;
stop_sync = 1;
wake_up(&sync_wait);
schedule();
__set_current_state(TASK_RUNNING);
remove_wait_queue(&stop_sync_wait, &wait);
/* Note: no need to reap the sync thread, because its parent
process is the init process */
if (stop_sync)
IP_VS_BUG();
return 0;
}
static void __exit ip_vs_cleanup(void)
{
nf_unregister_hook(&ip_vs_forward_icmp_ops);
nf_unregister_hook(&ip_vs_post_routing_ops);
nf_unregister_hook(&ip_vs_out_ops);
nf_unregister_hook(&ip_vs_in_ops);
ip_vs_app_cleanup();
ip_vs_conn_cleanup();
ip_vs_control_cleanup();
IP_VS_INFO("ipvs unloaded.\n");
}
/*
* Weighted Round-Robin Scheduling
*/
static struct ip_vs_dest *
ip_vs_wrr_schedule(struct ip_vs_service *svc, struct iphdr *iph)
{
struct ip_vs_dest *dest;
struct ip_vs_wrr_mark *mark = svc->sched_data;
IP_VS_DBG(6, "ip_vs_wrr_schedule(): Scheduling...\n");
/*
* This loop will always terminate, because 0<mark->cw<max_weight,
* and at least one server has its weight equal to max_weight.
*/
write_lock(&svc->sched_lock);
while (1) {
if (mark->cl == &svc->destinations) {
/* it is at the head of the destination list */
if (mark->cl == mark->cl->next) {
/* no dest entry */
write_unlock(&svc->sched_lock);
return NULL;
}
mark->cl = svc->destinations.next;
mark->cw -= mark->di;
if (mark->cw <= 0) {
mark->cw = mark->mw;
/*
* Still zero, which means no available servers.
*/
if (mark->cw == 0) {
mark->cl = &svc->destinations;
write_unlock(&svc->sched_lock);
IP_VS_INFO("ip_vs_wrr_schedule(): "
"no available servers\n");
return NULL;
}
}
}
else mark->cl = mark->cl->next;
if (mark->cl != &svc->destinations) {
/* not at the head of the list */
dest = list_entry(mark->cl, struct ip_vs_dest, n_list);
if (atomic_read(&dest->weight) >= mark->cw) {
write_unlock(&svc->sched_lock);
break;
}
}
}
/*
* Register a scheduler in the scheduler list
*/
int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler)
{
struct ip_vs_scheduler *sched;
if (!scheduler) {
IP_VS_ERR("register_ip_vs_scheduler(): NULL arg\n");
return -EINVAL;
}
if (!scheduler->name) {
IP_VS_ERR("register_ip_vs_scheduler(): NULL scheduler_name\n");
return -EINVAL;
}
MOD_INC_USE_COUNT;
/*
* Make sure that the scheduler with this name doesn't exist
* in the scheduler list.
*/
sched = ip_vs_sched_getbyname(scheduler->name);
if (sched) {
ip_vs_scheduler_put(sched);
MOD_DEC_USE_COUNT;
IP_VS_ERR("register_ip_vs_scheduler(): [%s] scheduler "
"already existed in the system\n", scheduler->name);
return -EINVAL;
}
write_lock_bh(&__ip_vs_sched_lock);
if (scheduler->n_list.next != &scheduler->n_list) {
write_unlock_bh(&__ip_vs_sched_lock);
MOD_DEC_USE_COUNT;
IP_VS_ERR("register_ip_vs_scheduler(): [%s] scheduler "
"already linked\n", scheduler->name);
return -EINVAL;
}
/*
* Add it into the d-linked scheduler list
*/
list_add(&scheduler->n_list, &ip_vs_schedulers);
write_unlock_bh(&__ip_vs_sched_lock);
IP_VS_INFO("[%s] scheduler registered.\n", scheduler->name);
return 0;
}
/*
* Initialize IP Virtual Server
*/
static int __init ip_vs_init(void)
{
int ret;
ret = ip_vs_control_init();
if (ret < 0) {
IP_VS_ERR("can't setup control.\n");
goto cleanup_nothing;
}
ip_vs_protocol_init();
ret = ip_vs_app_init();
if (ret < 0) {
IP_VS_ERR("can't setup application helper.\n");
goto cleanup_protocol;
}
ret = ip_vs_conn_init();
if (ret < 0) {
IP_VS_ERR("can't setup connection table.\n");
goto cleanup_app;
}
ret = nf_register_hook(&ip_vs_in_ops);
if (ret < 0) {
IP_VS_ERR("can't register in hook.\n");
goto cleanup_conn;
}
ret = nf_register_hook(&ip_vs_out_ops);
if (ret < 0) {
IP_VS_ERR("can't register out hook.\n");
goto cleanup_inops;
}
ret = nf_register_hook(&ip_vs_post_routing_ops);
if (ret < 0) {
IP_VS_ERR("can't register post_routing hook.\n");
goto cleanup_outops;
}
ret = nf_register_hook(&ip_vs_forward_icmp_ops);
if (ret < 0) {
IP_VS_ERR("can't register forward_icmp hook.\n");
goto cleanup_postroutingops;
}
IP_VS_INFO("ipvs loaded.\n");
return ret;
cleanup_postroutingops:
nf_unregister_hook(&ip_vs_post_routing_ops);
cleanup_outops:
nf_unregister_hook(&ip_vs_out_ops);
cleanup_inops:
nf_unregister_hook(&ip_vs_in_ops);
cleanup_conn:
ip_vs_conn_cleanup();
cleanup_app:
ip_vs_app_cleanup();
cleanup_protocol:
ip_vs_protocol_cleanup();
ip_vs_control_cleanup();
cleanup_nothing:
return ret;
}