/*
* 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>
* Julian Anastasov <ja@ssi.bg>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
* with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
* and others. Many code here is taken from IP MASQ code of kernel 2.2.
*
* Changes:
*
*/
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/interrupt.h>
#include <linux/in.h>
#include <linux/net.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h> /* for proc_net_* */
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <net/net_namespace.h>
#include <net/ip_vs.h>
#ifndef CONFIG_IP_VS_TAB_BITS
#define CONFIG_IP_VS_TAB_BITS 12
#endif
/*
* Connection hash size. Default is what was selected at compile time.
*/
static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
/* size and mask values */
int ip_vs_conn_tab_size __read_mostly;
static int ip_vs_conn_tab_mask __read_mostly;
/*
* Connection hash table: for input and output packets lookups of IPVS
*/
static struct hlist_head *ip_vs_conn_tab __read_mostly;
/* SLAB cache for IPVS connections */
static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
/* counter for no client port connections */
static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
/* random value for IPVS connection hash */
static unsigned int ip_vs_conn_rnd __read_mostly;
/*
* Fine locking granularity for big connection hash table
*/
#define CT_LOCKARRAY_BITS 5
#define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS)
#define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1)
struct ip_vs_aligned_lock
{
spinlock_t l;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));
/* lock array for conn table */
static struct ip_vs_aligned_lock
__ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
static inline void ct_write_lock_bh(unsigned int key)
{
spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
}
static inline void ct_write_unlock_bh(unsigned int key)
{
spin_unlock_bh(