alistair23-linux/net/netfilter/ipvs/ip_vs_conn.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

1445 lines
36 KiB
C

// 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>
* Julian Anastasov <ja@ssi.bg>
*
* 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/inet.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)
/* We need an addrstrlen that works with or without v6 */
#ifdef CONFIG_IP_VS_IPV6
#define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
#else
#define IP_VS_ADDRSTRLEN (8+1)
#endif
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(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
}
static void ip_vs_conn_expire(struct timer_list *t);
/*
* Returns hash value for IPVS connection entry
*/
static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
const union nf_inet_addr *addr,
__be16 port)
{
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
(__force u32)port, proto, ip_vs_conn_rnd) ^
((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
#endif
return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
ip_vs_conn_rnd) ^
((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
}
static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
bool inverse)
{
const union nf_inet_addr *addr;
__be16 port;
if (p->pe_data && p->pe->hashkey_raw)
return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
ip_vs_conn_tab_mask;
if (likely(!inverse)) {
addr = p->caddr;
port = p->cport;
} else {
addr = p->vaddr;
port = p->vport;
}
return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
}
static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
&cp->caddr, cp->cport, NULL, 0, &p);
if (cp->pe) {
p.pe = cp->pe;
p.pe_data = cp->pe_data;
p.pe_data_len = cp->pe_data_len;
}
return ip_vs_conn_hashkey_param(&p, false);
}
/*
* Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
* returns bool success.
*/
static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
{
unsigned int hash;
int ret;
if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
return 0;
/* Hash by protocol, client address and port */
hash = ip_vs_conn_hashkey_conn(cp);
ct_write_lock_bh(hash);
spin_lock(&cp->lock);
if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
cp->flags |= IP_VS_CONN_F_HASHED;
refcount_inc(&cp->refcnt);
hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
ret = 1;
} else {
pr_err("%s(): request for already hashed, called from %pS\n",
__func__, __builtin_return_address(0));
ret = 0;
}
spin_unlock(&cp->lock);
ct_write_unlock_bh(hash);
return ret;
}
/*
* UNhashes ip_vs_conn from ip_vs_conn_tab.
* returns bool success. Caller should hold conn reference.
*/
static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
{
unsigned int hash;
int ret;
/* unhash it and decrease its reference counter */
hash = ip_vs_conn_hashkey_conn(cp);
ct_write_lock_bh(hash);
spin_lock(&cp->lock);
if (cp->flags & IP_VS_CONN_F_HASHED) {
hlist_del_rcu(&cp->c_list);
cp->flags &= ~IP_VS_CONN_F_HASHED;
refcount_dec(&cp->refcnt);
ret = 1;
} else
ret = 0;
spin_unlock(&cp->lock);
ct_write_unlock_bh(hash);
return ret;
}
/* Try to unlink ip_vs_conn from ip_vs_conn_tab.
* returns bool success.
*/
static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
{
unsigned int hash;
bool ret = false;
if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
return refcount_dec_if_one(&cp->refcnt);
hash = ip_vs_conn_hashkey_conn(cp);
ct_write_lock_bh(hash);
spin_lock(&cp->lock);
if (cp->flags & IP_VS_CONN_F_HASHED) {
/* Decrease refcnt and unlink conn only if we are last user */
if (refcount_dec_if_one(&cp->refcnt)) {
hlist_del_rcu(&cp->c_list);
cp->flags &= ~IP_VS_CONN_F_HASHED;
ret = true;
}
}
spin_unlock(&cp->lock);
ct_write_unlock_bh(hash);
return ret;
}
/*
* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
* Called for pkts coming from OUTside-to-INside.
* p->caddr, p->cport: pkt source address (foreign host)
* p->vaddr, p->vport: pkt dest address (load balancer)
*/
static inline struct ip_vs_conn *
__ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
{
unsigned int hash;
struct ip_vs_conn *cp;
hash = ip_vs_conn_hashkey_param(p, false);
rcu_read_lock();
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
if (p->cport == cp->cport && p->vport == cp->vport &&
cp->af == p->af &&
ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
p->protocol == cp->protocol &&
cp->ipvs == p->ipvs) {
if (!__ip_vs_conn_get(cp))
continue;
/* HIT */
rcu_read_unlock();
return cp;
}
}
rcu_read_unlock();
return NULL;
}
struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
{
struct ip_vs_conn *cp;
cp = __ip_vs_conn_in_get(p);
if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
struct ip_vs_conn_param cport_zero_p = *p;
cport_zero_p.cport = 0;
cp = __ip_vs_conn_in_get(&cport_zero_p);
}
IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
ip_vs_proto_name(p->protocol),
IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
cp ? "hit" : "not hit");
return cp;
}
static int
ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
int af, const struct sk_buff *skb,
const struct ip_vs_iphdr *iph,
struct ip_vs_conn_param *p)
{
__be16 _ports[2], *pptr;
pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
if (pptr == NULL)
return 1;
if (likely(!ip_vs_iph_inverse(iph)))
ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
pptr[0], &iph->daddr, pptr[1], p);
else
ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
pptr[1], &iph->saddr, pptr[0], p);
return 0;
}
struct ip_vs_conn *
ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
const struct sk_buff *skb,
const struct ip_vs_iphdr *iph)
{
struct ip_vs_conn_param p;
if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
return NULL;
return ip_vs_conn_in_get(&p);
}
EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
/* Get reference to connection template */
struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
{
unsigned int hash;
struct ip_vs_conn *cp;
hash = ip_vs_conn_hashkey_param(p, false);
rcu_read_lock();
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
if (unlikely(p->pe_data && p->pe->ct_match)) {
if (cp->ipvs != p->ipvs)
continue;
if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
if (__ip_vs_conn_get(cp))
goto out;
}
continue;
}
if (cp->af == p->af &&
ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
/* protocol should only be IPPROTO_IP if
* p->vaddr is a fwmark */
ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
p->af, p->vaddr, &cp->vaddr) &&
p->vport == cp->vport && p->cport == cp->cport &&
cp->flags & IP_VS_CONN_F_TEMPLATE &&
p->protocol == cp->protocol &&
cp->ipvs == p->ipvs) {
if (__ip_vs_conn_get(cp))
goto out;
}
}
cp = NULL;
out:
rcu_read_unlock();
IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
ip_vs_proto_name(p->protocol),
IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
cp ? "hit" : "not hit");
return cp;
}
/* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
* Called for pkts coming from inside-to-OUTside.
* p->caddr, p->cport: pkt source address (inside host)
* p->vaddr, p->vport: pkt dest address (foreign host) */
struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
{
unsigned int hash;
struct ip_vs_conn *cp, *ret=NULL;
/*
* Check for "full" addressed entries
*/
hash = ip_vs_conn_hashkey_param(p, true);
rcu_read_lock();
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
if (p->vport == cp->cport && p->cport == cp->dport &&
cp->af == p->af &&
ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
p->protocol == cp->protocol &&
cp->ipvs == p->ipvs) {
if (!__ip_vs_conn_get(cp))
continue;
/* HIT */
ret = cp;
break;
}
}
rcu_read_unlock();
IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
ip_vs_proto_name(p->protocol),
IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
ret ? "hit" : "not hit");
return ret;
}
struct ip_vs_conn *
ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
const struct sk_buff *skb,
const struct ip_vs_iphdr *iph)
{
struct ip_vs_conn_param p;
if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
return NULL;
return ip_vs_conn_out_get(&p);
}
EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
/*
* Put back the conn and restart its timer with its timeout
*/
static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
{
unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
0 : cp->timeout;
mod_timer(&cp->timer, jiffies+t);
__ip_vs_conn_put(cp);
}
void ip_vs_conn_put(struct ip_vs_conn *cp)
{
if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
(refcount_read(&cp->refcnt) == 1) &&
!timer_pending(&cp->timer))
/* expire connection immediately */
ip_vs_conn_expire(&cp->timer);
else
__ip_vs_conn_put_timer(cp);
}
/*
* Fill a no_client_port connection with a client port number
*/
void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
{
if (ip_vs_conn_unhash(cp)) {
spin_lock_bh(&cp->lock);
if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
atomic_dec(&ip_vs_conn_no_cport_cnt);
cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
cp->cport = cport;
}
spin_unlock_bh(&cp->lock);
/* hash on new dport */
ip_vs_conn_hash(cp);
}
}
/*
* Bind a connection entry with the corresponding packet_xmit.
* Called by ip_vs_conn_new.
*/
static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
{
switch (IP_VS_FWD_METHOD(cp)) {
case IP_VS_CONN_F_MASQ:
cp->packet_xmit = ip_vs_nat_xmit;
break;
case IP_VS_CONN_F_TUNNEL:
#ifdef CONFIG_IP_VS_IPV6
if (cp->daf == AF_INET6)
cp->packet_xmit = ip_vs_tunnel_xmit_v6;
else
#endif
cp->packet_xmit = ip_vs_tunnel_xmit;
break;
case IP_VS_CONN_F_DROUTE:
cp->packet_xmit = ip_vs_dr_xmit;
break;
case IP_VS_CONN_F_LOCALNODE:
cp->packet_xmit = ip_vs_null_xmit;
break;
case IP_VS_CONN_F_BYPASS:
cp->packet_xmit = ip_vs_bypass_xmit;
break;
}
}
#ifdef CONFIG_IP_VS_IPV6
static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
{
switch (IP_VS_FWD_METHOD(cp)) {
case IP_VS_CONN_F_MASQ:
cp->packet_xmit = ip_vs_nat_xmit_v6;
break;
case IP_VS_CONN_F_TUNNEL:
if (cp->daf == AF_INET6)
cp->packet_xmit = ip_vs_tunnel_xmit_v6;
else
cp->packet_xmit = ip_vs_tunnel_xmit;
break;
case IP_VS_CONN_F_DROUTE:
cp->packet_xmit = ip_vs_dr_xmit_v6;
break;
case IP_VS_CONN_F_LOCALNODE:
cp->packet_xmit = ip_vs_null_xmit;
break;
case IP_VS_CONN_F_BYPASS:
cp->packet_xmit = ip_vs_bypass_xmit_v6;
break;
}
}
#endif
static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
{
return atomic_read(&dest->activeconns)
+ atomic_read(&dest->inactconns);
}
/*
* Bind a connection entry with a virtual service destination
* Called just after a new connection entry is created.
*/
static inline void
ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
{
unsigned int conn_flags;
__u32 flags;
/* if dest is NULL, then return directly */
if (!dest)
return;
/* Increase the refcnt counter of the dest */
ip_vs_dest_hold(dest);
conn_flags = atomic_read(&dest->conn_flags);
if (cp->protocol != IPPROTO_UDP)
conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
flags = cp->flags;
/* Bind with the destination and its corresponding transmitter */
if (flags & IP_VS_CONN_F_SYNC) {
/* if the connection is not template and is created
* by sync, preserve the activity flag.
*/
if (!(flags & IP_VS_CONN_F_TEMPLATE))
conn_flags &= ~IP_VS_CONN_F_INACTIVE;
/* connections inherit forwarding method from dest */
flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
}
flags |= conn_flags;
cp->flags = flags;
cp->dest = dest;
IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
"d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
"dest->refcnt:%d\n",
ip_vs_proto_name(cp->protocol),
IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
ip_vs_fwd_tag(cp), cp->state,
cp->flags, refcount_read(&cp->refcnt),
refcount_read(&dest->refcnt));
/* Update the connection counters */
if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
/* It is a normal connection, so modify the counters
* according to the flags, later the protocol can
* update them on state change
*/
if (!(flags & IP_VS_CONN_F_INACTIVE))
atomic_inc(&dest->activeconns);
else
atomic_inc(&dest->inactconns);
} else {
/* It is a persistent connection/template, so increase
the persistent connection counter */
atomic_inc(&dest->persistconns);
}
if (dest->u_threshold != 0 &&
ip_vs_dest_totalconns(dest) >= dest->u_threshold)
dest->flags |= IP_VS_DEST_F_OVERLOAD;
}
/*
* Check if there is a destination for the connection, if so
* bind the connection to the destination.
*/
void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
{
struct ip_vs_dest *dest;
rcu_read_lock();
/* This function is only invoked by the synchronization code. We do
* not currently support heterogeneous pools with synchronization,
* so we can make the assumption that the svc_af is the same as the
* dest_af
*/
dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
cp->dport, &cp->vaddr, cp->vport,
cp->protocol, cp->fwmark, cp->flags);
if (dest) {
struct ip_vs_proto_data *pd;
spin_lock_bh(&cp->lock);
if (cp->dest) {
spin_unlock_bh(&cp->lock);
rcu_read_unlock();
return;
}
/* Applications work depending on the forwarding method
* but better to reassign them always when binding dest */
if (cp->app)
ip_vs_unbind_app(cp);
ip_vs_bind_dest(cp, dest);
spin_unlock_bh(&cp->lock);
/* Update its packet transmitter */
cp->packet_xmit = NULL;
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
ip_vs_bind_xmit_v6(cp);
else
#endif
ip_vs_bind_xmit(cp);
pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
if (pd && atomic_read(&pd->appcnt))
ip_vs_bind_app(cp, pd->pp);
}
rcu_read_unlock();
}
/*
* Unbind a connection entry with its VS destination
* Called by the ip_vs_conn_expire function.
*/
static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
{
struct ip_vs_dest *dest = cp->dest;
if (!dest)
return;
IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
"d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
"dest->refcnt:%d\n",
ip_vs_proto_name(cp->protocol),
IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
ip_vs_fwd_tag(cp), cp->state,
cp->flags, refcount_read(&cp->refcnt),
refcount_read(&dest->refcnt));
/* Update the connection counters */
if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
/* It is a normal connection, so decrease the inactconns
or activeconns counter */
if (cp->flags & IP_VS_CONN_F_INACTIVE) {
atomic_dec(&dest->inactconns);
} else {
atomic_dec(&dest->activeconns);
}
} else {
/* It is a persistent connection/template, so decrease
the persistent connection counter */
atomic_dec(&dest->persistconns);
}
if (dest->l_threshold != 0) {
if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
} else if (dest->u_threshold != 0) {
if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
} else {
if (dest->flags & IP_VS_DEST_F_OVERLOAD)
dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
}
ip_vs_dest_put(dest);
}
static int expire_quiescent_template(struct netns_ipvs *ipvs,
struct ip_vs_dest *dest)
{
#ifdef CONFIG_SYSCTL
return ipvs->sysctl_expire_quiescent_template &&
(atomic_read(&dest->weight) == 0);
#else
return 0;
#endif
}
/*
* Checking if the destination of a connection template is available.
* If available, return 1, otherwise invalidate this connection
* template and return 0.
*/
int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
{
struct ip_vs_dest *dest = ct->dest;
struct netns_ipvs *ipvs = ct->ipvs;
/*
* Checking the dest server status.
*/
if ((dest == NULL) ||
!(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
expire_quiescent_template(ipvs, dest) ||
(cdest && (dest != cdest))) {
IP_VS_DBG_BUF(9, "check_template: dest not available for "
"protocol %s s:%s:%d v:%s:%d "
"-> d:%s:%d\n",
ip_vs_proto_name(ct->protocol),
IP_VS_DBG_ADDR(ct->af, &ct->caddr),
ntohs(ct->cport),
IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
ntohs(ct->vport),
IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
ntohs(ct->dport));
/*
* Invalidate the connection template
*/
if (ct->vport != htons(0xffff)) {
if (ip_vs_conn_unhash(ct)) {
ct->dport = htons(0xffff);
ct->vport = htons(0xffff);
ct->cport = 0;
ip_vs_conn_hash(ct);
}
}
/*
* Simply decrease the refcnt of the template,
* don't restart its timer.
*/
__ip_vs_conn_put(ct);
return 0;
}
return 1;
}
static void ip_vs_conn_rcu_free(struct rcu_head *head)
{
struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
rcu_head);
ip_vs_pe_put(cp->pe);
kfree(cp->pe_data);
kmem_cache_free(ip_vs_conn_cachep, cp);
}
static void ip_vs_conn_expire(struct timer_list *t)
{
struct ip_vs_conn *cp = from_timer(cp, t, timer);
struct netns_ipvs *ipvs = cp->ipvs;
/*
* do I control anybody?
*/
if (atomic_read(&cp->n_control))
goto expire_later;
/* Unlink conn if not referenced anymore */
if (likely(ip_vs_conn_unlink(cp))) {
struct ip_vs_conn *ct = cp->control;
/* delete the timer if it is activated by other users */
del_timer(&cp->timer);
/* does anybody control me? */
if (ct) {
ip_vs_control_del(cp);
/* Drop CTL or non-assured TPL if not used anymore */
if (!cp->timeout && !atomic_read(&ct->n_control) &&
(!(ct->flags & IP_VS_CONN_F_TEMPLATE) ||
!(ct->state & IP_VS_CTPL_S_ASSURED))) {
IP_VS_DBG(4, "drop controlling connection\n");
ct->timeout = 0;
ip_vs_conn_expire_now(ct);
}
}
if ((cp->flags & IP_VS_CONN_F_NFCT) &&
!(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
/* Do not access conntracks during subsys cleanup
* because nf_conntrack_find_get can not be used after
* conntrack cleanup for the net.
*/
smp_rmb();
if (ipvs->enable)
ip_vs_conn_drop_conntrack(cp);
}
if (unlikely(cp->app != NULL))
ip_vs_unbind_app(cp);
ip_vs_unbind_dest(cp);
if (cp->flags & IP_VS_CONN_F_NO_CPORT)
atomic_dec(&ip_vs_conn_no_cport_cnt);
if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
ip_vs_conn_rcu_free(&cp->rcu_head);
else
call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
atomic_dec(&ipvs->conn_count);
return;
}
expire_later:
IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
refcount_read(&cp->refcnt),
atomic_read(&cp->n_control));
refcount_inc(&cp->refcnt);
cp->timeout = 60*HZ;
if (ipvs->sync_state & IP_VS_STATE_MASTER)
ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
__ip_vs_conn_put_timer(cp);
}
/* Modify timer, so that it expires as soon as possible.
* Can be called without reference only if under RCU lock.
* We can have such chain of conns linked with ->control: DATA->CTL->TPL
* - DATA (eg. FTP) and TPL (persistence) can be present depending on setup
* - cp->timeout=0 indicates all conns from chain should be dropped but
* TPL is not dropped if in assured state
*/
void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
{
/* Using mod_timer_pending will ensure the timer is not
* modified after the final del_timer in ip_vs_conn_expire.
*/
if (timer_pending(&cp->timer) &&
time_after(cp->timer.expires, jiffies))
mod_timer_pending(&cp->timer, jiffies);
}
/*
* Create a new connection entry and hash it into the ip_vs_conn_tab
*/
struct ip_vs_conn *
ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
struct ip_vs_dest *dest, __u32 fwmark)
{
struct ip_vs_conn *cp;
struct netns_ipvs *ipvs = p->ipvs;
struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
p->protocol);
cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
if (cp == NULL) {
IP_VS_ERR_RL("%s(): no memory\n", __func__);
return NULL;
}
INIT_HLIST_NODE(&cp->c_list);
timer_setup(&cp->timer, ip_vs_conn_expire, 0);
cp->ipvs = ipvs;
cp->af = p->af;
cp->daf = dest_af;
cp->protocol = p->protocol;
ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
cp->cport = p->cport;
/* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
&cp->vaddr, p->vaddr);
cp->vport = p->vport;
ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
cp->dport = dport;
cp->flags = flags;
cp->fwmark = fwmark;
if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
ip_vs_pe_get(p->pe);
cp->pe = p->pe;
cp->pe_data = p->pe_data;
cp->pe_data_len = p->pe_data_len;
} else {
cp->pe = NULL;
cp->pe_data = NULL;
cp->pe_data_len = 0;
}
spin_lock_init(&cp->lock);
/*
* Set the entry is referenced by the current thread before hashing
* it in the table, so that other thread run ip_vs_random_dropentry
* but cannot drop this entry.
*/
refcount_set(&cp->refcnt, 1);
cp->control = NULL;
atomic_set(&cp->n_control, 0);
atomic_set(&cp->in_pkts, 0);
cp->packet_xmit = NULL;
cp->app = NULL;
cp->app_data = NULL;
/* reset struct ip_vs_seq */
cp->in_seq.delta = 0;
cp->out_seq.delta = 0;
atomic_inc(&ipvs->conn_count);
if (flags & IP_VS_CONN_F_NO_CPORT)
atomic_inc(&ip_vs_conn_no_cport_cnt);
/* Bind the connection with a destination server */
cp->dest = NULL;
ip_vs_bind_dest(cp, dest);
/* Set its state and timeout */
cp->state = 0;
cp->old_state = 0;
cp->timeout = 3*HZ;
cp->sync_endtime = jiffies & ~3UL;
/* Bind its packet transmitter */
#ifdef CONFIG_IP_VS_IPV6
if (p->af == AF_INET6)
ip_vs_bind_xmit_v6(cp);
else
#endif
ip_vs_bind_xmit(cp);
if (unlikely(pd && atomic_read(&pd->appcnt)))
ip_vs_bind_app(cp, pd->pp);
/*
* Allow conntrack to be preserved. By default, conntrack
* is created and destroyed for every packet.
* Sometimes keeping conntrack can be useful for
* IP_VS_CONN_F_ONE_PACKET too.
*/
if (ip_vs_conntrack_enabled(ipvs))
cp->flags |= IP_VS_CONN_F_NFCT;
/* Hash it in the ip_vs_conn_tab finally */
ip_vs_conn_hash(cp);
return cp;
}
/*
* /proc/net/ip_vs_conn entries
*/
#ifdef CONFIG_PROC_FS
struct ip_vs_iter_state {
struct seq_net_private p;
struct hlist_head *l;
};
static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
{
int idx;
struct ip_vs_conn *cp;
struct ip_vs_iter_state *iter = seq->private;
for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
/* __ip_vs_conn_get() is not needed by
* ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
*/
if (pos-- == 0) {
iter->l = &ip_vs_conn_tab[idx];
return cp;
}
}
cond_resched_rcu();
}
return NULL;
}
static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(RCU)
{
struct ip_vs_iter_state *iter = seq->private;
iter->l = NULL;
rcu_read_lock();
return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
}
static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ip_vs_conn *cp = v;
struct ip_vs_iter_state *iter = seq->private;
struct hlist_node *e;
struct hlist_head *l = iter->l;
int idx;
++*pos;
if (v == SEQ_START_TOKEN)
return ip_vs_conn_array(seq, 0);
/* more on same hash chain? */
e = rcu_dereference(hlist_next_rcu(&cp->c_list));
if (e)
return hlist_entry(e, struct ip_vs_conn, c_list);
idx = l - ip_vs_conn_tab;
while (++idx < ip_vs_conn_tab_size) {
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
iter->l = &ip_vs_conn_tab[idx];
return cp;
}
cond_resched_rcu();
}
iter->l = NULL;
return NULL;
}
static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
__releases(RCU)
{
rcu_read_unlock();
}
static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_puts(seq,
"Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires PEName PEData\n");
else {
const struct ip_vs_conn *cp = v;
struct net *net = seq_file_net(seq);
char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
size_t len = 0;
char dbuf[IP_VS_ADDRSTRLEN];
if (!net_eq(cp->ipvs->net, net))
return 0;
if (cp->pe_data) {
pe_data[0] = ' ';
len = strlen(cp->pe->name);
memcpy(pe_data + 1, cp->pe->name, len);
pe_data[len + 1] = ' ';
len += 2;
len += cp->pe->show_pe_data(cp, pe_data + len);
}
pe_data[len] = '\0';
#ifdef CONFIG_IP_VS_IPV6
if (cp->daf == AF_INET6)
snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
else
#endif
snprintf(dbuf, sizeof(dbuf), "%08X",
ntohl(cp->daddr.ip));
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
"%s %04X %-11s %7u%s\n",
ip_vs_proto_name(cp->protocol),
&cp->caddr.in6, ntohs(cp->cport),
&cp->vaddr.in6, ntohs(cp->vport),
dbuf, ntohs(cp->dport),
ip_vs_state_name(cp),
jiffies_delta_to_msecs(cp->timer.expires -
jiffies) / 1000,
pe_data);
else
#endif
seq_printf(seq,
"%-3s %08X %04X %08X %04X"
" %s %04X %-11s %7u%s\n",
ip_vs_proto_name(cp->protocol),
ntohl(cp->caddr.ip), ntohs(cp->cport),
ntohl(cp->vaddr.ip), ntohs(cp->vport),
dbuf, ntohs(cp->dport),
ip_vs_state_name(cp),
jiffies_delta_to_msecs(cp->timer.expires -
jiffies) / 1000,
pe_data);
}
return 0;
}
static const struct seq_operations ip_vs_conn_seq_ops = {
.start = ip_vs_conn_seq_start,
.next = ip_vs_conn_seq_next,
.stop = ip_vs_conn_seq_stop,
.show = ip_vs_conn_seq_show,
};
static const char *ip_vs_origin_name(unsigned int flags)
{
if (flags & IP_VS_CONN_F_SYNC)
return "SYNC";
else
return "LOCAL";
}
static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
{
char dbuf[IP_VS_ADDRSTRLEN];
if (v == SEQ_START_TOKEN)
seq_puts(seq,
"Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n");
else {
const struct ip_vs_conn *cp = v;
struct net *net = seq_file_net(seq);
if (!net_eq(cp->ipvs->net, net))
return 0;
#ifdef CONFIG_IP_VS_IPV6
if (cp->daf == AF_INET6)
snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
else
#endif
snprintf(dbuf, sizeof(dbuf), "%08X",
ntohl(cp->daddr.ip));
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
"%s %04X %-11s %-6s %7u\n",
ip_vs_proto_name(cp->protocol),
&cp->caddr.in6, ntohs(cp->cport),
&cp->vaddr.in6, ntohs(cp->vport),
dbuf, ntohs(cp->dport),
ip_vs_state_name(cp),
ip_vs_origin_name(cp->flags),
jiffies_delta_to_msecs(cp->timer.expires -
jiffies) / 1000);
else
#endif
seq_printf(seq,
"%-3s %08X %04X %08X %04X "
"%s %04X %-11s %-6s %7u\n",
ip_vs_proto_name(cp->protocol),
ntohl(cp->caddr.ip), ntohs(cp->cport),
ntohl(cp->vaddr.ip), ntohs(cp->vport),
dbuf, ntohs(cp->dport),
ip_vs_state_name(cp),
ip_vs_origin_name(cp->flags),
jiffies_delta_to_msecs(cp->timer.expires -
jiffies) / 1000);
}
return 0;
}
static const struct seq_operations ip_vs_conn_sync_seq_ops = {
.start = ip_vs_conn_seq_start,
.next = ip_vs_conn_seq_next,
.stop = ip_vs_conn_seq_stop,
.show = ip_vs_conn_sync_seq_show,
};
#endif
/* Randomly drop connection entries before running out of memory
* Can be used for DATA and CTL conns. For TPL conns there are exceptions:
* - traffic for services in OPS mode increases ct->in_pkts, so it is supported
* - traffic for services not in OPS mode does not increase ct->in_pkts in
* all cases, so it is not supported
*/
static inline int todrop_entry(struct ip_vs_conn *cp)
{
/*
* The drop rate array needs tuning for real environments.
* Called from timer bh only => no locking
*/
static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
static char todrop_counter[9] = {0};
int i;
/* if the conn entry hasn't lasted for 60 seconds, don't drop it.
This will leave enough time for normal connection to get
through. */
if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
return 0;
/* Don't drop the entry if its number of incoming packets is not
located in [0, 8] */
i = atomic_read(&cp->in_pkts);
if (i > 8 || i < 0) return 0;
if (!todrop_rate[i]) return 0;
if (--todrop_counter[i] > 0) return 0;
todrop_counter[i] = todrop_rate[i];
return 1;
}
static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
{
struct ip_vs_service *svc;
if (!cp->dest)
return false;
svc = rcu_dereference(cp->dest->svc);
return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
}
/* Called from keventd and must protect itself from softirqs */
void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
{
int idx;
struct ip_vs_conn *cp;
rcu_read_lock();
/*
* Randomly scan 1/32 of the whole table every second
*/
for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
if (cp->ipvs != ipvs)
continue;
if (atomic_read(&cp->n_control))
continue;
if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
/* connection template of OPS */
if (ip_vs_conn_ops_mode(cp))
goto try_drop;
if (!(cp->state & IP_VS_CTPL_S_ASSURED))
goto drop;
continue;
}
if (cp->protocol == IPPROTO_TCP) {
switch(cp->state) {
case IP_VS_TCP_S_SYN_RECV:
case IP_VS_TCP_S_SYNACK:
break;
case IP_VS_TCP_S_ESTABLISHED:
if (todrop_entry(cp))
break;
continue;
default:
continue;
}
} else if (cp->protocol == IPPROTO_SCTP) {
switch (cp->state) {
case IP_VS_SCTP_S_INIT1:
case IP_VS_SCTP_S_INIT:
break;
case IP_VS_SCTP_S_ESTABLISHED:
if (todrop_entry(cp))
break;
continue;
default:
continue;
}
} else {
try_drop:
if (!todrop_entry(cp))
continue;
}
drop:
IP_VS_DBG(4, "drop connection\n");
cp->timeout = 0;
ip_vs_conn_expire_now(cp);
}
cond_resched_rcu();
}
rcu_read_unlock();
}
/*
* Flush all the connection entries in the ip_vs_conn_tab
*/
static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
{
int idx;
struct ip_vs_conn *cp, *cp_c;
flush_again:
rcu_read_lock();
for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
if (cp->ipvs != ipvs)
continue;
/* As timers are expired in LIFO order, restart
* the timer of controlling connection first, so
* that it is expired after us.
*/
cp_c = cp->control;
/* cp->control is valid only with reference to cp */
if (cp_c && __ip_vs_conn_get(cp)) {
IP_VS_DBG(4, "del controlling connection\n");
ip_vs_conn_expire_now(cp_c);
__ip_vs_conn_put(cp);
}
IP_VS_DBG(4, "del connection\n");
ip_vs_conn_expire_now(cp);
}
cond_resched_rcu();
}
rcu_read_unlock();
/* the counter may be not NULL, because maybe some conn entries
are run by slow timer handler or unhashed but still referred */
if (atomic_read(&ipvs->conn_count) != 0) {
schedule();
goto flush_again;
}
}
/*
* per netns init and exit
*/
int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
{
atomic_set(&ipvs->conn_count, 0);
proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
&ip_vs_conn_seq_ops, sizeof(struct ip_vs_iter_state));
proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
&ip_vs_conn_sync_seq_ops,
sizeof(struct ip_vs_iter_state));
return 0;
}
void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
{
/* flush all the connection entries first */
ip_vs_conn_flush(ipvs);
remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
}
int __init ip_vs_conn_init(void)
{
int idx;
/* Compute size and mask */
ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
/*
* Allocate the connection hash table and initialize its list heads
*/
ip_vs_conn_tab = vmalloc(array_size(ip_vs_conn_tab_size,
sizeof(*ip_vs_conn_tab)));
if (!ip_vs_conn_tab)
return -ENOMEM;
/* Allocate ip_vs_conn slab cache */
ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
sizeof(struct ip_vs_conn), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!ip_vs_conn_cachep) {
vfree(ip_vs_conn_tab);
return -ENOMEM;
}
pr_info("Connection hash table configured "
"(size=%d, memory=%ldKbytes)\n",
ip_vs_conn_tab_size,
(long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
IP_VS_DBG(0, "Each connection entry needs %zd bytes at least\n",
sizeof(struct ip_vs_conn));
for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) {
spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
}
/* calculate the random value for connection hash */
get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
return 0;
}
void ip_vs_conn_cleanup(void)
{
/* Wait all ip_vs_conn_rcu_free() callbacks to complete */
rcu_barrier();
/* Release the empty cache */
kmem_cache_destroy(ip_vs_conn_cachep);
vfree(ip_vs_conn_tab);
}