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ip_vs_conn.c
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ip_vs_conn.c
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// 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;
const union nf_inet_addr *saddr;
__be16 sport;
/*
* 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)
continue;
if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
sport = cp->vport;
saddr = &cp->vaddr;
} else {
sport = cp->dport;
saddr = &cp->daddr;
}
if (p->cport == sport && cp->af == p->af &&
ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
ip_vs_addr_equal(p->af, p->caddr, saddr) &&
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);
}
/* Try to delete connection while not holding reference */
static void ip_vs_conn_del(struct ip_vs_conn *cp)
{
if (del_timer(&cp->timer)) {
/* Drop cp->control chain too */
if (cp->control)
cp->timeout = 0;
ip_vs_conn_expire(&cp->timer);
}
}
/* Try to delete connection while holding reference */
static void ip_vs_conn_del_put(struct ip_vs_conn *cp)
{
if (del_timer(&cp->timer)) {
/* Drop cp->control chain too */
if (cp->control)
cp->timeout = 0;
__ip_vs_conn_put(cp);
ip_vs_conn_expire(&cp->timer);
} else {
__ip_vs_conn_put(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) {
bool has_ref = !cp->timeout && __ip_vs_conn_get(ct);
ip_vs_control_del(cp);
/* Drop CTL or non-assured TPL if not used anymore */
if (has_ref && !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");
ip_vs_conn_del_put(ct);
} else if (has_ref) {
__ip_vs_conn_put(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;