Release 4.11 net/ipv4/inet_timewait_sock.c
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Generic TIME_WAIT sockets functions
*
* From code orinally in TCP
*/
#include <linux/kernel.h>
#include <linux/kmemcheck.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <net/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/ip.h>
/**
* inet_twsk_bind_unhash - unhash a timewait socket from bind hash
* @tw: timewait socket
* @hashinfo: hashinfo pointer
*
* unhash a timewait socket from bind hash, if hashed.
* bind hash lock must be held by caller.
* Returns 1 if caller should call inet_twsk_put() after lock release.
*/
void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
struct inet_hashinfo *hashinfo)
{
struct inet_bind_bucket *tb = tw->tw_tb;
if (!tb)
return;
__hlist_del(&tw->tw_bind_node);
tw->tw_tb = NULL;
inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
__sock_put((struct sock *)tw);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 63 | 100.00% | 2 | 100.00% |
| Total | 63 | 100.00% | 2 | 100.00% |
/* Must be called with locally disabled BHs. */
static void inet_twsk_kill(struct inet_timewait_sock *tw)
{
struct inet_hashinfo *hashinfo = tw->tw_dr->hashinfo;
spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
struct inet_bind_hashbucket *bhead;
spin_lock(lock);
sk_nulls_del_node_init_rcu((struct sock *)tw);
spin_unlock(lock);
/* Disassociate with bind bucket. */
bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num,
hashinfo->bhash_size)];
spin_lock(&bhead->lock);
inet_twsk_bind_unhash(tw, hashinfo);
spin_unlock(&bhead->lock);
atomic_dec(&tw->tw_dr->tw_count);
inet_twsk_put(tw);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Arnaldo Carvalho de Melo | 70 | 56.91% | 1 | 11.11% |
| Eric Dumazet | 47 | 38.21% | 6 | 66.67% |
| Pavel Emelyanov | 5 | 4.07% | 1 | 11.11% |
| Adrian Bunk | 1 | 0.81% | 1 | 11.11% |
| Total | 123 | 100.00% | 9 | 100.00% |
void inet_twsk_free(struct inet_timewait_sock *tw)
{
struct module *owner = tw->tw_prot->owner;
twsk_destructor((struct sock *)tw);
#ifdef SOCK_REFCNT_DEBUG
pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);
#endif
kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
module_put(owner);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Pavel Emelyanov | 65 | 97.01% | 1 | 50.00% |
| Arnaldo Carvalho de Melo | 2 | 2.99% | 1 | 50.00% |
| Total | 67 | 100.00% | 2 | 100.00% |
void inet_twsk_put(struct inet_timewait_sock *tw)
{
if (atomic_dec_and_test(&tw->tw_refcnt))
inet_twsk_free(tw);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Arnaldo Carvalho de Melo | 24 | 96.00% | 1 | 50.00% |
| Pavel Emelyanov | 1 | 4.00% | 1 | 50.00% |
| Total | 25 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL_GPL(inet_twsk_put);
static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
struct hlist_nulls_head *list)
{
hlist_nulls_add_head_rcu(&tw->tw_node, list);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 26 | 100.00% | 1 | 100.00% |
| Total | 26 | 100.00% | 1 | 100.00% |
static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
struct hlist_head *list)
{
hlist_add_head(&tw->tw_bind_node, list);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 26 | 100.00% | 1 | 100.00% |
| Total | 26 | 100.00% | 1 | 100.00% |
/*
* Enter the time wait state.
* Essentially we whip up a timewait bucket, copy the relevant info into it
* from the SK, and mess with hash chains and list linkage.
*/
void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
struct inet_hashinfo *hashinfo)
{
const struct inet_sock *inet = inet_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash);
spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
struct inet_bind_hashbucket *bhead;
/* Step 1: Put TW into bind hash. Original socket stays there too.
Note, that any socket with inet->num != 0 MUST be bound in
binding cache, even if it is closed.
*/
bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num,
hashinfo->bhash_size)];
spin_lock_bh(&bhead->lock);
tw->tw_tb = icsk->icsk_bind_hash;
WARN_ON(!icsk->icsk_bind_hash);
inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
spin_unlock(&bhead->lock);
spin_lock(lock);
/*
* Step 2: Hash TW into tcp ehash chain.
* Notes :
* - tw_refcnt is set to 4 because :
* - We have one reference from bhash chain.
* - We have one reference from ehash chain.
* - We have one reference from timer.
* - One reference for ourself (our caller will release it).
* We can use atomic_set() because prior spin_lock()/spin_unlock()
* committed into memory all tw fields.
*/
atomic_set(&tw->tw_refcnt, 4);
inet_twsk_add_node_rcu(tw, &ehead->chain);
/* Step 3: Remove SK from hash chain */
if (__sk_nulls_del_node_init_rcu(sk))
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
spin_unlock_bh(lock);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Arnaldo Carvalho de Melo | 136 | 69.04% | 2 | 14.29% |
| Eric Dumazet | 49 | 24.87% | 9 | 64.29% |
| Pavel Emelyanov | 10 | 5.08% | 2 | 14.29% |
| Ilpo Järvinen | 2 | 1.02% | 1 | 7.14% |
| Total | 197 | 100.00% | 14 | 100.00% |
EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
static void tw_timer_handler(unsigned long data)
{
struct inet_timewait_sock *tw = (struct inet_timewait_sock *)data;
if (tw->tw_kill)
__NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED);
else
__NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITED);
inet_twsk_kill(tw);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 54 | 100.00% | 3 | 100.00% |
| Total | 54 | 100.00% | 3 | 100.00% |
struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
struct inet_timewait_death_row *dr,
const int state)
{
struct inet_timewait_sock *tw;
if (atomic_read(&dr->tw_count) >= dr->sysctl_max_tw_buckets)
return NULL;
tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
GFP_ATOMIC);
if (tw) {
const struct inet_sock *inet = inet_sk(sk);
kmemcheck_annotate_bitfield(tw, flags);
tw->tw_dr = dr;
/* Give us an identity. */
tw->tw_daddr = inet->inet_daddr;
tw->tw_rcv_saddr = inet->inet_rcv_saddr;
tw->tw_bound_dev_if = sk->sk_bound_dev_if;
tw->tw_tos = inet->tos;
tw->tw_num = inet->inet_num;
tw->tw_state = TCP_TIME_WAIT;
tw->tw_substate = state;
tw->tw_sport = inet->inet_sport;
tw->tw_dport = inet->inet_dport;
tw->tw_family = sk->sk_family;
tw->tw_reuse = sk->sk_reuse;
tw->tw_hash = sk->sk_hash;
tw->tw_ipv6only = 0;
tw->tw_transparent = inet->transparent;
tw->tw_prot = sk->sk_prot_creator;
atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie));
twsk_net_set(tw, sock_net(sk));
setup_pinned_timer(&tw->tw_timer, tw_timer_handler,
(unsigned long)tw);
/*
* Because we use RCU lookups, we should not set tw_refcnt
* to a non null value before everything is setup for this
* timewait socket.
*/
atomic_set(&tw->tw_refcnt, 0);
__module_get(tw->tw_prot->owner);
}
return tw;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Arnaldo Carvalho de Melo | 164 | 60.97% | 3 | 21.43% |
| Eric Dumazet | 78 | 29.00% | 5 | 35.71% |
| KOVACS Krisztian | 8 | 2.97% | 1 | 7.14% |
| Vegard Nossum | 7 | 2.60% | 1 | 7.14% |
| Hideaki Yoshifuji / 吉藤英明 | 7 | 2.60% | 1 | 7.14% |
| Daniel Lezcano | 3 | 1.12% | 1 | 7.14% |
| Christoph Lameter | 1 | 0.37% | 1 | 7.14% |
| Thomas Gleixner | 1 | 0.37% | 1 | 7.14% |
| Total | 269 | 100.00% | 14 | 100.00% |
EXPORT_SYMBOL_GPL(inet_twsk_alloc);
/* These are always called from BH context. See callers in
* tcp_input.c to verify this.
*/
/* This is for handling early-kills of TIME_WAIT sockets.
* Warning : consume reference.
* Caller should not access tw anymore.
*/
void inet_twsk_deschedule_put(struct inet_timewait_sock *tw)
{
if (del_timer_sync(&tw->tw_timer))
inet_twsk_kill(tw);
inet_twsk_put(tw);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 19 | 63.33% | 2 | 66.67% |
| Arnaldo Carvalho de Melo | 11 | 36.67% | 1 | 33.33% |
| Total | 30 | 100.00% | 3 | 100.00% |
EXPORT_SYMBOL(inet_twsk_deschedule_put);
void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm)
{
/* timeout := RTO * 3.5
*
* 3.5 = 1+2+0.5 to wait for two retransmits.
*
* RATIONALE: if FIN arrived and we entered TIME-WAIT state,
* our ACK acking that FIN can be lost. If N subsequent retransmitted
* FINs (or previous seqments) are lost (probability of such event
* is p^(N+1), where p is probability to lose single packet and
* time to detect the loss is about RTO*(2^N - 1) with exponential
* backoff). Normal timewait length is calculated so, that we
* waited at least for one retransmitted FIN (maximal RTO is 120sec).
* [ BTW Linux. following BSD, violates this requirement waiting
* only for 60sec, we should wait at least for 240 secs.
* Well, 240 consumes too much of resources 8)
* ]
* This interval is not reduced to catch old duplicate and
* responces to our wandering segments living for two MSLs.
* However, if we use PAWS to detect
* old duplicates, we can reduce the interval to bounds required
* by RTO, rather than MSL. So, if peer understands PAWS, we
* kill tw bucket after 3.5*RTO (it is important that this number
* is greater than TS tick!) and detect old duplicates with help
* of PAWS.
*/
tw->tw_kill = timeo <= 4*HZ;
if (!rearm) {
BUG_ON(mod_timer(&tw->tw_timer, jiffies + timeo));
atomic_inc(&tw->tw_dr->tw_count);
} else {
mod_timer_pending(&tw->tw_timer, jiffies + timeo);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 56 | 75.68% | 2 | 40.00% |
| Arnaldo Carvalho de Melo | 13 | 17.57% | 1 | 20.00% |
| Pavel Emelyanov | 4 | 5.41% | 1 | 20.00% |
| Thomas Gleixner | 1 | 1.35% | 1 | 20.00% |
| Total | 74 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL_GPL(__inet_twsk_schedule);
void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family)
{
struct inet_timewait_sock *tw;
struct sock *sk;
struct hlist_nulls_node *node;
unsigned int slot;
for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {
struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
restart_rcu:
cond_resched();
rcu_read_lock();
restart:
sk_nulls_for_each_rcu(sk, node, &head->chain) {
if (sk->sk_state != TCP_TIME_WAIT)
continue;
tw = inet_twsk(sk);
if ((tw->tw_family != family) ||
atomic_read(&twsk_net(tw)->count))
continue;
if (unlikely(!atomic_inc_not_zero(&tw->tw_refcnt)))
continue;
if (unlikely((tw->tw_family != family) ||
atomic_read(&twsk_net(tw)->count))) {
inet_twsk_put(tw);
goto restart;
}
rcu_read_unlock();
local_bh_disable();
inet_twsk_deschedule_put(tw);
local_bh_enable();
goto restart_rcu;
}
/* If the nulls value we got at the end of this lookup is
* not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(node) != slot)
goto restart;
rcu_read_unlock();
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Daniel Lezcano | 93 | 46.04% | 1 | 11.11% |
| Eric W. Biedermann | 86 | 42.57% | 2 | 22.22% |
| Eric Dumazet | 23 | 11.39% | 6 | 66.67% |
| Total | 202 | 100.00% | 9 | 100.00% |
EXPORT_SYMBOL_GPL(inet_twsk_purge);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Eric Dumazet | 449 | 37.02% | 21 | 45.65% |
| Arnaldo Carvalho de Melo | 447 | 36.85% | 7 | 15.22% |
| Daniel Lezcano | 101 | 8.33% | 2 | 4.35% |
| Pavel Emelyanov | 90 | 7.42% | 4 | 8.70% |
| Eric W. Biedermann | 86 | 7.09% | 2 | 4.35% |
| Vegard Nossum | 10 | 0.82% | 1 | 2.17% |
| KOVACS Krisztian | 8 | 0.66% | 1 | 2.17% |
| Hideaki Yoshifuji / 吉藤英明 | 7 | 0.58% | 1 | 2.17% |
| Ilpo Järvinen | 5 | 0.41% | 2 | 4.35% |
| Paul Gortmaker | 3 | 0.25% | 1 | 2.17% |
| Tejun Heo | 3 | 0.25% | 1 | 2.17% |
| Thomas Gleixner | 2 | 0.16% | 1 | 2.17% |
| Christoph Lameter | 1 | 0.08% | 1 | 2.17% |
| Adrian Bunk | 1 | 0.08% | 1 | 2.17% |
| Total | 1213 | 100.00% | 46 | 100.00% |
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