mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 05:34:00 +08:00
f3438bc781
Pinned timers must carry the pinned attribute in the timer structure itself, so convert the code to the new API. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094341.617891430@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
307 lines
8.9 KiB
C
307 lines
8.9 KiB
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);
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
void inet_twsk_put(struct inet_timewait_sock *tw)
|
|
{
|
|
if (atomic_dec_and_test(&tw->tw_refcnt))
|
|
inet_twsk_free(tw);
|
|
}
|
|
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);
|
|
}
|
|
|
|
static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
|
|
struct hlist_head *list)
|
|
{
|
|
hlist_add_head(&tw->tw_bind_node, list);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
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);
|
|
}
|
|
|
|
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;
|
|
}
|
|
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);
|
|
}
|
|
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);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(__inet_twsk_schedule);
|
|
|
|
void inet_twsk_purge(struct inet_hashinfo *hashinfo,
|
|
struct inet_timewait_death_row *twdr, 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();
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_twsk_purge);
|