diff options
author | Arnaldo Carvalho de Melo <acme@mandriva.com> | 2005-08-09 20:45:03 -0700 |
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committer | David S. Miller <davem@sunset.davemloft.net> | 2005-08-29 15:55:58 -0700 |
commit | 696ab2d3bffc746fb8cf3712f066d42b9886aeed (patch) | |
tree | d0990b1d6f5fd6b3b7ddce553a16cccf6f029651 /net/ipv4/inet_timewait_sock.c | |
parent | 295ff7edb8f72b77d524759266f7524deae379b3 (diff) | |
download | linux-696ab2d3bffc746fb8cf3712f066d42b9886aeed.tar.bz2 |
[TIMEWAIT]: Move inet_timewait_death_row routines to net/ipv4/inet_timewait_sock.c
Also export the ones that will be used in the next changeset, when
DCCP uses this infrastructure.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/inet_timewait_sock.c')
-rw-r--r-- | net/ipv4/inet_timewait_sock.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 22882d95f646..4d1502a49852 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -12,6 +12,7 @@ #include <net/inet_hashtables.h> #include <net/inet_timewait_sock.h> +#include <net/ip.h> /* Must be called with locally disabled BHs. */ void __inet_twsk_kill(struct inet_timewait_sock *tw, struct inet_hashinfo *hashinfo) @@ -85,6 +86,8 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, write_unlock(&ehead->lock); } +EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); + struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state) { struct inet_timewait_sock *tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_slab, @@ -112,3 +115,270 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat return tw; } + +EXPORT_SYMBOL_GPL(inet_twsk_alloc); + +/* Returns non-zero if quota exceeded. */ +static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr, + const int slot) +{ + struct inet_timewait_sock *tw; + struct hlist_node *node; + unsigned int killed; + int ret; + + /* NOTE: compare this to previous version where lock + * was released after detaching chain. It was racy, + * because tw buckets are scheduled in not serialized context + * in 2.3 (with netfilter), and with softnet it is common, because + * soft irqs are not sequenced. + */ + killed = 0; + ret = 0; +rescan: + inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) { + __inet_twsk_del_dead_node(tw); + spin_unlock(&twdr->death_lock); + __inet_twsk_kill(tw, twdr->hashinfo); + inet_twsk_put(tw); + killed++; + spin_lock(&twdr->death_lock); + if (killed > INET_TWDR_TWKILL_QUOTA) { + ret = 1; + break; + } + + /* While we dropped twdr->death_lock, another cpu may have + * killed off the next TW bucket in the list, therefore + * do a fresh re-read of the hlist head node with the + * lock reacquired. We still use the hlist traversal + * macro in order to get the prefetches. + */ + goto rescan; + } + + twdr->tw_count -= killed; + NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed); + + return ret; +} + +void inet_twdr_hangman(unsigned long data) +{ + struct inet_timewait_death_row *twdr; + int unsigned need_timer; + + twdr = (struct inet_timewait_death_row *)data; + spin_lock(&twdr->death_lock); + + if (twdr->tw_count == 0) + goto out; + + need_timer = 0; + if (inet_twdr_do_twkill_work(twdr, twdr->slot)) { + twdr->thread_slots |= (1 << twdr->slot); + mb(); + schedule_work(&twdr->twkill_work); + need_timer = 1; + } else { + /* We purged the entire slot, anything left? */ + if (twdr->tw_count) + need_timer = 1; + } + twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1)); + if (need_timer) + mod_timer(&twdr->tw_timer, jiffies + twdr->period); +out: + spin_unlock(&twdr->death_lock); +} + +EXPORT_SYMBOL_GPL(inet_twdr_hangman); + +extern void twkill_slots_invalid(void); + +void inet_twdr_twkill_work(void *data) +{ + struct inet_timewait_death_row *twdr = data; + int i; + + if ((INET_TWDR_TWKILL_SLOTS - 1) > (sizeof(twdr->thread_slots) * 8)) + twkill_slots_invalid(); + + while (twdr->thread_slots) { + spin_lock_bh(&twdr->death_lock); + for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) { + if (!(twdr->thread_slots & (1 << i))) + continue; + + while (inet_twdr_do_twkill_work(twdr, i) != 0) { + if (need_resched()) { + spin_unlock_bh(&twdr->death_lock); + schedule(); + spin_lock_bh(&twdr->death_lock); + } + } + + twdr->thread_slots &= ~(1 << i); + } + spin_unlock_bh(&twdr->death_lock); + } +} + +EXPORT_SYMBOL_GPL(inet_twdr_twkill_work); + +/* 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. */ +void inet_twsk_deschedule(struct inet_timewait_sock *tw, + struct inet_timewait_death_row *twdr) +{ + spin_lock(&twdr->death_lock); + if (inet_twsk_del_dead_node(tw)) { + inet_twsk_put(tw); + if (--twdr->tw_count == 0) + del_timer(&twdr->tw_timer); + } + spin_unlock(&twdr->death_lock); + __inet_twsk_kill(tw, twdr->hashinfo); +} + +EXPORT_SYMBOL(inet_twsk_deschedule); + +void inet_twsk_schedule(struct inet_timewait_sock *tw, + struct inet_timewait_death_row *twdr, + const int timeo, const int timewait_len) +{ + struct hlist_head *list; + int slot; + + /* 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. + */ + slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK; + + spin_lock(&twdr->death_lock); + + /* Unlink it, if it was scheduled */ + if (inet_twsk_del_dead_node(tw)) + twdr->tw_count--; + else + atomic_inc(&tw->tw_refcnt); + + if (slot >= INET_TWDR_RECYCLE_SLOTS) { + /* Schedule to slow timer */ + if (timeo >= timewait_len) { + slot = INET_TWDR_TWKILL_SLOTS - 1; + } else { + slot = (timeo + twdr->period - 1) / twdr->period; + if (slot >= INET_TWDR_TWKILL_SLOTS) + slot = INET_TWDR_TWKILL_SLOTS - 1; + } + tw->tw_ttd = jiffies + timeo; + slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1); + list = &twdr->cells[slot]; + } else { + tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK); + + if (twdr->twcal_hand < 0) { + twdr->twcal_hand = 0; + twdr->twcal_jiffie = jiffies; + twdr->twcal_timer.expires = twdr->twcal_jiffie + + (slot << INET_TWDR_RECYCLE_TICK); + add_timer(&twdr->twcal_timer); + } else { + if (time_after(twdr->twcal_timer.expires, + jiffies + (slot << INET_TWDR_RECYCLE_TICK))) + mod_timer(&twdr->twcal_timer, + jiffies + (slot << INET_TWDR_RECYCLE_TICK)); + slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1); + } + list = &twdr->twcal_row[slot]; + } + + hlist_add_head(&tw->tw_death_node, list); + + if (twdr->tw_count++ == 0) + mod_timer(&twdr->tw_timer, jiffies + twdr->period); + spin_unlock(&twdr->death_lock); +} + +EXPORT_SYMBOL_GPL(inet_twsk_schedule); + +void inet_twdr_twcal_tick(unsigned long data) +{ + struct inet_timewait_death_row *twdr; + int n, slot; + unsigned long j; + unsigned long now = jiffies; + int killed = 0; + int adv = 0; + + twdr = (struct inet_timewait_death_row *)data; + + spin_lock(&twdr->death_lock); + if (twdr->twcal_hand < 0) + goto out; + + slot = twdr->twcal_hand; + j = twdr->twcal_jiffie; + + for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) { + if (time_before_eq(j, now)) { + struct hlist_node *node, *safe; + struct inet_timewait_sock *tw; + + inet_twsk_for_each_inmate_safe(tw, node, safe, + &twdr->twcal_row[slot]) { + __inet_twsk_del_dead_node(tw); + __inet_twsk_kill(tw, twdr->hashinfo); + inet_twsk_put(tw); + killed++; + } + } else { + if (!adv) { + adv = 1; + twdr->twcal_jiffie = j; + twdr->twcal_hand = slot; + } + + if (!hlist_empty(&twdr->twcal_row[slot])) { + mod_timer(&twdr->twcal_timer, j); + goto out; + } + } + j += 1 << INET_TWDR_RECYCLE_TICK; + slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1); + } + twdr->twcal_hand = -1; + +out: + if ((twdr->tw_count -= killed) == 0) + del_timer(&twdr->tw_timer); + NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed); + spin_unlock(&twdr->death_lock); +} + +EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick); |