diff options
| -rw-r--r-- | include/net/inet_timewait_sock.h | 10 | ||||
| -rw-r--r-- | include/net/tcp.h | 2 | ||||
| -rw-r--r-- | net/ipv4/inet_timewait_sock.c | 270 | ||||
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 281 |
4 files changed, 290 insertions, 273 deletions
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h index a7e8052..3b07035 100644 --- a/include/net/inet_timewait_sock.h +++ b/include/net/inet_timewait_sock.h @@ -82,6 +82,10 @@ struct inet_timewait_death_row { int sysctl_max_tw_buckets; }; +extern void inet_twdr_hangman(unsigned long data); +extern void inet_twdr_twkill_work(void *data); +extern void inet_twdr_twcal_tick(unsigned long data); + #if (BITS_PER_LONG == 64) #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8 #else @@ -206,4 +210,10 @@ extern void __inet_twsk_kill(struct inet_timewait_sock *tw, extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, struct inet_hashinfo *hashinfo); + +extern void inet_twsk_schedule(struct inet_timewait_sock *tw, + struct inet_timewait_death_row *twdr, + const int timeo, const int timewait_len); +extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, + struct inet_timewait_death_row *twdr); #endif /* _INET_TIMEWAIT_SOCK_ */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 4c4cd4f..d489ac5 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -44,8 +44,6 @@ extern struct inet_hashinfo tcp_hashinfo; extern atomic_t tcp_orphan_count; extern void tcp_time_wait(struct sock *sk, int state, int timeo); -extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, - struct inet_timewait_death_row *twdr); #define MAX_TCP_HEADER (128 + MAX_HEADER) diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 22882d9..4d1502a 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); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 81b9a52..dc08523 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -35,12 +35,6 @@ #define SYNC_INIT 1 #endif -/* New-style handling of TIME_WAIT sockets. */ - -static void inet_twdr_hangman(unsigned long data); -static void inet_twdr_twkill_work(void *data); -static void inet_twdr_twcal_tick(unsigned long data); - int sysctl_tcp_syncookies = SYNC_INIT; int sysctl_tcp_abort_on_overflow; @@ -63,10 +57,6 @@ struct inet_timewait_death_row tcp_death_row = { EXPORT_SYMBOL_GPL(tcp_death_row); -static void inet_twsk_schedule(struct inet_timewait_sock *tw, - struct inet_timewait_death_row *twdr, - const int timeo); - static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win) { if (seq == s_win) @@ -173,9 +163,11 @@ kill_with_rst: if (tw->tw_family == AF_INET && tcp_death_row.sysctl_tw_recycle && tcptw->tw_ts_recent_stamp && tcp_v4_tw_remember_stamp(tw)) - inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout); + inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout, + TCP_TIMEWAIT_LEN); else - inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN); + inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN, + TCP_TIMEWAIT_LEN); return TCP_TW_ACK; } @@ -213,7 +205,8 @@ kill: return TCP_TW_SUCCESS; } } - inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN); + inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN, + TCP_TIMEWAIT_LEN); if (tmp_opt.saw_tstamp) { tcptw->tw_ts_recent = tmp_opt.rcv_tsval; @@ -263,7 +256,8 @@ kill: * Do not reschedule in the last case. */ if (paws_reject || th->ack) - inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN); + inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN, + TCP_TIMEWAIT_LEN); /* Send ACK. Note, we do not put the bucket, * it will be released by caller. @@ -326,7 +320,8 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) timeo = TCP_TIMEWAIT_LEN; } - inet_twsk_schedule(tw, &tcp_death_row, timeo); + inet_twsk_schedule(tw, &tcp_death_row, timeo, + TCP_TIMEWAIT_LEN); inet_twsk_put(tw); } else { /* Sorry, if we're out of memory, just CLOSE this @@ -341,261 +336,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) tcp_done(sk); } -/* 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; -} - -static 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); -} - -extern void twkill_slots_invalid(void); - -static 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); - } -} - -/* 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); -} - -static void inet_twsk_schedule(struct inet_timewait_sock *tw, - struct inet_timewait_death_row *twdr, - const int timeo) -{ - 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 >= TCP_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); -} - -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); -} - /* This is not only more efficient than what we used to do, it eliminates * a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM * @@ -933,4 +673,3 @@ EXPORT_SYMBOL(tcp_check_req); EXPORT_SYMBOL(tcp_child_process); EXPORT_SYMBOL(tcp_create_openreq_child); EXPORT_SYMBOL(tcp_timewait_state_process); -EXPORT_SYMBOL(inet_twsk_deschedule); |
