From: Florian Westphal <fw@xxxxxxxxx>
This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).
When event delivery fails, re-delivery is attempted via work queue.
Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.
The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.
Joint work with Pablo Neira Ayuso.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_conntrack_ecache.h | 26 +++++++-
include/net/netns/conntrack.h | 6 +-
net/netfilter/nf_conntrack_core.c | 68 +++----------------
net/netfilter/nf_conntrack_ecache.c | 96 ++++++++++++++++++++++++---
4 files changed, 124 insertions(+), 72 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h
index 0e3d08e..57c8803 100644
--- a/include/net/netfilter/nf_conntrack_ecache.h
+++ b/include/net/netfilter/nf_conntrack_ecache.h
@@ -18,7 +18,6 @@ struct nf_conntrack_ecache {
u16 ctmask; /* bitmask of ct events to be delivered */
u16 expmask; /* bitmask of expect events to be delivered */
u32 portid; /* netlink portid of destroyer */
- struct timer_list timeout;
};
static inline struct nf_conntrack_ecache *
@@ -216,8 +215,23 @@ void nf_conntrack_ecache_pernet_fini(struct net *net);
int nf_conntrack_ecache_init(void);
void nf_conntrack_ecache_fini(void);
-#else /* CONFIG_NF_CONNTRACK_EVENTS */
+static inline void nf_conntrack_ecache_delayed_work(struct net *net)
+{
+ if (!delayed_work_pending(&net->ct.ecache_dwork)) {
+ schedule_delayed_work(&net->ct.ecache_dwork, HZ);
+ net->ct.ecache_dwork_pending = true;
+ }
+}
+
+static inline void nf_conntrack_ecache_work(struct net *net)
+{
+ if (net->ct.ecache_dwork_pending) {
+ net->ct.ecache_dwork_pending = false;
+ mod_delayed_work(system_wq, &net->ct.ecache_dwork, 0);
+ }
+}
+#else /* CONFIG_NF_CONNTRACK_EVENTS */
static inline void nf_conntrack_event_cache(enum ip_conntrack_events event,
struct nf_conn *ct) {}
static inline int nf_conntrack_eventmask_report(unsigned int eventmask,
@@ -255,6 +269,14 @@ static inline int nf_conntrack_ecache_init(void)
static inline void nf_conntrack_ecache_fini(void)
{
}
+
+static inline void nf_conntrack_ecache_delayed_work(struct net *net)
+{
+}
+
+static inline void nf_conntrack_ecache_work(struct net *net)
+{
+}
#endif /* CONFIG_NF_CONNTRACK_EVENTS */
#endif /*_NF_CONNTRACK_ECACHE_H*/
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index 773cce3..29d6a94 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -4,6 +4,7 @@
#include <linux/list.h>
#include <linux/list_nulls.h>
#include <linux/atomic.h>
+#include <linux/workqueue.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/seqlock.h>
@@ -73,6 +74,10 @@ struct ct_pcpu {
struct netns_ct {
atomic_t count;
unsigned int expect_count;
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+ struct delayed_work ecache_dwork;
+ bool ecache_dwork_pending;
+#endif
#ifdef CONFIG_SYSCTL
struct ctl_table_header *sysctl_header;
struct ctl_table_header *acct_sysctl_header;
@@ -82,7 +87,6 @@ struct netns_ct {
#endif
char *slabname;
unsigned int sysctl_log_invalid; /* Log invalid packets */
- unsigned int sysctl_events_retry_timeout;
int sysctl_events;
int sysctl_acct;
int sysctl_auto_assign_helper;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 1f4f954..de88c4a 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -352,40 +352,6 @@ static void nf_ct_delete_from_lists(struct nf_conn *ct)
local_bh_enable();
}
-static void death_by_event(unsigned long ul_conntrack)
-{
- struct nf_conn *ct = (void *)ul_conntrack;
- struct net *net = nf_ct_net(ct);
- struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
-
- BUG_ON(ecache == NULL);
-
- if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
- /* bad luck, let's retry again */
- ecache->timeout.expires = jiffies +
- (prandom_u32() % net->ct.sysctl_events_retry_timeout);
- add_timer(&ecache->timeout);
- return;
- }
- /* we've got the event delivered, now it's dying */
- set_bit(IPS_DYING_BIT, &ct->status);
- nf_ct_put(ct);
-}
-
-static void nf_ct_dying_timeout(struct nf_conn *ct)
-{
- struct net *net = nf_ct_net(ct);
- struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
-
- BUG_ON(ecache == NULL);
-
- /* set a new timer to retry event delivery */
- setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
- ecache->timeout.expires = jiffies +
- (prandom_u32() % net->ct.sysctl_events_retry_timeout);
- add_timer(&ecache->timeout);
-}
-
bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
{
struct nf_conn_tstamp *tstamp;
@@ -394,15 +360,20 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
if (tstamp && tstamp->stop == 0)
tstamp->stop = ktime_to_ns(ktime_get_real());
- if (!nf_ct_is_dying(ct) &&
- unlikely(nf_conntrack_event_report(IPCT_DESTROY, ct,
- portid, report) < 0)) {
+ if (nf_ct_is_dying(ct))
+ goto delete;
+
+ if (nf_conntrack_event_report(IPCT_DESTROY, ct,
+ portid, report) < 0) {
/* destroy event was not delivered */
nf_ct_delete_from_lists(ct);
- nf_ct_dying_timeout(ct);
+ nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
return false;
}
+
+ nf_conntrack_ecache_work(nf_ct_net(ct));
set_bit(IPS_DYING_BIT, &ct->status);
+ delete:
nf_ct_delete_from_lists(ct);
nf_ct_put(ct);
return true;
@@ -1464,26 +1435,6 @@ void nf_conntrack_flush_report(struct net *net, u32 portid, int report)
}
EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
-static void nf_ct_release_dying_list(struct net *net)
-{
- struct nf_conntrack_tuple_hash *h;
- struct nf_conn *ct;
- struct hlist_nulls_node *n;
- int cpu;
-
- for_each_possible_cpu(cpu) {
- struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
-
- spin_lock_bh(&pcpu->lock);
- hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) {
- ct = nf_ct_tuplehash_to_ctrack(h);
- /* never fails to remove them, no listeners at this point */
- nf_ct_kill(ct);
- }
- spin_unlock_bh(&pcpu->lock);
- }
-}
-
static int untrack_refs(void)
{
int cnt = 0, cpu;
@@ -1548,7 +1499,6 @@ i_see_dead_people:
busy = 0;
list_for_each_entry(net, net_exit_list, exit_list) {
nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
- nf_ct_release_dying_list(net);
if (atomic_read(&net->ct.count) != 0)
busy = 1;
}
diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
index 1df1761..4e78c57 100644
--- a/net/netfilter/nf_conntrack_ecache.c
+++ b/net/netfilter/nf_conntrack_ecache.c
@@ -29,6 +29,90 @@
static DEFINE_MUTEX(nf_ct_ecache_mutex);
+#define ECACHE_RETRY_WAIT (HZ/10)
+
+enum retry_state {
+ STATE_CONGESTED,
+ STATE_RESTART,
+ STATE_DONE,
+};
+
+static enum retry_state ecache_work_evict_list(struct ct_pcpu *pcpu)
+{
+ struct nf_conn *refs[16];
+ struct nf_conntrack_tuple_hash *h;
+ struct hlist_nulls_node *n;
+ unsigned int evicted = 0;
+ enum retry_state ret = STATE_DONE;
+
+ spin_lock(&pcpu->lock);
+
+ hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) {
+ struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
+ if (nf_ct_is_dying(ct))
+ continue;
+
+ if (nf_conntrack_event(IPCT_DESTROY, ct)) {
+ ret = STATE_CONGESTED;
+ break;
+ }
+
+ /* we've got the event delivered, now it's dying */
+ set_bit(IPS_DYING_BIT, &ct->status);
+ refs[evicted] = ct;
+
+ if (++evicted >= ARRAY_SIZE(refs)) {
+ ret = STATE_RESTART;
+ break;
+ }
+ }
+
+ spin_unlock(&pcpu->lock);
+
+ /* can't _put while holding lock */
+ while (evicted)
+ nf_ct_put(refs[--evicted]);
+
+ return ret;
+}
+
+static void ecache_work(struct work_struct *work)
+{
+ struct netns_ct *ctnet =
+ container_of(work, struct netns_ct, ecache_dwork.work);
+ int cpu, delay = -1;
+ struct ct_pcpu *pcpu;
+
+ local_bh_disable();
+
+ for_each_possible_cpu(cpu) {
+ enum retry_state ret;
+
+ pcpu = per_cpu_ptr(ctnet->pcpu_lists, cpu);
+
+ ret = ecache_work_evict_list(pcpu);
+
+ switch (ret) {
+ case STATE_CONGESTED:
+ delay = ECACHE_RETRY_WAIT;
+ goto out;
+ case STATE_RESTART:
+ delay = 0;
+ break;
+ case STATE_DONE:
+ break;
+ }
+ }
+
+ out:
+ local_bh_enable();
+
+ ctnet->ecache_dwork_pending = delay > 0;
+ if (delay >= 0)
+ schedule_delayed_work(&ctnet->ecache_dwork, delay);
+}
+
/* deliver cached events and clear cache entry - must be called with locally
* disabled softirqs */
void nf_ct_deliver_cached_events(struct nf_conn *ct)
@@ -157,7 +241,6 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);
#define NF_CT_EVENTS_DEFAULT 1
static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT;
-static int nf_ct_events_retry_timeout __read_mostly = 15*HZ;
#ifdef CONFIG_SYSCTL
static struct ctl_table event_sysctl_table[] = {
@@ -168,13 +251,6 @@ static struct ctl_table event_sysctl_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
- {
- .procname = "nf_conntrack_events_retry_timeout",
- .data = &init_net.ct.sysctl_events_retry_timeout,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec_jiffies,
- },
{}
};
#endif /* CONFIG_SYSCTL */
@@ -196,7 +272,6 @@ static int nf_conntrack_event_init_sysctl(struct net *net)
goto out;
table[0].data = &net->ct.sysctl_events;
- table[1].data = &net->ct.sysctl_events_retry_timeout;
/* Don't export sysctls to unprivileged users */
if (net->user_ns != &init_user_ns)
@@ -238,12 +313,13 @@ static void nf_conntrack_event_fini_sysctl(struct net *net)
int nf_conntrack_ecache_pernet_init(struct net *net)
{
net->ct.sysctl_events = nf_ct_events;
- net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout;
+ INIT_DELAYED_WORK(&net->ct.ecache_dwork, ecache_work);
return nf_conntrack_event_init_sysctl(net);
}
void nf_conntrack_ecache_pernet_fini(struct net *net)
{
+ cancel_delayed_work_sync(&net->ct.ecache_dwork);
nf_conntrack_event_fini_sysctl(net);
}
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
