diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index ecc79f9590762d9f233ae35186aa96adec14a9f8..a632689b61b40f581e4cc1d25fe65ebcac053995 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -201,6 +201,8 @@ extern struct nf_conntrack_tuple_hash * __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple); extern void nf_conntrack_hash_insert(struct nf_conn *ct); +extern void nf_ct_delete_from_lists(struct nf_conn *ct); +extern void nf_ct_insert_dying_list(struct nf_conn *ct); extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report); diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h index e7ae297ba383395f816aa8f0f7c60523e51e3270..4f20d58e2ab74a5155c89d9284eedbec6d2bd19f 100644 --- a/include/net/netfilter/nf_conntrack_ecache.h +++ b/include/net/netfilter/nf_conntrack_ecache.h @@ -32,6 +32,8 @@ enum ip_conntrack_expect_events { struct nf_conntrack_ecache { unsigned long cache; /* bitops want long */ + unsigned long missed; /* missed events */ + u32 pid; /* netlink pid of destroyer */ }; static inline struct nf_conntrack_ecache * @@ -84,14 +86,16 @@ nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct) set_bit(event, &e->cache); } -static inline void +static inline int nf_conntrack_eventmask_report(unsigned int eventmask, struct nf_conn *ct, u32 pid, int report) { + int ret = 0; struct net *net = nf_ct_net(ct); struct nf_ct_event_notifier *notify; + struct nf_conntrack_ecache *e; rcu_read_lock(); notify = rcu_dereference(nf_conntrack_event_cb); @@ -101,29 +105,52 @@ nf_conntrack_eventmask_report(unsigned int eventmask, if (!net->ct.sysctl_events) goto out_unlock; + e = nf_ct_ecache_find(ct); + if (e == NULL) + goto out_unlock; + if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) { struct nf_ct_event item = { .ct = ct, - .pid = pid, + .pid = e->pid ? e->pid : pid, .report = report }; - notify->fcn(eventmask, &item); + /* This is a resent of a destroy event? If so, skip missed */ + unsigned long missed = e->pid ? 0 : e->missed; + + ret = notify->fcn(eventmask | missed, &item); + if (unlikely(ret < 0 || missed)) { + spin_lock_bh(&ct->lock); + if (ret < 0) { + /* This is a destroy event that has been + * triggered by a process, we store the PID + * to include it in the retransmission. */ + if (eventmask & (1 << IPCT_DESTROY) && + e->pid == 0 && pid != 0) + e->pid = pid; + else + e->missed |= eventmask; + } else + e->missed &= ~missed; + spin_unlock_bh(&ct->lock); + } } out_unlock: rcu_read_unlock(); + return ret; } -static inline void +static inline int nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct, u32 pid, int report) { - nf_conntrack_eventmask_report(1 << event, ct, pid, report); + return nf_conntrack_eventmask_report(1 << event, ct, pid, report); } -static inline void +static inline int nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct) { - nf_conntrack_eventmask_report(1 << event, ct, 0, 0); + return nf_conntrack_eventmask_report(1 << event, ct, 0, 0); } struct nf_exp_event { @@ -183,16 +210,16 @@ extern void nf_conntrack_ecache_fini(struct net *net); static inline void nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct) {} -static inline void nf_conntrack_eventmask_report(unsigned int eventmask, - struct nf_conn *ct, - u32 pid, - int report) {} -static inline void nf_conntrack_event(enum ip_conntrack_events event, - struct nf_conn *ct) {} -static inline void nf_conntrack_event_report(enum ip_conntrack_events event, - struct nf_conn *ct, - u32 pid, - int report) {} +static inline int nf_conntrack_eventmask_report(unsigned int eventmask, + struct nf_conn *ct, + u32 pid, + int report) { return 0; } +static inline int nf_conntrack_event(enum ip_conntrack_events event, + struct nf_conn *ct) { return 0; } +static inline int nf_conntrack_event_report(enum ip_conntrack_events event, + struct nf_conn *ct, + u32 pid, + int report) { return 0; } static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct) {} static inline void nf_ct_expect_event(enum ip_conntrack_expect_events event, struct nf_conntrack_expect *exp) {} diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h index 505a51cd8c63f8a9f5b470099df7c8bef2370b6b..ba1ba0c5efd1b5047d9251acee2211043e4d0805 100644 --- a/include/net/netns/conntrack.h +++ b/include/net/netns/conntrack.h @@ -14,8 +14,10 @@ struct netns_ct { struct hlist_nulls_head *hash; struct hlist_head *expect_hash; struct hlist_nulls_head unconfirmed; + struct hlist_nulls_head dying; struct ip_conntrack_stat *stat; int sysctl_events; + unsigned int sysctl_events_retry_timeout; int sysctl_acct; int sysctl_checksum; unsigned int sysctl_log_invalid; /* Log invalid packets */ diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 14235b144cb5cd861025c669c82017801bed415b..5f72b94b4918745f3491b48ba06cbc1714890280 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -183,10 +183,6 @@ destroy_conntrack(struct nf_conntrack *nfct) NF_CT_ASSERT(atomic_read(&nfct->use) == 0); NF_CT_ASSERT(!timer_pending(&ct->timeout)); - if (!test_bit(IPS_DYING_BIT, &ct->status)) - nf_conntrack_event(IPCT_DESTROY, ct); - set_bit(IPS_DYING_BIT, &ct->status); - /* To make sure we don't get any weird locking issues here: * destroy_conntrack() MUST NOT be called with a write lock * to nf_conntrack_lock!!! -HW */ @@ -220,9 +216,8 @@ destroy_conntrack(struct nf_conntrack *nfct) nf_conntrack_free(ct); } -static void death_by_timeout(unsigned long ul_conntrack) +void nf_ct_delete_from_lists(struct nf_conn *ct) { - struct nf_conn *ct = (void *)ul_conntrack; struct net *net = nf_ct_net(ct); nf_ct_helper_destroy(ct); @@ -232,6 +227,59 @@ static void death_by_timeout(unsigned long ul_conntrack) NF_CT_STAT_INC(net, delete_list); clean_from_lists(ct); spin_unlock_bh(&nf_conntrack_lock); +} +EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists); + +static void death_by_event(unsigned long ul_conntrack) +{ + struct nf_conn *ct = (void *)ul_conntrack; + struct net *net = nf_ct_net(ct); + + if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) { + /* bad luck, let's retry again */ + ct->timeout.expires = jiffies + + (random32() % net->ct.sysctl_events_retry_timeout); + add_timer(&ct->timeout); + return; + } + /* we've got the event delivered, now it's dying */ + set_bit(IPS_DYING_BIT, &ct->status); + spin_lock(&nf_conntrack_lock); + hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); + spin_unlock(&nf_conntrack_lock); + nf_ct_put(ct); +} + +void nf_ct_insert_dying_list(struct nf_conn *ct) +{ + struct net *net = nf_ct_net(ct); + + /* add this conntrack to the dying list */ + spin_lock_bh(&nf_conntrack_lock); + hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, + &net->ct.dying); + spin_unlock_bh(&nf_conntrack_lock); + /* set a new timer to retry event delivery */ + setup_timer(&ct->timeout, death_by_event, (unsigned long)ct); + ct->timeout.expires = jiffies + + (random32() % net->ct.sysctl_events_retry_timeout); + add_timer(&ct->timeout); +} +EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list); + +static void death_by_timeout(unsigned long ul_conntrack) +{ + struct nf_conn *ct = (void *)ul_conntrack; + + if (!test_bit(IPS_DYING_BIT, &ct->status) && + unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) { + /* destroy event was not delivered */ + nf_ct_delete_from_lists(ct); + nf_ct_insert_dying_list(ct); + return; + } + set_bit(IPS_DYING_BIT, &ct->status); + nf_ct_delete_from_lists(ct); nf_ct_put(ct); } @@ -982,11 +1030,13 @@ static int kill_report(struct nf_conn *i, void *data) { struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data; - /* get_next_corpse sets the dying bit for us */ - nf_conntrack_event_report(IPCT_DESTROY, - i, - fr->pid, - fr->report); + /* If we fail to deliver the event, death_by_timeout() will retry */ + if (nf_conntrack_event_report(IPCT_DESTROY, i, + fr->pid, fr->report) < 0) + return 1; + + /* Avoid the delivery of the destroy event in death_by_timeout(). */ + set_bit(IPS_DYING_BIT, &i->status); return 1; } @@ -1015,6 +1065,21 @@ void nf_conntrack_flush_report(struct net *net, u32 pid, int report) } EXPORT_SYMBOL_GPL(nf_conntrack_flush_report); +static void nf_ct_release_dying_list(void) +{ + struct nf_conntrack_tuple_hash *h; + struct nf_conn *ct; + struct hlist_nulls_node *n; + + spin_lock_bh(&nf_conntrack_lock); + hlist_nulls_for_each_entry(h, n, &init_net.ct.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(&nf_conntrack_lock); +} + static void nf_conntrack_cleanup_init_net(void) { nf_conntrack_helper_fini(); @@ -1026,6 +1091,7 @@ static void nf_conntrack_cleanup_net(struct net *net) { i_see_dead_people: nf_ct_iterate_cleanup(net, kill_all, NULL); + nf_ct_release_dying_list(); if (atomic_read(&net->ct.count) != 0) { schedule(); goto i_see_dead_people; @@ -1207,6 +1273,7 @@ static int nf_conntrack_init_net(struct net *net) atomic_set(&net->ct.count, 0); INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, 0); + INIT_HLIST_NULLS_HEAD(&net->ct.dying, 0); net->ct.stat = alloc_percpu(struct ip_conntrack_stat); if (!net->ct.stat) { ret = -ENOMEM; diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c index 683281b780471c50806490679a029ca4bf2198ef..aee560b4768dda0522107a9aefeff5d382022516 100644 --- a/net/netfilter/nf_conntrack_ecache.c +++ b/net/netfilter/nf_conntrack_ecache.c @@ -56,8 +56,21 @@ void nf_ct_deliver_cached_events(struct nf_conn *ct) .pid = 0, .report = 0 }; - - notify->fcn(events, &item); + int ret; + /* We make a copy of the missed event cache without taking + * the lock, thus we may send missed events twice. However, + * this does not harm and it happens very rarely. */ + unsigned long missed = e->missed; + + ret = notify->fcn(events | missed, &item); + if (unlikely(ret < 0 || missed)) { + spin_lock_bh(&ct->lock); + if (ret < 0) + e->missed |= events; + else + e->missed &= ~missed; + spin_unlock_bh(&ct->lock); + } } out_unlock: @@ -133,6 +146,7 @@ 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[] = { @@ -144,6 +158,14 @@ static struct ctl_table event_sysctl_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .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 */ @@ -165,6 +187,7 @@ 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; net->ct.event_sysctl_header = register_net_sysctl_table(net, @@ -205,6 +228,7 @@ int nf_conntrack_ecache_init(struct net *net) int ret; net->ct.sysctl_events = nf_ct_events; + net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout; if (net_eq(net, &init_net)) { ret = nf_ct_extend_register(&event_extend); diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 19706eff1647c815a89b9721f64dfa2f409424dd..49479d1945700b14a8e86de3c6781ed471411694 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -463,6 +463,7 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item) struct sk_buff *skb; unsigned int type; unsigned int flags = 0, group; + int err; /* ignore our fake conntrack entry */ if (ct == &nf_conntrack_untracked) @@ -558,7 +559,10 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item) rcu_read_unlock(); nlmsg_end(skb, nlh); - nfnetlink_send(skb, item->pid, group, item->report, GFP_ATOMIC); + err = nfnetlink_send(skb, item->pid, group, item->report, GFP_ATOMIC); + if (err == -ENOBUFS || err == -EAGAIN) + return -ENOBUFS; + return 0; nla_put_failure: @@ -798,10 +802,15 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb, } } - nf_conntrack_event_report(IPCT_DESTROY, - ct, - NETLINK_CB(skb).pid, - nlmsg_report(nlh)); + if (nf_conntrack_event_report(IPCT_DESTROY, ct, + NETLINK_CB(skb).pid, + nlmsg_report(nlh)) < 0) { + nf_ct_delete_from_lists(ct); + /* we failed to report the event, try later */ + nf_ct_insert_dying_list(ct); + nf_ct_put(ct); + return 0; + } /* death_by_timeout would report the event again */ set_bit(IPS_DYING_BIT, &ct->status);