From 42824d4b753f84ccf885eca602c5037338b546c8 Mon Sep 17 00:00:00 2001 From: Zhi Chen Date: Tue, 13 Jan 2015 14:28:18 -0800 Subject: [PATCH 3/3] net: conntrack events, support multiple registrant Merging this patch from kernel 3.4: This was supported by old (.28) kernel versions but removed because of it's overhead. But we need this feature for NA connection manager. Both ipv4 and ipv6 modules needs to register themselves to ct events. Change-Id: Iebfb254590fb594f5baf232f849d1b7ae45ef757 Signed-off-by: Zhi Chen --- include/net/netfilter/nf_conntrack_ecache.h | 42 ++++++++++++++++++- include/net/netns/conntrack.h | 4 ++ net/netfilter/Kconfig | 8 ++++ net/netfilter/nf_conntrack_core.c | 4 ++ net/netfilter/nf_conntrack_ecache.c | 63 +++++++++++++++++++++++++++++ net/netfilter/nf_conntrack_netlink.c | 17 ++++++++ 6 files changed, 137 insertions(+), 1 deletion(-) diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h index 57c8803..f921354 100644 --- a/include/net/netfilter/nf_conntrack_ecache.h +++ b/include/net/netfilter/nf_conntrack_ecache.h @@ -63,6 +63,10 @@ struct nf_ct_event { int report; }; +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +extern int nf_conntrack_register_notifier(struct net *net, struct notifier_block *nb); +extern int nf_conntrack_unregister_notifier(struct net *net, struct notifier_block *nb); +#else struct nf_ct_event_notifier { int (*fcn)(unsigned int events, struct nf_ct_event *item); }; @@ -71,17 +75,20 @@ int nf_conntrack_register_notifier(struct net *net, struct nf_ct_event_notifier *nb); void nf_conntrack_unregister_notifier(struct net *net, struct nf_ct_event_notifier *nb); +#endif void nf_ct_deliver_cached_events(struct nf_conn *ct); static inline void nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct) { - struct net *net = nf_ct_net(ct); struct nf_conntrack_ecache *e; +#ifndef CONFIG_NF_CONNTRACK_CHAIN_EVENTS + struct net *net = nf_ct_net(ct); if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) return; +#endif e = nf_ct_ecache_find(ct); if (e == NULL) @@ -90,6 +97,38 @@ nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct) set_bit(event, &e->cache); } +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +static inline int +nf_conntrack_eventmask_report(unsigned int eventmask, + struct nf_conn *ct, + u32 portid, + int report) +{ + struct nf_conntrack_ecache *e; + struct net *net = nf_ct_net(ct); + + e = nf_ct_ecache_find(ct); + if (e == NULL) + return 0; + + if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) { + struct nf_ct_event item = { + .ct = ct, + .portid = e->portid ? e->portid : portid, + .report = report + }; + /* This is a resent of a destroy event? If so, skip missed */ + unsigned long missed = e->portid ? 0 : e->missed; + + if (!((eventmask | missed) & e->ctmask)) + return 0; + + atomic_notifier_call_chain(&net->ct.nf_conntrack_chain, eventmask | missed, &item); + } + + return 0; +} +#else static inline int nf_conntrack_eventmask_report(unsigned int eventmask, struct nf_conn *ct, @@ -143,6 +182,7 @@ out_unlock: rcu_read_unlock(); return ret; } +#endif static inline int nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct, diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h index 723b61c..fbb9c16 100644 --- a/include/net/netns/conntrack.h +++ b/include/net/netns/conntrack.h @@ -100,7 +100,11 @@ struct netns_ct { struct hlist_head *expect_hash; struct ct_pcpu __percpu *pcpu_lists; struct ip_conntrack_stat __percpu *stat; +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS + struct atomic_notifier_head nf_conntrack_chain; +#else struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb; +#endif struct nf_exp_event_notifier __rcu *nf_expect_event_cb; struct nf_ip_net nf_ct_proto; #if defined(CONFIG_NF_CONNTRACK_LABELS) diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 7da6cef..c374447 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -136,6 +136,14 @@ config NF_CONNTRACK_TIMEOUT If unsure, say `N'. +config NF_CONNTRACK_CHAIN_EVENTS + bool "Register multiple callbacks to ct events" + depends on NF_CONNTRACK_EVENTS + help + Support multiple registrations. + + If unsure, say `N'. + config NF_CONNTRACK_TIMESTAMP bool 'Connection tracking timestamping' depends on NETFILTER_ADVANCED diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 86a3c6f..027c203 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1817,6 +1817,10 @@ int nf_conntrack_init_net(struct net *net) ret = nf_conntrack_proto_pernet_init(net); if (ret < 0) goto err_proto; + +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS + ATOMIC_INIT_NOTIFIER_HEAD(&net->ct.nf_conntrack_chain); +#endif return 0; err_proto: diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c index 4e78c57..d3e6773 100644 --- a/net/netfilter/nf_conntrack_ecache.c +++ b/net/netfilter/nf_conntrack_ecache.c @@ -18,6 +18,9 @@ #include #include #include +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +#include +#endif #include #include #include @@ -115,6 +118,51 @@ static void ecache_work(struct work_struct *work) /* deliver cached events and clear cache entry - must be called with locally * disabled softirqs */ +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +void nf_ct_deliver_cached_events(struct nf_conn *ct) +{ + unsigned long events, missed; + struct nf_conntrack_ecache *e; + struct nf_ct_event item; + struct net *net = nf_ct_net(ct); + int ret = 0; + + e = nf_ct_ecache_find(ct); + if (e == NULL) + return; + + events = xchg(&e->cache, 0); + + if (!nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct) || !events) + return; + + /* 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. */ + missed = e->missed; + + if (!((events | missed) & e->ctmask)) + return; + + item.ct = ct; + item.portid = 0; + item.report = 0; + + atomic_notifier_call_chain(&net->ct.nf_conntrack_chain, + events | missed, + &item); + + if (likely(ret >= 0 && !missed)) + return; + + spin_lock_bh(&ct->lock); + if (ret < 0) + e->missed |= events; + else + e->missed &= ~missed; + spin_unlock_bh(&ct->lock); +} +#else void nf_ct_deliver_cached_events(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); @@ -165,8 +213,15 @@ void nf_ct_deliver_cached_events(struct nf_conn *ct) out_unlock: rcu_read_unlock(); } +#endif EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +int nf_conntrack_register_notifier(struct net *net, struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&net->ct.nf_conntrack_chain, nb); +} +#else int nf_conntrack_register_notifier(struct net *net, struct nf_ct_event_notifier *new) { @@ -187,8 +242,15 @@ out_unlock: mutex_unlock(&nf_ct_ecache_mutex); return ret; } +#endif EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier); +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +int nf_conntrack_unregister_notifier(struct net *net, struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&net->ct.nf_conntrack_chain, nb); +} +#else void nf_conntrack_unregister_notifier(struct net *net, struct nf_ct_event_notifier *new) { @@ -201,6 +263,7 @@ void nf_conntrack_unregister_notifier(struct net *net, RCU_INIT_POINTER(net->ct.nf_conntrack_event_cb, NULL); mutex_unlock(&nf_ct_ecache_mutex); } +#endif EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier); int nf_ct_expect_register_notifier(struct net *net, diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 9f52729..8d8f355 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -28,6 +28,9 @@ #include #include #include +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +#include +#endif #include #include @@ -629,14 +632,22 @@ ctnetlink_nlmsg_size(const struct nf_conn *ct) } #ifdef CONFIG_NF_CONNTRACK_EVENTS +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +static int ctnetlink_conntrack_event(struct notifier_block *this, + unsigned long events, void *ptr) +#else static int ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item) +#endif { const struct nf_conntrack_zone *zone; struct net *net; struct nlmsghdr *nlh; struct nfgenmsg *nfmsg; struct nlattr *nest_parms; +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS + struct nf_ct_event *item = ptr; +#endif struct nf_conn *ct = item->ct; struct sk_buff *skb; unsigned int type; @@ -3258,9 +3269,15 @@ ctnetlink_stat_exp_cpu(struct sock *ctnl, struct sk_buff *skb, } #ifdef CONFIG_NF_CONNTRACK_EVENTS +#ifdef CONFIG_NF_CONNTRACK_CHAIN_EVENTS +static struct notifier_block ctnl_notifier = { + .notifier_call = ctnetlink_conntrack_event, +}; +#else static struct nf_ct_event_notifier ctnl_notifier = { .fcn = ctnetlink_conntrack_event, }; +#endif static struct nf_exp_event_notifier ctnl_notifier_exp = { .fcn = ctnetlink_expect_event, -- 2.7.4