From ba3fbe663635ae7b33a2d972c5d2def036258e42 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 16 Jan 2019 18:24:17 +0100 Subject: [PATCH] netfilter: nf_conntrack: provide modparam to always register conntrack hooks The connection tracking hooks can be optionally registered per netns when conntrack is specifically invoked from the ruleset since 0c66dc1ea3f0 ("netfilter: conntrack: register hooks in netns when needed by ruleset"). Then, since 4d3a57f23dec ("netfilter: conntrack: do not enable connection tracking unless needed"), the default behaviour is changed to always register them on demand. This patch provides a toggle that allows users to always register them. Without this toggle, in order to use conntrack for statistics collection, you need a dummy rule that refers to conntrack, eg. iptables -I INPUT -m state --state NEW This patch allows users to restore the original behaviour via modparam, ie. always register connection tracking, eg. modprobe nf_conntrack enable_hooks=1 Hence, no dummy rule is required. Reported-by: Laura Garcia Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_standalone.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index ddfca5f..8928a4d 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -24,6 +24,10 @@ #include #include +static bool enable_hooks __read_mostly; +MODULE_PARM_DESC(enable_hooks, "Always enable conntrack hooks"); +module_param(enable_hooks, bool, 0000); + unsigned int nf_conntrack_net_id __read_mostly; #ifdef CONFIG_NF_CONNTRACK_PROCFS @@ -1075,6 +1079,15 @@ static void nf_conntrack_standalone_fini_sysctl(struct net *net) } #endif /* CONFIG_SYSCTL */ +static void nf_conntrack_fini_net(struct net *net) +{ + if (enable_hooks) + nf_ct_netns_put(net, NFPROTO_INET); + + nf_conntrack_standalone_fini_proc(net); + nf_conntrack_standalone_fini_sysctl(net); +} + static int nf_conntrack_pernet_init(struct net *net) { int ret; @@ -1093,8 +1106,16 @@ static int nf_conntrack_pernet_init(struct net *net) if (ret < 0) goto out_init_net; + if (enable_hooks) { + ret = nf_ct_netns_get(net, NFPROTO_INET); + if (ret < 0) + goto out_hooks; + } + return 0; +out_hooks: + nf_conntrack_fini_net(net); out_init_net: nf_conntrack_standalone_fini_proc(net); out_proc: @@ -1106,10 +1127,9 @@ static void nf_conntrack_pernet_exit(struct list_head *net_exit_list) { struct net *net; - list_for_each_entry(net, net_exit_list, exit_list) { - nf_conntrack_standalone_fini_sysctl(net); - nf_conntrack_standalone_fini_proc(net); - } + list_for_each_entry(net, net_exit_list, exit_list) + nf_conntrack_fini_net(net); + nf_conntrack_cleanup_net_list(net_exit_list); } -- 2.7.4