diff options
Diffstat (limited to 'net/netfilter/nfnetlink.c')
| -rw-r--r-- | net/netfilter/nfnetlink.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 7e2c8dd01408..ad3bbe34ca88 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -45,6 +45,7 @@ MODULE_DESCRIPTION("Netfilter messages via netlink socket"); static unsigned int nfnetlink_pernet_id __read_mostly; struct nfnl_net { + unsigned int ctnetlink_listeners; struct sock *nfnl; }; @@ -654,7 +655,6 @@ static void nfnetlink_rcv(struct sk_buff *skb) netlink_rcv_skb(skb, nfnetlink_rcv_msg); } -#ifdef CONFIG_MODULES static int nfnetlink_bind(struct net *net, int group) { const struct nfnetlink_subsystem *ss; @@ -670,9 +670,44 @@ static int nfnetlink_bind(struct net *net, int group) rcu_read_unlock(); if (!ss) request_module_nowait("nfnetlink-subsys-%d", type); + +#ifdef CONFIG_NF_CONNTRACK_EVENTS + if (type == NFNL_SUBSYS_CTNETLINK) { + struct nfnl_net *nfnlnet = nfnl_pernet(net); + + nfnl_lock(NFNL_SUBSYS_CTNETLINK); + + if (WARN_ON_ONCE(nfnlnet->ctnetlink_listeners == UINT_MAX)) { + nfnl_unlock(NFNL_SUBSYS_CTNETLINK); + return -EOVERFLOW; + } + + nfnlnet->ctnetlink_listeners++; + if (nfnlnet->ctnetlink_listeners == 1) + WRITE_ONCE(net->ct.ctnetlink_has_listener, true); + nfnl_unlock(NFNL_SUBSYS_CTNETLINK); + } +#endif return 0; } + +static void nfnetlink_unbind(struct net *net, int group) +{ +#ifdef CONFIG_NF_CONNTRACK_EVENTS + int type = nfnl_group2type[group]; + + if (type == NFNL_SUBSYS_CTNETLINK) { + struct nfnl_net *nfnlnet = nfnl_pernet(net); + + nfnl_lock(NFNL_SUBSYS_CTNETLINK); + WARN_ON_ONCE(nfnlnet->ctnetlink_listeners == 0); + nfnlnet->ctnetlink_listeners--; + if (nfnlnet->ctnetlink_listeners == 0) + WRITE_ONCE(net->ct.ctnetlink_has_listener, false); + nfnl_unlock(NFNL_SUBSYS_CTNETLINK); + } #endif +} static int __net_init nfnetlink_net_init(struct net *net) { @@ -680,9 +715,8 @@ static int __net_init nfnetlink_net_init(struct net *net) struct netlink_kernel_cfg cfg = { .groups = NFNLGRP_MAX, .input = nfnetlink_rcv, -#ifdef CONFIG_MODULES .bind = nfnetlink_bind, -#endif + .unbind = nfnetlink_unbind, }; nfnlnet->nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); |