From 538c5672be6d67b7b10c15701588e20617374973 Mon Sep 17 00:00:00 2001 From: Florent Fourcot Date: Sun, 6 May 2018 16:30:14 +0200 Subject: [PATCH] netfilter: ctnetlink: export nf_conntrack_max IPCTNL_MSG_CT_GET_STATS netlink command allow to monitor current number of conntrack entries. However, if one wants to compare it with the maximum (and detect exhaustion), the only solution is currently to read sysctl value. This patch add nf_conntrack_max value in netlink message, and simplify monitoring for application built on netlink API. Signed-off-by: Florent Fourcot Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nfnetlink_conntrack.h | 1 + net/netfilter/nf_conntrack_core.c | 1 + net/netfilter/nf_conntrack_netlink.c | 3 +++ 3 files changed, 5 insertions(+) diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h index 7798711..1d41810 100644 --- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h +++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h @@ -262,6 +262,7 @@ enum ctattr_stats_cpu { enum ctattr_stats_global { CTA_STATS_GLOBAL_UNSPEC, CTA_STATS_GLOBAL_ENTRIES, + CTA_STATS_GLOBAL_MAX_ENTRIES, __CTA_STATS_GLOBAL_MAX, }; #define CTA_STATS_GLOBAL_MAX (__CTA_STATS_GLOBAL_MAX - 1) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 41ff04e..6054417 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -186,6 +186,7 @@ unsigned int nf_conntrack_htable_size __read_mostly; EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); unsigned int nf_conntrack_max __read_mostly; +EXPORT_SYMBOL_GPL(nf_conntrack_max); seqcount_t nf_conntrack_generation __read_mostly; static unsigned int nf_conntrack_hash_rnd __read_mostly; diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 4c1d0c5..d807b87 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -2205,6 +2205,9 @@ ctnetlink_stat_ct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, if (nla_put_be32(skb, CTA_STATS_GLOBAL_ENTRIES, htonl(nr_conntracks))) goto nla_put_failure; + if (nla_put_be32(skb, CTA_STATS_GLOBAL_MAX_ENTRIES, htonl(nf_conntrack_max))) + goto nla_put_failure; + nlmsg_end(skb, nlh); return skb->len; -- 2.7.4