From a992ca2a0498edd22a88ac8c41570f536de29c9e Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 19 Jan 2011 16:00:07 +0100 Subject: netfilter: nf_conntrack_tstamp: add flow-based timestamp extension This patch adds flow-based timestamping for conntracks. This conntrack extension is disabled by default. Basically, we use two 64-bits variables to store the creation timestamp once the conntrack has been confirmed and the other to store the deletion time. This extension is disabled by default, to enable it, you have to: echo 1 > /proc/sys/net/netfilter/nf_conntrack_timestamp This patch allows to save memory for user-space flow-based loogers such as ulogd2. In short, ulogd2 does not need to keep a hashtable with the conntrack in user-space to know when they were created and destroyed, instead we use the kernel timestamp. If we want to have a sane IPFIX implementation in user-space, this nanosecs resolution timestamps are also useful. Other custom user-space applications can benefit from this via libnetfilter_conntrack. This patch modifies the /proc output to display the delta time in seconds since the flow start. You can also obtain the flow-start date by means of the conntrack-tools. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy --- include/net/netfilter/nf_conntrack_extend.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/net/netfilter/nf_conntrack_extend.h') diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 1a9f96db3798..2dcf31703acb 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -16,6 +16,9 @@ enum nf_ct_ext_id { #endif #ifdef CONFIG_NF_CONNTRACK_ZONES NF_CT_EXT_ZONE, +#endif +#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP + NF_CT_EXT_TSTAMP, #endif NF_CT_EXT_NUM, }; @@ -25,6 +28,7 @@ enum nf_ct_ext_id { #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache #define NF_CT_EXT_ZONE_TYPE struct nf_conntrack_zone +#define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp /* Extensions: optional stuff which isn't permanently in struct. */ struct nf_ct_ext { -- cgit v1.2.3-59-g8ed1b