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authorJiri Pirko <jiri@resnulli.us>2013-01-18 03:05:08 +0400
committerPablo Neira Ayuso <pablo@netfilter.org>2013-01-21 15:50:06 +0400
commitc9f9e0e1597f99d605212356f5a220c757d190ac (patch)
tree920fc1c756d592078341dcc46a3ffba17ae7b0db /Documentation/networking/nf_conntrack-sysctl.txt
parente7db3cbcd6508235d63ba4a31bbd1ce4fdece6e1 (diff)
downloadlinux-c9f9e0e1597f99d605212356f5a220c757d190ac.tar.xz
netfilter: doc: add nf_conntrack sysctl api documentation
I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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+/proc/sys/net/netfilter/nf_conntrack_* Variables:
+
+nf_conntrack_acct - BOOLEAN
+ 0 - disabled (default)
+ not 0 - enabled
+
+ Enable connection tracking flow accounting. 64-bit byte and packet
+ counters per flow are added.
+
+nf_conntrack_buckets - INTEGER (read-only)
+ Size of hash table. If not specified as parameter during module
+ loading, the default size is calculated by dividing total memory
+ by 16384 to determine the number of buckets but the hash table will
+ never have fewer than 32 or more than 16384 buckets.
+
+nf_conntrack_checksum - BOOLEAN
+ 0 - disabled
+ not 0 - enabled (default)
+
+ Verify checksum of incoming packets. Packets with bad checksums are
+ in INVALID state. If this is enabled, such packets will not be
+ considered for connection tracking.
+
+nf_conntrack_count - INTEGER (read-only)
+ Number of currently allocated flow entries.
+
+nf_conntrack_events - BOOLEAN
+ 0 - disabled
+ not 0 - enabled (default)
+
+ If this option is enabled, the connection tracking code will
+ provide userspace with connection tracking events via ctnetlink.
+
+nf_conntrack_events_retry_timeout - INTEGER (seconds)
+ default 15
+
+ This option is only relevant when "reliable connection tracking
+ events" are used. Normally, ctnetlink is "lossy", that is,
+ events are normally dropped when userspace listeners can't keep up.
+
+ Userspace can request "reliable event mode". When this mode is
+ active, the conntrack will only be destroyed after the event was
+ delivered. If event delivery fails, the kernel periodically
+ re-tries to send the event to userspace.
+
+ This is the maximum interval the kernel should use when re-trying
+ to deliver the destroy event.
+
+ A higher number means there will be fewer delivery retries and it
+ will take longer for a backlog to be processed.
+
+nf_conntrack_expect_max - INTEGER
+ Maximum size of expectation table. Default value is
+ nf_conntrack_buckets / 256. Minimum is 1.
+
+nf_conntrack_frag6_high_thresh - INTEGER
+ default 262144
+
+ Maximum memory used to reassemble IPv6 fragments. When
+ nf_conntrack_frag6_high_thresh bytes of memory is allocated for this
+ purpose, the fragment handler will toss packets until
+ nf_conntrack_frag6_low_thresh is reached.
+
+nf_conntrack_frag6_low_thresh - INTEGER
+ default 196608
+
+ See nf_conntrack_frag6_low_thresh
+
+nf_conntrack_frag6_timeout - INTEGER (seconds)
+ default 60
+
+ Time to keep an IPv6 fragment in memory.
+
+nf_conntrack_generic_timeout - INTEGER (seconds)
+ default 600
+
+ Default for generic timeout. This refers to layer 4 unknown/unsupported
+ protocols.
+
+nf_conntrack_helper - BOOLEAN
+ 0 - disabled
+ not 0 - enabled (default)
+
+ Enable automatic conntrack helper assignment.
+
+nf_conntrack_icmp_timeout - INTEGER (seconds)
+ default 30
+
+ Default for ICMP timeout.
+
+nf_conntrack_icmpv6_timeout - INTEGER (seconds)
+ default 30
+
+ Default for ICMP6 timeout.
+
+nf_conntrack_log_invalid - INTEGER
+ 0 - disable (default)
+ 1 - log ICMP packets
+ 6 - log TCP packets
+ 17 - log UDP packets
+ 33 - log DCCP packets
+ 41 - log ICMPv6 packets
+ 136 - log UDPLITE packets
+ 255 - log packets of any protocol
+
+ Log invalid packets of a type specified by value.
+
+nf_conntrack_max - INTEGER
+ Size of connection tracking table. Default value is
+ nf_conntrack_buckets value * 4.
+
+nf_conntrack_tcp_be_liberal - BOOLEAN
+ 0 - disabled (default)
+ not 0 - enabled
+
+ Be conservative in what you do, be liberal in what you accept from others.
+ If it's non-zero, we mark only out of window RST segments as INVALID.
+
+nf_conntrack_tcp_loose - BOOLEAN
+ 0 - disabled
+ not 0 - enabled (default)
+
+ If it is set to zero, we disable picking up already established
+ connections.
+
+nf_conntrack_tcp_max_retrans - INTEGER
+ default 3
+
+ Maximum number of packets that can be retransmitted without
+ received an (acceptable) ACK from the destination. If this number
+ is reached, a shorter timer will be started.
+
+nf_conntrack_tcp_timeout_close - INTEGER (seconds)
+ default 10
+
+nf_conntrack_tcp_timeout_close_wait - INTEGER (seconds)
+ default 60
+
+nf_conntrack_tcp_timeout_established - INTEGER (seconds)
+ default 432000 (5 days)
+
+nf_conntrack_tcp_timeout_fin_wait - INTEGER (seconds)
+ default 120
+
+nf_conntrack_tcp_timeout_last_ack - INTEGER (seconds)
+ default 30
+
+nf_conntrack_tcp_timeout_max_retrans - INTEGER (seconds)
+ default 300
+
+nf_conntrack_tcp_timeout_syn_recv - INTEGER (seconds)
+ default 60
+
+nf_conntrack_tcp_timeout_syn_sent - INTEGER (seconds)
+ default 120
+
+nf_conntrack_tcp_timeout_time_wait - INTEGER (seconds)
+ default 120
+
+nf_conntrack_tcp_timeout_unacknowledged - INTEGER (seconds)
+ default 300
+
+nf_conntrack_timestamp - BOOLEAN
+ 0 - disabled (default)
+ not 0 - enabled
+
+ Enable connection tracking flow timestamping.
+
+nf_conntrack_udp_timeout - INTEGER (seconds)
+ default 30
+
+nf_conntrack_udp_timeout_stream2 - INTEGER (seconds)
+ default 180
+
+ This extended timeout will be used in case there is an UDP stream
+ detected.