90d1daa458
This adds the new nf_conntrack_events=2 mode and makes it the default. This leverages the earlier flag in struct net to allow to avoid the event extension as long as no event listener is active in the namespace. This avoids, for most cases, allocation of ct->ext area. A followup patch will take further advantage of this by avoiding calls down into the event framework if the extension isn't present. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
213 lines
6.1 KiB
ReStructuredText
213 lines
6.1 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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===================================
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Netfilter Conntrack Sysfs variables
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===================================
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/proc/sys/net/netfilter/nf_conntrack_* Variables:
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=================================================
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nf_conntrack_acct - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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Enable connection tracking flow accounting. 64-bit byte and packet
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counters per flow are added.
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nf_conntrack_buckets - INTEGER
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Size of hash table. If not specified as parameter during module
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loading, the default size is calculated by dividing total memory
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by 16384 to determine the number of buckets. The hash table will
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never have fewer than 1024 and never more than 262144 buckets.
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This sysctl is only writeable in the initial net namespace.
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nf_conntrack_checksum - BOOLEAN
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- 0 - disabled
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- not 0 - enabled (default)
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Verify checksum of incoming packets. Packets with bad checksums are
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in INVALID state. If this is enabled, such packets will not be
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considered for connection tracking.
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nf_conntrack_count - INTEGER (read-only)
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Number of currently allocated flow entries.
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nf_conntrack_events - BOOLEAN
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- 0 - disabled
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- 1 - enabled
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- 2 - auto (default)
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If this option is enabled, the connection tracking code will
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provide userspace with connection tracking events via ctnetlink.
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The default allocates the extension if a userspace program is
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listening to ctnetlink events.
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nf_conntrack_expect_max - INTEGER
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Maximum size of expectation table. Default value is
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nf_conntrack_buckets / 256. Minimum is 1.
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nf_conntrack_frag6_high_thresh - INTEGER
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default 262144
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Maximum memory used to reassemble IPv6 fragments. When
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nf_conntrack_frag6_high_thresh bytes of memory is allocated for this
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purpose, the fragment handler will toss packets until
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nf_conntrack_frag6_low_thresh is reached.
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nf_conntrack_frag6_low_thresh - INTEGER
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default 196608
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See nf_conntrack_frag6_low_thresh
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nf_conntrack_frag6_timeout - INTEGER (seconds)
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default 60
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Time to keep an IPv6 fragment in memory.
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nf_conntrack_generic_timeout - INTEGER (seconds)
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default 600
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Default for generic timeout. This refers to layer 4 unknown/unsupported
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protocols.
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nf_conntrack_helper - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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Enable automatic conntrack helper assignment.
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If disabled it is required to set up iptables rules to assign
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helpers to connections. See the CT target description in the
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iptables-extensions(8) man page for further information.
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nf_conntrack_icmp_timeout - INTEGER (seconds)
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default 30
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Default for ICMP timeout.
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nf_conntrack_icmpv6_timeout - INTEGER (seconds)
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default 30
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Default for ICMP6 timeout.
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nf_conntrack_log_invalid - INTEGER
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- 0 - disable (default)
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- 1 - log ICMP packets
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- 6 - log TCP packets
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- 17 - log UDP packets
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- 33 - log DCCP packets
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- 41 - log ICMPv6 packets
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- 136 - log UDPLITE packets
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- 255 - log packets of any protocol
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Log invalid packets of a type specified by value.
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nf_conntrack_max - INTEGER
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Maximum number of allowed connection tracking entries. This value is set
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to nf_conntrack_buckets by default.
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Note that connection tracking entries are added to the table twice -- once
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for the original direction and once for the reply direction (i.e., with
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the reversed address). This means that with default settings a maxed-out
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table will have a average hash chain length of 2, not 1.
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nf_conntrack_tcp_be_liberal - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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Be conservative in what you do, be liberal in what you accept from others.
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If it's non-zero, we mark only out of window RST segments as INVALID.
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nf_conntrack_tcp_ignore_invalid_rst - BOOLEAN
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- 0 - disabled (default)
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- 1 - enabled
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If it's 1, we don't mark out of window RST segments as INVALID.
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nf_conntrack_tcp_loose - BOOLEAN
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- 0 - disabled
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- not 0 - enabled (default)
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If it is set to zero, we disable picking up already established
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connections.
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nf_conntrack_tcp_max_retrans - INTEGER
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default 3
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Maximum number of packets that can be retransmitted without
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received an (acceptable) ACK from the destination. If this number
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is reached, a shorter timer will be started.
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nf_conntrack_tcp_timeout_close - INTEGER (seconds)
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default 10
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nf_conntrack_tcp_timeout_close_wait - INTEGER (seconds)
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default 60
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nf_conntrack_tcp_timeout_established - INTEGER (seconds)
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default 432000 (5 days)
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nf_conntrack_tcp_timeout_fin_wait - INTEGER (seconds)
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default 120
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nf_conntrack_tcp_timeout_last_ack - INTEGER (seconds)
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default 30
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nf_conntrack_tcp_timeout_max_retrans - INTEGER (seconds)
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default 300
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nf_conntrack_tcp_timeout_syn_recv - INTEGER (seconds)
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default 60
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nf_conntrack_tcp_timeout_syn_sent - INTEGER (seconds)
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default 120
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nf_conntrack_tcp_timeout_time_wait - INTEGER (seconds)
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default 120
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nf_conntrack_tcp_timeout_unacknowledged - INTEGER (seconds)
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default 300
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nf_conntrack_timestamp - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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Enable connection tracking flow timestamping.
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nf_conntrack_udp_timeout - INTEGER (seconds)
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default 30
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nf_conntrack_udp_timeout_stream - INTEGER (seconds)
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default 120
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This extended timeout will be used in case there is an UDP stream
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detected.
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nf_conntrack_gre_timeout - INTEGER (seconds)
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default 30
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nf_conntrack_gre_timeout_stream - INTEGER (seconds)
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default 180
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This extended timeout will be used in case there is an GRE stream
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detected.
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nf_hooks_lwtunnel - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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If this option is enabled, the lightweight tunnel netfilter hooks are
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enabled. This option cannot be disabled once it is enabled.
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nf_flowtable_tcp_timeout - INTEGER (seconds)
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default 30
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Control offload timeout for tcp connections.
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TCP connections may be offloaded from nf conntrack to nf flow table.
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Once aged, the connection is returned to nf conntrack with tcp pickup timeout.
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nf_flowtable_udp_timeout - INTEGER (seconds)
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default 30
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Control offload timeout for udp connections.
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UDP connections may be offloaded from nf conntrack to nf flow table.
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Once aged, the connection is returned to nf conntrack with udp pickup timeout.
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