Adding upstream version 6.1.0.upstream/6.1.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/man/man8/tc-ctinfo.8 b/man/man8/tc-ctinfo.8
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+.TH "ctinfo action in tc" 8 "4 Jun 2019" "iproute2" "Linux"
+.SH NAME
+ctinfo \- tc connmark processing action
+.SH SYNOPSIS
+.B tc ... action ctinfo
+[
+.B dscp
+MASK [STATEMASK] ] [
+.B cpmark
+[MASK] ] [
+.B zone
+ZONE ] [
+.B CONTROL
+] [
+.B index
+<INDEX>
+]
+
+.SH DESCRIPTION
+CTINFO (Conntrack Information) is a tc action for retrieving data from
+conntrack marks into various fields.  At present it has two independent
+processing modes which may be viewed as sub-functions.
+
+DSCP mode copies a DSCP stored in conntrack's connmark into the IPv4/v6 diffserv
+field.  The copying may conditionally occur based on a flag also stored in the
+connmark.  DSCP mode was designed to assist in restoring packet classifications on
+ingress, classifications which may then be used by qdiscs such as CAKE.  It may be
+used in any circumstance where ingress classification needs to be maintained across
+links that otherwise bleach or remap according to their own policies.
+
+CPMARK (copymark) mode copies the conntrack connmark into the packet's mark field.  Without
+additional parameters it is functionally completely equivalent to the existing
+connmark action.  An optional mask may be specified to mask which bits of the
+connmark are restored.  This may be useful when DSCP and CPMARK modes are combined.
+
+Simple statistics (tc -s) on DSCP restores and CPMARK copies are maintained where values for
+set indicate a count of packets altered for that mode.  DSCP includes an error count
+where the destination packet's diffserv field was unwriteable.
+.SH PARAMETERS
+.SS DSCP mode parameters:
+.IP mask
+A mask of 6 contiguous bits indicating where the DSCP value is located in the 32 bit
+conntrack mark field.  A mask must be provided for this mode.  mask is a 32 bit
+unsigned value.
+.IP statemask
+A mask of at least 1 bit indicating where a conditional restore flag is located in the
+32 bit conntrack mark field.  The statemask bit/s must NOT overlap the mask bits.  The
+DSCP will be restored if the conntrack mark logically ANDed with the statemask yields
+a non-zero result.  statemask is an optional unsigned 32 bit value.
+.SS CPMARK mode parameters:
+.IP mask
+Store the logically ANDed result of conntrack mark and mask into the packet's mark
+field.  Default is 0xffffffff i.e. the whole mark field.  mask is an optional unsigned 32 bit
+value
+.SS Overall action parameters:
+.IP zone
+Specify the conntrack zone when doing conntrack lookups for packets.
+zone is a 16bit unsigned decimal value.
+Default is 0.
+.IP CONTROL
+The following keywords allow one to control how the tree of qdisc, classes,
+filters and actions is further traversed after this action.
+.RS
+.TP
+.B reclassify
+Restart with the first filter in the current list.
+.TP
+.B pipe
+Continue with the next action attached to the same filter.
+.TP
+.B drop
+Drop the packet.
+.TP
+.B shot
+synonym for
+.B drop
+.TP
+.B continue
+Continue classification with the next filter in line.
+.TP
+.B pass
+Finish classification process and return to calling qdisc for further packet
+processing. This is the default.
+.RE
+.IP index
+Specify an index for this action in order to being able to identify it in later
+commands. index is a 32bit unsigned decimal value.
+.SH EXAMPLES
+Example showing conditional restoration of DSCP on ingress via an IFB
+.RS
+.EX
+
+#Set up the IFB interface
+.br
+tc qdisc add dev ifb4eth0 handle ffff: ingress
+
+#Put CAKE qdisc on it
+.br
+tc qdisc add dev ifb4eth0 root cake bandwidth 40mbit
+
+#Set interface UP
+.br
+ip link set dev ifb4eth0 up
+
+#Add 2 actions, ctinfo to restore dscp & mirred to redirect the packets to IFB
+.br
+tc filter add dev eth0 parent ffff: protocol all prio 10 u32 \\
+    match u32 0 0 flowid 1:1 action    \\
+    ctinfo dscp 0xfc000000 0x01000000  \\
+    mirred egress redirect dev ifb4eth0
+
+tc -s qdisc show dev eth0 ingress
+
+ filter parent ffff: protocol all pref 10 u32 chain 0
+ filter parent ffff: protocol all pref 10 u32 chain 0 fh 800: ht divisor 1
+ filter parent ffff: protocol all pref 10 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 not_in_hw
+  match 00000000/00000000 at 0
+    action order 1: ctinfo zone 0 pipe
+    index 2 ref 1 bind 1 dscp 0xfc000000 0x01000000 installed 72 sec used 0 sec DSCP set 1333 error 0 CPMARK set 0
+    Action statistics:
+    Sent 658484 bytes 1833 pkt (dropped 0, overlimits 0 requeues 0)
+    backlog 0b 0p requeues 0
+
+    action order 2: mirred (Egress Redirect to device ifb4eth0) stolen
+    index 1 ref 1 bind 1 installed 72 sec used 0 sec
+    Action statistics:
+    Sent 658484 bytes 1833 pkt (dropped 0, overlimits 0 requeues 0)
+    backlog 0b 0p requeues 0
+.EE
+.RE
+
+Example showing conditional restoration of DSCP on egress
+
+This may appear nonsensical since iptables marking of egress packets is easy
+to achieve, however the iptables flow classification rules may be extensive
+and so some sort of set once and forget may be useful especially on cpu
+constrained devices.
+.RS
+.EX
+
+# Send unmarked connections to a marking chain which needs to store a DSCP
+and set statemask bit in the connmark
+.br
+iptables -t mangle -A POSTROUTING -o eth0 -m connmark \\
+    --mark 0x00000000/0x01000000 -g CLASS_MARKING_CHAIN
+
+# Apply marked DSCP to the packets
+.br
+tc filter add dev eth0 protocol all prio 10 u32 \\
+    match u32 0 0 flowid 1:1 action \\
+    ctinfo dscp 0xfc000000 0x01000000
+
+tc -s filter show dev eth0
+ filter parent 800e: protocol all pref 10 u32 chain 0
+ filter parent 800e: protocol all pref 10 u32 chain 0 fh 800: ht divisor 1
+ filter parent 800e: protocol all pref 10 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 not_in_hw
+  match 00000000/00000000 at 0
+    action order 1: ctinfo zone 0 pipe
+    index 1 ref 1 bind 1 dscp 0xfc000000 0x01000000 installed 7414 sec used 0 sec DSCP set 53404 error 0 CPMARK set 0
+    Action statistics:
+    Sent 32890260 bytes 120441 pkt (dropped 0, overlimits 0 requeues 0)
+    backlog 0b 0p requeues 0
+.br
+.RE
+.SH SEE ALSO
+.BR tc (8),
+.BR tc-cake (8)
+.BR tc-connmark (8)
+.BR tc-mirred (8)
+.SH AUTHORS
+ctinfo was written by Kevin Darbyshire-Bryant.