man: update man pages for TC MPLS actions

Add a man page describing the newly added TC mpls manipulation actions.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David Ahern <dsahern@gmail.com>

diff --git a/man/man8/tc-mpls.8 b/man/man8/tc-mpls.8
new file mode 100644 (file)
index 0000000..84ef2ef
--- /dev/null
+++ b/man/man8/tc-mpls.8
@@ -0,0 +1,156 @@
+.TH "MPLS manipulation action in tc" 8 "22 May 2019" "iproute2" "Linux"
+
+.SH NAME
+mpls - mpls manipulation module
+.SH SYNOPSIS
+.in +8
+.ti -8
+.BR tc " ... " "action mpls" " { "
+.IR POP " | " PUSH " | " MODIFY " | "
+.BR dec_ttl " } [ "
+.IR CONTROL " ]"
+
+.ti -8
+.IR POP " := "
+.BR pop " " protocol
+.IR MPLS_PROTO
+
+.ti -8
+.IR PUSH " := "
+.BR push " [ " protocol
+.IR MPLS_PROTO " ]"
+.RB " [ " tc
+.IR MPLS_TC " ] "
+.RB " [ " ttl
+.IR MPLS_TTL " ] "
+.RB " [ " bos
+.IR MPLS_BOS " ] "
+.BI label " MPLS_LABEL"
+
+.ti -8
+.IR MODIFY " := "
+.BR modify " [ " label
+.IR MPLS_LABEL " ]"
+.RB " [ " tc
+.IR MPLS_TC " ] "
+.RB " [ " ttl
+.IR MPLS_TTL " ] "
+
+.ti -8
+.IR CONTROL " := { "
+.BR reclassify " | " pipe " | " drop " | " continue " | " pass " | " goto " " chain " " CHAIN_INDEX " }"
+.SH DESCRIPTION
+The
+.B mpls
+action performs mpls encapsulation or decapsulation on a packet, reflected by the
+operation modes
+.IR POP ", " PUSH ", " MODIFY " and " DEC_TTL .
+The
+.I POP
+mode requires the ethertype of the header that follows the MPLS header (e.g.
+IPv4 or another MPLS). It will remove the outer MPLS header and replace the
+ethertype in the MAC header with that passed. The
+.IR PUSH " and " MODIFY
+modes update the current MPLS header information or add a new header.
+.IR PUSH
+requires at least an
+.IR MPLS_LABEL ". "
+.I DEC_TTL
+requires no arguments and simply subtracts 1 from the MPLS header TTL field.
+
+.SH OPTIONS
+.TP
+.B pop
+Decapsulation mode. Requires the protocol of the next header.
+.TP
+.B push
+Encapsulation mode. Requires at least the
+.B label
+option.
+.TP
+.B modify
+Replace mode. Existing MPLS tag is replaced.
+.BR label ", "
+.BR tc ", "
+and
+.B ttl
+are all optional.
+.TP
+.B dec_ttl
+Decrement the TTL field on the outer most MPLS header.
+.TP
+.BI label " MPLS_LABEL"
+Specify the MPLS LABEL for the outer MPLS header.
+.I MPLS_LABEL
+is an unsigned 20bit integer, the format is detected automatically (e.g. prefix
+with
+.RB ' 0x '
+for hexadecimal interpretation, etc.).
+.TP
+.BI protocol " MPLS_PROTO"
+Choose the protocol to use. For push actions this must be
+.BR mpls_uc " or " mpls_mc " (" mpls_uc
+is the default). For pop actions it should be the protocol of the next header.
+This option cannot be used with modify.
+.TP
+.BI tc " MPLS_TC"
+Choose the TC value for the outer MPLS header. Decimal number in range of 0-7.
+Defaults to 0.
+.TP
+.BI ttl " MPLS_TTL"
+Choose the TTL value for the outer MPLS header. Number in range of 0-255. A
+non-zero default value will be selected if this is not explicitly set.
+.TP
+.BI bos " MPLS_BOS"
+Manually configure the bottom of stack bit for an MPLS header push. The default
+is for TC to automatically set (or unset) the bit based on the next header of
+the packet.
+.TP
+.I CONTROL
+How to continue after executing this action.
+.RS
+.TP
+.B reclassify
+Restarts classification by jumping back to the first filter attached to this
+action's parent.
+.TP
+.B pipe
+Continue with the next action, this is the default.
+.TP
+.B drop
+Packet will be dropped without running further actions.
+.TP
+.B continue
+Continue classification with next filter in line.
+.TP
+.B pass
+Return to calling qdisc for packet processing. This ends the classification
+process.
+.RE
+.SH EXAMPLES
+The following example encapsulates incoming IP packets on eth0 into MPLS with
+a label 123 and sends them out eth1:
+
+.RS
+.EX
+#tc qdisc add dev eth0 handle ffff: ingress
+#tc filter add dev eth0 protocol ip parent ffff: flower \\
+       action mpls push protocol mpls_uc label 123  \\
+       action mirred egress redirect dev eth1
+.EE
+.RE
+
+In this example, incoming MPLS unicast packets on eth0 are decapsulated and to
+ip packets and output to eth1:
+
+.RS
+.EX
+#tc qdisc add dev eth0 handle ffff: ingress
+#tc filter add dev eth0 protocol mpls_uc parent ffff: flower \\
+       action mpls pop protocol ipv4  \\
+       action mirred egress redirect dev eth0
+.EE
+.RE
+
+.SH SEE ALSO
+.BR tc (8)