netgraph/ng_vlan_rotate: IEEE 802.1ad VLAN manipulation netgraph type

This node is part of an A10-NSP (L2-BSA) development.

Carrier networks tend to stack three or more tags for internal
purposes and therefore hiding the service tags deep inside of the
stack. When decomposing such an access network frame, the processing
order is typically reversed: First distinguish by service, than by
other means.

This new netgragh node allows to bring the relevant VLAN in front (to
the out-most position). This way other netgraph nodes (like ng_vlan)
can operate on this specific type.

Reviewed by:	manpages (gbe), brueffer (manpages), kp
Approved by:	kp (mentor)
MFC after:	1 month
Relnotes:	yes
Sponsored by:	IKS Service GmbH
Differential Revision: https://reviews.freebsd.org/D22076

2 files changed, 253 insertions, 0 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index 65f8bc817db3..9b6ec7998fc3 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -393,6 +393,7 @@ MAN=	aac.4 \
 	ng_uni.4 \
 	ng_vjc.4 \
 	ng_vlan.4 \
+	ng_vlan_rotate.4 \
 	nmdm.4 \
 	${_ntb.4} \
 	${_ntb_hw_amd.4} \
diff --git a/share/man/man4/ng_vlan_rotate.4 b/share/man/man4/ng_vlan_rotate.4
new file mode 100644
index 000000000000..4640737c7d54
--- /dev/null
+++ b/share/man/man4/ng_vlan_rotate.4
@@ -0,0 +1,252 @@
+.\"-
+.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+.\"
+.\" Copyright (c) 2019-2021 IKS Service GmbH
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" Author: Lutz Donnerhacke <lutz@donnerhacke.de>
+.\"
+.\" $FreeBSD$
+.\"
+.Dd January 26, 2021
+.Dt NG_VLAN_ROTATE 4
+.Os
+.Sh NAME
+.Nm ng_vlan_rotate
+.Nd IEEE 802.1ad VLAN manipulation netgraph node type
+.Sh SYNOPSIS
+.In sys/types.h
+.In netgraph.h
+.In netgraph/ng_vlan_rotate.h
+.Sh DESCRIPTION
+The
+.Nm
+node type manipulates the order of VLAN tags of frames tagged
+according to the IEEE 802.1ad (an extension of IEEE 802.1Q) standard
+between different hooks.
+.Pp
+Each node has four special hooks,
+.Va original ,
+.Va ordered ,
+.Va excessive ,
+and
+.Va incomplete .
+.Pp
+A frame tagged with an arbitrary number of
+.Dv ETHERTYPE_VLAN ,
+.Dv ETHERTYPE_QINQ ,
+and
+.Dv 0x9100
+tags received on the
+.Va original
+hook will be rearranged to a new order of those tags and is sent out
+the
+.Dq ordered
+hook.
+After successful processing the
+.Va histogram
+counter for the observed stack size increments.
+.Pp
+If it contains fewer VLANs in the stack than the configured
+.Va min
+limit, the frame is sent out to the
+.Va incomplete
+hook and the
+.Va incomplete
+counter increments.
+.Pp
+If there are more VLANs in the stack than the configured
+.Va max
+limit, the frame is sent out to the
+.Va excessive
+hook and the
+.Va excessive
+counter increments.
+.Pp
+If the destination hook is not connected, the frame is dropped and the
+.Va drops
+counter increments.
+.Pp
+For Ethernet frames received on the
+.Va ordered
+hook, the transformation is reversed and is passed to the
+.Va original
+hook.
+Please note that this process is identical to the one described
+above, besides the ordered/original hooks are swapped and the
+transformation is reversed.
+.Pp
+An Ethernet frame received on the
+.Va incomplete
+or
+.Va excessive
+hook is forwarded to the
+.Va original
+hook without any modification.
+.Pp
+This node supports only one operation at the moment: Rotation of the
+VLANs in the stack.
+Setting the configuration parameter
+.Va rot
+to a positive value, the stack will roll up by this amount.
+Negative values will roll down.
+A typical scenario is setting the value to 1 in order to bring the
+innermost VLAN tag to the outmost level.
+Rotation includes the VLAN id, the ether type, and the QOS parameters
+pcp and cfi.
+Typical QOS handling refers to the outmost setting, so be careful to
+keep your QOS intact.
+.Sh HOOKS
+This node type supports the following hooks:
+.Bl -tag -width incomplete
+.It Va original
+Typically this hook would be connected to a
+.Xr ng_ether 4
+node, using the
+.Va lower
+hook connected to a carrier network.
+.It Va ordered
+Typically this hook would be connected to a
+.Xr ng_vlan 4
+type node using the
+.Va downstream
+hook in order to separate services.
+.It Va excessive
+see below.
+.It Va incomplete
+Typically those hooks would be attached to a
+.Xr ng_eiface 4
+type node using the
+.Va ether
+hook for anomaly monitoring purposes.
+.El
+.Sh CONTROL MESSAGES
+This node type supports the generic control messages, plus the following:
+.Bl -tag -width foo
+.It Dv NGM_VLANROTATE_GET_CONF Pq Ic getconf
+Read the current configuration.
+.It Dv NGM_VLANROTATE_SET_CONF Pq Ic setconf
+Set the current configuration.
+.It Dv NGM_VLANROTATE_GET_STAT Pq Ic getstat
+Read the current statistics.
+.It Dv NGM_VLANROTATE_CLR_STAT Pq Ic clrstat
+Zeroize the statistics.
+.It Dv NGM_VLANROTATE_GETCLR_STAT Pq Ic getclrstat
+Read the current statistics and zeroize it in one step.
+.El
+.Sh EXAMPLES
+The first example demonstrates how to rotate double or triple tagged
+frames so that the innermost C-VLAN can be used as service
+discriminator.
+The single or double tagged frames (C-VLAN removed) are sent out to an
+interface pointing to different infrastucture.
+.Bd -literal
+#!/bin/sh
+
+BNG_IF=ixl3
+VOIP_IF=bge2
+
+ngctl -f- <<EOF
+mkpeer ${BNG_IF}: vlan_rotate lower original
+name ${BNG_IF}:lower rotate
+msg rotate: setconf { min=2 max=3 rot=1 }
+mkpeer rotate: vlan ordered downstream
+name rotate:ordered services
+connect services: ${VOIP_IF} voip lower
+msg services: addfilter { vlan=123 hook="voip" }
+EOF
+.Ed
+.Pp
+Now inject the following sample frame on the
+.Dv BNG_IF
+interface:
+.Bd -literal
+00:00:00:00:01:01 > 00:01:02:03:04:05,
+ ethertype 802.1Q-9100 (0x9100), length 110: vlan 2, p 1,
+ ethertype 802.1Q-QinQ, vlan 101, p 0,
+ ethertype 802.1Q, vlan 123, p 7,
+ ethertype IPv4, (tos 0x0, ttl 64, id 15994, offset 0, flags [none],
+  proto ICMP (1), length 84) 192.168.140.101 > 192.168.140.1:
+  ICMP echo request, id 40234, seq 0, length 64
+.Ed
+.Pp
+The frame ejected on the
+.Va ordered
+hook will look like this:
+.Bd -literal
+00:00:00:00:01:01 > 00:01:02:03:04:05,
+ ethertype 802.1Q (0x8100), length 110: vlan 123, p 7,
+ ethertype 802.1Q-9100, vlan 2, p 1,
+ ethertype 802.1Q-QinQ, vlan 101, p 0,
+ ethertype IPv4, (tos 0x0, ttl 64, id 15994, offset 0, flags [none],
+  proto ICMP (1), length 84) 192.168.140.101 > 192.168.140.1:
+  ICMP echo request, id 40234, seq 0, length 64
+.Ed
+.Pp
+Hence, the frame pushed out to the
+.Dv VOIP_IF
+will have this form:
+.Bd -literal
+00:00:00:00:01:01 > 00:01:02:03:04:05,
+ ethertype 802.1Q-9100, vlan 2, p 1,
+ ethertype 802.1Q-QinQ, vlan 101, p 0,
+ ethertype IPv4, (tos 0x0, ttl 64, id 15994, offset 0, flags [none],
+  proto ICMP (1), length 84) 192.168.140.101 > 192.168.140.1:
+  ICMP echo request, id 40234, seq 0, length 64
+.Ed
+.Pp
+The second example distinguishes between double tagged and single
+tagged frames.
+.Bd -literal
+#!/bin/sh
+
+IN_IF=bge1
+
+ngctl -f- <<EOF
+mkpeer ${IN_IF}: vlan_rotate lower original
+name ${IN_IF}:lower separate
+msg separate: setconf { min=1 max=1 rot=0 }
+mkpeer separate: eiface incomplete ether
+name separate:incomplete untagged
+mkpeer separate: eiface ordered ether
+name separate:ordered tagged
+EOF
+.Ed
+.Pp
+Setting the
+.Va rot
+parameter to zero (or omitting it) does not change
+the order of the tags within the frame.
+Frames with more VLAN tags are dropped.
+.Sh SHUTDOWN
+This node shuts down upon receipt of a
+.Dv NGM_SHUTDOWN
+control message, or when all hooks have been disconnected.
+.Sh SEE ALSO
+.Xr netgraph 4 ,
+.Xr ng_eiface 4 ,
+.Xr ng_ether 4 ,
+.Xr ng_vlan 4 ,
+.Xr ngctl 8
+.Sh AUTHORS
+.An Lutz Donnerhacke Aq Mt lutz@donnerhacke.de