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04f48a68c4
Previously, if a flow action that involves a tunnel metadata meta-flow field is dumped from vswitchd, the replied field length in the OXM header is filled with the maximum possible field length, instead of the length configured in the tunnel TLV mapping table. To solve this issue, this patch introduces the following changes. In order to maintain the correct length of variable length mf_fields (i.e. tun_metadata), this patch creates a per-switch based map (struct vl_mff_map) that hosts the variable length mf_fields. This map is updated when a controller adds/deletes tlv-mapping entries to/from a switch. Although the per-swtch based vl_mff_map only hosts tun_metadata for now, it is able to support new variable length mf_fields in the future. With this commit, when a switch decodes a flow action with mf_field, the switch firstly looks up the global mf_fields map to identify the mf_field type. For the variable length mf_fields, the switch uses the vl_mff_map to get the configured mf_field entries. By lookig up vl_mff_map, the switch can check if the added flow action access beyond the configured size of a variable length mf_field, and the switch reports an ofperr if the controller adds a flow with unmapped variable length mf_field. Later on, when a controller request flows from the switch, with the per-switch based mf_fields, the switch will encode the OXM header with correct length for variable length mf_fields. To use the vl_mff_map for decoding flow actions, extract-ofp-actions is updated to pass the vl_mff_map to the required action decoding functions. Also, a new error code is introduced to identify a flow with an invalid variable length mf_field. Moreover, a testcase is added to prevent future regressions. Committer notes: - Factor out common code - Style fixups - Rename OFPERR_NXFMFC_INVALID_VL_MFF -> OFPERR_NXFMFC_INVALID_TLV_FIELD VMWare-BZ: #1768370 Reported-by: Harold Lim <haroldl@vmware.com> Suggested-by: Joe Stringer <joe@ovn.org> Suggested-by: Jarno Rajahalme <jarno@ovn.org> Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com> Signed-off-by: Joe Stringer <joe@ovn.org>
.. NOTE(stephenfin): If making changes to this file, ensure that the line
numbers found in 'Documentation/intro/what-is-ovs' are kept up-to-date.
============
Open vSwitch
============
.. image:: https://travis-ci.org/openvswitch/ovs.png
:target: https://travis-ci.org/openvswitch/ovs
What is Open vSwitch?
---------------------
Open vSwitch is a multilayer software switch licensed under the open source
Apache 2 license. Our goal is to implement a production quality switch
platform that supports standard management interfaces and opens the forwarding
functions to programmatic extension and control.
Open vSwitch is well suited to function as a virtual switch in VM environments.
In addition to exposing standard control and visibility interfaces to the
virtual networking layer, it was designed to support distribution across
multiple physical servers. Open vSwitch supports multiple Linux-based
virtualization technologies including Xen/XenServer, KVM, and VirtualBox.
The bulk of the code is written in platform-independent C and is easily ported
to other environments. The current release of Open vSwitch supports the
following features:
- Standard 802.1Q VLAN model with trunk and access ports
- NIC bonding with or without LACP on upstream switch
- NetFlow, sFlow(R), and mirroring for increased visibility
- QoS (Quality of Service) configuration, plus policing
- Geneve, GRE, VXLAN, STT, and LISP tunneling
- 802.1ag connectivity fault management
- OpenFlow 1.0 plus numerous extensions
- Transactional configuration database with C and Python bindings
- High-performance forwarding using a Linux kernel module
The included Linux kernel module supports Linux 3.10 and up.
Open vSwitch can also operate, at a cost in performance, entirely in userspace,
without assistance from a kernel module. This userspace implementation should
be easier to port than the kernel-based switch. It is considered experimental.
What's here?
------------
The main components of this distribution are:
- ovs-vswitchd, a daemon that implements the switch, along with a companion
Linux kernel module for flow-based switching.
- ovsdb-server, a lightweight database server that ovs-vswitchd queries to
obtain its configuration.
- ovs-dpctl, a tool for configuring the switch kernel module.
- Scripts and specs for building RPMs for Citrix XenServer and Red Hat
Enterprise Linux. The XenServer RPMs allow Open vSwitch to be installed on a
Citrix XenServer host as a drop-in replacement for its switch, with
additional functionality.
- ovs-vsctl, a utility for querying and updating the configuration of
ovs-vswitchd.
- ovs-appctl, a utility that sends commands to running Open vSwitch daemons.
Open vSwitch also provides some tools:
- ovs-ofctl, a utility for querying and controlling OpenFlow switches and
controllers.
- ovs-pki, a utility for creating and managing the public-key infrastructure
for OpenFlow switches.
- ovs-testcontroller, a simple OpenFlow controller that may be useful for
testing (though not for production).
- A patch to tcpdump that enables it to parse OpenFlow messages.
What other documentation is available?
--------------------------------------
.. TODO(stephenfin): Update with a link to the hosting site of the docs, once
we know where that is
To install Open vSwitch on a regular Linux or FreeBSD host, please read the
`installation guide <Documentation/intro/install/general.rst>`__. For specifics
around installation on a specific platform, refer to one of the `other
installation guides <Documentation/intro/install/index.rst>`__
For answers to common questions, refer to the `FAQ <Documentation/faq>`__.
To learn about some advanced features of the Open vSwitch software switch, read
the `tutorial <Documentation/tutorials/ovs-advanced.rst>`__.
Each Open vSwitch userspace program is accompanied by a manpage. Many of the
manpages are customized to your configuration as part of the build process, so
we recommend building Open vSwitch before reading the manpages.
Contact
-------
bugs@openvswitch.org