For SNAT, don't store the pre-fragment L2 header before actions are applied.

[sliver-openvswitch.git] / INSTALL

       Installation Instructions for OpenFlow Reference Release

This document describes how to build, install, and execute the
reference implementation of OpenFlow.  Please send any comments to:

                      <info@openflowswitch.org>

Contents
========

The OpenFlow reference implementation includes two OpenFlow switch
implementations:

        - The "kernel-based switch": This divides the switch into a
          "datapath" Linux kernel module (openflow_mod.o for Linux 2.4
          or openflow_mod.ko for Linux 2.6) and a userspace program
          (secchan).  The kernel-based switch is faster than either of
          the other two implementations but requires building and
          installing a kernel module, which can sometimes be
          challenging.

        - The "userspace datapath-based switch": This divides the
          switch into a userspace "datapath" (built as
          udatapath/udatapath) and the same userspace program used by
          the kernel-based switch (secchan).  The userspace
          datapath-based switch does not require building a kernel
          module, but it is not as fast as the kernel-based switch.

The reference implementation also contains a simple OpenFlow
controller (built as controller/controller) and a number of related
utilities.

Build Methods
=============

There are two principal ways to build and install this distribution:

        - Using "configure" and "make" in the ordinary way.  See
          Building Conventionally below for detailed instructions.

        - As a set of Debian packages.  Refer to Building Debian
          Packages, below, for instructions.

Base Prerequisites
------------------

Regardless of how it is built, OpenFlow has a common set of
prerequisites.  To compile the userspace programs in the OpenFlow
reference distribution, you will need the following software:

    - A make program, e.g. GNU make
      (http://www.gnu.org/software/make/).  BSD make should also work.

    - The GNU C compiler (http://gcc.gnu.org/).  We generally test
      with version 4.1 or 4.2.

    - libssl, from OpenSSL (http://www.openssl.org/), is optional but
      recommended.  libssl is required to establish confidentiality
      and authenticity in the connections among OpenFlow switches and
      controllers.  To enable, configure with --enable-ssl=yes.

If you are working from a Git tree or snapshot (instead of from a
distribution tarball), or if you modify the OpenFlow build system, you
will also need the following software:

    - Autoconf version 2.60 or later (http://www.gnu.org/software/autoconf).

    - Automake version 1.10 or later (http://www.gnu.org/software/automake).  

    - pkg-config (http://pkg-config.freedesktop.org/wiki/).  We test
      with version 0.22.

Debian Prerequisites
--------------------

To build Debian packages from the OpenFlow distribution, you will need
to install a number of Debian packages in addition to the base
prerequisites listed above.  These additional prerequisites may be
found listed as "Build-Depends" in debian/control in the source tree.
To check that they are installed, first install the dpkg-dev package,
then run dpkg-checkbuilddeps from the top level of the OpenFlow source
tree.

To build Debian packages without being root, also install the
"fakeroot" package.

Kernel-Based Switch Prerequisites
---------------------------------

The OpenFlow distribution also includes a Linux kernel module that can
be used to achieve higher switching performance.  To compile the
kernel module, you must install the following in addition to the
software listed in the "Base Prerequisites" section above:

    - A supported Linux kernel version.  Please refer to README for a
      list of supported versions.

      The OpenFlow datapath requires bridging support (CONFIG_BRIDGE)
      to be built as a kernel module.  (This is common in kernels
      provided by Linux distributions.)  The bridge module must not be
      loaded or in use.  If the bridge module is running (check with
      "lsmod | grep bridge"), you must remove it ("rmmod bridge")
      before starting the datapath.

      In kernels prior to 2.6.9, VLAN support (CONFIG_VLAN_8021Q) must 
      be compiled either directly or as a module.  Failure to do this
      will cause an error on module insertion due to the 
      "dev_change_flags" symbol being undefined.

    - The correct version of GCC for the kernel that you are building
      the module against:

        * To build a kernel module for a Linux 2.6 kernel, you need
          the same version of GCC that was used to build that kernel
          (usually version 4.0 or later).

        * To build a kernel module for a Linux 2.4 kernel, you need an
          earlier version of GCC, typically GCC 2.95, 3.3, or 3.4.

    - A kernel build directory corresponding to the Linux kernel image
      the module is to run on.  Under Debian and Ubuntu, for example,
      each linux-image package containing a kernel binary has a
      corresponding linux-headers package with the required build
      infrastructure.

Building Conventionally
=======================

This section explains how to build and install the OpenFlow
distribution in the ordinary way using "configure" and "make".

0. Check that you have installed all the prerequisites listed above in
   the Base Prerequisites section.  If you want to compile the Linux
   kernel module, also check that the prequisites listed under
   Kernel-Based Switch Prequisites are installed.

1. In the top source directory, configure the package by running the
   configure script.  You can usually invoke configure without any
   arguments:

      % ./configure

   To use a specific C compiler for compiling OpenFlow user programs,
   also specify it on the configure command line, like so:

      % ./configure CC=gcc-4.2

   To build the Linux kernel module, so that you can run the
   kernel-based switch, add --with-l26 or --with-l24 option, or both,
   to the configure script's command line.  Refer to Building the
   Linux Kernel-Based Switch, below, for more information.

   The configure script accepts a number of other options and honors
   additional environment variables.  For a full list, invoke
   configure with the --help option.

2. Run make in the top source directory: 

      % make

   The following binaries will be built:

      - Userspace datapath: udatapath/udatapath.

      - Secure channel executable: secchan/secchan.

      - Controller executable: controller/controller.

      - Datapath administration utility: utilities/dpctl.

      - Runtime logging configuration utility: utilities/vlogconf.

      - Miscellaneous utilities: utilities/ofp-discover,
        utilities/ofp-kill.

      - Tests: various binaries in tests/.

   If your distribution includes the OpenFlow extensions, the
   following additional binaries will be built:

      - ANSI terminal support for EZIO 16x2 LCD panel:
        ext/ezio/ezio-term.

      - Switch monitoring UI for small text displays:
        ext/ezio/ofp-switchui.

   If you passed --with-l26 to configure, "make" will also build the
   following kernel modules:

      - datapath/linux-2.6/openflow_mod.ko

      - datapath/linux-2.6/hwtable_<table>_mod.ko for each <table>
        specified on --enable-hw-tables (if any).

   If you passed --with-l24 to configure, "make" will also build the
   following kernel modules:

      - datapath/linux-2.4/openflow_mod.o      

      - datapath/linux-2.6/hwtable_<table>_mod.o for each <table>
        specified on --enable-hw-tables (if any).

3. Run "make install" to install the executables and manpages into the
   running system, by default under /usr/local.

4. If you built kernel modules, you may load them with "insmod", e.g.:

      (Linux 2.6)
      % insmod datapath/linux-2.6/openflow_mod.ko

      (Linux 2.4)
      % insmod datapath/linux-2.4/compat24_mod.o
      % insmod datapath/linux-2.4/openflow_mod.o

   After you load the openflow module, you may load one hardware switch
   table module (if any were built) to enable support for that hardware
   switching table.

   The insmod program must be run as root.  You may need to specify a
   full path to insmod, e.g. /sbin/insmod.  To verify that the modules
   have been loaded, run "/sbin/lsmod" and check that openflow_mod is
   listed.

4. Test the userspace programs, as described under Testing Userspace
   Programs below.

5. If you built the kernel module, test the kernel-based switch, as
   described under Testing the Kernel-Based Implementation below.

Building the Linux Kernel-Based Switch
--------------------------------------

To build the kernel module, follow the build process described above,
but pass the location of the kernel build directory as an additional
argument to the configure script, as described under step 1 in that
section.  Specify the location on --with-l26 for Linux 2.6, --with-l24
for Linux 2.4.  For example, to build for a running instance of Linux
2.6:

      % ./configure --with-l26=/lib/modules/`uname -r`/build

To build for a running instance of Linux 2.4:

      % ./configure --with-l24=/lib/modules/`uname -r`/build

If you wish to build OpenFlow for an architecture other than the
architecture used for compilation, you may specify the kernel
architecture string using the KARCH variable when invoking the
configure script. For example, to build OpenFlow for MIPS with Linux
2.4:

      % ./configure --with-l24=/path/to/linux-2.4 KARCH=mips

If you have hardware that supports accelerated OpenFlow switching, and
you have obtained a hardware table module for your hardware and
extracted it into the OpenFlow reference distribution source tree,
then you may also enable building support for the hardware switching
table with --enable-hw-tables.  For example, if your hardware
switching table is in a directory named datapath/hwtable-foomatic, you
could compile support for it with the running Linux 2.6 kernel like
so:

      % ./configure --with-l26=/lib/modules/`uname -r`/build \
                    --enable-hw-tables=foomatic

For more information about hardware table modules, please read
README.hwtables at the root of the OpenFlow distribution tree.

Building Debian Packages
========================

Follow these instructions to build Debian packages for OpenFlow.

0. Check that you have installed all the prerequisites listed above in
   the Base Prerequisites and Debian Prerequisites sections above.

1. In the top source directory, run the following command, as root:

      % dpkg-buildpackage

   Alternatively, if you installed the "fakeroot" package, you may run
   dpkg-buildpackage as an ordinary user with the following syntax:

      % dpkg-buildpackage -rfakeroot

   The following packages will be built in the directory above the
   source tree:

      - openflow-controller: The OpenFlow controller.  Depends on
        openflow-pki (see below).

      - openflow-switch: Install this package on a machine that acts
        as an OpenFlow kernel switch.

      - openflow-datapath-source: Source code for OpenFlow's Linux
        kernel module.

      - openflow-pki: Public-key infrastructure for OpenFlow.  Install
        this package on a machine that acts as an OpenFlow PKI server
        (see "Establishing a Public Key Infrastructure" below).

      - openflow-common: Files and utilities required by more than one
        of the above packages.

2. To set up an OpenFlow controller, install the openflow-controller
   package and its dependencies.  You may configure it by editing
   /etc/default/openflow-controller, e.g. to enable non-SSL
   connections, which are disabled by default.  If you change the
   default settings, you will need to restart the controller by
   running:

      % /etc/init.d/openflow-controller restart

3. To set up an OpenFlow switch, install the openflow-switch package
   and its dependencies.  If it is to be a kernel-based switch, also
   install openflow-datapath-source, then follow the instructions in
   /usr/share/doc/openflow-datapath-source/README.Debian to build and
   install the kernel module.

   You may configure the switch one of the following ways:

      - Completely by hand, as described under the Testing section
        below.

        For the userspace datapath-based switch, this is the only
        supported form of configuration.

      - By editing /etc/default/openflow-switch.  You must at least
        configure some network devices, by uncommenting NETDEVS and
        adding the appropriate devices to the list, e.g. NETDEVS="eth0
        eth1".

        After you edit this file, you will need to start the switch by
        running:

           % /etc/init.d/openflow-switch restart

        This form of configuration is not supported for the userspace
        datapath-based switch.

      - By running the ofp-switch-setup program.  This interactive
        program will walk you through all the steps of configuring an
        OpenFlow switch, including configuration of SSL certificates.
        Run it without arguments, as root:

           % ofp-switch-setup

        This form of configuration is not supported for the userspace
        datapath-based switch.

Testing
=======

The following sets of instructions show how to use the OpenFlow
reference implementation as a switch on a single machine.  This can be
used to verify that the distribution built properly.  For full
installation instructions, refer to the Installation section below.

Userspace Datapath
------------------

These instructions use the OpenFlow userspace datapath ("udatapath").

1. Start the OpenFlow controller running in the background, by running
   the "controller" program with a command like the following:

      # controller punix:/var/run/controller.sock &

   This command causes the controller to bind to the specified Unix
   domain socket, awaiting connections from OpenFlow switches.  See
   controller(8) for details.

   The "controller" program does not require any special privilege, so
   you do not need to run it as root.
   
2. The commands below must run as root, so log in as root, or use a
   program such as "su" to become root temporarily.

3. Create a datapath instance running in the background.  The command
   below creates a datapath that listens for connections from secchan
   on a Unix domain socket located in /var/run and services physical
   ports eth1 and eth2:

      # udatapath punix:/var/run/dp0.sock -i eth1,eth2 &

4. Run secchan to start the secure channel connecting the datapath and
   the controller:

      # secchan unix:/var/run/controller.sock unix:/var/run/dp0.sock &
   
5. Devices plugged into the network ports specified in step 2 should
   now be able to send packets to each other, as if they were plugged
   into ports on a conventional Ethernet switch.

Installation
============

This section explains how to install OpenFlow in a network with one
controller and one or more switches, each of which runs on a separate
machine.  Before you begin, you must decide on one of two ways for
each switch to reach the controller over the network:

      - Use a "control network" that is completely separate from the
        "data network" to be controlled ("out-of-band control").  The
        location of the controller must be configured manually in this
        case.

      - Use the same network for control and for data ("in-band
        control").  When in-band control is used, the location of the
        controller may be configured manually or discovered
        automatically.  We will assume manual configuration here;
        please refer to secchan(8) for instructions on setting up
        controller discovery.  

Controller Setup
----------------

On the machine that is to be the OpenFlow controller, start the
"controller" program listening for connections from switches on TCP
port 6633 (the default), as shown below.

   # controller -v ptcp:

(See controller(8) for more details)

Make sure the machine hosting the controller is reachable by the
switch.

Userspace Datapath-Based Setup
------------------------------

On a machine that is to host an OpenFlow userspace datapath-based
switch, follow the procedure below.

0. The commands below must run as root, so log in as root, or use a
   program such as "su" to become root temporarily.

1. Create a datapath instance running in the background.  The command
   below creates a datapath that listens for connections from secchan
   on a Unix domain socket located in /var/run, services physical
   ports eth1 and eth2, and creates a TAP network device named "tap0"
   for use in in-band control:

      # udatapath punix:/var/run/dp0.sock -i eth1,eth2 --local-port=tap:tap0 &

   (See udatapath(8) for details.)

   If the switch will connect to the controller out-of-band, then the
   --local-port option may be omitted, or --no-local-port may be
   substituted.

3. Arrange so that the switch can reach the controller over the
   network.

      - If you are using out-of-band control, at this point make sure
        that the switch machine can reach the controller over the
        network.

      - If you are using in-band control with manual configuration, at
        this point the TAP network device created in step 1 is not
        bridged to any physical network, so the next step depends on
        whether connectivity is required to configure the device's IP
        address:

           * If the switch has a static IP address, you may configure
             its IP address now, e.g.:

                # ifconfig tap0 192.168.1.1

           * If the switch does not have a static IP address, e.g. its
             IP address is obtained dynamically via DHCP, then proceed
             to step 4.  The DHCP client will not be able to contact
             the DHCP server until the secure channel has started up.

      - If you are using in-band control with controller discovery, no
        configuration is required at this point.  You may proceed to
        step 4.

4. Run secchan to start the secure channel connecting the datapath to
   a remote controller.  If the controller is running on host
   192.168.1.2 port 6633 (the default port), the secchan invocation
   would look like this:

      # secchan unix:/var/run/dp0.sock tcp:192.168.1.2

   - If you are using in-band control with controller discovery, omit
     the second argument to the secchan command.

   - If you are using out-of-band control, add --out-of-band to the
     command line.

5. If you are using in-band control with manual configuration, and the
   switch obtains its IP address dynamically, then you may now obtain
   the switch's IP address, e.g. by invoking a DHCP client.  The
   secure channel will only be able to connect to the controller after
   an IP address has been obtained.

6. The secure channel should connect to the controller within a few
   seconds.  It may take a little longer if controller discovery is in
   use, because the switch must then also obtain its own IP address
   and the controller's location via DHCP.

Testing the Kernel-Based Implementation
---------------------------------------

The OpenFlow kernel module must be loaded, as described under
"Building Conventionally", before it may be used.

0. The commands below must run as root, so log in as root, or use a
   program such as "su" to become root temporarily.

1. Create a datapath instance.  The command below creates a datapath
   identified as nl:0 (see dpctl(8) for more detailed usage
   information).

      # dpctl adddp nl:0
   
   (nl:0 is the first datapath within a host.  openflow_mod supports
   multiple datapaths within the same host, which would be identified
   as nl:1, nl:2, etc.)

   Creating datapath nl:0 also creates a new network device named of0.
   This network device, called the datapath's "local port", will be
   bridged to the physical switch ports by the secchan, for use in
   in-band control.

   If you built a support module for hardware accelerated OpenFlow
   switching and you want to use it, you must load it before creating
   the datapath with "dpctl adddp".

2. Use dpctl to attach the datapath to physical interfaces on the
   machine.  Say, for example, you want to create a trivial 2-port
   switch using interfaces eth1 and eth2, you would issue the following
   commands:

      # dpctl addif nl:0 eth1
      # dpctl addif nl:0 eth2

   You can verify that the interfaces were successfully added by asking
   dpctl to print the current status of datapath nl:0:

      # dpctl show nl:0

3. Arrange so that the switch can reach the controller over the
   network.

      - If you are using out-of-band control, at this point make sure
        that the switch machine can reach the controller over the
        network.

      - If you are using in-band control, then at this point you must
        configure the of0 network device created in step 1.  This
        device is not yet bridged to any physical network (because
        secchan does that, and it is not yet running), so the next
        step depends on whether connectivity is required to configure
        the device's IP address:

           * If the switch has a static IP address, you may configure
             its IP address now, e.g.:

                # ifconfig of0 192.168.1.1

           * If the switch does not have a static IP address, e.g. its
             IP address is obtained dynamically via DHCP, then proceed
             to step 4.  The DHCP client will not be able to contact
             the DHCP server until the secure channel has started up.

      - If you are using in-band control with controller discovery, no
        configuration is required at this point.  You may proceed to
        step 4.

4. Run secchan to start the secure channel connecting the datapath to
   a remote controller.  If the controller is running on host
   192.168.1.2 port 6633 (the default port), the secchan invocation
   would look like this:

      # secchan nl:0 tcp:192.168.1.2

   - If you are using in-band control with controller discovery, omit
     the second argument to the secchan command.

   - If you are using out-of-band control, add --out-of-band to the
     command line.

5. If you are using in-band control with manual configuration, and the
   switch obtains its IP address dynamically, then you may now obtain
   the switch's IP address, e.g. by invoking a DHCP client.  The
   secure channel will only be able to connect to the controller after
   an IP address has been obtained.

6. The secure channel should connect to the controller within a few
   seconds.  It may take a little longer if controller discovery is in
   use, because the switch must then also obtain its own IP address
   and the controller's location via DHCP.

Configuration
=============

Secure operation over SSL
-------------------------

The instructions above set up OpenFlow for operation over a plaintext
TCP connection.  Production use of OpenFlow should use SSL[*] to
ensure confidentiality and authenticity of traffic among switches and
controllers.  The source must be configured with --enable-ssl=yes to
build with SSL support.

To use SSL with OpenFlow, you must set up a public-key infrastructure
(PKI) including a pair of certificate authorities (CAs), one for
controllers and one for switches.  If you have an established PKI,
OpenFlow can use it directly.  Otherwise, refer to "Establishing a
Public Key Infrastructure" below.

To configure the controller to listen for SSL connections on port 6633
(the default), invoke it as follows:

      # controller -v pssl: --private-key=PRIVKEY --certificate=CERT \
            --ca-cert=CACERT

where PRIVKEY is a file containing the controller's private key, CERT
is a file containing the controller CA's certificate for the
controller's public key, and CACERT is a file containing the root
certificate for the switch CA.  If, for example, your PKI was created
with the instructions below, then the invocation would look like:

      # controller -v pssl: --private-key=ctl-privkey.pem \
            --certificate=ctl-cert.pem --ca-cert=pki/switchca/cacert.pem

To configure a switch to connect to a controller running on port 6633
(the default) on host 192.168.1.2 over SSL, invoke secchan as follows:

      # secchan -v DATAPATH ssl:192.168.1.2 --private-key=PRIVKEY \
            --certificate=CERT --ca-cert=CACERT

where DATAPATH is the datapath to connect to (e.g. nl:0 or
unix:/var/run/dp0.sock), PRIVKEY is a file containing the switch's
private key, CERT is a file containing the switch CA's certificate for
the switch's public key, and CACERT is a file containing the root
certificate for the controller CA.  If, for example, your PKI was
created with the instructions below, then the invocation would look
like:

      # secchan -v DATAPATH ssl:192.168.1.2 --private-key=sc-privkey.pem \
            --certificate=sc-cert.pem --ca-cert=pki/controllerca/cacert.pem

[*] To be specific, OpenFlow uses TLS version 1.0 or later (TLSv1), as
    specified by RFC 2246, which is very similar to SSL version 3.0.
    TLSv1 was released in January 1999, so all current software and
    hardware should implement it.

Establishing a Public Key Infrastructure
----------------------------------------

If you do not have a PKI, the ofp-pki script included with OpenFlow
can help.  To create an initial PKI structure, invoke it as:
      % ofp-pki init
which will create and populate a new PKI directory.  The default
location for the PKI directory depends on how the OpenFlow tree was
configured (to see the configured default, look for the --dir option
description in the output of "ofp-pki --help").

The pki directory contains two important subdirectories.  The
controllerca subdirectory contains controller certificate authority
related files, including the following:

    - cacert.pem: Root certificate for the controller certificate
      authority.  This file must be provided to secchan with the
      --ca-cert option to enable it to authenticate valid controllers.

    - private/cakey.pem: Private signing key for the controller
      certificate authority.  This file must be kept secret.  There is
      no need for switches or controllers to have a copy of it.

The switchca subdirectory contains switch certificate authority
related files, analogous to those in the controllerca subdirectory:

    - cacert.pem: Root certificate for the switch certificate
      authority.  This file must be provided to the controller program
      with the --ca-cert option to enable it to authenticate valid
      switches.

    - private/cakey.pem: Private signing key for the switch
      certificate authority.  This file must be kept secret.  There is
      no need for switches or controllers to have a copy of it.

After you create the initial structure, you can create keys and
certificates for switches and controllers with ofp-pki.  To create a
controller private key and certificate in files named ctl-privkey.pem
and ctl-cert.pem, for example, you could run:
      % ofp-pki req+sign ctl controller
ctl-privkey.pem and ctl-cert.pem would need to be copied to the
controller for its use at runtime (they could then be deleted from
their original locations).  The --private-key and --certificate
options of controller, respectively, would point to these files.

Analogously, to create a switch private key and certificate in files
named sc-privkey.pem and sc-cert.pem, for example, you could run: 
      % ofp-pki req+sign sc switch
sc-privkey.pem and sc-cert.pem would need to be copied to the switch
for its use at runtime (they could then be deleted from their original
locations).  The --private-key and --certificate options,
respectively, of secchan would point to these files.

Bug Reporting
-------------

Please report problems to: 
info@openflowswitch.org