README

Content-Centric Networking CCNx Reference Implementation
========================================================

The CCNx reference implementation provides the libraries and components
required to build and run applications that use and demonstrate the
basic CCNx protocols for experimental and research purposes.

The protocol specifications and the reference implementation are at an
early research stage of development, and are released to enable
collaboration with researchers.  What is provided at this time is pure
infrastructure, with no applications of interest.  Documentation is
also minimal, and so using the release software will require technical
sophistication and a willingness to read the code.

This work is free software; you can redistribute it and/or modify it under
the terms of the appropriate licenses as covered in the file LICENSE
and noted in each source file.

This software is distributed in hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the file
LICENSE for more information.

* Please see the file LICENSE for important licensing details and limitations.
* Please see the file NOTICES for important notices.

For more information about Project CCNx, see our website at http://www.ccnx.org.

This file provides introductory information in the following sections:

1. Package contents
2. Supported platforms and development tools
3. Build and install instructions
4. Running the programs
5. Runtime files
6. Support and contact information

README files in other directories provide platform and application-specific
notes and instructions.  Top-level examples include the following:

    android/README.build
    csrc/README.cygwin
    csrc/README.darwin
    csrc/README.freebsd
    csrc/README.linux
    csrc/README.netbsd
    csrc/README.solaris
    csrc/ccnd/README
    doc/manpages/README


## 1. Package contents ##

This distribution includes the following things:

A. Preliminary specifications of CCNx protocol, application protocols
   and conventions.

B. C/POSIX reference implementation of CCNx forwarder, repository
   (persistent stroage of CCNx data, with synchronization), library,
   primitive utilities, skeleton API docs, and unit test suite.  The C
   implementation is required for all CCNx communication.

C. Java reference implementation of library including primitive
   utilities, skeleton API docs, and unit test suite.  The Java
   library has more functionality implemented or started than the C
   library and may be an easier place to start experimenting.

D. Minimal sample app (ccnChat) to demonstrate basic communication on
   local LAN.

E. Minimal sample file proxy (ccnFileProxy) to demonstrate basic
   communication on local LAN.

F. Experimental plugins for vlc (media transport) and wireshark
   (packet dissector)

G. An Android implementation for smartphones.  The Android implementation
   has a service wrapper for ccnd and the repository.  It also has
   a CCN Chat implementation.

Documentation is built from source files of various kinds (using a
combination of doxygen and asciidoc) BUT the distribution includes pre-built
documentation so it is not necessary to have a build environment and
toolchain configured to start reading. Point your browser at
`doc/index.html` to get started.

The file tree is organized as follows:

* `README` - this file
* `LICENSE` - license terms that apply to the distribution
* `MANIFEST` - listing of every file in the distribution
* `MD5` - MD5 sum for every file in the distribution
* `NEWS` - release notes
* `NOTICES` - CCNx notices
* `SHA1` - SHA1 sum for every file in the distribution
* `configure` - master configure script.  Note that configure scripts are
       hand-written at this time, not generated by autoconf
* `android/` - The Android implementation
* `android/apps` - Android applications that use CCNx
* `android/apps/CCNx-Android-Chat` - The CCNx Chat application for Android
* `android/CCNx-Android-Lib` - A common Android Library for working with CCNx
* `android/CCNx-Android-Services` - Wrappers for ccnd and repository
* `android/external` - External libraries needed for ARM
* `apps` - experimental/sample apps tree
* `apps/ccnChat` - simple text chat sample in Java
* `apps/ccnFileProxy` - simple proxy making local files available via CCNx
* `apps/examples` - small example programs and code snippets
* `apps/HttpProxy` - sample HTTP proxy that converts HTTP Gets to CCN interests
* `apps/vlc` - vlc plugin for media transport experiments
* `apps/wireshark` - wireshark plugin dissector for decoding CCNx packets
* `csrc/` - C code tree
* `csrc/ccnd` - CCN daemon, the user-space forwarder implementation
* `csrc/ccnr` - repository daemon, for persistent storage of content
* `csrc/cmd` - simple command-line utilities
* `csrc/conf` - OS-specific configuration scripts etc.
* `csrc/contrib` - third-party library needed for certain platforms that
       are POSIX-deficient
* `csrc/include/ccn` - C header files
* `csrc/lib` - C application library implementation
* `csrc/libexec` - connectivity utilities, especially ccndc, the ccnd
       configurator and connectivity agent
* `csrc/rc` - sample rc scripts for automatic daemon startup
* `csrc/sync` - sync protocol implementation
* `csrc/tests` - C test suite
* `csrc/util` - launch script support
* `doc/` - documentation tree
* `doc/android` - API documentation generated from Java code for Android
* `doc/ccode` - API documentation generated from C code
* `doc/javacode` - API documentation generated from Java code
* `doc/manpages` - CCNx man pages
* `doc/technical` - specifications
* `experiments/multicast` - scripts for running multi-machine experiments in content
       distribution performance over local multicast group.
* `javasrc/` - Java code tree.  The usual Java conventions are used for mapping
       package names to the file tree, with root package [org.ccnx.ccn](org.ccnx.ccn).
* `javasrc/lib` - third-party libraries
* `javasrc/src` - Java source tree
* `javasrc/tools` - convenience scripts
* `schema` - XML schema and DTD files
* `vendor` - unmodified copies of included third-party code

After building, the following notable directories will appear:

* `bin/` - command-line tools you can run, providing convenience access to
  mixture of C and Java utilities and samples
* `lib/` - all libraries needed for applications (both C and Java)
* `include/` - headers needed for applications in C
* `javasrc/build` - Java build outputs from ant (`javasrc/bin` is equivalent
       for Eclipse)

Note that these directories are entirely generated and will be removed
by some clean targets, so don't use them for anything you want to keep.


## 2. Supported platforms ##

__OS PLATFORMS__

Only Unix-like platforms are currently supported.  CCNx code is tested
on Ubuntu Linux, MacOS, Solaris, and FreeBSD.  Some packaging for
Cygwin is currently provided but is not fully supported and there is
no other support for Windows platforms yet.

Android is supported in the `android/` tree.  It only introduces minimal
new code specific to the Android platform and otherwise re-uses the
existing CCNx C and Java code.

__C LANGUAGE REQUIREMENTS AND TOOLS__

For parts of the system written in C, you will require a standard
toolchain including gcc, make. etc. and the following libraries which
are not included in the distribution.

* libcrypto >= 0.9.8 from openssl available from http://openssl.org/source/
* expat available from http://sourceforge.net/projects/expat/
* libpcap available from http://www.tcpdump.org
     (optional, needed for certain utilities only)
*  libxml2 available from xmlsoft.org

In addition, you will need vlc and wireshark to build and use the CCNx
plugins for those packages.  Please see the individual README files
for more information.

See `csrc/README*` files for further notes about what needs to be installed or
configured on each OS.

__JAVA LANGUAGE REQUIREMENTS AND TOOLS__

For parts of the system written in Java, CCNx code is tested with
Java JDK 1.6 and 1.7 only, with ant used as the canonical build tool.
You will need:

* ant (>= 1.8.2 tested, download latest version from: http://ant.apache.org/bindownload.cgi)

Eclipse `.project` and `.classpath` files are included in the distribution
so you can create Eclipse projects easily that will resolve
dependencies correctly.  There are three Eclipse Java projects
defined: one in `javasrc` (Eclipse project name `CCNx-Java`) and one each
in `apps/ccnChat` (Eclipse project name `ccnChat`) and `apps/ccnFileProxy`
(Eclipse project name `ccnFileProxy`).  To import one of these projects
into your Eclipse workspace, choose File/Import... from the menu, open
the General category in the Import dialog and select "Existing
Projects into Workspace".  Type in (or browse to) the appropriate
directory and you should see the named Project listed and selected so
you can click Finish to complete the import.

__SPECIAL PLATFORM NOTES__

_Solaris_

You will need to use gmake rather than make.

_Android_

Please see `android/README` for special notes about Android.

_Ubuntu_

As a result of Sun Java JDK packages being removed for Ubuntu (see
https://lists.ubuntu.com/archives/ubuntu-security-announce/2011-December/001528.html), we are now using OpenJDK for Ubuntu. Please see csrc/README.linux
for more information.


## 3. Build and install instructions ##

Note that the overall build handles both the C and Java code,
so you will need to have requirements for both met in order
to avoid errors.  See the section above. See `android/README.build`
for information on building for Android.

__BUILDING__

In the root directory:

    ./configure
    make

The top-level build will compile both C and Java code, but
not Android code.  The above is sufficient to run programs
locally out of `bin/` and build apps referencing `lib/` and `include/`.

For users of Maven, it is now possible to build the javasrc.  From the
top-level:

    mvn clean package

will produce a library, javadocs, and sources in separate jar files
under javasrc/target.  This is provided as a convenience for users of
the Maven ecosystem of tools.  The Maven build does not support the
full suite of tests yet.

__TESTING__

To run the complete test suite (both C and Java):

    make test

__MACHINE INSTALL (OPTIONAL)__

To install to a standard location on your machine you may also use

    make install

__FURTHER DOCUMENTATION__

See the notes in the Content-Centric Networking in C in the top-level
documentation.


## 4. Running the programs ##

These notes assume that you have performed the build steps listed
above, but not performed a machine install.  Everything may be run
directly out of the build tree using programs in `bin/`.

__CCND__

All CCNx programs require that a ccnd be running:

    bin/ccndstart

To start ccnd sending output to a log file instead of the terminal,
set the `CCND_LOG` environment variable with the path of the file you
want to write.  Any existing file with that name will be overwritten.

For a listing of other environment variables that are available
(including debug message controls) run:

    bin/ccnd -h

Note that you should not ordinarily run ccnd directly, but use the
ccndstart script.

For experiments on one machine it is sufficient to have a ccnd running
without using a ccnd configuration file, however for multiple machine
experimentation you will need to use ccndc to configure the inter-machine
forwarding of interest/content.

If a `$HOME/.ccnx/ccnd.conf` file is present then ccndstart will execute

    ccndc -f $HOME/.ccnx/ccnd.conf

For a sample file, see `csrc/libexec/ccnd.conf.sample`

__REPOSITORY__

The repository provides persistent storage of CCNx content backed by a
file system, and responds to interests in the content it has available.

Start a repository with the `CCNR_DIRECTORY` environment variable set to
the fully qualified pathname of the repository file directory.

    bin/ccnr

The directory named by `CCNR_DIRECTORY` must exist already.
To start ccnr as a daemon, redirect stderr to a file and execute

    bin/ccnr &

ccnr shuts down gracefully if it receives `SIGINT` or `SIGTERM`, or if the
ccnd to which it is connected is shut down.

Do not run two repositories on the same backing store directory at the
same time.

It is sometimes helpful to get a list of the names of stored content held
by a repository.  To do this, use

    ccnnamelist $CCNR_DIRECTORY/repoFile1

A configuration file in `$CCNR_DIRECTORY/config` and/or environment
variables can be used to control some settings. Most important is probably
the `CCNR_GLOBAL_PREFIX` parameter, which is a namespace for
configuration information about this repository that is expected by
convention to be globally unique and meaningful, rather than only locally
unique and contextually meaningful.

    bin/ccnr -h

gives configuration options.  For more information about repository
configuration, see the ccnr man page at `doc/manpages/ccnr.html`.

A policy file specifies the namespaces for which the repository accepts
and holds content. The name of the policy file is the concatenation of
the global prefix and "`data/policy.xml`". The actual encoding of the
files is in ccnb form, and it must be stored in the repository to take
effect. Unless an alternative policy has been explicitly
written/published under the policy information name, the
the policy defaults to `/`, which means that writes will be accepted for
any name and reads serviced for any name for which there is content.
The command `ccnrpolicyedit` may be used to edit the policy.
For more information about policies, see `doc/technical/RepoPolicies.html`.

__UTILITIES__

There are a variety of simple utilities in `bin/`.  Some of them have
usage messages, but the handling of arguments and usage messages is
inconsistent as of this release.  Here are a few notable utilities:

* `ccnexplore` - primitive GUI browser in Java, usable to browse only
               repo content since it requires name enumeration support
               available only there.  Also allows writing files to repo.
* `ccnls` - primitive content listing by retrieval
* `ccnlsrepo` - command-line content listing from repo (via name 
                enumeration)
* `ccnputfile` - command-line tool to send file as CCNx data (asks repo
               to receive unless -raw arg given)
* `ccngetfile` - command-line tool to retrieve CCNx content and store it
               in file
* `ccnchat` - the ccnChat sample application
* `ccnfileproxy` - the ccnFileProxy sample application


## 5. Runtime files ##

Beware that running the experimental software will create a variety of
files, and that this list may not be complete:

* `~/.ccnx` - per-user directory, used primarily for personal keystore and
         key cache
* `~/.rmi-server-*` - per-user files Java daemon RMI interface objects.
         These are supposed to be cleared away automatically but that
         does not occur if processes are terminated manually and in
         other cases.

Repository directories are also created if you run a repository, but
in that case you must tell the program what directory to use.


## 6. Support and contact information ##

Support for CCNx is primarily found on the ccnx.org mailing lists.  There
are three lists: ccnx-dev@ccnx.org (For Developers), ccnx-users@ccnx.org
(for Users) and ccnx-interest@ccnx.org (for NEW and Updates).  Find out
more at:
    http://www.ccnx.org/subscribe-to-the-mailing-lists/

Live support can be found in realtime on IRC: #ccnx

Please see our website at http://www.ccnx.org.

## 7. Contributions ##

For developers looking to provide bug fixes, documentation, code samples, or
new features, we recommend first reviewing our process for contributing code
online:
    http://www.ccnx.org/support/contributing-code/

All code contributions and patches will require individuals to sign a
Contributor Agreement.  Individuals representing an organization should
first consult with their own legal departments before singing anything.
Once we have a ratified document, we are free to take in source
contributions.  We strongly recommend using the Fork feature of Github
described here:
    http://help.github.com/fork-a-repo/

When code is ready for review, send a Pull Request, described here:
    http://help.github.com/send-pull-requests/

This process creates a nice dialogue and fosters transparency in the
process.

For organizations interested in contributing large bodies of work, we
recommend contacting the project leads to discuss a Software Grant
Agreement.

If signing a Contributor Agreement is not possible due to organizational
or legal restrictions, there are other ways to get involved, including
contributing interesting code on our WIKI at: https://www.ccnx.org/wiki

## 8. Related Work ##

We are actively interested in promoting and fostering development and
collaboration within the CCNx Community.  If you have something great to
share related to CCNx, built on, forked from, or otherwise of interest to
this Community, please contact us.  We will be looking for ways to publish
community project via http://www.ccnx.org on our WIKI.