The Multipath TCP Daemon - mptcpd
- is a daemon for Linux based
operating systems that performs multipath
TCP path
management
related operations in the user space. It interacts with the Linux
kernel through a generic netlink connection to track per-connection
information (e.g. available remote addresses), available network
interfaces, request new MPTCP subflows, handle requests for subflows,
etc.
mptcpd
is built in much the same way most
Autotool-enabled
software packages are built. This includes the build approach for both
clones of the mptcpd
Git repository and self-contained mptcpd
release tar
archive (e.g. mptcpd-0.1.tar.gz
).
Build dependencies for mptcpd
vary depending on whether or not you
are building from a self-contained maintainer generated mptcpd
tar
archive or from a cloned Git mptcpd
repository, for example.
- Basic
mptcpd
Build Dependencies- C compiler (C99 compliant)
- Embedded Linux Library >= v0.27
- Argp library (either the GNU libc built-in or standalone)
- Linux kernel MPTCP user API headers
- pkg-config
- Additional Build Dependencies for Maintainers, and
mptcpd
Git Repository Clones- GNU Autoconf
- GNU Automake
- GNU Libtool
- GNU Autoconf Archive
- Pandoc >= 2.2.1 (needed to convert
README.md
contents from the GitHub markdown format content to plain text) - Doxygen (only needed to build documentation)
Bootstrapping the mptcpd
source distribution is only necessary when
building a clone of the mptcpd
Git repository for the first time, or
possibly after making modifications to the mptcpd
build
infrastructure (e.g. configure
Makefile
, etc). There is no need
to bootstrap self-contained mptcpd
releases generated by the
canonical make dist
command.
Assuming all maintainer related build dependencies listed above are
installed, bootstrapping mptcpd
simply requires running the
bootstrap
script in the top-level source directory, e.g.:
$ ./bootstrap
Move on to the common build steps below once bootstrapping is complete.
mptcpd
shares the usual build procedure found in all Autotool
enabled software packages, i.e. running the configure
script in the
desired build directory, and running make
afterward:
./configure
make
or for an alternate build directory:
mkdir the_build
cd the_build
../configure
make
Run configure --help
to list all command line build configuration
options. Further generic configuration and build details may be found
in the INSTALL
file.
Unit tests included in the mptcpd
source distribution may be run
like so:
./configure
make check
Once again, these steps may be performed in an alternate build directory.
Whether or not debugging support (e.g. debug symbols) is compiled by
default into mptcpd
binaries depends on how the mptcpd
source was
obtained, i.e. as a cloned git
repository or as a "released" tar
archive. It boils downs to the existence of a ".git
" directory in
the top level mptcpd
source directory. Debug symbols will be
enabled and optimization disabled by default if such a directory
exists, and vice versa if doesn't exist. The default behavior may be
overriden by using the --enable-debug
configuration option:
--enable-debug=[yes/info/profile/no]
compile with debugging
The usual build flags, such as CFLAGS
, LDFLAGS
, etc, may be
provided on the configure
script command line. See the output from
./configure --help
, or the INSTALL
file, for additional details.
To aid with identifying areas of the mptcpd
code that are or are not
exercised by its unit tests or when deployed, mptcpd
may be
instrumented for code coverage when it is built with GCC. Code
coverage reports will also require the tools gcov
, lcov
and
genhtml
to be installed as well.
To enable mptcpd
code coverage instrumentation, and generate reports
from unit tests in the top level source directory, for example, build
mptcpd
like so:
./configure --enable-code-coverage
make check-code-coverage
The location of the HTML formatted code coverage results will be displayed after the report is generated.
HTML formatted code documentaton for mptcpd
may be generated if
Doxygen is installed by running the doxygen-doc
make
target, e.g.:
./configure
make doxygen-doc
Generated documentation will be placed in the doc/html
directory.
PostScript and PDF formatted documentation generation is disabled by
default but may be explicitly generated using the doxygen-ps
and
doxygen-pdf
make
targets.
Additional Doxygen based documentation generation options are
described in the configure
script help output (e.g. ./configure --help
).
The mptcpd
source package provides the same installation related
make
targets found in most GNU style and Autotool enabled software
packages. The most basic way to install mptcpd
is:
make install
By default mptcpd
will be installed in appropriate directories under
the directory /usr/local
. Fine tuning of installation directories
may be done using several configure
script command line options.
See the help output from ./configure --help
as well as the INSTALL
file for details.
Super user (root
) permissions may be necessary if installing into
directories owned by root
.
If systemd
is detected a service
file
will be installed in the appropriate location
(e.g. /lib/systemd/system
). That installation directory is
independendent of the default directories mentioned above. If
necessary, the systemd service file installation directory may be
changed using the following configure
script command line option.
--with-systemdsystemunitdir=DIR
Directory for systemd service files
mptcpd
may be started in a number of ways depending on whether or
not systemd
is used to run installed binaries, or if it is run
directly from the source tree (e.g. when debugging development
versions) without installation.
mptcpd
currently does not provide traditional System V "init
scripts". In general the mptcpd
program may be run directly from
the installed directory, e.g.:
/usr/bin/mptcpd
However, it may be necessary to explicitly set the library load path
through the LD_LIBRARY_PATH
environment path if mptcpd
is
installed in a set of directories unknown to the dynamic linker, e.g.:
LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH /usr/local/bin/mptcpd
or:
# Assumes Bourne shell style environment variable assignment.
export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH
/usr/local/bin/mptcpd
Alternatively, update the dynamic linker run-time bindings by running
ldconfig
after installation
of mptcpd
.
NOTE: mptcpd
requires the CAP_NET_ADMIN
capability to be fully
functional. If not using the provided systemd
service file
mptcp.service
, the necessary capability may be
granted to mptcpd
by any of the following:
- Run as
root
(generally not desirable) - Run with a wrapper such as,
capsh
- Attach the required capabilities to the installed
mptcpd
executable throughsetcap
To start mptcpd
immediately after installation using systemd
run
the following commands:
systemctl daemon-reload
systemctl start mptcp.service
These steps are not necessary if the system is rebooted after
installation of mptcpd
.
Since mptcpd
is built with libtool
support it is generally best to
execute mptcpd
using libtool
. For example, to run mptcpd
under
the gdb
debugger one could do the following, assuming mptcpd
was
configured and built from the top level source directory:
./libtool --mode=execute gdb ./src/mptcpd