MAVLink Router

Route mavlink packets between endpoints.

The usual configuration is to have one "master" endpoint that is the flight stack (either on UART or UDP) and other components that can be on UDP or TCP or UART endpoints. This is not strictly required and other configurations are possible: mavlink-router mainly routes mavlink packets from one endpoint to the other endpoints without differentiating what they are.

TCP endpoints are added automatically if the TCP server is enabled, allowing clients to simply connect to mavlink-router without changing its configuration.

Compilation and installation

In order to compile you need the following packages:

• GCC or Clang compiler
• C and C++ standard libraries

Fetch dependencies:

We currently depend on the mavlink C library which is generated by the build system during compilation. The corresponding submodule should be fetched:

$ git submodule update --init --recursive

The following libraries need also to be installed :

$ sudo apt install python-future
$ sudo apt install python3-future
$ sudo apt install libtool
$ sudo apt install autoconf
$ sudo apt install pkg-config
$ sudo apt install libsystemd-dev

Build

The build system follows the usual configure/build/install cycle. Configuration is needed to be done only once. A typical configuration for a 64-bit system is shown below:

$ ./autogen.sh && ./configure CFLAGS='-g -O2' \
    --sysconfdir=/etc --localstatedir=/var --libdir=/usr/lib64 \
    --prefix=/usr

On an 32-bit system use --libdir=/usr/lib instead of --libdir=/usr/lib64.

By default systemd integration is enabled. In a system without systemd it can be disabled with --disable-systemd. The default systemd system directory is taken via pkg-config. To use another directory update the above path, use --with-systemdsystemunitdir.

By default mavlink-router is capable of using IPv6 addresses. In a system without an IPv6 capable kernel, this can be disabled with --disable-ipv6.

Installation location can be changed using the --prefix option while configuring.

Build:

$ make

Install:

$ sudo make install

Or in order to install to another root directory:

$ sudo make DESTDIR=/tmp/root/dir install

Running

To route mavlink packets from master ttyS1 to 2 other UDP endpoints, do as following:

$ mavlink-routerd -e 192.168.7.1:14550 -e 127.0.0.1:14550 /dev/ttyS1:1500000

The 1500000 after the colon in /dev/ttyS1:1500000 sets the UART baudrate. See more options with mavlink-routerd --help.

It's also possible to route mavlinks packets from any interface using:

$ mavlink-routerd -e 192.168.7.1:14550 -e 127.0.0.1:14550  0.0.0.0:24550

mavlink-router also listens, by default, on port 5760 for TCP connections. Any connection there will also receive routed packets.

IPv6 addresses must be enclosed in square brackets like this: [::1]. The port number can be specified in the same way, as with IPv4 then: [::1]:14550.

Conf file

It's also possible to use a .conf file to set options for mavlink-routerd. By default, mavlink-routerd looks for a file /etc/mavlink-router/main.conf. The file location can be overriden via a MAVLINK_ROUTER_CONF_FILE environment variable, or via the -c switch when running mavlink-routerd. An example conf file can be found in examples/config.sample

Conf dirs

Besides the default conf file, it's also possible to use a directory in where to put some extra configuration files. Files in this directory will be read in alphabetical order, and can add or override configurations found in previous files.

By default, /etc/mavlink-router/config.d is the directory, but it can be overriden via a MAVLINK_ROUTER_CONF_DIR environment variable, or via the -d switch when running mavlink-routerd.

Suppose that the default configuration file defines an UartEndpoint bravo using Baud=56600, an example of overriding configuration would be:

[UartEndpoint bravo]
Baud = 115200

That would change Endpoint bravo baudrate to 115200.

Flight stack logging

Mavlink router can also collect flight stack logs. It supports collecting both PX4 and Ardupilot flight stacks logs. To start logging, set a directory to the Log key in the General section in the config file (or use argument option -l). Currently, mavlink router needs to be informed which MAVLink dialect the flight stack speaks, common or ardupilotmega. To define it, use the MavlinkDialect key. For instance, to collect Ardupilot logs to /var/log/flight-stack directory, one could add to the conf file:

[General]
Log=/var/log/flight-stack
MavlinkDialect=ardupilotmega

Logs are collected on .bin (for Ardupilot) or .ulg (for PX4) files in the specified directory. Note that they are named XXXXX-date-time, where XXXXX is an increasing number.

For more information about configuration files, see conf file section.

Contributing

Pull-requests are accepted on GitHub. Make sure to check coding style with the provided script in tools/checkpatch and tools/checkpython, check for memory leaks with valgrind and test on real hardware.

Samples

Directory examples has some samples that can be used to test mavlink-router. Those are Python scripts, and pymavlink is required.

Sender & receiver

One can test mavlink-router by using examples/sender.py and examples/receiver.py to simulate traffic of mavlink messages. First script sends mavlink ping messages to a target mavlink system-id, and second receives and responds to them. For instance:

$ python examples/sender.py 127.0.0.1:3000 100 0

Will send mavlink pings to UDP port 3000. Those pings will have 100 as source system id and will have 0 as target system id (0 means broadcast). Receiver could be set as:

$ python examples/receiver.py 127.0.0.1:4000 50

Where 50 is the receiver system id. Then, to route between those:

$ mavlink-routerd -e 127.0.0.1:4000 0.0.0.0:3000

Note that it's possible to setup multiple senders and receivers to see mavlink-router in action.