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adsb-tools/adsbus/README.md
Ian Gulliver dd9c77cbb6 Test
2016-03-11 15:06:22 -08:00

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# adsbus
adsbus is a hub and protocol translator for [ADS-B](https://en.wikipedia.org/wiki/Automatic_dependent_surveillance_%E2%80%93_broadcast) messages.
It is conceptually similar to `dump1090 --net-only`, but supports more protocols and configurations. It doesn't talk to your radio itself; it
hooks programs that do, then handles the network distribution and format translation. It doesn't output to a web interface or send data to
services like FlightAware; it provides hooks for programs that do.
## Building
```bash
sudo apt-get -y install build-essential git clang libjansson-dev libprotobuf-c-dev protobuf-c-compiler
git clone https://github.com/flamingcowtv/adsb-tools.git
cd adsb-tools/adsbus
make
```
## Features
* Separates the concepts of transport, data flow, and format
* Transports:
* Outgoing TCP connection
* Incoming TCP connection
* Local files, [named pipes](https://en.wikipedia.org/wiki/Named_pipe), and [character devices](https://en.wikipedia.org/wiki/Device_file#Character_devices)
* [stdin/stdout](https://en.wikipedia.org/wiki/Standard_streams)
* Execute a command and talk to its stdin/stdout, proxy logs from its stderr
* Data flows:
* Send (data flows out of adsbus)
* Receive (data flows in to adsbus)
* Send & receive (both directions on the same socket, without echo)
* Formats:
* [airspy_adsb](../protocols/airspy_adsb.md) (a.k.a. ASAVR)
* [beast](../protocols/beast.md)
* [json](../protocols/json.md)
* [proto](../protocols/proto.md) (a.k.a. ProtoBuf, Protocol Buffers)
* [raw](../protocols/raw.md) (a.k.a. AVR)
* stats (send only, summary aggregated data)
* Transport features:
* [IPv4](https://en.wikipedia.org/wiki/IPv4) and [IPv6](https://en.wikipedia.org/wiki/IPv6) support
* Reresolution and reconnection on disconnect, with backoff and jitter
* [TCP keepalives](https://en.wikipedia.org/wiki/Keepalive#TCP_keepalive) for dead connection detection
* [TCP fast open](https://en.wikipedia.org/wiki/TCP_Fast_Open) for faster startup of high-latency connections
* [SO_REUSEPORT](https://lwn.net/Articles/542629/) for zero-downtime updates
* Data flow features:
* Rapid detection and disconnection of receive <-> receive connections
* Less rapid detection and disconnection of send <-> send connections
* Hop counting and limits (json and proto formats only) to stop infinite routing loops
* Format features:
* Autodetection of received data format
* [MLAT](https://en.wikipedia.org/wiki/Multilateration) scaling for different clock rates and counter bit widths
* [RSSI](https://en.wikipedia.org/wiki/Received_signal_strength_indication) scaling for different bit widths
* Introduces json format for balanced human and machine readability with forward compatibility
* Introduces proto format for fast serialization and deserialization with forward compatibility
* Federation:
* Federation allows linking multiple instances of adsbus for:
* Scalability (cores, number of input or output clients, etc.)
* Efficient long-haul links (hub and spoke models on both ends)
* json and proto formats carry information about original source across multiple hops
* SO_REUSEPORT allows multiple adsbus instances to accept connections on the same IP and port without a load balancer
## Use
* As a commandline utility
* For captures from a network source:
<script src="https://gist.github.com/flamingcow66/68f06aaa7ce91b8ad433.js"></script>
## Security, reliability, testing
* Secure build options by default
* -Weverything -Werror -pedantic-errors (with limited specific exceptions)
* [-D_FORTIFY_SOURCE=2](https://wiki.debian.org/Hardening#DEB_BUILD_HARDENING_FORTIFY_.28gcc.2Fg.2B-.2B-_-D_FORTIFY_SOURCE.3D2.29)
* [-fstack-protector-strong](https://wiki.debian.org/Hardening#DEB_BUILD_HARDENING_STACKPROTECTOR_.28gcc.2Fg.2B-.2B-_-fstack-protector-strong.29)
* [-fPIE -pie](https://wiki.debian.org/Hardening#DEB_BUILD_HARDENING_PIE_.28gcc.2Fg.2B-.2B-_-fPIE_-pie.29)
* [-z relro](https://wiki.debian.org/Hardening#DEB_BUILD_HARDENING_RELRO_.28ld_-z_relro.29)
* [-z now](https://wiki.debian.org/Hardening#DEB_BUILD_HARDENING_BINDNOW_.28ld_-z_now.29)
* valgrind clean
* Zero open fds and allocated blocks when run with `--track-fds=yes --show-leak-kinds=all --leak-check=full`
* Cleans up on normal exit and when handling SIGINT/SIGTERM
* Subprogram isolation
* All fds created with CLOEXEC; none passed on to children (tested with `--exec-receive='ls -l /proc/self/fd 1>&2'`)
* Separate process group
* Test suite
* `make test` runs a large set of test inputs through adsbus under valgrind
* Parser fuzzing
* `make afl-fuzz` runs adsbus inside [american fuzzy lop](http://lcamtuf.coredump.cx/afl/) starting from previous output cases
* Network fuzzing
* `stutterfuzz.sh` runs adsbus with [stutterfuzz](https://github.com/flamingcowtv/stutterfuzz) to test connection/network handling under load, using afl test cases