Tests and fuzzers for the native code of PCAPdroid.

The tests are built with the [AddressSanitizer](https://clang.llvm.org/docs/AddressSanitizer.html) to detect memory issues and leaks. They are run as part of the Github workflow.

The fuzzers use [LibFuzzer](https://llvm.org/docs/LibFuzzer.html).

The targets can be run with the provided `Makefile` as follows:

```bash
# Install dependencies
apt install make clang libpcap-dev cmake

# Run the tests
# pcapd log at build/test/test/pcapd.log
make run_tests

# Fuzz the pcapd daemon
FUZZ_OPTS="-jobs=8" make fuzz_pcapd

# Fuzz the pcapdroid capture
FUZZ_OPTS="-jobs=8" make fuzz_capture
```

Cmake `3.18.1` or newer is required. If that's not available for your distribution, you can install it as follows:

```
apt purge cmake

cd /usr
wget https://github.com/Kitware/CMake/releases/download/v3.23.2/cmake-3.23.2-linux-x86_64.sh
chmod +x cmake-3.23.2-linux-x86_64.sh

# answer "n" when prompted to extract in subdir
./cmake-3.23.2-linux-x86_64.sh

# version should now be 3.23.2
cmake --version
```

The following sections describe the PCAP files contained in the `pcap` directory.

## metadata.pcap

Contains HTTP, TLS and DNS connections for both IPv4 and IPv6, suitable to test DPI.

Connections:

```
[UDP4] 192.168.1.10:48037 -> 8.8.8.8:53 [example.org]
[UDP4] 192.168.1.10:38793 -> 8.8.8.8:53 [www.google.com]
[TCP4] 192.168.1.10:36922 -> 216.58.208.164:80 [www.google.com]
[UDP4] 192.168.1.10:48772 -> 8.8.8.8:53 [www.google.com]
[TCP6] 2001:db8:1234::1:49936 -> 385d:1ee:e3c9:9c5f::2004:80 [www.google.com]
[UDP4] 192.168.1.10:51080 -> 8.8.8.8:53 [google.it]
[TCP6] 2001:db8:1234::1:44904 -> 2c9b:a9b9:83dd:d9d1::2003:443 []
[TCP4] 192.168.1.10:51588 -> 142.250.180.131:443 [google.it]
[UDP4] 192.168.1.10:42218 -> 8.8.8.8:53 [www.google.it]
[TCP6] 2001:db8:1234::1:59424 -> 3a5d:15fe:e3cb:9c5f::2003:443 [www.google.it]
[ICMP4] 192.168.1.10:4 -> 1.1.1.1:0 []
[UDP4] 192.168.1.10:47987 -> 8.8.8.8:53 [www.internetbadguys.com]
[TCP4] 192.168.1.10:46312 -> 146.112.255.155:80 [www.internetbadguys.com]
[UDP4] 192.168.1.10:51165 -> 8.8.8.8:53 [www.internetbadguys.com]
[UDP4] 192.168.1.10:52176 -> 8.8.8.8:53 [example.org]
[TCP6] 2001:db8:1234::1:45226 -> 2ed5:9050:81e9:4b68:248:1893:25c8:1946:443 [example.org]
[TCP4] 192.168.1.10:43453 -> 8.8.8.8:53 [f-droid.org]
[UDP4] 192.168.1.10:41011 -> 8.8.8.8:53 [f-droid.org]
[TCP4] 192.168.1.10:52782 -> 149.202.95.241:80 [f-droid.org]
```

## two_flows.pcap

Contains two flows. The first 20 packets of the PCAP are part of the first flow, whereas
the last 29 packets are from the second flow.

```
[TCP4] 192.168.1.10:36922 -> 216.58.208.164:80 [www.google.com]
[TCP4] 192.168.1.10:51588 -> 142.250.180.131:443 [google.it]
```

## invalid_or_unsupported.pcap

Contains packets with invalid or unsupported IP/transport headers.

- Packets with invalid length
- Packet smaller than IP header size
- UDP packet smaller than header size
- Packet with invalid IP version (0)
- Packet with non TCP/UDP/ICMP protocol (CHAOS)
- Packets with IPv6 extensions (OSPF IGP, ESP)
- IP subsequent fragment with first fragment not seen

## crash-*

These files, generated by the fuzzer, caused a crash. They are part of
the seed used by the fuzzer, which ensures no regression occurs.