This is a huge change to make the various subcomponents of the inlet use
the schema to generate the protobuf. For it to make sense, we also
modify the way we parse flows to directly serialize non-essential fields
to Protobuf.
The performance is mostly on par with the previous commit. We are a bit
less efficient because we don't have a fixed structure, but we avoid
loosing too much performance by not relying on reflection and keeping
the production of messages as code. We use less of Goflow2: raw flow
parsing is still done by Goflow2, but we don't use the producer part
anymore. This helps a bit with the performance as we parse less.
Overall, we are 20% than the previous commit and twice faster than the
1.6.4!
```
goos: linux
goarch: amd64
pkg: akvorado/inlet/flow
cpu: AMD Ryzen 5 5600X 6-Core Processor
BenchmarkDecodeEncodeNetflow
BenchmarkDecodeEncodeNetflow/with_encoding
BenchmarkDecodeEncodeNetflow/with_encoding-12 151484 7789 ns/op 8272 B/op 143 allocs/op
BenchmarkDecodeEncodeNetflow/without_encoding
BenchmarkDecodeEncodeNetflow/without_encoding-12 162550 7133 ns/op 8272 B/op 143 allocs/op
BenchmarkDecodeEncodeSflow
BenchmarkDecodeEncodeSflow/with_encoding
BenchmarkDecodeEncodeSflow/with_encoding-12 94844 13193 ns/op 9816 B/op 295 allocs/op
BenchmarkDecodeEncodeSflow/without_encoding
BenchmarkDecodeEncodeSflow/without_encoding-12 92569 12456 ns/op 9816 B/op 295 allocs/op
```
There was a tentative to parse sFlow packets with gopackets, but the
adhoc parser used here is more performant.
At first, there was a tentative to use BMP collector implementation
from bio-rd. However, this current implementation is using GoBGP
instead:
- BMP is very simple from a protocol point of view. The hard work is
mostly around decoding. Both bio-rd and GoBGP can decode, but for
testing, GoBGP is able to generate messages as well (this is its
primary purpose, I suppose parsing was done for testing purpose).
Using only one library is always better. An alternative would be
GoBMP, but it also only do parsing.
- Logging and metrics can be customized easily (but the work was done
for bio-rd, so not a real argument).
- bio-rd is an application and there is no API stability (and I did
that too)
- GoBGP supports FlowSpec, which may be useful in the future for the
DDoS part. Again, one library for everything is better (but
honestly, GoBGP as a lib is not the best part of it, maybe
github.com/jwhited/corebgp would be a better fit while keeping GoBGP
for decoding/encoding).
There was a huge effort around having a RIB which is efficient
memory-wise (data are interned to save memory), performant during
reads, while being decent during insertions. We rely on a patched
version of Kentik's Patricia trees to be able to apply mutations to
the tree.
There was several tentatives to implement some kind of graceful
restart, but ultimetaly, the design is kept simple: when a BMP
connection goes down, routes will be removed after a configurable
time. If the connection comes back up, then it is just considered new.
It would have been ideal to rely on EoR markers, but the RFC is
unclear about them, and they are likely to be per peer, making it
difficult to know what to do if one peer is back, but not the other.
Remaining tasks:
- [ ] Confirm support for LocRIB
- [ ] Import data in ClickHouse
- [ ] Make data available in the frontend
Fix#52
Raw data files can be converted with Scapy:
```python
from scapy.all import *
wrpcap("data-1140.pcap",
Ether(src="00:53:00:11:22:33",dst="00:53:00:44:55:66")/
IP(src="192.0.2.100", dst="192.0.2.101")/
UDP(sport=47873,dport=6343)/
open("data-1140.data", "rb").read())
```
