Don't log malformed packets in default verbosity

[nanopack]

Don't log malformed packets in default verbosity

[ashutoshrishi]

Hey I think this is affecting us too, even after re-provisioning a fresh aws instance. The /var/log/syslog is flooded with requests. Every endpoint request is logged there. The logs are taking up 85% disk space, and we have to clear it every half day.

Dec 04 09:12:43 ip-172-31-42-162 redd[2968]: len: 1500, ip_header: 5, ip_header->len: 1500, udp_header: 1530
Dec 04 09:12:43 ip-172-31-42-162 redd[2968]: 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
Dec 04 09:12:43 ip-172-31-42-162 redd[2968]: 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
Dec 04 09:12:43 ip-172-31-42-162 redd[2968]: E
Dec 04 09:12:43 ip-172-31-42-162 redd[2968]: [4B blob data]

^ this is logged for every reqeuest

[notxarb]

https://github.com/nanopack/redd/blob/master/src/route.c#L70-L80
Those are the lines that cause the logging.

[notxarb]

It might be caused by something trying to send a packet that is bigger than the MTU. It looks like the UDP packet thinks it has 1530 bytes, the IP frame thinks it's only 1500, so it looks like it probably got truncated somewhere.

redd would log and drop the packet.
I agree that it shouldn't print every bad packet by default. It may not even need to log that there was a bad packet normally. I think the kernel likes to drop bad packets without logging.

[notxarb]

Being printf rather than going to the logger, I probably had it in there for my local testing, and it shouldn't have been pushed to the final version.