The LogRatelimiter class implements a fixed window rate limiter. The
rate limiter allows a fixed amount of bytes to be consumed within a
fixed time window.
[log] Introduce source location type
The SourceLocation type stores the filename and line of a source code
location.
In a later commit we use this type as the key type in an unordered map
and set to keep track of rate limters for each location.
[config] Add -ratelimitlogging config option
The -ratelimitlogging can be used to enable/disable the rate limiting to
disk. Rate limiting is enabled by default.
[log] Add two new categories for unconditional logging
We create two new categories `UNCONDITIONAL_ALWAYS` and
`UNCONDITIONAL_RATE_LIMITED` that are always enabled by default.
LogPrintf now logs using the `UNCONDITIONAL_RATE_LIMITED` category which
will start to apply rate limiting in a later commit.
For some log locations it might be safe to allow more frequent logging
without rate limiting. These locations should use the
`UNCONDITIONAL_ALWAYS` category.
[validation] Exempt UpdateTipLog from rate limiting
UpdateTipLog logs everytime a new tip is activated. This occurs at an
increased frequency during IBD and should therefore be exempt from rate
limiting.
[log] Add rate limiting to LogPrintf
To mitigate disk filling attacks caused by unsafe usages of LogPrintf,
we rate limit LogPrintf by using the fixed window rate limiter
(BCLog::LogRatelimiter) introduced in an earlier commit.
The rate limiting logic is applied per source location instead of
globally. A source location is allowed to log up to 1 MiB per hour.
Source locations that violate the limit will have their logs supressed
for up to one hour.
[test util] Mark ~DebugLogHelper as noexcept(false)
We mark ~DebugLogHelper as noexcept(false) to be able to catch the
exception it throws. This lets us use it in test in combination with
BOOST_CHECK_THROW and BOOST_CHECK_NO_THROW to check that certain log
messages are (not) logged.
[test] Check for expected log rate limiting messages
[test] Test for expected file size changes when rate limiting is enabled
[test] Check that log rate limiting is disabled for exempt source locations
[test] Check that rate limiting can be disabled
There is no change in behavior. This just helps prepare for the
transition from boost::filesystem to std::filesystem by avoiding calls
to methods which will be unsafe after the transaction to std::filesystem
to due lack of a boost::filesystem::path::imbue equivalent and inability
to set a predictable locale.
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Co-authored-by: Kiminuo <kiminuo@protonmail.com>
Co-authored-by: MarcoFalke <falke.marco@gmail.com>
