When the `Desconnect()` method is called, clients are not disconnected
immediately. Instead, a new coroutine is spawned using the same strand
as the other coroutines. This coroutine calls `async_shutdown` on the
TCP socket, which might be blocking. However, in order not to block
indefintely, the `Timeout` class cancels all operations on the socket
after `10` seconds. Though, the timeout does not trigger the handler
immediately; it creates spawns another coroutine using the same strand
as in the `JsonRpcConnection` class. This can cause unexpected delays if
e.g. `HandleIncomingMessages` gets resumed before the coroutine from the
timeout class. Apart from that, the coroutine for writing messages uses
the same condition, making the two symmetrical.
The previous validation in set_verify_callback() could be bypassed, tricking
Icinga 2 into treating invalid certificates as valid. To fix this, the
validation checks were moved into the IsVerifyOK() function.
This is tracked as CVE-2024-49369, more details will be published at a later time.
Currently, when processing a `CheckResult`, it will first trigger an
`OnNextCheckChanged` event, which is sent to all connected endpoints.
Then, when `Checkable::ProcessCheckResult()` returns, an `OnCheckResult`
event is fired, which is of course also sent to all connected endpoints.
Next, the other endpoints receive the `event::SetNextCheck` cluster
event followed by `event::CheckResult`and invoke
`checkable#SetNextCheck()` and `Checkable#CheckResult()` with the newly
received check. So they also try to recalculate the next check
themselves and invalidate the previously received next check timestamp
from the source endpoint. Since each endpoint randomly initialises its
own scheduling offset, the recalculated next check will always differ by
a split second/millisecond on each of them. As a consequence, two Icinga
DB HA instances will generate two different checksums for the same state
and causes the state histories to be fully resynchronised after a
takeover/Icinga 2 reload.
A day specification like "monday -1" refers to the last Monday of the month.
However, there was an off by one if the first day of the next month is the same
day of the week, i.e. a Monday in this example.
LegacyTimePeriod::FindNthWeekday() picks a day to start the search for the day
in question. When given a negative n to search for the n-th last day, it
wrongly used the first day of the following month as the start and counted it
as if it was within the current month. This resulted in a 1/7 chance that the
result was one week too late.
This is fixed by using the last day of the current month instead.
Especially ApiListener#ReplayLog() enqueued lots of messages into
JsonRpcConnection#{m_IoStrand,m_OutgoingMessagesQueue} (RAM) even if
the connection was shut(ting) down. Now #Disconnect() takes effect ASAP.
This allows the function to be used both with a double timestamp or a pointer
to a tm struct. With this, a similar implementation inside the tests can simply
use our regular function.
So far, the return value of strftime() was simply ignored and the output buffer
passed to the icinga::String constructor. However, there are error conditions
where strftime() returns 0 to signal an error, like if the buffer was too small
for the output. In that case, there's no guarantee on the buffer contents and
reading it can result in undefined behavior. Unfortunately, returning 0 can
also indicate success and strftime() doesn't set errno, so there's no reliable
way to distinguish both situations. Thus, the implementation now returns the
empty string in both cases.
I attempted to use std::put_time() at first as that allows for better error
handling, however, there were problems with the implementation on Windows (see
inline comment), so I put that plan on hold at left strftime() there for the
time being.
