Historically, the inline keyword was a strong suggestion to the compiler
that it should inline the function marked inline. As compilers became
better at optimising, this functionality has receded, and using inline
as a suggestion to inline a function is obsolete. The compiler will
happily ignore it and inline something else entirely if it finds that's
a better optimisation.
Therefore, remove all the occurences of the inline keyword with static
functions inside single compilation unit and leave the decision whether
to inline a function or not entirely on the compiler
NOTE: We keep the usage the inline keyword when the purpose is to change
the linkage behaviour.
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
Clear the key slots for dnssec-sign statistics for keys that are
removed. This way, the number of slots will stabilize to the maximum
key usage in a zone and will not grow every time a key rollover is
triggered.
We have introduced dnssec-sign statistics to the zone statistics. This
introduced an operational issue because when using zone-statistics
full, the memory usage was going through the roof. We fixed this by
by allocating just four key slots per zone. If a zone exceeds the
number of keys for example through a key rollover, the keys will be
rotated out on a FIFO basis.
This works for most cases, and fixes the immediate problem of high
memory usage, but if you sign your zone with many, many keys, or are
sign with a ZSK/KSK double algorithm strategy you may experience weird
statistics. A better strategy is to grow the number of key slots per
zone on key rollover events.
That is what this commit is doing: instead of rotating the four slots
to track sign statistics, named now grows the number of key slots
during a key rollover (or via some other method that introduces new
keys).
Rather than group key ids together, group key id with its
corresponding counters. This should make growing / shrinking easier
than having keyids then counters.
The first attempt to add DNSSEC sign statistics was naive: for each
zone we allocated 64K counters, twice. In reality each zone has at
most four keys, so the new approach only has room for four keys per
zone. If after a rollover more keys have signed the zone, existing
keys are rotated out.
The DNSSEC sign statistics has three counters per key, so twelve
counters per zone. First counter is actually a key id, so it is
clear what key contributed to the metrics. The second counter
tracks the number of generated signatures, and the third tracks
how many of those are refreshes.
This means that in the zone structure we no longer need two separate
references to DNSSEC sign metrics: both the resign and refresh stats
are kept in a single dns_stats structure.
Incrementing dnssecsignstats:
Whenever a dnssecsignstat is incremented, we look up the key id
to see if we already are counting metrics for this key. If so,
we update the corresponding operation counter (resign or
refresh).
If the key is new, store the value in a new counter and increment
corresponding counter.
If all slots are full, we rotate the keys and overwrite the last
slot with the new key.
Dumping dnssecsignstats:
Dumping dnssecsignstats is no longer a simple wrapper around
isc_stats_dump, but uses the same principle. The difference is that
rather than dumping the index (key tag) and counter, we have to look
up the corresponding counter.
This commit simplifies the cachedb rrset statistics in two ways:
- Introduce new rdtypecounter arithmetics, allowing bitwise
operations.
- Remove the special DLV statistic counter.
New rdtypecounter arithmetics
-----------------------------
"The rdtypecounter arithmetics is a brain twister". Replace the
enum counters with some defines. A rdtypecounter is now 8 bits for
RRtypes and 3 bits for flags:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| | | | | | S |NX| RRType |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
If the 8 bits for RRtype are all zero, this is an Other RRtype.
Bit 7 is the NXRRSET (NX) flag and indicates whether this is a
positive (0) or a negative (1) RRset.
Then bit 5 and 6 mostly tell you if this counter is for an active,
stale, or ancient RRtype:
S = 0x00 means Active
S = 0x01 means Stale
S = 0x10 means Ancient
Since a counter cannot be stale and ancient at the same time, we
treat S = 0x11 as a special case to deal with NXDOMAIN counters.
S = 0x11 indicates an NXDOMAIN counter and in this case the RRtype
field signals the expiry of this cached item:
RRType = 0 means Active
RRType = 1 means Stale
RRType = 2 means Ancient
This also removes counting the DLV RRtype separately. Since we have
deprecated the lookaside validation it makes no sense to keep this
special statistic counter.
Having the decrement/increment logic in stats makes the code hard
to follow. Remove it here and adjust the unit test. The caller
will be responsible for maintaining the correct increments and
decrements for statistics counters (in the following commit).
