Maria Matejka [Fri, 29 Sep 2023 14:24:50 +0000 (16:24 +0200)]
Channel: Refeeding by an auxiliary request if needed.
If the protocol supports route refresh on export, we keep the stop-start
method of route refeed. This applies for BGP with ERR or with export
table on, for OSPF, Babel, RIP or Pipe.
For BGP without ERR or for future selective ROA reloads, we're adding an
auxiliary export request, doing the refeed while the main export request
is running, somehow resembling the original method of BIRD 2 refeed.
There is also a refeed request queue to keep track of different refeed
requests.
Maria Matejka [Sun, 24 Sep 2023 21:22:43 +0000 (23:22 +0200)]
Protocols have now assigned startup phases
For now, there are 4 phases: Necessary (device), Connector (kernel, pipe), Generator (static, rpki) and Regular.
Started and reconfigured are from Necessary to Regular, shutdown backwards.
This way, kernel can flush routes before actually being shutdown.
Maria Matejka [Sun, 24 Sep 2023 09:47:24 +0000 (11:47 +0200)]
Table: Fixed feed race condition
The problem happened like this:
1. Single route for the given net in table
2. A feed is started
3. The route is deleted (from another thread)
4. The feed finds an empty net, exports nothing, ignores journal (here is bug)
5. The route is added
6. The export transitions from FEEDING to READY
7. While processing the journal, the route deletion and addition combines into noop.
This way routes mysteriously disappeared in specific cases of link instability.
Problem fixed by explicitly marking the empty-net journal entries as processed in step 4.
Maria Matejka [Thu, 24 Aug 2023 15:00:54 +0000 (17:00 +0200)]
Logging: fixed size logfiles behaving as mmapped ringbuffers
This variant of logging avoids calling write() for every log line,
allowing for waitless logging. This makes heavy logging less heavy
and more useful for race condition debugging.
Maria Matejka [Mon, 21 Aug 2023 16:44:10 +0000 (18:44 +0200)]
Logging now doesn't lock with each message
The original logging routines were locking a common mutex. This led to
massive underperformance and unwanted serialization when heavily logging
due to lock contention. Now the logging is lockless, though still
serializing on write() syscalls to the same filedescriptor.
This change also brings in a persistent logging channel structures and
thus avoids writing into active configuration data structures during
regular run.
Maria Matejka [Mon, 28 Aug 2023 13:36:40 +0000 (15:36 +0200)]
Hostentry application locking
Due to a race condition between rta_apply_hostentry() and rt_update_hostentry(),
happening when a new route is inserted to a table, this commit makes it mandatory
to lock the next hop resolution table while resolving the next hop.
This may be slow, we'll fix it better in some future release
Maria Matejka [Mon, 29 May 2023 17:32:26 +0000 (19:32 +0200)]
BFD: Fixed reconfiguration issues
After converting BFD to the new IO loop system, reconfiguration never
really worked. Sadly, we missed this case in our testing suite so it
passed under the radar for quite a while.
Thanks to Andrei Dinu <andrei.dinu@digitalit.ro> for reporting and
isolating this issue.
Maria Matejka [Sat, 13 May 2023 18:33:35 +0000 (20:33 +0200)]
Fixed abort when running in foreground but stdin is closed
A forgotten else-clause caused BIRD to treat some pseudo-random place in
memory as fd-pair. This was happening only on startup of the first
thread in group and the value there in memory was typically zero ... and
writing to stdin succeeded.
When running BIRD with stdin not present (like systemd does), it died on
this spurious write. Now it seems to work correctly.
Thanks to Daniel Suchy <danny@danysek.cz> for reporting.
Maria Matejka [Mon, 8 May 2023 11:09:02 +0000 (13:09 +0200)]
Properly protecting the route src global index by RCU read lock and atomic operations
There was a bug occuring when one thread sought for a src by its global id
and another one was allocating another src with such an ID that it caused
route src global index reallocation. This brief moment of inconsistency
led to a rare use-after-free of the old global index block.
Maria Matejka [Fri, 5 May 2023 07:39:13 +0000 (09:39 +0200)]
Fixed a bug in hot page global storage
The original algorithm was suffering from an ABA race condition:
A: fp = page_stack
B: completely allocates the same page and writes into it some data
A: unsuspecting, loads (invalid) next = fp->next
B: finishes working with the page and returns it back to page_stack
A: compare-exchange page_stack: fp => next succeeds and writes garbage
to page_stack
Fixed this by using an implicit spinlock in hot page allocator.
Maria Matejka [Sun, 30 Apr 2023 20:17:42 +0000 (22:17 +0200)]
First try of loop balancing
If a thread encounters timeout == 0 for poll, it considers itself
"busy" and with some hysteresis it tries to drop loops for others to
pick and thus better distribute work between threads.
Maria Matejka [Fri, 21 Apr 2023 13:26:06 +0000 (15:26 +0200)]
Resource pools are now bound with domains.
Memory allocation is a fragile part of BIRD and we need checking that
everybody is using the resource pools in an appropriate way. To assure
this, all the resource pools are associated with locking domains and
every resource manipulation is thoroughly checked whether the
appropriate locking domain is locked.
With transitive resource manipulation like resource dumping or mass free
operations, domains are locked and unlocked on the go, thus we require
pool domains to have higher order than their parent to allow for this
transitive operations.
Adding pool locking revealed some cases of insecure memory manipulation
and this commit fixes that as well.
Maria Matejka [Thu, 20 Apr 2023 17:33:00 +0000 (19:33 +0200)]
Linpool: Fix lp_restore()
When lp_save() is called on an empty linpool, then some allocation is
done, then lp_restore() is called, the linpool is restored but the used
chunks are inaccessible. Fix it.
Maria Matejka [Wed, 19 Apr 2023 15:52:52 +0000 (17:52 +0200)]
Typed lists keep an explicit pointer to the list head.
This change adds one pointer worth of memory to every list node.
Keeping this information helps auditing the lists, checking that the
node indeed is outside of list or inside the right one.
The typed lists shouldn't be used anywhere with memory pressure anyway,
thus the one added pointer isn't significant.