Luiz Amaral authored 1 year ago and Ondřej Zajíček committed 1 year ago

The support for IPv4 routes with IPv6 nexthops was implemented in FreeBSD
13.1, this patch allows to import and export such routes from/to kernel.

Minor change from committer.

Maria Matejka authored 1 year ago and Ondřej Zajíček committed 1 year ago

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.

Trisha Biswas authored 1 year ago and Ondřej Zajíček committed 1 year ago

This option allows to treat bgp_med as regular transitive attribute
on EBGP sessions (without hacks in filters).

Minor changes from committer.

Jakub Ružička authored 1 year ago and Ondřej Zajíček committed 1 year ago

Tests may take longer than 5 s to complete on slow/virtual machines.

Missing translation from BGP attribute ID to eattr ID in bgp_unset_attr()
broke automatic removal of bgp_med during export to EBGP peers.

Thanks to Edward Sun for the bugreport.

The feature of showing all prefixes inside the given one has been added
in v2.0.9 but not well documented. Fixing it by this update.

Text in doc and commit message added by commiter.

Even though the free bind option is primarily meant to alleviate problems
with addresses assigned too late, it's also possible to use BIRD with AnyIP
configuration, assigning whole ranges to the machine. Therefore free bind
allows also to create an outbound connection from specific address even though
such address is not assigned.

Petr Vaněk authored 2 years ago and Ondřej Zajíček committed 2 years ago

and "%M" formats expect "Input/output error" message but musl returns
"I/O error". Proposed change compares the printf output with string
returned from strerror function for EIO constant.

See-also: https://bugs.gentoo.org/836713

Minor change from committer.

When a linpool is used to allocate a one-off big load of memory, it
makes no sense to keep that amount of memory for future use inside the
linpool. Contrary to previous implementations where the memory was
directly free()d, we now use the page allocator which has an internal
cache which keeps the released pages for us and subsequent allocations
simply get these released pages back.

And even if the page cleanup routine kicks in inbetween, the pages get
only madvise()d, not munmap()ed so performance aspects are negligible.

This may fix some memory usage peaks in extreme cases.

The change 371eb490 introduced early free
of old_config. Unfortunately, it did not properly check whether it is not
still in use (blocked by obstacle during reconfiguration). Fix that.

It also means that we still could have a short peak when three configs
are in use (when a new reconfig is requeste while the previous one is
still active).

Toke Høiland-Jørgensen authored 2 years ago and Ondřej Zajíček committed 2 years ago

The babel protocol normally sends all its messages as multicast packets,
but the protocol specification allows most messages to be sent as either
unicast or multicast, and the two can be mixed freely. In particular, the
babeld implementation can be configured to unicast updates to all peers
instead of sending them as unicast.

Daniel discovered that this can cause problems with the packet counter
checks in the MAC extension due to packet reordering. This happens on WiFi
networks where clients have power save enabled (which is quite common in
infrastructure networks): in this case, the access point will buffer all
multicast traffic and only send it out along with its beacons, leading to a
maximum buffering in default Linux-based access point configuration of up
to 200 ms.

This means that a Babel sender that mixes unicast and multicast messages
can have the unicast messages overtake the multicast messages because of
this buffering; when authentication is enabled, this causes the receiver to
discard the multicast message when it does arrive because it now has a
packet counter value less than the unicast message that arrived before it.
Daniel observed that this happens frequently enough that Babel ceases to
work entirely when runner over a WiFi network.

The issue has been described in draft-ietf-babel-mac-relaxed, which is
currently pending RFC publication. That also describes two mitigation
mechanisms: Keeping separate PC counters for unicast and multicast, and
using a reorder window for PC values. This patch implements the former as
that is the simplest, and resolves the particular issue seen on WiFi.

Thanks to Daniel Gröber for the bugreport.

Minor changes from committer.

andi authored 2 years ago and Ondřej Zajíček committed 2 years ago

The patch implements an IPv4 via IPv6 extension (RFC 9229) to the Babel
routing protocol (RFC 8966) that allows annoncing routes to an IPv4
prefix with an IPv6 next hop, which makes it possible for IPv4 traffic
to flow through interfaces that have not been assigned an IPv4 address.

The implementation is compatible with the current Babeld version.

Thanks to Toke Høiland-Jørgensen for early review on this work.

Minor changes from committer.

There are many compatibility issues with echo -e, scratch that.

There ware missing dependencies for proto-build.c generation, which
sometimes lead to failed builds, and ignores changes in the set of
built protocols. Fix that, and also improve formatting of proto-build.c

Toke Høiland-Jørgensen authored 2 years ago and Ondřej Zajíček committed 2 years ago

When creating a new babel_source object we initialise the seqno to 0. The
caller will update the source object with the right metric and seqno value,
for both newly created and old source objects. However if we initialise the
source object seqno to 0 that may actually turn out to be a valid (higher)
seqno than the one in the routing table, because of seqno wrapping. In this
case the source metric will not be set properly, which breaks feasibility
tracking for subsequent updates.

To fix this, add a new initial_seqno argument to babel_get_source() which
is used when allocating a new object, and set that to the seqno value of
the update we're sending.

Thanks to Juliusz Chroboczek for the bugreport.

Add a comment and (unnecessary) check to make correctness obvious.

Toke Høiland-Jørgensen authored 2 years ago and Ondřej Zajíček committed 2 years ago

Juliusz noticed there were a couple of places we were doing straight
inequality comparisons of seqnos in Babel. This is wrong because seqnos can
wrap: so we need to use the modulo-64k comparison function for these cases
as well.

Introduce a strict-inequality version of the modulo-comparison for this
purpose.

For active sessions, ignore received packets with zero local id and
mismatched remote id. That forces a session timeout instead of an
immediate session restart. It makes BFD sessions more resilient to
packet spoofing.

Thanks to André Grüneberg for the suggestion.

Protocols receive if_notify() announcements that are filtered according
to their VRF setting, but during reconfiguration, they access iface_list
directly and forgot to check VRF setting here, which leads to all
interfaces be addedd.

Fix this issue for Babel, OSPF, RAdv and RIP protocols.

Thanks to Marcel Menzel for the bugreport.

 - Fix THP disable on old systems
 - Failed syscalls should use die() instead of bug()
 - Our printf uses %ld for s64 instead of long

When BIRD has no free memory mapped, it allocates several pages in
advance just to be sure that there is some memory available if needed.
This hysteresis tactics works quite well to reduce memory ping-ping with
kernel.

Yet it had a subtle bug: this pre-allocation didn't take a memory
coldlist into account, therefore requesting new pages from kernel even
in cases when there were other pages available. This led to slow memory
bloating.

To demonstrate this behavior fast enough to be seen well, you may:
  * temporarily set the values in sysdep/unix/alloc.c as follows to
    exacerbate the issue:
      #define KEEP_PAGES_MAIN_MAX    4096
      #define KEEP_PAGES_MAIN_MIN    1000
      #define CLEANUP_PAGES_BULK     4096
  * create a config file with several millions of static routes
  * periodically disable all static protocols and then reload config
  * log memory consumption

This should give you a steady growth rate of about 16kB per cycle. If
you don't set the values this high, the issue happens much more slowly,
yet after 14 days of running, you are going to see an OOM kill.

After this fix, pre-allocation uses the memory coldlist to get some hot
pages and the same test as described here gets you a perfectly stable
constant memory consumption (after some initial wobbling).

Thanks to NIX-CZ for reporting and helping to investigate this issue.
Thanks to Santiago for finding the cause in the code.

rcarpa authored 2 years ago and Ondřej Zajíček committed 2 years ago

Add static route attribute to set onlink flag for route next hop. Can be
used to build a dynamically routed IP-in-IP overlay network. Usage:

     ifname = "tunl0";
     onlink = true;
     gw = bgp_next_hop;

The usage pattern implemented in allocator seems to be incompatible with
transparent huge pages, as memory released using madvise(MADV_DONTNEED)
with regular page size and alignment does not seem to trigger demotion
of huge pages back to regular pages, even when significant number of
pages is released. Even if demotion is triggered when system memory
is low, it still breaks memory accounting.

Add support for kernel route metric/priority, exported as krt_metric
attribute, like in Linux. This should also fix issues with overwriting
or removing system routes.

Mike Crute authored 2 years ago and Ondřej Zajíček committed 2 years ago

Log message before aborting due to watchdog timeout. We have to use
async-safe write to debug log, as it is done in signal handler.

Minor changes from committer.

Most branching instructions (FI_CONDITION, FI_AND, FI_OR) linearize its
branches in a recursive way, while FI_SWITCH branches are linearized
from parser even before the switch instruction is allocated.

Change linearization of FI_SWITCH branches to make it similar to other
branching instructions. This also fixes an issue with constant
switch evaluation, where linearized branch is mistaken for
non-linearized during switch construction.

Thanks to Jiten Kumar Pathy for the bugreport.

Some of these new BGP role keywords use generic names that collides with
user-defined symbols. Allow them to be redefined. Also remove duplicit
keyword definition for 'prefer'.