In BIRD, RX has lower priority than TX with the exception of RX from
control socket. The patch replaces heuristic based on socket type with
explicit mark and uses it for both control socket and BGP session waiting
to be established.
This should avoid an issue when during heavy load, outgoing connection
could connect (TX event), send open, but then failed to receive OPEN /
establish in time, not sending notifications between and therefore
got hold timer expired error from the neighbor immediately after it
finally established the connection.
After restart, LSAs locally originated by the previous instance are
received from neighbors. They are installed to LSA db and flushed. If
export of a route triggers origination of a new external LSA before flush
of the received one is complete, the check in ospf_originate_lsa() causes
origination to fail (because en->nf is NULL for the old LSA and non-NULL
for the new LSA). The patch fixes this by updating the en->nf for LSAs
being flushed (as is already done for empty ones). Generally, en->nf
field deserves some better description in the code.
Thanks to Jigar Mehta for analyzing the problem.
When a BGP session was established by an outgoing connection with
Graceful Restart behavior negotiated, a pending incoming connection in
OpenSent state, and another incoming connection was received, then the
outgoing connection (and whole BGP session) was closed, but the old
incoming connection was just overwritten by the new one. That later
caused a crash when the hold timer from the old connection fired.
The patch adds support for channels, structures connecting protocols and
tables and handling most interactions between them. The documentation is
missing yet.
Explicit setting of AF_INET(6|) in IP socket creation. BFD set to listen
on v6, without setting the V6ONLY flag to catch both v4 and v6 traffic.
Squashing and minor changes by Ondrej Santiago Zajicek
New data types net_addr and variants (in lib/net.h) describing
network addresses (prefix/pxlen). Modifications of FIB structures
to handle these data types and changing everything to use these
data types instead of prefix/pxlen pairs where possible.
The commit is WiP, some protocols are not yet updated (BGP, Kernel),
and the code contains some temporary scaffolding.
Comments are welcome.
The new RIP implementation fixes plenty of old bugs and also adds support
for many new features: ECMP support, link state support, BFD support,
configurable split horizon and more. Most options are now per-interface.
The patch adds suport for specifying route attributes together with
static routes, e.g.:
route 10.1.1.0/24 via 10.0.0.1 { krt_advmss = 1200; ospf_metric1 = 100; };
New LSA checksumming code separates generic Fletcher-16 and OSPF-specific
code and avoids back and forth endianity conversions, making it much more
readable and also several times faster.
Prior to this patch, BIRD validates the OSPF LSA checksum by calculating
a new checksum and comparing it with the checksum in the header. Due to
the specifics of the Fletcher checksum used in OSPF, this is not
necessarily correct as the checkbytes in the header may be calculated via
a different means and end up with a different value that is nonetheless
still correct.
The documented means of validating the checksum as specified in RFC 905
B.4 is to calculate c0 and c1 from the unchanged contents of the packet,
which must result in a zero value to be considered valid.
Thanks to Chris Boot for the patch.
Under some circumstances and heavy load, TX could be postponed
until the session fails with hold timer expired.
Thanks to Javor Kliachev for making the bug reproductible.
