When a kernel route changed, function krt_learn_scan() noticed that and
replaced the route in internal kernel FIB, but after that, function
krt_learn_prune() failed to propagate the new route to the nest, because
it confused the new route with the (removed) old best route and decided
that the best route did not changed.

Wow, the original code (and the bug) is almost 17 years old.

The events variable is used in the short loop decision. The reasons are
not much clear, keeping this to keep the former behaviour.

The old linked list implementation used some wild typecasts and required
GCC option -fno-strict-aliasing to work properly. This patch fixes that.
However, we still keep the option due to other potential problems.

(Commited by Ondrej Santiago Zajicek)

To avoid byzantine behavior in case of some errors, linked lists are
cleared after rem_node() and resource headers are cleared after rfree().

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.

Thanks to Pavel Tvrdik for noticing it.

It does strange things when even one fd larger than FD_SETSIZE is
passed to select().

This should lift the limit of FD_SETSIZE and allow more than 1024 fd's.
FD_SETSIZE limit doesn't matter now when creating new sockets.

No more need to disable pthread for specific BSD's.

Pointer to current_log_name has to be changed even if the name is the
same, because the old one will be invalid/freed after reconfiguration.

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.

Wanted netlink attributes are defined in a table, specifying
their size and neediness. Removing the long conditions that did the
validation before.

Also parsing IPv4 and IPv6 versions regardless on the IPV6 macro.

Patch from Pavel Tvrdik

If an interface address notification is received during device protocol
shutdown/restart, BIRD crashed.

Thanks to Wei Huang for the bugreport.

Since 2.6.19, the netlink API defines RTA_TABLE routing attribute to
allow 32-bit routing table IDs. Using this attribute to index routing
tables at Linux, instead of 8-bit rtm_table field.

When a table is removed during reconfiguration, a reference was not
cleared in the old configuration, which breaks undo.

Symbol lookup by cf_find_symbol() not only did the lookup but also added
new void symbols allocated from cfg_mem linpool, which gets broken when
lookups are done outside of config parsing, which may lead to crashes
during reconfiguration.

The patch separates lookup-only cf_find_symbol() and config-modifying
cf_get_symbol(), while the later is called only during parsing. Also
new_config and cfg_mem global variables are NULLed outside of parsing.

I should check it after making some trivial changes. The original patch
from Alexander has it right.

If the number of sockets is too much for select(), we should at least
handle it with proper error messages and reject new sockets instead of
breaking the event loop.

Thanks to Alexander V. Chernikov for the patch.

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.