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

Thanks to Wei Huang for the bugreport.

Jan Moskyto Matejka authored Nov 03, 2015 and Ondřej Zajíček committed Nov 11, 2015

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.

Thanks to Bernardo Figueiredo and Israel G. Lugo for the bugreport.

Thanks to Pavel Tvrdik for the bugfix

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; };

Thanks to Thomas King for the bugreport.

Thanks to Christian Tacke for the original patch.

Thanks to Peter Hudec for noticing the problem.

Implements draft-ietf-idr-bgp-extended-messages-10, for now
undocumented and with temporary private capability number.

Thanks to Andrew (seti.kr.ua) for the bug report.

Kernel option 'merge paths' allows to merge routes exported to kernel
protocol (currently BGP and static routes) to multipath routes.

In some cases, export filter accessed attributes of a different route.

Related to changes from previous patch.

In some circumstances during reconfiguration, routes propagated by pipes
to other tables may hang there even after the primary routes are removed.

There is already a workaround for this issue in the code which removes
these stale routes by flush process when source protocols are shut down.

This patch is a cleaner fix and allows to simplify the flush process

Linux kernel route metrics (RTA_METRICS netlink route attribute) are
represented and accessible as new route attributes:

krt_mtu, krt_window, krt_rtt, krt_rttvar, krt_sstresh, krt_cwnd, krt_advmss,
krt_reordering, krt_hoplimit, krt_initcwnd, krt_rto_min, krt_initrwnd,
krt_quickack, krt_lock_mtu, krt_lock_window, krt_lock_rtt, krt_lock_rttvar,
krt_lock_sstresh, krt_lock_cwnd, krt_lock_advmss, krt_lock_reordering,
krt_lock_hoplimit, krt_lock_rto_min, krt_feature_ecn, krt_feature_allfrag

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.