Cryptographic authentication in OSPF is defective by
design - there might be several packets independently
sent to the network (for example HELLO, LSUPD and LSACK)
where they might be reordered and that causes crypt.
sequence number error.
That can be workarounded by not incresing sequence number
too often. Now we update it only when last packet was sent
before at least one second. This can constitute a risk of
replay attacks, but RFC supposes something similar (like time
in seconds used as CSN).
If a DBDES packet from a master to a slave is lost, then the old code
does not retransmit it and instead send a next one with the same
sequence number. That leads to silent desynchronization of LSA
databases.
AS4 optional attribute errors were handled by session
drop (according to BGP RFC). This patch implements
error handling according to new BGP AS4 draft (*)
- ignoring invalid AS4 optional attributes.
(*) http://www.ietf.org/internet-drafts/draft-chen-rfc4893bis-02.txt
This patch extends the length for attributes from 1024 to 2048
(because both AS_PATH and AS4_PATH attributes take 2+4 B per AS).
If there is not enough space for attributes, Bird skips that
route group. Old behavior (skipping remaining attributes)
leads to skipping required attributes and session drop.
When OSPF neighbor state drops down to EXSTART,
clear LSA request and retransmit lists, as specified
by RFC. I hope that this will prevent oscillations
between EXSTART and LOADING states, which sometimes
happened.
It also contains related fix from Yury Shevchuk that
properly resets DB summary list iterator.
When capability related error is received, next connect will be
without capabilities. Also cease error subcodes descriptions
(according to [RFC4486]) are added.
BGP keeps its copy of configuration ptr and didn't update it during
reconfiguration. But old configuration is freed during reconfiguration.
That leads to unnecessary reset of BGP connection during reconfiguration
(old conf is corrupted and therefore different) and possibly other strange
behavior.
Fixes two race conditions causing crash of Bird, several unhandled
cases during BGP initialization, and some other bugs. Also changes
handling of startup delay to be more useful and implement
reporting of last error in 'show protocols' command.
values for MD5 password ID changed during reconfigure, Second
bug is that BIRD chooses password in first-fit manner, but RFC
says that it should use the one with the latest generate-from.
It also modifies the syntax for multiple passwords.
Now it is possible to just add more 'password' statements
to the interface section and it is not needed to use
'passwords' section. Old syntax can be used too.
RFC says that only connections in OpenConfirm and Established state
should participate in connection collision detection.
The current implementation leads to race condition when both sides
are trying to connect at the almost same time, then both sides
receive OPEN message by different connections at the almost same
time and close the other connection. Both connections are
closed and the both sides end in start/idle or start/active
state.
Two new CLI commands for OSPF giving nice informative (and still machine
parsable) representation of OSPF network graph (based on datas from the
LSA database).
The first command (show ospf topology) shows routers, networks and stub
networks, The second command (show ospf state) shows also external
routes and area-external networks and routers propagated by given area
boundary router.
The code generating LSAs for PTP OSPF links is buggy. The old behavior
is that it generates PTP link if there is a full/ptp neighbor and stub
link if there isn't. According to RFC 2328, the correct behavior is to
generate stub link in both cases (in the first case together with PTP
link).
And because of buggy detection of unnumbered networks, for numbered
networks the code creates stub links with 0.0.0.0/32.
- Old MED handling was completely different from behavior
specified in RFCs - for example they havn't been propagated
to neighboring areas.
- Update tie-breaking according to RFC 4271.
- Change default value for 'default bgp_med' configuration
option according to RFC 4271.
