bird/TODO

Core
~~~~
- IPv6: router advertisements
- IPv6: test it!
- IPv6: hashing functions etc.

- krt-iface: check whether the interface alias hack works
- krt-iface and netlink: unnumberedness of tunnels

- better memory allocators
- real attribute cache
- real neighbor cache

- preferences of protocols

- static: check validity of route destination?
- static: allow specifying a per-route filter program for setting route attributes?

- rte_update: check whether all bits not covered by masklen are zero
- rte_update: debug mode

- netlink: import Linux route attributes to our rta's, so that they can be filtered?

- socket: Use IP_RECVERR for BGP TCP sockets?

- config: executable config files
- config: when parsing prefix, check zero bits
- config: useless rules when protocols disabled
- config: better datetime format

- krt: rescan interfaces when route addition fails?
- krt: does PERSIST mode have any sense if kernel syncer is shut down as last?
- krt: check behaviour wrt. reconfiguration of routing tables

- tagging of external routes?

- io: use poll if available

Commands
~~~~~~~~
show	<name>			# show everything you know about symbol <name>
	rip ??? [<name>]
	ospf ??? [<name>]
	static ??? [<name>]
	symbols
- showing of routing table as seen by given protocol
- showing of deleted routing tables and filters

Roadmap
~~~~~~~
- Allocators and data structures
- Client
- Remaining bits of IPv6 support (radvd)
- RIPv6
- BGP?
- Logging and debugging messages

Client
~~~~~~
- write it!

Documentation
~~~~~~~~~~~~~
- write doctool
- write documentation :|

Cleanup
~~~~~~~
- right usage of DBG vs. debug
- cleanup debugging calls
- logging and tracing; use appropriate log levels
- check incoming packets and log errors!!
- check log calls for trailing newlines
- check if all protocols set proper packet priorities and TTL's.
- replace all NUM, IPA and expr tokens by constant filter expressions
- try compiling with -Wunused
- does everybody test return value of sk_open?
- add references to RFC's we did follow
- protocols: implement CLI hooks
- protocols: implement reconfigure hook
- protocols: use locking

Various ideas
~~~~~~~~~~~~~
- real multipath (doesn't seem to be simple at all :()
- fake multipath (even less simple)
- route recalculation timing and flap dampening [see RFC2439 for algorithms]
- aggregate engine: standard route aggregation and summarization [RFC2519]
- aggregate engine: injection of manually configured pseudo-static routes
- generate default route if any working BGP connection exists (aggregate engine again?)
- generate default route to IGP's (aggregate engine yet another time?)
- look at RFC 2386 (QoS-based routing)


RIP
~~~

OSPF
~~~~
	- refuse running on non-multicast devices
	- importing of device routes for networks where we don't run OSPF
	- check incoming packets using neighbor cache
	- RFC2328 appendix E: Use a better algorithm
	- automatic generation of external route tags (RFC1403)
	- RFC1587 NSSA areas
	- RFC2370 opaque LSA's
	- respect interface MTU and try not to create larger packets unless unavoidable

BGP
~~~
	- aggregation, ATOMIC_AGGREGATE
	- communities
	- attributes must be sorted!
	- re-export of NEXT_HOP attribute
	- BGP session over currently down interface
	- LOCAL_PREF attribute
	- error notification received -> log error
	- set TTL to 1 (configurable?)
	- consulting IGP for next-hop information? (what if it changes?)
	- inter-advertisement delay???!
	- normalize (sort) incoming AS-SET's
	- maximum length of AS paths
	- expected neighbor AS
	- hold time
	- idle timer after error: initial value, exponential growth, maximum value
	- import of IGP routes (use external route tags from OSPF)
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00			`Core`
			`~~~~`
Minor cleanups. 1999-12-16 21:51:43 +08:00			`- IPv6: router advertisements`
			`- IPv6: test it!`
			`- IPv6: hashing functions etc.`

			`- krt-iface: check whether the interface alias hack works`
			`- krt-iface and netlink: unnumberedness of tunnels`
Recognize site scope for IPv4 addresses (prefixes reserved for private networks). Removed old #ifndef logic which was used to avoid IPv4/IPv6 clashes before conditionals in Modules lists were introduced. 1999-04-28 00:03:17 +08:00
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- better memory allocators`
Pruned the TODO list. 1999-08-04 03:35:01 +08:00			`- real attribute cache`
			`- real neighbor cache`

Minor cleanups. 1999-12-16 21:51:43 +08:00			`- preferences of protocols`
Hopefully finished kernel syncer (krt) rewrite: o Interface syncing is now a part of krt and it can have configurable parameters. Actually, the only one is scan rate now :) o Kernel routing table syncing is now synchronized with interface syncing (we need the most recent version of the interface list to prevent lots of routes to non-existent destinations from appearing). Instead of its own timer, we just check if it's route scan time after each iface list scan. o Syncing of device routes implemented. o CONFIG_AUTO_ROUTES should control syncing of automatic device routes. o Rewrote krt_remove_route() to really remove routes :) o Better diagnostics. o Fixed a couple of bugs. 1998-12-09 02:37:58 +08:00
All static routes except for device ones should work and appear/disappear when their destination comes on/off link. Deserves better testing :) See example in bird.conf. 1998-12-07 07:13:31 +08:00			`- static: check validity of route destination?`
Basic support for IPv6. The system-dependent part doesn't work yet, but the core routines are there and seem to be working. o lib/ipv6.[ch] written o Lexical analyser recognizes IPv6 addresses and when in IPv6 mode, treats pure IPv4 addresses as router IDs. o Router ID must be configured manually on IPv6 systems. o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts. o Fixed few places where ipa_(hton\|ntoh) was called as a function returning converted address. 1999-08-04 03:36:06 +08:00			`- static: allow specifying a per-route filter program for setting route attributes?`
Finer grained logging levels: #define L_DEBUG "\001" /* Debugging messages / #define L_INFO "\002" / Informational messages / #define L_WARN "\003" / Warnings / #define L_ERR "\004" / Errors / #define L_AUTH "\005" / Authorization failed etc. / #define L_FATAL "\006" / Fatal errors / #define L_TRACE "\002" / Protocol tracing / #define L_INFO "\003" / Informational messages / #define L_REMOTE "\004" / Remote protocol errors / #define L_WARN "\004" / Local warnings / #define L_ERR "\005" / Local errors / #define L_AUTH "\006" / Authorization failed etc. / #define L_FATAL "\007" / Fatal errors / #define L_BUG "\010" / BIRD bugs */ Introduced bug() which is like die(), but with level L_BUG. Protocols should _never_ call die() as it should be used only during initialization and on irrecoverable catastrophic events like out of memory. Also introduced ASSERT() which behaves like normal assert(), but it calls bug() when assertion fails. When !defined(DEBUGGING), it gets ignored. 1998-12-20 22:24:35 +08:00
Pruned the TODO list. 1999-08-04 03:35:01 +08:00			`- rte_update: check whether all bits not covered by masklen are zero`
			`- rte_update: debug mode`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00
Added skeletal version of Linux netlink interface. It doesn't work yet, but the framework is there and I'll try finish it soon. 1999-03-02 04:17:46 +08:00			`- netlink: import Linux route attributes to our rta's, so that they can be filtered?`

I rewrote the interface handling code, so that it supports multiple addresses per interface (needed for example for IPv6 support). Visible changes: o struct iface now contains a list of all interface addresses (represented by struct ifa), iface->addr points to the primary address (if any). o Interface has IF_UP set iff it's up and it has a primary address. o IF_UP is now independent on IF_IGNORED (i.e., you need to test IF_IGNORED in the protocols; I've added this, but please check). o The if_notify_change hook has been simplified (only one interface pointer etc.). o Introduced a ifa_notify_change hook. (For now, only the Direct protocol does use it -- it's wise to just listen to device routes in all other protocols.) o Removed IF_CHANGE_FLAGS notifier flag (it was meaningless anyway). o Updated all the code except netlink (I'll look at it tomorrow) to match the new semantics (please look at your code to ensure I did it right). Things to fix: o Netlink. o Make krt-iface interpret "eth0:1"-type aliases as secondary addresses. 1999-05-07 05:38:11 +08:00			`- socket: Use IP_RECVERR for BGP TCP sockets?`

Pruned the TODO list. 1999-08-04 03:35:01 +08:00			`- config: executable config files`
Kernel route syncer supports multiple tables. The changes are just too extensive for lazy me to list them there, but see the comment at the top of sysdep/unix/krt.c. The code got a bit more ifdeffy than I'd like, though. Also fixed a bunch of FIXME's and added a couple of others. :) 1999-08-04 03:33:22 +08:00			`- config: when parsing prefix, check zero bits`
Basic support for IPv6. The system-dependent part doesn't work yet, but the core routines are there and seem to be working. o lib/ipv6.[ch] written o Lexical analyser recognizes IPv6 addresses and when in IPv6 mode, treats pure IPv4 addresses as router IDs. o Router ID must be configured manually on IPv6 systems. o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts. o Fixed few places where ipa_(hton\|ntoh) was called as a function returning converted address. 1999-08-04 03:36:06 +08:00			`- config: useless rules when protocols disabled`
Minor cleanups. 1999-12-16 21:51:43 +08:00			`- config: better datetime format`
Kernel route syncer supports multiple tables. The changes are just too extensive for lazy me to list them there, but see the comment at the top of sysdep/unix/krt.c. The code got a bit more ifdeffy than I'd like, though. Also fixed a bunch of FIXME's and added a couple of others. :) 1999-08-04 03:33:22 +08:00
			`- krt: rescan interfaces when route addition fails?`
Pruned the TODO list. 1999-08-04 03:35:01 +08:00			`- krt: does PERSIST mode have any sense if kernel syncer is shut down as last?`
First attempt on dynamic reconfiguration. There are still lots of bugs and problems to solve, but the hardest part works. 2000-01-17 00:44:50 +08:00			`- krt: check behaviour wrt. reconfiguration of routing tables`
Pruned the TODO list. 1999-08-04 03:35:01 +08:00
			`- tagging of external routes?`

Minor cleanups. 1999-12-16 21:51:43 +08:00			`- io: use poll if available`

Added skeleton of command tree. Please inspect. 1999-11-17 22:58:21 +08:00			`Commands`
			`~~~~~~~~`
Remember protocol instance in proto_config and use that for `show protocols <name>'. 1999-11-30 22:04:09 +08:00			`show <name> # show everything you know about symbol <name>`
Added skeleton of command tree. Please inspect. 1999-11-17 22:58:21 +08:00			`rip ??? [<name>]`
			`ospf ??? [<name>]`
			`static ??? [<name>]`
Added DEBUG commands. Removed CLI tests, real commands now serve as much better examples. 1999-12-05 07:17:29 +08:00			`symbols`
Minor cleanups. 1999-12-16 21:51:43 +08:00			`- showing of routing table as seen by given protocol`
First attempt on dynamic reconfiguration. There are still lots of bugs and problems to solve, but the hardest part works. 2000-01-17 00:44:50 +08:00			`- showing of deleted routing tables and filters`

			`Roadmap`
			`~~~~~~~`
			`- Allocators and data structures`
			`- Client`
			`- Remaining bits of IPv6 support (radvd)`
			`- RIPv6`
			`- BGP?`
			`- Logging and debugging messages`
Minor cleanups. 1999-12-16 21:51:43 +08:00
			`Client`
			`~~~~~~`
			`- write it!`

			`Documentation`
			`~~~~~~~~~~~~~`
			`- write doctool`
			`- write documentation :\|`
Added skeleton of command tree. Please inspect. 1999-11-17 22:58:21 +08:00
Cleaned up TODO file. That's all for today, midnight gets closer. 1999-02-14 06:13:04 +08:00			`Cleanup`
			`~~~~~~~`
			`- right usage of DBG vs. debug`
			`- cleanup debugging calls`
			`- logging and tracing; use appropriate log levels`
			`- check incoming packets and log errors!!`
			`- check log calls for trailing newlines`
			`- check if all protocols set proper packet priorities and TTL's.`
Updated the TODO list. 1999-03-30 04:46:00 +08:00			`- replace all NUM, IPA and expr tokens by constant filter expressions`
Implemented netlink protocol parsing functions. More to come tomorrow. 1999-03-02 06:31:27 +08:00			`- try compiling with -Wunused`
Fixed a couple of bugs in handling of multicast sockets. See comments in lib/socket.h for a detailed guide on how to use them. 1999-04-12 22:57:46 +08:00			`- does everybody test return value of sk_open?`
Basic support for IPv6. The system-dependent part doesn't work yet, but the core routines are there and seem to be working. o lib/ipv6.[ch] written o Lexical analyser recognizes IPv6 addresses and when in IPv6 mode, treats pure IPv4 addresses as router IDs. o Router ID must be configured manually on IPv6 systems. o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts. o Fixed few places where ipa_(hton\|ntoh) was called as a function returning converted address. 1999-08-04 03:36:06 +08:00			`- add references to RFC's we did follow`
Added DEBUG commands. Removed CLI tests, real commands now serve as much better examples. 1999-12-05 07:17:29 +08:00			`- protocols: implement CLI hooks`
Separated `official protocol names' used in status dumps from name templates used for automatic generation of instance names. protocol->name is the official name protocol->template is the name template (usually "name%d"), should be all lowercase. Updated all protocols to define the templates, checked that their configuration grammar includes proto_name which generates the name and interns it in the symbol table. 2000-01-17 19:52:50 +08:00			`- protocols: implement reconfigure hook`
TODO entries and FIXME's. 1999-12-16 20:18:33 +08:00			`- protocols: use locking`
Cleaned up TODO file. That's all for today, midnight gets closer. 1999-02-14 06:13:04 +08:00
			`Various ideas`
			`~~~~~~~~~~~~~`
			`- real multipath (doesn't seem to be simple at all :()`
			`- fake multipath (even less simple)`
Pruned the TODO list. 1999-03-02 01:51:29 +08:00			`- route recalculation timing and flap dampening [see RFC2439 for algorithms]`
Basic support for IPv6. The system-dependent part doesn't work yet, but the core routines are there and seem to be working. o lib/ipv6.[ch] written o Lexical analyser recognizes IPv6 addresses and when in IPv6 mode, treats pure IPv4 addresses as router IDs. o Router ID must be configured manually on IPv6 systems. o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts. o Fixed few places where ipa_(hton\|ntoh) was called as a function returning converted address. 1999-08-04 03:36:06 +08:00			`- aggregate engine: standard route aggregation and summarization [RFC2519]`
Cleaned up TODO file. That's all for today, midnight gets closer. 1999-02-14 06:13:04 +08:00			`- aggregate engine: injection of manually configured pseudo-static routes`
			`- generate default route if any working BGP connection exists (aggregate engine again?)`
			`- generate default route to IGP's (aggregate engine yet another time?)`
Basic support for IPv6. The system-dependent part doesn't work yet, but the core routines are there and seem to be working. o lib/ipv6.[ch] written o Lexical analyser recognizes IPv6 addresses and when in IPv6 mode, treats pure IPv4 addresses as router IDs. o Router ID must be configured manually on IPv6 systems. o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts. o Fixed few places where ipa_(hton\|ntoh) was called as a function returning converted address. 1999-08-04 03:36:06 +08:00			`- look at RFC 2386 (QoS-based routing)`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00

BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`RIP`
			`~~~`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`OSPF`
			`~~~~`
Tried to clean up multicast handling. Now we don't try to guess multicast abilities depending on definedness of symbols and use hard-wired system-dependent configuration defines instead. Please test whereever you can. 1999-12-16 21:06:13 +08:00			`- refuse running on non-multicast devices`
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- importing of device routes for networks where we don't run OSPF`
Pruned the TODO list. 1999-03-02 01:51:29 +08:00			`- check incoming packets using neighbor cache`
			`- RFC2328 appendix E: Use a better algorithm`
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- automatic generation of external route tags (RFC1403)`
Pruned the TODO list. 1999-03-02 01:51:29 +08:00			`- RFC1587 NSSA areas`
			`- RFC2370 opaque LSA's`
			`- respect interface MTU and try not to create larger packets unless unavoidable`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00
			`BGP`
			`~~~`
			`- aggregation, ATOMIC_AGGREGATE`
			`- communities`
			`- attributes must be sorted!`
			`- re-export of NEXT_HOP attribute`
			`- BGP session over currently down interface`
			`- LOCAL_PREF attribute`
			`- error notification received -> log error`
			`- set TTL to 1 (configurable?)`
			`- consulting IGP for next-hop information? (what if it changes?)`
			`- inter-advertisement delay???!`
			`- normalize (sort) incoming AS-SET's`
			`- maximum length of AS paths`
			`- expected neighbor AS`
			`- hold time`
			`- idle timer after error: initial value, exponential growth, maximum value`
			`- import of IGP routes (use external route tags from OSPF)`