bird/TODO

Core
~~~~
* protocols: implement dumping of protocol-dependent rte attributes

- io.c: refuse old-style multicasts for unnumbered interfaces?

- prefer loopback addresses as router IDs (dummy interface?)

- config: executable config files

- do we really need preconfig?

- counters (according to SNMP MIB?)
- better memory allocators
- default preferences of protocols: prefer BGP over OSPF/RIP external routes?
- secondary addresses -> subinterfaces or ignore

- static: check validity of route destination?

- device: configuration of interface patterns

- adding of route: check whether all bits not covered by masklen are zero

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

- iface: when seen an invalid broadcast, fix it up or at least report
- iface: we always need ifindex at least for PtP links (OSPF)
- iface: interface filters should support filtering by IP address as well
- iface: SIOCGIFINDEX exists on glibc systems, but it doesn't work on 2.0.x kernels!

- socket: Use IP_RECVERR for BGP TCP sockets?

- OSPF: refuse running on non-multicast devices

- lib: use better checksum function

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?

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
- 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?)


RIP
~~~
	- RIP: export-only and import-only mode?
	- drop RIPv1 (Historic protocol)?
	- Route Tag
	- limit routing table xfer (frequency, only to neighbors)
	- multicast on/off (per interface)

OSPF
~~~~
	- importing of device routes for networks where we don't run OSPF
	- check incoming packets using neighbor cache
	- stub area: either no external routes or only default route
	- RFC2328 appendix E: Use a better algorithm
	- automatic generation of external route tags (RFC1403)
	- RFC1587 NSSA areas
	- RFC2370 opaque LSA's
	- RFC1793 Demand Circuit Support ??
	- respect interface MTU and try not to create larger packets unless unavoidable


BGP
~~~
	- in, local, out RIB
	- maxsize=4096
	- detection of loops
	- aggregation, ATOMIC_AGGREGATE
	- communities
	- confederations
	- 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`
			`~~~~`
Added new protocol hook for dumping of protocol-dependent route attributes. Please implement in all protocols. 1999-04-03 21:01:58 +08:00			`* protocols: implement dumping of protocol-dependent rte attributes`

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			`- io.c: refuse old-style multicasts for unnumbered interfaces?`

Removed TOS support. This simplifies many things a lot. 1999-04-13 02:01:07 +08:00			`- prefer loopback addresses as router IDs (dummy interface?)`

config->router_id works again. 1999-02-14 02:42:00 +08:00			`- config: executable config files`
We parse /proc/net/route and flag RT entries according to it. More to come today in the morning... 1998-10-19 06:25:56 +08:00
Moved to a much more systematic way of configuring kernel protocols. o Nothing is configured automatically. You _need_ to specify the kernel syncer in config file in order to get it started. o Syncing has been split to route syncer (protocol "Kernel") and interface syncer (protocol "Device"), device routes are generated by protocol "Direct" (now can exist in multiple instances, so that it will be possible to feed different device routes to different routing tables once multiple tables get supported). See doc/bird.conf.example for a living example of these shiny features. 1999-03-27 05:44:38 +08:00			`- do we really need preconfig?`

First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00			`- counters (according to SNMP MIB?)`
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- better memory allocators`
			`- default preferences of protocols: prefer BGP over OSPF/RIP external routes?`
Pruned the TODO list. 1999-03-02 01:51:29 +08:00			`- secondary addresses -> subinterfaces or ignore`
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?`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00
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			`- device: configuration of interface patterns`

`wc -l TODO` decreased. 1998-11-29 22:51:47 +08:00			`- adding of route: check whether all bits not covered by masklen are zero`
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?`

Netlink module supports interface scan on startup. Working on more. 1999-03-03 02:37:02 +08:00			`- iface: when seen an invalid broadcast, fix it up or at least report`
			`- iface: we always need ifindex at least for PtP links (OSPF)`
Removed TOS support. This simplifies many things a lot. 1999-04-13 02:01:07 +08:00			`- iface: interface filters should support filtering by IP address as well`
Netlink support for secondary interface addresses. 1999-05-07 21:46:16 +08:00			`- iface: SIOCGIFINDEX exists on glibc systems, but it doesn't work on 2.0.x kernels!`
Netlink module supports interface scan on startup. Working on more. 1999-03-03 02:37:02 +08:00
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?`

Added --with-sysinclude to allow explicitly setting where kernel includes reside, so that you can easily switch between 2.0 and 2.2 ones. Check existence of <linux/rtnetlink.h> for linux-22 configs to make sure we're using the correct set of includes. 1999-05-21 22:09:06 +08:00			`- OSPF: refuse running on non-multicast devices`

Added ip_skip_header() and modified OSPF to use it. 1999-05-15 02:03:09 +08:00			`- lib: use better checksum function`

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?`
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]`
Cleaned up TODO file. That's all for today, midnight gets closer. 1999-02-14 06:13:04 +08:00			`- aggregate engine: standard route aggregation and summarization`
			`- 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?)`
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`
			`~~~`
			`- RIP: export-only and import-only mode?`
			`- drop RIPv1 (Historic protocol)?`
			`- Route Tag`
			`- limit routing table xfer (frequency, only to neighbors)`
`wc -l TODO` decreased. 1998-11-29 22:51:47 +08:00			`- multicast on/off (per interface)`
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`
			`~~~~`
			`- 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`
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- stub area: either no external routes or only default route`
Pruned the TODO list. 1999-03-02 01:51:29 +08:00			`- 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`
			`- RFC1793 Demand Circuit Support ??`
			`- 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`
			`~~~`
			`- in, local, out RIB`
			`- maxsize=4096`
BIRD library: The story continues. Complete resource manages and IP address handling. 1998-05-04 00:43:39 +08:00			`- detection of loops`
First look at data structures. More to come tomorrow... 1998-04-22 20:58:34 +08:00			`- aggregation, ATOMIC_AGGREGATE`
			`- communities`
			`- confederations`
			`- 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)`