upgrade to babeld 1.8.1 (or later version)

[jhpoelen]

Currently, we are using a custom fork of babeld. I believe that the reason for forking was to add the ability to add / remove interfaces at runtime (e.g., options -a and -x), without having to restart babeld. Another reason was to have the ability to dump babeld state. Many modifications were made and the functionality was not merged back into mainline babeld.

In context of a segmentation fault bug (#31), @jech, the author of babeld suggested to upgrade to a recent version main-line (see #31 (comment)). Apparently, babeld version after 1.7.0 have the ability to add/remove interfaces without having to restart babeld. Also, it appears that some debugging ("dump") command can be used to extract state info from babeld process. Understandable, the author is willing to help debug the issue only after we start using a mainline version of babeld.

Suggest to switch to version 1.8.1 of babeld and deprecate our own babeld fork. Note that our current fork was last synced on 31 March 2015, just before the release of babeld 1.6.0 .

[jech]

In context of a segmentation fault bug (#31), @jech, the author of babeld suggested to upgrade to a recent version main-line (see #31 (comment)).

Please.

the author is willing to help debug the issue only after we start using a mainline version of babeld.

I'd be quite willing to help in either case, but I'd be grateful if you could upgrade first.

[paidforby]

+1 👍

[paidforby]

Since there are a lot of interdependent changes that need to happen to do this upgrade, I suggest we coordinate some the work.

• sudowrt-firmware needs to be re-built with main fork of babeld, https://github.com/sudomesh/sudowrt-firmware/blob/master/openwrt_config/packages#L45
• Any sudomesh/babeld dependent configs/scripts in firmware need to be removed or refactored, potential problem files, https://github.com/sudomesh/sudowrt-firmware/blob/zeroconf/files/opt/notdhcpserver/hook.sh#L48 and https://github.com/sudomesh/sudowrt-firmware/blob/zeroconf/files/opt/mesh/templates/etc/init.d/meshrouting
  Note: I mostly interested in this in the context of zeroconf, of course, necessary changes will also need to be made to makenode
• exitnode needs to clone main babeld (or just apt-get it?), https://github.com/sudomesh/exitnode/blob/master/create_exitnode.sh#L77
• sudomesh/babeld dependent scripts in exitnode need to be refactored https://github.com/sudomesh/exitnode/blob/master/create_exitnode.sh#L113

I guess the first step would be to start a new build of the firmware with main babeld. Then spin up a test exit node also with main babeld. Finally, get them to babel by testing changes manually.

[jhpoelen]

Nice breakdown. I'd argue that the exit node work can be done independently of the firmware work. Here, I am assuming that the babeld protocol has not changed. Also, I don't see a reason for urgency in upgrading the firmware version of babeld, because we have not observed any crashes on the routers. Curious to hear your thoughts.

[jhpoelen]

A proposal is to split into two babeld upgrade issues: one for exit node, one for firmware.

[paidforby]

Good point, I was assuming it was a bit like the tunneldigger upgrade where everybody needs to be using the same version. Presumably all subversions of babeld v1 are compatible all other subversions (is this true?). Regardless, I would say that it would be worth upgrading babeld used by the firmware to proactively avoid any future complications due to using an out-dated version. I'd agree with splitting the issue into to separate issues in their respective repos.

[jech]

Here, I am assuming that the babeld protocol has not changed.

The core protocol remains compatible. The source-specific extension will change in an incompatible manner in version 1.9. If you don't know what source-specific routing is, then you're not concerned.

Also, I don't see a reason for urgency in upgrading the firmware version of babeld, because we have not observed any crashes on the routers.

The core protocol has remained compatible since version 0.90, back in 2008, so you should be fine. The full changelog is here: https://github.com/jech/babeld/blob/master/CHANGES

[bennlich]

Planned out an upgrade with @eenblam and @Juul today towards the end of the hacking workgroup. I just implemented the upgrade on the HE exit node, and everything seems to be working! My home node succeeded in getting routes.

See sudomesh/exitnode#15 for changes.