Commit Graph

3 Commits

Author SHA1 Message Date
Olaoluwa Osuntokun
7cbf0326c7
chanbackup: extend channel backups to include entire local+remote chan config
In this commit, we extend the prior Single format to include the entire
channel config, other than the constraints, but including the CSV delay
for both sides. We do this as we'll need more of the keying information
in order to properly execute the DLP protocol. Additionally, in the
future, if warranted, this would allow channels to be resumed if deemed
safe.
2019-03-28 17:53:38 -07:00
Olaoluwa Osuntokun
af1dfe176e
chanbackup: add new updateBackupFile method, write fresh backup on startup
In this commit, we modify the sub-swapper to update the set of backups
files time it's tarted. We do this to ensure that each time we start,
we're up to sync with the current set of open channels. This also ensure
that we'll create a new back up file if this is the first time we're
starting up with this new feature.
2019-03-28 17:53:30 -07:00
Olaoluwa Osuntokun
60999df08f
chanbackup: add new MultiFile struct for storing+updating Multis on disk
In this commit, we add a new MultiFile struct. We'll use this struct in
store the latest multi-channel backup on disk, swap it out atomically,
and finally extract+unpack the contents of the multi-file. The format
that's written to disk is the same as a regular Packed multi. The
contents of this new file are meant to be used to safely implement an
always up to date multi file on disk as a way for users to easily rsync
or fsnotiy (when it changes) the backup state of their channels.

We implement an atomic update and swap in the UpdateAndSwap. The method
uses relies on the underlying file system supporting an atomic rename
syscall. We first make a temporary backup file, write the latest
contents to that, then swap the temp file with the main file using
rename(2). This way, we ensure that we always have a single up to date
file, if the protocol aborts before the rename, then we can detect this,
remove the temp file, and attempt another swap.
2019-01-23 18:11:31 -08:00