Expose ability to limit redirect to source IPs

[n-connect]

Connected to issue #761 the first batch of changes in a PR -> extending expose to be able to handle source IP limitations on jail (bhyve[?]) redirects.

Looking for the expansion of CBSD, ClonOS, myBee, XigmaNAS plugins, QT app, I think its fits into to direction, eg. CBSD can have better FW control and be able to merge into / handle host's own pf (beside the existing %CBSDWORKDIR%/etc/pf.conf)

These commits add:

• additional column to system-wide expose sqlite shema,
• adds the capability to tools/expose to specify source IPs for redirects

To be added -> howto handle the existing host pf.conf:

• the logic and oneliners can be used from my last comment from cbsd expose clears host's existing pf rules #761
• question is where to add the subroutine, expose, naton, natcfg

@olevole,

I've had difficulties make work the SQLite's default values even with "NOT NULL". If you know the working way, please let me know -> two exception handling can be removed.

Also, no migration script added:

• existing tables to be upgraded,
• more interesting: existong pfrdr.conf to be managed (or recreated). The harder

[olevole]

@n-connect fantastic! Yeah, I remember you asking about that. However, I am not using pf at this time so could not find an opportunity to do the job.

Yes, the migration of the scheme is relevant, I will return to this issue a little later when I test it before the next release. Thank you!

[n-connect]

Thanks!

Since my last post here, have found the proper way handling the default values in SQLite during add rows:

• when creating a new row, one needs to simply omit / not add the column name in question and the default value will be created. It can be applied for expose to be more elegant.
• So expect some fine-tunes/fixes for expose in the future
• Also tests we are very welcome

I'm testing & thinking about how, and where to put the code for merging with the overall host pf.conf as the second layer for this functionality, hence the testing with XigmaNAS with the full vs. embedded.