Mailing List Archive: DBMail: users

How to prevent folder deletion (by owner) and/or prevent messages being deleted when a folder is deleted

Index | Next | Previous | View Threaded

daniel at cwa

Jan 10, 2012, 4:05 AM

Post #1 of 2 (182 views)
Permalink

How to prevent folder deletion (by owner) and/or prevent messages being deleted when a folder is deleted

Hi

I appreciate this has been discussed before but I don’t believe there was a
solution given which met my needs so I thought I’d run this by the list.

I would like to prevent the owner of a mailbox deleting it, the reason being
that if this is done accidently or maliciously the child messages are
removed from the dbmail database and not recoverably without a major effort
involving recovery from backups. Normally of course if someone accidently
(or maliciously) deletes a message and even purges it the message remains in
the database until dbmail-util is run with the correct flags. Unfortunately
it is quite frequent for there to be a delay between a user deleting folder
and this being brought to anyone’s attention. I’m sure everyone can imagine
the user/admin conversations which have arisen as a result of user “finger
trouble” etc.

Changing the permission flag in dbmail_mailboxes to 1 (from 2) has been
suggested. This prevents a user deleting the mailbox but also prevents all
changes to messages in the mailbox (or adding messages to it) which is too
restrictive.

Using ACL permissions has also been suggested but this doesn’t help because
the owner always has delete permission on their own mailbox. I suppose I
could set up a system where all mailboxes are shared and people are not the
owner of their “own” mailboxes but this seems like a lot of trouble given
we have several thousand mailboxes.

I considered changing the permissions on the dbmail_mailboxes table for the
dbmail user to prevent deletion but then realised that using MySQL I would
have to remove all the dbmail uers permissions (which are currently “grant
all” on the dbmail database) and set permissions one at a time for each
table, doable and I expect this is the approach I should take, but I’d be
concerned about such a level of interference on a production system.

So, would the best “quick fix” for me be to remove the foreign key
constraints to prevent the deletion of a mailbox having the knock-on effect
(i.e. of deleting all the contained messages from the folder from the
database) which I’m trying to avoid? If so, should I just remove the
dbmail_messages_ibfk_2 on dbmail_messages (cascade constraint on
dbmail_mailboxes mailbox_idnr/mailbox_idnr). If I make this change does
anyone know of any possible unforeseen consequences? The only one I can
envisage is a situation where a mailbox is deleted and then another created
(which I imagine could potentially have the same mailbox_idnr).

Clearly I’d prefer a dbmail “flag” or folder permission setting which
achieves the same goal and if that exists I trust someone will let me know.

Thank you!

Daniel Schütze

paul at nfg

Jan 10, 2012, 6:11 AM

Post #2 of 2 (171 views)
Permalink

Re: How to prevent folder deletion (by owner) and/or prevent messages being deleted when a folder is deleted [In reply to]

On 01/10/2012 01:05 PM, Daniel Schütze wrote:

> So, would the best “quick fix” for me be to remove the foreign key
> constraints to prevent the deletion of a mailbox having the knock-on
> effect (i.e. of deleting all the contained messages from the folder from
> the database) which I’m trying to avoid? If so, should I just remove
> the dbmail_messages_ibfk_2 on dbmail_messages (cascade constraint on
> dbmail_mailboxes mailbox_idnr/mailbox_idnr). If I make this change does
> anyone know of any possible unforeseen consequences? The only one I can
> envisage is a situation where a mailbox is deleted and then another
> created (which I imagine could potentially have the same mailbox_idnr).

If you remove that cascading constraint, messages in such a deleted
inbox become unconnected. This will lead to them being harvested by
dbmail-util -cy (implied by -ay). So you might want to re-assign those
messages to a newly created archive box before running that.

--
________________________________________________________________
Paul J Stevens pjstevns @ gmail, twitter, skype, linkedin

* Premium Hosting Services and Web Application Consultancy *

www.nfg.nl/info [at] nfg/+31.85.877.99.97
________________________________________________________________
_______________________________________________
DBmail mailing list
DBmail [at] dbmail
http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail

Index | Next | Previous | View Threaded

Interested in having your list archived? Contact Gossamer Threads