File permissions to access/create/delete folders for multiple users

Question

I'm stuck on setting up FTP read/write file permissions (running FreeNAS). The read/write permissions for each user can follow the current format:

1. Users can read from all folders they have access to
2. Users can only write to/delete from their own user folders and any newly created folders.
3. Make it so that only uberuser1 and uberuser2 can create or delete folders.

Here I know how to handle #1 and #2 but I have no idea if #3 is possible when #2 will occur.

And all rest of my problem below for the FTP (on ProFTPD) directory which looks like:

/

- Main_Folder_1
-- user1
-- user2
-- user3
-- uberuser1
-- uberuser2

- Main_Folder_2
-- user4
-- user5
-- uberuser1
-- uberuser2

1. Users uberuser1 and uberuser2 should have access to /, as well as both the Main_Folder_1 and Main_Folder_2 folders.
2. When users1 to user3 log in, they should start inside the Main_Folder_1 folder. They should not be aware that there is a Main_Folder_2 folder at all, nor should they be able to navigate up into /.
3. Similarly, when user user4 or user5 logs in, he should start inside the Main_Folder_2 folder. They should not be aware that there is a Main_Folder_1 folder either, nor should he be able to navigate up into /.

No. 1 - no problem but how to get #2 and #3? I can create new groups MF1 and MF2 for each of those users which will limit access to those folders but how can I set chroot for them to their main folders when after log in to the FTP they are landing into / folder and see both main folders?

Answer 1

Well, I have got it to work in 99%

First I have created groups: MF, MF1 and MF2. Then I have added all users including uberusers to the MF group. Next user1 through user3 where added to the MF1 group then user4 and user5 to the MF2 group.

I have set permissions for Main_Folder_1 and Main_Folder_2 to be sure belongs to the MF group.

Next step it was editing proftpd.conf file to be sure users are chrooted to selected folders. Edited lines were

DefaultRoot ~ !wheel !MF1 !MF2
DefaultRoot ~/Main_Folder_1 MF1
DefaultRoot ~/Main_Folder_2 MF2

After FTP service restart I had working restricted users to selected folders.