pam_mkhomedir: add copymode option to keep the mode of each subfiles/subfolders from skeleton

[keentux]

With the command mkhomedir_helper $new_user $u_mask $skeleton_path, the new user home directory is created from the skeleton, but without same permissions on sub directories.

Fix #497

Signed-off-by: Valentin Lefebvre valentin.lefebvre@suse.com

[ldv-alt]

Why do you suggest copying directory permissions from the skeleton directory?
How would this interact with umask option?

[keentux]

I made a mistake by wanting to copy sub-directories permissions from the default skeleton, directory.
I was trying to fix the issue #497. As explained in this one, we could have a use case where we could want to copy an existing home directory for a new user. And so, we could think to keep same permissions.

May I suggest checking if skeleton_path has been changed by arguments and so, keep same permissions of sub-directories ? Keeping the umask option effective to let the possibility to adapt default permissions.

Do you agree with that @ldv-alt ? In that case I will change my PR 👍

[ldv-alt]

I don't feel comfortable with changing a traditional behaviour like this. What do you think about adding a new option? Anyway, please make sure this new mode interacts with umask option in a sensible way. I suppose this interaction would have to be described in the documentation, too.

[keentux]

Tanks for your comment ! I fully agree to add a new option.
I was thinking of adding a sixth option called "dir_mode", dealing with the value "copymode" (a not mandatory one). For umask, I will keep the same previous behavior: compute with all sub-directories.

I am going to update this request and add this new option following by this man documentation.

[keentux]

Thank you for the review, and sorry for these mistakes, I was not able to see straight. I update the documentation and change the correct chmod().

[ldv-alt]

Sorry, I don't understand your latest changes. Why do you want to change umask every time create_homedir is called?

Also, why do you change just the helper? Don't you think pam_mkhomedir needs an option, too?

[keentux]

I was basing to what it was done for files. Especially here: https://github.com/linux-pam/linux-pam/blob/master/modules/pam_mkhomedir/mkhomedir_helper.c#L266. Where it keeps the same access permissions to the new file from the original one in the skeleton.
As create_homedir is called recursively for each sub-folders, I thought it would be a good idea to update the chmod() call in this function. And keep the same access permission from the skeleton tree if copymode is selected for the current folder (home directory's access permission will be changed after the call of the function into create_homedir_helper).

Initially, I wanted to fix the linked issue. However, your are right, I should also expend this update to the pam_mkhomedir. If you agree with my latest changes, I will do the job to update mkhome_dir module.

[ldv-alt]

To be honest, this description looks confusing to me. It's not clear whether this parameter can be set yo anything besides copymode, and how it interacts with umask.

[keentux]

Agree. I try to simplify this one with the last modifications

[BenBE]

Two minor style notes.