ifupdown2 will run all scripts regardless of the execute bit being set

[gedia]

Hello,

I believe I've found a point where ifupdown2 behaviour significantly diverges from ifupdown on debian stretch. I'm using ifupdown2-1.2.1 and I needed to replace the stock /etc/network/if-up.d/openssh-server script with a custom version of it, so I used dpkg-divert to rename the original file and then removed the execute bit from the diverted version.

Original ifupdown uses run-parts which supposedly doesn't run non-executable files in the directory. However, ifupdown2 doesn't seem to make this distinction. Is it possible to make ifupdown2 behave similarly to ifupdown in this respect?

[roopa-prabhu]

yes, we should be able to fix it. Thanks for reporting the issue.

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On Wed, Jan 9, 2019 at 7:41 AM George Diamantopoulos < ***@***.***> wrote: Hello, I believe I've found a point where ifupdown2 behaviour significantly diverges from ifupdown on debian stretch. I'm using ifupdown2-1.2.1 and I needed to replace the stock /etc/network/if-up.d/openssh-server script with a custom version of it, so I used dpkg-divert to rename the original file and then removed the execute bit from the diverted version. Original ifupdown uses run-parts which supposedly doesn't run non-executable files in the directory. However, ifupdown2 doesn't seem to make this distinction. Is it possible to make ifupdown2 behave similarly to ifupdown in this respect? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#89>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AE3Mvs0IG6Uglc6N75yAHZqPDcdjq1tfks5vBg2xgaJpZM4Z3vWL> .

[julienfortin]

Hello @gedia,

Can you please provide ifup -a -d output? I'm not able to reproduce, see logs below:

[6:50:41] root:if-up.d # cat no_permission_ls.sh
ls -l
[6:50:42] root:if-up.d # ll no_permission_ls.sh
-rw-r--r-- 1 root root 6 Jan 16 06:50 no_permission_ls.sh
[6:50:48] root:if-up.d # ifup -a
error: lo : lo: up cmd '/etc/network/if-up.d/no_permission_ls.sh' failed ([Errno 13] Permission denied)
error: enp0s3 : enp0s3: up cmd '/etc/network/if-up.d/no_permission_ls.sh' failed ([Errno 13] Permission denied)

[roopa-prabhu]

@julienfortin instead of error'ing out, the ask is to not try to execute the script

[julienfortin]

@roopa-prabhu I'm afraid that this might confuse users who won't pay attention to the permission on the file, and might wonder why their script is not executed..?
Maybe we can have a log info "Permission denied" ?

[roopa-prabhu]

@julienfortin good idea.

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On Wed, Jan 16, 2019 at 6:12 PM Julien Fortin ***@***.***> wrote: @roopa-prabhu I'm afraid that this might confuse users who won't pay attention to the permission on the file, and might wonder why their script is not executed..? Maybe we can have a log info "Permission denied" ? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[gedia]

Actually, what prompted me to open this issue is that when systemd restarts networking, for example, the failure of the script's execution will also cause the systemd unit to fail.

Printing a "Permission denied" error is, of course, desirable, but my main concern here is that the networking systemd service unit will exit cleanly (sorry, I should have elaborated more in my initial report).