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Printing with a Brother MFC-7460DN laser printer on Fedora Linux 33

This is a follow-up to my previous post Configuring a Brother MFC-7460DN Laser Printer/Scanner on Fedora 23 (64-bit), as things have fortunately changed to the better in the meanwhile.

As described in this post, setting up this printer in CUPS on Fedora has become quite an ordeal, as Brother no longer updates the printer drivers for these old models and they don’t provide 64 bit binaries.

As I had to switch laptops a few weeks ago, I had to reinstall Linux from scratch and needed to reconfigure my printer settings as well. As I did not want to go through the same hoops again, I did some research and was happy to learn that Peter De Wachter has been working on an open source version of CUPS printer drivers for a wide range of Brother laser printers, which include the MFC-7460DN as well!

Sadly, the printer-driver-brlaser package is not part of the Fedora Linux distribution (yet), so I again had to go out and scour the usual places for a suitable RPM package. Luckily, an RPM package is available from the openSUSE Build Service! There’s no dedicated Fedora package, but downloading and installing the driver package for the openSUSE Tumbleweed distribution worked flawlessly.

To set up the printer, first download and install the RPM package directly from the build service repo:

$ sudo dnf install https://download.opensuse.org/repositories/Printing/openSUSE_Tumbleweed/x86_64/printer-driver-brlaser-6+git20200420.9d7ddda-21.4.x86_64.rpm

The actual URL may vary if the package version is updated, so check the download page for the latest version if the download fails.

Now you can set up the printer using the usual CUPS printer configuration tools. In the printer driver selection box, choose “Brother MFC-7460DN, using brlaser v6” and you’re all set!

BTW, this works on Ubuntu Linux as well, they actually include the driver in their core distribution. However, the MFC-7460DN model is not listed explicitly in the driver selection, but choosing any other brlaser device just works.

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Configuring a Brother MFC-7460DN Laser Printer/Scanner on Fedora 23 (64-bit)

Update: the MFC-7460DN printer is now supported via the brlaser open source printer driver by Peter De Wachter. See this post for a much simpler way to configure this printer on Fedora (and other Linux distributions).

I’ve always been a fan of Brother, as their devices usually come with decent support for the Linux OS (at least initially). I have an MFC-7460DN Laser Printer / Scanner in my home office, that worked fine with Ubuntu Linux for the past few years. It’s hooked up to my DSL router’s ethernet switch and acts like a network printer for all of our devices.

Just to keep my mind flexible and to take a look at another Linux distribution for a change, I recently started using Fedora Workstation 23 on my Laptop (a company-issued Lenovo ThinkPad T440s). While the OS installation was painless and all main components like Video, Audio, Networking were detected and configured correctly out of the box, the post-installation of some tools and services required some more effort.

This time, the printing part of the MFC-7460DN took me quite some time to figure out. While Brother provides RPM packages of the drivers, they are 32-bit only, and the instructions hadn’t been updated since Fedora 12. The first thing I had to do was to download two driver RPM packages. I initially started with the newer versions of the drivers, brgenml1cupswrapper-3.1.0 and brgenml1lpr-3.1.0, but somehow did not get them to work at all. I then tried the older packages, mfc7460dnlpr-2.1.0 and cupswrapperMFC7460DN-2.0.4. These installed flawlessly, and a new printer was added to the CUPS configuration automatically.

However, it was configured as a local printer, so I first had to change the existing configuration to talk to the remote LPD port instead. While the printer configuration looked correct and no errors showed up, all print jobs simply disappeared into the bit bucket, without any visible error on the application side. Unfortunately the web-based CUPS administration tool was not much helpful, either – the button View Error Log simply returned a “Not found” error. There was no error log file in /var/log/cups, so I queried the status of the CUPS service via systemd next.

The command systemctl status -l cups then gave me a first hint:

sh: /opt/brother/Printers/BrGenML1//lpd/rawtobr3: /lib/ld-linux.so.2: bad ELF interpreter: No such file or directory

Since this is a 32-bit binary, it might help to actually install a 32-bit version of the GNU C library! I simply forgot this step, even though it’s documented in the installation instructions. A simple dnf install glibc.i686 got me over this hurdle.

Unfortunately the print jobs still did not reach the printer and disappeared in the void! Checking the CUPS error log again, I now saw this:

/usr/local/Brother/Printer/MFC7460DN/lpd/filterMFC7460DN: line 131: 11660 Done                    eval cat $INPUT_TEMP
11661 Broken pipe             | $PSCONV $PSCONV_OP
11662 Segmentation fault      | $BRCONV $BRCONV_OP
PID 11602 (/usr/lib/cups/filter/brlpdwrapperMFC7460DN) exited with no errors.
PID 11603 (/usr/lib/cups/backend/lpd) exited with no errors.

Hilarious. Oh well, maybe the 32-bit binary is simply too old and crashes in the new environment? Let’s take a look at the full systemd journal with journalctl! This gave me further clues:

cupsd[10951]: /usr/local/Brother/Printer/MFC7460DN/lpd/filterMFC7460DN: line 131: 11660 Done                    eval cat $INPUT_TEMP
cupsd[10951]: 11661 Broken pipe             | $PSCONV $PSCONV_OP
cupsd[10951]: 11662 Segmentation fault      | $BRCONV $BRCONV_OP
cupsd[10951]: PID 11602 (/usr/lib/cups/filter/brlpdwrapperMFC7460DN) exited with no errors.
cupsd[10951]: PID 11603 (/usr/lib/cups/backend/lpd) exited with no errors.
cupsd[10951]: time-at-completed=1449759139
cupsd[10951]: Job completed.
cupsd[10951]: Removing document files.
dbus[1190]: [system] Successfully activated service 'org.fedoraproject.Setroubleshootd'
setroubleshoot[11624]: SELinux is preventing brprintconflsr3 from using the execmem access on a process. For complete SELinux messages. run sealert -l 5d873063-1d87-4e82-b
python3[11624]: SELinux is preventing brprintconflsr3 from using the execmem access on a process.
                                                
                                *****  Plugin catchall_boolean (89.3 confidence) suggests   ******************
                           
                                If you want to allow cups to execmem
                                Then you must tell SELinux about this by enabling the 'cups_execmem' boolean.
                                                
                                Do
                                setsebool -P cups_execmem 1
                                                
                                *****  Plugin catchall (11.6 confidence) suggests   **************************
                                                
                                If you believe that brprintconflsr3 should be allowed execmem access on processes labeled cupsd_t by default.
                                Then you should report this as a bug.
                                You can generate a local policy module to allow this access.
                                Do
                                allow this access for now by executing:
                                # grep brprintconflsr3 /var/log/audit/audit.log | audit2allow -M mypol
                                # semodule -i mypol.pp

OK, so SELinux seems to be getting in the way here. I did as suggested and ran the following commands:

# setsebool -P cups_execmem 1
# grep brprintconflsr3 /var/log/audit/audit.log | audit2allow -M brothermfc7460dn
# semodule -i brothermfc7460dn.pp

An lo and behold, the printer started printing! Let’s hope it still does when I reboot the system…

Things I learned and that surprised me:

  • The error handling in CUPS completely failed here. There was not a single end-user accessible hint that something went wrong, the print jobs just disappeared in the void.
  • The move to systemd still has some ripple effects, e.g. the “Not found” error for the missing CUPS error log in the web UI.
  • Analyzing log files with journalctl is actually quite convenient. Instead of grepping and tailing multiple logs under /var/log/, these tasks can now be performed using a single tool.
  • SELinux is still a bitch, even though the hints provided by setroubleshootd were quite useful to resolve the issues at hand.