[Samba] Samba 4.19.4 as printer server: printer are not show in browser

[Dario Lesca]

Il giorno mer, 07/02/2024 alle 13.18 +0100, Dario Lesca via samba ha
scritto:
> Now I do some other test and investigations (revert the snapshot to
> initial situation) 

I have do some test and I have found what can unlock the missing CUPS
printers list when do a "smbclient -L server" or browse the server from
windows.

See these follow steps[1].

As you see, it's not a SElinux problem, but I do not know what's
happened.

Only after I perform at least one print on a manually added dumb
printer (lp1) the list of printers shared by CUPS is shown!!

Before to print, when the CUPS printer are not show, I have stop smb
and nmb and I have copy the /var/lib/samba dir into a backup temp dir
(/opt/lib-samba-before)

Then I have restart smb/nmb and I have print a job, stop the services
and copied the /var/lib/samba dir again to check the differences
(/opt/lib-samba-after)

These are the difference[2]

I need some suggestions on how to investigate this strange behaviour
and what causes it and fill a bugs on the specific scope (Fedora?,
CUPS?, Samba?).

Many thanks

Dario

[1]
# Install a fresh Fedora 39 server

# Install cups
dnf install cups -y
systemctl restart cups

# Add a fake printer
lpadmin -p laser1 -oraw -v socket://laser1:9100/ -E

# Install another virtual printer (cups-PDF)
dnf install cups-pdf -y

# Check CUPS printers list
lpstat -t
# CUPS printers are listed

# Install and start samba
dnf install samba samba-client -y
systemctl restart smb nmb

# List printers
smbclient -N -L fedora
# CUPS printers list is NOT show

# add a dumb printer
cat << EOF >> /etc/samba/smb.conf
[lp1]
        comment = LP1 Printer
        path = /var/tmp
        printable = Yes
        browseable = Yes
	printer name = Cups-PDF
	public = yes
EOF

# disable auth (or add a user to samba)
sed -i '/security = user/a\\tmap to guest = bad user' /etc/samba/smb.conf

# Check ..
testparm -s /etc/samba/smb.conf

# Restart samba
systemctl restart smb nmb

# List printers
smbclient -N -L fedora
# CUPS printers are NOT show
# are only displayed the manually added printer         

# Once Again ...
smbclient -N -L fedora
# CUPS printers are NOT show
# are only displayed the manually added printer         

# ....

# Print a simple job to dumb lp1 printer
smbclient -N //fedora/lp1 -c 'print /etc/issue'

# List printers
smbclient -N -L fedora
# from now and forever the list of CUPS printers will be shown

[2]

root at fedora:~# ls -F /opt/lib-samba-before
account_policy.tdb  browse.dat  drivers/  group_mapping.tdb  lock/  private/  registry.tdb  share_info.tdb  smbprofile.tdb
 
root at fedora:~# ls -F /opt/lib-samba-after/
account_policy.tdb  browse.dat  drivers/  DriverStore/  group_mapping.tdb  lock/  printing/  private/  registry.tdb  share_info.tdb  smbprofile.tdb


root at fedora:~# ls -Fa /opt/lib-samba-before/drivers/
./  ../

root at fedora:~# ls -Fa /opt/lib-samba-after/drivers/
./  ../  ARM64/  color/  IA64/  W32ALPHA/  W32MIPS/  W32PPC/  W32X86/  WIN40/  x64/

root at fedora:~# ls -Fa /opt/lib-samba-after/DriverStore/
./  ../  FileRepository/  Temp/