These files specify which kernel modules Shorewall will load before trying to determine your iptables/kernel's capabilities.
The modules file is used when LOAD_HELPERS_ONLY=No in shorewall.conf(8); the helpers file is used when LOAD_HELPERS_ONLY=Yes
Beginning with Shorewall 5.2.3, the LOAD_HELPERS_ONLY option has been removed and the behavior is the same as if LOAD_HELPERS_ONLY=Yes was specified.
Each record in the files has the following format:
loadmodule modulename [moduleoption...]
The modulename names a kernel module (without suffix). Shorewall will search for modules based on your MODULESDIR setting in shorewall.conf(8). The moduleoptions are passed to modprobe (if installed) or to insmod.
The /usr/share/shorewall/modules file contains a large number of modules. Users are encouraged to copy the file to /etc/shorewall/modules and modify the copy to load only the modules required or to use LOAD_HELPERS_ONLY=Yes..if n .sp
If you build monolithic kernels and have not installed module-init-tools, then create an empty /etc/shorewall/modules file; that will prevent Shorewall from trying to load modules at all.
loadmodule ip_conntrack_ftp ports=21,221
The man page shorewall6-modules(5) is an alias of shorewall-modules(5).