Increase the number of open files limit for the sandboxed process to the
maximum allowed in the system. The maximum is obtained by reading the
/proc/sys/fs/nr_open sysctl file, and the setting is done using the setrlimit
syscall. Failure to read or parse the nr_open file, or to set the rlimit
results in a panic.
Signed-off-by: Ricardo Koller <ricarkol@gmail.com>
Implement support for setting up a sandbox for running the
service. The technique for this has been borrowed from virtiofsd, and
consists on switching to new PID, mount and network namespaces, and
then switching root to the directory to be shared.
Future patches will implement additional hardening features like
dropping capabilities and seccomp filters.
Signed-off-by: Sergio Lopez <slp@redhat.com>