man firejail

FIREJAIL(1)                    firejail man page                   FIREJAIL(1)

NAME
       Firejail - Linux namespaces sandbox program

SYNOPSIS
       Start a sandbox:

              firejail [OPTIONS] [program and arguments]

       File transfer from an existing sandbox

              firejail {--ls | --get | --put} dir_or_filename

       Network traffic shaping for an existing sandbox:

              firejail --bandwidth={name|pid} bandwidth-command

       Monitoring:

              firejail {--list | --netstats | --top | --tree}

       Miscellaneous:

              firejail  {-? | --debug-caps | --debug-errnos | --debug-syscalls
              | --debug-protocols | --help | --version}

DESCRIPTION
       Firejail is a SUID sandbox program that reduces the  risk  of  security
       breaches  by  restricting the running environment of untrusted applica‐
       tions using Linux namespaces, seccomp-bpf and Linux  capabilities.   It
       allows a process and all its descendants to have their own private view
       of the globally shared kernel resources, such  as  the  network  stack,
       process table, mount table.  Firejail can work in a SELinux or AppArmor
       environment, and it is integrated with Linux Control Groups.

       Written in C with virtually no dependencies, the software runs  on  any
       Linux  computer with a 3.x kernel version or newer.  It can sandbox any
       type of processes: servers, graphical applications, and even user login
       sessions.

       Firejail  allows the user to manage application security using security
       profiles.  Each profile defines a set of  permissions  for  a  specific
       application  or  group  of applications. The software includes security
       profiles for a number of more common Linux programs,  such  as  Mozilla
       Firefox, Chromium, VLC, Transmission etc.

USAGE
       Without  any  options,  the sandbox consists of a filesystem build in a
       new mount namespace, and new PID and UTS namespaces. IPC,  network  and
       user  namespaces  can  be  added  using  the  command line options. The
       default Firejail filesystem is based on the host  filesystem  with  the
       main  system directories mounted read-only. These directories are /etc,
       /var, /usr, /bin, /sbin, /lib, /lib32, /libx32 and /lib64.  Only  /home
       and /tmp are writable.

       As it starts up, Firejail tries to find a security profile based on the
       name of the application.  If an appropriate profile is not found, Fire‐
       jail will use a default profile.  The default profile is quite restric‐
       tive. In case the application doesn't work, use --noprofile  option  to
       disable  it. For more information, please see SECURITY PROFILES section
       below.

       If a program argument  is  not  specified,  Firejail  starts  /bin/bash
       shell.  Examples:

       $ firejail [OPTIONS]                # starting a /bin/bash shell

       $ firejail [OPTIONS] firefox        # starting Mozilla Firefox

       # sudo firejail [OPTIONS] /etc/init.d/nginx start

OPTIONS
       --     Signal  the  end of options and disables further option process‐
              ing.

       --allow-debuggers
              Allow tools such  as  strace  and  gdb  inside  the  sandbox  by
              whitelisting  system  calls  ptrace  and  process_vm_readv. This
              option is only available when running on Linux  kernels  4.8  or
              newer  - a kernel bug in ptrace system call allows a full bypass
              of the seccomp filter.

              Example:
              $  firejail    --allow-debuggers   --profile=/etc/firejail/fire‐
              fox.profile strace -f firefox

       --allusers
              All  directories  under /home are visible inside the sandbox. By
              default, only current user home directory is visible.

              Example:
              $ firejail --allusers

       --apparmor
              Enable AppArmor confinement. For more  information,  please  see
              APPARMOR section below.

       --appimage
              Sandbox an AppImage (https://appimage.org/) application.

              Example:
              $ firejail --appimage krita-3.0-x86_64.appimage
              $ firejail --appimage --private krita-3.0-x86_64.appimage
              $ firejail --appimage --net=none --x11 krita-3.0-x86_64.appimage

       --audit
              Audit the sandbox, see AUDIT section for more details.

       --audit=test-program
              Audit the sandbox, see AUDIT section for more details.

       --bandwidth=name|pid
              Set  bandwidth limits for the sandbox identified by name or PID,
              see TRAFFIC SHAPING section for more details.

       --bind=filename1,filename2
              Mount-bind filename1 on top of filename2. This  option  is  only
              available when running as root.

              Example:
              # firejail --bind=/config/etc/passwd,/etc/passwd

       --blacklist=dirname_or_filename
              Blacklist  directory  or  file.  File globbing is supported, see
              FILE GLOBBING section for more details.

              Example:
              $ firejail --blacklist=/sbin --blacklist=/usr/sbin
              $ firejail --blacklist=~/.mozilla
              $ firejail "--blacklist=/home/username/My Virtual Machines"
              $ firejail --blacklist=/home/username/My\ Virtual\ Machines

       --build
              The command builds a whitelisted profile. The profile is printed
              on the screen. If /usr/bin/strace is installed on the system, it
              also builds a whitelisted seccomp profile. The program is run in
              a  very  relaxed sandbox, with only --caps.drop=all and --nonew‐
              privs. Programs that raise user privileges are not supported  in
              order  to  allow  strace  to  run.  Chromium  and Chromium-based
              browsers will not work.

              Example:
              $ firejail --build=profile-file vlc ~/Videos/test.mp4

       --build=profile-file
              The command builds a whitelisted profile, and saves it  in  pro‐
              file-file.  If  /usr/bin/strace  is  installed on the system, it
              also builds a whitelisted seccomp profile. The program is run in
              a  very  relaxed sandbox, with only --caps.drop=all and --nonew‐
              privs. Programs that raise user privileges are not supported  in
              order  to  allow  strace  to  run.  Chromium  and Chromium-based
              browsers will not work.

              Example:
              $ firejail --build=vlc.profile vlc ~/Videos/test.mp4

       -c     Execute command and exit.

       --caps Linux capabilities is a kernel feature designed to split up  the
              root  privilege into a set of distinct privileges.  These privi‐
              leges can be enabled or disabled independently, thus restricting
              what a process running as root can do in the system.

              By  default  root  programs  run  with all capabilities enabled.
              --caps option disables the following capabilities:  CAP_SYS_MOD‐
              ULE, CAP_SYS_RAWIO, CAP_SYS_BOOT, CAP_SYS_NICE, CAP_SYS_TTY_CON‐
              FIG,  CAP_SYSLOG,  CAP_MKNOD,  CAP_SYS_ADMIN.   The  filter   is
              applied to all processes started in the sandbox.

              Example:
              $ sudo firejail --caps /etc/init.d/nginx start

       --caps.drop=all
              Drop  all capabilities for the processes running in the sandbox.
              This option is recommended for running GUI programs or any other
              program  that doesn't require root privileges. It is a must-have
              option for sandboxing untrusted programs installed from  unoffi‐
              cial sources - such as games, Java programs, etc.

              Example:
              $ firejail --caps.drop=all warzone2100

       --caps.drop=capability,capability,capability
              Define a custom blacklist Linux capabilities filter.

              Example:
              $ firejail --caps.drop=net_broadcast,net_admin,net_raw

       --caps.keep=capability,capability,capability
              Define a custom whitelist Linux capabilities filter.

              Example:
              $   sudo   firejail  --caps.keep=chown,net_bind_service,setgid,\
              setuid /etc/init.d/nginx start

       --caps.print=name|pid
              Print the caps filter for the sandbox identified by name  or  by
              PID.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --caps.print=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --caps.print=3272

       --cgroup=tasks-file
              Place  the sandbox in the specified control group. tasks-file is
              the full path of cgroup tasks file.

              Example:
              # firejail --cgroup=/sys/fs/cgroup/g1/tasks

       --chroot=dirname
              Chroot the sandbox into a root filesystem.  Unlike  the  regular
              filesystem  container,  the system directories are mounted read-
              write. If the sandbox is started as a regular user, default sec‐
              comp  and  capabilities  filters are enabled. This option is not
              available on Grsecurity systems.

              Example:
              $ firejail --chroot=/media/ubuntu warzone2100

       --cpu=cpu-number,cpu-number,cpu-number
              Set CPU affinity.

              Example:
              $ firejail --cpu=0,1 handbrake

       --cpu.print=name|pid
              Print the CPU cores in use by the sandbox identified by name  or
              by PID.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --cpu.print=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --cpu.print=3272

       --csh  Use /bin/csh as default user shell.

              Example:
              $ firejail --csh

       --debug
              Print debug messages.

              Example:
              $ firejail --debug firefox

       --debug-blacklists
              Debug blacklisting.

              Example:
              $ firejail --debug-blacklists firefox

       --debug-caps
              Print  all recognized capabilities in the current Firejail soft‐
              ware build and exit.

              Example:
              $ firejail --debug-caps

       --debug-check-filename
              Debug filename checking.

              Example:
              $ firejail --debug-check-filename firefox

       --debug-errnos
              Print all recognized error numbers in the current Firejail soft‐
              ware build and exit.

              Example:
              $ firejail --debug-errnos

       --debug-private-lib
              Debug messages for --private-lib option.

       --debug-protocols
              Print  all recognized protocols in the current Firejail software
              build and exit.

              Example:
              $ firejail --debug-protocols

       --debug-syscalls
              Print all recognized system calls in the current Firejail  soft‐
              ware build and exit.

              Example:
              $ firejail --debug-syscalls

       --debug-whitelists
              Debug whitelisting.

              Example:
              $ firejail --debug-whitelists firefox

       --defaultgw=address
              Use  this  address  as default gateway in the new network names‐
              pace.

              Example:
              $ firejail --net=eth0 --defaultgw=10.10.20.1 firefox

       --disable-mnt
              Disable /mnt, /media, /run/mount and /run/media access.

              Example:
              $ firejail --disable-mnt firefox

       --dns=address
              Set a DNS server for the sandbox. Up to three DNS servers can be
              defined.   Use  this  option if you don't trust the DNS setup on
              your network.

              Example:
              $ firejail --dns=8.8.8.8 --dns=8.8.4.4 firefox

              Note: this feature is not supported on systemd-resolved setups.

       --dns.print=name|pid
              Print DNS configuration for a sandbox identified by name  or  by
              PID.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --dns.print=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --dns.print=3272

       --env=name=value
              Set environment variable in the new sandbox.

              Example:
              $ firejail --env=LD_LIBRARY_PATH=/opt/test/lib

       --force
              By  default,  if  Firejail is started in an existing sandbox, it
              will run the program in a bash shell.  This option disables this
              behavior,  and  attempts to start Firejail in the existing sand‐
              box.  There could be lots of reasons for it to fail, for example
              if  the existing sandbox disables admin capabilities, SUID bina‐
              ries, or if it runs seccomp.

       --fs.print=name|print
              Print the filesystem log for the sandbox identified by  name  or
              by PID.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --fs.print=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --fs.print=3272

       --get=name|pid filename
              Get a file from sandbox container, see FILE TRANSFER section for
              more details.

       --git-install
              Download, compile and install mainline git version  of  Firejail
              from  the  official  repository  on  GitHub.   The  software  is
              installed in /usr/local/bin, and takes precedence over the (old)
              version installed in /usr/bin. If for any reason the new version
              doesn't work, the user can uninstall  it  using  --git-uninstall
              command and revert to the old version.

              Prerequisites:  git  and  compile  support are required for this
              command to  work.  On  Debian/Ubuntu  systems  this  support  is
              installed using "sudo apt-get install build-essential git".

              Example:

              $ firejail --git-install

       --git-uninstall
              Remove    the   Firejail   version   previously   installed   in
              /usr/local/bin using --git-install command.

              Example:

              $ firejail --git-uninstall

       -?, --help
              Print options end exit.

       --hostname=name
              Set sandbox hostname.

              Example:
              $ firejail --hostname=officepc firefox

       --hosts-file=file
              Use file as /etc/hosts.

              Example:
              $ firejail --hosts-file=~/myhosts firefox

       --ignore=command
              Ignore command in profile file.

              Example:
              $ firejail --ignore=shell --ignore=seccomp firefox

       --interface=interface
              Move interface in a new network namespace. Up to  four  --inter‐
              face  options can be specified.  Note: wlan devices are not sup‐
              ported for this option.

              Example:
              $ firejail --interface=eth1 --interface=eth0.vlan100

       --ip=address
              Assign IP addresses to the last network interface defined  by  a
              --net option. A default gateway is assigned by default.

              Example:
              $ firejail --net=eth0 --ip=10.10.20.56 firefox

       --ip=none
              No IP address and no default gateway are configured for the last
              interface defined by a --net option. Use this option in case you
              intend to start an external DHCP client in the sandbox.

              Example:
              $ firejail --net=eth0 --ip=none

              If  the  corresponding interface doesn't have an IP address con‐
              figured, this option is enabled by default.

       --ip6=address
              Assign IPv6 addresses to the last network interface defined by a
              --net option.

              Example:
              $ firejail --net=eth0 --ip6=2001:0db8:0:f101::1/64 firefox

              Note:  you don't need this option if you obtain your ip6 address
              from router via SLAAC (your ip6 address and default  route  will
              be configured by kernel automatically).

       --iprange=address,address
              Assign  an  IP address in the provided range to the last network
              interface defined by  a  --net  option.  A  default  gateway  is
              assigned by default.

              Example:
              $ firejail --net=eth0 --iprange=192.168.1.100,192.168.1.150

       --ipc-namespace
              Enable  a new IPC namespace if the sandbox was started as a reg‐
              ular user. IPC namespace is enabled  by  default  for  sandboxes
              started as root.

              Example:
              $ firejail --ipc-namespace firefox

       --join=name|pid
              Join  the  sandbox  identified  by  name or by PID. By default a
              /bin/bash shell is started after joining the sandbox.  If a pro‐
              gram  is specified, the program is run in the sandbox. If --join
              command is issued as a regular user, all  security  filters  are
              configured  for  the new process the same they are configured in
              the sandbox.  If --join command is issued as root, the  security
              filters,  cgroups and cpus configurations are not applied to the
              process joining the sandbox.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --join=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --join=3272

       --join-filesystem=name|pid
              Join the mount namespace of the sandbox identified  by  name  or
              PID.  By  default a /bin/bash shell is started after joining the
              sandbox.  If a program is specified, the program is run  in  the
              sandbox.  This command is available only to root user.  Security
              filters, cgroups and cpus configurations are not applied to  the
              process joining the sandbox.

       --join-network=name|PID
              Join the network namespace of the sandbox identified by name. By
              default a /bin/bash shell is started after joining the  sandbox.
              If  a  program  is specified, the program is run in the sandbox.
              This command is available only to root user.  Security  filters,
              cgroups  and  cpus configurations are not applied to the process
              joining the sandbox. Example:

              # start firefox
              $ firejail --net=eth0 --name=browser firefox &

              # change netfilter configuration
              $ sudo firejail --join-network=browser bash -c  "cat  /etc/fire‐
              jail/nolocal.net | /sbin/iptables-restore"

              # verify netfilter configuration
              $ sudo firejail --join-network=browser /sbin/iptables -vL

              # verify  IP addresses
              $ sudo firejail --join-network=browser ip addr
              Switching  to pid 1932, the first child process inside the sand‐
              box
              1: lo:   mtu  65536  qdisc  noqueue  state
              UNKNOWN group default
                  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
                  inet 127.0.0.1/8 scope host lo
                     valid_lft forever preferred_lft forever
                  inet6 ::1/128 scope host
                     valid_lft forever preferred_lft forever
              2:  eth0-1931:   mtu 1500 qdisc
              noqueue state UNKNOWN group default
                  link/ether 76:58:14:42:78:e4 brd ff:ff:ff:ff:ff:ff
                  inet  192.168.1.158/24  brd   192.168.1.255   scope   global
              eth0-1931
                     valid_lft forever preferred_lft forever
                  inet6 fe80::7458:14ff:fe42:78e4/64 scope link
                     valid_lft forever preferred_lft forever

       --join-or-start=name
              Join the sandbox identified by name or start a new one.  Same as
              "firejail --join=name" if sandbox with  specified  name  exists,
              otherwise same as "firejail --name=name ..."
              Note  that in contrary to other join options there is respective
              profile option.

       --ls=name|pid dir_or_filename
              List files in sandbox container, see FILE TRANSFER  section  for
              more details.

       --list List all sandboxes, see MONITORING section for more details.

              Example:
              $ firejail --list
              7015:netblue:firejail firefox
              7056:netblue:firejail --net=eth0 transmission-gtk
              7064:netblue:firejail --noroot xterm
              $

       --mac=address
              Assign  MAC addresses to the last network interface defined by a
              --net option.

              Example:
              $ firejail --net=eth0 --mac=00:11:22:33:44:55 firefox

       --machine-id
              Spoof id number in /etc/machine-id file - a  new  random  id  is
              generated inside the sandbox.

              Example:
              $ firejail --machine-id

       --memory-deny-write-execute
              Install a seccomp filter to block attempts to create memory map‐
              pings that are both writable and executable, to change  mappings
              to  be  executable,  or  to create executable shared memory. The
              filter  examines  the  arguments  of  mmap,   mmap2,   mprotect,
              pkey_mprotect  and  shmat  system calls and kills the process if
              necessary.

              Note: shmat is not implemented as a system call  on  some  plat‐
              forms including i386, and it cannot be handled by seccomp-bpf.

       --mtu=number
              Assign  a  MTU  value to the last network interface defined by a
              --net option.

              Example:
              $ firejail --net=eth0 --mtu=1492

       --name=name
              Set sandbox name. Several options, such as  --join  and  --shut‐
              down, can use this name to identify a sandbox.

              Example:
              $ firejail --name=mybrowser firefox

       --net=bridge_interface
              Enable  a  new  network  namespace and connect it to this bridge
              interface.  Unless specified with option --ip  and  --defaultgw,
              an  IP  address and a default gateway will be assigned automati‐
              cally to the sandbox. The  IP  address  is  verified  using  ARP
              before  assignment. The address configured as default gateway is
              the bridge device IP address. Up to four  --net  bridge  devices
              can be defined. Mixing bridge and macvlan devices is allowed.

              Example:
              $ sudo brctl addbr br0
              $ sudo ifconfig br0 10.10.20.1/24
              $ sudo brctl addbr br1
              $ sudo ifconfig br1 10.10.30.1/24
              $ firejail --net=br0 --net=br1

       --net=ethernet_interface
              Enable  a  new network namespace and connect it to this ethernet
              interface using the standard Linux macvlan driver. Unless speci‐
              fied  with  option  --ip  and  --defaultgw,  an IP address and a
              default gateway will be assigned automatically to  the  sandbox.
              The  IP  address  is  verified  using ARP before assignment. The
              address configured as default gateway is the default gateway  of
              the host. Up to four --net devices can be defined. Mixing bridge
              and macvlan devices is allowed.  Note: wlan devices are not sup‐
              ported for this option.

              Example:
              $ firejail --net=eth0 --ip=192.168.1.80 --dns=8.8.8.8 firefox

       --net=none
              Enable  a new, unconnected network namespace. The only interface
              available in the new namespace is a new loopback interface (lo).
              Use  this  option  to deny network access to programs that don't
              really need network access.

              Example:
              $ firejail --net=none vlc

              Note: --net=none can crash the application  on  some  platforms.
              In these cases, it can be replaced with --protocol=unix.

       --netns=name
              Run the program in a named, persistent network namespace.  These
              can be created and configured using "ip netns".

       --netfilter
              Enable a default firewall if a new network namespace is  created
              inside  the  sandbox.   This  option has no effect for sandboxes
              using the system network namespace.

              The default firewall is optimized for regular  desktop  applica‐
              tions. No incoming connections are accepted:

              *filter
              :INPUT DROP [0:0]
              :FORWARD DROP [0:0]
              :OUTPUT ACCEPT [0:0]
              -A INPUT -i lo -j ACCEPT
              -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
              # allow ping
              -A INPUT -p icmp --icmp-type destination-unreachable -j ACCEPT
              -A INPUT -p icmp --icmp-type time-exceeded -j ACCEPT
              -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
              # drop STUN (WebRTC) requests
              -A OUTPUT -p udp --dport 3478 -j DROP
              -A OUTPUT -p udp --dport 3479 -j DROP
              -A OUTPUT -p tcp --dport 3478 -j DROP
              -A OUTPUT -p tcp --dport 3479 -j DROP
              COMMIT

              Example:
              $ firejail --net=eth0 --netfilter firefox

       --netfilter=filename
              Enable  the  firewall  specified  by  filename  if a new network
              namespace is created inside the sandbox.   This  option  has  no
              effect for sandboxes using the system network namespace.

              Please use the regular iptables-save/iptables-restore format for
              the  filter  file.  The  following  examples  are  available  in
              /etc/firejail directory:

              webserver.net is a webserver firewall that allows access only to
              TCP ports 80 and 443.  Example:

              $ firejail --netfilter=/etc/firejail/webserver.net --net=eth0 \
              /etc/init.d/apache2 start

              nolocal.net is a desktop client firewall that disable access  to
              local network. Example:

              $ firejail --netfilter=/etc/firejail/nolocal.net \
              --net=eth0 firefox

       --netfilter=filename,arg1,arg2,arg3 ...
              This  is  the  template  version of the previous command. $ARG1,
              $ARG2, $ARG3 ... in the firewall script are replaced with  arg1,
              arg2,  arg3  ...  passed on the command line. Up to 16 arguments
              are supported.  Example:

              $ firejail --net=eth0 --ip=192.168.1.105 \
              --netfilter=/etc/firejail/tcpserver.net,5001 server-program

       --netfilter.print=name|pid
              Print the firewall installed in the sandbox specified by name or
              PID. Example:

              $ firejail --name=browser --net=eth0 --netfilter firefox &
              $ firejail --netfilter.print=browser

       --netfilter6=filename
              Enable  the IPv6 firewall specified by filename if a new network
              namespace is created inside the sandbox.   This  option  has  no
              effect for sandboxes using the system network namespace.  Please
              use the regular iptables-save/iptables-restore  format  for  the
              filter file.

       --netfilter6.print=name|pid
              Print  the  IPv6  firewall installed in the sandbox specified by
              name or PID. Example:

              $ firejail --name=browser --net=eth0 --netfilter firefox &
              $ firejail --netfilter6.print=browser

       --netstats
              Monitor network namespace statistics, see MONITORING section for
              more details.

              Example:

              $ firejail --netstats
              PID  User    RX(KB/s) TX(KB/s) Command
              1294 netblue 53.355   1.473    firejail --net=eth0 firefox
              7383 netblue 9.045    0.112    firejail --net=eth0 transmission

       --nice=value
              Set  nice  value  for  all processes running inside the sandbox.
              Only root may specify a negative value.

              Example:
              $ firejail --nice=2 firefox

       --no3d Disable 3D hardware acceleration.

              Example:
              $ firejail --no3d firefox

       --noblacklist=dirname_or_filename
              Disable blacklist for this directory or file.

              Example:
              $ firejail
              $ nc dict.org 2628
              bash: /bin/nc: Permission denied
              $ exit

              $ firejail --noblacklist=/bin/nc
              $ nc dict.org 2628
              220 pan.alephnull.com dictd 1.12.1/rf on Linux 3.14-1-amd64

       --nodvd
              Disable DVD and audio CD devices.

              Example:
              $ firejail --nodvd

       --noexec=dirname_or_filename
              Remount directory or file noexec, nodev and nosuid.  File  glob‐
              bing is supported, see FILE GLOBBING section for more details.

              Example:
              $ firejail --noexec=/tmp

              /etc  and  /var are noexec by default if the sandbox was started
              as a regular user. If there are more than one mount operation on
              the  path  of the file or directory, noexec should be applied to
              the last one. Always check if the change took effect inside  the
              sandbox.

       --nogroups
              Disable supplementary groups. Without this option, supplementary
              groups are enabled for the user starting the sandbox.  For  root
              user supplementary groups are always disabled.

              Note:  By  default  all regular user groups are removed with the
              exception of  the  current  user.  This  can  be  changed  using
              --allusers command option.

              Example:
              $ id
              uid=1000(netblue)       gid=1000(netblue)       groups=1000(net‐
              blue),24(cdrom),25(floppy),27(sudo),29(audio)
              $ firejail --nogroups
              Parent pid 8704, child pid 8705
              Child process initialized
              $ id
              uid=1000(netblue) gid=1000(netblue) groups=1000(netblue)
              $

       --noprofile
              Do not use a security profile.

              Example:
              $ firejail
              Reading profile /etc/firejail/default.profile
              Parent pid 8553, child pid 8554
              Child process initialized
              [...]

              $ firejail --noprofile
              Parent pid 8553, child pid 8554
              Child process initialized
              [...]

       --noroot
              Install a user namespace with a single user - the current  user.
              root  user  does  not  exist  in  the new namespace. This option
              requires a Linux kernel version 3.8 or newer. The option is  not
              supported  for  --chroot  and  --overlay  configurations, or for
              sandboxes started as root.

              Example:
              $ firejail --noroot
              Parent pid 8553, child pid 8554
              Child process initialized
              $ ping google.com
              ping: icmp open socket: Operation not permitted
              $

       --nonewprivs
              Sets the NO_NEW_PRIVS prctl.  This ensures that child  processes
              cannot  acquire  new privileges using execve(2);  in particular,
              this means that calling a suid binary (or one with file capabil‐
              ities)  does not result in an increase of privilege. This option
              is enabled by default if seccomp filter is activated.

       --nosound
              Disable sound system.

              Example:
              $ firejail --nosound firefox

       --notv Disable DVB (Digital Video Broadcasting) TV devices.

              Example:
              $ firejail --notv vlc

       --novideo
              Disable video devices.

       --nowhitelist=dirname_or_filename
              Disable whitelist for this directory or file.

       --output=logfile
              stdout logging and log rotation. Copy  stdout  to  logfile,  and
              keep  the  size of the file under 500KB using log rotation. Five
              files with prefixes .1 to .5 are used in rotation.

              Example:
              $ firejail --output=sandboxlog /bin/bash
              [...]
              $ ls -l sandboxlog*
              -rw-r--r-- 1 netblue netblue 333890 Jun  2 07:48 sandboxlog
              -rw-r--r-- 1 netblue netblue 511488 Jun  2 07:48 sandboxlog.1
              -rw-r--r-- 1 netblue netblue 511488 Jun  2 07:48 sandboxlog.2
              -rw-r--r-- 1 netblue netblue 511488 Jun  2 07:48 sandboxlog.3
              -rw-r--r-- 1 netblue netblue 511488 Jun  2 07:48 sandboxlog.4
              -rw-r--r-- 1 netblue netblue 511488 Jun  2 07:48 sandboxlog.5

       --output-stderr=logfile
              Similar to --output, but stderr is also stored.

       --overlay
              Mount a filesystem overlay on top  of  the  current  filesystem.
              Unlike  the regular filesystem container, the system directories
              are mounted read-write. All filesystem modifications go into the
              overlay.   The overlay is stored in $HOME/.firejail/ direc‐
              tory.

              OverlayFS support is required in Linux kernel for this option to
              work.   OverlayFS was officially introduced in Linux kernel ver‐
              sion 3.18.  This option is not available on Grsecurity systems.

              Example:
              $ firejail --overlay firefox

       --overlay-named=name
              Mount a filesystem overlay on top  of  the  current  filesystem.
              Unlike  the regular filesystem container, the system directories
              are mounted read-write. All filesystem modifications go into the
              overlay.  The overlay is stored in $HOME/.firejail/ direc‐
              tory. The created overlay can be reused  between  multiple  ses‐
              sions.

              OverlayFS support is required in Linux kernel for this option to
              work.  OverlayFS was officially introduced in Linux kernel  ver‐
              sion 3.18.  This option is not available on Grsecurity systems.

              Example:
              $ firejail --overlay-named=jail1 firefox

       --overlay-tmpfs
              Mount a filesystem overlay on top of the current filesystem. All
              filesystem modifications  are  discarded  when  the  sandbox  is
              closed.

              OverlayFS support is required in Linux kernel for this option to
              work.  OverlayFS was officially introduced in Linux kernel  ver‐
              sion 3.18.  This option is not available on Grsecurity systems.

              Example:
              $ firejail --overlay-tmpfs firefox

       --overlay-clean
              Clean all overlays stored in $HOME/.firejail directory.

              Example:
              $ firejail --overlay-clean

       --private
              Mount new /root and /home/user directories in temporary filesys‐
              tems. All  modifications  are  discarded  when  the  sandbox  is
              closed.

              Example:
              $ firejail --private firefox

       --private=directory
              Use directory as user home.

              Example:
              $ firejail --private=/home/netblue/firefox-home firefox

       --private-home=file,directory
              Build  a  new  user home in a temporary filesystem, and copy the
              files and directories in the list in the new home. All modifica‐
              tions are discarded when the sandbox is closed.

              Example:
              $ firejail --private-home=.mozilla firefox

       --private-bin=file,file
              Build  a  new  /bin in a temporary filesystem, and copy the pro‐
              grams in the list.  If no listed file is found,  /bin  directory
              will  be  empty.   The  same directory is also bind-mounted over
              /sbin, /usr/bin, /usr/sbin and  /usr/local/bin.   All  modifica‐
              tions are discarded when the sandbox is closed. File globbing is
              supported, see FILE GLOBBING section for more details.

              Example:
              $ firejail --private-bin=bash,sed,ls,cat
              Parent pid 20841, child pid 20842
              Child process initialized
              $ ls /bin
              bash  cat  ls  sed

       --private-lib=file,directory
              This feature is currently under heavy  development.  Only  amd64
              platforms  are supported at this moment.  The idea is to build a
              new /lib in a temporary filesystem, with only the library  files
              necessary to run the application.  It could be as simple as:

              $ firejail --private-lib galculator

              but it gets complicated really fast:

              $    firejail   --private-lib=x86_64-linux-gnu/xed,x86_64-linux-
              gnu/gdk-pixbuf-2.0,libenchant.so.1,librsvg-2.so.2 xed

              The feature is integrated with --private-bin:

              $ firejail --private-lib --private-bin=bash,ls,ps
              $ ls /lib
              ld-linux-x86-64.so.2  libgpg-error.so.0  libprocps.so.6  libsys‐
              temd.so.0
              libc.so.6 liblz4.so.1 libpthread.so.0 libtinfo.so.5
              libdl.so.2 liblzma.so.5 librt.so.1 x86_64-linux-gnu
              libgcrypt.so.20 libpcre.so.3 libselinux.so.1
              $ ps
               PID TTY          TIME CMD
                  1 pts/0    00:00:00 firejail
                 45 pts/0    00:00:00 bash
                 48 pts/0    00:00:00 ps
              $

       --private-dev
              Create  a  new /dev directory. Only disc, dri, null, full, zero,
              tty, pts, ptmx, random, snd, urandom, video, log and shm devices
              are available.

              Example:
              $ firejail --private-dev
              Parent pid 9887, child pid 9888
              Child process initialized
              $ ls /dev
              cdrom  cdrw  dri  dvd  dvdrw  full  log  null  ptmx  pts  random
              shm  snd  sr0  tty  urandom  zero
              $

       --private-etc=file,directory
              Build a new /etc in a temporary filesystem, and copy  the  files
              and  directories  in the list.  If no listed file is found, /etc
              directory will be empty.  All modifications are  discarded  when
              the sandbox is closed.

              Example:
              $ firejail --private-etc=group,hostname,localtime, \
              nsswitch.conf,passwd,resolv.conf

       --private-opt=file,directory
              Build  a  new /opt in a temporary filesystem, and copy the files
              and directories in the list.  If no listed file is  found,  /opt
              directory  will  be empty.  All modifications are discarded when
              the sandbox is closed.

              Example:
              $ firejail --private-opt=firefox /opt/firefox/firefox

       --private-srv=file,directory
              Build a new /srv in a temporary filesystem, and copy  the  files
              and  directories  in the list.  If no listed file is found, /srv
              directory will be empty.  All modifications are  discarded  when
              the sandbox is closed.

              Example:
              # firejail --private-srv=www /etc/init.d/apache2 start

       --private-tmp
              Mount  an  empty  temporary  filesystem on top of /tmp directory
              whitelisting X11 and PulseAudio sockets.

              Example:
              $ firejail --private-tmp
              $ ls -al /tmp
              drwxrwxrwt  4 nobody nogroup   80 Apr 30 11:46 .
              drwxr-xr-x 30 nobody nogroup 4096 Apr 26 22:18 ..
              drwx------  2  nobody  nogroup  4096  Apr  30  10:52  pulse-PKd‐
              htXMmr18n
              drwxrwxrwt  2 nobody nogroup 4096 Apr 30 10:52 .X11-unix

       --profile=filename
              Load  a  custom security profile from filename. For filename use
              an absolute path or a path relative to the  current  path.   For
              more information, see SECURITY PROFILES section below.

              Example:
              $ firejail --profile=myprofile

       --profile.print=name|pid
              Print the name of the profile file for the sandbox identified by
              name or or PID.

              Example:
              $ firejail --profile.print=browser
              /etc/firejail/firefox.profile

       --protocol=protocol,protocol,protocol
              Enable protocol filter. The  filter  is  based  on  seccomp  and
              checks  the  first  argument  to socket system call.  Recognized
              values: unix, inet, inet6, netlink and packet.  This  option  is
              not supported for i386 architecture.

              Example:
              $ firejail --protocol=unix,inet,inet6 firefox

       --protocol.print=name|pid
              Print  the protocol filter for the sandbox identified by name or
              PID.

              Example:
              $ firejail --name=mybrowser firefox &
              $ firejail --protocol.print=mybrowser
              unix,inet,inet6,netlink

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --protocol.print=3272
              unix,inet,inet6,netlink

       --put=name|pid src-filename dest-filename
              Put a file in sandbox container, see FILE TRANSFER  section  for
              more details.

       --quiet
              Turn off Firejail's output.

       --read-only=dirname_or_filename
              Set directory or file read-only. File globbing is supported, see
              FILE GLOBBING section for more details.

              Example:
              $ firejail --read-only=~/.mozilla firefox

              A short note about mixing --whitelist and  --read-only  options.
              Whitelisted  directories should be made read-only independently.
              Making a parent directory read-only, will not make the whitelist
              read-only. Example:

              $ firejail --whitelist=~/work --read-only=~ --read-only=~/work

       --read-write=dirname_or_filename
              Set  directory  or  file  read-write.  Only files or directories
              belonging to the current user are allowed  for  this  operation.
              File  globbing  is supported, see FILE GLOBBING section for more
              details.  Example:

              $ mkdir ~/test
              $ touch ~/test/a
              $ firejail --read-only=~/test --read-write=~/test/a

       --rlimit-as=number
              Set the maximum size of the process's  virtual  memory  (address
              space) in bytes.

       --rlimit-cpu=number
              Set  the  maximum  limit, in seconds, for the amount of CPU time
              each sandboxed process  can consume. When the limit is  reached,
              the processes are killed.

              The  CPU  limit  is  a  limit on CPU seconds rather than elapsed
              time. CPU seconds is basically how many seconds the CPU has been
              in  use  and does not necessarily directly relate to the elapsed
              time. Linux kernel keeps track of CPU seconds for  each  process
              independently.

       --rlimit-fsize=number
              Set the maximum file size that can be created by a process.

       --rlimit-nofile=number
              Set the maximum number of files that can be opened by a process.

       --rlimit-nproc=number
              Set  the maximum number of processes that can be created for the
              real user ID of the calling process.

       --rlimit-sigpending=number
              Set the maximum number of pending signals for a process.

       --rmenv=name
              Remove environment variable in the new sandbox.

              Example:
              $ firejail --rmenv=DBUS_SESSION_BUS_ADDRESS

       --scan ARP-scan all the networks from inside a network namespace.  This
              makes  it  possible to detect macvlan kernel device drivers run‐
              ning on the current host.

              Example:
              $ firejail --net=eth0 --scan

       --seccomp
              Enable seccomp filter and blacklist the syscalls in the  default
              list (@default). The default list is as follows: mount, umount2,
              ptrace,    kexec_load,    kexec_file_load,    name_to_handle_at,
              open_by_handle_at,   create_module,  init_module,  finit_module,
              delete_module, iopl, ioperm, ioprio_set, swapon,  swapoff,  sys‐
              log,  process_vm_readv,  process_vm_writev,  sysfs,_sysctl, adj‐
              timex,  clock_adjtime,  lookup_dcookie,  perf_event_open,   fan‐
              otify_init,  kcmp,  add_key,  request_key, keyctl, uselib, acct,
              modify_ldt,  pivot_root,  io_setup,  io_destroy,   io_getevents,
              io_submit,  io_cancel,  remap_file_pages,  mbind, set_mempolicy,
              migrate_pages, move_pages, vmsplice,  chroot,  tuxcall,  reboot,
              mfsservctl,  get_kernel_syms,  bpf,  clock_settime, personality,
              process_vm_writev, query_module,  settimeofday,  stime,  umount,
              userfaultfd,  ustat, vm86, vm86old, afs_syscall, bdflush, break,
              ftime,  getpmsg,  gtty,  lock,  mpx,  pciconfig_iobase,  pcicon‐
              fig_read,   pciconfig_write,   prof,   profil,   putpmsg,  rtas,
              s390_runtime_instr, s390_mmio_read,  s390_mmio_write,  security,
              setdomainname,   sethostname,  sgetmask,  ssetmask,  stty,  sub‐
              page_prot, switch_endian, ulimit, vhangup and vserver.

              To help creating useful seccomp filters more easily, the follow‐
              ing  system  call  groups  are  defined: @clock, @cpu-emulation,
              @debug, @default, @default-nodebuggers, @default-keep,  @module,
              @obsolete,  @privileged, @raw-io, @reboot, @resources and @swap.
              In addtion, a system call can be specified by its number instead
              of  name  with  prefix  $, so for example $165 would be equal to
              mount on i386.

              System architecture is strictly  imposed  only  if  flag  --sec‐
              comp.block-secondary  is used. The filter is applied at run time
              only if the correct architecture was detected. For the  case  of
              I386 and AMD64 both 32-bit and 64-bit filters are installed.

              Firejail  will  print seccomp violations to the audit log if the
              kernel was compiled with audit support (CONFIG_AUDIT flag).

              Example:
              $ firejail --seccomp

       --seccomp=syscall,@group
              Enable seccomp filter, blacklist the default list (@default) and
              the syscalls or syscall groups specified by the command.

              Example:
              $ firejail --seccomp=utime,utimensat,utimes firefox
              $ firejail --seccomp=@clock,mkdir,unlinkat transmission-gtk

              Instead  of dropping the syscall, a specific error number can be
              returned using syscall:errorno syntax.

              Example: $ firejail --seccomp=unlinkat:ENOENT,utimensat,utimes
              Parent pid 10662, child pid 10663
              Child process initialized
              $ touch testfile
              $ rm testfile
              rm: cannot remove `testfile': Operation not permitted

              If the blocked system calls would also block Firejail from oper‐
              ating, they are handled by adding a preloaded library which per‐
              forms seccomp system calls later.

              Example:
              $ firejail --noprofile --shell=none --seccomp=execve bash
              Parent pid 32751, child pid 32752
              Post-exec seccomp protector enabled
              list in: execve,  check  list:  @default-keep  prelist:  (null),
              postlist: execve
              Child process initialized in 46.44 ms
              $ ls
              Bad system call

       --seccomp.block_secondary
              Enable  seccomp  filter  and filter system call architectures so
              that only the native architecture is allowed.  For  example,  on
              amd64, i386 and x32 system calls are blocked as well as changing
              the execution domain with personality(2) system call.

       --seccomp.drop=syscall,@group
              Enable seccomp filter, and blacklist the syscalls or the syscall
              groups specified by the command.

              Example:
              $ firejail --seccomp.drop=utime,utimensat,utimes,@clock

              Instead  of dropping the syscall, a specific error number can be
              returned using syscall:errorno syntax.

              Example:
              $ firejail --seccomp.drop=unlinkat:ENOENT,utimensat,utimes
              Parent pid 10662, child pid 10663
              Child process initialized
              $ touch testfile
              $ rm testfile
              rm: cannot remove `testfile': Operation not permitted

       --seccomp.keep=syscall,syscall,syscall
              Enable seccomp filter, and whitelist the syscalls  specified  by
              the   command.  The  system  calls  needed  by  Firejail  (group
              @default-keep: prctl,  execve)  are  handled  with  the  preload
              library.

              Example:
              $  firejail --shell=none --seccomp.keep=poll,select,[...] trans‐
              mission-gtk

       --seccomp.print=name|PID
              Print the seccomp filter for the sandbox identified by  name  or
              PID.

              Example:
              $ firejail --name=browser firefox &
              $ firejail --seccomp.print=browser
              SECCOMP Filter:
                VALIDATE_ARCHITECTURE
                EXAMINE_SYSCALL
                BLACKLIST 165 mount
                BLACKLIST 166 umount2
                BLACKLIST 101 ptrace
                BLACKLIST 246 kexec_load
                BLACKLIST 304 open_by_handle_at
                BLACKLIST 175 init_module
                BLACKLIST 176 delete_module
                BLACKLIST 172 iopl
                BLACKLIST 173 ioperm
                BLACKLIST 167 swapon
                BLACKLIST 168 swapoff
                BLACKLIST 103 syslog
                BLACKLIST 310 process_vm_readv
                BLACKLIST 311 process_vm_writev
                BLACKLIST 133 mknod
                BLACKLIST 139 sysfs
                BLACKLIST 156 _sysctl
                BLACKLIST 159 adjtimex
                BLACKLIST 305 clock_adjtime
                BLACKLIST 212 lookup_dcookie
                BLACKLIST 298 perf_event_open
                BLACKLIST 300 fanotify_init
                RETURN_ALLOW
              $

       --shell=none
              Run the program directly, without a user shell.

              Example:
              $ firejail --shell=none script.sh

       --shell=program
              Set  default  user  shell. Use this shell to run the application
              using -c shell option.  For example "firejail  --shell=/bin/dash
              firefox"  will  start Mozilla Firefox as "/bin/dash -c firefox".
              By default Bash shell (/bin/bash) is used. Options such as --zsh
              and --csh can also set the default shell.

              Example: $firejail --shell=/bin/dash script.sh

       --shutdown=name|PID
              Shutdown the sandbox identified by name or PID.

              Example:
              $ firejail --name=mygame --caps.drop=all warzone2100 &
              $ firejail --shutdown=mygame

              Example:
              $ firejail --list
              3272:netblue:firejail --private firefox
              $ firejail --shutdown=3272

       --timeout=hh:mm:ss
              Kill  the  sandbox automatically after the time has elapsed. The
              time is specified in hours/minutes/seconds format.

              $ firejail --timeout=01:30:00 firefox

       --tmpfs=dirname
              Mount a tmpfs filesystem on directory dirname.  This  option  is
              available  only when running the sandbox as root.  File globbing
              is supported, see FILE GLOBBING section for more details.

              Example:
              # firejail --tmpfs=/var

       --top  Monitor the most CPU-intensive sandboxes, see MONITORING section
              for more details.

              Example:
              $ firejail --top

       --trace
              Trace open, access and connect system calls.

              Example:
              $ firejail --trace wget -q www.debian.org
              Reading profile /etc/firejail/wget.profile
              3:wget:fopen64 /etc/wgetrc:0x5c8e8ce6c0
              3:wget:fopen /etc/hosts:0x5c8e8cfb70
              3:wget:socket AF_INET SOCK_DGRAM IPPROTO_IP:3
              3:wget:connect 3 8.8.8.8 port 53:0
              3:wget:socket AF_INET SOCK_STREAM IPPROTO_IP:3
              3:wget:connect 3 130.89.148.14 port 80:0
              3:wget:fopen64 index.html:0x5c8e8d1a60

              parent is shutting down, bye...

       --tracelog
              This  option enables auditing blacklisted files and directories.
              A message is sent to syslog in case the file or the directory is
              accessed.

              Example:
              $ firejail --tracelog firefox

              Sample messages:
              $ sudo tail -f /var/log/syslog
              [...]
              Dec  3 11:43:25 debian firejail[70]: blacklist violation - sand‐
              box 26370, exe firefox, syscall open64, path /etc/shadow
              Dec  3 11:46:17 debian firejail[70]: blacklist violation - sand‐
              box 26370, exe firefox, syscall opendir, path /boot
              [...]

       --tree Print  a tree of all sandboxed processes, see MONITORING section
              for more details.

              Example:
              $ firejail --tree
              11903:netblue:firejail iceweasel
                11904:netblue:iceweasel
                  11957:netblue:/usr/lib/iceweasel/plugin-container
              11969:netblue:firejail --net=eth0 transmission-gtk
                11970:netblue:transmission-gtk

       --version
              Print program version and exit.

              Example:
              $ firejail --version
              firejail version 0.9.27

       --veth-name=name
              Use this name for the interface  connected  to  the  bridge  for
              --net=bridge_interface commands, instead of the default one.

              Example:
              $ firejail --net=br0 --veth-name=if0

       --whitelist=dirname_or_filename
              Whitelist  directory or file. A temporary file system is mounted
              on the top directory, and the whitelisted files are mount-binded
              inside.  Modifications  to  whitelisted  files  are  persistent,
              everything else is discarded when the sandbox is closed. The top
              directory  could  be  user home, /dev, /media, /mnt, /opt, /srv,
              /var, and /tmp.

              Symbolic link handling: with the exception of  user  home,  both
              the  link and the real file should be in the same top directory.
              For user home, both the link and the real file should  be  owned
              by the user.

              Example:
              $ firejail --noprofile --whitelist=~/.mozilla
              $ firejail --whitelist=/tmp/.X11-unix --whitelist=/dev/null
              $ firejail "--whitelist=/home/username/My Virtual Machines"

       --writable-etc
              Mount /etc directory read-write.

              Example:
              $ sudo firejail --writable-etc

       --writable-run-user
              Disable  the  default blacklisting of /run/user/$UID/systemd and
              /run/user/$UID/gnupg.

              Example:
              $ sudo firejail --writable-run-user

       --writable-var
              Mount /var directory read-write.

              Example:
              $ sudo firejail --writable-var

       --writable-var-log
              Use the real /var/log directory, not  a  clone.  By  default,  a
              tmpfs  is  mounted  on top of /var/log directory, and a skeleton
              filesystem is created based on the original /var/log.

              Example:
              $ sudo firejail --writable-var-log

       --x11  Sandbox the application using Xpra, Xephyr, Xvfb or  Xorg  secu‐
              rity  extension.   The sandbox will prevents screenshot and key‐
              logger applications started inside the  sandbox  from  accessing
              clients  running  outside  the sandbox.  Firejail will try first
              Xpra, and if Xpra is not installed on the system, it will try to
              find  Xephyr.   If  all  fails, Firejail will not attempt to use
              Xvfb or X11 security extension.

              Xpra, Xephyr and Xvfb modes require a network  namespace  to  be
              instantiated  in  order  to disable X11 abstract Unix socket. If
              this is not possible, the user can disable the  abstract  socket
              by  adding  "-nolisten  local"  on  Xorg  command line at system
              level.

              Example:
              $ firejail --x11 --net=eth0 firefox

       --x11=none
              Blacklist /tmp/.X11-unix directory, ${HOME}/.Xauthority and  the
              file  specified  in  ${XAUTHORITY} environment variable.  Remove
              DISPLAY and XAUTHORITY environment variables.  Stop  with  error
              message if X11 abstract socket will be accessible in jail.

       --x11=xephyr
              Start Xephyr and attach the sandbox to this server.  Xephyr is a
              display server implementing the X11 display server protocol.   A
              network  namespace  needs  to  be  instantiated in order to deny
              access to X11 abstract Unix domain socket.

              Xephyr runs in a window just like any other X11 application. The
              default  window  size  is  800x600.   This  can  be  modified in
              /etc/firejail/firejail.config file.

              The recommended way to use this feature is to run a window  man‐
              ager inside the sandbox.  A security profile for OpenBox is pro‐
              vided.

              Xephyr is developed by Xorg project. On Debian platforms  it  is
              installed  with the command sudo apt-get install xserver-xephyr.
              This feature is not available when running as root.

              Example:
              $ firejail --x11=xephyr --net=eth0 openbox

       --x11=xorg
              Sandbox the application using the untrusted mode implemented  by
              X11  security  extension.   The  extension  is available in Xorg
              package and it is installed by default on most  Linux  distribu‐
              tions.  It  provides support for a simple trusted/untrusted con‐
              nection model. Untrusted clients are restricted in certain  ways
              to  prevent  them from reading window contents of other clients,
              stealing input events, etc.

              The untrusted mode has several limitations.  A  lot  of  regular
              programs   assume  they are a trusted X11 clients and will crash
              or lock up when run in  untrusted  mode.  Chromium  browser  and
              xterm are two examples.  Firefox and transmission-gtk seem to be
              working fine.  A network namespace  is  not  required  for  this
              option.

              Example:
              $ firejail --x11=xorg firefox

       --x11=xpra
              Start  Xpra  (https://xpra.org)  and  attach the sandbox to this
              server.  Xpra is a persistent remote display server  and  client
              for  forwarding X11 applications and desktop screens.  A network
              namespace needs to be instantiated in order to  deny  access  to
              X11 abstract Unix domain socket.

              On Debian platforms Xpra is installed with the command sudo apt-
              get install xpra.  This feature is not available when running as
              root.

              Example:
              $ firejail --x11=xpra --net=eth0 firefox

       --x11=xvfb
              Start  Xvfb  X11  server  and attach the sandbox to this server.
              Xvfb, short for X virtual framebuffer,  performs  all  graphical
              operations  in memory without showing any screen output. Xvfb is
              mainly used for remote access and software testing  on  headless
              servers.

              On Debian platforms Xvfb is installed with the command sudo apt-
              get install xvfb.  This feature is not available when running as
              root.

              Example: remote VNC access

              On  the  server we start a sandbox using Xvfb and openbox window
              manager. The default size of Xvfb screen is 800x600 - it can  be
              changed  in  /etc/firejail/firejail.config  (xvfb-screen).  Some
              sort of networking (--net) is required in order to  isolate  the
              abstract sockets used by other X servers.

              $ firejail --net=none --x11=xvfb openbox

              *** Attaching to Xvfb display 792 ***

              Reading profile /etc/firejail/openbox.profile
              Reading profile /etc/firejail/disable-common.inc
              Reading profile /etc/firejail/disable-common.local
              Parent pid 5400, child pid 5401

              On  the  server  we also start a VNC server and attach it to the
              display handled by our Xvfb server (792).

              $ x11vnc -display :792

              On the client machine we start a VNC viewer and use it  to  con‐
              nect to our server:

              $ vncviewer

       --xephyr-screen=WIDTHxHEIGHT
              Set screen size for --x11=xephyr. The setting will overwrite the
              default set in  /etc/firejail/firejail.config  for  the  current
              sandbox.  Run  xrandr  to get a list of supported resolutions on
              your computer.

              Example:
              $ firejail --net=eth0 --x11=xephyr --xephyr-screen=640x480 fire‐
              fox

       --zsh  Use /usr/bin/zsh as default user shell.

              Example:
              $ firejail --zsh

DESKTOP INTEGRATION
       A  symbolic link to /usr/bin/firejail under the name of a program, will
       start the program in Firejail sandbox.  The  symbolic  link  should  be
       placed  in  the  first $PATH position. On most systems, a good place is
       /usr/local/bin directory. Example:

              Make a firefox symlink to /usr/bin/firejail:

              $ ln -s /usr/bin/firejail /usr/local/bin/firefox

              Verify $PATH

              $ which -a firefox
              /usr/local/bin/firefox
              /usr/bin/firefox

              Starting firefox in this moment, automatically invokes “firejail
              firefox”.

       This  works  for  clicking on desktop environment icons, menus etc. Use
       "firejail --tree" to verify the program is sandboxed.

              $ firejail --tree
              1189:netblue:firejail firefox
                1190:netblue:firejail firefox
                  1220:netblue:/bin/sh -c "/usr/lib/firefox/firefox"
                    1221:netblue:/usr/lib/firefox/firefox

       We provide a tool that automates all this integration, please see man 1
       firecfg for more details.

FILE GLOBBING
       Globbing is the operation that expands a wildcard pattern into the list
       of pathnames matching the pattern. Matching is defined by:

              - '?' matches any character
              - '*' matches any string
              - '[' denotes a range of characters

       The gobing feature is implemented using glibc glob  command.  For  more
       information on the wildcard syntax see man 7 glob.

       The  following  command line options are supported: --blacklist, --pri‐
       vate-bin, --noexec, --read-only, --read-write, and --tmpfs.

       Examples:

              $ firejail --private-bin=sh,bash,python*
              $ firejail --blacklist=~/dir[1234]
              $ firejail --read-only=~/dir[1-4]

APPARMOR
       AppArmor support is disabled by default at compile time. Use  --enable-
       apparmor configuration option to enable it:

              $ ./configure --prefix=/usr --enable-apparmor

       During  software  install,  a  generic AppArmor profile file, firejail-
       default, is placed in /etc/apparmor.d directory. The profile  needs  to
       be loaded into the kernel by running the following command as root:

              # aa-enforce firejail-default

       The  installed  profile  tries to replicate some advanced security fea‐
       tures inspired by kernel-based Grsecurity:

              - Prevent information leakage in /proc and /sys directories. The
              resulting  filesystem is barely enough for running commands such
              as "top" and "ps aux".

              - Allow running programs only from well-known system paths, such
              as  /bin, /sbin, /usr/bin etc. Running programs and scripts from
              user home or other directories  writable  by  the  user  is  not
              allowed.

              -  Allow access to files only in the following standard directo‐
              ries: /bin, /dev, /etc, /home, /lib*, /media, /mnt, /opt, /proc,
              /root, /run, /sbin, /srv, /sys, /tmp, /usr, and /var

              -  Disable  D-Bus. D-Bus has long been a huge security hole, and
              most programs don't use it anyway.  You should have no  problems
              running  Chromium  or Firefox. This feature is available only on
              Ubuntu kernels.

       To enable AppArmor confinement on top of your current Firejail security
       features,  pass  --apparmor flag to Firejail command line. You can also
       include apparmor command in a Firejail profile file. Example:

              $ firejail --apparmor firefox

FILE TRANSFER
       These features allow the user to inspect the filesystem container of an
       existing  sandbox  and  transfer  files  from the container to the host
       filesystem.

       --get=name|pid filename
              Retrieve the container file and store it on the host in the cur‐
              rent  working  directory.  The container is specified by name or
              PID.

       --ls=name|pid dir_or_filename
              List container files. The container is specified by name or PID.

       --put=name|pid src-filename dest-filename
              Put src-filename in sandbox container.  The container is  speci‐
              fied by name or PID.

       Examples:

              $ firejail --name=mybrowser --private firefox

              $ firejail --ls=mybrowser ~/Downloads
              drwxr-xr-x netblue  netblue         4096 .
              drwxr-xr-x netblue  netblue         4096 ..
              -rw-r--r-- netblue  netblue         7847 x11-x305.png
              -rw-r--r-- netblue  netblue         6800 x11-x642.png
              -rw-r--r-- netblue  netblue        34139 xpra-clipboard.png

              $ firejail --get=mybrowser ~/Downloads/xpra-clipboard.png

              $  firejail --put=mybrowser xpra-clipboard.png ~/Downloads/xpra-
              clipboard.png

TRAFFIC SHAPING
       Network bandwidth is an expensive resource shared among  all  sandboxes
       running  on a system.  Traffic shaping allows the user to increase net‐
       work performance by controlling the amount of data that flows into  and
       out of the sandboxes.

       Firejail  implements  a simple rate-limiting shaper based on Linux com‐
       mand tc.  The shaper works at sandbox level, and can be used  only  for
       sandboxes configured with new network namespaces.

       Set rate-limits:

            $ firejail --bandwidth=name|pid set network download upload

       Clear rate-limits:

            $ firejail --bandwidth=name|pid clear network

       Status:

            $ firejail --bandwidth=name|pid status

       where:
            name - sandbox name
            pid - sandbox pid
            network - network interface as used by --net option
            download - download speed in KB/s (kilobyte per second)
            upload - upload speed in KB/s (kilobyte per second)

       Example:
            $ firejail --name=mybrowser --net=eth0 firefox &
            $ firejail --bandwidth=mybrowser set eth0 80 20
            $ firejail --bandwidth=mybrowser status
            $ firejail --bandwidth=mybrowser clear eth0

AUDIT
       Audit  feature  allows the user to point out gaps in security profiles.
       The implementation replaces the program to be  sandboxed  with  a  test
       program. By default, we use faudit program distributed with Firejail. A
       custom test program can also be supplied by the user. Examples:

       Running the default audit program:
            $ firejail --audit transmission-gtk

       Running a custom audit program:
            $ firejail --audit=~/sandbox-test transmission-gtk

       In the examples above, the sandbox configures transmission-gtk  profile
       and  starts  the test program. The real program, transmission-gtk, will
       not be started.

       Limitations: audit feature is not implemented for --x11 commands.

MONITORING
       Option --list prints a list of  all  sandboxes.  The  format  for  each
       process entry is as follows:

            PID:USER:Command

       Option  --tree prints the tree of processes running in the sandbox. The
       format for each process entry is as follows:

            PID:USER:Command

       Option --top is similar to the UNIX top  command,  however  it  applies
       only to sandboxes.

       Option  --netstats  prints  network  statistics  for  active  sandboxes
       installing new network namespaces.

       Listed below are the available fields (columns) in  alphabetical  order
       for --top and --netstat options:

       Command
              Command used to start the sandbox.

       CPU%   CPU  usage,  the sandbox share of the elapsed CPU time since the
              last screen update

       PID    Unique process ID for the task controlling the sandbox.

       Prcs   Number of processes running in sandbox, including  the  control‐
              ling process.

       RES    Resident Memory Size (KiB), sandbox non-swapped physical memory.
              It is a sum of the RES values for all processes running  in  the
              sandbox.

       RX(KB/s)
              Network receive speed.

       SHR    Shared  Memory  Size (KiB), it reflects memory shared with other
              processes. It is a sum of the SHR values for all processes  run‐
              ning in the sandbox, including the controlling process.

       TX(KB/s)
              Network transmit speed.

       Uptime Sandbox running time in hours:minutes:seconds format.

       User   The owner of the sandbox.

SECURITY PROFILES
       Several command line options can be passed to the program using profile
       files. Firejail chooses the profile file as follows:

       1. If a profile file is provided by the user with --profile option, the
       profile file is loaded.  Example:

              $ firejail --profile=/home/netblue/icecat.profile icecat
              Reading profile /home/netblue/icecat.profile
              [...]

       2.  If  a profile file with the same name as the application is present
       in ~/.config/firejail directory or in  /etc/firejail,  the  profile  is
       loaded.  ~/.config/firejail  takes precedence over /etc/firejail. Exam‐
       ple:

              $ firejail icecat
              Command name #icecat#
              Found icecat profile in /home/netblue/.config/firejail directory
              Reading profile /home/netblue/.config/firejail/icecat.profile
              [...]

       3. Use default.profile file if the sandbox  is  started  by  a  regular
       user,  or  server.profile file if the sandbox is started by root. Fire‐
       jail looks for these files in ~/.config/firejail directory, followed by
       /etc/firejail  directory.   To  disable  default  profile  loading, use
       --noprofile command option. Example:

              $ firejail
              Reading profile /etc/firejail/default.profile
              Parent pid 8553, child pid 8554
              Child process initialized
              [...]

              $ firejail --noprofile
              Parent pid 8553, child pid 8554
              Child process initialized
              [...]

       See man 5 firejail-profile for profile file syntax information.

RESTRICTED SHELL
       To configure a restricted shell, replace /bin/bash with  /usr/bin/fire‐
       jail  in  /etc/passwd  file  for each user that needs to be restricted.
       Alternatively, you can specify /usr/bin/firejail  in adduser command:

       adduser --shell /usr/bin/firejail username

       Additional arguments passed  to  firejail  executable  upon  login  are
       declared in /etc/firejail/login.users file.

EXAMPLES
       firejail
              Sandbox a regular /bin/bash session.

       firejail firefox
              Start Mozilla Firefox.

       firejail --debug firefox
              Debug Firefox sandbox.

       firejail --private firefox
              Start Firefox with a new, empty home directory.

       firejail --net=none vlc
              Start VLC in an unconnected network namespace.

       firejail --net=eth0 firefox
              Start  Firefox  in  a  new  network  namespace. An IP address is
              assigned automatically.

       firejail --net=br0 --ip=10.10.20.5 --net=br1 --net=br2
              Start a /bin/bash session in a new network namespace and connect
              it  to  br0,  br1, and br2 host bridge devices. IP addresses are
              assigned automatically for the interfaces connected to  br1  and
              b2

       firejail --list
              List all sandboxed processes.

LICENSE
       This program is free software; you can redistribute it and/or modify it
       under the terms of the GNU General Public License as published  by  the
       Free  Software Foundation; either version 2 of the License, or (at your
       option) any later version.

       Homepage: https://firejail.wordpress.com

SEE ALSO
       firemon(1), firecfg(1), firejail-profile(5), firejail-login(5)

0.9.52                             Dec 2017                        FIREJAIL(1)

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28 thoughts on “man firejail

  1. Chiraag

    I’m having some difficulty in getting mpd to background properly inside firejail. Using “mpd; sleep inf;” worked before, but it’s now responding with “mpd; sleep inf;: command not found”. What is the “official” way to get this working again? Thanks!

    Like

    Reply
  2. GNUser

    nosound option is breaking profiles.
    I tried it in icedove, piding, firefox, and it breaks all of them. if i try to use a profile that has that option it just gives an error in that line. If I do it like “firejail –nosound firefox” however it works flawlessly. I am using 0.9.38

    Any idea?

    Like

    Reply
      1. GNUser

        I expected it to just prevent that specific application from using sound. It is very “anti-feature” this way, since to prevent one application from being exploited and used to spy, we lose sound in all the other apps. Any workaround?

        Like

  3. procoolheat

    When I installed this for use with Chrome it created a profile somewhere for Chrome so it starts with a loaded Chrome cache and some features enabled on Chrome extensions. So I clear the cache and change the extension settings every time I use it firejail google-chrome is how I start it. I’ve even removed it and reinstalled it but the profile is always the same. This is the latest version also. How do I go about deleting this? It’s acting like its in private mode which I thought was deprecated, Help!

    Like

    Reply
    1. netblue30 Post author

      google-chrome configuration is persistent, and is stored in ~/.config/google-chrome directory. So, if you add a bookmark, next time you start chrome, your bookmark should be there. You can delete the configuration before starting chrome (rm -fr ~/.config/google-chrome). Your Download directory is also persistent.

      If you really want to start every time with a default chrome config, you should run “firejail –private google-chrome”.

      Liked by 1 person

      Reply
  4. Martin

    [quote]
    This works for clicking on desktop environment icons, menus etc. Use
    “firejail –tree” to verify the program is sandboxed.
    [/quote]

    Sadly it’s not working for most applications in Gnome3 in Debian Stretch. Probably because in the *.desktop files there is the full path written.
    Do you know a workaround or you suggest to file a bugreport?

    Like

    Reply
  5. kdemeoz

    Hi. Many thanks for FireJail – it’s an amazing achievement.

    Is there a way for FireJail to sandbox internet-facing programs, whose user-data & config files are NOT stored as conventional in /home, but instead are in separate partition /DATA [albeit symlinked back to /home] ? So far all my tests with combinations of –blacklist & –noblacklist in their launchers [for eg, Thunderbird & Firefox] have failed [& –whitelist can’t be used at all if i understand correctly, given their active directories are not in /home], in that either the programs can’t launch at all [because can’t access their config & data], or they launch but ALL other directories & files in /DATA are exposed to internet. Please?

    Like

    Reply
      1. kdemeoz

        That’s the unfortunate conclusion i’d come to, but given i am still not very skilled with FJ, i felt it best to ask you. Thank you.

        Like

  6. Pingback: Sandbox your applications with Firejail – Own your bits

  7. Matthew

    Trying to use –private-home with Google Chrome default profile. I am trying to preserve the add-ons and plug-ins from my default Chrome profile. I’ve tried many iterations, including [firejail –private-home=~/.google-chrome/Default google-chrome-stable]

    But Chrome just fails to load when I double-click on it in Firetools.

    I have tried using many directory path options, but to no avail. Someone please help.

    Like

    Reply
    1. netblue30 Post author

      Use –private only if you need a browser reseted to factory defaults, without any plugins and addons.

      By default Firejail will allow you to use all Chrome addons and plugins. The only directories exposed in your home are Downloads and Chrome configuration files.

      I would say just start it as “firejail chrome” and you should be ok. We do this for all browsers.

      Like

      Reply
  8. Matthew

    netblue,

    Thx for the info. Much appreciated. As I have been looking into optimizing the security features of Firejail and found out that –seccomp, –overlay and –overlay-tmpfs do not work with Chrome, I have managed to come up with the following (not sure if I’ve missed anything):

    firejail –caps.drop=all –noroot –allow-private-blacklist –blacklist=/Home/ –read-only=~ google-chrome-stable

    Chrome loads no problem and at least I’ve added some additional security features to further tighten the security of the sandbox.

    I’m currently running Fedora v26 and as it relates to all the command-line parameters that add additional measures of security, It has taken a while to figure out what works with Chrome and what doesn’t.

    That being said, and as others have mentioned previously, thank you for all your hard work (and anyone else who worked on Firejail/Firetools).

    Cheers.

    Like

    Reply
  9. Matthew

    Oops. I apologize for not mentioning this in my response above. My main purpose for implementing Firejail / Firetools is solely to improve upon the overall security of internet browsing sessions. I’m not testing software or writing code. This is just to help prevent virus / malware injection. Thanks again!

    Like

    Reply
    1. netblue30 Post author

      Question: why don’t you use the default profile for Chrome distributed by firejail?

      You’ll find it in /etc/firejail/google-*.,profile. We have profiles for all Chrome variants, including Chromium. All of them are basically the same, with very small differences. Some of features such as seccomp won’t work for Chrome browser because Chrom starts a second sandbox inside firejail sandbox.

      Like

      Reply
  10. Matthew

    Indeed sir.

    I found the /etc/firejail/google*.profile files and performed the steps (as you outlined in the profiles section here on the site) to save a new google-chrome-stable profile in my [/home/.config/firejail] directory and add the nonewprivs and noroot parameters. I also rem’ed out the caps.keep sys_chroot, sys_admin line and added caps.drop all. Now all I have to do is ‘firejail google-chrome-stable.’ I (again) apologize as I don’t really know if the chroot and admin capabilities are needed in Chrome for pure internet browsing. I conducted some on-line research on those capabilities, but couldn’t come up with anything definitive. As you can see, my working knowledge of Linux is not yet up to snuff.

    NetBlue, again my sincere thanks for an awesome program.

    Like

    Reply
  11. Pingback: Sandbox your applications with Firejail – Linux Now

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