FIREJAIL(1)

NAME
Firejail - Linux namespaces sandbox program

SYNOPSIS
Start a sandbox:

    firejail [OPTIONS] [program and arguments]

Start an AppImage program:

    firejail [OPTIONS] --appimage [OPTIONS] [appimage-file and arguments]

File transfer from an existing sandbox

    firejail {--ls | --get | --put | --cat} 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-syscalls32 | --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 applications 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.

Firejail is currently implemented as an SUID binary, which means that if a malicious or compromised user account manages to exploit a bug in Firejail, that could ultimately lead to a privilege escalation to root. To mitigate this, it is recommended to only allow trusted users to run firejail (see firejail-users(5) for details on how to achieve that). For more details on the security/usability tradeoffs of Firejail, see: #4601 (https://github.com/netblue30/firejail/discussions/4601).

Alternative sandbox technologies like Snap (see https://snapcraft.io) and Flatpak (see https://flatpak.org) are not supported. Snap and Flatpak packages have their own native management tools and will not work when sandboxed with Firejail.

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.

Upon execution Firejail first looks in ~/.config/firejail/ for a profile and if it doesn't find one, it looks in /etc/firejail/. If an appropriate profile is not found, Firejail will use a default profile. The default profile is quite restrictive. In case the application doesn't work, use --noprofile option to disable it.

If a program argument is not specified, Firejail starts the user's preferred shell. Examples:

$ firejail [OPTIONS] # starting the program specified in $SHELL, usually /bin/bash

$ firejail [OPTIONS] /usr/bin/firefox # starting Mozilla Firefox

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

When an option is specified multiple times (whether in a profile, on the command line, or both) or conflicts with a related option, the precedence/behavior is option-specific and usually documented in the OPTIONS section below. Note that an option specified in a profile can generally be disabled on the command line using --ignore.

OPTIONS

--  Signal the end of options and disables further option processing.

--allow-bwrap
    By default firejail replaces /usr/bin/bwrap executable with a do-nothing program. Our replacement just runs the bubblewrap target, and is visible only inside firejail sandbox. Use this option to disable this default functionality.
    Example:
    $ firejail --noprofile --allow-bwrap bwrap --help
    firejail version 0.9.77
    Parent pid 44129, child pid 44130
    Base filesystem installed in 0.04 ms
    Child process initialized in 5.02 ms
    usage: bwrap [OPTIONS...] [--] COMMAND [ARGS...]
        --help Print this help
        --version Print version
        --args FD Parse NUL-separated args from FD

--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/firefox.profile strace -f /usr/bin/firefox
    See also --private-etc and --trace.

--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 with the "firejail-default" AppArmor profile. For more information, please see APPARMOR section below.

--apparmor=profile_name
    Enable AppArmor confinement with a custom AppArmor profile. Note that profile in question must already be loaded into the kernel. For more information, please see APPARMOR section below.

--apparmor.print=name|pid
    Print the AppArmor confinement status for the sandbox identified by name or by PID.
    Example:
    $ firejail --apparmor.print=browser
    5074:netblue:/usr/bin/firejail /usr/bin/firefox-esr
      AppArmor: firejail-default enforce

--appimage
    Sandbox an AppImage (see https://appimage.org) application. If the sandbox is started as a regular user, nonewprivs and a default capabilities filter are enabled. private-bin and private-lib are disabled by default when running appimages.
    Example:
    $ firejail --appimage --profile=krita krita-3.0-x86_64.appimage
    $ firejail --quiet --appimage --private --profile=krita krita-3.0-x86_64.appimage
    $ firejail --appimage --net=none --x11 --profile=krita krita-3.0-x86_64.appimage
    Note: When using both --appimage and --profile, it is recommended to always specify the former before the latter, so that any ?HAS_APPIMAGE conditionals inside of the profile evaluate to true (see ?CONDITIONAL in firejail-profile(5)).

--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. This makes a file or directory completely inaccessible. All other files and directories are unaffected. The blacklisted file or directory is still visible on the filesystem, even if it's inaccessible.
    Symbolic link handling: Blacklisting a path that is a symbolic link will also blacklist the path that it points to. For example, if ~/foo is blacklisted and it points to /bar, then /bar will also be blacklisted.
    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"

--build
    The command builds a whitelisted profile. The profile is printed on the screen. The program is run in a very relaxed sandbox, with only --caps.drop=all and --seccomp=!chroot. Programs that raise user privileges are not supported.
    Note: This option is intended for profile debugging and development. The profile that is generated may be incomplete, non-functional and lacking in security. If you want to try to create a new profile, see CONTRIBUTING.md.
    Example:
    $ firejail --build /usr/bin/vlc ~/Videos/test.mp4
    $ firejail --build --appimage ~/Downloads/Subsurface.AppImage

--build=profile-file
    The command builds a whitelisted profile, and saves it in profile-file. The program is run in a very relaxed sandbox, with only --caps.drop=all and --seccomp=!chroot. Programs that raise user privileges are not supported.
    Note: This option is intended for profile debugging and development. The profile that is generated may be incomplete, non-functional and lacking in security. If you want to try to create a new profile, see CONTRIBUTING.md.
    Example:
    $ firejail --build=vlc.profile /usr/bin/vlc ~/Videos/test.mp4
    $ firejail --build=Subsurface.profile --appimage ~/Downloads/Subsurface.AppImage

-c  Login shell compatibility option. This option is use by some login programs when executing the login shell, such as when firejail is used as a restricted login shell. It currently does not change the execution of firejail.

--caps
    Linux capabilities is a kernel feature designed to split up the root privilege into a set of distinct privileges. These privileges can be enabled or disabled independently, thus restricting what a process running as root can do in the system. See capabilities(7) for details. By default root programs run with all capabilities enabled. --caps option disables the following capabilities: CAP_SYS_MODULE, CAP_SYS_RAWIO, CAP_SYS_BOOT, CAP_SYS_NICE, CAP_SYS_TTY_CONFIG, 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 unofficial sources - such as games, Java programs, etc.
    Example:
    $ firejail --caps.drop=all /usr/bin/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 /usr/bin/warzone2100 &
    $ firejail --caps.print=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/firefox
    $ firejail --caps.print=3272

--cat=name|pid filename
    Print content of file from sandbox container, see FILE TRANSFER section for more details.

--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, nonewprivs and a default capabilities filter are enabled.
    Example:
    $ firejail --chroot=/media/ubuntu /usr/bin/warzone2100
    For automatic mounting of X11 and PulseAudio sockets set environment variables FIREJAIL_CHROOT_X11 and FIREJAIL_CHROOT_PULSE.
    Note: Support for this command is controlled in firejail.config with the chroot option.

--cpu=cpu-number,cpu-number,cpu-number
    Set CPU affinity.
    Example:
    $ firejail --cpu=0,1 /usr/bin/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 /usr/bin/warzone2100 &
    $ firejail --cpu.print=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/firefox
    $ firejail --cpu.print=3272

--dbus-log=file
    Specify the location for the DBus log file.
    The log file contains events for both the system and session buses if both of the --dbus-system.log and --dbus-user.log options are specified. If no log file path is given, logs are written to the standard output instead.
    Example:
    $ firejail --dbus-system=filter --dbus-system.log \
    --dbus-log=dbus.txt

--dbus-system=filter|none
    Set system DBus sandboxing policy.
    The filter policy enables the system DBus filter. This option requires installing the xdg-dbus-proxy utility. Permissions for well-known can be specified with the --dbus-system.talk and --dbus-system.own options.
    The none policy disables access to the system DBus.
    Only the regular system DBus UNIX socket is handled by this option. To disable the abstract sockets (and force applications to use the filtered UNIX socket) you would need to request a new network namespace using --net command. Another option is to remove unix from the --protocol set.
    Example:
    $ firejail --dbus-system=none

--dbus-system.broadcast=name=[member][@path]
    Allows the application to receive broadcast signals from the indicated interface member at the indicated object path exposed by the indicated bus name on the system DBus. The name may have a .* suffix to match all names underneath it, including itself. The interface member may have a .* to match all members of an interface, or be * to match all interfaces. The path may have a /* suffix to indicate all objects underneath it, including itself. Omitting the interface member or the object path will match all members and object paths, respectively.
    Example:
    $ firejail --dbus-system=filter --dbus-system.broadcast=\
    org.freedesktop.Notifications=\
    org.freedesktop.Notifications.*@/org/freedesktop/Notifications

--dbus-system.call=name=[member][@path]
    Allows the application to call the indicated interface member at the indicated object path exposed by the indicated bus name on the system DBus. The name may have a .* suffix to match all names underneath it, including itself. The interface member may have a .* to match all members of an interface, or be * to match all interfaces. The path may have a /* suffix to indicate all objects underneath it, including itself. Omitting the interface member or the object path will match all members and object paths, respectively.
    Example:
    $ firejail --dbus-system=filter --dbus-system.call=\
    org.freedesktop.Notifications=\
    org.freedesktop.Notifications.*@/org/freedesktop/Notifications

--dbus-system.log
    Turn on DBus logging for the system DBus. This option requires --dbus-system=filter.
    Example:
    $ firejail --dbus-system=filter --dbus-system.log

--dbus-system.own=name
    Allows the application to own the specified well-known name on the system DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-system=filter --dbus-system.own=\
    org.gnome.ghex.*

--dbus-system.see=name
    Allows the application to see, but not talk to the specified well-known name on the system DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-system=filter --dbus-system.see=\
    org.freedesktop.Notifications

--dbus-system.talk=name
    Allows the application to talk to the specified well-known name on the system DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-system=filter --dbus-system.talk=\
    org.freedesktop.Notifications

--dbus-user=filter|none
    Set session DBus sandboxing policy.
    The filter policy enables the session DBus filter. This option requires installing the xdg-dbus-proxy utility. Permissions for well-known names can be added with the --dbus-user.talk and --dbus-user.own options.
    The none policy disables access to the session DBus.
    Only the regular session DBus UNIX socket is handled by this option. To disable the abstract sockets (and force applications to use the filtered UNIX socket) you would need to request a new network namespace using --net command. Another option is to remove unix from the --protocol set.
    Example:
    $ firejail --dbus-user=none

--dbus-user.broadcast=name=[member][@path]
    Allows the application to receive broadcast signals from the indicated interface member at the indicated object path exposed by the indicated bus name on the session DBus. The name may have a .* suffix to match all names underneath it, including itself. The interface member may have a .* to match all members of an interface, or be * to match all interfaces. The path may have a /* suffix to indicate all objects underneath it, including itself. Omitting the interface member or the object path will match all members and object paths, respectively.
    Example:
    $ firejail --dbus-user=filter --dbus-user.broadcast=\
    org.freedesktop.Notifications=\
    org.freedesktop.Notifications.*@/org/freedesktop/Notifications

--dbus-user.call=name=[member][@path]
    Allows the application to call the indicated interface member at the indicated object path exposed by the indicated bus name on the session DBus. The name may have a .* suffix to match all names underneath it, including itself. The interface member may have a .* to match all members of an interface, or be * to match all interfaces. The path may have a /* suffix to indicate all objects underneath it, including itself. Omitting the interface member or the object path will match all members and object paths, respectively.
    Example:
    $ firejail --dbus-user=filter --dbus-user.call=\
    org.freedesktop.Notifications=\
    org.freedesktop.Notifications.*@/org/freedesktop/Notifications

--dbus-user.log
    Turn on DBus logging for the session DBus. This option requires --dbus-user=filter.
    Example:
    $ firejail --dbus-user=filter --dbus-user.log

--dbus-user.own=name
    Allows the application to own the specified well-known name on the session DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-user=filter --dbus-user.own=org.gnome.ghex.*

--dbus-user.see=name
    Allows the application to see, but not talk to the specified well-known name on the session DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-user=filter --dbus-user.see=\
    org.freedesktop.Notifications

--dbus-user.talk=name
    Allows the application to talk to the specified well-known name on the session DBus. The name may have a .* suffix to match all names underneath it, including itself (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar").
    Example:
    $ firejail --dbus-user=filter --dbus-user.talk=\
    org.freedesktop.Notifications

--debug
    Print debug messages.
    Example:
    $ firejail --debug /usr/bin/firefox

--debug-blacklists
    Debug blacklisting.
    Example:
    $ firejail --debug-blacklists /usr/bin/firefox

--debug-caps
    Print all recognized capabilities in the current Firejail software build and exit.
    Example:
    $ firejail --debug-caps

--debug-errnos
    Print all recognized error numbers in the current Firejail software build and exit.
    Example:
    $ firejail --debug-errnos

--debug-protocols
    Print all recognized protocols in the current Firejail software build and exit.
    Example:
    $ firejail --debug-protocols

--debug-syscall-groups[=@group1,@group2,@all,...]
    Print all system call groups and descriptions then exit.
    Specify seccomp groups separated by a comma to print their system calls in the current Firejail software build and exit. The special group @all can be used to print all seccomp groups and related syscalls.
    Example:
    $ firejail --debug-syscall-groups
    $ firejail --debug-syscall-groups=@chown,@mount,@swap
    $ firejail --debug-syscall-groups=@all

--debug-syscalls
    Print all recognized system calls in the current Firejail software build and exit.
    Example:
    $ firejail --debug-syscalls
    Note: The syscall mapping comes directly from the architecture-specific .tbl files in the Linux kernel sources, which are transformed into header files in src/include and built into firejail. Only syscalls for the build target architecture and 32-bit variants (if applicable) are included in the build, such as for x86_64 and x86 (respectively). If a syscall number or name is not listed, it is not recognized by firejail. This may be due to a syscall not being present in the .tbl file (such as for obsolete syscalls), not having been added to firejail yet or the current build of firejail being too old.
    Example .tbl files for x86_64 and x86 on Linux v6.19:
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/entry/syscalls/syscall_64.tbl?h=v6.19
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/entry/syscalls/syscall_32.tbl?h=v6.19

--debug-syscalls32
    Print all recognized 32 bit system calls in the current Firejail software build and exit. This is the same as --debug-syscalls, but for the 32-bit syscalls.

--debug-whitelists
    Debug whitelisting.
    Example:
    $ firejail --debug-whitelists /usr/bin/firefox

--defaultgw=address
    Use this address as default gateway in the new network namespace.
    Example:
    $ firejail --net=eth0 --defaultgw=10.10.20.1 /usr/bin/firefox

--deterministic-exit-code
    Always exit firejail with the first child's exit status. The default behavior is to use the exit status of the final child to exit, which can be nondeterministic.

--deterministic-shutdown
    Always shut down the sandbox after the first child has terminated. The default behavior is to keep the sandbox alive as long as it contains running processes.

--disable-mnt
    Blacklist /mnt, /media, /run/mount and /run/media access.
    Example:
    $ firejail --disable-mnt /usr/bin/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 /usr/bin/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 /usr/bin/warzone2100 &
    $ firejail --dns.print=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/firefox
    $ firejail --dns.print=3272

--dnstrace[=name|pid]
    Monitor DNS queries. The sandbox can be specified by name or pid. Only networked sandboxes created with --net are supported. This option is only available when running the sandbox as root.
    Without a name/pid, Firejail will monitor the main system network namespace.
    Example:
    $ sudo firejail --dnstrace
    11:31:43 9.9.9.9 linux.com (type 1)
    11:31:45 9.9.9.9 fonts.googleapis.com (type 1) NXDOMAIN
    11:31:45 9.9.9.9 js.hs-scripts.com (type 1) NXDOMAIN
    11:31:45 9.9.9.9 www.linux.com (type 1)
    11:31:45 9.9.9.9 fonts.googleapis.com (type 1) NXDOMAIN
    11:31:52 9.9.9.9 js.hs-scripts.com (type 1) NXDOMAIN
    11:32:05 9.9.9.9 secure.gravatar.com (type 1)
    11:32:06 9.9.9.9 secure.gravatar.com (type 1)
    11:32:08 9.9.9.9 taikai.network (type 1)
    11:32:08 9.9.9.9 cdn.jsdelivr.net (type 1)
    11:32:08 9.9.9.9 taikai.azureedge.net (type 1)
    11:32:08 9.9.9.9 www.youtube.com (type 1)

--env=name=value
    Set environment variable in the new sandbox.
    Example:
    $ firejail --env=LD_LIBRARY_PATH=/opt/test/lib

--fs.print=name|pid
    Print the filesystem log for the sandbox identified by name or by PID.
    Example:
    $ firejail --name=mygame --caps.drop=all /usr/bin/warzone2100 &
    $ firejail --fs.print=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/firefox
    $ firejail --fs.print=3272

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

-?, --help
    Print options end exit.

--hostname=name
    Set sandbox hostname.
    This is incompatible with --hostname-randomize.
    For valid names, see the NAME VALIDATION section.
    Example:
    $ firejail --hostname=officepc /usr/bin/firefox

--hostname-randomize
    Set sandbox hostname to a random value generated by firejail.
    This is incompatible with --hostname.
    Example:
    $ firejail --hostname-randomize /usr/bin/firefox
    Note: Changing the hostname may cause breakage related to networking (see #7048 (https://github.com/netblue30/firejail/issues/7048)) and may cause X11 programs to crash on startup due to not being able to authenticate to the X server (see #7062 (https://github.com/netblue30/firejail/issues/7062)).

--hosts-file=file
    Use file as /etc/hosts.
    Example:
    $ firejail --hosts-file=~/myhosts /usr/bin/firefox

--icmptrace[=name|pid]
    Monitor ICMP traffic. The sandbox can be specified by name or pid. Only networked sandboxes created with --net are supported. This option is only available when running the sandbox as root.
    Without a name/pid, Firejail will monitor the main system network namespace.
    Example
    $ sudo firejail --icmptrace
    20:53:54 192.168.1.60 -> 142.250.65.174 - 98 bytes - Echo request/0
    20:53:54 142.250.65.174 -> 192.168.1.60 - 98 bytes - Echo reply/0
    20:53:55 192.168.1.60 -> 142.250.65.174 - 98 bytes - Echo request/0
    20:53:55 142.250.65.174 -> 192.168.1.60 - 98 bytes - Echo reply/0
    20:53:55 192.168.1.60 -> 1.1.1.1 - 154 bytes - Destination unreachable/Port unreachable

--ignore=command
    Ignore command in profile file.
    Example:
    $ firejail --ignore=seccomp --ignore=caps /usr/bin/firefox
    $ firejail --ignore="net eth0" /usr/bin/firefox

--include=file.profile
    Include a profile file before the regular profiles are used.
    Example:
    $ firejail --include=/etc/firejail/disable-devel.inc /usr/bin/gedit

--interface=interface
    Move interface in a new network namespace. Up to four --interface options can be specified. Note: wlan devices are not supported 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 /usr/bin/firefox

--ip=dhcp
    Acquire an IP address and default gateway for the last interface defined by a --net option, as well as set the DNS servers according to the DHCP response. This option requires the ISC dhclient DHCP client to be installed and will start it automatically inside the sandbox.
    Example:
    $ firejail --net=br0 --ip=dhcp
    This option should not be used in conjunction with the --dns option if the DHCP server is set to configure DNS servers for the clients, because the manually specified DNS servers will be overwritten.
    The DHCP client will NOT release the DHCP lease when the sandbox terminates. If your DHCP server requires leases to be explicitly released, consider running a DHCP client and releasing the lease manually in conjunction with the --net=none option.

--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 configured, 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 /usr/bin/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).

--ip6=dhcp
    Acquire an IPv6 address and default gateway for the last interface defined by a --net option, as well as set the DNS servers according to the DHCP response. This option requires the ISC dhclient DHCP client to be installed and will start it automatically inside the sandbox.
    Example:
    $ firejail --net=br0 --ip6=dhcp
    This option should not be used in conjunction with the --dns option if the DHCP server is set to configure DNS servers for the clients, because the manually specified DNS servers will be overwritten.
    The DHCP client will NOT release the DHCP lease when the sandbox terminates. If your DHCP server requires leases to be explicitly released, consider running a DHCP client and releasing the lease manually.

--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 regular user. IPC namespace is enabled by default for sandboxes started as root.
    Note: This only affects the IPC resources that are mentioned in ipc_namespaces(7). It does not affect other IPC resources, such as Unix sockets (see unix(7)).
    Example:
    $ firejail --ipc-namespace /usr/bin/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 program 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 and cpus configurations are not applied to the process joining the sandbox.
    Example:
    $ firejail --name=mygame --caps.drop=all /usr/bin/warzone2100 &
    $ firejail --join=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/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 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 and cpus configurations are not applied to the process joining the sandbox. Example:
    # start firefox
    $ firejail --net=eth0 --name=browser /usr/bin/firefox &
    # change netfilter configuration
    $ sudo firejail --join-network=browser bash -c "cat /etc/firejail/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 sandbox
    1: lo: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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 ...". See --name for details.
    Note that in contrary to other join options there is respective profile option.

--keep-config-pulse
    Disable automatic ~/.config/pulse init, for complex setups such as remote pulse servers or non-standard socket paths.
    Example:
    $ firejail --keep-config-pulse /usr/bin/firefox

--keep-dev-ntsync
    Allow access to the /dev/ntsync character device (even with --private-dev), which is blocked by default. This device is mostly intended to increase performance and compatibility when running certain programs through Wine.
    Example:
    $ firejail --keep-dev-ntsync --private-dev

--keep-dev-shm
    /dev/shm directory is untouched (even with --private-dev)
    Example:
    $ firejail --keep-dev-shm --private-dev

--keep-dev-tpm
    Allow access to Trusted Cryptography Module (TCM) and Trusted Platform Module (TPM) devices (even with --private-dev), which are blocked by default.
    Paths:
    /dev/tcm[0-9]*
    /dev/tcmrm[0-9]*
    /dev/tpm[0-9]*
    /dev/tpmrm[0-9]*
    Example:
    $ firejail --keep-dev-tpm --private-dev

--keep-fd=all
    Inherit all open file descriptors to the sandbox. By default only file descriptors 0, 1 and 2 are inherited to the sandbox, and all other file descriptors are closed.
    Example:
    $ firejail --keep-fd=all

--keep-fd=file_descriptor
    Don't close specified open file descriptors. By default only file descriptors 0, 1 and 2 are inherited to the sandbox, and all other file descriptors are closed.
    Example:
    $ firejail --keep-fd=3,4,5

--keep-shell-rc
    By default, when using a private home directory, firejail copies files from the system's user home template (/etc/skel) into it, which overrides attempts to whitelist the original files (such as ~/.bashrc and ~/.zshrc). This option disables this feature, and enables the user to whitelist the original files.

--keep-var-tmp
    /var/tmp directory is untouched.
    Example:
    $ firejail --keep-var-tmp

--landlock.enforce (experimental)
    Enforce the Landlock ruleset. Without it, the other Landlock commands have no effect. See the LANDLOCK section for more information.

--landlock.fs.read=path (experimental)
    Create a Landlock ruleset (if it doesn't already exist) and add a read access rule for path.

--landlock.fs.write=path (experimental)
    Create a Landlock ruleset (if it doesn't already exist) and add a write access rule for path.

--landlock.fs.makeipc=path (experimental)
    Create a Landlock ruleset (if it doesn't already exist) and add a rule that allows the creation of named pipes (FIFOs) and Unix domain sockets beneath the given path.

--landlock.fs.makedev=path (experimental)
    Create a Landlock ruleset (if it doesn't already exist) and add a rule that allows the creation of block devices and character devices beneath the given path.

--landlock.fs.execute=path (experimental)
    Create a Landlock ruleset (if it doesn't already exist) and add an execution permission rule for path.
    Example:
    $ firejail --landlock.fs.read=/ --landlock.fs.write=/home --landlock.fs.execute=/usr --landlock.enforce

--list
    List all sandboxes, see MONITORING section for more details.
    Example:
    $ firejail --list
    7015:netblue:browser:firejail /usr/bin/firefox
    7056:netblue:torrent:firejail --net=eth0 /usr/bin/transmission-gtk
    7064:netblue::firejail --noroot /usr/bin/xterm

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

--mac=address
    Assign MAC addresses to the last network interface defined by a --net option. This option is not supported for wireless interfaces.
    Example:
    $ firejail --net=eth0 --mac=00:11:22:33:44:55 /usr/bin/firefox

--machine-id
    Spoof id number in /etc/machine-id file - a new random id is generated inside the sandbox. Note that this breaks audio support. Enable it when sound is not required.
    Example:
    $ firejail --machine-id

--memory-deny-write-execute
    Install a seccomp filter to block attempts to create memory mappings 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, memfd_create and shmat system calls and returns error EPERM to the process (or kills it or log the attempt, see --seccomp-error-action below) if necessary.
    Note: shmat is not implemented as a system call on some platforms including i386, and it cannot be handled by seccomp-bpf.

--mkdir=dirname
    Create a directory in user home. Parent directories are created as needed.
    Example:
    $ firejail --mkdir=~/work/project

--mkfile=filename
    Create an empty file in user home.
    Example:
    $ firejail --mkfile=~/work/project/readme

--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 --shutdown, can use this name to identify a sandbox. The name cannot contain only digits, as that is treated as a PID in the other options, such as in --join.
    For valid names, see the NAME VALIDATION section.
    In case the name supplied by the user is already in use by another sandbox, Firejail will assign a new name as "name-PID", where PID is the process ID of the sandbox. This functionality can be disabled at run time in /etc/firejail/firejail.config file, by setting "name-change" flag to "no".
    Example:
    $ firejail --name=browser /usr/bin/firefox &
    $ firejail --name=browser --private /usr/bin/firefox --no-remote &
    $ firejail --list
    1198:netblue:browser:firejail --name=browser /usr/bin/firefox
    1312:netblue:browser-1312:firejail --name=browser --private /usr/bin/firefox --no-remote

--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 automatically 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 options can be specified.
    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|wireless_interface
    Enable a new network namespace and connect it to this ethernet interface using the standard Linux macvlan|ipvlan driver. Unless specified 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 options can be specified. Support for ipvlan driver was introduced in Linux kernel 3.19.
    Example:
    $ firejail --net=eth0 --ip=192.168.1.80 --dns=8.8.8.8 /usr/bin/firefox
    $ firejail --net=wlan0 /usr/bin/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 /usr/bin/vlc
    Note: --net=none can crash the application on some platforms. In these cases, it can be replaced with --protocol=unix.

--net=tap_interface
    Enable a new network namespace and connect it to this ethernet tap interface using the standard Linux macvlan driver. If the tap interface is not configured, the sandbox will not try to configure the interface inside the sandbox. Please use --ip, --netmask and --defaultgw to specify the configuration.
    Example:
    $ firejail --net=tap0 --ip=10.10.20.80 --netmask=255.255.255.0 --defaultgw=10.10.20.1 /usr/bin/firefox

--net.print=name|pid
    If a new network namespace is enabled, print network interface configuration for the sandbox specified by name or PID. Example:
    $ firejail --net.print=browser
    Switching to pid 1853, the first child process inside the sandbox
    Interface MAC IP Mask Status
    lo 127.0.0.1 255.0.0.0 UP
    eth0-1852 5e:fb:8e:27:29:26 192.168.1.186 255.255.255.0 UP

--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 applications. 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 /usr/bin/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/nolocal6.net is a desktop client firewall that disable access to local network. Example:
    $ firejail --netfilter=/etc/firejail/nolocal.net \
    --net=eth0 /usr/bin/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 /usr/bin/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 /usr/bin/firefox &
    $ firejail --netfilter6.print=browser

--netlock
    Several type of programs (email clients, multiplayer games etc.) talk to a very small number of IP addresses. But the best example is tor browser. It only talks to a guard node, and there are two or three more on standby in case the main one fails. During startup, the browser contacts all of them, after that it keeps talking to the main one... for weeks! Use the network locking feature to build and deploy a custom network firewall in your sandbox. The firewall allows only the traffic to the IP addresses detected during the program startup. Traffic to any other address is quietly dropped. By default the network monitoring time is one minute. A network namespace (--net=eth0) is required for this feature to work. Example:
    $ firejail --net=eth0 --netlock \
    --private=~/tor-browser_en-US ./start-tor-browser.desktop

--netmask=address
    Use this option when you want to assign an IP address in a new namespace and the parent interface specified by --net is not configured. An IP address and a default gateway address also have to be added. By default the new namespace interface comes without IP address and default gateway configured. Example:
    $ sudo /sbin/brctl addbr br0
    $ sudo /sbin/ifconfig br0 up
    $ firejail --ip=10.10.20.67 --netmask=255.255.255.0 --defaultgw=10.10.20.1

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

--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 /usr/bin/firefox
    7383 netblue 9.045 0.112 firejail --net=eth0 /usr/bin/transmission

--nettrace[=name|pid]
    Monitor received TCP. UDP, and ICMP traffic. The sandbox can be specified by name or pid. Only networked sandboxes created with --net are supported. This option is only available when running the sandbox as root.
    Without a name/pid, Firejail will monitor the main system network namespace.
    Example:
    $ sudo firejail --nettrace
                           93 KB/s address:port (protocol) network
      14 B/s ** 104.24.8.4:443(QUIC) Cloudflare
      80 KB/s ***************** 192.187.97.90:443(TLS) BitChute
       1 B/s 149.56.228.45:443(DoH) Canada
    (D)isplay, (S)ave, (C)lear, e(X)it
    If /usr/bin/geoiplookup is installed (geoip-bin package in Debian), the country the traffic originates from is added to the trace. We also use the static IP map in /usr/lib/firejail/static-ip-map to print the domain names for some of the more common websites and cloud platforms. No external services are contacted for reverse IP lookup.

--nice=value
    Set nice value for all processes running inside the sandbox. Only root may specify a negative value.
    Example:
    $ firejail --nice=2 /usr/bin/firefox

--no3d
    Disable 3D hardware acceleration.
    Example:
    $ firejail --no3d /usr/bin/firefox

--noautopulse (deprecated)
    See --keep-config-pulse.

--noblacklist=dirname_or_filename
    Disable blacklist for this directory or file.
    Note that blacklist entries containing ${PATH} can not currently be partially disabled for individual expanded paths. Only the whole unexpanded path including ${PATH} can be disabled, which then applies to all expansions. This limitation does not apply to expansions of other variables or wildcards. For details, see #6360 (https://github.com/netblue30/firejail/issues/6360).
    Example:
    $ firejail
    $ nc dict.org 2628
    bash: /bin/nc: Permission denied
    $ exit
    $ firejail --noblacklist=/bin/nc
    bash: /bin/nc: Permission denied
    $ exit
    $ firejail --noblacklist='${PATH}/nc'
    $ nc dict.org 2628
    220 pan.alephnull.com dictd 1.12.1/rf on Linux 3.14-1-amd64

--nodbus (deprecated)
    Disable D-Bus access (both system and session buses). Equivalent to --dbus-system=none --dbus-user=none.
    Example:
    $ firejail --nodbus --net=none

--nodvd
    Disable DVD and audio CD devices.
    Example:
    $ firejail --nodvd

--noexec=dirname_or_filename
    Remount directory or file noexec, nodev and nosuid. File globbing 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.

--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(netblue),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)
    $

--noinput
    Disable input devices.
    Example:
    $ firejail --noinput

--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 capabilities) does not result in an increase of privilege. This option is enabled by default if seccomp filter is activated.

--noprinters
    Disable printers.

--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 --appimage 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
    $

--nosound
    Disable sound system.
    Example:
    $ firejail --nosound /usr/bin/firefox

--notpm (deprecated)
    Ignored for compatibility.
    TPM devices are now blocked by default, see --keep-dev-tpm.

--notv
    Disable DVB (Digital Video Broadcasting) TV devices.
    Example:
    $ firejail --notv /usr/bin/vlc

--nou2f
    Disable U2F devices.
    Example:
    $ firejail --nou2f

--novideo
    Disable video devices.

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

--oom=value
    Configure kernel's OutOfMemory-killer score for this sandbox. The acceptable score values are between 0 and 1000 for regular users, and -1000 to 1000 for root. For more information on OOM kernel feature see man choom.
    Example:
    $ firejail --oom=300 /usr/bin/firefox

--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.

--private
    Mount new /root and /home/user directories in temporary filesystems. All modifications are discarded when the sandbox is closed.
    Example:
    $ firejail --private /usr/bin/firefox

--private=directory
    Use directory as user home. --private and --private=directory cannot be used together.
    Example:
    $ firejail --private=/home/netblue/firefox-home /usr/bin/firefox
    Bug: Even with this enabled, some firejail commands (such as mkdir, mkfile and private-cache) will still operate on the original home directory. Workaround: Disable the incompatible commands, such as by using "ignore mkdir" and "ignore mkfile". For details, see #903 (https://github.com/netblue30/firejail/issues/903).

--private-bin=file,file
    Build a new /bin in a temporary filesystem, and copy the programs in the list. The files in the list must be expressed as relative to the /bin, /sbin, /usr/bin, /usr/sbin, or /usr/local/bin directories. If no listed files are found, /bin directory will be empty. The same directory is also bind-mounted over /sbin, /usr/bin, /usr/sbin and /usr/local/bin. All modifications are discarded when the sandbox is closed. Multiple private-bin commands are allowed and they accumulate. File globbing is supported, see FILE GLOBBING section for more details.
    Example:
    $ firejail --private-bin=bash,cat,ls,sed
    Parent pid 20841, child pid 20842
    Child process initialized
    $ ls /bin
    bash cat ls sed

--private-cache
    Mount an empty temporary filesystem on top of the .cache directory in user home. All modifications are discarded when the sandbox is closed.
    Example:
    $ firejail --private-cache /usr/bin/openbox

--private-cwd
    Set working directory inside jail to the home directory, and failing that, the root directory. Does not impact working directory of profile include paths.
    Example:
    $ pwd
    /tmp
    $ firejail --private-cwd
    $ pwd
    /home/user

--private-cwd=directory
    Set working directory inside the jail. Full directory path is required. Symbolic links are not allowed. Does not impact working directory of profile include paths.
    Example:
    $ pwd
    /tmp
    $ firejail --private-cwd=/opt
    $ pwd
    /opt

--private-dev
    Create a new /dev directory. Only disc, dri, dvb, full, hidraw, log, null, ptmx, pts, random, shm, snd, tty, urandom, usb, video and zero devices are available. Use the options --no3d, --nodvd, --nosound, --notv, --nou2f and --novideo for additional restrictions.
    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, --private-etc=@group,file,directory
    The files installed by --private-etc are copies of the original system files from /etc directory. By default, the command brings in a skeleton of files and directories used by most console tools: $ firejail --private-etc /usr/bin/dig debian.org For X11/GTK/QT/Gnome/KDE programs add @x11 group as a parameter. Example: $ firejail --private-etc=@x11,gcrypt,python* /usr/bin/gimp gcrypt and /etc/python* directories are not part of the generic @x11 group. File globbing is supported. For games, add @games group: $ firejail --private-etc=@games,@x11 /usr/bin/warzone2100 Sound and networking files are included automatically, unless --nosound or --net=none are specified. Files for encrypted TLS/SSL protocol are in @tls-ca group. $ firejail --private-etc=@tls-ca,wgetrc /usr/bin/wget https://debian.org Note: The easiest way to extract the list of /etc files accessed by your program is by using the strace utility. Example: $ strace -f --trace=%file /usr/bin/transmission-qt 2>&1 | grep etc $ firejail --allow-debuggers --profile=/etc/firejail/transmission-qt.profile strace -f --trace=%file /usr/bin/transmission-qt 2>&1 | grep etc See also --allow-debuggers and --trace.

--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. The files and directories in the list must be expressed as relative to the current user's home directory. All modifications are discarded when the sandbox is closed.
    Example:
    $ firejail --private-home=.mozilla /usr/bin/firefox

--private-opt=file,directory
    Build a new /opt in a temporary filesystem, and copy the files and directories in the list. The files and directories in the list must be expressed as relative to the /opt directory, and must not contain the / character (e.g., /opt/foo must be expressed as foo, but /opt/foo/bar -- expressed as foo/bar -- is disallowed). 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
    Note: Program installations in /opt tend to be relatively large and private-opt copies the entire path(s) into RAM, which may significantly increase RAM usage and break file-copy-limit in firejail.config. Therefore, in general it is recommended to use "whitelist /opt/PATH" instead of "private-opt PATH". For details, see #5307 (https://github.com/netblue30/firejail/discussions/5307).

--private-srv=file,directory
    Build a new /srv in a temporary filesystem, and copy the files and directories in the list. The files and directories in the list must be expressed as relative to the /srv directory, and must not contain the / character (e.g., /srv/foo must be expressed as foo, but /srv/foo/bar -- expressed as srv/bar -- is disallowed). 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-PKdhtXMmr18n
    drwxrwxrwt 2 nobody nogroup 4096 Apr 30 10:52 .X11-unix

--profile=filename|appname
    Load a custom security profile from filename, or use the name of a specific application.
    If the command line option --profile is not provided, Firejail will attempt to extract the appname from the target program filename. It will then search ~/.config/firejail directory for a suitable profile, followed by a search in /etc/firejail/directory.
    Example:
    $ firejail /usr/bin/firefox
    Reading profile /home/netblue/.config/firejail/firefox.profile
    Reading profile /etc/firejail/firefox.profile
    Reading profile /etc/firejail/firefox-common.profile
    [...]
    When using a filename, please include a full path or a relative path.
    $ firejail --profile=./firefox.profile /usr/bin/firefox
    Reading profile ./firefox.profile
    Reading profile /etc/firejail/firefox.profile
    Reading profile /etc/firejail/firefox-common.profile
    [...]
    --profile=appname comes in handy when running appimages:
    $ firejail --appimage --profile=firefox firefox-nightly-148.0.r20260103-x86_64.AppImage
    Reading profile /home/netblue/.config/firejail/firefox.profile
    Reading profile /etc/firejail/firefox.profile
    Reading profile /etc/firejail/firefox-common.profile
    [...]
    See man 5 firejail-profile for profile file syntax information. For profile resolution details see https://github.com/netblue30/firejail/wiki/Creating-Profiles.

--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, packet, and bluetooth. This option is not supported for i386 architecture. Multiple protocol commands are allowed and they accumulate.
    Example:
    $ firejail --protocol=unix,inet,inet6 /usr/bin/firefox

--protocol.print=name|pid
    Print the protocol filter for the sandbox identified by name or PID.
    Example:
    $ firejail --name=mybrowser /usr/bin/firefox &
    $ firejail --protocol.print=mybrowser
    unix,inet,inet6,netlink
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/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.
    The same effect can be obtained by setting an environment variable FIREJAIL_QUIET to yes.

--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 /usr/bin/firefox

--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

--restrict-namespaces
    Install a seccomp filter that blocks attempts to create new cgroup, ipc, net, mount, pid, time, user or uts namespaces.
    Example:
    $ firejail --restrict-namespaces

--restrict-namespaces=cgroup,ipc,net,mnt,pid,time,user,uts
    Install a seccomp filter that blocks attempts to create any of the specified namespaces. The filter examines the arguments of clone, unshare and setns system calls and returns error EPERM to the process (or kills it or logs the attempt, see --seccomp-error-action below) if necessary. Note that the filter is not able to examine the arguments of clone3 system calls, and always responds to these calls with error ENOSYS.
    Example:
    $ firejail --restrict-namespaces=user,net

--rlimit-as=number
    Set the maximum size of the process's virtual memory (address space) in bytes. You can use K(ibibyte), M(ebibyte) or G(ibibyte) as a suffix, such as "100M" (which is equivalent to 104857600 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. You can use K(ibibyte), M(ebibyte) or G(ibibyte) as a suffix, such as "100M" (which is equivalent to 104857600 bytes).

--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 running on the current host.
    Example:
    $ firejail --net=eth0 --scan

--seccomp
    Enable seccomp filter and blacklist the syscalls in the default list, which is @default-nodebuggers unless --allow-debuggers is specified, then it is @default.
    To help creating useful seccomp filters more easily, the following system call groups are defined: @aio, @basic-io, @chown, @clock, @cpu-emulation, @debug, @default, @default-nodebuggers, @default-keep, @file-system, @io-event, @ipc, @keyring, @memfd, @memlock, @module, @mount, @network-io, @obsolete, @privileged, @process, @raw-io, @reboot, @resources, @sandbox, @setuid, @swap, @sync, @system-service and @timer. More information about groups can be found in /usr/share/doc/firejail/syscalls.txt and see also --debug-syscall-groups.
    The default list can be customized, see --seccomp= for a description. It can be customized also globally in /etc/firejail/firejail.config file.
    System architecture is strictly imposed only if flag --seccomp.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,!syscall2
    Enable seccomp filter, blacklist the default list and the syscalls or syscall groups specified by the command, but don't blacklist "syscall2". On a 64 bit architecture, an additional filter for 32 bit system calls can be installed with --seccomp.32.
    Example:
    $ firejail --seccomp=utime,utimensat,utimes /usr/bin/firefox
    $ firejail --seccomp=@clock,mkdir,unlinkat /usr/bin/transmission-gtk
    $ firejail '--seccomp=@ipc,!pipe,!pipe2' audacious
    Syscalls can be specified by their number if the "$" prefix is added, so for example "$165" corresponds to "mount" on the x86_64 architecture.
    The syscall numbers and names for --seccomp can be found by using --debug-syscalls and --debug-syscalls32 for --seccomp.32.
    Instead of dropping the syscall by returning EPERM, another error number can be returned using syscall:errno syntax. This can be also changed globally with --seccomp-error-action or in /etc/firejail/firejail.config file. The process can also be killed by using syscall:kill syntax, or the attempt may be logged with syscall:log.
    Example:
    $ firejail --seccomp=unlinkat:ENOENT,utimensat,utimes
    Parent pid 10662, child pid 10663
    Child process initialized
    $ touch testfile
    $ ls testfile
    testfile
    $ rm testfile
    rm: cannot remove `testfile': No such file or directory
    If the blocked system calls would also block Firejail from operating, they are handled by adding a preloaded library which performs seccomp system calls later. However, this is incompatible with 32 bit seccomp filters.
    Example:
    $ firejail --noprofile --seccomp=execve sh
    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
    Operation not permitted

--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. On a 64 bit architecture, an additional filter for 32 bit system calls can be installed with --seccomp.32.drop.
    Example:
    $ firejail --seccomp.drop=utime,utimensat,utimes,@clock
    Instead of dropping the syscall by returning EPERM, another error number can be returned using syscall:errno syntax. This can be also changed globally with --seccomp-error-action or in /etc/firejail/firejail.config file. The process can also be killed by using syscall:kill syntax, or the attempt may be logged with syscall:log.
    Example:
    $ firejail --seccomp.drop=unlinkat:ENOENT,utimensat,utimes
    Parent pid 10662, child pid 10663
    Child process initialized
    $ touch testfile
    $ ls testfile
    testfile
    $ rm testfile
    rm: cannot remove `testfile': No such file or directory

--seccomp.keep=syscall,@group,!syscall2
    Enable seccomp filter, blacklist all syscall not listed and "syscall2". The system calls needed by Firejail (group @default-keep: prctl, execve, execveat) are handled with the preload library. On a 64 bit architecture, an additional filter for 32 bit system calls can be installed with --seccomp.32.keep.
    Example:
    $ firejail --seccomp.keep=poll,select,[...] /usr/bin/transmission-gtk

--seccomp.print=name|pid
    Print the seccomp filter for the sandbox identified by name or PID.
    Example:
    $ firejail --name=browser /usr/bin/firefox &
    $ firejail --seccomp.print=browser
     line OP JT JF K
    =================================
     0000: 20 00 00 00000004 ld data.architecture
     0001: 15 01 00 c000003e jeq ARCH_64 0003 (false 0002)
     0002: 06 00 00 7fff0000 ret ALLOW
     0003: 20 00 00 00000000 ld data.syscall-number
     0004: 35 01 00 40000000 jge X32_ABI true:0006 (false 0005)
     0005: 35 01 00 00000000 jge read 0007 (false 0006)
     0006: 06 00 00 00050001 ret ERRNO(1)
     0007: 15 41 00 0000009a jeq modify_ldt 0049 (false 0008)
     0008: 15 40 00 000000d4 jeq lookup_dcookie 0049 (false 0009)
     0009: 15 3f 00 0000012a jeq perf_event_open 0049 (false 000a)
     000a: 15 3e 00 00000137 jeq process_vm_writev 0049 (false 000b)
     000b: 15 3d 00 0000009c jeq _sysctl 0049 (false 000c)
     000c: 15 3c 00 000000b7 jeq afs_syscall 0049 (false 000d)
     000d: 15 3b 00 000000ae jeq create_module 0049 (false 000e)
     000e: 15 3a 00 000000b1 jeq get_kernel_syms 0049 (false 000f)
     000f: 15 39 00 000000b5 jeq getpmsg 0049 (false 0010)
     0010: 15 38 00 000000b6 jeq putpmsg 0049 (false 0011)
     0011: 15 37 00 000000b2 jeq query_module 0049 (false 0012)
     0012: 15 36 00 000000b9 jeq security 0049 (false 0013)
     0013: 15 35 00 0000008b jeq sysfs 0049 (false 0014)
     0014: 15 34 00 000000b8 jeq tuxcall 0049 (false 0015)
     0015: 15 33 00 00000086 jeq uselib 0049 (false 0016)
     0016: 15 32 00 00000088 jeq ustat 0049 (false 0017)
     0017: 15 31 00 000000ec jeq vserver 0049 (false 0018)
     0018: 15 30 00 0000009f jeq adjtimex 0049 (false 0019)
     0019: 15 2f 00 00000131 jeq clock_adjtime 0049 (false 001a)
     001a: 15 2e 00 000000e3 jeq clock_settime 0049 (false 001b)
     001b: 15 2d 00 000000a4 jeq settimeofday 0049 (false 001c)
     001c: 15 2c 00 000000b0 jeq delete_module 0049 (false 001d)
     001d: 15 2b 00 00000139 jeq finit_module 0049 (false 001e)
     001e: 15 2a 00 000000af jeq init_module 0049 (false 001f)
     001f: 15 29 00 000000ad jeq ioperm 0049 (false 0020)
     0020: 15 28 00 000000ac jeq iopl 0049 (false 0021)
     0021: 15 27 00 000000f6 jeq kexec_load 0049 (false 0022)
     0022: 15 26 00 00000140 jeq kexec_file_load 0049 (false 0023)
     0023: 15 25 00 000000a9 jeq reboot 0049 (false 0024)
     0024: 15 24 00 000000a7 jeq swapon 0049 (false 0025)
     0025: 15 23 00 000000a8 jeq swapoff 0049 (false 0026)
     0026: 15 22 00 000000a3 jeq acct 0049 (false 0027)
     0027: 15 21 00 00000141 jeq bpf 0049 (false 0028)
     0028: 15 20 00 000000a1 jeq chroot 0049 (false 0029)
     0029: 15 1f 00 000000a5 jeq mount 0049 (false 002a)
     002a: 15 1e 00 000000b4 jeq nfsservctl 0049 (false 002b)
     002b: 15 1d 00 0000009b jeq pivot_root 0049 (false 002c)
     002c: 15 1c 00 000000ab jeq setdomainname 0049 (false 002d)
     002d: 15 1b 00 000000aa jeq sethostname 0049 (false 002e)
     002e: 15 1a 00 000000a6 jeq umount2 0049 (false 002f)
     002f: 15 19 00 00000099 jeq vhangup 0049 (false 0030)
     0030: 15 18 00 000000ee jeq set_mempolicy 0049 (false 0031)
     0031: 15 17 00 00000100 jeq migrate_pages 0049 (false 0032)
     0032: 15 16 00 00000117 jeq move_pages 0049 (false 0033)
     0033: 15 15 00 000000ed jeq mbind 0049 (false 0034)
     0034: 15 14 00 00000130 jeq open_by_handle_at 0049 (false 0035)
     0035: 15 13 00 0000012f jeq name_to_handle_at 0049 (false 0036)
     0036: 15 12 00 000000fb jeq ioprio_set 0049 (false 0037)
     0037: 15 11 00 00000067 jeq syslog 0049 (false 0038)
     0038: 15 10 00 0000012c jeq fanotify_init 0049 (false 0039)
     0039: 15 0f 00 00000138 jeq kcmp 0049 (false 003a)
     003a: 15 0e 00 000000f8 jeq add_key 0049 (false 003b)
     003b: 15 0d 00 000000f9 jeq request_key 0049 (false 003c)
     003c: 15 0c 00 000000fa jeq keyctl 0049 (false 003d)
     003d: 15 0b 00 000000ce jeq io_setup 0049 (false 003e)
     003e: 15 0a 00 000000cf jeq io_destroy 0049 (false 003f)
     003f: 15 09 00 000000d0 jeq io_getevents 0049 (false 0040)
     0040: 15 08 00 000000d1 jeq io_submit 0049 (false 0041)
     0041: 15 07 00 000000d2 jeq io_cancel 0049 (false 0042)
     0042: 15 06 00 000000d8 jeq remap_file_pages 0049 (false 0043)
     0043: 15 05 00 00000116 jeq vmsplice 0049 (false 0044)
     0044: 15 04 00 00000087 jeq personality 0049 (false 0045)
     0045: 15 03 00 00000143 jeq userfaultfd 0049 (false 0046)
     0046: 15 02 00 00000065 jeq ptrace 0049 (false 0047)
     0047: 15 01 00 00000136 jeq process_vm_readv 0049 (false 0048)
     0048: 06 00 00 7fff0000 ret ALLOW
     0049: 06 00 01 00000000 ret KILL
    $

--seccomp-error-action= kill | ERRNO | log
    By default, if a seccomp filter blocks a system call, the process gets EPERM as the error. With --seccomp-error-action=error, another error number can be returned, for example ENOSYS or EACCES. The process can also be killed (like in versions <0.9.63 of Firejail) by using --seccomp-error-action=kill syntax, or the attempt may be logged with --seccomp-error-action=log. Not killing the process weakens Firejail slightly when trying to contain intrusion, but it may also allow tighter filters if the only alternative is to allow a system call.

--shutdown=name|pid
    Shutdown the sandbox identified by name or PID.
    Example:
    $ firejail --name=mygame --caps.drop=all /usr/bin/warzone2100 &
    $ firejail --shutdown=mygame
    Example:
    $ firejail --list
    3272:netblue::firejail --private /usr/bin/firefox
    $ firejail --shutdown=3272

--snitrace[=name|pid]
    Monitor Server Name Indication (TLS/SNI). The sandbox can be specified by name or pid. Only networked sandboxes created with --net are supported. This option is only available when running the sandbox as root.
    Without a name/pid, Firejail will monitor the main system network namespace.
    Example:
    $ sudo firejail --snitrace
    07:49:51 23.185.0.3 linux.com
    07:49:51 23.185.0.3 www.linux.com
    07:50:05 192.0.73.2 secure.gravatar.com
    07:52:35 172.67.68.93 www.howtoforge.com
    07:52:37 13.225.103.59 sf.ezoiccdn.com
    07:52:42 142.250.176.3 www.gstatic.com
    07:53:03 173.236.250.32 www.linuxlinks.com
    07:53:05 192.0.77.37 c0.wp.com
    07:53:08 192.0.78.32 jetpack.wordpress.com
    07:53:09 192.0.77.32 s0.wp.com
    07:53:09 192.0.77.2 i0.wp.com
    07:53:10 192.0.77.2 i0.wp.com
    07:53:11 192.0.73.2 1.gravatar.com

--tab
    Enable shell tab completion in sandboxes using private or whitelisted home directories.
    $ firejail --private --tab

--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 /usr/bin/firefox

--tmpfs=dirname
    Mount a writable tmpfs filesystem on directory dirname. Directories outside user home or not owned by the user are not allowed. Sandboxes running as root are exempt from these restrictions. File globbing is supported, see FILE GLOBBING section for more details.
    Example:
    $ firejail --tmpfs=~/.local/share

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

--trace[=filename]
    Trace open, access and connect system calls. If filename is specified, log trace output to filename, otherwise log to console.
    Example:
    $ firejail --trace /usr/bin/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...
    See also --allow-debuggers and --private-etc.

--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 /usr/bin/firefox
    Sample messages:
    $ sudo tail -f /var/log/syslog
    [...]
    Dec 3 11:43:25 debian firejail[70]: blacklist violation - sandbox 26370, exe firefox, syscall open64, path /etc/shadow
    Dec 3 11:46:17 debian firejail[70]: blacklist violation - sandbox 26370, exe firefox, syscall opendir, path /boot
    [...]
    Note: Support for this command is controlled in firejail.config with the tracelog option.

--tree
    Print a tree of all sandboxed processes, see MONITORING section for more details.
    Example:
    $ firejail --tree
    11903:netblue:firejail /usr/bin/iceweasel
      11904:netblue:iceweasel
        11957:netblue:/usr/lib/iceweasel/plugin-container
    11969:netblue:firejail --net=eth0 /usr/bin/transmission-gtk
      11970:netblue:transmission-gtk

--unhide-pid1
    Pid 1 is always present inside Firejail sandbox. By restricting access to /proc kernel interface, general tools like ps are unable to view and access this process. --unhide-pid1 option disables this functionality. Example:
    $ firejail --name=test ### by default pid 1 is not visible
    [...]
    Child process initialized in 59.41 ms
    $ ps a
        PID TTY STAT TIME COMMAND
          4 ? S 0:00 /bin/bash
          5 ? R+ 0:00 ps a
    $ exit
    Parent is shutting down, bye…
    $ firejail --name=test --unhide-pid1 ### pid 1 is visible
    [...]
    Child process initialized in 58.29 ms
    $ ps a
       PID TTY STAT TIME COMMAND
          1 ? S 0:00 firejail --name=test --unhide-pid1
          4 ? S 0:00 /bin/bash
          6 ? R+ 0:00 ps a
    $ exit
    Parent is shutting down, bye…

--version
    Print program version/compile time support and exit.
    Example:
    $ firejail --version
    firejail version 0.9.27 Compile time support:
        - AppArmor support is enabled
        - AppImage support is enabled
        - chroot support is enabled
        - file and directory whitelisting support is enabled
        - file transfer support is enabled
        - firetunnel support is enabled
        - networking support is enabled
        - private-home support is enabled
        - seccomp-bpf support is enabled
        - user namespace support is enabled
        - X11 sandboxing support is enabled

--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. In the context of firejail, top directory means, if the whitelisted file's path is for example /etc/somedir/somefile, then the top directory would be /etc. All other top directories like /opt, /usr and so on, haven't changed, so all files there are still accessible, unless a file or directory inside them is also whitelisted. This is why sometimes it's beneficial to use blacklist in combination with whitelist, if used for different top directories.
    The whitelisted files are mount-binded inside. Modifications to whitelisted files are persistent, everything else in the same top directory is discarded when the sandbox is closed.
    The top directory can be most directories in /, but there are some special cases. The /proc and /sys top directories aren't allowed, but /sys/module is allowed. Also /run/user/$UID, $HOME and all directories in /usr are treated as a top directory.
    Symbolic link handling: Whitelisting a path that is a symbolic link will also whitelist the path that it points to. For example, if ~/foo is whitelisted and it points to ~/bar, then ~/bar will also be whitelisted.
    Restrictions: With the exception of the user home directory, both the link and the real file should be in the same top directory. For symbolic links in the user home directory, both the link and the real file should be owned by the user.
    File globbing is supported, see FILE GLOBBING section for more details.
    Example:
    $ firejail --noprofile --whitelist=~/.mozilla
    $ firejail --whitelist=/tmp/.X11-unix --whitelist=/dev/null
    $ firejail --whitelist="/home/username/My Virtual Machines"
    $ firejail --whitelist=/home/username/My\ Virtual\ Machines
    $ firejail --whitelist=~/work* --whitelist=/var/backups*

--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 security extension. The sandbox will prevent screenshot and keylogger applications started inside the sandbox from accessing clients running outside the sandbox. Firejail will try Xephyr first, and if Xephyr is not installed on the system, it will try to find Xpra. 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 /usr/bin/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 manager inside the sandbox. A security profile for OpenBox is provided.
    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 /usr/bin/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 distributions. It provides support for a simple trusted/untrusted connection 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 /usr/bin/firefox

--x11=xpra
    Start Xpra (see 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 /usr/bin/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 /usr/bin/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 connect to our server:
    $ vncviewer

--xephyr-extra-params=OPTIONS
    Set Xephyr server command extra parameters for x11 --x11=xephyr. The setting will overwrite the default set in /etc/firejail/firejail.config for the current sandbox. Run Xephyr -help to get a list of available options.
    Example:
    $ firejail --net=eth0 --x11=xephyr --xephyr-extra-params="-title firefox" /usr/bin/firefox

--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 /usr/bin/firefox

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 local customizations must be placed in /etc/apparmor.d/local/firejail-local. The profile needs to be loaded into the kernel by reloading apparmor.service, rebooting the system or running the following command as root:
    # apparmor_parser -r /etc/apparmor.d/firejail-default

The installed profile is supplemental for main firejail functions and among other things does the following:
    - Disable ptrace. With ptrace it is possible to inspect and hijack running programs. Usually this is needed only for debugging. You should have no problems running Chromium or Firefox. This feature is available only on Ubuntu kernels.
    - Whitelist write access to several files under /run, /proc and /sys.
    - Allow running programs only from well-known system paths, such as /bin, /sbin, /usr/bin etc. Those paths are available as read-only. Running programs and scripts from user home or other directories writable by the user is not allowed.
    - Prevent using non-standard network sockets. Only unix, inet, inet6, netlink, raw and packet are allowed.
    - Deny access to known sensitive paths like .snapshots.

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 /usr/bin/firefox

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:
    $ sudo 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 /usr/bin/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 /usr/bin/firefox
      1190:netblue:firejail /usr/bin/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 firecfg(1) for more details.

EXAMPLES

firejail
    Sandbox a regular shell session.

firejail /usr/bin/firefox
    Start Mozilla Firefox.

firejail --debug /usr/bin/firefox
    Debug Firefox sandbox.

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

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

firejail --net=eth0 /usr/bin/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 shell 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.

FILE GLOBBING

Globbing is the operation that expands a wildcard pattern into the
    list of pathnames matching the pattern. This pattern is matched at firejail start, and is NOT UPDATED at runtime. Files matching a blacklist, but created after firejail start will be accessible within the jail. Matching is defined by:
    - '?' matches any character
    - '*' matches any string
    - '[' denotes a range of characters

The globbing 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,
    --private-bin, --noexec, --read-only, --read-write, --tmpfs, and --whitelist.

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

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

--cat=name|pid filename
    Write content of a container file to standard out. The container is specified by name or PID. If standard out is a terminal, all ASCII control characters except new line and horizontal tab are replaced.

--get=name|pid filename
    Retrieve the container file and store it on the host in the current 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 specified by name or PID.

Examples:
    $ firejail --name=mybrowser --private /usr/bin/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
    $ firejail --cat=mybrowser ~/.bashrc

LANDLOCK
Warning: Landlock support in firejail is considered experimental and unstable. The contents of landlock-common.inc are likely to change and the feature is still being expanded upon in the Linux kernel. Also, note that its functionality overlaps with existing firejail features, such as the blacklist, read-only and read-write commands. Its filesystem access rules can currently only restrict direct access to paths; it is not able to make only select paths appear in the sandbox such as with the whitelist and private-etc commands (see also unveil(2) on OpenBSD). Lastly, note that depending on the Linux kernel version, Landlock may not protect all of the relevant syscalls (see the kernel's Landlock documentation for details). Therefore, it is recommended to treat Landlock as an extra layer of protection, to be used together with other firejail features (rather than as a bulletproof mechanism by itself).

Landlock is a Linux security module first introduced in version 5.13 of the Linux kernel. It allows unprivileged processes to restrict their access to the filesystem. Once imposed, these restrictions can never be removed, and all child processes created by a Landlock-restricted processes inherit these restrictions. Firejail supports Landlock as an additional sandboxing feature. It can be used to ensure that a sandboxed application can only access files and directories that it was explicitly allowed to access. Firejail supports populating the ruleset with both a basic set of rules (see landlock-common.inc) and with a custom set of rules.

Important notes:

    - Currently only Landlock ABI version 1 is supported.

    - If "lsm=" is used in the kernel command line, it should contain "landlock" (such as "lsm=apparmor,landlock"), or else it will be disabled.

    - A process can install a Landlock ruleset only if it has either CAP_SYS_ADMIN in its effective capability set, or the "No New Privileges" restriction enabled. Because of this, enabling the Landlock feature will also cause Firejail to enable the "No New Privileges" restriction, regardless of the profile or the --nonewprivs command line option.

    - Access to the /etc directory is automatically allowed. To override this, use the --writable-etc command line option. You can also use the --private-etc option to restrict access to the /etc directory.

To enable Landlock self-restriction on top of your current Firejail security features, pass --landlock.enforce flag to Firejail command line. Without it, the other Landlock commands have no effect. Example:

$ firejail --landlock.enforce --landlock.fs.read=/media /usr/bin/mc

To disable Landlock self-restriction, use --ignore=landlock.enforce.

MONITORING
Option --list prints a list of all sandboxes. The format for each process entry is as follows:
    PID:USER:Sandbox Name:Command Option --tree prints the tree of processes running in the sandbox. The format for each process entry is as follows:
    PID:USER:Sandbox Name: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 --netstats 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 controlling 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.

Sandbox Name
    The name of the sandbox, if any.

SHR Shared Memory Size (KiB), it reflects memory shared with other processes. It is a sum of the SHR values for all processes running 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.

NAME VALIDATION
For simplicity, the same name validation is used for multiple options. Rules:

The name must be 1-253 characters long. The name can only contain ASCII letters, digits and the special characters "-._" (that is, the name cannot contain spaces or control characters). The name cannot contain only digits. The first and last characters must be an ASCII letter or digit and the name may contain special characters in the middle.

RESTRICTED SHELL
To configure a restricted shell, replace /bin/bash with /usr/bin/firejail 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.

TRAFFIC SHAPING
Network bandwidth is an expensive resource shared among all sandboxes running on a system. Traffic shaping allows the user to increase network 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 command 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 /usr/bin/firefox &
    $ firejail --bandwidth=mybrowser set eth0 80 20
    $ firejail --bandwidth=mybrowser status
    $ firejail --bandwidth=mybrowser clear eth0

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), firejail-users(5), jailcheck(1) https://github.com/netblue30/firejail/wiki, https://github.com/netblue30/firejail