Skip to content

Latest commit

 

History

History
258 lines (257 loc) · 7.37 KB

FEATURES.md

File metadata and controls

258 lines (257 loc) · 7.37 KB
Raw

Sandboxing feature matrix

Feature Support level
Platform Supported? Mechanism Caveats
Filesystem (mapping paths read/write) Linux ✅ bind mounts, pivot_root
macOS (sandboxd) ✔️
  • sandboxfs and chroot
  • file-read*
  • file-read-data
  • file-write*
  • file-write-data
  • file-write-mount
  • file-write-unmount
  • Requires OSXFUSE to be installed separately.
  • Directory tree is visible outside the sandbox because there is no equivalent to pivot_root in macOS.
  • Device files are not properly supported on sandboxfs. See bazelbuild/sandboxfs#87.
Filesystem (metadata read/write, e.g. ls) Linux TODO: RESEARCH
macOS (sandboxd) ✅
  • file-read-metadata
  • file-write-owner
  • file-write-setugid
  • file-write-times
Filesystem (extended attributes read/write) Linux ✅ TODO: RESEARCH
macOS (sandboxd) ✅
  • file-read-xattr, file-write-xattr
  • sandboxfs 2.0 supports extended attrributes
Filesystem (allow/deny chroot) Linux ✅ seccomp
macOS (sandboxd) ✅ file-chroot
Filesystem (procfs) Linux ✅ procfs mounts
macOS (sandboxd) ❌ procfs does not exist on macOS, so it's not applicable.
Filesystem (tmpfs) Linux ✅ tmpfs mounts
macOS (sandboxd) ✔️ Ramdisks, real directories
  • No tmpfs implementation for OSXFUSE, sadly.
  • HFS+ ramdisks are available, but they cannot swap to disk.
  • Can be emulated with a global temp dir for the current session and using sandboxfs to map subdirectories to each location where a tmpfs is requested. This has noticeable performance overhead, though, unlike real tmpfs, and the dirtree is visible outside the sandbox.
  • You can set the global temp dir location in the sandbox like this: 
    (define TMPDIR (literal "/path/to/tmpdir"))
Network (destination, protocol, port filtering) Linux ✔️ CLONE_NEWNET, netlink
  • Trivial to set up block-all, local-only, and allow-all.
  • Harder to do fine-tuned protocol and port filtering. See flatpak/flatpak#1202.
macOS (sandboxd) ✅
  • network*
  • network-bind
  • network-inbound
  • network-outbound
  • system-socket
No IP filtering; only accepts localhost or *.
Network (hiding host interfaces) Linux ✅ CLONE_NEWNET, netlink, seccomp
macOS (sandboxd) ❌ No way to hide host network interfaces on macOS because lack of namespacing. Inherits network configuration from host.
IPC (allow/deny UNIX sockets) Linux ✔️ CLONE_NEWNET, netlink No way to differentiate between TCP and UNIX sockets. You can only block all or allow all access to existing sockets or creation of new sockets.
macOS (sandboxd) ✔️
  • system-socket
  • network* (remote unix (path-literal PATH))
 No way to differentiate between TCP and UNIX sockets. You can only block all or allow all creation of new sockets. We can whitelist access to external UNIX sockets by path, though.
IPC (allow/deny SysV IPC, semaphores, Mach ports, etc.) Linux ✅ CLONE_NEWIPC, seccomp
macOS (sandboxd) ✔️
  • ipc*
  • ipc-posix*
  • ipc-posix-sem
  • ipc-posix-shm
  • ipc-sysv*
  • ipc-sysv-msg
  • ipc-sysv-sem
  • ipc-sysv-shm
  • mach-bootstrap (?)
  • mach-lookup
 No way to restrict IPC only to processes inside the sandbox due to lack of namespacing. If enabled, IPC endpoints outside the sandbox are visible.