NAME

     Capsicum — lightweight OS capability and sandbox framework

SYNOPSIS

     options CAPABILITY_MODE
     options CAPABILITIES
     options PROCDESC

DESCRIPTION

     Capsicum is a lightweight OS capability and sandbox framework implementing a hybrid
     capability system model.  Capsicum can be used for application and library
     compartmentalisation, the decomposition of larger bodies of software into isolated
     (sandboxed) components in order to implement security policies and limit the impact of
     software vulnerabilities.

     Capsicum provides two core kernel primitives:

     capability mode
             A process mode, entered by invoking cap_enter(2), in which access to global OS
             namespaces (such as the file system and PID namespaces) is restricted; only
             explicitly delegated rights, referenced by memory mappings or file descriptors, may
             be used.  Once set, the flag is inherited by future children processes, and may not
             be cleared.

     capabilities
             File descriptors that wrap other file descriptors, masking operations that can be
             called on them; for example, a file descriptor returned by open(2) may be refined
             using cap_new(2) so that only read(2) and write(2) can be called, but not fchmod(2).

     In some cases, Capsicum requires use of alternatives to traditional POSIX APIs in order to
     name objects using capabilities rather than global namespaces:

     process descriptors
             File descriptors representing processes, allowing parent processes to manage child
             processes without requiring access to the PID namespace.

     anonymous shared memory
             An extension to the POSIX shared memory API to support anonymous swap objects
             associated with file descriptors.

SEE ALSO

     cap_enter(2), cap_getmode(2), cap_getrights(2), cap_new(2), fchmod(2), open(2), pdfork(2),
     pdgetpid(2), pdkill(2), pdwait4(2), read(2), shm_open(2), write(2)

HISTORY

     Capsicum first appeared in FreeBSD 9.0, and was developed at the University of Cambridge.

AUTHORS

     Capsicum was developed by Robert Watson <rwatson@FreeBSD.org> and Jonathan Anderson
     <jonathan@FreeBSD.org> at the University of Cambridge, and Ben Laurie <benl@FreeBSD.org> and
     Kris Kennaway <kris@FreeBSD.org> at Google, Inc.

BUGS

     Capsicum is considered experimental in FreeBSD.