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RIGHTS(4)              FreeBSD Kernel Interfaces Manual              RIGHTS(4)

NAME
     Capability rights - Capsicum capability rights for file descriptors

DESCRIPTION
     When a file descriptor is created by a function such as accept(2),
     accept4(2), fhopen(2), kqueue(2), mq_open(2), open(2), openat(2),
     pdfork(2), pipe(2), shm_open(2), socket(2) or socketpair(2), it is
     assigned all capability rights.  Those rights can be reduced (but never
     expanded) by using the cap_rights_limit(2), cap_fcntls_limit(2) and
     cap_ioctls_limit(2) system calls.  Once capability rights are reduced,
     operations on the file descriptor will be limited to those permitted by
     rights.

     The complete list of capability rights is provided below.  The
     cap_rights_t type is used to store list of capability rights.  The
     cap_rights_init(3) family of functions should be used to manage the
     structure.

RIGHTS
     The following rights may be specified in a rights mask:

     CAP_ACCEPT           Permit accept(2) and accept4(2).

     CAP_ACL_CHECK        Permit acl_valid_fd_np(3).

     CAP_ACL_DELETE       Permit acl_delete_fd_np(3).

     CAP_ACL_GET          Permit acl_get_fd(3) and acl_get_fd_np(3).

     CAP_ACL_SET          Permit acl_set_fd(3) and acl_set_fd_np(3).

     CAP_BIND             Permit bind(2).  Note that sockets can also become
                          bound implicitly as a result of connect(2) or
                          send(2), and that socket options set with
                          setsockopt(2) may also affect binding behavior.

     CAP_BINDAT           Permit bindat(2).  This right has to be present on
                          the directory descriptor.  This right includes the
                          CAP_LOOKUP right.

     CAP_CHFLAGSAT        An alias to CAP_FCHFLAGS and CAP_LOOKUP.

     CAP_CONNECT          Permit connect(2); also required for sendto(2) with
                          a non-NULL destination address.

     CAP_CONNECTAT        Permit connectat(2).  This right has to be present
                          on the directory descriptor.  This right includes
                          the CAP_LOOKUP right.

     CAP_CREATE           Permit openat(2) with the O_CREAT flag.

     CAP_EVENT            Permit select(2), poll(2), and kevent(2) to be used
                          in monitoring the file descriptor for events.

     CAP_EXTATTR_DELETE   Permit extattr_delete_fd(2).

     CAP_EXTATTR_GET      Permit extattr_get_fd(2).

     CAP_EXTATTR_LIST     Permit extattr_list_fd(2).

     CAP_EXTATTR_SET      Permit extattr_set_fd(2).

     CAP_FCHDIR           Permit fchdir(2).

     CAP_FCHFLAGS         Permit fchflags(2) and chflagsat(2) if the
                          CAP_LOOKUP right is also present.

     CAP_FCHMOD           Permit fchmod(2) and fchmodat(2) if the CAP_LOOKUP
                          right is also present.

     CAP_FCHMODAT         An alias to CAP_FCHMOD and CAP_LOOKUP.

     CAP_FCHOWN           Permit fchown(2) and fchownat(2) if the CAP_LOOKUP
                          right is also present.

     CAP_FCHOWNAT         An alias to CAP_FCHOWN and CAP_LOOKUP.

     CAP_FCNTL            Permit fcntl(2).  Note that only the F_GETFL,
                          F_SETFL, F_GETOWN and F_SETOWN commands require this
                          capability right.  Also note that the list of
                          permitted commands can be further limited with the
                          cap_fcntls_limit(2) system call.

     CAP_FEXECVE          Permit fexecve(2) and openat(2) with the O_EXEC
                          flag; CAP_READ is also required.

     CAP_FLOCK            Permit flock(2), fcntl(2) (with F_GETLK, F_SETLK,
                          F_SETLKW or F_SETLK_REMOTE flag) and openat(2) (with
                          O_EXLOCK or O_SHLOCK flag).

     CAP_FPATHCONF        Permit fpathconf(2).

     CAP_FSCK             Permit UFS background-fsck operations on the
                          descriptor.

     CAP_FSTAT            Permit fstat(2) and fstatat(2) if the CAP_LOOKUP
                          right is also present.

     CAP_FSTATAT          An alias to CAP_FSTAT and CAP_LOOKUP.

     CAP_FSTATFS          Permit fstatfs(2).

     CAP_FSYNC            Permit aio_fsync(2), fdatasync(2), fsync(2) and
                          openat(2) with O_FSYNC or O_SYNC flag.

     CAP_FTRUNCATE        Permit ftruncate(2) and openat(2) with the O_TRUNC
                          flag.

     CAP_FUTIMES          Permit futimens(2) and futimes(2), and permit
                          futimesat(2) and utimensat(2) if the CAP_LOOKUP
                          right is also present.

     CAP_FUTIMESAT        An alias to CAP_FUTIMES and CAP_LOOKUP.

     CAP_GETPEERNAME      Permit getpeername(2).

     CAP_GETSOCKNAME      Permit getsockname(2).

     CAP_GETSOCKOPT       Permit getsockopt(2).

     CAP_IOCTL            Permit ioctl(2).  Be aware that this system call has
                          enormous scope, including potentially global scope
                          for some objects.  The list of permitted ioctl
                          commands can be further limited with the
                          cap_ioctls_limit(2) system call.

     CAP_KQUEUE           An alias to CAP_KQUEUE_CHANGE and CAP_KQUEUE_EVENT.

     CAP_KQUEUE_CHANGE    Permit kevent(2) on a kqueue(2) descriptor that
                          modifies list of monitored events (the changelist
                          argument is non-NULL).

     CAP_KQUEUE_EVENT     Permit kevent(2) on a kqueue(2) descriptor that
                          monitors events (the eventlist argument is non-
                          NULL).  CAP_EVENT is also required on file
                          descriptors that will be monitored using kevent(2).

     CAP_LINKAT_SOURCE    Permit linkat(2) on the source directory descriptor.
                          This right includes the CAP_LOOKUP right.

                          Warning: CAP_LINKAT_SOURCE makes it possible to link
                          files in a directory for which file descriptors
                          exist that have additional rights.  For example, a
                          file stored in a directory that does not allow
                          CAP_READ may be linked in another directory that
                          does allow CAP_READ, thereby granting read access to
                          a file that is otherwise unreadable.

     CAP_LINKAT_TARGET    Permit linkat(2) on the target directory descriptor.
                          This right includes the CAP_LOOKUP right.

     CAP_LISTEN           Permit listen(2); not much use (generally) without
                          CAP_BIND.

     CAP_LOOKUP           Permit the file descriptor to be used as a starting
                          directory for calls such as linkat(2), openat(2),
                          and unlinkat(2).

     CAP_MAC_GET          Permit mac_get_fd(3).

     CAP_MAC_SET          Permit mac_set_fd(3).

     CAP_MKDIRAT          Permit mkdirat(2).  This right includes the
                          CAP_LOOKUP right.

     CAP_MKFIFOAT         Permit mkfifoat(2).  This right includes the
                          CAP_LOOKUP right.

     CAP_MKNODAT          Permit mknodat(2).  This right includes the
                          CAP_LOOKUP right.

     CAP_MMAP             Permit mmap(2) with the PROT_NONE protection.

     CAP_MMAP_R           Permit mmap(2) with the PROT_READ protection.  This
                          right includes the CAP_READ and CAP_SEEK rights.

     CAP_MMAP_RW          An alias to CAP_MMAP_R and CAP_MMAP_W.

     CAP_MMAP_RWX         An alias to CAP_MMAP_R, CAP_MMAP_W and CAP_MMAP_X.

     CAP_MMAP_RX          An alias to CAP_MMAP_R and CAP_MMAP_X.

     CAP_MMAP_W           Permit mmap(2) with the PROT_WRITE protection.  This
                          right includes the CAP_WRITE and CAP_SEEK rights.

     CAP_MMAP_WX          An alias to CAP_MMAP_W and CAP_MMAP_X.

     CAP_MMAP_X           Permit mmap(2) with the PROT_EXEC protection.  This
                          right includes the CAP_SEEK right.

     CAP_PDGETPID         Permit pdgetpid(2).

     CAP_PDKILL           Permit pdkill(2).

     CAP_PDWAIT           Permit pdwait4(2).

     CAP_PEELOFF          Permit sctp_peeloff(2).

     CAP_PREAD            An alias to CAP_READ and CAP_SEEK.

     CAP_PWRITE           An alias to CAP_SEEK and CAP_WRITE.

     CAP_READ             Permit aio_read(2) (CAP_SEEK is also required),
                          openat(2) with the O_RDONLY flag, read(2), readv(2),
                          recv(2), recvfrom(2), recvmsg(2), pread(2) (CAP_SEEK
                          is also required), preadv(2) (CAP_SEEK is also
                          required) and related system calls.

     CAP_RECV             An alias to CAP_READ.

     CAP_RENAMEAT_SOURCE  Permit renameat(2) on the source directory
                          descriptor.  This right includes the CAP_LOOKUP
                          right.

                          Warning: CAP_RENAMEAT_SOURCE makes it possible to
                          move files to a directory for which file descriptors
                          exist that have additional rights.  For example, a
                          file stored in a directory that does not allow
                          CAP_READ may be moved to another directory that does
                          allow CAP_READ, thereby granting read access to a
                          file that is otherwise unreadable.

     CAP_RENAMEAT_TARGET  Permit renameat(2) on the target directory
                          descriptor.  This right includes the CAP_LOOKUP
                          right.

     CAP_SEEK             Permit operations that seek on the file descriptor,
                          such as lseek(2), but also required for I/O system
                          calls that can read or write at any position in the
                          file, such as pread(2) and pwrite(2).

     CAP_SEM_GETVALUE     Permit sem_getvalue(3).

     CAP_SEM_POST         Permit sem_post(3).

     CAP_SEM_WAIT         Permit sem_wait(3) and sem_trywait(3).

     CAP_SEND             An alias to CAP_WRITE.

     CAP_SETSOCKOPT       Permit setsockopt(2); this controls various aspects
                          of socket behavior and may affect binding,
                          connecting, and other behaviors with global scope.

     CAP_SHUTDOWN         Permit explicit shutdown(2); closing the socket will
                          also generally shut down any connections on it.

     CAP_SYMLINKAT        Permit symlinkat(2).  This right includes the
                          CAP_LOOKUP right.

     CAP_TTYHOOK          Allow configuration of TTY hooks, such as snp(4), on
                          the file descriptor.

     CAP_UNLINKAT         Permit unlinkat(2) and renameat(2).  This right is
                          only required for renameat(2) on the destination
                          directory descriptor if the destination object
                          already exists and will be removed by the rename.
                          This right includes the CAP_LOOKUP right.

     CAP_WRITE            Allow aio_write(2), openat(2) with O_WRONLY and
                          O_APPEND flags set, send(2), sendmsg(2), sendto(2),
                          write(2), writev(2), pwrite(2), pwritev(2) and
                          related system calls.  For sendto(2) with a non-NULL
                          connection address, CAP_CONNECT is also required.
                          For openat(2) with the O_WRONLY flag, but without
                          the O_APPEND flag, CAP_SEEK is also required.  For
                          aio_write(2), pwrite(2) and pwritev(2) CAP_SEEK is
                          also required.

SEE ALSO
     accept(2), accept4(2), aio_fsync(2), aio_read(2), aio_write(2), bind(2),
     bindat(2), cap_enter(2), cap_fcntls_limit(2), cap_ioctls_limit(2),
     cap_rights_limit(2), chflagsat(2), connect(2), connectat(2),
     extattr_delete_fd(2), extattr_get_fd(2), extattr_list_fd(2),
     extattr_set_fd(2), fchflags(2), fchmod(2), fchmodat(2), fchown(2),
     fchownat(2), fcntl(2), fexecve(2), fhopen(2), flock(2), fpathconf(2),
     fstat(2), fstatat(2), fstatfs(2), fsync(2), ftruncate(2), futimes(2),
     getpeername(2), getsockname(2), getsockopt(2), ioctl(2), kevent(2),
     kqueue(2), linkat(2), listen(2), mmap(2), mq_open(2), open(2), openat(2),
     pdfork(2), pdgetpid(2), pdkill(2), pdwait4(2), pipe(2), poll(2),
     pread(2), preadv(2), pwrite(2), pwritev(2), read(2), readv(2), recv(2),
     recvfrom(2), recvmsg(2), renameat(2), sctp_peeloff(2), select(2),
     send(2), sendmsg(2), sendto(2), setsockopt(2), shm_open(2), shutdown(2),
     socket(2), socketpair(2), symlinkat(2), unlinkat(2), write(2), writev(2),
     acl_delete_fd_np(3), acl_get_fd(3), acl_get_fd_np(3), acl_set_fd(3),
     acl_set_fd_np(3), acl_valid_fd_np(3), mac_get_fd(3), mac_set_fd(3),
     sem_getvalue(3), sem_post(3), sem_trywait(3), sem_wait(3), capsicum(4),
     snp(4)

HISTORY
     Support for capabilities and capabilities mode was developed as part of
     the TrustedBSD Project.

AUTHORS
     This manual page was created by Pawel Jakub Dawidek <[email protected]>
     under sponsorship from the FreeBSD Foundation based on the cap_new(2)
     manual page by Robert Watson <[email protected]>.

FreeBSD 11.1-RELEASE-p4         August 17, 2016        FreeBSD 11.1-RELEASE-p4
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