freebsd-skq/share/man/man4/rights.4
pjd d0736de43b MFC r258148,r258149,r258150,r258152,r258153,r258154,r258181,r258182:
r258148:

Add a note that this file is compiled as part of the kernel and libc.

Requested by:	kib

r258149:

Change cap_rights_merge(3) and cap_rights_remove(3) to return pointer
to the destination cap_rights_t structure.

This already matches manual page.

r258150:

Sync return value with actual implementation.

r258151:

Style.

r258152:

Precisely document capability rights here too (they are already documented
in rights(4)).

r258153:

The CAP_LINKAT, CAP_MKDIRAT, CAP_MKFIFOAT, CAP_MKNODAT, CAP_RENAMEAT,
CAP_SYMLINKAT and CAP_UNLINKAT capability rights make no sense without
the CAP_LOOKUP right, so include this rights.

r258154:

- Move CAP_EXTATTR_* and CAP_ACL_* rights to index 1 to have more room
  in index 0 for the future.
- Move CAP_BINDAT and CAP_CONNECTAT rights to index 0 so we can include
  CAP_LOOKUP right in them.
- Shuffle the bits around so there are no gaps. This is last chance to do
  that as all moved rights are not used yet.

r258181:

Replace CAP_POLL_EVENT and CAP_POST_EVENT capability rights (which I had
a very hard time to fully understand) with much more intuitive rights:

	CAP_EVENT - when set on descriptor, the descriptor can be monitored
		with syscalls like select(2), poll(2), kevent(2).

	CAP_KQUEUE_EVENT - When set on a kqueue descriptor, the kevent(2)
		syscall can be called on this kqueue to with the eventlist
		argument set to non-NULL value; in other words the given
		kqueue descriptor can be used to monitor other descriptors.
	CAP_KQUEUE_CHANGE - When set on a kqueue descriptor, the kevent(2)
		syscall can be called on this kqueue to with the changelist
		argument set to non-NULL value; in other words it allows to
		modify events monitored with the given kqueue descriptor.

Add alias CAP_KQUEUE, which allows for both CAP_KQUEUE_EVENT and
CAP_KQUEUE_CHANGE.

Add backward compatibility define CAP_POLL_EVENT which is equal to CAP_EVENT.

r258182:

Correct right names.

Sponsored by:	The FreeBSD Foundation
Approved by:	re (kib)
2013-11-18 22:37:01 +00:00

675 lines
12 KiB
Groff

.\"
.\" Copyright (c) 2008-2010 Robert N. M. Watson
.\" Copyright (c) 2012-2013 The FreeBSD Foundation
.\" All rights reserved.
.\"
.\" This software was developed at the University of Cambridge Computer
.\" Laboratory with support from a grant from Google, Inc.
.\"
.\" Portions of this documentation were written by Pawel Jakub Dawidek
.\" under sponsorship from the FreeBSD Foundation.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\"
.\" $FreeBSD$
.\"
.Dd September 23, 2013
.Dt RIGHTS 4
.Os
.Sh NAME
.Nm Capability rights
.Nd Capsicum capability rights for file descriptors
.Sh DESCRIPTION
When a file descriptor is created by a function such as
.Xr accept 2 ,
.Xr accept4 2 ,
.Xr fhopen 2 ,
.Xr kqueue 2 ,
.Xr mq_open 2 ,
.Xr open 2 ,
.Xr openat 2 ,
.Xr pdfork 2 ,
.Xr pipe 2 ,
.Xr shm_open 2 ,
.Xr socket 2
or
.Xr socketpair 2 ,
it is assigned all capability rights.
Those rights can be reduced (but never expanded) by using the
.Xr cap_rights_limit 2 ,
.Xr cap_fcntls_limit 2 and
.Xr cap_ioctls_limit 2
system calls.
Once capability rights are reduced, operations on the file descriptor will be
limited to those permitted by rights.
.Pp
The complete list of capability rights is provided below.
The
.Vt cap_rights_t
type is used to store list of capability rights.
The
.Xr cap_rights_init 3
family of functions should be used to manage the structure.
.Pp
.Sh RIGHTS
The following rights may be specified in a rights mask:
.Bl -tag -width CAP_EXTATTR_DELETE
.It Dv CAP_ACCEPT
Permit
.Xr accept 2
and
.Xr accept4 2 .
.It Dv CAP_ACL_CHECK
Permit
.Xr acl_valid_fd_np 3 .
.It Dv CAP_ACL_DELETE
Permit
.Xr acl_delete_fd_np 3 .
.It Dv CAP_ACL_GET
Permit
.Xr acl_get_fd 3
and
.Xr acl_get_fd_np 3 .
.It Dv CAP_ACL_SET
Permit
.Xr acl_set_fd 3
and
.Xr acl_set_fd_np 3 .
.It Dv CAP_BIND
Permit
.Xr bind 2 .
Note that sockets can also become bound implicitly as a result of
.Xr connect 2
or
.Xr send 2 ,
and that socket options set with
.Xr setsockopt 2
may also affect binding behavior.
.It Dv CAP_BINDAT
Permit
.Xr bindat 2 .
This right has to be present on the directory descriptor.
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_CHFLAGSAT
An alias to
.Dv CAP_FCHFLAGS
and
.Dv CAP_LOOKUP .
.It Dv CAP_CONNECT
Permit
.Xr connect 2 ;
also required for
.Xr sendto 2
with a non-NULL destination address.
.It Dv CAP_CONNECTAT
Permit
.Xr connectat 2 .
This right has to be present on the directory descriptor.
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_CREATE
Permit
.Xr openat 2
with the
.Dv O_CREAT
flag.
.It Dv CAP_EVENT
Permit
.Xr select 2 ,
.Xr poll 2 ,
and
.Xr kevent 2
to be used in monitoring the file descriptor for events.
.It Dv CAP_EXTATTR_DELETE
Permit
.Xr extattr_delete_fd 2 .
.It Dv CAP_EXTATTR_GET
Permit
.Xr extattr_get_fd 2 .
.It Dv CAP_EXTATTR_LIST
Permit
.Xr extattr_list_fd 2 .
.It Dv CAP_EXTATTR_SET
Permit
.Xr extattr_set_fd 2 .
.It Dv CAP_FCHDIR
Permit
.Xr fchdir 2 .
.It Dv CAP_FCHFLAGS
Permit
.Xr fchflags 2
and
.Xr chflagsat 2
if the
.Dv CAP_LOOKUP
right is also present.
.It Dv CAP_FCHMOD
Permit
.Xr fchmod 2
and
.Xr fchmodat 2
if the
.Dv CAP_LOOKUP
right is also present.
.It Dv CAP_FCHMODAT
An alias to
.Dv CAP_FCHMOD
and
.Dv CAP_LOOKUP .
.It Dv CAP_FCHOWN
Permit
.Xr fchown 2
and
.Xr fchownat 2
if the
.Dv CAP_LOOKUP
right is also present.
.It Dv CAP_FCHOWNAT
An alias to
.Dv CAP_FCHOWN
and
.Dv CAP_LOOKUP .
.It Dv CAP_FCNTL
Permit
.Xr fcntl 2 .
Note that only the
.Dv F_GETFL ,
.Dv F_SETFL ,
.Dv F_GETOWN
and
.Dv F_SETOWN
commands require this capability right.
Also note that the list of permitted commands can be further limited with the
.Xr cap_fcntls_limit 2
system call.
.It Dv CAP_FEXECVE
Permit
.Xr fexecve 2
and
.Xr openat 2
with the
.Dv O_EXEC
flag;
.Dv CAP_READ
is also be required.
.It Dv CAP_FLOCK
Permit
.Xr flock 2 ,
.Xr fcntl 2
(with
.Dv F_GETLK ,
.Dv F_SETLK ,
.Dv F_SETLKW
or
.Dv F_SETLK_REMOTE
flag) and
.Xr openat 2
(with
.Dv O_EXLOCK
or
.Dv O_SHLOCK
flag).
.It Dv CAP_FPATHCONF
Permit
.Xr fpathconf 2 .
.It Dv CAP_FSCK
Permit UFS background-fsck operations on the descriptor.
.It Dv CAP_FSTAT
Permit
.Xr fstat 2
and
.Xr fstatat 2
if the
.Dv CAP_LOOKUP
right is also present.
.It Dv CAP_FSTATAT
An alias to
.Dv CAP_FSTAT
and
.Dv CAP_LOOKUP .
.It Dv CAP_FSTATFS
Permit
.Xr fstatfs 2 .
.It Dv CAP_FSYNC
Permit
.Xr aio_fsync 2 ,
.Xr fsync 2
and
.Xr openat 2
with
.Dv O_FSYNC
or
.Dv O_SYNC
flag.
.It Dv CAP_FTRUNCATE
Permit
.Xr ftruncate 2
and
.Xr openat 2
with the
.Dv O_TRUNC
flag.
.It Dv CAP_FUTIMES
Permit
.Xr futimes 2
and
.Xr futimesat 2
if the
.Dv CAP_LOOKUP
right is also present.
.It Dv CAP_FUTIMESAT
An alias to
.Dv CAP_FUTIMES
and
.Dv CAP_LOOKUP .
.It Dv CAP_GETPEERNAME
Permit
.Xr getpeername 2 .
.It Dv CAP_GETSOCKNAME
Permit
.Xr getsockname 2 .
.It Dv CAP_GETSOCKOPT
Permit
.Xr getsockopt 2 .
.It Dv CAP_IOCTL
Permit
.Xr 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
.Xr cap_ioctls_limit 2
system call.
.It Dv CAP_KQUEUE
An alias to
.Dv CAP_KQUEUE_CHANGE
and
.Dv CAP_KQUEUE_EVENT .
.It Dv CAP_KQUEUE_CHANGE
Permit
.Xr kevent 2
on a
.Xr kqueue 2
descriptor that modifies list of monitored events (the
.Fa changelist
argument is non-NULL).
.It Dv CAP_KQUEUE_EVENT
Permit
.Xr kevent 2
on a
.Xr kqueue 2
descriptor that monitors events (the
.Fa eventlist
argument is non-NULL).
.Dv CAP_EVENT
is also required on file descriptors that will be monitored using
.Xr kevent 2 .
.It Dv CAP_LINKAT
Permit
.Xr linkat 2
and
.Xr renameat 2
on the destination directory descriptor.
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_LISTEN
Permit
.Xr listen 2 ;
not much use (generally) without
.Dv CAP_BIND .
.It Dv CAP_LOOKUP
Permit the file descriptor to be used as a starting directory for calls such as
.Xr linkat 2 ,
.Xr openat 2 ,
and
.Xr unlinkat 2 .
.It Dv CAP_MAC_GET
Permit
.Xr mac_get_fd 3 .
.It Dv CAP_MAC_SET
Permit
.Xr mac_set_fd 3 .
.It Dv CAP_MKDIRAT
Permit
.Xr mkdirat 2 .
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_MKFIFOAT
Permit
.Xr mkfifoat 2 .
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_MKNODAT
Permit
.Xr mknodat 2 .
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_MMAP
Permit
.Xr mmap 2
with the
.Dv PROT_NONE
protection.
.It Dv CAP_MMAP_R
Permit
.Xr mmap 2
with the
.Dv PROT_READ
protection.
This right includes the
.Dv CAP_READ
and
.Dv CAP_SEEK
rights.
.It Dv CAP_MMAP_RW
An alias to
.Dv CAP_MMAP_R
and
.Dv CAP_MMAP_W .
.It Dv CAP_MMAP_RWX
An alias to
.Dv CAP_MMAP_R ,
.Dv CAP_MMAP_W
and
.Dv CAP_MMAP_X .
.It Dv CAP_MMAP_RX
An alias to
.Dv CAP_MMAP_R
and
.Dv CAP_MMAP_X .
.It Dv CAP_MMAP_W
Permit
.Xr mmap 2
with the
.Dv PROT_WRITE
protection.
This right includes the
.Dv CAP_WRITE
and
.Dv CAP_SEEK
rights.
.It Dv CAP_MMAP_WX
An alias to
.Dv CAP_MMAP_W
and
.Dv CAP_MMAP_X .
.It Dv CAP_MMAP_X
Permit
.Xr mmap 2
with the
.Dv PROT_EXEC
protection.
This right includes the
.Dv CAP_SEEK
right.
.It Dv CAP_PDGETPID
Permit
.Xr pdgetpid 2 .
.It Dv CAP_PDKILL
Permit
.Xr pdkill 2 .
.It Dv CAP_PDWAIT
Permit
.Xr pdwait4 2 .
.It Dv CAP_PEELOFF
Permit
.Xr sctp_peeloff 2 .
.It Dv CAP_PREAD
An alias to
.Dv CAP_READ
and
.Dv CAP_SEEK .
.It Dv CAP_PWRITE
An alias to
.Dv CAP_SEEK
and
.Dv CAP_WRITE .
.It Dv CAP_READ
Permit
.Xr aio_read 2
.Dv ( CAP_SEEK
is also required),
.Xr openat 2
with the
.Dv O_RDONLY flag,
.Xr read 2 ,
.Xr readv 2 ,
.Xr recv 2 ,
.Xr recvfrom 2 ,
.Xr recvmsg 2 ,
.Xr pread 2
.Dv ( CAP_SEEK
is also required),
.Xr preadv 2
.Dv ( CAP_SEEK
is also required) and related system calls.
.It Dv CAP_RECV
An alias to
.Dv CAP_READ .
.It Dv CAP_RENAMEAT
Permit
.Xr renameat 2 .
This right is required on the source directory descriptor.
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_SEEK
Permit operations that seek on the file descriptor, such as
.Xr lseek 2 ,
but also required for I/O system calls that can read or write at any position
in the file, such as
.Xr pread 2
and
.Xr pwrite 2 .
.It Dv CAP_SEM_GETVALUE
Permit
.Xr sem_getvalue 3 .
.It Dv CAP_SEM_POST
Permit
.Xr sem_post 3 .
.It Dv CAP_SEM_WAIT
Permit
.Xr sem_wait 3
and
.Xr sem_trywait 3 .
.It Dv CAP_SEND
An alias to
.Dv CAP_WRITE .
.It Dv CAP_SETSOCKOPT
Permit
.Xr setsockopt 2 ;
this controls various aspects of socket behavior and may affect binding,
connecting, and other behaviors with global scope.
.It Dv CAP_SHUTDOWN
Permit explicit
.Xr shutdown 2 ;
closing the socket will also generally shut down any connections on it.
.It Dv CAP_SYMLINKAT
Permit
.Xr symlinkat 2 .
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_TTYHOOK
Allow configuration of TTY hooks, such as
.Xr snp 4 ,
on the file descriptor.
.It Dv CAP_UNLINKAT
Permit
.Xr unlinkat 2
and
.Xr renameat 2 .
This right is only required for
.Xr renameat 2
on the destination directory descriptor if the destination object already
exists and will be removed by the rename.
This right includes the
.Dv CAP_LOOKUP
right.
.It Dv CAP_WRITE
Allow
.Xr aio_write 2 ,
.Xr openat 2
with
.Dv O_WRONLY
and
.Dv O_APPEND
flags set,
.Xr send 2 ,
.Xr sendmsg 2 ,
.Xr sendto 2 ,
.Xr write 2 ,
.Xr writev 2 ,
.Xr pwrite 2 ,
.Xr pwritev 2
and related system calls.
For
.Xr sendto 2
with a non-NULL connection address,
.Dv CAP_CONNECT
is also required.
For
.Xr openat 2
with the
.Dv O_WRONLY
flag, but without the
.Dv O_APPEND
flag,
.Dv CAP_SEEK
is also required.
For
.Xr aio_write 2 ,
.Xr pwrite 2
and
.Xr pwritev 2
.Dv CAP_SEEK
is also required.
.El
.Sh SEE ALSO
.Xr accept 2 ,
.Xr accept4 2 ,
.Xr aio_fsync 2 ,
.Xr aio_read 2 ,
.Xr aio_write 2 ,
.Xr bind 2 ,
.Xr bindat 2 ,
.Xr cap_enter 2 ,
.Xr cap_fcntls_limit 2 ,
.Xr cap_ioctls_limit 2 ,
.Xr cap_rights_limit 2 ,
.Xr chflagsat 2 ,
.Xr connect 2 ,
.Xr connectat 2 ,
.Xr extattr_delete_fd 2 ,
.Xr extattr_get_fd 2 ,
.Xr extattr_list_fd 2 ,
.Xr extattr_set_fd 2 ,
.Xr fchflags 2 ,
.Xr fchmod 2 ,
.Xr fchmodat 2 ,
.Xr fchown 2 ,
.Xr fchownat 2 ,
.Xr fcntl 2 ,
.Xr fexecve 2 ,
.Xr fhopen 2 ,
.Xr flock 2 ,
.Xr fpathconf 2 ,
.Xr fstat 2 ,
.Xr fstatat 2 ,
.Xr fstatfs 2 ,
.Xr fsync 2 ,
.Xr ftruncate 2 ,
.Xr futimes 2 ,
.Xr getpeername 2 ,
.Xr getsockname 2 ,
.Xr getsockopt 2 ,
.Xr ioctl 2 ,
.Xr kevent 2 ,
.Xr kqueue 2 ,
.Xr linkat 2 ,
.Xr listen 2 ,
.Xr mmap 2 ,
.Xr mq_open 2 ,
.Xr open 2 ,
.Xr openat 2 ,
.Xr pdfork 2 ,
.Xr pdgetpid 2 ,
.Xr pdkill 2 ,
.Xr pdwait4 2 ,
.Xr pipe 2 ,
.Xr poll 2 ,
.Xr pread 2 ,
.Xr preadv 2 ,
.Xr pwrite 2 ,
.Xr pwritev 2 ,
.Xr read 2 ,
.Xr readv 2 ,
.Xr recv 2 ,
.Xr recvfrom 2 ,
.Xr recvmsg 2 ,
.Xr renameat 2 ,
.Xr sctp_peeloff 2 ,
.Xr select 2 ,
.Xr send 2 ,
.Xr sendmsg 2 ,
.Xr sendto 2 ,
.Xr setsockopt 2 ,
.Xr shm_open 2 ,
.Xr shutdown 2 ,
.Xr socket 2 ,
.Xr socketpair 2 ,
.Xr symlinkat 2 ,
.Xr unlinkat 2 ,
.Xr write 2 ,
.Xr writev 2 ,
.Xr acl_delete_fd_np 3 ,
.Xr acl_get_fd 3 ,
.Xr acl_get_fd_np 3 ,
.Xr acl_set_fd 3 ,
.Xr acl_set_fd_np 3 ,
.Xr acl_valid_fd_np 3 ,
.Xr mac_get_fd 3 ,
.Xr mac_set_fd 3 ,
.Xr sem_getvalue 3 ,
.Xr sem_post 3 ,
.Xr sem_trywait 3 ,
.Xr sem_wait 3 ,
.Xr capsicum 4 ,
.Xr snp 4
.Sh HISTORY
Support for capabilities and capabilities mode was developed as part of the
.Tn TrustedBSD
Project.
.Sh AUTHORS
This manual page was created by
.An Pawel Jakub Dawidek Aq pawel@dawidek.net
under sponsorship from the FreeBSD Foundation based on
.Xr cap_new 2
manual page by
.An "Robert Watson" Aq rwatson@FreeBSD.org .