1/*-
2 * Copyright (c) 2008-2010 Robert N. M. Watson
3 * Copyright (c) 2012 FreeBSD Foundation
4 * All rights reserved.
5 *
6 * This software was developed at the University of Cambridge Computer
7 * Laboratory with support from a grant from Google, Inc.
8 *
9 * Portions of this software were developed by Pawel Jakub Dawidek under
10 * sponsorship from the FreeBSD Foundation.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD$
34 */
35
36/*
37 * Definitions for FreeBSD capabilities facility.
38 */
39#ifndef _SYS_CAPSICUM_H_
40#define	_SYS_CAPSICUM_H_
41
42#include <sys/cdefs.h>
43#include <sys/param.h>
44
45#include <sys/caprights.h>
46#include <sys/file.h>
47#include <sys/fcntl.h>
48
49#ifndef _KERNEL
50#include <stdbool.h>
51#endif
52
53#define	CAPRIGHT(idx, bit)	((1ULL << (57 + (idx))) | (bit))
54
55/*
56 * Possible rights on capabilities.
57 *
58 * Notes:
59 * Some system calls don't require a capability in order to perform an
60 * operation on an fd.  These include: close, dup, dup2.
61 *
62 * sendfile is authorized using CAP_READ on the file and CAP_WRITE on the
63 * socket.
64 *
65 * mmap() and aio*() system calls will need special attention as they may
66 * involve reads or writes depending a great deal on context.
67 */
68
69/* INDEX 0 */
70
71/*
72 * General file I/O.
73 */
74/* Allows for openat(O_RDONLY), read(2), readv(2). */
75#define	CAP_READ		CAPRIGHT(0, 0x0000000000000001ULL)
76/* Allows for openat(O_WRONLY | O_APPEND), write(2), writev(2). */
77#define	CAP_WRITE		CAPRIGHT(0, 0x0000000000000002ULL)
78/* Allows for lseek(fd, 0, SEEK_CUR). */
79#define	CAP_SEEK_TELL		CAPRIGHT(0, 0x0000000000000004ULL)
80/* Allows for lseek(2). */
81#define	CAP_SEEK		(CAP_SEEK_TELL | 0x0000000000000008ULL)
82/* Allows for aio_read(2), pread(2), preadv(2). */
83#define	CAP_PREAD		(CAP_SEEK | CAP_READ)
84/*
85 * Allows for aio_write(2), openat(O_WRONLY) (without O_APPEND), pwrite(2),
86 * pwritev(2).
87 */
88#define	CAP_PWRITE		(CAP_SEEK | CAP_WRITE)
89/* Allows for mmap(PROT_NONE). */
90#define	CAP_MMAP		CAPRIGHT(0, 0x0000000000000010ULL)
91/* Allows for mmap(PROT_READ). */
92#define	CAP_MMAP_R		(CAP_MMAP | CAP_SEEK | CAP_READ)
93/* Allows for mmap(PROT_WRITE). */
94#define	CAP_MMAP_W		(CAP_MMAP | CAP_SEEK | CAP_WRITE)
95/* Allows for mmap(PROT_EXEC). */
96#define	CAP_MMAP_X		(CAP_MMAP | CAP_SEEK | 0x0000000000000020ULL)
97/* Allows for mmap(PROT_READ | PROT_WRITE). */
98#define	CAP_MMAP_RW		(CAP_MMAP_R | CAP_MMAP_W)
99/* Allows for mmap(PROT_READ | PROT_EXEC). */
100#define	CAP_MMAP_RX		(CAP_MMAP_R | CAP_MMAP_X)
101/* Allows for mmap(PROT_WRITE | PROT_EXEC). */
102#define	CAP_MMAP_WX		(CAP_MMAP_W | CAP_MMAP_X)
103/* Allows for mmap(PROT_READ | PROT_WRITE | PROT_EXEC). */
104#define	CAP_MMAP_RWX		(CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
105/* Allows for openat(O_CREAT). */
106#define	CAP_CREATE		CAPRIGHT(0, 0x0000000000000040ULL)
107/* Allows for openat(O_EXEC) and fexecve(2) in turn. */
108#define	CAP_FEXECVE		CAPRIGHT(0, 0x0000000000000080ULL)
109/* Allows for openat(O_SYNC), openat(O_FSYNC), fsync(2), aio_fsync(2). */
110#define	CAP_FSYNC		CAPRIGHT(0, 0x0000000000000100ULL)
111/* Allows for openat(O_TRUNC), ftruncate(2). */
112#define	CAP_FTRUNCATE		CAPRIGHT(0, 0x0000000000000200ULL)
113
114/* Lookups - used to constrain *at() calls. */
115#define	CAP_LOOKUP		CAPRIGHT(0, 0x0000000000000400ULL)
116
117/* VFS methods. */
118/* Allows for fchdir(2). */
119#define	CAP_FCHDIR		CAPRIGHT(0, 0x0000000000000800ULL)
120/* Allows for fchflags(2). */
121#define	CAP_FCHFLAGS		CAPRIGHT(0, 0x0000000000001000ULL)
122/* Allows for fchflags(2) and chflagsat(2). */
123#define	CAP_CHFLAGSAT		(CAP_FCHFLAGS | CAP_LOOKUP)
124/* Allows for fchmod(2). */
125#define	CAP_FCHMOD		CAPRIGHT(0, 0x0000000000002000ULL)
126/* Allows for fchmod(2) and fchmodat(2). */
127#define	CAP_FCHMODAT		(CAP_FCHMOD | CAP_LOOKUP)
128/* Allows for fchown(2). */
129#define	CAP_FCHOWN		CAPRIGHT(0, 0x0000000000004000ULL)
130/* Allows for fchown(2) and fchownat(2). */
131#define	CAP_FCHOWNAT		(CAP_FCHOWN | CAP_LOOKUP)
132/* Allows for fcntl(2). */
133#define	CAP_FCNTL		CAPRIGHT(0, 0x0000000000008000ULL)
134/*
135 * Allows for flock(2), openat(O_SHLOCK), openat(O_EXLOCK),
136 * fcntl(F_SETLK_REMOTE), fcntl(F_SETLKW), fcntl(F_SETLK), fcntl(F_GETLK).
137 */
138#define	CAP_FLOCK		CAPRIGHT(0, 0x0000000000010000ULL)
139/* Allows for fpathconf(2). */
140#define	CAP_FPATHCONF		CAPRIGHT(0, 0x0000000000020000ULL)
141/* Allows for UFS background-fsck operations. */
142#define	CAP_FSCK		CAPRIGHT(0, 0x0000000000040000ULL)
143/* Allows for fstat(2). */
144#define	CAP_FSTAT		CAPRIGHT(0, 0x0000000000080000ULL)
145/* Allows for fstat(2), fstatat(2) and faccessat(2). */
146#define	CAP_FSTATAT		(CAP_FSTAT | CAP_LOOKUP)
147/* Allows for fstatfs(2). */
148#define	CAP_FSTATFS		CAPRIGHT(0, 0x0000000000100000ULL)
149/* Allows for futimens(2) and futimes(2). */
150#define	CAP_FUTIMES		CAPRIGHT(0, 0x0000000000200000ULL)
151/* Allows for futimens(2), futimes(2), futimesat(2) and utimensat(2). */
152#define	CAP_FUTIMESAT		(CAP_FUTIMES | CAP_LOOKUP)
153/* Allows for linkat(2) and renameat(2) (destination directory descriptor). */
154#define	CAP_LINKAT		(CAP_LOOKUP | 0x0000000000400000ULL)
155/* Allows for mkdirat(2). */
156#define	CAP_MKDIRAT		(CAP_LOOKUP | 0x0000000000800000ULL)
157/* Allows for mkfifoat(2). */
158#define	CAP_MKFIFOAT		(CAP_LOOKUP | 0x0000000001000000ULL)
159/* Allows for mknodat(2). */
160#define	CAP_MKNODAT		(CAP_LOOKUP | 0x0000000002000000ULL)
161/* Allows for renameat(2). */
162#define	CAP_RENAMEAT		(CAP_LOOKUP | 0x0000000004000000ULL)
163/* Allows for symlinkat(2). */
164#define	CAP_SYMLINKAT		(CAP_LOOKUP | 0x0000000008000000ULL)
165/*
166 * Allows for unlinkat(2) and renameat(2) if destination object exists and
167 * will be removed.
168 */
169#define	CAP_UNLINKAT		(CAP_LOOKUP | 0x0000000010000000ULL)
170
171/* Socket operations. */
172/* Allows for accept(2) and accept4(2). */
173#define	CAP_ACCEPT		CAPRIGHT(0, 0x0000000020000000ULL)
174/* Allows for bind(2). */
175#define	CAP_BIND		CAPRIGHT(0, 0x0000000040000000ULL)
176/* Allows for connect(2). */
177#define	CAP_CONNECT		CAPRIGHT(0, 0x0000000080000000ULL)
178/* Allows for getpeername(2). */
179#define	CAP_GETPEERNAME		CAPRIGHT(0, 0x0000000100000000ULL)
180/* Allows for getsockname(2). */
181#define	CAP_GETSOCKNAME		CAPRIGHT(0, 0x0000000200000000ULL)
182/* Allows for getsockopt(2). */
183#define	CAP_GETSOCKOPT		CAPRIGHT(0, 0x0000000400000000ULL)
184/* Allows for listen(2). */
185#define	CAP_LISTEN		CAPRIGHT(0, 0x0000000800000000ULL)
186/* Allows for sctp_peeloff(2). */
187#define	CAP_PEELOFF		CAPRIGHT(0, 0x0000001000000000ULL)
188#define	CAP_RECV		CAP_READ
189#define	CAP_SEND		CAP_WRITE
190/* Allows for setsockopt(2). */
191#define	CAP_SETSOCKOPT		CAPRIGHT(0, 0x0000002000000000ULL)
192/* Allows for shutdown(2). */
193#define	CAP_SHUTDOWN		CAPRIGHT(0, 0x0000004000000000ULL)
194
195/* Allows for bindat(2) on a directory descriptor. */
196#define	CAP_BINDAT		(CAP_LOOKUP | 0x0000008000000000ULL)
197/* Allows for connectat(2) on a directory descriptor. */
198#define	CAP_CONNECTAT		(CAP_LOOKUP | 0x0000010000000000ULL)
199
200#define	CAP_SOCK_CLIENT \
201	(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
202	 CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
203#define	CAP_SOCK_SERVER \
204	(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
205	 CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
206	 CAP_SETSOCKOPT | CAP_SHUTDOWN)
207
208/* All used bits for index 0. */
209#define	CAP_ALL0		CAPRIGHT(0, 0x0000007FFFFFFFFFULL)
210
211/* Available bits for index 0. */
212#define	CAP_UNUSED0_40		CAPRIGHT(0, 0x0000008000000000ULL)
213/* ... */
214#define	CAP_UNUSED0_57		CAPRIGHT(0, 0x0100000000000000ULL)
215
216/* INDEX 1 */
217
218/* Mandatory Access Control. */
219/* Allows for mac_get_fd(3). */
220#define	CAP_MAC_GET		CAPRIGHT(1, 0x0000000000000001ULL)
221/* Allows for mac_set_fd(3). */
222#define	CAP_MAC_SET		CAPRIGHT(1, 0x0000000000000002ULL)
223
224/* Methods on semaphores. */
225#define	CAP_SEM_GETVALUE	CAPRIGHT(1, 0x0000000000000004ULL)
226#define	CAP_SEM_POST		CAPRIGHT(1, 0x0000000000000008ULL)
227#define	CAP_SEM_WAIT		CAPRIGHT(1, 0x0000000000000010ULL)
228
229/* Allows select(2) and poll(2) on descriptor. */
230#define	CAP_EVENT		CAPRIGHT(1, 0x0000000000000020ULL)
231/* Allows for kevent(2) on kqueue descriptor with eventlist != NULL. */
232#define	CAP_KQUEUE_EVENT	CAPRIGHT(1, 0x0000000000000040ULL)
233
234/* Strange and powerful rights that should not be given lightly. */
235/* Allows for ioctl(2). */
236#define	CAP_IOCTL		CAPRIGHT(1, 0x0000000000000080ULL)
237#define	CAP_TTYHOOK		CAPRIGHT(1, 0x0000000000000100ULL)
238
239/* Process management via process descriptors. */
240/* Allows for pdgetpid(2). */
241#define	CAP_PDGETPID		CAPRIGHT(1, 0x0000000000000200ULL)
242/* Allows for pdwait4(2). */
243#define	CAP_PDWAIT		CAPRIGHT(1, 0x0000000000000400ULL)
244/* Allows for pdkill(2). */
245#define	CAP_PDKILL		CAPRIGHT(1, 0x0000000000000800ULL)
246
247/* Extended attributes. */
248/* Allows for extattr_delete_fd(2). */
249#define	CAP_EXTATTR_DELETE	CAPRIGHT(1, 0x0000000000001000ULL)
250/* Allows for extattr_get_fd(2). */
251#define	CAP_EXTATTR_GET		CAPRIGHT(1, 0x0000000000002000ULL)
252/* Allows for extattr_list_fd(2). */
253#define	CAP_EXTATTR_LIST	CAPRIGHT(1, 0x0000000000004000ULL)
254/* Allows for extattr_set_fd(2). */
255#define	CAP_EXTATTR_SET		CAPRIGHT(1, 0x0000000000008000ULL)
256
257/* Access Control Lists. */
258/* Allows for acl_valid_fd_np(3). */
259#define	CAP_ACL_CHECK		CAPRIGHT(1, 0x0000000000010000ULL)
260/* Allows for acl_delete_fd_np(3). */
261#define	CAP_ACL_DELETE		CAPRIGHT(1, 0x0000000000020000ULL)
262/* Allows for acl_get_fd(3) and acl_get_fd_np(3). */
263#define	CAP_ACL_GET		CAPRIGHT(1, 0x0000000000040000ULL)
264/* Allows for acl_set_fd(3) and acl_set_fd_np(3). */
265#define	CAP_ACL_SET		CAPRIGHT(1, 0x0000000000080000ULL)
266
267/* Allows for kevent(2) on kqueue descriptor with changelist != NULL. */
268#define	CAP_KQUEUE_CHANGE	CAPRIGHT(1, 0x0000000000100000ULL)
269
270#define	CAP_KQUEUE		(CAP_KQUEUE_EVENT | CAP_KQUEUE_CHANGE)
271
272/* All used bits for index 1. */
273#define	CAP_ALL1		CAPRIGHT(1, 0x00000000001FFFFFULL)
274
275/* Available bits for index 1. */
276#define	CAP_UNUSED1_22		CAPRIGHT(1, 0x0000000000200000ULL)
277/* ... */
278#define	CAP_UNUSED1_57		CAPRIGHT(1, 0x0100000000000000ULL)
279
280/* Backward compatibility. */
281#define	CAP_POLL_EVENT		CAP_EVENT
282
283#define	CAP_ALL(rights)		do {					\
284	(rights)->cr_rights[0] =					\
285	    ((uint64_t)CAP_RIGHTS_VERSION << 62) | CAP_ALL0;		\
286	(rights)->cr_rights[1] = CAP_ALL1;				\
287} while (0)
288
289#define	CAP_NONE(rights)	do {					\
290	(rights)->cr_rights[0] =					\
291	    ((uint64_t)CAP_RIGHTS_VERSION << 62) | CAPRIGHT(0, 0ULL);	\
292	(rights)->cr_rights[1] = CAPRIGHT(1, 0ULL);			\
293} while (0)
294
295#define	CAPRVER(right)		((int)((right) >> 62))
296#define	CAPVER(rights)		CAPRVER((rights)->cr_rights[0])
297#define	CAPARSIZE(rights)	(CAPVER(rights) + 2)
298#define	CAPIDXBIT(right)	((int)(((right) >> 57) & 0x1F))
299
300/*
301 * Allowed fcntl(2) commands.
302 */
303#define	CAP_FCNTL_GETFL		(1 << F_GETFL)
304#define	CAP_FCNTL_SETFL		(1 << F_SETFL)
305#if __BSD_VISIBLE || __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
306#define	CAP_FCNTL_GETOWN	(1 << F_GETOWN)
307#define	CAP_FCNTL_SETOWN	(1 << F_SETOWN)
308#endif
309#if __BSD_VISIBLE || __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
310#define	CAP_FCNTL_ALL		(CAP_FCNTL_GETFL | CAP_FCNTL_SETFL | \
311				 CAP_FCNTL_GETOWN | CAP_FCNTL_SETOWN)
312#else
313#define	CAP_FCNTL_ALL		(CAP_FCNTL_GETFL | CAP_FCNTL_SETFL)
314#endif
315
316#define	CAP_IOCTLS_ALL	SSIZE_MAX
317
318#define	cap_rights_init(...)						\
319	__cap_rights_init(CAP_RIGHTS_VERSION, __VA_ARGS__, 0ULL)
320cap_rights_t *__cap_rights_init(int version, cap_rights_t *rights, ...);
321
322#define	cap_rights_set(rights, ...)					\
323	__cap_rights_set((rights), __VA_ARGS__, 0ULL)
324cap_rights_t *__cap_rights_set(cap_rights_t *rights, ...);
325
326#define	cap_rights_clear(rights, ...)					\
327	__cap_rights_clear((rights), __VA_ARGS__, 0ULL)
328cap_rights_t *__cap_rights_clear(cap_rights_t *rights, ...);
329
330#define	cap_rights_is_set(rights, ...)					\
331	__cap_rights_is_set((rights), __VA_ARGS__, 0ULL)
332bool __cap_rights_is_set(const cap_rights_t *rights, ...);
333
334bool cap_rights_is_valid(const cap_rights_t *rights);
335cap_rights_t *cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
336cap_rights_t *cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
337bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
338
339#ifdef _KERNEL
340
341#include <sys/systm.h>
342
343#define IN_CAPABILITY_MODE(td) ((td->td_ucred->cr_flags & CRED_FLAG_CAPMODE) != 0)
344
345struct filedesc;
346struct filedescent;
347
348/*
349 * Test whether a capability grants the requested rights.
350 */
351int	cap_check(const cap_rights_t *havep, const cap_rights_t *needp);
352/*
353 * Convert capability rights into VM access flags.
354 */
355u_char	cap_rights_to_vmprot(cap_rights_t *havep);
356
357/*
358 * For the purposes of procstat(1) and similar tools, allow kern_descrip.c to
359 * extract the rights from a capability.
360 */
361cap_rights_t	*cap_rights_fde(struct filedescent *fde);
362cap_rights_t	*cap_rights(struct filedesc *fdp, int fd);
363
364int	cap_ioctl_check(struct filedesc *fdp, int fd, u_long cmd);
365int	cap_fcntl_check_fde(struct filedescent *fde, int cmd);
366int	cap_fcntl_check(struct filedesc *fdp, int fd, int cmd);
367
368#else /* !_KERNEL */
369
370__BEGIN_DECLS
371/*
372 * cap_enter(): Cause the process to enter capability mode, which will
373 * prevent it from directly accessing global namespaces.  System calls will
374 * be limited to process-local, process-inherited, or file descriptor
375 * operations.  If already in capability mode, a no-op.
376 */
377int	cap_enter(void);
378
379/*
380 * Are we sandboxed (in capability mode)?
381 * This is a libc wrapper around the cap_getmode(2) system call.
382 */
383bool	cap_sandboxed(void);
384
385/*
386 * cap_getmode(): Are we in capability mode?
387 */
388int	cap_getmode(u_int *modep);
389
390/*
391 * Limits capability rights for the given descriptor (CAP_*).
392 */
393int cap_rights_limit(int fd, const cap_rights_t *rights);
394/*
395 * Returns capability rights for the given descriptor.
396 */
397#define	cap_rights_get(fd, rights)	__cap_rights_get(CAP_RIGHTS_VERSION, (fd), (rights))
398int __cap_rights_get(int version, int fd, cap_rights_t *rightsp);
399/*
400 * Limits allowed ioctls for the given descriptor.
401 */
402int cap_ioctls_limit(int fd, const unsigned long *cmds, size_t ncmds);
403/*
404 * Returns array of allowed ioctls for the given descriptor.
405 * If all ioctls are allowed, the cmds array is not populated and
406 * the function returns CAP_IOCTLS_ALL.
407 */
408ssize_t cap_ioctls_get(int fd, unsigned long *cmds, size_t maxcmds);
409/*
410 * Limits allowed fcntls for the given descriptor (CAP_FCNTL_*).
411 */
412int cap_fcntls_limit(int fd, uint32_t fcntlrights);
413/*
414 * Returns bitmask of allowed fcntls for the given descriptor.
415 */
416int cap_fcntls_get(int fd, uint32_t *fcntlrightsp);
417
418__END_DECLS
419
420#endif /* !_KERNEL */
421
422#endif /* !_SYS_CAPSICUM_H_ */
423