/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2008-2010, 2015 Robert N. M. Watson * Copyright (c) 2012 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 software were developed 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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ /* * Definitions for FreeBSD capabilities facility. */ #ifndef _SYS_CAPSICUM_H_ #define _SYS_CAPSICUM_H_ #include #include #include #include #include #ifndef _KERNEL #include #endif #define CAPRIGHT(idx, bit) ((1ULL << (57 + (idx))) | (bit)) /* * Possible rights on capabilities. * * Notes: * Some system calls don't require a capability in order to perform an * operation on an fd. These include: close, dup, dup2. * * sendfile is authorized using CAP_READ on the file and CAP_WRITE on the * socket. * * mmap() and aio*() system calls will need special attention as they may * involve reads or writes depending a great deal on context. */ /* INDEX 0 */ /* * General file I/O. */ /* Allows for openat(O_RDONLY), read(2), readv(2). */ #define CAP_READ CAPRIGHT(0, 0x0000000000000001ULL) /* Allows for openat(O_WRONLY | O_APPEND), write(2), writev(2). */ #define CAP_WRITE CAPRIGHT(0, 0x0000000000000002ULL) /* Allows for lseek(fd, 0, SEEK_CUR). */ #define CAP_SEEK_TELL CAPRIGHT(0, 0x0000000000000004ULL) /* Allows for lseek(2). */ #define CAP_SEEK (CAP_SEEK_TELL | 0x0000000000000008ULL) /* Allows for aio_read(2), pread(2), preadv(2). */ #define CAP_PREAD (CAP_SEEK | CAP_READ) /* * Allows for aio_write(2), openat(O_WRONLY) (without O_APPEND), pwrite(2), * pwritev(2). */ #define CAP_PWRITE (CAP_SEEK | CAP_WRITE) /* Allows for mmap(PROT_NONE). */ #define CAP_MMAP CAPRIGHT(0, 0x0000000000000010ULL) /* Allows for mmap(PROT_READ). */ #define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ) /* Allows for mmap(PROT_WRITE). */ #define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE) /* Allows for mmap(PROT_EXEC). */ #define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000020ULL) /* Allows for mmap(PROT_READ | PROT_WRITE). */ #define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W) /* Allows for mmap(PROT_READ | PROT_EXEC). */ #define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X) /* Allows for mmap(PROT_WRITE | PROT_EXEC). */ #define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X) /* Allows for mmap(PROT_READ | PROT_WRITE | PROT_EXEC). */ #define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X) /* Allows for openat(O_CREAT). */ #define CAP_CREATE CAPRIGHT(0, 0x0000000000000040ULL) /* Allows for openat(O_EXEC) and fexecve(2) in turn. */ #define CAP_FEXECVE CAPRIGHT(0, 0x0000000000000080ULL) /* Allows for openat(O_SYNC), openat(O_FSYNC), fsync(2), aio_fsync(2). */ #define CAP_FSYNC CAPRIGHT(0, 0x0000000000000100ULL) /* Allows for openat(O_TRUNC), ftruncate(2). */ #define CAP_FTRUNCATE CAPRIGHT(0, 0x0000000000000200ULL) /* Lookups - used to constrain *at() calls. */ #define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL) /* VFS methods. */ /* Allows for fchdir(2). */ #define CAP_FCHDIR CAPRIGHT(0, 0x0000000000000800ULL) /* Allows for fchflags(2). */ #define CAP_FCHFLAGS CAPRIGHT(0, 0x0000000000001000ULL) /* Allows for fchflags(2) and chflagsat(2). */ #define CAP_CHFLAGSAT (CAP_FCHFLAGS | CAP_LOOKUP) /* Allows for fchmod(2). */ #define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL) /* Allows for fchmod(2) and fchmodat(2). */ #define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP) /* Allows for fchown(2). */ #define CAP_FCHOWN CAPRIGHT(0, 0x0000000000004000ULL) /* Allows for fchown(2) and fchownat(2). */ #define CAP_FCHOWNAT (CAP_FCHOWN | CAP_LOOKUP) /* Allows for fcntl(2). */ #define CAP_FCNTL CAPRIGHT(0, 0x0000000000008000ULL) /* * Allows for flock(2), openat(O_SHLOCK), openat(O_EXLOCK), * fcntl(F_SETLK_REMOTE), fcntl(F_SETLKW), fcntl(F_SETLK), fcntl(F_GETLK). */ #define CAP_FLOCK CAPRIGHT(0, 0x0000000000010000ULL) /* Allows for fpathconf(2). */ #define CAP_FPATHCONF CAPRIGHT(0, 0x0000000000020000ULL) /* Allows for UFS background-fsck operations. */ #define CAP_FSCK CAPRIGHT(0, 0x0000000000040000ULL) /* Allows for fstat(2). */ #define CAP_FSTAT CAPRIGHT(0, 0x0000000000080000ULL) /* Allows for fstat(2), fstatat(2) and faccessat(2). */ #define CAP_FSTATAT (CAP_FSTAT | CAP_LOOKUP) /* Allows for fstatfs(2). */ #define CAP_FSTATFS CAPRIGHT(0, 0x0000000000100000ULL) /* Allows for futimens(2) and futimes(2). */ #define CAP_FUTIMES CAPRIGHT(0, 0x0000000000200000ULL) /* Allows for futimens(2), futimes(2), futimesat(2) and utimensat(2). */ #define CAP_FUTIMESAT (CAP_FUTIMES | CAP_LOOKUP) /* Allows for linkat(2) (target directory descriptor). */ #define CAP_LINKAT_TARGET (CAP_LOOKUP | 0x0000000000400000ULL) /* Allows for mkdirat(2). */ #define CAP_MKDIRAT (CAP_LOOKUP | 0x0000000000800000ULL) /* Allows for mkfifoat(2). */ #define CAP_MKFIFOAT (CAP_LOOKUP | 0x0000000001000000ULL) /* Allows for mknodat(2). */ #define CAP_MKNODAT (CAP_LOOKUP | 0x0000000002000000ULL) /* Allows for renameat(2) (source directory descriptor). */ #define CAP_RENAMEAT_SOURCE (CAP_LOOKUP | 0x0000000004000000ULL) /* Allows for symlinkat(2). */ #define CAP_SYMLINKAT (CAP_LOOKUP | 0x0000000008000000ULL) /* * Allows for unlinkat(2) and renameat(2) if destination object exists and * will be removed. */ #define CAP_UNLINKAT (CAP_LOOKUP | 0x0000000010000000ULL) /* Socket operations. */ /* Allows for accept(2) and accept4(2). */ #define CAP_ACCEPT CAPRIGHT(0, 0x0000000020000000ULL) /* Allows for bind(2). */ #define CAP_BIND CAPRIGHT(0, 0x0000000040000000ULL) /* Allows for connect(2). */ #define CAP_CONNECT CAPRIGHT(0, 0x0000000080000000ULL) /* Allows for getpeername(2). */ #define CAP_GETPEERNAME CAPRIGHT(0, 0x0000000100000000ULL) /* Allows for getsockname(2). */ #define CAP_GETSOCKNAME CAPRIGHT(0, 0x0000000200000000ULL) /* Allows for getsockopt(2). */ #define CAP_GETSOCKOPT CAPRIGHT(0, 0x0000000400000000ULL) /* Allows for listen(2). */ #define CAP_LISTEN CAPRIGHT(0, 0x0000000800000000ULL) /* Allows for sctp_peeloff(2). */ #define CAP_PEELOFF CAPRIGHT(0, 0x0000001000000000ULL) #define CAP_RECV CAP_READ #define CAP_SEND CAP_WRITE /* Allows for setsockopt(2). */ #define CAP_SETSOCKOPT CAPRIGHT(0, 0x0000002000000000ULL) /* Allows for shutdown(2). */ #define CAP_SHUTDOWN CAPRIGHT(0, 0x0000004000000000ULL) /* Allows for bindat(2) on a directory descriptor. */ #define CAP_BINDAT (CAP_LOOKUP | 0x0000008000000000ULL) /* Allows for connectat(2) on a directory descriptor. */ #define CAP_CONNECTAT (CAP_LOOKUP | 0x0000010000000000ULL) /* Allows for linkat(2) (source directory descriptor). */ #define CAP_LINKAT_SOURCE (CAP_LOOKUP | 0x0000020000000000ULL) /* Allows for renameat(2) (target directory descriptor). */ #define CAP_RENAMEAT_TARGET (CAP_LOOKUP | 0x0000040000000000ULL) #define CAP_SOCK_CLIENT \ (CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \ CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN) #define CAP_SOCK_SERVER \ (CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \ CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \ CAP_SETSOCKOPT | CAP_SHUTDOWN) /* All used bits for index 0. */ #define CAP_ALL0 CAPRIGHT(0, 0x000007FFFFFFFFFFULL) /* Available bits for index 0. */ #define CAP_UNUSED0_44 CAPRIGHT(0, 0x0000080000000000ULL) /* ... */ #define CAP_UNUSED0_57 CAPRIGHT(0, 0x0100000000000000ULL) /* INDEX 1 */ /* Mandatory Access Control. */ /* Allows for mac_get_fd(3). */ #define CAP_MAC_GET CAPRIGHT(1, 0x0000000000000001ULL) /* Allows for mac_set_fd(3). */ #define CAP_MAC_SET CAPRIGHT(1, 0x0000000000000002ULL) /* Methods on semaphores. */ #define CAP_SEM_GETVALUE CAPRIGHT(1, 0x0000000000000004ULL) #define CAP_SEM_POST CAPRIGHT(1, 0x0000000000000008ULL) #define CAP_SEM_WAIT CAPRIGHT(1, 0x0000000000000010ULL) /* Allows select(2) and poll(2) on descriptor. */ #define CAP_EVENT CAPRIGHT(1, 0x0000000000000020ULL) /* Allows for kevent(2) on kqueue descriptor with eventlist != NULL. */ #define CAP_KQUEUE_EVENT CAPRIGHT(1, 0x0000000000000040ULL) /* Strange and powerful rights that should not be given lightly. */ /* Allows for ioctl(2). */ #define CAP_IOCTL CAPRIGHT(1, 0x0000000000000080ULL) #define CAP_TTYHOOK CAPRIGHT(1, 0x0000000000000100ULL) /* Process management via process descriptors. */ /* Allows for pdgetpid(2). */ #define CAP_PDGETPID CAPRIGHT(1, 0x0000000000000200ULL) /* * Allows for pdwait4(2). * * XXX: this constant was imported unused, but is targeted to be implemented * in the future (bug 235871). */ #define CAP_PDWAIT CAPRIGHT(1, 0x0000000000000400ULL) /* Allows for pdkill(2). */ #define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL) /* Extended attributes. */ /* Allows for extattr_delete_fd(2). */ #define CAP_EXTATTR_DELETE CAPRIGHT(1, 0x0000000000001000ULL) /* Allows for extattr_get_fd(2). */ #define CAP_EXTATTR_GET CAPRIGHT(1, 0x0000000000002000ULL) /* Allows for extattr_list_fd(2). */ #define CAP_EXTATTR_LIST CAPRIGHT(1, 0x0000000000004000ULL) /* Allows for extattr_set_fd(2). */ #define CAP_EXTATTR_SET CAPRIGHT(1, 0x0000000000008000ULL) /* Access Control Lists. */ /* Allows for acl_valid_fd_np(3). */ #define CAP_ACL_CHECK CAPRIGHT(1, 0x0000000000010000ULL) /* Allows for acl_delete_fd_np(3). */ #define CAP_ACL_DELETE CAPRIGHT(1, 0x0000000000020000ULL) /* Allows for acl_get_fd(3) and acl_get_fd_np(3). */ #define CAP_ACL_GET CAPRIGHT(1, 0x0000000000040000ULL) /* Allows for acl_set_fd(3) and acl_set_fd_np(3). */ #define CAP_ACL_SET CAPRIGHT(1, 0x0000000000080000ULL) /* Allows for kevent(2) on kqueue descriptor with changelist != NULL. */ #define CAP_KQUEUE_CHANGE CAPRIGHT(1, 0x0000000000100000ULL) #define CAP_KQUEUE (CAP_KQUEUE_EVENT | CAP_KQUEUE_CHANGE) /* All used bits for index 1. */ #define CAP_ALL1 CAPRIGHT(1, 0x00000000001FFFFFULL) /* Available bits for index 1. */ #define CAP_UNUSED1_22 CAPRIGHT(1, 0x0000000000200000ULL) /* ... */ #define CAP_UNUSED1_57 CAPRIGHT(1, 0x0100000000000000ULL) /* Backward compatibility. */ #define CAP_POLL_EVENT CAP_EVENT #define CAP_ALL(rights) do { \ (rights)->cr_rights[0] = \ ((uint64_t)CAP_RIGHTS_VERSION << 62) | CAP_ALL0; \ (rights)->cr_rights[1] = CAP_ALL1; \ } while (0) #define CAP_NONE(rights) do { \ (rights)->cr_rights[0] = \ ((uint64_t)CAP_RIGHTS_VERSION << 62) | CAPRIGHT(0, 0ULL); \ (rights)->cr_rights[1] = CAPRIGHT(1, 0ULL); \ } while (0) #define CAPRVER(right) ((int)((right) >> 62)) #define CAPVER(rights) CAPRVER((rights)->cr_rights[0]) #define CAPARSIZE(rights) (CAPVER(rights) + 2) #define CAPIDXBIT(right) ((int)(((right) >> 57) & 0x1F)) /* * Allowed fcntl(2) commands. */ #define CAP_FCNTL_GETFL (1 << F_GETFL) #define CAP_FCNTL_SETFL (1 << F_SETFL) #define CAP_FCNTL_GETOWN (1 << F_GETOWN) #define CAP_FCNTL_SETOWN (1 << F_SETOWN) #define CAP_FCNTL_ALL (CAP_FCNTL_GETFL | CAP_FCNTL_SETFL | \ CAP_FCNTL_GETOWN | CAP_FCNTL_SETOWN) #define CAP_IOCTLS_ALL SSIZE_MAX __BEGIN_DECLS #define cap_rights_init(...) \ __cap_rights_init(CAP_RIGHTS_VERSION, __VA_ARGS__, 0ULL) cap_rights_t *__cap_rights_init(int version, cap_rights_t *rights, ...); #define cap_rights_set(...) \ __cap_rights_set(__VA_ARGS__, 0ULL) cap_rights_t *__cap_rights_set(cap_rights_t *rights, ...); #define cap_rights_clear(...) \ __cap_rights_clear(__VA_ARGS__, 0ULL) cap_rights_t *__cap_rights_clear(cap_rights_t *rights, ...); #define cap_rights_is_set(...) \ __cap_rights_is_set(__VA_ARGS__, 0ULL) bool __cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_valid(const cap_rights_t *rights); cap_rights_t *cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); cap_rights_t *cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); #ifdef _KERNEL /* * We only support one size to reduce branching. */ _Static_assert(CAP_RIGHTS_VERSION == CAP_RIGHTS_VERSION_00, "unsupported version of capsicum rights"); #define cap_rights_init_zero(r) ({ \ cap_rights_t *_r = (r); \ CAP_NONE(_r); \ _r; \ }) #define cap_rights_init_one(r, right) ({ \ CTASSERT(CAPRVER(right) == CAP_RIGHTS_VERSION); \ cap_rights_t *_r = (r); \ CAP_NONE(_r); \ _r->cr_rights[CAPIDXBIT(right) - 1] |= right; \ _r; \ }) #define cap_rights_set_one(r, right) ({ \ CTASSERT(CAPRVER(right) == CAP_RIGHTS_VERSION); \ cap_rights_t *_r = (r); \ _r->cr_rights[CAPIDXBIT(right) - 1] |= right; \ _r; \ }) /* * Allow checking caps which are possibly getting modified at the same time. * The caller is expected to determine whether the result is legitimate via * other means, see fget_unlocked for an example. */ static inline bool cap_rights_contains_transient(const cap_rights_t *big, const cap_rights_t *little) { if (__predict_true( (big->cr_rights[0] & little->cr_rights[0]) == little->cr_rights[0] && (big->cr_rights[1] & little->cr_rights[1]) == little->cr_rights[1])) return (true); return (false); } #define cap_rights_contains cap_rights_contains_transient int cap_check_failed_notcapable(const cap_rights_t *havep, const cap_rights_t *needp); static inline int cap_check_inline(const cap_rights_t *havep, const cap_rights_t *needp) { if (__predict_false(!cap_rights_contains(havep, needp))) return (cap_check_failed_notcapable(havep, needp)); return (0); } static inline int cap_check_inline_transient(const cap_rights_t *havep, const cap_rights_t *needp) { if (__predict_false(!cap_rights_contains(havep, needp))) return (1); return (0); } #else bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little); #endif __END_DECLS #ifdef _KERNEL #include #define IN_CAPABILITY_MODE(td) (((td)->td_ucred->cr_flags & CRED_FLAG_CAPMODE) != 0) struct filedesc; struct filedescent; /* * Test whether a capability grants the requested rights. */ int cap_check(const cap_rights_t *havep, const cap_rights_t *needp); /* * Convert capability rights into VM access flags. */ vm_prot_t cap_rights_to_vmprot(const cap_rights_t *havep); /* * For the purposes of procstat(1) and similar tools, allow kern_descrip.c to * extract the rights from a capability. * * Dereferencing fdep requires filedesc.h, but including it would cause * significant pollution. Instead add a macro for consumers which want it, * most notably kern_descrip.c. */ #define cap_rights_fde_inline(fdep) (&(fdep)->fde_rights) const cap_rights_t *cap_rights_fde(const struct filedescent *fde); const cap_rights_t *cap_rights(struct filedesc *fdp, int fd); int cap_ioctl_check(struct filedesc *fdp, int fd, u_long cmd); int cap_fcntl_check_fde(struct filedescent *fde, int cmd); int cap_fcntl_check(struct filedesc *fdp, int fd, int cmd); extern bool trap_enotcap; #else /* !_KERNEL */ __BEGIN_DECLS /* * cap_enter(): Cause the process to enter capability mode, which will * prevent it from directly accessing global namespaces. System calls will * be limited to process-local, process-inherited, or file descriptor * operations. If already in capability mode, a no-op. */ int cap_enter(void); /* * Are we sandboxed (in capability mode)? * This is a libc wrapper around the cap_getmode(2) system call. */ bool cap_sandboxed(void); /* * cap_getmode(): Are we in capability mode? */ int cap_getmode(u_int *modep); /* * Limits capability rights for the given descriptor (CAP_*). */ int cap_rights_limit(int fd, const cap_rights_t *rights); /* * Returns capability rights for the given descriptor. */ #define cap_rights_get(fd, rights) \ __cap_rights_get(CAP_RIGHTS_VERSION, (fd), (rights)) int __cap_rights_get(int version, int fd, cap_rights_t *rights); /* * Limits allowed ioctls for the given descriptor. */ int cap_ioctls_limit(int fd, const cap_ioctl_t *cmds, size_t ncmds); /* * Returns array of allowed ioctls for the given descriptor. * If all ioctls are allowed, the cmds array is not populated and * the function returns CAP_IOCTLS_ALL. */ ssize_t cap_ioctls_get(int fd, cap_ioctl_t *cmds, size_t maxcmds); /* * Limits allowed fcntls for the given descriptor (CAP_FCNTL_*). */ int cap_fcntls_limit(int fd, uint32_t fcntlrights); /* * Returns bitmask of allowed fcntls for the given descriptor. */ int cap_fcntls_get(int fd, uint32_t *fcntlrightsp); __END_DECLS #endif /* !_KERNEL */ #endif /* !_SYS_CAPSICUM_H_ */