[mirror_lxc.git] / src / lxc / mount_utils.h

/* SPDX-License-Identifier: LGPL-2.1+ */

#ifndef __LXC_MOUNT_UTILS_H
#define __LXC_MOUNT_UTILS_H

#include "config.h"

#include <linux/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mount.h>

#include "compiler.h"
#include "memory_utils.h"
#include "syscall_wrappers.h"

struct lxc_rootfs;

/* open_tree() flags */

#ifndef AT_RECURSIVE
#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
#endif

#ifndef OPEN_TREE_CLONE
#define OPEN_TREE_CLONE 1
#endif

#ifndef OPEN_TREE_CLOEXEC
#define OPEN_TREE_CLOEXEC O_CLOEXEC
#endif

/* move_mount() flags */
#ifndef MOVE_MOUNT_F_SYMLINKS
#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
#endif

#ifndef MOVE_MOUNT_F_AUTOMOUNTS
#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
#endif

#ifndef MOVE_MOUNT_F_EMPTY_PATH
#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
#endif

#ifndef MOVE_MOUNT_T_SYMLINKS
#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
#endif

#ifndef MOVE_MOUNT_T_AUTOMOUNTS
#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
#endif

#ifndef MOVE_MOUNT_T_EMPTY_PATH
#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
#endif

#ifndef MOVE_MOUNT__MASK
#define MOVE_MOUNT__MASK 0x00000077
#endif

/* fsopen() flags */
#ifndef FSOPEN_CLOEXEC
#define FSOPEN_CLOEXEC 0x00000001
#endif

/* fspick() flags */
#ifndef FSPICK_CLOEXEC
#define FSPICK_CLOEXEC 0x00000001
#endif

#ifndef FSPICK_SYMLINK_NOFOLLOW
#define FSPICK_SYMLINK_NOFOLLOW 0x00000002
#endif

#ifndef FSPICK_NO_AUTOMOUNT
#define FSPICK_NO_AUTOMOUNT 0x00000004
#endif

#ifndef FSPICK_EMPTY_PATH
#define FSPICK_EMPTY_PATH 0x00000008
#endif

/* fsconfig() commands */
#ifndef FSCONFIG_SET_FLAG
#define FSCONFIG_SET_FLAG 0 /* Set parameter, supplying no value */
#endif

#ifndef FSCONFIG_SET_STRING
#define FSCONFIG_SET_STRING 1 /* Set parameter, supplying a string value */
#endif

#ifndef FSCONFIG_SET_BINARY
#define FSCONFIG_SET_BINARY 2 /* Set parameter, supplying a binary blob value */
#endif

#ifndef FSCONFIG_SET_PATH
#define FSCONFIG_SET_PATH 3 /* Set parameter, supplying an object by path */
#endif

#ifndef FSCONFIG_SET_PATH_EMPTY
#define FSCONFIG_SET_PATH_EMPTY 4 /* Set parameter, supplying an object by (empty) path */
#endif

#ifndef FSCONFIG_SET_FD
#define FSCONFIG_SET_FD 5 /* Set parameter, supplying an object by fd */
#endif

#ifndef FSCONFIG_CMD_CREATE
#define FSCONFIG_CMD_CREATE 6 /* Invoke superblock creation */
#endif

#ifndef FSCONFIG_CMD_RECONFIGURE
#define	FSCONFIG_CMD_RECONFIGURE 7	/* Invoke superblock reconfiguration */
#endif

/* fsmount() flags */
#ifndef FSMOUNT_CLOEXEC
#define FSMOUNT_CLOEXEC 0x00000001
#endif

/* mount attributes */
#ifndef MOUNT_ATTR_RDONLY
#define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only */
#endif

#ifndef MOUNT_ATTR_NOSUID
#define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits */
#endif

#ifndef MOUNT_ATTR_NODEV
#define MOUNT_ATTR_NODEV 0x00000004 /* Disallow access to device special files */
#endif

#ifndef MOUNT_ATTR_NOEXEC
#define MOUNT_ATTR_NOEXEC 0x00000008 /* Disallow program execution */
#endif

#ifndef MOUNT_ATTR__ATIME
#define MOUNT_ATTR__ATIME 0x00000070 /* Setting on how atime should be updated */
#endif

#ifndef MOUNT_ATTR_RELATIME
#define MOUNT_ATTR_RELATIME 0x00000000 /* - Update atime relative to mtime/ctime. */
#endif

#ifndef MOUNT_ATTR_NOATIME
#define MOUNT_ATTR_NOATIME 0x00000010 /* - Do not update access times. */
#endif

#ifndef MOUNT_ATTR_STRICTATIME
#define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */
#endif

#ifndef MOUNT_ATTR_NODIRATIME
#define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times */
#endif

#ifndef MOUNT_ATTR_IDMAP
#define MOUNT_ATTR_IDMAP 0x00100000
#endif

__hidden extern int mnt_attributes_new(unsigned int old_flags, unsigned int *new_flags);

__hidden extern int mnt_attributes_old(unsigned int new_flags, unsigned int *old_flags);

__hidden extern int fs_prepare(const char *fs_name, int dfd_from,
			       const char *path_from, __u64 o_flags_from,
			       __u64 resolve_flags_from);
__hidden extern int fs_set_property(int fd_fs, const char *key, const char *val);
__hidden extern int fs_set_flag(int fd_fs, const char *key);
__hidden extern int fs_attach(int fd_fs, int dfd_to, const char *path_to,
			      __u64 o_flags_to, __u64 resolve_flags_to,
			      unsigned int attr_flags);

static inline int fs_mount(const char *fs_name, int dfd_from,
			   const char *path_from, __u64 o_flags_from,
			   __u64 resolve_flags_from, int dfd_to,
			   const char *path_to, __u64 o_flags_to,
			   __u64 resolve_flags_to,
			   unsigned int attr_flags)
{
	__do_close int fd_fs = -EBADF;

	fd_fs = fs_prepare(fs_name, dfd_from, path_from, o_flags_from, resolve_flags_from);
	if (fd_fs < 0)
		return -errno;
	return fs_attach(fd_fs, dfd_to, path_to, o_flags_to, resolve_flags_to, attr_flags);
}

__hidden extern int __fd_bind_mount(int dfd_from, const char *path_from,
				    __u64 o_flags_from,
				    __u64 resolve_flags_from, int dfd_to,
				    const char *path_to, __u64 o_flags_to,
				    __u64 resolve_flags_to, __u64 attr_set,
				    __u64 attr_clr, __u64 propagation,
				    int userns_fd, bool recursive);
static inline int fd_mount_idmapped(int dfd_from, const char *path_from,
				    __u64 o_flags_from,
				    __u64 resolve_flags_from, int dfd_to,
				    const char *path_to, __u64 o_flags_to,
				    __u64 resolve_flags_to, __u64 attr_set,
				    __u64 attr_clr, __u64 propagation,
				    int userns_fd, bool recursive)
{
	return __fd_bind_mount(dfd_from, path_from, o_flags_from,
			       resolve_flags_from, dfd_to, path_to, o_flags_to,
			       resolve_flags_to, attr_set, attr_clr,
			       propagation, userns_fd, recursive);
}

static inline int fd_bind_mount(int dfd_from, const char *path_from,
				__u64 o_flags_from, __u64 resolve_flags_from,
				int dfd_to, const char *path_to,
				__u64 o_flags_to, __u64 resolve_flags_to,
				__u64 attr_set, __u64 attr_clr,
				__u64 propagation, bool recursive)
{
	return __fd_bind_mount(dfd_from, path_from, o_flags_from, resolve_flags_from,
			       dfd_to, path_to, o_flags_to, resolve_flags_to,
			       attr_set, attr_clr, propagation, -EBADF, recursive);
}
__hidden extern int create_detached_idmapped_mount(const char *path,
						   int userns_fd, bool recursive,
						   __u64 attr_set, __u64 attr_clr);
__hidden extern int move_detached_mount(int dfd_from, int dfd_to,
					const char *path_to, __u64 o_flags_to,
					__u64 resolve_flags_to);

__hidden extern int calc_remount_flags_new(int dfd_from, const char *path_from,
					   __u64 o_flags_from,
					   __u64 resolve_flags_from,
					   bool remount, unsigned long cur_flags,
					   unsigned int *new_flags);

__hidden extern int calc_remount_flags_old(int dfd_from, const char *path_from,
					   __u64 o_flags_from,
					   __u64 resolve_flags_from,
					   bool remount, unsigned long cur_flags,
					   unsigned int *old_flags);

__hidden extern unsigned long add_required_remount_flags(const char *s,
							 const char *d,
							 unsigned long flags);

__hidden extern bool can_use_mount_api(void);
__hidden extern bool can_use_bind_mounts(void);
__hidden extern int mount_at(int dfd_from, const char *path_from,
			     __u64 resolve_flags_from, int dfd_to,
			     const char *path_to, __u64 resolve_flags_to,
			     const char *fs_name, unsigned int flags,
			     const void *data);
static inline int mount_fd(int fd_from, int fd_to, const char *fs_name,
			   unsigned int flags, const void *data)
{
	return mount_at(fd_from, "", 0, fd_to, "", 0, fs_name, flags, data);
}

#endif /* __LXC_MOUNT_UTILS_H */
Commit	Line	Data
7f88a1a2 CB	1	/* SPDX-License-Identifier: LGPL-2.1+ */
	2
	3	#ifndef __LXC_MOUNT_UTILS_H
	4	#define __LXC_MOUNT_UTILS_H
	5
1160ce89 CB	6	#include "config.h"
1160ce89 CB	7
74ed30d7	8	#include <linux/types.h>
7f88a1a2 CB	9	#include <stdio.h>
	10	#include <stdlib.h>
	11	#include <sys/mount.h>
	12
	13	#include "compiler.h"
1f3eb959	14	#include "memory_utils.h"
87545854	15	#include "syscall_wrappers.h"
7f88a1a2	16
c146c54e CB	17	struct lxc_rootfs;
c146c54e CB	18
7f88a1a2	19	/* open_tree() flags */
041d1e30 CB	20
	21	#ifndef AT_RECURSIVE
	22	#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
	23	#endif
	24
7f88a1a2 CB	25	#ifndef OPEN_TREE_CLONE
	26	#define OPEN_TREE_CLONE 1
	27	#endif
	28
	29	#ifndef OPEN_TREE_CLOEXEC
	30	#define OPEN_TREE_CLOEXEC O_CLOEXEC
	31	#endif
	32
	33	/* move_mount() flags */
	34	#ifndef MOVE_MOUNT_F_SYMLINKS
	35	#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
	36	#endif
	37
	38	#ifndef MOVE_MOUNT_F_AUTOMOUNTS
	39	#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
	40	#endif
	41
	42	#ifndef MOVE_MOUNT_F_EMPTY_PATH
	43	#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
	44	#endif
	45
	46	#ifndef MOVE_MOUNT_T_SYMLINKS
	47	#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
	48	#endif
	49
	50	#ifndef MOVE_MOUNT_T_AUTOMOUNTS
	51	#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
	52	#endif
	53
	54	#ifndef MOVE_MOUNT_T_EMPTY_PATH
	55	#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
	56	#endif
	57
	58	#ifndef MOVE_MOUNT__MASK
	59	#define MOVE_MOUNT__MASK 0x00000077
	60	#endif
	61
	62	/* fsopen() flags */
	63	#ifndef FSOPEN_CLOEXEC
	64	#define FSOPEN_CLOEXEC 0x00000001
	65	#endif
	66
	67	/* fspick() flags */
	68	#ifndef FSPICK_CLOEXEC
	69	#define FSPICK_CLOEXEC 0x00000001
	70	#endif
	71
	72	#ifndef FSPICK_SYMLINK_NOFOLLOW
	73	#define FSPICK_SYMLINK_NOFOLLOW 0x00000002
	74	#endif
	75
	76	#ifndef FSPICK_NO_AUTOMOUNT
	77	#define FSPICK_NO_AUTOMOUNT 0x00000004
	78	#endif
	79
	80	#ifndef FSPICK_EMPTY_PATH
	81	#define FSPICK_EMPTY_PATH 0x00000008
	82	#endif
	83
	84	/* fsconfig() commands */
	85	#ifndef FSCONFIG_SET_FLAG
	86	#define FSCONFIG_SET_FLAG 0 /* Set parameter, supplying no value */
	87	#endif
	88
89	#ifndef FSCONFIG_SET_STRING
90	#define FSCONFIG_SET_STRING 1 /* Set parameter, supplying a string value */
91	#endif
92
93	#ifndef FSCONFIG_SET_BINARY
94	#define FSCONFIG_SET_BINARY 2 /* Set parameter, supplying a binary blob value */
95	#endif
96
97	#ifndef FSCONFIG_SET_PATH
98	#define FSCONFIG_SET_PATH 3 /* Set parameter, supplying an object by path */
99	#endif
100
101	#ifndef FSCONFIG_SET_PATH_EMPTY
102	#define FSCONFIG_SET_PATH_EMPTY 4 /* Set parameter, supplying an object by (empty) path */
103	#endif
104
105	#ifndef FSCONFIG_SET_FD
106	#define FSCONFIG_SET_FD 5 /* Set parameter, supplying an object by fd */
107	#endif
108
109	#ifndef FSCONFIG_CMD_CREATE
110	#define FSCONFIG_CMD_CREATE 6 /* Invoke superblock creation */
111	#endif
112
113	#ifndef FSCONFIG_CMD_RECONFIGURE
114	#define FSCONFIG_CMD_RECONFIGURE 7 /* Invoke superblock reconfiguration */
115	#endif
116
117	/* fsmount() flags */
118	#ifndef FSMOUNT_CLOEXEC
119	#define FSMOUNT_CLOEXEC 0x00000001
120	#endif
121
122	/* mount attributes */
123	#ifndef MOUNT_ATTR_RDONLY
124	#define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only */
125	#endif
126
127	#ifndef MOUNT_ATTR_NOSUID
128	#define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits */
129	#endif
130
131	#ifndef MOUNT_ATTR_NODEV
132	#define MOUNT_ATTR_NODEV 0x00000004 /* Disallow access to device special files */
133	#endif
134
135	#ifndef MOUNT_ATTR_NOEXEC
136	#define MOUNT_ATTR_NOEXEC 0x00000008 /* Disallow program execution */
137	#endif
138
139	#ifndef MOUNT_ATTR__ATIME
140	#define MOUNT_ATTR__ATIME 0x00000070 /* Setting on how atime should be updated */
141	#endif
142
143	#ifndef MOUNT_ATTR_RELATIME
144	#define MOUNT_ATTR_RELATIME 0x00000000 /* - Update atime relative to mtime/ctime. */
145	#endif
146
147	#ifndef MOUNT_ATTR_NOATIME
148	#define MOUNT_ATTR_NOATIME 0x00000010 /* - Do not update access times. */
149	#endif
150
151	#ifndef MOUNT_ATTR_STRICTATIME
152	#define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */
153	#endif
154
155	#ifndef MOUNT_ATTR_NODIRATIME
156	#define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times */
157	#endif
158
031e0285 CB	159	#ifndef MOUNT_ATTR_IDMAP
	160	#define MOUNT_ATTR_IDMAP 0x00100000
	161	#endif
	162
7f88a1a2 CB	163	__hidden extern int mnt_attributes_new(unsigned int old_flags, unsigned int *new_flags);
	164
	165	__hidden extern int mnt_attributes_old(unsigned int new_flags, unsigned int *old_flags);
	166
1f3eb959 CB	167	__hidden extern int fs_prepare(const char *fs_name, int dfd_from,
	168	const char *path_from, __u64 o_flags_from,
	169	__u64 resolve_flags_from);
	170	__hidden extern int fs_set_property(int fd_fs, const char key, const char val);
289b707b	171	__hidden extern int fs_set_flag(int fd_fs, const char *key);
1f3eb959 CB	172	__hidden extern int fs_attach(int fd_fs, int dfd_to, const char *path_to,
	173	__u64 o_flags_to, __u64 resolve_flags_to,
	174	unsigned int attr_flags);
	175
	176	static inline int fs_mount(const char *fs_name, int dfd_from,
	177	const char *path_from, __u64 o_flags_from,
	178	__u64 resolve_flags_from, int dfd_to,
	179	const char *path_to, __u64 o_flags_to,
	180	__u64 resolve_flags_to,
	181	unsigned int attr_flags)
	182	{
	183	__do_close int fd_fs = -EBADF;
	184
	185	fd_fs = fs_prepare(fs_name, dfd_from, path_from, o_flags_from, resolve_flags_from);
	186	if (fd_fs < 0)
	187	return -errno;
	188	return fs_attach(fd_fs, dfd_to, path_to, o_flags_to, resolve_flags_to, attr_flags);
	189	}
74ed30d7	190
8cf6a646 CB	191	__hidden extern int __fd_bind_mount(int dfd_from, const char *path_from,
	192	__u64 o_flags_from,
	193	__u64 resolve_flags_from, int dfd_to,
	194	const char *path_to, __u64 o_flags_to,
704cadd5 CB	195	__u64 resolve_flags_to, __u64 attr_set,
704cadd5 CB	196	__u64 attr_clr, __u64 propagation,
8cf6a646 CB	197	int userns_fd, bool recursive);
	198	static inline int fd_mount_idmapped(int dfd_from, const char *path_from,
	199	__u64 o_flags_from,
	200	__u64 resolve_flags_from, int dfd_to,
	201	const char *path_to, __u64 o_flags_to,
704cadd5 CB	202	__u64 resolve_flags_to, __u64 attr_set,
704cadd5 CB	203	__u64 attr_clr, __u64 propagation,
8cf6a646 CB	204	int userns_fd, bool recursive)
8cf6a646 CB	205	{
704cadd5 CB	206	return __fd_bind_mount(dfd_from, path_from, o_flags_from,
	207	resolve_flags_from, dfd_to, path_to, o_flags_to,
	208	resolve_flags_to, attr_set, attr_clr,
	209	propagation, userns_fd, recursive);
8cf6a646 CB	210	}
	211
	212	static inline int fd_bind_mount(int dfd_from, const char *path_from,
	213	__u64 o_flags_from, __u64 resolve_flags_from,
	214	int dfd_to, const char *path_to,
	215	__u64 o_flags_to, __u64 resolve_flags_to,
704cadd5 CB	216	__u64 attr_set, __u64 attr_clr,
704cadd5 CB	217	__u64 propagation, bool recursive)
8cf6a646 CB	218	{
	219	return __fd_bind_mount(dfd_from, path_from, o_flags_from, resolve_flags_from,
	220	dfd_to, path_to, o_flags_to, resolve_flags_to,
704cadd5	221	attr_set, attr_clr, propagation, -EBADF, recursive);
8cf6a646	222	}
d347d356	223	__hidden extern int create_detached_idmapped_mount(const char *path,
704cadd5 CB	224	int userns_fd, bool recursive,
704cadd5 CB	225	__u64 attr_set, __u64 attr_clr);
d347d356 CB	226	__hidden extern int move_detached_mount(int dfd_from, int dfd_to,
	227	const char *path_to, __u64 o_flags_to,
	228	__u64 resolve_flags_to);
e26cf563	229
ac11febd CB	230	__hidden extern int calc_remount_flags_new(int dfd_from, const char *path_from,
	231	__u64 o_flags_from,
	232	__u64 resolve_flags_from,
	233	bool remount, unsigned long cur_flags,
	234	unsigned int *new_flags);
	235
	236	__hidden extern int calc_remount_flags_old(int dfd_from, const char *path_from,
	237	__u64 o_flags_from,
	238	__u64 resolve_flags_from,
	239	bool remount, unsigned long cur_flags,
	240	unsigned int *old_flags);
	241
	242	__hidden extern unsigned long add_required_remount_flags(const char *s,
	243	const char *d,
	244	unsigned long flags);
	245
de7f9f33	246	__hidden extern bool can_use_mount_api(void);
d4e07569	247	__hidden extern bool can_use_bind_mounts(void);
8b0ccdaa CB	248	__hidden extern int mount_at(int dfd_from, const char *path_from,
	249	__u64 resolve_flags_from, int dfd_to,
	250	const char *path_to, __u64 resolve_flags_to,
	251	const char *fs_name, unsigned int flags,
	252	const void *data);
	253	static inline int mount_fd(int fd_from, int fd_to, const char *fs_name,
	254	unsigned int flags, const void *data)
	255	{
	256	return mount_at(fd_from, "", 0, fd_to, "", 0, fs_name, flags, data);
	257	}
de7f9f33	258
7f88a1a2	259	#endif /* __LXC_MOUNT_UTILS_H */