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