15263807472

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

#include "bitfield.h"
#include "chattr-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "log.h"
#include "string-util.h"

int chattr_full(
              int dir_fd,
              const char *path,
              unsigned value,
              unsigned mask,
              unsigned *ret_previous,
              unsigned *ret_final,
              ChattrApplyFlags flags) {

        _cleanup_close_ int fd = -EBADF;
        unsigned old_attr, new_attr;
        int set_flags_errno = 0;
        struct stat st;

        assert(dir_fd >= 0 || dir_fd == AT_FDCWD);

        fd = xopenat(dir_fd, path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
        if (fd < 0)
                return fd;

        if (fstat(fd, &st) < 0)
                return -errno;

        /* Explicitly check whether this is a regular file or directory. If it is anything else (such
         * as a device node or fifo), then the ioctl will not hit the file systems but possibly
         * drivers, where the ioctl might have different effects. Notably, DRM is using the same
         * ioctl() number. */

        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
                return -ENOTTY;

        if (mask == 0 && !ret_previous && !ret_final)
                return 0;

        if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)
                return -errno;

        new_attr = (old_attr & ~mask) | (value & mask);
        if (new_attr == old_attr) {
                if (ret_previous)
                        *ret_previous = old_attr;
                if (ret_final)
                        *ret_final = old_attr;
                return 0;
        }

        if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) >= 0) {
                unsigned attr;

                /* Some filesystems (BTRFS) silently fail when a flag cannot be set. Let's make sure our
                 * changes actually went through by querying the flags again and verifying they're equal to
                 * the flags we tried to configure. */

                if (ioctl(fd, FS_IOC_GETFLAGS, &attr) < 0)
                        return -errno;

                if (new_attr == attr) {
                        if (ret_previous)
                                *ret_previous = old_attr;
                        if (ret_final)
                                *ret_final = new_attr;
                        return 1;
                }

                /* Trigger the fallback logic. */
                errno = EINVAL;
        }

        if (!ERRNO_IS_IOCTL_NOT_SUPPORTED(errno) || !FLAGS_SET(flags, CHATTR_FALLBACK_BITWISE))
                return -errno;

        /* When -EINVAL is returned, incompatible attributes might be simultaneously specified. E.g.,
         * compress(c) and nocow(C) attributes cannot be set to files on btrfs. As a fallback, let's try to
         * set attributes one by one.
         *
         * Alternatively, when we get EINVAL or EOPNOTSUPP (or a similar error code) we assume a flag might
         * just not be supported, and we can ignore it too */

        unsigned current_attr = old_attr;

        BIT_FOREACH(i, mask) {
                unsigned new_one, mask_one = 1u << i;

                new_one = UPDATE_FLAG(current_attr, mask_one, FLAGS_SET(value, mask_one));
                if (new_one == current_attr)
                        continue;

                if (ioctl(fd, FS_IOC_SETFLAGS, &new_one) < 0) {
                        if (!ERRNO_IS_IOCTL_NOT_SUPPORTED(errno))
                                return -errno;

                        log_full_errno(FLAGS_SET(flags, CHATTR_WARN_UNSUPPORTED_FLAGS) ? LOG_WARNING : LOG_DEBUG,
                                       errno,
                                       "Unable to set file attribute 0x%x on %s, ignoring: %m", mask_one, strna(path));

                        /* Ensures that we record whether only EOPNOTSUPP&friends are encountered, or if a more serious
                         * error (thus worth logging at a different level, etc) was seen too. */
                        if (set_flags_errno == 0 || !ERRNO_IS_IOCTL_NOT_SUPPORTED(errno))
                                set_flags_errno = -errno;

                        continue;
                }

                if (ioctl(fd, FS_IOC_GETFLAGS, &current_attr) < 0)
                        return -errno;
        }

        if (ret_previous)
                *ret_previous = old_attr;
        if (ret_final)
                *ret_final = current_attr;

        /* -ENOANO indicates that some attributes cannot be set. ERRNO_IS_IOCTL_NOT_SUPPORTED indicates that
         * all encountered failures were due to flags not supported by the FS, so return a specific error in
         * that case, so callers can handle it properly (e.g.: tmpfiles.d can use debug level logging). */
        return current_attr == new_attr ? 1 : ERRNO_IS_IOCTL_NOT_SUPPORTED(set_flags_errno) ? set_flags_errno : -ENOANO;
}

int read_attr_fd(int fd, unsigned *ret) {
        struct stat st;

        assert(fd >= 0);
        assert(ret);

        if (fstat(fd, &st) < 0)
                return -errno;

        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
                return -ENOTTY;

        _cleanup_close_ int fd_close = -EBADF;
        fd = fd_reopen_condition(fd, O_RDONLY|O_CLOEXEC|O_NOCTTY, O_PATH, &fd_close); /* drop O_PATH if it is set */
        if (fd < 0)
                return fd;

        return RET_NERRNO(ioctl(fd, FS_IOC_GETFLAGS, ret));
}

int read_attr_at(int dir_fd, const char *path, unsigned *ret) {
        _cleanup_close_ int fd_close = -EBADF;
        int fd;

        assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
        assert(ret);

        if (isempty(path) && dir_fd != AT_FDCWD)
                fd = dir_fd;
        else {
                fd_close = xopenat(dir_fd, path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
                if (fd_close < 0)
                        return fd_close;

                fd = fd_close;
        }

        return read_attr_fd(fd, ret);
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <fcntl.h>
4	#include <sys/ioctl.h>
5	#include <sys/stat.h>
6
7	#include "bitfield.h"
8	#include "chattr-util.h"
9	#include "errno-util.h"
10	#include "fd-util.h"
11	#include "fs-util.h"
12	#include "log.h"
13	#include "string-util.h"
14
15	int chattr_full(	1,078✔
16	int dir_fd,
17	const char *path,
18	unsigned value,
19	unsigned mask,
20	unsigned *ret_previous,
21	unsigned *ret_final,
22	ChattrApplyFlags flags) {
23
24	_cleanup_close_ int fd = -EBADF;	1,078✔
25	unsigned old_attr, new_attr;	1,078✔
26	int set_flags_errno = 0;	1,078✔
27	struct stat st;	1,078✔
28
29	assert(dir_fd >= 0 \|\| dir_fd == AT_FDCWD);	1,078✔
30
31	fd = xopenat(dir_fd, path, O_RDONLY\|O_CLOEXEC\|O_NOCTTY\|O_NOFOLLOW);	1,078✔
32	if (fd < 0)	1,078✔
33	return fd;
34
35	if (fstat(fd, &st) < 0)	1,071✔
UNCOV 36	return -errno;	×
37
38	/* Explicitly check whether this is a regular file or directory. If it is anything else (such
39	* as a device node or fifo), then the ioctl will not hit the file systems but possibly
40	* drivers, where the ioctl might have different effects. Notably, DRM is using the same
41	* ioctl() number. */
42
43	if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))	1,071✔
44	return -ENOTTY;
45
46	if (mask == 0 && !ret_previous && !ret_final)	1,071✔
47	return 0;
48
49	if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)	1,071✔
UNCOV 50	return -errno;	×
51
52	new_attr = (old_attr & ~mask) \| (value & mask);	1,071✔
53	if (new_attr == old_attr) {	1,071✔
54	if (ret_previous)	124✔
UNCOV 55	*ret_previous = old_attr;	×
56	if (ret_final)	124✔
57	*ret_final = old_attr;	×
58	return 0;	124✔
59	}
60
61	if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) >= 0) {	947✔
62	unsigned attr;	17✔
63
64	/* Some filesystems (BTRFS) silently fail when a flag cannot be set. Let's make sure our
65	* changes actually went through by querying the flags again and verifying they're equal to
66	* the flags we tried to configure. */
67
68	if (ioctl(fd, FS_IOC_GETFLAGS, &attr) < 0)	17✔
69	return -errno;	17✔
70
71	if (new_attr == attr) {	17✔
72	if (ret_previous)	17✔
73	*ret_previous = old_attr;	2✔
74	if (ret_final)	17✔
UNCOV 75	*ret_final = new_attr;	×
76	return 1;	17✔
77	}
78
79	/* Trigger the fallback logic. */
UNCOV 80	errno = EINVAL;	×
81	}
82
83	if (!ERRNO_IS_IOCTL_NOT_SUPPORTED(errno) \|\| !FLAGS_SET(flags, CHATTR_FALLBACK_BITWISE))	930✔
84	return -errno;	875✔
85
86	/* When -EINVAL is returned, incompatible attributes might be simultaneously specified. E.g.,
87	* compress(c) and nocow(C) attributes cannot be set to files on btrfs. As a fallback, let's try to
88	* set attributes one by one.
89	*
90	* Alternatively, when we get EINVAL or EOPNOTSUPP (or a similar error code) we assume a flag might
91	* just not be supported, and we can ignore it too */
92
93	unsigned current_attr = old_attr;	55✔
94
95	BIT_FOREACH(i, mask) {	137✔
96	unsigned new_one, mask_one = 1u << i;	82✔
97
98	new_one = UPDATE_FLAG(current_attr, mask_one, FLAGS_SET(value, mask_one));	82✔
99	if (new_one == current_attr)	82✔
100	continue;	57✔
101
102	if (ioctl(fd, FS_IOC_SETFLAGS, &new_one) < 0) {	82✔
103	if (!ERRNO_IS_IOCTL_NOT_SUPPORTED(errno))	57✔
UNCOV 104	return -errno;	×
105
106	log_full_errno(FLAGS_SET(flags, CHATTR_WARN_UNSUPPORTED_FLAGS) ? LOG_WARNING : LOG_DEBUG,	112✔
107	errno,
108	"Unable to set file attribute 0x%x on %s, ignoring: %m", mask_one, strna(path));
109
110	/* Ensures that we record whether only EOPNOTSUPP&friends are encountered, or if a more serious
111	* error (thus worth logging at a different level, etc) was seen too. */
112	if (set_flags_errno == 0 \|\| !ERRNO_IS_IOCTL_NOT_SUPPORTED(errno))	57✔
113	set_flags_errno = -errno;	55✔
114
115	continue;	57✔
116	}
117
118	if (ioctl(fd, FS_IOC_GETFLAGS, &current_attr) < 0)	25✔
UNCOV 119	return -errno;	×
120	}
121
122	if (ret_previous)	55✔
123	*ret_previous = old_attr;	46✔
124	if (ret_final)	55✔
125	*ret_final = current_attr;	46✔
126
127	/* -ENOANO indicates that some attributes cannot be set. ERRNO_IS_IOCTL_NOT_SUPPORTED indicates that
128	* all encountered failures were due to flags not supported by the FS, so return a specific error in
129	* that case, so callers can handle it properly (e.g.: tmpfiles.d can use debug level logging). */
130	return current_attr == new_attr ? 1 : ERRNO_IS_IOCTL_NOT_SUPPORTED(set_flags_errno) ? set_flags_errno : -ENOANO;	55✔
131	}
132
133	int read_attr_fd(int fd, unsigned *ret) {	401,934✔
134	struct stat st;	401,934✔
135
136	assert(fd >= 0);	401,934✔
137	assert(ret);	401,934✔
138
139	if (fstat(fd, &st) < 0)	401,934✔
UNCOV 140	return -errno;	×
141
142	if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))	401,934✔
143	return -ENOTTY;
144
145	_cleanup_close_ int fd_close = -EBADF;	401,934✔
146	fd = fd_reopen_condition(fd, O_RDONLY\|O_CLOEXEC\|O_NOCTTY, O_PATH, &fd_close); /* drop O_PATH if it is set */	401,928✔
147	if (fd < 0)	401,928✔
148	return fd;
149
150	return RET_NERRNO(ioctl(fd, FS_IOC_GETFLAGS, ret));	599,743✔
151	}
152
153	int read_attr_at(int dir_fd, const char path, unsigned ret) {	398,119✔
154	_cleanup_close_ int fd_close = -EBADF;	398,119✔
155	int fd;	398,119✔
156
157	assert(dir_fd >= 0 \|\| dir_fd == AT_FDCWD);	398,119✔
158	assert(ret);	398,119✔
159
160	if (isempty(path) && dir_fd != AT_FDCWD)	398,119✔
161	fd = dir_fd;
162	else {
163	fd_close = xopenat(dir_fd, path, O_RDONLY\|O_CLOEXEC\|O_NOCTTY\|O_NOFOLLOW);	1,574✔
164	if (fd_close < 0)	1,574✔
165	return fd_close;
166
167	fd = fd_close;
168	}
169
170	return read_attr_fd(fd, ret);	397,880✔
171	}

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