15263807472

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

#include <fcntl.h>
#include <sys/statvfs.h>
#include <unistd.h>

#include "alloc-util.h"
#include "chase.h"
#include "dirent-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "filesystems.h"
#include "fs-util.h"
#include "hash-funcs.h"
#include "log.h"
#include "missing_magic.h"
#include "mountpoint-util.h"
#include "path-util.h"
#include "siphash24.h"
#include "stat-util.h"
#include "string-util.h"
#include "time-util.h"

static int verify_stat_at(
                int fd,
                const char *path,
                bool follow,
                int (*verify_func)(const struct stat *st),
                bool verify) {

        struct stat st;
        int r;

        assert(fd >= 0 || fd == AT_FDCWD);
        assert(!isempty(path) || !follow);
        assert(verify_func);

        if (fstatat(fd, strempty(path), &st,
                    (isempty(path) ? AT_EMPTY_PATH : 0) | (follow ? 0 : AT_SYMLINK_NOFOLLOW)) < 0)
                return -errno;

        r = verify_func(&st);
        return verify ? r : r >= 0;
}

int stat_verify_regular(const struct stat *st) {
        assert(st);

        /* Checks whether the specified stat() structure refers to a regular file. If not returns an
         * appropriate error code. */

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (!S_ISREG(st->st_mode))
                return -EBADFD;

        return 0;
}

int verify_regular_at(int fd, const char *path, bool follow) {
        return verify_stat_at(fd, path, follow, stat_verify_regular, true);
}

int fd_verify_regular(int fd) {
        assert(fd >= 0);
        return verify_regular_at(fd, NULL, false);
}

int stat_verify_directory(const struct stat *st) {
        assert(st);

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (!S_ISDIR(st->st_mode))
                return -ENOTDIR;

        return 0;
}

int fd_verify_directory(int fd) {
        assert(fd >= 0);
        return verify_stat_at(fd, NULL, false, stat_verify_directory, true);
}

int is_dir_at(int fd, const char *path, bool follow) {
        return verify_stat_at(fd, path, follow, stat_verify_directory, false);
}

int is_dir(const char *path, bool follow) {
        assert(!isempty(path));
        return is_dir_at(AT_FDCWD, path, follow);
}

int stat_verify_symlink(const struct stat *st) {
        assert(st);

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (!S_ISLNK(st->st_mode))
                return -ENOLINK;

        return 0;
}

int is_symlink(const char *path) {
        assert(!isempty(path));
        return verify_stat_at(AT_FDCWD, path, false, stat_verify_symlink, false);
}

int stat_verify_linked(const struct stat *st) {
        assert(st);

        if (st->st_nlink <= 0)
                return -EIDRM; /* recognizable error. */

        return 0;
}

int fd_verify_linked(int fd) {
        assert(fd >= 0);
        return verify_stat_at(fd, NULL, false, stat_verify_linked, true);
}

int stat_verify_device_node(const struct stat *st) {
        assert(st);

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (!S_ISBLK(st->st_mode) && !S_ISCHR(st->st_mode))
                return -ENOTTY;

        return 0;
}

int is_device_node(const char *path) {
        assert(!isempty(path));
        return verify_stat_at(AT_FDCWD, path, false, stat_verify_device_node, false);
}

int dir_is_empty_at(int dir_fd, const char *path, bool ignore_hidden_or_backup) {
        _cleanup_close_ int fd = -EBADF;
        struct dirent *buf;
        size_t m;

        fd = xopenat(dir_fd, path, O_DIRECTORY|O_CLOEXEC);
        if (fd < 0)
                return fd;

        /* Allocate space for at least 3 full dirents, since every dir has at least two entries ("."  +
         * ".."), and only once we have seen if there's a third we know whether the dir is empty or not. If
         * 'ignore_hidden_or_backup' is true we'll allocate a bit more, since we might skip over a bunch of
         * entries that we end up ignoring. */
        m = (ignore_hidden_or_backup ? 16 : 3) * DIRENT_SIZE_MAX;
        buf = alloca(m);

        for (;;) {
                struct dirent *de;
                ssize_t n;

                n = posix_getdents(fd, buf, m, /* flags = */ 0);
                if (n < 0)
                        return -errno;
                if (n == 0)
                        break;

                assert((size_t) n <= m);
                msan_unpoison(buf, n);

                FOREACH_DIRENT_IN_BUFFER(de, buf, n)
                        if (!(ignore_hidden_or_backup ? hidden_or_backup_file(de->d_name) : dot_or_dot_dot(de->d_name)))
                                return 0;
        }

        return 1;
}

bool null_or_empty(struct stat *st) {
        assert(st);

        if (S_ISREG(st->st_mode) && st->st_size <= 0)
                return true;

        /* We don't want to hardcode the major/minor of /dev/null, hence we do a simpler "is this a character
         * device node?" check. */

        if (S_ISCHR(st->st_mode))
                return true;

        return false;
}

int null_or_empty_path_with_root(const char *fn, const char *root) {
        struct stat st;
        int r;

        assert(fn);

        /* A symlink to /dev/null or an empty file?
         * When looking under root_dir, we can't expect /dev/ to be mounted,
         * so let's see if the path is a (possibly dangling) symlink to /dev/null. */

        if (path_equal(path_startswith(fn, root ?: "/"), "dev/null"))
                return true;

        r = chase_and_stat(fn, root, CHASE_PREFIX_ROOT, NULL, &st);
        if (r < 0)
                return r;

        return null_or_empty(&st);
}

int fd_is_read_only_fs(int fd) {
        struct statvfs st;

        assert(fd >= 0);

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

        if (st.f_flag & ST_RDONLY)
                return true;

        /* On NFS, fstatvfs() might not reflect whether we can actually write to the remote share. Let's try
         * again with access(W_OK) which is more reliable, at least sometimes. */
        if (access_fd(fd, W_OK) == -EROFS)
                return true;

        return false;
}

int path_is_read_only_fs(const char *path) {
        _cleanup_close_ int fd = -EBADF;

        assert(path);

        fd = open(path, O_CLOEXEC | O_PATH);
        if (fd < 0)
                return -errno;

        return fd_is_read_only_fs(fd);
}

int inode_same_at(int fda, const char *filea, int fdb, const char *fileb, int flags) {
        struct stat sta, stb;
        int r;

        assert(fda >= 0 || fda == AT_FDCWD);
        assert(fdb >= 0 || fdb == AT_FDCWD);
        assert((flags & ~(AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT)) == 0);

        /* Refuse an unset filea or fileb early unless AT_EMPTY_PATH is set */
        if ((isempty(filea) || isempty(fileb)) && !FLAGS_SET(flags, AT_EMPTY_PATH))
                return -EINVAL;

        /* Shortcut: comparing the same fd with itself means we can return true */
        if (fda >= 0 && fda == fdb && isempty(filea) && isempty(fileb) && FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW))
                return true;

        _cleanup_close_ int pin_a = -EBADF, pin_b = -EBADF;
        if (!FLAGS_SET(flags, AT_NO_AUTOMOUNT)) {
                /* Let's try to use the name_to_handle_at() AT_HANDLE_FID API to identify identical
                 * inodes. We have to issue multiple calls on the same file for that (first, to acquire the
                 * FID, and then to check if .st_dev is actually the same). Hence let's pin the inode in
                 * between via O_PATH, unless we already have an fd for it. */

                if (!isempty(filea)) {
                        pin_a = openat(fda, filea, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));
                        if (pin_a < 0)
                                return -errno;

                        fda = pin_a;
                        filea = NULL;
                        flags |= AT_EMPTY_PATH;
                }

                if (!isempty(fileb)) {
                        pin_b = openat(fdb, fileb, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));
                        if (pin_b < 0)
                                return -errno;

                        fdb = pin_b;
                        fileb = NULL;
                        flags |= AT_EMPTY_PATH;
                }

                int ntha_flags = at_flags_normalize_follow(flags) & (AT_EMPTY_PATH|AT_SYMLINK_FOLLOW);
                _cleanup_free_ struct file_handle *ha = NULL, *hb = NULL;
                int mntida = -1, mntidb = -1;

                r = name_to_handle_at_try_fid(
                                fda,
                                filea,
                                &ha,
                                &mntida,
                                ntha_flags);
                if (r < 0) {
                        if (is_name_to_handle_at_fatal_error(r))
                                return r;

                        goto fallback;
                }

                r = name_to_handle_at_try_fid(
                                fdb,
                                fileb,
                                &hb,
                                &mntidb,
                                ntha_flags);
                if (r < 0) {
                        if (is_name_to_handle_at_fatal_error(r))
                                return r;

                        goto fallback;
                }

                /* Now compare the two file handles */
                if (!file_handle_equal(ha, hb))
                        return false;

                /* If the file handles are the same and they come from the same mount ID? Great, then we are
                 * good, they are definitely the same */
                if (mntida == mntidb)
                        return true;

                /* File handles are the same, they are not on the same mount id. This might either be because
                 * they are on two entirely different file systems, that just happen to have the same FIDs
                 * (because they originally where created off the same disk images), or it could be because
                 * they are located on two distinct bind mounts of the same fs. To check that, let's look at
                 * .st_rdev of the inode. We simply reuse the fallback codepath for that, since it checks
                 * exactly that (it checks slightly more, but we don't care.) */
        }

fallback:
        if (fstatat(fda, strempty(filea), &sta, flags) < 0)
                return log_debug_errno(errno, "Cannot stat %s: %m", strna(filea));

        if (fstatat(fdb, strempty(fileb), &stb, flags) < 0)
                return log_debug_errno(errno, "Cannot stat %s: %m", strna(fileb));

        return stat_inode_same(&sta, &stb);
}

bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
        assert(s);
        assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));

        return F_TYPE_EQUAL(s->f_type, magic_value);
}

int is_fs_type_at(int dir_fd, const char *path, statfs_f_type_t magic_value) {
        struct statfs s;
        int r;

        r = xstatfsat(dir_fd, path, &s);
        if (r < 0)
                return r;

        return is_fs_type(&s, magic_value);
}

bool is_temporary_fs(const struct statfs *s) {
        return fs_in_group(s, FILESYSTEM_SET_TEMPORARY);
}

bool is_network_fs(const struct statfs *s) {
        return fs_in_group(s, FILESYSTEM_SET_NETWORK);
}

int fd_is_temporary_fs(int fd) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_temporary_fs(&s);
}

int fd_is_network_fs(int fd) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_network_fs(&s);
}

int path_is_temporary_fs(const char *path) {
        struct statfs s;

        if (statfs(path, &s) < 0)
                return -errno;

        return is_temporary_fs(&s);
}

int path_is_network_fs(const char *path) {
        struct statfs s;

        if (statfs(path, &s) < 0)
                return -errno;

        return is_network_fs(&s);
}

int proc_mounted(void) {
        int r;

        /* A quick check of procfs is properly mounted */

        r = path_is_fs_type("/proc/", PROC_SUPER_MAGIC);
        if (r == -ENOENT) /* not mounted at all */
                return false;

        return r;
}

bool stat_inode_same(const struct stat *a, const struct stat *b) {

        /* Returns if the specified stat structure references the same (though possibly modified) inode. Does
         * a thorough check, comparing inode nr, backing device and if the inode is still of the same type. */

        return stat_is_set(a) && stat_is_set(b) &&
                ((a->st_mode ^ b->st_mode) & S_IFMT) == 0 &&  /* same inode type */
                a->st_dev == b->st_dev &&
                a->st_ino == b->st_ino;
}

bool stat_inode_unmodified(const struct stat *a, const struct stat *b) {

        /* Returns if the specified stat structures reference the same, unmodified inode. This check tries to
         * be reasonably careful when detecting changes: we check both inode and mtime, to cater for file
         * systems where mtimes are fixed to 0 (think: ostree/nixos type installations). We also check file
         * size, backing device, inode type and if this refers to a device not the major/minor.
         *
         * Note that we don't care if file attributes such as ownership or access mode change, this here is
         * about contents of the file. The purpose here is to detect file contents changes, and nothing
         * else. */

        return stat_inode_same(a, b) &&
                a->st_mtim.tv_sec == b->st_mtim.tv_sec &&
                a->st_mtim.tv_nsec == b->st_mtim.tv_nsec &&
                (!S_ISREG(a->st_mode) || a->st_size == b->st_size) && /* if regular file, compare file size */
                (!(S_ISCHR(a->st_mode) || S_ISBLK(a->st_mode)) || a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */
}

bool statx_inode_same(const struct statx *a, const struct statx *b) {

        /* Same as stat_inode_same() but for struct statx */

        return statx_is_set(a) && statx_is_set(b) &&
                FLAGS_SET(a->stx_mask, STATX_TYPE|STATX_INO) && FLAGS_SET(b->stx_mask, STATX_TYPE|STATX_INO) &&
                ((a->stx_mode ^ b->stx_mode) & S_IFMT) == 0 &&
                a->stx_dev_major == b->stx_dev_major &&
                a->stx_dev_minor == b->stx_dev_minor &&
                a->stx_ino == b->stx_ino;
}

bool statx_mount_same(const struct statx *a, const struct statx *b) {
        if (!statx_is_set(a) || !statx_is_set(b))
                return false;

        /* if we have the mount ID, that's all we need */
        if (FLAGS_SET(a->stx_mask, STATX_MNT_ID) && FLAGS_SET(b->stx_mask, STATX_MNT_ID))
                return a->stx_mnt_id == b->stx_mnt_id;

        /* Otherwise, major/minor of backing device must match */
        return a->stx_dev_major == b->stx_dev_major &&
                a->stx_dev_minor == b->stx_dev_minor;
}

int xstatfsat(int dir_fd, const char *path, struct statfs *ret) {
        _cleanup_close_ int fd = -EBADF;

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

        if (!isempty(path)) {
                fd = xopenat(dir_fd, path, O_PATH|O_CLOEXEC|O_NOCTTY);
                if (fd < 0)
                        return fd;
                dir_fd = fd;
        }

        return RET_NERRNO(fstatfs(dir_fd, ret));
}

usec_t statx_timestamp_load(const struct statx_timestamp *ts) {
        return timespec_load(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });
}
nsec_t statx_timestamp_load_nsec(const struct statx_timestamp *ts) {
        return timespec_load_nsec(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });
}

void inode_hash_func(const struct stat *q, struct siphash *state) {
        siphash24_compress_typesafe(q->st_dev, state);
        siphash24_compress_typesafe(q->st_ino, state);
}

int inode_compare_func(const struct stat *a, const struct stat *b) {
        int r;

        r = CMP(a->st_dev, b->st_dev);
        if (r != 0)
                return r;

        return CMP(a->st_ino, b->st_ino);
}

DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(inode_hash_ops, struct stat, inode_hash_func, inode_compare_func, free);

const char* inode_type_to_string(mode_t m) {

        /* Returns a short string for the inode type. We use the same name as the underlying macros for each
         * inode type. */

        switch (m & S_IFMT) {
        case S_IFREG:
                return "reg";
        case S_IFDIR:
                return "dir";
        case S_IFLNK:
                return "lnk";
        case S_IFCHR:
                return "chr";
        case S_IFBLK:
                return "blk";
        case S_IFIFO:
                return "fifo";
        case S_IFSOCK:
                return "sock";
        }

        /* Note anonymous inodes in the kernel will have a zero type. Hence fstat() of an eventfd() will
         * return an .st_mode where we'll return NULL here! */
        return NULL;
}

mode_t inode_type_from_string(const char *s) {
        if (!s)
                return MODE_INVALID;

        if (streq(s, "reg"))
                return S_IFREG;
        if (streq(s, "dir"))
                return S_IFDIR;
        if (streq(s, "lnk"))
                return S_IFLNK;
        if (streq(s, "chr"))
                return S_IFCHR;
        if (streq(s, "blk"))
                return S_IFBLK;
        if (streq(s, "fifo"))
                return S_IFIFO;
        if (streq(s, "sock"))
                return S_IFSOCK;

        return MODE_INVALID;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <fcntl.h>
4	#include <sys/statvfs.h>
5	#include <unistd.h>
6
7	#include "alloc-util.h"
8	#include "chase.h"
9	#include "dirent-util.h"
10	#include "errno-util.h"
11	#include "fd-util.h"
12	#include "filesystems.h"
13	#include "fs-util.h"
14	#include "hash-funcs.h"
15	#include "log.h"
16	#include "missing_magic.h"
17	#include "mountpoint-util.h"
18	#include "path-util.h"
19	#include "siphash24.h"
20	#include "stat-util.h"
21	#include "string-util.h"
22	#include "time-util.h"
23
24	static int verify_stat_at(	2,181,995✔
25	int fd,
26	const char *path,
27	bool follow,
28	int (verify_func)(const struct stat st),
29	bool verify) {
30
31	struct stat st;	2,181,995✔
32	int r;	2,181,995✔
33
34	assert(fd >= 0 \|\| fd == AT_FDCWD);	2,181,995✔
35	assert(!isempty(path) \|\| !follow);	2,181,995✔
36	assert(verify_func);	2,181,995✔
37
38	if (fstatat(fd, strempty(path), &st,	5,189,411✔
39	(isempty(path) ? AT_EMPTY_PATH : 0) \| (follow ? 0 : AT_SYMLINK_NOFOLLOW)) < 0)	2,181,995✔
40	return -errno;	7,721✔
41
42	r = verify_func(&st);	2,174,274✔
43	return verify ? r : r >= 0;	2,174,274✔
44	}
45
46	int stat_verify_regular(const struct stat *st) {	2,659,355✔
47	assert(st);	2,659,355✔
48
49	/* Checks whether the specified stat() structure refers to a regular file. If not returns an
50	* appropriate error code. */
51
52	if (S_ISDIR(st->st_mode))	2,659,355✔
53	return -EISDIR;
54
55	if (S_ISLNK(st->st_mode))	2,657,167✔
56	return -ELOOP;
57
58	if (!S_ISREG(st->st_mode))	2,657,153✔
59	return -EBADFD;	17✔
60
61	return 0;
62	}
63
64	int verify_regular_at(int fd, const char *path, bool follow) {	825,666✔
65	return verify_stat_at(fd, path, follow, stat_verify_regular, true);	825,666✔
66	}
67
68	int fd_verify_regular(int fd) {	825,401✔
69	assert(fd >= 0);	825,401✔
70	return verify_regular_at(fd, NULL, false);	825,401✔
71	}
72
73	int stat_verify_directory(const struct stat *st) {	1,375,553✔
74	assert(st);	1,375,553✔
75
76	if (S_ISLNK(st->st_mode))	1,375,553✔
77	return -ELOOP;
78
79	if (!S_ISDIR(st->st_mode))	1,375,543✔
80	return -ENOTDIR;	8✔
81
82	return 0;
83	}
84
85	int fd_verify_directory(int fd) {	17✔
86	assert(fd >= 0);	17✔
87	return verify_stat_at(fd, NULL, false, stat_verify_directory, true);	17✔
88	}
89
90	int is_dir_at(int fd, const char *path, bool follow) {	1,340,595✔
91	return verify_stat_at(fd, path, follow, stat_verify_directory, false);	1,340,595✔
92	}
93
94	int is_dir(const char *path, bool follow) {	499,782✔
95	assert(!isempty(path));	499,782✔
96	return is_dir_at(AT_FDCWD, path, follow);	499,782✔
97	}
98
99	int stat_verify_symlink(const struct stat *st) {	15,602✔
100	assert(st);	15,602✔
101
102	if (S_ISDIR(st->st_mode))	15,602✔
103	return -EISDIR;
104
105	if (!S_ISLNK(st->st_mode))	15,587✔
106	return -ENOLINK;	428✔
107
108	return 0;
109	}
110
111	int is_symlink(const char *path) {	15,602✔
112	assert(!isempty(path));	15,602✔
113	return verify_stat_at(AT_FDCWD, path, false, stat_verify_symlink, false);	15,602✔
114	}
115
116	int stat_verify_linked(const struct stat *st) {	1,804,987✔
117	assert(st);	1,804,987✔
118
119	if (st->st_nlink <= 0)	1,804,987✔
120	return -EIDRM; /* recognizable error. */	2✔
121
122	return 0;
123	}
124
125	int fd_verify_linked(int fd) {	3✔
126	assert(fd >= 0);	3✔
127	return verify_stat_at(fd, NULL, false, stat_verify_linked, true);	3✔
128	}
129
130	int stat_verify_device_node(const struct stat *st) {	4,599✔
131	assert(st);	4,599✔
132
133	if (S_ISLNK(st->st_mode))	4,599✔
134	return -ELOOP;
135
136	if (S_ISDIR(st->st_mode))	4,599✔
137	return -EISDIR;
138
139	if (!S_ISBLK(st->st_mode) && !S_ISCHR(st->st_mode))	4,495✔
140	return -ENOTTY;	5✔
141
142	return 0;
143	}
144
145	int is_device_node(const char *path) {	112✔
146	assert(!isempty(path));	112✔
147	return verify_stat_at(AT_FDCWD, path, false, stat_verify_device_node, false);	112✔
148	}
149
150	int dir_is_empty_at(int dir_fd, const char *path, bool ignore_hidden_or_backup) {	36,786✔
151	_cleanup_close_ int fd = -EBADF;	36,786✔
152	struct dirent *buf;	36,786✔
153	size_t m;	36,786✔
154
155	fd = xopenat(dir_fd, path, O_DIRECTORY\|O_CLOEXEC);	36,786✔
156	if (fd < 0)	36,786✔
157	return fd;
158
159	/* Allocate space for at least 3 full dirents, since every dir has at least two entries ("." +
160	* ".."), and only once we have seen if there's a third we know whether the dir is empty or not. If
161	* 'ignore_hidden_or_backup' is true we'll allocate a bit more, since we might skip over a bunch of
162	* entries that we end up ignoring. */
163	m = (ignore_hidden_or_backup ? 16 : 3) * DIRENT_SIZE_MAX;	2,179✔
164	buf = alloca(m);	2,179✔
165
166	for (;;) {	3,500✔
167	struct dirent *de;	3,500✔
168	ssize_t n;	3,500✔
169
170	n = posix_getdents(fd, buf, m, /* flags = */ 0);	3,500✔
171	if (n < 0)	3,500✔
UNCOV 172	return -errno;	×
173	if (n == 0)	3,500✔
174	break;
175
176	assert((size_t) n <= m);	2,179✔
177	msan_unpoison(buf, n);	2,179✔
178
179	FOREACH_DIRENT_IN_BUFFER(de, buf, n)	5,763✔
180	if (!(ignore_hidden_or_backup ? hidden_or_backup_file(de->d_name) : dot_or_dot_dot(de->d_name)))	4,442✔
181	return 0;
182	}
183
184	return 1;
185	}
186
187	bool null_or_empty(struct stat *st) {	387,225✔
188	assert(st);	387,225✔
189
190	if (S_ISREG(st->st_mode) && st->st_size <= 0)	387,225✔
191	return true;
192
193	/* We don't want to hardcode the major/minor of /dev/null, hence we do a simpler "is this a character
194	* device node?" check. */
195
196	if (S_ISCHR(st->st_mode))	387,213✔
197	return true;	1,029✔
198
199	return false;
200	}
201
202	int null_or_empty_path_with_root(const char fn, const char root) {	294,040✔
203	struct stat st;	294,040✔
204	int r;	294,040✔
205
206	assert(fn);	294,040✔
207
208	/* A symlink to /dev/null or an empty file?
209	* When looking under root_dir, we can't expect /dev/ to be mounted,
210	* so let's see if the path is a (possibly dangling) symlink to /dev/null. */
211
212	if (path_equal(path_startswith(fn, root ?: "/"), "dev/null"))	588,080✔
213	return true;	294,040✔
214
215	r = chase_and_stat(fn, root, CHASE_PREFIX_ROOT, NULL, &st);	293,878✔
216	if (r < 0)	293,878✔
217	return r;
218
219	return null_or_empty(&st);	293,765✔
220	}
221
222	int fd_is_read_only_fs(int fd) {	1,766✔
223	struct statvfs st;	1,766✔
224
225	assert(fd >= 0);	1,766✔
226
227	if (fstatvfs(fd, &st) < 0)	1,766✔
UNCOV 228	return -errno;	×
229
230	if (st.f_flag & ST_RDONLY)	1,766✔
231	return true;
232
233	/* On NFS, fstatvfs() might not reflect whether we can actually write to the remote share. Let's try
234	* again with access(W_OK) which is more reliable, at least sometimes. */
235	if (access_fd(fd, W_OK) == -EROFS)	1,398✔
UNCOV 236	return true;	×
237
238	return false;
239	}
240
241	int path_is_read_only_fs(const char *path) {	1,493✔
242	_cleanup_close_ int fd = -EBADF;	1,493✔
243
244	assert(path);	1,493✔
245
246	fd = open(path, O_CLOEXEC \| O_PATH);	1,493✔
247	if (fd < 0)	1,493✔
248	return -errno;	146✔
249
250	return fd_is_read_only_fs(fd);	1,347✔
251	}
252
253	int inode_same_at(int fda, const char filea, int fdb, const char fileb, int flags) {	14,271✔
254	struct stat sta, stb;	14,271✔
255	int r;	14,271✔
256
257	assert(fda >= 0 \|\| fda == AT_FDCWD);	14,271✔
258	assert(fdb >= 0 \|\| fdb == AT_FDCWD);	14,271✔
259	assert((flags & ~(AT_EMPTY_PATH\|AT_SYMLINK_NOFOLLOW\|AT_NO_AUTOMOUNT)) == 0);	14,271✔
260
261	/* Refuse an unset filea or fileb early unless AT_EMPTY_PATH is set */
262	if ((isempty(filea) \|\| isempty(fileb)) && !FLAGS_SET(flags, AT_EMPTY_PATH))	28,313✔
263	return -EINVAL;	14,271✔
264
265	/* Shortcut: comparing the same fd with itself means we can return true */
266	if (fda >= 0 && fda == fdb && isempty(filea) && isempty(fileb) && FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW))	14,273✔
267	return true;
268
269	_cleanup_close_ int pin_a = -EBADF, pin_b = -EBADF;	28,541✔
270	if (!FLAGS_SET(flags, AT_NO_AUTOMOUNT)) {	14,270✔
271	/* Let's try to use the name_to_handle_at() AT_HANDLE_FID API to identify identical
272	* inodes. We have to issue multiple calls on the same file for that (first, to acquire the
273	* FID, and then to check if .st_dev is actually the same). Hence let's pin the inode in
274	* between via O_PATH, unless we already have an fd for it. */
275
276	if (!isempty(filea)) {	14,270✔
277	pin_a = openat(fda, filea, O_PATH\|O_CLOEXEC\|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));	14,042✔
278	if (pin_a < 0)	14,042✔
279	return -errno;	14,166✔
280
281	fda = pin_a;	13,539✔
282	filea = NULL;	13,539✔
283	flags \|= AT_EMPTY_PATH;	13,539✔
284	}
285
286	if (!isempty(fileb)) {	13,767✔
287	pin_b = openat(fdb, fileb, O_PATH\|O_CLOEXEC\|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));	13,537✔
288	if (pin_b < 0)	13,537✔
289	return -errno;	4✔
290
291	fdb = pin_b;	13,533✔
292	fileb = NULL;	13,533✔
293	flags \|= AT_EMPTY_PATH;	13,533✔
294	}
295
296	int ntha_flags = at_flags_normalize_follow(flags) & (AT_EMPTY_PATH\|AT_SYMLINK_FOLLOW);	13,763✔
297	_cleanup_free_ struct file_handle ha = NULL, hb = NULL;	13,763✔
298	int mntida = -1, mntidb = -1;	13,763✔
299
300	r = name_to_handle_at_try_fid(	13,763✔
301	fda,
302	filea,
303	&ha,
304	&mntida,
305	ntha_flags);
306	if (r < 0) {	13,763✔
UNCOV 307	if (is_name_to_handle_at_fatal_error(r))	×
308	return r;
309
UNCOV 310	goto fallback;	×
311	}
312
313	r = name_to_handle_at_try_fid(	13,763✔
314	fdb,
315	fileb,
316	&hb,
317	&mntidb,
318	ntha_flags);
319	if (r < 0) {	13,763✔
UNCOV 320	if (is_name_to_handle_at_fatal_error(r))	×
321	return r;
322
UNCOV 323	goto fallback;	×
324	}
325
326	/* Now compare the two file handles */
327	if (!file_handle_equal(ha, hb))	13,763✔
328	return false;
329
330	/* If the file handles are the same and they come from the same mount ID? Great, then we are
331	* good, they are definitely the same */
332	if (mntida == mntidb)	13,475✔
333	return true;
334
335	/* File handles are the same, they are not on the same mount id. This might either be because
336	* they are on two entirely different file systems, that just happen to have the same FIDs
337	* (because they originally where created off the same disk images), or it could be because
338	* they are located on two distinct bind mounts of the same fs. To check that, let's look at
339	* .st_rdev of the inode. We simply reuse the fallback codepath for that, since it checks
340	* exactly that (it checks slightly more, but we don't care.) */
341	}
342
UNCOV 343	fallback:	×
344	if (fstatat(fda, strempty(filea), &sta, flags) < 0)	208✔
UNCOV 345	return log_debug_errno(errno, "Cannot stat %s: %m", strna(filea));	×
346
347	if (fstatat(fdb, strempty(fileb), &stb, flags) < 0)	208✔
348	return log_debug_errno(errno, "Cannot stat %s: %m", strna(fileb));	×
349
350	return stat_inode_same(&sta, &stb);	104✔
351	}
352
353	bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {	8,504,770✔
354	assert(s);	8,504,770✔
355	assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));	8,504,770✔
356
357	return F_TYPE_EQUAL(s->f_type, magic_value);	8,504,770✔
358	}
359
360	int is_fs_type_at(int dir_fd, const char *path, statfs_f_type_t magic_value) {	8,227,310✔
361	struct statfs s;	8,227,310✔
362	int r;	8,227,310✔
363
364	r = xstatfsat(dir_fd, path, &s);	8,227,310✔
365	if (r < 0)	8,227,310✔
366	return r;	8,227,310✔
367
368	return is_fs_type(&s, magic_value);	8,227,309✔
369	}
370
371	bool is_temporary_fs(const struct statfs *s) {	8,312✔
372	return fs_in_group(s, FILESYSTEM_SET_TEMPORARY);	8,312✔
373	}
374
375	bool is_network_fs(const struct statfs *s) {	16,080✔
376	return fs_in_group(s, FILESYSTEM_SET_NETWORK);	16,080✔
377	}
378
379	int fd_is_temporary_fs(int fd) {	147✔
380	struct statfs s;	147✔
381
382	if (fstatfs(fd, &s) < 0)	147✔
UNCOV 383	return -errno;	×
384
385	return is_temporary_fs(&s);	147✔
386	}
387
388	int fd_is_network_fs(int fd) {	15,977✔
389	struct statfs s;	15,977✔
390
391	if (fstatfs(fd, &s) < 0)	15,977✔
UNCOV 392	return -errno;	×
393
394	return is_network_fs(&s);	15,977✔
395	}
396
397	int path_is_temporary_fs(const char *path) {	11✔
398	struct statfs s;	11✔
399
400	if (statfs(path, &s) < 0)	11✔
401	return -errno;	2✔
402
403	return is_temporary_fs(&s);	9✔
404	}
405
UNCOV 406	int path_is_network_fs(const char *path) {	×
UNCOV 407	struct statfs s;	×
408
UNCOV 409	if (statfs(path, &s) < 0)	×
UNCOV 410	return -errno;	×
411
412	return is_network_fs(&s);	×
413	}
414
415	int proc_mounted(void) {	28,365✔
416	int r;	28,365✔
417
418	/* A quick check of procfs is properly mounted */
419
420	r = path_is_fs_type("/proc/", PROC_SUPER_MAGIC);	28,365✔
421	if (r == -ENOENT) /* not mounted at all */	28,365✔
UNCOV 422	return false;	×
423
424	return r;
425	}
426
427	bool stat_inode_same(const struct stat a, const struct stat b) {	1,341,559✔
428
429	/* Returns if the specified stat structure references the same (though possibly modified) inode. Does
430	* a thorough check, comparing inode nr, backing device and if the inode is still of the same type. */
431
432	return stat_is_set(a) && stat_is_set(b) &&	2,681,327✔
433	((a->st_mode ^ b->st_mode) & S_IFMT) == 0 && /* same inode type */	1,302,397✔
434	a->st_dev == b->st_dev &&	2,591,160✔
435	a->st_ino == b->st_ino;	1,249,601✔
436	}
437
438	bool stat_inode_unmodified(const struct stat a, const struct stat b) {	114,898✔
439
440	/* Returns if the specified stat structures reference the same, unmodified inode. This check tries to
441	* be reasonably careful when detecting changes: we check both inode and mtime, to cater for file
442	* systems where mtimes are fixed to 0 (think: ostree/nixos type installations). We also check file
443	* size, backing device, inode type and if this refers to a device not the major/minor.
444	*
445	* Note that we don't care if file attributes such as ownership or access mode change, this here is
446	* about contents of the file. The purpose here is to detect file contents changes, and nothing
447	* else. */
448
449	return stat_inode_same(a, b) &&	114,898✔
450	a->st_mtim.tv_sec == b->st_mtim.tv_sec &&	69,094✔
451	a->st_mtim.tv_nsec == b->st_mtim.tv_nsec &&	68,959✔
452	(!S_ISREG(a->st_mode) \|\| a->st_size == b->st_size) && /* if regular file, compare file size */	183,836✔
453	(!(S_ISCHR(a->st_mode) \|\| S_ISBLK(a->st_mode)) \|\| a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */	68,938✔
454	}
455
456	bool statx_inode_same(const struct statx a, const struct statx b) {	3,301,385✔
457
458	/* Same as stat_inode_same() but for struct statx */
459
460	return statx_is_set(a) && statx_is_set(b) &&	6,602,770✔
461	FLAGS_SET(a->stx_mask, STATX_TYPE\|STATX_INO) && FLAGS_SET(b->stx_mask, STATX_TYPE\|STATX_INO) &&	3,301,385✔
462	((a->stx_mode ^ b->stx_mode) & S_IFMT) == 0 &&	3,301,385✔
463	a->stx_dev_major == b->stx_dev_major &&	3,301,385✔
464	a->stx_dev_minor == b->stx_dev_minor &&	3,092,052✔
465	a->stx_ino == b->stx_ino;	3,076,234✔
466	}
467
468	bool statx_mount_same(const struct statx a, const struct statx b) {	3,047,683✔
469	if (!statx_is_set(a) \|\| !statx_is_set(b))	6,095,366✔
470	return false;
471
472	/* if we have the mount ID, that's all we need */
473	if (FLAGS_SET(a->stx_mask, STATX_MNT_ID) && FLAGS_SET(b->stx_mask, STATX_MNT_ID))	3,047,683✔
474	return a->stx_mnt_id == b->stx_mnt_id;	3,047,683✔
475
476	/* Otherwise, major/minor of backing device must match */
UNCOV 477	return a->stx_dev_major == b->stx_dev_major &&	×
UNCOV 478	a->stx_dev_minor == b->stx_dev_minor;	×
479	}
480
481	int xstatfsat(int dir_fd, const char path, struct statfs ret) {	8,227,690✔
482	_cleanup_close_ int fd = -EBADF;	8,227,690✔
483
484	assert(dir_fd >= 0 \|\| dir_fd == AT_FDCWD);	8,227,690✔
485	assert(ret);	8,227,690✔
486
487	if (!isempty(path)) {	8,227,690✔
488	fd = xopenat(dir_fd, path, O_PATH\|O_CLOEXEC\|O_NOCTTY);	28,859✔
489	if (fd < 0)	28,859✔
490	return fd;
491	dir_fd = fd;
492	}
493
494	return RET_NERRNO(fstatfs(dir_fd, ret));	8,227,690✔
495	}
496
497	usec_t statx_timestamp_load(const struct statx_timestamp *ts) {	4,983✔
498	return timespec_load(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });	4,983✔
499	}
500	nsec_t statx_timestamp_load_nsec(const struct statx_timestamp *ts) {	860✔
501	return timespec_load_nsec(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });	860✔
502	}
503
504	void inode_hash_func(const struct stat q, struct siphash state) {	37,141✔
505	siphash24_compress_typesafe(q->st_dev, state);	37,141✔
506	siphash24_compress_typesafe(q->st_ino, state);	37,141✔
507	}	37,141✔
508
509	int inode_compare_func(const struct stat a, const struct stat b) {	30,977✔
510	int r;	30,977✔
511
512	r = CMP(a->st_dev, b->st_dev);	30,977✔
513	if (r != 0)	26,197✔
514	return r;	4,851✔
515
516	return CMP(a->st_ino, b->st_ino);	26,126✔
517	}
518
519	DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(inode_hash_ops, struct stat, inode_hash_func, inode_compare_func, free);	787✔
520
521	const char* inode_type_to_string(mode_t m) {	7,478✔
522
523	/* Returns a short string for the inode type. We use the same name as the underlying macros for each
524	* inode type. */
525
526	switch (m & S_IFMT) {	7,478✔
527	case S_IFREG:
528	return "reg";
529	case S_IFDIR:	2,936✔
530	return "dir";	2,936✔
531	case S_IFLNK:	1✔
532	return "lnk";	1✔
533	case S_IFCHR:	862✔
534	return "chr";	862✔
535	case S_IFBLK:	416✔
536	return "blk";	416✔
537	case S_IFIFO:	416✔
538	return "fifo";	416✔
539	case S_IFSOCK:	568✔
540	return "sock";	568✔
541	}
542
543	/* Note anonymous inodes in the kernel will have a zero type. Hence fstat() of an eventfd() will
544	* return an .st_mode where we'll return NULL here! */
545	return NULL;	3✔
546	}
547
548	mode_t inode_type_from_string(const char *s) {	13✔
549	if (!s)	13✔
550	return MODE_INVALID;
551
552	if (streq(s, "reg"))	13✔
553	return S_IFREG;
554	if (streq(s, "dir"))	10✔
555	return S_IFDIR;
556	if (streq(s, "lnk"))	7✔
557	return S_IFLNK;
558	if (streq(s, "chr"))	6✔
559	return S_IFCHR;
560	if (streq(s, "blk"))	5✔
561	return S_IFBLK;
562	if (streq(s, "fifo"))	4✔
563	return S_IFIFO;
564	if (streq(s, "sock"))	2✔
565	return S_IFSOCK;	2✔
566
567	return MODE_INVALID;
568	}

systemd / systemd / 15263807472

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