#include <sys/xattr.h>
#include <libgen.h>
#include <sys/statvfs.h>
+#include <sys/file.h>
#include <linux/fs.h>
#undef basename
memcpy(r, prefix, pl);
for (f = s, t = r + pl; f < s + length; f++) {
+ size_t remaining = s + length - f;
+ assert(remaining > 0);
- if (*f != '\\') {
+ if (*f != '\\') { /* a literal literal */
*(t++) = *f;
continue;
}
+ if (--remaining == 0) { /* copy trailing backslash verbatim */
+ *(t++) = *f;
+ break;
+ }
+
f++;
switch (*f) {
case 'x': {
/* hexadecimal encoding */
- int a, b;
+ int a = -1, b = -1;
- a = unhexchar(f[1]);
- b = unhexchar(f[2]);
+ if (remaining >= 2) {
+ a = unhexchar(f[1]);
+ b = unhexchar(f[2]);
+ }
if (a < 0 || b < 0 || (a == 0 && b == 0)) {
/* Invalid escape code, let's take it literal then */
case '6':
case '7': {
/* octal encoding */
- int a, b, c;
+ int a = -1, b = -1, c = -1;
- a = unoctchar(f[0]);
- b = unoctchar(f[1]);
- c = unoctchar(f[2]);
+ if (remaining >= 3) {
+ a = unoctchar(f[0]);
+ b = unoctchar(f[1]);
+ c = unoctchar(f[2]);
+ }
if (a < 0 || b < 0 || c < 0 || (a == 0 && b == 0 && c == 0)) {
/* Invalid escape code, let's take it literal then */
break;
}
- case 0:
- /* premature end of string. */
- *(t++) = '\\';
- goto finish;
-
default:
/* Invalid escape code, let's take it literal then */
*(t++) = '\\';
}
}
-finish:
*t = 0;
return r;
}
return true;
}
-bool image_name_is_valid(const char *s) {
- if (!filename_is_valid(s))
- return false;
-
- if (string_has_cc(s, NULL))
- return false;
-
- if (!utf8_is_valid(s))
- return false;
-
- /* Temporary files for atomically creating new files */
- if (startswith(s, ".#"))
- return false;
-
- return true;
-}
-
int pipe_eof(int fd) {
struct pollfd pollfd = {
.fd = fd,
return fa == fb;
}
-int chattr_fd(int fd, bool b, int mask) {
- int old_attr, new_attr;
+int chattr_fd(int fd, bool b, unsigned mask) {
+ unsigned old_attr, new_attr;
assert(fd >= 0);
+ if (mask == 0)
+ return 0;
+
if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)
return -errno;
return 0;
}
-int chattr_path(const char *p, bool b, int mask) {
+int chattr_path(const char *p, bool b, unsigned mask) {
_cleanup_close_ int fd = -1;
- fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+ assert(p);
+
+ if (mask == 0)
+ return 0;
+
+ fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fd < 0)
return -errno;
return chattr_fd(fd, b, mask);
}
+
+int read_attr_fd(int fd, unsigned *ret) {
+ assert(fd >= 0);
+
+ if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int read_attr_path(const char *p, unsigned *ret) {
+ _cleanup_close_ int fd = -1;
+
+ assert(p);
+ assert(ret);
+
+ fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+ if (fd < 0)
+ return -errno;
+
+ return read_attr_fd(fd, ret);
+}
+
+int make_lock_file(const char *p, int operation, LockFile *ret) {
+ _cleanup_close_ int fd = -1;
+ _cleanup_free_ char *t = NULL;
+ int r;
+
+ /*
+ * We use UNPOSIX locks if they are available. They have nice
+ * semantics, and are mostly compatible with NFS. However,
+ * they are only available on new kernels. When we detect we
+ * are running on an older kernel, then we fall back to good
+ * old BSD locks. They also have nice semantics, but are
+ * slightly problematic on NFS, where they are upgraded to
+ * POSIX locks, even though locally they are orthogonal to
+ * POSIX locks.
+ */
+
+ t = strdup(p);
+ if (!t)
+ return -ENOMEM;
+
+ for (;;) {
+ struct flock fl = {
+ .l_type = (operation & ~LOCK_NB) == LOCK_EX ? F_WRLCK : F_RDLCK,
+ .l_whence = SEEK_SET,
+ };
+ struct stat st;
+
+ fd = open(p, O_CREAT|O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NOCTTY, 0600);
+ if (fd < 0)
+ return -errno;
+
+ r = fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl);
+ if (r < 0) {
+
+ /* If the kernel is too old, use good old BSD locks */
+ if (errno == EINVAL)
+ r = flock(fd, operation);
+
+ if (r < 0)
+ return errno == EAGAIN ? -EBUSY : -errno;
+ }
+
+ /* If we acquired the lock, let's check if the file
+ * still exists in the file system. If not, then the
+ * previous exclusive owner removed it and then closed
+ * it. In such a case our acquired lock is worthless,
+ * hence try again. */
+
+ r = fstat(fd, &st);
+ if (r < 0)
+ return -errno;
+ if (st.st_nlink > 0)
+ break;
+
+ fd = safe_close(fd);
+ }
+
+ ret->path = t;
+ ret->fd = fd;
+ ret->operation = operation;
+
+ fd = -1;
+ t = NULL;
+
+ return r;
+}
+
+int make_lock_file_for(const char *p, int operation, LockFile *ret) {
+ const char *fn;
+ char *t;
+
+ assert(p);
+ assert(ret);
+
+ fn = basename(p);
+ if (!filename_is_valid(fn))
+ return -EINVAL;
+
+ t = newa(char, strlen(p) + 2 + 4 + 1);
+ stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), ".lck");
+
+ return make_lock_file(t, operation, ret);
+}
+
+void release_lock_file(LockFile *f) {
+ int r;
+
+ if (!f)
+ return;
+
+ if (f->path) {
+
+ /* If we are the exclusive owner we can safely delete
+ * the lock file itself. If we are not the exclusive
+ * owner, we can try becoming it. */
+
+ if (f->fd >= 0 &&
+ (f->operation & ~LOCK_NB) == LOCK_SH) {
+ static const struct flock fl = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ };
+
+ r = fcntl(f->fd, F_OFD_SETLK, &fl);
+ if (r < 0 && errno == EINVAL)
+ r = flock(f->fd, LOCK_EX|LOCK_NB);
+
+ if (r >= 0)
+ f->operation = LOCK_EX|LOCK_NB;
+ }
+
+ if ((f->operation & ~LOCK_NB) == LOCK_EX)
+ unlink_noerrno(f->path);
+
+ free(f->path);
+ f->path = NULL;
+ }
+
+ f->fd = safe_close(f->fd);
+ f->operation = 0;
+}