qemu-e2k/hw/9pfs/9p-util-darwin.c

148 lines
4.0 KiB
C

/*
* 9p utilities (Darwin Implementation)
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/xattr.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "9p-util.h"
ssize_t fgetxattrat_nofollow(int dirfd, const char *filename, const char *name,
void *value, size_t size)
{
int ret;
int fd = openat_file(dirfd, filename,
O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0);
if (fd == -1) {
return -1;
}
ret = fgetxattr(fd, name, value, size, 0, 0);
close_preserve_errno(fd);
return ret;
}
ssize_t flistxattrat_nofollow(int dirfd, const char *filename,
char *list, size_t size)
{
int ret;
int fd = openat_file(dirfd, filename,
O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0);
if (fd == -1) {
return -1;
}
ret = flistxattr(fd, list, size, 0);
close_preserve_errno(fd);
return ret;
}
ssize_t fremovexattrat_nofollow(int dirfd, const char *filename,
const char *name)
{
int ret;
int fd = openat_file(dirfd, filename, O_PATH_9P_UTIL | O_NOFOLLOW, 0);
if (fd == -1) {
return -1;
}
ret = fremovexattr(fd, name, 0);
close_preserve_errno(fd);
return ret;
}
int fsetxattrat_nofollow(int dirfd, const char *filename, const char *name,
void *value, size_t size, int flags)
{
int ret;
int fd = openat_file(dirfd, filename, O_PATH_9P_UTIL | O_NOFOLLOW, 0);
if (fd == -1) {
return -1;
}
ret = fsetxattr(fd, name, value, size, 0, flags);
close_preserve_errno(fd);
return ret;
}
/*
* As long as mknodat is not available on macOS, this workaround
* using pthread_fchdir_np is needed.
*
* Radar filed with Apple for implementing mknodat:
* rdar://FB9862426 (https://openradar.appspot.com/FB9862426)
*/
#if defined CONFIG_PTHREAD_FCHDIR_NP
static int create_socket_file_at_cwd(const char *filename, mode_t mode) {
int fd, err;
struct sockaddr_un addr = {
.sun_family = AF_UNIX
};
err = snprintf(addr.sun_path, sizeof(addr.sun_path), "./%s", filename);
if (err < 0 || err >= sizeof(addr.sun_path)) {
errno = ENAMETOOLONG;
return -1;
}
fd = socket(PF_UNIX, SOCK_DGRAM, 0);
if (fd == -1) {
return fd;
}
err = bind(fd, (struct sockaddr *) &addr, sizeof(addr));
if (err == -1) {
goto out;
}
/*
* FIXME: Should rather be using descriptor-based fchmod() on the
* socket file descriptor above (preferably before bind() call),
* instead of path-based fchmodat(), to prevent concurrent transient
* state issues between creating the named FIFO file at bind() and
* delayed adjustment of permissions at fchmodat(). However currently
* macOS (12.x) does not support such operations on socket file
* descriptors yet.
*
* Filed report with Apple: FB9997731
*/
err = fchmodat(AT_FDCWD, filename, mode, AT_SYMLINK_NOFOLLOW);
out:
close_preserve_errno(fd);
return err;
}
int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev)
{
int preserved_errno, err;
if (S_ISREG(mode) || !(mode & S_IFMT)) {
int fd = openat_file(dirfd, filename, O_CREAT, mode);
if (fd == -1) {
return fd;
}
close(fd);
return 0;
}
if (!pthread_fchdir_np) {
error_report_once("pthread_fchdir_np() not available on this version of macOS");
errno = ENOTSUP;
return -1;
}
if (pthread_fchdir_np(dirfd) < 0) {
return -1;
}
if (S_ISSOCK(mode)) {
err = create_socket_file_at_cwd(filename, mode);
} else {
err = mknod(filename, mode, dev);
}
preserved_errno = errno;
/* Stop using the thread-local cwd */
pthread_fchdir_np(-1);
if (err < 0) {
errno = preserved_errno;
}
return err;
}
#endif