#include "qemu/osdep.h"
#include "9p.h"
+ #include "9p-local.h"
#include "9p-xattr.h"
+ #include "9p-util.h"
#include "fsdev/qemu-fsdev.h" /* local_ops */
#include <arpa/inet.h>
#include <pwd.h>
#define BTRFS_SUPER_MAGIC 0x9123683E
#endif
- #define VIRTFS_META_DIR ".virtfs_metadata"
+ typedef struct {
+ int mountfd;
+ } LocalData;
- static char *local_mapped_attr_path(FsContext *ctx, const char *path)
+ int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags,
+ mode_t mode)
{
- int dirlen;
- const char *name = strrchr(path, '/');
- if (name) {
- dirlen = name - path;
- ++name;
- } else {
- name = path;
- dirlen = 0;
+ LocalData *data = fs_ctx->private;
+
+ /* All paths are relative to the path data->mountfd points to */
+ while (*path == '/') {
+ path++;
}
- return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root,
- dirlen, path, VIRTFS_META_DIR, name);
+
+ return relative_openat_nofollow(data->mountfd, path, flags, mode);
+ }
+
+ int local_opendir_nofollow(FsContext *fs_ctx, const char *path)
+ {
+ return local_open_nofollow(fs_ctx, path, O_DIRECTORY | O_RDONLY, 0);
+ }
+
+ static void renameat_preserve_errno(int odirfd, const char *opath, int ndirfd,
+ const char *npath)
+ {
+ int serrno = errno;
+ renameat(odirfd, opath, ndirfd, npath);
+ errno = serrno;
}
- static FILE *local_fopen(const char *path, const char *mode)
+ static void unlinkat_preserve_errno(int dirfd, const char *path, int flags)
+ {
+ int serrno = errno;
+ unlinkat(dirfd, path, flags);
+ errno = serrno;
+ }
+
+ #define VIRTFS_META_DIR ".virtfs_metadata"
+
+ static FILE *local_fopenat(int dirfd, const char *name, const char *mode)
{
int fd, o_mode = 0;
FILE *fp;
- int flags = O_NOFOLLOW;
+ int flags;
/*
* only supports two modes
*/
if (mode[0] == 'r') {
- flags |= O_RDONLY;
+ flags = O_RDONLY;
} else if (mode[0] == 'w') {
- flags |= O_WRONLY | O_TRUNC | O_CREAT;
+ flags = O_WRONLY | O_TRUNC | O_CREAT;
o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
} else {
return NULL;
}
- fd = open(path, flags, o_mode);
+ fd = openat_file(dirfd, name, flags, o_mode);
if (fd == -1) {
return NULL;
}
}
#define ATTR_MAX 100
- static void local_mapped_file_attr(FsContext *ctx, const char *path,
+ static void local_mapped_file_attr(int dirfd, const char *name,
struct stat *stbuf)
{
FILE *fp;
char buf[ATTR_MAX];
- char *attr_path;
+ int map_dirfd;
- attr_path = local_mapped_attr_path(ctx, path);
- fp = local_fopen(attr_path, "r");
- g_free(attr_path);
+ map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+ if (map_dirfd == -1) {
+ return;
+ }
+
+ fp = local_fopenat(map_dirfd, name, "r");
+ close_preserve_errno(map_dirfd);
if (!fp) {
return;
}
static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
{
- int err;
- char *buffer;
- char *path = fs_path->data;
+ int err = -1;
+ char *dirpath = g_path_get_dirname(fs_path->data);
+ char *name = g_path_get_basename(fs_path->data);
+ int dirfd;
+
+ dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+ if (dirfd == -1) {
+ goto out;
+ }
- buffer = rpath(fs_ctx, path);
- err = lstat(buffer, stbuf);
+ err = fstatat(dirfd, name, stbuf, AT_SYMLINK_NOFOLLOW);
if (err) {
goto err_out;
}
gid_t tmp_gid;
mode_t tmp_mode;
dev_t tmp_dev;
- if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
+
+ if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.uid", &tmp_uid,
+ sizeof(uid_t)) > 0) {
stbuf->st_uid = le32_to_cpu(tmp_uid);
}
- if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
+ if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.gid", &tmp_gid,
+ sizeof(gid_t)) > 0) {
stbuf->st_gid = le32_to_cpu(tmp_gid);
}
- if (getxattr(buffer, "user.virtfs.mode",
- &tmp_mode, sizeof(mode_t)) > 0) {
+ if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.mode", &tmp_mode,
+ sizeof(mode_t)) > 0) {
stbuf->st_mode = le32_to_cpu(tmp_mode);
}
- if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
+ if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.rdev", &tmp_dev,
+ sizeof(dev_t)) > 0) {
stbuf->st_rdev = le64_to_cpu(tmp_dev);
}
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- local_mapped_file_attr(fs_ctx, path, stbuf);
+ local_mapped_file_attr(dirfd, name, stbuf);
}
err_out:
- g_free(buffer);
- return err;
- }
-
- static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
- {
- int err;
- char *attr_dir;
- char *tmp_path = g_strdup(path);
-
- attr_dir = g_strdup_printf("%s/%s/%s",
- ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
-
- err = mkdir(attr_dir, 0700);
- if (err < 0 && errno == EEXIST) {
- err = 0;
- }
- g_free(attr_dir);
- g_free(tmp_path);
+ close_preserve_errno(dirfd);
+ out:
+ g_free(name);
+ g_free(dirpath);
return err;
}
- static int local_set_mapped_file_attr(FsContext *ctx,
- const char *path, FsCred *credp)
+ static int local_set_mapped_file_attrat(int dirfd, const char *name,
+ FsCred *credp)
{
FILE *fp;
- int ret = 0;
+ int ret;
char buf[ATTR_MAX];
- char *attr_path;
int uid = -1, gid = -1, mode = -1, rdev = -1;
+ int map_dirfd;
+
+ ret = mkdirat(dirfd, VIRTFS_META_DIR, 0700);
+ if (ret < 0 && errno != EEXIST) {
+ return -1;
+ }
- attr_path = local_mapped_attr_path(ctx, path);
- fp = local_fopen(attr_path, "r");
+ map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+ if (map_dirfd == -1) {
+ return -1;
+ }
+
+ fp = local_fopenat(map_dirfd, name, "r");
if (!fp) {
- goto create_map_file;
+ if (errno == ENOENT) {
+ goto update_map_file;
+ } else {
+ close_preserve_errno(map_dirfd);
+ return -1;
+ }
}
memset(buf, 0, ATTR_MAX);
while (fgets(buf, ATTR_MAX, fp)) {
if (!strncmp(buf, "virtfs.uid", 10)) {
- uid = atoi(buf+11);
+ uid = atoi(buf + 11);
} else if (!strncmp(buf, "virtfs.gid", 10)) {
- gid = atoi(buf+11);
+ gid = atoi(buf + 11);
} else if (!strncmp(buf, "virtfs.mode", 11)) {
- mode = atoi(buf+12);
+ mode = atoi(buf + 12);
} else if (!strncmp(buf, "virtfs.rdev", 11)) {
- rdev = atoi(buf+12);
+ rdev = atoi(buf + 12);
}
memset(buf, 0, ATTR_MAX);
}
fclose(fp);
- goto update_map_file;
-
- create_map_file:
- ret = local_create_mapped_attr_dir(ctx, path);
- if (ret < 0) {
- goto err_out;
- }
update_map_file:
- fp = local_fopen(attr_path, "w");
+ fp = local_fopenat(map_dirfd, name, "w");
+ close_preserve_errno(map_dirfd);
if (!fp) {
- ret = -1;
- goto err_out;
+ return -1;
}
if (credp->fc_uid != -1) {
rdev = credp->fc_rdev;
}
-
if (uid != -1) {
fprintf(fp, "virtfs.uid=%d\n", uid);
}
}
fclose(fp);
- err_out:
- g_free(attr_path);
+ return 0;
+ }
+
+ static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode)
+ {
+ int fd, ret;
+
+ /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW).
+ * Unfortunately, the linux kernel doesn't implement it yet. As an
+ * alternative, let's open the file and use fchmod() instead. This
+ * may fail depending on the permissions of the file, but it is the
+ * best we can do to avoid TOCTTOU. We first try to open read-only
+ * in case name points to a directory. If that fails, we try write-only
+ * in case name doesn't point to a directory.
+ */
+ fd = openat_file(dirfd, name, O_RDONLY, 0);
+ if (fd == -1) {
+ /* In case the file is writable-only and isn't a directory. */
+ if (errno == EACCES) {
+ fd = openat_file(dirfd, name, O_WRONLY, 0);
+ }
+ if (fd == -1 && errno == EISDIR) {
+ errno = EACCES;
+ }
+ }
+ if (fd == -1) {
+ return -1;
+ }
+ ret = fchmod(fd, mode);
+ close_preserve_errno(fd);
return ret;
}
- static int local_set_xattr(const char *path, FsCred *credp)
+ static int local_set_xattrat(int dirfd, const char *path, FsCred *credp)
{
int err;
if (credp->fc_uid != -1) {
uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
- err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0);
+ err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.uid", &tmp_uid,
+ sizeof(uid_t), 0);
if (err) {
return err;
}
}
if (credp->fc_gid != -1) {
uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
- err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0);
+ err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.gid", &tmp_gid,
+ sizeof(gid_t), 0);
if (err) {
return err;
}
}
if (credp->fc_mode != -1) {
uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
- err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0);
+ err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.mode", &tmp_mode,
+ sizeof(mode_t), 0);
if (err) {
return err;
}
}
if (credp->fc_rdev != -1) {
uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
- err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0);
+ err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.rdev", &tmp_rdev,
+ sizeof(dev_t), 0);
if (err) {
return err;
}
return 0;
}
- static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
- FsCred *credp)
+ static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd,
+ const char *name, FsCred *credp)
{
- char *buffer;
-
- buffer = rpath(fs_ctx, path);
- if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) {
+ if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+ AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) < 0) {
/*
* If we fail to change ownership and if we are
* using security model none. Ignore the error
*/
if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
- goto err;
+ return -1;
}
}
- if (chmod(buffer, credp->fc_mode & 07777) < 0) {
- goto err;
- }
-
- g_free(buffer);
- return 0;
- err:
- g_free(buffer);
- return -1;
+ return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777);
}
static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
char *buf, size_t bufsz)
{
ssize_t tsize = -1;
- char *buffer;
- char *path = fs_path->data;
if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
(fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
int fd;
- buffer = rpath(fs_ctx, path);
- fd = open(buffer, O_RDONLY | O_NOFOLLOW);
- g_free(buffer);
+
+ fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0);
if (fd == -1) {
return -1;
}
do {
tsize = read(fd, (void *)buf, bufsz);
} while (tsize == -1 && errno == EINTR);
- close(fd);
+ close_preserve_errno(fd);
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- tsize = readlink(buffer, buf, bufsz);
- g_free(buffer);
+ char *dirpath = g_path_get_dirname(fs_path->data);
+ char *name = g_path_get_basename(fs_path->data);
+ int dirfd;
+
+ dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+ if (dirfd == -1) {
+ goto out;
+ }
+
+ tsize = readlinkat(dirfd, name, buf, bufsz);
+ close_preserve_errno(dirfd);
+ out:
+ g_free(name);
+ g_free(dirpath);
}
return tsize;
}
static int local_open(FsContext *ctx, V9fsPath *fs_path,
int flags, V9fsFidOpenState *fs)
{
- char *buffer;
- char *path = fs_path->data;
+ int fd;
- buffer = rpath(ctx, path);
- fs->fd = open(buffer, flags | O_NOFOLLOW);
- g_free(buffer);
+ fd = local_open_nofollow(ctx, fs_path->data, flags, 0);
+ if (fd == -1) {
+ return -1;
+ }
+ fs->fd = fd;
return fs->fd;
}
static int local_opendir(FsContext *ctx,
V9fsPath *fs_path, V9fsFidOpenState *fs)
{
- char *buffer;
- char *path = fs_path->data;
+ int dirfd;
+ DIR *stream;
+
+ dirfd = local_opendir_nofollow(ctx, fs_path->data);
+ if (dirfd == -1) {
+ return -1;
+ }
- buffer = rpath(ctx, path);
- fs->dir.stream = opendir(buffer);
- g_free(buffer);
- if (!fs->dir.stream) {
+ stream = fdopendir(dirfd);
+ if (!stream) {
return -1;
}
+ fs->dir.stream = stream;
return 0;
}
static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
- char *buffer;
+ char *dirpath = g_path_get_dirname(fs_path->data);
+ char *name = g_path_get_basename(fs_path->data);
int ret = -1;
- char *path = fs_path->data;
+ int dirfd;
+
+ dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+ if (dirfd == -1) {
+ goto out;
+ }
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
- buffer = rpath(fs_ctx, path);
- ret = local_set_xattr(buffer, credp);
- g_free(buffer);
+ ret = local_set_xattrat(dirfd, name, credp);
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- return local_set_mapped_file_attr(fs_ctx, path, credp);
- } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
- (fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- ret = chmod(buffer, credp->fc_mode);
- g_free(buffer);
+ ret = local_set_mapped_file_attrat(dirfd, name, credp);
+ } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+ fs_ctx->export_flags & V9FS_SM_NONE) {
+ ret = fchmodat_nofollow(dirfd, name, credp->fc_mode);
}
+ close_preserve_errno(dirfd);
+
+ out:
+ g_free(dirpath);
+ g_free(name);
return ret;
}
static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
const char *name, FsCred *credp)
{
- char *path;
int err = -1;
- int serrno = 0;
- V9fsString fullname;
- char *buffer = NULL;
+ int dirfd;
- v9fs_string_init(&fullname);
- v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
- path = fullname.data;
+ dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+ if (dirfd == -1) {
+ return -1;
+ }
- /* Determine the security model */
- if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
- buffer = rpath(fs_ctx, path);
- err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+ fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+ err = mknodat(dirfd, name, SM_LOCAL_MODE_BITS | S_IFREG, 0);
if (err == -1) {
goto out;
}
- err = local_set_xattr(buffer, credp);
- if (err == -1) {
- serrno = errno;
- goto err_end;
- }
- } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- buffer = rpath(fs_ctx, path);
- err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
- if (err == -1) {
- goto out;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+ err = local_set_xattrat(dirfd, name, credp);
+ } else {
+ err = local_set_mapped_file_attrat(dirfd, name, credp);
}
- err = local_set_mapped_file_attr(fs_ctx, path, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
- } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
- (fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
+ } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+ fs_ctx->export_flags & V9FS_SM_NONE) {
+ err = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
if (err == -1) {
goto out;
}
- err = local_post_create_passthrough(fs_ctx, path, credp);
+ err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
}
goto out;
err_end:
- remove(buffer);
- errno = serrno;
+ unlinkat_preserve_errno(dirfd, name, 0);
out:
- g_free(buffer);
- v9fs_string_free(&fullname);
+ close_preserve_errno(dirfd);
return err;
}
static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
const char *name, FsCred *credp)
{
- char *path;
int err = -1;
- int serrno = 0;
- V9fsString fullname;
- char *buffer = NULL;
+ int dirfd;
- v9fs_string_init(&fullname);
- v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
- path = fullname.data;
+ dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+ if (dirfd == -1) {
+ return -1;
+ }
- /* Determine the security model */
- if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
- buffer = rpath(fs_ctx, path);
- err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+ fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+ err = mkdirat(dirfd, name, SM_LOCAL_DIR_MODE_BITS);
if (err == -1) {
goto out;
}
- credp->fc_mode = credp->fc_mode|S_IFDIR;
- err = local_set_xattr(buffer, credp);
- if (err == -1) {
- serrno = errno;
- goto err_end;
- }
- } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- buffer = rpath(fs_ctx, path);
- err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
- if (err == -1) {
- goto out;
+ credp->fc_mode = credp->fc_mode | S_IFDIR;
+
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+ err = local_set_xattrat(dirfd, name, credp);
+ } else {
+ err = local_set_mapped_file_attrat(dirfd, name, credp);
}
- credp->fc_mode = credp->fc_mode|S_IFDIR;
- err = local_set_mapped_file_attr(fs_ctx, path, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
- } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
- (fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- err = mkdir(buffer, credp->fc_mode);
+ } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+ fs_ctx->export_flags & V9FS_SM_NONE) {
+ err = mkdirat(dirfd, name, credp->fc_mode);
if (err == -1) {
goto out;
}
- err = local_post_create_passthrough(fs_ctx, path, credp);
+ err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
}
goto out;
err_end:
- remove(buffer);
- errno = serrno;
+ unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR);
out:
- g_free(buffer);
- v9fs_string_free(&fullname);
+ close_preserve_errno(dirfd);
return err;
}
static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
int flags, FsCred *credp, V9fsFidOpenState *fs)
{
- char *path;
int fd = -1;
int err = -1;
- int serrno = 0;
- V9fsString fullname;
- char *buffer = NULL;
+ int dirfd;
/*
* Mark all the open to not follow symlinks
*/
flags |= O_NOFOLLOW;
- v9fs_string_init(&fullname);
- v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
- path = fullname.data;
+ dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+ if (dirfd == -1) {
+ return -1;
+ }
/* Determine the security model */
- if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
- buffer = rpath(fs_ctx, path);
- fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+ fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+ fd = openat_file(dirfd, name, flags, SM_LOCAL_MODE_BITS);
if (fd == -1) {
- err = fd;
goto out;
}
credp->fc_mode = credp->fc_mode|S_IFREG;
- /* Set cleint credentials in xattr */
- err = local_set_xattr(buffer, credp);
- if (err == -1) {
- serrno = errno;
- goto err_end;
- }
- } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- buffer = rpath(fs_ctx, path);
- fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
- if (fd == -1) {
- err = fd;
- goto out;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+ /* Set cleint credentials in xattr */
+ err = local_set_xattrat(dirfd, name, credp);
+ } else {
+ err = local_set_mapped_file_attrat(dirfd, name, credp);
}
- credp->fc_mode = credp->fc_mode|S_IFREG;
- /* Set client credentials in .virtfs_metadata directory files */
- err = local_set_mapped_file_attr(fs_ctx, path, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- fd = open(buffer, flags, credp->fc_mode);
+ fd = openat_file(dirfd, name, flags, credp->fc_mode);
if (fd == -1) {
- err = fd;
goto out;
}
- err = local_post_create_passthrough(fs_ctx, path, credp);
+ err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
}
goto out;
err_end:
- close(fd);
- remove(buffer);
- errno = serrno;
+ unlinkat_preserve_errno(dirfd, name,
+ flags & O_DIRECTORY ? AT_REMOVEDIR : 0);
+ close_preserve_errno(fd);
out:
- g_free(buffer);
- v9fs_string_free(&fullname);
+ close_preserve_errno(dirfd);
return err;
}
V9fsPath *dir_path, const char *name, FsCred *credp)
{
int err = -1;
- int serrno = 0;
- char *newpath;
- V9fsString fullname;
- char *buffer = NULL;
+ int dirfd;
- v9fs_string_init(&fullname);
- v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
- newpath = fullname.data;
+ dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
+ if (dirfd == -1) {
+ return -1;
+ }
/* Determine the security model */
- if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
+ fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
int fd;
ssize_t oldpath_size, write_size;
- buffer = rpath(fs_ctx, newpath);
- fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
+
+ fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR,
+ SM_LOCAL_MODE_BITS);
if (fd == -1) {
- err = fd;
goto out;
}
/* Write the oldpath (target) to the file. */
do {
write_size = write(fd, (void *)oldpath, oldpath_size);
} while (write_size == -1 && errno == EINTR);
+ close_preserve_errno(fd);
if (write_size != oldpath_size) {
- serrno = errno;
- close(fd);
- err = -1;
goto err_end;
}
- close(fd);
/* Set cleint credentials in symlink's xattr */
- credp->fc_mode = credp->fc_mode|S_IFLNK;
- err = local_set_xattr(buffer, credp);
- if (err == -1) {
- serrno = errno;
- goto err_end;
- }
- } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- int fd;
- ssize_t oldpath_size, write_size;
- buffer = rpath(fs_ctx, newpath);
- fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
- if (fd == -1) {
- err = fd;
- goto out;
- }
- /* Write the oldpath (target) to the file. */
- oldpath_size = strlen(oldpath);
- do {
- write_size = write(fd, (void *)oldpath, oldpath_size);
- } while (write_size == -1 && errno == EINTR);
+ credp->fc_mode = credp->fc_mode | S_IFLNK;
- if (write_size != oldpath_size) {
- serrno = errno;
- close(fd);
- err = -1;
- goto err_end;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
+ err = local_set_xattrat(dirfd, name, credp);
+ } else {
+ err = local_set_mapped_file_attrat(dirfd, name, credp);
}
- close(fd);
- /* Set cleint credentials in symlink's xattr */
- credp->fc_mode = credp->fc_mode|S_IFLNK;
- err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
if (err == -1) {
- serrno = errno;
goto err_end;
}
- } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
- (fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, newpath);
- err = symlink(oldpath, buffer);
+ } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
+ fs_ctx->export_flags & V9FS_SM_NONE) {
+ err = symlinkat(oldpath, dirfd, name);
if (err) {
goto out;
}
- err = lchown(buffer, credp->fc_uid, credp->fc_gid);
+ err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+ AT_SYMLINK_NOFOLLOW);
if (err == -1) {
/*
* If we fail to change ownership and if we are
* using security model none. Ignore the error
*/
if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
- serrno = errno;
goto err_end;
- } else
+ } else {
err = 0;
+ }
}
}
goto out;
err_end:
- remove(buffer);
- errno = serrno;
+ unlinkat_preserve_errno(dirfd, name, 0);
out:
- g_free(buffer);
- v9fs_string_free(&fullname);
+ close_preserve_errno(dirfd);
return err;
}
static int local_link(FsContext *ctx, V9fsPath *oldpath,
V9fsPath *dirpath, const char *name)
{
- int ret;
- V9fsString newpath;
- char *buffer, *buffer1;
+ char *odirpath = g_path_get_dirname(oldpath->data);
+ char *oname = g_path_get_basename(oldpath->data);
+ int ret = -1;
+ int odirfd, ndirfd;
+
+ odirfd = local_opendir_nofollow(ctx, odirpath);
+ if (odirfd == -1) {
+ goto out;
+ }
- v9fs_string_init(&newpath);
- v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
+ ndirfd = local_opendir_nofollow(ctx, dirpath->data);
+ if (ndirfd == -1) {
+ close_preserve_errno(odirfd);
+ goto out;
+ }
- buffer = rpath(ctx, oldpath->data);
- buffer1 = rpath(ctx, newpath.data);
- ret = link(buffer, buffer1);
- g_free(buffer);
- g_free(buffer1);
+ ret = linkat(odirfd, oname, ndirfd, name, 0);
+ if (ret < 0) {
+ goto out_close;
+ }
/* now link the virtfs_metadata files */
- if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
- /* Link the .virtfs_metadata files. Create the metada directory */
- ret = local_create_mapped_attr_dir(ctx, newpath.data);
- if (ret < 0) {
- goto err_out;
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+ int omap_dirfd, nmap_dirfd;
+
+ ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
+ if (ret < 0 && errno != EEXIST) {
+ goto err_undo_link;
}
- buffer = local_mapped_attr_path(ctx, oldpath->data);
- buffer1 = local_mapped_attr_path(ctx, newpath.data);
- ret = link(buffer, buffer1);
- g_free(buffer);
- g_free(buffer1);
+
+ omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
+ if (omap_dirfd == -1) {
+ goto err;
+ }
+
+ nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
+ if (nmap_dirfd == -1) {
+ close_preserve_errno(omap_dirfd);
+ goto err;
+ }
+
+ ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0);
+ close_preserve_errno(nmap_dirfd);
+ close_preserve_errno(omap_dirfd);
if (ret < 0 && errno != ENOENT) {
- goto err_out;
+ goto err_undo_link;
}
- }
- err_out:
- v9fs_string_free(&newpath);
- return ret;
- }
- static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
- {
- char *buffer;
- int ret;
- char *path = fs_path->data;
+ ret = 0;
+ }
+ goto out_close;
- buffer = rpath(ctx, path);
- ret = truncate(buffer, size);
- g_free(buffer);
+ err:
+ ret = -1;
+ err_undo_link:
+ unlinkat_preserve_errno(ndirfd, name, 0);
+ out_close:
+ close_preserve_errno(ndirfd);
+ close_preserve_errno(odirfd);
+ out:
+ g_free(oname);
+ g_free(odirpath);
return ret;
}
- static int local_rename(FsContext *ctx, const char *oldpath,
- const char *newpath)
+ static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
{
- int err;
- char *buffer, *buffer1;
+ int fd, ret;
- if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- err = local_create_mapped_attr_dir(ctx, newpath);
- if (err < 0) {
- return err;
- }
- /* rename the .virtfs_metadata files */
- buffer = local_mapped_attr_path(ctx, oldpath);
- buffer1 = local_mapped_attr_path(ctx, newpath);
- err = rename(buffer, buffer1);
- g_free(buffer);
- g_free(buffer1);
- if (err < 0 && errno != ENOENT) {
- return err;
- }
+ fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0);
+ if (fd == -1) {
+ return -1;
}
-
- buffer = rpath(ctx, oldpath);
- buffer1 = rpath(ctx, newpath);
- err = rename(buffer, buffer1);
- g_free(buffer);
- g_free(buffer1);
- return err;
+ ret = ftruncate(fd, size);
+ close_preserve_errno(fd);
+ return ret;
}
static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
- char *buffer;
+ char *dirpath = g_path_get_dirname(fs_path->data);
+ char *name = g_path_get_basename(fs_path->data);
int ret = -1;
- char *path = fs_path->data;
+ int dirfd;
+
+ dirfd = local_opendir_nofollow(fs_ctx, dirpath);
+ if (dirfd == -1) {
+ goto out;
+ }
if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
(fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
- buffer = rpath(fs_ctx, path);
- ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
- g_free(buffer);
+ ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
+ AT_SYMLINK_NOFOLLOW);
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
- buffer = rpath(fs_ctx, path);
- ret = local_set_xattr(buffer, credp);
- g_free(buffer);
+ ret = local_set_xattrat(dirfd, name, credp);
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- return local_set_mapped_file_attr(fs_ctx, path, credp);
+ ret = local_set_mapped_file_attrat(dirfd, name, credp);
}
+
+ close_preserve_errno(dirfd);
+ out:
+ g_free(name);
+ g_free(dirpath);
return ret;
}
static int local_utimensat(FsContext *s, V9fsPath *fs_path,
const struct timespec *buf)
{
- char *buffer;
- int ret;
- char *path = fs_path->data;
+ char *dirpath = g_path_get_dirname(fs_path->data);
+ char *name = g_path_get_basename(fs_path->data);
+ int dirfd, ret = -1;
+
+ dirfd = local_opendir_nofollow(s, dirpath);
+ if (dirfd == -1) {
+ goto out;
+ }
- buffer = rpath(s, path);
- ret = qemu_utimens(buffer, buf);
- g_free(buffer);
+ ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW);
+ close_preserve_errno(dirfd);
+ out:
+ g_free(dirpath);
+ g_free(name);
return ret;
}
- static int local_remove(FsContext *ctx, const char *path)
+ static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
+ int flags)
{
- int err;
- struct stat stbuf;
- char *buffer;
+ int ret = -1;
if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- buffer = rpath(ctx, path);
- err = lstat(buffer, &stbuf);
- g_free(buffer);
- if (err) {
- goto err_out;
- }
- /*
- * If directory remove .virtfs_metadata contained in the
- * directory
- */
- if (S_ISDIR(stbuf.st_mode)) {
- buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
- path, VIRTFS_META_DIR);
- err = remove(buffer);
- g_free(buffer);
- if (err < 0 && errno != ENOENT) {
+ int map_dirfd;
+
+ if (flags == AT_REMOVEDIR) {
+ int fd;
+
+ fd = openat(dirfd, name, O_RDONLY | O_DIRECTORY | O_PATH);
+ if (fd == -1) {
+ goto err_out;
+ }
+ /*
+ * If directory remove .virtfs_metadata contained in the
+ * directory
+ */
+ ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR);
+ close_preserve_errno(fd);
+ if (ret < 0 && errno != ENOENT) {
/*
* We didn't had the .virtfs_metadata file. May be file created
* in non-mapped mode ?. Ignore ENOENT.
}
/*
* Now remove the name from parent directory
- * .virtfs_metadata directory
+ * .virtfs_metadata directory.
*/
- buffer = local_mapped_attr_path(ctx, path);
- err = remove(buffer);
- g_free(buffer);
- if (err < 0 && errno != ENOENT) {
+ map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
+ ret = unlinkat(map_dirfd, name, 0);
+ close_preserve_errno(map_dirfd);
+ if (ret < 0 && errno != ENOENT) {
/*
* We didn't had the .virtfs_metadata file. May be file created
* in non-mapped mode ?. Ignore ENOENT.
}
}
- buffer = rpath(ctx, path);
- err = remove(buffer);
- g_free(buffer);
+ ret = unlinkat(dirfd, name, flags);
+ err_out:
+ return ret;
+ }
+
+ static int local_remove(FsContext *ctx, const char *path)
+ {
+ struct stat stbuf;
+ char *dirpath = g_path_get_dirname(path);
+ char *name = g_path_get_basename(path);
+ int flags = 0;
+ int dirfd;
+ int err = -1;
+
+ dirfd = local_opendir_nofollow(ctx, dirpath);
+ if (dirfd) {
+ goto out;
+ }
+
+ if (fstatat(dirfd, path, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) {
+ goto err_out;
+ }
+
+ if (S_ISDIR(stbuf.st_mode)) {
+ flags |= AT_REMOVEDIR;
+ }
+
+ err = local_unlinkat_common(ctx, dirfd, name, flags);
err_out:
+ close_preserve_errno(dirfd);
+ out:
+ g_free(name);
+ g_free(dirpath);
return err;
}
static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
{
- char *buffer;
- int ret;
- char *path = fs_path->data;
+ int fd, ret;
- buffer = rpath(s, path);
- ret = statfs(buffer, stbuf);
- g_free(buffer);
+ fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
+ ret = fstatfs(fd, stbuf);
+ close_preserve_errno(fd);
return ret;
}
const char *new_name)
{
int ret;
- V9fsString old_full_name, new_full_name;
+ int odirfd, ndirfd;
- v9fs_string_init(&old_full_name);
- v9fs_string_init(&new_full_name);
+ odirfd = local_opendir_nofollow(ctx, olddir->data);
+ if (odirfd == -1) {
+ return -1;
+ }
- v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
- v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
+ ndirfd = local_opendir_nofollow(ctx, newdir->data);
+ if (ndirfd == -1) {
+ close_preserve_errno(odirfd);
+ return -1;
+ }
- ret = local_rename(ctx, old_full_name.data, new_full_name.data);
- v9fs_string_free(&old_full_name);
- v9fs_string_free(&new_full_name);
+ ret = renameat(odirfd, old_name, ndirfd, new_name);
+ if (ret < 0) {
+ goto out;
+ }
+
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
+ int omap_dirfd, nmap_dirfd;
+
+ ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
+ if (ret < 0 && errno != EEXIST) {
+ goto err_undo_rename;
+ }
+
+ omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
+ if (omap_dirfd == -1) {
+ goto err;
+ }
+
+ nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
+ if (nmap_dirfd == -1) {
+ close_preserve_errno(omap_dirfd);
+ goto err;
+ }
+
+ /* rename the .virtfs_metadata files */
+ ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name);
+ close_preserve_errno(nmap_dirfd);
+ close_preserve_errno(omap_dirfd);
+ if (ret < 0 && errno != ENOENT) {
+ goto err_undo_rename;
+ }
+
+ ret = 0;
+ }
+ goto out;
+
+ err:
+ ret = -1;
+ err_undo_rename:
+ renameat_preserve_errno(ndirfd, new_name, odirfd, old_name);
+ out:
+ close_preserve_errno(ndirfd);
+ close_preserve_errno(odirfd);
return ret;
}
+ static void v9fs_path_init_dirname(V9fsPath *path, const char *str)
+ {
+ path->data = g_path_get_dirname(str);
+ path->size = strlen(path->data) + 1;
+ }
+
+ static int local_rename(FsContext *ctx, const char *oldpath,
+ const char *newpath)
+ {
+ int err;
+ char *oname = g_path_get_basename(oldpath);
+ char *nname = g_path_get_basename(newpath);
+ V9fsPath olddir, newdir;
+
+ v9fs_path_init_dirname(&olddir, oldpath);
+ v9fs_path_init_dirname(&newdir, newpath);
+
+ err = local_renameat(ctx, &olddir, oname, &newdir, nname);
+
+ v9fs_path_free(&newdir);
+ v9fs_path_free(&olddir);
+ g_free(nname);
+ g_free(oname);
+
+ return err;
+ }
+
static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
const char *name, int flags)
{
int ret;
- V9fsString fullname;
- char *buffer;
-
- v9fs_string_init(&fullname);
+ int dirfd;
- v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
- if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- if (flags == AT_REMOVEDIR) {
- /*
- * If directory remove .virtfs_metadata contained in the
- * directory
- */
- buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
- fullname.data, VIRTFS_META_DIR);
- ret = remove(buffer);
- g_free(buffer);
- if (ret < 0 && errno != ENOENT) {
- /*
- * We didn't had the .virtfs_metadata file. May be file created
- * in non-mapped mode ?. Ignore ENOENT.
- */
- goto err_out;
- }
- }
- /*
- * Now remove the name from parent directory
- * .virtfs_metadata directory.
- */
- buffer = local_mapped_attr_path(ctx, fullname.data);
- ret = remove(buffer);
- g_free(buffer);
- if (ret < 0 && errno != ENOENT) {
- /*
- * We didn't had the .virtfs_metadata file. May be file created
- * in non-mapped mode ?. Ignore ENOENT.
- */
- goto err_out;
- }
+ dirfd = local_opendir_nofollow(ctx, dir->data);
+ if (dirfd == -1) {
+ return -1;
}
- /* Remove the name finally */
- buffer = rpath(ctx, fullname.data);
- ret = remove(buffer);
- g_free(buffer);
- err_out:
- v9fs_string_free(&fullname);
+ ret = local_unlinkat_common(ctx, dirfd, name, flags);
+ close_preserve_errno(dirfd);
return ret;
}
static int local_init(FsContext *ctx)
{
- int err = 0;
struct statfs stbuf;
+ LocalData *data = g_malloc(sizeof(*data));
+
+ data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY);
+ if (data->mountfd == -1) {
+ goto err;
+ }
+
+ #ifdef FS_IOC_GETVERSION
+ /*
+ * use ioc_getversion only if the ioctl is definied
+ */
+ if (fstatfs(data->mountfd, &stbuf) < 0) {
+ close_preserve_errno(data->mountfd);
+ goto err;
+ }
+ switch (stbuf.f_type) {
+ case EXT2_SUPER_MAGIC:
+ case BTRFS_SUPER_MAGIC:
+ case REISERFS_SUPER_MAGIC:
+ case XFS_SUPER_MAGIC:
+ ctx->exops.get_st_gen = local_ioc_getversion;
+ break;
+ }
+ #endif
if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
ctx->xops = passthrough_xattr_ops;
ctx->xops = passthrough_xattr_ops;
}
ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
- #ifdef FS_IOC_GETVERSION
- /*
- * use ioc_getversion only if the iocl is definied
- */
- err = statfs(ctx->fs_root, &stbuf);
- if (!err) {
- switch (stbuf.f_type) {
- case EXT2_SUPER_MAGIC:
- case BTRFS_SUPER_MAGIC:
- case REISERFS_SUPER_MAGIC:
- case XFS_SUPER_MAGIC:
- ctx->exops.get_st_gen = local_ioc_getversion;
- break;
- }
- }
- #endif
- return err;
+
+ ctx->private = data;
+ return 0;
+
+ err:
+ g_free(data);
+ return -1;
+ }
+
+ static void local_cleanup(FsContext *ctx)
+ {
+ LocalData *data = ctx->private;
+
+ close(data->mountfd);
+ g_free(data);
}
static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
{
const char *sec_model = qemu_opt_get(opts, "security_model");
const char *path = qemu_opt_get(opts, "path");
+ Error *err = NULL;
if (!sec_model) {
error_report("Security model not specified, local fs needs security model");
error_report("fsdev: No path specified");
return -1;
}
+
+ fsdev_throttle_parse_opts(opts, &fse->fst, &err);
+ if (err) {
+ error_reportf_err(err, "Throttle configuration is not valid: ");
+ return -1;
+ }
+
fse->path = g_strdup(path);
return 0;
FileOperations local_ops = {
.parse_opts = local_parse_opts,
.init = local_init,
+ .cleanup = local_cleanup,
.lstat = local_lstat,
.readlink = local_readlink,
.close = local_close,
projects / mirror_qemu.git / commitdiff