| /* |
| * 9p handle callback |
| * |
| * Copyright IBM, Corp. 2011 |
| * |
| * Authors: |
| * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "9p.h" |
| #include "9p-xattr.h" |
| #include <arpa/inet.h> |
| #include <pwd.h> |
| #include <grp.h> |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| #include "qemu/xattr.h" |
| #include "qemu/cutils.h" |
| #include "qemu/error-report.h" |
| #include <linux/fs.h> |
| #ifdef CONFIG_LINUX_MAGIC_H |
| #include <linux/magic.h> |
| #endif |
| #include <sys/ioctl.h> |
| |
| #ifndef XFS_SUPER_MAGIC |
| #define XFS_SUPER_MAGIC 0x58465342 |
| #endif |
| #ifndef EXT2_SUPER_MAGIC |
| #define EXT2_SUPER_MAGIC 0xEF53 |
| #endif |
| #ifndef REISERFS_SUPER_MAGIC |
| #define REISERFS_SUPER_MAGIC 0x52654973 |
| #endif |
| #ifndef BTRFS_SUPER_MAGIC |
| #define BTRFS_SUPER_MAGIC 0x9123683E |
| #endif |
| |
| struct handle_data { |
| int mountfd; |
| int handle_bytes; |
| }; |
| |
| static inline int name_to_handle(int dirfd, const char *name, |
| struct file_handle *fh, int *mnt_id, int flags) |
| { |
| return name_to_handle_at(dirfd, name, fh, mnt_id, flags); |
| } |
| |
| static inline int open_by_handle(int mountfd, const char *fh, int flags) |
| { |
| return open_by_handle_at(mountfd, (struct file_handle *)fh, flags); |
| } |
| |
| static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp) |
| { |
| int fd, ret; |
| fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH); |
| if (ret < 0) { |
| goto err_out; |
| } |
| ret = fchmod(fd, credp->fc_mode & 07777); |
| err_out: |
| close(fd); |
| return ret; |
| } |
| |
| |
| static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path, |
| struct stat *stbuf) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_PATH); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH); |
| close(fd); |
| return ret; |
| } |
| |
| static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path, |
| char *buf, size_t bufsz) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_PATH); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = readlinkat(fd, "", buf, bufsz); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_close(FsContext *ctx, V9fsFidOpenState *fs) |
| { |
| return close(fs->fd); |
| } |
| |
| static int handle_closedir(FsContext *ctx, V9fsFidOpenState *fs) |
| { |
| return closedir(fs->dir.stream); |
| } |
| |
| static int handle_open(FsContext *ctx, V9fsPath *fs_path, |
| int flags, V9fsFidOpenState *fs) |
| { |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fs->fd = open_by_handle(data->mountfd, fs_path->data, flags); |
| return fs->fd; |
| } |
| |
| static int handle_opendir(FsContext *ctx, |
| V9fsPath *fs_path, V9fsFidOpenState *fs) |
| { |
| int ret; |
| ret = handle_open(ctx, fs_path, O_DIRECTORY, fs); |
| if (ret < 0) { |
| return -1; |
| } |
| fs->dir.stream = fdopendir(ret); |
| if (!fs->dir.stream) { |
| return -1; |
| } |
| return 0; |
| } |
| |
| static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) |
| { |
| rewinddir(fs->dir.stream); |
| } |
| |
| static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs) |
| { |
| return telldir(fs->dir.stream); |
| } |
| |
| static struct dirent *handle_readdir(FsContext *ctx, V9fsFidOpenState *fs) |
| { |
| return readdir(fs->dir.stream); |
| } |
| |
| static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) |
| { |
| seekdir(fs->dir.stream, off); |
| } |
| |
| static ssize_t handle_preadv(FsContext *ctx, V9fsFidOpenState *fs, |
| const struct iovec *iov, |
| int iovcnt, off_t offset) |
| { |
| #ifdef CONFIG_PREADV |
| return preadv(fs->fd, iov, iovcnt, offset); |
| #else |
| int err = lseek(fs->fd, offset, SEEK_SET); |
| if (err == -1) { |
| return err; |
| } else { |
| return readv(fs->fd, iov, iovcnt); |
| } |
| #endif |
| } |
| |
| static ssize_t handle_pwritev(FsContext *ctx, V9fsFidOpenState *fs, |
| const struct iovec *iov, |
| int iovcnt, off_t offset) |
| { |
| ssize_t ret; |
| #ifdef CONFIG_PREADV |
| ret = pwritev(fs->fd, iov, iovcnt, offset); |
| #else |
| int err = lseek(fs->fd, offset, SEEK_SET); |
| if (err == -1) { |
| return err; |
| } else { |
| ret = writev(fs->fd, iov, iovcnt); |
| } |
| #endif |
| #ifdef CONFIG_SYNC_FILE_RANGE |
| if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { |
| /* |
| * Initiate a writeback. This is not a data integrity sync. |
| * We want to ensure that we don't leave dirty pages in the cache |
| * after write when writeout=immediate is sepcified. |
| */ |
| sync_file_range(fs->fd, offset, ret, |
| SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); |
| } |
| #endif |
| return ret; |
| } |
| |
| static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fchmod(fd, credp->fc_mode); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path, |
| const char *name, FsCred *credp) |
| { |
| int dirfd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH); |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev); |
| if (!ret) { |
| ret = handle_update_file_cred(dirfd, name, credp); |
| } |
| close(dirfd); |
| return ret; |
| } |
| |
| static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, |
| const char *name, FsCred *credp) |
| { |
| int dirfd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH); |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| ret = mkdirat(dirfd, name, credp->fc_mode); |
| if (!ret) { |
| ret = handle_update_file_cred(dirfd, name, credp); |
| } |
| close(dirfd); |
| return ret; |
| } |
| |
| static int handle_fstat(FsContext *fs_ctx, int fid_type, |
| V9fsFidOpenState *fs, struct stat *stbuf) |
| { |
| int fd; |
| |
| if (fid_type == P9_FID_DIR) { |
| fd = dirfd(fs->dir.stream); |
| } else { |
| fd = fs->fd; |
| } |
| return fstat(fd, stbuf); |
| } |
| |
| static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, |
| int flags, FsCred *credp, V9fsFidOpenState *fs) |
| { |
| int ret; |
| int dirfd, fd; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH); |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode); |
| if (fd >= 0) { |
| ret = handle_update_file_cred(dirfd, name, credp); |
| if (ret < 0) { |
| close(fd); |
| fd = ret; |
| } else { |
| fs->fd = fd; |
| } |
| } |
| close(dirfd); |
| return fd; |
| } |
| |
| |
| static int handle_symlink(FsContext *fs_ctx, const char *oldpath, |
| V9fsPath *dir_path, const char *name, FsCred *credp) |
| { |
| int fd, dirfd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH); |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| ret = symlinkat(oldpath, dirfd, name); |
| if (!ret) { |
| fd = openat(dirfd, name, O_PATH | O_NOFOLLOW); |
| if (fd < 0) { |
| ret = fd; |
| goto err_out; |
| } |
| ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH); |
| close(fd); |
| } |
| err_out: |
| close(dirfd); |
| return ret; |
| } |
| |
| static int handle_link(FsContext *ctx, V9fsPath *oldpath, |
| V9fsPath *dirpath, const char *name) |
| { |
| int oldfd, newdirfd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH); |
| if (oldfd < 0) { |
| return oldfd; |
| } |
| newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH); |
| if (newdirfd < 0) { |
| close(oldfd); |
| return newdirfd; |
| } |
| ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH); |
| close(newdirfd); |
| close(oldfd); |
| return ret; |
| } |
| |
| static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = ftruncate(fd, size); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_rename(FsContext *ctx, const char *oldpath, |
| const char *newpath) |
| { |
| errno = EOPNOTSUPP; |
| return -1; |
| } |
| |
| static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)fs_ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_PATH); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path, |
| const struct timespec *buf) |
| { |
| int ret; |
| #ifdef CONFIG_UTIMENSAT |
| int fd; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = futimens(fd, buf); |
| close(fd); |
| #else |
| ret = -1; |
| errno = ENOSYS; |
| #endif |
| return ret; |
| } |
| |
| static int handle_remove(FsContext *ctx, const char *path) |
| { |
| errno = EOPNOTSUPP; |
| return -1; |
| } |
| |
| static int handle_fsync(FsContext *ctx, int fid_type, |
| V9fsFidOpenState *fs, int datasync) |
| { |
| int fd; |
| |
| if (fid_type == P9_FID_DIR) { |
| fd = dirfd(fs->dir.stream); |
| } else { |
| fd = fs->fd; |
| } |
| |
| if (datasync) { |
| return qemu_fdatasync(fd); |
| } else { |
| return fsync(fd); |
| } |
| } |
| |
| static int handle_statfs(FsContext *ctx, V9fsPath *fs_path, |
| struct statfs *stbuf) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fstatfs(fd, stbuf); |
| close(fd); |
| return ret; |
| } |
| |
| static ssize_t handle_lgetxattr(FsContext *ctx, V9fsPath *fs_path, |
| const char *name, void *value, size_t size) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fgetxattr(fd, name, value, size); |
| close(fd); |
| return ret; |
| } |
| |
| static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path, |
| void *value, size_t size) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = flistxattr(fd, value, size); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name, |
| void *value, size_t size, int flags) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fsetxattr(fd, name, value, size, flags); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path, |
| const char *name) |
| { |
| int fd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK); |
| if (fd < 0) { |
| return fd; |
| } |
| ret = fremovexattr(fd, name); |
| close(fd); |
| return ret; |
| } |
| |
| static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path, |
| const char *name, V9fsPath *target) |
| { |
| char *buffer; |
| struct file_handle *fh; |
| int dirfd, ret, mnt_id; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| /* "." and ".." are not allowed */ |
| if (!strcmp(name, ".") || !strcmp(name, "..")) { |
| errno = EINVAL; |
| return -1; |
| |
| } |
| if (dir_path) { |
| dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH); |
| } else { |
| /* relative to export root */ |
| buffer = rpath(ctx, "."); |
| dirfd = open(buffer, O_DIRECTORY); |
| g_free(buffer); |
| } |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes); |
| fh->handle_bytes = data->handle_bytes; |
| /* add a "./" at the beginning of the path */ |
| buffer = g_strdup_printf("./%s", name); |
| /* flag = 0 imply don't follow symlink */ |
| ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0); |
| if (!ret) { |
| target->data = (char *)fh; |
| target->size = sizeof(struct file_handle) + data->handle_bytes; |
| } else { |
| g_free(fh); |
| } |
| close(dirfd); |
| g_free(buffer); |
| return ret; |
| } |
| |
| static int handle_renameat(FsContext *ctx, V9fsPath *olddir, |
| const char *old_name, V9fsPath *newdir, |
| const char *new_name) |
| { |
| int olddirfd, newdirfd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| |
| olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH); |
| if (olddirfd < 0) { |
| return olddirfd; |
| } |
| newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH); |
| if (newdirfd < 0) { |
| close(olddirfd); |
| return newdirfd; |
| } |
| ret = renameat(olddirfd, old_name, newdirfd, new_name); |
| close(newdirfd); |
| close(olddirfd); |
| return ret; |
| } |
| |
| static int handle_unlinkat(FsContext *ctx, V9fsPath *dir, |
| const char *name, int flags) |
| { |
| int dirfd, ret; |
| struct handle_data *data = (struct handle_data *)ctx->private; |
| int rflags; |
| |
| dirfd = open_by_handle(data->mountfd, dir->data, O_PATH); |
| if (dirfd < 0) { |
| return dirfd; |
| } |
| |
| rflags = 0; |
| if (flags & P9_DOTL_AT_REMOVEDIR) { |
| rflags |= AT_REMOVEDIR; |
| } |
| |
| ret = unlinkat(dirfd, name, rflags); |
| |
| close(dirfd); |
| return ret; |
| } |
| |
| static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path, |
| mode_t st_mode, uint64_t *st_gen) |
| { |
| #ifdef FS_IOC_GETVERSION |
| int err; |
| V9fsFidOpenState fid_open; |
| |
| /* |
| * Do not try to open special files like device nodes, fifos etc |
| * We can get fd for regular files and directories only |
| */ |
| if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { |
| errno = ENOTTY; |
| return -1; |
| } |
| err = handle_open(ctx, path, O_RDONLY, &fid_open); |
| if (err < 0) { |
| return err; |
| } |
| err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); |
| handle_close(ctx, &fid_open); |
| return err; |
| #else |
| errno = ENOTTY; |
| return -1; |
| #endif |
| } |
| |
| static int handle_init(FsContext *ctx) |
| { |
| int ret, mnt_id; |
| struct statfs stbuf; |
| struct file_handle fh; |
| struct handle_data *data = g_malloc(sizeof(struct handle_data)); |
| |
| data->mountfd = open(ctx->fs_root, O_DIRECTORY); |
| if (data->mountfd < 0) { |
| ret = data->mountfd; |
| goto err_out; |
| } |
| ret = statfs(ctx->fs_root, &stbuf); |
| if (!ret) { |
| 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 = handle_ioc_getversion; |
| break; |
| } |
| } |
| memset(&fh, 0, sizeof(struct file_handle)); |
| ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0); |
| if (ret && errno == EOVERFLOW) { |
| data->handle_bytes = fh.handle_bytes; |
| ctx->private = data; |
| ret = 0; |
| goto out; |
| } |
| /* we got 0 byte handle ? */ |
| ret = -1; |
| close(data->mountfd); |
| err_out: |
| g_free(data); |
| out: |
| return ret; |
| } |
| |
| static int handle_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"); |
| |
| if (sec_model) { |
| error_report("Invalid argument security_model specified with handle fsdriver"); |
| return -1; |
| } |
| |
| if (!path) { |
| error_report("fsdev: No path specified"); |
| return -1; |
| } |
| fse->path = g_strdup(path); |
| return 0; |
| |
| } |
| |
| FileOperations handle_ops = { |
| .parse_opts = handle_parse_opts, |
| .init = handle_init, |
| .lstat = handle_lstat, |
| .readlink = handle_readlink, |
| .close = handle_close, |
| .closedir = handle_closedir, |
| .open = handle_open, |
| .opendir = handle_opendir, |
| .rewinddir = handle_rewinddir, |
| .telldir = handle_telldir, |
| .readdir = handle_readdir, |
| .seekdir = handle_seekdir, |
| .preadv = handle_preadv, |
| .pwritev = handle_pwritev, |
| .chmod = handle_chmod, |
| .mknod = handle_mknod, |
| .mkdir = handle_mkdir, |
| .fstat = handle_fstat, |
| .open2 = handle_open2, |
| .symlink = handle_symlink, |
| .link = handle_link, |
| .truncate = handle_truncate, |
| .rename = handle_rename, |
| .chown = handle_chown, |
| .utimensat = handle_utimensat, |
| .remove = handle_remove, |
| .fsync = handle_fsync, |
| .statfs = handle_statfs, |
| .lgetxattr = handle_lgetxattr, |
| .llistxattr = handle_llistxattr, |
| .lsetxattr = handle_lsetxattr, |
| .lremovexattr = handle_lremovexattr, |
| .name_to_path = handle_name_to_path, |
| .renameat = handle_renameat, |
| .unlinkat = handle_unlinkat, |
| }; |