/* * Virtio 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 "hw/virtio.h" #include "virtio-9p.h" #include "virtio-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 <unistd.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); } 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 = fdopendir(ret); if (!fs->dir) { return -1; } return 0; } static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) { return rewinddir(fs->dir); } static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs) { return telldir(fs->dir); } static int handle_readdir_r(FsContext *ctx, V9fsFidOpenState *fs, struct dirent *entry, struct dirent **result) { return readdir_r(fs->dir, entry, result); } static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) { return seekdir(fs->dir, 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); } 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); } 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[PATH_MAX]; 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 */ dirfd = open(rpath(ctx, ".", buffer), O_DIRECTORY); } 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 */ snprintf(buffer, PATH_MAX, "./%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); 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) { 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)) { return 0; } 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; } 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) { fprintf(stderr, "Invalid argument security_model specified with handle fsdriver\n"); return -1; } if (!path) { fprintf(stderr, "fsdev: No path specified.\n"); 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_r = handle_readdir_r, .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, };