fdesc_vnops.c

来自「早期freebsd实现」· C语言 代码 · 共 975 行 · 第 1/2 页

	/*
	 * Can't mess with the root vnode
	 */
	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fdesc:
		break;

	case Fctty:
		return (0);

	default:
		return (EACCES);
	}

	fd = VTOFDESC(ap->a_vp)->fd_fd;
	if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) {
		return (EBADF);
	}

	/*
	 * Can setattr the underlying vnode, but not sockets!
	 */
	switch (fp->f_type) {
	case DTYPE_VNODE:
		error = VOP_SETATTR((struct vnode *) fp->f_data, ap->a_vap, ap->a_cred, ap->a_p);
		break;

	case DTYPE_SOCKET:
		error = 0;
		break;

	default:
		panic("fdesc setattr");
		break;
	}

	return (error);
}

#define UIO_MX 16

static struct dirtmp {
	u_long d_fileno;
	u_short d_reclen;
	u_short d_namlen;
	char d_name[8];
} rootent[] = {
	{ FD_DEVFD, UIO_MX, 2, "fd" },
	{ FD_STDIN, UIO_MX, 5, "stdin" },
	{ FD_STDOUT, UIO_MX, 6, "stdout" },
	{ FD_STDERR, UIO_MX, 6, "stderr" },
	{ FD_CTTY, UIO_MX, 3, "tty" },
	{ 0 }
};

int
fdesc_readdir(ap)
	struct vop_readdir_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		struct ucred *a_cred;
	} */ *ap;
{
	struct uio *uio = ap->a_uio;
	struct filedesc *fdp;
	int i;
	int error;

	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fctty:
		return (0);

	case Fdesc:
		return (ENOTDIR);

	default:
		break;
	}

	fdp = uio->uio_procp->p_fd;

	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
		struct dirent d;
		struct dirent *dp = &d;
		struct dirtmp *dt;

		i = uio->uio_offset / UIO_MX;
		error = 0;

		while (uio->uio_resid > 0) {
			dt = &rootent[i];
			if (dt->d_fileno == 0) {
				/**eofflagp = 1;*/
				break;
			}
			i++;
			
			switch (dt->d_fileno) {
			case FD_CTTY:
				if (cttyvp(uio->uio_procp) == NULL)
					continue;
				break;

			case FD_STDIN:
			case FD_STDOUT:
			case FD_STDERR:
				if ((dt->d_fileno-FD_STDIN) >= fdp->fd_nfiles)
					continue;
				if (fdp->fd_ofiles[dt->d_fileno-FD_STDIN] == NULL)
					continue;
				break;
			}
			bzero((caddr_t) dp, UIO_MX);
			dp->d_fileno = dt->d_fileno;
			dp->d_namlen = dt->d_namlen;
			dp->d_type = DT_UNKNOWN;
			dp->d_reclen = dt->d_reclen;
			bcopy(dt->d_name, dp->d_name, dp->d_namlen+1);
			error = uiomove((caddr_t) dp, UIO_MX, uio);
			if (error)
				break;
		}
		uio->uio_offset = i * UIO_MX;
		return (error);
	}

	i = uio->uio_offset / UIO_MX;
	error = 0;
	while (uio->uio_resid > 0) {
		if (i >= fdp->fd_nfiles)
			break;

		if (fdp->fd_ofiles[i] != NULL) {
			struct dirent d;
			struct dirent *dp = &d;

			bzero((caddr_t) dp, UIO_MX);

			dp->d_namlen = sprintf(dp->d_name, "%d", i);
			dp->d_reclen = UIO_MX;
			dp->d_type = DT_UNKNOWN;
			dp->d_fileno = i + FD_STDIN;
			/*
			 * And ship to userland
			 */
			error = uiomove((caddr_t) dp, UIO_MX, uio);
			if (error)
				break;
		}
		i++;
	}

	uio->uio_offset = i * UIO_MX;
	return (error);
}

int
fdesc_readlink(ap)
	struct vop_readlink_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		struct ucred *a_cred;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	int error;

	if (vp->v_type != VLNK)
		return (EPERM);

	if (VTOFDESC(vp)->fd_type == Flink) {
		char *ln = VTOFDESC(vp)->fd_link;
		error = uiomove(ln, strlen(ln), ap->a_uio);
	} else {
		error = EOPNOTSUPP;
	}

	return (error);
}

int
fdesc_read(ap)
	struct vop_read_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	int error = EOPNOTSUPP;

	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fctty:
		error = cttyread(devctty, ap->a_uio, ap->a_ioflag);
		break;

	default:
		error = EOPNOTSUPP;
		break;
	}
	
	return (error);
}

int
fdesc_write(ap)
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	int error = EOPNOTSUPP;

	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fctty:
		error = cttywrite(devctty, ap->a_uio, ap->a_ioflag);
		break;

	default:
		error = EOPNOTSUPP;
		break;
	}
	
	return (error);
}

int
fdesc_ioctl(ap)
	struct vop_ioctl_args /* {
		struct vnode *a_vp;
		int  a_command;
		caddr_t  a_data;
		int  a_fflag;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{
	int error = EOPNOTSUPP;

	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fctty:
		error = cttyioctl(devctty, ap->a_command, ap->a_data,
					ap->a_fflag, ap->a_p);
		break;

	default:
		error = EOPNOTSUPP;
		break;
	}
	
	return (error);
}

int
fdesc_select(ap)
	struct vop_select_args /* {
		struct vnode *a_vp;
		int  a_which;
		int  a_fflags;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{
	int error = EOPNOTSUPP;

	switch (VTOFDESC(ap->a_vp)->fd_type) {
	case Fctty:
		error = cttyselect(devctty, ap->a_fflags, ap->a_p);
		break;

	default:
		error = EOPNOTSUPP;
		break;
	}
	
	return (error);
}

int
fdesc_inactive(ap)
	struct vop_inactive_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;

	/*
	 * Clear out the v_type field to avoid
	 * nasty things happening in vgone().
	 */
	vp->v_type = VNON;
	return (0);
}

int
fdesc_reclaim(ap)
	struct vop_reclaim_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;

	remque(VTOFDESC(vp));
	FREE(vp->v_data, M_TEMP);
	vp->v_data = 0;

	return (0);
}

/*
 * Return POSIX pathconf information applicable to special devices.
 */
fdesc_pathconf(ap)
	struct vop_pathconf_args /* {
		struct vnode *a_vp;
		int a_name;
		int *a_retval;
	} */ *ap;
{

	switch (ap->a_name) {
	case _PC_LINK_MAX:
		*ap->a_retval = LINK_MAX;
		return (0);
	case _PC_MAX_CANON:
		*ap->a_retval = MAX_CANON;
		return (0);
	case _PC_MAX_INPUT:
		*ap->a_retval = MAX_INPUT;
		return (0);
	case _PC_PIPE_BUF:
		*ap->a_retval = PIPE_BUF;
		return (0);
	case _PC_CHOWN_RESTRICTED:
		*ap->a_retval = 1;
		return (0);
	case _PC_VDISABLE:
		*ap->a_retval = _POSIX_VDISABLE;
		return (0);
	default:
		return (EINVAL);
	}
	/* NOTREACHED */
}

/*
 * Print out the contents of a /dev/fd vnode.
 */
/* ARGSUSED */
int
fdesc_print(ap)
	struct vop_print_args /* {
		struct vnode *a_vp;
	} */ *ap;
{

	printf("tag VT_NON, fdesc vnode\n");
	return (0);
}

/*void*/
int
fdesc_vfree(ap)
	struct vop_vfree_args /* {
		struct vnode *a_pvp;
		ino_t a_ino;
		int a_mode;
	} */ *ap;
{

	return (0);
}

/*
 * /dev/fd vnode unsupported operation
 */
int
fdesc_enotsupp()
{

	return (EOPNOTSUPP);
}

/*
 * /dev/fd "should never get here" operation
 */
int
fdesc_badop()
{

	panic("fdesc: bad op");
	/* NOTREACHED */
}

/*
 * /dev/fd vnode null operation
 */
int
fdesc_nullop()
{

	return (0);
}

#define fdesc_create ((int (*) __P((struct  vop_create_args *)))fdesc_enotsupp)
#define fdesc_mknod ((int (*) __P((struct  vop_mknod_args *)))fdesc_enotsupp)
#define fdesc_close ((int (*) __P((struct  vop_close_args *)))nullop)
#define fdesc_access ((int (*) __P((struct  vop_access_args *)))nullop)
#define fdesc_mmap ((int (*) __P((struct  vop_mmap_args *)))fdesc_enotsupp)
#define fdesc_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
#define fdesc_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
#define fdesc_remove ((int (*) __P((struct  vop_remove_args *)))fdesc_enotsupp)
#define fdesc_link ((int (*) __P((struct  vop_link_args *)))fdesc_enotsupp)
#define fdesc_rename ((int (*) __P((struct  vop_rename_args *)))fdesc_enotsupp)
#define fdesc_mkdir ((int (*) __P((struct  vop_mkdir_args *)))fdesc_enotsupp)
#define fdesc_rmdir ((int (*) __P((struct  vop_rmdir_args *)))fdesc_enotsupp)
#define fdesc_symlink ((int (*) __P((struct vop_symlink_args *)))fdesc_enotsupp)
#define fdesc_abortop ((int (*) __P((struct  vop_abortop_args *)))nullop)
#define fdesc_lock ((int (*) __P((struct  vop_lock_args *)))nullop)
#define fdesc_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
#define fdesc_bmap ((int (*) __P((struct  vop_bmap_args *)))fdesc_badop)
#define fdesc_strategy ((int (*) __P((struct  vop_strategy_args *)))fdesc_badop)
#define fdesc_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
#define fdesc_advlock ((int (*) __P((struct vop_advlock_args *)))fdesc_enotsupp)
#define fdesc_blkatoff \
	((int (*) __P((struct  vop_blkatoff_args *)))fdesc_enotsupp)
#define fdesc_vget ((int (*) __P((struct  vop_vget_args *)))fdesc_enotsupp)
#define fdesc_valloc ((int(*) __P(( \
		struct vnode *pvp, \
		int mode, \
		struct ucred *cred, \
		struct vnode **vpp))) fdesc_enotsupp)
#define fdesc_truncate \
	((int (*) __P((struct  vop_truncate_args *)))fdesc_enotsupp)
#define fdesc_update ((int (*) __P((struct  vop_update_args *)))fdesc_enotsupp)
#define fdesc_bwrite ((int (*) __P((struct  vop_bwrite_args *)))fdesc_enotsupp)

int (**fdesc_vnodeop_p)();
struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
	{ &vop_default_desc, vn_default_error },
	{ &vop_lookup_desc, fdesc_lookup },	/* lookup */
	{ &vop_create_desc, fdesc_create },	/* create */
	{ &vop_mknod_desc, fdesc_mknod },	/* mknod */
	{ &vop_open_desc, fdesc_open },		/* open */
	{ &vop_close_desc, fdesc_close },	/* close */
	{ &vop_access_desc, fdesc_access },	/* access */
	{ &vop_getattr_desc, fdesc_getattr },	/* getattr */
	{ &vop_setattr_desc, fdesc_setattr },	/* setattr */
	{ &vop_read_desc, fdesc_read },		/* read */
	{ &vop_write_desc, fdesc_write },	/* write */
	{ &vop_ioctl_desc, fdesc_ioctl },	/* ioctl */
	{ &vop_select_desc, fdesc_select },	/* select */
	{ &vop_mmap_desc, fdesc_mmap },		/* mmap */
	{ &vop_fsync_desc, fdesc_fsync },	/* fsync */
	{ &vop_seek_desc, fdesc_seek },		/* seek */
	{ &vop_remove_desc, fdesc_remove },	/* remove */
	{ &vop_link_desc, fdesc_link },		/* link */
	{ &vop_rename_desc, fdesc_rename },	/* rename */
	{ &vop_mkdir_desc, fdesc_mkdir },	/* mkdir */
	{ &vop_rmdir_desc, fdesc_rmdir },	/* rmdir */
	{ &vop_symlink_desc, fdesc_symlink },	/* symlink */
	{ &vop_readdir_desc, fdesc_readdir },	/* readdir */
	{ &vop_readlink_desc, fdesc_readlink },	/* readlink */
	{ &vop_abortop_desc, fdesc_abortop },	/* abortop */
	{ &vop_inactive_desc, fdesc_inactive },	/* inactive */
	{ &vop_reclaim_desc, fdesc_reclaim },	/* reclaim */
	{ &vop_lock_desc, fdesc_lock },		/* lock */
	{ &vop_unlock_desc, fdesc_unlock },	/* unlock */
	{ &vop_bmap_desc, fdesc_bmap },		/* bmap */
	{ &vop_strategy_desc, fdesc_strategy },	/* strategy */
	{ &vop_print_desc, fdesc_print },	/* print */
	{ &vop_islocked_desc, fdesc_islocked },	/* islocked */
	{ &vop_pathconf_desc, fdesc_pathconf },	/* pathconf */
	{ &vop_advlock_desc, fdesc_advlock },	/* advlock */
	{ &vop_blkatoff_desc, fdesc_blkatoff },	/* blkatoff */
	{ &vop_valloc_desc, fdesc_valloc },	/* valloc */
	{ &vop_vfree_desc, fdesc_vfree },	/* vfree */
	{ &vop_truncate_desc, fdesc_truncate },	/* truncate */
	{ &vop_update_desc, fdesc_update },	/* update */
	{ &vop_bwrite_desc, fdesc_bwrite },	/* bwrite */
	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
};
struct vnodeopv_desc fdesc_vnodeop_opv_desc =
	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };