2.11BSD/sys/sys/kern_subr.c

/*
 * Copyright (c) 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)kern_subr.c	1.2 (2.11BSD GTE) 11/26/94
 */

#include "param.h"
#include "../machine/seg.h"

#include "systm.h"
#include "user.h"
#include "buf.h"
#include "uio.h"

/* copied, for supervisory networking, to sys_net.c */
uiomove(cp, n, uio)
	caddr_t cp;
	u_int n;
	register struct uio *uio;
{
	register struct iovec *iov;
	int error = 0;
	register u_int cnt;

	while (n > 0 && uio->uio_resid) {
		iov = uio->uio_iov;
		cnt = iov->iov_len;
		if (cnt == 0) {
			uio->uio_iov++;
			uio->uio_iovcnt--;
			continue;
		}
		if (cnt > n)
			cnt = n;
		switch (uio->uio_segflg) {

		case UIO_USERSPACE:
			if (cnt > 100 && cp + cnt < SEG6)
				error = uiofmove(cp, cnt, uio, iov);
			else if ((cnt | (int)cp | (int)iov->iov_base) & 1)
				if (uio->uio_rw == UIO_READ)
					error = vcopyout(cp,iov->iov_base, cnt);
				else
					error = vcopyin(iov->iov_base, cp, cnt);
			else {
				if (uio->uio_rw == UIO_READ)
					error = copyout(cp, iov->iov_base, cnt);
				else
					error = copyin(iov->iov_base, cp, cnt);
			}
			if (error)
				return (error);
			break;

		case UIO_USERISPACE:
			if (cnt > 100 && cp + cnt < SEG6)
				error = uiofmove(cp, cnt, uio, iov);
			else if (uio->uio_rw == UIO_READ)
				error = copyiout(cp, iov->iov_base, cnt);
			else
				error = copyiin(iov->iov_base, cp, cnt);
			if (error)
				return (error);
			break;

		case UIO_SYSSPACE:
			if (uio->uio_rw == UIO_READ)
				bcopy((caddr_t)cp, iov->iov_base, cnt);
			else
				bcopy(iov->iov_base, (caddr_t)cp, cnt);
			break;
		}
		iov->iov_base += cnt;
		iov->iov_len -= cnt;
		uio->uio_resid -= cnt;
		uio->uio_offset += cnt;
		cp += cnt;
		n -= cnt;
	}
	return (error);
}

/* copied, for supervisory networking, to sys_net.c */
/*
 * Give next character to user as result of read.
 */
ureadc(c, uio)
	register int c;
	register struct uio *uio;
{
	register struct iovec *iov;

again:
	if (uio->uio_iovcnt == 0)
		panic("ureadc");
	iov = uio->uio_iov;
	if (iov->iov_len == 0 || uio->uio_resid == 0) {
		uio->uio_iovcnt--;
		uio->uio_iov++;
		goto again;
	}
	switch (uio->uio_segflg) {

	case UIO_USERSPACE:
		if (subyte(iov->iov_base, c) < 0)
			return (EFAULT);
		break;

	case UIO_SYSSPACE:
		*iov->iov_base = c;
		break;

	case UIO_USERISPACE:
		if (suibyte(iov->iov_base, c) < 0)
			return (EFAULT);
		break;
	}
	iov->iov_base++;
	iov->iov_len--;
	uio->uio_resid--;
	uio->uio_offset++;
	return (0);
}

/* copied, for supervisory networking, to sys_net.c */
/*
 * Get next character written in by user from uio.
 */
uwritec(uio)
	register struct uio *uio;
{
	register struct iovec *iov;
	register int c;

	if (uio->uio_resid == 0)
		return (-1);
again:
	if (uio->uio_iovcnt <= 0)
		panic("uwritec");
	iov = uio->uio_iov;
	if (iov->iov_len == 0) {
		uio->uio_iov++;
		if (--uio->uio_iovcnt == 0)
			return (-1);
		goto again;
	}
	switch (uio->uio_segflg) {

	case UIO_USERSPACE:
		c = fubyte(iov->iov_base);
		break;

	case UIO_SYSSPACE:
		c = *iov->iov_base & 0377;
		break;

	case UIO_USERISPACE:
		c = fuibyte(iov->iov_base);
		break;
	}
	if (c < 0)
		return (-1);
	iov->iov_base++;
	iov->iov_len--;
	uio->uio_resid--;
	uio->uio_offset++;
	return (c & 0377);
}

/*
 * Copy bytes to/from the kernel and the user.  Uiofmove assumes the kernel
 * area being copied to or from does not overlap segment 6 - the assembly
 * language helper routine, fmove, uses segment register 6 to map in the
 * user's memory.
 */
uiofmove(cp, n, uio, iov)
	caddr_t cp;
	register int n;
	struct uio *uio;
	struct iovec *iov;
{
	register short c;
	short on;
	register short segr;		/* seg register (0 - 7) */
	u_short *segd;			/* PDR map array */
	u_short *sega;			/* PAR map array */
	int error;

#ifdef NONSEPARATE
	segd = UISD;
	sega = UISA;
#else
	if (uio->uio_segflg == UIO_USERSPACE && u.u_sep) {
		segd = UDSD;
		sega = UDSA;
	}
	else {
		segd = UISD;
		sega = UISA;
	}
#endif

	segr = (short)iov->iov_base >> 13 & 07;
	on = (short)iov->iov_base & 017777;
	c = MIN(n, 8192-on);
	for (;;) {
		if (uio->uio_rw == UIO_READ)
			error = fmove(sega[segr], segd[segr], cp, SEG6+on, c);
		else
			error = fmove(sega[segr], segd[segr], SEG6+on, cp, c);
		if (error)
			return(error);
		n -= c;
		if (!n)
			return(0);
		cp += c;
		segr++;
		segr &= 07;
		on = 0;
		c = MIN(n, 8192);
	}
	/*NOTREACHED*/
}