freebsd-dev/sys/kern/kern_subr.c
1995-05-08 23:11:12 +00:00

253 lines
6.1 KiB
C

/*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
* $Id: kern_subr.c,v 1.7 1995/04/30 05:11:46 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/queue.h>
int
uiomove(cp, n, uio)
register caddr_t cp;
register int n;
register struct uio *uio;
{
register struct iovec *iov;
u_int cnt;
int error;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
panic("uiomove: mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("uiomove proc");
#endif
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:
case UIO_USERISPACE:
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_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;
case UIO_NOCOPY:
break;
}
iov->iov_base += cnt;
iov->iov_len -= cnt;
uio->uio_resid -= cnt;
uio->uio_offset += cnt;
cp += cnt;
n -= cnt;
}
return (0);
}
/*
* Give next character to user as result of read.
*/
int
ureadc(c, uio)
register int c;
register struct uio *uio;
{
register struct iovec *iov;
again:
if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
panic("ureadc");
iov = uio->uio_iov;
if (iov->iov_len == 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;
case UIO_NOCOPY:
break;
}
iov->iov_base++;
iov->iov_len--;
uio->uio_resid--;
uio->uio_offset++;
return (0);
}
#ifdef vax /* unused except by ct.c, other oddities XXX */
/*
* Get next character written in by user from uio.
*/
int
uwritec(uio)
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 = *(u_char *) iov->iov_base;
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);
}
#endif /* vax */
/*
* General routine to allocate a hash table.
*/
void *
hashinit(elements, type, hashmask)
int elements, type;
u_long *hashmask;
{
long hashsize;
LIST_HEAD(generic, generic) *hashtbl;
int i;
if (elements <= 0)
panic("hashinit: bad elements");
for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
continue;
hashsize >>= 1;
hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
for (i = 0; i < hashsize; i++)
LIST_INIT(&hashtbl[i]);
*hashmask = hashsize - 1;
return (hashtbl);
}
#define NPRIMES 27
static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
7159, 7673, 8191, 12281, 16381, 24571, 32749 };
/*
* General routine to allocate a prime number sized hash table.
*/
void *
phashinit(elements, type, nentries)
int elements, type;
u_long *nentries;
{
long hashsize;
LIST_HEAD(generic, generic) *hashtbl;
int i;
if (elements <= 0)
panic("phashinit: bad elements");
for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
i++;
if (i == NPRIMES)
break;
hashsize = primes[i];
}
hashsize = primes[i - 1];
hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
for (i = 0; i < hashsize; i++)
LIST_INIT(&hashtbl[i]);
*nentries = hashsize;
return (hashtbl);
}