source: rtems/cpukit/libnetworking/kern/kern_subr.c @ 39e6e65a

/*
 * 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
 * $Id$
 */

#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");
#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);
}

#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);
}