retrobsd/sys/kernel/sys_generic.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.
 */
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/inode.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/systm.h>

int selwait;

static void
rwuio (uio)
    register struct uio *uio;
{
    struct a {
        int     fdes;
    };
    register struct file *fp;
    register struct iovec *iov;
    u_int i, count;
    off_t   total;

    GETF(fp, ((struct a *)u.u_arg)->fdes);
    if ((fp->f_flag & (uio->uio_rw == UIO_READ ? FREAD : FWRITE)) == 0) {
        u.u_error = EBADF;
        return;
    }
    total = 0;
    uio->uio_resid = 0;
    for (iov = uio->uio_iov, i = 0; i < uio->uio_iovcnt; i++, iov++)
        total += iov->iov_len;

    uio->uio_resid = total;
    if (uio->uio_resid != total) {      /* check wraparound */
        u.u_error = EINVAL;
        return;
    }
    count = uio->uio_resid;
    if (setjmp (&u.u_qsave)) {
        /*
         * The ONLY way we can get here is via the longjump in sleep.  Thus signals
         * have been checked and u_error set accordingly.  If no bytes have been
         * transferred then all that needs to be done now is 'return'; the system
         * call will either be restarted or reported as interrupted.  If bytes have
         * been transferred then we need to calculate the number of bytes transferred.
         */
        if (uio->uio_resid == count)
            return;
        u.u_error = 0;
    } else
        u.u_error = (*Fops[fp->f_type]->fo_rw) (fp, uio);

    u.u_rval = count - uio->uio_resid;
}

/*
 * Read system call.
 */
void
read()
{
    register struct a {
        int     fdes;
        char    *cbuf;
        unsigned count;
    } *uap = (struct a *)u.u_arg;
    struct uio auio;
    struct iovec aiov;

    aiov.iov_base = (caddr_t)uap->cbuf;
    aiov.iov_len = uap->count;
    auio.uio_iov = &aiov;
    auio.uio_iovcnt = 1;
    auio.uio_rw = UIO_READ;
    rwuio (&auio);
}

void
readv()
{
    register struct a {
        int     fdes;
        struct  iovec *iovp;
        unsigned iovcnt;
    } *uap = (struct a *)u.u_arg;
    struct uio auio;
    struct iovec aiov[16];      /* XXX */

    if (uap->iovcnt > sizeof(aiov)/sizeof(aiov[0])) {
        u.u_error = EINVAL;
        return;
    }
    auio.uio_iov = aiov;
    auio.uio_iovcnt = uap->iovcnt;
    auio.uio_rw = UIO_READ;
    u.u_error = copyin ((caddr_t)uap->iovp, (caddr_t)aiov,
        uap->iovcnt * sizeof (struct iovec));
    if (u.u_error)
        return;
    rwuio (&auio);
}

/*
 * Write system call
 */
void
write()
{
    register struct a {
        int     fdes;
        char    *cbuf;
        unsigned count;
    } *uap = (struct a *)u.u_arg;
    struct uio auio;
    struct iovec aiov;

    auio.uio_iov = &aiov;
    auio.uio_iovcnt = 1;
    auio.uio_rw = UIO_WRITE;
    aiov.iov_base = uap->cbuf;
    aiov.iov_len = uap->count;
    rwuio (&auio);
}

void
writev()
{
    register struct a {
        int     fdes;
        struct  iovec *iovp;
        unsigned iovcnt;
    } *uap = (struct a *)u.u_arg;
    struct uio auio;
    struct iovec aiov[16];      /* XXX */

    if (uap->iovcnt > sizeof(aiov)/sizeof(aiov[0])) {
        u.u_error = EINVAL;
        return;
    }
    auio.uio_iov = aiov;
    auio.uio_iovcnt = uap->iovcnt;
    auio.uio_rw = UIO_WRITE;
    u.u_error = copyin ((caddr_t)uap->iovp, (caddr_t)aiov,
        uap->iovcnt * sizeof (struct iovec));
    if (u.u_error)
        return;
    rwuio (&auio);
}

/*
 * Ioctl system call
 */
void
ioctl()
{
    register struct file *fp;
    register struct a {
        int     fdes;
        long    cmd;
        caddr_t cmarg;
    } *uap;
    u_int com;

    uap = (struct a *)u.u_arg;
    fp = getf(uap->fdes);
    if (! fp)
        return;
    if (! (fp->f_flag & (FREAD | FWRITE))) {
        u.u_error = EBADF;
        return;
    }
    com = (u_int) uap->cmd;
    if (com & (IOC_IN | IOC_OUT)) {
        /* Check user address. */
        u_int nbytes = (com & ~(IOC_INOUT | IOC_VOID)) >> 16;
        if (baduaddr (uap->cmarg) ||
            baduaddr (uap->cmarg + nbytes - 1)) {
            u.u_error = EFAULT;
            return;
        }
    }

    switch (com) {
    case FIOCLEX:
        u.u_pofile[uap->fdes] |= UF_EXCLOSE;
        return;
    case FIONCLEX:
        u.u_pofile[uap->fdes] &= ~UF_EXCLOSE;
        return;
    case FIONBIO:
        u.u_error = fset (fp, FNONBLOCK, *(int*) uap->cmarg);
        return;
    case FIOASYNC:
        u.u_error = fset (fp, FASYNC, *(int*) uap->cmarg);
        return;
    case FIOSETOWN:
        u.u_error = fsetown (fp, *(int*) uap->cmarg);
        return;
    case FIOGETOWN:
        u.u_error = fgetown (fp, (int*) uap->cmarg);
        return;
    }
    u.u_error = (*Fops[fp->f_type]->fo_ioctl) (fp, com, uap->cmarg);
}

int nselcoll;

struct pselect_args {
    int         nd;
    fd_set      *in;
    fd_set      *ou;
    fd_set      *ex;
    struct  timespec *ts;
    sigset_t    *maskp;
};

int
selscan(ibits, obits, nfd, retval)
    fd_set *ibits, *obits;
    int nfd, *retval;
{
    register int i, j, flag = 0;
    fd_mask bits;
    struct file *fp;
    int which, n = 0;

    for (which = 0; which < 3; which++) {
        switch (which) {
        case 0:
            flag = FREAD; break;
        case 1:
            flag = FWRITE; break;
        case 2:
            flag = 0; break;
        }
        for (i = 0; i < nfd; i += NFDBITS) {
            bits = ibits[which].fds_bits[i/NFDBITS];
            while ((j = ffs(bits)) && i + --j < nfd) {
                bits &= ~(1L << j);
                fp = u.u_ofile[i + j];
                if (fp == NULL)
                    return(EBADF);
                if ((*Fops[fp->f_type]->fo_select) (fp, flag)) {
                    FD_SET(i + j, &obits[which]);
                    n++;
                }
            }
        }
    }
    *retval = n;
    return(0);
}

/*
 * Select helper function common to both select() and pselect()
 */
static int
select1(uap, is_pselect)
    register struct pselect_args *uap;
    int is_pselect;
{
    fd_set ibits[3], obits[3];
    struct timeval atv;
    sigset_t sigmsk;
    unsigned int timo = 0;
    register int error, ni;
    int ncoll, s;

    bzero((caddr_t)ibits, sizeof(ibits));
    bzero((caddr_t)obits, sizeof(obits));
    if (uap->nd > NOFILE)
        uap->nd = NOFILE;   /* forgiving, if slightly wrong */
    ni = howmany(uap->nd, NFDBITS);

#define getbits(name, x) \
    if (uap->name) { \
        error = copyin((caddr_t)uap->name, (caddr_t)&ibits[x], \
            (unsigned)(ni * sizeof(fd_mask))); \
        if (error) \
            goto done; \
    }
    getbits(in, 0);
    getbits(ou, 1);
    getbits(ex, 2);
#undef  getbits

    if (uap->maskp) {
        error = copyin ((caddr_t) uap->maskp, (caddr_t) &sigmsk, sizeof(sigmsk));
        sigmsk &= ~sigcantmask;
        if (error)
            goto done;
    }
    if (uap->ts) {
        error = copyin ((caddr_t) uap->ts, (caddr_t) &atv, sizeof (atv));
        if (error)
            goto done;
        /*
         * nanoseconds ('struct timespec') on a PDP-11 are stupid since a 50 or 60 hz
         * clock is all we have.   Keeping the names and logic made porting easier
         * though.
         */
        if (is_pselect) {
            struct  timespec *ts = (struct timespec *)&atv;

            if (ts->tv_sec == 0 && ts->tv_nsec < 1000)
                atv.tv_usec = 1;
            else
                atv.tv_usec = ts->tv_nsec / 1000;
        }
        if (itimerfix(&atv)) {
            error = EINVAL;
            goto done;
        }
        s = splhigh();
        time.tv_usec = lbolt * usechz;
        timevaladd(&atv, &time);
        splx(s);
    }
retry:
    ncoll = nselcoll;
    u.u_procp->p_flag |= P_SELECT;
    error = selscan(ibits, obits, uap->nd, &u.u_rval);
    if (error || u.u_rval)
        goto done;
    s = splhigh();
    if (uap->ts) {
        /* this should be timercmp(&time, &atv, >=) */
        if ((time.tv_sec > atv.tv_sec || (time.tv_sec == atv.tv_sec
            && lbolt * usechz >= atv.tv_usec))) {
            splx(s);
            goto done;
        }
        timo = hzto(&atv);
        if (timo == 0)
            timo = 1;
    }
    if ((u.u_procp->p_flag & P_SELECT) == 0 || nselcoll != ncoll) {
        u.u_procp->p_flag &= ~P_SELECT;
        splx(s);
        goto retry;
    }
    u.u_procp->p_flag &= ~P_SELECT;
    /*
     * If doing a pselect() need to set a temporary mask while in tsleep.
     * Returning from pselect after catching a signal the old mask has to be
     * restored.  Save it here and set the appropriate flag.
     */
    if (uap->maskp) {
        u.u_oldmask = u.u_procp->p_sigmask;
        u.u_psflags |= SAS_OLDMASK;
        u.u_procp->p_sigmask = sigmsk;
    }
    error = tsleep ((caddr_t) &selwait, PSOCK | PCATCH, timo);
    if (uap->maskp)
        u.u_procp->p_sigmask = u.u_oldmask;
    splx(s);
    if (error == 0)
        goto retry;
done:
    u.u_procp->p_flag &= ~P_SELECT;
    /* select is not restarted after signals... */
    if (error == ERESTART)
        error = EINTR;
    if (error == EWOULDBLOCK)
        error = 0;
#define putbits(name, x) \
    if (uap->name && \
        (error2 = copyout ((caddr_t) &obits[x], (caddr_t) uap->name, ni*sizeof(fd_mask)))) \
            error = error2;

    if (error == 0) {
        int error2;

        putbits(in, 0);
        putbits(ou, 1);
        putbits(ex, 2);
#undef putbits
    }
    return(error);
}

/*
 * Select system call.
 */
void
select()
{
    struct uap {
        int     nd;
        fd_set  *in, *ou, *ex;
        struct  timeval *tv;
    } *uap = (struct uap *)u.u_arg;
    register struct pselect_args *pselargs = (struct pselect_args *)uap;

    /*
     * Fake the 6th parameter of pselect.  See the comment below about the
     * number of parameters!
    */
    pselargs->maskp = 0;
    u.u_error = select1 (pselargs, 0);
}

/*
 * pselect (posix select)
 *
 * N.B.  There is only room for 6 arguments - see user.h - so pselect() is
 *       at the maximum!  See user.h
 */
void
pselect()
{
    register struct pselect_args *uap = (struct pselect_args *)u.u_arg;

    u.u_error = select1(uap, 1);
}

/*ARGSUSED*/
int
seltrue(dev, flag)
    dev_t dev;
    int flag;
{
    return (1);
}

void
selwakeup (p, coll)
    register struct proc *p;
    long coll;
{
    if (coll) {
        nselcoll++;
        wakeup ((caddr_t)&selwait);
    }
    if (p) {
        register int s = splhigh();
        if (p->p_wchan == (caddr_t)&selwait) {
            if (p->p_stat == SSLEEP)
                setrun(p);
            else
                unsleep(p);
        } else if (p->p_flag & P_SELECT)
            p->p_flag &= ~P_SELECT;
        splx(s);
    }
}

int
sorw(fp, uio)
    register struct file *fp;
    register struct uio *uio;
{
#ifdef  INET
    if (uio->uio_rw == UIO_READ)
        return(SORECEIVE((struct socket *)fp->f_socket, 0, uio, 0, 0));
    return(SOSEND((struct socket *)fp->f_socket, 0, uio, 0, 0));
#else
    return (EOPNOTSUPP);
#endif
}

int
soctl(fp, com, data)
    struct file *fp;
    u_int   com;
    char    *data;
{
#ifdef  INET
    return (SOO_IOCTL(fp, com, data));
#else
    return (EOPNOTSUPP);
#endif
}

int
sosel(fp, flag)
    struct file *fp;
    int     flag;
{
#ifdef  INET
    return (SOO_SELECT(fp, flag));
#else
    return (EOPNOTSUPP);
#endif
}

int
socls(fp)
    register struct file *fp;
{
    register int error = 0;

#ifdef  INET
    if (fp->f_data)
        error = SOCLOSE((struct socket *)fp->f_data);
    fp->f_data = 0;
#else
    error = EOPNOTSUPP;
#endif
    return(error);
}

/*
 * this is consolidated here rather than being scattered all over the
 * place.  the socketops table has to be in kernel space, but since
 * networking might not be defined an appropriate error has to be set
 */
const struct fileops socketops = {
    sorw, soctl, sosel, socls
};

const struct fileops *const Fops[] = {
    NULL, &inodeops, &socketops, &pipeops
};

/*
 * Routine placed in illegal entries in the bdevsw and cdevsw tables.
 */
void
nostrategy (bp)
    struct buf *bp;
{
    /* Empty. */
}

#ifndef INET
/*
 * socket(2) and socketpair(2) if networking not available.
 */
void
nonet()
{
    u.u_error = EPROTONOSUPPORT;
}
#endif