vnode must now be locked when calling VOP_OPEN

[unix-history] / usr / src / sys / kern / tty_tty.c

/*-
* Copyright (c) 1982, 1986, 1991 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*
*      @(#)tty_tty.c   7.15 (Berkeley) %G%
*/

/*
* Indirect driver for controlling tty.
*/
#include "param.h"
#include "systm.h"
#include "conf.h"
#include "ioctl.h"
#include "tty.h"
#include "proc.h"
#include "vnode.h"
#include "file.h"

#define cttyvp(p) ((p)->p_flag&SCTTY ? (p)->p_session->s_ttyvp : NULL)

/*ARGSUSED*/
cttyopen(dev, flag, mode, p)
       dev_t dev;
       int flag, mode;
       struct proc *p;
{
       struct vnode *ttyvp = cttyvp(p);
       int error;

       if (ttyvp == NULL)
               return (ENXIO);
       VOP_LOCK(ttyvp);
       error = VOP_ACCESS(ttyvp,
         (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
       if (!error)
               error = VOP_OPEN(ttyvp, flag, NOCRED, p);
       VOP_UNLOCK(ttyvp);
       return (error);
}

/*ARGSUSED*/
cttyread(dev, uio, flag)
       dev_t dev;
       struct uio *uio;
{
       register struct vnode *ttyvp = cttyvp(uio->uio_procp);
       int error;

       if (ttyvp == NULL)
               return (EIO);
       VOP_LOCK(ttyvp);
       error = VOP_READ(ttyvp, uio, flag, NOCRED);
       VOP_UNLOCK(ttyvp);
       return (error);
}

/*ARGSUSED*/
cttywrite(dev, uio, flag)
       dev_t dev;
       struct uio *uio;
{
       register struct vnode *ttyvp = cttyvp(uio->uio_procp);
       int error;

       if (ttyvp == NULL)
               return (EIO);
       VOP_LOCK(ttyvp);
       error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
       VOP_UNLOCK(ttyvp);
       return (error);
}

/*ARGSUSED*/
cttyioctl(dev, cmd, addr, flag, p)
       dev_t dev;
       int cmd;
       caddr_t addr;
       int flag;
       struct proc *p;
{
       struct vnode *ttyvp = cttyvp(p);

       if (ttyvp == NULL)
               return (EIO);
       if (cmd == TIOCNOTTY) {
               if (!SESS_LEADER(p)) {
                       p->p_flag &= ~SCTTY;
                       return (0);
               } else
                       return (EINVAL);
       }
       return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
}

/*ARGSUSED*/
cttyselect(dev, flag, p)
       dev_t dev;
       int flag;
       struct proc *p;
{
       struct vnode *ttyvp = cttyvp(p);

       if (ttyvp == NULL)
               return (1);     /* try operation to get EOF/failure */
       return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
}