Source to kern/fifo_vnops.c
/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* 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.
*
* @(#)fifo_vnops.c 7.7 (Berkeley) 4/15/91
*/
#include "param.h"
#include "time.h"
#include "namei.h"
#include "vnode.h"
#include "socket.h"
#include "socketvar.h"
#include "stat.h"
#include "systm.h"
#include "ioctl.h"
#include "file.h"
#include "fifo.h"
#include "errno.h"
#include "malloc.h"
/*
* This structure is associated with the FIFO vnode and stores
* the state associated with the FIFO.
*/
struct fifoinfo {
struct socket *fi_readsock;
struct socket *fi_writesock;
long fi_readers;
long fi_writers;
};
struct vnodeops fifo_vnodeops = {
fifo_lookup, /* lookup */
fifo_create, /* create */
fifo_mknod, /* mknod */
fifo_open, /* open */
fifo_close, /* close */
fifo_access, /* access */
fifo_getattr, /* getattr */
fifo_setattr, /* setattr */
fifo_read, /* read */
fifo_write, /* write */
fifo_ioctl, /* ioctl */
fifo_select, /* select */
fifo_mmap, /* mmap */
fifo_fsync, /* fsync */
fifo_seek, /* seek */
fifo_remove, /* remove */
fifo_link, /* link */
fifo_rename, /* rename */
fifo_mkdir, /* mkdir */
fifo_rmdir, /* rmdir */
fifo_symlink, /* symlink */
fifo_readdir, /* readdir */
fifo_readlink, /* readlink */
fifo_abortop, /* abortop */
fifo_inactive, /* inactive */
fifo_reclaim, /* reclaim */
fifo_lock, /* lock */
fifo_unlock, /* unlock */
fifo_bmap, /* bmap */
fifo_strategy, /* strategy */
fifo_print, /* print */
fifo_islocked, /* islocked */
fifo_advlock, /* advlock */
};
/*
* Trivial lookup routine that always fails.
*/
/* ARGSUSED */
fifo_lookup(vp, ndp, p)
struct vnode *vp;
struct nameidata *ndp;
struct proc *p;
{
ndp->ni_dvp = vp;
ndp->ni_vp = NULL;
return (ENOTDIR);
}
/*
* Open called to set up a new instance of a fifo or
* to find an active instance of a fifo.
*/
/* ARGSUSED */
fifo_open(vp, mode, cred, p)
register struct vnode *vp;
int mode;
struct ucred *cred;
struct proc *p;
{
register struct fifoinfo *fip;
struct socket *rso, *wso;
int error;
static char openstr[] = "fifo";
if ((mode & (FREAD|FWRITE)) == (FREAD|FWRITE))
return (EINVAL);
if ((fip = vp->v_fifoinfo) == NULL) {
MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
vp->v_fifoinfo = fip;
if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) {
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
fip->fi_readsock = rso;
if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) {
(void)soclose(rso);
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
fip->fi_writesock = wso;
if (error = unp_connect2(wso, rso)) {
(void)soclose(wso);
(void)soclose(rso);
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
wso->so_state |= SS_CANTRCVMORE;
rso->so_state |= SS_CANTSENDMORE;
}
error = 0;
if (mode & FREAD) {
fip->fi_readers++;
if (fip->fi_readers == 1) {
fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
if (fip->fi_writers > 0)
wakeup((caddr_t)&fip->fi_writers);
}
if (mode & O_NONBLOCK)
return (0);
while (fip->fi_writers == 0)
if (error = tsleep((caddr_t)&fip->fi_readers, PSOCK,
openstr, 0))
break;
} else {
fip->fi_writers++;
if (fip->fi_readers == 0 && (mode & O_NONBLOCK)) {
error = ENXIO;
} else {
if (fip->fi_writers == 1) {
fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
if (fip->fi_readers > 0)
wakeup((caddr_t)&fip->fi_readers);
}
while (fip->fi_readers == 0)
if (error = tsleep((caddr_t)&fip->fi_writers,
PSOCK, openstr, 0))
break;
}
}
if (error)
fifo_close(vp, mode, cred, p);
return (error);
}
/*
* Vnode op for read
*/
/* ARGSUSED */
fifo_read(vp, uio, ioflag, cred)
struct vnode *vp;
register struct uio *uio;
int ioflag;
struct ucred *cred;
{
register struct socket *rso = vp->v_fifoinfo->fi_readsock;
int error, startresid;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("fifo_read mode");
#endif
if (uio->uio_resid == 0)
return (0);
if (ioflag & IO_NDELAY)
rso->so_state |= SS_NBIO;
startresid = uio->uio_resid;
VOP_UNLOCK(vp);
error = soreceive(rso, (struct mbuf **)0, uio, (int *)0,
(struct mbuf **)0, (struct mbuf **)0);
VOP_LOCK(vp);
/*
* Clear EOF indication after first such return.
*/
if (uio->uio_resid == startresid)
rso->so_state &= ~SS_CANTRCVMORE;
if (ioflag & IO_NDELAY)
rso->so_state &= ~SS_NBIO;
return (error);
}
/*
* Vnode op for write
*/
/* ARGSUSED */
fifo_write(vp, uio, ioflag, cred)
struct vnode *vp;
register struct uio *uio;
int ioflag;
struct ucred *cred;
{
struct socket *wso = vp->v_fifoinfo->fi_writesock;
int error;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_WRITE)
panic("fifo_write mode");
#endif
if (ioflag & IO_NDELAY)
wso->so_state |= SS_NBIO;
VOP_UNLOCK(vp);
error = sosend(wso, (struct mbuf *)0, uio, 0, (struct mbuf *)0);
VOP_LOCK(vp);
if (ioflag & IO_NDELAY)
wso->so_state &= ~SS_NBIO;
return (error);
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
fifo_ioctl(vp, com, data, fflag, cred, p)
struct vnode *vp;
int com;
caddr_t data;
int fflag;
struct ucred *cred;
struct proc *p;
{
struct file filetmp;
int error;
if (com == FIONBIO)
return (0);
if (fflag & FREAD)
filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
else
filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
return (soo_ioctl(&filetmp, com, data, p));
}
/* ARGSUSED */
fifo_select(vp, which, fflag, cred, p)
struct vnode *vp;
int which, fflag;
struct ucred *cred;
struct proc *p;
{
struct file filetmp;
int error;
if (fflag & FREAD)
filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
else
filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
return (soo_select(&filetmp, which, p));
}
/*
* This is a noop, simply returning what one has been given.
*/
fifo_bmap(vp, bn, vpp, bnp)
struct vnode *vp;
daddr_t bn;
struct vnode **vpp;
daddr_t *bnp;
{
if (vpp != NULL)
*vpp = vp;
if (bnp != NULL)
*bnp = bn;
return (0);
}
/*
* At the moment we do not do any locking.
*/
/* ARGSUSED */
fifo_lock(vp)
struct vnode *vp;
{
return (0);
}
/* ARGSUSED */
fifo_unlock(vp)
struct vnode *vp;
{
return (0);
}
/*
* Device close routine
*/
/* ARGSUSED */
fifo_close(vp, fflag, cred, p)
register struct vnode *vp;
int fflag;
struct ucred *cred;
struct proc *p;
{
register struct fifoinfo *fip = vp->v_fifoinfo;
int error1, error2;
if (fflag & FWRITE) {
fip->fi_writers--;
if (fip->fi_writers == 0)
socantrcvmore(fip->fi_readsock);
} else {
fip->fi_readers--;
if (fip->fi_readers == 0)
socantsendmore(fip->fi_writesock);
}
if (vp->v_usecount > 1)
return (0);
error1 = soclose(fip->fi_readsock);
error2 = soclose(fip->fi_writesock);
FREE(fip, M_VNODE);
vp->v_fifoinfo = NULL;
if (error1)
return (error1);
return (error2);
}
/*
* Print out the contents of a fifo vnode.
*/
fifo_print(vp)
struct vnode *vp;
{
printf("tag VT_NON");
fifo_printinfo(vp);
printf("\n");
}
/*
* Print out internal contents of a fifo vnode.
*/
fifo_printinfo(vp)
struct vnode *vp;
{
register struct fifoinfo *fip = vp->v_fifoinfo;
printf(", fifo with %d readers and %d writers",
fip->fi_readers, fip->fi_writers);
}
/*
* Fifo failed operation
*/
fifo_ebadf()
{
return (EBADF);
}
/*
* Fifo advisory byte-level locks.
*/
/* ARGSUSED */
fifo_advlock(vp, id, op, fl, flags)
struct vnode *vp;
caddr_t id;
int op;
struct flock *fl;
int flags;
{
return (EOPNOTSUPP);
}
/*
* Fifo bad operation
*/
fifo_badop()
{
panic("fifo_badop called");
/* NOTREACHED */
}