NetBSD/sys/miscfs/fifofs/fifo_vnops.c

609 lines
15 KiB
C

/* $NetBSD: fifo_vnops.c,v 1.50 2004/07/17 20:53:01 mycroft Exp $ */
/*
* Copyright (c) 1990, 1993, 1995
* 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. 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 8.10 (Berkeley) 5/27/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.50 2004/07/17 20:53:01 mycroft Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/un.h>
#include <sys/poll.h>
#include <sys/event.h>
#include <miscfs/fifofs/fifo.h>
#include <miscfs/genfs/genfs.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;
};
int (**fifo_vnodeop_p) __P((void *));
const struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, fifo_lookup }, /* lookup */
{ &vop_create_desc, fifo_create }, /* create */
{ &vop_mknod_desc, fifo_mknod }, /* mknod */
{ &vop_open_desc, fifo_open }, /* open */
{ &vop_close_desc, fifo_close }, /* close */
{ &vop_access_desc, fifo_access }, /* access */
{ &vop_getattr_desc, fifo_getattr }, /* getattr */
{ &vop_setattr_desc, fifo_setattr }, /* setattr */
{ &vop_read_desc, fifo_read }, /* read */
{ &vop_write_desc, fifo_write }, /* write */
{ &vop_lease_desc, fifo_lease_check }, /* lease */
{ &vop_ioctl_desc, fifo_ioctl }, /* ioctl */
{ &vop_poll_desc, fifo_poll }, /* poll */
{ &vop_kqfilter_desc, fifo_kqfilter }, /* kqfilter */
{ &vop_revoke_desc, fifo_revoke }, /* revoke */
{ &vop_mmap_desc, fifo_mmap }, /* mmap */
{ &vop_fsync_desc, fifo_fsync }, /* fsync */
{ &vop_seek_desc, fifo_seek }, /* seek */
{ &vop_remove_desc, fifo_remove }, /* remove */
{ &vop_link_desc, fifo_link }, /* link */
{ &vop_rename_desc, fifo_rename }, /* rename */
{ &vop_mkdir_desc, fifo_mkdir }, /* mkdir */
{ &vop_rmdir_desc, fifo_rmdir }, /* rmdir */
{ &vop_symlink_desc, fifo_symlink }, /* symlink */
{ &vop_readdir_desc, fifo_readdir }, /* readdir */
{ &vop_readlink_desc, fifo_readlink }, /* readlink */
{ &vop_abortop_desc, fifo_abortop }, /* abortop */
{ &vop_inactive_desc, fifo_inactive }, /* inactive */
{ &vop_reclaim_desc, fifo_reclaim }, /* reclaim */
{ &vop_lock_desc, fifo_lock }, /* lock */
{ &vop_unlock_desc, fifo_unlock }, /* unlock */
{ &vop_bmap_desc, fifo_bmap }, /* bmap */
{ &vop_strategy_desc, fifo_strategy }, /* strategy */
{ &vop_print_desc, fifo_print }, /* print */
{ &vop_islocked_desc, fifo_islocked }, /* islocked */
{ &vop_pathconf_desc, fifo_pathconf }, /* pathconf */
{ &vop_advlock_desc, fifo_advlock }, /* advlock */
{ &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */
{ &vop_valloc_desc, fifo_valloc }, /* valloc */
{ &vop_vfree_desc, fifo_vfree }, /* vfree */
{ &vop_truncate_desc, fifo_truncate }, /* truncate */
{ &vop_update_desc, fifo_update }, /* update */
{ &vop_bwrite_desc, fifo_bwrite }, /* bwrite */
{ &vop_putpages_desc, fifo_putpages }, /* putpages */
{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
};
const struct vnodeopv_desc fifo_vnodeop_opv_desc =
{ &fifo_vnodeop_p, fifo_vnodeop_entries };
/*
* Trivial lookup routine that always fails.
*/
/* ARGSUSED */
int
fifo_lookup(void *v)
{
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap = v;
*ap->a_vpp = NULL;
return (ENOTDIR);
}
/*
* Open called to set up a new instance of a fifo or
* to find an active instance of a fifo.
*/
/* ARGSUSED */
int
fifo_open(void *v)
{
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp;
struct fifoinfo *fip;
struct proc *p;
struct socket *rso, *wso;
int error;
vp = ap->a_vp;
p = ap->a_p;
if ((fip = vp->v_fifoinfo) == NULL) {
MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
vp->v_fifoinfo = fip;
error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, p);
if (error != 0) {
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
fip->fi_readsock = rso;
error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, p);
if (error != 0) {
(void)soclose(rso);
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
fip->fi_writesock = wso;
if ((error = unp_connect2(wso, rso, PRU_CONNECT2)) != 0) {
(void)soclose(wso);
(void)soclose(rso);
free(fip, M_VNODE);
vp->v_fifoinfo = NULL;
return (error);
}
fip->fi_readers = fip->fi_writers = 0;
wso->so_state |= SS_CANTRCVMORE;
rso->so_state |= SS_CANTSENDMORE;
}
if (ap->a_mode & FREAD) {
if (fip->fi_readers++ == 0) {
fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
if (fip->fi_writers > 0)
wakeup(&fip->fi_writers);
}
}
if (ap->a_mode & FWRITE) {
if (fip->fi_writers++ == 0) {
fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
if (fip->fi_readers > 0)
wakeup(&fip->fi_readers);
}
}
if (ap->a_mode & FREAD) {
if (ap->a_mode & O_NONBLOCK) {
} else {
while (!soreadable(fip->fi_readsock) && fip->fi_writers == 0) {
VOP_UNLOCK(vp, 0);
error = tsleep(&fip->fi_readers,
PCATCH | PSOCK, "fifor", 0);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error)
goto bad;
}
}
}
if (ap->a_mode & FWRITE) {
if (ap->a_mode & O_NONBLOCK) {
if (fip->fi_readers == 0) {
error = ENXIO;
goto bad;
}
} else {
while (fip->fi_readers == 0) {
VOP_UNLOCK(vp, 0);
error = tsleep(&fip->fi_writers,
PCATCH | PSOCK, "fifow", 0);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error)
goto bad;
}
}
}
return (0);
bad:
VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p);
return (error);
}
/*
* Vnode op for read
*/
/* ARGSUSED */
int
fifo_read(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap = v;
struct uio *uio;
struct socket *rso;
int error;
size_t startresid;
uio = ap->a_uio;
rso = ap->a_vp->v_fifoinfo->fi_readsock;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("fifo_read mode");
#endif
if (uio->uio_resid == 0)
return (0);
if (ap->a_ioflag & IO_NDELAY)
rso->so_state |= SS_NBIO;
startresid = uio->uio_resid;
VOP_UNLOCK(ap->a_vp, 0);
error = (*rso->so_receive)(rso, (struct mbuf **)0, uio,
(struct mbuf **)0, (struct mbuf **)0, (int *)0);
vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
/*
* Clear EOF indication after first such return.
*/
if (uio->uio_resid == startresid)
rso->so_state &= ~SS_CANTRCVMORE;
if (ap->a_ioflag & IO_NDELAY) {
rso->so_state &= ~SS_NBIO;
if (error == EWOULDBLOCK &&
ap->a_vp->v_fifoinfo->fi_writers == 0)
error = 0;
}
return (error);
}
/*
* Vnode op for write
*/
/* ARGSUSED */
int
fifo_write(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap = v;
struct socket *wso;
int error;
wso = ap->a_vp->v_fifoinfo->fi_writesock;
#ifdef DIAGNOSTIC
if (ap->a_uio->uio_rw != UIO_WRITE)
panic("fifo_write mode");
#endif
if (ap->a_ioflag & IO_NDELAY)
wso->so_state |= SS_NBIO;
VOP_UNLOCK(ap->a_vp, 0);
error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0,
(struct mbuf *)0, 0, curproc /*XXX*/);
vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
if (ap->a_ioflag & IO_NDELAY)
wso->so_state &= ~SS_NBIO;
return (error);
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
int
fifo_ioctl(void *v)
{
struct vop_ioctl_args /* {
struct vnode *a_vp;
u_long a_command;
void *a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
struct file filetmp;
int error;
if (ap->a_command == FIONBIO)
return (0);
if (ap->a_fflag & FREAD) {
filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
if (error)
return (error);
}
if (ap->a_fflag & FWRITE) {
filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
if (error)
return (error);
}
return (0);
}
/* ARGSUSED */
int
fifo_poll(void *v)
{
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
struct proc *a_p;
} */ *ap = v;
struct file filetmp;
int revents;
revents = 0;
if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
if (filetmp.f_data)
revents |= soo_poll(&filetmp, ap->a_events, ap->a_p);
}
if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
if (filetmp.f_data)
revents |= soo_poll(&filetmp, ap->a_events, ap->a_p);
}
return (revents);
}
int
fifo_inactive(void *v)
{
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap = v;
VOP_UNLOCK(ap->a_vp, 0);
return (0);
}
/*
* This is a noop, simply returning what one has been given.
*/
int
fifo_bmap(void *v)
{
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
} */ *ap = v;
if (ap->a_vpp != NULL)
*ap->a_vpp = ap->a_vp;
if (ap->a_bnp != NULL)
*ap->a_bnp = ap->a_bn;
if (ap->a_runp != NULL)
*ap->a_runp = 0;
return (0);
}
/*
* Device close routine
*/
/* ARGSUSED */
int
fifo_close(void *v)
{
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp;
struct fifoinfo *fip;
int isrevoke;
vp = ap->a_vp;
fip = vp->v_fifoinfo;
isrevoke = (ap->a_fflag & (FREAD | FWRITE | FNONBLOCK)) == FNONBLOCK;
if (isrevoke) {
if (fip->fi_readers != 0) {
fip->fi_readers = 0;
socantsendmore(fip->fi_writesock);
}
if (fip->fi_writers != 0) {
fip->fi_writers = 0;
socantrcvmore(fip->fi_readsock);
}
} else {
if ((ap->a_fflag & FREAD) && --fip->fi_readers == 0)
socantsendmore(fip->fi_writesock);
if ((ap->a_fflag & FWRITE) && --fip->fi_writers == 0)
socantrcvmore(fip->fi_readsock);
}
/* Shut down if all readers and writers are gone. */
if ((fip->fi_readers + fip->fi_writers) == 0) {
(void) soclose(fip->fi_readsock);
(void) soclose(fip->fi_writesock);
FREE(fip, M_VNODE);
vp->v_fifoinfo = NULL;
}
return (0);
}
/*
* Print out the contents of a fifo vnode.
*/
int
fifo_print(void *v)
{
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap = v;
printf("tag VT_NON");
fifo_printinfo(ap->a_vp);
printf("\n");
return 0;
}
/*
* Print out internal contents of a fifo vnode.
*/
void
fifo_printinfo(struct vnode *vp)
{
struct fifoinfo *fip;
fip = vp->v_fifoinfo;
printf(", fifo with %ld readers and %ld writers",
fip->fi_readers, fip->fi_writers);
}
/*
* Return POSIX pathconf information applicable to fifo's.
*/
int
fifo_pathconf(void *v)
{
struct vop_pathconf_args /* {
struct vnode *a_vp;
int a_name;
register_t *a_retval;
} */ *ap = v;
switch (ap->a_name) {
case _PC_LINK_MAX:
*ap->a_retval = LINK_MAX;
return (0);
case _PC_PIPE_BUF:
*ap->a_retval = PIPE_BUF;
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
case _PC_SYNC_IO:
*ap->a_retval = 1;
return (0);
default:
return (EINVAL);
}
/* NOTREACHED */
}
static void
filt_fifordetach(struct knote *kn)
{
struct socket *so;
so = (struct socket *)kn->kn_hook;
SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))
so->so_rcv.sb_flags &= ~SB_KNOTE;
}
static int
filt_fiforead(struct knote *kn, long hint)
{
struct socket *so;
so = (struct socket *)kn->kn_hook;
kn->kn_data = so->so_rcv.sb_cc;
if (so->so_state & SS_CANTRCVMORE) {
kn->kn_flags |= EV_EOF;
return (1);
}
kn->kn_flags &= ~EV_EOF;
return (kn->kn_data > 0);
}
static void
filt_fifowdetach(struct knote *kn)
{
struct socket *so;
so = (struct socket *)kn->kn_hook;
SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext);
if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))
so->so_snd.sb_flags &= ~SB_KNOTE;
}
static int
filt_fifowrite(struct knote *kn, long hint)
{
struct socket *so;
so = (struct socket *)kn->kn_hook;
kn->kn_data = sbspace(&so->so_snd);
if (so->so_state & SS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
return (1);
}
kn->kn_flags &= ~EV_EOF;
return (kn->kn_data >= so->so_snd.sb_lowat);
}
static const struct filterops fiforead_filtops =
{ 1, NULL, filt_fifordetach, filt_fiforead };
static const struct filterops fifowrite_filtops =
{ 1, NULL, filt_fifowdetach, filt_fifowrite };
/* ARGSUSED */
int
fifo_kqfilter(void *v)
{
struct vop_kqfilter_args /* {
struct vnode *a_vp;
struct knote *a_kn;
} */ *ap = v;
struct socket *so;
struct sockbuf *sb;
so = (struct socket *)ap->a_vp->v_fifoinfo->fi_readsock;
switch (ap->a_kn->kn_filter) {
case EVFILT_READ:
ap->a_kn->kn_fop = &fiforead_filtops;
sb = &so->so_rcv;
break;
case EVFILT_WRITE:
ap->a_kn->kn_fop = &fifowrite_filtops;
sb = &so->so_snd;
break;
default:
return (1);
}
ap->a_kn->kn_hook = so;
SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, ap->a_kn, kn_selnext);
sb->sb_flags |= SB_KNOTE;
return (0);
}