NetBSD/sys/kern/sys_socket.c
wrstuden 16029d56b5 Add support for FIONWRITE and FIONSPACE ioctls. FIONWRITE reports
the number of bytes in the send queue, and FIONSPACE reports the
number of free bytes in the send queue. These ioctls permit applications
to monitor file descriptor transmission dynamics.

In examining prior art, FIONWRITE exists with the semantics given
here. FIONSPACE is provided so that programs may easily determine how
much space is left in the send queue; they do not need to know the
send queue size.

The fact that a write may block even if there is enough space in the
send queue for it is noted in the documentation.

FIONWRITE functionality may be used to implement TIOCOUTQ for Linux
emulation - Linux extended this ioctl to sockets, even though they are
not ttys.
2004-11-06 02:03:20 +00:00

242 lines
6.0 KiB
C

/* $NetBSD: sys_socket.c,v 1.41 2004/11/06 02:03:20 wrstuden Exp $ */
/*
* Copyright (c) 1982, 1986, 1990, 1993
* 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.
*
* @(#)sys_socket.c 8.3 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_socket.c,v 1.41 2004/11/06 02:03:20 wrstuden Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/route.h>
struct fileops socketops = {
soo_read, soo_write, soo_ioctl, soo_fcntl, soo_poll,
soo_stat, soo_close, soo_kqfilter
};
/* ARGSUSED */
int
soo_read(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
{
struct socket *so = (struct socket *) fp->f_data;
return ((*so->so_receive)(so, (struct mbuf **)0,
uio, (struct mbuf **)0, (struct mbuf **)0, (int *)0));
}
/* ARGSUSED */
int
soo_write(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
{
struct socket *so = (struct socket *) fp->f_data;
return ((*so->so_send)(so, (struct mbuf *)0,
uio, (struct mbuf *)0, (struct mbuf *)0, 0, uio->uio_procp));
}
int
soo_ioctl(fp, cmd, data, p)
struct file *fp;
u_long cmd;
void *data;
struct proc *p;
{
struct socket *so = (struct socket *)fp->f_data;
switch (cmd) {
case FIONBIO:
if (*(int *)data)
so->so_state |= SS_NBIO;
else
so->so_state &= ~SS_NBIO;
return (0);
case FIOASYNC:
if (*(int *)data) {
so->so_state |= SS_ASYNC;
so->so_rcv.sb_flags |= SB_ASYNC;
so->so_snd.sb_flags |= SB_ASYNC;
} else {
so->so_state &= ~SS_ASYNC;
so->so_rcv.sb_flags &= ~SB_ASYNC;
so->so_snd.sb_flags &= ~SB_ASYNC;
}
return (0);
case FIONREAD:
*(int *)data = so->so_rcv.sb_cc;
return (0);
case FIONWRITE:
*(int *)data = so->so_snd.sb_cc;
return (0);
case FIONSPACE:
/*
* See the comment around sbspace()'s definition
* in sys/socketvar.h in face of counts about maximum
* to understand the following test. We detect overflow
* and return zero.
*/
if ((so->snd.sb_hiwat < so->snd.sb_cc)
|| (so->snd.sb_mbmax < so->snd.sb_mbcnt))
*(int *)data = 0;
else
*(int *)data = sbspace(so->so_snd);
return (0);
case SIOCSPGRP:
case FIOSETOWN:
case TIOCSPGRP:
return fsetown(p, &so->so_pgid, cmd, data);
case SIOCGPGRP:
case FIOGETOWN:
case TIOCGPGRP:
return fgetown(p, so->so_pgid, cmd, data);
case SIOCATMARK:
*(int *)data = (so->so_state&SS_RCVATMARK) != 0;
return (0);
}
/*
* Interface/routing/protocol specific ioctls:
* interface and routing ioctls should have a
* different entry since a socket's unnecessary
*/
if (IOCGROUP(cmd) == 'i')
return (ifioctl(so, cmd, data, p));
if (IOCGROUP(cmd) == 'r')
return (rtioctl(cmd, data, p));
return ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
(struct mbuf *)cmd, (struct mbuf *)data, (struct mbuf *)0, p));
}
int
soo_fcntl(fp, cmd, data, p)
struct file *fp;
u_int cmd;
void *data;
struct proc *p;
{
if (cmd == F_SETFL)
return (0);
else
return (EOPNOTSUPP);
}
int
soo_poll(fp, events, p)
struct file *fp;
int events;
struct proc *p;
{
struct socket *so = (struct socket *)fp->f_data;
int revents = 0;
int s = splsoftnet();
if (events & (POLLIN | POLLRDNORM))
if (soreadable(so))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (sowritable(so))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & (POLLPRI | POLLRDBAND))
if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
revents |= events & (POLLPRI | POLLRDBAND);
if (revents == 0) {
if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
selrecord(p, &so->so_rcv.sb_sel);
so->so_rcv.sb_flags |= SB_SEL;
}
if (events & (POLLOUT | POLLWRNORM)) {
selrecord(p, &so->so_snd.sb_sel);
so->so_snd.sb_flags |= SB_SEL;
}
}
splx(s);
return (revents);
}
int
soo_stat(fp, ub, p)
struct file *fp;
struct stat *ub;
struct proc *p;
{
struct socket *so = (struct socket *)fp->f_data;
memset((caddr_t)ub, 0, sizeof(*ub));
ub->st_mode = S_IFSOCK;
return ((*so->so_proto->pr_usrreq)(so, PRU_SENSE,
(struct mbuf *)ub, (struct mbuf *)0, (struct mbuf *)0, p));
}
/* ARGSUSED */
int
soo_close(fp, p)
struct file *fp;
struct proc *p;
{
int error = 0;
if (fp->f_data)
error = soclose((struct socket *)fp->f_data);
fp->f_data = 0;
return (error);
}