freebsd-skq/sys/kern/sys_socket.c
Alfred Perlstein 426da3bcfb SMP Lock struct file, filedesc and the global file list.
Seigo Tanimura (tanimura) posted the initial delta.

I've polished it quite a bit reducing the need for locking and
adapting it for KSE.

Locks:

1 mutex in each filedesc
   protects all the fields.
   protects "struct file" initialization, while a struct file
     is being changed from &badfileops -> &pipeops or something
     the filedesc should be locked.

1 mutex in each struct file
   protects the refcount fields.
   doesn't protect anything else.
   the flags used for garbage collection have been moved to
     f_gcflag which was the FILLER short, this doesn't need
     locking because the garbage collection is a single threaded
     container.
  could likely be made to use a pool mutex.

1 sx lock for the global filelist.

struct file *	fhold(struct file *fp);
        /* increments reference count on a file */

struct file *	fhold_locked(struct file *fp);
        /* like fhold but expects file to locked */

struct file *	ffind_hold(struct thread *, int fd);
        /* finds the struct file in thread, adds one reference and
                returns it unlocked */

struct file *	ffind_lock(struct thread *, int fd);
        /* ffind_hold, but returns file locked */

I still have to smp-safe the fget cruft, I'll get to that asap.
2002-01-13 11:58:06 +00:00

208 lines
5.6 KiB
C

/*
* 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. 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.
*
* @(#)sys_socket.c 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/filio.h> /* XXX */
#include <sys/sockio.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/filedesc.h>
#include <sys/ucred.h>
#include <net/if.h>
#include <net/route.h>
struct fileops socketops = {
soo_read, soo_write, soo_ioctl, soo_poll, sokqfilter,
soo_stat, soo_close
};
/* ARGSUSED */
int
soo_read(fp, uio, cred, flags, td)
struct file *fp;
struct uio *uio;
struct ucred *cred;
struct thread *td;
int flags;
{
struct socket *so = (struct socket *)fp->f_data;
return so->so_proto->pr_usrreqs->pru_soreceive(so, 0, uio, 0, 0, 0);
}
/* ARGSUSED */
int
soo_write(fp, uio, cred, flags, td)
struct file *fp;
struct uio *uio;
struct ucred *cred;
struct thread *td;
int flags;
{
struct socket *so = (struct socket *)fp->f_data;
return so->so_proto->pr_usrreqs->pru_sosend(so, 0, uio, 0, 0, 0,
uio->uio_td);
}
int
soo_ioctl(fp, cmd, data, td)
struct file *fp;
u_long cmd;
register caddr_t data;
struct thread *td;
{
register 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 FIOSETOWN:
return (fsetown(*(int *)data, &so->so_sigio));
case FIOGETOWN:
*(int *)data = fgetown(so->so_sigio);
return (0);
case SIOCSPGRP:
return (fsetown(-(*(int *)data), &so->so_sigio));
case SIOCGPGRP:
*(int *)data = -fgetown(so->so_sigio);
return (0);
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, td));
if (IOCGROUP(cmd) == 'r')
return (rtioctl(cmd, data));
return ((*so->so_proto->pr_usrreqs->pru_control)(so, cmd, data, 0, td));
}
int
soo_poll(fp, events, cred, td)
struct file *fp;
int events;
struct ucred *cred;
struct thread *td;
{
struct socket *so = (struct socket *)fp->f_data;
return so->so_proto->pr_usrreqs->pru_sopoll(so, events, cred, td);
}
int
soo_stat(fp, ub, td)
struct file *fp;
struct stat *ub;
struct thread *td;
{
struct socket *so = (struct socket *)fp->f_data;
bzero((caddr_t)ub, sizeof (*ub));
ub->st_mode = S_IFSOCK;
/*
* If SS_CANTRCVMORE is set, but there's still data left in the
* receive buffer, the socket is still readable.
*/
if ((so->so_state & SS_CANTRCVMORE) == 0 ||
so->so_rcv.sb_cc != 0)
ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
if ((so->so_state & SS_CANTSENDMORE) == 0)
ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
ub->st_size = so->so_rcv.sb_cc;
ub->st_uid = so->so_cred->cr_uid;
ub->st_gid = so->so_cred->cr_gid;
return ((*so->so_proto->pr_usrreqs->pru_sense)(so, ub));
}
/*
* API socket close on file pointer. We call soclose() to close the
* socket (including initiating closing protocols). soclose() will
* sorele() the file reference but the actual socket will not go away
* until the socket's ref count hits 0.
*/
/* ARGSUSED */
int
soo_close(fp, td)
struct file *fp;
struct thread *td;
{
int error = 0;
struct socket *so;
so = (struct socket *)fp->f_data;
fp->f_ops = &badfileops;
fp->f_data = 0;
if (so)
error = soclose(so);
return (error);
}