sys_socket.c

/*	$NetBSD: sys_socket.c,v 1.81 2023/04/22 13:53:02 riastradh Exp $	*/

/*-
 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * 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 1.81 2023/04/22 13:53:02 riastradh Exp $");

#include <sys/param.h>
#include <sys/systm.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 <sys/kauth.h>

#include <net/if.h>
#include <net/route.h>

static int soo_fpathconf(struct file *, int, register_t *);
static int soo_posix_fadvise(struct file *, off_t, off_t, int);

const struct fileops socketops = {
	.fo_name = "socket",
	.fo_read = soo_read,
	.fo_write = soo_write,
	.fo_ioctl = soo_ioctl,
	.fo_fcntl = fnullop_fcntl,
	.fo_poll = soo_poll,
	.fo_stat = soo_stat,
	.fo_close = soo_close,
	.fo_kqfilter = soo_kqfilter,
	.fo_restart = soo_restart,
	.fo_fpathconf = soo_fpathconf,
	.fo_posix_fadvise = soo_posix_fadvise,
};

int (*ifioctl)(struct socket *, u_long, void *, struct lwp *) = (void *)eopnotsupp;

/* ARGSUSED */
int
soo_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
	 int flags)
{
	struct socket *so = fp->f_socket;
	int error;

	error = (*so->so_receive)(so, NULL, uio, NULL, NULL, NULL);

	return error;
}

/* ARGSUSED */
int
soo_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
	  int flags)
{
	struct socket *so = fp->f_socket;
	int error;

	error = (*so->so_send)(so, NULL, uio, NULL, NULL, 0, curlwp);

	return error;
}

int
soo_ioctl(file_t *fp, u_long cmd, void *data)
{
	struct socket *so = fp->f_socket;
	int error = 0;

	switch (cmd) {

	case FIONBIO:
		solock(so);
		if (*(int *)data)
			so->so_state |= SS_NBIO;
		else 
			so->so_state &= ~SS_NBIO;
		sounlock(so);
		break;

	case FIOASYNC:
		solock(so);
		if (*(int *)data) {
			so->so_rcv.sb_flags |= SB_ASYNC;
			so->so_snd.sb_flags |= SB_ASYNC;
		} else {
			so->so_rcv.sb_flags &= ~SB_ASYNC;
			so->so_snd.sb_flags &= ~SB_ASYNC;
		}
		sounlock(so);
		break;

	case FIONREAD:
		*(int *)data = so->so_rcv.sb_cc;
		break;

	case FIONWRITE:
		*(int *)data = so->so_snd.sb_cc;
		break;

	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.
		 */
		solock(so);
		if ((so->so_snd.sb_hiwat < so->so_snd.sb_cc)
		    || (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
			*(int *)data = 0;
		else
			*(int *)data = sbspace(&so->so_snd);
		sounlock(so);
		break;

	case SIOCSPGRP:
	case FIOSETOWN:
	case TIOCSPGRP:
		error = fsetown(&so->so_pgid, cmd, data);
		break;

	case SIOCGPGRP:
	case FIOGETOWN:
	case TIOCGPGRP:
		error = fgetown(so->so_pgid, cmd, data);
		break;

	case SIOCATMARK:
		*(int *)data = (so->so_state&SS_RCVATMARK) != 0;
		break;

	case SIOCPEELOFF:
		solock(so);
		error = do_sys_peeloff(so, data);
		sounlock(so);
		break;

	default:
		/*
		 * Interface/routing/protocol specific ioctls:
		 * interface and routing ioctls should have a
		 * different entry since a socket's unnecessary
		 */
		if (IOCGROUP(cmd) == 'i')
			/*
			 * KERNEL_LOCK will be held later if if_ioctl() of the
			 * interface isn't MP-safe.
			 */
			error = ifioctl(so, cmd, data, curlwp);
		else {
			KERNEL_LOCK(1, NULL);
			error = (*so->so_proto->pr_usrreqs->pr_ioctl)(so,
			    cmd, data, NULL);
			KERNEL_UNLOCK_ONE(NULL);
		}
		break;
	}


	return error;
}

int
soo_poll(file_t *fp, int events)
{

	return sopoll(fp->f_socket, events);
}

int
soo_stat(file_t *fp, struct stat *ub)
{
	struct socket *so = fp->f_socket;
	int error;

	memset(ub, 0, sizeof(*ub));
	ub->st_mode = S_IFSOCK;

	solock(so);
	error = (*so->so_proto->pr_usrreqs->pr_stat)(so, ub);
	sounlock(so);

	return error;
}

/* ARGSUSED */
int
soo_close(file_t *fp)
{
	int error = 0;

	if (fp->f_socket)
		error = soclose(fp->f_socket);
	fp->f_socket = NULL;

	return error;
}

void
soo_restart(file_t *fp)
{

	sorestart(fp->f_socket);
}

static int
soo_fpathconf(struct file *fp, int name, register_t *retval)
{

	switch (name) {
	case _PC_PIPE_BUF:
		*retval = PIPE_BUF;
		return 0;
	default:
		return EINVAL;
	}
}

static int
soo_posix_fadvise(struct file *fp, off_t offset, off_t len, int advice)
{

	return ESPIPE;
}