freebsd-skq/sys/netinet/accf_data.c
markj b20c56f366 Define a module version for accept filter modules.
Otherwise accept filters compiled into the kernel do not preempt
preloaded accept filter modules.  Then, the preloaded file registers its
accept filter module before the kernel, and the kernel's attempt fails
since duplicate accept filter list entries are not permitted.  This
causes the preloaded file's module to be released, since
module_register_init() does a lookup by name, so the preloaded file is
unloaded, and the accept filter's callback points to random memory since
preload_delete_name() unmaps the file on x86 as of r336505.

Add a new ACCEPT_FILTER_DEFINE macro which wraps the accept filter and
module definitions, and ensures that a module version is defined.

PR:		245870
Reported by:	Thomas von Dein <freebsd@daemon.de>
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2020-05-19 18:35:08 +00:00

56 lines
1.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000 Alfred Perlstein <alfred@FreeBSD.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define ACCEPT_FILTER_MOD
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/signalvar.h>
#include <sys/socketvar.h>
/* accept filter that holds a socket until data arrives */
static int sohasdata(struct socket *so, void *arg, int waitflag);
ACCEPT_FILTER_DEFINE(accf_data, "dataready", sohasdata, NULL, NULL, 1);
static int
sohasdata(struct socket *so, void *arg, int waitflag)
{
if (!soreadable(so))
return (SU_OK);
return (SU_ISCONNECTED);
}