freebsd-dev/sys/netinet/libalias/alias_dummy.c
Lutz Donnerhacke effc8e57fb libalias: Style cleanup
libalias is a convolut of various coding styles modified by a series
of different editors enforcing interesting convetions on spacing and
comments.

This patch is a baseline to start with a perfomance rework of
libalias.  Upcoming patches should be focus on the code, not on the
style.  That's why most annoying style errors should be fixed
beforehand.

Reviewed by:	hselasky
Discussed by:	emaste
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D30259
2021-05-15 08:57:55 +02:00

152 lines
4.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 Paolo Pisati <piso@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("$FreeBSD$");
/*
* Alias_dummy is just an empty skeleton used to demostrate how to write
* a module for libalias, that will run unalterated in userland or in
* kernel land.
*/
#ifdef _KERNEL
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#else
#include <errno.h>
#include <sys/types.h>
#include <stdio.h>
#endif
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#ifdef _KERNEL
#include <netinet/libalias/alias_local.h>
#include <netinet/libalias/alias_mod.h>
#else
#include "alias_local.h"
#include "alias_mod.h"
#endif
static void
AliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah);
static int
fingerprint(struct libalias *la, struct alias_data *ah)
{
/*
* Check here all the data that will be used later, if any field
* is empy/NULL, return a -1 value.
*/
if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL ||
ah->maxpktsize == 0)
return (-1);
/*
* Fingerprint the incoming packet, if it matches any conditions
* return an OK value.
*/
if (ntohs(*ah->dport) == 123 || ntohs(*ah->sport) == 456)
return (0); /* I know how to handle it. */
return (-1); /* I don't recognize this packet. */
}
/*
* Wrap in this general purpose function, the real function used to alias the
* packets.
*/
static int
protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah)
{
AliasHandleDummy(la, pip, ah);
return (0);
}
/*
* NOTA BENE: the next variable MUST NOT be renamed in any case if you want
* your module to work in userland, cause it's used to find and use all
* the protocol handlers present in every module.
* So WATCH OUT, your module needs this variables and it needs it with
* ITS EXACT NAME: handlers.
*/
struct proto_handler handlers [] = {
{
.pri = 666,
.dir = IN|OUT,
.proto = UDP|TCP,
.fingerprint = &fingerprint,
.protohandler = &protohandler
},
{ EOH }
};
static int
mod_handler(module_t mod, int type, void *data)
{
int error;
switch (type) {
case MOD_LOAD:
error = 0;
LibAliasAttachHandlers(handlers);
break;
case MOD_UNLOAD:
error = 0;
LibAliasDetachHandlers(handlers);
break;
default:
error = EINVAL;
}
return (error);
}
#ifdef _KERNEL
static
#endif
moduledata_t alias_mod = {
"alias_dummy", mod_handler, NULL
};
#ifdef _KERNEL
DECLARE_MODULE(alias_dummy, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
MODULE_VERSION(alias_dummy, 1);
MODULE_DEPEND(alias_dummy, libalias, 1, 1, 1);
#endif
static void
AliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah)
{
; /* Dummy. */
}