172 lines
4.5 KiB
C
172 lines
4.5 KiB
C
/* $FreeBSD$ */
|
|
|
|
/*
|
|
* Copyright (c) 1996 Matthew R. Green
|
|
* 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. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/param.h>
|
|
#include <sys/errno.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/queue.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/pfil.h>
|
|
|
|
static void pfil_init(struct pfil_head *);
|
|
static int pfil_list_add(pfil_list_t *,
|
|
int (*)(void *, int, struct ifnet *, int, struct mbuf **), int);
|
|
static int pfil_list_remove(pfil_list_t *,
|
|
int (*)(void *, int, struct ifnet *, int, struct mbuf **));
|
|
|
|
static void
|
|
pfil_init(ph)
|
|
struct pfil_head *ph;
|
|
{
|
|
|
|
TAILQ_INIT(&ph->ph_in);
|
|
TAILQ_INIT(&ph->ph_out);
|
|
ph->ph_init = 1;
|
|
}
|
|
|
|
/*
|
|
* pfil_add_hook() adds a function to the packet filter hook. the
|
|
* flags are:
|
|
* PFIL_IN call me on incoming packets
|
|
* PFIL_OUT call me on outgoing packets
|
|
* PFIL_ALL call me on all of the above
|
|
* PFIL_WAITOK OK to call malloc with M_WAITOK.
|
|
*/
|
|
int
|
|
pfil_add_hook(func, flags, ph)
|
|
int (*func)(void *, int, struct ifnet *, int, struct mbuf **);
|
|
int flags;
|
|
struct pfil_head *ph;
|
|
{
|
|
int err = 0;
|
|
|
|
if (ph->ph_init == 0)
|
|
pfil_init(ph);
|
|
|
|
if (flags & PFIL_IN)
|
|
err = pfil_list_add(&ph->ph_in, func, flags & ~PFIL_OUT);
|
|
if (err)
|
|
return err;
|
|
if (flags & PFIL_OUT)
|
|
err = pfil_list_add(&ph->ph_out, func, flags & ~PFIL_IN);
|
|
if (err) {
|
|
if (flags & PFIL_IN)
|
|
pfil_list_remove(&ph->ph_in, func);
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
pfil_list_add(list, func, flags)
|
|
pfil_list_t *list;
|
|
int (*func)(void *, int, struct ifnet *, int, struct mbuf **);
|
|
int flags;
|
|
{
|
|
struct packet_filter_hook *pfh;
|
|
|
|
pfh = (struct packet_filter_hook *)malloc(sizeof(*pfh), M_IFADDR,
|
|
flags & PFIL_WAITOK ? M_WAITOK : M_NOWAIT);
|
|
if (pfh == NULL)
|
|
return ENOMEM;
|
|
pfh->pfil_func = func;
|
|
/*
|
|
* insert the input list in reverse order of the output list
|
|
* so that the same path is followed in or out of the kernel.
|
|
*/
|
|
|
|
if (flags & PFIL_IN)
|
|
TAILQ_INSERT_HEAD(list, pfh, pfil_link);
|
|
else
|
|
TAILQ_INSERT_TAIL(list, pfh, pfil_link);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* pfil_remove_hook removes a specific function from the packet filter
|
|
* hook list.
|
|
*/
|
|
int
|
|
pfil_remove_hook(func, flags, ph)
|
|
int (*func)(void *, int, struct ifnet *, int, struct mbuf **);
|
|
int flags;
|
|
struct pfil_head *ph;
|
|
{
|
|
int err = 0;
|
|
|
|
if (ph->ph_init == 0)
|
|
pfil_init(ph);
|
|
|
|
if (flags & PFIL_IN)
|
|
err = pfil_list_remove(&ph->ph_in, func);
|
|
if ((err == 0) && (flags & PFIL_OUT))
|
|
err = pfil_list_remove(&ph->ph_out, func);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* pfil_list_remove is an internal function that takes a function off the
|
|
* specified list.
|
|
*/
|
|
static int
|
|
pfil_list_remove(list, func)
|
|
pfil_list_t *list;
|
|
int (*func)(void *, int, struct ifnet *, int, struct mbuf **);
|
|
{
|
|
struct packet_filter_hook *pfh;
|
|
|
|
TAILQ_FOREACH(pfh, list, pfil_link)
|
|
if (pfh->pfil_func == func) {
|
|
TAILQ_REMOVE(list, pfh, pfil_link);
|
|
free(pfh, M_IFADDR);
|
|
return 0;
|
|
}
|
|
return ENOENT;
|
|
}
|
|
|
|
struct packet_filter_hook *
|
|
pfil_hook_get(flag, ph)
|
|
int flag;
|
|
struct pfil_head *ph;
|
|
{
|
|
if (ph->ph_init != 0)
|
|
switch (flag) {
|
|
case PFIL_IN:
|
|
return (TAILQ_FIRST(&ph->ph_in));
|
|
case PFIL_OUT:
|
|
return (TAILQ_FIRST(&ph->ph_out));
|
|
}
|
|
return NULL;
|
|
}
|