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/*
* Copyright (c) 1997-1998 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* This is the Simple Packet Filter interface.
* It filters the input from a netio object and passes it to annother.
*/
#include <oskit/dev/dev.h>
#include <oskit/dev/net.h>
#include <oskit/io/netio.h>
#include <oskit/c/string.h>
#include <oskit/c/stdlib.h>
#if 0
/*
* Example use:
*/
/*
* Preconditions:
*
* filtered_netio is an initialized netio object that will
* receive the filtered packets.
*
* Variables:
*
* fnetio_out is used to transmit packets
* fnetio_in is the netio that receives raw incomming packets
*
* device_push_netio *could* be used to bypass the outgoing PF
*/
/* incoming fanout */
fnetio_in = oskit_netio_fanout_create();
/* outgoing fanout */
fnetio_out = oskit_netio_fanout_create();
/*
* Open the ethernet device, with incomming_netio as
* the receiver; get the device send netio device_push_netio
* it initializes device_push_netio
*/
err = oskit_etherdev_open(etherdev, FLAGS, fnetio_in,
&device_push_netio);
osenv_assert(!err);
/* add device netio to outgoing fanout */
oskit_netio_fanout_add_listener(fnetio_out, device_push_netio);
/*
* fanout keeps a ref, so we can release ours, if the fanout is
* destroyed later down the road, it'll release the ref to the
* device
*/
oskit_netio_release(device_push_netio);
/*
* Create a SPF that receives packets from push_netio and
* forwards them to filtered_netio if they match the params
* it initializes push_netio
*/
oskit_netio_spf_create(..., filtered_netio, &push_netio);
/* make sure pf receives incoming packets */
oskit_netio_fanout_add_listener(fnetio_in, push_netio);
/*
* We want to get filtered packets that are being transmitted
* as well as received:
*/
oskit_netio_fanout_add_listener(fnetio_out, push_netio);
/*
* Okay, now filtered_netio is receiving all packets that
* match the filter, for both incomming and outgoing packets.
* device_push_netio is used to transmit packets
*/
/*
* End example
*/
#endif
struct spfdata {
oskit_netio_t *netio;
char *filter;
int len;
int offset;
};
/*
* This is the function that does the filtering.
*/
static oskit_error_t
filter_func(void *param, oskit_bufio_t *b, oskit_size_t pkt_size)
{
struct spfdata *data = (struct spfdata *)param;
char *pkt;
int err;
/* if packet isn't big enough... */
if (data->len + data->offset > pkt_size) {
return 0;
}
/* check to see if the bufio matches the filter */
err = oskit_bufio_map(b, (void **)&pkt, data->offset, data->len);
osenv_assert(!err);
if (!memcmp(data->filter, pkt, data->len)) {
/* matches, call the netio's push routine */
oskit_netio_push(data->netio, b, pkt_size);
}
/* if doesn't match, just return */
err = oskit_bufio_unmap(b, (void *)pkt, data->offset, data->len);
osenv_assert(!err);
return 0;
}
/*
* This is called when the netio object created is no longer used.
* We `cleanup' -- release the storage, since there are
* no more references to it anyway.
*/
static void
cleanup(void *param)
{
struct spfdata *s = param;
osenv_mem_free(s->filter, 0, s->len);
osenv_mem_free(param, 0, sizeof(struct spfdata));
}
/*
* This function creates a SPF netio.
*/
int
oskit_netio_spf_create(char *filter, int len, int offset,
oskit_netio_t *out_netio, oskit_netio_t **push_netio)
{
struct spfdata *data;
oskit_netio_t *pnetio;
data = osenv_mem_alloc(sizeof(*data), 0, 0);
if (!data)
return OSKIT_ENOMEM;
data->netio = out_netio;
data->filter = osenv_mem_alloc(len, 0, 0);
if (!data->filter)
return OSKIT_ENOMEM;
memcpy(data->filter, filter, data->len = len);
data->offset = offset;
pnetio = oskit_netio_create_cleanup(filter_func, data, cleanup);
if (!pnetio)
return OSKIT_E_UNEXPECTED; /* XXX */
*push_netio = pnetio;
return 0;
}
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