mod_dup.c

/*
 * mod_dup.c
 *
 * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
 *
 * $Id$
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "pkt.h"
#include "mod.h"

#define DUP_FIRST	1
#define DUP_LAST	2
#define DUP_RANDOM	3

struct dup_data {
	rand_t	*rnd;
	int	 which;
	int	 percent;
};

void *
dup_close(void *d)
{
	struct dup_data *data = (struct dup_data *)d;
	
	if (data != NULL) {
		rand_close(data->rnd);
		free(data);
	}
	return (NULL);
}

void *
dup_open(int argc, char *argv[])
{
	struct dup_data *data;
	
	if (argc != 3)
		return (NULL);
	
	if ((data = malloc(sizeof(*data))) == NULL)
		return (NULL);

	data->rnd = rand_open();

	if (strcasecmp(argv[1], "first") == 0)
		data->which = DUP_FIRST;
	else if (strcasecmp(argv[1], "last") == 0)
		data->which = DUP_LAST;
	else if (strcasecmp(argv[1], "random") == 0)
		data->which = DUP_RANDOM;
	else
		return (dup_close(data));

	if ((data->percent = atoi(argv[2])) <= 0 || data->percent > 100)
		return (dup_close(data));

	return (data);
}

int
dup_apply(void *d, struct pktq *pktq)
{
	struct dup_data *data = (struct dup_data *)d;
	struct pkt *pkt, *new;
	
	if (data->percent < 100 &&
	    (rand_uint16(data->rnd) % 100) > data->percent)
		return (0);
	
	if ((new = pkt_new()) == NULL)
		return (-1);
	
	if (data->which == DUP_FIRST)
		pkt = TAILQ_FIRST(pktq);
	else if (data->which == DUP_LAST)
		pkt = TAILQ_LAST(pktq, pktq);
	else
		pkt = pktq_random(data->rnd, pktq);
	
	if (!pkt)
	    return -1;

	new = pkt_dup(pkt);
	if (!new)
	    return -1;

	TAILQ_INSERT_AFTER(pktq, pkt, new, pkt_next);
	
	return (0);
}

struct mod mod_dup = {
	"dup",					/* name */
	"dup first|last|random <prob-%>",	/* usage */
	dup_open,				/* open */
	dup_apply,				/* apply */
	dup_close				/* close */
};