osd-contiki/core/net/rime/ipolite.c
adamdunkels 585620c102 Reverted the recent change from random_rand() to rand(). It turned out that
since libc rand() returns a signed int, there were frequently problems with
timer values wrapping. By reverting to random_rand(), we can provide a
random generator that returns an unsigned and the timer problems are solved.
2009-02-11 11:08:53 +00:00

177 lines
5.1 KiB
C

/**
* \addtogroup rimeipolite
* @{
*/
/*
* Copyright (c) 2007, Swedish Institute of Computer Science.
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
* $Id: ipolite.c,v 1.12 2009/02/11 11:08:56 adamdunkels Exp $
*/
/**
* \file
* Ipolite Anonymous best effort local area BroadCast (ipolite)
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "net/rime.h"
#include "net/rime/ipolite.h"
#include "lib/random.h"
#include <string.h>
#ifndef MAX
#define MAX(a, b) ((a) > (b)? (a) : (b))
#endif /* MAX */
#ifndef MIN
#define MIN(a, b) ((a) > (b)? (a) : (b))
#endif /* MIN */
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
static void
recv(struct broadcast_conn *broadcast, rimeaddr_t *from)
{
struct ipolite_conn *c = (struct ipolite_conn *)broadcast;
if(c->q != NULL &&
rimebuf_datalen() == queuebuf_datalen(c->q) &&
memcmp(rimebuf_dataptr(), queuebuf_dataptr(c->q),
MIN(c->hdrsize, rimebuf_datalen())) == 0) {
/* We received a copy of our own packet, so we do not send out
packet. */
queuebuf_free(c->q);
c->q = NULL;
ctimer_stop(&c->t);
if(c->cb->dropped) {
c->cb->dropped(c);
}
}
if(c->cb->recv) {
c->cb->recv(c, from);
}
}
/*---------------------------------------------------------------------------*/
static void
send(void *ptr)
{
struct ipolite_conn *c = ptr;
PRINTF("%d.%d: ipolite: send queuebuf %p\n",
rimeaddr_node_addr.u8[0],rimeaddr_node_addr.u8[1],
c->q);
if(c->q != NULL) {
queuebuf_to_rimebuf(c->q);
queuebuf_free(c->q);
c->q = NULL;
broadcast_send(&c->c);
if(c->cb->sent) {
c->cb->sent(c);
}
}
}
/*---------------------------------------------------------------------------*/
static const struct broadcast_callbacks broadcast = { recv };
/*---------------------------------------------------------------------------*/
void
ipolite_open(struct ipolite_conn *c, uint16_t channel,
const struct ipolite_callbacks *cb)
{
broadcast_open(&c->c, channel, &broadcast);
c->cb = cb;
}
/*---------------------------------------------------------------------------*/
void
ipolite_close(struct ipolite_conn *c)
{
broadcast_close(&c->c);
ctimer_stop(&c->t);
if(c->q != NULL) {
queuebuf_free(c->q);
c->q = NULL;
}
}
/*---------------------------------------------------------------------------*/
int
ipolite_send(struct ipolite_conn *c, clock_time_t interval, uint8_t hdrsize)
{
if(c->q != NULL) {
/* If we are already about to send a packet, we cancel the old one. */
PRINTF("%d.%d: ipolite_send: cancel old send\n",
rimeaddr_node_addr.u8[0],rimeaddr_node_addr.u8[1]);
queuebuf_free(c->q);
}
c->hdrsize = hdrsize;
if(interval == 0) {
PRINTF("%d.%d: ipolite_send: interval 0\n",
rimeaddr_node_addr.u8[0],rimeaddr_node_addr.u8[1]);
if (broadcast_send(&c->c)) {
if(c->cb->sent) {
c->cb->sent(c);
}
return 1;
}
} else {
c->q = queuebuf_new_from_rimebuf();
if(c->q != NULL) {
ctimer_set(&c->t,
interval / 2 + (random_rand() % (interval / 2)),
send, c);
return 1;
}
PRINTF("%d.%d: ipolite_send: could not allocate queue buffer\n",
rimeaddr_node_addr.u8[0],rimeaddr_node_addr.u8[1]);
}
return 0;
}
/*---------------------------------------------------------------------------*/
void
ipolite_cancel(struct ipolite_conn *c)
{
ctimer_stop(&c->t);
if(c->q != NULL) {
queuebuf_free(c->q);
c->q = NULL;
}
}
/*---------------------------------------------------------------------------*/
/** @} */