585620c102
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.
147 lines
4.3 KiB
C
147 lines
4.3 KiB
C
/**
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* \addtogroup rimepolite
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* @{
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*/
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/*
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* Copyright (c) 2007, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This file is part of the Contiki operating system.
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*
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* $Id: polite.c,v 1.7 2009/02/11 11:08:56 adamdunkels Exp $
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*/
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/**
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* \file
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* Polite Anonymous best effort local area BroadCast (polite)
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* \author
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* Adam Dunkels <adam@sics.se>
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*/
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#include "net/rime.h"
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#include "net/rime/polite.h"
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#include "lib/random.h"
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#include <string.h>
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#ifndef MAX
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#define MAX(a,b) ((a)>(b)?(a):(b))
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#endif /* MAX */
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#ifndef MIN
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#define MIN(a, b) ((a) > (b)? (a) : (b))
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#endif /* MIN */
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/*---------------------------------------------------------------------------*/
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static void
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recv(struct abc_conn *abc)
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{
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struct polite_conn *c = (struct polite_conn *)abc;
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if(c->q != NULL &&
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rimebuf_datalen() == queuebuf_datalen(c->q) &&
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memcmp(rimebuf_dataptr(), queuebuf_dataptr(c->q),
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MIN(c->hdrsize, rimebuf_datalen())) == 0) {
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/* We received a copy of our own packet, so we do not send out
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packet. */
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queuebuf_free(c->q);
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c->q = NULL;
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ctimer_stop(&c->t);
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if(c->cb->dropped) {
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c->cb->dropped(c);
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}
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}
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if(c->cb->recv) {
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c->cb->recv(c);
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}
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}
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/*---------------------------------------------------------------------------*/
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static void
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send(void *ptr)
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{
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struct polite_conn *c = ptr;
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if(c->q != NULL) {
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queuebuf_to_rimebuf(c->q);
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queuebuf_free(c->q);
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c->q = NULL;
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abc_send(&c->c);
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if(c->cb->sent) {
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c->cb->sent(c);
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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static const struct abc_callbacks abc = { recv };
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/*---------------------------------------------------------------------------*/
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void
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polite_open(struct polite_conn *c, uint16_t channel,
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const struct polite_callbacks *cb)
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{
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abc_open(&c->c, channel, &abc);
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c->cb = cb;
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}
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/*---------------------------------------------------------------------------*/
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void
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polite_close(struct polite_conn *c)
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{
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abc_close(&c->c);
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ctimer_stop(&c->t);
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if(c->q != NULL) {
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queuebuf_free(c->q);
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c->q = NULL;
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}
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}
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/*---------------------------------------------------------------------------*/
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int
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polite_send(struct polite_conn *c, clock_time_t interval, uint8_t hdrsize)
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{
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if(c->q != NULL) {
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/* If we are already about to send a packet, we cancel the old one. */
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queuebuf_free(c->q);
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}
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c->hdrsize = hdrsize;
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c->q = queuebuf_new_from_rimebuf();
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if(c->q != NULL) {
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ctimer_set(&c->t, interval / 2 + (random_rand() % (interval / 2)), send, c);
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return 1;
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}
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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void
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polite_cancel(struct polite_conn *c)
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{
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ctimer_stop(&c->t);
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if(c->q != NULL) {
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queuebuf_free(c->q);
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c->q = NULL;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @} */
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