contiki/core/net/rime/rudolph0.c
2014-01-26 23:20:45 +01:00

243 lines
7.7 KiB
C

/**
* \addtogroup rudolph0
* @{
*/
/*
* 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.
*
*/
/**
* \file
* Rudolph0: a simple block data flooding protocol
* \author
* Adam Dunkels <adam@sics.se>
*/
#include <stddef.h> /* for offsetof */
#include "net/rime/rime.h"
#include "net/rime/rudolph0.h"
#define STEADY_TIME CLOCK_SECOND * 2
#define DEFAULT_SEND_INTERVAL CLOCK_SECOND / 2
enum {
TYPE_DATA,
TYPE_NACK,
};
enum {
STATE_RECEIVER,
STATE_SENDER,
};
#define VERSION_LT(a, b) ((signed char)((a) - (b)) < 0)
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
static void
read_new_datapacket(struct rudolph0_conn *c)
{
int len = 0;
if(c->cb->read_chunk) {
len = c->cb->read_chunk(c, c->current.h.chunk * RUDOLPH0_DATASIZE,
c->current.data, RUDOLPH0_DATASIZE);
}
c->current.datalen = len;
PRINTF("read_new_datapacket len %d\n", len);
}
/*---------------------------------------------------------------------------*/
static void
send_nack(struct rudolph0_conn *c)
{
struct rudolph0_hdr *hdr;
packetbuf_clear();
packetbuf_hdralloc(sizeof(struct rudolph0_hdr));
hdr = packetbuf_hdrptr();
hdr->type = TYPE_NACK;
hdr->version = c->current.h.version;
hdr->chunk = c->current.h.chunk;
PRINTF("Sending nack for %d:%d\n", hdr->version, hdr->chunk);
polite_send(&c->nackc, c->send_interval / 2, sizeof(struct rudolph0_hdr));
}
/*---------------------------------------------------------------------------*/
static void
sent(struct stbroadcast_conn *stbroadcast)
{
struct rudolph0_conn *c = (struct rudolph0_conn *)stbroadcast;
if(c->current.datalen == RUDOLPH0_DATASIZE) {
c->current.h.chunk++;
PRINTF("Sending data chunk %d next time\n", c->current.h.chunk);
read_new_datapacket(c);
} else {
stbroadcast_set_timer(&c->c, STEADY_TIME);
PRINTF("Steady: Sending the same data chunk next time datalen %d, %d\n",
c->current.datalen, RUDOLPH0_DATASIZE);
}
}
/*---------------------------------------------------------------------------*/
static void
recv(struct stbroadcast_conn *stbroadcast)
{
struct rudolph0_conn *c = (struct rudolph0_conn *)stbroadcast;
struct rudolph0_datapacket *p = packetbuf_dataptr();
if(p->h.type == TYPE_DATA) {
if(c->current.h.version != p->h.version) {
PRINTF("rudolph0 new version %d\n", p->h.version);
c->current.h.version = p->h.version;
c->current.h.chunk = 0;
c->cb->write_chunk(c, 0, RUDOLPH0_FLAG_NEWFILE, p->data, 0);
if(p->h.chunk != 0) {
send_nack(c);
} else {
c->cb->write_chunk(c, 0, RUDOLPH0_FLAG_NONE, p->data, p->datalen);
c->current.h.chunk++;
}
} else if(p->h.version == c->current.h.version) {
if(p->h.chunk == c->current.h.chunk) {
PRINTF("received chunk %d\n", p->h.chunk);
if(p->datalen < RUDOLPH0_DATASIZE) {
c->cb->write_chunk(c, c->current.h.chunk * RUDOLPH0_DATASIZE,
RUDOLPH0_FLAG_LASTCHUNK, p->data, p->datalen);
} else {
c->cb->write_chunk(c, c->current.h.chunk * RUDOLPH0_DATASIZE,
RUDOLPH0_FLAG_NONE, p->data, p->datalen);
}
c->current.h.chunk++;
} else if(p->h.chunk > c->current.h.chunk) {
PRINTF("received chunk %d > %d, sending NACK\n", p->h.chunk, c->current.h.chunk);
send_nack(c);
}
} else { /* p->h.version < c->current.h.version */
/* Ignore packets with old version */
}
}
}
/*---------------------------------------------------------------------------*/
static void
recv_nack(struct polite_conn *polite)
{
struct rudolph0_conn *c = (struct rudolph0_conn *)
((char *)polite - offsetof(struct rudolph0_conn,
nackc));
struct rudolph0_datapacket *p = packetbuf_dataptr();
if(p->h.type == TYPE_NACK && c->state == STATE_SENDER) {
if(p->h.version == c->current.h.version) {
PRINTF("Reseting chunk to %d\n", p->h.chunk);
c->current.h.chunk = p->h.chunk;
} else {
PRINTF("Wrong version, reseting chunk to 0\n");
c->current.h.chunk = 0;
}
read_new_datapacket(c);
stbroadcast_set_timer(&c->c, c->send_interval);
}
}
/*---------------------------------------------------------------------------*/
static const struct polite_callbacks polite = { recv_nack, 0, 0 };
static const struct stbroadcast_callbacks stbroadcast = { recv, sent };
/*---------------------------------------------------------------------------*/
void
rudolph0_open(struct rudolph0_conn *c, uint16_t channel,
const struct rudolph0_callbacks *cb)
{
stbroadcast_open(&c->c, channel, &stbroadcast);
polite_open(&c->nackc, channel + 1, &polite);
c->cb = cb;
c->current.h.version = 0;
c->state = STATE_RECEIVER;
c->send_interval = DEFAULT_SEND_INTERVAL;
}
/*---------------------------------------------------------------------------*/
void
rudolph0_close(struct rudolph0_conn *c)
{
stbroadcast_close(&c->c);
polite_close(&c->nackc);
}
/*---------------------------------------------------------------------------*/
void
rudolph0_send(struct rudolph0_conn *c, clock_time_t send_interval)
{
c->state = STATE_SENDER;
c->current.h.version++;
c->current.h.version++;
c->current.h.chunk = 0;
c->current.h.type = TYPE_DATA;
read_new_datapacket(c);
packetbuf_reference(&c->current, sizeof(struct rudolph0_datapacket));
c->send_interval = send_interval;
stbroadcast_send_stubborn(&c->c, c->send_interval);
}
/*---------------------------------------------------------------------------*/
void
rudolph0_force_restart(struct rudolph0_conn *c)
{
c->current.h.chunk = 0;
send_nack(c);
}
/*---------------------------------------------------------------------------*/
void
rudolph0_stop(struct rudolph0_conn *c)
{
stbroadcast_cancel(&c->c);
}
/*---------------------------------------------------------------------------*/
int
rudolph0_version(struct rudolph0_conn *c)
{
return c->current.h.version;
}
/*---------------------------------------------------------------------------*/
void
rudolph0_set_version(struct rudolph0_conn *c, int version)
{
c->current.h.version = version;
}
/*---------------------------------------------------------------------------*/
/** @} */