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linkstats_status.c from EmStar at Krugle


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/*
 *
 * Copyright (c) 2003 The Regents of the University of California.  All 
 * rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 */
 

/*
 * linkstats_status.c: Functions that provide the status interface to
 * the users of the linkstats service  
 *
 * $Id: linkstats_status.c,v 1.10 2004/09/15 18:03:10 girod Exp $
 */

char linkstats_status_c_id[] = "$Id: linkstats_status.c,v 1.10 2004/09/15 18:03:10 girod Exp $";

#include "linkstats_i.h"

#define NULL_TIME(timeval) ((timeval).tv_sec == 0 && (timeval).tv_usec == 0)

/****************** Status Device Printing ************************/


static int marshal_status(neighbor_list_t *nl, buf_t *buf)
{
  neighbor_el_t *ne;
  int num = 0;

  /* copy all the entries onto the buf */
  for (ne = neighbor_list_top(nl); ne; ne = neighbor_list_next(ne)) {
    bufcpy(buf, &ne->info, sizeof(ne->info));
    num++;
  }

  return num;
}

char *print_ago(struct timeval *now, struct timeval *t)
{
  DECLARE_STATIC_BUF_RING(buf, 5, 20);

  if (NULL_TIME(*t))
    sprintf(buf, "--");
  else
    sprintf(buf, "%.2f", misc_tv_offset(now, t) / MILLION_F);

  return buf;
}


static int linkstats_status_printable(status_context_t *info, buf_t *buf)
{
  neighbor_list_t *nl = (neighbor_list_t *) sd_data(info);
  buf_t *bin_buf = buf_new();
  int num_neighbors = marshal_status(nl, bin_buf), i;
  neigh_t *n = (neigh_t *) bin_buf->buf;
  struct timeval now;

  gettimeofday(&now, NULL);

  bufprintf(buf, "Interface ID  Connectivity IN (%%)  Last Heard\n"
	         "------------  -------------------  ----------\n");
  
  for (i = 0; i < num_neighbors; n++, i++)
    bufprintf(buf, "%12s  %19.3f  %10s\n", print_if_id(n->if_id),
	      n->conn_in, print_ago(&now, &n->last_heard));
  

  buf_free(bin_buf);
  return STATUS_MSG_COMPLETE;
}


static int linkstats_status_binary(status_context_t *info, buf_t *buf)
{
  neighbor_list_t *nl = (neighbor_list_t *) sd_data(info);

  marshal_status(nl, buf);
  return STATUS_MSG_COMPLETE;
}


void linkstats_status_notify(neighbor_list_t *nl)
{
  elog(LOG_DEBUG(2), "notifying status interface");
  g_status_dev_notify(nl->status);
}


/************* Evaluation of Neighbor State ***********************/


/*
 * Evaluate one neighbor.  If the state has changed, return 1; else,
 * return 0
 */
int linkstats_evaluate_one(neighbor_list_t *nl, neighbor_el_t *ne)
{

  elog(LOG_DEBUG(2), "evaluating neighbor id %s",
       print_if_id(ne->info.if_id));

  elog(LOG_DEBUG(5), "Previous connectivity value: %3.2f -- New "
       "connectivity value: %3.2f", ne->status_conn*100.0, 
       ne->info.conn_in*100.0);
  
  /* if connectivity has changed, update value and notify */
  if(ne->status_conn != ne->info.conn_in) {
    ne->status_conn = ne->info.conn_in;
    return 1;
  }
  
  return 0;
}


/* Evaluate the state of ONE neighbor */
void linkstats_evaluate(neighbor_list_t *nl, neighbor_el_t *ne)
{
  if (linkstats_evaluate_one(nl, ne))
    linkstats_status_notify(nl);
}


/* Evaluate the state of ALL our neighbors */
void linkstats_evaluate_all(neighbor_list_t *nl)
{
  neighbor_el_t *ne;
  int notify = 0;

  /* If there are new neighbors, we nofify */
  if (nl->num_neighbors < neighbor_list_qlen(nl)) {
    nl->num_neighbors = neighbor_list_qlen(nl);
    notify = 1;
    goto notify;
  }
  
  /* if there is new data from some neighbor, we notify */
  for (ne = neighbor_list_top(nl); ne; ne = neighbor_list_next(ne))
    notify += linkstats_evaluate_one(nl, ne);

notify:
  if (notify)   
    linkstats_status_notify(nl);
}


/* Check neighbors connectivity values */
static int eval_periodic_timer(void *data, int interval, g_event_t *ev)
{
  neighbor_list_t *nl = (neighbor_list_t *) data;

  linkstats_evaluate_all(nl);
  return EVENT_RENEW;
}


void linkstats_status_init(neighbor_list_t *nl)
{
  /* Basic opts for our linkstats status device */
  status_dev_opts_t status_opts = {
    device: {
      devname: link_pass_name(nl->pass_context, "linkstats"),
      device_info: nl,
    },
    printable: linkstats_status_printable,
    binary:    linkstats_status_binary
  };

  /* Now create the status device */
  if (g_status_dev(&status_opts, &nl->status) < 0) {
    elog(LOG_CRIT, "can't create status device %s: %m", 
         status_opts.device.devname);
    exit(1);
  }

  /* Every second, evaluate all neighbors connectivity values to check
   * if they have chenged */
  g_timer_add(1000, eval_periodic_timer, nl, NULL, NULL);
}




See more files for this project here

EmStar

EmStar is a software system for developing and deploying wireless sensor networks involving Linux-based platforms. As the wireless sensor network community has attempted to deploy more complex designs---large-scale, long-lived systems that need self-organization and adaptivity---a number of difficult software design issues have arisen. Advances in software design have not kept pace with the capabilities of hardware. This is because designing for an adaptive, efficient, and useful sensor network has turned out to be surprisingly complex and difficult. EmStar is a Linux-based software framework, whose goal is to dramatically reduce this complexity, enabling work to be shared and reused, and simplifying and speeding the design of new sensor network applications.

Project homepage: http://cvs.cens.ucla.edu/emstar/
Programming language(s): C,Shell Script
License: other

  linkstats_i.h
  linkstats_main.c
  linkstats_passthru.c
  linkstats_status.c
  linkstats_util.c