Code Search for Developers
 
 
  

idr_upper.c from EmStar at Krugle


Show idr_upper.c syntax highlighted

/*
 *
 * 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.
 *
 */
 

/*
 * idr_upper.c: The "upper" half of idr, i.e. the interface that
 * we provide to users of the idr service.
 *
 * $Id: idr_upper.c,v 1.6 2003/07/11 22:29:52 cerpa Exp $
 */

char idr_upper_c_cvsid[] = "$Id: idr_upper.c,v 1.6 2003/07/11 22:29:52 cerpa Exp $";

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

#include "link/link.h"
#include "idr_i.h"


/********************************************************************/

/* 
 * Called when a local client tries to write a packet to our idr
 * device file.  Check the packet is valid before admitting it to the
 * queue.
 */
static int idr_enqueue(pd_context_t *pd, const void *packet, int packetlen)
{


    idr_state_t *f = (idr_state_t *) pd_data(pd);

    if (packetlen < sizeof(link_pkt_t)) {
	elog(LOG_ERR, "short packet (%d bytes) written to %s", packetlen, idr_dev_name(f));
	return -EINVAL;
    }


    return 0;
}


/*
static void pktbuf_add(buf_t *buf, idr_state_t *s)
{
    if (s->pktbuf[s->index]!=NULL) {
	buf_free(s->pktbuf[s->index]);
    }

    s->pktbuf[s->index]=buf;
    s->index++;
    if (s->index>=PKT_QUEUE_SIZE) {
	s->index=0;
    }
}
*/		
	

/*
 * Callback when the queue of packets written to our local device file
 * is serviced
 */
static int idr_send(pd_context_t *pd, const void *packet,
		      int packetlen, int loop_needed)
{

    idr_state_t *f = (idr_state_t *) pd_data(pd);


    // link_pkt_in is the packet being given to us by the user to send.
    link_pkt_t *link_pkt_in = (link_pkt_t *) packet;
    int data_len = packetlen - sizeof(link_pkt_t);


    // pkt_out is the packet we're getting ready to transmit 
    buf_t *pkt_out = buf_new();

    // Create our *outgoing* link header
    link_pkt_t link_hdr = {
	dst: {
	    id: LINK_BROADCAST, // we always want to broadcast our message
	},
		type: PKT_TYPE_IDR,
    };
    
    // Create the idr-specific header 
    idr_pkt_t idr_hdr = {
		sender: my_node_id,
		sub_type: IDR_DATA, 
    };
	
    idr_data_pkt_t idr_data_hdr = {
		inner_type: link_pkt_in->type,
		toAddr: 0,
		count: 0,
    };

    // Construct the packet: outer link header, inner idr header and idr
    // data sub packet, user payload
    bufcpy(pkt_out, &link_hdr, sizeof(link_hdr));
    bufcpy(pkt_out, &idr_hdr, sizeof(idr_hdr));
    bufcpy(pkt_out, &idr_data_hdr, sizeof(idr_data_hdr));
    bufcpy(pkt_out, link_pkt_in->data, data_len);

    // Send to all interfaces 
    idr_send_to_all(f,
		    (link_pkt_t *) pkt_out->buf,
		    pkt_out->len - sizeof(link_pkt_t));
    // add buffer to the buffer queue, so the we can retx it later
  //  pktbuf_add(pkt_out, f);

	// remove any old packets currently in the component state buffer queue
	
	if (f->pktbuf!=NULL) {
		buf_free(f->pktbuf);
	}	

	// add the current packet to the buffer queue
	f->pktbuf=pkt_out;	

    return 0;
}

/*
 * Register the idr device that other processes open to send idr
 * packets 
 */
void idr_register_packetdev(idr_state_t *f)
{
    /* set options for the packetdev */
    packet_dev_opts_t pd_opts = {
	send: idr_send,
	enqueue: idr_enqueue,
	filter: link_standard_filter,
	device: {
	    device_info: (void *) f,
		}
    };

    // and options to tell it what we're trying to register 
    memset(&(f->pd_link_opts), 0, sizeof(link_opts_t));
    f->pd_link_opts.dev_type = LINK_DEV_IDR;

    /* try to register the packetdev as a link interface */
    if (link_register(&pd_opts, &f->pd_context, &f->pd_link_opts) < 0) {
	elog(LOG_CRIT, "can't create packetdev %s: %m", pd_opts.device.devname);
	exit(1);
    }

    elog(LOG_INFO, "created upper interface, %s", pd_opts.device.devname);
}






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

  idr_binomial.c
  idr_binomial.h
  idr_conf.c
  idr_conf.h
  idr_i.h
  idr_lower.c
  idr_main.c
  idr_upper.c
  idr_util.c