dsr-io.c

/* Copyright (C) Uppsala University
 *
 * This file is distributed under the terms of the GNU general Public
 * License (GPL), see the file LICENSE
 *
 * Author: Erik Nordström, <erikn@it.uu.se>
 */
#ifdef NS2
#include "ns-agent.h"
#else
#include "dsr-dev.h"
#endif

#include "dsr.h"
#include "dsr-pkt.h"
#include "dsr-rreq.h"
#include "dsr-rrep.h"
#include "dsr-srt.h"
#include "dsr-ack.h"
#include "dsr-rtc.h"
#include "dsr-ack.h"
#include "maint-buf.h"
#include "neigh.h"
#include "dsr-opt.h"
#include "link-cache.h"
#include "debug.h"
#include "send-buf.h"

int NSCLASS dsr_recv(struct dsr_pkt *dp)
{
	int i = 0, action;
	int mask = DSR_PKT_NONE;
	struct in_addr myaddr = my_addr();
	
	/* Ignore packets that are originated by this node to avoid
	 * poluting the link cache with old information that we keep
	 * on genereating. */
	if (dp->flags & PKT_PROMISC_RECV &&
	    memcmp(&myaddr, &dp->src, sizeof(struct in_addr)) == 0) {
		dsr_pkt_free(dp);
		return 0;
	}
	
	/* Process DSR Options */
	action = dsr_opt_recv(dp);

	/* Add mac address of previous hop to the neighbor table */

	if (dp->flags & PKT_PROMISC_RECV) {
		dsr_pkt_free(dp);
		return 0;
	}
	for (i = 0; i < DSR_PKT_ACTION_LAST; i++) {
	
		switch (action & mask) {
		case DSR_PKT_NONE:
			break;
		case DSR_PKT_DROP:
		case DSR_PKT_ERROR:
			LOG_DBG("DSR_PKT_DROP or DSR_PKT_ERROR\n");
			dsr_pkt_free(dp);
			return 0;
		case DSR_PKT_SEND_ACK:
			/* Moved to dsr-ack.c */
			break;
		case DSR_PKT_SRT_REMOVE:
			//LOG_DBG("Remove source route\n");
			// Hmm, we remove the DSR options when we deliver a
			//packet
			//dsr_opt_remove(dp);
			break;
		case DSR_PKT_FORWARD:

#ifdef NS2
			if (dp->nh.iph->ttl() < 1)
#else
			if (dp->nh.iph->ttl < 1)
#endif
			{
				LOG_DBG("ttl=0, dropping!\n");
				dsr_pkt_free(dp);
				return 0;
			} else {
				LOG_DBG("Forwarding %s %s nh %s\n",
				      print_ip(dp->src),
				      print_ip(dp->dst), print_ip(dp->nxt_hop));
				XMIT(dp);
				return 0;
			}
			break;
		case DSR_PKT_FORWARD_RREQ:
			XMIT(dp);
			return 0;
		case DSR_PKT_SEND_RREP:
			/* In dsr-rrep.c */
			break;
		case DSR_PKT_SEND_ICMP:
			LOG_DBG("Send ICMP\n");
			break;
		case DSR_PKT_SEND_BUFFERED:
			if (dp->rrep_opt) {
				struct in_addr rrep_srt_dst;
				int i;
				
				for (i = 0; i < dp->num_rrep_opts; i++) {
					rrep_srt_dst.s_addr = dp->rrep_opt[i]->addrs[DSR_RREP_ADDRS_LEN(dp->rrep_opt[i]) / sizeof(struct in_addr)];
					
					send_buf_set_verdict(SEND_BUF_SEND, rrep_srt_dst);
				}
			}
				break;
		case DSR_PKT_DELIVER:
			LOG_DBG("Deliver to DSR device\n");
			DELIVER(dp);
			return 0;
		case 0:
			break;
		default:
			LOG_DBG("Unknown pkt action\n");
		}
		mask = (mask << 1);
	}

	dsr_pkt_free(dp);

	return 0;
}

void NSCLASS dsr_start_xmit(struct dsr_pkt *dp)
{
	int res;

	if (!dp) {
		LOG_DBG("Could not allocate DSR packet\n");
		return;
	}

	dp->srt = dsr_rtc_find(dp->src, dp->dst);

	if (dp->srt) {

		if (dsr_srt_add(dp) < 0) {
			LOG_DBG("Could not add source route\n");
			goto out;
		}
		/* Send packet */

		XMIT(dp);

		return;

	} else {
#ifdef NS2
		res = send_buf_enqueue_packet(dp, &DSRUU::ns_xmit);
#else
		res = send_buf_enqueue_packet(dp, &dsr_dev_xmit);
#endif
		if (res < 0) {
			LOG_DBG("Queueing failed!\n");
			goto out;
		}
		res = dsr_rreq_route_discovery(dp->dst);

		if (res < 0)
			LOG_DBG("RREQ Transmission failed...");

		return;
	}
      out:
	dsr_pkt_free(dp);
}