dsr-dev.c

DSR-UU is a DSR implementation that runs in Linux and in the ns-2 network simulator. DSR-UU imple

/* 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, <[e-mail]>
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/if_ether.h>
#include <net/ip.h>
#include <linux/random.h>
#include <linux/wireless.h>

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

/* Our dsr device */
static struct net_device *dsr_dev;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
/* dsr_node must be static on some older kernels, otherwise it segfaults on
 * module load */
static struct dsr_node *dsr_node;
#else
struct dsr_node *dsr_node;
#endif
static int rp_filter = 0;
static int forwarding = 0;


#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,14)
static int dsr_dev_llrecv(struct sk_buff *skb, struct net_device *indev,
			  struct packet_type *pt);
#else

static int dsr_dev_llrecv(struct sk_buff *skb, struct net_device *indev,
			  struct packet_type *pt, struct net_device *orig_dev);
#endif

static struct packet_type dsr_packet_type = {
	.type = __constant_htons(ETH_P_IP),
	.func = dsr_dev_llrecv,
};

struct sk_buff *dsr_skb_create(struct dsr_pkt *dp, struct net_device *dev)
{
	struct sk_buff *skb;
	char *buf;
	int ip_len;
	int tot_len;
	int dsr_opts_len = dsr_pkt_opts_len(dp);

	ip_len = dp->nh.iph->ihl << 2;

	tot_len = ip_len + dsr_opts_len + dp->payload_len;

	DEBUG("ip_len=%d dsr_opts_len=%d payload_len=%d tot_len=%d\n",
	      ip_len, dsr_opts_len, dp->payload_len, tot_len);
#ifdef KERNEL26
	skb = alloc_skb(tot_len + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
#else
	skb = alloc_skb(dev->hard_header_len + 15 + tot_len, GFP_ATOMIC);
#endif
	if (!skb) {
		DEBUG("alloc_skb failed\n");
		return NULL;
	}

	/* We align to 16 bytes, for ethernet: 2 bytes + 14 bytes header */
#ifdef KERNEL26
	skb_reserve(skb, LL_RESERVED_SPACE(dev));
#else
	skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
#endif
	skb->mac.raw = skb->data - 14;
	skb->nh.raw = skb->data;
	skb->dev = dev;
	skb->protocol = htons(ETH_P_IP);

	/* Copy in all the headers in the right order */
	buf = skb_put(skb, tot_len);

	memcpy(buf, dp->nh.raw, ip_len);

	/* For some reason the checksum has to be recalculated here, at least
	 * when there is a record route IP option */
	ip_send_check((struct iphdr *)buf);

	buf += ip_len;

	/* Add DSR header if it exists */
	if (dsr_opts_len) {
		memcpy(buf, dp->dh.raw, dsr_opts_len);
		buf += dsr_opts_len;
	}

	/* Add payload */
	if (dp->payload_len && dp->payload)
		memcpy(buf, dp->payload, dp->payload_len);

	return skb;
}

int dsr_hw_header_create(struct dsr_pkt *dp, struct sk_buff *skb)
{

	struct sockaddr broadcast =
	    { AF_UNSPEC, {0xff, 0xff, 0xff, 0xff, 0xff, 0xff} };
	struct neighbor_info neigh_info;

	if (dp->dst.s_addr == DSR_BROADCAST)
		memcpy(neigh_info.hw_addr.sa_data, broadcast.sa_data, ETH_ALEN);
	else {
		/* Get hardware destination address */
		if (neigh_tbl_query(dp->nxt_hop, &neigh_info) < 0) {
			DEBUG
			    ("Could not get hardware address for next hop %s\n",
			     print_ip(dp->nxt_hop));
			return -1;
		}
	}

	if (skb->dev->hard_header) {
		skb->dev->hard_header(skb, skb->dev, ETH_P_IP,
				      neigh_info.hw_addr.sa_data, 0, skb->len);
	} else {
		DEBUG("Missing hard_header\n");
		return -1;
	}
	return 0;
}

static int dsr_dev_inetaddr_event(struct notifier_block *this,
				  unsigned long event, void *ptr)
{
	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
	struct in_device *indev;

	if (!ifa)
		return NOTIFY_DONE;

	indev = ifa->ifa_dev;

	if (!indev)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UP:
		DEBUG("inetdev UP\n");

		if (indev->dev == dsr_dev) {
			struct dsr_node *dnode;
			struct in_addr addr, bc;

			dnode = (struct dsr_node *)indev->dev->priv;

			dsr_node_lock(dnode);
			dnode->ifaddr.s_addr = ifa->ifa_address;
			dnode->bcaddr.s_addr = ifa->ifa_broadcast;

			dnode->slave_indev = in_dev_get(dnode->slave_dev);

                        /* Disable rp_filter and enable forwarding */
                        if (dnode->slave_indev) {
                                rp_filter = dnode->slave_indev->cnf.rp_filter;
                                forwarding = dnode->slave_indev->cnf.forwarding;                                dnode->slave_indev->cnf.rp_filter = 0;
                                dnode->slave_indev->cnf.forwarding = 1;
                        }			
			dsr_node_unlock(dnode);
			
			addr.s_addr = ifa->ifa_address;
			bc.s_addr = ifa->ifa_broadcast;
			
			DEBUG("New ip=%s broadcast=%s\n",
			      print_ip(addr), print_ip(bc));
		}
		break;
	default:
		break;
	};
	return NOTIFY_DONE;
}

static int dsr_dev_netdev_event(struct notifier_block *this,
				unsigned long event, void *ptr)
{
	struct net_device *dev = (struct net_device *)ptr;
	struct dsr_node *dnode = (struct dsr_node *)dsr_dev->priv;
	int slave_change = 0;

	if (!dev)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_REGISTER:
		DEBUG("Netdev register %s\n", dev->name);
		if (dnode->slave_dev == NULL && 
		    strcmp(dev->name, dnode->slave_ifname) == 0) {
			
			DEBUG("Slave dev %s up\n", dev->name);
			
			dsr_node_lock(dnode);
			dnode->slave_dev = dev;
			dev_hold(dev);
			dsr_node_unlock(dnode);

			/* Reduce the MTU to allow DSR options of 100
			 * bytes. If larger, drop or implement
			 * fragmentation... ;-) Alternatively find a
			 * way to dynamically reduce the data size of
			 * packets depending on the size of the DSR
			 * header. */
			dsr_dev->mtu = dev->mtu - DSR_OPTS_MAX_SIZE;
			
			DEBUG("Registering packet type\n");
			dsr_packet_type.func = dsr_dev_llrecv;
			dsr_packet_type.dev = dev;
			dev_add_pack(&dsr_packet_type);
			
			slave_change = 1;
		}

		if (slave_change)
			DEBUG("New DSR slave interface %s\n", dev->name);
		break;
	case NETDEV_CHANGE:
		DEBUG("Netdev change\n");
		break;
	case NETDEV_UP:
		DEBUG("Netdev up %s\n", dev->name);
		if (ConfVal(PromiscOperation) &&
		    dev == dsr_dev && dnode->slave_dev)
			dev_set_promiscuity(dnode->slave_dev, +1);
		break;
	case NETDEV_UNREGISTER:
		DEBUG("Netdev unregister %s\n", dev->name);
		
		dsr_node_lock(dnode);
		if (dev == dnode->slave_dev) {
			dev_remove_pack(&dsr_packet_type);
			dsr_packet_type.func = NULL;
			slave_change = 1;
			dev_put(dev);
			dnode->slave_dev = NULL;
		}
		dsr_node_unlock(dnode);

		if (slave_change)
			DEBUG("DSR slave interface %s unregisterd\n",
			      dev->name);
		break;
	case NETDEV_DOWN:
		DEBUG("Netdev down %s\n", dev->name);
		if (dev == dsr_dev) {
			if (dnode->slave_dev && ConfVal(PromiscOperation))
				dev_set_promiscuity(dnode->slave_dev, -1);

			dsr_node_lock(dnode);
                        if (dnode->slave_indev) {
                                dnode->slave_indev->cnf.rp_filter = rp_filter;
                                dnode->slave_indev->cnf.forwarding = forwarding;                                in_dev_put(dnode->slave_indev);
                                dnode->slave_indev = NULL;
                        }
                        dsr_node_unlock(dnode);
		} else if (dev == dnode->slave_dev && dnode->slave_indev) {
			dsr_node_lock(dnode);
			dnode->slave_indev->cnf.rp_filter = rp_filter;
			dnode->slave_indev->cnf.forwarding = forwarding;                                in_dev_put(dnode->slave_indev);
			dnode->slave_indev = NULL;
                        dsr_node_unlock(dnode);
		} 
		break;
	default:
		break;
	};

	return NOTIFY_DONE;
}

static int dsr_dev_start_xmit(struct sk_buff *skb, struct net_device *dev);
static struct net_device_stats *dsr_dev_get_stats(struct net_device *dev);

static int dsr_dev_set_address(struct net_device *dev, void *p)
{
	struct sockaddr *sa = p;

	if (!is_valid_ether_addr(sa->sa_data))
		return -EADDRNOTAVAIL;

	memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
	return 0;
}

/* fake multicast ability */
static void set_multicast_list(struct net_device *dev)
{
}

#ifdef CONFIG_NET_FASTROUTE
static int dsr_dev_accept_fastpath(struct net_device *dev, 
				   struct dst_entry *dst)
{
	return -1;
}
#endif
static int dsr_dev_open(struct net_device *dev)
{
	netif_start_queue(dev);
	return 0;
}

static int dsr_dev_stop(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

static void dsr_dev_uninit(struct net_device *dev)
{
	struct dsr_node *dnode = (struct dsr_node *)dev->priv;

	dsr_node_lock(dnode);
	
	if (dnode->slave_dev)
		dev_put(dnode->slave_dev);

	if (dnode->slave_indev)
		in_dev_put(dnode->slave_indev);

	dsr_node_unlock(dnode);

	if (dsr_packet_type.func) {