mpc.c

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		ddprintk("mpoa: (%s) send_via_shortcut: cache_hit: returns != OPEN\n", mpc->dev->name);        
		mpc->in_ops->put(entry);
		return 1;
	}

	ddprintk("mpoa: (%s) send_via_shortcut: using shortcut\n", mpc->dev->name);        
	/* MPOA spec A.1.4, MPOA client must decrement IP ttl at least by one */
	if (iph->ttl <= 1) {
		ddprintk("mpoa: (%s) send_via_shortcut: IP ttl = %u, using LANE\n", mpc->dev->name, iph->ttl);        
		mpc->in_ops->put(entry);
		return 1;
	}
	iph->ttl--;
	iph->check = 0;
	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);

	if (entry->ctrl_info.tag != 0) {
		ddprintk("mpoa: (%s) send_via_shortcut: adding tag 0x%x\n", mpc->dev->name, entry->ctrl_info.tag);
		tagged_llc_snap_hdr.tag = entry->ctrl_info.tag;
		skb_pull(skb, ETH_HLEN);                       /* get rid of Eth header */
		skb_push(skb, sizeof(tagged_llc_snap_hdr));    /* add LLC/SNAP header   */
		memcpy(skb->data, &tagged_llc_snap_hdr, sizeof(tagged_llc_snap_hdr));
	} else {
		skb_pull(skb, ETH_HLEN);                        /* get rid of Eth header */
		skb_push(skb, sizeof(struct llc_snap_hdr));     /* add LLC/SNAP header + tag  */
		memcpy(skb->data, &llc_snap_mpoa_data, sizeof(struct llc_snap_hdr));
	}

	atomic_add(skb->truesize, &entry->shortcut->tx_inuse);
	ATM_SKB(skb)->iovcnt = 0; /* just to be safe ... */
	ATM_SKB(skb)->atm_options = entry->shortcut->atm_options;
	entry->shortcut->send(entry->shortcut, skb);
	entry->packets_fwded++;
	mpc->in_ops->put(entry);

	return 0;
}

/*
 * Probably needs some error checks and locking, not sure...
 */
static int mpc_send_packet(struct sk_buff *skb, struct net_device *dev)
{
	int retval;
	struct mpoa_client *mpc;
	struct ethhdr *eth;
	int i = 0;
	
	mpc = find_mpc_by_lec(dev); /* this should NEVER fail */
	if(mpc == NULL) {
		printk("mpoa: (%s) mpc_send_packet: no MPC found\n", dev->name);
		goto non_ip;
	}

	eth = (struct ethhdr *)skb->data;
	if (eth->h_proto != htons(ETH_P_IP))
		goto non_ip; /* Multi-Protocol Over ATM :-) */

	while (i < mpc->number_of_mps_macs) {
		if (memcmp(eth->h_dest, (mpc->mps_macs + i*ETH_ALEN), ETH_ALEN) == 0)
			if ( send_via_shortcut(skb, mpc) == 0 )           /* try shortcut */
				return 0;                                 /* success!     */
		i++;
	}

 non_ip:
	retval = mpc->old_hard_start_xmit(skb,dev);
	
	return retval;
}

int atm_mpoa_vcc_attach(struct atm_vcc *vcc, long arg)
{
	int bytes_left;
	struct mpoa_client *mpc;
	struct atmmpc_ioc ioc_data;
	in_cache_entry *in_entry;
	uint32_t  ipaddr;
	unsigned char *ip;

	bytes_left = copy_from_user(&ioc_data, (void *)arg, sizeof(struct atmmpc_ioc));
	if (bytes_left != 0) {
		printk("mpoa: mpc_vcc_attach: Short read (missed %d bytes) from userland\n", bytes_left);
		return -EFAULT;
	}
	ipaddr = ioc_data.ipaddr;
	if (ioc_data.dev_num < 0 || ioc_data.dev_num >= MAX_LEC_ITF)
		return -EINVAL;
	
	mpc = find_mpc_by_itfnum(ioc_data.dev_num);
	if (mpc == NULL)
		return -EINVAL;
	
	if (ioc_data.type == MPC_SOCKET_INGRESS) {
		in_entry = mpc->in_ops->get(ipaddr, mpc);
		if (in_entry == NULL || in_entry->entry_state < INGRESS_RESOLVED) {
			printk("mpoa: (%s) mpc_vcc_attach: did not find RESOLVED entry from ingress cache\n",
				mpc->dev->name);
			if (in_entry != NULL) mpc->in_ops->put(in_entry);
			return -EINVAL;
		}
		ip = (unsigned char*)&in_entry->ctrl_info.in_dst_ip;
		printk("mpoa: (%s) mpc_vcc_attach: attaching ingress SVC, entry = %u.%u.%u.%u\n",
		       mpc->dev->name, ip[0], ip[1], ip[2], ip[3]);
		in_entry->shortcut = vcc;
		mpc->in_ops->put(in_entry);
	} else {
		printk("mpoa: (%s) mpc_vcc_attach: attaching egress SVC\n", mpc->dev->name);
	}

	vcc->proto_data = mpc->dev;
	vcc->push = mpc_push;

	return 0;
}

/*
 *
 */
static void mpc_vcc_close(struct atm_vcc *vcc, struct net_device *dev)
{
	struct mpoa_client *mpc;
	in_cache_entry *in_entry;
	eg_cache_entry *eg_entry;
	
	mpc = find_mpc_by_lec(dev);
	if (mpc == NULL) {
		printk("mpoa: (%s) mpc_vcc_close: close for unknown MPC\n", dev->name);
		return;
	}

	dprintk("mpoa: (%s) mpc_vcc_close:\n", dev->name);
	in_entry = mpc->in_ops->get_by_vcc(vcc, mpc);
	if (in_entry) {
		unsigned char *ip __attribute__ ((unused)) =
		    (unsigned char *)&in_entry->ctrl_info.in_dst_ip;
		dprintk("mpoa: (%s) mpc_vcc_close: ingress SVC closed ip = %u.%u.%u.%u\n",
		       mpc->dev->name, ip[0], ip[1], ip[2], ip[3]);
		in_entry->shortcut = NULL;
		mpc->in_ops->put(in_entry);
	}
	eg_entry = mpc->eg_ops->get_by_vcc(vcc, mpc);
	if (eg_entry) {
		dprintk("mpoa: (%s) mpc_vcc_close: egress SVC closed\n", mpc->dev->name);
		eg_entry->shortcut = NULL;
		mpc->eg_ops->put(eg_entry);
	}

	if (in_entry == NULL && eg_entry == NULL)
		dprintk("mpoa: (%s) mpc_vcc_close:  unused vcc closed\n", dev->name);

	return;
}

static void mpc_push(struct atm_vcc *vcc, struct sk_buff *skb)
{
	struct net_device *dev = (struct net_device *)vcc->proto_data;
	struct sk_buff *new_skb;
	eg_cache_entry *eg;
	struct mpoa_client *mpc;
	uint32_t tag;
	char *tmp;
	
	ddprintk("mpoa: (%s) mpc_push:\n", dev->name);
	if (skb == NULL) {
		dprintk("mpoa: (%s) mpc_push: null skb, closing VCC\n", dev->name);
		mpc_vcc_close(vcc, dev);
		return;
	}
	
	skb->dev = dev;
	if (memcmp(skb->data, &llc_snap_mpoa_ctrl, sizeof(struct llc_snap_hdr)) == 0) {
		dprintk("mpoa: (%s) mpc_push: control packet arrived\n", dev->name);
		skb_queue_tail(&vcc->recvq, skb);           /* Pass control packets to daemon */
		wake_up(&vcc->sleep);
		return;
	}

	/* data coming over the shortcut */
	atm_return(vcc, skb->truesize);

	mpc = find_mpc_by_lec(dev);
	if (mpc == NULL) {
		printk("mpoa: (%s) mpc_push: unknown MPC\n", dev->name);
		return;
	}

	if (memcmp(skb->data, &llc_snap_mpoa_data_tagged, sizeof(struct llc_snap_hdr)) == 0) { /* MPOA tagged data */
		ddprintk("mpoa: (%s) mpc_push: tagged data packet arrived\n", dev->name);

	} else if (memcmp(skb->data, &llc_snap_mpoa_data, sizeof(struct llc_snap_hdr)) == 0) { /* MPOA data */
		printk("mpoa: (%s) mpc_push: non-tagged data packet arrived\n", dev->name);
		printk("           mpc_push: non-tagged data unsupported, purging\n");
		dev_kfree_skb_any(skb);
		return;
	} else {
		printk("mpoa: (%s) mpc_push: garbage arrived, purging\n", dev->name);
		dev_kfree_skb_any(skb);
		return;
	}

	tmp = skb->data + sizeof(struct llc_snap_hdr);
	tag = *(uint32_t *)tmp;

	eg = mpc->eg_ops->get_by_tag(tag, mpc);
	if (eg == NULL) {
		printk("mpoa: (%s) mpc_push: Didn't find egress cache entry, tag = %u\n",
		       dev->name,tag);
		purge_egress_shortcut(vcc, NULL);
		dev_kfree_skb_any(skb);
		return;
	}
	
	/*
	 * See if ingress MPC is using shortcut we opened as a return channel.
	 * This means we have a bi-directional vcc opened by us.
	 */ 
	if (eg->shortcut == NULL) {
		eg->shortcut = vcc;
		printk("mpoa: (%s) mpc_push: egress SVC in use\n", dev->name);
	}

	skb_pull(skb, sizeof(struct llc_snap_hdr) + sizeof(tag)); /* get rid of LLC/SNAP header */
	new_skb = skb_realloc_headroom(skb, eg->ctrl_info.DH_length); /* LLC/SNAP is shorter than MAC header :( */
	dev_kfree_skb_any(skb);
	if (new_skb == NULL){
		mpc->eg_ops->put(eg);
		return;
	}
	skb_push(new_skb, eg->ctrl_info.DH_length);     /* add MAC header */
	memcpy(new_skb->data, eg->ctrl_info.DLL_header, eg->ctrl_info.DH_length);
	new_skb->protocol = eth_type_trans(new_skb, dev);
	new_skb->nh.raw = new_skb->data;

	eg->latest_ip_addr = new_skb->nh.iph->saddr;
	eg->packets_rcvd++;
	mpc->eg_ops->put(eg);

	netif_rx(new_skb);

	return;
}

static struct atmdev_ops mpc_ops = { /* only send is required */
	close:	mpoad_close,
	send:	msg_from_mpoad
};

static struct atm_dev mpc_dev = {
	&mpc_ops,       /* device operations    */
	NULL,           /* PHY operations       */
	"mpc",          /* device type name     */
	42,             /* device index (dummy) */
	NULL,           /* VCC table            */
	NULL,           /* last VCC             */
	NULL,           /* per-device data      */
	NULL,           /* private PHY data     */
	{ 0 },          /* device flags         */
	NULL,           /* local ATM address    */
	{ 0 }           /* no ESI               */
	/* rest of the members will be 0 */
};

int atm_mpoa_mpoad_attach (struct atm_vcc *vcc, int arg)
{
	struct mpoa_client *mpc;
	struct lec_priv *priv;
	
	if (mpcs == NULL) {
		init_timer(&mpc_timer);
		mpc_timer_refresh();

		/* This lets us now how our LECs are doing */
		register_netdevice_notifier(&mpoa_notifier);
	}
	
	mpc = find_mpc_by_itfnum(arg);
	if (mpc == NULL) {
		dprintk("mpoa: mpoad_attach: allocating new mpc for itf %d\n", arg);
		mpc = alloc_mpc();
		mpc->dev_num = arg;
		mpc->dev = find_lec_by_itfnum(arg); /* NULL if there was no lec */
	}
	if (mpc->mpoad_vcc) {
		printk("mpoa: mpoad_attach: mpoad is already present for itf %d\n", arg);
		return -EADDRINUSE;
	}

	if (mpc->dev) { /* check if the lec is LANE2 capable */
		priv = (struct lec_priv *)mpc->dev->priv;
		if (priv->lane_version < 2)
			mpc->dev = NULL;
		else
			priv->lane2_ops->associate_indicator = lane2_assoc_ind;  
	}

	mpc->mpoad_vcc = vcc;
	bind_vcc(vcc, &mpc_dev);
	set_bit(ATM_VF_META,&vcc->flags);
	set_bit(ATM_VF_READY,&vcc->flags);

	if (mpc->dev) {
		char empty[ATM_ESA_LEN];
		memset(empty, 0, ATM_ESA_LEN);
		
		start_mpc(mpc, mpc->dev);
		/* set address if mpcd e.g. gets killed and restarted.
		 * If we do not do it now we have to wait for the next LE_ARP
		 */
		if ( memcmp(mpc->mps_ctrl_addr, empty, ATM_ESA_LEN) != 0 )
			send_set_mps_ctrl_addr(mpc->mps_ctrl_addr, mpc);
	}

	MOD_INC_USE_COUNT;
	return arg;
}

static void send_set_mps_ctrl_addr(char *addr, struct mpoa_client *mpc)
{
	struct k_message mesg;

	memcpy (mpc->mps_ctrl_addr, addr, ATM_ESA_LEN);
	
	mesg.type = SET_MPS_CTRL_ADDR;
	memcpy(mesg.MPS_ctrl, addr, ATM_ESA_LEN);
	msg_to_mpoad(&mesg, mpc);

	return;
}

static void mpoad_close(struct atm_vcc *vcc)
{
	struct mpoa_client *mpc;
	struct sk_buff *skb;

	mpc = find_mpc_by_vcc(vcc);
	if (mpc == NULL) {
		printk("mpoa: mpoad_close: did not find MPC\n");
		return;
	}
	if (!mpc->mpoad_vcc) {
		printk("mpoa: mpoad_close: close for non-present mpoad\n");
		return;
	}
	
	mpc->mpoad_vcc = NULL;
	if (mpc->dev) {
		struct lec_priv *priv = (struct lec_priv *)mpc->dev->priv;
		priv->lane2_ops->associate_indicator = NULL;
		stop_mpc(mpc);
	}

	mpc->in_ops->destroy_cache(mpc);
	mpc->eg_ops->destroy_cache(mpc);

	while ( (skb = skb_dequeue(&vcc->recvq)) ){
		atm_return(vcc, skb->truesize);
		kfree_skb(skb);
	}
	
	printk("mpoa: (%s) going down\n",
		(mpc->dev) ? mpc->dev->name : "<unknown>");
	MOD_DEC_USE_COUNT;

	return;
}

/*
 *
 */
static int msg_from_mpoad(struct atm_vcc *vcc, struct sk_buff *skb)
{
	
	struct mpoa_client *mpc = find_mpc_by_vcc(vcc);
	struct k_message *mesg = (struct k_message*)skb->data;
	atomic_sub(skb->truesize+ATM_PDU_OVHD, &vcc->tx_inuse);
	
	if (mpc == NULL) {
		printk("mpoa: msg_from_mpoad: no mpc found\n");
		return 0;
	}
	dprintk("mpoa: (%s) msg_from_mpoad:", (mpc->dev) ? mpc->dev->name : "<unknown>");
	switch(mesg->type) {
	case MPOA_RES_REPLY_RCVD:
		dprintk(" mpoa_res_reply_rcvd\n");
		MPOA_res_reply_rcvd(mesg, mpc);
		break;
	case MPOA_TRIGGER_RCVD:
		dprintk(" mpoa_trigger_rcvd\n");
		MPOA_trigger_rcvd(mesg, mpc);
		break;
	case INGRESS_PURGE_RCVD:
		dprintk(" nhrp_purge_rcvd\n");
		ingress_purge_rcvd(mesg, mpc);
		break;
	case EGRESS_PURGE_RCVD:
		dprintk(" egress_purge_reply_rcvd\n");
		egress_purge_rcvd(mesg, mpc);
		break;
	case MPS_DEATH:
		dprintk(" mps_death\n");
		mps_death(mesg, mpc);
		break;
	case CACHE_IMPOS_RCVD:
		dprintk(" cache_impos_rcvd\n");
		MPOA_cache_impos_rcvd(mesg, mpc);
		break;
	case SET_MPC_CTRL_ADDR:
		dprintk(" set_mpc_ctrl_addr\n");
		set_mpc_ctrl_addr_rcvd(mesg, mpc);
		break;
	case SET_MPS_MAC_ADDR:
		dprintk(" set_mps_mac_addr\n");
		set_mps_mac_addr_rcvd(mesg, mpc);
		break;
	case CLEAN_UP_AND_EXIT:
		dprintk(" clean_up_and_exit\n");
		clean_up(mesg, mpc, DIE);
		break;
	case RELOAD:
		dprintk(" reload\n");
		clean_up(mesg, mpc, RELOAD);
		break;
	case SET_MPC_PARAMS:
		dprintk(" set_mpc_params\n");
		mpc->parameters = mesg->content.params;
		break;
	default:
		dprintk(" unknown message %d\n", mesg->type);
		break;
	}
	kfree_skb(skb);

	return 0;
}

/* Remember that this function may not do things that sleep */
int msg_to_mpoad(struct k_message *mesg, struct mpoa_client *mpc)
{
	struct sk_buff *skb;

	if (mpc == NULL || !mpc->mpoad_vcc) {
		printk("mpoa: msg_to_mpoad: mesg %d to a non-existent mpoad\n", mesg->type);
		return -ENXIO;
	}

	skb = alloc_skb(sizeof(struct k_message), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;
	skb_put(skb, sizeof(struct k_message));
	memcpy(skb->data, mesg, sizeof(struct k_message));
	atm_force_charge(mpc->mpoad_vcc, skb->truesize);
	skb_queue_tail(&mpc->mpoad_vcc->recvq, skb);
	wake_up(&mpc->mpoad_vcc->sleep);

	return 0;
}

static int mpoa_event_listener(struct notifier_block *mpoa_notifier, unsigned long event, void *dev_ptr)
{
	struct net_device *dev;
	struct mpoa_client *mpc;
	struct lec_priv *priv;

	dev = (struct net_device *)dev_ptr;
	if (dev->name == NULL || strncmp(dev->name, "lec", 3))
		return NOTIFY_DONE; /* we are only interested in lec:s */
	
	switch (event) {
	case NETDEV_REGISTER:       /* a new lec device was allocated */
		priv = (struct lec_priv *)dev->priv;
		if (priv->lane_version < 2)
			break;
		priv->lane2_ops->associate_indicator = lane2_assoc_ind;
		mpc = find_mpc_by_itfnum(priv->itfnum);
		if (mpc == NULL) {
			dprintk("mpoa: mpoa_event_listener: allocating new mpc for %s\n",
			       dev->name);
			mpc = alloc_mpc();
			if (mpc == NULL) {
				printk("mpoa: mpoa_event_listener: no new mpc");
				break;
			}
		}
		mpc->dev_num = priv->itfnum;
		mpc->dev = dev;
		dprintk("mpoa: (%s) was initialized\n", dev->name);
		break;
	case NETDEV_UNREGISTER:
		/* the lec device was deallocated */
		mpc = find_mpc_by_lec(dev);
		if (mpc == NULL)
			break;
		dprintk("mpoa: device (%s) was deallocated\n", dev->name);