#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/slab.h>

#include <linux/timer.h>

#include <linux/init.h>

#include <linux/bitops.h>

#include <linux/capability.h>

#include <linux/seq_file.h>

/* We are an ethernet device */

#include <linux/if_ether.h>

#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <net/sock.h>

#include <linux/skbuff.h>

#include <linux/ip.h>

#include <linux/uaccess.h>

#include <asm/byteorder.h>

#include <net/checksum.h>   /* for ip_fast_csum() */

#include <net/arp.h>

#include <net/dst.h>

#include <linux/proc_fs.h>

/* And atm device */

#include <linux/atmdev.h>

#include <linux/atmlec.h>

#include <linux/atmmpc.h>

/* Modular too */

#include <linux/module.h>

#include "lec.h"

#include "mpc.h"

#include "resources.h"

/*

 * mpc.c: Implementation of MPOA client kernel part

 */

#if 0

#define dprintk(format, args...) \

	printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args)

#define dprintk_cont(format, args...) printk(KERN_CONT format, ##args)

#else

#define dprintk(format, args...)					\

	do { if (0)							\

		printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args);\

	} while (0)

#define dprintk_cont(format, args...)			\

	do { if (0) printk(KERN_CONT format, ##args); } while (0)

#endif

#if 0

#define ddprintk(format, args...) \

	printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args)

#define ddprintk_cont(format, args...) printk(KERN_CONT format, ##args)

#else

#define ddprintk(format, args...)					\

	do { if (0)							\

		printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args);\

	} while (0)

#define ddprintk_cont(format, args...)			\

	do { if (0) printk(KERN_CONT format, ##args); } while (0)

#endif

/* mpc_daemon -> kernel */

static void MPOA_trigger_rcvd(struct k_message *msg, struct mpoa_client *mpc);

static void MPOA_res_reply_rcvd(struct k_message *msg, struct mpoa_client *mpc);

static void ingress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc);

static void egress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc);

static void mps_death(struct k_message *msg, struct mpoa_client *mpc);

static void clean_up(struct k_message *msg, struct mpoa_client *mpc,

		     int action);

static void MPOA_cache_impos_rcvd(struct k_message *msg,

				  struct mpoa_client *mpc);

static void set_mpc_ctrl_addr_rcvd(struct k_message *mesg,

				   struct mpoa_client *mpc);

static void set_mps_mac_addr_rcvd(struct k_message *mesg,

				  struct mpoa_client *mpc);

static const uint8_t *copy_macs(struct mpoa_client *mpc,

				const uint8_t *router_mac,

				const uint8_t *tlvs, uint8_t mps_macs,

				uint8_t device_type);

static void purge_egress_shortcut(struct atm_vcc *vcc, eg_cache_entry *entry);

static void send_set_mps_ctrl_addr(const char *addr, struct mpoa_client *mpc);

static void mpoad_close(struct atm_vcc *vcc);

static int msg_from_mpoad(struct atm_vcc *vcc, struct sk_buff *skb);

static void mpc_push(struct atm_vcc *vcc, struct sk_buff *skb);

static netdev_tx_t mpc_send_packet(struct sk_buff *skb,

				   struct net_device *dev);

static int mpoa_event_listener(struct notifier_block *mpoa_notifier,

			       unsigned long event, void *dev);

static void mpc_timer_refresh(void);

static void mpc_cache_check(struct timer_list *unused);

static struct llc_snap_hdr llc_snap_mpoa_ctrl = {

	0xaa, 0xaa, 0x03,

	{0x00, 0x00, 0x5e},

	{0x00, 0x03}         /* For MPOA control PDUs */

};

static struct llc_snap_hdr llc_snap_mpoa_data = {

	0xaa, 0xaa, 0x03,

	{0x00, 0x00, 0x00},

	{0x08, 0x00}         /* This is for IP PDUs only */

};

static struct llc_snap_hdr llc_snap_mpoa_data_tagged = {

	0xaa, 0xaa, 0x03,

	{0x00, 0x00, 0x00},

	{0x88, 0x4c}         /* This is for tagged data PDUs */

};

static struct notifier_block mpoa_notifier = {

	mpoa_event_listener,

	NULL,

	0

};

struct mpoa_client *mpcs = NULL; /* FIXME */

static struct atm_mpoa_qos *qos_head = NULL;

static DEFINE_TIMER(mpc_timer, mpc_cache_check);

static struct mpoa_client *find_mpc_by_itfnum(int itf)

{

	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */

	while (mpc != NULL) {

		if (mpc->dev_num == itf)

			return mpc;

		mpc = mpc->next;

	}

	return NULL;   /* not found */

}

static struct mpoa_client *find_mpc_by_vcc(struct atm_vcc *vcc)

{

	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */

	while (mpc != NULL) {

		if (mpc->mpoad_vcc == vcc)

			return mpc;

		mpc = mpc->next;

	}

	return NULL;   /* not found */

}

static struct mpoa_client *find_mpc_by_lec(struct net_device *dev)

{

	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */

	while (mpc != NULL) {

		if (mpc->dev == dev)

			return mpc;

		mpc = mpc->next;

	}

	return NULL;   /* not found */

}

/*

 * Functions for managing QoS list

 */

/*

 * Overwrites the old entry or makes a new one.

 */

struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos)

{

	struct atm_mpoa_qos *entry;

	entry = atm_mpoa_search_qos(dst_ip);

	if (entry != NULL) {

		entry->qos = *qos;

		return entry;

	}

	entry = kmalloc(sizeof(struct atm_mpoa_qos), GFP_KERNEL);

	if (entry == NULL) {

		pr_info("mpoa: out of memory\n");

		return entry;

	}

	entry->ipaddr = dst_ip;

	entry->qos = *qos;

	entry->next = qos_head;

	qos_head = entry;

	return entry;

}

struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip)

{

	struct atm_mpoa_qos *qos;

	qos = qos_head;

	while (qos) {

		if (qos->ipaddr == dst_ip)

			break;

		qos = qos->next;

	}

	return qos;

}

/*

 * Returns 0 for failure

 */

int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry)

{

	struct atm_mpoa_qos *curr;

	if (entry == NULL)

		return 0;

	if (entry == qos_head) {

		qos_head = qos_head->next;

		kfree(entry);

		return 1;

	}

	curr = qos_head;

	while (curr != NULL) {

		if (curr->next == entry) {

			curr->next = entry->next;

			kfree(entry);

			return 1;

		}

		curr = curr->next;

	}

	return 0;

}

/* this is buggered - we need locking for qos_head */

void atm_mpoa_disp_qos(struct seq_file *m)

{

	struct atm_mpoa_qos *qos;

	qos = qos_head;

	seq_printf(m, "QoS entries for shortcuts:\n");

	seq_printf(m, "IP address\n  TX:max_pcr pcr     min_pcr max_cdv max_sdu\n  RX:max_pcr pcr     min_pcr max_cdv max_sdu\n");

	while (qos != NULL) {

		seq_printf(m, "%pI4\n     %-7d %-7d %-7d %-7d %-7d\n     %-7d %-7d %-7d %-7d %-7d\n",

			   &qos->ipaddr,

			   qos->qos.txtp.max_pcr,

			   qos->qos.txtp.pcr,

			   qos->qos.txtp.min_pcr,

			   qos->qos.txtp.max_cdv,

			   qos->qos.txtp.max_sdu,

			   qos->qos.rxtp.max_pcr,

			   qos->qos.rxtp.pcr,

			   qos->qos.rxtp.min_pcr,

			   qos->qos.rxtp.max_cdv,

			   qos->qos.rxtp.max_sdu);

		qos = qos->next;

	}

}

static struct net_device *find_lec_by_itfnum(int itf)

{

	struct net_device *dev;

	char name[IFNAMSIZ];

	sprintf(name, "lec%d", itf);

	dev = dev_get_by_name(&init_net, name);

	return dev;

}

static struct mpoa_client *alloc_mpc(void)

{

	struct mpoa_client *mpc;

	mpc = kzalloc(sizeof(struct mpoa_client), GFP_KERNEL);

	if (mpc == NULL)

		return NULL;

	rwlock_init(&mpc->ingress_lock);

	rwlock_init(&mpc->egress_lock);

	mpc->next = mpcs;

	atm_mpoa_init_cache(mpc);

	mpc->parameters.mpc_p1 = MPC_P1;

	mpc->parameters.mpc_p2 = MPC_P2;

	memset(mpc->parameters.mpc_p3, 0, sizeof(mpc->parameters.mpc_p3));

	mpc->parameters.mpc_p4 = MPC_P4;

	mpc->parameters.mpc_p5 = MPC_P5;

	mpc->parameters.mpc_p6 = MPC_P6;

	mpcs = mpc;

	return mpc;

}

/*

 *

 * start_mpc() puts the MPC on line. All the packets destined

 * to the lec underneath us are now being monitored and

 * shortcuts will be established.

 *

 */

static void start_mpc(struct mpoa_client *mpc, struct net_device *dev)

{

	dprintk("(%s)\n", mpc->dev->name);

	if (!dev->netdev_ops)

		pr_info("(%s) not starting\n", dev->name);

	else {

		mpc->old_ops = dev->netdev_ops;

		mpc->new_ops = *mpc->old_ops;

		mpc->new_ops.ndo_start_xmit = mpc_send_packet;

		dev->netdev_ops = &mpc->new_ops;

	}

}

static void stop_mpc(struct mpoa_client *mpc)

{

	struct net_device *dev = mpc->dev;

	dprintk("(%s)", mpc->dev->name);

	/* Lets not nullify lec device's dev->hard_start_xmit */

	if (dev->netdev_ops != &mpc->new_ops) {

		dprintk_cont(" mpc already stopped, not fatal\n");

		return;

	}

	dprintk_cont("\n");

	dev->netdev_ops = mpc->old_ops;

	mpc->old_ops = NULL;

	/* close_shortcuts(mpc);    ??? FIXME */

}

static const char *mpoa_device_type_string(char type) __attribute__ ((unused));

static const char *mpoa_device_type_string(char type)

{

	switch (type) {

	case NON_MPOA:

		return "non-MPOA device";

	case MPS:

		return "MPS";

	case MPC:

		return "MPC";

	case MPS_AND_MPC:

		return "both MPS and MPC";

	}

	return "unspecified (non-MPOA) device";

}

/*

 * lec device calls this via its netdev_priv(dev)->lane2_ops

 * ->associate_indicator() when it sees a TLV in LE_ARP packet.

 * We fill in the pointer above when we see a LANE2 lec initializing

 * See LANE2 spec 3.1.5

 *

 * Quite a big and ugly function but when you look at it

 * all it does is to try to locate and parse MPOA Device

 * Type TLV.

 * We give our lec a pointer to this function and when the

 * lec sees a TLV it uses the pointer to call this function.

 *

 */

static void lane2_assoc_ind(struct net_device *dev, const u8 *mac_addr,

			    const u8 *tlvs, u32 sizeoftlvs)

{

	uint32_t type;

	uint8_t length, mpoa_device_type, number_of_mps_macs;

	const uint8_t *end_of_tlvs;

	struct mpoa_client *mpc;

	mpoa_device_type = number_of_mps_macs = 0; /* silence gcc */

	dprintk("(%s) received TLV(s), ", dev->name);

	dprintk("total length of all TLVs %d\n", sizeoftlvs);

	mpc = find_mpc_by_lec(dev); /* Sampo-Fix: moved here from below */

	if (mpc == NULL) {

		pr_info("(%s) no mpc\n", dev->name);

		return;

	}

	end_of_tlvs = tlvs + sizeoftlvs;

	while (end_of_tlvs - tlvs >= 5) {

		type = ((tlvs[0] << 24) | (tlvs[1] << 16) |

			(tlvs[2] << 8) | tlvs[3]);

		length = tlvs[4];

		tlvs += 5;

		dprintk("    type 0x%x length %02x\n", type, length);

		if (tlvs + length > end_of_tlvs) {

			pr_info("TLV value extends past its buffer, aborting parse\n");

			return;

		}

		if (type == 0) {

			pr_info("mpoa: (%s) TLV type was 0, returning\n",

				dev->name);

			return;

		}

		if (type != TLV_MPOA_DEVICE_TYPE) {

			tlvs += length;

			continue;  /* skip other TLVs */

		}

		mpoa_device_type = *tlvs++;

		number_of_mps_macs = *tlvs++;

		dprintk("(%s) MPOA device type '%s', ",

			dev->name, mpoa_device_type_string(mpoa_device_type));

		if (mpoa_device_type == MPS_AND_MPC &&

		    length < (42 + number_of_mps_macs*ETH_ALEN)) { /* :) */

			pr_info("(%s) short MPOA Device Type TLV\n",

				dev->name);

			continue;

		}

		if ((mpoa_device_type == MPS || mpoa_device_type == MPC) &&

		    length < 22 + number_of_mps_macs*ETH_ALEN) {

			pr_info("(%s) short MPOA Device Type TLV\n", dev->name);

			continue;

		}

		if (mpoa_device_type != MPS &&

		    mpoa_device_type != MPS_AND_MPC) {

			dprintk("ignoring non-MPS device ");

			if (mpoa_device_type == MPC)

				tlvs += 20;

			continue;  /* we are only interested in MPSs */

		}

		if (number_of_mps_macs == 0 &&

		    mpoa_device_type == MPS_AND_MPC) {

			pr_info("(%s) MPS_AND_MPC has zero MACs\n", dev->name);

			continue;  /* someone should read the spec */

		}

		dprintk_cont("this MPS has %d MAC addresses\n",

			     number_of_mps_macs);

		/*

		 * ok, now we can go and tell our daemon

		 * the control address of MPS

		 */

		send_set_mps_ctrl_addr(tlvs, mpc);

		tlvs = copy_macs(mpc, mac_addr, tlvs,

				 number_of_mps_macs, mpoa_device_type);

		if (tlvs == NULL)

			return;

	}

	if (end_of_tlvs - tlvs != 0)

		pr_info("(%s) ignoring %zd bytes of trailing TLV garbage\n",

			dev->name, end_of_tlvs - tlvs);

}

/*

 * Store at least advertizing router's MAC address

 * plus the possible MAC address(es) to mpc->mps_macs.

 * For a freshly allocated MPOA client mpc->mps_macs == 0.

 */

static const uint8_t *copy_macs(struct mpoa_client *mpc,

				const uint8_t *router_mac,

				const uint8_t *tlvs, uint8_t mps_macs,

				uint8_t device_type)

{

	int num_macs;

	num_macs = (mps_macs > 1) ? mps_macs : 1;

	if (mpc->number_of_mps_macs != num_macs) { /* need to reallocate? */

		if (mpc->number_of_mps_macs != 0)

			kfree(mpc->mps_macs);

		mpc->number_of_mps_macs = 0;

		mpc->mps_macs = kmalloc_array(ETH_ALEN, num_macs, GFP_KERNEL);

		if (mpc->mps_macs == NULL) {

			pr_info("(%s) out of mem\n", mpc->dev->name);

			return NULL;

		}

	}

	ether_addr_copy(mpc->mps_macs, router_mac);

	tlvs += 20; if (device_type == MPS_AND_MPC) tlvs += 20;

	if (mps_macs > 0)

		memcpy(mpc->mps_macs, tlvs, mps_macs*ETH_ALEN);

	tlvs += mps_macs*ETH_ALEN;

	mpc->number_of_mps_macs = num_macs;

	return tlvs;

}

static int send_via_shortcut(struct sk_buff *skb, struct mpoa_client *mpc)

{

	in_cache_entry *entry;

	struct iphdr *iph;

	char *buff;

	__be32 ipaddr = 0;

	static struct {

		struct llc_snap_hdr hdr;

		__be32 tag;

	} tagged_llc_snap_hdr = {

		{0xaa, 0xaa, 0x03, {0x00, 0x00, 0x00}, {0x88, 0x4c}},

		0

	};

	buff = skb->data + mpc->dev->hard_header_len;

	iph = (struct iphdr *)buff;

	ipaddr = iph->daddr;

	ddprintk("(%s) ipaddr 0x%x\n",

		 mpc->dev->name, ipaddr);

	entry = mpc->in_ops->get(ipaddr, mpc);

	if (entry == NULL) {

		entry = mpc->in_ops->add_entry(ipaddr, mpc);

		if (entry != NULL)

			mpc->in_ops->put(entry);

		return 1;

	}

	/* threshold not exceeded or VCC not ready */

	if (mpc->in_ops->cache_hit(entry, mpc) != OPEN) {

		ddprintk("(%s) cache_hit: returns != OPEN\n",

			 mpc->dev->name);

		mpc->in_ops->put(entry);

		return 1;

	}

	ddprintk("(%s) 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("(%s) 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("(%s) 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   */

		skb_copy_to_linear_data(skb, &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  */

		skb_copy_to_linear_data(skb, &llc_snap_mpoa_data,

					sizeof(struct llc_snap_hdr));

	}

	atm_account_tx(entry->shortcut, skb);

	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 netdev_tx_t mpc_send_packet(struct sk_buff *skb,

					 struct net_device *dev)

{

	struct mpoa_client *mpc;

	struct ethhdr *eth;

	int i = 0;

	mpc = find_mpc_by_lec(dev); /* this should NEVER fail */

	if (mpc == NULL) {

		pr_info("(%s) 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 :-) */

	/* Weed out funny packets (e.g., AF_PACKET or raw). */

	if (skb->len < ETH_HLEN + sizeof(struct iphdr))

		goto non_ip;

	skb_set_network_header(skb, ETH_HLEN);

	if (skb->len < ETH_HLEN + ip_hdr(skb)->ihl * 4 || ip_hdr(skb)->ihl < 5)

		goto non_ip;

	while (i < mpc->number_of_mps_macs) {

		if (ether_addr_equal(eth->h_dest, mpc->mps_macs + i * ETH_ALEN))

			if (send_via_shortcut(skb, mpc) == 0) /* try shortcut */

				return NETDEV_TX_OK;

		i++;

	}

non_ip:

	return __netdev_start_xmit(mpc->old_ops, skb, dev, false);

}

static int atm_mpoa_vcc_attach(struct atm_vcc *vcc, void __user *arg)

{

	int bytes_left;

	struct mpoa_client *mpc;

	struct atmmpc_ioc ioc_data;

	in_cache_entry *in_entry;

	__be32  ipaddr;

	bytes_left = copy_from_user(&ioc_data, arg, sizeof(struct atmmpc_ioc));

	if (bytes_left != 0) {

		pr_info("mpoa: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) {

			pr_info("(%s) did not find RESOLVED entry from ingress cache\n",

				mpc->dev->name);

			if (in_entry != NULL)

				mpc->in_ops->put(in_entry);

			return -EINVAL;

		}

		pr_info("(%s) attaching ingress SVC, entry = %pI4\n",

			mpc->dev->name, &in_entry->ctrl_info.in_dst_ip);

		in_entry->shortcut = vcc;

		mpc->in_ops->put(in_entry);

	} else {

		pr_info("(%s) 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) {

		pr_info("(%s) close for unknown MPC\n", dev->name);

		return;

	}

	dprintk("(%s)\n", dev->name);

	in_entry = mpc->in_ops->get_by_vcc(vcc, mpc);

	if (in_entry) {

		dprintk("(%s) ingress SVC closed ip = %pI4\n",

			mpc->dev->name, &in_entry->ctrl_info.in_dst_ip);

		in_entry->shortcut = NULL;

		mpc->in_ops->put(in_entry);

	}

	eg_entry = mpc->eg_ops->get_by_vcc(vcc, mpc);

	if (eg_entry) {

		dprintk("(%s) 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("(%s) unused vcc closed\n", dev->name);

}

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;

	__be32 tag;

	char *tmp;

	ddprintk("(%s)\n", dev->name);

	if (skb == NULL) {

		dprintk("(%s) 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) {

		struct sock *sk = sk_atm(vcc);

		dprintk("(%s) control packet arrived\n", dev->name);

		/* Pass control packets to daemon */

		skb_queue_tail(&sk->sk_receive_queue, skb);

		sk->sk_data_ready(sk);

		return;

	}

	/* data coming over the shortcut */

	atm_return(vcc, skb->truesize);

	mpc = find_mpc_by_lec(dev);

	if (mpc == NULL) {

		pr_info("(%s) 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("(%s) tagged data packet arrived\n", dev->name);

	} else if (memcmp(skb->data, &llc_snap_mpoa_data,

			  sizeof(struct llc_snap_hdr)) == 0) { /* MPOA data */

		pr_info("(%s) Unsupported non-tagged data packet arrived.  Purging\n",

			dev->name);

		dev_kfree_skb_any(skb);

		return;

	} else {

		pr_info("(%s) garbage arrived, purging\n", dev->name);

		dev_kfree_skb_any(skb);

		return;

	}

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

	tag = *(__be32 *)tmp;

	eg = mpc->eg_ops->get_by_tag(tag, mpc);

	if (eg == NULL) {

		pr_info("mpoa: (%s) 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;

		pr_info("(%s) 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 */

	skb_copy_to_linear_data(new_skb, eg->ctrl_info.DLL_header,

				eg->ctrl_info.DH_length);

	new_skb->protocol = eth_type_trans(new_skb, dev);

	skb_reset_network_header(new_skb);

	eg->latest_ip_addr = ip_hdr(new_skb)->saddr;

	eg->packets_rcvd++;

	mpc->eg_ops->put(eg);

	memset(ATM_SKB(new_skb), 0, sizeof(struct atm_skb_data));

	netif_rx(new_skb);

}

static const struct atmdev_ops mpc_ops = { /* only send is required */

	.close	= mpoad_close,

	.send	= msg_from_mpoad

};

static struct atm_dev mpc_dev = {

	.ops	= &mpc_ops,

	.type	= "mpc",

	.number	= 42,

	.lock	= __SPIN_LOCK_UNLOCKED(mpc_dev.lock)

	/* members not explicitly initialised will be 0 */

};

static int atm_mpoa_mpoad_attach(struct atm_vcc *vcc, int arg)

{

	struct mpoa_client *mpc;

	struct lec_priv *priv;

	int err;

	if (mpcs == NULL) {

		mpc_timer_refresh();

		/* This lets us now how our LECs are doing */

		err = register_netdevice_notifier(&mpoa_notifier);

		if (err < 0) {

			del_timer(&mpc_timer);

			return err;

		}

	}

	mpc = find_mpc_by_itfnum(arg);

	if (mpc == NULL) {

		dprintk("allocating new mpc for itf %d\n", arg);

		mpc = alloc_mpc();

		if (mpc == NULL)

			return -ENOMEM;

		mpc->dev_num = arg;

		mpc->dev = find_lec_by_itfnum(arg);

					/* NULL if there was no lec */

	}

	if (mpc->mpoad_vcc) {

		pr_info("mpoad is already present for itf %d\n", arg);

		return -EADDRINUSE;

	}

	if (mpc->dev) { /* check if the lec is LANE2 capable */

		priv = netdev_priv(mpc->dev);

		if (priv->lane_version < 2) {

			dev_put(mpc->dev);

			mpc->dev = NULL;

		} else

			priv->lane2_ops->associate_indicator = lane2_assoc_ind;

	}

	mpc->mpoad_vcc = vcc;

	vcc->dev = &mpc_dev;

	vcc_insert_socket(sk_atm(vcc));

	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);

	}

	__module_get(THIS_MODULE);

	return arg;

}

static void send_set_mps_ctrl_addr(const 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);

}

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) {

		pr_info("did not find MPC\n");

		return;

	}

	if (!mpc->mpoad_vcc) {

		pr_info("close for non-present mpoad\n");

		return;