mpc.c

Go to the documentation of this file.

#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(unsigned long checking_time);

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, NULL, 0, 0);


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(num_macs * ETH_ALEN, GFP_KERNEL);
        if (mpc->mps_macs == NULL) {
            pr_info("(%s) out of mem\n", mpc->dev->name);
            return NULL;
        }
    }
    memcpy(mpc->mps_macs, router_mac, ETH_ALEN);
    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));
    }

    atomic_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc);
    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 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 mpc->old_ops->ndo_start_xmit(skb, dev);
}

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, skb->len);
        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 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) {
        init_timer(&mpc_timer);
        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;
    }

    mpc->mpoad_vcc = NULL;
    if (mpc->dev) {
        struct lec_priv *priv = netdev_priv(mpc->dev);
        priv->lane2_ops->associate_indicator = NULL;
        stop_mpc(mpc);
        dev_put(mpc->dev);
    }

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

    while ((skb = skb_dequeue(&sk_atm(vcc)->sk_receive_queue))) {
        atm_return(vcc, skb->truesize);
        kfree_skb(skb);
    }

    pr_info("(%s) going down\n",
        (mpc->dev) ? mpc->dev->name : "<unknown>");
    module_put(THIS_MODULE);
}

/*
 *
 */
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, &sk_atm(vcc)->sk_wmem_alloc);

    if (mpc == NULL) {
        pr_info("no mpc found\n");
        return 0;
    }
    dprintk("(%s)", mpc->dev ? mpc->dev->name : "<unknown>");
    switch (mesg->type) {
    case MPOA_RES_REPLY_RCVD:
        dprintk_cont("mpoa_res_reply_rcvd\n");
        MPOA_res_reply_rcvd(mesg, mpc);
        break;
    case MPOA_TRIGGER_RCVD:
        dprintk_cont("mpoa_trigger_rcvd\n");
        MPOA_trigger_rcvd(mesg, mpc);
        break;
    case INGRESS_PURGE_RCVD:
        dprintk_cont("nhrp_purge_rcvd\n");
        ingress_purge_rcvd(mesg, mpc);
        break;
    case EGRESS_PURGE_RCVD:
        dprintk_cont("egress_purge_reply_rcvd\n");
        egress_purge_rcvd(mesg, mpc);
        break;
    case MPS_DEATH:
        dprintk_cont("mps_death\n");
        mps_death(mesg, mpc);
        break;
    case CACHE_IMPOS_RCVD:
        dprintk_cont("cache_impos_rcvd\n");
        MPOA_cache_impos_rcvd(mesg, mpc);
        break;
    case SET_MPC_CTRL_ADDR:
        dprintk_cont("set_mpc_ctrl_addr\n");
        set_mpc_ctrl_addr_rcvd(mesg, mpc);
        break;
    case SET_MPS_MAC_ADDR:
        dprintk_cont("set_mps_mac_addr\n");
        set_mps_mac_addr_rcvd(mesg, mpc);
        break;
    case CLEAN_UP_AND_EXIT:
        dprintk_cont("clean_up_and_exit\n");
        clean_up(mesg, mpc, DIE);
        break;
    case RELOAD:
        dprintk_cont("reload\n");
        clean_up(mesg, mpc, RELOAD);
        break;
    case SET_MPC_PARAMS:
        dprintk_cont("set_mpc_params\n");
        mpc->parameters = mesg->content.params;
        break;
    default:
        dprintk_cont("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;
    struct sock *sk;

    if (mpc == NULL || !mpc->mpoad_vcc) {
        pr_info("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));
    skb_copy_to_linear_data(skb, mesg, sizeof(*mesg));
    atm_force_charge(mpc->mpoad_vcc, skb->truesize);

    sk = sk_atm(mpc->mpoad_vcc);
    skb_queue_tail(&sk->sk_receive_queue, skb);
    sk->sk_data_ready(sk, skb->len);

    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 = dev_ptr;

    if (!net_eq(dev_net(dev), &init_net))
        return NOTIFY_DONE;

    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 = netdev_priv(dev);
        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("allocating new mpc for %s\n", dev->name);
            mpc = alloc_mpc();
            if (mpc == NULL) {
                pr_info("no new mpc");
                break;
            }
        }
        mpc->dev_num = priv->itfnum;
        mpc->dev = dev;
        dev_hold(dev);
        dprintk("(%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("device (%s) was deallocated\n", dev->name);
        stop_mpc(mpc);
        dev_put(mpc->dev);
        mpc->dev = NULL;
        break;
    case NETDEV_UP:
        /* the dev was ifconfig'ed up */
        mpc = find_mpc_by_lec(dev);
        if (mpc == NULL)
            break;
        if (mpc->mpoad_vcc != NULL)
            start_mpc(mpc, dev);
        break;
    case NETDEV_DOWN:
        /* the dev was ifconfig'ed down */
        /* this means that the flow of packets from the
         * upper layer stops
         */
        mpc = find_mpc_by_lec(dev);
        if (mpc == NULL)
            break;
        if (mpc->mpoad_vcc != NULL)
            stop_mpc(mpc);
        break;
    case NETDEV_REBOOT:
    case NETDEV_CHANGE:
    case NETDEV_CHANGEMTU:
    case NETDEV_CHANGEADDR:
    case NETDEV_GOING_DOWN:
        break;
    default:
        break;
    }

    return NOTIFY_DONE;
}

/*
 * Functions which are called after a message is received from mpcd.
 * Msg is reused on purpose.
 */


static void MPOA_trigger_rcvd(struct k_message *msg, struct mpoa_client *mpc)
{
    __be32 dst_ip = msg->content.in_info.in_dst_ip;
    in_cache_entry *entry;

    entry = mpc->in_ops->get(dst_ip, mpc);
    if (entry == NULL) {
        entry = mpc->in_ops->add_entry(dst_ip, mpc);
        entry->entry_state = INGRESS_RESOLVING;
        msg->type = SND_MPOA_RES_RQST;
        msg->content.in_info = entry->ctrl_info;
        msg_to_mpoad(msg, mpc);
        do_gettimeofday(&(entry->reply_wait));
        mpc->in_ops->put(entry);
        return;
    }

    if (entry->entry_state == INGRESS_INVALID) {
        entry->entry_state = INGRESS_RESOLVING;
        msg->type = SND_MPOA_RES_RQST;
        msg->content.in_info = entry->ctrl_info;
        msg_to_mpoad(msg, mpc);
        do_gettimeofday(&(entry->reply_wait));
        mpc->in_ops->put(entry);
        return;
    }

    pr_info("(%s) entry already in resolving state\n",
        (mpc->dev) ? mpc->dev->name : "<unknown>");
    mpc->in_ops->put(entry);
}

/*
 * Things get complicated because we have to check if there's an egress
 * shortcut with suitable traffic parameters we could use.
 */
static void check_qos_and_open_shortcut(struct k_message *msg,
                    struct mpoa_client *client,
                    in_cache_entry *entry)
{
    __be32 dst_ip = msg->content.in_info.in_dst_ip;
    struct atm_mpoa_qos *qos = atm_mpoa_search_qos(dst_ip);
    eg_cache_entry *eg_entry = client->eg_ops->get_by_src_ip(dst_ip, client);

    if (eg_entry && eg_entry->shortcut) {
        if (eg_entry->shortcut->qos.txtp.traffic_class &
            msg->qos.txtp.traffic_class &
            (qos ? qos->qos.txtp.traffic_class : ATM_UBR | ATM_CBR)) {
            if (eg_entry->shortcut->qos.txtp.traffic_class == ATM_UBR)
                entry->shortcut = eg_entry->shortcut;
            else if (eg_entry->shortcut->qos.txtp.max_pcr > 0)
                entry->shortcut = eg_entry->shortcut;
        }
        if (entry->shortcut) {
            dprintk("(%s) using egress SVC to reach %pI4\n",
                client->dev->name, &dst_ip);
            client->eg_ops->put(eg_entry);
            return;
        }
    }
    if (eg_entry != NULL)
        client->eg_ops->put(eg_entry);

    /* No luck in the egress cache we must open an ingress SVC */
    msg->type = OPEN_INGRESS_SVC;
    if (qos &&
        (qos->qos.txtp.traffic_class == msg->qos.txtp.traffic_class)) {
        msg->qos = qos->qos;
        pr_info("(%s) trying to get a CBR shortcut\n",
            client->dev->name);
    } else
        memset(&msg->qos, 0, sizeof(struct atm_qos));
    msg_to_mpoad(msg, client);
}

static void MPOA_res_reply_rcvd(struct k_message *msg, struct mpoa_client *mpc)
{
    __be32 dst_ip = msg->content.in_info.in_dst_ip;
    in_cache_entry *entry = mpc->in_ops->get(dst_ip, mpc);

    dprintk("(%s) ip %pI4\n",
        mpc->dev->name, &dst_ip);
    ddprintk("(%s) entry = %p",
         mpc->dev->name, entry);
    if (entry == NULL) {
        pr_info("(%s) ARGH, received res. reply for an entry that doesn't exist.\n",
            mpc->dev->name);
        return;
    }
    ddprintk_cont(" entry_state = %d ", entry->entry_state);

    if (entry->entry_state == INGRESS_RESOLVED) {
        pr_info("(%s) RESOLVED entry!\n", mpc->dev->name);
        mpc->in_ops->put(entry);
        return;
    }

    entry->ctrl_info = msg->content.in_info;
    do_gettimeofday(&(entry->tv));
    do_gettimeofday(&(entry->reply_wait)); /* Used in refreshing func from now on */
    entry->refresh_time = 0;
    ddprintk_cont("entry->shortcut = %p\n", entry->shortcut);

    if (entry->entry_state == INGRESS_RESOLVING &&
        entry->shortcut != NULL) {
        entry->entry_state = INGRESS_RESOLVED;
        mpc->in_ops->put(entry);
        return; /* Shortcut already open... */
    }

    if (entry->shortcut != NULL) {
        pr_info("(%s) entry->shortcut != NULL, impossible!\n",
            mpc->dev->name);
        mpc->in_ops->put(entry);
        return;
    }

    check_qos_and_open_shortcut(msg, mpc, entry);
    entry->entry_state = INGRESS_RESOLVED;
    mpc->in_ops->put(entry);

    return;

}

static void ingress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc)
{
    __be32 dst_ip = msg->content.in_info.in_dst_ip;
    __be32 mask = msg->ip_mask;
    in_cache_entry *entry = mpc->in_ops->get_with_mask(dst_ip, mpc, mask);

    if (entry == NULL) {
        pr_info("(%s) purge for a non-existing entry, ip = %pI4\n",
            mpc->dev->name, &dst_ip);
        return;
    }

    do {
        dprintk("(%s) removing an ingress entry, ip = %pI4\n",
            mpc->dev->name, &dst_ip);
        write_lock_bh(&mpc->ingress_lock);
        mpc->in_ops->remove_entry(entry, mpc);
        write_unlock_bh(&mpc->ingress_lock);
        mpc->in_ops->put(entry);
        entry = mpc->in_ops->get_with_mask(dst_ip, mpc, mask);
    } while (entry != NULL);
}

static void egress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc)
{
    __be32 cache_id = msg->content.eg_info.cache_id;
    eg_cache_entry *entry = mpc->eg_ops->get_by_cache_id(cache_id, mpc);

    if (entry == NULL) {
        dprintk("(%s) purge for a non-existing entry\n",
            mpc->dev->name);
        return;
    }

    write_lock_irq(&mpc->egress_lock);
    mpc->eg_ops->remove_entry(entry, mpc);
    write_unlock_irq(&mpc->egress_lock);

    mpc->eg_ops->put(entry);
}

static void purge_egress_shortcut(struct atm_vcc *vcc, eg_cache_entry *entry)
{
    struct sock *sk;
    struct k_message *purge_msg;
    struct sk_buff *skb;

    dprintk("entering\n");
    if (vcc == NULL) {
        pr_info("vcc == NULL\n");
        return;
    }

    skb = alloc_skb(sizeof(struct k_message), GFP_ATOMIC);
    if (skb == NULL) {
        pr_info("out of memory\n");
        return;
    }

    skb_put(skb, sizeof(struct k_message));
    memset(skb->data, 0, sizeof(struct k_message));
    purge_msg = (struct k_message *)skb->data;
    purge_msg->type = DATA_PLANE_PURGE;
    if (entry != NULL)
        purge_msg->content.eg_info = entry->ctrl_info;

    atm_force_charge(vcc, skb->truesize);

    sk = sk_atm(vcc);
    skb_queue_tail(&sk->sk_receive_queue, skb);
    sk->sk_data_ready(sk, skb->len);
    dprintk("exiting\n");
}

/*
 * Our MPS died. Tell our daemon to send NHRP data plane purge to each
 * of the egress shortcuts we have.
 */
static void mps_death(struct k_message *msg, struct mpoa_client *mpc)
{
    eg_cache_entry *entry;

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

    if (memcmp(msg->MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN)) {
        pr_info("(%s) wrong MPS\n", mpc->dev->name);
        return;
    }

    /* FIXME: This knows too much of the cache structure */
    read_lock_irq(&mpc->egress_lock);
    entry = mpc->eg_cache;
    while (entry != NULL) {
        purge_egress_shortcut(entry->shortcut, entry);
        entry = entry->next;
    }
    read_unlock_irq(&mpc->egress_lock);

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

static void MPOA_cache_impos_rcvd(struct k_message *msg,
                  struct mpoa_client *mpc)
{
    uint16_t holding_time;
    eg_cache_entry *entry = mpc->eg_ops->get_by_cache_id(msg->content.eg_info.cache_id, mpc);

    holding_time = msg->content.eg_info.holding_time;
    dprintk("(%s) entry = %p, holding_time = %u\n",
        mpc->dev->name, entry, holding_time);
    if (entry == NULL && holding_time) {
        entry = mpc->eg_ops->add_entry(msg, mpc);
        mpc->eg_ops->put(entry);
        return;
    }
    if (holding_time) {
        mpc->eg_ops->update(entry, holding_time);
        return;
    }

    write_lock_irq(&mpc->egress_lock);
    mpc->eg_ops->remove_entry(entry, mpc);
    write_unlock_irq(&mpc->egress_lock);

    mpc->eg_ops->put(entry);
}

static void set_mpc_ctrl_addr_rcvd(struct k_message *mesg,
                   struct mpoa_client *mpc)
{
    struct lec_priv *priv;
    int i, retval ;

    uint8_t tlv[4 + 1 + 1 + 1 + ATM_ESA_LEN];

    tlv[0] = 00; tlv[1] = 0xa0; tlv[2] = 0x3e; tlv[3] = 0x2a; /* type  */
    tlv[4] = 1 + 1 + ATM_ESA_LEN;  /* length                           */
    tlv[5] = 0x02;                 /* MPOA client                      */
    tlv[6] = 0x00;                 /* number of MPS MAC addresses      */

    memcpy(&tlv[7], mesg->MPS_ctrl, ATM_ESA_LEN); /* MPC ctrl ATM addr */
    memcpy(mpc->our_ctrl_addr, mesg->MPS_ctrl, ATM_ESA_LEN);

    dprintk("(%s) setting MPC ctrl ATM address to",
        mpc->dev ? mpc->dev->name : "<unknown>");
    for (i = 7; i < sizeof(tlv); i++)
        dprintk_cont(" %02x", tlv[i]);
    dprintk_cont("\n");

    if (mpc->dev) {
        priv = netdev_priv(mpc->dev);
        retval = priv->lane2_ops->associate_req(mpc->dev,
                            mpc->dev->dev_addr,
                            tlv, sizeof(tlv));
        if (retval == 0)
            pr_info("(%s) MPOA device type TLV association failed\n",
                mpc->dev->name);
        retval = priv->lane2_ops->resolve(mpc->dev, NULL, 1, NULL, NULL);
        if (retval < 0)
            pr_info("(%s) targetless LE_ARP request failed\n",
                mpc->dev->name);
    }
}

static void set_mps_mac_addr_rcvd(struct k_message *msg,
                  struct mpoa_client *client)
{

    if (client->number_of_mps_macs)
        kfree(client->mps_macs);
    client->number_of_mps_macs = 0;
    client->mps_macs = kmemdup(msg->MPS_ctrl, ETH_ALEN, GFP_KERNEL);
    if (client->mps_macs == NULL) {
        pr_info("out of memory\n");
        return;
    }
    client->number_of_mps_macs = 1;
}

/*
 * purge egress cache and tell daemon to 'action' (DIE, RELOAD)
 */
static void clean_up(struct k_message *msg, struct mpoa_client *mpc, int action)
{

    eg_cache_entry *entry;
    msg->type = SND_EGRESS_PURGE;


    /* FIXME: This knows too much of the cache structure */
    read_lock_irq(&mpc->egress_lock);
    entry = mpc->eg_cache;
    while (entry != NULL) {
        msg->content.eg_info = entry->ctrl_info;
        dprintk("cache_id %u\n", entry->ctrl_info.cache_id);
        msg_to_mpoad(msg, mpc);
        entry = entry->next;
    }
    read_unlock_irq(&mpc->egress_lock);

    msg->type = action;
    msg_to_mpoad(msg, mpc);
}

static void mpc_timer_refresh(void)
{
    mpc_timer.expires = jiffies + (MPC_P2 * HZ);
    mpc_timer.data = mpc_timer.expires;
    mpc_timer.function = mpc_cache_check;
    add_timer(&mpc_timer);
}

static void mpc_cache_check(unsigned long checking_time)
{
    struct mpoa_client *mpc = mpcs;
    static unsigned long previous_resolving_check_time;
    static unsigned long previous_refresh_time;

    while (mpc != NULL) {
        mpc->in_ops->clear_count(mpc);
        mpc->eg_ops->clear_expired(mpc);
        if (checking_time - previous_resolving_check_time >
            mpc->parameters.mpc_p4 * HZ) {
            mpc->in_ops->check_resolving(mpc);
            previous_resolving_check_time = checking_time;
        }
        if (checking_time - previous_refresh_time >
            mpc->parameters.mpc_p5 * HZ) {
            mpc->in_ops->refresh(mpc);
            previous_refresh_time = checking_time;
        }
        mpc = mpc->next;
    }
    mpc_timer_refresh();
}

static int atm_mpoa_ioctl(struct socket *sock, unsigned int cmd,
              unsigned long arg)
{
    int err = 0;
    struct atm_vcc *vcc = ATM_SD(sock);

    if (cmd != ATMMPC_CTRL && cmd != ATMMPC_DATA)
        return -ENOIOCTLCMD;

    if (!capable(CAP_NET_ADMIN))
        return -EPERM;

    switch (cmd) {
    case ATMMPC_CTRL:
        err = atm_mpoa_mpoad_attach(vcc, (int)arg);
        if (err >= 0)
            sock->state = SS_CONNECTED;
        break;
    case ATMMPC_DATA:
        err = atm_mpoa_vcc_attach(vcc, (void __user *)arg);
        break;
    default:
        break;
    }
    return err;
}

static struct atm_ioctl atm_ioctl_ops = {
    .owner  = THIS_MODULE,
    .ioctl  = atm_mpoa_ioctl,
};

static __init int atm_mpoa_init(void)
{
    register_atm_ioctl(&atm_ioctl_ops);

    if (mpc_proc_init() != 0)
        pr_info("failed to initialize /proc/mpoa\n");

    pr_info("mpc.c: initialized\n");

    return 0;
}

static void __exit atm_mpoa_cleanup(void)
{
    struct mpoa_client *mpc, *tmp;
    struct atm_mpoa_qos *qos, *nextqos;
    struct lec_priv *priv;

    mpc_proc_clean();

    del_timer(&mpc_timer);
    unregister_netdevice_notifier(&mpoa_notifier);
    deregister_atm_ioctl(&atm_ioctl_ops);

    mpc = mpcs;
    mpcs = NULL;
    while (mpc != NULL) {
        tmp = mpc->next;
        if (mpc->dev != NULL) {
            stop_mpc(mpc);
            priv = netdev_priv(mpc->dev);
            if (priv->lane2_ops != NULL)
                priv->lane2_ops->associate_indicator = NULL;
        }
        ddprintk("about to clear caches\n");
        mpc->in_ops->destroy_cache(mpc);
        mpc->eg_ops->destroy_cache(mpc);
        ddprintk("caches cleared\n");
        kfree(mpc->mps_macs);
        memset(mpc, 0, sizeof(struct mpoa_client));
        ddprintk("about to kfree %p\n", mpc);
        kfree(mpc);
        ddprintk("next mpc is at %p\n", tmp);
        mpc = tmp;
    }

    qos = qos_head;
    qos_head = NULL;
    while (qos != NULL) {
        nextqos = qos->next;
        dprintk("freeing qos entry %p\n", qos);
        kfree(qos);
        qos = nextqos;
    }
}

module_init(atm_mpoa_init);
module_exit(atm_mpoa_cleanup);

MODULE_LICENSE("GPL");