p80211netdev.c

Go to the documentation of this file.

/* src/p80211/p80211knetdev.c
*
* Linux Kernel net device interface
*
* Copyright (C) 1999 AbsoluteValue Systems, Inc.  All Rights Reserved.
* --------------------------------------------------------------------
*
* linux-wlan
*
*   The contents of this file are subject to the Mozilla Public
*   License Version 1.1 (the "License"); you may not use this file
*   except in compliance with the License. You may obtain a copy of
*   the License at http://www.mozilla.org/MPL/
*
*   Software distributed under the License is distributed on an "AS
*   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
*   implied. See the License for the specific language governing
*   rights and limitations under the License.
*
*   Alternatively, the contents of this file may be used under the
*   terms of the GNU Public License version 2 (the "GPL"), in which
*   case the provisions of the GPL are applicable instead of the
*   above.  If you wish to allow the use of your version of this file
*   only under the terms of the GPL and not to allow others to use
*   your version of this file under the MPL, indicate your decision
*   by deleting the provisions above and replace them with the notice
*   and other provisions required by the GPL.  If you do not delete
*   the provisions above, a recipient may use your version of this
*   file under either the MPL or the GPL.
*
* --------------------------------------------------------------------
*
* Inquiries regarding the linux-wlan Open Source project can be
* made directly to:
*
* AbsoluteValue Systems Inc.
* [email protected]
* http://www.linux-wlan.com
*
* --------------------------------------------------------------------
*
* Portions of the development of this software were funded by
* Intersil Corporation as part of PRISM(R) chipset product development.
*
* --------------------------------------------------------------------
*
* The functions required for a Linux network device are defined here.
*
* --------------------------------------------------------------------
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/kmod.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/sockios.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/byteorder/generic.h>
#include <linux/bitops.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>

#ifdef SIOCETHTOOL
#include <linux/ethtool.h>
#endif

#include <net/iw_handler.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>

#include "p80211types.h"
#include "p80211hdr.h"
#include "p80211conv.h"
#include "p80211mgmt.h"
#include "p80211msg.h"
#include "p80211netdev.h"
#include "p80211ioctl.h"
#include "p80211req.h"
#include "p80211metastruct.h"
#include "p80211metadef.h"

#include "cfg80211.c"

/* Support functions */
static void p80211netdev_rx_bh(unsigned long arg);

/* netdevice method functions */
static int p80211knetdev_init(netdevice_t *netdev);
static struct net_device_stats *p80211knetdev_get_stats(netdevice_t *netdev);
static int p80211knetdev_open(netdevice_t *netdev);
static int p80211knetdev_stop(netdevice_t *netdev);
static int p80211knetdev_hard_start_xmit(struct sk_buff *skb,
                     netdevice_t *netdev);
static void p80211knetdev_set_multicast_list(netdevice_t *dev);
static int p80211knetdev_do_ioctl(netdevice_t *dev, struct ifreq *ifr,
                  int cmd);
static int p80211knetdev_set_mac_address(netdevice_t *dev, void *addr);
static void p80211knetdev_tx_timeout(netdevice_t *netdev);
static int p80211_rx_typedrop(wlandevice_t *wlandev, u16 fc);

int wlan_watchdog = 5000;
module_param(wlan_watchdog, int, 0644);
MODULE_PARM_DESC(wlan_watchdog, "transmit timeout in milliseconds");

int wlan_wext_write = 1;
module_param(wlan_wext_write, int, 0644);
MODULE_PARM_DESC(wlan_wext_write, "enable write wireless extensions");

/*----------------------------------------------------------------
* p80211knetdev_init
*
* Init method for a Linux netdevice.  Called in response to
* register_netdev.
*
* Arguments:
*   none
*
* Returns:
*   nothing
----------------------------------------------------------------*/
static int p80211knetdev_init(netdevice_t *netdev)
{
    /* Called in response to register_netdev */
    /* This is usually the probe function, but the probe has */
    /* already been done by the MSD and the create_kdev */
    /* function.  All we do here is return success */
    return 0;
}

/*----------------------------------------------------------------
* p80211knetdev_get_stats
*
* Statistics retrieval for linux netdevices.  Here we're reporting
* the Linux i/f level statistics.  Hence, for the primary numbers,
* we don't want to report the numbers from the MIB.  Eventually,
* it might be useful to collect some of the error counters though.
*
* Arguments:
*   netdev      Linux netdevice
*
* Returns:
*   the address of the statistics structure
----------------------------------------------------------------*/
static struct net_device_stats *p80211knetdev_get_stats(netdevice_t *netdev)
{
    wlandevice_t *wlandev = netdev->ml_priv;

    /* TODO: review the MIB stats for items that correspond to
       linux stats */

    return &(wlandev->linux_stats);
}

/*----------------------------------------------------------------
* p80211knetdev_open
*
* Linux netdevice open method.  Following a successful call here,
* the device is supposed to be ready for tx and rx.  In our
* situation that may not be entirely true due to the state of the
* MAC below.
*
* Arguments:
*   netdev      Linux network device structure
*
* Returns:
*   zero on success, non-zero otherwise
----------------------------------------------------------------*/
static int p80211knetdev_open(netdevice_t *netdev)
{
    int result = 0;     /* success */
    wlandevice_t *wlandev = netdev->ml_priv;

    /* Check to make sure the MSD is running */
    if (wlandev->msdstate != WLAN_MSD_RUNNING)
        return -ENODEV;

    /* Tell the MSD to open */
    if (wlandev->open != NULL) {
        result = wlandev->open(wlandev);
        if (result == 0) {
            netif_start_queue(wlandev->netdev);
            wlandev->state = WLAN_DEVICE_OPEN;
        }
    } else {
        result = -EAGAIN;
    }

    return result;
}

/*----------------------------------------------------------------
* p80211knetdev_stop
*
* Linux netdevice stop (close) method.  Following this call,
* no frames should go up or down through this interface.
*
* Arguments:
*   netdev      Linux network device structure
*
* Returns:
*   zero on success, non-zero otherwise
----------------------------------------------------------------*/
static int p80211knetdev_stop(netdevice_t *netdev)
{
    int result = 0;
    wlandevice_t *wlandev = netdev->ml_priv;

    if (wlandev->close != NULL)
        result = wlandev->close(wlandev);

    netif_stop_queue(wlandev->netdev);
    wlandev->state = WLAN_DEVICE_CLOSED;

    return result;
}

/*----------------------------------------------------------------
* p80211netdev_rx
*
* Frame receive function called by the mac specific driver.
*
* Arguments:
*   wlandev     WLAN network device structure
*   skb     skbuff containing a full 802.11 frame.
* Returns:
*   nothing
* Side effects:
*
----------------------------------------------------------------*/
void p80211netdev_rx(wlandevice_t *wlandev, struct sk_buff *skb)
{
    /* Enqueue for post-irq processing */
    skb_queue_tail(&wlandev->nsd_rxq, skb);
    tasklet_schedule(&wlandev->rx_bh);
}

/*----------------------------------------------------------------
* p80211netdev_rx_bh
*
* Deferred processing of all received frames.
*
* Arguments:
*   wlandev     WLAN network device structure
*   skb     skbuff containing a full 802.11 frame.
* Returns:
*   nothing
* Side effects:
*
----------------------------------------------------------------*/
static void p80211netdev_rx_bh(unsigned long arg)
{
    wlandevice_t *wlandev = (wlandevice_t *) arg;
    struct sk_buff *skb = NULL;
    netdevice_t *dev = wlandev->netdev;
    struct p80211_hdr_a3 *hdr;
    u16 fc;

    /* Let's empty our our queue */
    while ((skb = skb_dequeue(&wlandev->nsd_rxq))) {
        if (wlandev->state == WLAN_DEVICE_OPEN) {

            if (dev->type != ARPHRD_ETHER) {
                /* RAW frame; we shouldn't convert it */
                /* XXX Append the Prism Header here instead. */

                /* set up various data fields */
                skb->dev = dev;
                skb_reset_mac_header(skb);
                skb->ip_summed = CHECKSUM_NONE;
                skb->pkt_type = PACKET_OTHERHOST;
                skb->protocol = htons(ETH_P_80211_RAW);
                dev->last_rx = jiffies;

                wlandev->linux_stats.rx_packets++;
                wlandev->linux_stats.rx_bytes += skb->len;
                netif_rx_ni(skb);
                continue;
            } else {
                hdr = (struct p80211_hdr_a3 *) skb->data;
                fc = le16_to_cpu(hdr->fc);
                if (p80211_rx_typedrop(wlandev, fc)) {
                    dev_kfree_skb(skb);
                    continue;
                }

                /* perform mcast filtering */
                if (wlandev->netdev->flags & IFF_ALLMULTI) {
                    /* allow my local address through */
                    if (memcmp
                        (hdr->a1, wlandev->netdev->dev_addr,
                         ETH_ALEN) != 0) {
                        /* but reject anything else that
                           isn't multicast */
                        if (!(hdr->a1[0] & 0x01)) {
                            dev_kfree_skb(skb);
                            continue;
                        }
                    }
                }

                if (skb_p80211_to_ether
                    (wlandev, wlandev->ethconv, skb) == 0) {
                    skb->dev->last_rx = jiffies;
                    wlandev->linux_stats.rx_packets++;
                    wlandev->linux_stats.rx_bytes +=
                        skb->len;
                    netif_rx_ni(skb);
                    continue;
                }
                pr_debug("p80211_to_ether failed.\n");
            }
        }
        dev_kfree_skb(skb);
    }
}

/*----------------------------------------------------------------
* p80211knetdev_hard_start_xmit
*
* Linux netdevice method for transmitting a frame.
*
* Arguments:
*   skb Linux sk_buff containing the frame.
*   netdev  Linux netdevice.
*
* Side effects:
*   If the lower layers report that buffers are full. netdev->tbusy
*   will be set to prevent higher layers from sending more traffic.
*
*   Note: If this function returns non-zero, higher layers retain
*         ownership of the skb.
*
* Returns:
*   zero on success, non-zero on failure.
----------------------------------------------------------------*/
static int p80211knetdev_hard_start_xmit(struct sk_buff *skb,
                     netdevice_t *netdev)
{
    int result = 0;
    int txresult = -1;
    wlandevice_t *wlandev = netdev->ml_priv;
    union p80211_hdr p80211_hdr;
    struct p80211_metawep p80211_wep;

    if (skb == NULL)
        return NETDEV_TX_OK;

    if (wlandev->state != WLAN_DEVICE_OPEN) {
        result = 1;
        goto failed;
    }

    memset(&p80211_hdr, 0, sizeof(union p80211_hdr));
    memset(&p80211_wep, 0, sizeof(struct p80211_metawep));

    if (netif_queue_stopped(netdev)) {
        pr_debug("called when queue stopped.\n");
        result = 1;
        goto failed;
    }

    netif_stop_queue(netdev);

    /* Check to see that a valid mode is set */
    switch (wlandev->macmode) {
    case WLAN_MACMODE_IBSS_STA:
    case WLAN_MACMODE_ESS_STA:
    case WLAN_MACMODE_ESS_AP:
        break;
    default:
        /* Mode isn't set yet, just drop the frame
         * and return success .
         * TODO: we need a saner way to handle this
         */
        if (skb->protocol != ETH_P_80211_RAW) {
            netif_start_queue(wlandev->netdev);
            printk(KERN_NOTICE
                   "Tx attempt prior to association, frame dropped.\n");
            wlandev->linux_stats.tx_dropped++;
            result = 0;
            goto failed;
        }
        break;
    }

    /* Check for raw transmits */
    if (skb->protocol == ETH_P_80211_RAW) {
        if (!capable(CAP_NET_ADMIN)) {
            result = 1;
            goto failed;
        }
        /* move the header over */
        memcpy(&p80211_hdr, skb->data, sizeof(union p80211_hdr));
        skb_pull(skb, sizeof(union p80211_hdr));
    } else {
        if (skb_ether_to_p80211
            (wlandev, wlandev->ethconv, skb, &p80211_hdr,
             &p80211_wep) != 0) {
            /* convert failed */
            pr_debug("ether_to_80211(%d) failed.\n",
                 wlandev->ethconv);
            result = 1;
            goto failed;
        }
    }
    if (wlandev->txframe == NULL) {
        result = 1;
        goto failed;
    }

    netdev->trans_start = jiffies;

    wlandev->linux_stats.tx_packets++;
    /* count only the packet payload */
    wlandev->linux_stats.tx_bytes += skb->len;

    txresult = wlandev->txframe(wlandev, skb, &p80211_hdr, &p80211_wep);

    if (txresult == 0) {
        /* success and more buf */
        /* avail, re: hw_txdata */
        netif_wake_queue(wlandev->netdev);
        result = NETDEV_TX_OK;
    } else if (txresult == 1) {
        /* success, no more avail */
        pr_debug("txframe success, no more bufs\n");
        /* netdev->tbusy = 1;  don't set here, irqhdlr */
        /*   may have already cleared it */
        result = NETDEV_TX_OK;
    } else if (txresult == 2) {
        /* alloc failure, drop frame */
        pr_debug("txframe returned alloc_fail\n");
        result = NETDEV_TX_BUSY;
    } else {
        /* buffer full or queue busy, drop frame. */
        pr_debug("txframe returned full or busy\n");
        result = NETDEV_TX_BUSY;
    }

failed:
    /* Free up the WEP buffer if it's not the same as the skb */
    if ((p80211_wep.data) && (p80211_wep.data != skb->data))
        kzfree(p80211_wep.data);

    /* we always free the skb here, never in a lower level. */
    if (!result)
        dev_kfree_skb(skb);

    return result;
}

/*----------------------------------------------------------------
* p80211knetdev_set_multicast_list
*
* Called from higher layers whenever there's a need to set/clear
* promiscuous mode or rewrite the multicast list.
*
* Arguments:
*   none
*
* Returns:
*   nothing
----------------------------------------------------------------*/
static void p80211knetdev_set_multicast_list(netdevice_t *dev)
{
    wlandevice_t *wlandev = dev->ml_priv;

    /* TODO:  real multicast support as well */

    if (wlandev->set_multicast_list)
        wlandev->set_multicast_list(wlandev, dev);

}

#ifdef SIOCETHTOOL

static int p80211netdev_ethtool(wlandevice_t *wlandev, void __user *useraddr)
{
    u32 ethcmd;
    struct ethtool_drvinfo info;
    struct ethtool_value edata;

    memset(&info, 0, sizeof(info));
    memset(&edata, 0, sizeof(edata));

    if (copy_from_user(&ethcmd, useraddr, sizeof(ethcmd)))
        return -EFAULT;

    switch (ethcmd) {
    case ETHTOOL_GDRVINFO:
        info.cmd = ethcmd;
        snprintf(info.driver, sizeof(info.driver), "p80211_%s",
             wlandev->nsdname);
        snprintf(info.version, sizeof(info.version), "%s",
             WLAN_RELEASE);

        if (copy_to_user(useraddr, &info, sizeof(info)))
            return -EFAULT;
        return 0;
#ifdef ETHTOOL_GLINK
    case ETHTOOL_GLINK:
        edata.cmd = ethcmd;

        if (wlandev->linkstatus &&
            (wlandev->macmode != WLAN_MACMODE_NONE)) {
            edata.data = 1;
        } else {
            edata.data = 0;
        }

        if (copy_to_user(useraddr, &edata, sizeof(edata)))
            return -EFAULT;
        return 0;
#endif
    }

    return -EOPNOTSUPP;
}

#endif

/*----------------------------------------------------------------
* p80211knetdev_do_ioctl
*
* Handle an ioctl call on one of our devices.  Everything Linux
* ioctl specific is done here.  Then we pass the contents of the
* ifr->data to the request message handler.
*
* Arguments:
*   dev Linux kernel netdevice
*   ifr Our private ioctl request structure, typed for the
*       generic struct ifreq so we can use ptr to func
*       w/o cast.
*
* Returns:
*   zero on success, a negative errno on failure.  Possible values:
*       -ENETDOWN Device isn't up.
*       -EBUSY  cmd already in progress
*       -ETIME  p80211 cmd timed out (MSD may have its own timers)
*       -EFAULT memory fault copying msg from user buffer
*       -ENOMEM unable to allocate kernel msg buffer
*       -ENOSYS bad magic, it the cmd really for us?
*       -EintR  sleeping on cmd, awakened by signal, cmd cancelled.
*
* Call Context:
*   Process thread (ioctl caller).  TODO: SMP support may require
*   locks.
----------------------------------------------------------------*/
static int p80211knetdev_do_ioctl(netdevice_t *dev, struct ifreq *ifr, int cmd)
{
    int result = 0;
    struct p80211ioctl_req *req = (struct p80211ioctl_req *) ifr;
    wlandevice_t *wlandev = dev->ml_priv;
    u8 *msgbuf;

    pr_debug("rx'd ioctl, cmd=%d, len=%d\n", cmd, req->len);

#ifdef SIOCETHTOOL
    if (cmd == SIOCETHTOOL) {
        result =
            p80211netdev_ethtool(wlandev, (void __user *)ifr->ifr_data);
        goto bail;
    }
#endif

    /* Test the magic, assume ifr is good if it's there */
    if (req->magic != P80211_IOCTL_MAGIC) {
        result = -ENOSYS;
        goto bail;
    }

    if (cmd == P80211_IFTEST) {
        result = 0;
        goto bail;
    } else if (cmd != P80211_IFREQ) {
        result = -ENOSYS;
        goto bail;
    }

    /* Allocate a buf of size req->len */
    msgbuf = kmalloc(req->len, GFP_KERNEL);
    if (msgbuf) {
        if (copy_from_user(msgbuf, (void __user *)req->data, req->len))
            result = -EFAULT;
        else
            result = p80211req_dorequest(wlandev, msgbuf);

        if (result == 0) {
            if (copy_to_user
                ((void __user *)req->data, msgbuf, req->len)) {
                result = -EFAULT;
            }
        }
        kfree(msgbuf);
    } else {
        result = -ENOMEM;
    }
bail:
    /* If allocate,copyfrom or copyto fails, return errno */
    return result;
}

/*----------------------------------------------------------------
* p80211knetdev_set_mac_address
*
* Handles the ioctl for changing the MACAddress of a netdevice
*
* references: linux/netdevice.h and drivers/net/net_init.c
*
* NOTE: [MSM] We only prevent address changes when the netdev is
* up.  We don't control anything based on dot11 state.  If the
* address is changed on a STA that's currently associated, you
* will probably lose the ability to send and receive data frames.
* Just be aware.  Therefore, this should usually only be done
* prior to scan/join/auth/assoc.
*
* Arguments:
*   dev netdevice struct
*   addr    the new MACAddress (a struct)
*
* Returns:
*   zero on success, a negative errno on failure.  Possible values:
*       -EBUSY  device is bussy (cmd not possible)
*       -and errors returned by: p80211req_dorequest(..)
*
* by: Collin R. Mulliner <[email protected]>
----------------------------------------------------------------*/
static int p80211knetdev_set_mac_address(netdevice_t *dev, void *addr)
{
    struct sockaddr *new_addr = addr;
    struct p80211msg_dot11req_mibset dot11req;
    p80211item_unk392_t *mibattr;
    p80211item_pstr6_t *macaddr;
    p80211item_uint32_t *resultcode;
    int result;

    /* If we're running, we don't allow MAC address changes */
    if (netif_running(dev))
        return -EBUSY;

    /* Set up some convenience pointers. */
    mibattr = &dot11req.mibattribute;
    macaddr = (p80211item_pstr6_t *) &mibattr->data;
    resultcode = &dot11req.resultcode;

    /* Set up a dot11req_mibset */
    memset(&dot11req, 0, sizeof(struct p80211msg_dot11req_mibset));
    dot11req.msgcode = DIDmsg_dot11req_mibset;
    dot11req.msglen = sizeof(struct p80211msg_dot11req_mibset);
    memcpy(dot11req.devname,
           ((wlandevice_t *) dev->ml_priv)->name, WLAN_DEVNAMELEN_MAX - 1);

    /* Set up the mibattribute argument */
    mibattr->did = DIDmsg_dot11req_mibset_mibattribute;
    mibattr->status = P80211ENUM_msgitem_status_data_ok;
    mibattr->len = sizeof(mibattr->data);

    macaddr->did = DIDmib_dot11mac_dot11OperationTable_dot11MACAddress;
    macaddr->status = P80211ENUM_msgitem_status_data_ok;
    macaddr->len = sizeof(macaddr->data);
    macaddr->data.len = ETH_ALEN;
    memcpy(&macaddr->data.data, new_addr->sa_data, ETH_ALEN);

    /* Set up the resultcode argument */
    resultcode->did = DIDmsg_dot11req_mibset_resultcode;
    resultcode->status = P80211ENUM_msgitem_status_no_value;
    resultcode->len = sizeof(resultcode->data);
    resultcode->data = 0;

    /* now fire the request */
    result = p80211req_dorequest(dev->ml_priv, (u8 *) &dot11req);

    /* If the request wasn't successful, report an error and don't
     * change the netdev address
     */
    if (result != 0 || resultcode->data != P80211ENUM_resultcode_success) {
        printk(KERN_ERR
               "Low-level driver failed dot11req_mibset(dot11MACAddress).\n");
        result = -EADDRNOTAVAIL;
    } else {
        /* everything's ok, change the addr in netdev */
        memcpy(dev->dev_addr, new_addr->sa_data, dev->addr_len);
    }

    return result;
}

static int wlan_change_mtu(netdevice_t *dev, int new_mtu)
{
    /* 2312 is max 802.11 payload, 20 is overhead, (ether + llc +snap)
       and another 8 for wep. */
    if ((new_mtu < 68) || (new_mtu > (2312 - 20 - 8)))
        return -EINVAL;

    dev->mtu = new_mtu;

    return 0;
}

static const struct net_device_ops p80211_netdev_ops = {
    .ndo_init = p80211knetdev_init,
    .ndo_open = p80211knetdev_open,
    .ndo_stop = p80211knetdev_stop,
    .ndo_get_stats = p80211knetdev_get_stats,
    .ndo_start_xmit = p80211knetdev_hard_start_xmit,
    .ndo_set_rx_mode = p80211knetdev_set_multicast_list,
    .ndo_do_ioctl = p80211knetdev_do_ioctl,
    .ndo_set_mac_address = p80211knetdev_set_mac_address,
    .ndo_tx_timeout = p80211knetdev_tx_timeout,
    .ndo_change_mtu = wlan_change_mtu,
    .ndo_validate_addr = eth_validate_addr,
};

/*----------------------------------------------------------------
* wlan_setup
*
* Roughly matches the functionality of ether_setup.  Here
* we set up any members of the wlandevice structure that are common
* to all devices.  Additionally, we allocate a linux 'struct device'
* and perform the same setup as ether_setup.
*
* Note: It's important that the caller have setup the wlandev->name
*   ptr prior to calling this function.
*
* Arguments:
*   wlandev     ptr to the wlandev structure for the
*           interface.
*   physdev     ptr to usb device
* Returns:
*   zero on success, non-zero otherwise.
* Call Context:
*   Should be process thread.  We'll assume it might be
*   interrupt though.  When we add support for statically
*   compiled drivers, this function will be called in the
*   context of the kernel startup code.
----------------------------------------------------------------*/
int wlan_setup(wlandevice_t *wlandev, struct device *physdev)
{
    int result = 0;
    netdevice_t *netdev;
    struct wiphy *wiphy;
    struct wireless_dev *wdev;

    /* Set up the wlandev */
    wlandev->state = WLAN_DEVICE_CLOSED;
    wlandev->ethconv = WLAN_ETHCONV_8021h;
    wlandev->macmode = WLAN_MACMODE_NONE;

    /* Set up the rx queue */
    skb_queue_head_init(&wlandev->nsd_rxq);
    tasklet_init(&wlandev->rx_bh,
             p80211netdev_rx_bh, (unsigned long)wlandev);

    /* Allocate and initialize the wiphy struct */
    wiphy = wlan_create_wiphy(physdev, wlandev);
    if (wiphy == NULL) {
        printk(KERN_ERR "Failed to alloc wiphy.\n");
        return 1;
    }

    /* Allocate and initialize the struct device */
    netdev = alloc_netdev(sizeof(struct wireless_dev), "wlan%d",
                ether_setup);
    if (netdev == NULL) {
        printk(KERN_ERR "Failed to alloc netdev.\n");
        wlan_free_wiphy(wiphy);
        result = 1;
    } else {
        wlandev->netdev = netdev;
        netdev->ml_priv = wlandev;
        netdev->netdev_ops = &p80211_netdev_ops;
        wdev = netdev_priv(netdev);
        wdev->wiphy = wiphy;
        wdev->iftype = NL80211_IFTYPE_STATION;
        netdev->ieee80211_ptr = wdev;

        netif_stop_queue(netdev);
        netif_carrier_off(netdev);
    }

    return result;
}

/*----------------------------------------------------------------
* wlan_unsetup
*
* This function is paired with the wlan_setup routine.  It should
* be called after unregister_wlandev.  Basically, all it does is
* free the 'struct device' that's associated with the wlandev.
* We do it here because the 'struct device' isn't allocated
* explicitly in the driver code, it's done in wlan_setup.  To
* do the free in the driver might seem like 'magic'.
*
* Arguments:
*   wlandev     ptr to the wlandev structure for the
*           interface.
* Call Context:
*   Should be process thread.  We'll assume it might be
*   interrupt though.  When we add support for statically
*   compiled drivers, this function will be called in the
*   context of the kernel startup code.
----------------------------------------------------------------*/
void wlan_unsetup(wlandevice_t *wlandev)
{
    struct wireless_dev *wdev;

    tasklet_kill(&wlandev->rx_bh);

    if (wlandev->netdev) {
        wdev = netdev_priv(wlandev->netdev);
        if (wdev->wiphy)
            wlan_free_wiphy(wdev->wiphy);
        free_netdev(wlandev->netdev);
        wlandev->netdev = NULL;
    }
}

/*----------------------------------------------------------------
* register_wlandev
*
* Roughly matches the functionality of register_netdev.  This function
* is called after the driver has successfully probed and set up the
* resources for the device.  It's now ready to become a named device
* in the Linux system.
*
* First we allocate a name for the device (if not already set), then
* we call the Linux function register_netdevice.
*
* Arguments:
*   wlandev     ptr to the wlandev structure for the
*           interface.
* Returns:
*   zero on success, non-zero otherwise.
* Call Context:
*   Can be either interrupt or not.
----------------------------------------------------------------*/
int register_wlandev(wlandevice_t *wlandev)
{
    return register_netdev(wlandev->netdev);
}

/*----------------------------------------------------------------
* unregister_wlandev
*
* Roughly matches the functionality of unregister_netdev.  This
* function is called to remove a named device from the system.
*
* First we tell linux that the device should no longer exist.
* Then we remove it from the list of known wlan devices.
*
* Arguments:
*   wlandev     ptr to the wlandev structure for the
*           interface.
* Returns:
*   zero on success, non-zero otherwise.
* Call Context:
*   Can be either interrupt or not.
----------------------------------------------------------------*/
int unregister_wlandev(wlandevice_t *wlandev)
{
    struct sk_buff *skb;

    unregister_netdev(wlandev->netdev);

    /* Now to clean out the rx queue */
    while ((skb = skb_dequeue(&wlandev->nsd_rxq)))
        dev_kfree_skb(skb);

    return 0;
}

/*----------------------------------------------------------------
* p80211netdev_hwremoved
*
* Hardware removed notification. This function should be called
* immediately after an MSD has detected that the underlying hardware
* has been yanked out from under us.  The primary things we need
* to do are:
*   - Mark the wlandev
*   - Prevent any further traffic from the knetdev i/f
*   - Prevent any further requests from mgmt i/f
*   - If there are any waitq'd mgmt requests or mgmt-frame exchanges,
*     shut them down.
*   - Call the MSD hwremoved function.
*
* The remainder of the cleanup will be handled by unregister().
* Our primary goal here is to prevent as much tickling of the MSD
* as possible since the MSD is already in a 'wounded' state.
*
* TODO: As new features are added, this function should be
*       updated.
*
* Arguments:
*   wlandev     WLAN network device structure
* Returns:
*   nothing
* Side effects:
*
* Call context:
*   Usually interrupt.
----------------------------------------------------------------*/
void p80211netdev_hwremoved(wlandevice_t *wlandev)
{
    wlandev->hwremoved = 1;
    if (wlandev->state == WLAN_DEVICE_OPEN)
        netif_stop_queue(wlandev->netdev);

    netif_device_detach(wlandev->netdev);
}

/*----------------------------------------------------------------
* p80211_rx_typedrop
*
* Classifies the frame, increments the appropriate counter, and
* returns 0|1|2 indicating whether the driver should handle, ignore, or
* drop the frame
*
* Arguments:
*   wlandev     wlan device structure
*   fc      frame control field
*
* Returns:
*   zero if the frame should be handled by the driver,
*       one if the frame should be ignored
*       anything else means we drop it.
*
* Side effects:
*
* Call context:
*   interrupt
----------------------------------------------------------------*/
static int p80211_rx_typedrop(wlandevice_t *wlandev, u16 fc)
{
    u16 ftype;
    u16 fstype;
    int drop = 0;
    /* Classify frame, increment counter */
    ftype = WLAN_GET_FC_FTYPE(fc);
    fstype = WLAN_GET_FC_FSTYPE(fc);
#if 0
    pr_debug("rx_typedrop : ftype=%d fstype=%d.\n", ftype, fstype);
#endif
    switch (ftype) {
    case WLAN_FTYPE_MGMT:
        if ((wlandev->netdev->flags & IFF_PROMISC) ||
            (wlandev->netdev->flags & IFF_ALLMULTI)) {
            drop = 1;
            break;
        }
        pr_debug("rx'd mgmt:\n");
        wlandev->rx.mgmt++;
        switch (fstype) {
        case WLAN_FSTYPE_ASSOCREQ:
            /* printk("assocreq"); */
            wlandev->rx.assocreq++;
            break;
        case WLAN_FSTYPE_ASSOCRESP:
            /* printk("assocresp"); */
            wlandev->rx.assocresp++;
            break;
        case WLAN_FSTYPE_REASSOCREQ:
            /* printk("reassocreq"); */
            wlandev->rx.reassocreq++;
            break;
        case WLAN_FSTYPE_REASSOCRESP:
            /* printk("reassocresp"); */
            wlandev->rx.reassocresp++;
            break;
        case WLAN_FSTYPE_PROBEREQ:
            /* printk("probereq"); */
            wlandev->rx.probereq++;
            break;
        case WLAN_FSTYPE_PROBERESP:
            /* printk("proberesp"); */
            wlandev->rx.proberesp++;
            break;
        case WLAN_FSTYPE_BEACON:
            /* printk("beacon"); */
            wlandev->rx.beacon++;
            break;
        case WLAN_FSTYPE_ATIM:
            /* printk("atim"); */
            wlandev->rx.atim++;
            break;
        case WLAN_FSTYPE_DISASSOC:
            /* printk("disassoc"); */
            wlandev->rx.disassoc++;
            break;
        case WLAN_FSTYPE_AUTHEN:
            /* printk("authen"); */
            wlandev->rx.authen++;
            break;
        case WLAN_FSTYPE_DEAUTHEN:
            /* printk("deauthen"); */
            wlandev->rx.deauthen++;
            break;
        default:
            /* printk("unknown"); */
            wlandev->rx.mgmt_unknown++;
            break;
        }
        /* printk("\n"); */
        drop = 2;
        break;

    case WLAN_FTYPE_CTL:
        if ((wlandev->netdev->flags & IFF_PROMISC) ||
            (wlandev->netdev->flags & IFF_ALLMULTI)) {
            drop = 1;
            break;
        }
        pr_debug("rx'd ctl:\n");
        wlandev->rx.ctl++;
        switch (fstype) {
        case WLAN_FSTYPE_PSPOLL:
            /* printk("pspoll"); */
            wlandev->rx.pspoll++;
            break;
        case WLAN_FSTYPE_RTS:
            /* printk("rts"); */
            wlandev->rx.rts++;
            break;
        case WLAN_FSTYPE_CTS:
            /* printk("cts"); */
            wlandev->rx.cts++;
            break;
        case WLAN_FSTYPE_ACK:
            /* printk("ack"); */
            wlandev->rx.ack++;
            break;
        case WLAN_FSTYPE_CFEND:
            /* printk("cfend"); */
            wlandev->rx.cfend++;
            break;
        case WLAN_FSTYPE_CFENDCFACK:
            /* printk("cfendcfack"); */
            wlandev->rx.cfendcfack++;
            break;
        default:
            /* printk("unknown"); */
            wlandev->rx.ctl_unknown++;
            break;
        }
        /* printk("\n"); */
        drop = 2;
        break;

    case WLAN_FTYPE_DATA:
        wlandev->rx.data++;
        switch (fstype) {
        case WLAN_FSTYPE_DATAONLY:
            wlandev->rx.dataonly++;
            break;
        case WLAN_FSTYPE_DATA_CFACK:
            wlandev->rx.data_cfack++;
            break;
        case WLAN_FSTYPE_DATA_CFPOLL:
            wlandev->rx.data_cfpoll++;
            break;
        case WLAN_FSTYPE_DATA_CFACK_CFPOLL:
            wlandev->rx.data__cfack_cfpoll++;
            break;
        case WLAN_FSTYPE_NULL:
            pr_debug("rx'd data:null\n");
            wlandev->rx.null++;
            break;
        case WLAN_FSTYPE_CFACK:
            pr_debug("rx'd data:cfack\n");
            wlandev->rx.cfack++;
            break;
        case WLAN_FSTYPE_CFPOLL:
            pr_debug("rx'd data:cfpoll\n");
            wlandev->rx.cfpoll++;
            break;
        case WLAN_FSTYPE_CFACK_CFPOLL:
            pr_debug("rx'd data:cfack_cfpoll\n");
            wlandev->rx.cfack_cfpoll++;
            break;
        default:
            /* printk("unknown"); */
            wlandev->rx.data_unknown++;
            break;
        }

        break;
    }
    return drop;
}

static void p80211knetdev_tx_timeout(netdevice_t *netdev)
{
    wlandevice_t *wlandev = netdev->ml_priv;

    if (wlandev->tx_timeout) {
        wlandev->tx_timeout(wlandev);
    } else {
        printk(KERN_WARNING "Implement tx_timeout for %s\n",
               wlandev->nsdname);
        netif_wake_queue(wlandev->netdev);
    }
}