Merge tag 'io_uring-5.11-2021-01-16' of git://git.kernel.dk/linux-block

[linux/fpc-iii.git] / net / wireless / wext-core.c

/*
 * This file implement the Wireless Extensions core API.
 *
 * Authors :    Jean Tourrilhes - HPL - <jt@hpl.hp.com>
 * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
 * Copyright    2009 Johannes Berg <johannes@sipsolutions.net>
 *
 * (As all part of the Linux kernel, this file is GPL)
 */
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/wireless.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <net/cfg80211.h>
#include <net/iw_handler.h>
#include <net/netlink.h>
#include <net/wext.h>
#include <net/net_namespace.h>

typedef int (*wext_ioctl_func)(struct net_device *, struct iwreq *,
                               unsigned int, struct iw_request_info *,
                               iw_handler);


/*
 * Meta-data about all the standard Wireless Extension request we
 * know about.
 */
static const struct iw_ioctl_description standard_ioctl[] = {
        [IW_IOCTL_IDX(SIOCSIWCOMMIT)] = {
                .header_type    = IW_HEADER_TYPE_NULL,
        },
        [IW_IOCTL_IDX(SIOCGIWNAME)] = {
                .header_type    = IW_HEADER_TYPE_CHAR,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWNWID)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
                .flags          = IW_DESCR_FLAG_EVENT,
        },
        [IW_IOCTL_IDX(SIOCGIWNWID)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWFREQ)] = {
                .header_type    = IW_HEADER_TYPE_FREQ,
                .flags          = IW_DESCR_FLAG_EVENT,
        },
        [IW_IOCTL_IDX(SIOCGIWFREQ)] = {
                .header_type    = IW_HEADER_TYPE_FREQ,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWMODE)] = {
                .header_type    = IW_HEADER_TYPE_UINT,
                .flags          = IW_DESCR_FLAG_EVENT,
        },
        [IW_IOCTL_IDX(SIOCGIWMODE)] = {
                .header_type    = IW_HEADER_TYPE_UINT,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWSENS)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWSENS)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWRANGE)] = {
                .header_type    = IW_HEADER_TYPE_NULL,
        },
        [IW_IOCTL_IDX(SIOCGIWRANGE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = sizeof(struct iw_range),
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWPRIV)] = {
                .header_type    = IW_HEADER_TYPE_NULL,
        },
        [IW_IOCTL_IDX(SIOCGIWPRIV)] = { /* (handled directly by us) */
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct iw_priv_args),
                .max_tokens     = 16,
                .flags          = IW_DESCR_FLAG_NOMAX,
        },
        [IW_IOCTL_IDX(SIOCSIWSTATS)] = {
                .header_type    = IW_HEADER_TYPE_NULL,
        },
        [IW_IOCTL_IDX(SIOCGIWSTATS)] = { /* (handled directly by us) */
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = sizeof(struct iw_statistics),
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWSPY)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct sockaddr),
                .max_tokens     = IW_MAX_SPY,
        },
        [IW_IOCTL_IDX(SIOCGIWSPY)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct sockaddr) +
                                  sizeof(struct iw_quality),
                .max_tokens     = IW_MAX_SPY,
        },
        [IW_IOCTL_IDX(SIOCSIWTHRSPY)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct iw_thrspy),
                .min_tokens     = 1,
                .max_tokens     = 1,
        },
        [IW_IOCTL_IDX(SIOCGIWTHRSPY)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct iw_thrspy),
                .min_tokens     = 1,
                .max_tokens     = 1,
        },
        [IW_IOCTL_IDX(SIOCSIWAP)] = {
                .header_type    = IW_HEADER_TYPE_ADDR,
        },
        [IW_IOCTL_IDX(SIOCGIWAP)] = {
                .header_type    = IW_HEADER_TYPE_ADDR,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWMLME)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .min_tokens     = sizeof(struct iw_mlme),
                .max_tokens     = sizeof(struct iw_mlme),
        },
        [IW_IOCTL_IDX(SIOCGIWAPLIST)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = sizeof(struct sockaddr) +
                                  sizeof(struct iw_quality),
                .max_tokens     = IW_MAX_AP,
                .flags          = IW_DESCR_FLAG_NOMAX,
        },
        [IW_IOCTL_IDX(SIOCSIWSCAN)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .min_tokens     = 0,
                .max_tokens     = sizeof(struct iw_scan_req),
        },
        [IW_IOCTL_IDX(SIOCGIWSCAN)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_SCAN_MAX_DATA,
                .flags          = IW_DESCR_FLAG_NOMAX,
        },
        [IW_IOCTL_IDX(SIOCSIWESSID)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ESSID_MAX_SIZE,
                .flags          = IW_DESCR_FLAG_EVENT,
        },
        [IW_IOCTL_IDX(SIOCGIWESSID)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ESSID_MAX_SIZE,
                .flags          = IW_DESCR_FLAG_DUMP,
        },
        [IW_IOCTL_IDX(SIOCSIWNICKN)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ESSID_MAX_SIZE,
        },
        [IW_IOCTL_IDX(SIOCGIWNICKN)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ESSID_MAX_SIZE,
        },
        [IW_IOCTL_IDX(SIOCSIWRATE)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWRATE)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWRTS)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWRTS)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWFRAG)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWFRAG)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWTXPOW)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWTXPOW)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWRETRY)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWRETRY)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWENCODE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ENCODING_TOKEN_MAX,
                .flags          = IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
        },
        [IW_IOCTL_IDX(SIOCGIWENCODE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_ENCODING_TOKEN_MAX,
                .flags          = IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
        },
        [IW_IOCTL_IDX(SIOCSIWPOWER)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWPOWER)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWGENIE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_GENERIC_IE_MAX,
        },
        [IW_IOCTL_IDX(SIOCGIWGENIE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_GENERIC_IE_MAX,
        },
        [IW_IOCTL_IDX(SIOCSIWAUTH)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCGIWAUTH)] = {
                .header_type    = IW_HEADER_TYPE_PARAM,
        },
        [IW_IOCTL_IDX(SIOCSIWENCODEEXT)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .min_tokens     = sizeof(struct iw_encode_ext),
                .max_tokens     = sizeof(struct iw_encode_ext) +
                                  IW_ENCODING_TOKEN_MAX,
        },
        [IW_IOCTL_IDX(SIOCGIWENCODEEXT)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .min_tokens     = sizeof(struct iw_encode_ext),
                .max_tokens     = sizeof(struct iw_encode_ext) +
                                  IW_ENCODING_TOKEN_MAX,
        },
        [IW_IOCTL_IDX(SIOCSIWPMKSA)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .min_tokens     = sizeof(struct iw_pmksa),
                .max_tokens     = sizeof(struct iw_pmksa),
        },
};
static const unsigned int standard_ioctl_num = ARRAY_SIZE(standard_ioctl);

/*
 * Meta-data about all the additional standard Wireless Extension events
 * we know about.
 */
static const struct iw_ioctl_description standard_event[] = {
        [IW_EVENT_IDX(IWEVTXDROP)] = {
                .header_type    = IW_HEADER_TYPE_ADDR,
        },
        [IW_EVENT_IDX(IWEVQUAL)] = {
                .header_type    = IW_HEADER_TYPE_QUAL,
        },
        [IW_EVENT_IDX(IWEVCUSTOM)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_CUSTOM_MAX,
        },
        [IW_EVENT_IDX(IWEVREGISTERED)] = {
                .header_type    = IW_HEADER_TYPE_ADDR,
        },
        [IW_EVENT_IDX(IWEVEXPIRED)] = {
                .header_type    = IW_HEADER_TYPE_ADDR,
        },
        [IW_EVENT_IDX(IWEVGENIE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_GENERIC_IE_MAX,
        },
        [IW_EVENT_IDX(IWEVMICHAELMICFAILURE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = sizeof(struct iw_michaelmicfailure),
        },
        [IW_EVENT_IDX(IWEVASSOCREQIE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_GENERIC_IE_MAX,
        },
        [IW_EVENT_IDX(IWEVASSOCRESPIE)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = IW_GENERIC_IE_MAX,
        },
        [IW_EVENT_IDX(IWEVPMKIDCAND)] = {
                .header_type    = IW_HEADER_TYPE_POINT,
                .token_size     = 1,
                .max_tokens     = sizeof(struct iw_pmkid_cand),
        },
};
static const unsigned int standard_event_num = ARRAY_SIZE(standard_event);

/* Size (in bytes) of various events */
static const int event_type_size[] = {
        IW_EV_LCP_LEN,                  /* IW_HEADER_TYPE_NULL */
        0,
        IW_EV_CHAR_LEN,                 /* IW_HEADER_TYPE_CHAR */
        0,
        IW_EV_UINT_LEN,                 /* IW_HEADER_TYPE_UINT */
        IW_EV_FREQ_LEN,                 /* IW_HEADER_TYPE_FREQ */
        IW_EV_ADDR_LEN,                 /* IW_HEADER_TYPE_ADDR */
        0,
        IW_EV_POINT_LEN,                /* Without variable payload */
        IW_EV_PARAM_LEN,                /* IW_HEADER_TYPE_PARAM */
        IW_EV_QUAL_LEN,                 /* IW_HEADER_TYPE_QUAL */
};

#ifdef CONFIG_COMPAT
static const int compat_event_type_size[] = {
        IW_EV_COMPAT_LCP_LEN,           /* IW_HEADER_TYPE_NULL */
        0,
        IW_EV_COMPAT_CHAR_LEN,          /* IW_HEADER_TYPE_CHAR */
        0,
        IW_EV_COMPAT_UINT_LEN,          /* IW_HEADER_TYPE_UINT */
        IW_EV_COMPAT_FREQ_LEN,          /* IW_HEADER_TYPE_FREQ */
        IW_EV_COMPAT_ADDR_LEN,          /* IW_HEADER_TYPE_ADDR */
        0,
        IW_EV_COMPAT_POINT_LEN,         /* Without variable payload */
        IW_EV_COMPAT_PARAM_LEN,         /* IW_HEADER_TYPE_PARAM */
        IW_EV_COMPAT_QUAL_LEN,          /* IW_HEADER_TYPE_QUAL */
};
#endif


/* IW event code */

void wireless_nlevent_flush(void)
{
        struct sk_buff *skb;
        struct net *net;

        down_read(&net_rwsem);
        for_each_net(net) {
                while ((skb = skb_dequeue(&net->wext_nlevents)))
                        rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL,
                                    GFP_KERNEL);
        }
        up_read(&net_rwsem);
}
EXPORT_SYMBOL_GPL(wireless_nlevent_flush);

static int wext_netdev_notifier_call(struct notifier_block *nb,
                                     unsigned long state, void *ptr)
{
        /*
         * When a netdev changes state in any way, flush all pending messages
         * to avoid them going out in a strange order, e.g. RTM_NEWLINK after
         * RTM_DELLINK, or with IFF_UP after without IFF_UP during dev_close()
         * or similar - all of which could otherwise happen due to delays from
         * schedule_work().
         */
        wireless_nlevent_flush();

        return NOTIFY_OK;
}

static struct notifier_block wext_netdev_notifier = {
        .notifier_call = wext_netdev_notifier_call,
};

static int __net_init wext_pernet_init(struct net *net)
{
        skb_queue_head_init(&net->wext_nlevents);
        return 0;
}

static void __net_exit wext_pernet_exit(struct net *net)
{
        skb_queue_purge(&net->wext_nlevents);
}

static struct pernet_operations wext_pernet_ops = {
        .init = wext_pernet_init,
        .exit = wext_pernet_exit,
};

static int __init wireless_nlevent_init(void)
{
        int err = register_pernet_subsys(&wext_pernet_ops);

        if (err)
                return err;

        err = register_netdevice_notifier(&wext_netdev_notifier);
        if (err)
                unregister_pernet_subsys(&wext_pernet_ops);
        return err;
}

subsys_initcall(wireless_nlevent_init);

/* Process events generated by the wireless layer or the driver. */
static void wireless_nlevent_process(struct work_struct *work)
{
        wireless_nlevent_flush();
}

static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process);

static struct nlmsghdr *rtnetlink_ifinfo_prep(struct net_device *dev,
                                              struct sk_buff *skb)
{
        struct ifinfomsg *r;
        struct nlmsghdr  *nlh;

        nlh = nlmsg_put(skb, 0, 0, RTM_NEWLINK, sizeof(*r), 0);
        if (!nlh)
                return NULL;

        r = nlmsg_data(nlh);
        r->ifi_family = AF_UNSPEC;
        r->__ifi_pad = 0;
        r->ifi_type = dev->type;
        r->ifi_index = dev->ifindex;
        r->ifi_flags = dev_get_flags(dev);
        r->ifi_change = 0;      /* Wireless changes don't affect those flags */

        if (nla_put_string(skb, IFLA_IFNAME, dev->name))
                goto nla_put_failure;

        return nlh;
 nla_put_failure:
        nlmsg_cancel(skb, nlh);
        return NULL;
}


/*
 * Main event dispatcher. Called from other parts and drivers.
 * Send the event on the appropriate channels.
 * May be called from interrupt context.
 */
void wireless_send_event(struct net_device *    dev,
                         unsigned int           cmd,
                         union iwreq_data *     wrqu,
                         const char *           extra)
{
        const struct iw_ioctl_description *     descr = NULL;
        int extra_len = 0;
        struct iw_event  *event;                /* Mallocated whole event */
        int event_len;                          /* Its size */
        int hdr_len;                            /* Size of the event header */
        int wrqu_off = 0;                       /* Offset in wrqu */
        /* Don't "optimise" the following variable, it will crash */
        unsigned int    cmd_index;              /* *MUST* be unsigned */
        struct sk_buff *skb;
        struct nlmsghdr *nlh;
        struct nlattr *nla;
#ifdef CONFIG_COMPAT
        struct __compat_iw_event *compat_event;
        struct compat_iw_point compat_wrqu;
        struct sk_buff *compskb;
#endif

        /*
         * Nothing in the kernel sends scan events with data, be safe.
         * This is necessary because we cannot fix up scan event data
         * for compat, due to being contained in 'extra', but normally
         * applications are required to retrieve the scan data anyway
         * and no data is included in the event, this codifies that
         * practice.
         */
        if (WARN_ON(cmd == SIOCGIWSCAN && extra))
                extra = NULL;

        /* Get the description of the Event */
        if (cmd <= SIOCIWLAST) {
                cmd_index = IW_IOCTL_IDX(cmd);
                if (cmd_index < standard_ioctl_num)
                        descr = &(standard_ioctl[cmd_index]);
        } else {
                cmd_index = IW_EVENT_IDX(cmd);
                if (cmd_index < standard_event_num)
                        descr = &(standard_event[cmd_index]);
        }
        /* Don't accept unknown events */
        if (descr == NULL) {
                /* Note : we don't return an error to the driver, because
                 * the driver would not know what to do about it. It can't
                 * return an error to the user, because the event is not
                 * initiated by a user request.
                 * The best the driver could do is to log an error message.
                 * We will do it ourselves instead...
                 */
                netdev_err(dev, "(WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
                           cmd);
                return;
        }

        /* Check extra parameters and set extra_len */
        if (descr->header_type == IW_HEADER_TYPE_POINT) {
                /* Check if number of token fits within bounds */
                if (wrqu->data.length > descr->max_tokens) {
                        netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too big (%d)\n",
                                   cmd, wrqu->data.length);
                        return;
                }
                if (wrqu->data.length < descr->min_tokens) {
                        netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too small (%d)\n",
                                   cmd, wrqu->data.length);
                        return;
                }
                /* Calculate extra_len - extra is NULL for restricted events */
                if (extra != NULL)
                        extra_len = wrqu->data.length * descr->token_size;
                /* Always at an offset in wrqu */
                wrqu_off = IW_EV_POINT_OFF;
        }

        /* Total length of the event */
        hdr_len = event_type_size[descr->header_type];
        event_len = hdr_len + extra_len;

        /*
         * The problem for 64/32 bit.
         *
         * On 64-bit, a regular event is laid out as follows:
         *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
         *      | event.len | event.cmd |     p a d d i n g     |
         *      | wrqu data ... (with the correct size)         |
         *
         * This padding exists because we manipulate event->u,
         * and 'event' is not packed.
         *
         * An iw_point event is laid out like this instead:
         *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
         *      | event.len | event.cmd |     p a d d i n g     |
         *      | iwpnt.len | iwpnt.flg |     p a d d i n g     |
         *      | extra data  ...
         *
         * The second padding exists because struct iw_point is extended,
         * but this depends on the platform...
         *
         * On 32-bit, all the padding shouldn't be there.
         */

        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!skb)
                return;

        /* Send via the RtNetlink event channel */
        nlh = rtnetlink_ifinfo_prep(dev, skb);
        if (WARN_ON(!nlh)) {
                kfree_skb(skb);
                return;
        }

        /* Add the wireless events in the netlink packet */
        nla = nla_reserve(skb, IFLA_WIRELESS, event_len);
        if (!nla) {
                kfree_skb(skb);
                return;
        }
        event = nla_data(nla);

        /* Fill event - first clear to avoid data leaking */
        memset(event, 0, hdr_len);
        event->len = event_len;
        event->cmd = cmd;
        memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
        if (extra_len)
                memcpy(((char *) event) + hdr_len, extra, extra_len);

        nlmsg_end(skb, nlh);
#ifdef CONFIG_COMPAT
        hdr_len = compat_event_type_size[descr->header_type];
        event_len = hdr_len + extra_len;

        compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!compskb) {
                kfree_skb(skb);
                return;
        }

        /* Send via the RtNetlink event channel */
        nlh = rtnetlink_ifinfo_prep(dev, compskb);
        if (WARN_ON(!nlh)) {
                kfree_skb(skb);
                kfree_skb(compskb);
                return;
        }

        /* Add the wireless events in the netlink packet */
        nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
        if (!nla) {
                kfree_skb(skb);
                kfree_skb(compskb);
                return;
        }
        compat_event = nla_data(nla);

        compat_event->len = event_len;
        compat_event->cmd = cmd;
        if (descr->header_type == IW_HEADER_TYPE_POINT) {
                compat_wrqu.length = wrqu->data.length;
                compat_wrqu.flags = wrqu->data.flags;
                memcpy(&compat_event->pointer,
                        ((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
                        hdr_len - IW_EV_COMPAT_LCP_LEN);
                if (extra_len)
                        memcpy(((char *) compat_event) + hdr_len,
                                extra, extra_len);
        } else {
                /* extra_len must be zero, so no if (extra) needed */
                memcpy(&compat_event->pointer, wrqu,
                        hdr_len - IW_EV_COMPAT_LCP_LEN);
        }

        nlmsg_end(compskb, nlh);

        skb_shinfo(skb)->frag_list = compskb;
#endif
        skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
        schedule_work(&wireless_nlevent_work);
}
EXPORT_SYMBOL(wireless_send_event);



/* IW handlers */

struct iw_statistics *get_wireless_stats(struct net_device *dev)
{
#ifdef CONFIG_WIRELESS_EXT
        if ((dev->wireless_handlers != NULL) &&
           (dev->wireless_handlers->get_wireless_stats != NULL))
                return dev->wireless_handlers->get_wireless_stats(dev);
#endif

#ifdef CONFIG_CFG80211_WEXT
        if (dev->ieee80211_ptr &&
            dev->ieee80211_ptr->wiphy &&
            dev->ieee80211_ptr->wiphy->wext &&
            dev->ieee80211_ptr->wiphy->wext->get_wireless_stats)
                return dev->ieee80211_ptr->wiphy->wext->get_wireless_stats(dev);
#endif

        /* not found */
        return NULL;
}

/* noinline to avoid a bogus warning with -O3 */
static noinline int iw_handler_get_iwstats(struct net_device *  dev,
                                  struct iw_request_info *      info,
                                  union iwreq_data *            wrqu,
                                  char *                        extra)
{
        /* Get stats from the driver */
        struct iw_statistics *stats;

        stats = get_wireless_stats(dev);
        if (stats) {
                /* Copy statistics to extra */
                memcpy(extra, stats, sizeof(struct iw_statistics));
                wrqu->data.length = sizeof(struct iw_statistics);

                /* Check if we need to clear the updated flag */
                if (wrqu->data.flags != 0)
                        stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
                return 0;
        } else
                return -EOPNOTSUPP;
}

static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
{
        /* Don't "optimise" the following variable, it will crash */
        unsigned int    index;          /* *MUST* be unsigned */
        const struct iw_handler_def *handlers = NULL;

#ifdef CONFIG_CFG80211_WEXT
        if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy)
                handlers = dev->ieee80211_ptr->wiphy->wext;
#endif
#ifdef CONFIG_WIRELESS_EXT
        if (dev->wireless_handlers)
                handlers = dev->wireless_handlers;
#endif

        if (!handlers)
                return NULL;

        /* Try as a standard command */
        index = IW_IOCTL_IDX(cmd);
        if (index < handlers->num_standard)
                return handlers->standard[index];

#ifdef CONFIG_WEXT_PRIV
        /* Try as a private command */
        index = cmd - SIOCIWFIRSTPRIV;
        if (index < handlers->num_private)
                return handlers->private[index];
#endif

        /* Not found */
        return NULL;
}

static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
                                   const struct iw_ioctl_description *descr,
                                   iw_handler handler, struct net_device *dev,
                                   struct iw_request_info *info)
{
        int err, extra_size, user_length = 0, essid_compat = 0;
        char *extra;

        /* Calculate space needed by arguments. Always allocate
         * for max space.
         */
        extra_size = descr->max_tokens * descr->token_size;

        /* Check need for ESSID compatibility for WE < 21 */
        switch (cmd) {
        case SIOCSIWESSID:
        case SIOCGIWESSID:
        case SIOCSIWNICKN:
        case SIOCGIWNICKN:
                if (iwp->length == descr->max_tokens + 1)
                        essid_compat = 1;
                else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
                        char essid[IW_ESSID_MAX_SIZE + 1];
                        unsigned int len;
                        len = iwp->length * descr->token_size;

                        if (len > IW_ESSID_MAX_SIZE)
                                return -EFAULT;

                        err = copy_from_user(essid, iwp->pointer, len);
                        if (err)
                                return -EFAULT;

                        if (essid[iwp->length - 1] == '\0')
                                essid_compat = 1;
                }
                break;
        default:
                break;
        }

        iwp->length -= essid_compat;

        /* Check what user space is giving us */
        if (IW_IS_SET(cmd)) {
                /* Check NULL pointer */
                if (!iwp->pointer && iwp->length != 0)
                        return -EFAULT;
                /* Check if number of token fits within bounds */
                if (iwp->length > descr->max_tokens)
                        return -E2BIG;
                if (iwp->length < descr->min_tokens)
                        return -EINVAL;
        } else {
                /* Check NULL pointer */
                if (!iwp->pointer)
                        return -EFAULT;
                /* Save user space buffer size for checking */
                user_length = iwp->length;

                /* Don't check if user_length > max to allow forward
                 * compatibility. The test user_length < min is
                 * implied by the test at the end.
                 */

                /* Support for very large requests */
                if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
                    (user_length > descr->max_tokens)) {
                        /* Allow userspace to GET more than max so
                         * we can support any size GET requests.
                         * There is still a limit : -ENOMEM.
                         */
                        extra_size = user_length * descr->token_size;

                        /* Note : user_length is originally a __u16,
                         * and token_size is controlled by us,
                         * so extra_size won't get negative and
                         * won't overflow...
                         */
                }
        }

        /* kzalloc() ensures NULL-termination for essid_compat. */
        extra = kzalloc(extra_size, GFP_KERNEL);
        if (!extra)
                return -ENOMEM;

        /* If it is a SET, get all the extra data in here */
        if (IW_IS_SET(cmd) && (iwp->length != 0)) {
                if (copy_from_user(extra, iwp->pointer,
                                   iwp->length *
                                   descr->token_size)) {
                        err = -EFAULT;
                        goto out;
                }

                if (cmd == SIOCSIWENCODEEXT) {
                        struct iw_encode_ext *ee = (void *) extra;

                        if (iwp->length < sizeof(*ee) + ee->key_len) {
                                err = -EFAULT;
                                goto out;
                        }
                }
        }

        if (IW_IS_GET(cmd) && !(descr->flags & IW_DESCR_FLAG_NOMAX)) {
                /*
                 * If this is a GET, but not NOMAX, it means that the extra
                 * data is not bounded by userspace, but by max_tokens. Thus
                 * set the length to max_tokens. This matches the extra data
                 * allocation.
                 * The driver should fill it with the number of tokens it
                 * provided, and it may check iwp->length rather than having
                 * knowledge of max_tokens. If the driver doesn't change the
                 * iwp->length, this ioctl just copies back max_token tokens
                 * filled with zeroes. Hopefully the driver isn't claiming
                 * them to be valid data.
                 */
                iwp->length = descr->max_tokens;
        }

        err = handler(dev, info, (union iwreq_data *) iwp, extra);

        iwp->length += essid_compat;

        /* If we have something to return to the user */
        if (!err && IW_IS_GET(cmd)) {
                /* Check if there is enough buffer up there */
                if (user_length < iwp->length) {
                        err = -E2BIG;
                        goto out;
                }

                if (copy_to_user(iwp->pointer, extra,
                                 iwp->length *
                                 descr->token_size)) {
                        err = -EFAULT;
                        goto out;
                }
        }

        /* Generate an event to notify listeners of the change */
        if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
            ((err == 0) || (err == -EIWCOMMIT))) {
                union iwreq_data *data = (union iwreq_data *) iwp;

                if (descr->flags & IW_DESCR_FLAG_RESTRICT)
                        /* If the event is restricted, don't
                         * export the payload.
                         */
                        wireless_send_event(dev, cmd, data, NULL);
                else
                        wireless_send_event(dev, cmd, data, extra);
        }

out:
        kfree(extra);
        return err;
}

/*
 * Call the commit handler in the driver
 * (if exist and if conditions are right)
 *
 * Note : our current commit strategy is currently pretty dumb,
 * but we will be able to improve on that...
 * The goal is to try to agreagate as many changes as possible
 * before doing the commit. Drivers that will define a commit handler
 * are usually those that need a reset after changing parameters, so
 * we want to minimise the number of reset.
 * A cool idea is to use a timer : at each "set" command, we re-set the
 * timer, when the timer eventually fires, we call the driver.
 * Hopefully, more on that later.
 *
 * Also, I'm waiting to see how many people will complain about the
 * netif_running(dev) test. I'm open on that one...
 * Hopefully, the driver will remember to do a commit in "open()" ;-)
 */
int call_commit_handler(struct net_device *dev)
{
#ifdef CONFIG_WIRELESS_EXT
        if ((netif_running(dev)) &&
           (dev->wireless_handlers->standard[0] != NULL))
                /* Call the commit handler on the driver */
                return dev->wireless_handlers->standard[0](dev, NULL,
                                                           NULL, NULL);
        else
                return 0;               /* Command completed successfully */
#else
        /* cfg80211 has no commit */
        return 0;
#endif
}

/*
 * Main IOCTl dispatcher.
 * Check the type of IOCTL and call the appropriate wrapper...
 */
static int wireless_process_ioctl(struct net *net, struct iwreq *iwr,
                                  unsigned int cmd,
                                  struct iw_request_info *info,
                                  wext_ioctl_func standard,
                                  wext_ioctl_func private)
{
        struct net_device *dev;
        iw_handler      handler;

        /* Permissions are already checked in dev_ioctl() before calling us.
         * The copy_to/from_user() of ifr is also dealt with in there */

        /* Make sure the device exist */
        if ((dev = __dev_get_by_name(net, iwr->ifr_name)) == NULL)
                return -ENODEV;

        /* A bunch of special cases, then the generic case...
         * Note that 'cmd' is already filtered in dev_ioctl() with
         * (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
        if (cmd == SIOCGIWSTATS)
                return standard(dev, iwr, cmd, info,
                                &iw_handler_get_iwstats);

#ifdef CONFIG_WEXT_PRIV
        if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
                return standard(dev, iwr, cmd, info,
                                iw_handler_get_private);
#endif

        /* Basic check */
        if (!netif_device_present(dev))
                return -ENODEV;

        /* New driver API : try to find the handler */
        handler = get_handler(dev, cmd);
        if (handler) {
                /* Standard and private are not the same */
                if (cmd < SIOCIWFIRSTPRIV)
                        return standard(dev, iwr, cmd, info, handler);
                else if (private)
                        return private(dev, iwr, cmd, info, handler);
        }
        return -EOPNOTSUPP;
}

/* If command is `set a parameter', or `get the encoding parameters',
 * check if the user has the right to do it.
 */
static int wext_permission_check(unsigned int cmd)
{
        if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE ||
             cmd == SIOCGIWENCODEEXT) &&
            !capable(CAP_NET_ADMIN))
                return -EPERM;

        return 0;
}

/* entry point from dev ioctl */
static int wext_ioctl_dispatch(struct net *net, struct iwreq *iwr,
                               unsigned int cmd, struct iw_request_info *info,
                               wext_ioctl_func standard,
                               wext_ioctl_func private)
{
        int ret = wext_permission_check(cmd);

        if (ret)
                return ret;

        dev_load(net, iwr->ifr_name);
        rtnl_lock();
        ret = wireless_process_ioctl(net, iwr, cmd, info, standard, private);
        rtnl_unlock();

        return ret;
}

/*
 * Wrapper to call a standard Wireless Extension handler.
 * We do various checks and also take care of moving data between
 * user space and kernel space.
 */
static int ioctl_standard_call(struct net_device *      dev,
                               struct iwreq             *iwr,
                               unsigned int             cmd,
                               struct iw_request_info   *info,
                               iw_handler               handler)
{
        const struct iw_ioctl_description *     descr;
        int                                     ret = -EINVAL;

        /* Get the description of the IOCTL */
        if (IW_IOCTL_IDX(cmd) >= standard_ioctl_num)
                return -EOPNOTSUPP;
        descr = &(standard_ioctl[IW_IOCTL_IDX(cmd)]);

        /* Check if we have a pointer to user space data or not */
        if (descr->header_type != IW_HEADER_TYPE_POINT) {

                /* No extra arguments. Trivial to handle */
                ret = handler(dev, info, &(iwr->u), NULL);

                /* Generate an event to notify listeners of the change */
                if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
                   ((ret == 0) || (ret == -EIWCOMMIT)))
                        wireless_send_event(dev, cmd, &(iwr->u), NULL);
        } else {
                ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
                                              handler, dev, info);
        }

        /* Call commit handler if needed and defined */
        if (ret == -EIWCOMMIT)
                ret = call_commit_handler(dev);

        /* Here, we will generate the appropriate event if needed */

        return ret;
}


int wext_handle_ioctl(struct net *net, unsigned int cmd, void __user *arg)
{
        struct iw_request_info info = { .cmd = cmd, .flags = 0 };
        struct iwreq iwr;
        int ret;

        if (copy_from_user(&iwr, arg, sizeof(iwr)))
                return -EFAULT;

        iwr.ifr_name[sizeof(iwr.ifr_name) - 1] = 0;

        ret = wext_ioctl_dispatch(net, &iwr, cmd, &info,
                                  ioctl_standard_call,
                                  ioctl_private_call);
        if (ret >= 0 &&
            IW_IS_GET(cmd) &&
            copy_to_user(arg, &iwr, sizeof(struct iwreq)))
                return -EFAULT;

        return ret;
}

#ifdef CONFIG_COMPAT
static int compat_standard_call(struct net_device       *dev,
                                struct iwreq            *iwr,
                                unsigned int            cmd,
                                struct iw_request_info  *info,
                                iw_handler              handler)
{
        const struct iw_ioctl_description *descr;
        struct compat_iw_point *iwp_compat;
        struct iw_point iwp;
        int err;

        descr = standard_ioctl + IW_IOCTL_IDX(cmd);

        if (descr->header_type != IW_HEADER_TYPE_POINT)
                return ioctl_standard_call(dev, iwr, cmd, info, handler);

        iwp_compat = (struct compat_iw_point *) &iwr->u.data;
        iwp.pointer = compat_ptr(iwp_compat->pointer);
        iwp.length = iwp_compat->length;
        iwp.flags = iwp_compat->flags;

        err = ioctl_standard_iw_point(&iwp, cmd, descr, handler, dev, info);

        iwp_compat->pointer = ptr_to_compat(iwp.pointer);
        iwp_compat->length = iwp.length;
        iwp_compat->flags = iwp.flags;

        return err;
}

int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
                             unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        struct iw_request_info info;
        struct iwreq iwr;
        char *colon;
        int ret;

        if (copy_from_user(&iwr, argp, sizeof(struct iwreq)))
                return -EFAULT;

        iwr.ifr_name[IFNAMSIZ-1] = 0;
        colon = strchr(iwr.ifr_name, ':');
        if (colon)
                *colon = 0;

        info.cmd = cmd;
        info.flags = IW_REQUEST_FLAG_COMPAT;

        ret = wext_ioctl_dispatch(net, &iwr, cmd, &info,
                                  compat_standard_call,
                                  compat_private_call);

        if (ret >= 0 &&
            IW_IS_GET(cmd) &&
            copy_to_user(argp, &iwr, sizeof(struct iwreq)))
                return -EFAULT;

        return ret;
}
#endif

char *iwe_stream_add_event(struct iw_request_info *info, char *stream,
                           char *ends, struct iw_event *iwe, int event_len)
{
        int lcp_len = iwe_stream_lcp_len(info);

        event_len = iwe_stream_event_len_adjust(info, event_len);

        /* Check if it's possible */
        if (likely((stream + event_len) < ends)) {
                iwe->len = event_len;
                /* Beware of alignement issues on 64 bits */
                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
                memcpy(stream + lcp_len, &iwe->u,
                       event_len - lcp_len);
                stream += event_len;
        }

        return stream;
}
EXPORT_SYMBOL(iwe_stream_add_event);

char *iwe_stream_add_point(struct iw_request_info *info, char *stream,
                           char *ends, struct iw_event *iwe, char *extra)
{
        int event_len = iwe_stream_point_len(info) + iwe->u.data.length;
        int point_len = iwe_stream_point_len(info);
        int lcp_len   = iwe_stream_lcp_len(info);

        /* Check if it's possible */
        if (likely((stream + event_len) < ends)) {
                iwe->len = event_len;
                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
                memcpy(stream + lcp_len,
                       ((char *) &iwe->u) + IW_EV_POINT_OFF,
                       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
                if (iwe->u.data.length && extra)
                        memcpy(stream + point_len, extra, iwe->u.data.length);
                stream += event_len;
        }

        return stream;
}
EXPORT_SYMBOL(iwe_stream_add_point);

char *iwe_stream_add_value(struct iw_request_info *info, char *event,
                           char *value, char *ends, struct iw_event *iwe,
                           int event_len)
{
        int lcp_len = iwe_stream_lcp_len(info);

        /* Don't duplicate LCP */
        event_len -= IW_EV_LCP_LEN;

        /* Check if it's possible */
        if (likely((value + event_len) < ends)) {
                /* Add new value */
                memcpy(value, &iwe->u, event_len);
                value += event_len;
                /* Patch LCP */
                iwe->len = value - event;
                memcpy(event, (char *) iwe, lcp_len);
        }

        return value;
}
EXPORT_SYMBOL(iwe_stream_add_value);