cfg80211/nl80211: scanning (and mac80211 update to use it)

This patch adds basic scan capability to cfg80211/nl80211 and
changes mac80211 to use it. The BSS list that cfg80211 maintains
is made driver-accessible with a private area in each BSS struct,
but mac80211 doesn't yet use it. That's another large project.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 807 insertions, 0 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
new file mode 100644
index 000000000000..009d12810c55
--- /dev/null
+++ b/net/wireless/scan.c
@@ -0,0 +1,807 @@
+/*
+ * cfg80211 scan result handling
+ *
+ * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/wireless.h>
+#include <linux/nl80211.h>
+#include <linux/etherdevice.h>
+#include <net/arp.h>
+#include <net/cfg80211.h>
+#include <net/iw_handler.h>
+#include "core.h"
+#include "nl80211.h"
+
+#define IEEE80211_SCAN_RESULT_EXPIRE    (10 * HZ)
+
+void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
+{
+        struct net_device *dev;
+#ifdef CONFIG_WIRELESS_EXT
+        union iwreq_data wrqu;
+#endif
+
+        dev = dev_get_by_index(&init_net, request->ifidx);
+        if (!dev)
+                goto out;
+
+        WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
+        wiphy_to_dev(request->wiphy)->scan_req = NULL;
+
+        if (aborted)
+                nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
+        else
+                nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
+
+#ifdef CONFIG_WIRELESS_EXT
+        if (!aborted) {
+                memset(&wrqu, 0, sizeof(wrqu));
+
+                wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
+        }
+#endif
+
+        dev_put(dev);
+
+ out:
+        kfree(request);
+}
+EXPORT_SYMBOL(cfg80211_scan_done);
+
+static void bss_release(struct kref *ref)
+{
+        struct cfg80211_internal_bss *bss;
+
+        bss = container_of(ref, struct cfg80211_internal_bss, ref);
+        kfree(bss);
+}
+
+/* must hold dev->bss_lock! */
+void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
+{
+        struct cfg80211_internal_bss *bss, *tmp;
+        bool expired = false;
+
+        list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
+                if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
+                        continue;
+                list_del(&bss->list);
+                rb_erase(&bss->rbn, &dev->bss_tree);
+                kref_put(&bss->ref, bss_release);
+                expired = true;
+        }
+
+        if (expired)
+                dev->bss_generation++;
+}
+
+static u8 *find_ie(u8 num, u8 *ies, size_t len)
+{
+        while (len > 2 && ies[0] != num) {
+                len -= ies[1] + 2;
+                ies += ies[1] + 2;
+        }
+        if (len < 2)
+                return NULL;
+        if (len < 2 + ies[1])
+                return NULL;
+        return ies;
+}
+
+static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
+{
+        const u8 *ie1 = find_ie(num, ies1, len1);
+        const u8 *ie2 = find_ie(num, ies2, len2);
+        int r;
+
+        if (!ie1 && !ie2)
+                return 0;
+        if (!ie1)
+                return -1;
+
+        r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
+        if (r == 0 && ie1[1] != ie2[1])
+                return ie2[1] - ie1[1];
+        return r;
+}
+
+static bool is_bss(struct cfg80211_bss *a,
+                   const u8 *bssid,
+                   const u8 *ssid, size_t ssid_len)
+{
+        const u8 *ssidie;
+
+        if (compare_ether_addr(a->bssid, bssid))
+                return false;
+
+        ssidie = find_ie(WLAN_EID_SSID,
+                         a->information_elements,
+                         a->len_information_elements);
+        if (!ssidie)
+                return false;
+        if (ssidie[1] != ssid_len)
+                return false;
+        return memcmp(ssidie + 2, ssid, ssid_len) == 0;
+}
+
+static bool is_mesh(struct cfg80211_bss *a,
+                    const u8 *meshid, size_t meshidlen,
+                    const u8 *meshcfg)
+{
+        const u8 *ie;
+
+        if (!is_zero_ether_addr(a->bssid))
+                return false;
+
+        ie = find_ie(WLAN_EID_MESH_ID,
+                     a->information_elements,
+                     a->len_information_elements);
+        if (!ie)
+                return false;
+        if (ie[1] != meshidlen)
+                return false;
+        if (memcmp(ie + 2, meshid, meshidlen))
+                return false;
+
+        ie = find_ie(WLAN_EID_MESH_CONFIG,
+                     a->information_elements,
+                     a->len_information_elements);
+        if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
+                return false;
+
+        /*
+         * Ignore mesh capability (last two bytes of the IE) when
+         * comparing since that may differ between stations taking
+         * part in the same mesh.
+         */
+        return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
+}
+
+static int cmp_bss(struct cfg80211_bss *a,
+                   struct cfg80211_bss *b)
+{
+        int r;
+
+        if (a->channel != b->channel)
+                return b->channel->center_freq - a->channel->center_freq;
+
+        r = memcmp(a->bssid, b->bssid, ETH_ALEN);
+        if (r)
+                return r;
+
+        if (is_zero_ether_addr(a->bssid)) {
+                r = cmp_ies(WLAN_EID_MESH_ID,
+                            a->information_elements,
+                            a->len_information_elements,
+                            b->information_elements,
+                            b->len_information_elements);
+                if (r)
+                        return r;
+                return cmp_ies(WLAN_EID_MESH_CONFIG,
+                               a->information_elements,
+                               a->len_information_elements,
+                               b->information_elements,
+                               b->len_information_elements);
+        }
+
+        return cmp_ies(WLAN_EID_SSID,
+                       a->information_elements,
+                       a->len_information_elements,
+                       b->information_elements,
+                       b->len_information_elements);
+}
+
+struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
+                                      struct ieee80211_channel *channel,
+                                      const u8 *bssid,
+                                      const u8 *ssid, size_t ssid_len)
+{
+        struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
+        struct cfg80211_internal_bss *bss, *res = NULL;
+
+        spin_lock_bh(&dev->bss_lock);
+
+        list_for_each_entry(bss, &dev->bss_list, list) {
+                if (channel && bss->pub.channel != channel)
+                        continue;
+                if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
+                        res = bss;
+                        kref_get(&res->ref);
+                        break;
+                }
+        }
+
+        spin_unlock_bh(&dev->bss_lock);
+        if (!res)
+                return NULL;
+        return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_get_bss);
+
+struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
+                                       struct ieee80211_channel *channel,
+                                       const u8 *meshid, size_t meshidlen,
+                                       const u8 *meshcfg)
+{
+        struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
+        struct cfg80211_internal_bss *bss, *res = NULL;
+
+        spin_lock_bh(&dev->bss_lock);
+
+        list_for_each_entry(bss, &dev->bss_list, list) {
+                if (channel && bss->pub.channel != channel)
+                        continue;
+                if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
+                        res = bss;
+                        kref_get(&res->ref);
+                        break;
+                }
+        }
+
+        spin_unlock_bh(&dev->bss_lock);
+        if (!res)
+                return NULL;
+        return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_get_mesh);
+
+
+static void rb_insert_bss(struct cfg80211_registered_device *dev,
+                          struct cfg80211_internal_bss *bss)
+{
+        struct rb_node **p = &dev->bss_tree.rb_node;
+        struct rb_node *parent = NULL;
+        struct cfg80211_internal_bss *tbss;
+        int cmp;
+
+        while (*p) {
+                parent = *p;
+                tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
+
+                cmp = cmp_bss(&bss->pub, &tbss->pub);
+
+                if (WARN_ON(!cmp)) {
+                        /* will sort of leak this BSS */
+                        return;
+                }
+
+                if (cmp < 0)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+
+        rb_link_node(&bss->rbn, parent, p);
+        rb_insert_color(&bss->rbn, &dev->bss_tree);
+}
+
+static struct cfg80211_internal_bss *
+rb_find_bss(struct cfg80211_registered_device *dev,
+            struct cfg80211_internal_bss *res)
+{
+        struct rb_node *n = dev->bss_tree.rb_node;
+        struct cfg80211_internal_bss *bss;
+        int r;
+
+        while (n) {
+                bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
+                r = cmp_bss(&res->pub, &bss->pub);
+
+                if (r == 0)
+                        return bss;
+                else if (r < 0)
+                        n = n->rb_left;
+                else
+                        n = n->rb_right;
+        }
+
+        return NULL;
+}
+
+static struct cfg80211_internal_bss *
+cfg80211_bss_update(struct cfg80211_registered_device *dev,
+                    struct cfg80211_internal_bss *res,
+                    bool overwrite)
+{
+        struct cfg80211_internal_bss *found = NULL;
+        const u8 *meshid, *meshcfg;
+
+        /*
+         * The reference to "res" is donated to this function.
+         */
+
+        if (WARN_ON(!res->pub.channel)) {
+                kref_put(&res->ref, bss_release);
+                return NULL;
+        }
+
+        res->ts = jiffies;
+
+        if (is_zero_ether_addr(res->pub.bssid)) {
+                /* must be mesh, verify */
+                meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
+                                 res->pub.len_information_elements);
+                meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
+                                  res->pub.information_elements,
+                                  res->pub.len_information_elements);
+                if (!meshid || !meshcfg ||
+                    meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
+                        /* bogus mesh */
+                        kref_put(&res->ref, bss_release);
+                        return NULL;
+                }
+        }
+
+        spin_lock_bh(&dev->bss_lock);
+
+        found = rb_find_bss(dev, res);
+
+        if (found && overwrite) {
+                list_replace(&found->list, &res->list);
+                rb_replace_node(&found->rbn, &res->rbn,
+                                &dev->bss_tree);
+                kref_put(&found->ref, bss_release);
+                found = res;
+        } else if (found) {
+                kref_get(&found->ref);
+                found->pub.beacon_interval = res->pub.beacon_interval;
+                found->pub.tsf = res->pub.tsf;
+                found->pub.signal = res->pub.signal;
+                found->pub.signal_type = res->pub.signal_type;
+                found->pub.capability = res->pub.capability;
+                found->ts = res->ts;
+                kref_put(&res->ref, bss_release);
+        } else {
+                /* this "consumes" the reference */
+                list_add_tail(&res->list, &dev->bss_list);
+                rb_insert_bss(dev, res);
+                found = res;
+        }
+
+        dev->bss_generation++;
+        spin_unlock_bh(&dev->bss_lock);
+
+        kref_get(&found->ref);
+        return found;
+}
+
+struct cfg80211_bss *
+cfg80211_inform_bss_frame(struct wiphy *wiphy,
+                          struct ieee80211_channel *channel,
+                          struct ieee80211_mgmt *mgmt, size_t len,
+                          s32 signal, enum cfg80211_signal_type sigtype,
+                          gfp_t gfp)
+{
+        struct cfg80211_internal_bss *res;
+        size_t ielen = len - offsetof(struct ieee80211_mgmt,
+                                      u.probe_resp.variable);
+        bool overwrite;
+        size_t privsz = wiphy->bss_priv_size;
+
+        if (WARN_ON(sigtype == NL80211_BSS_SIGNAL_UNSPEC &&
+                    (signal < 0 || signal > 100)))
+                return NULL;
+
+        if (WARN_ON(!mgmt || !wiphy ||
+                    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
+                return NULL;
+
+        res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
+        if (!res)
+                return NULL;
+
+        memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
+        res->pub.channel = channel;
+        res->pub.signal_type = sigtype;
+        res->pub.signal = signal;
+        res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
+        res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
+        res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
+        /* point to after the private area */
+        res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
+        memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
+        res->pub.len_information_elements = ielen;
+
+        kref_init(&res->ref);
+
+        overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
+
+        res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
+        if (!res)
+                return NULL;
+
+        /* cfg80211_bss_update gives us a referenced result */
+        return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_inform_bss_frame);
+
+void cfg80211_put_bss(struct cfg80211_bss *pub)
+{
+        struct cfg80211_internal_bss *bss;
+
+        if (!pub)
+                return;
+
+        bss = container_of(pub, struct cfg80211_internal_bss, pub);
+        kref_put(&bss->ref, bss_release);
+}
+EXPORT_SYMBOL(cfg80211_put_bss);
+
+#ifdef CONFIG_WIRELESS_EXT
+int cfg80211_wext_siwscan(struct net_device *dev,
+                          struct iw_request_info *info,
+                          union iwreq_data *wrqu, char *extra)
+{
+        struct cfg80211_registered_device *rdev;
+        struct wiphy *wiphy;
+        struct iw_scan_req *wreq = NULL;
+        struct cfg80211_scan_request *creq;
+        int i, err, n_channels = 0;
+        enum ieee80211_band band;
+
+        if (!netif_running(dev))
+                return -ENETDOWN;
+
+        rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
+
+        if (IS_ERR(rdev))
+                return PTR_ERR(rdev);
+
+        if (rdev->scan_req) {
+                err = -EBUSY;
+                goto out;
+        }
+
+        wiphy = &rdev->wiphy;
+
+        for (band = 0; band < IEEE80211_NUM_BANDS; band++)
+                if (wiphy->bands[band])
+                        n_channels += wiphy->bands[band]->n_channels;
+
+        creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
+                       n_channels * sizeof(void *),
+                       GFP_ATOMIC);
+        if (!creq) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        creq->wiphy = wiphy;
+        creq->ifidx = dev->ifindex;
+        creq->ssids = (void *)(creq + 1);
+        creq->channels = (void *)(creq->ssids + 1);
+        creq->n_channels = n_channels;
+        creq->n_ssids = 1;
+
+        /* all channels */
+        i = 0;
+        for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+                int j;
+                if (!wiphy->bands[band])
+                        continue;
+                for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
+                        creq->channels[i] = &wiphy->bands[band]->channels[j];
+                        i++;
+                }
+        }
+
+        /* translate scan request */
+        if (wrqu->data.length == sizeof(struct iw_scan_req)) {
+                wreq = (struct iw_scan_req *)extra;
+
+                if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
+                        if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
+                                return -EINVAL;
+                        memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
+                        creq->ssids[0].ssid_len = wreq->essid_len;
+                }
+                if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
+                        creq->n_ssids = 0;
+        }
+
+        rdev->scan_req = creq;
+        err = rdev->ops->scan(wiphy, dev, creq);
+        if (err) {
+                rdev->scan_req = NULL;
+                kfree(creq);
+        }
+ out:
+        cfg80211_put_dev(rdev);
+        return err;
+}
+EXPORT_SYMBOL(cfg80211_wext_siwscan);
+
+static void ieee80211_scan_add_ies(struct iw_request_info *info,
+                                   struct cfg80211_bss *bss,
+                                   char **current_ev, char *end_buf)
+{
+        u8 *pos, *end, *next;
+        struct iw_event iwe;
+
+        if (!bss->information_elements ||
+            !bss->len_information_elements)
+                return;
+
+        /*
+         * If needed, fragment the IEs buffer (at IE boundaries) into short
+         * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
+         */
+        pos = bss->information_elements;
+        end = pos + bss->len_information_elements;
+
+        while (end - pos > IW_GENERIC_IE_MAX) {
+                next = pos + 2 + pos[1];
+                while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
+                        next = next + 2 + next[1];
+
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = IWEVGENIE;
+                iwe.u.data.length = next - pos;
+                *current_ev = iwe_stream_add_point(info, *current_ev,
+                                                   end_buf, &iwe, pos);
+
+                pos = next;
+        }
+
+        if (end > pos) {
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = IWEVGENIE;
+                iwe.u.data.length = end - pos;
+                *current_ev = iwe_stream_add_point(info, *current_ev,
+                                                   end_buf, &iwe, pos);
+        }
+}
+
+
+static char *
+ieee80211_bss(struct iw_request_info *info,
+                      struct cfg80211_internal_bss *bss,
+                      char *current_ev, char *end_buf)
+{
+        struct iw_event iwe;
+        u8 *buf, *cfg, *p;
+        u8 *ie = bss->pub.information_elements;
+        int rem = bss->pub.len_information_elements, i;
+        bool ismesh = false;
+
+        memset(&iwe, 0, sizeof(iwe));
+        iwe.cmd = SIOCGIWAP;
+        iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
+        memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
+        current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
+                                          IW_EV_ADDR_LEN);
+
+        memset(&iwe, 0, sizeof(iwe));
+        iwe.cmd = SIOCGIWFREQ;
+        iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
+        iwe.u.freq.e = 0;
+        current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
+                                          IW_EV_FREQ_LEN);
+
+        memset(&iwe, 0, sizeof(iwe));
+        iwe.cmd = SIOCGIWFREQ;
+        iwe.u.freq.m = bss->pub.channel->center_freq;
+        iwe.u.freq.e = 6;
+        current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
+                                          IW_EV_FREQ_LEN);
+
+        if (bss->pub.signal_type != CFG80211_SIGNAL_TYPE_NONE) {
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = IWEVQUAL;
+                iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
+                                     IW_QUAL_NOISE_INVALID |
+                                     IW_QUAL_QUAL_INVALID;
+                switch (bss->pub.signal_type) {
+                case CFG80211_SIGNAL_TYPE_MBM:
+                        iwe.u.qual.level = bss->pub.signal / 100;
+                        iwe.u.qual.updated |= IW_QUAL_DBM;
+                        break;
+                case CFG80211_SIGNAL_TYPE_UNSPEC:
+                        iwe.u.qual.level = bss->pub.signal;
+                        break;
+                default:
+                        /* not reached */
+                        break;
+                }
+                current_ev = iwe_stream_add_event(info, current_ev, end_buf,
+                                                  &iwe, IW_EV_QUAL_LEN);
+        }
+
+        memset(&iwe, 0, sizeof(iwe));
+        iwe.cmd = SIOCGIWENCODE;
+        if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
+                iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
+        else
+                iwe.u.data.flags = IW_ENCODE_DISABLED;
+        iwe.u.data.length = 0;
+        current_ev = iwe_stream_add_point(info, current_ev, end_buf,
+                                          &iwe, "");
+
+        while (rem >= 2) {
+                /* invalid data */
+                if (ie[1] > rem - 2)
+                        break;
+
+                switch (ie[0]) {
+                case WLAN_EID_SSID:
+                        memset(&iwe, 0, sizeof(iwe));
+                        iwe.cmd = SIOCGIWESSID;
+                        iwe.u.data.length = ie[1];
+                        iwe.u.data.flags = 1;
+                        current_ev = iwe_stream_add_point(info, current_ev, end_buf,
+                                                          &iwe, ie + 2);
+                        break;
+                case WLAN_EID_MESH_ID:
+                        memset(&iwe, 0, sizeof(iwe));
+                        iwe.cmd = SIOCGIWESSID;
+                        iwe.u.data.length = ie[1];
+                        iwe.u.data.flags = 1;
+                        current_ev = iwe_stream_add_point(info, current_ev, end_buf,
+                                                          &iwe, ie + 2);
+                        break;
+                case WLAN_EID_MESH_CONFIG:
+                        ismesh = true;
+                        if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
+                                break;
+                        buf = kmalloc(50, GFP_ATOMIC);
+                        if (!buf)
+                                break;
+                        cfg = ie + 2;
+                        memset(&iwe, 0, sizeof(iwe));
+                        iwe.cmd = IWEVCUSTOM;
+                        sprintf(buf, "Mesh network (version %d)", cfg[0]);
+                        iwe.u.data.length = strlen(buf);
+                        current_ev = iwe_stream_add_point(info, current_ev,
+                                                          end_buf,
+                                                          &iwe, buf);
+                        sprintf(buf, "Path Selection Protocol ID: "
+                                "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
+                                                        cfg[4]);
+                        iwe.u.data.length = strlen(buf);
+                        current_ev = iwe_stream_add_point(info, current_ev,
+                                                          end_buf,
+                                                          &iwe, buf);
+                        sprintf(buf, "Path Selection Metric ID: "
+                                "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
+                                                        cfg[8]);
+                        iwe.u.data.length = strlen(buf);
+                        current_ev = iwe_stream_add_point(info, current_ev,
+                                                          end_buf,
+                                                          &iwe, buf);
+                        sprintf(buf, "Congestion Control Mode ID: "
+                                "0x%02X%02X%02X%02X", cfg[9], cfg[10],
+                                                        cfg[11], cfg[12]);
+                        iwe.u.data.length = strlen(buf);
+                        current_ev = iwe_stream_add_point(info, current_ev,
+                                                          end_buf,
+                                                          &iwe, buf);
+                        sprintf(buf, "Channel Precedence: "
+                                "0x%02X%02X%02X%02X", cfg[13], cfg[14],
+                                                        cfg[15], cfg[16]);
+                        iwe.u.data.length = strlen(buf);
+                        current_ev = iwe_stream_add_point(info, current_ev,
+                                                          end_buf,
+                                                          &iwe, buf);
+                        kfree(buf);
+                        break;
+                case WLAN_EID_SUPP_RATES:
+                case WLAN_EID_EXT_SUPP_RATES:
+                        /* display all supported rates in readable format */
+                        p = current_ev + iwe_stream_lcp_len(info);
+
+                        memset(&iwe, 0, sizeof(iwe));
+                        iwe.cmd = SIOCGIWRATE;
+                        /* Those two flags are ignored... */
+                        iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
+
+                        for (i = 0; i < ie[1]; i++) {
+                                iwe.u.bitrate.value =
+                                        ((ie[i + 2] & 0x7f) * 500000);
+                                p = iwe_stream_add_value(info, current_ev, p,
+                                                end_buf, &iwe, IW_EV_PARAM_LEN);
+                        }
+                        current_ev = p;
+                        break;
+                }
+                rem -= ie[1] + 2;
+                ie += ie[1] + 2;
+        }
+
+        if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
+            || ismesh) {
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = SIOCGIWMODE;
+                if (ismesh)
+                        iwe.u.mode = IW_MODE_MESH;
+                else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
+                        iwe.u.mode = IW_MODE_MASTER;
+                else
+                        iwe.u.mode = IW_MODE_ADHOC;
+                current_ev = iwe_stream_add_event(info, current_ev, end_buf,
+                                                  &iwe, IW_EV_UINT_LEN);
+        }
+
+        buf = kmalloc(30, GFP_ATOMIC);
+        if (buf) {
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = IWEVCUSTOM;
+                sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
+                iwe.u.data.length = strlen(buf);
+                current_ev = iwe_stream_add_point(info, current_ev, end_buf,
+                                                  &iwe, buf);
+                memset(&iwe, 0, sizeof(iwe));
+                iwe.cmd = IWEVCUSTOM;
+                sprintf(buf, " Last beacon: %dms ago",
+                        jiffies_to_msecs(jiffies - bss->ts));
+                iwe.u.data.length = strlen(buf);
+                current_ev = iwe_stream_add_point(info, current_ev,
+                                                  end_buf, &iwe, buf);
+                kfree(buf);
+        }
+
+        ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
+
+        return current_ev;
+}
+
+
+static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
+                                  struct iw_request_info *info,
+                                  char *buf, size_t len)
+{
+        char *current_ev = buf;
+        char *end_buf = buf + len;
+        struct cfg80211_internal_bss *bss;
+
+        spin_lock_bh(&dev->bss_lock);
+        cfg80211_bss_expire(dev);
+
+        list_for_each_entry(bss, &dev->bss_list, list) {
+                if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
+                        spin_unlock_bh(&dev->bss_lock);
+                        return -E2BIG;
+                }
+                current_ev = ieee80211_bss(info, bss,
+                                                   current_ev, end_buf);
+        }
+        spin_unlock_bh(&dev->bss_lock);
+        return current_ev - buf;
+}
+
+
+int cfg80211_wext_giwscan(struct net_device *dev,
+                          struct iw_request_info *info,
+                          struct iw_point *data, char *extra)
+{
+        struct cfg80211_registered_device *rdev;
+        int res;
+
+        if (!netif_running(dev))
+                return -ENETDOWN;
+
+        rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
+
+        if (IS_ERR(rdev))
+                return PTR_ERR(rdev);
+
+        if (rdev->scan_req) {
+                res = -EAGAIN;
+                goto out;
+        }
+
+        res = ieee80211_scan_results(rdev, info, extra, data->length);
+        data->length = 0;
+        if (res >= 0) {
+                data->length = res;
+                res = 0;
+        }
+
+ out:
+        cfg80211_put_dev(rdev);
+        return res;
+}
+EXPORT_SYMBOL(cfg80211_wext_giwscan);
+#endif