cfg80211/nl80211: add IBSS API

This adds IBSS API along with (preliminary) wext handlers.
The wext handlers can only do IBSS so you need to call them
from your own wext handlers if the mode is IBSS.

The nl80211 API requires
 * an SSID
 * a channel (frequency) for the case that a new IBSS
   has to be created

It optionally supports
 * a flag to fix the channel
 * a fixed BSSID

The cfg80211 code also takes care to leave the IBSS before
the netdev is set down. If wireless extensions are used, it
also caches values when the interface is down and instructs
the driver to join when the interface is set up.

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

1 files changed, 360 insertions, 0 deletions

diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
new file mode 100644
index 000000000000..2bf42fdef3a1
--- /dev/null
+++ b/net/wireless/ibss.c
@@ -0,0 +1,360 @@
+/*
+ * Some IBSS support code for cfg80211.
+ *
+ * Copyright 2009       Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <net/cfg80211.h>
+#include <net/wireless.h>
+#include "nl80211.h"
+
+
+void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid, gfp_t gfp)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct cfg80211_bss *bss;
+#ifdef CONFIG_WIRELESS_EXT
+        union iwreq_data wrqu;
+#endif
+
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return;
+
+        if (WARN_ON(!wdev->ssid_len))
+                return;
+
+        if (memcmp(bssid, wdev->bssid, ETH_ALEN) == 0)
+                return;
+
+        bss = cfg80211_get_bss(wdev->wiphy, NULL, bssid,
+                               wdev->ssid, wdev->ssid_len,
+                               WLAN_CAPABILITY_IBSS, WLAN_CAPABILITY_IBSS);
+
+        if (WARN_ON(!bss))
+                return;
+
+        if (wdev->current_bss) {
+                cfg80211_unhold_bss(wdev->current_bss);
+                cfg80211_put_bss(wdev->current_bss);
+        }
+
+        cfg80211_hold_bss(bss);
+        wdev->current_bss = bss;
+        memcpy(wdev->bssid, bssid, ETH_ALEN);
+
+        nl80211_send_ibss_bssid(wiphy_to_dev(wdev->wiphy), dev, bssid, gfp);
+#ifdef CONFIG_WIRELESS_EXT
+        memset(&wrqu, 0, sizeof(wrqu));
+        memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
+        wireless_send_event(dev, SIOCGIWAP, &wrqu, NULL);
+#endif
+}
+EXPORT_SYMBOL(cfg80211_ibss_joined);
+
+int cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
+                       struct net_device *dev,
+                       struct cfg80211_ibss_params *params)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        int err;
+
+        if (wdev->ssid_len)
+                return -EALREADY;
+
+#ifdef CONFIG_WIRELESS_EXT
+        wdev->wext.channel = params->channel;
+#endif
+        err = rdev->ops->join_ibss(&rdev->wiphy, dev, params);
+
+        if (err)
+                return err;
+
+        memcpy(wdev->ssid, params->ssid, params->ssid_len);
+        wdev->ssid_len = params->ssid_len;
+
+        return 0;
+}
+
+void cfg80211_clear_ibss(struct net_device *dev)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        if (wdev->current_bss) {
+                cfg80211_unhold_bss(wdev->current_bss);
+                cfg80211_put_bss(wdev->current_bss);
+        }
+
+        wdev->current_bss = NULL;
+        wdev->ssid_len = 0;
+        memset(wdev->bssid, 0, ETH_ALEN);
+}
+
+int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
+                        struct net_device *dev)
+{
+        int err;
+
+        err = rdev->ops->leave_ibss(&rdev->wiphy, dev);
+
+        if (err)
+                return err;
+
+        cfg80211_clear_ibss(dev);
+
+        return 0;
+}
+
+#ifdef CONFIG_WIRELESS_EXT
+static int cfg80211_ibss_wext_join(struct cfg80211_registered_device *rdev,
+                                   struct wireless_dev *wdev)
+{
+        enum ieee80211_band band;
+        int i;
+
+        /* try to find an IBSS channel if none requested ... */
+        if (!wdev->wext.channel) {
+                for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+                        struct ieee80211_supported_band *sband;
+                        struct ieee80211_channel *chan;
+
+                        sband = rdev->wiphy.bands[band];
+                        if (!sband)
+                                continue;
+
+                        for (i = 0; i < sband->n_channels; i++) {
+                                chan = &sband->channels[i];
+                                if (chan->flags & IEEE80211_CHAN_NO_IBSS)
+                                        continue;
+                                if (chan->flags & IEEE80211_CHAN_DISABLED)
+                                        continue;
+                                wdev->wext.channel = chan;
+                                break;
+                        }
+
+                        if (wdev->wext.channel)
+                                break;
+                }
+
+                if (!wdev->wext.channel)
+                        return -EINVAL;
+        }
+
+        /* don't join -- SSID is not there */
+        if (!wdev->wext.ssid_len)
+                return 0;
+
+        if (!netif_running(wdev->netdev))
+                return 0;
+
+        return cfg80211_join_ibss(wiphy_to_dev(wdev->wiphy),
+                                  wdev->netdev, &wdev->wext);
+}
+
+int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
+                               struct iw_request_info *info,
+                               struct iw_freq *freq, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct ieee80211_channel *chan;
+        int err;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+                return -EOPNOTSUPP;
+
+        chan = cfg80211_wext_freq(wdev->wiphy, freq);
+        if (chan && IS_ERR(chan))
+                return PTR_ERR(chan);
+
+        if (chan &&
+            (chan->flags & IEEE80211_CHAN_NO_IBSS ||
+             chan->flags & IEEE80211_CHAN_DISABLED))
+                return -EINVAL;
+
+        if (wdev->wext.channel == chan)
+                return 0;
+
+        if (wdev->ssid_len) {
+                err = cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy), dev);
+                if (err)
+                        return err;
+        }
+
+        if (chan) {
+                wdev->wext.channel = chan;
+                wdev->wext.channel_fixed = true;
+        } else {
+                /* cfg80211_ibss_wext_join will pick one if needed */
+                wdev->wext.channel_fixed = false;
+        }
+
+        return cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_siwfreq);
+
+int cfg80211_ibss_wext_giwfreq(struct net_device *dev,
+                               struct iw_request_info *info,
+                               struct iw_freq *freq, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct ieee80211_channel *chan = NULL;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        if (wdev->current_bss)
+                chan = wdev->current_bss->channel;
+        else if (wdev->wext.channel)
+                chan = wdev->wext.channel;
+
+        if (chan) {
+                freq->m = chan->center_freq;
+                freq->e = 6;
+                return 0;
+        }
+
+        /* no channel if not joining */
+        return -EINVAL;
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_giwfreq);
+
+int cfg80211_ibss_wext_siwessid(struct net_device *dev,
+                                struct iw_request_info *info,
+                                struct iw_point *data, char *ssid)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        size_t len = data->length;
+        int err;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+                return -EOPNOTSUPP;
+
+        if (wdev->ssid_len) {
+                err = cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy), dev);
+                if (err)
+                        return err;
+        }
+
+        /* iwconfig uses nul termination in SSID.. */
+        if (len > 0 && ssid[len - 1] == '\0')
+                len--;
+
+        wdev->wext.ssid = wdev->ssid;
+        memcpy(wdev->wext.ssid, ssid, len);
+        wdev->wext.ssid_len = len;
+
+        return cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_siwessid);
+
+int cfg80211_ibss_wext_giwessid(struct net_device *dev,
+                                struct iw_request_info *info,
+                                struct iw_point *data, char *ssid)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        data->flags = 0;
+
+        if (wdev->ssid_len) {
+                data->flags = 1;
+                data->length = wdev->ssid_len;
+                memcpy(ssid, wdev->ssid, data->length);
+        } else if (wdev->wext.ssid) {
+                data->flags = 1;
+                data->length = wdev->wext.ssid_len;
+                memcpy(ssid, wdev->wext.ssid, data->length);
+        }
+
+        return 0;
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_giwessid);
+
+int cfg80211_ibss_wext_siwap(struct net_device *dev,
+                             struct iw_request_info *info,
+                             struct sockaddr *ap_addr, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        u8 *bssid = ap_addr->sa_data;
+        int err;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+                return -EOPNOTSUPP;
+
+        if (ap_addr->sa_family != ARPHRD_ETHER)
+                return -EINVAL;
+
+        /* automatic mode */
+        if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
+                bssid = NULL;
+
+        /* both automatic */
+        if (!bssid && !wdev->wext.bssid)
+                return 0;
+
+        /* fixed already - and no change */
+        if (wdev->wext.bssid && bssid &&
+            compare_ether_addr(bssid, wdev->wext.bssid) == 0)
+                return 0;
+
+        if (wdev->ssid_len) {
+                err = cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy), dev);
+                if (err)
+                        return err;
+        }
+
+        if (bssid) {
+                memcpy(wdev->wext_bssid, bssid, ETH_ALEN);
+                wdev->wext.bssid = wdev->wext_bssid;
+        } else
+                wdev->wext.bssid = NULL;
+
+        return cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_siwap);
+
+int cfg80211_ibss_wext_giwap(struct net_device *dev,
+                             struct iw_request_info *info,
+                             struct sockaddr *ap_addr, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        /* call only for ibss! */
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
+                return -EINVAL;
+
+        ap_addr->sa_family = ARPHRD_ETHER;
+
+        if (wdev->wext.bssid) {
+                memcpy(ap_addr->sa_data, wdev->wext.bssid, ETH_ALEN);
+                return 0;
+        }
+
+        memcpy(ap_addr->sa_data, wdev->bssid, ETH_ALEN);
+        return 0;
+}
+/* temporary symbol - mark GPL - in the future the handler won't be */
+EXPORT_SYMBOL_GPL(cfg80211_ibss_wext_giwap);
+#endif