net/wireless/mesh.c

   1 #include <linux/ieee80211.h>
   2 #include <linux/export.h>
   3 #include <net/cfg80211.h>
   4 #include "nl80211.h"
   5 #include "core.h"
   6 #include "rdev-ops.h"
   7
   8 /* Default values, timeouts in ms */
   9 #define MESH_TTL                31
  10 #define MESH_DEFAULT_ELEMENT_TTL 31
  11 #define MESH_MAX_RETR           3
  12 #define MESH_RET_T              100
  13 #define MESH_CONF_T             100
  14 #define MESH_HOLD_T             100
  15
  16 #define MESH_PATH_TIMEOUT       5000
  17 #define MESH_RANN_INTERVAL      5000
  18 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
  19 #define MESH_ROOT_INTERVAL     5000
  20 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
  21
  22 /*
  23  * Minimum interval between two consecutive PREQs originated by the same
  24  * interface
  25  */
  26 #define MESH_PREQ_MIN_INT       10
  27 #define MESH_PERR_MIN_INT       100
  28 #define MESH_DIAM_TRAVERSAL_TIME 50
  29
  30 #define MESH_RSSI_THRESHOLD     0
  31
  32 /*
  33  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  34  * before timing out.  This way it will remain ACTIVE and no data frames
  35  * will be unnecessarily held in the pending queue.
  36  */
  37 #define MESH_PATH_REFRESH_TIME                  1000
  38 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
  39
  40 /* Default maximum number of established plinks per interface */
  41 #define MESH_MAX_ESTAB_PLINKS   32
  42
  43 #define MESH_MAX_PREQ_RETRIES   4
  44
  45 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
  46
  47 const struct mesh_config default_mesh_config = {
  48         .dot11MeshRetryTimeout = MESH_RET_T,
  49         .dot11MeshConfirmTimeout = MESH_CONF_T,
  50         .dot11MeshHoldingTimeout = MESH_HOLD_T,
  51         .dot11MeshMaxRetries = MESH_MAX_RETR,
  52         .dot11MeshTTL = MESH_TTL,
  53         .element_ttl = MESH_DEFAULT_ELEMENT_TTL,
  54         .auto_open_plinks = true,
  55         .dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
  56         .dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
  57         .dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
  58         .dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
  59         .dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
  60         .dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
  61         .dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
  62         .path_refresh_time = MESH_PATH_REFRESH_TIME,
  63         .min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
  64         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
  65         .dot11MeshGateAnnouncementProtocol = false,
  66         .dot11MeshForwarding = true,
  67         .rssi_threshold = MESH_RSSI_THRESHOLD,
  68         .ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
  69         .dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
  70         .dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
  71         .dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
  72 };
  73
  74 const struct mesh_setup default_mesh_setup = {
  75         /* cfg80211_join_mesh() will pick a channel if needed */
  76         .channel = NULL,
  77         .channel_type = NL80211_CHAN_NO_HT,
  78         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  79         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  80         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  81         .ie = NULL,
  82         .ie_len = 0,
  83         .is_secure = false,
  84 };
  85
  86 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  87                          struct net_device *dev,
  88                          struct mesh_setup *setup,
  89                          const struct mesh_config *conf)
  90 {
  91         struct wireless_dev *wdev = dev->ieee80211_ptr;
  92         int err;
  93
  94         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
  95
  96         ASSERT_WDEV_LOCK(wdev);
  97
  98         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
  99                 return -EOPNOTSUPP;
 100
 101         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 102               setup->is_secure)
 103                 return -EOPNOTSUPP;
 104
 105         if (wdev->mesh_id_len)
 106                 return -EALREADY;
 107
 108         if (!setup->mesh_id_len)
 109                 return -EINVAL;
 110
 111         if (!rdev->ops->join_mesh)
 112                 return -EOPNOTSUPP;
 113
 114         if (!setup->channel) {
 115                 /* if no channel explicitly given, use preset channel */
 116                 setup->channel = wdev->preset_chan;
 117                 setup->channel_type = wdev->preset_chantype;
 118         }
 119
 120         if (!setup->channel) {
 121                 /* if we don't have that either, use the first usable channel */
 122                 enum ieee80211_band band;
 123
 124                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 125                         struct ieee80211_supported_band *sband;
 126                         struct ieee80211_channel *chan;
 127                         int i;
 128
 129                         sband = rdev->wiphy.bands[band];
 130                         if (!sband)
 131                                 continue;
 132
 133                         for (i = 0; i < sband->n_channels; i++) {
 134                                 chan = &sband->channels[i];
 135                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 136                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 137                                                    IEEE80211_CHAN_DISABLED |
 138                                                    IEEE80211_CHAN_RADAR))
 139                                         continue;
 140                                 setup->channel = chan;
 141                                 break;
 142                         }
 143
 144                         if (setup->channel)
 145                                 break;
 146                 }
 147
 148                 /* no usable channel ... */
 149                 if (!setup->channel)
 150                         return -EINVAL;
 151
 152                 setup->channel_type = NL80211_CHAN_NO_HT;
 153         }
 154
 155         if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, setup->channel,
 156                                           setup->channel_type))
 157                 return -EINVAL;
 158
 159         err = cfg80211_can_use_chan(rdev, wdev, setup->channel,
 160                                     CHAN_MODE_SHARED);
 161         if (err)
 162                 return err;
 163
 164         err = rdev_join_mesh(rdev, dev, conf, setup);
 165         if (!err) {
 166                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 167                 wdev->mesh_id_len = setup->mesh_id_len;
 168                 wdev->channel = setup->channel;
 169         }
 170
 171         return err;
 172 }
 173
 174 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 175                        struct net_device *dev,
 176                        struct mesh_setup *setup,
 177                        const struct mesh_config *conf)
 178 {
 179         struct wireless_dev *wdev = dev->ieee80211_ptr;
 180         int err;
 181
 182         mutex_lock(&rdev->devlist_mtx);
 183         wdev_lock(wdev);
 184         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 185         wdev_unlock(wdev);
 186         mutex_unlock(&rdev->devlist_mtx);
 187
 188         return err;
 189 }
 190
 191 int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
 192                            struct wireless_dev *wdev, int freq,
 193                            enum nl80211_channel_type channel_type)
 194 {
 195         struct ieee80211_channel *channel;
 196         int err;
 197
 198         channel = rdev_freq_to_chan(rdev, freq, channel_type);
 199         if (!channel || !cfg80211_can_beacon_sec_chan(&rdev->wiphy,
 200                                                       channel,
 201                                                       channel_type)) {
 202                 return -EINVAL;
 203         }
 204
 205         /*
 206          * Workaround for libertas (only!), it puts the interface
 207          * into mesh mode but doesn't implement join_mesh. Instead,
 208          * it is configured via sysfs and then joins the mesh when
 209          * you set the channel. Note that the libertas mesh isn't
 210          * compatible with 802.11 mesh.
 211          */
 212         if (rdev->ops->libertas_set_mesh_channel) {
 213                 if (channel_type != NL80211_CHAN_NO_HT)
 214                         return -EINVAL;
 215
 216                 if (!netif_running(wdev->netdev))
 217                         return -ENETDOWN;
 218
 219                 err = cfg80211_can_use_chan(rdev, wdev, channel,
 220                                             CHAN_MODE_SHARED);
 221                 if (err)
 222                         return err;
 223
 224                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 225                                                      channel);
 226                 if (!err)
 227                         wdev->channel = channel;
 228
 229                 return err;
 230         }
 231
 232         if (wdev->mesh_id_len)
 233                 return -EBUSY;
 234
 235         wdev->preset_chan = channel;
 236         wdev->preset_chantype = channel_type;
 237         return 0;
 238 }
 239
 240 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
 241                 const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
 242 {
 243         struct wireless_dev *wdev = dev->ieee80211_ptr;
 244
 245         trace_cfg80211_notify_new_peer_candidate(dev, macaddr);
 246         if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
 247                 return;
 248
 249         nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
 250                         macaddr, ie, ie_len, gfp);
 251 }
 252 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
 253
 254 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 255                                  struct net_device *dev)
 256 {
 257         struct wireless_dev *wdev = dev->ieee80211_ptr;
 258         int err;
 259
 260         ASSERT_WDEV_LOCK(wdev);
 261
 262         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 263                 return -EOPNOTSUPP;
 264
 265         if (!rdev->ops->leave_mesh)
 266                 return -EOPNOTSUPP;
 267
 268         if (!wdev->mesh_id_len)
 269                 return -ENOTCONN;
 270
 271         err = rdev_leave_mesh(rdev, dev);
 272         if (!err) {
 273                 wdev->mesh_id_len = 0;
 274                 wdev->channel = NULL;
 275         }
 276
 277         return err;
 278 }
 279
 280 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 281                         struct net_device *dev)
 282 {
 283         struct wireless_dev *wdev = dev->ieee80211_ptr;
 284         int err;
 285
 286         wdev_lock(wdev);
 287         err = __cfg80211_leave_mesh(rdev, dev);
 288         wdev_unlock(wdev);
 289
 290         return err;
 291 }