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 #define MESH_DEFAULT_BEACON_INTERVAL    1000    /* in 1024 us units (=TUs) */
  48 #define MESH_DEFAULT_DTIM_PERIOD        2
  49 #define MESH_DEFAULT_AWAKE_WINDOW       10      /* in 1024 us units (=TUs) */
  50
  51 const struct mesh_config default_mesh_config = {
  52         .dot11MeshRetryTimeout = MESH_RET_T,
  53         .dot11MeshConfirmTimeout = MESH_CONF_T,
  54         .dot11MeshHoldingTimeout = MESH_HOLD_T,
  55         .dot11MeshMaxRetries = MESH_MAX_RETR,
  56         .dot11MeshTTL = MESH_TTL,
  57         .element_ttl = MESH_DEFAULT_ELEMENT_TTL,
  58         .auto_open_plinks = true,
  59         .dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
  60         .dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
  61         .dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
  62         .dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
  63         .dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
  64         .dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
  65         .dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
  66         .path_refresh_time = MESH_PATH_REFRESH_TIME,
  67         .min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
  68         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
  69         .dot11MeshGateAnnouncementProtocol = false,
  70         .dot11MeshForwarding = true,
  71         .rssi_threshold = MESH_RSSI_THRESHOLD,
  72         .ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
  73         .dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
  74         .dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
  75         .dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
  76         .power_mode = NL80211_MESH_POWER_ACTIVE,
  77         .dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
  78 };
  79
  80 const struct mesh_setup default_mesh_setup = {
  81         /* cfg80211_join_mesh() will pick a channel if needed */
  82         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  83         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  84         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  85         .ie = NULL,
  86         .ie_len = 0,
  87         .is_secure = false,
  88         .user_mpm = false,
  89         .beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
  90         .dtim_period = MESH_DEFAULT_DTIM_PERIOD,
  91 };
  92
  93 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  94                          struct net_device *dev,
  95                          struct mesh_setup *setup,
  96                          const struct mesh_config *conf)
  97 {
  98         struct wireless_dev *wdev = dev->ieee80211_ptr;
  99         int err;
 100
 101         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
 102
 103         ASSERT_WDEV_LOCK(wdev);
 104
 105         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 106                 return -EOPNOTSUPP;
 107
 108         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 109               setup->is_secure)
 110                 return -EOPNOTSUPP;
 111
 112         if (wdev->mesh_id_len)
 113                 return -EALREADY;
 114
 115         if (!setup->mesh_id_len)
 116                 return -EINVAL;
 117
 118         if (!rdev->ops->join_mesh)
 119                 return -EOPNOTSUPP;
 120
 121         if (!setup->chandef.chan) {
 122                 /* if no channel explicitly given, use preset channel */
 123                 setup->chandef = wdev->preset_chandef;
 124         }
 125
 126         if (!setup->chandef.chan) {
 127                 /* if we don't have that either, use the first usable channel */
 128                 enum ieee80211_band band;
 129
 130                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 131                         struct ieee80211_supported_band *sband;
 132                         struct ieee80211_channel *chan;
 133                         int i;
 134
 135                         sband = rdev->wiphy.bands[band];
 136                         if (!sband)
 137                                 continue;
 138
 139                         for (i = 0; i < sband->n_channels; i++) {
 140                                 chan = &sband->channels[i];
 141                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 142                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 143                                                    IEEE80211_CHAN_DISABLED |
 144                                                    IEEE80211_CHAN_RADAR))
 145                                         continue;
 146                                 setup->chandef.chan = chan;
 147                                 break;
 148                         }
 149
 150                         if (setup->chandef.chan)
 151                                 break;
 152                 }
 153
 154                 /* no usable channel ... */
 155                 if (!setup->chandef.chan)
 156                         return -EINVAL;
 157
 158                 setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 159                 setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 160         }
 161
 162         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
 163                 return -EINVAL;
 164
 165         err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
 166                                     CHAN_MODE_SHARED);
 167         if (err)
 168                 return err;
 169
 170         err = rdev_join_mesh(rdev, dev, conf, setup);
 171         if (!err) {
 172                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 173                 wdev->mesh_id_len = setup->mesh_id_len;
 174                 wdev->channel = setup->chandef.chan;
 175         }
 176
 177         return err;
 178 }
 179
 180 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 181                        struct net_device *dev,
 182                        struct mesh_setup *setup,
 183                        const struct mesh_config *conf)
 184 {
 185         struct wireless_dev *wdev = dev->ieee80211_ptr;
 186         int err;
 187
 188         mutex_lock(&rdev->devlist_mtx);
 189         wdev_lock(wdev);
 190         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 191         wdev_unlock(wdev);
 192         mutex_unlock(&rdev->devlist_mtx);
 193
 194         return err;
 195 }
 196
 197 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 198                               struct wireless_dev *wdev,
 199                               struct cfg80211_chan_def *chandef)
 200 {
 201         int err;
 202
 203         /*
 204          * Workaround for libertas (only!), it puts the interface
 205          * into mesh mode but doesn't implement join_mesh. Instead,
 206          * it is configured via sysfs and then joins the mesh when
 207          * you set the channel. Note that the libertas mesh isn't
 208          * compatible with 802.11 mesh.
 209          */
 210         if (rdev->ops->libertas_set_mesh_channel) {
 211                 if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 212                         return -EINVAL;
 213
 214                 if (!netif_running(wdev->netdev))
 215                         return -ENETDOWN;
 216
 217                 err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
 218                                             CHAN_MODE_SHARED);
 219                 if (err)
 220                         return err;
 221
 222                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 223                                                      chandef->chan);
 224                 if (!err)
 225                         wdev->channel = chandef->chan;
 226
 227                 return err;
 228         }
 229
 230         if (wdev->mesh_id_len)
 231                 return -EBUSY;
 232
 233         wdev->preset_chandef = *chandef;
 234         return 0;
 235 }
 236
 237 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 238                                  struct net_device *dev)
 239 {
 240         struct wireless_dev *wdev = dev->ieee80211_ptr;
 241         int err;
 242
 243         ASSERT_WDEV_LOCK(wdev);
 244
 245         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 246                 return -EOPNOTSUPP;
 247
 248         if (!rdev->ops->leave_mesh)
 249                 return -EOPNOTSUPP;
 250
 251         if (!wdev->mesh_id_len)
 252                 return -ENOTCONN;
 253
 254         err = rdev_leave_mesh(rdev, dev);
 255         if (!err) {
 256                 wdev->mesh_id_len = 0;
 257                 wdev->channel = NULL;
 258         }
 259
 260         return err;
 261 }
 262
 263 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 264                         struct net_device *dev)
 265 {
 266         struct wireless_dev *wdev = dev->ieee80211_ptr;
 267         int err;
 268
 269         wdev_lock(wdev);
 270         err = __cfg80211_leave_mesh(rdev, dev);
 271         wdev_unlock(wdev);
 272
 273         return err;
 274 }