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         .auth_id = 0, /* open */
  86         .ie = NULL,
  87         .ie_len = 0,
  88         .is_secure = false,
  89         .user_mpm = false,
  90         .beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
  91         .dtim_period = MESH_DEFAULT_DTIM_PERIOD,
  92 };
  93
  94 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  95                          struct net_device *dev,
  96                          struct mesh_setup *setup,
  97                          const struct mesh_config *conf)
  98 {
  99         struct wireless_dev *wdev = dev->ieee80211_ptr;
 100         int err;
 101
 102         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
 103
 104         ASSERT_WDEV_LOCK(wdev);
 105
 106         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 107                 return -EOPNOTSUPP;
 108
 109         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 110               setup->is_secure)
 111                 return -EOPNOTSUPP;
 112
 113         if (wdev->mesh_id_len)
 114                 return -EALREADY;
 115
 116         if (!setup->mesh_id_len)
 117                 return -EINVAL;
 118
 119         if (!rdev->ops->join_mesh)
 120                 return -EOPNOTSUPP;
 121
 122         if (!setup->chandef.chan) {
 123                 /* if no channel explicitly given, use preset channel */
 124                 setup->chandef = wdev->preset_chandef;
 125         }
 126
 127         if (!setup->chandef.chan) {
 128                 /* if we don't have that either, use the first usable channel */
 129                 enum ieee80211_band band;
 130
 131                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 132                         struct ieee80211_supported_band *sband;
 133                         struct ieee80211_channel *chan;
 134                         int i;
 135
 136                         sband = rdev->wiphy.bands[band];
 137                         if (!sband)
 138                                 continue;
 139
 140                         for (i = 0; i < sband->n_channels; i++) {
 141                                 chan = &sband->channels[i];
 142                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 143                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 144                                                    IEEE80211_CHAN_DISABLED |
 145                                                    IEEE80211_CHAN_RADAR))
 146                                         continue;
 147                                 setup->chandef.chan = chan;
 148                                 break;
 149                         }
 150
 151                         if (setup->chandef.chan)
 152                                 break;
 153                 }
 154
 155                 /* no usable channel ... */
 156                 if (!setup->chandef.chan)
 157                         return -EINVAL;
 158
 159                 setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 160                 setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 161         }
 162
 163         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
 164                 return -EINVAL;
 165
 166         err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
 167                                     CHAN_MODE_SHARED);
 168         if (err)
 169                 return err;
 170
 171         err = rdev_join_mesh(rdev, dev, conf, setup);
 172         if (!err) {
 173                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 174                 wdev->mesh_id_len = setup->mesh_id_len;
 175                 wdev->channel = setup->chandef.chan;
 176         }
 177
 178         return err;
 179 }
 180
 181 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 182                        struct net_device *dev,
 183                        struct mesh_setup *setup,
 184                        const struct mesh_config *conf)
 185 {
 186         struct wireless_dev *wdev = dev->ieee80211_ptr;
 187         int err;
 188
 189         wdev_lock(wdev);
 190         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 191         wdev_unlock(wdev);
 192
 193         return err;
 194 }
 195
 196 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 197                               struct wireless_dev *wdev,
 198                               struct cfg80211_chan_def *chandef)
 199 {
 200         int err;
 201
 202         /*
 203          * Workaround for libertas (only!), it puts the interface
 204          * into mesh mode but doesn't implement join_mesh. Instead,
 205          * it is configured via sysfs and then joins the mesh when
 206          * you set the channel. Note that the libertas mesh isn't
 207          * compatible with 802.11 mesh.
 208          */
 209         if (rdev->ops->libertas_set_mesh_channel) {
 210                 if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 211                         return -EINVAL;
 212
 213                 if (!netif_running(wdev->netdev))
 214                         return -ENETDOWN;
 215
 216                 err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
 217                                             CHAN_MODE_SHARED);
 218                 if (err)
 219                         return err;
 220
 221                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 222                                                      chandef->chan);
 223                 if (!err)
 224                         wdev->channel = chandef->chan;
 225
 226                 return err;
 227         }
 228
 229         if (wdev->mesh_id_len)
 230                 return -EBUSY;
 231
 232         wdev->preset_chandef = *chandef;
 233         return 0;
 234 }
 235
 236 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 237                                  struct net_device *dev)
 238 {
 239         struct wireless_dev *wdev = dev->ieee80211_ptr;
 240         int err;
 241
 242         ASSERT_WDEV_LOCK(wdev);
 243
 244         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 245                 return -EOPNOTSUPP;
 246
 247         if (!rdev->ops->leave_mesh)
 248                 return -EOPNOTSUPP;
 249
 250         if (!wdev->mesh_id_len)
 251                 return -ENOTCONN;
 252
 253         err = rdev_leave_mesh(rdev, dev);
 254         if (!err) {
 255                 wdev->mesh_id_len = 0;
 256                 wdev->channel = NULL;
 257         }
 258
 259         return err;
 260 }
 261
 262 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 263                         struct net_device *dev)
 264 {
 265         struct wireless_dev *wdev = dev->ieee80211_ptr;
 266         int err;
 267
 268         wdev_lock(wdev);
 269         err = __cfg80211_leave_mesh(rdev, dev);
 270         wdev_unlock(wdev);
 271
 272         return err;
 273 }