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 #define MESH_DEFAULT_PLINK_TIMEOUT      1800 /* timeout in seconds */
  22
  23 /*
  24  * Minimum interval between two consecutive PREQs originated by the same
  25  * interface
  26  */
  27 #define MESH_PREQ_MIN_INT       10
  28 #define MESH_PERR_MIN_INT       100
  29 #define MESH_DIAM_TRAVERSAL_TIME 50
  30
  31 #define MESH_RSSI_THRESHOLD     0
  32
  33 /*
  34  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  35  * before timing out.  This way it will remain ACTIVE and no data frames
  36  * will be unnecessarily held in the pending queue.
  37  */
  38 #define MESH_PATH_REFRESH_TIME                  1000
  39 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
  40
  41 /* Default maximum number of established plinks per interface */
  42 #define MESH_MAX_ESTAB_PLINKS   32
  43
  44 #define MESH_MAX_PREQ_RETRIES   4
  45
  46 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
  47
  48 #define MESH_DEFAULT_BEACON_INTERVAL    1000    /* in 1024 us units (=TUs) */
  49 #define MESH_DEFAULT_DTIM_PERIOD        2
  50 #define MESH_DEFAULT_AWAKE_WINDOW       10      /* in 1024 us units (=TUs) */
  51
  52 const struct mesh_config default_mesh_config = {
  53         .dot11MeshRetryTimeout = MESH_RET_T,
  54         .dot11MeshConfirmTimeout = MESH_CONF_T,
  55         .dot11MeshHoldingTimeout = MESH_HOLD_T,
  56         .dot11MeshMaxRetries = MESH_MAX_RETR,
  57         .dot11MeshTTL = MESH_TTL,
  58         .element_ttl = MESH_DEFAULT_ELEMENT_TTL,
  59         .auto_open_plinks = true,
  60         .dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
  61         .dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
  62         .dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
  63         .dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
  64         .dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
  65         .dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
  66         .dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
  67         .path_refresh_time = MESH_PATH_REFRESH_TIME,
  68         .min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
  69         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
  70         .dot11MeshGateAnnouncementProtocol = false,
  71         .dot11MeshForwarding = true,
  72         .rssi_threshold = MESH_RSSI_THRESHOLD,
  73         .ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
  74         .dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
  75         .dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
  76         .dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
  77         .power_mode = NL80211_MESH_POWER_ACTIVE,
  78         .dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
  79         .plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
  80 };
  81
  82 const struct mesh_setup default_mesh_setup = {
  83         /* cfg80211_join_mesh() will pick a channel if needed */
  84         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  85         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  86         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  87         .auth_id = 0, /* open */
  88         .ie = NULL,
  89         .ie_len = 0,
  90         .is_secure = false,
  91         .user_mpm = false,
  92         .beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
  93         .dtim_period = MESH_DEFAULT_DTIM_PERIOD,
  94 };
  95
  96 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  97                          struct net_device *dev,
  98                          struct mesh_setup *setup,
  99                          const struct mesh_config *conf)
 100 {
 101         struct wireless_dev *wdev = dev->ieee80211_ptr;
 102         int err;
 103
 104         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
 105
 106         ASSERT_WDEV_LOCK(wdev);
 107
 108         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 109                 return -EOPNOTSUPP;
 110
 111         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 112               setup->is_secure)
 113                 return -EOPNOTSUPP;
 114
 115         if (wdev->mesh_id_len)
 116                 return -EALREADY;
 117
 118         if (!setup->mesh_id_len)
 119                 return -EINVAL;
 120
 121         if (!rdev->ops->join_mesh)
 122                 return -EOPNOTSUPP;
 123
 124         if (!setup->chandef.chan) {
 125                 /* if no channel explicitly given, use preset channel */
 126                 setup->chandef = wdev->preset_chandef;
 127         }
 128
 129         if (!setup->chandef.chan) {
 130                 /* if we don't have that either, use the first usable channel */
 131                 enum ieee80211_band band;
 132
 133                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 134                         struct ieee80211_supported_band *sband;
 135                         struct ieee80211_channel *chan;
 136                         int i;
 137
 138                         sband = rdev->wiphy.bands[band];
 139                         if (!sband)
 140                                 continue;
 141
 142                         for (i = 0; i < sband->n_channels; i++) {
 143                                 chan = &sband->channels[i];
 144                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 145                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 146                                                    IEEE80211_CHAN_DISABLED |
 147                                                    IEEE80211_CHAN_RADAR))
 148                                         continue;
 149                                 setup->chandef.chan = chan;
 150                                 break;
 151                         }
 152
 153                         if (setup->chandef.chan)
 154                                 break;
 155                 }
 156
 157                 /* no usable channel ... */
 158                 if (!setup->chandef.chan)
 159                         return -EINVAL;
 160
 161                 setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 162                 setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 163         }
 164
 165         /*
 166          * check if basic rates are available otherwise use mandatory rates as
 167          * basic rates
 168          */
 169         if (!setup->basic_rates) {
 170                 enum nl80211_bss_scan_width scan_width;
 171                 struct ieee80211_supported_band *sband =
 172                                 rdev->wiphy.bands[setup->chandef.chan->band];
 173                 scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
 174                 setup->basic_rates = ieee80211_mandatory_rates(sband,
 175                                                                scan_width);
 176         }
 177
 178         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
 179                 return -EINVAL;
 180
 181         err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
 182                                     CHAN_MODE_SHARED);
 183         if (err)
 184                 return err;
 185
 186         err = rdev_join_mesh(rdev, dev, conf, setup);
 187         if (!err) {
 188                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 189                 wdev->mesh_id_len = setup->mesh_id_len;
 190                 wdev->channel = setup->chandef.chan;
 191         }
 192
 193         return err;
 194 }
 195
 196 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 197                        struct net_device *dev,
 198                        struct mesh_setup *setup,
 199                        const struct mesh_config *conf)
 200 {
 201         struct wireless_dev *wdev = dev->ieee80211_ptr;
 202         int err;
 203
 204         wdev_lock(wdev);
 205         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 206         wdev_unlock(wdev);
 207
 208         return err;
 209 }
 210
 211 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 212                               struct wireless_dev *wdev,
 213                               struct cfg80211_chan_def *chandef)
 214 {
 215         int err;
 216
 217         /*
 218          * Workaround for libertas (only!), it puts the interface
 219          * into mesh mode but doesn't implement join_mesh. Instead,
 220          * it is configured via sysfs and then joins the mesh when
 221          * you set the channel. Note that the libertas mesh isn't
 222          * compatible with 802.11 mesh.
 223          */
 224         if (rdev->ops->libertas_set_mesh_channel) {
 225                 if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 226                         return -EINVAL;
 227
 228                 if (!netif_running(wdev->netdev))
 229                         return -ENETDOWN;
 230
 231                 err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
 232                                             CHAN_MODE_SHARED);
 233                 if (err)
 234                         return err;
 235
 236                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 237                                                      chandef->chan);
 238                 if (!err)
 239                         wdev->channel = chandef->chan;
 240
 241                 return err;
 242         }
 243
 244         if (wdev->mesh_id_len)
 245                 return -EBUSY;
 246
 247         wdev->preset_chandef = *chandef;
 248         return 0;
 249 }
 250
 251 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 252                                  struct net_device *dev)
 253 {
 254         struct wireless_dev *wdev = dev->ieee80211_ptr;
 255         int err;
 256
 257         ASSERT_WDEV_LOCK(wdev);
 258
 259         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 260                 return -EOPNOTSUPP;
 261
 262         if (!rdev->ops->leave_mesh)
 263                 return -EOPNOTSUPP;
 264
 265         if (!wdev->mesh_id_len)
 266                 return -ENOTCONN;
 267
 268         err = rdev_leave_mesh(rdev, dev);
 269         if (!err) {
 270                 wdev->mesh_id_len = 0;
 271                 wdev->channel = NULL;
 272         }
 273
 274         return err;
 275 }
 276
 277 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 278                         struct net_device *dev)
 279 {
 280         struct wireless_dev *wdev = dev->ieee80211_ptr;
 281         int err;
 282
 283         wdev_lock(wdev);
 284         err = __cfg80211_leave_mesh(rdev, dev);
 285         wdev_unlock(wdev);
 286
 287         return err;
 288 }