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         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  77         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  78         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  79         .ie = NULL,
  80         .ie_len = 0,
  81         .is_secure = false,
  82 };
  83
  84 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  85                          struct net_device *dev,
  86                          struct mesh_setup *setup,
  87                          const struct mesh_config *conf)
  88 {
  89         struct wireless_dev *wdev = dev->ieee80211_ptr;
  90         int err;
  91
  92         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
  93
  94         ASSERT_WDEV_LOCK(wdev);
  95
  96         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
  97                 return -EOPNOTSUPP;
  98
  99         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 100               setup->is_secure)
 101                 return -EOPNOTSUPP;
 102
 103         if (wdev->mesh_id_len)
 104                 return -EALREADY;
 105
 106         if (!setup->mesh_id_len)
 107                 return -EINVAL;
 108
 109         if (!rdev->ops->join_mesh)
 110                 return -EOPNOTSUPP;
 111
 112         if (!setup->chandef.chan) {
 113                 /* if no channel explicitly given, use preset channel */
 114                 setup->chandef = wdev->preset_chandef;
 115         }
 116
 117         if (!setup->chandef.chan) {
 118                 /* if we don't have that either, use the first usable channel */
 119                 enum ieee80211_band band;
 120
 121                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 122                         struct ieee80211_supported_band *sband;
 123                         struct ieee80211_channel *chan;
 124                         int i;
 125
 126                         sband = rdev->wiphy.bands[band];
 127                         if (!sband)
 128                                 continue;
 129
 130                         for (i = 0; i < sband->n_channels; i++) {
 131                                 chan = &sband->channels[i];
 132                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 133                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 134                                                    IEEE80211_CHAN_DISABLED |
 135                                                    IEEE80211_CHAN_RADAR))
 136                                         continue;
 137                                 setup->chandef.chan = chan;
 138                                 break;
 139                         }
 140
 141                         if (setup->chandef.chan)
 142                                 break;
 143                 }
 144
 145                 /* no usable channel ... */
 146                 if (!setup->chandef.chan)
 147                         return -EINVAL;
 148
 149                 setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 150                 setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 151         }
 152
 153         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
 154                 return -EINVAL;
 155
 156         err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
 157                                     CHAN_MODE_SHARED);
 158         if (err)
 159                 return err;
 160
 161         err = rdev_join_mesh(rdev, dev, conf, setup);
 162         if (!err) {
 163                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 164                 wdev->mesh_id_len = setup->mesh_id_len;
 165                 wdev->channel = setup->chandef.chan;
 166         }
 167
 168         return err;
 169 }
 170
 171 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 172                        struct net_device *dev,
 173                        struct mesh_setup *setup,
 174                        const struct mesh_config *conf)
 175 {
 176         struct wireless_dev *wdev = dev->ieee80211_ptr;
 177         int err;
 178
 179         mutex_lock(&rdev->devlist_mtx);
 180         wdev_lock(wdev);
 181         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 182         wdev_unlock(wdev);
 183         mutex_unlock(&rdev->devlist_mtx);
 184
 185         return err;
 186 }
 187
 188 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 189                               struct wireless_dev *wdev,
 190                               struct cfg80211_chan_def *chandef)
 191 {
 192         int err;
 193
 194         /*
 195          * Workaround for libertas (only!), it puts the interface
 196          * into mesh mode but doesn't implement join_mesh. Instead,
 197          * it is configured via sysfs and then joins the mesh when
 198          * you set the channel. Note that the libertas mesh isn't
 199          * compatible with 802.11 mesh.
 200          */
 201         if (rdev->ops->libertas_set_mesh_channel) {
 202                 if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 203                         return -EINVAL;
 204
 205                 if (!netif_running(wdev->netdev))
 206                         return -ENETDOWN;
 207
 208                 err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
 209                                             CHAN_MODE_SHARED);
 210                 if (err)
 211                         return err;
 212
 213                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 214                                                      chandef->chan);
 215                 if (!err)
 216                         wdev->channel = chandef->chan;
 217
 218                 return err;
 219         }
 220
 221         if (wdev->mesh_id_len)
 222                 return -EBUSY;
 223
 224         wdev->preset_chandef = *chandef;
 225         return 0;
 226 }
 227
 228 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
 229                 const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
 230 {
 231         struct wireless_dev *wdev = dev->ieee80211_ptr;
 232
 233         trace_cfg80211_notify_new_peer_candidate(dev, macaddr);
 234         if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
 235                 return;
 236
 237         nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
 238                         macaddr, ie, ie_len, gfp);
 239 }
 240 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
 241
 242 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 243                                  struct net_device *dev)
 244 {
 245         struct wireless_dev *wdev = dev->ieee80211_ptr;
 246         int err;
 247
 248         ASSERT_WDEV_LOCK(wdev);
 249
 250         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 251                 return -EOPNOTSUPP;
 252
 253         if (!rdev->ops->leave_mesh)
 254                 return -EOPNOTSUPP;
 255
 256         if (!wdev->mesh_id_len)
 257                 return -ENOTCONN;
 258
 259         err = rdev_leave_mesh(rdev, dev);
 260         if (!err) {
 261                 wdev->mesh_id_len = 0;
 262                 wdev->channel = NULL;
 263         }
 264
 265         return err;
 266 }
 267
 268 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 269                         struct net_device *dev)
 270 {
 271         struct wireless_dev *wdev = dev->ieee80211_ptr;
 272         int err;
 273
 274         wdev_lock(wdev);
 275         err = __cfg80211_leave_mesh(rdev, dev);
 276         wdev_unlock(wdev);
 277
 278         return err;
 279 }