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