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
  18 /*
  19  * Minimum interval between two consecutive PREQs originated by the same
  20  * interface
  21  */
  22 #define MESH_PREQ_MIN_INT       10
  23 #define MESH_PERR_MIN_INT       100
  24 #define MESH_DIAM_TRAVERSAL_TIME 50
  25
  26 #define MESH_RSSI_THRESHOLD     0
  27
  28 /*
  29  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  30  * before timing out.  This way it will remain ACTIVE and no data frames
  31  * will be unnecessarily held in the pending queue.
  32  */
  33 #define MESH_PATH_REFRESH_TIME                  1000
  34 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
  35
  36 /* Default maximum number of established plinks per interface */
  37 #define MESH_MAX_ESTAB_PLINKS   32
  38
  39 #define MESH_MAX_PREQ_RETRIES   4
  40
  41 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
  42
  43 const struct mesh_config default_mesh_config = {
  44         .dot11MeshRetryTimeout = MESH_RET_T,
  45         .dot11MeshConfirmTimeout = MESH_CONF_T,
  46         .dot11MeshHoldingTimeout = MESH_HOLD_T,
  47         .dot11MeshMaxRetries = MESH_MAX_RETR,
  48         .dot11MeshTTL = MESH_TTL,
  49         .element_ttl = MESH_DEFAULT_ELEMENT_TTL,
  50         .auto_open_plinks = true,
  51         .dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
  52         .dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
  53         .dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
  54         .dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
  55         .dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
  56         .dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
  57         .dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
  58         .path_refresh_time = MESH_PATH_REFRESH_TIME,
  59         .min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
  60         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
  61         .dot11MeshGateAnnouncementProtocol = false,
  62         .dot11MeshForwarding = true,
  63         .rssi_threshold = MESH_RSSI_THRESHOLD,
  64         .ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
  65 };
  66
  67 const struct mesh_setup default_mesh_setup = {
  68         /* cfg80211_join_mesh() will pick a channel if needed */
  69         .channel = NULL,
  70         .channel_type = NL80211_CHAN_NO_HT,
  71         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  72         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  73         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  74         .ie = NULL,
  75         .ie_len = 0,
  76         .is_secure = false,
  77 };
  78
  79 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  80                          struct net_device *dev,
  81                          struct mesh_setup *setup,
  82                          const struct mesh_config *conf)
  83 {
  84         struct wireless_dev *wdev = dev->ieee80211_ptr;
  85         int err;
  86
  87         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
  88
  89         ASSERT_WDEV_LOCK(wdev);
  90
  91         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
  92                 return -EOPNOTSUPP;
  93
  94         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
  95               setup->is_secure)
  96                 return -EOPNOTSUPP;
  97
  98         if (wdev->mesh_id_len)
  99                 return -EALREADY;
 100
 101         if (!setup->mesh_id_len)
 102                 return -EINVAL;
 103
 104         if (!rdev->ops->join_mesh)
 105                 return -EOPNOTSUPP;
 106
 107         if (!setup->channel) {
 108                 /* if no channel explicitly given, use preset channel */
 109                 setup->channel = wdev->preset_chan;
 110                 setup->channel_type = wdev->preset_chantype;
 111         }
 112
 113         if (!setup->channel) {
 114                 /* if we don't have that either, use the first usable channel */
 115                 enum ieee80211_band band;
 116
 117                 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 118                         struct ieee80211_supported_band *sband;
 119                         struct ieee80211_channel *chan;
 120                         int i;
 121
 122                         sband = rdev->wiphy.bands[band];
 123                         if (!sband)
 124                                 continue;
 125
 126                         for (i = 0; i < sband->n_channels; i++) {
 127                                 chan = &sband->channels[i];
 128                                 if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
 129                                                    IEEE80211_CHAN_PASSIVE_SCAN |
 130                                                    IEEE80211_CHAN_DISABLED |
 131                                                    IEEE80211_CHAN_RADAR))
 132                                         continue;
 133                                 setup->channel = chan;
 134                                 break;
 135                         }
 136
 137                         if (setup->channel)
 138                                 break;
 139                 }
 140
 141                 /* no usable channel ... */
 142                 if (!setup->channel)
 143                         return -EINVAL;
 144
 145                 setup->channel_type = NL80211_CHAN_NO_HT;
 146         }
 147
 148         if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, setup->channel,
 149                                           setup->channel_type))
 150                 return -EINVAL;
 151
 152         err = rdev->ops->join_mesh(&rdev->wiphy, dev, conf, setup);
 153         if (!err) {
 154                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 155                 wdev->mesh_id_len = setup->mesh_id_len;
 156         }
 157
 158         return err;
 159 }
 160
 161 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 162                        struct net_device *dev,
 163                        struct mesh_setup *setup,
 164                        const struct mesh_config *conf)
 165 {
 166         struct wireless_dev *wdev = dev->ieee80211_ptr;
 167         int err;
 168
 169         wdev_lock(wdev);
 170         err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 171         wdev_unlock(wdev);
 172
 173         return err;
 174 }
 175
 176 int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
 177                            struct wireless_dev *wdev, int freq,
 178                            enum nl80211_channel_type channel_type)
 179 {
 180         struct ieee80211_channel *channel;
 181
 182         channel = rdev_freq_to_chan(rdev, freq, channel_type);
 183         if (!channel || !cfg80211_can_beacon_sec_chan(&rdev->wiphy,
 184                                                       channel,
 185                                                       channel_type)) {
 186                 return -EINVAL;
 187         }
 188
 189         /*
 190          * Workaround for libertas (only!), it puts the interface
 191          * into mesh mode but doesn't implement join_mesh. Instead,
 192          * it is configured via sysfs and then joins the mesh when
 193          * you set the channel. Note that the libertas mesh isn't
 194          * compatible with 802.11 mesh.
 195          */
 196         if (rdev->ops->libertas_set_mesh_channel) {
 197                 if (channel_type != NL80211_CHAN_NO_HT)
 198                         return -EINVAL;
 199
 200                 if (!netif_running(wdev->netdev))
 201                         return -ENETDOWN;
 202                 return rdev->ops->libertas_set_mesh_channel(&rdev->wiphy,
 203                                                             wdev->netdev,
 204                                                             channel);
 205         }
 206
 207         if (wdev->mesh_id_len)
 208                 return -EBUSY;
 209
 210         wdev->preset_chan = channel;
 211         wdev->preset_chantype = channel_type;
 212         return 0;
 213 }
 214
 215 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
 216                 const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
 217 {
 218         struct wireless_dev *wdev = dev->ieee80211_ptr;
 219
 220         if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
 221                 return;
 222
 223         nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
 224                         macaddr, ie, ie_len, gfp);
 225 }
 226 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
 227
 228 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 229                                  struct net_device *dev)
 230 {
 231         struct wireless_dev *wdev = dev->ieee80211_ptr;
 232         int err;
 233
 234         ASSERT_WDEV_LOCK(wdev);
 235
 236         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 237                 return -EOPNOTSUPP;
 238
 239         if (!rdev->ops->leave_mesh)
 240                 return -EOPNOTSUPP;
 241
 242         if (!wdev->mesh_id_len)
 243                 return -ENOTCONN;
 244
 245         err = rdev->ops->leave_mesh(&rdev->wiphy, dev);
 246         if (!err)
 247                 wdev->mesh_id_len = 0;
 248         return err;
 249 }
 250
 251 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         wdev_lock(wdev);
 258         err = __cfg80211_leave_mesh(rdev, dev);
 259         wdev_unlock(wdev);
 260
 261         return err;
 262 }