net/wireless/mesh.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ieee80211.h>
   3 #include <linux/export.h>
   4 #include <net/cfg80211.h>
   5 #include "nl80211.h"
   6 #include "core.h"
   7 #include "rdev-ops.h"
   8
   9 /* Default values, timeouts in ms */
  10 #define MESH_TTL                31
  11 #define MESH_DEFAULT_ELEMENT_TTL 31
  12 #define MESH_MAX_RETR           3
  13 #define MESH_RET_T              100
  14 #define MESH_CONF_T             100
  15 #define MESH_HOLD_T             100
  16
  17 #define MESH_PATH_TIMEOUT       5000
  18 #define MESH_RANN_INTERVAL      5000
  19 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
  20 #define MESH_ROOT_INTERVAL     5000
  21 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
  22 #define MESH_DEFAULT_PLINK_TIMEOUT      1800 /* timeout in seconds */
  23
  24 /*
  25  * Minimum interval between two consecutive PREQs originated by the same
  26  * interface
  27  */
  28 #define MESH_PREQ_MIN_INT       10
  29 #define MESH_PERR_MIN_INT       100
  30 #define MESH_DIAM_TRAVERSAL_TIME 50
  31
  32 #define MESH_RSSI_THRESHOLD     0
  33
  34 /*
  35  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  36  * before timing out.  This way it will remain ACTIVE and no data frames
  37  * will be unnecessarily held in the pending queue.
  38  */
  39 #define MESH_PATH_REFRESH_TIME                  1000
  40 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
  41
  42 /* Default maximum number of established plinks per interface */
  43 #define MESH_MAX_ESTAB_PLINKS   32
  44
  45 #define MESH_MAX_PREQ_RETRIES   4
  46
  47 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
  48
  49 #define MESH_DEFAULT_BEACON_INTERVAL    1000    /* in 1024 us units (=TUs) */
  50 #define MESH_DEFAULT_DTIM_PERIOD        2
  51 #define MESH_DEFAULT_AWAKE_WINDOW       10      /* in 1024 us units (=TUs) */
  52
  53 const struct mesh_config default_mesh_config = {
  54         .dot11MeshRetryTimeout = MESH_RET_T,
  55         .dot11MeshConfirmTimeout = MESH_CONF_T,
  56         .dot11MeshHoldingTimeout = MESH_HOLD_T,
  57         .dot11MeshMaxRetries = MESH_MAX_RETR,
  58         .dot11MeshTTL = MESH_TTL,
  59         .element_ttl = MESH_DEFAULT_ELEMENT_TTL,
  60         .auto_open_plinks = true,
  61         .dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
  62         .dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
  63         .dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
  64         .dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
  65         .dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
  66         .dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
  67         .dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
  68         .path_refresh_time = MESH_PATH_REFRESH_TIME,
  69         .min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
  70         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
  71         .dot11MeshGateAnnouncementProtocol = false,
  72         .dot11MeshForwarding = true,
  73         .rssi_threshold = MESH_RSSI_THRESHOLD,
  74         .ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
  75         .dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
  76         .dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
  77         .dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
  78         .power_mode = NL80211_MESH_POWER_ACTIVE,
  79         .dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
  80         .plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
  81         .dot11MeshNolearn = false,
  82 };
  83
  84 const struct mesh_setup default_mesh_setup = {
  85         /* cfg80211_join_mesh() will pick a channel if needed */
  86         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
  87         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
  88         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
  89         .auth_id = 0, /* open */
  90         .ie = NULL,
  91         .ie_len = 0,
  92         .is_secure = false,
  93         .user_mpm = false,
  94         .beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
  95         .dtim_period = MESH_DEFAULT_DTIM_PERIOD,
  96 };
  97
  98 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
  99                          struct net_device *dev,
 100                          struct mesh_setup *setup,
 101                          const struct mesh_config *conf)
 102 {
 103         struct wireless_dev *wdev = dev->ieee80211_ptr;
 104         int err;
 105
 106         BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
 107
 108         ASSERT_WDEV_LOCK(wdev);
 109
 110         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 111                 return -EOPNOTSUPP;
 112
 113         if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 114               setup->is_secure)
 115                 return -EOPNOTSUPP;
 116
 117         if (wdev->mesh_id_len)
 118                 return -EALREADY;
 119
 120         if (!setup->mesh_id_len)
 121                 return -EINVAL;
 122
 123         if (!rdev->ops->join_mesh)
 124                 return -EOPNOTSUPP;
 125
 126         if (!setup->chandef.chan) {
 127                 /* if no channel explicitly given, use preset channel */
 128                 setup->chandef = wdev->preset_chandef;
 129         }
 130
 131         if (!setup->chandef.chan) {
 132                 /* if we don't have that either, use the first usable channel */
 133                 enum nl80211_band band;
 134
 135                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
 136                         struct ieee80211_supported_band *sband;
 137                         struct ieee80211_channel *chan;
 138                         int i;
 139
 140                         sband = rdev->wiphy.bands[band];
 141                         if (!sband)
 142                                 continue;
 143
 144                         for (i = 0; i < sband->n_channels; i++) {
 145                                 chan = &sband->channels[i];
 146                                 if (chan->flags & (IEEE80211_CHAN_NO_IR |
 147                                                    IEEE80211_CHAN_DISABLED |
 148                                                    IEEE80211_CHAN_RADAR))
 149                                         continue;
 150                                 setup->chandef.chan = chan;
 151                                 break;
 152                         }
 153
 154                         if (setup->chandef.chan)
 155                                 break;
 156                 }
 157
 158                 /* no usable channel ... */
 159                 if (!setup->chandef.chan)
 160                         return -EINVAL;
 161
 162                 setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 163                 setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 164         }
 165
 166         /*
 167          * check if basic rates are available otherwise use mandatory rates as
 168          * basic rates
 169          */
 170         if (!setup->basic_rates) {
 171                 enum nl80211_bss_scan_width scan_width;
 172                 struct ieee80211_supported_band *sband =
 173                                 rdev->wiphy.bands[setup->chandef.chan->band];
 174
 175                 if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
 176                         int i;
 177
 178                         /*
 179                          * Older versions selected the mandatory rates for
 180                          * 2.4 GHz as well, but were broken in that only
 181                          * 1 Mbps was regarded as a mandatory rate. Keep
 182                          * using just 1 Mbps as the default basic rate for
 183                          * mesh to be interoperable with older versions.
 184                          */
 185                         for (i = 0; i < sband->n_bitrates; i++) {
 186                                 if (sband->bitrates[i].bitrate == 10) {
 187                                         setup->basic_rates = BIT(i);
 188                                         break;
 189                                 }
 190                         }
 191                 } else {
 192                         scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
 193                         setup->basic_rates = ieee80211_mandatory_rates(sband,
 194                                                                        scan_width);
 195                 }
 196         }
 197
 198         err = cfg80211_chandef_dfs_required(&rdev->wiphy,
 199                                             &setup->chandef,
 200                                             NL80211_IFTYPE_MESH_POINT);
 201         if (err < 0)
 202                 return err;
 203         if (err > 0 && !setup->userspace_handles_dfs)
 204                 return -EINVAL;
 205
 206         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
 207                                      NL80211_IFTYPE_MESH_POINT))
 208                 return -EINVAL;
 209
 210         err = rdev_join_mesh(rdev, dev, conf, setup);
 211         if (!err) {
 212                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 213                 wdev->mesh_id_len = setup->mesh_id_len;
 214                 wdev->chandef = setup->chandef;
 215                 wdev->beacon_interval = setup->beacon_interval;
 216         }
 217
 218         return err;
 219 }
 220
 221 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 222                               struct wireless_dev *wdev,
 223                               struct cfg80211_chan_def *chandef)
 224 {
 225         int err;
 226
 227         /*
 228          * Workaround for libertas (only!), it puts the interface
 229          * into mesh mode but doesn't implement join_mesh. Instead,
 230          * it is configured via sysfs and then joins the mesh when
 231          * you set the channel. Note that the libertas mesh isn't
 232          * compatible with 802.11 mesh.
 233          */
 234         if (rdev->ops->libertas_set_mesh_channel) {
 235                 if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 236                         return -EINVAL;
 237
 238                 if (!netif_running(wdev->netdev))
 239                         return -ENETDOWN;
 240
 241                 err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 242                                                      chandef->chan);
 243                 if (!err)
 244                         wdev->chandef = *chandef;
 245
 246                 return err;
 247         }
 248
 249         if (wdev->mesh_id_len)
 250                 return -EBUSY;
 251
 252         wdev->preset_chandef = *chandef;
 253         return 0;
 254 }
 255
 256 int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 257                           struct net_device *dev)
 258 {
 259         struct wireless_dev *wdev = dev->ieee80211_ptr;
 260         int err;
 261
 262         ASSERT_WDEV_LOCK(wdev);
 263
 264         if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 265                 return -EOPNOTSUPP;
 266
 267         if (!rdev->ops->leave_mesh)
 268                 return -EOPNOTSUPP;
 269
 270         if (!wdev->mesh_id_len)
 271                 return -ENOTCONN;
 272
 273         err = rdev_leave_mesh(rdev, dev);
 274         if (!err) {
 275                 wdev->conn_owner_nlportid = 0;
 276                 wdev->mesh_id_len = 0;
 277                 wdev->beacon_interval = 0;
 278                 memset(&wdev->chandef, 0, sizeof(wdev->chandef));
 279                 rdev_set_qos_map(rdev, dev, NULL);
 280                 cfg80211_sched_dfs_chan_update(rdev);
 281         }
 282
 283         return err;
 284 }
 285
 286 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 287                         struct net_device *dev)
 288 {
 289         struct wireless_dev *wdev = dev->ieee80211_ptr;
 290         int err;
 291
 292         wdev_lock(wdev);
 293         err = __cfg80211_leave_mesh(rdev, dev);
 294         wdev_unlock(wdev);
 295
 296         return err;
 297 }