LXR linux/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
  53const 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
  84const 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
  98int __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
 221int 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
 256int __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
 286int 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}
 298