/* We only need a valid sta if user configured a minimum rssi_threshold. */ staticbool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, struct sta_info *sta)
{
s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; return rssi_threshold == 0 ||
(sta &&
(s8)-ewma_signal_read(&sta->deflink.rx_stats_avg.signal) >
rssi_threshold);
}
/** * mesh_plink_fsm_restart - restart a mesh peer link finite state machine * * @sta: mesh peer link to restart * * Locking: this function must be called holding sta->mesh->plink_lock
*/ staticinlinevoid mesh_plink_fsm_restart(struct sta_info *sta)
{
lockdep_assert_held(&sta->mesh->plink_lock);
sta->mesh->plink_state = NL80211_PLINK_LISTEN;
sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
sta->mesh->plink_retries = 0;
}
/* * mesh_set_short_slot_time - enable / disable ERP short slot time. * * The standard indirectly mandates mesh STAs to turn off short slot time by * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we * can't be sneaky about it. Enable short slot time if all mesh STAs in the * MBSS support ERP rates. * * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
*/ static u64 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
{ struct ieee80211_local *local = sdata->local; struct ieee80211_supported_band *sband; struct sta_info *sta;
u32 erp_rates = 0;
u64 changed = 0; int i; bool short_slot = false;
sband = ieee80211_get_sband(sdata); if (!sband) return changed;
out: if (sdata->vif.bss_conf.use_short_slot != short_slot) {
sdata->vif.bss_conf.use_short_slot = short_slot;
changed = BSS_CHANGED_ERP_SLOT;
mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
sdata->vif.addr, short_slot);
} return changed;
}
/** * mesh_set_ht_prot_mode - set correct HT protection mode * @sdata: the (mesh) interface to handle * * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode * is selected if all peers in our 20/40MHz MBSS support HT and at least one * HT20 peer is present. Otherwise no-protection mode is selected. * * Returns: BSS_CHANGED_HT or 0 for no change
*/ static u64 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
{ struct ieee80211_local *local = sdata->local; struct sta_info *sta;
u16 ht_opmode; bool non_ht_sta = false, ht20_sta = false;
switch (sdata->vif.bss_conf.chanreq.oper.width) { case NL80211_CHAN_WIDTH_20_NOHT: case NL80211_CHAN_WIDTH_5: case NL80211_CHAN_WIDTH_10: return 0; default: break;
}
/** * __mesh_plink_deactivate - deactivate mesh peer link * * @sta: mesh peer link to deactivate * * Mesh paths with this peer as next hop should be flushed * by the caller outside of plink_lock. * * Returns: beacon changed flag if the beacon content changed. * * Locking: the caller must hold sta->mesh->plink_lock
*/ static u64 __mesh_plink_deactivate(struct sta_info *sta)
{ struct ieee80211_sub_if_data *sdata = sta->sdata;
u64 changed = 0;
lockdep_assert_held(&sta->mesh->plink_lock);
if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
changed = mesh_plink_dec_estab_count(sdata);
sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
/** * mesh_plink_deactivate - deactivate mesh peer link * * @sta: mesh peer link to deactivate * * All mesh paths with this peer as next hop will be flushed * * Returns: beacon changed flag if the beacon content changed.
*/
u64 mesh_plink_deactivate(struct sta_info *sta)
{ struct ieee80211_sub_if_data *sdata = sta->sdata;
u64 changed;
if (bw != sta->sta.deflink.bandwidth)
changed |= IEEE80211_RC_BW_CHANGED;
/* HT peer is operating 20MHz-only */ if (elems->ht_operation &&
!(elems->ht_operation->ht_param &
IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20)
changed |= IEEE80211_RC_BW_CHANGED;
sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20;
}
/* FIXME: this check is wrong without SW rate control */ if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
rate_control_rate_init(&sta->deflink); else
rate_control_rate_update(local, sband, &sta->deflink, changed);
out:
spin_unlock_bh(&sta->mesh->plink_lock);
}
/* Userspace handles station allocation */ if (sdata->u.mesh.user_mpm ||
sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { if (mesh_peer_accepts_plinks(elems) &&
mesh_plink_availables(sdata)) { int sig = 0;
if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
sig = rx_status->signal;
/* * This STA is valid because sta_info_destroy() will * timer_delete_sync() this timer after having made sure * it cannot be re-added (by deleting the plink.)
*/
sta = mesh->plink_sta;
if (sta->sdata->local->quiescing) return;
spin_lock_bh(&sta->mesh->plink_lock);
/* If a timer fires just before a state transition on another CPU, * we may have already extended the timeout and changed state by the * time we've acquired the lock and arrived here. In that case, * skip this timer and wait for the new one.
*/ if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer adjusted)",
sta->sta.addr, mplstates[sta->mesh->plink_state]);
spin_unlock_bh(&sta->mesh->plink_lock); return;
}
/* timer_delete() and handler may race when entering these states */ if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer deleted)",
sta->sta.addr, mplstates[sta->mesh->plink_state]);
spin_unlock_bh(&sta->mesh->plink_lock); return;
}
mpl_dbg(sta->sdata, "Mesh plink timer for %pM fired on state %s\n",
sta->sta.addr, mplstates[sta->mesh->plink_state]);
sdata = sta->sdata;
mshcfg = &sdata->u.mesh.mshcfg;
mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
mplstates[sta->mesh->plink_state], mplevents[event]);
spin_lock_bh(&sta->mesh->plink_lock); switch (sta->mesh->plink_state) { case NL80211_PLINK_LISTEN: switch (event) { case CLS_ACPT:
mesh_plink_fsm_restart(sta); break; case OPN_ACPT:
sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
sta->mesh->llid = mesh_get_new_llid(sdata);
mesh_plink_timer_set(sta,
mshcfg->dot11MeshRetryTimeout);
/* set the non-peer mode to active during peering */
changed |= ieee80211_mps_local_status_update(sdata);
action = WLAN_SP_MESH_PEERING_OPEN; break; default: break;
} break; case NL80211_PLINK_OPN_SNT: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT:
mesh_plink_close(sdata, sta, event);
action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT: /* retry timer is left untouched */
sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
action = WLAN_SP_MESH_PEERING_CONFIRM; break; case CNF_ACPT:
sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); break; default: break;
} break; case NL80211_PLINK_OPN_RCVD: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT:
mesh_plink_close(sdata, sta, event);
action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT:
action = WLAN_SP_MESH_PEERING_CONFIRM; break; case CNF_ACPT:
changed |= mesh_plink_establish(sdata, sta); break; default: break;
} break; case NL80211_PLINK_CNF_RCVD: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT:
mesh_plink_close(sdata, sta, event);
action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT:
changed |= mesh_plink_establish(sdata, sta);
action = WLAN_SP_MESH_PEERING_CONFIRM; break; default: break;
} break; case NL80211_PLINK_ESTAB: switch (event) { case CLS_ACPT:
changed |= __mesh_plink_deactivate(sta);
changed |= mesh_set_ht_prot_mode(sdata);
changed |= mesh_set_short_slot_time(sdata);
mesh_plink_close(sdata, sta, event);
action = WLAN_SP_MESH_PEERING_CLOSE;
flush = true; break; case OPN_ACPT:
action = WLAN_SP_MESH_PEERING_CONFIRM; break; default: break;
} break; case NL80211_PLINK_HOLDING: switch (event) { case CLS_ACPT:
timer_delete(&sta->mesh->plink_timer);
mesh_plink_fsm_restart(sta); break; case OPN_ACPT: case CNF_ACPT: case OPN_RJCT: case CNF_RJCT:
action = WLAN_SP_MESH_PEERING_CLOSE; break; default: break;
} break; default: /* should not get here, PLINK_BLOCKED is dealt with at the * beginning of the function
*/ break;
}
spin_unlock_bh(&sta->mesh->plink_lock); if (flush)
mesh_path_flush_by_nexthop(sta); if (action) {
mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
sta->mesh->llid, sta->mesh->plid,
sta->mesh->reason);
/* also send confirm in open case */ if (action == WLAN_SP_MESH_PEERING_OPEN) {
mesh_plink_frame_tx(sdata, sta,
WLAN_SP_MESH_PEERING_CONFIRM,
sta->sta.addr, sta->mesh->llid,
sta->mesh->plid, 0);
}
}
return changed;
}
/* * mesh_plink_get_event - get correct MPM event * * @sdata: interface * @sta: peer, leave NULL if processing a frame from a new suitable peer * @elems: peering management IEs * @ftype: frame type * @llid: peer's peer link ID * @plid: peer's local link ID * * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as * an error.
*/ staticenum plink_event
mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, struct ieee802_11_elems *elems, enum ieee80211_self_protected_actioncode ftype,
u16 llid, u16 plid)
{ enum plink_event event = PLINK_UNDEFINED;
u8 ie_len = elems->peering_len; bool matches_local;
/* deny open request from non-matching peer */ if (!matches_local && !sta) {
event = OPN_RJCT; goto out;
}
if (!sta) { if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); goto out;
} /* ftype == WLAN_SP_MESH_PEERING_OPEN */ if (!mesh_plink_free_count(sdata)) {
mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); goto out;
}
/* new matching peer */
event = OPN_ACPT; goto out;
} else { if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); goto out;
} if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) goto out;
}
switch (ftype) { case WLAN_SP_MESH_PEERING_OPEN: if (!matches_local)
event = OPN_RJCT; elseif (!mesh_plink_free_count(sdata) ||
(sta->mesh->plid && sta->mesh->plid != plid))
event = OPN_IGNR; else
event = OPN_ACPT; break; case WLAN_SP_MESH_PEERING_CONFIRM: if (!matches_local)
event = CNF_RJCT; elseif (!mesh_plink_free_count(sdata) ||
sta->mesh->llid != llid ||
(sta->mesh->plid && sta->mesh->plid != plid))
event = CNF_IGNR; else
event = CNF_ACPT; break; case WLAN_SP_MESH_PEERING_CLOSE: if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) /* Do not check for llid or plid. This does not * follow the standard but since multiple plinks * per sta are not supported, it is necessary in * order to avoid a livelock when MP A sees an * establish peer link to MP B but MP B does not * see it. This can be caused by a timeout in * B's peer link establishment or B beign * restarted.
*/
event = CLS_ACPT; elseif (sta->mesh->plid != plid)
event = CLS_IGNR; elseif (ie_len == 8 && sta->mesh->llid != llid)
event = CLS_IGNR; else
event = CLS_ACPT; break; default:
mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); break;
}
if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
(!elems->mesh_id || !elems->mesh_config)) {
mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); return;
} /* Note the lines below are correct, the llid in the frame is the plid * from the point of view of this host.
*/
plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
(ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
/* WARNING: Only for sta pointer, is dropped & re-acquired */
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
!rssi_threshold_check(sdata, sta)) {
mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
mgmt->sa); goto unlock_rcu;
}
/* Now we will figure out the appropriate event... */
event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
if (event == OPN_ACPT) {
rcu_read_unlock(); /* allocate sta entry if necessary and update info */
sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); if (!sta) {
mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); goto unlock_rcu;
}
sta->mesh->plid = plid;
} elseif (!sta && event == OPN_RJCT) {
mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
mgmt->sa, 0, plid,
WLAN_REASON_MESH_CONFIG); goto unlock_rcu;
} elseif (!sta || event == PLINK_UNDEFINED) { /* something went wrong */ goto unlock_rcu;
}
if (event == CNF_ACPT) { /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ if (!sta->mesh->plid)
sta->mesh->plid = plid;
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