diff options
Diffstat (limited to 'net/mac80211/mesh_plink.c')
| -rw-r--r-- | net/mac80211/mesh_plink.c | 1234 |
1 files changed, 1234 insertions, 0 deletions
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c new file mode 100644 index 000000000..ee8b5013d --- /dev/null +++ b/net/mac80211/mesh_plink.c @@ -0,0 +1,1234 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2008, 2009 open80211s Ltd. + * Copyright (C) 2019 Intel Corporation + * Author: Luis Carlos Cobo <luisca@cozybit.com> + */ +#include <linux/gfp.h> +#include <linux/kernel.h> +#include <linux/random.h> +#include <linux/rculist.h> + +#include "ieee80211_i.h" +#include "rate.h" +#include "mesh.h" + +#define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) +#define PLINK_GET_LLID(p) (p + 2) +#define PLINK_GET_PLID(p) (p + 4) + +#define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ + jiffies + msecs_to_jiffies(t))) + +enum plink_event { + PLINK_UNDEFINED, + OPN_ACPT, + OPN_RJCT, + OPN_IGNR, + CNF_ACPT, + CNF_RJCT, + CNF_IGNR, + CLS_ACPT, + CLS_IGNR +}; + +static const char * const mplstates[] = { + [NL80211_PLINK_LISTEN] = "LISTEN", + [NL80211_PLINK_OPN_SNT] = "OPN-SNT", + [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", + [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", + [NL80211_PLINK_ESTAB] = "ESTAB", + [NL80211_PLINK_HOLDING] = "HOLDING", + [NL80211_PLINK_BLOCKED] = "BLOCKED" +}; + +static const char * const mplevents[] = { + [PLINK_UNDEFINED] = "NONE", + [OPN_ACPT] = "OPN_ACPT", + [OPN_RJCT] = "OPN_RJCT", + [OPN_IGNR] = "OPN_IGNR", + [CNF_ACPT] = "CNF_ACPT", + [CNF_RJCT] = "CNF_RJCT", + [CNF_IGNR] = "CNF_IGNR", + [CLS_ACPT] = "CLS_ACPT", + [CLS_IGNR] = "CLS_IGNR" +}; + +/* We only need a valid sta if user configured a minimum rssi_threshold. */ +static bool 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->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 + */ +static inline void 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 u32 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, changed = 0; + int i; + bool short_slot = false; + + sband = ieee80211_get_sband(sdata); + if (!sband) + return changed; + + if (sband->band == NL80211_BAND_5GHZ) { + /* (IEEE 802.11-2012 19.4.5) */ + short_slot = true; + goto out; + } else if (sband->band != NL80211_BAND_2GHZ) { + goto out; + } + + for (i = 0; i < sband->n_bitrates; i++) + if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) + erp_rates |= BIT(i); + + if (!erp_rates) + goto out; + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &local->sta_list, list) { + if (sdata != sta->sdata || + sta->mesh->plink_state != NL80211_PLINK_ESTAB) + continue; + + short_slot = false; + if (erp_rates & sta->sta.supp_rates[sband->band]) + short_slot = true; + else + break; + } + rcu_read_unlock(); + +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 atleast one + * HT20 peer is present. Otherwise no-protection mode is selected. + */ +static u32 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.chandef.width) { + case NL80211_CHAN_WIDTH_20_NOHT: + case NL80211_CHAN_WIDTH_5: + case NL80211_CHAN_WIDTH_10: + return 0; + default: + break; + } + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &local->sta_list, list) { + if (sdata != sta->sdata || + sta->mesh->plink_state != NL80211_PLINK_ESTAB) + continue; + + if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) + continue; + + if (!sta->sta.ht_cap.ht_supported) { + mpl_dbg(sdata, "nonHT sta (%pM) is present\n", + sta->sta.addr); + non_ht_sta = true; + break; + } + + mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); + ht20_sta = true; + } + rcu_read_unlock(); + + if (non_ht_sta) + ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; + else if (ht20_sta && + sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) + ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; + else + ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; + + if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) + return 0; + + sdata->vif.bss_conf.ht_operation_mode = ht_opmode; + sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; + mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); + return BSS_CHANGED_HT; +} + +static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta, + enum ieee80211_self_protected_actioncode action, + u8 *da, u16 llid, u16 plid, u16 reason) +{ + struct ieee80211_local *local = sdata->local; + struct sk_buff *skb; + struct ieee80211_tx_info *info; + struct ieee80211_mgmt *mgmt; + bool include_plid = false; + u16 peering_proto = 0; + u8 *pos, ie_len = 4; + u8 ie_len_he_cap; + int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); + int err = -ENOMEM; + + ie_len_he_cap = ieee80211_ie_len_he_cap(sdata, + NL80211_IFTYPE_MESH_POINT); + skb = dev_alloc_skb(local->tx_headroom + + hdr_len + + 2 + /* capability info */ + 2 + /* AID */ + 2 + 8 + /* supported rates */ + 2 + (IEEE80211_MAX_SUPP_RATES - 8) + + 2 + sdata->u.mesh.mesh_id_len + + 2 + sizeof(struct ieee80211_meshconf_ie) + + 2 + sizeof(struct ieee80211_ht_cap) + + 2 + sizeof(struct ieee80211_ht_operation) + + 2 + sizeof(struct ieee80211_vht_cap) + + 2 + sizeof(struct ieee80211_vht_operation) + + ie_len_he_cap + + 2 + 1 + sizeof(struct ieee80211_he_operation) + + sizeof(struct ieee80211_he_6ghz_oper) + + 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) + + 2 + 8 + /* peering IE */ + sdata->u.mesh.ie_len); + if (!skb) + return err; + info = IEEE80211_SKB_CB(skb); + skb_reserve(skb, local->tx_headroom); + mgmt = skb_put_zero(skb, hdr_len); + mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | + IEEE80211_STYPE_ACTION); + memcpy(mgmt->da, da, ETH_ALEN); + memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); + memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); + mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; + mgmt->u.action.u.self_prot.action_code = action; + + if (action != WLAN_SP_MESH_PEERING_CLOSE) { + struct ieee80211_supported_band *sband; + enum nl80211_band band; + + sband = ieee80211_get_sband(sdata); + if (!sband) { + err = -EINVAL; + goto free; + } + band = sband->band; + + /* capability info */ + pos = skb_put_zero(skb, 2); + if (action == WLAN_SP_MESH_PEERING_CONFIRM) { + /* AID */ + pos = skb_put(skb, 2); + put_unaligned_le16(sta->sta.aid, pos); + } + if (ieee80211_add_srates_ie(sdata, skb, true, band) || + ieee80211_add_ext_srates_ie(sdata, skb, true, band) || + mesh_add_rsn_ie(sdata, skb) || + mesh_add_meshid_ie(sdata, skb) || + mesh_add_meshconf_ie(sdata, skb)) + goto free; + } else { /* WLAN_SP_MESH_PEERING_CLOSE */ + info->flags |= IEEE80211_TX_CTL_NO_ACK; + if (mesh_add_meshid_ie(sdata, skb)) + goto free; + } + + /* Add Mesh Peering Management element */ + switch (action) { + case WLAN_SP_MESH_PEERING_OPEN: + break; + case WLAN_SP_MESH_PEERING_CONFIRM: + ie_len += 2; + include_plid = true; + break; + case WLAN_SP_MESH_PEERING_CLOSE: + if (plid) { + ie_len += 2; + include_plid = true; + } + ie_len += 2; /* reason code */ + break; + default: + err = -EINVAL; + goto free; + } + + if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) + goto free; + + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PEER_MGMT; + *pos++ = ie_len; + memcpy(pos, &peering_proto, 2); + pos += 2; + put_unaligned_le16(llid, pos); + pos += 2; + if (include_plid) { + put_unaligned_le16(plid, pos); + pos += 2; + } + if (action == WLAN_SP_MESH_PEERING_CLOSE) { + put_unaligned_le16(reason, pos); + pos += 2; + } + + if (action != WLAN_SP_MESH_PEERING_CLOSE) { + if (mesh_add_ht_cap_ie(sdata, skb) || + mesh_add_ht_oper_ie(sdata, skb) || + mesh_add_vht_cap_ie(sdata, skb) || + mesh_add_vht_oper_ie(sdata, skb) || + mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) || + mesh_add_he_oper_ie(sdata, skb) || + mesh_add_he_6ghz_cap_ie(sdata, skb)) + goto free; + } + + if (mesh_add_vendor_ies(sdata, skb)) + goto free; + + ieee80211_tx_skb(sdata, skb); + return 0; +free: + kfree_skb(skb); + return err; +} + +/** + * __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 u32 __mesh_plink_deactivate(struct sta_info *sta) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + u32 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; + + ieee80211_mps_sta_status_update(sta); + changed |= ieee80211_mps_set_sta_local_pm(sta, + NL80211_MESH_POWER_UNKNOWN); + + return changed; +} + +/** + * 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 + */ +u32 mesh_plink_deactivate(struct sta_info *sta) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + u32 changed; + + spin_lock_bh(&sta->mesh->plink_lock); + changed = __mesh_plink_deactivate(sta); + + if (!sdata->u.mesh.user_mpm) { + sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; + mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, + sta->sta.addr, sta->mesh->llid, + sta->mesh->plid, sta->mesh->reason); + } + spin_unlock_bh(&sta->mesh->plink_lock); + if (!sdata->u.mesh.user_mpm) + del_timer_sync(&sta->mesh->plink_timer); + mesh_path_flush_by_nexthop(sta); + + /* make sure no readers can access nexthop sta from here on */ + synchronize_net(); + + return changed; +} + +static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta, + struct ieee802_11_elems *elems) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_supported_band *sband; + u32 rates, basic_rates = 0, changed = 0; + enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; + + sband = ieee80211_get_sband(sdata); + if (!sband) + return; + + rates = ieee80211_sta_get_rates(sdata, elems, sband->band, + &basic_rates); + + spin_lock_bh(&sta->mesh->plink_lock); + sta->rx_stats.last_rx = jiffies; + + /* rates and capabilities don't change during peering */ + if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && + sta->mesh->processed_beacon) + goto out; + sta->mesh->processed_beacon = true; + + if (sta->sta.supp_rates[sband->band] != rates) + changed |= IEEE80211_RC_SUPP_RATES_CHANGED; + sta->sta.supp_rates[sband->band] = rates; + + if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, + elems->ht_cap_elem, sta)) + changed |= IEEE80211_RC_BW_CHANGED; + + ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, + elems->vht_cap_elem, sta); + + ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, + elems->he_cap_len, + elems->he_6ghz_capa, + sta); + + if (bw != sta->sta.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.bandwidth != IEEE80211_STA_RX_BW_20) + changed |= IEEE80211_RC_BW_CHANGED; + sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; + } + + if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) + rate_control_rate_init(sta); + else + rate_control_rate_update(local, sband, sta, changed); +out: + spin_unlock_bh(&sta->mesh->plink_lock); +} + +static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) +{ + struct sta_info *sta; + unsigned long *aid_map; + int aid; + + aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), + sizeof(*aid_map), GFP_KERNEL); + if (!aid_map) + return -ENOMEM; + + /* reserve aid 0 for mcast indication */ + __set_bit(0, aid_map); + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) + __set_bit(sta->sta.aid, aid_map); + rcu_read_unlock(); + + aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); + kfree(aid_map); + + if (aid > IEEE80211_MAX_AID) + return -ENOBUFS; + + return aid; +} + +static struct sta_info * +__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) +{ + struct sta_info *sta; + int aid; + + if (sdata->local->num_sta >= MESH_MAX_PLINKS) + return NULL; + + aid = mesh_allocate_aid(sdata); + if (aid < 0) + return NULL; + + sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); + if (!sta) + return NULL; + + sta->mesh->plink_state = NL80211_PLINK_LISTEN; + sta->sta.wme = true; + sta->sta.aid = aid; + + sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); + sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); + sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); + + return sta; +} + +static struct sta_info * +mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, + struct ieee802_11_elems *elems, + struct ieee80211_rx_status *rx_status) +{ + struct sta_info *sta = NULL; + + /* 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; + + cfg80211_notify_new_peer_candidate(sdata->dev, addr, + elems->ie_start, + elems->total_len, + sig, GFP_KERNEL); + } + } else + sta = __mesh_sta_info_alloc(sdata, addr); + + return sta; +} + +/* + * mesh_sta_info_get - return mesh sta info entry for @addr. + * + * @sdata: local meshif + * @addr: peer's address + * @elems: IEs from beacon or mesh peering frame. + * @rx_status: rx status for the frame for signal reporting + * + * Return existing or newly allocated sta_info under RCU read lock. + * (re)initialize with given IEs. + */ +static struct sta_info * +mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, + u8 *addr, struct ieee802_11_elems *elems, + struct ieee80211_rx_status *rx_status) __acquires(RCU) +{ + struct sta_info *sta = NULL; + + rcu_read_lock(); + sta = sta_info_get(sdata, addr); + if (sta) { + mesh_sta_info_init(sdata, sta, elems); + } else { + rcu_read_unlock(); + /* can't run atomic */ + sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); + if (!sta) { + rcu_read_lock(); + return NULL; + } + + mesh_sta_info_init(sdata, sta, elems); + + if (sta_info_insert_rcu(sta)) + return NULL; + } + + return sta; +} + +/* + * mesh_neighbour_update - update or initialize new mesh neighbor. + * + * @sdata: local meshif + * @addr: peer's address + * @elems: IEs from beacon or mesh peering frame + * @rx_status: rx status for the frame for signal reporting + * + * Initiates peering if appropriate. + */ +void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, + u8 *hw_addr, + struct ieee802_11_elems *elems, + struct ieee80211_rx_status *rx_status) +{ + struct sta_info *sta; + u32 changed = 0; + + sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); + if (!sta) + goto out; + + sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & + IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; + + if (mesh_peer_accepts_plinks(elems) && + sta->mesh->plink_state == NL80211_PLINK_LISTEN && + sdata->u.mesh.accepting_plinks && + sdata->u.mesh.mshcfg.auto_open_plinks && + rssi_threshold_check(sdata, sta)) + changed = mesh_plink_open(sta); + + ieee80211_mps_frame_release(sta, elems); +out: + rcu_read_unlock(); + ieee80211_mbss_info_change_notify(sdata, changed); +} + +void mesh_plink_timer(struct timer_list *t) +{ + struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); + struct sta_info *sta; + u16 reason = 0; + struct ieee80211_sub_if_data *sdata; + struct mesh_config *mshcfg; + enum ieee80211_self_protected_actioncode action = 0; + + /* + * This STA is valid because sta_info_destroy() will + * del_timer_sync() this timer after having made sure + * it cannot be readded (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; + } + + /* del_timer() 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; + + switch (sta->mesh->plink_state) { + case NL80211_PLINK_OPN_RCVD: + case NL80211_PLINK_OPN_SNT: + /* retry timer */ + if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { + u32 rand; + mpl_dbg(sta->sdata, + "Mesh plink for %pM (retry, timeout): %d %d\n", + sta->sta.addr, sta->mesh->plink_retries, + sta->mesh->plink_timeout); + get_random_bytes(&rand, sizeof(u32)); + sta->mesh->plink_timeout = sta->mesh->plink_timeout + + rand % sta->mesh->plink_timeout; + ++sta->mesh->plink_retries; + mod_plink_timer(sta, sta->mesh->plink_timeout); + action = WLAN_SP_MESH_PEERING_OPEN; + break; + } + reason = WLAN_REASON_MESH_MAX_RETRIES; + fallthrough; + case NL80211_PLINK_CNF_RCVD: + /* confirm timer */ + if (!reason) + reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; + sta->mesh->plink_state = NL80211_PLINK_HOLDING; + mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); + action = WLAN_SP_MESH_PEERING_CLOSE; + break; + case NL80211_PLINK_HOLDING: + /* holding timer */ + del_timer(&sta->mesh->plink_timer); + mesh_plink_fsm_restart(sta); + break; + default: + break; + } + spin_unlock_bh(&sta->mesh->plink_lock); + if (action) + mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, + sta->mesh->llid, sta->mesh->plid, reason); +} + +static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) +{ + sta->mesh->plink_timeout = timeout; + mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); +} + +static bool llid_in_use(struct ieee80211_sub_if_data *sdata, + u16 llid) +{ + struct ieee80211_local *local = sdata->local; + bool in_use = false; + struct sta_info *sta; + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &local->sta_list, list) { + if (sdata != sta->sdata) + continue; + + if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { + in_use = true; + break; + } + } + rcu_read_unlock(); + + return in_use; +} + +static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) +{ + u16 llid; + + do { + get_random_bytes(&llid, sizeof(llid)); + } while (llid_in_use(sdata, llid)); + + return llid; +} + +u32 mesh_plink_open(struct sta_info *sta) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + u32 changed; + + if (!test_sta_flag(sta, WLAN_STA_AUTH)) + return 0; + + spin_lock_bh(&sta->mesh->plink_lock); + sta->mesh->llid = mesh_get_new_llid(sdata); + if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && + sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { + spin_unlock_bh(&sta->mesh->plink_lock); + return 0; + } + sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; + mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); + spin_unlock_bh(&sta->mesh->plink_lock); + mpl_dbg(sdata, + "Mesh plink: starting establishment with %pM\n", + sta->sta.addr); + + /* set the non-peer mode to active during peering */ + changed = ieee80211_mps_local_status_update(sdata); + + mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, + sta->sta.addr, sta->mesh->llid, 0, 0); + return changed; +} + +u32 mesh_plink_block(struct sta_info *sta) +{ + u32 changed; + + spin_lock_bh(&sta->mesh->plink_lock); + changed = __mesh_plink_deactivate(sta); + sta->mesh->plink_state = NL80211_PLINK_BLOCKED; + spin_unlock_bh(&sta->mesh->plink_lock); + mesh_path_flush_by_nexthop(sta); + + return changed; +} + +static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta, + enum plink_event event) +{ + struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; + u16 reason = (event == CLS_ACPT) ? + WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; + + sta->mesh->reason = reason; + sta->mesh->plink_state = NL80211_PLINK_HOLDING; + mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); +} + +static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta) +{ + struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; + u32 changed = 0; + + del_timer(&sta->mesh->plink_timer); + sta->mesh->plink_state = NL80211_PLINK_ESTAB; + changed |= mesh_plink_inc_estab_count(sdata); + changed |= mesh_set_ht_prot_mode(sdata); + changed |= mesh_set_short_slot_time(sdata); + mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); + ieee80211_mps_sta_status_update(sta); + changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); + return changed; +} + +/** + * mesh_plink_fsm - step @sta MPM based on @event + * + * @sdata: interface + * @sta: mesh neighbor + * @event: peering event + * + * Return: changed MBSS flags + */ +static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta, enum plink_event event) +{ + struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; + enum ieee80211_self_protected_actioncode action = 0; + u32 changed = 0; + bool flush = false; + + 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: + del_timer(&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. + */ +static enum 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; + + matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || + mesh_matches_local(sdata, elems)); + + /* 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; + else if (!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; + else if (!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; + else if (sta->mesh->plid != plid) + event = CLS_IGNR; + else if (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; + } + +out: + return event; +} + +static void +mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + struct ieee802_11_elems *elems, + struct ieee80211_rx_status *rx_status) +{ + + struct sta_info *sta; + enum plink_event event; + enum ieee80211_self_protected_actioncode ftype; + u32 changed = 0; + u8 ie_len = elems->peering_len; + u16 plid, llid = 0; + + if (!elems->peering) { + mpl_dbg(sdata, + "Mesh plink: missing necessary peer link ie\n"); + return; + } + + if (elems->rsn_len && + sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { + mpl_dbg(sdata, + "Mesh plink: can't establish link with secure peer\n"); + return; + } + + ftype = mgmt->u.action.u.self_prot.action_code; + if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || + (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || + (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 + && ie_len != 8)) { + mpl_dbg(sdata, + "Mesh plink: incorrect plink ie length %d %d\n", + ftype, ie_len); + return; + } + + 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; + } else if (!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; + } else if (!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; + + sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); + } + + changed |= mesh_plink_fsm(sdata, sta, event); + +unlock_rcu: + rcu_read_unlock(); + + if (changed) + ieee80211_mbss_info_change_notify(sdata, changed); +} + +void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, size_t len, + struct ieee80211_rx_status *rx_status) +{ + struct ieee802_11_elems elems; + size_t baselen; + u8 *baseaddr; + + /* need action_code, aux */ + if (len < IEEE80211_MIN_ACTION_SIZE + 3) + return; + + if (sdata->u.mesh.user_mpm) + /* userspace must register for these */ + return; + + if (is_multicast_ether_addr(mgmt->da)) { + mpl_dbg(sdata, + "Mesh plink: ignore frame from multicast address\n"); + return; + } + + baseaddr = mgmt->u.action.u.self_prot.variable; + baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; + if (mgmt->u.action.u.self_prot.action_code == + WLAN_SP_MESH_PEERING_CONFIRM) { + baseaddr += 4; + baselen += 4; + + if (baselen > len) + return; + } + ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems, + mgmt->bssid, NULL); + mesh_process_plink_frame(sdata, mgmt, &elems, rx_status); +} |