linux/net/mac80211/mesh_plink.c
Nishikawa, Kenzoh 2ae70efcea mac80211: keep sending peer candidate events while in listen state
Instead of sending peer candidate events just once, send them as long
as the peer remains in the LISTEN state in the peering state machine,
when userspace is implementing the peering manager.
Userspace may silence the events from a peer by progressing the state
machine or by setting the link state to BLOCKED.

Fixes the problem that a mesh peering process won't be fired again after
the previous first peering trial fails due to like air propagation error
if the peering is managed by user space such as wpa_supplicant.

This patch works with another patch for wpa_supplicant described here
which fires a peering process again triggered by the notice from kernel.
http://lists.shmoo.com/pipermail/hostap/2014-November/031235.html

Signed-off-by: Kenzoh Nishikawa <Kenzoh.Nishikawa@jp.sony.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-12-17 11:49:24 +01:00

1130 lines
29 KiB
C

/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Author: Luis Carlos Cobo <luisca@cozybit.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
#define PLINK_GET_LLID(p) (p + 2)
#define PLINK_GET_PLID(p) (p + 4)
#define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
jiffies + HZ * t / 1000))
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"
};
static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
enum ieee80211_self_protected_actioncode action,
u8 *da, u16 llid, u16 plid, u16 reason);
/* 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_read(&sta->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->lock
*/
static inline void mesh_plink_fsm_restart(struct sta_info *sta)
{
sta->plink_state = NL80211_PLINK_LISTEN;
sta->llid = sta->plid = sta->reason = 0;
sta->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;
enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
struct sta_info *sta;
u32 erp_rates = 0, changed = 0;
int i;
bool short_slot = false;
if (band == IEEE80211_BAND_5GHZ) {
/* (IEEE 802.11-2012 19.4.5) */
short_slot = true;
goto out;
} else if (band != IEEE80211_BAND_2GHZ ||
(band == IEEE80211_BAND_2GHZ &&
local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
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->plink_state != NL80211_PLINK_ESTAB)
continue;
short_slot = false;
if (erp_rates & sta->sta.supp_rates[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
*
* 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->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;
}
/**
* __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.
*
* Locking: the caller must hold sta->lock
*/
static u32 __mesh_plink_deactivate(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
u32 changed = 0;
if (sta->plink_state == NL80211_PLINK_ESTAB)
changed = mesh_plink_dec_estab_count(sdata);
sta->plink_state = NL80211_PLINK_BLOCKED;
mesh_path_flush_by_nexthop(sta);
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->lock);
changed = __mesh_plink_deactivate(sta);
sta->reason = WLAN_REASON_MESH_PEER_CANCELED;
mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
sta->sta.addr, sta->llid, sta->plid,
sta->reason);
spin_unlock_bh(&sta->lock);
return changed;
}
static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
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;
int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
sizeof(mgmt->u.action.u.self_prot);
int err = -ENOMEM;
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 + 8 + /* peering IE */
sdata->u.mesh.ie_len);
if (!skb)
return err;
info = IEEE80211_SKB_CB(skb);
skb_reserve(skb, local->tx_headroom);
mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
memset(mgmt, 0, 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) {
enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
/* capability info */
pos = skb_put(skb, 2);
memset(pos, 0, 2);
if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
/* AID */
pos = skb_put(skb, 2);
put_unaligned_le16(plid, pos + 2);
}
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))
goto free;
}
if (mesh_add_vendor_ies(sdata, skb))
goto free;
ieee80211_tx_skb(sdata, skb);
return 0;
free:
kfree_skb(skb);
return err;
}
static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
struct ieee802_11_elems *elems, bool insert)
{
struct ieee80211_local *local = sdata->local;
enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
struct ieee80211_supported_band *sband;
u32 rates, basic_rates = 0, changed = 0;
sband = local->hw.wiphy->bands[band];
rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
spin_lock_bh(&sta->lock);
sta->last_rx = jiffies;
/* rates and capabilities don't change during peering */
if (sta->plink_state == NL80211_PLINK_ESTAB)
goto out;
if (sta->sta.supp_rates[band] != rates)
changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
sta->sta.supp_rates[band] = rates;
if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
elems->ht_cap_elem, sta))
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 (insert)
rate_control_rate_init(sta);
else
rate_control_rate_update(local, sband, sta, changed);
out:
spin_unlock_bh(&sta->lock);
}
static struct sta_info *
__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
{
struct sta_info *sta;
if (sdata->local->num_sta >= MESH_MAX_PLINKS)
return NULL;
sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
if (!sta)
return NULL;
sta->plink_state = NL80211_PLINK_LISTEN;
sta->sta.wme = true;
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 sta_info *sta = NULL;
/* Userspace handles station allocation */
if (sdata->u.mesh.user_mpm ||
sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
cfg80211_notify_new_peer_candidate(sdata->dev, addr,
elems->ie_start,
elems->total_len,
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.
*
* 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) __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, false);
} else {
rcu_read_unlock();
/* can't run atomic */
sta = mesh_sta_info_alloc(sdata, addr, elems);
if (!sta) {
rcu_read_lock();
return NULL;
}
mesh_sta_info_init(sdata, sta, elems, true);
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
*
* Initiates peering if appropriate.
*/
void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
u8 *hw_addr,
struct ieee802_11_elems *elems)
{
struct sta_info *sta;
u32 changed = 0;
sta = mesh_sta_info_get(sdata, hw_addr, elems);
if (!sta)
goto out;
if (mesh_peer_accepts_plinks(elems) &&
sta->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);
else if (sta->plink_state == NL80211_PLINK_LISTEN &&
(sdata->u.mesh.user_mpm ||
sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED))
cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
elems->ie_start,
elems->total_len,
GFP_ATOMIC);
ieee80211_mps_frame_release(sta, elems);
out:
rcu_read_unlock();
ieee80211_mbss_info_change_notify(sdata, changed);
}
static void mesh_plink_timer(unsigned long data)
{
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 = (struct sta_info *) data;
if (sta->sdata->local->quiescing)
return;
spin_lock_bh(&sta->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->plink_timer.expires)) {
mpl_dbg(sta->sdata,
"Ignoring timer for %pM in state %s (timer adjusted)",
sta->sta.addr, mplstates[sta->plink_state]);
spin_unlock_bh(&sta->lock);
return;
}
/* del_timer() and handler may race when entering these states */
if (sta->plink_state == NL80211_PLINK_LISTEN ||
sta->plink_state == NL80211_PLINK_ESTAB) {
mpl_dbg(sta->sdata,
"Ignoring timer for %pM in state %s (timer deleted)",
sta->sta.addr, mplstates[sta->plink_state]);
spin_unlock_bh(&sta->lock);
return;
}
mpl_dbg(sta->sdata,
"Mesh plink timer for %pM fired on state %s\n",
sta->sta.addr, mplstates[sta->plink_state]);
sdata = sta->sdata;
mshcfg = &sdata->u.mesh.mshcfg;
switch (sta->plink_state) {
case NL80211_PLINK_OPN_RCVD:
case NL80211_PLINK_OPN_SNT:
/* retry timer */
if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
u32 rand;
mpl_dbg(sta->sdata,
"Mesh plink for %pM (retry, timeout): %d %d\n",
sta->sta.addr, sta->plink_retries,
sta->plink_timeout);
get_random_bytes(&rand, sizeof(u32));
sta->plink_timeout = sta->plink_timeout +
rand % sta->plink_timeout;
++sta->plink_retries;
mod_plink_timer(sta, sta->plink_timeout);
action = WLAN_SP_MESH_PEERING_OPEN;
break;
}
reason = WLAN_REASON_MESH_MAX_RETRIES;
/* fall through on else */
case NL80211_PLINK_CNF_RCVD:
/* confirm timer */
if (!reason)
reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
sta->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->plink_timer);
mesh_plink_fsm_restart(sta);
break;
default:
break;
}
spin_unlock_bh(&sta->lock);
if (action)
mesh_plink_frame_tx(sdata, action, sta->sta.addr,
sta->llid, sta->plid, reason);
}
static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
{
sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
sta->plink_timer.data = (unsigned long) sta;
sta->plink_timer.function = mesh_plink_timer;
sta->plink_timeout = timeout;
add_timer(&sta->plink_timer);
}
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 (!memcmp(&sta->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));
/* for mesh PS we still only have the AID range for TIM bits */
llid = (llid % IEEE80211_MAX_AID) + 1;
} 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->lock);
sta->llid = mesh_get_new_llid(sdata);
if (sta->plink_state != NL80211_PLINK_LISTEN &&
sta->plink_state != NL80211_PLINK_BLOCKED) {
spin_unlock_bh(&sta->lock);
return 0;
}
sta->plink_state = NL80211_PLINK_OPN_SNT;
mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
spin_unlock_bh(&sta->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, WLAN_SP_MESH_PEERING_OPEN,
sta->sta.addr, sta->llid, 0, 0);
return changed;
}
u32 mesh_plink_block(struct sta_info *sta)
{
u32 changed;
spin_lock_bh(&sta->lock);
changed = __mesh_plink_deactivate(sta);
sta->plink_state = NL80211_PLINK_BLOCKED;
spin_unlock_bh(&sta->lock);
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->reason = reason;
sta->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->plink_timer);
sta->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;
mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
mplstates[sta->plink_state], mplevents[event]);
spin_lock_bh(&sta->lock);
switch (sta->plink_state) {
case NL80211_PLINK_LISTEN:
switch (event) {
case CLS_ACPT:
mesh_plink_fsm_restart(sta);
break;
case OPN_ACPT:
sta->plink_state = NL80211_PLINK_OPN_RCVD;
sta->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->plink_state = NL80211_PLINK_OPN_RCVD;
action = WLAN_SP_MESH_PEERING_CONFIRM;
break;
case CNF_ACPT:
sta->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;
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->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->lock);
if (action) {
mesh_plink_frame_tx(sdata, action, sta->sta.addr,
sta->llid, sta->plid, sta->reason);
/* also send confirm in open case */
if (action == WLAN_SP_MESH_PEERING_OPEN) {
mesh_plink_frame_tx(sdata,
WLAN_SP_MESH_PEERING_CONFIRM,
sta->sta.addr, sta->llid,
sta->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;
}
} 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->plink_state == NL80211_PLINK_BLOCKED)
goto out;
}
/* new matching peer */
if (!sta) {
event = OPN_ACPT;
goto out;
}
switch (ftype) {
case WLAN_SP_MESH_PEERING_OPEN:
if (!matches_local)
event = OPN_RJCT;
if (!mesh_plink_free_count(sdata) ||
(sta->plid && sta->plid != plid))
event = OPN_IGNR;
else
event = OPN_ACPT;
break;
case WLAN_SP_MESH_PEERING_CONFIRM:
if (!matches_local)
event = CNF_RJCT;
if (!mesh_plink_free_count(sdata) ||
sta->llid != llid ||
(sta->plid && sta->plid != plid))
event = CNF_IGNR;
else
event = CNF_ACPT;
break;
case WLAN_SP_MESH_PEERING_CLOSE:
if (sta->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->plid != plid)
event = CLS_IGNR;
else if (ie_len == 8 && sta->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 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);
if (!sta) {
mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
goto unlock_rcu;
}
sta->plid = plid;
} else if (!sta && event == OPN_RJCT) {
mesh_plink_frame_tx(sdata, 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;
}
/* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
if (!sta->plid && event == CNF_ACPT)
sta->plid = plid;
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;
}
ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
mesh_process_plink_frame(sdata, mgmt, &elems);
}