Skip to content

Commit

Permalink
mac80211: Implement HT mixed protection mode
Browse files Browse the repository at this point in the history 
Section 9.23.3.5 of IEEE 80211s standard describes the protection rules for
HT mesh STA in a MBSS. Three HT protection modes are supported for now:

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.
no-protection mode - is selected otherwise.

This is a limited implementation of 9.23.3.5, which only considers mesh peers
when determining the HT protection mode. Station's channel_type needs to be
maintained.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Reviewed-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
  • Loading branch information
@ashokrajnagarajan @linvjw
ashokrajnagarajan authored and linvjw committed May 9, 2012
1 parent 431e315 commit 57aac7c
Show file tree
Hide file tree
Showing 2 changed files with 77 additions and 7 deletions.
83 changes: 76 additions & 7 deletions net/mac80211/mesh_plink.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,66 @@ static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
return sta;
}

/** mesh_set_ht_prot_mode - set correct HT protection mode
*
* Section 9.23.3.5 of IEEE 80211s standard 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;
u32 changed = 0;
u16 ht_opmode;
bool non_ht_sta = false, ht20_sta = false;

if (local->_oper_channel_type == NL80211_CHAN_NO_HT)
return 0;

rcu_read_lock();
list_for_each_entry_rcu(sta, &local->sta_list, list) {
if (sdata == sta->sdata &&
sta->plink_state == NL80211_PLINK_ESTAB) {
switch (sta->ch_type) {
case NL80211_CHAN_NO_HT:
mpl_dbg("mesh_plink %pM: nonHT sta (%pM) is present",
sdata->vif.addr, sta->sta.addr);
non_ht_sta = true;
goto out;
case NL80211_CHAN_HT20:
mpl_dbg("mesh_plink %pM: HT20 sta (%pM) is present",
sdata->vif.addr, sta->sta.addr);
ht20_sta = true;
default:
break;
}
}
}
out:
rcu_read_unlock();

if (non_ht_sta)
ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
else if (ht20_sta && local->_oper_channel_type > NL80211_CHAN_HT20)
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) {
sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
changed = BSS_CHANGED_HT;
mpl_dbg("mesh_plink %pM: protection mode changed to %d",
sdata->vif.addr, ht_opmode);
}

return changed;
}

/**
* __mesh_plink_deactivate - deactivate mesh peer link
*
Expand Down Expand Up @@ -302,11 +362,14 @@ static struct sta_info *mesh_peer_init(struct ieee80211_sub_if_data *sdata,
else
memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));

if (elems->ht_operation)
if (elems->ht_operation) {
if (!(elems->ht_operation->ht_param &
IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
sta->sta.ht_cap.cap &=
~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
sta->ch_type =
ieee80211_ht_oper_to_channel_type(elems->ht_operation);
}

rate_control_rate_init(sta);
spin_unlock_bh(&sta->lock);
Expand Down Expand Up @@ -495,9 +558,10 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
enum plink_event event;
enum ieee80211_self_protected_actioncode ftype;
size_t baselen;
bool deactivated, matches_local = true;
bool matches_local = true;
u8 ie_len;
u8 *baseaddr;
u32 changed = 0;
__le16 plid, llid, reason;
#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
static const char *mplstates[] = {
Expand Down Expand Up @@ -783,7 +847,8 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
sta->plink_state = NL80211_PLINK_ESTAB;
spin_unlock_bh(&sta->lock);
mesh_plink_inc_estab_count(sdata);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
changed |= mesh_set_ht_prot_mode(sdata);
changed |= BSS_CHANGED_BEACON;
mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
sta->sta.addr);
break;
Expand Down Expand Up @@ -818,7 +883,8 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
sta->plink_state = NL80211_PLINK_ESTAB;
spin_unlock_bh(&sta->lock);
mesh_plink_inc_estab_count(sdata);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
changed |= mesh_set_ht_prot_mode(sdata);
changed |= BSS_CHANGED_BEACON;
mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
sta->sta.addr);
mesh_plink_frame_tx(sdata,
Expand All @@ -836,13 +902,13 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
case CLS_ACPT:
reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
sta->reason = reason;
deactivated = __mesh_plink_deactivate(sta);
__mesh_plink_deactivate(sta);
sta->plink_state = NL80211_PLINK_HOLDING;
llid = sta->llid;
mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
spin_unlock_bh(&sta->lock);
if (deactivated)
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
changed |= mesh_set_ht_prot_mode(sdata);
changed |= BSS_CHANGED_BEACON;
mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
sta->sta.addr, llid, plid, reason);
break;
Expand Down Expand Up @@ -889,4 +955,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
}

rcu_read_unlock();

if (changed)
ieee80211_bss_info_change_notify(sdata, changed);
}
1 change: 1 addition & 0 deletions net/mac80211/sta_info.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -362,6 +362,7 @@ struct sta_info {
struct timer_list plink_timer;
s64 t_offset;
s64 t_offset_setpoint;
enum nl80211_channel_type ch_type;
#endif

#ifdef CONFIG_MAC80211_DEBUGFS
Expand Down

0 comments on commit 57aac7c

Please sign in to comment.