[deliverable/linux.git] / net / mac80211 / mesh_sync.c

/*
 * Copyright 2011-2012, Pavel Zubarev <pavel.zubarev@gmail.com>
 * Copyright 2011-2012, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
 * Copyright 2011-2012, cozybit Inc.
 *
 * 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 "ieee80211_i.h"
#include "mesh.h"
#include "driver-ops.h"

/* This is not in the standard.  It represents a tolerable tbtt drift below
 * which we do no TSF adjustment.
 */
#define TOFFSET_MINIMUM_ADJUSTMENT 10

/* This is not in the standard. It is a margin added to the
 * Toffset setpoint to mitigate TSF overcorrection
 * introduced by TSF adjustment latency.
 */
#define TOFFSET_SET_MARGIN 20

/* This is not in the standard.  It represents the maximum Toffset jump above
 * which we'll invalidate the Toffset setpoint and choose a new setpoint.  This
 * could be, for instance, in case a neighbor is restarted and its TSF counter
 * reset.
 */
#define TOFFSET_MAXIMUM_ADJUSTMENT 30000		/* 30 ms */

struct sync_method {
	u8 method;
	struct ieee80211_mesh_sync_ops ops;
};

/**
 * mesh_peer_tbtt_adjusting - check if an mp is currently adjusting its TBTT
 *
 * @ie: information elements of a management frame from the mesh peer
 */
static bool mesh_peer_tbtt_adjusting(struct ieee802_11_elems *ie)
{
	return (ie->mesh_config->meshconf_cap &
	    MESHCONF_CAPAB_TBTT_ADJUSTING) != 0;
}

void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	/* sdata->vif.bss_conf.beacon_int in 1024us units, 0.04% */
	u64 beacon_int_fraction = sdata->vif.bss_conf.beacon_int * 1024 / 2500;
	u64 tsf;
	u64 tsfdelta;

	spin_lock_bh(&ifmsh->sync_offset_lock);
	if (ifmsh->sync_offset_clockdrift_max < beacon_int_fraction) {
		msync_dbg(sdata, "TBTT : max clockdrift=%lld; adjusting\n",
			  (long long) ifmsh->sync_offset_clockdrift_max);
		tsfdelta = -ifmsh->sync_offset_clockdrift_max;
		ifmsh->sync_offset_clockdrift_max = 0;
	} else {
		msync_dbg(sdata, "TBTT : max clockdrift=%lld; adjusting by %llu\n",
			  (long long) ifmsh->sync_offset_clockdrift_max,
			  (unsigned long long) beacon_int_fraction);
		tsfdelta = -beacon_int_fraction;
		ifmsh->sync_offset_clockdrift_max -= beacon_int_fraction;
	}
	spin_unlock_bh(&ifmsh->sync_offset_lock);

	tsf = drv_get_tsf(local, sdata);
	if (tsf != -1ULL)
		drv_set_tsf(local, sdata, tsf + tsfdelta);
}

static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
				   u16 stype,
				   struct ieee80211_mgmt *mgmt,
				   struct ieee802_11_elems *elems,
				   struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	u64 t_t, t_r;

	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);

	/* standard mentions only beacons */
	if (stype != IEEE80211_STYPE_BEACON)
		return;

	/* The current tsf is a first approximation for the timestamp
	 * for the received beacon.  Further down we try to get a
	 * better value from the rx_status->mactime field if
	 * available. Also we have to call drv_get_tsf() before
	 * entering the rcu-read section.*/
	t_r = drv_get_tsf(local, sdata);

	rcu_read_lock();
	sta = sta_info_get(sdata, mgmt->sa);
	if (!sta)
		goto no_sync;

	/* check offset sync conditions (13.13.2.2.1)
	 *
	 * TODO also sync to
	 * dot11MeshNbrOffsetMaxNeighbor non-peer non-MBSS neighbors
	 */

	if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) {
		clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
		msync_dbg(sdata, "STA %pM : is adjusting TBTT\n", sta->sta.addr);
		goto no_sync;
	}

	if (rx_status->flag & RX_FLAG_MACTIME_MPDU && rx_status->mactime) {
		/*
		 * The mactime is defined as the time the first data symbol
		 * of the frame hits the PHY, and the timestamp of the beacon
		 * is defined as "the time that the data symbol containing the
		 * first bit of the timestamp is transmitted to the PHY plus
		 * the transmitting STA's delays through its local PHY from the
		 * MAC-PHY interface to its interface with the WM" (802.11
		 * 11.1.2)
		 *
		 * T_r, in 13.13.2.2.2, is just defined as "the frame reception
		 * time" but we unless we interpret that time to be the same
		 * time of the beacon timestamp, the offset calculation will be
		 * off.  Below we adjust t_r to be "the time at which the first
		 * symbol of the timestamp element in the beacon is received".
		 * This correction depends on the rate.
		 *
		 * Based on similar code in ibss.c
		 */
		int rate;

		if (rx_status->flag & RX_FLAG_HT) {
			/* TODO:
			 * In principle there could be HT-beacons (Dual Beacon
			 * HT Operation options), but for now ignore them and
			 * just use the primary (i.e. non-HT) beacons for
			 * synchronization.
			 * */
			goto no_sync;
		} else
			rate = local->hw.wiphy->bands[rx_status->band]->
				bitrates[rx_status->rate_idx].bitrate;

		/* 24 bytes of header * 8 bits/byte *
		 * 10*(100 Kbps)/Mbps / rate (100 Kbps)*/
		t_r = rx_status->mactime + (24 * 8 * 10 / rate);
	}

	/* Timing offset calculation (see 13.13.2.2.2) */
	t_t = le64_to_cpu(mgmt->u.beacon.timestamp);
	sta->t_offset = t_t - t_r;

	if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
		s64 t_clockdrift = sta->t_offset_setpoint
				   - sta->t_offset;
		msync_dbg(sdata,
			  "STA %pM : sta->t_offset=%lld, sta->t_offset_setpoint=%lld, t_clockdrift=%lld\n",
			  sta->sta.addr,
			  (long long) sta->t_offset,
			  (long long)
			  sta->t_offset_setpoint,
			  (long long) t_clockdrift);

		if (t_clockdrift > TOFFSET_MAXIMUM_ADJUSTMENT ||
			t_clockdrift < -TOFFSET_MAXIMUM_ADJUSTMENT) {
			msync_dbg(sdata,
				  "STA %pM : t_clockdrift=%lld too large, setpoint reset\n",
				  sta->sta.addr,
				  (long long) t_clockdrift);
			clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
			goto no_sync;
		}

		rcu_read_unlock();

		spin_lock_bh(&ifmsh->sync_offset_lock);
		if (t_clockdrift >
		    ifmsh->sync_offset_clockdrift_max)
			ifmsh->sync_offset_clockdrift_max
				= t_clockdrift;
		spin_unlock_bh(&ifmsh->sync_offset_lock);

	} else {
		sta->t_offset_setpoint = sta->t_offset - TOFFSET_SET_MARGIN;
		set_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
		msync_dbg(sdata,
			  "STA %pM : offset was invalid, sta->t_offset=%lld\n",
			  sta->sta.addr,
			  (long long) sta->t_offset);
		rcu_read_unlock();
	}
	return;

no_sync:
	rcu_read_unlock();
}

static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	WARN_ON(ifmsh->mesh_sp_id
		!= IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
	BUG_ON(!rcu_read_lock_held());

	spin_lock_bh(&ifmsh->sync_offset_lock);

	if (ifmsh->sync_offset_clockdrift_max >
		TOFFSET_MINIMUM_ADJUSTMENT) {
		/* Since ajusting the tsf here would
		 * require a possibly blocking call
		 * to the driver tsf setter, we punt
		 * the tsf adjustment to the mesh tasklet
		 */
		msync_dbg(sdata,
			  "TBTT : kicking off TBTT adjustment with clockdrift_max=%lld\n",
			  ifmsh->sync_offset_clockdrift_max);
		set_bit(MESH_WORK_DRIFT_ADJUST,
			&ifmsh->wrkq_flags);
	} else {
		msync_dbg(sdata,
			  "TBTT : max clockdrift=%lld; too small to adjust\n",
			  (long long)ifmsh->sync_offset_clockdrift_max);
		ifmsh->sync_offset_clockdrift_max = 0;
	}
	spin_unlock_bh(&ifmsh->sync_offset_lock);
}

static const u8 *mesh_get_vendor_oui(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 offset;

	if (!ifmsh->ie || !ifmsh->ie_len)
		return NULL;

	offset = ieee80211_ie_split_vendor(ifmsh->ie,
					ifmsh->ie_len, 0);

	if (!offset)
		return NULL;

	return ifmsh->ie + offset + 2;
}

static void mesh_sync_vendor_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
				   u16 stype,
				   struct ieee80211_mgmt *mgmt,
				   struct ieee802_11_elems *elems,
				   struct ieee80211_rx_status *rx_status)
{
	const u8 *oui;

	WARN_ON(sdata->u.mesh.mesh_sp_id != IEEE80211_SYNC_METHOD_VENDOR);
	msync_dbg(sdata, "called mesh_sync_vendor_rx_bcn_presp\n");
	oui = mesh_get_vendor_oui(sdata);
	/*  here you would implement the vendor offset tracking for this oui */
}

static void mesh_sync_vendor_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
{
	const u8 *oui;

	WARN_ON(sdata->u.mesh.mesh_sp_id != IEEE80211_SYNC_METHOD_VENDOR);
	msync_dbg(sdata, "called mesh_sync_vendor_adjust_tbtt\n");
	oui = mesh_get_vendor_oui(sdata);
	/*  here you would implement the vendor tsf adjustment for this oui */
}

/* global variable */
static struct sync_method sync_methods[] = {
	{
		.method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
		.ops = {
			.rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp,
			.adjust_tbtt = &mesh_sync_offset_adjust_tbtt,
		}
	},
	{
		.method = IEEE80211_SYNC_METHOD_VENDOR,
		.ops = {
			.rx_bcn_presp = &mesh_sync_vendor_rx_bcn_presp,
			.adjust_tbtt = &mesh_sync_vendor_adjust_tbtt,
		}
	},
};

struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method)
{
	struct ieee80211_mesh_sync_ops *ops = NULL;
	u8 i;

	for (i = 0 ; i < ARRAY_SIZE(sync_methods); ++i) {
		if (sync_methods[i].method == method) {
			ops = &sync_methods[i].ops;
			break;
		}
	}
	return ops;
}
Commit	Line	Data
dbf498fb JC	1	/*
	2	* Copyright 2011-2012, Pavel Zubarev <pavel.zubarev@gmail.com>
	3	* Copyright 2011-2012, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
	4	* Copyright 2011-2012, cozybit Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include "ieee80211_i.h"
	12	#include "mesh.h"
	13	#include "driver-ops.h"
	14
dbf498fb JC	15	/* This is not in the standard. It represents a tolerable tbtt drift below
	16	* which we do no TSF adjustment.
	17	*/
a802a6eb JC	18	#define TOFFSET_MINIMUM_ADJUSTMENT 10
a802a6eb JC	19
ec14bcd2 JC	20	/* This is not in the standard. It is a margin added to the
	21	* Toffset setpoint to mitigate TSF overcorrection
	22	* introduced by TSF adjustment latency.
	23	*/
	24	#define TOFFSET_SET_MARGIN 20
	25
a802a6eb JC	26	/* This is not in the standard. It represents the maximum Toffset jump above
	27	* which we'll invalidate the Toffset setpoint and choose a new setpoint. This
	28	* could be, for instance, in case a neighbor is restarted and its TSF counter
	29	* reset.
ec14bcd2	30	*/
a802a6eb	31	#define TOFFSET_MAXIMUM_ADJUSTMENT 30000 /* 30 ms */
dbf498fb JC	32
	33	struct sync_method {
	34	u8 method;
	35	struct ieee80211_mesh_sync_ops ops;
	36	};
	37
	38	/**
	39	* mesh_peer_tbtt_adjusting - check if an mp is currently adjusting its TBTT
	40	*
	41	* @ie: information elements of a management frame from the mesh peer
	42	*/
	43	static bool mesh_peer_tbtt_adjusting(struct ieee802_11_elems *ie)
	44	{
	45	return (ie->mesh_config->meshconf_cap &
	46	MESHCONF_CAPAB_TBTT_ADJUSTING) != 0;
	47	}
	48
	49	void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
	50	{
	51	struct ieee80211_local *local = sdata->local;
	52	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	53	/* sdata->vif.bss_conf.beacon_int in 1024us units, 0.04% */
	54	u64 beacon_int_fraction = sdata->vif.bss_conf.beacon_int * 1024 / 2500;
	55	u64 tsf;
	56	u64 tsfdelta;
	57
	58	spin_lock_bh(&ifmsh->sync_offset_lock);
dbf498fb	59	if (ifmsh->sync_offset_clockdrift_max < beacon_int_fraction) {
bdcbd8e0 JB	60	msync_dbg(sdata, "TBTT : max clockdrift=%lld; adjusting\n",
bdcbd8e0 JB	61	(long long) ifmsh->sync_offset_clockdrift_max);
dbf498fb JC	62	tsfdelta = -ifmsh->sync_offset_clockdrift_max;
	63	ifmsh->sync_offset_clockdrift_max = 0;
	64	} else {
bdcbd8e0 JB	65	msync_dbg(sdata, "TBTT : max clockdrift=%lld; adjusting by %llu\n",
	66	(long long) ifmsh->sync_offset_clockdrift_max,
	67	(unsigned long long) beacon_int_fraction);
dbf498fb JC	68	tsfdelta = -beacon_int_fraction;
	69	ifmsh->sync_offset_clockdrift_max -= beacon_int_fraction;
	70	}
55fabefe	71	spin_unlock_bh(&ifmsh->sync_offset_lock);
dbf498fb JC	72
	73	tsf = drv_get_tsf(local, sdata);
	74	if (tsf != -1ULL)
	75	drv_set_tsf(local, sdata, tsf + tsfdelta);
dbf498fb JC	76	}
	77
	78	static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
	79	u16 stype,
	80	struct ieee80211_mgmt *mgmt,
	81	struct ieee802_11_elems *elems,
	82	struct ieee80211_rx_status *rx_status)
	83	{
	84	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	85	struct ieee80211_local *local = sdata->local;
	86	struct sta_info *sta;
	87	u64 t_t, t_r;
	88
	89	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
	90
	91	/* standard mentions only beacons */
	92	if (stype != IEEE80211_STYPE_BEACON)
	93	return;
	94
	95	/* The current tsf is a first approximation for the timestamp
	96	* for the received beacon. Further down we try to get a
	97	* better value from the rx_status->mactime field if
	98	* available. Also we have to call drv_get_tsf() before
	99	* entering the rcu-read section.*/
	100	t_r = drv_get_tsf(local, sdata);
	101
	102	rcu_read_lock();
	103	sta = sta_info_get(sdata, mgmt->sa);
	104	if (!sta)
	105	goto no_sync;
	106
	107	/* check offset sync conditions (13.13.2.2.1)
	108	*
	109	* TODO also sync to
	110	* dot11MeshNbrOffsetMaxNeighbor non-peer non-MBSS neighbors
	111	*/
	112
	113	if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) {
	114	clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
bdcbd8e0	115	msync_dbg(sdata, "STA %pM : is adjusting TBTT\n", sta->sta.addr);
dbf498fb JC	116	goto no_sync;
	117	}
	118
	119	if (rx_status->flag & RX_FLAG_MACTIME_MPDU && rx_status->mactime) {
	120	/*
	121	* The mactime is defined as the time the first data symbol
	122	* of the frame hits the PHY, and the timestamp of the beacon
	123	* is defined as "the time that the data symbol containing the
	124	* first bit of the timestamp is transmitted to the PHY plus
	125	* the transmitting STA's delays through its local PHY from the
	126	* MAC-PHY interface to its interface with the WM" (802.11
	127	* 11.1.2)
	128	*
	129	* T_r, in 13.13.2.2.2, is just defined as "the frame reception
	130	* time" but we unless we interpret that time to be the same
	131	* time of the beacon timestamp, the offset calculation will be
	132	* off. Below we adjust t_r to be "the time at which the first
	133	* symbol of the timestamp element in the beacon is received".
	134	* This correction depends on the rate.
	135	*
	136	* Based on similar code in ibss.c
	137	*/
	138	int rate;
	139
	140	if (rx_status->flag & RX_FLAG_HT) {
	141	/* TODO:
	142	* In principle there could be HT-beacons (Dual Beacon
	143	* HT Operation options), but for now ignore them and
	144	* just use the primary (i.e. non-HT) beacons for
	145	* synchronization.
	146	* */
	147	goto no_sync;
	148	} else
	149	rate = local->hw.wiphy->bands[rx_status->band]->
	150	bitrates[rx_status->rate_idx].bitrate;
	151
	152	/* 24 bytes of header * 8 bits/byte *
	153	* 10(100 Kbps)/Mbps / rate (100 Kbps)/
	154	t_r = rx_status->mactime + (24 * 8 * 10 / rate);
	155	}
	156
	157	/* Timing offset calculation (see 13.13.2.2.2) */
	158	t_t = le64_to_cpu(mgmt->u.beacon.timestamp);
	159	sta->t_offset = t_t - t_r;
	160
	161	if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
	162	s64 t_clockdrift = sta->t_offset_setpoint
	163	- sta->t_offset;
bdcbd8e0 JB	164	msync_dbg(sdata,
bdcbd8e0 JB	165	"STA %pM : sta->t_offset=%lld, sta->t_offset_setpoint=%lld, t_clockdrift=%lld\n",
dbf498fb JC	166	sta->sta.addr,
	167	(long long) sta->t_offset,
	168	(long long)
	169	sta->t_offset_setpoint,
	170	(long long) t_clockdrift);
a802a6eb JC	171
	172	if (t_clockdrift > TOFFSET_MAXIMUM_ADJUSTMENT \|\|
	173	t_clockdrift < -TOFFSET_MAXIMUM_ADJUSTMENT) {
bdcbd8e0 JB	174	msync_dbg(sdata,
bdcbd8e0 JB	175	"STA %pM : t_clockdrift=%lld too large, setpoint reset\n",
a802a6eb JC	176	sta->sta.addr,
	177	(long long) t_clockdrift);
	178	clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
	179	goto no_sync;
	180	}
	181
dbf498fb JC	182	rcu_read_unlock();
	183
	184	spin_lock_bh(&ifmsh->sync_offset_lock);
	185	if (t_clockdrift >
	186	ifmsh->sync_offset_clockdrift_max)
	187	ifmsh->sync_offset_clockdrift_max
	188	= t_clockdrift;
	189	spin_unlock_bh(&ifmsh->sync_offset_lock);
	190
	191	} else {
6ac95b57	192	sta->t_offset_setpoint = sta->t_offset - TOFFSET_SET_MARGIN;
dbf498fb	193	set_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
bdcbd8e0 JB	194	msync_dbg(sdata,
bdcbd8e0 JB	195	"STA %pM : offset was invalid, sta->t_offset=%lld\n",
dbf498fb JC	196	sta->sta.addr,
	197	(long long) sta->t_offset);
	198	rcu_read_unlock();
	199	}
	200	return;
	201
	202	no_sync:
	203	rcu_read_unlock();
	204	}
	205
	206	static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
	207	{
	208	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	209
	210	WARN_ON(ifmsh->mesh_sp_id
	211	!= IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
	212	BUG_ON(!rcu_read_lock_held());
	213
	214	spin_lock_bh(&ifmsh->sync_offset_lock);
	215
	216	if (ifmsh->sync_offset_clockdrift_max >
a802a6eb	217	TOFFSET_MINIMUM_ADJUSTMENT) {
dbf498fb JC	218	/* Since ajusting the tsf here would
	219	* require a possibly blocking call
	220	* to the driver tsf setter, we punt
	221	* the tsf adjustment to the mesh tasklet
	222	*/
bdcbd8e0 JB	223	msync_dbg(sdata,
	224	"TBTT : kicking off TBTT adjustment with clockdrift_max=%lld\n",
	225	ifmsh->sync_offset_clockdrift_max);
dbf498fb JC	226	set_bit(MESH_WORK_DRIFT_ADJUST,
	227	&ifmsh->wrkq_flags);
	228	} else {
bdcbd8e0 JB	229	msync_dbg(sdata,
	230	"TBTT : max clockdrift=%lld; too small to adjust\n",
	231	(long long)ifmsh->sync_offset_clockdrift_max);
dbf498fb JC	232	ifmsh->sync_offset_clockdrift_max = 0;
	233	}
	234	spin_unlock_bh(&ifmsh->sync_offset_lock);
	235	}
	236
	237	static const u8 mesh_get_vendor_oui(struct ieee80211_sub_if_data sdata)
	238	{
	239	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	240	u8 offset;
	241
	242	if (!ifmsh->ie \|\| !ifmsh->ie_len)
	243	return NULL;
	244
	245	offset = ieee80211_ie_split_vendor(ifmsh->ie,
	246	ifmsh->ie_len, 0);
	247
	248	if (!offset)
	249	return NULL;
	250
	251	return ifmsh->ie + offset + 2;
	252	}
	253
	254	static void mesh_sync_vendor_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
	255	u16 stype,
	256	struct ieee80211_mgmt *mgmt,
	257	struct ieee802_11_elems *elems,
	258	struct ieee80211_rx_status *rx_status)
	259	{
	260	const u8 *oui;
	261
	262	WARN_ON(sdata->u.mesh.mesh_sp_id != IEEE80211_SYNC_METHOD_VENDOR);
bdcbd8e0	263	msync_dbg(sdata, "called mesh_sync_vendor_rx_bcn_presp\n");
dbf498fb JC	264	oui = mesh_get_vendor_oui(sdata);
	265	/* here you would implement the vendor offset tracking for this oui */
	266	}
	267
	268	static void mesh_sync_vendor_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
	269	{
	270	const u8 *oui;
	271
	272	WARN_ON(sdata->u.mesh.mesh_sp_id != IEEE80211_SYNC_METHOD_VENDOR);
bdcbd8e0	273	msync_dbg(sdata, "called mesh_sync_vendor_adjust_tbtt\n");
dbf498fb JC	274	oui = mesh_get_vendor_oui(sdata);
	275	/* here you would implement the vendor tsf adjustment for this oui */
	276	}
	277
	278	/* global variable */
	279	static struct sync_method sync_methods[] = {
	280	{
	281	.method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
	282	.ops = {
	283	.rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp,
	284	.adjust_tbtt = &mesh_sync_offset_adjust_tbtt,
	285	}
	286	},
	287	{
	288	.method = IEEE80211_SYNC_METHOD_VENDOR,
	289	.ops = {
	290	.rx_bcn_presp = &mesh_sync_vendor_rx_bcn_presp,
	291	.adjust_tbtt = &mesh_sync_vendor_adjust_tbtt,
	292	}
	293	},
	294	};
	295
	296	struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method)
	297	{
	298	struct ieee80211_mesh_sync_ops *ops = NULL;
	299	u8 i;
	300
	301	for (i = 0 ; i < ARRAY_SIZE(sync_methods); ++i) {
	302	if (sync_methods[i].method == method) {
	303	ops = &sync_methods[i].ops;
	304	break;
	305	}
	306	}
	307	return ops;
	308	}