void mesh_sync_adjust_tsf(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, "TSF : 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, "TSF : 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);
if (local->ops->offset_tsf) {
drv_offset_tsf(local, sdata, tsfdelta);
} else {
tsf = drv_get_tsf(local, sdata);
if (tsf != -1ULL)
drv_set_tsf(local, sdata, tsf + tsfdelta);
}
}
/* IBSS attributes */
static ssize_t ieee80211_if_fmt_tsf(
const struct ieee80211_sub_if_data *sdata, char *buf, int buflen)
{
struct ieee80211_local *local = sdata->local;
u64 tsf;
tsf = drv_get_tsf(local, (struct ieee80211_sub_if_data *)sdata);
return scnprintf(buf, buflen, "0x%016llx\n", (unsigned long long) tsf);
}
static ssize_t tsf_read(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct ieee80211_local *local = file->private_data;
u64 tsf;
tsf = drv_get_tsf(local);
return mac80211_format_buffer(user_buf, count, ppos, "0x%016llx\n",
(unsigned long long) tsf);
}
static ssize_t ieee80211_if_parse_tsf(
struct ieee80211_sub_if_data *sdata, const char *buf, int buflen)
{
struct ieee80211_local *local = sdata->local;
unsigned long long tsf;
int ret;
int tsf_is_delta = 0;
if (strncmp(buf, "reset", 5) == 0) {
if (local->ops->reset_tsf) {
drv_reset_tsf(local, sdata);
wiphy_info(local->hw.wiphy, "debugfs reset TSF\n");
}
} else {
if (buflen > 10 && buf[1] == '=') {
if (buf[0] == '+')
tsf_is_delta = 1;
else if (buf[0] == '-')
tsf_is_delta = -1;
else
return -EINVAL;
buf += 2;
}
ret = kstrtoull(buf, 10, &tsf);
if (ret < 0)
return ret;
if (tsf_is_delta)
tsf = drv_get_tsf(local, sdata) + tsf_is_delta * tsf;
if (local->ops->set_tsf) {
drv_set_tsf(local, sdata, tsf);
wiphy_info(local->hw.wiphy,
"debugfs set TSF to %#018llx\n", tsf);
}
}
ieee80211_recalc_dtim(local, sdata);
return buflen;
}
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;
/*
* Get time when timestamp field was received. If we don't
* have rx timestamps, then use current tsf as an approximation.
* drv_get_tsf() must be called before entering the rcu-read
* section.
*/
if (ieee80211_have_rx_timestamp(rx_status))
t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
24 + 12 +
elems->total_len +
FCS_LEN,
24);
else
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)) {
msync_dbg(sdata, "STA %pM : is adjusting TBTT\n",
sta->sta.addr);
goto no_sync;
}
/* Timing offset calculation (see 13.13.2.2.2) */
t_t = le64_to_cpu(mgmt->u.beacon.timestamp);
sta->mesh->t_offset = t_t - t_r;
if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
s64 t_clockdrift = sta->mesh->t_offset_setpoint - sta->mesh->t_offset;
msync_dbg(sdata,
"STA %pM : t_offset=%lld, t_offset_setpoint=%lld, t_clockdrift=%lld\n",
sta->sta.addr, (long long) sta->mesh->t_offset,
(long long) sta->mesh->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;
}
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->mesh->t_offset_setpoint = sta->mesh->t_offset - TOFFSET_SET_MARGIN;
set_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
msync_dbg(sdata,
"STA %pM : offset was invalid, t_offset=%lld\n",
sta->sta.addr,
(long long) sta->mesh->t_offset);
}
no_sync:
rcu_read_unlock();
}
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems,
bool beacon)
{
struct ieee80211_local *local = sdata->local;
int freq;
struct cfg80211_bss *cbss;
struct ieee80211_bss *bss;
struct sta_info *sta;
struct ieee80211_channel *channel;
u64 beacon_timestamp, rx_timestamp;
u32 supp_rates = 0;
enum ieee80211_band band = rx_status->band;
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
bool rates_updated = false;
if (elems->ds_params && elems->ds_params_len == 1)
freq = ieee80211_channel_to_frequency(elems->ds_params[0],
band);
else
freq = rx_status->freq;
channel = ieee80211_get_channel(local->hw.wiphy, freq);
if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
return;
if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (elems->supp_rates) {
supp_rates = ieee80211_sta_get_rates(local, elems,
band);
if (sta) {
u32 prev_rates;
prev_rates = sta->sta.supp_rates[band];
/* make sure mandatory rates are always added */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);
if (sta->sta.supp_rates[band] != prev_rates) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
printk(KERN_DEBUG
"%s: updated supp_rates set "
"for %pM based on beacon"
"/probe_resp (0x%x -> 0x%x)\n",
sdata->name, sta->sta.addr,
prev_rates,
sta->sta.supp_rates[band]);
#endif
rates_updated = true;
}
} else {
rcu_read_unlock();
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
mgmt->sa, supp_rates);
}
}
if (sta && elems->wmm_info)
set_sta_flag(sta, WLAN_STA_WME);
if (sta && elems->ht_info_elem && elems->ht_cap_elem &&
sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
/* we both use HT */
struct ieee80211_sta_ht_cap sta_ht_cap_new;
enum nl80211_channel_type channel_type =
ieee80211_ht_info_to_channel_type(
elems->ht_info_elem);
ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
elems->ht_cap_elem,
&sta_ht_cap_new);
/*
* fall back to HT20 if we don't use or use
* the other extension channel
*/
if ((channel_type == NL80211_CHAN_HT40MINUS ||
channel_type == NL80211_CHAN_HT40PLUS) &&
channel_type != sdata->u.ibss.channel_type)
sta_ht_cap_new.cap &=
~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
sizeof(sta_ht_cap_new))) {
memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
sizeof(sta_ht_cap_new));
rates_updated = true;
}
}
if (sta && rates_updated)
rate_control_rate_init(sta);
rcu_read_unlock();
}
bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
channel, beacon);
if (!bss)
return;
cbss = container_of((void *)bss, struct cfg80211_bss, priv);
/* was just updated in ieee80211_bss_info_update */
beacon_timestamp = cbss->tsf;
/* check if we need to merge IBSS */
/* we use a fixed BSSID */
if (sdata->u.ibss.fixed_bssid)
goto put_bss;
/* not an IBSS */
if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
goto put_bss;
/* different channel */
if (cbss->channel != local->oper_channel)
goto put_bss;
/* different SSID */
if (elems->ssid_len != sdata->u.ibss.ssid_len ||
memcmp(elems->ssid, sdata->u.ibss.ssid,
sdata->u.ibss.ssid_len))
goto put_bss;
/* same BSSID */
if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
goto put_bss;
if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
/*
* For correct IBSS merging we need mactime; since 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)
* - equals the time this bit arrives at the receiver - we have
* to take into account the offset between the two.
*
* E.g. at 1 MBit that means mactime is 192 usec earlier
* (=24 bytes * 8 usecs/byte) than the beacon timestamp.
*/
int rate;
if (rx_status->flag & RX_FLAG_HT)
rate = 65; /* TODO: HT rates */
else
rate = local->hw.wiphy->bands[band]->
bitrates[rx_status->rate_idx].bitrate;
rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
} else {
/*
* second best option: get current TSF
* (will return -1 if not supported)
*/
rx_timestamp = drv_get_tsf(local, sdata);
}
#ifdef CONFIG_MAC80211_IBSS_DEBUG
printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
"%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
mgmt->sa, mgmt->bssid,
(unsigned long long)rx_timestamp,
(unsigned long long)beacon_timestamp,
(unsigned long long)(rx_timestamp - beacon_timestamp),
jiffies);
#endif
if (beacon_timestamp > rx_timestamp) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
printk(KERN_DEBUG "%s: beacon TSF higher than "
"local TSF - IBSS merge with BSSID %pM\n",
sdata->name, mgmt->bssid);
#endif
ieee80211_sta_join_ibss(sdata, bss);
supp_rates = ieee80211_sta_get_rates(local, elems, band);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
supp_rates);
rcu_read_unlock();
}
put_bss:
ieee80211_rx_bss_put(local, bss);
}