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mac80211: receive and process S1G beacons
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S1G beacons are 802.11 Extension Frames, so the fixed
header part differs from regular beacons.

Add a handler to process S1G beacons and abstract out the
fetching of BSSID and element start locations in the
beacon body handler.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200922022818.15855-14-thomas@adapt-ip.com
[don't rename, small coding style cleanups]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Thomas Pedersen authored and Johannes Berg committed Sep 28, 2020
1 parent cac8c52 commit 09a740c
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Showing 5 changed files with 159 additions and 65 deletions.
4 changes: 4 additions & 0 deletions net/mac80211/ieee80211_i.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1656,6 +1656,8 @@ int ieee80211_set_arp_filter(struct ieee80211_sub_if_data *sdata);
void ieee80211_sta_work(struct ieee80211_sub_if_data *sdata);
void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb);
void ieee80211_sta_rx_queued_ext(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb);
void ieee80211_sta_reset_beacon_monitor(struct ieee80211_sub_if_data *sdata);
void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata);
void ieee80211_mgd_stop(struct ieee80211_sub_if_data *sdata);
Expand Down Expand Up @@ -2301,6 +2303,8 @@ void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata,
const u8 *peer, u16 reason);
const char *ieee80211_get_reason_code_string(u16 reason_code);
u16 ieee80211_encode_usf(int val);
u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
enum nl80211_iftype type);

extern const struct ethtool_ops ieee80211_ethtool_ops;

Expand Down
5 changes: 5 additions & 0 deletions net/mac80211/iface.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1433,6 +1433,11 @@ static void ieee80211_iface_work(struct work_struct *work)
WARN_ON(1);
break;
}
} else if (ieee80211_is_ext(mgmt->frame_control)) {
if (sdata->vif.type == NL80211_IFTYPE_STATION)
ieee80211_sta_rx_queued_ext(sdata, skb);
else
WARN_ON(1);
} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
struct ieee80211_hdr *hdr = (void *)mgmt;
/*
Expand Down
79 changes: 62 additions & 17 deletions net/mac80211/mlme.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1602,6 +1602,9 @@ static u32 ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
int new_ap_level;
__le16 capab = mgmt->u.probe_resp.capab_info;

if (ieee80211_is_s1g_beacon(mgmt->frame_control))
return 0; /* TODO */

if (country_ie &&
(capab & cpu_to_le16(WLAN_CAPABILITY_SPECTRUM_MGMT) ||
capab & cpu_to_le16(WLAN_CAPABILITY_RADIO_MEASURE))) {
Expand Down Expand Up @@ -3896,11 +3899,12 @@ static bool ieee80211_rx_our_beacon(const u8 *tx_bssid,
}

static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_hdr *hdr, size_t len,
struct ieee80211_rx_status *rx_status)
{
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
struct ieee80211_mgmt *mgmt = (void *) hdr;
size_t baselen;
struct ieee802_11_elems elems;
struct ieee80211_local *local = sdata->local;
Expand All @@ -3910,14 +3914,24 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
u32 changed = 0;
bool erp_valid;
u8 erp_value = 0;
u32 ncrc;
u8 *bssid;
u32 ncrc = 0;
u8 *bssid, *variable = mgmt->u.beacon.variable;
u8 deauth_buf[IEEE80211_DEAUTH_FRAME_LEN];

sdata_assert_lock(sdata);

/* Process beacon from the current BSS */
baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
bssid = ieee80211_get_bssid(hdr, len, sdata->vif.type);
if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
struct ieee80211_ext *ext = (void *) mgmt;

if (ieee80211_is_s1g_short_beacon(ext->frame_control))
variable = ext->u.s1g_short_beacon.variable;
else
variable = ext->u.s1g_beacon.variable;
}

baselen = (u8 *) variable - (u8 *) mgmt;
if (baselen > len)
return;

Expand All @@ -3937,10 +3951,10 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
rcu_read_unlock();

if (ifmgd->assoc_data && ifmgd->assoc_data->need_beacon &&
ieee80211_rx_our_beacon(mgmt->bssid, ifmgd->assoc_data->bss)) {
ieee802_11_parse_elems(mgmt->u.beacon.variable,
ieee80211_rx_our_beacon(bssid, ifmgd->assoc_data->bss)) {
ieee802_11_parse_elems(variable,
len - baselen, false, &elems,
mgmt->bssid,
bssid,
ifmgd->assoc_data->bss->bssid);

ieee80211_rx_bss_info(sdata, mgmt, len, rx_status);
Expand Down Expand Up @@ -3973,7 +3987,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
}

if (!ifmgd->associated ||
!ieee80211_rx_our_beacon(mgmt->bssid, ifmgd->associated))
!ieee80211_rx_our_beacon(bssid, ifmgd->associated))
return;
bssid = ifmgd->associated->bssid;

Expand All @@ -3993,8 +4007,14 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
*/
ieee80211_sta_reset_beacon_monitor(sdata);

ncrc = crc32_be(0, (void *)&mgmt->u.beacon.beacon_int, 4);
ncrc = ieee802_11_parse_elems_crc(mgmt->u.beacon.variable,
/* TODO: CRC urrently not calculated on S1G Beacon Compatibility
* element (which carries the beacon interval). Don't forget to add a
* bit to care_about_ies[] above if mac80211 is interested in a
* changing S1G element.
*/
if (!ieee80211_is_s1g_beacon(hdr->frame_control))
ncrc = crc32_be(0, (void *)&mgmt->u.beacon.beacon_int, 4);
ncrc = ieee802_11_parse_elems_crc(variable,
len - baselen, false, &elems,
care_about_ies, ncrc,
mgmt->bssid, bssid);
Expand Down Expand Up @@ -4028,7 +4048,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
struct ieee80211_p2p_noa_attr noa = {};
int ret;

ret = cfg80211_get_p2p_attr(mgmt->u.beacon.variable,
ret = cfg80211_get_p2p_attr(variable,
len - baselen,
IEEE80211_P2P_ATTR_ABSENCE_NOTICE,
(u8 *) &noa, sizeof(noa));
Expand Down Expand Up @@ -4064,15 +4084,17 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
* the driver will use them. The synchronized view is currently
* guaranteed only in certain callbacks.
*/
if (ieee80211_hw_check(&local->hw, TIMING_BEACON_ONLY)) {
if (ieee80211_hw_check(&local->hw, TIMING_BEACON_ONLY) &&
!ieee80211_is_s1g_beacon(hdr->frame_control)) {
sdata->vif.bss_conf.sync_tsf =
le64_to_cpu(mgmt->u.beacon.timestamp);
sdata->vif.bss_conf.sync_device_ts =
rx_status->device_timestamp;
sdata->vif.bss_conf.sync_dtim_count = elems.dtim_count;
}

if (ncrc == ifmgd->beacon_crc && ifmgd->beacon_crc_valid)
if ((ncrc == ifmgd->beacon_crc && ifmgd->beacon_crc_valid) ||
ieee80211_is_s1g_short_beacon(mgmt->frame_control))
return;
ifmgd->beacon_crc = ncrc;
ifmgd->beacon_crc_valid = true;
Expand Down Expand Up @@ -4113,9 +4135,11 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
} else {
erp_valid = false;
}
changed |= ieee80211_handle_bss_capability(sdata,
le16_to_cpu(mgmt->u.beacon.capab_info),
erp_valid, erp_value);

if (!ieee80211_is_s1g_beacon(hdr->frame_control))
changed |= ieee80211_handle_bss_capability(sdata,
le16_to_cpu(mgmt->u.beacon.capab_info),
erp_valid, erp_value);

mutex_lock(&local->sta_mtx);
sta = sta_info_get(sdata, bssid);
Expand Down Expand Up @@ -4153,6 +4177,26 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
ieee80211_bss_info_change_notify(sdata, changed);
}

void ieee80211_sta_rx_queued_ext(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_rx_status *rx_status;
struct ieee80211_hdr *hdr;
u16 fc;

rx_status = (struct ieee80211_rx_status *) skb->cb;
hdr = (struct ieee80211_hdr *) skb->data;
fc = le16_to_cpu(hdr->frame_control);

sdata_lock(sdata);
switch (fc & IEEE80211_FCTL_STYPE) {
case IEEE80211_STYPE_S1G_BEACON:
ieee80211_rx_mgmt_beacon(sdata, hdr, skb->len, rx_status);
break;
}
sdata_unlock(sdata);
}

void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
Expand All @@ -4170,7 +4214,8 @@ void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,

switch (fc & IEEE80211_FCTL_STYPE) {
case IEEE80211_STYPE_BEACON:
ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, rx_status);
ieee80211_rx_mgmt_beacon(sdata, (void *)mgmt,
skb->len, rx_status);
break;
case IEEE80211_STYPE_PROBE_RESP:
ieee80211_rx_mgmt_probe_resp(sdata, skb);
Expand Down
84 changes: 36 additions & 48 deletions net/mac80211/rx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -42,51 +42,6 @@ static inline void ieee80211_rx_stats(struct net_device *dev, u32 len)
u64_stats_update_end(&tstats->syncp);
}

static u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
enum nl80211_iftype type)
{
__le16 fc = hdr->frame_control;

if (ieee80211_is_data(fc)) {
if (len < 24) /* drop incorrect hdr len (data) */
return NULL;

if (ieee80211_has_a4(fc))
return NULL;
if (ieee80211_has_tods(fc))
return hdr->addr1;
if (ieee80211_has_fromds(fc))
return hdr->addr2;

return hdr->addr3;
}

if (ieee80211_is_mgmt(fc)) {
if (len < 24) /* drop incorrect hdr len (mgmt) */
return NULL;
return hdr->addr3;
}

if (ieee80211_is_ctl(fc)) {
if (ieee80211_is_pspoll(fc))
return hdr->addr1;

if (ieee80211_is_back_req(fc)) {
switch (type) {
case NL80211_IFTYPE_STATION:
return hdr->addr2;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_AP_VLAN:
return hdr->addr1;
default:
break; /* fall through to the return */
}
}
}

return NULL;
}

/*
* monitor mode reception
*
Expand Down Expand Up @@ -1802,7 +1757,8 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
}
} else if (rx->sdata->vif.type == NL80211_IFTYPE_OCB) {
sta->rx_stats.last_rx = jiffies;
} else if (!is_multicast_ether_addr(hdr->addr1)) {
} else if (!ieee80211_is_s1g_beacon(hdr->frame_control) &&
is_multicast_ether_addr(hdr->addr1)) {
/*
* Mesh beacons will update last_rx when if they are found to
* match the current local configuration when processed.
Expand Down Expand Up @@ -1837,6 +1793,9 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
}
}

if (ieee80211_is_s1g_beacon(hdr->frame_control))
return RX_CONTINUE;

/*
* Change STA power saving mode only at the end of a frame
* exchange sequence, and only for a data or management
Expand Down Expand Up @@ -1947,6 +1906,9 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
__le16 fc;
const struct ieee80211_cipher_scheme *cs = NULL;

if (ieee80211_is_ext(hdr->frame_control))
return RX_CONTINUE;

/*
* Key selection 101
*
Expand Down Expand Up @@ -2255,7 +2217,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
hdr = (struct ieee80211_hdr *)rx->skb->data;
fc = hdr->frame_control;

if (ieee80211_is_ctl(fc))
if (ieee80211_is_ctl(fc) || ieee80211_is_ext(fc))
return RX_CONTINUE;

sc = le16_to_cpu(hdr->seq_ctrl);
Expand Down Expand Up @@ -3129,6 +3091,9 @@ ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);

if (ieee80211_is_s1g_beacon(mgmt->frame_control))
return RX_CONTINUE;

/*
* From here on, look only at management frames.
* Data and control frames are already handled,
Expand Down Expand Up @@ -3595,6 +3560,27 @@ ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
return RX_QUEUED;
}

static ieee80211_rx_result debug_noinline
ieee80211_rx_h_ext(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct ieee80211_hdr *hdr = (void *)rx->skb->data;

if (!ieee80211_is_ext(hdr->frame_control))
return RX_CONTINUE;

if (sdata->vif.type != NL80211_IFTYPE_STATION)
return RX_DROP_MONITOR;

/* for now only beacons are ext, so queue them */
skb_queue_tail(&sdata->skb_queue, rx->skb);
ieee80211_queue_work(&rx->local->hw, &sdata->work);
if (rx->sta)
rx->sta->rx_stats.packets++;

return RX_QUEUED;
}

static ieee80211_rx_result debug_noinline
ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
{
Expand Down Expand Up @@ -3814,6 +3800,7 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
CALL_RXH(ieee80211_rx_h_userspace_mgmt);
CALL_RXH(ieee80211_rx_h_action_post_userspace);
CALL_RXH(ieee80211_rx_h_action_return);
CALL_RXH(ieee80211_rx_h_ext);
CALL_RXH(ieee80211_rx_h_mgmt);

rxh_next:
Expand Down Expand Up @@ -3980,7 +3967,8 @@ static bool ieee80211_accept_frame(struct ieee80211_rx_data *rx)
struct ieee80211_hdr *hdr = (void *)skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
bool multicast = is_multicast_ether_addr(hdr->addr1);
bool multicast = is_multicast_ether_addr(hdr->addr1) ||
ieee80211_is_s1g_beacon(hdr->frame_control);

switch (sdata->vif.type) {
case NL80211_IFTYPE_STATION:
Expand Down
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