[PATCH v2 12/22] mac80211: convert S1G beacon to scan results

Thomas Pedersen
2020-08-31T20:56:33Z

This commit finds the correct offset for Information
Elements in S1G beacon frames so they can be reported in
scan results, and track whether a given BSS is S1G.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
---
net/mac80211/ieee80211_i.h | 7 +++++++
net/mac80211/rx.c | 3 ++-
net/mac80211/scan.c | 20 ++++++++++++++++----
net/mac80211/util.c | 28 ++++++++++++++++++++++++++++
4 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 9363f43887b4..8bbdc27d57c6 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -127,6 +127,9 @@ struct ieee80211_bss {

/* Keep track of what bits of information we have valid info for. */
u8 valid_data;
+
+ /* BSS info was transmitted by an S1G STA */
+ u8 s1g;
};

/**
@@ -1524,6 +1527,10 @@ struct ieee802_11_elems {
u8 dtim_count;
u8 dtim_period;
const struct ieee80211_addba_ext_ie *addba_ext_ie;
+ const struct ieee80211_s1g_cap *s1g_capab;
+ const struct ieee80211_s1g_oper_ie *s1g_oper;
+ const u8 *s1g_tsbtt;
+ const struct ieee80211_s1g_bcn_compat_ie *s1g_bcn_compat;

/* length of them, respectively */
u8 ext_capab_len;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 836cde516a18..5b92f56682e2 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4586,7 +4586,8 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
ieee80211_verify_alignment(&rx);

if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
- ieee80211_is_beacon(hdr->frame_control)))
+ ieee80211_is_beacon(hdr->frame_control) ||
+ ieee80211_is_s1g_beacon(hdr->frame_control)))
ieee80211_scan_rx(local, skb);

if (ieee80211_is_data(fc)) {
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 5002791fe165..3dd65b7c839b 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -124,6 +124,9 @@ ieee80211_update_bss_from_elems(struct ieee80211_local *local,
bss->valid_data |= IEEE80211_BSS_VALID_WMM;
}

+ if (!elems->parse_error && elems->s1g_capab)
+ bss->s1g = true;
+
if (beacon) {
struct ieee80211_supported_band *sband =
local->hw.wiphy->bands[rx_status->band];
@@ -146,7 +149,8 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_channel *channel)
{
- bool beacon = ieee80211_is_beacon(mgmt->frame_control);
+ bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
+ ieee80211_is_s1g_beacon(mgmt->frame_control);
struct cfg80211_bss *cbss, *non_tx_cbss;
struct ieee80211_bss *bss, *non_tx_bss;
struct cfg80211_inform_bss bss_meta = {
@@ -195,6 +199,11 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
elements = mgmt->u.probe_resp.variable;
baselen = offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
+ } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
+ struct ieee80211_ext *ext = (void *) mgmt;
+
+ baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
+ elements = ext->u.s1g_beacon.variable;
} else {
baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
elements = mgmt->u.beacon.variable;
@@ -246,9 +255,12 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
struct ieee80211_bss *bss;
struct ieee80211_channel *channel;

- if (skb->len < 24 ||
- (!ieee80211_is_probe_resp(mgmt->frame_control) &&
- !ieee80211_is_beacon(mgmt->frame_control)))
+ if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
+ if (skb->len < 15)
+ return;
+ } else if (skb->len < 24 ||
+ (!ieee80211_is_probe_resp(mgmt->frame_control) &&
+ !ieee80211_is_beacon(mgmt->frame_control)))
return;

sdata1 = rcu_dereference(local->scan_sdata);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 27b2f1ceca69..e474b2bf227b 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1003,6 +1003,10 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
case WLAN_EID_LINK_ID:
case WLAN_EID_BSS_MAX_IDLE_PERIOD:
case WLAN_EID_RSNX:
+ case WLAN_EID_S1G_BCN_COMPAT:
+ case WLAN_EID_S1G_CAPABILITIES:
+ case WLAN_EID_S1G_OPERATION:
+ case WLAN_EID_S1G_SHORT_BCN_INTERVAL:
/*
* not listing WLAN_EID_CHANNEL_SWITCH_WRAPPER -- it seems possible
* that if the content gets bigger it might be needed more than once
@@ -1288,6 +1292,30 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
&crc : NULL,
elem, elems);
break;
+ case WLAN_EID_S1G_CAPABILITIES:
+ if (elen == 15)
+ elems->s1g_capab = (void *)pos;
+ else
+ elem_parse_failed = true;
+ break;
+ case WLAN_EID_S1G_OPERATION:
+ if (elen == 6)
+ elems->s1g_oper = (void *)pos;
+ else
+ elem_parse_failed = true;
+ break;
+ case WLAN_EID_S1G_SHORT_BCN_INTERVAL:
+ if (elen == 2)
+ elems->s1g_tsbtt = (void *)pos;
+ else
+ elem_parse_failed = true;
+ break;
+ case WLAN_EID_S1G_BCN_COMPAT:
+ if (elen == sizeof(struct ieee80211_s1g_bcn_compat_ie))
+ elems->s1g_bcn_compat = (void *)pos;
+ else
+ elem_parse_failed = true;
+ break;
default:
break;
}
--
2.20.1