mac80211: introduce TDLS channel switch ops
Implement the cfg80211 TDLS channel switch ops and introduce new mac80211
ones for low-level drivers.
Verify low-level driver support for the new ops when using the relevant
wiphy feature bit. Also verify the peer supports channel switching before
passing the command down.
Add a new STA flag to track the off-channel state with the TDLS peer and
make sure to cancel the channel-switch if the peer STA is unexpectedly
removed.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index fa141ae..358f9a4 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -449,6 +449,48 @@
ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
}
+static void
+ieee80211_tdls_add_chan_switch_req_ies(struct ieee80211_sub_if_data *sdata,
+ struct sk_buff *skb, const u8 *peer,
+ bool initiator, const u8 *extra_ies,
+ size_t extra_ies_len, u8 oper_class,
+ struct cfg80211_chan_def *chandef)
+{
+ struct ieee80211_tdls_data *tf;
+ size_t offset = 0, noffset;
+ u8 *pos;
+
+ if (WARN_ON_ONCE(!chandef))
+ return;
+
+ tf = (void *)skb->data;
+ tf->u.chan_switch_req.target_channel =
+ ieee80211_frequency_to_channel(chandef->chan->center_freq);
+ tf->u.chan_switch_req.oper_class = oper_class;
+
+ if (extra_ies_len) {
+ static const u8 before_lnkie[] = {
+ WLAN_EID_SECONDARY_CHANNEL_OFFSET,
+ };
+ noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
+ before_lnkie,
+ ARRAY_SIZE(before_lnkie),
+ offset);
+ pos = skb_put(skb, noffset - offset);
+ memcpy(pos, extra_ies + offset, noffset - offset);
+ offset = noffset;
+ }
+
+ ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
+
+ /* add any remaining IEs */
+ if (extra_ies_len) {
+ noffset = extra_ies_len;
+ pos = skb_put(skb, noffset - offset);
+ memcpy(pos, extra_ies + offset, noffset - offset);
+ }
+}
+
static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb, const u8 *peer,
u8 action_code, u16 status_code,
@@ -481,6 +523,12 @@
if (status_code == 0 || action_code == WLAN_TDLS_TEARDOWN)
ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
break;
+ case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
+ ieee80211_tdls_add_chan_switch_req_ies(sdata, skb, peer,
+ initiator, extra_ies,
+ extra_ies_len,
+ oper_class, chandef);
+ break;
}
}
@@ -547,6 +595,12 @@
skb_put(skb, sizeof(tf->u.discover_req));
tf->u.discover_req.dialog_token = dialog_token;
break;
+ case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
+ tf->category = WLAN_CATEGORY_TDLS;
+ tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST;
+
+ skb_put(skb, sizeof(tf->u.chan_switch_req));
+ break;
default:
return -EINVAL;
}
@@ -626,6 +680,7 @@
case WLAN_TDLS_SETUP_CONFIRM:
case WLAN_TDLS_TEARDOWN:
case WLAN_TDLS_DISCOVERY_REQUEST:
+ case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
ret = ieee80211_prep_tdls_encap_data(local->hw.wiphy,
sdata->dev, peer,
action_code, dialog_token,
@@ -699,6 +754,7 @@
initiator = false;
break;
case WLAN_TDLS_TEARDOWN:
+ case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
/* any value is ok */
break;
default:
@@ -1046,3 +1102,181 @@
cfg80211_tdls_oper_request(sdata->dev, peer, oper, reason_code, gfp);
}
EXPORT_SYMBOL(ieee80211_tdls_oper_request);
+
+static void
+iee80211_tdls_add_ch_switch_timing(u8 *buf, u16 switch_time, u16 switch_timeout)
+{
+ struct ieee80211_ch_switch_timing *ch_sw;
+
+ *buf++ = WLAN_EID_CHAN_SWITCH_TIMING;
+ *buf++ = sizeof(struct ieee80211_ch_switch_timing);
+
+ ch_sw = (void *)buf;
+ ch_sw->switch_time = cpu_to_le16(switch_time);
+ ch_sw->switch_timeout = cpu_to_le16(switch_timeout);
+}
+
+/* find switch timing IE in SKB ready for Tx */
+static const u8 *ieee80211_tdls_find_sw_timing_ie(struct sk_buff *skb)
+{
+ struct ieee80211_tdls_data *tf;
+ const u8 *ie_start;
+
+ /*
+ * Get the offset for the new location of the switch timing IE.
+ * The SKB network header will now point to the "payload_type"
+ * element of the TDLS data frame struct.
+ */
+ tf = container_of(skb->data + skb_network_offset(skb),
+ struct ieee80211_tdls_data, payload_type);
+ ie_start = tf->u.chan_switch_req.variable;
+ return cfg80211_find_ie(WLAN_EID_CHAN_SWITCH_TIMING, ie_start,
+ skb->len - (ie_start - skb->data));
+}
+
+static struct sk_buff *
+ieee80211_tdls_ch_sw_tmpl_get(struct sta_info *sta, u8 oper_class,
+ struct cfg80211_chan_def *chandef,
+ u32 *ch_sw_tm_ie_offset)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ u8 extra_ies[2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
+ 2 + sizeof(struct ieee80211_ch_switch_timing)];
+ int extra_ies_len = 2 + sizeof(struct ieee80211_ch_switch_timing);
+ u8 *pos = extra_ies;
+ struct sk_buff *skb;
+
+ /*
+ * if chandef points to a wide channel add a Secondary-Channel
+ * Offset information element
+ */
+ if (chandef->width == NL80211_CHAN_WIDTH_40) {
+ struct ieee80211_sec_chan_offs_ie *sec_chan_ie;
+ bool ht40plus;
+
+ *pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
+ *pos++ = sizeof(*sec_chan_ie);
+ sec_chan_ie = (void *)pos;
+
+ ht40plus = cfg80211_get_chandef_type(chandef) ==
+ NL80211_CHAN_HT40PLUS;
+ sec_chan_ie->sec_chan_offs = ht40plus ?
+ IEEE80211_HT_PARAM_CHA_SEC_ABOVE :
+ IEEE80211_HT_PARAM_CHA_SEC_BELOW;
+ pos += sizeof(*sec_chan_ie);
+
+ extra_ies_len += 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
+ }
+
+ /* just set the values to 0, this is a template */
+ iee80211_tdls_add_ch_switch_timing(pos, 0, 0);
+
+ skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr,
+ WLAN_TDLS_CHANNEL_SWITCH_REQUEST,
+ 0, 0, !sta->sta.tdls_initiator,
+ extra_ies, extra_ies_len,
+ oper_class, chandef);
+ if (!skb)
+ return NULL;
+
+ skb = ieee80211_build_data_template(sdata, skb, 0);
+ if (IS_ERR(skb)) {
+ tdls_dbg(sdata, "Failed building TDLS channel switch frame\n");
+ return NULL;
+ }
+
+ if (ch_sw_tm_ie_offset) {
+ const u8 *tm_ie = ieee80211_tdls_find_sw_timing_ie(skb);
+
+ if (!tm_ie) {
+ tdls_dbg(sdata, "No switch timing IE in TDLS switch\n");
+ dev_kfree_skb_any(skb);
+ return NULL;
+ }
+
+ *ch_sw_tm_ie_offset = tm_ie - skb->data;
+ }
+
+ tdls_dbg(sdata,
+ "TDLS channel switch request template for %pM ch %d width %d\n",
+ sta->sta.addr, chandef->chan->center_freq, chandef->width);
+ return skb;
+}
+
+int
+ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev,
+ const u8 *addr, u8 oper_class,
+ struct cfg80211_chan_def *chandef)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
+ struct sk_buff *skb = NULL;
+ u32 ch_sw_tm_ie;
+ int ret;
+
+ mutex_lock(&local->sta_mtx);
+ sta = sta_info_get(sdata, addr);
+ if (!sta) {
+ tdls_dbg(sdata,
+ "Invalid TDLS peer %pM for channel switch request\n",
+ addr);
+ ret = -ENOENT;
+ goto out;
+ }
+
+ if (!test_sta_flag(sta, WLAN_STA_TDLS_CHAN_SWITCH)) {
+ tdls_dbg(sdata, "TDLS channel switch unsupported by %pM\n",
+ addr);
+ ret = -ENOTSUPP;
+ goto out;
+ }
+
+ skb = ieee80211_tdls_ch_sw_tmpl_get(sta, oper_class, chandef,
+ &ch_sw_tm_ie);
+ if (!skb) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = drv_tdls_channel_switch(local, sdata, &sta->sta, oper_class,
+ chandef, skb, ch_sw_tm_ie);
+ if (!ret)
+ set_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
+
+out:
+ mutex_unlock(&local->sta_mtx);
+ dev_kfree_skb_any(skb);
+ return ret;
+}
+
+void
+ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy,
+ struct net_device *dev,
+ const u8 *addr)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
+
+ mutex_lock(&local->sta_mtx);
+ sta = sta_info_get(sdata, addr);
+ if (!sta) {
+ tdls_dbg(sdata,
+ "Invalid TDLS peer %pM for channel switch cancel\n",
+ addr);
+ goto out;
+ }
+
+ if (!test_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL)) {
+ tdls_dbg(sdata, "TDLS channel switch not initiated by %pM\n",
+ addr);
+ goto out;
+ }
+
+ drv_tdls_cancel_channel_switch(local, sdata, &sta->sta);
+ clear_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
+
+out:
+ mutex_unlock(&local->sta_mtx);
+}