From 8a4d32f30d11d6d8cc29594c7a36b9be6b0edbb5 Mon Sep 17 00:00:00 2001 From: Arik Nemtsov Date: Sun, 9 Nov 2014 18:50:20 +0200 Subject: [PATCH] mac80211: add TDLS channel-switch Rx flow When receiving a TDLS channel switch request or response, parse the frame and call a new tdls_recv_channel_switch op in the low level driver with the parsed data. Signed-off-by: Arik Nemtsov Signed-off-by: Arik Nemtsov Signed-off-by: Johannes Berg --- include/net/mac80211.h | 37 ++++- net/mac80211/driver-ops.h | 12 ++ net/mac80211/ieee80211_i.h | 3 + net/mac80211/iface.c | 2 + net/mac80211/main.c | 3 +- net/mac80211/rx.c | 21 +++ net/mac80211/tdls.c | 328 +++++++++++++++++++++++++++++++++++++ net/mac80211/trace.h | 45 +++++ 8 files changed, 449 insertions(+), 2 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index fdedceb7adcb..56b7e2114728 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1826,6 +1826,31 @@ struct ieee80211_scan_request { struct cfg80211_scan_request req; }; +/** + * struct ieee80211_tdls_ch_sw_params - TDLS channel switch parameters + * + * @sta: peer this TDLS channel-switch request/response came from + * @chandef: channel referenced in a TDLS channel-switch request + * @action_code: see &enum ieee80211_tdls_actioncode + * @status: channel-switch response status + * @timestamp: time at which the frame was received + * @switch_time: switch-timing parameter received in the frame + * @switch_timeout: switch-timing parameter received in the frame + * @tmpl_skb: TDLS switch-channel response template + * @ch_sw_tm_ie: offset of the channel-switch timing IE inside @tmpl_skb + */ +struct ieee80211_tdls_ch_sw_params { + struct ieee80211_sta *sta; + struct cfg80211_chan_def *chandef; + u8 action_code; + u32 status; + u32 timestamp; + u16 switch_time; + u16 switch_timeout; + struct sk_buff *tmpl_skb; + u32 ch_sw_tm_ie; +}; + /** * wiphy_to_ieee80211_hw - return a mac80211 driver hw struct from a wiphy * @@ -2925,6 +2950,13 @@ enum ieee80211_reconfig_type { * optionally copy the skb for further re-use. * @tdls_cancel_channel_switch: Stop channel-switching with a TDLS peer. Both * peers must be on the base channel when the call completes. + * @tdls_recv_channel_switch: a TDLS channel-switch related frame (request or + * response) has been received from a remote peer. The driver gets + * parameters parsed from the incoming frame and may use them to continue + * an ongoing channel-switch operation. In addition, a channel-switch + * response template is provided, together with the location of the + * switch-timing IE within the template. The skb can only be used within + * the function call. */ struct ieee80211_ops { void (*tx)(struct ieee80211_hw *hw, @@ -3141,10 +3173,13 @@ struct ieee80211_ops { struct ieee80211_vif *vif, struct ieee80211_sta *sta, u8 oper_class, struct cfg80211_chan_def *chandef, - struct sk_buff *skb, u32 ch_sw_tm_ie); + struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie); void (*tdls_cancel_channel_switch)(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct ieee80211_sta *sta); + void (*tdls_recv_channel_switch)(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_tdls_ch_sw_params *params); }; /** diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index ec4ae42ac15f..ba0d2cb5df12 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -1337,4 +1337,16 @@ drv_tdls_cancel_channel_switch(struct ieee80211_local *local, trace_drv_return_void(local); } +static inline void +drv_tdls_recv_channel_switch(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_tdls_ch_sw_params *params) +{ + trace_drv_tdls_recv_channel_switch(local, sdata, params); + if (local->ops->tdls_recv_channel_switch) + local->ops->tdls_recv_channel_switch(&local->hw, &sdata->vif, + params); + trace_drv_return_void(local); +} + #endif /* __MAC80211_DRIVER_OPS */ diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 2c7abc077b6b..5de2e5f3a57e 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -993,6 +993,7 @@ enum sdata_queue_type { IEEE80211_SDATA_QUEUE_AGG_STOP = 2, IEEE80211_SDATA_QUEUE_RX_AGG_START = 3, IEEE80211_SDATA_QUEUE_RX_AGG_STOP = 4, + IEEE80211_SDATA_QUEUE_TDLS_CHSW = 5, }; enum { @@ -2013,6 +2014,8 @@ int ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev, void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, struct net_device *dev, const u8 *addr); +void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb); extern const struct ethtool_ops ieee80211_ethtool_ops; diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 6b631c049eba..82473d909bb6 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1202,6 +1202,8 @@ static void ieee80211_iface_work(struct work_struct *work) WLAN_BACK_RECIPIENT, 0, false); mutex_unlock(&local->sta_mtx); + } else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_TDLS_CHSW) { + ieee80211_process_tdls_channel_switch(sdata, skb); } else if (ieee80211_is_action(mgmt->frame_control) && mgmt->u.action.category == WLAN_CATEGORY_BACK) { int len = skb->len; diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 774ccb2d9a76..6ab99da38db9 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -766,7 +766,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) if ((hw->wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) && (!local->ops->tdls_channel_switch || - !local->ops->tdls_cancel_channel_switch)) + !local->ops->tdls_cancel_channel_switch || + !local->ops->tdls_recv_channel_switch)) return -EOPNOTSUPP; #ifdef CONFIG_PM diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 0f4297e2aae2..d9bbb73d4436 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2333,6 +2333,27 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx) if (!ieee80211_frame_allowed(rx, fc)) return RX_DROP_MONITOR; + /* directly handle TDLS channel switch requests/responses */ + if (unlikely(((struct ethhdr *)rx->skb->data)->h_proto == + cpu_to_be16(ETH_P_TDLS))) { + struct ieee80211_tdls_data *tf = (void *)rx->skb->data; + + if (pskb_may_pull(rx->skb, + offsetof(struct ieee80211_tdls_data, u)) && + tf->payload_type == WLAN_TDLS_SNAP_RFTYPE && + tf->category == WLAN_CATEGORY_TDLS && + (tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST || + tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE)) { + rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TDLS_CHSW; + skb_queue_tail(&sdata->skb_queue, rx->skb); + ieee80211_queue_work(&rx->local->hw, &sdata->work); + if (rx->sta) + rx->sta->rx_packets++; + + return RX_QUEUED; + } + } + if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && unlikely(port_control) && sdata->bss) { sdata = container_of(sdata->bss, struct ieee80211_sub_if_data, diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c index 358f9a4512ad..55ddd77b865d 100644 --- a/net/mac80211/tdls.c +++ b/net/mac80211/tdls.c @@ -491,6 +491,20 @@ ieee80211_tdls_add_chan_switch_req_ies(struct ieee80211_sub_if_data *sdata, } } +static void +ieee80211_tdls_add_chan_switch_resp_ies(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb, const u8 *peer, + u16 status_code, bool initiator, + const u8 *extra_ies, + size_t extra_ies_len) +{ + if (status_code == 0) + ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator); + + if (extra_ies_len) + memcpy(skb_put(skb, extra_ies_len), extra_ies, extra_ies_len); +} + 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, @@ -529,6 +543,12 @@ static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata, extra_ies_len, oper_class, chandef); break; + case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE: + ieee80211_tdls_add_chan_switch_resp_ies(sdata, skb, peer, + status_code, + initiator, extra_ies, + extra_ies_len); + break; } } @@ -601,6 +621,13 @@ ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev, skb_put(skb, sizeof(tf->u.chan_switch_req)); break; + case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE: + tf->category = WLAN_CATEGORY_TDLS; + tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE; + + skb_put(skb, sizeof(tf->u.chan_switch_resp)); + tf->u.chan_switch_resp.status_code = cpu_to_le16(status_code); + break; default: return -EINVAL; } @@ -681,6 +708,7 @@ ieee80211_tdls_build_mgmt_packet_data(struct ieee80211_sub_if_data *sdata, case WLAN_TDLS_TEARDOWN: case WLAN_TDLS_DISCOVERY_REQUEST: case WLAN_TDLS_CHANNEL_SWITCH_REQUEST: + case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE: ret = ieee80211_prep_tdls_encap_data(local->hw.wiphy, sdata->dev, peer, action_code, dialog_token, @@ -755,6 +783,7 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev, break; case WLAN_TDLS_TEARDOWN: case WLAN_TDLS_CHANNEL_SWITCH_REQUEST: + case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE: /* any value is ok */ break; default: @@ -1280,3 +1309,302 @@ ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, out: mutex_unlock(&local->sta_mtx); } + +static struct sk_buff * +ieee80211_tdls_ch_sw_resp_tmpl_get(struct sta_info *sta, + u32 *ch_sw_tm_ie_offset) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + struct sk_buff *skb; + u8 extra_ies[2 + sizeof(struct ieee80211_ch_switch_timing)]; + + /* initial timing are always zero in the template */ + iee80211_tdls_add_ch_switch_timing(extra_ies, 0, 0); + + skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr, + WLAN_TDLS_CHANNEL_SWITCH_RESPONSE, + 0, 0, !sta->sta.tdls_initiator, + extra_ies, sizeof(extra_ies), 0, NULL); + if (!skb) + return NULL; + + skb = ieee80211_build_data_template(sdata, skb, 0); + if (IS_ERR(skb)) { + tdls_dbg(sdata, + "Failed building TDLS channel switch resp 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 resp\n"); + dev_kfree_skb_any(skb); + return NULL; + } + + *ch_sw_tm_ie_offset = tm_ie - skb->data; + } + + tdls_dbg(sdata, "TDLS get channel switch response template for %pM\n", + sta->sta.addr); + return skb; +} + +static int +ieee80211_process_tdls_channel_switch_resp(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_local *local = sdata->local; + struct ieee802_11_elems elems; + struct sta_info *sta; + struct ieee80211_tdls_data *tf = (void *)skb->data; + bool local_initiator; + struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); + int baselen = offsetof(typeof(*tf), u.chan_switch_resp.variable); + struct ieee80211_tdls_ch_sw_params params = {}; + int ret; + + params.action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE; + params.timestamp = rx_status->device_timestamp; + + if (skb->len < baselen) { + tdls_dbg(sdata, "TDLS channel switch resp too short: %d\n", + skb->len); + return -EINVAL; + } + + mutex_lock(&local->sta_mtx); + sta = sta_info_get(sdata, tf->sa); + if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) { + tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM\n", + tf->sa); + ret = -EINVAL; + goto out; + } + + params.sta = &sta->sta; + params.status = le16_to_cpu(tf->u.chan_switch_resp.status_code); + if (params.status != 0) { + ret = 0; + goto call_drv; + } + + ieee802_11_parse_elems(tf->u.chan_switch_resp.variable, + skb->len - baselen, false, &elems); + if (elems.parse_error) { + tdls_dbg(sdata, "Invalid IEs in TDLS channel switch resp\n"); + ret = -EINVAL; + goto out; + } + + if (!elems.ch_sw_timing || !elems.lnk_id) { + tdls_dbg(sdata, "TDLS channel switch resp - missing IEs\n"); + ret = -EINVAL; + goto out; + } + + /* validate the initiator is set correctly */ + local_initiator = + !memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN); + if (local_initiator == sta->sta.tdls_initiator) { + tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator\n"); + ret = -EINVAL; + goto out; + } + + params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time); + params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout); + + params.tmpl_skb = + ieee80211_tdls_ch_sw_resp_tmpl_get(sta, ¶ms.ch_sw_tm_ie); + if (!params.tmpl_skb) { + ret = -ENOENT; + goto out; + } + +call_drv: + drv_tdls_recv_channel_switch(sdata->local, sdata, ¶ms); + + tdls_dbg(sdata, + "TDLS channel switch response received from %pM status %d\n", + tf->sa, params.status); + +out: + mutex_unlock(&local->sta_mtx); + dev_kfree_skb_any(params.tmpl_skb); + return ret; +} + +static int +ieee80211_process_tdls_channel_switch_req(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_local *local = sdata->local; + struct ieee802_11_elems elems; + struct cfg80211_chan_def chandef; + struct ieee80211_channel *chan; + enum nl80211_channel_type chan_type; + int freq; + u8 target_channel, oper_class; + bool local_initiator; + struct sta_info *sta; + enum ieee80211_band band; + struct ieee80211_tdls_data *tf = (void *)skb->data; + struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); + int baselen = offsetof(typeof(*tf), u.chan_switch_req.variable); + struct ieee80211_tdls_ch_sw_params params = {}; + int ret = 0; + + params.action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST; + params.timestamp = rx_status->device_timestamp; + + if (skb->len < baselen) { + tdls_dbg(sdata, "TDLS channel switch req too short: %d\n", + skb->len); + return -EINVAL; + } + + target_channel = tf->u.chan_switch_req.target_channel; + oper_class = tf->u.chan_switch_req.oper_class; + + /* + * We can't easily infer the channel band. The operating class is + * ambiguous - there are multiple tables (US/Europe/JP/Global). The + * solution here is to treat channels with number >14 as 5GHz ones, + * and specifically check for the (oper_class, channel) combinations + * where this doesn't hold. These are thankfully unique according to + * IEEE802.11-2012. + * We consider only the 2GHz and 5GHz bands and 20MHz+ channels as + * valid here. + */ + if ((oper_class == 112 || oper_class == 2 || oper_class == 3 || + oper_class == 4 || oper_class == 5 || oper_class == 6) && + target_channel < 14) + band = IEEE80211_BAND_5GHZ; + else + band = target_channel < 14 ? IEEE80211_BAND_2GHZ : + IEEE80211_BAND_5GHZ; + + freq = ieee80211_channel_to_frequency(target_channel, band); + if (freq == 0) { + tdls_dbg(sdata, "Invalid channel in TDLS chan switch: %d\n", + target_channel); + return -EINVAL; + } + + chan = ieee80211_get_channel(sdata->local->hw.wiphy, freq); + if (!chan) { + tdls_dbg(sdata, + "Unsupported channel for TDLS chan switch: %d\n", + target_channel); + return -EINVAL; + } + + ieee802_11_parse_elems(tf->u.chan_switch_req.variable, + skb->len - baselen, false, &elems); + if (elems.parse_error) { + tdls_dbg(sdata, "Invalid IEs in TDLS channel switch req\n"); + return -EINVAL; + } + + if (!elems.ch_sw_timing || !elems.lnk_id) { + tdls_dbg(sdata, "TDLS channel switch req - missing IEs\n"); + return -EINVAL; + } + + mutex_lock(&local->sta_mtx); + sta = sta_info_get(sdata, tf->sa); + if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) { + tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM\n", + tf->sa); + ret = -EINVAL; + goto out; + } + + params.sta = &sta->sta; + + /* validate the initiator is set correctly */ + local_initiator = + !memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN); + if (local_initiator == sta->sta.tdls_initiator) { + tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator\n"); + ret = -EINVAL; + goto out; + } + + if (!sta->sta.ht_cap.ht_supported) { + chan_type = NL80211_CHAN_NO_HT; + } else if (!elems.sec_chan_offs) { + chan_type = NL80211_CHAN_HT20; + } else { + switch (elems.sec_chan_offs->sec_chan_offs) { + case IEEE80211_HT_PARAM_CHA_SEC_ABOVE: + chan_type = NL80211_CHAN_HT40PLUS; + break; + case IEEE80211_HT_PARAM_CHA_SEC_BELOW: + chan_type = NL80211_CHAN_HT40MINUS; + break; + default: + chan_type = NL80211_CHAN_HT20; + break; + } + } + + cfg80211_chandef_create(&chandef, chan, chan_type); + params.chandef = &chandef; + + params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time); + params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout); + + params.tmpl_skb = + ieee80211_tdls_ch_sw_resp_tmpl_get(sta, + ¶ms.ch_sw_tm_ie); + if (!params.tmpl_skb) { + ret = -ENOENT; + goto out; + } + + drv_tdls_recv_channel_switch(sdata->local, sdata, ¶ms); + + tdls_dbg(sdata, + "TDLS ch switch request received from %pM ch %d width %d\n", + tf->sa, params.chandef->chan->center_freq, + params.chandef->width); +out: + mutex_unlock(&local->sta_mtx); + dev_kfree_skb_any(params.tmpl_skb); + return ret; +} + +void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_tdls_data *tf = (void *)skb->data; + struct wiphy *wiphy = sdata->local->hw.wiphy; + + /* make sure the driver supports it */ + if (!(wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH)) + return; + + /* we want to access the entire packet */ + if (skb_linearize(skb)) + return; + /* + * The packet/size was already validated by mac80211 Rx path, only look + * at the action type. + */ + switch (tf->action_code) { + case WLAN_TDLS_CHANNEL_SWITCH_REQUEST: + ieee80211_process_tdls_channel_switch_req(sdata, skb); + break; + case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE: + ieee80211_process_tdls_channel_switch_resp(sdata, skb); + break; + default: + WARN_ON_ONCE(1); + return; + } +} diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h index c0c0fcace9d8..7f76e2f25744 100644 --- a/net/mac80211/trace.h +++ b/net/mac80211/trace.h @@ -16,6 +16,7 @@ #define STA_ENTRY __array(char, sta_addr, ETH_ALEN) #define STA_ASSIGN (sta ? memcpy(__entry->sta_addr, sta->addr, ETH_ALEN) : memset(__entry->sta_addr, 0, ETH_ALEN)) +#define STA_NAMED_ASSIGN(s) memcpy(__entry->sta_addr, (s)->addr, ETH_ALEN) #define STA_PR_FMT " sta:%pM" #define STA_PR_ARG __entry->sta_addr @@ -2254,6 +2255,50 @@ TRACE_EVENT(drv_tdls_cancel_channel_switch, ) ); +TRACE_EVENT(drv_tdls_recv_channel_switch, + TP_PROTO(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_tdls_ch_sw_params *params), + + TP_ARGS(local, sdata, params), + + TP_STRUCT__entry( + LOCAL_ENTRY + VIF_ENTRY + __field(u8, action_code) + STA_ENTRY + CHANDEF_ENTRY + __field(u32, status) + __field(bool, peer_initiator) + __field(u32, timestamp) + __field(u16, switch_time) + __field(u16, switch_timeout) + ), + + TP_fast_assign( + LOCAL_ASSIGN; + VIF_ASSIGN; + STA_NAMED_ASSIGN(params->sta); + CHANDEF_ASSIGN(params->chandef) + __entry->peer_initiator = params->sta->tdls_initiator; + __entry->action_code = params->action_code; + __entry->status = params->status; + __entry->timestamp = params->timestamp; + __entry->switch_time = params->switch_time; + __entry->switch_timeout = params->switch_timeout; + ), + + TP_printk( + LOCAL_PR_FMT VIF_PR_FMT " received tdls channel switch packet" + " action:%d status:%d time:%d switch time:%d switch" + " timeout:%d initiator: %d chan:" CHANDEF_PR_FMT STA_PR_FMT, + LOCAL_PR_ARG, VIF_PR_ARG, __entry->action_code, __entry->status, + __entry->timestamp, __entry->switch_time, + __entry->switch_timeout, __entry->peer_initiator, + CHANDEF_PR_ARG, STA_PR_ARG + ) +); + #ifdef CONFIG_MAC80211_MESSAGE_TRACING #undef TRACE_SYSTEM #define TRACE_SYSTEM mac80211_msg -- 2.20.1