From a7a6bdd0670feb8bfc26d41cda32b6064dbca50e Mon Sep 17 00:00:00 2001 From: Arik Nemtsov Date: Sun, 9 Nov 2014 18:50:19 +0200 Subject: [PATCH] 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 Signed-off-by: Arik Nemtsov Signed-off-by: Johannes Berg --- include/net/mac80211.h | 19 +++ net/mac80211/cfg.c | 2 + net/mac80211/debugfs_sta.c | 10 +- net/mac80211/driver-ops.h | 41 +++++++ net/mac80211/ieee80211_i.h | 6 + net/mac80211/main.c | 5 + net/mac80211/sta_info.c | 9 ++ net/mac80211/sta_info.h | 3 + net/mac80211/tdls.c | 234 +++++++++++++++++++++++++++++++++++++ net/mac80211/trace.h | 57 +++++++++ 10 files changed, 381 insertions(+), 5 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 83232aa2f077..fdedceb7adcb 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -2915,6 +2915,16 @@ enum ieee80211_reconfig_type { * * @get_txpower: get current maximum tx power (in dBm) based on configuration * and hardware limits. + * + * @tdls_channel_switch: Start channel-switching with a TDLS peer. The driver + * is responsible for continually initiating channel-switching operations + * and returning to the base channel for communication with the AP. The + * driver receives a channel-switch request template and the location of + * the switch-timing IE within the template as part of the invocation. + * The template is valid only within the call, and the driver can + * 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. */ struct ieee80211_ops { void (*tx)(struct ieee80211_hw *hw, @@ -3126,6 +3136,15 @@ struct ieee80211_ops { u32 (*get_expected_throughput)(struct ieee80211_sta *sta); int (*get_txpower)(struct ieee80211_hw *hw, struct ieee80211_vif *vif, int *dbm); + + int (*tdls_channel_switch)(struct ieee80211_hw *hw, + 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); + void (*tdls_cancel_channel_switch)(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_sta *sta); }; /** diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 8195e65d8a91..e75d5c53e97b 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -3752,6 +3752,8 @@ const struct cfg80211_ops mac80211_config_ops = { .set_rekey_data = ieee80211_set_rekey_data, .tdls_oper = ieee80211_tdls_oper, .tdls_mgmt = ieee80211_tdls_mgmt, + .tdls_channel_switch = ieee80211_tdls_channel_switch, + .tdls_cancel_channel_switch = ieee80211_tdls_cancel_channel_switch, .probe_client = ieee80211_probe_client, .set_noack_map = ieee80211_set_noack_map, #ifdef CONFIG_PM diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c index 2ba7f53746da..94c70091bbd7 100644 --- a/net/mac80211/debugfs_sta.c +++ b/net/mac80211/debugfs_sta.c @@ -74,7 +74,7 @@ static ssize_t sta_flags_read(struct file *file, char __user *userbuf, test_sta_flag(sta, WLAN_STA_##flg) ? #flg "\n" : "" int res = scnprintf(buf, sizeof(buf), - "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s", + "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s", TEST(AUTH), TEST(ASSOC), TEST(PS_STA), TEST(PS_DRIVER), TEST(AUTHORIZED), TEST(SHORT_PREAMBLE), @@ -83,10 +83,10 @@ static ssize_t sta_flags_read(struct file *file, char __user *userbuf, TEST(MFP), TEST(BLOCK_BA), TEST(PSPOLL), TEST(UAPSD), TEST(SP), TEST(TDLS_PEER), TEST(TDLS_PEER_AUTH), TEST(TDLS_INITIATOR), - TEST(TDLS_CHAN_SWITCH), TEST(4ADDR_EVENT), - TEST(INSERTED), TEST(RATE_CONTROL), - TEST(TOFFSET_KNOWN), TEST(MPSP_OWNER), - TEST(MPSP_RECIPIENT)); + TEST(TDLS_CHAN_SWITCH), TEST(TDLS_OFF_CHANNEL), + TEST(4ADDR_EVENT), TEST(INSERTED), + TEST(RATE_CONTROL), TEST(TOFFSET_KNOWN), + TEST(MPSP_OWNER), TEST(MPSP_RECIPIENT)); #undef TEST return simple_read_from_buffer(userbuf, count, ppos, buf, res); } diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index 9759dd1f0734..ec4ae42ac15f 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -1296,4 +1296,45 @@ static inline int drv_get_txpower(struct ieee80211_local *local, return ret; } +static inline int +drv_tdls_channel_switch(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_sta *sta, u8 oper_class, + struct cfg80211_chan_def *chandef, + struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie) +{ + int ret; + + might_sleep(); + if (!check_sdata_in_driver(sdata)) + return -EIO; + + if (!local->ops->tdls_channel_switch) + return -EOPNOTSUPP; + + trace_drv_tdls_channel_switch(local, sdata, sta, oper_class, chandef); + ret = local->ops->tdls_channel_switch(&local->hw, &sdata->vif, sta, + oper_class, chandef, tmpl_skb, + ch_sw_tm_ie); + trace_drv_return_int(local, ret); + return ret; +} + +static inline void +drv_tdls_cancel_channel_switch(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_sta *sta) +{ + might_sleep(); + if (!check_sdata_in_driver(sdata)) + return; + + if (!local->ops->tdls_cancel_channel_switch) + return; + + trace_drv_tdls_cancel_channel_switch(local, sdata, sta); + local->ops->tdls_cancel_channel_switch(&local->hw, &sdata->vif, sta); + trace_drv_return_void(local); +} + #endif /* __MAC80211_DRIVER_OPS */ diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index e786ab6bc72c..2c7abc077b6b 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -2007,6 +2007,12 @@ int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev, int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, const u8 *peer, enum nl80211_tdls_operation oper); void ieee80211_tdls_peer_del_work(struct work_struct *wk); +int ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev, + const u8 *addr, u8 oper_class, + struct cfg80211_chan_def *chandef); +void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, + struct net_device *dev, + const u8 *addr); extern const struct ethtool_ops ieee80211_ethtool_ops; diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 282a4f36eb92..774ccb2d9a76 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -764,6 +764,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) local->hw.offchannel_tx_hw_queue >= local->hw.queues)) return -EINVAL; + if ((hw->wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) && + (!local->ops->tdls_channel_switch || + !local->ops->tdls_cancel_channel_switch)) + return -EOPNOTSUPP; + #ifdef CONFIG_PM if (hw->wiphy->wowlan && (!local->ops->suspend || !local->ops->resume)) return -EINVAL; diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 97372514f287..86ca62765699 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -847,6 +847,15 @@ static int __must_check __sta_info_destroy_part1(struct sta_info *sta) if (WARN_ON(ret)) return ret; + /* + * for TDLS peers, make sure to return to the base channel before + * removal. + */ + if (test_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL)) { + drv_tdls_cancel_channel_switch(local, sdata, &sta->sta); + clear_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL); + } + list_del_rcu(&sta->list); drv_sta_pre_rcu_remove(local, sta->sdata, sta); diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index b6702c810ad3..00f56eb72c60 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -50,6 +50,8 @@ * @WLAN_STA_TDLS_INITIATOR: We are the initiator of the TDLS link with this * station. * @WLAN_STA_TDLS_CHAN_SWITCH: This TDLS peer supports TDLS channel-switching + * @WLAN_STA_TDLS_OFF_CHANNEL: The local STA is currently off-channel with this + * TDLS peer * @WLAN_STA_UAPSD: Station requested unscheduled SP while driver was * keeping station in power-save mode, reply when the driver * unblocks the station. @@ -80,6 +82,7 @@ enum ieee80211_sta_info_flags { WLAN_STA_TDLS_PEER_AUTH, WLAN_STA_TDLS_INITIATOR, WLAN_STA_TDLS_CHAN_SWITCH, + WLAN_STA_TDLS_OFF_CHANNEL, WLAN_STA_UAPSD, WLAN_STA_SP, WLAN_STA_4ADDR_EVENT, diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c index fa141aecd986..358f9a4512ad 100644 --- a/net/mac80211/tdls.c +++ b/net/mac80211/tdls.c @@ -449,6 +449,48 @@ ieee80211_tdls_add_setup_cfm_ies(struct ieee80211_sub_if_data *sdata, 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 @@ static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata, 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 @@ ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev, 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 @@ ieee80211_tdls_build_mgmt_packet_data(struct ieee80211_sub_if_data *sdata, 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 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev, initiator = false; break; case WLAN_TDLS_TEARDOWN: + case WLAN_TDLS_CHANNEL_SWITCH_REQUEST: /* any value is ok */ break; default: @@ -1046,3 +1102,181 @@ void ieee80211_tdls_oper_request(struct ieee80211_vif *vif, const u8 *peer, 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); +} diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h index 96847e788488..c0c0fcace9d8 100644 --- a/net/mac80211/trace.h +++ b/net/mac80211/trace.h @@ -2196,6 +2196,63 @@ TRACE_EVENT(drv_get_txpower, ) ); +TRACE_EVENT(drv_tdls_channel_switch, + TP_PROTO(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_sta *sta, u8 oper_class, + struct cfg80211_chan_def *chandef), + + TP_ARGS(local, sdata, sta, oper_class, chandef), + + TP_STRUCT__entry( + LOCAL_ENTRY + VIF_ENTRY + STA_ENTRY + __field(u8, oper_class) + CHANDEF_ENTRY + ), + + TP_fast_assign( + LOCAL_ASSIGN; + VIF_ASSIGN; + STA_ASSIGN; + __entry->oper_class = oper_class; + CHANDEF_ASSIGN(chandef) + ), + + TP_printk( + LOCAL_PR_FMT VIF_PR_FMT " tdls channel switch to" + CHANDEF_PR_FMT " oper_class:%d " STA_PR_FMT, + LOCAL_PR_ARG, VIF_PR_ARG, CHANDEF_PR_ARG, __entry->oper_class, + STA_PR_ARG + ) +); + +TRACE_EVENT(drv_tdls_cancel_channel_switch, + TP_PROTO(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_sta *sta), + + TP_ARGS(local, sdata, sta), + + TP_STRUCT__entry( + LOCAL_ENTRY + VIF_ENTRY + STA_ENTRY + ), + + TP_fast_assign( + LOCAL_ASSIGN; + VIF_ASSIGN; + STA_ASSIGN; + ), + + TP_printk( + LOCAL_PR_FMT VIF_PR_FMT + " tdls cancel channel switch with " STA_PR_FMT, + LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG + ) +); #ifdef CONFIG_MAC80211_MESSAGE_TRACING #undef TRACE_SYSTEM -- 2.20.1