From 170fd0b1f6108b48df4369afa0ee29a83e922748 Mon Sep 17 00:00:00 2001 From: Andrei Otcheretianski Date: Wed, 30 Jul 2014 14:36:18 +0300 Subject: [PATCH] ieee80211: Support parsing TPC report element in action frames TPC report element is contained in spectrum management's tpc report action frames and in radio measurement's link measurement report action frames. Add a function which checks whether an action frame contains this element. This may be needed by the drivers in order to set the correct tx power value in these frames. Signed-off-by: Andrei Otcheretianski Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- include/linux/ieee80211.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 63ab3873..8018c91 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -838,6 +838,16 @@ enum ieee80211_vht_opmode_bits { #define WLAN_SA_QUERY_TR_ID_LEN 2 +/** + * struct ieee80211_tpc_report_ie + * + * This structure refers to "TPC Report element" + */ +struct ieee80211_tpc_report_ie { + u8 tx_power; + u8 link_margin; +} __packed; + struct ieee80211_mgmt { __le16 frame_control; __le16 duration; @@ -973,6 +983,13 @@ struct ieee80211_mgmt { u8 action_code; u8 operating_mode; } __packed vht_opmode_notif; + struct { + u8 action_code; + u8 dialog_token; + u8 tpc_elem_id; + u8 tpc_elem_length; + struct ieee80211_tpc_report_ie tpc; + } __packed tpc_report; } u; } __packed action; } u; @@ -1865,6 +1882,7 @@ enum ieee80211_category { WLAN_CATEGORY_DLS = 2, WLAN_CATEGORY_BACK = 3, WLAN_CATEGORY_PUBLIC = 4, + WLAN_CATEGORY_RADIO_MEASUREMENT = 5, WLAN_CATEGORY_HT = 7, WLAN_CATEGORY_SA_QUERY = 8, WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION = 9, @@ -2378,4 +2396,51 @@ static inline bool ieee80211_check_tim(const struct ieee80211_tim_ie *tim, #define TU_TO_JIFFIES(x) (usecs_to_jiffies((x) * 1024)) #define TU_TO_EXP_TIME(x) (jiffies + TU_TO_JIFFIES(x)) +/** + * ieee80211_action_contains_tpc - checks if the frame contains TPC element + * @skb: the skb containing the frame, length will be checked + * + * This function checks if it's either TPC report action frame or Link + * Measurement report action frame as defined in IEEE Std. 802.11-2012 8.5.2.5 + * and 8.5.7.5 accordingly. + */ +static inline bool ieee80211_action_contains_tpc(struct sk_buff *skb) +{ + struct ieee80211_mgmt *mgmt = (void *)skb->data; + + if (!ieee80211_is_action(mgmt->frame_control)) + return false; + + if (skb->len < IEEE80211_MIN_ACTION_SIZE + + sizeof(mgmt->u.action.u.tpc_report)) + return false; + + /* + * TPC report - check that: + * category = 0 (Spectrum Management) or 5 (Radio Measurement) + * spectrum management action = 3 (TPC/Link Measurement report) + * TPC report EID = 35 + * TPC report element length = 2 + * + * The spectrum management's tpc_report struct is used here both for + * parsing tpc_report and radio measurement's link measurement report + * frame, since the relevant part is identical in both frames. + */ + if (mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT && + mgmt->u.action.category != WLAN_CATEGORY_RADIO_MEASUREMENT) + return false; + + /* both spectrum mgmt and link measurement have same action code */ + if (mgmt->u.action.u.tpc_report.action_code != + WLAN_ACTION_SPCT_TPC_RPRT) + return false; + + if (mgmt->u.action.u.tpc_report.tpc_elem_id != WLAN_EID_TPC_REPORT || + mgmt->u.action.u.tpc_report.tpc_elem_length != + sizeof(struct ieee80211_tpc_report_ie)) + return false; + + return true; +} + #endif /* LINUX_IEEE80211_H */ -- 2.7.4