From c3d1f8752802b2e1fb12c73bee50035bc125bc54 Mon Sep 17 00:00:00 2001 From: Shaul Triebitz Date: Wed, 5 Sep 2018 08:06:06 +0300 Subject: [PATCH] mac80211: support reporting 0-length PSDU in radiotap For certain sounding frames, it may be useful to report them to userspace even though they don't have a PSDU in order to determine the PHY parameters (e.g. VHT rate/stream config.) Add support for this to mac80211. Signed-off-by: Johannes Berg Signed-off-by: Shaul Triebitz Signed-off-by: Luca Coelho Signed-off-by: Johannes Berg --- include/net/ieee80211_radiotap.h | 6 ++++++ include/net/mac80211.h | 7 +++++++ net/mac80211/rx.c | 12 +++++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h index 80d543902b8b..8014153bdd49 100644 --- a/include/net/ieee80211_radiotap.h +++ b/include/net/ieee80211_radiotap.h @@ -75,6 +75,7 @@ enum ieee80211_radiotap_presence { IEEE80211_RADIOTAP_TIMESTAMP = 22, IEEE80211_RADIOTAP_HE = 23, IEEE80211_RADIOTAP_HE_MU = 24, + IEEE80211_RADIOTAP_ZERO_LEN_PSDU = 26, IEEE80211_RADIOTAP_LSIG = 27, /* valid in every it_present bitmap, even vendor namespaces */ @@ -340,6 +341,11 @@ struct ieee80211_radiotap_lsig { __le16 data1, data2; }; +enum ieee80211_radiotap_zero_len_psdu_type { + IEEE80211_RADIOTAP_ZERO_LEN_PSDU_SOUNDING = 0, + IEEE80211_RADIOTAP_ZERO_LEN_PSDU_VENDOR = 0xff, +}; + /** * ieee80211_get_radiotap_len - get radiotap header length */ diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 8c26d2d36cbe..50bf598abdfd 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1142,6 +1142,10 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info) * @RX_FLAG_RADIOTAP_HE_MU: HE MU radiotap data is present * (&struct ieee80211_radiotap_he_mu) * @RX_FLAG_RADIOTAP_LSIG: L-SIG radiotap data is present + * @RX_FLAG_NO_PSDU: use the frame only for radiotap reporting, with + * the "0-length PSDU" field included there. The value for it is + * in &struct ieee80211_rx_status. Note that if this value isn't + * known the frame shouldn't be reported. */ enum mac80211_rx_flags { RX_FLAG_MMIC_ERROR = BIT(0), @@ -1173,6 +1177,7 @@ enum mac80211_rx_flags { RX_FLAG_RADIOTAP_HE = BIT(26), RX_FLAG_RADIOTAP_HE_MU = BIT(27), RX_FLAG_RADIOTAP_LSIG = BIT(28), + RX_FLAG_NO_PSDU = BIT(29), }; /** @@ -1245,6 +1250,7 @@ enum mac80211_rx_encoding { * @ampdu_reference: A-MPDU reference number, must be a different value for * each A-MPDU but the same for each subframe within one A-MPDU * @ampdu_delimiter_crc: A-MPDU delimiter CRC + * @zero_length_psdu_type: radiotap type of the 0-length PSDU */ struct ieee80211_rx_status { u64 mactime; @@ -1265,6 +1271,7 @@ struct ieee80211_rx_status { u8 chains; s8 chain_signal[IEEE80211_MAX_CHAINS]; u8 ampdu_delimiter_crc; + u8 zero_length_psdu_type; }; /** diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 4376a4ce8c25..c6bfd4019d44 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -115,7 +115,8 @@ static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len, if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC | - RX_FLAG_ONLY_MONITOR)) + RX_FLAG_ONLY_MONITOR | + RX_FLAG_NO_PSDU)) return true; if (unlikely(skb->len < 16 + present_fcs_len + rtap_space)) @@ -189,6 +190,9 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local, BUILD_BUG_ON(sizeof(struct ieee80211_radiotap_he_mu) != 12); } + if (status->flag & RX_FLAG_NO_PSDU) + len += 1; + if (status->flag & RX_FLAG_RADIOTAP_LSIG) { len = ALIGN(len, 2); len += 4; @@ -642,6 +646,12 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, pos += sizeof(he_mu); } + if (status->flag & RX_FLAG_NO_PSDU) { + rthdr->it_present |= + cpu_to_le32(1 << IEEE80211_RADIOTAP_ZERO_LEN_PSDU); + *pos++ = status->zero_length_psdu_type; + } + if (status->flag & RX_FLAG_RADIOTAP_LSIG) { /* ensure 2 byte alignment */ while ((pos - (u8 *)rthdr) & 1) -- 2.30.2