From: Benjamin Berg mac80211 already reports some basic information in the radiotap header with the known fields declared by the driver. However, drivers may want to report more accurate information and in that case the full VHT radiotap structure needs to be provided. Add a new RX_FLAG_RADIOTAP_VHT which is set when the VHT information should be pulled from the skb. Update the code to fill in the VHT fields to only do so when requested by the driver or if the information has not yet been set. This way the driver can fully control the information if it chooses so. Signed-off-by: Benjamin Berg Reviewed-by: Johannes Berg Signed-off-by: Miri Korenblit --- v2: add the destination tree to the subject v3: fix kernel documentation include/net/ieee80211_radiotap.h | 20 +++++- include/net/mac80211.h | 2 + net/mac80211/rx.c | 104 ++++++++++++++++++++----------- 3 files changed, 89 insertions(+), 37 deletions(-) diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h index 813e163ce27c..c60867e7e43c 100644 --- a/include/net/ieee80211_radiotap.h +++ b/include/net/ieee80211_radiotap.h @@ -1,6 +1,6 @@ /* * Copyright (c) 2017 Intel Deutschland GmbH - * Copyright (c) 2018-2019, 2021-2022 Intel Corporation + * Copyright (c) 2018-2019, 2021-2022, 2025 Intel Corporation * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -202,6 +202,24 @@ enum ieee80211_radiotap_vht_coding { IEEE80211_RADIOTAP_CODING_LDPC_USER3 = 0x08, }; +enum ieee80211_radiotap_vht_bandwidth { + /* Note: more values are defined but can't really be used */ + IEEE80211_RADIOTAP_VHT_BW_20 = 0, + IEEE80211_RADIOTAP_VHT_BW_40 = 1, + IEEE80211_RADIOTAP_VHT_BW_80 = 4, + IEEE80211_RADIOTAP_VHT_BW_160 = 11, +}; + +struct ieee80211_radiotap_vht { + __le16 known; + u8 flags; + u8 bandwidth; + u8 mcs_nss[4]; + u8 coding; + u8 group_id; + __le16 partial_aid; +} __packed; + /* for IEEE80211_RADIOTAP_TIMESTAMP */ enum ieee80211_radiotap_timestamp_unit_spos { IEEE80211_RADIOTAP_TIMESTAMP_UNIT_MASK = 0x000F, diff --git a/include/net/mac80211.h b/include/net/mac80211.h index a55085cf4ec4..c326243e1f01 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1529,6 +1529,7 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info) * known the frame shouldn't be reported. * @RX_FLAG_8023: the frame has an 802.3 header (decap offload performed by * hardware or driver) + * @RX_FLAG_RADIOTAP_VHT: VHT radiotap data is present */ enum mac80211_rx_flags { RX_FLAG_MMIC_ERROR = BIT(0), @@ -1564,6 +1565,7 @@ enum mac80211_rx_flags { RX_FLAG_RADIOTAP_LSIG = BIT(28), RX_FLAG_NO_PSDU = BIT(29), RX_FLAG_8023 = BIT(30), + RX_FLAG_RADIOTAP_VHT = BIT(31), }; /** diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 4641a2a80856..b59aeed340b3 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -59,7 +59,8 @@ static struct sk_buff *ieee80211_clean_skb(struct sk_buff *skb, status->flag &= ~(RX_FLAG_RADIOTAP_TLV_AT_END | RX_FLAG_RADIOTAP_LSIG | RX_FLAG_RADIOTAP_HE_MU | - RX_FLAG_RADIOTAP_HE); + RX_FLAG_RADIOTAP_HE | + RX_FLAG_RADIOTAP_VHT); hdr = (void *)skb->data; fc = hdr->frame_control; @@ -151,8 +152,10 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local, } if (status->encoding == RX_ENC_VHT) { + /* Included even if RX_FLAG_RADIOTAP_VHT is not set */ len = ALIGN(len, 2); len += 12; + BUILD_BUG_ON(sizeof(struct ieee80211_radiotap_vht) != 12); } if (local->hw.radiotap_timestamp.units_pos >= 0) { @@ -195,6 +198,9 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local, * The position to look at depends on the existence (or non- * existence) of other elements, so take that into account... */ + if (status->flag & RX_FLAG_RADIOTAP_VHT) + tlv_offset += + sizeof(struct ieee80211_radiotap_vht); if (status->flag & RX_FLAG_RADIOTAP_HE) tlv_offset += sizeof(struct ieee80211_radiotap_he); @@ -319,10 +325,17 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, u32 tlvs_len = 0; int mpdulen, chain; unsigned long chains = status->chains; + struct ieee80211_radiotap_vht vht = {}; struct ieee80211_radiotap_he he = {}; struct ieee80211_radiotap_he_mu he_mu = {}; struct ieee80211_radiotap_lsig lsig = {}; + if (status->flag & RX_FLAG_RADIOTAP_VHT) { + vht = *(struct ieee80211_radiotap_vht *)skb->data; + skb_pull(skb, sizeof(vht)); + WARN_ON_ONCE(status->encoding != RX_ENC_VHT); + } + if (status->flag & RX_FLAG_RADIOTAP_HE) { he = *(struct ieee80211_radiotap_he *)skb->data; skb_pull(skb, sizeof(he)); @@ -530,45 +543,61 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, } if (status->encoding == RX_ENC_VHT) { - u16 known = local->hw.radiotap_vht_details; + u16 fill = local->hw.radiotap_vht_details; - rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_VHT)); - put_unaligned_le16(known, pos); - pos += 2; - /* flags */ - if (status->enc_flags & RX_ENC_FLAG_SHORT_GI) - *pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI; + /* Leave driver filled fields alone */ + fill &= ~le16_to_cpu(vht.known); + vht.known |= cpu_to_le16(fill); + + if (fill & IEEE80211_RADIOTAP_VHT_KNOWN_GI && + status->enc_flags & RX_ENC_FLAG_SHORT_GI) + vht.flags |= IEEE80211_RADIOTAP_VHT_FLAG_SGI; /* in VHT, STBC is binary */ - if (status->enc_flags & RX_ENC_FLAG_STBC_MASK) - *pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC; - if (status->enc_flags & RX_ENC_FLAG_BF) + if (fill & IEEE80211_RADIOTAP_VHT_KNOWN_STBC && + status->enc_flags & RX_ENC_FLAG_STBC_MASK) + vht.flags |= IEEE80211_RADIOTAP_VHT_FLAG_STBC; + if (fill & IEEE80211_RADIOTAP_VHT_KNOWN_BEAMFORMED && + status->enc_flags & RX_ENC_FLAG_BF) *pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED; - pos++; - /* bandwidth */ - switch (status->bw) { - case RATE_INFO_BW_80: - *pos++ = 4; - break; - case RATE_INFO_BW_160: - *pos++ = 11; - break; - case RATE_INFO_BW_40: - *pos++ = 1; - break; - default: - *pos++ = 0; + + if (fill & IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH) { + switch (status->bw) { + case RATE_INFO_BW_40: + vht.bandwidth = IEEE80211_RADIOTAP_VHT_BW_40; + break; + case RATE_INFO_BW_80: + vht.bandwidth = IEEE80211_RADIOTAP_VHT_BW_80; + break; + case RATE_INFO_BW_160: + vht.bandwidth = IEEE80211_RADIOTAP_VHT_BW_160; + break; + default: + vht.bandwidth = IEEE80211_RADIOTAP_VHT_BW_20; + break; + } } - /* MCS/NSS */ - *pos = (status->rate_idx << 4) | status->nss; - pos += 4; - /* coding field */ - if (status->enc_flags & RX_ENC_FLAG_LDPC) - *pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0; - pos++; - /* group ID */ - pos++; - /* partial_aid */ - pos += 2; + + /* + * If the driver filled in mcs_nss[0], then do not touch it. + * + * Otherwise, put some information about MCS/NSS into the + * user 0 field. Note that this is not technically correct for + * an MU frame as we might have decoded a different user. + */ + if (!vht.mcs_nss[0]) { + vht.mcs_nss[0] = (status->rate_idx << 4) | status->nss; + + /* coding field */ + if (status->enc_flags & RX_ENC_FLAG_LDPC) + vht.coding |= IEEE80211_RADIOTAP_CODING_LDPC_USER0; + } + + /* ensure 2 byte alignment */ + while ((pos - (u8 *)rthdr) & 1) + pos++; + rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_VHT)); + memcpy(pos, &vht, sizeof(vht)); + pos += sizeof(vht); } if (local->hw.radiotap_timestamp.units_pos >= 0) { @@ -834,6 +863,9 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, return NULL; } + if (status->flag & RX_FLAG_RADIOTAP_VHT) + rtap_space += sizeof(struct ieee80211_radiotap_vht); + if (status->flag & RX_FLAG_RADIOTAP_HE) rtap_space += sizeof(struct ieee80211_radiotap_he); -- 2.34.1