From c49e5ea322c2fb43f430abb3c4a49eae1394287e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 11 Dec 2007 21:33:42 +0100 Subject: [PATCH] mac80211: conditionally include timestamp in radiotap information This makes mac80211 include the low-level MAC timestamp in the radiotap header if the driver indicated (by a new RX flag) that the timestamp is valid. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- include/net/mac80211.h | 3 +++ net/mac80211/rx.c | 48 ++++++++++++++++++++++++++++-------------- 2 files changed, 35 insertions(+), 16 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 0d67b331ee72..3bd970f29f29 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -350,6 +350,8 @@ struct ieee80211_tx_control { * the frame. * @RX_FLAG_FAILED_PLCP_CRC: Set this flag if the PCLP check failed on * the frame. + * @RX_FLAG_TSFT: The timestamp passed in the RX status (@mactime field) + * is valid. */ enum mac80211_rx_flags { RX_FLAG_MMIC_ERROR = 1<<0, @@ -359,6 +361,7 @@ enum mac80211_rx_flags { RX_FLAG_IV_STRIPPED = 1<<4, RX_FLAG_FAILED_FCS_CRC = 1<<5, RX_FLAG_FAILED_PLCP_CRC = 1<<6, + RX_FLAG_TSFT = 1<<7, }; /** diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index c542fc1c983d..9cd59ecbcd67 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -79,8 +79,9 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, struct ieee80211_sub_if_data *sdata; struct ieee80211_rate *rate; int needed_headroom = 0; - struct ieee80211_rtap_hdr { - struct ieee80211_radiotap_header hdr; + struct ieee80211_radiotap_header *rthdr; + __le64 *rttsft = NULL; + struct ieee80211_rtap_fixed_data { u8 flags; u8 rate; __le16 chan_freq; @@ -88,7 +89,7 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, u8 antsignal; u8 padding_for_rxflags; __le16 rx_flags; - } __attribute__ ((packed)) *rthdr; + } __attribute__ ((packed)) *rtfixed; struct sk_buff *skb, *skb2; struct net_device *prev_dev = NULL; int present_fcs_len = 0; @@ -105,7 +106,8 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, if (status->flag & RX_FLAG_RADIOTAP) rtap_len = ieee80211_get_radiotap_len(origskb->data); else - needed_headroom = sizeof(*rthdr); + /* room for radiotap header, always present fields and TSFT */ + needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8; if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) present_fcs_len = FCS_LEN; @@ -133,7 +135,7 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, * them allocate enough headroom to start with. */ if (skb_headroom(skb) < needed_headroom && - pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) { + pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) { dev_kfree_skb(skb); return NULL; } @@ -152,42 +154,56 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, /* if necessary, prepend radiotap information */ if (!(status->flag & RX_FLAG_RADIOTAP)) { + rtfixed = (void *) skb_push(skb, sizeof(*rtfixed)); + rtap_len = sizeof(*rthdr) + sizeof(*rtfixed); + if (status->flag & RX_FLAG_TSFT) { + rttsft = (void *) skb_push(skb, sizeof(*rttsft)); + rtap_len += 8; + } rthdr = (void *) skb_push(skb, sizeof(*rthdr)); memset(rthdr, 0, sizeof(*rthdr)); - rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr)); - rthdr->hdr.it_present = + memset(rtfixed, 0, sizeof(*rtfixed)); + rthdr->it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) | (1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_CHANNEL) | (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) | (1 << IEEE80211_RADIOTAP_RX_FLAGS)); - rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ? - IEEE80211_RADIOTAP_F_FCS : 0; + rtfixed->flags = 0; + if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) + rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS; + + if (rttsft) { + *rttsft = cpu_to_le64(status->mactime); + rthdr->it_present |= + cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT); + } /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */ - rthdr->rx_flags = 0; + rtfixed->rx_flags = 0; if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC)) - rthdr->rx_flags |= + rtfixed->rx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS); rate = ieee80211_get_rate(local, status->phymode, status->rate); if (rate) - rthdr->rate = rate->rate / 5; + rtfixed->rate = rate->rate / 5; - rthdr->chan_freq = cpu_to_le16(status->freq); + rtfixed->chan_freq = cpu_to_le16(status->freq); if (status->phymode == MODE_IEEE80211A) - rthdr->chan_flags = + rtfixed->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ); else - rthdr->chan_flags = + rtfixed->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ); - rthdr->antsignal = status->ssi; + rtfixed->antsignal = status->ssi; + rthdr->it_len = cpu_to_le16(rtap_len); } skb_set_mac_header(skb, 0); -- 2.20.1