use hw flags and rx flags to determine which fields are present in the header
and use all available information from the driver.
make sure radiotap header starts at a naturally aligned address (mod 8) for
all radiotap fields.
Signed-off-by: Bruno Randolf <br1@xxxxxxxxxxx>
---
net/mac80211/rx.c | 195 ++++++++++++++++++++++++++++++++++++-----------------
1 files changed, 133 insertions(+), 62 deletions(-)
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3ea856f..69e2677 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -77,6 +77,134 @@ static inline int should_drop_frame(struct ieee80211_rx_status *status,
return 0;
}
+static int
+ieee80211_rx_radiotap_len(struct ieee80211_local *local,
+ struct ieee80211_rx_status *status)
+{
+ int len;
+
+ /* always present fields */
+ len = sizeof(struct ieee80211_radiotap_header) + 9;
+
+ if (status->flag & RX_FLAG_TSFT)
+ len += 8;
+ if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
+ local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
+ len += 1;
+ if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
+ len += 1;
+
+ if (len & 1) /* padding for RX_FLAGS if necessary */
+ len++;
+
+ /* make sure radiotap starts at a naturally aligned address */
+ if (len % 8)
+ len = roundup(len, 8);
+
+ return len;
+}
+
+/**
+ * ieee80211_add_rx_radiotap_header - add radiotap header
+ *
+ * add a radiotap header containing all the fields which the hardware provided.
+ */
+static void
+ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
+ struct sk_buff *skb,
+ struct ieee80211_rx_status *status,
+ struct ieee80211_rate *rate,
+ int rtap_len)
+{
+ struct ieee80211_radiotap_header *rthdr;
+ unsigned char *pos;
+
+ rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
+ memset(rthdr, 0, rtap_len);
+
+ /* radiotap header, set always present flags */
+ rthdr->it_present =
+ cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
+ (1 << IEEE80211_RADIOTAP_RATE) |
+ (1 << IEEE80211_RADIOTAP_CHANNEL) |
+ (1 << IEEE80211_RADIOTAP_ANTENNA) |
+ (1 << IEEE80211_RADIOTAP_RX_FLAGS));
+ rthdr->it_len = cpu_to_le16(rtap_len);
+
+ pos = (unsigned char *)(rthdr+1);
+
+ /* the order of the following fields is important */
+
+ /* IEEE80211_RADIOTAP_TSFT */
+ if (status->flag & RX_FLAG_TSFT) {
+ *(__le64 *)pos = cpu_to_le64(status->mactime);
+ rthdr->it_present |=
+ cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
+ pos += 8;
+ }
+
+ /* IEEE80211_RADIOTAP_FLAGS */
+ if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
+ *pos |= IEEE80211_RADIOTAP_F_FCS;
+ pos++;
+
+ /* IEEE80211_RADIOTAP_RATE */
+ *pos = rate->bitrate / 5;
+ pos++;
+
+ /* IEEE80211_RADIOTAP_CHANNEL */
+ *(__le16 *)pos = cpu_to_le16(status->freq);
+ pos += 2;
+ if (status->band == IEEE80211_BAND_5GHZ)
+ *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
+ IEEE80211_CHAN_5GHZ);
+ else
+ *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_DYN |
+ IEEE80211_CHAN_2GHZ);
+ pos += 2;
+
+ /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
+ if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
+ *pos = status->signal;
+ rthdr->it_present |=
+ cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
+ pos++;
+ }
+
+ /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
+ if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
+ *pos = status->noise;
+ rthdr->it_present |=
+ cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
+ pos++;
+ }
+
+ /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
+
+ /* IEEE80211_RADIOTAP_ANTENNA */
+ *pos = status->antenna;
+ pos++;
+
+ /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
+ if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
+ *pos = status->signal;
+ rthdr->it_present |=
+ cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
+ pos++;
+ }
+
+ /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
+
+ /* IEEE80211_RADIOTAP_RX_FLAGS */
+ /* ensure 2 byte alignment for the 2 byte field as required */
+ if ((pos - (unsigned char *)rthdr) & 1)
+ pos++;
+ /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
+ if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
+ *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
+ pos += 2;
+}
+
/*
* This function copies a received frame to all monitor interfaces and
* returns a cleaned-up SKB that no longer includes the FCS nor the
@@ -89,17 +217,6 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
{
struct ieee80211_sub_if_data *sdata;
int needed_headroom = 0;
- struct ieee80211_radiotap_header *rthdr;
- __le64 *rttsft = NULL;
- struct ieee80211_rtap_fixed_data {
- u8 flags;
- u8 rate;
- __le16 chan_freq;
- __le16 chan_flags;
- u8 antsignal;
- u8 padding_for_rxflags;
- __le16 rx_flags;
- } __attribute__ ((packed)) *rtfixed;
struct sk_buff *skb, *skb2;
struct net_device *prev_dev = NULL;
int present_fcs_len = 0;
@@ -116,8 +233,8 @@ 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
- /* room for radiotap header, always present fields and TSFT */
- needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
+ /* room for the radiotap header based on driver features */
+ needed_headroom = ieee80211_rx_radiotap_len(local, status);
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
present_fcs_len = FCS_LEN;
@@ -163,55 +280,9 @@ 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));
- 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));
- 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 */
- rtfixed->rx_flags = 0;
- if (status->flag &
- (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
- rtfixed->rx_flags |=
- cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
-
- rtfixed->rate = rate->bitrate / 5;
-
- rtfixed->chan_freq = cpu_to_le16(status->freq);
-
- if (status->band == IEEE80211_BAND_5GHZ)
- rtfixed->chan_flags =
- cpu_to_le16(IEEE80211_CHAN_OFDM |
- IEEE80211_CHAN_5GHZ);
- else
- rtfixed->chan_flags =
- cpu_to_le16(IEEE80211_CHAN_DYN |
- IEEE80211_CHAN_2GHZ);
-
- rtfixed->antsignal = status->signal;
- rthdr->it_len = cpu_to_le16(rtap_len);
- }
+ if (!(status->flag & RX_FLAG_RADIOTAP))
+ ieee80211_add_rx_radiotap_header(local, skb, status, rate,
+ needed_headroom);
skb_reset_mac_header(skb);
skb->ip_summed = CHECKSUM_UNNECESSARY;
--
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