mac80211: add per-chain signal information to radiotap

When per-chain signal information is available, don't add
the antenna field once but instead add a radiotap namespace
for each chain containing the chain/antenna number and the
signal strength on that chain.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 23dbcfc..c9f2ca4 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -87,11 +87,13 @@ ieee80211_rx_radiotap_space(struct ieee80211_local *local,
        int len;
 
        /* always present fields */
-       len = sizeof(struct ieee80211_radiotap_header) + 9;
+       len = sizeof(struct ieee80211_radiotap_header) + 8;
 
-       /* allocate extra bitmap */
+       /* allocate extra bitmaps */
        if (status->vendor_radiotap_len)
                len += 4;
+       if (status->chains)
+               len += 4 * hweight8(status->chains);
 
        if (ieee80211_have_rx_timestamp(status)) {
                len = ALIGN(len, 8);
@@ -100,6 +102,10 @@ ieee80211_rx_radiotap_space(struct ieee80211_local *local,
        if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
                len += 1;
 
+       /* antenna field, if we don't have per-chain info */
+       if (!status->chains)
+               len += 1;
+
        /* padding for RX_FLAGS if necessary */
        len = ALIGN(len, 2);
 
@@ -116,6 +122,11 @@ ieee80211_rx_radiotap_space(struct ieee80211_local *local,
                len += 12;
        }
 
+       if (status->chains) {
+               /* antenna and antenna signal fields */
+               len += 2 * hweight8(status->chains);
+       }
+
        if (status->vendor_radiotap_len) {
                if (WARN_ON_ONCE(status->vendor_radiotap_align == 0))
                        status->vendor_radiotap_align = 1;
@@ -145,8 +156,11 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
        struct ieee80211_radiotap_header *rthdr;
        unsigned char *pos;
+       __le32 *it_present;
+       u32 it_present_val;
        u16 rx_flags = 0;
-       int mpdulen;
+       int mpdulen, chain;
+       unsigned long chains = status->chains;
 
        mpdulen = skb->len;
        if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
@@ -154,25 +168,39 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 
        rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
        memset(rthdr, 0, rtap_len);
+       it_present = &rthdr->it_present;
 
        /* radiotap header, set always present flags */
-       rthdr->it_present =
-               cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
-                           (1 << IEEE80211_RADIOTAP_CHANNEL) |
-                           (1 << IEEE80211_RADIOTAP_ANTENNA) |
-                           (1 << IEEE80211_RADIOTAP_RX_FLAGS));
        rthdr->it_len = cpu_to_le16(rtap_len + status->vendor_radiotap_len);
+       it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
+                        BIT(IEEE80211_RADIOTAP_CHANNEL) |
+                        BIT(IEEE80211_RADIOTAP_RX_FLAGS);
+
+       if (!status->chains)
+               it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
 
-       pos = (unsigned char *)(rthdr + 1);
+       for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
+               it_present_val |=
+                       BIT(IEEE80211_RADIOTAP_EXT) |
+                       BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
+               put_unaligned_le32(it_present_val, it_present);
+               it_present++;
+               it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
+                                BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
+       }
 
        if (status->vendor_radiotap_len) {
-               rthdr->it_present |=
-                       cpu_to_le32(BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE)) |
-                       cpu_to_le32(BIT(IEEE80211_RADIOTAP_EXT));
-               put_unaligned_le32(status->vendor_radiotap_bitmap, pos);
-               pos += 4;
+               it_present_val |= BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE) |
+                                 BIT(IEEE80211_RADIOTAP_EXT);
+               put_unaligned_le32(it_present_val, it_present);
+               it_present++;
+               it_present_val = status->vendor_radiotap_bitmap;
        }
 
+       put_unaligned_le32(it_present_val, it_present);
+
+       pos = (void *)(it_present + 1);
+
        /* the order of the following fields is important */
 
        /* IEEE80211_RADIOTAP_TSFT */
@@ -242,9 +270,11 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 
        /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 
-       /* IEEE80211_RADIOTAP_ANTENNA */
-       *pos = status->antenna;
-       pos++;
+       if (!status->chains) {
+               /* IEEE80211_RADIOTAP_ANTENNA */
+               *pos = status->antenna;
+               pos++;
+       }
 
        /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 
@@ -341,6 +371,11 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
                pos += 2;
        }
 
+       for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
+               *pos++ = status->chain_signal[chain];
+               *pos++ = chain;
+       }
+
        if (status->vendor_radiotap_len) {
                /* ensure 2 byte alignment for the vendor field as required */
                if ((pos - (u8 *)rthdr) & 1)