[MAC80211]: allow drivers to indicate failed FCS/PLCP checksum
This patch allows drivers to indicate bad FCS/PLCP CRC to the stack and
have the stack drop packets like that except for monitor interfaces.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e9dcc62..cf2a72f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -145,6 +145,8 @@
__le16 chan_freq;
__le16 chan_flags;
u8 antsignal;
+ u8 padding_for_rxflags;
+ __le16 rx_flags;
} __attribute__ ((packed)) *rthdr;
skb->dev = dev;
@@ -167,12 +169,21 @@
cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
(1 << IEEE80211_RADIOTAP_RATE) |
(1 << IEEE80211_RADIOTAP_CHANNEL) |
- (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL));
+ (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;
+
+ /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
+ rthdr->rx_flags = 0;
+ if (status->flag &
+ (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
+ rthdr->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;
+
rthdr->chan_freq = cpu_to_le16(status->freq);
rthdr->chan_flags =
status->phymode == MODE_IEEE80211A ?
@@ -200,6 +211,15 @@
return TXRX_QUEUED;
}
+ /*
+ * Drop frames with failed FCS/PLCP checksums here, they are only
+ * relevant for monitor mode, the rest of the stack should never
+ * see them.
+ */
+ if (rx->u.rx.status->flag &
+ (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
+ return TXRX_DROP;
+
if (rx->u.rx.status->flag & RX_FLAG_RADIOTAP)
skb_pull(rx->skb, ieee80211_get_radiotap_len(rx->skb->data));
@@ -1360,6 +1380,7 @@
struct ieee80211_sub_if_data *prev = NULL;
struct sk_buff *skb_new;
u8 *bssid;
+ int bogon;
if (status->flag & RX_FLAG_RADIOTAP) {
radiotap_len = ieee80211_get_radiotap_len(skb->data);
@@ -1380,10 +1401,15 @@
rx.u.rx.status = status;
rx.fc = skb->len >= 2 ? le16_to_cpu(hdr->frame_control) : 0;
type = rx.fc & IEEE80211_FCTL_FTYPE;
- if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
+
+ bogon = status->flag & (RX_FLAG_FAILED_FCS_CRC |
+ RX_FLAG_FAILED_PLCP_CRC);
+
+ if (!bogon && (type == IEEE80211_FTYPE_DATA ||
+ type == IEEE80211_FTYPE_MGMT))
local->dot11ReceivedFragmentCount++;
- if (skb->len >= 16) {
+ if (!bogon && skb->len >= 16) {
sta = rx.sta = sta_info_get(local, hdr->addr2);
if (sta) {
rx.dev = rx.sta->dev;