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[MAC80211]: allow drivers to indicate failed FCS/PLCP checksum

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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>
This commit is contained in:
Johannes Berg 2007-09-17 01:29:22 -04:00 committed by David S. Miller
parent ac630c2b19
commit 72abd81b98
2 changed files with 35 additions and 3 deletions
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6
include/net/mac80211.h
View file

@ -235,6 +235,10 @@ struct ieee80211_tx_control {
* @RX_FLAG_IV_STRIPPED: The IV/ICV are stripped from this frame.
* If this flag is set, the stack cannot do any replay detection
* hence the driver or hardware will have to do that.
* @RX_FLAG_FAILED_FCS_CRC: Set this flag if the FCS check failed on
* the frame.
* @RX_FLAG_FAILED_PLCP_CRC: Set this flag if the PCLP check failed on
* the frame.
*/
enum mac80211_rx_flags {
RX_FLAG_MMIC_ERROR = 1<<0,
@ -242,6 +246,8 @@ enum mac80211_rx_flags {
RX_FLAG_RADIOTAP = 1<<2,
RX_FLAG_MMIC_STRIPPED = 1<<3,
RX_FLAG_IV_STRIPPED = 1<<4,
RX_FLAG_FAILED_FCS_CRC = 1<<5,
RX_FLAG_FAILED_PLCP_CRC = 1<<6,
};
/**

32
net/mac80211/rx.c
View file

@ -145,6 +145,8 @@ ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
__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 @@ ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
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 @@ ieee80211_rx_h_monitor(struct ieee80211_txrx_data *rx)
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 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
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 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
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;