mac80211: Add cooked monitor mode support
This adds "cooked" monitor mode to mac80211. A monitor interface
in "cooked" mode will see all frames that mac80211 has not used
internally.
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 78fd918..91f06c3 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -239,6 +239,11 @@
/* no need to tell driver */
break;
case IEEE80211_IF_TYPE_MNTR:
+ if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
+ local->cooked_mntrs++;
+ break;
+ }
+
/* must be before the call to ieee80211_configure_filter */
local->monitors++;
if (local->monitors == 1)
@@ -370,6 +375,11 @@
/* no need to tell driver */
break;
case IEEE80211_IF_TYPE_MNTR:
+ if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
+ local->cooked_mntrs--;
+ break;
+ }
+
local->monitors--;
if (local->monitors == 0)
local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
@@ -1177,7 +1187,7 @@
u16 frag, type;
struct ieee80211_tx_status_rtap_hdr *rthdr;
struct ieee80211_sub_if_data *sdata;
- int monitors;
+ struct net_device *prev_dev = NULL;
if (!status) {
printk(KERN_ERR
@@ -1290,7 +1300,11 @@
/* this was a transmitted frame, but now we want to reuse it */
skb_orphan(skb);
- if (!local->monitors) {
+ /*
+ * This is a bit racy but we can avoid a lot of work
+ * with this test...
+ */
+ if (!local->monitors && !local->cooked_mntrs) {
dev_kfree_skb(skb);
return;
}
@@ -1324,42 +1338,37 @@
rthdr->data_retries = status->retry_count;
- rcu_read_lock();
- monitors = local->monitors;
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- /*
- * Using the monitors counter is possibly racy, but
- * if the value is wrong we simply either clone the skb
- * once too much or forget sending it to one monitor iface
- * The latter case isn't nice but fixing the race is much
- * more complicated.
- */
- if (!monitors || !skb)
- goto out;
+ /* XXX: is this sufficient for BPF? */
+ skb_set_mac_header(skb, 0);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->pkt_type = PACKET_OTHERHOST;
+ skb->protocol = htons(ETH_P_802_2);
+ memset(skb->cb, 0, sizeof(skb->cb));
+ rcu_read_lock();
+ list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR) {
if (!netif_running(sdata->dev))
continue;
- monitors--;
- if (monitors)
+
+ if (prev_dev) {
skb2 = skb_clone(skb, GFP_ATOMIC);
- else
- skb2 = NULL;
- skb->dev = sdata->dev;
- /* XXX: is this sufficient for BPF? */
- skb_set_mac_header(skb, 0);
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- skb->pkt_type = PACKET_OTHERHOST;
- skb->protocol = htons(ETH_P_802_2);
- memset(skb->cb, 0, sizeof(skb->cb));
- netif_rx(skb);
- skb = skb2;
+ if (skb2) {
+ skb2->dev = prev_dev;
+ netif_rx(skb2);
+ }
+ }
+
+ prev_dev = sdata->dev;
}
}
- out:
+ if (prev_dev) {
+ skb->dev = prev_dev;
+ netif_rx(skb);
+ skb = NULL;
+ }
rcu_read_unlock();
- if (skb)
- dev_kfree_skb(skb);
+ dev_kfree_skb(skb);
}
EXPORT_SYMBOL(ieee80211_tx_status);
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1129a42..1b4a449 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -131,6 +131,7 @@
#define IEEE80211_TXRXD_RXRA_MATCH BIT(5)
#define IEEE80211_TXRXD_TX_INJECTED BIT(6)
#define IEEE80211_TXRXD_RX_AMSDU BIT(7)
+#define IEEE80211_TXRXD_RX_CMNTR_REPORTED BIT(8)
struct ieee80211_txrx_data {
struct sk_buff *skb;
struct net_device *dev;
@@ -419,7 +420,7 @@
struct net_device *mdev; /* wmaster# - "master" 802.11 device */
int open_count;
- int monitors;
+ int monitors, cooked_mntrs;
/* number of interfaces with corresponding FIF_ flags */
int fif_fcsfail, fif_plcpfail, fif_control, fif_other_bss;
unsigned int filter_flags; /* FIF_* */
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3a3112f..b1fc112 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -223,6 +223,9 @@
if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
continue;
+ if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
+ continue;
+
if (prev_dev) {
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2) {
@@ -1520,6 +1523,86 @@
rx->skb = NULL;
}
+static void ieee80211_rx_cooked_monitor(struct ieee80211_txrx_data *rx)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_local *local = rx->local;
+ struct ieee80211_rtap_hdr {
+ struct ieee80211_radiotap_header hdr;
+ u8 flags;
+ u8 rate;
+ __le16 chan_freq;
+ __le16 chan_flags;
+ } __attribute__ ((packed)) *rthdr;
+ struct sk_buff *skb = rx->skb, *skb2;
+ struct net_device *prev_dev = NULL;
+ struct ieee80211_rx_status *status = rx->u.rx.status;
+
+ if (rx->flags & IEEE80211_TXRXD_RX_CMNTR_REPORTED)
+ goto out_free_skb;
+
+ if (skb_headroom(skb) < sizeof(*rthdr) &&
+ pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
+ goto out_free_skb;
+
+ 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 =
+ cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
+ (1 << IEEE80211_RADIOTAP_RATE) |
+ (1 << IEEE80211_RADIOTAP_CHANNEL));
+
+ rthdr->rate = rx->u.rx.rate->bitrate / 5;
+ rthdr->chan_freq = cpu_to_le16(status->freq);
+
+ if (status->band == IEEE80211_BAND_5GHZ)
+ rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
+ IEEE80211_CHAN_5GHZ);
+ else
+ rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
+ IEEE80211_CHAN_2GHZ);
+
+ skb_set_mac_header(skb, 0);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->pkt_type = PACKET_OTHERHOST;
+ skb->protocol = htons(ETH_P_802_2);
+
+ list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+ if (!netif_running(sdata->dev))
+ continue;
+
+ if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
+ !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
+ continue;
+
+ if (prev_dev) {
+ skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (skb2) {
+ skb2->dev = prev_dev;
+ netif_rx(skb2);
+ }
+ }
+
+ prev_dev = sdata->dev;
+ sdata->dev->stats.rx_packets++;
+ sdata->dev->stats.rx_bytes += skb->len;
+ }
+
+ if (prev_dev) {
+ skb->dev = prev_dev;
+ netif_rx(skb);
+ skb = NULL;
+ } else
+ goto out_free_skb;
+
+ rx->flags |= IEEE80211_TXRXD_RX_CMNTR_REPORTED;
+ return;
+
+ out_free_skb:
+ dev_kfree_skb(skb);
+}
+
typedef ieee80211_rx_result (*ieee80211_rx_handler)(struct ieee80211_txrx_data *);
static ieee80211_rx_handler ieee80211_rx_handlers[] =
{
@@ -1574,9 +1657,11 @@
}
switch (res) {
- case RX_DROP_MONITOR:
- case RX_DROP_UNUSABLE:
case RX_CONTINUE:
+ case RX_DROP_MONITOR:
+ ieee80211_rx_cooked_monitor(rx);
+ break;
+ case RX_DROP_UNUSABLE:
dev_kfree_skb(rx->skb);
break;
}