diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2142074d9fb09cad1297cddd69add23f632b3fd6..0094f3c0af64902fecbfee081135a12e6f4670ac 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -533,6 +533,59 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
}
}
+static struct sk_buff *
+ieee80211_make_monitor_skb(struct ieee80211_local *local,
+ struct sk_buff **origskb,
+ struct ieee80211_rate *rate,
+ int rtap_vendor_space, bool use_origskb)
+{
+ struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(*origskb);
+ int rt_hdrlen, needed_headroom;
+ struct sk_buff *skb;
+
+ /* room for the radiotap header based on driver features */
+ rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, *origskb);
+ needed_headroom = rt_hdrlen - rtap_vendor_space;
+
+ if (use_origskb) {
+ /* only need to expand headroom if necessary */
+ skb = *origskb;
+ *origskb = NULL;
+
+ /*
+ * This shouldn't trigger often because most devices have an
+ * RX header they pull before we get here, and that should
+ * be big enough for our radiotap information. We should
+ * probably export the length to drivers so that we can have
+ * them allocate enough headroom to start with.
+ */
+ if (skb_headroom(skb) < needed_headroom &&
+ pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
+ dev_kfree_skb(skb);
+ return NULL;
+ }
+ } else {
+ /*
+ * Need to make a copy and possibly remove radiotap header
+ * and FCS from the original.
+ */
+ skb = skb_copy_expand(*origskb, needed_headroom, 0, GFP_ATOMIC);
+
+ if (!skb)
+ return NULL;
+ }
+
+ /* prepend radiotap information */
+ ieee80211_add_rx_radiotap_header(local, skb, rate, rt_hdrlen, true);
+
+ skb_reset_mac_header(skb);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->pkt_type = PACKET_OTHERHOST;
+ skb->protocol = htons(ETH_P_802_2);
+
+ return skb;
+}
+
/*
* This function copies a received frame to all monitor interfaces and
* returns a cleaned-up SKB that no longer includes the FCS nor the
@@ -544,13 +597,12 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
struct ieee80211_sub_if_data *sdata;
- int rt_hdrlen, needed_headroom;
- struct sk_buff *skb, *skb2;
- struct net_device *prev_dev = NULL;
+ struct sk_buff *monskb = NULL;
int present_fcs_len = 0;
unsigned int rtap_vendor_space = 0;
struct ieee80211_sub_if_data *monitor_sdata =
rcu_dereference(local->monitor_sdata);
+ bool only_monitor = false;
if (unlikely(status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA)) {
struct ieee80211_vendor_radiotap *rtap = (void *)origskb->data;
@@ -583,9 +635,11 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
return NULL;
}
+ only_monitor = should_drop_frame(origskb, present_fcs_len,
+ rtap_vendor_space);
+
if (!local->monitors || (status->flag & RX_FLAG_SKIP_MONITOR)) {
- if (should_drop_frame(origskb, present_fcs_len,
- rtap_vendor_space)) {
+ if (only_monitor) {
dev_kfree_skb(origskb);
return NULL;
}
@@ -597,67 +651,46 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
ieee80211_handle_mu_mimo_mon(monitor_sdata, origskb, rtap_vendor_space);
- /* room for the radiotap header based on driver features */
- rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, origskb);
- needed_headroom = rt_hdrlen - rtap_vendor_space;
-
- if (should_drop_frame(origskb, present_fcs_len, rtap_vendor_space)) {
- /* only need to expand headroom if necessary */
- skb = origskb;
- origskb = NULL;
-
- /*
- * This shouldn't trigger often because most devices have an
- * RX header they pull before we get here, and that should
- * be big enough for our radiotap information. We should
- * probably export the length to drivers so that we can have
- * them allocate enough headroom to start with.
- */
- if (skb_headroom(skb) < needed_headroom &&
- pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
- dev_kfree_skb(skb);
- return NULL;
- }
- } else {
- /*
- * Need to make a copy and possibly remove radiotap header
- * and FCS from the original.
- */
- skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
- remove_monitor_info(origskb, present_fcs_len,
- rtap_vendor_space);
-
- if (!skb)
- return origskb;
- }
-
- /* prepend radiotap information */
- ieee80211_add_rx_radiotap_header(local, skb, rate, rt_hdrlen, true);
-
- skb_reset_mac_header(skb);
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- skb->pkt_type = PACKET_OTHERHOST;
- skb->protocol = htons(ETH_P_802_2);
-
list_for_each_entry_rcu(sdata, &local->mon_list, u.mntr.list) {
- if (prev_dev) {
- skb2 = skb_clone(skb, GFP_ATOMIC);
- if (skb2) {
- skb2->dev = prev_dev;
- netif_receive_skb(skb2);
+ bool last_monitor = list_is_last(&sdata->u.mntr.list,
+ &local->mon_list);
+
+ if (!monskb)
+ monskb = ieee80211_make_monitor_skb(local, &origskb,
+ rate,
+ rtap_vendor_space,
+ only_monitor &&
+ last_monitor);
+
+ if (monskb) {
+ struct sk_buff *skb;
+
+ if (last_monitor) {
+ skb = monskb;
+ monskb = NULL;
+ } else {
+ skb = skb_clone(monskb, GFP_ATOMIC);
+ }
+
+ if (skb) {
+ skb->dev = sdata->dev;
+ ieee80211_rx_stats(skb->dev, skb->len);
+ netif_receive_skb(skb);
}
}
- prev_dev = sdata->dev;
- ieee80211_rx_stats(sdata->dev, skb->len);
+ if (last_monitor)
+ break;
}
- if (prev_dev) {
- skb->dev = prev_dev;
- netif_receive_skb(skb);
- } else
- dev_kfree_skb(skb);
+ /* this happens if last_monitor was erroneously false */
+ dev_kfree_skb(monskb);
+
+ /* ditto */
+ if (!origskb)
+ return NULL;
+ remove_monitor_info(origskb, present_fcs_len, rtap_vendor_space);
return origskb;
}