From eeb0d56fab4cd7848cf2be6704fa48900dbc1381 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 14 Dec 2016 16:47:43 +0100 Subject: [PATCH] mac80211: implement multicast forwarding on fast-RX path In AP (or VLAN) mode, when unicast 802.11 packets are received, they might actually be multicast after conversion. In this case the fast-RX path didn't handle them properly to send them back to the wireless medium. Implement that by copying the SKB and sending it back out. The possible alternative would be to just punt the packet back to the regular (slow) RX path, but since we have almost all of the required code here already it's not so complicated to add here. Punting it back would also mean acquiring the spinlock, which would be bad for the stated purpose of the fast-RX path, to enable well-performing parallel RX. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 3e289a64ed43..c037c5bb6167 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -3942,21 +3942,31 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx, u64_stats_update_end(&stats->syncp); if (fast_rx->internal_forward) { - struct sta_info *dsta = sta_info_get(rx->sdata, skb->data); + struct sk_buff *xmit_skb = NULL; + bool multicast = is_multicast_ether_addr(skb->data); - if (dsta) { + if (multicast) { + xmit_skb = skb_copy(skb, GFP_ATOMIC); + } else if (sta_info_get(rx->sdata, skb->data)) { + xmit_skb = skb; + skb = NULL; + } + + if (xmit_skb) { /* * Send to wireless media and increase priority by 256 * to keep the received priority instead of * reclassifying the frame (see cfg80211_classify8021d). */ - skb->priority += 256; - skb->protocol = htons(ETH_P_802_3); - skb_reset_network_header(skb); - skb_reset_mac_header(skb); - dev_queue_xmit(skb); - return true; + xmit_skb->priority += 256; + xmit_skb->protocol = htons(ETH_P_802_3); + skb_reset_network_header(xmit_skb); + skb_reset_mac_header(xmit_skb); + dev_queue_xmit(xmit_skb); } + + if (!skb) + return true; } /* deliver to local stack */ -- 2.20.1