Only works if the IV was stripped from packets. Create a smaller
variant of ieee80211_rx_h_amsdu, which bypasses checks already done
within the fast-rx context.

Signed-off-by: Felix Fietkau <n...@nbd.name>
---
 net/mac80211/rx.c | 122 ++++++++++++++++++++++++++++++++----------------------
 1 file changed, 73 insertions(+), 49 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 5be957af4b0e..5ae1414ca550 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2353,39 +2353,17 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
 }
 
 static ieee80211_rx_result debug_noinline
-ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
+__ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
 {
        struct net_device *dev = rx->sdata->dev;
        struct sk_buff *skb = rx->skb;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        __le16 fc = hdr->frame_control;
        struct sk_buff_head frame_list;
-       struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
        struct ethhdr ethhdr;
        const u8 *check_da = ethhdr.h_dest, *check_sa = ethhdr.h_source;
 
-       if (unlikely(!ieee80211_is_data(fc)))
-               return RX_CONTINUE;
-
-       if (unlikely(!ieee80211_is_data_present(fc)))
-               return RX_DROP_MONITOR;
-
-       if (!(status->rx_flags & IEEE80211_RX_AMSDU))
-               return RX_CONTINUE;
-
        if (unlikely(ieee80211_has_a4(hdr->frame_control))) {
-               switch (rx->sdata->vif.type) {
-               case NL80211_IFTYPE_AP_VLAN:
-                       if (!rx->sdata->u.vlan.sta)
-                               return RX_DROP_UNUSABLE;
-                       break;
-               case NL80211_IFTYPE_STATION:
-                       if (!rx->sdata->u.mgd.use_4addr)
-                               return RX_DROP_UNUSABLE;
-                       break;
-               default:
-                       return RX_DROP_UNUSABLE;
-               }
                check_da = NULL;
                check_sa = NULL;
        } else switch (rx->sdata->vif.type) {
@@ -2405,9 +2383,6 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
                        break;
        }
 
-       if (is_multicast_ether_addr(hdr->addr1))
-               return RX_DROP_UNUSABLE;
-
        skb->dev = dev;
        __skb_queue_head_init(&frame_list);
 
@@ -2435,6 +2410,44 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
        return RX_QUEUED;
 }
 
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
+{
+       struct sk_buff *skb = rx->skb;
+       struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+       __le16 fc = hdr->frame_control;
+
+       if (!(status->rx_flags & IEEE80211_RX_AMSDU))
+               return RX_CONTINUE;
+
+       if (unlikely(!ieee80211_is_data(fc)))
+               return RX_CONTINUE;
+
+       if (unlikely(!ieee80211_is_data_present(fc)))
+               return RX_DROP_MONITOR;
+
+       if (unlikely(ieee80211_has_a4(hdr->frame_control))) {
+               switch (rx->sdata->vif.type) {
+               case NL80211_IFTYPE_AP_VLAN:
+                       if (!rx->sdata->u.vlan.sta)
+                               return RX_DROP_UNUSABLE;
+                       break;
+               case NL80211_IFTYPE_STATION:
+                       if (!rx->sdata->u.mgd.use_4addr)
+                               return RX_DROP_UNUSABLE;
+                       break;
+               default:
+                       return RX_DROP_UNUSABLE;
+               }
+       }
+
+       if (is_multicast_ether_addr(hdr->addr1))
+               return RX_DROP_UNUSABLE;
+
+       return __ieee80211_rx_h_amsdu(rx);
+}
+
 #ifdef CONFIG_MAC80211_MESH
 static ieee80211_rx_result
 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
@@ -3908,6 +3921,7 @@ static bool ieee80211_invoke_fast_rx(struct 
ieee80211_rx_data *rx,
                u8 sa[ETH_ALEN];
        } addrs __aligned(2);
        struct ieee80211_sta_rx_stats *stats = &sta->rx_stats;
+       int res;
 
        if (fast_rx->uses_rss)
                stats = this_cpu_ptr(sta->pcpu_rx_stats);
@@ -3929,10 +3943,6 @@ static bool ieee80211_invoke_fast_rx(struct 
ieee80211_rx_data *rx,
            (status->flag & FAST_RX_CRYPT_FLAGS) != FAST_RX_CRYPT_FLAGS)
                return false;
 
-       /* we don't deal with A-MSDU deaggregation here */
-       if (status->rx_flags & IEEE80211_RX_AMSDU)
-               return false;
-
        if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
                return false;
 
@@ -3960,25 +3970,31 @@ static bool ieee80211_invoke_fast_rx(struct 
ieee80211_rx_data *rx,
         * and strip the IV/MIC if necessary
         */
        if (fast_rx->key && !(status->flag & RX_FLAG_IV_STRIPPED)) {
+               if (status->rx_flags & IEEE80211_RX_AMSDU)
+                       return false;
+
                /* GCMP header length is the same */
                snap_offs += IEEE80211_CCMP_HDR_LEN;
        }
 
-       if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
-               goto drop;
-       payload = (void *)(skb->data + snap_offs);
+       if (!(status->rx_flags & IEEE80211_RX_AMSDU)) {
+               if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
+                       goto drop;
 
-       if (!ether_addr_equal(payload->snap, fast_rx->rfc1042_hdr))
-               return false;
+               payload = (void *)(skb->data + snap_offs);
 
-       /* Don't handle these here since they require special code.
-        * Accept AARP and IPX even though they should come with a
-        * bridge-tunnel header - but if we get them this way then
-        * there's little point in discarding them.
-        */
-       if (unlikely(payload->proto == cpu_to_be16(ETH_P_TDLS) ||
-                    payload->proto == fast_rx->control_port_protocol))
-               return false;
+               if (!ether_addr_equal(payload->snap, fast_rx->rfc1042_hdr))
+                       return false;
+
+               /* Don't handle these here since they require special code.
+                * Accept AARP and IPX even though they should come with a
+                * bridge-tunnel header - but if we get them this way then
+                * there's little point in discarding them.
+                */
+               if (unlikely(payload->proto == cpu_to_be16(ETH_P_TDLS) ||
+                            payload->proto == fast_rx->control_port_protocol))
+                       return false;
+       }
 
        /* after this point, don't punt to the slowpath! */
 
@@ -3992,12 +4008,6 @@ static bool ieee80211_invoke_fast_rx(struct 
ieee80211_rx_data *rx,
        }
 
        /* statistics part of ieee80211_rx_h_sta_process() */
-       stats->last_rx = jiffies;
-       stats->last_rate = sta_stats_encode_rate(status);
-
-       stats->fragments++;
-       stats->packets++;
-
        if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
                stats->last_signal = status->signal;
                if (!fast_rx->uses_rss)
@@ -4026,6 +4036,20 @@ static bool ieee80211_invoke_fast_rx(struct 
ieee80211_rx_data *rx,
        if (rx->key && !ieee80211_has_protected(hdr->frame_control))
                goto drop;
 
+       if (status->rx_flags & IEEE80211_RX_AMSDU) {
+               res = __ieee80211_rx_h_amsdu(rx);
+               if (res != RX_QUEUED)
+                       goto drop;
+
+               return true;
+       }
+
+       stats->last_rx = jiffies;
+       stats->last_rate = sta_stats_encode_rate(status);
+
+       stats->fragments++;
+       stats->packets++;
+
        /* do the header conversion - first grab the addresses */
        ether_addr_copy(addrs.da, skb->data + fast_rx->da_offs);
        ether_addr_copy(addrs.sa, skb->data + fast_rx->sa_offs);
-- 
2.14.2

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