mac80211: add an optimization for fast-rx support

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/package/kernel/mac80211/patches/335-mac80211-support-A-MSDU-in-fast-rx.patch b/package/kernel/mac80211/patches/335-mac80211-support-A-MSDU-in-fast-rx.patch
new file mode 100644 (file)
index 0000000..dce6d5c
--- /dev/null
+++ b/package/kernel/mac80211/patches/335-mac80211-support-A-MSDU-in-fast-rx.patch
@@ -0,0 +1,207 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Mon, 26 Feb 2018 22:09:29 +0100
+Subject: [PATCH] mac80211: support A-MSDU in fast-rx
+
+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 <nbd@nbd.name>
+---
+
+--- a/net/mac80211/rx.c
++++ b/net/mac80211/rx.c
+@@ -2358,39 +2358,17 @@ ieee80211_deliver_skb(struct ieee80211_r
+ }
+ 
+ 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) {
+@@ -2410,9 +2388,6 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx
+                       break;
+       }
+ 
+-      if (is_multicast_ether_addr(hdr->addr1))
+-              return RX_DROP_UNUSABLE;
+-
+       skb->dev = dev;
+       __skb_queue_head_init(&frame_list);
+ 
+@@ -2440,6 +2415,44 @@ ieee80211_rx_h_amsdu(struct ieee80211_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 CPTCFG_MAC80211_MESH
+ static ieee80211_rx_result
+ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
+@@ -3899,6 +3912,7 @@ static bool ieee80211_invoke_fast_rx(str
+               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);
+@@ -3920,10 +3934,6 @@ static bool ieee80211_invoke_fast_rx(str
+           (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;
+ 
+@@ -3951,25 +3961,31 @@ static bool ieee80211_invoke_fast_rx(str
+        * 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! */
+ 
+@@ -3983,12 +3999,6 @@ static bool ieee80211_invoke_fast_rx(str
+       }
+ 
+       /* 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)
+@@ -4017,6 +4027,20 @@ static bool ieee80211_invoke_fast_rx(str
+       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);