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.

In order to do so, update cfg80211's ieee80211_data_to_8023_exthdr()
to take the offset between header and snap.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 56e905c..fc40843 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4410,10 +4410,12 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
  *     of it being pushed into the SKB
  * @addr: the device MAC address
  * @iftype: the virtual interface type
+ * @data_offset: offset of payload after the 802.11 header
  * Return: 0 on success. Non-zero on error.
  */
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
-                                 const u8 *addr, enum nl80211_iftype iftype);
+                                 const u8 *addr, enum nl80211_iftype iftype,
+                                 u8 data_offset);
 
 /**
  * ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3
@@ -4425,7 +4427,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 static inline int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                                         enum nl80211_iftype iftype)
 {
-       return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype);
+       return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0);
 }
 
 /**

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2783c5c..de7d107 100644 (file)
--- 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, u8 data_offset)
 {
        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) {
@@ -2405,15 +2383,13 @@ 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);
 
        if (ieee80211_data_to_8023_exthdr(skb, &ethhdr,
                                          rx->sdata->vif.addr,
-                                         rx->sdata->vif.type))
+                                         rx->sdata->vif.type,
+                                         data_offset))
                return RX_DROP_UNUSABLE;
 
        ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
@@ -2435,6 +2411,44 @@ 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, 0);
+}
+
 #ifdef CONFIG_MAC80211_MESH
 static ieee80211_rx_result
 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
@@ -3898,7 +3912,8 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
        struct sta_info *sta = rx->sta;
        int orig_len = skb->len;
-       int snap_offs = ieee80211_hdrlen(hdr->frame_control);
+       int hdrlen = ieee80211_hdrlen(hdr->frame_control);
+       int snap_offs = hdrlen;
        struct {
                u8 snap[sizeof(rfc1042_header)];
                __be16 proto;
@@ -3929,10 +3944,6 @@ 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;
 
@@ -3964,21 +3975,24 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
                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 +4006,6 @@ 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 +4034,20 @@ 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) {
+               if (__ieee80211_rx_h_amsdu(rx, snap_offs - hdrlen) !=
+                   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);

diff --git a/net/wireless/util.c b/net/wireless/util.c
index c691606..d112e9a 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -420,7 +420,8 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
 EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);
 
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
-                                 const u8 *addr, enum nl80211_iftype iftype)
+                                 const u8 *addr, enum nl80211_iftype iftype,
+                                 u8 data_offset)
 {
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        struct {
@@ -434,7 +435,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
        if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
                return -1;
 
-       hdrlen = ieee80211_hdrlen(hdr->frame_control);
+       hdrlen = ieee80211_hdrlen(hdr->frame_control) + data_offset;
        if (skb->len < hdrlen + 8)
                return -1;