wireless: add ieee80211_amsdu_to_8023s

Move the A-MSDU handling code from mac80211 to cfg80211 so that more
drivers can use it. The new created function ieee80211_amsdu_to_8023s
converts an A-MSDU frame to a list of 802.3 frames.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0884b9a..542a477 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1578,7 +1578,7 @@ unsigned int ieee80211_hdrlen(__le16 fc);
  * @addr: the device MAC address
  * @iftype: the virtual interface type
  */
-int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
+int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                           enum nl80211_iftype iftype);
 
 /**
@@ -1589,10 +1589,28 @@ int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
  * @bssid: the network bssid (used only for iftype STATION and ADHOC)
  * @qos: build 802.11 QoS data frame
  */
-int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
+int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
                             enum nl80211_iftype iftype, u8 *bssid, bool qos);
 
 /**
+ * ieee80211_amsdu_to_8023s - decode an IEEE 802.11n A-MSDU frame
+ *
+ * Decode an IEEE 802.11n A-MSDU frame and convert it to a list of
+ * 802.3 frames. The @list will be empty if the decode fails. The
+ * @skb is consumed after the function returns.
+ *
+ * @skb: The input IEEE 802.11n A-MSDU frame.
+ * @list: The output list of 802.3 frames. It must be allocated and
+ *     initialized by by the caller.
+ * @addr: The device MAC address.
+ * @iftype: The device interface type.
+ * @extra_headroom: The hardware extra headroom for SKBs in the @list.
+ */
+void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
+                             const u8 *addr, enum nl80211_iftype iftype,
+                             const unsigned int extra_headroom);
+
+/**
  * cfg80211_classify8021d - determine the 802.1p/1d tag for a data frame
  * @skb: the data frame
  */

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index dbfd684..a182e42 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1541,16 +1541,10 @@ static ieee80211_rx_result debug_noinline
 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
 {
        struct net_device *dev = rx->sdata->dev;
-       struct ieee80211_local *local = rx->local;
-       u16 ethertype;
-       u8 *payload;
-       struct sk_buff *skb = rx->skb, *frame = NULL;
+       struct sk_buff *skb = rx->skb;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        __le16 fc = hdr->frame_control;
-       const struct ethhdr *eth;
-       int remaining, err;
-       u8 dst[ETH_ALEN];
-       u8 src[ETH_ALEN];
+       struct sk_buff_head frame_list;
 
        if (unlikely(!ieee80211_is_data(fc)))
                return RX_CONTINUE;
@@ -1561,94 +1555,34 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
        if (!(rx->flags & IEEE80211_RX_AMSDU))
                return RX_CONTINUE;
 
-       err = __ieee80211_data_to_8023(rx);
-       if (unlikely(err))
+       if (ieee80211_has_a4(hdr->frame_control) &&
+           rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+           !rx->sdata->u.vlan.sta)
                return RX_DROP_UNUSABLE;
 
-       skb->dev = dev;
-
-       dev->stats.rx_packets++;
-       dev->stats.rx_bytes += skb->len;
-
-       /* skip the wrapping header */
-       eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
-       if (!eth)
+       if (is_multicast_ether_addr(hdr->addr1) &&
+           ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+             rx->sdata->u.vlan.sta) ||
+            (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
+             rx->sdata->u.mgd.use_4addr)))
                return RX_DROP_UNUSABLE;
 
-       while (skb != frame) {
-               u8 padding;
-               __be16 len = eth->h_proto;
-               unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
-
-               remaining = skb->len;
-               memcpy(dst, eth->h_dest, ETH_ALEN);
-               memcpy(src, eth->h_source, ETH_ALEN);
+       skb->dev = dev;
+       __skb_queue_head_init(&frame_list);
 
-               padding = ((4 - subframe_len) & 0x3);
-               /* the last MSDU has no padding */
-               if (subframe_len > remaining)
-                       return RX_DROP_UNUSABLE;
+       ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
+                                rx->sdata->vif.type,
+                                rx->local->hw.extra_tx_headroom);
 
-               skb_pull(skb, sizeof(struct ethhdr));
-               /* if last subframe reuse skb */
-               if (remaining <= subframe_len + padding)
-                       frame = skb;
-               else {
-                       /*
-                        * Allocate and reserve two bytes more for payload
-                        * alignment since sizeof(struct ethhdr) is 14.
-                        */
-                       frame = dev_alloc_skb(
-                               ALIGN(local->hw.extra_tx_headroom, 4) +
-                               subframe_len + 2);
-
-                       if (frame == NULL)
-                               return RX_DROP_UNUSABLE;
-
-                       skb_reserve(frame,
-                                   ALIGN(local->hw.extra_tx_headroom, 4) +
-                                   sizeof(struct ethhdr) + 2);
-                       memcpy(skb_put(frame, ntohs(len)), skb->data,
-                               ntohs(len));
-
-                       eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
-                                                       padding);
-                       if (!eth) {
-                               dev_kfree_skb(frame);
-                               return RX_DROP_UNUSABLE;
-                       }
-               }
-
-               skb_reset_network_header(frame);
-               frame->dev = dev;
-               frame->priority = skb->priority;
-               rx->skb = frame;
-
-               payload = frame->data;
-               ethertype = (payload[6] << 8) | payload[7];
-
-               if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
-                           ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
-                          compare_ether_addr(payload,
-                                             bridge_tunnel_header) == 0)) {
-                       /* remove RFC1042 or Bridge-Tunnel
-                        * encapsulation and replace EtherType */
-                       skb_pull(frame, 6);
-                       memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
-                       memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
-               } else {
-                       memcpy(skb_push(frame, sizeof(__be16)),
-                              &len, sizeof(__be16));
-                       memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
-                       memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
-               }
+       while (!skb_queue_empty(&frame_list)) {
+               rx->skb = __skb_dequeue(&frame_list);
 
                if (!ieee80211_frame_allowed(rx, fc)) {
-                       if (skb == frame) /* last frame */
-                               return RX_DROP_UNUSABLE;
-                       dev_kfree_skb(frame);
+                       dev_kfree_skb(rx->skb);
                        continue;
                }
+               dev->stats.rx_packets++;
+               dev->stats.rx_bytes += rx->skb->len;
 
                ieee80211_deliver_skb(rx);
        }

diff --git a/net/wireless/util.c b/net/wireless/util.c
index a3c841a..23557c1 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -285,7 +285,7 @@ static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
        }
 }
 
-int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
+int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                           enum nl80211_iftype iftype)
 {
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
@@ -383,7 +383,7 @@ int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
 }
 EXPORT_SYMBOL(ieee80211_data_to_8023);
 
-int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
+int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
                             enum nl80211_iftype iftype, u8 *bssid, bool qos)
 {
        struct ieee80211_hdr hdr;
@@ -497,6 +497,101 @@ int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
 }
 EXPORT_SYMBOL(ieee80211_data_from_8023);
 
+
+void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
+                             const u8 *addr, enum nl80211_iftype iftype,
+                             const unsigned int extra_headroom)
+{
+       struct sk_buff *frame = NULL;
+       u16 ethertype;
+       u8 *payload;
+       const struct ethhdr *eth;
+       int remaining, err;
+       u8 dst[ETH_ALEN], src[ETH_ALEN];
+
+       err = ieee80211_data_to_8023(skb, addr, iftype);
+       if (err)
+               goto out;
+
+       /* skip the wrapping header */
+       eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
+       if (!eth)
+               goto out;
+
+       while (skb != frame) {
+               u8 padding;
+               __be16 len = eth->h_proto;
+               unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
+
+               remaining = skb->len;
+               memcpy(dst, eth->h_dest, ETH_ALEN);
+               memcpy(src, eth->h_source, ETH_ALEN);
+
+               padding = (4 - subframe_len) & 0x3;
+               /* the last MSDU has no padding */
+               if (subframe_len > remaining)
+                       goto purge;
+
+               skb_pull(skb, sizeof(struct ethhdr));
+               /* reuse skb for the last subframe */
+               if (remaining <= subframe_len + padding)
+                       frame = skb;
+               else {
+                       unsigned int hlen = ALIGN(extra_headroom, 4);
+                       /*
+                        * Allocate and reserve two bytes more for payload
+                        * alignment since sizeof(struct ethhdr) is 14.
+                        */
+                       frame = dev_alloc_skb(hlen + subframe_len + 2);
+                       if (!frame)
+                               goto purge;
+
+                       skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
+                       memcpy(skb_put(frame, ntohs(len)), skb->data,
+                               ntohs(len));
+
+                       eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
+                                                       padding);
+                       if (!eth) {
+                               dev_kfree_skb(frame);
+                               goto purge;
+                       }
+               }
+
+               skb_reset_network_header(frame);
+               frame->dev = skb->dev;
+               frame->priority = skb->priority;
+
+               payload = frame->data;
+               ethertype = (payload[6] << 8) | payload[7];
+
+               if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
+                           ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
+                          compare_ether_addr(payload,
+                                             bridge_tunnel_header) == 0)) {
+                       /* remove RFC1042 or Bridge-Tunnel
+                        * encapsulation and replace EtherType */
+                       skb_pull(frame, 6);
+                       memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
+                       memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
+               } else {
+                       memcpy(skb_push(frame, sizeof(__be16)), &len,
+                               sizeof(__be16));
+                       memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
+                       memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
+               }
+               __skb_queue_tail(list, frame);
+       }
+
+       return;
+
+ purge:
+       __skb_queue_purge(list);
+ out:
+       dev_kfree_skb(skb);
+}
+EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
+
 /* Given a data frame determine the 802.1p/1d tag to use. */
 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
 {