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/net/wireless/util.c b/net/wireless/util.c
index a3c841a2..23557c1 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -285,7 +285,7 @@
}
}
-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 @@
}
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 @@
}
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)
{