mac80211: support paged rx SKBs

Mac80211 drivers can now pass paged SKBs to mac80211 via
ieee80211_rx{_irqsafe}. The implementation currently use
skb_linearize() in a few places i.e. management frame
handling, software decryption, defragmentation and A-MSDU
process. We will optimize them one by one later.

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

1 files changed, 18 insertions, 6 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index be2ab8c59e3a..7acb81b9675d 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -330,11 +330,18 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                 if (iftype == NL80211_IFTYPE_MESH_POINT) {
                         struct ieee80211s_hdr *meshdr =
                                 (struct ieee80211s_hdr *) (skb->data + hdrlen);
-                        hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
+                        /* make sure meshdr->flags is on the linear part */
+                        if (!pskb_may_pull(skb, hdrlen + 1))
+                                return -1;
                         if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
-                                memcpy(dst, meshdr->eaddr1, ETH_ALEN);
-                                memcpy(src, meshdr->eaddr2, ETH_ALEN);
+                                skb_copy_bits(skb, hdrlen +
+                                        offsetof(struct ieee80211s_hdr, eaddr1),
+                                        dst, ETH_ALEN);
+                                skb_copy_bits(skb, hdrlen +
+                                        offsetof(struct ieee80211s_hdr, eaddr2),
+                                        src, ETH_ALEN);
                         }
+                        hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
                 }
                 break;
         case cpu_to_le16(IEEE80211_FCTL_FROMDS):
@@ -346,9 +353,14 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                 if (iftype == NL80211_IFTYPE_MESH_POINT) {
                         struct ieee80211s_hdr *meshdr =
                                 (struct ieee80211s_hdr *) (skb->data + hdrlen);
-                        hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
+                        /* make sure meshdr->flags is on the linear part */
+                        if (!pskb_may_pull(skb, hdrlen + 1))
+                                return -1;
                         if (meshdr->flags & MESH_FLAGS_AE_A4)
-                                memcpy(src, meshdr->eaddr1, ETH_ALEN);
+                                skb_copy_bits(skb, hdrlen +
+                                        offsetof(struct ieee80211s_hdr, eaddr1),
+                                        src, ETH_ALEN);
+                        hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
                 }
                 break;
         case cpu_to_le16(0):
@@ -357,7 +369,7 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                 break;
         }
 
-        if (unlikely(skb->len - hdrlen < 8))
+        if (!pskb_may_pull(skb, hdrlen + 8))
                 return -1;
 
         payload = skb->data + hdrlen;