ipv6: Remove all uses of LL_ALLOCATED_SPACE

ipv6: Remove all uses of LL_ALLOCATED_SPACE

The macro LL_ALLOCATED_SPACE was ill-conceived.  It applies the
alignment to the sum of needed_headroom and needed_tailroom.  As
the amount that is then reserved for head room is needed_headroom
with alignment, this means that the tail room left may be too small.

This patch replaces all uses of LL_ALLOCATED_SPACE in net/ipv6
with the macro LL_RESERVED_SPACE and direct reference to
needed_tailroom.

This also fixes the problem with needed_headroom changing between
allocating the skb and reserving the head room.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 204f2e833f04..a1aa869a9ce7 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -611,6 +611,8 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
         struct sk_buff *skb;
         int err;
         struct rt6_info *rt = (struct rt6_info *)*dstp;
+        int hlen = LL_RESERVED_SPACE(rt->dst.dev);
+        int tlen = rt->dst.dev->needed_tailroom;
 
         if (length > rt->dst.dev->mtu) {
                 ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);
@@ -620,11 +622,11 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
                 goto out;
 
         skb = sock_alloc_send_skb(sk,
-                                  length + LL_ALLOCATED_SPACE(rt->dst.dev) + 15,
+                                  length + hlen + tlen + 15,
                                   flags & MSG_DONTWAIT, &err);
         if (skb == NULL)
                 goto error;
-        skb_reserve(skb, LL_RESERVED_SPACE(rt->dst.dev));
+        skb_reserve(skb, hlen);
 
         skb->priority = sk->sk_priority;
         skb->mark = sk->sk_mark;