ipv4: Remove all uses of LL_ALLOCATED_SPACE

ipv4: 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/ipv4
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, 5 insertions, 2 deletions

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 7a8410d1b4b1..3ccda5ae8a27 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -328,6 +328,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
         unsigned int iphlen;
         int err;
         struct rtable *rt = *rtp;
+        int hlen, tlen;
 
         if (length > rt->dst.dev->mtu) {
                 ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,
@@ -337,12 +338,14 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
         if (flags&MSG_PROBE)
                 goto out;
 
+        hlen = LL_RESERVED_SPACE(rt->dst.dev);
+        tlen = rt->dst.dev->needed_tailroom;
         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;