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, 4 insertions, 2 deletions

diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index 7f17ba8b0318..915eb5265b2e 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -763,13 +763,15 @@ static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_d
         struct sk_buff *skb;
         struct bootp_pkt *b;
         struct iphdr *h;
+        int hlen = LL_RESERVED_SPACE(dev);
+        int tlen = dev->needed_tailroom;
 
         /* Allocate packet */
-        skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
+        skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
                         GFP_KERNEL);
         if (!skb)
                 return;
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
+        skb_reserve(skb, hlen);
         b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
         memset(b, 0, sizeof(struct bootp_pkt));