From a7ae1992248e5cf9dc5bd35695ab846d27efe15f Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 18 Nov 2011 02:20:04 +0000 Subject: 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 Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/ipv6/ip6_output.c') diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 84d0bd5cac93..68ef97f353b6 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -631,6 +631,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) struct ipv6hdr *tmp_hdr; struct frag_hdr *fh; unsigned int mtu, hlen, left, len; + int hroom, troom; __be32 frag_id = 0; int ptr, offset = 0, err=0; u8 *prevhdr, nexthdr = 0; @@ -797,6 +798,8 @@ slow_path: */ *prevhdr = NEXTHDR_FRAGMENT; + hroom = LL_RESERVED_SPACE(rt->dst.dev); + troom = rt->dst.dev->needed_tailroom; /* * Keep copying data until we run out. @@ -815,7 +818,8 @@ slow_path: * Allocate buffer. */ - if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->dst.dev), GFP_ATOMIC)) == NULL) { + if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + + hroom + troom, GFP_ATOMIC)) == NULL) { NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); @@ -828,7 +832,7 @@ slow_path: */ ip6_copy_metadata(frag, skb); - skb_reserve(frag, LL_RESERVED_SPACE(rt->dst.dev)); + skb_reserve(frag, hroom); skb_put(frag, len + hlen + sizeof(struct frag_hdr)); skb_reset_network_header(frag); fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); -- cgit v1.2.3