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>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 84d0bd5..68ef97f 100644 (file)
--- 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);

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index ee7839f..7b94beb 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1343,13 +1343,15 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size)
        struct mld2_report *pmr;
        struct in6_addr addr_buf;
        const struct in6_addr *saddr;
+       int hlen = LL_RESERVED_SPACE(dev);
+       int tlen = dev->needed_tailroom;
        int err;
        u8 ra[8] = { IPPROTO_ICMPV6, 0,
                     IPV6_TLV_ROUTERALERT, 2, 0, 0,
                     IPV6_TLV_PADN, 0 };
 
        /* we assume size > sizeof(ra) here */
-       size += LL_ALLOCATED_SPACE(dev);
+       size += hlen + tlen;
        /* limit our allocations to order-0 page */
        size = min_t(int, size, SKB_MAX_ORDER(0, 0));
        skb = sock_alloc_send_skb(sk, size, 1, &err);
@@ -1357,7 +1359,7 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size)
        if (!skb)
                return NULL;
 
-       skb_reserve(skb, LL_RESERVED_SPACE(dev));
+       skb_reserve(skb, hlen);
 
        if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
                /* <draft-ietf-magma-mld-source-05.txt>:
@@ -1723,6 +1725,8 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
        struct mld_msg *hdr;
        const struct in6_addr *snd_addr, *saddr;
        struct in6_addr addr_buf;
+       int hlen = LL_RESERVED_SPACE(dev);
+       int tlen = dev->needed_tailroom;
        int err, len, payload_len, full_len;
        u8 ra[8] = { IPPROTO_ICMPV6, 0,
                     IPV6_TLV_ROUTERALERT, 2, 0, 0,
@@ -1744,7 +1748,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
                      IPSTATS_MIB_OUT, full_len);
        rcu_read_unlock();
 
-       skb = sock_alloc_send_skb(sk, LL_ALLOCATED_SPACE(dev) + full_len, 1, &err);
+       skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err);
 
        if (skb == NULL) {
                rcu_read_lock();
@@ -1754,7 +1758,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
                return;
        }
 
-       skb_reserve(skb, LL_RESERVED_SPACE(dev));
+       skb_reserve(skb, hlen);
 
        if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
                /* <draft-ietf-magma-mld-source-05.txt>:

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 4a20982..d699ddc 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -446,6 +446,8 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev,
        struct sock *sk = net->ipv6.ndisc_sk;
        struct sk_buff *skb;
        struct icmp6hdr *hdr;
+       int hlen = LL_RESERVED_SPACE(dev);
+       int tlen = dev->needed_tailroom;
        int len;
        int err;
        u8 *opt;
@@ -459,7 +461,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev,
 
        skb = sock_alloc_send_skb(sk,
                                  (MAX_HEADER + sizeof(struct ipv6hdr) +
-                                  len + LL_ALLOCATED_SPACE(dev)),
+                                  len + hlen + tlen),
                                  1, &err);
        if (!skb) {
                ND_PRINTK0(KERN_ERR
@@ -468,7 +470,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev,
                return NULL;
        }
 
-       skb_reserve(skb, LL_RESERVED_SPACE(dev));
+       skb_reserve(skb, hlen);
        ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 
        skb->transport_header = skb->tail;
@@ -1533,6 +1535,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
        struct inet6_dev *idev;
        struct flowi6 fl6;
        u8 *opt;
+       int hlen, tlen;
        int rd_len;
        int err;
        u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
@@ -1590,9 +1593,11 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
        rd_len &= ~0x7;
        len += rd_len;
 
+       hlen = LL_RESERVED_SPACE(dev);
+       tlen = dev->needed_tailroom;
        buff = sock_alloc_send_skb(sk,
                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
-                                   len + LL_ALLOCATED_SPACE(dev)),
+                                   len + hlen + tlen),
                                   1, &err);
        if (buff == NULL) {
                ND_PRINTK0(KERN_ERR
@@ -1601,7 +1606,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
                goto release;
        }
 
-       skb_reserve(buff, LL_RESERVED_SPACE(dev));
+       skb_reserve(buff, hlen);
        ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
                   IPPROTO_ICMPV6, len);
 

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 204f2e8..a1aa869 100644 (file)
--- 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;