ipv6: Remove all uses of LL_ALLOCATED_SPACE

commit a7ae1992248e5cf9dc5bd35695ab846d27efe15f upstream.

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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 46fc6a3..2215d6b 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -623,6 +623,7 @@ 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;
        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;
        __be32 frag_id = 0;
        int ptr, offset = 0, err=0;
        u8 *prevhdr, nexthdr = 0;


@@ -789,6 +790,8 @@ slow_path:
         */
 
        *prevhdr = NEXTHDR_FRAGMENT;
         */
 
        *prevhdr = NEXTHDR_FRAGMENT;

+       hroom = LL_RESERVED_SPACE(rt->dst.dev);
+       troom = rt->dst.dev->needed_tailroom;

 
        /*
         *      Keep copying data until we run out.
 
        /*
         *      Keep copying data until we run out.


@@ -807,7 +810,8 @@ slow_path:
                 *      Allocate buffer.
                 */
 
                 *      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);
                        NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
                        IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
                                      IPSTATS_MIB_FRAGFAILS);


@@ -820,7 +824,7 @@ slow_path:
                 */
 
                ip6_copy_metadata(frag, skb);
                 */
 
                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);
                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 4f12b66..008ffa7 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1343,13 +1343,15 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, int size)
        struct mld2_report *pmr;
        struct in6_addr addr_buf;
        const struct in6_addr *saddr;
        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 */
        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);
        /* 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 inet6_dev *idev, int size)
        if (!skb)
                return NULL;
 
        if (!skb)
                return NULL;
 

-       skb_reserve(skb, LL_RESERVED_SPACE(dev));
+       skb_reserve(skb, hlen);

 
        if (__ipv6_get_lladdr(idev, &addr_buf, IFA_F_TENTATIVE)) {
                /* <draft-ietf-magma-mld-source-05.txt>:
 
        if (__ipv6_get_lladdr(idev, &addr_buf, IFA_F_TENTATIVE)) {
                /* <draft-ietf-magma-mld-source-05.txt>:


@@ -1725,6 +1727,8 @@ 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;
        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,
        int err, len, payload_len, full_len;
        u8 ra[8] = { IPPROTO_ICMPV6, 0,
                     IPV6_TLV_ROUTERALERT, 2, 0, 0,


@@ -1746,7 +1750,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
                      IPSTATS_MIB_OUT, full_len);
        rcu_read_unlock();
 
                      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();
 
        if (skb == NULL) {
                rcu_read_lock();


@@ -1756,7 +1760,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
                return;
        }
 
                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>:
 
        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 bc55358..62096d8 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;
        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;
        u8 *opt;
 
        int len;
        u8 *opt;
 


@@ -457,7 +459,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev,
                len += ndisc_opt_addr_space(dev);
 
        skb = alloc_skb((MAX_HEADER + sizeof(struct ipv6hdr) +
                len += ndisc_opt_addr_space(dev);
 
        skb = alloc_skb((MAX_HEADER + sizeof(struct ipv6hdr) +

-                        len + LL_ALLOCATED_SPACE(dev)), GFP_ATOMIC);
+                        len + hlen + tlen), GFP_ATOMIC);

        if (!skb) {
                ND_PRINTK0(KERN_ERR
                           "ICMPv6 ND: %s() failed to allocate an skb.\n",
        if (!skb) {
                ND_PRINTK0(KERN_ERR
                           "ICMPv6 ND: %s() failed to allocate an skb.\n",


@@ -465,7 +467,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev,
                return NULL;
        }
 
                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;
        ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 
        skb->transport_header = skb->tail;


@@ -1534,6 +1536,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
        struct inet6_dev *idev;
        struct flowi6 fl6;
        u8 *opt;
        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;
        int rd_len;
        int err;
        u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;


@@ -1591,9 +1594,11 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
        rd_len &= ~0x7;
        len += rd_len;
 
        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) +
        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
                                   1, &err);
        if (buff == NULL) {
                ND_PRINTK0(KERN_ERR


@@ -1602,7 +1607,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
                goto release;
        }
 
                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);
 
        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 9ecbc84..9287f3e 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -607,6 +607,8 @@ 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;
        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);
 
        if (length > rt->dst.dev->mtu) {
                ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);


@@ -616,11 +618,11 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
                goto out;
 
        skb = sock_alloc_send_skb(sk,
                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;
                                  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;
 
        skb->priority = sk->sk_priority;
        skb->mark = sk->sk_mark;