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>

4 files changed, 22 insertions, 10 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index d732827b32b9..5c29ac5b0c3a 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -592,16 +592,18 @@ struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
         struct sk_buff *skb;
         struct arphdr *arp;
         unsigned char *arp_ptr;
+        int hlen = LL_RESERVED_SPACE(dev);
+        int tlen = dev->needed_tailroom;
 
         /*
          *      Allocate a buffer
          */
 
-        skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
+        skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC);
         if (skb == NULL)
                 return NULL;
 
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
+        skb_reserve(skb, hlen);
         skb_reset_network_header(skb);
         arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
         skb->dev = dev;
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index c7472eff2d51..fbc53767bf35 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -304,9 +304,11 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
         struct igmpv3_report *pig;
         struct net *net = dev_net(dev);
         struct flowi4 fl4;
+        int hlen = LL_RESERVED_SPACE(dev);
+        int tlen = dev->needed_tailroom;
 
         while (1) {
-                skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev),
+                skb = alloc_skb(size + hlen + tlen,
                                 GFP_ATOMIC | __GFP_NOWARN);
                 if (skb)
                         break;
@@ -327,7 +329,7 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
         skb_dst_set(skb, &rt->dst);
         skb->dev = dev;
 
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
+        skb_reserve(skb, hlen);
 
         skb_reset_network_header(skb);
         pip = ip_hdr(skb);
@@ -647,6 +649,7 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
         __be32  group = pmc ? pmc->multiaddr : 0;
         struct flowi4 fl4;
         __be32  dst;
+        int hlen, tlen;
 
         if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
                 return igmpv3_send_report(in_dev, pmc);
@@ -661,7 +664,9 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
         if (IS_ERR(rt))
                 return -1;
 
-        skb = alloc_skb(IGMP_SIZE+LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
+        hlen = LL_RESERVED_SPACE(dev);
+        tlen = dev->needed_tailroom;
+        skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
         if (skb == NULL) {
                 ip_rt_put(rt);
                 return -1;
@@ -669,7 +674,7 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
 
         skb_dst_set(skb, &rt->dst);
 
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
+        skb_reserve(skb, hlen);
 
         skb_reset_network_header(skb);
         iph = ip_hdr(skb);
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));
 
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;