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>
This commit is contained in:
Herbert Xu 2011-11-18 02:20:04 +00:00 committed by David S. Miller
parent 505a467b66
commit 6608824329
4 changed files with 22 additions and 10 deletions

View file

@ -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;

View file

@ -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);

View file

@ -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));

View file

@ -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;