act_nat: fix on the TX path

On the TX path, skb->data points to the ethernet header, not the network
header. So when validating the packet length for accessing we should
take the ethernet header into account.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Changli Gao 2010-08-03 17:39:18 +00:00 committed by David S. Miller
parent c33788b45f
commit 36d12690a2
1 changed files with 13 additions and 10 deletions

View File

@ -114,6 +114,7 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
int egress;
int action;
int ihl;
int noff;
spin_lock(&p->tcf_lock);
@ -132,7 +133,8 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
if (unlikely(action == TC_ACT_SHOT))
goto drop;
if (!pskb_may_pull(skb, sizeof(*iph)))
noff = skb_network_offset(skb);
if (!pskb_may_pull(skb, sizeof(*iph) + noff))
goto drop;
iph = ip_hdr(skb);
@ -144,7 +146,7 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
if (!((old_addr ^ addr) & mask)) {
if (skb_cloned(skb) &&
!skb_clone_writable(skb, sizeof(*iph)) &&
!skb_clone_writable(skb, sizeof(*iph) + noff) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto drop;
@ -172,9 +174,9 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
{
struct tcphdr *tcph;
if (!pskb_may_pull(skb, ihl + sizeof(*tcph)) ||
if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) ||
(skb_cloned(skb) &&
!skb_clone_writable(skb, ihl + sizeof(*tcph)) &&
!skb_clone_writable(skb, ihl + sizeof(*tcph) + noff) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto drop;
@ -186,9 +188,9 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
{
struct udphdr *udph;
if (!pskb_may_pull(skb, ihl + sizeof(*udph)) ||
if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) ||
(skb_cloned(skb) &&
!skb_clone_writable(skb, ihl + sizeof(*udph)) &&
!skb_clone_writable(skb, ihl + sizeof(*udph) + noff) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto drop;
@ -205,7 +207,7 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
{
struct icmphdr *icmph;
if (!pskb_may_pull(skb, ihl + sizeof(*icmph)))
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
@ -215,7 +217,8 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
(icmph->type != ICMP_PARAMETERPROB))
break;
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph)))
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph) +
noff))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
@ -229,8 +232,8 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
break;
if (skb_cloned(skb) &&
!skb_clone_writable(skb,
ihl + sizeof(*icmph) + sizeof(*iph)) &&
!skb_clone_writable(skb, ihl + sizeof(*icmph) +
sizeof(*iph) + noff) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto drop;