[NETFILTER]: nf_conntrack: Introduces nf_ct_get_tuplepr and uses it

nf_ct_get_tuple() requires the offset to transport header and that bothers
callers such as icmp[v6] l4proto modules. This introduces new function
to simplify them.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 25 deletions

diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 0fe8fb0466ef..b8b79992797e 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -136,40 +136,22 @@ icmp_error_message(struct sk_buff *skb,
                  unsigned int hooknum)
 {
         struct nf_conntrack_tuple innertuple, origtuple;
-        struct {
-                struct icmphdr icmp;
-                struct iphdr ip;
-        } _in, *inside;
         struct nf_conntrack_l4proto *innerproto;
         struct nf_conntrack_tuple_hash *h;
-        int dataoff;
 
         NF_CT_ASSERT(skb->nfct == NULL);
 
-        /* Not enough header? */
-        inside = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_in), &_in);
-        if (inside == NULL)
-                return -NF_ACCEPT;
-
-        /* Ignore ICMP's containing fragments (shouldn't happen) */
-        if (inside->ip.frag_off & htons(IP_OFFSET)) {
-                pr_debug("icmp_error_message: fragment of proto %u\n",
-                         inside->ip.protocol);
+        /* Are they talking about one of our connections? */
+        if (!nf_ct_get_tuplepr(skb,
+                               skb_network_offset(skb) + ip_hdrlen(skb)
+                                                       + sizeof(struct icmphdr),
+                               PF_INET, &origtuple)) {
+                pr_debug("icmp_error_message: failed to get tuple\n");
                 return -NF_ACCEPT;
         }
 
         /* rcu_read_lock()ed by nf_hook_slow */
-        innerproto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
-
-        dataoff = ip_hdrlen(skb) + sizeof(inside->icmp);
-        /* Are they talking about one of our connections? */
-        if (!nf_ct_get_tuple(skb, dataoff, dataoff + inside->ip.ihl*4, PF_INET,
-                             inside->ip.protocol, &origtuple,
-                             &nf_conntrack_l3proto_ipv4, innerproto)) {
-                pr_debug("icmp_error_message: ! get_tuple p=%u",
-                         inside->ip.protocol);
-                return -NF_ACCEPT;
-        }
+        innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
 
         /* Ordinarily, we'd expect the inverted tupleproto, but it's
            been preserved inside the ICMP. */