[NETFILTER]: nf_nat: add reference to conntrack from entry of bysource list

I will split 'struct nf_nat_info' out from conntrack. So I cannot use
'offsetof' to get the pointer to conntrack from it.

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, 3 insertions, 1 deletions

diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index ea02f00d2dac..ac7e8abbbdeb 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -97,6 +97,7 @@ static void nf_nat_cleanup_conntrack(struct nf_conn *conn)
         nat = nfct_nat(conn);
         write_lock_bh(&nf_nat_lock);
         list_del(&nat->info.bysource);
+        nat->info.ct = NULL;
         write_unlock_bh(&nf_nat_lock);
 }
 
@@ -169,7 +170,7 @@ find_appropriate_src(const struct nf_conntrack_tuple *tuple,
 
         read_lock_bh(&nf_nat_lock);
         list_for_each_entry(nat, &bysource[h], info.bysource) {
-                ct = (struct nf_conn *)((char *)nat - offsetof(struct nf_conn, data));
+                ct = nat->info.ct;
                 if (same_src(ct, tuple)) {
                         /* Copy source part from reply tuple. */
                         nf_ct_invert_tuplepr(result,
@@ -337,6 +338,7 @@ nf_nat_setup_info(struct nf_conn *ct,
 
                 srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
                 write_lock_bh(&nf_nat_lock);
+                info->ct = ct;
                 list_add(&info->bysource, &bysource[srchash]);
                 write_unlock_bh(&nf_nat_lock);
         }