[NETFILTER]: nf_conntrack: automatic helper assignment for expectations
Some helpers (namely H.323) manually assign further helpers to expected
connections. This is not possible with nf_conntrack anymore since we
need to know whether a helper is used at allocation time.
Handle the helper assignment centrally, which allows to perform the
correct allocation and as a nice side effect eliminates the need
for the H.323 helper to fiddle with nf_conntrack_lock.
Mid term the allocation scheme really needs to be redesigned since
we do both the helper and expectation lookup _twice_ for every new
connection.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 2d335f0..5d853e8 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -22,6 +22,9 @@
void (*expectfn)(struct nf_conn *new,
struct nf_conntrack_expect *this);
+ /* Helper to assign to new connection */
+ struct nf_conntrack_helper *helper;
+
/* The conntrack of the master connection */
struct nf_conn *master;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index a401b1e..f952a7f 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -545,10 +545,10 @@
static struct nf_conn *
__nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
- const struct nf_conntrack_l3proto *l3proto)
+ const struct nf_conntrack_l3proto *l3proto,
+ u_int32_t features)
{
struct nf_conn *conntrack = NULL;
- u_int32_t features = 0;
struct nf_conntrack_helper *helper;
if (unlikely(!nf_conntrack_hash_rnd_initted)) {
@@ -574,7 +574,7 @@
}
/* find features needed by this conntrack. */
- features = l3proto->get_features(orig);
+ features |= l3proto->get_features(orig);
/* FIXME: protect helper list per RCU */
read_lock_bh(&nf_conntrack_lock);
@@ -624,7 +624,7 @@
struct nf_conntrack_l3proto *l3proto;
l3proto = __nf_ct_l3proto_find(orig->src.l3num);
- return __nf_conntrack_alloc(orig, repl, l3proto);
+ return __nf_conntrack_alloc(orig, repl, l3proto, 0);
}
void nf_conntrack_free(struct nf_conn *conntrack)
@@ -649,13 +649,20 @@
struct nf_conn *conntrack;
struct nf_conntrack_tuple repl_tuple;
struct nf_conntrack_expect *exp;
+ u_int32_t features = 0;
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
DEBUGP("Can't invert tuple.\n");
return NULL;
}
- conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto);
+ read_lock_bh(&nf_conntrack_lock);
+ exp = __nf_conntrack_expect_find(tuple);
+ if (exp && exp->helper)
+ features = NF_CT_F_HELP;
+ read_unlock_bh(&nf_conntrack_lock);
+
+ conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features);
if (conntrack == NULL || IS_ERR(conntrack)) {
DEBUGP("Can't allocate conntrack.\n");
return (struct nf_conntrack_tuple_hash *)conntrack;
@@ -676,6 +683,8 @@
/* Welcome, Mr. Bond. We've been expecting you... */
__set_bit(IPS_EXPECTED_BIT, &conntrack->status);
conntrack->master = exp->master;
+ if (exp->helper)
+ nfct_help(conntrack)->helper = exp->helper;
#ifdef CONFIG_NF_CONNTRACK_MARK
conntrack->mark = exp->master->mark;
#endif
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index fdac52b..e96c41d 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -516,6 +516,7 @@
}
exp->expectfn = NULL;
+ exp->helper = NULL;
exp->flags = 0;
/* Now, NAT might want to mangle the packet, and register the
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 2628f4b..81542dc 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -129,7 +129,8 @@
/* Get rid of expectations */
list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) {
struct nf_conn_help *help = nfct_help(exp->master);
- if (help->helper == me && del_timer(&exp->timeout)) {
+ if ((help->helper == me || exp->helper == me) &&
+ del_timer(&exp->timeout)) {
nf_ct_unlink_expect(exp);
nf_conntrack_expect_put(exp);
}
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index a693d3b..acaef40 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1447,6 +1447,7 @@
exp->expectfn = NULL;
exp->flags = 0;
exp->master = ct;
+ exp->helper = NULL;
memcpy(&exp->tuple, &tuple, sizeof(struct nf_conntrack_tuple));
memcpy(&exp->mask, &mask, sizeof(struct nf_conntrack_tuple));