[NETFILTER]: nf_conntrack: introduce expectation classes and policies

Introduce expectation classes and policies. An expectation class
is used to distinguish different types of expectations by the
same helper (for example audio/video/t.120). The expectation
policy is used to hold the maximum number of expectations and
the initial timeout for each class.

The individual classes are isolated from each other, which means
that for example an audio expectation will only evict other audio
expectations.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 6770baf..7eff876 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -483,7 +483,7 @@ static int help(struct sk_buff *skb,
 		daddr = &cmd.u3;
 	}
 
-	nf_ct_expect_init(exp, cmd.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, cmd.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, daddr,
 			  IPPROTO_TCP, NULL, &cmd.u.tcp.port);
 
@@ -517,6 +517,11 @@ out_update_nl:
 static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly;
 static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")] __read_mostly;
 
+static const struct nf_conntrack_expect_policy ftp_exp_policy = {
+	.max_expected	= 1,
+	.timeout	= 5 * 60,
+};
+
 /* don't make this __exit, since it's called from __init ! */
 static void nf_conntrack_ftp_fini(void)
 {
@@ -556,8 +561,7 @@ static int __init nf_conntrack_ftp_init(void)
 		for (j = 0; j < 2; j++) {
 			ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]);
 			ftp[i][j].tuple.dst.protonum = IPPROTO_TCP;
-			ftp[i][j].max_expected = 1;
-			ftp[i][j].timeout = 5 * 60;	/* 5 Minutes */
+			ftp[i][j].expect_policy = &ftp_exp_policy;
 			ftp[i][j].me = THIS_MODULE;
 			ftp[i][j].help = help;
 			tmpname = &ftp_names[i][j][0];