netfilter: Add helper array register/unregister functions

Add nf_ct_helper_init(), nf_conntrack_helpers_register() and
nf_conntrack_helpers_unregister() functions to avoid repetitive
opencoded initialization in helpers.

This patch keeps an id parameter for nf_ct_helper_init() not to break
helper matching by name that has been inconsistently exposed to
userspace through ports, eg. ftp-2121, and through an incremental id,
eg. tftp-1.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 15 insertions, 33 deletions

diff --git a/net/netfilter/nf_conntrack_tftp.c b/net/netfilter/nf_conntrack_tftp.c
index 2e65b5430fba..b1227dc6f75e 100644
--- a/net/netfilter/nf_conntrack_tftp.c
+++ b/net/netfilter/nf_conntrack_tftp.c
@@ -97,7 +97,7 @@ static int tftp_help(struct sk_buff *skb,
 	return ret;
 }
 
-static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
+static struct nf_conntrack_helper tftp[MAX_PORTS * 2] __read_mostly;
 
 static const struct nf_conntrack_expect_policy tftp_exp_policy = {
 	.max_expected	= 1,
@@ -106,47 +106,29 @@ static const struct nf_conntrack_expect_policy tftp_exp_policy = {
 
 static void nf_conntrack_tftp_fini(void)
 {
-	int i, j;
-
-	for (i = 0; i < ports_c; i++) {
-		for (j = 0; j < 2; j++)
-			nf_conntrack_helper_unregister(&tftp[i][j]);
-	}
+	nf_conntrack_helpers_unregister(tftp, ports_c * 2);
 }
 
 static int __init nf_conntrack_tftp_init(void)
 {
-	int i, j, ret;
+	int i, ret;
 
 	if (ports_c == 0)
 		ports[ports_c++] = TFTP_PORT;
 
 	for (i = 0; i < ports_c; i++) {
-		memset(&tftp[i], 0, sizeof(tftp[i]));
-
-		tftp[i][0].tuple.src.l3num = AF_INET;
-		tftp[i][1].tuple.src.l3num = AF_INET6;
-		for (j = 0; j < 2; j++) {
-			tftp[i][j].tuple.dst.protonum = IPPROTO_UDP;
-			tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
-			tftp[i][j].expect_policy = &tftp_exp_policy;
-			tftp[i][j].me = THIS_MODULE;
-			tftp[i][j].help = tftp_help;
-
-			if (ports[i] == TFTP_PORT)
-				sprintf(tftp[i][j].name, "tftp");
-			else
-				sprintf(tftp[i][j].name, "tftp-%u", i);
-
-			ret = nf_conntrack_helper_register(&tftp[i][j]);
-			if (ret) {
-				pr_err("failed to register helper for pf: %u port: %u\n",
-				       tftp[i][j].tuple.src.l3num, ports[i]);
-				ports_c = i;
-				nf_conntrack_tftp_fini();
-				return ret;
-			}
-		}
+		nf_ct_helper_init(&tftp[2 * i], AF_INET, IPPROTO_UDP, "tftp",
+				  TFTP_PORT, ports[i], i, &tftp_exp_policy,
+				  0, 0, tftp_help, NULL, THIS_MODULE);
+		nf_ct_helper_init(&tftp[2 * i + 1], AF_INET6, IPPROTO_UDP, "tftp",
+				  TFTP_PORT, ports[i], i, &tftp_exp_policy,
+				  0, 0, tftp_help, NULL, THIS_MODULE);
+	}
+
+	ret = nf_conntrack_helpers_register(tftp, ports_c * 2);
+	if (ret < 0) {
+		pr_err("failed to register helpers\n");
+		return ret;
 	}
 	return 0;
 }