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, 18 insertions, 40 deletions

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 19efeba02abb..43147005bea3 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -572,7 +572,7 @@ static int nf_ct_ftp_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
 	return 0;
 }
 
-static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly;
+static struct nf_conntrack_helper ftp[MAX_PORTS * 2] __read_mostly;
 
 static const struct nf_conntrack_expect_policy ftp_exp_policy = {
 	.max_expected	= 1,
@@ -582,24 +582,13 @@ static const struct nf_conntrack_expect_policy ftp_exp_policy = {
 /* don't make this __exit, since it's called from __init ! */
 static void nf_conntrack_ftp_fini(void)
 {
-	int i, j;
-	for (i = 0; i < ports_c; i++) {
-		for (j = 0; j < 2; j++) {
-			if (ftp[i][j].me == NULL)
-				continue;
-
-			pr_debug("unregistering helper for pf: %d port: %d\n",
-				 ftp[i][j].tuple.src.l3num, ports[i]);
-			nf_conntrack_helper_unregister(&ftp[i][j]);
-		}
-	}
-
+	nf_conntrack_helpers_unregister(ftp, ports_c * 2);
 	kfree(ftp_buffer);
 }
 
 static int __init nf_conntrack_ftp_init(void)
 {
-	int i, j = -1, ret = 0;
+	int i, ret = 0;
 
 	ftp_buffer = kmalloc(65536, GFP_KERNEL);
 	if (!ftp_buffer)
@@ -611,32 +600,21 @@ static int __init nf_conntrack_ftp_init(void)
 	/* FIXME should be configurable whether IPv4 and IPv6 FTP connections
 		 are tracked or not - YK */
 	for (i = 0; i < ports_c; i++) {
-		ftp[i][0].tuple.src.l3num = PF_INET;
-		ftp[i][1].tuple.src.l3num = PF_INET6;
-		for (j = 0; j < 2; j++) {
-			ftp[i][j].data_len = sizeof(struct nf_ct_ftp_master);
-			ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]);
-			ftp[i][j].tuple.dst.protonum = IPPROTO_TCP;
-			ftp[i][j].expect_policy = &ftp_exp_policy;
-			ftp[i][j].me = THIS_MODULE;
-			ftp[i][j].help = help;
-			ftp[i][j].from_nlattr = nf_ct_ftp_from_nlattr;
-			if (ports[i] == FTP_PORT)
-				sprintf(ftp[i][j].name, "ftp");
-			else
-				sprintf(ftp[i][j].name, "ftp-%d", ports[i]);
-
-			pr_debug("registering helper for pf: %d port: %d\n",
-				 ftp[i][j].tuple.src.l3num, ports[i]);
-			ret = nf_conntrack_helper_register(&ftp[i][j]);
-			if (ret) {
-				pr_err("failed to register helper for pf: %d port: %d\n",
-				       ftp[i][j].tuple.src.l3num, ports[i]);
-				ports_c = i;
-				nf_conntrack_ftp_fini();
-				return ret;
-			}
-		}
+		nf_ct_helper_init(&ftp[2 * i], AF_INET, IPPROTO_TCP, "ftp",
+				  FTP_PORT, ports[i], ports[i], &ftp_exp_policy,
+				  0, sizeof(struct nf_ct_ftp_master), help,
+				  nf_ct_ftp_from_nlattr, THIS_MODULE);
+		nf_ct_helper_init(&ftp[2 * i + 1], AF_INET6, IPPROTO_TCP, "ftp",
+				  FTP_PORT, ports[i], ports[i], &ftp_exp_policy,
+				  0, sizeof(struct nf_ct_ftp_master), help,
+				  nf_ct_ftp_from_nlattr, THIS_MODULE);
+	}
+
+	ret = nf_conntrack_helpers_register(ftp, ports_c * 2);
+	if (ret < 0) {
+		pr_err("failed to register helpers\n");
+		kfree(ftp_buffer);
+		return ret;
 	}
 
 	return 0;