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, 28 insertions, 47 deletions

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index f72ba55..8d9db9d 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1589,7 +1589,7 @@ static int sip_help_udp(struct sk_buff *skb, unsigned int protoff,
 	return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen);
 }
 
-static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly;
+static struct nf_conntrack_helper sip[MAX_PORTS * 4] __read_mostly;
 
 static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = {
 	[SIP_EXPECT_SIGNALLING] = {
@@ -1616,20 +1616,12 @@ static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1
 
 static void nf_conntrack_sip_fini(void)
 {
-	int i, j;
-
-	for (i = 0; i < ports_c; i++) {
-		for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
-			if (sip[i][j].me == NULL)
-				continue;
-			nf_conntrack_helper_unregister(&sip[i][j]);
-		}
-	}
+	nf_conntrack_helpers_unregister(sip, ports_c * 4);
 }
 
 static int __init nf_conntrack_sip_init(void)
 {
-	int i, j, ret;
+	int i, ret;
 
 	if (ports_c == 0)
 		ports[ports_c++] = SIP_PORT;
@@ -1637,43 +1629,32 @@ static int __init nf_conntrack_sip_init(void)
 	for (i = 0; i < ports_c; i++) {
 		memset(&sip[i], 0, sizeof(sip[i]));
 
-		sip[i][0].tuple.src.l3num = AF_INET;
-		sip[i][0].tuple.dst.protonum = IPPROTO_UDP;
-		sip[i][0].help = sip_help_udp;
-		sip[i][1].tuple.src.l3num = AF_INET;
-		sip[i][1].tuple.dst.protonum = IPPROTO_TCP;
-		sip[i][1].help = sip_help_tcp;
-
-		sip[i][2].tuple.src.l3num = AF_INET6;
-		sip[i][2].tuple.dst.protonum = IPPROTO_UDP;
-		sip[i][2].help = sip_help_udp;
-		sip[i][3].tuple.src.l3num = AF_INET6;
-		sip[i][3].tuple.dst.protonum = IPPROTO_TCP;
-		sip[i][3].help = sip_help_tcp;
-
-		for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
-			sip[i][j].data_len = sizeof(struct nf_ct_sip_master);
-			sip[i][j].tuple.src.u.udp.port = htons(ports[i]);
-			sip[i][j].expect_policy = sip_exp_policy;
-			sip[i][j].expect_class_max = SIP_EXPECT_MAX;
-			sip[i][j].me = THIS_MODULE;
-
-			if (ports[i] == SIP_PORT)
-				sprintf(sip[i][j].name, "sip");
-			else
-				sprintf(sip[i][j].name, "sip-%u", i);
-
-			pr_debug("port #%u: %u\n", i, ports[i]);
+		nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip",
+				  SIP_PORT, ports[i], i, sip_exp_policy,
+				  SIP_EXPECT_MAX,
+				  sizeof(struct nf_ct_sip_master), sip_help_udp,
+				  NULL, THIS_MODULE);
+		nf_ct_helper_init(&sip[4 * i + 1], AF_INET, IPPROTO_TCP, "sip",
+				  SIP_PORT, ports[i], i, sip_exp_policy,
+				  SIP_EXPECT_MAX,
+				  sizeof(struct nf_ct_sip_master), sip_help_tcp,
+				  NULL, THIS_MODULE);
+		nf_ct_helper_init(&sip[4 * i + 2], AF_INET6, IPPROTO_UDP, "sip",
+				  SIP_PORT, ports[i], i, sip_exp_policy,
+				  SIP_EXPECT_MAX,
+				  sizeof(struct nf_ct_sip_master), sip_help_udp,
+				  NULL, THIS_MODULE);
+		nf_ct_helper_init(&sip[4 * i + 3], AF_INET6, IPPROTO_TCP, "sip",
+				  SIP_PORT, ports[i], i, sip_exp_policy,
+				  SIP_EXPECT_MAX,
+				  sizeof(struct nf_ct_sip_master), sip_help_tcp,
+				  NULL, THIS_MODULE);
+	}
 
-			ret = nf_conntrack_helper_register(&sip[i][j]);
-			if (ret) {
-				pr_err("failed to register helper for pf: %u port: %u\n",
-				       sip[i][j].tuple.src.l3num, ports[i]);
-				ports_c = i;
-				nf_conntrack_sip_fini();
-				return ret;
-			}
-		}
+	ret = nf_conntrack_helpers_register(sip, ports_c * 4);
+	if (ret < 0) {
+		pr_err("failed to register helpers\n");
+		return ret;
 	}
 	return 0;
 }