netfilter: add and use nf_ct_netns_get/put

currently aliased to try_module_get/_put.
Will be changed in next patch when we add functions to make use of ->net
argument to store usercount per l3proto tracker.

This is needed to avoid registering the conntrack hooks in all netns and
later only enable connection tracking in those that need conntrack.

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

include/net/netfilter/nf_conntrack.h

···
 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 void nf_ct_l3proto_module_put(unsigned short l3proto);
 
+/* load module; enable/disable conntrack in this namespace */
+int nf_ct_netns_get(struct net *net, u8 nfproto);
+void nf_ct_netns_put(struct net *net, u8 nfproto);
+
 /*
  * Allocate a hashtable of hlist_head (if nulls == 0),
  * or hlist_nulls_head (if nulls == 1)

net/ipv4/netfilter/ipt_CLUSTERIP.c

···
 	}
 	cipinfo->config = config;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 	clusterip_config_put(cipinfo->config);
 
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_get(par->net, par->family);
 }
 
 #ifdef CONFIG_COMPAT

net/ipv4/netfilter/ipt_SYNPROXY.c

···
 	    e->ip.invflags & XT_INV_PROTO)
 		return -EINVAL;
 
-	return nf_ct_l3proto_try_module_get(par->family);
+	return nf_ct_netns_get(par->net, par->family);
 }
 
 static void synproxy_tg4_destroy(const struct xt_tgdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_target synproxy_tg4_reg __read_mostly = {

net/ipv6/netfilter/ip6t_SYNPROXY.c

···
 	    e->ipv6.invflags & XT_INV_PROTO)
 		return -EINVAL;
 
-	return nf_ct_l3proto_try_module_get(par->family);
+	return nf_ct_netns_get(par->net, par->family);
 }
 
 static void synproxy_tg6_destroy(const struct xt_tgdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_target synproxy_tg6_reg __read_mostly = {

net/netfilter/nf_conntrack_proto.c

···
 }
 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
 
+int nf_ct_netns_get(struct net *net, u8 nfproto)
+{
+	return nf_ct_l3proto_try_module_get(nfproto);
+}
+EXPORT_SYMBOL_GPL(nf_ct_netns_get);
+
+void nf_ct_netns_put(struct net *net, u8 nfproto)
+{
+	nf_ct_l3proto_module_put(nfproto);
+}
+EXPORT_SYMBOL_GPL(nf_ct_netns_put);
+
 struct nf_conntrack_l4proto *
 nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
 {

net/netfilter/nft_ct.c

···
 	[NFTA_CT_SREG]		= { .type = NLA_U32 },
 };
 
-static int nft_ct_l3proto_try_module_get(uint8_t family)
+static int nft_ct_netns_get(struct net *net, uint8_t family)
 {
 	int err;
 
 	if (family == NFPROTO_INET) {
-		err = nf_ct_l3proto_try_module_get(NFPROTO_IPV4);
+		err = nf_ct_netns_get(net, NFPROTO_IPV4);
 		if (err < 0)
 			goto err1;
-		err = nf_ct_l3proto_try_module_get(NFPROTO_IPV6);
+		err = nf_ct_netns_get(net, NFPROTO_IPV6);
 		if (err < 0)
 			goto err2;
 	} else {
-		err = nf_ct_l3proto_try_module_get(family);
+		err = nf_ct_netns_get(net, family);
 		if (err < 0)
 			goto err1;
 	}
 	return 0;
 
 err2:
-	nf_ct_l3proto_module_put(NFPROTO_IPV4);
+	nf_ct_netns_put(net, NFPROTO_IPV4);
 err1:
 	return err;
 }
 
-static void nft_ct_l3proto_module_put(uint8_t family)
+static void nft_ct_netns_put(struct net *net, uint8_t family)
 {
 	if (family == NFPROTO_INET) {
-		nf_ct_l3proto_module_put(NFPROTO_IPV4);
-		nf_ct_l3proto_module_put(NFPROTO_IPV6);
+		nf_ct_netns_put(net, NFPROTO_IPV4);
+		nf_ct_netns_put(net, NFPROTO_IPV6);
 	} else
-		nf_ct_l3proto_module_put(family);
+		nf_ct_netns_put(net, family);
 }
 
 static int nft_ct_get_init(const struct nft_ctx *ctx,
···
 	if (err < 0)
 		return err;
 
-	err = nft_ct_l3proto_try_module_get(ctx->afi->family);
+	err = nft_ct_netns_get(ctx->net, ctx->afi->family);
 	if (err < 0)
 		return err;
 
···
 	if (err < 0)
 		goto err1;
 
-	err = nft_ct_l3proto_try_module_get(ctx->afi->family);
+	err = nft_ct_netns_get(ctx->net, ctx->afi->family);
 	if (err < 0)
 		goto err1;
 
···
 static void nft_ct_get_destroy(const struct nft_ctx *ctx,
 			       const struct nft_expr *expr)
 {
-	nft_ct_l3proto_module_put(ctx->afi->family);
+	nf_ct_netns_put(ctx->net, ctx->afi->family);
 }
 
 static void nft_ct_set_destroy(const struct nft_ctx *ctx,
···
 		break;
 	}
 
-	nft_ct_l3proto_module_put(ctx->afi->family);
+	nft_ct_netns_put(ctx->net, ctx->afi->family);
 }
 
 static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr)

net/netfilter/xt_CONNSECMARK.c

···
 		return -EINVAL;
 	}
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void connsecmark_tg_destroy(const struct xt_tgdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_target connsecmark_tg_reg __read_mostly = {

net/netfilter/xt_CT.c

···
 		goto err1;
 #endif
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		goto err1;
 
···
 err3:
 	nf_ct_tmpl_free(ct);
 err2:
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 err1:
 	return ret;
 }
···
 		if (help)
 			module_put(help->helper->me);
 
-		nf_ct_l3proto_module_put(par->family);
+		nf_ct_netns_put(par->net, par->family);
 
 		xt_ct_destroy_timeout(ct);
 		nf_ct_put(info->ct);

net/netfilter/xt_connbytes.c

···
 	    sinfo->direction != XT_CONNBYTES_DIR_BOTH)
 		return -EINVAL;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void connbytes_mt_destroy(const struct xt_mtdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_match connbytes_mt_reg __read_mostly = {

net/netfilter/xt_connlabel.c

···
 		return -EINVAL;
 	}
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0) {
 		pr_info("cannot load conntrack support for proto=%u\n",
 							par->family);
···
 
 	ret = nf_connlabels_get(par->net, info->bit);
 	if (ret < 0)
-		nf_ct_l3proto_module_put(par->family);
+		nf_ct_netns_put(par->net, par->family);
 	return ret;
 }
 
 static void connlabel_mt_destroy(const struct xt_mtdtor_param *par)
 {
 	nf_connlabels_put(par->net);
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_match connlabels_mt_reg __read_mostly = {

net/netfilter/xt_connlimit.c

···
 
 	net_get_random_once(&connlimit_rnd, sizeof(connlimit_rnd));
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0) {
 		pr_info("cannot load conntrack support for "
 			"address family %u\n", par->family);
···
 	/* init private data */
 	info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
 	if (info->data == NULL) {
-		nf_ct_l3proto_module_put(par->family);
+		nf_ct_netns_put(par->net, par->family);
 		return -ENOMEM;
 	}
 
···
 	const struct xt_connlimit_info *info = par->matchinfo;
 	unsigned int i;
 
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 
 	for (i = 0; i < ARRAY_SIZE(info->data->climit_root4); ++i)
 		destroy_tree(&info->data->climit_root4[i]);

net/netfilter/xt_connmark.c

···
 {
 	int ret;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static bool
···
 {
 	int ret;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_target connmark_tg_reg __read_mostly = {

net/netfilter/xt_conntrack.c

···
 {
 	int ret;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_match conntrack_mt_reg[] __read_mostly = {

net/netfilter/xt_helper.c

···
 	struct xt_helper_info *info = par->matchinfo;
 	int ret;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0) {
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void helper_mt_destroy(const struct xt_mtdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_match helper_mt_reg __read_mostly = {

net/netfilter/xt_state.c

···
 {
 	int ret;
 
-	ret = nf_ct_l3proto_try_module_get(par->family);
+	ret = nf_ct_netns_get(par->net, par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
···
 
 static void state_mt_destroy(const struct xt_mtdtor_param *par)
 {
-	nf_ct_l3proto_module_put(par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 static struct xt_match state_mt_reg __read_mostly = {