netfilter: conntrack: remove ctnetlink callbacks from l3 protocol trackers

handle everything from ctnetlink directly.

After all these years we still only support ipv4 and ipv6, so it
seems reasonable to remove l3 protocol tracker support and instead
handle ipv4/ipv6 from a common, always builtin inet tracker.

Step 1: Get rid of all the l3proto->func() calls.

Start with ctnetlink, then move on to packet-path ones.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack_core.h

@@ -68,10 +68,8 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb)
 	return ret;
 }
 
-void
-print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
-            const struct nf_conntrack_l3proto *l3proto,
-            const struct nf_conntrack_l4proto *proto);
+void print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
+		 const struct nf_conntrack_l4proto *proto);
 
 #define CONNTRACK_LOCKS 1024
 

include/net/netfilter/nf_conntrack_l3proto.h

@@ -46,14 +46,6 @@ struct nf_conntrack_l3proto {
 	int (*get_l4proto)(const struct sk_buff *skb, unsigned int nhoff,
 			   unsigned int *dataoff, u_int8_t *protonum);
 
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	int (*tuple_to_nlattr)(struct sk_buff *skb,
-			       const struct nf_conntrack_tuple *t);
-	int (*nlattr_to_tuple)(struct nlattr *tb[],
-			       struct nf_conntrack_tuple *t);
-	const struct nla_policy *nla_policy;
-#endif
-
 	/* Called when netns wants to use connection tracking */
 	int (*net_ns_get)(struct net *);
 	void (*net_ns_put)(struct net *);

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

@@ -274,41 +274,6 @@ getorigdst(struct sock *sk, int optval, void __user *user, int *len)
 	return -ENOENT;
 }
 
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-
-#include <linux/netfilter/nfnetlink.h>
-#include <linux/netfilter/nfnetlink_conntrack.h>
-
-static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
-				const struct nf_conntrack_tuple *tuple)
-{
-	if (nla_put_in_addr(skb, CTA_IP_V4_SRC, tuple->src.u3.ip) ||
-	    nla_put_in_addr(skb, CTA_IP_V4_DST, tuple->dst.u3.ip))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -1;
-}
-
-static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
-	[CTA_IP_V4_SRC]	= { .type = NLA_U32 },
-	[CTA_IP_V4_DST]	= { .type = NLA_U32 },
-};
-
-static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
-				struct nf_conntrack_tuple *t)
-{
-	if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
-		return -EINVAL;
-
-	t->src.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_SRC]);
-	t->dst.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_DST]);
-
-	return 0;
-}
-#endif
-
 static struct nf_sockopt_ops so_getorigdst = {
 	.pf		= PF_INET,
 	.get_optmin	= SO_ORIGINAL_DST,
@@ -360,13 +325,6 @@ const struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 = {
 	.pkt_to_tuple	 = ipv4_pkt_to_tuple,
 	.invert_tuple	 = ipv4_invert_tuple,
 	.get_l4proto	 = ipv4_get_l4proto,
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	.tuple_to_nlattr = ipv4_tuple_to_nlattr,
-	.nlattr_to_tuple = ipv4_nlattr_to_tuple,
-	.nla_policy	 = ipv4_nla_policy,
-	.nla_size	 = NLA_ALIGN(NLA_HDRLEN + sizeof(u32)) + /* CTA_IP_V4_SRC */
-			   NLA_ALIGN(NLA_HDRLEN + sizeof(u32)),  /* CTA_IP_V4_DST */
-#endif
 	.net_ns_get	 = ipv4_hooks_register,
 	.net_ns_put	 = ipv4_hooks_unregister,
 	.me		 = THIS_MODULE,
@@ -419,11 +377,6 @@ static int __init nf_conntrack_l3proto_ipv4_init(void)
 
 	need_conntrack();
 
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	if (WARN_ON(nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1) !=
-	    nf_conntrack_l3proto_ipv4.nla_size))
-		return -EINVAL;
-#endif
 	ret = nf_register_sockopt(&so_getorigdst);
 	if (ret < 0) {
 		pr_err("Unable to register netfilter socket option\n");

net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c

@@ -269,41 +269,6 @@ ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
 	return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
 }
 
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-
-#include <linux/netfilter/nfnetlink.h>
-#include <linux/netfilter/nfnetlink_conntrack.h>
-
-static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
-				const struct nf_conntrack_tuple *tuple)
-{
-	if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) ||
-	    nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -1;
-}
-
-static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
-	[CTA_IP_V6_SRC]	= { .len = sizeof(u_int32_t)*4 },
-	[CTA_IP_V6_DST]	= { .len = sizeof(u_int32_t)*4 },
-};
-
-static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
-				struct nf_conntrack_tuple *t)
-{
-	if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
-		return -EINVAL;
-
-	t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
-	t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
-
-	return 0;
-}
-#endif
-
 static int ipv6_hooks_register(struct net *net)
 {
 	struct conntrack6_net *cnet = net_generic(net, conntrack6_net_id);
@@ -345,13 +310,6 @@ const struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = {
 	.pkt_to_tuple		= ipv6_pkt_to_tuple,
 	.invert_tuple		= ipv6_invert_tuple,
 	.get_l4proto		= ipv6_get_l4proto,
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	.tuple_to_nlattr	= ipv6_tuple_to_nlattr,
-	.nlattr_to_tuple	= ipv6_nlattr_to_tuple,
-	.nla_policy		= ipv6_nla_policy,
-	.nla_size		= NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])) +
-				  NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])),
-#endif
 	.net_ns_get		= ipv6_hooks_register,
 	.net_ns_put		= ipv6_hooks_unregister,
 	.me			= THIS_MODULE,
@@ -409,12 +367,6 @@ static int __init nf_conntrack_l3proto_ipv6_init(void)
 
 	need_conntrack();
 
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	if (WARN_ON(nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1) !=
-	    nf_conntrack_l3proto_ipv6.nla_size))
-		return -EINVAL;
-#endif
-
 	ret = nf_register_sockopt(&so_getorigdst6);
 	if (ret < 0) {
 		pr_err("Unable to register netfilter socket option\n");

net/ipv6/netfilter/nf_defrag_ipv6_hooks.c

@@ -23,7 +23,6 @@
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
 #endif

net/netfilter/nf_conntrack_expect.c

@@ -610,7 +610,6 @@ static int exp_seq_show(struct seq_file *s, void *v)
 		   expect->tuple.src.l3num,
 		   expect->tuple.dst.protonum);
 	print_tuple(s, &expect->tuple,
-		    __nf_ct_l3proto_find(expect->tuple.src.l3num),
 		    __nf_ct_l4proto_find(expect->tuple.src.l3num,
 				       expect->tuple.dst.protonum));
 

net/netfilter/nf_conntrack_helper.c

@@ -24,7 +24,6 @@
 #include <linux/rtnetlink.h>
 
 #include <net/netfilter/nf_conntrack.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_core.h>

net/netfilter/nf_conntrack_netlink.c

@@ -38,7 +38,6 @@
 #include <net/netfilter/nf_conntrack_expect.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_seqadj.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
 #include <net/netfilter/nf_conntrack_acct.h>
@@ -81,9 +80,26 @@ static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
 	return -1;
 }
 
+static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
+				const struct nf_conntrack_tuple *tuple)
+{
+	if (nla_put_in_addr(skb, CTA_IP_V4_SRC, tuple->src.u3.ip) ||
+	    nla_put_in_addr(skb, CTA_IP_V4_DST, tuple->dst.u3.ip))
+		return -EMSGSIZE;
+	return 0;
+}
+
+static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
+				const struct nf_conntrack_tuple *tuple)
+{
+	if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) ||
+	    nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6))
+		return -EMSGSIZE;
+	return 0;
+}
+
 static int ctnetlink_dump_tuples_ip(struct sk_buff *skb,
-				    const struct nf_conntrack_tuple *tuple,
-				    const struct nf_conntrack_l3proto *l3proto)
+				    const struct nf_conntrack_tuple *tuple)
 {
 	int ret = 0;
 	struct nlattr *nest_parms;
@@ -92,8 +108,14 @@ static int ctnetlink_dump_tuples_ip(struct sk_buff *skb,
 	if (!nest_parms)
 		goto nla_put_failure;
 
-	if (likely(l3proto->tuple_to_nlattr))
-		ret = l3proto->tuple_to_nlattr(skb, tuple);
+	switch (tuple->src.l3num) {
+	case NFPROTO_IPV4:
+		ret = ipv4_tuple_to_nlattr(skb, tuple);
+		break;
+	case NFPROTO_IPV6:
+		ret = ipv6_tuple_to_nlattr(skb, tuple);
+		break;
+	}
 
 	nla_nest_end(skb, nest_parms);
 
@@ -106,13 +128,11 @@ static int ctnetlink_dump_tuples_ip(struct sk_buff *skb,
 static int ctnetlink_dump_tuples(struct sk_buff *skb,
 				 const struct nf_conntrack_tuple *tuple)
 {
-	const struct nf_conntrack_l3proto *l3proto;
 	const struct nf_conntrack_l4proto *l4proto;
 	int ret;
 
 	rcu_read_lock();
-	l3proto = __nf_ct_l3proto_find(tuple->src.l3num);
-	ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);
+	ret = ctnetlink_dump_tuples_ip(skb, tuple);
 
 	if (ret >= 0) {
 		l4proto = __nf_ct_l4proto_find(tuple->src.l3num,
@@ -556,15 +576,20 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 	return -1;
 }
 
+static const struct nla_policy cta_ip_nla_policy[CTA_IP_MAX + 1] = {
+	[CTA_IP_V4_SRC]	= { .type = NLA_U32 },
+	[CTA_IP_V4_DST]	= { .type = NLA_U32 },
+	[CTA_IP_V6_SRC]	= { .len = sizeof(__be32) * 4 },
+	[CTA_IP_V6_DST]	= { .len = sizeof(__be32) * 4 },
+};
+
 #if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS)
 static size_t ctnetlink_proto_size(const struct nf_conn *ct)
 {
-	const struct nf_conntrack_l3proto *l3proto;
 	const struct nf_conntrack_l4proto *l4proto;
 	size_t len, len4 = 0;
 
-	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
-	len = l3proto->nla_size;
+	len = nla_policy_len(cta_ip_nla_policy, CTA_IP_MAX + 1);
 	len *= 3u; /* ORIG, REPLY, MASTER */
 
 	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
@@ -936,29 +961,54 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
+static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
+				struct nf_conntrack_tuple *t)
+{
+	if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
+		return -EINVAL;
+
+	t->src.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_SRC]);
+	t->dst.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_DST]);
+
+	return 0;
+}
+
+static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
+				struct nf_conntrack_tuple *t)
+{
+	if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
+		return -EINVAL;
+
+	t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
+	t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
+
+	return 0;
+}
+
 static int ctnetlink_parse_tuple_ip(struct nlattr *attr,
 				    struct nf_conntrack_tuple *tuple)
 {
 	struct nlattr *tb[CTA_IP_MAX+1];
-	struct nf_conntrack_l3proto *l3proto;
 	int ret = 0;
 
 	ret = nla_parse_nested(tb, CTA_IP_MAX, attr, NULL, NULL);
 	if (ret < 0)
 		return ret;
 
-	rcu_read_lock();
-	l3proto = __nf_ct_l3proto_find(tuple->src.l3num);
+	ret = nla_validate_nested(attr, CTA_IP_MAX,
+				  cta_ip_nla_policy, NULL);
+	if (ret)
+		return ret;
 
-	if (likely(l3proto->nlattr_to_tuple)) {
-		ret = nla_validate_nested(attr, CTA_IP_MAX,
-					  l3proto->nla_policy, NULL);
-		if (ret == 0)
-			ret = l3proto->nlattr_to_tuple(tb, tuple);
+	switch (tuple->src.l3num) {
+	case NFPROTO_IPV4:
+		ret = ipv4_nlattr_to_tuple(tb, tuple);
+		break;
+	case NFPROTO_IPV6:
+		ret = ipv6_nlattr_to_tuple(tb, tuple);
+		break;
 	}
 
-	rcu_read_unlock();
-
 	return ret;
 }
 
@@ -2581,7 +2631,6 @@ static int ctnetlink_exp_dump_mask(struct sk_buff *skb,
 				   const struct nf_conntrack_tuple *tuple,
 				   const struct nf_conntrack_tuple_mask *mask)
 {
-	const struct nf_conntrack_l3proto *l3proto;
 	const struct nf_conntrack_l4proto *l4proto;
 	struct nf_conntrack_tuple m;
 	struct nlattr *nest_parms;
@@ -2597,8 +2646,7 @@ static int ctnetlink_exp_dump_mask(struct sk_buff *skb,
 		goto nla_put_failure;
 
 	rcu_read_lock();
-	l3proto = __nf_ct_l3proto_find(tuple->src.l3num);
-	ret = ctnetlink_dump_tuples_ip(skb, &m, l3proto);
+	ret = ctnetlink_dump_tuples_ip(skb, &m);
 	if (ret >= 0) {
 		l4proto = __nf_ct_l4proto_find(tuple->src.l3num,
 					       tuple->dst.protonum);

net/netfilter/nf_conntrack_proto.c

@@ -294,10 +294,7 @@ int nf_ct_l3proto_register(const struct nf_conntrack_l3proto *proto)
 
 	if (proto->l3proto >= NFPROTO_NUMPROTO)
 		return -EBUSY;
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	if (proto->tuple_to_nlattr && proto->nla_size == 0)
-		return -EINVAL;
-#endif
+
 	mutex_lock(&nf_ct_proto_mutex);
 	old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
 					lockdep_is_held(&nf_ct_proto_mutex));

net/netfilter/nf_conntrack_standalone.c

@@ -24,7 +24,6 @@
 
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_core.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_expect.h>
 #include <net/netfilter/nf_conntrack_helper.h>
@@ -38,10 +37,9 @@ MODULE_LICENSE("GPL");
 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 void
 print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
-            const struct nf_conntrack_l3proto *l3proto,
             const struct nf_conntrack_l4proto *l4proto)
 {
-	switch (l3proto->l3proto) {
+	switch (tuple->src.l3num) {
 	case NFPROTO_IPV4:
 		seq_printf(s, "src=%pI4 dst=%pI4 ",
 			   &tuple->src.u3.ip, &tuple->dst.u3.ip);
@@ -282,7 +280,6 @@ static int ct_seq_show(struct seq_file *s, void *v)
 {
 	struct nf_conntrack_tuple_hash *hash = v;
 	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
-	const struct nf_conntrack_l3proto *l3proto;
 	const struct nf_conntrack_l4proto *l4proto;
 	struct net *net = seq_file_net(s);
 	int ret = 0;
@@ -303,14 +300,12 @@ static int ct_seq_show(struct seq_file *s, void *v)
 	if (!net_eq(nf_ct_net(ct), net))
 		goto release;
 
-	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
-	WARN_ON(!l3proto);
 	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 	WARN_ON(!l4proto);
 
 	ret = -ENOSPC;
 	seq_printf(s, "%-8s %u %-8s %u ",
-		   l3proto_name(l3proto->l3proto), nf_ct_l3num(ct),
+		   l3proto_name(nf_ct_l3num(ct)), nf_ct_l3num(ct),
 		   l4proto_name(l4proto->l4proto), nf_ct_protonum(ct));
 
 	if (!test_bit(IPS_OFFLOAD_BIT, &ct->status))
@@ -320,7 +315,7 @@ static int ct_seq_show(struct seq_file *s, void *v)
 		l4proto->print_conntrack(s, ct);
 
 	print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-		    l3proto, l4proto);
+		    l4proto);
 
 	ct_show_zone(s, ct, NF_CT_ZONE_DIR_ORIG);
 
@@ -333,8 +328,7 @@ static int ct_seq_show(struct seq_file *s, void *v)
 	if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
 		seq_puts(s, "[UNREPLIED] ");
 
-	print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
-		    l3proto, l4proto);
+	print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple, l4proto);
 
 	ct_show_zone(s, ct, NF_CT_ZONE_DIR_REPL);
 

net/netfilter/nfnetlink_cttimeout.c

@@ -26,7 +26,6 @@
 #include <net/sock.h>
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_core.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
 #include <net/netfilter/nf_conntrack_timeout.h>