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>

6 files changed, 77 insertions, 41 deletions

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 853b23206bb7..3f586ba23d92 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/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));
 
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index a75b11c39312..a55a58c706a9 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/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>
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 20a2e37c76d1..40152b9ad772 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/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 @@ nla_put_failure:
 	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 @@ nla_put_failure:
 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 @@ nla_put_failure:
 	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 @@ out:
 	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);
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index d88841fbc560..859cb303bb91 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/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));
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index b642c0b2495c..47b80fd0d2c3 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/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);
 
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index 9ee5fa551fa6..9da4b8462004 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/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>