net/sched: Introduce action ct

Allow sending a packet to conntrack module for connection tracking.

The packet will be marked with conntrack connection's state, and
any metadata such as conntrack mark and label. This state metadata
can later be matched against with tc classifers, for example with the
flower classifier as below.

In addition to committing new connections the user can optionally
specific a zone to track within, set a mark/label and configure nat
with an address range and port range.

Usage is as follows:
$ tc qdisc add dev ens1f0_0 ingress
$ tc qdisc add dev ens1f0_1 ingress

$ tc filter add dev ens1f0_0 ingress \
  prio 1 chain 0 proto ip \
  flower ip_proto tcp ct_state -trk \
  action ct zone 2 pipe \
  action goto chain 2
$ tc filter add dev ens1f0_0 ingress \
  prio 1 chain 2 proto ip \
  flower ct_state +trk+new \
  action ct zone 2 commit mark 0xbb nat src addr 5.5.5.7 pipe \
  action mirred egress redirect dev ens1f0_1
$ tc filter add dev ens1f0_0 ingress \
  prio 1 chain 2 proto ip \
  flower ct_zone 2 ct_mark 0xbb ct_state +trk+est \
  action ct nat pipe \
  action mirred egress redirect dev ens1f0_1

$ tc filter add dev ens1f0_1 ingress \
  prio 1 chain 0 proto ip \
  flower ip_proto tcp ct_state -trk \
  action ct zone 2 pipe \
  action goto chain 1
$ tc filter add dev ens1f0_1 ingress \
  prio 1 chain 1 proto ip \
  flower ct_zone 2 ct_mark 0xbb ct_state +trk+est \
  action ct nat pipe \
  action mirred egress redirect dev ens1f0_0
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>

Changelog:
V5->V6:
	Added CONFIG_NF_DEFRAG_IPV6 in handle fragments ipv6 case
V4->V5:
	Reordered nf_conntrack_put() in tcf_ct_skb_nfct_cached()
V3->V4:
	Added strict_start_type for act_ct policy
V2->V3:
	Fixed david's comments: Removed extra newline after rcu in tcf_ct_params , and indent of break in act_ct.c
V1->V2:
	Fixed parsing of ranges TCA_CT_NAT_IPV6_MAX as 'else' case overwritten ipv4 max
	Refactored NAT_PORT_MIN_MAX range handling as well
	Added ipv4/ipv6 defragmentation
	Removed extra skb pull push of nw offset in exectute nat
	Refactored tcf_ct_skb_network_trim after pull
	Removed TCA_ACT_CT define
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/flow_offload.h

@@ -129,6 +129,7 @@ enum flow_action_id {
 	FLOW_ACTION_QUEUE,
 	FLOW_ACTION_SAMPLE,
 	FLOW_ACTION_POLICE,
+	FLOW_ACTION_CT,
 };
 
 /* This is mirroring enum pedit_header_type definition for easy mapping between
@@ -178,6 +179,10 @@ struct flow_action_entry {
 			s64			burst;
 			u64			rate_bytes_ps;
 		} police;
+		struct {				/* FLOW_ACTION_CT */
+			int action;
+			u16 zone;
+		} ct;
 	};
 };
 

include/net/tc_act/tc_ct.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_TC_CT_H
+#define __NET_TC_CT_H
+
+#include <net/act_api.h>
+#include <uapi/linux/tc_act/tc_ct.h>
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_conntrack_labels.h>
+
+struct tcf_ct_params {
+	struct nf_conn *tmpl;
+	u16 zone;
+
+	u32 mark;
+	u32 mark_mask;
+
+	u32 labels[NF_CT_LABELS_MAX_SIZE / sizeof(u32)];
+	u32 labels_mask[NF_CT_LABELS_MAX_SIZE / sizeof(u32)];
+
+	struct nf_nat_range2 range;
+	bool ipv4_range;
+
+	u16 ct_action;
+
+	struct rcu_head rcu;
+};
+
+struct tcf_ct {
+	struct tc_action common;
+	struct tcf_ct_params __rcu *params;
+};
+
+#define to_ct(a) ((struct tcf_ct *)a)
+#define to_ct_params(a) ((struct tcf_ct_params *) \
+			 rtnl_dereference((to_ct(a)->params)))
+
+static inline uint16_t tcf_ct_zone(const struct tc_action *a)
+{
+	return to_ct_params(a)->zone;
+}
+
+static inline int tcf_ct_action(const struct tc_action *a)
+{
+	return to_ct_params(a)->ct_action;
+}
+
+#else
+static inline uint16_t tcf_ct_zone(const struct tc_action *a) { return 0; }
+static inline int tcf_ct_action(const struct tc_action *a) { return 0; }
+#endif /* CONFIG_NF_CONNTRACK */
+
+static inline bool is_tcf_ct(const struct tc_action *a)
+{
+#if defined(CONFIG_NET_CLS_ACT) && IS_ENABLED(CONFIG_NF_CONNTRACK)
+	if (a->ops && a->ops->id == TCA_ID_CT)
+		return true;
+#endif
+	return false;
+}
+
+#endif /* __NET_TC_CT_H */

include/uapi/linux/pkt_cls.h

@@ -106,6 +106,7 @@ enum tca_id {
 	TCA_ID_SAMPLE = TCA_ACT_SAMPLE,
 	TCA_ID_CTINFO,
 	TCA_ID_MPLS,
+	TCA_ID_CT,
 	/* other actions go here */
 	__TCA_ID_MAX = 255
 };

include/uapi/linux/tc_act/tc_ct.h

+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __UAPI_TC_CT_H
+#define __UAPI_TC_CT_H
+
+#include <linux/types.h>
+#include <linux/pkt_cls.h>
+
+enum {
+	TCA_CT_UNSPEC,
+	TCA_CT_PARMS,
+	TCA_CT_TM,
+	TCA_CT_ACTION,		/* u16 */
+	TCA_CT_ZONE,		/* u16 */
+	TCA_CT_MARK,		/* u32 */
+	TCA_CT_MARK_MASK,	/* u32 */
+	TCA_CT_LABELS,		/* u128 */
+	TCA_CT_LABELS_MASK,	/* u128 */
+	TCA_CT_NAT_IPV4_MIN,	/* be32 */
+	TCA_CT_NAT_IPV4_MAX,	/* be32 */
+	TCA_CT_NAT_IPV6_MIN,	/* struct in6_addr */
+	TCA_CT_NAT_IPV6_MAX,	/* struct in6_addr */
+	TCA_CT_NAT_PORT_MIN,	/* be16 */
+	TCA_CT_NAT_PORT_MAX,	/* be16 */
+	TCA_CT_PAD,
+	__TCA_CT_MAX
+};
+
+#define TCA_CT_MAX (__TCA_CT_MAX - 1)
+
+#define TCA_CT_ACT_COMMIT	(1 << 0)
+#define TCA_CT_ACT_FORCE	(1 << 1)
+#define TCA_CT_ACT_CLEAR	(1 << 2)
+#define TCA_CT_ACT_NAT		(1 << 3)
+#define TCA_CT_ACT_NAT_SRC	(1 << 4)
+#define TCA_CT_ACT_NAT_DST	(1 << 5)
+
+struct tc_ct {
+	tc_gen;
+};
+
+#endif /* __UAPI_TC_CT_H */

net/sched/Kconfig

@@ -940,6 +940,17 @@ config NET_ACT_TUNNEL_KEY
 	  To compile this code as a module, choose M here: the
 	  module will be called act_tunnel_key.
 
+config NET_ACT_CT
+        tristate "connection tracking tc action"
+        depends on NET_CLS_ACT && NF_CONNTRACK
+        help
+	  Say Y here to allow sending the packets to conntrack module.
+
+	  If unsure, say N.
+
+	  To compile this code as a module, choose M here: the
+	  module will be called act_ct.
+
 config NET_IFE_SKBMARK
         tristate "Support to encoding decoding skb mark on IFE action"
         depends on NET_ACT_IFE

net/sched/Makefile

@@ -29,6 +29,7 @@ obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
 obj-$(CONFIG_NET_IFE_SKBPRIO)	+= act_meta_skbprio.o
 obj-$(CONFIG_NET_IFE_SKBTCINDEX)	+= act_meta_skbtcindex.o
 obj-$(CONFIG_NET_ACT_TUNNEL_KEY)+= act_tunnel_key.o
+obj-$(CONFIG_NET_ACT_CT)	+= act_ct.o
 obj-$(CONFIG_NET_SCH_FIFO)	+= sch_fifo.o
 obj-$(CONFIG_NET_SCH_CBQ)	+= sch_cbq.o
 obj-$(CONFIG_NET_SCH_HTB)	+= sch_htb.o

net/sched/act_ct.c

+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* -
+ * net/sched/act_ct.c  Connection Tracking action
+ *
+ * Authors:   Paul Blakey <paulb@mellanox.com>
+ *            Yossi Kuperman <yossiku@mellanox.com>
+ *            Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/pkt_cls.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/act_api.h>
+#include <net/ip.h>
+#include <net/ipv6_frag.h>
+#include <uapi/linux/tc_act/tc_ct.h>
+#include <net/tc_act/tc_ct.h>
+
+#include <linux/netfilter/nf_nat.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+
+static struct tc_action_ops act_ct_ops;
+static unsigned int ct_net_id;
+
+struct tc_ct_action_net {
+	struct tc_action_net tn; /* Must be first */
+	bool labels;
+};
+
+/* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
+static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
+				   u16 zone_id, bool force)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return false;
+	if (!net_eq(net, read_pnet(&ct->ct_net)))
+		return false;
+	if (nf_ct_zone(ct)->id != zone_id)
+		return false;
+
+	/* Force conntrack entry direction. */
+	if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
+		if (nf_ct_is_confirmed(ct))
+			nf_ct_kill(ct);
+
+		nf_conntrack_put(&ct->ct_general);
+		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+
+		return false;
+	}
+
+	return true;
+}
+
+/* Trim the skb to the length specified by the IP/IPv6 header,
+ * removing any trailing lower-layer padding. This prepares the skb
+ * for higher-layer processing that assumes skb->len excludes padding
+ * (such as nf_ip_checksum). The caller needs to pull the skb to the
+ * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
+ */
+static int tcf_ct_skb_network_trim(struct sk_buff *skb, int family)
+{
+	unsigned int len;
+	int err;
+
+	switch (family) {
+	case NFPROTO_IPV4:
+		len = ntohs(ip_hdr(skb)->tot_len);
+		break;
+	case NFPROTO_IPV6:
+		len = sizeof(struct ipv6hdr)
+			+ ntohs(ipv6_hdr(skb)->payload_len);
+		break;
+	default:
+		len = skb->len;
+	}
+
+	err = pskb_trim_rcsum(skb, len);
+
+	return err;
+}
+
+static u8 tcf_ct_skb_nf_family(struct sk_buff *skb)
+{
+	u8 family = NFPROTO_UNSPEC;
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		family = NFPROTO_IPV4;
+		break;
+	case htons(ETH_P_IPV6):
+		family = NFPROTO_IPV6;
+		break;
+	default:
+		break;
+	}
+
+	return family;
+}
+
+static int tcf_ct_ipv4_is_fragment(struct sk_buff *skb, bool *frag)
+{
+	unsigned int len;
+
+	len =  skb_network_offset(skb) + sizeof(struct iphdr);
+	if (unlikely(skb->len < len))
+		return -EINVAL;
+	if (unlikely(!pskb_may_pull(skb, len)))
+		return -ENOMEM;
+
+	*frag = ip_is_fragment(ip_hdr(skb));
+	return 0;
+}
+
+static int tcf_ct_ipv6_is_fragment(struct sk_buff *skb, bool *frag)
+{
+	unsigned int flags = 0, len, payload_ofs = 0;
+	unsigned short frag_off;
+	int nexthdr;
+
+	len =  skb_network_offset(skb) + sizeof(struct ipv6hdr);
+	if (unlikely(skb->len < len))
+		return -EINVAL;
+	if (unlikely(!pskb_may_pull(skb, len)))
+		return -ENOMEM;
+
+	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
+	if (unlikely(nexthdr < 0))
+		return -EPROTO;
+
+	*frag = flags & IP6_FH_F_FRAG;
+	return 0;
+}
+
+static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
+				   u8 family, u16 zone)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	int err = 0;
+	bool frag;
+
+	/* Previously seen (loopback)? Ignore. */
+	ct = nf_ct_get(skb, &ctinfo);
+	if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
+		return 0;
+
+	if (family == NFPROTO_IPV4)
+		err = tcf_ct_ipv4_is_fragment(skb, &frag);
+	else
+		err = tcf_ct_ipv6_is_fragment(skb, &frag);
+	if (err || !frag)
+		return err;
+
+	skb_get(skb);
+
+	if (family == NFPROTO_IPV4) {
+		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
+
+		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+		local_bh_disable();
+		err = ip_defrag(net, skb, user);
+		local_bh_enable();
+		if (err && err != -EINPROGRESS)
+			goto out_free;
+	} else { /* NFPROTO_IPV6 */
+#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
+		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
+
+		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
+		err = nf_ct_frag6_gather(net, skb, user);
+		if (err && err != -EINPROGRESS)
+			goto out_free;
+#else
+		err = -EOPNOTSUPP;
+		goto out_free;
+#endif
+	}
+
+	skb_clear_hash(skb);
+	skb->ignore_df = 1;
+	return err;
+
+out_free:
+	kfree_skb(skb);
+	return err;
+}
+
+static void tcf_ct_params_free(struct rcu_head *head)
+{
+	struct tcf_ct_params *params = container_of(head,
+						    struct tcf_ct_params, rcu);
+
+	if (params->tmpl)
+		nf_conntrack_put(&params->tmpl->ct_general);
+	kfree(params);
+}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+/* Modelled after nf_nat_ipv[46]_fn().
+ * range is only used for new, uninitialized NAT state.
+ * Returns either NF_ACCEPT or NF_DROP.
+ */
+static int ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
+			  enum ip_conntrack_info ctinfo,
+			  const struct nf_nat_range2 *range,
+			  enum nf_nat_manip_type maniptype)
+{
+	int hooknum, err = NF_ACCEPT;
+
+	/* See HOOK2MANIP(). */
+	if (maniptype == NF_NAT_MANIP_SRC)
+		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
+	else
+		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
+
+	switch (ctinfo) {
+	case IP_CT_RELATED:
+	case IP_CT_RELATED_REPLY:
+		if (skb->protocol == htons(ETH_P_IP) &&
+		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
+			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
+							   hooknum))
+				err = NF_DROP;
+			goto out;
+		} else if (IS_ENABLED(CONFIG_IPV6) &&
+			   skb->protocol == htons(ETH_P_IPV6)) {
+			__be16 frag_off;
+			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+			int hdrlen = ipv6_skip_exthdr(skb,
+						      sizeof(struct ipv6hdr),
+						      &nexthdr, &frag_off);
+
+			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
+				if (!nf_nat_icmpv6_reply_translation(skb, ct,
+								     ctinfo,
+								     hooknum,
+								     hdrlen))
+					err = NF_DROP;
+				goto out;
+			}
+		}
+		/* Non-ICMP, fall thru to initialize if needed. */
+		/* fall through */
+	case IP_CT_NEW:
+		/* Seen it before?  This can happen for loopback, retrans,
+		 * or local packets.
+		 */
+		if (!nf_nat_initialized(ct, maniptype)) {
+			/* Initialize according to the NAT action. */
+			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
+				/* Action is set up to establish a new
+				 * mapping.
+				 */
+				? nf_nat_setup_info(ct, range, maniptype)
+				: nf_nat_alloc_null_binding(ct, hooknum);
+			if (err != NF_ACCEPT)
+				goto out;
+		}
+		break;
+
+	case IP_CT_ESTABLISHED:
+	case IP_CT_ESTABLISHED_REPLY:
+		break;
+
+	default:
+		err = NF_DROP;
+		goto out;
+	}
+
+	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
+out:
+	return err;
+}
+#endif /* CONFIG_NF_NAT */
+
+static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
+	u32 new_mark;
+
+	if (!mask)
+		return;
+
+	new_mark = mark | (ct->mark & ~(mask));
+	if (ct->mark != new_mark) {
+		ct->mark = new_mark;
+		if (nf_ct_is_confirmed(ct))
+			nf_conntrack_event_cache(IPCT_MARK, ct);
+	}
+#endif
+}
+
+static void tcf_ct_act_set_labels(struct nf_conn *ct,
+				  u32 *labels,
+				  u32 *labels_m)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)
+	size_t labels_sz = FIELD_SIZEOF(struct tcf_ct_params, labels);
+
+	if (!memchr_inv(labels_m, 0, labels_sz))
+		return;
+
+	nf_connlabels_replace(ct, labels, labels_m, 4);
+#endif
+}
+
+static int tcf_ct_act_nat(struct sk_buff *skb,
+			  struct nf_conn *ct,
+			  enum ip_conntrack_info ctinfo,
+			  int ct_action,
+			  struct nf_nat_range2 *range,
+			  bool commit)
+{
+#if IS_ENABLED(CONFIG_NF_NAT)
+	enum nf_nat_manip_type maniptype;
+
+	if (!(ct_action & TCA_CT_ACT_NAT))
+		return NF_ACCEPT;
+
+	/* Add NAT extension if not confirmed yet. */
+	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
+		return NF_DROP;   /* Can't NAT. */
+
+	if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) &&
+	    (ctinfo != IP_CT_RELATED || commit)) {
+		/* NAT an established or related connection like before. */
+		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
+			/* This is the REPLY direction for a connection
+			 * for which NAT was applied in the forward
+			 * direction.  Do the reverse NAT.
+			 */
+			maniptype = ct->status & IPS_SRC_NAT
+				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
+		else
+			maniptype = ct->status & IPS_SRC_NAT
+				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
+	} else if (ct_action & TCA_CT_ACT_NAT_SRC) {
+		maniptype = NF_NAT_MANIP_SRC;
+	} else if (ct_action & TCA_CT_ACT_NAT_DST) {
+		maniptype = NF_NAT_MANIP_DST;
+	} else {
+		return NF_ACCEPT;
+	}
+
+	return ct_nat_execute(skb, ct, ctinfo, range, maniptype);
+#else
+	return NF_ACCEPT;
+#endif
+}
+
+static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
+		      struct tcf_result *res)
+{
+	struct net *net = dev_net(skb->dev);
+	bool cached, commit, clear, force;
+	enum ip_conntrack_info ctinfo;
+	struct tcf_ct *c = to_ct(a);
+	struct nf_conn *tmpl = NULL;
+	struct nf_hook_state state;
+	int nh_ofs, err, retval;
+	struct tcf_ct_params *p;
+	struct nf_conn *ct;
+	u8 family;
+
+	p = rcu_dereference_bh(c->params);
+
+	retval = READ_ONCE(c->tcf_action);
+	commit = p->ct_action & TCA_CT_ACT_COMMIT;
+	clear = p->ct_action & TCA_CT_ACT_CLEAR;
+	force = p->ct_action & TCA_CT_ACT_FORCE;
+	tmpl = p->tmpl;
+
+	if (clear) {
+		ct = nf_ct_get(skb, &ctinfo);
+		if (ct) {
+			nf_conntrack_put(&ct->ct_general);
+			nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+		}
+
+		goto out;
+	}
+
+	family = tcf_ct_skb_nf_family(skb);
+	if (family == NFPROTO_UNSPEC)
+		goto drop;
+
+	/* The conntrack module expects to be working at L3.
+	 * We also try to pull the IPv4/6 header to linear area
+	 */
+	nh_ofs = skb_network_offset(skb);
+	skb_pull_rcsum(skb, nh_ofs);
+	err = tcf_ct_handle_fragments(net, skb, family, p->zone);
+	if (err == -EINPROGRESS) {
+		retval = TC_ACT_STOLEN;
+		goto out;
+	}
+	if (err)
+		goto drop;
+
+	err = tcf_ct_skb_network_trim(skb, family);
+	if (err)
+		goto drop;
+
+	/* If we are recirculating packets to match on ct fields and
+	 * committing with a separate ct action, then we don't need to
+	 * actually run the packet through conntrack twice unless it's for a
+	 * different zone.
+	 */
+	cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
+	if (!cached) {
+		/* Associate skb with specified zone. */
+		if (tmpl) {
+			ct = nf_ct_get(skb, &ctinfo);
+			if (skb_nfct(skb))
+				nf_conntrack_put(skb_nfct(skb));
+			nf_conntrack_get(&tmpl->ct_general);
+			nf_ct_set(skb, tmpl, IP_CT_NEW);
+		}
+
+		state.hook = NF_INET_PRE_ROUTING;
+		state.net = net;
+		state.pf = family;
+		err = nf_conntrack_in(skb, &state);
+		if (err != NF_ACCEPT)
+			goto out_push;
+	}
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		goto out_push;
+	nf_ct_deliver_cached_events(ct);
+
+	err = tcf_ct_act_nat(skb, ct, ctinfo, p->ct_action, &p->range, commit);
+	if (err != NF_ACCEPT)
+		goto drop;
+
+	if (commit) {
+		tcf_ct_act_set_mark(ct, p->mark, p->mark_mask);
+		tcf_ct_act_set_labels(ct, p->labels, p->labels_mask);
+
+		/* This will take care of sending queued events
+		 * even if the connection is already confirmed.
+		 */
+		nf_conntrack_confirm(skb);
+	}
+
+out_push:
+	skb_push_rcsum(skb, nh_ofs);
+
+out:
+	bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), skb);
+	return retval;
+
+drop:
+	qstats_drop_inc(this_cpu_ptr(a->cpu_qstats));
+	return TC_ACT_SHOT;
+}
+
+static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
+	[TCA_CT_UNSPEC] = { .strict_start_type = TCA_CT_UNSPEC + 1 },
+	[TCA_CT_ACTION] = { .type = NLA_U16 },
+	[TCA_CT_PARMS] = { .type = NLA_EXACT_LEN, .len = sizeof(struct tc_ct) },
+	[TCA_CT_ZONE] = { .type = NLA_U16 },
+	[TCA_CT_MARK] = { .type = NLA_U32 },
+	[TCA_CT_MARK_MASK] = { .type = NLA_U32 },
+	[TCA_CT_LABELS] = { .type = NLA_BINARY,
+			    .len = 128 / BITS_PER_BYTE },
+	[TCA_CT_LABELS_MASK] = { .type = NLA_BINARY,
+				 .len = 128 / BITS_PER_BYTE },
+	[TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 },
+	[TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 },
+	[TCA_CT_NAT_IPV6_MIN] = { .type = NLA_EXACT_LEN,
+				  .len = sizeof(struct in6_addr) },
+	[TCA_CT_NAT_IPV6_MAX] = { .type = NLA_EXACT_LEN,
+				   .len = sizeof(struct in6_addr) },
+	[TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
+	[TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
+};
+
+static int tcf_ct_fill_params_nat(struct tcf_ct_params *p,
+				  struct tc_ct *parm,
+				  struct nlattr **tb,
+				  struct netlink_ext_ack *extack)
+{
+	struct nf_nat_range2 *range;
+
+	if (!(p->ct_action & TCA_CT_ACT_NAT))
+		return 0;
+
+	if (!IS_ENABLED(CONFIG_NF_NAT)) {
+		NL_SET_ERR_MSG_MOD(extack, "Netfilter nat isn't enabled in kernel");
+		return -EOPNOTSUPP;
+	}
+
+	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
+		return 0;
+
+	if ((p->ct_action & TCA_CT_ACT_NAT_SRC) &&
+	    (p->ct_action & TCA_CT_ACT_NAT_DST)) {
+		NL_SET_ERR_MSG_MOD(extack, "dnat and snat can't be enabled at the same time");
+		return -EOPNOTSUPP;
+	}
+
+	range = &p->range;
+	if (tb[TCA_CT_NAT_IPV4_MIN]) {
+		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV4_MAX];
+
+		p->ipv4_range = true;
+		range->flags |= NF_NAT_RANGE_MAP_IPS;
+		range->min_addr.ip =
+			nla_get_in_addr(tb[TCA_CT_NAT_IPV4_MIN]);
+
+		range->max_addr.ip = max_attr ?
+				     nla_get_in_addr(max_attr) :
+				     range->min_addr.ip;
+	} else if (tb[TCA_CT_NAT_IPV6_MIN]) {
+		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV6_MAX];
+
+		p->ipv4_range = false;
+		range->flags |= NF_NAT_RANGE_MAP_IPS;
+		range->min_addr.in6 =
+			nla_get_in6_addr(tb[TCA_CT_NAT_IPV6_MIN]);
+
+		range->max_addr.in6 = max_attr ?
+				      nla_get_in6_addr(max_attr) :
+				      range->min_addr.in6;
+	}
+
+	if (tb[TCA_CT_NAT_PORT_MIN]) {
+		range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+		range->min_proto.all = nla_get_be16(tb[TCA_CT_NAT_PORT_MIN]);
+
+		range->max_proto.all = tb[TCA_CT_NAT_PORT_MAX] ?
+				       nla_get_be16(tb[TCA_CT_NAT_PORT_MAX]) :
+				       range->min_proto.all;
+	}
+
+	return 0;
+}
+
+static void tcf_ct_set_key_val(struct nlattr **tb,
+			       void *val, int val_type,
+			       void *mask, int mask_type,
+			       int len)
+{
+	if (!tb[val_type])
+		return;
+	nla_memcpy(val, tb[val_type], len);
+
+	if (!mask)
+		return;
+
+	if (mask_type == TCA_CT_UNSPEC || !tb[mask_type])
+		memset(mask, 0xff, len);
+	else
+		nla_memcpy(mask, tb[mask_type], len);
+}
+
+static int tcf_ct_fill_params(struct net *net,
+			      struct tcf_ct_params *p,
+			      struct tc_ct *parm,
+			      struct nlattr **tb,
+			      struct netlink_ext_ack *extack)
+{
+	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
+	struct nf_conntrack_zone zone;
+	struct nf_conn *tmpl;
+	int err;
+
+	p->zone = NF_CT_DEFAULT_ZONE_ID;
+
+	tcf_ct_set_key_val(tb,
+			   &p->ct_action, TCA_CT_ACTION,
+			   NULL, TCA_CT_UNSPEC,
+			   sizeof(p->ct_action));
+
+	if (p->ct_action & TCA_CT_ACT_CLEAR)
+		return 0;
+
+	err = tcf_ct_fill_params_nat(p, parm, tb, extack);
+	if (err)
+		return err;
+
+	if (tb[TCA_CT_MARK]) {
+		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)) {
+			NL_SET_ERR_MSG_MOD(extack, "Conntrack mark isn't enabled.");
+			return -EOPNOTSUPP;
+		}
+		tcf_ct_set_key_val(tb,
+				   &p->mark, TCA_CT_MARK,
+				   &p->mark_mask, TCA_CT_MARK_MASK,
+				   sizeof(p->mark));
+	}
+
+	if (tb[TCA_CT_LABELS]) {
+		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)) {
+			NL_SET_ERR_MSG_MOD(extack, "Conntrack labels isn't enabled.");
+			return -EOPNOTSUPP;
+		}
+
+		if (!tn->labels) {
+			NL_SET_ERR_MSG_MOD(extack, "Failed to set connlabel length");
+			return -EOPNOTSUPP;
+		}
+		tcf_ct_set_key_val(tb,
+				   p->labels, TCA_CT_LABELS,
+				   p->labels_mask, TCA_CT_LABELS_MASK,
+				   sizeof(p->labels));
+	}
+
+	if (tb[TCA_CT_ZONE]) {
+		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) {
+			NL_SET_ERR_MSG_MOD(extack, "Conntrack zones isn't enabled.");
+			return -EOPNOTSUPP;
+		}
+
+		tcf_ct_set_key_val(tb,
+				   &p->zone, TCA_CT_ZONE,
+				   NULL, TCA_CT_UNSPEC,
+				   sizeof(p->zone));
+	}
+
+	if (p->zone == NF_CT_DEFAULT_ZONE_ID)
+		return 0;
+
+	nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0);
+	tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL);
+	if (!tmpl) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template");
+		return -ENOMEM;
+	}
+	__set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
+	nf_conntrack_get(&tmpl->ct_general);
+	p->tmpl = tmpl;
+
+	return 0;
+}
+
+static int tcf_ct_init(struct net *net, struct nlattr *nla,
+		       struct nlattr *est, struct tc_action **a,
+		       int replace, int bind, bool rtnl_held,
+		       struct tcf_proto *tp,
+		       struct netlink_ext_ack *extack)
+{
+	struct tc_action_net *tn = net_generic(net, ct_net_id);
+	struct tcf_ct_params *params = NULL;
+	struct nlattr *tb[TCA_CT_MAX + 1];
+	struct tcf_chain *goto_ch = NULL;
+	struct tc_ct *parm;
+	struct tcf_ct *c;
+	int err, res = 0;
+
+	if (!nla) {
+		NL_SET_ERR_MSG_MOD(extack, "Ct requires attributes to be passed");
+		return -EINVAL;
+	}
+
+	err = nla_parse_nested(tb, TCA_CT_MAX, nla, ct_policy, extack);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_CT_PARMS]) {
+		NL_SET_ERR_MSG_MOD(extack, "Missing required ct parameters");
+		return -EINVAL;
+	}
+	parm = nla_data(tb[TCA_CT_PARMS]);
+
+	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
+	if (err < 0)
+		return err;
+
+	if (!err) {
+		err = tcf_idr_create(tn, parm->index, est, a,
+				     &act_ct_ops, bind, true);
+		if (err) {
+			tcf_idr_cleanup(tn, parm->index);
+			return err;
+		}
+		res = ACT_P_CREATED;
+	} else {
+		if (bind)
+			return 0;
+
+		if (!replace) {
+			tcf_idr_release(*a, bind);
+			return -EEXIST;
+		}
+	}
+	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
+	if (err < 0)
+		goto cleanup;
+
+	c = to_ct(*a);
+
+	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	if (unlikely(!params)) {
+		err = -ENOMEM;
+		goto cleanup;
+	}
+
+	err = tcf_ct_fill_params(net, params, parm, tb, extack);
+	if (err)
+		goto cleanup;
+
+	spin_lock_bh(&c->tcf_lock);
+	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
+	rcu_swap_protected(c->params, params, lockdep_is_held(&c->tcf_lock));
+	spin_unlock_bh(&c->tcf_lock);
+
+	if (goto_ch)
+		tcf_chain_put_by_act(goto_ch);
+	if (params)
+		kfree_rcu(params, rcu);
+	if (res == ACT_P_CREATED)
+		tcf_idr_insert(tn, *a);
+
+	return res;
+
+cleanup:
+	if (goto_ch)
+		tcf_chain_put_by_act(goto_ch);
+	kfree(params);
+	tcf_idr_release(*a, bind);
+	return err;
+}
+
+static void tcf_ct_cleanup(struct tc_action *a)
+{
+	struct tcf_ct_params *params;
+	struct tcf_ct *c = to_ct(a);
+
+	params = rcu_dereference_protected(c->params, 1);
+	if (params)
+		call_rcu(&params->rcu, tcf_ct_params_free);
+}
+
+static int tcf_ct_dump_key_val(struct sk_buff *skb,
+			       void *val, int val_type,
+			       void *mask, int mask_type,
+			       int len)
+{
+	int err;
+
+	if (mask && !memchr_inv(mask, 0, len))
+		return 0;
+
+	err = nla_put(skb, val_type, len, val);
+	if (err)
+		return err;
+
+	if (mask_type != TCA_CT_UNSPEC) {
+		err = nla_put(skb, mask_type, len, mask);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p)
+{
+	struct nf_nat_range2 *range = &p->range;
+
+	if (!(p->ct_action & TCA_CT_ACT_NAT))
+		return 0;
+
+	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
+		return 0;
+
+	if (range->flags & NF_NAT_RANGE_MAP_IPS) {
+		if (p->ipv4_range) {
+			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MIN,
+					    range->min_addr.ip))
+				return -1;
+			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MAX,
+					    range->max_addr.ip))
+				return -1;
+		} else {
+			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MIN,
+					     &range->min_addr.in6))
+				return -1;
+			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MAX,
+					     &range->max_addr.in6))
+				return -1;
+		}
+	}
+
+	if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MIN,
+				 range->min_proto.all))
+			return -1;
+		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MAX,
+				 range->max_proto.all))
+			return -1;
+	}
+
+	return 0;
+}
+
+static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
+			      int bind, int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_ct *c = to_ct(a);
+	struct tcf_ct_params *p;
+
+	struct tc_ct opt = {
+		.index   = c->tcf_index,
+		.refcnt  = refcount_read(&c->tcf_refcnt) - ref,
+		.bindcnt = atomic_read(&c->tcf_bindcnt) - bind,
+	};
+	struct tcf_t t;
+
+	spin_lock_bh(&c->tcf_lock);
+	p = rcu_dereference_protected(c->params,
+				      lockdep_is_held(&c->tcf_lock));
+	opt.action = c->tcf_action;
+
+	if (tcf_ct_dump_key_val(skb,
+				&p->ct_action, TCA_CT_ACTION,
+				NULL, TCA_CT_UNSPEC,
+				sizeof(p->ct_action)))
+		goto nla_put_failure;
+
+	if (p->ct_action & TCA_CT_ACT_CLEAR)
+		goto skip_dump;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
+	    tcf_ct_dump_key_val(skb,
+				&p->mark, TCA_CT_MARK,
+				&p->mark_mask, TCA_CT_MARK_MASK,
+				sizeof(p->mark)))
+		goto nla_put_failure;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+	    tcf_ct_dump_key_val(skb,
+				p->labels, TCA_CT_LABELS,
+				p->labels_mask, TCA_CT_LABELS_MASK,
+				sizeof(p->labels)))
+		goto nla_put_failure;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    tcf_ct_dump_key_val(skb,
+				&p->zone, TCA_CT_ZONE,
+				NULL, TCA_CT_UNSPEC,
+				sizeof(p->zone)))
+		goto nla_put_failure;
+
+	if (tcf_ct_dump_nat(skb, p))
+		goto nla_put_failure;
+
+skip_dump:
+	if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	tcf_tm_dump(&t, &c->tcf_tm);
+	if (nla_put_64bit(skb, TCA_CT_TM, sizeof(t), &t, TCA_CT_PAD))
+		goto nla_put_failure;
+	spin_unlock_bh(&c->tcf_lock);
+
+	return skb->len;
+nla_put_failure:
+	spin_unlock_bh(&c->tcf_lock);
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int tcf_ct_walker(struct net *net, struct sk_buff *skb,
+			 struct netlink_callback *cb, int type,
+			 const struct tc_action_ops *ops,
+			 struct netlink_ext_ack *extack)
+{
+	struct tc_action_net *tn = net_generic(net, ct_net_id);
+
+	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_ct_search(struct net *net, struct tc_action **a, u32 index)
+{
+	struct tc_action_net *tn = net_generic(net, ct_net_id);
+
+	return tcf_idr_search(tn, a, index);
+}
+
+static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
+			     u64 lastuse, bool hw)
+{
+	struct tcf_ct *c = to_ct(a);
+
+	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
+
+	if (hw)
+		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
+				   bytes, packets);
+	c->tcf_tm.lastuse = max_t(u64, c->tcf_tm.lastuse, lastuse);
+}
+
+static struct tc_action_ops act_ct_ops = {
+	.kind		=	"ct",
+	.id		=	TCA_ID_CT,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_ct_act,
+	.dump		=	tcf_ct_dump,
+	.init		=	tcf_ct_init,
+	.cleanup	=	tcf_ct_cleanup,
+	.walk		=	tcf_ct_walker,
+	.lookup		=	tcf_ct_search,
+	.stats_update	=	tcf_stats_update,
+	.size		=	sizeof(struct tcf_ct),
+};
+
+static __net_init int ct_init_net(struct net *net)
+{
+	unsigned int n_bits = FIELD_SIZEOF(struct tcf_ct_params, labels) * 8;
+	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
+
+	if (nf_connlabels_get(net, n_bits - 1)) {
+		tn->labels = false;
+		pr_err("act_ct: Failed to set connlabels length");
+	} else {
+		tn->labels = true;
+	}
+
+	return tc_action_net_init(&tn->tn, &act_ct_ops);
+}
+
+static void __net_exit ct_exit_net(struct list_head *net_list)
+{
+	struct net *net;
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list) {
+		struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
+
+		if (tn->labels)
+			nf_connlabels_put(net);
+	}
+	rtnl_unlock();
+
+	tc_action_net_exit(net_list, ct_net_id);
+}
+
+static struct pernet_operations ct_net_ops = {
+	.init = ct_init_net,
+	.exit_batch = ct_exit_net,
+	.id   = &ct_net_id,
+	.size = sizeof(struct tc_ct_action_net),
+};
+
+static int __init ct_init_module(void)
+{
+	return tcf_register_action(&act_ct_ops, &ct_net_ops);
+}
+
+static void __exit ct_cleanup_module(void)
+{
+	tcf_unregister_action(&act_ct_ops, &ct_net_ops);
+}
+
+module_init(ct_init_module);
+module_exit(ct_cleanup_module);
+MODULE_AUTHOR("Paul Blakey <paulb@mellanox.com>");
+MODULE_AUTHOR("Yossi Kuperman <yossiku@mellanox.com>");
+MODULE_AUTHOR("Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>");
+MODULE_DESCRIPTION("Connection tracking action");
+MODULE_LICENSE("GPL v2");
+

net/sched/cls_api.c

@@ -35,6 +35,7 @@
 #include <net/tc_act/tc_police.h>
 #include <net/tc_act/tc_sample.h>
 #include <net/tc_act/tc_skbedit.h>
+#include <net/tc_act/tc_ct.h>
 
 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
 
@@ -3266,6 +3267,10 @@ int tc_setup_flow_action(struct flow_action *flow_action,
 			entry->police.burst = tcf_police_tcfp_burst(act);
 			entry->police.rate_bytes_ps =
 				tcf_police_rate_bytes_ps(act);
+		} else if (is_tcf_ct(act)) {
+			entry->id = FLOW_ACTION_CT;
+			entry->ct.action = tcf_ct_action(act);
+			entry->ct.zone = tcf_ct_zone(act);
 		} else {
 			goto err_out;
 		}