// 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 <linux/rhashtable.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 <net/netfilter/nf_flow_table.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/nf_conntrack_acct.h>

  #include <net/netfilter/ipv6/nf_defrag_ipv6.h>

  #include <uapi/linux/netfilter/nf_nat.h>

  static struct workqueue_struct *act_ct_wq;
  static struct rhashtable zones_ht;

  static DEFINE_MUTEX(zones_mutex);

  
  struct tcf_ct_flow_table {
  	struct rhash_head node; /* In zones tables */
  
  	struct rcu_work rwork;
  	struct nf_flowtable nf_ft;

  	refcount_t ref;

  	u16 zone;

  
  	bool dying;
  };
  
  static const struct rhashtable_params zones_params = {
  	.head_offset = offsetof(struct tcf_ct_flow_table, node),
  	.key_offset = offsetof(struct tcf_ct_flow_table, zone),
  	.key_len = sizeof_field(struct tcf_ct_flow_table, zone),
  	.automatic_shrinking = true,
  };

  static struct flow_action_entry *
  tcf_ct_flow_table_flow_action_get_next(struct flow_action *flow_action)
  {
  	int i = flow_action->num_entries++;
  
  	return &flow_action->entries[i];
  }
  
  static void tcf_ct_add_mangle_action(struct flow_action *action,
  				     enum flow_action_mangle_base htype,
  				     u32 offset,
  				     u32 mask,
  				     u32 val)
  {
  	struct flow_action_entry *entry;
  
  	entry = tcf_ct_flow_table_flow_action_get_next(action);
  	entry->id = FLOW_ACTION_MANGLE;
  	entry->mangle.htype = htype;
  	entry->mangle.mask = ~mask;
  	entry->mangle.offset = offset;
  	entry->mangle.val = val;
  }
  
  /* The following nat helper functions check if the inverted reverse tuple
   * (target) is different then the current dir tuple - meaning nat for ports
   * and/or ip is needed, and add the relevant mangle actions.
   */
  static void
  tcf_ct_flow_table_add_action_nat_ipv4(const struct nf_conntrack_tuple *tuple,
  				      struct nf_conntrack_tuple target,
  				      struct flow_action *action)
  {
  	if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
  					 offsetof(struct iphdr, saddr),
  					 0xFFFFFFFF,
  					 be32_to_cpu(target.src.u3.ip));
  	if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
  					 offsetof(struct iphdr, daddr),
  					 0xFFFFFFFF,
  					 be32_to_cpu(target.dst.u3.ip));
  }
  
  static void
  tcf_ct_add_ipv6_addr_mangle_action(struct flow_action *action,
  				   union nf_inet_addr *addr,
  				   u32 offset)
  {
  	int i;
  
  	for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i++)
  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
  					 i * sizeof(u32) + offset,
  					 0xFFFFFFFF, be32_to_cpu(addr->ip6[i]));
  }
  
  static void
  tcf_ct_flow_table_add_action_nat_ipv6(const struct nf_conntrack_tuple *tuple,
  				      struct nf_conntrack_tuple target,
  				      struct flow_action *action)
  {
  	if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
  		tcf_ct_add_ipv6_addr_mangle_action(action, &target.src.u3,
  						   offsetof(struct ipv6hdr,
  							    saddr));
  	if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
  		tcf_ct_add_ipv6_addr_mangle_action(action, &target.dst.u3,
  						   offsetof(struct ipv6hdr,
  							    daddr));
  }
  
  static void
  tcf_ct_flow_table_add_action_nat_tcp(const struct nf_conntrack_tuple *tuple,
  				     struct nf_conntrack_tuple target,
  				     struct flow_action *action)
  {
  	__be16 target_src = target.src.u.tcp.port;
  	__be16 target_dst = target.dst.u.tcp.port;
  
  	if (target_src != tuple->src.u.tcp.port)
  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
  					 offsetof(struct tcphdr, source),
  					 0xFFFF, be16_to_cpu(target_src));
  	if (target_dst != tuple->dst.u.tcp.port)
  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
  					 offsetof(struct tcphdr, dest),
  					 0xFFFF, be16_to_cpu(target_dst));
  }
  
  static void
  tcf_ct_flow_table_add_action_nat_udp(const struct nf_conntrack_tuple *tuple,
  				     struct nf_conntrack_tuple target,
  				     struct flow_action *action)
  {
  	__be16 target_src = target.src.u.udp.port;
  	__be16 target_dst = target.dst.u.udp.port;
  
  	if (target_src != tuple->src.u.udp.port)

  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP,

  					 offsetof(struct udphdr, source),
  					 0xFFFF, be16_to_cpu(target_src));
  	if (target_dst != tuple->dst.u.udp.port)

  		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP,

  					 offsetof(struct udphdr, dest),
  					 0xFFFF, be16_to_cpu(target_dst));
  }
  
  static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct,
  					      enum ip_conntrack_dir dir,
  					      struct flow_action *action)
  {
  	struct nf_conn_labels *ct_labels;
  	struct flow_action_entry *entry;

  	enum ip_conntrack_info ctinfo;

  	u32 *act_ct_labels;
  
  	entry = tcf_ct_flow_table_flow_action_get_next(action);
  	entry->id = FLOW_ACTION_CT_METADATA;
  #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
  	entry->ct_metadata.mark = ct->mark;
  #endif

  	ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
  					     IP_CT_ESTABLISHED_REPLY;
  	/* aligns with the CT reference on the SKB nf_ct_set */
  	entry->ct_metadata.cookie = (unsigned long)ct | ctinfo;

  
  	act_ct_labels = entry->ct_metadata.labels;
  	ct_labels = nf_ct_labels_find(ct);
  	if (ct_labels)
  		memcpy(act_ct_labels, ct_labels->bits, NF_CT_LABELS_MAX_SIZE);
  	else
  		memset(act_ct_labels, 0, NF_CT_LABELS_MAX_SIZE);
  }
  
  static int tcf_ct_flow_table_add_action_nat(struct net *net,
  					    struct nf_conn *ct,
  					    enum ip_conntrack_dir dir,
  					    struct flow_action *action)
  {
  	const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
  	struct nf_conntrack_tuple target;

  	if (!(ct->status & IPS_NAT_MASK))
  		return 0;

  	nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple);
  
  	switch (tuple->src.l3num) {
  	case NFPROTO_IPV4:
  		tcf_ct_flow_table_add_action_nat_ipv4(tuple, target,
  						      action);
  		break;
  	case NFPROTO_IPV6:
  		tcf_ct_flow_table_add_action_nat_ipv6(tuple, target,
  						      action);
  		break;
  	default:
  		return -EOPNOTSUPP;
  	}
  
  	switch (nf_ct_protonum(ct)) {
  	case IPPROTO_TCP:
  		tcf_ct_flow_table_add_action_nat_tcp(tuple, target, action);
  		break;
  	case IPPROTO_UDP:
  		tcf_ct_flow_table_add_action_nat_udp(tuple, target, action);
  		break;
  	default:
  		return -EOPNOTSUPP;
  	}
  
  	return 0;
  }
  
  static int tcf_ct_flow_table_fill_actions(struct net *net,
  					  const struct flow_offload *flow,
  					  enum flow_offload_tuple_dir tdir,
  					  struct nf_flow_rule *flow_rule)
  {
  	struct flow_action *action = &flow_rule->rule->action;
  	int num_entries = action->num_entries;
  	struct nf_conn *ct = flow->ct;
  	enum ip_conntrack_dir dir;
  	int i, err;
  
  	switch (tdir) {
  	case FLOW_OFFLOAD_DIR_ORIGINAL:
  		dir = IP_CT_DIR_ORIGINAL;
  		break;
  	case FLOW_OFFLOAD_DIR_REPLY:
  		dir = IP_CT_DIR_REPLY;
  		break;
  	default:
  		return -EOPNOTSUPP;
  	}
  
  	err = tcf_ct_flow_table_add_action_nat(net, ct, dir, action);
  	if (err)
  		goto err_nat;
  
  	tcf_ct_flow_table_add_action_meta(ct, dir, action);
  	return 0;
  
  err_nat:
  	/* Clear filled actions */
  	for (i = num_entries; i < action->num_entries; i++)
  		memset(&action->entries[i], 0, sizeof(action->entries[i]));
  	action->num_entries = num_entries;
  
  	return err;
  }

  static struct nf_flowtable_type flowtable_ct = {

  	.action		= tcf_ct_flow_table_fill_actions,

  	.owner		= THIS_MODULE,
  };
  
  static int tcf_ct_flow_table_get(struct tcf_ct_params *params)
  {
  	struct tcf_ct_flow_table *ct_ft;
  	int err = -ENOMEM;

  	mutex_lock(&zones_mutex);

  	ct_ft = rhashtable_lookup_fast(&zones_ht, &params->zone, zones_params);

  	if (ct_ft && refcount_inc_not_zero(&ct_ft->ref))
  		goto out_unlock;

  	ct_ft = kzalloc(sizeof(*ct_ft), GFP_KERNEL);

  	if (!ct_ft)
  		goto err_alloc;

  	refcount_set(&ct_ft->ref, 1);

  
  	ct_ft->zone = params->zone;
  	err = rhashtable_insert_fast(&zones_ht, &ct_ft->node, zones_params);
  	if (err)
  		goto err_insert;
  
  	ct_ft->nf_ft.type = &flowtable_ct;

  	ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD;

  	err = nf_flow_table_init(&ct_ft->nf_ft);
  	if (err)
  		goto err_init;
  
  	__module_get(THIS_MODULE);

  out_unlock:

  	params->ct_ft = ct_ft;

  	params->nf_ft = &ct_ft->nf_ft;

  	mutex_unlock(&zones_mutex);

  
  	return 0;
  
  err_init:
  	rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
  err_insert:
  	kfree(ct_ft);
  err_alloc:

  	mutex_unlock(&zones_mutex);

  	return err;
  }
  
  static void tcf_ct_flow_table_cleanup_work(struct work_struct *work)
  {
  	struct tcf_ct_flow_table *ct_ft;
  
  	ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table,
  			     rwork);
  	nf_flow_table_free(&ct_ft->nf_ft);
  	kfree(ct_ft);
  
  	module_put(THIS_MODULE);
  }
  
  static void tcf_ct_flow_table_put(struct tcf_ct_params *params)
  {
  	struct tcf_ct_flow_table *ct_ft = params->ct_ft;

  	if (refcount_dec_and_test(&params->ct_ft->ref)) {

  		rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
  		INIT_RCU_WORK(&ct_ft->rwork, tcf_ct_flow_table_cleanup_work);
  		queue_rcu_work(act_ct_wq, &ct_ft->rwork);
  	}

  }

  static void tcf_ct_flow_table_add(struct tcf_ct_flow_table *ct_ft,
  				  struct nf_conn *ct,
  				  bool tcp)
  {
  	struct flow_offload *entry;
  	int err;
  
  	if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
  		return;
  
  	entry = flow_offload_alloc(ct);
  	if (!entry) {
  		WARN_ON_ONCE(1);
  		goto err_alloc;
  	}
  
  	if (tcp) {
  		ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
  		ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
  	}
  
  	err = flow_offload_add(&ct_ft->nf_ft, entry);
  	if (err)
  		goto err_add;
  
  	return;
  
  err_add:
  	flow_offload_free(entry);
  err_alloc:
  	clear_bit(IPS_OFFLOAD_BIT, &ct->status);
  }
  
  static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
  					   struct nf_conn *ct,
  					   enum ip_conntrack_info ctinfo)
  {
  	bool tcp = false;
  
  	if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
  		return;
  
  	switch (nf_ct_protonum(ct)) {
  	case IPPROTO_TCP:
  		tcp = true;
  		if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
  			return;
  		break;
  	case IPPROTO_UDP:
  		break;
  	default:
  		return;
  	}
  
  	if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
  	    ct->status & IPS_SEQ_ADJUST)
  		return;
  
  	tcf_ct_flow_table_add(ct_ft, ct, tcp);
  }

  static bool
  tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,

  				  struct flow_offload_tuple *tuple,
  				  struct tcphdr **tcph)

  {
  	struct flow_ports *ports;
  	unsigned int thoff;
  	struct iphdr *iph;

  	if (!pskb_network_may_pull(skb, sizeof(*iph)))

  		return false;
  
  	iph = ip_hdr(skb);
  	thoff = iph->ihl * 4;
  
  	if (ip_is_fragment(iph) ||
  	    unlikely(thoff != sizeof(struct iphdr)))
  		return false;
  
  	if (iph->protocol != IPPROTO_TCP &&
  	    iph->protocol != IPPROTO_UDP)
  		return false;
  
  	if (iph->ttl <= 1)
  		return false;

  	if (!pskb_network_may_pull(skb, iph->protocol == IPPROTO_TCP ?
  					thoff + sizeof(struct tcphdr) :
  					thoff + sizeof(*ports)))

  		return false;

  	iph = ip_hdr(skb);
  	if (iph->protocol == IPPROTO_TCP)
  		*tcph = (void *)(skb_network_header(skb) + thoff);

  	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);

  	tuple->src_v4.s_addr = iph->saddr;
  	tuple->dst_v4.s_addr = iph->daddr;
  	tuple->src_port = ports->source;
  	tuple->dst_port = ports->dest;
  	tuple->l3proto = AF_INET;
  	tuple->l4proto = iph->protocol;
  
  	return true;
  }
  
  static bool
  tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,

  				  struct flow_offload_tuple *tuple,
  				  struct tcphdr **tcph)

  {
  	struct flow_ports *ports;
  	struct ipv6hdr *ip6h;
  	unsigned int thoff;

  	if (!pskb_network_may_pull(skb, sizeof(*ip6h)))

  		return false;
  
  	ip6h = ipv6_hdr(skb);
  
  	if (ip6h->nexthdr != IPPROTO_TCP &&
  	    ip6h->nexthdr != IPPROTO_UDP)
  		return false;
  
  	if (ip6h->hop_limit <= 1)
  		return false;
  
  	thoff = sizeof(*ip6h);

  	if (!pskb_network_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ?
  					thoff + sizeof(struct tcphdr) :
  					thoff + sizeof(*ports)))

  		return false;

  	ip6h = ipv6_hdr(skb);
  	if (ip6h->nexthdr == IPPROTO_TCP)
  		*tcph = (void *)(skb_network_header(skb) + thoff);

  	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);

  	tuple->src_v6 = ip6h->saddr;
  	tuple->dst_v6 = ip6h->daddr;
  	tuple->src_port = ports->source;
  	tuple->dst_port = ports->dest;
  	tuple->l3proto = AF_INET6;
  	tuple->l4proto = ip6h->nexthdr;
  
  	return true;
  }

  static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
  				     struct sk_buff *skb,
  				     u8 family)
  {
  	struct nf_flowtable *nf_ft = &p->ct_ft->nf_ft;
  	struct flow_offload_tuple_rhash *tuplehash;
  	struct flow_offload_tuple tuple = {};
  	enum ip_conntrack_info ctinfo;

  	struct tcphdr *tcph = NULL;

  	struct flow_offload *flow;
  	struct nf_conn *ct;

  	u8 dir;
  
  	/* Previously seen or loopback */
  	ct = nf_ct_get(skb, &ctinfo);
  	if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
  		return false;
  
  	switch (family) {
  	case NFPROTO_IPV4:

  		if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph))

  			return false;
  		break;
  	case NFPROTO_IPV6:

  		if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple, &tcph))

  			return false;
  		break;
  	default:
  		return false;
  	}
  
  	tuplehash = flow_offload_lookup(nf_ft, &tuple);
  	if (!tuplehash)
  		return false;
  
  	dir = tuplehash->tuple.dir;
  	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
  	ct = flow->ct;

  	if (tcph && (unlikely(tcph->fin || tcph->rst))) {
  		flow_offload_teardown(flow);
  		return false;
  	}

  	ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
  						    IP_CT_ESTABLISHED_REPLY;

  	flow_offload_refresh(nf_ft, flow);

  	nf_conntrack_get(&ct->ct_general);
  	nf_ct_set(skb, ct, ctinfo);

  	nf_ct_acct_update(ct, dir, skb->len);

  
  	return true;
  }

  static int tcf_ct_flow_tables_init(void)
  {
  	return rhashtable_init(&zones_ht, &zones_params);
  }
  
  static void tcf_ct_flow_tables_uninit(void)
  {
  	rhashtable_destroy(&zones_ht);
  }

  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(skb, true)) {

  	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, bool *defrag)

  {
  	enum ip_conntrack_info ctinfo;

  	struct qdisc_skb_cb cb;

  	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);

  	cb = *qdisc_skb_cb(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)

  			return err;

  		if (!err) {

  			*defrag = true;

  			cb.mru = IPCB(skb)->frag_max_size;
  		}

  	} 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;

  		if (!err) {

  			*defrag = true;

  			cb.mru = IP6CB(skb)->frag_max_size;
  		}

  #else
  		err = -EOPNOTSUPP;
  		goto out_free;
  #endif
  	}

  	*qdisc_skb_cb(skb) = cb;

  	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);

  	tcf_ct_flow_table_put(params);

  	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)
  {

  	__be16 proto = skb_protocol(skb, true);

  	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 (proto == 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) && proto == 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. */

  		fallthrough;

  	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 = sizeof_field(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)

  	int err;

  	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;
  	}

  	err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
  	if (err == NF_ACCEPT &&
  	    ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
  		if (maniptype == NF_NAT_MANIP_SRC)
  			maniptype = NF_NAT_MANIP_DST;
  		else
  			maniptype = NF_NAT_MANIP_SRC;
  
  		err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
  	}
  	return err;

  #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;

  	bool skip_add = false;

  	bool defrag = false;

  	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;

  	tcf_lastuse_update(&c->tcf_tm);

  	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, &defrag);

  	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) {

  		if (!commit && tcf_ct_flow_table_lookup(p, skb, family)) {
  			skip_add = true;
  			goto do_nat;
  		}

  		/* 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;
  	}

  do_nat:

  	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);

  	} else if (!skip_add) {
  		tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo);

  	}
  
  out_push:
  	skb_push_rcsum(skb, nh_ofs);
  
  out:

  	tcf_action_update_bstats(&c->common, skb);

  	if (defrag)
  		qdisc_skb_cb(skb)->pkt_len = skb->len;

  	return retval;
  
  drop:

  	tcf_action_inc_drop_qstats(&c->common);

  	return TC_ACT_SHOT;
  }
  
  static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {

  	[TCA_CT_ACTION] = { .type = NLA_U16 },

  	[TCA_CT_PARMS] = NLA_POLICY_EXACT_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] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
  	[TCA_CT_NAT_IPV6_MAX] = NLA_POLICY_EXACT_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, u32 flags,

  		       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;

  	u32 index;

  
  	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]);

  	index = parm->index;
  	err = tcf_idr_check_alloc(tn, &index, a, bind);

  	if (err < 0)
  		return err;
  
  	if (!err) {

  		err = tcf_idr_create_from_flags(tn, index, est, a,
  						&act_ct_ops, bind, flags);

  		if (err) {

  			tcf_idr_cleanup(tn, 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;

  	err = tcf_ct_flow_table_get(params);
  	if (err)
  		goto cleanup;

  	spin_lock_bh(&c->tcf_lock);
  	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);

  	params = rcu_replace_pointer(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)

  		call_rcu(&params->rcu, tcf_ct_params_free);

  
  	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, u64 packets,
  			     u64 drops, u64 lastuse, bool hw)

  {
  	struct tcf_ct *c = to_ct(a);

  	tcf_action_update_stats(a, bytes, packets, drops, hw);

  	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 = sizeof_field(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(net, &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)
  {

  	int err;
  
  	act_ct_wq = alloc_ordered_workqueue("act_ct_workqueue", 0);
  	if (!act_ct_wq)
  		return -ENOMEM;
  
  	err = tcf_ct_flow_tables_init();
  	if (err)
  		goto err_tbl_init;
  
  	err = tcf_register_action(&act_ct_ops, &ct_net_ops);
  	if (err)
  		goto err_register;
  
  	return 0;

  err_register:
  	tcf_ct_flow_tables_uninit();

  err_tbl_init:
  	destroy_workqueue(act_ct_wq);

  	return err;

  }
  
  static void __exit ct_cleanup_module(void)
  {
  	tcf_unregister_action(&act_ct_ops, &ct_net_ops);

  	tcf_ct_flow_tables_uninit();
  	destroy_workqueue(act_ct_wq);

  }
  
  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");