text: // SPDX-License-Identifier: GPL-2.0
  
  #include <linux/types.h>
  #include <linux/netfilter.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/mutex.h>
  #include <linux/vmalloc.h>
  #include <linux/stddef.h>
  #include <linux/err.h>
  #include <linux/percpu.h>
  #include <linux/notifier.h>
  #include <linux/kernel.h>
  #include <linux/netdevice.h>
  
  #include <net/netfilter/nf_conntrack.h>
  #include <net/netfilter/nf_conntrack_l4proto.h>
  #include <net/netfilter/nf_conntrack_core.h>
  #include <net/netfilter/nf_conntrack_bridge.h>
  #include <net/netfilter/nf_log.h>
  
  #include <linux/ip.h>
  #include <linux/icmp.h>
  #include <linux/sysctl.h>
  #include <net/route.h>
  #include <net/ip.h>
  
  #include <linux/netfilter_ipv4.h>
  #include <linux/netfilter_ipv6.h>
  #include <linux/netfilter_ipv6/ip6_tables.h>
  #include <net/netfilter/nf_conntrack_helper.h>
  #include <net/netfilter/nf_conntrack_zones.h>
  #include <net/netfilter/nf_conntrack_seqadj.h>
  #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  #include <net/netfilter/nf_nat_helper.h>
  #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
  #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  
  #include <linux/ipv6.h>
  #include <linux/in6.h>
  #include <net/ipv6.h>
  #include <net/inet_frag.h>
  
  static DEFINE_MUTEX(nf_ct_proto_mutex);
  
  #ifdef CONFIG_SYSCTL
  __printf(4, 5)
  void nf_l4proto_log_invalid(const struct sk_buff *skb,
  			    const struct nf_hook_state *state,
  			    u8 protonum,
  			    const char *fmt, ...)
  {
  	struct net *net = state->net;
  	struct va_format vaf;
  	va_list args;
  
  	if (net->ct.sysctl_log_invalid != protonum &&
  	    net->ct.sysctl_log_invalid != IPPROTO_RAW)
  		return;
  
  	va_start(args, fmt);
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	nf_log_packet(net, state->pf, 0, skb, state->in, state->out,
  		      NULL, "nf_ct_proto_%d: %pV ", protonum, &vaf);
  	va_end(args);
  }
  EXPORT_SYMBOL_GPL(nf_l4proto_log_invalid);
  
  __printf(4, 5)
  void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
  			       const struct nf_conn *ct,
  			       const struct nf_hook_state *state,
  			       const char *fmt, ...)
  {
  	struct va_format vaf;
  	struct net *net;
  	va_list args;
  
  	net = nf_ct_net(ct);
  	if (likely(net->ct.sysctl_log_invalid == 0))
  		return;
  
  	va_start(args, fmt);
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	nf_l4proto_log_invalid(skb, state,
  			       nf_ct_protonum(ct), "%pV", &vaf);
  	va_end(args);
  }
  EXPORT_SYMBOL_GPL(nf_ct_l4proto_log_invalid);
  #endif
  
  const struct nf_conntrack_l4proto *nf_ct_l4proto_find(u8 l4proto)
  {
  	switch (l4proto) {
  	case IPPROTO_UDP: return &nf_conntrack_l4proto_udp;
  	case IPPROTO_TCP: return &nf_conntrack_l4proto_tcp;
  	case IPPROTO_ICMP: return &nf_conntrack_l4proto_icmp;
  #ifdef CONFIG_NF_CT_PROTO_DCCP
  	case IPPROTO_DCCP: return &nf_conntrack_l4proto_dccp;
  #endif
  #ifdef CONFIG_NF_CT_PROTO_SCTP
  	case IPPROTO_SCTP: return &nf_conntrack_l4proto_sctp;
  #endif
  #ifdef CONFIG_NF_CT_PROTO_UDPLITE
  	case IPPROTO_UDPLITE: return &nf_conntrack_l4proto_udplite;
  #endif
  #ifdef CONFIG_NF_CT_PROTO_GRE
  	case IPPROTO_GRE: return &nf_conntrack_l4proto_gre;
  #endif
  #if IS_ENABLED(CONFIG_IPV6)
  	case IPPROTO_ICMPV6: return &nf_conntrack_l4proto_icmpv6;
  #endif /* CONFIG_IPV6 */
  	}
  
  	return &nf_conntrack_l4proto_generic;
  };
  EXPORT_SYMBOL_GPL(nf_ct_l4proto_find);
  
  unsigned int nf_confirm(struct sk_buff *skb, unsigned int protoff,
  			struct nf_conn *ct, enum ip_conntrack_info ctinfo)
  {
  	const struct nf_conn_help *help;
  
  	help = nfct_help(ct);
  	if (help) {
  		const struct nf_conntrack_helper *helper;
  		int ret;
  
  		/* rcu_read_lock()ed by nf_hook_thresh */
  		helper = rcu_dereference(help->helper);
  		if (helper) {
  			ret = helper->help(skb,
  					   protoff,
  					   ct, ctinfo);
  			if (ret != NF_ACCEPT)
  				return ret;
  		}
  	}
  
  	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
  	    !nf_is_loopback_packet(skb)) {
  		if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
  			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
  			return NF_DROP;
  		}
  	}
  
  	/* We've seen it coming out the other side: confirm it */
  	return nf_conntrack_confirm(skb);
  }
  EXPORT_SYMBOL_GPL(nf_confirm);
  
  static bool in_vrf_postrouting(const struct nf_hook_state *state)
  {
  #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
  	if (state->hook == NF_INET_POST_ROUTING &&
  	    netif_is_l3_master(state->out))
  		return true;
  #endif
  	return false;
  }
  
  static unsigned int ipv4_confirm(void *priv,
  				 struct sk_buff *skb,
  				 const struct nf_hook_state *state)
  {
  	enum ip_conntrack_info ctinfo;
  	struct nf_conn *ct;
  
  	ct = nf_ct_get(skb, &ctinfo);
  	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
  		return nf_conntrack_confirm(skb);
  
  	if (in_vrf_postrouting(state))
  		return NF_ACCEPT;
  
  	return nf_confirm(skb,
  			  skb_network_offset(skb) + ip_hdrlen(skb),
  			  ct, ctinfo);
  }
  
  static unsigned int ipv4_conntrack_in(void *priv,
  				      struct sk_buff *skb,
  				      const struct nf_hook_state *state)
  {
  	return nf_conntrack_in(skb, state);
  }
  
  static unsigned int ipv4_conntrack_local(void *priv,
  					 struct sk_buff *skb,
  					 const struct nf_hook_state *state)
  {
  	if (ip_is_fragment(ip_hdr(skb))) { /* IP_NODEFRAG setsockopt set */
  		enum ip_conntrack_info ctinfo;
  		struct nf_conn *tmpl;
  
  		tmpl = nf_ct_get(skb, &ctinfo);
  		if (tmpl && nf_ct_is_template(tmpl)) {
  			/* when skipping ct, clear templates to avoid fooling
  			 * later targets/matches
  			 */
  			skb->_nfct = 0;
  			nf_ct_put(tmpl);
  		}
  		return NF_ACCEPT;
  	}
  
  	return nf_conntrack_in(skb, state);
  }
  
  /* Connection tracking may drop packets, but never alters them, so
   * make it the first hook.
   */
  static const struct nf_hook_ops ipv4_conntrack_ops[] = {
  	{
  		.hook		= ipv4_conntrack_in,
  		.pf		= NFPROTO_IPV4,
  		.hooknum	= NF_INET_PRE_ROUTING,
  		.priority	= NF_IP_PRI_CONNTRACK,
  	},
  	{
  		.hook		= ipv4_conntrack_local,
  		.pf		= NFPROTO_IPV4,
  		.hooknum	= NF_INET_LOCAL_OUT,
  		.priority	= NF_IP_PRI_CONNTRACK,
  	},
  	{
  		.hook		= ipv4_confirm,
  		.pf		= NFPROTO_IPV4,
  		.hooknum	= NF_INET_POST_ROUTING,
  		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
  	},
  	{
  		.hook		= ipv4_confirm,
  		.pf		= NFPROTO_IPV4,
  		.hooknum	= NF_INET_LOCAL_IN,
  		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
  	},
  };
  
  /* Fast function for those who don't want to parse /proc (and I don't
   * blame them).
   * Reversing the socket's dst/src point of view gives us the reply
   * mapping.
   */
  static int
  getorigdst(struct sock *sk, int optval, void __user *user, int *len)
  {
  	const struct inet_sock *inet = inet_sk(sk);
  	const struct nf_conntrack_tuple_hash *h;
  	struct nf_conntrack_tuple tuple;
  
  	memset(&tuple, 0, sizeof(tuple));
  
  	lock_sock(sk);
  	tuple.src.u3.ip = inet->inet_rcv_saddr;
  	tuple.src.u.tcp.port = inet->inet_sport;
  	tuple.dst.u3.ip = inet->inet_daddr;
  	tuple.dst.u.tcp.port = inet->inet_dport;
  	tuple.src.l3num = PF_INET;
  	tuple.dst.protonum = sk->sk_protocol;
  	release_sock(sk);
  
  	/* We only do TCP and SCTP at the moment: is there a better way? */
  	if (tuple.dst.protonum != IPPROTO_TCP &&
  	    tuple.dst.protonum != IPPROTO_SCTP) {
  		pr_debug("SO_ORIGINAL_DST: Not a TCP/SCTP socket\n");
  		return -ENOPROTOOPT;
  	}
  
  	if ((unsigned int)*len < sizeof(struct sockaddr_in)) {
  		pr_debug("SO_ORIGINAL_DST: len %d not %zu\n",
  			 *len, sizeof(struct sockaddr_in));
  		return -EINVAL;
  	}
  
  	h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
  	if (h) {
  		struct sockaddr_in sin;
  		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
  
  		sin.sin_family = AF_INET;
  		sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
  			.tuple.dst.u.tcp.port;
  		sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
  			.tuple.dst.u3.ip;
  		memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
  
  		pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
  			 &sin.sin_addr.s_addr, ntohs(sin.sin_port));
  		nf_ct_put(ct);
  		if (copy_to_user(user, &sin, sizeof(sin)) != 0)
  			return -EFAULT;
  		else
  			return 0;
  	}
  	pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
  		 &tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
  		 &tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
  	return -ENOENT;
  }
  
  static struct nf_sockopt_ops so_getorigdst = {
  	.pf		= PF_INET,
  	.get_optmin	= SO_ORIGINAL_DST,
  	.get_optmax	= SO_ORIGINAL_DST + 1,
  	.get		= getorigdst,
  	.owner		= THIS_MODULE,
  };
  
  #if IS_ENABLED(CONFIG_IPV6)
  static int
  ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
  {
  	struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 };
  	const struct ipv6_pinfo *inet6 = inet6_sk(sk);
  	const struct inet_sock *inet = inet_sk(sk);
  	const struct nf_conntrack_tuple_hash *h;
  	struct sockaddr_in6 sin6;
  	struct nf_conn *ct;
  	__be32 flow_label;
  	int bound_dev_if;
  
  	lock_sock(sk);
  	tuple.src.u3.in6 = sk->sk_v6_rcv_saddr;
  	tuple.src.u.tcp.port = inet->inet_sport;
  	tuple.dst.u3.in6 = sk->sk_v6_daddr;
  	tuple.dst.u.tcp.port = inet->inet_dport;
  	tuple.dst.protonum = sk->sk_protocol;
  	bound_dev_if = sk->sk_bound_dev_if;
  	flow_label = inet6->flow_label;
  	release_sock(sk);
  
  	if (tuple.dst.protonum != IPPROTO_TCP &&
  	    tuple.dst.protonum != IPPROTO_SCTP)
  		return -ENOPROTOOPT;
  
  	if (*len < 0 || (unsigned int)*len < sizeof(sin6))
  		return -EINVAL;
  
  	h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
  	if (!h) {
  		pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
  			 &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
  			 &tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port));
  		return -ENOENT;
  	}
  
  	ct = nf_ct_tuplehash_to_ctrack(h);
  
  	sin6.sin6_family = AF_INET6;
  	sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
  	sin6.sin6_flowinfo = flow_label & IPV6_FLOWINFO_MASK;
  	memcpy(&sin6.sin6_addr,
  	       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6,
  	       sizeof(sin6.sin6_addr));
  
  	nf_ct_put(ct);
  	sin6.sin6_scope_id = ipv6_iface_scope_id(&sin6.sin6_addr, bound_dev_if);
  	return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
  }
  
  static struct nf_sockopt_ops so_getorigdst6 = {
  	.pf		= NFPROTO_IPV6,
  	.get_optmin	= IP6T_SO_ORIGINAL_DST,
  	.get_optmax	= IP6T_SO_ORIGINAL_DST + 1,
  	.get		= ipv6_getorigdst,
  	.owner		= THIS_MODULE,
  };
  
  static unsigned int ipv6_confirm(void *priv,
  				 struct sk_buff *skb,
  				 const struct nf_hook_state *state)
  {
  	struct nf_conn *ct;
  	enum ip_conntrack_info ctinfo;
  	unsigned char pnum = ipv6_hdr(skb)->nexthdr;
  	__be16 frag_off;
  	int protoff;
  
  	ct = nf_ct_get(skb, &ctinfo);
  	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
  		return nf_conntrack_confirm(skb);
  
  	if (in_vrf_postrouting(state))
  		return NF_ACCEPT;
  
  	protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
  				   &frag_off);
  	if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
  		pr_debug("proto header not found\n");
  		return nf_conntrack_confirm(skb);
  	}
  
  	return nf_confirm(skb, protoff, ct, ctinfo);
  }
  
  static unsigned int ipv6_conntrack_in(void *priv,
  				      struct sk_buff *skb,
  				      const struct nf_hook_state *state)
  {
  	return nf_conntrack_in(skb, state);
  }
  
  static unsigned int ipv6_conntrack_local(void *priv,
  					 struct sk_buff *skb,
  					 const struct nf_hook_state *state)
  {
  	return nf_conntrack_in(skb, state);
  }
  
  static const struct nf_hook_ops ipv6_conntrack_ops[] = {
  	{
  		.hook		= ipv6_conntrack_in,
  		.pf		= NFPROTO_IPV6,
  		.hooknum	= NF_INET_PRE_ROUTING,
  		.priority	= NF_IP6_PRI_CONNTRACK,
  	},
  	{
  		.hook		= ipv6_conntrack_local,
  		.pf		= NFPROTO_IPV6,
  		.hooknum	= NF_INET_LOCAL_OUT,
  		.priority	= NF_IP6_PRI_CONNTRACK,
  	},
  	{
  		.hook		= ipv6_confirm,
  		.pf		= NFPROTO_IPV6,
  		.hooknum	= NF_INET_POST_ROUTING,
  		.priority	= NF_IP6_PRI_LAST,
  	},
  	{
  		.hook		= ipv6_confirm,
  		.pf		= NFPROTO_IPV6,
  		.hooknum	= NF_INET_LOCAL_IN,
  		.priority	= NF_IP6_PRI_LAST - 1,
  	},
  };
  #endif
  
  static int nf_ct_tcp_fixup(struct nf_conn *ct, void *_nfproto)
  {
  	u8 nfproto = (unsigned long)_nfproto;
  
  	if (nf_ct_l3num(ct) != nfproto)
  		return 0;
  
  	if (nf_ct_protonum(ct) == IPPROTO_TCP &&
  	    ct->proto.tcp.state == TCP_CONNTRACK_ESTABLISHED) {
  		ct->proto.tcp.seen[0].td_maxwin = 0;
  		ct->proto.tcp.seen[1].td_maxwin = 0;
  	}
  
  	return 0;
  }
  
  static struct nf_ct_bridge_info *nf_ct_bridge_info;
  
  static int nf_ct_netns_do_get(struct net *net, u8 nfproto)
  {
  	struct nf_conntrack_net *cnet = nf_ct_pernet(net);
  	bool fixup_needed = false, retry = true;
  	int err = 0;
  retry:
  	mutex_lock(&nf_ct_proto_mutex);
  
  	switch (nfproto) {
  	case NFPROTO_IPV4:
  		cnet->users4++;
  		if (cnet->users4 > 1)
  			goto out_unlock;
  		err = nf_defrag_ipv4_enable(net);
  		if (err) {
  			cnet->users4 = 0;
  			goto out_unlock;
  		}
  
  		err = nf_register_net_hooks(net, ipv4_conntrack_ops,
  					    ARRAY_SIZE(ipv4_conntrack_ops));
  		if (err)
  			cnet->users4 = 0;
  		else
  			fixup_needed = true;
  		break;
  #if IS_ENABLED(CONFIG_IPV6)
  	case NFPROTO_IPV6:
  		cnet->users6++;
  		if (cnet->users6 > 1)
  			goto out_unlock;
  		err = nf_defrag_ipv6_enable(net);
  		if (err < 0) {
  			cnet->users6 = 0;
  			goto out_unlock;
  		}
  
  		err = nf_register_net_hooks(net, ipv6_conntrack_ops,
  					    ARRAY_SIZE(ipv6_conntrack_ops));
  		if (err)
  			cnet->users6 = 0;
  		else
  			fixup_needed = true;
  		break;
  #endif
  	case NFPROTO_BRIDGE:
  		if (!nf_ct_bridge_info) {
  			if (!retry) {
  				err = -EPROTO;
  				goto out_unlock;
  			}
  			mutex_unlock(&nf_ct_proto_mutex);
  			request_module("nf_conntrack_bridge");
  			retry = false;
  			goto retry;
  		}
  		if (!try_module_get(nf_ct_bridge_info->me)) {
  			err = -EPROTO;
  			goto out_unlock;
  		}
  		cnet->users_bridge++;
  		if (cnet->users_bridge > 1)
  			goto out_unlock;
  
  		err = nf_register_net_hooks(net, nf_ct_bridge_info->ops,
  					    nf_ct_bridge_info->ops_size);
  		if (err)
  			cnet->users_bridge = 0;
  		else
  			fixup_needed = true;
  		break;
  	default:
  		err = -EPROTO;
  		break;
  	}
   out_unlock:
  	mutex_unlock(&nf_ct_proto_mutex);
  
  	if (fixup_needed)
  		nf_ct_iterate_cleanup_net(net, nf_ct_tcp_fixup,
  					  (void *)(unsigned long)nfproto, 0, 0);
  
  	return err;
  }
  
  static void nf_ct_netns_do_put(struct net *net, u8 nfproto)
  {
  	struct nf_conntrack_net *cnet = nf_ct_pernet(net);
  
  	mutex_lock(&nf_ct_proto_mutex);
  	switch (nfproto) {
  	case NFPROTO_IPV4:
  		if (cnet->users4 && (--cnet->users4 == 0)) {
  			nf_unregister_net_hooks(net, ipv4_conntrack_ops,
  						ARRAY_SIZE(ipv4_conntrack_ops));
  			nf_defrag_ipv4_disable(net);
  		}
  		break;
  #if IS_ENABLED(CONFIG_IPV6)
  	case NFPROTO_IPV6:
  		if (cnet->users6 && (--cnet->users6 == 0)) {
  			nf_unregister_net_hooks(net, ipv6_conntrack_ops,
  						ARRAY_SIZE(ipv6_conntrack_ops));
  			nf_defrag_ipv6_disable(net);
  		}
  		break;
  #endif
  	case NFPROTO_BRIDGE:
  		if (!nf_ct_bridge_info)
  			break;
  		if (cnet->users_bridge && (--cnet->users_bridge == 0))
  			nf_unregister_net_hooks(net, nf_ct_bridge_info->ops,
  						nf_ct_bridge_info->ops_size);
  
  		module_put(nf_ct_bridge_info->me);
  		break;
  	}
  	mutex_unlock(&nf_ct_proto_mutex);
  }
  
  static int nf_ct_netns_inet_get(struct net *net)
  {
  	int err;
  
  	err = nf_ct_netns_do_get(net, NFPROTO_IPV4);
  #if IS_ENABLED(CONFIG_IPV6)
  	if (err < 0)
  		goto err1;
  	err = nf_ct_netns_do_get(net, NFPROTO_IPV6);
  	if (err < 0)
  		goto err2;
  
  	return err;
  err2:
  	nf_ct_netns_put(net, NFPROTO_IPV4);
  err1:
  #endif
  	return err;
  }
  
  int nf_ct_netns_get(struct net *net, u8 nfproto)
  {
  	int err;
  
  	switch (nfproto) {
  	case NFPROTO_INET:
  		err = nf_ct_netns_inet_get(net);
  		break;
  	case NFPROTO_BRIDGE:
  		err = nf_ct_netns_do_get(net, NFPROTO_BRIDGE);
  		if (err < 0)
  			return err;
  
  		err = nf_ct_netns_inet_get(net);
  		if (err < 0) {
  			nf_ct_netns_put(net, NFPROTO_BRIDGE);
  			return err;
  		}
  		break;
  	default:
  		err = nf_ct_netns_do_get(net, nfproto);
  		break;
  	}
  	return err;
  }
  EXPORT_SYMBOL_GPL(nf_ct_netns_get);
  
  void nf_ct_netns_put(struct net *net, uint8_t nfproto)
  {
  	switch (nfproto) {
  	case NFPROTO_BRIDGE:
  		nf_ct_netns_do_put(net, NFPROTO_BRIDGE);
  		fallthrough;
  	case NFPROTO_INET:
  		nf_ct_netns_do_put(net, NFPROTO_IPV4);
  		nf_ct_netns_do_put(net, NFPROTO_IPV6);
  		break;
  	default:
  		nf_ct_netns_do_put(net, nfproto);
  		break;
  	}
  }
  EXPORT_SYMBOL_GPL(nf_ct_netns_put);
  
  void nf_ct_bridge_register(struct nf_ct_bridge_info *info)
  {
  	WARN_ON(nf_ct_bridge_info);
  	mutex_lock(&nf_ct_proto_mutex);
  	nf_ct_bridge_info = info;
  	mutex_unlock(&nf_ct_proto_mutex);
  }
  EXPORT_SYMBOL_GPL(nf_ct_bridge_register);
  
  void nf_ct_bridge_unregister(struct nf_ct_bridge_info *info)
  {
  	WARN_ON(!nf_ct_bridge_info);
  	mutex_lock(&nf_ct_proto_mutex);
  	nf_ct_bridge_info = NULL;
  	mutex_unlock(&nf_ct_proto_mutex);
  }
  EXPORT_SYMBOL_GPL(nf_ct_bridge_unregister);
  
  int nf_conntrack_proto_init(void)
  {
  	int ret;
  
  	ret = nf_register_sockopt(&so_getorigdst);
  	if (ret < 0)
  		return ret;
  
  #if IS_ENABLED(CONFIG_IPV6)
  	ret = nf_register_sockopt(&so_getorigdst6);
  	if (ret < 0)
  		goto cleanup_sockopt;
  #endif
  
  	return ret;
  
  #if IS_ENABLED(CONFIG_IPV6)
  cleanup_sockopt:
  	nf_unregister_sockopt(&so_getorigdst);
  #endif
  	return ret;
  }
  
  void nf_conntrack_proto_fini(void)
  {
  	nf_unregister_sockopt(&so_getorigdst);
  #if IS_ENABLED(CONFIG_IPV6)
  	nf_unregister_sockopt(&so_getorigdst6);
  #endif
  }
  
  void nf_conntrack_proto_pernet_init(struct net *net)
  {
  	nf_conntrack_generic_init_net(net);
  	nf_conntrack_udp_init_net(net);
  	nf_conntrack_tcp_init_net(net);
  	nf_conntrack_icmp_init_net(net);
  #if IS_ENABLED(CONFIG_IPV6)
  	nf_conntrack_icmpv6_init_net(net);
  #endif
  #ifdef CONFIG_NF_CT_PROTO_DCCP
  	nf_conntrack_dccp_init_net(net);
  #endif
  #ifdef CONFIG_NF_CT_PROTO_SCTP
  	nf_conntrack_sctp_init_net(net);
  #endif
  #ifdef CONFIG_NF_CT_PROTO_GRE
  	nf_conntrack_gre_init_net(net);
  #endif
  }
  
  module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
  		  &nf_conntrack_htable_size, 0600);
  
  MODULE_ALIAS("ip_conntrack");
  MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
  MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
  MODULE_LICENSE("GPL");
  