text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * This is a module which is used for queueing packets and communicating with
   * userspace via nfnetlink.
   *
   * (C) 2005 by Harald Welte <laforge@netfilter.org>
   * (C) 2007 by Patrick McHardy <kaber@trash.net>
   *
   * Based on the old ipv4-only ip_queue.c:
   * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
   * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/skbuff.h>
  #include <linux/init.h>
  #include <linux/spinlock.h>
  #include <linux/slab.h>
  #include <linux/notifier.h>
  #include <linux/netdevice.h>
  #include <linux/netfilter.h>
  #include <linux/proc_fs.h>
  #include <linux/netfilter_ipv4.h>
  #include <linux/netfilter_ipv6.h>
  #include <linux/netfilter_bridge.h>
  #include <linux/netfilter/nfnetlink.h>
  #include <linux/netfilter/nfnetlink_queue.h>
  #include <linux/netfilter/nf_conntrack_common.h>
  #include <linux/list.h>
  #include <net/sock.h>
  #include <net/tcp_states.h>
  #include <net/netfilter/nf_queue.h>
  #include <net/netns/generic.h>
  
  #include <linux/atomic.h>
  
  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  #include "../bridge/br_private.h"
  #endif
  
  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  #include <net/netfilter/nf_conntrack.h>
  #endif
  
  #define NFQNL_QMAX_DEFAULT 1024
  
  /* We're using struct nlattr which has 16bit nla_len. Note that nla_len
   * includes the header length. Thus, the maximum packet length that we
   * support is 65531 bytes. We send truncated packets if the specified length
   * is larger than that.  Userspace can check for presence of NFQA_CAP_LEN
   * attribute to detect truncation.
   */
  #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN)
  
  struct nfqnl_instance {
  	struct hlist_node hlist;		/* global list of queues */
  	struct rcu_head rcu;
  
  	u32 peer_portid;
  	unsigned int queue_maxlen;
  	unsigned int copy_range;
  	unsigned int queue_dropped;
  	unsigned int queue_user_dropped;
  
  
  	u_int16_t queue_num;			/* number of this queue */
  	u_int8_t copy_mode;
  	u_int32_t flags;			/* Set using NFQA_CFG_FLAGS */
  /*
   * Following fields are dirtied for each queued packet,
   * keep them in same cache line if possible.
   */
  	spinlock_t	lock	____cacheline_aligned_in_smp;
  	unsigned int	queue_total;
  	unsigned int	id_sequence;		/* 'sequence' of pkt ids */
  	struct list_head queue_list;		/* packets in queue */
  };
  
  typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
  
  static unsigned int nfnl_queue_net_id __read_mostly;
  
  #define INSTANCE_BUCKETS	16
  struct nfnl_queue_net {
  	spinlock_t instances_lock;
  	struct hlist_head instance_table[INSTANCE_BUCKETS];
  };
  
  static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net)
  {
  	return net_generic(net, nfnl_queue_net_id);
  }
  
  static inline u_int8_t instance_hashfn(u_int16_t queue_num)
  {
  	return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
  }
  
  static struct nfqnl_instance *
  instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num)
  {
  	struct hlist_head *head;
  	struct nfqnl_instance *inst;
  
  	head = &q->instance_table[instance_hashfn(queue_num)];
  	hlist_for_each_entry_rcu(inst, head, hlist) {
  		if (inst->queue_num == queue_num)
  			return inst;
  	}
  	return NULL;
  }
  
  static struct nfqnl_instance *
  instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid)
  {
  	struct nfqnl_instance *inst;
  	unsigned int h;
  	int err;
  
  	spin_lock(&q->instances_lock);
  	if (instance_lookup(q, queue_num)) {
  		err = -EEXIST;
  		goto out_unlock;
  	}
  
  	inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
  	if (!inst) {
  		err = -ENOMEM;
  		goto out_unlock;
  	}
  
  	inst->queue_num = queue_num;
  	inst->peer_portid = portid;
  	inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
  	inst->copy_range = NFQNL_MAX_COPY_RANGE;
  	inst->copy_mode = NFQNL_COPY_NONE;
  	spin_lock_init(&inst->lock);
  	INIT_LIST_HEAD(&inst->queue_list);
  
  	if (!try_module_get(THIS_MODULE)) {
  		err = -EAGAIN;
  		goto out_free;
  	}
  
  	h = instance_hashfn(queue_num);
  	hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]);
  
  	spin_unlock(&q->instances_lock);
  
  	return inst;
  
  out_free:
  	kfree(inst);
  out_unlock:
  	spin_unlock(&q->instances_lock);
  	return ERR_PTR(err);
  }
  
  static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
  			unsigned long data);
  
  static void
  instance_destroy_rcu(struct rcu_head *head)
  {
  	struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
  						   rcu);
  
  	nfqnl_flush(inst, NULL, 0);
  	kfree(inst);
  	module_put(THIS_MODULE);
  }
  
  static void
  __instance_destroy(struct nfqnl_instance *inst)
  {
  	hlist_del_rcu(&inst->hlist);
  	call_rcu(&inst->rcu, instance_destroy_rcu);
  }
  
  static void
  instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
  {
  	spin_lock(&q->instances_lock);
  	__instance_destroy(inst);
  	spin_unlock(&q->instances_lock);
  }
  
  static inline void
  __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
  {
         list_add_tail(&entry->list, &queue->queue_list);
         queue->queue_total++;
  }
  
  static void
  __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
  {
  	list_del(&entry->list);
  	queue->queue_total--;
  }
  
  static struct nf_queue_entry *
  find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
  {
  	struct nf_queue_entry *entry = NULL, *i;
  
  	spin_lock_bh(&queue->lock);
  
  	list_for_each_entry(i, &queue->queue_list, list) {
  		if (i->id == id) {
  			entry = i;
  			break;
  		}
  	}
  
  	if (entry)
  		__dequeue_entry(queue, entry);
  
  	spin_unlock_bh(&queue->lock);
  
  	return entry;
  }
  
  static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict)
  {
  	struct nf_ct_hook *ct_hook;
  	int err;
  
  	if (verdict == NF_ACCEPT ||
  	    verdict == NF_REPEAT ||
  	    verdict == NF_STOP) {
  		rcu_read_lock();
  		ct_hook = rcu_dereference(nf_ct_hook);
  		if (ct_hook) {
  			err = ct_hook->update(entry->state.net, entry->skb);
  			if (err < 0)
  				verdict = NF_DROP;
  		}
  		rcu_read_unlock();
  	}
  	nf_reinject(entry, verdict);
  }
  
  static void
  nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
  {
  	struct nf_queue_entry *entry, *next;
  
  	spin_lock_bh(&queue->lock);
  	list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
  		if (!cmpfn || cmpfn(entry, data)) {
  			list_del(&entry->list);
  			queue->queue_total--;
  			nfqnl_reinject(entry, NF_DROP);
  		}
  	}
  	spin_unlock_bh(&queue->lock);
  }
  
  static int
  nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
  		      bool csum_verify)
  {
  	__u32 flags = 0;
  
  	if (packet->ip_summed == CHECKSUM_PARTIAL)
  		flags = NFQA_SKB_CSUMNOTREADY;
  	else if (csum_verify)
  		flags = NFQA_SKB_CSUM_NOTVERIFIED;
  
  	if (skb_is_gso(packet))
  		flags |= NFQA_SKB_GSO;
  
  	return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
  }
  
  static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
  {
  	const struct cred *cred;
  
  	if (!sk_fullsock(sk))
  		return 0;
  
  	read_lock_bh(&sk->sk_callback_lock);
  	if (sk->sk_socket && sk->sk_socket->file) {
  		cred = sk->sk_socket->file->f_cred;
  		if (nla_put_be32(skb, NFQA_UID,
  		    htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
  			goto nla_put_failure;
  		if (nla_put_be32(skb, NFQA_GID,
  		    htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
  			goto nla_put_failure;
  	}
  	read_unlock_bh(&sk->sk_callback_lock);
  	return 0;
  
  nla_put_failure:
  	read_unlock_bh(&sk->sk_callback_lock);
  	return -1;
  }
  
  static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
  {
  	u32 seclen = 0;
  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
  	if (!skb || !sk_fullsock(skb->sk))
  		return 0;
  
  	read_lock_bh(&skb->sk->sk_callback_lock);
  
  	if (skb->secmark)
  		security_secid_to_secctx(skb->secmark, secdata, &seclen);
  
  	read_unlock_bh(&skb->sk->sk_callback_lock);
  #endif
  	return seclen;
  }
  
  static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
  {
  	struct sk_buff *entskb = entry->skb;
  	u32 nlalen = 0;
  
  	if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
  		return 0;
  
  	if (skb_vlan_tag_present(entskb))
  		nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
  					 nla_total_size(sizeof(__be16)));
  
  	if (entskb->network_header > entskb->mac_header)
  		nlalen += nla_total_size((entskb->network_header -
  					  entskb->mac_header));
  
  	return nlalen;
  }
  
  static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
  {
  	struct sk_buff *entskb = entry->skb;
  
  	if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
  		return 0;
  
  	if (skb_vlan_tag_present(entskb)) {
  		struct nlattr *nest;
  
  		nest = nla_nest_start(skb, NFQA_VLAN);
  		if (!nest)
  			goto nla_put_failure;
  
  		if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
  		    nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
  			goto nla_put_failure;
  
  		nla_nest_end(skb, nest);
  	}
  
  	if (entskb->mac_header < entskb->network_header) {
  		int len = (int)(entskb->network_header - entskb->mac_header);
  
  		if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
  			goto nla_put_failure;
  	}
  
  	return 0;
  
  nla_put_failure:
  	return -1;
  }
  
  static struct sk_buff *
  nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
  			   struct nf_queue_entry *entry,
  			   __be32 **packet_id_ptr)
  {
  	size_t size;
  	size_t data_len = 0, cap_len = 0;
  	unsigned int hlen = 0;
  	struct sk_buff *skb;
  	struct nlattr *nla;
  	struct nfqnl_msg_packet_hdr *pmsg;
  	struct nlmsghdr *nlh;
  	struct nfgenmsg *nfmsg;
  	struct sk_buff *entskb = entry->skb;
  	struct net_device *indev;
  	struct net_device *outdev;
  	struct nf_conn *ct = NULL;
  	enum ip_conntrack_info ctinfo;
  	struct nfnl_ct_hook *nfnl_ct;
  	bool csum_verify;
  	char *secdata = NULL;
  	u32 seclen = 0;
  
  	size = nlmsg_total_size(sizeof(struct nfgenmsg))
  		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
  		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
  		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
  		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
  #endif
  		+ nla_total_size(sizeof(u_int32_t))	/* mark */
  		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
  		+ nla_total_size(sizeof(u_int32_t))	/* skbinfo */
  		+ nla_total_size(sizeof(u_int32_t));	/* cap_len */
  
  	if (entskb->tstamp)
  		size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
  
  	size += nfqnl_get_bridge_size(entry);
  
  	if (entry->state.hook <= NF_INET_FORWARD ||
  	   (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
  		csum_verify = !skb_csum_unnecessary(entskb);
  	else
  		csum_verify = false;
  
  	outdev = entry->state.out;
  
  	switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
  	case NFQNL_COPY_META:
  	case NFQNL_COPY_NONE:
  		break;
  
  	case NFQNL_COPY_PACKET:
  		if (!(queue->flags & NFQA_CFG_F_GSO) &&
  		    entskb->ip_summed == CHECKSUM_PARTIAL &&
  		    skb_checksum_help(entskb))
  			return NULL;
  
  		data_len = READ_ONCE(queue->copy_range);
  		if (data_len > entskb->len)
  			data_len = entskb->len;
  
  		hlen = skb_zerocopy_headlen(entskb);
  		hlen = min_t(unsigned int, hlen, data_len);
  		size += sizeof(struct nlattr) + hlen;
  		cap_len = entskb->len;
  		break;
  	}
  
  	nfnl_ct = rcu_dereference(nfnl_ct_hook);
  
  	if (queue->flags & NFQA_CFG_F_CONNTRACK) {
  		if (nfnl_ct != NULL) {
  			ct = nfnl_ct->get_ct(entskb, &ctinfo);
  			if (ct != NULL)
  				size += nfnl_ct->build_size(ct);
  		}
  	}
  
  	if (queue->flags & NFQA_CFG_F_UID_GID) {
  		size += (nla_total_size(sizeof(u_int32_t))	/* uid */
  			+ nla_total_size(sizeof(u_int32_t)));	/* gid */
  	}
  
  	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
  		seclen = nfqnl_get_sk_secctx(entskb, &secdata);
  		if (seclen)
  			size += nla_total_size(seclen);
  	}
  
  	skb = alloc_skb(size, GFP_ATOMIC);
  	if (!skb) {
  		skb_tx_error(entskb);
  		goto nlmsg_failure;
  	}
  
  	nlh = nlmsg_put(skb, 0, 0,
  			nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
  			sizeof(struct nfgenmsg), 0);
  	if (!nlh) {
  		skb_tx_error(entskb);
  		kfree_skb(skb);
  		goto nlmsg_failure;
  	}
  	nfmsg = nlmsg_data(nlh);
  	nfmsg->nfgen_family = entry->state.pf;
  	nfmsg->version = NFNETLINK_V0;
  	nfmsg->res_id = htons(queue->queue_num);
  
  	nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
  	pmsg = nla_data(nla);
  	pmsg->hw_protocol	= entskb->protocol;
  	pmsg->hook		= entry->state.hook;
  	*packet_id_ptr		= &pmsg->packet_id;
  
  	indev = entry->state.in;
  	if (indev) {
  #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  		if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
  			goto nla_put_failure;
  #else
  		if (entry->state.pf == PF_BRIDGE) {
  			/* Case 1: indev is physical input device, we need to
  			 * look for bridge group (when called from
  			 * netfilter_bridge) */
  			if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
  					 htonl(indev->ifindex)) ||
  			/* this is the bridge group "brX" */
  			/* rcu_read_lock()ed by __nf_queue */
  			    nla_put_be32(skb, NFQA_IFINDEX_INDEV,
  					 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
  				goto nla_put_failure;
  		} else {
  			int physinif;
  
  			/* Case 2: indev is bridge group, we need to look for
  			 * physical device (when called from ipv4) */
  			if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
  					 htonl(indev->ifindex)))
  				goto nla_put_failure;
  
  			physinif = nf_bridge_get_physinif(entskb);
  			if (physinif &&
  			    nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
  					 htonl(physinif)))
  				goto nla_put_failure;
  		}
  #endif
  	}
  
  	if (outdev) {
  #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  		if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
  			goto nla_put_failure;
  #else
  		if (entry->state.pf == PF_BRIDGE) {
  			/* Case 1: outdev is physical output device, we need to
  			 * look for bridge group (when called from
  			 * netfilter_bridge) */
  			if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
  					 htonl(outdev->ifindex)) ||
  			/* this is the bridge group "brX" */
  			/* rcu_read_lock()ed by __nf_queue */
  			    nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
  					 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
  				goto nla_put_failure;
  		} else {
  			int physoutif;
  
  			/* Case 2: outdev is bridge group, we need to look for
  			 * physical output device (when called from ipv4) */
  			if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
  					 htonl(outdev->ifindex)))
  				goto nla_put_failure;
  
  			physoutif = nf_bridge_get_physoutif(entskb);
  			if (physoutif &&
  			    nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
  					 htonl(physoutif)))
  				goto nla_put_failure;
  		}
  #endif
  	}
  
  	if (entskb->mark &&
  	    nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
  		goto nla_put_failure;
  
  	if (indev && entskb->dev &&
  	    entskb->mac_header != entskb->network_header) {
  		struct nfqnl_msg_packet_hw phw;
  		int len;
  
  		memset(&phw, 0, sizeof(phw));
  		len = dev_parse_header(entskb, phw.hw_addr);
  		if (len) {
  			phw.hw_addrlen = htons(len);
  			if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
  				goto nla_put_failure;
  		}
  	}
  
  	if (nfqnl_put_bridge(entry, skb) < 0)
  		goto nla_put_failure;
  
  	if (entry->state.hook <= NF_INET_FORWARD && entskb->tstamp) {
  		struct nfqnl_msg_packet_timestamp ts;
  		struct timespec64 kts = ktime_to_timespec64(entskb->tstamp);
  
  		ts.sec = cpu_to_be64(kts.tv_sec);
  		ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
  
  		if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
  			goto nla_put_failure;
  	}
  
  	if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
  	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
  		goto nla_put_failure;
  
  	if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
  		goto nla_put_failure;
  
  	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
  		goto nla_put_failure;
  
  	if (cap_len > data_len &&
  	    nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
  		goto nla_put_failure;
  
  	if (nfqnl_put_packet_info(skb, entskb, csum_verify))
  		goto nla_put_failure;
  
  	if (data_len) {
  		struct nlattr *nla;
  
  		if (skb_tailroom(skb) < sizeof(*nla) + hlen)
  			goto nla_put_failure;
  
  		nla = skb_put(skb, sizeof(*nla));
  		nla->nla_type = NFQA_PAYLOAD;
  		nla->nla_len = nla_attr_size(data_len);
  
  		if (skb_zerocopy(skb, entskb, data_len, hlen))
  			goto nla_put_failure;
  	}
  
  	nlh->nlmsg_len = skb->len;
  	if (seclen)
  		security_release_secctx(secdata, seclen);
  	return skb;
  
  nla_put_failure:
  	skb_tx_error(entskb);
  	kfree_skb(skb);
  	net_err_ratelimited("nf_queue: error creating packet message\n");
  nlmsg_failure:
  	if (seclen)
  		security_release_secctx(secdata, seclen);
  	return NULL;
  }
  
  static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry)
  {
  #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  	static const unsigned long flags = IPS_CONFIRMED | IPS_DYING;
  	const struct nf_conn *ct = (void *)skb_nfct(entry->skb);
  
  	if (ct && ((ct->status & flags) == IPS_DYING))
  		return true;
  #endif
  	return false;
  }
  
  static int
  __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
  			struct nf_queue_entry *entry)
  {
  	struct sk_buff *nskb;
  	int err = -ENOBUFS;
  	__be32 *packet_id_ptr;
  	int failopen = 0;
  
  	nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
  	if (nskb == NULL) {
  		err = -ENOMEM;
  		goto err_out;
  	}
  	spin_lock_bh(&queue->lock);
  
  	if (nf_ct_drop_unconfirmed(entry))
  		goto err_out_free_nskb;
  
  	if (queue->queue_total >= queue->queue_maxlen) {
  		if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
  			failopen = 1;
  			err = 0;
  		} else {
  			queue->queue_dropped++;
  			net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
  					     queue->queue_total);
  		}
  		goto err_out_free_nskb;
  	}
  	entry->id = ++queue->id_sequence;
  	*packet_id_ptr = htonl(entry->id);
  
  	/* nfnetlink_unicast will either free the nskb or add it to a socket */
  	err = nfnetlink_unicast(nskb, net, queue->peer_portid);
  	if (err < 0) {
  		if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
  			failopen = 1;
  			err = 0;
  		} else {
  			queue->queue_user_dropped++;
  		}
  		goto err_out_unlock;
  	}
  
  	__enqueue_entry(queue, entry);
  
  	spin_unlock_bh(&queue->lock);
  	return 0;
  
  err_out_free_nskb:
  	kfree_skb(nskb);
  err_out_unlock:
  	spin_unlock_bh(&queue->lock);
  	if (failopen)
  		nfqnl_reinject(entry, NF_ACCEPT);
  err_out:
  	return err;
  }
  
  static struct nf_queue_entry *
  nf_queue_entry_dup(struct nf_queue_entry *e)
  {
  	struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
  	if (entry)
  		nf_queue_entry_get_refs(entry);
  	return entry;
  }
  
  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  /* When called from bridge netfilter, skb->data must point to MAC header
   * before calling skb_gso_segment(). Else, original MAC header is lost
   * and segmented skbs will be sent to wrong destination.
   */
  static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
  {
  	if (nf_bridge_info_get(skb))
  		__skb_push(skb, skb->network_header - skb->mac_header);
  }
  
  static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
  {
  	if (nf_bridge_info_get(skb))
  		__skb_pull(skb, skb->network_header - skb->mac_header);
  }
  #else
  #define nf_bridge_adjust_skb_data(s) do {} while (0)
  #define nf_bridge_adjust_segmented_data(s) do {} while (0)
  #endif
  
  static int
  __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
  			   struct sk_buff *skb, struct nf_queue_entry *entry)
  {
  	int ret = -ENOMEM;
  	struct nf_queue_entry *entry_seg;
  
  	nf_bridge_adjust_segmented_data(skb);
  
  	if (skb->next == NULL) { /* last packet, no need to copy entry */
  		struct sk_buff *gso_skb = entry->skb;
  		entry->skb = skb;
  		ret = __nfqnl_enqueue_packet(net, queue, entry);
  		if (ret)
  			entry->skb = gso_skb;
  		return ret;
  	}
  
  	skb_mark_not_on_list(skb);
  
  	entry_seg = nf_queue_entry_dup(entry);
  	if (entry_seg) {
  		entry_seg->skb = skb;
  		ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
  		if (ret)
  			nf_queue_entry_free(entry_seg);
  	}
  	return ret;
  }
  
  static int
  nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
  {
  	unsigned int queued;
  	struct nfqnl_instance *queue;
  	struct sk_buff *skb, *segs, *nskb;
  	int err = -ENOBUFS;
  	struct net *net = entry->state.net;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  
  	/* rcu_read_lock()ed by nf_hook_thresh */
  	queue = instance_lookup(q, queuenum);
  	if (!queue)
  		return -ESRCH;
  
  	if (queue->copy_mode == NFQNL_COPY_NONE)
  		return -EINVAL;
  
  	skb = entry->skb;
  
  	switch (entry->state.pf) {
  	case NFPROTO_IPV4:
  		skb->protocol = htons(ETH_P_IP);
  		break;
  	case NFPROTO_IPV6:
  		skb->protocol = htons(ETH_P_IPV6);
  		break;
  	}
  
  	if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb))
  		return __nfqnl_enqueue_packet(net, queue, entry);
  
  	nf_bridge_adjust_skb_data(skb);
  	segs = skb_gso_segment(skb, 0);
  	/* Does not use PTR_ERR to limit the number of error codes that can be
  	 * returned by nf_queue.  For instance, callers rely on -ESRCH to
  	 * mean 'ignore this hook'.
  	 */
  	if (IS_ERR_OR_NULL(segs))
  		goto out_err;
  	queued = 0;
  	err = 0;
  	skb_list_walk_safe(segs, segs, nskb) {
  		if (err == 0)
  			err = __nfqnl_enqueue_packet_gso(net, queue,
  							segs, entry);
  		if (err == 0)
  			queued++;
  		else
  			kfree_skb(segs);
  	}
  
  	if (queued) {
  		if (err) /* some segments are already queued */
  			nf_queue_entry_free(entry);
  		kfree_skb(skb);
  		return 0;
  	}
   out_err:
  	nf_bridge_adjust_segmented_data(skb);
  	return err;
  }
  
  static int
  nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
  {
  	struct sk_buff *nskb;
  
  	if (diff < 0) {
  		if (pskb_trim(e->skb, data_len))
  			return -ENOMEM;
  	} else if (diff > 0) {
  		if (data_len > 0xFFFF)
  			return -EINVAL;
  		if (diff > skb_tailroom(e->skb)) {
  			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
  					       diff, GFP_ATOMIC);
  			if (!nskb)
  				return -ENOMEM;
  			kfree_skb(e->skb);
  			e->skb = nskb;
  		}
  		skb_put(e->skb, diff);
  	}
  	if (skb_ensure_writable(e->skb, data_len))
  		return -ENOMEM;
  	skb_copy_to_linear_data(e->skb, data, data_len);
  	e->skb->ip_summed = CHECKSUM_NONE;
  	return 0;
  }
  
  static int
  nfqnl_set_mode(struct nfqnl_instance *queue,
  	       unsigned char mode, unsigned int range)
  {
  	int status = 0;
  
  	spin_lock_bh(&queue->lock);
  	switch (mode) {
  	case NFQNL_COPY_NONE:
  	case NFQNL_COPY_META:
  		queue->copy_mode = mode;
  		queue->copy_range = 0;
  		break;
  
  	case NFQNL_COPY_PACKET:
  		queue->copy_mode = mode;
  		if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
  			queue->copy_range = NFQNL_MAX_COPY_RANGE;
  		else
  			queue->copy_range = range;
  		break;
  
  	default:
  		status = -EINVAL;
  
  	}
  	spin_unlock_bh(&queue->lock);
  
  	return status;
  }
  
  static int
  dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
  {
  #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  	int physinif, physoutif;
  
  	physinif = nf_bridge_get_physinif(entry->skb);
  	physoutif = nf_bridge_get_physoutif(entry->skb);
  
  	if (physinif == ifindex || physoutif == ifindex)
  		return 1;
  #endif
  	if (entry->state.in)
  		if (entry->state.in->ifindex == ifindex)
  			return 1;
  	if (entry->state.out)
  		if (entry->state.out->ifindex == ifindex)
  			return 1;
  
  	return 0;
  }
  
  /* drop all packets with either indev or outdev == ifindex from all queue
   * instances */
  static void
  nfqnl_dev_drop(struct net *net, int ifindex)
  {
  	int i;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  
  	rcu_read_lock();
  
  	for (i = 0; i < INSTANCE_BUCKETS; i++) {
  		struct nfqnl_instance *inst;
  		struct hlist_head *head = &q->instance_table[i];
  
  		hlist_for_each_entry_rcu(inst, head, hlist)
  			nfqnl_flush(inst, dev_cmp, ifindex);
  	}
  
  	rcu_read_unlock();
  }
  
  static int
  nfqnl_rcv_dev_event(struct notifier_block *this,
  		    unsigned long event, void *ptr)
  {
  	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  
  	/* Drop any packets associated with the downed device */
  	if (event == NETDEV_DOWN)
  		nfqnl_dev_drop(dev_net(dev), dev->ifindex);
  	return NOTIFY_DONE;
  }
  
  static struct notifier_block nfqnl_dev_notifier = {
  	.notifier_call	= nfqnl_rcv_dev_event,
  };
  
  static void nfqnl_nf_hook_drop(struct net *net)
  {
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  	int i;
  
  	for (i = 0; i < INSTANCE_BUCKETS; i++) {
  		struct nfqnl_instance *inst;
  		struct hlist_head *head = &q->instance_table[i];
  
  		hlist_for_each_entry_rcu(inst, head, hlist)
  			nfqnl_flush(inst, NULL, 0);
  	}
  }
  
  static int
  nfqnl_rcv_nl_event(struct notifier_block *this,
  		   unsigned long event, void *ptr)
  {
  	struct netlink_notify *n = ptr;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
  
  	if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
  		int i;
  
  		/* destroy all instances for this portid */
  		spin_lock(&q->instances_lock);
  		for (i = 0; i < INSTANCE_BUCKETS; i++) {
  			struct hlist_node *t2;
  			struct nfqnl_instance *inst;
  			struct hlist_head *head = &q->instance_table[i];
  
  			hlist_for_each_entry_safe(inst, t2, head, hlist) {
  				if (n->portid == inst->peer_portid)
  					__instance_destroy(inst);
  			}
  		}
  		spin_unlock(&q->instances_lock);
  	}
  	return NOTIFY_DONE;
  }
  
  static struct notifier_block nfqnl_rtnl_notifier = {
  	.notifier_call	= nfqnl_rcv_nl_event,
  };
  
  static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
  	[NFQA_VLAN_TCI]		= { .type = NLA_U16},
  	[NFQA_VLAN_PROTO]	= { .type = NLA_U16},
  };
  
  static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
  	[NFQA_VERDICT_HDR]	= { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
  	[NFQA_MARK]		= { .type = NLA_U32 },
  	[NFQA_PAYLOAD]		= { .type = NLA_UNSPEC },
  	[NFQA_CT]		= { .type = NLA_UNSPEC },
  	[NFQA_EXP]		= { .type = NLA_UNSPEC },
  	[NFQA_VLAN]		= { .type = NLA_NESTED },
  };
  
  static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
  	[NFQA_VERDICT_HDR]	= { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
  	[NFQA_MARK]		= { .type = NLA_U32 },
  };
  
  static struct nfqnl_instance *
  verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
  {
  	struct nfqnl_instance *queue;
  
  	queue = instance_lookup(q, queue_num);
  	if (!queue)
  		return ERR_PTR(-ENODEV);
  
  	if (queue->peer_portid != nlportid)
  		return ERR_PTR(-EPERM);
  
  	return queue;
  }
  
  static struct nfqnl_msg_verdict_hdr*
  verdicthdr_get(const struct nlattr * const nfqa[])
  {
  	struct nfqnl_msg_verdict_hdr *vhdr;
  	unsigned int verdict;
  
  	if (!nfqa[NFQA_VERDICT_HDR])
  		return NULL;
  
  	vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
  	verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
  	if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
  		return NULL;
  	return vhdr;
  }
  
  static int nfq_id_after(unsigned int id, unsigned int max)
  {
  	return (int)(id - max) > 0;
  }
  
  static int nfqnl_recv_verdict_batch(struct net *net, struct sock *ctnl,
  				    struct sk_buff *skb,
  				    const struct nlmsghdr *nlh,
  			            const struct nlattr * const nfqa[],
  				    struct netlink_ext_ack *extack)
  {
  	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
  	struct nf_queue_entry *entry, *tmp;
  	unsigned int verdict, maxid;
  	struct nfqnl_msg_verdict_hdr *vhdr;
  	struct nfqnl_instance *queue;
  	LIST_HEAD(batch_list);
  	u16 queue_num = ntohs(nfmsg->res_id);
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  
  	queue = verdict_instance_lookup(q, queue_num,
  					NETLINK_CB(skb).portid);
  	if (IS_ERR(queue))
  		return PTR_ERR(queue);
  
  	vhdr = verdicthdr_get(nfqa);
  	if (!vhdr)
  		return -EINVAL;
  
  	verdict = ntohl(vhdr->verdict);
  	maxid = ntohl(vhdr->id);
  
  	spin_lock_bh(&queue->lock);
  
  	list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
  		if (nfq_id_after(entry->id, maxid))
  			break;
  		__dequeue_entry(queue, entry);
  		list_add_tail(&entry->list, &batch_list);
  	}
  
  	spin_unlock_bh(&queue->lock);
  
  	if (list_empty(&batch_list))
  		return -ENOENT;
  
  	list_for_each_entry_safe(entry, tmp, &batch_list, list) {
  		if (nfqa[NFQA_MARK])
  			entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
  
  		nfqnl_reinject(entry, verdict);
  	}
  	return 0;
  }
  
  static struct nf_conn *nfqnl_ct_parse(struct nfnl_ct_hook *nfnl_ct,
  				      const struct nlmsghdr *nlh,
  				      const struct nlattr * const nfqa[],
  				      struct nf_queue_entry *entry,
  				      enum ip_conntrack_info *ctinfo)
  {
  	struct nf_conn *ct;
  
  	ct = nfnl_ct->get_ct(entry->skb, ctinfo);
  	if (ct == NULL)
  		return NULL;
  
  	if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
  		return NULL;
  
  	if (nfqa[NFQA_EXP])
  		nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
  				      NETLINK_CB(entry->skb).portid,
  				      nlmsg_report(nlh));
  	return ct;
  }
  
  static int nfqa_parse_bridge(struct nf_queue_entry *entry,
  			     const struct nlattr * const nfqa[])
  {
  	if (nfqa[NFQA_VLAN]) {
  		struct nlattr *tb[NFQA_VLAN_MAX + 1];
  		int err;
  
  		err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
  						  nfqa[NFQA_VLAN],
  						  nfqa_vlan_policy, NULL);
  		if (err < 0)
  			return err;
  
  		if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
  			return -EINVAL;
  
  		__vlan_hwaccel_put_tag(entry->skb,
  			nla_get_be16(tb[NFQA_VLAN_PROTO]),
  			ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
  	}
  
  	if (nfqa[NFQA_L2HDR]) {
  		int mac_header_len = entry->skb->network_header -
  			entry->skb->mac_header;
  
  		if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
  			return -EINVAL;
  		else if (mac_header_len > 0)
  			memcpy(skb_mac_header(entry->skb),
  			       nla_data(nfqa[NFQA_L2HDR]),
  			       mac_header_len);
  	}
  
  	return 0;
  }
  
  static int nfqnl_recv_verdict(struct net *net, struct sock *ctnl,
  			      struct sk_buff *skb,
  			      const struct nlmsghdr *nlh,
  			      const struct nlattr * const nfqa[],
  			      struct netlink_ext_ack *extack)
  {
  	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
  	u_int16_t queue_num = ntohs(nfmsg->res_id);
  	struct nfqnl_msg_verdict_hdr *vhdr;
  	struct nfqnl_instance *queue;
  	unsigned int verdict;
  	struct nf_queue_entry *entry;
  	enum ip_conntrack_info ctinfo;
  	struct nfnl_ct_hook *nfnl_ct;
  	struct nf_conn *ct = NULL;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  	int err;
  
  	queue = verdict_instance_lookup(q, queue_num,
  					NETLINK_CB(skb).portid);
  	if (IS_ERR(queue))
  		return PTR_ERR(queue);
  
  	vhdr = verdicthdr_get(nfqa);
  	if (!vhdr)
  		return -EINVAL;
  
  	verdict = ntohl(vhdr->verdict);
  
  	entry = find_dequeue_entry(queue, ntohl(vhdr->id));
  	if (entry == NULL)
  		return -ENOENT;
  
  	/* rcu lock already held from nfnl->call_rcu. */
  	nfnl_ct = rcu_dereference(nfnl_ct_hook);
  
  	if (nfqa[NFQA_CT]) {
  		if (nfnl_ct != NULL)
  			ct = nfqnl_ct_parse(nfnl_ct, nlh, nfqa, entry, &ctinfo);
  	}
  
  	if (entry->state.pf == PF_BRIDGE) {
  		err = nfqa_parse_bridge(entry, nfqa);
  		if (err < 0)
  			return err;
  	}
  
  	if (nfqa[NFQA_PAYLOAD]) {
  		u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
  		int diff = payload_len - entry->skb->len;
  
  		if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
  				 payload_len, entry, diff) < 0)
  			verdict = NF_DROP;
  
  		if (ct && diff)
  			nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
  	}
  
  	if (nfqa[NFQA_MARK])
  		entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
  
  	nfqnl_reinject(entry, verdict);
  	return 0;
  }
  
  static int nfqnl_recv_unsupp(struct net *net, struct sock *ctnl,
  			     struct sk_buff *skb, const struct nlmsghdr *nlh,
  			     const struct nlattr * const nfqa[],
  			     struct netlink_ext_ack *extack)
  {
  	return -ENOTSUPP;
  }
  
  static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
  	[NFQA_CFG_CMD]		= { .len = sizeof(struct nfqnl_msg_config_cmd) },
  	[NFQA_CFG_PARAMS]	= { .len = sizeof(struct nfqnl_msg_config_params) },
  	[NFQA_CFG_QUEUE_MAXLEN]	= { .type = NLA_U32 },
  	[NFQA_CFG_MASK]		= { .type = NLA_U32 },
  	[NFQA_CFG_FLAGS]	= { .type = NLA_U32 },
  };
  
  static const struct nf_queue_handler nfqh = {
  	.outfn		= nfqnl_enqueue_packet,
  	.nf_hook_drop	= nfqnl_nf_hook_drop,
  };
  
  static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
  			     struct sk_buff *skb, const struct nlmsghdr *nlh,
  			     const struct nlattr * const nfqa[],
  			     struct netlink_ext_ack *extack)
  {
  	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
  	u_int16_t queue_num = ntohs(nfmsg->res_id);
  	struct nfqnl_instance *queue;
  	struct nfqnl_msg_config_cmd *cmd = NULL;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  	__u32 flags = 0, mask = 0;
  	int ret = 0;
  
  	if (nfqa[NFQA_CFG_CMD]) {
  		cmd = nla_data(nfqa[NFQA_CFG_CMD]);
  
  		/* Obsolete commands without queue context */
  		switch (cmd->command) {
  		case NFQNL_CFG_CMD_PF_BIND: return 0;
  		case NFQNL_CFG_CMD_PF_UNBIND: return 0;
  		}
  	}
  
  	/* Check if we support these flags in first place, dependencies should
  	 * be there too not to break atomicity.
  	 */
  	if (nfqa[NFQA_CFG_FLAGS]) {
  		if (!nfqa[NFQA_CFG_MASK]) {
  			/* A mask is needed to specify which flags are being
  			 * changed.
  			 */
  			return -EINVAL;
  		}
  
  		flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
  		mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
  
  		if (flags >= NFQA_CFG_F_MAX)
  			return -EOPNOTSUPP;
  
  #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
  		if (flags & mask & NFQA_CFG_F_SECCTX)
  			return -EOPNOTSUPP;
  #endif
  		if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
  		    !rcu_access_pointer(nfnl_ct_hook)) {
  #ifdef CONFIG_MODULES
  			nfnl_unlock(NFNL_SUBSYS_QUEUE);
  			request_module("ip_conntrack_netlink");
  			nfnl_lock(NFNL_SUBSYS_QUEUE);
  			if (rcu_access_pointer(nfnl_ct_hook))
  				return -EAGAIN;
  #endif
  			return -EOPNOTSUPP;
  		}
  	}
  
  	rcu_read_lock();
  	queue = instance_lookup(q, queue_num);
  	if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
  		ret = -EPERM;
  		goto err_out_unlock;
  	}
  
  	if (cmd != NULL) {
  		switch (cmd->command) {
  		case NFQNL_CFG_CMD_BIND:
  			if (queue) {
  				ret = -EBUSY;
  				goto err_out_unlock;
  			}
  			queue = instance_create(q, queue_num,
  						NETLINK_CB(skb).portid);
  			if (IS_ERR(queue)) {
  				ret = PTR_ERR(queue);
  				goto err_out_unlock;
  			}
  			break;
  		case NFQNL_CFG_CMD_UNBIND:
  			if (!queue) {
  				ret = -ENODEV;
  				goto err_out_unlock;
  			}
  			instance_destroy(q, queue);
  			goto err_out_unlock;
  		case NFQNL_CFG_CMD_PF_BIND:
  		case NFQNL_CFG_CMD_PF_UNBIND:
  			break;
  		default:
  			ret = -ENOTSUPP;
  			goto err_out_unlock;
  		}
  	}
  
  	if (!queue) {
  		ret = -ENODEV;
  		goto err_out_unlock;
  	}
  
  	if (nfqa[NFQA_CFG_PARAMS]) {
  		struct nfqnl_msg_config_params *params =
  			nla_data(nfqa[NFQA_CFG_PARAMS]);
  
  		nfqnl_set_mode(queue, params->copy_mode,
  				ntohl(params->copy_range));
  	}
  
  	if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
  		__be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
  
  		spin_lock_bh(&queue->lock);
  		queue->queue_maxlen = ntohl(*queue_maxlen);
  		spin_unlock_bh(&queue->lock);
  	}
  
  	if (nfqa[NFQA_CFG_FLAGS]) {
  		spin_lock_bh(&queue->lock);
  		queue->flags &= ~mask;
  		queue->flags |= flags & mask;
  		spin_unlock_bh(&queue->lock);
  	}
  
  err_out_unlock:
  	rcu_read_unlock();
  	return ret;
  }
  
  static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
  	[NFQNL_MSG_PACKET]	= { .call_rcu = nfqnl_recv_unsupp,
  				    .attr_count = NFQA_MAX, },
  	[NFQNL_MSG_VERDICT]	= { .call_rcu = nfqnl_recv_verdict,
  				    .attr_count = NFQA_MAX,
  				    .policy = nfqa_verdict_policy },
  	[NFQNL_MSG_CONFIG]	= { .call = nfqnl_recv_config,
  				    .attr_count = NFQA_CFG_MAX,
  				    .policy = nfqa_cfg_policy },
  	[NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
  				    .attr_count = NFQA_MAX,
  				    .policy = nfqa_verdict_batch_policy },
  };
  
  static const struct nfnetlink_subsystem nfqnl_subsys = {
  	.name		= "nf_queue",
  	.subsys_id	= NFNL_SUBSYS_QUEUE,
  	.cb_count	= NFQNL_MSG_MAX,
  	.cb		= nfqnl_cb,
  };
  
  #ifdef CONFIG_PROC_FS
  struct iter_state {
  	struct seq_net_private p;
  	unsigned int bucket;
  };
  
  static struct hlist_node *get_first(struct seq_file *seq)
  {
  	struct iter_state *st = seq->private;
  	struct net *net;
  	struct nfnl_queue_net *q;
  
  	if (!st)
  		return NULL;
  
  	net = seq_file_net(seq);
  	q = nfnl_queue_pernet(net);
  	for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
  		if (!hlist_empty(&q->instance_table[st->bucket]))
  			return q->instance_table[st->bucket].first;
  	}
  	return NULL;
  }
  
  static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
  {
  	struct iter_state *st = seq->private;
  	struct net *net = seq_file_net(seq);
  
  	h = h->next;
  	while (!h) {
  		struct nfnl_queue_net *q;
  
  		if (++st->bucket >= INSTANCE_BUCKETS)
  			return NULL;
  
  		q = nfnl_queue_pernet(net);
  		h = q->instance_table[st->bucket].first;
  	}
  	return h;
  }
  
  static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
  {
  	struct hlist_node *head;
  	head = get_first(seq);
  
  	if (head)
  		while (pos && (head = get_next(seq, head)))
  			pos--;
  	return pos ? NULL : head;
  }
  
  static void *seq_start(struct seq_file *s, loff_t *pos)
  	__acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
  {
  	spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
  	return get_idx(s, *pos);
  }
  
  static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
  {
  	(*pos)++;
  	return get_next(s, v);
  }
  
  static void seq_stop(struct seq_file *s, void *v)
  	__releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
  {
  	spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
  }
  
  static int seq_show(struct seq_file *s, void *v)
  {
  	const struct nfqnl_instance *inst = v;
  
  	seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
  		   inst->queue_num,
  		   inst->peer_portid, inst->queue_total,
  		   inst->copy_mode, inst->copy_range,
  		   inst->queue_dropped, inst->queue_user_dropped,
  		   inst->id_sequence, 1);
  	return 0;
  }
  
  static const struct seq_operations nfqnl_seq_ops = {
  	.start	= seq_start,
  	.next	= seq_next,
  	.stop	= seq_stop,
  	.show	= seq_show,
  };
  #endif /* PROC_FS */
  
  static int __net_init nfnl_queue_net_init(struct net *net)
  {
  	unsigned int i;
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  
  	for (i = 0; i < INSTANCE_BUCKETS; i++)
  		INIT_HLIST_HEAD(&q->instance_table[i]);
  
  	spin_lock_init(&q->instances_lock);
  
  #ifdef CONFIG_PROC_FS
  	if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
  			&nfqnl_seq_ops, sizeof(struct iter_state)))
  		return -ENOMEM;
  #endif
  	nf_register_queue_handler(net, &nfqh);
  	return 0;
  }
  
  static void __net_exit nfnl_queue_net_exit(struct net *net)
  {
  	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  	unsigned int i;
  
  	nf_unregister_queue_handler(net);
  #ifdef CONFIG_PROC_FS
  	remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
  #endif
  	for (i = 0; i < INSTANCE_BUCKETS; i++)
  		WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
  }
  
  static void nfnl_queue_net_exit_batch(struct list_head *net_exit_list)
  {
  	synchronize_rcu();
  }
  
  static struct pernet_operations nfnl_queue_net_ops = {
  	.init		= nfnl_queue_net_init,
  	.exit		= nfnl_queue_net_exit,
  	.exit_batch	= nfnl_queue_net_exit_batch,
  	.id		= &nfnl_queue_net_id,
  	.size		= sizeof(struct nfnl_queue_net),
  };
  
  static int __init nfnetlink_queue_init(void)
  {
  	int status;
  
  	status = register_pernet_subsys(&nfnl_queue_net_ops);
  	if (status < 0) {
  		pr_err("failed to register pernet ops\n");
  		goto out;
  	}
  
  	netlink_register_notifier(&nfqnl_rtnl_notifier);
  	status = nfnetlink_subsys_register(&nfqnl_subsys);
  	if (status < 0) {
  		pr_err("failed to create netlink socket\n");
  		goto cleanup_netlink_notifier;
  	}
  
  	status = register_netdevice_notifier(&nfqnl_dev_notifier);
  	if (status < 0) {
  		pr_err("failed to register netdevice notifier\n");
  		goto cleanup_netlink_subsys;
  	}
  
  	return status;
  
  cleanup_netlink_subsys:
  	nfnetlink_subsys_unregister(&nfqnl_subsys);
  cleanup_netlink_notifier:
  	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
  	unregister_pernet_subsys(&nfnl_queue_net_ops);
  out:
  	return status;
  }
  
  static void __exit nfnetlink_queue_fini(void)
  {
  	unregister_netdevice_notifier(&nfqnl_dev_notifier);
  	nfnetlink_subsys_unregister(&nfqnl_subsys);
  	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
  	unregister_pernet_subsys(&nfnl_queue_net_ops);
  
  	rcu_barrier(); /* Wait for completion of call_rcu()'s */
  }
  
  MODULE_DESCRIPTION("netfilter packet queue handler");
  MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
  
  module_init(nfnetlink_queue_init);
  module_exit(nfnetlink_queue_fini);
  