patch-2.4.18 linux/net/ipv6/netfilter/ip6_queue.c

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diff -Naur -X /home/marcelo/lib/dontdiff linux.orig/net/ipv6/netfilter/ip6_queue.c linux/net/ipv6/netfilter/ip6_queue.c
@@ -0,0 +1,721 @@
+/*
+ * This is a module which is used for queueing IPv6 packets and
+ * communicating with userspace via netlink.
+ *
+ * (C) 2001 Fernando Anton, this code is GPL.
+ *     IPv64 Project - Work based in IPv64 draft by Arturo Azcorra.
+ *     Universidad Carlos III de Madrid - Leganes (Madrid) - Spain
+ *     Universidad Politecnica de Alcala de Henares - Alcala de H. (Madrid) - Spain
+ *     email: fanton@it.uc3m.es
+ *
+ * 2001-11-06: First try. Working with ip_queue.c for IPv4 and trying
+ *             to adapt it to IPv6
+ *             HEAVILY based in ipqueue.c by James Morris. It's just
+ *             a little modified version of it, so he's nearly the
+ *             real coder of this.
+ *             Few changes needed, mainly the hard_routing code and
+ *             the netlink socket protocol (we're NETLINK_IP6_FW).
+ *
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/ipv6.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/netlink.h>
+#include <linux/spinlock.h>
+#include <linux/rtnetlink.h>
+#include <linux/sysctl.h>
+#include <linux/proc_fs.h>
+#include <net/sock.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+
+/* We're still usign the following structs. No need to change them: */
+/*   ipq_packet_msg                                                 */
+/*   ipq_mode_msg                                                   */
+/*   ipq_verdict_msg                                                */
+/*   ipq_peer_msg                                                   */
+#include <linux/netfilter_ipv4/ip_queue.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+#define IPQ_QMAX_DEFAULT 1024
+#define IPQ_PROC_FS_NAME "ip6_queue"
+#define NET_IPQ_QMAX 2088
+#define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
+
+typedef struct ip6q_rt_info {
+	struct in6_addr daddr;
+	struct in6_addr saddr;
+} ip6q_rt_info_t;
+
+typedef struct ip6q_queue_element {
+	struct list_head list;		/* Links element into queue */
+	int verdict;			/* Current verdict */
+	struct nf_info *info;		/* Extra info from netfilter */
+	struct sk_buff *skb;		/* Packet inside */
+	ip6q_rt_info_t rt_info;		/* May need post-mangle routing */
+} ip6q_queue_element_t;
+
+typedef int (*ip6q_send_cb_t)(ip6q_queue_element_t *e);
+
+typedef struct ip6q_peer {
+	pid_t pid;			/* PID of userland peer */
+	unsigned char died;		/* We think the peer died */
+	unsigned char copy_mode;	/* Copy packet as well as metadata? */
+	size_t copy_range;		/* Range past metadata to copy */
+	ip6q_send_cb_t send;		/* Callback for sending data to peer */
+} ip6q_peer_t;
+
+typedef struct ip6q_queue {
+ 	int len;			/* Current queue len */
+ 	int *maxlen;			/* Maximum queue len, via sysctl */
+ 	unsigned char flushing;		/* If queue is being flushed */
+ 	unsigned char terminate;	/* If the queue is being terminated */
+ 	struct list_head list;		/* Head of packet queue */
+ 	spinlock_t lock;		/* Queue spinlock */
+ 	ip6q_peer_t peer;		/* Userland peer */
+} ip6q_queue_t;
+
+/****************************************************************************
+ *
+ * Packet queue
+ *
+ ****************************************************************************/
+/* Dequeue a packet if matched by cmp, or the next available if cmp is NULL */
+static ip6q_queue_element_t *
+ip6q_dequeue(ip6q_queue_t *q,
+            int (*cmp)(ip6q_queue_element_t *, unsigned long),
+            unsigned long data)
+{
+	struct list_head *i;
+
+	spin_lock_bh(&q->lock);
+	for (i = q->list.prev; i != &q->list; i = i->prev) {
+		ip6q_queue_element_t *e = (ip6q_queue_element_t *)i;
+		
+		if (!cmp || cmp(e, data)) {
+			list_del(&e->list);
+			q->len--;
+			spin_unlock_bh(&q->lock);
+			return e;
+		}
+	}
+	spin_unlock_bh(&q->lock);
+	return NULL;
+}
+
+/* Flush all packets */
+static void ip6q_flush(ip6q_queue_t *q)
+{
+	ip6q_queue_element_t *e;
+	
+	spin_lock_bh(&q->lock);
+	q->flushing = 1;
+	spin_unlock_bh(&q->lock);
+	while ((e = ip6q_dequeue(q, NULL, 0))) {
+		e->verdict = NF_DROP;
+		nf_reinject(e->skb, e->info, e->verdict);
+		kfree(e);
+	}
+	spin_lock_bh(&q->lock);
+	q->flushing = 0;
+	spin_unlock_bh(&q->lock);
+}
+
+static ip6q_queue_t *ip6q_create_queue(nf_queue_outfn_t outfn,
+                                     ip6q_send_cb_t send_cb,
+                                     int *errp, int *sysctl_qmax)
+{
+	int status;
+	ip6q_queue_t *q;
+
+	*errp = 0;
+	q = kmalloc(sizeof(ip6q_queue_t), GFP_KERNEL);
+	if (q == NULL) {
+		*errp = -ENOMEM;
+		return NULL;
+	}
+	q->peer.pid = 0;
+	q->peer.died = 0;
+	q->peer.copy_mode = IPQ_COPY_NONE;
+	q->peer.copy_range = 0;
+	q->peer.send = send_cb;
+	q->len = 0;
+	q->maxlen = sysctl_qmax;
+	q->flushing = 0;
+	q->terminate = 0;
+	INIT_LIST_HEAD(&q->list);
+	spin_lock_init(&q->lock);
+	status = nf_register_queue_handler(PF_INET6, outfn, q);
+	if (status < 0) {
+		*errp = -EBUSY;
+		kfree(q);
+		return NULL;
+	}
+	return q;
+}
+
+static int ip6q_enqueue(ip6q_queue_t *q,
+                       struct sk_buff *skb, struct nf_info *info)
+{
+	ip6q_queue_element_t *e;
+	int status;
+	
+	e = kmalloc(sizeof(*e), GFP_ATOMIC);
+	if (e == NULL) {
+		printk(KERN_ERR "ip6_queue: OOM in enqueue\n");
+		return -ENOMEM;
+	}
+
+	e->verdict = NF_DROP;
+	e->info = info;
+	e->skb = skb;
+
+	if (e->info->hook == NF_IP_LOCAL_OUT) {
+		struct ipv6hdr *iph = skb->nh.ipv6h;
+
+		e->rt_info.daddr = iph->daddr;
+		e->rt_info.saddr = iph->saddr;
+	}
+
+	spin_lock_bh(&q->lock);
+	if (q->len >= *q->maxlen) {
+		spin_unlock_bh(&q->lock);
+		if (net_ratelimit()) 
+			printk(KERN_WARNING "ip6_queue: full at %d entries, "
+			       "dropping packet(s).\n", q->len);
+		goto free_drop;
+	}
+	if (q->flushing || q->peer.copy_mode == IPQ_COPY_NONE
+	    || q->peer.pid == 0 || q->peer.died || q->terminate) {
+		spin_unlock_bh(&q->lock);
+		goto free_drop;
+	}
+	status = q->peer.send(e);
+	if (status > 0) {
+		list_add(&e->list, &q->list);
+		q->len++;
+		spin_unlock_bh(&q->lock);
+		return status;
+	}
+	spin_unlock_bh(&q->lock);
+	if (status == -ECONNREFUSED) {
+		printk(KERN_INFO "ip6_queue: peer %d died, "
+		       "resetting state and flushing queue\n", q->peer.pid);
+			q->peer.died = 1;
+			q->peer.pid = 0;
+			q->peer.copy_mode = IPQ_COPY_NONE;
+			q->peer.copy_range = 0;
+			ip6q_flush(q);
+	}
+free_drop:
+	kfree(e);
+	return -EBUSY;
+}
+
+static void ip6q_destroy_queue(ip6q_queue_t *q)
+{
+	nf_unregister_queue_handler(PF_INET6);
+	spin_lock_bh(&q->lock);
+	q->terminate = 1;
+	spin_unlock_bh(&q->lock);
+	ip6q_flush(q);
+	kfree(q);
+}
+
+/*
+ * Taken from net/ipv6/ip6_output.c
+ *
+ * We should use the one there, but is defined static
+ * so we put this just here and let the things as
+ * they are now.
+ *
+ * If that one is modified, this one should be modified too.
+ */
+static int route6_me_harder(struct sk_buff *skb)
+{
+	struct ipv6hdr *iph = skb->nh.ipv6h;
+	struct dst_entry *dst;
+	struct flowi fl;
+
+	fl.proto = iph->nexthdr;
+	fl.fl6_dst = &iph->daddr;
+	fl.fl6_src = &iph->saddr;
+	fl.oif = skb->sk ? skb->sk->bound_dev_if : 0;
+	fl.fl6_flowlabel = 0;
+	fl.uli_u.ports.dport = 0;
+	fl.uli_u.ports.sport = 0;
+
+	dst = ip6_route_output(skb->sk, &fl);
+
+	if (dst->error) {
+		if (net_ratelimit())
+			printk(KERN_DEBUG "route6_me_harder: No more route.\n");
+		return -EINVAL;
+	}
+
+	/* Drop old route. */
+	dst_release(skb->dst);
+
+	skb->dst = dst;
+	return 0;
+}
+static int ip6q_mangle_ipv6(ipq_verdict_msg_t *v, ip6q_queue_element_t *e)
+{
+	int diff;
+	struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
+
+	if (v->data_len < sizeof(*user_iph))
+		return 0;
+	diff = v->data_len - e->skb->len;
+	if (diff < 0)
+		skb_trim(e->skb, v->data_len);
+	else if (diff > 0) {
+		if (v->data_len > 0xFFFF)
+			return -EINVAL;
+		if (diff > skb_tailroom(e->skb)) {
+			struct sk_buff *newskb;
+			
+			newskb = skb_copy_expand(e->skb,
+			                         skb_headroom(e->skb),
+			                         diff,
+			                         GFP_ATOMIC);
+			if (newskb == NULL) {
+				printk(KERN_WARNING "ip6_queue: OOM "
+				      "in mangle, dropping packet\n");
+				return -ENOMEM;
+			}
+			if (e->skb->sk)
+				skb_set_owner_w(newskb, e->skb->sk);
+			kfree_skb(e->skb);
+			e->skb = newskb;
+		}
+		skb_put(e->skb, diff);
+	}
+	memcpy(e->skb->data, v->payload, v->data_len);
+	e->skb->nfcache |= NFC_ALTERED;
+
+	/*
+	 * Extra routing may needed on local out, as the QUEUE target never
+	 * returns control to the table.
+         * Not a nice way to cmp, but works
+	 */
+	if (e->info->hook == NF_IP_LOCAL_OUT) {
+		struct ipv6hdr *iph = e->skb->nh.ipv6h;
+		if (!(   iph->daddr.in6_u.u6_addr32[0] == e->rt_info.daddr.in6_u.u6_addr32[0]
+                      && iph->daddr.in6_u.u6_addr32[1] == e->rt_info.daddr.in6_u.u6_addr32[1]
+                      && iph->daddr.in6_u.u6_addr32[2] == e->rt_info.daddr.in6_u.u6_addr32[2]
+                      && iph->daddr.in6_u.u6_addr32[3] == e->rt_info.daddr.in6_u.u6_addr32[3]
+		      && iph->saddr.in6_u.u6_addr32[0] == e->rt_info.saddr.in6_u.u6_addr32[0]
+		      && iph->saddr.in6_u.u6_addr32[1] == e->rt_info.saddr.in6_u.u6_addr32[1]
+		      && iph->saddr.in6_u.u6_addr32[2] == e->rt_info.saddr.in6_u.u6_addr32[2]
+		      && iph->saddr.in6_u.u6_addr32[3] == e->rt_info.saddr.in6_u.u6_addr32[3]))
+			return route6_me_harder(e->skb);
+	}
+	return 0;
+}
+
+static inline int id_cmp(ip6q_queue_element_t *e, unsigned long id)
+{
+	return (id == (unsigned long )e);
+}
+
+static int ip6q_set_verdict(ip6q_queue_t *q,
+                           ipq_verdict_msg_t *v, unsigned int len)
+{
+	ip6q_queue_element_t *e;
+
+	if (v->value > NF_MAX_VERDICT)
+		return -EINVAL;
+	e = ip6q_dequeue(q, id_cmp, v->id);
+	if (e == NULL)
+		return -ENOENT;
+	else {
+		e->verdict = v->value;
+		if (v->data_len && v->data_len == len)
+			if (ip6q_mangle_ipv6(v, e) < 0)
+				e->verdict = NF_DROP;
+		nf_reinject(e->skb, e->info, e->verdict);
+		kfree(e);
+		return 0;
+	}
+}
+
+static int ip6q_receive_peer(ip6q_queue_t* q, ipq_peer_msg_t *m,
+                            unsigned char type, unsigned int len)
+{
+
+	int status = 0;
+	int busy;
+		
+	spin_lock_bh(&q->lock);
+	busy = (q->terminate || q->flushing);
+	spin_unlock_bh(&q->lock);
+	if (busy)
+		return -EBUSY;
+	if (len < sizeof(ipq_peer_msg_t))
+		return -EINVAL;
+	switch (type) {
+		case IPQM_MODE:
+			switch (m->msg.mode.value) {
+				case IPQ_COPY_META:
+					q->peer.copy_mode = IPQ_COPY_META;
+					q->peer.copy_range = 0;
+					break;
+				case IPQ_COPY_PACKET:
+					q->peer.copy_mode = IPQ_COPY_PACKET;
+					q->peer.copy_range = m->msg.mode.range;
+					if (q->peer.copy_range > 0xFFFF)
+						q->peer.copy_range = 0xFFFF;
+					break;
+				default:
+					status = -EINVAL;
+			}
+			break;
+		case IPQM_VERDICT:
+			if (m->msg.verdict.value > NF_MAX_VERDICT)
+				status = -EINVAL;
+			else
+				status = ip6q_set_verdict(q,
+				                         &m->msg.verdict,
+				                         len - sizeof(*m));
+			break;
+		default:
+			 status = -EINVAL;
+	}
+	return status;
+}
+
+static inline int dev_cmp(ip6q_queue_element_t *e, unsigned long ifindex)
+{
+	if (e->info->indev)
+		if (e->info->indev->ifindex == ifindex)
+			return 1;
+	if (e->info->outdev)
+		if (e->info->outdev->ifindex == ifindex)
+			return 1;
+	return 0;
+}
+
+/* Drop any queued packets associated with device ifindex */
+static void ip6q_dev_drop(ip6q_queue_t *q, int ifindex)
+{
+	ip6q_queue_element_t *e;
+	
+	while ((e = ip6q_dequeue(q, dev_cmp, ifindex))) {
+		e->verdict = NF_DROP;
+		nf_reinject(e->skb, e->info, e->verdict);
+		kfree(e);
+	}
+}
+
+/****************************************************************************
+ *
+ * Netfilter interface
+ *
+ ****************************************************************************/
+
+/*
+ * Packets arrive here from netfilter for queuing to userspace.
+ * All of them must be fed back via nf_reinject() or Alexey will kill Rusty.
+ */
+static int netfilter6_receive(struct sk_buff *skb,
+                             struct nf_info *info, void *data)
+{
+	return ip6q_enqueue((ip6q_queue_t *)data, skb, info);
+}
+
+/****************************************************************************
+ *
+ * Netlink interface.
+ *
+ ****************************************************************************/
+
+static struct sock *nfnl = NULL;
+/* This is not a static one, so we should not repeat its name */
+ip6q_queue_t *nlq6 = NULL;
+
+static struct sk_buff *netlink_build_message(ip6q_queue_element_t *e, int *errp)
+{
+	unsigned char *old_tail;
+	size_t size = 0;
+	size_t data_len = 0;
+	struct sk_buff *skb;
+	ipq_packet_msg_t *pm;
+	struct nlmsghdr *nlh;
+
+	switch (nlq6->peer.copy_mode) {
+		size_t copy_range;
+
+		case IPQ_COPY_META:
+			size = NLMSG_SPACE(sizeof(*pm));
+			data_len = 0;
+			break;
+		case IPQ_COPY_PACKET:
+			copy_range = nlq6->peer.copy_range;
+			if (copy_range == 0 || copy_range > e->skb->len)
+				data_len = e->skb->len;
+			else
+				data_len = copy_range;
+			size = NLMSG_SPACE(sizeof(*pm) + data_len);
+			
+			break;
+		case IPQ_COPY_NONE:
+		default:
+			*errp = -EINVAL;
+			return NULL;
+	}
+	skb = alloc_skb(size, GFP_ATOMIC);
+	if (!skb)
+		goto nlmsg_failure;
+	old_tail = skb->tail;
+	nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
+	pm = NLMSG_DATA(nlh);
+	memset(pm, 0, sizeof(*pm));
+	pm->packet_id = (unsigned long )e;
+	pm->data_len = data_len;
+	pm->timestamp_sec = e->skb->stamp.tv_sec;
+	pm->timestamp_usec = e->skb->stamp.tv_usec;
+	pm->mark = e->skb->nfmark;
+	pm->hook = e->info->hook;
+	if (e->info->indev) strcpy(pm->indev_name, e->info->indev->name);
+	else pm->indev_name[0] = '\0';
+	if (e->info->outdev) strcpy(pm->outdev_name, e->info->outdev->name);
+	else pm->outdev_name[0] = '\0';
+	pm->hw_protocol = e->skb->protocol;
+	if (e->info->indev && e->skb->dev) {
+		pm->hw_type = e->skb->dev->type;
+		if (e->skb->dev->hard_header_parse)
+			pm->hw_addrlen =
+				e->skb->dev->hard_header_parse(e->skb,
+				                               pm->hw_addr);
+	}
+	if (data_len)
+		memcpy(pm->payload, e->skb->data, data_len);
+	nlh->nlmsg_len = skb->tail - old_tail;
+	NETLINK_CB(skb).dst_groups = 0;
+	return skb;
+nlmsg_failure:
+	if (skb)
+		kfree_skb(skb);
+	*errp = 0;
+	printk(KERN_ERR "ip6_queue: error creating netlink message\n");
+	return NULL;
+}
+
+static int netlink_send_peer(ip6q_queue_element_t *e)
+{
+	int status = 0;
+	struct sk_buff *skb;
+
+	skb = netlink_build_message(e, &status);
+	if (skb == NULL)
+		return status;
+	return netlink_unicast(nfnl, skb, nlq6->peer.pid, MSG_DONTWAIT);
+}
+
+#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0);
+
+static __inline__ void netlink_receive_user_skb(struct sk_buff *skb)
+{
+	int status, type;
+	struct nlmsghdr *nlh;
+
+	if (skb->len < sizeof(struct nlmsghdr))
+		return;
+
+	nlh = (struct nlmsghdr *)skb->data;
+	if (nlh->nlmsg_len < sizeof(struct nlmsghdr)
+	    || skb->len < nlh->nlmsg_len)
+	    	return;
+
+	if(nlh->nlmsg_pid <= 0
+	    || !(nlh->nlmsg_flags & NLM_F_REQUEST)
+	    || nlh->nlmsg_flags & NLM_F_MULTI)
+		RCV_SKB_FAIL(-EINVAL);
+	if (nlh->nlmsg_flags & MSG_TRUNC)
+		RCV_SKB_FAIL(-ECOMM);
+	type = nlh->nlmsg_type;
+	if (type < NLMSG_NOOP || type >= IPQM_MAX)
+		RCV_SKB_FAIL(-EINVAL);
+	if (type <= IPQM_BASE)
+		return;
+	if(!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
+		RCV_SKB_FAIL(-EPERM);
+	if (nlq6->peer.pid && !nlq6->peer.died
+	    && (nlq6->peer.pid != nlh->nlmsg_pid)) {
+	    	printk(KERN_WARNING "ip6_queue: peer pid changed from %d to "
+	    	      "%d, flushing queue\n", nlq6->peer.pid, nlh->nlmsg_pid);
+		ip6q_flush(nlq6);
+	}	
+	nlq6->peer.pid = nlh->nlmsg_pid;
+	nlq6->peer.died = 0;
+	status = ip6q_receive_peer(nlq6, NLMSG_DATA(nlh),
+	                          type, skb->len - NLMSG_LENGTH(0));
+	if (status < 0)
+		RCV_SKB_FAIL(status);
+	if (nlh->nlmsg_flags & NLM_F_ACK)
+		netlink_ack(skb, nlh, 0);
+        return;
+}
+
+/* Note: we are only dealing with single part messages at the moment. */
+static void netlink_receive_user_sk(struct sock *sk, int len)
+{
+	do {
+		struct sk_buff *skb;
+
+		if (rtnl_shlock_nowait())
+			return;
+		while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
+			netlink_receive_user_skb(skb);
+			kfree_skb(skb);
+		}
+		up(&rtnl_sem);
+	} while (nfnl && nfnl->receive_queue.qlen);
+}
+
+/****************************************************************************
+ *
+ * System events
+ *
+ ****************************************************************************/
+
+static int receive_event(struct notifier_block *this,
+                         unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+
+	/* Drop any packets associated with the downed device */
+	if (event == NETDEV_DOWN)
+		ip6q_dev_drop(nlq6, dev->ifindex);
+	return NOTIFY_DONE;
+}
+
+struct notifier_block ip6q_dev_notifier = {
+	receive_event,
+	NULL,
+	0
+};
+
+/****************************************************************************
+ *
+ * Sysctl - queue tuning.
+ *
+ ****************************************************************************/
+
+static int sysctl_maxlen = IPQ_QMAX_DEFAULT;
+
+static struct ctl_table_header *ip6q_sysctl_header;
+
+static ctl_table ip6q_table[] = {
+	{ NET_IPQ_QMAX, NET_IPQ_QMAX_NAME, &sysctl_maxlen,
+	  sizeof(sysctl_maxlen), 0644,  NULL, proc_dointvec },
+ 	{ 0 }
+};
+
+static ctl_table ip6q_dir_table[] = {
+	{NET_IPV6, "ipv6", NULL, 0, 0555, ip6q_table, 0, 0, 0, 0, 0},
+	{ 0 }
+};
+
+static ctl_table ip6q_root_table[] = {
+	{CTL_NET, "net", NULL, 0, 0555, ip6q_dir_table, 0, 0, 0, 0, 0},
+	{ 0 }
+};
+
+/****************************************************************************
+ *
+ * Procfs - debugging info.
+ *
+ ****************************************************************************/
+
+static int ip6q_get_info(char *buffer, char **start, off_t offset, int length)
+{
+	int len;
+
+	spin_lock_bh(&nlq6->lock);
+	len = sprintf(buffer,
+	              "Peer pid            : %d\n"
+	              "Peer died           : %d\n"
+	              "Peer copy mode      : %d\n"
+	              "Peer copy range     : %Zu\n"
+	              "Queue length        : %d\n"
+	              "Queue max. length   : %d\n"
+	              "Queue flushing      : %d\n"
+	              "Queue terminate     : %d\n",
+	              nlq6->peer.pid,
+	              nlq6->peer.died,
+	              nlq6->peer.copy_mode,
+	              nlq6->peer.copy_range,
+	              nlq6->len,
+	              *nlq6->maxlen,
+	              nlq6->flushing,
+	              nlq6->terminate);
+	spin_unlock_bh(&nlq6->lock);
+	*start = buffer + offset;
+	len -= offset;
+	if (len > length)
+		len = length;
+	else if (len < 0)
+		len = 0;
+	return len;
+}
+
+/****************************************************************************
+ *
+ * Module stuff.
+ *
+ ****************************************************************************/
+
+static int __init init(void)
+{
+	int status = 0;
+	struct proc_dir_entry *proc;
+	
+        /* We must create the NETLINK_IP6_FW protocol service */
+	nfnl = netlink_kernel_create(NETLINK_IP6_FW, netlink_receive_user_sk);
+	if (nfnl == NULL) {
+		printk(KERN_ERR "ip6_queue: initialisation failed: unable to "
+		       "create kernel netlink socket\n");
+		return -ENOMEM;
+	}
+	nlq6 = ip6q_create_queue(netfilter6_receive,
+	                       netlink_send_peer, &status, &sysctl_maxlen);
+	if (nlq6 == NULL) {
+		printk(KERN_ERR "ip6_queue: initialisation failed: unable to "
+		       "create queue\n");
+		sock_release(nfnl->socket);
+		return status;
+	}
+        /* The file will be /proc/net/ip6_queue */
+	proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ip6q_get_info);
+	if (proc) proc->owner = THIS_MODULE;
+	else {
+		ip6q_destroy_queue(nlq6);
+		sock_release(nfnl->socket);
+		return -ENOMEM;
+	}
+	register_netdevice_notifier(&ip6q_dev_notifier);
+	ip6q_sysctl_header = register_sysctl_table(ip6q_root_table, 0);
+	return status;
+}
+
+static void __exit fini(void)
+{
+	unregister_sysctl_table(ip6q_sysctl_header);
+	proc_net_remove(IPQ_PROC_FS_NAME);
+	unregister_netdevice_notifier(&ip6q_dev_notifier);
+	ip6q_destroy_queue(nlq6);
+	sock_release(nfnl->socket);
+}
+
+MODULE_DESCRIPTION("IPv6 packet queue handler");
+MODULE_LICENSE("GPL");
+
+module_init(init);
+module_exit(fini);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)