net/ipv6/xfrm6_policy.c - kernel/msm-4.9 - Gitiles

 /*
  * xfrm6_policy.c: based on xfrm4_policy.c
  *
  * Authors:
  *	Mitsuru KANDA @USAGI
  *	Kazunori MIYAZAWA @USAGI
  *	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
  *		IPv6 support
  *	YOSHIFUJI Hideaki
  *		Split up af-specific portion
  *
  */

 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
 #include <net/addrconf.h>
 #include <net/dst.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 #include <net/mip6.h>
 #endif

 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;

 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos,
 					  const xfrm_address_t *saddr,
 					  const xfrm_address_t *daddr)
 {
 	struct flowi6 fl6;
 	struct dst_entry *dst;
 	int err;

 	memset(&fl6, 0, sizeof(fl6));
 	memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
 	if (saddr)
 		memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));

 	dst = ip6_route_output(net, NULL, &fl6);

 	err = dst->error;
 	if (dst->error) {
 		dst_release(dst);
 		dst = ERR_PTR(err);
 	}

 	return dst;
 }

 static int xfrm6_get_saddr(struct net *net,
 			   xfrm_address_t *saddr, xfrm_address_t *daddr)
 {
 	struct dst_entry *dst;
 	struct net_device *dev;

 	dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
 	if (IS_ERR(dst))
 		return -EHOSTUNREACH;

 	dev = ip6_dst_idev(dst)->dev;
 	ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
 	dst_release(dst);
 	return 0;
 }

 static int xfrm6_get_tos(const struct flowi *fl)
 {
 	return 0;
 }

 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
 			   int nfheader_len)
 {
 	if (dst->ops->family == AF_INET6) {
 		struct rt6_info *rt = (struct rt6_info *)dst;
 		path->path_cookie = rt6_get_cookie(rt);
 	}

 	path->u.rt6.rt6i_nfheader_len = nfheader_len;

 	return 0;
 }

 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 			  const struct flowi *fl)
 {
 	struct rt6_info *rt = (struct rt6_info *)xdst->route;

 	xdst->u.dst.dev = dev;
 	dev_hold(dev);

 	xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
 	if (!xdst->u.rt6.rt6i_idev) {
 		dev_put(dev);
 		return -ENODEV;
 	}

 	/* Sheit... I remember I did this right. Apparently,
 	 * it was magically lost, so this code needs audit */
 	xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
 						   RTF_LOCAL);
 	xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
 	xdst->u.rt6.rt6i_node = rt->rt6i_node;
 	xdst->route_cookie = rt6_get_cookie(rt);
 	xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
 	xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
 	xdst->u.rt6.rt6i_src = rt->rt6i_src;

 	return 0;
 }

 static inline void
 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
 {
 	struct flowi6 *fl6 = &fl->u.ip6;
 	int onlyproto = 0;
 	const struct ipv6hdr *hdr = ipv6_hdr(skb);
 	u16 offset = sizeof(*hdr);
 	struct ipv6_opt_hdr *exthdr;
 	const unsigned char *nh = skb_network_header(skb);
 	u16 nhoff = IP6CB(skb)->nhoff;
 	int oif = 0;
 	u8 nexthdr;

 	if (!nhoff)
 		nhoff = offsetof(struct ipv6hdr, nexthdr);

 	nexthdr = nh[nhoff];

 	if (skb_dst(skb))
 		oif = skb_dst(skb)->dev->ifindex;

 	memset(fl6, 0, sizeof(struct flowi6));
 	fl6->flowi6_mark = skb->mark;
 	fl6->flowi6_oif = reverse ? skb->skb_iif : oif;

 	fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
 	fl6->saddr = reverse ? hdr->daddr : hdr->saddr;

 	while (nh + offset + 1 < skb->data ||
 	       pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
 		nh = skb_network_header(skb);
 		exthdr = (struct ipv6_opt_hdr *)(nh + offset);

 		switch (nexthdr) {
 		case NEXTHDR_FRAGMENT:
 			onlyproto = 1;
 		case NEXTHDR_ROUTING:
 		case NEXTHDR_HOP:
 		case NEXTHDR_DEST:
 			offset += ipv6_optlen(exthdr);
 			nexthdr = exthdr->nexthdr;
 			exthdr = (struct ipv6_opt_hdr *)(nh + offset);
 			break;

 		case IPPROTO_UDP:
 		case IPPROTO_UDPLITE:
 		case IPPROTO_TCP:
 		case IPPROTO_SCTP:
 		case IPPROTO_DCCP:
 			if (!onlyproto && (nh + offset + 4 < skb->data ||
 			     pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
 				__be16 *ports;

 				nh = skb_network_header(skb);
 				ports = (__be16 *)(nh + offset);
 				fl6->fl6_sport = ports[!!reverse];
 				fl6->fl6_dport = ports[!reverse];
 			}
 			fl6->flowi6_proto = nexthdr;
 			return;

 		case IPPROTO_ICMPV6:
 			if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
 				u8 *icmp;

 				nh = skb_network_header(skb);
 				icmp = (u8 *)(nh + offset);
 				fl6->fl6_icmp_type = icmp[0];
 				fl6->fl6_icmp_code = icmp[1];
 			}
 			fl6->flowi6_proto = nexthdr;
 			return;

 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 		case IPPROTO_MH:
 			offset += ipv6_optlen(exthdr);
 			if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
 				struct ip6_mh *mh;

 				nh = skb_network_header(skb);
 				mh = (struct ip6_mh *)(nh + offset);
 				fl6->fl6_mh_type = mh->ip6mh_type;
 			}
 			fl6->flowi6_proto = nexthdr;
 			return;
 #endif

 		/* XXX Why are there these headers? */
 		case IPPROTO_AH:
 		case IPPROTO_ESP:
 		case IPPROTO_COMP:
 		default:
 			fl6->fl6_ipsec_spi = 0;
 			fl6->flowi6_proto = nexthdr;
 			return;
 		}
 	}
 }

 static inline int xfrm6_garbage_collect(struct dst_ops *ops)
 {
 	struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);

 	xfrm6_policy_afinfo.garbage_collect(net);
 	return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
 }

 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
 			      struct sk_buff *skb, u32 mtu)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 	struct dst_entry *path = xdst->route;

 	path->ops->update_pmtu(path, sk, skb, mtu);
 }

 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
 			   struct sk_buff *skb)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 	struct dst_entry *path = xdst->route;

 	path->ops->redirect(path, sk, skb);
 }

 static void xfrm6_dst_destroy(struct dst_entry *dst)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;

 	if (likely(xdst->u.rt6.rt6i_idev))
 		in6_dev_put(xdst->u.rt6.rt6i_idev);
 	dst_destroy_metrics_generic(dst);
 	xfrm_dst_destroy(xdst);
 }

 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 			     int unregister)
 {
 	struct xfrm_dst *xdst;

 	if (!unregister)
 		return;

 	xdst = (struct xfrm_dst *)dst;
 	if (xdst->u.rt6.rt6i_idev->dev == dev) {
 		struct inet6_dev *loopback_idev =
 			in6_dev_get(dev_net(dev)->loopback_dev);
 		BUG_ON(!loopback_idev);

 		do {
 			in6_dev_put(xdst->u.rt6.rt6i_idev);
 			xdst->u.rt6.rt6i_idev = loopback_idev;
 			in6_dev_hold(loopback_idev);
 			xdst = (struct xfrm_dst *)xdst->u.dst.child;
 		} while (xdst->u.dst.xfrm);

 		__in6_dev_put(loopback_idev);
 	}

 	xfrm_dst_ifdown(dst, dev);
 }

 static struct dst_ops xfrm6_dst_ops = {
 	.family =		AF_INET6,
 	.gc =			xfrm6_garbage_collect,
 	.update_pmtu =		xfrm6_update_pmtu,
 	.redirect =		xfrm6_redirect,
 	.cow_metrics =		dst_cow_metrics_generic,
 	.destroy =		xfrm6_dst_destroy,
 	.ifdown =		xfrm6_dst_ifdown,
 	.local_out =		__ip6_local_out,
 	.gc_thresh =		32768,
 };

 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
 	.family =		AF_INET6,
 	.dst_ops =		&xfrm6_dst_ops,
 	.dst_lookup =		xfrm6_dst_lookup,
 	.get_saddr =		xfrm6_get_saddr,
 	.decode_session =	_decode_session6,
 	.get_tos =		xfrm6_get_tos,
 	.init_path =		xfrm6_init_path,
 	.fill_dst =		xfrm6_fill_dst,
 	.blackhole_route =	ip6_blackhole_route,
 };

 static int __init xfrm6_policy_init(void)
 {
 	return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
 }

 static void xfrm6_policy_fini(void)
 {
 	xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
 }

 #ifdef CONFIG_SYSCTL
 static struct ctl_table xfrm6_policy_table[] = {
 	{
 		.procname       = "xfrm6_gc_thresh",
 		.data		= &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler   = proc_dointvec,
 	},
 	{ }
 };

 static int __net_init xfrm6_net_init(struct net *net)
 {
 	struct ctl_table *table;
 	struct ctl_table_header *hdr;

 	table = xfrm6_policy_table;
 	if (!net_eq(net, &init_net)) {
 		table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
 		if (!table)
 			goto err_alloc;

 		table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
 	}

 	hdr = register_net_sysctl(net, "net/ipv6", table);
 	if (!hdr)
 		goto err_reg;

 	net->ipv6.sysctl.xfrm6_hdr = hdr;
 	return 0;

 err_reg:
 	if (!net_eq(net, &init_net))
 		kfree(table);
 err_alloc:
 	return -ENOMEM;
 }

 static void __net_exit xfrm6_net_exit(struct net *net)
 {
 	struct ctl_table *table;

 	if (!net->ipv6.sysctl.xfrm6_hdr)
 		return;

 	table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
 	unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
 	if (!net_eq(net, &init_net))
 		kfree(table);
 }

 static struct pernet_operations xfrm6_net_ops = {
 	.init	= xfrm6_net_init,
 	.exit	= xfrm6_net_exit,
 };
 #endif

 int __init xfrm6_init(void)
 {
 	int ret;

 	dst_entries_init(&xfrm6_dst_ops);

 	ret = xfrm6_policy_init();
 	if (ret) {
 		dst_entries_destroy(&xfrm6_dst_ops);
 		goto out;
 	}
 	ret = xfrm6_state_init();
 	if (ret)
 		goto out_policy;

 	ret = xfrm6_protocol_init();
 	if (ret)
 		goto out_state;

 #ifdef CONFIG_SYSCTL
 	register_pernet_subsys(&xfrm6_net_ops);
 #endif
 out:
 	return ret;
 out_state:
 	xfrm6_state_fini();
 out_policy:
 	xfrm6_policy_fini();
 	goto out;
 }

 void xfrm6_fini(void)
 {
 #ifdef CONFIG_SYSCTL
 	unregister_pernet_subsys(&xfrm6_net_ops);
 #endif
 	xfrm6_protocol_fini();
 	xfrm6_policy_fini();
 	xfrm6_state_fini();
 	dst_entries_destroy(&xfrm6_dst_ops);
 }
	/*
	* xfrm6_policy.c: based on xfrm4_policy.c
	*
	* Authors:
	* Mitsuru KANDA @USAGI
	* Kazunori MIYAZAWA @USAGI
	* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
	* IPv6 support
	* YOSHIFUJI Hideaki
	* Split up af-specific portion
	*
	*/

	#include <linux/err.h>
	#include <linux/kernel.h>
	#include <linux/netdevice.h>
	#include <net/addrconf.h>
	#include <net/dst.h>
	#include <net/xfrm.h>
	#include <net/ip.h>
	#include <net/ipv6.h>
	#include <net/ip6_route.h>
	#if IS_ENABLED(CONFIG_IPV6_MIP6)
	#include <net/mip6.h>
	#endif

	static struct xfrm_policy_afinfo xfrm6_policy_afinfo;

	static struct dst_entry xfrm6_dst_lookup(struct net net, int tos,
	const xfrm_address_t *saddr,
	const xfrm_address_t *daddr)
	{
	struct flowi6 fl6;
	struct dst_entry *dst;
	int err;

	memset(&fl6, 0, sizeof(fl6));
	memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
	if (saddr)
	memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));

	dst = ip6_route_output(net, NULL, &fl6);

	err = dst->error;
	if (dst->error) {
	dst_release(dst);
	dst = ERR_PTR(err);
	}

	return dst;
	}

	static int xfrm6_get_saddr(struct net *net,
	xfrm_address_t saddr, xfrm_address_t daddr)
	{
	struct dst_entry *dst;
	struct net_device *dev;

	dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
	if (IS_ERR(dst))
	return -EHOSTUNREACH;

	dev = ip6_dst_idev(dst)->dev;
	ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
	dst_release(dst);
	return 0;
	}

	static int xfrm6_get_tos(const struct flowi *fl)
	{
	return 0;
	}

	static int xfrm6_init_path(struct xfrm_dst path, struct dst_entry dst,
	int nfheader_len)
	{
	if (dst->ops->family == AF_INET6) {
	struct rt6_info rt = (struct rt6_info )dst;
	path->path_cookie = rt6_get_cookie(rt);
	}

	path->u.rt6.rt6i_nfheader_len = nfheader_len;

	return 0;
	}

	static int xfrm6_fill_dst(struct xfrm_dst xdst, struct net_device dev,
	const struct flowi *fl)
	{
	struct rt6_info rt = (struct rt6_info )xdst->route;

	xdst->u.dst.dev = dev;
	dev_hold(dev);

	xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
	if (!xdst->u.rt6.rt6i_idev) {
	dev_put(dev);
	return -ENODEV;
	}

	/* Sheit... I remember I did this right. Apparently,
	* it was magically lost, so this code needs audit */
	xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST \|
	RTF_LOCAL);
	xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
	xdst->u.rt6.rt6i_node = rt->rt6i_node;
	xdst->route_cookie = rt6_get_cookie(rt);
	xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
	xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
	xdst->u.rt6.rt6i_src = rt->rt6i_src;

	return 0;
	}

	static inline void
	_decode_session6(struct sk_buff skb, struct flowi fl, int reverse)
	{
	struct flowi6 *fl6 = &fl->u.ip6;
	int onlyproto = 0;
	const struct ipv6hdr *hdr = ipv6_hdr(skb);
	u16 offset = sizeof(*hdr);
	struct ipv6_opt_hdr *exthdr;
	const unsigned char *nh = skb_network_header(skb);
	u16 nhoff = IP6CB(skb)->nhoff;
	int oif = 0;
	u8 nexthdr;

	if (!nhoff)
	nhoff = offsetof(struct ipv6hdr, nexthdr);

	nexthdr = nh[nhoff];

	if (skb_dst(skb))
	oif = skb_dst(skb)->dev->ifindex;

	memset(fl6, 0, sizeof(struct flowi6));
	fl6->flowi6_mark = skb->mark;
	fl6->flowi6_oif = reverse ? skb->skb_iif : oif;

	fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
	fl6->saddr = reverse ? hdr->daddr : hdr->saddr;

	while (nh + offset + 1 < skb->data \|\|
	pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
	nh = skb_network_header(skb);
	exthdr = (struct ipv6_opt_hdr *)(nh + offset);

	switch (nexthdr) {
	case NEXTHDR_FRAGMENT:
	onlyproto = 1;
	case NEXTHDR_ROUTING:
	case NEXTHDR_HOP:
	case NEXTHDR_DEST:
	offset += ipv6_optlen(exthdr);
	nexthdr = exthdr->nexthdr;
	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
	break;

	case IPPROTO_UDP:
	case IPPROTO_UDPLITE:
	case IPPROTO_TCP:
	case IPPROTO_SCTP:
	case IPPROTO_DCCP:
	if (!onlyproto && (nh + offset + 4 < skb->data \|\|
	pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
	__be16 *ports;

	nh = skb_network_header(skb);
	ports = (__be16 *)(nh + offset);
	fl6->fl6_sport = ports[!!reverse];
	fl6->fl6_dport = ports[!reverse];
	}
	fl6->flowi6_proto = nexthdr;
	return;

	case IPPROTO_ICMPV6:
	if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
	u8 *icmp;

	nh = skb_network_header(skb);
	icmp = (u8 *)(nh + offset);
	fl6->fl6_icmp_type = icmp[0];
	fl6->fl6_icmp_code = icmp[1];
	}
	fl6->flowi6_proto = nexthdr;
	return;

	#if IS_ENABLED(CONFIG_IPV6_MIP6)
	case IPPROTO_MH:
	offset += ipv6_optlen(exthdr);
	if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
	struct ip6_mh *mh;

	nh = skb_network_header(skb);
	mh = (struct ip6_mh *)(nh + offset);
	fl6->fl6_mh_type = mh->ip6mh_type;
	}
	fl6->flowi6_proto = nexthdr;
	return;
	#endif

	/* XXX Why are there these headers? */
	case IPPROTO_AH:
	case IPPROTO_ESP:
	case IPPROTO_COMP:
	default:
	fl6->fl6_ipsec_spi = 0;
	fl6->flowi6_proto = nexthdr;
	return;
	}
	}
	}

	static inline int xfrm6_garbage_collect(struct dst_ops *ops)
	{
	struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);

	xfrm6_policy_afinfo.garbage_collect(net);
	return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
	}

	static void xfrm6_update_pmtu(struct dst_entry dst, struct sock sk,
	struct sk_buff *skb, u32 mtu)
	{
	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	struct dst_entry *path = xdst->route;

	path->ops->update_pmtu(path, sk, skb, mtu);
	}

	static void xfrm6_redirect(struct dst_entry dst, struct sock sk,
	struct sk_buff *skb)
	{
	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	struct dst_entry *path = xdst->route;

	path->ops->redirect(path, sk, skb);
	}

	static void xfrm6_dst_destroy(struct dst_entry *dst)
	{
	struct xfrm_dst xdst = (struct xfrm_dst )dst;

	if (likely(xdst->u.rt6.rt6i_idev))
	in6_dev_put(xdst->u.rt6.rt6i_idev);
	dst_destroy_metrics_generic(dst);
	xfrm_dst_destroy(xdst);
	}

	static void xfrm6_dst_ifdown(struct dst_entry dst, struct net_device dev,
	int unregister)
	{
	struct xfrm_dst *xdst;

	if (!unregister)
	return;

	xdst = (struct xfrm_dst *)dst;
	if (xdst->u.rt6.rt6i_idev->dev == dev) {
	struct inet6_dev *loopback_idev =
	in6_dev_get(dev_net(dev)->loopback_dev);
	BUG_ON(!loopback_idev);

	do {
	in6_dev_put(xdst->u.rt6.rt6i_idev);
	xdst->u.rt6.rt6i_idev = loopback_idev;
	in6_dev_hold(loopback_idev);
	xdst = (struct xfrm_dst *)xdst->u.dst.child;
	} while (xdst->u.dst.xfrm);

	__in6_dev_put(loopback_idev);
	}

	xfrm_dst_ifdown(dst, dev);
	}

	static struct dst_ops xfrm6_dst_ops = {
	.family = AF_INET6,
	.gc = xfrm6_garbage_collect,
	.update_pmtu = xfrm6_update_pmtu,
	.redirect = xfrm6_redirect,
	.cow_metrics = dst_cow_metrics_generic,
	.destroy = xfrm6_dst_destroy,
	.ifdown = xfrm6_dst_ifdown,
	.local_out = __ip6_local_out,
	.gc_thresh = 32768,
	};

	static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
	.family = AF_INET6,
	.dst_ops = &xfrm6_dst_ops,
	.dst_lookup = xfrm6_dst_lookup,
	.get_saddr = xfrm6_get_saddr,
	.decode_session = _decode_session6,
	.get_tos = xfrm6_get_tos,
	.init_path = xfrm6_init_path,
	.fill_dst = xfrm6_fill_dst,
	.blackhole_route = ip6_blackhole_route,
	};

	static int __init xfrm6_policy_init(void)
	{
	return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
	}

	static void xfrm6_policy_fini(void)
	{
	xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
	}

	#ifdef CONFIG_SYSCTL
	static struct ctl_table xfrm6_policy_table[] = {
	{
	.procname = "xfrm6_gc_thresh",
	.data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
	.maxlen = sizeof(int),
	.mode = 0644,
	.proc_handler = proc_dointvec,
	},
	{ }
	};

	static int __net_init xfrm6_net_init(struct net *net)
	{
	struct ctl_table *table;
	struct ctl_table_header *hdr;

	table = xfrm6_policy_table;
	if (!net_eq(net, &init_net)) {
	table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
	if (!table)
	goto err_alloc;

	table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
	}

	hdr = register_net_sysctl(net, "net/ipv6", table);
	if (!hdr)
	goto err_reg;

	net->ipv6.sysctl.xfrm6_hdr = hdr;
	return 0;

	err_reg:
	if (!net_eq(net, &init_net))
	kfree(table);
	err_alloc:
	return -ENOMEM;
	}

	static void __net_exit xfrm6_net_exit(struct net *net)
	{
	struct ctl_table *table;

	if (!net->ipv6.sysctl.xfrm6_hdr)
	return;

	table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
	unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
	if (!net_eq(net, &init_net))
	kfree(table);
	}

	static struct pernet_operations xfrm6_net_ops = {
	.init = xfrm6_net_init,
	.exit = xfrm6_net_exit,
	};
	#endif

	int __init xfrm6_init(void)
	{
	int ret;

	dst_entries_init(&xfrm6_dst_ops);

	ret = xfrm6_policy_init();
	if (ret) {
	dst_entries_destroy(&xfrm6_dst_ops);
	goto out;
	}
	ret = xfrm6_state_init();
	if (ret)
	goto out_policy;

	ret = xfrm6_protocol_init();
	if (ret)
	goto out_state;

	#ifdef CONFIG_SYSCTL
	register_pernet_subsys(&xfrm6_net_ops);
	#endif
	out:
	return ret;
	out_state:
	xfrm6_state_fini();
	out_policy:
	xfrm6_policy_fini();
	goto out;
	}

	void xfrm6_fini(void)
	{
	#ifdef CONFIG_SYSCTL
	unregister_pernet_subsys(&xfrm6_net_ops);
	#endif
	xfrm6_protocol_fini();
	xfrm6_policy_fini();
	xfrm6_state_fini();
	dst_entries_destroy(&xfrm6_dst_ops);
	}