text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * xfrm_policy.c
   *
   * Changes:
   *	Mitsuru KANDA @USAGI
   * 	Kazunori MIYAZAWA @USAGI
   * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   * 		IPv6 support
   * 	Kazunori MIYAZAWA @USAGI
   * 	YOSHIFUJI Hideaki
   * 		Split up af-specific portion
   *	Derek Atkins <derek@ihtfp.com>		Add the post_input processor
   *
   */
  
  #include <linux/err.h>
  #include <linux/slab.h>
  #include <linux/kmod.h>
  #include <linux/list.h>
  #include <linux/spinlock.h>
  #include <linux/workqueue.h>
  #include <linux/notifier.h>
  #include <linux/netdevice.h>
  #include <linux/netfilter.h>
  #include <linux/module.h>
  #include <linux/cache.h>
  #include <linux/cpu.h>
  #include <linux/audit.h>
  #include <linux/rhashtable.h>
  #include <linux/if_tunnel.h>
  #include <net/dst.h>
  #include <net/flow.h>
  #include <net/xfrm.h>
  #include <net/ip.h>
  #if IS_ENABLED(CONFIG_IPV6_MIP6)
  #include <net/mip6.h>
  #endif
  #ifdef CONFIG_XFRM_STATISTICS
  #include <net/snmp.h>
  #endif
  #ifdef CONFIG_XFRM_ESPINTCP
  #include <net/espintcp.h>
  #endif
  
  #include "xfrm_hash.h"
  
  #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
  #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
  #define XFRM_MAX_QUEUE_LEN	100
  
  struct xfrm_flo {
  	struct dst_entry *dst_orig;
  	u8 flags;
  };
  
  /* prefixes smaller than this are stored in lists, not trees. */
  #define INEXACT_PREFIXLEN_IPV4	16
  #define INEXACT_PREFIXLEN_IPV6	48
  
  struct xfrm_pol_inexact_node {
  	struct rb_node node;
  	union {
  		xfrm_address_t addr;
  		struct rcu_head rcu;
  	};
  	u8 prefixlen;
  
  	struct rb_root root;
  
  	/* the policies matching this node, can be empty list */
  	struct hlist_head hhead;
  };
  
  /* xfrm inexact policy search tree:
   * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
   *  |
   * +---- root_d: sorted by daddr:prefix
   * |                 |
   * |        xfrm_pol_inexact_node
   * |                 |
   * |                 +- root: sorted by saddr/prefix
   * |                 |              |
   * |                 |         xfrm_pol_inexact_node
   * |                 |              |
   * |                 |              + root: unused
   * |                 |              |
   * |                 |              + hhead: saddr:daddr policies
   * |                 |
   * |                 +- coarse policies and all any:daddr policies
   * |
   * +---- root_s: sorted by saddr:prefix
   * |                 |
   * |        xfrm_pol_inexact_node
   * |                 |
   * |                 + root: unused
   * |                 |
   * |                 + hhead: saddr:any policies
   * |
   * +---- coarse policies and all any:any policies
   *
   * Lookups return four candidate lists:
   * 1. any:any list from top-level xfrm_pol_inexact_bin
   * 2. any:daddr list from daddr tree
   * 3. saddr:daddr list from 2nd level daddr tree
   * 4. saddr:any list from saddr tree
   *
   * This result set then needs to be searched for the policy with
   * the lowest priority.  If two results have same prio, youngest one wins.
   */
  
  struct xfrm_pol_inexact_key {
  	possible_net_t net;
  	u32 if_id;
  	u16 family;
  	u8 dir, type;
  };
  
  struct xfrm_pol_inexact_bin {
  	struct xfrm_pol_inexact_key k;
  	struct rhash_head head;
  	/* list containing '*:*' policies */
  	struct hlist_head hhead;
  
  	seqcount_spinlock_t count;
  	/* tree sorted by daddr/prefix */
  	struct rb_root root_d;
  
  	/* tree sorted by saddr/prefix */
  	struct rb_root root_s;
  
  	/* slow path below */
  	struct list_head inexact_bins;
  	struct rcu_head rcu;
  };
  
  enum xfrm_pol_inexact_candidate_type {
  	XFRM_POL_CAND_BOTH,
  	XFRM_POL_CAND_SADDR,
  	XFRM_POL_CAND_DADDR,
  	XFRM_POL_CAND_ANY,
  
  	XFRM_POL_CAND_MAX,
  };
  
  struct xfrm_pol_inexact_candidates {
  	struct hlist_head *res[XFRM_POL_CAND_MAX];
  };
  
  static DEFINE_SPINLOCK(xfrm_if_cb_lock);
  static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
  
  static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
  static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
  						__read_mostly;
  
  static struct kmem_cache *xfrm_dst_cache __ro_after_init;
  static __read_mostly seqcount_mutex_t xfrm_policy_hash_generation;
  
  static struct rhashtable xfrm_policy_inexact_table;
  static const struct rhashtable_params xfrm_pol_inexact_params;
  
  static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
  static int stale_bundle(struct dst_entry *dst);
  static int xfrm_bundle_ok(struct xfrm_dst *xdst);
  static void xfrm_policy_queue_process(struct timer_list *t);
  
  static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
  static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  						int dir);
  
  static struct xfrm_pol_inexact_bin *
  xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
  			   u32 if_id);
  
  static struct xfrm_pol_inexact_bin *
  xfrm_policy_inexact_lookup_rcu(struct net *net,
  			       u8 type, u16 family, u8 dir, u32 if_id);
  static struct xfrm_policy *
  xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
  			bool excl);
  static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
  					    struct xfrm_policy *policy);
  
  static bool
  xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
  				    struct xfrm_pol_inexact_bin *b,
  				    const xfrm_address_t *saddr,
  				    const xfrm_address_t *daddr);
  
  static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
  {
  	return refcount_inc_not_zero(&policy->refcnt);
  }
  
  static inline bool
  __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  {
  	const struct flowi4 *fl4 = &fl->u.ip4;
  
  	return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
  		addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
  		!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
  		!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
  		(fl4->flowi4_proto == sel->proto || !sel->proto) &&
  		(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
  }
  
  static inline bool
  __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  {
  	const struct flowi6 *fl6 = &fl->u.ip6;
  
  	return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
  		addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
  		!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
  		!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
  		(fl6->flowi6_proto == sel->proto || !sel->proto) &&
  		(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
  }
  
  bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
  			 unsigned short family)
  {
  	switch (family) {
  	case AF_INET:
  		return __xfrm4_selector_match(sel, fl);
  	case AF_INET6:
  		return __xfrm6_selector_match(sel, fl);
  	}
  	return false;
  }
  
  static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
  {
  	const struct xfrm_policy_afinfo *afinfo;
  
  	if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
  		return NULL;
  	rcu_read_lock();
  	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
  	if (unlikely(!afinfo))
  		rcu_read_unlock();
  	return afinfo;
  }
  
  /* Called with rcu_read_lock(). */
  static const struct xfrm_if_cb *xfrm_if_get_cb(void)
  {
  	return rcu_dereference(xfrm_if_cb);
  }
  
  struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
  				    const xfrm_address_t *saddr,
  				    const xfrm_address_t *daddr,
  				    int family, u32 mark)
  {
  	const struct xfrm_policy_afinfo *afinfo;
  	struct dst_entry *dst;
  
  	afinfo = xfrm_policy_get_afinfo(family);
  	if (unlikely(afinfo == NULL))
  		return ERR_PTR(-EAFNOSUPPORT);
  
  	dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
  
  	rcu_read_unlock();
  
  	return dst;
  }
  EXPORT_SYMBOL(__xfrm_dst_lookup);
  
  static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
  						int tos, int oif,
  						xfrm_address_t *prev_saddr,
  						xfrm_address_t *prev_daddr,
  						int family, u32 mark)
  {
  	struct net *net = xs_net(x);
  	xfrm_address_t *saddr = &x->props.saddr;
  	xfrm_address_t *daddr = &x->id.daddr;
  	struct dst_entry *dst;
  
  	if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
  		saddr = x->coaddr;
  		daddr = prev_daddr;
  	}
  	if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
  		saddr = prev_saddr;
  		daddr = x->coaddr;
  	}
  
  	dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
  
  	if (!IS_ERR(dst)) {
  		if (prev_saddr != saddr)
  			memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
  		if (prev_daddr != daddr)
  			memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
  	}
  
  	return dst;
  }
  
  static inline unsigned long make_jiffies(long secs)
  {
  	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
  		return MAX_SCHEDULE_TIMEOUT-1;
  	else
  		return secs*HZ;
  }
  
  static void xfrm_policy_timer(struct timer_list *t)
  {
  	struct xfrm_policy *xp = from_timer(xp, t, timer);
  	time64_t now = ktime_get_real_seconds();
  	time64_t next = TIME64_MAX;
  	int warn = 0;
  	int dir;
  
  	read_lock(&xp->lock);
  
  	if (unlikely(xp->walk.dead))
  		goto out;
  
  	dir = xfrm_policy_id2dir(xp->index);
  
  	if (xp->lft.hard_add_expires_seconds) {
  		time64_t tmo = xp->lft.hard_add_expires_seconds +
  			xp->curlft.add_time - now;
  		if (tmo <= 0)
  			goto expired;
  		if (tmo < next)
  			next = tmo;
  	}
  	if (xp->lft.hard_use_expires_seconds) {
  		time64_t tmo = xp->lft.hard_use_expires_seconds +
  			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
  		if (tmo <= 0)
  			goto expired;
  		if (tmo < next)
  			next = tmo;
  	}
  	if (xp->lft.soft_add_expires_seconds) {
  		time64_t tmo = xp->lft.soft_add_expires_seconds +
  			xp->curlft.add_time - now;
  		if (tmo <= 0) {
  			warn = 1;
  			tmo = XFRM_KM_TIMEOUT;
  		}
  		if (tmo < next)
  			next = tmo;
  	}
  	if (xp->lft.soft_use_expires_seconds) {
  		time64_t tmo = xp->lft.soft_use_expires_seconds +
  			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
  		if (tmo <= 0) {
  			warn = 1;
  			tmo = XFRM_KM_TIMEOUT;
  		}
  		if (tmo < next)
  			next = tmo;
  	}
  
  	if (warn)
  		km_policy_expired(xp, dir, 0, 0);
  	if (next != TIME64_MAX &&
  	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
  		xfrm_pol_hold(xp);
  
  out:
  	read_unlock(&xp->lock);
  	xfrm_pol_put(xp);
  	return;
  
  expired:
  	read_unlock(&xp->lock);
  	if (!xfrm_policy_delete(xp, dir))
  		km_policy_expired(xp, dir, 1, 0);
  	xfrm_pol_put(xp);
  }
  
  /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
   * SPD calls.
   */
  
  struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
  {
  	struct xfrm_policy *policy;
  
  	policy = kzalloc(sizeof(struct xfrm_policy), gfp);
  
  	if (policy) {
  		write_pnet(&policy->xp_net, net);
  		INIT_LIST_HEAD(&policy->walk.all);
  		INIT_HLIST_NODE(&policy->bydst_inexact_list);
  		INIT_HLIST_NODE(&policy->bydst);
  		INIT_HLIST_NODE(&policy->byidx);
  		rwlock_init(&policy->lock);
  		refcount_set(&policy->refcnt, 1);
  		skb_queue_head_init(&policy->polq.hold_queue);
  		timer_setup(&policy->timer, xfrm_policy_timer, 0);
  		timer_setup(&policy->polq.hold_timer,
  			    xfrm_policy_queue_process, 0);
  	}
  	return policy;
  }
  EXPORT_SYMBOL(xfrm_policy_alloc);
  
  static void xfrm_policy_destroy_rcu(struct rcu_head *head)
  {
  	struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
  
  	security_xfrm_policy_free(policy->security);
  	kfree(policy);
  }
  
  /* Destroy xfrm_policy: descendant resources must be released to this moment. */
  
  void xfrm_policy_destroy(struct xfrm_policy *policy)
  {
  	BUG_ON(!policy->walk.dead);
  
  	if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
  		BUG();
  
  	call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
  }
  EXPORT_SYMBOL(xfrm_policy_destroy);
  
  /* Rule must be locked. Release descendant resources, announce
   * entry dead. The rule must be unlinked from lists to the moment.
   */
  
  static void xfrm_policy_kill(struct xfrm_policy *policy)
  {
  	write_lock_bh(&policy->lock);
  	policy->walk.dead = 1;
  	write_unlock_bh(&policy->lock);
  
  	atomic_inc(&policy->genid);
  
  	if (del_timer(&policy->polq.hold_timer))
  		xfrm_pol_put(policy);
  	skb_queue_purge(&policy->polq.hold_queue);
  
  	if (del_timer(&policy->timer))
  		xfrm_pol_put(policy);
  
  	xfrm_pol_put(policy);
  }
  
  static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
  
  static inline unsigned int idx_hash(struct net *net, u32 index)
  {
  	return __idx_hash(index, net->xfrm.policy_idx_hmask);
  }
  
  /* calculate policy hash thresholds */
  static void __get_hash_thresh(struct net *net,
  			      unsigned short family, int dir,
  			      u8 *dbits, u8 *sbits)
  {
  	switch (family) {
  	case AF_INET:
  		*dbits = net->xfrm.policy_bydst[dir].dbits4;
  		*sbits = net->xfrm.policy_bydst[dir].sbits4;
  		break;
  
  	case AF_INET6:
  		*dbits = net->xfrm.policy_bydst[dir].dbits6;
  		*sbits = net->xfrm.policy_bydst[dir].sbits6;
  		break;
  
  	default:
  		*dbits = 0;
  		*sbits = 0;
  	}
  }
  
  static struct hlist_head *policy_hash_bysel(struct net *net,
  					    const struct xfrm_selector *sel,
  					    unsigned short family, int dir)
  {
  	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
  	unsigned int hash;
  	u8 dbits;
  	u8 sbits;
  
  	__get_hash_thresh(net, family, dir, &dbits, &sbits);
  	hash = __sel_hash(sel, family, hmask, dbits, sbits);
  
  	if (hash == hmask + 1)
  		return NULL;
  
  	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
  		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
  }
  
  static struct hlist_head *policy_hash_direct(struct net *net,
  					     const xfrm_address_t *daddr,
  					     const xfrm_address_t *saddr,
  					     unsigned short family, int dir)
  {
  	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
  	unsigned int hash;
  	u8 dbits;
  	u8 sbits;
  
  	__get_hash_thresh(net, family, dir, &dbits, &sbits);
  	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
  
  	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
  		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
  }
  
  static void xfrm_dst_hash_transfer(struct net *net,
  				   struct hlist_head *list,
  				   struct hlist_head *ndsttable,
  				   unsigned int nhashmask,
  				   int dir)
  {
  	struct hlist_node *tmp, *entry0 = NULL;
  	struct xfrm_policy *pol;
  	unsigned int h0 = 0;
  	u8 dbits;
  	u8 sbits;
  
  redo:
  	hlist_for_each_entry_safe(pol, tmp, list, bydst) {
  		unsigned int h;
  
  		__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
  		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
  				pol->family, nhashmask, dbits, sbits);
  		if (!entry0) {
  			hlist_del_rcu(&pol->bydst);
  			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
  			h0 = h;
  		} else {
  			if (h != h0)
  				continue;
  			hlist_del_rcu(&pol->bydst);
  			hlist_add_behind_rcu(&pol->bydst, entry0);
  		}
  		entry0 = &pol->bydst;
  	}
  	if (!hlist_empty(list)) {
  		entry0 = NULL;
  		goto redo;
  	}
  }
  
  static void xfrm_idx_hash_transfer(struct hlist_head *list,
  				   struct hlist_head *nidxtable,
  				   unsigned int nhashmask)
  {
  	struct hlist_node *tmp;
  	struct xfrm_policy *pol;
  
  	hlist_for_each_entry_safe(pol, tmp, list, byidx) {
  		unsigned int h;
  
  		h = __idx_hash(pol->index, nhashmask);
  		hlist_add_head(&pol->byidx, nidxtable+h);
  	}
  }
  
  static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
  {
  	return ((old_hmask + 1) << 1) - 1;
  }
  
  static void xfrm_bydst_resize(struct net *net, int dir)
  {
  	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
  	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
  	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
  	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
  	struct hlist_head *odst;
  	int i;
  
  	if (!ndst)
  		return;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	write_seqcount_begin(&xfrm_policy_hash_generation);
  
  	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
  				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
  
  	for (i = hmask; i >= 0; i--)
  		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
  
  	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
  	net->xfrm.policy_bydst[dir].hmask = nhashmask;
  
  	write_seqcount_end(&xfrm_policy_hash_generation);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	synchronize_rcu();
  
  	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
  }
  
  static void xfrm_byidx_resize(struct net *net, int total)
  {
  	unsigned int hmask = net->xfrm.policy_idx_hmask;
  	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
  	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
  	struct hlist_head *oidx = net->xfrm.policy_byidx;
  	struct hlist_head *nidx = xfrm_hash_alloc(nsize);
  	int i;
  
  	if (!nidx)
  		return;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  
  	for (i = hmask; i >= 0; i--)
  		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
  
  	net->xfrm.policy_byidx = nidx;
  	net->xfrm.policy_idx_hmask = nhashmask;
  
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
  }
  
  static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
  {
  	unsigned int cnt = net->xfrm.policy_count[dir];
  	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
  
  	if (total)
  		*total += cnt;
  
  	if ((hmask + 1) < xfrm_policy_hashmax &&
  	    cnt > hmask)
  		return 1;
  
  	return 0;
  }
  
  static inline int xfrm_byidx_should_resize(struct net *net, int total)
  {
  	unsigned int hmask = net->xfrm.policy_idx_hmask;
  
  	if ((hmask + 1) < xfrm_policy_hashmax &&
  	    total > hmask)
  		return 1;
  
  	return 0;
  }
  
  void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
  {
  	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
  	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
  	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
  	si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
  	si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
  	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
  	si->spdhcnt = net->xfrm.policy_idx_hmask;
  	si->spdhmcnt = xfrm_policy_hashmax;
  }
  EXPORT_SYMBOL(xfrm_spd_getinfo);
  
  static DEFINE_MUTEX(hash_resize_mutex);
  static void xfrm_hash_resize(struct work_struct *work)
  {
  	struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
  	int dir, total;
  
  	mutex_lock(&hash_resize_mutex);
  
  	total = 0;
  	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
  		if (xfrm_bydst_should_resize(net, dir, &total))
  			xfrm_bydst_resize(net, dir);
  	}
  	if (xfrm_byidx_should_resize(net, total))
  		xfrm_byidx_resize(net, total);
  
  	mutex_unlock(&hash_resize_mutex);
  }
  
  /* Make sure *pol can be inserted into fastbin.
   * Useful to check that later insert requests will be sucessful
   * (provided xfrm_policy_lock is held throughout).
   */
  static struct xfrm_pol_inexact_bin *
  xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
  {
  	struct xfrm_pol_inexact_bin *bin, *prev;
  	struct xfrm_pol_inexact_key k = {
  		.family = pol->family,
  		.type = pol->type,
  		.dir = dir,
  		.if_id = pol->if_id,
  	};
  	struct net *net = xp_net(pol);
  
  	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
  
  	write_pnet(&k.net, net);
  	bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
  				     xfrm_pol_inexact_params);
  	if (bin)
  		return bin;
  
  	bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
  	if (!bin)
  		return NULL;
  
  	bin->k = k;
  	INIT_HLIST_HEAD(&bin->hhead);
  	bin->root_d = RB_ROOT;
  	bin->root_s = RB_ROOT;
  	seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
  
  	prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
  						&bin->k, &bin->head,
  						xfrm_pol_inexact_params);
  	if (!prev) {
  		list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
  		return bin;
  	}
  
  	kfree(bin);
  
  	return IS_ERR(prev) ? NULL : prev;
  }
  
  static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
  					       int family, u8 prefixlen)
  {
  	if (xfrm_addr_any(addr, family))
  		return true;
  
  	if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
  		return true;
  
  	if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
  		return true;
  
  	return false;
  }
  
  static bool
  xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
  {
  	const xfrm_address_t *addr;
  	bool saddr_any, daddr_any;
  	u8 prefixlen;
  
  	addr = &policy->selector.saddr;
  	prefixlen = policy->selector.prefixlen_s;
  
  	saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
  						       policy->family,
  						       prefixlen);
  	addr = &policy->selector.daddr;
  	prefixlen = policy->selector.prefixlen_d;
  	daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
  						       policy->family,
  						       prefixlen);
  	return saddr_any && daddr_any;
  }
  
  static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
  				       const xfrm_address_t *addr, u8 prefixlen)
  {
  	node->addr = *addr;
  	node->prefixlen = prefixlen;
  }
  
  static struct xfrm_pol_inexact_node *
  xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
  {
  	struct xfrm_pol_inexact_node *node;
  
  	node = kzalloc(sizeof(*node), GFP_ATOMIC);
  	if (node)
  		xfrm_pol_inexact_node_init(node, addr, prefixlen);
  
  	return node;
  }
  
  static int xfrm_policy_addr_delta(const xfrm_address_t *a,
  				  const xfrm_address_t *b,
  				  u8 prefixlen, u16 family)
  {
  	u32 ma, mb, mask;
  	unsigned int pdw, pbi;
  	int delta = 0;
  
  	switch (family) {
  	case AF_INET:
  		if (prefixlen == 0)
  			return 0;
  		mask = ~0U << (32 - prefixlen);
  		ma = ntohl(a->a4) & mask;
  		mb = ntohl(b->a4) & mask;
  		if (ma < mb)
  			delta = -1;
  		else if (ma > mb)
  			delta = 1;
  		break;
  	case AF_INET6:
  		pdw = prefixlen >> 5;
  		pbi = prefixlen & 0x1f;
  
  		if (pdw) {
  			delta = memcmp(a->a6, b->a6, pdw << 2);
  			if (delta)
  				return delta;
  		}
  		if (pbi) {
  			mask = ~0U << (32 - pbi);
  			ma = ntohl(a->a6[pdw]) & mask;
  			mb = ntohl(b->a6[pdw]) & mask;
  			if (ma < mb)
  				delta = -1;
  			else if (ma > mb)
  				delta = 1;
  		}
  		break;
  	default:
  		break;
  	}
  
  	return delta;
  }
  
  static void xfrm_policy_inexact_list_reinsert(struct net *net,
  					      struct xfrm_pol_inexact_node *n,
  					      u16 family)
  {
  	unsigned int matched_s, matched_d;
  	struct xfrm_policy *policy, *p;
  
  	matched_s = 0;
  	matched_d = 0;
  
  	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
  		struct hlist_node *newpos = NULL;
  		bool matches_s, matches_d;
  
  		if (!policy->bydst_reinsert)
  			continue;
  
  		WARN_ON_ONCE(policy->family != family);
  
  		policy->bydst_reinsert = false;
  		hlist_for_each_entry(p, &n->hhead, bydst) {
  			if (policy->priority > p->priority)
  				newpos = &p->bydst;
  			else if (policy->priority == p->priority &&
  				 policy->pos > p->pos)
  				newpos = &p->bydst;
  			else
  				break;
  		}
  
  		if (newpos)
  			hlist_add_behind_rcu(&policy->bydst, newpos);
  		else
  			hlist_add_head_rcu(&policy->bydst, &n->hhead);
  
  		/* paranoia checks follow.
  		 * Check that the reinserted policy matches at least
  		 * saddr or daddr for current node prefix.
  		 *
  		 * Matching both is fine, matching saddr in one policy
  		 * (but not daddr) and then matching only daddr in another
  		 * is a bug.
  		 */
  		matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
  						   &n->addr,
  						   n->prefixlen,
  						   family) == 0;
  		matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
  						   &n->addr,
  						   n->prefixlen,
  						   family) == 0;
  		if (matches_s && matches_d)
  			continue;
  
  		WARN_ON_ONCE(!matches_s && !matches_d);
  		if (matches_s)
  			matched_s++;
  		if (matches_d)
  			matched_d++;
  		WARN_ON_ONCE(matched_s && matched_d);
  	}
  }
  
  static void xfrm_policy_inexact_node_reinsert(struct net *net,
  					      struct xfrm_pol_inexact_node *n,
  					      struct rb_root *new,
  					      u16 family)
  {
  	struct xfrm_pol_inexact_node *node;
  	struct rb_node **p, *parent;
  
  	/* we should not have another subtree here */
  	WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
  restart:
  	parent = NULL;
  	p = &new->rb_node;
  	while (*p) {
  		u8 prefixlen;
  		int delta;
  
  		parent = *p;
  		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
  
  		prefixlen = min(node->prefixlen, n->prefixlen);
  
  		delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
  					       prefixlen, family);
  		if (delta < 0) {
  			p = &parent->rb_left;
  		} else if (delta > 0) {
  			p = &parent->rb_right;
  		} else {
  			bool same_prefixlen = node->prefixlen == n->prefixlen;
  			struct xfrm_policy *tmp;
  
  			hlist_for_each_entry(tmp, &n->hhead, bydst) {
  				tmp->bydst_reinsert = true;
  				hlist_del_rcu(&tmp->bydst);
  			}
  
  			node->prefixlen = prefixlen;
  
  			xfrm_policy_inexact_list_reinsert(net, node, family);
  
  			if (same_prefixlen) {
  				kfree_rcu(n, rcu);
  				return;
  			}
  
  			rb_erase(*p, new);
  			kfree_rcu(n, rcu);
  			n = node;
  			goto restart;
  		}
  	}
  
  	rb_link_node_rcu(&n->node, parent, p);
  	rb_insert_color(&n->node, new);
  }
  
  /* merge nodes v and n */
  static void xfrm_policy_inexact_node_merge(struct net *net,
  					   struct xfrm_pol_inexact_node *v,
  					   struct xfrm_pol_inexact_node *n,
  					   u16 family)
  {
  	struct xfrm_pol_inexact_node *node;
  	struct xfrm_policy *tmp;
  	struct rb_node *rnode;
  
  	/* To-be-merged node v has a subtree.
  	 *
  	 * Dismantle it and insert its nodes to n->root.
  	 */
  	while ((rnode = rb_first(&v->root)) != NULL) {
  		node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
  		rb_erase(&node->node, &v->root);
  		xfrm_policy_inexact_node_reinsert(net, node, &n->root,
  						  family);
  	}
  
  	hlist_for_each_entry(tmp, &v->hhead, bydst) {
  		tmp->bydst_reinsert = true;
  		hlist_del_rcu(&tmp->bydst);
  	}
  
  	xfrm_policy_inexact_list_reinsert(net, n, family);
  }
  
  static struct xfrm_pol_inexact_node *
  xfrm_policy_inexact_insert_node(struct net *net,
  				struct rb_root *root,
  				xfrm_address_t *addr,
  				u16 family, u8 prefixlen, u8 dir)
  {
  	struct xfrm_pol_inexact_node *cached = NULL;
  	struct rb_node **p, *parent = NULL;
  	struct xfrm_pol_inexact_node *node;
  
  	p = &root->rb_node;
  	while (*p) {
  		int delta;
  
  		parent = *p;
  		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
  
  		delta = xfrm_policy_addr_delta(addr, &node->addr,
  					       node->prefixlen,
  					       family);
  		if (delta == 0 && prefixlen >= node->prefixlen) {
  			WARN_ON_ONCE(cached); /* ipsec policies got lost */
  			return node;
  		}
  
  		if (delta < 0)
  			p = &parent->rb_left;
  		else
  			p = &parent->rb_right;
  
  		if (prefixlen < node->prefixlen) {
  			delta = xfrm_policy_addr_delta(addr, &node->addr,
  						       prefixlen,
  						       family);
  			if (delta)
  				continue;
  
  			/* This node is a subnet of the new prefix. It needs
  			 * to be removed and re-inserted with the smaller
  			 * prefix and all nodes that are now also covered
  			 * by the reduced prefixlen.
  			 */
  			rb_erase(&node->node, root);
  
  			if (!cached) {
  				xfrm_pol_inexact_node_init(node, addr,
  							   prefixlen);
  				cached = node;
  			} else {
  				/* This node also falls within the new
  				 * prefixlen. Merge the to-be-reinserted
  				 * node and this one.
  				 */
  				xfrm_policy_inexact_node_merge(net, node,
  							       cached, family);
  				kfree_rcu(node, rcu);
  			}
  
  			/* restart */
  			p = &root->rb_node;
  			parent = NULL;
  		}
  	}
  
  	node = cached;
  	if (!node) {
  		node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
  		if (!node)
  			return NULL;
  	}
  
  	rb_link_node_rcu(&node->node, parent, p);
  	rb_insert_color(&node->node, root);
  
  	return node;
  }
  
  static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
  {
  	struct xfrm_pol_inexact_node *node;
  	struct rb_node *rn = rb_first(r);
  
  	while (rn) {
  		node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
  
  		xfrm_policy_inexact_gc_tree(&node->root, rm);
  		rn = rb_next(rn);
  
  		if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
  			WARN_ON_ONCE(rm);
  			continue;
  		}
  
  		rb_erase(&node->node, r);
  		kfree_rcu(node, rcu);
  	}
  }
  
  static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
  {
  	write_seqcount_begin(&b->count);
  	xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
  	xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
  	write_seqcount_end(&b->count);
  
  	if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
  	    !hlist_empty(&b->hhead)) {
  		WARN_ON_ONCE(net_exit);
  		return;
  	}
  
  	if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
  				   xfrm_pol_inexact_params) == 0) {
  		list_del(&b->inexact_bins);
  		kfree_rcu(b, rcu);
  	}
  }
  
  static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
  {
  	struct net *net = read_pnet(&b->k.net);
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	__xfrm_policy_inexact_prune_bin(b, false);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  }
  
  static void __xfrm_policy_inexact_flush(struct net *net)
  {
  	struct xfrm_pol_inexact_bin *bin, *t;
  
  	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
  
  	list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
  		__xfrm_policy_inexact_prune_bin(bin, false);
  }
  
  static struct hlist_head *
  xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
  				struct xfrm_policy *policy, u8 dir)
  {
  	struct xfrm_pol_inexact_node *n;
  	struct net *net;
  
  	net = xp_net(policy);
  	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
  
  	if (xfrm_policy_inexact_insert_use_any_list(policy))
  		return &bin->hhead;
  
  	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
  					       policy->family,
  					       policy->selector.prefixlen_d)) {
  		write_seqcount_begin(&bin->count);
  		n = xfrm_policy_inexact_insert_node(net,
  						    &bin->root_s,
  						    &policy->selector.saddr,
  						    policy->family,
  						    policy->selector.prefixlen_s,
  						    dir);
  		write_seqcount_end(&bin->count);
  		if (!n)
  			return NULL;
  
  		return &n->hhead;
  	}
  
  	/* daddr is fixed */
  	write_seqcount_begin(&bin->count);
  	n = xfrm_policy_inexact_insert_node(net,
  					    &bin->root_d,
  					    &policy->selector.daddr,
  					    policy->family,
  					    policy->selector.prefixlen_d, dir);
  	write_seqcount_end(&bin->count);
  	if (!n)
  		return NULL;
  
  	/* saddr is wildcard */
  	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
  					       policy->family,
  					       policy->selector.prefixlen_s))
  		return &n->hhead;
  
  	write_seqcount_begin(&bin->count);
  	n = xfrm_policy_inexact_insert_node(net,
  					    &n->root,
  					    &policy->selector.saddr,
  					    policy->family,
  					    policy->selector.prefixlen_s, dir);
  	write_seqcount_end(&bin->count);
  	if (!n)
  		return NULL;
  
  	return &n->hhead;
  }
  
  static struct xfrm_policy *
  xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
  {
  	struct xfrm_pol_inexact_bin *bin;
  	struct xfrm_policy *delpol;
  	struct hlist_head *chain;
  	struct net *net;
  
  	bin = xfrm_policy_inexact_alloc_bin(policy, dir);
  	if (!bin)
  		return ERR_PTR(-ENOMEM);
  
  	net = xp_net(policy);
  	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
  
  	chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
  	if (!chain) {
  		__xfrm_policy_inexact_prune_bin(bin, false);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	delpol = xfrm_policy_insert_list(chain, policy, excl);
  	if (delpol && excl) {
  		__xfrm_policy_inexact_prune_bin(bin, false);
  		return ERR_PTR(-EEXIST);
  	}
  
  	chain = &net->xfrm.policy_inexact[dir];
  	xfrm_policy_insert_inexact_list(chain, policy);
  
  	if (delpol)
  		__xfrm_policy_inexact_prune_bin(bin, false);
  
  	return delpol;
  }
  
  static void xfrm_hash_rebuild(struct work_struct *work)
  {
  	struct net *net = container_of(work, struct net,
  				       xfrm.policy_hthresh.work);
  	unsigned int hmask;
  	struct xfrm_policy *pol;
  	struct xfrm_policy *policy;
  	struct hlist_head *chain;
  	struct hlist_head *odst;
  	struct hlist_node *newpos;
  	int i;
  	int dir;
  	unsigned seq;
  	u8 lbits4, rbits4, lbits6, rbits6;
  
  	mutex_lock(&hash_resize_mutex);
  
  	/* read selector prefixlen thresholds */
  	do {
  		seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
  
  		lbits4 = net->xfrm.policy_hthresh.lbits4;
  		rbits4 = net->xfrm.policy_hthresh.rbits4;
  		lbits6 = net->xfrm.policy_hthresh.lbits6;
  		rbits6 = net->xfrm.policy_hthresh.rbits6;
  	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	write_seqcount_begin(&xfrm_policy_hash_generation);
  
  	/* make sure that we can insert the indirect policies again before
  	 * we start with destructive action.
  	 */
  	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
  		struct xfrm_pol_inexact_bin *bin;
  		u8 dbits, sbits;
  
  		dir = xfrm_policy_id2dir(policy->index);
  		if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
  			continue;
  
  		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
  			if (policy->family == AF_INET) {
  				dbits = rbits4;
  				sbits = lbits4;
  			} else {
  				dbits = rbits6;
  				sbits = lbits6;
  			}
  		} else {
  			if (policy->family == AF_INET) {
  				dbits = lbits4;
  				sbits = rbits4;
  			} else {
  				dbits = lbits6;
  				sbits = rbits6;
  			}
  		}
  
  		if (policy->selector.prefixlen_d < dbits ||
  		    policy->selector.prefixlen_s < sbits)
  			continue;
  
  		bin = xfrm_policy_inexact_alloc_bin(policy, dir);
  		if (!bin)
  			goto out_unlock;
  
  		if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
  			goto out_unlock;
  	}
  
  	/* reset the bydst and inexact table in all directions */
  	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
  		struct hlist_node *n;
  
  		hlist_for_each_entry_safe(policy, n,
  					  &net->xfrm.policy_inexact[dir],
  					  bydst_inexact_list) {
  			hlist_del_rcu(&policy->bydst);
  			hlist_del_init(&policy->bydst_inexact_list);
  		}
  
  		hmask = net->xfrm.policy_bydst[dir].hmask;
  		odst = net->xfrm.policy_bydst[dir].table;
  		for (i = hmask; i >= 0; i--) {
  			hlist_for_each_entry_safe(policy, n, odst + i, bydst)
  				hlist_del_rcu(&policy->bydst);
  		}
  		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
  			/* dir out => dst = remote, src = local */
  			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
  			net->xfrm.policy_bydst[dir].sbits4 = lbits4;
  			net->xfrm.policy_bydst[dir].dbits6 = rbits6;
  			net->xfrm.policy_bydst[dir].sbits6 = lbits6;
  		} else {
  			/* dir in/fwd => dst = local, src = remote */
  			net->xfrm.policy_bydst[dir].dbits4 = lbits4;
  			net->xfrm.policy_bydst[dir].sbits4 = rbits4;
  			net->xfrm.policy_bydst[dir].dbits6 = lbits6;
  			net->xfrm.policy_bydst[dir].sbits6 = rbits6;
  		}
  	}
  
  	/* re-insert all policies by order of creation */
  	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
  		if (policy->walk.dead)
  			continue;
  		dir = xfrm_policy_id2dir(policy->index);
  		if (dir >= XFRM_POLICY_MAX) {
  			/* skip socket policies */
  			continue;
  		}
  		newpos = NULL;
  		chain = policy_hash_bysel(net, &policy->selector,
  					  policy->family, dir);
  
  		if (!chain) {
  			void *p = xfrm_policy_inexact_insert(policy, dir, 0);
  
  			WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
  			continue;
  		}
  
  		hlist_for_each_entry(pol, chain, bydst) {
  			if (policy->priority >= pol->priority)
  				newpos = &pol->bydst;
  			else
  				break;
  		}
  		if (newpos)
  			hlist_add_behind_rcu(&policy->bydst, newpos);
  		else
  			hlist_add_head_rcu(&policy->bydst, chain);
  	}
  
  out_unlock:
  	__xfrm_policy_inexact_flush(net);
  	write_seqcount_end(&xfrm_policy_hash_generation);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	mutex_unlock(&hash_resize_mutex);
  }
  
  void xfrm_policy_hash_rebuild(struct net *net)
  {
  	schedule_work(&net->xfrm.policy_hthresh.work);
  }
  EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
  
  /* Generate new index... KAME seems to generate them ordered by cost
   * of an absolute inpredictability of ordering of rules. This will not pass. */
  static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
  {
  	static u32 idx_generator;
  
  	for (;;) {
  		struct hlist_head *list;
  		struct xfrm_policy *p;
  		u32 idx;
  		int found;
  
  		if (!index) {
  			idx = (idx_generator | dir);
  			idx_generator += 8;
  		} else {
  			idx = index;
  			index = 0;
  		}
  
  		if (idx == 0)
  			idx = 8;
  		list = net->xfrm.policy_byidx + idx_hash(net, idx);
  		found = 0;
  		hlist_for_each_entry(p, list, byidx) {
  			if (p->index == idx) {
  				found = 1;
  				break;
  			}
  		}
  		if (!found)
  			return idx;
  	}
  }
  
  static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
  {
  	u32 *p1 = (u32 *) s1;
  	u32 *p2 = (u32 *) s2;
  	int len = sizeof(struct xfrm_selector) / sizeof(u32);
  	int i;
  
  	for (i = 0; i < len; i++) {
  		if (p1[i] != p2[i])
  			return 1;
  	}
  
  	return 0;
  }
  
  static void xfrm_policy_requeue(struct xfrm_policy *old,
  				struct xfrm_policy *new)
  {
  	struct xfrm_policy_queue *pq = &old->polq;
  	struct sk_buff_head list;
  
  	if (skb_queue_empty(&pq->hold_queue))
  		return;
  
  	__skb_queue_head_init(&list);
  
  	spin_lock_bh(&pq->hold_queue.lock);
  	skb_queue_splice_init(&pq->hold_queue, &list);
  	if (del_timer(&pq->hold_timer))
  		xfrm_pol_put(old);
  	spin_unlock_bh(&pq->hold_queue.lock);
  
  	pq = &new->polq;
  
  	spin_lock_bh(&pq->hold_queue.lock);
  	skb_queue_splice(&list, &pq->hold_queue);
  	pq->timeout = XFRM_QUEUE_TMO_MIN;
  	if (!mod_timer(&pq->hold_timer, jiffies))
  		xfrm_pol_hold(new);
  	spin_unlock_bh(&pq->hold_queue.lock);
  }
  
  static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark,
  					  struct xfrm_policy *pol)
  {
  	return mark->v == pol->mark.v && mark->m == pol->mark.m;
  }
  
  static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
  {
  	const struct xfrm_pol_inexact_key *k = data;
  	u32 a = k->type << 24 | k->dir << 16 | k->family;
  
  	return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
  			    seed);
  }
  
  static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
  {
  	const struct xfrm_pol_inexact_bin *b = data;
  
  	return xfrm_pol_bin_key(&b->k, 0, seed);
  }
  
  static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
  			    const void *ptr)
  {
  	const struct xfrm_pol_inexact_key *key = arg->key;
  	const struct xfrm_pol_inexact_bin *b = ptr;
  	int ret;
  
  	if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
  		return -1;
  
  	ret = b->k.dir ^ key->dir;
  	if (ret)
  		return ret;
  
  	ret = b->k.type ^ key->type;
  	if (ret)
  		return ret;
  
  	ret = b->k.family ^ key->family;
  	if (ret)
  		return ret;
  
  	return b->k.if_id ^ key->if_id;
  }
  
  static const struct rhashtable_params xfrm_pol_inexact_params = {
  	.head_offset		= offsetof(struct xfrm_pol_inexact_bin, head),
  	.hashfn			= xfrm_pol_bin_key,
  	.obj_hashfn		= xfrm_pol_bin_obj,
  	.obj_cmpfn		= xfrm_pol_bin_cmp,
  	.automatic_shrinking	= true,
  };
  
  static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
  					    struct xfrm_policy *policy)
  {
  	struct xfrm_policy *pol, *delpol = NULL;
  	struct hlist_node *newpos = NULL;
  	int i = 0;
  
  	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
  		if (pol->type == policy->type &&
  		    pol->if_id == policy->if_id &&
  		    !selector_cmp(&pol->selector, &policy->selector) &&
  		    xfrm_policy_mark_match(&policy->mark, pol) &&
  		    xfrm_sec_ctx_match(pol->security, policy->security) &&
  		    !WARN_ON(delpol)) {
  			delpol = pol;
  			if (policy->priority > pol->priority)
  				continue;
  		} else if (policy->priority >= pol->priority) {
  			newpos = &pol->bydst_inexact_list;
  			continue;
  		}
  		if (delpol)
  			break;
  	}
  
  	if (newpos)
  		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
  	else
  		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
  
  	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
  		pol->pos = i;
  		i++;
  	}
  }
  
  static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
  						   struct xfrm_policy *policy,
  						   bool excl)
  {
  	struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
  
  	hlist_for_each_entry(pol, chain, bydst) {
  		if (pol->type == policy->type &&
  		    pol->if_id == policy->if_id &&
  		    !selector_cmp(&pol->selector, &policy->selector) &&
  		    xfrm_policy_mark_match(&policy->mark, pol) &&
  		    xfrm_sec_ctx_match(pol->security, policy->security) &&
  		    !WARN_ON(delpol)) {
  			if (excl)
  				return ERR_PTR(-EEXIST);
  			delpol = pol;
  			if (policy->priority > pol->priority)
  				continue;
  		} else if (policy->priority >= pol->priority) {
  			newpos = pol;
  			continue;
  		}
  		if (delpol)
  			break;
  	}
  
  	if (newpos)
  		hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
  	else
  		hlist_add_head_rcu(&policy->bydst, chain);
  
  	return delpol;
  }
  
  int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
  {
  	struct net *net = xp_net(policy);
  	struct xfrm_policy *delpol;
  	struct hlist_head *chain;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
  	if (chain)
  		delpol = xfrm_policy_insert_list(chain, policy, excl);
  	else
  		delpol = xfrm_policy_inexact_insert(policy, dir, excl);
  
  	if (IS_ERR(delpol)) {
  		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  		return PTR_ERR(delpol);
  	}
  
  	__xfrm_policy_link(policy, dir);
  
  	/* After previous checking, family can either be AF_INET or AF_INET6 */
  	if (policy->family == AF_INET)
  		rt_genid_bump_ipv4(net);
  	else
  		rt_genid_bump_ipv6(net);
  
  	if (delpol) {
  		xfrm_policy_requeue(delpol, policy);
  		__xfrm_policy_unlink(delpol, dir);
  	}
  	policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
  	hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
  	policy->curlft.add_time = ktime_get_real_seconds();
  	policy->curlft.use_time = 0;
  	if (!mod_timer(&policy->timer, jiffies + HZ))
  		xfrm_pol_hold(policy);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	if (delpol)
  		xfrm_policy_kill(delpol);
  	else if (xfrm_bydst_should_resize(net, dir, NULL))
  		schedule_work(&net->xfrm.policy_hash_work);
  
  	return 0;
  }
  EXPORT_SYMBOL(xfrm_policy_insert);
  
  static struct xfrm_policy *
  __xfrm_policy_bysel_ctx(struct hlist_head *chain, const struct xfrm_mark *mark,
  			u32 if_id, u8 type, int dir, struct xfrm_selector *sel,
  			struct xfrm_sec_ctx *ctx)
  {
  	struct xfrm_policy *pol;
  
  	if (!chain)
  		return NULL;
  
  	hlist_for_each_entry(pol, chain, bydst) {
  		if (pol->type == type &&
  		    pol->if_id == if_id &&
  		    xfrm_policy_mark_match(mark, pol) &&
  		    !selector_cmp(sel, &pol->selector) &&
  		    xfrm_sec_ctx_match(ctx, pol->security))
  			return pol;
  	}
  
  	return NULL;
  }
  
  struct xfrm_policy *
  xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id,
  		      u8 type, int dir, struct xfrm_selector *sel,
  		      struct xfrm_sec_ctx *ctx, int delete, int *err)
  {
  	struct xfrm_pol_inexact_bin *bin = NULL;
  	struct xfrm_policy *pol, *ret = NULL;
  	struct hlist_head *chain;
  
  	*err = 0;
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	chain = policy_hash_bysel(net, sel, sel->family, dir);
  	if (!chain) {
  		struct xfrm_pol_inexact_candidates cand;
  		int i;
  
  		bin = xfrm_policy_inexact_lookup(net, type,
  						 sel->family, dir, if_id);
  		if (!bin) {
  			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  			return NULL;
  		}
  
  		if (!xfrm_policy_find_inexact_candidates(&cand, bin,
  							 &sel->saddr,
  							 &sel->daddr)) {
  			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  			return NULL;
  		}
  
  		pol = NULL;
  		for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
  			struct xfrm_policy *tmp;
  
  			tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
  						      if_id, type, dir,
  						      sel, ctx);
  			if (!tmp)
  				continue;
  
  			if (!pol || tmp->pos < pol->pos)
  				pol = tmp;
  		}
  	} else {
  		pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
  					      sel, ctx);
  	}
  
  	if (pol) {
  		xfrm_pol_hold(pol);
  		if (delete) {
  			*err = security_xfrm_policy_delete(pol->security);
  			if (*err) {
  				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  				return pol;
  			}
  			__xfrm_policy_unlink(pol, dir);
  		}
  		ret = pol;
  	}
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	if (ret && delete)
  		xfrm_policy_kill(ret);
  	if (bin && delete)
  		xfrm_policy_inexact_prune_bin(bin);
  	return ret;
  }
  EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
  
  struct xfrm_policy *
  xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id,
  		 u8 type, int dir, u32 id, int delete, int *err)
  {
  	struct xfrm_policy *pol, *ret;
  	struct hlist_head *chain;
  
  	*err = -ENOENT;
  	if (xfrm_policy_id2dir(id) != dir)
  		return NULL;
  
  	*err = 0;
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	chain = net->xfrm.policy_byidx + idx_hash(net, id);
  	ret = NULL;
  	hlist_for_each_entry(pol, chain, byidx) {
  		if (pol->type == type && pol->index == id &&
  		    pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) {
  			xfrm_pol_hold(pol);
  			if (delete) {
  				*err = security_xfrm_policy_delete(
  								pol->security);
  				if (*err) {
  					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  					return pol;
  				}
  				__xfrm_policy_unlink(pol, dir);
  			}
  			ret = pol;
  			break;
  		}
  	}
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	if (ret && delete)
  		xfrm_policy_kill(ret);
  	return ret;
  }
  EXPORT_SYMBOL(xfrm_policy_byid);
  
  #ifdef CONFIG_SECURITY_NETWORK_XFRM
  static inline int
  xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
  {
  	struct xfrm_policy *pol;
  	int err = 0;
  
  	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
  		if (pol->walk.dead ||
  		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
  		    pol->type != type)
  			continue;
  
  		err = security_xfrm_policy_delete(pol->security);
  		if (err) {
  			xfrm_audit_policy_delete(pol, 0, task_valid);
  			return err;
  		}
  	}
  	return err;
  }
  #else
  static inline int
  xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
  {
  	return 0;
  }
  #endif
  
  int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
  {
  	int dir, err = 0, cnt = 0;
  	struct xfrm_policy *pol;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  
  	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
  	if (err)
  		goto out;
  
  again:
  	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
  		dir = xfrm_policy_id2dir(pol->index);
  		if (pol->walk.dead ||
  		    dir >= XFRM_POLICY_MAX ||
  		    pol->type != type)
  			continue;
  
  		__xfrm_policy_unlink(pol, dir);
  		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  		cnt++;
  		xfrm_audit_policy_delete(pol, 1, task_valid);
  		xfrm_policy_kill(pol);
  		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  		goto again;
  	}
  	if (cnt)
  		__xfrm_policy_inexact_flush(net);
  	else
  		err = -ESRCH;
  out:
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  	return err;
  }
  EXPORT_SYMBOL(xfrm_policy_flush);
  
  int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
  		     int (*func)(struct xfrm_policy *, int, int, void*),
  		     void *data)
  {
  	struct xfrm_policy *pol;
  	struct xfrm_policy_walk_entry *x;
  	int error = 0;
  
  	if (walk->type >= XFRM_POLICY_TYPE_MAX &&
  	    walk->type != XFRM_POLICY_TYPE_ANY)
  		return -EINVAL;
  
  	if (list_empty(&walk->walk.all) && walk->seq != 0)
  		return 0;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	if (list_empty(&walk->walk.all))
  		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
  	else
  		x = list_first_entry(&walk->walk.all,
  				     struct xfrm_policy_walk_entry, all);
  
  	list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
  		if (x->dead)
  			continue;
  		pol = container_of(x, struct xfrm_policy, walk);
  		if (walk->type != XFRM_POLICY_TYPE_ANY &&
  		    walk->type != pol->type)
  			continue;
  		error = func(pol, xfrm_policy_id2dir(pol->index),
  			     walk->seq, data);
  		if (error) {
  			list_move_tail(&walk->walk.all, &x->all);
  			goto out;
  		}
  		walk->seq++;
  	}
  	if (walk->seq == 0) {
  		error = -ENOENT;
  		goto out;
  	}
  	list_del_init(&walk->walk.all);
  out:
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  	return error;
  }
  EXPORT_SYMBOL(xfrm_policy_walk);
  
  void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
  {
  	INIT_LIST_HEAD(&walk->walk.all);
  	walk->walk.dead = 1;
  	walk->type = type;
  	walk->seq = 0;
  }
  EXPORT_SYMBOL(xfrm_policy_walk_init);
  
  void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
  {
  	if (list_empty(&walk->walk.all))
  		return;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
  	list_del(&walk->walk.all);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  }
  EXPORT_SYMBOL(xfrm_policy_walk_done);
  
  /*
   * Find policy to apply to this flow.
   *
   * Returns 0 if policy found, else an -errno.
   */
  static int xfrm_policy_match(const struct xfrm_policy *pol,
  			     const struct flowi *fl,
  			     u8 type, u16 family, int dir, u32 if_id)
  {
  	const struct xfrm_selector *sel = &pol->selector;
  	int ret = -ESRCH;
  	bool match;
  
  	if (pol->family != family ||
  	    pol->if_id != if_id ||
  	    (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
  	    pol->type != type)
  		return ret;
  
  	match = xfrm_selector_match(sel, fl, family);
  	if (match)
  		ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
  						  dir);
  	return ret;
  }
  
  static struct xfrm_pol_inexact_node *
  xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
  				seqcount_spinlock_t *count,
  				const xfrm_address_t *addr, u16 family)
  {
  	const struct rb_node *parent;
  	int seq;
  
  again:
  	seq = read_seqcount_begin(count);
  
  	parent = rcu_dereference_raw(r->rb_node);
  	while (parent) {
  		struct xfrm_pol_inexact_node *node;
  		int delta;
  
  		node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
  
  		delta = xfrm_policy_addr_delta(addr, &node->addr,
  					       node->prefixlen, family);
  		if (delta < 0) {
  			parent = rcu_dereference_raw(parent->rb_left);
  			continue;
  		} else if (delta > 0) {
  			parent = rcu_dereference_raw(parent->rb_right);
  			continue;
  		}
  
  		return node;
  	}
  
  	if (read_seqcount_retry(count, seq))
  		goto again;
  
  	return NULL;
  }
  
  static bool
  xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
  				    struct xfrm_pol_inexact_bin *b,
  				    const xfrm_address_t *saddr,
  				    const xfrm_address_t *daddr)
  {
  	struct xfrm_pol_inexact_node *n;
  	u16 family;
  
  	if (!b)
  		return false;
  
  	family = b->k.family;
  	memset(cand, 0, sizeof(*cand));
  	cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
  
  	n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
  					    family);
  	if (n) {
  		cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
  		n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
  						    family);
  		if (n)
  			cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
  	}
  
  	n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
  					    family);
  	if (n)
  		cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
  
  	return true;
  }
  
  static struct xfrm_pol_inexact_bin *
  xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
  			       u8 dir, u32 if_id)
  {
  	struct xfrm_pol_inexact_key k = {
  		.family = family,
  		.type = type,
  		.dir = dir,
  		.if_id = if_id,
  	};
  
  	write_pnet(&k.net, net);
  
  	return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
  				 xfrm_pol_inexact_params);
  }
  
  static struct xfrm_pol_inexact_bin *
  xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
  			   u8 dir, u32 if_id)
  {
  	struct xfrm_pol_inexact_bin *bin;
  
  	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
  
  	rcu_read_lock();
  	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
  	rcu_read_unlock();
  
  	return bin;
  }
  
  static struct xfrm_policy *
  __xfrm_policy_eval_candidates(struct hlist_head *chain,
  			      struct xfrm_policy *prefer,
  			      const struct flowi *fl,
  			      u8 type, u16 family, int dir, u32 if_id)
  {
  	u32 priority = prefer ? prefer->priority : ~0u;
  	struct xfrm_policy *pol;
  
  	if (!chain)
  		return NULL;
  
  	hlist_for_each_entry_rcu(pol, chain, bydst) {
  		int err;
  
  		if (pol->priority > priority)
  			break;
  
  		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
  		if (err) {
  			if (err != -ESRCH)
  				return ERR_PTR(err);
  
  			continue;
  		}
  
  		if (prefer) {
  			/* matches.  Is it older than *prefer? */
  			if (pol->priority == priority &&
  			    prefer->pos < pol->pos)
  				return prefer;
  		}
  
  		return pol;
  	}
  
  	return NULL;
  }
  
  static struct xfrm_policy *
  xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
  			    struct xfrm_policy *prefer,
  			    const struct flowi *fl,
  			    u8 type, u16 family, int dir, u32 if_id)
  {
  	struct xfrm_policy *tmp;
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
  		tmp = __xfrm_policy_eval_candidates(cand->res[i],
  						    prefer,
  						    fl, type, family, dir,
  						    if_id);
  		if (!tmp)
  			continue;
  
  		if (IS_ERR(tmp))
  			return tmp;
  		prefer = tmp;
  	}
  
  	return prefer;
  }
  
  static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
  						     const struct flowi *fl,
  						     u16 family, u8 dir,
  						     u32 if_id)
  {
  	struct xfrm_pol_inexact_candidates cand;
  	const xfrm_address_t *daddr, *saddr;
  	struct xfrm_pol_inexact_bin *bin;
  	struct xfrm_policy *pol, *ret;
  	struct hlist_head *chain;
  	unsigned int sequence;
  	int err;
  
  	daddr = xfrm_flowi_daddr(fl, family);
  	saddr = xfrm_flowi_saddr(fl, family);
  	if (unlikely(!daddr || !saddr))
  		return NULL;
  
  	rcu_read_lock();
   retry:
  	do {
  		sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
  		chain = policy_hash_direct(net, daddr, saddr, family, dir);
  	} while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
  
  	ret = NULL;
  	hlist_for_each_entry_rcu(pol, chain, bydst) {
  		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
  		if (err) {
  			if (err == -ESRCH)
  				continue;
  			else {
  				ret = ERR_PTR(err);
  				goto fail;
  			}
  		} else {
  			ret = pol;
  			break;
  		}
  	}
  	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
  	if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
  							 daddr))
  		goto skip_inexact;
  
  	pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
  					  family, dir, if_id);
  	if (pol) {
  		ret = pol;
  		if (IS_ERR(pol))
  			goto fail;
  	}
  
  skip_inexact:
  	if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
  		goto retry;
  
  	if (ret && !xfrm_pol_hold_rcu(ret))
  		goto retry;
  fail:
  	rcu_read_unlock();
  
  	return ret;
  }
  
  static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
  					      const struct flowi *fl,
  					      u16 family, u8 dir, u32 if_id)
  {
  #ifdef CONFIG_XFRM_SUB_POLICY
  	struct xfrm_policy *pol;
  
  	pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
  					dir, if_id);
  	if (pol != NULL)
  		return pol;
  #endif
  	return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
  					 dir, if_id);
  }
  
  static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
  						 const struct flowi *fl,
  						 u16 family, u32 if_id)
  {
  	struct xfrm_policy *pol;
  
  	rcu_read_lock();
   again:
  	pol = rcu_dereference(sk->sk_policy[dir]);
  	if (pol != NULL) {
  		bool match;
  		int err = 0;
  
  		if (pol->family != family) {
  			pol = NULL;
  			goto out;
  		}
  
  		match = xfrm_selector_match(&pol->selector, fl, family);
  		if (match) {
  			if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
  			    pol->if_id != if_id) {
  				pol = NULL;
  				goto out;
  			}
  			err = security_xfrm_policy_lookup(pol->security,
  						      fl->flowi_secid,
  						      dir);
  			if (!err) {
  				if (!xfrm_pol_hold_rcu(pol))
  					goto again;
  			} else if (err == -ESRCH) {
  				pol = NULL;
  			} else {
  				pol = ERR_PTR(err);
  			}
  		} else
  			pol = NULL;
  	}
  out:
  	rcu_read_unlock();
  	return pol;
  }
  
  static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
  {
  	struct net *net = xp_net(pol);
  
  	list_add(&pol->walk.all, &net->xfrm.policy_all);
  	net->xfrm.policy_count[dir]++;
  	xfrm_pol_hold(pol);
  }
  
  static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  						int dir)
  {
  	struct net *net = xp_net(pol);
  
  	if (list_empty(&pol->walk.all))
  		return NULL;
  
  	/* Socket policies are not hashed. */
  	if (!hlist_unhashed(&pol->bydst)) {
  		hlist_del_rcu(&pol->bydst);
  		hlist_del_init(&pol->bydst_inexact_list);
  		hlist_del(&pol->byidx);
  	}
  
  	list_del_init(&pol->walk.all);
  	net->xfrm.policy_count[dir]--;
  
  	return pol;
  }
  
  static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
  {
  	__xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
  }
  
  static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
  {
  	__xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
  }
  
  int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
  {
  	struct net *net = xp_net(pol);
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	pol = __xfrm_policy_unlink(pol, dir);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  	if (pol) {
  		xfrm_policy_kill(pol);
  		return 0;
  	}
  	return -ENOENT;
  }
  EXPORT_SYMBOL(xfrm_policy_delete);
  
  int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
  {
  	struct net *net = sock_net(sk);
  	struct xfrm_policy *old_pol;
  
  #ifdef CONFIG_XFRM_SUB_POLICY
  	if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
  		return -EINVAL;
  #endif
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
  				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
  	if (pol) {
  		pol->curlft.add_time = ktime_get_real_seconds();
  		pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
  		xfrm_sk_policy_link(pol, dir);
  	}
  	rcu_assign_pointer(sk->sk_policy[dir], pol);
  	if (old_pol) {
  		if (pol)
  			xfrm_policy_requeue(old_pol, pol);
  
  		/* Unlinking succeeds always. This is the only function
  		 * allowed to delete or replace socket policy.
  		 */
  		xfrm_sk_policy_unlink(old_pol, dir);
  	}
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	if (old_pol) {
  		xfrm_policy_kill(old_pol);
  	}
  	return 0;
  }
  
  static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
  {
  	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
  	struct net *net = xp_net(old);
  
  	if (newp) {
  		newp->selector = old->selector;
  		if (security_xfrm_policy_clone(old->security,
  					       &newp->security)) {
  			kfree(newp);
  			return NULL;  /* ENOMEM */
  		}
  		newp->lft = old->lft;
  		newp->curlft = old->curlft;
  		newp->mark = old->mark;
  		newp->if_id = old->if_id;
  		newp->action = old->action;
  		newp->flags = old->flags;
  		newp->xfrm_nr = old->xfrm_nr;
  		newp->index = old->index;
  		newp->type = old->type;
  		newp->family = old->family;
  		memcpy(newp->xfrm_vec, old->xfrm_vec,
  		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
  		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  		xfrm_sk_policy_link(newp, dir);
  		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  		xfrm_pol_put(newp);
  	}
  	return newp;
  }
  
  int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
  {
  	const struct xfrm_policy *p;
  	struct xfrm_policy *np;
  	int i, ret = 0;
  
  	rcu_read_lock();
  	for (i = 0; i < 2; i++) {
  		p = rcu_dereference(osk->sk_policy[i]);
  		if (p) {
  			np = clone_policy(p, i);
  			if (unlikely(!np)) {
  				ret = -ENOMEM;
  				break;
  			}
  			rcu_assign_pointer(sk->sk_policy[i], np);
  		}
  	}
  	rcu_read_unlock();
  	return ret;
  }
  
  static int
  xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
  	       xfrm_address_t *remote, unsigned short family, u32 mark)
  {
  	int err;
  	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
  
  	if (unlikely(afinfo == NULL))
  		return -EINVAL;
  	err = afinfo->get_saddr(net, oif, local, remote, mark);
  	rcu_read_unlock();
  	return err;
  }
  
  /* Resolve list of templates for the flow, given policy. */
  
  static int
  xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
  		      struct xfrm_state **xfrm, unsigned short family)
  {
  	struct net *net = xp_net(policy);
  	int nx;
  	int i, error;
  	xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
  	xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
  	xfrm_address_t tmp;
  
  	for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
  		struct xfrm_state *x;
  		xfrm_address_t *remote = daddr;
  		xfrm_address_t *local  = saddr;
  		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
  
  		if (tmpl->mode == XFRM_MODE_TUNNEL ||
  		    tmpl->mode == XFRM_MODE_BEET) {
  			remote = &tmpl->id.daddr;
  			local = &tmpl->saddr;
  			if (xfrm_addr_any(local, tmpl->encap_family)) {
  				error = xfrm_get_saddr(net, fl->flowi_oif,
  						       &tmp, remote,
  						       tmpl->encap_family, 0);
  				if (error)
  					goto fail;
  				local = &tmp;
  			}
  		}
  
  		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
  				    family, policy->if_id);
  
  		if (x && x->km.state == XFRM_STATE_VALID) {
  			xfrm[nx++] = x;
  			daddr = remote;
  			saddr = local;
  			continue;
  		}
  		if (x) {
  			error = (x->km.state == XFRM_STATE_ERROR ?
  				 -EINVAL : -EAGAIN);
  			xfrm_state_put(x);
  		} else if (error == -ESRCH) {
  			error = -EAGAIN;
  		}
  
  		if (!tmpl->optional)
  			goto fail;
  	}
  	return nx;
  
  fail:
  	for (nx--; nx >= 0; nx--)
  		xfrm_state_put(xfrm[nx]);
  	return error;
  }
  
  static int
  xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
  		  struct xfrm_state **xfrm, unsigned short family)
  {
  	struct xfrm_state *tp[XFRM_MAX_DEPTH];
  	struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
  	int cnx = 0;
  	int error;
  	int ret;
  	int i;
  
  	for (i = 0; i < npols; i++) {
  		if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
  			error = -ENOBUFS;
  			goto fail;
  		}
  
  		ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
  		if (ret < 0) {
  			error = ret;
  			goto fail;
  		} else
  			cnx += ret;
  	}
  
  	/* found states are sorted for outbound processing */
  	if (npols > 1)
  		xfrm_state_sort(xfrm, tpp, cnx, family);
  
  	return cnx;
  
   fail:
  	for (cnx--; cnx >= 0; cnx--)
  		xfrm_state_put(tpp[cnx]);
  	return error;
  
  }
  
  static int xfrm_get_tos(const struct flowi *fl, int family)
  {
  	if (family == AF_INET)
  		return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos;
  
  	return 0;
  }
  
  static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
  {
  	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
  	struct dst_ops *dst_ops;
  	struct xfrm_dst *xdst;
  
  	if (!afinfo)
  		return ERR_PTR(-EINVAL);
  
  	switch (family) {
  	case AF_INET:
  		dst_ops = &net->xfrm.xfrm4_dst_ops;
  		break;
  #if IS_ENABLED(CONFIG_IPV6)
  	case AF_INET6:
  		dst_ops = &net->xfrm.xfrm6_dst_ops;
  		break;
  #endif
  	default:
  		BUG();
  	}
  	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
  
  	if (likely(xdst)) {
  		struct dst_entry *dst = &xdst->u.dst;
  
  		memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
  	} else
  		xdst = ERR_PTR(-ENOBUFS);
  
  	rcu_read_unlock();
  
  	return xdst;
  }
  
  static void xfrm_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;
  	}
  }
  
  static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
  				const struct flowi *fl)
  {
  	const struct xfrm_policy_afinfo *afinfo =
  		xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
  	int err;
  
  	if (!afinfo)
  		return -EINVAL;
  
  	err = afinfo->fill_dst(xdst, dev, fl);
  
  	rcu_read_unlock();
  
  	return err;
  }
  
  
  /* Allocate chain of dst_entry's, attach known xfrm's, calculate
   * all the metrics... Shortly, bundle a bundle.
   */
  
  static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
  					    struct xfrm_state **xfrm,
  					    struct xfrm_dst **bundle,
  					    int nx,
  					    const struct flowi *fl,
  					    struct dst_entry *dst)
  {
  	const struct xfrm_state_afinfo *afinfo;
  	const struct xfrm_mode *inner_mode;
  	struct net *net = xp_net(policy);
  	unsigned long now = jiffies;
  	struct net_device *dev;
  	struct xfrm_dst *xdst_prev = NULL;
  	struct xfrm_dst *xdst0 = NULL;
  	int i = 0;
  	int err;
  	int header_len = 0;
  	int nfheader_len = 0;
  	int trailer_len = 0;
  	int tos;
  	int family = policy->selector.family;
  	xfrm_address_t saddr, daddr;
  
  	xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
  
  	tos = xfrm_get_tos(fl, family);
  
  	dst_hold(dst);
  
  	for (; i < nx; i++) {
  		struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
  		struct dst_entry *dst1 = &xdst->u.dst;
  
  		err = PTR_ERR(xdst);
  		if (IS_ERR(xdst)) {
  			dst_release(dst);
  			goto put_states;
  		}
  
  		bundle[i] = xdst;
  		if (!xdst_prev)
  			xdst0 = xdst;
  		else
  			/* Ref count is taken during xfrm_alloc_dst()
  			 * No need to do dst_clone() on dst1
  			 */
  			xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
  
  		if (xfrm[i]->sel.family == AF_UNSPEC) {
  			inner_mode = xfrm_ip2inner_mode(xfrm[i],
  							xfrm_af2proto(family));
  			if (!inner_mode) {
  				err = -EAFNOSUPPORT;
  				dst_release(dst);
  				goto put_states;
  			}
  		} else
  			inner_mode = &xfrm[i]->inner_mode;
  
  		xdst->route = dst;
  		dst_copy_metrics(dst1, dst);
  
  		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
  			__u32 mark = 0;
  
  			if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
  				mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
  
  			family = xfrm[i]->props.family;
  			dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
  					      &saddr, &daddr, family, mark);
  			err = PTR_ERR(dst);
  			if (IS_ERR(dst))
  				goto put_states;
  		} else
  			dst_hold(dst);
  
  		dst1->xfrm = xfrm[i];
  		xdst->xfrm_genid = xfrm[i]->genid;
  
  		dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
  		dst1->lastuse = now;
  
  		dst1->input = dst_discard;
  
  		rcu_read_lock();
  		afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
  		if (likely(afinfo))
  			dst1->output = afinfo->output;
  		else
  			dst1->output = dst_discard_out;
  		rcu_read_unlock();
  
  		xdst_prev = xdst;
  
  		header_len += xfrm[i]->props.header_len;
  		if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
  			nfheader_len += xfrm[i]->props.header_len;
  		trailer_len += xfrm[i]->props.trailer_len;
  	}
  
  	xfrm_dst_set_child(xdst_prev, dst);
  	xdst0->path = dst;
  
  	err = -ENODEV;
  	dev = dst->dev;
  	if (!dev)
  		goto free_dst;
  
  	xfrm_init_path(xdst0, dst, nfheader_len);
  	xfrm_init_pmtu(bundle, nx);
  
  	for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
  	     xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
  		err = xfrm_fill_dst(xdst_prev, dev, fl);
  		if (err)
  			goto free_dst;
  
  		xdst_prev->u.dst.header_len = header_len;
  		xdst_prev->u.dst.trailer_len = trailer_len;
  		header_len -= xdst_prev->u.dst.xfrm->props.header_len;
  		trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
  	}
  
  	return &xdst0->u.dst;
  
  put_states:
  	for (; i < nx; i++)
  		xfrm_state_put(xfrm[i]);
  free_dst:
  	if (xdst0)
  		dst_release_immediate(&xdst0->u.dst);
  
  	return ERR_PTR(err);
  }
  
  static int xfrm_expand_policies(const struct flowi *fl, u16 family,
  				struct xfrm_policy **pols,
  				int *num_pols, int *num_xfrms)
  {
  	int i;
  
  	if (*num_pols == 0 || !pols[0]) {
  		*num_pols = 0;
  		*num_xfrms = 0;
  		return 0;
  	}
  	if (IS_ERR(pols[0]))
  		return PTR_ERR(pols[0]);
  
  	*num_xfrms = pols[0]->xfrm_nr;
  
  #ifdef CONFIG_XFRM_SUB_POLICY
  	if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
  	    pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
  		pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
  						    XFRM_POLICY_TYPE_MAIN,
  						    fl, family,
  						    XFRM_POLICY_OUT,
  						    pols[0]->if_id);
  		if (pols[1]) {
  			if (IS_ERR(pols[1])) {
  				xfrm_pols_put(pols, *num_pols);
  				return PTR_ERR(pols[1]);
  			}
  			(*num_pols)++;
  			(*num_xfrms) += pols[1]->xfrm_nr;
  		}
  	}
  #endif
  	for (i = 0; i < *num_pols; i++) {
  		if (pols[i]->action != XFRM_POLICY_ALLOW) {
  			*num_xfrms = -1;
  			break;
  		}
  	}
  
  	return 0;
  
  }
  
  static struct xfrm_dst *
  xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
  			       const struct flowi *fl, u16 family,
  			       struct dst_entry *dst_orig)
  {
  	struct net *net = xp_net(pols[0]);
  	struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
  	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
  	struct xfrm_dst *xdst;
  	struct dst_entry *dst;
  	int err;
  
  	/* Try to instantiate a bundle */
  	err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
  	if (err <= 0) {
  		if (err == 0)
  			return NULL;
  
  		if (err != -EAGAIN)
  			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
  		return ERR_PTR(err);
  	}
  
  	dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
  	if (IS_ERR(dst)) {
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
  		return ERR_CAST(dst);
  	}
  
  	xdst = (struct xfrm_dst *)dst;
  	xdst->num_xfrms = err;
  	xdst->num_pols = num_pols;
  	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
  	xdst->policy_genid = atomic_read(&pols[0]->genid);
  
  	return xdst;
  }
  
  static void xfrm_policy_queue_process(struct timer_list *t)
  {
  	struct sk_buff *skb;
  	struct sock *sk;
  	struct dst_entry *dst;
  	struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
  	struct net *net = xp_net(pol);
  	struct xfrm_policy_queue *pq = &pol->polq;
  	struct flowi fl;
  	struct sk_buff_head list;
  	__u32 skb_mark;
  
  	spin_lock(&pq->hold_queue.lock);
  	skb = skb_peek(&pq->hold_queue);
  	if (!skb) {
  		spin_unlock(&pq->hold_queue.lock);
  		goto out;
  	}
  	dst = skb_dst(skb);
  	sk = skb->sk;
  
  	/* Fixup the mark to support VTI. */
  	skb_mark = skb->mark;
  	skb->mark = pol->mark.v;
  	xfrm_decode_session(skb, &fl, dst->ops->family);
  	skb->mark = skb_mark;
  	spin_unlock(&pq->hold_queue.lock);
  
  	dst_hold(xfrm_dst_path(dst));
  	dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
  	if (IS_ERR(dst))
  		goto purge_queue;
  
  	if (dst->flags & DST_XFRM_QUEUE) {
  		dst_release(dst);
  
  		if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
  			goto purge_queue;
  
  		pq->timeout = pq->timeout << 1;
  		if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
  			xfrm_pol_hold(pol);
  		goto out;
  	}
  
  	dst_release(dst);
  
  	__skb_queue_head_init(&list);
  
  	spin_lock(&pq->hold_queue.lock);
  	pq->timeout = 0;
  	skb_queue_splice_init(&pq->hold_queue, &list);
  	spin_unlock(&pq->hold_queue.lock);
  
  	while (!skb_queue_empty(&list)) {
  		skb = __skb_dequeue(&list);
  
  		/* Fixup the mark to support VTI. */
  		skb_mark = skb->mark;
  		skb->mark = pol->mark.v;
  		xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
  		skb->mark = skb_mark;
  
  		dst_hold(xfrm_dst_path(skb_dst(skb)));
  		dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
  		if (IS_ERR(dst)) {
  			kfree_skb(skb);
  			continue;
  		}
  
  		nf_reset_ct(skb);
  		skb_dst_drop(skb);
  		skb_dst_set(skb, dst);
  
  		dst_output(net, skb->sk, skb);
  	}
  
  out:
  	xfrm_pol_put(pol);
  	return;
  
  purge_queue:
  	pq->timeout = 0;
  	skb_queue_purge(&pq->hold_queue);
  	xfrm_pol_put(pol);
  }
  
  static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
  {
  	unsigned long sched_next;
  	struct dst_entry *dst = skb_dst(skb);
  	struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
  	struct xfrm_policy *pol = xdst->pols[0];
  	struct xfrm_policy_queue *pq = &pol->polq;
  
  	if (unlikely(skb_fclone_busy(sk, skb))) {
  		kfree_skb(skb);
  		return 0;
  	}
  
  	if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
  		kfree_skb(skb);
  		return -EAGAIN;
  	}
  
  	skb_dst_force(skb);
  
  	spin_lock_bh(&pq->hold_queue.lock);
  
  	if (!pq->timeout)
  		pq->timeout = XFRM_QUEUE_TMO_MIN;
  
  	sched_next = jiffies + pq->timeout;
  
  	if (del_timer(&pq->hold_timer)) {
  		if (time_before(pq->hold_timer.expires, sched_next))
  			sched_next = pq->hold_timer.expires;
  		xfrm_pol_put(pol);
  	}
  
  	__skb_queue_tail(&pq->hold_queue, skb);
  	if (!mod_timer(&pq->hold_timer, sched_next))
  		xfrm_pol_hold(pol);
  
  	spin_unlock_bh(&pq->hold_queue.lock);
  
  	return 0;
  }
  
  static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
  						 struct xfrm_flo *xflo,
  						 const struct flowi *fl,
  						 int num_xfrms,
  						 u16 family)
  {
  	int err;
  	struct net_device *dev;
  	struct dst_entry *dst;
  	struct dst_entry *dst1;
  	struct xfrm_dst *xdst;
  
  	xdst = xfrm_alloc_dst(net, family);
  	if (IS_ERR(xdst))
  		return xdst;
  
  	if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
  	    net->xfrm.sysctl_larval_drop ||
  	    num_xfrms <= 0)
  		return xdst;
  
  	dst = xflo->dst_orig;
  	dst1 = &xdst->u.dst;
  	dst_hold(dst);
  	xdst->route = dst;
  
  	dst_copy_metrics(dst1, dst);
  
  	dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
  	dst1->flags |= DST_XFRM_QUEUE;
  	dst1->lastuse = jiffies;
  
  	dst1->input = dst_discard;
  	dst1->output = xdst_queue_output;
  
  	dst_hold(dst);
  	xfrm_dst_set_child(xdst, dst);
  	xdst->path = dst;
  
  	xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
  
  	err = -ENODEV;
  	dev = dst->dev;
  	if (!dev)
  		goto free_dst;
  
  	err = xfrm_fill_dst(xdst, dev, fl);
  	if (err)
  		goto free_dst;
  
  out:
  	return xdst;
  
  free_dst:
  	dst_release(dst1);
  	xdst = ERR_PTR(err);
  	goto out;
  }
  
  static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
  					   const struct flowi *fl,
  					   u16 family, u8 dir,
  					   struct xfrm_flo *xflo, u32 if_id)
  {
  	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
  	int num_pols = 0, num_xfrms = 0, err;
  	struct xfrm_dst *xdst;
  
  	/* Resolve policies to use if we couldn't get them from
  	 * previous cache entry */
  	num_pols = 1;
  	pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
  	err = xfrm_expand_policies(fl, family, pols,
  					   &num_pols, &num_xfrms);
  	if (err < 0)
  		goto inc_error;
  	if (num_pols == 0)
  		return NULL;
  	if (num_xfrms <= 0)
  		goto make_dummy_bundle;
  
  	xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
  					      xflo->dst_orig);
  	if (IS_ERR(xdst)) {
  		err = PTR_ERR(xdst);
  		if (err == -EREMOTE) {
  			xfrm_pols_put(pols, num_pols);
  			return NULL;
  		}
  
  		if (err != -EAGAIN)
  			goto error;
  		goto make_dummy_bundle;
  	} else if (xdst == NULL) {
  		num_xfrms = 0;
  		goto make_dummy_bundle;
  	}
  
  	return xdst;
  
  make_dummy_bundle:
  	/* We found policies, but there's no bundles to instantiate:
  	 * either because the policy blocks, has no transformations or
  	 * we could not build template (no xfrm_states).*/
  	xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
  	if (IS_ERR(xdst)) {
  		xfrm_pols_put(pols, num_pols);
  		return ERR_CAST(xdst);
  	}
  	xdst->num_pols = num_pols;
  	xdst->num_xfrms = num_xfrms;
  	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
  
  	return xdst;
  
  inc_error:
  	XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
  error:
  	xfrm_pols_put(pols, num_pols);
  	return ERR_PTR(err);
  }
  
  static struct dst_entry *make_blackhole(struct net *net, u16 family,
  					struct dst_entry *dst_orig)
  {
  	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
  	struct dst_entry *ret;
  
  	if (!afinfo) {
  		dst_release(dst_orig);
  		return ERR_PTR(-EINVAL);
  	} else {
  		ret = afinfo->blackhole_route(net, dst_orig);
  	}
  	rcu_read_unlock();
  
  	return ret;
  }
  
  /* Finds/creates a bundle for given flow and if_id
   *
   * At the moment we eat a raw IP route. Mostly to speed up lookups
   * on interfaces with disabled IPsec.
   *
   * xfrm_lookup uses an if_id of 0 by default, and is provided for
   * compatibility
   */
  struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
  					struct dst_entry *dst_orig,
  					const struct flowi *fl,
  					const struct sock *sk,
  					int flags, u32 if_id)
  {
  	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
  	struct xfrm_dst *xdst;
  	struct dst_entry *dst, *route;
  	u16 family = dst_orig->ops->family;
  	u8 dir = XFRM_POLICY_OUT;
  	int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
  
  	dst = NULL;
  	xdst = NULL;
  	route = NULL;
  
  	sk = sk_const_to_full_sk(sk);
  	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
  		num_pols = 1;
  		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
  						if_id);
  		err = xfrm_expand_policies(fl, family, pols,
  					   &num_pols, &num_xfrms);
  		if (err < 0)
  			goto dropdst;
  
  		if (num_pols) {
  			if (num_xfrms <= 0) {
  				drop_pols = num_pols;
  				goto no_transform;
  			}
  
  			xdst = xfrm_resolve_and_create_bundle(
  					pols, num_pols, fl,
  					family, dst_orig);
  
  			if (IS_ERR(xdst)) {
  				xfrm_pols_put(pols, num_pols);
  				err = PTR_ERR(xdst);
  				if (err == -EREMOTE)
  					goto nopol;
  
  				goto dropdst;
  			} else if (xdst == NULL) {
  				num_xfrms = 0;
  				drop_pols = num_pols;
  				goto no_transform;
  			}
  
  			route = xdst->route;
  		}
  	}
  
  	if (xdst == NULL) {
  		struct xfrm_flo xflo;
  
  		xflo.dst_orig = dst_orig;
  		xflo.flags = flags;
  
  		/* To accelerate a bit...  */
  		if (!if_id && ((dst_orig->flags & DST_NOXFRM) ||
  			       !net->xfrm.policy_count[XFRM_POLICY_OUT]))
  			goto nopol;
  
  		xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
  		if (xdst == NULL)
  			goto nopol;
  		if (IS_ERR(xdst)) {
  			err = PTR_ERR(xdst);
  			goto dropdst;
  		}
  
  		num_pols = xdst->num_pols;
  		num_xfrms = xdst->num_xfrms;
  		memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
  		route = xdst->route;
  	}
  
  	dst = &xdst->u.dst;
  	if (route == NULL && num_xfrms > 0) {
  		/* The only case when xfrm_bundle_lookup() returns a
  		 * bundle with null route, is when the template could
  		 * not be resolved. It means policies are there, but
  		 * bundle could not be created, since we don't yet
  		 * have the xfrm_state's. We need to wait for KM to
  		 * negotiate new SA's or bail out with error.*/
  		if (net->xfrm.sysctl_larval_drop) {
  			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
  			err = -EREMOTE;
  			goto error;
  		}
  
  		err = -EAGAIN;
  
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
  		goto error;
  	}
  
  no_transform:
  	if (num_pols == 0)
  		goto nopol;
  
  	if ((flags & XFRM_LOOKUP_ICMP) &&
  	    !(pols[0]->flags & XFRM_POLICY_ICMP)) {
  		err = -ENOENT;
  		goto error;
  	}
  
  	for (i = 0; i < num_pols; i++)
  		pols[i]->curlft.use_time = ktime_get_real_seconds();
  
  	if (num_xfrms < 0) {
  		/* Prohibit the flow */
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
  		err = -EPERM;
  		goto error;
  	} else if (num_xfrms > 0) {
  		/* Flow transformed */
  		dst_release(dst_orig);
  	} else {
  		/* Flow passes untransformed */
  		dst_release(dst);
  		dst = dst_orig;
  	}
  ok:
  	xfrm_pols_put(pols, drop_pols);
  	if (dst && dst->xfrm &&
  	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
  		dst->flags |= DST_XFRM_TUNNEL;
  	return dst;
  
  nopol:
  	if (!(flags & XFRM_LOOKUP_ICMP)) {
  		dst = dst_orig;
  		goto ok;
  	}
  	err = -ENOENT;
  error:
  	dst_release(dst);
  dropdst:
  	if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
  		dst_release(dst_orig);
  	xfrm_pols_put(pols, drop_pols);
  	return ERR_PTR(err);
  }
  EXPORT_SYMBOL(xfrm_lookup_with_ifid);
  
  /* Main function: finds/creates a bundle for given flow.
   *
   * At the moment we eat a raw IP route. Mostly to speed up lookups
   * on interfaces with disabled IPsec.
   */
  struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
  			      const struct flowi *fl, const struct sock *sk,
  			      int flags)
  {
  	return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
  }
  EXPORT_SYMBOL(xfrm_lookup);
  
  /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
   * Otherwise we may send out blackholed packets.
   */
  struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
  				    const struct flowi *fl,
  				    const struct sock *sk, int flags)
  {
  	struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
  					    flags | XFRM_LOOKUP_QUEUE |
  					    XFRM_LOOKUP_KEEP_DST_REF);
  
  	if (PTR_ERR(dst) == -EREMOTE)
  		return make_blackhole(net, dst_orig->ops->family, dst_orig);
  
  	if (IS_ERR(dst))
  		dst_release(dst_orig);
  
  	return dst;
  }
  EXPORT_SYMBOL(xfrm_lookup_route);
  
  static inline int
  xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
  {
  	struct sec_path *sp = skb_sec_path(skb);
  	struct xfrm_state *x;
  
  	if (!sp || idx < 0 || idx >= sp->len)
  		return 0;
  	x = sp->xvec[idx];
  	if (!x->type->reject)
  		return 0;
  	return x->type->reject(x, skb, fl);
  }
  
  /* When skb is transformed back to its "native" form, we have to
   * check policy restrictions. At the moment we make this in maximally
   * stupid way. Shame on me. :-) Of course, connected sockets must
   * have policy cached at them.
   */
  
  static inline int
  xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
  	      unsigned short family)
  {
  	if (xfrm_state_kern(x))
  		return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
  	return	x->id.proto == tmpl->id.proto &&
  		(x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
  		(x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
  		x->props.mode == tmpl->mode &&
  		(tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
  		 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
  		!(x->props.mode != XFRM_MODE_TRANSPORT &&
  		  xfrm_state_addr_cmp(tmpl, x, family));
  }
  
  /*
   * 0 or more than 0 is returned when validation is succeeded (either bypass
   * because of optional transport mode, or next index of the mathced secpath
   * state with the template.
   * -1 is returned when no matching template is found.
   * Otherwise "-2 - errored_index" is returned.
   */
  static inline int
  xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
  	       unsigned short family)
  {
  	int idx = start;
  
  	if (tmpl->optional) {
  		if (tmpl->mode == XFRM_MODE_TRANSPORT)
  			return start;
  	} else
  		start = -1;
  	for (; idx < sp->len; idx++) {
  		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
  			return ++idx;
  		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
  			if (start == -1)
  				start = -2-idx;
  			break;
  		}
  	}
  	return start;
  }
  
  static void
  decode_session4(struct sk_buff *skb, struct flowi *fl, bool reverse)
  {
  	const struct iphdr *iph = ip_hdr(skb);
  	int ihl = iph->ihl;
  	u8 *xprth = skb_network_header(skb) + ihl * 4;
  	struct flowi4 *fl4 = &fl->u.ip4;
  	int oif = 0;
  
  	if (skb_dst(skb) && skb_dst(skb)->dev)
  		oif = skb_dst(skb)->dev->ifindex;
  
  	memset(fl4, 0, sizeof(struct flowi4));
  	fl4->flowi4_mark = skb->mark;
  	fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
  
  	fl4->flowi4_proto = iph->protocol;
  	fl4->daddr = reverse ? iph->saddr : iph->daddr;
  	fl4->saddr = reverse ? iph->daddr : iph->saddr;
  	fl4->flowi4_tos = iph->tos;
  
  	if (!ip_is_fragment(iph)) {
  		switch (iph->protocol) {
  		case IPPROTO_UDP:
  		case IPPROTO_UDPLITE:
  		case IPPROTO_TCP:
  		case IPPROTO_SCTP:
  		case IPPROTO_DCCP:
  			if (xprth + 4 < skb->data ||
  			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
  				__be16 *ports;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				ports = (__be16 *)xprth;
  
  				fl4->fl4_sport = ports[!!reverse];
  				fl4->fl4_dport = ports[!reverse];
  			}
  			break;
  		case IPPROTO_ICMP:
  			if (xprth + 2 < skb->data ||
  			    pskb_may_pull(skb, xprth + 2 - skb->data)) {
  				u8 *icmp;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				icmp = xprth;
  
  				fl4->fl4_icmp_type = icmp[0];
  				fl4->fl4_icmp_code = icmp[1];
  			}
  			break;
  		case IPPROTO_ESP:
  			if (xprth + 4 < skb->data ||
  			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
  				__be32 *ehdr;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				ehdr = (__be32 *)xprth;
  
  				fl4->fl4_ipsec_spi = ehdr[0];
  			}
  			break;
  		case IPPROTO_AH:
  			if (xprth + 8 < skb->data ||
  			    pskb_may_pull(skb, xprth + 8 - skb->data)) {
  				__be32 *ah_hdr;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				ah_hdr = (__be32 *)xprth;
  
  				fl4->fl4_ipsec_spi = ah_hdr[1];
  			}
  			break;
  		case IPPROTO_COMP:
  			if (xprth + 4 < skb->data ||
  			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
  				__be16 *ipcomp_hdr;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				ipcomp_hdr = (__be16 *)xprth;
  
  				fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
  			}
  			break;
  		case IPPROTO_GRE:
  			if (xprth + 12 < skb->data ||
  			    pskb_may_pull(skb, xprth + 12 - skb->data)) {
  				__be16 *greflags;
  				__be32 *gre_hdr;
  
  				xprth = skb_network_header(skb) + ihl * 4;
  				greflags = (__be16 *)xprth;
  				gre_hdr = (__be32 *)xprth;
  
  				if (greflags[0] & GRE_KEY) {
  					if (greflags[0] & GRE_CSUM)
  						gre_hdr++;
  					fl4->fl4_gre_key = gre_hdr[1];
  				}
  			}
  			break;
  		default:
  			fl4->fl4_ipsec_spi = 0;
  			break;
  		}
  	}
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static void
  decode_session6(struct sk_buff *skb, struct flowi *fl, bool reverse)
  {
  	struct flowi6 *fl6 = &fl->u.ip6;
  	int onlyproto = 0;
  	const struct ipv6hdr *hdr = ipv6_hdr(skb);
  	u32 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) && skb_dst(skb)->dev)
  		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 + sizeof(*exthdr) < skb->data ||
  	       pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
  		nh = skb_network_header(skb);
  		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
  
  		switch (nexthdr) {
  		case NEXTHDR_FRAGMENT:
  			onlyproto = 1;
  			fallthrough;
  		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 && (nh + offset + 2 < skb->data ||
  			    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 && (nh + offset + 3 < skb->data ||
  			    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;
  		}
  	}
  }
  #endif
  
  int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
  			  unsigned int family, int reverse)
  {
  	switch (family) {
  	case AF_INET:
  		decode_session4(skb, fl, reverse);
  		break;
  #if IS_ENABLED(CONFIG_IPV6)
  	case AF_INET6:
  		decode_session6(skb, fl, reverse);
  		break;
  #endif
  	default:
  		return -EAFNOSUPPORT;
  	}
  
  	return security_xfrm_decode_session(skb, &fl->flowi_secid);
  }
  EXPORT_SYMBOL(__xfrm_decode_session);
  
  static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
  {
  	for (; k < sp->len; k++) {
  		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
  			*idxp = k;
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
  			unsigned short family)
  {
  	struct net *net = dev_net(skb->dev);
  	struct xfrm_policy *pol;
  	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
  	int npols = 0;
  	int xfrm_nr;
  	int pi;
  	int reverse;
  	struct flowi fl;
  	int xerr_idx = -1;
  	const struct xfrm_if_cb *ifcb;
  	struct sec_path *sp;
  	struct xfrm_if *xi;
  	u32 if_id = 0;
  
  	rcu_read_lock();
  	ifcb = xfrm_if_get_cb();
  
  	if (ifcb) {
  		xi = ifcb->decode_session(skb, family);
  		if (xi) {
  			if_id = xi->p.if_id;
  			net = xi->net;
  		}
  	}
  	rcu_read_unlock();
  
  	reverse = dir & ~XFRM_POLICY_MASK;
  	dir &= XFRM_POLICY_MASK;
  
  	if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
  		return 0;
  	}
  
  	nf_nat_decode_session(skb, &fl, family);
  
  	/* First, check used SA against their selectors. */
  	sp = skb_sec_path(skb);
  	if (sp) {
  		int i;
  
  		for (i = sp->len - 1; i >= 0; i--) {
  			struct xfrm_state *x = sp->xvec[i];
  			if (!xfrm_selector_match(&x->sel, &fl, family)) {
  				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
  				return 0;
  			}
  		}
  	}
  
  	pol = NULL;
  	sk = sk_to_full_sk(sk);
  	if (sk && sk->sk_policy[dir]) {
  		pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
  		if (IS_ERR(pol)) {
  			XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
  			return 0;
  		}
  	}
  
  	if (!pol)
  		pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
  
  	if (IS_ERR(pol)) {
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
  		return 0;
  	}
  
  	if (!pol) {
  		if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
  			xfrm_secpath_reject(xerr_idx, skb, &fl);
  			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
  			return 0;
  		}
  		return 1;
  	}
  
  	pol->curlft.use_time = ktime_get_real_seconds();
  
  	pols[0] = pol;
  	npols++;
  #ifdef CONFIG_XFRM_SUB_POLICY
  	if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
  		pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
  						    &fl, family,
  						    XFRM_POLICY_IN, if_id);
  		if (pols[1]) {
  			if (IS_ERR(pols[1])) {
  				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
  				return 0;
  			}
  			pols[1]->curlft.use_time = ktime_get_real_seconds();
  			npols++;
  		}
  	}
  #endif
  
  	if (pol->action == XFRM_POLICY_ALLOW) {
  		static struct sec_path dummy;
  		struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
  		struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
  		struct xfrm_tmpl **tpp = tp;
  		int ti = 0;
  		int i, k;
  
  		sp = skb_sec_path(skb);
  		if (!sp)
  			sp = &dummy;
  
  		for (pi = 0; pi < npols; pi++) {
  			if (pols[pi] != pol &&
  			    pols[pi]->action != XFRM_POLICY_ALLOW) {
  				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
  				goto reject;
  			}
  			if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
  				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  				goto reject_error;
  			}
  			for (i = 0; i < pols[pi]->xfrm_nr; i++)
  				tpp[ti++] = &pols[pi]->xfrm_vec[i];
  		}
  		xfrm_nr = ti;
  		if (npols > 1) {
  			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
  			tpp = stp;
  		}
  
  		/* For each tunnel xfrm, find the first matching tmpl.
  		 * For each tmpl before that, find corresponding xfrm.
  		 * Order is _important_. Later we will implement
  		 * some barriers, but at the moment barriers
  		 * are implied between each two transformations.
  		 */
  		for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
  			k = xfrm_policy_ok(tpp[i], sp, k, family);
  			if (k < 0) {
  				if (k < -1)
  					/* "-2 - errored_index" returned */
  					xerr_idx = -(2+k);
  				XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
  				goto reject;
  			}
  		}
  
  		if (secpath_has_nontransport(sp, k, &xerr_idx)) {
  			XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
  			goto reject;
  		}
  
  		xfrm_pols_put(pols, npols);
  		return 1;
  	}
  	XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
  
  reject:
  	xfrm_secpath_reject(xerr_idx, skb, &fl);
  reject_error:
  	xfrm_pols_put(pols, npols);
  	return 0;
  }
  EXPORT_SYMBOL(__xfrm_policy_check);
  
  int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
  {
  	struct net *net = dev_net(skb->dev);
  	struct flowi fl;
  	struct dst_entry *dst;
  	int res = 1;
  
  	if (xfrm_decode_session(skb, &fl, family) < 0) {
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
  		return 0;
  	}
  
  	skb_dst_force(skb);
  	if (!skb_dst(skb)) {
  		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
  		return 0;
  	}
  
  	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
  	if (IS_ERR(dst)) {
  		res = 0;
  		dst = NULL;
  	}
  	skb_dst_set(skb, dst);
  	return res;
  }
  EXPORT_SYMBOL(__xfrm_route_forward);
  
  /* Optimize later using cookies and generation ids. */
  
  static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
  {
  	/* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
  	 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
  	 * get validated by dst_ops->check on every use.  We do this
  	 * because when a normal route referenced by an XFRM dst is
  	 * obsoleted we do not go looking around for all parent
  	 * referencing XFRM dsts so that we can invalidate them.  It
  	 * is just too much work.  Instead we make the checks here on
  	 * every use.  For example:
  	 *
  	 *	XFRM dst A --> IPv4 dst X
  	 *
  	 * X is the "xdst->route" of A (X is also the "dst->path" of A
  	 * in this example).  If X is marked obsolete, "A" will not
  	 * notice.  That's what we are validating here via the
  	 * stale_bundle() check.
  	 *
  	 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
  	 * be marked on it.
  	 * This will force stale_bundle() to fail on any xdst bundle with
  	 * this dst linked in it.
  	 */
  	if (dst->obsolete < 0 && !stale_bundle(dst))
  		return dst;
  
  	return NULL;
  }
  
  static int stale_bundle(struct dst_entry *dst)
  {
  	return !xfrm_bundle_ok((struct xfrm_dst *)dst);
  }
  
  void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
  {
  	while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
  		dst->dev = dev_net(dev)->loopback_dev;
  		dev_hold(dst->dev);
  		dev_put(dev);
  	}
  }
  EXPORT_SYMBOL(xfrm_dst_ifdown);
  
  static void xfrm_link_failure(struct sk_buff *skb)
  {
  	/* Impossible. Such dst must be popped before reaches point of failure. */
  }
  
  static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
  {
  	if (dst) {
  		if (dst->obsolete) {
  			dst_release(dst);
  			dst = NULL;
  		}
  	}
  	return dst;
  }
  
  static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
  {
  	while (nr--) {
  		struct xfrm_dst *xdst = bundle[nr];
  		u32 pmtu, route_mtu_cached;
  		struct dst_entry *dst;
  
  		dst = &xdst->u.dst;
  		pmtu = dst_mtu(xfrm_dst_child(dst));
  		xdst->child_mtu_cached = pmtu;
  
  		pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
  
  		route_mtu_cached = dst_mtu(xdst->route);
  		xdst->route_mtu_cached = route_mtu_cached;
  
  		if (pmtu > route_mtu_cached)
  			pmtu = route_mtu_cached;
  
  		dst_metric_set(dst, RTAX_MTU, pmtu);
  	}
  }
  
  /* Check that the bundle accepts the flow and its components are
   * still valid.
   */
  
  static int xfrm_bundle_ok(struct xfrm_dst *first)
  {
  	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
  	struct dst_entry *dst = &first->u.dst;
  	struct xfrm_dst *xdst;
  	int start_from, nr;
  	u32 mtu;
  
  	if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
  	    (dst->dev && !netif_running(dst->dev)))
  		return 0;
  
  	if (dst->flags & DST_XFRM_QUEUE)
  		return 1;
  
  	start_from = nr = 0;
  	do {
  		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
  
  		if (dst->xfrm->km.state != XFRM_STATE_VALID)
  			return 0;
  		if (xdst->xfrm_genid != dst->xfrm->genid)
  			return 0;
  		if (xdst->num_pols > 0 &&
  		    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
  			return 0;
  
  		bundle[nr++] = xdst;
  
  		mtu = dst_mtu(xfrm_dst_child(dst));
  		if (xdst->child_mtu_cached != mtu) {
  			start_from = nr;
  			xdst->child_mtu_cached = mtu;
  		}
  
  		if (!dst_check(xdst->route, xdst->route_cookie))
  			return 0;
  		mtu = dst_mtu(xdst->route);
  		if (xdst->route_mtu_cached != mtu) {
  			start_from = nr;
  			xdst->route_mtu_cached = mtu;
  		}
  
  		dst = xfrm_dst_child(dst);
  	} while (dst->xfrm);
  
  	if (likely(!start_from))
  		return 1;
  
  	xdst = bundle[start_from - 1];
  	mtu = xdst->child_mtu_cached;
  	while (start_from--) {
  		dst = &xdst->u.dst;
  
  		mtu = xfrm_state_mtu(dst->xfrm, mtu);
  		if (mtu > xdst->route_mtu_cached)
  			mtu = xdst->route_mtu_cached;
  		dst_metric_set(dst, RTAX_MTU, mtu);
  		if (!start_from)
  			break;
  
  		xdst = bundle[start_from - 1];
  		xdst->child_mtu_cached = mtu;
  	}
  
  	return 1;
  }
  
  static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
  {
  	return dst_metric_advmss(xfrm_dst_path(dst));
  }
  
  static unsigned int xfrm_mtu(const struct dst_entry *dst)
  {
  	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
  
  	return mtu ? : dst_mtu(xfrm_dst_path(dst));
  }
  
  static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
  					const void *daddr)
  {
  	while (dst->xfrm) {
  		const struct xfrm_state *xfrm = dst->xfrm;
  
  		dst = xfrm_dst_child(dst);
  
  		if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
  			continue;
  		if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
  			daddr = xfrm->coaddr;
  		else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
  			daddr = &xfrm->id.daddr;
  	}
  	return daddr;
  }
  
  static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
  					   struct sk_buff *skb,
  					   const void *daddr)
  {
  	const struct dst_entry *path = xfrm_dst_path(dst);
  
  	if (!skb)
  		daddr = xfrm_get_dst_nexthop(dst, daddr);
  	return path->ops->neigh_lookup(path, skb, daddr);
  }
  
  static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
  {
  	const struct dst_entry *path = xfrm_dst_path(dst);
  
  	daddr = xfrm_get_dst_nexthop(dst, daddr);
  	path->ops->confirm_neigh(path, daddr);
  }
  
  int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
  {
  	int err = 0;
  
  	if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
  		return -EAFNOSUPPORT;
  
  	spin_lock(&xfrm_policy_afinfo_lock);
  	if (unlikely(xfrm_policy_afinfo[family] != NULL))
  		err = -EEXIST;
  	else {
  		struct dst_ops *dst_ops = afinfo->dst_ops;
  		if (likely(dst_ops->kmem_cachep == NULL))
  			dst_ops->kmem_cachep = xfrm_dst_cache;
  		if (likely(dst_ops->check == NULL))
  			dst_ops->check = xfrm_dst_check;
  		if (likely(dst_ops->default_advmss == NULL))
  			dst_ops->default_advmss = xfrm_default_advmss;
  		if (likely(dst_ops->mtu == NULL))
  			dst_ops->mtu = xfrm_mtu;
  		if (likely(dst_ops->negative_advice == NULL))
  			dst_ops->negative_advice = xfrm_negative_advice;
  		if (likely(dst_ops->link_failure == NULL))
  			dst_ops->link_failure = xfrm_link_failure;
  		if (likely(dst_ops->neigh_lookup == NULL))
  			dst_ops->neigh_lookup = xfrm_neigh_lookup;
  		if (likely(!dst_ops->confirm_neigh))
  			dst_ops->confirm_neigh = xfrm_confirm_neigh;
  		rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
  	}
  	spin_unlock(&xfrm_policy_afinfo_lock);
  
  	return err;
  }
  EXPORT_SYMBOL(xfrm_policy_register_afinfo);
  
  void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
  {
  	struct dst_ops *dst_ops = afinfo->dst_ops;
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
  		if (xfrm_policy_afinfo[i] != afinfo)
  			continue;
  		RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
  		break;
  	}
  
  	synchronize_rcu();
  
  	dst_ops->kmem_cachep = NULL;
  	dst_ops->check = NULL;
  	dst_ops->negative_advice = NULL;
  	dst_ops->link_failure = NULL;
  }
  EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
  
  void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
  {
  	spin_lock(&xfrm_if_cb_lock);
  	rcu_assign_pointer(xfrm_if_cb, ifcb);
  	spin_unlock(&xfrm_if_cb_lock);
  }
  EXPORT_SYMBOL(xfrm_if_register_cb);
  
  void xfrm_if_unregister_cb(void)
  {
  	RCU_INIT_POINTER(xfrm_if_cb, NULL);
  	synchronize_rcu();
  }
  EXPORT_SYMBOL(xfrm_if_unregister_cb);
  
  #ifdef CONFIG_XFRM_STATISTICS
  static int __net_init xfrm_statistics_init(struct net *net)
  {
  	int rv;
  	net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
  	if (!net->mib.xfrm_statistics)
  		return -ENOMEM;
  	rv = xfrm_proc_init(net);
  	if (rv < 0)
  		free_percpu(net->mib.xfrm_statistics);
  	return rv;
  }
  
  static void xfrm_statistics_fini(struct net *net)
  {
  	xfrm_proc_fini(net);
  	free_percpu(net->mib.xfrm_statistics);
  }
  #else
  static int __net_init xfrm_statistics_init(struct net *net)
  {
  	return 0;
  }
  
  static void xfrm_statistics_fini(struct net *net)
  {
  }
  #endif
  
  static int __net_init xfrm_policy_init(struct net *net)
  {
  	unsigned int hmask, sz;
  	int dir, err;
  
  	if (net_eq(net, &init_net)) {
  		xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
  					   sizeof(struct xfrm_dst),
  					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
  					   NULL);
  		err = rhashtable_init(&xfrm_policy_inexact_table,
  				      &xfrm_pol_inexact_params);
  		BUG_ON(err);
  	}
  
  	hmask = 8 - 1;
  	sz = (hmask+1) * sizeof(struct hlist_head);
  
  	net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
  	if (!net->xfrm.policy_byidx)
  		goto out_byidx;
  	net->xfrm.policy_idx_hmask = hmask;
  
  	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
  		struct xfrm_policy_hash *htab;
  
  		net->xfrm.policy_count[dir] = 0;
  		net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
  		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
  
  		htab = &net->xfrm.policy_bydst[dir];
  		htab->table = xfrm_hash_alloc(sz);
  		if (!htab->table)
  			goto out_bydst;
  		htab->hmask = hmask;
  		htab->dbits4 = 32;
  		htab->sbits4 = 32;
  		htab->dbits6 = 128;
  		htab->sbits6 = 128;
  	}
  	net->xfrm.policy_hthresh.lbits4 = 32;
  	net->xfrm.policy_hthresh.rbits4 = 32;
  	net->xfrm.policy_hthresh.lbits6 = 128;
  	net->xfrm.policy_hthresh.rbits6 = 128;
  
  	seqlock_init(&net->xfrm.policy_hthresh.lock);
  
  	INIT_LIST_HEAD(&net->xfrm.policy_all);
  	INIT_LIST_HEAD(&net->xfrm.inexact_bins);
  	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
  	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
  	return 0;
  
  out_bydst:
  	for (dir--; dir >= 0; dir--) {
  		struct xfrm_policy_hash *htab;
  
  		htab = &net->xfrm.policy_bydst[dir];
  		xfrm_hash_free(htab->table, sz);
  	}
  	xfrm_hash_free(net->xfrm.policy_byidx, sz);
  out_byidx:
  	return -ENOMEM;
  }
  
  static void xfrm_policy_fini(struct net *net)
  {
  	struct xfrm_pol_inexact_bin *b, *t;
  	unsigned int sz;
  	int dir;
  
  	flush_work(&net->xfrm.policy_hash_work);
  #ifdef CONFIG_XFRM_SUB_POLICY
  	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
  #endif
  	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
  
  	WARN_ON(!list_empty(&net->xfrm.policy_all));
  
  	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
  		struct xfrm_policy_hash *htab;
  
  		WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
  
  		htab = &net->xfrm.policy_bydst[dir];
  		sz = (htab->hmask + 1) * sizeof(struct hlist_head);
  		WARN_ON(!hlist_empty(htab->table));
  		xfrm_hash_free(htab->table, sz);
  	}
  
  	sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
  	WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
  	xfrm_hash_free(net->xfrm.policy_byidx, sz);
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
  		__xfrm_policy_inexact_prune_bin(b, true);
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  }
  
  static int __net_init xfrm_net_init(struct net *net)
  {
  	int rv;
  
  	/* Initialize the per-net locks here */
  	spin_lock_init(&net->xfrm.xfrm_state_lock);
  	spin_lock_init(&net->xfrm.xfrm_policy_lock);
  	mutex_init(&net->xfrm.xfrm_cfg_mutex);
  
  	rv = xfrm_statistics_init(net);
  	if (rv < 0)
  		goto out_statistics;
  	rv = xfrm_state_init(net);
  	if (rv < 0)
  		goto out_state;
  	rv = xfrm_policy_init(net);
  	if (rv < 0)
  		goto out_policy;
  	rv = xfrm_sysctl_init(net);
  	if (rv < 0)
  		goto out_sysctl;
  
  	return 0;
  
  out_sysctl:
  	xfrm_policy_fini(net);
  out_policy:
  	xfrm_state_fini(net);
  out_state:
  	xfrm_statistics_fini(net);
  out_statistics:
  	return rv;
  }
  
  static void __net_exit xfrm_net_exit(struct net *net)
  {
  	xfrm_sysctl_fini(net);
  	xfrm_policy_fini(net);
  	xfrm_state_fini(net);
  	xfrm_statistics_fini(net);
  }
  
  static struct pernet_operations __net_initdata xfrm_net_ops = {
  	.init = xfrm_net_init,
  	.exit = xfrm_net_exit,
  };
  
  void __init xfrm_init(void)
  {
  	register_pernet_subsys(&xfrm_net_ops);
  	xfrm_dev_init();
  	seqcount_mutex_init(&xfrm_policy_hash_generation, &hash_resize_mutex);
  	xfrm_input_init();
  
  #ifdef CONFIG_XFRM_ESPINTCP
  	espintcp_init();
  #endif
  
  	RCU_INIT_POINTER(xfrm_if_cb, NULL);
  	synchronize_rcu();
  }
  
  #ifdef CONFIG_AUDITSYSCALL
  static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
  					 struct audit_buffer *audit_buf)
  {
  	struct xfrm_sec_ctx *ctx = xp->security;
  	struct xfrm_selector *sel = &xp->selector;
  
  	if (ctx)
  		audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
  				 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
  
  	switch (sel->family) {
  	case AF_INET:
  		audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
  		if (sel->prefixlen_s != 32)
  			audit_log_format(audit_buf, " src_prefixlen=%d",
  					 sel->prefixlen_s);
  		audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
  		if (sel->prefixlen_d != 32)
  			audit_log_format(audit_buf, " dst_prefixlen=%d",
  					 sel->prefixlen_d);
  		break;
  	case AF_INET6:
  		audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
  		if (sel->prefixlen_s != 128)
  			audit_log_format(audit_buf, " src_prefixlen=%d",
  					 sel->prefixlen_s);
  		audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
  		if (sel->prefixlen_d != 128)
  			audit_log_format(audit_buf, " dst_prefixlen=%d",
  					 sel->prefixlen_d);
  		break;
  	}
  }
  
  void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
  {
  	struct audit_buffer *audit_buf;
  
  	audit_buf = xfrm_audit_start("SPD-add");
  	if (audit_buf == NULL)
  		return;
  	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
  	audit_log_format(audit_buf, " res=%u", result);
  	xfrm_audit_common_policyinfo(xp, audit_buf);
  	audit_log_end(audit_buf);
  }
  EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
  
  void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
  			      bool task_valid)
  {
  	struct audit_buffer *audit_buf;
  
  	audit_buf = xfrm_audit_start("SPD-delete");
  	if (audit_buf == NULL)
  		return;
  	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
  	audit_log_format(audit_buf, " res=%u", result);
  	xfrm_audit_common_policyinfo(xp, audit_buf);
  	audit_log_end(audit_buf);
  }
  EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
  #endif
  
  #ifdef CONFIG_XFRM_MIGRATE
  static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
  					const struct xfrm_selector *sel_tgt)
  {
  	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
  		if (sel_tgt->family == sel_cmp->family &&
  		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
  				    sel_cmp->family) &&
  		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
  				    sel_cmp->family) &&
  		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
  		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
  			return true;
  		}
  	} else {
  		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
  			return true;
  		}
  	}
  	return false;
  }
  
  static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
  						    u8 dir, u8 type, struct net *net)
  {
  	struct xfrm_policy *pol, *ret = NULL;
  	struct hlist_head *chain;
  	u32 priority = ~0U;
  
  	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
  	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
  	hlist_for_each_entry(pol, chain, bydst) {
  		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
  		    pol->type == type) {
  			ret = pol;
  			priority = ret->priority;
  			break;
  		}
  	}
  	chain = &net->xfrm.policy_inexact[dir];
  	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
  		if ((pol->priority >= priority) && ret)
  			break;
  
  		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
  		    pol->type == type) {
  			ret = pol;
  			break;
  		}
  	}
  
  	xfrm_pol_hold(ret);
  
  	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
  
  	return ret;
  }
  
  static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
  {
  	int match = 0;
  
  	if (t->mode == m->mode && t->id.proto == m->proto &&
  	    (m->reqid == 0 || t->reqid == m->reqid)) {
  		switch (t->mode) {
  		case XFRM_MODE_TUNNEL:
  		case XFRM_MODE_BEET:
  			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
  					    m->old_family) &&
  			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
  					    m->old_family)) {
  				match = 1;
  			}
  			break;
  		case XFRM_MODE_TRANSPORT:
  			/* in case of transport mode, template does not store
  			   any IP addresses, hence we just compare mode and
  			   protocol */
  			match = 1;
  			break;
  		default:
  			break;
  		}
  	}
  	return match;
  }
  
  /* update endpoint address(es) of template(s) */
  static int xfrm_policy_migrate(struct xfrm_policy *pol,
  			       struct xfrm_migrate *m, int num_migrate)
  {
  	struct xfrm_migrate *mp;
  	int i, j, n = 0;
  
  	write_lock_bh(&pol->lock);
  	if (unlikely(pol->walk.dead)) {
  		/* target policy has been deleted */
  		write_unlock_bh(&pol->lock);
  		return -ENOENT;
  	}
  
  	for (i = 0; i < pol->xfrm_nr; i++) {
  		for (j = 0, mp = m; j < num_migrate; j++, mp++) {
  			if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
  				continue;
  			n++;
  			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
  			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
  				continue;
  			/* update endpoints */
  			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
  			       sizeof(pol->xfrm_vec[i].id.daddr));
  			memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
  			       sizeof(pol->xfrm_vec[i].saddr));
  			pol->xfrm_vec[i].encap_family = mp->new_family;
  			/* flush bundles */
  			atomic_inc(&pol->genid);
  		}
  	}
  
  	write_unlock_bh(&pol->lock);
  
  	if (!n)
  		return -ENODATA;
  
  	return 0;
  }
  
  static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
  {
  	int i, j;
  
  	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
  		return -EINVAL;
  
  	for (i = 0; i < num_migrate; i++) {
  		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
  		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
  			return -EINVAL;
  
  		/* check if there is any duplicated entry */
  		for (j = i + 1; j < num_migrate; j++) {
  			if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
  				    sizeof(m[i].old_daddr)) &&
  			    !memcmp(&m[i].old_saddr, &m[j].old_saddr,
  				    sizeof(m[i].old_saddr)) &&
  			    m[i].proto == m[j].proto &&
  			    m[i].mode == m[j].mode &&
  			    m[i].reqid == m[j].reqid &&
  			    m[i].old_family == m[j].old_family)
  				return -EINVAL;
  		}
  	}
  
  	return 0;
  }
  
  int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
  		 struct xfrm_migrate *m, int num_migrate,
  		 struct xfrm_kmaddress *k, struct net *net,
  		 struct xfrm_encap_tmpl *encap)
  {
  	int i, err, nx_cur = 0, nx_new = 0;
  	struct xfrm_policy *pol = NULL;
  	struct xfrm_state *x, *xc;
  	struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
  	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
  	struct xfrm_migrate *mp;
  
  	/* Stage 0 - sanity checks */
  	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
  		goto out;
  
  	if (dir >= XFRM_POLICY_MAX) {
  		err = -EINVAL;
  		goto out;
  	}
  
  	/* Stage 1 - find policy */
  	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
  		err = -ENOENT;
  		goto out;
  	}
  
  	/* Stage 2 - find and update state(s) */
  	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
  		if ((x = xfrm_migrate_state_find(mp, net))) {
  			x_cur[nx_cur] = x;
  			nx_cur++;
  			xc = xfrm_state_migrate(x, mp, encap);
  			if (xc) {
  				x_new[nx_new] = xc;
  				nx_new++;
  			} else {
  				err = -ENODATA;
  				goto restore_state;
  			}
  		}
  	}
  
  	/* Stage 3 - update policy */
  	if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
  		goto restore_state;
  
  	/* Stage 4 - delete old state(s) */
  	if (nx_cur) {
  		xfrm_states_put(x_cur, nx_cur);
  		xfrm_states_delete(x_cur, nx_cur);
  	}
  
  	/* Stage 5 - announce */
  	km_migrate(sel, dir, type, m, num_migrate, k, encap);
  
  	xfrm_pol_put(pol);
  
  	return 0;
  out:
  	return err;
  
  restore_state:
  	if (pol)
  		xfrm_pol_put(pol);
  	if (nx_cur)
  		xfrm_states_put(x_cur, nx_cur);
  	if (nx_new)
  		xfrm_states_delete(x_new, nx_new);
  
  	return err;
  }
  EXPORT_SYMBOL(xfrm_migrate);
  #endif
  