1 files changed, 100 insertions, 122 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index b22767c0c078..914bac03b52a 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -110,7 +110,11 @@ struct xfrm_pol_inexact_node {
  * 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.
+ * the lowest priority.  If two candidates have the same priority, the
+ * struct xfrm_policy pos member with the lower number is used.
+ *
+ * This replicates previous single-list-search algorithm which would
+ * return first matching policy in the (ordered-by-priority) list.
  */
 
 struct xfrm_pol_inexact_key {
@@ -197,8 +201,6 @@ xfrm_policy_inexact_lookup_rcu(struct net *net,
 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,
@@ -411,7 +413,6 @@ struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t 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);
@@ -1229,26 +1230,31 @@ xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
 		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 bool xfrm_policy_is_dead_or_sk(const struct xfrm_policy *policy)
+{
+	int dir;
+
+	if (policy->walk.dead)
+		return true;
+
+	dir = xfrm_policy_id2dir(policy->index);
+	return dir >= XFRM_POLICY_MAX;
+}
+
 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;
@@ -1275,13 +1281,10 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 		struct xfrm_pol_inexact_bin *bin;
 		u8 dbits, sbits;
 
-		if (policy->walk.dead)
+		if (xfrm_policy_is_dead_or_sk(policy))
 			continue;
 
 		dir = xfrm_policy_id2dir(policy->index);
-		if (dir >= XFRM_POLICY_MAX)
-			continue;
-
 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
 			if (policy->family == AF_INET) {
 				dbits = rbits4;
@@ -1312,23 +1315,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 			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;
@@ -1346,14 +1333,13 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 
 	/* re-insert all policies by order of creation */
 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
-		if (policy->walk.dead)
+		if (xfrm_policy_is_dead_or_sk(policy))
 			continue;
-		dir = xfrm_policy_id2dir(policy->index);
-		if (dir >= XFRM_POLICY_MAX) {
-			/* skip socket policies */
-			continue;
-		}
+
+		hlist_del_rcu(&policy->bydst);
+
 		newpos = NULL;
+		dir = xfrm_policy_id2dir(policy->index);
 		chain = policy_hash_bysel(net, &policy->selector,
 					  policy->family, dir);
 
@@ -1520,42 +1506,6 @@ static const struct rhashtable_params xfrm_pol_inexact_params = {
 	.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 && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
-		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)
@@ -2295,10 +2245,52 @@ out:
 	return pol;
 }
 
+static u32 xfrm_gen_pos_slow(struct net *net)
+{
+	struct xfrm_policy *policy;
+	u32 i = 0;
+
+	/* oldest entry is last in list */
+	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
+		if (!xfrm_policy_is_dead_or_sk(policy))
+			policy->pos = ++i;
+	}
+
+	return i;
+}
+
+static u32 xfrm_gen_pos(struct net *net)
+{
+	const struct xfrm_policy *policy;
+	u32 i = 0;
+
+	/* most recently added policy is at the head of the list */
+	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
+		if (xfrm_policy_is_dead_or_sk(policy))
+			continue;
+
+		if (policy->pos == UINT_MAX)
+			return xfrm_gen_pos_slow(net);
+
+		i = policy->pos + 1;
+		break;
+	}
+
+	return i;
+}
+
 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
 {
 	struct net *net = xp_net(pol);
 
+	switch (dir) {
+	case XFRM_POLICY_IN:
+	case XFRM_POLICY_FWD:
+	case XFRM_POLICY_OUT:
+		pol->pos = xfrm_gen_pos(net);
+		break;
+	}
+
 	list_add(&pol->walk.all, &net->xfrm.policy_all);
 	net->xfrm.policy_count[dir]++;
 	xfrm_pol_hold(pol);
@@ -2315,7 +2307,6 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 	/* 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);
 	}
 
@@ -4438,63 +4429,50 @@ 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, u32 if_id)
 {
-	struct xfrm_policy *pol, *ret = NULL;
-	struct hlist_head *chain;
-	u32 priority = ~0U;
+	struct xfrm_policy *pol;
+	struct flowi fl;
 
-	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 ((if_id == 0 || pol->if_id == if_id) &&
-		    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;
+	memset(&fl, 0, sizeof(fl));
 
-		if ((if_id == 0 || pol->if_id == if_id) &&
-		    xfrm_migrate_selector_match(sel, &pol->selector) &&
-		    pol->type == type) {
-			ret = pol;
+	fl.flowi_proto = sel->proto;
+
+	switch (sel->family) {
+	case AF_INET:
+		fl.u.ip4.saddr = sel->saddr.a4;
+		fl.u.ip4.daddr = sel->daddr.a4;
+		if (sel->proto == IPSEC_ULPROTO_ANY)
 			break;
-		}
+		fl.u.flowi4_oif = sel->ifindex;
+		fl.u.ip4.fl4_sport = sel->sport;
+		fl.u.ip4.fl4_dport = sel->dport;
+		break;
+	case AF_INET6:
+		fl.u.ip6.saddr = sel->saddr.in6;
+		fl.u.ip6.daddr = sel->daddr.in6;
+		if (sel->proto == IPSEC_ULPROTO_ANY)
+			break;
+		fl.u.flowi6_oif = sel->ifindex;
+		fl.u.ip6.fl4_sport = sel->sport;
+		fl.u.ip6.fl4_dport = sel->dport;
+		break;
+	default:
+		return ERR_PTR(-EAFNOSUPPORT);
 	}
 
-	xfrm_pol_hold(ret);
+	rcu_read_lock();
 
-	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	pol = xfrm_policy_lookup_bytype(net, type, &fl, sel->family, dir, if_id);
+	if (IS_ERR_OR_NULL(pol))
+		goto out_unlock;
 
-	return ret;
+	if (!xfrm_pol_hold_rcu(pol))
+		pol = NULL;
+out_unlock:
+	rcu_read_unlock();
+	return pol;
 }
 
 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
@@ -4631,9 +4609,9 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 
 	/* Stage 1 - find policy */
 	pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id);
-	if (!pol) {
+	if (IS_ERR_OR_NULL(pol)) {
 		NL_SET_ERR_MSG(extack, "Target policy not found");
-		err = -ENOENT;
+		err = IS_ERR(pol) ? PTR_ERR(pol) : -ENOENT;
 		goto out;
 	}