Revert "xfrm: switch migrate to xfrm_policy_lookup_bytype"

This reverts commit 563d5ca.

Bug: 367633876
Signed-off-by: Terence Tritton <[email protected]>
Change-Id: Ib9fe7365c56dab3f7f99f12a48d5d14e3fbf06ae

Author: Terence Tritton

net/xfrm/xfrm_policy.c

@@ -1257,10 +1257,13 @@ 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;
@@ -1321,7 +1324,23 @@ 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;
@@ -4467,50 +4486,63 @@ 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;
-	struct flowi fl;
-
-	memset(&fl, 0, sizeof(fl));
-
-	fl.flowi_proto = sel->proto;
+	struct xfrm_policy *pol, *ret = NULL;
+	struct hlist_head *chain;
+	u32 priority = ~0U;
 
-	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)
+	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;
-		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)
+		}
+	}
+	chain = &net->xfrm.policy_inexact[dir];
+	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
+		if ((pol->priority >= priority) && ret)
 			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);
+
+		if ((if_id == 0 || pol->if_id == if_id) &&
+		    xfrm_migrate_selector_match(sel, &pol->selector) &&
+		    pol->type == type) {
+			ret = pol;
+			break;
+		}
 	}
 
-	rcu_read_lock();
+	xfrm_pol_hold(ret);
 
-	pol = xfrm_policy_lookup_bytype(net, type, &fl, sel->family, dir, if_id);
-	if (IS_ERR_OR_NULL(pol))
-		goto out_unlock;
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
-	if (!xfrm_pol_hold_rcu(pol))
-		pol = NULL;
-out_unlock:
-	rcu_read_unlock();
-	return pol;
+	return ret;
 }
 
 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
@@ -4647,9 +4679,9 @@ 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 (IS_ERR_OR_NULL(pol)) {
+	if (!pol) {
 		NL_SET_ERR_MSG(extack, "Target policy not found");
-		err = IS_ERR(pol) ? PTR_ERR(pol) : -ENOENT;
+		err = -ENOENT;
 		goto out;
 	}