ila: Flush netlink command to clear xlat table

Add ILA_CMD_FLUSH netlink command to clear the ILA translation table.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/ila.h

@@ -30,6 +30,7 @@ enum {
 	ILA_CMD_ADD,
 	ILA_CMD_DEL,
 	ILA_CMD_GET,
+	ILA_CMD_FLUSH,
 
 	__ILA_CMD_MAX,
 };

net/ipv6/ila/ila.h

@@ -123,6 +123,7 @@ void ila_xlat_exit_net(struct net *net);
 int ila_xlat_nl_cmd_add_mapping(struct sk_buff *skb, struct genl_info *info);
 int ila_xlat_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info);
 int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info);
+int ila_xlat_nl_cmd_flush(struct sk_buff *skb, struct genl_info *info);
 int ila_xlat_nl_dump_start(struct netlink_callback *cb);
 int ila_xlat_nl_dump_done(struct netlink_callback *cb);
 int ila_xlat_nl_dump(struct sk_buff *skb, struct netlink_callback *cb);

net/ipv6/ila/ila_main.c

@@ -26,6 +26,12 @@ static const struct genl_ops ila_nl_ops[] = {
 		.policy = ila_nl_policy,
 		.flags = GENL_ADMIN_PERM,
 	},
+	{
+		.cmd = ILA_CMD_FLUSH,
+		.doit = ila_xlat_nl_cmd_flush,
+		.policy = ila_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
 	{
 		.cmd = ILA_CMD_GET,
 		.doit = ila_xlat_nl_cmd_get_mapping,

net/ipv6/ila/ila_xlat.c

@@ -164,9 +164,9 @@ static inline void ila_release(struct ila_map *ila)
 	kfree_rcu(ila, rcu);
 }
 
-static void ila_free_cb(void *ptr, void *arg)
+static void ila_free_node(struct ila_map *ila)
 {
-	struct ila_map *ila = (struct ila_map *)ptr, *next;
+	struct ila_map *next;
 
 	/* Assume rcu_readlock held */
 	while (ila) {
@@ -176,6 +176,11 @@ static void ila_free_cb(void *ptr, void *arg)
 	}
 }
 
+static void ila_free_cb(void *ptr, void *arg)
+{
+	ila_free_node((struct ila_map *)ptr);
+}
+
 static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila);
 
 static unsigned int
@@ -365,6 +370,59 @@ int ila_xlat_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
+static inline spinlock_t *lock_from_ila_map(struct ila_net *ilan,
+					    struct ila_map *ila)
+{
+	return ila_get_lock(ilan, ila->xp.ip.locator_match);
+}
+
+int ila_xlat_nl_cmd_flush(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct rhashtable_iter iter;
+	struct ila_map *ila;
+	spinlock_t *lock;
+	int ret;
+
+	ret = rhashtable_walk_init(&ilan->xlat.rhash_table, &iter, GFP_KERNEL);
+	if (ret)
+		goto done;
+
+	rhashtable_walk_start(&iter);
+
+	for (;;) {
+		ila = rhashtable_walk_next(&iter);
+
+		if (IS_ERR(ila)) {
+			if (PTR_ERR(ila) == -EAGAIN)
+				continue;
+			ret = PTR_ERR(ila);
+			goto done;
+		} else if (!ila) {
+			break;
+		}
+
+		lock = lock_from_ila_map(ilan, ila);
+
+		spin_lock(lock);
+
+		ret = rhashtable_remove_fast(&ilan->xlat.rhash_table,
+					     &ila->node, rht_params);
+		if (!ret)
+			ila_free_node(ila);
+
+		spin_unlock(lock);
+
+		if (ret)
+			break;
+	}
+
+done:
+	rhashtable_walk_stop(&iter);
+	return ret;
+}
+
 static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
 {
 	if (nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR,