store: added IPStore and memory implementation

server/store/ip_store.go

@@ -0,0 +1,79 @@
+// Copyright 2016 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+package store
+
+import (
+	"fmt"
+	"net"
+)
+
+var ipStoreDrivers = make(map[string]IPStoreDriver)
+
+// IPStore represents an interface for manipulating IPs and IP ranges.
+type IPStore interface {
+	// AddIP adds a single IP address to the IPStore.
+	AddIP(ip net.IP) error
+
+	// AddNetwork adds a range of IP addresses, denoted by a network in CIDR
+	// notation, to the IPStore.
+	AddNetwork(network string) error
+
+	// HasIP returns whether the given IP address is contained in the IPStore
+	// or belong to any of the stored networks.
+	HasIP(ip net.IP) (bool, error)
+
+	// HasAnyIP returns whether any of the given IP addresses are contained in
+	// the IPStore or belong to any of the stored networks.
+	HasAnyIP(ips []net.IP) (bool, error)
+
+	// HassAllIPs returns whether all of the given IP addresses are contained in
+	// the IPStore or belong to any of the stored networks.
+	HasAllIPs(ips []net.IP) (bool, error)
+
+	// RemoveIP removes a single IP address from the IPStore.
+	//
+	// This wil not remove the given address from any networks it belongs to
+	// that are stored in the IPStore.
+	RemoveIP(ip net.IP) error
+
+	// RemoveNetwork removes a range of IP addresses that was previously added
+	// through AddNetwork.
+	//
+	// The given network must not, as a string, match the previously added
+	// network, but rather denote the same network, e.g. if the network
+	// 192.168.22.255/24 was added, removing the network 192.168.22.123/24
+	// will succeed.
+	RemoveNetwork(network string) error
+}
+
+// IPStoreDriver represents an interface for creating a handle to the
+// storage of IPs.
+type IPStoreDriver interface {
+	New(*Config) (IPStore, error)
+}
+
+// RegisterIPStoreDriver makes a driver available by the provided name.
+//
+// If this function is called twice with the same name or if the driver is nil,
+// it panics.
+func RegisterIPStoreDriver(name string, driver IPStoreDriver) {
+	if driver == nil {
+		panic("store: could not register nil ClientStoreDriver")
+	}
+	if _, dup := ipStoreDrivers[name]; dup {
+		panic("store: could not register duplicate ClientStoreDriver: " + name)
+	}
+	ipStoreDrivers[name] = driver
+}
+
+// OpenIPStore returns an IPStore specified by a configuration.
+func OpenIPStore(cfg *Config) (IPStore, error) {
+	driver, ok := ipStoreDrivers[cfg.IPStore]
+	if !ok {
+		return nil, fmt.Errorf("store: unknown driver %q (forgotten import?)", cfg.IPStore)
+	}
+
+	return driver.New(cfg)
+}