1 // Copyright 2012 Google, Inc. All rights reserved.
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the LICENSE file in the root of the source
13 // Router implements simple IPv4/IPv6 routing based on the kernel's routing
14 // table. This routing library has very few features and may actually route
15 // incorrectly in some cases, but it should work the majority of the time.
16 type Router interface {
17 // Route returns where to route a packet based on the packet's source
18 // and destination IP address.
20 // Callers may pass in nil for src, in which case the src is treated as
21 // either 0.0.0.0 or ::, depending on whether dst is a v4 or v6 address.
23 // It returns the interface on which to send the packet, the gateway IP
24 // to send the packet to (if necessary), the preferred src IP to use (if
25 // available). If the preferred src address is not given in the routing
26 // table, the first IP address of the interface is provided.
28 // If an error is encountered, iface, geteway, and
29 // preferredSrc will be nil, and err will be set.
30 Route(dst net.IP) (iface *net.Interface, gateway, preferredSrc net.IP, err error)
32 // RouteWithSrc routes based on source information as well as destination
33 // information. Either or both of input/src can be nil. If both are, this
34 // should behave exactly like Route(dst)
35 RouteWithSrc(input net.HardwareAddr, src, dst net.IP) (iface *net.Interface, gateway, preferredSrc net.IP, err error)