/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.hardware.tetheroffload.control@1.0;
import ITetheringOffloadCallback;
/**
* Interface used to control the lifecycle of tethering offload
*/
interface IOffloadControl {
/**
* Indicates intent to start offload for tethering in immediate future.
*
* This API must be called exactly once the first time that Tethering is requested by
* the user.
*
* If this API is called multiple times without first calling stopOffload, then the subsequent
* calls must fail without changing the state of the server.
*
* If for some reason, the hardware is currently unable to support offload, this call must fail.
*
* @param cb Assuming success, this callback must provide unsolicited updates of offload status.
* It is assumed to be valid until stopOffload is called.
*
* @return success true if initialization is successful, false otherwise
* @return errMsg a human readable string if eror has occured.
*
* Remarks: Initializing offload does not imply that any upstreams or downstreams have yet been,
* or even will be, chosen. This API is symmetrical with stopOffload.
*/
@entry
@callflow(next={"*"})
initOffload(ITetheringOffloadCallback cb) generates (bool success, string errMsg);
/**
* Indicate desire to tear down all tethering offload.
*
* Called after tethering is no longer requested by the user. Any remaining offload must
* be subsequently torn down by the management process. Upon success, the callback registered
* in initOffload must be released, and offload must be stopped.
*
* @return success true if offload is stopped, false otherwise
* @return errMsg a human readable string if eror has occured.
*
* Remarks: Statistics must be reset by this API.
*/
@exit
stopOffload() generates (bool success, string errMsg);
/**
* Instruct management process not to forward traffic destined to or from the specified prefixes.
*
* This API may only be called after initOffload and before stopOffload.
*
* @param prefixes List containing fully specified prefixes. For e.g. 192.168.1.12/24
or 2001:4860:0684:0:0:0:0:0:1002/64
*
* @return success true if success, false otherwise
* @return errMsg a human readable string if eror has occured.
*
* Remarks: This list overrides any previously specified list
*/
setLocalPrefixes(vec<string> prefixes) generates (bool success, string errMsg);
/**
* Query offloaded traffic statistics forwarded to an upstream address.
*
* Return statistics that have transpired since the last query. This would include
* statistics from all offloaded downstream tether interfaces that have been forwarded to this
* upstream interface. After returning the statistics, the counters are reset to zero.
*
* Only offloaded statistics must be returned by this API, software stats must not be
* returned.
*
* @param upstream Upstream interface on which traffic exited/entered
*
* @return rxBytes values depicting the received bytes
* @return txBytes values depicting the transmitted bytes
*/
getForwardedStats(string upstream) generates (uint64_t rxBytes, uint64_t txBytes);
/**
* Instruct hardware to stop forwarding traffic and send a callback after limit bytes have been
* transferred in either direction on this upstream interface.
*
* The limit must be applied to all traffic on the given upstream interface. This
* includes hardware forwarded traffic, software forwarded traffic, and AP-originated traffic.
* IPv4 and IPv6 traffic both count towards the same limit. IP headers are included in the
* byte count limit, but, link-layer headers are not.
*
* This API may only be called while offload is occurring on this upstream. The hardware
* management process is not expected to cache the value and apply the quota once offload is
* started. This cache is not expected, because the limit value would likely become stale over
* time and would not reflect any new traffic that has occurred.
*
* This limit must replace any previous limit. It may be interpreted as "tell me when
* <limit> bytes have been transferred (in either direction) on <upstream>, starting
* now and counting from zero."
*
* Once the limit is reached, the callback registered in initOffload must be called to indicate
* this event and all offload must be stopped. If offload is desired again, the hardware
* management process must be completely reprogrammed by calling setUpstreamParameters and
* addDownstream again. Note that it is not necessary to call initOffload again to resume offload
* if stopOffload was not called by the client.
*
* @param upstream Upstream interface name that limit must apply to
* @param limit Bytes limit that can occur before action must be taken
*
* @return success true if limit is applied, false otherwise
* @return errMsg a human readable string if eror has occured.
*/
setDataLimit(string upstream, uint64_t limit) generates (bool success, string errMsg);
/**
* Instruct hardware to start forwarding traffic to the specified upstream.
*
* When iface, v4Addr, and v4Gw are all non-null, the management process may begin forwarding
* any currently configured or future configured IPv4 downstreams to this upstream interface.
*
* If any of the previously three mentioned parameters are null, then any current IPv4 offload
* must be stopped.
*
* When iface and v6Gws are both non-null, and in the case of v6Gws, are not empty, the
* management process may begin forwarding any currently configured or future configured IPv6
* downstreams to this upstream interface.
*
* If either of the two above parameters are null, or no V6 Gateways are provided, then IPv6
* offload must be stopped.
*
* This API may only be called after initOffload and before stopOffload.
*
* @param iface Upstream interface name. Note that only one is needed because IPv4 and IPv6
* interfaces cannot be different (only known that this can occur during software
* xlat, which cannot be offloaded through hardware anyways). If the iface is
* null, offload must be stopped.
* @param v4Addr The local IPv4 address assigned to the provided upstream interface, i.e. the
* IPv4 address the packets are NATed to. For e.g. 192.168.1.12.
* @param v4Gw The IPv4 address of the IPv4 gateway on the upstream interface.
* For e.g. 192.168.1.1
* @param v6Gws A list of IPv6 addresses (for e.g. 2001:4860:0684:0:0:0:0:0:1002) for possible
* IPv6 gateways on the upstream interface.
*
* @return success true if success, false otherwise
* @return errMsg a human readable string if eror has occured.
*
* Remarks: This overrides any previously configured parameters.
*/
setUpstreamParameters(string iface, string v4Addr, string v4Gw, vec<string> v6Gws)
generates (bool success, string errMsg);
/**
* Configure a downstream interface and prefix in the hardware management process that may be
* forwarded.
*
* The prefix may be an IPv4 or an IPv6 address to signify which family can be offloaded from the
* specified tether interface. The list of IPv4 and IPv6 downstreams that are configured may
* differ.
*
* If the given protocol, as determined by the prefix, has an upstream set,
* the hardware may begin forwarding traffic between the upstream and any devices on the
* downstream interface that have IP addresses within the specified prefix. Traffic from the same
* downstream interfaces is unaffected and must be forwarded if and only if it was already
* being forwarded.
*
* If no upstream is currently configured, then these downstream interface and prefixes must be
* preserved so that offload may begin in the future when an upstream is set.
*
* This API does not replace any previously configured downstreams and must be explictly removed
* by calling removeDownstream.
*
* This API may only be called after initOffload and before stopOffload.
*
* @param iface Tether interface
* @param prefix Downstream prefix depicting addresses that may be offloaded.
* For e.g. 192.168.1.12/24 or 2001:4860:0684::/64)
*
* @return success true if success, false otherwise
* @return errMsg a human readable string if eror has occured.
*
* Remarks: The hardware management process may fail this call in a normal situation. This can
* happen because the hardware cannot support the current number of prefixes, the
* hardware cannot support concurrent offload on multiple interfaces, the hardware
* cannot currently support offload on the tether interface for some reason, or any
* other dynamic configuration issues which may occur. In this case,
* traffic must remain unaffected and must be forwarded if and only if it was already
* being forwarded.
*/
addDownstream(string iface, string prefix) generates (bool success, string errMsg);
/**
* Remove a downstream prefix that may be forwarded from the hardware management process.
*
* The prefix may be an IPv4 or an IPv6 address. If it was not previously configured using
* addDownstream, then this must be a no-op.
*
* This API may only be called after initOffload and before stopOffload.
*
* @param iface Tether interface
* @param prefix Downstream prefix depicting address that must no longer be offloaded
* For e.g. 192.168.1.12/24 or 2001:4860:0684::/64)
*
* @return success true if success, false otherwise
* @return errMsg a human readable string if eror has occured.
*/
removeDownstream(string iface, string prefix) generates (bool success, string errMsg);
};