diff --git a/tetheroffload/control/1.0/IOffloadControl.hal b/tetheroffload/control/1.0/IOffloadControl.hal
new file mode 100644
index 0000000..334f4ca
--- /dev/null
+++ b/tetheroffload/control/1.0/IOffloadControl.hal
@@ -0,0 +1,221 @@
+/*
+ * 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);
+};