1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <libnl++/generic/FamilyTracker.h> 18 19 #include <android-base/logging.h> 20 21 // should be in linux/genetlink.h 22 #define GENL_START_ALLOC (NLMSG_MIN_TYPE + 3) 23 24 namespace android::nl::generic { 25 track(const Buffer<nlmsghdr> & buffer)26bool FamilyTracker::track(const Buffer<nlmsghdr>& buffer) { 27 const auto msgMaybe = nl::Message<genlmsghdr>::parse(buffer, {GENL_ID_CTRL}); 28 if (!msgMaybe.has_value()) return false; 29 30 const auto msg = *msgMaybe; 31 if (msg->cmd != CTRL_CMD_NEWFAMILY) return true; 32 33 const auto familyName = msg.attributes.get<std::string>(CTRL_ATTR_FAMILY_NAME); 34 const auto familyId = msg.attributes.get<uint16_t>(CTRL_ATTR_FAMILY_ID); 35 36 // TODO(224845900): NETLINK_GENERIC == 16, and (erroneously?) sets off this warning 37 if (familyId < GENL_START_ALLOC) { 38 LOG(WARNING) << "Invalid family ID: " << familyId; 39 return true; 40 } 41 42 if (familyName == "nl80211") mNl80211FamilyId = familyId; 43 44 return true; 45 } 46 parseNl80211(Buffer<nlmsghdr> msg)47std::optional<Message<genlmsghdr>> FamilyTracker::parseNl80211(Buffer<nlmsghdr> msg) { 48 if (track(msg)) return std::nullopt; 49 if (!mNl80211FamilyId.has_value()) return std::nullopt; 50 51 return nl::Message<genlmsghdr>::parse(msg, {*mNl80211FamilyId}); 52 } 53 54 } // namespace android::nl::generic 55