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      1 //
      2 // Copyright (C) 2012 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 "shill/wifi/callback80211_metrics.h"
     18 
     19 #include <string>
     20 
     21 #include "shill/logging.h"
     22 #include "shill/metrics.h"
     23 #include "shill/net/ieee80211.h"
     24 #include "shill/net/netlink_manager.h"
     25 #include "shill/net/nl80211_message.h"
     26 
     27 using std::string;
     28 
     29 namespace shill {
     30 
     31 namespace Logging {
     32 static auto kModuleLogScope = ScopeLogger::kWiFi;
     33 static string ObjectID(const Callback80211Metrics* c) {
     34   return "(callback80211metrics)";
     35 }
     36 }
     37 
     38 Callback80211Metrics::Callback80211Metrics(Metrics* metrics)
     39     : metrics_(metrics) {}
     40 
     41 IEEE_80211::WiFiReasonCode Callback80211Metrics::WiFiReasonCodeFromUint16(
     42     uint16_t reason) const {
     43   IEEE_80211::WiFiReasonCode reason_enum = IEEE_80211::kReasonCodeInvalid;
     44   if (reason == IEEE_80211::kReasonCodeReserved0 ||
     45       reason == IEEE_80211::kReasonCodeReserved12 ||
     46       (reason >= IEEE_80211::kReasonCodeReservedBegin25 &&
     47        reason <= IEEE_80211::kReasonCodeReservedEnd31) ||
     48       (reason >= IEEE_80211::kReasonCodeReservedBegin40 &&
     49        reason <= IEEE_80211::kReasonCodeReservedEnd44) ||
     50       reason >= IEEE_80211::kReasonCodeMax) {
     51     SLOG(this, 1) << "Invalid reason code in disconnect message";
     52     reason_enum = IEEE_80211::kReasonCodeInvalid;
     53   } else {
     54     reason_enum = static_cast<IEEE_80211::WiFiReasonCode>(reason);
     55   }
     56   return reason_enum;
     57 }
     58 
     59 void Callback80211Metrics::CollectDisconnectStatistics(
     60     const NetlinkMessage& netlink_message) {
     61   if (!metrics_) {
     62     return;
     63   }
     64   // We only handle disconnect and deauthenticate messages, both of which are
     65   // nl80211 messages.
     66   if (netlink_message.message_type() != Nl80211Message::GetMessageType()) {
     67     return;
     68   }
     69   const Nl80211Message& message =
     70       * reinterpret_cast<const Nl80211Message*>(&netlink_message);
     71 
     72   // Station-instigated disconnects provide their information in the
     73   // deauthenticate message but AP-instigated disconnects provide it in the
     74   // disconnect message.
     75   uint16_t reason = IEEE_80211::kReasonCodeUnspecified;
     76   if (message.command() == DeauthenticateMessage::kCommand) {
     77     SLOG(this, 3) << "Handling Deauthenticate Message";
     78     message.Print(3, 3);
     79     // If there's no frame, this is probably an AP-caused disconnect and
     80     // there'll be a disconnect message to tell us about that.
     81     ByteString rawdata;
     82     if (!message.const_attributes()->GetRawAttributeValue(NL80211_ATTR_FRAME,
     83                                                           &rawdata)) {
     84       SLOG(this, 5) << "No frame in deauthenticate message, ignoring";
     85       return;
     86     }
     87     Nl80211Frame frame(rawdata);
     88     reason = frame.reason();
     89   } else if (message.command() == DisconnectMessage::kCommand) {
     90     SLOG(this, 3) << "Handling Disconnect Message";
     91     message.Print(3, 3);
     92     // If there's no reason code, this is probably a STA-caused disconnect and
     93     // there was be a disconnect message to tell us about that.
     94     if (!message.const_attributes()->GetU16AttributeValue(
     95             NL80211_ATTR_REASON_CODE, &reason)) {
     96       SLOG(this, 5) << "No reason code in disconnect message, ignoring";
     97       return;
     98     }
     99   } else {
    100     return;
    101   }
    102 
    103   IEEE_80211::WiFiReasonCode reason_enum = WiFiReasonCodeFromUint16(reason);
    104 
    105   Metrics::WiFiDisconnectByWhom by_whom =
    106       message.const_attributes()->IsFlagAttributeTrue(
    107           NL80211_ATTR_DISCONNECTED_BY_AP) ? Metrics::kDisconnectedByAp :
    108           Metrics::kDisconnectedNotByAp;
    109   SLOG(this, 1) << "Notify80211Disconnect by " << (by_whom ? "station" : "AP")
    110                 << " because:" << reason_enum;
    111   metrics_->Notify80211Disconnect(by_whom, reason_enum);
    112 }
    113 
    114 }  // namespace shill.
    115