鸿蒙 WiFi 扫描流程（2）

接着上篇没有记录完的，我们继续梳理，需要上一篇做基础的请看：鸿蒙 WiFi 扫描流程（1）
上一篇我们讲到 scan_service.cpp 里面的 SingleScan 方法，继续这个方法往下看：

// foundation/communication/wifi/wifi/services/wifi_standard/wifi_framework/wifi_manage/wifi_scan/scan_service.cppbool ScanService::SingleScan(ScanConfig &scanConfig)
{WIFI_LOGI("Enter ScanService::SingleScan.\n");#ifndef OHOS_ARCH_LITEif (!standByListerner.AllowScan()) {WIFI_LOGE("Scan not allowed when device in standby state.\n");return WIFI_OPT_FAILED;}
#endifGetAllowBandFreqsControlInfo(scanConfig.scanBand, scanConfig.scanFreqs);                   ---> 哪个Bandif ((scanConfig.scanBand == SCAN_BAND_UNSPECIFIED) && (scanConfig.scanFreqs.empty())) {WIFI_LOGE("Have no allowed band or freq.\n");return false;}InterScanConfig interConfig;interConfig.fullScanFlag = scanConfig.fullScanFlag;interConfig.hiddenNetworkSsid.assign(scanConfig.hiddenNetworkSsid.begin(), scanConfig.hiddenNetworkSsid.end());interConfig.scanStyle = scanConfig.scanStyle;/* Specified frequency */if (scanConfig.scanBand == SCAN_BAND_UNSPECIFIED) {interConfig.scanFreqs.assign(scanConfig.scanFreqs.begin(), scanConfig.scanFreqs.end());/** When band is SCAN_BAND_BOTH_WITH_DFS, need to scan all frequency,* scanFreqs can be empty.*/} else if (scanConfig.scanBand != SCAN_BAND_BOTH_WITH_DFS) {/* Converting frequency bands to frequencies. */if (!GetBandFreqs(scanConfig.scanBand, interConfig.scanFreqs)) {WIFI_LOGE("GetBandFreqs failed.\n");return false;}}/* Save the configuration. */int requestIndex = StoreRequestScanConfig(scanConfig, interConfig);if (requestIndex == MAX_SCAN_CONFIG_STORE_INDEX) {WIFI_LOGE("StoreRequestScanConfig failed.\n");return false;}std::unique_lock<std::mutex> lock(scanConfigMapMutex);if (pScanStateMachine == nullptr) {WIFI_LOGE("pScanStateMachine is null.\n");return false;}/* Construct a message. */   // 去状态机里面处理这个消息InternalMessage *interMessage =pScanStateMachine->CreateMessage(static_cast<int>(CMD_START_COMMON_SCAN), requestIndex);if (interMessage == nullptr) {scanConfigMap.erase(requestIndex);WIFI_LOGE("CreateMessage failed.\n");return false;}if (!AddScanMessageBody(interMessage, interConfig)) {scanConfigMap.erase(requestIndex);MessageManage::GetInstance().ReclaimMsg(interMessage);WIFI_LOGE("AddScanMessageBody failed.\n");return false;}pScanStateMachine->SendMessage(interMessage);return true;
}//foundation/communication/wifi/wifi/services/wifi_standard/wifi_framework/wifi_manage/wifi_scan/scan_state_machine.cpp
bool ScanStateMachine::HardwareReady::ExecuteStateMsg(InternalMessage *msg)
{WIFI_LOGI("ScanStateMachine::HardwareReady::ExecuteStateMsg.\n");if (msg == nullptr) {WIFI_LOGE("msg is null.\n");return true;}switch (msg->GetMessageName()) {case CMD_START_COMMON_SCAN:      ---》 处理这个消息pScanStateMachine->CommonScanRequestProcess(msg);return true;case CMD_START_PNO_SCAN:pScanStateMachine->PnoScanRequestProcess(msg);return true;default:return false;}
}
// 发起 CommonScanRequestProcess 流程
void ScanStateMachine::CommonScanRequestProcess(InternalMessage *interMessage)
{WIFI_LOGI("ScanStateMachine::CommonScanRequestProcess.\n");int requestIndex = 0;InterScanConfig scanConfig;if (!GetCommonScanRequestInfo(interMessage, requestIndex, scanConfig)) {ReportCommonScanFailed(requestIndex);return;}if (!VerifyScanStyle(scanConfig.scanStyle)) {WIFI_LOGE("invalid scan type");return;}{std::unique_lock<std::shared_mutex> guard(lock);waitingScans.insert(std::pair<int, InterScanConfig>(requestIndex, scanConfig));}StartNewCommonScan();
}void ScanStateMachine::StartNewCommonScan()
{WIFI_LOGI("Enter ScanStateMachine::StartNewCommonScan.\n");{std::shared_lock<std::shared_mutex> guard(lock);if (waitingScans.size() == 0) {ContinuePnoScanProcess();return;}ClearRunningScanSettings();bool hasFullScan = false;/* Traverse the request list and combine parameters */std::map<int, InterScanConfig>::iterator configIter = waitingScans.begin();for (; configIter != waitingScans.end(); ++configIter) {runningScanSettings.scanStyle = MergeScanStyle(runningScanSettings.scanStyle, configIter->second.scanStyle);std::vector<std::string>::iterator hiddenIter = configIter->second.hiddenNetworkSsid.begin();/* Remove duplicate hidden list */for (; hiddenIter != configIter->second.hiddenNetworkSsid.end(); ++hiddenIter) {if (std::find(runningScanSettings.hiddenNetworkSsid.begin(),runningScanSettings.hiddenNetworkSsid.end(),*hiddenIter) != runningScanSettings.hiddenNetworkSsid.end()) {continue;}runningScanSettings.hiddenNetworkSsid.push_back(*hiddenIter);}if (!hasFullScan) {/* When scanFreqs is empty, it means that scan all frequenties */if (configIter->second.scanFreqs.empty()) {runningScanSettings.scanFreqs.clear();runningFullScanFlag = true;hasFullScan = true;} else {std::vector<int>::iterator freqIter = configIter->second.scanFreqs.begin();/* Repetitions are eliminated */for (; freqIter != configIter->second.scanFreqs.end(); ++freqIter) {if (std::find(runningScanSettings.scanFreqs.begin(),runningScanSettings.scanFreqs.end(),*freqIter) != runningScanSettings.scanFreqs.end()) {continue;}runningScanSettings.scanFreqs.push_back(*freqIter);}}}}}if (!StartSingleCommonScan(runningScanSettings)) {       ---》 继续看这个ReportCommonScanFailedAndClear(false);ContinuePnoScanProcess();return;}std::unique_lock<std::shared_mutex> guard(lock);runningScans.swap(waitingScans);waitingScans.clear();SwitchState(commonScanningState);WIFI_LOGI("StartNewCommonScan success.\n");
}bool ScanStateMachine::StartSingleCommonScan(WifiScanParam &scanParam)
{WIFI_LOGI("Enter ScanStateMachine::StartSingleCommonScan.\n");for (auto freqIter = scanParam.scanFreqs.begin(); freqIter != scanParam.scanFreqs.end(); ++freqIter) {WIFI_LOGI("freq is %{public}d.\n", *freqIter);}for (auto hiddenIter = scanParam.hiddenNetworkSsid.begin(); hiddenIter != scanParam.hiddenNetworkSsid.end();++hiddenIter) {WIFI_LOGI("hidden ssid is %{public}s.\n", SsidAnonymize(*hiddenIter).c_str());}WIFI_LOGI("Begin call Scan.\n");WifiErrorNo ret = WifiStaHalInterface::GetInstance().Scan(scanParam);      ---> 是不是很熟悉，要通过idl_clientif ((ret != WIFI_IDL_OPT_OK) && (ret != WIFI_IDL_OPT_SCAN_BUSY)) {WIFI_LOGE("WifiStaHalInterface::GetInstance().scan failed.");return false;}WIFI_LOGI("End call Scan.\n");/** Start the timer. If no result is returned for a long time, the scanning* fails*/StartTimer(static_cast<int>(WAIT_SCAN_RESULT_TIMER), MAX_WAIT_SCAN_RESULT_TIME);return true;
}

继续看下代码，WifiStaHalInterface里面的 Scan 方法：
foundation/communication/wifi/wifi/services/wifi_standard/wifi_framework/wifi_manage/idl_client/wifi_sta_hal_interface.cpp

WifiErrorNo WifiStaHalInterface::Scan(const WifiScanParam &scanParam)
{CHECK_NULL_AND_RETURN(mIdlClient, WIFI_IDL_OPT_FAILED);return mIdlClient->Scan(scanParam);
}// foundation/communication/wifi/wifi/services/wifi_standard/wifi_framework/wifi_manage/idl_client/wifi_idl_client.cpp
WifiErrorNo WifiIdlClient::Scan(const WifiScanParam &scanParam)
{CHECK_CLIENT_NOT_NULL;ScanSettings settings;if (memset_s(&settings, sizeof(settings), 0, sizeof(settings)) != EOK) {return WIFI_IDL_OPT_FAILED;}bool bfail = false;do {if (scanParam.hiddenNetworkSsid.size() > 0) {settings.hiddenSsidSize = scanParam.hiddenNetworkSsid.size();settings.hiddenSsid = ConVectorToCArrayString(scanParam.hiddenNetworkSsid);if (settings.hiddenSsid == nullptr) {bfail = true;break;}}if (scanParam.scanFreqs.size() > 0) {settings.freqSize = scanParam.scanFreqs.size();settings.freqs = (int *)calloc(settings.freqSize, sizeof(int));if (settings.freqs == nullptr) {bfail = true;break;}for (int i = 0; i < settings.freqSize; ++i) {settings.freqs[i] = scanParam.scanFreqs[i];}}if (scanParam.scanStyle > 0) {settings.scanStyle = scanParam.scanStyle;}} while (0);WifiErrorNo err = WIFI_IDL_OPT_FAILED;if (!bfail) {err = StartScan(&settings);      ---> 向 Hal 发起扫描}if (settings.freqs != nullptr) {free(settings.freqs);settings.freqs = nullptr;}if (settings.hiddenSsid != nullptr) {for (int i = 0; i < settings.hiddenSsidSize; ++i) {free(settings.hiddenSsid[i]);settings.hiddenSsid[i] = nullptr;}free(settings.hiddenSsid);settings.hiddenSsid = nullptr;}return err;
}
// 中间省略了 RPC的调用，代码可以看wifi_hal_crpc_server类，处理客户端请求，然后根据请求找到对应的函数，在调用HAL的方法
// 直接看调用的HAL方法：foundation/communication/wifi/wifi/services/wifi_standard/wifi_hal/wifi_hal_sta_interface.c
WifiErrorNo StartScan(const ScanSettings *settings)
{LOGD("Ready to start scan with param.");
#ifdef HDI_INTERFACE_SUPPORTint ret = HdiStartScan(settings);
#elseWifiWpaStaInterface *pStaIfc = GetWifiStaInterface(0);if (pStaIfc == NULL) {return WIFI_HAL_SUPPLICANT_NOT_INIT;}int ret = pStaIfc->wpaCliCmdScan(pStaIfc, settings);    ---> 往supplicant 发送命令if (ret < 0) {LOGE("StartScan failed! ret=%{public}d", ret);return WIFI_HAL_FAILED;}
#endifif (ret == WIFI_HAL_SCAN_BUSY) {LOGD("StartScan return scan busy");return WIFI_HAL_SCAN_BUSY;}LOGD("StartScan successfully!");return WIFI_HAL_SUCCESS;
}// int (*wpaCliCmdScan)(WifiWpaStaInterface *p, const ScanSettings *settings);
// wifi/services/wifi_standard/wifi_hal/wifi_hal_module/wpa_supplicant_hal/wpa_sta_hal/wifi_supplicant_hal.c
static int WpaCliCmdScan(WifiWpaStaInterface *this, const ScanSettings *settings)
{if (this == NULL) {LOGE("WpaCliCmdScan, this is NULL!");return -1;}/* Invalidate expired scan results */WpaCliCmdBssFlush(this);unsigned len = CMD_BUFFER_SIZE;unsigned expectedLen = 0;if (settings != NULL) {expectedLen = AssignCmdLen(this, settings);}if (expectedLen >= len) {len = expectedLen + 1;}char *pcmd = (char *)calloc(len, sizeof(char));if (pcmd == NULL) {LOGE("WpaCliCmdScan, pcmd is NULL!");return -1;}int pos = 0;int res = 0;if (settings != NULL) {if (settings->scanStyle == SCAN_TYPE_PNO && settings->isStartPnoScan) {res = snprintf_s(pcmd, len, len - 1, "IFNAME=%s set pno 1", this->ifname);} else if (settings->scanStyle == SCAN_TYPE_PNO && !settings->isStartPnoScan) {res = snprintf_s(pcmd, len, len - 1, "IFNAME=%s set pno 0", this->ifname);} else {res = snprintf_s(pcmd, len, len - 1, "IFNAME=%s SCAN", this->ifname);}}if (res < 0) {LOGE("WpaCliCmdScan, snprintf_s error!");free(pcmd);return -1;}pos += res;if (settings != NULL && ConcatScanSetting(settings, pcmd + pos, len - pos) < 0) {LOGE("snprintf scan settings error");free(pcmd);return -1;}char buf[REPLY_BUF_SMALL_LENGTH] = {0};if (WpaCliCmd(pcmd, buf, sizeof(buf)) != 0) {      ---》 命令下发free(pcmd);return -1;}free(pcmd);if (strncmp(buf, "FAIL-BUSY", strlen("FAIL-BUSY")) == 0) {LOGE("WpaCliCmdScan, WpaCliCmd return FAIL-BUSY!");return FAIL_BUSY;}return 0;
}// foundation/communication/wifi/wifi/services/wifi_standard/wifi_hal/wifi_hal_module/wpa_supplicant_hal/wifi_wpa_common.c
int WpaCliCmd(const char *cmd, char *buf, size_t bufLen)
{if (cmd == NULL || buf == NULL || bufLen <= 0) {LOGE("WpaCliCmd, invalid parameters!");return -1;}WpaCtrl *ctrl = GetWpaCtrl();if (ctrl == NULL || ctrl->pSend == NULL) {LOGE("WpaCliCmd, ctrl/ctrl->pSend is NULL!");return -1;}size_t len = bufLen - 1;LOGI("wpa_ctrl_request -> cmd: %{private}s", cmd);int ret = wpa_ctrl_request(ctrl->pSend, cmd, strlen(cmd), buf, &len, NULL);if (ret == WPA_CMD_RETURN_TIMEOUT) {LOGE("[%{private}s] command timed out.", cmd);return WPA_CMD_RETURN_TIMEOUT;} else if (ret < 0) {LOGE("[%{private}s] command failed.", cmd);return -1;}buf[len] = '\0';LOGI("wpa_ctrl_request -> buf: %{private}s", buf);if (strncmp(buf, "FAIL\n", strlen("FAIL\n")) == 0 ||strncmp(buf, "UNKNOWN COMMAND\n", strlen("UNKNOWN COMMAND\n")) == 0) {LOGE("%{private}s request success, but response %{public}s", cmd, buf);return -1;}return 0;
}

到此我们就看到命令发送到wpa，然后wpa 收到命令后去做扫描动作，那扫描到结果如何通知上层呢？下一篇我们继续记录。