libwifi_system/supplicant_manager.cpp - platform/frameworks/opt/net/wifi - Git at Google

 /*
  * Copyright (C) 2016 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.
  */

 #include "wifi_system/supplicant_manager.h"

 #include <android-base/logging.h>
 #include <cutils/properties.h>
 #include <fcntl.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>

 // This ugliness is necessary to access internal implementation details
 // of the property subsystem.
 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/_system_properties.h>

 namespace android {
 namespace wifi_system {
 namespace {

 const char kSupplicantInitProperty[] = "init.svc.wpa_supplicant";
 const char kSupplicantConfigTemplatePath[] =
     "/etc/wifi/wpa_supplicant.conf";
 const char kSupplicantConfigFile[] = "/data/misc/wifi/wpa_supplicant.conf";
 const char kP2pConfigFile[] = "/data/misc/wifi/p2p_supplicant.conf";
 const char kSupplicantServiceName[] = "wpa_supplicant";
 constexpr mode_t kConfigFileMode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;

 const char kWiFiEntropyFile[] = "/data/misc/wifi/entropy.bin";

 const unsigned char kDummyKey[21] = {0x02, 0x11, 0xbe, 0x33, 0x43, 0x35, 0x68,
                                      0x47, 0x84, 0x99, 0xa9, 0x2b, 0x1c, 0xd3,
                                      0xee, 0xff, 0xf1, 0xe2, 0xf3, 0xf4, 0xf5};

 int ensure_config_file_exists(const char* config_file) {
   char buf[2048];
   int srcfd, destfd;
   int nread;
   int ret;
   std::string templatePath;

   ret = access(config_file, R_OK | W_OK);
   if ((ret == 0) || (errno == EACCES)) {
     if ((ret != 0) && (chmod(config_file, kConfigFileMode) != 0)) {
       LOG(ERROR) << "Cannot set RW to \"" << config_file << "\": "
                  << strerror(errno);
       return false;
     }
     return true;
   } else if (errno != ENOENT) {
     LOG(ERROR) << "Cannot access \"" << config_file << "\": "
                << strerror(errno);
     return false;
   }

   std::string configPathSystem =
       std::string("/system") + std::string(kSupplicantConfigTemplatePath);
   std::string configPathVendor =
       std::string("/vendor") + std::string(kSupplicantConfigTemplatePath);
   srcfd = TEMP_FAILURE_RETRY(open(configPathSystem.c_str(), O_RDONLY));
   templatePath = configPathSystem;
   if (srcfd < 0) {
     int errnoSystem = errno;
     srcfd = TEMP_FAILURE_RETRY(open(configPathVendor.c_str(), O_RDONLY));
     templatePath = configPathVendor;
     if (srcfd < 0) {
       int errnoVendor = errno;
       LOG(ERROR) << "Cannot open \"" << configPathSystem << "\": "
                  << strerror(errnoSystem);
       LOG(ERROR) << "Cannot open \"" << configPathVendor << "\": "
                  << strerror(errnoVendor);
       return false;
     }
   }

   destfd = TEMP_FAILURE_RETRY(open(config_file,
                                    O_CREAT | O_RDWR,
                                    kConfigFileMode));
   if (destfd < 0) {
     close(srcfd);
     LOG(ERROR) << "Cannot create \"" << config_file << "\": "
                << strerror(errno);
     return false;
   }

   while ((nread = TEMP_FAILURE_RETRY(read(srcfd, buf, sizeof(buf)))) != 0) {
     if (nread < 0) {
       LOG(ERROR) << "Error reading \"" << templatePath
                  << "\": " << strerror(errno);
       close(srcfd);
       close(destfd);
       unlink(config_file);
       return false;
     }
     TEMP_FAILURE_RETRY(write(destfd, buf, nread));
   }

   close(destfd);
   close(srcfd);

   /* chmod is needed because open() didn't set permisions properly */
   if (chmod(config_file, kConfigFileMode) < 0) {
     LOG(ERROR) << "Error changing permissions of " << config_file
                << " to 0660: " << strerror(errno);
     unlink(config_file);
     return false;
   }

   return true;
 }

 }  // namespace

 bool SupplicantManager::StartSupplicant() {
   char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
   int count = 200; /* wait at most 20 seconds for completion */
   const prop_info* pi;
   unsigned serial = 0;

   /* Check whether already running */
   if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
       strcmp(supp_status, "running") == 0) {
     return true;
   }

   /* Before starting the daemon, make sure its config file exists */
   if (ensure_config_file_exists(kSupplicantConfigFile) < 0) {
     LOG(ERROR) << "Wi-Fi will not be enabled";
     return false;
   }

   /*
    * Some devices have another configuration file for the p2p interface.
    * However, not all devices have this, and we'll let it slide if it
    * is missing.  For devices that do expect this file to exist,
    * supplicant will refuse to start and emit a good error message.
    * No need to check for it here.
    */
   (void)ensure_config_file_exists(kP2pConfigFile);

   if (!EnsureEntropyFileExists()) {
     LOG(ERROR) << "Wi-Fi entropy file was not created";
   }

   /*
    * Get a reference to the status property, so we can distinguish
    * the case where it goes stopped => running => stopped (i.e.,
    * it start up, but fails right away) from the case in which
    * it starts in the stopped state and never manages to start
    * running at all.
    */
   pi = __system_property_find(kSupplicantInitProperty);
   if (pi != NULL) {
     serial = __system_property_serial(pi);
   }

   property_set("ctl.start", kSupplicantServiceName);
   sched_yield();

   while (count-- > 0) {
     if (pi == NULL) {
       pi = __system_property_find(kSupplicantInitProperty);
     }
     if (pi != NULL) {
       /*
        * property serial updated means that init process is scheduled
        * after we sched_yield, further property status checking is based on this
        */
       if (__system_property_serial(pi) != serial) {
         __system_property_read(pi, NULL, supp_status);
         if (strcmp(supp_status, "running") == 0) {
           return true;
         } else if (strcmp(supp_status, "stopped") == 0) {
           return false;
         }
       }
     }
     usleep(100000);
   }
   return false;
 }

 bool SupplicantManager::StopSupplicant() {
   char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
   int count = 50; /* wait at most 5 seconds for completion */

   /* Check whether supplicant already stopped */
   if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
       strcmp(supp_status, "stopped") == 0) {
     return true;
   }

   property_set("ctl.stop", kSupplicantServiceName);
   sched_yield();

   while (count-- > 0) {
     if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
       if (strcmp(supp_status, "stopped") == 0) return true;
     }
     usleep(100000);
   }
   LOG(ERROR) << "Failed to stop supplicant";
   return false;
 }

 bool SupplicantManager::IsSupplicantRunning() {
   char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
   if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
     return strcmp(supp_status, "running") == 0;
   }
   return false;  // Failed to read service status from init.
 }

 bool SupplicantManager::EnsureEntropyFileExists() {
   int ret;
   int destfd;

   ret = access(kWiFiEntropyFile, R_OK | W_OK);
   if ((ret == 0) || (errno == EACCES)) {
     if ((ret != 0) &&
         (chmod(kWiFiEntropyFile, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) != 0)) {
       PLOG(ERROR) << "Cannot set RW to " << kWiFiEntropyFile;
       return false;
     }
     return true;
   }
   destfd = TEMP_FAILURE_RETRY(open(kWiFiEntropyFile, O_CREAT | O_RDWR, 0660));
   if (destfd < 0) {
     PLOG(ERROR) << "Cannot create " << kWiFiEntropyFile;
     return false;
   }

   if (TEMP_FAILURE_RETRY(write(destfd, kDummyKey, sizeof(kDummyKey))) !=
       sizeof(kDummyKey)) {
     PLOG(ERROR) << "Error writing " << kWiFiEntropyFile;
     close(destfd);
     return false;
   }
   close(destfd);

   /* chmod is needed because open() didn't set permisions properly */
   if (chmod(kWiFiEntropyFile, 0660) < 0) {
     PLOG(ERROR) << "Error changing permissions of " << kWiFiEntropyFile
                 << " to 0600 ";
     unlink(kWiFiEntropyFile);
     return false;
   }

   return true;
 }

 }  // namespace wifi_system
 }  // namespace android
	/*
	* Copyright (C) 2016 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.
	*/

	#include "wifi_system/supplicant_manager.h"

	#include <android-base/logging.h>
	#include <cutils/properties.h>
	#include <fcntl.h>
	#include <string.h>
	#include <sys/stat.h>
	#include <unistd.h>

	// This ugliness is necessary to access internal implementation details
	// of the property subsystem.
	#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
	#include <sys/_system_properties.h>

	namespace android {
	namespace wifi_system {
	namespace {

	const char kSupplicantInitProperty[] = "init.svc.wpa_supplicant";
	const char kSupplicantConfigTemplatePath[] =
	"/etc/wifi/wpa_supplicant.conf";
	const char kSupplicantConfigFile[] = "/data/misc/wifi/wpa_supplicant.conf";
	const char kP2pConfigFile[] = "/data/misc/wifi/p2p_supplicant.conf";
	const char kSupplicantServiceName[] = "wpa_supplicant";
	constexpr mode_t kConfigFileMode = S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP;

	const char kWiFiEntropyFile[] = "/data/misc/wifi/entropy.bin";

	const unsigned char kDummyKey[21] = {0x02, 0x11, 0xbe, 0x33, 0x43, 0x35, 0x68,
	0x47, 0x84, 0x99, 0xa9, 0x2b, 0x1c, 0xd3,
	0xee, 0xff, 0xf1, 0xe2, 0xf3, 0xf4, 0xf5};

	int ensure_config_file_exists(const char* config_file) {
	char buf[2048];
	int srcfd, destfd;
	int nread;
	int ret;
	std::string templatePath;

	ret = access(config_file, R_OK \| W_OK);
	if ((ret == 0) \|\| (errno == EACCES)) {
	if ((ret != 0) && (chmod(config_file, kConfigFileMode) != 0)) {
	LOG(ERROR) << "Cannot set RW to \"" << config_file << "\": "
	<< strerror(errno);
	return false;
	}
	return true;
	} else if (errno != ENOENT) {
	LOG(ERROR) << "Cannot access \"" << config_file << "\": "
	<< strerror(errno);
	return false;
	}

	std::string configPathSystem =
	std::string("/system") + std::string(kSupplicantConfigTemplatePath);
	std::string configPathVendor =
	std::string("/vendor") + std::string(kSupplicantConfigTemplatePath);
	srcfd = TEMP_FAILURE_RETRY(open(configPathSystem.c_str(), O_RDONLY));
	templatePath = configPathSystem;
	if (srcfd < 0) {
	int errnoSystem = errno;
	srcfd = TEMP_FAILURE_RETRY(open(configPathVendor.c_str(), O_RDONLY));
	templatePath = configPathVendor;
	if (srcfd < 0) {
	int errnoVendor = errno;
	LOG(ERROR) << "Cannot open \"" << configPathSystem << "\": "
	<< strerror(errnoSystem);
	LOG(ERROR) << "Cannot open \"" << configPathVendor << "\": "
	<< strerror(errnoVendor);
	return false;
	}
	}

	destfd = TEMP_FAILURE_RETRY(open(config_file,
	O_CREAT \| O_RDWR,
	kConfigFileMode));
	if (destfd < 0) {
	close(srcfd);
	LOG(ERROR) << "Cannot create \"" << config_file << "\": "
	<< strerror(errno);
	return false;
	}

	while ((nread = TEMP_FAILURE_RETRY(read(srcfd, buf, sizeof(buf)))) != 0) {
	if (nread < 0) {
	LOG(ERROR) << "Error reading \"" << templatePath
	<< "\": " << strerror(errno);
	close(srcfd);
	close(destfd);
	unlink(config_file);
	return false;
	}
	TEMP_FAILURE_RETRY(write(destfd, buf, nread));
	}

	close(destfd);
	close(srcfd);

	/* chmod is needed because open() didn't set permisions properly */
	if (chmod(config_file, kConfigFileMode) < 0) {
	LOG(ERROR) << "Error changing permissions of " << config_file
	<< " to 0660: " << strerror(errno);
	unlink(config_file);
	return false;
	}

	return true;
	}

	} // namespace

	bool SupplicantManager::StartSupplicant() {
	char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
	int count = 200; /* wait at most 20 seconds for completion */
	const prop_info* pi;
	unsigned serial = 0;

	/* Check whether already running */
	if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
	strcmp(supp_status, "running") == 0) {
	return true;
	}

	/* Before starting the daemon, make sure its config file exists */
	if (ensure_config_file_exists(kSupplicantConfigFile) < 0) {
	LOG(ERROR) << "Wi-Fi will not be enabled";
	return false;
	}

	/*
	* Some devices have another configuration file for the p2p interface.
	* However, not all devices have this, and we'll let it slide if it
	* is missing. For devices that do expect this file to exist,
	* supplicant will refuse to start and emit a good error message.
	* No need to check for it here.
	*/
	(void)ensure_config_file_exists(kP2pConfigFile);

	if (!EnsureEntropyFileExists()) {
	LOG(ERROR) << "Wi-Fi entropy file was not created";
	}

	/*
	* Get a reference to the status property, so we can distinguish
	* the case where it goes stopped => running => stopped (i.e.,
	* it start up, but fails right away) from the case in which
	* it starts in the stopped state and never manages to start
	* running at all.
	*/
	pi = __system_property_find(kSupplicantInitProperty);
	if (pi != NULL) {
	serial = __system_property_serial(pi);
	}

	property_set("ctl.start", kSupplicantServiceName);
	sched_yield();

	while (count-- > 0) {
	if (pi == NULL) {
	pi = __system_property_find(kSupplicantInitProperty);
	}
	if (pi != NULL) {
	/*
	* property serial updated means that init process is scheduled
	* after we sched_yield, further property status checking is based on this
	*/
	if (__system_property_serial(pi) != serial) {
	__system_property_read(pi, NULL, supp_status);
	if (strcmp(supp_status, "running") == 0) {
	return true;
	} else if (strcmp(supp_status, "stopped") == 0) {
	return false;
	}
	}
	}
	usleep(100000);
	}
	return false;
	}

	bool SupplicantManager::StopSupplicant() {
	char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
	int count = 50; /* wait at most 5 seconds for completion */

	/* Check whether supplicant already stopped */
	if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
	strcmp(supp_status, "stopped") == 0) {
	return true;
	}

	property_set("ctl.stop", kSupplicantServiceName);
	sched_yield();

	while (count-- > 0) {
	if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
	if (strcmp(supp_status, "stopped") == 0) return true;
	}
	usleep(100000);
	}
	LOG(ERROR) << "Failed to stop supplicant";
	return false;
	}

	bool SupplicantManager::IsSupplicantRunning() {
	char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
	if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
	return strcmp(supp_status, "running") == 0;
	}
	return false; // Failed to read service status from init.
	}

	bool SupplicantManager::EnsureEntropyFileExists() {
	int ret;
	int destfd;

	ret = access(kWiFiEntropyFile, R_OK \| W_OK);
	if ((ret == 0) \|\| (errno == EACCES)) {
	if ((ret != 0) &&
	(chmod(kWiFiEntropyFile, S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP) != 0)) {
	PLOG(ERROR) << "Cannot set RW to " << kWiFiEntropyFile;
	return false;
	}
	return true;
	}
	destfd = TEMP_FAILURE_RETRY(open(kWiFiEntropyFile, O_CREAT \| O_RDWR, 0660));
	if (destfd < 0) {
	PLOG(ERROR) << "Cannot create " << kWiFiEntropyFile;
	return false;
	}

	if (TEMP_FAILURE_RETRY(write(destfd, kDummyKey, sizeof(kDummyKey))) !=
	sizeof(kDummyKey)) {
	PLOG(ERROR) << "Error writing " << kWiFiEntropyFile;
	close(destfd);
	return false;
	}
	close(destfd);

	/* chmod is needed because open() didn't set permisions properly */
	if (chmod(kWiFiEntropyFile, 0660) < 0) {
	PLOG(ERROR) << "Error changing permissions of " << kWiFiEntropyFile
	<< " to 0600 ";
	unlink(kWiFiEntropyFile);
	return false;
	}

	return true;
	}

	} // namespace wifi_system
	} // namespace android