PublicVolume.cpp - SHIFTPHONES/android_system_vold - Gitiles

 /*
  * Copyright (C) 2015 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.
  */

 #define LOG_TAG "Vold"

 #include "Fat.h"
 #include "PublicVolume.h"
 #include "Utils.h"

 #include <cutils/fs.h>
 #include <cutils/log.h>
 #include <utils/file.h>
 #include <utils/stringprintf.h>
 #include <private/android_filesystem_config.h>

 #include <fcntl.h>
 #include <stdlib.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>

 namespace android {
 namespace vold {

 static const char* kBlkidPath = "/system/bin/blkid";
 static const char* kFusePath = "/system/bin/sdcard";

 static const char* kUserMountPath = "/mnt/user";

 PublicVolume::PublicVolume(dev_t device) :
         VolumeBase(VolumeType::kPublic), mDevice(device), mFusePid(0), mPrimary(false) {
     mId = StringPrintf("public:%ud:%ud", major(device), minor(device));
     mDevPath = StringPrintf("/dev/block/vold/%ud:%ud", major(device), minor(device));
     mRawPath = StringPrintf("/mnt/media_rw/public_raw_%ud:%ud", major(device), minor(device));
     mFusePath = StringPrintf("/mnt/media_rw/public_fuse_%ud:%ud", major(device), minor(device));

     CreateDeviceNode(mDevPath, device);
 }

 PublicVolume::~PublicVolume() {
     DestroyDeviceNode(mDevPath);
 }

 status_t PublicVolume::readMetadata() {
     mFsUuid = "";
     mFsLabel = "";

     std::string path(StringPrintf("%s -c /dev/null %s", kBlkidPath, mDevPath.c_str()));
     FILE* fp = popen(path.c_str(), "r");
     if (!fp) {
         ALOGE("Failed to run %s: %s", path.c_str(), strerror(errno));
         return -errno;
     }

     char line[1024];
     char value[128];
     if (fgets(line, sizeof(line), fp) != nullptr) {
         ALOGD("blkid identified as %s", line);

         char* start = strstr(line, "UUID=");
         if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
             mFsUuid = value;
         }

         start = strstr(line, "LABEL=");
         if (start != nullptr && sscanf(start + 6, "\"%127[^\"]\"", value) == 1) {
             mFsLabel = value;
         }
     } else {
         ALOGW("blkid failed to identify %s", mDevPath.c_str());
         return -ENODATA;
     }

     pclose(fp);

     // TODO: broadcast ident to framework
     return OK;
 }

 status_t PublicVolume::initAsecStage() {
     std::string legacyPath(mRawPath + "/android_secure");
     std::string securePath(mRawPath + "/.android_secure");

     // Recover legacy secure path
     if (!access(legacyPath.c_str(), R_OK | X_OK)
             && access(securePath.c_str(), R_OK | X_OK)) {
         if (rename(legacyPath.c_str(), securePath.c_str())) {
             SLOGE("Failed to rename legacy ASEC dir: %s", strerror(errno));
         }
     }

     if (fs_prepare_dir(securePath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW) != 0) {
         SLOGW("fs_prepare_dir failed: %s", strerror(errno));
         return -errno;
     }

     return OK;
 }

 status_t PublicVolume::doMount() {
     if (Fat::check(mDevPath.c_str())) {
         SLOGE("Failed filesystem check; not mounting");
         return -EIO;
     }

     if (fs_prepare_dir(mRawPath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW)) {
         SLOGE("Failed to create mount point %s: %s", mRawPath.c_str(), strerror(errno));
         return -errno;
     }
     if (fs_prepare_dir(mFusePath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW)) {
         SLOGE("Failed to create mount point %s: %s", mFusePath.c_str(), strerror(errno));
         return -errno;
     }

     if (Fat::doMount(mDevPath.c_str(), mRawPath.c_str(), false, false, false,
             AID_MEDIA_RW, AID_MEDIA_RW, 0007, true)) {
         SLOGE("Failed to mount %s: %s", mDevPath.c_str(), strerror(errno));
         return -EIO;
     }

     if (!(mFusePid = fork())) {
         if (mPrimary) {
             if (execl(kFusePath,
                     "-u", "1023", // AID_MEDIA_RW
                     "-g", "1023", // AID_MEDIA_RW
                     "-d",
                     mRawPath.c_str(),
                     mFusePath.c_str())) {
                 SLOGE("Failed to exec: %s", strerror(errno));
             }
         } else {
             if (execl(kFusePath,
                     "-u", "1023", // AID_MEDIA_RW
                     "-g", "1023", // AID_MEDIA_RW
                     "-w", "1023", // AID_MEDIA_RW
                     "-d",
                     mRawPath.c_str(),
                     mFusePath.c_str())) {
                 SLOGE("Failed to exec: %s", strerror(errno));
             }
         }

         _exit(1);
     }

     if (mFusePid == -1) {
         SLOGE("Failed to fork: %s", strerror(errno));
         return -errno;
     }

     return OK;
 }

 status_t PublicVolume::doUnmount() {
     if (mFusePid > 0) {
         kill(mFusePid, SIGTERM);
         TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, 0));
         mFusePid = 0;
     }

     ForceUnmount(mFusePath);
     ForceUnmount(mRawPath);

     TEMP_FAILURE_RETRY(unlink(mRawPath.c_str()));
     TEMP_FAILURE_RETRY(unlink(mFusePath.c_str()));

     return OK;
 }

 status_t PublicVolume::doFormat() {
     if (Fat::format(mDevPath.c_str(), 0, true)) {
         SLOGE("Failed to format: %s", strerror(errno));
         return -errno;
     }
     return OK;
 }

 status_t PublicVolume::bindUser(userid_t user) {
     return bindUserInternal(user, true);
 }

 status_t PublicVolume::unbindUser(userid_t user) {
     return bindUserInternal(user, false);
 }

 status_t PublicVolume::bindUserInternal(userid_t user, bool bind) {
     if (mPrimary) {
         if (user == 0) {
             std::string path(StringPrintf("%s/%ud/primary", kUserMountPath, user));
             if (bind) {
                 mountBind(mFusePath, path);
             } else {
                 unmountBind(path);
             }
         } else {
             // Public volumes are only visible to owner when primary
             // storage, so we don't mount for secondary users.
         }
     } else {
         std::string path(StringPrintf("%s/%ud/public_%ud:%ud", kUserMountPath, user,
                         major(mDevice), minor(mDevice)));
         if (bind) {
             mountBind(mFusePath, path);
         } else {
             unmountBind(path);
         }

         if (user != 0) {
             // To prevent information leakage between users, only owner
             // has access to the Android directory
             path += "/Android";
             if (bind) {
                 if (::mount("tmpfs", path.c_str(), "tmpfs", MS_NOSUID, "mode=0000")) {
                     SLOGE("Failed to protect secondary path %s: %s",
                             path.c_str(), strerror(errno));
                     return -errno;
                 }
             } else {
                 ForceUnmount(path);
             }
         }
     }

     return OK;
 }

 void PublicVolume::setPrimary(bool primary) {
     if (getState() != VolumeState::kUnmounted) {
         SLOGE("Primary state change requires %s to be unmounted", getId().c_str());
         return;
     }

     mPrimary = primary;
 }

 }  // namespace vold
 }  // namespace android
	/*
	* Copyright (C) 2015 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.
	*/

	#define LOG_TAG "Vold"

	#include "Fat.h"
	#include "PublicVolume.h"
	#include "Utils.h"

	#include <cutils/fs.h>
	#include <cutils/log.h>
	#include <utils/file.h>
	#include <utils/stringprintf.h>
	#include <private/android_filesystem_config.h>

	#include <fcntl.h>
	#include <stdlib.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	namespace android {
	namespace vold {

	static const char* kBlkidPath = "/system/bin/blkid";
	static const char* kFusePath = "/system/bin/sdcard";

	static const char* kUserMountPath = "/mnt/user";

	PublicVolume::PublicVolume(dev_t device) :
	VolumeBase(VolumeType::kPublic), mDevice(device), mFusePid(0), mPrimary(false) {
	mId = StringPrintf("public:%ud:%ud", major(device), minor(device));
	mDevPath = StringPrintf("/dev/block/vold/%ud:%ud", major(device), minor(device));
	mRawPath = StringPrintf("/mnt/media_rw/public_raw_%ud:%ud", major(device), minor(device));
	mFusePath = StringPrintf("/mnt/media_rw/public_fuse_%ud:%ud", major(device), minor(device));

	CreateDeviceNode(mDevPath, device);
	}

	PublicVolume::~PublicVolume() {
	DestroyDeviceNode(mDevPath);
	}

	status_t PublicVolume::readMetadata() {
	mFsUuid = "";
	mFsLabel = "";

	std::string path(StringPrintf("%s -c /dev/null %s", kBlkidPath, mDevPath.c_str()));
	FILE* fp = popen(path.c_str(), "r");
	if (!fp) {
	ALOGE("Failed to run %s: %s", path.c_str(), strerror(errno));
	return -errno;
	}

	char line[1024];
	char value[128];
	if (fgets(line, sizeof(line), fp) != nullptr) {
	ALOGD("blkid identified as %s", line);

	char* start = strstr(line, "UUID=");
	if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
	mFsUuid = value;
	}

	start = strstr(line, "LABEL=");
	if (start != nullptr && sscanf(start + 6, "\"%127[^\"]\"", value) == 1) {
	mFsLabel = value;
	}
	} else {
	ALOGW("blkid failed to identify %s", mDevPath.c_str());
	return -ENODATA;
	}

	pclose(fp);

	// TODO: broadcast ident to framework
	return OK;
	}

	status_t PublicVolume::initAsecStage() {
	std::string legacyPath(mRawPath + "/android_secure");
	std::string securePath(mRawPath + "/.android_secure");

	// Recover legacy secure path
	if (!access(legacyPath.c_str(), R_OK \| X_OK)
	&& access(securePath.c_str(), R_OK \| X_OK)) {
	if (rename(legacyPath.c_str(), securePath.c_str())) {
	SLOGE("Failed to rename legacy ASEC dir: %s", strerror(errno));
	}
	}

	if (fs_prepare_dir(securePath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW) != 0) {
	SLOGW("fs_prepare_dir failed: %s", strerror(errno));
	return -errno;
	}

	return OK;
	}

	status_t PublicVolume::doMount() {
	if (Fat::check(mDevPath.c_str())) {
	SLOGE("Failed filesystem check; not mounting");
	return -EIO;
	}

	if (fs_prepare_dir(mRawPath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW)) {
	SLOGE("Failed to create mount point %s: %s", mRawPath.c_str(), strerror(errno));
	return -errno;
	}
	if (fs_prepare_dir(mFusePath.c_str(), 0770, AID_MEDIA_RW, AID_MEDIA_RW)) {
	SLOGE("Failed to create mount point %s: %s", mFusePath.c_str(), strerror(errno));
	return -errno;
	}

	if (Fat::doMount(mDevPath.c_str(), mRawPath.c_str(), false, false, false,
	AID_MEDIA_RW, AID_MEDIA_RW, 0007, true)) {
	SLOGE("Failed to mount %s: %s", mDevPath.c_str(), strerror(errno));
	return -EIO;
	}

	if (!(mFusePid = fork())) {
	if (mPrimary) {
	if (execl(kFusePath,
	"-u", "1023", // AID_MEDIA_RW
	"-g", "1023", // AID_MEDIA_RW
	"-d",
	mRawPath.c_str(),
	mFusePath.c_str())) {
	SLOGE("Failed to exec: %s", strerror(errno));
	}
	} else {
	if (execl(kFusePath,
	"-u", "1023", // AID_MEDIA_RW
	"-g", "1023", // AID_MEDIA_RW
	"-w", "1023", // AID_MEDIA_RW
	"-d",
	mRawPath.c_str(),
	mFusePath.c_str())) {
	SLOGE("Failed to exec: %s", strerror(errno));
	}
	}

	_exit(1);
	}

	if (mFusePid == -1) {
	SLOGE("Failed to fork: %s", strerror(errno));
	return -errno;
	}

	return OK;
	}

	status_t PublicVolume::doUnmount() {
	if (mFusePid > 0) {
	kill(mFusePid, SIGTERM);
	TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, 0));
	mFusePid = 0;
	}

	ForceUnmount(mFusePath);
	ForceUnmount(mRawPath);

	TEMP_FAILURE_RETRY(unlink(mRawPath.c_str()));
	TEMP_FAILURE_RETRY(unlink(mFusePath.c_str()));

	return OK;
	}

	status_t PublicVolume::doFormat() {
	if (Fat::format(mDevPath.c_str(), 0, true)) {
	SLOGE("Failed to format: %s", strerror(errno));
	return -errno;
	}
	return OK;
	}

	status_t PublicVolume::bindUser(userid_t user) {
	return bindUserInternal(user, true);
	}

	status_t PublicVolume::unbindUser(userid_t user) {
	return bindUserInternal(user, false);
	}

	status_t PublicVolume::bindUserInternal(userid_t user, bool bind) {
	if (mPrimary) {
	if (user == 0) {
	std::string path(StringPrintf("%s/%ud/primary", kUserMountPath, user));
	if (bind) {
	mountBind(mFusePath, path);
	} else {
	unmountBind(path);
	}
	} else {
	// Public volumes are only visible to owner when primary
	// storage, so we don't mount for secondary users.
	}
	} else {
	std::string path(StringPrintf("%s/%ud/public_%ud:%ud", kUserMountPath, user,
	major(mDevice), minor(mDevice)));
	if (bind) {
	mountBind(mFusePath, path);
	} else {
	unmountBind(path);
	}

	if (user != 0) {
	// To prevent information leakage between users, only owner
	// has access to the Android directory
	path += "/Android";
	if (bind) {
	if (::mount("tmpfs", path.c_str(), "tmpfs", MS_NOSUID, "mode=0000")) {
	SLOGE("Failed to protect secondary path %s: %s",
	path.c_str(), strerror(errno));
	return -errno;
	}
	} else {
	ForceUnmount(path);
	}
	}
	}

	return OK;
	}

	void PublicVolume::setPrimary(bool primary) {
	if (getState() != VolumeState::kUnmounted) {
	SLOGE("Primary state change requires %s to be unmounted", getId().c_str());
	return;
	}

	mPrimary = primary;
	}

	} // namespace vold
	} // namespace android