Files
android_bootable_recovery/mtp/mtp_MtpServer.cpp
Ethan Yonker 726a020632 MTP add/remove storage instead of disabling MTP
Implement a pipe between TWRP and MTP to allow TWRP to tell MTP
to remove storage partitions as they become unavailable (e.g.
during a wipe, unmount, etc) instead of disabling MTP completely.
This includes some fixes and improvements in destructors to
properly remove / delete various items. This also means that we
will not be toggling adb off and on quite as often.

I do not like that we had to add another thread, but we were
unable to use select() on the mtp_usb character device because
this device does not support polling. Select always returned
indicating that the mtp file descriptor was ready to be read and
the resulting read would block. The read block prevented us from
being able to include reading of the pipe between TWRP and MTP in
the main MTP thread.

We might want to add a return pipe letting TWRP know if the
removal of the storage device was successful, but I am not sure
how we want to implement this. It would invovle timeouts in both
TWRP and MTP to ensure that we returned a failure indicator in a
timely manner to TWRP and prevent deleting the storage device in
the case of a failure. Right now we make no attempt to ensure that
an MTP operation is underway like a large file transfer, but we
were not doing anything like this in the past. In some respects we
have limited control over what happens. If the user installs a
zip that unmounts a storage partition, we will not know about the
change in storage status anyway. Regular Android does not have
these troubles because partitions rarely get unmounted like in
recovery. At some point, we have to hold the user accountable for
performing actions that may remove a storage partition while they
are using MTP anyway.

Ideally we do not want to toggle the USB IDs and thus toggle adb
off and on during early boot, but I am not sure what the best way
to handle that at this time.

Change-Id: I9343e5396bf6023d3b994de1bf01ed91d129bc14
2014-12-19 16:27:34 -06:00

199 lines
5.2 KiB
C++
Executable File

/*
* Copyright (C) 2010 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.
*
* Copyright (C) 2014 TeamWin - bigbiff and Dees_Troy mtp database conversion to C++
*/
#include <utils/Log.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <vector>
#include <utils/threads.h>
#include <pthread.h>
#include "mtp_MtpServer.hpp"
#include "MtpServer.h"
#include "MtpStorage.h"
#include "MtpDebug.h"
#include "MtpMessage.hpp"
#include <string>
void twmtp_MtpServer::start()
{
if (setup() == 0) {
add_storage();
MTPD("Starting add / remove mtppipe monitor thread\n");
pthread_t thread;
ThreadPtr mtpptr = &twmtp_MtpServer::mtppipe_thread;
PThreadPtr p = *(PThreadPtr*)&mtpptr;
pthread_create(&thread, NULL, p, this);
server->run();
}
}
void twmtp_MtpServer::set_storages(storages* mtpstorages) {
stores = mtpstorages;
}
int twmtp_MtpServer::setup()
{
usePtp = false;
MyMtpDatabase* mtpdb = new MyMtpDatabase();
#ifdef USB_MTP_DEVICE
#define STRINGIFY(x) #x
#define EXPAND(x) STRINGIFY(x)
MTPI("Using '%s' for MTP device.\n", EXPAND(USB_MTP_DEVICE));
int fd = open(EXPAND(USB_MTP_DEVICE), O_RDWR);
#else
int fd = open("/dev/mtp_usb", O_RDWR);
#endif
if (fd >= 0) {
MTPD("fd: %d\n", fd);
server = new MtpServer(fd, mtpdb, usePtp, 0, 0664, 0775);
refserver = server;
MTPI("created new mtpserver object\n");
} else {
MTPE("could not open MTP driver, errno: %d\n", errno);
return -1;
}
return 0;
}
void twmtp_MtpServer::run()
{
MTPD("running in twmtp\n");
server->run();
}
void twmtp_MtpServer::cleanup()
{
android::Mutex sMutex;
android::Mutex::Autolock autoLock(sMutex);
if (server) {
delete server;
} else {
MTPD("server is null in cleanup");
}
}
void twmtp_MtpServer::send_object_added(int handle)
{
android::Mutex sMutex;
android::Mutex::Autolock autoLock(sMutex);
if (server)
server->sendObjectAdded(handle);
else
MTPD("server is null in send_object_added");
}
void twmtp_MtpServer::send_object_removed(int handle)
{
android::Mutex sMutex;
android::Mutex::Autolock autoLock(sMutex);
if (server)
server->sendObjectRemoved(handle);
else
MTPD("server is null in send_object_removed");
}
void twmtp_MtpServer::add_storage()
{
android::Mutex sMutex;
android::Mutex::Autolock autoLock(sMutex);
MTPI("adding internal storage\n");
for (unsigned int i = 0; i < stores->size(); ++i) {
std::string pathStr = stores->at(i)->mount;
if (!pathStr.empty()) {
std::string descriptionStr = stores->at(i)->display;
int storageID = stores->at(i)->mtpid;
long reserveSpace = 1;
bool removable = false;
long maxFileSize = stores->at(i)->maxFileSize;
if (descriptionStr != "") {
MtpStorage* storage = new MtpStorage(storageID, &pathStr[0], &descriptionStr[0], reserveSpace, removable, maxFileSize, refserver);
server->addStorage(storage);
}
}
}
}
void twmtp_MtpServer::remove_storage(int storageId)
{
android::Mutex sMutex;
android::Mutex::Autolock autoLock(sMutex);
if (server) {
MtpStorage* storage = server->getStorage(storageId);
if (storage) {
MTPD("twmtp_MtpServer::remove_storage calling removeStorage\n");
server->removeStorage(storage);
}
} else
MTPD("server is null in remove_storage");
MTPD("twmtp_MtpServer::remove_storage DONE\n");
}
int twmtp_MtpServer::mtppipe_thread(void)
{
if (mtp_read_pipe == -1) {
MTPD("mtppipe_thread exiting because mtp_read_pipe not set\n");
return 0;
}
MTPD("Starting twmtp_MtpServer::mtppipe_thread\n");
int read_count;
struct mtpmsg mtp_message;
while (1) {
read_count = ::read(mtp_read_pipe, &mtp_message, sizeof(mtp_message));
MTPD("read %i from mtppipe\n", read_count);
if (read_count == sizeof(mtp_message)) {
if (mtp_message.message_type == MTP_MESSAGE_ADD_STORAGE) {
MTPI("mtppipe add storage %i '%s'\n", mtp_message.storage_id, mtp_message.path);
long reserveSpace = 1;
bool removable = false;
MtpStorage* storage = new MtpStorage(mtp_message.storage_id, mtp_message.path, mtp_message.display, reserveSpace, removable, mtp_message.maxFileSize, refserver);
server->addStorage(storage);
MTPD("mtppipe done adding storage\n");
} else if (mtp_message.message_type == MTP_MESSAGE_REMOVE_STORAGE) {
MTPI("mtppipe remove storage %i\n", mtp_message.storage_id);
remove_storage(mtp_message.storage_id);
MTPD("mtppipe done removing storage\n");
} else {
MTPE("Unknown mtppipe message value: %i\n", mtp_message.message_type);
}
} else {
MTPE("twmtp_MtpServer::mtppipe_thread unexpected read_count %i\n", read_count);
close(mtp_read_pipe);
break;
}
}
MTPD("twmtp_MtpServer::mtppipe_thread closing\n");
return 0;
}
void twmtp_MtpServer::set_read_pipe(int pipe)
{
mtp_read_pipe = pipe;
}