/*
* Copyright (C) 2008 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 <stdlib.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fs_mgr.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <inttypes.h>
#include <ctype.h>
#define LOG_TAG "VoldCmdListener"
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <sysutils/SocketClient.h>
#include <private/android_filesystem_config.h>
#include "CommandListener.h"
#include "VolumeManager.h"
#include "VolumeBase.h"
#include "ResponseCode.h"
#include "Process.h"
#include "Loop.h"
#include "Devmapper.h"
#include "MoveTask.h"
#include "TrimTask.h"
#define DUMP_ARGS 0
#define DEBUG_APPFUSE 0
CommandListener::CommandListener() :
FrameworkListener("vold", true) {
registerCmd(new DumpCmd());
registerCmd(new VolumeCmd());
registerCmd(new AsecCmd());
registerCmd(new ObbCmd());
registerCmd(new StorageCmd());
registerCmd(new FstrimCmd());
registerCmd(new AppFuseCmd());
}
#if DUMP_ARGS
void CommandListener::dumpArgs(int argc, char **argv, int argObscure) {
char buffer[4096];
char *p = buffer;
memset(buffer, 0, sizeof(buffer));
int i;
for (i = 0; i < argc; i++) {
unsigned int len = strlen(argv[i]) + 1; // Account for space
if (i == argObscure) {
len += 2; // Account for {}
}
if (((p - buffer) + len) < (sizeof(buffer)-1)) {
if (i == argObscure) {
*p++ = '{';
*p++ = '}';
*p++ = ' ';
continue;
}
strcpy(p, argv[i]);
p+= strlen(argv[i]);
if (i != (argc -1)) {
*p++ = ' ';
}
}
}
SLOGD("%s", buffer);
}
#else
void CommandListener::dumpArgs(int /*argc*/, char ** /*argv*/, int /*argObscure*/) { }
#endif
int CommandListener::sendGenericOkFail(SocketClient *cli, int cond) {
if (!cond) {
return cli->sendMsg(ResponseCode::CommandOkay, "Command succeeded", false);
} else {
return cli->sendMsg(ResponseCode::OperationFailed, "Command failed", false);
}
}
CommandListener::DumpCmd::DumpCmd() :
VoldCommand("dump") {
}
int CommandListener::DumpCmd::runCommand(SocketClient *cli,
int /*argc*/, char ** /*argv*/) {
cli->sendMsg(0, "Dumping loop status", false);
if (Loop::dumpState(cli)) {
cli->sendMsg(ResponseCode::CommandOkay, "Loop dump failed", true);
}
cli->sendMsg(0, "Dumping DM status", false);
if (Devmapper::dumpState(cli)) {
cli->sendMsg(ResponseCode::CommandOkay, "Devmapper dump failed", true);
}
cli->sendMsg(0, "Dumping mounted filesystems", false);
FILE *fp = fopen("/proc/mounts", "r");
if (fp) {
char line[1024];
while (fgets(line, sizeof(line), fp)) {
line[strlen(line)-1] = '\0';
cli->sendMsg(0, line, false);;
}
fclose(fp);
}
cli->sendMsg(ResponseCode::CommandOkay, "dump complete", false);
return 0;
}
CommandListener::VolumeCmd::VolumeCmd() :
VoldCommand("volume") {
}
int CommandListener::VolumeCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
dumpArgs(argc, argv, -1);
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
return 0;
}
VolumeManager *vm = VolumeManager::Instance();
std::lock_guard<std::mutex> lock(vm->getLock());
// TODO: tease out methods not directly related to volumes
std::string cmd(argv[1]);
if (cmd == "reset") {
return sendGenericOkFail(cli, vm->reset());
} else if (cmd == "shutdown") {
return sendGenericOkFail(cli, vm->shutdown());
} else if (cmd == "debug") {
return sendGenericOkFail(cli, vm->setDebug(true));
} else if (cmd == "partition" && argc > 3) {
// partition [diskId] [public|private|mixed] [ratio]
std::string id(argv[2]);
auto disk = vm->findDisk(id);
if (disk == nullptr) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown disk", false);
}
std::string type(argv[3]);
if (type == "public") {
return sendGenericOkFail(cli, disk->partitionPublic());
} else if (type == "private") {
return sendGenericOkFail(cli, disk->partitionPrivate());
} else if (type == "mixed") {
if (argc < 4) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
}
int frac = atoi(argv[4]);
return sendGenericOkFail(cli, disk->partitionMixed(frac));
} else {
return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
}
} else if (cmd == "mkdirs" && argc > 2) {
// mkdirs [path]
return sendGenericOkFail(cli, vm->mkdirs(argv[2]));
} else if (cmd == "user_added" && argc > 3) {
// user_added [user] [serial]
return sendGenericOkFail(cli, vm->onUserAdded(atoi(argv[2]), atoi(argv[3])));
} else if (cmd == "user_removed" && argc > 2) {
// user_removed [user]
return sendGenericOkFail(cli, vm->onUserRemoved(atoi(argv[2])));
} else if (cmd == "user_started" && argc > 2) {
// user_started [user]
return sendGenericOkFail(cli, vm->onUserStarted(atoi(argv[2])));
} else if (cmd == "user_stopped" && argc > 2) {
// user_stopped [user]
return sendGenericOkFail(cli, vm->onUserStopped(atoi(argv[2])));
} else if (cmd == "mount" && argc > 2) {
// mount [volId] [flags] [user]
std::string id(argv[2]);
auto vol = vm->findVolume(id);
if (vol == nullptr) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
}
int mountFlags = (argc > 3) ? atoi(argv[3]) : 0;
userid_t mountUserId = (argc > 4) ? atoi(argv[4]) : -1;
vol->setMountFlags(mountFlags);
vol->setMountUserId(mountUserId);
int res = vol->mount();
if (mountFlags & android::vold::VolumeBase::MountFlags::kPrimary) {
vm->setPrimary(vol);
}
return sendGenericOkFail(cli, res);
} else if (cmd == "unmount" && argc > 2) {
// unmount [volId]
std::string id(argv[2]);
auto vol = vm->findVolume(id);
if (vol == nullptr) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
}
return sendGenericOkFail(cli, vol->unmount());
} else if (cmd == "format" && argc > 3) {
// format [volId] [fsType|auto]
std::string id(argv[2]);
std::string fsType(argv[3]);
auto vol = vm->findVolume(id);
if (vol == nullptr) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
}
return sendGenericOkFail(cli, vol->format(fsType));
} else if (cmd == "move_storage" && argc > 3) {
// move_storage [fromVolId] [toVolId]
auto fromVol = vm->findVolume(std::string(argv[2]));
auto toVol = vm->findVolume(std::string(argv[3]));
if (fromVol == nullptr || toVol == nullptr) {
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
}
(new android::vold::MoveTask(fromVol, toVol))->start();
return sendGenericOkFail(cli, 0);
} else if (cmd == "benchmark" && argc > 2) {
// benchmark [volId]
std::string id(argv[2]);
nsecs_t res = vm->benchmarkPrivate(id);
return cli->sendMsg(ResponseCode::CommandOkay,
android::base::StringPrintf("%" PRId64, res).c_str(), false);
} else if (cmd == "forget_partition" && argc > 2) {
// forget_partition [partGuid]
std::string partGuid(argv[2]);
return sendGenericOkFail(cli, vm->forgetPartition(partGuid));
} else if (cmd == "remount_uid" && argc > 3) {
// remount_uid [uid] [none|default|read|write]
uid_t uid = atoi(argv[2]);
std::string mode(argv[3]);
return sendGenericOkFail(cli, vm->remountUid(uid, mode));
}
return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
}
CommandListener::StorageCmd::StorageCmd() :
VoldCommand("storage") {
}
int CommandListener::StorageCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
/* Guarantied to be initialized by vold's main() before the CommandListener is active */
extern struct fstab *fstab;
dumpArgs(argc, argv, -1);
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
return 0;
}
if (!strcmp(argv[1], "mountall")) {
if (argc != 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: mountall", false);
return 0;
}
fs_mgr_mount_all(fstab, MOUNT_MODE_DEFAULT);
cli->sendMsg(ResponseCode::CommandOkay, "Mountall ran successfully", false);
return 0;
}
if (!strcmp(argv[1], "users")) {
DIR *dir;
struct dirent *de;
if (argc < 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument: user <mountpoint>", false);
return 0;
}
if (!(dir = opendir("/proc"))) {
cli->sendMsg(ResponseCode::OperationFailed, "Failed to open /proc", true);
return 0;
}
while ((de = readdir(dir))) {
int pid = Process::getPid(de->d_name);
if (pid < 0) {
continue;
}
char processName[255];
Process::getProcessName(pid, processName, sizeof(processName));
if (Process::checkFileDescriptorSymLinks(pid, argv[2]) ||
Process::checkFileMaps(pid, argv[2]) ||
Process::checkSymLink(pid, argv[2], "cwd") ||
Process::checkSymLink(pid, argv[2], "root") ||
Process::checkSymLink(pid, argv[2], "exe")) {
char msg[1024];
snprintf(msg, sizeof(msg), "%d %s", pid, processName);
cli->sendMsg(ResponseCode::StorageUsersListResult, msg, false);
}
}
closedir(dir);
cli->sendMsg(ResponseCode::CommandOkay, "Storage user list complete", false);
} else {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown storage cmd", false);
}
return 0;
}
CommandListener::AsecCmd::AsecCmd() :
VoldCommand("asec") {
}
void CommandListener::AsecCmd::listAsecsInDirectory(SocketClient *cli, const char *directory) {
DIR *d = opendir(directory);
if (!d) {
cli->sendMsg(ResponseCode::OperationFailed, "Failed to open asec dir", true);
return;
}
size_t dirent_len = offsetof(struct dirent, d_name) +
fpathconf(dirfd(d), _PC_NAME_MAX) + 1;
struct dirent *dent = (struct dirent *) malloc(dirent_len);
if (dent == NULL) {
cli->sendMsg(ResponseCode::OperationFailed, "Failed to allocate memory", true);
return;
}
struct dirent *result;
while (!readdir_r(d, dent, &result) && result != NULL) {
if (dent->d_name[0] == '.')
continue;
if (dent->d_type != DT_REG)
continue;
size_t name_len = strlen(dent->d_name);
if (name_len > 5 && name_len < 260 &&
!strcmp(&dent->d_name[name_len - 5], ".asec")) {
char id[255];
memset(id, 0, sizeof(id));
strlcpy(id, dent->d_name, name_len - 4);
cli->sendMsg(ResponseCode::AsecListResult, id, false);
}
}
closedir(d);
free(dent);
}
int CommandListener::AsecCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
return 0;
}
VolumeManager *vm = VolumeManager::Instance();
int rc = 0;
if (!strcmp(argv[1], "list")) {
dumpArgs(argc, argv, -1);
listAsecsInDirectory(cli, VolumeManager::SEC_ASECDIR_EXT);
listAsecsInDirectory(cli, VolumeManager::SEC_ASECDIR_INT);
} else if (!strcmp(argv[1], "create")) {
dumpArgs(argc, argv, 5);
if (argc != 8) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: asec create <container-id> <size_mb> <fstype> <key> <ownerUid> "
"<isExternal>", false);
return 0;
}
unsigned long numSectors = (atoi(argv[3]) * (1024 * 1024)) / 512;
const bool isExternal = (atoi(argv[7]) == 1);
rc = vm->createAsec(argv[2], numSectors, argv[4], argv[5], atoi(argv[6]), isExternal);
} else if (!strcmp(argv[1], "resize")) {
dumpArgs(argc, argv, -1);
if (argc != 5) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec resize <container-id> <size_mb> <key>", false);
return 0;
}
unsigned long numSectors = (atoi(argv[3]) * (1024 * 1024)) / 512;
rc = vm->resizeAsec(argv[2], numSectors, argv[4]);
} else if (!strcmp(argv[1], "finalize")) {
dumpArgs(argc, argv, -1);
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec finalize <container-id>", false);
return 0;
}
rc = vm->finalizeAsec(argv[2]);
} else if (!strcmp(argv[1], "fixperms")) {
dumpArgs(argc, argv, -1);
if (argc != 5) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fixperms <container-id> <gid> <filename>", false);
return 0;
}
char *endptr;
gid_t gid = (gid_t) strtoul(argv[3], &endptr, 10);
if (*endptr != '\0') {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fixperms <container-id> <gid> <filename>", false);
return 0;
}
rc = vm->fixupAsecPermissions(argv[2], gid, argv[4]);
} else if (!strcmp(argv[1], "destroy")) {
dumpArgs(argc, argv, -1);
if (argc < 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec destroy <container-id> [force]", false);
return 0;
}
bool force = false;
if (argc > 3 && !strcmp(argv[3], "force")) {
force = true;
}
rc = vm->destroyAsec(argv[2], force);
} else if (!strcmp(argv[1], "mount")) {
dumpArgs(argc, argv, 3);
if (argc != 6) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: asec mount <namespace-id> <key> <ownerUid> <ro|rw>", false);
return 0;
}
bool readOnly = true;
if (!strcmp(argv[5], "rw")) {
readOnly = false;
}
rc = vm->mountAsec(argv[2], argv[3], atoi(argv[4]), readOnly);
} else if (!strcmp(argv[1], "unmount")) {
dumpArgs(argc, argv, -1);
if (argc < 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec unmount <container-id> [force]", false);
return 0;
}
bool force = false;
if (argc > 3 && !strcmp(argv[3], "force")) {
force = true;
}
rc = vm->unmountAsec(argv[2], force);
} else if (!strcmp(argv[1], "rename")) {
dumpArgs(argc, argv, -1);
if (argc != 4) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: asec rename <old_id> <new_id>", false);
return 0;
}
rc = vm->renameAsec(argv[2], argv[3]);
} else if (!strcmp(argv[1], "path")) {
dumpArgs(argc, argv, -1);
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec path <container-id>", false);
return 0;
}
char path[255];
if (!(rc = vm->getAsecMountPath(argv[2], path, sizeof(path)))) {
cli->sendMsg(ResponseCode::AsecPathResult, path, false);
return 0;
}
} else if (!strcmp(argv[1], "fspath")) {
dumpArgs(argc, argv, -1);
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fspath <container-id>", false);
return 0;
}
char path[255];
if (!(rc = vm->getAsecFilesystemPath(argv[2], path, sizeof(path)))) {
cli->sendMsg(ResponseCode::AsecPathResult, path, false);
return 0;
}
} else {
dumpArgs(argc, argv, -1);
cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown asec cmd", false);
}
if (!rc) {
cli->sendMsg(ResponseCode::CommandOkay, "asec operation succeeded", false);
} else {
rc = ResponseCode::convertFromErrno();
cli->sendMsg(rc, "asec operation failed", true);
}
return 0;
}
CommandListener::ObbCmd::ObbCmd() :
VoldCommand("obb") {
}
int CommandListener::ObbCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
return 0;
}
VolumeManager *vm = VolumeManager::Instance();
int rc = 0;
if (!strcmp(argv[1], "list")) {
dumpArgs(argc, argv, -1);
rc = vm->listMountedObbs(cli);
} else if (!strcmp(argv[1], "mount")) {
dumpArgs(argc, argv, 3);
if (argc != 5) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: obb mount <filename> <key> <ownerGid>", false);
return 0;
}
rc = vm->mountObb(argv[2], argv[3], atoi(argv[4]));
} else if (!strcmp(argv[1], "unmount")) {
dumpArgs(argc, argv, -1);
if (argc < 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: obb unmount <source file> [force]", false);
return 0;
}
bool force = false;
if (argc > 3 && !strcmp(argv[3], "force")) {
force = true;
}
rc = vm->unmountObb(argv[2], force);
} else if (!strcmp(argv[1], "path")) {
dumpArgs(argc, argv, -1);
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: obb path <source file>", false);
return 0;
}
char path[255];
if (!(rc = vm->getObbMountPath(argv[2], path, sizeof(path)))) {
cli->sendMsg(ResponseCode::AsecPathResult, path, false);
return 0;
}
} else {
dumpArgs(argc, argv, -1);
cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown obb cmd", false);
}
if (!rc) {
cli->sendMsg(ResponseCode::CommandOkay, "obb operation succeeded", false);
} else {
rc = ResponseCode::convertFromErrno();
cli->sendMsg(rc, "obb operation failed", true);
}
return 0;
}
CommandListener::FstrimCmd::FstrimCmd() :
VoldCommand("fstrim") {
}
int CommandListener::FstrimCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
if ((cli->getUid() != 0) && (cli->getUid() != AID_SYSTEM)) {
cli->sendMsg(ResponseCode::CommandNoPermission, "No permission to run fstrim commands", false);
return 0;
}
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
return 0;
}
VolumeManager *vm = VolumeManager::Instance();
std::lock_guard<std::mutex> lock(vm->getLock());
int flags = 0;
std::string cmd(argv[1]);
if (cmd == "dotrim") {
flags = 0;
} else if (cmd == "dotrimbench") {
flags = android::vold::TrimTask::Flags::kBenchmarkAfter;
} else if (cmd == "dodtrim") {
flags = android::vold::TrimTask::Flags::kDeepTrim;
} else if (cmd == "dodtrimbench") {
flags = android::vold::TrimTask::Flags::kDeepTrim
| android::vold::TrimTask::Flags::kBenchmarkAfter;
}
(new android::vold::TrimTask(flags))->start();
return sendGenericOkFail(cli, 0);
}
static size_t kAppFuseMaxMountPointName = 32;
static android::status_t getMountPath(uid_t uid, const std::string& name, std::string* path) {
if (name.size() > kAppFuseMaxMountPointName) {
LOG(ERROR) << "AppFuse mount name is too long.";
return -EINVAL;
}
for (size_t i = 0; i < name.size(); i++) {
if (!isalnum(name[i])) {
LOG(ERROR) << "AppFuse mount name contains invalid character.";
return -EINVAL;
}
}
*path = android::base::StringPrintf("/mnt/appfuse/%d_%s", uid, name.c_str());
return android::OK;
}
static android::status_t mountInNamespace(uid_t uid, int device_fd, const std::string& path) {
// Remove existing mount.
android::vold::ForceUnmount(path);
const auto opts = android::base::StringPrintf(
"fd=%i,"
"rootmode=40000,"
"default_permissions,"
"allow_other,"
"user_id=%d,group_id=%d,"
"context=\"u:object_r:app_fuse_file:s0\","
"fscontext=u:object_r:app_fusefs:s0",
device_fd,
uid,
uid);
const int result = TEMP_FAILURE_RETRY(mount(
"/dev/fuse", path.c_str(), "fuse",
MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()));
if (result != 0) {
PLOG(ERROR) << "Failed to mount " << path;
return -errno;
}
return android::OK;
}
static android::status_t runCommandInNamespace(const std::string& command,
uid_t uid,
pid_t pid,
const std::string& path,
int device_fd) {
if (DEBUG_APPFUSE) {
LOG(DEBUG) << "Run app fuse command " << command << " for the path " << path
<< " in namespace " << uid;
}
const android::vold::ScopedDir dir(opendir("/proc"));
if (dir.get() == nullptr) {
PLOG(ERROR) << "Failed to open /proc";
return -errno;
}
// Obtains process file descriptor.
const std::string pid_str = android::base::StringPrintf("%d", pid);
const android::vold::ScopedFd pid_fd(
openat(dirfd(dir.get()), pid_str.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
if (pid_fd.get() == -1) {
PLOG(ERROR) << "Failed to open /proc/" << pid;
return -errno;
}
// Check UID of process.
{
struct stat sb;
const int result = fstat(pid_fd.get(), &sb);
if (result == -1) {
PLOG(ERROR) << "Failed to stat /proc/" << pid;
return -errno;
}
if (sb.st_uid != uid) {
LOG(ERROR) << "Mismatch UID expected=" << uid << ", actual=" << sb.st_uid;
return -EPERM;
}
}
// Matches so far, but refuse to touch if in root namespace
{
char rootName[PATH_MAX];
char pidName[PATH_MAX];
const int root_result =
android::vold::SaneReadLinkAt(dirfd(dir.get()), "1/ns/mnt", rootName, PATH_MAX);
const int pid_result =
android::vold::SaneReadLinkAt(pid_fd.get(), "ns/mnt", pidName, PATH_MAX);
if (root_result == -1) {
LOG(ERROR) << "Failed to readlink for /proc/1/ns/mnt";
return -EPERM;
}
if (pid_result == -1) {
LOG(ERROR) << "Failed to readlink for /proc/" << pid << "/ns/mnt";
return -EPERM;
}
if (!strcmp(rootName, pidName)) {
LOG(ERROR) << "Don't mount appfuse in root namespace";
return -EPERM;
}
}
// We purposefully leave the namespace open across the fork
android::vold::ScopedFd ns_fd(openat(pid_fd.get(), "ns/mnt", O_RDONLY));
if (ns_fd.get() < 0) {
PLOG(ERROR) << "Failed to open namespace for /proc/" << pid << "/ns/mnt";
return -errno;
}
int child = fork();
if (child == 0) {
if (setns(ns_fd.get(), CLONE_NEWNS) != 0) {
PLOG(ERROR) << "Failed to setns";
_exit(-errno);
}
if (command == "mount") {
_exit(mountInNamespace(uid, device_fd, path));
} else if (command == "unmount") {
android::vold::ForceUnmount(path);
_exit(android::OK);
} else {
LOG(ERROR) << "Unknown appfuse command " << command;
_exit(-EPERM);
}
}
if (child == -1) {
PLOG(ERROR) << "Failed to folk child process";
return -errno;
}
android::status_t status;
TEMP_FAILURE_RETRY(waitpid(child, &status, 0));
return status;
}
CommandListener::AppFuseCmd::AppFuseCmd() : VoldCommand("appfuse") {}
int CommandListener::AppFuseCmd::runCommand(SocketClient *cli, int argc, char **argv) {
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing argument", false);
return 0;
}
const std::string command(argv[1]);
if (command == "mount" && argc == 5) {
const uid_t uid = atoi(argv[2]);
const pid_t pid = atoi(argv[3]);
const std::string name(argv[4]);
// Check mount point name.
std::string path;
if (getMountPath(uid, name, &path) != android::OK) {
return cli->sendMsg(ResponseCode::CommandParameterError,
"Invalid mount point name.",
false);
}
// Create directories.
{
const android::status_t result = android::vold::PrepareDir(path, 0700, 0, 0);
if (result != android::OK) {
PLOG(ERROR) << "Failed to prepare directory " << path;
return sendGenericOkFail(cli, result);
}
}
// Open device FD.
android::vold::ScopedFd device_fd(open("/dev/fuse", O_RDWR));
if (device_fd.get() == -1) {
PLOG(ERROR) << "Failed to open /dev/fuse";
return sendGenericOkFail(cli, -errno);
}
// Mount.
{
const android::status_t result =
runCommandInNamespace(command, uid, pid, path, device_fd.get());
if (result != android::OK) {
return sendGenericOkFail(cli, result);
}
}
return sendFd(cli, device_fd.get());
} else if (command == "unmount" && argc == 5) {
const uid_t uid = atoi(argv[2]);
const uid_t pid = atoi(argv[3]);
const std::string name(argv[4]);
// Check mount point name.
std::string path;
if (getMountPath(uid, name, &path) != android::OK) {
return cli->sendMsg(ResponseCode::CommandParameterError,
"Invalid mount point name.",
false);
}
const android::status_t result =
runCommandInNamespace(command, uid, pid, path, -1 /* device_fd */);
return sendGenericOkFail(cli, result);
}
return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown appfuse cmd", false);
}
android::status_t CommandListener::AppFuseCmd::sendFd(SocketClient *cli, int fd) {
struct iovec data;
char dataBuffer[128];
char controlBuffer[CMSG_SPACE(sizeof(int))];
struct msghdr message;
// Message.
memset(&message, 0, sizeof(struct msghdr));
message.msg_iov = &data;
message.msg_iovlen = 1;
message.msg_control = controlBuffer;
message.msg_controllen = CMSG_SPACE(sizeof(int));
// Data.
data.iov_base = dataBuffer;
data.iov_len = snprintf(dataBuffer,
sizeof(dataBuffer),
"200 %d AppFuse command succeeded",
cli->getCmdNum()) + 1;
// Control.
struct cmsghdr* const controlMessage = CMSG_FIRSTHDR(&message);
memset(controlBuffer, 0, CMSG_SPACE(sizeof(int)));
controlMessage->cmsg_level = SOL_SOCKET;
controlMessage->cmsg_type = SCM_RIGHTS;
controlMessage->cmsg_len = CMSG_LEN(sizeof(int));
*((int *) CMSG_DATA(controlMessage)) = fd;
const int result = TEMP_FAILURE_RETRY(sendmsg(cli->getSocket(), &message, 0));
if (result == -1) {
PLOG(ERROR) << "Failed to send FD from vold";
return -errno;
}
return android::OK;
}