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platform_system_core/adb/shell_service.cpp
Josh Gao 42afe2033f adb: don't dup local socket fd. 
SIGHUP handling depends on the local socket fd being fully closed in
order to trigger an event on its counterpart. Release the local socket
fd inside of Subprocess when returning it to ensure this.

Bug: http://b/29565233
Change-Id: I13b17bcddf0b396a5f4880f9e410fbbf24d9370d
2016-06-22 15:57:12 -07:00

773 lines
28 KiB
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/*
* 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.
*/
// Functionality for launching and managing shell subprocesses.
//
// There are two types of subprocesses, PTY or raw. PTY is typically used for
// an interactive session, raw for non-interactive. There are also two methods
// of communication with the subprocess, passing raw data or using a simple
// protocol to wrap packets. The protocol allows separating stdout/stderr and
// passing the exit code back, but is not backwards compatible.
// ----------------+--------------------------------------
// Type Protocol | Exit code? Separate stdout/stderr?
// ----------------+--------------------------------------
// PTY No | No No
// Raw No | No No
// PTY Yes | Yes No
// Raw Yes | Yes Yes
// ----------------+--------------------------------------
//
// Non-protocol subprocesses work by passing subprocess stdin/out/err through
// a single pipe which is registered with a local socket in adbd. The local
// socket uses the fdevent loop to pass raw data between this pipe and the
// transport, which then passes data back to the adb client. Cleanup is done by
// waiting in a separate thread for the subprocesses to exit and then signaling
// a separate fdevent to close out the local socket from the main loop.
//
// ------------------+-------------------------+------------------------------
// Subprocess | adbd subprocess thread | adbd main fdevent loop
// ------------------+-------------------------+------------------------------
// | |
// stdin/out/err <-----------------------------> LocalSocket
// | | |
// | | Block on exit |
// | | * |
// v | * |
// Exit ---> Unblock |
// | | |
// | v |
// | Notify shell exit FD ---> Close LocalSocket
// ------------------+-------------------------+------------------------------
//
// The protocol requires the thread to intercept stdin/out/err in order to
// wrap/unwrap data with shell protocol packets.
//
// ------------------+-------------------------+------------------------------
// Subprocess | adbd subprocess thread | adbd main fdevent loop
// ------------------+-------------------------+------------------------------
// | |
// stdin/out <---> Protocol <---> LocalSocket
// stderr ---> Protocol ---> LocalSocket
// | | |
// v | |
// Exit ---> Exit code protocol ---> LocalSocket
// | | |
// | v |
// | Notify shell exit FD ---> Close LocalSocket
// ------------------+-------------------------+------------------------------
//
// An alternate approach is to put the protocol wrapping/unwrapping in the main
// fdevent loop, which has the advantage of being able to re-use the existing
// select() code for handling data streams. However, implementation turned out
// to be more complex due to partial reads and non-blocking I/O so this model
// was chosen instead.
#define TRACE_TAG SHELL
#include "sysdeps.h"
#include "shell_service.h"
#include <errno.h>
#include <pty.h>
#include <pwd.h>
#include <sys/select.h>
#include <termios.h>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <paths.h>
#include <log/log.h>
#include "adb.h"
#include "adb_io.h"
#include "adb_trace.h"
#include "adb_utils.h"
#include "security_log_tags.h"
namespace {
void init_subproc_child()
{
setsid();
// Set OOM score adjustment to prevent killing
int fd = adb_open("/proc/self/oom_score_adj", O_WRONLY | O_CLOEXEC);
if (fd >= 0) {
adb_write(fd, "0", 1);
adb_close(fd);
} else {
D("adb: unable to update oom_score_adj");
}
}
// Reads from |fd| until close or failure.
std::string ReadAll(int fd) {
char buffer[512];
std::string received;
while (1) {
int bytes = adb_read(fd, buffer, sizeof(buffer));
if (bytes <= 0) {
break;
}
received.append(buffer, bytes);
}
return received;
}
// Creates a socketpair and saves the endpoints to |fd1| and |fd2|.
bool CreateSocketpair(ScopedFd* fd1, ScopedFd* fd2) {
int sockets[2];
if (adb_socketpair(sockets) < 0) {
PLOG(ERROR) << "cannot create socket pair";
return false;
}
fd1->Reset(sockets[0]);
fd2->Reset(sockets[1]);
return true;
}
class Subprocess {
public:
Subprocess(const std::string& command, const char* terminal_type,
SubprocessType type, SubprocessProtocol protocol);
~Subprocess();
const std::string& command() const { return command_; }
int ReleaseLocalSocket() { return local_socket_sfd_.Release(); }
pid_t pid() const { return pid_; }
// Sets up FDs, forks a subprocess, starts the subprocess manager thread,
// and exec's the child. Returns false and sets error on failure.
bool ForkAndExec(std::string* _Nonnull error);
// Start the subprocess manager thread. Consumes the subprocess, regardless of success.
// Returns false and sets error on failure.
static bool StartThread(std::unique_ptr<Subprocess> subprocess,
std::string* _Nonnull error);
private:
// Opens the file at |pts_name|.
int OpenPtyChildFd(const char* pts_name, ScopedFd* error_sfd);
static void ThreadHandler(void* userdata);
void PassDataStreams();
void WaitForExit();
ScopedFd* SelectLoop(fd_set* master_read_set_ptr,
fd_set* master_write_set_ptr);
// Input/output stream handlers. Success returns nullptr, failure returns
// a pointer to the failed FD.
ScopedFd* PassInput();
ScopedFd* PassOutput(ScopedFd* sfd, ShellProtocol::Id id);
const std::string command_;
const std::string terminal_type_;
bool make_pty_raw_ = false;
SubprocessType type_;
SubprocessProtocol protocol_;
pid_t pid_ = -1;
ScopedFd local_socket_sfd_;
// Shell protocol variables.
ScopedFd stdinout_sfd_, stderr_sfd_, protocol_sfd_;
std::unique_ptr<ShellProtocol> input_, output_;
size_t input_bytes_left_ = 0;
DISALLOW_COPY_AND_ASSIGN(Subprocess);
};
Subprocess::Subprocess(const std::string& command, const char* terminal_type,
SubprocessType type, SubprocessProtocol protocol)
: command_(command),
terminal_type_(terminal_type ? terminal_type : ""),
type_(type),
protocol_(protocol) {
// If we aren't using the shell protocol we must allocate a PTY to properly close the
// subprocess. PTYs automatically send SIGHUP to the slave-side process when the master side
// of the PTY closes, which we rely on. If we use a raw pipe, processes that don't read/write,
// e.g. screenrecord, will never notice the broken pipe and terminate.
// The shell protocol doesn't require a PTY because it's always monitoring the local socket FD
// with select() and will send SIGHUP manually to the child process.
if (protocol_ == SubprocessProtocol::kNone && type_ == SubprocessType::kRaw) {
// Disable PTY input/output processing since the client is expecting raw data.
D("Can't create raw subprocess without shell protocol, using PTY in raw mode instead");
type_ = SubprocessType::kPty;
make_pty_raw_ = true;
}
}
Subprocess::~Subprocess() {
WaitForExit();
}
bool Subprocess::ForkAndExec(std::string* error) {
ScopedFd child_stdinout_sfd, child_stderr_sfd;
ScopedFd parent_error_sfd, child_error_sfd;
char pts_name[PATH_MAX];
if (command_.empty()) {
__android_log_security_bswrite(SEC_TAG_ADB_SHELL_INTERACTIVE, "");
} else {
__android_log_security_bswrite(SEC_TAG_ADB_SHELL_CMD, command_.c_str());
}
// Create a socketpair for the fork() child to report any errors back to the parent. Since we
// use threads, logging directly from the child might deadlock due to locks held in another
// thread during the fork.
if (!CreateSocketpair(&parent_error_sfd, &child_error_sfd)) {
*error = android::base::StringPrintf(
"failed to create pipe for subprocess error reporting: %s", strerror(errno));
return false;
}
// Construct the environment for the child before we fork.
passwd* pw = getpwuid(getuid());
std::unordered_map<std::string, std::string> env;
if (environ) {
char** current = environ;
while (char* env_cstr = *current++) {
std::string env_string = env_cstr;
char* delimiter = strchr(env_string.c_str(), '=');
// Drop any values that don't contain '='.
if (delimiter) {
*delimiter++ = '\0';
env[env_string.c_str()] = delimiter;
}
}
}
if (pw != nullptr) {
// TODO: $HOSTNAME? Normally bash automatically sets that, but mksh doesn't.
env["HOME"] = pw->pw_dir;
env["LOGNAME"] = pw->pw_name;
env["USER"] = pw->pw_name;
env["SHELL"] = pw->pw_shell;
}
if (!terminal_type_.empty()) {
env["TERM"] = terminal_type_;
}
std::vector<std::string> joined_env;
for (auto it : env) {
const char* key = it.first.c_str();
const char* value = it.second.c_str();
joined_env.push_back(android::base::StringPrintf("%s=%s", key, value));
}
std::vector<const char*> cenv;
for (const std::string& str : joined_env) {
cenv.push_back(str.c_str());
}
cenv.push_back(nullptr);
if (type_ == SubprocessType::kPty) {
int fd;
pid_ = forkpty(&fd, pts_name, nullptr, nullptr);
if (pid_ > 0) {
stdinout_sfd_.Reset(fd);
}
} else {
if (!CreateSocketpair(&stdinout_sfd_, &child_stdinout_sfd)) {
*error = android::base::StringPrintf("failed to create socketpair for stdin/out: %s",
strerror(errno));
return false;
}
// Raw subprocess + shell protocol allows for splitting stderr.
if (protocol_ == SubprocessProtocol::kShell &&
!CreateSocketpair(&stderr_sfd_, &child_stderr_sfd)) {
*error = android::base::StringPrintf("failed to create socketpair for stderr: %s",
strerror(errno));
return false;
}
pid_ = fork();
}
if (pid_ == -1) {
*error = android::base::StringPrintf("fork failed: %s", strerror(errno));
return false;
}
if (pid_ == 0) {
// Subprocess child.
init_subproc_child();
if (type_ == SubprocessType::kPty) {
child_stdinout_sfd.Reset(OpenPtyChildFd(pts_name, &child_error_sfd));
}
dup2(child_stdinout_sfd.fd(), STDIN_FILENO);
dup2(child_stdinout_sfd.fd(), STDOUT_FILENO);
dup2(child_stderr_sfd.valid() ? child_stderr_sfd.fd() : child_stdinout_sfd.fd(),
STDERR_FILENO);
// exec doesn't trigger destructors, close the FDs manually.
stdinout_sfd_.Reset();
stderr_sfd_.Reset();
child_stdinout_sfd.Reset();
child_stderr_sfd.Reset();
parent_error_sfd.Reset();
close_on_exec(child_error_sfd.fd());
if (command_.empty()) {
execle(_PATH_BSHELL, _PATH_BSHELL, "-", nullptr, cenv.data());
} else {
execle(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr, cenv.data());
}
WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed: ");
WriteFdExactly(child_error_sfd.fd(), strerror(errno));
child_error_sfd.Reset();
_Exit(1);
}
// Subprocess parent.
D("subprocess parent: stdin/stdout FD = %d, stderr FD = %d",
stdinout_sfd_.fd(), stderr_sfd_.fd());
// Wait to make sure the subprocess exec'd without error.
child_error_sfd.Reset();
std::string error_message = ReadAll(parent_error_sfd.fd());
if (!error_message.empty()) {
*error = error_message;
return false;
}
D("subprocess parent: exec completed");
if (protocol_ == SubprocessProtocol::kNone) {
// No protocol: all streams pass through the stdinout FD and hook
// directly into the local socket for raw data transfer.
local_socket_sfd_.Reset(stdinout_sfd_.Release());
} else {
// Shell protocol: create another socketpair to intercept data.
if (!CreateSocketpair(&protocol_sfd_, &local_socket_sfd_)) {
*error = android::base::StringPrintf(
"failed to create socketpair to intercept data: %s", strerror(errno));
kill(pid_, SIGKILL);
return false;
}
D("protocol FD = %d", protocol_sfd_.fd());
input_.reset(new ShellProtocol(protocol_sfd_.fd()));
output_.reset(new ShellProtocol(protocol_sfd_.fd()));
if (!input_ || !output_) {
*error = "failed to allocate shell protocol objects";
kill(pid_, SIGKILL);
return false;
}
// Don't let reads/writes to the subprocess block our thread. This isn't
// likely but could happen under unusual circumstances, such as if we
// write a ton of data to stdin but the subprocess never reads it and
// the pipe fills up.
for (int fd : {stdinout_sfd_.fd(), stderr_sfd_.fd()}) {
if (fd >= 0) {
if (!set_file_block_mode(fd, false)) {
*error = android::base::StringPrintf(
"failed to set non-blocking mode for fd %d", fd);
kill(pid_, SIGKILL);
return false;
}
}
}
}
D("subprocess parent: completed");
return true;
}
bool Subprocess::StartThread(std::unique_ptr<Subprocess> subprocess, std::string* error) {
Subprocess* raw = subprocess.release();
if (!adb_thread_create(ThreadHandler, raw)) {
*error =
android::base::StringPrintf("failed to create subprocess thread: %s", strerror(errno));
kill(raw->pid_, SIGKILL);
return false;
}
return true;
}
int Subprocess::OpenPtyChildFd(const char* pts_name, ScopedFd* error_sfd) {
int child_fd = adb_open(pts_name, O_RDWR | O_CLOEXEC);
if (child_fd == -1) {
// Don't use WriteFdFmt; since we're in the fork() child we don't want
// to allocate any heap memory to avoid race conditions.
const char* messages[] = {"child failed to open pseudo-term slave ",
pts_name, ": ", strerror(errno)};
for (const char* message : messages) {
WriteFdExactly(error_sfd->fd(), message);
}
exit(-1);
}
if (make_pty_raw_) {
termios tattr;
if (tcgetattr(child_fd, &tattr) == -1) {
int saved_errno = errno;
WriteFdExactly(error_sfd->fd(), "tcgetattr failed: ");
WriteFdExactly(error_sfd->fd(), strerror(saved_errno));
exit(-1);
}
cfmakeraw(&tattr);
if (tcsetattr(child_fd, TCSADRAIN, &tattr) == -1) {
int saved_errno = errno;
WriteFdExactly(error_sfd->fd(), "tcsetattr failed: ");
WriteFdExactly(error_sfd->fd(), strerror(saved_errno));
exit(-1);
}
}
return child_fd;
}
void Subprocess::ThreadHandler(void* userdata) {
Subprocess* subprocess = reinterpret_cast<Subprocess*>(userdata);
adb_thread_setname(android::base::StringPrintf(
"shell srvc %d", subprocess->pid()));
D("passing data streams for PID %d", subprocess->pid());
subprocess->PassDataStreams();
D("deleting Subprocess for PID %d", subprocess->pid());
delete subprocess;
}
void Subprocess::PassDataStreams() {
if (!protocol_sfd_.valid()) {
return;
}
// Start by trying to read from the protocol FD, stdout, and stderr.
fd_set master_read_set, master_write_set;
FD_ZERO(&master_read_set);
FD_ZERO(&master_write_set);
for (ScopedFd* sfd : {&protocol_sfd_, &stdinout_sfd_, &stderr_sfd_}) {
if (sfd->valid()) {
FD_SET(sfd->fd(), &master_read_set);
}
}
// Pass data until the protocol FD or both the subprocess pipes die, at
// which point we can't pass any more data.
while (protocol_sfd_.valid() &&
(stdinout_sfd_.valid() || stderr_sfd_.valid())) {
ScopedFd* dead_sfd = SelectLoop(&master_read_set, &master_write_set);
if (dead_sfd) {
D("closing FD %d", dead_sfd->fd());
FD_CLR(dead_sfd->fd(), &master_read_set);
FD_CLR(dead_sfd->fd(), &master_write_set);
if (dead_sfd == &protocol_sfd_) {
// Using SIGHUP is a decent general way to indicate that the
// controlling process is going away. If specific signals are
// needed (e.g. SIGINT), pass those through the shell protocol
// and only fall back on this for unexpected closures.
D("protocol FD died, sending SIGHUP to pid %d", pid_);
kill(pid_, SIGHUP);
// We also need to close the pipes connected to the child process
// so that if it ignores SIGHUP and continues to write data it
// won't fill up the pipe and block.
stdinout_sfd_.Reset();
stderr_sfd_.Reset();
}
dead_sfd->Reset();
}
}
}
namespace {
inline bool ValidAndInSet(const ScopedFd& sfd, fd_set* set) {
return sfd.valid() && FD_ISSET(sfd.fd(), set);
}
} // namespace
ScopedFd* Subprocess::SelectLoop(fd_set* master_read_set_ptr,
fd_set* master_write_set_ptr) {
fd_set read_set, write_set;
int select_n = std::max(std::max(protocol_sfd_.fd(), stdinout_sfd_.fd()),
stderr_sfd_.fd()) + 1;
ScopedFd* dead_sfd = nullptr;
// Keep calling select() and passing data until an FD closes/errors.
while (!dead_sfd) {
memcpy(&read_set, master_read_set_ptr, sizeof(read_set));
memcpy(&write_set, master_write_set_ptr, sizeof(write_set));
if (select(select_n, &read_set, &write_set, nullptr, nullptr) < 0) {
if (errno == EINTR) {
continue;
} else {
PLOG(ERROR) << "select failed, closing subprocess pipes";
stdinout_sfd_.Reset();
stderr_sfd_.Reset();
return nullptr;
}
}
// Read stdout, write to protocol FD.
if (ValidAndInSet(stdinout_sfd_, &read_set)) {
dead_sfd = PassOutput(&stdinout_sfd_, ShellProtocol::kIdStdout);
}
// Read stderr, write to protocol FD.
if (!dead_sfd && ValidAndInSet(stderr_sfd_, &read_set)) {
dead_sfd = PassOutput(&stderr_sfd_, ShellProtocol::kIdStderr);
}
// Read protocol FD, write to stdin.
if (!dead_sfd && ValidAndInSet(protocol_sfd_, &read_set)) {
dead_sfd = PassInput();
// If we didn't finish writing, block on stdin write.
if (input_bytes_left_) {
FD_CLR(protocol_sfd_.fd(), master_read_set_ptr);
FD_SET(stdinout_sfd_.fd(), master_write_set_ptr);
}
}
// Continue writing to stdin; only happens if a previous write blocked.
if (!dead_sfd && ValidAndInSet(stdinout_sfd_, &write_set)) {
dead_sfd = PassInput();
// If we finished writing, go back to blocking on protocol read.
if (!input_bytes_left_) {
FD_SET(protocol_sfd_.fd(), master_read_set_ptr);
FD_CLR(stdinout_sfd_.fd(), master_write_set_ptr);
}
}
} // while (!dead_sfd)
return dead_sfd;
}
ScopedFd* Subprocess::PassInput() {
// Only read a new packet if we've finished writing the last one.
if (!input_bytes_left_) {
if (!input_->Read()) {
// Read() uses ReadFdExactly() which sets errno to 0 on EOF.
if (errno != 0) {
PLOG(ERROR) << "error reading protocol FD "
<< protocol_sfd_.fd();
}
return &protocol_sfd_;
}
if (stdinout_sfd_.valid()) {
switch (input_->id()) {
case ShellProtocol::kIdWindowSizeChange:
int rows, cols, x_pixels, y_pixels;
if (sscanf(input_->data(), "%dx%d,%dx%d",
&rows, &cols, &x_pixels, &y_pixels) == 4) {
winsize ws;
ws.ws_row = rows;
ws.ws_col = cols;
ws.ws_xpixel = x_pixels;
ws.ws_ypixel = y_pixels;
ioctl(stdinout_sfd_.fd(), TIOCSWINSZ, &ws);
}
break;
case ShellProtocol::kIdStdin:
input_bytes_left_ = input_->data_length();
break;
case ShellProtocol::kIdCloseStdin:
if (type_ == SubprocessType::kRaw) {
if (adb_shutdown(stdinout_sfd_.fd(), SHUT_WR) == 0) {
return nullptr;
}
PLOG(ERROR) << "failed to shutdown writes to FD "
<< stdinout_sfd_.fd();
return &stdinout_sfd_;
} else {
// PTYs can't close just input, so rather than close the
// FD and risk losing subprocess output, leave it open.
// This only happens if the client starts a PTY shell
// non-interactively which is rare and unsupported.
// If necessary, the client can manually close the shell
// with `exit` or by killing the adb client process.
D("can't close input for PTY FD %d", stdinout_sfd_.fd());
}
break;
}
}
}
if (input_bytes_left_ > 0) {
int index = input_->data_length() - input_bytes_left_;
int bytes = adb_write(stdinout_sfd_.fd(), input_->data() + index,
input_bytes_left_);
if (bytes == 0 || (bytes < 0 && errno != EAGAIN)) {
if (bytes < 0) {
PLOG(ERROR) << "error reading stdin FD " << stdinout_sfd_.fd();
}
// stdin is done, mark this packet as finished and we'll just start
// dumping any further data received from the protocol FD.
input_bytes_left_ = 0;
return &stdinout_sfd_;
} else if (bytes > 0) {
input_bytes_left_ -= bytes;
}
}
return nullptr;
}
ScopedFd* Subprocess::PassOutput(ScopedFd* sfd, ShellProtocol::Id id) {
int bytes = adb_read(sfd->fd(), output_->data(), output_->data_capacity());
if (bytes == 0 || (bytes < 0 && errno != EAGAIN)) {
// read() returns EIO if a PTY closes; don't report this as an error,
// it just means the subprocess completed.
if (bytes < 0 && !(type_ == SubprocessType::kPty && errno == EIO)) {
PLOG(ERROR) << "error reading output FD " << sfd->fd();
}
return sfd;
}
if (bytes > 0 && !output_->Write(id, bytes)) {
if (errno != 0) {
PLOG(ERROR) << "error reading protocol FD " << protocol_sfd_.fd();
}
return &protocol_sfd_;
}
return nullptr;
}
void Subprocess::WaitForExit() {
int exit_code = 1;
D("waiting for pid %d", pid_);
while (true) {
int status;
if (pid_ == waitpid(pid_, &status, 0)) {
D("post waitpid (pid=%d) status=%04x", pid_, status);
if (WIFSIGNALED(status)) {
exit_code = 0x80 | WTERMSIG(status);
D("subprocess killed by signal %d", WTERMSIG(status));
break;
} else if (!WIFEXITED(status)) {
D("subprocess didn't exit");
break;
} else if (WEXITSTATUS(status) >= 0) {
exit_code = WEXITSTATUS(status);
D("subprocess exit code = %d", WEXITSTATUS(status));
break;
}
}
}
// If we have an open protocol FD send an exit packet.
if (protocol_sfd_.valid()) {
output_->data()[0] = exit_code;
if (output_->Write(ShellProtocol::kIdExit, 1)) {
D("wrote the exit code packet: %d", exit_code);
} else {
PLOG(ERROR) << "failed to write the exit code packet";
}
protocol_sfd_.Reset();
}
// Pass the local socket FD to the shell cleanup fdevent.
if (SHELL_EXIT_NOTIFY_FD >= 0) {
int fd = local_socket_sfd_.fd();
if (WriteFdExactly(SHELL_EXIT_NOTIFY_FD, &fd, sizeof(fd))) {
D("passed fd %d to SHELL_EXIT_NOTIFY_FD (%d) for pid %d",
fd, SHELL_EXIT_NOTIFY_FD, pid_);
// The shell exit fdevent now owns the FD and will close it once
// the last bit of data flushes through.
local_socket_sfd_.Release();
} else {
PLOG(ERROR) << "failed to write fd " << fd
<< " to SHELL_EXIT_NOTIFY_FD (" << SHELL_EXIT_NOTIFY_FD
<< ") for pid " << pid_;
}
}
}
} // namespace
// Create a pipe containing the error.
static int ReportError(SubprocessProtocol protocol, const std::string& message) {
int pipefd[2];
if (pipe(pipefd) != 0) {
LOG(ERROR) << "failed to create pipe to report error";
return -1;
}
std::string buf = android::base::StringPrintf("error: %s\n", message.c_str());
if (protocol == SubprocessProtocol::kShell) {
ShellProtocol::Id id = ShellProtocol::kIdStderr;
uint32_t length = buf.length();
WriteFdExactly(pipefd[1], &id, sizeof(id));
WriteFdExactly(pipefd[1], &length, sizeof(length));
}
WriteFdExactly(pipefd[1], buf.data(), buf.length());
if (protocol == SubprocessProtocol::kShell) {
ShellProtocol::Id id = ShellProtocol::kIdExit;
uint32_t length = 1;
char exit_code = 126;
WriteFdExactly(pipefd[1], &id, sizeof(id));
WriteFdExactly(pipefd[1], &length, sizeof(length));
WriteFdExactly(pipefd[1], &exit_code, sizeof(exit_code));
}
adb_close(pipefd[1]);
return pipefd[0];
}
int StartSubprocess(const char* name, const char* terminal_type,
SubprocessType type, SubprocessProtocol protocol) {
D("starting %s subprocess (protocol=%s, TERM=%s): '%s'",
type == SubprocessType::kRaw ? "raw" : "PTY",
protocol == SubprocessProtocol::kNone ? "none" : "shell",
terminal_type, name);
auto subprocess = std::make_unique<Subprocess>(name, terminal_type, type, protocol);
if (!subprocess) {
LOG(ERROR) << "failed to allocate new subprocess";
return ReportError(protocol, "failed to allocate new subprocess");
}
std::string error;
if (!subprocess->ForkAndExec(&error)) {
LOG(ERROR) << "failed to start subprocess: " << error;
return ReportError(protocol, error);
}
int local_socket = subprocess->ReleaseLocalSocket();
D("subprocess creation successful: local_socket_fd=%d, pid=%d", local_socket, subprocess->pid());
if (!Subprocess::StartThread(std::move(subprocess), &error)) {
LOG(ERROR) << "failed to start subprocess management thread: " << error;
return ReportError(protocol, error);
}
return local_socket;
}
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