783 lines
28 KiB
C++
783 lines
28 KiB
C++
/*
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* Copyright (C) 2015 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// Functionality for launching and managing shell subprocesses.
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//
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// There are two types of subprocesses, PTY or raw. PTY is typically used for
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// an interactive session, raw for non-interactive. There are also two methods
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// of communication with the subprocess, passing raw data or using a simple
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// protocol to wrap packets. The protocol allows separating stdout/stderr and
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// passing the exit code back, but is not backwards compatible.
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// ----------------+--------------------------------------
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// Type Protocol | Exit code? Separate stdout/stderr?
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// ----------------+--------------------------------------
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// PTY No | No No
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// Raw No | No No
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// PTY Yes | Yes No
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// Raw Yes | Yes Yes
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// ----------------+--------------------------------------
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//
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// Non-protocol subprocesses work by passing subprocess stdin/out/err through
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// a single pipe which is registered with a local socket in adbd. The local
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// socket uses the fdevent loop to pass raw data between this pipe and the
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// transport, which then passes data back to the adb client. Cleanup is done by
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// waiting in a separate thread for the subprocesses to exit and then signaling
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// a separate fdevent to close out the local socket from the main loop.
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//
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// ------------------+-------------------------+------------------------------
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// Subprocess | adbd subprocess thread | adbd main fdevent loop
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// ------------------+-------------------------+------------------------------
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// | |
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// stdin/out/err <-----------------------------> LocalSocket
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// | | |
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// | | Block on exit |
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// | | * |
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// v | * |
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// Exit ---> Unblock |
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// | | |
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// | v |
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// | Notify shell exit FD ---> Close LocalSocket
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// ------------------+-------------------------+------------------------------
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//
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// The protocol requires the thread to intercept stdin/out/err in order to
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// wrap/unwrap data with shell protocol packets.
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//
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// ------------------+-------------------------+------------------------------
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// Subprocess | adbd subprocess thread | adbd main fdevent loop
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// ------------------+-------------------------+------------------------------
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// | |
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// stdin/out <---> Protocol <---> LocalSocket
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// stderr ---> Protocol ---> LocalSocket
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// | | |
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// v | |
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// Exit ---> Exit code protocol ---> LocalSocket
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// | | |
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// | v |
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// | Notify shell exit FD ---> Close LocalSocket
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// ------------------+-------------------------+------------------------------
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//
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// An alternate approach is to put the protocol wrapping/unwrapping in the main
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// fdevent loop, which has the advantage of being able to re-use the existing
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// select() code for handling data streams. However, implementation turned out
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// to be more complex due to partial reads and non-blocking I/O so this model
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// was chosen instead.
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#define TRACE_TAG SHELL
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#include "sysdeps.h"
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#include "shell_service.h"
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#include <errno.h>
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#include <pty.h>
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#include <pwd.h>
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#include <sys/select.h>
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#include <termios.h>
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#include <memory>
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#include <string>
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#include <unordered_map>
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#include <vector>
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#include <android-base/logging.h>
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#include <android-base/stringprintf.h>
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#include <paths.h>
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#include <log/log.h>
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#include "adb.h"
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#include "adb_io.h"
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#include "adb_trace.h"
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#include "adb_utils.h"
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#include "security_log_tags.h"
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namespace {
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void init_subproc_child()
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{
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setsid();
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// Set OOM score adjustment to prevent killing
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int fd = adb_open("/proc/self/oom_score_adj", O_WRONLY | O_CLOEXEC);
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if (fd >= 0) {
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adb_write(fd, "0", 1);
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adb_close(fd);
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} else {
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D("adb: unable to update oom_score_adj");
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}
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}
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// Reads from |fd| until close or failure.
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std::string ReadAll(int fd) {
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char buffer[512];
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std::string received;
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while (1) {
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int bytes = adb_read(fd, buffer, sizeof(buffer));
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if (bytes <= 0) {
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break;
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}
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received.append(buffer, bytes);
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}
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return received;
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}
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// Helper to automatically close an FD when it goes out of scope.
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class ScopedFd {
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public:
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ScopedFd() {}
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~ScopedFd() { Reset(); }
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void Reset(int fd=-1) {
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if (fd != fd_) {
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if (valid()) {
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adb_close(fd_);
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}
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fd_ = fd;
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}
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}
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int Release() {
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int temp = fd_;
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fd_ = -1;
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return temp;
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}
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bool valid() const { return fd_ >= 0; }
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int fd() const { return fd_; }
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private:
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int fd_ = -1;
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DISALLOW_COPY_AND_ASSIGN(ScopedFd);
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};
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// Creates a socketpair and saves the endpoints to |fd1| and |fd2|.
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bool CreateSocketpair(ScopedFd* fd1, ScopedFd* fd2) {
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int sockets[2];
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if (adb_socketpair(sockets) < 0) {
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PLOG(ERROR) << "cannot create socket pair";
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return false;
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}
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fd1->Reset(sockets[0]);
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fd2->Reset(sockets[1]);
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return true;
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}
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class Subprocess {
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public:
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Subprocess(const std::string& command, const char* terminal_type,
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SubprocessType type, SubprocessProtocol protocol);
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~Subprocess();
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const std::string& command() const { return command_; }
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int local_socket_fd() const { return local_socket_sfd_.fd(); }
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pid_t pid() const { return pid_; }
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// Sets up FDs, forks a subprocess, starts the subprocess manager thread,
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// and exec's the child. Returns false on failure.
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bool ForkAndExec(std::string* _Nonnull error);
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private:
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// Opens the file at |pts_name|.
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int OpenPtyChildFd(const char* pts_name, ScopedFd* error_sfd);
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static void* ThreadHandler(void* userdata);
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void PassDataStreams();
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void WaitForExit();
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ScopedFd* SelectLoop(fd_set* master_read_set_ptr,
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fd_set* master_write_set_ptr);
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// Input/output stream handlers. Success returns nullptr, failure returns
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// a pointer to the failed FD.
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ScopedFd* PassInput();
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ScopedFd* PassOutput(ScopedFd* sfd, ShellProtocol::Id id);
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const std::string command_;
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const std::string terminal_type_;
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bool make_pty_raw_ = false;
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SubprocessType type_;
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SubprocessProtocol protocol_;
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pid_t pid_ = -1;
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ScopedFd local_socket_sfd_;
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// Shell protocol variables.
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ScopedFd stdinout_sfd_, stderr_sfd_, protocol_sfd_;
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std::unique_ptr<ShellProtocol> input_, output_;
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size_t input_bytes_left_ = 0;
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DISALLOW_COPY_AND_ASSIGN(Subprocess);
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};
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Subprocess::Subprocess(const std::string& command, const char* terminal_type,
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SubprocessType type, SubprocessProtocol protocol)
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: command_(command),
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terminal_type_(terminal_type ? terminal_type : ""),
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type_(type),
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protocol_(protocol) {
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// If we aren't using the shell protocol we must allocate a PTY to properly close the
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// subprocess. PTYs automatically send SIGHUP to the slave-side process when the master side
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// of the PTY closes, which we rely on. If we use a raw pipe, processes that don't read/write,
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// e.g. screenrecord, will never notice the broken pipe and terminate.
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// The shell protocol doesn't require a PTY because it's always monitoring the local socket FD
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// with select() and will send SIGHUP manually to the child process.
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if (protocol_ == SubprocessProtocol::kNone && type_ == SubprocessType::kRaw) {
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// Disable PTY input/output processing since the client is expecting raw data.
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D("Can't create raw subprocess without shell protocol, using PTY in raw mode instead");
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type_ = SubprocessType::kPty;
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make_pty_raw_ = true;
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}
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}
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Subprocess::~Subprocess() {
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WaitForExit();
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}
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bool Subprocess::ForkAndExec(std::string* error) {
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ScopedFd child_stdinout_sfd, child_stderr_sfd;
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ScopedFd parent_error_sfd, child_error_sfd;
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char pts_name[PATH_MAX];
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if (command_.empty()) {
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__android_log_security_bswrite(SEC_TAG_ADB_SHELL_INTERACTIVE, "");
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} else {
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__android_log_security_bswrite(SEC_TAG_ADB_SHELL_CMD, command_.c_str());
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}
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// Create a socketpair for the fork() child to report any errors back to the parent. Since we
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// use threads, logging directly from the child might deadlock due to locks held in another
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// thread during the fork.
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if (!CreateSocketpair(&parent_error_sfd, &child_error_sfd)) {
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*error = android::base::StringPrintf(
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"failed to create pipe for subprocess error reporting: %s", strerror(errno));
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return false;
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}
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// Construct the environment for the child before we fork.
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passwd* pw = getpwuid(getuid());
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std::unordered_map<std::string, std::string> env;
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if (environ) {
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char** current = environ;
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while (char* env_cstr = *current++) {
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std::string env_string = env_cstr;
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char* delimiter = strchr(env_string.c_str(), '=');
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// Drop any values that don't contain '='.
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if (delimiter) {
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*delimiter++ = '\0';
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env[env_string.c_str()] = delimiter;
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}
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}
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}
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if (pw != nullptr) {
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// TODO: $HOSTNAME? Normally bash automatically sets that, but mksh doesn't.
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env["HOME"] = pw->pw_dir;
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env["LOGNAME"] = pw->pw_name;
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env["USER"] = pw->pw_name;
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env["SHELL"] = pw->pw_shell;
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}
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if (!terminal_type_.empty()) {
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env["TERM"] = terminal_type_;
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}
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std::vector<std::string> joined_env;
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for (auto it : env) {
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const char* key = it.first.c_str();
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const char* value = it.second.c_str();
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joined_env.push_back(android::base::StringPrintf("%s=%s", key, value));
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}
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std::vector<const char*> cenv;
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for (const std::string& str : joined_env) {
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cenv.push_back(str.c_str());
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}
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cenv.push_back(nullptr);
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if (type_ == SubprocessType::kPty) {
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int fd;
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pid_ = forkpty(&fd, pts_name, nullptr, nullptr);
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stdinout_sfd_.Reset(fd);
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} else {
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if (!CreateSocketpair(&stdinout_sfd_, &child_stdinout_sfd)) {
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*error = android::base::StringPrintf("failed to create socketpair for stdin/out: %s",
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strerror(errno));
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return false;
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}
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// Raw subprocess + shell protocol allows for splitting stderr.
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if (protocol_ == SubprocessProtocol::kShell &&
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!CreateSocketpair(&stderr_sfd_, &child_stderr_sfd)) {
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*error = android::base::StringPrintf("failed to create socketpair for stderr: %s",
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strerror(errno));
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return false;
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}
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pid_ = fork();
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}
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if (pid_ == -1) {
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*error = android::base::StringPrintf("fork failed: %s", strerror(errno));
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return false;
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}
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if (pid_ == 0) {
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// Subprocess child.
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init_subproc_child();
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if (type_ == SubprocessType::kPty) {
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child_stdinout_sfd.Reset(OpenPtyChildFd(pts_name, &child_error_sfd));
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}
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dup2(child_stdinout_sfd.fd(), STDIN_FILENO);
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dup2(child_stdinout_sfd.fd(), STDOUT_FILENO);
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dup2(child_stderr_sfd.valid() ? child_stderr_sfd.fd() : child_stdinout_sfd.fd(),
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STDERR_FILENO);
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// exec doesn't trigger destructors, close the FDs manually.
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stdinout_sfd_.Reset();
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stderr_sfd_.Reset();
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child_stdinout_sfd.Reset();
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child_stderr_sfd.Reset();
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parent_error_sfd.Reset();
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close_on_exec(child_error_sfd.fd());
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if (command_.empty()) {
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execle(_PATH_BSHELL, _PATH_BSHELL, "-", nullptr, cenv.data());
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} else {
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execle(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr, cenv.data());
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}
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WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed: ");
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WriteFdExactly(child_error_sfd.fd(), strerror(errno));
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child_error_sfd.Reset();
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_Exit(1);
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}
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// Subprocess parent.
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D("subprocess parent: stdin/stdout FD = %d, stderr FD = %d",
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stdinout_sfd_.fd(), stderr_sfd_.fd());
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// Wait to make sure the subprocess exec'd without error.
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child_error_sfd.Reset();
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std::string error_message = ReadAll(parent_error_sfd.fd());
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if (!error_message.empty()) {
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*error = error_message;
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return false;
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}
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D("subprocess parent: exec completed");
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if (protocol_ == SubprocessProtocol::kNone) {
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// No protocol: all streams pass through the stdinout FD and hook
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// directly into the local socket for raw data transfer.
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local_socket_sfd_.Reset(stdinout_sfd_.Release());
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} else {
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// Shell protocol: create another socketpair to intercept data.
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if (!CreateSocketpair(&protocol_sfd_, &local_socket_sfd_)) {
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*error = android::base::StringPrintf(
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"failed to create socketpair to intercept data: %s", strerror(errno));
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kill(pid_, SIGKILL);
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return false;
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}
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D("protocol FD = %d", protocol_sfd_.fd());
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input_.reset(new ShellProtocol(protocol_sfd_.fd()));
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output_.reset(new ShellProtocol(protocol_sfd_.fd()));
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if (!input_ || !output_) {
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*error = "failed to allocate shell protocol objects";
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kill(pid_, SIGKILL);
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return false;
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}
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// Don't let reads/writes to the subprocess block our thread. This isn't
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// likely but could happen under unusual circumstances, such as if we
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// write a ton of data to stdin but the subprocess never reads it and
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// the pipe fills up.
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for (int fd : {stdinout_sfd_.fd(), stderr_sfd_.fd()}) {
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if (fd >= 0) {
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if (!set_file_block_mode(fd, false)) {
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*error = android::base::StringPrintf(
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"failed to set non-blocking mode for fd %d", fd);
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kill(pid_, SIGKILL);
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return false;
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}
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}
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}
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}
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if (!adb_thread_create(ThreadHandler, this)) {
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*error =
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android::base::StringPrintf("failed to create subprocess thread: %s", strerror(errno));
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kill(pid_, SIGKILL);
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return false;
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}
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D("subprocess parent: completed");
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return true;
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}
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int Subprocess::OpenPtyChildFd(const char* pts_name, ScopedFd* error_sfd) {
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int child_fd = adb_open(pts_name, O_RDWR | O_CLOEXEC);
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if (child_fd == -1) {
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// Don't use WriteFdFmt; since we're in the fork() child we don't want
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// to allocate any heap memory to avoid race conditions.
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const char* messages[] = {"child failed to open pseudo-term slave ",
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pts_name, ": ", strerror(errno)};
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for (const char* message : messages) {
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WriteFdExactly(error_sfd->fd(), message);
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}
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exit(-1);
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}
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if (make_pty_raw_) {
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termios tattr;
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if (tcgetattr(child_fd, &tattr) == -1) {
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int saved_errno = errno;
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WriteFdExactly(error_sfd->fd(), "tcgetattr failed: ");
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WriteFdExactly(error_sfd->fd(), strerror(saved_errno));
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exit(-1);
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}
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cfmakeraw(&tattr);
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if (tcsetattr(child_fd, TCSADRAIN, &tattr) == -1) {
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int saved_errno = errno;
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WriteFdExactly(error_sfd->fd(), "tcsetattr failed: ");
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WriteFdExactly(error_sfd->fd(), strerror(saved_errno));
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exit(-1);
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}
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}
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return child_fd;
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}
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void* Subprocess::ThreadHandler(void* userdata) {
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Subprocess* subprocess = reinterpret_cast<Subprocess*>(userdata);
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adb_thread_setname(android::base::StringPrintf(
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"shell srvc %d", subprocess->local_socket_fd()));
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subprocess->PassDataStreams();
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D("deleting Subprocess for PID %d", subprocess->pid());
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delete subprocess;
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return nullptr;
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}
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void Subprocess::PassDataStreams() {
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if (!protocol_sfd_.valid()) {
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return;
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}
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// Start by trying to read from the protocol FD, stdout, and stderr.
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fd_set master_read_set, master_write_set;
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FD_ZERO(&master_read_set);
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FD_ZERO(&master_write_set);
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for (ScopedFd* sfd : {&protocol_sfd_, &stdinout_sfd_, &stderr_sfd_}) {
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if (sfd->valid()) {
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FD_SET(sfd->fd(), &master_read_set);
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}
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}
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// Pass data until the protocol FD or both the subprocess pipes die, at
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// which point we can't pass any more data.
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while (protocol_sfd_.valid() &&
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(stdinout_sfd_.valid() || stderr_sfd_.valid())) {
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ScopedFd* dead_sfd = SelectLoop(&master_read_set, &master_write_set);
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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);
|
|
}
|
|
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);
|
|
|
|
Subprocess* subprocess = new 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;
|
|
delete subprocess;
|
|
return ReportError(protocol, error);
|
|
}
|
|
|
|
D("subprocess creation successful: local_socket_fd=%d, pid=%d",
|
|
subprocess->local_socket_fd(), subprocess->pid());
|
|
return subprocess->local_socket_fd();
|
|
}
|