Merge changes from topic 'adb_shell_prework'
* changes:
adb: create shell protocol class.
adb: refactor subprocess code.
adb: move shell service to a separate file.
diff --git a/Android.mk b/Android.mk
index c633cee..b0dcfac 100644
--- a/Android.mk
+++ b/Android.mk
@@ -131,6 +131,8 @@
LOCAL_SRC_FILES := \
$(LIBADB_TEST_SRCS) \
$(LIBADB_TEST_linux_SRCS) \
+ shell_service_protocol.cpp \
+ shell_service_protocol_test.cpp \
LOCAL_SANITIZE := $(adb_target_sanitize)
LOCAL_STATIC_LIBRARIES := libadbd
@@ -145,7 +147,12 @@
LOCAL_CFLAGS := -DADB_HOST=1 $(LIBADB_CFLAGS)
LOCAL_CFLAGS_windows := $(LIBADB_windows_CFLAGS)
LOCAL_CFLAGS_linux := $(LIBADB_linux_CFLAGS)
-LOCAL_SRC_FILES := $(LIBADB_TEST_SRCS) services.cpp
+LOCAL_SRC_FILES := \
+ $(LIBADB_TEST_SRCS) \
+ services.cpp \
+ shell_service_protocol.cpp \
+ shell_service_protocol_test.cpp \
+
LOCAL_SRC_FILES_linux := $(LIBADB_TEST_linux_SRCS)
LOCAL_SRC_FILES_darwin := $(LIBADB_TEST_darwin_SRCS)
LOCAL_SANITIZE := $(adb_host_sanitize)
@@ -201,6 +208,7 @@
adb_client.cpp \
services.cpp \
file_sync_client.cpp \
+ shell_service_protocol.cpp \
LOCAL_CFLAGS += \
$(ADB_COMMON_CFLAGS) \
@@ -248,6 +256,8 @@
framebuffer_service.cpp \
remount_service.cpp \
set_verity_enable_state_service.cpp \
+ shell_service.cpp \
+ shell_service_protocol.cpp \
LOCAL_CFLAGS := \
$(ADB_COMMON_CFLAGS) \
diff --git a/adb.cpp b/adb.cpp
index 14df8a1..a6b539f 100644
--- a/adb.cpp
+++ b/adb.cpp
@@ -176,7 +176,8 @@
{"transport", TRACE_TRANSPORT},
{"jdwp", TRACE_JDWP},
{"services", TRACE_SERVICES},
- {"auth", TRACE_AUTH}};
+ {"auth", TRACE_AUTH},
+ {"shell", TRACE_SHELL}};
std::vector<std::string> elements = android::base::Split(trace_setting, " ");
for (const auto& elem : elements) {
diff --git a/adb_trace.h b/adb_trace.h
index 67ee854..623108e 100644
--- a/adb_trace.h
+++ b/adb_trace.h
@@ -37,6 +37,7 @@
TRACE_SERVICES,
TRACE_AUTH,
TRACE_FDEVENT,
+ TRACE_SHELL
};
extern int adb_trace_mask;
diff --git a/services.cpp b/services.cpp
index ac672f0..561431c 100644
--- a/services.cpp
+++ b/services.cpp
@@ -24,11 +24,6 @@
#include <stdlib.h>
#include <string.h>
-#if !ADB_HOST
-#include <pty.h>
-#include <termios.h>
-#endif
-
#ifndef _WIN32
#include <netdb.h>
#include <netinet/in.h>
@@ -51,6 +46,7 @@
#include "adb_utils.h"
#include "file_sync_service.h"
#include "remount_service.h"
+#include "shell_service.h"
#include "transport.h"
struct stinfo {
@@ -59,11 +55,6 @@
void *cookie;
};
-enum class SubprocessType {
- kPty,
- kRaw,
-};
-
void *service_bootstrap_func(void *x)
{
stinfo* sti = reinterpret_cast<stinfo*>(x);
@@ -234,211 +225,6 @@
return s[0];
}
-#if !ADB_HOST
-
-static 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");
- }
-}
-
-#if !ADB_HOST
-static int create_subproc_pty(const char* cmd, const char* arg0,
- const char* arg1, pid_t* pid) {
- D("create_subproc_pty(cmd=%s, arg0=%s, arg1=%s)", cmd, arg0, arg1);
- char pts_name[PATH_MAX];
- int ptm;
- *pid = forkpty(&ptm, pts_name, nullptr, nullptr);
- if (*pid == -1) {
- printf("- fork failed: %s -\n", strerror(errno));
- unix_close(ptm);
- return -1;
- }
-
- if (*pid == 0) {
- init_subproc_child();
-
- int pts = unix_open(pts_name, O_RDWR | O_CLOEXEC);
- if (pts == -1) {
- fprintf(stderr, "child failed to open pseudo-term slave %s: %s\n",
- pts_name, strerror(errno));
- unix_close(ptm);
- exit(-1);
- }
-
- // arg0 is "-c" in batch mode and "-" in interactive mode.
- if (strcmp(arg0, "-c") == 0) {
- termios tattr;
- if (tcgetattr(pts, &tattr) == -1) {
- fprintf(stderr, "tcgetattr failed: %s\n", strerror(errno));
- unix_close(pts);
- unix_close(ptm);
- exit(-1);
- }
-
- cfmakeraw(&tattr);
- if (tcsetattr(pts, TCSADRAIN, &tattr) == -1) {
- fprintf(stderr, "tcsetattr failed: %s\n", strerror(errno));
- unix_close(pts);
- unix_close(ptm);
- exit(-1);
- }
- }
-
- dup2(pts, STDIN_FILENO);
- dup2(pts, STDOUT_FILENO);
- dup2(pts, STDERR_FILENO);
-
- unix_close(pts);
- unix_close(ptm);
-
- execl(cmd, cmd, arg0, arg1, nullptr);
- fprintf(stderr, "- exec '%s' failed: %s (%d) -\n",
- cmd, strerror(errno), errno);
- exit(-1);
- } else {
- return ptm;
- }
-}
-#endif // !ADB_HOST
-
-static int create_subproc_raw(const char *cmd, const char *arg0, const char *arg1, pid_t *pid)
-{
- D("create_subproc_raw(cmd=%s, arg0=%s, arg1=%s)", cmd, arg0, arg1);
-#if defined(_WIN32)
- fprintf(stderr, "error: create_subproc_raw not implemented on Win32 (%s %s %s)\n", cmd, arg0, arg1);
- return -1;
-#else
-
- // 0 is parent socket, 1 is child socket
- int sv[2];
- if (adb_socketpair(sv) < 0) {
- printf("[ cannot create socket pair - %s ]\n", strerror(errno));
- return -1;
- }
- D("socketpair: (%d,%d)", sv[0], sv[1]);
-
- *pid = fork();
- if (*pid < 0) {
- printf("- fork failed: %s -\n", strerror(errno));
- adb_close(sv[0]);
- adb_close(sv[1]);
- return -1;
- }
-
- if (*pid == 0) {
- adb_close(sv[0]);
- init_subproc_child();
-
- dup2(sv[1], STDIN_FILENO);
- dup2(sv[1], STDOUT_FILENO);
- dup2(sv[1], STDERR_FILENO);
-
- adb_close(sv[1]);
-
- execl(cmd, cmd, arg0, arg1, NULL);
- fprintf(stderr, "- exec '%s' failed: %s (%d) -\n",
- cmd, strerror(errno), errno);
- exit(-1);
- } else {
- adb_close(sv[1]);
- return sv[0];
- }
-#endif /* !defined(_WIN32) */
-}
-#endif /* !ABD_HOST */
-
-#if ADB_HOST
-#define SHELL_COMMAND "/bin/sh"
-#else
-#define SHELL_COMMAND "/system/bin/sh"
-#endif
-
-#if !ADB_HOST
-static void subproc_waiter_service(int fd, void *cookie)
-{
- pid_t pid = (pid_t) (uintptr_t) cookie;
-
- D("entered. fd=%d of pid=%d", fd, pid);
- while (true) {
- int status;
- pid_t p = waitpid(pid, &status, 0);
- if (p == pid) {
- D("fd=%d, post waitpid(pid=%d) status=%04x", fd, p, status);
- if (WIFSIGNALED(status)) {
- D("*** Killed by signal %d", WTERMSIG(status));
- break;
- } else if (!WIFEXITED(status)) {
- D("*** Didn't exit!!. status %d", status);
- break;
- } else if (WEXITSTATUS(status) >= 0) {
- D("*** Exit code %d", WEXITSTATUS(status));
- break;
- }
- }
- }
- D("shell exited fd=%d of pid=%d err=%d", fd, pid, errno);
- if (SHELL_EXIT_NOTIFY_FD >=0) {
- int res;
- res = WriteFdExactly(SHELL_EXIT_NOTIFY_FD, &fd, sizeof(fd)) ? 0 : -1;
- D("notified shell exit via fd=%d for pid=%d res=%d errno=%d",
- SHELL_EXIT_NOTIFY_FD, pid, res, errno);
- }
-}
-
-// Starts a subprocess and spawns a thread to wait for the subprocess to finish
-// and trigger the necessary cleanup.
-//
-// |name| is the command to execute in the subprocess; empty string will start
-// an interactive session.
-// |type| selects between a PTY or raw subprocess.
-//
-// Returns an open file descriptor tied to the subprocess stdin/stdout/stderr.
-static int create_subproc_thread(const char *name, SubprocessType type) {
- const char *arg0, *arg1;
- if (*name == '\0') {
- arg0 = "-";
- arg1 = nullptr;
- } else {
- arg0 = "-c";
- arg1 = name;
- }
-
- pid_t pid = -1;
- int ret_fd;
- if (type == SubprocessType::kPty) {
- ret_fd = create_subproc_pty(SHELL_COMMAND, arg0, arg1, &pid);
- } else {
- ret_fd = create_subproc_raw(SHELL_COMMAND, arg0, arg1, &pid);
- }
- D("create_subproc ret_fd=%d pid=%d", ret_fd, pid);
-
- stinfo* sti = reinterpret_cast<stinfo*>(malloc(sizeof(stinfo)));
- if(sti == 0) fatal("cannot allocate stinfo");
- sti->func = subproc_waiter_service;
- sti->cookie = (void*) (uintptr_t) pid;
- sti->fd = ret_fd;
-
- if (!adb_thread_create(service_bootstrap_func, sti)) {
- free(sti);
- adb_close(ret_fd);
- fprintf(stderr, "cannot create service thread\n");
- return -1;
- }
-
- D("service thread started, fd=%d pid=%d", ret_fd, pid);
- return ret_fd;
-}
-#endif
-
int service_to_fd(const char* name) {
int ret = -1;
@@ -483,13 +269,13 @@
const char* args = name + 6;
if (*args) {
// Non-interactive session uses a raw subprocess.
- ret = create_subproc_thread(args, SubprocessType::kRaw);
+ ret = StartSubprocess(args, SubprocessType::kRaw);
} else {
// Interactive session uses a PTY subprocess.
- ret = create_subproc_thread(args, SubprocessType::kPty);
+ ret = StartSubprocess(args, SubprocessType::kPty);
}
} else if(!strncmp(name, "exec:", 5)) {
- ret = create_subproc_thread(name + 5, SubprocessType::kRaw);
+ ret = StartSubprocess(name + 5, SubprocessType::kRaw);
} else if(!strncmp(name, "sync:", 5)) {
ret = create_service_thread(file_sync_service, NULL);
} else if(!strncmp(name, "remount:", 8)) {
@@ -503,11 +289,11 @@
} else if(!strncmp(name, "unroot:", 7)) {
ret = create_service_thread(restart_unroot_service, NULL);
} else if(!strncmp(name, "backup:", 7)) {
- ret = create_subproc_thread(android::base::StringPrintf("/system/bin/bu backup %s",
- (name + 7)).c_str(),
- SubprocessType::kRaw);
+ ret = StartSubprocess(android::base::StringPrintf("/system/bin/bu backup %s",
+ (name + 7)).c_str(),
+ SubprocessType::kRaw);
} else if(!strncmp(name, "restore:", 8)) {
- ret = create_subproc_thread("/system/bin/bu restore", SubprocessType::kRaw);
+ ret = StartSubprocess("/system/bin/bu restore", SubprocessType::kRaw);
} else if(!strncmp(name, "tcpip:", 6)) {
int port;
if (sscanf(name + 6, "%d", &port) != 1) {
diff --git a/shell_service.cpp b/shell_service.cpp
new file mode 100644
index 0000000..5f80a59
--- /dev/null
+++ b/shell_service.cpp
@@ -0,0 +1,329 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define TRACE_TAG TRACE_SHELL
+
+#include "shell_service.h"
+
+#if !ADB_HOST
+
+#include <errno.h>
+#include <pty.h>
+#include <termios.h>
+
+#include <base/logging.h>
+#include <base/stringprintf.h>
+#include <paths.h>
+
+#include "adb.h"
+#include "adb_io.h"
+#include "adb_trace.h"
+#include "sysdeps.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;
+}
+
+// Helper to automatically close an FD when it goes out of scope.
+class ScopedFd {
+ public:
+ ScopedFd() {}
+ ~ScopedFd() { Reset(); }
+
+ void Reset(int fd=-1) {
+ if (fd != fd_) {
+ if (valid()) {
+ adb_close(fd_);
+ }
+ fd_ = fd;
+ }
+ }
+
+ int Release() {
+ int temp = fd_;
+ fd_ = -1;
+ return temp;
+ }
+
+ bool valid() const { return fd_ >= 0; }
+
+ int fd() const { return fd_; }
+
+ private:
+ int fd_ = -1;
+
+ DISALLOW_COPY_AND_ASSIGN(ScopedFd);
+};
+
+// 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, SubprocessType type);
+ ~Subprocess();
+
+ const std::string& command() const { return command_; }
+ bool is_interactive() const { return command_.empty(); }
+
+ int local_socket_fd() const { return local_socket_sfd_.fd(); }
+
+ pid_t pid() const { return pid_; }
+
+ // Sets up FDs, forks a subprocess, starts the subprocess manager thread,
+ // and exec's the child. Returns false on failure.
+ bool ForkAndExec();
+
+ private:
+ // Opens the file at |pts_name|.
+ int OpenPtyChildFd(const char* pts_name, ScopedFd* error_sfd);
+
+ static void* ThreadHandler(void* userdata);
+ void WaitForExit();
+
+ const std::string command_;
+ SubprocessType type_;
+
+ pid_t pid_ = -1;
+ ScopedFd local_socket_sfd_;
+
+ DISALLOW_COPY_AND_ASSIGN(Subprocess);
+};
+
+Subprocess::Subprocess(const std::string& command, SubprocessType type)
+ : command_(command), type_(type) {
+}
+
+Subprocess::~Subprocess() {
+}
+
+bool Subprocess::ForkAndExec() {
+ ScopedFd parent_sfd, child_sfd, parent_error_sfd, child_error_sfd;
+ char pts_name[PATH_MAX];
+
+ // Create a socketpair for the fork() child to report any errors back to
+ // the parent. Since we use threads, logging directly from the child could
+ // create a race condition.
+ if (!CreateSocketpair(&parent_error_sfd, &child_error_sfd)) {
+ LOG(ERROR) << "failed to create pipe for subprocess error reporting";
+ }
+
+ if (type_ == SubprocessType::kPty) {
+ int fd;
+ pid_ = forkpty(&fd, pts_name, nullptr, nullptr);
+ parent_sfd.Reset(fd);
+ } else {
+ if (!CreateSocketpair(&parent_sfd, &child_sfd)) {
+ return false;
+ }
+ pid_ = fork();
+ }
+
+ if (pid_ == -1) {
+ PLOG(ERROR) << "fork failed";
+ return false;
+ }
+
+ if (pid_ == 0) {
+ // Subprocess child.
+ init_subproc_child();
+
+ if (type_ == SubprocessType::kPty) {
+ child_sfd.Reset(OpenPtyChildFd(pts_name, &child_error_sfd));
+ }
+
+ dup2(child_sfd.fd(), STDIN_FILENO);
+ dup2(child_sfd.fd(), STDOUT_FILENO);
+ dup2(child_sfd.fd(), STDERR_FILENO);
+
+ // exec doesn't trigger destructors, close the FDs manually.
+ parent_sfd.Reset();
+ child_sfd.Reset();
+ parent_error_sfd.Reset();
+ close_on_exec(child_error_sfd.fd());
+
+ if (is_interactive()) {
+ execl(_PATH_BSHELL, _PATH_BSHELL, "-", nullptr);
+ } else {
+ execl(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr);
+ }
+ WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed");
+ child_error_sfd.Reset();
+ exit(-1);
+ }
+
+ // Subprocess parent.
+ D("subprocess parent: subprocess FD = %d", parent_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()) {
+ LOG(ERROR) << error_message;
+ return false;
+ }
+
+ local_socket_sfd_.Reset(parent_sfd.Release());
+
+ if (!adb_thread_create(ThreadHandler, this)) {
+ PLOG(ERROR) << "failed to create subprocess thread";
+ 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 (!is_interactive()) {
+ termios tattr;
+ if (tcgetattr(child_fd, &tattr) == -1) {
+ WriteFdExactly(error_sfd->fd(), "tcgetattr failed");
+ exit(-1);
+ }
+
+ cfmakeraw(&tattr);
+ if (tcsetattr(child_fd, TCSADRAIN, &tattr) == -1) {
+ WriteFdExactly(error_sfd->fd(), "tcsetattr failed");
+ 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->local_socket_fd()));
+
+ subprocess->WaitForExit();
+
+ D("deleting Subprocess");
+ delete subprocess;
+
+ return nullptr;
+}
+
+void Subprocess::WaitForExit() {
+ 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)) {
+ D("subprocess killed by signal %d", WTERMSIG(status));
+ break;
+ } else if (!WIFEXITED(status)) {
+ D("subprocess didn't exit");
+ break;
+ } else if (WEXITSTATUS(status) >= 0) {
+ D("subprocess exit code = %d", WEXITSTATUS(status));
+ break;
+ }
+ }
+ }
+
+ // 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
+
+int StartSubprocess(const char *name, SubprocessType type) {
+ D("starting %s subprocess: '%s'",
+ type == SubprocessType::kRaw ? "raw" : "PTY", name);
+
+ Subprocess* subprocess = new Subprocess(name, type);
+ if (!subprocess) {
+ LOG(ERROR) << "failed to allocate new subprocess";
+ return -1;
+ }
+
+ if (!subprocess->ForkAndExec()) {
+ LOG(ERROR) << "failed to start subprocess";
+ delete subprocess;
+ return -1;
+ }
+
+ D("subprocess creation successful: local_socket_fd=%d, pid=%d",
+ subprocess->local_socket_fd(), subprocess->pid());
+ return subprocess->local_socket_fd();
+}
+
+#endif // !ADB_HOST
diff --git a/shell_service.h b/shell_service.h
new file mode 100644
index 0000000..81d7036
--- /dev/null
+++ b/shell_service.h
@@ -0,0 +1,135 @@
+/*
+ * 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.
+ */
+
+// This file contains classes and functionality to launch shell subprocesses
+// in adbd and communicate between those subprocesses and the adb client.
+//
+// The main features exposed here are:
+// 1. A ShellPacket class to wrap data in a simple protocol. Both adbd and
+// the adb client use this class to transmit data between them.
+// 2. Functions to launch a subprocess on the adbd side.
+
+#ifndef SHELL_SERVICE_H_
+#define SHELL_SERVICE_H_
+
+#include <stdint.h>
+
+#include <base/macros.h>
+
+#include "adb.h"
+
+// Class to send and receive shell protocol packets.
+//
+// To keep things simple and predictable, reads and writes block until an entire
+// packet is complete.
+//
+// Example: read raw data from |fd| and send it in a packet.
+// ShellProtocol* p = new ShellProtocol(protocol_fd);
+// int len = adb_read(stdout_fd, p->data(), p->data_capacity());
+// packet->WritePacket(ShellProtocol::kIdStdout, len);
+//
+// Example: read a packet and print it to |stdout|.
+// ShellProtocol* p = new ShellProtocol(protocol_fd);
+// if (p->ReadPacket() && p->id() == kIdStdout) {
+// fwrite(p->data(), 1, p->data_length(), stdout);
+// }
+class ShellProtocol {
+ public:
+ // This is an unscoped enum to make it easier to compare against raw bytes.
+ enum Id : uint8_t {
+ kIdStdin = 0,
+ kIdStdout = 1,
+ kIdStderr = 2,
+ kIdExit = 3,
+ kIdInvalid = 255, // Indicates an invalid or unknown packet.
+ };
+
+ // ShellPackets will probably be too large to allocate on the stack so they
+ // should be dynamically allocated on the heap instead.
+ //
+ // |fd| is an open file descriptor to be used to send or receive packets.
+ explicit ShellProtocol(int fd);
+ virtual ~ShellProtocol();
+
+ // Returns a pointer to the data buffer.
+ const char* data() const { return buffer_ + kHeaderSize; }
+ char* data() { return buffer_ + kHeaderSize; }
+
+ // Returns the total capacity of the data buffer.
+ size_t data_capacity() const { return buffer_end_ - data(); }
+
+ // Reads a packet from the FD.
+ //
+ // If a packet is too big to fit in the buffer then Read() will split the
+ // packet across multiple calls. For example, reading a 50-byte packet into
+ // a 20-byte buffer would read 20 bytes, 20 bytes, then 10 bytes.
+ //
+ // Returns false if the FD closed or errored.
+ bool Read();
+
+ // Returns the ID of the packet in the buffer.
+ int id() const { return buffer_[0]; }
+
+ // Returns the number of bytes that have been read into the data buffer.
+ size_t data_length() const { return data_length_; }
+
+ // Writes the packet currently in the buffer to the FD.
+ //
+ // Returns false if the FD closed or errored.
+ bool Write(Id id, size_t length);
+
+ private:
+ // Packets support 4-byte lengths.
+ typedef uint32_t length_t;
+
+ enum {
+ // It's OK if MAX_PAYLOAD doesn't match on the sending and receiving
+ // end, reading will split larger packets into multiple smaller ones.
+ kBufferSize = MAX_PAYLOAD,
+
+ // Header is 1 byte ID + 4 bytes length.
+ kHeaderSize = sizeof(Id) + sizeof(length_t)
+ };
+
+ int fd_;
+ char buffer_[kBufferSize];
+ size_t data_length_ = 0, bytes_left_ = 0;
+
+ // We need to be able to modify this value for testing purposes, but it
+ // will stay constant during actual program use.
+ char* buffer_end_ = buffer_ + sizeof(buffer_);
+
+ friend class ShellProtocolTest;
+
+ DISALLOW_COPY_AND_ASSIGN(ShellProtocol);
+};
+
+#if !ADB_HOST
+
+enum class SubprocessType {
+ kPty,
+ kRaw,
+};
+
+// Forks and starts a new shell subprocess. If |name| is empty an interactive
+// shell is started, otherwise |name| is executed non-interactively.
+//
+// Returns an open FD connected to the subprocess or -1 on failure.
+int StartSubprocess(const char* name, SubprocessType type);
+
+#endif // !ADB_HOST
+
+#endif // SHELL_SERVICE_H_
diff --git a/shell_service_protocol.cpp b/shell_service_protocol.cpp
new file mode 100644
index 0000000..623629c
--- /dev/null
+++ b/shell_service_protocol.cpp
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+#include "shell_service.h"
+
+#include <string.h>
+
+#include <algorithm>
+
+#include "adb_io.h"
+
+ShellProtocol::ShellProtocol(int fd) : fd_(fd) {
+ buffer_[0] = kIdInvalid;
+}
+
+ShellProtocol::~ShellProtocol() {
+}
+
+bool ShellProtocol::Read() {
+ // Only read a new header if we've finished the last packet.
+ if (!bytes_left_) {
+ if (!ReadFdExactly(fd_, buffer_, kHeaderSize)) {
+ return false;
+ }
+
+ length_t packet_length;
+ memcpy(&packet_length, &buffer_[1], sizeof(packet_length));
+ bytes_left_ = packet_length;
+ data_length_ = 0;
+ }
+
+ size_t read_length = std::min(bytes_left_, data_capacity());
+ if (read_length && !ReadFdExactly(fd_, data(), read_length)) {
+ return false;
+ }
+
+ bytes_left_ -= read_length;
+ data_length_ = read_length;
+
+ return true;
+}
+
+bool ShellProtocol::Write(Id id, size_t length) {
+ buffer_[0] = id;
+ length_t typed_length = length;
+ memcpy(&buffer_[1], &typed_length, sizeof(typed_length));
+
+ return WriteFdExactly(fd_, buffer_, kHeaderSize + length);
+}
diff --git a/shell_service_protocol_test.cpp b/shell_service_protocol_test.cpp
new file mode 100644
index 0000000..6c75215
--- /dev/null
+++ b/shell_service_protocol_test.cpp
@@ -0,0 +1,192 @@
+/*
+ * 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.
+ */
+
+#include "shell_service.h"
+
+#include <gtest/gtest.h>
+
+#include <signal.h>
+#include <string.h>
+
+#include "sysdeps.h"
+
+class ShellProtocolTest : public ::testing::Test {
+ public:
+ static void SetUpTestCase() {
+#if !defined(_WIN32)
+ // This is normally done in main.cpp.
+ saved_sigpipe_handler_ = signal(SIGPIPE, SIG_IGN);
+#endif
+ }
+
+ static void TearDownTestCase() {
+#if !defined(_WIN32)
+ signal(SIGPIPE, saved_sigpipe_handler_);
+#endif
+ }
+
+ // Initializes the socketpair and ShellProtocols needed for testing.
+ void SetUp() {
+ int fds[2];
+ ASSERT_EQ(0, adb_socketpair(fds));
+ read_fd_ = fds[0];
+ write_fd_ = fds[1];
+
+ write_protocol_ = new ShellProtocol(write_fd_);
+ ASSERT_TRUE(write_protocol_ != nullptr);
+
+ read_protocol_ = new ShellProtocol(read_fd_);
+ ASSERT_TRUE(read_protocol_ != nullptr);
+ }
+
+ // Cleans up FDs and ShellProtocols. If an FD is closed manually during a
+ // test, set it to -1 to prevent TearDown() trying to close it again.
+ void TearDown() {
+ for (int fd : {read_fd_, write_fd_}) {
+ if (fd >= 0) {
+ adb_close(fd);
+ }
+ }
+ for (ShellProtocol* protocol : {read_protocol_, write_protocol_}) {
+ if (protocol) {
+ delete protocol;
+ }
+ }
+ }
+
+ // Fakes the buffer size so we can test filling buffers.
+ void SetReadDataCapacity(size_t size) {
+ read_protocol_->buffer_end_ = read_protocol_->data() + size;
+ }
+
+ static sighandler_t saved_sigpipe_handler_;
+
+ int read_fd_ = -1, write_fd_ = -1;
+ ShellProtocol *read_protocol_ = nullptr, *write_protocol_ = nullptr;
+};
+
+sighandler_t ShellProtocolTest::saved_sigpipe_handler_ = nullptr;
+
+namespace {
+
+// Returns true if the packet contains the given values.
+bool PacketEquals(const ShellProtocol* protocol, ShellProtocol::Id id,
+ const void* data, size_t data_length) {
+ return (protocol->id() == id &&
+ protocol->data_length() == data_length &&
+ !memcmp(data, protocol->data(), data_length));
+}
+
+} // namespace
+
+// Tests data that can fit in a single packet.
+TEST_F(ShellProtocolTest, FullPacket) {
+ ShellProtocol::Id id = ShellProtocol::kIdStdout;
+ char data[] = "abc 123 \0\r\n";
+
+ memcpy(write_protocol_->data(), data, sizeof(data));
+ ASSERT_TRUE(write_protocol_->Write(id, sizeof(data)));
+
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, data, sizeof(data)));
+}
+
+// Tests data that has to be read multiple times due to smaller read buffer.
+TEST_F(ShellProtocolTest, ReadBufferOverflow) {
+ ShellProtocol::Id id = ShellProtocol::kIdStdin;
+
+ memcpy(write_protocol_->data(), "1234567890", 10);
+ ASSERT_TRUE(write_protocol_->Write(id, 10));
+
+ SetReadDataCapacity(4);
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, "1234", 4));
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, "5678", 4));
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, "90", 2));
+}
+
+// Tests a zero length packet.
+TEST_F(ShellProtocolTest, ZeroLengthPacket) {
+ ShellProtocol::Id id = ShellProtocol::kIdStderr;
+
+ ASSERT_TRUE(write_protocol_->Write(id, 0));
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, nullptr, 0));
+}
+
+// Tests exit code packets.
+TEST_F(ShellProtocolTest, ExitCodePacket) {
+ write_protocol_->data()[0] = 20;
+ ASSERT_TRUE(write_protocol_->Write(ShellProtocol::kIdExit, 1));
+
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_EQ(ShellProtocol::kIdExit, read_protocol_->id());
+ ASSERT_EQ(20, read_protocol_->data()[0]);
+}
+
+// Tests writing to a closed pipe.
+TEST_F(ShellProtocolTest, WriteToClosedPipeFail) {
+ adb_close(read_fd_);
+ read_fd_ = -1;
+
+ ASSERT_FALSE(write_protocol_->Write(ShellProtocol::kIdStdout, 0));
+}
+
+// Tests writing to a closed FD.
+TEST_F(ShellProtocolTest, WriteToClosedFdFail) {
+ adb_close(write_fd_);
+ write_fd_ = -1;
+
+ ASSERT_FALSE(write_protocol_->Write(ShellProtocol::kIdStdout, 0));
+}
+
+// Tests reading from a closed pipe.
+TEST_F(ShellProtocolTest, ReadFromClosedPipeFail) {
+ adb_close(write_fd_);
+ write_fd_ = -1;
+
+ ASSERT_FALSE(read_protocol_->Read());
+}
+
+// Tests reading from a closed FD.
+TEST_F(ShellProtocolTest, ReadFromClosedFdFail) {
+ adb_close(read_fd_);
+ read_fd_ = -1;
+
+ ASSERT_FALSE(read_protocol_->Read());
+}
+
+// Tests reading from a closed pipe that has a packet waiting. This checks that
+// even if the pipe closes before we can fully read its contents we will still
+// be able to access the last packets.
+TEST_F(ShellProtocolTest, ReadPacketFromClosedPipe) {
+ ShellProtocol::Id id = ShellProtocol::kIdStdout;
+ char data[] = "foo bar";
+
+ memcpy(write_protocol_->data(), data, sizeof(data));
+ ASSERT_TRUE(write_protocol_->Write(id, sizeof(data)));
+ adb_close(write_fd_);
+ write_fd_ = -1;
+
+ // First read should grab the packet.
+ ASSERT_TRUE(read_protocol_->Read());
+ ASSERT_TRUE(PacketEquals(read_protocol_, id, data, sizeof(data)));
+
+ // Second read should fail.
+ ASSERT_FALSE(read_protocol_->Read());
+}