platform_system_core/adb/adb_client.cpp
Spencer Low 351ecd15b2 adb: fix adb client running out of sockets on Windows
Background
==========

On Windows, if you run "adb shell exit" in a loop in two windows,
eventually the adb client will be unable to connect to the adb server. I
think connect() is returning WSAEADDRINUSE: "Only one usage of each
socket address (protocol/network address/port) is normally permitted.
(10048)". The Windows System Event Log may also show Event 4227, Tcpip.
Netstat output is filled with:

  # for the adb server
  TCP    127.0.0.1:5037         127.0.0.1:65523        TIME_WAIT
  # for the adb client
  TCP    127.0.0.1:65523        127.0.0.1:5037         TIME_WAIT

The error probably means that the client is running out of free
address:port pairs.

The first netstat line is unavoidable, but the second line exists
because the adb client is not waiting for orderly/graceful shutdown of
the socket, and that is apparently required on Windows to get rid of the
second line. For more info, see
https://github.com/CompareAndSwap/SocketCloseTest .

This is exacerbated by the fact that "adb shell exit" makes 4 socket
connections to the adb server: 1) host:version, 2) host:features, 3)
host:version (again), 4) shell:exit. Also exacerbating is the fact that
the adb protocol is length-prefixed so the client typically does not
have to 'read() until zero' which effectively waits for orderly/graceful
shutdown.

The Fix
=======

Introduce a function, ReadOrderlyShutdown(), that should be called in
the adb client to wait for the server to close its socket, before
closing the client socket.

I reviewed all code where the adb client makes a connection to the adb
server and added ReadOrderlyShutdown() when it made sense. I wasn't able
to add it to the following:

* interactive_shell: this doesn't matter because this is interactive and
  thus can't be run fast enough to use up ports.
* adb sideload: I couldn't get enough test coverage and I don't think
  this is being called frequently enough to be a problem.
* send_shell_command, backup, adb_connect_command, adb shell, adb
  exec-out, install_multiple_app, adb_send_emulator_command: These
  already wait for server socket shutdown since they already call
  recv() until zero.
* restore, adb exec-in: protocol design can't have the server close
  first.
* adb start-server: no fd is actually returned
* create_local_service_socket, local_connect_arbitrary_ports,
  connect_device: probably called rarely enough not to be a problem.

Also in this change
===================

* Clarify comments in when adb_shutdown() is called before exit().
* add some missing adb_close() in adb sideload.
* Fixup error handling and comments in adb_send_emulator_command().
* Make SyncConnection::SendQuit return a success boolean.
* Add unittest for adb emu kill command. This gets code coverage over
  this very careful piece of code.

Change-Id: Iad0b1336f5b74186af2cd35f7ea827d0fa77a17c
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
2015-10-30 16:23:10 -07:00

297 lines
8.6 KiB
C++

/*
* 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 ADB
#include "sysdeps.h"
#include "adb_client.h"
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string>
#include <vector>
#include <base/stringprintf.h>
#include <base/strings.h>
#include <cutils/sockets.h>
#include "adb_io.h"
#include "adb_utils.h"
static TransportType __adb_transport = kTransportAny;
static const char* __adb_serial = NULL;
static int __adb_server_port = DEFAULT_ADB_PORT;
static const char* __adb_server_name = NULL;
void adb_set_transport(TransportType type, const char* serial)
{
__adb_transport = type;
__adb_serial = serial;
}
void adb_set_tcp_specifics(int server_port)
{
__adb_server_port = server_port;
}
void adb_set_tcp_name(const char* hostname)
{
__adb_server_name = hostname;
}
static int switch_socket_transport(int fd, std::string* error) {
std::string service;
if (__adb_serial) {
service += "host:transport:";
service += __adb_serial;
} else {
const char* transport_type = "???";
switch (__adb_transport) {
case kTransportUsb:
transport_type = "transport-usb";
break;
case kTransportLocal:
transport_type = "transport-local";
break;
case kTransportAny:
transport_type = "transport-any";
break;
case kTransportHost:
// no switch necessary
return 0;
}
service += "host:";
service += transport_type;
}
if (!SendProtocolString(fd, service)) {
*error = perror_str("write failure during connection");
adb_close(fd);
return -1;
}
D("Switch transport in progress");
if (!adb_status(fd, error)) {
adb_close(fd);
D("Switch transport failed: %s", error->c_str());
return -1;
}
D("Switch transport success");
return 0;
}
bool adb_status(int fd, std::string* error) {
char buf[5];
if (!ReadFdExactly(fd, buf, 4)) {
*error = perror_str("protocol fault (couldn't read status)");
return false;
}
if (!memcmp(buf, "OKAY", 4)) {
return true;
}
if (memcmp(buf, "FAIL", 4)) {
*error = android::base::StringPrintf("protocol fault (status %02x %02x %02x %02x?!)",
buf[0], buf[1], buf[2], buf[3]);
return false;
}
ReadProtocolString(fd, error, error);
return false;
}
int _adb_connect(const std::string& service, std::string* error) {
D("_adb_connect: %s", service.c_str());
if (service.empty() || service.size() > 1024) {
*error = android::base::StringPrintf("bad service name length (%zd)",
service.size());
return -1;
}
int fd;
std::string reason;
if (__adb_server_name) {
fd = network_connect(__adb_server_name, __adb_server_port, SOCK_STREAM, 0, &reason);
if (fd == -1) {
*error = android::base::StringPrintf("can't connect to %s:%d: %s",
__adb_server_name, __adb_server_port,
reason.c_str());
return -2;
}
} else {
fd = network_loopback_client(__adb_server_port, SOCK_STREAM, &reason);
if (fd == -1) {
*error = android::base::StringPrintf("cannot connect to daemon: %s",
reason.c_str());
return -2;
}
}
if (memcmp(&service[0],"host",4) != 0 && switch_socket_transport(fd, error)) {
return -1;
}
if (!SendProtocolString(fd, service)) {
*error = perror_str("write failure during connection");
adb_close(fd);
return -1;
}
if (!adb_status(fd, error)) {
adb_close(fd);
return -1;
}
D("_adb_connect: return fd %d", fd);
return fd;
}
int adb_connect(const std::string& service, std::string* error) {
// first query the adb server's version
int fd = _adb_connect("host:version", error);
D("adb_connect: service %s", service.c_str());
if (fd == -2 && __adb_server_name) {
fprintf(stderr,"** Cannot start server on remote host\n");
// error is the original network connection error
return fd;
} else if (fd == -2) {
fprintf(stdout,"* daemon not running. starting it now on port %d *\n",
__adb_server_port);
start_server:
if (launch_server(__adb_server_port)) {
fprintf(stderr,"* failed to start daemon *\n");
// launch_server() has already printed detailed error info, so just
// return a generic error string about the overall adb_connect()
// that the caller requested.
*error = "cannot connect to daemon";
return -1;
} else {
fprintf(stdout,"* daemon started successfully *\n");
}
/* give the server some time to start properly and detect devices */
adb_sleep_ms(3000);
// fall through to _adb_connect
} else {
// If a server is already running, check its version matches.
int version = ADB_SERVER_VERSION - 1;
// If we have a file descriptor, then parse version result.
if (fd >= 0) {
std::string version_string;
if (!ReadProtocolString(fd, &version_string, error)) {
adb_close(fd);
return -1;
}
ReadOrderlyShutdown(fd);
adb_close(fd);
if (sscanf(&version_string[0], "%04x", &version) != 1) {
*error = android::base::StringPrintf("cannot parse version string: %s",
version_string.c_str());
return -1;
}
} else {
// If fd is -1 check for "unknown host service" which would
// indicate a version of adb that does not support the
// version command, in which case we should fall-through to kill it.
if (*error != "unknown host service") {
return fd;
}
}
if (version != ADB_SERVER_VERSION) {
printf("adb server version (%d) doesn't match this client (%d); killing...\n",
version, ADB_SERVER_VERSION);
fd = _adb_connect("host:kill", error);
if (fd >= 0) {
ReadOrderlyShutdown(fd);
adb_close(fd);
} else {
// If we couldn't connect to the server or had some other error,
// report it, but still try to start the server.
fprintf(stderr, "error: %s\n", error->c_str());
}
/* XXX can we better detect its death? */
adb_sleep_ms(2000);
goto start_server;
}
}
// if the command is start-server, we are done.
if (service == "host:start-server") {
return 0;
}
fd = _adb_connect(service, error);
if (fd == -1) {
D("_adb_connect error: %s", error->c_str());
} else if(fd == -2) {
fprintf(stderr,"** daemon still not running\n");
}
D("adb_connect: return fd %d", fd);
return fd;
}
bool adb_command(const std::string& service) {
std::string error;
int fd = adb_connect(service, &error);
if (fd < 0) {
fprintf(stderr, "error: %s\n", error.c_str());
return false;
}
if (!adb_status(fd, &error)) {
fprintf(stderr, "error: %s\n", error.c_str());
adb_close(fd);
return false;
}
ReadOrderlyShutdown(fd);
adb_close(fd);
return true;
}
bool adb_query(const std::string& service, std::string* result, std::string* error) {
D("adb_query: %s", service.c_str());
int fd = adb_connect(service, error);
if (fd < 0) {
return false;
}
result->clear();
if (!ReadProtocolString(fd, result, error)) {
adb_close(fd);
return false;
}
ReadOrderlyShutdown(fd);
adb_close(fd);
return true;
}