Merge "adb: use TCP keepalive."

am: e663c163ac

* commit 'e663c163ac5f1931c2f9ebb091bf09a8a588432b':
  adb: use TCP keepalive.

adb/Android.mk

@@ -79,10 +79,12 @@ LIBADB_windows_CFLAGS := \
 
 LIBADB_darwin_SRC_FILES := \
     get_my_path_darwin.cpp \
+    sysdeps_unix.cpp \
     usb_osx.cpp \
 
 LIBADB_linux_SRC_FILES := \
     get_my_path_linux.cpp \
+    sysdeps_unix.cpp \
     usb_linux.cpp \
 
 LIBADB_windows_SRC_FILES := \

adb/services.cpp

@@ -421,6 +421,11 @@ static void connect_device(const std::string& address, std::string* response) {
     close_on_exec(fd);
     disable_tcp_nagle(fd);
 
+    // Send a TCP keepalive ping to the device every second so we can detect disconnects.
+    if (!set_tcp_keepalive(fd, 1)) {
+        D("warning: failed to configure TCP keepalives (%s)", strerror(errno));
+    }
+
     int ret = register_socket_transport(fd, serial.c_str(), port, 0);
     if (ret < 0) {
         adb_close(fd);

adb/sysdeps.h

@@ -841,4 +841,9 @@ static inline void disable_tcp_nagle(int fd) {
     adb_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &off, sizeof(off));
 }
 
+// Sets TCP socket |fd| to send a keepalive TCP message every |interval_sec| seconds. Set
+// |interval_sec| to 0 to disable keepalives. If keepalives are enabled, the connection will be
+// configured to drop after 10 missed keepalives. Returns true on success.
+bool set_tcp_keepalive(int fd, int interval_sec);
+
 #endif /* _ADB_SYSDEPS_H */

adb/sysdeps_unix.cpp

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2016 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 "sysdeps.h"
+
+bool set_tcp_keepalive(int fd, int interval_sec) {
+    int enable = (interval_sec > 0);
+    if (adb_setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &enable, sizeof(enable))) {
+        return false;
+    }
+
+    if (!enable) {
+        return true;
+    }
+
+    // Idle time before sending the first keepalive is TCP_KEEPIDLE on Linux, TCP_KEEPALIVE on Mac.
+#if defined(TCP_KEEPIDLE)
+    if (adb_setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &interval_sec, sizeof(interval_sec))) {
+        return false;
+    }
+#elif defined(TCP_KEEPALIVE)
+    if (adb_setsockopt(fd, IPPROTO_TCP, TCP_KEEPALIVE, &interval_sec, sizeof(interval_sec))) {
+        return false;
+    }
+#endif
+
+    // TCP_KEEPINTVL and TCP_KEEPCNT are available on Linux 2.4+ and OS X 10.8+ (Mountain Lion).
+#if defined(TCP_KEEPINTVL)
+    if (adb_setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &interval_sec, sizeof(interval_sec))) {
+        return false;
+    }
+#endif
+
+#if defined(TCP_KEEPCNT)
+    // On Windows this value is hardcoded to 10. This is a reasonable value, so we do the same here
+    // to match behavior. See SO_KEEPALIVE documentation at
+    // https://msdn.microsoft.com/en-us/library/windows/desktop/ee470551(v=vs.85).aspx.
+    const int keepcnt = 10;
+    if (adb_setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &keepcnt, sizeof(keepcnt))) {
+        return false;
+    }
+#endif
+
+    return true;
+}

adb/sysdeps_win32.cpp

@@ -1228,6 +1228,33 @@ bool set_file_block_mode(int fd, bool block) {
     }
 }
 
+bool set_tcp_keepalive(int fd, int interval_sec) {
+    FH fh = _fh_from_int(fd, __func__);
+
+    if (!fh || fh->clazz != &_fh_socket_class) {
+        D("set_tcp_keepalive(%d) failed: invalid fd", fd);
+        errno = EBADF;
+        return false;
+    }
+
+    tcp_keepalive keepalive;
+    keepalive.onoff = (interval_sec > 0);
+    keepalive.keepalivetime = interval_sec * 1000;
+    keepalive.keepaliveinterval = interval_sec * 1000;
+
+    DWORD bytes_returned = 0;
+    if (WSAIoctl(fh->fh_socket, SIO_KEEPALIVE_VALS, &keepalive, sizeof(keepalive), nullptr, 0,
+                 &bytes_returned, nullptr, nullptr) != 0) {
+        const DWORD err = WSAGetLastError();
+        D("set_tcp_keepalive(%d) failed: %s", fd,
+          android::base::SystemErrorCodeToString(err).c_str());
+        _socket_set_errno(err);
+        return false;
+    }
+
+    return true;
+}
+
 static adb_mutex_t g_console_output_buffer_lock;
 
 void