From def91c0abff84d6b51db507965cfb5f543538a80 Mon Sep 17 00:00:00 2001
From: Josh Gao <jmgao@google.com>
Date: Tue, 31 Jul 2018 18:28:32 -0700
Subject: [PATCH] adb: disable ReconnectHandler in adbd.

Previously, when a TCP connection was disconnected from adbd, we were
registering it with ReconnectHandler, which led to the transport
sticking around after the socket was closed. Due to the naming of
TCP transports in adbd (host-<fd number>), this results in incoming
connections being immediately closed if their file descriptor number
ends up being the same as a TCP transport that had previously
disconnected.

Guard all of the reconnect logic with ADB_HOST, to fix this.

Bug: http://b/112054041
Test: while true; do adb connect <device>; adb connect <device>; adb shell true; done
Change-Id: Ib55d304d7e07d6d744e8321d34671bb6d4b91afe
---
 adb/transport.cpp | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/adb/transport.cpp b/adb/transport.cpp
index b45c43f89..922200826 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -81,6 +81,7 @@ class SCOPED_CAPABILITY ScopedAssumeLocked {
     ~ScopedAssumeLocked() RELEASE() {}
 };
 
+#if ADB_HOST
 // Tracks and handles atransport*s that are attempting reconnection.
 class ReconnectHandler {
   public:
@@ -224,6 +225,8 @@ void ReconnectHandler::Run() {
 
 static auto& reconnect_handler = *new ReconnectHandler();
 
+#endif
+
 }  // namespace
 
 TransportId NextTransportId() {
@@ -697,9 +700,11 @@ static void transport_registration_func(int _fd, unsigned ev, void*) {
     update_transports();
 }
 
+#if ADB_HOST
 void init_reconnect_handler(void) {
     reconnect_handler.Start();
 }
+#endif
 
 void init_transport_registration(void) {
     int s[2];
@@ -718,7 +723,9 @@ void init_transport_registration(void) {
 }
 
 void kick_all_transports() {
+#if ADB_HOST
     reconnect_handler.Stop();
+#endif
     // To avoid only writing part of a packet to a transport after exit, kick all transports.
     std::lock_guard<std::recursive_mutex> lock(transport_lock);
     for (auto t : transport_list) {
@@ -756,13 +763,19 @@ static void transport_unref(atransport* t) {
     t->ref_count--;
     if (t->ref_count == 0) {
         t->connection()->Stop();
+#if ADB_HOST
         if (t->IsTcpDevice() && !t->kicked()) {
-            D("transport: %s unref (attempting reconnection) %d", t->serial.c_str(), t->kicked());
+            D("transport: %s unref (attempting reconnection)", t->serial.c_str());
             reconnect_handler.TrackTransport(t);
         } else {
             D("transport: %s unref (kicking and closing)", t->serial.c_str());
             remove_transport(t);
         }
+#else
+        D("transport: %s unref (kicking and closing)", t->serial.c_str());
+        remove_transport(t);
+#endif
+
     } else {
         D("transport: %s unref (count=%zu)", t->serial.c_str(), t->ref_count);
     }