Cherry-picked from c13daef7b on master. Do not merge.
Use QEMU pipe for ADB communication when running in emulator.
Change-Id: I7934b6272c2a9825d244ce76ff65dbce6e54ebff
diff --git a/adb/transport_local.c b/adb/transport_local.c
index 4431ba7..8bea70c 100644
--- a/adb/transport_local.c
+++ b/adb/transport_local.c
@@ -185,6 +185,114 @@
return 0;
}
+/*
+ * Redefine open and write for qemu_pipe.h that contains inlined references
+ * to those routines. We will redifine them back after qemu_pipe.h inclusion.
+ */
+#undef open
+#undef write
+#define open adb_open
+#define write adb_write
+#include <hardware/qemu_pipe.h>
+#undef open
+#undef write
+#define open ___xxx_open
+#define write ___xxx_write
+
+/* A worker thread that monitors host connections, and registers a transport for
+ * every new host connection. This thread replaces server_socket_thread on
+ * condition that adbd daemon runs inside the emulator, and emulator uses QEMUD
+ * pipe to communicate with adbd daemon inside the guest. This is done in order
+ * to provide more robust communication channel between ADB host and guest. The
+ * main issue with server_socket_thread approach is that it runs on top of TCP,
+ * and thus is sensitive to network disruptions. For instance, the
+ * ConnectionManager may decide to reset all network connections, in which case
+ * the connection between ADB host and guest will be lost. To make ADB traffic
+ * independent from the network, we use here 'adb' QEMUD service to transfer data
+ * between the host, and the guest. See external/qemu/android/adb-*.* that
+ * implements the emulator's side of the protocol. Another advantage of using
+ * QEMUD approach is that ADB will be up much sooner, since it doesn't depend
+ * anymore on network being set up.
+ * The guest side of the protocol contains the following phases:
+ * - Connect with adb QEMUD service. In this phase a handle to 'adb' QEMUD service
+ * is opened, and it becomes clear whether or not emulator supports that
+ * protocol.
+ * - Wait for the ADB host to create connection with the guest. This is done by
+ * sending an 'accept' request to the adb QEMUD service, and waiting on
+ * response.
+ * - When new ADB host connection is accepted, the connection with adb QEMUD
+ * service is registered as the transport, and a 'start' request is sent to the
+ * adb QEMUD service, indicating that the guest is ready to receive messages.
+ * Note that the guest will ignore messages sent down from the emulator before
+ * the transport registration is completed. That's why we need to send the
+ * 'start' request after the transport is registered.
+ */
+static void *qemu_socket_thread(void * arg)
+{
+/* 'accept' request to the adb QEMUD service. */
+static const char _accept_req[] = "accept";
+/* 'start' request to the adb QEMUD service. */
+static const char _start_req[] = "start";
+/* 'ok' reply from the adb QEMUD service. */
+static const char _ok_resp[] = "ok";
+
+ const int port = (int)arg;
+ int res, fd;
+ char tmp[256];
+ char con_name[32];
+
+ D("transport: qemu_socket_thread() starting\n");
+
+ /* adb QEMUD service connection request. */
+ snprintf(con_name, sizeof(con_name), "qemud:adb:%d", port);
+
+ /* Connect to the adb QEMUD service. */
+ fd = qemu_pipe_open(con_name);
+ if (fd < 0) {
+ /* This could be an older version of the emulator, that doesn't
+ * implement adb QEMUD service. Fall back to the old TCP way. */
+ adb_thread_t thr;
+ D("adb service is not available. Falling back to TCP socket.\n");
+ adb_thread_create(&thr, server_socket_thread, arg);
+ return 0;
+ }
+
+ for(;;) {
+ /*
+ * Wait till the host creates a new connection.
+ */
+
+ /* Send the 'accept' request. */
+ res = adb_write(fd, _accept_req, strlen(_accept_req));
+ if (res == strlen(_accept_req)) {
+ /* Wait for the response. In the response we expect 'ok' on success,
+ * or 'ko' on failure. */
+ res = adb_read(fd, tmp, sizeof(tmp));
+ if (res != 2 || memcmp(tmp, _ok_resp, 2)) {
+ D("Accepting ADB host connection has failed.\n");
+ adb_close(fd);
+ } else {
+ /* Host is connected. Register the transport, and start the
+ * exchange. */
+ register_socket_transport(fd, "host", port, 1);
+ adb_write(fd, _start_req, strlen(_start_req));
+ }
+
+ /* Prepare for accepting of the next ADB host connection. */
+ fd = qemu_pipe_open(con_name);
+ if (fd < 0) {
+ D("adb service become unavailable.\n");
+ return 0;
+ }
+ } else {
+ D("Unable to send the '%s' request to ADB service.\n", _accept_req);
+ return 0;
+ }
+ }
+ D("transport: qemu_socket_thread() exiting\n");
+ return 0;
+}
+
void local_init(int port)
{
adb_thread_t thr;
@@ -193,7 +301,17 @@
if(HOST) {
func = client_socket_thread;
} else {
- func = server_socket_thread;
+ /* For the adbd daemon in the system image we need to distinguish
+ * between the device, and the emulator. */
+ char is_qemu[PROPERTY_VALUE_MAX];
+ property_get("ro.kernel.qemu", is_qemu, "");
+ if (!strcmp(is_qemu, "1")) {
+ /* Running inside the emulator: use QEMUD pipe as the transport. */
+ func = qemu_socket_thread;
+ } else {
+ /* Running inside the device: use TCP socket as the transport. */
+ func = server_socket_thread;
+ }
}
D("transport: local %s init\n", HOST ? "client" : "server");