support "sideload over ADB" mode

Rather than depending on the existence of some place to store a file
that is accessible to users on an an unbootable device (eg, a physical
sdcard, external USB drive, etc.), add support for sideloading
packages sent to the device with adb.

This change adds a "minimal adbd" which supports nothing but receiving
a package over adb (with the "adb sideload" command) and storing it to
a fixed filename in the /tmp ramdisk, from where it can be verified
and sideloaded in the usual way.  This should be leave available even
on locked user-build devices.

The user can select "apply package from ADB" from the recovery menu,
which starts minimal-adb mode (shutting down any real adbd that may be
running).  Once minimal-adb has received a package it exits
(restarting real adbd if appropriate) and then verification and
installation of the received package proceeds.

Change-Id: I6fe13161ca064a98d06fa32104e1f432826582f5

1 files changed, 110 insertions, 0 deletions

diff --git a/adb_install.cpp b/adb_install.cpp
new file mode 100644
index 0000000..a226ea5
--- /dev/null
+++ b/adb_install.cpp
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2012 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 <unistd.h>
+#include <dirent.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include "ui.h"
+#include "cutils/properties.h"
+#include "install.h"
+#include "common.h"
+#include "adb_install.h"
+extern "C" {
+#include "minadbd/adb.h"
+}
+
+static RecoveryUI* ui = NULL;
+
+static void
+set_usb_driver(bool enabled) {
+    int fd = open("/sys/class/android_usb/android0/enable", O_WRONLY);
+    if (fd < 0) {
+        ui->Print("failed to open driver control: %s\n", strerror(errno));
+        return;
+    }
+    if (write(fd, enabled ? "1" : "0", 1) < 0) {
+        ui->Print("failed to set driver control: %s\n", strerror(errno));
+    }
+    if (close(fd) < 0) {
+        ui->Print("failed to close driver control: %s\n", strerror(errno));
+    }
+}
+
+static void
+stop_adbd() {
+    property_set("ctl.stop", "adbd");
+    set_usb_driver(false);
+}
+
+
+static void
+maybe_restart_adbd() {
+    char value[PROPERTY_VALUE_MAX+1];
+    int len = property_get("ro.debuggable", value, NULL);
+    if (len == 1 && value[0] == '1') {
+        ui->Print("Restarting adbd...\n");
+        set_usb_driver(true);
+        property_set("ctl.start", "adbd");
+    }
+}
+
+int
+apply_from_adb(RecoveryUI* ui_, int* wipe_cache, const char* install_file) {
+    ui = ui_;
+
+    stop_adbd();
+    set_usb_driver(true);
+
+    ui->Print("\n\nNow send the package you want to apply\n"
+              "to the device with \"adb sideload <filename>\"...\n");
+
+    pid_t child;
+    if ((child = fork()) == 0) {
+        execl("/sbin/recovery", "recovery", "--adbd", NULL);
+        _exit(-1);
+    }
+    int status;
+    // TODO(dougz): there should be a way to cancel waiting for a
+    // package (by pushing some button combo on the device).  For now
+    // you just have to 'adb sideload' a file that's not a valid
+    // package, like "/dev/null".
+    waitpid(child, &status, 0);
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        ui->Print("status %d\n", WEXITSTATUS(status));
+    }
+
+    set_usb_driver(false);
+    maybe_restart_adbd();
+
+    struct stat st;
+    if (stat(ADB_SIDELOAD_FILENAME, &st) != 0) {
+        if (errno == ENOENT) {
+            ui->Print("No package received.\n");
+        } else {
+            ui->Print("Error reading package:\n  %s\n", strerror(errno));
+        }
+        return INSTALL_ERROR;
+    }
+    return install_package(ADB_SIDELOAD_FILENAME, wipe_cache, install_file);
+}