add the functions for multi-stage packages to updater

In order to support multi-stage recovery packages, we add the
set_stage() and get_stage() functions, which store a short string
somewhere it can be accessed across invocations of recovery.  We also
add reboot_now() which updater can invoke to immediately reboot the
device, without doing normal recovery cleanup.  (It can also choose
whether to boot off the boot or recovery partition.)

If the stage string is of the form "#/#", recovery's UI will be
augmented with a simple indicator of what stage you're in, so it
doesn't look like a reboot loop.

Change-Id: I62f7ff0bc802b549c9bcf3cc154a6bad99f94603

1 files changed, 106 insertions, 1 deletions

diff --git a/updater/install.c b/updater/install.c
index 9fb1b63..9f299f6 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -34,6 +34,9 @@
 #include <linux/xattr.h>
 #include <inttypes.h>
 
+#include "bootloader.h"
+#include "applypatch/applypatch.h"
+#include "cutils/android_reboot.h"
 #include "cutils/misc.h"
 #include "cutils/properties.h"
 #include "edify/expr.h"
@@ -42,7 +45,6 @@
 #include "mtdutils/mounts.h"
 #include "mtdutils/mtdutils.h"
 #include "updater.h"
-#include "applypatch/applypatch.h"
 
 #ifdef USE_EXT4
 #include "make_ext4fs.h"
@@ -1419,6 +1421,105 @@ Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) {
     return v;
 }
 
+// Immediately reboot the device.  Recovery is not finished normally,
+// so if you reboot into recovery it will re-start applying the
+// current package (because nothing has cleared the copy of the
+// arguments stored in the BCB).
+//
+// The argument is the partition name passed to the android reboot
+// property.  It can be "recovery" to boot from the recovery
+// partition, or "" (empty string) to boot from the regular boot
+// partition.
+Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* filename;
+    char* property;
+    if (ReadArgs(state, argv, 2, &filename, &property) < 0) return NULL;
+
+    char buffer[80];
+
+    // zero out the 'command' field of the bootloader message.
+    memset(buffer, 0, sizeof(((struct bootloader_message*)0)->command));
+    FILE* f = fopen(filename, "r+b");
+    fseek(f, offsetof(struct bootloader_message, command), SEEK_SET);
+    fwrite(buffer, sizeof(((struct bootloader_message*)0)->command), 1, f);
+    fclose(f);
+    free(filename);
+
+    strcpy(buffer, "reboot,");
+    if (property != NULL) {
+        strncat(buffer, property, sizeof(buffer)-10);
+    }
+
+    property_set(ANDROID_RB_PROPERTY, buffer);
+
+    sleep(5);
+    free(property);
+    ErrorAbort(state, "%s() failed to reboot", name);
+    return NULL;
+}
+
+// Store a string value somewhere that future invocations of recovery
+// can access it.  This value is called the "stage" and can be used to
+// drive packages that need to do reboots in the middle of
+// installation and keep track of where they are in the multi-stage
+// install.
+//
+// The first argument is the block device for the misc partition
+// ("/misc" in the fstab), which is where this value is stored.  The
+// second argument is the string to store; it should not exceed 31
+// bytes.
+Value* SetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* filename;
+    char* stagestr;
+    if (ReadArgs(state, argv, 2, &filename, &stagestr) < 0) return NULL;
+
+    // Store this value in the misc partition, immediately after the
+    // bootloader message that the main recovery uses to save its
+    // arguments in case of the device restarting midway through
+    // package installation.
+    FILE* f = fopen(filename, "r+b");
+    fseek(f, offsetof(struct bootloader_message, stage), SEEK_SET);
+    int to_write = strlen(stagestr)+1;
+    int max_size = sizeof(((struct bootloader_message*)0)->stage);
+    if (to_write > max_size) {
+        to_write = max_size;
+        stagestr[max_size-1] = 0;
+    }
+    fwrite(stagestr, to_write, 1, f);
+    fclose(f);
+
+    free(stagestr);
+    return StringValue(filename);
+}
+
+// Return the value most recently saved with SetStageFn.  The argument
+// is the block device for the misc partition.
+Value* GetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+
+    char* filename;
+    if (ReadArgs(state, argv, 1, &filename) < 0) return NULL;
+
+    char buffer[sizeof(((struct bootloader_message*)0)->stage)];
+    FILE* f = fopen(filename, "rb");
+    fseek(f, offsetof(struct bootloader_message, stage), SEEK_SET);
+    fread(buffer, sizeof(buffer), 1, f);
+    fclose(f);
+    buffer[sizeof(buffer)-1] = '\0';
+
+    return StringValue(strdup(buffer));
+}
+
 void RegisterInstallFunctions() {
     RegisterFunction("mount", MountFn);
     RegisterFunction("is_mounted", IsMountedFn);
@@ -1466,4 +1567,8 @@ void RegisterInstallFunctions() {
     RegisterFunction("ui_print", UIPrintFn);
 
     RegisterFunction("run_program", RunProgramFn);
+
+    RegisterFunction("reboot_now", RebootNowFn);
+    RegisterFunction("get_stage", GetStageFn);
+    RegisterFunction("set_stage", SetStageFn);
 }