change_os_version: scan os_patch_level on boot/recovery images

Signed-off-by: Denis Efremov <[email protected]>

CMakeLists.txt

@@ -0,0 +1,73 @@
+cmake_minimum_required(VERSION 3.12)
+
+if (NOT DEFINED NDK_ROOT)
+    if (DEFINED ENV{NDK_ROOT})
+        set(NDK_ROOT "$ENV{NDK_ROOT}")
+    else ()
+        message(FATAL_ERROR "Please define NDK_ROOT to point to your NDK path!")
+    endif ()
+endif ()
+
+find_program(ZIP NAMES zip)
+
+# Set the tool chain file
+set(CMAKE_TOOLCHAIN_FILE ${NDK_ROOT}/build/cmake/android.toolchain.cmake)
+set(ANDROID_ABI arm64-v8a)
+set(ANDROID_PLATFORM latest)
+set(ANDROID_STL none)
+set(ANDROID_LD lld)
+
+add_compile_options(-Wall -Wextra -pedantic -Werror)
+
+set(DEFAULT_FUTURE_DATE "2099-12" CACHE STRING "Select os_patch_level date.")
+option(SELF_PACK_EXECUTABLES "Self-pack executables." ON)
+
+set(UPDATE_ZIP "backtothefuture-${DEFAULT_FUTURE_DATE}.zip")
+
+project(BackToTheFuture)
+
+set(CMAKE_C_FLAGS_RELEASE "-O2 -flto")
+set(ANDROID_PIE FALSE)
+link_libraries("-static")
+
+add_executable(change_os_version change_os_version.c)
+
+if (CMAKE_BUILD_TYPE STREQUAL Release)
+    add_custom_command(
+        TARGET change_os_version
+        POST_BUILD
+        COMMAND "${ANDROID_TOOLCHAIN_PREFIX}strip" --strip-all change_os_version
+        COMMENT "Stripping the executables"
+        VERBATIM
+    )
+    if (SELF_PACK_EXECUTABLES)
+      include("${CMAKE_ROOT}/Modules/FindSelfPackers.cmake")
+      if (SELF_PACKER_FOR_EXECUTABLE)
+          add_custom_command(
+              TARGET change_os_version
+              POST_BUILD
+              COMMAND ${SELF_PACKER_FOR_EXECUTABLE} -9q ${SELF_PACKER_FOR_EXECUTABLE_FLAGS} change_os_version
+              COMMENT "Packing the executables"
+              VERBATIM
+          )
+      endif ()
+    endif ()
+endif ()
+
+if (NOT CMAKE_CURRENT_BINARY_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    add_custom_command(
+        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/META-INF/com/google/android/update-binary
+        COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/META-INF/com/google/android/update-binary
+                                         ${CMAKE_CURRENT_BINARY_DIR}/META-INF/com/google/android/update-binary
+        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/META-INF/com/google/android/update-binary
+    )
+endif ()
+
+add_custom_target(zip
+    DEPENDS change_os_version
+    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/META-INF/com/google/android/update-binary
+    COMMAND ${ZIP} ${UPDATE_ZIP} change_os_version META-INF/com/google/android/update-binary
+    COMMENT "Preparing ${UPDATE_ZIP}"
+    VERBATIM
+)
+

META-INF/com/google/android/update-binary

@@ -0,0 +1,91 @@
+#!/sbin/sh
+
+ZIPFILE=$3
+ZIPNAME=${ZIPFILE##*/}
+OUTFD=$2
+
+scr_wdth=50
+
+# Detect real $OUTFD
+#
+if readlink /proc/$$/fd/$OUTFD 2>/dev/null | grep /tmp >/dev/null; then
+  OUTFD=0
+  for FD in $( ls /proc/$$/fd ); do
+    if readlink /proc/$$/fd/$FD 2>/dev/null | grep pipe >/dev/null; then
+      if ps | grep " 3 $FD " | grep -v grep >/dev/null; then
+	OUTFD=$FD
+	break
+      fi
+    fi
+  done
+fi
+
+ui_print() {
+  echo -ne "ui_print $1\n" >> /proc/self/fd/$OUTFD
+  echo -ne "ui_print\n" >> /proc/self/fd/$OUTFD
+}
+
+print_full_bar() {
+  ui_print "$(printf '%*s\n' $scr_wdth | tr ' ' '=')"
+}
+
+print_justified() {
+  local str="$1"
+  local str_len=${#str}
+  local padding_len=$(( ($scr_wdth - $str_len - 2) / 2))
+  local ljust="$(printf '%*s' $padding_len)"
+  local rjust="$(printf '%*s' $(($padding_len + $str_len % 2)))"
+
+  ui_print "=$ljust$str$rjust="
+}
+
+
+ui_print " "
+print_full_bar
+print_justified "Back to the Future"
+print_justified "OS Patch level changer v1.0"
+print_justified "of boot and recovery partitions"
+print_justified "for Samsung S10/Note10 devices."
+print_justified "https://github.com/CruelKernel/"
+print_full_bar
+ui_print " "
+
+bl=$(getprop ro.boot.bootloader)
+
+# Device is first 5 characters of bootloader string.
+#
+device=${bl:0:$((${#bl} - 8))}
+
+if echo $device | grep -Ev 'G97([035][FN0]|7[BN])|N97([05][FN0]|6[BN0]|1N)' >/dev/null; then
+  ui_print " - Unsupported device detected. Installation aborted."
+  ui_print " "
+  exit 1
+fi
+
+date="$(echo $ZIPNAME | sed 's/^.*-\(2[0-9]\{3\}-[01][0-9]\).zip$/\1/')"
+
+if [ "$date" = "$ZIPNAME" ]; then
+	date="2127-12"
+	ui_print " - Can't determine os_patch_level date"
+	ui_print " - from filename '$ZIPNAME'."
+	ui_print " - Max possible date $date will be used."
+else
+	ui_print " - Detected date from zip filename: $date."
+fi
+
+unzip -d /tmp -o $ZIPFILE change_os_version
+chmod +x /tmp/change_os_version
+
+ui_print " - Patching boot ..."
+/tmp/change_os_version /dev/block/by-name/boot same $date 2>&1 |
+	sed 's/^\(.*\)$/ui_print  - - \1\n/' >> /proc/self/fd/$OUTFD
+ui_print " "
+ui_print " - Patching recovery ..."
+/tmp/change_os_version /dev/block/by-name/recovery same $date 2>&1 |
+	sed 's/^\(.*\)$/ui_print  - - \1\n/' >> /proc/self/fd/$OUTFD
+
+rm -f /tmp/change_os_version
+
+ui_print " "
+ui_print " - Finished."
+ui_print " "

change_os_version.c

@@ -0,0 +1,155 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#define BOOT_IMAGE_HEADER_V1_SIZE 1648
+#define BOOT_IMAGE_HEADER_V2_SIZE 1660
+
+typedef union __attribute__((packed)) {
+	uint32_t version;
+	struct {
+		unsigned os_patch_level:11;
+		unsigned os_version:21;
+	};
+	struct {
+		unsigned month:4;
+		unsigned year:7;
+		unsigned c:7;
+		unsigned b:7;
+		unsigned a:7;
+	};
+} os_version_t;
+
+
+static inline void check(bool cond, const char *message, ...)
+{
+	if (cond) {
+		va_list args;
+		va_start(args, message);
+		vfprintf(stderr, message, args);
+		va_end(args);
+		exit(EXIT_FAILURE);
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	int fd;
+	uint32_t *addr;
+	const char *file, *os_version, *os_patch_level;
+	char *delim = NULL;
+	int year, month;
+	int a, b, c;
+	os_version_t curv, newv;
+	bool preserve_os_version = false;
+	bool preserve_os_patch_level = false;
+
+	check(argc != 4, "Usage: %s <file> <os_version|same> <os_patch_level|same>\n", argv[0]);
+	file = argv[1];
+	os_version = argv[2];
+	os_patch_level = argv[3];
+
+	if (!strcmp(os_version, "same")) {
+		preserve_os_version = true;
+	} else {
+		// Format: a.b.c
+		for (const char *p = os_version; *p != '\0'; ++p) {
+			check(!(isdigit(*p) || *p == '.'),
+				"Incorrect os_version '%s'. Format: a.b.c\n", os_version);
+		}
+		a = strtol(os_version, &delim, 10);
+		check(*delim != '.', "Incorrect os_version '%s'. Format: a.b.c\n", os_version);
+		b = strtol(delim + 1, &delim, 10);
+		check(*delim != '.', "Incorrect os_version '%s'. Format: a.b.c\n", os_version);
+		c = strtol(delim + 1, NULL, 10);
+		check(!(0 <= a && a <= 127 &&
+			0 <= b && b <= 127 &&
+			0 <= c && c <= 127),
+			"Incorrect os_version '%s'. Format: a.b.c\n", os_version);
+	}
+
+
+	if (!strcmp(os_patch_level, "same")) {
+		preserve_os_patch_level = true;
+	} else {
+		// Format: YYYY-MM
+		check(strlen(os_patch_level) != 7 ||
+		      os_patch_level[4] != '-'    ||
+		      !isdigit(os_patch_level[0]) ||
+		      !isdigit(os_patch_level[1]) ||
+		      !isdigit(os_patch_level[2]) ||
+		      !isdigit(os_patch_level[3]) ||
+		      !isdigit(os_patch_level[5]) ||
+		      !isdigit(os_patch_level[6]),
+			"Incorrent os_patch_level '%s'. Format: YYYY-MM\n", os_patch_level);
+
+		year  = atoi(os_patch_level);
+		month = atoi(os_patch_level + 5);
+
+		check(!(2000 <= year && year <= 2127),
+			"Incorrect year: %ld (2000 <= year <= 2127)\n", year);
+		check(!(1 <= month && month <= 12),
+			"Incorrect month: %ld (01 <= month <= 12)\n", month);
+	}
+
+	fd = open(file, O_RDWR);
+	check(fd < 0, "open %s failed: %s\n", file, strerror(errno));
+
+	addr = mmap(NULL, BOOT_IMAGE_HEADER_V1_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+	check(addr == MAP_FAILED, "mmap %s failed: %s\n", file, strerror(errno));
+
+	check(strncmp((const char *)addr, "ANDROID!", 8),
+		"Incorrect magic number, not a boot file.\n");
+
+	curv.version = *(addr + 11);
+	printf("Current OS version:\t%u.%u.%u %u-%02u\n",
+		curv.a, curv.b, curv.c,
+		curv.year + 2000, curv.month);
+
+	if (preserve_os_version) {
+		newv.os_version = curv.os_version;
+	} else {
+		newv.a = a;
+		newv.b = b;
+		newv.c = c;
+	}
+
+	if (preserve_os_patch_level) {
+		newv.os_patch_level = curv.os_patch_level;
+	} else {
+		newv.year  = (year - 2000);
+		newv.month = month;
+	}
+
+	if (curv.version != newv.version) {
+		printf("New OS version:\t\t%u.%u.%u %u-%02u\n",
+			newv.a, newv.b, newv.c,
+			newv.year + 2000, newv.month);
+
+		if (curv.os_version > newv.os_version) {
+			fprintf(stderr, "warn: new os_version is lower than current\n");
+		}
+
+		if (curv.os_patch_level > newv.os_patch_level) {
+			fprintf(stderr, "warn: new os_patch_level version is lower than current\n");
+		}
+
+		*(addr + 11) = newv.version;
+		check(msync(addr, BOOT_IMAGE_HEADER_V1_SIZE, MS_SYNC) < 0, "msync failed: %s\n", strerror(errno));
+	} else {
+		printf("The dates are the same. Nothing to be done.\n");
+	}
+
+	check(munmap(addr, BOOT_IMAGE_HEADER_V1_SIZE) < 0, "munmap failed: %s\n", strerror(errno));
+	check(close(fd) < 0, "close failed: %s\n", strerror(errno));
+
+	return 0;
+}