Migrate MagiskBoot to C++

native/jni/magiskboot/hexpatch.cpp

@@ -0,0 +1,38 @@
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include "magiskboot.h"
+#include "utils.h"
+
+static void hex2byte(uint8_t *hex, uint8_t *str) {
+	char high, low;
+	for (int i = 0, length = strlen((char *) hex); i < length; i += 2) {
+		high = toupper(hex[i]) - '0';
+		low = toupper(hex[i + 1]) - '0';
+		str[i / 2] = ((high > 9 ? high - 7 : high) << 4) + (low > 9 ? low - 7 : low);
+	}
+}
+
+void hexpatch(const char *image, const char *from, const char *to) {
+	int patternsize = strlen(from) / 2, patchsize = strlen(to) / 2;
+	size_t filesize;
+	uint8_t *file, *pattern, *patch;
+	mmap_rw(image, (void **) &file, &filesize);
+	pattern = (uint8_t *) xmalloc(patternsize);
+	patch = (uint8_t *) xmalloc(patchsize);
+	hex2byte((uint8_t *) from, pattern);
+	hex2byte((uint8_t *) to, patch);
+	for (size_t i = 0; filesize > 0 && i < filesize - patternsize; ++i) {
+		if (memcmp(file + i, pattern, patternsize) == 0) {
+			fprintf(stderr, "Patch @ %08X [%s]->[%s]\n", (unsigned) i, from, to);
+			memset(file + i, 0, patternsize);
+			memcpy(file + i, patch, patchsize);
+			i += patternsize - 1;
+		}
+	}
+	munmap(file, filesize);
+	free(pattern);
+	free(patch);
+}