mirror of
https://github.com/topjohnwu/Magisk.git
synced 2024-11-28 12:35:26 +00:00
39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
#include <stdlib.h>
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#include <ctype.h>
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#include <string.h>
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#include <sys/mman.h>
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#include "magiskboot.h"
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#include "utils.h"
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static void hex2byte(const char *hex, unsigned char *str) {
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char high, low;
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for (int i = 0, length = strlen(hex); i < length; i += 2) {
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high = toupper(hex[i]) - '0';
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low = toupper(hex[i + 1]) - '0';
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str[i / 2] = ((high > 9 ? high - 7 : high) << 4) + (low > 9 ? low - 7 : low);
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}
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}
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void hexpatch(const char *image, const char *from, const char *to) {
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int patternsize = strlen(from) / 2, patchsize = strlen(to) / 2;
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size_t filesize;
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void *file, *pattern, *patch;
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mmap_rw(image, &file, &filesize);
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pattern = xmalloc(patternsize);
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patch = xmalloc(patchsize);
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hex2byte(from, pattern);
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hex2byte(to, patch);
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for (size_t i = 0; filesize > 0 && i < filesize - patternsize; ++i) {
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if (memcmp(file + i, pattern, patternsize) == 0) {
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fprintf(stderr, "Patch @ %08X [%s]->[%s]\n", (unsigned) i, from, to);
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memset(file + i, 0, patternsize);
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memcpy(file + i, patch, patchsize);
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i += patternsize - 1;
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}
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}
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munmap(file, filesize);
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free(pattern);
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free(patch);
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}
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