Magisk/jni/magiskboot/boot_utils.c

#include "magiskboot.h"

char *SUP_LIST[] = { "gzip", "xz", "lzma", "bzip2", "lz4", "lz4_legacy", NULL };
char *SUP_EXT_LIST[] = { "gz", "xz", "lzma", "bz2", "lz4", "lz4", NULL };
file_t SUP_TYPE_LIST[] = { GZIP, XZ, LZMA, BZIP2, LZ4, LZ4_LEGACY, 0 };

void mmap_ro(const char *filename, unsigned char **buf, size_t *size) {
	int fd = xopen(filename, O_RDONLY);
	*size = lseek(fd, 0, SEEK_END);
	lseek(fd, 0, SEEK_SET);
	*buf = xmmap(NULL, *size, PROT_READ, MAP_SHARED, fd, 0);
	close(fd);
}

void mmap_rw(const char *filename, unsigned char **buf, size_t *size) {
	int fd = xopen(filename, O_RDWR);
	*size = lseek(fd, 0, SEEK_END);
	lseek(fd, 0, SEEK_SET);
	*buf = xmmap(NULL, *size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	close(fd);
}

file_t check_type(const unsigned char *buf) {
	if (memcmp(buf, CHROMEOS_MAGIC, 8) == 0) {
		return CHROMEOS;
	} else if (memcmp(buf, BOOT_MAGIC, BOOT_MAGIC_SIZE) == 0) {
		return AOSP;
	} else if (memcmp(buf, ELF32_MAGIC, 5) == 0) {
		return ELF32;
	} else if (memcmp(buf, ELF64_MAGIC, 5) == 0) {
		return ELF64;
	} else if (memcmp(buf, "\x1f\x8b\x08\x00", 4) == 0) {
		return GZIP;
	} else if (memcmp(buf, "\x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a", 9) == 0) {
		return LZOP;
	} else if (memcmp(buf, "\xfd""7zXZ\x00", 6) == 0) {
		return XZ;
	} else if (memcmp(buf, "\x5d\x00\x00", 3) == 0 
			&& (buf[12] == (unsigned char) '\xff' || buf[12] == (unsigned char) '\x00')) {
		return LZMA;
	} else if (memcmp(buf, "BZh", 3) == 0) {
		return BZIP2;
	} else if (memcmp(buf, "\x04\x22\x4d\x18", 4) == 0) {
		return LZ4;
	} else if (memcmp(buf, "\x02\x21\x4c\x18", 4) == 0) {
		return LZ4_LEGACY;
	} else if (memcmp(buf, "\x88\x16\x88\x58", 4) == 0) {
		return MTK;
	} else {
		return UNKNOWN;
	}
}

void write_zero(int fd, size_t size) {
	size_t pos = lseek(fd, 0, SEEK_CUR);
	ftruncate(fd, pos + size);
	lseek(fd, pos + size, SEEK_SET);
}

void mem_align(size_t *pos, size_t align) {
	size_t mask = align - 1;
	if (*pos & mask) {
		*pos += align - (*pos & mask);
	}
}

void file_align(int fd, size_t align, int out) {
	size_t pos = lseek(fd, 0, SEEK_CUR);
	size_t mask = align - 1;
	size_t off;
	if (pos & mask) {
		off = align - (pos & mask);
		if (out) {
			write_zero(fd, off);
		} else {
			lseek(fd, pos + off, SEEK_SET);
		}
	}
}

int open_new(const char *filename) {
	return xopen(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
}

void cleanup() {
	fprintf(stderr, "Cleaning up...\n");
	char name[PATH_MAX];
	unlink(KERNEL_FILE);
	unlink(RAMDISK_FILE);
	unlink(RAMDISK_FILE ".unsupport");
	unlink(SECOND_FILE);
	unlink(DTB_FILE);
	for (int i = 0; SUP_EXT_LIST[i]; ++i) {
		sprintf(name, "%s.%s", RAMDISK_FILE, SUP_EXT_LIST[i]);
		unlink(name);
	}
}