Magisk/native/jni/magiskboot/main.cpp

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <unistd.h>
#include <sys/mman.h>

#include <mincrypt/sha.h>
#include <utils.hpp>

#include "magiskboot.hpp"
#include "compress.hpp"

using namespace std;

static void usage(char *arg0) {
	fprintf(stderr,
R"EOF(MagiskBoot - Boot Image Modification Tool

Usage: %s <action> [args...]

Supported actions:
  unpack [-n] [-h] <bootimg>
    Unpack <bootimg> to, if available, kernel, kernel_dtb, ramdisk.cpio,
    second, dtb, extra, and recovery_dtbo into current directory.
    If '-n' is provided, it will not attempt to decompress kernel or
    ramdisk.cpio from their original formats.
    If '-h' is provided, it will dump header info to 'header',
    which will be parsed when repacking.
    Return values:
    0:valid    1:error    2:chromeos

  repack [-n] <origbootimg> [outbootimg]
    Repack boot image components from current directory
    to [outbootimg], or new-boot.img if not specified.
    If '-n' is provided, it will not attempt to recompress ramdisk.cpio,
    otherwise it will compress ramdisk.cpio and kernel with the same method
    in <origbootimg> if the file provided is not already compressed.

  hexpatch <file> <hexpattern1> <hexpattern2>
    Search <hexpattern1> in <file>, and replace with <hexpattern2>

  cpio <incpio> [commands...]
    Do cpio commands to <incpio> (modifications are done in-place)
    Each command is a single argument, add quotes for each command
    Supported commands:
      exists ENTRY
        Return 0 if ENTRY exists, else return 1
      rm [-r] ENTRY
        Remove ENTRY, specify [-r] to remove recursively
      mkdir MODE ENTRY
        Create directory ENTRY in permissions MODE
      ln TARGET ENTRY
        Create a symlink to TARGET with the name ENTRY
      mv SOURCE DEST
        Move SOURCE to DEST
      add MODE ENTRY INFILE
        Add INFILE as ENTRY in permissions MODE; replaces ENTRY if exists
      extract [ENTRY OUT]
        Extract ENTRY to OUT, or extract all entries to current directory
      test
        Test the current cpio's patch status
        Return values:
        0:stock    1:Magisk    2:unsupported (phh, SuperSU, Xposed)
      patch
        Apply ramdisk patches
        Configure with env variables: KEEPVERITY KEEPFORCEENCRYPT
      backup ORIG
        Create ramdisk backups from ORIG
      restore
        Restore ramdisk from ramdisk backup stored within incpio
      sha1
        Print stock boot SHA1 if previously backed up in ramdisk

  dtb <input> <action> [args...]
    Do dtb related actions to <input>
    Supported actions:
      print [-f]
        Print all contents of dtb for debugging
        Specify [-f] to only print fstab nodes
      patch
        Search for fstab and remove verity/avb
        Modifications are done directly to the file in-place
        Configure with env variables: KEEPVERITY

  split <input>
    Split image.*-dtb into kernel + kernel_dtb

  sha1 <file>
    Print the SHA1 checksum for <file>

  cleanup
    Cleanup the current working directory

  compress[=method] <infile> [outfile]
    Compress <infile> with [method] (default: gzip), optionally to [outfile]
    <infile>/[outfile] can be '-' to be STDIN/STDOUT
    Supported methods: )EOF", arg0);

	for (auto &it : name2fmt)
		fprintf(stderr, "%s ", it.first.data());

	fprintf(stderr, R"EOF(

  decompress <infile> [outfile]
    Detect method and decompress <infile>, optionally to [outfile]
    <infile>/[outfile] can be '-' to be STDIN/STDOUT
    Supported methods: )EOF");

	for (auto &it : name2fmt)
		fprintf(stderr, "%s ", it.first.data());

	fprintf(stderr, "\n\n");
	exit(1);
}

int main(int argc, char *argv[]) {
	cmdline_logging();
	umask(0);

	if (argc < 2)
		usage(argv[0]);

	// Skip '--' for backwards compatibility
	string_view action(argv[1]);
	if (str_starts(action, "--"))
		action = argv[1] + 2;

	if (action == "cleanup") {
		fprintf(stderr, "Cleaning up...\n");
		unlink(HEADER_FILE);
		unlink(KERNEL_FILE);
		unlink(RAMDISK_FILE);
		unlink(SECOND_FILE);
		unlink(KER_DTB_FILE);
		unlink(EXTRA_FILE);
		unlink(RECV_DTBO_FILE);
		unlink(DTB_FILE);
	} else if (argc > 2 && action == "sha1") {
		uint8_t sha1[SHA_DIGEST_SIZE];
		void *buf;
		size_t size;
		mmap_ro(argv[2], buf, size);
		SHA_hash(buf, size, sha1);
		for (uint8_t i : sha1)
			printf("%02x", i);
		printf("\n");
		munmap(buf, size);
	} else if (argc > 2 && action == "split") {
		return split_image_dtb(argv[2]);
	} else if (argc > 2 && action == "unpack") {
		int idx = 2;
		bool nodecomp = false;
		bool hdr = false;
		for (;;) {
			if (idx >= argc)
				usage(argv[0]);
			if (argv[idx][0] != '-')
				break;
			for (char *flag = &argv[idx][1]; *flag; ++flag) {
				if (*flag == 'n')
					nodecomp = true;
				else if (*flag == 'h')
					hdr = true;
				else
					usage(argv[0]);
			}
			++idx;
		}
		return unpack(argv[idx], nodecomp, hdr);
	} else if (argc > 2 && action == "repack") {
		if (argv[2] == "-n"sv) {
			if (argc == 3)
				usage(argv[0]);
			repack(argv[3], argv[4] ? argv[4] : NEW_BOOT, true);
		} else {
			repack(argv[2], argv[3] ? argv[3] : NEW_BOOT);
		}
	} else if (argc > 2 && action == "decompress") {
		decompress(argv[2], argv[3]);
	} else if (argc > 2 && str_starts(action, "compress")) {
		compress(action[8] == '=' ? &action[9] : "gzip", argv[2], argv[3]);
	} else if (argc > 4 && action == "hexpatch") {
		return hexpatch(argv[2], argv[3], argv[4]);
	} else if (argc > 2 && action == "cpio"sv) {
		if (cpio_commands(argc - 2, argv + 2))
			usage(argv[0]);
	} else if (argc > 3 && action == "dtb") {
		if (dtb_commands(argc - 2, argv + 2))
			usage(argv[0]);
	} else {
		usage(argv[0]);
	}

	return 0;
}