Magisk/native/jni/magiskboot/ramdisk.cpp
2021-05-10 18:38:30 -07:00

344 lines
10 KiB
C++

#include <utils.hpp>
#include <cpio.hpp>
#include "magiskboot.hpp"
#include "compress.hpp"
using namespace std;
constexpr char RAMDISK_XZ[] = "ramdisk.cpio.xz";
static const char *UNSUPPORT_LIST[] =
{ "sbin/launch_daemonsu.sh", "sbin/su", "init.xposed.rc",
"boot/sbin/launch_daemonsu.sh" };
static const char *MAGISK_LIST[] =
{ ".backup/.magisk", "init.magisk.rc",
"overlay/init.magisk.rc" };
class magisk_cpio : public cpio_rw {
public:
magisk_cpio() = default;
explicit magisk_cpio(const char *filename) : cpio_rw(filename) {}
void patch();
int test();
char *sha1();
void restore();
void backup(const char *orig);
void compress();
void decompress();
};
bool check_env(const char *name) {
const char *val = getenv(name);
return val != nullptr && val == "true"sv;
}
void magisk_cpio::patch() {
bool keepverity = check_env("KEEPVERITY");
bool keepforceencrypt = check_env("KEEPFORCEENCRYPT");
fprintf(stderr, "Patch with flag KEEPVERITY=[%s] KEEPFORCEENCRYPT=[%s]\n",
keepverity ? "true" : "false", keepforceencrypt ? "true" : "false");
for (auto it = entries.begin(); it != entries.end();) {
auto cur = it++;
bool fstab = (!keepverity || !keepforceencrypt) &&
S_ISREG(cur->second->mode) &&
!str_starts(cur->first, ".backup") &&
!str_contains(cur->first, "twrp") &&
!str_contains(cur->first, "recovery") &&
str_contains(cur->first, "fstab");
if (!keepverity) {
if (fstab) {
fprintf(stderr, "Found fstab file [%s]\n", cur->first.data());
cur->second->filesize = patch_verity(cur->second->data, cur->second->filesize);
} else if (cur->first == "verity_key") {
rm(cur);
continue;
}
}
if (!keepforceencrypt) {
if (fstab) {
cur->second->filesize = patch_encryption(cur->second->data, cur->second->filesize);
}
}
}
}
#define STOCK_BOOT 0
#define MAGISK_PATCHED (1 << 0)
#define UNSUPPORTED_CPIO (1 << 1)
#define COMPRESSED_CPIO (1 << 2)
int magisk_cpio::test() {
for (auto file : UNSUPPORT_LIST)
if (exists(file))
return UNSUPPORTED_CPIO;
int flags = STOCK_BOOT;
if (exists(RAMDISK_XZ)) {
flags |= COMPRESSED_CPIO | MAGISK_PATCHED;
decompress();
}
for (auto file : MAGISK_LIST) {
if (exists(file)) {
flags |= MAGISK_PATCHED;
break;
}
}
return flags;
}
#define for_each_line(line, buf, size) \
for (line = (char *) buf; line < (char *) buf + size && line[0]; line = strchr(line + 1, '\n') + 1)
char *magisk_cpio::sha1() {
decompress();
char sha1[41];
char *line;
for (auto &e : entries) {
if (e.first == "init.magisk.rc" || e.first == "overlay/init.magisk.rc") {
for_each_line(line, e.second->data, e.second->filesize) {
if (strncmp(line, "#STOCKSHA1=", 11) == 0) {
strncpy(sha1, line + 12, 40);
sha1[40] = '\0';
return strdup(sha1);
}
}
} else if (e.first == ".backup/.magisk") {
for_each_line(line, e.second->data, e.second->filesize) {
if (strncmp(line, "SHA1=", 5) == 0) {
strncpy(sha1, line + 5, 40);
sha1[40] = '\0';
return strdup(sha1);
}
}
} else if (e.first == ".backup/.sha1") {
return (char *) e.second->data;
}
}
return nullptr;
}
#define for_each_str(str, buf, size) \
for (str = (char *) buf; str < (char *) buf + size; str = str += strlen(str) + 1)
void magisk_cpio::restore() {
decompress();
if (auto it = entries.find(".backup/.rmlist"); it != entries.end()) {
char *file;
for_each_str(file, it->second->data, it->second->filesize)
rm(file, false);
rm(it);
}
for (auto it = entries.begin(); it != entries.end();) {
auto cur = it++;
if (str_starts(cur->first, ".backup")) {
if (cur->first.length() == 7 || cur->first.substr(8) == ".magisk") {
rm(cur);
} else {
mv(cur, &cur->first[8]);
}
} else if (str_starts(cur->first, "magisk") ||
cur->first == "overlay/init.magisk.rc" ||
cur->first == "sbin/magic_mask.sh" ||
cur->first == "init.magisk.rc") {
// Some known stuff we can remove
rm(cur);
}
}
}
void magisk_cpio::backup(const char *orig) {
if (access(orig, R_OK))
return;
entry_map bkup_entries;
string remv;
auto b = new cpio_entry(".backup", S_IFDIR);
bkup_entries[b->filename].reset(b);
magisk_cpio o(orig);
// Remove possible backups in original ramdisk
o.rm(".backup", true);
rm(".backup", true);
auto lhs = o.entries.begin();
auto rhs = entries.begin();
while (lhs != o.entries.end() || rhs != entries.end()) {
int res;
bool backup = false;
if (lhs != o.entries.end() && rhs != entries.end()) {
res = lhs->first.compare(rhs->first);
} else if (lhs == o.entries.end()) {
res = 1;
} else {
res = -1;
}
if (res < 0) {
// Something is missing in new ramdisk, backup!
backup = true;
fprintf(stderr, "Backup missing entry: ");
} else if (res == 0) {
if (lhs->second->filesize != rhs->second->filesize ||
memcmp(lhs->second->data, rhs->second->data, lhs->second->filesize) != 0) {
// Not the same!
backup = true;
fprintf(stderr, "Backup mismatch entry: ");
}
} else {
// Something new in ramdisk
remv += rhs->first;
remv += (char) '\0';
fprintf(stderr, "Record new entry: [%s] -> [.backup/.rmlist]\n", rhs->first.data());
}
if (backup) {
string back_name(".backup/");
back_name += lhs->first;
fprintf(stderr, "[%s] -> [%s]\n", lhs->first.data(), back_name.data());
auto ex = static_cast<cpio_entry*>(lhs->second.release());
ex->filename = back_name;
bkup_entries[ex->filename].reset(ex);
}
// Increment positions
if (res < 0) {
++lhs;
} else if (res == 0) {
++lhs; ++rhs;
} else {
++rhs;
}
}
if (!remv.empty()) {
auto rmlist = new cpio_entry(".backup/.rmlist", S_IFREG);
rmlist->filesize = remv.length();
rmlist->data = xmalloc(remv.length());
memcpy(rmlist->data, remv.data(), remv.length());
bkup_entries[rmlist->filename].reset(rmlist);
}
if (bkup_entries.size() > 1)
entries.merge(bkup_entries);
}
void magisk_cpio::compress() {
if (exists(RAMDISK_XZ))
return;
fprintf(stderr, "Compressing cpio -> [%s]\n", RAMDISK_XZ);
auto init = entries.extract("init");
uint8_t *data;
size_t len;
auto strm = make_stream_fp(get_encoder(XZ, make_unique<byte_stream>(data, len)));
dump(strm.release());
entries.clear();
entries.insert(std::move(init));
auto xz = new cpio_entry(RAMDISK_XZ, S_IFREG);
xz->data = data;
xz->filesize = len;
insert(xz);
}
void magisk_cpio::decompress() {
auto it = entries.find(RAMDISK_XZ);
if (it == entries.end())
return;
fprintf(stderr, "Decompressing cpio [%s]\n", RAMDISK_XZ);
char *data;
size_t len;
{
auto strm = get_decoder(XZ, make_unique<byte_stream>(data, len));
strm->write(it->second->data, it->second->filesize);
}
entries.erase(it);
load_cpio(data, len);
free(data);
}
int cpio_commands(int argc, char *argv[]) {
char *incpio = argv[0];
++argv;
--argc;
magisk_cpio cpio;
if (access(incpio, R_OK) == 0)
cpio.load_cpio(incpio);
int cmdc;
char *cmdv[6];
for (int i = 0; i < argc; ++i) {
// Reset
cmdc = 0;
memset(cmdv, 0, sizeof(cmdv));
// Split the commands
char *tok = strtok(argv[i], " ");
while (tok && cmdc < std::size(cmdv)) {
if (cmdc == 0 && tok[0] == '#')
break;
cmdv[cmdc++] = tok;
tok = strtok(nullptr, " ");
}
if (cmdc == 0)
continue;
if (cmdv[0] == "test"sv) {
exit(cpio.test());
} else if (cmdv[0] == "restore"sv) {
cpio.restore();
} else if (cmdv[0] == "sha1"sv) {
char *sha1 = cpio.sha1();
if (sha1) printf("%s\n", sha1);
return 0;
} else if (cmdv[0] == "compress"sv){
cpio.compress();
} else if (cmdv[0] == "decompress"sv){
cpio.decompress();
} else if (cmdv[0] == "patch"sv) {
cpio.patch();
} else if (cmdc == 2 && cmdv[0] == "exists"sv) {
exit(!cpio.exists(cmdv[1]));
} else if (cmdc == 2 && cmdv[0] == "backup"sv) {
cpio.backup(cmdv[1]);
} else if (cmdc >= 2 && cmdv[0] == "rm"sv) {
bool r = cmdc > 2 && cmdv[1] == "-r"sv;
cpio.rm(cmdv[1 + r], r);
} else if (cmdc == 3 && cmdv[0] == "mv"sv) {
cpio.mv(cmdv[1], cmdv[2]);
} else if (cmdv[0] == "extract"sv) {
if (cmdc == 3) {
return !cpio.extract(cmdv[1], cmdv[2]);
} else {
cpio.extract();
return 0;
}
} else if (cmdc == 3 && cmdv[0] == "mkdir"sv) {
cpio.mkdir(strtoul(cmdv[1], nullptr, 8), cmdv[2]);
} else if (cmdc == 3 && cmdv[0] == "ln"sv) {
cpio.ln(cmdv[1], cmdv[2]);
} else if (cmdc == 4 && cmdv[0] == "add"sv) {
cpio.add(strtoul(cmdv[1], nullptr, 8), cmdv[2], cmdv[3]);
} else {
return 1;
}
}
cpio.dump(incpio);
return 0;
}