Magisk/native/src/core/resetprop/resetprop.cpp
2024-05-18 13:55:33 +08:00

461 lines
13 KiB
C++

#include <dlfcn.h>
#include <sys/types.h>
#include <vector>
#include <map>
#include <base.hpp>
#include <core.hpp>
#include <resetprop.hpp>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <api/_system_properties.h>
#include <system_properties/prop_info.h>
using namespace std;
#ifdef APPLET_STUB_MAIN
#define system_property_set __system_property_set
#define system_property_read(...)
#define system_property_find __system_property_find
#define system_property_read_callback __system_property_read_callback
#define system_property_foreach __system_property_foreach
#define system_property_wait __system_property_wait
#else
static int (*system_property_set)(const char*, const char*);
static int (*system_property_read)(const prop_info*, char*, char*);
static const prop_info *(*system_property_find)(const char*);
static void (*system_property_read_callback)(
const prop_info*, void (*)(void*, const char*, const char*, uint32_t), void*);
static int (*system_property_foreach)(void (*)(const prop_info*, void*), void*);
static bool (*system_property_wait)(const prop_info*, uint32_t, uint32_t*, const struct timespec*);
#endif
struct PropFlags {
void setSkipSvc() { flags |= 1; }
void setPersist() { flags |= (1 << 1); }
void setContext() { flags |= (1 << 2); }
void setPersistOnly() { flags |= (1 << 3); setPersist(); }
void setWait() { flags |= (1 << 4); }
bool isSkipSvc() const { return flags & 1; }
bool isPersist() const { return flags & (1 << 1); }
bool isContext() const { return flags & (1 << 2); }
bool isPersistOnly() const { return flags & (1 << 3); }
bool isWait() const { return flags & (1 << 4); }
private:
uint32_t flags = 0;
};
[[noreturn]] static void usage(char* arg0) {
fprintf(stderr,
R"EOF(resetprop - System Property Manipulation Tool
Usage: %s [flags] [arguments...]
Read mode arguments:
(no arguments) print all properties
NAME get property of NAME
Write mode arguments:
NAME VALUE set property NAME as VALUE
-f,--file FILE load and set properties from FILE
-d,--delete NAME delete property
Wait mode arguments (toggled with -w):
NAME wait until property NAME changes
NAME OLD_VALUE if value of property NAME is not OLD_VALUE, get value
or else wait until property NAME changes
General flags:
-h,--help show this message
-v print verbose output to stderr
-w switch to wait mode
Read mode flags:
-p also read persistent props from storage
-P only read persistent props from storage
-Z get property context instead of value
Write mode flags:
-n set properties bypassing property_service
-p always write persistent prop changes to storage
)EOF", arg0);
exit(1);
}
static bool check_legal_property_name(const char *name) {
int namelen = strlen(name);
if (namelen < 1) goto illegal;
if (name[0] == '.') goto illegal;
if (name[namelen - 1] == '.') goto illegal;
/* Only allow alphanumeric, plus '.', '-', '@', ':', or '_' */
/* Don't allow ".." to appear in a property name */
for (size_t i = 0; i < namelen; i++) {
if (name[i] == '.') {
// i=0 is guaranteed to never have a dot. See above.
if (name[i-1] == '.') goto illegal;
continue;
}
if (name[i] == '_' || name[i] == '-' || name[i] == '@' || name[i] == ':') continue;
if (name[i] >= 'a' && name[i] <= 'z') continue;
if (name[i] >= 'A' && name[i] <= 'Z') continue;
if (name[i] >= '0' && name[i] <= '9') continue;
goto illegal;
}
return true;
illegal:
LOGE("Illegal property name: [%s]\n", name);
return false;
}
static void read_prop_with_cb(const prop_info *pi, void *cb) {
if (system_property_read_callback) {
auto callback = [](void *cb, const char *name, const char *value, uint32_t serial) {
static_cast<prop_cb*>(cb)->exec(name, value, serial);
};
system_property_read_callback(pi, callback, cb);
} else {
char name[PROP_NAME_MAX];
char value[PROP_VALUE_MAX];
name[0] = '\0';
value[0] = '\0';
system_property_read(pi, name, value);
static_cast<prop_cb*>(cb)->exec(name, value, pi->serial);
}
}
template<class StringType>
struct prop_to_string : prop_cb {
void exec(const char *, const char *value, uint32_t s) override {
val = value;
serial = s;
}
StringType val;
uint32_t serial;
};
template<> void prop_to_string<rust::String>::exec(const char *, const char *value, uint32_t s) {
// We do not want to crash when values are not UTF-8
val = rust::String::lossy(value);
serial = s;
}
static int set_prop(const char *name, const char *value, PropFlags flags) {
if (!check_legal_property_name(name))
return 1;
auto pi = const_cast<prop_info *>(__system_property_find(name));
// Delete existing read-only properties if they are or will be long properties,
// which cannot directly go through __system_property_update
if (str_starts(name, "ro.")) {
if (pi != nullptr && (pi->is_long() || strlen(value) >= PROP_VALUE_MAX)) {
// Skip pruning nodes as we will add it back ASAP
__system_property_delete(name, false);
pi = nullptr;
}
flags.setSkipSvc();
}
const char *msg = flags.isSkipSvc() ? "direct modification" : "property_service";
int ret;
if (pi != nullptr) {
if (flags.isSkipSvc()) {
ret = __system_property_update(pi, value, strlen(value));
} else {
ret = system_property_set(name, value);
}
LOGD("resetprop: update prop [%s]: [%s] by %s\n", name, value, msg);
} else {
if (flags.isSkipSvc()) {
ret = __system_property_add(name, strlen(name), value, strlen(value));
} else {
ret = system_property_set(name, value);
}
LOGD("resetprop: create prop [%s]: [%s] by %s\n", name, value, msg);
}
// When bypassing property_service, persistent props won't be stored in storage.
// Explicitly handle this situation.
if (ret == 0 && flags.isSkipSvc() && flags.isPersist() && str_starts(name, "persist.")) {
ret = persist_set_prop(name, value) ? 0 : 1;
}
if (ret) {
LOGW("resetprop: set prop error\n");
}
return ret;
}
template<class StringType>
static StringType get_prop(const char *name, PropFlags flags) {
if (!check_legal_property_name(name))
return {};
prop_to_string<StringType> cb;
if (flags.isContext()) {
auto context = __system_property_get_context(name) ?: "";
LOGD("resetprop: prop context [%s]: [%s]\n", name, context);
cb.exec(name, context, -1);
return cb.val;
}
if (!flags.isPersistOnly()) {
if (auto pi = system_property_find(name)) {
read_prop_with_cb(pi, &cb);
LOGD("resetprop: get prop [%s]: [%s]\n", name, cb.val.c_str());
}
}
if (cb.val.empty() && flags.isPersist() && str_starts(name, "persist."))
persist_get_prop(name, cb);
if (cb.val.empty())
LOGD("resetprop: prop [%s] does not exist\n", name);
return cb.val;
}
template<class StringType>
static StringType wait_prop(const char *name, const char *old_value) {
if (!check_legal_property_name(name))
return {};
const prop_info *pi;
auto serial = __system_property_area_serial();
while (!(pi = system_property_find(name))) {
LOGD("resetprop: waiting for prop [%s] to exist\n", name);
system_property_wait(nullptr, serial, &serial, nullptr);
}
prop_to_string<StringType> cb;
read_prop_with_cb(pi, &cb);
while (old_value == nullptr || cb.val == old_value) {
LOGD("resetprop: waiting for prop [%s]\n", name);
uint32_t new_serial;
system_property_wait(pi, cb.serial, &new_serial, nullptr);
read_prop_with_cb(pi, &cb);
if (old_value == nullptr) break;
}
LOGD("resetprop: get prop [%s]: [%s]\n", name, cb.val.c_str());
return cb.val;
}
static void print_props(PropFlags flags) {
prop_list list;
prop_collector collector(list);
if (!flags.isPersistOnly())
system_property_foreach(read_prop_with_cb, &collector);
if (flags.isPersist())
persist_get_props(collector);
for (auto &[key, val] : list) {
const char *v = flags.isContext() ?
(__system_property_get_context(key.data()) ?: "") :
val.data();
printf("[%s]: [%s]\n", key.data(), v);
}
}
static int delete_prop(const char *name, PropFlags flags) {
if (!check_legal_property_name(name))
return 1;
LOGD("resetprop: delete prop [%s]\n", name);
int ret = __system_property_delete(name, true);
if (flags.isPersist() && str_starts(name, "persist.")) {
if (persist_delete_prop(name))
ret = 0;
}
return ret;
}
static void load_file(const char *filename, PropFlags flags) {
LOGD("resetprop: Parse prop file [%s]\n", filename);
parse_prop_file(filename, [=](auto key, auto val) -> bool {
set_prop(key.data(), val.data(), flags);
return true;
});
}
struct Initialize {
Initialize() {
#ifndef APPLET_STUB_MAIN
#define DLOAD(name) (*(void **) &name = dlsym(RTLD_DEFAULT, "__" #name))
// Load platform implementations
DLOAD(system_property_set);
DLOAD(system_property_read);
DLOAD(system_property_find);
DLOAD(system_property_read_callback);
DLOAD(system_property_foreach);
DLOAD(system_property_wait);
#undef DLOAD
if (system_property_wait == nullptr) {
// The platform API only exist on API 26+
system_property_wait = __system_property_wait;
}
#endif
if (__system_properties_init()) {
LOGE("resetprop: __system_properties_init error\n");
}
}
};
static void InitOnce() {
static struct Initialize init;
}
#define consume_next(val) \
if (argc != 2) usage(argv0); \
val = argv[1]; \
stop_parse = true; \
int resetprop_main(int argc, char *argv[]) {
PropFlags flags;
char *argv0 = argv[0];
set_log_level_state(LogLevel::Debug, false);
const char *prop_file = nullptr;
const char *prop_to_rm = nullptr;
--argc;
++argv;
// Parse flags and -- options
while (argc && argv[0][0] == '-') {
bool stop_parse = false;
for (int idx = 1; true; ++idx) {
switch (argv[0][idx]) {
case '-':
if (argv[0] == "--file"sv) {
consume_next(prop_file);
} else if (argv[0] == "--delete"sv) {
consume_next(prop_to_rm);
} else {
usage(argv0);
}
break;
case 'd':
consume_next(prop_to_rm);
continue;
case 'f':
consume_next(prop_file);
continue;
case 'n':
flags.setSkipSvc();
continue;
case 'p':
flags.setPersist();
continue;
case 'P':
flags.setPersistOnly();
continue;
case 'v':
set_log_level_state(LogLevel::Debug, true);
continue;
case 'Z':
flags.setContext();
continue;
case 'w':
flags.setWait();
continue;
case '\0':
break;
default:
usage(argv0);
}
break;
}
--argc;
++argv;
if (stop_parse)
break;
}
InitOnce();
if (prop_to_rm) {
return delete_prop(prop_to_rm, flags);
}
if (prop_file) {
load_file(prop_file, flags);
return 0;
}
if (flags.isWait()) {
if (argc == 0) usage(argv0);
auto val = wait_prop<string>(argv[0], argv[1]);
if (val.empty())
return 1;
printf("%s\n", val.data());
return 0;
}
switch (argc) {
case 0:
print_props(flags);
return 0;
case 1: {
auto val = get_prop<string>(argv[0], flags);
if (val.empty())
return 1;
printf("%s\n", val.data());
return 0;
}
case 2:
return set_prop(argv[0], argv[1], flags);
default:
usage(argv0);
}
}
/***************
* Public APIs
****************/
template<class StringType>
static StringType get_prop_impl(const char *name, bool persist) {
InitOnce();
PropFlags flags;
if (persist) flags.setPersist();
return get_prop<StringType>(name, flags);
}
rust::String get_prop_rs(const char *name, bool persist) {
return get_prop_impl<rust::String>(name, persist);
}
string get_prop(const char *name, bool persist) {
return get_prop_impl<string>(name, persist);
}
int delete_prop(const char *name, bool persist) {
InitOnce();
PropFlags flags;
if (persist) flags.setPersist();
return delete_prop(name, flags);
}
int set_prop(const char *name, const char *value, bool skip_svc) {
InitOnce();
PropFlags flags;
if (skip_svc) flags.setSkipSvc();
return set_prop(name, value, flags);
}
void load_prop_file(const char *filename, bool skip_svc) {
InitOnce();
PropFlags flags;
if (skip_svc) flags.setSkipSvc();
load_file(filename, flags);
}