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mirror of https://github.com/topjohnwu/Magisk.git synced 2024-12-20 23:17:37 +00:00
2021-10-09 02:15:03 -07:00

360 lines
11 KiB
C++

#include <dlfcn.h>
#include <sys/types.h>
#include <vector>
#include <map>
#include <resetprop.hpp>
#include <utils.hpp>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <_system_properties.h>
#include "_resetprop.hpp"
using namespace std;
static bool verbose = false;
#ifdef APPLET_STUB_MAIN
#define system_property_set __system_property_set
#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_read(...)
extern "C" int fsetxattr(int fd, const char* name, const void* value, size_t size, int flags) {
return syscall(__NR_fsetxattr, fd, name, value, size, flags);
}
#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*);
#define DLOAD(name) \
*(void **) &name = dlsym(RTLD_DEFAULT, "__" #name)
static void load_functions() {
DLOAD(system_property_set);
DLOAD(system_property_read);
DLOAD(system_property_find);
DLOAD(system_property_read_callback);
DLOAD(system_property_foreach);
}
#undef DLOAD
#endif
[[noreturn]] static void usage(char* arg0) {
fprintf(stderr,
R"EOF(resetprop - System Property Manipulation Tool
Usage: %s [flags] [options...]
Options:
-h, --help show this message
(no arguments) print all properties
NAME get property
NAME VALUE set property entry NAME with VALUE
--file FILE load props from FILE
--delete NAME delete property
Flags:
-v print verbose output to stderr
-n set props without going through property_service
(this flag only affects setprop)
-p read/write props from/to persistent storage
(this flag only affects getprop and delprop)
)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(const prop_info *pi, void *cb) {
if (system_property_read_callback) {
auto callback = [](void *cb, const char *name, const char *value, uint32_t) {
static_cast<prop_cb*>(cb)->exec(name, value);
};
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);
}
}
struct sysprop_stub {
virtual int setprop(const char *name, const char *value, bool trigger) { return 1; }
virtual string getprop(const char *name, bool persist) { return string(); }
virtual void getprops(void (*callback)(const char *, const char *, void *),
void *cookie, bool persist) {}
virtual int delprop(const char *name, bool persist) { return 1; }
};
struct sysprop : public sysprop_stub {
int setprop(const char *name, const char *value, bool) override {
if (!check_legal_property_name(name))
return 1;
return system_property_set(name, value);
}
struct prop_to_string : prop_cb {
explicit prop_to_string(string &s) : val(s) {}
void exec(const char *, const char *value) override {
val = value;
}
private:
string &val;
};
string getprop(const char *name, bool) override {
string val;
if (!check_legal_property_name(name))
return val;
auto pi = system_property_find(name);
if (pi == nullptr)
return val;
auto prop = prop_to_string(val);
read_prop(pi, &prop);
LOGD("resetprop: getprop [%s]: [%s]\n", name, val.data());
return val;
}
void getprops(void (*callback)(const char*, const char*, void*), void *cookie, bool) override {
prop_list list;
prop_collector collector(list);
system_property_foreach(read_prop, &collector);
for (auto &[key, val] : list)
callback(key.data(), val.data(), cookie);
}
};
struct resetprop : public sysprop {
int setprop(const char *name, const char *value, bool prop_svc) override {
if (!check_legal_property_name(name))
return 1;
const char *msg = prop_svc ? "property_service" : "modifying prop data structure";
int ret;
auto pi = const_cast<prop_info *>(__system_property_find(name));
// Always delete existing read-only properties, because they could be
// long properties and cannot directly go through __system_property_update
if (pi != nullptr && str_starts(name, "ro.")) {
__system_property_delete(name, false /* Do NOT trim node */);
pi = nullptr;
}
if (pi != nullptr) {
if (prop_svc) {
ret = system_property_set(name, value);
} else {
ret = __system_property_update(pi, value, strlen(value));
}
LOGD("resetprop: update prop [%s]: [%s] by %s\n", name, value, msg);
} else {
if (prop_svc) {
ret = system_property_set(name, value);
} else {
ret = __system_property_add(name, strlen(name), value, strlen(value));
}
LOGD("resetprop: create prop [%s]: [%s] by %s\n", name, value, msg);
}
if (ret)
LOGW("resetprop: setprop error\n");
return ret;
}
string getprop(const char *name, bool persist) override {
string val = sysprop::getprop(name, persist);
if (val.empty() && persist && strncmp(name, "persist.", 8) == 0)
val = persist_getprop(name);
if (val.empty())
LOGD("resetprop: prop [%s] does not exist\n", name);
return val;
}
void getprops(void (*callback)(const char *, const char *, void *),
void *cookie, bool persist) override {
prop_list list;
prop_collector collector(list);
system_property_foreach(read_prop, &collector);
if (persist)
persist_getprops(&collector);
for (auto &[key, val] : list)
callback(key.data(), val.data(), cookie);
}
// Not an error when something is deleted
int delprop(const char *name, bool persist) override {
if (!check_legal_property_name(name))
return 1;
LOGD("resetprop: delete prop [%s]\n", name);
int ret = __system_property_delete(name, true);
if (persist && str_starts(name, "persist.")) {
if (persist_deleteprop(name))
ret = 0;
}
return ret;
}
};
static sysprop_stub *get_impl() {
static sysprop_stub *impl = nullptr;
if (impl == nullptr) {
use_pb = access(PERSISTENT_PROPERTY_DIR "/persistent_properties", R_OK) == 0;
#ifdef APPLET_STUB_MAIN
if (__system_properties_init()) {
LOGE("resetprop: __system_properties_init error\n");
exit(1);
}
impl = new resetprop();
#else
// Load platform implementations
load_functions();
if (__system_properties_init()) {
LOGW("resetprop: __system_properties_init error\n");
impl = new sysprop();
} else {
impl = new resetprop();
}
#endif
}
return impl;
}
/***********************************
* Implementation of top-level APIs
***********************************/
static void print_props(bool persist) {
getprops([](const char *name, const char *value, auto) {
printf("[%s]: [%s]\n", name, value);
}, nullptr, persist);
}
string getprop(const char *name, bool persist) {
return get_impl()->getprop(name, persist);
}
void getprops(void (*callback)(const char *, const char *, void *), void *cookie, bool persist) {
get_impl()->getprops(callback, cookie, persist);
}
int setprop(const char *name, const char *value, bool prop_svc) {
return get_impl()->setprop(name, value, prop_svc);
}
int delprop(const char *name, bool persist) {
return get_impl()->delprop(name, persist);
}
void load_prop_file(const char *filename, bool prop_svc) {
auto impl = get_impl();
LOGD("resetprop: Parse prop file [%s]\n", filename);
parse_prop_file(filename, [=](auto key, auto val) -> bool {
impl->setprop(key.data(), val.data(), prop_svc);
return true;
});
}
int resetprop_main(int argc, char *argv[]) {
log_cb.d = [](auto fmt, auto ap) -> int { return verbose ? vfprintf(stderr, fmt, ap) : 0; };
bool prop_svc = true;
bool persist = false;
char *argv0 = argv[0];
--argc;
++argv;
// Parse flags and -- options
while (argc && argv[0][0] == '-') {
for (int idx = 1; true; ++idx) {
switch (argv[0][idx]) {
case '-':
if (strcmp(argv[0], "--file") == 0 && argc == 2) {
load_prop_file(argv[1], prop_svc);
return 0;
} else if (strcmp(argv[0], "--delete") == 0 && argc == 2) {
return delprop(argv[1], persist);
} else if (strcmp(argv[0], "--help") == 0) {
usage(argv0);
}
case 'v':
verbose = true;
continue;
case 'p':
persist = true;
continue;
case 'n':
prop_svc = false;
continue;
case '\0':
break;
case 'h':
default:
usage(argv0);
}
break;
}
--argc;
++argv;
}
switch (argc) {
case 0:
print_props(persist);
return 0;
case 1: {
string prop = getprop(argv[0], persist);
if (prop.empty())
return 1;
printf("%s\n", prop.data());
return 0;
}
case 2:
return setprop(argv[0], argv[1], prop_svc);
default:
usage(argv0);
}
}