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platform_system_core/init/property_service.cpp
Steven Laver 57a740eca2 Allow properties to be derived from partition-specific properties during init 
If not present, ro.product.[brand|device|manufacturer|model|name] and
ro.build.fingerprint will be resolved during init from
partition-specific properties.

Test: booted system image, verified properties
Test: booted recovery image, verified properties
Bug: 120123525
Change-Id: I7fe2793a7d9eb65645d92ceb408f1f050acf9a81
2019-02-07 16:15:55 -08:00

957 lines
33 KiB
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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "property_service.h"
#include <android/api-level.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <netinet/in.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/poll.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/un.h>
#include <unistd.h>
#include <wchar.h>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
#include <memory>
#include <queue>
#include <vector>
#include <android-base/chrono_utils.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <property_info_parser/property_info_parser.h>
#include <property_info_serializer/property_info_serializer.h>
#include <selinux/android.h>
#include <selinux/label.h>
#include <selinux/selinux.h>
#include "epoll.h"
#include "init.h"
#include "persistent_properties.h"
#include "property_type.h"
#include "selinux.h"
#include "subcontext.h"
#include "util.h"
using namespace std::literals;
using android::base::GetProperty;
using android::base::ReadFileToString;
using android::base::Split;
using android::base::StartsWith;
using android::base::StringPrintf;
using android::base::Timer;
using android::base::Trim;
using android::base::WriteStringToFile;
using android::properties::BuildTrie;
using android::properties::ParsePropertyInfoFile;
using android::properties::PropertyInfoAreaFile;
using android::properties::PropertyInfoEntry;
namespace android {
namespace init {
static bool persistent_properties_loaded = false;
static int property_set_fd = -1;
static PropertyInfoAreaFile property_info_area;
uint32_t InitPropertySet(const std::string& name, const std::string& value);
uint32_t (*property_set)(const std::string& name, const std::string& value) = InitPropertySet;
void CreateSerializedPropertyInfo();
struct PropertyAuditData {
const ucred* cr;
const char* name;
};
void property_init() {
mkdir("/dev/__properties__", S_IRWXU | S_IXGRP | S_IXOTH);
CreateSerializedPropertyInfo();
if (__system_property_area_init()) {
LOG(FATAL) << "Failed to initialize property area";
}
if (!property_info_area.LoadDefaultPath()) {
LOG(FATAL) << "Failed to load serialized property info file";
}
}
bool CanReadProperty(const std::string& source_context, const std::string& name) {
const char* target_context = nullptr;
property_info_area->GetPropertyInfo(name.c_str(), &target_context, nullptr);
PropertyAuditData audit_data;
audit_data.name = name.c_str();
ucred cr = {.pid = 0, .uid = 0, .gid = 0};
audit_data.cr = &cr;
return selinux_check_access(source_context.c_str(), target_context, "file", "read",
&audit_data) == 0;
}
static bool CheckMacPerms(const std::string& name, const char* target_context,
const char* source_context, const ucred& cr) {
if (!target_context || !source_context) {
return false;
}
PropertyAuditData audit_data;
audit_data.name = name.c_str();
audit_data.cr = &cr;
bool has_access = (selinux_check_access(source_context, target_context, "property_service",
"set", &audit_data) == 0);
return has_access;
}
static uint32_t PropertySet(const std::string& name, const std::string& value, std::string* error) {
size_t valuelen = value.size();
if (!IsLegalPropertyName(name)) {
*error = "Illegal property name";
return PROP_ERROR_INVALID_NAME;
}
if (valuelen >= PROP_VALUE_MAX && !StartsWith(name, "ro.")) {
*error = "Property value too long";
return PROP_ERROR_INVALID_VALUE;
}
if (mbstowcs(nullptr, value.data(), 0) == static_cast<std::size_t>(-1)) {
*error = "Value is not a UTF8 encoded string";
return PROP_ERROR_INVALID_VALUE;
}
prop_info* pi = (prop_info*) __system_property_find(name.c_str());
if (pi != nullptr) {
// ro.* properties are actually "write-once".
if (StartsWith(name, "ro.")) {
*error = "Read-only property was already set";
return PROP_ERROR_READ_ONLY_PROPERTY;
}
__system_property_update(pi, value.c_str(), valuelen);
} else {
int rc = __system_property_add(name.c_str(), name.size(), value.c_str(), valuelen);
if (rc < 0) {
*error = "__system_property_add failed";
return PROP_ERROR_SET_FAILED;
}
}
// Don't write properties to disk until after we have read all default
// properties to prevent them from being overwritten by default values.
if (persistent_properties_loaded && StartsWith(name, "persist.")) {
WritePersistentProperty(name, value);
}
property_changed(name, value);
return PROP_SUCCESS;
}
typedef int (*PropertyAsyncFunc)(const std::string&, const std::string&);
struct PropertyChildInfo {
pid_t pid;
PropertyAsyncFunc func;
std::string name;
std::string value;
};
static std::queue<PropertyChildInfo> property_children;
static void PropertyChildLaunch() {
auto& info = property_children.front();
pid_t pid = fork();
if (pid < 0) {
LOG(ERROR) << "Failed to fork for property_set_async";
while (!property_children.empty()) {
property_children.pop();
}
return;
}
if (pid != 0) {
info.pid = pid;
} else {
if (info.func(info.name, info.value) != 0) {
LOG(ERROR) << "property_set_async(\"" << info.name << "\", \"" << info.value
<< "\") failed";
}
_exit(0);
}
}
bool PropertyChildReap(pid_t pid) {
if (property_children.empty()) {
return false;
}
auto& info = property_children.front();
if (info.pid != pid) {
return false;
}
std::string error;
if (PropertySet(info.name, info.value, &error) != PROP_SUCCESS) {
LOG(ERROR) << "Failed to set async property " << info.name << " to " << info.value << ": "
<< error;
}
property_children.pop();
if (!property_children.empty()) {
PropertyChildLaunch();
}
return true;
}
static uint32_t PropertySetAsync(const std::string& name, const std::string& value,
PropertyAsyncFunc func, std::string* error) {
if (value.empty()) {
return PropertySet(name, value, error);
}
PropertyChildInfo info;
info.func = func;
info.name = name;
info.value = value;
property_children.push(info);
if (property_children.size() == 1) {
PropertyChildLaunch();
}
return PROP_SUCCESS;
}
static int RestoreconRecursiveAsync(const std::string& name, const std::string& value) {
return selinux_android_restorecon(value.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE);
}
uint32_t InitPropertySet(const std::string& name, const std::string& value) {
if (StartsWith(name, "ctl.")) {
LOG(ERROR) << "InitPropertySet: Do not set ctl. properties from init; call the Service "
"functions directly";
return PROP_ERROR_INVALID_NAME;
}
if (name == "selinux.restorecon_recursive") {
LOG(ERROR) << "InitPropertySet: Do not set selinux.restorecon_recursive from init; use the "
"restorecon builtin directly";
return PROP_ERROR_INVALID_NAME;
}
uint32_t result = 0;
ucred cr = {.pid = 1, .uid = 0, .gid = 0};
std::string error;
result = HandlePropertySet(name, value, kInitContext.c_str(), cr, &error);
if (result != PROP_SUCCESS) {
LOG(ERROR) << "Init cannot set '" << name << "' to '" << value << "': " << error;
}
return result;
}
class SocketConnection {
public:
SocketConnection(int socket, const ucred& cred) : socket_(socket), cred_(cred) {}
~SocketConnection() { close(socket_); }
bool RecvUint32(uint32_t* value, uint32_t* timeout_ms) {
return RecvFully(value, sizeof(*value), timeout_ms);
}
bool RecvChars(char* chars, size_t size, uint32_t* timeout_ms) {
return RecvFully(chars, size, timeout_ms);
}
bool RecvString(std::string* value, uint32_t* timeout_ms) {
uint32_t len = 0;
if (!RecvUint32(&len, timeout_ms)) {
return false;
}
if (len == 0) {
*value = "";
return true;
}
// http://b/35166374: don't allow init to make arbitrarily large allocations.
if (len > 0xffff) {
LOG(ERROR) << "sys_prop: RecvString asked to read huge string: " << len;
errno = ENOMEM;
return false;
}
std::vector<char> chars(len);
if (!RecvChars(&chars[0], len, timeout_ms)) {
return false;
}
*value = std::string(&chars[0], len);
return true;
}
bool SendUint32(uint32_t value) {
int result = TEMP_FAILURE_RETRY(send(socket_, &value, sizeof(value), 0));
return result == sizeof(value);
}
int socket() { return socket_; }
const ucred& cred() { return cred_; }
std::string source_context() const {
char* source_context = nullptr;
getpeercon(socket_, &source_context);
std::string result = source_context;
freecon(source_context);
return result;
}
private:
bool PollIn(uint32_t* timeout_ms) {
struct pollfd ufds[1];
ufds[0].fd = socket_;
ufds[0].events = POLLIN;
ufds[0].revents = 0;
while (*timeout_ms > 0) {
auto start_time = std::chrono::steady_clock::now();
int nr = poll(ufds, 1, *timeout_ms);
auto now = std::chrono::steady_clock::now();
auto time_elapsed =
std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
uint64_t millis = time_elapsed.count();
*timeout_ms = (millis > *timeout_ms) ? 0 : *timeout_ms - millis;
if (nr > 0) {
return true;
}
if (nr == 0) {
// Timeout
break;
}
if (nr < 0 && errno != EINTR) {
PLOG(ERROR) << "sys_prop: error waiting for uid " << cred_.uid
<< " to send property message";
return false;
} else { // errno == EINTR
// Timer rounds milliseconds down in case of EINTR we want it to be rounded up
// to avoid slowing init down by causing EINTR with under millisecond timeout.
if (*timeout_ms > 0) {
--(*timeout_ms);
}
}
}
LOG(ERROR) << "sys_prop: timeout waiting for uid " << cred_.uid
<< " to send property message.";
return false;
}
bool RecvFully(void* data_ptr, size_t size, uint32_t* timeout_ms) {
size_t bytes_left = size;
char* data = static_cast<char*>(data_ptr);
while (*timeout_ms > 0 && bytes_left > 0) {
if (!PollIn(timeout_ms)) {
return false;
}
int result = TEMP_FAILURE_RETRY(recv(socket_, data, bytes_left, MSG_DONTWAIT));
if (result <= 0) {
PLOG(ERROR) << "sys_prop: recv error";
return false;
}
bytes_left -= result;
data += result;
}
if (bytes_left != 0) {
LOG(ERROR) << "sys_prop: recv data is not properly obtained.";
}
return bytes_left == 0;
}
int socket_;
ucred cred_;
DISALLOW_IMPLICIT_CONSTRUCTORS(SocketConnection);
};
bool CheckControlPropertyPerms(const std::string& name, const std::string& value,
const std::string& source_context, const ucred& cr) {
// We check the legacy method first but these properties are dontaudit, so we only log an audit
// if the newer method fails as well. We only do this with the legacy ctl. properties.
if (name == "ctl.start" || name == "ctl.stop" || name == "ctl.restart") {
// The legacy permissions model is that ctl. properties have their name ctl.<action> and
// their value is the name of the service to apply that action to. Permissions for these
// actions are based on the service, so we must create a fake name of ctl.<service> to
// check permissions.
auto control_string_legacy = "ctl." + value;
const char* target_context_legacy = nullptr;
const char* type_legacy = nullptr;
property_info_area->GetPropertyInfo(control_string_legacy.c_str(), &target_context_legacy,
&type_legacy);
if (CheckMacPerms(control_string_legacy, target_context_legacy, source_context.c_str(), cr)) {
return true;
}
}
auto control_string_full = name + "$" + value;
const char* target_context_full = nullptr;
const char* type_full = nullptr;
property_info_area->GetPropertyInfo(control_string_full.c_str(), &target_context_full,
&type_full);
return CheckMacPerms(control_string_full, target_context_full, source_context.c_str(), cr);
}
// This returns one of the enum of PROP_SUCCESS or PROP_ERROR*.
uint32_t HandlePropertySet(const std::string& name, const std::string& value,
const std::string& source_context, const ucred& cr, std::string* error) {
if (!IsLegalPropertyName(name)) {
*error = "Illegal property name";
return PROP_ERROR_INVALID_NAME;
}
if (StartsWith(name, "ctl.")) {
if (!CheckControlPropertyPerms(name, value, source_context, cr)) {
*error = StringPrintf("Invalid permissions to perform '%s' on '%s'", name.c_str() + 4,
value.c_str());
return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
}
HandleControlMessage(name.c_str() + 4, value, cr.pid);
return PROP_SUCCESS;
}
const char* target_context = nullptr;
const char* type = nullptr;
property_info_area->GetPropertyInfo(name.c_str(), &target_context, &type);
if (!CheckMacPerms(name, target_context, source_context.c_str(), cr)) {
*error = "SELinux permission check failed";
return PROP_ERROR_PERMISSION_DENIED;
}
if (type == nullptr || !CheckType(type, value)) {
*error = StringPrintf("Property type check failed, value doesn't match expected type '%s'",
(type ?: "(null)"));
return PROP_ERROR_INVALID_VALUE;
}
// sys.powerctl is a special property that is used to make the device reboot. We want to log
// any process that sets this property to be able to accurately blame the cause of a shutdown.
if (name == "sys.powerctl") {
std::string cmdline_path = StringPrintf("proc/%d/cmdline", cr.pid);
std::string process_cmdline;
std::string process_log_string;
if (ReadFileToString(cmdline_path, &process_cmdline)) {
// Since cmdline is null deliminated, .c_str() conveniently gives us just the process
// path.
process_log_string = StringPrintf(" (%s)", process_cmdline.c_str());
}
LOG(INFO) << "Received sys.powerctl='" << value << "' from pid: " << cr.pid
<< process_log_string;
}
if (name == "selinux.restorecon_recursive") {
return PropertySetAsync(name, value, RestoreconRecursiveAsync, error);
}
return PropertySet(name, value, error);
}
static void handle_property_set_fd() {
static constexpr uint32_t kDefaultSocketTimeout = 2000; /* ms */
int s = accept4(property_set_fd, nullptr, nullptr, SOCK_CLOEXEC);
if (s == -1) {
return;
}
ucred cr;
socklen_t cr_size = sizeof(cr);
if (getsockopt(s, SOL_SOCKET, SO_PEERCRED, &cr, &cr_size) < 0) {
close(s);
PLOG(ERROR) << "sys_prop: unable to get SO_PEERCRED";
return;
}
SocketConnection socket(s, cr);
uint32_t timeout_ms = kDefaultSocketTimeout;
uint32_t cmd = 0;
if (!socket.RecvUint32(&cmd, &timeout_ms)) {
PLOG(ERROR) << "sys_prop: error while reading command from the socket";
socket.SendUint32(PROP_ERROR_READ_CMD);
return;
}
switch (cmd) {
case PROP_MSG_SETPROP: {
char prop_name[PROP_NAME_MAX];
char prop_value[PROP_VALUE_MAX];
if (!socket.RecvChars(prop_name, PROP_NAME_MAX, &timeout_ms) ||
!socket.RecvChars(prop_value, PROP_VALUE_MAX, &timeout_ms)) {
PLOG(ERROR) << "sys_prop(PROP_MSG_SETPROP): error while reading name/value from the socket";
return;
}
prop_name[PROP_NAME_MAX-1] = 0;
prop_value[PROP_VALUE_MAX-1] = 0;
const auto& cr = socket.cred();
std::string error;
uint32_t result =
HandlePropertySet(prop_name, prop_value, socket.source_context(), cr, &error);
if (result != PROP_SUCCESS) {
LOG(ERROR) << "Unable to set property '" << prop_name << "' to '" << prop_value
<< "' from uid:" << cr.uid << " gid:" << cr.gid << " pid:" << cr.pid << ": "
<< error;
}
break;
}
case PROP_MSG_SETPROP2: {
std::string name;
std::string value;
if (!socket.RecvString(&name, &timeout_ms) ||
!socket.RecvString(&value, &timeout_ms)) {
PLOG(ERROR) << "sys_prop(PROP_MSG_SETPROP2): error while reading name/value from the socket";
socket.SendUint32(PROP_ERROR_READ_DATA);
return;
}
const auto& cr = socket.cred();
std::string error;
uint32_t result = HandlePropertySet(name, value, socket.source_context(), cr, &error);
if (result != PROP_SUCCESS) {
LOG(ERROR) << "Unable to set property '" << name << "' to '" << value
<< "' from uid:" << cr.uid << " gid:" << cr.gid << " pid:" << cr.pid << ": "
<< error;
}
socket.SendUint32(result);
break;
}
default:
LOG(ERROR) << "sys_prop: invalid command " << cmd;
socket.SendUint32(PROP_ERROR_INVALID_CMD);
break;
}
}
static bool load_properties_from_file(const char *, const char *);
/*
* Filter is used to decide which properties to load: NULL loads all keys,
* "ro.foo.*" is a prefix match, and "ro.foo.bar" is an exact match.
*/
static void LoadProperties(char* data, const char* filter, const char* filename) {
char *key, *value, *eol, *sol, *tmp, *fn;
size_t flen = 0;
const char* context = kInitContext.c_str();
if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_P__) {
for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
if (StartsWith(filename, path_prefix)) {
context = secontext;
}
}
}
if (filter) {
flen = strlen(filter);
}
sol = data;
while ((eol = strchr(sol, '\n'))) {
key = sol;
*eol++ = 0;
sol = eol;
while (isspace(*key)) key++;
if (*key == '#') continue;
tmp = eol - 2;
while ((tmp > key) && isspace(*tmp)) *tmp-- = 0;
if (!strncmp(key, "import ", 7) && flen == 0) {
fn = key + 7;
while (isspace(*fn)) fn++;
key = strchr(fn, ' ');
if (key) {
*key++ = 0;
while (isspace(*key)) key++;
}
load_properties_from_file(fn, key);
} else {
value = strchr(key, '=');
if (!value) continue;
*value++ = 0;
tmp = value - 2;
while ((tmp > key) && isspace(*tmp)) *tmp-- = 0;
while (isspace(*value)) value++;
if (flen > 0) {
if (filter[flen - 1] == '*') {
if (strncmp(key, filter, flen - 1)) continue;
} else {
if (strcmp(key, filter)) continue;
}
}
if (StartsWith(key, "ctl.") || key == "sys.powerctl"s ||
key == "selinux.restorecon_recursive"s) {
LOG(ERROR) << "Ignoring disallowed property '" << key
<< "' with special meaning in prop file '" << filename << "'";
continue;
}
uint32_t result = 0;
ucred cr = {.pid = 1, .uid = 0, .gid = 0};
std::string error;
result = HandlePropertySet(key, value, context, cr, &error);
if (result != PROP_SUCCESS) {
LOG(ERROR) << "Unable to set property '" << key << "' to '" << value
<< "' in property file '" << filename << "': " << error;
}
}
}
}
// Filter is used to decide which properties to load: NULL loads all keys,
// "ro.foo.*" is a prefix match, and "ro.foo.bar" is an exact match.
static bool load_properties_from_file(const char* filename, const char* filter) {
Timer t;
auto file_contents = ReadFile(filename);
if (!file_contents) {
PLOG(WARNING) << "Couldn't load property file '" << filename
<< "': " << file_contents.error();
return false;
}
file_contents->push_back('\n');
LoadProperties(file_contents->data(), filter, filename);
LOG(VERBOSE) << "(Loading properties from " << filename << " took " << t << ".)";
return true;
}
// persist.sys.usb.config values can't be combined on build-time when property
// files are split into each partition.
// So we need to apply the same rule of build/make/tools/post_process_props.py
// on runtime.
static void update_sys_usb_config() {
bool is_debuggable = android::base::GetBoolProperty("ro.debuggable", false);
std::string config = android::base::GetProperty("persist.sys.usb.config", "");
if (config.empty()) {
property_set("persist.sys.usb.config", is_debuggable ? "adb" : "none");
} else if (is_debuggable && config.find("adb") == std::string::npos &&
config.length() + 4 < PROP_VALUE_MAX) {
config.append(",adb");
property_set("persist.sys.usb.config", config);
}
}
static void load_override_properties() {
if (ALLOW_LOCAL_PROP_OVERRIDE) {
load_properties_from_file("/data/local.prop", NULL);
}
}
/* When booting an encrypted system, /data is not mounted when the
* property service is started, so any properties stored there are
* not loaded. Vold triggers init to load these properties once it
* has mounted /data.
*/
void load_persist_props(void) {
// Devices with FDE have load_persist_props called twice; the first time when the temporary
// /data partition is mounted and then again once /data is truly mounted. We do not want to
// read persistent properties from the temporary /data partition or mark persistent properties
// as having been loaded during the first call, so we return in that case.
std::string crypto_state = android::base::GetProperty("ro.crypto.state", "");
std::string crypto_type = android::base::GetProperty("ro.crypto.type", "");
if (crypto_state == "encrypted" && crypto_type == "block") {
static size_t num_calls = 0;
if (++num_calls == 1) return;
}
load_override_properties();
/* Read persistent properties after all default values have been loaded. */
auto persistent_properties = LoadPersistentProperties();
for (const auto& persistent_property_record : persistent_properties.properties()) {
property_set(persistent_property_record.name(), persistent_property_record.value());
}
persistent_properties_loaded = true;
property_set("ro.persistent_properties.ready", "true");
}
// If the ro.product.[brand|device|manufacturer|model|name] properties have not been explicitly
// set, derive them from ro.product.${partition}.* properties
static void property_initialize_ro_product_props() {
const char* RO_PRODUCT_PROPS_PREFIX = "ro.product.";
const char* RO_PRODUCT_PROPS[] = {
"brand", "device", "manufacturer", "model", "name",
};
const char* RO_PRODUCT_PROPS_ALLOWED_SOURCES[] = {
"odm", "product", "product_services", "system", "vendor",
};
const char* RO_PRODUCT_PROPS_DEFAULT_SOURCE_ORDER =
"product,product_services,odm,vendor,system";
const std::string EMPTY = "";
std::string ro_product_props_source_order =
GetProperty("ro.product.property_source_order", EMPTY);
if (!ro_product_props_source_order.empty()) {
// Verify that all specified sources are valid
for (const auto& source : Split(ro_product_props_source_order, ",")) {
// Verify that the specified source is valid
bool is_allowed_source = false;
for (const auto& allowed_source : RO_PRODUCT_PROPS_ALLOWED_SOURCES) {
if (source == allowed_source) {
is_allowed_source = true;
break;
}
}
if (!is_allowed_source) {
LOG(ERROR) << "Found unexpected source in ro.product.property_source_order; "
"using the default property source order";
ro_product_props_source_order = RO_PRODUCT_PROPS_DEFAULT_SOURCE_ORDER;
break;
}
}
} else {
ro_product_props_source_order = RO_PRODUCT_PROPS_DEFAULT_SOURCE_ORDER;
}
for (const auto& ro_product_prop : RO_PRODUCT_PROPS) {
std::string base_prop(RO_PRODUCT_PROPS_PREFIX);
base_prop += ro_product_prop;
std::string base_prop_val = GetProperty(base_prop, EMPTY);
if (!base_prop_val.empty()) {
continue;
}
for (const auto& source : Split(ro_product_props_source_order, ",")) {
std::string target_prop(RO_PRODUCT_PROPS_PREFIX);
target_prop += source;
target_prop += '.';
target_prop += ro_product_prop;
std::string target_prop_val = GetProperty(target_prop, EMPTY);
if (!target_prop_val.empty()) {
LOG(INFO) << "Setting product property " << base_prop << " to '" << target_prop_val
<< "' (from " << target_prop << ")";
std::string error;
uint32_t res = PropertySet(base_prop, target_prop_val, &error);
if (res != PROP_SUCCESS) {
LOG(ERROR) << "Error setting product property " << base_prop << ": err=" << res
<< " (" << error << ")";
}
break;
}
}
}
}
// If the ro.build.fingerprint property has not been set, derive it from constituent pieces
static void property_derive_build_fingerprint() {
std::string build_fingerprint = GetProperty("ro.build.fingerprint", "");
if (!build_fingerprint.empty()) {
return;
}
const std::string UNKNOWN = "unknown";
build_fingerprint = GetProperty("ro.product.brand", UNKNOWN);
build_fingerprint += '/';
build_fingerprint += GetProperty("ro.product.name", UNKNOWN);
build_fingerprint += '/';
build_fingerprint += GetProperty("ro.product.device", UNKNOWN);
build_fingerprint += ':';
build_fingerprint += GetProperty("ro.build.version.release", UNKNOWN);
build_fingerprint += '/';
build_fingerprint += GetProperty("ro.build.id", UNKNOWN);
build_fingerprint += '/';
build_fingerprint += GetProperty("ro.build.version.incremental", UNKNOWN);
build_fingerprint += ':';
build_fingerprint += GetProperty("ro.build.type", UNKNOWN);
build_fingerprint += '/';
build_fingerprint += GetProperty("ro.build.tags", UNKNOWN);
LOG(INFO) << "Setting property 'ro.build.fingerprint' to '" << build_fingerprint << "'";
std::string error;
uint32_t res = PropertySet("ro.build.fingerprint", build_fingerprint, &error);
if (res != PROP_SUCCESS) {
LOG(ERROR) << "Error setting property 'ro.build.fingerprint': err=" << res << " (" << error
<< ")";
}
}
void property_load_boot_defaults() {
// TODO(b/117892318): merge prop.default and build.prop files into one
// TODO(b/122864654): read the prop files from all partitions and then
// resolve the duplication by their origin so that RO and non-RO properties
// have a consistent overriding order.
if (!load_properties_from_file("/system/etc/prop.default", NULL)) {
// Try recovery path
if (!load_properties_from_file("/prop.default", NULL)) {
// Try legacy path
load_properties_from_file("/default.prop", NULL);
}
}
load_properties_from_file("/product/build.prop", NULL);
load_properties_from_file("/product_services/build.prop", NULL);
load_properties_from_file("/odm/default.prop", NULL);
load_properties_from_file("/vendor/default.prop", NULL);
load_properties_from_file("/system/build.prop", NULL);
load_properties_from_file("/odm/build.prop", NULL);
load_properties_from_file("/vendor/build.prop", NULL);
load_properties_from_file("/factory/factory.prop", "ro.*");
property_initialize_ro_product_props();
property_derive_build_fingerprint();
update_sys_usb_config();
}
static int SelinuxAuditCallback(void* data, security_class_t /*cls*/, char* buf, size_t len) {
auto* d = reinterpret_cast<PropertyAuditData*>(data);
if (!d || !d->name || !d->cr) {
LOG(ERROR) << "AuditCallback invoked with null data arguments!";
return 0;
}
snprintf(buf, len, "property=%s pid=%d uid=%d gid=%d", d->name, d->cr->pid, d->cr->uid,
d->cr->gid);
return 0;
}
bool LoadPropertyInfoFromFile(const std::string& filename,
std::vector<PropertyInfoEntry>* property_infos) {
auto file_contents = std::string();
if (!ReadFileToString(filename, &file_contents)) {
PLOG(ERROR) << "Could not read properties from '" << filename << "'";
return false;
}
auto errors = std::vector<std::string>{};
ParsePropertyInfoFile(file_contents, property_infos, &errors);
// Individual parsing errors are reported but do not cause a failed boot, which is what
// returning false would do here.
for (const auto& error : errors) {
LOG(ERROR) << "Could not read line from '" << filename << "': " << error;
}
return true;
}
void CreateSerializedPropertyInfo() {
auto property_infos = std::vector<PropertyInfoEntry>();
if (access("/system/etc/selinux/plat_property_contexts", R_OK) != -1) {
if (!LoadPropertyInfoFromFile("/system/etc/selinux/plat_property_contexts",
&property_infos)) {
return;
}
// Don't check for failure here, so we always have a sane list of properties.
// E.g. In case of recovery, the vendor partition will not have mounted and we
// still need the system / platform properties to function.
if (!LoadPropertyInfoFromFile("/vendor/etc/selinux/vendor_property_contexts",
&property_infos)) {
// Fallback to nonplat_* if vendor_* doesn't exist.
LoadPropertyInfoFromFile("/vendor/etc/selinux/nonplat_property_contexts",
&property_infos);
}
} else {
if (!LoadPropertyInfoFromFile("/plat_property_contexts", &property_infos)) {
return;
}
if (!LoadPropertyInfoFromFile("/vendor_property_contexts", &property_infos)) {
// Fallback to nonplat_* if vendor_* doesn't exist.
LoadPropertyInfoFromFile("/nonplat_property_contexts", &property_infos);
}
}
auto serialized_contexts = std::string();
auto error = std::string();
if (!BuildTrie(property_infos, "u:object_r:default_prop:s0", "string", &serialized_contexts,
&error)) {
LOG(ERROR) << "Unable to serialize property contexts: " << error;
return;
}
constexpr static const char kPropertyInfosPath[] = "/dev/__properties__/property_info";
if (!WriteStringToFile(serialized_contexts, kPropertyInfosPath, 0444, 0, 0, false)) {
PLOG(ERROR) << "Unable to write serialized property infos to file";
}
selinux_android_restorecon(kPropertyInfosPath, 0);
}
void StartPropertyService(Epoll* epoll) {
selinux_callback cb;
cb.func_audit = SelinuxAuditCallback;
selinux_set_callback(SELINUX_CB_AUDIT, cb);
property_set("ro.property_service.version", "2");
property_set_fd = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
false, 0666, 0, 0, nullptr);
if (property_set_fd == -1) {
PLOG(FATAL) << "start_property_service socket creation failed";
}
listen(property_set_fd, 8);
if (auto result = epoll->RegisterHandler(property_set_fd, handle_property_set_fd); !result) {
PLOG(FATAL) << result.error();
}
}
} // namespace init
} // namespace android
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