136 lines
4.6 KiB
C++
136 lines
4.6 KiB
C++
/*
|
|
* Copyright (C) 2020 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 "VoldNativeServiceValidation.h"
|
|
|
|
#include <android-base/stringprintf.h>
|
|
#include <android-base/strings.h>
|
|
#include <binder/IPCThreadState.h>
|
|
#include <binder/IServiceManager.h>
|
|
#include <private/android_filesystem_config.h>
|
|
|
|
#include <cctype>
|
|
#include <string_view>
|
|
|
|
using android::base::StringPrintf;
|
|
using namespace std::literals;
|
|
|
|
namespace android::vold {
|
|
|
|
binder::Status Ok() {
|
|
return binder::Status::ok();
|
|
}
|
|
|
|
binder::Status Exception(uint32_t code, const std::string& msg) {
|
|
return binder::Status::fromExceptionCode(code, String8(msg.c_str()));
|
|
}
|
|
|
|
binder::Status CheckPermission(const char* permission) {
|
|
int32_t pid;
|
|
int32_t uid;
|
|
|
|
if (checkCallingPermission(String16(permission), &pid, &uid)) {
|
|
return Ok();
|
|
} else {
|
|
return Exception(binder::Status::EX_SECURITY,
|
|
StringPrintf("UID %d / PID %d lacks permission %s", uid, pid, permission));
|
|
}
|
|
}
|
|
|
|
binder::Status CheckUidOrRoot(uid_t expectedUid) {
|
|
uid_t uid = IPCThreadState::self()->getCallingUid();
|
|
if (uid == expectedUid || uid == AID_ROOT) {
|
|
return Ok();
|
|
} else {
|
|
return Exception(binder::Status::EX_SECURITY,
|
|
StringPrintf("UID %d is not expected UID %d", uid, expectedUid));
|
|
}
|
|
}
|
|
|
|
binder::Status CheckArgumentId(const std::string& id) {
|
|
if (id.empty()) {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing ID");
|
|
}
|
|
for (const char& c : id) {
|
|
if (!std::isalnum(c) && c != ':' && c != ',' && c != ';') {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("ID %s is malformed", id.c_str()));
|
|
}
|
|
}
|
|
return Ok();
|
|
}
|
|
|
|
binder::Status CheckArgumentPath(const std::string& path) {
|
|
if (path.empty()) {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing path");
|
|
}
|
|
if (path[0] != '/') {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("Path %s is relative", path.c_str()));
|
|
}
|
|
if (path.find("/../"sv) != path.npos || android::base::EndsWith(path, "/.."sv)) {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("Path %s is shady", path.c_str()));
|
|
}
|
|
for (const char& c : path) {
|
|
if (c == '\0' || c == '\n') {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("Path %s is malformed", path.c_str()));
|
|
}
|
|
}
|
|
return Ok();
|
|
}
|
|
|
|
binder::Status CheckArgumentHex(const std::string& hex) {
|
|
// Empty hex strings are allowed
|
|
for (const char& c : hex) {
|
|
if (!std::isxdigit(c) && c != ':' && c != '-') {
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("Hex %s is malformed", hex.c_str()));
|
|
}
|
|
}
|
|
return Ok();
|
|
}
|
|
|
|
binder::Status CheckIncrementalPath(IncrementalPathKind kind, const std::string& path) {
|
|
if (auto status = CheckArgumentPath(path); !status.isOk()) {
|
|
return status;
|
|
}
|
|
if (kind == IncrementalPathKind::MountSource || kind == IncrementalPathKind::MountTarget ||
|
|
kind == IncrementalPathKind::Any) {
|
|
if (android::base::StartsWith(path, "/data/incremental/MT_")) {
|
|
if (kind != IncrementalPathKind::MountSource &&
|
|
(android::base::EndsWith(path, "/mount") || path.find("/mount/") != path.npos)) {
|
|
return Ok();
|
|
}
|
|
if (kind != IncrementalPathKind::MountTarget &&
|
|
(android::base::EndsWith(path, "/backing_store") ||
|
|
path.find("/backing_store/") != path.npos)) {
|
|
return Ok();
|
|
}
|
|
}
|
|
}
|
|
if (kind == IncrementalPathKind::Bind || kind == IncrementalPathKind::Any) {
|
|
if (android::base::StartsWith(path, "/data/app/")) {
|
|
return Ok();
|
|
}
|
|
}
|
|
return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
|
|
StringPrintf("Path '%s' is not allowed", path.c_str()));
|
|
}
|
|
|
|
} // namespace android::vold
|