blob: c4519e3929af5b6dfa64b06d1a160c1015cf4650 [file] [log] [blame]
/*
* Copyright (C) 2018 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 <sys/stat.h>
#include <sys/syscall.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/unique_fd.h>
#include <modprobe/modprobe.h>
std::string Modprobe::GetKernelCmdline(void) {
std::string cmdline;
if (!android::base::ReadFileToString("/proc/cmdline", &cmdline)) {
return "";
}
return cmdline;
}
bool Modprobe::Insmod(const std::string& path_name, const std::string& parameters) {
android::base::unique_fd fd(
TEMP_FAILURE_RETRY(open(path_name.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
if (fd == -1) {
PLOG(ERROR) << "Could not open module '" << path_name << "'";
return false;
}
auto canonical_name = MakeCanonical(path_name);
std::string options = "";
auto options_iter = module_options_.find(canonical_name);
if (options_iter != module_options_.end()) {
options = options_iter->second;
}
if (!parameters.empty()) {
options = options + " " + parameters;
}
LOG(INFO) << "Loading module " << path_name << " with args '" << options << "'";
int ret = syscall(__NR_finit_module, fd.get(), options.c_str(), 0);
if (ret != 0) {
if (errno == EEXIST) {
// Module already loaded
std::lock_guard guard(module_loaded_lock_);
module_loaded_paths_.emplace(path_name);
module_loaded_.emplace(canonical_name);
return true;
}
PLOG(ERROR) << "Failed to insmod '" << path_name << "' with args '" << options << "'";
return false;
}
LOG(INFO) << "Loaded kernel module " << path_name;
std::lock_guard guard(module_loaded_lock_);
module_loaded_paths_.emplace(path_name);
module_loaded_.emplace(canonical_name);
module_count_++;
return true;
}
bool Modprobe::Rmmod(const std::string& module_name) {
auto canonical_name = MakeCanonical(module_name);
int ret = syscall(__NR_delete_module, canonical_name.c_str(), O_NONBLOCK);
if (ret != 0) {
PLOG(ERROR) << "Failed to remove module '" << module_name << "'";
return false;
}
std::lock_guard guard(module_loaded_lock_);
module_loaded_.erase(canonical_name);
return true;
}
bool Modprobe::ModuleExists(const std::string& module_name) {
struct stat fileStat {};
if (blocklist_enabled && module_blocklist_.count(module_name)) {
LOG(INFO) << "module " << module_name << " is blocklisted";
return false;
}
auto deps = GetDependencies(module_name);
if (deps.empty()) {
// missing deps can happen in the case of an alias
return false;
}
if (stat(deps.front().c_str(), &fileStat)) {
PLOG(INFO) << "module " << module_name << " can't be loaded; can't access " << deps.front();
return false;
}
if (!S_ISREG(fileStat.st_mode)) {
LOG(INFO) << "module " << module_name << " is not a regular file";
return false;
}
return true;
}