blob: ee215c239611a3b2eb46bd74c05bbb05848709f8 [file] [log] [blame]
/**
* Copyright © 2019 IBM Corporation
*
* 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 "log_id.hpp"
#include "paths.hpp"
#include <chrono>
#include <filesystem>
#include <fstream>
#include <phosphor-logging/log.hpp>
namespace openpower
{
namespace pels
{
namespace fs = std::filesystem;
using namespace phosphor::logging;
constexpr uint32_t startingLogID = 1;
constexpr uint32_t bmcLogIDPrefix = 0x50000000;
namespace detail
{
uint32_t addLogIDPrefix(uint32_t id)
{
// If redundant BMCs are ever a thing, may need a different prefix.
return (id & 0x00FFFFFF) | bmcLogIDPrefix;
}
uint32_t getTimeBasedLogID()
{
using namespace std::chrono;
// Use 3 bytes of the nanosecond count since the epoch.
uint32_t id =
duration_cast<nanoseconds>(system_clock::now().time_since_epoch())
.count();
return addLogIDPrefix(id);
}
} // namespace detail
uint32_t generatePELID()
{
// Note: there isn't a need to be thread safe.
static std::string idFilename;
if (idFilename.empty())
{
idFilename = getPELIDFile();
checkFileForZeroData(idFilename);
}
uint32_t id = 0;
if (!fs::exists(idFilename))
{
auto path = fs::path(idFilename).parent_path();
if (!fs::exists(path))
{
fs::create_directories(path);
}
id = startingLogID;
}
else
{
std::ifstream idFile{idFilename};
idFile >> id;
if (idFile.fail())
{
// Just make up an ID
log<level::ERR>("Unable to read PEL ID File!");
return detail::getTimeBasedLogID();
}
}
// Wrapping shouldn't be a problem, but check anyway
if (id == 0x00FFFFFF)
{
id = startingLogID;
}
std::ofstream idFile{idFilename};
idFile << (id + 1);
if (idFile.fail())
{
// Just make up an ID so we don't reuse one next time
log<level::ERR>("Unable to write PEL ID File!");
return detail::getTimeBasedLogID();
}
return detail::addLogIDPrefix(id);
}
void checkFileForZeroData(const std::string& filename)
{
if (fs::exists(filename))
{
char ch;
std::ifstream rf{filename, std::ios::binary};
rf.read(&ch, sizeof(ch));
while (ch == '\0')
{
if (rf.eof())
{
fs::remove(filename);
log<level::WARNING>(
"PEL ID file seems corrupted. Deleting it.");
break;
}
rf.read(&ch, sizeof(ch));
}
}
}
} // namespace pels
} // namespace openpower