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/**
* Copyright © 2023 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 "journal.hpp"
#include <phosphor-logging/log.hpp>
#include <stdexcept>
#include <thread>
namespace openpower::pels
{
using namespace phosphor::logging;
/**
* @class JournalCloser
*
* Closes the journal on destruction
*/
class JournalCloser
{
public:
JournalCloser() = delete;
JournalCloser(const JournalCloser&) = delete;
JournalCloser(JournalCloser&&) = delete;
JournalCloser& operator=(const JournalCloser&) = delete;
JournalCloser& operator=(JournalCloser&&) = delete;
explicit JournalCloser(sd_journal* journal) : journal{journal} {}
~JournalCloser()
{
sd_journal_close(journal);
}
private:
sd_journal* journal{nullptr};
};
std::vector<std::string> Journal::getMessages(const std::string& syslogID,
size_t maxMessages) const
{
// The message registry JSON schema will also fail if a zero is in the JSON
if (0 == maxMessages)
{
log<level::ERR>(
"maxMessages value of zero passed into Journal::getMessages");
return std::vector<std::string>{};
}
sd_journal* journal;
int rc = sd_journal_open(&journal, SD_JOURNAL_LOCAL_ONLY);
if (rc < 0)
{
throw std::runtime_error{std::string{"Failed to open journal: "} +
strerror(-rc)};
}
JournalCloser closer{journal};
if (!syslogID.empty())
{
std::string match{"SYSLOG_IDENTIFIER=" + syslogID};
rc = sd_journal_add_match(journal, match.c_str(), 0);
if (rc < 0)
{
throw std::runtime_error{
std::string{"Failed to add journal match: "} + strerror(-rc)};
}
}
// Loop through matching entries from newest to oldest
std::vector<std::string> messages;
messages.reserve(maxMessages);
std::string sID, pid, message, timeStamp, line;
SD_JOURNAL_FOREACH_BACKWARDS(journal)
{
timeStamp = getTimeStamp(journal);
sID = getFieldValue(journal, "SYSLOG_IDENTIFIER");
pid = getFieldValue(journal, "_PID");
message = getFieldValue(journal, "MESSAGE");
line = timeStamp + " " + sID + "[" + pid + "]: " + message;
messages.emplace(messages.begin(), line);
if (messages.size() >= maxMessages)
{
break;
}
}
return messages;
}
std::string Journal::getFieldValue(sd_journal* journal,
const std::string& field) const
{
std::string value{};
const void* data{nullptr};
size_t length{0};
int rc = sd_journal_get_data(journal, field.c_str(), &data, &length);
if (rc < 0)
{
if (-rc == ENOENT)
{
// Current entry does not include this field; return empty value
return value;
}
else
{
throw std::runtime_error{
std::string{"Failed to read journal entry field: "} +
strerror(-rc)};
}
}
// Get value from field data. Field data in format "FIELD=value".
std::string dataString{static_cast<const char*>(data), length};
std::string::size_type pos = dataString.find('=');
if ((pos != std::string::npos) && ((pos + 1) < dataString.size()))
{
// Value is substring after the '='
value = dataString.substr(pos + 1);
}
return value;
}
std::string Journal::getTimeStamp(sd_journal* journal) const
{
// Get realtime (wallclock) timestamp of current journal entry. The
// timestamp is in microseconds since the epoch.
uint64_t usec{0};
int rc = sd_journal_get_realtime_usec(journal, &usec);
if (rc < 0)
{
throw std::runtime_error{
std::string{"Failed to get journal entry timestamp: "} +
strerror(-rc)};
}
// Convert to number of seconds since the epoch
time_t secs = usec / 1000000;
// Convert seconds to tm struct required by strftime()
struct tm* timeStruct = localtime(&secs);
if (timeStruct == nullptr)
{
throw std::runtime_error{
std::string{"Invalid journal entry timestamp: "} + strerror(errno)};
}
// Convert tm struct into a date/time string
char timeStamp[80];
strftime(timeStamp, sizeof(timeStamp), "%b %d %H:%M:%S", timeStruct);
return timeStamp;
}
} // namespace openpower::pels