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/*
* Copyright 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 <string>
#include <android-base/logging.h>
#include "../LogReaderList.h"
#include "../LogReaderThread.h"
#include "../LogStatistics.h"
#include "../PruneList.h"
#include "../SerializedLogBuffer.h"
// We don't want to waste a lot of entropy on messages
#define MAX_MSG_LENGTH 5
// Tag IDs usually start at 1000, we only want to try 1000 through 1009
#define MIN_TAG_ID 1000
#define TAG_MOD 10
char* android::uidToName(uid_t) {
return strdup("fake");
}
struct LogInput {
public:
log_id_t log_id;
log_time realtime;
uid_t uid;
pid_t pid;
pid_t tid;
unsigned int log_mask;
};
int write_log_messages(const uint8_t** pdata, size_t* data_left, LogBuffer* log_buffer,
LogStatistics* stats) {
const uint8_t* data = *pdata;
const LogInput* logInput = reinterpret_cast<const LogInput*>(data);
data += sizeof(LogInput);
*data_left -= sizeof(LogInput);
uint32_t tag = MIN_TAG_ID + data[0] % TAG_MOD;
uint8_t msg_length = data[1] % MAX_MSG_LENGTH;
if (msg_length < 2) {
// Not enough data for message
return 0;
}
data += 2 * sizeof(uint8_t);
*data_left -= 2 * sizeof(uint8_t);
if (*data_left < msg_length) {
// Not enough data for tag and message
*pdata = data;
return 0;
}
// We need nullterm'd strings
char msg[sizeof(uint32_t) + MAX_MSG_LENGTH + sizeof(char)];
char* msg_only = msg + sizeof(uint32_t);
memcpy(msg, &tag, sizeof(uint32_t));
memcpy(msg_only, data, msg_length);
msg_only[msg_length] = '\0';
data += msg_length;
*data_left -= msg_length;
// Other elements not in enum.
log_id_t log_id = static_cast<log_id_t>(unsigned(logInput->log_id) % (LOG_ID_MAX + 1));
log_buffer->Log(log_id, logInput->realtime, logInput->uid, logInput->pid, logInput->tid, msg,
sizeof(uint32_t) + msg_length + 1);
stats->Format(logInput->uid, logInput->pid, logInput->log_mask);
*pdata = data;
return 1;
}
class NoopWriter : public LogWriter {
public:
NoopWriter() : LogWriter(0, true) {}
bool Write(const logger_entry&, const char*) override { return true; }
std::string name() const override { return "noop_writer"; }
};
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
// We want a random tag length and a random remaining message length
if (data == nullptr || size < sizeof(LogInput) + 2 * sizeof(uint8_t)) {
return 0;
}
android::base::SetMinimumLogSeverity(android::base::ERROR);
LogReaderList reader_list;
LogTags tags;
PruneList prune_list;
LogStatistics stats(true, true);
std::unique_ptr<LogBuffer> log_buffer;
log_buffer.reset(new SerializedLogBuffer(&reader_list, &tags, &stats));
size_t data_left = size;
const uint8_t** pdata = &data;
prune_list.Init(nullptr);
// We want to get pruning code to get called.
log_id_for_each(i) {
log_buffer->SetSize(i, 10000);
}
while (data_left >= sizeof(LogInput) + 2 * sizeof(uint8_t)) {
if (!write_log_messages(pdata, &data_left, log_buffer.get(), &stats)) {
return 0;
}
}
// Read out all of the logs.
{
auto lock = std::unique_lock{logd_lock};
std::unique_ptr<LogWriter> test_writer(new NoopWriter());
std::unique_ptr<LogReaderThread> log_reader(
new LogReaderThread(log_buffer.get(), &reader_list, std::move(test_writer), true, 0,
kLogMaskAll, 0, {}, 1, {}));
reader_list.AddAndRunThread(std::move(log_reader));
}
// Wait until the reader has finished.
while (true) {
usleep(50);
auto lock = std::unique_lock{logd_lock};
if (reader_list.running_reader_threads().size() == 0) {
break;
}
}
log_id_for_each(i) {
log_buffer->Clear(i, 0);
}
return 0;
}
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