llvm/lib/Fuzzer/FuzzerUtil.cpp
Kostya Serebryany b8a0c0ecb3 [lib/Fuzzer] use sha1sum for the file hash
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237198 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 22:03:34 +00:00

103 lines
2.6 KiB
C++

//===- FuzzerUtil.cpp - Misc utils ----------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Misc utils.
//===----------------------------------------------------------------------===//
#include "FuzzerInternal.h"
#include <iostream>
#include <sys/time.h>
#include <cassert>
#include <cstring>
#include <signal.h>
#include <unistd.h>
namespace fuzzer {
void Print(const Unit &v, const char *PrintAfter) {
for (auto x : v)
std::cerr << "0x" << std::hex << (unsigned) x << std::dec << ",";
std::cerr << PrintAfter;
}
void PrintASCII(const Unit &U, const char *PrintAfter) {
for (auto X : U) {
if (isprint(X))
std::cerr << X;
else
std::cerr << "\\x" << std::hex << (int)(unsigned)X << std::dec;
}
std::cerr << PrintAfter;
}
// Try to compute a SHA1 sum of this Unit using an external 'sha1sum' command.
// We can not use the SHA1 function from openssl directly because
// a) openssl may not be available,
// b) we may be fuzzing openssl itself.
// This is all very sad, suggestions are welcome.
static std::string TrySha1(const Unit &in) {
char TempPath[] = "/tmp/fuzzer-tmp-XXXXXX";
int FD = mkstemp(TempPath);
if (FD < 0) return "";
ssize_t Written = write(FD, in.data(), in.size());
close(FD);
if (static_cast<size_t>(Written) != in.size()) return "";
std::string Cmd = "sha1sum < ";
Cmd += TempPath;
FILE *F = popen(Cmd.c_str(), "r");
if (!F) return "";
char Sha1[41];
fgets(Sha1, sizeof(Sha1), F);
fclose(F);
unlink(TempPath);
return Sha1;
}
std::string Hash(const Unit &in) {
std::string Sha1 = TrySha1(in);
if (!Sha1.empty())
return Sha1;
size_t h1 = 0, h2 = 0;
for (auto x : in) {
h1 += x;
h1 *= 5;
h2 += x;
h2 *= 7;
}
return std::to_string(h1) + std::to_string(h2);
}
static void AlarmHandler(int, siginfo_t *, void *) {
Fuzzer::StaticAlarmCallback();
}
void SetTimer(int Seconds) {
struct itimerval T {{Seconds, 0}, {Seconds, 0}};
std::cerr << "SetTimer " << Seconds << "\n";
int Res = setitimer(ITIMER_REAL, &T, nullptr);
assert(Res == 0);
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_sigaction = AlarmHandler;
Res = sigaction(SIGALRM, &sigact, 0);
assert(Res == 0);
}
int NumberOfCpuCores() {
FILE *F = popen("nproc", "r");
int N = 0;
fscanf(F, "%d", &N);
fclose(F);
return N;
}
} // namespace fuzzer