1 //===- FuzzerUtil.cpp - Misc utils ----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 // Misc utils.
9 //===----------------------------------------------------------------------===//
10 
11 #include "FuzzerUtil.h"
12 #include "FuzzerIO.h"
13 #include "FuzzerInternal.h"
14 #include <cassert>
15 #include <chrono>
16 #include <cstring>
17 #include <errno.h>
18 #include <mutex>
19 #include <signal.h>
20 #include <sstream>
21 #include <stdio.h>
22 #include <sys/types.h>
23 #include <thread>
24 
25 namespace fuzzer {
26 
27 void PrintHexArray(const uint8_t *Data, size_t Size,
28                    const char *PrintAfter) {
29   for (size_t i = 0; i < Size; i++)
30     Printf("0x%x,", (unsigned)Data[i]);
31   Printf("%s", PrintAfter);
32 }
33 
34 void Print(const Unit &v, const char *PrintAfter) {
35   PrintHexArray(v.data(), v.size(), PrintAfter);
36 }
37 
38 void PrintASCIIByte(uint8_t Byte) {
39   if (Byte == '\\')
40     Printf("\\\\");
41   else if (Byte == '"')
42     Printf("\\\"");
43   else if (Byte >= 32 && Byte < 127)
44     Printf("%c", Byte);
45   else
46     Printf("\\x%02x", Byte);
47 }
48 
49 void PrintASCII(const uint8_t *Data, size_t Size, const char *PrintAfter) {
50   for (size_t i = 0; i < Size; i++)
51     PrintASCIIByte(Data[i]);
52   Printf("%s", PrintAfter);
53 }
54 
55 void PrintASCII(const Unit &U, const char *PrintAfter) {
56   PrintASCII(U.data(), U.size(), PrintAfter);
57 }
58 
59 bool ToASCII(uint8_t *Data, size_t Size) {
60   bool Changed = false;
61   for (size_t i = 0; i < Size; i++) {
62     uint8_t &X = Data[i];
63     auto NewX = X;
64     NewX &= 127;
65     if (!isspace(NewX) && !isprint(NewX))
66       NewX = ' ';
67     Changed |= NewX != X;
68     X = NewX;
69   }
70   return Changed;
71 }
72 
73 bool IsASCII(const Unit &U) { return IsASCII(U.data(), U.size()); }
74 
75 bool IsASCII(const uint8_t *Data, size_t Size) {
76   for (size_t i = 0; i < Size; i++)
77     if (!(isprint(Data[i]) || isspace(Data[i]))) return false;
78   return true;
79 }
80 
81 bool ParseOneDictionaryEntry(const std::string &Str, Unit *U) {
82   U->clear();
83   if (Str.empty()) return false;
84   size_t L = 0, R = Str.size() - 1;  // We are parsing the range [L,R].
85   // Skip spaces from both sides.
86   while (L < R && isspace(Str[L])) L++;
87   while (R > L && isspace(Str[R])) R--;
88   if (R - L < 2) return false;
89   // Check the closing "
90   if (Str[R] != '"') return false;
91   R--;
92   // Find the opening "
93   while (L < R && Str[L] != '"') L++;
94   if (L >= R) return false;
95   assert(Str[L] == '\"');
96   L++;
97   assert(L <= R);
98   for (size_t Pos = L; Pos <= R; Pos++) {
99     uint8_t V = (uint8_t)Str[Pos];
100     if (!isprint(V) && !isspace(V)) return false;
101     if (V =='\\') {
102       // Handle '\\'
103       if (Pos + 1 <= R && (Str[Pos + 1] == '\\' || Str[Pos + 1] == '"')) {
104         U->push_back(Str[Pos + 1]);
105         Pos++;
106         continue;
107       }
108       // Handle '\xAB'
109       if (Pos + 3 <= R && Str[Pos + 1] == 'x'
110            && isxdigit(Str[Pos + 2]) && isxdigit(Str[Pos + 3])) {
111         char Hex[] = "0xAA";
112         Hex[2] = Str[Pos + 2];
113         Hex[3] = Str[Pos + 3];
114         U->push_back(strtol(Hex, nullptr, 16));
115         Pos += 3;
116         continue;
117       }
118       return false;  // Invalid escape.
119     } else {
120       // Any other character.
121       U->push_back(V);
122     }
123   }
124   return true;
125 }
126 
127 bool ParseDictionaryFile(const std::string &Text, Vector<Unit> *Units) {
128   if (Text.empty()) {
129     Printf("ParseDictionaryFile: file does not exist or is empty\n");
130     return false;
131   }
132   std::istringstream ISS(Text);
133   Units->clear();
134   Unit U;
135   int LineNo = 0;
136   std::string S;
137   while (std::getline(ISS, S, '\n')) {
138     LineNo++;
139     size_t Pos = 0;
140     while (Pos < S.size() && isspace(S[Pos])) Pos++;  // Skip spaces.
141     if (Pos == S.size()) continue;  // Empty line.
142     if (S[Pos] == '#') continue;  // Comment line.
143     if (ParseOneDictionaryEntry(S, &U)) {
144       Units->push_back(U);
145     } else {
146       Printf("ParseDictionaryFile: error in line %d\n\t\t%s\n", LineNo,
147              S.c_str());
148       return false;
149     }
150   }
151   return true;
152 }
153 
154 // Code duplicated (and tested) in llvm/include/llvm/Support/Base64.h
155 std::string Base64(const Unit &U) {
156   static const char Table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
157                               "abcdefghijklmnopqrstuvwxyz"
158                               "0123456789+/";
159   std::string Buffer;
160   Buffer.resize(((U.size() + 2) / 3) * 4);
161 
162   size_t i = 0, j = 0;
163   for (size_t n = U.size() / 3 * 3; i < n; i += 3, j += 4) {
164     uint32_t x = ((unsigned char)U[i] << 16) | ((unsigned char)U[i + 1] << 8) |
165                  (unsigned char)U[i + 2];
166     Buffer[j + 0] = Table[(x >> 18) & 63];
167     Buffer[j + 1] = Table[(x >> 12) & 63];
168     Buffer[j + 2] = Table[(x >> 6) & 63];
169     Buffer[j + 3] = Table[x & 63];
170   }
171   if (i + 1 == U.size()) {
172     uint32_t x = ((unsigned char)U[i] << 16);
173     Buffer[j + 0] = Table[(x >> 18) & 63];
174     Buffer[j + 1] = Table[(x >> 12) & 63];
175     Buffer[j + 2] = '=';
176     Buffer[j + 3] = '=';
177   } else if (i + 2 == U.size()) {
178     uint32_t x = ((unsigned char)U[i] << 16) | ((unsigned char)U[i + 1] << 8);
179     Buffer[j + 0] = Table[(x >> 18) & 63];
180     Buffer[j + 1] = Table[(x >> 12) & 63];
181     Buffer[j + 2] = Table[(x >> 6) & 63];
182     Buffer[j + 3] = '=';
183   }
184   return Buffer;
185 }
186 
187 static std::mutex SymbolizeMutex;
188 
189 std::string DescribePC(const char *SymbolizedFMT, uintptr_t PC) {
190   std::unique_lock<std::mutex> l(SymbolizeMutex, std::try_to_lock);
191   if (!EF->__sanitizer_symbolize_pc || !l.owns_lock())
192     return "<can not symbolize>";
193   char PcDescr[1024] = {};
194   EF->__sanitizer_symbolize_pc(reinterpret_cast<void*>(PC),
195                                SymbolizedFMT, PcDescr, sizeof(PcDescr));
196   PcDescr[sizeof(PcDescr) - 1] = 0;  // Just in case.
197   return PcDescr;
198 }
199 
200 void PrintPC(const char *SymbolizedFMT, const char *FallbackFMT, uintptr_t PC) {
201   if (EF->__sanitizer_symbolize_pc)
202     Printf("%s", DescribePC(SymbolizedFMT, PC).c_str());
203   else
204     Printf(FallbackFMT, PC);
205 }
206 
207 void PrintStackTrace() {
208   std::unique_lock<std::mutex> l(SymbolizeMutex, std::try_to_lock);
209   if (EF->__sanitizer_print_stack_trace && l.owns_lock())
210     EF->__sanitizer_print_stack_trace();
211 }
212 
213 void PrintMemoryProfile() {
214   std::unique_lock<std::mutex> l(SymbolizeMutex, std::try_to_lock);
215   if (EF->__sanitizer_print_memory_profile && l.owns_lock())
216     EF->__sanitizer_print_memory_profile(95, 8);
217 }
218 
219 unsigned NumberOfCpuCores() {
220   unsigned N = std::thread::hardware_concurrency();
221   if (!N) {
222     Printf("WARNING: std::thread::hardware_concurrency not well defined for "
223            "your platform. Assuming CPU count of 1.\n");
224     N = 1;
225   }
226   return N;
227 }
228 
229 size_t SimpleFastHash(const uint8_t *Data, size_t Size) {
230   size_t Res = 0;
231   for (size_t i = 0; i < Size; i++)
232     Res = Res * 11 + Data[i];
233   return Res;
234 }
235 
236 }  // namespace fuzzer
237