1 #include "libhfuzz/libhfuzz.h"
2 
3 #include <errno.h>
4 #include <fcntl.h>
5 #include <limits.h>
6 #include <signal.h>
7 #include <stdbool.h>
8 #include <stdint.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <sys/stat.h>
13 #include <sys/types.h>
14 #include <unistd.h>
15 
16 #include "honggfuzz.h"
17 #include "libcommon/common.h"
18 #include "libcommon/files.h"
19 #include "libcommon/log.h"
20 
21 __attribute__((weak)) int LLVMFuzzerTestOneInput(const uint8_t* buf, size_t len);
22 __attribute__((weak)) int LLVMFuzzerInitialize(int* argc UNUSED, char*** argv UNUSED) { return 0; }
23 
24 /* FIXME(robertswiecki): Make it call mangle_Mangle() */
25 __attribute__((weak)) size_t LLVMFuzzerMutate(
26     uint8_t* Data UNUSED, size_t Size UNUSED, size_t MaxSize UNUSED) {
27     LOG_F("LLVMFuzzerMutate() is not supported in honggfuzz yet");
28     return 0;
29 }
30 
31 static uint8_t buf[_HF_PERF_BITMAP_SIZE_16M] = {0};
32 
33 void HF_ITER(const uint8_t** buf_ptr, size_t* len_ptr) {
34     /*
35      * Send the 'done' marker to the parent
36      */
37     static bool initialized = false;
38 
39     if (initialized == true) {
40         static const uint8_t readyTag = 'A';
41         if (files_writeToFd(_HF_PERSISTENT_FD, &readyTag, sizeof(readyTag)) == false) {
42             LOG_F("writeToFd(size=%zu) failed", sizeof(readyTag));
43         }
44     }
45     initialized = true;
46 
47     uint32_t rlen;
48     if (files_readFromFd(_HF_PERSISTENT_FD, (uint8_t*)&rlen, sizeof(rlen)) !=
49         (ssize_t)sizeof(rlen)) {
50         LOG_F("readFromFd(size=%zu) failed", sizeof(rlen));
51     }
52     size_t len = (size_t)rlen;
53     if (len > _HF_PERF_BITMAP_SIZE_16M) {
54         LOG_F("len (%zu) > buf_size (%zu)\n", len, (size_t)_HF_PERF_BITMAP_SIZE_16M);
55     }
56 
57     if (files_readFromFd(_HF_PERSISTENT_FD, buf, len) != (ssize_t)len) {
58         LOG_F("readFromFd(size=%zu) failed", len);
59     }
60 
61     *buf_ptr = buf;
62     *len_ptr = len;
63 }
64 
65 static void runOneInput(const uint8_t* buf, size_t len) {
66     int ret = LLVMFuzzerTestOneInput(buf, len);
67     if (ret != 0) {
68         LOG_F("LLVMFuzzerTestOneInput() returned '%d' instead of '0'", ret);
69     }
70 }
71 
72 /*
73  * Declare it 'weak', so it can be safely linked with regular binaries which
74  * implement their own main()
75  */
76 #if !defined(__CYGWIN__)
77 __attribute__((weak))
78 #endif /* !defined(__CYGWIN__) */
79 int main(int argc, char** argv) {
80     LLVMFuzzerInitialize(&argc, &argv);
81     if (LLVMFuzzerTestOneInput == NULL) {
82         LOG_F(
83             "Define 'int LLVMFuzzerTestOneInput(uint8_t * buf, size_t len)' in your "
84             "code to make it work");
85 
86         extern int hfuzz_module_instrument;
87         extern int hfuzz_module_memorycmp;
88         LOG_F(
89             "This won't be displayed, it's used just to reference other modules in this archive: "
90             "%d",
91             hfuzz_module_instrument + hfuzz_module_memorycmp);
92     }
93 
94     if (fcntl(_HF_PERSISTENT_FD, F_GETFD) == -1 && errno == EBADF) {
95         int in_fd = STDIN_FILENO;
96         const char* fname = "[STDIN]";
97         if (argc > 1) {
98             fname = argv[argc - 1];
99             if ((in_fd = open(argv[argc - 1], O_RDONLY)) == -1) {
100                 PLOG_W("Cannot open '%s' as input, using stdin", argv[argc - 1]);
101                 in_fd = STDIN_FILENO;
102                 fname = "[STDIN]";
103             }
104         }
105 
106         LOG_I(
107             "Accepting input from '%s'\n"
108             "Usage for fuzzing: honggfuzz -P [flags] -- %s",
109             fname, argv[0]);
110 
111         ssize_t len = files_readFromFd(in_fd, buf, sizeof(buf));
112         if (len < 0) {
113             LOG_E("Couldn't read data from stdin: %s", strerror(errno));
114             return -1;
115         }
116 
117         runOneInput(buf, len);
118         return 0;
119     }
120 
121     for (;;) {
122         size_t len;
123         const uint8_t* buf;
124 
125         HF_ITER(&buf, &len);
126         runOneInput(buf, len);
127     }
128 }
129