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      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