| /* |
| american fuzzy lop - map display utility |
| ---------------------------------------- |
| |
| Written and maintained by Michal Zalewski <lcamtuf@google.com> |
| |
| Copyright 2013, 2014, 2015, 2016, 2017 Google Inc. All rights reserved. |
| |
| 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 |
| |
| A very simple tool that runs the targeted binary and displays |
| the contents of the trace bitmap in a human-readable form. Useful in |
| scripts to eliminate redundant inputs and perform other checks. |
| |
| Exit code is 2 if the target program crashes; 1 if it times out or |
| there is a problem executing it; or 0 if execution is successful. |
| |
| */ |
| |
| #define AFL_MAIN |
| |
| #include "config.h" |
| #include "types.h" |
| #include "debug.h" |
| #include "alloc-inl.h" |
| #include "hash.h" |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <time.h> |
| #include <errno.h> |
| #include <signal.h> |
| #include <dirent.h> |
| #include <fcntl.h> |
| |
| #include <sys/wait.h> |
| #include <sys/time.h> |
| #include <sys/shm.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/resource.h> |
| |
| static s32 child_pid; /* PID of the tested program */ |
| |
| static u8* trace_bits; /* SHM with instrumentation bitmap */ |
| |
| static u8 *out_file, /* Trace output file */ |
| *doc_path, /* Path to docs */ |
| *target_path, /* Path to target binary */ |
| *at_file; /* Substitution string for @@ */ |
| |
| static u32 exec_tmout; /* Exec timeout (ms) */ |
| |
| static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ |
| |
| static s32 shm_id; /* ID of the SHM region */ |
| |
| static u8 quiet_mode, /* Hide non-essential messages? */ |
| edges_only, /* Ignore hit counts? */ |
| cmin_mode, /* Generate output in afl-cmin mode? */ |
| binary_mode, /* Write output as a binary map */ |
| keep_cores; /* Allow coredumps? */ |
| |
| static volatile u8 |
| stop_soon, /* Ctrl-C pressed? */ |
| child_timed_out, /* Child timed out? */ |
| child_crashed; /* Child crashed? */ |
| |
| /* Classify tuple counts. Instead of mapping to individual bits, as in |
| afl-fuzz.c, we map to more user-friendly numbers between 1 and 8. */ |
| |
| static const u8 count_class_human[256] = { |
| |
| [0] = 0, |
| [1] = 1, |
| [2] = 2, |
| [3] = 3, |
| [4 ... 7] = 4, |
| [8 ... 15] = 5, |
| [16 ... 31] = 6, |
| [32 ... 127] = 7, |
| [128 ... 255] = 8 |
| |
| }; |
| |
| static const u8 count_class_binary[256] = { |
| |
| [0] = 0, |
| [1] = 1, |
| [2] = 2, |
| [3] = 4, |
| [4 ... 7] = 8, |
| [8 ... 15] = 16, |
| [16 ... 31] = 32, |
| [32 ... 127] = 64, |
| [128 ... 255] = 128 |
| |
| }; |
| |
| static void classify_counts(u8* mem, const u8* map) { |
| |
| u32 i = MAP_SIZE; |
| |
| if (edges_only) { |
| |
| while (i--) { |
| if (*mem) *mem = 1; |
| mem++; |
| } |
| |
| } else { |
| |
| while (i--) { |
| *mem = map[*mem]; |
| mem++; |
| } |
| |
| } |
| |
| } |
| |
| |
| /* Get rid of shared memory (atexit handler). */ |
| |
| static void remove_shm(void) { |
| |
| shmctl(shm_id, IPC_RMID, NULL); |
| |
| } |
| |
| |
| /* Configure shared memory. */ |
| |
| static void setup_shm(void) { |
| |
| u8* shm_str; |
| |
| shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600); |
| |
| if (shm_id < 0) PFATAL("shmget() failed"); |
| |
| atexit(remove_shm); |
| |
| shm_str = alloc_printf("%d", shm_id); |
| |
| setenv(SHM_ENV_VAR, shm_str, 1); |
| |
| ck_free(shm_str); |
| |
| trace_bits = shmat(shm_id, NULL, 0); |
| |
| if (!trace_bits) PFATAL("shmat() failed"); |
| |
| } |
| |
| /* Write results. */ |
| |
| static u32 write_results(void) { |
| |
| s32 fd; |
| u32 i, ret = 0; |
| |
| u8 cco = !!getenv("AFL_CMIN_CRASHES_ONLY"), |
| caa = !!getenv("AFL_CMIN_ALLOW_ANY"); |
| |
| if (!strncmp(out_file, "/dev/", 5)) { |
| |
| fd = open(out_file, O_WRONLY, 0600); |
| if (fd < 0) PFATAL("Unable to open '%s'", out_file); |
| |
| } else if (!strcmp(out_file, "-")) { |
| |
| fd = dup(1); |
| if (fd < 0) PFATAL("Unable to open stdout"); |
| |
| } else { |
| |
| unlink(out_file); /* Ignore errors */ |
| fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600); |
| if (fd < 0) PFATAL("Unable to create '%s'", out_file); |
| |
| } |
| |
| |
| if (binary_mode) { |
| |
| for (i = 0; i < MAP_SIZE; i++) |
| if (trace_bits[i]) ret++; |
| |
| ck_write(fd, trace_bits, MAP_SIZE, out_file); |
| close(fd); |
| |
| } else { |
| |
| FILE* f = fdopen(fd, "w"); |
| |
| if (!f) PFATAL("fdopen() failed"); |
| |
| for (i = 0; i < MAP_SIZE; i++) { |
| |
| if (!trace_bits[i]) continue; |
| ret++; |
| |
| if (cmin_mode) { |
| |
| if (child_timed_out) break; |
| if (!caa && child_crashed != cco) break; |
| |
| fprintf(f, "%u%u\n", trace_bits[i], i); |
| |
| } else fprintf(f, "%06u:%u\n", i, trace_bits[i]); |
| |
| } |
| |
| fclose(f); |
| |
| } |
| |
| return ret; |
| |
| } |
| |
| |
| /* Handle timeout signal. */ |
| |
| static void handle_timeout(int sig) { |
| |
| child_timed_out = 1; |
| if (child_pid > 0) kill(child_pid, SIGKILL); |
| |
| } |
| |
| |
| /* Execute target application. */ |
| |
| static void run_target(char** argv) { |
| |
| static struct itimerval it; |
| int status = 0; |
| |
| if (!quiet_mode) |
| SAYF("-- Program output begins --\n" cRST); |
| |
| MEM_BARRIER(); |
| |
| child_pid = fork(); |
| |
| if (child_pid < 0) PFATAL("fork() failed"); |
| |
| if (!child_pid) { |
| |
| struct rlimit r; |
| |
| if (quiet_mode) { |
| |
| s32 fd = open("/dev/null", O_RDWR); |
| |
| if (fd < 0 || dup2(fd, 1) < 0 || dup2(fd, 2) < 0) { |
| *(u32*)trace_bits = EXEC_FAIL_SIG; |
| PFATAL("Descriptor initialization failed"); |
| } |
| |
| close(fd); |
| |
| } |
| |
| if (mem_limit) { |
| |
| r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; |
| |
| #ifdef RLIMIT_AS |
| |
| setrlimit(RLIMIT_AS, &r); /* Ignore errors */ |
| |
| #else |
| |
| setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ |
| |
| #endif /* ^RLIMIT_AS */ |
| |
| } |
| |
| if (!keep_cores) r.rlim_max = r.rlim_cur = 0; |
| else r.rlim_max = r.rlim_cur = RLIM_INFINITY; |
| |
| setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ |
| |
| if (!getenv("LD_BIND_LAZY")) setenv("LD_BIND_NOW", "1", 0); |
| |
| setsid(); |
| |
| execv(target_path, argv); |
| |
| *(u32*)trace_bits = EXEC_FAIL_SIG; |
| exit(0); |
| |
| } |
| |
| /* Configure timeout, wait for child, cancel timeout. */ |
| |
| if (exec_tmout) { |
| |
| child_timed_out = 0; |
| it.it_value.tv_sec = (exec_tmout / 1000); |
| it.it_value.tv_usec = (exec_tmout % 1000) * 1000; |
| |
| } |
| |
| setitimer(ITIMER_REAL, &it, NULL); |
| |
| if (waitpid(child_pid, &status, 0) <= 0) FATAL("waitpid() failed"); |
| |
| child_pid = 0; |
| it.it_value.tv_sec = 0; |
| it.it_value.tv_usec = 0; |
| setitimer(ITIMER_REAL, &it, NULL); |
| |
| MEM_BARRIER(); |
| |
| /* Clean up bitmap, analyze exit condition, etc. */ |
| |
| if (*(u32*)trace_bits == EXEC_FAIL_SIG) |
| FATAL("Unable to execute '%s'", argv[0]); |
| |
| classify_counts(trace_bits, binary_mode ? |
| count_class_binary : count_class_human); |
| |
| if (!quiet_mode) |
| SAYF(cRST "-- Program output ends --\n"); |
| |
| if (!child_timed_out && !stop_soon && WIFSIGNALED(status)) |
| child_crashed = 1; |
| |
| if (!quiet_mode) { |
| |
| if (child_timed_out) |
| SAYF(cLRD "\n+++ Program timed off +++\n" cRST); |
| else if (stop_soon) |
| SAYF(cLRD "\n+++ Program aborted by user +++\n" cRST); |
| else if (child_crashed) |
| SAYF(cLRD "\n+++ Program killed by signal %u +++\n" cRST, WTERMSIG(status)); |
| |
| } |
| |
| |
| } |
| |
| |
| /* Handle Ctrl-C and the like. */ |
| |
| static void handle_stop_sig(int sig) { |
| |
| stop_soon = 1; |
| |
| if (child_pid > 0) kill(child_pid, SIGKILL); |
| |
| } |
| |
| |
| /* Do basic preparations - persistent fds, filenames, etc. */ |
| |
| static void set_up_environment(void) { |
| |
| setenv("ASAN_OPTIONS", "abort_on_error=1:" |
| "detect_leaks=0:" |
| "symbolize=0:" |
| "allocator_may_return_null=1", 0); |
| |
| setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" |
| "symbolize=0:" |
| "abort_on_error=1:" |
| "allocator_may_return_null=1:" |
| "msan_track_origins=0", 0); |
| |
| if (getenv("AFL_PRELOAD")) { |
| setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); |
| setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); |
| } |
| |
| } |
| |
| |
| /* Setup signal handlers, duh. */ |
| |
| static void setup_signal_handlers(void) { |
| |
| struct sigaction sa; |
| |
| sa.sa_handler = NULL; |
| sa.sa_flags = SA_RESTART; |
| sa.sa_sigaction = NULL; |
| |
| sigemptyset(&sa.sa_mask); |
| |
| /* Various ways of saying "stop". */ |
| |
| sa.sa_handler = handle_stop_sig; |
| sigaction(SIGHUP, &sa, NULL); |
| sigaction(SIGINT, &sa, NULL); |
| sigaction(SIGTERM, &sa, NULL); |
| |
| /* Exec timeout notifications. */ |
| |
| sa.sa_handler = handle_timeout; |
| sigaction(SIGALRM, &sa, NULL); |
| |
| } |
| |
| |
| /* Detect @@ in args. */ |
| |
| static void detect_file_args(char** argv) { |
| |
| u32 i = 0; |
| u8* cwd = getcwd(NULL, 0); |
| |
| if (!cwd) PFATAL("getcwd() failed"); |
| |
| while (argv[i]) { |
| |
| u8* aa_loc = strstr(argv[i], "@@"); |
| |
| if (aa_loc) { |
| |
| u8 *aa_subst, *n_arg; |
| |
| if (!at_file) FATAL("@@ syntax is not supported by this tool."); |
| |
| /* Be sure that we're always using fully-qualified paths. */ |
| |
| if (at_file[0] == '/') aa_subst = at_file; |
| else aa_subst = alloc_printf("%s/%s", cwd, at_file); |
| |
| /* Construct a replacement argv value. */ |
| |
| *aa_loc = 0; |
| n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2); |
| argv[i] = n_arg; |
| *aa_loc = '@'; |
| |
| if (at_file[0] != '/') ck_free(aa_subst); |
| |
| } |
| |
| i++; |
| |
| } |
| |
| free(cwd); /* not tracked */ |
| |
| } |
| |
| |
| /* Show banner. */ |
| |
| static void show_banner(void) { |
| |
| SAYF(cCYA "afl-showmap " cBRI VERSION cRST " by <lcamtuf@google.com>\n"); |
| |
| } |
| |
| /* Display usage hints. */ |
| |
| static void usage(u8* argv0) { |
| |
| show_banner(); |
| |
| SAYF("\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" |
| |
| "Required parameters:\n\n" |
| |
| " -o file - file to write the trace data to\n\n" |
| |
| "Execution control settings:\n\n" |
| |
| " -t msec - timeout for each run (none)\n" |
| " -m megs - memory limit for child process (%u MB)\n" |
| " -Q - use binary-only instrumentation (QEMU mode)\n\n" |
| |
| "Other settings:\n\n" |
| |
| " -q - sink program's output and don't show messages\n" |
| " -e - show edge coverage only, ignore hit counts\n" |
| " -c - allow core dumps\n\n" |
| |
| "This tool displays raw tuple data captured by AFL instrumentation.\n" |
| "For additional help, consult %s/README.\n\n" cRST, |
| |
| argv0, MEM_LIMIT, doc_path); |
| |
| exit(1); |
| |
| } |
| |
| |
| /* Find binary. */ |
| |
| static void find_binary(u8* fname) { |
| |
| u8* env_path = 0; |
| struct stat st; |
| |
| if (strchr(fname, '/') || !(env_path = getenv("PATH"))) { |
| |
| target_path = ck_strdup(fname); |
| |
| if (stat(target_path, &st) || !S_ISREG(st.st_mode) || |
| !(st.st_mode & 0111) || st.st_size < 4) |
| FATAL("Program '%s' not found or not executable", fname); |
| |
| } else { |
| |
| while (env_path) { |
| |
| u8 *cur_elem, *delim = strchr(env_path, ':'); |
| |
| if (delim) { |
| |
| cur_elem = ck_alloc(delim - env_path + 1); |
| memcpy(cur_elem, env_path, delim - env_path); |
| delim++; |
| |
| } else cur_elem = ck_strdup(env_path); |
| |
| env_path = delim; |
| |
| if (cur_elem[0]) |
| target_path = alloc_printf("%s/%s", cur_elem, fname); |
| else |
| target_path = ck_strdup(fname); |
| |
| ck_free(cur_elem); |
| |
| if (!stat(target_path, &st) && S_ISREG(st.st_mode) && |
| (st.st_mode & 0111) && st.st_size >= 4) break; |
| |
| ck_free(target_path); |
| target_path = 0; |
| |
| } |
| |
| if (!target_path) FATAL("Program '%s' not found or not executable", fname); |
| |
| } |
| |
| } |
| |
| |
| /* Fix up argv for QEMU. */ |
| |
| static char** get_qemu_argv(u8* own_loc, char** argv, int argc) { |
| |
| char** new_argv = ck_alloc(sizeof(char*) * (argc + 4)); |
| u8 *tmp, *cp, *rsl, *own_copy; |
| |
| /* Workaround for a QEMU stability glitch. */ |
| |
| setenv("QEMU_LOG", "nochain", 1); |
| |
| memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc); |
| |
| new_argv[2] = target_path; |
| new_argv[1] = "--"; |
| |
| /* Now we need to actually find qemu for argv[0]. */ |
| |
| tmp = getenv("AFL_PATH"); |
| |
| if (tmp) { |
| |
| cp = alloc_printf("%s/afl-qemu-trace", tmp); |
| |
| if (access(cp, X_OK)) |
| FATAL("Unable to find '%s'", tmp); |
| |
| target_path = new_argv[0] = cp; |
| return new_argv; |
| |
| } |
| |
| own_copy = ck_strdup(own_loc); |
| rsl = strrchr(own_copy, '/'); |
| |
| if (rsl) { |
| |
| *rsl = 0; |
| |
| cp = alloc_printf("%s/afl-qemu-trace", own_copy); |
| ck_free(own_copy); |
| |
| if (!access(cp, X_OK)) { |
| |
| target_path = new_argv[0] = cp; |
| return new_argv; |
| |
| } |
| |
| } else ck_free(own_copy); |
| |
| if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { |
| |
| target_path = new_argv[0] = BIN_PATH "/afl-qemu-trace"; |
| return new_argv; |
| |
| } |
| |
| FATAL("Unable to find 'afl-qemu-trace'."); |
| |
| } |
| |
| |
| /* Main entry point */ |
| |
| int main(int argc, char** argv) { |
| |
| s32 opt; |
| u8 mem_limit_given = 0, timeout_given = 0, qemu_mode = 0; |
| u32 tcnt; |
| char** use_argv; |
| |
| doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; |
| |
| while ((opt = getopt(argc,argv,"+o:m:t:A:eqZQbc")) > 0) |
| |
| switch (opt) { |
| |
| case 'o': |
| |
| if (out_file) FATAL("Multiple -o options not supported"); |
| out_file = optarg; |
| break; |
| |
| case 'm': { |
| |
| u8 suffix = 'M'; |
| |
| if (mem_limit_given) FATAL("Multiple -m options not supported"); |
| mem_limit_given = 1; |
| |
| if (!strcmp(optarg, "none")) { |
| |
| mem_limit = 0; |
| break; |
| |
| } |
| |
| if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 || |
| optarg[0] == '-') FATAL("Bad syntax used for -m"); |
| |
| switch (suffix) { |
| |
| case 'T': mem_limit *= 1024 * 1024; break; |
| case 'G': mem_limit *= 1024; break; |
| case 'k': mem_limit /= 1024; break; |
| case 'M': break; |
| |
| default: FATAL("Unsupported suffix or bad syntax for -m"); |
| |
| } |
| |
| if (mem_limit < 5) FATAL("Dangerously low value of -m"); |
| |
| if (sizeof(rlim_t) == 4 && mem_limit > 2000) |
| FATAL("Value of -m out of range on 32-bit systems"); |
| |
| } |
| |
| break; |
| |
| case 't': |
| |
| if (timeout_given) FATAL("Multiple -t options not supported"); |
| timeout_given = 1; |
| |
| if (strcmp(optarg, "none")) { |
| exec_tmout = atoi(optarg); |
| |
| if (exec_tmout < 20 || optarg[0] == '-') |
| FATAL("Dangerously low value of -t"); |
| |
| } |
| |
| break; |
| |
| case 'e': |
| |
| if (edges_only) FATAL("Multiple -e options not supported"); |
| edges_only = 1; |
| break; |
| |
| case 'q': |
| |
| if (quiet_mode) FATAL("Multiple -q options not supported"); |
| quiet_mode = 1; |
| break; |
| |
| case 'Z': |
| |
| /* This is an undocumented option to write data in the syntax expected |
| by afl-cmin. Nobody else should have any use for this. */ |
| |
| cmin_mode = 1; |
| quiet_mode = 1; |
| break; |
| |
| case 'A': |
| |
| /* Another afl-cmin specific feature. */ |
| at_file = optarg; |
| break; |
| |
| case 'Q': |
| |
| if (qemu_mode) FATAL("Multiple -Q options not supported"); |
| if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU; |
| |
| qemu_mode = 1; |
| break; |
| |
| case 'b': |
| |
| /* Secret undocumented mode. Writes output in raw binary format |
| similar to that dumped by afl-fuzz in <out_dir/queue/fuzz_bitmap. */ |
| |
| binary_mode = 1; |
| break; |
| |
| case 'c': |
| |
| if (keep_cores) FATAL("Multiple -c options not supported"); |
| keep_cores = 1; |
| break; |
| |
| default: |
| |
| usage(argv[0]); |
| |
| } |
| |
| if (optind == argc || !out_file) usage(argv[0]); |
| |
| setup_shm(); |
| setup_signal_handlers(); |
| |
| set_up_environment(); |
| |
| find_binary(argv[optind]); |
| |
| if (!quiet_mode) { |
| show_banner(); |
| ACTF("Executing '%s'...\n", target_path); |
| } |
| |
| detect_file_args(argv + optind); |
| |
| if (qemu_mode) |
| use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind); |
| else |
| use_argv = argv + optind; |
| |
| run_target(use_argv); |
| |
| tcnt = write_results(); |
| |
| if (!quiet_mode) { |
| |
| if (!tcnt) FATAL("No instrumentation detected" cRST); |
| OKF("Captured %u tuples in '%s'." cRST, tcnt, out_file); |
| |
| } |
| |
| exit(child_crashed * 2 + child_timed_out); |
| |
| } |
| |
