| /* |
| american fuzzy lop - file format analyzer |
| ----------------------------------------- |
| |
| Written and maintained by Michal Zalewski <lcamtuf@google.com> |
| |
| Copyright 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 nifty utility that grabs an input file and takes a stab at explaining |
| its structure by observing how changes to it affect the execution path. |
| |
| If the output scrolls past the edge of the screen, pipe it to 'less -r'. |
| |
| */ |
| |
| #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 <ctype.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 *in_file, /* Analyzer input test case */ |
| *prog_in, /* Targeted program input file */ |
| *target_path, /* Path to target binary */ |
| *doc_path; /* Path to docs */ |
| |
| static u8 *in_data; /* Input data for analysis */ |
| |
| static u32 in_len, /* Input data length */ |
| orig_cksum, /* Original checksum */ |
| total_execs, /* Total number of execs */ |
| exec_hangs, /* Total number of hangs */ |
| exec_tmout = EXEC_TIMEOUT; /* Exec timeout (ms) */ |
| |
| static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ |
| |
| static s32 shm_id, /* ID of the SHM region */ |
| dev_null_fd = -1; /* FD to /dev/null */ |
| |
| static u8 edges_only, /* Ignore hit counts? */ |
| use_hex_offsets, /* Show hex offsets? */ |
| use_stdin = 1; /* Use stdin for program input? */ |
| |
| static volatile u8 |
| stop_soon, /* Ctrl-C pressed? */ |
| child_timed_out; /* Child timed out? */ |
| |
| |
| /* Constants used for describing byte behavior. */ |
| |
| #define RESP_NONE 0x00 /* Changing byte is a no-op. */ |
| #define RESP_MINOR 0x01 /* Some changes have no effect. */ |
| #define RESP_VARIABLE 0x02 /* Changes produce variable paths. */ |
| #define RESP_FIXED 0x03 /* Changes produce fixed patterns. */ |
| |
| #define RESP_LEN 0x04 /* Potential length field */ |
| #define RESP_CKSUM 0x05 /* Potential checksum */ |
| #define RESP_SUSPECT 0x06 /* Potential "suspect" blob */ |
| |
| |
| /* Classify tuple counts. This is a slow & naive version, but good enough here. */ |
| |
| static u8 count_class_lookup[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) { |
| |
| u32 i = MAP_SIZE; |
| |
| if (edges_only) { |
| |
| while (i--) { |
| if (*mem) *mem = 1; |
| mem++; |
| } |
| |
| } else { |
| |
| while (i--) { |
| *mem = count_class_lookup[*mem]; |
| mem++; |
| } |
| |
| } |
| |
| } |
| |
| |
| /* See if any bytes are set in the bitmap. */ |
| |
| static inline u8 anything_set(void) { |
| |
| u32* ptr = (u32*)trace_bits; |
| u32 i = (MAP_SIZE >> 2); |
| |
| while (i--) if (*(ptr++)) return 1; |
| |
| return 0; |
| |
| } |
| |
| |
| /* Get rid of shared memory and temp files (atexit handler). */ |
| |
| static void remove_shm(void) { |
| |
| unlink(prog_in); /* Ignore errors */ |
| 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"); |
| |
| } |
| |
| |
| /* Read initial file. */ |
| |
| static void read_initial_file(void) { |
| |
| struct stat st; |
| s32 fd = open(in_file, O_RDONLY); |
| |
| if (fd < 0) PFATAL("Unable to open '%s'", in_file); |
| |
| if (fstat(fd, &st) || !st.st_size) |
| FATAL("Zero-sized input file."); |
| |
| if (st.st_size >= TMIN_MAX_FILE) |
| FATAL("Input file is too large (%u MB max)", TMIN_MAX_FILE / 1024 / 1024); |
| |
| in_len = st.st_size; |
| in_data = ck_alloc_nozero(in_len); |
| |
| ck_read(fd, in_data, in_len, in_file); |
| |
| close(fd); |
| |
| OKF("Read %u byte%s from '%s'.", in_len, in_len == 1 ? "" : "s", in_file); |
| |
| } |
| |
| |
| /* Write output file. */ |
| |
| static s32 write_to_file(u8* path, u8* mem, u32 len) { |
| |
| s32 ret; |
| |
| unlink(path); /* Ignore errors */ |
| |
| ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600); |
| |
| if (ret < 0) PFATAL("Unable to create '%s'", path); |
| |
| ck_write(ret, mem, len, path); |
| |
| lseek(ret, 0, SEEK_SET); |
| |
| 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. Returns exec checksum, or 0 if program |
| times out. */ |
| |
| static u32 run_target(char** argv, u8* mem, u32 len, u8 first_run) { |
| |
| static struct itimerval it; |
| int status = 0; |
| |
| s32 prog_in_fd; |
| u32 cksum; |
| |
| memset(trace_bits, 0, MAP_SIZE); |
| MEM_BARRIER(); |
| |
| prog_in_fd = write_to_file(prog_in, mem, len); |
| |
| child_pid = fork(); |
| |
| if (child_pid < 0) PFATAL("fork() failed"); |
| |
| if (!child_pid) { |
| |
| struct rlimit r; |
| |
| if (dup2(use_stdin ? prog_in_fd : dev_null_fd, 0) < 0 || |
| dup2(dev_null_fd, 1) < 0 || |
| dup2(dev_null_fd, 2) < 0) { |
| |
| *(u32*)trace_bits = EXEC_FAIL_SIG; |
| PFATAL("dup2() failed"); |
| |
| } |
| |
| close(dev_null_fd); |
| close(prog_in_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 */ |
| |
| } |
| |
| r.rlim_max = r.rlim_cur = 0; |
| setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ |
| |
| execv(target_path, argv); |
| |
| *(u32*)trace_bits = EXEC_FAIL_SIG; |
| exit(0); |
| |
| } |
| |
| close(prog_in_fd); |
| |
| /* Configure timeout, wait for child, cancel timeout. */ |
| |
| 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); |
| total_execs++; |
| |
| if (stop_soon) { |
| SAYF(cRST cLRD "\n+++ Analysis aborted by user +++\n" cRST); |
| exit(1); |
| } |
| |
| /* Always discard inputs that time out. */ |
| |
| if (child_timed_out) { |
| |
| exec_hangs++; |
| return 0; |
| |
| } |
| |
| cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); |
| |
| /* We don't actually care if the target is crashing or not, |
| except that when it does, the checksum should be different. */ |
| |
| if (WIFSIGNALED(status) || |
| (WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) || |
| (WIFEXITED(status) && WEXITSTATUS(status))) { |
| |
| cksum ^= 0xffffffff; |
| |
| } |
| |
| if (first_run) orig_cksum = cksum; |
| |
| return cksum; |
| |
| } |
| |
| |
| #ifdef USE_COLOR |
| |
| /* Helper function to display a human-readable character. */ |
| |
| static void show_char(u8 val) { |
| |
| switch (val) { |
| |
| case 0 ... 32: |
| case 127 ... 255: SAYF("#%02x", val); break; |
| |
| default: SAYF(" %c ", val); |
| |
| } |
| |
| } |
| |
| |
| /* Show the legend */ |
| |
| static void show_legend(void) { |
| |
| SAYF(" " cLGR bgGRA " 01 " cRST " - no-op block " |
| cBLK bgLGN " 01 " cRST " - suspected length field\n" |
| " " cBRI bgGRA " 01 " cRST " - superficial content " |
| cBLK bgYEL " 01 " cRST " - suspected cksum or magic int\n" |
| " " cBLK bgCYA " 01 " cRST " - critical stream " |
| cBLK bgLRD " 01 " cRST " - suspected checksummed block\n" |
| " " cBLK bgMGN " 01 " cRST " - \"magic value\" section\n\n"); |
| |
| } |
| |
| #endif /* USE_COLOR */ |
| |
| |
| /* Interpret and report a pattern in the input file. */ |
| |
| static void dump_hex(u8* buf, u32 len, u8* b_data) { |
| |
| u32 i; |
| |
| for (i = 0; i < len; i++) { |
| |
| #ifdef USE_COLOR |
| u32 rlen = 1, off; |
| #else |
| u32 rlen = 1; |
| #endif /* ^USE_COLOR */ |
| |
| u8 rtype = b_data[i] & 0x0f; |
| |
| /* Look ahead to determine the length of run. */ |
| |
| while (i + rlen < len && (b_data[i] >> 7) == (b_data[i + rlen] >> 7)) { |
| |
| if (rtype < (b_data[i + rlen] & 0x0f)) rtype = b_data[i + rlen] & 0x0f; |
| rlen++; |
| |
| } |
| |
| /* Try to do some further classification based on length & value. */ |
| |
| if (rtype == RESP_FIXED) { |
| |
| switch (rlen) { |
| |
| case 2: { |
| |
| u16 val = *(u16*)(in_data + i); |
| |
| /* Small integers may be length fields. */ |
| |
| if (val && (val <= in_len || SWAP16(val) <= in_len)) { |
| rtype = RESP_LEN; |
| break; |
| } |
| |
| /* Uniform integers may be checksums. */ |
| |
| if (val && abs(in_data[i] - in_data[i + 1]) > 32) { |
| rtype = RESP_CKSUM; |
| break; |
| } |
| |
| break; |
| |
| } |
| |
| case 4: { |
| |
| u32 val = *(u32*)(in_data + i); |
| |
| /* Small integers may be length fields. */ |
| |
| if (val && (val <= in_len || SWAP32(val) <= in_len)) { |
| rtype = RESP_LEN; |
| break; |
| } |
| |
| /* Uniform integers may be checksums. */ |
| |
| if (val && (in_data[i] >> 7 != in_data[i + 1] >> 7 || |
| in_data[i] >> 7 != in_data[i + 2] >> 7 || |
| in_data[i] >> 7 != in_data[i + 3] >> 7)) { |
| rtype = RESP_CKSUM; |
| break; |
| } |
| |
| break; |
| |
| } |
| |
| case 1: case 3: case 5 ... MAX_AUTO_EXTRA - 1: break; |
| |
| default: rtype = RESP_SUSPECT; |
| |
| } |
| |
| } |
| |
| /* Print out the entire run. */ |
| |
| #ifdef USE_COLOR |
| |
| for (off = 0; off < rlen; off++) { |
| |
| /* Every 16 digits, display offset. */ |
| |
| if (!((i + off) % 16)) { |
| |
| if (off) SAYF(cRST cLCY ">"); |
| |
| if (use_hex_offsets) |
| SAYF(cRST cGRA "%s[%06x] " cRST, (i + off) ? "\n" : "", i + off); |
| else |
| SAYF(cRST cGRA "%s[%06u] " cRST, (i + off) ? "\n" : "", i + off); |
| |
| } |
| |
| switch (rtype) { |
| |
| case RESP_NONE: SAYF(cLGR bgGRA); break; |
| case RESP_MINOR: SAYF(cBRI bgGRA); break; |
| case RESP_VARIABLE: SAYF(cBLK bgCYA); break; |
| case RESP_FIXED: SAYF(cBLK bgMGN); break; |
| case RESP_LEN: SAYF(cBLK bgLGN); break; |
| case RESP_CKSUM: SAYF(cBLK bgYEL); break; |
| case RESP_SUSPECT: SAYF(cBLK bgLRD); break; |
| |
| } |
| |
| show_char(in_data[i + off]); |
| |
| if (off != rlen - 1 && (i + off + 1) % 16) SAYF(" "); else SAYF(cRST " "); |
| |
| } |
| |
| #else |
| |
| if (use_hex_offsets) |
| SAYF(" Offset %x, length %u: ", i, rlen); |
| else |
| SAYF(" Offset %u, length %u: ", i, rlen); |
| |
| switch (rtype) { |
| |
| case RESP_NONE: SAYF("no-op block\n"); break; |
| case RESP_MINOR: SAYF("superficial content\n"); break; |
| case RESP_VARIABLE: SAYF("critical stream\n"); break; |
| case RESP_FIXED: SAYF("\"magic value\" section\n"); break; |
| case RESP_LEN: SAYF("suspected length field\n"); break; |
| case RESP_CKSUM: SAYF("suspected cksum or magic int\n"); break; |
| case RESP_SUSPECT: SAYF("suspected checksummed block\n"); break; |
| |
| } |
| |
| #endif /* ^USE_COLOR */ |
| |
| i += rlen - 1; |
| |
| } |
| |
| #ifdef USE_COLOR |
| SAYF(cRST "\n"); |
| #endif /* USE_COLOR */ |
| |
| } |
| |
| |
| |
| /* Actually analyze! */ |
| |
| static void analyze(char** argv) { |
| |
| u32 i; |
| u32 boring_len = 0, prev_xff = 0, prev_x01 = 0, prev_s10 = 0, prev_a10 = 0; |
| |
| u8* b_data = ck_alloc(in_len + 1); |
| u8 seq_byte = 0; |
| |
| b_data[in_len] = 0xff; /* Intentional terminator. */ |
| |
| ACTF("Analyzing input file (this may take a while)...\n"); |
| |
| #ifdef USE_COLOR |
| show_legend(); |
| #endif /* USE_COLOR */ |
| |
| for (i = 0; i < in_len; i++) { |
| |
| u32 xor_ff, xor_01, sub_10, add_10; |
| u8 xff_orig, x01_orig, s10_orig, a10_orig; |
| |
| /* Perform walking byte adjustments across the file. We perform four |
| operations designed to elicit some response from the underlying |
| code. */ |
| |
| in_data[i] ^= 0xff; |
| xor_ff = run_target(argv, in_data, in_len, 0); |
| |
| in_data[i] ^= 0xfe; |
| xor_01 = run_target(argv, in_data, in_len, 0); |
| |
| in_data[i] = (in_data[i] ^ 0x01) - 0x10; |
| sub_10 = run_target(argv, in_data, in_len, 0); |
| |
| in_data[i] += 0x20; |
| add_10 = run_target(argv, in_data, in_len, 0); |
| in_data[i] -= 0x10; |
| |
| /* Classify current behavior. */ |
| |
| xff_orig = (xor_ff == orig_cksum); |
| x01_orig = (xor_01 == orig_cksum); |
| s10_orig = (sub_10 == orig_cksum); |
| a10_orig = (add_10 == orig_cksum); |
| |
| if (xff_orig && x01_orig && s10_orig && a10_orig) { |
| |
| b_data[i] = RESP_NONE; |
| boring_len++; |
| |
| } else if (xff_orig || x01_orig || s10_orig || a10_orig) { |
| |
| b_data[i] = RESP_MINOR; |
| boring_len++; |
| |
| } else if (xor_ff == xor_01 && xor_ff == sub_10 && xor_ff == add_10) { |
| |
| b_data[i] = RESP_FIXED; |
| |
| } else b_data[i] = RESP_VARIABLE; |
| |
| /* When all checksums change, flip most significant bit of b_data. */ |
| |
| if (prev_xff != xor_ff && prev_x01 != xor_01 && |
| prev_s10 != sub_10 && prev_a10 != add_10) seq_byte ^= 0x80; |
| |
| b_data[i] |= seq_byte; |
| |
| prev_xff = xor_ff; |
| prev_x01 = xor_01; |
| prev_s10 = sub_10; |
| prev_a10 = add_10; |
| |
| } |
| |
| dump_hex(in_data, in_len, b_data); |
| |
| SAYF("\n"); |
| |
| OKF("Analysis complete. Interesting bits: %0.02f%% of the input file.", |
| 100.0 - ((double)boring_len * 100) / in_len); |
| |
| if (exec_hangs) |
| WARNF(cLRD "Encountered %u timeouts - results may be skewed." cRST, |
| exec_hangs); |
| |
| ck_free(b_data); |
| |
| } |
| |
| |
| |
| /* 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) { |
| |
| u8* x; |
| |
| dev_null_fd = open("/dev/null", O_RDWR); |
| if (dev_null_fd < 0) PFATAL("Unable to open /dev/null"); |
| |
| if (!prog_in) { |
| |
| u8* use_dir = "."; |
| |
| if (access(use_dir, R_OK | W_OK | X_OK)) { |
| |
| use_dir = getenv("TMPDIR"); |
| if (!use_dir) use_dir = "/tmp"; |
| |
| } |
| |
| prog_in = alloc_printf("%s/.afl-analyze-temp-%u", use_dir, getpid()); |
| |
| } |
| |
| /* Set sane defaults... */ |
| |
| x = getenv("ASAN_OPTIONS"); |
| |
| if (x) { |
| |
| if (!strstr(x, "abort_on_error=1")) |
| FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!"); |
| |
| if (!strstr(x, "symbolize=0")) |
| FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!"); |
| |
| } |
| |
| x = getenv("MSAN_OPTIONS"); |
| |
| if (x) { |
| |
| if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) |
| FATAL("Custom MSAN_OPTIONS set without exit_code=" |
| STRINGIFY(MSAN_ERROR) " - please fix!"); |
| |
| if (!strstr(x, "symbolize=0")) |
| FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!"); |
| |
| } |
| |
| 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; |
| |
| /* Be sure that we're always using fully-qualified paths. */ |
| |
| if (prog_in[0] == '/') aa_subst = prog_in; |
| else aa_subst = alloc_printf("%s/%s", cwd, prog_in); |
| |
| /* 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 (prog_in[0] != '/') ck_free(aa_subst); |
| |
| } |
| |
| i++; |
| |
| } |
| |
| free(cwd); /* not tracked */ |
| |
| } |
| |
| |
| /* Display usage hints. */ |
| |
| static void usage(u8* argv0) { |
| |
| SAYF("\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" |
| |
| "Required parameters:\n\n" |
| |
| " -i file - input test case to be analyzed by the tool\n" |
| |
| "Execution control settings:\n\n" |
| |
| " -f file - input file read by the tested program (stdin)\n" |
| " -t msec - timeout for each run (%u ms)\n" |
| " -m megs - memory limit for child process (%u MB)\n" |
| " -Q - use binary-only instrumentation (QEMU mode)\n\n" |
| |
| "Analysis settings:\n\n" |
| |
| " -e - look for edge coverage only, ignore hit counts\n\n" |
| |
| "For additional tips, please consult %s/README.\n\n", |
| |
| argv0, EXEC_TIMEOUT, 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); |
| |
| /* Now we need to actually find qemu for argv[0]. */ |
| |
| new_argv[2] = target_path; |
| new_argv[1] = "--"; |
| |
| 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; |
| char** use_argv; |
| |
| doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; |
| |
| SAYF(cCYA "afl-analyze " cBRI VERSION cRST " by <lcamtuf@google.com>\n"); |
| |
| while ((opt = getopt(argc,argv,"+i:f:m:t:eQ")) > 0) |
| |
| switch (opt) { |
| |
| case 'i': |
| |
| if (in_file) FATAL("Multiple -i options not supported"); |
| in_file = optarg; |
| break; |
| |
| case 'f': |
| |
| if (prog_in) FATAL("Multiple -f options not supported"); |
| use_stdin = 0; |
| prog_in = optarg; |
| break; |
| |
| case 'e': |
| |
| if (edges_only) FATAL("Multiple -e options not supported"); |
| edges_only = 1; |
| 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; |
| |
| exec_tmout = atoi(optarg); |
| |
| if (exec_tmout < 10 || optarg[0] == '-') |
| FATAL("Dangerously low value of -t"); |
| |
| 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; |
| |
| default: |
| |
| usage(argv[0]); |
| |
| } |
| |
| if (optind == argc || !in_file) usage(argv[0]); |
| |
| use_hex_offsets = !!getenv("AFL_ANALYZE_HEX"); |
| |
| setup_shm(); |
| setup_signal_handlers(); |
| |
| set_up_environment(); |
| |
| find_binary(argv[optind]); |
| detect_file_args(argv + optind); |
| |
| if (qemu_mode) |
| use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind); |
| else |
| use_argv = argv + optind; |
| |
| SAYF("\n"); |
| |
| read_initial_file(); |
| |
| ACTF("Performing dry run (mem limit = %llu MB, timeout = %u ms%s)...", |
| mem_limit, exec_tmout, edges_only ? ", edges only" : ""); |
| |
| run_target(use_argv, in_data, in_len, 1); |
| |
| if (child_timed_out) |
| FATAL("Target binary times out (adjusting -t may help)."); |
| |
| if (!anything_set()) FATAL("No instrumentation detected."); |
| |
| analyze(use_argv); |
| |
| OKF("We're done here. Have a nice day!\n"); |
| |
| exit(0); |
| |
| } |
| |
