Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(1338)

Unified Diff: third_party/afl/src/afl-analyze.c

Issue 2075883002: Add American Fuzzy Lop (afl) to third_party/afl/ (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Fix nits Created 4 years, 6 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « third_party/afl/src/README ('k') | third_party/afl/src/afl-as.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: third_party/afl/src/afl-analyze.c
diff --git a/third_party/afl/src/afl-analyze.c b/third_party/afl/src/afl-analyze.c
new file mode 100644
index 0000000000000000000000000000000000000000..2c27a51e185f80be810c38b7d5cec14ea5c1ff95
--- /dev/null
+++ b/third_party/afl/src/afl-analyze.c
@@ -0,0 +1,1065 @@
+/*
+ american fuzzy lop - file format analyzer
+ -----------------------------------------
+
+ Written and maintained by Michal Zalewski <lcamtuf@google.com>
+
+ Copyright 2016 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_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. */
+
+#define AREP4(_sym) (_sym), (_sym), (_sym), (_sym)
+#define AREP8(_sym) AREP4(_sym), AREP4(_sym)
+#define AREP16(_sym) AREP8(_sym), AREP8(_sym)
+#define AREP32(_sym) AREP16(_sym), AREP16(_sym)
+#define AREP64(_sym) AREP32(_sym), AREP32(_sym)
+#define AREP128(_sym) AREP64(_sym), AREP64(_sym)
+
+static u8 count_class_lookup[256] = {
+
+ /* 0 - 3: 4 */ 0, 1, 2, 4,
+ /* 4 - 7: +4 */ AREP4(8),
+ /* 8 - 15: +8 */ AREP8(16),
+ /* 16 - 31: +16 */ AREP16(32),
+ /* 32 - 127: +96 */ AREP64(64), AREP32(64),
+ /* 128+: +128 */ AREP128(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 ">");
+ 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
+
+ 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-tmin-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_LD_PRELOAD"))
+ setenv("LD_PRELOAD", getenv("AFL_LD_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;
+
+ 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]);
+
+ 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);
+
+}
+
« no previous file with comments | « third_party/afl/src/README ('k') | third_party/afl/src/afl-as.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698