AFLplusplus/src/afl-showmap.c
2020-02-18 10:35:27 +01:00

1029 lines
24 KiB
C

/*
american fuzzy lop++ - map display utility
------------------------------------------
Originally written by Michal Zalewski
Forkserver design by Jann Horn <jannhorn@googlemail.com>
Now maintained by Marc Heuse <mh@mh-sec.de>,
Heiko Eißfeldt <heiko.eissfeldt@hexco.de> and
Andrea Fioraldi <andreafioraldi@gmail.com>
Copyright 2016, 2017 Google Inc. All rights reserved.
Copyright 2019-2020 AFLplusplus Project. 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
#ifdef __ANDROID__
#include "android-ashmem.h"
#endif
#include "config.h"
#include "types.h"
#include "debug.h"
#include "alloc-inl.h"
#include "hash.h"
#include "sharedmem.h"
#include "forkserver.h"
#include "common.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>
u8* trace_bits; /* SHM with instrumentation bitmap */
s32 forksrv_pid, /* PID of the fork server */
child_pid; /* PID of the tested program */
s32 fsrv_ctl_fd, /* Fork server control pipe (write) */
fsrv_st_fd; /* Fork server status pipe (read) */
s32 out_fd; /* Persistent fd for stdin_file */
s32 dev_null_fd = -1; /* FD to /dev/null */
s32 out_fd = -1, out_dir_fd = -1, dev_urandom_fd = -1;
FILE* plot_file;
u8 uses_asan;
u8* trace_bits; /* SHM with instrumentation bitmap */
u8 *out_file, /* Trace output file */
*stdin_file, /* stdin file */
*in_dir, /* input folder */
*doc_path, /* Path to docs */
*at_file; /* Substitution string for @@ */
static u8* in_data; /* Input data */
u32 exec_tmout; /* Exec timeout (ms) */
static u32 total, highest; /* tuple content information */
static u32 in_len, /* Input data length */
arg_offset, total_execs; /* Total number of execs */
u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */
u8 quiet_mode, /* Hide non-essential messages? */
edges_only, /* Ignore hit counts? */
raw_instr_output, /* Do not apply AFL filters */
cmin_mode, /* Generate output in afl-cmin mode? */
binary_mode, /* Write output as a binary map */
use_stdin = 1, /* use stdin - unused here */
keep_cores; /* Allow coredumps? */
static volatile u8 stop_soon, /* Ctrl-C pressed? */
child_timed_out, /* Child timed out? */
child_crashed; /* Child crashed? */
static u8 qemu_mode;
/* 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 if (!raw_instr_output) {
while (i--) {
*mem = map[*mem];
mem++;
}
}
}
/* Get rid of temp files (atexit handler). */
static void at_exit_handler(void) {
if (stdin_file) unlink(stdin_file);
}
/* Write results. */
static u32 write_results_to_file(u8* out_file) {
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++;
total += trace_bits[i];
if (highest < trace_bits[i]) highest = trace_bits[i];
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;
}
/* Write results. */
static u32 write_results(void) {
return write_results_to_file(out_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;
}
/* Write modified data to file for testing. If use_stdin is clear, the old file
is unlinked and a new one is created. Otherwise, out_fd is rewound and
truncated. */
static void write_to_testcase(void* mem, u32 len) {
lseek(out_fd, 0, SEEK_SET);
ck_write(out_fd, mem, len, out_file);
if (ftruncate(out_fd, len)) PFATAL("ftruncate() failed");
lseek(out_fd, 0, SEEK_SET);
}
/* Execute target application. Returns 0 if the changes are a dud, or
1 if they should be kept. */
static u8 run_target_forkserver(char** argv, u8* mem, u32 len) {
static struct itimerval it;
static u32 prev_timed_out = 0;
int status = 0;
memset(trace_bits, 0, MAP_SIZE);
MEM_BARRIER();
write_to_testcase(mem, len);
s32 res;
/* we have the fork server up and running, so simply
tell it to have at it, and then read back PID. */
if ((res = write(fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to request new process from fork server (OOM?)");
}
if ((res = read(fsrv_st_fd, &child_pid, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to request new process from fork server (OOM?)");
}
if (child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)");
/* Configure timeout, wait for child, cancel timeout. */
if (exec_tmout) {
it.it_value.tv_sec = (exec_tmout / 1000);
it.it_value.tv_usec = (exec_tmout % 1000) * 1000;
}
setitimer(ITIMER_REAL, &it, NULL);
if ((res = read(fsrv_st_fd, &status, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to communicate with fork server (OOM?)");
}
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);
total_execs++;
if (stop_soon) {
SAYF(cRST cLRD "\n+++ afl-showmap folder mode aborted by user +++\n" cRST);
close(write_to_file(out_file, in_data, in_len));
exit(1);
}
/* Always discard inputs that time out. */
if (child_timed_out) { return 0; }
/* Handle crashing inputs depending on current mode. */
if (WIFSIGNALED(status) ||
(WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) ||
(WIFEXITED(status) && WEXITSTATUS(status))) {
return 0;
}
return 0;
}
/* Read initial file. */
u32 read_file(u8* in_file) {
struct stat st;
s32 fd = open(in_file, O_RDONLY);
if (fd < 0) WARNF("Unable to open '%s'", in_file);
if (fstat(fd, &st) || !st.st_size)
WARNF("Zero-sized input file '%s'.", in_file);
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);
return in_len;
}
/* 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")) {
if (qemu_mode) {
u8* qemu_preload = getenv("QEMU_SET_ENV");
u8* afl_preload = getenv("AFL_PRELOAD");
u8* buf;
s32 i, afl_preload_size = strlen(afl_preload);
for (i = 0; i < afl_preload_size; ++i) {
if (afl_preload[i] == ',')
PFATAL(
"Comma (',') is not allowed in AFL_PRELOAD when -Q is "
"specified!");
}
if (qemu_preload)
buf = alloc_printf("%s,LD_PRELOAD=%s", qemu_preload, afl_preload);
else
buf = alloc_printf("LD_PRELOAD=%s", afl_preload);
setenv("QEMU_SET_ENV", buf, 1);
ck_free(buf);
} else {
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);
}
/* Show banner. */
static void show_banner(void) {
SAYF(cCYA "afl-showmap" VERSION cRST " by Michal Zalewski\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 (%d MB)\n"
" -Q - use binary-only instrumentation (QEMU mode)\n"
" -U - use Unicorn-based instrumentation (Unicorn mode)\n"
" -W - use qemu-based instrumentation with Wine (Wine mode)\n"
" (Not necessary, here for consistency with other afl-* "
"tools)\n\n"
"Other settings:\n\n"
" -i dir - process all files in this directory, -o must be a "
"directory\n"
" and each bitmap will be written there individually.\n"
" -q - sink program's output and don't show messages\n"
" -e - show edge coverage only, ignore hit counts\n"
" -r - show real tuple values instead of AFL filter values\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);
}
}
/* Main entry point */
int main(int argc, char** argv, char** envp) {
s32 opt, i;
u8 mem_limit_given = 0, timeout_given = 0, unicorn_mode = 0, use_wine = 0;
u32 tcnt = 0;
char** use_argv;
doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH;
while ((opt = getopt(argc, argv, "+i:o:f:m:t:A:eqZQUWbcrh")) > 0)
switch (opt) {
case 'i':
if (in_dir) FATAL("Multiple -i options not supported");
in_dir = optarg;
break;
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 'f': // only in here to avoid a compiler warning for use_stdin
use_stdin = 0;
FATAL("Option -f is not supported in afl-showmap");
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");
if (raw_instr_output) FATAL("-e and -r are mutually exclusive");
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 'U':
if (unicorn_mode) FATAL("Multiple -U options not supported");
if (!mem_limit_given) mem_limit = MEM_LIMIT_UNICORN;
unicorn_mode = 1;
break;
case 'W': /* Wine+QEMU mode */
if (use_wine) FATAL("Multiple -W options not supported");
qemu_mode = 1;
use_wine = 1;
if (!mem_limit_given) mem_limit = 0;
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;
case 'r':
if (raw_instr_output) FATAL("Multiple -r options not supported");
if (edges_only) FATAL("-e and -r are mutually exclusive");
raw_instr_output = 1;
break;
case 'h':
usage(argv[0]);
return -1;
break;
default: usage(argv[0]);
}
if (optind == argc || !out_file) usage(argv[0]);
check_environment_vars(envp);
setup_shm(0);
setup_signal_handlers();
set_up_environment();
find_binary(argv[optind]);
if (!quiet_mode) {
show_banner();
ACTF("Executing '%s'...", target_path);
}
if (in_dir) {
if (at_file) PFATAL("Options -A and -i are mutually exclusive");
at_file = "@@";
}
detect_file_args(argv + optind, "");
for (i = optind; i < argc; i++)
if (strcmp(argv[i], "@@") == 0) arg_offset = i;
if (qemu_mode) {
if (use_wine)
use_argv = get_wine_argv(argv[0], argv + optind, argc - optind);
else
use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind);
} else
use_argv = argv + optind;
if (in_dir) {
DIR * dir_in, *dir_out;
struct dirent* dir_ent;
int done = 0;
u8 infile[4096], outfile[4096];
#if !defined(DT_REG)
struct stat statbuf;
#endif
dev_null_fd = open("/dev/null", O_RDWR);
if (dev_null_fd < 0) PFATAL("Unable to open /dev/null");
if (!(dir_in = opendir(in_dir))) PFATAL("cannot open directory %s", in_dir);
if (!(dir_out = opendir(out_file)))
if (mkdir(out_file, 0700))
PFATAL("cannot create output directory %s", out_file);
u8* use_dir = ".";
if (access(use_dir, R_OK | W_OK | X_OK)) {
use_dir = getenv("TMPDIR");
if (!use_dir) use_dir = "/tmp";
}
stdin_file = alloc_printf("%s/.afl-showmap-temp-%u", use_dir, getpid());
unlink(stdin_file);
atexit(at_exit_handler);
out_fd = open(stdin_file, O_RDWR | O_CREAT | O_EXCL, 0600);
if (out_fd < 0) PFATAL("Unable to create '%s'", out_file);
if (arg_offset) argv[arg_offset] = stdin_file;
if (getenv("AFL_DEBUG")) {
int i = optind;
SAYF(cMGN "[D]" cRST " %s:", target_path);
while (argv[i] != NULL)
SAYF(" \"%s\"", argv[i++]);
SAYF("\n");
SAYF(cMGN "[D]" cRST " %d - %d = %d, %s\n", arg_offset, optind,
arg_offset - optind, infile);
}
init_forkserver(use_argv);
while (done == 0 && (dir_ent = readdir(dir_in))) {
if (dir_ent->d_name[0] == '.')
continue; // skip anything that starts with '.'
#if defined(DT_REG) /* Posix and Solaris do not know d_type and DT_REG */
if (dir_ent->d_type != DT_REG) continue; // only regular files
#endif
snprintf(infile, sizeof(infile), "%s/%s", in_dir, dir_ent->d_name);
#if !defined(DT_REG) /* use stat() */
if (-1 == stat(infile, &statbuf) || !S_ISREG(statbuf.st_mode)) continue;
#endif
snprintf(outfile, sizeof(outfile), "%s/%s", out_file, dir_ent->d_name);
if (read_file(infile)) {
run_target_forkserver(use_argv, in_data, in_len);
ck_free(in_data);
tcnt = write_results_to_file(outfile);
}
}
if (!quiet_mode) OKF("Processed %u input files.", total_execs);
} else {
run_target(use_argv);
tcnt = write_results();
}
if (!quiet_mode) {
if (!tcnt) FATAL("No instrumentation detected" cRST);
OKF("Captured %u tuples (highest value %u, total values %u) in '%s'." cRST,
tcnt, highest, total, out_file);
}
if (stdin_file) {
unlink(stdin_file);
stdin_file = NULL;
}
exit(child_crashed * 2 + child_timed_out);
}