1 /*
2 american fuzzy lop++ - network proxy server
3 -------------------------------------------
4
5 Originally written by Michal Zalewski
6
7 Forkserver design by Jann Horn <[email protected]>
8
9 Now maintained by Marc Heuse <[email protected]>,
10 Heiko Eißfeldt <[email protected]> and
11 Andrea Fioraldi <[email protected]> and
12 Dominik Maier <[email protected]>
13
14 Copyright 2016, 2017 Google Inc. All rights reserved.
15 Copyright 2019-2024 AFLplusplus Project. All rights reserved.
16
17 Licensed under the Apache License, Version 2.0 (the "License");
18 you may not use this file except in compliance with the License.
19 You may obtain a copy of the License at:
20
21 http://www.apache.org/licenses/LICENSE-2.0
22
23 */
24
25 #define AFL_MAIN
26
27 #include "config.h"
28 #include "types.h"
29 #include "debug.h"
30 #include "alloc-inl.h"
31 #include "hash.h"
32 #include "forkserver.h"
33 #include "sharedmem.h"
34 #include "common.h"
35
36 #include <stdio.h>
37 #include <unistd.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <time.h>
41 #include <errno.h>
42 #include <signal.h>
43 #include <dirent.h>
44 #include <fcntl.h>
45
46 #include <sys/wait.h>
47 #include <sys/time.h>
48 #include <sys/stat.h>
49 #include <sys/types.h>
50 #include <sys/resource.h>
51 #include <netinet/in.h>
52 #include <netinet/ip6.h>
53 #include <arpa/inet.h>
54 #include <sys/mman.h>
55 #ifndef USEMMAP
56 #include <sys/shm.h>
57 #endif
58 #include <sys/socket.h>
59 #include <netdb.h>
60
61 #ifdef USE_DEFLATE
62 #include <libdeflate.h>
63 struct libdeflate_compressor *compressor;
64 struct libdeflate_decompressor *decompressor;
65 #endif
66
67 static u8 *in_file, /* Minimizer input test case */
68 *out_file;
69
70 static u8 *in_data; /* Input data for trimming */
71 static u8 *buf2;
72
73 static s32 in_len;
74 static s32 buf2_len;
75 static u32 map_size = MAP_SIZE;
76
77 static volatile u8 stop_soon; /* Ctrl-C pressed? */
78
79 /* See if any bytes are set in the bitmap. */
80
anything_set(afl_forkserver_t * fsrv)81 static inline u8 anything_set(afl_forkserver_t *fsrv) {
82
83 u32 *ptr = (u32 *)fsrv->trace_bits;
84 u32 i = (map_size >> 2);
85
86 while (i--) {
87
88 if (*(ptr++)) { return 1; }
89
90 }
91
92 return 0;
93
94 }
95
at_exit_handler(void)96 static void at_exit_handler(void) {
97
98 afl_fsrv_killall();
99
100 }
101
102 /* Write output file. */
103
write_to_file(u8 * path,u8 * mem,u32 len)104 static s32 write_to_file(u8 *path, u8 *mem, u32 len) {
105
106 s32 ret;
107
108 unlink(path); /* Ignore errors */
109
110 ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600);
111
112 if (ret < 0) { PFATAL("Unable to create '%s'", path); }
113
114 ck_write(ret, mem, len, path);
115
116 lseek(ret, 0, SEEK_SET);
117
118 return ret;
119
120 }
121
122 /* Execute target application. Returns 0 if the changes are a dud, or
123 1 if they should be kept. */
124
run_target(afl_forkserver_t * fsrv,char ** argv,u8 * mem,u32 len,u8 first_run)125 static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len,
126 u8 first_run) {
127
128 afl_fsrv_write_to_testcase(fsrv, mem, len);
129
130 fsrv_run_result_t ret =
131 afl_fsrv_run_target(fsrv, fsrv->exec_tmout, &stop_soon);
132
133 if (ret == FSRV_RUN_ERROR) { FATAL("Couldn't run child"); }
134
135 if (stop_soon) {
136
137 SAYF(cRST cLRD "\n+++ aborted by user +++\n" cRST);
138 exit(1);
139
140 }
141
142 return ret;
143
144 }
145
146 /* Handle Ctrl-C and the like. */
147
handle_stop_sig(int sig)148 static void handle_stop_sig(int sig) {
149
150 stop_soon = 1;
151 afl_fsrv_killall();
152
153 }
154
155 /* Do basic preparations - persistent fds, filenames, etc. */
156
set_up_environment(afl_forkserver_t * fsrv)157 static void set_up_environment(afl_forkserver_t *fsrv) {
158
159 u8 *x;
160
161 fsrv->dev_null_fd = open("/dev/null", O_RDWR);
162 if (fsrv->dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); }
163
164 if (!out_file) {
165
166 u8 *use_dir = ".";
167
168 if (access(use_dir, R_OK | W_OK | X_OK)) {
169
170 use_dir = get_afl_env("TMPDIR");
171 if (!use_dir) { use_dir = "/tmp"; }
172
173 }
174
175 out_file = alloc_printf("%s/.afl-input-temp-%u", use_dir, getpid());
176 fsrv->out_file = out_file;
177
178 }
179
180 unlink(out_file);
181
182 fsrv->out_fd = open(out_file, O_RDWR | O_CREAT | O_EXCL, 0600);
183
184 if (fsrv->out_fd < 0) { PFATAL("Unable to create '%s'", out_file); }
185
186 /* Set sane defaults... */
187
188 x = get_afl_env("ASAN_OPTIONS");
189
190 if (x) {
191
192 if (!strstr(x, "abort_on_error=1")) {
193
194 FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!");
195
196 }
197
198 if (!getenv("AFL_DEBUG") && !strstr(x, "symbolize=0")) {
199
200 FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!");
201
202 }
203
204 }
205
206 x = get_afl_env("MSAN_OPTIONS");
207
208 if (x) {
209
210 if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) {
211
212 FATAL("Custom MSAN_OPTIONS set without exit_code=" STRINGIFY(
213 MSAN_ERROR) " - please fix!");
214
215 }
216
217 if (!getenv("AFL_DEBUG") && !strstr(x, "symbolize=0")) {
218
219 FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!");
220
221 }
222
223 }
224
225 set_sanitizer_defaults();
226
227 if (get_afl_env("AFL_PRELOAD")) {
228
229 if (fsrv->qemu_mode) {
230
231 /* afl-qemu-trace takes care of converting AFL_PRELOAD. */
232
233 } else {
234
235 setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1);
236 setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1);
237
238 }
239
240 }
241
242 }
243
244 /* Setup signal handlers, duh. */
245
setup_signal_handlers(void)246 static void setup_signal_handlers(void) {
247
248 struct sigaction sa;
249
250 sa.sa_handler = NULL;
251 sa.sa_flags = SA_RESTART;
252 sa.sa_sigaction = NULL;
253
254 sigemptyset(&sa.sa_mask);
255
256 /* Various ways of saying "stop". */
257
258 sa.sa_handler = handle_stop_sig;
259 sigaction(SIGHUP, &sa, NULL);
260 sigaction(SIGINT, &sa, NULL);
261 sigaction(SIGTERM, &sa, NULL);
262
263 }
264
265 /* Display usage hints. */
266
usage(u8 * argv0)267 static void usage(u8 *argv0) {
268
269 SAYF(
270 "\n%s [ options ] -- /path/to/target_app [ ... ]\n\n"
271
272 "Required parameters:\n"
273
274 " -i port - the port to listen for the client to connect to\n\n"
275
276 "Execution control settings:\n"
277
278 " -f file - input file read by the tested program (stdin)\n"
279 " -t msec - timeout for each run (%d ms)\n"
280 " -m megs - memory limit for child process (%d MB)\n"
281 " -Q - use binary-only instrumentation (QEMU mode)\n"
282 " -U - use unicorn-based instrumentation (Unicorn mode)\n"
283 " -W - use qemu-based instrumentation with Wine (Wine "
284 "mode)\n\n"
285
286 "Environment variables used:\n"
287 "TMPDIR: directory to use for temporary input files\n"
288 "ASAN_OPTIONS: custom settings for ASAN\n"
289 " (must contain abort_on_error=1 and symbolize=0)\n"
290 "MSAN_OPTIONS: custom settings for MSAN\n"
291 " (must contain exitcode="STRINGIFY(MSAN_ERROR)" and symbolize=0)\n"
292 "AFL_MAP_SIZE: the shared memory size for that target. must be >= the size\n"
293 " the target was compiled for\n"
294 "AFL_PRELOAD: LD_PRELOAD / DYLD_INSERT_LIBRARIES settings for target\n"
295
296 , argv0, EXEC_TIMEOUT, MEM_LIMIT);
297
298 exit(1);
299
300 }
301
recv_testcase(int s,void ** buf)302 int recv_testcase(int s, void **buf) {
303
304 u32 size;
305 s32 ret;
306 size_t received;
307
308 received = 0;
309 while (received < 4 && (ret = recv(s, &size + received, 4 - received, 0)) > 0)
310 received += ret;
311 if (received != 4) FATAL("did not receive size information");
312 if (size == 0) FATAL("did not receive valid size information");
313 // fprintf(stderr, "received size information of %d\n", size);
314
315 if ((size & 0xff000000) != 0xff000000) {
316
317 *buf = afl_realloc(buf, size);
318 if (unlikely(!*buf)) { PFATAL("Alloc"); }
319 received = 0;
320 // fprintf(stderr, "unCOMPRESS (%u)\n", size);
321 while (received < size &&
322 (ret = recv(s, ((char *)*buf) + received, size - received, 0)) > 0)
323 received += ret;
324
325 } else {
326
327 #ifdef USE_DEFLATE
328 u32 clen;
329 size -= 0xff000000;
330 *buf = afl_realloc(buf, size);
331 if (unlikely(!*buf)) { PFATAL("Alloc"); }
332 received = 0;
333 while (received < 4 &&
334 (ret = recv(s, &clen + received, 4 - received, 0)) > 0)
335 received += ret;
336 if (received != 4) FATAL("did not receive clen1 information");
337 // fprintf(stderr, "received clen information of %d\n", clen);
338 if (clen < 1)
339 FATAL("did not receive valid compressed len information: %u", clen);
340 buf2 = afl_realloc((void **)&buf2, clen);
341 buf2_len = clen;
342 if (unlikely(!buf2)) { PFATAL("Alloc"); }
343 received = 0;
344 while (received < clen &&
345 (ret = recv(s, buf2 + received, clen - received, 0)) > 0)
346 received += ret;
347 if (received != clen) FATAL("did not receive compressed information");
348 if (libdeflate_deflate_decompress(decompressor, buf2, clen, (char *)*buf,
349 size, &received) != LIBDEFLATE_SUCCESS)
350 FATAL("decompression failed");
351 // fprintf(stderr, "DECOMPRESS (%u->%u):\n", clen, received);
352 // for (u32 i = 0; i < clen; i++) fprintf(stderr, "%02x", buf2[i]);
353 // fprintf(stderr, "\n");
354 // for (u32 i = 0; i < received; i++) fprintf(stderr, "%02x",
355 // ((u8*)(*buf))[i]); fprintf(stderr, "\n");
356 #else
357 FATAL("Received compressed data but not compiled with compression support");
358 #endif
359
360 }
361
362 // fprintf(stderr, "receiving testcase %p %p max %u\n", buf, *buf, *max_len);
363 if (received != size)
364 FATAL("did not receive testcase data %lu != %u, %d", received, size, ret);
365 // fprintf(stderr, "received testcase\n");
366 return size;
367
368 }
369
370 /* Main entry point */
371
main(int argc,char ** argv_orig,char ** envp)372 int main(int argc, char **argv_orig, char **envp) {
373
374 s32 opt, s, sock, on = 1, port = -1;
375 u8 mem_limit_given = 0, timeout_given = 0, unicorn_mode = 0, use_wine = 0;
376 char **use_argv;
377 struct sockaddr_in6 serveraddr, clientaddr;
378 int addrlen = sizeof(clientaddr);
379 char str[INET6_ADDRSTRLEN];
380 char **argv = argv_cpy_dup(argc, argv_orig);
381 u8 *send_buf;
382 #ifdef USE_DEFLATE
383 u32 *lenptr;
384 #endif
385
386 afl_forkserver_t fsrv_var = {0};
387 afl_forkserver_t *fsrv = &fsrv_var;
388 afl_fsrv_init(fsrv);
389 map_size = get_map_size();
390 fsrv->map_size = map_size;
391
392 if ((send_buf = malloc(map_size + 4)) == NULL) PFATAL("malloc");
393
394 while ((opt = getopt(argc, argv, "+i:f:m:t:QUWh")) > 0) {
395
396 switch (opt) {
397
398 case 'i':
399
400 if (port > 0) { FATAL("Multiple -i options not supported"); }
401 port = atoi(optarg);
402 if (port < 1 || port > 65535)
403 FATAL("invalid port definition, must be between 1-65535: %s", optarg);
404 break;
405
406 case 'f':
407
408 if (out_file) { FATAL("Multiple -f options not supported"); }
409 fsrv->use_stdin = 0;
410 out_file = optarg;
411 break;
412
413 case 'm': {
414
415 u8 suffix = 'M';
416
417 if (mem_limit_given) { FATAL("Multiple -m options not supported"); }
418 mem_limit_given = 1;
419
420 if (!optarg) { FATAL("Wrong usage of -m"); }
421
422 if (!strcmp(optarg, "none")) {
423
424 fsrv->mem_limit = 0;
425 break;
426
427 }
428
429 if (sscanf(optarg, "%llu%c", &fsrv->mem_limit, &suffix) < 1 ||
430 optarg[0] == '-') {
431
432 FATAL("Bad syntax used for -m");
433
434 }
435
436 switch (suffix) {
437
438 case 'T':
439 fsrv->mem_limit *= 1024 * 1024;
440 break;
441 case 'G':
442 fsrv->mem_limit *= 1024;
443 break;
444 case 'k':
445 fsrv->mem_limit /= 1024;
446 break;
447 case 'M':
448 break;
449
450 default:
451 FATAL("Unsupported suffix or bad syntax for -m");
452
453 }
454
455 if (fsrv->mem_limit < 5) { FATAL("Dangerously low value of -m"); }
456
457 if (sizeof(rlim_t) == 4 && fsrv->mem_limit > 2000) {
458
459 FATAL("Value of -m out of range on 32-bit systems");
460
461 }
462
463 }
464
465 break;
466
467 case 't':
468
469 if (timeout_given) { FATAL("Multiple -t options not supported"); }
470 timeout_given = 1;
471
472 if (!optarg) { FATAL("Wrong usage of -t"); }
473
474 fsrv->exec_tmout = atoi(optarg);
475
476 if (fsrv->exec_tmout < 10 || optarg[0] == '-') {
477
478 FATAL("Dangerously low value of -t");
479
480 }
481
482 break;
483
484 case 'Q':
485
486 if (fsrv->qemu_mode) { FATAL("Multiple -Q options not supported"); }
487 if (!mem_limit_given) { fsrv->mem_limit = MEM_LIMIT_QEMU; }
488
489 fsrv->qemu_mode = 1;
490 break;
491
492 case 'U':
493
494 if (unicorn_mode) { FATAL("Multiple -Q options not supported"); }
495 if (!mem_limit_given) { fsrv->mem_limit = MEM_LIMIT_UNICORN; }
496
497 unicorn_mode = 1;
498 break;
499
500 case 'W': /* Wine+QEMU mode */
501
502 if (use_wine) { FATAL("Multiple -W options not supported"); }
503 fsrv->qemu_mode = 1;
504 use_wine = 1;
505
506 if (!mem_limit_given) { fsrv->mem_limit = 0; }
507
508 break;
509
510 case 'h':
511 usage(argv[0]);
512 return -1;
513 break;
514
515 default:
516 usage(argv[0]);
517
518 }
519
520 }
521
522 if (optind == argc || port < 1) { usage(argv[0]); }
523
524 check_environment_vars(envp);
525
526 sharedmem_t shm = {0};
527 fsrv->trace_bits = afl_shm_init(&shm, map_size, 0);
528
529 in_data = afl_realloc((void **)&in_data, 65536);
530 if (unlikely(!in_data)) { PFATAL("Alloc"); }
531
532 atexit(at_exit_handler);
533 setup_signal_handlers();
534
535 set_up_environment(fsrv);
536
537 fsrv->target_path = find_binary(argv[optind]);
538 detect_file_args(argv + optind, out_file, &fsrv->use_stdin);
539
540 if (fsrv->qemu_mode) {
541
542 if (use_wine) {
543
544 use_argv = get_wine_argv(argv[0], &fsrv->target_path, argc - optind,
545 argv + optind);
546
547 } else {
548
549 use_argv = get_qemu_argv(argv[0], &fsrv->target_path, argc - optind,
550 argv + optind);
551
552 }
553
554 } else {
555
556 use_argv = argv + optind;
557
558 }
559
560 if ((sock = socket(AF_INET6, SOCK_STREAM, 0)) < 0) PFATAL("socket() failed");
561
562 #ifdef SO_REUSEADDR
563 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) < 0) {
564
565 WARNF("setsockopt(SO_REUSEADDR) failed");
566
567 }
568
569 #endif
570
571 #ifdef SO_PRIORITY
572 int priority = 7;
573 if (setsockopt(sock, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority)) <
574 0) {
575
576 priority = 6;
577 if (setsockopt(sock, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority)) <
578 0)
579 WARNF("could not set priority on socket");
580
581 }
582
583 #endif
584
585 memset(&serveraddr, 0, sizeof(serveraddr));
586 serveraddr.sin6_family = AF_INET6;
587 serveraddr.sin6_port = htons(port);
588 serveraddr.sin6_addr = in6addr_any;
589
590 if (bind(sock, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0)
591 PFATAL("bind() failed");
592
593 if (listen(sock, 1) < 0) { PFATAL("listen() failed"); }
594
595 afl_fsrv_start(
596 fsrv, use_argv, &stop_soon,
597 (get_afl_env("AFL_DEBUG_CHILD") || get_afl_env("AFL_DEBUG_CHILD_OUTPUT"))
598 ? 1
599 : 0);
600
601 #ifdef USE_DEFLATE
602 compressor = libdeflate_alloc_compressor(1);
603 decompressor = libdeflate_alloc_decompressor();
604 buf2 = afl_realloc((void **)&buf2, map_size + 16);
605 buf2_len = map_size + 16;
606 if (unlikely(!buf2)) { PFATAL("alloc"); }
607 lenptr = (u32 *)(buf2 + 4);
608 fprintf(stderr, "Compiled with compression support\n");
609 #endif
610
611 fprintf(stderr,
612 "Waiting for incoming connection from afl-network-client on port %d "
613 "...\n",
614 port);
615
616 if ((s = accept(sock, NULL, NULL)) < 0) { PFATAL("accept() failed"); }
617 fprintf(stderr, "Received connection, starting ...\n");
618
619 #ifdef SO_PRIORITY
620 priority = 7;
621 if (setsockopt(s, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority)) < 0) {
622
623 priority = 6;
624 if (setsockopt(s, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority)) < 0)
625 WARNF("could not set priority on socket");
626
627 }
628
629 #endif
630
631 while ((in_len = recv_testcase(s, (void **)&in_data)) > 0) {
632
633 // fprintf(stderr, "received %u\n", in_len);
634 (void)run_target(fsrv, use_argv, in_data, in_len, 1);
635
636 memcpy(send_buf + 4, fsrv->trace_bits, fsrv->map_size);
637
638 #ifdef USE_DEFLATE
639 memcpy(buf2, &fsrv->child_status, 4);
640 *lenptr = (u32)libdeflate_deflate_compress(
641 compressor, send_buf + 4, fsrv->map_size, buf2 + 8, buf2_len - 8);
642 // fprintf(stderr, "COMPRESS (%u->%u): ", fsrv->map_size, *lenptr);
643 // for (u32 i = 0; i < fsrv->map_size; i++) fprintf(stderr, "%02x",
644 // fsrv->trace_bits[i]); fprintf(stderr, "\n");
645 if (send(s, buf2, *lenptr + 8, 0) != 8 + *lenptr)
646 FATAL("could not send data");
647 #else
648 memcpy(send_buf, &fsrv->child_status, 4);
649 if (send(s, send_buf, fsrv->map_size + 4, 0) != 4 + fsrv->map_size)
650 FATAL("could not send data");
651 #endif
652
653 // fprintf(stderr, "sent result\n");
654
655 }
656
657 unlink(out_file);
658 if (out_file) { ck_free(out_file); }
659 out_file = NULL;
660
661 afl_shm_deinit(&shm);
662 afl_fsrv_deinit(fsrv);
663 if (fsrv->target_path) { ck_free(fsrv->target_path); }
664 afl_free(in_data);
665 #if USE_DEFLATE
666 afl_free(buf2);
667 libdeflate_free_compressor(compressor);
668 libdeflate_free_decompressor(decompressor);
669 #endif
670
671 argv_cpy_free(argv);
672
673 exit(0);
674
675 }
676
677