1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969
|
/*
* UDP proxy: emulate an unreliable UDP connection for DTLS testing
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
/*
* Warning: this is an internal utility program we use for tests.
* It does break some abstractions from the NET layer, and is thus NOT an
* example of good general usage.
*/
#include "mbedtls/build_info.h"
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#include <stdlib.h>
#if defined(MBEDTLS_HAVE_TIME)
#include <time.h>
#define mbedtls_time time
#define mbedtls_time_t time_t
#endif
#define mbedtls_printf printf
#define mbedtls_calloc calloc
#define mbedtls_free free
#define mbedtls_exit exit
#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
#endif /* MBEDTLS_PLATFORM_C */
#if !defined(MBEDTLS_NET_C)
int main(void)
{
mbedtls_printf("MBEDTLS_NET_C not defined.\n");
mbedtls_exit(0);
}
#else
#include "mbedtls/net_sockets.h"
#include "mbedtls/error.h"
#include "mbedtls/ssl.h"
#include "mbedtls/timing.h"
#include <string.h>
/* For select() */
#if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
!defined(EFI32)
#if defined(_MSC_VER)
#pragma warning(disable : 5105) // warning inside winbase.h in C11 mode
#endif
#include <winsock2.h>
#include <windows.h>
#if defined(_MSC_VER)
#if defined(_WIN32_WCE)
#pragma comment( lib, "ws2.lib" )
#else
#pragma comment( lib, "ws2_32.lib" )
#endif
#endif /* _MSC_VER */
#else /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
#if defined(MBEDTLS_HAVE_TIME) || (defined(MBEDTLS_TIMING_C) && !defined(MBEDTLS_TIMING_ALT))
#include <sys/time.h>
#endif
#include <sys/select.h>
#include <sys/types.h>
#include <unistd.h>
#endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
#define MAX_MSG_SIZE 16384 + 2048 /* max record/datagram size */
#define DFL_SERVER_ADDR "localhost"
#define DFL_SERVER_PORT "4433"
#define DFL_LISTEN_ADDR "localhost"
#define DFL_LISTEN_PORT "5556"
#define DFL_PACK 0
#if defined(MBEDTLS_TIMING_C)
#define USAGE_PACK \
" pack=%%d default: 0 (don't pack)\n" \
" options: t > 0 (pack for t milliseconds)\n"
#else
#define USAGE_PACK
#endif
#define USAGE \
"\n usage: udp_proxy param=<>...\n" \
"\n acceptable parameters:\n" \
" server_addr=%%s default: localhost\n" \
" server_port=%%d default: 4433\n" \
" listen_addr=%%s default: localhost\n" \
" listen_port=%%d default: 4433\n" \
"\n" \
" duplicate=%%d default: 0 (no duplication)\n" \
" duplicate about 1:N packets randomly\n" \
" delay=%%d default: 0 (no delayed packets)\n" \
" delay about 1:N packets randomly\n" \
" delay_ccs=0/1 default: 0 (don't delay ChangeCipherSpec)\n" \
" delay_cli=%%s Handshake message from client that should be\n" \
" delayed. Possible values are 'ClientHello',\n" \
" 'Certificate', 'CertificateVerify', and\n" \
" 'ClientKeyExchange'.\n" \
" May be used multiple times, even for the same\n" \
" message, in which case the respective message\n" \
" gets delayed multiple times.\n" \
" delay_srv=%%s Handshake message from server that should be\n" \
" delayed. Possible values are 'HelloRequest',\n" \
" 'ServerHello', 'ServerHelloDone', 'Certificate'\n" \
" 'ServerKeyExchange', 'NewSessionTicket',\n" \
" 'HelloVerifyRequest' and ''CertificateRequest'.\n" \
" May be used multiple times, even for the same\n" \
" message, in which case the respective message\n" \
" gets delayed multiple times.\n" \
" drop=%%d default: 0 (no dropped packets)\n" \
" drop about 1:N packets randomly\n" \
" mtu=%%d default: 0 (unlimited)\n" \
" drop packets larger than N bytes\n" \
" bad_ad=0/1 default: 0 (don't add bad ApplicationData)\n" \
" bad_cid=%%d default: 0 (don't corrupt Connection IDs)\n" \
" duplicate 1:N packets containing a CID,\n" \
" modifying CID in first instance of the packet.\n" \
" protect_hvr=0/1 default: 0 (don't protect HelloVerifyRequest)\n" \
" protect_len=%%d default: (don't protect packets of this size)\n" \
" inject_clihlo=0/1 default: 0 (don't inject fake ClientHello)\n" \
"\n" \
" seed=%%d default: (use current time)\n" \
USAGE_PACK \
"\n"
/*
* global options
*/
#define MAX_DELAYED_HS 10
static struct options {
const char *server_addr; /* address to forward packets to */
const char *server_port; /* port to forward packets to */
const char *listen_addr; /* address for accepting client connections */
const char *listen_port; /* port for accepting client connections */
int duplicate; /* duplicate 1 in N packets (none if 0) */
int delay; /* delay 1 packet in N (none if 0) */
int delay_ccs; /* delay ChangeCipherSpec */
char *delay_cli[MAX_DELAYED_HS]; /* handshake types of messages from
* client that should be delayed. */
uint8_t delay_cli_cnt; /* Number of entries in delay_cli. */
char *delay_srv[MAX_DELAYED_HS]; /* handshake types of messages from
* server that should be delayed. */
uint8_t delay_srv_cnt; /* Number of entries in delay_srv. */
int drop; /* drop 1 packet in N (none if 0) */
int mtu; /* drop packets larger than this */
int bad_ad; /* inject corrupted ApplicationData record */
unsigned bad_cid; /* inject corrupted CID record */
int protect_hvr; /* never drop or delay HelloVerifyRequest */
int protect_len; /* never drop/delay packet of the given size*/
int inject_clihlo; /* inject fake ClientHello after handshake */
unsigned pack; /* merge packets into single datagram for
* at most \c merge milliseconds if > 0 */
unsigned int seed; /* seed for "random" events */
} opt;
static void exit_usage(const char *name, const char *value)
{
if (value == NULL) {
mbedtls_printf(" unknown option or missing value: %s\n", name);
} else {
mbedtls_printf(" option %s: illegal value: %s\n", name, value);
}
mbedtls_printf(USAGE);
mbedtls_exit(1);
}
static void get_options(int argc, char *argv[])
{
int i;
char *p, *q;
opt.server_addr = DFL_SERVER_ADDR;
opt.server_port = DFL_SERVER_PORT;
opt.listen_addr = DFL_LISTEN_ADDR;
opt.listen_port = DFL_LISTEN_PORT;
opt.pack = DFL_PACK;
/* Other members default to 0 */
opt.delay_cli_cnt = 0;
opt.delay_srv_cnt = 0;
memset(opt.delay_cli, 0, sizeof(opt.delay_cli));
memset(opt.delay_srv, 0, sizeof(opt.delay_srv));
for (i = 1; i < argc; i++) {
p = argv[i];
if ((q = strchr(p, '=')) == NULL) {
exit_usage(p, NULL);
}
*q++ = '\0';
if (strcmp(p, "server_addr") == 0) {
opt.server_addr = q;
} else if (strcmp(p, "server_port") == 0) {
opt.server_port = q;
} else if (strcmp(p, "listen_addr") == 0) {
opt.listen_addr = q;
} else if (strcmp(p, "listen_port") == 0) {
opt.listen_port = q;
} else if (strcmp(p, "duplicate") == 0) {
opt.duplicate = atoi(q);
if (opt.duplicate < 0 || opt.duplicate > 20) {
exit_usage(p, q);
}
} else if (strcmp(p, "delay") == 0) {
opt.delay = atoi(q);
if (opt.delay < 0 || opt.delay > 20 || opt.delay == 1) {
exit_usage(p, q);
}
} else if (strcmp(p, "delay_ccs") == 0) {
opt.delay_ccs = atoi(q);
if (opt.delay_ccs < 0 || opt.delay_ccs > 1) {
exit_usage(p, q);
}
} else if (strcmp(p, "delay_cli") == 0 ||
strcmp(p, "delay_srv") == 0) {
uint8_t *delay_cnt;
char **delay_list;
size_t len;
char *buf;
if (strcmp(p, "delay_cli") == 0) {
delay_cnt = &opt.delay_cli_cnt;
delay_list = opt.delay_cli;
} else {
delay_cnt = &opt.delay_srv_cnt;
delay_list = opt.delay_srv;
}
if (*delay_cnt == MAX_DELAYED_HS) {
mbedtls_printf(" too many uses of %s: only %d allowed\n",
p, MAX_DELAYED_HS);
exit_usage(p, NULL);
}
len = strlen(q);
buf = mbedtls_calloc(1, len + 1);
if (buf == NULL) {
mbedtls_printf(" Allocation failure\n");
exit(1);
}
memcpy(buf, q, len + 1);
delay_list[(*delay_cnt)++] = buf;
} else if (strcmp(p, "drop") == 0) {
opt.drop = atoi(q);
if (opt.drop < 0 || opt.drop > 20 || opt.drop == 1) {
exit_usage(p, q);
}
} else if (strcmp(p, "pack") == 0) {
#if defined(MBEDTLS_TIMING_C)
opt.pack = (unsigned) atoi(q);
#else
mbedtls_printf(" option pack only defined if MBEDTLS_TIMING_C is enabled\n");
exit(1);
#endif
} else if (strcmp(p, "mtu") == 0) {
opt.mtu = atoi(q);
if (opt.mtu < 0 || opt.mtu > MAX_MSG_SIZE) {
exit_usage(p, q);
}
} else if (strcmp(p, "bad_ad") == 0) {
opt.bad_ad = atoi(q);
if (opt.bad_ad < 0 || opt.bad_ad > 1) {
exit_usage(p, q);
}
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
else if (strcmp(p, "bad_cid") == 0) {
opt.bad_cid = (unsigned) atoi(q);
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
else if (strcmp(p, "protect_hvr") == 0) {
opt.protect_hvr = atoi(q);
if (opt.protect_hvr < 0 || opt.protect_hvr > 1) {
exit_usage(p, q);
}
} else if (strcmp(p, "protect_len") == 0) {
opt.protect_len = atoi(q);
if (opt.protect_len < 0) {
exit_usage(p, q);
}
} else if (strcmp(p, "inject_clihlo") == 0) {
opt.inject_clihlo = atoi(q);
if (opt.inject_clihlo < 0 || opt.inject_clihlo > 1) {
exit_usage(p, q);
}
} else if (strcmp(p, "seed") == 0) {
opt.seed = atoi(q);
if (opt.seed == 0) {
exit_usage(p, q);
}
} else {
exit_usage(p, NULL);
}
}
}
static const char *msg_type(unsigned char *msg, size_t len)
{
if (len < 1) {
return "Invalid";
}
switch (msg[0]) {
case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC: return "ChangeCipherSpec";
case MBEDTLS_SSL_MSG_ALERT: return "Alert";
case MBEDTLS_SSL_MSG_APPLICATION_DATA: return "ApplicationData";
case MBEDTLS_SSL_MSG_CID: return "CID";
case MBEDTLS_SSL_MSG_HANDSHAKE: break; /* See below */
default: return "Unknown";
}
if (len < 13 + 12) {
return "Invalid handshake";
}
/*
* Our handshake message are less than 2^16 bytes long, so they should
* have 0 as the first byte of length, frag_offset and frag_length.
* Otherwise, assume they are encrypted.
*/
if (msg[14] || msg[19] || msg[22]) {
return "Encrypted handshake";
}
switch (msg[13]) {
case MBEDTLS_SSL_HS_HELLO_REQUEST: return "HelloRequest";
case MBEDTLS_SSL_HS_CLIENT_HELLO: return "ClientHello";
case MBEDTLS_SSL_HS_SERVER_HELLO: return "ServerHello";
case MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST: return "HelloVerifyRequest";
case MBEDTLS_SSL_HS_NEW_SESSION_TICKET: return "NewSessionTicket";
case MBEDTLS_SSL_HS_CERTIFICATE: return "Certificate";
case MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE: return "ServerKeyExchange";
case MBEDTLS_SSL_HS_CERTIFICATE_REQUEST: return "CertificateRequest";
case MBEDTLS_SSL_HS_SERVER_HELLO_DONE: return "ServerHelloDone";
case MBEDTLS_SSL_HS_CERTIFICATE_VERIFY: return "CertificateVerify";
case MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE: return "ClientKeyExchange";
case MBEDTLS_SSL_HS_FINISHED: return "Finished";
default: return "Unknown handshake";
}
}
#if defined(MBEDTLS_TIMING_C)
/* Return elapsed time in milliseconds since the first call */
static unsigned elapsed_time(void)
{
static int initialized = 0;
static struct mbedtls_timing_hr_time hires;
if (initialized == 0) {
(void) mbedtls_timing_get_timer(&hires, 1);
initialized = 1;
return 0;
}
return mbedtls_timing_get_timer(&hires, 0);
}
typedef struct {
mbedtls_net_context *ctx;
const char *description;
unsigned packet_lifetime;
unsigned num_datagrams;
unsigned char data[MAX_MSG_SIZE];
size_t len;
} ctx_buffer;
static ctx_buffer outbuf[2];
static int ctx_buffer_flush(ctx_buffer *buf)
{
int ret;
mbedtls_printf(" %05u flush %s: %u bytes, %u datagrams, last %u ms\n",
elapsed_time(), buf->description,
(unsigned) buf->len, buf->num_datagrams,
elapsed_time() - buf->packet_lifetime);
ret = mbedtls_net_send(buf->ctx, buf->data, buf->len);
buf->len = 0;
buf->num_datagrams = 0;
return ret;
}
static unsigned ctx_buffer_time_remaining(ctx_buffer *buf)
{
unsigned const cur_time = elapsed_time();
if (buf->num_datagrams == 0) {
return (unsigned) -1;
}
if (cur_time - buf->packet_lifetime >= opt.pack) {
return 0;
}
return opt.pack - (cur_time - buf->packet_lifetime);
}
static int ctx_buffer_append(ctx_buffer *buf,
const unsigned char *data,
size_t len)
{
int ret;
if (len > (size_t) INT_MAX) {
return -1;
}
if (len > sizeof(buf->data)) {
mbedtls_printf(" ! buffer size %u too large (max %u)\n",
(unsigned) len, (unsigned) sizeof(buf->data));
return -1;
}
if (sizeof(buf->data) - buf->len < len) {
if ((ret = ctx_buffer_flush(buf)) <= 0) {
mbedtls_printf("ctx_buffer_flush failed with -%#04x", (unsigned int) -ret);
return ret;
}
}
memcpy(buf->data + buf->len, data, len);
buf->len += len;
if (++buf->num_datagrams == 1) {
buf->packet_lifetime = elapsed_time();
}
return (int) len;
}
#endif /* MBEDTLS_TIMING_C */
static int dispatch_data(mbedtls_net_context *ctx,
const unsigned char *data,
size_t len)
{
int ret;
#if defined(MBEDTLS_TIMING_C)
ctx_buffer *buf = NULL;
if (opt.pack > 0) {
if (outbuf[0].ctx == ctx) {
buf = &outbuf[0];
} else if (outbuf[1].ctx == ctx) {
buf = &outbuf[1];
}
if (buf == NULL) {
return -1;
}
return ctx_buffer_append(buf, data, len);
}
#endif /* MBEDTLS_TIMING_C */
ret = mbedtls_net_send(ctx, data, len);
if (ret < 0) {
mbedtls_printf("net_send returned -%#04x\n", (unsigned int) -ret);
}
return ret;
}
typedef struct {
mbedtls_net_context *dst;
const char *way;
const char *type;
unsigned len;
unsigned char buf[MAX_MSG_SIZE];
} packet;
/* Print packet. Outgoing packets come with a reason (forward, dupl, etc.) */
static void print_packet(const packet *p, const char *why)
{
#if defined(MBEDTLS_TIMING_C)
if (why == NULL) {
mbedtls_printf(" %05u dispatch %s %s (%u bytes)\n",
elapsed_time(), p->way, p->type, p->len);
} else {
mbedtls_printf(" %05u dispatch %s %s (%u bytes): %s\n",
elapsed_time(), p->way, p->type, p->len, why);
}
#else
if (why == NULL) {
mbedtls_printf(" dispatch %s %s (%u bytes)\n",
p->way, p->type, p->len);
} else {
mbedtls_printf(" dispatch %s %s (%u bytes): %s\n",
p->way, p->type, p->len, why);
}
#endif
fflush(stdout);
}
/*
* In order to test the server's behaviour when receiving a ClientHello after
* the connection is established (this could be a hard reset from the client,
* but the server must not drop the existing connection before establishing
* client reachability, see RFC 6347 Section 4.2.8), we memorize the first
* ClientHello we see (which can't have a cookie), then replay it after the
* first ApplicationData record - then we're done.
*
* This is controlled by the inject_clihlo option.
*
* We want an explicit state and a place to store the packet.
*/
typedef enum {
ICH_INIT, /* haven't seen the first ClientHello yet */
ICH_CACHED, /* cached the initial ClientHello */
ICH_INJECTED, /* ClientHello already injected, done */
} inject_clihlo_state_t;
static inject_clihlo_state_t inject_clihlo_state;
static packet initial_clihlo;
static int send_packet(const packet *p, const char *why)
{
int ret;
mbedtls_net_context *dst = p->dst;
/* save initial ClientHello? */
if (opt.inject_clihlo != 0 &&
inject_clihlo_state == ICH_INIT &&
strcmp(p->type, "ClientHello") == 0) {
memcpy(&initial_clihlo, p, sizeof(packet));
inject_clihlo_state = ICH_CACHED;
}
/* insert corrupted CID record? */
if (opt.bad_cid != 0 &&
strcmp(p->type, "CID") == 0 &&
(rand() % opt.bad_cid) == 0) {
unsigned char buf[MAX_MSG_SIZE];
memcpy(buf, p->buf, p->len);
/* The CID resides at offset 11 in the DTLS record header. */
buf[11] ^= 1;
print_packet(p, "modified CID");
if ((ret = dispatch_data(dst, buf, p->len)) <= 0) {
mbedtls_printf(" ! dispatch returned %d\n", ret);
return ret;
}
}
/* insert corrupted ApplicationData record? */
if (opt.bad_ad &&
strcmp(p->type, "ApplicationData") == 0) {
unsigned char buf[MAX_MSG_SIZE];
memcpy(buf, p->buf, p->len);
if (p->len <= 13) {
mbedtls_printf(" ! can't corrupt empty AD record");
} else {
++buf[13];
print_packet(p, "corrupted");
}
if ((ret = dispatch_data(dst, buf, p->len)) <= 0) {
mbedtls_printf(" ! dispatch returned %d\n", ret);
return ret;
}
}
print_packet(p, why);
if ((ret = dispatch_data(dst, p->buf, p->len)) <= 0) {
mbedtls_printf(" ! dispatch returned %d\n", ret);
return ret;
}
/* Don't duplicate Application Data, only handshake covered */
if (opt.duplicate != 0 &&
strcmp(p->type, "ApplicationData") != 0 &&
rand() % opt.duplicate == 0) {
print_packet(p, "duplicated");
if ((ret = dispatch_data(dst, p->buf, p->len)) <= 0) {
mbedtls_printf(" ! dispatch returned %d\n", ret);
return ret;
}
}
/* Inject ClientHello after first ApplicationData */
if (opt.inject_clihlo != 0 &&
inject_clihlo_state == ICH_CACHED &&
strcmp(p->type, "ApplicationData") == 0) {
print_packet(&initial_clihlo, "injected");
if ((ret = dispatch_data(dst, initial_clihlo.buf,
initial_clihlo.len)) <= 0) {
mbedtls_printf(" ! dispatch returned %d\n", ret);
return ret;
}
inject_clihlo_state = ICH_INJECTED;
}
return 0;
}
#define MAX_DELAYED_MSG 5
static size_t prev_len;
static packet prev[MAX_DELAYED_MSG];
static void clear_pending(void)
{
memset(&prev, 0, sizeof(prev));
prev_len = 0;
}
static void delay_packet(packet *delay)
{
if (prev_len == MAX_DELAYED_MSG) {
return;
}
memcpy(&prev[prev_len++], delay, sizeof(packet));
}
static int send_delayed(void)
{
uint8_t offset;
int ret;
for (offset = 0; offset < prev_len; offset++) {
ret = send_packet(&prev[offset], "delayed");
if (ret != 0) {
return ret;
}
}
clear_pending();
return 0;
}
/*
* Avoid dropping or delaying a packet that was already dropped or delayed
* ("held") twice: this only results in uninteresting timeouts. We can't rely
* on type to identify packets, since during renegotiation they're all
* encrypted. So, rely on size mod 2048 (which is usually just size).
*
* We only hold packets at the level of entire datagrams, not at the level
* of records. In particular, if the peer changes the way it packs multiple
* records into a single datagram, we don't necessarily count the number of
* times a record has been held correctly. However, the only known reason
* why a peer would change datagram packing is disabling the latter on
* retransmission, in which case we'd hold involved records at most
* HOLD_MAX + 1 times.
*/
static unsigned char held[2048] = { 0 };
#define HOLD_MAX 2
static int handle_message(const char *way,
mbedtls_net_context *dst,
mbedtls_net_context *src)
{
int ret;
packet cur;
size_t id;
uint8_t delay_idx;
char **delay_list;
uint8_t delay_list_len;
/* receive packet */
if ((ret = mbedtls_net_recv(src, cur.buf, sizeof(cur.buf))) <= 0) {
mbedtls_printf(" ! mbedtls_net_recv returned %d\n", ret);
return ret;
}
cur.len = ret;
cur.type = msg_type(cur.buf, cur.len);
cur.way = way;
cur.dst = dst;
print_packet(&cur, NULL);
id = cur.len % sizeof(held);
if (strcmp(way, "S <- C") == 0) {
delay_list = opt.delay_cli;
delay_list_len = opt.delay_cli_cnt;
} else {
delay_list = opt.delay_srv;
delay_list_len = opt.delay_srv_cnt;
}
/* Check if message type is in the list of messages
* that should be delayed */
for (delay_idx = 0; delay_idx < delay_list_len; delay_idx++) {
if (delay_list[delay_idx] == NULL) {
continue;
}
if (strcmp(delay_list[delay_idx], cur.type) == 0) {
/* Delay message */
delay_packet(&cur);
/* Remove entry from list */
mbedtls_free(delay_list[delay_idx]);
delay_list[delay_idx] = NULL;
return 0;
}
}
/* do we want to drop, delay, or forward it? */
if ((opt.mtu != 0 &&
cur.len > (unsigned) opt.mtu) ||
(opt.drop != 0 &&
strcmp(cur.type, "CID") != 0 &&
strcmp(cur.type, "ApplicationData") != 0 &&
!(opt.protect_hvr &&
strcmp(cur.type, "HelloVerifyRequest") == 0) &&
cur.len != (size_t) opt.protect_len &&
held[id] < HOLD_MAX &&
rand() % opt.drop == 0)) {
++held[id];
} else if ((opt.delay_ccs == 1 &&
strcmp(cur.type, "ChangeCipherSpec") == 0) ||
(opt.delay != 0 &&
strcmp(cur.type, "CID") != 0 &&
strcmp(cur.type, "ApplicationData") != 0 &&
!(opt.protect_hvr &&
strcmp(cur.type, "HelloVerifyRequest") == 0) &&
cur.len != (size_t) opt.protect_len &&
held[id] < HOLD_MAX &&
rand() % opt.delay == 0)) {
++held[id];
delay_packet(&cur);
} else {
/* forward and possibly duplicate */
if ((ret = send_packet(&cur, "forwarded")) != 0) {
return ret;
}
/* send previously delayed messages if any */
ret = send_delayed();
if (ret != 0) {
return ret;
}
}
return 0;
}
int main(int argc, char *argv[])
{
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
uint8_t delay_idx;
mbedtls_net_context listen_fd, client_fd, server_fd;
#if defined(MBEDTLS_TIMING_C)
struct timeval tm;
#endif
struct timeval *tm_ptr = NULL;
int nb_fds;
fd_set read_fds;
mbedtls_net_init(&listen_fd);
mbedtls_net_init(&client_fd);
mbedtls_net_init(&server_fd);
get_options(argc, argv);
/*
* Decisions to drop/delay/duplicate packets are pseudo-random: dropping
* exactly 1 in N packets would lead to problems when a flight has exactly
* N packets: the same packet would be dropped on every resend.
*
* In order to be able to reproduce problems reliably, the seed may be
* specified explicitly.
*/
if (opt.seed == 0) {
#if defined(MBEDTLS_HAVE_TIME)
opt.seed = (unsigned int) mbedtls_time(NULL);
#else
opt.seed = 1;
#endif /* MBEDTLS_HAVE_TIME */
mbedtls_printf(" . Pseudo-random seed: %u\n", opt.seed);
}
srand(opt.seed);
/*
* 0. "Connect" to the server
*/
mbedtls_printf(" . Connect to server on UDP/%s/%s ...",
opt.server_addr, opt.server_port);
fflush(stdout);
if ((ret = mbedtls_net_connect(&server_fd, opt.server_addr, opt.server_port,
MBEDTLS_NET_PROTO_UDP)) != 0) {
mbedtls_printf(" failed\n ! mbedtls_net_connect returned %d\n\n", ret);
goto exit;
}
mbedtls_printf(" ok\n");
/*
* 1. Setup the "listening" UDP socket
*/
mbedtls_printf(" . Bind on UDP/%s/%s ...",
opt.listen_addr, opt.listen_port);
fflush(stdout);
if ((ret = mbedtls_net_bind(&listen_fd, opt.listen_addr, opt.listen_port,
MBEDTLS_NET_PROTO_UDP)) != 0) {
mbedtls_printf(" failed\n ! mbedtls_net_bind returned %d\n\n", ret);
goto exit;
}
mbedtls_printf(" ok\n");
/*
* 2. Wait until a client connects
*/
accept:
mbedtls_net_free(&client_fd);
mbedtls_printf(" . Waiting for a remote connection ...");
fflush(stdout);
if ((ret = mbedtls_net_accept(&listen_fd, &client_fd,
NULL, 0, NULL)) != 0) {
mbedtls_printf(" failed\n ! mbedtls_net_accept returned %d\n\n", ret);
goto exit;
}
mbedtls_printf(" ok\n");
/*
* 3. Forward packets forever (kill the process to terminate it)
*/
clear_pending();
memset(held, 0, sizeof(held));
nb_fds = client_fd.fd;
if (nb_fds < server_fd.fd) {
nb_fds = server_fd.fd;
}
if (nb_fds < listen_fd.fd) {
nb_fds = listen_fd.fd;
}
++nb_fds;
#if defined(MBEDTLS_TIMING_C)
if (opt.pack > 0) {
outbuf[0].ctx = &server_fd;
outbuf[0].description = "S <- C";
outbuf[0].num_datagrams = 0;
outbuf[0].len = 0;
outbuf[1].ctx = &client_fd;
outbuf[1].description = "S -> C";
outbuf[1].num_datagrams = 0;
outbuf[1].len = 0;
}
#endif /* MBEDTLS_TIMING_C */
while (1) {
#if defined(MBEDTLS_TIMING_C)
if (opt.pack > 0) {
unsigned max_wait_server, max_wait_client, max_wait;
max_wait_server = ctx_buffer_time_remaining(&outbuf[0]);
max_wait_client = ctx_buffer_time_remaining(&outbuf[1]);
max_wait = (unsigned) -1;
if (max_wait_server == 0) {
ctx_buffer_flush(&outbuf[0]);
} else {
max_wait = max_wait_server;
}
if (max_wait_client == 0) {
ctx_buffer_flush(&outbuf[1]);
} else {
if (max_wait_client < max_wait) {
max_wait = max_wait_client;
}
}
if (max_wait != (unsigned) -1) {
tm.tv_sec = max_wait / 1000;
tm.tv_usec = (max_wait % 1000) * 1000;
tm_ptr = &tm;
} else {
tm_ptr = NULL;
}
}
#endif /* MBEDTLS_TIMING_C */
FD_ZERO(&read_fds);
FD_SET(server_fd.fd, &read_fds);
FD_SET(client_fd.fd, &read_fds);
FD_SET(listen_fd.fd, &read_fds);
if ((ret = select(nb_fds, &read_fds, NULL, NULL, tm_ptr)) < 0) {
perror("select");
goto exit;
}
if (FD_ISSET(listen_fd.fd, &read_fds)) {
goto accept;
}
if (FD_ISSET(client_fd.fd, &read_fds)) {
if ((ret = handle_message("S <- C",
&server_fd, &client_fd)) != 0) {
goto accept;
}
}
if (FD_ISSET(server_fd.fd, &read_fds)) {
if ((ret = handle_message("S -> C",
&client_fd, &server_fd)) != 0) {
goto accept;
}
}
}
exit:
#ifdef MBEDTLS_ERROR_C
if (exit_code != MBEDTLS_EXIT_SUCCESS) {
char error_buf[100];
mbedtls_strerror(ret, error_buf, 100);
mbedtls_printf("Last error was: -0x%04X - %s\n\n", (unsigned int) -ret, error_buf);
fflush(stdout);
}
#endif
for (delay_idx = 0; delay_idx < MAX_DELAYED_HS; delay_idx++) {
mbedtls_free(opt.delay_cli[delay_idx]);
mbedtls_free(opt.delay_srv[delay_idx]);
}
mbedtls_net_free(&client_fd);
mbedtls_net_free(&server_fd);
mbedtls_net_free(&listen_fd);
mbedtls_exit(exit_code);
}
#endif /* MBEDTLS_NET_C */
|