2 * UDP proxy: emulate an unreliable UDP connexion for DTLS testing
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
19 * This file is part of mbed TLS (https://tls.mbed.org)
23 * Warning: this is an internal utility program we use for tests.
24 * It does break some abstractions from the NET layer, and is thus NOT an
25 * example of good general usage.
28 #if !defined(MBEDTLS_CONFIG_FILE)
29 #include "mbedtls/config.h"
31 #include MBEDTLS_CONFIG_FILE
34 #if defined(MBEDTLS_PLATFORM_C)
35 #include "mbedtls/platform.h"
40 #define mbedtls_time time
41 #define mbedtls_time_t time_t
42 #define mbedtls_printf printf
43 #define mbedtls_calloc calloc
44 #define mbedtls_free free
45 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
46 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
47 #endif /* MBEDTLS_PLATFORM_C */
49 #if !defined(MBEDTLS_NET_C)
52 mbedtls_printf( "MBEDTLS_NET_C not defined.\n" );
57 #include "mbedtls/net_sockets.h"
58 #include "mbedtls/error.h"
59 #include "mbedtls/ssl.h"
60 #include "mbedtls/timing.h"
65 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
70 #if defined(_WIN32_WCE)
71 #pragma comment( lib, "ws2.lib" )
73 #pragma comment( lib, "ws2_32.lib" )
76 #else /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
78 #include <sys/types.h>
80 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
82 #define MAX_MSG_SIZE 16384 + 2048 /* max record/datagram size */
84 #define DFL_SERVER_ADDR "localhost"
85 #define DFL_SERVER_PORT "4433"
86 #define DFL_LISTEN_ADDR "localhost"
87 #define DFL_LISTEN_PORT "5556"
90 #if defined(MBEDTLS_TIMING_C)
92 " pack=%%d default: 0 (don't pack)\n" \
93 " options: t > 0 (pack for t milliseconds)\n"
99 "\n usage: udp_proxy param=<>...\n" \
100 "\n acceptable parameters:\n" \
101 " server_addr=%%s default: localhost\n" \
102 " server_port=%%d default: 4433\n" \
103 " listen_addr=%%s default: localhost\n" \
104 " listen_port=%%d default: 4433\n" \
106 " duplicate=%%d default: 0 (no duplication)\n" \
107 " duplicate about 1:N packets randomly\n" \
108 " delay=%%d default: 0 (no delayed packets)\n" \
109 " delay about 1:N packets randomly\n" \
110 " delay_ccs=0/1 default: 0 (don't delay ChangeCipherSpec)\n" \
111 " delay_cli=%%s Handshake message from client that should be\n"\
112 " delayed. Possible values are 'ClientHello',\n" \
113 " 'Certificate', 'CertificateVerify', and\n" \
114 " 'ClientKeyExchange'.\n" \
115 " May be used multiple times, even for the same\n"\
116 " message, in which case the respective message\n"\
117 " gets delayed multiple times.\n" \
118 " delay_srv=%%s Handshake message from server that should be\n"\
119 " delayed. Possible values are 'HelloRequest',\n"\
120 " 'ServerHello', 'ServerHelloDone', 'Certificate'\n"\
121 " 'ServerKeyExchange', 'NewSessionTicket',\n"\
122 " 'HelloVerifyRequest' and ''CertificateRequest'.\n"\
123 " May be used multiple times, even for the same\n"\
124 " message, in which case the respective message\n"\
125 " gets delayed multiple times.\n" \
126 " drop=%%d default: 0 (no dropped packets)\n" \
127 " drop about 1:N packets randomly\n" \
128 " mtu=%%d default: 0 (unlimited)\n" \
129 " drop packets larger than N bytes\n" \
130 " bad_ad=0/1 default: 0 (don't add bad ApplicationData)\n" \
131 " protect_hvr=0/1 default: 0 (don't protect HelloVerifyRequest)\n" \
132 " protect_len=%%d default: (don't protect packets of this size)\n" \
134 " seed=%%d default: (use current time)\n" \
142 #define MAX_DELAYED_HS 10
144 static struct options
146 const char *server_addr; /* address to forward packets to */
147 const char *server_port; /* port to forward packets to */
148 const char *listen_addr; /* address for accepting client connections */
149 const char *listen_port; /* port for accepting client connections */
151 int duplicate; /* duplicate 1 in N packets (none if 0) */
152 int delay; /* delay 1 packet in N (none if 0) */
153 int delay_ccs; /* delay ChangeCipherSpec */
154 char* delay_cli[MAX_DELAYED_HS]; /* handshake types of messages from
155 * client that should be delayed. */
156 uint8_t delay_cli_cnt; /* Number of entries in delay_cli. */
157 char* delay_srv[MAX_DELAYED_HS]; /* handshake types of messages from
158 * server that should be delayed. */
159 uint8_t delay_srv_cnt; /* Number of entries in delay_srv. */
160 int drop; /* drop 1 packet in N (none if 0) */
161 int mtu; /* drop packets larger than this */
162 int bad_ad; /* inject corrupted ApplicationData record */
163 int protect_hvr; /* never drop or delay HelloVerifyRequest */
164 int protect_len; /* never drop/delay packet of the given size*/
165 unsigned pack; /* merge packets into single datagram for
166 * at most \c merge milliseconds if > 0 */
167 unsigned int seed; /* seed for "random" events */
170 static void exit_usage( const char *name, const char *value )
173 mbedtls_printf( " unknown option or missing value: %s\n", name );
175 mbedtls_printf( " option %s: illegal value: %s\n", name, value );
177 mbedtls_printf( USAGE );
181 static void get_options( int argc, char *argv[] )
186 opt.server_addr = DFL_SERVER_ADDR;
187 opt.server_port = DFL_SERVER_PORT;
188 opt.listen_addr = DFL_LISTEN_ADDR;
189 opt.listen_port = DFL_LISTEN_PORT;
191 /* Other members default to 0 */
193 opt.delay_cli_cnt = 0;
194 opt.delay_srv_cnt = 0;
195 memset( opt.delay_cli, 0, sizeof( opt.delay_cli ) );
196 memset( opt.delay_srv, 0, sizeof( opt.delay_srv ) );
198 for( i = 1; i < argc; i++ )
201 if( ( q = strchr( p, '=' ) ) == NULL )
202 exit_usage( p, NULL );
205 if( strcmp( p, "server_addr" ) == 0 )
207 else if( strcmp( p, "server_port" ) == 0 )
209 else if( strcmp( p, "listen_addr" ) == 0 )
211 else if( strcmp( p, "listen_port" ) == 0 )
213 else if( strcmp( p, "duplicate" ) == 0 )
215 opt.duplicate = atoi( q );
216 if( opt.duplicate < 0 || opt.duplicate > 20 )
219 else if( strcmp( p, "delay" ) == 0 )
221 opt.delay = atoi( q );
222 if( opt.delay < 0 || opt.delay > 20 || opt.delay == 1 )
225 else if( strcmp( p, "delay_ccs" ) == 0 )
227 opt.delay_ccs = atoi( q );
228 if( opt.delay_ccs < 0 || opt.delay_ccs > 1 )
231 else if( strcmp( p, "delay_cli" ) == 0 ||
232 strcmp( p, "delay_srv" ) == 0 )
239 if( strcmp( p, "delay_cli" ) == 0 )
241 delay_cnt = &opt.delay_cli_cnt;
242 delay_list = opt.delay_cli;
246 delay_cnt = &opt.delay_srv_cnt;
247 delay_list = opt.delay_srv;
250 if( *delay_cnt == MAX_DELAYED_HS )
252 mbedtls_printf( " too many uses of %s: only %d allowed\n",
254 exit_usage( p, NULL );
258 buf = mbedtls_calloc( 1, len + 1 );
261 mbedtls_printf( " Allocation failure\n" );
264 memcpy( buf, q, len + 1 );
266 delay_list[ (*delay_cnt)++ ] = buf;
268 else if( strcmp( p, "drop" ) == 0 )
270 opt.drop = atoi( q );
271 if( opt.drop < 0 || opt.drop > 20 || opt.drop == 1 )
274 else if( strcmp( p, "pack" ) == 0 )
276 #if defined(MBEDTLS_TIMING_C)
277 opt.pack = (unsigned) atoi( q );
279 mbedtls_printf( " option pack only defined if MBEDTLS_TIMING_C is enabled\n" );
283 else if( strcmp( p, "mtu" ) == 0 )
286 if( opt.mtu < 0 || opt.mtu > MAX_MSG_SIZE )
289 else if( strcmp( p, "bad_ad" ) == 0 )
291 opt.bad_ad = atoi( q );
292 if( opt.bad_ad < 0 || opt.bad_ad > 1 )
295 else if( strcmp( p, "protect_hvr" ) == 0 )
297 opt.protect_hvr = atoi( q );
298 if( opt.protect_hvr < 0 || opt.protect_hvr > 1 )
301 else if( strcmp( p, "protect_len" ) == 0 )
303 opt.protect_len = atoi( q );
304 if( opt.protect_len < 0 )
307 else if( strcmp( p, "seed" ) == 0 )
309 opt.seed = atoi( q );
314 exit_usage( p, NULL );
318 static const char *msg_type( unsigned char *msg, size_t len )
320 if( len < 1 ) return( "Invalid" );
323 case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC: return( "ChangeCipherSpec" );
324 case MBEDTLS_SSL_MSG_ALERT: return( "Alert" );
325 case MBEDTLS_SSL_MSG_APPLICATION_DATA: return( "ApplicationData" );
326 case MBEDTLS_SSL_MSG_HANDSHAKE: break; /* See below */
327 default: return( "Unknown" );
330 if( len < 13 + 12 ) return( "Invalid handshake" );
333 * Our handshake message are less than 2^16 bytes long, so they should
334 * have 0 as the first byte of length, frag_offset and frag_length.
335 * Otherwise, assume they are encrypted.
337 if( msg[14] || msg[19] || msg[22] ) return( "Encrypted handshake" );
341 case MBEDTLS_SSL_HS_HELLO_REQUEST: return( "HelloRequest" );
342 case MBEDTLS_SSL_HS_CLIENT_HELLO: return( "ClientHello" );
343 case MBEDTLS_SSL_HS_SERVER_HELLO: return( "ServerHello" );
344 case MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST: return( "HelloVerifyRequest" );
345 case MBEDTLS_SSL_HS_NEW_SESSION_TICKET: return( "NewSessionTicket" );
346 case MBEDTLS_SSL_HS_CERTIFICATE: return( "Certificate" );
347 case MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE: return( "ServerKeyExchange" );
348 case MBEDTLS_SSL_HS_CERTIFICATE_REQUEST: return( "CertificateRequest" );
349 case MBEDTLS_SSL_HS_SERVER_HELLO_DONE: return( "ServerHelloDone" );
350 case MBEDTLS_SSL_HS_CERTIFICATE_VERIFY: return( "CertificateVerify" );
351 case MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE: return( "ClientKeyExchange" );
352 case MBEDTLS_SSL_HS_FINISHED: return( "Finished" );
353 default: return( "Unknown handshake" );
357 #if defined(MBEDTLS_TIMING_C)
358 /* Return elapsed time in milliseconds since the first call */
359 static unsigned ellapsed_time( void )
361 static int initialized = 0;
362 static struct mbedtls_timing_hr_time hires;
364 if( initialized == 0 )
366 (void) mbedtls_timing_get_timer( &hires, 1 );
371 return( mbedtls_timing_get_timer( &hires, 0 ) );
376 mbedtls_net_context *ctx;
378 const char *description;
380 unsigned packet_lifetime;
381 unsigned num_datagrams;
383 unsigned char data[MAX_MSG_SIZE];
388 static ctx_buffer outbuf[2];
390 static int ctx_buffer_flush( ctx_buffer *buf )
394 mbedtls_printf( " %05u flush %s: %u bytes, %u datagrams, last %u ms\n",
395 ellapsed_time(), buf->description,
396 (unsigned) buf->len, buf->num_datagrams,
397 ellapsed_time() - buf->packet_lifetime );
399 ret = mbedtls_net_send( buf->ctx, buf->data, buf->len );
402 buf->num_datagrams = 0;
407 static unsigned ctx_buffer_time_remaining( ctx_buffer *buf )
409 unsigned const cur_time = ellapsed_time();
411 if( buf->num_datagrams == 0 )
412 return( (unsigned) -1 );
414 if( cur_time - buf->packet_lifetime >= opt.pack )
417 return( opt.pack - ( cur_time - buf->packet_lifetime ) );
420 static int ctx_buffer_append( ctx_buffer *buf,
421 const unsigned char * data,
426 if( len > (size_t) INT_MAX )
429 if( len > sizeof( buf->data ) )
431 mbedtls_printf( " ! buffer size %u too large (max %u)\n",
432 (unsigned) len, (unsigned) sizeof( buf->data ) );
436 if( sizeof( buf->data ) - buf->len < len )
438 if( ( ret = ctx_buffer_flush( buf ) ) <= 0 )
442 memcpy( buf->data + buf->len, data, len );
445 if( ++buf->num_datagrams == 1 )
446 buf->packet_lifetime = ellapsed_time();
450 #endif /* MBEDTLS_TIMING_C */
452 static int dispatch_data( mbedtls_net_context *ctx,
453 const unsigned char * data,
456 #if defined(MBEDTLS_TIMING_C)
457 ctx_buffer *buf = NULL;
460 if( outbuf[0].ctx == ctx )
462 else if( outbuf[1].ctx == ctx )
468 return( ctx_buffer_append( buf, data, len ) );
470 #endif /* MBEDTLS_TIMING_C */
472 return( mbedtls_net_send( ctx, data, len ) );
477 mbedtls_net_context *dst;
481 unsigned char buf[MAX_MSG_SIZE];
484 /* Print packet. Outgoing packets come with a reason (forward, dupl, etc.) */
485 void print_packet( const packet *p, const char *why )
487 #if defined(MBEDTLS_TIMING_C)
489 mbedtls_printf( " %05u dispatch %s %s (%u bytes)\n",
490 ellapsed_time(), p->way, p->type, p->len );
492 mbedtls_printf( " %05u dispatch %s %s (%u bytes): %s\n",
493 ellapsed_time(), p->way, p->type, p->len, why );
496 mbedtls_printf( " dispatch %s %s (%u bytes)\n",
497 p->way, p->type, p->len );
499 mbedtls_printf( " dispatch %s %s (%u bytes): %s\n",
500 p->way, p->type, p->len, why );
506 int send_packet( const packet *p, const char *why )
509 mbedtls_net_context *dst = p->dst;
511 /* insert corrupted ApplicationData record? */
513 strcmp( p->type, "ApplicationData" ) == 0 )
515 unsigned char buf[MAX_MSG_SIZE];
516 memcpy( buf, p->buf, p->len );
520 mbedtls_printf( " ! can't corrupt empty AD record" );
525 print_packet( p, "corrupted" );
528 if( ( ret = dispatch_data( dst, buf, p->len ) ) <= 0 )
530 mbedtls_printf( " ! dispatch returned %d\n", ret );
535 print_packet( p, why );
536 if( ( ret = dispatch_data( dst, p->buf, p->len ) ) <= 0 )
538 mbedtls_printf( " ! dispatch returned %d\n", ret );
542 /* Don't duplicate Application Data, only handshake covered */
543 if( opt.duplicate != 0 &&
544 strcmp( p->type, "ApplicationData" ) != 0 &&
545 rand() % opt.duplicate == 0 )
547 print_packet( p, "duplicated" );
549 if( ( ret = dispatch_data( dst, p->buf, p->len ) ) <= 0 )
551 mbedtls_printf( " ! dispatch returned %d\n", ret );
559 #define MAX_DELAYED_MSG 5
560 static size_t prev_len;
561 static packet prev[MAX_DELAYED_MSG];
563 void clear_pending( void )
565 memset( &prev, 0, sizeof( prev ) );
569 void delay_packet( packet *delay )
571 if( prev_len == MAX_DELAYED_MSG )
574 memcpy( &prev[prev_len++], delay, sizeof( packet ) );
581 for( offset = 0; offset < prev_len; offset++ )
583 ret = send_packet( &prev[offset], "delayed" );
593 * Avoid dropping or delaying a packet that was already dropped twice: this
594 * only results in uninteresting timeouts. We can't rely on type to identify
595 * packets, since during renegotiation they're all encrypted. So, rely on
596 * size mod 2048 (which is usually just size).
598 static unsigned char dropped[2048] = { 0 };
601 /* We only drop packets at the level of entire datagrams, not at the level
602 * of records. In particular, if the peer changes the way it packs multiple
603 * records into a single datagram, we don't necessarily count the number of
604 * times a record has been dropped correctly. However, the only known reason
605 * why a peer would change datagram packing is disabling the latter on
606 * retransmission, in which case we'd drop involved records at most
607 * DROP_MAX + 1 times. */
608 void update_dropped( const packet *p )
610 size_t id = p->len % sizeof( dropped );
614 int handle_message( const char *way,
615 mbedtls_net_context *dst,
616 mbedtls_net_context *src )
624 uint8_t delay_list_len;
627 if( ( ret = mbedtls_net_recv( src, cur.buf, sizeof( cur.buf ) ) ) <= 0 )
629 mbedtls_printf( " ! mbedtls_net_recv returned %d\n", ret );
634 cur.type = msg_type( cur.buf, cur.len );
637 print_packet( &cur, NULL );
639 id = cur.len % sizeof( dropped );
641 if( strcmp( way, "S <- C" ) == 0 )
643 delay_list = opt.delay_cli;
644 delay_list_len = opt.delay_cli_cnt;
648 delay_list = opt.delay_srv;
649 delay_list_len = opt.delay_srv_cnt;
652 /* Check if message type is in the list of messages
653 * that should be delayed */
654 for( delay_idx = 0; delay_idx < delay_list_len; delay_idx++ )
656 if( delay_list[ delay_idx ] == NULL )
659 if( strcmp( delay_list[ delay_idx ], cur.type ) == 0 )
662 delay_packet( &cur );
664 /* Remove entry from list */
665 mbedtls_free( delay_list[delay_idx] );
666 delay_list[delay_idx] = NULL;
672 /* do we want to drop, delay, or forward it? */
673 if( ( opt.mtu != 0 &&
674 cur.len > (unsigned) opt.mtu ) ||
676 strcmp( cur.type, "ApplicationData" ) != 0 &&
677 ! ( opt.protect_hvr &&
678 strcmp( cur.type, "HelloVerifyRequest" ) == 0 ) &&
679 cur.len != (size_t) opt.protect_len &&
680 dropped[id] < DROP_MAX &&
681 rand() % opt.drop == 0 ) )
683 update_dropped( &cur );
685 else if( ( opt.delay_ccs == 1 &&
686 strcmp( cur.type, "ChangeCipherSpec" ) == 0 ) ||
688 strcmp( cur.type, "ApplicationData" ) != 0 &&
689 ! ( opt.protect_hvr &&
690 strcmp( cur.type, "HelloVerifyRequest" ) == 0 ) &&
691 cur.len != (size_t) opt.protect_len &&
692 dropped[id] < DROP_MAX &&
693 rand() % opt.delay == 0 ) )
695 delay_packet( &cur );
699 /* forward and possibly duplicate */
700 if( ( ret = send_packet( &cur, "forwarded" ) ) != 0 )
703 /* send previously delayed messages if any */
704 ret = send_delayed();
712 int main( int argc, char *argv[] )
715 int exit_code = MBEDTLS_EXIT_FAILURE;
718 mbedtls_net_context listen_fd, client_fd, server_fd;
720 #if defined( MBEDTLS_TIMING_C )
724 struct timeval *tm_ptr = NULL;
729 mbedtls_net_init( &listen_fd );
730 mbedtls_net_init( &client_fd );
731 mbedtls_net_init( &server_fd );
733 get_options( argc, argv );
736 * Decisions to drop/delay/duplicate packets are pseudo-random: dropping
737 * exactly 1 in N packets would lead to problems when a flight has exactly
738 * N packets: the same packet would be dropped on every resend.
740 * In order to be able to reproduce problems reliably, the seed may be
741 * specified explicitly.
745 opt.seed = (unsigned int) time( NULL );
746 mbedtls_printf( " . Pseudo-random seed: %u\n", opt.seed );
752 * 0. "Connect" to the server
754 mbedtls_printf( " . Connect to server on UDP/%s/%s ...",
755 opt.server_addr, opt.server_port );
758 if( ( ret = mbedtls_net_connect( &server_fd, opt.server_addr, opt.server_port,
759 MBEDTLS_NET_PROTO_UDP ) ) != 0 )
761 mbedtls_printf( " failed\n ! mbedtls_net_connect returned %d\n\n", ret );
765 mbedtls_printf( " ok\n" );
768 * 1. Setup the "listening" UDP socket
770 mbedtls_printf( " . Bind on UDP/%s/%s ...",
771 opt.listen_addr, opt.listen_port );
774 if( ( ret = mbedtls_net_bind( &listen_fd, opt.listen_addr, opt.listen_port,
775 MBEDTLS_NET_PROTO_UDP ) ) != 0 )
777 mbedtls_printf( " failed\n ! mbedtls_net_bind returned %d\n\n", ret );
781 mbedtls_printf( " ok\n" );
784 * 2. Wait until a client connects
787 mbedtls_net_free( &client_fd );
789 mbedtls_printf( " . Waiting for a remote connection ..." );
792 if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
793 NULL, 0, NULL ) ) != 0 )
795 mbedtls_printf( " failed\n ! mbedtls_net_accept returned %d\n\n", ret );
799 mbedtls_printf( " ok\n" );
802 * 3. Forward packets forever (kill the process to terminate it)
805 memset( dropped, 0, sizeof( dropped ) );
807 nb_fds = client_fd.fd;
808 if( nb_fds < server_fd.fd )
809 nb_fds = server_fd.fd;
810 if( nb_fds < listen_fd.fd )
811 nb_fds = listen_fd.fd;
814 #if defined(MBEDTLS_TIMING_C)
817 outbuf[0].ctx = &server_fd;
818 outbuf[0].description = "S <- C";
819 outbuf[0].num_datagrams = 0;
822 outbuf[1].ctx = &client_fd;
823 outbuf[1].description = "S -> C";
824 outbuf[1].num_datagrams = 0;
827 #endif /* MBEDTLS_TIMING_C */
831 #if defined(MBEDTLS_TIMING_C)
834 unsigned max_wait_server, max_wait_client, max_wait;
835 max_wait_server = ctx_buffer_time_remaining( &outbuf[0] );
836 max_wait_client = ctx_buffer_time_remaining( &outbuf[1] );
838 max_wait = (unsigned) -1;
840 if( max_wait_server == 0 )
841 ctx_buffer_flush( &outbuf[0] );
843 max_wait = max_wait_server;
845 if( max_wait_client == 0 )
846 ctx_buffer_flush( &outbuf[1] );
849 if( max_wait_client < max_wait )
850 max_wait = max_wait_client;
853 if( max_wait != (unsigned) -1 )
855 tm.tv_sec = max_wait / 1000;
856 tm.tv_usec = ( max_wait % 1000 ) * 1000;
865 #endif /* MBEDTLS_TIMING_C */
867 FD_ZERO( &read_fds );
868 FD_SET( server_fd.fd, &read_fds );
869 FD_SET( client_fd.fd, &read_fds );
870 FD_SET( listen_fd.fd, &read_fds );
872 if( ( ret = select( nb_fds, &read_fds, NULL, NULL, tm_ptr ) ) < 0 )
878 if( FD_ISSET( listen_fd.fd, &read_fds ) )
881 if( FD_ISSET( client_fd.fd, &read_fds ) )
883 if( ( ret = handle_message( "S <- C",
884 &server_fd, &client_fd ) ) != 0 )
888 if( FD_ISSET( server_fd.fd, &read_fds ) )
890 if( ( ret = handle_message( "S -> C",
891 &client_fd, &server_fd ) ) != 0 )
897 exit_code = MBEDTLS_EXIT_SUCCESS;
901 #ifdef MBEDTLS_ERROR_C
902 if( exit_code != MBEDTLS_EXIT_SUCCESS )
905 mbedtls_strerror( ret, error_buf, 100 );
906 mbedtls_printf( "Last error was: -0x%04X - %s\n\n", - ret, error_buf );
911 for( delay_idx = 0; delay_idx < MAX_DELAYED_HS; delay_idx++ )
913 mbedtls_free( opt.delay_cli + delay_idx );
914 mbedtls_free( opt.delay_srv + delay_idx );
917 mbedtls_net_free( &client_fd );
918 mbedtls_net_free( &server_fd );
919 mbedtls_net_free( &listen_fd );
922 mbedtls_printf( " Press Enter to exit this program.\n" );
923 fflush( stdout ); getchar();
929 #endif /* MBEDTLS_NET_C */