tests/mini-loss.c

   1 /*
   2  * Copyright (C) 2012 Free Software Foundation, Inc.
   3  *
   4  * Author: Nikos Mavrogiannopoulos
   5  *
   6  * This file is part of GnuTLS.
   7  *
   8  * GnuTLS is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * GnuTLS is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with GnuTLS; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #if defined(_WIN32)
  31
  32 int main()
  33 {
  34   exit(77);
  35 }
  36
  37 #else
  38
  39 #include <string.h>
  40 #include <sys/types.h>
  41 #include <netinet/in.h>
  42 #include <sys/socket.h>
  43 #include <sys/wait.h>
  44 #include <arpa/inet.h>
  45 #include <unistd.h>
  46 #include <gnutls/gnutls.h>
  47 #include <gnutls/dtls.h>
  48
  49 #include "utils.h"
  50
  51 /* This program simulates packet loss in DTLS datagrams using
  52  * the blocking functions. Idea taken from test app of
  53  * Sean Buckheister.
  54  */
  55
  56 static void print_type(const unsigned char* buf, int size)
  57 {
  58   if (buf[0] == 22 && size >= 13) {
  59     if (buf[13] == 1)
  60       fprintf(stderr, "Client Hello\n");
  61     else if (buf[13] == 2)
  62       fprintf(stderr, "Server Hello\n");
  63     else if (buf[13] == 12)
  64       fprintf(stderr, "Server Key exchange\n");
  65     else if (buf[13] == 14)
  66       fprintf(stderr, "Server Hello Done\n");
  67     else if (buf[13] == 11)
  68       fprintf(stderr, "Certificate\n");
  69     else if (buf[13] == 16)
  70       fprintf(stderr, "Client Key Exchange\n");
  71     else if (buf[4] == 1)
  72       fprintf(stderr, "Finished\n");
  73     else if (buf[13] == 11)
  74       fprintf(stderr, "Server Hello Done\n");
  75     else
  76       fprintf(stderr, "Unknown handshake\n");
  77   } else if (buf[0] == 20) {
  78     fprintf(stderr, "Change Cipher Spec\n");
  79   } else
  80     fprintf(stderr, "Unknown\n");
  81 }
  82
  83 static void
  84 server_log_func (int level, const char *str)
  85 {
  86   fprintf (stderr, "server|<%d>| %s", level, str);
  87 }
  88
  89 static void
  90 client_log_func (int level, const char *str)
  91 {
  92   fprintf (stderr, "client|<%d>| %s", level, str);
  93 }
  94
  95 /* A very basic TLS client, with anonymous authentication.
  96  */
  97
  98 #define MAX_BUF 1024
  99 #define MSG "Hello TLS"
 100
 101 static int counter;
 102 static int packet_to_lose;
 103 gnutls_session_t session;
 104
 105 static ssize_t
 106 push (gnutls_transport_ptr_t tr, const void *data, size_t len)
 107 {
 108 int fd = (long int)tr;
 109
 110   counter++;
 111
 112   if (packet_to_lose != -1 && packet_to_lose == counter) {
 113     if (debug)
 114       {
 115         fprintf(stderr, "Discarding packet %d: ", counter);
 116         print_type(data, len);
 117       }
 118     return len;
 119   }
 120   return send(fd, data, len, 0);
 121 }
 122
 123 static void
 124 client (int fd, int packet)
 125 {
 126   int ret, ii;
 127   char buffer[MAX_BUF + 1];
 128   gnutls_anon_client_credentials_t anoncred;
 129   /* Need to enable anonymous KX specifically. */
 130
 131   gnutls_global_init ();
 132
 133   if (debug)
 134     {
 135       gnutls_global_set_log_function (client_log_func);
 136       gnutls_global_set_log_level (4711);
 137     }
 138
 139   gnutls_anon_allocate_client_credentials (&anoncred);
 140
 141   /* Initialize TLS session
 142    */
 143   gnutls_init (&session, GNUTLS_CLIENT|GNUTLS_DATAGRAM);
 144   gnutls_dtls_set_mtu( session, 1500);
 145
 146   /* Use default priorities */
 147   gnutls_priority_set_direct (session, "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-ECDH:+CURVE-ALL", NULL);
 148
 149   /* put the anonymous credentials to the current session
 150    */
 151   gnutls_credentials_set (session, GNUTLS_CRD_ANON, anoncred);
 152
 153   counter = 0;
 154   packet_to_lose = packet;
 155
 156   gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) fd);
 157   gnutls_transport_set_push_function (session, push);
 158
 159   /* Perform the TLS handshake
 160    */
 161   do
 162     {
 163       ret = gnutls_handshake (session);
 164     }
 165   while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
 166
 167   if (ret < 0)
 168     {
 169       fail ("client: Handshake failed\n");
 170       gnutls_perror (ret);
 171       exit(1);
 172     }
 173   else
 174     {
 175       if (debug)
 176         success ("client: Handshake was completed\n");
 177     }
 178
 179   if (debug)
 180     success ("client: TLS version is: %s\n",
 181              gnutls_protocol_get_name (gnutls_protocol_get_version
 182                                        (session)));
 183
 184   do {
 185     ret = gnutls_record_send (session, MSG, strlen (MSG));
 186   } while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
 187
 188   do {
 189     ret = gnutls_record_recv (session, buffer, MAX_BUF);
 190   } while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
 191
 192   if (ret == 0)
 193     {
 194       if (debug)
 195         success ("client: Peer has closed the TLS connection\n");
 196       goto end;
 197     }
 198   else if (ret < 0)
 199     {
 200       fail ("client: Error: %s\n", gnutls_strerror (ret));
 201       exit(1);
 202     }
 203
 204   if (debug)
 205     {
 206       printf ("- Received %d bytes: ", ret);
 207       for (ii = 0; ii < ret; ii++)
 208         {
 209           fputc (buffer[ii], stdout);
 210         }
 211       fputs ("\n", stdout);
 212     }
 213
 214   gnutls_bye (session, GNUTLS_SHUT_RDWR);
 215
 216 end:
 217
 218   close (fd);
 219
 220   gnutls_deinit (session);
 221
 222   gnutls_anon_free_client_credentials (anoncred);
 223
 224   gnutls_global_deinit ();
 225 }
 226
 227
 228 /* These are global */
 229 gnutls_anon_server_credentials_t anoncred;
 230 pid_t child;
 231
 232 static gnutls_session_t
 233 initialize_tls_session (void)
 234 {
 235   gnutls_session_t session;
 236
 237   gnutls_init (&session, GNUTLS_SERVER|GNUTLS_DATAGRAM);
 238   gnutls_dtls_set_mtu( session, 1500);
 239
 240   /* avoid calling all the priority functions, since the defaults
 241    * are adequate.
 242    */
 243   gnutls_priority_set_direct (session, "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-ECDH:+CURVE-ALL", NULL);
 244
 245   gnutls_credentials_set (session, GNUTLS_CRD_ANON, anoncred);
 246
 247   return session;
 248 }
 249
 250 static void terminate(void)
 251 {
 252 int status;
 253
 254   kill(child, SIGTERM);
 255   wait(&status);
 256   exit(1);
 257 }
 258
 259 static void
 260 server (int fd, int packet)
 261 {
 262 int ret;
 263 char buffer[MAX_BUF + 1];
 264   /* this must be called once in the program
 265    */
 266   gnutls_global_init ();
 267
 268   if (debug)
 269     {
 270       gnutls_global_set_log_function (server_log_func);
 271       gnutls_global_set_log_level (4711);
 272     }
 273
 274   gnutls_anon_allocate_server_credentials (&anoncred);
 275
 276   session = initialize_tls_session ();
 277
 278   counter = 0;
 279   packet_to_lose = packet;
 280
 281   gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) fd);
 282   gnutls_transport_set_push_function (session, push);
 283
 284   do
 285     {
 286       ret = gnutls_handshake (session);
 287     }
 288   while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
 289   if (ret < 0)
 290     {
 291       close (fd);
 292       gnutls_deinit (session);
 293       fail ("server: Handshake has failed (%s)\n\n", gnutls_strerror (ret));
 294       terminate();
 295     }
 296   if (debug)
 297     success ("server: Handshake was completed\n");
 298
 299   if (debug)
 300     success ("server: TLS version is: %s\n",
 301              gnutls_protocol_get_name (gnutls_protocol_get_version
 302                                        (session)));
 303
 304   /* see the Getting peer's information example */
 305   /* print_info(session); */
 306
 307   for (;;)
 308     {
 309       memset (buffer, 0, MAX_BUF + 1);
 310
 311       do {
 312         ret = gnutls_record_recv (session, buffer, MAX_BUF);
 313       } while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
 314
 315       if (ret == 0)
 316         {
 317           if (debug)
 318             success ("server: Peer has closed the GnuTLS connection\n");
 319           break;
 320         }
 321       else if (ret < 0)
 322         {
 323           fail ("server: Received corrupted data(%d). Closing...\n", ret);
 324           terminate();
 325         }
 326       else if (ret > 0)
 327         {
 328           /* echo data back to the client
 329            */
 330           do {
 331             ret = gnutls_record_send (session, buffer, strlen (buffer));
 332           } while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
 333         }
 334     }
 335   /* do not wait for the peer to close the connection.
 336    */
 337   gnutls_bye (session, GNUTLS_SHUT_WR);
 338
 339   close (fd);
 340   gnutls_deinit (session);
 341
 342   gnutls_anon_free_server_credentials (anoncred);
 343
 344   gnutls_global_deinit ();
 345
 346   if (debug)
 347     success ("server: finished\n");
 348 }
 349
 350 static void start (int server_packet, int client_packet)
 351 {
 352   int fd[2];
 353   int ret;
 354
 355   if (debug)
 356     fprintf(stderr, "\nWill discard %s packet %d\n",
 357       (client_packet!=-1)?"client":"server", (client_packet!=-1)?client_packet:server_packet);
 358
 359   ret = socketpair(AF_LOCAL, SOCK_DGRAM, 0, fd);
 360   if (ret < 0)
 361     {
 362       perror("socketpair");
 363       exit(1);
 364     }
 365
 366   child = fork ();
 367   if (child < 0)
 368     {
 369       perror ("fork");
 370       fail ("fork");
 371       exit(1);
 372     }
 373
 374   if (child)
 375     {
 376       int status;
 377       /* parent */
 378       server (fd[0], server_packet);
 379       wait (&status);
 380       if (WEXITSTATUS(status) != 0)
 381         fail("Child died with status %d\n", WEXITSTATUS(status));
 382     }
 383   else
 384     {
 385       client (fd[1], client_packet);
 386       exit(0);
 387     }
 388 }
 389
 390 void
 391 doit (void)
 392 {
 393   start(-1, 1);
 394   start(-1, 2);
 395   start(-1, 3);
 396   start(-1, 4);
 397
 398   start(1, -1);
 399   start(2, -1);
 400   start(3, -1);
 401   start(4, -1);
 402   start(5, -1);
 403 }
 404
 405 #endif /* _WIN32 */