src/common/session.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2003 Hiroyuki Yamamoto
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include "config.h"
  22 #endif
  23
  24 #include "defs.h"
  25
  26 #include <glib.h>
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <sys/types.h>
  32 #include <unistd.h>
  33 #include <sys/signal.h>
  34 #include <sys/wait.h>
  35 #include <sys/time.h>
  36
  37 #include "session.h"
  38 #include "utils.h"
  39
  40 static gint session_close               (Session        *session);
  41
  42 static gchar *session_recv_msg          (Session        *session);
  43
  44 static guchar *session_read_data        (Session        *session,
  45                                          guint           size);
  46
  47 static gint session_send_data_to_sock           (Session        *session,
  48                                                  const guchar   *data,
  49                                                  guint           size);
  50 static guchar *session_recv_data_from_sock      (Session        *session,
  51                                                  guint           size);
  52
  53 static guchar *session_recv_data_from_sock_unescape     (Session *session,
  54                                                          guint    size,
  55                                                          guint   *actual_size);
  56
  57 gboolean session_parent_input_cb        (GIOChannel     *source,
  58                                          GIOCondition    condition,
  59                                          gpointer        data);
  60
  61 gboolean session_child_input            (Session        *session);
  62
  63
  64 void session_init(Session *session)
  65 {
  66         session->type = 0;
  67         session->sock = NULL;
  68
  69         session->server = NULL;
  70         session->port = 0;
  71         session->state = SESSION_READY;
  72         session->last_access_time = time(NULL);
  73         session->data = NULL;
  74
  75         session->read_ch = NULL;
  76         session->write_ch = NULL;
  77 }
  78
  79 gint session_connect(Session *session, const gchar *server, gushort port)
  80 {
  81         pid_t pid;
  82         gint pipe_fds1[2], pipe_fds2[2];
  83         SockInfo *sock;
  84         gchar *str;
  85
  86         session->server = g_strdup(server);
  87         session->port = port;
  88
  89         if (pipe(pipe_fds1) < 0) {
  90                 perror("pipe");
  91                 return -1;
  92         }
  93         if (pipe(pipe_fds2) < 0) {
  94                 perror("pipe");
  95                 close(pipe_fds1[0]);
  96                 close(pipe_fds1[1]);
  97                 return -1;
  98         }
  99
 100         if ((pid = fork()) < 0) {
 101                 perror("fork");
 102                 return -1;
 103         }
 104
 105         if (pid != 0) {
 106                 session->child_pid = pid;
 107                 session->read_ch = g_io_channel_unix_new(pipe_fds2[0]);
 108                 session->write_ch = g_io_channel_unix_new(pipe_fds1[1]);
 109                 close(pipe_fds1[0]);
 110                 close(pipe_fds2[1]);
 111                 session->read_tag = g_io_add_watch(session->read_ch, G_IO_IN,
 112                                                    session_parent_input_cb,
 113                                                    session);
 114                 return 0;
 115         }
 116
 117         /* child process */
 118
 119         session->read_ch = g_io_channel_unix_new(pipe_fds1[0]);
 120         session->write_ch = g_io_channel_unix_new(pipe_fds2[1]);
 121         close(pipe_fds1[1]);
 122         close(pipe_fds2[0]);
 123
 124         g_print("child: connecting to %s:%d ...\n", server, port);
 125
 126         if ((sock = sock_connect(server, port)) == NULL) {
 127                 session_send_msg(session, SESSION_MSG_ERROR,
 128                                  "can't connect to server.");
 129                 session_close(session);
 130                 _exit(1);
 131         }
 132
 133 #if USE_OPENSSL
 134         if (session->ssl_type == SSL_TUNNEL && !ssl_init_socket(sock)) {
 135                 session_send_msg(session, SESSION_MSG_ERROR,
 136                                  "can't initialize SSL.");
 137                 session_close(session);
 138                 _exit(1);
 139         }
 140 #endif
 141
 142         g_print("child: connected\n");
 143
 144         session->sock = sock;
 145         session->state = SESSION_RECV;
 146
 147         if ((str = sock_getline(sock)) == NULL) {
 148                 session_send_msg(session, SESSION_MSG_ERROR,
 149                                  "can't get server response.");
 150                 session_close(session);
 151                 _exit(1);
 152         }
 153         strretchomp(str);
 154         session_send_msg(session, SESSION_MSG_NORMAL, str);
 155         g_free(str);
 156
 157         while (session_child_input(session) == TRUE)
 158                 ;
 159
 160         session_close(session);
 161
 162         g_print("child: disconnected\n");
 163
 164         _exit(0);
 165 }
 166
 167 gint session_disconnect(Session *session)
 168 {
 169         g_print("%s: session_disconnect()\n", session->child_pid == 0 ? "child" : "parent");
 170         session_send_msg(session, SESSION_MSG_CONTROL, "DISCONNECT");
 171         return 0;
 172 }
 173
 174 void session_destroy(Session *session)
 175 {
 176         g_return_if_fail(session != NULL);
 177         g_return_if_fail(session->destroy != NULL);
 178
 179         g_print("session_destroy()\n");
 180         session_close(session);
 181         session->destroy(session);
 182         g_free(session->server);
 183         g_free(session);
 184 }
 185
 186 void session_set_recv_message_notify(Session *session,
 187                                      RecvMsgNotify notify_func, gpointer data)
 188 {
 189         session->recv_msg_notify = notify_func;
 190         session->recv_msg_notify_data = data;
 191 }
 192
 193 void session_set_recv_data_progressive_notify
 194                                         (Session *session,
 195                                          RecvDataProgressiveNotify notify_func,
 196                                          gpointer data)
 197 {
 198         session->recv_data_progressive_notify = notify_func,
 199         session->recv_data_progressive_notify_data = data;
 200 }
 201
 202 void session_set_recv_data_notify(Session *session, RecvDataNotify notify_func,
 203                                   gpointer data)
 204 {
 205         session->recv_data_notify = notify_func;
 206         session->recv_data_notify_data = data;
 207 }
 208
 209 void session_set_send_data_progressive_notify
 210                                         (Session *session,
 211                                          SendDataProgressiveNotify notify_func,
 212                                          gpointer data)
 213 {
 214         session->send_data_progressive_notify = notify_func;
 215         session->send_data_progressive_notify_data = data;
 216 }
 217
 218 void session_set_send_data_notify(Session *session, SendDataNotify notify_func,
 219                                   gpointer data)
 220 {
 221         session->send_data_notify = notify_func;
 222         session->send_data_notify_data = data;
 223 }
 224
 225 static gint session_close(Session *session)
 226 {
 227         g_return_val_if_fail(session != NULL, -1);
 228
 229         g_print("%s: session_close()\n", session->child_pid == 0 ? "child" : "parent");
 230
 231         if (session->read_tag > 0) {
 232                 g_source_remove(session->read_tag);
 233                 session->read_tag = 0;
 234         }
 235
 236         if (session->read_ch) {
 237                 g_io_channel_close(session->read_ch);
 238                 g_io_channel_unref(session->read_ch);
 239                 session->read_ch = NULL;
 240         }
 241         if (session->write_ch) {
 242                 g_io_channel_close(session->write_ch);
 243                 g_io_channel_unref(session->write_ch);
 244                 session->write_ch = NULL;
 245         }
 246
 247         if (session->sock) {
 248                 sock_close(session->sock);
 249                 session->sock = NULL;
 250                 session->state = SESSION_DISCONNECTED;
 251         }
 252
 253         if (session->child_pid) {
 254                 kill(session->child_pid, SIGTERM);
 255                 waitpid(session->child_pid, NULL, 0);
 256                 session->child_pid = 0;
 257         }
 258
 259         return 0;
 260 }
 261
 262 gint session_send_msg(Session *session, SessionMsgType type, const gchar *msg)
 263 {
 264         gchar *prefix;
 265         gchar *str;
 266         guint size;
 267         guint bytes_written;
 268
 269         switch (type) {
 270         case SESSION_MSG_NORMAL:
 271                 prefix = "MESSAGE"; break;
 272         case SESSION_MSG_SEND_DATA:
 273                 prefix = "SENDDATA"; break;
 274         case SESSION_MSG_RECV_DATA:
 275                 prefix = "RECVDATA"; break;
 276         case SESSION_MSG_CONTROL:
 277                 prefix = "CONTROL"; break;
 278         case SESSION_MSG_ERROR:
 279                 prefix = "ERROR"; break;
 280         default:
 281                 return -1;
 282         }
 283
 284         str = g_strdup_printf("%s %s\n", prefix, msg);
 285         /* g_print("%s: sending message: %s", session->child_pid == 0 ? "child" : "parent", str); */
 286         size = strlen(str);
 287
 288         while (size > 0) {
 289                 if (g_io_channel_write(session->write_ch, str, size,
 290                                        &bytes_written)
 291                     != G_IO_ERROR_NONE || bytes_written == 0) {
 292                         g_warning("%s: sending message failed.\n",
 293                                   session->child_pid == 0 ? "child" : "parent");
 294                         return -1;
 295                 }
 296                 size -= bytes_written;
 297         }
 298
 299         return 0;
 300 }
 301
 302 static gchar *session_recv_msg(Session *session)
 303 {
 304         gchar buf[BUFFSIZE];
 305         gchar *str = NULL;
 306         guint size = 1;
 307         guint bytes_read;
 308
 309         for (;;) {
 310                 if (g_io_channel_read(session->read_ch, buf, sizeof(buf) - 1,
 311                                       &bytes_read)
 312                     != G_IO_ERROR_NONE || bytes_read == 0) {
 313                         g_warning("%s: receiving message failed.\n",
 314                                   session->child_pid == 0 ? "child" : "parent");
 315                         g_free(str);
 316                         str = NULL;
 317                         break;
 318                 }
 319
 320                 size += bytes_read;
 321                 buf[bytes_read] = '\0';
 322
 323                 if (!str)
 324                         str = g_strdup(buf);
 325                 else {
 326                         str = g_realloc(str, size);
 327                         strcat(str, buf);
 328                 }
 329                 if (str[size - 2] == '\n') {
 330                         str[size - 2] = '\0';
 331
 332                         g_print("%s: received message: %s\n", session->child_pid == 0 ? "child" : "parent", str);
 333
 334                         break;
 335                 }
 336         }
 337
 338         return str;
 339 }
 340
 341 #if USE_OPENSSL
 342 gint session_start_tls(Session *session)
 343 {
 344         gchar *ctl_msg;
 345
 346         session_send_msg(session, SESSION_MSG_CONTROL, "STARTTLS");
 347         ctl_msg = session_recv_msg(session);
 348         if (!ctl_msg || strcmp(ctl_msg, "CONTROL STARTTLSOK") != 0) {
 349                 g_free(ctl_msg);
 350                 return -1;
 351         }
 352         g_free(ctl_msg);
 353
 354         return 0;
 355 }
 356 #endif
 357
 358 gint session_send_data(Session *session, const guchar *data, guint size)
 359 {
 360         gchar *msg;
 361         guint bytes_written;
 362         GIOError err;
 363
 364         session_send_msg(session, SESSION_MSG_SEND_DATA, itos(size));
 365         if ((msg = session_recv_msg(session)) == NULL)
 366                 return -1;
 367         g_free(msg);
 368
 369         while (size > 0) {
 370                 if ((err = g_io_channel_write(session->write_ch, (guchar *)data,
 371                                               size, &bytes_written))
 372                     != G_IO_ERROR_NONE || bytes_written == 0) {
 373                         g_warning("%s: sending data failed: %d\n",
 374                                   session->child_pid == 0 ? "child" : "parent",
 375                                   err);
 376                         return -1;
 377                 }
 378                 size -= bytes_written;
 379                 g_print("%s: sent %d bytes of data\n", session->child_pid == 0 ? "child" : "parent", bytes_written);
 380         }
 381
 382         return 0;
 383 }
 384
 385 gint session_recv_data(Session *session, guint size, gboolean unescape_dot)
 386 {
 387         if (unescape_dot) {
 388                 gchar buf[BUFFSIZE];
 389
 390                 g_snprintf(buf, sizeof(buf), "%d UNESCAPE", size);
 391                 session_send_msg(session, SESSION_MSG_RECV_DATA, buf);
 392         } else
 393                 session_send_msg(session, SESSION_MSG_RECV_DATA, itos(size));
 394         return 0;
 395 }
 396
 397 static guchar *session_read_data(Session *session, guint size)
 398 {
 399         guchar *data;
 400         guchar *cur;
 401         guint bytes_read;
 402         GIOError err;
 403
 404         cur = data = g_malloc(size);
 405
 406         while (size > 0) {
 407                 if ((err = g_io_channel_read(session->read_ch, cur, size,
 408                                              &bytes_read))
 409                     != G_IO_ERROR_NONE || bytes_read == 0) {
 410                         g_warning("%s: reading data failed: %d\n",
 411                                   session->child_pid == 0 ? "child" : "parent",
 412                                   err);
 413                         g_free(data);
 414                         return NULL;
 415                 }
 416                 size -= bytes_read;
 417                 cur += bytes_read;
 418                 g_print("%s: received %d bytes of data\n", session->child_pid == 0 ? "child" : "parent", bytes_read);
 419         }
 420
 421         return data;
 422 }
 423
 424 #define MAX_CHUNK_SIZE 4096
 425
 426 static gint session_send_data_to_sock(Session *session, const guchar *data,
 427                                       guint size)
 428 {
 429         const guchar *cur = data;
 430         gint bytes_written;
 431         gint total_write_len = 0;
 432         guint left = size;
 433         gchar buf[BUFFSIZE];
 434         gchar *msg;
 435         struct timeval tv_prev, tv_cur;
 436
 437         gettimeofday(&tv_prev, NULL);
 438
 439         while (1) {
 440                 bytes_written = sock_write(session->sock, cur,
 441                                            MIN(left, MAX_CHUNK_SIZE));
 442                 if (bytes_written <= 0)
 443                         return -1;
 444                 left -= bytes_written;
 445                 cur += bytes_written;
 446                 total_write_len += bytes_written;
 447                 if (left == 0)
 448                         break;
 449
 450                 gettimeofday(&tv_cur, NULL);
 451                 if (tv_cur.tv_sec - tv_prev.tv_sec > 0 ||
 452                     tv_cur.tv_usec - tv_prev.tv_usec > UI_REFRESH_INTERVAL) {
 453                         g_snprintf(buf, sizeof(buf), "DATASENDINPROG %d %d",
 454                                    total_write_len, size);
 455                         session_send_msg(session, SESSION_MSG_CONTROL, buf);
 456                         if ((msg = session_recv_msg(session)) == NULL)
 457                                 return -1;
 458                         g_free(msg);
 459                         gettimeofday(&tv_prev, NULL);
 460                 }
 461         }
 462
 463         return 0;
 464 }
 465
 466 static guchar *session_recv_data_from_sock(Session *session, guint size)
 467 {
 468         guchar *data;
 469         guchar *cur;
 470         gint bytes_read;
 471         gint total_read_len = 0;
 472         guint left = size;
 473         gchar buf[BUFFSIZE];
 474         gchar *msg;
 475         struct timeval tv_prev, tv_cur;
 476
 477         gettimeofday(&tv_prev, NULL);
 478
 479         cur = data = g_malloc(size);
 480
 481         while (1) {
 482                 bytes_read = sock_read(session->sock, cur, left);
 483                 if (bytes_read <= 0) {
 484                         g_free(data);
 485                         return NULL;
 486                 }
 487                 g_print("child: received %d bytes of data from sock\n", bytes_read);
 488                 left -= bytes_read;
 489                 cur += bytes_read;
 490                 total_read_len += bytes_read;
 491                 if (left == 0)
 492                         break;
 493
 494                 gettimeofday(&tv_cur, NULL);
 495                 if (tv_cur.tv_sec - tv_prev.tv_sec > 0 ||
 496                     tv_cur.tv_usec - tv_prev.tv_usec > UI_REFRESH_INTERVAL) {
 497                         g_snprintf(buf, sizeof(buf), "DATARECVINPROG %d %d",
 498                                    total_read_len, size);
 499                         session_send_msg(session, SESSION_MSG_CONTROL, buf);
 500                         if ((msg = session_recv_msg(session)) == NULL) {
 501                                 g_free(data);
 502                                 return NULL;
 503                         }
 504                         g_free(msg);
 505                         gettimeofday(&tv_prev, NULL);
 506                 }
 507         }
 508
 509         return data;
 510 }
 511
 512 static guchar *session_recv_data_from_sock_unescape(Session *session,
 513                                                     guint size,
 514                                                     guint *actual_size)
 515 {
 516         GString *data;
 517         guchar *ret_data;
 518         gint bytes_read;
 519         gchar buf[BUFFSIZE];
 520         gchar *msg;
 521         struct timeval tv_prev, tv_cur;
 522
 523         gettimeofday(&tv_prev, NULL);
 524
 525         data = g_string_sized_new(size + 1);
 526         *actual_size = 0;
 527
 528         while (1) {
 529                 bytes_read = sock_gets(session->sock, buf, sizeof(buf));
 530                 if (bytes_read <= 0) {
 531                         g_string_free(data, TRUE);
 532                         return NULL;
 533                 }
 534
 535                 if (buf[0] == '.' && buf[1] == '\r' && buf[2] == '\n')
 536                         break;
 537                 if (buf[0] == '.' && buf[1] == '.')
 538                         g_string_append(data, buf + 1);
 539                 else
 540                         g_string_append(data, buf);
 541
 542                 gettimeofday(&tv_cur, NULL);
 543                 if (tv_cur.tv_sec - tv_prev.tv_sec > 0 ||
 544                     tv_cur.tv_usec - tv_prev.tv_usec > UI_REFRESH_INTERVAL) {
 545                         g_snprintf(buf, sizeof(buf), "DATARECVINPROG %d %d",
 546                                    data->len, MAX(data->len, size));
 547                         session_send_msg(session, SESSION_MSG_CONTROL, buf);
 548                         if ((msg = session_recv_msg(session)) == NULL) {
 549                                 g_string_free(data, TRUE);
 550                                 return NULL;
 551                         }
 552                         g_free(msg);
 553                         gettimeofday(&tv_prev, NULL);
 554                 }
 555         }
 556
 557         ret_data = data->str;
 558         *actual_size = data->len;
 559         g_string_free(data, FALSE);
 560
 561         return ret_data;
 562 }
 563
 564 static SessionMsgType session_get_msg_type(const gchar *str)
 565 {
 566         if (!strncmp(str, "MESSAGE ", 8))
 567                 return SESSION_MSG_NORMAL;
 568         else if (!strncmp(str, "SENDDATA ", 9))
 569                 return SESSION_MSG_SEND_DATA;
 570         else if (!strncmp(str, "RECVDATA ", 9))
 571                 return SESSION_MSG_RECV_DATA;
 572         else if (!strncmp(str, "CONTROL ", 8))
 573                 return SESSION_MSG_CONTROL;
 574         else if (!strncmp(str, "ERROR ", 6))
 575                 return SESSION_MSG_ERROR;
 576         else
 577                 return SESSION_MSG_UNKNOWN;
 578 }
 579
 580 gboolean session_parent_input_cb(GIOChannel *source, GIOCondition condition,
 581                                  gpointer data)
 582 {
 583         Session *session = SESSION(data);
 584         gchar *msg;
 585         gchar *msg_data;
 586         gint len;
 587         gint total;
 588         guchar *recv_data;
 589         guint size;
 590         gint ret;
 591
 592         if ((msg = session_recv_msg(session)) == NULL) {
 593                 session->state = SESSION_ERROR;
 594                 return FALSE;
 595         }
 596
 597         switch (session_get_msg_type(msg)) {
 598         case SESSION_MSG_NORMAL:
 599                 msg_data = msg + strlen("MESSAGE ");
 600                 ret = session->recv_msg(session, msg_data);
 601                 session->recv_msg_notify(session, msg_data,
 602                                          session->recv_msg_notify_data);
 603                 if (ret > 0)
 604                         session_send_msg(session, SESSION_MSG_CONTROL,
 605                                          "CONTINUE");
 606                 else if (ret < 0) {
 607                         session->state = SESSION_ERROR;
 608                         g_free(msg);
 609                         return FALSE;
 610                 }
 611                 break;
 612         case SESSION_MSG_SEND_DATA:
 613                 msg_data = msg + strlen("SENDDATA ");
 614                 size = atoi(msg_data);
 615                 session_send_msg(session, SESSION_MSG_CONTROL, "ACCEPTDATA");
 616                 recv_data = session_read_data(session, size);
 617                 if (!recv_data) {
 618                         session->state = SESSION_ERROR;
 619                         g_free(msg);
 620                         return FALSE;
 621                 }
 622                 ret = session->recv_data_finished(session, recv_data, size);
 623                 g_free(recv_data);
 624                 session->recv_data_notify(session, size,
 625                                           session->recv_data_notify_data);
 626                 if (ret > 0)
 627                         session_send_msg(session, SESSION_MSG_CONTROL,
 628                                          "CONTINUE");
 629                 else if (ret < 0) {
 630                         session->state = SESSION_ERROR;
 631                         g_free(msg);
 632                         return FALSE;
 633                 }
 634                 break;
 635         case SESSION_MSG_RECV_DATA:
 636                 break;
 637         case SESSION_MSG_CONTROL:
 638                 msg_data = msg + strlen("CONTROL ");
 639                 if (!strncmp(msg_data, "DATARECVINPROG ", 15)) {
 640                         ret = sscanf(msg_data,
 641                                      "DATARECVINPROG %d %d", &len, &total);
 642                         if (ret != 2) {
 643                                 g_warning("wrong control message: %s\n", msg);
 644                                 session->state = SESSION_ERROR;
 645                                 g_free(msg);
 646                                 return FALSE;
 647                         }
 648                         session_send_msg(session, SESSION_MSG_CONTROL,
 649                                          "CONTINUE");
 650                         session->recv_data_progressive_notify
 651                                 (session, len, total,
 652                                  session->recv_data_progressive_notify_data);
 653                 } else if (!strncmp(msg_data, "DATASENDINPROG ", 15)) {
 654                         ret = sscanf(msg_data,
 655                                      "DATASENDINPROG %d %d", &len, &total);
 656                         if (ret != 2) {
 657                                 g_warning("wrong control message: %s\n", msg);
 658                                 session->state = SESSION_ERROR;
 659                                 g_free(msg);
 660                                 return FALSE;
 661                         }
 662                         session_send_msg(session, SESSION_MSG_CONTROL,
 663                                          "CONTINUE");
 664                         session->send_data_progressive_notify
 665                                 (session, len, total,
 666                                  session->send_data_progressive_notify_data);
 667                 } else if (!strncmp(msg_data, "DATASENT ", 9)) {
 668                         len = atoi(msg_data + 9);
 669                         ret = session->send_data_finished(session, len);
 670                         session->send_data_notify
 671                                 (session, len, session->send_data_notify_data);
 672                 } else if (!strcmp(msg_data, "DISCONNECTED")) {
 673                         session->state = SESSION_DISCONNECTED;
 674                         g_free(msg);
 675                         return FALSE;
 676                 } else {
 677                         g_warning("wrong control message: %s\n", msg);
 678                         session->state = SESSION_ERROR;
 679                         g_free(msg);
 680                         return FALSE;
 681                 }
 682                 break;
 683         case SESSION_MSG_ERROR:
 684         default:
 685                 g_warning("error from child: %s\n", msg + strlen("ERROR "));
 686                 session->state = SESSION_ERROR;
 687                 g_free(msg);
 688                 return FALSE;
 689         }
 690
 691         g_free(msg);
 692         return TRUE;
 693 }
 694
 695 gboolean session_child_input(Session *session)
 696 {
 697         gchar buf[BUFFSIZE];
 698         gchar *msg;
 699         gchar *msg_data;
 700         gchar *str;
 701         guchar *send_data;
 702         guchar *recv_data;
 703         guint size;
 704         guint actual_size;
 705
 706         if ((msg = session_recv_msg(session)) == NULL) {
 707                 session_send_msg(session, SESSION_MSG_ERROR,
 708                                  "receiving message failed.");
 709                 session_close(session);
 710                 session->state = SESSION_ERROR;
 711                 return FALSE;
 712         }
 713
 714         switch (session_get_msg_type(msg)) {
 715         case SESSION_MSG_NORMAL:
 716                 msg_data = msg + strlen("MESSAGE ");
 717                 session->state = SESSION_SEND;
 718                 sock_puts(session->sock, msg_data);
 719                 session->state = SESSION_RECV;
 720                 str = sock_getline(session->sock);
 721                 if (!str) {
 722                         session_send_msg(session, SESSION_MSG_ERROR,
 723                                          "receiving message failed.");
 724                         session_close(session);
 725                         session->state = SESSION_ERROR;
 726                         g_free(msg);
 727                         return FALSE;
 728                 }
 729                 strretchomp(str);
 730                 session_send_msg(session, SESSION_MSG_NORMAL, str);
 731                 g_free(str);
 732                 break;
 733         case SESSION_MSG_SEND_DATA:
 734                 msg_data = msg + strlen("SENDDATA ");
 735                 size = atoi(msg_data);
 736                 session_send_msg(session, SESSION_MSG_CONTROL, "ACCEPTDATA");
 737                 send_data = session_read_data(session, size);
 738                 if (!send_data) {
 739                         session_send_msg(session, SESSION_MSG_ERROR,
 740                                          "sending data failed.");
 741                         session_close(session);
 742                         session->state = SESSION_ERROR;
 743                         g_free(msg);
 744                         return FALSE;
 745                 }
 746                 session->state = SESSION_SEND;
 747                 if (session_send_data_to_sock(session, send_data, size) < 0) {
 748                         session_send_msg(session, SESSION_MSG_ERROR,
 749                                          "sending data failed.");
 750                         session_close(session);
 751                         session->state = SESSION_ERROR;
 752                         g_free(send_data);
 753                         g_free(msg);
 754                         return FALSE;
 755                 }
 756                 g_free(send_data);
 757                 g_snprintf(buf, sizeof(buf), "DATASENT %d", size);
 758                 session_send_msg(session, SESSION_MSG_CONTROL, buf);
 759                 break;
 760         case SESSION_MSG_RECV_DATA:
 761                 msg_data = msg + strlen("RECVDATA ");
 762                 size = atoi(msg_data);
 763                 session->state = SESSION_RECV;
 764                 if (strstr(msg_data, "UNESCAPE") != NULL) {
 765                         recv_data = session_recv_data_from_sock_unescape
 766                                 (session, size, &actual_size);
 767                         size = actual_size;
 768                 } else
 769                         recv_data = session_recv_data_from_sock(session, size);
 770                 if (!recv_data) {
 771                         session_send_msg(session, SESSION_MSG_ERROR,
 772                                          "receiving data failed.");
 773                         session_close(session);
 774                         session->state = SESSION_ERROR;
 775                         g_free(msg);
 776                         return FALSE;
 777                 }
 778                 if (session_send_data(session, recv_data, size) < 0) {
 779                         session_close(session);
 780                         session->state = SESSION_ERROR;
 781                         g_free(recv_data);
 782                         g_free(msg);
 783                         return FALSE;
 784                 }
 785                 g_free(recv_data);
 786                 break;
 787         case SESSION_MSG_CONTROL:
 788                 msg_data = msg + strlen("CONTROL ");
 789                 if (!strcmp(msg_data, "CONTINUE")) {
 790                         session->state = SESSION_RECV;
 791                         str = sock_getline(session->sock);
 792                         if (!str) {
 793                                 session_send_msg(session, SESSION_MSG_ERROR,
 794                                                  "receiving message failed.");
 795                                 session_close(session);
 796                                 session->state = SESSION_ERROR;
 797                                 g_free(msg);
 798                                 return FALSE;
 799                         }
 800                         strretchomp(str);
 801                         session_send_msg(session, SESSION_MSG_NORMAL, str);
 802                         g_free(str);
 803                         break;
 804 #if USE_OPENSSL
 805                 } else if (!strcmp(msg_data, "STARTTLS")) {
 806                         if (!ssl_init_socket_with_method(session->sock,
 807                                                          SSL_METHOD_TLSv1)) {
 808                                 session_send_msg(session, SESSION_MSG_ERROR,
 809                                                  "can't start TLS session.");
 810                                 session_close(session);
 811                                 session->state = SESSION_ERROR;
 812                                 g_free(msg);
 813                                 return FALSE;
 814                         }
 815                         session_send_msg(session, SESSION_MSG_CONTROL,
 816                                          "STARTTLSOK");
 817                         break;
 818 #endif
 819                 } else if (!strcmp(msg_data, "DISCONNECT")) {
 820                         sock_close(session->sock);
 821                         session->sock = NULL;
 822                         session->state = SESSION_DISCONNECTED;
 823                         session_send_msg(session, SESSION_MSG_CONTROL,
 824                                          "DISCONNECTED");
 825                         g_free(msg);
 826                         return FALSE;
 827                 } else {
 828                         session_send_msg(session, SESSION_MSG_ERROR,
 829                                          "wrong control message.");
 830                         session_close(session);
 831                         session->state = SESSION_ERROR;
 832                         g_free(msg);
 833                         return FALSE;
 834                 }
 835                 break;
 836         case SESSION_MSG_ERROR:
 837         default:
 838                 session_send_msg(session, SESSION_MSG_ERROR,
 839                                  "error received from parent.");
 840                 session_close(session);
 841                 session->state = SESSION_ERROR;
 842                 g_free(msg);
 843                 return FALSE;
 844         }
 845
 846         g_free(msg);
 847         return TRUE;
 848 }