1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * Created: Sun Sep 10 00:30:37 1995 ylo 6 * Server main loop for handling the interactive session. 7 */ 8 /* 9 * SSH2 support by Markus Friedl. 10 * Copyright (c) 2000 Markus Friedl. All rights reserved. 11 */ 12 13 #include "includes.h" 14 #include "xmalloc.h" 15 #include "ssh.h" 16 #include "packet.h" 17 #include "buffer.h" 18 #include "servconf.h" 19 #include "pty.h" 20 #include "channels.h" 21 22 #include "compat.h" 23 #include "ssh2.h" 24 #include "session.h" 25 #include "dispatch.h" 26 27 static Buffer stdin_buffer; /* Buffer for stdin data. */ 28 static Buffer stdout_buffer; /* Buffer for stdout data. */ 29 static Buffer stderr_buffer; /* Buffer for stderr data. */ 30 static int fdin; /* Descriptor for stdin (for writing) */ 31 static int fdout; /* Descriptor for stdout (for reading); 32 May be same number as fdin. */ 33 static int fderr; /* Descriptor for stderr. May be -1. */ 34 static long stdin_bytes = 0; /* Number of bytes written to stdin. */ 35 static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ 36 static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ 37 static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ 38 static int stdin_eof = 0; /* EOF message received from client. */ 39 static int fdout_eof = 0; /* EOF encountered reading from fdout. */ 40 static int fderr_eof = 0; /* EOF encountered readung from fderr. */ 41 static int connection_in; /* Connection to client (input). */ 42 static int connection_out; /* Connection to client (output). */ 43 static unsigned int buffer_high;/* "Soft" max buffer size. */ 44 static int max_fd; /* Max file descriptor number for select(). */ 45 46 /* 47 * This SIGCHLD kludge is used to detect when the child exits. The server 48 * will exit after that, as soon as forwarded connections have terminated. 49 */ 50 51 static pid_t child_pid; /* Pid of the child. */ 52 static volatile int child_terminated; /* The child has terminated. */ 53 static volatile int child_wait_status; /* Status from wait(). */ 54 55 void server_init_dispatch(void); 56 57 void 58 sigchld_handler(int sig) 59 { 60 int save_errno = errno; 61 pid_t wait_pid; 62 63 debug("Received SIGCHLD."); 64 wait_pid = wait((int *) &child_wait_status); 65 if (wait_pid != -1) { 66 if (wait_pid != child_pid) 67 error("Strange, got SIGCHLD and wait returned pid %d but child is %d", 68 wait_pid, child_pid); 69 if (WIFEXITED(child_wait_status) || 70 WIFSIGNALED(child_wait_status)) 71 child_terminated = 1; 72 } 73 signal(SIGCHLD, sigchld_handler); 74 errno = save_errno; 75 } 76 void 77 sigchld_handler2(int sig) 78 { 79 int save_errno = errno; 80 debug("Received SIGCHLD."); 81 child_terminated = 1; 82 signal(SIGCHLD, sigchld_handler2); 83 errno = save_errno; 84 } 85 86 /* 87 * Make packets from buffered stderr data, and buffer it for sending 88 * to the client. 89 */ 90 void 91 make_packets_from_stderr_data() 92 { 93 int len; 94 95 /* Send buffered stderr data to the client. */ 96 while (buffer_len(&stderr_buffer) > 0 && 97 packet_not_very_much_data_to_write()) { 98 len = buffer_len(&stderr_buffer); 99 if (packet_is_interactive()) { 100 if (len > 512) 101 len = 512; 102 } else { 103 /* Keep the packets at reasonable size. */ 104 if (len > packet_get_maxsize()) 105 len = packet_get_maxsize(); 106 } 107 packet_start(SSH_SMSG_STDERR_DATA); 108 packet_put_string(buffer_ptr(&stderr_buffer), len); 109 packet_send(); 110 buffer_consume(&stderr_buffer, len); 111 stderr_bytes += len; 112 } 113 } 114 115 /* 116 * Make packets from buffered stdout data, and buffer it for sending to the 117 * client. 118 */ 119 void 120 make_packets_from_stdout_data() 121 { 122 int len; 123 124 /* Send buffered stdout data to the client. */ 125 while (buffer_len(&stdout_buffer) > 0 && 126 packet_not_very_much_data_to_write()) { 127 len = buffer_len(&stdout_buffer); 128 if (packet_is_interactive()) { 129 if (len > 512) 130 len = 512; 131 } else { 132 /* Keep the packets at reasonable size. */ 133 if (len > packet_get_maxsize()) 134 len = packet_get_maxsize(); 135 } 136 packet_start(SSH_SMSG_STDOUT_DATA); 137 packet_put_string(buffer_ptr(&stdout_buffer), len); 138 packet_send(); 139 buffer_consume(&stdout_buffer, len); 140 stdout_bytes += len; 141 } 142 } 143 144 /* 145 * Sleep in select() until we can do something. This will initialize the 146 * select masks. Upon return, the masks will indicate which descriptors 147 * have data or can accept data. Optionally, a maximum time can be specified 148 * for the duration of the wait (0 = infinite). 149 */ 150 void 151 wait_until_can_do_something(fd_set * readset, fd_set * writeset, 152 unsigned int max_time_milliseconds) 153 { 154 struct timeval tv, *tvp; 155 int ret; 156 157 /* When select fails we restart from here. */ 158 retry_select: 159 160 /* Initialize select() masks. */ 161 FD_ZERO(readset); 162 FD_ZERO(writeset); 163 164 if (compat20) { 165 /* wrong: bad condition XXX */ 166 if (channel_not_very_much_buffered_data()) 167 FD_SET(connection_in, readset); 168 } else { 169 /* 170 * Read packets from the client unless we have too much 171 * buffered stdin or channel data. 172 */ 173 if (buffer_len(&stdin_buffer) < buffer_high && 174 channel_not_very_much_buffered_data()) 175 FD_SET(connection_in, readset); 176 /* 177 * If there is not too much data already buffered going to 178 * the client, try to get some more data from the program. 179 */ 180 if (packet_not_very_much_data_to_write()) { 181 if (!fdout_eof) 182 FD_SET(fdout, readset); 183 if (!fderr_eof) 184 FD_SET(fderr, readset); 185 } 186 /* 187 * If we have buffered data, try to write some of that data 188 * to the program. 189 */ 190 if (fdin != -1 && buffer_len(&stdin_buffer) > 0) 191 FD_SET(fdin, writeset); 192 } 193 /* Set masks for channel descriptors. */ 194 channel_prepare_select(readset, writeset); 195 196 /* 197 * If we have buffered packet data going to the client, mark that 198 * descriptor. 199 */ 200 if (packet_have_data_to_write()) 201 FD_SET(connection_out, writeset); 202 203 /* Update the maximum descriptor number if appropriate. */ 204 if (channel_max_fd() > max_fd) 205 max_fd = channel_max_fd(); 206 207 /* 208 * If child has terminated and there is enough buffer space to read 209 * from it, then read as much as is available and exit. 210 */ 211 if (child_terminated && packet_not_very_much_data_to_write()) 212 if (max_time_milliseconds == 0) 213 max_time_milliseconds = 100; 214 215 if (max_time_milliseconds == 0) 216 tvp = NULL; 217 else { 218 tv.tv_sec = max_time_milliseconds / 1000; 219 tv.tv_usec = 1000 * (max_time_milliseconds % 1000); 220 tvp = &tv; 221 } 222 if (tvp!=NULL) 223 debug("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds); 224 225 /* Wait for something to happen, or the timeout to expire. */ 226 ret = select(max_fd + 1, readset, writeset, NULL, tvp); 227 228 if (ret < 0) { 229 if (errno != EINTR) 230 error("select: %.100s", strerror(errno)); 231 else 232 goto retry_select; 233 } 234 } 235 236 /* 237 * Processes input from the client and the program. Input data is stored 238 * in buffers and processed later. 239 */ 240 void 241 process_input(fd_set * readset) 242 { 243 int len; 244 char buf[16384]; 245 246 /* Read and buffer any input data from the client. */ 247 if (FD_ISSET(connection_in, readset)) { 248 len = read(connection_in, buf, sizeof(buf)); 249 if (len == 0) { 250 verbose("Connection closed by remote host."); 251 fatal_cleanup(); 252 } else if (len < 0) { 253 if (errno != EINTR && errno != EAGAIN) { 254 verbose("Read error from remote host: %.100s", strerror(errno)); 255 fatal_cleanup(); 256 } 257 } else { 258 /* Buffer any received data. */ 259 packet_process_incoming(buf, len); 260 } 261 } 262 if (compat20) 263 return; 264 265 /* Read and buffer any available stdout data from the program. */ 266 if (!fdout_eof && FD_ISSET(fdout, readset)) { 267 len = read(fdout, buf, sizeof(buf)); 268 if (len < 0 && (errno == EINTR || errno == EAGAIN)) { 269 /* do nothing */ 270 } else if (len <= 0) { 271 fdout_eof = 1; 272 } else { 273 buffer_append(&stdout_buffer, buf, len); 274 fdout_bytes += len; 275 } 276 } 277 /* Read and buffer any available stderr data from the program. */ 278 if (!fderr_eof && FD_ISSET(fderr, readset)) { 279 len = read(fderr, buf, sizeof(buf)); 280 if (len < 0 && (errno == EINTR || errno == EAGAIN)) { 281 /* do nothing */ 282 } else if (len <= 0) { 283 fderr_eof = 1; 284 } else { 285 buffer_append(&stderr_buffer, buf, len); 286 } 287 } 288 } 289 290 /* 291 * Sends data from internal buffers to client program stdin. 292 */ 293 void 294 process_output(fd_set * writeset) 295 { 296 int len; 297 298 /* Write buffered data to program stdin. */ 299 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { 300 len = write(fdin, buffer_ptr(&stdin_buffer), 301 buffer_len(&stdin_buffer)); 302 if (len < 0 && (errno == EINTR || errno == EAGAIN)) { 303 /* do nothing */ 304 } else if (len <= 0) { 305 #ifdef USE_PIPES 306 close(fdin); 307 #else 308 if (fdin != fdout) 309 close(fdin); 310 else 311 shutdown(fdin, SHUT_WR); /* We will no longer send. */ 312 #endif 313 fdin = -1; 314 } else { 315 /* Successful write. Consume the data from the buffer. */ 316 buffer_consume(&stdin_buffer, len); 317 /* Update the count of bytes written to the program. */ 318 stdin_bytes += len; 319 } 320 } 321 /* Send any buffered packet data to the client. */ 322 if (FD_ISSET(connection_out, writeset)) 323 packet_write_poll(); 324 } 325 326 /* 327 * Wait until all buffered output has been sent to the client. 328 * This is used when the program terminates. 329 */ 330 void 331 drain_output() 332 { 333 /* Send any buffered stdout data to the client. */ 334 if (buffer_len(&stdout_buffer) > 0) { 335 packet_start(SSH_SMSG_STDOUT_DATA); 336 packet_put_string(buffer_ptr(&stdout_buffer), 337 buffer_len(&stdout_buffer)); 338 packet_send(); 339 /* Update the count of sent bytes. */ 340 stdout_bytes += buffer_len(&stdout_buffer); 341 } 342 /* Send any buffered stderr data to the client. */ 343 if (buffer_len(&stderr_buffer) > 0) { 344 packet_start(SSH_SMSG_STDERR_DATA); 345 packet_put_string(buffer_ptr(&stderr_buffer), 346 buffer_len(&stderr_buffer)); 347 packet_send(); 348 /* Update the count of sent bytes. */ 349 stderr_bytes += buffer_len(&stderr_buffer); 350 } 351 /* Wait until all buffered data has been written to the client. */ 352 packet_write_wait(); 353 } 354 355 void 356 process_buffered_input_packets() 357 { 358 dispatch_run(DISPATCH_NONBLOCK, NULL); 359 } 360 361 /* 362 * Performs the interactive session. This handles data transmission between 363 * the client and the program. Note that the notion of stdin, stdout, and 364 * stderr in this function is sort of reversed: this function writes to 365 * stdin (of the child program), and reads from stdout and stderr (of the 366 * child program). 367 */ 368 void 369 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) 370 { 371 fd_set readset, writeset; 372 int wait_status; /* Status returned by wait(). */ 373 pid_t wait_pid; /* pid returned by wait(). */ 374 int waiting_termination = 0; /* Have displayed waiting close message. */ 375 unsigned int max_time_milliseconds; 376 unsigned int previous_stdout_buffer_bytes; 377 unsigned int stdout_buffer_bytes; 378 int type; 379 380 debug("Entering interactive session."); 381 382 /* Initialize the SIGCHLD kludge. */ 383 child_pid = pid; 384 child_terminated = 0; 385 signal(SIGCHLD, sigchld_handler); 386 387 /* Initialize our global variables. */ 388 fdin = fdin_arg; 389 fdout = fdout_arg; 390 fderr = fderr_arg; 391 392 /* nonblocking IO */ 393 set_nonblock(fdin); 394 set_nonblock(fdout); 395 /* we don't have stderr for interactive terminal sessions, see below */ 396 if (fderr != -1) 397 set_nonblock(fderr); 398 399 connection_in = packet_get_connection_in(); 400 connection_out = packet_get_connection_out(); 401 402 previous_stdout_buffer_bytes = 0; 403 404 /* Set approximate I/O buffer size. */ 405 if (packet_is_interactive()) 406 buffer_high = 4096; 407 else 408 buffer_high = 64 * 1024; 409 410 /* Initialize max_fd to the maximum of the known file descriptors. */ 411 max_fd = fdin; 412 if (fdout > max_fd) 413 max_fd = fdout; 414 if (fderr != -1 && fderr > max_fd) 415 max_fd = fderr; 416 if (connection_in > max_fd) 417 max_fd = connection_in; 418 if (connection_out > max_fd) 419 max_fd = connection_out; 420 421 /* Initialize Initialize buffers. */ 422 buffer_init(&stdin_buffer); 423 buffer_init(&stdout_buffer); 424 buffer_init(&stderr_buffer); 425 426 /* 427 * If we have no separate fderr (which is the case when we have a pty 428 * - there we cannot make difference between data sent to stdout and 429 * stderr), indicate that we have seen an EOF from stderr. This way 430 * we don\'t need to check the descriptor everywhere. 431 */ 432 if (fderr == -1) 433 fderr_eof = 1; 434 435 server_init_dispatch(); 436 437 /* Main loop of the server for the interactive session mode. */ 438 for (;;) { 439 440 /* Process buffered packets from the client. */ 441 process_buffered_input_packets(); 442 443 /* 444 * If we have received eof, and there is no more pending 445 * input data, cause a real eof by closing fdin. 446 */ 447 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { 448 #ifdef USE_PIPES 449 close(fdin); 450 #else 451 if (fdin != fdout) 452 close(fdin); 453 else 454 shutdown(fdin, SHUT_WR); /* We will no longer send. */ 455 #endif 456 fdin = -1; 457 } 458 /* Make packets from buffered stderr data to send to the client. */ 459 make_packets_from_stderr_data(); 460 461 /* 462 * Make packets from buffered stdout data to send to the 463 * client. If there is very little to send, this arranges to 464 * not send them now, but to wait a short while to see if we 465 * are getting more data. This is necessary, as some systems 466 * wake up readers from a pty after each separate character. 467 */ 468 max_time_milliseconds = 0; 469 stdout_buffer_bytes = buffer_len(&stdout_buffer); 470 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && 471 stdout_buffer_bytes != previous_stdout_buffer_bytes) { 472 /* try again after a while */ 473 max_time_milliseconds = 10; 474 } else { 475 /* Send it now. */ 476 make_packets_from_stdout_data(); 477 } 478 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); 479 480 /* Send channel data to the client. */ 481 if (packet_not_very_much_data_to_write()) 482 channel_output_poll(); 483 484 /* 485 * Bail out of the loop if the program has closed its output 486 * descriptors, and we have no more data to send to the 487 * client, and there is no pending buffered data. 488 */ 489 if (fdout_eof && fderr_eof && !packet_have_data_to_write() && 490 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { 491 if (!channel_still_open()) 492 break; 493 if (!waiting_termination) { 494 const char *s = "Waiting for forwarded connections to terminate...\r\n"; 495 char *cp; 496 waiting_termination = 1; 497 buffer_append(&stderr_buffer, s, strlen(s)); 498 499 /* Display list of open channels. */ 500 cp = channel_open_message(); 501 buffer_append(&stderr_buffer, cp, strlen(cp)); 502 xfree(cp); 503 } 504 } 505 /* Sleep in select() until we can do something. */ 506 wait_until_can_do_something(&readset, &writeset, 507 max_time_milliseconds); 508 509 /* Process any channel events. */ 510 channel_after_select(&readset, &writeset); 511 512 /* Process input from the client and from program stdout/stderr. */ 513 process_input(&readset); 514 515 /* Process output to the client and to program stdin. */ 516 process_output(&writeset); 517 } 518 519 /* Cleanup and termination code. */ 520 521 /* Wait until all output has been sent to the client. */ 522 drain_output(); 523 524 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", 525 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); 526 527 /* Free and clear the buffers. */ 528 buffer_free(&stdin_buffer); 529 buffer_free(&stdout_buffer); 530 buffer_free(&stderr_buffer); 531 532 /* Close the file descriptors. */ 533 if (fdout != -1) 534 close(fdout); 535 fdout = -1; 536 fdout_eof = 1; 537 if (fderr != -1) 538 close(fderr); 539 fderr = -1; 540 fderr_eof = 1; 541 if (fdin != -1) 542 close(fdin); 543 fdin = -1; 544 545 /* Stop listening for channels; this removes unix domain sockets. */ 546 channel_stop_listening(); 547 548 /* Wait for the child to exit. Get its exit status. */ 549 wait_pid = wait(&wait_status); 550 if (wait_pid < 0) { 551 /* 552 * It is possible that the wait was handled by SIGCHLD 553 * handler. This may result in either: this call 554 * returning with EINTR, or: this call returning ECHILD. 555 */ 556 if (child_terminated) 557 wait_status = child_wait_status; 558 else 559 packet_disconnect("wait: %.100s", strerror(errno)); 560 } else { 561 /* Check if it matches the process we forked. */ 562 if (wait_pid != pid) 563 error("Strange, wait returned pid %d, expected %d", 564 wait_pid, pid); 565 } 566 567 /* We no longer want our SIGCHLD handler to be called. */ 568 signal(SIGCHLD, SIG_DFL); 569 570 /* Check if it exited normally. */ 571 if (WIFEXITED(wait_status)) { 572 /* Yes, normal exit. Get exit status and send it to the client. */ 573 debug("Command exited with status %d.", WEXITSTATUS(wait_status)); 574 packet_start(SSH_SMSG_EXITSTATUS); 575 packet_put_int(WEXITSTATUS(wait_status)); 576 packet_send(); 577 packet_write_wait(); 578 579 /* 580 * Wait for exit confirmation. Note that there might be 581 * other packets coming before it; however, the program has 582 * already died so we just ignore them. The client is 583 * supposed to respond with the confirmation when it receives 584 * the exit status. 585 */ 586 do { 587 int plen; 588 type = packet_read(&plen); 589 } 590 while (type != SSH_CMSG_EXIT_CONFIRMATION); 591 592 debug("Received exit confirmation."); 593 return; 594 } 595 /* Check if the program terminated due to a signal. */ 596 if (WIFSIGNALED(wait_status)) 597 packet_disconnect("Command terminated on signal %d.", 598 WTERMSIG(wait_status)); 599 600 /* Some weird exit cause. Just exit. */ 601 packet_disconnect("wait returned status %04x.", wait_status); 602 /* NOTREACHED */ 603 } 604 605 void 606 server_loop2(void) 607 { 608 fd_set readset, writeset; 609 int had_channel = 0; 610 int status; 611 pid_t pid; 612 613 debug("Entering interactive session for SSH2."); 614 615 signal(SIGCHLD, sigchld_handler2); 616 child_terminated = 0; 617 connection_in = packet_get_connection_in(); 618 connection_out = packet_get_connection_out(); 619 max_fd = connection_in; 620 if (connection_out > max_fd) 621 max_fd = connection_out; 622 server_init_dispatch(); 623 624 for (;;) { 625 process_buffered_input_packets(); 626 if (!had_channel && channel_still_open()) 627 had_channel = 1; 628 if (had_channel && !channel_still_open()) { 629 debug("!channel_still_open."); 630 break; 631 } 632 if (packet_not_very_much_data_to_write()) 633 channel_output_poll(); 634 wait_until_can_do_something(&readset, &writeset, 0); 635 if (child_terminated) { 636 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) 637 session_close_by_pid(pid, status); 638 child_terminated = 0; 639 } 640 channel_after_select(&readset, &writeset); 641 process_input(&readset); 642 process_output(&writeset); 643 } 644 signal(SIGCHLD, SIG_DFL); 645 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) 646 session_close_by_pid(pid, status); 647 channel_stop_listening(); 648 } 649 650 void 651 server_input_stdin_data(int type, int plen) 652 { 653 char *data; 654 unsigned int data_len; 655 656 /* Stdin data from the client. Append it to the buffer. */ 657 /* Ignore any data if the client has closed stdin. */ 658 if (fdin == -1) 659 return; 660 data = packet_get_string(&data_len); 661 packet_integrity_check(plen, (4 + data_len), type); 662 buffer_append(&stdin_buffer, data, data_len); 663 memset(data, 0, data_len); 664 xfree(data); 665 } 666 667 void 668 server_input_eof(int type, int plen) 669 { 670 /* 671 * Eof from the client. The stdin descriptor to the 672 * program will be closed when all buffered data has 673 * drained. 674 */ 675 debug("EOF received for stdin."); 676 packet_integrity_check(plen, 0, type); 677 stdin_eof = 1; 678 } 679 680 void 681 server_input_window_size(int type, int plen) 682 { 683 int row = packet_get_int(); 684 int col = packet_get_int(); 685 int xpixel = packet_get_int(); 686 int ypixel = packet_get_int(); 687 688 debug("Window change received."); 689 packet_integrity_check(plen, 4 * 4, type); 690 if (fdin != -1) 691 pty_change_window_size(fdin, row, col, xpixel, ypixel); 692 } 693 694 int 695 input_direct_tcpip(void) 696 { 697 int sock; 698 char *target, *originator; 699 int target_port, originator_port; 700 701 target = packet_get_string(NULL); 702 target_port = packet_get_int(); 703 originator = packet_get_string(NULL); 704 originator_port = packet_get_int(); 705 packet_done(); 706 707 debug("open direct-tcpip: from %s port %d to %s port %d", 708 originator, originator_port, target, target_port); 709 /* XXX check permission */ 710 sock = channel_connect_to(target, target_port); 711 xfree(target); 712 xfree(originator); 713 if (sock < 0) 714 return -1; 715 return channel_new("direct-tcpip", SSH_CHANNEL_OPEN, 716 sock, sock, -1, 4*1024, 32*1024, 0, xstrdup("direct-tcpip")); 717 } 718 719 void 720 server_input_channel_open(int type, int plen) 721 { 722 Channel *c = NULL; 723 char *ctype; 724 int id; 725 unsigned int len; 726 int rchan; 727 int rmaxpack; 728 int rwindow; 729 730 ctype = packet_get_string(&len); 731 rchan = packet_get_int(); 732 rwindow = packet_get_int(); 733 rmaxpack = packet_get_int(); 734 735 debug("channel_input_open: ctype %s rchan %d win %d max %d", 736 ctype, rchan, rwindow, rmaxpack); 737 738 if (strcmp(ctype, "session") == 0) { 739 debug("open session"); 740 packet_done(); 741 /* 742 * A server session has no fd to read or write 743 * until a CHANNEL_REQUEST for a shell is made, 744 * so we set the type to SSH_CHANNEL_LARVAL. 745 * Additionally, a callback for handling all 746 * CHANNEL_REQUEST messages is registered. 747 */ 748 id = channel_new(ctype, SSH_CHANNEL_LARVAL, 749 -1, -1, -1, 0, 32*1024, 0, xstrdup("server-session")); 750 if (session_open(id) == 1) { 751 channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST, 752 session_input_channel_req, (void *)0); 753 channel_register_cleanup(id, session_close_by_channel); 754 c = channel_lookup(id); 755 } else { 756 debug("session open failed, free channel %d", id); 757 channel_free(id); 758 } 759 } else if (strcmp(ctype, "direct-tcpip") == 0) { 760 id = input_direct_tcpip(); 761 if (id >= 0) 762 c = channel_lookup(id); 763 } 764 if (c != NULL) { 765 debug("confirm %s", ctype); 766 c->remote_id = rchan; 767 c->remote_window = rwindow; 768 c->remote_maxpacket = rmaxpack; 769 770 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 771 packet_put_int(c->remote_id); 772 packet_put_int(c->self); 773 packet_put_int(c->local_window); 774 packet_put_int(c->local_maxpacket); 775 packet_send(); 776 } else { 777 debug("failure %s", ctype); 778 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 779 packet_put_int(rchan); 780 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 781 packet_put_cstring("bla bla"); 782 packet_put_cstring(""); 783 packet_send(); 784 } 785 xfree(ctype); 786 } 787 788 void 789 server_init_dispatch_20() 790 { 791 debug("server_init_dispatch_20"); 792 dispatch_init(&dispatch_protocol_error); 793 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 794 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 795 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 796 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 797 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); 798 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 799 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 800 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request); 801 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 802 } 803 void 804 server_init_dispatch_13() 805 { 806 debug("server_init_dispatch_13"); 807 dispatch_init(NULL); 808 dispatch_set(SSH_CMSG_EOF, &server_input_eof); 809 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); 810 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); 811 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 812 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 813 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 814 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 815 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 816 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 817 } 818 void 819 server_init_dispatch_15() 820 { 821 server_init_dispatch_13(); 822 debug("server_init_dispatch_15"); 823 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 824 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); 825 } 826 void 827 server_init_dispatch() 828 { 829 if (compat20) 830 server_init_dispatch_20(); 831 else if (compat13) 832 server_init_dispatch_13(); 833 else 834 server_init_dispatch_15(); 835 } 836