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8efc0c15 1/*
6ae2364d 2 *
5260325f 3 * clientloop.c
6ae2364d 4 *
5260325f 5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
6ae2364d 6 *
5260325f 7 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 * All rights reserved
6ae2364d 9 *
10 *
5260325f 11 * Created: Sat Sep 23 12:23:57 1995 ylo
6ae2364d 12 *
5260325f 13 * The main loop for the interactive session (client side).
6ae2364d 14 *
8ce64345 15 * SSH2 support added by Markus Friedl.
5260325f 16 */
8efc0c15 17
18#include "includes.h"
19RCSID("$Id$");
20
21#include "xmalloc.h"
22#include "ssh.h"
23#include "packet.h"
24#include "buffer.h"
25#include "authfd.h"
6a17f9c2 26#include "readconf.h"
8efc0c15 27
8ce64345 28#include "ssh2.h"
7368a6c8 29#include "compat.h"
30#include "channels.h"
31#include "dispatch.h"
32
33
8efc0c15 34/* Flag indicating that stdin should be redirected from /dev/null. */
35extern int stdin_null_flag;
36
aa3378df 37/*
38 * Name of the host we are connecting to. This is the name given on the
39 * command line, or the HostName specified for the user-supplied name in a
40 * configuration file.
41 */
8efc0c15 42extern char *host;
43
aa3378df 44/*
45 * Flag to indicate that we have received a window change signal which has
46 * not yet been processed. This will cause a message indicating the new
47 * window size to be sent to the server a little later. This is volatile
48 * because this is updated in a signal handler.
49 */
8efc0c15 50static volatile int received_window_change_signal = 0;
51
52/* Terminal modes, as saved by enter_raw_mode. */
53static struct termios saved_tio;
54
aa3378df 55/*
56 * Flag indicating whether we are in raw mode. This is used by
57 * enter_raw_mode and leave_raw_mode.
58 */
8efc0c15 59static int in_raw_mode = 0;
60
61/* Flag indicating whether the user\'s terminal is in non-blocking mode. */
62static int in_non_blocking_mode = 0;
63
64/* Common data for the client loop code. */
5260325f 65static int escape_pending; /* Last character was the escape character */
66static int last_was_cr; /* Last character was a newline. */
67static int exit_status; /* Used to store the exit status of the command. */
68static int stdin_eof; /* EOF has been encountered on standard error. */
69static Buffer stdin_buffer; /* Buffer for stdin data. */
70static Buffer stdout_buffer; /* Buffer for stdout data. */
71static Buffer stderr_buffer; /* Buffer for stderr data. */
72static unsigned int buffer_high;/* Soft max buffer size. */
73static int max_fd; /* Maximum file descriptor number in select(). */
74static int connection_in; /* Connection to server (input). */
75static int connection_out; /* Connection to server (output). */
8efc0c15 76static unsigned long stdin_bytes, stdout_bytes, stderr_bytes;
5260325f 77static int quit_pending; /* Set to non-zero to quit the client loop. */
78static int escape_char; /* Escape character. */
8efc0c15 79
8ce64345 80
81void client_init_dispatch(void);
82int session_ident = -1;
83
aa3378df 84/* Returns the user\'s terminal to normal mode if it had been put in raw mode. */
8efc0c15 85
6ae2364d 86void
5260325f 87leave_raw_mode()
8efc0c15 88{
5260325f 89 if (!in_raw_mode)
90 return;
91 in_raw_mode = 0;
92 if (tcsetattr(fileno(stdin), TCSADRAIN, &saved_tio) < 0)
93 perror("tcsetattr");
8efc0c15 94
5260325f 95 fatal_remove_cleanup((void (*) (void *)) leave_raw_mode, NULL);
8efc0c15 96}
97
98/* Puts the user\'s terminal in raw mode. */
99
6ae2364d 100void
5260325f 101enter_raw_mode()
8efc0c15 102{
5260325f 103 struct termios tio;
104
105 if (tcgetattr(fileno(stdin), &tio) < 0)
106 perror("tcgetattr");
107 saved_tio = tio;
108 tio.c_iflag |= IGNPAR;
109 tio.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
110 tio.c_lflag &= ~(ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
8efc0c15 111#ifdef IEXTEN
5260325f 112 tio.c_lflag &= ~IEXTEN;
113#endif /* IEXTEN */
114 tio.c_oflag &= ~OPOST;
115 tio.c_cc[VMIN] = 1;
116 tio.c_cc[VTIME] = 0;
117 if (tcsetattr(fileno(stdin), TCSADRAIN, &tio) < 0)
118 perror("tcsetattr");
119 in_raw_mode = 1;
120
121 fatal_add_cleanup((void (*) (void *)) leave_raw_mode, NULL);
122}
8efc0c15 123
124/* Restores stdin to blocking mode. */
125
6ae2364d 126void
5260325f 127leave_non_blocking()
8efc0c15 128{
5260325f 129 if (in_non_blocking_mode) {
130 (void) fcntl(fileno(stdin), F_SETFL, 0);
131 in_non_blocking_mode = 0;
132 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
133 }
8efc0c15 134}
135
5260325f 136/* Puts stdin terminal in non-blocking mode. */
137
6ae2364d 138void
5260325f 139enter_non_blocking()
8efc0c15 140{
5260325f 141 in_non_blocking_mode = 1;
142 (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
143 fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
8efc0c15 144}
145
aa3378df 146/*
147 * Signal handler for the window change signal (SIGWINCH). This just sets a
148 * flag indicating that the window has changed.
149 */
8efc0c15 150
6ae2364d 151void
5260325f 152window_change_handler(int sig)
8efc0c15 153{
5260325f 154 received_window_change_signal = 1;
155 signal(SIGWINCH, window_change_handler);
8efc0c15 156}
157
aa3378df 158/*
159 * Signal handler for signals that cause the program to terminate. These
160 * signals must be trapped to restore terminal modes.
161 */
8efc0c15 162
6ae2364d 163void
5260325f 164signal_handler(int sig)
8efc0c15 165{
5260325f 166 if (in_raw_mode)
167 leave_raw_mode();
168 if (in_non_blocking_mode)
169 leave_non_blocking();
170 channel_stop_listening();
171 packet_close();
172 fatal("Killed by signal %d.", sig);
8efc0c15 173}
174
aa3378df 175/*
176 * Returns current time in seconds from Jan 1, 1970 with the maximum
177 * available resolution.
178 */
8efc0c15 179
6ae2364d 180double
5260325f 181get_current_time()
8efc0c15 182{
5260325f 183 struct timeval tv;
184 gettimeofday(&tv, NULL);
185 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
8efc0c15 186}
187
aa3378df 188/*
189 * This is called when the interactive is entered. This checks if there is
190 * an EOF coming on stdin. We must check this explicitly, as select() does
191 * not appear to wake up when redirecting from /dev/null.
192 */
8efc0c15 193
6ae2364d 194void
5260325f 195client_check_initial_eof_on_stdin()
8efc0c15 196{
5260325f 197 int len;
198 char buf[1];
199
aa3378df 200 /*
201 * If standard input is to be "redirected from /dev/null", we simply
202 * mark that we have seen an EOF and send an EOF message to the
203 * server. Otherwise, we try to read a single character; it appears
204 * that for some files, such /dev/null, select() never wakes up for
205 * read for this descriptor, which means that we never get EOF. This
206 * way we will get the EOF if stdin comes from /dev/null or similar.
207 */
5260325f 208 if (stdin_null_flag) {
209 /* Fake EOF on stdin. */
210 debug("Sending eof.");
211 stdin_eof = 1;
212 packet_start(SSH_CMSG_EOF);
213 packet_send();
214 } else {
5260325f 215 enter_non_blocking();
216
217 /* Check for immediate EOF on stdin. */
218 len = read(fileno(stdin), buf, 1);
219 if (len == 0) {
aa3378df 220 /* EOF. Record that we have seen it and send EOF to server. */
5260325f 221 debug("Sending eof.");
222 stdin_eof = 1;
223 packet_start(SSH_CMSG_EOF);
224 packet_send();
225 } else if (len > 0) {
aa3378df 226 /*
227 * Got data. We must store the data in the buffer,
228 * and also process it as an escape character if
229 * appropriate.
230 */
5260325f 231 if ((unsigned char) buf[0] == escape_char)
232 escape_pending = 1;
233 else {
234 buffer_append(&stdin_buffer, buf, 1);
235 stdin_bytes += 1;
236 }
237 }
5260325f 238 leave_non_blocking();
8efc0c15 239 }
8efc0c15 240}
241
8efc0c15 242
aa3378df 243/*
244 * Make packets from buffered stdin data, and buffer them for sending to the
245 * connection.
246 */
8efc0c15 247
6ae2364d 248void
5260325f 249client_make_packets_from_stdin_data()
8efc0c15 250{
5260325f 251 unsigned int len;
252
253 /* Send buffered stdin data to the server. */
254 while (buffer_len(&stdin_buffer) > 0 &&
255 packet_not_very_much_data_to_write()) {
256 len = buffer_len(&stdin_buffer);
257 /* Keep the packets at reasonable size. */
258 if (len > packet_get_maxsize())
259 len = packet_get_maxsize();
260 packet_start(SSH_CMSG_STDIN_DATA);
261 packet_put_string(buffer_ptr(&stdin_buffer), len);
262 packet_send();
263 buffer_consume(&stdin_buffer, len);
264 /* If we have a pending EOF, send it now. */
265 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
266 packet_start(SSH_CMSG_EOF);
267 packet_send();
268 }
8efc0c15 269 }
8efc0c15 270}
271
aa3378df 272/*
273 * Checks if the client window has changed, and sends a packet about it to
274 * the server if so. The actual change is detected elsewhere (by a software
275 * interrupt on Unix); this just checks the flag and sends a message if
276 * appropriate.
277 */
8efc0c15 278
6ae2364d 279void
5260325f 280client_check_window_change()
8efc0c15 281{
8ce64345 282 struct winsize ws;
283
284 if (! received_window_change_signal)
285 return;
286 /** XXX race */
287 received_window_change_signal = 0;
288
289 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
290 return;
291
292 debug("client_check_window_change: changed");
293
294 if (compat20) {
295 channel_request_start(session_ident, "window-change", 0);
296 packet_put_int(ws.ws_col);
297 packet_put_int(ws.ws_row);
298 packet_put_int(ws.ws_xpixel);
299 packet_put_int(ws.ws_ypixel);
300 packet_send();
301 } else {
302 packet_start(SSH_CMSG_WINDOW_SIZE);
303 packet_put_int(ws.ws_row);
304 packet_put_int(ws.ws_col);
305 packet_put_int(ws.ws_xpixel);
306 packet_put_int(ws.ws_ypixel);
307 packet_send();
8efc0c15 308 }
8efc0c15 309}
310
aa3378df 311/*
312 * Waits until the client can do something (some data becomes available on
313 * one of the file descriptors).
314 */
8efc0c15 315
6ae2364d 316void
5260325f 317client_wait_until_can_do_something(fd_set * readset, fd_set * writeset)
8efc0c15 318{
8ce64345 319 /*debug("client_wait_until_can_do_something"); */
320
5260325f 321 /* Initialize select masks. */
322 FD_ZERO(readset);
8ce64345 323 FD_ZERO(writeset);
5260325f 324
8ce64345 325 if (!compat20) {
326 /* Read from the connection, unless our buffers are full. */
327 if (buffer_len(&stdout_buffer) < buffer_high &&
328 buffer_len(&stderr_buffer) < buffer_high &&
329 channel_not_very_much_buffered_data())
330 FD_SET(connection_in, readset);
331 /*
332 * Read from stdin, unless we have seen EOF or have very much
333 * buffered data to send to the server.
334 */
335 if (!stdin_eof && packet_not_very_much_data_to_write())
336 FD_SET(fileno(stdin), readset);
337
338 /* Select stdout/stderr if have data in buffer. */
339 if (buffer_len(&stdout_buffer) > 0)
340 FD_SET(fileno(stdout), writeset);
341 if (buffer_len(&stderr_buffer) > 0)
342 FD_SET(fileno(stderr), writeset);
343 } else {
5260325f 344 FD_SET(connection_in, readset);
8ce64345 345 }
5260325f 346
347 /* Add any selections by the channel mechanism. */
348 channel_prepare_select(readset, writeset);
349
350 /* Select server connection if have data to write to the server. */
351 if (packet_have_data_to_write())
352 FD_SET(connection_out, writeset);
353
8ce64345 354/* move UP XXX */
5260325f 355 /* Update maximum file descriptor number, if appropriate. */
356 if (channel_max_fd() > max_fd)
357 max_fd = channel_max_fd();
358
aa3378df 359 /*
360 * Wait for something to happen. This will suspend the process until
361 * some selected descriptor can be read, written, or has some other
362 * event pending. Note: if you want to implement SSH_MSG_IGNORE
363 * messages to fool traffic analysis, this might be the place to do
364 * it: just have a random timeout for the select, and send a random
365 * SSH_MSG_IGNORE packet when the timeout expires.
366 */
5260325f 367
368 if (select(max_fd + 1, readset, writeset, NULL, NULL) < 0) {
369 char buf[100];
370 /* Some systems fail to clear these automatically. */
371 FD_ZERO(readset);
372 FD_ZERO(writeset);
373 if (errno == EINTR)
374 return;
375 /* Note: we might still have data in the buffers. */
376 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
377 buffer_append(&stderr_buffer, buf, strlen(buf));
378 stderr_bytes += strlen(buf);
379 quit_pending = 1;
380 }
8efc0c15 381}
382
6ae2364d 383void
5260325f 384client_suspend_self()
8efc0c15 385{
5260325f 386 struct winsize oldws, newws;
387
388 /* Flush stdout and stderr buffers. */
389 if (buffer_len(&stdout_buffer) > 0)
a408af76 390 atomicio(write, fileno(stdout), buffer_ptr(&stdout_buffer),
391 buffer_len(&stdout_buffer));
5260325f 392 if (buffer_len(&stderr_buffer) > 0)
a408af76 393 atomicio(write, fileno(stderr), buffer_ptr(&stderr_buffer),
394 buffer_len(&stderr_buffer));
5260325f 395
5260325f 396 leave_raw_mode();
397
aa3378df 398 /*
399 * Free (and clear) the buffer to reduce the amount of data that gets
400 * written to swap.
401 */
5260325f 402 buffer_free(&stdin_buffer);
403 buffer_free(&stdout_buffer);
404 buffer_free(&stderr_buffer);
405
406 /* Save old window size. */
407 ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
408
409 /* Send the suspend signal to the program itself. */
410 kill(getpid(), SIGTSTP);
411
412 /* Check if the window size has changed. */
413 if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
414 (oldws.ws_row != newws.ws_row ||
415 oldws.ws_col != newws.ws_col ||
416 oldws.ws_xpixel != newws.ws_xpixel ||
417 oldws.ws_ypixel != newws.ws_ypixel))
418 received_window_change_signal = 1;
419
420 /* OK, we have been continued by the user. Reinitialize buffers. */
421 buffer_init(&stdin_buffer);
422 buffer_init(&stdout_buffer);
423 buffer_init(&stderr_buffer);
424
5260325f 425 enter_raw_mode();
8efc0c15 426}
427
6ae2364d 428void
8ce64345 429client_process_net_input(fd_set * readset)
8efc0c15 430{
8ce64345 431 int len;
432 char buf[8192];
5260325f 433
aa3378df 434 /*
435 * Read input from the server, and add any such data to the buffer of
436 * the packet subsystem.
437 */
5260325f 438 if (FD_ISSET(connection_in, readset)) {
439 /* Read as much as possible. */
440 len = read(connection_in, buf, sizeof(buf));
8ce64345 441/*debug("read connection_in len %d", len); XXX */
5260325f 442 if (len == 0) {
443 /* Received EOF. The remote host has closed the connection. */
444 snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
445 host);
8efc0c15 446 buffer_append(&stderr_buffer, buf, strlen(buf));
447 stderr_bytes += strlen(buf);
448 quit_pending = 1;
449 return;
5260325f 450 }
aa3378df 451 /*
452 * There is a kernel bug on Solaris that causes select to
453 * sometimes wake up even though there is no data available.
454 */
5260325f 455 if (len < 0 && errno == EAGAIN)
456 len = 0;
457
458 if (len < 0) {
459 /* An error has encountered. Perhaps there is a network problem. */
460 snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
461 host, strerror(errno));
462 buffer_append(&stderr_buffer, buf, strlen(buf));
463 stderr_bytes += strlen(buf);
464 quit_pending = 1;
465 return;
466 }
467 packet_process_incoming(buf, len);
468 }
8ce64345 469}
470
6ae2364d 471void
8ce64345 472client_process_input(fd_set * readset)
473{
9da5c3c9 474 int len;
475 pid_t pid;
8ce64345 476 char buf[8192], *s;
477
5260325f 478 /* Read input from stdin. */
479 if (FD_ISSET(fileno(stdin), readset)) {
480 /* Read as much as possible. */
481 len = read(fileno(stdin), buf, sizeof(buf));
482 if (len <= 0) {
aa3378df 483 /*
484 * Received EOF or error. They are treated
485 * similarly, except that an error message is printed
486 * if it was an error condition.
487 */
5260325f 488 if (len < 0) {
489 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
490 buffer_append(&stderr_buffer, buf, strlen(buf));
491 stderr_bytes += strlen(buf);
492 }
493 /* Mark that we have seen EOF. */
494 stdin_eof = 1;
aa3378df 495 /*
496 * Send an EOF message to the server unless there is
497 * data in the buffer. If there is data in the
498 * buffer, no message will be sent now. Code
499 * elsewhere will send the EOF when the buffer
500 * becomes empty if stdin_eof is set.
501 */
5260325f 502 if (buffer_len(&stdin_buffer) == 0) {
8efc0c15 503 packet_start(SSH_CMSG_EOF);
504 packet_send();
5260325f 505 }
506 } else if (escape_char == -1) {
aa3378df 507 /*
508 * Normal successful read, and no escape character.
509 * Just append the data to buffer.
510 */
5260325f 511 buffer_append(&stdin_buffer, buf, len);
512 stdin_bytes += len;
513 } else {
aa3378df 514 /*
515 * Normal, successful read. But we have an escape character
516 * and have to process the characters one by one.
517 */
5260325f 518 unsigned int i;
519 for (i = 0; i < len; i++) {
520 unsigned char ch;
521 /* Get one character at a time. */
522 ch = buf[i];
523
5260325f 524 if (escape_pending) {
525 /* We have previously seen an escape character. */
526 /* Clear the flag now. */
527 escape_pending = 0;
528 /* Process the escaped character. */
529 switch (ch) {
530 case '.':
531 /* Terminate the connection. */
532 snprintf(buf, sizeof buf, "%c.\r\n", escape_char);
533 buffer_append(&stderr_buffer, buf, strlen(buf));
534 stderr_bytes += strlen(buf);
535 quit_pending = 1;
536 return;
537
538 case 'Z' - 64:
539 /* Suspend the program. */
540 /* Print a message to that effect to the user. */
541 snprintf(buf, sizeof buf, "%c^Z\r\n", escape_char);
542 buffer_append(&stderr_buffer, buf, strlen(buf));
543 stderr_bytes += strlen(buf);
544
545 /* Restore terminal modes and suspend. */
546 client_suspend_self();
547
548 /* We have been continued. */
549 continue;
550
551 case '&':
aa3378df 552 /*
553 * Detach the program (continue to serve connections,
554 * but put in background and no more new connections).
555 */
5260325f 556 if (!stdin_eof) {
aa3378df 557 /*
558 * Sending SSH_CMSG_EOF alone does not always appear
559 * to be enough. So we try to send an EOF character
560 * first.
561 */
5260325f 562 packet_start(SSH_CMSG_STDIN_DATA);
563 packet_put_string("\004", 1);
564 packet_send();
565 /* Close stdin. */
566 stdin_eof = 1;
567 if (buffer_len(&stdin_buffer) == 0) {
568 packet_start(SSH_CMSG_EOF);
569 packet_send();
570 }
571 }
572 /* Restore tty modes. */
573 leave_raw_mode();
574
575 /* Stop listening for new connections. */
576 channel_stop_listening();
577
578 printf("%c& [backgrounded]\n", escape_char);
579
580 /* Fork into background. */
581 pid = fork();
582 if (pid < 0) {
583 error("fork: %.100s", strerror(errno));
584 continue;
585 }
586 if (pid != 0) { /* This is the parent. */
587 /* The parent just exits. */
588 exit(0);
589 }
590 /* The child continues serving connections. */
591 continue;
592
593 case '?':
594 snprintf(buf, sizeof buf,
595"%c?\r\n\
8efc0c15 596Supported escape sequences:\r\n\
597~. - terminate connection\r\n\
598~^Z - suspend ssh\r\n\
599~# - list forwarded connections\r\n\
600~& - background ssh (when waiting for connections to terminate)\r\n\
601~? - this message\r\n\
602~~ - send the escape character by typing it twice\r\n\
603(Note that escapes are only recognized immediately after newline.)\r\n",
5260325f 604 escape_char);
605 buffer_append(&stderr_buffer, buf, strlen(buf));
606 continue;
607
608 case '#':
609 snprintf(buf, sizeof buf, "%c#\r\n", escape_char);
610 buffer_append(&stderr_buffer, buf, strlen(buf));
611 s = channel_open_message();
612 buffer_append(&stderr_buffer, s, strlen(s));
613 xfree(s);
614 continue;
615
616 default:
617 if (ch != escape_char) {
aa3378df 618 /*
619 * Escape character followed by non-special character.
620 * Append both to the input buffer.
621 */
5260325f 622 buf[0] = escape_char;
623 buf[1] = ch;
624 buffer_append(&stdin_buffer, buf, 2);
625 stdin_bytes += 2;
626 continue;
627 }
aa3378df 628 /*
629 * Note that escape character typed twice
630 * falls through here; the latter gets processed
631 * as a normal character below.
632 */
5260325f 633 break;
634 }
635 } else {
aa3378df 636 /*
637 * The previous character was not an escape char. Check if this
638 * is an escape.
639 */
5260325f 640 if (last_was_cr && ch == escape_char) {
641 /* It is. Set the flag and continue to next character. */
642 escape_pending = 1;
643 continue;
644 }
645 }
646
aa3378df 647 /*
648 * Normal character. Record whether it was a newline,
649 * and append it to the buffer.
650 */
5260325f 651 last_was_cr = (ch == '\r' || ch == '\n');
652 buf[0] = ch;
653 buffer_append(&stdin_buffer, buf, 1);
654 stdin_bytes += 1;
655 continue;
656 }
657 }
658 }
8efc0c15 659}
660
6ae2364d 661void
5260325f 662client_process_output(fd_set * writeset)
8efc0c15 663{
5260325f 664 int len;
665 char buf[100];
666
667 /* Write buffered output to stdout. */
668 if (FD_ISSET(fileno(stdout), writeset)) {
669 /* Write as much data as possible. */
670 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
a408af76 671 buffer_len(&stdout_buffer));
5260325f 672 if (len <= 0) {
673 if (errno == EAGAIN)
674 len = 0;
675 else {
aa3378df 676 /*
677 * An error or EOF was encountered. Put an
678 * error message to stderr buffer.
679 */
5260325f 680 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
681 buffer_append(&stderr_buffer, buf, strlen(buf));
682 stderr_bytes += strlen(buf);
683 quit_pending = 1;
684 return;
685 }
686 }
687 /* Consume printed data from the buffer. */
688 buffer_consume(&stdout_buffer, len);
689 }
690 /* Write buffered output to stderr. */
691 if (FD_ISSET(fileno(stderr), writeset)) {
692 /* Write as much data as possible. */
693 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
a408af76 694 buffer_len(&stderr_buffer));
5260325f 695 if (len <= 0) {
696 if (errno == EAGAIN)
697 len = 0;
698 else {
aa3378df 699 /* EOF or error, but can't even print error message. */
5260325f 700 quit_pending = 1;
701 return;
702 }
703 }
704 /* Consume printed characters from the buffer. */
705 buffer_consume(&stderr_buffer, len);
8efc0c15 706 }
8efc0c15 707}
708
7368a6c8 709/*
710 * Get packets from the connection input buffer, and process them as long as
711 * there are packets available.
712 *
713 * Any unknown packets received during the actual
714 * session cause the session to terminate. This is
715 * intended to make debugging easier since no
716 * confirmations are sent. Any compatible protocol
717 * extensions must be negotiated during the
718 * preparatory phase.
719 */
720
6ae2364d 721void
7368a6c8 722client_process_buffered_input_packets()
723{
724 dispatch_run(DISPATCH_NONBLOCK, &quit_pending);
725}
726
aa3378df 727/*
728 * Implements the interactive session with the server. This is called after
729 * the user has been authenticated, and a command has been started on the
730 * remote host. If escape_char != -1, it is the character used as an escape
731 * character for terminating or suspending the session.
732 */
8efc0c15 733
6ae2364d 734int
5260325f 735client_loop(int have_pty, int escape_char_arg)
8efc0c15 736{
5260325f 737 extern Options options;
738 double start_time, total_time;
739 int len;
740 char buf[100];
741
742 debug("Entering interactive session.");
743
744 start_time = get_current_time();
745
746 /* Initialize variables. */
747 escape_pending = 0;
748 last_was_cr = 1;
749 exit_status = -1;
750 stdin_eof = 0;
751 buffer_high = 64 * 1024;
752 connection_in = packet_get_connection_in();
753 connection_out = packet_get_connection_out();
754 max_fd = connection_in;
755 if (connection_out > max_fd)
756 max_fd = connection_out;
757 stdin_bytes = 0;
758 stdout_bytes = 0;
759 stderr_bytes = 0;
760 quit_pending = 0;
761 escape_char = escape_char_arg;
762
763 /* Initialize buffers. */
764 buffer_init(&stdin_buffer);
765 buffer_init(&stdout_buffer);
766 buffer_init(&stderr_buffer);
767
7368a6c8 768 client_init_dispatch();
769
5260325f 770 /* Set signal handlers to restore non-blocking mode. */
771 signal(SIGINT, signal_handler);
772 signal(SIGQUIT, signal_handler);
773 signal(SIGTERM, signal_handler);
774 signal(SIGPIPE, SIG_IGN);
775 if (have_pty)
776 signal(SIGWINCH, window_change_handler);
777
5260325f 778 if (have_pty)
779 enter_raw_mode();
780
781 /* Check if we should immediately send of on stdin. */
8ce64345 782 if (!compat20)
783 client_check_initial_eof_on_stdin();
5260325f 784
785 /* Main loop of the client for the interactive session mode. */
786 while (!quit_pending) {
787 fd_set readset, writeset;
788
aa3378df 789 /* Process buffered packets sent by the server. */
5260325f 790 client_process_buffered_input_packets();
791
8ce64345 792 if (compat20 && !channel_still_open()) {
793 debug("!channel_still_open.");
794 break;
795 }
796
aa3378df 797 /*
798 * Make packets of buffered stdin data, and buffer them for
799 * sending to the server.
800 */
8ce64345 801 if (!compat20)
802 client_make_packets_from_stdin_data();
5260325f 803
aa3378df 804 /*
805 * Make packets from buffered channel data, and buffer them
806 * for sending to the server.
807 */
5260325f 808 if (packet_not_very_much_data_to_write())
809 channel_output_poll();
810
aa3378df 811 /*
812 * Check if the window size has changed, and buffer a message
813 * about it to the server if so.
814 */
5260325f 815 client_check_window_change();
816
817 if (quit_pending)
818 break;
819
aa3378df 820 /*
821 * Wait until we have something to do (something becomes
822 * available on one of the descriptors).
823 */
5260325f 824 client_wait_until_can_do_something(&readset, &writeset);
825
826 if (quit_pending)
827 break;
828
829 /* Do channel operations. */
830 channel_after_select(&readset, &writeset);
831
8ce64345 832 /* Buffer input from the connection. */
833 client_process_net_input(&readset);
5260325f 834
8ce64345 835 if (quit_pending)
836 break;
837
838 if (!compat20) {
839 /* Buffer data from stdin */
840 client_process_input(&readset);
841 /*
842 * Process output to stdout and stderr. Output to
843 * the connection is processed elsewhere (above).
844 */
845 client_process_output(&writeset);
846 }
5260325f 847
aa3378df 848 /* Send as much buffered packet data as possible to the sender. */
5260325f 849 if (FD_ISSET(connection_out, &writeset))
850 packet_write_poll();
851 }
852
853 /* Terminate the session. */
854
855 /* Stop watching for window change. */
856 if (have_pty)
857 signal(SIGWINCH, SIG_DFL);
858
859 /* Stop listening for connections. */
860 channel_stop_listening();
861
aa3378df 862 /*
863 * In interactive mode (with pseudo tty) display a message indicating
864 * that the connection has been closed.
865 */
5260325f 866 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
867 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
868 buffer_append(&stderr_buffer, buf, strlen(buf));
869 stderr_bytes += strlen(buf);
8efc0c15 870 }
5260325f 871 /* Output any buffered data for stdout. */
872 while (buffer_len(&stdout_buffer) > 0) {
873 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
a408af76 874 buffer_len(&stdout_buffer));
5260325f 875 if (len <= 0) {
876 error("Write failed flushing stdout buffer.");
877 break;
878 }
879 buffer_consume(&stdout_buffer, len);
8efc0c15 880 }
5260325f 881
882 /* Output any buffered data for stderr. */
883 while (buffer_len(&stderr_buffer) > 0) {
884 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
a408af76 885 buffer_len(&stderr_buffer));
5260325f 886 if (len <= 0) {
887 error("Write failed flushing stderr buffer.");
888 break;
889 }
890 buffer_consume(&stderr_buffer, len);
891 }
892
5260325f 893 if (have_pty)
894 leave_raw_mode();
895
896 /* Clear and free any buffers. */
897 memset(buf, 0, sizeof(buf));
898 buffer_free(&stdin_buffer);
899 buffer_free(&stdout_buffer);
900 buffer_free(&stderr_buffer);
901
902 /* Report bytes transferred, and transfer rates. */
903 total_time = get_current_time() - start_time;
904 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
905 stdin_bytes, stdout_bytes, stderr_bytes, total_time);
906 if (total_time > 0)
907 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
908 stdin_bytes / total_time, stdout_bytes / total_time,
909 stderr_bytes / total_time);
910
911 /* Return the exit status of the program. */
912 debug("Exit status %d", exit_status);
913 return exit_status;
8efc0c15 914}
7368a6c8 915
916/*********/
917
918void
919client_input_stdout_data(int type, int plen)
920{
921 unsigned int data_len;
922 char *data = packet_get_string(&data_len);
923 packet_integrity_check(plen, 4 + data_len, type);
924 buffer_append(&stdout_buffer, data, data_len);
925 stdout_bytes += data_len;
926 memset(data, 0, data_len);
927 xfree(data);
928}
929void
930client_input_stderr_data(int type, int plen)
931{
932 unsigned int data_len;
933 char *data = packet_get_string(&data_len);
934 packet_integrity_check(plen, 4 + data_len, type);
935 buffer_append(&stderr_buffer, data, data_len);
936 stdout_bytes += data_len;
937 memset(data, 0, data_len);
938 xfree(data);
939}
940void
941client_input_exit_status(int type, int plen)
942{
943 packet_integrity_check(plen, 4, type);
944 exit_status = packet_get_int();
945 /* Acknowledge the exit. */
946 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
947 packet_send();
948 /*
949 * Must wait for packet to be sent since we are
950 * exiting the loop.
951 */
952 packet_write_wait();
953 /* Flag that we want to exit. */
954 quit_pending = 1;
955}
956
0b242b12 957/* XXXX move to generic input handler */
958void
959client_input_channel_open(int type, int plen)
960{
961 Channel *c = NULL;
962 char *ctype;
963 int id;
964 unsigned int len;
965 int rchan;
966 int rmaxpack;
967 int rwindow;
968
969 ctype = packet_get_string(&len);
970 rchan = packet_get_int();
971 rwindow = packet_get_int();
972 rmaxpack = packet_get_int();
973
1d1ffb87 974 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
0b242b12 975 ctype, rchan, rwindow, rmaxpack);
976
977 if (strcmp(ctype, "x11") == 0) {
978 int sock;
979 char *originator;
980 int originator_port;
981 originator = packet_get_string(NULL);
982 originator_port = packet_get_int();
983 packet_done();
984 /* XXX check permission */
985 xfree(originator);
986 /* XXX move to channels.c */
987 sock = x11_connect_display();
988 if (sock >= 0) {
989 id = channel_new("x11", SSH_CHANNEL_X11_OPEN,
990 sock, sock, -1, 4*1024, 32*1024, 0,
991 xstrdup("x11"));
992 c = channel_lookup(id);
993 }
994 }
995/* XXX duplicate : */
996 if (c != NULL) {
997 debug("confirm %s", ctype);
998 c->remote_id = rchan;
999 c->remote_window = rwindow;
1000 c->remote_maxpacket = rmaxpack;
1001
1002 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1003 packet_put_int(c->remote_id);
1004 packet_put_int(c->self);
1005 packet_put_int(c->local_window);
1006 packet_put_int(c->local_maxpacket);
1007 packet_send();
1008 } else {
1009 debug("failure %s", ctype);
1010 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1011 packet_put_int(rchan);
1012 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1013 packet_put_cstring("bla bla");
1014 packet_put_cstring("");
1015 packet_send();
1016 }
1017 xfree(ctype);
1018}
1019
6ae2364d 1020void
8ce64345 1021client_init_dispatch_20()
1022{
1023 dispatch_init(&dispatch_protocol_error);
1024 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1025 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1026 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1027 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
0b242b12 1028 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
8ce64345 1029 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1030 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1031 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
1032 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1033}
6ae2364d 1034void
7368a6c8 1035client_init_dispatch_13()
1036{
1037 dispatch_init(NULL);
1038 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1039 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1040 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
7368a6c8 1041 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1042 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1043 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1044 dispatch_set(SSH_SMSG_AGENT_OPEN, &auth_input_open_request);
1045 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1046 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1047 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1048 dispatch_set(SSH_SMSG_X11_OPEN, &x11_input_open);
1049}
6ae2364d 1050void
7368a6c8 1051client_init_dispatch_15()
1052{
1053 client_init_dispatch_13();
1054 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1055 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1056}
6ae2364d 1057void
7368a6c8 1058client_init_dispatch()
1059{
8ce64345 1060 if (compat20)
1061 client_init_dispatch_20();
1062 else if (compat13)
7368a6c8 1063 client_init_dispatch_13();
1064 else
1065 client_init_dispatch_15();
1066}
8ce64345 1067
1068void
1069client_input_channel_req(int id, void *arg)
1070{
1071 Channel *c = NULL;
1072 unsigned int len;
1073 int success = 0;
1074 int reply;
1075 char *rtype;
1076
1077 rtype = packet_get_string(&len);
1078 reply = packet_get_char();
1079
1d1ffb87 1080 debug("client_input_channel_req: rtype %s reply %d", rtype, reply);
8ce64345 1081
1082 c = channel_lookup(id);
1083 if (c == NULL)
1084 fatal("session_input_channel_req: channel %d: bad channel", id);
1085
1086 if (session_ident == -1) {
1087 error("client_input_channel_req: no channel %d", id);
1088 } else if (id != session_ident) {
1089 error("client_input_channel_req: bad channel %d != %d",
1090 id, session_ident);
1091 } else if (strcmp(rtype, "exit-status") == 0) {
1092 success = 1;
1093 exit_status = packet_get_int();
6ae2364d 1094 packet_done();
8ce64345 1095 }
1096 if (reply) {
1097 packet_start(success ?
1098 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1099 packet_put_int(c->remote_id);
1100 packet_send();
1101 }
1102 xfree(rtype);
1103}
1104
1105void
1106client_set_session_ident(int id)
1107{
1108 debug("client_set_session_ident: id %d", id);
1109 session_ident = id;
1110 channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
1111 client_input_channel_req, (void *)0);
1112}
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