summaryrefslogtreecommitdiff
path: root/other/ssharp/clientloop.c
diff options
context:
space:
mode:
Diffstat (limited to 'other/ssharp/clientloop.c')
-rw-r--r--other/ssharp/clientloop.c1252
1 files changed, 1252 insertions, 0 deletions
diff --git a/other/ssharp/clientloop.c b/other/ssharp/clientloop.c
new file mode 100644
index 0000000..369ffe4
--- /dev/null
+++ b/other/ssharp/clientloop.c
@@ -0,0 +1,1252 @@
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 * The main loop for the interactive session (client side).
6 *
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
12 *
13 *
14 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 *
37 * SSH2 support added by Markus Friedl.
38 * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
50 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
53 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
54 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
55 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
56 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
57 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
58 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59 */
60
61#include "includes.h"
62RCSID("$OpenBSD: clientloop.c,v 1.65 2001/04/20 07:17:51 djm Exp $");
63
64#include "ssh.h"
65#include "ssh1.h"
66#include "ssh2.h"
67#include "xmalloc.h"
68#include "packet.h"
69#include "buffer.h"
70#include "compat.h"
71#include "channels.h"
72#include "dispatch.h"
73#include "buffer.h"
74#include "bufaux.h"
75#include "key.h"
76#include "kex.h"
77#include "log.h"
78#include "readconf.h"
79#include "clientloop.h"
80#include "authfd.h"
81#include "atomicio.h"
82#include "sshtty.h"
83#include "misc.h"
84
85/* import options */
86extern Options options;
87
88/* Flag indicating that stdin should be redirected from /dev/null. */
89extern int stdin_null_flag;
90
91/*
92 * Name of the host we are connecting to. This is the name given on the
93 * command line, or the HostName specified for the user-supplied name in a
94 * configuration file.
95 */
96extern char *host;
97
98/*
99 * Flag to indicate that we have received a window change signal which has
100 * not yet been processed. This will cause a message indicating the new
101 * window size to be sent to the server a little later. This is volatile
102 * because this is updated in a signal handler.
103 */
104static volatile int received_window_change_signal = 0;
105
106/* Flag indicating whether the user\'s terminal is in non-blocking mode. */
107static int in_non_blocking_mode = 0;
108
109/* Common data for the client loop code. */
110static int quit_pending; /* Set to non-zero to quit the client loop. */
111static int escape_char; /* Escape character. */
112static int escape_pending; /* Last character was the escape character */
113static int last_was_cr; /* Last character was a newline. */
114static int exit_status; /* Used to store the exit status of the command. */
115static int stdin_eof; /* EOF has been encountered on standard error. */
116static Buffer stdin_buffer; /* Buffer for stdin data. */
117static Buffer stdout_buffer; /* Buffer for stdout data. */
118static Buffer stderr_buffer; /* Buffer for stderr data. */
119static u_long stdin_bytes, stdout_bytes, stderr_bytes;
120static u_int buffer_high;/* Soft max buffer size. */
121static int connection_in; /* Connection to server (input). */
122static int connection_out; /* Connection to server (output). */
123static int need_rekeying; /* Set to non-zero if rekeying is requested. */
124static int session_closed = 0; /* In SSH2: login session closed. */
125
126void client_init_dispatch(void);
127int session_ident = -1;
128
129/*XXX*/
130extern Kex *xxx_kex;
131
132/* Restores stdin to blocking mode. */
133
134void
135leave_non_blocking(void)
136{
137 if (in_non_blocking_mode) {
138 (void) fcntl(fileno(stdin), F_SETFL, 0);
139 in_non_blocking_mode = 0;
140 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
141 }
142}
143
144/* Puts stdin terminal in non-blocking mode. */
145
146void
147enter_non_blocking(void)
148{
149 in_non_blocking_mode = 1;
150 (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
151 fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
152}
153
154/*
155 * Signal handler for the window change signal (SIGWINCH). This just sets a
156 * flag indicating that the window has changed.
157 */
158
159void
160window_change_handler(int sig)
161{
162 received_window_change_signal = 1;
163 signal(SIGWINCH, window_change_handler);
164}
165
166/*
167 * Signal handler for signals that cause the program to terminate. These
168 * signals must be trapped to restore terminal modes.
169 */
170
171void
172signal_handler(int sig)
173{
174 if (in_raw_mode())
175 leave_raw_mode();
176 if (in_non_blocking_mode)
177 leave_non_blocking();
178 channel_stop_listening();
179 packet_close();
180 fatal("Killed by signal %d.", sig);
181}
182
183/*
184 * Returns current time in seconds from Jan 1, 1970 with the maximum
185 * available resolution.
186 */
187
188double
189get_current_time(void)
190{
191 struct timeval tv;
192 gettimeofday(&tv, NULL);
193 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
194}
195
196/*
197 * This is called when the interactive is entered. This checks if there is
198 * an EOF coming on stdin. We must check this explicitly, as select() does
199 * not appear to wake up when redirecting from /dev/null.
200 */
201
202void
203client_check_initial_eof_on_stdin(void)
204{
205 int len;
206 char buf[1];
207
208 /*
209 * If standard input is to be "redirected from /dev/null", we simply
210 * mark that we have seen an EOF and send an EOF message to the
211 * server. Otherwise, we try to read a single character; it appears
212 * that for some files, such /dev/null, select() never wakes up for
213 * read for this descriptor, which means that we never get EOF. This
214 * way we will get the EOF if stdin comes from /dev/null or similar.
215 */
216 if (stdin_null_flag) {
217 /* Fake EOF on stdin. */
218 debug("Sending eof.");
219 stdin_eof = 1;
220 packet_start(SSH_CMSG_EOF);
221 packet_send();
222 } else {
223 enter_non_blocking();
224
225 /* Check for immediate EOF on stdin. */
226 len = read(fileno(stdin), buf, 1);
227 if (len == 0) {
228 /* EOF. Record that we have seen it and send EOF to server. */
229 debug("Sending eof.");
230 stdin_eof = 1;
231 packet_start(SSH_CMSG_EOF);
232 packet_send();
233 } else if (len > 0) {
234 /*
235 * Got data. We must store the data in the buffer,
236 * and also process it as an escape character if
237 * appropriate.
238 */
239 if ((u_char) buf[0] == escape_char)
240 escape_pending = 1;
241 else
242 buffer_append(&stdin_buffer, buf, 1);
243 }
244 leave_non_blocking();
245 }
246}
247
248
249/*
250 * Make packets from buffered stdin data, and buffer them for sending to the
251 * connection.
252 */
253
254void
255client_make_packets_from_stdin_data(void)
256{
257 u_int len;
258
259 /* Send buffered stdin data to the server. */
260 while (buffer_len(&stdin_buffer) > 0 &&
261 packet_not_very_much_data_to_write()) {
262 len = buffer_len(&stdin_buffer);
263 /* Keep the packets at reasonable size. */
264 if (len > packet_get_maxsize())
265 len = packet_get_maxsize();
266 packet_start(SSH_CMSG_STDIN_DATA);
267 packet_put_string(buffer_ptr(&stdin_buffer), len);
268 packet_send();
269 buffer_consume(&stdin_buffer, len);
270 stdin_bytes += len;
271 /* If we have a pending EOF, send it now. */
272 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
273 packet_start(SSH_CMSG_EOF);
274 packet_send();
275 }
276 }
277}
278
279/*
280 * Checks if the client window has changed, and sends a packet about it to
281 * the server if so. The actual change is detected elsewhere (by a software
282 * interrupt on Unix); this just checks the flag and sends a message if
283 * appropriate.
284 */
285
286void
287client_check_window_change(void)
288{
289 struct winsize ws;
290
291 if (! received_window_change_signal)
292 return;
293 /** XXX race */
294 received_window_change_signal = 0;
295
296 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
297 return;
298
299 debug2("client_check_window_change: changed");
300
301 if (compat20) {
302 channel_request_start(session_ident, "window-change", 0);
303 packet_put_int(ws.ws_col);
304 packet_put_int(ws.ws_row);
305 packet_put_int(ws.ws_xpixel);
306 packet_put_int(ws.ws_ypixel);
307 packet_send();
308 } else {
309 packet_start(SSH_CMSG_WINDOW_SIZE);
310 packet_put_int(ws.ws_row);
311 packet_put_int(ws.ws_col);
312 packet_put_int(ws.ws_xpixel);
313 packet_put_int(ws.ws_ypixel);
314 packet_send();
315 }
316}
317
318/*
319 * Waits until the client can do something (some data becomes available on
320 * one of the file descriptors).
321 */
322
323void
324client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
325 int *maxfdp, int rekeying)
326{
327 /* Add any selections by the channel mechanism. */
328 channel_prepare_select(readsetp, writesetp, maxfdp, rekeying);
329
330 if (!compat20) {
331 /* Read from the connection, unless our buffers are full. */
332 if (buffer_len(&stdout_buffer) < buffer_high &&
333 buffer_len(&stderr_buffer) < buffer_high &&
334 channel_not_very_much_buffered_data())
335 FD_SET(connection_in, *readsetp);
336 /*
337 * Read from stdin, unless we have seen EOF or have very much
338 * buffered data to send to the server.
339 */
340 if (!stdin_eof && packet_not_very_much_data_to_write())
341 FD_SET(fileno(stdin), *readsetp);
342
343 /* Select stdout/stderr if have data in buffer. */
344 if (buffer_len(&stdout_buffer) > 0)
345 FD_SET(fileno(stdout), *writesetp);
346 if (buffer_len(&stderr_buffer) > 0)
347 FD_SET(fileno(stderr), *writesetp);
348 } else {
349 FD_SET(connection_in, *readsetp);
350 }
351
352 /* Select server connection if have data to write to the server. */
353 if (packet_have_data_to_write())
354 FD_SET(connection_out, *writesetp);
355
356 /*
357 * Wait for something to happen. This will suspend the process until
358 * some selected descriptor can be read, written, or has some other
359 * event pending. Note: if you want to implement SSH_MSG_IGNORE
360 * messages to fool traffic analysis, this might be the place to do
361 * it: just have a random timeout for the select, and send a random
362 * SSH_MSG_IGNORE packet when the timeout expires.
363 */
364
365 if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
366 char buf[100];
367
368 /*
369 * We have to clear the select masks, because we return.
370 * We have to return, because the mainloop checks for the flags
371 * set by the signal handlers.
372 */
373 memset(*readsetp, 0, *maxfdp);
374 memset(*writesetp, 0, *maxfdp);
375
376 if (errno == EINTR)
377 return;
378 /* Note: we might still have data in the buffers. */
379 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
380 buffer_append(&stderr_buffer, buf, strlen(buf));
381 quit_pending = 1;
382 }
383}
384
385void
386client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
387{
388 struct winsize oldws, newws;
389
390 /* Flush stdout and stderr buffers. */
391 if (buffer_len(bout) > 0)
392 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
393 if (buffer_len(berr) > 0)
394 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
395
396 leave_raw_mode();
397
398 /*
399 * Free (and clear) the buffer to reduce the amount of data that gets
400 * written to swap.
401 */
402 buffer_free(bin);
403 buffer_free(bout);
404 buffer_free(berr);
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(bin);
422 buffer_init(bout);
423 buffer_init(berr);
424
425 enter_raw_mode();
426}
427
428void
429client_process_net_input(fd_set * readset)
430{
431 int len;
432 char buf[8192];
433
434 /*
435 * Read input from the server, and add any such data to the buffer of
436 * the packet subsystem.
437 */
438 if (FD_ISSET(connection_in, readset)) {
439 /* Read as much as possible. */
440 len = read(connection_in, buf, sizeof(buf));
441 if (len == 0) {
442 /* Received EOF. The remote host has closed the connection. */
443 snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
444 host);
445 buffer_append(&stderr_buffer, buf, strlen(buf));
446 quit_pending = 1;
447 return;
448 }
449 /*
450 * There is a kernel bug on Solaris that causes select to
451 * sometimes wake up even though there is no data available.
452 */
453 if (len < 0 && (errno == EAGAIN || errno == EINTR))
454 len = 0;
455
456 if (len < 0) {
457 /* An error has encountered. Perhaps there is a network problem. */
458 snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
459 host, strerror(errno));
460 buffer_append(&stderr_buffer, buf, strlen(buf));
461 quit_pending = 1;
462 return;
463 }
464 packet_process_incoming(buf, len);
465 }
466}
467
468/* process the characters one by one */
469int
470process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
471{
472 char string[1024];
473 pid_t pid;
474 int bytes = 0;
475 u_int i;
476 u_char ch;
477 char *s;
478
479 for (i = 0; i < len; i++) {
480 /* Get one character at a time. */
481 ch = buf[i];
482
483 if (escape_pending) {
484 /* We have previously seen an escape character. */
485 /* Clear the flag now. */
486 escape_pending = 0;
487
488 /* Process the escaped character. */
489 switch (ch) {
490 case '.':
491 /* Terminate the connection. */
492 snprintf(string, sizeof string, "%c.\r\n", escape_char);
493 buffer_append(berr, string, strlen(string));
494
495 quit_pending = 1;
496 return -1;
497
498 case 'Z' - 64:
499 /* Suspend the program. */
500 /* Print a message to that effect to the user. */
501 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
502 buffer_append(berr, string, strlen(string));
503
504 /* Restore terminal modes and suspend. */
505 client_suspend_self(bin, bout, berr);
506
507 /* We have been continued. */
508 continue;
509
510 case 'R':
511 if (compat20) {
512 if (datafellows & SSH_BUG_NOREKEY)
513 log("Server does not support re-keying");
514 else
515 need_rekeying = 1;
516 }
517 continue;
518
519 case '&':
520 /* XXX does not work yet with proto 2 */
521 if (compat20)
522 continue;
523 /*
524 * Detach the program (continue to serve connections,
525 * but put in background and no more new connections).
526 */
527 if (!stdin_eof) {
528 /*
529 * Sending SSH_CMSG_EOF alone does not always appear
530 * to be enough. So we try to send an EOF character
531 * first.
532 */
533 packet_start(SSH_CMSG_STDIN_DATA);
534 packet_put_string("\004", 1);
535 packet_send();
536 /* Close stdin. */
537 stdin_eof = 1;
538 if (buffer_len(bin) == 0) {
539 packet_start(SSH_CMSG_EOF);
540 packet_send();
541 }
542 }
543 /* Restore tty modes. */
544 leave_raw_mode();
545
546 /* Stop listening for new connections. */
547 channel_stop_listening();
548
549 printf("%c& [backgrounded]\n", escape_char);
550
551 /* Fork into background. */
552 pid = fork();
553 if (pid < 0) {
554 error("fork: %.100s", strerror(errno));
555 continue;
556 }
557 if (pid != 0) { /* This is the parent. */
558 /* The parent just exits. */
559 exit(0);
560 }
561 /* The child continues serving connections. */
562 continue; /*XXX ? */
563
564 case '?':
565 snprintf(string, sizeof string,
566"%c?\r\n\
567Supported escape sequences:\r\n\
568~. - terminate connection\r\n\
569~R - Request rekey (SSH protocol 2 only)\r\n\
570~^Z - suspend ssh\r\n\
571~# - list forwarded connections\r\n\
572~& - background ssh (when waiting for connections to terminate)\r\n\
573~? - this message\r\n\
574~~ - send the escape character by typing it twice\r\n\
575(Note that escapes are only recognized immediately after newline.)\r\n",
576 escape_char);
577 buffer_append(berr, string, strlen(string));
578 continue;
579
580 case '#':
581 snprintf(string, sizeof string, "%c#\r\n", escape_char);
582 buffer_append(berr, string, strlen(string));
583 s = channel_open_message();
584 buffer_append(berr, s, strlen(s));
585 xfree(s);
586 continue;
587
588 default:
589 if (ch != escape_char) {
590 buffer_put_char(bin, escape_char);
591 bytes++;
592 }
593 /* Escaped characters fall through here */
594 break;
595 }
596 } else {
597 /*
598 * The previous character was not an escape char. Check if this
599 * is an escape.
600 */
601 if (last_was_cr && ch == escape_char) {
602 /* It is. Set the flag and continue to next character. */
603 escape_pending = 1;
604 continue;
605 }
606 }
607
608 /*
609 * Normal character. Record whether it was a newline,
610 * and append it to the buffer.
611 */
612 last_was_cr = (ch == '\r' || ch == '\n');
613 buffer_put_char(bin, ch);
614 bytes++;
615 }
616 return bytes;
617}
618
619void
620client_process_input(fd_set * readset)
621{
622 int len;
623 char buf[8192];
624
625 /* Read input from stdin. */
626 if (FD_ISSET(fileno(stdin), readset)) {
627 /* Read as much as possible. */
628 len = read(fileno(stdin), buf, sizeof(buf));
629 if (len < 0 && (errno == EAGAIN || errno == EINTR))
630 return; /* we'll try again later */
631 if (len <= 0) {
632 /*
633 * Received EOF or error. They are treated
634 * similarly, except that an error message is printed
635 * if it was an error condition.
636 */
637 if (len < 0) {
638 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
639 buffer_append(&stderr_buffer, buf, strlen(buf));
640 }
641 /* Mark that we have seen EOF. */
642 stdin_eof = 1;
643 /*
644 * Send an EOF message to the server unless there is
645 * data in the buffer. If there is data in the
646 * buffer, no message will be sent now. Code
647 * elsewhere will send the EOF when the buffer
648 * becomes empty if stdin_eof is set.
649 */
650 if (buffer_len(&stdin_buffer) == 0) {
651 packet_start(SSH_CMSG_EOF);
652 packet_send();
653 }
654 } else if (escape_char == -1) {
655 /*
656 * Normal successful read, and no escape character.
657 * Just append the data to buffer.
658 */
659 buffer_append(&stdin_buffer, buf, len);
660 } else {
661 /*
662 * Normal, successful read. But we have an escape character
663 * and have to process the characters one by one.
664 */
665 if (process_escapes(&stdin_buffer, &stdout_buffer,
666 &stderr_buffer, buf, len) == -1)
667 return;
668 }
669 }
670}
671
672void
673client_process_output(fd_set * writeset)
674{
675 int len;
676 char buf[100];
677
678 /* Write buffered output to stdout. */
679 if (FD_ISSET(fileno(stdout), writeset)) {
680 /* Write as much data as possible. */
681 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
682 buffer_len(&stdout_buffer));
683 if (len <= 0) {
684 if (errno == EINTR || errno == EAGAIN)
685 len = 0;
686 else {
687 /*
688 * An error or EOF was encountered. Put an
689 * error message to stderr buffer.
690 */
691 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
692 buffer_append(&stderr_buffer, buf, strlen(buf));
693 quit_pending = 1;
694 return;
695 }
696 }
697 /* Consume printed data from the buffer. */
698 buffer_consume(&stdout_buffer, len);
699 stdout_bytes += len;
700 }
701 /* Write buffered output to stderr. */
702 if (FD_ISSET(fileno(stderr), writeset)) {
703 /* Write as much data as possible. */
704 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
705 buffer_len(&stderr_buffer));
706 if (len <= 0) {
707 if (errno == EINTR || errno == EAGAIN)
708 len = 0;
709 else {
710 /* EOF or error, but can't even print error message. */
711 quit_pending = 1;
712 return;
713 }
714 }
715 /* Consume printed characters from the buffer. */
716 buffer_consume(&stderr_buffer, len);
717 stderr_bytes += len;
718 }
719}
720
721/*
722 * Get packets from the connection input buffer, and process them as long as
723 * there are packets available.
724 *
725 * Any unknown packets received during the actual
726 * session cause the session to terminate. This is
727 * intended to make debugging easier since no
728 * confirmations are sent. Any compatible protocol
729 * extensions must be negotiated during the
730 * preparatory phase.
731 */
732
733void
734client_process_buffered_input_packets(void)
735{
736 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
737}
738
739/* scan buf[] for '~' before sending data to the peer */
740
741int
742simple_escape_filter(Channel *c, char *buf, int len)
743{
744 /* XXX we assume c->extended is writeable */
745 return process_escapes(&c->input, &c->output, &c->extended, buf, len);
746}
747
748void
749client_channel_closed(int id, void *arg)
750{
751 if (id != session_ident)
752 error("client_channel_closed: id %d != session_ident %d",
753 id, session_ident);
754 session_closed = 1;
755 if (in_raw_mode())
756 leave_raw_mode();
757}
758
759/*
760 * Implements the interactive session with the server. This is called after
761 * the user has been authenticated, and a command has been started on the
762 * remote host. If escape_char != -1, it is the character used as an escape
763 * character for terminating or suspending the session.
764 */
765
766int
767client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
768{
769 fd_set *readset = NULL, *writeset = NULL;
770 double start_time, total_time;
771 int max_fd = 0, len, rekeying = 0;
772 char buf[100];
773
774 debug("Entering interactive session.");
775
776 start_time = get_current_time();
777
778 /* Initialize variables. */
779 escape_pending = 0;
780 last_was_cr = 1;
781 exit_status = -1;
782 stdin_eof = 0;
783 buffer_high = 64 * 1024;
784 connection_in = packet_get_connection_in();
785 connection_out = packet_get_connection_out();
786 max_fd = MAX(connection_in, connection_out);
787
788 if (!compat20) {
789 /* enable nonblocking unless tty */
790 if (!isatty(fileno(stdin)))
791 set_nonblock(fileno(stdin));
792 if (!isatty(fileno(stdout)))
793 set_nonblock(fileno(stdout));
794 if (!isatty(fileno(stderr)))
795 set_nonblock(fileno(stderr));
796 max_fd = MAX(max_fd, fileno(stdin));
797 max_fd = MAX(max_fd, fileno(stdout));
798 max_fd = MAX(max_fd, fileno(stderr));
799 }
800 stdin_bytes = 0;
801 stdout_bytes = 0;
802 stderr_bytes = 0;
803 quit_pending = 0;
804 escape_char = escape_char_arg;
805
806 /* Initialize buffers. */
807 buffer_init(&stdin_buffer);
808 buffer_init(&stdout_buffer);
809 buffer_init(&stderr_buffer);
810
811 client_init_dispatch();
812
813 /* Set signal handlers to restore non-blocking mode. */
814 signal(SIGINT, signal_handler);
815 signal(SIGQUIT, signal_handler);
816 signal(SIGTERM, signal_handler);
817 signal(SIGPIPE, SIG_IGN);
818 if (have_pty)
819 signal(SIGWINCH, window_change_handler);
820
821 if (have_pty)
822 enter_raw_mode();
823
824 if (compat20) {
825 session_ident = ssh2_chan_id;
826 if (escape_char != -1)
827 channel_register_filter(session_ident,
828 simple_escape_filter);
829 if (session_ident != -1)
830 channel_register_cleanup(session_ident,
831 client_channel_closed);
832 } else {
833 /* Check if we should immediately send eof on stdin. */
834 client_check_initial_eof_on_stdin();
835 }
836
837 /* Main loop of the client for the interactive session mode. */
838 while (!quit_pending) {
839
840 /* Process buffered packets sent by the server. */
841 client_process_buffered_input_packets();
842
843 if (compat20 && session_closed && !channel_still_open())
844 break;
845
846 rekeying = (xxx_kex != NULL && !xxx_kex->done);
847
848 if (rekeying) {
849 debug("rekeying in progress");
850 } else {
851 /*
852 * Make packets of buffered stdin data, and buffer
853 * them for sending to the server.
854 */
855 if (!compat20)
856 client_make_packets_from_stdin_data();
857
858 /*
859 * Make packets from buffered channel data, and
860 * enqueue them for sending to the server.
861 */
862 if (packet_not_very_much_data_to_write())
863 channel_output_poll();
864
865 /*
866 * Check if the window size has changed, and buffer a
867 * message about it to the server if so.
868 */
869 client_check_window_change();
870
871 if (quit_pending)
872 break;
873 }
874 /*
875 * Wait until we have something to do (something becomes
876 * available on one of the descriptors).
877 */
878 client_wait_until_can_do_something(&readset, &writeset,
879 &max_fd, rekeying);
880
881 if (quit_pending)
882 break;
883
884 /* Do channel operations unless rekeying in progress. */
885 if (!rekeying) {
886 channel_after_select(readset, writeset);
887
888 if (need_rekeying) {
889 debug("user requests rekeying");
890 xxx_kex->done = 0;
891 kex_send_kexinit(xxx_kex);
892 need_rekeying = 0;
893 }
894 }
895
896 /* Buffer input from the connection. */
897 client_process_net_input(readset);
898
899 if (quit_pending)
900 break;
901
902 if (!compat20) {
903 /* Buffer data from stdin */
904 client_process_input(readset);
905 /*
906 * Process output to stdout and stderr. Output to
907 * the connection is processed elsewhere (above).
908 */
909 client_process_output(writeset);
910 }
911
912 /* Send as much buffered packet data as possible to the sender. */
913 if (FD_ISSET(connection_out, writeset))
914 packet_write_poll();
915 }
916 if (readset)
917 xfree(readset);
918 if (writeset)
919 xfree(writeset);
920
921 /* Terminate the session. */
922
923 /* Stop watching for window change. */
924 if (have_pty)
925 signal(SIGWINCH, SIG_DFL);
926
927 /* Stop listening for connections. */
928 channel_stop_listening();
929
930 /*
931 * In interactive mode (with pseudo tty) display a message indicating
932 * that the connection has been closed.
933 */
934 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
935 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
936 buffer_append(&stderr_buffer, buf, strlen(buf));
937 }
938 /* Output any buffered data for stdout. */
939 while (buffer_len(&stdout_buffer) > 0) {
940 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
941 buffer_len(&stdout_buffer));
942 if (len <= 0) {
943 error("Write failed flushing stdout buffer.");
944 break;
945 }
946 buffer_consume(&stdout_buffer, len);
947 stdout_bytes += len;
948 }
949
950 /* Output any buffered data for stderr. */
951 while (buffer_len(&stderr_buffer) > 0) {
952 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
953 buffer_len(&stderr_buffer));
954 if (len <= 0) {
955 error("Write failed flushing stderr buffer.");
956 break;
957 }
958 buffer_consume(&stderr_buffer, len);
959 stderr_bytes += len;
960 }
961
962 if (have_pty)
963 leave_raw_mode();
964
965 /* Clear and free any buffers. */
966 memset(buf, 0, sizeof(buf));
967 buffer_free(&stdin_buffer);
968 buffer_free(&stdout_buffer);
969 buffer_free(&stderr_buffer);
970
971 /* Report bytes transferred, and transfer rates. */
972 total_time = get_current_time() - start_time;
973 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
974 stdin_bytes, stdout_bytes, stderr_bytes, total_time);
975 if (total_time > 0)
976 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
977 stdin_bytes / total_time, stdout_bytes / total_time,
978 stderr_bytes / total_time);
979
980 /* Return the exit status of the program. */
981 debug("Exit status %d", exit_status);
982 return exit_status;
983}
984
985/*********/
986
987void
988client_input_stdout_data(int type, int plen, void *ctxt)
989{
990 u_int data_len;
991 char *data = packet_get_string(&data_len);
992 packet_integrity_check(plen, 4 + data_len, type);
993 buffer_append(&stdout_buffer, data, data_len);
994 memset(data, 0, data_len);
995 xfree(data);
996}
997void
998client_input_stderr_data(int type, int plen, void *ctxt)
999{
1000 u_int data_len;
1001 char *data = packet_get_string(&data_len);
1002 packet_integrity_check(plen, 4 + data_len, type);
1003 buffer_append(&stderr_buffer, data, data_len);
1004 memset(data, 0, data_len);
1005 xfree(data);
1006}
1007void
1008client_input_exit_status(int type, int plen, void *ctxt)
1009{
1010 packet_integrity_check(plen, 4, type);
1011 exit_status = packet_get_int();
1012 /* Acknowledge the exit. */
1013 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1014 packet_send();
1015 /*
1016 * Must wait for packet to be sent since we are
1017 * exiting the loop.
1018 */
1019 packet_write_wait();
1020 /* Flag that we want to exit. */
1021 quit_pending = 1;
1022}
1023
1024Channel *
1025client_request_forwarded_tcpip(const char *request_type, int rchan)
1026{
1027 Channel* c = NULL;
1028 char *listen_address, *originator_address;
1029 int listen_port, originator_port;
1030 int sock, newch;
1031
1032 /* Get rest of the packet */
1033 listen_address = packet_get_string(NULL);
1034 listen_port = packet_get_int();
1035 originator_address = packet_get_string(NULL);
1036 originator_port = packet_get_int();
1037 packet_done();
1038
1039 debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1040 listen_address, listen_port, originator_address, originator_port);
1041
1042 sock = channel_connect_by_listen_adress(listen_port);
1043 if (sock >= 0) {
1044 newch = channel_new("forwarded-tcpip",
1045 SSH_CHANNEL_CONNECTING, sock, sock, -1,
1046 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1047 xstrdup(originator_address), 1);
1048 c = channel_lookup(newch);
1049 }
1050 xfree(originator_address);
1051 xfree(listen_address);
1052 return c;
1053}
1054
1055Channel*
1056client_request_x11(const char *request_type, int rchan)
1057{
1058 Channel *c = NULL;
1059 char *originator;
1060 int originator_port;
1061 int sock, newch;
1062
1063 if (!options.forward_x11) {
1064 error("Warning: ssh server tried X11 forwarding.");
1065 error("Warning: this is probably a break in attempt by a malicious server.");
1066 return NULL;
1067 }
1068 originator = packet_get_string(NULL);
1069 if (datafellows & SSH_BUG_X11FWD) {
1070 debug2("buggy server: x11 request w/o originator_port");
1071 originator_port = 0;
1072 } else {
1073 originator_port = packet_get_int();
1074 }
1075 packet_done();
1076 /* XXX check permission */
1077 debug("client_request_x11: request from %s %d", originator,
1078 originator_port);
1079 sock = x11_connect_display();
1080 if (sock >= 0) {
1081 newch = channel_new("x11",
1082 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1083 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1084 xstrdup("x11"), 1);
1085 c = channel_lookup(newch);
1086 }
1087 xfree(originator);
1088 return c;
1089}
1090
1091Channel*
1092client_request_agent(const char *request_type, int rchan)
1093{
1094 Channel *c = NULL;
1095 int sock, newch;
1096
1097 if (!options.forward_agent) {
1098 error("Warning: ssh server tried agent forwarding.");
1099 error("Warning: this is probably a break in attempt by a malicious server.");
1100 return NULL;
1101 }
1102 sock = ssh_get_authentication_socket();
1103 if (sock >= 0) {
1104 newch = channel_new("authentication agent connection",
1105 SSH_CHANNEL_OPEN, sock, sock, -1,
1106 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1107 xstrdup("authentication agent connection"), 1);
1108 c = channel_lookup(newch);
1109 }
1110 return c;
1111}
1112
1113/* XXXX move to generic input handler */
1114void
1115client_input_channel_open(int type, int plen, void *ctxt)
1116{
1117 Channel *c = NULL;
1118 char *ctype;
1119 u_int len;
1120 int rchan;
1121 int rmaxpack;
1122 int rwindow;
1123
1124 ctype = packet_get_string(&len);
1125 rchan = packet_get_int();
1126 rwindow = packet_get_int();
1127 rmaxpack = packet_get_int();
1128
1129 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1130 ctype, rchan, rwindow, rmaxpack);
1131
1132 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1133 c = client_request_forwarded_tcpip(ctype, rchan);
1134 } else if (strcmp(ctype, "x11") == 0) {
1135 c = client_request_x11(ctype, rchan);
1136 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1137 c = client_request_agent(ctype, rchan);
1138 }
1139/* XXX duplicate : */
1140 if (c != NULL) {
1141 debug("confirm %s", ctype);
1142 c->remote_id = rchan;
1143 c->remote_window = rwindow;
1144 c->remote_maxpacket = rmaxpack;
1145
1146 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1147 packet_put_int(c->remote_id);
1148 packet_put_int(c->self);
1149 packet_put_int(c->local_window);
1150 packet_put_int(c->local_maxpacket);
1151 packet_send();
1152 } else {
1153 debug("failure %s", ctype);
1154 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1155 packet_put_int(rchan);
1156 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1157 packet_put_cstring("bla bla");
1158 packet_put_cstring("");
1159 packet_send();
1160 }
1161 xfree(ctype);
1162}
1163void
1164client_input_channel_req(int type, int plen, void *ctxt)
1165{
1166 Channel *c = NULL;
1167 int id, reply, success = 0;
1168 char *rtype;
1169
1170 id = packet_get_int();
1171 rtype = packet_get_string(NULL);
1172 reply = packet_get_char();
1173
1174 debug("client_input_channel_req: channel %d rtype %s reply %d",
1175 id, rtype, reply);
1176
1177 if (session_ident == -1) {
1178 error("client_input_channel_req: no channel %d", session_ident);
1179 } else if (id != session_ident) {
1180 error("client_input_channel_req: channel %d: wrong channel: %d",
1181 session_ident, id);
1182 }
1183 c = channel_lookup(id);
1184 if (c == NULL) {
1185 error("client_input_channel_req: channel %d: unknown channel", id);
1186 } else if (strcmp(rtype, "exit-status") == 0) {
1187 success = 1;
1188 exit_status = packet_get_int();
1189 packet_done();
1190 }
1191 if (reply) {
1192 packet_start(success ?
1193 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1194 packet_put_int(c->remote_id);
1195 packet_send();
1196 }
1197 xfree(rtype);
1198}
1199
1200void
1201client_init_dispatch_20(void)
1202{
1203 dispatch_init(&dispatch_protocol_error);
1204 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1205 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1206 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1207 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1208 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1209 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1210 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1211 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1212 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1213
1214 /* rekeying */
1215 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1216}
1217void
1218client_init_dispatch_13(void)
1219{
1220 dispatch_init(NULL);
1221 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1222 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1223 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1224 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1225 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1226 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1227 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1228 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1229 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1230
1231 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1232 &auth_input_open_request : &deny_input_open);
1233 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1234 &x11_input_open : &deny_input_open);
1235}
1236void
1237client_init_dispatch_15(void)
1238{
1239 client_init_dispatch_13();
1240 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1241 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1242}
1243void
1244client_init_dispatch(void)
1245{
1246 if (compat20)
1247 client_init_dispatch_20();
1248 else if (compat13)
1249 client_init_dispatch_13();
1250 else
1251 client_init_dispatch_15();
1252}