2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * The main loop for the interactive session (client side).
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".
14 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
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.
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.
37 * SSH2 support added by Markus Friedl.
38 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
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.
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.
62 RCSID("$OpenBSD: clientloop.c,v 1.93 2001/12/28 12:14:27 markus Exp $");
79 #include "clientloop.h"
86 extern Options options;
88 /* Flag indicating that stdin should be redirected from /dev/null. */
89 extern int stdin_null_flag;
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
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.
104 static volatile sig_atomic_t received_window_change_signal = 0;
105 static volatile sig_atomic_t received_signal = 0;
107 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
108 static int in_non_blocking_mode = 0;
110 /* Common data for the client loop code. */
111 static int quit_pending; /* Set to non-zero to quit the client loop. */
112 static int escape_char; /* Escape character. */
113 static int escape_pending; /* Last character was the escape character */
114 static int last_was_cr; /* Last character was a newline. */
115 static int exit_status; /* Used to store the exit status of the command. */
116 static int stdin_eof; /* EOF has been encountered on standard error. */
117 static Buffer stdin_buffer; /* Buffer for stdin data. */
118 static Buffer stdout_buffer; /* Buffer for stdout data. */
119 static Buffer stderr_buffer; /* Buffer for stderr data. */
120 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
121 static u_int buffer_high;/* Soft max buffer size. */
122 static int connection_in; /* Connection to server (input). */
123 static int connection_out; /* Connection to server (output). */
124 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
125 static int session_closed = 0; /* In SSH2: login session closed. */
127 static void client_init_dispatch(void);
128 int session_ident = -1;
133 /* Restores stdin to blocking mode. */
136 leave_non_blocking(void)
138 if (in_non_blocking_mode) {
139 (void) fcntl(fileno(stdin), F_SETFL, 0);
140 in_non_blocking_mode = 0;
141 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
145 /* Puts stdin terminal in non-blocking mode. */
148 enter_non_blocking(void)
150 in_non_blocking_mode = 1;
151 (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
152 fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
156 * Signal handler for the window change signal (SIGWINCH). This just sets a
157 * flag indicating that the window has changed.
161 window_change_handler(int sig)
163 received_window_change_signal = 1;
164 signal(SIGWINCH, window_change_handler);
168 * Signal handler for signals that cause the program to terminate. These
169 * signals must be trapped to restore terminal modes.
173 signal_handler(int sig)
175 received_signal = sig;
180 * Returns current time in seconds from Jan 1, 1970 with the maximum
181 * available resolution.
185 get_current_time(void)
188 gettimeofday(&tv, NULL);
189 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
193 * This is called when the interactive is entered. This checks if there is
194 * an EOF coming on stdin. We must check this explicitly, as select() does
195 * not appear to wake up when redirecting from /dev/null.
199 client_check_initial_eof_on_stdin(void)
205 * If standard input is to be "redirected from /dev/null", we simply
206 * mark that we have seen an EOF and send an EOF message to the
207 * server. Otherwise, we try to read a single character; it appears
208 * that for some files, such /dev/null, select() never wakes up for
209 * read for this descriptor, which means that we never get EOF. This
210 * way we will get the EOF if stdin comes from /dev/null or similar.
212 if (stdin_null_flag) {
213 /* Fake EOF on stdin. */
214 debug("Sending eof.");
216 packet_start(SSH_CMSG_EOF);
219 enter_non_blocking();
221 /* Check for immediate EOF on stdin. */
222 len = read(fileno(stdin), buf, 1);
224 /* EOF. Record that we have seen it and send EOF to server. */
225 debug("Sending eof.");
227 packet_start(SSH_CMSG_EOF);
229 } else if (len > 0) {
231 * Got data. We must store the data in the buffer,
232 * and also process it as an escape character if
235 if ((u_char) buf[0] == escape_char)
238 buffer_append(&stdin_buffer, buf, 1);
240 leave_non_blocking();
246 * Make packets from buffered stdin data, and buffer them for sending to the
251 client_make_packets_from_stdin_data(void)
255 /* Send buffered stdin data to the server. */
256 while (buffer_len(&stdin_buffer) > 0 &&
257 packet_not_very_much_data_to_write()) {
258 len = buffer_len(&stdin_buffer);
259 /* Keep the packets at reasonable size. */
260 if (len > packet_get_maxsize())
261 len = packet_get_maxsize();
262 packet_start(SSH_CMSG_STDIN_DATA);
263 packet_put_string(buffer_ptr(&stdin_buffer), len);
265 buffer_consume(&stdin_buffer, len);
267 /* If we have a pending EOF, send it now. */
268 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
269 packet_start(SSH_CMSG_EOF);
276 * Checks if the client window has changed, and sends a packet about it to
277 * the server if so. The actual change is detected elsewhere (by a software
278 * interrupt on Unix); this just checks the flag and sends a message if
283 client_check_window_change(void)
287 if (! received_window_change_signal)
290 received_window_change_signal = 0;
292 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
295 debug2("client_check_window_change: changed");
298 channel_request_start(session_ident, "window-change", 0);
299 packet_put_int(ws.ws_col);
300 packet_put_int(ws.ws_row);
301 packet_put_int(ws.ws_xpixel);
302 packet_put_int(ws.ws_ypixel);
305 packet_start(SSH_CMSG_WINDOW_SIZE);
306 packet_put_int(ws.ws_row);
307 packet_put_int(ws.ws_col);
308 packet_put_int(ws.ws_xpixel);
309 packet_put_int(ws.ws_ypixel);
315 * Waits until the client can do something (some data becomes available on
316 * one of the file descriptors).
320 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
321 int *maxfdp, int *nallocp, int rekeying)
323 /* Add any selections by the channel mechanism. */
324 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
327 /* Read from the connection, unless our buffers are full. */
328 if (buffer_len(&stdout_buffer) < buffer_high &&
329 buffer_len(&stderr_buffer) < buffer_high &&
330 channel_not_very_much_buffered_data())
331 FD_SET(connection_in, *readsetp);
333 * Read from stdin, unless we have seen EOF or have very much
334 * buffered data to send to the server.
336 if (!stdin_eof && packet_not_very_much_data_to_write())
337 FD_SET(fileno(stdin), *readsetp);
339 /* Select stdout/stderr if have data in buffer. */
340 if (buffer_len(&stdout_buffer) > 0)
341 FD_SET(fileno(stdout), *writesetp);
342 if (buffer_len(&stderr_buffer) > 0)
343 FD_SET(fileno(stderr), *writesetp);
345 /* channel_prepare_select could have closed the last channel */
346 if (session_closed && !channel_still_open() &&
347 !packet_have_data_to_write()) {
348 /* clear mask since we did not call select() */
349 memset(*readsetp, 0, *nallocp);
350 memset(*writesetp, 0, *nallocp);
353 FD_SET(connection_in, *readsetp);
357 /* Select server connection if have data to write to the server. */
358 if (packet_have_data_to_write())
359 FD_SET(connection_out, *writesetp);
362 * Wait for something to happen. This will suspend the process until
363 * some selected descriptor can be read, written, or has some other
364 * event pending. Note: if you want to implement SSH_MSG_IGNORE
365 * messages to fool traffic analysis, this might be the place to do
366 * it: just have a random timeout for the select, and send a random
367 * SSH_MSG_IGNORE packet when the timeout expires.
370 if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
374 * We have to clear the select masks, because we return.
375 * We have to return, because the mainloop checks for the flags
376 * set by the signal handlers.
378 memset(*readsetp, 0, *nallocp);
379 memset(*writesetp, 0, *nallocp);
383 /* Note: we might still have data in the buffers. */
384 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
385 buffer_append(&stderr_buffer, buf, strlen(buf));
391 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
393 struct winsize oldws, newws;
395 /* Flush stdout and stderr buffers. */
396 if (buffer_len(bout) > 0)
397 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
398 if (buffer_len(berr) > 0)
399 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
404 * Free (and clear) the buffer to reduce the amount of data that gets
411 /* Save old window size. */
412 ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
414 /* Send the suspend signal to the program itself. */
415 kill(getpid(), SIGTSTP);
417 /* Check if the window size has changed. */
418 if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
419 (oldws.ws_row != newws.ws_row ||
420 oldws.ws_col != newws.ws_col ||
421 oldws.ws_xpixel != newws.ws_xpixel ||
422 oldws.ws_ypixel != newws.ws_ypixel))
423 received_window_change_signal = 1;
425 /* OK, we have been continued by the user. Reinitialize buffers. */
434 client_process_net_input(fd_set * readset)
440 * Read input from the server, and add any such data to the buffer of
441 * the packet subsystem.
443 if (FD_ISSET(connection_in, readset)) {
444 /* Read as much as possible. */
445 len = read(connection_in, buf, sizeof(buf));
447 /* Received EOF. The remote host has closed the connection. */
448 snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
450 buffer_append(&stderr_buffer, buf, strlen(buf));
455 * There is a kernel bug on Solaris that causes select to
456 * sometimes wake up even though there is no data available.
458 if (len < 0 && (errno == EAGAIN || errno == EINTR))
462 /* An error has encountered. Perhaps there is a network problem. */
463 snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
464 host, strerror(errno));
465 buffer_append(&stderr_buffer, buf, strlen(buf));
469 packet_process_incoming(buf, len);
473 /* process the characters one by one */
475 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
484 for (i = 0; i < len; i++) {
485 /* Get one character at a time. */
488 if (escape_pending) {
489 /* We have previously seen an escape character. */
490 /* Clear the flag now. */
493 /* Process the escaped character. */
496 /* Terminate the connection. */
497 snprintf(string, sizeof string, "%c.\r\n", escape_char);
498 buffer_append(berr, string, strlen(string));
504 /* Suspend the program. */
505 /* Print a message to that effect to the user. */
506 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
507 buffer_append(berr, string, strlen(string));
509 /* Restore terminal modes and suspend. */
510 client_suspend_self(bin, bout, berr);
512 /* We have been continued. */
517 if (datafellows & SSH_BUG_NOREKEY)
518 log("Server does not support re-keying");
526 * Detach the program (continue to serve connections,
527 * but put in background and no more new connections).
529 /* Restore tty modes. */
532 /* Stop listening for new connections. */
533 channel_stop_listening();
535 snprintf(string, sizeof string,
536 "%c& [backgrounded]\n", escape_char);
537 buffer_append(berr, string, strlen(string));
539 /* Fork into background. */
542 error("fork: %.100s", strerror(errno));
545 if (pid != 0) { /* This is the parent. */
546 /* The parent just exits. */
549 /* The child continues serving connections. */
551 buffer_append(bin, "\004", 1);
552 /* fake EOF on stdin */
554 } else if (!stdin_eof) {
556 * Sending SSH_CMSG_EOF alone does not always appear
557 * to be enough. So we try to send an EOF character
560 packet_start(SSH_CMSG_STDIN_DATA);
561 packet_put_string("\004", 1);
565 if (buffer_len(bin) == 0) {
566 packet_start(SSH_CMSG_EOF);
573 snprintf(string, sizeof string,
575 Supported escape sequences:\r\n\
576 ~. - terminate connection\r\n\
577 ~R - Request rekey (SSH protocol 2 only)\r\n\
578 ~^Z - suspend ssh\r\n\
579 ~# - list forwarded connections\r\n\
580 ~& - background ssh (when waiting for connections to terminate)\r\n\
581 ~? - this message\r\n\
582 ~~ - send the escape character by typing it twice\r\n\
583 (Note that escapes are only recognized immediately after newline.)\r\n",
585 buffer_append(berr, string, strlen(string));
589 snprintf(string, sizeof string, "%c#\r\n", escape_char);
590 buffer_append(berr, string, strlen(string));
591 s = channel_open_message();
592 buffer_append(berr, s, strlen(s));
597 if (ch != escape_char) {
598 buffer_put_char(bin, escape_char);
601 /* Escaped characters fall through here */
606 * The previous character was not an escape char. Check if this
609 if (last_was_cr && ch == escape_char) {
610 /* It is. Set the flag and continue to next character. */
617 * Normal character. Record whether it was a newline,
618 * and append it to the buffer.
620 last_was_cr = (ch == '\r' || ch == '\n');
621 buffer_put_char(bin, ch);
628 client_process_input(fd_set * readset)
633 /* Read input from stdin. */
634 if (FD_ISSET(fileno(stdin), readset)) {
635 /* Read as much as possible. */
636 len = read(fileno(stdin), buf, sizeof(buf));
637 if (len < 0 && (errno == EAGAIN || errno == EINTR))
638 return; /* we'll try again later */
641 * Received EOF or error. They are treated
642 * similarly, except that an error message is printed
643 * if it was an error condition.
646 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
647 buffer_append(&stderr_buffer, buf, strlen(buf));
649 /* Mark that we have seen EOF. */
652 * Send an EOF message to the server unless there is
653 * data in the buffer. If there is data in the
654 * buffer, no message will be sent now. Code
655 * elsewhere will send the EOF when the buffer
656 * becomes empty if stdin_eof is set.
658 if (buffer_len(&stdin_buffer) == 0) {
659 packet_start(SSH_CMSG_EOF);
662 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
664 * Normal successful read, and no escape character.
665 * Just append the data to buffer.
667 buffer_append(&stdin_buffer, buf, len);
670 * Normal, successful read. But we have an escape character
671 * and have to process the characters one by one.
673 if (process_escapes(&stdin_buffer, &stdout_buffer,
674 &stderr_buffer, buf, len) == -1)
681 client_process_output(fd_set * writeset)
686 /* Write buffered output to stdout. */
687 if (FD_ISSET(fileno(stdout), writeset)) {
688 /* Write as much data as possible. */
689 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
690 buffer_len(&stdout_buffer));
692 if (errno == EINTR || errno == EAGAIN)
696 * An error or EOF was encountered. Put an
697 * error message to stderr buffer.
699 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
700 buffer_append(&stderr_buffer, buf, strlen(buf));
705 /* Consume printed data from the buffer. */
706 buffer_consume(&stdout_buffer, len);
709 /* Write buffered output to stderr. */
710 if (FD_ISSET(fileno(stderr), writeset)) {
711 /* Write as much data as possible. */
712 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
713 buffer_len(&stderr_buffer));
715 if (errno == EINTR || errno == EAGAIN)
718 /* EOF or error, but can't even print error message. */
723 /* Consume printed characters from the buffer. */
724 buffer_consume(&stderr_buffer, len);
730 * Get packets from the connection input buffer, and process them as long as
731 * there are packets available.
733 * Any unknown packets received during the actual
734 * session cause the session to terminate. This is
735 * intended to make debugging easier since no
736 * confirmations are sent. Any compatible protocol
737 * extensions must be negotiated during the
742 client_process_buffered_input_packets(void)
744 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
747 /* scan buf[] for '~' before sending data to the peer */
750 simple_escape_filter(Channel *c, char *buf, int len)
752 /* XXX we assume c->extended is writeable */
753 return process_escapes(&c->input, &c->output, &c->extended, buf, len);
757 client_channel_closed(int id, void *arg)
759 if (id != session_ident)
760 error("client_channel_closed: id %d != session_ident %d",
762 channel_cancel_cleanup(id);
769 * Implements the interactive session with the server. This is called after
770 * the user has been authenticated, and a command has been started on the
771 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
772 * used as an escape character for terminating or suspending the session.
776 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
778 fd_set *readset = NULL, *writeset = NULL;
779 double start_time, total_time;
780 int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
783 debug("Entering interactive session.");
785 start_time = get_current_time();
787 /* Initialize variables. */
792 buffer_high = 64 * 1024;
793 connection_in = packet_get_connection_in();
794 connection_out = packet_get_connection_out();
795 max_fd = MAX(connection_in, connection_out);
798 /* enable nonblocking unless tty */
799 if (!isatty(fileno(stdin)))
800 set_nonblock(fileno(stdin));
801 if (!isatty(fileno(stdout)))
802 set_nonblock(fileno(stdout));
803 if (!isatty(fileno(stderr)))
804 set_nonblock(fileno(stderr));
805 max_fd = MAX(max_fd, fileno(stdin));
806 max_fd = MAX(max_fd, fileno(stdout));
807 max_fd = MAX(max_fd, fileno(stderr));
813 escape_char = escape_char_arg;
815 /* Initialize buffers. */
816 buffer_init(&stdin_buffer);
817 buffer_init(&stdout_buffer);
818 buffer_init(&stderr_buffer);
820 client_init_dispatch();
822 /* Set signal handlers to restore non-blocking mode. */
823 signal(SIGINT, signal_handler);
824 signal(SIGQUIT, signal_handler);
825 signal(SIGTERM, signal_handler);
827 signal(SIGWINCH, window_change_handler);
833 session_ident = ssh2_chan_id;
834 if (escape_char != SSH_ESCAPECHAR_NONE)
835 channel_register_filter(session_ident,
836 simple_escape_filter);
837 if (session_ident != -1)
838 channel_register_cleanup(session_ident,
839 client_channel_closed);
841 /* Check if we should immediately send eof on stdin. */
842 client_check_initial_eof_on_stdin();
845 /* Main loop of the client for the interactive session mode. */
846 while (!quit_pending) {
848 /* Process buffered packets sent by the server. */
849 client_process_buffered_input_packets();
851 if (compat20 && session_closed && !channel_still_open())
854 rekeying = (xxx_kex != NULL && !xxx_kex->done);
857 debug("rekeying in progress");
860 * Make packets of buffered stdin data, and buffer
861 * them for sending to the server.
864 client_make_packets_from_stdin_data();
867 * Make packets from buffered channel data, and
868 * enqueue them for sending to the server.
870 if (packet_not_very_much_data_to_write())
871 channel_output_poll();
874 * Check if the window size has changed, and buffer a
875 * message about it to the server if so.
877 client_check_window_change();
883 * Wait until we have something to do (something becomes
884 * available on one of the descriptors).
887 client_wait_until_can_do_something(&readset, &writeset,
888 &max_fd2, &nalloc, rekeying);
893 /* Do channel operations unless rekeying in progress. */
895 channel_after_select(readset, writeset);
898 debug("user requests rekeying");
900 kex_send_kexinit(xxx_kex);
905 /* Buffer input from the connection. */
906 client_process_net_input(readset);
912 /* Buffer data from stdin */
913 client_process_input(readset);
915 * Process output to stdout and stderr. Output to
916 * the connection is processed elsewhere (above).
918 client_process_output(writeset);
921 /* Send as much buffered packet data as possible to the sender. */
922 if (FD_ISSET(connection_out, writeset))
930 /* Terminate the session. */
932 /* Stop watching for window change. */
934 signal(SIGWINCH, SIG_DFL);
941 /* restore blocking io */
942 if (!isatty(fileno(stdin)))
943 unset_nonblock(fileno(stdin));
944 if (!isatty(fileno(stdout)))
945 unset_nonblock(fileno(stdout));
946 if (!isatty(fileno(stderr)))
947 unset_nonblock(fileno(stderr));
949 if (received_signal) {
950 if (in_non_blocking_mode) /* XXX */
951 leave_non_blocking();
952 fatal("Killed by signal %d.", (int) received_signal);
956 * In interactive mode (with pseudo tty) display a message indicating
957 * that the connection has been closed.
959 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
960 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
961 buffer_append(&stderr_buffer, buf, strlen(buf));
964 /* Output any buffered data for stdout. */
965 while (buffer_len(&stdout_buffer) > 0) {
966 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
967 buffer_len(&stdout_buffer));
969 error("Write failed flushing stdout buffer.");
972 buffer_consume(&stdout_buffer, len);
976 /* Output any buffered data for stderr. */
977 while (buffer_len(&stderr_buffer) > 0) {
978 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
979 buffer_len(&stderr_buffer));
981 error("Write failed flushing stderr buffer.");
984 buffer_consume(&stderr_buffer, len);
988 /* Clear and free any buffers. */
989 memset(buf, 0, sizeof(buf));
990 buffer_free(&stdin_buffer);
991 buffer_free(&stdout_buffer);
992 buffer_free(&stderr_buffer);
994 /* Report bytes transferred, and transfer rates. */
995 total_time = get_current_time() - start_time;
996 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
997 stdin_bytes, stdout_bytes, stderr_bytes, total_time);
999 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1000 stdin_bytes / total_time, stdout_bytes / total_time,
1001 stderr_bytes / total_time);
1003 /* Return the exit status of the program. */
1004 debug("Exit status %d", exit_status);
1011 client_input_stdout_data(int type, int plen, u_int32_t seq, void *ctxt)
1014 char *data = packet_get_string(&data_len);
1016 buffer_append(&stdout_buffer, data, data_len);
1017 memset(data, 0, data_len);
1021 client_input_stderr_data(int type, int plen, u_int32_t seq, void *ctxt)
1024 char *data = packet_get_string(&data_len);
1026 buffer_append(&stderr_buffer, data, data_len);
1027 memset(data, 0, data_len);
1031 client_input_exit_status(int type, int plen, u_int32_t seq, void *ctxt)
1033 exit_status = packet_get_int();
1035 /* Acknowledge the exit. */
1036 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1039 * Must wait for packet to be sent since we are
1042 packet_write_wait();
1043 /* Flag that we want to exit. */
1048 client_request_forwarded_tcpip(const char *request_type, int rchan)
1051 char *listen_address, *originator_address;
1052 int listen_port, originator_port;
1055 /* Get rest of the packet */
1056 listen_address = packet_get_string(NULL);
1057 listen_port = packet_get_int();
1058 originator_address = packet_get_string(NULL);
1059 originator_port = packet_get_int();
1062 debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1063 listen_address, listen_port, originator_address, originator_port);
1065 sock = channel_connect_by_listen_address(listen_port);
1067 xfree(originator_address);
1068 xfree(listen_address);
1071 c = channel_new("forwarded-tcpip",
1072 SSH_CHANNEL_CONNECTING, sock, sock, -1,
1073 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1074 xstrdup(originator_address), 1);
1076 error("client_request_forwarded_tcpip: channel_new failed");
1079 xfree(originator_address);
1080 xfree(listen_address);
1085 client_request_x11(const char *request_type, int rchan)
1089 int originator_port;
1092 if (!options.forward_x11) {
1093 error("Warning: ssh server tried X11 forwarding.");
1094 error("Warning: this is probably a break in attempt by a malicious server.");
1097 originator = packet_get_string(NULL);
1098 if (datafellows & SSH_BUG_X11FWD) {
1099 debug2("buggy server: x11 request w/o originator_port");
1100 originator_port = 0;
1102 originator_port = packet_get_int();
1105 /* XXX check permission */
1106 debug("client_request_x11: request from %s %d", originator,
1109 sock = x11_connect_display();
1112 c = channel_new("x11",
1113 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1114 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1117 error("client_request_x11: channel_new failed");
1125 client_request_agent(const char *request_type, int rchan)
1130 if (!options.forward_agent) {
1131 error("Warning: ssh server tried agent forwarding.");
1132 error("Warning: this is probably a break in attempt by a malicious server.");
1135 sock = ssh_get_authentication_socket();
1138 c = channel_new("authentication agent connection",
1139 SSH_CHANNEL_OPEN, sock, sock, -1,
1140 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1141 xstrdup("authentication agent connection"), 1);
1143 error("client_request_agent: channel_new failed");
1150 /* XXXX move to generic input handler */
1152 client_input_channel_open(int type, int plen, u_int32_t seq, void *ctxt)
1161 ctype = packet_get_string(&len);
1162 rchan = packet_get_int();
1163 rwindow = packet_get_int();
1164 rmaxpack = packet_get_int();
1166 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1167 ctype, rchan, rwindow, rmaxpack);
1169 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1170 c = client_request_forwarded_tcpip(ctype, rchan);
1171 } else if (strcmp(ctype, "x11") == 0) {
1172 c = client_request_x11(ctype, rchan);
1173 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1174 c = client_request_agent(ctype, rchan);
1176 /* XXX duplicate : */
1178 debug("confirm %s", ctype);
1179 c->remote_id = rchan;
1180 c->remote_window = rwindow;
1181 c->remote_maxpacket = rmaxpack;
1182 if (c->type != SSH_CHANNEL_CONNECTING) {
1183 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1184 packet_put_int(c->remote_id);
1185 packet_put_int(c->self);
1186 packet_put_int(c->local_window);
1187 packet_put_int(c->local_maxpacket);
1191 debug("failure %s", ctype);
1192 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1193 packet_put_int(rchan);
1194 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1195 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1196 packet_put_cstring("open failed");
1197 packet_put_cstring("");
1204 client_input_channel_req(int type, int plen, u_int32_t seq, void *ctxt)
1207 int id, reply, success = 0;
1210 id = packet_get_int();
1211 rtype = packet_get_string(NULL);
1212 reply = packet_get_char();
1214 debug("client_input_channel_req: channel %d rtype %s reply %d",
1217 if (session_ident == -1) {
1218 error("client_input_channel_req: no channel %d", session_ident);
1219 } else if (id != session_ident) {
1220 error("client_input_channel_req: channel %d: wrong channel: %d",
1223 c = channel_lookup(id);
1225 error("client_input_channel_req: channel %d: unknown channel", id);
1226 } else if (strcmp(rtype, "exit-status") == 0) {
1228 exit_status = packet_get_int();
1232 packet_start(success ?
1233 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1234 packet_put_int(c->remote_id);
1241 client_init_dispatch_20(void)
1243 dispatch_init(&dispatch_protocol_error);
1244 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1245 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1246 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1247 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1248 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1249 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1250 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1251 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1252 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1255 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1258 client_init_dispatch_13(void)
1260 dispatch_init(NULL);
1261 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1262 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1263 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1264 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1265 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1266 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1267 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1268 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1269 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1271 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1272 &auth_input_open_request : &deny_input_open);
1273 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1274 &x11_input_open : &deny_input_open);
1277 client_init_dispatch_15(void)
1279 client_init_dispatch_13();
1280 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1281 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1284 client_init_dispatch(void)
1287 client_init_dispatch_20();
1289 client_init_dispatch_13();
1291 client_init_dispatch_15();