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 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 1.60 2001/04/05 21:05:23 markus Exp $");
79 #include "clientloop.h"
84 extern Options options;
86 /* Flag indicating that stdin should be redirected from /dev/null. */
87 extern int stdin_null_flag;
90 * Name of the host we are connecting to. This is the name given on the
91 * command line, or the HostName specified for the user-supplied name in a
97 * Flag to indicate that we have received a window change signal which has
98 * not yet been processed. This will cause a message indicating the new
99 * window size to be sent to the server a little later. This is volatile
100 * because this is updated in a signal handler.
102 static volatile int received_window_change_signal = 0;
104 /* Terminal modes, as saved by enter_raw_mode. */
105 static struct termios saved_tio;
108 * Flag indicating whether we are in raw mode. This is used by
109 * enter_raw_mode and leave_raw_mode.
111 static int in_raw_mode = 0;
113 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
114 static int in_non_blocking_mode = 0;
116 /* Common data for the client loop code. */
117 static int quit_pending; /* Set to non-zero to quit the client loop. */
118 static int escape_char; /* Escape character. */
119 static int escape_pending; /* Last character was the escape character */
120 static int last_was_cr; /* Last character was a newline. */
121 static int exit_status; /* Used to store the exit status of the command. */
122 static int stdin_eof; /* EOF has been encountered on standard error. */
123 static Buffer stdin_buffer; /* Buffer for stdin data. */
124 static Buffer stdout_buffer; /* Buffer for stdout data. */
125 static Buffer stderr_buffer; /* Buffer for stderr data. */
126 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
127 static u_int buffer_high;/* Soft max buffer size. */
128 static int connection_in; /* Connection to server (input). */
129 static int connection_out; /* Connection to server (output). */
130 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
131 static int session_closed = 0; /* In SSH2: login session closed. */
133 void client_init_dispatch(void);
134 int session_ident = -1;
139 /* Returns the user\'s terminal to normal mode if it had been put in raw mode. */
147 if (tcsetattr(fileno(stdin), TCSADRAIN, &saved_tio) < 0)
150 fatal_remove_cleanup((void (*) (void *)) leave_raw_mode, NULL);
153 /* Puts the user\'s terminal in raw mode. */
160 if (tcgetattr(fileno(stdin), &tio) < 0)
163 tio.c_iflag |= IGNPAR;
164 tio.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
165 tio.c_lflag &= ~(ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
167 tio.c_lflag &= ~IEXTEN;
169 tio.c_oflag &= ~OPOST;
172 if (tcsetattr(fileno(stdin), TCSADRAIN, &tio) < 0)
176 fatal_add_cleanup((void (*) (void *)) leave_raw_mode, NULL);
179 /* Restores stdin to blocking mode. */
182 leave_non_blocking(void)
184 if (in_non_blocking_mode) {
185 (void) fcntl(fileno(stdin), F_SETFL, 0);
186 in_non_blocking_mode = 0;
187 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
191 /* Puts stdin terminal in non-blocking mode. */
194 enter_non_blocking(void)
196 in_non_blocking_mode = 1;
197 (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
198 fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
202 * Signal handler for the window change signal (SIGWINCH). This just sets a
203 * flag indicating that the window has changed.
207 window_change_handler(int sig)
209 received_window_change_signal = 1;
210 signal(SIGWINCH, window_change_handler);
214 * Signal handler for signals that cause the program to terminate. These
215 * signals must be trapped to restore terminal modes.
219 signal_handler(int sig)
223 if (in_non_blocking_mode)
224 leave_non_blocking();
225 channel_stop_listening();
227 fatal("Killed by signal %d.", sig);
231 * Returns current time in seconds from Jan 1, 1970 with the maximum
232 * available resolution.
236 get_current_time(void)
239 gettimeofday(&tv, NULL);
240 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
244 * This is called when the interactive is entered. This checks if there is
245 * an EOF coming on stdin. We must check this explicitly, as select() does
246 * not appear to wake up when redirecting from /dev/null.
250 client_check_initial_eof_on_stdin(void)
256 * If standard input is to be "redirected from /dev/null", we simply
257 * mark that we have seen an EOF and send an EOF message to the
258 * server. Otherwise, we try to read a single character; it appears
259 * that for some files, such /dev/null, select() never wakes up for
260 * read for this descriptor, which means that we never get EOF. This
261 * way we will get the EOF if stdin comes from /dev/null or similar.
263 if (stdin_null_flag) {
264 /* Fake EOF on stdin. */
265 debug("Sending eof.");
267 packet_start(SSH_CMSG_EOF);
270 enter_non_blocking();
272 /* Check for immediate EOF on stdin. */
273 len = read(fileno(stdin), buf, 1);
275 /* EOF. Record that we have seen it and send EOF to server. */
276 debug("Sending eof.");
278 packet_start(SSH_CMSG_EOF);
280 } else if (len > 0) {
282 * Got data. We must store the data in the buffer,
283 * and also process it as an escape character if
286 if ((u_char) buf[0] == escape_char)
289 buffer_append(&stdin_buffer, buf, 1);
291 leave_non_blocking();
297 * Make packets from buffered stdin data, and buffer them for sending to the
302 client_make_packets_from_stdin_data(void)
306 /* Send buffered stdin data to the server. */
307 while (buffer_len(&stdin_buffer) > 0 &&
308 packet_not_very_much_data_to_write()) {
309 len = buffer_len(&stdin_buffer);
310 /* Keep the packets at reasonable size. */
311 if (len > packet_get_maxsize())
312 len = packet_get_maxsize();
313 packet_start(SSH_CMSG_STDIN_DATA);
314 packet_put_string(buffer_ptr(&stdin_buffer), len);
316 buffer_consume(&stdin_buffer, len);
318 /* If we have a pending EOF, send it now. */
319 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
320 packet_start(SSH_CMSG_EOF);
327 * Checks if the client window has changed, and sends a packet about it to
328 * the server if so. The actual change is detected elsewhere (by a software
329 * interrupt on Unix); this just checks the flag and sends a message if
334 client_check_window_change(void)
338 if (! received_window_change_signal)
341 received_window_change_signal = 0;
343 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
346 debug2("client_check_window_change: changed");
349 channel_request_start(session_ident, "window-change", 0);
350 packet_put_int(ws.ws_col);
351 packet_put_int(ws.ws_row);
352 packet_put_int(ws.ws_xpixel);
353 packet_put_int(ws.ws_ypixel);
356 packet_start(SSH_CMSG_WINDOW_SIZE);
357 packet_put_int(ws.ws_row);
358 packet_put_int(ws.ws_col);
359 packet_put_int(ws.ws_xpixel);
360 packet_put_int(ws.ws_ypixel);
366 * Waits until the client can do something (some data becomes available on
367 * one of the file descriptors).
371 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
372 int *maxfdp, int rekeying)
374 /* Add any selections by the channel mechanism. */
375 channel_prepare_select(readsetp, writesetp, maxfdp, rekeying);
378 /* Read from the connection, unless our buffers are full. */
379 if (buffer_len(&stdout_buffer) < buffer_high &&
380 buffer_len(&stderr_buffer) < buffer_high &&
381 channel_not_very_much_buffered_data())
382 FD_SET(connection_in, *readsetp);
384 * Read from stdin, unless we have seen EOF or have very much
385 * buffered data to send to the server.
387 if (!stdin_eof && packet_not_very_much_data_to_write())
388 FD_SET(fileno(stdin), *readsetp);
390 /* Select stdout/stderr if have data in buffer. */
391 if (buffer_len(&stdout_buffer) > 0)
392 FD_SET(fileno(stdout), *writesetp);
393 if (buffer_len(&stderr_buffer) > 0)
394 FD_SET(fileno(stderr), *writesetp);
396 FD_SET(connection_in, *readsetp);
399 /* Select server connection if have data to write to the server. */
400 if (packet_have_data_to_write())
401 FD_SET(connection_out, *writesetp);
404 * Wait for something to happen. This will suspend the process until
405 * some selected descriptor can be read, written, or has some other
406 * event pending. Note: if you want to implement SSH_MSG_IGNORE
407 * messages to fool traffic analysis, this might be the place to do
408 * it: just have a random timeout for the select, and send a random
409 * SSH_MSG_IGNORE packet when the timeout expires.
412 if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
416 * We have to clear the select masks, because we return.
417 * We have to return, because the mainloop checks for the flags
418 * set by the signal handlers.
420 memset(*readsetp, 0, *maxfdp);
421 memset(*writesetp, 0, *maxfdp);
425 /* Note: we might still have data in the buffers. */
426 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
427 buffer_append(&stderr_buffer, buf, strlen(buf));
433 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
435 struct winsize oldws, newws;
437 /* Flush stdout and stderr buffers. */
438 if (buffer_len(bout) > 0)
439 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
440 if (buffer_len(berr) > 0)
441 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
446 * Free (and clear) the buffer to reduce the amount of data that gets
453 /* Save old window size. */
454 ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
456 /* Send the suspend signal to the program itself. */
457 kill(getpid(), SIGTSTP);
459 /* Check if the window size has changed. */
460 if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
461 (oldws.ws_row != newws.ws_row ||
462 oldws.ws_col != newws.ws_col ||
463 oldws.ws_xpixel != newws.ws_xpixel ||
464 oldws.ws_ypixel != newws.ws_ypixel))
465 received_window_change_signal = 1;
467 /* OK, we have been continued by the user. Reinitialize buffers. */
476 client_process_net_input(fd_set * readset)
482 * Read input from the server, and add any such data to the buffer of
483 * the packet subsystem.
485 if (FD_ISSET(connection_in, readset)) {
486 /* Read as much as possible. */
487 len = read(connection_in, buf, sizeof(buf));
489 /* Received EOF. The remote host has closed the connection. */
490 snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
492 buffer_append(&stderr_buffer, buf, strlen(buf));
497 * There is a kernel bug on Solaris that causes select to
498 * sometimes wake up even though there is no data available.
500 if (len < 0 && (errno == EAGAIN || errno == EINTR))
504 /* An error has encountered. Perhaps there is a network problem. */
505 snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
506 host, strerror(errno));
507 buffer_append(&stderr_buffer, buf, strlen(buf));
511 packet_process_incoming(buf, len);
515 /* process the characters one by one */
517 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
526 for (i = 0; i < len; i++) {
527 /* Get one character at a time. */
530 if (escape_pending) {
531 /* We have previously seen an escape character. */
532 /* Clear the flag now. */
535 /* Process the escaped character. */
538 /* Terminate the connection. */
539 snprintf(string, sizeof string, "%c.\r\n", escape_char);
540 buffer_append(berr, string, strlen(string));
546 /* Suspend the program. */
547 /* Print a message to that effect to the user. */
548 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
549 buffer_append(berr, string, strlen(string));
551 /* Restore terminal modes and suspend. */
552 client_suspend_self(bin, bout, berr);
554 /* We have been continued. */
559 if (datafellows & SSH_BUG_NOREKEY)
560 log("Server does not support re-keying");
567 /* XXX does not work yet with proto 2 */
571 * Detach the program (continue to serve connections,
572 * but put in background and no more new connections).
576 * Sending SSH_CMSG_EOF alone does not always appear
577 * to be enough. So we try to send an EOF character
580 packet_start(SSH_CMSG_STDIN_DATA);
581 packet_put_string("\004", 1);
585 if (buffer_len(bin) == 0) {
586 packet_start(SSH_CMSG_EOF);
590 /* Restore tty modes. */
593 /* Stop listening for new connections. */
594 channel_stop_listening();
596 printf("%c& [backgrounded]\n", escape_char);
598 /* Fork into background. */
601 error("fork: %.100s", strerror(errno));
604 if (pid != 0) { /* This is the parent. */
605 /* The parent just exits. */
608 /* The child continues serving connections. */
612 snprintf(string, sizeof string,
614 Supported escape sequences:\r\n\
615 ~. - terminate connection\r\n\
616 ~^Z - suspend ssh\r\n\
617 ~# - list forwarded connections\r\n\
618 ~& - background ssh (when waiting for connections to terminate)\r\n\
619 ~? - this message\r\n\
620 ~~ - send the escape character by typing it twice\r\n\
621 (Note that escapes are only recognized immediately after newline.)\r\n",
623 buffer_append(berr, string, strlen(string));
627 snprintf(string, sizeof string, "%c#\r\n", escape_char);
628 buffer_append(berr, string, strlen(string));
629 s = channel_open_message();
630 buffer_append(berr, s, strlen(s));
635 if (ch != escape_char) {
636 buffer_put_char(bin, escape_char);
639 /* Escaped characters fall through here */
644 * The previous character was not an escape char. Check if this
647 if (last_was_cr && ch == escape_char) {
648 /* It is. Set the flag and continue to next character. */
655 * Normal character. Record whether it was a newline,
656 * and append it to the buffer.
658 last_was_cr = (ch == '\r' || ch == '\n');
659 buffer_put_char(bin, ch);
666 client_process_input(fd_set * readset)
671 /* Read input from stdin. */
672 if (FD_ISSET(fileno(stdin), readset)) {
673 /* Read as much as possible. */
674 len = read(fileno(stdin), buf, sizeof(buf));
677 * Received EOF or error. They are treated
678 * similarly, except that an error message is printed
679 * if it was an error condition.
682 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
683 buffer_append(&stderr_buffer, buf, strlen(buf));
685 /* Mark that we have seen EOF. */
688 * Send an EOF message to the server unless there is
689 * data in the buffer. If there is data in the
690 * buffer, no message will be sent now. Code
691 * elsewhere will send the EOF when the buffer
692 * becomes empty if stdin_eof is set.
694 if (buffer_len(&stdin_buffer) == 0) {
695 packet_start(SSH_CMSG_EOF);
698 } else if (escape_char == -1) {
700 * Normal successful read, and no escape character.
701 * Just append the data to buffer.
703 buffer_append(&stdin_buffer, buf, len);
706 * Normal, successful read. But we have an escape character
707 * and have to process the characters one by one.
709 if (process_escapes(&stdin_buffer, &stdout_buffer,
710 &stderr_buffer, buf, len) == -1)
717 client_process_output(fd_set * writeset)
722 /* Write buffered output to stdout. */
723 if (FD_ISSET(fileno(stdout), writeset)) {
724 /* Write as much data as possible. */
725 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
726 buffer_len(&stdout_buffer));
732 * An error or EOF was encountered. Put an
733 * error message to stderr buffer.
735 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
736 buffer_append(&stderr_buffer, buf, strlen(buf));
741 /* Consume printed data from the buffer. */
742 buffer_consume(&stdout_buffer, len);
745 /* Write buffered output to stderr. */
746 if (FD_ISSET(fileno(stderr), writeset)) {
747 /* Write as much data as possible. */
748 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
749 buffer_len(&stderr_buffer));
754 /* EOF or error, but can't even print error message. */
759 /* Consume printed characters from the buffer. */
760 buffer_consume(&stderr_buffer, len);
766 * Get packets from the connection input buffer, and process them as long as
767 * there are packets available.
769 * Any unknown packets received during the actual
770 * session cause the session to terminate. This is
771 * intended to make debugging easier since no
772 * confirmations are sent. Any compatible protocol
773 * extensions must be negotiated during the
778 client_process_buffered_input_packets(void)
780 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
783 /* scan buf[] for '~' before sending data to the peer */
786 simple_escape_filter(Channel *c, char *buf, int len)
788 /* XXX we assume c->extended is writeable */
789 return process_escapes(&c->input, &c->output, &c->extended, buf, len);
793 client_channel_closed(int id, void *arg)
795 if (id != session_ident)
796 error("client_channel_closed: id %d != session_ident %d",
802 * Implements the interactive session with the server. This is called after
803 * the user has been authenticated, and a command has been started on the
804 * remote host. If escape_char != -1, it is the character used as an escape
805 * character for terminating or suspending the session.
809 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
811 fd_set *readset = NULL, *writeset = NULL;
812 double start_time, total_time;
813 int max_fd = 0, len, rekeying = 0;
816 debug("Entering interactive session.");
818 start_time = get_current_time();
820 /* Initialize variables. */
825 buffer_high = 64 * 1024;
826 connection_in = packet_get_connection_in();
827 connection_out = packet_get_connection_out();
828 max_fd = MAX(connection_in, connection_out);
831 max_fd = MAX(max_fd, fileno(stdin));
832 max_fd = MAX(max_fd, fileno(stdout));
833 max_fd = MAX(max_fd, fileno(stderr));
839 escape_char = escape_char_arg;
841 /* Initialize buffers. */
842 buffer_init(&stdin_buffer);
843 buffer_init(&stdout_buffer);
844 buffer_init(&stderr_buffer);
846 client_init_dispatch();
848 /* Set signal handlers to restore non-blocking mode. */
849 signal(SIGINT, signal_handler);
850 signal(SIGQUIT, signal_handler);
851 signal(SIGTERM, signal_handler);
852 signal(SIGPIPE, SIG_IGN);
854 signal(SIGWINCH, window_change_handler);
860 session_ident = ssh2_chan_id;
861 if (escape_char != -1)
862 channel_register_filter(session_ident,
863 simple_escape_filter);
864 if (session_ident != -1)
865 channel_register_cleanup(session_ident,
866 client_channel_closed);
868 /* Check if we should immediately send eof on stdin. */
869 client_check_initial_eof_on_stdin();
872 /* Main loop of the client for the interactive session mode. */
873 while (!quit_pending) {
875 /* Process buffered packets sent by the server. */
876 client_process_buffered_input_packets();
878 if (compat20 && session_closed && !channel_still_open())
881 rekeying = (xxx_kex != NULL && !xxx_kex->done);
884 debug("rekeying in progress");
887 * Make packets of buffered stdin data, and buffer
888 * them for sending to the server.
891 client_make_packets_from_stdin_data();
894 * Make packets from buffered channel data, and
895 * enqueue them for sending to the server.
897 if (packet_not_very_much_data_to_write())
898 channel_output_poll();
901 * Check if the window size has changed, and buffer a
902 * message about it to the server if so.
904 client_check_window_change();
910 * Wait until we have something to do (something becomes
911 * available on one of the descriptors).
913 client_wait_until_can_do_something(&readset, &writeset,
919 /* Do channel operations unless rekeying in progress. */
921 channel_after_select(readset, writeset);
924 debug("user requests rekeying");
926 kex_send_kexinit(xxx_kex);
931 /* Buffer input from the connection. */
932 client_process_net_input(readset);
938 /* Buffer data from stdin */
939 client_process_input(readset);
941 * Process output to stdout and stderr. Output to
942 * the connection is processed elsewhere (above).
944 client_process_output(writeset);
947 /* Send as much buffered packet data as possible to the sender. */
948 if (FD_ISSET(connection_out, writeset))
956 /* Terminate the session. */
958 /* Stop watching for window change. */
960 signal(SIGWINCH, SIG_DFL);
962 /* Stop listening for connections. */
963 channel_stop_listening();
966 * In interactive mode (with pseudo tty) display a message indicating
967 * that the connection has been closed.
969 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
970 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
971 buffer_append(&stderr_buffer, buf, strlen(buf));
973 /* Output any buffered data for stdout. */
974 while (buffer_len(&stdout_buffer) > 0) {
975 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
976 buffer_len(&stdout_buffer));
978 error("Write failed flushing stdout buffer.");
981 buffer_consume(&stdout_buffer, len);
985 /* Output any buffered data for stderr. */
986 while (buffer_len(&stderr_buffer) > 0) {
987 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
988 buffer_len(&stderr_buffer));
990 error("Write failed flushing stderr buffer.");
993 buffer_consume(&stderr_buffer, len);
1000 /* Clear and free any buffers. */
1001 memset(buf, 0, sizeof(buf));
1002 buffer_free(&stdin_buffer);
1003 buffer_free(&stdout_buffer);
1004 buffer_free(&stderr_buffer);
1006 /* Report bytes transferred, and transfer rates. */
1007 total_time = get_current_time() - start_time;
1008 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1009 stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1011 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1012 stdin_bytes / total_time, stdout_bytes / total_time,
1013 stderr_bytes / total_time);
1015 /* Return the exit status of the program. */
1016 debug("Exit status %d", exit_status);
1023 client_input_stdout_data(int type, int plen, void *ctxt)
1026 char *data = packet_get_string(&data_len);
1027 packet_integrity_check(plen, 4 + data_len, type);
1028 buffer_append(&stdout_buffer, data, data_len);
1029 memset(data, 0, data_len);
1033 client_input_stderr_data(int type, int plen, void *ctxt)
1036 char *data = packet_get_string(&data_len);
1037 packet_integrity_check(plen, 4 + data_len, type);
1038 buffer_append(&stderr_buffer, data, data_len);
1039 memset(data, 0, data_len);
1043 client_input_exit_status(int type, int plen, void *ctxt)
1045 packet_integrity_check(plen, 4, type);
1046 exit_status = packet_get_int();
1047 /* Acknowledge the exit. */
1048 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1051 * Must wait for packet to be sent since we are
1054 packet_write_wait();
1055 /* Flag that we want to exit. */
1060 client_request_forwarded_tcpip(const char *request_type, int rchan)
1063 char *listen_address, *originator_address;
1064 int listen_port, originator_port;
1067 /* Get rest of the packet */
1068 listen_address = packet_get_string(NULL);
1069 listen_port = packet_get_int();
1070 originator_address = packet_get_string(NULL);
1071 originator_port = packet_get_int();
1074 debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1075 listen_address, listen_port, originator_address, originator_port);
1077 sock = channel_connect_by_listen_adress(listen_port);
1079 newch = channel_new("forwarded-tcpip",
1080 SSH_CHANNEL_CONNECTING, sock, sock, -1,
1081 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1082 xstrdup(originator_address), 1);
1083 c = channel_lookup(newch);
1085 xfree(originator_address);
1086 xfree(listen_address);
1091 client_request_x11(const char *request_type, int rchan)
1095 int originator_port;
1098 if (!options.forward_x11) {
1099 error("Warning: ssh server tried X11 forwarding.");
1100 error("Warning: this is probably a break in attempt by a malicious server.");
1103 originator = packet_get_string(NULL);
1104 if (datafellows & SSH_BUG_X11FWD) {
1105 debug2("buggy server: x11 request w/o originator_port");
1106 originator_port = 0;
1108 originator_port = packet_get_int();
1111 /* XXX check permission */
1112 debug("client_request_x11: request from %s %d", originator,
1114 sock = x11_connect_display();
1116 newch = channel_new("x11",
1117 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1118 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1120 c = channel_lookup(newch);
1127 client_request_agent(const char *request_type, int rchan)
1132 if (!options.forward_agent) {
1133 error("Warning: ssh server tried agent forwarding.");
1134 error("Warning: this is probably a break in attempt by a malicious server.");
1137 sock = ssh_get_authentication_socket();
1139 newch = channel_new("authentication agent connection",
1140 SSH_CHANNEL_OPEN, sock, sock, -1,
1141 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1142 xstrdup("authentication agent connection"), 1);
1143 c = channel_lookup(newch);
1148 /* XXXX move to generic input handler */
1150 client_input_channel_open(int type, int plen, void *ctxt)
1159 ctype = packet_get_string(&len);
1160 rchan = packet_get_int();
1161 rwindow = packet_get_int();
1162 rmaxpack = packet_get_int();
1164 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1165 ctype, rchan, rwindow, rmaxpack);
1167 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1168 c = client_request_forwarded_tcpip(ctype, rchan);
1169 } else if (strcmp(ctype, "x11") == 0) {
1170 c = client_request_x11(ctype, rchan);
1171 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1172 c = client_request_agent(ctype, rchan);
1174 /* XXX duplicate : */
1176 debug("confirm %s", ctype);
1177 c->remote_id = rchan;
1178 c->remote_window = rwindow;
1179 c->remote_maxpacket = rmaxpack;
1181 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1182 packet_put_int(c->remote_id);
1183 packet_put_int(c->self);
1184 packet_put_int(c->local_window);
1185 packet_put_int(c->local_maxpacket);
1188 debug("failure %s", ctype);
1189 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1190 packet_put_int(rchan);
1191 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1192 packet_put_cstring("bla bla");
1193 packet_put_cstring("");
1199 client_input_channel_req(int type, int plen, void *ctxt)
1202 int id, reply, success = 0;
1205 id = packet_get_int();
1206 rtype = packet_get_string(NULL);
1207 reply = packet_get_char();
1209 debug("client_input_channel_req: channel %d rtype %s reply %d",
1212 if (session_ident == -1) {
1213 error("client_input_channel_req: no channel %d", session_ident);
1214 } else if (id != session_ident) {
1215 error("client_input_channel_req: channel %d: wrong channel: %d",
1218 c = channel_lookup(id);
1220 error("client_input_channel_req: channel %d: unknown channel", id);
1221 } else if (strcmp(rtype, "exit-status") == 0) {
1223 exit_status = packet_get_int();
1227 packet_start(success ?
1228 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1229 packet_put_int(c->remote_id);
1236 client_init_dispatch_20(void)
1238 dispatch_init(&dispatch_protocol_error);
1239 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1240 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1241 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1242 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1243 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1244 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1245 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1246 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1247 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1250 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1253 client_init_dispatch_13(void)
1255 dispatch_init(NULL);
1256 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1257 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1258 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1259 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1260 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1261 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1262 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1263 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1264 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1266 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1267 &auth_input_open_request : &deny_input_open);
1268 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1269 &x11_input_open : &deny_input_open);
1272 client_init_dispatch_15(void)
1274 client_init_dispatch_13();
1275 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1276 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1279 client_init_dispatch(void)
1282 client_init_dispatch_20();
1284 client_init_dispatch_13();
1286 client_init_dispatch_15();