pcm: perform stereo volume mixing for vchans
[dragonfly.git] / crypto / openssh / clientloop.c
bloba2d2d1d07465d91f92858dba93fe7038605d6a46
1 /* $OpenBSD: clientloop.c,v 1.209 2009/02/12 03:00:56 djm Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * The main loop for the interactive session (client side).
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
15 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 * SSH2 support added by Markus Friedl.
39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62 #include "includes.h"
64 #include <sys/types.h>
65 #include <sys/ioctl.h>
66 #include <sys/param.h>
67 #ifdef HAVE_SYS_STAT_H
68 # include <sys/stat.h>
69 #endif
70 #ifdef HAVE_SYS_TIME_H
71 # include <sys/time.h>
72 #endif
73 #include <sys/socket.h>
75 #include <ctype.h>
76 #include <errno.h>
77 #ifdef HAVE_PATHS_H
78 #include <paths.h>
79 #endif
80 #include <signal.h>
81 #include <stdarg.h>
82 #include <stdio.h>
83 #include <stdlib.h>
84 #include <string.h>
85 #include <termios.h>
86 #include <pwd.h>
87 #include <unistd.h>
89 #include "openbsd-compat/sys-queue.h"
90 #include "xmalloc.h"
91 #include "ssh.h"
92 #include "ssh1.h"
93 #include "ssh2.h"
94 #include "packet.h"
95 #include "buffer.h"
96 #include "compat.h"
97 #include "channels.h"
98 #include "dispatch.h"
99 #include "key.h"
100 #include "cipher.h"
101 #include "kex.h"
102 #include "log.h"
103 #include "readconf.h"
104 #include "clientloop.h"
105 #include "sshconnect.h"
106 #include "authfd.h"
107 #include "atomicio.h"
108 #include "sshpty.h"
109 #include "misc.h"
110 #include "match.h"
111 #include "msg.h"
113 /* import options */
114 extern Options options;
116 /* Flag indicating that stdin should be redirected from /dev/null. */
117 extern int stdin_null_flag;
119 /* Flag indicating that no shell has been requested */
120 extern int no_shell_flag;
122 /* Control socket */
123 extern int muxserver_sock;
126 * Name of the host we are connecting to. This is the name given on the
127 * command line, or the HostName specified for the user-supplied name in a
128 * configuration file.
130 extern char *host;
133 * Flag to indicate that we have received a window change signal which has
134 * not yet been processed. This will cause a message indicating the new
135 * window size to be sent to the server a little later. This is volatile
136 * because this is updated in a signal handler.
138 static volatile sig_atomic_t received_window_change_signal = 0;
139 static volatile sig_atomic_t received_signal = 0;
141 /* Flag indicating whether the user's terminal is in non-blocking mode. */
142 static int in_non_blocking_mode = 0;
144 /* Common data for the client loop code. */
145 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
146 static int escape_char1; /* Escape character. (proto1 only) */
147 static int escape_pending1; /* Last character was an escape (proto1 only) */
148 static int last_was_cr; /* Last character was a newline. */
149 static int exit_status; /* Used to store the command exit status. */
150 static int stdin_eof; /* EOF has been encountered on stderr. */
151 static Buffer stdin_buffer; /* Buffer for stdin data. */
152 static Buffer stdout_buffer; /* Buffer for stdout data. */
153 static Buffer stderr_buffer; /* Buffer for stderr data. */
154 static u_int buffer_high;/* Soft max buffer size. */
155 static int connection_in; /* Connection to server (input). */
156 static int connection_out; /* Connection to server (output). */
157 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
158 static int session_closed = 0; /* In SSH2: login session closed. */
160 static void client_init_dispatch(void);
161 int session_ident = -1;
163 /* Track escape per proto2 channel */
164 struct escape_filter_ctx {
165 int escape_pending;
166 int escape_char;
169 /* Context for channel confirmation replies */
170 struct channel_reply_ctx {
171 const char *request_type;
172 int id, do_close;
175 /* Global request success/failure callbacks */
176 struct global_confirm {
177 TAILQ_ENTRY(global_confirm) entry;
178 global_confirm_cb *cb;
179 void *ctx;
180 int ref_count;
182 TAILQ_HEAD(global_confirms, global_confirm);
183 static struct global_confirms global_confirms =
184 TAILQ_HEAD_INITIALIZER(global_confirms);
186 /*XXX*/
187 extern Kex *xxx_kex;
189 void ssh_process_session2_setup(int, int, int, Buffer *);
191 /* Restores stdin to blocking mode. */
193 static void
194 leave_non_blocking(void)
196 if (in_non_blocking_mode) {
197 unset_nonblock(fileno(stdin));
198 in_non_blocking_mode = 0;
202 /* Puts stdin terminal in non-blocking mode. */
204 static void
205 enter_non_blocking(void)
207 in_non_blocking_mode = 1;
208 set_nonblock(fileno(stdin));
212 * Signal handler for the window change signal (SIGWINCH). This just sets a
213 * flag indicating that the window has changed.
215 /*ARGSUSED */
216 static void
217 window_change_handler(int sig)
219 received_window_change_signal = 1;
220 signal(SIGWINCH, window_change_handler);
224 * Signal handler for signals that cause the program to terminate. These
225 * signals must be trapped to restore terminal modes.
227 /*ARGSUSED */
228 static void
229 signal_handler(int sig)
231 received_signal = sig;
232 quit_pending = 1;
236 * Returns current time in seconds from Jan 1, 1970 with the maximum
237 * available resolution.
240 static double
241 get_current_time(void)
243 struct timeval tv;
244 gettimeofday(&tv, NULL);
245 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
248 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
249 void
250 client_x11_get_proto(const char *display, const char *xauth_path,
251 u_int trusted, char **_proto, char **_data)
253 char cmd[1024];
254 char line[512];
255 char xdisplay[512];
256 static char proto[512], data[512];
257 FILE *f;
258 int got_data = 0, generated = 0, do_unlink = 0, i;
259 char *xauthdir, *xauthfile;
260 struct stat st;
262 xauthdir = xauthfile = NULL;
263 *_proto = proto;
264 *_data = data;
265 proto[0] = data[0] = '\0';
267 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
268 debug("No xauth program.");
269 } else {
270 if (display == NULL) {
271 debug("x11_get_proto: DISPLAY not set");
272 return;
275 * Handle FamilyLocal case where $DISPLAY does
276 * not match an authorization entry. For this we
277 * just try "xauth list unix:displaynum.screennum".
278 * XXX: "localhost" match to determine FamilyLocal
279 * is not perfect.
281 if (strncmp(display, "localhost:", 10) == 0) {
282 snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
283 display + 10);
284 display = xdisplay;
286 if (trusted == 0) {
287 xauthdir = xmalloc(MAXPATHLEN);
288 xauthfile = xmalloc(MAXPATHLEN);
289 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
290 if (mkdtemp(xauthdir) != NULL) {
291 do_unlink = 1;
292 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
293 xauthdir);
294 snprintf(cmd, sizeof(cmd),
295 "%s -f %s generate %s " SSH_X11_PROTO
296 " untrusted timeout 1200 2>" _PATH_DEVNULL,
297 xauth_path, xauthfile, display);
298 debug2("x11_get_proto: %s", cmd);
299 if (system(cmd) == 0)
300 generated = 1;
305 * When in untrusted mode, we read the cookie only if it was
306 * successfully generated as an untrusted one in the step
307 * above.
309 if (trusted || generated) {
310 snprintf(cmd, sizeof(cmd),
311 "%s %s%s list %s 2>" _PATH_DEVNULL,
312 xauth_path,
313 generated ? "-f " : "" ,
314 generated ? xauthfile : "",
315 display);
316 debug2("x11_get_proto: %s", cmd);
317 f = popen(cmd, "r");
318 if (f && fgets(line, sizeof(line), f) &&
319 sscanf(line, "%*s %511s %511s", proto, data) == 2)
320 got_data = 1;
321 if (f)
322 pclose(f);
323 } else
324 error("Warning: untrusted X11 forwarding setup failed: "
325 "xauth key data not generated");
328 if (do_unlink) {
329 unlink(xauthfile);
330 rmdir(xauthdir);
332 if (xauthdir)
333 xfree(xauthdir);
334 if (xauthfile)
335 xfree(xauthfile);
338 * If we didn't get authentication data, just make up some
339 * data. The forwarding code will check the validity of the
340 * response anyway, and substitute this data. The X11
341 * server, however, will ignore this fake data and use
342 * whatever authentication mechanisms it was using otherwise
343 * for the local connection.
345 if (!got_data) {
346 u_int32_t rnd = 0;
348 logit("Warning: No xauth data; "
349 "using fake authentication data for X11 forwarding.");
350 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
351 for (i = 0; i < 16; i++) {
352 if (i % 4 == 0)
353 rnd = arc4random();
354 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
355 rnd & 0xff);
356 rnd >>= 8;
362 * This is called when the interactive is entered. This checks if there is
363 * an EOF coming on stdin. We must check this explicitly, as select() does
364 * not appear to wake up when redirecting from /dev/null.
367 static void
368 client_check_initial_eof_on_stdin(void)
370 int len;
371 char buf[1];
374 * If standard input is to be "redirected from /dev/null", we simply
375 * mark that we have seen an EOF and send an EOF message to the
376 * server. Otherwise, we try to read a single character; it appears
377 * that for some files, such /dev/null, select() never wakes up for
378 * read for this descriptor, which means that we never get EOF. This
379 * way we will get the EOF if stdin comes from /dev/null or similar.
381 if (stdin_null_flag) {
382 /* Fake EOF on stdin. */
383 debug("Sending eof.");
384 stdin_eof = 1;
385 packet_start(SSH_CMSG_EOF);
386 packet_send();
387 } else {
388 enter_non_blocking();
390 /* Check for immediate EOF on stdin. */
391 len = read(fileno(stdin), buf, 1);
392 if (len == 0) {
394 * EOF. Record that we have seen it and send
395 * EOF to server.
397 debug("Sending eof.");
398 stdin_eof = 1;
399 packet_start(SSH_CMSG_EOF);
400 packet_send();
401 } else if (len > 0) {
403 * Got data. We must store the data in the buffer,
404 * and also process it as an escape character if
405 * appropriate.
407 if ((u_char) buf[0] == escape_char1)
408 escape_pending1 = 1;
409 else
410 buffer_append(&stdin_buffer, buf, 1);
412 leave_non_blocking();
418 * Make packets from buffered stdin data, and buffer them for sending to the
419 * connection.
422 static void
423 client_make_packets_from_stdin_data(void)
425 u_int len;
427 /* Send buffered stdin data to the server. */
428 while (buffer_len(&stdin_buffer) > 0 &&
429 packet_not_very_much_data_to_write()) {
430 len = buffer_len(&stdin_buffer);
431 /* Keep the packets at reasonable size. */
432 if (len > packet_get_maxsize())
433 len = packet_get_maxsize();
434 packet_start(SSH_CMSG_STDIN_DATA);
435 packet_put_string(buffer_ptr(&stdin_buffer), len);
436 packet_send();
437 buffer_consume(&stdin_buffer, len);
438 /* If we have a pending EOF, send it now. */
439 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
440 packet_start(SSH_CMSG_EOF);
441 packet_send();
447 * Checks if the client window has changed, and sends a packet about it to
448 * the server if so. The actual change is detected elsewhere (by a software
449 * interrupt on Unix); this just checks the flag and sends a message if
450 * appropriate.
453 static void
454 client_check_window_change(void)
456 struct winsize ws;
458 if (! received_window_change_signal)
459 return;
460 /** XXX race */
461 received_window_change_signal = 0;
463 debug2("client_check_window_change: changed");
465 if (compat20) {
466 channel_send_window_changes();
467 } else {
468 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
469 return;
470 packet_start(SSH_CMSG_WINDOW_SIZE);
471 packet_put_int((u_int)ws.ws_row);
472 packet_put_int((u_int)ws.ws_col);
473 packet_put_int((u_int)ws.ws_xpixel);
474 packet_put_int((u_int)ws.ws_ypixel);
475 packet_send();
479 static void
480 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
482 struct global_confirm *gc;
484 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
485 return;
486 if (gc->cb != NULL)
487 gc->cb(type, seq, gc->ctx);
488 if (--gc->ref_count <= 0) {
489 TAILQ_REMOVE(&global_confirms, gc, entry);
490 bzero(gc, sizeof(*gc));
491 xfree(gc);
494 keep_alive_timeouts = 0;
497 static void
498 server_alive_check(void)
500 if (++keep_alive_timeouts > options.server_alive_count_max) {
501 logit("Timeout, server not responding.");
502 cleanup_exit(255);
504 packet_start(SSH2_MSG_GLOBAL_REQUEST);
505 packet_put_cstring("keepalive@openssh.com");
506 packet_put_char(1); /* boolean: want reply */
507 packet_send();
508 /* Insert an empty placeholder to maintain ordering */
509 client_register_global_confirm(NULL, NULL);
513 * Waits until the client can do something (some data becomes available on
514 * one of the file descriptors).
516 static void
517 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
518 int *maxfdp, u_int *nallocp, int rekeying)
520 struct timeval tv, *tvp;
521 int ret;
523 /* Add any selections by the channel mechanism. */
524 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
526 if (!compat20) {
527 /* Read from the connection, unless our buffers are full. */
528 if (buffer_len(&stdout_buffer) < buffer_high &&
529 buffer_len(&stderr_buffer) < buffer_high &&
530 channel_not_very_much_buffered_data())
531 FD_SET(connection_in, *readsetp);
533 * Read from stdin, unless we have seen EOF or have very much
534 * buffered data to send to the server.
536 if (!stdin_eof && packet_not_very_much_data_to_write())
537 FD_SET(fileno(stdin), *readsetp);
539 /* Select stdout/stderr if have data in buffer. */
540 if (buffer_len(&stdout_buffer) > 0)
541 FD_SET(fileno(stdout), *writesetp);
542 if (buffer_len(&stderr_buffer) > 0)
543 FD_SET(fileno(stderr), *writesetp);
544 } else {
545 /* channel_prepare_select could have closed the last channel */
546 if (session_closed && !channel_still_open() &&
547 !packet_have_data_to_write()) {
548 /* clear mask since we did not call select() */
549 memset(*readsetp, 0, *nallocp);
550 memset(*writesetp, 0, *nallocp);
551 return;
552 } else {
553 FD_SET(connection_in, *readsetp);
557 /* Select server connection if have data to write to the server. */
558 if (packet_have_data_to_write())
559 FD_SET(connection_out, *writesetp);
561 if (muxserver_sock != -1)
562 FD_SET(muxserver_sock, *readsetp);
565 * Wait for something to happen. This will suspend the process until
566 * some selected descriptor can be read, written, or has some other
567 * event pending.
570 if (options.server_alive_interval == 0 || !compat20)
571 tvp = NULL;
572 else {
573 tv.tv_sec = options.server_alive_interval;
574 tv.tv_usec = 0;
575 tvp = &tv;
577 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
578 if (ret < 0) {
579 char buf[100];
582 * We have to clear the select masks, because we return.
583 * We have to return, because the mainloop checks for the flags
584 * set by the signal handlers.
586 memset(*readsetp, 0, *nallocp);
587 memset(*writesetp, 0, *nallocp);
589 if (errno == EINTR)
590 return;
591 /* Note: we might still have data in the buffers. */
592 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
593 buffer_append(&stderr_buffer, buf, strlen(buf));
594 quit_pending = 1;
595 } else if (ret == 0)
596 server_alive_check();
599 static void
600 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
602 /* Flush stdout and stderr buffers. */
603 if (buffer_len(bout) > 0)
604 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
605 buffer_len(bout));
606 if (buffer_len(berr) > 0)
607 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
608 buffer_len(berr));
610 leave_raw_mode();
613 * Free (and clear) the buffer to reduce the amount of data that gets
614 * written to swap.
616 buffer_free(bin);
617 buffer_free(bout);
618 buffer_free(berr);
620 /* Send the suspend signal to the program itself. */
621 kill(getpid(), SIGTSTP);
623 /* Reset window sizes in case they have changed */
624 received_window_change_signal = 1;
626 /* OK, we have been continued by the user. Reinitialize buffers. */
627 buffer_init(bin);
628 buffer_init(bout);
629 buffer_init(berr);
631 enter_raw_mode();
634 static void
635 client_process_net_input(fd_set *readset)
637 int len;
638 char buf[8192];
641 * Read input from the server, and add any such data to the buffer of
642 * the packet subsystem.
644 if (FD_ISSET(connection_in, readset)) {
645 /* Read as much as possible. */
646 len = read(connection_in, buf, sizeof(buf));
647 if (len == 0) {
649 * Received EOF. The remote host has closed the
650 * connection.
652 snprintf(buf, sizeof buf,
653 "Connection to %.300s closed by remote host.\r\n",
654 host);
655 buffer_append(&stderr_buffer, buf, strlen(buf));
656 quit_pending = 1;
657 return;
660 * There is a kernel bug on Solaris that causes select to
661 * sometimes wake up even though there is no data available.
663 if (len < 0 &&
664 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
665 len = 0;
667 if (len < 0) {
669 * An error has encountered. Perhaps there is a
670 * network problem.
672 snprintf(buf, sizeof buf,
673 "Read from remote host %.300s: %.100s\r\n",
674 host, strerror(errno));
675 buffer_append(&stderr_buffer, buf, strlen(buf));
676 quit_pending = 1;
677 return;
679 packet_process_incoming(buf, len);
683 static void
684 client_status_confirm(int type, Channel *c, void *ctx)
686 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
687 char errmsg[256];
688 int tochan;
690 /* XXX supress on mux _client_ quietmode */
691 tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
692 c->ctl_fd != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
694 if (type == SSH2_MSG_CHANNEL_SUCCESS) {
695 debug2("%s request accepted on channel %d",
696 cr->request_type, c->self);
697 } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
698 if (tochan) {
699 snprintf(errmsg, sizeof(errmsg),
700 "%s request failed\r\n", cr->request_type);
701 } else {
702 snprintf(errmsg, sizeof(errmsg),
703 "%s request failed on channel %d",
704 cr->request_type, c->self);
706 /* If error occurred on primary session channel, then exit */
707 if (cr->do_close && c->self == session_ident)
708 fatal("%s", errmsg);
709 /* If error occurred on mux client, append to their stderr */
710 if (tochan)
711 buffer_append(&c->extended, errmsg, strlen(errmsg));
712 else
713 error("%s", errmsg);
714 if (cr->do_close) {
715 chan_read_failed(c);
716 chan_write_failed(c);
719 xfree(cr);
722 static void
723 client_abandon_status_confirm(Channel *c, void *ctx)
725 xfree(ctx);
728 static void
729 client_expect_confirm(int id, const char *request, int do_close)
731 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
733 cr->request_type = request;
734 cr->do_close = do_close;
736 channel_register_status_confirm(id, client_status_confirm,
737 client_abandon_status_confirm, cr);
740 void
741 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
743 struct global_confirm *gc, *last_gc;
745 /* Coalesce identical callbacks */
746 last_gc = TAILQ_LAST(&global_confirms, global_confirms);
747 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
748 if (++last_gc->ref_count >= INT_MAX)
749 fatal("%s: last_gc->ref_count = %d",
750 __func__, last_gc->ref_count);
751 return;
754 gc = xmalloc(sizeof(*gc));
755 gc->cb = cb;
756 gc->ctx = ctx;
757 gc->ref_count = 1;
758 TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
761 static void
762 process_cmdline(void)
764 void (*handler)(int);
765 char *s, *cmd, *cancel_host;
766 int delete = 0;
767 int local = 0, remote = 0, dynamic = 0;
768 int cancel_port;
769 Forward fwd;
771 bzero(&fwd, sizeof(fwd));
772 fwd.listen_host = fwd.connect_host = NULL;
774 leave_raw_mode();
775 handler = signal(SIGINT, SIG_IGN);
776 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
777 if (s == NULL)
778 goto out;
779 while (isspace(*s))
780 s++;
781 if (*s == '-')
782 s++; /* Skip cmdline '-', if any */
783 if (*s == '\0')
784 goto out;
786 if (*s == 'h' || *s == 'H' || *s == '?') {
787 logit("Commands:");
788 logit(" -L[bind_address:]port:host:hostport "
789 "Request local forward");
790 logit(" -R[bind_address:]port:host:hostport "
791 "Request remote forward");
792 logit(" -D[bind_address:]port "
793 "Request dynamic forward");
794 logit(" -KR[bind_address:]port "
795 "Cancel remote forward");
796 if (!options.permit_local_command)
797 goto out;
798 logit(" !args "
799 "Execute local command");
800 goto out;
803 if (*s == '!' && options.permit_local_command) {
804 s++;
805 ssh_local_cmd(s);
806 goto out;
809 if (*s == 'K') {
810 delete = 1;
811 s++;
813 if (*s == 'L')
814 local = 1;
815 else if (*s == 'R')
816 remote = 1;
817 else if (*s == 'D')
818 dynamic = 1;
819 else {
820 logit("Invalid command.");
821 goto out;
824 if ((local || dynamic) && delete) {
825 logit("Not supported.");
826 goto out;
828 if (remote && delete && !compat20) {
829 logit("Not supported for SSH protocol version 1.");
830 goto out;
833 while (isspace(*++s))
836 if (delete) {
837 cancel_port = 0;
838 cancel_host = hpdelim(&s); /* may be NULL */
839 if (s != NULL) {
840 cancel_port = a2port(s);
841 cancel_host = cleanhostname(cancel_host);
842 } else {
843 cancel_port = a2port(cancel_host);
844 cancel_host = NULL;
846 if (cancel_port <= 0) {
847 logit("Bad forwarding close port");
848 goto out;
850 channel_request_rforward_cancel(cancel_host, cancel_port);
851 } else {
852 if (!parse_forward(&fwd, s, dynamic, remote)) {
853 logit("Bad forwarding specification.");
854 goto out;
856 if (local || dynamic) {
857 if (channel_setup_local_fwd_listener(fwd.listen_host,
858 fwd.listen_port, fwd.connect_host,
859 fwd.connect_port, options.gateway_ports) < 0) {
860 logit("Port forwarding failed.");
861 goto out;
863 } else {
864 if (channel_request_remote_forwarding(fwd.listen_host,
865 fwd.listen_port, fwd.connect_host,
866 fwd.connect_port) < 0) {
867 logit("Port forwarding failed.");
868 goto out;
872 logit("Forwarding port.");
875 out:
876 signal(SIGINT, handler);
877 enter_raw_mode();
878 if (cmd)
879 xfree(cmd);
880 if (fwd.listen_host != NULL)
881 xfree(fwd.listen_host);
882 if (fwd.connect_host != NULL)
883 xfree(fwd.connect_host);
887 * Process the characters one by one, call with c==NULL for proto1 case.
889 static int
890 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
891 char *buf, int len)
893 char string[1024];
894 pid_t pid;
895 int bytes = 0;
896 u_int i;
897 u_char ch;
898 char *s;
899 int *escape_pendingp, escape_char;
900 struct escape_filter_ctx *efc;
902 if (c == NULL) {
903 escape_pendingp = &escape_pending1;
904 escape_char = escape_char1;
905 } else {
906 if (c->filter_ctx == NULL)
907 return 0;
908 efc = (struct escape_filter_ctx *)c->filter_ctx;
909 escape_pendingp = &efc->escape_pending;
910 escape_char = efc->escape_char;
913 if (len <= 0)
914 return (0);
916 for (i = 0; i < (u_int)len; i++) {
917 /* Get one character at a time. */
918 ch = buf[i];
920 if (*escape_pendingp) {
921 /* We have previously seen an escape character. */
922 /* Clear the flag now. */
923 *escape_pendingp = 0;
925 /* Process the escaped character. */
926 switch (ch) {
927 case '.':
928 /* Terminate the connection. */
929 snprintf(string, sizeof string, "%c.\r\n",
930 escape_char);
931 buffer_append(berr, string, strlen(string));
933 if (c && c->ctl_fd != -1) {
934 chan_read_failed(c);
935 chan_write_failed(c);
936 return 0;
937 } else
938 quit_pending = 1;
939 return -1;
941 case 'Z' - 64:
942 /* XXX support this for mux clients */
943 if (c && c->ctl_fd != -1) {
944 noescape:
945 snprintf(string, sizeof string,
946 "%c%c escape not available to "
947 "multiplexed sessions\r\n",
948 escape_char, ch);
949 buffer_append(berr, string,
950 strlen(string));
951 continue;
953 /* Suspend the program. Inform the user */
954 snprintf(string, sizeof string,
955 "%c^Z [suspend ssh]\r\n", escape_char);
956 buffer_append(berr, string, strlen(string));
958 /* Restore terminal modes and suspend. */
959 client_suspend_self(bin, bout, berr);
961 /* We have been continued. */
962 continue;
964 case 'B':
965 if (compat20) {
966 snprintf(string, sizeof string,
967 "%cB\r\n", escape_char);
968 buffer_append(berr, string,
969 strlen(string));
970 channel_request_start(session_ident,
971 "break", 0);
972 packet_put_int(1000);
973 packet_send();
975 continue;
977 case 'R':
978 if (compat20) {
979 if (datafellows & SSH_BUG_NOREKEY)
980 logit("Server does not "
981 "support re-keying");
982 else
983 need_rekeying = 1;
985 continue;
987 case '&':
988 if (c && c->ctl_fd != -1)
989 goto noescape;
991 * Detach the program (continue to serve
992 * connections, but put in background and no
993 * more new connections).
995 /* Restore tty modes. */
996 leave_raw_mode();
998 /* Stop listening for new connections. */
999 channel_stop_listening();
1001 snprintf(string, sizeof string,
1002 "%c& [backgrounded]\n", escape_char);
1003 buffer_append(berr, string, strlen(string));
1005 /* Fork into background. */
1006 pid = fork();
1007 if (pid < 0) {
1008 error("fork: %.100s", strerror(errno));
1009 continue;
1011 if (pid != 0) { /* This is the parent. */
1012 /* The parent just exits. */
1013 exit(0);
1015 /* The child continues serving connections. */
1016 if (compat20) {
1017 buffer_append(bin, "\004", 1);
1018 /* fake EOF on stdin */
1019 return -1;
1020 } else if (!stdin_eof) {
1022 * Sending SSH_CMSG_EOF alone does not
1023 * always appear to be enough. So we
1024 * try to send an EOF character first.
1026 packet_start(SSH_CMSG_STDIN_DATA);
1027 packet_put_string("\004", 1);
1028 packet_send();
1029 /* Close stdin. */
1030 stdin_eof = 1;
1031 if (buffer_len(bin) == 0) {
1032 packet_start(SSH_CMSG_EOF);
1033 packet_send();
1036 continue;
1038 case '?':
1039 if (c && c->ctl_fd != -1) {
1040 snprintf(string, sizeof string,
1041 "%c?\r\n\
1042 Supported escape sequences:\r\n\
1043 %c. - terminate session\r\n\
1044 %cB - send a BREAK to the remote system\r\n\
1045 %cR - Request rekey (SSH protocol 2 only)\r\n\
1046 %c# - list forwarded connections\r\n\
1047 %c? - this message\r\n\
1048 %c%c - send the escape character by typing it twice\r\n\
1049 (Note that escapes are only recognized immediately after newline.)\r\n",
1050 escape_char, escape_char,
1051 escape_char, escape_char,
1052 escape_char, escape_char,
1053 escape_char, escape_char);
1054 } else {
1055 snprintf(string, sizeof string,
1056 "%c?\r\n\
1057 Supported escape sequences:\r\n\
1058 %c. - terminate connection (and any multiplexed sessions)\r\n\
1059 %cB - send a BREAK to the remote system\r\n\
1060 %cC - open a command line\r\n\
1061 %cR - Request rekey (SSH protocol 2 only)\r\n\
1062 %c^Z - suspend ssh\r\n\
1063 %c# - list forwarded connections\r\n\
1064 %c& - background ssh (when waiting for connections to terminate)\r\n\
1065 %c? - this message\r\n\
1066 %c%c - send the escape character by typing it twice\r\n\
1067 (Note that escapes are only recognized immediately after newline.)\r\n",
1068 escape_char, escape_char,
1069 escape_char, escape_char,
1070 escape_char, escape_char,
1071 escape_char, escape_char,
1072 escape_char, escape_char,
1073 escape_char);
1075 buffer_append(berr, string, strlen(string));
1076 continue;
1078 case '#':
1079 snprintf(string, sizeof string, "%c#\r\n",
1080 escape_char);
1081 buffer_append(berr, string, strlen(string));
1082 s = channel_open_message();
1083 buffer_append(berr, s, strlen(s));
1084 xfree(s);
1085 continue;
1087 case 'C':
1088 if (c && c->ctl_fd != -1)
1089 goto noescape;
1090 process_cmdline();
1091 continue;
1093 default:
1094 if (ch != escape_char) {
1095 buffer_put_char(bin, escape_char);
1096 bytes++;
1098 /* Escaped characters fall through here */
1099 break;
1101 } else {
1103 * The previous character was not an escape char.
1104 * Check if this is an escape.
1106 if (last_was_cr && ch == escape_char) {
1108 * It is. Set the flag and continue to
1109 * next character.
1111 *escape_pendingp = 1;
1112 continue;
1117 * Normal character. Record whether it was a newline,
1118 * and append it to the buffer.
1120 last_was_cr = (ch == '\r' || ch == '\n');
1121 buffer_put_char(bin, ch);
1122 bytes++;
1124 return bytes;
1127 static void
1128 client_process_input(fd_set *readset)
1130 int len;
1131 char buf[8192];
1133 /* Read input from stdin. */
1134 if (FD_ISSET(fileno(stdin), readset)) {
1135 /* Read as much as possible. */
1136 len = read(fileno(stdin), buf, sizeof(buf));
1137 if (len < 0 &&
1138 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1139 return; /* we'll try again later */
1140 if (len <= 0) {
1142 * Received EOF or error. They are treated
1143 * similarly, except that an error message is printed
1144 * if it was an error condition.
1146 if (len < 0) {
1147 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1148 strerror(errno));
1149 buffer_append(&stderr_buffer, buf, strlen(buf));
1151 /* Mark that we have seen EOF. */
1152 stdin_eof = 1;
1154 * Send an EOF message to the server unless there is
1155 * data in the buffer. If there is data in the
1156 * buffer, no message will be sent now. Code
1157 * elsewhere will send the EOF when the buffer
1158 * becomes empty if stdin_eof is set.
1160 if (buffer_len(&stdin_buffer) == 0) {
1161 packet_start(SSH_CMSG_EOF);
1162 packet_send();
1164 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1166 * Normal successful read, and no escape character.
1167 * Just append the data to buffer.
1169 buffer_append(&stdin_buffer, buf, len);
1170 } else {
1172 * Normal, successful read. But we have an escape
1173 * character and have to process the characters one
1174 * by one.
1176 if (process_escapes(NULL, &stdin_buffer,
1177 &stdout_buffer, &stderr_buffer, buf, len) == -1)
1178 return;
1183 static void
1184 client_process_output(fd_set *writeset)
1186 int len;
1187 char buf[100];
1189 /* Write buffered output to stdout. */
1190 if (FD_ISSET(fileno(stdout), writeset)) {
1191 /* Write as much data as possible. */
1192 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1193 buffer_len(&stdout_buffer));
1194 if (len <= 0) {
1195 if (errno == EINTR || errno == EAGAIN ||
1196 errno == EWOULDBLOCK)
1197 len = 0;
1198 else {
1200 * An error or EOF was encountered. Put an
1201 * error message to stderr buffer.
1203 snprintf(buf, sizeof buf,
1204 "write stdout: %.50s\r\n", strerror(errno));
1205 buffer_append(&stderr_buffer, buf, strlen(buf));
1206 quit_pending = 1;
1207 return;
1210 /* Consume printed data from the buffer. */
1211 buffer_consume(&stdout_buffer, len);
1213 /* Write buffered output to stderr. */
1214 if (FD_ISSET(fileno(stderr), writeset)) {
1215 /* Write as much data as possible. */
1216 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1217 buffer_len(&stderr_buffer));
1218 if (len <= 0) {
1219 if (errno == EINTR || errno == EAGAIN ||
1220 errno == EWOULDBLOCK)
1221 len = 0;
1222 else {
1224 * EOF or error, but can't even print
1225 * error message.
1227 quit_pending = 1;
1228 return;
1231 /* Consume printed characters from the buffer. */
1232 buffer_consume(&stderr_buffer, len);
1237 * Get packets from the connection input buffer, and process them as long as
1238 * there are packets available.
1240 * Any unknown packets received during the actual
1241 * session cause the session to terminate. This is
1242 * intended to make debugging easier since no
1243 * confirmations are sent. Any compatible protocol
1244 * extensions must be negotiated during the
1245 * preparatory phase.
1248 static void
1249 client_process_buffered_input_packets(void)
1251 dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1252 compat20 ? xxx_kex : NULL);
1255 /* scan buf[] for '~' before sending data to the peer */
1257 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1258 void *
1259 client_new_escape_filter_ctx(int escape_char)
1261 struct escape_filter_ctx *ret;
1263 ret = xmalloc(sizeof(*ret));
1264 ret->escape_pending = 0;
1265 ret->escape_char = escape_char;
1266 return (void *)ret;
1269 /* Free the escape filter context on channel free */
1270 void
1271 client_filter_cleanup(int cid, void *ctx)
1273 xfree(ctx);
1277 client_simple_escape_filter(Channel *c, char *buf, int len)
1279 if (c->extended_usage != CHAN_EXTENDED_WRITE)
1280 return 0;
1282 return process_escapes(c, &c->input, &c->output, &c->extended,
1283 buf, len);
1286 static void
1287 client_channel_closed(int id, void *arg)
1289 channel_cancel_cleanup(id);
1290 session_closed = 1;
1291 leave_raw_mode();
1295 * Implements the interactive session with the server. This is called after
1296 * the user has been authenticated, and a command has been started on the
1297 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1298 * used as an escape character for terminating or suspending the session.
1302 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1304 fd_set *readset = NULL, *writeset = NULL;
1305 double start_time, total_time;
1306 int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1307 u_int64_t ibytes, obytes;
1308 u_int nalloc = 0;
1309 char buf[100];
1311 debug("Entering interactive session.");
1313 start_time = get_current_time();
1315 /* Initialize variables. */
1316 escape_pending1 = 0;
1317 last_was_cr = 1;
1318 exit_status = -1;
1319 stdin_eof = 0;
1320 buffer_high = 64 * 1024;
1321 connection_in = packet_get_connection_in();
1322 connection_out = packet_get_connection_out();
1323 max_fd = MAX(connection_in, connection_out);
1324 if (muxserver_sock != -1)
1325 max_fd = MAX(max_fd, muxserver_sock);
1327 if (!compat20) {
1328 /* enable nonblocking unless tty */
1329 if (!isatty(fileno(stdin)))
1330 set_nonblock(fileno(stdin));
1331 if (!isatty(fileno(stdout)))
1332 set_nonblock(fileno(stdout));
1333 if (!isatty(fileno(stderr)))
1334 set_nonblock(fileno(stderr));
1335 max_fd = MAX(max_fd, fileno(stdin));
1336 max_fd = MAX(max_fd, fileno(stdout));
1337 max_fd = MAX(max_fd, fileno(stderr));
1339 quit_pending = 0;
1340 escape_char1 = escape_char_arg;
1342 /* Initialize buffers. */
1343 buffer_init(&stdin_buffer);
1344 buffer_init(&stdout_buffer);
1345 buffer_init(&stderr_buffer);
1347 client_init_dispatch();
1350 * Set signal handlers, (e.g. to restore non-blocking mode)
1351 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1353 if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1354 signal(SIGHUP, signal_handler);
1355 if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1356 signal(SIGINT, signal_handler);
1357 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1358 signal(SIGQUIT, signal_handler);
1359 if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1360 signal(SIGTERM, signal_handler);
1361 signal(SIGWINCH, window_change_handler);
1363 if (have_pty)
1364 enter_raw_mode();
1366 if (compat20) {
1367 session_ident = ssh2_chan_id;
1368 if (escape_char_arg != SSH_ESCAPECHAR_NONE)
1369 channel_register_filter(session_ident,
1370 client_simple_escape_filter, NULL,
1371 client_filter_cleanup,
1372 client_new_escape_filter_ctx(escape_char_arg));
1373 if (session_ident != -1)
1374 channel_register_cleanup(session_ident,
1375 client_channel_closed, 0);
1376 } else {
1377 /* Check if we should immediately send eof on stdin. */
1378 client_check_initial_eof_on_stdin();
1381 /* Main loop of the client for the interactive session mode. */
1382 while (!quit_pending) {
1384 /* Process buffered packets sent by the server. */
1385 client_process_buffered_input_packets();
1387 if (compat20 && session_closed && !channel_still_open())
1388 break;
1390 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1392 if (rekeying) {
1393 debug("rekeying in progress");
1394 } else {
1396 * Make packets of buffered stdin data, and buffer
1397 * them for sending to the server.
1399 if (!compat20)
1400 client_make_packets_from_stdin_data();
1403 * Make packets from buffered channel data, and
1404 * enqueue them for sending to the server.
1406 if (packet_not_very_much_data_to_write())
1407 channel_output_poll();
1410 * Check if the window size has changed, and buffer a
1411 * message about it to the server if so.
1413 client_check_window_change();
1415 if (quit_pending)
1416 break;
1419 * Wait until we have something to do (something becomes
1420 * available on one of the descriptors).
1422 max_fd2 = max_fd;
1423 client_wait_until_can_do_something(&readset, &writeset,
1424 &max_fd2, &nalloc, rekeying);
1426 if (quit_pending)
1427 break;
1429 /* Do channel operations unless rekeying in progress. */
1430 if (!rekeying) {
1431 channel_after_select(readset, writeset);
1432 if (need_rekeying || packet_need_rekeying()) {
1433 debug("need rekeying");
1434 xxx_kex->done = 0;
1435 kex_send_kexinit(xxx_kex);
1436 need_rekeying = 0;
1440 /* Buffer input from the connection. */
1441 client_process_net_input(readset);
1443 /* Accept control connections. */
1444 if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) {
1445 if (muxserver_accept_control())
1446 quit_pending = 1;
1449 if (quit_pending)
1450 break;
1452 if (!compat20) {
1453 /* Buffer data from stdin */
1454 client_process_input(readset);
1456 * Process output to stdout and stderr. Output to
1457 * the connection is processed elsewhere (above).
1459 client_process_output(writeset);
1463 * Send as much buffered packet data as possible to the
1464 * sender.
1466 if (FD_ISSET(connection_out, writeset))
1467 packet_write_poll();
1469 if (readset)
1470 xfree(readset);
1471 if (writeset)
1472 xfree(writeset);
1474 /* Terminate the session. */
1476 /* Stop watching for window change. */
1477 signal(SIGWINCH, SIG_DFL);
1479 channel_free_all();
1481 if (have_pty)
1482 leave_raw_mode();
1484 /* restore blocking io */
1485 if (!isatty(fileno(stdin)))
1486 unset_nonblock(fileno(stdin));
1487 if (!isatty(fileno(stdout)))
1488 unset_nonblock(fileno(stdout));
1489 if (!isatty(fileno(stderr)))
1490 unset_nonblock(fileno(stderr));
1493 * If there was no shell or command requested, there will be no remote
1494 * exit status to be returned. In that case, clear error code if the
1495 * connection was deliberately terminated at this end.
1497 if (no_shell_flag && received_signal == SIGTERM) {
1498 received_signal = 0;
1499 exit_status = 0;
1502 if (received_signal)
1503 fatal("Killed by signal %d.", (int) received_signal);
1506 * In interactive mode (with pseudo tty) display a message indicating
1507 * that the connection has been closed.
1509 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1510 snprintf(buf, sizeof buf,
1511 "Connection to %.64s closed.\r\n", host);
1512 buffer_append(&stderr_buffer, buf, strlen(buf));
1515 /* Output any buffered data for stdout. */
1516 while (buffer_len(&stdout_buffer) > 0) {
1517 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1518 buffer_len(&stdout_buffer));
1519 if (len <= 0) {
1520 error("Write failed flushing stdout buffer.");
1521 break;
1523 buffer_consume(&stdout_buffer, len);
1526 /* Output any buffered data for stderr. */
1527 while (buffer_len(&stderr_buffer) > 0) {
1528 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1529 buffer_len(&stderr_buffer));
1530 if (len <= 0) {
1531 error("Write failed flushing stderr buffer.");
1532 break;
1534 buffer_consume(&stderr_buffer, len);
1537 /* Clear and free any buffers. */
1538 memset(buf, 0, sizeof(buf));
1539 buffer_free(&stdin_buffer);
1540 buffer_free(&stdout_buffer);
1541 buffer_free(&stderr_buffer);
1543 /* Report bytes transferred, and transfer rates. */
1544 total_time = get_current_time() - start_time;
1545 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1546 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1547 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1548 obytes, ibytes, total_time);
1549 if (total_time > 0)
1550 verbose("Bytes per second: sent %.1f, received %.1f",
1551 obytes / total_time, ibytes / total_time);
1552 /* Return the exit status of the program. */
1553 debug("Exit status %d", exit_status);
1554 return exit_status;
1557 /*********/
1559 static void
1560 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1562 u_int data_len;
1563 char *data = packet_get_string(&data_len);
1564 packet_check_eom();
1565 buffer_append(&stdout_buffer, data, data_len);
1566 memset(data, 0, data_len);
1567 xfree(data);
1569 static void
1570 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1572 u_int data_len;
1573 char *data = packet_get_string(&data_len);
1574 packet_check_eom();
1575 buffer_append(&stderr_buffer, data, data_len);
1576 memset(data, 0, data_len);
1577 xfree(data);
1579 static void
1580 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1582 exit_status = packet_get_int();
1583 packet_check_eom();
1584 /* Acknowledge the exit. */
1585 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1586 packet_send();
1588 * Must wait for packet to be sent since we are
1589 * exiting the loop.
1591 packet_write_wait();
1592 /* Flag that we want to exit. */
1593 quit_pending = 1;
1595 static void
1596 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1598 Channel *c = NULL;
1599 int remote_id, sock;
1601 /* Read the remote channel number from the message. */
1602 remote_id = packet_get_int();
1603 packet_check_eom();
1606 * Get a connection to the local authentication agent (this may again
1607 * get forwarded).
1609 sock = ssh_get_authentication_socket();
1612 * If we could not connect the agent, send an error message back to
1613 * the server. This should never happen unless the agent dies,
1614 * because authentication forwarding is only enabled if we have an
1615 * agent.
1617 if (sock >= 0) {
1618 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1619 -1, 0, 0, 0, "authentication agent connection", 1);
1620 c->remote_id = remote_id;
1621 c->force_drain = 1;
1623 if (c == NULL) {
1624 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1625 packet_put_int(remote_id);
1626 } else {
1627 /* Send a confirmation to the remote host. */
1628 debug("Forwarding authentication connection.");
1629 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1630 packet_put_int(remote_id);
1631 packet_put_int(c->self);
1633 packet_send();
1636 static Channel *
1637 client_request_forwarded_tcpip(const char *request_type, int rchan)
1639 Channel *c = NULL;
1640 char *listen_address, *originator_address;
1641 u_short listen_port, originator_port;
1643 /* Get rest of the packet */
1644 listen_address = packet_get_string(NULL);
1645 listen_port = packet_get_int();
1646 originator_address = packet_get_string(NULL);
1647 originator_port = packet_get_int();
1648 packet_check_eom();
1650 debug("client_request_forwarded_tcpip: listen %s port %d, "
1651 "originator %s port %d", listen_address, listen_port,
1652 originator_address, originator_port);
1654 c = channel_connect_by_listen_address(listen_port,
1655 "forwarded-tcpip", originator_address);
1657 xfree(originator_address);
1658 xfree(listen_address);
1659 return c;
1662 static Channel *
1663 client_request_x11(const char *request_type, int rchan)
1665 Channel *c = NULL;
1666 char *originator;
1667 u_short originator_port;
1668 int sock;
1670 if (!options.forward_x11) {
1671 error("Warning: ssh server tried X11 forwarding.");
1672 error("Warning: this is probably a break-in attempt by a "
1673 "malicious server.");
1674 return NULL;
1676 originator = packet_get_string(NULL);
1677 if (datafellows & SSH_BUG_X11FWD) {
1678 debug2("buggy server: x11 request w/o originator_port");
1679 originator_port = 0;
1680 } else {
1681 originator_port = packet_get_int();
1683 packet_check_eom();
1684 /* XXX check permission */
1685 debug("client_request_x11: request from %s %d", originator,
1686 originator_port);
1687 xfree(originator);
1688 sock = x11_connect_display();
1689 if (sock < 0)
1690 return NULL;
1691 c = channel_new("x11",
1692 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1693 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1694 c->force_drain = 1;
1695 return c;
1698 static Channel *
1699 client_request_agent(const char *request_type, int rchan)
1701 Channel *c = NULL;
1702 int sock;
1704 if (!options.forward_agent) {
1705 error("Warning: ssh server tried agent forwarding.");
1706 error("Warning: this is probably a break-in attempt by a "
1707 "malicious server.");
1708 return NULL;
1710 sock = ssh_get_authentication_socket();
1711 if (sock < 0)
1712 return NULL;
1713 c = channel_new("authentication agent connection",
1714 SSH_CHANNEL_OPEN, sock, sock, -1,
1715 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1716 "authentication agent connection", 1);
1717 c->force_drain = 1;
1718 return c;
1722 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1724 Channel *c;
1725 int fd;
1727 if (tun_mode == SSH_TUNMODE_NO)
1728 return 0;
1730 if (!compat20) {
1731 error("Tunnel forwarding is not supported for protocol 1");
1732 return -1;
1735 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1737 /* Open local tunnel device */
1738 if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1739 error("Tunnel device open failed.");
1740 return -1;
1743 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1744 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1745 c->datagram = 1;
1747 #if defined(SSH_TUN_FILTER)
1748 if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1749 channel_register_filter(c->self, sys_tun_infilter,
1750 sys_tun_outfilter, NULL, NULL);
1751 #endif
1753 packet_start(SSH2_MSG_CHANNEL_OPEN);
1754 packet_put_cstring("tun@openssh.com");
1755 packet_put_int(c->self);
1756 packet_put_int(c->local_window_max);
1757 packet_put_int(c->local_maxpacket);
1758 packet_put_int(tun_mode);
1759 packet_put_int(remote_tun);
1760 packet_send();
1762 return 0;
1765 /* XXXX move to generic input handler */
1766 static void
1767 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1769 Channel *c = NULL;
1770 char *ctype;
1771 int rchan;
1772 u_int rmaxpack, rwindow, len;
1774 ctype = packet_get_string(&len);
1775 rchan = packet_get_int();
1776 rwindow = packet_get_int();
1777 rmaxpack = packet_get_int();
1779 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1780 ctype, rchan, rwindow, rmaxpack);
1782 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1783 c = client_request_forwarded_tcpip(ctype, rchan);
1784 } else if (strcmp(ctype, "x11") == 0) {
1785 c = client_request_x11(ctype, rchan);
1786 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1787 c = client_request_agent(ctype, rchan);
1789 /* XXX duplicate : */
1790 if (c != NULL) {
1791 debug("confirm %s", ctype);
1792 c->remote_id = rchan;
1793 c->remote_window = rwindow;
1794 c->remote_maxpacket = rmaxpack;
1795 if (c->type != SSH_CHANNEL_CONNECTING) {
1796 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1797 packet_put_int(c->remote_id);
1798 packet_put_int(c->self);
1799 packet_put_int(c->local_window);
1800 packet_put_int(c->local_maxpacket);
1801 packet_send();
1803 } else {
1804 debug("failure %s", ctype);
1805 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1806 packet_put_int(rchan);
1807 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1808 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1809 packet_put_cstring("open failed");
1810 packet_put_cstring("");
1812 packet_send();
1814 xfree(ctype);
1816 static void
1817 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1819 Channel *c = NULL;
1820 int exitval, id, reply, success = 0;
1821 char *rtype;
1823 id = packet_get_int();
1824 rtype = packet_get_string(NULL);
1825 reply = packet_get_char();
1827 debug("client_input_channel_req: channel %d rtype %s reply %d",
1828 id, rtype, reply);
1830 if (id == -1) {
1831 error("client_input_channel_req: request for channel -1");
1832 } else if ((c = channel_lookup(id)) == NULL) {
1833 error("client_input_channel_req: channel %d: "
1834 "unknown channel", id);
1835 } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1836 packet_check_eom();
1837 chan_rcvd_eow(c);
1838 } else if (strcmp(rtype, "exit-status") == 0) {
1839 exitval = packet_get_int();
1840 if (id == session_ident) {
1841 success = 1;
1842 exit_status = exitval;
1843 } else if (c->ctl_fd == -1) {
1844 error("client_input_channel_req: unexpected channel %d",
1845 session_ident);
1846 } else {
1847 atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1848 success = 1;
1850 packet_check_eom();
1852 if (reply) {
1853 packet_start(success ?
1854 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1855 packet_put_int(c->remote_id);
1856 packet_send();
1858 xfree(rtype);
1860 static void
1861 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1863 char *rtype;
1864 int want_reply;
1865 int success = 0;
1867 rtype = packet_get_string(NULL);
1868 want_reply = packet_get_char();
1869 debug("client_input_global_request: rtype %s want_reply %d",
1870 rtype, want_reply);
1871 if (want_reply) {
1872 packet_start(success ?
1873 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1874 packet_send();
1875 packet_write_wait();
1877 xfree(rtype);
1880 void
1881 client_session2_setup(int id, int want_tty, int want_subsystem,
1882 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
1884 int len;
1885 Channel *c = NULL;
1887 debug2("%s: id %d", __func__, id);
1889 if ((c = channel_lookup(id)) == NULL)
1890 fatal("client_session2_setup: channel %d: unknown channel", id);
1892 if (want_tty) {
1893 struct winsize ws;
1895 /* Store window size in the packet. */
1896 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1897 memset(&ws, 0, sizeof(ws));
1899 channel_request_start(id, "pty-req", 1);
1900 client_expect_confirm(id, "PTY allocation", 0);
1901 packet_put_cstring(term != NULL ? term : "");
1902 packet_put_int((u_int)ws.ws_col);
1903 packet_put_int((u_int)ws.ws_row);
1904 packet_put_int((u_int)ws.ws_xpixel);
1905 packet_put_int((u_int)ws.ws_ypixel);
1906 if (tiop == NULL)
1907 tiop = get_saved_tio();
1908 tty_make_modes(-1, tiop);
1909 packet_send();
1910 /* XXX wait for reply */
1911 c->client_tty = 1;
1914 /* Transfer any environment variables from client to server */
1915 if (options.num_send_env != 0 && env != NULL) {
1916 int i, j, matched;
1917 char *name, *val;
1919 debug("Sending environment.");
1920 for (i = 0; env[i] != NULL; i++) {
1921 /* Split */
1922 name = xstrdup(env[i]);
1923 if ((val = strchr(name, '=')) == NULL) {
1924 xfree(name);
1925 continue;
1927 *val++ = '\0';
1929 matched = 0;
1930 for (j = 0; j < options.num_send_env; j++) {
1931 if (match_pattern(name, options.send_env[j])) {
1932 matched = 1;
1933 break;
1936 if (!matched) {
1937 debug3("Ignored env %s", name);
1938 xfree(name);
1939 continue;
1942 debug("Sending env %s = %s", name, val);
1943 channel_request_start(id, "env", 0);
1944 packet_put_cstring(name);
1945 packet_put_cstring(val);
1946 packet_send();
1947 xfree(name);
1951 len = buffer_len(cmd);
1952 if (len > 0) {
1953 if (len > 900)
1954 len = 900;
1955 if (want_subsystem) {
1956 debug("Sending subsystem: %.*s",
1957 len, (u_char*)buffer_ptr(cmd));
1958 channel_request_start(id, "subsystem", 1);
1959 client_expect_confirm(id, "subsystem", 1);
1960 } else {
1961 debug("Sending command: %.*s",
1962 len, (u_char*)buffer_ptr(cmd));
1963 channel_request_start(id, "exec", 1);
1964 client_expect_confirm(id, "exec", 1);
1966 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1967 packet_send();
1968 } else {
1969 channel_request_start(id, "shell", 1);
1970 client_expect_confirm(id, "shell", 1);
1971 packet_send();
1975 static void
1976 client_init_dispatch_20(void)
1978 dispatch_init(&dispatch_protocol_error);
1980 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1981 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1982 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1983 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1984 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1985 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1986 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1987 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1988 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1989 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
1990 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
1991 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1993 /* rekeying */
1994 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1996 /* global request reply messages */
1997 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1998 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2001 static void
2002 client_init_dispatch_13(void)
2004 dispatch_init(NULL);
2005 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2006 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2007 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2008 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2009 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2010 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2011 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2012 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2013 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2015 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2016 &client_input_agent_open : &deny_input_open);
2017 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2018 &x11_input_open : &deny_input_open);
2021 static void
2022 client_init_dispatch_15(void)
2024 client_init_dispatch_13();
2025 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2026 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2029 static void
2030 client_init_dispatch(void)
2032 if (compat20)
2033 client_init_dispatch_20();
2034 else if (compat13)
2035 client_init_dispatch_13();
2036 else
2037 client_init_dispatch_15();
2040 /* client specific fatal cleanup */
2041 void
2042 cleanup_exit(int i)
2044 leave_raw_mode();
2045 leave_non_blocking();
2046 if (options.control_path != NULL && muxserver_sock != -1)
2047 unlink(options.control_path);
2048 _exit(i);