a2d2d1d07465d91f92858dba93fe7038605d6a46
[dragonfly.git] / crypto / openssh / clientloop.c
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).
7  *
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".
13  *
14  *
15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
16  *
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.
25  *
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.
36  *
37  *
38  * SSH2 support added by Markus Friedl.
39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
40  *
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.
49  *
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.
60  */
61
62 #include "includes.h"
63
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>
74
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>
88
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"
112
113 /* import options */
114 extern Options options;
115
116 /* Flag indicating that stdin should be redirected from /dev/null. */
117 extern int stdin_null_flag;
118
119 /* Flag indicating that no shell has been requested */
120 extern int no_shell_flag;
121
122 /* Control socket */
123 extern int muxserver_sock;
124
125 /*
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.
129  */
130 extern char *host;
131
132 /*
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.
137  */
138 static volatile sig_atomic_t received_window_change_signal = 0;
139 static volatile sig_atomic_t received_signal = 0;
140
141 /* Flag indicating whether the user's terminal is in non-blocking mode. */
142 static int in_non_blocking_mode = 0;
143
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. */
159
160 static void client_init_dispatch(void);
161 int     session_ident = -1;
162
163 /* Track escape per proto2 channel */
164 struct escape_filter_ctx {
165         int escape_pending;
166         int escape_char;
167 };
168
169 /* Context for channel confirmation replies */
170 struct channel_reply_ctx {
171         const char *request_type;
172         int id, do_close;
173 };
174
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;
181 };
182 TAILQ_HEAD(global_confirms, global_confirm);
183 static struct global_confirms global_confirms =
184     TAILQ_HEAD_INITIALIZER(global_confirms);
185
186 /*XXX*/
187 extern Kex *xxx_kex;
188
189 void ssh_process_session2_setup(int, int, int, Buffer *);
190
191 /* Restores stdin to blocking mode. */
192
193 static void
194 leave_non_blocking(void)
195 {
196         if (in_non_blocking_mode) {
197                 unset_nonblock(fileno(stdin));
198                 in_non_blocking_mode = 0;
199         }
200 }
201
202 /* Puts stdin terminal in non-blocking mode. */
203
204 static void
205 enter_non_blocking(void)
206 {
207         in_non_blocking_mode = 1;
208         set_nonblock(fileno(stdin));
209 }
210
211 /*
212  * Signal handler for the window change signal (SIGWINCH).  This just sets a
213  * flag indicating that the window has changed.
214  */
215 /*ARGSUSED */
216 static void
217 window_change_handler(int sig)
218 {
219         received_window_change_signal = 1;
220         signal(SIGWINCH, window_change_handler);
221 }
222
223 /*
224  * Signal handler for signals that cause the program to terminate.  These
225  * signals must be trapped to restore terminal modes.
226  */
227 /*ARGSUSED */
228 static void
229 signal_handler(int sig)
230 {
231         received_signal = sig;
232         quit_pending = 1;
233 }
234
235 /*
236  * Returns current time in seconds from Jan 1, 1970 with the maximum
237  * available resolution.
238  */
239
240 static double
241 get_current_time(void)
242 {
243         struct timeval tv;
244         gettimeofday(&tv, NULL);
245         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
246 }
247
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)
252 {
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;
261
262         xauthdir = xauthfile = NULL;
263         *_proto = proto;
264         *_data = data;
265         proto[0] = data[0] = '\0';
266
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;
273                 }
274                 /*
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.
280                  */
281                 if (strncmp(display, "localhost:", 10) == 0) {
282                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
283                             display + 10);
284                         display = xdisplay;
285                 }
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;
301                         }
302                 }
303
304                 /*
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.
308                  */
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");
326         }
327
328         if (do_unlink) {
329                 unlink(xauthfile);
330                 rmdir(xauthdir);
331         }
332         if (xauthdir)
333                 xfree(xauthdir);
334         if (xauthfile)
335                 xfree(xauthfile);
336
337         /*
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.
344          */
345         if (!got_data) {
346                 u_int32_t rnd = 0;
347
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;
357                 }
358         }
359 }
360
361 /*
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.
365  */
366
367 static void
368 client_check_initial_eof_on_stdin(void)
369 {
370         int len;
371         char buf[1];
372
373         /*
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.
380          */
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();
389
390                 /* Check for immediate EOF on stdin. */
391                 len = read(fileno(stdin), buf, 1);
392                 if (len == 0) {
393                         /*
394                          * EOF.  Record that we have seen it and send
395                          * EOF to server.
396                          */
397                         debug("Sending eof.");
398                         stdin_eof = 1;
399                         packet_start(SSH_CMSG_EOF);
400                         packet_send();
401                 } else if (len > 0) {
402                         /*
403                          * Got data.  We must store the data in the buffer,
404                          * and also process it as an escape character if
405                          * appropriate.
406                          */
407                         if ((u_char) buf[0] == escape_char1)
408                                 escape_pending1 = 1;
409                         else
410                                 buffer_append(&stdin_buffer, buf, 1);
411                 }
412                 leave_non_blocking();
413         }
414 }
415
416
417 /*
418  * Make packets from buffered stdin data, and buffer them for sending to the
419  * connection.
420  */
421
422 static void
423 client_make_packets_from_stdin_data(void)
424 {
425         u_int len;
426
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();
442                 }
443         }
444 }
445
446 /*
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.
451  */
452
453 static void
454 client_check_window_change(void)
455 {
456         struct winsize ws;
457
458         if (! received_window_change_signal)
459                 return;
460         /** XXX race */
461         received_window_change_signal = 0;
462
463         debug2("client_check_window_change: changed");
464
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();
476         }
477 }
478
479 static void
480 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
481 {
482         struct global_confirm *gc;
483
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);
492         }
493
494         keep_alive_timeouts = 0;
495 }
496
497 static void
498 server_alive_check(void)
499 {
500         if (++keep_alive_timeouts > options.server_alive_count_max) {
501                 logit("Timeout, server not responding.");
502                 cleanup_exit(255);
503         }
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);
510 }
511
512 /*
513  * Waits until the client can do something (some data becomes available on
514  * one of the file descriptors).
515  */
516 static void
517 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
518     int *maxfdp, u_int *nallocp, int rekeying)
519 {
520         struct timeval tv, *tvp;
521         int ret;
522
523         /* Add any selections by the channel mechanism. */
524         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
525
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);
532                 /*
533                  * Read from stdin, unless we have seen EOF or have very much
534                  * buffered data to send to the server.
535                  */
536                 if (!stdin_eof && packet_not_very_much_data_to_write())
537                         FD_SET(fileno(stdin), *readsetp);
538
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);
554                 }
555         }
556
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);
560
561         if (muxserver_sock != -1)
562                 FD_SET(muxserver_sock, *readsetp);
563
564         /*
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.
568          */
569
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;
576         }
577         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
578         if (ret < 0) {
579                 char buf[100];
580
581                 /*
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.
585                  */
586                 memset(*readsetp, 0, *nallocp);
587                 memset(*writesetp, 0, *nallocp);
588
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();
597 }
598
599 static void
600 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
601 {
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));
609
610         leave_raw_mode();
611
612         /*
613          * Free (and clear) the buffer to reduce the amount of data that gets
614          * written to swap.
615          */
616         buffer_free(bin);
617         buffer_free(bout);
618         buffer_free(berr);
619
620         /* Send the suspend signal to the program itself. */
621         kill(getpid(), SIGTSTP);
622
623         /* Reset window sizes in case they have changed */
624         received_window_change_signal = 1;
625
626         /* OK, we have been continued by the user. Reinitialize buffers. */
627         buffer_init(bin);
628         buffer_init(bout);
629         buffer_init(berr);
630
631         enter_raw_mode();
632 }
633
634 static void
635 client_process_net_input(fd_set *readset)
636 {
637         int len;
638         char buf[8192];
639
640         /*
641          * Read input from the server, and add any such data to the buffer of
642          * the packet subsystem.
643          */
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) {
648                         /*
649                          * Received EOF.  The remote host has closed the
650                          * connection.
651                          */
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;
658                 }
659                 /*
660                  * There is a kernel bug on Solaris that causes select to
661                  * sometimes wake up even though there is no data available.
662                  */
663                 if (len < 0 &&
664                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
665                         len = 0;
666
667                 if (len < 0) {
668                         /*
669                          * An error has encountered.  Perhaps there is a
670                          * network problem.
671                          */
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;
678                 }
679                 packet_process_incoming(buf, len);
680         }
681 }
682
683 static void
684 client_status_confirm(int type, Channel *c, void *ctx)
685 {
686         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
687         char errmsg[256];
688         int tochan;
689
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;
693
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);
705                 }
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);
717                 }
718         }
719         xfree(cr);
720 }
721
722 static void
723 client_abandon_status_confirm(Channel *c, void *ctx)
724 {
725         xfree(ctx);
726 }
727
728 static void
729 client_expect_confirm(int id, const char *request, int do_close)
730 {
731         struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
732
733         cr->request_type = request;
734         cr->do_close = do_close;
735
736         channel_register_status_confirm(id, client_status_confirm,
737             client_abandon_status_confirm, cr);
738 }
739
740 void
741 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
742 {
743         struct global_confirm *gc, *last_gc;
744
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;
752         }
753
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);
759 }
760
761 static void
762 process_cmdline(void)
763 {
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;
770
771         bzero(&fwd, sizeof(fwd));
772         fwd.listen_host = fwd.connect_host = NULL;
773
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;
785
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;
801         }
802
803         if (*s == '!' && options.permit_local_command) {
804                 s++;
805                 ssh_local_cmd(s);
806                 goto out;
807         }
808
809         if (*s == 'K') {
810                 delete = 1;
811                 s++;
812         }
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;
822         }
823
824         if ((local || dynamic) && delete) {
825                 logit("Not supported.");
826                 goto out;
827         }
828         if (remote && delete && !compat20) {
829                 logit("Not supported for SSH protocol version 1.");
830                 goto out;
831         }
832
833         while (isspace(*++s))
834                 ;
835
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;
845                 }
846                 if (cancel_port <= 0) {
847                         logit("Bad forwarding close port");
848                         goto out;
849                 }
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;
855                 }
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;
862                         }
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;
869                         }
870                 }
871
872                 logit("Forwarding port.");
873         }
874
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);
884 }
885
886 /* 
887  * Process the characters one by one, call with c==NULL for proto1 case.
888  */
889 static int
890 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
891     char *buf, int len)
892 {
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;
901
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;
911         }
912         
913         if (len <= 0)
914                 return (0);
915
916         for (i = 0; i < (u_int)len; i++) {
917                 /* Get one character at a time. */
918                 ch = buf[i];
919
920                 if (*escape_pendingp) {
921                         /* We have previously seen an escape character. */
922                         /* Clear the flag now. */
923                         *escape_pendingp = 0;
924
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));
932
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;
940
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;
952                                 }
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));
957
958                                 /* Restore terminal modes and suspend. */
959                                 client_suspend_self(bin, bout, berr);
960
961                                 /* We have been continued. */
962                                 continue;
963
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();
974                                 }
975                                 continue;
976
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;
984                                 }
985                                 continue;
986
987                         case '&':
988                                 if (c && c->ctl_fd != -1)
989                                         goto noescape;
990                                 /*
991                                  * Detach the program (continue to serve
992                                  * connections, but put in background and no
993                                  * more new connections).
994                                  */
995                                 /* Restore tty modes. */
996                                 leave_raw_mode();
997
998                                 /* Stop listening for new connections. */
999                                 channel_stop_listening();
1000
1001                                 snprintf(string, sizeof string,
1002                                     "%c& [backgrounded]\n", escape_char);
1003                                 buffer_append(berr, string, strlen(string));
1004
1005                                 /* Fork into background. */
1006                                 pid = fork();
1007                                 if (pid < 0) {
1008                                         error("fork: %.100s", strerror(errno));
1009                                         continue;
1010                                 }
1011                                 if (pid != 0) { /* This is the parent. */
1012                                         /* The parent just exits. */
1013                                         exit(0);
1014                                 }
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) {
1021                                         /*
1022                                          * Sending SSH_CMSG_EOF alone does not
1023                                          * always appear to be enough.  So we
1024                                          * try to send an EOF character first.
1025                                          */
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();
1034                                         }
1035                                 }
1036                                 continue;
1037
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);
1074                                 }
1075                                 buffer_append(berr, string, strlen(string));
1076                                 continue;
1077
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;
1086
1087                         case 'C':
1088                                 if (c && c->ctl_fd != -1)
1089                                         goto noescape;
1090                                 process_cmdline();
1091                                 continue;
1092
1093                         default:
1094                                 if (ch != escape_char) {
1095                                         buffer_put_char(bin, escape_char);
1096                                         bytes++;
1097                                 }
1098                                 /* Escaped characters fall through here */
1099                                 break;
1100                         }
1101                 } else {
1102                         /*
1103                          * The previous character was not an escape char.
1104                          * Check if this is an escape.
1105                          */
1106                         if (last_was_cr && ch == escape_char) {
1107                                 /*
1108                                  * It is. Set the flag and continue to
1109                                  * next character.
1110                                  */
1111                                 *escape_pendingp = 1;
1112                                 continue;
1113                         }
1114                 }
1115
1116                 /*
1117                  * Normal character.  Record whether it was a newline,
1118                  * and append it to the buffer.
1119                  */
1120                 last_was_cr = (ch == '\r' || ch == '\n');
1121                 buffer_put_char(bin, ch);
1122                 bytes++;
1123         }
1124         return bytes;
1125 }
1126
1127 static void
1128 client_process_input(fd_set *readset)
1129 {
1130         int len;
1131         char buf[8192];
1132
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) {
1141                         /*
1142                          * Received EOF or error.  They are treated
1143                          * similarly, except that an error message is printed
1144                          * if it was an error condition.
1145                          */
1146                         if (len < 0) {
1147                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1148                                     strerror(errno));
1149                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1150                         }
1151                         /* Mark that we have seen EOF. */
1152                         stdin_eof = 1;
1153                         /*
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.
1159                          */
1160                         if (buffer_len(&stdin_buffer) == 0) {
1161                                 packet_start(SSH_CMSG_EOF);
1162                                 packet_send();
1163                         }
1164                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1165                         /*
1166                          * Normal successful read, and no escape character.
1167                          * Just append the data to buffer.
1168                          */
1169                         buffer_append(&stdin_buffer, buf, len);
1170                 } else {
1171                         /*
1172                          * Normal, successful read.  But we have an escape
1173                          * character and have to process the characters one
1174                          * by one.
1175                          */
1176                         if (process_escapes(NULL, &stdin_buffer,
1177                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1178                                 return;
1179                 }
1180         }
1181 }
1182
1183 static void
1184 client_process_output(fd_set *writeset)
1185 {
1186         int len;
1187         char buf[100];
1188
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 {
1199                                 /*
1200                                  * An error or EOF was encountered.  Put an
1201                                  * error message to stderr buffer.
1202                                  */
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;
1208                         }
1209                 }
1210                 /* Consume printed data from the buffer. */
1211                 buffer_consume(&stdout_buffer, len);
1212         }
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 {
1223                                 /*
1224                                  * EOF or error, but can't even print
1225                                  * error message.
1226                                  */
1227                                 quit_pending = 1;
1228                                 return;
1229                         }
1230                 }
1231                 /* Consume printed characters from the buffer. */
1232                 buffer_consume(&stderr_buffer, len);
1233         }
1234 }
1235
1236 /*
1237  * Get packets from the connection input buffer, and process them as long as
1238  * there are packets available.
1239  *
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.
1246  */
1247
1248 static void
1249 client_process_buffered_input_packets(void)
1250 {
1251         dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1252             compat20 ? xxx_kex : NULL);
1253 }
1254
1255 /* scan buf[] for '~' before sending data to the peer */
1256
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)
1260 {
1261         struct escape_filter_ctx *ret;
1262
1263         ret = xmalloc(sizeof(*ret));
1264         ret->escape_pending = 0;
1265         ret->escape_char = escape_char;
1266         return (void *)ret;
1267 }
1268
1269 /* Free the escape filter context on channel free */
1270 void
1271 client_filter_cleanup(int cid, void *ctx)
1272 {
1273         xfree(ctx);
1274 }
1275
1276 int
1277 client_simple_escape_filter(Channel *c, char *buf, int len)
1278 {
1279         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1280                 return 0;
1281
1282         return process_escapes(c, &c->input, &c->output, &c->extended,
1283             buf, len);
1284 }
1285
1286 static void
1287 client_channel_closed(int id, void *arg)
1288 {
1289         channel_cancel_cleanup(id);
1290         session_closed = 1;
1291         leave_raw_mode();
1292 }
1293
1294 /*
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.
1299  */
1300
1301 int
1302 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1303 {
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];
1310
1311         debug("Entering interactive session.");
1312
1313         start_time = get_current_time();
1314
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);
1326
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));
1338         }
1339         quit_pending = 0;
1340         escape_char1 = escape_char_arg;
1341
1342         /* Initialize buffers. */
1343         buffer_init(&stdin_buffer);
1344         buffer_init(&stdout_buffer);
1345         buffer_init(&stderr_buffer);
1346
1347         client_init_dispatch();
1348
1349         /*
1350          * Set signal handlers, (e.g. to restore non-blocking mode)
1351          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1352          */
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);
1362
1363         if (have_pty)
1364                 enter_raw_mode();
1365
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();
1379         }
1380
1381         /* Main loop of the client for the interactive session mode. */
1382         while (!quit_pending) {
1383
1384                 /* Process buffered packets sent by the server. */
1385                 client_process_buffered_input_packets();
1386
1387                 if (compat20 && session_closed && !channel_still_open())
1388                         break;
1389
1390                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1391
1392                 if (rekeying) {
1393                         debug("rekeying in progress");
1394                 } else {
1395                         /*
1396                          * Make packets of buffered stdin data, and buffer
1397                          * them for sending to the server.
1398                          */
1399                         if (!compat20)
1400                                 client_make_packets_from_stdin_data();
1401
1402                         /*
1403                          * Make packets from buffered channel data, and
1404                          * enqueue them for sending to the server.
1405                          */
1406                         if (packet_not_very_much_data_to_write())
1407                                 channel_output_poll();
1408
1409                         /*
1410                          * Check if the window size has changed, and buffer a
1411                          * message about it to the server if so.
1412                          */
1413                         client_check_window_change();
1414
1415                         if (quit_pending)
1416                                 break;
1417                 }
1418                 /*
1419                  * Wait until we have something to do (something becomes
1420                  * available on one of the descriptors).
1421                  */
1422                 max_fd2 = max_fd;
1423                 client_wait_until_can_do_something(&readset, &writeset,
1424                     &max_fd2, &nalloc, rekeying);
1425
1426                 if (quit_pending)
1427                         break;
1428
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;
1437                         }
1438                 }
1439
1440                 /* Buffer input from the connection.  */
1441                 client_process_net_input(readset);
1442
1443                 /* Accept control connections.  */
1444                 if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) {
1445                         if (muxserver_accept_control())
1446                                 quit_pending = 1;
1447                 }
1448
1449                 if (quit_pending)
1450                         break;
1451
1452                 if (!compat20) {
1453                         /* Buffer data from stdin */
1454                         client_process_input(readset);
1455                         /*
1456                          * Process output to stdout and stderr.  Output to
1457                          * the connection is processed elsewhere (above).
1458                          */
1459                         client_process_output(writeset);
1460                 }
1461
1462                 /*
1463                  * Send as much buffered packet data as possible to the
1464                  * sender.
1465                  */
1466                 if (FD_ISSET(connection_out, writeset))
1467                         packet_write_poll();
1468         }
1469         if (readset)
1470                 xfree(readset);
1471         if (writeset)
1472                 xfree(writeset);
1473
1474         /* Terminate the session. */
1475
1476         /* Stop watching for window change. */
1477         signal(SIGWINCH, SIG_DFL);
1478
1479         channel_free_all();
1480
1481         if (have_pty)
1482                 leave_raw_mode();
1483
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));
1491
1492         /*
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.
1496          */
1497         if (no_shell_flag && received_signal == SIGTERM) {
1498                 received_signal = 0;
1499                 exit_status = 0;
1500         }
1501
1502         if (received_signal)
1503                 fatal("Killed by signal %d.", (int) received_signal);
1504
1505         /*
1506          * In interactive mode (with pseudo tty) display a message indicating
1507          * that the connection has been closed.
1508          */
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));
1513         }
1514
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;
1522                 }
1523                 buffer_consume(&stdout_buffer, len);
1524         }
1525
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;
1533                 }
1534                 buffer_consume(&stderr_buffer, len);
1535         }
1536
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);
1542
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;
1555 }
1556
1557 /*********/
1558
1559 static void
1560 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1561 {
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);
1568 }
1569 static void
1570 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1571 {
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);
1578 }
1579 static void
1580 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1581 {
1582         exit_status = packet_get_int();
1583         packet_check_eom();
1584         /* Acknowledge the exit. */
1585         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1586         packet_send();
1587         /*
1588          * Must wait for packet to be sent since we are
1589          * exiting the loop.
1590          */
1591         packet_write_wait();
1592         /* Flag that we want to exit. */
1593         quit_pending = 1;
1594 }
1595 static void
1596 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1597 {
1598         Channel *c = NULL;
1599         int remote_id, sock;
1600
1601         /* Read the remote channel number from the message. */
1602         remote_id = packet_get_int();
1603         packet_check_eom();
1604
1605         /*
1606          * Get a connection to the local authentication agent (this may again
1607          * get forwarded).
1608          */
1609         sock = ssh_get_authentication_socket();
1610
1611         /*
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.
1616          */
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;
1622         }
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);
1632         }
1633         packet_send();
1634 }
1635
1636 static Channel *
1637 client_request_forwarded_tcpip(const char *request_type, int rchan)
1638 {
1639         Channel *c = NULL;
1640         char *listen_address, *originator_address;
1641         u_short listen_port, originator_port;
1642
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();
1649
1650         debug("client_request_forwarded_tcpip: listen %s port %d, "
1651             "originator %s port %d", listen_address, listen_port,
1652             originator_address, originator_port);
1653
1654         c = channel_connect_by_listen_address(listen_port,
1655             "forwarded-tcpip", originator_address);
1656
1657         xfree(originator_address);
1658         xfree(listen_address);
1659         return c;
1660 }
1661
1662 static Channel *
1663 client_request_x11(const char *request_type, int rchan)
1664 {
1665         Channel *c = NULL;
1666         char *originator;
1667         u_short originator_port;
1668         int sock;
1669
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;
1675         }
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();
1682         }
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;
1696 }
1697
1698 static Channel *
1699 client_request_agent(const char *request_type, int rchan)
1700 {
1701         Channel *c = NULL;
1702         int sock;
1703
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;
1709         }
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;
1719 }
1720
1721 int
1722 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1723 {
1724         Channel *c;
1725         int fd;
1726
1727         if (tun_mode == SSH_TUNMODE_NO)
1728                 return 0;
1729
1730         if (!compat20) {
1731                 error("Tunnel forwarding is not supported for protocol 1");
1732                 return -1;
1733         }
1734
1735         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1736
1737         /* Open local tunnel device */
1738         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1739                 error("Tunnel device open failed.");
1740                 return -1;
1741         }
1742
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;
1746
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
1752
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();
1761
1762         return 0;
1763 }
1764
1765 /* XXXX move to generic input handler */
1766 static void
1767 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1768 {
1769         Channel *c = NULL;
1770         char *ctype;
1771         int rchan;
1772         u_int rmaxpack, rwindow, len;
1773
1774         ctype = packet_get_string(&len);
1775         rchan = packet_get_int();
1776         rwindow = packet_get_int();
1777         rmaxpack = packet_get_int();
1778
1779         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1780             ctype, rchan, rwindow, rmaxpack);
1781
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);
1788         }
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();
1802                 }
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("");
1811                 }
1812                 packet_send();
1813         }
1814         xfree(ctype);
1815 }
1816 static void
1817 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1818 {
1819         Channel *c = NULL;
1820         int exitval, id, reply, success = 0;
1821         char *rtype;
1822
1823         id = packet_get_int();
1824         rtype = packet_get_string(NULL);
1825         reply = packet_get_char();
1826
1827         debug("client_input_channel_req: channel %d rtype %s reply %d",
1828             id, rtype, reply);
1829
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;
1849                 }
1850                 packet_check_eom();
1851         }
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();
1857         }
1858         xfree(rtype);
1859 }
1860 static void
1861 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1862 {
1863         char *rtype;
1864         int want_reply;
1865         int success = 0;
1866
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();
1876         }
1877         xfree(rtype);
1878 }
1879
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)
1883 {
1884         int len;
1885         Channel *c = NULL;
1886
1887         debug2("%s: id %d", __func__, id);
1888
1889         if ((c = channel_lookup(id)) == NULL)
1890                 fatal("client_session2_setup: channel %d: unknown channel", id);
1891
1892         if (want_tty) {
1893                 struct winsize ws;
1894
1895                 /* Store window size in the packet. */
1896                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1897                         memset(&ws, 0, sizeof(ws));
1898
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;
1912         }
1913
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;
1918
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;
1926                         }
1927                         *val++ = '\0';
1928
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;
1934                                 }
1935                         }
1936                         if (!matched) {
1937                                 debug3("Ignored env %s", name);
1938                                 xfree(name);
1939                                 continue;
1940                         }
1941
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);
1948                 }
1949         }
1950
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);
1965                 }
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();
1972         }
1973 }
1974
1975 static void
1976 client_init_dispatch_20(void)
1977 {
1978         dispatch_init(&dispatch_protocol_error);
1979
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);
1992
1993         /* rekeying */
1994         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1995
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);
1999 }
2000
2001 static void
2002 client_init_dispatch_13(void)
2003 {
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);
2014
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);
2019 }
2020
2021 static void
2022 client_init_dispatch_15(void)
2023 {
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);
2027 }
2028
2029 static void
2030 client_init_dispatch(void)
2031 {
2032         if (compat20)
2033                 client_init_dispatch_20();
2034         else if (compat13)
2035                 client_init_dispatch_13();
2036         else
2037                 client_init_dispatch_15();
2038 }
2039
2040 /* client specific fatal cleanup */
2041 void
2042 cleanup_exit(int i)
2043 {
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);
2049 }