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1 | /* | |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * The main loop for the interactive session (client side). | |
6 | * | |
7 | * As far as I am concerned, the code I have written for this software | |
8 | * can be used freely for any purpose. Any derived versions of this | |
9 | * software must be clearly marked as such, and if the derived work is | |
10 | * incompatible with the protocol description in the RFC file, it must be | |
11 | * called by a name other than "ssh" or "Secure Shell". | |
12 | * | |
13 | * | |
14 | * Copyright (c) 1999 Theo de Raadt. All rights reserved. | |
15 | * | |
16 | * Redistribution and use in source and binary forms, with or without | |
17 | * modification, are permitted provided that the following conditions | |
18 | * are met: | |
19 | * 1. Redistributions of source code must retain the above copyright | |
20 | * notice, this list of conditions and the following disclaimer. | |
21 | * 2. Redistributions in binary form must reproduce the above copyright | |
22 | * notice, this list of conditions and the following disclaimer in the | |
23 | * documentation and/or other materials provided with the distribution. | |
24 | * | |
25 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
26 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
27 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
28 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
29 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
30 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
31 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
32 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
33 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
34 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
35 | * | |
36 | * | |
37 | * SSH2 support added by Markus Friedl. | |
38 | * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. | |
39 | * | |
40 | * Redistribution and use in source and binary forms, with or without | |
41 | * modification, are permitted provided that the following conditions | |
42 | * are met: | |
43 | * 1. Redistributions of source code must retain the above copyright | |
44 | * notice, this list of conditions and the following disclaimer. | |
45 | * 2. Redistributions in binary form must reproduce the above copyright | |
46 | * notice, this list of conditions and the following disclaimer in the | |
47 | * documentation and/or other materials provided with the distribution. | |
48 | * | |
49 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
50 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
51 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
52 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
53 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
54 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
55 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
56 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
57 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
58 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
59 | */ | |
60 | ||
61 | #include "includes.h" | |
62 | RCSID("$OpenBSD: clientloop.c,v 1.119 2004/05/08 00:21:31 djm Exp $"); | |
63 | ||
64 | #include "ssh.h" | |
65 | #include "ssh1.h" | |
66 | #include "ssh2.h" | |
67 | #include "xmalloc.h" | |
68 | #include "packet.h" | |
69 | #include "buffer.h" | |
70 | #include "compat.h" | |
71 | #include "channels.h" | |
72 | #include "dispatch.h" | |
73 | #include "buffer.h" | |
74 | #include "bufaux.h" | |
75 | #include "key.h" | |
76 | #include "kex.h" | |
77 | #include "log.h" | |
78 | #include "readconf.h" | |
79 | #include "clientloop.h" | |
80 | #include "authfd.h" | |
81 | #include "atomicio.h" | |
82 | #include "sshpty.h" | |
83 | #include "misc.h" | |
84 | ||
85 | /* import options */ | |
86 | extern Options options; | |
87 | ||
88 | /* Flag indicating that stdin should be redirected from /dev/null. */ | |
89 | extern int stdin_null_flag; | |
90 | ||
91 | /* Flag indicating that no shell has been requested */ | |
92 | extern int no_shell_flag; | |
93 | ||
94 | /* | |
95 | * Name of the host we are connecting to. This is the name given on the | |
96 | * command line, or the HostName specified for the user-supplied name in a | |
97 | * configuration file. | |
98 | */ | |
99 | extern char *host; | |
100 | ||
101 | /* | |
102 | * Flag to indicate that we have received a window change signal which has | |
103 | * not yet been processed. This will cause a message indicating the new | |
104 | * window size to be sent to the server a little later. This is volatile | |
105 | * because this is updated in a signal handler. | |
106 | */ | |
107 | static volatile sig_atomic_t received_window_change_signal = 0; | |
108 | static volatile sig_atomic_t received_signal = 0; | |
109 | ||
110 | /* Flag indicating whether the user\'s terminal is in non-blocking mode. */ | |
111 | static int in_non_blocking_mode = 0; | |
112 | ||
113 | /* Common data for the client loop code. */ | |
114 | static int quit_pending; /* Set to non-zero to quit the client loop. */ | |
115 | static int escape_char; /* Escape character. */ | |
116 | static int escape_pending; /* Last character was the escape character */ | |
117 | static int last_was_cr; /* Last character was a newline. */ | |
118 | static int exit_status; /* Used to store the exit status of the command. */ | |
119 | static int stdin_eof; /* EOF has been encountered on standard error. */ | |
120 | static Buffer stdin_buffer; /* Buffer for stdin data. */ | |
121 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
122 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
123 | static u_long stdin_bytes, stdout_bytes, stderr_bytes; | |
124 | static u_int buffer_high;/* Soft max buffer size. */ | |
125 | static int connection_in; /* Connection to server (input). */ | |
126 | static int connection_out; /* Connection to server (output). */ | |
127 | static int need_rekeying; /* Set to non-zero if rekeying is requested. */ | |
128 | static int session_closed = 0; /* In SSH2: login session closed. */ | |
129 | static int server_alive_timeouts = 0; | |
130 | ||
131 | static void client_init_dispatch(void); | |
132 | int session_ident = -1; | |
133 | ||
134 | /*XXX*/ | |
135 | extern Kex *xxx_kex; | |
136 | ||
137 | /* Restores stdin to blocking mode. */ | |
138 | ||
139 | static void | |
140 | leave_non_blocking(void) | |
141 | { | |
142 | if (in_non_blocking_mode) { | |
143 | (void) fcntl(fileno(stdin), F_SETFL, 0); | |
144 | in_non_blocking_mode = 0; | |
145 | } | |
146 | } | |
147 | ||
148 | /* Puts stdin terminal in non-blocking mode. */ | |
149 | ||
150 | static void | |
151 | enter_non_blocking(void) | |
152 | { | |
153 | in_non_blocking_mode = 1; | |
154 | (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK); | |
155 | } | |
156 | ||
157 | /* | |
158 | * Signal handler for the window change signal (SIGWINCH). This just sets a | |
159 | * flag indicating that the window has changed. | |
160 | */ | |
161 | ||
162 | static void | |
163 | window_change_handler(int sig) | |
164 | { | |
165 | received_window_change_signal = 1; | |
166 | signal(SIGWINCH, window_change_handler); | |
167 | } | |
168 | ||
169 | /* | |
170 | * Signal handler for signals that cause the program to terminate. These | |
171 | * signals must be trapped to restore terminal modes. | |
172 | */ | |
173 | ||
174 | static void | |
175 | signal_handler(int sig) | |
176 | { | |
177 | received_signal = sig; | |
178 | quit_pending = 1; | |
179 | } | |
180 | ||
181 | /* | |
182 | * Returns current time in seconds from Jan 1, 1970 with the maximum | |
183 | * available resolution. | |
184 | */ | |
185 | ||
186 | static double | |
187 | get_current_time(void) | |
188 | { | |
189 | struct timeval tv; | |
190 | gettimeofday(&tv, NULL); | |
191 | return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * This is called when the interactive is entered. This checks if there is | |
196 | * an EOF coming on stdin. We must check this explicitly, as select() does | |
197 | * not appear to wake up when redirecting from /dev/null. | |
198 | */ | |
199 | ||
200 | static void | |
201 | client_check_initial_eof_on_stdin(void) | |
202 | { | |
203 | int len; | |
204 | char buf[1]; | |
205 | ||
206 | /* | |
207 | * If standard input is to be "redirected from /dev/null", we simply | |
208 | * mark that we have seen an EOF and send an EOF message to the | |
209 | * server. Otherwise, we try to read a single character; it appears | |
210 | * that for some files, such /dev/null, select() never wakes up for | |
211 | * read for this descriptor, which means that we never get EOF. This | |
212 | * way we will get the EOF if stdin comes from /dev/null or similar. | |
213 | */ | |
214 | if (stdin_null_flag) { | |
215 | /* Fake EOF on stdin. */ | |
216 | debug("Sending eof."); | |
217 | stdin_eof = 1; | |
218 | packet_start(SSH_CMSG_EOF); | |
219 | packet_send(); | |
220 | } else { | |
221 | enter_non_blocking(); | |
222 | ||
223 | /* Check for immediate EOF on stdin. */ | |
224 | len = read(fileno(stdin), buf, 1); | |
225 | if (len == 0) { | |
226 | /* EOF. Record that we have seen it and send EOF to server. */ | |
227 | debug("Sending eof."); | |
228 | stdin_eof = 1; | |
229 | packet_start(SSH_CMSG_EOF); | |
230 | packet_send(); | |
231 | } else if (len > 0) { | |
232 | /* | |
233 | * Got data. We must store the data in the buffer, | |
234 | * and also process it as an escape character if | |
235 | * appropriate. | |
236 | */ | |
237 | if ((u_char) buf[0] == escape_char) | |
238 | escape_pending = 1; | |
239 | else | |
240 | buffer_append(&stdin_buffer, buf, 1); | |
241 | } | |
242 | leave_non_blocking(); | |
243 | } | |
244 | } | |
245 | ||
246 | ||
247 | /* | |
248 | * Make packets from buffered stdin data, and buffer them for sending to the | |
249 | * connection. | |
250 | */ | |
251 | ||
252 | static void | |
253 | client_make_packets_from_stdin_data(void) | |
254 | { | |
255 | u_int len; | |
256 | ||
257 | /* Send buffered stdin data to the server. */ | |
258 | while (buffer_len(&stdin_buffer) > 0 && | |
259 | packet_not_very_much_data_to_write()) { | |
260 | len = buffer_len(&stdin_buffer); | |
261 | /* Keep the packets at reasonable size. */ | |
262 | if (len > packet_get_maxsize()) | |
263 | len = packet_get_maxsize(); | |
264 | packet_start(SSH_CMSG_STDIN_DATA); | |
265 | packet_put_string(buffer_ptr(&stdin_buffer), len); | |
266 | packet_send(); | |
267 | buffer_consume(&stdin_buffer, len); | |
268 | stdin_bytes += len; | |
269 | /* If we have a pending EOF, send it now. */ | |
270 | if (stdin_eof && buffer_len(&stdin_buffer) == 0) { | |
271 | packet_start(SSH_CMSG_EOF); | |
272 | packet_send(); | |
273 | } | |
274 | } | |
275 | } | |
276 | ||
277 | /* | |
278 | * Checks if the client window has changed, and sends a packet about it to | |
279 | * the server if so. The actual change is detected elsewhere (by a software | |
280 | * interrupt on Unix); this just checks the flag and sends a message if | |
281 | * appropriate. | |
282 | */ | |
283 | ||
284 | static void | |
285 | client_check_window_change(void) | |
286 | { | |
287 | struct winsize ws; | |
288 | ||
289 | if (! received_window_change_signal) | |
290 | return; | |
291 | /** XXX race */ | |
292 | received_window_change_signal = 0; | |
293 | ||
294 | if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) | |
295 | return; | |
296 | ||
297 | debug2("client_check_window_change: changed"); | |
298 | ||
299 | if (compat20) { | |
300 | channel_request_start(session_ident, "window-change", 0); | |
301 | packet_put_int(ws.ws_col); | |
302 | packet_put_int(ws.ws_row); | |
303 | packet_put_int(ws.ws_xpixel); | |
304 | packet_put_int(ws.ws_ypixel); | |
305 | packet_send(); | |
306 | } else { | |
307 | packet_start(SSH_CMSG_WINDOW_SIZE); | |
308 | packet_put_int(ws.ws_row); | |
309 | packet_put_int(ws.ws_col); | |
310 | packet_put_int(ws.ws_xpixel); | |
311 | packet_put_int(ws.ws_ypixel); | |
312 | packet_send(); | |
313 | } | |
314 | } | |
315 | ||
316 | static void | |
317 | client_global_request_reply(int type, u_int32_t seq, void *ctxt) | |
318 | { | |
319 | server_alive_timeouts = 0; | |
320 | client_global_request_reply_fwd(type, seq, ctxt); | |
321 | } | |
322 | ||
323 | static void | |
324 | server_alive_check(void) | |
325 | { | |
326 | if (++server_alive_timeouts > options.server_alive_count_max) | |
327 | packet_disconnect("Timeout, server not responding."); | |
328 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
329 | packet_put_cstring("keepalive@openssh.com"); | |
330 | packet_put_char(1); /* boolean: want reply */ | |
331 | packet_send(); | |
332 | } | |
333 | ||
334 | /* | |
335 | * Waits until the client can do something (some data becomes available on | |
336 | * one of the file descriptors). | |
337 | */ | |
338 | ||
339 | static void | |
340 | client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, | |
341 | int *maxfdp, int *nallocp, int rekeying) | |
342 | { | |
343 | struct timeval tv, *tvp; | |
344 | int ret; | |
345 | ||
346 | /* Add any selections by the channel mechanism. */ | |
347 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); | |
348 | ||
349 | if (!compat20) { | |
350 | /* Read from the connection, unless our buffers are full. */ | |
351 | if (buffer_len(&stdout_buffer) < buffer_high && | |
352 | buffer_len(&stderr_buffer) < buffer_high && | |
353 | channel_not_very_much_buffered_data()) | |
354 | FD_SET(connection_in, *readsetp); | |
355 | /* | |
356 | * Read from stdin, unless we have seen EOF or have very much | |
357 | * buffered data to send to the server. | |
358 | */ | |
359 | if (!stdin_eof && packet_not_very_much_data_to_write()) | |
360 | FD_SET(fileno(stdin), *readsetp); | |
361 | ||
362 | /* Select stdout/stderr if have data in buffer. */ | |
363 | if (buffer_len(&stdout_buffer) > 0) | |
364 | FD_SET(fileno(stdout), *writesetp); | |
365 | if (buffer_len(&stderr_buffer) > 0) | |
366 | FD_SET(fileno(stderr), *writesetp); | |
367 | } else { | |
368 | /* channel_prepare_select could have closed the last channel */ | |
369 | if (session_closed && !channel_still_open() && | |
370 | !packet_have_data_to_write()) { | |
371 | /* clear mask since we did not call select() */ | |
372 | memset(*readsetp, 0, *nallocp); | |
373 | memset(*writesetp, 0, *nallocp); | |
374 | return; | |
375 | } else { | |
376 | FD_SET(connection_in, *readsetp); | |
377 | } | |
378 | } | |
379 | ||
380 | /* Select server connection if have data to write to the server. */ | |
381 | if (packet_have_data_to_write()) | |
382 | FD_SET(connection_out, *writesetp); | |
383 | ||
384 | /* | |
385 | * Wait for something to happen. This will suspend the process until | |
386 | * some selected descriptor can be read, written, or has some other | |
387 | * event pending. | |
388 | */ | |
389 | ||
390 | if (options.server_alive_interval == 0 || !compat20) | |
391 | tvp = NULL; | |
392 | else { | |
393 | tv.tv_sec = options.server_alive_interval; | |
394 | tv.tv_usec = 0; | |
395 | tvp = &tv; | |
396 | } | |
397 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); | |
398 | if (ret < 0) { | |
399 | char buf[100]; | |
400 | ||
401 | /* | |
402 | * We have to clear the select masks, because we return. | |
403 | * We have to return, because the mainloop checks for the flags | |
404 | * set by the signal handlers. | |
405 | */ | |
406 | memset(*readsetp, 0, *nallocp); | |
407 | memset(*writesetp, 0, *nallocp); | |
408 | ||
409 | if (errno == EINTR) | |
410 | return; | |
411 | /* Note: we might still have data in the buffers. */ | |
412 | snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); | |
413 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
414 | quit_pending = 1; | |
415 | } else if (ret == 0) | |
416 | server_alive_check(); | |
417 | } | |
418 | ||
419 | static void | |
420 | client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) | |
421 | { | |
422 | struct winsize oldws, newws; | |
423 | ||
424 | /* Flush stdout and stderr buffers. */ | |
425 | if (buffer_len(bout) > 0) | |
426 | atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout)); | |
427 | if (buffer_len(berr) > 0) | |
428 | atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr)); | |
429 | ||
430 | leave_raw_mode(); | |
431 | ||
432 | /* | |
433 | * Free (and clear) the buffer to reduce the amount of data that gets | |
434 | * written to swap. | |
435 | */ | |
436 | buffer_free(bin); | |
437 | buffer_free(bout); | |
438 | buffer_free(berr); | |
439 | ||
440 | /* Save old window size. */ | |
441 | ioctl(fileno(stdin), TIOCGWINSZ, &oldws); | |
442 | ||
443 | /* Send the suspend signal to the program itself. */ | |
444 | kill(getpid(), SIGTSTP); | |
445 | ||
446 | /* Check if the window size has changed. */ | |
447 | if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 && | |
448 | (oldws.ws_row != newws.ws_row || | |
449 | oldws.ws_col != newws.ws_col || | |
450 | oldws.ws_xpixel != newws.ws_xpixel || | |
451 | oldws.ws_ypixel != newws.ws_ypixel)) | |
452 | received_window_change_signal = 1; | |
453 | ||
454 | /* OK, we have been continued by the user. Reinitialize buffers. */ | |
455 | buffer_init(bin); | |
456 | buffer_init(bout); | |
457 | buffer_init(berr); | |
458 | ||
459 | enter_raw_mode(); | |
460 | } | |
461 | ||
462 | static void | |
463 | client_process_net_input(fd_set * readset) | |
464 | { | |
465 | int len; | |
466 | char buf[8192]; | |
467 | ||
468 | /* | |
469 | * Read input from the server, and add any such data to the buffer of | |
470 | * the packet subsystem. | |
471 | */ | |
472 | if (FD_ISSET(connection_in, readset)) { | |
473 | /* Read as much as possible. */ | |
474 | len = read(connection_in, buf, sizeof(buf)); | |
475 | if (len == 0) { | |
476 | /* Received EOF. The remote host has closed the connection. */ | |
477 | snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n", | |
478 | host); | |
479 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
480 | quit_pending = 1; | |
481 | return; | |
482 | } | |
483 | /* | |
484 | * There is a kernel bug on Solaris that causes select to | |
485 | * sometimes wake up even though there is no data available. | |
486 | */ | |
487 | if (len < 0 && (errno == EAGAIN || errno == EINTR)) | |
488 | len = 0; | |
489 | ||
490 | if (len < 0) { | |
491 | /* An error has encountered. Perhaps there is a network problem. */ | |
492 | snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n", | |
493 | host, strerror(errno)); | |
494 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
495 | quit_pending = 1; | |
496 | return; | |
497 | } | |
498 | packet_process_incoming(buf, len); | |
499 | } | |
500 | } | |
501 | ||
502 | static void | |
503 | process_cmdline(void) | |
504 | { | |
505 | void (*handler)(int); | |
506 | char *s, *cmd; | |
507 | u_short fwd_port, fwd_host_port; | |
508 | char buf[1024], sfwd_port[6], sfwd_host_port[6]; | |
509 | int local = 0; | |
510 | ||
511 | leave_raw_mode(); | |
512 | handler = signal(SIGINT, SIG_IGN); | |
513 | cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); | |
514 | if (s == NULL) | |
515 | goto out; | |
516 | while (*s && isspace(*s)) | |
517 | s++; | |
518 | if (*s == 0) | |
519 | goto out; | |
520 | if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) { | |
521 | logit("Invalid command."); | |
522 | goto out; | |
523 | } | |
524 | if (s[1] == 'L') | |
525 | local = 1; | |
526 | if (!local && !compat20) { | |
527 | logit("Not supported for SSH protocol version 1."); | |
528 | goto out; | |
529 | } | |
530 | s += 2; | |
531 | while (*s && isspace(*s)) | |
532 | s++; | |
533 | ||
534 | if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]", | |
535 | sfwd_port, buf, sfwd_host_port) != 3 && | |
536 | sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]", | |
537 | sfwd_port, buf, sfwd_host_port) != 3) { | |
538 | logit("Bad forwarding specification."); | |
539 | goto out; | |
540 | } | |
541 | if ((fwd_port = a2port(sfwd_port)) == 0 || | |
542 | (fwd_host_port = a2port(sfwd_host_port)) == 0) { | |
543 | logit("Bad forwarding port(s)."); | |
544 | goto out; | |
545 | } | |
546 | if (local) { | |
547 | if (channel_setup_local_fwd_listener(fwd_port, buf, | |
548 | fwd_host_port, options.gateway_ports) < 0) { | |
549 | logit("Port forwarding failed."); | |
550 | goto out; | |
551 | } | |
552 | } else | |
553 | channel_request_remote_forwarding(fwd_port, buf, | |
554 | fwd_host_port); | |
555 | logit("Forwarding port."); | |
556 | out: | |
557 | signal(SIGINT, handler); | |
558 | enter_raw_mode(); | |
559 | if (cmd) | |
560 | xfree(cmd); | |
561 | } | |
562 | ||
563 | /* process the characters one by one */ | |
564 | static int | |
565 | process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len) | |
566 | { | |
567 | char string[1024]; | |
568 | pid_t pid; | |
569 | int bytes = 0; | |
570 | u_int i; | |
571 | u_char ch; | |
572 | char *s; | |
573 | ||
574 | for (i = 0; i < len; i++) { | |
575 | /* Get one character at a time. */ | |
576 | ch = buf[i]; | |
577 | ||
578 | if (escape_pending) { | |
579 | /* We have previously seen an escape character. */ | |
580 | /* Clear the flag now. */ | |
581 | escape_pending = 0; | |
582 | ||
583 | /* Process the escaped character. */ | |
584 | switch (ch) { | |
585 | case '.': | |
586 | /* Terminate the connection. */ | |
587 | snprintf(string, sizeof string, "%c.\r\n", escape_char); | |
588 | buffer_append(berr, string, strlen(string)); | |
589 | ||
590 | quit_pending = 1; | |
591 | return -1; | |
592 | ||
593 | case 'Z' - 64: | |
594 | /* Suspend the program. */ | |
595 | /* Print a message to that effect to the user. */ | |
596 | snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char); | |
597 | buffer_append(berr, string, strlen(string)); | |
598 | ||
599 | /* Restore terminal modes and suspend. */ | |
600 | client_suspend_self(bin, bout, berr); | |
601 | ||
602 | /* We have been continued. */ | |
603 | continue; | |
604 | ||
605 | case 'B': | |
606 | if (compat20) { | |
607 | snprintf(string, sizeof string, | |
608 | "%cB\r\n", escape_char); | |
609 | buffer_append(berr, string, | |
610 | strlen(string)); | |
611 | channel_request_start(session_ident, | |
612 | "break", 0); | |
613 | packet_put_int(1000); | |
614 | packet_send(); | |
615 | } | |
616 | continue; | |
617 | ||
618 | case 'R': | |
619 | if (compat20) { | |
620 | if (datafellows & SSH_BUG_NOREKEY) | |
621 | logit("Server does not support re-keying"); | |
622 | else | |
623 | need_rekeying = 1; | |
624 | } | |
625 | continue; | |
626 | ||
627 | case '&': | |
628 | /* | |
629 | * Detach the program (continue to serve connections, | |
630 | * but put in background and no more new connections). | |
631 | */ | |
632 | /* Restore tty modes. */ | |
633 | leave_raw_mode(); | |
634 | ||
635 | /* Stop listening for new connections. */ | |
636 | channel_stop_listening(); | |
637 | ||
638 | snprintf(string, sizeof string, | |
639 | "%c& [backgrounded]\n", escape_char); | |
640 | buffer_append(berr, string, strlen(string)); | |
641 | ||
642 | /* Fork into background. */ | |
643 | pid = fork(); | |
644 | if (pid < 0) { | |
645 | error("fork: %.100s", strerror(errno)); | |
646 | continue; | |
647 | } | |
648 | if (pid != 0) { /* This is the parent. */ | |
649 | /* The parent just exits. */ | |
650 | exit(0); | |
651 | } | |
652 | /* The child continues serving connections. */ | |
653 | if (compat20) { | |
654 | buffer_append(bin, "\004", 1); | |
655 | /* fake EOF on stdin */ | |
656 | return -1; | |
657 | } else if (!stdin_eof) { | |
658 | /* | |
659 | * Sending SSH_CMSG_EOF alone does not always appear | |
660 | * to be enough. So we try to send an EOF character | |
661 | * first. | |
662 | */ | |
663 | packet_start(SSH_CMSG_STDIN_DATA); | |
664 | packet_put_string("\004", 1); | |
665 | packet_send(); | |
666 | /* Close stdin. */ | |
667 | stdin_eof = 1; | |
668 | if (buffer_len(bin) == 0) { | |
669 | packet_start(SSH_CMSG_EOF); | |
670 | packet_send(); | |
671 | } | |
672 | } | |
673 | continue; | |
674 | ||
675 | case '?': | |
676 | snprintf(string, sizeof string, | |
677 | "%c?\r\n\ | |
678 | Supported escape sequences:\r\n\ | |
679 | %c. - terminate connection\r\n\ | |
680 | %cB - send a BREAK to the remote system\r\n\ | |
681 | %cC - open a command line\r\n\ | |
682 | %cR - Request rekey (SSH protocol 2 only)\r\n\ | |
683 | %c^Z - suspend ssh\r\n\ | |
684 | %c# - list forwarded connections\r\n\ | |
685 | %c& - background ssh (when waiting for connections to terminate)\r\n\ | |
686 | %c? - this message\r\n\ | |
687 | %c%c - send the escape character by typing it twice\r\n\ | |
688 | (Note that escapes are only recognized immediately after newline.)\r\n", | |
689 | escape_char, escape_char, escape_char, escape_char, | |
690 | escape_char, escape_char, escape_char, escape_char, | |
691 | escape_char, escape_char, escape_char); | |
692 | buffer_append(berr, string, strlen(string)); | |
693 | continue; | |
694 | ||
695 | case '#': | |
696 | snprintf(string, sizeof string, "%c#\r\n", escape_char); | |
697 | buffer_append(berr, string, strlen(string)); | |
698 | s = channel_open_message(); | |
699 | buffer_append(berr, s, strlen(s)); | |
700 | xfree(s); | |
701 | continue; | |
702 | ||
703 | case 'C': | |
704 | process_cmdline(); | |
705 | continue; | |
706 | ||
707 | default: | |
708 | if (ch != escape_char) { | |
709 | buffer_put_char(bin, escape_char); | |
710 | bytes++; | |
711 | } | |
712 | /* Escaped characters fall through here */ | |
713 | break; | |
714 | } | |
715 | } else { | |
716 | /* | |
717 | * The previous character was not an escape char. Check if this | |
718 | * is an escape. | |
719 | */ | |
720 | if (last_was_cr && ch == escape_char) { | |
721 | /* It is. Set the flag and continue to next character. */ | |
722 | escape_pending = 1; | |
723 | continue; | |
724 | } | |
725 | } | |
726 | ||
727 | /* | |
728 | * Normal character. Record whether it was a newline, | |
729 | * and append it to the buffer. | |
730 | */ | |
731 | last_was_cr = (ch == '\r' || ch == '\n'); | |
732 | buffer_put_char(bin, ch); | |
733 | bytes++; | |
734 | } | |
735 | return bytes; | |
736 | } | |
737 | ||
738 | static void | |
739 | client_process_input(fd_set * readset) | |
740 | { | |
741 | int len; | |
742 | char buf[8192]; | |
743 | ||
744 | /* Read input from stdin. */ | |
745 | if (FD_ISSET(fileno(stdin), readset)) { | |
746 | /* Read as much as possible. */ | |
747 | len = read(fileno(stdin), buf, sizeof(buf)); | |
748 | if (len < 0 && (errno == EAGAIN || errno == EINTR)) | |
749 | return; /* we'll try again later */ | |
750 | if (len <= 0) { | |
751 | /* | |
752 | * Received EOF or error. They are treated | |
753 | * similarly, except that an error message is printed | |
754 | * if it was an error condition. | |
755 | */ | |
756 | if (len < 0) { | |
757 | snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno)); | |
758 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
759 | } | |
760 | /* Mark that we have seen EOF. */ | |
761 | stdin_eof = 1; | |
762 | /* | |
763 | * Send an EOF message to the server unless there is | |
764 | * data in the buffer. If there is data in the | |
765 | * buffer, no message will be sent now. Code | |
766 | * elsewhere will send the EOF when the buffer | |
767 | * becomes empty if stdin_eof is set. | |
768 | */ | |
769 | if (buffer_len(&stdin_buffer) == 0) { | |
770 | packet_start(SSH_CMSG_EOF); | |
771 | packet_send(); | |
772 | } | |
773 | } else if (escape_char == SSH_ESCAPECHAR_NONE) { | |
774 | /* | |
775 | * Normal successful read, and no escape character. | |
776 | * Just append the data to buffer. | |
777 | */ | |
778 | buffer_append(&stdin_buffer, buf, len); | |
779 | } else { | |
780 | /* | |
781 | * Normal, successful read. But we have an escape character | |
782 | * and have to process the characters one by one. | |
783 | */ | |
784 | if (process_escapes(&stdin_buffer, &stdout_buffer, | |
785 | &stderr_buffer, buf, len) == -1) | |
786 | return; | |
787 | } | |
788 | } | |
789 | } | |
790 | ||
791 | static void | |
792 | client_process_output(fd_set * writeset) | |
793 | { | |
794 | int len; | |
795 | char buf[100]; | |
796 | ||
797 | /* Write buffered output to stdout. */ | |
798 | if (FD_ISSET(fileno(stdout), writeset)) { | |
799 | /* Write as much data as possible. */ | |
800 | len = write(fileno(stdout), buffer_ptr(&stdout_buffer), | |
801 | buffer_len(&stdout_buffer)); | |
802 | if (len <= 0) { | |
803 | if (errno == EINTR || errno == EAGAIN) | |
804 | len = 0; | |
805 | else { | |
806 | /* | |
807 | * An error or EOF was encountered. Put an | |
808 | * error message to stderr buffer. | |
809 | */ | |
810 | snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno)); | |
811 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
812 | quit_pending = 1; | |
813 | return; | |
814 | } | |
815 | } | |
816 | /* Consume printed data from the buffer. */ | |
817 | buffer_consume(&stdout_buffer, len); | |
818 | stdout_bytes += len; | |
819 | } | |
820 | /* Write buffered output to stderr. */ | |
821 | if (FD_ISSET(fileno(stderr), writeset)) { | |
822 | /* Write as much data as possible. */ | |
823 | len = write(fileno(stderr), buffer_ptr(&stderr_buffer), | |
824 | buffer_len(&stderr_buffer)); | |
825 | if (len <= 0) { | |
826 | if (errno == EINTR || errno == EAGAIN) | |
827 | len = 0; | |
828 | else { | |
829 | /* EOF or error, but can't even print error message. */ | |
830 | quit_pending = 1; | |
831 | return; | |
832 | } | |
833 | } | |
834 | /* Consume printed characters from the buffer. */ | |
835 | buffer_consume(&stderr_buffer, len); | |
836 | stderr_bytes += len; | |
837 | } | |
838 | } | |
839 | ||
840 | /* | |
841 | * Get packets from the connection input buffer, and process them as long as | |
842 | * there are packets available. | |
843 | * | |
844 | * Any unknown packets received during the actual | |
845 | * session cause the session to terminate. This is | |
846 | * intended to make debugging easier since no | |
847 | * confirmations are sent. Any compatible protocol | |
848 | * extensions must be negotiated during the | |
849 | * preparatory phase. | |
850 | */ | |
851 | ||
852 | static void | |
853 | client_process_buffered_input_packets(void) | |
854 | { | |
855 | dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL); | |
856 | } | |
857 | ||
858 | /* scan buf[] for '~' before sending data to the peer */ | |
859 | ||
860 | static int | |
861 | simple_escape_filter(Channel *c, char *buf, int len) | |
862 | { | |
863 | /* XXX we assume c->extended is writeable */ | |
864 | return process_escapes(&c->input, &c->output, &c->extended, buf, len); | |
865 | } | |
866 | ||
867 | static void | |
868 | client_channel_closed(int id, void *arg) | |
869 | { | |
870 | if (id != session_ident) | |
871 | error("client_channel_closed: id %d != session_ident %d", | |
872 | id, session_ident); | |
873 | channel_cancel_cleanup(id); | |
874 | session_closed = 1; | |
875 | leave_raw_mode(); | |
876 | } | |
877 | ||
878 | /* | |
879 | * Implements the interactive session with the server. This is called after | |
880 | * the user has been authenticated, and a command has been started on the | |
881 | * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character | |
882 | * used as an escape character for terminating or suspending the session. | |
883 | */ | |
884 | ||
885 | int | |
886 | client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) | |
887 | { | |
888 | fd_set *readset = NULL, *writeset = NULL; | |
889 | double start_time, total_time; | |
890 | int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0; | |
891 | char buf[100]; | |
892 | ||
893 | debug("Entering interactive session."); | |
894 | ||
895 | start_time = get_current_time(); | |
896 | ||
897 | /* Initialize variables. */ | |
898 | escape_pending = 0; | |
899 | last_was_cr = 1; | |
900 | exit_status = -1; | |
901 | stdin_eof = 0; | |
902 | buffer_high = 64 * 1024; | |
903 | connection_in = packet_get_connection_in(); | |
904 | connection_out = packet_get_connection_out(); | |
905 | max_fd = MAX(connection_in, connection_out); | |
906 | ||
907 | if (!compat20) { | |
908 | /* enable nonblocking unless tty */ | |
909 | if (!isatty(fileno(stdin))) | |
910 | set_nonblock(fileno(stdin)); | |
911 | if (!isatty(fileno(stdout))) | |
912 | set_nonblock(fileno(stdout)); | |
913 | if (!isatty(fileno(stderr))) | |
914 | set_nonblock(fileno(stderr)); | |
915 | max_fd = MAX(max_fd, fileno(stdin)); | |
916 | max_fd = MAX(max_fd, fileno(stdout)); | |
917 | max_fd = MAX(max_fd, fileno(stderr)); | |
918 | } | |
919 | stdin_bytes = 0; | |
920 | stdout_bytes = 0; | |
921 | stderr_bytes = 0; | |
922 | quit_pending = 0; | |
923 | escape_char = escape_char_arg; | |
924 | ||
925 | /* Initialize buffers. */ | |
926 | buffer_init(&stdin_buffer); | |
927 | buffer_init(&stdout_buffer); | |
928 | buffer_init(&stderr_buffer); | |
929 | ||
930 | client_init_dispatch(); | |
931 | ||
932 | /* | |
933 | * Set signal handlers, (e.g. to restore non-blocking mode) | |
934 | * but don't overwrite SIG_IGN, matches behaviour from rsh(1) | |
935 | */ | |
936 | if (signal(SIGINT, SIG_IGN) != SIG_IGN) | |
937 | signal(SIGINT, signal_handler); | |
938 | if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) | |
939 | signal(SIGQUIT, signal_handler); | |
940 | if (signal(SIGTERM, SIG_IGN) != SIG_IGN) | |
941 | signal(SIGTERM, signal_handler); | |
942 | if (have_pty) | |
943 | signal(SIGWINCH, window_change_handler); | |
944 | ||
945 | if (have_pty) | |
946 | enter_raw_mode(); | |
947 | ||
948 | if (compat20) { | |
949 | session_ident = ssh2_chan_id; | |
950 | if (escape_char != SSH_ESCAPECHAR_NONE) | |
951 | channel_register_filter(session_ident, | |
952 | simple_escape_filter); | |
953 | if (session_ident != -1) | |
954 | channel_register_cleanup(session_ident, | |
955 | client_channel_closed); | |
956 | } else { | |
957 | /* Check if we should immediately send eof on stdin. */ | |
958 | client_check_initial_eof_on_stdin(); | |
959 | } | |
960 | ||
961 | /* Main loop of the client for the interactive session mode. */ | |
962 | while (!quit_pending) { | |
963 | ||
964 | /* Process buffered packets sent by the server. */ | |
965 | client_process_buffered_input_packets(); | |
966 | ||
967 | if (compat20 && session_closed && !channel_still_open()) | |
968 | break; | |
969 | ||
970 | rekeying = (xxx_kex != NULL && !xxx_kex->done); | |
971 | ||
972 | if (rekeying) { | |
973 | debug("rekeying in progress"); | |
974 | } else { | |
975 | /* | |
976 | * Make packets of buffered stdin data, and buffer | |
977 | * them for sending to the server. | |
978 | */ | |
979 | if (!compat20) | |
980 | client_make_packets_from_stdin_data(); | |
981 | ||
982 | /* | |
983 | * Make packets from buffered channel data, and | |
984 | * enqueue them for sending to the server. | |
985 | */ | |
986 | if (packet_not_very_much_data_to_write()) | |
987 | channel_output_poll(); | |
988 | ||
989 | /* | |
990 | * Check if the window size has changed, and buffer a | |
991 | * message about it to the server if so. | |
992 | */ | |
993 | client_check_window_change(); | |
994 | ||
995 | if (quit_pending) | |
996 | break; | |
997 | } | |
998 | /* | |
999 | * Wait until we have something to do (something becomes | |
1000 | * available on one of the descriptors). | |
1001 | */ | |
1002 | max_fd2 = max_fd; | |
1003 | client_wait_until_can_do_something(&readset, &writeset, | |
1004 | &max_fd2, &nalloc, rekeying); | |
1005 | ||
1006 | if (quit_pending) | |
1007 | break; | |
1008 | ||
1009 | /* Do channel operations unless rekeying in progress. */ | |
1010 | if (!rekeying) { | |
1011 | channel_after_select(readset, writeset); | |
1012 | if (need_rekeying || packet_need_rekeying()) { | |
1013 | debug("need rekeying"); | |
1014 | xxx_kex->done = 0; | |
1015 | kex_send_kexinit(xxx_kex); | |
1016 | need_rekeying = 0; | |
1017 | } | |
1018 | } | |
1019 | ||
1020 | /* Buffer input from the connection. */ | |
1021 | client_process_net_input(readset); | |
1022 | ||
1023 | if (quit_pending) | |
1024 | break; | |
1025 | ||
1026 | if (!compat20) { | |
1027 | /* Buffer data from stdin */ | |
1028 | client_process_input(readset); | |
1029 | /* | |
1030 | * Process output to stdout and stderr. Output to | |
1031 | * the connection is processed elsewhere (above). | |
1032 | */ | |
1033 | client_process_output(writeset); | |
1034 | } | |
1035 | ||
1036 | /* Send as much buffered packet data as possible to the sender. */ | |
1037 | if (FD_ISSET(connection_out, writeset)) | |
1038 | packet_write_poll(); | |
1039 | } | |
1040 | if (readset) | |
1041 | xfree(readset); | |
1042 | if (writeset) | |
1043 | xfree(writeset); | |
1044 | ||
1045 | /* Terminate the session. */ | |
1046 | ||
1047 | /* Stop watching for window change. */ | |
1048 | if (have_pty) | |
1049 | signal(SIGWINCH, SIG_DFL); | |
1050 | ||
1051 | channel_free_all(); | |
1052 | ||
1053 | if (have_pty) | |
1054 | leave_raw_mode(); | |
1055 | ||
1056 | /* restore blocking io */ | |
1057 | if (!isatty(fileno(stdin))) | |
1058 | unset_nonblock(fileno(stdin)); | |
1059 | if (!isatty(fileno(stdout))) | |
1060 | unset_nonblock(fileno(stdout)); | |
1061 | if (!isatty(fileno(stderr))) | |
1062 | unset_nonblock(fileno(stderr)); | |
1063 | ||
1064 | /* | |
1065 | * If there was no shell or command requested, there will be no remote | |
1066 | * exit status to be returned. In that case, clear error code if the | |
1067 | * connection was deliberately terminated at this end. | |
1068 | */ | |
1069 | if (no_shell_flag && received_signal == SIGTERM) { | |
1070 | received_signal = 0; | |
1071 | exit_status = 0; | |
1072 | } | |
1073 | ||
1074 | if (received_signal) | |
1075 | fatal("Killed by signal %d.", (int) received_signal); | |
1076 | ||
1077 | /* | |
1078 | * In interactive mode (with pseudo tty) display a message indicating | |
1079 | * that the connection has been closed. | |
1080 | */ | |
1081 | if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { | |
1082 | snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host); | |
1083 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
1084 | } | |
1085 | ||
1086 | /* Output any buffered data for stdout. */ | |
1087 | while (buffer_len(&stdout_buffer) > 0) { | |
1088 | len = write(fileno(stdout), buffer_ptr(&stdout_buffer), | |
1089 | buffer_len(&stdout_buffer)); | |
1090 | if (len <= 0) { | |
1091 | error("Write failed flushing stdout buffer."); | |
1092 | break; | |
1093 | } | |
1094 | buffer_consume(&stdout_buffer, len); | |
1095 | stdout_bytes += len; | |
1096 | } | |
1097 | ||
1098 | /* Output any buffered data for stderr. */ | |
1099 | while (buffer_len(&stderr_buffer) > 0) { | |
1100 | len = write(fileno(stderr), buffer_ptr(&stderr_buffer), | |
1101 | buffer_len(&stderr_buffer)); | |
1102 | if (len <= 0) { | |
1103 | error("Write failed flushing stderr buffer."); | |
1104 | break; | |
1105 | } | |
1106 | buffer_consume(&stderr_buffer, len); | |
1107 | stderr_bytes += len; | |
1108 | } | |
1109 | ||
1110 | /* Clear and free any buffers. */ | |
1111 | memset(buf, 0, sizeof(buf)); | |
1112 | buffer_free(&stdin_buffer); | |
1113 | buffer_free(&stdout_buffer); | |
1114 | buffer_free(&stderr_buffer); | |
1115 | ||
1116 | /* Report bytes transferred, and transfer rates. */ | |
1117 | total_time = get_current_time() - start_time; | |
1118 | debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds", | |
1119 | stdin_bytes, stdout_bytes, stderr_bytes, total_time); | |
1120 | if (total_time > 0) | |
1121 | debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f", | |
1122 | stdin_bytes / total_time, stdout_bytes / total_time, | |
1123 | stderr_bytes / total_time); | |
1124 | ||
1125 | /* Return the exit status of the program. */ | |
1126 | debug("Exit status %d", exit_status); | |
1127 | return exit_status; | |
1128 | } | |
1129 | ||
1130 | /*********/ | |
1131 | ||
1132 | static void | |
1133 | client_input_stdout_data(int type, u_int32_t seq, void *ctxt) | |
1134 | { | |
1135 | u_int data_len; | |
1136 | char *data = packet_get_string(&data_len); | |
1137 | packet_check_eom(); | |
1138 | buffer_append(&stdout_buffer, data, data_len); | |
1139 | memset(data, 0, data_len); | |
1140 | xfree(data); | |
1141 | } | |
1142 | static void | |
1143 | client_input_stderr_data(int type, u_int32_t seq, void *ctxt) | |
1144 | { | |
1145 | u_int data_len; | |
1146 | char *data = packet_get_string(&data_len); | |
1147 | packet_check_eom(); | |
1148 | buffer_append(&stderr_buffer, data, data_len); | |
1149 | memset(data, 0, data_len); | |
1150 | xfree(data); | |
1151 | } | |
1152 | static void | |
1153 | client_input_exit_status(int type, u_int32_t seq, void *ctxt) | |
1154 | { | |
1155 | exit_status = packet_get_int(); | |
1156 | packet_check_eom(); | |
1157 | /* Acknowledge the exit. */ | |
1158 | packet_start(SSH_CMSG_EXIT_CONFIRMATION); | |
1159 | packet_send(); | |
1160 | /* | |
1161 | * Must wait for packet to be sent since we are | |
1162 | * exiting the loop. | |
1163 | */ | |
1164 | packet_write_wait(); | |
1165 | /* Flag that we want to exit. */ | |
1166 | quit_pending = 1; | |
1167 | } | |
1168 | static void | |
1169 | client_input_agent_open(int type, u_int32_t seq, void *ctxt) | |
1170 | { | |
1171 | Channel *c = NULL; | |
1172 | int remote_id, sock; | |
1173 | ||
1174 | /* Read the remote channel number from the message. */ | |
1175 | remote_id = packet_get_int(); | |
1176 | packet_check_eom(); | |
1177 | ||
1178 | /* | |
1179 | * Get a connection to the local authentication agent (this may again | |
1180 | * get forwarded). | |
1181 | */ | |
1182 | sock = ssh_get_authentication_socket(); | |
1183 | ||
1184 | /* | |
1185 | * If we could not connect the agent, send an error message back to | |
1186 | * the server. This should never happen unless the agent dies, | |
1187 | * because authentication forwarding is only enabled if we have an | |
1188 | * agent. | |
1189 | */ | |
1190 | if (sock >= 0) { | |
1191 | c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, | |
1192 | -1, 0, 0, 0, "authentication agent connection", 1); | |
1193 | c->remote_id = remote_id; | |
1194 | c->force_drain = 1; | |
1195 | } | |
1196 | if (c == NULL) { | |
1197 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1198 | packet_put_int(remote_id); | |
1199 | } else { | |
1200 | /* Send a confirmation to the remote host. */ | |
1201 | debug("Forwarding authentication connection."); | |
1202 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1203 | packet_put_int(remote_id); | |
1204 | packet_put_int(c->self); | |
1205 | } | |
1206 | packet_send(); | |
1207 | } | |
1208 | ||
1209 | static Channel * | |
1210 | client_request_forwarded_tcpip(const char *request_type, int rchan) | |
1211 | { | |
1212 | Channel *c = NULL; | |
1213 | char *listen_address, *originator_address; | |
1214 | int listen_port, originator_port; | |
1215 | int sock; | |
1216 | ||
1217 | /* Get rest of the packet */ | |
1218 | listen_address = packet_get_string(NULL); | |
1219 | listen_port = packet_get_int(); | |
1220 | originator_address = packet_get_string(NULL); | |
1221 | originator_port = packet_get_int(); | |
1222 | packet_check_eom(); | |
1223 | ||
1224 | debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d", | |
1225 | listen_address, listen_port, originator_address, originator_port); | |
1226 | ||
1227 | sock = channel_connect_by_listen_address(listen_port); | |
1228 | if (sock < 0) { | |
1229 | xfree(originator_address); | |
1230 | xfree(listen_address); | |
1231 | return NULL; | |
1232 | } | |
1233 | c = channel_new("forwarded-tcpip", | |
1234 | SSH_CHANNEL_CONNECTING, sock, sock, -1, | |
1235 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, | |
1236 | originator_address, 1); | |
1237 | xfree(originator_address); | |
1238 | xfree(listen_address); | |
1239 | return c; | |
1240 | } | |
1241 | ||
1242 | static Channel * | |
1243 | client_request_x11(const char *request_type, int rchan) | |
1244 | { | |
1245 | Channel *c = NULL; | |
1246 | char *originator; | |
1247 | int originator_port; | |
1248 | int sock; | |
1249 | ||
1250 | if (!options.forward_x11) { | |
1251 | error("Warning: ssh server tried X11 forwarding."); | |
1252 | error("Warning: this is probably a break in attempt by a malicious server."); | |
1253 | return NULL; | |
1254 | } | |
1255 | originator = packet_get_string(NULL); | |
1256 | if (datafellows & SSH_BUG_X11FWD) { | |
1257 | debug2("buggy server: x11 request w/o originator_port"); | |
1258 | originator_port = 0; | |
1259 | } else { | |
1260 | originator_port = packet_get_int(); | |
1261 | } | |
1262 | packet_check_eom(); | |
1263 | /* XXX check permission */ | |
1264 | debug("client_request_x11: request from %s %d", originator, | |
1265 | originator_port); | |
1266 | xfree(originator); | |
1267 | sock = x11_connect_display(); | |
1268 | if (sock < 0) | |
1269 | return NULL; | |
1270 | c = channel_new("x11", | |
1271 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, | |
1272 | CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); | |
1273 | c->force_drain = 1; | |
1274 | return c; | |
1275 | } | |
1276 | ||
1277 | static Channel * | |
1278 | client_request_agent(const char *request_type, int rchan) | |
1279 | { | |
1280 | Channel *c = NULL; | |
1281 | int sock; | |
1282 | ||
1283 | if (!options.forward_agent) { | |
1284 | error("Warning: ssh server tried agent forwarding."); | |
1285 | error("Warning: this is probably a break in attempt by a malicious server."); | |
1286 | return NULL; | |
1287 | } | |
1288 | sock = ssh_get_authentication_socket(); | |
1289 | if (sock < 0) | |
1290 | return NULL; | |
1291 | c = channel_new("authentication agent connection", | |
1292 | SSH_CHANNEL_OPEN, sock, sock, -1, | |
1293 | CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, | |
1294 | "authentication agent connection", 1); | |
1295 | c->force_drain = 1; | |
1296 | return c; | |
1297 | } | |
1298 | ||
1299 | /* XXXX move to generic input handler */ | |
1300 | static void | |
1301 | client_input_channel_open(int type, u_int32_t seq, void *ctxt) | |
1302 | { | |
1303 | Channel *c = NULL; | |
1304 | char *ctype; | |
1305 | int rchan; | |
1306 | u_int rmaxpack, rwindow, len; | |
1307 | ||
1308 | ctype = packet_get_string(&len); | |
1309 | rchan = packet_get_int(); | |
1310 | rwindow = packet_get_int(); | |
1311 | rmaxpack = packet_get_int(); | |
1312 | ||
1313 | debug("client_input_channel_open: ctype %s rchan %d win %d max %d", | |
1314 | ctype, rchan, rwindow, rmaxpack); | |
1315 | ||
1316 | if (strcmp(ctype, "forwarded-tcpip") == 0) { | |
1317 | c = client_request_forwarded_tcpip(ctype, rchan); | |
1318 | } else if (strcmp(ctype, "x11") == 0) { | |
1319 | c = client_request_x11(ctype, rchan); | |
1320 | } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { | |
1321 | c = client_request_agent(ctype, rchan); | |
1322 | } | |
1323 | /* XXX duplicate : */ | |
1324 | if (c != NULL) { | |
1325 | debug("confirm %s", ctype); | |
1326 | c->remote_id = rchan; | |
1327 | c->remote_window = rwindow; | |
1328 | c->remote_maxpacket = rmaxpack; | |
1329 | if (c->type != SSH_CHANNEL_CONNECTING) { | |
1330 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1331 | packet_put_int(c->remote_id); | |
1332 | packet_put_int(c->self); | |
1333 | packet_put_int(c->local_window); | |
1334 | packet_put_int(c->local_maxpacket); | |
1335 | packet_send(); | |
1336 | } | |
1337 | } else { | |
1338 | debug("failure %s", ctype); | |
1339 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1340 | packet_put_int(rchan); | |
1341 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
1342 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1343 | packet_put_cstring("open failed"); | |
1344 | packet_put_cstring(""); | |
1345 | } | |
1346 | packet_send(); | |
1347 | } | |
1348 | xfree(ctype); | |
1349 | } | |
1350 | static void | |
1351 | client_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1352 | { | |
1353 | Channel *c = NULL; | |
1354 | int id, reply, success = 0; | |
1355 | char *rtype; | |
1356 | ||
1357 | id = packet_get_int(); | |
1358 | rtype = packet_get_string(NULL); | |
1359 | reply = packet_get_char(); | |
1360 | ||
1361 | debug("client_input_channel_req: channel %d rtype %s reply %d", | |
1362 | id, rtype, reply); | |
1363 | ||
1364 | if (session_ident == -1) { | |
1365 | error("client_input_channel_req: no channel %d", session_ident); | |
1366 | } else if (id != session_ident) { | |
1367 | error("client_input_channel_req: channel %d: wrong channel: %d", | |
1368 | session_ident, id); | |
1369 | } | |
1370 | c = channel_lookup(id); | |
1371 | if (c == NULL) { | |
1372 | error("client_input_channel_req: channel %d: unknown channel", id); | |
1373 | } else if (strcmp(rtype, "exit-status") == 0) { | |
1374 | success = 1; | |
1375 | exit_status = packet_get_int(); | |
1376 | packet_check_eom(); | |
1377 | } | |
1378 | if (reply) { | |
1379 | packet_start(success ? | |
1380 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1381 | packet_put_int(c->remote_id); | |
1382 | packet_send(); | |
1383 | } | |
1384 | xfree(rtype); | |
1385 | } | |
1386 | static void | |
1387 | client_input_global_request(int type, u_int32_t seq, void *ctxt) | |
1388 | { | |
1389 | char *rtype; | |
1390 | int want_reply; | |
1391 | int success = 0; | |
1392 | ||
1393 | rtype = packet_get_string(NULL); | |
1394 | want_reply = packet_get_char(); | |
1395 | debug("client_input_global_request: rtype %s want_reply %d", | |
1396 | rtype, want_reply); | |
1397 | if (want_reply) { | |
1398 | packet_start(success ? | |
1399 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1400 | packet_send(); | |
1401 | packet_write_wait(); | |
1402 | } | |
1403 | xfree(rtype); | |
1404 | } | |
1405 | ||
1406 | static void | |
1407 | client_init_dispatch_20(void) | |
1408 | { | |
1409 | dispatch_init(&dispatch_protocol_error); | |
1410 | ||
1411 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1412 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1413 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1414 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1415 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); | |
1416 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1417 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1418 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); | |
1419 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); | |
1420 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); | |
1421 | ||
1422 | /* rekeying */ | |
1423 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
1424 | ||
1425 | /* global request reply messages */ | |
1426 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); | |
1427 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); | |
1428 | } | |
1429 | static void | |
1430 | client_init_dispatch_13(void) | |
1431 | { | |
1432 | dispatch_init(NULL); | |
1433 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1434 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1435 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1436 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1437 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1438 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1439 | dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); | |
1440 | dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); | |
1441 | dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); | |
1442 | ||
1443 | dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? | |
1444 | &client_input_agent_open : &deny_input_open); | |
1445 | dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? | |
1446 | &x11_input_open : &deny_input_open); | |
1447 | } | |
1448 | static void | |
1449 | client_init_dispatch_15(void) | |
1450 | { | |
1451 | client_init_dispatch_13(); | |
1452 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1453 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); | |
1454 | } | |
1455 | static void | |
1456 | client_init_dispatch(void) | |
1457 | { | |
1458 | if (compat20) | |
1459 | client_init_dispatch_20(); | |
1460 | else if (compat13) | |
1461 | client_init_dispatch_13(); | |
1462 | else | |
1463 | client_init_dispatch_15(); | |
1464 | } | |
1465 | ||
1466 | /* client specific fatal cleanup */ | |
1467 | void | |
1468 | cleanup_exit(int i) | |
1469 | { | |
1470 | leave_raw_mode(); | |
1471 | leave_non_blocking(); | |
1472 | _exit(i); | |
1473 | } |