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1 | /* $OpenBSD: clientloop.c,v 1.172 2006/07/26 02:35:17 stevesk 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 <string.h> | |
82 | #include <termios.h> | |
83 | #include <unistd.h> | |
84 | ||
85 | #include "ssh.h" | |
86 | #include "ssh1.h" | |
87 | #include "ssh2.h" | |
88 | #include "xmalloc.h" | |
89 | #include "packet.h" | |
90 | #include "buffer.h" | |
91 | #include "compat.h" | |
92 | #include "channels.h" | |
93 | #include "dispatch.h" | |
94 | #include "buffer.h" | |
95 | #include "bufaux.h" | |
96 | #include "key.h" | |
97 | #include "kex.h" | |
98 | #include "log.h" | |
99 | #include "readconf.h" | |
100 | #include "clientloop.h" | |
101 | #include "sshconnect.h" | |
102 | #include "authfd.h" | |
103 | #include "atomicio.h" | |
104 | #include "sshpty.h" | |
105 | #include "misc.h" | |
106 | #include "monitor_fdpass.h" | |
107 | #include "match.h" | |
108 | #include "msg.h" | |
109 | ||
110 | /* import options */ | |
111 | extern Options options; | |
112 | ||
113 | /* Flag indicating that stdin should be redirected from /dev/null. */ | |
114 | extern int stdin_null_flag; | |
115 | ||
116 | /* Flag indicating that no shell has been requested */ | |
117 | extern int no_shell_flag; | |
118 | ||
119 | /* Control socket */ | |
120 | extern int control_fd; | |
121 | ||
122 | /* | |
123 | * Name of the host we are connecting to. This is the name given on the | |
124 | * command line, or the HostName specified for the user-supplied name in a | |
125 | * configuration file. | |
126 | */ | |
127 | extern char *host; | |
128 | ||
129 | /* | |
130 | * Flag to indicate that we have received a window change signal which has | |
131 | * not yet been processed. This will cause a message indicating the new | |
132 | * window size to be sent to the server a little later. This is volatile | |
133 | * because this is updated in a signal handler. | |
134 | */ | |
135 | static volatile sig_atomic_t received_window_change_signal = 0; | |
136 | static volatile sig_atomic_t received_signal = 0; | |
137 | ||
138 | /* Flag indicating whether the user's terminal is in non-blocking mode. */ | |
139 | static int in_non_blocking_mode = 0; | |
140 | ||
141 | /* Common data for the client loop code. */ | |
142 | static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ | |
143 | static int escape_char; /* Escape character. */ | |
144 | static int escape_pending; /* Last character was the escape character */ | |
145 | static int last_was_cr; /* Last character was a newline. */ | |
146 | static int exit_status; /* Used to store the exit status of the command. */ | |
147 | static int stdin_eof; /* EOF has been encountered on standard error. */ | |
148 | static Buffer stdin_buffer; /* Buffer for stdin data. */ | |
149 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
150 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
151 | static u_long stdin_bytes, stdout_bytes, stderr_bytes; | |
152 | static u_int buffer_high;/* Soft max buffer size. */ | |
153 | static int connection_in; /* Connection to server (input). */ | |
154 | static int connection_out; /* Connection to server (output). */ | |
155 | static int need_rekeying; /* Set to non-zero if rekeying is requested. */ | |
156 | static int session_closed = 0; /* In SSH2: login session closed. */ | |
157 | static int server_alive_timeouts = 0; | |
158 | ||
159 | static void client_init_dispatch(void); | |
160 | int session_ident = -1; | |
161 | ||
162 | struct confirm_ctx { | |
163 | int want_tty; | |
164 | int want_subsys; | |
165 | int want_x_fwd; | |
166 | int want_agent_fwd; | |
167 | Buffer cmd; | |
168 | char *term; | |
169 | struct termios tio; | |
170 | char **env; | |
171 | }; | |
172 | ||
173 | /*XXX*/ | |
174 | extern Kex *xxx_kex; | |
175 | ||
176 | void ssh_process_session2_setup(int, int, int, Buffer *); | |
177 | ||
178 | /* Restores stdin to blocking mode. */ | |
179 | ||
180 | static void | |
181 | leave_non_blocking(void) | |
182 | { | |
183 | if (in_non_blocking_mode) { | |
184 | unset_nonblock(fileno(stdin)); | |
185 | in_non_blocking_mode = 0; | |
186 | } | |
187 | } | |
188 | ||
189 | /* Puts stdin terminal in non-blocking mode. */ | |
190 | ||
191 | static void | |
192 | enter_non_blocking(void) | |
193 | { | |
194 | in_non_blocking_mode = 1; | |
195 | set_nonblock(fileno(stdin)); | |
196 | } | |
197 | ||
198 | /* | |
199 | * Signal handler for the window change signal (SIGWINCH). This just sets a | |
200 | * flag indicating that the window has changed. | |
201 | */ | |
202 | /*ARGSUSED */ | |
203 | static void | |
204 | window_change_handler(int sig) | |
205 | { | |
206 | received_window_change_signal = 1; | |
207 | signal(SIGWINCH, window_change_handler); | |
208 | } | |
209 | ||
210 | /* | |
211 | * Signal handler for signals that cause the program to terminate. These | |
212 | * signals must be trapped to restore terminal modes. | |
213 | */ | |
214 | /*ARGSUSED */ | |
215 | static void | |
216 | signal_handler(int sig) | |
217 | { | |
218 | received_signal = sig; | |
219 | quit_pending = 1; | |
220 | } | |
221 | ||
222 | /* | |
223 | * Returns current time in seconds from Jan 1, 1970 with the maximum | |
224 | * available resolution. | |
225 | */ | |
226 | ||
227 | static double | |
228 | get_current_time(void) | |
229 | { | |
230 | struct timeval tv; | |
231 | gettimeofday(&tv, NULL); | |
232 | return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; | |
233 | } | |
234 | ||
235 | #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" | |
236 | void | |
237 | client_x11_get_proto(const char *display, const char *xauth_path, | |
238 | u_int trusted, char **_proto, char **_data) | |
239 | { | |
240 | char cmd[1024]; | |
241 | char line[512]; | |
242 | char xdisplay[512]; | |
243 | static char proto[512], data[512]; | |
244 | FILE *f; | |
245 | int got_data = 0, generated = 0, do_unlink = 0, i; | |
246 | char *xauthdir, *xauthfile; | |
247 | struct stat st; | |
248 | ||
249 | xauthdir = xauthfile = NULL; | |
250 | *_proto = proto; | |
251 | *_data = data; | |
252 | proto[0] = data[0] = '\0'; | |
253 | ||
254 | if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { | |
255 | debug("No xauth program."); | |
256 | } else { | |
257 | if (display == NULL) { | |
258 | debug("x11_get_proto: DISPLAY not set"); | |
259 | return; | |
260 | } | |
261 | /* | |
262 | * Handle FamilyLocal case where $DISPLAY does | |
263 | * not match an authorization entry. For this we | |
264 | * just try "xauth list unix:displaynum.screennum". | |
265 | * XXX: "localhost" match to determine FamilyLocal | |
266 | * is not perfect. | |
267 | */ | |
268 | if (strncmp(display, "localhost:", 10) == 0) { | |
269 | snprintf(xdisplay, sizeof(xdisplay), "unix:%s", | |
270 | display + 10); | |
271 | display = xdisplay; | |
272 | } | |
273 | if (trusted == 0) { | |
274 | xauthdir = xmalloc(MAXPATHLEN); | |
275 | xauthfile = xmalloc(MAXPATHLEN); | |
276 | strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); | |
277 | if (mkdtemp(xauthdir) != NULL) { | |
278 | do_unlink = 1; | |
279 | snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", | |
280 | xauthdir); | |
281 | snprintf(cmd, sizeof(cmd), | |
282 | "%s -f %s generate %s " SSH_X11_PROTO | |
283 | " untrusted timeout 1200 2>" _PATH_DEVNULL, | |
284 | xauth_path, xauthfile, display); | |
285 | debug2("x11_get_proto: %s", cmd); | |
286 | if (system(cmd) == 0) | |
287 | generated = 1; | |
288 | } | |
289 | } | |
290 | snprintf(cmd, sizeof(cmd), | |
291 | "%s %s%s list %s 2>" _PATH_DEVNULL, | |
292 | xauth_path, | |
293 | generated ? "-f " : "" , | |
294 | generated ? xauthfile : "", | |
295 | display); | |
296 | debug2("x11_get_proto: %s", cmd); | |
297 | f = popen(cmd, "r"); | |
298 | if (f && fgets(line, sizeof(line), f) && | |
299 | sscanf(line, "%*s %511s %511s", proto, data) == 2) | |
300 | got_data = 1; | |
301 | if (f) | |
302 | pclose(f); | |
303 | } | |
304 | ||
305 | if (do_unlink) { | |
306 | unlink(xauthfile); | |
307 | rmdir(xauthdir); | |
308 | } | |
309 | if (xauthdir) | |
310 | xfree(xauthdir); | |
311 | if (xauthfile) | |
312 | xfree(xauthfile); | |
313 | ||
314 | /* | |
315 | * If we didn't get authentication data, just make up some | |
316 | * data. The forwarding code will check the validity of the | |
317 | * response anyway, and substitute this data. The X11 | |
318 | * server, however, will ignore this fake data and use | |
319 | * whatever authentication mechanisms it was using otherwise | |
320 | * for the local connection. | |
321 | */ | |
322 | if (!got_data) { | |
323 | u_int32_t rnd = 0; | |
324 | ||
325 | logit("Warning: No xauth data; " | |
326 | "using fake authentication data for X11 forwarding."); | |
327 | strlcpy(proto, SSH_X11_PROTO, sizeof proto); | |
328 | for (i = 0; i < 16; i++) { | |
329 | if (i % 4 == 0) | |
330 | rnd = arc4random(); | |
331 | snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", | |
332 | rnd & 0xff); | |
333 | rnd >>= 8; | |
334 | } | |
335 | } | |
336 | } | |
337 | ||
338 | /* | |
339 | * This is called when the interactive is entered. This checks if there is | |
340 | * an EOF coming on stdin. We must check this explicitly, as select() does | |
341 | * not appear to wake up when redirecting from /dev/null. | |
342 | */ | |
343 | ||
344 | static void | |
345 | client_check_initial_eof_on_stdin(void) | |
346 | { | |
347 | int len; | |
348 | char buf[1]; | |
349 | ||
350 | /* | |
351 | * If standard input is to be "redirected from /dev/null", we simply | |
352 | * mark that we have seen an EOF and send an EOF message to the | |
353 | * server. Otherwise, we try to read a single character; it appears | |
354 | * that for some files, such /dev/null, select() never wakes up for | |
355 | * read for this descriptor, which means that we never get EOF. This | |
356 | * way we will get the EOF if stdin comes from /dev/null or similar. | |
357 | */ | |
358 | if (stdin_null_flag) { | |
359 | /* Fake EOF on stdin. */ | |
360 | debug("Sending eof."); | |
361 | stdin_eof = 1; | |
362 | packet_start(SSH_CMSG_EOF); | |
363 | packet_send(); | |
364 | } else { | |
365 | enter_non_blocking(); | |
366 | ||
367 | /* Check for immediate EOF on stdin. */ | |
368 | len = read(fileno(stdin), buf, 1); | |
369 | if (len == 0) { | |
370 | /* EOF. Record that we have seen it and send EOF to server. */ | |
371 | debug("Sending eof."); | |
372 | stdin_eof = 1; | |
373 | packet_start(SSH_CMSG_EOF); | |
374 | packet_send(); | |
375 | } else if (len > 0) { | |
376 | /* | |
377 | * Got data. We must store the data in the buffer, | |
378 | * and also process it as an escape character if | |
379 | * appropriate. | |
380 | */ | |
381 | if ((u_char) buf[0] == escape_char) | |
382 | escape_pending = 1; | |
383 | else | |
384 | buffer_append(&stdin_buffer, buf, 1); | |
385 | } | |
386 | leave_non_blocking(); | |
387 | } | |
388 | } | |
389 | ||
390 | ||
391 | /* | |
392 | * Make packets from buffered stdin data, and buffer them for sending to the | |
393 | * connection. | |
394 | */ | |
395 | ||
396 | static void | |
397 | client_make_packets_from_stdin_data(void) | |
398 | { | |
399 | u_int len; | |
400 | ||
401 | /* Send buffered stdin data to the server. */ | |
402 | while (buffer_len(&stdin_buffer) > 0 && | |
403 | packet_not_very_much_data_to_write()) { | |
404 | len = buffer_len(&stdin_buffer); | |
405 | /* Keep the packets at reasonable size. */ | |
406 | if (len > packet_get_maxsize()) | |
407 | len = packet_get_maxsize(); | |
408 | packet_start(SSH_CMSG_STDIN_DATA); | |
409 | packet_put_string(buffer_ptr(&stdin_buffer), len); | |
410 | packet_send(); | |
411 | buffer_consume(&stdin_buffer, len); | |
412 | stdin_bytes += len; | |
413 | /* If we have a pending EOF, send it now. */ | |
414 | if (stdin_eof && buffer_len(&stdin_buffer) == 0) { | |
415 | packet_start(SSH_CMSG_EOF); | |
416 | packet_send(); | |
417 | } | |
418 | } | |
419 | } | |
420 | ||
421 | /* | |
422 | * Checks if the client window has changed, and sends a packet about it to | |
423 | * the server if so. The actual change is detected elsewhere (by a software | |
424 | * interrupt on Unix); this just checks the flag and sends a message if | |
425 | * appropriate. | |
426 | */ | |
427 | ||
428 | static void | |
429 | client_check_window_change(void) | |
430 | { | |
431 | struct winsize ws; | |
432 | ||
433 | if (! received_window_change_signal) | |
434 | return; | |
435 | /** XXX race */ | |
436 | received_window_change_signal = 0; | |
437 | ||
438 | debug2("client_check_window_change: changed"); | |
439 | ||
440 | if (compat20) { | |
441 | channel_send_window_changes(); | |
442 | } else { | |
443 | if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) | |
444 | return; | |
445 | packet_start(SSH_CMSG_WINDOW_SIZE); | |
446 | packet_put_int((u_int)ws.ws_row); | |
447 | packet_put_int((u_int)ws.ws_col); | |
448 | packet_put_int((u_int)ws.ws_xpixel); | |
449 | packet_put_int((u_int)ws.ws_ypixel); | |
450 | packet_send(); | |
451 | } | |
452 | } | |
453 | ||
454 | static void | |
455 | client_global_request_reply(int type, u_int32_t seq, void *ctxt) | |
456 | { | |
457 | server_alive_timeouts = 0; | |
458 | client_global_request_reply_fwd(type, seq, ctxt); | |
459 | } | |
460 | ||
461 | static void | |
462 | server_alive_check(void) | |
463 | { | |
464 | if (++server_alive_timeouts > options.server_alive_count_max) | |
465 | packet_disconnect("Timeout, server not responding."); | |
466 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
467 | packet_put_cstring("keepalive@openssh.com"); | |
468 | packet_put_char(1); /* boolean: want reply */ | |
469 | packet_send(); | |
470 | } | |
471 | ||
472 | /* | |
473 | * Waits until the client can do something (some data becomes available on | |
474 | * one of the file descriptors). | |
475 | */ | |
476 | static void | |
477 | client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, | |
478 | int *maxfdp, u_int *nallocp, int rekeying) | |
479 | { | |
480 | struct timeval tv, *tvp; | |
481 | int ret; | |
482 | ||
483 | /* Add any selections by the channel mechanism. */ | |
484 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); | |
485 | ||
486 | if (!compat20) { | |
487 | /* Read from the connection, unless our buffers are full. */ | |
488 | if (buffer_len(&stdout_buffer) < buffer_high && | |
489 | buffer_len(&stderr_buffer) < buffer_high && | |
490 | channel_not_very_much_buffered_data()) | |
491 | FD_SET(connection_in, *readsetp); | |
492 | /* | |
493 | * Read from stdin, unless we have seen EOF or have very much | |
494 | * buffered data to send to the server. | |
495 | */ | |
496 | if (!stdin_eof && packet_not_very_much_data_to_write()) | |
497 | FD_SET(fileno(stdin), *readsetp); | |
498 | ||
499 | /* Select stdout/stderr if have data in buffer. */ | |
500 | if (buffer_len(&stdout_buffer) > 0) | |
501 | FD_SET(fileno(stdout), *writesetp); | |
502 | if (buffer_len(&stderr_buffer) > 0) | |
503 | FD_SET(fileno(stderr), *writesetp); | |
504 | } else { | |
505 | /* channel_prepare_select could have closed the last channel */ | |
506 | if (session_closed && !channel_still_open() && | |
507 | !packet_have_data_to_write()) { | |
508 | /* clear mask since we did not call select() */ | |
509 | memset(*readsetp, 0, *nallocp); | |
510 | memset(*writesetp, 0, *nallocp); | |
511 | return; | |
512 | } else { | |
513 | FD_SET(connection_in, *readsetp); | |
514 | } | |
515 | } | |
516 | ||
517 | /* Select server connection if have data to write to the server. */ | |
518 | if (packet_have_data_to_write()) | |
519 | FD_SET(connection_out, *writesetp); | |
520 | ||
521 | if (control_fd != -1) | |
522 | FD_SET(control_fd, *readsetp); | |
523 | ||
524 | /* | |
525 | * Wait for something to happen. This will suspend the process until | |
526 | * some selected descriptor can be read, written, or has some other | |
527 | * event pending. | |
528 | */ | |
529 | ||
530 | if (options.server_alive_interval == 0 || !compat20) | |
531 | tvp = NULL; | |
532 | else { | |
533 | tv.tv_sec = options.server_alive_interval; | |
534 | tv.tv_usec = 0; | |
535 | tvp = &tv; | |
536 | } | |
537 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); | |
538 | if (ret < 0) { | |
539 | char buf[100]; | |
540 | ||
541 | /* | |
542 | * We have to clear the select masks, because we return. | |
543 | * We have to return, because the mainloop checks for the flags | |
544 | * set by the signal handlers. | |
545 | */ | |
546 | memset(*readsetp, 0, *nallocp); | |
547 | memset(*writesetp, 0, *nallocp); | |
548 | ||
549 | if (errno == EINTR) | |
550 | return; | |
551 | /* Note: we might still have data in the buffers. */ | |
552 | snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); | |
553 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
554 | quit_pending = 1; | |
555 | } else if (ret == 0) | |
556 | server_alive_check(); | |
557 | } | |
558 | ||
559 | static void | |
560 | client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) | |
561 | { | |
562 | /* Flush stdout and stderr buffers. */ | |
563 | if (buffer_len(bout) > 0) | |
564 | atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout)); | |
565 | if (buffer_len(berr) > 0) | |
566 | atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr)); | |
567 | ||
568 | leave_raw_mode(); | |
569 | ||
570 | /* | |
571 | * Free (and clear) the buffer to reduce the amount of data that gets | |
572 | * written to swap. | |
573 | */ | |
574 | buffer_free(bin); | |
575 | buffer_free(bout); | |
576 | buffer_free(berr); | |
577 | ||
578 | /* Send the suspend signal to the program itself. */ | |
579 | kill(getpid(), SIGTSTP); | |
580 | ||
581 | /* Reset window sizes in case they have changed */ | |
582 | received_window_change_signal = 1; | |
583 | ||
584 | /* OK, we have been continued by the user. Reinitialize buffers. */ | |
585 | buffer_init(bin); | |
586 | buffer_init(bout); | |
587 | buffer_init(berr); | |
588 | ||
589 | enter_raw_mode(); | |
590 | } | |
591 | ||
592 | static void | |
593 | client_process_net_input(fd_set *readset) | |
594 | { | |
595 | int len; | |
596 | char buf[8192]; | |
597 | ||
598 | /* | |
599 | * Read input from the server, and add any such data to the buffer of | |
600 | * the packet subsystem. | |
601 | */ | |
602 | if (FD_ISSET(connection_in, readset)) { | |
603 | /* Read as much as possible. */ | |
604 | len = read(connection_in, buf, sizeof(buf)); | |
605 | if (len == 0) { | |
606 | /* Received EOF. The remote host has closed the connection. */ | |
607 | snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n", | |
608 | host); | |
609 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
610 | quit_pending = 1; | |
611 | return; | |
612 | } | |
613 | /* | |
614 | * There is a kernel bug on Solaris that causes select to | |
615 | * sometimes wake up even though there is no data available. | |
616 | */ | |
617 | if (len < 0 && (errno == EAGAIN || errno == EINTR)) | |
618 | len = 0; | |
619 | ||
620 | if (len < 0) { | |
621 | /* An error has encountered. Perhaps there is a network problem. */ | |
622 | snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n", | |
623 | host, strerror(errno)); | |
624 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
625 | quit_pending = 1; | |
626 | return; | |
627 | } | |
628 | packet_process_incoming(buf, len); | |
629 | } | |
630 | } | |
631 | ||
632 | static void | |
633 | client_subsystem_reply(int type, u_int32_t seq, void *ctxt) | |
634 | { | |
635 | int id; | |
636 | Channel *c; | |
637 | ||
638 | id = packet_get_int(); | |
639 | packet_check_eom(); | |
640 | ||
641 | if ((c = channel_lookup(id)) == NULL) { | |
642 | error("%s: no channel for id %d", __func__, id); | |
643 | return; | |
644 | } | |
645 | ||
646 | if (type == SSH2_MSG_CHANNEL_SUCCESS) | |
647 | debug2("Request suceeded on channel %d", id); | |
648 | else if (type == SSH2_MSG_CHANNEL_FAILURE) { | |
649 | error("Request failed on channel %d", id); | |
650 | channel_free(c); | |
651 | } | |
652 | } | |
653 | ||
654 | static void | |
655 | client_extra_session2_setup(int id, void *arg) | |
656 | { | |
657 | struct confirm_ctx *cctx = arg; | |
658 | const char *display; | |
659 | Channel *c; | |
660 | int i; | |
661 | ||
662 | if (cctx == NULL) | |
663 | fatal("%s: cctx == NULL", __func__); | |
664 | if ((c = channel_lookup(id)) == NULL) | |
665 | fatal("%s: no channel for id %d", __func__, id); | |
666 | ||
667 | display = getenv("DISPLAY"); | |
668 | if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { | |
669 | char *proto, *data; | |
670 | /* Get reasonable local authentication information. */ | |
671 | client_x11_get_proto(display, options.xauth_location, | |
672 | options.forward_x11_trusted, &proto, &data); | |
673 | /* Request forwarding with authentication spoofing. */ | |
674 | debug("Requesting X11 forwarding with authentication spoofing."); | |
675 | x11_request_forwarding_with_spoofing(id, display, proto, data); | |
676 | /* XXX wait for reply */ | |
677 | } | |
678 | ||
679 | if (cctx->want_agent_fwd && options.forward_agent) { | |
680 | debug("Requesting authentication agent forwarding."); | |
681 | channel_request_start(id, "auth-agent-req@openssh.com", 0); | |
682 | packet_send(); | |
683 | } | |
684 | ||
685 | client_session2_setup(id, cctx->want_tty, cctx->want_subsys, | |
686 | cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env, | |
687 | client_subsystem_reply); | |
688 | ||
689 | c->confirm_ctx = NULL; | |
690 | buffer_free(&cctx->cmd); | |
691 | xfree(cctx->term); | |
692 | if (cctx->env != NULL) { | |
693 | for (i = 0; cctx->env[i] != NULL; i++) | |
694 | xfree(cctx->env[i]); | |
695 | xfree(cctx->env); | |
696 | } | |
697 | xfree(cctx); | |
698 | } | |
699 | ||
700 | static void | |
701 | client_process_control(fd_set *readset) | |
702 | { | |
703 | Buffer m; | |
704 | Channel *c; | |
705 | int client_fd, new_fd[3], ver, allowed; | |
706 | socklen_t addrlen; | |
707 | struct sockaddr_storage addr; | |
708 | struct confirm_ctx *cctx; | |
709 | char *cmd; | |
710 | u_int i, len, env_len, command, flags; | |
711 | uid_t euid; | |
712 | gid_t egid; | |
713 | ||
714 | /* | |
715 | * Accept connection on control socket | |
716 | */ | |
717 | if (control_fd == -1 || !FD_ISSET(control_fd, readset)) | |
718 | return; | |
719 | ||
720 | memset(&addr, 0, sizeof(addr)); | |
721 | addrlen = sizeof(addr); | |
722 | if ((client_fd = accept(control_fd, | |
723 | (struct sockaddr*)&addr, &addrlen)) == -1) { | |
724 | error("%s accept: %s", __func__, strerror(errno)); | |
725 | return; | |
726 | } | |
727 | ||
728 | if (getpeereid(client_fd, &euid, &egid) < 0) { | |
729 | error("%s getpeereid failed: %s", __func__, strerror(errno)); | |
730 | close(client_fd); | |
731 | return; | |
732 | } | |
733 | if ((euid != 0) && (getuid() != euid)) { | |
734 | error("control mode uid mismatch: peer euid %u != uid %u", | |
735 | (u_int) euid, (u_int) getuid()); | |
736 | close(client_fd); | |
737 | return; | |
738 | } | |
739 | ||
740 | unset_nonblock(client_fd); | |
741 | ||
742 | /* Read command */ | |
743 | buffer_init(&m); | |
744 | if (ssh_msg_recv(client_fd, &m) == -1) { | |
745 | error("%s: client msg_recv failed", __func__); | |
746 | close(client_fd); | |
747 | buffer_free(&m); | |
748 | return; | |
749 | } | |
750 | if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { | |
751 | error("%s: wrong client version %d", __func__, ver); | |
752 | buffer_free(&m); | |
753 | close(client_fd); | |
754 | return; | |
755 | } | |
756 | ||
757 | allowed = 1; | |
758 | command = buffer_get_int(&m); | |
759 | flags = buffer_get_int(&m); | |
760 | ||
761 | buffer_clear(&m); | |
762 | ||
763 | switch (command) { | |
764 | case SSHMUX_COMMAND_OPEN: | |
765 | if (options.control_master == SSHCTL_MASTER_ASK || | |
766 | options.control_master == SSHCTL_MASTER_AUTO_ASK) | |
767 | allowed = ask_permission("Allow shared connection " | |
768 | "to %s? ", host); | |
769 | /* continue below */ | |
770 | break; | |
771 | case SSHMUX_COMMAND_TERMINATE: | |
772 | if (options.control_master == SSHCTL_MASTER_ASK || | |
773 | options.control_master == SSHCTL_MASTER_AUTO_ASK) | |
774 | allowed = ask_permission("Terminate shared connection " | |
775 | "to %s? ", host); | |
776 | if (allowed) | |
777 | quit_pending = 1; | |
778 | /* FALLTHROUGH */ | |
779 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
780 | /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */ | |
781 | buffer_clear(&m); | |
782 | buffer_put_int(&m, allowed); | |
783 | buffer_put_int(&m, getpid()); | |
784 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
785 | error("%s: client msg_send failed", __func__); | |
786 | close(client_fd); | |
787 | buffer_free(&m); | |
788 | return; | |
789 | } | |
790 | buffer_free(&m); | |
791 | close(client_fd); | |
792 | return; | |
793 | default: | |
794 | error("Unsupported command %d", command); | |
795 | buffer_free(&m); | |
796 | close(client_fd); | |
797 | return; | |
798 | } | |
799 | ||
800 | /* Reply for SSHMUX_COMMAND_OPEN */ | |
801 | buffer_clear(&m); | |
802 | buffer_put_int(&m, allowed); | |
803 | buffer_put_int(&m, getpid()); | |
804 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
805 | error("%s: client msg_send failed", __func__); | |
806 | close(client_fd); | |
807 | buffer_free(&m); | |
808 | return; | |
809 | } | |
810 | ||
811 | if (!allowed) { | |
812 | error("Refused control connection"); | |
813 | close(client_fd); | |
814 | buffer_free(&m); | |
815 | return; | |
816 | } | |
817 | ||
818 | buffer_clear(&m); | |
819 | if (ssh_msg_recv(client_fd, &m) == -1) { | |
820 | error("%s: client msg_recv failed", __func__); | |
821 | close(client_fd); | |
822 | buffer_free(&m); | |
823 | return; | |
824 | } | |
825 | if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { | |
826 | error("%s: wrong client version %d", __func__, ver); | |
827 | buffer_free(&m); | |
828 | close(client_fd); | |
829 | return; | |
830 | } | |
831 | ||
832 | cctx = xcalloc(1, sizeof(*cctx)); | |
833 | cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0; | |
834 | cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0; | |
835 | cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0; | |
836 | cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0; | |
837 | cctx->term = buffer_get_string(&m, &len); | |
838 | ||
839 | cmd = buffer_get_string(&m, &len); | |
840 | buffer_init(&cctx->cmd); | |
841 | buffer_append(&cctx->cmd, cmd, strlen(cmd)); | |
842 | ||
843 | env_len = buffer_get_int(&m); | |
844 | env_len = MIN(env_len, 4096); | |
845 | debug3("%s: receiving %d env vars", __func__, env_len); | |
846 | if (env_len != 0) { | |
847 | cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env)); | |
848 | for (i = 0; i < env_len; i++) | |
849 | cctx->env[i] = buffer_get_string(&m, &len); | |
850 | cctx->env[i] = NULL; | |
851 | } | |
852 | ||
853 | debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__, | |
854 | cctx->want_tty, cctx->want_subsys, cmd); | |
855 | xfree(cmd); | |
856 | ||
857 | /* Gather fds from client */ | |
858 | new_fd[0] = mm_receive_fd(client_fd); | |
859 | new_fd[1] = mm_receive_fd(client_fd); | |
860 | new_fd[2] = mm_receive_fd(client_fd); | |
861 | ||
862 | debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__, | |
863 | new_fd[0], new_fd[1], new_fd[2]); | |
864 | ||
865 | /* Try to pick up ttymodes from client before it goes raw */ | |
866 | if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1) | |
867 | error("%s: tcgetattr: %s", __func__, strerror(errno)); | |
868 | ||
869 | /* This roundtrip is just for synchronisation of ttymodes */ | |
870 | buffer_clear(&m); | |
871 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
872 | error("%s: client msg_send failed", __func__); | |
873 | close(client_fd); | |
874 | close(new_fd[0]); | |
875 | close(new_fd[1]); | |
876 | close(new_fd[2]); | |
877 | buffer_free(&m); | |
878 | xfree(cctx->term); | |
879 | if (env_len != 0) { | |
880 | for (i = 0; i < env_len; i++) | |
881 | xfree(cctx->env[i]); | |
882 | xfree(cctx->env); | |
883 | } | |
884 | return; | |
885 | } | |
886 | buffer_free(&m); | |
887 | ||
888 | /* enable nonblocking unless tty */ | |
889 | if (!isatty(new_fd[0])) | |
890 | set_nonblock(new_fd[0]); | |
891 | if (!isatty(new_fd[1])) | |
892 | set_nonblock(new_fd[1]); | |
893 | if (!isatty(new_fd[2])) | |
894 | set_nonblock(new_fd[2]); | |
895 | ||
896 | set_nonblock(client_fd); | |
897 | ||
898 | c = channel_new("session", SSH_CHANNEL_OPENING, | |
899 | new_fd[0], new_fd[1], new_fd[2], | |
900 | CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT, | |
901 | CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); | |
902 | ||
903 | /* XXX */ | |
904 | c->ctl_fd = client_fd; | |
905 | ||
906 | debug3("%s: channel_new: %d", __func__, c->self); | |
907 | ||
908 | channel_send_open(c->self); | |
909 | channel_register_confirm(c->self, client_extra_session2_setup, cctx); | |
910 | } | |
911 | ||
912 | static void | |
913 | process_cmdline(void) | |
914 | { | |
915 | void (*handler)(int); | |
916 | char *s, *cmd, *cancel_host; | |
917 | int delete = 0; | |
918 | int local = 0; | |
919 | u_short cancel_port; | |
920 | Forward fwd; | |
921 | ||
922 | leave_raw_mode(); | |
923 | handler = signal(SIGINT, SIG_IGN); | |
924 | cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); | |
925 | if (s == NULL) | |
926 | goto out; | |
927 | while (*s && isspace(*s)) | |
928 | s++; | |
929 | if (*s == '-') | |
930 | s++; /* Skip cmdline '-', if any */ | |
931 | if (*s == '\0') | |
932 | goto out; | |
933 | ||
934 | if (*s == 'h' || *s == 'H' || *s == '?') { | |
935 | logit("Commands:"); | |
936 | logit(" -L[bind_address:]port:host:hostport " | |
937 | "Request local forward"); | |
938 | logit(" -R[bind_address:]port:host:hostport " | |
939 | "Request remote forward"); | |
940 | logit(" -KR[bind_address:]port " | |
941 | "Cancel remote forward"); | |
942 | if (!options.permit_local_command) | |
943 | goto out; | |
944 | logit(" !args " | |
945 | "Execute local command"); | |
946 | goto out; | |
947 | } | |
948 | ||
949 | if (*s == '!' && options.permit_local_command) { | |
950 | s++; | |
951 | ssh_local_cmd(s); | |
952 | goto out; | |
953 | } | |
954 | ||
955 | if (*s == 'K') { | |
956 | delete = 1; | |
957 | s++; | |
958 | } | |
959 | if (*s != 'L' && *s != 'R') { | |
960 | logit("Invalid command."); | |
961 | goto out; | |
962 | } | |
963 | if (*s == 'L') | |
964 | local = 1; | |
965 | if (local && delete) { | |
966 | logit("Not supported."); | |
967 | goto out; | |
968 | } | |
969 | if ((!local || delete) && !compat20) { | |
970 | logit("Not supported for SSH protocol version 1."); | |
971 | goto out; | |
972 | } | |
973 | ||
974 | s++; | |
975 | while (*s && isspace(*s)) | |
976 | s++; | |
977 | ||
978 | if (delete) { | |
979 | cancel_port = 0; | |
980 | cancel_host = hpdelim(&s); /* may be NULL */ | |
981 | if (s != NULL) { | |
982 | cancel_port = a2port(s); | |
983 | cancel_host = cleanhostname(cancel_host); | |
984 | } else { | |
985 | cancel_port = a2port(cancel_host); | |
986 | cancel_host = NULL; | |
987 | } | |
988 | if (cancel_port == 0) { | |
989 | logit("Bad forwarding close port"); | |
990 | goto out; | |
991 | } | |
992 | channel_request_rforward_cancel(cancel_host, cancel_port); | |
993 | } else { | |
994 | if (!parse_forward(&fwd, s)) { | |
995 | logit("Bad forwarding specification."); | |
996 | goto out; | |
997 | } | |
998 | if (local) { | |
999 | if (channel_setup_local_fwd_listener(fwd.listen_host, | |
1000 | fwd.listen_port, fwd.connect_host, | |
1001 | fwd.connect_port, options.gateway_ports) < 0) { | |
1002 | logit("Port forwarding failed."); | |
1003 | goto out; | |
1004 | } | |
1005 | } else { | |
1006 | if (channel_request_remote_forwarding(fwd.listen_host, | |
1007 | fwd.listen_port, fwd.connect_host, | |
1008 | fwd.connect_port) < 0) { | |
1009 | logit("Port forwarding failed."); | |
1010 | goto out; | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | logit("Forwarding port."); | |
1015 | } | |
1016 | ||
1017 | out: | |
1018 | signal(SIGINT, handler); | |
1019 | enter_raw_mode(); | |
1020 | if (cmd) | |
1021 | xfree(cmd); | |
1022 | } | |
1023 | ||
1024 | /* process the characters one by one */ | |
1025 | static int | |
1026 | process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len) | |
1027 | { | |
1028 | char string[1024]; | |
1029 | pid_t pid; | |
1030 | int bytes = 0; | |
1031 | u_int i; | |
1032 | u_char ch; | |
1033 | char *s; | |
1034 | ||
1035 | if (len <= 0) | |
1036 | return (0); | |
1037 | ||
1038 | for (i = 0; i < (u_int)len; i++) { | |
1039 | /* Get one character at a time. */ | |
1040 | ch = buf[i]; | |
1041 | ||
1042 | if (escape_pending) { | |
1043 | /* We have previously seen an escape character. */ | |
1044 | /* Clear the flag now. */ | |
1045 | escape_pending = 0; | |
1046 | ||
1047 | /* Process the escaped character. */ | |
1048 | switch (ch) { | |
1049 | case '.': | |
1050 | /* Terminate the connection. */ | |
1051 | snprintf(string, sizeof string, "%c.\r\n", escape_char); | |
1052 | buffer_append(berr, string, strlen(string)); | |
1053 | ||
1054 | quit_pending = 1; | |
1055 | return -1; | |
1056 | ||
1057 | case 'Z' - 64: | |
1058 | /* Suspend the program. */ | |
1059 | /* Print a message to that effect to the user. */ | |
1060 | snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char); | |
1061 | buffer_append(berr, string, strlen(string)); | |
1062 | ||
1063 | /* Restore terminal modes and suspend. */ | |
1064 | client_suspend_self(bin, bout, berr); | |
1065 | ||
1066 | /* We have been continued. */ | |
1067 | continue; | |
1068 | ||
1069 | case 'B': | |
1070 | if (compat20) { | |
1071 | snprintf(string, sizeof string, | |
1072 | "%cB\r\n", escape_char); | |
1073 | buffer_append(berr, string, | |
1074 | strlen(string)); | |
1075 | channel_request_start(session_ident, | |
1076 | "break", 0); | |
1077 | packet_put_int(1000); | |
1078 | packet_send(); | |
1079 | } | |
1080 | continue; | |
1081 | ||
1082 | case 'R': | |
1083 | if (compat20) { | |
1084 | if (datafellows & SSH_BUG_NOREKEY) | |
1085 | logit("Server does not support re-keying"); | |
1086 | else | |
1087 | need_rekeying = 1; | |
1088 | } | |
1089 | continue; | |
1090 | ||
1091 | case '&': | |
1092 | /* | |
1093 | * Detach the program (continue to serve connections, | |
1094 | * but put in background and no more new connections). | |
1095 | */ | |
1096 | /* Restore tty modes. */ | |
1097 | leave_raw_mode(); | |
1098 | ||
1099 | /* Stop listening for new connections. */ | |
1100 | channel_stop_listening(); | |
1101 | ||
1102 | snprintf(string, sizeof string, | |
1103 | "%c& [backgrounded]\n", escape_char); | |
1104 | buffer_append(berr, string, strlen(string)); | |
1105 | ||
1106 | /* Fork into background. */ | |
1107 | pid = fork(); | |
1108 | if (pid < 0) { | |
1109 | error("fork: %.100s", strerror(errno)); | |
1110 | continue; | |
1111 | } | |
1112 | if (pid != 0) { /* This is the parent. */ | |
1113 | /* The parent just exits. */ | |
1114 | exit(0); | |
1115 | } | |
1116 | /* The child continues serving connections. */ | |
1117 | if (compat20) { | |
1118 | buffer_append(bin, "\004", 1); | |
1119 | /* fake EOF on stdin */ | |
1120 | return -1; | |
1121 | } else if (!stdin_eof) { | |
1122 | /* | |
1123 | * Sending SSH_CMSG_EOF alone does not always appear | |
1124 | * to be enough. So we try to send an EOF character | |
1125 | * first. | |
1126 | */ | |
1127 | packet_start(SSH_CMSG_STDIN_DATA); | |
1128 | packet_put_string("\004", 1); | |
1129 | packet_send(); | |
1130 | /* Close stdin. */ | |
1131 | stdin_eof = 1; | |
1132 | if (buffer_len(bin) == 0) { | |
1133 | packet_start(SSH_CMSG_EOF); | |
1134 | packet_send(); | |
1135 | } | |
1136 | } | |
1137 | continue; | |
1138 | ||
1139 | case '?': | |
1140 | snprintf(string, sizeof string, | |
1141 | "%c?\r\n\ | |
1142 | Supported escape sequences:\r\n\ | |
1143 | %c. - terminate connection\r\n\ | |
1144 | %cB - send a BREAK to the remote system\r\n\ | |
1145 | %cC - open a command line\r\n\ | |
1146 | %cR - Request rekey (SSH protocol 2 only)\r\n\ | |
1147 | %c^Z - suspend ssh\r\n\ | |
1148 | %c# - list forwarded connections\r\n\ | |
1149 | %c& - background ssh (when waiting for connections to terminate)\r\n\ | |
1150 | %c? - this message\r\n\ | |
1151 | %c%c - send the escape character by typing it twice\r\n\ | |
1152 | (Note that escapes are only recognized immediately after newline.)\r\n", | |
1153 | escape_char, escape_char, escape_char, escape_char, | |
1154 | escape_char, escape_char, escape_char, escape_char, | |
1155 | escape_char, escape_char, escape_char); | |
1156 | buffer_append(berr, string, strlen(string)); | |
1157 | continue; | |
1158 | ||
1159 | case '#': | |
1160 | snprintf(string, sizeof string, "%c#\r\n", escape_char); | |
1161 | buffer_append(berr, string, strlen(string)); | |
1162 | s = channel_open_message(); | |
1163 | buffer_append(berr, s, strlen(s)); | |
1164 | xfree(s); | |
1165 | continue; | |
1166 | ||
1167 | case 'C': | |
1168 | process_cmdline(); | |
1169 | continue; | |
1170 | ||
1171 | default: | |
1172 | if (ch != escape_char) { | |
1173 | buffer_put_char(bin, escape_char); | |
1174 | bytes++; | |
1175 | } | |
1176 | /* Escaped characters fall through here */ | |
1177 | break; | |
1178 | } | |
1179 | } else { | |
1180 | /* | |
1181 | * The previous character was not an escape char. Check if this | |
1182 | * is an escape. | |
1183 | */ | |
1184 | if (last_was_cr && ch == escape_char) { | |
1185 | /* It is. Set the flag and continue to next character. */ | |
1186 | escape_pending = 1; | |
1187 | continue; | |
1188 | } | |
1189 | } | |
1190 | ||
1191 | /* | |
1192 | * Normal character. Record whether it was a newline, | |
1193 | * and append it to the buffer. | |
1194 | */ | |
1195 | last_was_cr = (ch == '\r' || ch == '\n'); | |
1196 | buffer_put_char(bin, ch); | |
1197 | bytes++; | |
1198 | } | |
1199 | return bytes; | |
1200 | } | |
1201 | ||
1202 | static void | |
1203 | client_process_input(fd_set *readset) | |
1204 | { | |
1205 | int len; | |
1206 | char buf[8192]; | |
1207 | ||
1208 | /* Read input from stdin. */ | |
1209 | if (FD_ISSET(fileno(stdin), readset)) { | |
1210 | /* Read as much as possible. */ | |
1211 | len = read(fileno(stdin), buf, sizeof(buf)); | |
1212 | if (len < 0 && (errno == EAGAIN || errno == EINTR)) | |
1213 | return; /* we'll try again later */ | |
1214 | if (len <= 0) { | |
1215 | /* | |
1216 | * Received EOF or error. They are treated | |
1217 | * similarly, except that an error message is printed | |
1218 | * if it was an error condition. | |
1219 | */ | |
1220 | if (len < 0) { | |
1221 | snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno)); | |
1222 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
1223 | } | |
1224 | /* Mark that we have seen EOF. */ | |
1225 | stdin_eof = 1; | |
1226 | /* | |
1227 | * Send an EOF message to the server unless there is | |
1228 | * data in the buffer. If there is data in the | |
1229 | * buffer, no message will be sent now. Code | |
1230 | * elsewhere will send the EOF when the buffer | |
1231 | * becomes empty if stdin_eof is set. | |
1232 | */ | |
1233 | if (buffer_len(&stdin_buffer) == 0) { | |
1234 | packet_start(SSH_CMSG_EOF); | |
1235 | packet_send(); | |
1236 | } | |
1237 | } else if (escape_char == SSH_ESCAPECHAR_NONE) { | |
1238 | /* | |
1239 | * Normal successful read, and no escape character. | |
1240 | * Just append the data to buffer. | |
1241 | */ | |
1242 | buffer_append(&stdin_buffer, buf, len); | |
1243 | } else { | |
1244 | /* | |
1245 | * Normal, successful read. But we have an escape character | |
1246 | * and have to process the characters one by one. | |
1247 | */ | |
1248 | if (process_escapes(&stdin_buffer, &stdout_buffer, | |
1249 | &stderr_buffer, buf, len) == -1) | |
1250 | return; | |
1251 | } | |
1252 | } | |
1253 | } | |
1254 | ||
1255 | static void | |
1256 | client_process_output(fd_set *writeset) | |
1257 | { | |
1258 | int len; | |
1259 | char buf[100]; | |
1260 | ||
1261 | /* Write buffered output to stdout. */ | |
1262 | if (FD_ISSET(fileno(stdout), writeset)) { | |
1263 | /* Write as much data as possible. */ | |
1264 | len = write(fileno(stdout), buffer_ptr(&stdout_buffer), | |
1265 | buffer_len(&stdout_buffer)); | |
1266 | if (len <= 0) { | |
1267 | if (errno == EINTR || errno == EAGAIN) | |
1268 | len = 0; | |
1269 | else { | |
1270 | /* | |
1271 | * An error or EOF was encountered. Put an | |
1272 | * error message to stderr buffer. | |
1273 | */ | |
1274 | snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno)); | |
1275 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
1276 | quit_pending = 1; | |
1277 | return; | |
1278 | } | |
1279 | } | |
1280 | /* Consume printed data from the buffer. */ | |
1281 | buffer_consume(&stdout_buffer, len); | |
1282 | stdout_bytes += len; | |
1283 | } | |
1284 | /* Write buffered output to stderr. */ | |
1285 | if (FD_ISSET(fileno(stderr), writeset)) { | |
1286 | /* Write as much data as possible. */ | |
1287 | len = write(fileno(stderr), buffer_ptr(&stderr_buffer), | |
1288 | buffer_len(&stderr_buffer)); | |
1289 | if (len <= 0) { | |
1290 | if (errno == EINTR || errno == EAGAIN) | |
1291 | len = 0; | |
1292 | else { | |
1293 | /* EOF or error, but can't even print error message. */ | |
1294 | quit_pending = 1; | |
1295 | return; | |
1296 | } | |
1297 | } | |
1298 | /* Consume printed characters from the buffer. */ | |
1299 | buffer_consume(&stderr_buffer, len); | |
1300 | stderr_bytes += len; | |
1301 | } | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * Get packets from the connection input buffer, and process them as long as | |
1306 | * there are packets available. | |
1307 | * | |
1308 | * Any unknown packets received during the actual | |
1309 | * session cause the session to terminate. This is | |
1310 | * intended to make debugging easier since no | |
1311 | * confirmations are sent. Any compatible protocol | |
1312 | * extensions must be negotiated during the | |
1313 | * preparatory phase. | |
1314 | */ | |
1315 | ||
1316 | static void | |
1317 | client_process_buffered_input_packets(void) | |
1318 | { | |
1319 | dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL); | |
1320 | } | |
1321 | ||
1322 | /* scan buf[] for '~' before sending data to the peer */ | |
1323 | ||
1324 | static int | |
1325 | simple_escape_filter(Channel *c, char *buf, int len) | |
1326 | { | |
1327 | /* XXX we assume c->extended is writeable */ | |
1328 | return process_escapes(&c->input, &c->output, &c->extended, buf, len); | |
1329 | } | |
1330 | ||
1331 | static void | |
1332 | client_channel_closed(int id, void *arg) | |
1333 | { | |
1334 | channel_cancel_cleanup(id); | |
1335 | session_closed = 1; | |
1336 | leave_raw_mode(); | |
1337 | } | |
1338 | ||
1339 | /* | |
1340 | * Implements the interactive session with the server. This is called after | |
1341 | * the user has been authenticated, and a command has been started on the | |
1342 | * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character | |
1343 | * used as an escape character for terminating or suspending the session. | |
1344 | */ | |
1345 | ||
1346 | int | |
1347 | client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) | |
1348 | { | |
1349 | fd_set *readset = NULL, *writeset = NULL; | |
1350 | double start_time, total_time; | |
1351 | int max_fd = 0, max_fd2 = 0, len, rekeying = 0; | |
1352 | u_int nalloc = 0; | |
1353 | char buf[100]; | |
1354 | ||
1355 | debug("Entering interactive session."); | |
1356 | ||
1357 | start_time = get_current_time(); | |
1358 | ||
1359 | /* Initialize variables. */ | |
1360 | escape_pending = 0; | |
1361 | last_was_cr = 1; | |
1362 | exit_status = -1; | |
1363 | stdin_eof = 0; | |
1364 | buffer_high = 64 * 1024; | |
1365 | connection_in = packet_get_connection_in(); | |
1366 | connection_out = packet_get_connection_out(); | |
1367 | max_fd = MAX(connection_in, connection_out); | |
1368 | if (control_fd != -1) | |
1369 | max_fd = MAX(max_fd, control_fd); | |
1370 | ||
1371 | if (!compat20) { | |
1372 | /* enable nonblocking unless tty */ | |
1373 | if (!isatty(fileno(stdin))) | |
1374 | set_nonblock(fileno(stdin)); | |
1375 | if (!isatty(fileno(stdout))) | |
1376 | set_nonblock(fileno(stdout)); | |
1377 | if (!isatty(fileno(stderr))) | |
1378 | set_nonblock(fileno(stderr)); | |
1379 | max_fd = MAX(max_fd, fileno(stdin)); | |
1380 | max_fd = MAX(max_fd, fileno(stdout)); | |
1381 | max_fd = MAX(max_fd, fileno(stderr)); | |
1382 | } | |
1383 | stdin_bytes = 0; | |
1384 | stdout_bytes = 0; | |
1385 | stderr_bytes = 0; | |
1386 | quit_pending = 0; | |
1387 | escape_char = escape_char_arg; | |
1388 | ||
1389 | /* Initialize buffers. */ | |
1390 | buffer_init(&stdin_buffer); | |
1391 | buffer_init(&stdout_buffer); | |
1392 | buffer_init(&stderr_buffer); | |
1393 | ||
1394 | client_init_dispatch(); | |
1395 | ||
1396 | /* | |
1397 | * Set signal handlers, (e.g. to restore non-blocking mode) | |
1398 | * but don't overwrite SIG_IGN, matches behaviour from rsh(1) | |
1399 | */ | |
1400 | if (signal(SIGHUP, SIG_IGN) != SIG_IGN) | |
1401 | signal(SIGHUP, signal_handler); | |
1402 | if (signal(SIGINT, SIG_IGN) != SIG_IGN) | |
1403 | signal(SIGINT, signal_handler); | |
1404 | if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) | |
1405 | signal(SIGQUIT, signal_handler); | |
1406 | if (signal(SIGTERM, SIG_IGN) != SIG_IGN) | |
1407 | signal(SIGTERM, signal_handler); | |
1408 | signal(SIGWINCH, window_change_handler); | |
1409 | ||
1410 | if (have_pty) | |
1411 | enter_raw_mode(); | |
1412 | ||
1413 | if (compat20) { | |
1414 | session_ident = ssh2_chan_id; | |
1415 | if (escape_char != SSH_ESCAPECHAR_NONE) | |
1416 | channel_register_filter(session_ident, | |
1417 | simple_escape_filter, NULL); | |
1418 | if (session_ident != -1) | |
1419 | channel_register_cleanup(session_ident, | |
1420 | client_channel_closed, 0); | |
1421 | } else { | |
1422 | /* Check if we should immediately send eof on stdin. */ | |
1423 | client_check_initial_eof_on_stdin(); | |
1424 | } | |
1425 | ||
1426 | /* Main loop of the client for the interactive session mode. */ | |
1427 | while (!quit_pending) { | |
1428 | ||
1429 | /* Process buffered packets sent by the server. */ | |
1430 | client_process_buffered_input_packets(); | |
1431 | ||
1432 | if (compat20 && session_closed && !channel_still_open()) | |
1433 | break; | |
1434 | ||
1435 | rekeying = (xxx_kex != NULL && !xxx_kex->done); | |
1436 | ||
1437 | if (rekeying) { | |
1438 | debug("rekeying in progress"); | |
1439 | } else { | |
1440 | /* | |
1441 | * Make packets of buffered stdin data, and buffer | |
1442 | * them for sending to the server. | |
1443 | */ | |
1444 | if (!compat20) | |
1445 | client_make_packets_from_stdin_data(); | |
1446 | ||
1447 | /* | |
1448 | * Make packets from buffered channel data, and | |
1449 | * enqueue them for sending to the server. | |
1450 | */ | |
1451 | if (packet_not_very_much_data_to_write()) | |
1452 | channel_output_poll(); | |
1453 | ||
1454 | /* | |
1455 | * Check if the window size has changed, and buffer a | |
1456 | * message about it to the server if so. | |
1457 | */ | |
1458 | client_check_window_change(); | |
1459 | ||
1460 | if (quit_pending) | |
1461 | break; | |
1462 | } | |
1463 | /* | |
1464 | * Wait until we have something to do (something becomes | |
1465 | * available on one of the descriptors). | |
1466 | */ | |
1467 | max_fd2 = max_fd; | |
1468 | client_wait_until_can_do_something(&readset, &writeset, | |
1469 | &max_fd2, &nalloc, rekeying); | |
1470 | ||
1471 | if (quit_pending) | |
1472 | break; | |
1473 | ||
1474 | /* Do channel operations unless rekeying in progress. */ | |
1475 | if (!rekeying) { | |
1476 | channel_after_select(readset, writeset); | |
1477 | if (need_rekeying || packet_need_rekeying()) { | |
1478 | debug("need rekeying"); | |
1479 | xxx_kex->done = 0; | |
1480 | kex_send_kexinit(xxx_kex); | |
1481 | need_rekeying = 0; | |
1482 | } | |
1483 | } | |
1484 | ||
1485 | /* Buffer input from the connection. */ | |
1486 | client_process_net_input(readset); | |
1487 | ||
1488 | /* Accept control connections. */ | |
1489 | client_process_control(readset); | |
1490 | ||
1491 | if (quit_pending) | |
1492 | break; | |
1493 | ||
1494 | if (!compat20) { | |
1495 | /* Buffer data from stdin */ | |
1496 | client_process_input(readset); | |
1497 | /* | |
1498 | * Process output to stdout and stderr. Output to | |
1499 | * the connection is processed elsewhere (above). | |
1500 | */ | |
1501 | client_process_output(writeset); | |
1502 | } | |
1503 | ||
1504 | /* Send as much buffered packet data as possible to the sender. */ | |
1505 | if (FD_ISSET(connection_out, writeset)) | |
1506 | packet_write_poll(); | |
1507 | } | |
1508 | if (readset) | |
1509 | xfree(readset); | |
1510 | if (writeset) | |
1511 | xfree(writeset); | |
1512 | ||
1513 | /* Terminate the session. */ | |
1514 | ||
1515 | /* Stop watching for window change. */ | |
1516 | signal(SIGWINCH, SIG_DFL); | |
1517 | ||
1518 | channel_free_all(); | |
1519 | ||
1520 | if (have_pty) | |
1521 | leave_raw_mode(); | |
1522 | ||
1523 | /* restore blocking io */ | |
1524 | if (!isatty(fileno(stdin))) | |
1525 | unset_nonblock(fileno(stdin)); | |
1526 | if (!isatty(fileno(stdout))) | |
1527 | unset_nonblock(fileno(stdout)); | |
1528 | if (!isatty(fileno(stderr))) | |
1529 | unset_nonblock(fileno(stderr)); | |
1530 | ||
1531 | /* | |
1532 | * If there was no shell or command requested, there will be no remote | |
1533 | * exit status to be returned. In that case, clear error code if the | |
1534 | * connection was deliberately terminated at this end. | |
1535 | */ | |
1536 | if (no_shell_flag && received_signal == SIGTERM) { | |
1537 | received_signal = 0; | |
1538 | exit_status = 0; | |
1539 | } | |
1540 | ||
1541 | if (received_signal) | |
1542 | fatal("Killed by signal %d.", (int) received_signal); | |
1543 | ||
1544 | /* | |
1545 | * In interactive mode (with pseudo tty) display a message indicating | |
1546 | * that the connection has been closed. | |
1547 | */ | |
1548 | if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { | |
1549 | snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host); | |
1550 | buffer_append(&stderr_buffer, buf, strlen(buf)); | |
1551 | } | |
1552 | ||
1553 | /* Output any buffered data for stdout. */ | |
1554 | while (buffer_len(&stdout_buffer) > 0) { | |
1555 | len = write(fileno(stdout), buffer_ptr(&stdout_buffer), | |
1556 | buffer_len(&stdout_buffer)); | |
1557 | if (len <= 0) { | |
1558 | error("Write failed flushing stdout buffer."); | |
1559 | break; | |
1560 | } | |
1561 | buffer_consume(&stdout_buffer, len); | |
1562 | stdout_bytes += len; | |
1563 | } | |
1564 | ||
1565 | /* Output any buffered data for stderr. */ | |
1566 | while (buffer_len(&stderr_buffer) > 0) { | |
1567 | len = write(fileno(stderr), buffer_ptr(&stderr_buffer), | |
1568 | buffer_len(&stderr_buffer)); | |
1569 | if (len <= 0) { | |
1570 | error("Write failed flushing stderr buffer."); | |
1571 | break; | |
1572 | } | |
1573 | buffer_consume(&stderr_buffer, len); | |
1574 | stderr_bytes += len; | |
1575 | } | |
1576 | ||
1577 | /* Clear and free any buffers. */ | |
1578 | memset(buf, 0, sizeof(buf)); | |
1579 | buffer_free(&stdin_buffer); | |
1580 | buffer_free(&stdout_buffer); | |
1581 | buffer_free(&stderr_buffer); | |
1582 | ||
1583 | /* Report bytes transferred, and transfer rates. */ | |
1584 | total_time = get_current_time() - start_time; | |
1585 | debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds", | |
1586 | stdin_bytes, stdout_bytes, stderr_bytes, total_time); | |
1587 | if (total_time > 0) | |
1588 | debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f", | |
1589 | stdin_bytes / total_time, stdout_bytes / total_time, | |
1590 | stderr_bytes / total_time); | |
1591 | ||
1592 | /* Return the exit status of the program. */ | |
1593 | debug("Exit status %d", exit_status); | |
1594 | return exit_status; | |
1595 | } | |
1596 | ||
1597 | /*********/ | |
1598 | ||
1599 | static void | |
1600 | client_input_stdout_data(int type, u_int32_t seq, void *ctxt) | |
1601 | { | |
1602 | u_int data_len; | |
1603 | char *data = packet_get_string(&data_len); | |
1604 | packet_check_eom(); | |
1605 | buffer_append(&stdout_buffer, data, data_len); | |
1606 | memset(data, 0, data_len); | |
1607 | xfree(data); | |
1608 | } | |
1609 | static void | |
1610 | client_input_stderr_data(int type, u_int32_t seq, void *ctxt) | |
1611 | { | |
1612 | u_int data_len; | |
1613 | char *data = packet_get_string(&data_len); | |
1614 | packet_check_eom(); | |
1615 | buffer_append(&stderr_buffer, data, data_len); | |
1616 | memset(data, 0, data_len); | |
1617 | xfree(data); | |
1618 | } | |
1619 | static void | |
1620 | client_input_exit_status(int type, u_int32_t seq, void *ctxt) | |
1621 | { | |
1622 | exit_status = packet_get_int(); | |
1623 | packet_check_eom(); | |
1624 | /* Acknowledge the exit. */ | |
1625 | packet_start(SSH_CMSG_EXIT_CONFIRMATION); | |
1626 | packet_send(); | |
1627 | /* | |
1628 | * Must wait for packet to be sent since we are | |
1629 | * exiting the loop. | |
1630 | */ | |
1631 | packet_write_wait(); | |
1632 | /* Flag that we want to exit. */ | |
1633 | quit_pending = 1; | |
1634 | } | |
1635 | static void | |
1636 | client_input_agent_open(int type, u_int32_t seq, void *ctxt) | |
1637 | { | |
1638 | Channel *c = NULL; | |
1639 | int remote_id, sock; | |
1640 | ||
1641 | /* Read the remote channel number from the message. */ | |
1642 | remote_id = packet_get_int(); | |
1643 | packet_check_eom(); | |
1644 | ||
1645 | /* | |
1646 | * Get a connection to the local authentication agent (this may again | |
1647 | * get forwarded). | |
1648 | */ | |
1649 | sock = ssh_get_authentication_socket(); | |
1650 | ||
1651 | /* | |
1652 | * If we could not connect the agent, send an error message back to | |
1653 | * the server. This should never happen unless the agent dies, | |
1654 | * because authentication forwarding is only enabled if we have an | |
1655 | * agent. | |
1656 | */ | |
1657 | if (sock >= 0) { | |
1658 | c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, | |
1659 | -1, 0, 0, 0, "authentication agent connection", 1); | |
1660 | c->remote_id = remote_id; | |
1661 | c->force_drain = 1; | |
1662 | } | |
1663 | if (c == NULL) { | |
1664 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1665 | packet_put_int(remote_id); | |
1666 | } else { | |
1667 | /* Send a confirmation to the remote host. */ | |
1668 | debug("Forwarding authentication connection."); | |
1669 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1670 | packet_put_int(remote_id); | |
1671 | packet_put_int(c->self); | |
1672 | } | |
1673 | packet_send(); | |
1674 | } | |
1675 | ||
1676 | static Channel * | |
1677 | client_request_forwarded_tcpip(const char *request_type, int rchan) | |
1678 | { | |
1679 | Channel *c = NULL; | |
1680 | char *listen_address, *originator_address; | |
1681 | int listen_port, originator_port; | |
1682 | int sock; | |
1683 | ||
1684 | /* Get rest of the packet */ | |
1685 | listen_address = packet_get_string(NULL); | |
1686 | listen_port = packet_get_int(); | |
1687 | originator_address = packet_get_string(NULL); | |
1688 | originator_port = packet_get_int(); | |
1689 | packet_check_eom(); | |
1690 | ||
1691 | debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d", | |
1692 | listen_address, listen_port, originator_address, originator_port); | |
1693 | ||
1694 | sock = channel_connect_by_listen_address(listen_port); | |
1695 | if (sock < 0) { | |
1696 | xfree(originator_address); | |
1697 | xfree(listen_address); | |
1698 | return NULL; | |
1699 | } | |
1700 | c = channel_new("forwarded-tcpip", | |
1701 | SSH_CHANNEL_CONNECTING, sock, sock, -1, | |
1702 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, | |
1703 | originator_address, 1); | |
1704 | xfree(originator_address); | |
1705 | xfree(listen_address); | |
1706 | return c; | |
1707 | } | |
1708 | ||
1709 | static Channel * | |
1710 | client_request_x11(const char *request_type, int rchan) | |
1711 | { | |
1712 | Channel *c = NULL; | |
1713 | char *originator; | |
1714 | int originator_port; | |
1715 | int sock; | |
1716 | ||
1717 | if (!options.forward_x11) { | |
1718 | error("Warning: ssh server tried X11 forwarding."); | |
1719 | error("Warning: this is probably a break-in attempt by a malicious server."); | |
1720 | return NULL; | |
1721 | } | |
1722 | originator = packet_get_string(NULL); | |
1723 | if (datafellows & SSH_BUG_X11FWD) { | |
1724 | debug2("buggy server: x11 request w/o originator_port"); | |
1725 | originator_port = 0; | |
1726 | } else { | |
1727 | originator_port = packet_get_int(); | |
1728 | } | |
1729 | packet_check_eom(); | |
1730 | /* XXX check permission */ | |
1731 | debug("client_request_x11: request from %s %d", originator, | |
1732 | originator_port); | |
1733 | xfree(originator); | |
1734 | sock = x11_connect_display(); | |
1735 | if (sock < 0) | |
1736 | return NULL; | |
1737 | c = channel_new("x11", | |
1738 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, | |
1739 | CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); | |
1740 | c->force_drain = 1; | |
1741 | return c; | |
1742 | } | |
1743 | ||
1744 | static Channel * | |
1745 | client_request_agent(const char *request_type, int rchan) | |
1746 | { | |
1747 | Channel *c = NULL; | |
1748 | int sock; | |
1749 | ||
1750 | if (!options.forward_agent) { | |
1751 | error("Warning: ssh server tried agent forwarding."); | |
1752 | error("Warning: this is probably a break-in attempt by a malicious server."); | |
1753 | return NULL; | |
1754 | } | |
1755 | sock = ssh_get_authentication_socket(); | |
1756 | if (sock < 0) | |
1757 | return NULL; | |
1758 | c = channel_new("authentication agent connection", | |
1759 | SSH_CHANNEL_OPEN, sock, sock, -1, | |
1760 | CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, | |
1761 | "authentication agent connection", 1); | |
1762 | c->force_drain = 1; | |
1763 | return c; | |
1764 | } | |
1765 | ||
1766 | /* XXXX move to generic input handler */ | |
1767 | static void | |
1768 | client_input_channel_open(int type, u_int32_t seq, void *ctxt) | |
1769 | { | |
1770 | Channel *c = NULL; | |
1771 | char *ctype; | |
1772 | int rchan; | |
1773 | u_int rmaxpack, rwindow, len; | |
1774 | ||
1775 | ctype = packet_get_string(&len); | |
1776 | rchan = packet_get_int(); | |
1777 | rwindow = packet_get_int(); | |
1778 | rmaxpack = packet_get_int(); | |
1779 | ||
1780 | debug("client_input_channel_open: ctype %s rchan %d win %d max %d", | |
1781 | ctype, rchan, rwindow, rmaxpack); | |
1782 | ||
1783 | if (strcmp(ctype, "forwarded-tcpip") == 0) { | |
1784 | c = client_request_forwarded_tcpip(ctype, rchan); | |
1785 | } else if (strcmp(ctype, "x11") == 0) { | |
1786 | c = client_request_x11(ctype, rchan); | |
1787 | } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { | |
1788 | c = client_request_agent(ctype, rchan); | |
1789 | } | |
1790 | /* XXX duplicate : */ | |
1791 | if (c != NULL) { | |
1792 | debug("confirm %s", ctype); | |
1793 | c->remote_id = rchan; | |
1794 | c->remote_window = rwindow; | |
1795 | c->remote_maxpacket = rmaxpack; | |
1796 | if (c->type != SSH_CHANNEL_CONNECTING) { | |
1797 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1798 | packet_put_int(c->remote_id); | |
1799 | packet_put_int(c->self); | |
1800 | packet_put_int(c->local_window); | |
1801 | packet_put_int(c->local_maxpacket); | |
1802 | packet_send(); | |
1803 | } | |
1804 | } else { | |
1805 | debug("failure %s", ctype); | |
1806 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1807 | packet_put_int(rchan); | |
1808 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
1809 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1810 | packet_put_cstring("open failed"); | |
1811 | packet_put_cstring(""); | |
1812 | } | |
1813 | packet_send(); | |
1814 | } | |
1815 | xfree(ctype); | |
1816 | } | |
1817 | static void | |
1818 | client_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1819 | { | |
1820 | Channel *c = NULL; | |
1821 | int exitval, id, reply, success = 0; | |
1822 | char *rtype; | |
1823 | ||
1824 | id = packet_get_int(); | |
1825 | rtype = packet_get_string(NULL); | |
1826 | reply = packet_get_char(); | |
1827 | ||
1828 | debug("client_input_channel_req: channel %d rtype %s reply %d", | |
1829 | id, rtype, reply); | |
1830 | ||
1831 | if (id == -1) { | |
1832 | error("client_input_channel_req: request for channel -1"); | |
1833 | } else if ((c = channel_lookup(id)) == NULL) { | |
1834 | error("client_input_channel_req: channel %d: unknown channel", id); | |
1835 | } else if (strcmp(rtype, "exit-status") == 0) { | |
1836 | exitval = packet_get_int(); | |
1837 | if (id == session_ident) { | |
1838 | success = 1; | |
1839 | exit_status = exitval; | |
1840 | } else if (c->ctl_fd == -1) { | |
1841 | error("client_input_channel_req: unexpected channel %d", | |
1842 | session_ident); | |
1843 | } else { | |
1844 | atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval)); | |
1845 | success = 1; | |
1846 | } | |
1847 | packet_check_eom(); | |
1848 | } | |
1849 | if (reply) { | |
1850 | packet_start(success ? | |
1851 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1852 | packet_put_int(id); | |
1853 | packet_send(); | |
1854 | } | |
1855 | xfree(rtype); | |
1856 | } | |
1857 | static void | |
1858 | client_input_global_request(int type, u_int32_t seq, void *ctxt) | |
1859 | { | |
1860 | char *rtype; | |
1861 | int want_reply; | |
1862 | int success = 0; | |
1863 | ||
1864 | rtype = packet_get_string(NULL); | |
1865 | want_reply = packet_get_char(); | |
1866 | debug("client_input_global_request: rtype %s want_reply %d", | |
1867 | rtype, want_reply); | |
1868 | if (want_reply) { | |
1869 | packet_start(success ? | |
1870 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1871 | packet_send(); | |
1872 | packet_write_wait(); | |
1873 | } | |
1874 | xfree(rtype); | |
1875 | } | |
1876 | ||
1877 | void | |
1878 | client_session2_setup(int id, int want_tty, int want_subsystem, | |
1879 | const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env, | |
1880 | dispatch_fn *subsys_repl) | |
1881 | { | |
1882 | int len; | |
1883 | Channel *c = NULL; | |
1884 | ||
1885 | debug2("%s: id %d", __func__, id); | |
1886 | ||
1887 | if ((c = channel_lookup(id)) == NULL) | |
1888 | fatal("client_session2_setup: channel %d: unknown channel", id); | |
1889 | ||
1890 | if (want_tty) { | |
1891 | struct winsize ws; | |
1892 | struct termios tio; | |
1893 | ||
1894 | /* Store window size in the packet. */ | |
1895 | if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) | |
1896 | memset(&ws, 0, sizeof(ws)); | |
1897 | ||
1898 | channel_request_start(id, "pty-req", 0); | |
1899 | packet_put_cstring(term != NULL ? term : ""); | |
1900 | packet_put_int((u_int)ws.ws_col); | |
1901 | packet_put_int((u_int)ws.ws_row); | |
1902 | packet_put_int((u_int)ws.ws_xpixel); | |
1903 | packet_put_int((u_int)ws.ws_ypixel); | |
1904 | tio = get_saved_tio(); | |
1905 | tty_make_modes(-1, tiop != NULL ? tiop : &tio); | |
1906 | packet_send(); | |
1907 | /* XXX wait for reply */ | |
1908 | c->client_tty = 1; | |
1909 | } | |
1910 | ||
1911 | /* Transfer any environment variables from client to server */ | |
1912 | if (options.num_send_env != 0 && env != NULL) { | |
1913 | int i, j, matched; | |
1914 | char *name, *val; | |
1915 | ||
1916 | debug("Sending environment."); | |
1917 | for (i = 0; env[i] != NULL; i++) { | |
1918 | /* Split */ | |
1919 | name = xstrdup(env[i]); | |
1920 | if ((val = strchr(name, '=')) == NULL) { | |
1921 | xfree(name); | |
1922 | continue; | |
1923 | } | |
1924 | *val++ = '\0'; | |
1925 | ||
1926 | matched = 0; | |
1927 | for (j = 0; j < options.num_send_env; j++) { | |
1928 | if (match_pattern(name, options.send_env[j])) { | |
1929 | matched = 1; | |
1930 | break; | |
1931 | } | |
1932 | } | |
1933 | if (!matched) { | |
1934 | debug3("Ignored env %s", name); | |
1935 | xfree(name); | |
1936 | continue; | |
1937 | } | |
1938 | ||
1939 | debug("Sending env %s = %s", name, val); | |
1940 | channel_request_start(id, "env", 0); | |
1941 | packet_put_cstring(name); | |
1942 | packet_put_cstring(val); | |
1943 | packet_send(); | |
1944 | xfree(name); | |
1945 | } | |
1946 | } | |
1947 | ||
1948 | len = buffer_len(cmd); | |
1949 | if (len > 0) { | |
1950 | if (len > 900) | |
1951 | len = 900; | |
1952 | if (want_subsystem) { | |
1953 | debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd)); | |
1954 | channel_request_start(id, "subsystem", subsys_repl != NULL); | |
1955 | if (subsys_repl != NULL) { | |
1956 | /* register callback for reply */ | |
1957 | /* XXX we assume that client_loop has already been called */ | |
1958 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl); | |
1959 | dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl); | |
1960 | } | |
1961 | } else { | |
1962 | debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd)); | |
1963 | channel_request_start(id, "exec", 0); | |
1964 | } | |
1965 | packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); | |
1966 | packet_send(); | |
1967 | } else { | |
1968 | channel_request_start(id, "shell", 0); | |
1969 | packet_send(); | |
1970 | } | |
1971 | } | |
1972 | ||
1973 | static void | |
1974 | client_init_dispatch_20(void) | |
1975 | { | |
1976 | dispatch_init(&dispatch_protocol_error); | |
1977 | ||
1978 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1979 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1980 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1981 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1982 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); | |
1983 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1984 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1985 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); | |
1986 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); | |
1987 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); | |
1988 | ||
1989 | /* rekeying */ | |
1990 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
1991 | ||
1992 | /* global request reply messages */ | |
1993 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); | |
1994 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); | |
1995 | } | |
1996 | static void | |
1997 | client_init_dispatch_13(void) | |
1998 | { | |
1999 | dispatch_init(NULL); | |
2000 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
2001 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
2002 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
2003 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
2004 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
2005 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
2006 | dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); | |
2007 | dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); | |
2008 | dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); | |
2009 | ||
2010 | dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? | |
2011 | &client_input_agent_open : &deny_input_open); | |
2012 | dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? | |
2013 | &x11_input_open : &deny_input_open); | |
2014 | } | |
2015 | static void | |
2016 | client_init_dispatch_15(void) | |
2017 | { | |
2018 | client_init_dispatch_13(); | |
2019 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
2020 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); | |
2021 | } | |
2022 | static void | |
2023 | client_init_dispatch(void) | |
2024 | { | |
2025 | if (compat20) | |
2026 | client_init_dispatch_20(); | |
2027 | else if (compat13) | |
2028 | client_init_dispatch_13(); | |
2029 | else | |
2030 | client_init_dispatch_15(); | |
2031 | } | |
2032 | ||
2033 | /* client specific fatal cleanup */ | |
2034 | void | |
2035 | cleanup_exit(int i) | |
2036 | { | |
2037 | leave_raw_mode(); | |
2038 | leave_non_blocking(); | |
2039 | if (options.control_path != NULL && control_fd != -1) | |
2040 | unlink(options.control_path); | |
2041 | _exit(i); | |
2042 | } |