Annotation of src/usr.bin/ssh/clientloop.c, Revision 1.125
1.1 deraadt 1: /*
1.12 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.33 deraadt 5: * The main loop for the interactive session (client side).
1.20 markus 6: *
1.33 deraadt 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.
1.20 markus 35: *
36: *
1.33 deraadt 37: * SSH2 support added by Markus Friedl.
1.78 markus 38: * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
1.20 markus 39: *
1.33 deraadt 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.
1.12 deraadt 59: */
1.1 deraadt 60:
61: #include "includes.h"
1.125 ! djm 62: RCSID("$OpenBSD: clientloop.c,v 1.124 2004/06/14 01:44:38 djm Exp $");
1.1 deraadt 63:
1.45 markus 64: #include "ssh.h"
65: #include "ssh1.h"
66: #include "ssh2.h"
1.1 deraadt 67: #include "xmalloc.h"
68: #include "packet.h"
69: #include "buffer.h"
1.15 markus 70: #include "compat.h"
1.74 markus 71: #include "channels.h"
1.15 markus 72: #include "dispatch.h"
1.30 markus 73: #include "buffer.h"
74: #include "bufaux.h"
1.40 markus 75: #include "key.h"
1.54 markus 76: #include "kex.h"
1.45 markus 77: #include "log.h"
78: #include "readconf.h"
79: #include "clientloop.h"
1.40 markus 80: #include "authfd.h"
1.45 markus 81: #include "atomicio.h"
1.118 deraadt 82: #include "sshpty.h"
1.63 markus 83: #include "misc.h"
1.123 djm 84: #include "monitor_fdpass.h"
85: #include "match.h"
86: #include "msg.h"
1.39 markus 87:
88: /* import options */
89: extern Options options;
90:
1.1 deraadt 91: /* Flag indicating that stdin should be redirected from /dev/null. */
92: extern int stdin_null_flag;
93:
1.116 dtucker 94: /* Flag indicating that no shell has been requested */
95: extern int no_shell_flag;
96:
1.123 djm 97: /* Control socket */
98: extern int control_fd;
99:
1.13 markus 100: /*
101: * Name of the host we are connecting to. This is the name given on the
102: * command line, or the HostName specified for the user-supplied name in a
103: * configuration file.
104: */
1.1 deraadt 105: extern char *host;
106:
1.13 markus 107: /*
108: * Flag to indicate that we have received a window change signal which has
109: * not yet been processed. This will cause a message indicating the new
110: * window size to be sent to the server a little later. This is volatile
111: * because this is updated in a signal handler.
112: */
1.88 markus 113: static volatile sig_atomic_t received_window_change_signal = 0;
114: static volatile sig_atomic_t received_signal = 0;
1.1 deraadt 115:
116: /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
117: static int in_non_blocking_mode = 0;
118:
119: /* Common data for the client loop code. */
1.31 markus 120: static int quit_pending; /* Set to non-zero to quit the client loop. */
121: static int escape_char; /* Escape character. */
1.11 markus 122: static int escape_pending; /* Last character was the escape character */
123: static int last_was_cr; /* Last character was a newline. */
124: static int exit_status; /* Used to store the exit status of the command. */
125: static int stdin_eof; /* EOF has been encountered on standard error. */
126: static Buffer stdin_buffer; /* Buffer for stdin data. */
127: static Buffer stdout_buffer; /* Buffer for stdout data. */
128: static Buffer stderr_buffer; /* Buffer for stderr data. */
1.42 markus 129: static u_long stdin_bytes, stdout_bytes, stderr_bytes;
130: static u_int buffer_high;/* Soft max buffer size. */
1.11 markus 131: static int connection_in; /* Connection to server (input). */
132: static int connection_out; /* Connection to server (output). */
1.56 markus 133: static int need_rekeying; /* Set to non-zero if rekeying is requested. */
1.60 markus 134: static int session_closed = 0; /* In SSH2: login session closed. */
1.117 markus 135: static int server_alive_timeouts = 0;
1.1 deraadt 136:
1.77 itojun 137: static void client_init_dispatch(void);
1.16 markus 138: int session_ident = -1;
139:
1.123 djm 140: struct confirm_ctx {
141: int want_tty;
142: int want_subsys;
143: Buffer cmd;
144: char *term;
145: struct termios tio;
146: };
147:
1.54 markus 148: /*XXX*/
149: extern Kex *xxx_kex;
150:
1.123 djm 151: void ssh_process_session2_setup(int, int, int, Buffer *);
152:
1.1 deraadt 153: /* Restores stdin to blocking mode. */
154:
1.77 itojun 155: static void
1.49 itojun 156: leave_non_blocking(void)
1.1 deraadt 157: {
1.11 markus 158: if (in_non_blocking_mode) {
1.125 ! djm 159: unset_nonblock(fileno(stdin));
1.11 markus 160: in_non_blocking_mode = 0;
161: }
1.1 deraadt 162: }
163:
1.11 markus 164: /* Puts stdin terminal in non-blocking mode. */
165:
1.77 itojun 166: static void
1.49 itojun 167: enter_non_blocking(void)
1.1 deraadt 168: {
1.11 markus 169: in_non_blocking_mode = 1;
1.124 djm 170: set_nonblock(fileno(stdin));
1.1 deraadt 171: }
172:
1.13 markus 173: /*
174: * Signal handler for the window change signal (SIGWINCH). This just sets a
175: * flag indicating that the window has changed.
176: */
1.1 deraadt 177:
1.77 itojun 178: static void
1.11 markus 179: window_change_handler(int sig)
1.1 deraadt 180: {
1.11 markus 181: received_window_change_signal = 1;
182: signal(SIGWINCH, window_change_handler);
1.1 deraadt 183: }
184:
1.13 markus 185: /*
186: * Signal handler for signals that cause the program to terminate. These
187: * signals must be trapped to restore terminal modes.
188: */
1.1 deraadt 189:
1.77 itojun 190: static void
1.11 markus 191: signal_handler(int sig)
1.1 deraadt 192: {
1.75 markus 193: received_signal = sig;
194: quit_pending = 1;
1.1 deraadt 195: }
196:
1.13 markus 197: /*
198: * Returns current time in seconds from Jan 1, 1970 with the maximum
199: * available resolution.
200: */
1.1 deraadt 201:
1.77 itojun 202: static double
1.49 itojun 203: get_current_time(void)
1.1 deraadt 204: {
1.11 markus 205: struct timeval tv;
206: gettimeofday(&tv, NULL);
207: return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
1.1 deraadt 208: }
209:
1.13 markus 210: /*
211: * This is called when the interactive is entered. This checks if there is
212: * an EOF coming on stdin. We must check this explicitly, as select() does
213: * not appear to wake up when redirecting from /dev/null.
214: */
1.1 deraadt 215:
1.77 itojun 216: static void
1.49 itojun 217: client_check_initial_eof_on_stdin(void)
1.1 deraadt 218: {
1.11 markus 219: int len;
220: char buf[1];
1.1 deraadt 221:
1.13 markus 222: /*
223: * If standard input is to be "redirected from /dev/null", we simply
224: * mark that we have seen an EOF and send an EOF message to the
225: * server. Otherwise, we try to read a single character; it appears
226: * that for some files, such /dev/null, select() never wakes up for
227: * read for this descriptor, which means that we never get EOF. This
228: * way we will get the EOF if stdin comes from /dev/null or similar.
229: */
1.11 markus 230: if (stdin_null_flag) {
231: /* Fake EOF on stdin. */
232: debug("Sending eof.");
233: stdin_eof = 1;
234: packet_start(SSH_CMSG_EOF);
235: packet_send();
236: } else {
237: enter_non_blocking();
238:
239: /* Check for immediate EOF on stdin. */
240: len = read(fileno(stdin), buf, 1);
241: if (len == 0) {
1.13 markus 242: /* EOF. Record that we have seen it and send EOF to server. */
1.11 markus 243: debug("Sending eof.");
244: stdin_eof = 1;
245: packet_start(SSH_CMSG_EOF);
246: packet_send();
247: } else if (len > 0) {
1.13 markus 248: /*
249: * Got data. We must store the data in the buffer,
250: * and also process it as an escape character if
251: * appropriate.
252: */
1.42 markus 253: if ((u_char) buf[0] == escape_char)
1.11 markus 254: escape_pending = 1;
1.52 markus 255: else
1.11 markus 256: buffer_append(&stdin_buffer, buf, 1);
257: }
258: leave_non_blocking();
259: }
1.1 deraadt 260: }
261:
262:
1.13 markus 263: /*
264: * Make packets from buffered stdin data, and buffer them for sending to the
265: * connection.
266: */
1.1 deraadt 267:
1.77 itojun 268: static void
1.49 itojun 269: client_make_packets_from_stdin_data(void)
1.1 deraadt 270: {
1.42 markus 271: u_int len;
1.1 deraadt 272:
1.11 markus 273: /* Send buffered stdin data to the server. */
274: while (buffer_len(&stdin_buffer) > 0 &&
1.90 deraadt 275: packet_not_very_much_data_to_write()) {
1.11 markus 276: len = buffer_len(&stdin_buffer);
277: /* Keep the packets at reasonable size. */
278: if (len > packet_get_maxsize())
279: len = packet_get_maxsize();
280: packet_start(SSH_CMSG_STDIN_DATA);
281: packet_put_string(buffer_ptr(&stdin_buffer), len);
282: packet_send();
283: buffer_consume(&stdin_buffer, len);
1.52 markus 284: stdin_bytes += len;
1.11 markus 285: /* If we have a pending EOF, send it now. */
286: if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
287: packet_start(SSH_CMSG_EOF);
288: packet_send();
289: }
1.1 deraadt 290: }
291: }
292:
1.13 markus 293: /*
294: * Checks if the client window has changed, and sends a packet about it to
295: * the server if so. The actual change is detected elsewhere (by a software
296: * interrupt on Unix); this just checks the flag and sends a message if
297: * appropriate.
298: */
1.1 deraadt 299:
1.77 itojun 300: static void
1.49 itojun 301: client_check_window_change(void)
1.1 deraadt 302: {
1.16 markus 303: struct winsize ws;
304:
305: if (! received_window_change_signal)
306: return;
307: /** XXX race */
308: received_window_change_signal = 0;
309:
1.37 markus 310: debug2("client_check_window_change: changed");
1.16 markus 311:
312: if (compat20) {
1.123 djm 313: channel_send_window_changes();
1.16 markus 314: } else {
1.123 djm 315: if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
316: return;
1.16 markus 317: packet_start(SSH_CMSG_WINDOW_SIZE);
318: packet_put_int(ws.ws_row);
319: packet_put_int(ws.ws_col);
320: packet_put_int(ws.ws_xpixel);
321: packet_put_int(ws.ws_ypixel);
322: packet_send();
1.1 deraadt 323: }
324: }
325:
1.117 markus 326: static void
327: client_global_request_reply(int type, u_int32_t seq, void *ctxt)
328: {
329: server_alive_timeouts = 0;
330: client_global_request_reply_fwd(type, seq, ctxt);
331: }
332:
333: static void
334: server_alive_check(void)
335: {
336: if (++server_alive_timeouts > options.server_alive_count_max)
337: packet_disconnect("Timeout, server not responding.");
338: packet_start(SSH2_MSG_GLOBAL_REQUEST);
339: packet_put_cstring("keepalive@openssh.com");
340: packet_put_char(1); /* boolean: want reply */
341: packet_send();
342: }
343:
1.13 markus 344: /*
345: * Waits until the client can do something (some data becomes available on
346: * one of the file descriptors).
347: */
1.77 itojun 348: static void
1.46 markus 349: client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
1.81 markus 350: int *maxfdp, int *nallocp, int rekeying)
1.11 markus 351: {
1.117 markus 352: struct timeval tv, *tvp;
353: int ret;
354:
1.46 markus 355: /* Add any selections by the channel mechanism. */
1.81 markus 356: channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
1.11 markus 357:
1.16 markus 358: if (!compat20) {
1.17 markus 359: /* Read from the connection, unless our buffers are full. */
1.16 markus 360: if (buffer_len(&stdout_buffer) < buffer_high &&
361: buffer_len(&stderr_buffer) < buffer_high &&
362: channel_not_very_much_buffered_data())
1.46 markus 363: FD_SET(connection_in, *readsetp);
1.17 markus 364: /*
365: * Read from stdin, unless we have seen EOF or have very much
366: * buffered data to send to the server.
367: */
368: if (!stdin_eof && packet_not_very_much_data_to_write())
1.46 markus 369: FD_SET(fileno(stdin), *readsetp);
1.17 markus 370:
371: /* Select stdout/stderr if have data in buffer. */
372: if (buffer_len(&stdout_buffer) > 0)
1.46 markus 373: FD_SET(fileno(stdout), *writesetp);
1.17 markus 374: if (buffer_len(&stderr_buffer) > 0)
1.46 markus 375: FD_SET(fileno(stderr), *writesetp);
1.16 markus 376: } else {
1.71 markus 377: /* channel_prepare_select could have closed the last channel */
1.84 markus 378: if (session_closed && !channel_still_open() &&
379: !packet_have_data_to_write()) {
380: /* clear mask since we did not call select() */
1.87 markus 381: memset(*readsetp, 0, *nallocp);
382: memset(*writesetp, 0, *nallocp);
1.84 markus 383: return;
1.71 markus 384: } else {
385: FD_SET(connection_in, *readsetp);
386: }
1.16 markus 387: }
1.11 markus 388:
389: /* Select server connection if have data to write to the server. */
390: if (packet_have_data_to_write())
1.46 markus 391: FD_SET(connection_out, *writesetp);
1.11 markus 392:
1.123 djm 393: if (control_fd != -1)
394: FD_SET(control_fd, *readsetp);
395:
1.13 markus 396: /*
397: * Wait for something to happen. This will suspend the process until
398: * some selected descriptor can be read, written, or has some other
1.117 markus 399: * event pending.
1.13 markus 400: */
1.11 markus 401:
1.117 markus 402: if (options.server_alive_interval == 0 || !compat20)
403: tvp = NULL;
404: else {
405: tv.tv_sec = options.server_alive_interval;
406: tv.tv_usec = 0;
407: tvp = &tv;
408: }
409: ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
410: if (ret < 0) {
1.11 markus 411: char buf[100];
1.51 markus 412:
413: /*
414: * We have to clear the select masks, because we return.
415: * We have to return, because the mainloop checks for the flags
416: * set by the signal handlers.
417: */
1.87 markus 418: memset(*readsetp, 0, *nallocp);
419: memset(*writesetp, 0, *nallocp);
1.50 deraadt 420:
1.11 markus 421: if (errno == EINTR)
422: return;
423: /* Note: we might still have data in the buffers. */
424: snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
425: buffer_append(&stderr_buffer, buf, strlen(buf));
426: quit_pending = 1;
1.117 markus 427: } else if (ret == 0)
428: server_alive_check();
1.11 markus 429: }
430:
1.77 itojun 431: static void
1.31 markus 432: client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
1.1 deraadt 433: {
1.11 markus 434: struct winsize oldws, newws;
435:
436: /* Flush stdout and stderr buffers. */
1.31 markus 437: if (buffer_len(bout) > 0)
1.112 deraadt 438: atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
1.31 markus 439: if (buffer_len(berr) > 0)
1.112 deraadt 440: atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
1.11 markus 441:
442: leave_raw_mode();
443:
1.13 markus 444: /*
445: * Free (and clear) the buffer to reduce the amount of data that gets
446: * written to swap.
447: */
1.31 markus 448: buffer_free(bin);
449: buffer_free(bout);
450: buffer_free(berr);
1.11 markus 451:
452: /* Save old window size. */
453: ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
454:
455: /* Send the suspend signal to the program itself. */
456: kill(getpid(), SIGTSTP);
457:
458: /* Check if the window size has changed. */
459: if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
460: (oldws.ws_row != newws.ws_row ||
1.90 deraadt 461: oldws.ws_col != newws.ws_col ||
462: oldws.ws_xpixel != newws.ws_xpixel ||
463: oldws.ws_ypixel != newws.ws_ypixel))
1.11 markus 464: received_window_change_signal = 1;
465:
466: /* OK, we have been continued by the user. Reinitialize buffers. */
1.31 markus 467: buffer_init(bin);
468: buffer_init(bout);
469: buffer_init(berr);
1.11 markus 470:
471: enter_raw_mode();
472: }
473:
1.77 itojun 474: static void
1.17 markus 475: client_process_net_input(fd_set * readset)
1.11 markus 476: {
1.17 markus 477: int len;
478: char buf[8192];
1.11 markus 479:
1.13 markus 480: /*
481: * Read input from the server, and add any such data to the buffer of
482: * the packet subsystem.
483: */
1.11 markus 484: if (FD_ISSET(connection_in, readset)) {
485: /* Read as much as possible. */
486: len = read(connection_in, buf, sizeof(buf));
487: if (len == 0) {
488: /* Received EOF. The remote host has closed the connection. */
489: snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
490: host);
1.1 deraadt 491: buffer_append(&stderr_buffer, buf, strlen(buf));
492: quit_pending = 1;
493: return;
1.11 markus 494: }
1.13 markus 495: /*
496: * There is a kernel bug on Solaris that causes select to
497: * sometimes wake up even though there is no data available.
498: */
1.53 millert 499: if (len < 0 && (errno == EAGAIN || errno == EINTR))
1.11 markus 500: len = 0;
501:
502: if (len < 0) {
503: /* An error has encountered. Perhaps there is a network problem. */
504: snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
505: host, strerror(errno));
506: buffer_append(&stderr_buffer, buf, strlen(buf));
507: quit_pending = 1;
508: return;
509: }
510: packet_process_incoming(buf, len);
511: }
1.17 markus 512: }
1.16 markus 513:
1.97 jakob 514: static void
1.123 djm 515: client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
516: {
517: int id;
518: Channel *c;
519:
520: id = packet_get_int();
521: packet_check_eom();
522:
523: if ((c = channel_lookup(id)) == NULL) {
524: error("%s: no channel for id %d", __func__, id);
525: return;
526: }
527:
528: if (type == SSH2_MSG_CHANNEL_SUCCESS)
529: debug2("Request suceeded on channel %d", id);
530: else if (type == SSH2_MSG_CHANNEL_FAILURE) {
531: error("Request failed on channel %d", id);
532: channel_free(c);
533: }
534: }
535:
536: static void
537: client_extra_session2_setup(int id, void *arg)
538: {
539: struct confirm_ctx *cctx = arg;
540: Channel *c;
541:
542: if (cctx == NULL)
543: fatal("%s: cctx == NULL", __func__);
544: if ((c = channel_lookup(id)) == NULL)
545: fatal("%s: no channel for id %d", __func__, id);
546:
547: client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
548: cctx->term, &cctx->tio, c->rfd, &cctx->cmd,
549: client_subsystem_reply);
550:
551: c->confirm_ctx = NULL;
552: buffer_free(&cctx->cmd);
553: free(cctx->term);
554: free(cctx);
555: }
556:
557: static void
558: client_process_control(fd_set * readset)
559: {
560: Buffer m;
561: Channel *c;
562: int client_fd, new_fd[3], ver;
563: socklen_t addrlen;
564: struct sockaddr_storage addr;
565: struct confirm_ctx *cctx;
566: char *cmd;
567: u_int len;
568: uid_t euid;
569: gid_t egid;
570:
571: /*
572: * Accept connection on control socket
573: */
574: if (control_fd == -1 || !FD_ISSET(control_fd, readset))
575: return;
576:
577: memset(&addr, 0, sizeof(addr));
578: addrlen = sizeof(addr);
579: if ((client_fd = accept(control_fd,
580: (struct sockaddr*)&addr, &addrlen)) == -1) {
581: error("%s accept: %s", __func__, strerror(errno));
582: return;
583: }
584:
585: if (getpeereid(client_fd, &euid, &egid) < 0) {
586: error("%s getpeereid failed: %s", __func__, strerror(errno));
587: close(client_fd);
588: return;
589: }
590: if ((euid != 0) && (getuid() != euid)) {
591: error("control mode uid mismatch: peer euid %u != uid %u",
592: (u_int) euid, (u_int) getuid());
593: close(client_fd);
594: return;
595: }
596: /* XXX: implement use of ssh-askpass to confirm additional channels */
597:
598: unset_nonblock(client_fd);
599:
600: buffer_init(&m);
601:
602: buffer_put_int(&m, getpid());
603: if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
604: error("%s: client msg_send failed", __func__);
605: close(client_fd);
606: return;
607: }
608: buffer_clear(&m);
609:
610: if (ssh_msg_recv(client_fd, &m) == -1) {
611: error("%s: client msg_recv failed", __func__);
612: close(client_fd);
613: return;
614: }
615:
616: if ((ver = buffer_get_char(&m)) != 0) {
617: error("%s: wrong client version %d", __func__, ver);
618: buffer_free(&m);
619: close(client_fd);
620: return;
621: }
622:
623: cctx = xmalloc(sizeof(*cctx));
624: memset(cctx, 0, sizeof(*cctx));
625:
626: cctx->want_tty = buffer_get_int(&m);
627: cctx->want_subsys = buffer_get_int(&m);
628: cctx->term = buffer_get_string(&m, &len);
629:
630: cmd = buffer_get_string(&m, &len);
631: buffer_init(&cctx->cmd);
632: buffer_append(&cctx->cmd, cmd, strlen(cmd));
633:
634: debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
635: cctx->want_tty, cctx->want_subsys, cmd);
636:
637: /* Gather fds from client */
638: new_fd[0] = mm_receive_fd(client_fd);
639: new_fd[1] = mm_receive_fd(client_fd);
640: new_fd[2] = mm_receive_fd(client_fd);
641:
642: debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
643: new_fd[0], new_fd[1], new_fd[2]);
644:
645: /* Try to pick up ttymodes from client before it goes raw */
646: if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
647: error("%s: tcgetattr: %s", __func__, strerror(errno));
648:
649: buffer_clear(&m);
650: if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
651: error("%s: client msg_send failed", __func__);
652: close(client_fd);
653: close(new_fd[0]);
654: close(new_fd[1]);
655: close(new_fd[2]);
656: return;
657: }
658: buffer_free(&m);
659:
660: /* enable nonblocking unless tty */
661: if (!isatty(new_fd[0]))
662: set_nonblock(new_fd[0]);
663: if (!isatty(new_fd[1]))
664: set_nonblock(new_fd[1]);
665: if (!isatty(new_fd[2]))
666: set_nonblock(new_fd[2]);
667:
668: set_nonblock(client_fd);
669:
670: c = channel_new("session", SSH_CHANNEL_OPENING,
671: new_fd[0], new_fd[1], new_fd[2],
672: CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
673: CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
674:
675: /* XXX */
676: c->ctl_fd = client_fd;
677:
678: debug3("%s: channel_new: %d", __func__, c->self);
679:
680: channel_send_open(c->self);
681: channel_register_confirm(c->self, client_extra_session2_setup, cctx);
682: }
683:
684: static void
1.99 markus 685: process_cmdline(void)
1.97 jakob 686: {
687: void (*handler)(int);
688: char *s, *cmd;
689: u_short fwd_port, fwd_host_port;
690: char buf[1024], sfwd_port[6], sfwd_host_port[6];
1.121 djm 691: int delete = 0;
1.97 jakob 692: int local = 0;
693:
694: leave_raw_mode();
1.101 markus 695: handler = signal(SIGINT, SIG_IGN);
1.99 markus 696: cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
1.97 jakob 697: if (s == NULL)
698: goto out;
699: while (*s && isspace(*s))
700: s++;
1.121 djm 701: if (*s == '-')
702: s++; /* Skip cmdline '-', if any */
1.120 dtucker 703: if (*s == '\0')
1.97 jakob 704: goto out;
1.121 djm 705:
1.122 djm 706: if (*s == 'h' || *s == 'H' || *s == '?') {
1.121 djm 707: logit("Commands:");
708: logit(" -Lport:host:hostport Request local forward");
709: logit(" -Rport:host:hostport Request remote forward");
710: logit(" -KRhostport Cancel remote forward");
711: goto out;
712: }
713:
714: if (*s == 'K') {
715: delete = 1;
716: s++;
717: }
718: if (*s != 'L' && *s != 'R') {
1.109 itojun 719: logit("Invalid command.");
1.97 jakob 720: goto out;
721: }
1.121 djm 722: if (*s == 'L')
1.97 jakob 723: local = 1;
1.121 djm 724: if (local && delete) {
725: logit("Not supported.");
726: goto out;
727: }
728: if ((!local || delete) && !compat20) {
1.109 itojun 729: logit("Not supported for SSH protocol version 1.");
1.97 jakob 730: goto out;
731: }
1.121 djm 732:
733: s++;
1.97 jakob 734: while (*s && isspace(*s))
735: s++;
736:
1.121 djm 737: if (delete) {
738: if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
739: logit("Bad forwarding specification.");
740: goto out;
741: }
742: if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
743: logit("Bad forwarding port(s).");
744: goto out;
745: }
746: channel_request_rforward_cancel(fwd_host_port);
747: } else {
748: if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
749: sfwd_port, buf, sfwd_host_port) != 3 &&
750: sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
751: sfwd_port, buf, sfwd_host_port) != 3) {
752: logit("Bad forwarding specification.");
753: goto out;
754: }
755: if ((fwd_port = a2port(sfwd_port)) == 0 ||
756: (fwd_host_port = a2port(sfwd_host_port)) == 0) {
757: logit("Bad forwarding port(s).");
1.97 jakob 758: goto out;
759: }
1.121 djm 760: if (local) {
761: if (channel_setup_local_fwd_listener(fwd_port, buf,
762: fwd_host_port, options.gateway_ports) < 0) {
763: logit("Port forwarding failed.");
764: goto out;
765: }
766: } else
767: channel_request_remote_forwarding(fwd_port, buf,
768: fwd_host_port);
769: logit("Forwarding port.");
770: }
771:
1.97 jakob 772: out:
773: signal(SIGINT, handler);
774: enter_raw_mode();
775: if (cmd)
776: xfree(cmd);
777: }
778:
1.31 markus 779: /* process the characters one by one */
1.77 itojun 780: static int
1.31 markus 781: process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
782: {
1.32 markus 783: char string[1024];
1.31 markus 784: pid_t pid;
785: int bytes = 0;
1.42 markus 786: u_int i;
787: u_char ch;
1.31 markus 788: char *s;
789:
790: for (i = 0; i < len; i++) {
791: /* Get one character at a time. */
792: ch = buf[i];
793:
794: if (escape_pending) {
795: /* We have previously seen an escape character. */
796: /* Clear the flag now. */
797: escape_pending = 0;
798:
799: /* Process the escaped character. */
800: switch (ch) {
801: case '.':
802: /* Terminate the connection. */
1.32 markus 803: snprintf(string, sizeof string, "%c.\r\n", escape_char);
804: buffer_append(berr, string, strlen(string));
1.31 markus 805:
806: quit_pending = 1;
807: return -1;
808:
809: case 'Z' - 64:
810: /* Suspend the program. */
811: /* Print a message to that effect to the user. */
1.32 markus 812: snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
813: buffer_append(berr, string, strlen(string));
1.31 markus 814:
815: /* Restore terminal modes and suspend. */
816: client_suspend_self(bin, bout, berr);
817:
818: /* We have been continued. */
819: continue;
820:
1.111 markus 821: case 'B':
822: if (compat20) {
823: snprintf(string, sizeof string,
824: "%cB\r\n", escape_char);
825: buffer_append(berr, string,
826: strlen(string));
827: channel_request_start(session_ident,
828: "break", 0);
829: packet_put_int(1000);
830: packet_send();
831: }
832: continue;
833:
1.54 markus 834: case 'R':
1.59 markus 835: if (compat20) {
836: if (datafellows & SSH_BUG_NOREKEY)
1.109 itojun 837: logit("Server does not support re-keying");
1.59 markus 838: else
839: need_rekeying = 1;
840: }
1.54 markus 841: continue;
842:
1.31 markus 843: case '&':
844: /*
845: * Detach the program (continue to serve connections,
846: * but put in background and no more new connections).
847: */
848: /* Restore tty modes. */
849: leave_raw_mode();
850:
851: /* Stop listening for new connections. */
1.86 markus 852: channel_stop_listening();
1.31 markus 853:
1.86 markus 854: snprintf(string, sizeof string,
855: "%c& [backgrounded]\n", escape_char);
856: buffer_append(berr, string, strlen(string));
1.31 markus 857:
858: /* Fork into background. */
859: pid = fork();
860: if (pid < 0) {
861: error("fork: %.100s", strerror(errno));
862: continue;
863: }
864: if (pid != 0) { /* This is the parent. */
865: /* The parent just exits. */
866: exit(0);
867: }
868: /* The child continues serving connections. */
1.86 markus 869: if (compat20) {
870: buffer_append(bin, "\004", 1);
871: /* fake EOF on stdin */
872: return -1;
873: } else if (!stdin_eof) {
874: /*
875: * Sending SSH_CMSG_EOF alone does not always appear
876: * to be enough. So we try to send an EOF character
877: * first.
878: */
879: packet_start(SSH_CMSG_STDIN_DATA);
880: packet_put_string("\004", 1);
881: packet_send();
882: /* Close stdin. */
883: stdin_eof = 1;
884: if (buffer_len(bin) == 0) {
885: packet_start(SSH_CMSG_EOF);
886: packet_send();
887: }
888: }
889: continue;
1.31 markus 890:
891: case '?':
1.32 markus 892: snprintf(string, sizeof string,
1.31 markus 893: "%c?\r\n\
894: Supported escape sequences:\r\n\
1.104 stevesk 895: %c. - terminate connection\r\n\
1.111 markus 896: %cB - send a BREAK to the remote system\r\n\
1.104 stevesk 897: %cC - open a command line\r\n\
898: %cR - Request rekey (SSH protocol 2 only)\r\n\
899: %c^Z - suspend ssh\r\n\
900: %c# - list forwarded connections\r\n\
901: %c& - background ssh (when waiting for connections to terminate)\r\n\
902: %c? - this message\r\n\
903: %c%c - send the escape character by typing it twice\r\n\
1.31 markus 904: (Note that escapes are only recognized immediately after newline.)\r\n",
1.104 stevesk 905: escape_char, escape_char, escape_char, escape_char,
906: escape_char, escape_char, escape_char, escape_char,
1.111 markus 907: escape_char, escape_char, escape_char);
1.32 markus 908: buffer_append(berr, string, strlen(string));
1.31 markus 909: continue;
910:
911: case '#':
1.32 markus 912: snprintf(string, sizeof string, "%c#\r\n", escape_char);
913: buffer_append(berr, string, strlen(string));
1.31 markus 914: s = channel_open_message();
915: buffer_append(berr, s, strlen(s));
916: xfree(s);
1.97 jakob 917: continue;
918:
919: case 'C':
1.99 markus 920: process_cmdline();
1.31 markus 921: continue;
922:
923: default:
924: if (ch != escape_char) {
925: buffer_put_char(bin, escape_char);
926: bytes++;
927: }
928: /* Escaped characters fall through here */
929: break;
930: }
931: } else {
932: /*
933: * The previous character was not an escape char. Check if this
934: * is an escape.
935: */
936: if (last_was_cr && ch == escape_char) {
937: /* It is. Set the flag and continue to next character. */
938: escape_pending = 1;
939: continue;
940: }
941: }
942:
943: /*
944: * Normal character. Record whether it was a newline,
945: * and append it to the buffer.
946: */
947: last_was_cr = (ch == '\r' || ch == '\n');
948: buffer_put_char(bin, ch);
949: bytes++;
950: }
951: return bytes;
952: }
953:
1.77 itojun 954: static void
1.17 markus 955: client_process_input(fd_set * readset)
956: {
1.21 deraadt 957: int len;
1.31 markus 958: char buf[8192];
1.16 markus 959:
1.11 markus 960: /* Read input from stdin. */
961: if (FD_ISSET(fileno(stdin), readset)) {
962: /* Read as much as possible. */
963: len = read(fileno(stdin), buf, sizeof(buf));
1.64 markus 964: if (len < 0 && (errno == EAGAIN || errno == EINTR))
965: return; /* we'll try again later */
1.11 markus 966: if (len <= 0) {
1.13 markus 967: /*
968: * Received EOF or error. They are treated
969: * similarly, except that an error message is printed
970: * if it was an error condition.
971: */
1.11 markus 972: if (len < 0) {
973: snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
974: buffer_append(&stderr_buffer, buf, strlen(buf));
975: }
976: /* Mark that we have seen EOF. */
977: stdin_eof = 1;
1.13 markus 978: /*
979: * Send an EOF message to the server unless there is
980: * data in the buffer. If there is data in the
981: * buffer, no message will be sent now. Code
982: * elsewhere will send the EOF when the buffer
983: * becomes empty if stdin_eof is set.
984: */
1.11 markus 985: if (buffer_len(&stdin_buffer) == 0) {
1.1 deraadt 986: packet_start(SSH_CMSG_EOF);
987: packet_send();
1.11 markus 988: }
1.72 stevesk 989: } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1.13 markus 990: /*
991: * Normal successful read, and no escape character.
992: * Just append the data to buffer.
993: */
1.11 markus 994: buffer_append(&stdin_buffer, buf, len);
995: } else {
1.13 markus 996: /*
997: * Normal, successful read. But we have an escape character
998: * and have to process the characters one by one.
999: */
1.52 markus 1000: if (process_escapes(&stdin_buffer, &stdout_buffer,
1001: &stderr_buffer, buf, len) == -1)
1.31 markus 1002: return;
1.11 markus 1003: }
1004: }
1005: }
1006:
1.77 itojun 1007: static void
1.11 markus 1008: client_process_output(fd_set * writeset)
1009: {
1010: int len;
1011: char buf[100];
1.1 deraadt 1012:
1.11 markus 1013: /* Write buffered output to stdout. */
1014: if (FD_ISSET(fileno(stdout), writeset)) {
1015: /* Write as much data as possible. */
1016: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 1017: buffer_len(&stdout_buffer));
1.11 markus 1018: if (len <= 0) {
1.64 markus 1019: if (errno == EINTR || errno == EAGAIN)
1.11 markus 1020: len = 0;
1021: else {
1.13 markus 1022: /*
1023: * An error or EOF was encountered. Put an
1024: * error message to stderr buffer.
1025: */
1.11 markus 1026: snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1027: buffer_append(&stderr_buffer, buf, strlen(buf));
1028: quit_pending = 1;
1029: return;
1030: }
1031: }
1032: /* Consume printed data from the buffer. */
1033: buffer_consume(&stdout_buffer, len);
1.57 markus 1034: stdout_bytes += len;
1.11 markus 1035: }
1036: /* Write buffered output to stderr. */
1037: if (FD_ISSET(fileno(stderr), writeset)) {
1038: /* Write as much data as possible. */
1039: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 1040: buffer_len(&stderr_buffer));
1.11 markus 1041: if (len <= 0) {
1.64 markus 1042: if (errno == EINTR || errno == EAGAIN)
1.11 markus 1043: len = 0;
1044: else {
1.13 markus 1045: /* EOF or error, but can't even print error message. */
1.11 markus 1046: quit_pending = 1;
1047: return;
1048: }
1049: }
1050: /* Consume printed characters from the buffer. */
1051: buffer_consume(&stderr_buffer, len);
1.57 markus 1052: stderr_bytes += len;
1.11 markus 1053: }
1.1 deraadt 1054: }
1055:
1.13 markus 1056: /*
1.15 markus 1057: * Get packets from the connection input buffer, and process them as long as
1058: * there are packets available.
1059: *
1060: * Any unknown packets received during the actual
1061: * session cause the session to terminate. This is
1062: * intended to make debugging easier since no
1063: * confirmations are sent. Any compatible protocol
1064: * extensions must be negotiated during the
1065: * preparatory phase.
1066: */
1067:
1.77 itojun 1068: static void
1.49 itojun 1069: client_process_buffered_input_packets(void)
1.15 markus 1070: {
1.54 markus 1071: dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1.15 markus 1072: }
1073:
1.31 markus 1074: /* scan buf[] for '~' before sending data to the peer */
1.30 markus 1075:
1.77 itojun 1076: static int
1.31 markus 1077: simple_escape_filter(Channel *c, char *buf, int len)
1.30 markus 1078: {
1.31 markus 1079: /* XXX we assume c->extended is writeable */
1080: return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1.30 markus 1081: }
1082:
1.77 itojun 1083: static void
1.60 markus 1084: client_channel_closed(int id, void *arg)
1085: {
1.83 markus 1086: channel_cancel_cleanup(id);
1.60 markus 1087: session_closed = 1;
1.113 markus 1088: leave_raw_mode();
1.60 markus 1089: }
1090:
1.15 markus 1091: /*
1.13 markus 1092: * Implements the interactive session with the server. This is called after
1093: * the user has been authenticated, and a command has been started on the
1.72 stevesk 1094: * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1095: * used as an escape character for terminating or suspending the session.
1.13 markus 1096: */
1.1 deraadt 1097:
1.20 markus 1098: int
1.30 markus 1099: client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1.1 deraadt 1100: {
1.46 markus 1101: fd_set *readset = NULL, *writeset = NULL;
1.11 markus 1102: double start_time, total_time;
1.81 markus 1103: int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
1.11 markus 1104: char buf[100];
1105:
1106: debug("Entering interactive session.");
1107:
1108: start_time = get_current_time();
1109:
1110: /* Initialize variables. */
1111: escape_pending = 0;
1112: last_was_cr = 1;
1113: exit_status = -1;
1114: stdin_eof = 0;
1115: buffer_high = 64 * 1024;
1116: connection_in = packet_get_connection_in();
1117: connection_out = packet_get_connection_out();
1.46 markus 1118: max_fd = MAX(connection_in, connection_out);
1.123 djm 1119: if (control_fd != -1)
1120: max_fd = MAX(max_fd, control_fd);
1.46 markus 1121:
1122: if (!compat20) {
1.63 markus 1123: /* enable nonblocking unless tty */
1124: if (!isatty(fileno(stdin)))
1125: set_nonblock(fileno(stdin));
1126: if (!isatty(fileno(stdout)))
1127: set_nonblock(fileno(stdout));
1128: if (!isatty(fileno(stderr)))
1129: set_nonblock(fileno(stderr));
1.46 markus 1130: max_fd = MAX(max_fd, fileno(stdin));
1131: max_fd = MAX(max_fd, fileno(stdout));
1132: max_fd = MAX(max_fd, fileno(stderr));
1133: }
1.11 markus 1134: stdin_bytes = 0;
1135: stdout_bytes = 0;
1136: stderr_bytes = 0;
1137: quit_pending = 0;
1138: escape_char = escape_char_arg;
1139:
1140: /* Initialize buffers. */
1141: buffer_init(&stdin_buffer);
1142: buffer_init(&stdout_buffer);
1143: buffer_init(&stderr_buffer);
1144:
1.15 markus 1145: client_init_dispatch();
1146:
1.105 markus 1147: /*
1148: * Set signal handlers, (e.g. to restore non-blocking mode)
1149: * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1150: */
1151: if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1152: signal(SIGINT, signal_handler);
1153: if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1154: signal(SIGQUIT, signal_handler);
1155: if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1156: signal(SIGTERM, signal_handler);
1.11 markus 1157: if (have_pty)
1158: signal(SIGWINCH, window_change_handler);
1159:
1160: if (have_pty)
1161: enter_raw_mode();
1162:
1.48 markus 1163: if (compat20) {
1164: session_ident = ssh2_chan_id;
1.72 stevesk 1165: if (escape_char != SSH_ESCAPECHAR_NONE)
1.48 markus 1166: channel_register_filter(session_ident,
1167: simple_escape_filter);
1.60 markus 1168: if (session_ident != -1)
1169: channel_register_cleanup(session_ident,
1170: client_channel_closed);
1.48 markus 1171: } else {
1172: /* Check if we should immediately send eof on stdin. */
1.16 markus 1173: client_check_initial_eof_on_stdin();
1.48 markus 1174: }
1.30 markus 1175:
1.11 markus 1176: /* Main loop of the client for the interactive session mode. */
1177: while (!quit_pending) {
1178:
1.13 markus 1179: /* Process buffered packets sent by the server. */
1.11 markus 1180: client_process_buffered_input_packets();
1181:
1.60 markus 1182: if (compat20 && session_closed && !channel_still_open())
1183: break;
1184:
1.56 markus 1185: rekeying = (xxx_kex != NULL && !xxx_kex->done);
1.16 markus 1186:
1.56 markus 1187: if (rekeying) {
1188: debug("rekeying in progress");
1189: } else {
1190: /*
1191: * Make packets of buffered stdin data, and buffer
1192: * them for sending to the server.
1193: */
1194: if (!compat20)
1195: client_make_packets_from_stdin_data();
1.11 markus 1196:
1.56 markus 1197: /*
1198: * Make packets from buffered channel data, and
1199: * enqueue them for sending to the server.
1200: */
1201: if (packet_not_very_much_data_to_write())
1202: channel_output_poll();
1.11 markus 1203:
1.56 markus 1204: /*
1205: * Check if the window size has changed, and buffer a
1206: * message about it to the server if so.
1207: */
1208: client_check_window_change();
1.11 markus 1209:
1.56 markus 1210: if (quit_pending)
1211: break;
1212: }
1.13 markus 1213: /*
1214: * Wait until we have something to do (something becomes
1215: * available on one of the descriptors).
1216: */
1.81 markus 1217: max_fd2 = max_fd;
1.56 markus 1218: client_wait_until_can_do_something(&readset, &writeset,
1.81 markus 1219: &max_fd2, &nalloc, rekeying);
1.11 markus 1220:
1221: if (quit_pending)
1222: break;
1223:
1.56 markus 1224: /* Do channel operations unless rekeying in progress. */
1225: if (!rekeying) {
1226: channel_after_select(readset, writeset);
1.108 markus 1227: if (need_rekeying || packet_need_rekeying()) {
1228: debug("need rekeying");
1.56 markus 1229: xxx_kex->done = 0;
1230: kex_send_kexinit(xxx_kex);
1231: need_rekeying = 0;
1232: }
1233: }
1.11 markus 1234:
1.17 markus 1235: /* Buffer input from the connection. */
1.46 markus 1236: client_process_net_input(readset);
1.17 markus 1237:
1.123 djm 1238: /* Accept control connections. */
1239: client_process_control(readset);
1240:
1.17 markus 1241: if (quit_pending)
1242: break;
1.11 markus 1243:
1.17 markus 1244: if (!compat20) {
1245: /* Buffer data from stdin */
1.46 markus 1246: client_process_input(readset);
1.17 markus 1247: /*
1248: * Process output to stdout and stderr. Output to
1249: * the connection is processed elsewhere (above).
1250: */
1.46 markus 1251: client_process_output(writeset);
1.17 markus 1252: }
1.11 markus 1253:
1.13 markus 1254: /* Send as much buffered packet data as possible to the sender. */
1.46 markus 1255: if (FD_ISSET(connection_out, writeset))
1.11 markus 1256: packet_write_poll();
1257: }
1.46 markus 1258: if (readset)
1259: xfree(readset);
1260: if (writeset)
1261: xfree(writeset);
1.11 markus 1262:
1263: /* Terminate the session. */
1264:
1265: /* Stop watching for window change. */
1266: if (have_pty)
1267: signal(SIGWINCH, SIG_DFL);
1268:
1.76 markus 1269: channel_free_all();
1.11 markus 1270:
1.75 markus 1271: if (have_pty)
1272: leave_raw_mode();
1273:
1274: /* restore blocking io */
1275: if (!isatty(fileno(stdin)))
1276: unset_nonblock(fileno(stdin));
1277: if (!isatty(fileno(stdout)))
1278: unset_nonblock(fileno(stdout));
1279: if (!isatty(fileno(stderr)))
1280: unset_nonblock(fileno(stderr));
1.116 dtucker 1281:
1282: /*
1283: * If there was no shell or command requested, there will be no remote
1284: * exit status to be returned. In that case, clear error code if the
1285: * connection was deliberately terminated at this end.
1286: */
1287: if (no_shell_flag && received_signal == SIGTERM) {
1288: received_signal = 0;
1289: exit_status = 0;
1290: }
1.75 markus 1291:
1.113 markus 1292: if (received_signal)
1.89 itojun 1293: fatal("Killed by signal %d.", (int) received_signal);
1.75 markus 1294:
1.13 markus 1295: /*
1296: * In interactive mode (with pseudo tty) display a message indicating
1297: * that the connection has been closed.
1298: */
1.11 markus 1299: if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1300: snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1301: buffer_append(&stderr_buffer, buf, strlen(buf));
1302: }
1.70 markus 1303:
1.11 markus 1304: /* Output any buffered data for stdout. */
1.70 markus 1305: while (buffer_len(&stdout_buffer) > 0) {
1306: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 1307: buffer_len(&stdout_buffer));
1.70 markus 1308: if (len <= 0) {
1.11 markus 1309: error("Write failed flushing stdout buffer.");
1.70 markus 1310: break;
1311: }
1.11 markus 1312: buffer_consume(&stdout_buffer, len);
1.57 markus 1313: stdout_bytes += len;
1.11 markus 1314: }
1315:
1316: /* Output any buffered data for stderr. */
1.70 markus 1317: while (buffer_len(&stderr_buffer) > 0) {
1318: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 1319: buffer_len(&stderr_buffer));
1.70 markus 1320: if (len <= 0) {
1.11 markus 1321: error("Write failed flushing stderr buffer.");
1.70 markus 1322: break;
1323: }
1.11 markus 1324: buffer_consume(&stderr_buffer, len);
1.57 markus 1325: stderr_bytes += len;
1.11 markus 1326: }
1327:
1328: /* Clear and free any buffers. */
1329: memset(buf, 0, sizeof(buf));
1330: buffer_free(&stdin_buffer);
1331: buffer_free(&stdout_buffer);
1332: buffer_free(&stderr_buffer);
1333:
1334: /* Report bytes transferred, and transfer rates. */
1335: total_time = get_current_time() - start_time;
1336: debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1.90 deraadt 1337: stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1.11 markus 1338: if (total_time > 0)
1339: debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1.90 deraadt 1340: stdin_bytes / total_time, stdout_bytes / total_time,
1341: stderr_bytes / total_time);
1.11 markus 1342:
1343: /* Return the exit status of the program. */
1344: debug("Exit status %d", exit_status);
1345: return exit_status;
1.15 markus 1346: }
1347:
1348: /*********/
1349:
1.77 itojun 1350: static void
1.94 markus 1351: client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1.15 markus 1352: {
1.42 markus 1353: u_int data_len;
1.15 markus 1354: char *data = packet_get_string(&data_len);
1.93 markus 1355: packet_check_eom();
1.15 markus 1356: buffer_append(&stdout_buffer, data, data_len);
1357: memset(data, 0, data_len);
1358: xfree(data);
1359: }
1.77 itojun 1360: static void
1.94 markus 1361: client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1.15 markus 1362: {
1.42 markus 1363: u_int data_len;
1.15 markus 1364: char *data = packet_get_string(&data_len);
1.93 markus 1365: packet_check_eom();
1.15 markus 1366: buffer_append(&stderr_buffer, data, data_len);
1367: memset(data, 0, data_len);
1368: xfree(data);
1369: }
1.77 itojun 1370: static void
1.94 markus 1371: client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1.15 markus 1372: {
1373: exit_status = packet_get_int();
1.93 markus 1374: packet_check_eom();
1.15 markus 1375: /* Acknowledge the exit. */
1376: packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1377: packet_send();
1378: /*
1379: * Must wait for packet to be sent since we are
1380: * exiting the loop.
1381: */
1382: packet_write_wait();
1383: /* Flag that we want to exit. */
1384: quit_pending = 1;
1385: }
1.115 markus 1386: static void
1387: client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1388: {
1389: Channel *c = NULL;
1390: int remote_id, sock;
1391:
1392: /* Read the remote channel number from the message. */
1393: remote_id = packet_get_int();
1394: packet_check_eom();
1395:
1396: /*
1397: * Get a connection to the local authentication agent (this may again
1398: * get forwarded).
1399: */
1400: sock = ssh_get_authentication_socket();
1401:
1402: /*
1403: * If we could not connect the agent, send an error message back to
1404: * the server. This should never happen unless the agent dies,
1405: * because authentication forwarding is only enabled if we have an
1406: * agent.
1407: */
1408: if (sock >= 0) {
1409: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1410: -1, 0, 0, 0, "authentication agent connection", 1);
1411: c->remote_id = remote_id;
1412: c->force_drain = 1;
1413: }
1414: if (c == NULL) {
1415: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1416: packet_put_int(remote_id);
1417: } else {
1418: /* Send a confirmation to the remote host. */
1419: debug("Forwarding authentication connection.");
1420: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1421: packet_put_int(remote_id);
1422: packet_put_int(c->self);
1423: }
1424: packet_send();
1425: }
1.15 markus 1426:
1.77 itojun 1427: static Channel *
1.40 markus 1428: client_request_forwarded_tcpip(const char *request_type, int rchan)
1429: {
1.103 deraadt 1430: Channel *c = NULL;
1.40 markus 1431: char *listen_address, *originator_address;
1432: int listen_port, originator_port;
1.67 markus 1433: int sock;
1.40 markus 1434:
1435: /* Get rest of the packet */
1436: listen_address = packet_get_string(NULL);
1437: listen_port = packet_get_int();
1438: originator_address = packet_get_string(NULL);
1439: originator_port = packet_get_int();
1.93 markus 1440: packet_check_eom();
1.40 markus 1441:
1442: debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1443: listen_address, listen_port, originator_address, originator_port);
1444:
1.80 stevesk 1445: sock = channel_connect_by_listen_address(listen_port);
1.67 markus 1446: if (sock < 0) {
1447: xfree(originator_address);
1448: xfree(listen_address);
1449: return NULL;
1450: }
1451: c = channel_new("forwarded-tcpip",
1452: SSH_CHANNEL_CONNECTING, sock, sock, -1,
1453: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1.110 markus 1454: originator_address, 1);
1.40 markus 1455: xfree(originator_address);
1456: xfree(listen_address);
1457: return c;
1458: }
1459:
1.103 deraadt 1460: static Channel *
1.40 markus 1461: client_request_x11(const char *request_type, int rchan)
1462: {
1463: Channel *c = NULL;
1464: char *originator;
1465: int originator_port;
1.67 markus 1466: int sock;
1.40 markus 1467:
1468: if (!options.forward_x11) {
1469: error("Warning: ssh server tried X11 forwarding.");
1470: error("Warning: this is probably a break in attempt by a malicious server.");
1471: return NULL;
1472: }
1473: originator = packet_get_string(NULL);
1474: if (datafellows & SSH_BUG_X11FWD) {
1475: debug2("buggy server: x11 request w/o originator_port");
1476: originator_port = 0;
1477: } else {
1478: originator_port = packet_get_int();
1479: }
1.93 markus 1480: packet_check_eom();
1.40 markus 1481: /* XXX check permission */
1.47 markus 1482: debug("client_request_x11: request from %s %d", originator,
1483: originator_port);
1.67 markus 1484: xfree(originator);
1.40 markus 1485: sock = x11_connect_display();
1.67 markus 1486: if (sock < 0)
1487: return NULL;
1488: c = channel_new("x11",
1489: SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1.110 markus 1490: CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1.82 markus 1491: c->force_drain = 1;
1.40 markus 1492: return c;
1493: }
1494:
1.103 deraadt 1495: static Channel *
1.40 markus 1496: client_request_agent(const char *request_type, int rchan)
1497: {
1498: Channel *c = NULL;
1.67 markus 1499: int sock;
1.40 markus 1500:
1501: if (!options.forward_agent) {
1502: error("Warning: ssh server tried agent forwarding.");
1503: error("Warning: this is probably a break in attempt by a malicious server.");
1504: return NULL;
1505: }
1506: sock = ssh_get_authentication_socket();
1.67 markus 1507: if (sock < 0)
1508: return NULL;
1509: c = channel_new("authentication agent connection",
1510: SSH_CHANNEL_OPEN, sock, sock, -1,
1511: CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1.110 markus 1512: "authentication agent connection", 1);
1.82 markus 1513: c->force_drain = 1;
1.40 markus 1514: return c;
1515: }
1516:
1.22 markus 1517: /* XXXX move to generic input handler */
1.77 itojun 1518: static void
1.94 markus 1519: client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1.22 markus 1520: {
1521: Channel *c = NULL;
1522: char *ctype;
1523: int rchan;
1.102 markus 1524: u_int rmaxpack, rwindow, len;
1.22 markus 1525:
1526: ctype = packet_get_string(&len);
1527: rchan = packet_get_int();
1528: rwindow = packet_get_int();
1529: rmaxpack = packet_get_int();
1530:
1.24 markus 1531: debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1.22 markus 1532: ctype, rchan, rwindow, rmaxpack);
1533:
1.40 markus 1534: if (strcmp(ctype, "forwarded-tcpip") == 0) {
1535: c = client_request_forwarded_tcpip(ctype, rchan);
1536: } else if (strcmp(ctype, "x11") == 0) {
1537: c = client_request_x11(ctype, rchan);
1538: } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1539: c = client_request_agent(ctype, rchan);
1.22 markus 1540: }
1541: /* XXX duplicate : */
1542: if (c != NULL) {
1543: debug("confirm %s", ctype);
1544: c->remote_id = rchan;
1545: c->remote_window = rwindow;
1546: c->remote_maxpacket = rmaxpack;
1.69 markus 1547: if (c->type != SSH_CHANNEL_CONNECTING) {
1548: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1549: packet_put_int(c->remote_id);
1550: packet_put_int(c->self);
1551: packet_put_int(c->local_window);
1552: packet_put_int(c->local_maxpacket);
1553: packet_send();
1554: }
1.22 markus 1555: } else {
1556: debug("failure %s", ctype);
1557: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1558: packet_put_int(rchan);
1559: packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1.66 markus 1560: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.69 markus 1561: packet_put_cstring("open failed");
1.66 markus 1562: packet_put_cstring("");
1563: }
1.22 markus 1564: packet_send();
1565: }
1566: xfree(ctype);
1567: }
1.77 itojun 1568: static void
1.94 markus 1569: client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1.48 markus 1570: {
1571: Channel *c = NULL;
1.123 djm 1572: int exitval, id, reply, success = 0;
1.48 markus 1573: char *rtype;
1574:
1575: id = packet_get_int();
1576: rtype = packet_get_string(NULL);
1577: reply = packet_get_char();
1578:
1579: debug("client_input_channel_req: channel %d rtype %s reply %d",
1580: id, rtype, reply);
1581:
1582: c = channel_lookup(id);
1583: if (c == NULL) {
1584: error("client_input_channel_req: channel %d: unknown channel", id);
1585: } else if (strcmp(rtype, "exit-status") == 0) {
1.123 djm 1586: exitval = packet_get_int();
1587: if (id == session_ident) {
1588: success = 1;
1589: exit_status = exitval;
1590: } else if (c->ctl_fd == -1) {
1591: error("client_input_channel_req: unexpected channel %d",
1592: session_ident);
1593: } else {
1594: atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1595: success = 1;
1596: }
1.93 markus 1597: packet_check_eom();
1.48 markus 1598: }
1599: if (reply) {
1600: packet_start(success ?
1601: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1602: packet_put_int(c->remote_id);
1603: packet_send();
1604: }
1605: xfree(rtype);
1606: }
1.95 markus 1607: static void
1608: client_input_global_request(int type, u_int32_t seq, void *ctxt)
1609: {
1610: char *rtype;
1611: int want_reply;
1612: int success = 0;
1613:
1614: rtype = packet_get_string(NULL);
1615: want_reply = packet_get_char();
1.117 markus 1616: debug("client_input_global_request: rtype %s want_reply %d",
1617: rtype, want_reply);
1.95 markus 1618: if (want_reply) {
1619: packet_start(success ?
1620: SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1621: packet_send();
1622: packet_write_wait();
1623: }
1624: xfree(rtype);
1625: }
1.22 markus 1626:
1.123 djm 1627: void
1628: client_session2_setup(int id, int want_tty, int want_subsystem,
1629: const char *term, struct termios *tiop, int in_fd, Buffer *cmd,
1630: dispatch_fn *subsys_repl)
1631: {
1632: int len;
1633:
1634: debug2("%s: id %d", __func__, id);
1635:
1636: if (want_tty) {
1637: struct winsize ws;
1638: struct termios tio;
1639:
1640: /* Store window size in the packet. */
1641: if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1642: memset(&ws, 0, sizeof(ws));
1643:
1644: channel_request_start(id, "pty-req", 0);
1645: packet_put_cstring(term != NULL ? term : "");
1646: packet_put_int(ws.ws_col);
1647: packet_put_int(ws.ws_row);
1648: packet_put_int(ws.ws_xpixel);
1649: packet_put_int(ws.ws_ypixel);
1650: tio = get_saved_tio();
1651: tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1652: packet_send();
1653: /* XXX wait for reply */
1654: }
1655:
1656: /* Transfer any environment variables from client to server */
1657: if (options.num_send_env != 0) {
1658: int i, j, matched;
1659: extern char **environ;
1660: char *name, *val;
1661:
1662: debug("Sending environment.");
1663: for (i = 0; environ && environ[i] != NULL; i++) {
1664: /* Split */
1665: name = xstrdup(environ[i]);
1666: if ((val = strchr(name, '=')) == NULL) {
1667: free(name);
1668: continue;
1669: }
1670: *val++ = '\0';
1671:
1672: matched = 0;
1673: for (j = 0; j < options.num_send_env; j++) {
1674: if (match_pattern(name, options.send_env[j])) {
1675: matched = 1;
1676: break;
1677: }
1678: }
1679: if (!matched) {
1680: debug3("Ignored env %s", name);
1681: free(name);
1682: continue;
1683: }
1684:
1685: debug("Sending env %s = %s", name, val);
1686: channel_request_start(id, "env", 0);
1687: packet_put_cstring(name);
1688: packet_put_cstring(val);
1689: packet_send();
1690: free(name);
1691: }
1692: }
1693:
1694: len = buffer_len(cmd);
1695: if (len > 0) {
1696: if (len > 900)
1697: len = 900;
1698: if (want_subsystem) {
1699: debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
1700: channel_request_start(id, "subsystem", subsys_repl != NULL);
1701: if (subsys_repl != NULL) {
1702: /* register callback for reply */
1703: /* XXX we assume that client_loop has already been called */
1704: dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
1705: dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
1706: }
1707: } else {
1708: debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
1709: channel_request_start(id, "exec", 0);
1710: }
1711: packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1712: packet_send();
1713: } else {
1714: channel_request_start(id, "shell", 0);
1715: packet_send();
1716: }
1717: }
1718:
1.77 itojun 1719: static void
1.49 itojun 1720: client_init_dispatch_20(void)
1.16 markus 1721: {
1.55 markus 1722: dispatch_init(&dispatch_protocol_error);
1.100 markus 1723:
1.16 markus 1724: dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1725: dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1726: dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1727: dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1.22 markus 1728: dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1.16 markus 1729: dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1730: dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1.48 markus 1731: dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1.16 markus 1732: dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1.95 markus 1733: dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1.55 markus 1734:
1735: /* rekeying */
1736: dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1.100 markus 1737:
1738: /* global request reply messages */
1739: dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1740: dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1.16 markus 1741: }
1.77 itojun 1742: static void
1.49 itojun 1743: client_init_dispatch_13(void)
1.15 markus 1744: {
1745: dispatch_init(NULL);
1746: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1747: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1748: dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1749: dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1750: dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1751: dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1752: dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1753: dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1754: dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1.39 markus 1755:
1756: dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1.115 markus 1757: &client_input_agent_open : &deny_input_open);
1.39 markus 1758: dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1759: &x11_input_open : &deny_input_open);
1.15 markus 1760: }
1.77 itojun 1761: static void
1.49 itojun 1762: client_init_dispatch_15(void)
1.15 markus 1763: {
1764: client_init_dispatch_13();
1765: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1766: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1767: }
1.79 stevesk 1768: static void
1.49 itojun 1769: client_init_dispatch(void)
1.15 markus 1770: {
1.16 markus 1771: if (compat20)
1772: client_init_dispatch_20();
1773: else if (compat13)
1.15 markus 1774: client_init_dispatch_13();
1775: else
1776: client_init_dispatch_15();
1.113 markus 1777: }
1778:
1779: /* client specific fatal cleanup */
1780: void
1.114 markus 1781: cleanup_exit(int i)
1.113 markus 1782: {
1783: leave_raw_mode();
1784: leave_non_blocking();
1.123 djm 1785: if (options.control_path != NULL && control_fd != -1)
1786: unlink(options.control_path);
1.114 markus 1787: _exit(i);
1.1 deraadt 1788: }
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