Annotation of src/usr.bin/ssh/clientloop.c, Revision 1.23
1.1 deraadt 1: /*
1.20 markus 2: *
1.12 deraadt 3: * clientloop.c
1.20 markus 4: *
1.12 deraadt 5: * Author: Tatu Ylonen <ylo@cs.hut.fi>
1.20 markus 6: *
1.12 deraadt 7: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8: * All rights reserved
1.20 markus 9: *
10: *
1.12 deraadt 11: * Created: Sat Sep 23 12:23:57 1995 ylo
1.20 markus 12: *
1.12 deraadt 13: * The main loop for the interactive session (client side).
1.20 markus 14: *
1.16 markus 15: * SSH2 support added by Markus Friedl.
1.12 deraadt 16: */
1.1 deraadt 17:
18: #include "includes.h"
1.23 ! markus 19: RCSID("$Id: clientloop.c,v 1.22 2000/04/28 08:10:20 markus Exp $");
1.1 deraadt 20:
21: #include "xmalloc.h"
22: #include "ssh.h"
23: #include "packet.h"
24: #include "buffer.h"
25: #include "authfd.h"
1.8 markus 26: #include "readconf.h"
1.1 deraadt 27:
1.16 markus 28: #include "ssh2.h"
1.15 markus 29: #include "compat.h"
30: #include "channels.h"
31: #include "dispatch.h"
32:
33:
1.1 deraadt 34: /* Flag indicating that stdin should be redirected from /dev/null. */
35: extern int stdin_null_flag;
36:
1.13 markus 37: /*
38: * Name of the host we are connecting to. This is the name given on the
39: * command line, or the HostName specified for the user-supplied name in a
40: * configuration file.
41: */
1.1 deraadt 42: extern char *host;
43:
1.13 markus 44: /*
45: * Flag to indicate that we have received a window change signal which has
46: * not yet been processed. This will cause a message indicating the new
47: * window size to be sent to the server a little later. This is volatile
48: * because this is updated in a signal handler.
49: */
1.1 deraadt 50: static volatile int received_window_change_signal = 0;
51:
52: /* Terminal modes, as saved by enter_raw_mode. */
53: static struct termios saved_tio;
54:
1.13 markus 55: /*
56: * Flag indicating whether we are in raw mode. This is used by
57: * enter_raw_mode and leave_raw_mode.
58: */
1.1 deraadt 59: static int in_raw_mode = 0;
60:
61: /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
62: static int in_non_blocking_mode = 0;
63:
64: /* Common data for the client loop code. */
1.11 markus 65: static int escape_pending; /* Last character was the escape character */
66: static int last_was_cr; /* Last character was a newline. */
67: static int exit_status; /* Used to store the exit status of the command. */
68: static int stdin_eof; /* EOF has been encountered on standard error. */
69: static Buffer stdin_buffer; /* Buffer for stdin data. */
70: static Buffer stdout_buffer; /* Buffer for stdout data. */
71: static Buffer stderr_buffer; /* Buffer for stderr data. */
72: static unsigned int buffer_high;/* Soft max buffer size. */
73: static int max_fd; /* Maximum file descriptor number in select(). */
74: static int connection_in; /* Connection to server (input). */
75: static int connection_out; /* Connection to server (output). */
1.1 deraadt 76: static unsigned long stdin_bytes, stdout_bytes, stderr_bytes;
1.11 markus 77: static int quit_pending; /* Set to non-zero to quit the client loop. */
78: static int escape_char; /* Escape character. */
1.1 deraadt 79:
1.16 markus 80:
81: void client_init_dispatch(void);
82: int session_ident = -1;
83:
1.13 markus 84: /* Returns the user\'s terminal to normal mode if it had been put in raw mode. */
1.1 deraadt 85:
1.20 markus 86: void
1.11 markus 87: leave_raw_mode()
1.1 deraadt 88: {
1.11 markus 89: if (!in_raw_mode)
90: return;
91: in_raw_mode = 0;
92: if (tcsetattr(fileno(stdin), TCSADRAIN, &saved_tio) < 0)
93: perror("tcsetattr");
1.1 deraadt 94:
1.11 markus 95: fatal_remove_cleanup((void (*) (void *)) leave_raw_mode, NULL);
1.1 deraadt 96: }
97:
98: /* Puts the user\'s terminal in raw mode. */
99:
1.20 markus 100: void
1.11 markus 101: enter_raw_mode()
1.1 deraadt 102: {
1.11 markus 103: struct termios tio;
1.1 deraadt 104:
1.11 markus 105: if (tcgetattr(fileno(stdin), &tio) < 0)
106: perror("tcgetattr");
107: saved_tio = tio;
108: tio.c_iflag |= IGNPAR;
109: tio.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
110: tio.c_lflag &= ~(ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
1.1 deraadt 111: #ifdef IEXTEN
1.11 markus 112: tio.c_lflag &= ~IEXTEN;
113: #endif /* IEXTEN */
114: tio.c_oflag &= ~OPOST;
115: tio.c_cc[VMIN] = 1;
116: tio.c_cc[VTIME] = 0;
117: if (tcsetattr(fileno(stdin), TCSADRAIN, &tio) < 0)
118: perror("tcsetattr");
119: in_raw_mode = 1;
1.1 deraadt 120:
1.11 markus 121: fatal_add_cleanup((void (*) (void *)) leave_raw_mode, NULL);
122: }
1.1 deraadt 123:
124: /* Restores stdin to blocking mode. */
125:
1.20 markus 126: void
1.11 markus 127: leave_non_blocking()
1.1 deraadt 128: {
1.11 markus 129: if (in_non_blocking_mode) {
130: (void) fcntl(fileno(stdin), F_SETFL, 0);
131: in_non_blocking_mode = 0;
132: fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
133: }
1.1 deraadt 134: }
135:
1.11 markus 136: /* Puts stdin terminal in non-blocking mode. */
137:
1.20 markus 138: void
1.11 markus 139: enter_non_blocking()
1.1 deraadt 140: {
1.11 markus 141: in_non_blocking_mode = 1;
142: (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
143: fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
1.1 deraadt 144: }
145:
1.13 markus 146: /*
147: * Signal handler for the window change signal (SIGWINCH). This just sets a
148: * flag indicating that the window has changed.
149: */
1.1 deraadt 150:
1.20 markus 151: void
1.11 markus 152: window_change_handler(int sig)
1.1 deraadt 153: {
1.11 markus 154: received_window_change_signal = 1;
155: signal(SIGWINCH, window_change_handler);
1.1 deraadt 156: }
157:
1.13 markus 158: /*
159: * Signal handler for signals that cause the program to terminate. These
160: * signals must be trapped to restore terminal modes.
161: */
1.1 deraadt 162:
1.20 markus 163: void
1.11 markus 164: signal_handler(int sig)
1.1 deraadt 165: {
1.11 markus 166: if (in_raw_mode)
167: leave_raw_mode();
168: if (in_non_blocking_mode)
169: leave_non_blocking();
170: channel_stop_listening();
171: packet_close();
172: fatal("Killed by signal %d.", sig);
1.1 deraadt 173: }
174:
1.13 markus 175: /*
176: * Returns current time in seconds from Jan 1, 1970 with the maximum
177: * available resolution.
178: */
1.1 deraadt 179:
1.20 markus 180: double
1.11 markus 181: get_current_time()
1.1 deraadt 182: {
1.11 markus 183: struct timeval tv;
184: gettimeofday(&tv, NULL);
185: return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
1.1 deraadt 186: }
187:
1.13 markus 188: /*
189: * This is called when the interactive is entered. This checks if there is
190: * an EOF coming on stdin. We must check this explicitly, as select() does
191: * not appear to wake up when redirecting from /dev/null.
192: */
1.1 deraadt 193:
1.20 markus 194: void
1.11 markus 195: client_check_initial_eof_on_stdin()
1.1 deraadt 196: {
1.11 markus 197: int len;
198: char buf[1];
1.1 deraadt 199:
1.13 markus 200: /*
201: * If standard input is to be "redirected from /dev/null", we simply
202: * mark that we have seen an EOF and send an EOF message to the
203: * server. Otherwise, we try to read a single character; it appears
204: * that for some files, such /dev/null, select() never wakes up for
205: * read for this descriptor, which means that we never get EOF. This
206: * way we will get the EOF if stdin comes from /dev/null or similar.
207: */
1.11 markus 208: if (stdin_null_flag) {
209: /* Fake EOF on stdin. */
210: debug("Sending eof.");
211: stdin_eof = 1;
212: packet_start(SSH_CMSG_EOF);
213: packet_send();
214: } else {
215: enter_non_blocking();
216:
217: /* Check for immediate EOF on stdin. */
218: len = read(fileno(stdin), buf, 1);
219: if (len == 0) {
1.13 markus 220: /* EOF. Record that we have seen it and send EOF to server. */
1.11 markus 221: debug("Sending eof.");
222: stdin_eof = 1;
223: packet_start(SSH_CMSG_EOF);
224: packet_send();
225: } else if (len > 0) {
1.13 markus 226: /*
227: * Got data. We must store the data in the buffer,
228: * and also process it as an escape character if
229: * appropriate.
230: */
1.11 markus 231: if ((unsigned char) buf[0] == escape_char)
232: escape_pending = 1;
233: else {
234: buffer_append(&stdin_buffer, buf, 1);
235: stdin_bytes += 1;
236: }
237: }
238: leave_non_blocking();
239: }
1.1 deraadt 240: }
241:
242:
1.13 markus 243: /*
244: * Make packets from buffered stdin data, and buffer them for sending to the
245: * connection.
246: */
1.1 deraadt 247:
1.20 markus 248: void
1.11 markus 249: client_make_packets_from_stdin_data()
1.1 deraadt 250: {
1.11 markus 251: unsigned int len;
1.1 deraadt 252:
1.11 markus 253: /* Send buffered stdin data to the server. */
254: while (buffer_len(&stdin_buffer) > 0 &&
255: packet_not_very_much_data_to_write()) {
256: len = buffer_len(&stdin_buffer);
257: /* Keep the packets at reasonable size. */
258: if (len > packet_get_maxsize())
259: len = packet_get_maxsize();
260: packet_start(SSH_CMSG_STDIN_DATA);
261: packet_put_string(buffer_ptr(&stdin_buffer), len);
262: packet_send();
263: buffer_consume(&stdin_buffer, len);
264: /* If we have a pending EOF, send it now. */
265: if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
266: packet_start(SSH_CMSG_EOF);
267: packet_send();
268: }
1.1 deraadt 269: }
270: }
271:
1.13 markus 272: /*
273: * Checks if the client window has changed, and sends a packet about it to
274: * the server if so. The actual change is detected elsewhere (by a software
275: * interrupt on Unix); this just checks the flag and sends a message if
276: * appropriate.
277: */
1.1 deraadt 278:
1.20 markus 279: void
1.11 markus 280: client_check_window_change()
1.1 deraadt 281: {
1.16 markus 282: struct winsize ws;
283:
284: if (! received_window_change_signal)
285: return;
286: /** XXX race */
287: received_window_change_signal = 0;
288:
289: if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
290: return;
291:
292: debug("client_check_window_change: changed");
293:
294: if (compat20) {
295: channel_request_start(session_ident, "window-change", 0);
296: packet_put_int(ws.ws_col);
297: packet_put_int(ws.ws_row);
298: packet_put_int(ws.ws_xpixel);
299: packet_put_int(ws.ws_ypixel);
300: packet_send();
301: } else {
302: packet_start(SSH_CMSG_WINDOW_SIZE);
303: packet_put_int(ws.ws_row);
304: packet_put_int(ws.ws_col);
305: packet_put_int(ws.ws_xpixel);
306: packet_put_int(ws.ws_ypixel);
307: packet_send();
1.1 deraadt 308: }
309: }
310:
1.13 markus 311: /*
312: * Waits until the client can do something (some data becomes available on
313: * one of the file descriptors).
314: */
1.1 deraadt 315:
1.20 markus 316: void
1.11 markus 317: client_wait_until_can_do_something(fd_set * readset, fd_set * writeset)
318: {
1.16 markus 319: /*debug("client_wait_until_can_do_something"); */
320:
1.11 markus 321: /* Initialize select masks. */
322: FD_ZERO(readset);
1.17 markus 323: FD_ZERO(writeset);
1.11 markus 324:
1.16 markus 325: if (!compat20) {
1.17 markus 326: /* Read from the connection, unless our buffers are full. */
1.16 markus 327: if (buffer_len(&stdout_buffer) < buffer_high &&
328: buffer_len(&stderr_buffer) < buffer_high &&
329: channel_not_very_much_buffered_data())
330: FD_SET(connection_in, readset);
1.17 markus 331: /*
332: * Read from stdin, unless we have seen EOF or have very much
333: * buffered data to send to the server.
334: */
335: if (!stdin_eof && packet_not_very_much_data_to_write())
336: FD_SET(fileno(stdin), readset);
337:
338: /* Select stdout/stderr if have data in buffer. */
339: if (buffer_len(&stdout_buffer) > 0)
340: FD_SET(fileno(stdout), writeset);
341: if (buffer_len(&stderr_buffer) > 0)
342: FD_SET(fileno(stderr), writeset);
1.16 markus 343: } else {
1.11 markus 344: FD_SET(connection_in, readset);
1.16 markus 345: }
1.11 markus 346:
347: /* Add any selections by the channel mechanism. */
348: channel_prepare_select(readset, writeset);
349:
350: /* Select server connection if have data to write to the server. */
351: if (packet_have_data_to_write())
352: FD_SET(connection_out, writeset);
353:
1.16 markus 354: /* move UP XXX */
1.11 markus 355: /* Update maximum file descriptor number, if appropriate. */
356: if (channel_max_fd() > max_fd)
357: max_fd = channel_max_fd();
358:
1.13 markus 359: /*
360: * Wait for something to happen. This will suspend the process until
361: * some selected descriptor can be read, written, or has some other
362: * event pending. Note: if you want to implement SSH_MSG_IGNORE
363: * messages to fool traffic analysis, this might be the place to do
364: * it: just have a random timeout for the select, and send a random
365: * SSH_MSG_IGNORE packet when the timeout expires.
366: */
1.11 markus 367:
368: if (select(max_fd + 1, readset, writeset, NULL, NULL) < 0) {
369: char buf[100];
370: /* Some systems fail to clear these automatically. */
371: FD_ZERO(readset);
372: FD_ZERO(writeset);
373: if (errno == EINTR)
374: return;
375: /* Note: we might still have data in the buffers. */
376: snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
377: buffer_append(&stderr_buffer, buf, strlen(buf));
378: stderr_bytes += strlen(buf);
379: quit_pending = 1;
380: }
381: }
382:
1.20 markus 383: void
1.11 markus 384: client_suspend_self()
1.1 deraadt 385: {
1.11 markus 386: struct winsize oldws, newws;
387:
388: /* Flush stdout and stderr buffers. */
389: if (buffer_len(&stdout_buffer) > 0)
1.14 deraadt 390: atomicio(write, fileno(stdout), buffer_ptr(&stdout_buffer),
391: buffer_len(&stdout_buffer));
1.11 markus 392: if (buffer_len(&stderr_buffer) > 0)
1.14 deraadt 393: atomicio(write, fileno(stderr), buffer_ptr(&stderr_buffer),
394: buffer_len(&stderr_buffer));
1.11 markus 395:
396: leave_raw_mode();
397:
1.13 markus 398: /*
399: * Free (and clear) the buffer to reduce the amount of data that gets
400: * written to swap.
401: */
1.11 markus 402: buffer_free(&stdin_buffer);
403: buffer_free(&stdout_buffer);
404: buffer_free(&stderr_buffer);
405:
406: /* Save old window size. */
407: ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
408:
409: /* Send the suspend signal to the program itself. */
410: kill(getpid(), SIGTSTP);
411:
412: /* Check if the window size has changed. */
413: if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
414: (oldws.ws_row != newws.ws_row ||
415: oldws.ws_col != newws.ws_col ||
416: oldws.ws_xpixel != newws.ws_xpixel ||
417: oldws.ws_ypixel != newws.ws_ypixel))
418: received_window_change_signal = 1;
419:
420: /* OK, we have been continued by the user. Reinitialize buffers. */
421: buffer_init(&stdin_buffer);
422: buffer_init(&stdout_buffer);
423: buffer_init(&stderr_buffer);
424:
425: enter_raw_mode();
426: }
427:
1.20 markus 428: void
1.17 markus 429: client_process_net_input(fd_set * readset)
1.11 markus 430: {
1.17 markus 431: int len;
432: char buf[8192];
1.11 markus 433:
1.13 markus 434: /*
435: * Read input from the server, and add any such data to the buffer of
436: * the packet subsystem.
437: */
1.11 markus 438: if (FD_ISSET(connection_in, readset)) {
439: /* Read as much as possible. */
440: len = read(connection_in, buf, sizeof(buf));
1.16 markus 441: /*debug("read connection_in len %d", len); XXX */
1.11 markus 442: if (len == 0) {
443: /* Received EOF. The remote host has closed the connection. */
444: snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
445: host);
1.1 deraadt 446: buffer_append(&stderr_buffer, buf, strlen(buf));
447: stderr_bytes += strlen(buf);
448: quit_pending = 1;
449: return;
1.11 markus 450: }
1.13 markus 451: /*
452: * There is a kernel bug on Solaris that causes select to
453: * sometimes wake up even though there is no data available.
454: */
1.11 markus 455: if (len < 0 && errno == EAGAIN)
456: len = 0;
457:
458: if (len < 0) {
459: /* An error has encountered. Perhaps there is a network problem. */
460: snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
461: host, strerror(errno));
462: buffer_append(&stderr_buffer, buf, strlen(buf));
463: stderr_bytes += strlen(buf);
464: quit_pending = 1;
465: return;
466: }
467: packet_process_incoming(buf, len);
468: }
1.17 markus 469: }
1.16 markus 470:
1.20 markus 471: void
1.17 markus 472: client_process_input(fd_set * readset)
473: {
1.21 deraadt 474: int len;
475: pid_t pid;
1.17 markus 476: char buf[8192], *s;
1.16 markus 477:
1.11 markus 478: /* Read input from stdin. */
479: if (FD_ISSET(fileno(stdin), readset)) {
480: /* Read as much as possible. */
481: len = read(fileno(stdin), buf, sizeof(buf));
482: if (len <= 0) {
1.13 markus 483: /*
484: * Received EOF or error. They are treated
485: * similarly, except that an error message is printed
486: * if it was an error condition.
487: */
1.11 markus 488: if (len < 0) {
489: snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
490: buffer_append(&stderr_buffer, buf, strlen(buf));
491: stderr_bytes += strlen(buf);
492: }
493: /* Mark that we have seen EOF. */
494: stdin_eof = 1;
1.13 markus 495: /*
496: * Send an EOF message to the server unless there is
497: * data in the buffer. If there is data in the
498: * buffer, no message will be sent now. Code
499: * elsewhere will send the EOF when the buffer
500: * becomes empty if stdin_eof is set.
501: */
1.11 markus 502: if (buffer_len(&stdin_buffer) == 0) {
1.1 deraadt 503: packet_start(SSH_CMSG_EOF);
504: packet_send();
1.11 markus 505: }
506: } else if (escape_char == -1) {
1.13 markus 507: /*
508: * Normal successful read, and no escape character.
509: * Just append the data to buffer.
510: */
1.11 markus 511: buffer_append(&stdin_buffer, buf, len);
512: stdin_bytes += len;
513: } else {
1.13 markus 514: /*
515: * Normal, successful read. But we have an escape character
516: * and have to process the characters one by one.
517: */
1.11 markus 518: unsigned int i;
519: for (i = 0; i < len; i++) {
520: unsigned char ch;
521: /* Get one character at a time. */
522: ch = buf[i];
523:
524: if (escape_pending) {
525: /* We have previously seen an escape character. */
526: /* Clear the flag now. */
527: escape_pending = 0;
528: /* Process the escaped character. */
529: switch (ch) {
530: case '.':
531: /* Terminate the connection. */
532: snprintf(buf, sizeof buf, "%c.\r\n", escape_char);
533: buffer_append(&stderr_buffer, buf, strlen(buf));
534: stderr_bytes += strlen(buf);
535: quit_pending = 1;
536: return;
537:
538: case 'Z' - 64:
539: /* Suspend the program. */
540: /* Print a message to that effect to the user. */
541: snprintf(buf, sizeof buf, "%c^Z\r\n", escape_char);
542: buffer_append(&stderr_buffer, buf, strlen(buf));
543: stderr_bytes += strlen(buf);
544:
545: /* Restore terminal modes and suspend. */
546: client_suspend_self();
547:
548: /* We have been continued. */
549: continue;
550:
551: case '&':
1.13 markus 552: /*
553: * Detach the program (continue to serve connections,
554: * but put in background and no more new connections).
555: */
1.11 markus 556: if (!stdin_eof) {
1.13 markus 557: /*
558: * Sending SSH_CMSG_EOF alone does not always appear
559: * to be enough. So we try to send an EOF character
560: * first.
561: */
1.11 markus 562: packet_start(SSH_CMSG_STDIN_DATA);
563: packet_put_string("\004", 1);
564: packet_send();
565: /* Close stdin. */
566: stdin_eof = 1;
567: if (buffer_len(&stdin_buffer) == 0) {
568: packet_start(SSH_CMSG_EOF);
569: packet_send();
570: }
571: }
572: /* Restore tty modes. */
573: leave_raw_mode();
574:
575: /* Stop listening for new connections. */
576: channel_stop_listening();
577:
578: printf("%c& [backgrounded]\n", escape_char);
579:
580: /* Fork into background. */
581: pid = fork();
582: if (pid < 0) {
583: error("fork: %.100s", strerror(errno));
584: continue;
585: }
586: if (pid != 0) { /* This is the parent. */
587: /* The parent just exits. */
588: exit(0);
589: }
590: /* The child continues serving connections. */
591: continue;
592:
593: case '?':
594: snprintf(buf, sizeof buf,
595: "%c?\r\n\
1.1 deraadt 596: Supported escape sequences:\r\n\
597: ~. - terminate connection\r\n\
598: ~^Z - suspend ssh\r\n\
599: ~# - list forwarded connections\r\n\
600: ~& - background ssh (when waiting for connections to terminate)\r\n\
601: ~? - this message\r\n\
602: ~~ - send the escape character by typing it twice\r\n\
603: (Note that escapes are only recognized immediately after newline.)\r\n",
1.11 markus 604: escape_char);
605: buffer_append(&stderr_buffer, buf, strlen(buf));
606: continue;
607:
608: case '#':
609: snprintf(buf, sizeof buf, "%c#\r\n", escape_char);
610: buffer_append(&stderr_buffer, buf, strlen(buf));
611: s = channel_open_message();
612: buffer_append(&stderr_buffer, s, strlen(s));
613: xfree(s);
614: continue;
615:
616: default:
617: if (ch != escape_char) {
1.13 markus 618: /*
619: * Escape character followed by non-special character.
620: * Append both to the input buffer.
621: */
1.11 markus 622: buf[0] = escape_char;
623: buf[1] = ch;
624: buffer_append(&stdin_buffer, buf, 2);
625: stdin_bytes += 2;
626: continue;
627: }
1.13 markus 628: /*
629: * Note that escape character typed twice
630: * falls through here; the latter gets processed
631: * as a normal character below.
632: */
1.11 markus 633: break;
634: }
635: } else {
1.13 markus 636: /*
637: * The previous character was not an escape char. Check if this
638: * is an escape.
639: */
1.11 markus 640: if (last_was_cr && ch == escape_char) {
641: /* It is. Set the flag and continue to next character. */
642: escape_pending = 1;
643: continue;
644: }
645: }
646:
1.13 markus 647: /*
648: * Normal character. Record whether it was a newline,
649: * and append it to the buffer.
650: */
1.11 markus 651: last_was_cr = (ch == '\r' || ch == '\n');
652: buf[0] = ch;
653: buffer_append(&stdin_buffer, buf, 1);
654: stdin_bytes += 1;
655: continue;
656: }
657: }
658: }
659: }
660:
1.20 markus 661: void
1.11 markus 662: client_process_output(fd_set * writeset)
663: {
664: int len;
665: char buf[100];
1.1 deraadt 666:
1.11 markus 667: /* Write buffered output to stdout. */
668: if (FD_ISSET(fileno(stdout), writeset)) {
669: /* Write as much data as possible. */
670: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 671: buffer_len(&stdout_buffer));
1.11 markus 672: if (len <= 0) {
673: if (errno == EAGAIN)
674: len = 0;
675: else {
1.13 markus 676: /*
677: * An error or EOF was encountered. Put an
678: * error message to stderr buffer.
679: */
1.11 markus 680: snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
681: buffer_append(&stderr_buffer, buf, strlen(buf));
682: stderr_bytes += strlen(buf);
683: quit_pending = 1;
684: return;
685: }
686: }
687: /* Consume printed data from the buffer. */
688: buffer_consume(&stdout_buffer, len);
689: }
690: /* Write buffered output to stderr. */
691: if (FD_ISSET(fileno(stderr), writeset)) {
692: /* Write as much data as possible. */
693: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 694: buffer_len(&stderr_buffer));
1.11 markus 695: if (len <= 0) {
696: if (errno == EAGAIN)
697: len = 0;
698: else {
1.13 markus 699: /* EOF or error, but can't even print error message. */
1.11 markus 700: quit_pending = 1;
701: return;
702: }
703: }
704: /* Consume printed characters from the buffer. */
705: buffer_consume(&stderr_buffer, len);
706: }
1.1 deraadt 707: }
708:
1.13 markus 709: /*
1.15 markus 710: * Get packets from the connection input buffer, and process them as long as
711: * there are packets available.
712: *
713: * Any unknown packets received during the actual
714: * session cause the session to terminate. This is
715: * intended to make debugging easier since no
716: * confirmations are sent. Any compatible protocol
717: * extensions must be negotiated during the
718: * preparatory phase.
719: */
720:
1.20 markus 721: void
1.15 markus 722: client_process_buffered_input_packets()
723: {
724: dispatch_run(DISPATCH_NONBLOCK, &quit_pending);
725: }
726:
727: /*
1.13 markus 728: * Implements the interactive session with the server. This is called after
729: * the user has been authenticated, and a command has been started on the
730: * remote host. If escape_char != -1, it is the character used as an escape
731: * character for terminating or suspending the session.
732: */
1.1 deraadt 733:
1.20 markus 734: int
1.11 markus 735: client_loop(int have_pty, int escape_char_arg)
1.1 deraadt 736: {
1.11 markus 737: extern Options options;
738: double start_time, total_time;
739: int len;
740: char buf[100];
741:
742: debug("Entering interactive session.");
743:
744: start_time = get_current_time();
745:
746: /* Initialize variables. */
747: escape_pending = 0;
748: last_was_cr = 1;
749: exit_status = -1;
750: stdin_eof = 0;
751: buffer_high = 64 * 1024;
752: connection_in = packet_get_connection_in();
753: connection_out = packet_get_connection_out();
754: max_fd = connection_in;
755: if (connection_out > max_fd)
756: max_fd = connection_out;
757: stdin_bytes = 0;
758: stdout_bytes = 0;
759: stderr_bytes = 0;
760: quit_pending = 0;
761: escape_char = escape_char_arg;
762:
763: /* Initialize buffers. */
764: buffer_init(&stdin_buffer);
765: buffer_init(&stdout_buffer);
766: buffer_init(&stderr_buffer);
767:
1.15 markus 768: client_init_dispatch();
769:
1.11 markus 770: /* Set signal handlers to restore non-blocking mode. */
771: signal(SIGINT, signal_handler);
772: signal(SIGQUIT, signal_handler);
773: signal(SIGTERM, signal_handler);
774: signal(SIGPIPE, SIG_IGN);
775: if (have_pty)
776: signal(SIGWINCH, window_change_handler);
777:
778: if (have_pty)
779: enter_raw_mode();
780:
781: /* Check if we should immediately send of on stdin. */
1.17 markus 782: if (!compat20)
1.16 markus 783: client_check_initial_eof_on_stdin();
1.11 markus 784:
785: /* Main loop of the client for the interactive session mode. */
786: while (!quit_pending) {
787: fd_set readset, writeset;
788:
1.13 markus 789: /* Process buffered packets sent by the server. */
1.11 markus 790: client_process_buffered_input_packets();
791:
1.16 markus 792: if (compat20 && !channel_still_open()) {
793: debug("!channel_still_open.");
794: break;
795: }
796:
1.13 markus 797: /*
798: * Make packets of buffered stdin data, and buffer them for
799: * sending to the server.
800: */
1.17 markus 801: if (!compat20)
1.16 markus 802: client_make_packets_from_stdin_data();
1.11 markus 803:
1.13 markus 804: /*
805: * Make packets from buffered channel data, and buffer them
806: * for sending to the server.
807: */
1.11 markus 808: if (packet_not_very_much_data_to_write())
809: channel_output_poll();
810:
1.13 markus 811: /*
812: * Check if the window size has changed, and buffer a message
813: * about it to the server if so.
814: */
1.11 markus 815: client_check_window_change();
816:
817: if (quit_pending)
818: break;
819:
1.13 markus 820: /*
821: * Wait until we have something to do (something becomes
822: * available on one of the descriptors).
823: */
1.11 markus 824: client_wait_until_can_do_something(&readset, &writeset);
825:
826: if (quit_pending)
827: break;
828:
829: /* Do channel operations. */
830: channel_after_select(&readset, &writeset);
831:
1.17 markus 832: /* Buffer input from the connection. */
833: client_process_net_input(&readset);
834:
835: if (quit_pending)
836: break;
1.11 markus 837:
1.17 markus 838: if (!compat20) {
839: /* Buffer data from stdin */
840: client_process_input(&readset);
841: /*
842: * Process output to stdout and stderr. Output to
843: * the connection is processed elsewhere (above).
844: */
1.16 markus 845: client_process_output(&writeset);
1.17 markus 846: }
1.11 markus 847:
1.13 markus 848: /* Send as much buffered packet data as possible to the sender. */
1.11 markus 849: if (FD_ISSET(connection_out, &writeset))
850: packet_write_poll();
851: }
852:
853: /* Terminate the session. */
854:
855: /* Stop watching for window change. */
856: if (have_pty)
857: signal(SIGWINCH, SIG_DFL);
858:
859: /* Stop listening for connections. */
860: channel_stop_listening();
861:
1.13 markus 862: /*
863: * In interactive mode (with pseudo tty) display a message indicating
864: * that the connection has been closed.
865: */
1.11 markus 866: if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
867: snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
868: buffer_append(&stderr_buffer, buf, strlen(buf));
869: stderr_bytes += strlen(buf);
870: }
871: /* Output any buffered data for stdout. */
872: while (buffer_len(&stdout_buffer) > 0) {
873: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 874: buffer_len(&stdout_buffer));
1.11 markus 875: if (len <= 0) {
876: error("Write failed flushing stdout buffer.");
877: break;
878: }
879: buffer_consume(&stdout_buffer, len);
880: }
881:
882: /* Output any buffered data for stderr. */
883: while (buffer_len(&stderr_buffer) > 0) {
884: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 885: buffer_len(&stderr_buffer));
1.11 markus 886: if (len <= 0) {
887: error("Write failed flushing stderr buffer.");
888: break;
889: }
890: buffer_consume(&stderr_buffer, len);
891: }
892:
893: if (have_pty)
894: leave_raw_mode();
895:
896: /* Clear and free any buffers. */
897: memset(buf, 0, sizeof(buf));
898: buffer_free(&stdin_buffer);
899: buffer_free(&stdout_buffer);
900: buffer_free(&stderr_buffer);
901:
902: /* Report bytes transferred, and transfer rates. */
903: total_time = get_current_time() - start_time;
904: debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
905: stdin_bytes, stdout_bytes, stderr_bytes, total_time);
906: if (total_time > 0)
907: debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
908: stdin_bytes / total_time, stdout_bytes / total_time,
909: stderr_bytes / total_time);
910:
911: /* Return the exit status of the program. */
912: debug("Exit status %d", exit_status);
913: return exit_status;
1.15 markus 914: }
915:
916: /*********/
917:
918: void
919: client_input_stdout_data(int type, int plen)
920: {
921: unsigned int data_len;
922: char *data = packet_get_string(&data_len);
923: packet_integrity_check(plen, 4 + data_len, type);
924: buffer_append(&stdout_buffer, data, data_len);
925: stdout_bytes += data_len;
926: memset(data, 0, data_len);
927: xfree(data);
928: }
929: void
930: client_input_stderr_data(int type, int plen)
931: {
932: unsigned int data_len;
933: char *data = packet_get_string(&data_len);
934: packet_integrity_check(plen, 4 + data_len, type);
935: buffer_append(&stderr_buffer, data, data_len);
936: stdout_bytes += data_len;
937: memset(data, 0, data_len);
938: xfree(data);
939: }
940: void
941: client_input_exit_status(int type, int plen)
942: {
943: packet_integrity_check(plen, 4, type);
944: exit_status = packet_get_int();
945: /* Acknowledge the exit. */
946: packet_start(SSH_CMSG_EXIT_CONFIRMATION);
947: packet_send();
948: /*
949: * Must wait for packet to be sent since we are
950: * exiting the loop.
951: */
952: packet_write_wait();
953: /* Flag that we want to exit. */
954: quit_pending = 1;
955: }
956:
1.22 markus 957: /* XXXX move to generic input handler */
958: void
959: client_input_channel_open(int type, int plen)
960: {
961: Channel *c = NULL;
962: char *ctype;
963: int id;
964: unsigned int len;
965: int rchan;
966: int rmaxpack;
967: int rwindow;
968:
969: ctype = packet_get_string(&len);
970: rchan = packet_get_int();
971: rwindow = packet_get_int();
972: rmaxpack = packet_get_int();
973:
974: log("server_input_open: ctype %s rchan %d win %d max %d",
975: ctype, rchan, rwindow, rmaxpack);
976:
977: if (strcmp(ctype, "x11") == 0) {
978: int sock;
979: char *originator;
980: int originator_port;
981: originator = packet_get_string(NULL);
982: originator_port = packet_get_int();
983: packet_done();
984: /* XXX check permission */
985: xfree(originator);
986: /* XXX move to channels.c */
987: sock = x11_connect_display();
988: if (sock >= 0) {
989: id = channel_new("x11", SSH_CHANNEL_X11_OPEN,
990: sock, sock, -1, 4*1024, 32*1024, 0,
991: xstrdup("x11"));
992: c = channel_lookup(id);
993: }
994: }
995: /* XXX duplicate : */
996: if (c != NULL) {
997: debug("confirm %s", ctype);
998: c->remote_id = rchan;
999: c->remote_window = rwindow;
1000: c->remote_maxpacket = rmaxpack;
1001:
1002: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1003: packet_put_int(c->remote_id);
1004: packet_put_int(c->self);
1005: packet_put_int(c->local_window);
1006: packet_put_int(c->local_maxpacket);
1007: packet_send();
1008: } else {
1009: debug("failure %s", ctype);
1010: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1011: packet_put_int(rchan);
1012: packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1013: packet_put_cstring("bla bla");
1014: packet_put_cstring("");
1015: packet_send();
1016: }
1017: xfree(ctype);
1018: }
1019:
1.20 markus 1020: void
1.16 markus 1021: client_init_dispatch_20()
1022: {
1023: dispatch_init(&dispatch_protocol_error);
1024: dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1025: dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1026: dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1027: dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1.22 markus 1028: dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1.16 markus 1029: dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1030: dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1031: dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
1032: dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1033: }
1.20 markus 1034: void
1.15 markus 1035: client_init_dispatch_13()
1036: {
1037: dispatch_init(NULL);
1038: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1039: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1040: dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1041: dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1042: dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1043: dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1044: dispatch_set(SSH_SMSG_AGENT_OPEN, &auth_input_open_request);
1045: dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1046: dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1047: dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1048: dispatch_set(SSH_SMSG_X11_OPEN, &x11_input_open);
1049: }
1.20 markus 1050: void
1.15 markus 1051: client_init_dispatch_15()
1052: {
1053: client_init_dispatch_13();
1054: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1055: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1056: }
1.20 markus 1057: void
1.15 markus 1058: client_init_dispatch()
1059: {
1.16 markus 1060: if (compat20)
1061: client_init_dispatch_20();
1062: else if (compat13)
1.15 markus 1063: client_init_dispatch_13();
1064: else
1065: client_init_dispatch_15();
1.16 markus 1066: }
1067:
1068: void
1069: client_input_channel_req(int id, void *arg)
1070: {
1071: Channel *c = NULL;
1072: unsigned int len;
1073: int success = 0;
1074: int reply;
1075: char *rtype;
1076:
1077: rtype = packet_get_string(&len);
1078: reply = packet_get_char();
1079:
1.23 ! markus 1080: debug("client_input_channel_req: rtype %s reply %d", rtype, reply);
1.16 markus 1081:
1082: c = channel_lookup(id);
1083: if (c == NULL)
1084: fatal("session_input_channel_req: channel %d: bad channel", id);
1085:
1086: if (session_ident == -1) {
1087: error("client_input_channel_req: no channel %d", id);
1088: } else if (id != session_ident) {
1089: error("client_input_channel_req: bad channel %d != %d",
1090: id, session_ident);
1091: } else if (strcmp(rtype, "exit-status") == 0) {
1092: success = 1;
1093: exit_status = packet_get_int();
1.19 markus 1094: packet_done();
1.16 markus 1095: }
1096: if (reply) {
1097: packet_start(success ?
1098: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1099: packet_put_int(c->remote_id);
1100: packet_send();
1101: }
1102: xfree(rtype);
1103: }
1104:
1105: void
1106: client_set_session_ident(int id)
1107: {
1108: debug("client_set_session_ident: id %d", id);
1109: session_ident = id;
1110: channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
1111: client_input_channel_req, (void *)0);
1.1 deraadt 1112: }
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