Annotation of src/usr.bin/ssh/clientloop.c, Revision 1.16
1.1 deraadt 1: /*
1.12 deraadt 2: *
3: * clientloop.c
4: *
5: * Author: Tatu Ylonen <ylo@cs.hut.fi>
6: *
7: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8: * All rights reserved
9: *
10: *
11: * Created: Sat Sep 23 12:23:57 1995 ylo
12: *
13: * The main loop for the interactive session (client side).
14: *
1.16 ! markus 15: * SSH2 support added by Markus Friedl.
1.12 deraadt 16: */
1.1 deraadt 17:
18: #include "includes.h"
1.16 ! markus 19: RCSID("$Id: clientloop.c,v 1.12 2000/03/31 09:40:42 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:
1.11 markus 86: void
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:
1.11 markus 100: void
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:
1.11 markus 126: void
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:
138: void
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:
1.11 markus 151: void
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:
1.11 markus 163: void
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:
1.11 markus 180: double
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:
1.11 markus 194: void
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:
1.11 markus 248: void
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:
1.11 markus 279: void
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:
1.11 markus 316: void
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);
323:
324: /* Read from the connection, unless our buffers are full. */
1.16 ! markus 325: if (!compat20) {
! 326: if (buffer_len(&stdout_buffer) < buffer_high &&
! 327: buffer_len(&stderr_buffer) < buffer_high &&
! 328: channel_not_very_much_buffered_data())
! 329: FD_SET(connection_in, readset);
! 330: } else {
1.11 markus 331: FD_SET(connection_in, readset);
1.16 ! markus 332: }
1.11 markus 333:
1.13 markus 334: /*
335: * Read from stdin, unless we have seen EOF or have very much
336: * buffered data to send to the server.
337: */
1.16 ! markus 338: if (!compat20)
! 339: if (!stdin_eof && packet_not_very_much_data_to_write())
! 340: FD_SET(fileno(stdin), readset);
1.11 markus 341:
342: FD_ZERO(writeset);
343:
344: /* Add any selections by the channel mechanism. */
345: channel_prepare_select(readset, writeset);
346:
347: /* Select server connection if have data to write to the server. */
348: if (packet_have_data_to_write())
349: FD_SET(connection_out, writeset);
350:
1.16 ! markus 351: if (!compat20) {
! 352: /* Select stdout if have data in buffer. */
! 353: if (buffer_len(&stdout_buffer) > 0)
! 354: FD_SET(fileno(stdout), writeset);
! 355:
! 356: /* Select stderr if have data in buffer. */
! 357: if (buffer_len(&stderr_buffer) > 0)
! 358: FD_SET(fileno(stderr), writeset);
! 359: }
1.11 markus 360:
1.16 ! markus 361: /* move UP XXX */
1.11 markus 362: /* Update maximum file descriptor number, if appropriate. */
363: if (channel_max_fd() > max_fd)
364: max_fd = channel_max_fd();
365:
1.13 markus 366: /*
367: * Wait for something to happen. This will suspend the process until
368: * some selected descriptor can be read, written, or has some other
369: * event pending. Note: if you want to implement SSH_MSG_IGNORE
370: * messages to fool traffic analysis, this might be the place to do
371: * it: just have a random timeout for the select, and send a random
372: * SSH_MSG_IGNORE packet when the timeout expires.
373: */
1.11 markus 374:
375: if (select(max_fd + 1, readset, writeset, NULL, NULL) < 0) {
376: char buf[100];
377: /* Some systems fail to clear these automatically. */
378: FD_ZERO(readset);
379: FD_ZERO(writeset);
380: if (errno == EINTR)
381: return;
382: /* Note: we might still have data in the buffers. */
383: snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
384: buffer_append(&stderr_buffer, buf, strlen(buf));
385: stderr_bytes += strlen(buf);
386: quit_pending = 1;
387: }
388: }
389:
390: void
391: client_suspend_self()
1.1 deraadt 392: {
1.11 markus 393: struct winsize oldws, newws;
394:
395: /* Flush stdout and stderr buffers. */
396: if (buffer_len(&stdout_buffer) > 0)
1.14 deraadt 397: atomicio(write, fileno(stdout), buffer_ptr(&stdout_buffer),
398: buffer_len(&stdout_buffer));
1.11 markus 399: if (buffer_len(&stderr_buffer) > 0)
1.14 deraadt 400: atomicio(write, fileno(stderr), buffer_ptr(&stderr_buffer),
401: buffer_len(&stderr_buffer));
1.11 markus 402:
403: leave_raw_mode();
404:
1.13 markus 405: /*
406: * Free (and clear) the buffer to reduce the amount of data that gets
407: * written to swap.
408: */
1.11 markus 409: buffer_free(&stdin_buffer);
410: buffer_free(&stdout_buffer);
411: buffer_free(&stderr_buffer);
412:
413: /* Save old window size. */
414: ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
415:
416: /* Send the suspend signal to the program itself. */
417: kill(getpid(), SIGTSTP);
418:
419: /* Check if the window size has changed. */
420: if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
421: (oldws.ws_row != newws.ws_row ||
422: oldws.ws_col != newws.ws_col ||
423: oldws.ws_xpixel != newws.ws_xpixel ||
424: oldws.ws_ypixel != newws.ws_ypixel))
425: received_window_change_signal = 1;
426:
427: /* OK, we have been continued by the user. Reinitialize buffers. */
428: buffer_init(&stdin_buffer);
429: buffer_init(&stdout_buffer);
430: buffer_init(&stderr_buffer);
431:
432: enter_raw_mode();
433: }
434:
435: void
436: client_process_input(fd_set * readset)
437: {
438: int len, pid;
439: char buf[8192], *s;
440:
1.13 markus 441: /*
442: * Read input from the server, and add any such data to the buffer of
443: * the packet subsystem.
444: */
1.11 markus 445: if (FD_ISSET(connection_in, readset)) {
446: /* Read as much as possible. */
447: len = read(connection_in, buf, sizeof(buf));
1.16 ! markus 448: /*debug("read connection_in len %d", len); XXX */
1.11 markus 449: if (len == 0) {
450: /* Received EOF. The remote host has closed the connection. */
451: snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
452: host);
1.1 deraadt 453: buffer_append(&stderr_buffer, buf, strlen(buf));
454: stderr_bytes += strlen(buf);
455: quit_pending = 1;
456: return;
1.11 markus 457: }
1.13 markus 458: /*
459: * There is a kernel bug on Solaris that causes select to
460: * sometimes wake up even though there is no data available.
461: */
1.11 markus 462: if (len < 0 && errno == EAGAIN)
463: len = 0;
464:
465: if (len < 0) {
466: /* An error has encountered. Perhaps there is a network problem. */
467: snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
468: host, strerror(errno));
469: buffer_append(&stderr_buffer, buf, strlen(buf));
470: stderr_bytes += strlen(buf);
471: quit_pending = 1;
472: return;
473: }
474: packet_process_incoming(buf, len);
475: }
1.16 ! markus 476:
! 477: if (compat20)
! 478: return;
! 479:
1.11 markus 480: /* Read input from stdin. */
481: if (FD_ISSET(fileno(stdin), readset)) {
482: /* Read as much as possible. */
483: len = read(fileno(stdin), buf, sizeof(buf));
484: if (len <= 0) {
1.13 markus 485: /*
486: * Received EOF or error. They are treated
487: * similarly, except that an error message is printed
488: * if it was an error condition.
489: */
1.11 markus 490: if (len < 0) {
491: snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
492: buffer_append(&stderr_buffer, buf, strlen(buf));
493: stderr_bytes += strlen(buf);
494: }
495: /* Mark that we have seen EOF. */
496: stdin_eof = 1;
1.13 markus 497: /*
498: * Send an EOF message to the server unless there is
499: * data in the buffer. If there is data in the
500: * buffer, no message will be sent now. Code
501: * elsewhere will send the EOF when the buffer
502: * becomes empty if stdin_eof is set.
503: */
1.11 markus 504: if (buffer_len(&stdin_buffer) == 0) {
1.1 deraadt 505: packet_start(SSH_CMSG_EOF);
506: packet_send();
1.11 markus 507: }
508: } else if (escape_char == -1) {
1.13 markus 509: /*
510: * Normal successful read, and no escape character.
511: * Just append the data to buffer.
512: */
1.11 markus 513: buffer_append(&stdin_buffer, buf, len);
514: stdin_bytes += len;
515: } else {
1.13 markus 516: /*
517: * Normal, successful read. But we have an escape character
518: * and have to process the characters one by one.
519: */
1.11 markus 520: unsigned int i;
521: for (i = 0; i < len; i++) {
522: unsigned char ch;
523: /* Get one character at a time. */
524: ch = buf[i];
525:
526: if (escape_pending) {
527: /* We have previously seen an escape character. */
528: /* Clear the flag now. */
529: escape_pending = 0;
530: /* Process the escaped character. */
531: switch (ch) {
532: case '.':
533: /* Terminate the connection. */
534: snprintf(buf, sizeof buf, "%c.\r\n", escape_char);
535: buffer_append(&stderr_buffer, buf, strlen(buf));
536: stderr_bytes += strlen(buf);
537: quit_pending = 1;
538: return;
539:
540: case 'Z' - 64:
541: /* Suspend the program. */
542: /* Print a message to that effect to the user. */
543: snprintf(buf, sizeof buf, "%c^Z\r\n", escape_char);
544: buffer_append(&stderr_buffer, buf, strlen(buf));
545: stderr_bytes += strlen(buf);
546:
547: /* Restore terminal modes and suspend. */
548: client_suspend_self();
549:
550: /* We have been continued. */
551: continue;
552:
553: case '&':
1.13 markus 554: /*
555: * Detach the program (continue to serve connections,
556: * but put in background and no more new connections).
557: */
1.11 markus 558: if (!stdin_eof) {
1.13 markus 559: /*
560: * Sending SSH_CMSG_EOF alone does not always appear
561: * to be enough. So we try to send an EOF character
562: * first.
563: */
1.11 markus 564: packet_start(SSH_CMSG_STDIN_DATA);
565: packet_put_string("\004", 1);
566: packet_send();
567: /* Close stdin. */
568: stdin_eof = 1;
569: if (buffer_len(&stdin_buffer) == 0) {
570: packet_start(SSH_CMSG_EOF);
571: packet_send();
572: }
573: }
574: /* Restore tty modes. */
575: leave_raw_mode();
576:
577: /* Stop listening for new connections. */
578: channel_stop_listening();
579:
580: printf("%c& [backgrounded]\n", escape_char);
581:
582: /* Fork into background. */
583: pid = fork();
584: if (pid < 0) {
585: error("fork: %.100s", strerror(errno));
586: continue;
587: }
588: if (pid != 0) { /* This is the parent. */
589: /* The parent just exits. */
590: exit(0);
591: }
592: /* The child continues serving connections. */
593: continue;
594:
595: case '?':
596: snprintf(buf, sizeof buf,
597: "%c?\r\n\
1.1 deraadt 598: Supported escape sequences:\r\n\
599: ~. - terminate connection\r\n\
600: ~^Z - suspend ssh\r\n\
601: ~# - list forwarded connections\r\n\
602: ~& - background ssh (when waiting for connections to terminate)\r\n\
603: ~? - this message\r\n\
604: ~~ - send the escape character by typing it twice\r\n\
605: (Note that escapes are only recognized immediately after newline.)\r\n",
1.11 markus 606: escape_char);
607: buffer_append(&stderr_buffer, buf, strlen(buf));
608: continue;
609:
610: case '#':
611: snprintf(buf, sizeof buf, "%c#\r\n", escape_char);
612: buffer_append(&stderr_buffer, buf, strlen(buf));
613: s = channel_open_message();
614: buffer_append(&stderr_buffer, s, strlen(s));
615: xfree(s);
616: continue;
617:
618: default:
619: if (ch != escape_char) {
1.13 markus 620: /*
621: * Escape character followed by non-special character.
622: * Append both to the input buffer.
623: */
1.11 markus 624: buf[0] = escape_char;
625: buf[1] = ch;
626: buffer_append(&stdin_buffer, buf, 2);
627: stdin_bytes += 2;
628: continue;
629: }
1.13 markus 630: /*
631: * Note that escape character typed twice
632: * falls through here; the latter gets processed
633: * as a normal character below.
634: */
1.11 markus 635: break;
636: }
637: } else {
1.13 markus 638: /*
639: * The previous character was not an escape char. Check if this
640: * is an escape.
641: */
1.11 markus 642: if (last_was_cr && ch == escape_char) {
643: /* It is. Set the flag and continue to next character. */
644: escape_pending = 1;
645: continue;
646: }
647: }
648:
1.13 markus 649: /*
650: * Normal character. Record whether it was a newline,
651: * and append it to the buffer.
652: */
1.11 markus 653: last_was_cr = (ch == '\r' || ch == '\n');
654: buf[0] = ch;
655: buffer_append(&stdin_buffer, buf, 1);
656: stdin_bytes += 1;
657: continue;
658: }
659: }
660: }
661: }
662:
663: void
664: client_process_output(fd_set * writeset)
665: {
666: int len;
667: char buf[100];
1.1 deraadt 668:
1.11 markus 669: /* Write buffered output to stdout. */
670: if (FD_ISSET(fileno(stdout), writeset)) {
671: /* Write as much data as possible. */
672: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 673: buffer_len(&stdout_buffer));
1.11 markus 674: if (len <= 0) {
675: if (errno == EAGAIN)
676: len = 0;
677: else {
1.13 markus 678: /*
679: * An error or EOF was encountered. Put an
680: * error message to stderr buffer.
681: */
1.11 markus 682: snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
683: buffer_append(&stderr_buffer, buf, strlen(buf));
684: stderr_bytes += strlen(buf);
685: quit_pending = 1;
686: return;
687: }
688: }
689: /* Consume printed data from the buffer. */
690: buffer_consume(&stdout_buffer, len);
691: }
692: /* Write buffered output to stderr. */
693: if (FD_ISSET(fileno(stderr), writeset)) {
694: /* Write as much data as possible. */
695: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 696: buffer_len(&stderr_buffer));
1.11 markus 697: if (len <= 0) {
698: if (errno == EAGAIN)
699: len = 0;
700: else {
1.13 markus 701: /* EOF or error, but can't even print error message. */
1.11 markus 702: quit_pending = 1;
703: return;
704: }
705: }
706: /* Consume printed characters from the buffer. */
707: buffer_consume(&stderr_buffer, len);
708: }
1.1 deraadt 709: }
710:
1.13 markus 711: /*
1.15 markus 712: * Get packets from the connection input buffer, and process them as long as
713: * there are packets available.
714: *
715: * Any unknown packets received during the actual
716: * session cause the session to terminate. This is
717: * intended to make debugging easier since no
718: * confirmations are sent. Any compatible protocol
719: * extensions must be negotiated during the
720: * preparatory phase.
721: */
722:
723: void
724: client_process_buffered_input_packets()
725: {
726: dispatch_run(DISPATCH_NONBLOCK, &quit_pending);
727: }
728:
729: /*
1.13 markus 730: * Implements the interactive session with the server. This is called after
731: * the user has been authenticated, and a command has been started on the
732: * remote host. If escape_char != -1, it is the character used as an escape
733: * character for terminating or suspending the session.
734: */
1.1 deraadt 735:
1.11 markus 736: int
737: client_loop(int have_pty, int escape_char_arg)
1.1 deraadt 738: {
1.11 markus 739: extern Options options;
740: double start_time, total_time;
741: int len;
742: char buf[100];
743:
744: debug("Entering interactive session.");
745:
746: start_time = get_current_time();
747:
748: /* Initialize variables. */
749: escape_pending = 0;
750: last_was_cr = 1;
751: exit_status = -1;
752: stdin_eof = 0;
753: buffer_high = 64 * 1024;
754: connection_in = packet_get_connection_in();
755: connection_out = packet_get_connection_out();
756: max_fd = connection_in;
757: if (connection_out > max_fd)
758: max_fd = connection_out;
759: stdin_bytes = 0;
760: stdout_bytes = 0;
761: stderr_bytes = 0;
762: quit_pending = 0;
763: escape_char = escape_char_arg;
764:
765: /* Initialize buffers. */
766: buffer_init(&stdin_buffer);
767: buffer_init(&stdout_buffer);
768: buffer_init(&stderr_buffer);
769:
1.15 markus 770: client_init_dispatch();
771:
1.11 markus 772: /* Set signal handlers to restore non-blocking mode. */
773: signal(SIGINT, signal_handler);
774: signal(SIGQUIT, signal_handler);
775: signal(SIGTERM, signal_handler);
776: signal(SIGPIPE, SIG_IGN);
777: if (have_pty)
778: signal(SIGWINCH, window_change_handler);
779:
780: if (have_pty)
781: enter_raw_mode();
782:
783: /* Check if we should immediately send of on stdin. */
1.16 ! markus 784: if(!compat20)
! 785: client_check_initial_eof_on_stdin();
1.11 markus 786:
787: /* Main loop of the client for the interactive session mode. */
788: while (!quit_pending) {
789: fd_set readset, writeset;
790:
1.13 markus 791: /* Process buffered packets sent by the server. */
1.11 markus 792: client_process_buffered_input_packets();
793:
1.16 ! markus 794: if (compat20 && !channel_still_open()) {
! 795: debug("!channel_still_open.");
! 796: break;
! 797: }
! 798:
1.13 markus 799: /*
800: * Make packets of buffered stdin data, and buffer them for
801: * sending to the server.
802: */
1.16 ! markus 803: if(!compat20)
! 804: client_make_packets_from_stdin_data();
1.11 markus 805:
1.13 markus 806: /*
807: * Make packets from buffered channel data, and buffer them
808: * for sending to the server.
809: */
1.11 markus 810: if (packet_not_very_much_data_to_write())
811: channel_output_poll();
812:
1.13 markus 813: /*
814: * Check if the window size has changed, and buffer a message
815: * about it to the server if so.
816: */
1.11 markus 817: client_check_window_change();
818:
819: if (quit_pending)
820: break;
821:
1.13 markus 822: /*
823: * Wait until we have something to do (something becomes
824: * available on one of the descriptors).
825: */
1.11 markus 826: client_wait_until_can_do_something(&readset, &writeset);
827:
828: if (quit_pending)
829: break;
830:
831: /* Do channel operations. */
832: channel_after_select(&readset, &writeset);
833:
1.13 markus 834: /*
835: * Process input from the connection and from stdin. Buffer
836: * any data that is available.
837: */
1.11 markus 838: client_process_input(&readset);
839:
1.13 markus 840: /*
841: * Process output to stdout and stderr. Output to the
842: * connection is processed elsewhere (above).
843: */
1.16 ! markus 844: if(!compat20)
! 845: client_process_output(&writeset);
1.11 markus 846:
1.13 markus 847: /* Send as much buffered packet data as possible to the sender. */
1.11 markus 848: if (FD_ISSET(connection_out, &writeset))
849: packet_write_poll();
850: }
851:
852: /* Terminate the session. */
853:
854: /* Stop watching for window change. */
855: if (have_pty)
856: signal(SIGWINCH, SIG_DFL);
857:
858: /* Stop listening for connections. */
859: channel_stop_listening();
860:
1.13 markus 861: /*
862: * In interactive mode (with pseudo tty) display a message indicating
863: * that the connection has been closed.
864: */
1.11 markus 865: if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
866: snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
867: buffer_append(&stderr_buffer, buf, strlen(buf));
868: stderr_bytes += strlen(buf);
869: }
870: /* Output any buffered data for stdout. */
871: while (buffer_len(&stdout_buffer) > 0) {
872: len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1.14 deraadt 873: buffer_len(&stdout_buffer));
1.11 markus 874: if (len <= 0) {
875: error("Write failed flushing stdout buffer.");
876: break;
877: }
878: buffer_consume(&stdout_buffer, len);
879: }
880:
881: /* Output any buffered data for stderr. */
882: while (buffer_len(&stderr_buffer) > 0) {
883: len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1.14 deraadt 884: buffer_len(&stderr_buffer));
1.11 markus 885: if (len <= 0) {
886: error("Write failed flushing stderr buffer.");
887: break;
888: }
889: buffer_consume(&stderr_buffer, len);
890: }
891:
892: if (have_pty)
893: leave_raw_mode();
894:
895: /* Clear and free any buffers. */
896: memset(buf, 0, sizeof(buf));
897: buffer_free(&stdin_buffer);
898: buffer_free(&stdout_buffer);
899: buffer_free(&stderr_buffer);
900:
901: /* Report bytes transferred, and transfer rates. */
902: total_time = get_current_time() - start_time;
903: debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
904: stdin_bytes, stdout_bytes, stderr_bytes, total_time);
905: if (total_time > 0)
906: debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
907: stdin_bytes / total_time, stdout_bytes / total_time,
908: stderr_bytes / total_time);
909:
910: /* Return the exit status of the program. */
911: debug("Exit status %d", exit_status);
912: return exit_status;
1.15 markus 913: }
914:
915: /*********/
916:
917: void
918: client_input_stdout_data(int type, int plen)
919: {
920: unsigned int data_len;
921: char *data = packet_get_string(&data_len);
922: packet_integrity_check(plen, 4 + data_len, type);
923: buffer_append(&stdout_buffer, data, data_len);
924: stdout_bytes += data_len;
925: memset(data, 0, data_len);
926: xfree(data);
927: }
928: void
929: client_input_stderr_data(int type, int plen)
930: {
931: unsigned int data_len;
932: char *data = packet_get_string(&data_len);
933: packet_integrity_check(plen, 4 + data_len, type);
934: buffer_append(&stderr_buffer, data, data_len);
935: stdout_bytes += data_len;
936: memset(data, 0, data_len);
937: xfree(data);
938: }
939: void
940: client_input_exit_status(int type, int plen)
941: {
942: packet_integrity_check(plen, 4, type);
943: exit_status = packet_get_int();
944: /* Acknowledge the exit. */
945: packet_start(SSH_CMSG_EXIT_CONFIRMATION);
946: packet_send();
947: /*
948: * Must wait for packet to be sent since we are
949: * exiting the loop.
950: */
951: packet_write_wait();
952: /* Flag that we want to exit. */
953: quit_pending = 1;
954: }
955:
956: void
1.16 ! markus 957: client_init_dispatch_20()
! 958: {
! 959: dispatch_init(&dispatch_protocol_error);
! 960: dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
! 961: dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
! 962: dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
! 963: dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
! 964: dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
! 965: dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
! 966: dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
! 967: dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
! 968: }
! 969: void
1.15 markus 970: client_init_dispatch_13()
971: {
972: dispatch_init(NULL);
973: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
974: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
975: dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
976: dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
977: dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
978: dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
979: dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
980: dispatch_set(SSH_SMSG_AGENT_OPEN, &auth_input_open_request);
981: dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
982: dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
983: dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
984: dispatch_set(SSH_SMSG_X11_OPEN, &x11_input_open);
985: }
986: void
987: client_init_dispatch_15()
988: {
989: client_init_dispatch_13();
990: dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
991: dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
992: }
993: void
994: client_init_dispatch()
995: {
1.16 ! markus 996: if (compat20)
! 997: client_init_dispatch_20();
! 998: else if (compat13)
1.15 markus 999: client_init_dispatch_13();
1000: else
1001: client_init_dispatch_15();
1.16 ! markus 1002: }
! 1003:
! 1004: void
! 1005: client_input_channel_req(int id, void *arg)
! 1006: {
! 1007: Channel *c = NULL;
! 1008: unsigned int len;
! 1009: int success = 0;
! 1010: int reply;
! 1011: char *rtype;
! 1012:
! 1013: rtype = packet_get_string(&len);
! 1014: reply = packet_get_char();
! 1015:
! 1016: log("session_input_channel_req: rtype %s reply %d", rtype, reply);
! 1017:
! 1018: c = channel_lookup(id);
! 1019: if (c == NULL)
! 1020: fatal("session_input_channel_req: channel %d: bad channel", id);
! 1021:
! 1022: if (session_ident == -1) {
! 1023: error("client_input_channel_req: no channel %d", id);
! 1024: } else if (id != session_ident) {
! 1025: error("client_input_channel_req: bad channel %d != %d",
! 1026: id, session_ident);
! 1027: } else if (strcmp(rtype, "exit-status") == 0) {
! 1028: success = 1;
! 1029: exit_status = packet_get_int();
! 1030: }
! 1031: if (reply) {
! 1032: packet_start(success ?
! 1033: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
! 1034: packet_put_int(c->remote_id);
! 1035: packet_send();
! 1036: }
! 1037: xfree(rtype);
! 1038: }
! 1039:
! 1040: void
! 1041: client_set_session_ident(int id)
! 1042: {
! 1043: debug("client_set_session_ident: id %d", id);
! 1044: session_ident = id;
! 1045: channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
! 1046: client_input_channel_req, (void *)0);
1.1 deraadt 1047: }
![[BACK]](/icons/back.gif){kind=icon}
Return to clientloop.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh