1 /* $OpenBSD: serverloop.c,v 1.162 2012/06/20 04:42:58 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Server main loop for handling the interactive session.
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
14 * SSH2 support by Markus Friedl.
15 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 #include <sys/types.h>
41 #include <sys/param.h>
43 #include <sys/socket.h>
44 #ifdef HAVE_SYS_TIME_H
45 # include <sys/time.h>
48 #include <netinet/in.h>
59 #include "openbsd-compat/sys-queue.h"
78 #include "auth-options.h"
79 #include "serverloop.h"
83 extern ServerOptions options;
87 extern Authctxt *the_authctxt;
88 extern int use_privsep;
90 static Buffer stdin_buffer; /* Buffer for stdin data. */
91 static Buffer stdout_buffer; /* Buffer for stdout data. */
92 static Buffer stderr_buffer; /* Buffer for stderr data. */
93 static int fdin; /* Descriptor for stdin (for writing) */
94 static int fdout; /* Descriptor for stdout (for reading);
95 May be same number as fdin. */
96 static int fderr; /* Descriptor for stderr. May be -1. */
97 static u_long stdin_bytes = 0; /* Number of bytes written to stdin. */
98 static u_long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
99 static u_long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
100 static u_long fdout_bytes = 0; /* Number of stdout bytes read from program. */
101 static int stdin_eof = 0; /* EOF message received from client. */
102 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
103 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
104 static int fdin_is_tty = 0; /* fdin points to a tty. */
105 static int connection_in; /* Connection to client (input). */
106 static int connection_out; /* Connection to client (output). */
107 static int connection_closed = 0; /* Connection to client closed. */
108 static u_int buffer_high; /* "Soft" max buffer size. */
109 static int no_more_sessions = 0; /* Disallow further sessions. */
112 * This SIGCHLD kludge is used to detect when the child exits. The server
113 * will exit after that, as soon as forwarded connections have terminated.
116 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
118 /* Cleanup on signals (!use_privsep case only) */
119 static volatile sig_atomic_t received_sigterm = 0;
122 static void server_init_dispatch(void);
125 * Returns current time in seconds from Jan 1, 1970 with the maximum
126 * available resolution.
130 get_current_time(void)
133 gettimeofday(&tv, NULL);
134 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
139 * we write to this pipe if a SIGCHLD is caught in order to avoid
140 * the race between select() and child_terminated
142 static int notify_pipe[2];
146 if (pipe(notify_pipe) < 0) {
147 error("pipe(notify_pipe) failed %s", strerror(errno));
148 } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
149 (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
150 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
151 close(notify_pipe[0]);
152 close(notify_pipe[1]);
154 set_nonblock(notify_pipe[0]);
155 set_nonblock(notify_pipe[1]);
158 notify_pipe[0] = -1; /* read end */
159 notify_pipe[1] = -1; /* write end */
164 if (notify_pipe[1] != -1)
165 write(notify_pipe[1], "", 1);
168 notify_prepare(fd_set *readset)
170 if (notify_pipe[0] != -1)
171 FD_SET(notify_pipe[0], readset);
174 notify_done(fd_set *readset)
178 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
179 while (read(notify_pipe[0], &c, 1) != -1)
180 debug2("notify_done: reading");
185 sigchld_handler(int sig)
187 int save_errno = errno;
188 child_terminated = 1;
190 mysignal(SIGCHLD, sigchld_handler);
198 sigterm_handler(int sig)
200 received_sigterm = sig;
204 * Make packets from buffered stderr data, and buffer it for sending
208 make_packets_from_stderr_data(void)
212 /* Send buffered stderr data to the client. */
213 while (buffer_len(&stderr_buffer) > 0 &&
214 packet_not_very_much_data_to_write()) {
215 len = buffer_len(&stderr_buffer);
216 if (packet_is_interactive()) {
220 /* Keep the packets at reasonable size. */
221 if (len > packet_get_maxsize())
222 len = packet_get_maxsize();
224 packet_start(SSH_SMSG_STDERR_DATA);
225 packet_put_string(buffer_ptr(&stderr_buffer), len);
227 buffer_consume(&stderr_buffer, len);
233 * Make packets from buffered stdout data, and buffer it for sending to the
237 make_packets_from_stdout_data(void)
241 /* Send buffered stdout data to the client. */
242 while (buffer_len(&stdout_buffer) > 0 &&
243 packet_not_very_much_data_to_write()) {
244 len = buffer_len(&stdout_buffer);
245 if (packet_is_interactive()) {
249 /* Keep the packets at reasonable size. */
250 if (len > packet_get_maxsize())
251 len = packet_get_maxsize();
253 packet_start(SSH_SMSG_STDOUT_DATA);
254 packet_put_string(buffer_ptr(&stdout_buffer), len);
256 buffer_consume(&stdout_buffer, len);
262 client_alive_check(void)
266 /* timeout, check to see how many we have had */
267 if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
268 logit("Timeout, client not responding.");
273 * send a bogus global/channel request with "wantreply",
274 * we should get back a failure
276 if ((channel_id = channel_find_open()) == -1) {
277 packet_start(SSH2_MSG_GLOBAL_REQUEST);
278 packet_put_cstring("keepalive@openssh.com");
279 packet_put_char(1); /* boolean: want reply */
281 channel_request_start(channel_id, "keepalive@openssh.com", 1);
287 * Sleep in select() until we can do something. This will initialize the
288 * select masks. Upon return, the masks will indicate which descriptors
289 * have data or can accept data. Optionally, a maximum time can be specified
290 * for the duration of the wait (0 = infinite).
293 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
294 u_int *nallocp, u_int max_time_milliseconds)
296 struct timeval tv, *tvp;
298 time_t minwait_secs = 0;
299 int client_alive_scheduled = 0;
300 int program_alive_scheduled = 0;
302 /* Allocate and update select() masks for channel descriptors. */
303 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
306 if (minwait_secs != 0)
307 max_time_milliseconds = MIN(max_time_milliseconds,
308 (u_int)minwait_secs * 1000);
311 * if using client_alive, set the max timeout accordingly,
312 * and indicate that this particular timeout was for client
313 * alive by setting the client_alive_scheduled flag.
315 * this could be randomized somewhat to make traffic
316 * analysis more difficult, but we're not doing it yet.
319 max_time_milliseconds == 0 && options.client_alive_interval) {
320 client_alive_scheduled = 1;
321 max_time_milliseconds = options.client_alive_interval * 1000;
326 /* wrong: bad condition XXX */
327 if (channel_not_very_much_buffered_data())
329 FD_SET(connection_in, *readsetp);
332 * Read packets from the client unless we have too much
333 * buffered stdin or channel data.
335 if (buffer_len(&stdin_buffer) < buffer_high &&
336 channel_not_very_much_buffered_data())
337 FD_SET(connection_in, *readsetp);
339 * If there is not too much data already buffered going to
340 * the client, try to get some more data from the program.
342 if (packet_not_very_much_data_to_write()) {
343 program_alive_scheduled = child_terminated;
345 FD_SET(fdout, *readsetp);
347 FD_SET(fderr, *readsetp);
350 * If we have buffered data, try to write some of that data
353 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
354 FD_SET(fdin, *writesetp);
356 notify_prepare(*readsetp);
359 * If we have buffered packet data going to the client, mark that
362 if (packet_have_data_to_write())
363 FD_SET(connection_out, *writesetp);
366 * If child has terminated and there is enough buffer space to read
367 * from it, then read as much as is available and exit.
369 if (child_terminated && packet_not_very_much_data_to_write())
370 if (max_time_milliseconds == 0 || client_alive_scheduled)
371 max_time_milliseconds = 100;
373 if (max_time_milliseconds == 0)
376 tv.tv_sec = max_time_milliseconds / 1000;
377 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
381 /* Wait for something to happen, or the timeout to expire. */
382 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
385 memset(*readsetp, 0, *nallocp);
386 memset(*writesetp, 0, *nallocp);
388 error("select: %.100s", strerror(errno));
390 if (ret == 0 && client_alive_scheduled)
391 client_alive_check();
392 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
394 FD_SET(fdout, *readsetp);
396 FD_SET(fderr, *readsetp);
400 notify_done(*readsetp);
404 * Processes input from the client and the program. Input data is stored
405 * in buffers and processed later.
408 process_input(fd_set *readset)
413 /* Read and buffer any input data from the client. */
414 if (FD_ISSET(connection_in, readset)) {
416 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
420 verbose("Connection closed by %.100s",
421 get_remote_ipaddr());
422 connection_closed = 1;
426 } else if (len < 0) {
427 if (errno != EINTR && errno != EAGAIN &&
428 errno != EWOULDBLOCK) {
429 verbose("Read error from remote host "
431 get_remote_ipaddr(), strerror(errno));
435 /* Buffer any received data. */
436 packet_process_incoming(buf, len);
443 /* Read and buffer any available stdout data from the program. */
444 if (!fdout_eof && FD_ISSET(fdout, readset)) {
446 len = read(fdout, buf, sizeof(buf));
447 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
448 errno == EWOULDBLOCK) && !child_terminated))) {
451 } else if (len <= 0) {
453 } else if ((!isatty(fdout) && len <= 0) ||
454 (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
458 buffer_append(&stdout_buffer, buf, len);
460 debug ("FD out now: %ld", fdout_bytes);
463 /* Read and buffer any available stderr data from the program. */
464 if (!fderr_eof && FD_ISSET(fderr, readset)) {
466 len = read(fderr, buf, sizeof(buf));
467 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
468 errno == EWOULDBLOCK) && !child_terminated))) {
471 } else if (len <= 0) {
473 } else if ((!isatty(fderr) && len <= 0) ||
474 (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
478 buffer_append(&stderr_buffer, buf, len);
484 * Sends data from internal buffers to client program stdin.
487 process_output(fd_set *writeset)
494 /* Write buffered data to program stdin. */
495 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
496 data = buffer_ptr(&stdin_buffer);
497 dlen = buffer_len(&stdin_buffer);
498 len = write(fdin, data, dlen);
500 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
502 } else if (len <= 0) {
506 shutdown(fdin, SHUT_WR); /* We will no longer send. */
509 /* Successful write. */
510 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
511 tcgetattr(fdin, &tio) == 0 &&
512 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
514 * Simulate echo to reduce the impact of
517 packet_send_ignore(len);
520 /* Consume the data from the buffer. */
521 buffer_consume(&stdin_buffer, len);
522 /* Update the count of bytes written to the program. */
526 /* Send any buffered packet data to the client. */
527 if (FD_ISSET(connection_out, writeset))
528 stdin_bytes += packet_write_poll();
532 * Wait until all buffered output has been sent to the client.
533 * This is used when the program terminates.
538 /* Send any buffered stdout data to the client. */
539 if (buffer_len(&stdout_buffer) > 0) {
540 packet_start(SSH_SMSG_STDOUT_DATA);
541 packet_put_string(buffer_ptr(&stdout_buffer),
542 buffer_len(&stdout_buffer));
544 /* Update the count of sent bytes. */
545 stdout_bytes += buffer_len(&stdout_buffer);
547 /* Send any buffered stderr data to the client. */
548 if (buffer_len(&stderr_buffer) > 0) {
549 packet_start(SSH_SMSG_STDERR_DATA);
550 packet_put_string(buffer_ptr(&stderr_buffer),
551 buffer_len(&stderr_buffer));
553 /* Update the count of sent bytes. */
554 stderr_bytes += buffer_len(&stderr_buffer);
556 /* Wait until all buffered data has been written to the client. */
561 process_buffered_input_packets(void)
563 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
567 * Performs the interactive session. This handles data transmission between
568 * the client and the program. Note that the notion of stdin, stdout, and
569 * stderr in this function is sort of reversed: this function writes to
570 * stdin (of the child program), and reads from stdout and stderr (of the
574 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
576 fd_set *readset = NULL, *writeset = NULL;
579 int wait_status; /* Status returned by wait(). */
580 pid_t wait_pid; /* pid returned by wait(). */
581 int waiting_termination = 0; /* Have displayed waiting close message. */
582 u_int max_time_milliseconds;
583 u_int previous_stdout_buffer_bytes;
584 u_int stdout_buffer_bytes;
587 debug("Entering interactive session.");
589 /* Initialize the SIGCHLD kludge. */
590 child_terminated = 0;
591 mysignal(SIGCHLD, sigchld_handler);
594 signal(SIGTERM, sigterm_handler);
595 signal(SIGINT, sigterm_handler);
596 signal(SIGQUIT, sigterm_handler);
599 /* Initialize our global variables. */
607 /* we don't have stderr for interactive terminal sessions, see below */
611 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
614 connection_in = packet_get_connection_in();
615 connection_out = packet_get_connection_out();
619 previous_stdout_buffer_bytes = 0;
621 /* Set approximate I/O buffer size. */
622 if (packet_is_interactive())
625 buffer_high = 64 * 1024;
628 /* Initialize max_fd to the maximum of the known file descriptors. */
629 max_fd = MAX(connection_in, connection_out);
630 max_fd = MAX(max_fd, fdin);
631 max_fd = MAX(max_fd, fdout);
633 max_fd = MAX(max_fd, fderr);
636 /* Initialize Initialize buffers. */
637 buffer_init(&stdin_buffer);
638 buffer_init(&stdout_buffer);
639 buffer_init(&stderr_buffer);
642 * If we have no separate fderr (which is the case when we have a pty
643 * - there we cannot make difference between data sent to stdout and
644 * stderr), indicate that we have seen an EOF from stderr. This way
645 * we don't need to check the descriptor everywhere.
650 server_init_dispatch();
652 /* Main loop of the server for the interactive session mode. */
655 /* Process buffered packets from the client. */
656 process_buffered_input_packets();
659 * If we have received eof, and there is no more pending
660 * input data, cause a real eof by closing fdin.
662 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
666 shutdown(fdin, SHUT_WR); /* We will no longer send. */
669 /* Make packets from buffered stderr data to send to the client. */
670 make_packets_from_stderr_data();
673 * Make packets from buffered stdout data to send to the
674 * client. If there is very little to send, this arranges to
675 * not send them now, but to wait a short while to see if we
676 * are getting more data. This is necessary, as some systems
677 * wake up readers from a pty after each separate character.
679 max_time_milliseconds = 0;
680 stdout_buffer_bytes = buffer_len(&stdout_buffer);
681 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
682 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
683 /* try again after a while */
684 max_time_milliseconds = 10;
687 make_packets_from_stdout_data();
689 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
691 /* Send channel data to the client. */
692 if (packet_not_very_much_data_to_write())
693 channel_output_poll();
696 * Bail out of the loop if the program has closed its output
697 * descriptors, and we have no more data to send to the
698 * client, and there is no pending buffered data.
700 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
701 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
702 if (!channel_still_open())
704 if (!waiting_termination) {
705 const char *s = "Waiting for forwarded connections to terminate...\r\n";
707 waiting_termination = 1;
708 buffer_append(&stderr_buffer, s, strlen(s));
710 /* Display list of open channels. */
711 cp = channel_open_message();
712 buffer_append(&stderr_buffer, cp, strlen(cp));
716 max_fd = MAX(connection_in, connection_out);
717 max_fd = MAX(max_fd, fdin);
718 max_fd = MAX(max_fd, fdout);
719 max_fd = MAX(max_fd, fderr);
720 max_fd = MAX(max_fd, notify_pipe[0]);
722 /* Sleep in select() until we can do something. */
723 wait_until_can_do_something(&readset, &writeset, &max_fd,
724 &nalloc, max_time_milliseconds);
726 if (received_sigterm) {
727 logit("Exiting on signal %d", received_sigterm);
728 /* Clean up sessions, utmp, etc. */
732 /* Process any channel events. */
733 channel_after_select(readset, writeset);
735 /* Process input from the client and from program stdout/stderr. */
736 process_input(readset);
738 /* Process output to the client and to program stdin. */
739 process_output(writeset);
746 /* Cleanup and termination code. */
748 /* Wait until all output has been sent to the client. */
751 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
752 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
754 /* Free and clear the buffers. */
755 buffer_free(&stdin_buffer);
756 buffer_free(&stdout_buffer);
757 buffer_free(&stderr_buffer);
759 /* Close the file descriptors. */
774 /* We no longer want our SIGCHLD handler to be called. */
775 mysignal(SIGCHLD, SIG_DFL);
777 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
779 packet_disconnect("wait: %.100s", strerror(errno));
781 error("Strange, wait returned pid %ld, expected %ld",
782 (long)wait_pid, (long)pid);
784 /* Check if it exited normally. */
785 if (WIFEXITED(wait_status)) {
786 /* Yes, normal exit. Get exit status and send it to the client. */
787 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
788 packet_start(SSH_SMSG_EXITSTATUS);
789 packet_put_int(WEXITSTATUS(wait_status));
794 * Wait for exit confirmation. Note that there might be
795 * other packets coming before it; however, the program has
796 * already died so we just ignore them. The client is
797 * supposed to respond with the confirmation when it receives
801 type = packet_read();
803 while (type != SSH_CMSG_EXIT_CONFIRMATION);
805 debug("Received exit confirmation.");
808 /* Check if the program terminated due to a signal. */
809 if (WIFSIGNALED(wait_status))
810 packet_disconnect("Command terminated on signal %d.",
811 WTERMSIG(wait_status));
813 /* Some weird exit cause. Just exit. */
814 packet_disconnect("wait returned status %04x.", wait_status);
819 collect_children(void)
825 /* block SIGCHLD while we check for dead children */
827 sigaddset(&nset, SIGCHLD);
828 sigprocmask(SIG_BLOCK, &nset, &oset);
829 if (child_terminated) {
830 debug("Received SIGCHLD.");
831 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
832 (pid < 0 && errno == EINTR))
834 session_close_by_pid(pid, status);
835 child_terminated = 0;
837 sigprocmask(SIG_SETMASK, &oset, NULL);
841 server_loop2(Authctxt *authctxt)
843 fd_set *readset = NULL, *writeset = NULL;
844 int rekeying = 0, max_fd, nalloc = 0;
845 double start_time, total_time;
847 debug("Entering interactive session for SSH2.");
848 start_time = get_current_time();
850 mysignal(SIGCHLD, sigchld_handler);
851 child_terminated = 0;
852 connection_in = packet_get_connection_in();
853 connection_out = packet_get_connection_out();
856 signal(SIGTERM, sigterm_handler);
857 signal(SIGINT, sigterm_handler);
858 signal(SIGQUIT, sigterm_handler);
863 max_fd = MAX(connection_in, connection_out);
864 max_fd = MAX(max_fd, notify_pipe[0]);
866 server_init_dispatch();
869 process_buffered_input_packets();
871 rekeying = (xxx_kex != NULL && !xxx_kex->done);
873 if (!rekeying && packet_not_very_much_data_to_write())
874 channel_output_poll();
875 wait_until_can_do_something(&readset, &writeset, &max_fd,
878 if (received_sigterm) {
879 logit("Exiting on signal %d", received_sigterm);
880 /* Clean up sessions, utmp, etc. */
886 channel_after_select(readset, writeset);
887 if (packet_need_rekeying()) {
888 debug("need rekeying");
890 kex_send_kexinit(xxx_kex);
893 process_input(readset);
894 if (connection_closed)
896 process_output(writeset);
905 /* free all channels, no more reads and writes */
908 /* free remaining sessions, e.g. remove wtmp entries */
909 session_destroy_all(NULL);
910 total_time = get_current_time() - start_time;
911 logit("SSH: Server;LType: Throughput;Remote: %s-%d;IN: %lu;OUT: %lu;Duration: %.1f;tPut_in: %.1f;tPut_out: %.1f",
912 get_remote_ipaddr(), get_remote_port(),
913 stdin_bytes, fdout_bytes, total_time, stdin_bytes / total_time,
914 fdout_bytes / total_time);
918 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
920 debug("Got %d/%u for keepalive", type, seq);
922 * reset timeout, since we got a sane answer from the client.
923 * even if this was generated by something other than
924 * the bogus CHANNEL_REQUEST we send for keepalives.
926 packet_set_alive_timeouts(0);
930 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
935 /* Stdin data from the client. Append it to the buffer. */
936 /* Ignore any data if the client has closed stdin. */
939 data = packet_get_string(&data_len);
941 buffer_append(&stdin_buffer, data, data_len);
942 memset(data, 0, data_len);
947 server_input_eof(int type, u_int32_t seq, void *ctxt)
950 * Eof from the client. The stdin descriptor to the
951 * program will be closed when all buffered data has
954 debug("EOF received for stdin.");
960 server_input_window_size(int type, u_int32_t seq, void *ctxt)
962 u_int row = packet_get_int();
963 u_int col = packet_get_int();
964 u_int xpixel = packet_get_int();
965 u_int ypixel = packet_get_int();
967 debug("Window change received.");
970 pty_change_window_size(fdin, row, col, xpixel, ypixel);
974 server_request_direct_tcpip(void)
977 char *target, *originator;
978 u_short target_port, originator_port;
980 target = packet_get_string(NULL);
981 target_port = packet_get_int();
982 originator = packet_get_string(NULL);
983 originator_port = packet_get_int();
986 debug("server_request_direct_tcpip: originator %s port %d, target %s "
987 "port %d", originator, originator_port, target, target_port);
989 /* XXX check permission */
990 c = channel_connect_to(target, target_port,
991 "direct-tcpip", "direct-tcpip");
1000 server_request_tun(void)
1006 mode = packet_get_int();
1008 case SSH_TUNMODE_POINTOPOINT:
1009 case SSH_TUNMODE_ETHERNET:
1012 packet_send_debug("Unsupported tunnel device mode.");
1015 if ((options.permit_tun & mode) == 0) {
1016 packet_send_debug("Server has rejected tunnel device "
1021 tun = packet_get_int();
1022 if (forced_tun_device != -1) {
1023 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1025 tun = forced_tun_device;
1027 sock = tun_open(tun, mode);
1030 if (options.hpn_disabled)
1031 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1032 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1034 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1035 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1037 #if defined(SSH_TUN_FILTER)
1038 if (mode == SSH_TUNMODE_POINTOPOINT)
1039 channel_register_filter(c->self, sys_tun_infilter,
1040 sys_tun_outfilter, NULL, NULL);
1045 packet_send_debug("Failed to open the tunnel device.");
1050 server_request_session(void)
1054 debug("input_session_request");
1057 if (no_more_sessions) {
1058 packet_disconnect("Possible attack: attempt to open a session "
1059 "after additional sessions disabled");
1063 * A server session has no fd to read or write until a
1064 * CHANNEL_REQUEST for a shell is made, so we set the type to
1065 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
1066 * CHANNEL_REQUEST messages is registered.
1068 c = channel_new("session", SSH_CHANNEL_LARVAL,
1069 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1070 0, "server-session", 1);
1071 if ((options.tcp_rcv_buf_poll) && (!options.hpn_disabled))
1072 c->dynamic_window = 1;
1073 if (session_open(the_authctxt, c->self) != 1) {
1074 debug("session open failed, free channel %d", c->self);
1078 channel_register_cleanup(c->self, session_close_by_channel, 0);
1083 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1088 u_int rmaxpack, rwindow, len;
1090 ctype = packet_get_string(&len);
1091 rchan = packet_get_int();
1092 rwindow = packet_get_int();
1093 rmaxpack = packet_get_int();
1095 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1096 ctype, rchan, rwindow, rmaxpack);
1098 if (strcmp(ctype, "session") == 0) {
1099 c = server_request_session();
1100 } else if (strcmp(ctype, "direct-tcpip") == 0) {
1101 c = server_request_direct_tcpip();
1102 } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1103 c = server_request_tun();
1106 debug("server_input_channel_open: confirm %s", ctype);
1107 c->remote_id = rchan;
1108 c->remote_window = rwindow;
1109 c->remote_maxpacket = rmaxpack;
1110 if (c->type != SSH_CHANNEL_CONNECTING) {
1111 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1112 packet_put_int(c->remote_id);
1113 packet_put_int(c->self);
1114 packet_put_int(c->local_window);
1115 packet_put_int(c->local_maxpacket);
1119 debug("server_input_channel_open: failure %s", ctype);
1120 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1121 packet_put_int(rchan);
1122 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1123 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1124 packet_put_cstring("open failed");
1125 packet_put_cstring("");
1133 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1137 int success = 0, allocated_listen_port = 0;
1139 rtype = packet_get_string(NULL);
1140 want_reply = packet_get_char();
1141 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1143 /* -R style forwarding */
1144 if (strcmp(rtype, "tcpip-forward") == 0) {
1146 char *listen_address;
1147 u_short listen_port;
1149 pw = the_authctxt->pw;
1150 if (pw == NULL || !the_authctxt->valid)
1151 fatal("server_input_global_request: no/invalid user");
1152 listen_address = packet_get_string(NULL);
1153 listen_port = (u_short)packet_get_int();
1154 debug("server_input_global_request: tcpip-forward listen %s port %d",
1155 listen_address, listen_port);
1157 /* check permissions */
1158 if (!options.allow_tcp_forwarding ||
1159 no_port_forwarding_flag ||
1160 (!want_reply && listen_port == 0)
1161 #ifndef NO_IPPORT_RESERVED_CONCEPT
1162 || (listen_port != 0 && listen_port < IPPORT_RESERVED &&
1167 packet_send_debug("Server has disabled port forwarding.");
1169 /* Start listening on the port */
1170 success = channel_setup_remote_fwd_listener(
1171 listen_address, listen_port,
1172 &allocated_listen_port, options.gateway_ports);
1174 xfree(listen_address);
1175 } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1176 char *cancel_address;
1177 u_short cancel_port;
1179 cancel_address = packet_get_string(NULL);
1180 cancel_port = (u_short)packet_get_int();
1181 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1182 cancel_address, cancel_port);
1184 success = channel_cancel_rport_listener(cancel_address,
1186 xfree(cancel_address);
1187 } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1188 no_more_sessions = 1;
1192 packet_start(success ?
1193 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1194 if (success && allocated_listen_port > 0)
1195 packet_put_int(allocated_listen_port);
1197 packet_write_wait();
1203 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1206 int id, reply, success = 0;
1209 id = packet_get_int();
1210 rtype = packet_get_string(NULL);
1211 reply = packet_get_char();
1213 debug("server_input_channel_req: channel %d request %s reply %d",
1216 if ((c = channel_lookup(id)) == NULL)
1217 packet_disconnect("server_input_channel_req: "
1218 "unknown channel %d", id);
1219 if (!strcmp(rtype, "eow@openssh.com")) {
1222 } else if ((c->type == SSH_CHANNEL_LARVAL ||
1223 c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1224 success = session_input_channel_req(c, rtype);
1226 packet_start(success ?
1227 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1228 packet_put_int(c->remote_id);
1235 server_init_dispatch_20(void)
1237 debug("server_init_dispatch_20");
1238 dispatch_init(&dispatch_protocol_error);
1239 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1240 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1241 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1242 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1243 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1244 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1245 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1246 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1247 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1248 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1250 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1251 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1252 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1253 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1255 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1258 server_init_dispatch_13(void)
1260 debug("server_init_dispatch_13");
1261 dispatch_init(NULL);
1262 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1263 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1264 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1265 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1266 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1267 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1268 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1269 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1270 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1273 server_init_dispatch_15(void)
1275 server_init_dispatch_13();
1276 debug("server_init_dispatch_15");
1277 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1278 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1281 server_init_dispatch(void)
1284 server_init_dispatch_20();
1286 server_init_dispatch_13();
1288 server_init_dispatch_15();