1 /* $OpenBSD: serverloop.c,v 1.148 2008/02/22 20:44:02 dtucker 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>
77 #include "auth-options.h"
78 #include "serverloop.h"
81 extern ServerOptions options;
85 extern Authctxt *the_authctxt;
86 extern int use_privsep;
88 static Buffer stdin_buffer; /* Buffer for stdin data. */
89 static Buffer stdout_buffer; /* Buffer for stdout data. */
90 static Buffer stderr_buffer; /* Buffer for stderr data. */
91 static int fdin; /* Descriptor for stdin (for writing) */
92 static int fdout; /* Descriptor for stdout (for reading);
93 May be same number as fdin. */
94 static int fderr; /* Descriptor for stderr. May be -1. */
95 static u_long stdin_bytes = 0; /* Number of bytes written to stdin. */
96 static u_long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
97 static u_long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
98 static u_long fdout_bytes = 0; /* Number of stdout bytes read from program. */
99 static int stdin_eof = 0; /* EOF message received from client. */
100 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
101 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
102 static int fdin_is_tty = 0; /* fdin points to a tty. */
103 static int connection_in; /* Connection to client (input). */
104 static int connection_out; /* Connection to client (output). */
105 static int connection_closed = 0; /* Connection to client closed. */
106 static u_int buffer_high; /* "Soft" max buffer size. */
109 * This SIGCHLD kludge is used to detect when the child exits. The server
110 * will exit after that, as soon as forwarded connections have terminated.
113 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
115 /* Cleanup on signals (!use_privsep case only) */
116 static volatile sig_atomic_t received_sigterm = 0;
119 static void server_init_dispatch(void);
122 * Returns current time in seconds from Jan 1, 1970 with the maximum
123 * available resolution.
127 get_current_time(void)
130 gettimeofday(&tv, NULL);
131 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
136 * we write to this pipe if a SIGCHLD is caught in order to avoid
137 * the race between select() and child_terminated
139 static int notify_pipe[2];
143 if (pipe(notify_pipe) < 0) {
144 error("pipe(notify_pipe) failed %s", strerror(errno));
145 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
146 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
147 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
148 close(notify_pipe[0]);
149 close(notify_pipe[1]);
151 set_nonblock(notify_pipe[0]);
152 set_nonblock(notify_pipe[1]);
155 notify_pipe[0] = -1; /* read end */
156 notify_pipe[1] = -1; /* write end */
161 if (notify_pipe[1] != -1)
162 write(notify_pipe[1], "", 1);
165 notify_prepare(fd_set *readset)
167 if (notify_pipe[0] != -1)
168 FD_SET(notify_pipe[0], readset);
171 notify_done(fd_set *readset)
175 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
176 while (read(notify_pipe[0], &c, 1) != -1)
177 debug2("notify_done: reading");
182 sigchld_handler(int sig)
184 int save_errno = errno;
185 child_terminated = 1;
187 mysignal(SIGCHLD, sigchld_handler);
195 sigterm_handler(int sig)
197 received_sigterm = sig;
201 * Make packets from buffered stderr data, and buffer it for sending
205 make_packets_from_stderr_data(void)
209 /* Send buffered stderr data to the client. */
210 while (buffer_len(&stderr_buffer) > 0 &&
211 packet_not_very_much_data_to_write()) {
212 len = buffer_len(&stderr_buffer);
213 if (packet_is_interactive()) {
217 /* Keep the packets at reasonable size. */
218 if (len > packet_get_maxsize())
219 len = packet_get_maxsize();
221 packet_start(SSH_SMSG_STDERR_DATA);
222 packet_put_string(buffer_ptr(&stderr_buffer), len);
224 buffer_consume(&stderr_buffer, len);
230 * Make packets from buffered stdout data, and buffer it for sending to the
234 make_packets_from_stdout_data(void)
238 /* Send buffered stdout data to the client. */
239 while (buffer_len(&stdout_buffer) > 0 &&
240 packet_not_very_much_data_to_write()) {
241 len = buffer_len(&stdout_buffer);
242 if (packet_is_interactive()) {
246 /* Keep the packets at reasonable size. */
247 if (len > packet_get_maxsize())
248 len = packet_get_maxsize();
250 packet_start(SSH_SMSG_STDOUT_DATA);
251 packet_put_string(buffer_ptr(&stdout_buffer), len);
253 buffer_consume(&stdout_buffer, len);
259 client_alive_check(void)
263 /* timeout, check to see how many we have had */
264 if (++keep_alive_timeouts > options.client_alive_count_max) {
265 logit("Timeout, client not responding.");
270 * send a bogus global/channel request with "wantreply",
271 * we should get back a failure
273 if ((channel_id = channel_find_open()) == -1) {
274 packet_start(SSH2_MSG_GLOBAL_REQUEST);
275 packet_put_cstring("keepalive@openssh.com");
276 packet_put_char(1); /* boolean: want reply */
278 channel_request_start(channel_id, "keepalive@openssh.com", 1);
284 * Sleep in select() until we can do something. This will initialize the
285 * select masks. Upon return, the masks will indicate which descriptors
286 * have data or can accept data. Optionally, a maximum time can be specified
287 * for the duration of the wait (0 = infinite).
290 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
291 u_int *nallocp, u_int max_time_milliseconds)
293 struct timeval tv, *tvp;
295 int client_alive_scheduled = 0;
296 int program_alive_scheduled = 0;
299 * if using client_alive, set the max timeout accordingly,
300 * and indicate that this particular timeout was for client
301 * alive by setting the client_alive_scheduled flag.
303 * this could be randomized somewhat to make traffic
304 * analysis more difficult, but we're not doing it yet.
307 max_time_milliseconds == 0 && options.client_alive_interval) {
308 client_alive_scheduled = 1;
309 max_time_milliseconds = options.client_alive_interval * 1000;
312 /* Allocate and update select() masks for channel descriptors. */
313 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
317 /* wrong: bad condition XXX */
318 if (channel_not_very_much_buffered_data())
320 FD_SET(connection_in, *readsetp);
323 * Read packets from the client unless we have too much
324 * buffered stdin or channel data.
326 if (buffer_len(&stdin_buffer) < buffer_high &&
327 channel_not_very_much_buffered_data())
328 FD_SET(connection_in, *readsetp);
330 * If there is not too much data already buffered going to
331 * the client, try to get some more data from the program.
333 if (packet_not_very_much_data_to_write()) {
334 program_alive_scheduled = child_terminated;
336 FD_SET(fdout, *readsetp);
338 FD_SET(fderr, *readsetp);
341 * If we have buffered data, try to write some of that data
344 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
345 FD_SET(fdin, *writesetp);
347 notify_prepare(*readsetp);
350 * If we have buffered packet data going to the client, mark that
353 if (packet_have_data_to_write())
354 FD_SET(connection_out, *writesetp);
357 * If child has terminated and there is enough buffer space to read
358 * from it, then read as much as is available and exit.
360 if (child_terminated && packet_not_very_much_data_to_write())
361 if (max_time_milliseconds == 0 || client_alive_scheduled)
362 max_time_milliseconds = 100;
364 if (max_time_milliseconds == 0)
367 tv.tv_sec = max_time_milliseconds / 1000;
368 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
372 /* Wait for something to happen, or the timeout to expire. */
373 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
376 memset(*readsetp, 0, *nallocp);
377 memset(*writesetp, 0, *nallocp);
379 error("select: %.100s", strerror(errno));
381 if (ret == 0 && client_alive_scheduled)
382 client_alive_check();
383 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
385 FD_SET(fdout, *readsetp);
387 FD_SET(fderr, *readsetp);
391 notify_done(*readsetp);
395 * Processes input from the client and the program. Input data is stored
396 * in buffers and processed later.
399 process_input(fd_set *readset)
404 /* Read and buffer any input data from the client. */
405 if (FD_ISSET(connection_in, readset)) {
406 len = read(connection_in, buf, sizeof(buf));
408 verbose("Connection closed by %.100s",
409 get_remote_ipaddr());
410 connection_closed = 1;
414 } else if (len < 0) {
415 if (errno != EINTR && errno != EAGAIN) {
416 verbose("Read error from remote host "
418 get_remote_ipaddr(), strerror(errno));
422 /* Buffer any received data. */
423 packet_process_incoming(buf, len);
430 /* Read and buffer any available stdout data from the program. */
431 if (!fdout_eof && FD_ISSET(fdout, readset)) {
433 len = read(fdout, buf, sizeof(buf));
434 if (len < 0 && (errno == EINTR ||
435 (errno == EAGAIN && !child_terminated))) {
438 } else if (len <= 0) {
440 } else if ((!isatty(fdout) && len <= 0) ||
441 (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
445 buffer_append(&stdout_buffer, buf, len);
447 debug ("FD out now: %ld", fdout_bytes);
450 /* Read and buffer any available stderr data from the program. */
451 if (!fderr_eof && FD_ISSET(fderr, readset)) {
453 len = read(fderr, buf, sizeof(buf));
454 if (len < 0 && (errno == EINTR ||
455 (errno == EAGAIN && !child_terminated))) {
458 } else if (len <= 0) {
460 } else if ((!isatty(fderr) && len <= 0) ||
461 (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
465 buffer_append(&stderr_buffer, buf, len);
471 * Sends data from internal buffers to client program stdin.
474 process_output(fd_set *writeset)
481 /* Write buffered data to program stdin. */
482 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
483 data = buffer_ptr(&stdin_buffer);
484 dlen = buffer_len(&stdin_buffer);
485 len = write(fdin, data, dlen);
486 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
488 } else if (len <= 0) {
492 shutdown(fdin, SHUT_WR); /* We will no longer send. */
495 /* Successful write. */
496 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
497 tcgetattr(fdin, &tio) == 0 &&
498 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
500 * Simulate echo to reduce the impact of
503 packet_send_ignore(len);
506 /* Consume the data from the buffer. */
507 buffer_consume(&stdin_buffer, len);
508 /* Update the count of bytes written to the program. */
512 /* Send any buffered packet data to the client. */
513 if (FD_ISSET(connection_out, writeset))
514 stdin_bytes += packet_write_poll();
518 * Wait until all buffered output has been sent to the client.
519 * This is used when the program terminates.
524 /* Send any buffered stdout data to the client. */
525 if (buffer_len(&stdout_buffer) > 0) {
526 packet_start(SSH_SMSG_STDOUT_DATA);
527 packet_put_string(buffer_ptr(&stdout_buffer),
528 buffer_len(&stdout_buffer));
530 /* Update the count of sent bytes. */
531 stdout_bytes += buffer_len(&stdout_buffer);
533 /* Send any buffered stderr data to the client. */
534 if (buffer_len(&stderr_buffer) > 0) {
535 packet_start(SSH_SMSG_STDERR_DATA);
536 packet_put_string(buffer_ptr(&stderr_buffer),
537 buffer_len(&stderr_buffer));
539 /* Update the count of sent bytes. */
540 stderr_bytes += buffer_len(&stderr_buffer);
542 /* Wait until all buffered data has been written to the client. */
547 process_buffered_input_packets(void)
549 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
553 * Performs the interactive session. This handles data transmission between
554 * the client and the program. Note that the notion of stdin, stdout, and
555 * stderr in this function is sort of reversed: this function writes to
556 * stdin (of the child program), and reads from stdout and stderr (of the
560 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
562 fd_set *readset = NULL, *writeset = NULL;
565 int wait_status; /* Status returned by wait(). */
566 pid_t wait_pid; /* pid returned by wait(). */
567 int waiting_termination = 0; /* Have displayed waiting close message. */
568 u_int max_time_milliseconds;
569 u_int previous_stdout_buffer_bytes;
570 u_int stdout_buffer_bytes;
573 debug("Entering interactive session.");
575 /* Initialize the SIGCHLD kludge. */
576 child_terminated = 0;
577 mysignal(SIGCHLD, sigchld_handler);
580 signal(SIGTERM, sigterm_handler);
581 signal(SIGINT, sigterm_handler);
582 signal(SIGQUIT, sigterm_handler);
585 /* Initialize our global variables. */
593 /* we don't have stderr for interactive terminal sessions, see below */
597 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
600 connection_in = packet_get_connection_in();
601 connection_out = packet_get_connection_out();
605 previous_stdout_buffer_bytes = 0;
607 /* Set approximate I/O buffer size. */
608 if (packet_is_interactive())
611 buffer_high = 64 * 1024;
614 /* Initialize max_fd to the maximum of the known file descriptors. */
615 max_fd = MAX(connection_in, connection_out);
616 max_fd = MAX(max_fd, fdin);
617 max_fd = MAX(max_fd, fdout);
619 max_fd = MAX(max_fd, fderr);
622 /* Initialize Initialize buffers. */
623 buffer_init(&stdin_buffer);
624 buffer_init(&stdout_buffer);
625 buffer_init(&stderr_buffer);
628 * If we have no separate fderr (which is the case when we have a pty
629 * - there we cannot make difference between data sent to stdout and
630 * stderr), indicate that we have seen an EOF from stderr. This way
631 * we don't need to check the descriptor everywhere.
636 server_init_dispatch();
638 /* Main loop of the server for the interactive session mode. */
641 /* Process buffered packets from the client. */
642 process_buffered_input_packets();
645 * If we have received eof, and there is no more pending
646 * input data, cause a real eof by closing fdin.
648 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
652 shutdown(fdin, SHUT_WR); /* We will no longer send. */
655 /* Make packets from buffered stderr data to send to the client. */
656 make_packets_from_stderr_data();
659 * Make packets from buffered stdout data to send to the
660 * client. If there is very little to send, this arranges to
661 * not send them now, but to wait a short while to see if we
662 * are getting more data. This is necessary, as some systems
663 * wake up readers from a pty after each separate character.
665 max_time_milliseconds = 0;
666 stdout_buffer_bytes = buffer_len(&stdout_buffer);
667 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
668 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
669 /* try again after a while */
670 max_time_milliseconds = 10;
673 make_packets_from_stdout_data();
675 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
677 /* Send channel data to the client. */
678 if (packet_not_very_much_data_to_write())
679 channel_output_poll();
682 * Bail out of the loop if the program has closed its output
683 * descriptors, and we have no more data to send to the
684 * client, and there is no pending buffered data.
686 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
687 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
688 if (!channel_still_open())
690 if (!waiting_termination) {
691 const char *s = "Waiting for forwarded connections to terminate...\r\n";
693 waiting_termination = 1;
694 buffer_append(&stderr_buffer, s, strlen(s));
696 /* Display list of open channels. */
697 cp = channel_open_message();
698 buffer_append(&stderr_buffer, cp, strlen(cp));
702 max_fd = MAX(connection_in, connection_out);
703 max_fd = MAX(max_fd, fdin);
704 max_fd = MAX(max_fd, fdout);
705 max_fd = MAX(max_fd, fderr);
706 max_fd = MAX(max_fd, notify_pipe[0]);
708 /* Sleep in select() until we can do something. */
709 wait_until_can_do_something(&readset, &writeset, &max_fd,
710 &nalloc, max_time_milliseconds);
712 if (received_sigterm) {
713 logit("Exiting on signal %d", received_sigterm);
714 /* Clean up sessions, utmp, etc. */
718 /* Process any channel events. */
719 channel_after_select(readset, writeset);
721 /* Process input from the client and from program stdout/stderr. */
722 process_input(readset);
724 /* Process output to the client and to program stdin. */
725 process_output(writeset);
732 /* Cleanup and termination code. */
734 /* Wait until all output has been sent to the client. */
737 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
738 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
740 /* Free and clear the buffers. */
741 buffer_free(&stdin_buffer);
742 buffer_free(&stdout_buffer);
743 buffer_free(&stderr_buffer);
745 /* Close the file descriptors. */
760 /* We no longer want our SIGCHLD handler to be called. */
761 mysignal(SIGCHLD, SIG_DFL);
763 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
765 packet_disconnect("wait: %.100s", strerror(errno));
767 error("Strange, wait returned pid %ld, expected %ld",
768 (long)wait_pid, (long)pid);
770 /* Check if it exited normally. */
771 if (WIFEXITED(wait_status)) {
772 /* Yes, normal exit. Get exit status and send it to the client. */
773 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
774 packet_start(SSH_SMSG_EXITSTATUS);
775 packet_put_int(WEXITSTATUS(wait_status));
780 * Wait for exit confirmation. Note that there might be
781 * other packets coming before it; however, the program has
782 * already died so we just ignore them. The client is
783 * supposed to respond with the confirmation when it receives
787 type = packet_read();
789 while (type != SSH_CMSG_EXIT_CONFIRMATION);
791 debug("Received exit confirmation.");
794 /* Check if the program terminated due to a signal. */
795 if (WIFSIGNALED(wait_status))
796 packet_disconnect("Command terminated on signal %d.",
797 WTERMSIG(wait_status));
799 /* Some weird exit cause. Just exit. */
800 packet_disconnect("wait returned status %04x.", wait_status);
805 collect_children(void)
811 /* block SIGCHLD while we check for dead children */
813 sigaddset(&nset, SIGCHLD);
814 sigprocmask(SIG_BLOCK, &nset, &oset);
815 if (child_terminated) {
816 debug("Received SIGCHLD.");
817 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
818 (pid < 0 && errno == EINTR))
820 session_close_by_pid(pid, status);
821 child_terminated = 0;
823 sigprocmask(SIG_SETMASK, &oset, NULL);
827 server_loop2(Authctxt *authctxt)
829 fd_set *readset = NULL, *writeset = NULL;
830 int rekeying = 0, max_fd, nalloc = 0;
831 double start_time, total_time;
833 debug("Entering interactive session for SSH2.");
834 start_time = get_current_time();
836 mysignal(SIGCHLD, sigchld_handler);
837 child_terminated = 0;
838 connection_in = packet_get_connection_in();
839 connection_out = packet_get_connection_out();
842 signal(SIGTERM, sigterm_handler);
843 signal(SIGINT, sigterm_handler);
844 signal(SIGQUIT, sigterm_handler);
849 max_fd = MAX(connection_in, connection_out);
850 max_fd = MAX(max_fd, notify_pipe[0]);
852 server_init_dispatch();
855 process_buffered_input_packets();
857 rekeying = (xxx_kex != NULL && !xxx_kex->done);
859 if (!rekeying && packet_not_very_much_data_to_write())
860 channel_output_poll();
861 wait_until_can_do_something(&readset, &writeset, &max_fd,
864 if (received_sigterm) {
865 logit("Exiting on signal %d", received_sigterm);
866 /* Clean up sessions, utmp, etc. */
872 channel_after_select(readset, writeset);
873 if (packet_need_rekeying()) {
874 debug("need rekeying");
876 kex_send_kexinit(xxx_kex);
879 process_input(readset);
880 if (connection_closed)
882 process_output(writeset);
891 /* free all channels, no more reads and writes */
894 /* free remaining sessions, e.g. remove wtmp entries */
895 session_destroy_all(NULL);
896 total_time = get_current_time() - start_time;
897 logit("SSH: Server;LType: Throughput;Remote: %s-%d;IN: %lu;OUT: %lu;Duration: %.1f;tPut_in: %.1f;tPut_out: %.1f",
898 get_remote_ipaddr(), get_remote_port(),
899 stdin_bytes, fdout_bytes, total_time, stdin_bytes / total_time,
900 fdout_bytes / total_time);
904 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
906 debug("Got %d/%u for keepalive", type, seq);
908 * reset timeout, since we got a sane answer from the client.
909 * even if this was generated by something other than
910 * the bogus CHANNEL_REQUEST we send for keepalives.
912 keep_alive_timeouts = 0;
916 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
921 /* Stdin data from the client. Append it to the buffer. */
922 /* Ignore any data if the client has closed stdin. */
925 data = packet_get_string(&data_len);
927 buffer_append(&stdin_buffer, data, data_len);
928 memset(data, 0, data_len);
933 server_input_eof(int type, u_int32_t seq, void *ctxt)
936 * Eof from the client. The stdin descriptor to the
937 * program will be closed when all buffered data has
940 debug("EOF received for stdin.");
946 server_input_window_size(int type, u_int32_t seq, void *ctxt)
948 u_int row = packet_get_int();
949 u_int col = packet_get_int();
950 u_int xpixel = packet_get_int();
951 u_int ypixel = packet_get_int();
953 debug("Window change received.");
956 pty_change_window_size(fdin, row, col, xpixel, ypixel);
960 server_request_direct_tcpip(void)
964 char *target, *originator;
965 int target_port, originator_port;
967 target = packet_get_string(NULL);
968 target_port = packet_get_int();
969 originator = packet_get_string(NULL);
970 originator_port = packet_get_int();
973 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
974 originator, originator_port, target, target_port);
976 /* XXX check permission */
977 sock = channel_connect_to(target, target_port);
982 if (options.hpn_disabled)
983 c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
984 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
985 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
987 c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
988 sock, sock, -1, options.hpn_buffer_size,
989 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
994 server_request_tun(void)
1000 mode = packet_get_int();
1002 case SSH_TUNMODE_POINTOPOINT:
1003 case SSH_TUNMODE_ETHERNET:
1006 packet_send_debug("Unsupported tunnel device mode.");
1009 if ((options.permit_tun & mode) == 0) {
1010 packet_send_debug("Server has rejected tunnel device "
1015 tun = packet_get_int();
1016 if (forced_tun_device != -1) {
1017 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1019 tun = forced_tun_device;
1021 sock = tun_open(tun, mode);
1024 if (options.hpn_disabled)
1025 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1026 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1028 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1029 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1031 #if defined(SSH_TUN_FILTER)
1032 if (mode == SSH_TUNMODE_POINTOPOINT)
1033 channel_register_filter(c->self, sys_tun_infilter,
1039 packet_send_debug("Failed to open the tunnel device.");
1044 server_request_session(void)
1048 debug("input_session_request");
1051 * A server session has no fd to read or write until a
1052 * CHANNEL_REQUEST for a shell is made, so we set the type to
1053 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
1054 * CHANNEL_REQUEST messages is registered.
1056 c = channel_new("session", SSH_CHANNEL_LARVAL,
1057 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1058 0, "server-session", 1);
1059 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled))
1060 c->dynamic_window = 1;
1061 if (session_open(the_authctxt, c->self) != 1) {
1062 debug("session open failed, free channel %d", c->self);
1066 channel_register_cleanup(c->self, session_close_by_channel, 0);
1071 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1076 u_int rmaxpack, rwindow, len;
1078 ctype = packet_get_string(&len);
1079 rchan = packet_get_int();
1080 rwindow = packet_get_int();
1081 rmaxpack = packet_get_int();
1083 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1084 ctype, rchan, rwindow, rmaxpack);
1086 if (strcmp(ctype, "session") == 0) {
1087 c = server_request_session();
1088 } else if (strcmp(ctype, "direct-tcpip") == 0) {
1089 c = server_request_direct_tcpip();
1090 } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1091 c = server_request_tun();
1094 debug("server_input_channel_open: confirm %s", ctype);
1095 c->remote_id = rchan;
1096 c->remote_window = rwindow;
1097 c->remote_maxpacket = rmaxpack;
1098 if (c->type != SSH_CHANNEL_CONNECTING) {
1099 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1100 packet_put_int(c->remote_id);
1101 packet_put_int(c->self);
1102 packet_put_int(c->local_window);
1103 packet_put_int(c->local_maxpacket);
1107 debug("server_input_channel_open: failure %s", ctype);
1108 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1109 packet_put_int(rchan);
1110 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1111 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1112 packet_put_cstring("open failed");
1113 packet_put_cstring("");
1121 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1127 rtype = packet_get_string(NULL);
1128 want_reply = packet_get_char();
1129 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1131 /* -R style forwarding */
1132 if (strcmp(rtype, "tcpip-forward") == 0) {
1134 char *listen_address;
1135 u_short listen_port;
1137 pw = the_authctxt->pw;
1138 if (pw == NULL || !the_authctxt->valid)
1139 fatal("server_input_global_request: no/invalid user");
1140 listen_address = packet_get_string(NULL);
1141 listen_port = (u_short)packet_get_int();
1142 debug("server_input_global_request: tcpip-forward listen %s port %d",
1143 listen_address, listen_port);
1145 /* check permissions */
1146 if (!options.allow_tcp_forwarding ||
1147 no_port_forwarding_flag
1148 #ifndef NO_IPPORT_RESERVED_CONCEPT
1149 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
1153 packet_send_debug("Server has disabled port forwarding.");
1155 /* Start listening on the port */
1156 success = channel_setup_remote_fwd_listener(
1157 listen_address, listen_port, options.gateway_ports,
1158 options.hpn_disabled, options.hpn_buffer_size);
1160 xfree(listen_address);
1161 } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1162 char *cancel_address;
1163 u_short cancel_port;
1165 cancel_address = packet_get_string(NULL);
1166 cancel_port = (u_short)packet_get_int();
1167 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1168 cancel_address, cancel_port);
1170 success = channel_cancel_rport_listener(cancel_address,
1172 xfree(cancel_address);
1175 packet_start(success ?
1176 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1178 packet_write_wait();
1184 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1187 int id, reply, success = 0;
1190 id = packet_get_int();
1191 rtype = packet_get_string(NULL);
1192 reply = packet_get_char();
1194 debug("server_input_channel_req: channel %d request %s reply %d",
1197 if ((c = channel_lookup(id)) == NULL)
1198 packet_disconnect("server_input_channel_req: "
1199 "unknown channel %d", id);
1200 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1201 success = session_input_channel_req(c, rtype);
1203 packet_start(success ?
1204 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1205 packet_put_int(c->remote_id);
1212 server_init_dispatch_20(void)
1214 debug("server_init_dispatch_20");
1215 dispatch_init(&dispatch_protocol_error);
1216 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1217 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1218 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1219 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1220 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1221 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1222 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1223 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1224 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1225 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1227 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1228 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1229 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1231 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1234 server_init_dispatch_13(void)
1236 debug("server_init_dispatch_13");
1237 dispatch_init(NULL);
1238 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1239 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1240 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1241 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1242 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1243 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1244 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1245 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1246 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1249 server_init_dispatch_15(void)
1251 server_init_dispatch_13();
1252 debug("server_init_dispatch_15");
1253 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1254 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1257 server_init_dispatch(void)
1260 server_init_dispatch_20();
1262 server_init_dispatch_13();
1264 server_init_dispatch_15();