2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Server main loop for handling the interactive session.
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
13 * SSH2 support by Markus Friedl.
14 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 RCSID("$OpenBSD: serverloop.c,v 1.113 2003/11/18 00:40:05 dtucker Exp $");
54 #include "auth-options.h"
55 #include "serverloop.h"
59 extern ServerOptions options;
63 extern Authctxt *the_authctxt;
65 static Buffer stdin_buffer; /* Buffer for stdin data. */
66 static Buffer stdout_buffer; /* Buffer for stdout data. */
67 static Buffer stderr_buffer; /* Buffer for stderr data. */
68 static int fdin; /* Descriptor for stdin (for writing) */
69 static int fdout; /* Descriptor for stdout (for reading);
70 May be same number as fdin. */
71 static int fderr; /* Descriptor for stderr. May be -1. */
72 static long stdin_bytes = 0; /* Number of bytes written to stdin. */
73 static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
74 static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
75 static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
76 static int stdin_eof = 0; /* EOF message received from client. */
77 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
78 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
79 static int fdin_is_tty = 0; /* fdin points to a tty. */
80 static int connection_in; /* Connection to client (input). */
81 static int connection_out; /* Connection to client (output). */
82 static int connection_closed = 0; /* Connection to client closed. */
83 static u_int buffer_high; /* "Soft" max buffer size. */
84 static int client_alive_timeouts = 0;
87 * This SIGCHLD kludge is used to detect when the child exits. The server
88 * will exit after that, as soon as forwarded connections have terminated.
91 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
94 static void server_init_dispatch(void);
97 * we write to this pipe if a SIGCHLD is caught in order to avoid
98 * the race between select() and child_terminated
100 static int notify_pipe[2];
104 if (pipe(notify_pipe) < 0) {
105 error("pipe(notify_pipe) failed %s", strerror(errno));
106 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
107 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
108 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
109 close(notify_pipe[0]);
110 close(notify_pipe[1]);
112 set_nonblock(notify_pipe[0]);
113 set_nonblock(notify_pipe[1]);
116 notify_pipe[0] = -1; /* read end */
117 notify_pipe[1] = -1; /* write end */
122 if (notify_pipe[1] != -1)
123 write(notify_pipe[1], "", 1);
126 notify_prepare(fd_set *readset)
128 if (notify_pipe[0] != -1)
129 FD_SET(notify_pipe[0], readset);
132 notify_done(fd_set *readset)
136 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
137 while (read(notify_pipe[0], &c, 1) != -1)
138 debug2("notify_done: reading");
142 sigchld_handler(int sig)
144 int save_errno = errno;
145 debug("Received SIGCHLD.");
146 child_terminated = 1;
148 mysignal(SIGCHLD, sigchld_handler);
155 * Make packets from buffered stderr data, and buffer it for sending
159 make_packets_from_stderr_data(void)
163 /* Send buffered stderr data to the client. */
164 while (buffer_len(&stderr_buffer) > 0 &&
165 packet_not_very_much_data_to_write()) {
166 len = buffer_len(&stderr_buffer);
167 if (packet_is_interactive()) {
171 /* Keep the packets at reasonable size. */
172 if (len > packet_get_maxsize())
173 len = packet_get_maxsize();
175 packet_start(SSH_SMSG_STDERR_DATA);
176 packet_put_string(buffer_ptr(&stderr_buffer), len);
178 buffer_consume(&stderr_buffer, len);
184 * Make packets from buffered stdout data, and buffer it for sending to the
188 make_packets_from_stdout_data(void)
192 /* Send buffered stdout data to the client. */
193 while (buffer_len(&stdout_buffer) > 0 &&
194 packet_not_very_much_data_to_write()) {
195 len = buffer_len(&stdout_buffer);
196 if (packet_is_interactive()) {
200 /* Keep the packets at reasonable size. */
201 if (len > packet_get_maxsize())
202 len = packet_get_maxsize();
204 packet_start(SSH_SMSG_STDOUT_DATA);
205 packet_put_string(buffer_ptr(&stdout_buffer), len);
207 buffer_consume(&stdout_buffer, len);
213 client_alive_check(void)
215 static int had_channel = 0;
218 id = channel_find_open();
222 packet_disconnect("No open channels after timeout!");
226 /* timeout, check to see how many we have had */
227 if (++client_alive_timeouts > options.client_alive_count_max)
228 packet_disconnect("Timeout, your session not responding.");
231 * send a bogus channel request with "wantreply",
232 * we should get back a failure
234 channel_request_start(id, "keepalive@openssh.com", 1);
239 * Sleep in select() until we can do something. This will initialize the
240 * select masks. Upon return, the masks will indicate which descriptors
241 * have data or can accept data. Optionally, a maximum time can be specified
242 * for the duration of the wait (0 = infinite).
245 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
246 int *nallocp, u_int max_time_milliseconds)
248 struct timeval tv, *tvp;
250 int client_alive_scheduled = 0;
253 * if using client_alive, set the max timeout accordingly,
254 * and indicate that this particular timeout was for client
255 * alive by setting the client_alive_scheduled flag.
257 * this could be randomized somewhat to make traffic
258 * analysis more difficult, but we're not doing it yet.
261 max_time_milliseconds == 0 && options.client_alive_interval) {
262 client_alive_scheduled = 1;
263 max_time_milliseconds = options.client_alive_interval * 1000;
266 /* Allocate and update select() masks for channel descriptors. */
267 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
271 /* wrong: bad condition XXX */
272 if (channel_not_very_much_buffered_data())
274 FD_SET(connection_in, *readsetp);
277 * Read packets from the client unless we have too much
278 * buffered stdin or channel data.
280 if (buffer_len(&stdin_buffer) < buffer_high &&
281 channel_not_very_much_buffered_data())
282 FD_SET(connection_in, *readsetp);
284 * If there is not too much data already buffered going to
285 * the client, try to get some more data from the program.
287 if (packet_not_very_much_data_to_write()) {
289 FD_SET(fdout, *readsetp);
291 FD_SET(fderr, *readsetp);
294 * If we have buffered data, try to write some of that data
297 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
298 FD_SET(fdin, *writesetp);
300 notify_prepare(*readsetp);
303 * If we have buffered packet data going to the client, mark that
306 if (packet_have_data_to_write())
307 FD_SET(connection_out, *writesetp);
310 * If child has terminated and there is enough buffer space to read
311 * from it, then read as much as is available and exit.
313 if (child_terminated && packet_not_very_much_data_to_write())
314 if (max_time_milliseconds == 0 || client_alive_scheduled)
315 max_time_milliseconds = 100;
317 if (max_time_milliseconds == 0)
320 tv.tv_sec = max_time_milliseconds / 1000;
321 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
325 /* Wait for something to happen, or the timeout to expire. */
326 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
329 memset(*readsetp, 0, *nallocp);
330 memset(*writesetp, 0, *nallocp);
332 error("select: %.100s", strerror(errno));
333 } else if (ret == 0 && client_alive_scheduled)
334 client_alive_check();
336 notify_done(*readsetp);
340 * Processes input from the client and the program. Input data is stored
341 * in buffers and processed later.
344 process_input(fd_set * readset)
349 /* Read and buffer any input data from the client. */
350 if (FD_ISSET(connection_in, readset)) {
351 len = read(connection_in, buf, sizeof(buf));
353 verbose("Connection closed by %.100s",
354 get_remote_ipaddr());
355 connection_closed = 1;
359 } else if (len < 0) {
360 if (errno != EINTR && errno != EAGAIN) {
361 verbose("Read error from remote host "
363 get_remote_ipaddr(), strerror(errno));
367 /* Buffer any received data. */
368 packet_process_incoming(buf, len);
374 /* Read and buffer any available stdout data from the program. */
375 if (!fdout_eof && FD_ISSET(fdout, readset)) {
376 len = read(fdout, buf, sizeof(buf));
377 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
379 } else if (len <= 0) {
382 buffer_append(&stdout_buffer, buf, len);
386 /* Read and buffer any available stderr data from the program. */
387 if (!fderr_eof && FD_ISSET(fderr, readset)) {
388 len = read(fderr, buf, sizeof(buf));
389 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
391 } else if (len <= 0) {
394 buffer_append(&stderr_buffer, buf, len);
400 * Sends data from internal buffers to client program stdin.
403 process_output(fd_set * writeset)
410 /* Write buffered data to program stdin. */
411 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
412 data = buffer_ptr(&stdin_buffer);
413 dlen = buffer_len(&stdin_buffer);
414 len = write(fdin, data, dlen);
415 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
417 } else if (len <= 0) {
421 shutdown(fdin, SHUT_WR); /* We will no longer send. */
424 /* Successful write. */
425 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
426 tcgetattr(fdin, &tio) == 0 &&
427 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
429 * Simulate echo to reduce the impact of
432 packet_send_ignore(len);
435 /* Consume the data from the buffer. */
436 buffer_consume(&stdin_buffer, len);
437 /* Update the count of bytes written to the program. */
441 /* Send any buffered packet data to the client. */
442 if (FD_ISSET(connection_out, writeset))
447 * Wait until all buffered output has been sent to the client.
448 * This is used when the program terminates.
453 /* Send any buffered stdout data to the client. */
454 if (buffer_len(&stdout_buffer) > 0) {
455 packet_start(SSH_SMSG_STDOUT_DATA);
456 packet_put_string(buffer_ptr(&stdout_buffer),
457 buffer_len(&stdout_buffer));
459 /* Update the count of sent bytes. */
460 stdout_bytes += buffer_len(&stdout_buffer);
462 /* Send any buffered stderr data to the client. */
463 if (buffer_len(&stderr_buffer) > 0) {
464 packet_start(SSH_SMSG_STDERR_DATA);
465 packet_put_string(buffer_ptr(&stderr_buffer),
466 buffer_len(&stderr_buffer));
468 /* Update the count of sent bytes. */
469 stderr_bytes += buffer_len(&stderr_buffer);
471 /* Wait until all buffered data has been written to the client. */
476 process_buffered_input_packets(void)
478 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
482 * Performs the interactive session. This handles data transmission between
483 * the client and the program. Note that the notion of stdin, stdout, and
484 * stderr in this function is sort of reversed: this function writes to
485 * stdin (of the child program), and reads from stdout and stderr (of the
489 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
491 fd_set *readset = NULL, *writeset = NULL;
492 int max_fd = 0, nalloc = 0;
493 int wait_status; /* Status returned by wait(). */
494 pid_t wait_pid; /* pid returned by wait(). */
495 int waiting_termination = 0; /* Have displayed waiting close message. */
496 u_int max_time_milliseconds;
497 u_int previous_stdout_buffer_bytes;
498 u_int stdout_buffer_bytes;
501 debug("Entering interactive session.");
503 /* Initialize the SIGCHLD kludge. */
504 child_terminated = 0;
505 mysignal(SIGCHLD, sigchld_handler);
507 /* Initialize our global variables. */
515 /* we don't have stderr for interactive terminal sessions, see below */
519 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
522 connection_in = packet_get_connection_in();
523 connection_out = packet_get_connection_out();
527 previous_stdout_buffer_bytes = 0;
529 /* Set approximate I/O buffer size. */
530 if (packet_is_interactive())
533 buffer_high = 64 * 1024;
536 /* Initialize max_fd to the maximum of the known file descriptors. */
537 max_fd = MAX(connection_in, connection_out);
538 max_fd = MAX(max_fd, fdin);
539 max_fd = MAX(max_fd, fdout);
541 max_fd = MAX(max_fd, fderr);
544 /* Initialize Initialize buffers. */
545 buffer_init(&stdin_buffer);
546 buffer_init(&stdout_buffer);
547 buffer_init(&stderr_buffer);
550 * If we have no separate fderr (which is the case when we have a pty
551 * - there we cannot make difference between data sent to stdout and
552 * stderr), indicate that we have seen an EOF from stderr. This way
553 * we don\'t need to check the descriptor everywhere.
558 server_init_dispatch();
560 /* Main loop of the server for the interactive session mode. */
563 /* Process buffered packets from the client. */
564 process_buffered_input_packets();
567 * If we have received eof, and there is no more pending
568 * input data, cause a real eof by closing fdin.
570 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
574 shutdown(fdin, SHUT_WR); /* We will no longer send. */
577 /* Make packets from buffered stderr data to send to the client. */
578 make_packets_from_stderr_data();
581 * Make packets from buffered stdout data to send to the
582 * client. If there is very little to send, this arranges to
583 * not send them now, but to wait a short while to see if we
584 * are getting more data. This is necessary, as some systems
585 * wake up readers from a pty after each separate character.
587 max_time_milliseconds = 0;
588 stdout_buffer_bytes = buffer_len(&stdout_buffer);
589 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
590 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
591 /* try again after a while */
592 max_time_milliseconds = 10;
595 make_packets_from_stdout_data();
597 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
599 /* Send channel data to the client. */
600 if (packet_not_very_much_data_to_write())
601 channel_output_poll();
604 * Bail out of the loop if the program has closed its output
605 * descriptors, and we have no more data to send to the
606 * client, and there is no pending buffered data.
608 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
609 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
610 if (!channel_still_open())
612 if (!waiting_termination) {
613 const char *s = "Waiting for forwarded connections to terminate...\r\n";
615 waiting_termination = 1;
616 buffer_append(&stderr_buffer, s, strlen(s));
618 /* Display list of open channels. */
619 cp = channel_open_message();
620 buffer_append(&stderr_buffer, cp, strlen(cp));
624 max_fd = MAX(connection_in, connection_out);
625 max_fd = MAX(max_fd, fdin);
626 max_fd = MAX(max_fd, fdout);
627 max_fd = MAX(max_fd, fderr);
628 max_fd = MAX(max_fd, notify_pipe[0]);
630 /* Sleep in select() until we can do something. */
631 wait_until_can_do_something(&readset, &writeset, &max_fd,
632 &nalloc, max_time_milliseconds);
634 /* Process any channel events. */
635 channel_after_select(readset, writeset);
637 /* Process input from the client and from program stdout/stderr. */
638 process_input(readset);
640 /* Process output to the client and to program stdin. */
641 process_output(writeset);
648 /* Cleanup and termination code. */
650 /* Wait until all output has been sent to the client. */
653 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
654 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
656 /* Free and clear the buffers. */
657 buffer_free(&stdin_buffer);
658 buffer_free(&stdout_buffer);
659 buffer_free(&stderr_buffer);
661 /* Close the file descriptors. */
676 /* We no longer want our SIGCHLD handler to be called. */
677 mysignal(SIGCHLD, SIG_DFL);
679 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
681 packet_disconnect("wait: %.100s", strerror(errno));
683 error("Strange, wait returned pid %ld, expected %ld",
684 (long)wait_pid, (long)pid);
686 /* Check if it exited normally. */
687 if (WIFEXITED(wait_status)) {
688 /* Yes, normal exit. Get exit status and send it to the client. */
689 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
690 packet_start(SSH_SMSG_EXITSTATUS);
691 packet_put_int(WEXITSTATUS(wait_status));
696 * Wait for exit confirmation. Note that there might be
697 * other packets coming before it; however, the program has
698 * already died so we just ignore them. The client is
699 * supposed to respond with the confirmation when it receives
703 type = packet_read();
705 while (type != SSH_CMSG_EXIT_CONFIRMATION);
707 debug("Received exit confirmation.");
710 /* Check if the program terminated due to a signal. */
711 if (WIFSIGNALED(wait_status))
712 packet_disconnect("Command terminated on signal %d.",
713 WTERMSIG(wait_status));
715 /* Some weird exit cause. Just exit. */
716 packet_disconnect("wait returned status %04x.", wait_status);
721 collect_children(void)
727 /* block SIGCHLD while we check for dead children */
729 sigaddset(&nset, SIGCHLD);
730 sigprocmask(SIG_BLOCK, &nset, &oset);
731 if (child_terminated) {
732 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
733 (pid < 0 && errno == EINTR))
735 session_close_by_pid(pid, status);
736 child_terminated = 0;
738 sigprocmask(SIG_SETMASK, &oset, NULL);
742 server_loop2(Authctxt *authctxt)
744 fd_set *readset = NULL, *writeset = NULL;
745 int rekeying = 0, max_fd, nalloc = 0;
747 debug("Entering interactive session for SSH2.");
749 mysignal(SIGCHLD, sigchld_handler);
750 child_terminated = 0;
751 connection_in = packet_get_connection_in();
752 connection_out = packet_get_connection_out();
756 max_fd = MAX(connection_in, connection_out);
757 max_fd = MAX(max_fd, notify_pipe[0]);
759 server_init_dispatch();
762 process_buffered_input_packets();
764 rekeying = (xxx_kex != NULL && !xxx_kex->done);
766 if (!rekeying && packet_not_very_much_data_to_write())
767 channel_output_poll();
768 wait_until_can_do_something(&readset, &writeset, &max_fd,
773 channel_after_select(readset, writeset);
774 if (packet_need_rekeying()) {
775 debug("need rekeying");
777 kex_send_kexinit(xxx_kex);
780 process_input(readset);
781 if (connection_closed)
783 process_output(writeset);
792 /* free all channels, no more reads and writes */
795 /* free remaining sessions, e.g. remove wtmp entries */
796 session_destroy_all(NULL);
800 server_input_channel_failure(int type, u_int32_t seq, void *ctxt)
802 debug("Got CHANNEL_FAILURE for keepalive");
804 * reset timeout, since we got a sane answer from the client.
805 * even if this was generated by something other than
806 * the bogus CHANNEL_REQUEST we send for keepalives.
808 client_alive_timeouts = 0;
813 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
818 /* Stdin data from the client. Append it to the buffer. */
819 /* Ignore any data if the client has closed stdin. */
822 data = packet_get_string(&data_len);
824 buffer_append(&stdin_buffer, data, data_len);
825 memset(data, 0, data_len);
830 server_input_eof(int type, u_int32_t seq, void *ctxt)
833 * Eof from the client. The stdin descriptor to the
834 * program will be closed when all buffered data has
837 debug("EOF received for stdin.");
843 server_input_window_size(int type, u_int32_t seq, void *ctxt)
845 int row = packet_get_int();
846 int col = packet_get_int();
847 int xpixel = packet_get_int();
848 int ypixel = packet_get_int();
850 debug("Window change received.");
853 pty_change_window_size(fdin, row, col, xpixel, ypixel);
857 server_request_direct_tcpip(char *ctype)
861 char *target, *originator;
862 int target_port, originator_port;
864 target = packet_get_string(NULL);
865 target_port = packet_get_int();
866 originator = packet_get_string(NULL);
867 originator_port = packet_get_int();
870 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
871 originator, originator_port, target, target_port);
873 /* XXX check permission */
874 sock = channel_connect_to(target, target_port);
879 c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
880 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
881 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
886 server_request_session(char *ctype)
890 debug("input_session_request");
893 * A server session has no fd to read or write until a
894 * CHANNEL_REQUEST for a shell is made, so we set the type to
895 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
896 * CHANNEL_REQUEST messages is registered.
898 c = channel_new(ctype, SSH_CHANNEL_LARVAL,
899 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
900 0, "server-session", 1);
901 if (session_open(the_authctxt, c->self) != 1) {
902 debug("session open failed, free channel %d", c->self);
906 channel_register_cleanup(c->self, session_close_by_channel);
911 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
916 u_int rmaxpack, rwindow, len;
918 ctype = packet_get_string(&len);
919 rchan = packet_get_int();
920 rwindow = packet_get_int();
921 rmaxpack = packet_get_int();
923 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
924 ctype, rchan, rwindow, rmaxpack);
926 if (strcmp(ctype, "session") == 0) {
927 c = server_request_session(ctype);
928 } else if (strcmp(ctype, "direct-tcpip") == 0) {
929 c = server_request_direct_tcpip(ctype);
932 debug("server_input_channel_open: confirm %s", ctype);
933 c->remote_id = rchan;
934 c->remote_window = rwindow;
935 c->remote_maxpacket = rmaxpack;
936 if (c->type != SSH_CHANNEL_CONNECTING) {
937 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
938 packet_put_int(c->remote_id);
939 packet_put_int(c->self);
940 packet_put_int(c->local_window);
941 packet_put_int(c->local_maxpacket);
945 debug("server_input_channel_open: failure %s", ctype);
946 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
947 packet_put_int(rchan);
948 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
949 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
950 packet_put_cstring("open failed");
951 packet_put_cstring("");
959 server_input_global_request(int type, u_int32_t seq, void *ctxt)
965 rtype = packet_get_string(NULL);
966 want_reply = packet_get_char();
967 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
969 /* -R style forwarding */
970 if (strcmp(rtype, "tcpip-forward") == 0) {
972 char *listen_address;
975 pw = the_authctxt->pw;
976 if (pw == NULL || !the_authctxt->valid)
977 fatal("server_input_global_request: no/invalid user");
978 listen_address = packet_get_string(NULL);
979 listen_port = (u_short)packet_get_int();
980 debug("server_input_global_request: tcpip-forward listen %s port %d",
981 listen_address, listen_port);
983 /* check permissions */
984 if (!options.allow_tcp_forwarding ||
985 no_port_forwarding_flag
986 #ifndef NO_IPPORT_RESERVED_CONCEPT
987 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
991 packet_send_debug("Server has disabled port forwarding.");
993 /* Start listening on the port */
994 success = channel_setup_remote_fwd_listener(
995 listen_address, listen_port, options.gateway_ports);
997 xfree(listen_address);
1000 packet_start(success ?
1001 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1003 packet_write_wait();
1008 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1011 int id, reply, success = 0;
1014 id = packet_get_int();
1015 rtype = packet_get_string(NULL);
1016 reply = packet_get_char();
1018 debug("server_input_channel_req: channel %d request %s reply %d",
1021 if ((c = channel_lookup(id)) == NULL)
1022 packet_disconnect("server_input_channel_req: "
1023 "unknown channel %d", id);
1024 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1025 success = session_input_channel_req(c, rtype);
1027 packet_start(success ?
1028 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1029 packet_put_int(c->remote_id);
1036 server_init_dispatch_20(void)
1038 debug("server_init_dispatch_20");
1039 dispatch_init(&dispatch_protocol_error);
1040 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1041 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1042 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1043 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1044 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1045 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1046 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1047 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1048 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1049 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1051 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure);
1053 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1056 server_init_dispatch_13(void)
1058 debug("server_init_dispatch_13");
1059 dispatch_init(NULL);
1060 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1061 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1062 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1063 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1064 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1065 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1066 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1067 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1068 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1071 server_init_dispatch_15(void)
1073 server_init_dispatch_13();
1074 debug("server_init_dispatch_15");
1075 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1076 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1079 server_init_dispatch(void)
1082 server_init_dispatch_20();
1084 server_init_dispatch_13();
1086 server_init_dispatch_15();