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 1.104 2002/09/19 16:03:15 stevesk Exp $");
39 RCSID("$FreeBSD: src/crypto/openssh/serverloop.c,v 1.1.1.1.2.7 2003/02/03 17:31:07 des Exp $");
40 RCSID("$DragonFly: src/crypto/openssh/Attic/serverloop.c,v 1.2 2003/06/17 04:24:36 dillon Exp $");
56 #include "auth-options.h"
57 #include "serverloop.h"
61 extern ServerOptions options;
65 static Authctxt *xxx_authctxt;
67 static Buffer stdin_buffer; /* Buffer for stdin data. */
68 static Buffer stdout_buffer; /* Buffer for stdout data. */
69 static Buffer stderr_buffer; /* Buffer for stderr data. */
70 static int fdin; /* Descriptor for stdin (for writing) */
71 static int fdout; /* Descriptor for stdout (for reading);
72 May be same number as fdin. */
73 static int fderr; /* Descriptor for stderr. May be -1. */
74 static long stdin_bytes = 0; /* Number of bytes written to stdin. */
75 static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
76 static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
77 static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
78 static int stdin_eof = 0; /* EOF message received from client. */
79 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
80 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
81 static int fdin_is_tty = 0; /* fdin points to a tty. */
82 static int connection_in; /* Connection to client (input). */
83 static int connection_out; /* Connection to client (output). */
84 static int connection_closed = 0; /* Connection to client closed. */
85 static u_int buffer_high; /* "Soft" max buffer size. */
86 static int client_alive_timeouts = 0;
89 * This SIGCHLD kludge is used to detect when the child exits. The server
90 * will exit after that, as soon as forwarded connections have terminated.
93 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
96 static void server_init_dispatch(void);
99 * we write to this pipe if a SIGCHLD is caught in order to avoid
100 * the race between select() and child_terminated
102 static int notify_pipe[2];
106 if (pipe(notify_pipe) < 0) {
107 error("pipe(notify_pipe) failed %s", strerror(errno));
108 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
109 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
110 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
111 close(notify_pipe[0]);
112 close(notify_pipe[1]);
114 set_nonblock(notify_pipe[0]);
115 set_nonblock(notify_pipe[1]);
118 notify_pipe[0] = -1; /* read end */
119 notify_pipe[1] = -1; /* write end */
124 if (notify_pipe[1] != -1)
125 write(notify_pipe[1], "", 1);
128 notify_prepare(fd_set *readset)
130 if (notify_pipe[0] != -1)
131 FD_SET(notify_pipe[0], readset);
134 notify_done(fd_set *readset)
138 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
139 while (read(notify_pipe[0], &c, 1) != -1)
140 debug2("notify_done: reading");
144 sigchld_handler(int sig)
146 int save_errno = errno;
147 debug("Received SIGCHLD.");
148 child_terminated = 1;
150 mysignal(SIGCHLD, sigchld_handler);
157 * Make packets from buffered stderr data, and buffer it for sending
161 make_packets_from_stderr_data(void)
165 /* Send buffered stderr data to the client. */
166 while (buffer_len(&stderr_buffer) > 0 &&
167 packet_not_very_much_data_to_write()) {
168 len = buffer_len(&stderr_buffer);
169 if (packet_is_interactive()) {
173 /* Keep the packets at reasonable size. */
174 if (len > packet_get_maxsize())
175 len = packet_get_maxsize();
177 packet_start(SSH_SMSG_STDERR_DATA);
178 packet_put_string(buffer_ptr(&stderr_buffer), len);
180 buffer_consume(&stderr_buffer, len);
186 * Make packets from buffered stdout data, and buffer it for sending to the
190 make_packets_from_stdout_data(void)
194 /* Send buffered stdout data to the client. */
195 while (buffer_len(&stdout_buffer) > 0 &&
196 packet_not_very_much_data_to_write()) {
197 len = buffer_len(&stdout_buffer);
198 if (packet_is_interactive()) {
202 /* Keep the packets at reasonable size. */
203 if (len > packet_get_maxsize())
204 len = packet_get_maxsize();
206 packet_start(SSH_SMSG_STDOUT_DATA);
207 packet_put_string(buffer_ptr(&stdout_buffer), len);
209 buffer_consume(&stdout_buffer, len);
215 client_alive_check(void)
217 static int had_channel = 0;
220 id = channel_find_open();
224 packet_disconnect("No open channels after timeout!");
228 /* timeout, check to see how many we have had */
229 if (++client_alive_timeouts > options.client_alive_count_max)
230 packet_disconnect("Timeout, your session not responding.");
233 * send a bogus channel request with "wantreply",
234 * we should get back a failure
236 channel_request_start(id, "keepalive@openssh.com", 1);
241 * Sleep in select() until we can do something. This will initialize the
242 * select masks. Upon return, the masks will indicate which descriptors
243 * have data or can accept data. Optionally, a maximum time can be specified
244 * for the duration of the wait (0 = infinite).
247 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
248 int *nallocp, u_int max_time_milliseconds)
250 struct timeval tv, *tvp;
252 int client_alive_scheduled = 0;
255 * if using client_alive, set the max timeout accordingly,
256 * and indicate that this particular timeout was for client
257 * alive by setting the client_alive_scheduled flag.
259 * this could be randomized somewhat to make traffic
260 * analysis more difficult, but we're not doing it yet.
263 max_time_milliseconds == 0 && options.client_alive_interval) {
264 client_alive_scheduled = 1;
265 max_time_milliseconds = options.client_alive_interval * 1000;
268 /* Allocate and update select() masks for channel descriptors. */
269 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
273 /* wrong: bad condition XXX */
274 if (channel_not_very_much_buffered_data())
276 FD_SET(connection_in, *readsetp);
279 * Read packets from the client unless we have too much
280 * buffered stdin or channel data.
282 if (buffer_len(&stdin_buffer) < buffer_high &&
283 channel_not_very_much_buffered_data())
284 FD_SET(connection_in, *readsetp);
286 * If there is not too much data already buffered going to
287 * the client, try to get some more data from the program.
289 if (packet_not_very_much_data_to_write()) {
291 FD_SET(fdout, *readsetp);
293 FD_SET(fderr, *readsetp);
296 * If we have buffered data, try to write some of that data
299 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
300 FD_SET(fdin, *writesetp);
302 notify_prepare(*readsetp);
305 * If we have buffered packet data going to the client, mark that
308 if (packet_have_data_to_write())
309 FD_SET(connection_out, *writesetp);
312 * If child has terminated and there is enough buffer space to read
313 * from it, then read as much as is available and exit.
315 if (child_terminated && packet_not_very_much_data_to_write())
316 if (max_time_milliseconds == 0 || client_alive_scheduled)
317 max_time_milliseconds = 100;
319 if (max_time_milliseconds == 0)
322 tv.tv_sec = max_time_milliseconds / 1000;
323 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
327 /* Wait for something to happen, or the timeout to expire. */
328 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
331 memset(*readsetp, 0, *nallocp);
332 memset(*writesetp, 0, *nallocp);
334 error("select: %.100s", strerror(errno));
335 } else if (ret == 0 && client_alive_scheduled)
336 client_alive_check();
338 notify_done(*readsetp);
342 * Processes input from the client and the program. Input data is stored
343 * in buffers and processed later.
346 process_input(fd_set * readset)
351 /* Read and buffer any input data from the client. */
352 if (FD_ISSET(connection_in, readset)) {
353 len = read(connection_in, buf, sizeof(buf));
355 verbose("Connection closed by %.100s",
356 get_remote_ipaddr());
357 connection_closed = 1;
361 } else if (len < 0) {
362 if (errno != EINTR && errno != EAGAIN) {
363 verbose("Read error from remote host "
365 get_remote_ipaddr(), strerror(errno));
369 /* Buffer any received data. */
370 packet_process_incoming(buf, len);
376 /* Read and buffer any available stdout data from the program. */
377 if (!fdout_eof && FD_ISSET(fdout, readset)) {
378 len = read(fdout, buf, sizeof(buf));
379 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
381 } else if (len <= 0) {
384 buffer_append(&stdout_buffer, buf, len);
388 /* Read and buffer any available stderr data from the program. */
389 if (!fderr_eof && FD_ISSET(fderr, readset)) {
390 len = read(fderr, buf, sizeof(buf));
391 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
393 } else if (len <= 0) {
396 buffer_append(&stderr_buffer, buf, len);
402 * Sends data from internal buffers to client program stdin.
405 process_output(fd_set * writeset)
412 /* Write buffered data to program stdin. */
413 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
414 data = buffer_ptr(&stdin_buffer);
415 dlen = buffer_len(&stdin_buffer);
416 len = write(fdin, data, dlen);
417 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
419 } else if (len <= 0) {
423 shutdown(fdin, SHUT_WR); /* We will no longer send. */
426 /* Successful write. */
427 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
428 tcgetattr(fdin, &tio) == 0 &&
429 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
431 * Simulate echo to reduce the impact of
434 packet_send_ignore(len);
437 /* Consume the data from the buffer. */
438 buffer_consume(&stdin_buffer, len);
439 /* Update the count of bytes written to the program. */
443 /* Send any buffered packet data to the client. */
444 if (FD_ISSET(connection_out, writeset))
449 * Wait until all buffered output has been sent to the client.
450 * This is used when the program terminates.
455 /* Send any buffered stdout data to the client. */
456 if (buffer_len(&stdout_buffer) > 0) {
457 packet_start(SSH_SMSG_STDOUT_DATA);
458 packet_put_string(buffer_ptr(&stdout_buffer),
459 buffer_len(&stdout_buffer));
461 /* Update the count of sent bytes. */
462 stdout_bytes += buffer_len(&stdout_buffer);
464 /* Send any buffered stderr data to the client. */
465 if (buffer_len(&stderr_buffer) > 0) {
466 packet_start(SSH_SMSG_STDERR_DATA);
467 packet_put_string(buffer_ptr(&stderr_buffer),
468 buffer_len(&stderr_buffer));
470 /* Update the count of sent bytes. */
471 stderr_bytes += buffer_len(&stderr_buffer);
473 /* Wait until all buffered data has been written to the client. */
478 process_buffered_input_packets(void)
480 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
484 * Performs the interactive session. This handles data transmission between
485 * the client and the program. Note that the notion of stdin, stdout, and
486 * stderr in this function is sort of reversed: this function writes to
487 * stdin (of the child program), and reads from stdout and stderr (of the
491 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
493 fd_set *readset = NULL, *writeset = NULL;
494 int max_fd = 0, nalloc = 0;
495 int wait_status; /* Status returned by wait(). */
496 pid_t wait_pid; /* pid returned by wait(). */
497 int waiting_termination = 0; /* Have displayed waiting close message. */
498 u_int max_time_milliseconds;
499 u_int previous_stdout_buffer_bytes;
500 u_int stdout_buffer_bytes;
503 debug("Entering interactive session.");
505 /* Initialize the SIGCHLD kludge. */
506 child_terminated = 0;
507 mysignal(SIGCHLD, sigchld_handler);
509 /* Initialize our global variables. */
517 /* we don't have stderr for interactive terminal sessions, see below */
521 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
524 connection_in = packet_get_connection_in();
525 connection_out = packet_get_connection_out();
529 previous_stdout_buffer_bytes = 0;
531 /* Set approximate I/O buffer size. */
532 if (packet_is_interactive())
535 buffer_high = 64 * 1024;
538 /* Initialize max_fd to the maximum of the known file descriptors. */
539 max_fd = MAX(connection_in, connection_out);
540 max_fd = MAX(max_fd, fdin);
541 max_fd = MAX(max_fd, fdout);
543 max_fd = MAX(max_fd, fderr);
546 /* Initialize Initialize buffers. */
547 buffer_init(&stdin_buffer);
548 buffer_init(&stdout_buffer);
549 buffer_init(&stderr_buffer);
552 * If we have no separate fderr (which is the case when we have a pty
553 * - there we cannot make difference between data sent to stdout and
554 * stderr), indicate that we have seen an EOF from stderr. This way
555 * we don\'t need to check the descriptor everywhere.
560 server_init_dispatch();
562 /* Main loop of the server for the interactive session mode. */
565 /* Process buffered packets from the client. */
566 process_buffered_input_packets();
569 * If we have received eof, and there is no more pending
570 * input data, cause a real eof by closing fdin.
572 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
576 shutdown(fdin, SHUT_WR); /* We will no longer send. */
579 /* Make packets from buffered stderr data to send to the client. */
580 make_packets_from_stderr_data();
583 * Make packets from buffered stdout data to send to the
584 * client. If there is very little to send, this arranges to
585 * not send them now, but to wait a short while to see if we
586 * are getting more data. This is necessary, as some systems
587 * wake up readers from a pty after each separate character.
589 max_time_milliseconds = 0;
590 stdout_buffer_bytes = buffer_len(&stdout_buffer);
591 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
592 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
593 /* try again after a while */
594 max_time_milliseconds = 10;
597 make_packets_from_stdout_data();
599 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
601 /* Send channel data to the client. */
602 if (packet_not_very_much_data_to_write())
603 channel_output_poll();
606 * Bail out of the loop if the program has closed its output
607 * descriptors, and we have no more data to send to the
608 * client, and there is no pending buffered data.
610 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
611 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
612 if (!channel_still_open())
614 if (!waiting_termination) {
615 const char *s = "Waiting for forwarded connections to terminate...\r\n";
617 waiting_termination = 1;
618 buffer_append(&stderr_buffer, s, strlen(s));
620 /* Display list of open channels. */
621 cp = channel_open_message();
622 buffer_append(&stderr_buffer, cp, strlen(cp));
626 max_fd = MAX(connection_in, connection_out);
627 max_fd = MAX(max_fd, fdin);
628 max_fd = MAX(max_fd, fdout);
629 max_fd = MAX(max_fd, fderr);
630 max_fd = MAX(max_fd, notify_pipe[0]);
632 /* Sleep in select() until we can do something. */
633 wait_until_can_do_something(&readset, &writeset, &max_fd,
634 &nalloc, max_time_milliseconds);
636 /* Process any channel events. */
637 channel_after_select(readset, writeset);
639 /* Process input from the client and from program stdout/stderr. */
640 process_input(readset);
642 /* Process output to the client and to program stdin. */
643 process_output(writeset);
650 /* Cleanup and termination code. */
652 /* Wait until all output has been sent to the client. */
655 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
656 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
658 /* Free and clear the buffers. */
659 buffer_free(&stdin_buffer);
660 buffer_free(&stdout_buffer);
661 buffer_free(&stderr_buffer);
663 /* Close the file descriptors. */
678 /* We no longer want our SIGCHLD handler to be called. */
679 mysignal(SIGCHLD, SIG_DFL);
681 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
683 packet_disconnect("wait: %.100s", strerror(errno));
685 error("Strange, wait returned pid %ld, expected %ld",
686 (long)wait_pid, (long)pid);
688 /* Check if it exited normally. */
689 if (WIFEXITED(wait_status)) {
690 /* Yes, normal exit. Get exit status and send it to the client. */
691 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
692 packet_start(SSH_SMSG_EXITSTATUS);
693 packet_put_int(WEXITSTATUS(wait_status));
698 * Wait for exit confirmation. Note that there might be
699 * other packets coming before it; however, the program has
700 * already died so we just ignore them. The client is
701 * supposed to respond with the confirmation when it receives
705 type = packet_read();
707 while (type != SSH_CMSG_EXIT_CONFIRMATION);
709 debug("Received exit confirmation.");
712 /* Check if the program terminated due to a signal. */
713 if (WIFSIGNALED(wait_status))
714 packet_disconnect("Command terminated on signal %d.",
715 WTERMSIG(wait_status));
717 /* Some weird exit cause. Just exit. */
718 packet_disconnect("wait returned status %04x.", wait_status);
723 collect_children(void)
729 /* block SIGCHLD while we check for dead children */
731 sigaddset(&nset, SIGCHLD);
732 sigprocmask(SIG_BLOCK, &nset, &oset);
733 if (child_terminated) {
734 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
735 (pid < 0 && errno == EINTR))
737 session_close_by_pid(pid, status);
738 child_terminated = 0;
740 sigprocmask(SIG_SETMASK, &oset, NULL);
744 server_loop2(Authctxt *authctxt)
746 fd_set *readset = NULL, *writeset = NULL;
747 int rekeying = 0, max_fd, nalloc = 0;
749 debug("Entering interactive session for SSH2.");
751 mysignal(SIGCHLD, sigchld_handler);
752 child_terminated = 0;
753 connection_in = packet_get_connection_in();
754 connection_out = packet_get_connection_out();
758 max_fd = MAX(connection_in, connection_out);
759 max_fd = MAX(max_fd, notify_pipe[0]);
761 xxx_authctxt = authctxt;
763 server_init_dispatch();
766 process_buffered_input_packets();
768 rekeying = (xxx_kex != NULL && !xxx_kex->done);
770 if (!rekeying && packet_not_very_much_data_to_write())
771 channel_output_poll();
772 wait_until_can_do_something(&readset, &writeset, &max_fd,
777 channel_after_select(readset, writeset);
778 process_input(readset);
779 if (connection_closed)
781 process_output(writeset);
790 /* free all channels, no more reads and writes */
793 /* free remaining sessions, e.g. remove wtmp entries */
794 session_destroy_all(NULL);
798 server_input_channel_failure(int type, u_int32_t seq, void *ctxt)
800 debug("Got CHANNEL_FAILURE for keepalive");
802 * reset timeout, since we got a sane answer from the client.
803 * even if this was generated by something other than
804 * the bogus CHANNEL_REQUEST we send for keepalives.
806 client_alive_timeouts = 0;
811 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
816 /* Stdin data from the client. Append it to the buffer. */
817 /* Ignore any data if the client has closed stdin. */
820 data = packet_get_string(&data_len);
822 buffer_append(&stdin_buffer, data, data_len);
823 memset(data, 0, data_len);
828 server_input_eof(int type, u_int32_t seq, void *ctxt)
831 * Eof from the client. The stdin descriptor to the
832 * program will be closed when all buffered data has
835 debug("EOF received for stdin.");
841 server_input_window_size(int type, u_int32_t seq, void *ctxt)
843 int row = packet_get_int();
844 int col = packet_get_int();
845 int xpixel = packet_get_int();
846 int ypixel = packet_get_int();
848 debug("Window change received.");
851 pty_change_window_size(fdin, row, col, xpixel, ypixel);
855 server_request_direct_tcpip(char *ctype)
859 char *target, *originator;
860 int target_port, originator_port;
862 target = packet_get_string(NULL);
863 target_port = packet_get_int();
864 originator = packet_get_string(NULL);
865 originator_port = packet_get_int();
868 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
869 originator, originator_port, target, target_port);
871 /* XXX check permission */
872 sock = channel_connect_to(target, target_port);
877 c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
878 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
879 CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1);
884 server_request_session(char *ctype)
888 debug("input_session_request");
891 * A server session has no fd to read or write until a
892 * CHANNEL_REQUEST for a shell is made, so we set the type to
893 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
894 * CHANNEL_REQUEST messages is registered.
896 c = channel_new(ctype, SSH_CHANNEL_LARVAL,
897 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
898 0, xstrdup("server-session"), 1);
899 if (session_open(xxx_authctxt, c->self) != 1) {
900 debug("session open failed, free channel %d", c->self);
904 channel_register_cleanup(c->self, session_close_by_channel);
909 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
914 u_int rmaxpack, rwindow, len;
916 ctype = packet_get_string(&len);
917 rchan = packet_get_int();
918 rwindow = packet_get_int();
919 rmaxpack = packet_get_int();
921 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
922 ctype, rchan, rwindow, rmaxpack);
924 if (strcmp(ctype, "session") == 0) {
925 c = server_request_session(ctype);
926 } else if (strcmp(ctype, "direct-tcpip") == 0) {
927 c = server_request_direct_tcpip(ctype);
930 debug("server_input_channel_open: confirm %s", ctype);
931 c->remote_id = rchan;
932 c->remote_window = rwindow;
933 c->remote_maxpacket = rmaxpack;
934 if (c->type != SSH_CHANNEL_CONNECTING) {
935 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
936 packet_put_int(c->remote_id);
937 packet_put_int(c->self);
938 packet_put_int(c->local_window);
939 packet_put_int(c->local_maxpacket);
943 debug("server_input_channel_open: failure %s", ctype);
944 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
945 packet_put_int(rchan);
946 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
947 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
948 packet_put_cstring("open failed");
949 packet_put_cstring("");
957 server_input_global_request(int type, u_int32_t seq, void *ctxt)
963 rtype = packet_get_string(NULL);
964 want_reply = packet_get_char();
965 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
967 /* -R style forwarding */
968 if (strcmp(rtype, "tcpip-forward") == 0) {
970 char *listen_address;
973 pw = auth_get_user();
975 fatal("server_input_global_request: no user");
976 listen_address = packet_get_string(NULL); /* XXX currently ignored */
977 listen_port = (u_short)packet_get_int();
978 debug("server_input_global_request: tcpip-forward listen %s port %d",
979 listen_address, listen_port);
981 /* check permissions */
982 if (!options.allow_tcp_forwarding ||
983 no_port_forwarding_flag
984 #ifndef NO_IPPORT_RESERVED_CONCEPT
985 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
989 packet_send_debug("Server has disabled port forwarding.");
991 /* Start listening on the port */
992 success = channel_setup_remote_fwd_listener(
993 listen_address, listen_port, options.gateway_ports);
995 xfree(listen_address);
998 packet_start(success ?
999 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1001 packet_write_wait();
1006 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1009 int id, reply, success = 0;
1012 id = packet_get_int();
1013 rtype = packet_get_string(NULL);
1014 reply = packet_get_char();
1016 debug("server_input_channel_req: channel %d request %s reply %d",
1019 if ((c = channel_lookup(id)) == NULL)
1020 packet_disconnect("server_input_channel_req: "
1021 "unknown channel %d", id);
1022 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1023 success = session_input_channel_req(c, rtype);
1025 packet_start(success ?
1026 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1027 packet_put_int(c->remote_id);
1034 server_init_dispatch_20(void)
1036 debug("server_init_dispatch_20");
1037 dispatch_init(&dispatch_protocol_error);
1038 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1039 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1040 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1041 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1042 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1043 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1044 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1045 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1046 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1047 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1049 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure);
1051 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1054 server_init_dispatch_13(void)
1056 debug("server_init_dispatch_13");
1057 dispatch_init(NULL);
1058 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1059 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1060 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1061 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1062 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1063 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1064 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1065 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1066 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1069 server_init_dispatch_15(void)
1071 server_init_dispatch_13();
1072 debug("server_init_dispatch_15");
1073 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1074 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1077 server_init_dispatch(void)
1080 server_init_dispatch_20();
1082 server_init_dispatch_13();
1084 server_init_dispatch_15();