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 1.103 2002/06/24 14:33:27 markus Exp $");
53 #include "auth-options.h"
54 #include "serverloop.h"
58 extern ServerOptions options;
62 static Authctxt *xxx_authctxt;
64 static Buffer stdin_buffer; /* Buffer for stdin data. */
65 static Buffer stdout_buffer; /* Buffer for stdout data. */
66 static Buffer stderr_buffer; /* Buffer for stderr data. */
67 static int fdin; /* Descriptor for stdin (for writing) */
68 static int fdout; /* Descriptor for stdout (for reading);
69 May be same number as fdin. */
70 static int fderr; /* Descriptor for stderr. May be -1. */
71 static long stdin_bytes = 0; /* Number of bytes written to stdin. */
72 static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
73 static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
74 static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
75 static int stdin_eof = 0; /* EOF message received from client. */
76 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
77 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
78 static int fdin_is_tty = 0; /* fdin points to a tty. */
79 static int connection_in; /* Connection to client (input). */
80 static int connection_out; /* Connection to client (output). */
81 static int connection_closed = 0; /* Connection to client closed. */
82 static u_int buffer_high; /* "Soft" max buffer size. */
83 static int client_alive_timeouts = 0;
86 * This SIGCHLD kludge is used to detect when the child exits. The server
87 * will exit after that, as soon as forwarded connections have terminated.
90 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
93 static void server_init_dispatch(void);
96 * we write to this pipe if a SIGCHLD is caught in order to avoid
97 * the race between select() and child_terminated
99 static int notify_pipe[2];
103 if (pipe(notify_pipe) < 0) {
104 error("pipe(notify_pipe) failed %s", strerror(errno));
105 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
106 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
107 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
108 close(notify_pipe[0]);
109 close(notify_pipe[1]);
111 set_nonblock(notify_pipe[0]);
112 set_nonblock(notify_pipe[1]);
115 notify_pipe[0] = -1; /* read end */
116 notify_pipe[1] = -1; /* write end */
121 if (notify_pipe[1] != -1)
122 write(notify_pipe[1], "", 1);
125 notify_prepare(fd_set *readset)
127 if (notify_pipe[0] != -1)
128 FD_SET(notify_pipe[0], readset);
131 notify_done(fd_set *readset)
135 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
136 while (read(notify_pipe[0], &c, 1) != -1)
137 debug2("notify_done: reading");
141 sigchld_handler(int sig)
143 int save_errno = errno;
144 debug("Received SIGCHLD.");
145 child_terminated = 1;
146 mysignal(SIGCHLD, sigchld_handler);
152 * Make packets from buffered stderr data, and buffer it for sending
156 make_packets_from_stderr_data(void)
160 /* Send buffered stderr data to the client. */
161 while (buffer_len(&stderr_buffer) > 0 &&
162 packet_not_very_much_data_to_write()) {
163 len = buffer_len(&stderr_buffer);
164 if (packet_is_interactive()) {
168 /* Keep the packets at reasonable size. */
169 if (len > packet_get_maxsize())
170 len = packet_get_maxsize();
172 packet_start(SSH_SMSG_STDERR_DATA);
173 packet_put_string(buffer_ptr(&stderr_buffer), len);
175 buffer_consume(&stderr_buffer, len);
181 * Make packets from buffered stdout data, and buffer it for sending to the
185 make_packets_from_stdout_data(void)
189 /* Send buffered stdout data to the client. */
190 while (buffer_len(&stdout_buffer) > 0 &&
191 packet_not_very_much_data_to_write()) {
192 len = buffer_len(&stdout_buffer);
193 if (packet_is_interactive()) {
197 /* Keep the packets at reasonable size. */
198 if (len > packet_get_maxsize())
199 len = packet_get_maxsize();
201 packet_start(SSH_SMSG_STDOUT_DATA);
202 packet_put_string(buffer_ptr(&stdout_buffer), len);
204 buffer_consume(&stdout_buffer, len);
210 client_alive_check(void)
212 static int had_channel = 0;
215 id = channel_find_open();
219 packet_disconnect("No open channels after timeout!");
223 /* timeout, check to see how many we have had */
224 if (++client_alive_timeouts > options.client_alive_count_max)
225 packet_disconnect("Timeout, your session not responding.");
228 * send a bogus channel request with "wantreply",
229 * we should get back a failure
231 channel_request_start(id, "keepalive@openssh.com", 1);
236 * Sleep in select() until we can do something. This will initialize the
237 * select masks. Upon return, the masks will indicate which descriptors
238 * have data or can accept data. Optionally, a maximum time can be specified
239 * for the duration of the wait (0 = infinite).
242 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
243 int *nallocp, u_int max_time_milliseconds)
245 struct timeval tv, *tvp;
247 int client_alive_scheduled = 0;
250 * if using client_alive, set the max timeout accordingly,
251 * and indicate that this particular timeout was for client
252 * alive by setting the client_alive_scheduled flag.
254 * this could be randomized somewhat to make traffic
255 * analysis more difficult, but we're not doing it yet.
258 max_time_milliseconds == 0 && options.client_alive_interval) {
259 client_alive_scheduled = 1;
260 max_time_milliseconds = options.client_alive_interval * 1000;
263 /* Allocate and update select() masks for channel descriptors. */
264 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
268 /* wrong: bad condition XXX */
269 if (channel_not_very_much_buffered_data())
271 FD_SET(connection_in, *readsetp);
274 * Read packets from the client unless we have too much
275 * buffered stdin or channel data.
277 if (buffer_len(&stdin_buffer) < buffer_high &&
278 channel_not_very_much_buffered_data())
279 FD_SET(connection_in, *readsetp);
281 * If there is not too much data already buffered going to
282 * the client, try to get some more data from the program.
284 if (packet_not_very_much_data_to_write()) {
286 FD_SET(fdout, *readsetp);
288 FD_SET(fderr, *readsetp);
291 * If we have buffered data, try to write some of that data
294 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
295 FD_SET(fdin, *writesetp);
297 notify_prepare(*readsetp);
300 * If we have buffered packet data going to the client, mark that
303 if (packet_have_data_to_write())
304 FD_SET(connection_out, *writesetp);
307 * If child has terminated and there is enough buffer space to read
308 * from it, then read as much as is available and exit.
310 if (child_terminated && packet_not_very_much_data_to_write())
311 if (max_time_milliseconds == 0 || client_alive_scheduled)
312 max_time_milliseconds = 100;
314 if (max_time_milliseconds == 0)
317 tv.tv_sec = max_time_milliseconds / 1000;
318 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
322 /* Wait for something to happen, or the timeout to expire. */
323 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
326 memset(*readsetp, 0, *nallocp);
327 memset(*writesetp, 0, *nallocp);
329 error("select: %.100s", strerror(errno));
330 } else if (ret == 0 && client_alive_scheduled)
331 client_alive_check();
333 notify_done(*readsetp);
337 * Processes input from the client and the program. Input data is stored
338 * in buffers and processed later.
341 process_input(fd_set * readset)
346 /* Read and buffer any input data from the client. */
347 if (FD_ISSET(connection_in, readset)) {
348 len = read(connection_in, buf, sizeof(buf));
350 verbose("Connection closed by remote host.");
351 connection_closed = 1;
355 } else if (len < 0) {
356 if (errno != EINTR && errno != EAGAIN) {
357 verbose("Read error from remote host: %.100s", strerror(errno));
361 /* Buffer any received data. */
362 packet_process_incoming(buf, len);
368 /* Read and buffer any available stdout data from the program. */
369 if (!fdout_eof && FD_ISSET(fdout, readset)) {
370 len = read(fdout, buf, sizeof(buf));
371 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
373 } else if (len <= 0) {
376 buffer_append(&stdout_buffer, buf, len);
380 /* Read and buffer any available stderr data from the program. */
381 if (!fderr_eof && FD_ISSET(fderr, readset)) {
382 len = read(fderr, buf, sizeof(buf));
383 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
385 } else if (len <= 0) {
388 buffer_append(&stderr_buffer, buf, len);
394 * Sends data from internal buffers to client program stdin.
397 process_output(fd_set * writeset)
404 /* Write buffered data to program stdin. */
405 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
406 data = buffer_ptr(&stdin_buffer);
407 dlen = buffer_len(&stdin_buffer);
408 len = write(fdin, data, dlen);
409 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
411 } else if (len <= 0) {
415 shutdown(fdin, SHUT_WR); /* We will no longer send. */
418 /* Successful write. */
419 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
420 tcgetattr(fdin, &tio) == 0 &&
421 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
423 * Simulate echo to reduce the impact of
426 packet_send_ignore(len);
429 /* Consume the data from the buffer. */
430 buffer_consume(&stdin_buffer, len);
431 /* Update the count of bytes written to the program. */
435 /* Send any buffered packet data to the client. */
436 if (FD_ISSET(connection_out, writeset))
441 * Wait until all buffered output has been sent to the client.
442 * This is used when the program terminates.
447 /* Send any buffered stdout data to the client. */
448 if (buffer_len(&stdout_buffer) > 0) {
449 packet_start(SSH_SMSG_STDOUT_DATA);
450 packet_put_string(buffer_ptr(&stdout_buffer),
451 buffer_len(&stdout_buffer));
453 /* Update the count of sent bytes. */
454 stdout_bytes += buffer_len(&stdout_buffer);
456 /* Send any buffered stderr data to the client. */
457 if (buffer_len(&stderr_buffer) > 0) {
458 packet_start(SSH_SMSG_STDERR_DATA);
459 packet_put_string(buffer_ptr(&stderr_buffer),
460 buffer_len(&stderr_buffer));
462 /* Update the count of sent bytes. */
463 stderr_bytes += buffer_len(&stderr_buffer);
465 /* Wait until all buffered data has been written to the client. */
470 process_buffered_input_packets(void)
472 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
476 * Performs the interactive session. This handles data transmission between
477 * the client and the program. Note that the notion of stdin, stdout, and
478 * stderr in this function is sort of reversed: this function writes to
479 * stdin (of the child program), and reads from stdout and stderr (of the
483 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
485 fd_set *readset = NULL, *writeset = NULL;
486 int max_fd = 0, nalloc = 0;
487 int wait_status; /* Status returned by wait(). */
488 pid_t wait_pid; /* pid returned by wait(). */
489 int waiting_termination = 0; /* Have displayed waiting close message. */
490 u_int max_time_milliseconds;
491 u_int previous_stdout_buffer_bytes;
492 u_int stdout_buffer_bytes;
495 debug("Entering interactive session.");
497 /* Initialize the SIGCHLD kludge. */
498 child_terminated = 0;
499 mysignal(SIGCHLD, sigchld_handler);
501 /* Initialize our global variables. */
509 /* we don't have stderr for interactive terminal sessions, see below */
513 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
516 connection_in = packet_get_connection_in();
517 connection_out = packet_get_connection_out();
521 previous_stdout_buffer_bytes = 0;
523 /* Set approximate I/O buffer size. */
524 if (packet_is_interactive())
527 buffer_high = 64 * 1024;
530 /* Initialize max_fd to the maximum of the known file descriptors. */
531 max_fd = MAX(connection_in, connection_out);
532 max_fd = MAX(max_fd, fdin);
533 max_fd = MAX(max_fd, fdout);
535 max_fd = MAX(max_fd, fderr);
538 /* Initialize Initialize buffers. */
539 buffer_init(&stdin_buffer);
540 buffer_init(&stdout_buffer);
541 buffer_init(&stderr_buffer);
544 * If we have no separate fderr (which is the case when we have a pty
545 * - there we cannot make difference between data sent to stdout and
546 * stderr), indicate that we have seen an EOF from stderr. This way
547 * we don\'t need to check the descriptor everywhere.
552 server_init_dispatch();
554 /* Main loop of the server for the interactive session mode. */
557 /* Process buffered packets from the client. */
558 process_buffered_input_packets();
561 * If we have received eof, and there is no more pending
562 * input data, cause a real eof by closing fdin.
564 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
568 shutdown(fdin, SHUT_WR); /* We will no longer send. */
571 /* Make packets from buffered stderr data to send to the client. */
572 make_packets_from_stderr_data();
575 * Make packets from buffered stdout data to send to the
576 * client. If there is very little to send, this arranges to
577 * not send them now, but to wait a short while to see if we
578 * are getting more data. This is necessary, as some systems
579 * wake up readers from a pty after each separate character.
581 max_time_milliseconds = 0;
582 stdout_buffer_bytes = buffer_len(&stdout_buffer);
583 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
584 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
585 /* try again after a while */
586 max_time_milliseconds = 10;
589 make_packets_from_stdout_data();
591 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
593 /* Send channel data to the client. */
594 if (packet_not_very_much_data_to_write())
595 channel_output_poll();
598 * Bail out of the loop if the program has closed its output
599 * descriptors, and we have no more data to send to the
600 * client, and there is no pending buffered data.
602 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
603 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
604 if (!channel_still_open())
606 if (!waiting_termination) {
607 const char *s = "Waiting for forwarded connections to terminate...\r\n";
609 waiting_termination = 1;
610 buffer_append(&stderr_buffer, s, strlen(s));
612 /* Display list of open channels. */
613 cp = channel_open_message();
614 buffer_append(&stderr_buffer, cp, strlen(cp));
618 max_fd = MAX(connection_in, connection_out);
619 max_fd = MAX(max_fd, fdin);
620 max_fd = MAX(max_fd, fdout);
621 max_fd = MAX(max_fd, fderr);
622 max_fd = MAX(max_fd, notify_pipe[0]);
624 /* Sleep in select() until we can do something. */
625 wait_until_can_do_something(&readset, &writeset, &max_fd,
626 &nalloc, max_time_milliseconds);
628 /* Process any channel events. */
629 channel_after_select(readset, writeset);
631 /* Process input from the client and from program stdout/stderr. */
632 process_input(readset);
634 /* Process output to the client and to program stdin. */
635 process_output(writeset);
642 /* Cleanup and termination code. */
644 /* Wait until all output has been sent to the client. */
647 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
648 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
650 /* Free and clear the buffers. */
651 buffer_free(&stdin_buffer);
652 buffer_free(&stdout_buffer);
653 buffer_free(&stderr_buffer);
655 /* Close the file descriptors. */
670 /* We no longer want our SIGCHLD handler to be called. */
671 mysignal(SIGCHLD, SIG_DFL);
673 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
675 packet_disconnect("wait: %.100s", strerror(errno));
677 error("Strange, wait returned pid %ld, expected %ld",
678 (long)wait_pid, (long)pid);
680 /* Check if it exited normally. */
681 if (WIFEXITED(wait_status)) {
682 /* Yes, normal exit. Get exit status and send it to the client. */
683 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
684 packet_start(SSH_SMSG_EXITSTATUS);
685 packet_put_int(WEXITSTATUS(wait_status));
690 * Wait for exit confirmation. Note that there might be
691 * other packets coming before it; however, the program has
692 * already died so we just ignore them. The client is
693 * supposed to respond with the confirmation when it receives
697 type = packet_read();
699 while (type != SSH_CMSG_EXIT_CONFIRMATION);
701 debug("Received exit confirmation.");
704 /* Check if the program terminated due to a signal. */
705 if (WIFSIGNALED(wait_status))
706 packet_disconnect("Command terminated on signal %d.",
707 WTERMSIG(wait_status));
709 /* Some weird exit cause. Just exit. */
710 packet_disconnect("wait returned status %04x.", wait_status);
715 collect_children(void)
721 /* block SIGCHLD while we check for dead children */
723 sigaddset(&nset, SIGCHLD);
724 sigprocmask(SIG_BLOCK, &nset, &oset);
725 if (child_terminated) {
726 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
727 (pid < 0 && errno == EINTR))
729 session_close_by_pid(pid, status);
730 child_terminated = 0;
732 sigprocmask(SIG_SETMASK, &oset, NULL);
736 server_loop2(Authctxt *authctxt)
738 fd_set *readset = NULL, *writeset = NULL;
739 int rekeying = 0, max_fd, nalloc = 0;
741 debug("Entering interactive session for SSH2.");
743 mysignal(SIGCHLD, sigchld_handler);
744 child_terminated = 0;
745 connection_in = packet_get_connection_in();
746 connection_out = packet_get_connection_out();
750 max_fd = MAX(connection_in, connection_out);
751 max_fd = MAX(max_fd, notify_pipe[0]);
753 xxx_authctxt = authctxt;
755 server_init_dispatch();
758 process_buffered_input_packets();
760 rekeying = (xxx_kex != NULL && !xxx_kex->done);
762 if (!rekeying && packet_not_very_much_data_to_write())
763 channel_output_poll();
764 wait_until_can_do_something(&readset, &writeset, &max_fd,
769 channel_after_select(readset, writeset);
770 process_input(readset);
771 if (connection_closed)
773 process_output(writeset);
782 /* free all channels, no more reads and writes */
785 /* free remaining sessions, e.g. remove wtmp entries */
786 session_destroy_all(NULL);
790 server_input_channel_failure(int type, u_int32_t seq, void *ctxt)
792 debug("Got CHANNEL_FAILURE for keepalive");
794 * reset timeout, since we got a sane answer from the client.
795 * even if this was generated by something other than
796 * the bogus CHANNEL_REQUEST we send for keepalives.
798 client_alive_timeouts = 0;
803 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
808 /* Stdin data from the client. Append it to the buffer. */
809 /* Ignore any data if the client has closed stdin. */
812 data = packet_get_string(&data_len);
814 buffer_append(&stdin_buffer, data, data_len);
815 memset(data, 0, data_len);
820 server_input_eof(int type, u_int32_t seq, void *ctxt)
823 * Eof from the client. The stdin descriptor to the
824 * program will be closed when all buffered data has
827 debug("EOF received for stdin.");
833 server_input_window_size(int type, u_int32_t seq, void *ctxt)
835 int row = packet_get_int();
836 int col = packet_get_int();
837 int xpixel = packet_get_int();
838 int ypixel = packet_get_int();
840 debug("Window change received.");
843 pty_change_window_size(fdin, row, col, xpixel, ypixel);
847 server_request_direct_tcpip(char *ctype)
851 char *target, *originator;
852 int target_port, originator_port;
854 target = packet_get_string(NULL);
855 target_port = packet_get_int();
856 originator = packet_get_string(NULL);
857 originator_port = packet_get_int();
860 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
861 originator, originator_port, target, target_port);
863 /* XXX check permission */
864 sock = channel_connect_to(target, target_port);
869 c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
870 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
871 CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1);
876 server_request_session(char *ctype)
880 debug("input_session_request");
883 * A server session has no fd to read or write until a
884 * CHANNEL_REQUEST for a shell is made, so we set the type to
885 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
886 * CHANNEL_REQUEST messages is registered.
888 c = channel_new(ctype, SSH_CHANNEL_LARVAL,
889 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
890 0, xstrdup("server-session"), 1);
891 if (session_open(xxx_authctxt, c->self) != 1) {
892 debug("session open failed, free channel %d", c->self);
896 channel_register_cleanup(c->self, session_close_by_channel);
901 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
906 u_int rmaxpack, rwindow, len;
908 ctype = packet_get_string(&len);
909 rchan = packet_get_int();
910 rwindow = packet_get_int();
911 rmaxpack = packet_get_int();
913 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
914 ctype, rchan, rwindow, rmaxpack);
916 if (strcmp(ctype, "session") == 0) {
917 c = server_request_session(ctype);
918 } else if (strcmp(ctype, "direct-tcpip") == 0) {
919 c = server_request_direct_tcpip(ctype);
922 debug("server_input_channel_open: confirm %s", ctype);
923 c->remote_id = rchan;
924 c->remote_window = rwindow;
925 c->remote_maxpacket = rmaxpack;
926 if (c->type != SSH_CHANNEL_CONNECTING) {
927 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
928 packet_put_int(c->remote_id);
929 packet_put_int(c->self);
930 packet_put_int(c->local_window);
931 packet_put_int(c->local_maxpacket);
935 debug("server_input_channel_open: failure %s", ctype);
936 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
937 packet_put_int(rchan);
938 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
939 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
940 packet_put_cstring("open failed");
941 packet_put_cstring("");
949 server_input_global_request(int type, u_int32_t seq, void *ctxt)
955 rtype = packet_get_string(NULL);
956 want_reply = packet_get_char();
957 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
959 /* -R style forwarding */
960 if (strcmp(rtype, "tcpip-forward") == 0) {
962 char *listen_address;
965 pw = auth_get_user();
967 fatal("server_input_global_request: no user");
968 listen_address = packet_get_string(NULL); /* XXX currently ignored */
969 listen_port = (u_short)packet_get_int();
970 debug("server_input_global_request: tcpip-forward listen %s port %d",
971 listen_address, listen_port);
973 /* check permissions */
974 if (!options.allow_tcp_forwarding ||
975 no_port_forwarding_flag
976 #ifndef NO_IPPORT_RESERVED_CONCEPT
977 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
981 packet_send_debug("Server has disabled port forwarding.");
983 /* Start listening on the port */
984 success = channel_setup_remote_fwd_listener(
985 listen_address, listen_port, options.gateway_ports);
987 xfree(listen_address);
990 packet_start(success ?
991 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
998 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1001 int id, reply, success = 0;
1004 id = packet_get_int();
1005 rtype = packet_get_string(NULL);
1006 reply = packet_get_char();
1008 debug("server_input_channel_req: channel %d request %s reply %d",
1011 if ((c = channel_lookup(id)) == NULL)
1012 packet_disconnect("server_input_channel_req: "
1013 "unknown channel %d", id);
1014 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1015 success = session_input_channel_req(c, rtype);
1017 packet_start(success ?
1018 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1019 packet_put_int(c->remote_id);
1026 server_init_dispatch_20(void)
1028 debug("server_init_dispatch_20");
1029 dispatch_init(&dispatch_protocol_error);
1030 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1031 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1032 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1033 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1034 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1035 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1036 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1037 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1038 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1039 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1041 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure);
1043 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1046 server_init_dispatch_13(void)
1048 debug("server_init_dispatch_13");
1049 dispatch_init(NULL);
1050 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1051 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1052 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1053 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1054 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1055 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1056 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1057 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1058 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1061 server_init_dispatch_15(void)
1063 server_init_dispatch_13();
1064 debug("server_init_dispatch_15");
1065 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1066 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1069 server_init_dispatch(void)
1072 server_init_dispatch_20();
1074 server_init_dispatch_13();
1076 server_init_dispatch_15();