blob: 3d8e7cfb5a5c81e5d226bdb6fd95b0c7ea99bec8 [file] [log] [blame]
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * Server main loop for handling the interactive session.
Damien Millere4340be2000-09-16 13:29:08 +11006 *
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".
12 *
Damien Millerefb4afe2000-04-12 18:45:05 +100013 * SSH2 support by Markus Friedl.
Ben Lindstrom44697232001-07-04 03:32:30 +000014 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110015 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
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.
24 *
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.
Damien Millerefb4afe2000-04-12 18:45:05 +100035 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100036
37#include "includes.h"
Darren Tucker0d0e8f02005-12-20 16:08:42 +110038RCSID("$OpenBSD: serverloop.c,v 1.124 2005/12/13 15:03:02 reyk Exp $");
Damien Miller69b69aa2000-10-28 14:19:58 +110039
Damien Millerd4a8b7e1999-10-27 13:42:43 +100040#include "xmalloc.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100041#include "packet.h"
42#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000043#include "log.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100044#include "servconf.h"
Damien Miller16aed052002-09-22 01:26:27 +100045#include "canohost.h"
Ben Lindstromd95c09c2001-02-18 19:13:33 +000046#include "sshpty.h"
Ben Lindstromc7637672001-06-09 00:36:26 +000047#include "channels.h"
Damien Millerb38eff82000-04-01 11:09:21 +100048#include "compat.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000049#include "ssh1.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100050#include "ssh2.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000051#include "auth.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100052#include "session.h"
Damien Millerb38eff82000-04-01 11:09:21 +100053#include "dispatch.h"
Damien Millerf6d9e222000-06-18 14:50:44 +100054#include "auth-options.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000055#include "serverloop.h"
56#include "misc.h"
Ben Lindstrom8ac91062001-04-04 17:57:54 +000057#include "kex.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100058
Damien Miller50a41ed2000-10-16 12:14:42 +110059extern ServerOptions options;
60
Ben Lindstrom8ac91062001-04-04 17:57:54 +000061/* XXX */
62extern Kex *xxx_kex;
Darren Tucker3e33cec2003-10-02 16:12:36 +100063extern Authctxt *the_authctxt;
Damien Miller24ecf612005-11-05 15:16:52 +110064extern int use_privsep;
Ben Lindstrom8ac91062001-04-04 17:57:54 +000065
Damien Millerd4a8b7e1999-10-27 13:42:43 +100066static Buffer stdin_buffer; /* Buffer for stdin data. */
67static Buffer stdout_buffer; /* Buffer for stdout data. */
68static Buffer stderr_buffer; /* Buffer for stderr data. */
69static int fdin; /* Descriptor for stdin (for writing) */
70static int fdout; /* Descriptor for stdout (for reading);
71 May be same number as fdin. */
72static int fderr; /* Descriptor for stderr. May be -1. */
73static long stdin_bytes = 0; /* Number of bytes written to stdin. */
74static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
75static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
76static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
77static int stdin_eof = 0; /* EOF message received from client. */
78static int fdout_eof = 0; /* EOF encountered reading from fdout. */
79static int fderr_eof = 0; /* EOF encountered readung from fderr. */
Damien Miller225736c2001-02-19 21:51:08 +110080static int fdin_is_tty = 0; /* fdin points to a tty. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100081static int connection_in; /* Connection to client (input). */
82static int connection_out; /* Connection to client (output). */
Ben Lindstrome34ab4c2001-04-07 01:12:11 +000083static int connection_closed = 0; /* Connection to client closed. */
84static u_int buffer_high; /* "Soft" max buffer size. */
Damien Miller8c3902a2001-10-10 15:01:40 +100085static int client_alive_timeouts = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100086
Damien Miller5428f641999-11-25 11:54:57 +110087/*
88 * This SIGCHLD kludge is used to detect when the child exits. The server
89 * will exit after that, as soon as forwarded connections have terminated.
90 */
Ben Lindstrombba81212001-06-25 05:01:22 +000091
Ben Lindstrom5e71c542001-12-06 16:48:14 +000092static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100093
Damien Miller24ecf612005-11-05 15:16:52 +110094/* Cleanup on signals (!use_privsep case only) */
95static volatile sig_atomic_t received_sigterm = 0;
96
Ben Lindstrombba81212001-06-25 05:01:22 +000097/* prototypes */
98static void server_init_dispatch(void);
Damien Millerb38eff82000-04-01 11:09:21 +100099
Damien Millerf6681a32001-12-21 14:53:11 +1100100/*
101 * we write to this pipe if a SIGCHLD is caught in order to avoid
102 * the race between select() and child_terminated
103 */
104static int notify_pipe[2];
105static void
106notify_setup(void)
107{
108 if (pipe(notify_pipe) < 0) {
109 error("pipe(notify_pipe) failed %s", strerror(errno));
110 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
111 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
112 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
113 close(notify_pipe[0]);
114 close(notify_pipe[1]);
115 } else {
116 set_nonblock(notify_pipe[0]);
117 set_nonblock(notify_pipe[1]);
118 return;
119 }
120 notify_pipe[0] = -1; /* read end */
121 notify_pipe[1] = -1; /* write end */
122}
123static void
124notify_parent(void)
125{
126 if (notify_pipe[1] != -1)
127 write(notify_pipe[1], "", 1);
128}
129static void
130notify_prepare(fd_set *readset)
131{
132 if (notify_pipe[0] != -1)
133 FD_SET(notify_pipe[0], readset);
134}
135static void
136notify_done(fd_set *readset)
137{
138 char c;
139
140 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
141 while (read(notify_pipe[0], &c, 1) != -1)
142 debug2("notify_done: reading");
143}
144
Ben Lindstrombba81212001-06-25 05:01:22 +0000145static void
Damien Miller95def091999-11-25 00:26:21 +1100146sigchld_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000147{
Damien Miller95def091999-11-25 00:26:21 +1100148 int save_errno = errno;
Damien Millerefb4afe2000-04-12 18:45:05 +1000149 debug("Received SIGCHLD.");
150 child_terminated = 1;
Tim Rice81ed5182002-09-25 17:38:46 -0700151#ifndef _UNICOS
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000152 mysignal(SIGCHLD, sigchld_handler);
Tim Rice81ed5182002-09-25 17:38:46 -0700153#endif
Damien Millerf6681a32001-12-21 14:53:11 +1100154 notify_parent();
Damien Millerefb4afe2000-04-12 18:45:05 +1000155 errno = save_errno;
156}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000157
Damien Miller24ecf612005-11-05 15:16:52 +1100158static void
159sigterm_handler(int sig)
160{
161 received_sigterm = sig;
162}
163
Damien Miller95def091999-11-25 00:26:21 +1100164/*
Damien Miller95def091999-11-25 00:26:21 +1100165 * Make packets from buffered stderr data, and buffer it for sending
166 * to the client.
167 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000168static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000169make_packets_from_stderr_data(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000170{
Darren Tucker502d3842003-06-28 12:38:01 +1000171 u_int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000172
Damien Miller95def091999-11-25 00:26:21 +1100173 /* Send buffered stderr data to the client. */
174 while (buffer_len(&stderr_buffer) > 0 &&
Damien Miller037a0dc1999-12-07 15:38:31 +1100175 packet_not_very_much_data_to_write()) {
Damien Miller95def091999-11-25 00:26:21 +1100176 len = buffer_len(&stderr_buffer);
177 if (packet_is_interactive()) {
178 if (len > 512)
179 len = 512;
180 } else {
181 /* Keep the packets at reasonable size. */
182 if (len > packet_get_maxsize())
183 len = packet_get_maxsize();
184 }
185 packet_start(SSH_SMSG_STDERR_DATA);
186 packet_put_string(buffer_ptr(&stderr_buffer), len);
187 packet_send();
188 buffer_consume(&stderr_buffer, len);
189 stderr_bytes += len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000190 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000191}
192
Damien Miller95def091999-11-25 00:26:21 +1100193/*
194 * Make packets from buffered stdout data, and buffer it for sending to the
195 * client.
196 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000197static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000198make_packets_from_stdout_data(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000199{
Darren Tucker502d3842003-06-28 12:38:01 +1000200 u_int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000201
Damien Miller95def091999-11-25 00:26:21 +1100202 /* Send buffered stdout data to the client. */
203 while (buffer_len(&stdout_buffer) > 0 &&
Damien Miller037a0dc1999-12-07 15:38:31 +1100204 packet_not_very_much_data_to_write()) {
Damien Miller95def091999-11-25 00:26:21 +1100205 len = buffer_len(&stdout_buffer);
206 if (packet_is_interactive()) {
207 if (len > 512)
208 len = 512;
209 } else {
210 /* Keep the packets at reasonable size. */
211 if (len > packet_get_maxsize())
Kevin Stevesef4eea92001-02-05 12:42:17 +0000212 len = packet_get_maxsize();
Damien Miller95def091999-11-25 00:26:21 +1100213 }
214 packet_start(SSH_SMSG_STDOUT_DATA);
215 packet_put_string(buffer_ptr(&stdout_buffer), len);
216 packet_send();
217 buffer_consume(&stdout_buffer, len);
218 stdout_bytes += len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000219 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000220}
221
Damien Miller8c3902a2001-10-10 15:01:40 +1000222static void
223client_alive_check(void)
224{
Damien Millerb5820f42003-12-17 16:27:32 +1100225 int channel_id;
Damien Miller056cf732002-01-22 23:21:39 +1100226
Damien Miller8c3902a2001-10-10 15:01:40 +1000227 /* timeout, check to see how many we have had */
228 if (++client_alive_timeouts > options.client_alive_count_max)
229 packet_disconnect("Timeout, your session not responding.");
230
Damien Miller8c3902a2001-10-10 15:01:40 +1000231 /*
Damien Millerb5820f42003-12-17 16:27:32 +1100232 * send a bogus global/channel request with "wantreply",
Damien Miller8c3902a2001-10-10 15:01:40 +1000233 * we should get back a failure
234 */
Damien Millerb5820f42003-12-17 16:27:32 +1100235 if ((channel_id = channel_find_open()) == -1) {
236 packet_start(SSH2_MSG_GLOBAL_REQUEST);
237 packet_put_cstring("keepalive@openssh.com");
238 packet_put_char(1); /* boolean: want reply */
239 } else {
240 channel_request_start(channel_id, "keepalive@openssh.com", 1);
241 }
Damien Miller8c3902a2001-10-10 15:01:40 +1000242 packet_send();
243}
244
Damien Miller95def091999-11-25 00:26:21 +1100245/*
246 * Sleep in select() until we can do something. This will initialize the
247 * select masks. Upon return, the masks will indicate which descriptors
248 * have data or can accept data. Optionally, a maximum time can be specified
249 * for the duration of the wait (0 = infinite).
250 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000251static void
Damien Miller5e953212001-01-30 09:14:00 +1100252wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
Darren Tuckerc7a6fc42004-08-13 21:18:00 +1000253 u_int *nallocp, u_int max_time_milliseconds)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000254{
Damien Miller95def091999-11-25 00:26:21 +1100255 struct timeval tv, *tvp;
256 int ret;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000257 int client_alive_scheduled = 0;
258
259 /*
Damien Miller9f0f5c62001-12-21 14:45:46 +1100260 * if using client_alive, set the max timeout accordingly,
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000261 * and indicate that this particular timeout was for client
262 * alive by setting the client_alive_scheduled flag.
263 *
264 * this could be randomized somewhat to make traffic
Damien Miller9f0f5c62001-12-21 14:45:46 +1100265 * analysis more difficult, but we're not doing it yet.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000266 */
Ben Lindstrom36857f62001-07-18 15:48:57 +0000267 if (compat20 &&
268 max_time_milliseconds == 0 && options.client_alive_interval) {
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000269 client_alive_scheduled = 1;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000270 max_time_milliseconds = options.client_alive_interval * 1000;
Ben Lindstrom36857f62001-07-18 15:48:57 +0000271 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000272
Damien Miller5e953212001-01-30 09:14:00 +1100273 /* Allocate and update select() masks for channel descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000274 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000275
Damien Millerefb4afe2000-04-12 18:45:05 +1000276 if (compat20) {
Damien Milleraf5f2e62001-10-10 15:01:16 +1000277#if 0
Damien Millere247cc42000-05-07 12:03:14 +1000278 /* wrong: bad condition XXX */
Damien Millerefb4afe2000-04-12 18:45:05 +1000279 if (channel_not_very_much_buffered_data())
Damien Milleraf5f2e62001-10-10 15:01:16 +1000280#endif
281 FD_SET(connection_in, *readsetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000282 } else {
Damien Millerb1715dc2000-05-30 13:44:51 +1000283 /*
284 * Read packets from the client unless we have too much
285 * buffered stdin or channel data.
286 */
287 if (buffer_len(&stdin_buffer) < buffer_high &&
Damien Millerefb4afe2000-04-12 18:45:05 +1000288 channel_not_very_much_buffered_data())
Damien Miller5e953212001-01-30 09:14:00 +1100289 FD_SET(connection_in, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000290 /*
291 * If there is not too much data already buffered going to
292 * the client, try to get some more data from the program.
293 */
294 if (packet_not_very_much_data_to_write()) {
295 if (!fdout_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100296 FD_SET(fdout, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000297 if (!fderr_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100298 FD_SET(fderr, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000299 }
300 /*
301 * If we have buffered data, try to write some of that data
302 * to the program.
303 */
304 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
Damien Miller5e953212001-01-30 09:14:00 +1100305 FD_SET(fdin, *writesetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000306 }
Damien Millerf6681a32001-12-21 14:53:11 +1100307 notify_prepare(*readsetp);
Damien Miller95def091999-11-25 00:26:21 +1100308
Damien Miller5428f641999-11-25 11:54:57 +1100309 /*
310 * If we have buffered packet data going to the client, mark that
311 * descriptor.
312 */
Damien Miller95def091999-11-25 00:26:21 +1100313 if (packet_have_data_to_write())
Damien Miller5e953212001-01-30 09:14:00 +1100314 FD_SET(connection_out, *writesetp);
Damien Miller95def091999-11-25 00:26:21 +1100315
Damien Miller5428f641999-11-25 11:54:57 +1100316 /*
317 * If child has terminated and there is enough buffer space to read
318 * from it, then read as much as is available and exit.
319 */
Damien Miller95def091999-11-25 00:26:21 +1100320 if (child_terminated && packet_not_very_much_data_to_write())
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000321 if (max_time_milliseconds == 0 || client_alive_scheduled)
Damien Miller95def091999-11-25 00:26:21 +1100322 max_time_milliseconds = 100;
323
324 if (max_time_milliseconds == 0)
325 tvp = NULL;
326 else {
327 tv.tv_sec = max_time_milliseconds / 1000;
328 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
329 tvp = &tv;
330 }
331
332 /* Wait for something to happen, or the timeout to expire. */
Damien Miller5e953212001-01-30 09:14:00 +1100333 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
Damien Miller95def091999-11-25 00:26:21 +1100334
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000335 if (ret == -1) {
Damien Miller79faeff2001-11-12 11:06:32 +1100336 memset(*readsetp, 0, *nallocp);
337 memset(*writesetp, 0, *nallocp);
Damien Miller95def091999-11-25 00:26:21 +1100338 if (errno != EINTR)
339 error("select: %.100s", strerror(errno));
Damien Miller3ec27592001-10-12 11:35:04 +1000340 } else if (ret == 0 && client_alive_scheduled)
Damien Miller8c3902a2001-10-10 15:01:40 +1000341 client_alive_check();
Damien Millerf6681a32001-12-21 14:53:11 +1100342
343 notify_done(*readsetp);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000344}
345
Damien Miller95def091999-11-25 00:26:21 +1100346/*
347 * Processes input from the client and the program. Input data is stored
348 * in buffers and processed later.
349 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000350static void
Damien Miller95def091999-11-25 00:26:21 +1100351process_input(fd_set * readset)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000352{
Damien Miller95def091999-11-25 00:26:21 +1100353 int len;
354 char buf[16384];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000355
Damien Miller95def091999-11-25 00:26:21 +1100356 /* Read and buffer any input data from the client. */
357 if (FD_ISSET(connection_in, readset)) {
358 len = read(connection_in, buf, sizeof(buf));
359 if (len == 0) {
Damien Miller16aed052002-09-22 01:26:27 +1000360 verbose("Connection closed by %.100s",
361 get_remote_ipaddr());
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000362 connection_closed = 1;
363 if (compat20)
364 return;
Darren Tucker3e33cec2003-10-02 16:12:36 +1000365 cleanup_exit(255);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000366 } else if (len < 0) {
367 if (errno != EINTR && errno != EAGAIN) {
Damien Miller16aed052002-09-22 01:26:27 +1000368 verbose("Read error from remote host "
369 "%.100s: %.100s",
370 get_remote_ipaddr(), strerror(errno));
Darren Tucker3e33cec2003-10-02 16:12:36 +1000371 cleanup_exit(255);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000372 }
373 } else {
374 /* Buffer any received data. */
375 packet_process_incoming(buf, len);
Damien Miller95def091999-11-25 00:26:21 +1100376 }
Damien Miller95def091999-11-25 00:26:21 +1100377 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000378 if (compat20)
379 return;
380
Damien Miller95def091999-11-25 00:26:21 +1100381 /* Read and buffer any available stdout data from the program. */
382 if (!fdout_eof && FD_ISSET(fdout, readset)) {
383 len = read(fdout, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000384 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
385 /* do nothing */
386 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100387 fdout_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000388 } else {
Damien Miller95def091999-11-25 00:26:21 +1100389 buffer_append(&stdout_buffer, buf, len);
390 fdout_bytes += len;
391 }
392 }
393 /* Read and buffer any available stderr data from the program. */
394 if (!fderr_eof && FD_ISSET(fderr, readset)) {
395 len = read(fderr, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000396 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
397 /* do nothing */
398 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100399 fderr_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000400 } else {
Damien Miller95def091999-11-25 00:26:21 +1100401 buffer_append(&stderr_buffer, buf, len);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000402 }
Damien Miller95def091999-11-25 00:26:21 +1100403 }
404}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000405
Damien Miller95def091999-11-25 00:26:21 +1100406/*
407 * Sends data from internal buffers to client program stdin.
408 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000409static void
Damien Miller95def091999-11-25 00:26:21 +1100410process_output(fd_set * writeset)
411{
Ben Lindstromaa630de2001-02-10 23:44:47 +0000412 struct termios tio;
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000413 u_char *data;
414 u_int dlen;
Damien Miller95def091999-11-25 00:26:21 +1100415 int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000416
Damien Miller95def091999-11-25 00:26:21 +1100417 /* Write buffered data to program stdin. */
Damien Millerefb4afe2000-04-12 18:45:05 +1000418 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000419 data = buffer_ptr(&stdin_buffer);
420 dlen = buffer_len(&stdin_buffer);
421 len = write(fdin, data, dlen);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000422 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
423 /* do nothing */
424 } else if (len <= 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000425 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100426 close(fdin);
427 else
428 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100429 fdin = -1;
430 } else {
Ben Lindstromaa630de2001-02-10 23:44:47 +0000431 /* Successful write. */
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000432 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
433 tcgetattr(fdin, &tio) == 0 &&
Damien Miller79438cc2001-02-16 12:34:57 +1100434 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
Kevin Stevesb7f036f2001-02-15 17:27:15 +0000435 /*
436 * Simulate echo to reduce the impact of
437 * traffic analysis
438 */
Ben Lindstrome229b252001-03-05 06:28:06 +0000439 packet_send_ignore(len);
Ben Lindstromaa630de2001-02-10 23:44:47 +0000440 packet_send();
441 }
442 /* Consume the data from the buffer. */
Damien Miller95def091999-11-25 00:26:21 +1100443 buffer_consume(&stdin_buffer, len);
444 /* Update the count of bytes written to the program. */
445 stdin_bytes += len;
446 }
447 }
448 /* Send any buffered packet data to the client. */
449 if (FD_ISSET(connection_out, writeset))
450 packet_write_poll();
451}
452
453/*
454 * Wait until all buffered output has been sent to the client.
455 * This is used when the program terminates.
456 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000457static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000458drain_output(void)
Damien Miller95def091999-11-25 00:26:21 +1100459{
460 /* Send any buffered stdout data to the client. */
461 if (buffer_len(&stdout_buffer) > 0) {
462 packet_start(SSH_SMSG_STDOUT_DATA);
463 packet_put_string(buffer_ptr(&stdout_buffer),
464 buffer_len(&stdout_buffer));
465 packet_send();
466 /* Update the count of sent bytes. */
467 stdout_bytes += buffer_len(&stdout_buffer);
468 }
469 /* Send any buffered stderr data to the client. */
470 if (buffer_len(&stderr_buffer) > 0) {
471 packet_start(SSH_SMSG_STDERR_DATA);
472 packet_put_string(buffer_ptr(&stderr_buffer),
473 buffer_len(&stderr_buffer));
474 packet_send();
475 /* Update the count of sent bytes. */
476 stderr_bytes += buffer_len(&stderr_buffer);
477 }
478 /* Wait until all buffered data has been written to the client. */
479 packet_write_wait();
480}
481
Ben Lindstrombba81212001-06-25 05:01:22 +0000482static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000483process_buffered_input_packets(void)
Damien Millerb38eff82000-04-01 11:09:21 +1000484{
Ben Lindstrom8ac91062001-04-04 17:57:54 +0000485 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
Damien Millerb38eff82000-04-01 11:09:21 +1000486}
487
Damien Miller95def091999-11-25 00:26:21 +1100488/*
489 * Performs the interactive session. This handles data transmission between
490 * the client and the program. Note that the notion of stdin, stdout, and
491 * stderr in this function is sort of reversed: this function writes to
492 * stdin (of the child program), and reads from stdout and stderr (of the
493 * child program).
494 */
Damien Miller4af51302000-04-16 11:18:38 +1000495void
Damien Miller166fca82000-04-20 07:42:21 +1000496server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
Damien Miller95def091999-11-25 00:26:21 +1100497{
Damien Miller5e953212001-01-30 09:14:00 +1100498 fd_set *readset = NULL, *writeset = NULL;
Darren Tuckerc7a6fc42004-08-13 21:18:00 +1000499 int max_fd = 0;
500 u_int nalloc = 0;
Damien Miller166fca82000-04-20 07:42:21 +1000501 int wait_status; /* Status returned by wait(). */
502 pid_t wait_pid; /* pid returned by wait(). */
Damien Miller95def091999-11-25 00:26:21 +1100503 int waiting_termination = 0; /* Have displayed waiting close message. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000504 u_int max_time_milliseconds;
505 u_int previous_stdout_buffer_bytes;
506 u_int stdout_buffer_bytes;
Damien Miller95def091999-11-25 00:26:21 +1100507 int type;
508
509 debug("Entering interactive session.");
510
511 /* Initialize the SIGCHLD kludge. */
Damien Miller95def091999-11-25 00:26:21 +1100512 child_terminated = 0;
Kevin Stevese26a1552001-07-26 17:51:49 +0000513 mysignal(SIGCHLD, sigchld_handler);
Damien Miller95def091999-11-25 00:26:21 +1100514
Damien Miller24ecf612005-11-05 15:16:52 +1100515 if (!use_privsep) {
516 signal(SIGTERM, sigterm_handler);
517 signal(SIGINT, sigterm_handler);
518 signal(SIGQUIT, sigterm_handler);
519 }
520
Damien Miller95def091999-11-25 00:26:21 +1100521 /* Initialize our global variables. */
522 fdin = fdin_arg;
523 fdout = fdout_arg;
524 fderr = fderr_arg;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000525
526 /* nonblocking IO */
527 set_nonblock(fdin);
528 set_nonblock(fdout);
Damien Miller7d6656c2000-05-20 15:22:36 +1000529 /* we don't have stderr for interactive terminal sessions, see below */
530 if (fderr != -1)
531 set_nonblock(fderr);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000532
Damien Miller225736c2001-02-19 21:51:08 +1100533 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
534 fdin_is_tty = 1;
535
Damien Miller95def091999-11-25 00:26:21 +1100536 connection_in = packet_get_connection_in();
537 connection_out = packet_get_connection_out();
538
Damien Millerf6681a32001-12-21 14:53:11 +1100539 notify_setup();
540
Damien Miller95def091999-11-25 00:26:21 +1100541 previous_stdout_buffer_bytes = 0;
542
543 /* Set approximate I/O buffer size. */
544 if (packet_is_interactive())
545 buffer_high = 4096;
546 else
547 buffer_high = 64 * 1024;
548
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000549#if 0
Damien Miller95def091999-11-25 00:26:21 +1100550 /* Initialize max_fd to the maximum of the known file descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000551 max_fd = MAX(connection_in, connection_out);
552 max_fd = MAX(max_fd, fdin);
553 max_fd = MAX(max_fd, fdout);
Damien Miller5e953212001-01-30 09:14:00 +1100554 if (fderr != -1)
555 max_fd = MAX(max_fd, fderr);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000556#endif
Damien Miller95def091999-11-25 00:26:21 +1100557
558 /* Initialize Initialize buffers. */
559 buffer_init(&stdin_buffer);
560 buffer_init(&stdout_buffer);
561 buffer_init(&stderr_buffer);
562
Damien Miller5428f641999-11-25 11:54:57 +1100563 /*
564 * If we have no separate fderr (which is the case when we have a pty
565 * - there we cannot make difference between data sent to stdout and
566 * stderr), indicate that we have seen an EOF from stderr. This way
Damien Miller788f2122005-11-05 15:14:59 +1100567 * we don't need to check the descriptor everywhere.
Damien Miller5428f641999-11-25 11:54:57 +1100568 */
Damien Miller95def091999-11-25 00:26:21 +1100569 if (fderr == -1)
570 fderr_eof = 1;
571
Damien Millerb38eff82000-04-01 11:09:21 +1000572 server_init_dispatch();
573
Damien Miller95def091999-11-25 00:26:21 +1100574 /* Main loop of the server for the interactive session mode. */
575 for (;;) {
Damien Miller95def091999-11-25 00:26:21 +1100576
577 /* Process buffered packets from the client. */
578 process_buffered_input_packets();
579
Damien Miller5428f641999-11-25 11:54:57 +1100580 /*
581 * If we have received eof, and there is no more pending
582 * input data, cause a real eof by closing fdin.
583 */
Damien Miller95def091999-11-25 00:26:21 +1100584 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000585 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100586 close(fdin);
587 else
588 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100589 fdin = -1;
590 }
Damien Miller5428f641999-11-25 11:54:57 +1100591 /* Make packets from buffered stderr data to send to the client. */
Damien Miller95def091999-11-25 00:26:21 +1100592 make_packets_from_stderr_data();
593
Damien Miller5428f641999-11-25 11:54:57 +1100594 /*
595 * Make packets from buffered stdout data to send to the
596 * client. If there is very little to send, this arranges to
597 * not send them now, but to wait a short while to see if we
598 * are getting more data. This is necessary, as some systems
599 * wake up readers from a pty after each separate character.
600 */
Damien Miller95def091999-11-25 00:26:21 +1100601 max_time_milliseconds = 0;
602 stdout_buffer_bytes = buffer_len(&stdout_buffer);
603 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
604 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
605 /* try again after a while */
606 max_time_milliseconds = 10;
607 } else {
608 /* Send it now. */
609 make_packets_from_stdout_data();
610 }
611 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
612
613 /* Send channel data to the client. */
614 if (packet_not_very_much_data_to_write())
615 channel_output_poll();
616
Damien Miller5428f641999-11-25 11:54:57 +1100617 /*
618 * Bail out of the loop if the program has closed its output
619 * descriptors, and we have no more data to send to the
620 * client, and there is no pending buffered data.
621 */
Damien Miller43dc8da2000-11-29 15:55:17 +1100622 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
623 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
Damien Miller95def091999-11-25 00:26:21 +1100624 if (!channel_still_open())
Damien Millerb38eff82000-04-01 11:09:21 +1000625 break;
Damien Miller95def091999-11-25 00:26:21 +1100626 if (!waiting_termination) {
627 const char *s = "Waiting for forwarded connections to terminate...\r\n";
628 char *cp;
629 waiting_termination = 1;
630 buffer_append(&stderr_buffer, s, strlen(s));
631
632 /* Display list of open channels. */
633 cp = channel_open_message();
634 buffer_append(&stderr_buffer, cp, strlen(cp));
635 xfree(cp);
636 }
637 }
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000638 max_fd = MAX(connection_in, connection_out);
639 max_fd = MAX(max_fd, fdin);
640 max_fd = MAX(max_fd, fdout);
641 max_fd = MAX(max_fd, fderr);
Damien Millerf6681a32001-12-21 14:53:11 +1100642 max_fd = MAX(max_fd, notify_pipe[0]);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000643
Damien Miller95def091999-11-25 00:26:21 +1100644 /* Sleep in select() until we can do something. */
Damien Miller5e953212001-01-30 09:14:00 +1100645 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000646 &nalloc, max_time_milliseconds);
Damien Miller95def091999-11-25 00:26:21 +1100647
Damien Miller24ecf612005-11-05 15:16:52 +1100648 if (received_sigterm) {
649 logit("Exiting on signal %d", received_sigterm);
650 /* Clean up sessions, utmp, etc. */
651 cleanup_exit(255);
652 }
653
Damien Miller95def091999-11-25 00:26:21 +1100654 /* Process any channel events. */
Damien Miller5e953212001-01-30 09:14:00 +1100655 channel_after_select(readset, writeset);
Damien Miller95def091999-11-25 00:26:21 +1100656
657 /* Process input from the client and from program stdout/stderr. */
Damien Miller5e953212001-01-30 09:14:00 +1100658 process_input(readset);
Damien Miller95def091999-11-25 00:26:21 +1100659
660 /* Process output to the client and to program stdin. */
Damien Miller5e953212001-01-30 09:14:00 +1100661 process_output(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100662 }
Damien Miller5e953212001-01-30 09:14:00 +1100663 if (readset)
664 xfree(readset);
665 if (writeset)
666 xfree(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100667
Damien Miller95def091999-11-25 00:26:21 +1100668 /* Cleanup and termination code. */
669
670 /* Wait until all output has been sent to the client. */
671 drain_output();
672
673 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100674 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
Damien Miller95def091999-11-25 00:26:21 +1100675
676 /* Free and clear the buffers. */
677 buffer_free(&stdin_buffer);
678 buffer_free(&stdout_buffer);
679 buffer_free(&stderr_buffer);
680
681 /* Close the file descriptors. */
682 if (fdout != -1)
683 close(fdout);
684 fdout = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000685 fdout_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100686 if (fderr != -1)
687 close(fderr);
688 fderr = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000689 fderr_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100690 if (fdin != -1)
691 close(fdin);
692 fdin = -1;
693
Ben Lindstrom601e4362001-06-21 03:19:23 +0000694 channel_free_all();
Damien Miller95def091999-11-25 00:26:21 +1100695
Damien Miller95def091999-11-25 00:26:21 +1100696 /* We no longer want our SIGCHLD handler to be called. */
Kevin Stevese26a1552001-07-26 17:51:49 +0000697 mysignal(SIGCHLD, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100698
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000699 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
700 if (errno != EINTR)
701 packet_disconnect("wait: %.100s", strerror(errno));
702 if (wait_pid != pid)
Ben Lindstromce0f6342002-06-11 16:42:49 +0000703 error("Strange, wait returned pid %ld, expected %ld",
704 (long)wait_pid, (long)pid);
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000705
Damien Miller95def091999-11-25 00:26:21 +1100706 /* Check if it exited normally. */
707 if (WIFEXITED(wait_status)) {
708 /* Yes, normal exit. Get exit status and send it to the client. */
709 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
710 packet_start(SSH_SMSG_EXITSTATUS);
711 packet_put_int(WEXITSTATUS(wait_status));
712 packet_send();
713 packet_write_wait();
714
Damien Miller5428f641999-11-25 11:54:57 +1100715 /*
716 * Wait for exit confirmation. Note that there might be
717 * other packets coming before it; however, the program has
718 * already died so we just ignore them. The client is
719 * supposed to respond with the confirmation when it receives
720 * the exit status.
721 */
Damien Miller95def091999-11-25 00:26:21 +1100722 do {
Damien Millerdff50992002-01-22 23:16:32 +1100723 type = packet_read();
Damien Miller95def091999-11-25 00:26:21 +1100724 }
725 while (type != SSH_CMSG_EXIT_CONFIRMATION);
726
727 debug("Received exit confirmation.");
728 return;
729 }
730 /* Check if the program terminated due to a signal. */
731 if (WIFSIGNALED(wait_status))
732 packet_disconnect("Command terminated on signal %d.",
733 WTERMSIG(wait_status));
734
735 /* Some weird exit cause. Just exit. */
736 packet_disconnect("wait returned status %04x.", wait_status);
737 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000738}
Damien Millerb38eff82000-04-01 11:09:21 +1000739
Damien Miller3ec27592001-10-12 11:35:04 +1000740static void
741collect_children(void)
742{
743 pid_t pid;
744 sigset_t oset, nset;
745 int status;
746
747 /* block SIGCHLD while we check for dead children */
748 sigemptyset(&nset);
749 sigaddset(&nset, SIGCHLD);
750 sigprocmask(SIG_BLOCK, &nset, &oset);
751 if (child_terminated) {
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000752 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
753 (pid < 0 && errno == EINTR))
754 if (pid > 0)
755 session_close_by_pid(pid, status);
Damien Miller3ec27592001-10-12 11:35:04 +1000756 child_terminated = 0;
757 }
758 sigprocmask(SIG_SETMASK, &oset, NULL);
759}
760
Damien Miller4af51302000-04-16 11:18:38 +1000761void
Ben Lindstrombddd5512001-07-04 04:53:53 +0000762server_loop2(Authctxt *authctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000763{
Damien Miller5e953212001-01-30 09:14:00 +1100764 fd_set *readset = NULL, *writeset = NULL;
Damien Miller3ec27592001-10-12 11:35:04 +1000765 int rekeying = 0, max_fd, nalloc = 0;
Damien Millerefb4afe2000-04-12 18:45:05 +1000766
767 debug("Entering interactive session for SSH2.");
768
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000769 mysignal(SIGCHLD, sigchld_handler);
Damien Millerefb4afe2000-04-12 18:45:05 +1000770 child_terminated = 0;
771 connection_in = packet_get_connection_in();
772 connection_out = packet_get_connection_out();
Damien Miller5e953212001-01-30 09:14:00 +1100773
Damien Miller24ecf612005-11-05 15:16:52 +1100774 if (!use_privsep) {
775 signal(SIGTERM, sigterm_handler);
776 signal(SIGINT, sigterm_handler);
777 signal(SIGQUIT, sigterm_handler);
778 }
779
Damien Millerf6681a32001-12-21 14:53:11 +1100780 notify_setup();
781
Damien Miller5e953212001-01-30 09:14:00 +1100782 max_fd = MAX(connection_in, connection_out);
Damien Millerf6681a32001-12-21 14:53:11 +1100783 max_fd = MAX(max_fd, notify_pipe[0]);
784
Damien Millerefb4afe2000-04-12 18:45:05 +1000785 server_init_dispatch();
786
787 for (;;) {
788 process_buffered_input_packets();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000789
Ben Lindstroma3700052001-04-05 23:26:32 +0000790 rekeying = (xxx_kex != NULL && !xxx_kex->done);
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000791
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000792 if (!rekeying && packet_not_very_much_data_to_write())
Damien Millerefb4afe2000-04-12 18:45:05 +1000793 channel_output_poll();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000794 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000795 &nalloc, 0);
Damien Miller52b77be2001-10-10 15:14:37 +1000796
Damien Miller24ecf612005-11-05 15:16:52 +1100797 if (received_sigterm) {
798 logit("Exiting on signal %d", received_sigterm);
799 /* Clean up sessions, utmp, etc. */
800 cleanup_exit(255);
801 }
802
Damien Miller3ec27592001-10-12 11:35:04 +1000803 collect_children();
Damien Millera5539d22003-04-09 20:50:06 +1000804 if (!rekeying) {
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000805 channel_after_select(readset, writeset);
Damien Millera5539d22003-04-09 20:50:06 +1000806 if (packet_need_rekeying()) {
807 debug("need rekeying");
808 xxx_kex->done = 0;
809 kex_send_kexinit(xxx_kex);
810 }
811 }
Damien Miller5e953212001-01-30 09:14:00 +1100812 process_input(readset);
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000813 if (connection_closed)
814 break;
Damien Miller5e953212001-01-30 09:14:00 +1100815 process_output(writeset);
Damien Millerefb4afe2000-04-12 18:45:05 +1000816 }
Damien Miller3ec27592001-10-12 11:35:04 +1000817 collect_children();
818
Damien Miller5e953212001-01-30 09:14:00 +1100819 if (readset)
820 xfree(readset);
821 if (writeset)
822 xfree(writeset);
823
Damien Miller52b77be2001-10-10 15:14:37 +1000824 /* free all channels, no more reads and writes */
825 channel_free_all();
Ben Lindstrom4983d5e2001-07-04 05:17:40 +0000826
Damien Miller3ec27592001-10-12 11:35:04 +1000827 /* free remaining sessions, e.g. remove wtmp entries */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000828 session_destroy_all(NULL);
Damien Millerefb4afe2000-04-12 18:45:05 +1000829}
830
Ben Lindstrombba81212001-06-25 05:01:22 +0000831static void
Damien Millerb5820f42003-12-17 16:27:32 +1100832server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000833{
Damien Millerb5820f42003-12-17 16:27:32 +1100834 debug("Got %d/%u for keepalive", type, seq);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100835 /*
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000836 * reset timeout, since we got a sane answer from the client.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000837 * even if this was generated by something other than
838 * the bogus CHANNEL_REQUEST we send for keepalives.
839 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100840 client_alive_timeouts = 0;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000841}
842
Ben Lindstrombba81212001-06-25 05:01:22 +0000843static void
Damien Miller630d6f42002-01-22 23:17:30 +1100844server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000845{
846 char *data;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000847 u_int data_len;
Damien Millerb38eff82000-04-01 11:09:21 +1000848
849 /* Stdin data from the client. Append it to the buffer. */
850 /* Ignore any data if the client has closed stdin. */
851 if (fdin == -1)
852 return;
853 data = packet_get_string(&data_len);
Damien Miller48b03fc2002-01-22 23:11:40 +1100854 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000855 buffer_append(&stdin_buffer, data, data_len);
856 memset(data, 0, data_len);
857 xfree(data);
858}
859
Ben Lindstrombba81212001-06-25 05:01:22 +0000860static void
Damien Miller630d6f42002-01-22 23:17:30 +1100861server_input_eof(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000862{
863 /*
864 * Eof from the client. The stdin descriptor to the
865 * program will be closed when all buffered data has
866 * drained.
867 */
868 debug("EOF received for stdin.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100869 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000870 stdin_eof = 1;
871}
872
Ben Lindstrombba81212001-06-25 05:01:22 +0000873static void
Damien Miller630d6f42002-01-22 23:17:30 +1100874server_input_window_size(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000875{
876 int row = packet_get_int();
877 int col = packet_get_int();
878 int xpixel = packet_get_int();
879 int ypixel = packet_get_int();
880
881 debug("Window change received.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100882 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000883 if (fdin != -1)
884 pty_change_window_size(fdin, row, col, xpixel, ypixel);
885}
886
Ben Lindstrombba81212001-06-25 05:01:22 +0000887static Channel *
Damien Millerfb1310e2004-01-21 11:02:50 +1100888server_request_direct_tcpip(void)
Damien Millerefb4afe2000-04-12 18:45:05 +1000889{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000890 Channel *c;
891 int sock;
Damien Miller4af51302000-04-16 11:18:38 +1000892 char *target, *originator;
893 int target_port, originator_port;
Damien Millerefb4afe2000-04-12 18:45:05 +1000894
Damien Miller4af51302000-04-16 11:18:38 +1000895 target = packet_get_string(NULL);
896 target_port = packet_get_int();
Damien Millerefb4afe2000-04-12 18:45:05 +1000897 originator = packet_get_string(NULL);
898 originator_port = packet_get_int();
Damien Miller48b03fc2002-01-22 23:11:40 +1100899 packet_check_eom();
Damien Millerb1715dc2000-05-30 13:44:51 +1000900
Damien Miller0bc1bd82000-11-13 22:57:25 +1100901 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
Damien Miller0dc1bef2005-07-17 17:22:45 +1000902 originator, originator_port, target, target_port);
Damien Millerf6d9e222000-06-18 14:50:44 +1000903
Damien Millerefb4afe2000-04-12 18:45:05 +1000904 /* XXX check permission */
Damien Miller4af51302000-04-16 11:18:38 +1000905 sock = channel_connect_to(target, target_port);
906 xfree(target);
Damien Millerefb4afe2000-04-12 18:45:05 +1000907 xfree(originator);
908 if (sock < 0)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100909 return NULL;
Damien Millerfb1310e2004-01-21 11:02:50 +1100910 c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
Damien Millere4340be2000-09-16 13:29:08 +1100911 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000912 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000913 return c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100914}
915
Ben Lindstrombba81212001-06-25 05:01:22 +0000916static Channel *
Damien Millerd27b9472005-12-13 19:29:02 +1100917server_request_tun(void)
918{
919 Channel *c = NULL;
Damien Miller7b58e802005-12-13 19:33:19 +1100920 int mode, tun;
921 int sock;
Damien Millerd27b9472005-12-13 19:29:02 +1100922
Damien Miller7b58e802005-12-13 19:33:19 +1100923 mode = packet_get_int();
924 switch (mode) {
925 case SSH_TUNMODE_POINTOPOINT:
926 case SSH_TUNMODE_ETHERNET:
927 break;
928 default:
929 packet_send_debug("Unsupported tunnel device mode.");
930 return NULL;
931 }
932 if ((options.permit_tun & mode) == 0) {
933 packet_send_debug("Server has rejected tunnel device "
934 "forwarding");
Damien Millerd27b9472005-12-13 19:29:02 +1100935 return NULL;
936 }
937
938 tun = packet_get_int();
Darren Tucker0d0e8f02005-12-20 16:08:42 +1100939 if (forced_tun_device != -1) {
Damien Miller7b58e802005-12-13 19:33:19 +1100940 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
Damien Millerd27b9472005-12-13 19:29:02 +1100941 goto done;
942 tun = forced_tun_device;
943 }
Damien Miller7b58e802005-12-13 19:33:19 +1100944 sock = tun_open(tun, mode);
Damien Millerd27b9472005-12-13 19:29:02 +1100945 if (sock < 0)
946 goto done;
947 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
948 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
949 c->datagram = 1;
Damien Miller598bbc22005-12-31 16:33:36 +1100950#if defined(SSH_TUN_FILTER)
951 if (mode == SSH_TUNMODE_POINTOPOINT)
952 channel_register_filter(c->self, sys_tun_infilter,
953 sys_tun_outfilter);
954#endif
Damien Millerd27b9472005-12-13 19:29:02 +1100955
956 done:
957 if (c == NULL)
958 packet_send_debug("Failed to open the tunnel device.");
959 return c;
960}
961
962static Channel *
Damien Millerfb1310e2004-01-21 11:02:50 +1100963server_request_session(void)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100964{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000965 Channel *c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100966
967 debug("input_session_request");
Damien Miller48b03fc2002-01-22 23:11:40 +1100968 packet_check_eom();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100969 /*
970 * A server session has no fd to read or write until a
971 * CHANNEL_REQUEST for a shell is made, so we set the type to
972 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
973 * CHANNEL_REQUEST messages is registered.
974 */
Damien Millerfb1310e2004-01-21 11:02:50 +1100975 c = channel_new("session", SSH_CHANNEL_LARVAL,
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000976 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000977 0, "server-session", 1);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000978 if (session_open(the_authctxt, c->self) != 1) {
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000979 debug("session open failed, free channel %d", c->self);
980 channel_free(c);
981 return NULL;
982 }
Damien Miller39eda6e2005-11-05 14:52:50 +1100983 channel_register_cleanup(c->self, session_close_by_channel, 0);
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000984 return c;
Damien Millerefb4afe2000-04-12 18:45:05 +1000985}
986
Ben Lindstrombba81212001-06-25 05:01:22 +0000987static void
Damien Miller630d6f42002-01-22 23:17:30 +1100988server_input_channel_open(int type, u_int32_t seq, void *ctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000989{
990 Channel *c = NULL;
991 char *ctype;
Damien Millerefb4afe2000-04-12 18:45:05 +1000992 int rchan;
Ben Lindstrom4fed2be2002-06-25 23:17:36 +0000993 u_int rmaxpack, rwindow, len;
Damien Millerefb4afe2000-04-12 18:45:05 +1000994
995 ctype = packet_get_string(&len);
996 rchan = packet_get_int();
997 rwindow = packet_get_int();
998 rmaxpack = packet_get_int();
999
Damien Miller62cee002000-09-23 17:15:56 +11001000 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
Damien Millerefb4afe2000-04-12 18:45:05 +10001001 ctype, rchan, rwindow, rmaxpack);
1002
1003 if (strcmp(ctype, "session") == 0) {
Damien Millerfb1310e2004-01-21 11:02:50 +11001004 c = server_request_session();
Damien Millerefb4afe2000-04-12 18:45:05 +10001005 } else if (strcmp(ctype, "direct-tcpip") == 0) {
Damien Millerfb1310e2004-01-21 11:02:50 +11001006 c = server_request_direct_tcpip();
Damien Millerd27b9472005-12-13 19:29:02 +11001007 } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1008 c = server_request_tun();
Damien Millerefb4afe2000-04-12 18:45:05 +10001009 }
1010 if (c != NULL) {
Damien Miller0bc1bd82000-11-13 22:57:25 +11001011 debug("server_input_channel_open: confirm %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +10001012 c->remote_id = rchan;
1013 c->remote_window = rwindow;
1014 c->remote_maxpacket = rmaxpack;
Ben Lindstrom69128662001-05-08 20:07:39 +00001015 if (c->type != SSH_CHANNEL_CONNECTING) {
1016 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1017 packet_put_int(c->remote_id);
1018 packet_put_int(c->self);
1019 packet_put_int(c->local_window);
1020 packet_put_int(c->local_maxpacket);
1021 packet_send();
1022 }
Damien Millerefb4afe2000-04-12 18:45:05 +10001023 } else {
Damien Miller0bc1bd82000-11-13 22:57:25 +11001024 debug("server_input_channel_open: failure %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +10001025 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1026 packet_put_int(rchan);
1027 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
Ben Lindstromf3436742001-04-29 19:52:00 +00001028 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
Ben Lindstrom69128662001-05-08 20:07:39 +00001029 packet_put_cstring("open failed");
Ben Lindstromf3436742001-04-29 19:52:00 +00001030 packet_put_cstring("");
1031 }
Damien Millerefb4afe2000-04-12 18:45:05 +10001032 packet_send();
1033 }
1034 xfree(ctype);
1035}
1036
Ben Lindstrombba81212001-06-25 05:01:22 +00001037static void
Damien Miller630d6f42002-01-22 23:17:30 +11001038server_input_global_request(int type, u_int32_t seq, void *ctxt)
Damien Miller0bc1bd82000-11-13 22:57:25 +11001039{
1040 char *rtype;
1041 int want_reply;
1042 int success = 0;
1043
1044 rtype = packet_get_string(NULL);
1045 want_reply = packet_get_char();
1046 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
Kevin Stevesef4eea92001-02-05 12:42:17 +00001047
Ben Lindstrom7bb8b492001-03-17 00:47:54 +00001048 /* -R style forwarding */
Damien Miller0bc1bd82000-11-13 22:57:25 +11001049 if (strcmp(rtype, "tcpip-forward") == 0) {
1050 struct passwd *pw;
1051 char *listen_address;
1052 u_short listen_port;
1053
Darren Tucker3e33cec2003-10-02 16:12:36 +10001054 pw = the_authctxt->pw;
Damien Miller4bb1dd32003-11-18 22:01:25 +11001055 if (pw == NULL || !the_authctxt->valid)
Damien Miller3e3b5142003-11-17 21:13:40 +11001056 fatal("server_input_global_request: no/invalid user");
Damien Miller9fc7c692003-06-04 22:50:54 +10001057 listen_address = packet_get_string(NULL);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001058 listen_port = (u_short)packet_get_int();
1059 debug("server_input_global_request: tcpip-forward listen %s port %d",
1060 listen_address, listen_port);
1061
1062 /* check permissions */
1063 if (!options.allow_tcp_forwarding ||
Ben Lindstrom99a4e142002-07-09 14:06:40 +00001064 no_port_forwarding_flag
1065#ifndef NO_IPPORT_RESERVED_CONCEPT
1066 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
1067#endif
Damien Millerb6f72f52005-07-17 17:26:43 +10001068 ) {
Damien Miller0bc1bd82000-11-13 22:57:25 +11001069 success = 0;
1070 packet_send_debug("Server has disabled port forwarding.");
1071 } else {
1072 /* Start listening on the port */
Damien Millerb16461c2002-01-22 23:29:22 +11001073 success = channel_setup_remote_fwd_listener(
1074 listen_address, listen_port, options.gateway_ports);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001075 }
1076 xfree(listen_address);
Darren Tuckere7066df2004-05-24 10:18:05 +10001077 } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1078 char *cancel_address;
1079 u_short cancel_port;
1080
1081 cancel_address = packet_get_string(NULL);
1082 cancel_port = (u_short)packet_get_int();
1083 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1084 cancel_address, cancel_port);
1085
1086 success = channel_cancel_rport_listener(cancel_address,
1087 cancel_port);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001088 }
1089 if (want_reply) {
1090 packet_start(success ?
1091 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1092 packet_send();
1093 packet_write_wait();
1094 }
1095 xfree(rtype);
1096}
Damien Millerc7ef63d2002-02-05 12:21:42 +11001097static void
1098server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1099{
1100 Channel *c;
1101 int id, reply, success = 0;
1102 char *rtype;
1103
1104 id = packet_get_int();
1105 rtype = packet_get_string(NULL);
1106 reply = packet_get_char();
1107
1108 debug("server_input_channel_req: channel %d request %s reply %d",
1109 id, rtype, reply);
1110
1111 if ((c = channel_lookup(id)) == NULL)
1112 packet_disconnect("server_input_channel_req: "
1113 "unknown channel %d", id);
1114 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1115 success = session_input_channel_req(c, rtype);
1116 if (reply) {
1117 packet_start(success ?
1118 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1119 packet_put_int(c->remote_id);
1120 packet_send();
1121 }
1122 xfree(rtype);
1123}
Damien Miller0bc1bd82000-11-13 22:57:25 +11001124
Ben Lindstrombba81212001-06-25 05:01:22 +00001125static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001126server_init_dispatch_20(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10001127{
1128 debug("server_init_dispatch_20");
1129 dispatch_init(&dispatch_protocol_error);
1130 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1131 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1132 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1133 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1134 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1135 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1136 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
Damien Millerc7ef63d2002-02-05 12:21:42 +11001137 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
Damien Millerefb4afe2000-04-12 18:45:05 +10001138 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001139 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
Ben Lindstrom5744dc42001-04-13 23:28:01 +00001140 /* client_alive */
Damien Millerb5820f42003-12-17 16:27:32 +11001141 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1142 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1143 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001144 /* rekeying */
1145 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
Damien Millerefb4afe2000-04-12 18:45:05 +10001146}
Ben Lindstrombba81212001-06-25 05:01:22 +00001147static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001148server_init_dispatch_13(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001149{
1150 debug("server_init_dispatch_13");
1151 dispatch_init(NULL);
1152 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1153 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1154 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1155 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1156 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1157 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1158 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1159 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1160 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1161}
Ben Lindstrombba81212001-06-25 05:01:22 +00001162static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001163server_init_dispatch_15(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001164{
1165 server_init_dispatch_13();
1166 debug("server_init_dispatch_15");
1167 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1168 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1169}
Ben Lindstrombba81212001-06-25 05:01:22 +00001170static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001171server_init_dispatch(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001172{
Damien Millerefb4afe2000-04-12 18:45:05 +10001173 if (compat20)
1174 server_init_dispatch_20();
1175 else if (compat13)
Damien Millerb38eff82000-04-01 11:09:21 +10001176 server_init_dispatch_13();
1177 else
1178 server_init_dispatch_15();
1179}