blob: a953902736a69df0f602dc9e04c73cfd53ee1b7e [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 Tucker502d3842003-06-28 12:38:01 +100038RCSID("$OpenBSD: serverloop.c,v 1.110 2003/06/24 08:23:46 markus 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;
Ben Lindstrombddd5512001-07-04 04:53:53 +000063static Authctxt *xxx_authctxt;
Ben Lindstrom8ac91062001-04-04 17:57:54 +000064
Damien Millerd4a8b7e1999-10-27 13:42:43 +100065static Buffer stdin_buffer; /* Buffer for stdin data. */
66static Buffer stdout_buffer; /* Buffer for stdout data. */
67static Buffer stderr_buffer; /* Buffer for stderr data. */
68static int fdin; /* Descriptor for stdin (for writing) */
69static int fdout; /* Descriptor for stdout (for reading);
70 May be same number as fdin. */
71static int fderr; /* Descriptor for stderr. May be -1. */
72static long stdin_bytes = 0; /* Number of bytes written to stdin. */
73static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
74static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
75static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
76static int stdin_eof = 0; /* EOF message received from client. */
77static int fdout_eof = 0; /* EOF encountered reading from fdout. */
78static int fderr_eof = 0; /* EOF encountered readung from fderr. */
Damien Miller225736c2001-02-19 21:51:08 +110079static int fdin_is_tty = 0; /* fdin points to a tty. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100080static int connection_in; /* Connection to client (input). */
81static int connection_out; /* Connection to client (output). */
Ben Lindstrome34ab4c2001-04-07 01:12:11 +000082static int connection_closed = 0; /* Connection to client closed. */
83static u_int buffer_high; /* "Soft" max buffer size. */
Damien Miller8c3902a2001-10-10 15:01:40 +100084static int client_alive_timeouts = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100085
Damien Miller5428f641999-11-25 11:54:57 +110086/*
87 * This SIGCHLD kludge is used to detect when the child exits. The server
88 * will exit after that, as soon as forwarded connections have terminated.
89 */
Ben Lindstrombba81212001-06-25 05:01:22 +000090
Ben Lindstrom5e71c542001-12-06 16:48:14 +000091static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100092
Ben Lindstrombba81212001-06-25 05:01:22 +000093/* prototypes */
94static void server_init_dispatch(void);
Damien Millerb38eff82000-04-01 11:09:21 +100095
Damien Millerf6681a32001-12-21 14:53:11 +110096/*
97 * we write to this pipe if a SIGCHLD is caught in order to avoid
98 * the race between select() and child_terminated
99 */
100static int notify_pipe[2];
101static void
102notify_setup(void)
103{
104 if (pipe(notify_pipe) < 0) {
105 error("pipe(notify_pipe) failed %s", strerror(errno));
106 } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
107 (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
108 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
109 close(notify_pipe[0]);
110 close(notify_pipe[1]);
111 } else {
112 set_nonblock(notify_pipe[0]);
113 set_nonblock(notify_pipe[1]);
114 return;
115 }
116 notify_pipe[0] = -1; /* read end */
117 notify_pipe[1] = -1; /* write end */
118}
119static void
120notify_parent(void)
121{
122 if (notify_pipe[1] != -1)
123 write(notify_pipe[1], "", 1);
124}
125static void
126notify_prepare(fd_set *readset)
127{
128 if (notify_pipe[0] != -1)
129 FD_SET(notify_pipe[0], readset);
130}
131static void
132notify_done(fd_set *readset)
133{
134 char c;
135
136 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
137 while (read(notify_pipe[0], &c, 1) != -1)
138 debug2("notify_done: reading");
139}
140
Ben Lindstrombba81212001-06-25 05:01:22 +0000141static void
Damien Miller95def091999-11-25 00:26:21 +1100142sigchld_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000143{
Damien Miller95def091999-11-25 00:26:21 +1100144 int save_errno = errno;
Damien Millerefb4afe2000-04-12 18:45:05 +1000145 debug("Received SIGCHLD.");
146 child_terminated = 1;
Tim Rice81ed5182002-09-25 17:38:46 -0700147#ifndef _UNICOS
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000148 mysignal(SIGCHLD, sigchld_handler);
Tim Rice81ed5182002-09-25 17:38:46 -0700149#endif
Damien Millerf6681a32001-12-21 14:53:11 +1100150 notify_parent();
Damien Millerefb4afe2000-04-12 18:45:05 +1000151 errno = save_errno;
152}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000153
Damien Miller95def091999-11-25 00:26:21 +1100154/*
Damien Miller95def091999-11-25 00:26:21 +1100155 * Make packets from buffered stderr data, and buffer it for sending
156 * to the client.
157 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000158static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000159make_packets_from_stderr_data(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000160{
Darren Tucker502d3842003-06-28 12:38:01 +1000161 u_int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000162
Damien Miller95def091999-11-25 00:26:21 +1100163 /* Send buffered stderr data to the client. */
164 while (buffer_len(&stderr_buffer) > 0 &&
Damien Miller037a0dc1999-12-07 15:38:31 +1100165 packet_not_very_much_data_to_write()) {
Damien Miller95def091999-11-25 00:26:21 +1100166 len = buffer_len(&stderr_buffer);
167 if (packet_is_interactive()) {
168 if (len > 512)
169 len = 512;
170 } else {
171 /* Keep the packets at reasonable size. */
172 if (len > packet_get_maxsize())
173 len = packet_get_maxsize();
174 }
175 packet_start(SSH_SMSG_STDERR_DATA);
176 packet_put_string(buffer_ptr(&stderr_buffer), len);
177 packet_send();
178 buffer_consume(&stderr_buffer, len);
179 stderr_bytes += len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000180 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000181}
182
Damien Miller95def091999-11-25 00:26:21 +1100183/*
184 * Make packets from buffered stdout data, and buffer it for sending to the
185 * client.
186 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000187static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000188make_packets_from_stdout_data(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000189{
Darren Tucker502d3842003-06-28 12:38:01 +1000190 u_int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000191
Damien Miller95def091999-11-25 00:26:21 +1100192 /* Send buffered stdout data to the client. */
193 while (buffer_len(&stdout_buffer) > 0 &&
Damien Miller037a0dc1999-12-07 15:38:31 +1100194 packet_not_very_much_data_to_write()) {
Damien Miller95def091999-11-25 00:26:21 +1100195 len = buffer_len(&stdout_buffer);
196 if (packet_is_interactive()) {
197 if (len > 512)
198 len = 512;
199 } else {
200 /* Keep the packets at reasonable size. */
201 if (len > packet_get_maxsize())
Kevin Stevesef4eea92001-02-05 12:42:17 +0000202 len = packet_get_maxsize();
Damien Miller95def091999-11-25 00:26:21 +1100203 }
204 packet_start(SSH_SMSG_STDOUT_DATA);
205 packet_put_string(buffer_ptr(&stdout_buffer), len);
206 packet_send();
207 buffer_consume(&stdout_buffer, len);
208 stdout_bytes += len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000209 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000210}
211
Damien Miller8c3902a2001-10-10 15:01:40 +1000212static void
213client_alive_check(void)
214{
Damien Miller056cf732002-01-22 23:21:39 +1100215 static int had_channel = 0;
Damien Miller8c3902a2001-10-10 15:01:40 +1000216 int id;
217
Damien Miller056cf732002-01-22 23:21:39 +1100218 id = channel_find_open();
219 if (id == -1) {
220 if (!had_channel)
221 return;
222 packet_disconnect("No open channels after timeout!");
223 }
224 had_channel = 1;
225
Damien Miller8c3902a2001-10-10 15:01:40 +1000226 /* timeout, check to see how many we have had */
227 if (++client_alive_timeouts > options.client_alive_count_max)
228 packet_disconnect("Timeout, your session not responding.");
229
Damien Miller8c3902a2001-10-10 15:01:40 +1000230 /*
231 * send a bogus channel request with "wantreply",
232 * we should get back a failure
233 */
234 channel_request_start(id, "keepalive@openssh.com", 1);
235 packet_send();
236}
237
Damien Miller95def091999-11-25 00:26:21 +1100238/*
239 * Sleep in select() until we can do something. This will initialize the
240 * select masks. Upon return, the masks will indicate which descriptors
241 * have data or can accept data. Optionally, a maximum time can be specified
242 * for the duration of the wait (0 = infinite).
243 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000244static void
Damien Miller5e953212001-01-30 09:14:00 +1100245wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000246 int *nallocp, u_int max_time_milliseconds)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000247{
Damien Miller95def091999-11-25 00:26:21 +1100248 struct timeval tv, *tvp;
249 int ret;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000250 int client_alive_scheduled = 0;
251
252 /*
Damien Miller9f0f5c62001-12-21 14:45:46 +1100253 * if using client_alive, set the max timeout accordingly,
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000254 * and indicate that this particular timeout was for client
255 * alive by setting the client_alive_scheduled flag.
256 *
257 * this could be randomized somewhat to make traffic
Damien Miller9f0f5c62001-12-21 14:45:46 +1100258 * analysis more difficult, but we're not doing it yet.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000259 */
Ben Lindstrom36857f62001-07-18 15:48:57 +0000260 if (compat20 &&
261 max_time_milliseconds == 0 && options.client_alive_interval) {
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000262 client_alive_scheduled = 1;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000263 max_time_milliseconds = options.client_alive_interval * 1000;
Ben Lindstrom36857f62001-07-18 15:48:57 +0000264 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000265
Damien Miller5e953212001-01-30 09:14:00 +1100266 /* Allocate and update select() masks for channel descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000267 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000268
Damien Millerefb4afe2000-04-12 18:45:05 +1000269 if (compat20) {
Damien Milleraf5f2e62001-10-10 15:01:16 +1000270#if 0
Damien Millere247cc42000-05-07 12:03:14 +1000271 /* wrong: bad condition XXX */
Damien Millerefb4afe2000-04-12 18:45:05 +1000272 if (channel_not_very_much_buffered_data())
Damien Milleraf5f2e62001-10-10 15:01:16 +1000273#endif
274 FD_SET(connection_in, *readsetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000275 } else {
Damien Millerb1715dc2000-05-30 13:44:51 +1000276 /*
277 * Read packets from the client unless we have too much
278 * buffered stdin or channel data.
279 */
280 if (buffer_len(&stdin_buffer) < buffer_high &&
Damien Millerefb4afe2000-04-12 18:45:05 +1000281 channel_not_very_much_buffered_data())
Damien Miller5e953212001-01-30 09:14:00 +1100282 FD_SET(connection_in, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000283 /*
284 * If there is not too much data already buffered going to
285 * the client, try to get some more data from the program.
286 */
287 if (packet_not_very_much_data_to_write()) {
288 if (!fdout_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100289 FD_SET(fdout, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000290 if (!fderr_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100291 FD_SET(fderr, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000292 }
293 /*
294 * If we have buffered data, try to write some of that data
295 * to the program.
296 */
297 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
Damien Miller5e953212001-01-30 09:14:00 +1100298 FD_SET(fdin, *writesetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000299 }
Damien Millerf6681a32001-12-21 14:53:11 +1100300 notify_prepare(*readsetp);
Damien Miller95def091999-11-25 00:26:21 +1100301
Damien Miller5428f641999-11-25 11:54:57 +1100302 /*
303 * If we have buffered packet data going to the client, mark that
304 * descriptor.
305 */
Damien Miller95def091999-11-25 00:26:21 +1100306 if (packet_have_data_to_write())
Damien Miller5e953212001-01-30 09:14:00 +1100307 FD_SET(connection_out, *writesetp);
Damien Miller95def091999-11-25 00:26:21 +1100308
Damien Miller5428f641999-11-25 11:54:57 +1100309 /*
310 * If child has terminated and there is enough buffer space to read
311 * from it, then read as much as is available and exit.
312 */
Damien Miller95def091999-11-25 00:26:21 +1100313 if (child_terminated && packet_not_very_much_data_to_write())
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000314 if (max_time_milliseconds == 0 || client_alive_scheduled)
Damien Miller95def091999-11-25 00:26:21 +1100315 max_time_milliseconds = 100;
316
317 if (max_time_milliseconds == 0)
318 tvp = NULL;
319 else {
320 tv.tv_sec = max_time_milliseconds / 1000;
321 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
322 tvp = &tv;
323 }
324
325 /* Wait for something to happen, or the timeout to expire. */
Damien Miller5e953212001-01-30 09:14:00 +1100326 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
Damien Miller95def091999-11-25 00:26:21 +1100327
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000328 if (ret == -1) {
Damien Miller79faeff2001-11-12 11:06:32 +1100329 memset(*readsetp, 0, *nallocp);
330 memset(*writesetp, 0, *nallocp);
Damien Miller95def091999-11-25 00:26:21 +1100331 if (errno != EINTR)
332 error("select: %.100s", strerror(errno));
Damien Miller3ec27592001-10-12 11:35:04 +1000333 } else if (ret == 0 && client_alive_scheduled)
Damien Miller8c3902a2001-10-10 15:01:40 +1000334 client_alive_check();
Damien Millerf6681a32001-12-21 14:53:11 +1100335
336 notify_done(*readsetp);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000337}
338
Damien Miller95def091999-11-25 00:26:21 +1100339/*
340 * Processes input from the client and the program. Input data is stored
341 * in buffers and processed later.
342 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000343static void
Damien Miller95def091999-11-25 00:26:21 +1100344process_input(fd_set * readset)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000345{
Damien Miller95def091999-11-25 00:26:21 +1100346 int len;
347 char buf[16384];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000348
Damien Miller95def091999-11-25 00:26:21 +1100349 /* Read and buffer any input data from the client. */
350 if (FD_ISSET(connection_in, readset)) {
351 len = read(connection_in, buf, sizeof(buf));
352 if (len == 0) {
Damien Miller16aed052002-09-22 01:26:27 +1000353 verbose("Connection closed by %.100s",
354 get_remote_ipaddr());
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000355 connection_closed = 1;
356 if (compat20)
357 return;
Damien Miller95def091999-11-25 00:26:21 +1100358 fatal_cleanup();
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000359 } else if (len < 0) {
360 if (errno != EINTR && errno != EAGAIN) {
Damien Miller16aed052002-09-22 01:26:27 +1000361 verbose("Read error from remote host "
362 "%.100s: %.100s",
363 get_remote_ipaddr(), strerror(errno));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000364 fatal_cleanup();
365 }
366 } else {
367 /* Buffer any received data. */
368 packet_process_incoming(buf, len);
Damien Miller95def091999-11-25 00:26:21 +1100369 }
Damien Miller95def091999-11-25 00:26:21 +1100370 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000371 if (compat20)
372 return;
373
Damien Miller95def091999-11-25 00:26:21 +1100374 /* Read and buffer any available stdout data from the program. */
375 if (!fdout_eof && FD_ISSET(fdout, readset)) {
376 len = read(fdout, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000377 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
378 /* do nothing */
379 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100380 fdout_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000381 } else {
Damien Miller95def091999-11-25 00:26:21 +1100382 buffer_append(&stdout_buffer, buf, len);
383 fdout_bytes += len;
384 }
385 }
386 /* Read and buffer any available stderr data from the program. */
387 if (!fderr_eof && FD_ISSET(fderr, readset)) {
388 len = read(fderr, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000389 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
390 /* do nothing */
391 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100392 fderr_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000393 } else {
Damien Miller95def091999-11-25 00:26:21 +1100394 buffer_append(&stderr_buffer, buf, len);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000395 }
Damien Miller95def091999-11-25 00:26:21 +1100396 }
397}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000398
Damien Miller95def091999-11-25 00:26:21 +1100399/*
400 * Sends data from internal buffers to client program stdin.
401 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000402static void
Damien Miller95def091999-11-25 00:26:21 +1100403process_output(fd_set * writeset)
404{
Ben Lindstromaa630de2001-02-10 23:44:47 +0000405 struct termios tio;
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000406 u_char *data;
407 u_int dlen;
Damien Miller95def091999-11-25 00:26:21 +1100408 int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000409
Damien Miller95def091999-11-25 00:26:21 +1100410 /* Write buffered data to program stdin. */
Damien Millerefb4afe2000-04-12 18:45:05 +1000411 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000412 data = buffer_ptr(&stdin_buffer);
413 dlen = buffer_len(&stdin_buffer);
414 len = write(fdin, data, dlen);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000415 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
416 /* do nothing */
417 } else if (len <= 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000418 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100419 close(fdin);
420 else
421 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100422 fdin = -1;
423 } else {
Ben Lindstromaa630de2001-02-10 23:44:47 +0000424 /* Successful write. */
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000425 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
426 tcgetattr(fdin, &tio) == 0 &&
Damien Miller79438cc2001-02-16 12:34:57 +1100427 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
Kevin Stevesb7f036f2001-02-15 17:27:15 +0000428 /*
429 * Simulate echo to reduce the impact of
430 * traffic analysis
431 */
Ben Lindstrome229b252001-03-05 06:28:06 +0000432 packet_send_ignore(len);
Ben Lindstromaa630de2001-02-10 23:44:47 +0000433 packet_send();
434 }
435 /* Consume the data from the buffer. */
Damien Miller95def091999-11-25 00:26:21 +1100436 buffer_consume(&stdin_buffer, len);
437 /* Update the count of bytes written to the program. */
438 stdin_bytes += len;
439 }
440 }
441 /* Send any buffered packet data to the client. */
442 if (FD_ISSET(connection_out, writeset))
443 packet_write_poll();
444}
445
446/*
447 * Wait until all buffered output has been sent to the client.
448 * This is used when the program terminates.
449 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000450static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000451drain_output(void)
Damien Miller95def091999-11-25 00:26:21 +1100452{
453 /* Send any buffered stdout data to the client. */
454 if (buffer_len(&stdout_buffer) > 0) {
455 packet_start(SSH_SMSG_STDOUT_DATA);
456 packet_put_string(buffer_ptr(&stdout_buffer),
457 buffer_len(&stdout_buffer));
458 packet_send();
459 /* Update the count of sent bytes. */
460 stdout_bytes += buffer_len(&stdout_buffer);
461 }
462 /* Send any buffered stderr data to the client. */
463 if (buffer_len(&stderr_buffer) > 0) {
464 packet_start(SSH_SMSG_STDERR_DATA);
465 packet_put_string(buffer_ptr(&stderr_buffer),
466 buffer_len(&stderr_buffer));
467 packet_send();
468 /* Update the count of sent bytes. */
469 stderr_bytes += buffer_len(&stderr_buffer);
470 }
471 /* Wait until all buffered data has been written to the client. */
472 packet_write_wait();
473}
474
Ben Lindstrombba81212001-06-25 05:01:22 +0000475static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000476process_buffered_input_packets(void)
Damien Millerb38eff82000-04-01 11:09:21 +1000477{
Ben Lindstrom8ac91062001-04-04 17:57:54 +0000478 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
Damien Millerb38eff82000-04-01 11:09:21 +1000479}
480
Damien Miller95def091999-11-25 00:26:21 +1100481/*
482 * Performs the interactive session. This handles data transmission between
483 * the client and the program. Note that the notion of stdin, stdout, and
484 * stderr in this function is sort of reversed: this function writes to
485 * stdin (of the child program), and reads from stdout and stderr (of the
486 * child program).
487 */
Damien Miller4af51302000-04-16 11:18:38 +1000488void
Damien Miller166fca82000-04-20 07:42:21 +1000489server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
Damien Miller95def091999-11-25 00:26:21 +1100490{
Damien Miller5e953212001-01-30 09:14:00 +1100491 fd_set *readset = NULL, *writeset = NULL;
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000492 int max_fd = 0, nalloc = 0;
Damien Miller166fca82000-04-20 07:42:21 +1000493 int wait_status; /* Status returned by wait(). */
494 pid_t wait_pid; /* pid returned by wait(). */
Damien Miller95def091999-11-25 00:26:21 +1100495 int waiting_termination = 0; /* Have displayed waiting close message. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000496 u_int max_time_milliseconds;
497 u_int previous_stdout_buffer_bytes;
498 u_int stdout_buffer_bytes;
Damien Miller95def091999-11-25 00:26:21 +1100499 int type;
500
501 debug("Entering interactive session.");
502
503 /* Initialize the SIGCHLD kludge. */
Damien Miller95def091999-11-25 00:26:21 +1100504 child_terminated = 0;
Kevin Stevese26a1552001-07-26 17:51:49 +0000505 mysignal(SIGCHLD, sigchld_handler);
Damien Miller95def091999-11-25 00:26:21 +1100506
507 /* Initialize our global variables. */
508 fdin = fdin_arg;
509 fdout = fdout_arg;
510 fderr = fderr_arg;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000511
512 /* nonblocking IO */
513 set_nonblock(fdin);
514 set_nonblock(fdout);
Damien Miller7d6656c2000-05-20 15:22:36 +1000515 /* we don't have stderr for interactive terminal sessions, see below */
516 if (fderr != -1)
517 set_nonblock(fderr);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000518
Damien Miller225736c2001-02-19 21:51:08 +1100519 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
520 fdin_is_tty = 1;
521
Damien Miller95def091999-11-25 00:26:21 +1100522 connection_in = packet_get_connection_in();
523 connection_out = packet_get_connection_out();
524
Damien Millerf6681a32001-12-21 14:53:11 +1100525 notify_setup();
526
Damien Miller95def091999-11-25 00:26:21 +1100527 previous_stdout_buffer_bytes = 0;
528
529 /* Set approximate I/O buffer size. */
530 if (packet_is_interactive())
531 buffer_high = 4096;
532 else
533 buffer_high = 64 * 1024;
534
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000535#if 0
Damien Miller95def091999-11-25 00:26:21 +1100536 /* Initialize max_fd to the maximum of the known file descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000537 max_fd = MAX(connection_in, connection_out);
538 max_fd = MAX(max_fd, fdin);
539 max_fd = MAX(max_fd, fdout);
Damien Miller5e953212001-01-30 09:14:00 +1100540 if (fderr != -1)
541 max_fd = MAX(max_fd, fderr);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000542#endif
Damien Miller95def091999-11-25 00:26:21 +1100543
544 /* Initialize Initialize buffers. */
545 buffer_init(&stdin_buffer);
546 buffer_init(&stdout_buffer);
547 buffer_init(&stderr_buffer);
548
Damien Miller5428f641999-11-25 11:54:57 +1100549 /*
550 * If we have no separate fderr (which is the case when we have a pty
551 * - there we cannot make difference between data sent to stdout and
552 * stderr), indicate that we have seen an EOF from stderr. This way
553 * we don\'t need to check the descriptor everywhere.
554 */
Damien Miller95def091999-11-25 00:26:21 +1100555 if (fderr == -1)
556 fderr_eof = 1;
557
Damien Millerb38eff82000-04-01 11:09:21 +1000558 server_init_dispatch();
559
Damien Miller95def091999-11-25 00:26:21 +1100560 /* Main loop of the server for the interactive session mode. */
561 for (;;) {
Damien Miller95def091999-11-25 00:26:21 +1100562
563 /* Process buffered packets from the client. */
564 process_buffered_input_packets();
565
Damien Miller5428f641999-11-25 11:54:57 +1100566 /*
567 * If we have received eof, and there is no more pending
568 * input data, cause a real eof by closing fdin.
569 */
Damien Miller95def091999-11-25 00:26:21 +1100570 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000571 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100572 close(fdin);
573 else
574 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100575 fdin = -1;
576 }
Damien Miller5428f641999-11-25 11:54:57 +1100577 /* Make packets from buffered stderr data to send to the client. */
Damien Miller95def091999-11-25 00:26:21 +1100578 make_packets_from_stderr_data();
579
Damien Miller5428f641999-11-25 11:54:57 +1100580 /*
581 * Make packets from buffered stdout data to send to the
582 * client. If there is very little to send, this arranges to
583 * not send them now, but to wait a short while to see if we
584 * are getting more data. This is necessary, as some systems
585 * wake up readers from a pty after each separate character.
586 */
Damien Miller95def091999-11-25 00:26:21 +1100587 max_time_milliseconds = 0;
588 stdout_buffer_bytes = buffer_len(&stdout_buffer);
589 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
590 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
591 /* try again after a while */
592 max_time_milliseconds = 10;
593 } else {
594 /* Send it now. */
595 make_packets_from_stdout_data();
596 }
597 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
598
599 /* Send channel data to the client. */
600 if (packet_not_very_much_data_to_write())
601 channel_output_poll();
602
Damien Miller5428f641999-11-25 11:54:57 +1100603 /*
604 * Bail out of the loop if the program has closed its output
605 * descriptors, and we have no more data to send to the
606 * client, and there is no pending buffered data.
607 */
Damien Miller43dc8da2000-11-29 15:55:17 +1100608 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
609 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
Damien Miller95def091999-11-25 00:26:21 +1100610 if (!channel_still_open())
Damien Millerb38eff82000-04-01 11:09:21 +1000611 break;
Damien Miller95def091999-11-25 00:26:21 +1100612 if (!waiting_termination) {
613 const char *s = "Waiting for forwarded connections to terminate...\r\n";
614 char *cp;
615 waiting_termination = 1;
616 buffer_append(&stderr_buffer, s, strlen(s));
617
618 /* Display list of open channels. */
619 cp = channel_open_message();
620 buffer_append(&stderr_buffer, cp, strlen(cp));
621 xfree(cp);
622 }
623 }
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000624 max_fd = MAX(connection_in, connection_out);
625 max_fd = MAX(max_fd, fdin);
626 max_fd = MAX(max_fd, fdout);
627 max_fd = MAX(max_fd, fderr);
Damien Millerf6681a32001-12-21 14:53:11 +1100628 max_fd = MAX(max_fd, notify_pipe[0]);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000629
Damien Miller95def091999-11-25 00:26:21 +1100630 /* Sleep in select() until we can do something. */
Damien Miller5e953212001-01-30 09:14:00 +1100631 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000632 &nalloc, max_time_milliseconds);
Damien Miller95def091999-11-25 00:26:21 +1100633
634 /* Process any channel events. */
Damien Miller5e953212001-01-30 09:14:00 +1100635 channel_after_select(readset, writeset);
Damien Miller95def091999-11-25 00:26:21 +1100636
637 /* Process input from the client and from program stdout/stderr. */
Damien Miller5e953212001-01-30 09:14:00 +1100638 process_input(readset);
Damien Miller95def091999-11-25 00:26:21 +1100639
640 /* Process output to the client and to program stdin. */
Damien Miller5e953212001-01-30 09:14:00 +1100641 process_output(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100642 }
Damien Miller5e953212001-01-30 09:14:00 +1100643 if (readset)
644 xfree(readset);
645 if (writeset)
646 xfree(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100647
Damien Miller95def091999-11-25 00:26:21 +1100648 /* Cleanup and termination code. */
649
650 /* Wait until all output has been sent to the client. */
651 drain_output();
652
653 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100654 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
Damien Miller95def091999-11-25 00:26:21 +1100655
656 /* Free and clear the buffers. */
657 buffer_free(&stdin_buffer);
658 buffer_free(&stdout_buffer);
659 buffer_free(&stderr_buffer);
660
661 /* Close the file descriptors. */
662 if (fdout != -1)
663 close(fdout);
664 fdout = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000665 fdout_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100666 if (fderr != -1)
667 close(fderr);
668 fderr = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000669 fderr_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100670 if (fdin != -1)
671 close(fdin);
672 fdin = -1;
673
Ben Lindstrom601e4362001-06-21 03:19:23 +0000674 channel_free_all();
Damien Miller95def091999-11-25 00:26:21 +1100675
Damien Miller95def091999-11-25 00:26:21 +1100676 /* We no longer want our SIGCHLD handler to be called. */
Kevin Stevese26a1552001-07-26 17:51:49 +0000677 mysignal(SIGCHLD, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100678
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000679 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
680 if (errno != EINTR)
681 packet_disconnect("wait: %.100s", strerror(errno));
682 if (wait_pid != pid)
Ben Lindstromce0f6342002-06-11 16:42:49 +0000683 error("Strange, wait returned pid %ld, expected %ld",
684 (long)wait_pid, (long)pid);
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000685
Damien Miller95def091999-11-25 00:26:21 +1100686 /* Check if it exited normally. */
687 if (WIFEXITED(wait_status)) {
688 /* Yes, normal exit. Get exit status and send it to the client. */
689 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
690 packet_start(SSH_SMSG_EXITSTATUS);
691 packet_put_int(WEXITSTATUS(wait_status));
692 packet_send();
693 packet_write_wait();
694
Damien Miller5428f641999-11-25 11:54:57 +1100695 /*
696 * Wait for exit confirmation. Note that there might be
697 * other packets coming before it; however, the program has
698 * already died so we just ignore them. The client is
699 * supposed to respond with the confirmation when it receives
700 * the exit status.
701 */
Damien Miller95def091999-11-25 00:26:21 +1100702 do {
Damien Millerdff50992002-01-22 23:16:32 +1100703 type = packet_read();
Damien Miller95def091999-11-25 00:26:21 +1100704 }
705 while (type != SSH_CMSG_EXIT_CONFIRMATION);
706
707 debug("Received exit confirmation.");
708 return;
709 }
710 /* Check if the program terminated due to a signal. */
711 if (WIFSIGNALED(wait_status))
712 packet_disconnect("Command terminated on signal %d.",
713 WTERMSIG(wait_status));
714
715 /* Some weird exit cause. Just exit. */
716 packet_disconnect("wait returned status %04x.", wait_status);
717 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000718}
Damien Millerb38eff82000-04-01 11:09:21 +1000719
Damien Miller3ec27592001-10-12 11:35:04 +1000720static void
721collect_children(void)
722{
723 pid_t pid;
724 sigset_t oset, nset;
725 int status;
726
727 /* block SIGCHLD while we check for dead children */
728 sigemptyset(&nset);
729 sigaddset(&nset, SIGCHLD);
730 sigprocmask(SIG_BLOCK, &nset, &oset);
731 if (child_terminated) {
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000732 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
733 (pid < 0 && errno == EINTR))
734 if (pid > 0)
735 session_close_by_pid(pid, status);
Damien Miller3ec27592001-10-12 11:35:04 +1000736 child_terminated = 0;
737 }
738 sigprocmask(SIG_SETMASK, &oset, NULL);
739}
740
Damien Miller4af51302000-04-16 11:18:38 +1000741void
Ben Lindstrombddd5512001-07-04 04:53:53 +0000742server_loop2(Authctxt *authctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000743{
Damien Miller5e953212001-01-30 09:14:00 +1100744 fd_set *readset = NULL, *writeset = NULL;
Damien Miller3ec27592001-10-12 11:35:04 +1000745 int rekeying = 0, max_fd, nalloc = 0;
Damien Millerefb4afe2000-04-12 18:45:05 +1000746
747 debug("Entering interactive session for SSH2.");
748
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000749 mysignal(SIGCHLD, sigchld_handler);
Damien Millerefb4afe2000-04-12 18:45:05 +1000750 child_terminated = 0;
751 connection_in = packet_get_connection_in();
752 connection_out = packet_get_connection_out();
Damien Miller5e953212001-01-30 09:14:00 +1100753
Damien Millerf6681a32001-12-21 14:53:11 +1100754 notify_setup();
755
Damien Miller5e953212001-01-30 09:14:00 +1100756 max_fd = MAX(connection_in, connection_out);
Damien Millerf6681a32001-12-21 14:53:11 +1100757 max_fd = MAX(max_fd, notify_pipe[0]);
758
Ben Lindstrombddd5512001-07-04 04:53:53 +0000759 xxx_authctxt = authctxt;
Damien Miller5e953212001-01-30 09:14:00 +1100760
Damien Millerefb4afe2000-04-12 18:45:05 +1000761 server_init_dispatch();
762
763 for (;;) {
764 process_buffered_input_packets();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000765
Ben Lindstroma3700052001-04-05 23:26:32 +0000766 rekeying = (xxx_kex != NULL && !xxx_kex->done);
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000767
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000768 if (!rekeying && packet_not_very_much_data_to_write())
Damien Millerefb4afe2000-04-12 18:45:05 +1000769 channel_output_poll();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000770 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000771 &nalloc, 0);
Damien Miller52b77be2001-10-10 15:14:37 +1000772
Damien Miller3ec27592001-10-12 11:35:04 +1000773 collect_children();
Damien Millera5539d22003-04-09 20:50:06 +1000774 if (!rekeying) {
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000775 channel_after_select(readset, writeset);
Damien Millera5539d22003-04-09 20:50:06 +1000776 if (packet_need_rekeying()) {
777 debug("need rekeying");
778 xxx_kex->done = 0;
779 kex_send_kexinit(xxx_kex);
780 }
781 }
Damien Miller5e953212001-01-30 09:14:00 +1100782 process_input(readset);
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000783 if (connection_closed)
784 break;
Damien Miller5e953212001-01-30 09:14:00 +1100785 process_output(writeset);
Damien Millerefb4afe2000-04-12 18:45:05 +1000786 }
Damien Miller3ec27592001-10-12 11:35:04 +1000787 collect_children();
788
Damien Miller5e953212001-01-30 09:14:00 +1100789 if (readset)
790 xfree(readset);
791 if (writeset)
792 xfree(writeset);
793
Damien Miller52b77be2001-10-10 15:14:37 +1000794 /* free all channels, no more reads and writes */
795 channel_free_all();
Ben Lindstrom4983d5e2001-07-04 05:17:40 +0000796
Damien Miller3ec27592001-10-12 11:35:04 +1000797 /* free remaining sessions, e.g. remove wtmp entries */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000798 session_destroy_all(NULL);
Damien Millerefb4afe2000-04-12 18:45:05 +1000799}
800
Ben Lindstrombba81212001-06-25 05:01:22 +0000801static void
Damien Miller630d6f42002-01-22 23:17:30 +1100802server_input_channel_failure(int type, u_int32_t seq, void *ctxt)
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000803{
804 debug("Got CHANNEL_FAILURE for keepalive");
Damien Miller9f0f5c62001-12-21 14:45:46 +1100805 /*
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000806 * reset timeout, since we got a sane answer from the client.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000807 * even if this was generated by something other than
808 * the bogus CHANNEL_REQUEST we send for keepalives.
809 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100810 client_alive_timeouts = 0;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000811}
812
813
Ben Lindstrombba81212001-06-25 05:01:22 +0000814static void
Damien Miller630d6f42002-01-22 23:17:30 +1100815server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000816{
817 char *data;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000818 u_int data_len;
Damien Millerb38eff82000-04-01 11:09:21 +1000819
820 /* Stdin data from the client. Append it to the buffer. */
821 /* Ignore any data if the client has closed stdin. */
822 if (fdin == -1)
823 return;
824 data = packet_get_string(&data_len);
Damien Miller48b03fc2002-01-22 23:11:40 +1100825 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000826 buffer_append(&stdin_buffer, data, data_len);
827 memset(data, 0, data_len);
828 xfree(data);
829}
830
Ben Lindstrombba81212001-06-25 05:01:22 +0000831static void
Damien Miller630d6f42002-01-22 23:17:30 +1100832server_input_eof(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000833{
834 /*
835 * Eof from the client. The stdin descriptor to the
836 * program will be closed when all buffered data has
837 * drained.
838 */
839 debug("EOF received for stdin.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100840 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000841 stdin_eof = 1;
842}
843
Ben Lindstrombba81212001-06-25 05:01:22 +0000844static void
Damien Miller630d6f42002-01-22 23:17:30 +1100845server_input_window_size(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000846{
847 int row = packet_get_int();
848 int col = packet_get_int();
849 int xpixel = packet_get_int();
850 int ypixel = packet_get_int();
851
852 debug("Window change received.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100853 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000854 if (fdin != -1)
855 pty_change_window_size(fdin, row, col, xpixel, ypixel);
856}
857
Ben Lindstrombba81212001-06-25 05:01:22 +0000858static Channel *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100859server_request_direct_tcpip(char *ctype)
Damien Millerefb4afe2000-04-12 18:45:05 +1000860{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000861 Channel *c;
862 int sock;
Damien Miller4af51302000-04-16 11:18:38 +1000863 char *target, *originator;
864 int target_port, originator_port;
Damien Millerefb4afe2000-04-12 18:45:05 +1000865
Damien Miller4af51302000-04-16 11:18:38 +1000866 target = packet_get_string(NULL);
867 target_port = packet_get_int();
Damien Millerefb4afe2000-04-12 18:45:05 +1000868 originator = packet_get_string(NULL);
869 originator_port = packet_get_int();
Damien Miller48b03fc2002-01-22 23:11:40 +1100870 packet_check_eom();
Damien Millerb1715dc2000-05-30 13:44:51 +1000871
Damien Miller0bc1bd82000-11-13 22:57:25 +1100872 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
Damien Millerb1715dc2000-05-30 13:44:51 +1000873 originator, originator_port, target, target_port);
Damien Millerf6d9e222000-06-18 14:50:44 +1000874
Damien Millerefb4afe2000-04-12 18:45:05 +1000875 /* XXX check permission */
Damien Miller4af51302000-04-16 11:18:38 +1000876 sock = channel_connect_to(target, target_port);
877 xfree(target);
Damien Millerefb4afe2000-04-12 18:45:05 +1000878 xfree(originator);
879 if (sock < 0)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100880 return NULL;
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000881 c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
Damien Millere4340be2000-09-16 13:29:08 +1100882 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000883 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000884 return c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100885}
886
Ben Lindstrombba81212001-06-25 05:01:22 +0000887static Channel *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100888server_request_session(char *ctype)
889{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000890 Channel *c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100891
892 debug("input_session_request");
Damien Miller48b03fc2002-01-22 23:11:40 +1100893 packet_check_eom();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100894 /*
895 * A server session has no fd to read or write until a
896 * CHANNEL_REQUEST for a shell is made, so we set the type to
897 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
898 * CHANNEL_REQUEST messages is registered.
899 */
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000900 c = channel_new(ctype, SSH_CHANNEL_LARVAL,
901 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000902 0, "server-session", 1);
Ben Lindstrombddd5512001-07-04 04:53:53 +0000903 if (session_open(xxx_authctxt, c->self) != 1) {
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000904 debug("session open failed, free channel %d", c->self);
905 channel_free(c);
906 return NULL;
907 }
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000908 channel_register_cleanup(c->self, session_close_by_channel);
909 return c;
Damien Millerefb4afe2000-04-12 18:45:05 +1000910}
911
Ben Lindstrombba81212001-06-25 05:01:22 +0000912static void
Damien Miller630d6f42002-01-22 23:17:30 +1100913server_input_channel_open(int type, u_int32_t seq, void *ctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000914{
915 Channel *c = NULL;
916 char *ctype;
Damien Millerefb4afe2000-04-12 18:45:05 +1000917 int rchan;
Ben Lindstrom4fed2be2002-06-25 23:17:36 +0000918 u_int rmaxpack, rwindow, len;
Damien Millerefb4afe2000-04-12 18:45:05 +1000919
920 ctype = packet_get_string(&len);
921 rchan = packet_get_int();
922 rwindow = packet_get_int();
923 rmaxpack = packet_get_int();
924
Damien Miller62cee002000-09-23 17:15:56 +1100925 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
Damien Millerefb4afe2000-04-12 18:45:05 +1000926 ctype, rchan, rwindow, rmaxpack);
927
928 if (strcmp(ctype, "session") == 0) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100929 c = server_request_session(ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000930 } else if (strcmp(ctype, "direct-tcpip") == 0) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100931 c = server_request_direct_tcpip(ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000932 }
933 if (c != NULL) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100934 debug("server_input_channel_open: confirm %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000935 c->remote_id = rchan;
936 c->remote_window = rwindow;
937 c->remote_maxpacket = rmaxpack;
Ben Lindstrom69128662001-05-08 20:07:39 +0000938 if (c->type != SSH_CHANNEL_CONNECTING) {
939 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
940 packet_put_int(c->remote_id);
941 packet_put_int(c->self);
942 packet_put_int(c->local_window);
943 packet_put_int(c->local_maxpacket);
944 packet_send();
945 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000946 } else {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100947 debug("server_input_channel_open: failure %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000948 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
949 packet_put_int(rchan);
950 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
Ben Lindstromf3436742001-04-29 19:52:00 +0000951 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
Ben Lindstrom69128662001-05-08 20:07:39 +0000952 packet_put_cstring("open failed");
Ben Lindstromf3436742001-04-29 19:52:00 +0000953 packet_put_cstring("");
954 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000955 packet_send();
956 }
957 xfree(ctype);
958}
959
Ben Lindstrombba81212001-06-25 05:01:22 +0000960static void
Damien Miller630d6f42002-01-22 23:17:30 +1100961server_input_global_request(int type, u_int32_t seq, void *ctxt)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100962{
963 char *rtype;
964 int want_reply;
965 int success = 0;
966
967 rtype = packet_get_string(NULL);
968 want_reply = packet_get_char();
969 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
Kevin Stevesef4eea92001-02-05 12:42:17 +0000970
Ben Lindstrom7bb8b492001-03-17 00:47:54 +0000971 /* -R style forwarding */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100972 if (strcmp(rtype, "tcpip-forward") == 0) {
973 struct passwd *pw;
974 char *listen_address;
975 u_short listen_port;
976
977 pw = auth_get_user();
978 if (pw == NULL)
979 fatal("server_input_global_request: no user");
Damien Miller9fc7c692003-06-04 22:50:54 +1000980 listen_address = packet_get_string(NULL);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100981 listen_port = (u_short)packet_get_int();
982 debug("server_input_global_request: tcpip-forward listen %s port %d",
983 listen_address, listen_port);
984
985 /* check permissions */
986 if (!options.allow_tcp_forwarding ||
Ben Lindstrom99a4e142002-07-09 14:06:40 +0000987 no_port_forwarding_flag
988#ifndef NO_IPPORT_RESERVED_CONCEPT
989 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
990#endif
991 ) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100992 success = 0;
993 packet_send_debug("Server has disabled port forwarding.");
994 } else {
995 /* Start listening on the port */
Damien Millerb16461c2002-01-22 23:29:22 +1100996 success = channel_setup_remote_fwd_listener(
997 listen_address, listen_port, options.gateway_ports);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100998 }
999 xfree(listen_address);
1000 }
1001 if (want_reply) {
1002 packet_start(success ?
1003 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1004 packet_send();
1005 packet_write_wait();
1006 }
1007 xfree(rtype);
1008}
Damien Millerc7ef63d2002-02-05 12:21:42 +11001009static void
1010server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1011{
1012 Channel *c;
1013 int id, reply, success = 0;
1014 char *rtype;
1015
1016 id = packet_get_int();
1017 rtype = packet_get_string(NULL);
1018 reply = packet_get_char();
1019
1020 debug("server_input_channel_req: channel %d request %s reply %d",
1021 id, rtype, reply);
1022
1023 if ((c = channel_lookup(id)) == NULL)
1024 packet_disconnect("server_input_channel_req: "
1025 "unknown channel %d", id);
1026 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1027 success = session_input_channel_req(c, rtype);
1028 if (reply) {
1029 packet_start(success ?
1030 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1031 packet_put_int(c->remote_id);
1032 packet_send();
1033 }
1034 xfree(rtype);
1035}
Damien Miller0bc1bd82000-11-13 22:57:25 +11001036
Ben Lindstrombba81212001-06-25 05:01:22 +00001037static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001038server_init_dispatch_20(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10001039{
1040 debug("server_init_dispatch_20");
1041 dispatch_init(&dispatch_protocol_error);
1042 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1043 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1044 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1045 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1046 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1047 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1048 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
Damien Millerc7ef63d2002-02-05 12:21:42 +11001049 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
Damien Millerefb4afe2000-04-12 18:45:05 +10001050 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001051 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
Ben Lindstrom5744dc42001-04-13 23:28:01 +00001052 /* client_alive */
1053 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure);
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001054 /* rekeying */
1055 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
Damien Millerefb4afe2000-04-12 18:45:05 +10001056}
Ben Lindstrombba81212001-06-25 05:01:22 +00001057static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001058server_init_dispatch_13(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001059{
1060 debug("server_init_dispatch_13");
1061 dispatch_init(NULL);
1062 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1063 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1064 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1065 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1066 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1067 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1068 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1069 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1070 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1071}
Ben Lindstrombba81212001-06-25 05:01:22 +00001072static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001073server_init_dispatch_15(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001074{
1075 server_init_dispatch_13();
1076 debug("server_init_dispatch_15");
1077 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1078 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1079}
Ben Lindstrombba81212001-06-25 05:01:22 +00001080static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001081server_init_dispatch(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001082{
Damien Millerefb4afe2000-04-12 18:45:05 +10001083 if (compat20)
1084 server_init_dispatch_20();
1085 else if (compat13)
Damien Millerb38eff82000-04-01 11:09:21 +10001086 server_init_dispatch_13();
1087 else
1088 server_init_dispatch_15();
1089}