blob: bc7cd656afd8e9bac1e44684265685d2d2de1a40 [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"
Damien Millerb5820f42003-12-17 16:27:32 +110038RCSID("$OpenBSD: serverloop.c,v 1.114 2003/12/09 15:28:43 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;
Darren Tucker3e33cec2003-10-02 16:12:36 +100063extern Authctxt *the_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 Millerb5820f42003-12-17 16:27:32 +1100215 int channel_id;
Damien Miller056cf732002-01-22 23:21:39 +1100216
Damien Miller8c3902a2001-10-10 15:01:40 +1000217 /* timeout, check to see how many we have had */
218 if (++client_alive_timeouts > options.client_alive_count_max)
219 packet_disconnect("Timeout, your session not responding.");
220
Damien Miller8c3902a2001-10-10 15:01:40 +1000221 /*
Damien Millerb5820f42003-12-17 16:27:32 +1100222 * send a bogus global/channel request with "wantreply",
Damien Miller8c3902a2001-10-10 15:01:40 +1000223 * we should get back a failure
224 */
Damien Millerb5820f42003-12-17 16:27:32 +1100225 if ((channel_id = channel_find_open()) == -1) {
226 packet_start(SSH2_MSG_GLOBAL_REQUEST);
227 packet_put_cstring("keepalive@openssh.com");
228 packet_put_char(1); /* boolean: want reply */
229 } else {
230 channel_request_start(channel_id, "keepalive@openssh.com", 1);
231 }
Damien Miller8c3902a2001-10-10 15:01:40 +1000232 packet_send();
233}
234
Damien Miller95def091999-11-25 00:26:21 +1100235/*
236 * Sleep in select() until we can do something. This will initialize the
237 * select masks. Upon return, the masks will indicate which descriptors
238 * have data or can accept data. Optionally, a maximum time can be specified
239 * for the duration of the wait (0 = infinite).
240 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000241static void
Damien Miller5e953212001-01-30 09:14:00 +1100242wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000243 int *nallocp, u_int max_time_milliseconds)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000244{
Damien Miller95def091999-11-25 00:26:21 +1100245 struct timeval tv, *tvp;
246 int ret;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000247 int client_alive_scheduled = 0;
248
249 /*
Damien Miller9f0f5c62001-12-21 14:45:46 +1100250 * if using client_alive, set the max timeout accordingly,
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000251 * and indicate that this particular timeout was for client
252 * alive by setting the client_alive_scheduled flag.
253 *
254 * this could be randomized somewhat to make traffic
Damien Miller9f0f5c62001-12-21 14:45:46 +1100255 * analysis more difficult, but we're not doing it yet.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000256 */
Ben Lindstrom36857f62001-07-18 15:48:57 +0000257 if (compat20 &&
258 max_time_milliseconds == 0 && options.client_alive_interval) {
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000259 client_alive_scheduled = 1;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000260 max_time_milliseconds = options.client_alive_interval * 1000;
Ben Lindstrom36857f62001-07-18 15:48:57 +0000261 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000262
Damien Miller5e953212001-01-30 09:14:00 +1100263 /* Allocate and update select() masks for channel descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000264 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000265
Damien Millerefb4afe2000-04-12 18:45:05 +1000266 if (compat20) {
Damien Milleraf5f2e62001-10-10 15:01:16 +1000267#if 0
Damien Millere247cc42000-05-07 12:03:14 +1000268 /* wrong: bad condition XXX */
Damien Millerefb4afe2000-04-12 18:45:05 +1000269 if (channel_not_very_much_buffered_data())
Damien Milleraf5f2e62001-10-10 15:01:16 +1000270#endif
271 FD_SET(connection_in, *readsetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000272 } else {
Damien Millerb1715dc2000-05-30 13:44:51 +1000273 /*
274 * Read packets from the client unless we have too much
275 * buffered stdin or channel data.
276 */
277 if (buffer_len(&stdin_buffer) < buffer_high &&
Damien Millerefb4afe2000-04-12 18:45:05 +1000278 channel_not_very_much_buffered_data())
Damien Miller5e953212001-01-30 09:14:00 +1100279 FD_SET(connection_in, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000280 /*
281 * If there is not too much data already buffered going to
282 * the client, try to get some more data from the program.
283 */
284 if (packet_not_very_much_data_to_write()) {
285 if (!fdout_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100286 FD_SET(fdout, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000287 if (!fderr_eof)
Damien Miller5e953212001-01-30 09:14:00 +1100288 FD_SET(fderr, *readsetp);
Damien Millerb1715dc2000-05-30 13:44:51 +1000289 }
290 /*
291 * If we have buffered data, try to write some of that data
292 * to the program.
293 */
294 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
Damien Miller5e953212001-01-30 09:14:00 +1100295 FD_SET(fdin, *writesetp);
Damien Millerefb4afe2000-04-12 18:45:05 +1000296 }
Damien Millerf6681a32001-12-21 14:53:11 +1100297 notify_prepare(*readsetp);
Damien Miller95def091999-11-25 00:26:21 +1100298
Damien Miller5428f641999-11-25 11:54:57 +1100299 /*
300 * If we have buffered packet data going to the client, mark that
301 * descriptor.
302 */
Damien Miller95def091999-11-25 00:26:21 +1100303 if (packet_have_data_to_write())
Damien Miller5e953212001-01-30 09:14:00 +1100304 FD_SET(connection_out, *writesetp);
Damien Miller95def091999-11-25 00:26:21 +1100305
Damien Miller5428f641999-11-25 11:54:57 +1100306 /*
307 * If child has terminated and there is enough buffer space to read
308 * from it, then read as much as is available and exit.
309 */
Damien Miller95def091999-11-25 00:26:21 +1100310 if (child_terminated && packet_not_very_much_data_to_write())
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000311 if (max_time_milliseconds == 0 || client_alive_scheduled)
Damien Miller95def091999-11-25 00:26:21 +1100312 max_time_milliseconds = 100;
313
314 if (max_time_milliseconds == 0)
315 tvp = NULL;
316 else {
317 tv.tv_sec = max_time_milliseconds / 1000;
318 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
319 tvp = &tv;
320 }
321
322 /* Wait for something to happen, or the timeout to expire. */
Damien Miller5e953212001-01-30 09:14:00 +1100323 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
Damien Miller95def091999-11-25 00:26:21 +1100324
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000325 if (ret == -1) {
Damien Miller79faeff2001-11-12 11:06:32 +1100326 memset(*readsetp, 0, *nallocp);
327 memset(*writesetp, 0, *nallocp);
Damien Miller95def091999-11-25 00:26:21 +1100328 if (errno != EINTR)
329 error("select: %.100s", strerror(errno));
Damien Miller3ec27592001-10-12 11:35:04 +1000330 } else if (ret == 0 && client_alive_scheduled)
Damien Miller8c3902a2001-10-10 15:01:40 +1000331 client_alive_check();
Damien Millerf6681a32001-12-21 14:53:11 +1100332
333 notify_done(*readsetp);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000334}
335
Damien Miller95def091999-11-25 00:26:21 +1100336/*
337 * Processes input from the client and the program. Input data is stored
338 * in buffers and processed later.
339 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000340static void
Damien Miller95def091999-11-25 00:26:21 +1100341process_input(fd_set * readset)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000342{
Damien Miller95def091999-11-25 00:26:21 +1100343 int len;
344 char buf[16384];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000345
Damien Miller95def091999-11-25 00:26:21 +1100346 /* Read and buffer any input data from the client. */
347 if (FD_ISSET(connection_in, readset)) {
348 len = read(connection_in, buf, sizeof(buf));
349 if (len == 0) {
Damien Miller16aed052002-09-22 01:26:27 +1000350 verbose("Connection closed by %.100s",
351 get_remote_ipaddr());
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000352 connection_closed = 1;
353 if (compat20)
354 return;
Darren Tucker3e33cec2003-10-02 16:12:36 +1000355 cleanup_exit(255);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000356 } else if (len < 0) {
357 if (errno != EINTR && errno != EAGAIN) {
Damien Miller16aed052002-09-22 01:26:27 +1000358 verbose("Read error from remote host "
359 "%.100s: %.100s",
360 get_remote_ipaddr(), strerror(errno));
Darren Tucker3e33cec2003-10-02 16:12:36 +1000361 cleanup_exit(255);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000362 }
363 } else {
364 /* Buffer any received data. */
365 packet_process_incoming(buf, len);
Damien Miller95def091999-11-25 00:26:21 +1100366 }
Damien Miller95def091999-11-25 00:26:21 +1100367 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000368 if (compat20)
369 return;
370
Damien Miller95def091999-11-25 00:26:21 +1100371 /* Read and buffer any available stdout data from the program. */
372 if (!fdout_eof && FD_ISSET(fdout, readset)) {
373 len = read(fdout, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000374 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
375 /* do nothing */
376 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100377 fdout_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000378 } else {
Damien Miller95def091999-11-25 00:26:21 +1100379 buffer_append(&stdout_buffer, buf, len);
380 fdout_bytes += len;
381 }
382 }
383 /* Read and buffer any available stderr data from the program. */
384 if (!fderr_eof && FD_ISSET(fderr, readset)) {
385 len = read(fderr, buf, sizeof(buf));
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000386 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
387 /* do nothing */
388 } else if (len <= 0) {
Damien Miller95def091999-11-25 00:26:21 +1100389 fderr_eof = 1;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000390 } else {
Damien Miller95def091999-11-25 00:26:21 +1100391 buffer_append(&stderr_buffer, buf, len);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000392 }
Damien Miller95def091999-11-25 00:26:21 +1100393 }
394}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000395
Damien Miller95def091999-11-25 00:26:21 +1100396/*
397 * Sends data from internal buffers to client program stdin.
398 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000399static void
Damien Miller95def091999-11-25 00:26:21 +1100400process_output(fd_set * writeset)
401{
Ben Lindstromaa630de2001-02-10 23:44:47 +0000402 struct termios tio;
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000403 u_char *data;
404 u_int dlen;
Damien Miller95def091999-11-25 00:26:21 +1100405 int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000406
Damien Miller95def091999-11-25 00:26:21 +1100407 /* Write buffered data to program stdin. */
Damien Millerefb4afe2000-04-12 18:45:05 +1000408 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000409 data = buffer_ptr(&stdin_buffer);
410 dlen = buffer_len(&stdin_buffer);
411 len = write(fdin, data, dlen);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000412 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
413 /* do nothing */
414 } else if (len <= 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000415 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100416 close(fdin);
417 else
418 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100419 fdin = -1;
420 } else {
Ben Lindstromaa630de2001-02-10 23:44:47 +0000421 /* Successful write. */
Ben Lindstrom6d218f42001-09-18 05:53:12 +0000422 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
423 tcgetattr(fdin, &tio) == 0 &&
Damien Miller79438cc2001-02-16 12:34:57 +1100424 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
Kevin Stevesb7f036f2001-02-15 17:27:15 +0000425 /*
426 * Simulate echo to reduce the impact of
427 * traffic analysis
428 */
Ben Lindstrome229b252001-03-05 06:28:06 +0000429 packet_send_ignore(len);
Ben Lindstromaa630de2001-02-10 23:44:47 +0000430 packet_send();
431 }
432 /* Consume the data from the buffer. */
Damien Miller95def091999-11-25 00:26:21 +1100433 buffer_consume(&stdin_buffer, len);
434 /* Update the count of bytes written to the program. */
435 stdin_bytes += len;
436 }
437 }
438 /* Send any buffered packet data to the client. */
439 if (FD_ISSET(connection_out, writeset))
440 packet_write_poll();
441}
442
443/*
444 * Wait until all buffered output has been sent to the client.
445 * This is used when the program terminates.
446 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000447static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000448drain_output(void)
Damien Miller95def091999-11-25 00:26:21 +1100449{
450 /* Send any buffered stdout data to the client. */
451 if (buffer_len(&stdout_buffer) > 0) {
452 packet_start(SSH_SMSG_STDOUT_DATA);
453 packet_put_string(buffer_ptr(&stdout_buffer),
454 buffer_len(&stdout_buffer));
455 packet_send();
456 /* Update the count of sent bytes. */
457 stdout_bytes += buffer_len(&stdout_buffer);
458 }
459 /* Send any buffered stderr data to the client. */
460 if (buffer_len(&stderr_buffer) > 0) {
461 packet_start(SSH_SMSG_STDERR_DATA);
462 packet_put_string(buffer_ptr(&stderr_buffer),
463 buffer_len(&stderr_buffer));
464 packet_send();
465 /* Update the count of sent bytes. */
466 stderr_bytes += buffer_len(&stderr_buffer);
467 }
468 /* Wait until all buffered data has been written to the client. */
469 packet_write_wait();
470}
471
Ben Lindstrombba81212001-06-25 05:01:22 +0000472static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000473process_buffered_input_packets(void)
Damien Millerb38eff82000-04-01 11:09:21 +1000474{
Ben Lindstrom8ac91062001-04-04 17:57:54 +0000475 dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
Damien Millerb38eff82000-04-01 11:09:21 +1000476}
477
Damien Miller95def091999-11-25 00:26:21 +1100478/*
479 * Performs the interactive session. This handles data transmission between
480 * the client and the program. Note that the notion of stdin, stdout, and
481 * stderr in this function is sort of reversed: this function writes to
482 * stdin (of the child program), and reads from stdout and stderr (of the
483 * child program).
484 */
Damien Miller4af51302000-04-16 11:18:38 +1000485void
Damien Miller166fca82000-04-20 07:42:21 +1000486server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
Damien Miller95def091999-11-25 00:26:21 +1100487{
Damien Miller5e953212001-01-30 09:14:00 +1100488 fd_set *readset = NULL, *writeset = NULL;
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000489 int max_fd = 0, nalloc = 0;
Damien Miller166fca82000-04-20 07:42:21 +1000490 int wait_status; /* Status returned by wait(). */
491 pid_t wait_pid; /* pid returned by wait(). */
Damien Miller95def091999-11-25 00:26:21 +1100492 int waiting_termination = 0; /* Have displayed waiting close message. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000493 u_int max_time_milliseconds;
494 u_int previous_stdout_buffer_bytes;
495 u_int stdout_buffer_bytes;
Damien Miller95def091999-11-25 00:26:21 +1100496 int type;
497
498 debug("Entering interactive session.");
499
500 /* Initialize the SIGCHLD kludge. */
Damien Miller95def091999-11-25 00:26:21 +1100501 child_terminated = 0;
Kevin Stevese26a1552001-07-26 17:51:49 +0000502 mysignal(SIGCHLD, sigchld_handler);
Damien Miller95def091999-11-25 00:26:21 +1100503
504 /* Initialize our global variables. */
505 fdin = fdin_arg;
506 fdout = fdout_arg;
507 fderr = fderr_arg;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000508
509 /* nonblocking IO */
510 set_nonblock(fdin);
511 set_nonblock(fdout);
Damien Miller7d6656c2000-05-20 15:22:36 +1000512 /* we don't have stderr for interactive terminal sessions, see below */
513 if (fderr != -1)
514 set_nonblock(fderr);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000515
Damien Miller225736c2001-02-19 21:51:08 +1100516 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
517 fdin_is_tty = 1;
518
Damien Miller95def091999-11-25 00:26:21 +1100519 connection_in = packet_get_connection_in();
520 connection_out = packet_get_connection_out();
521
Damien Millerf6681a32001-12-21 14:53:11 +1100522 notify_setup();
523
Damien Miller95def091999-11-25 00:26:21 +1100524 previous_stdout_buffer_bytes = 0;
525
526 /* Set approximate I/O buffer size. */
527 if (packet_is_interactive())
528 buffer_high = 4096;
529 else
530 buffer_high = 64 * 1024;
531
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000532#if 0
Damien Miller95def091999-11-25 00:26:21 +1100533 /* Initialize max_fd to the maximum of the known file descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000534 max_fd = MAX(connection_in, connection_out);
535 max_fd = MAX(max_fd, fdin);
536 max_fd = MAX(max_fd, fdout);
Damien Miller5e953212001-01-30 09:14:00 +1100537 if (fderr != -1)
538 max_fd = MAX(max_fd, fderr);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000539#endif
Damien Miller95def091999-11-25 00:26:21 +1100540
541 /* Initialize Initialize buffers. */
542 buffer_init(&stdin_buffer);
543 buffer_init(&stdout_buffer);
544 buffer_init(&stderr_buffer);
545
Damien Miller5428f641999-11-25 11:54:57 +1100546 /*
547 * If we have no separate fderr (which is the case when we have a pty
548 * - there we cannot make difference between data sent to stdout and
549 * stderr), indicate that we have seen an EOF from stderr. This way
550 * we don\'t need to check the descriptor everywhere.
551 */
Damien Miller95def091999-11-25 00:26:21 +1100552 if (fderr == -1)
553 fderr_eof = 1;
554
Damien Millerb38eff82000-04-01 11:09:21 +1000555 server_init_dispatch();
556
Damien Miller95def091999-11-25 00:26:21 +1100557 /* Main loop of the server for the interactive session mode. */
558 for (;;) {
Damien Miller95def091999-11-25 00:26:21 +1100559
560 /* Process buffered packets from the client. */
561 process_buffered_input_packets();
562
Damien Miller5428f641999-11-25 11:54:57 +1100563 /*
564 * If we have received eof, and there is no more pending
565 * input data, cause a real eof by closing fdin.
566 */
Damien Miller95def091999-11-25 00:26:21 +1100567 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000568 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100569 close(fdin);
570 else
571 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100572 fdin = -1;
573 }
Damien Miller5428f641999-11-25 11:54:57 +1100574 /* Make packets from buffered stderr data to send to the client. */
Damien Miller95def091999-11-25 00:26:21 +1100575 make_packets_from_stderr_data();
576
Damien Miller5428f641999-11-25 11:54:57 +1100577 /*
578 * Make packets from buffered stdout data to send to the
579 * client. If there is very little to send, this arranges to
580 * not send them now, but to wait a short while to see if we
581 * are getting more data. This is necessary, as some systems
582 * wake up readers from a pty after each separate character.
583 */
Damien Miller95def091999-11-25 00:26:21 +1100584 max_time_milliseconds = 0;
585 stdout_buffer_bytes = buffer_len(&stdout_buffer);
586 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
587 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
588 /* try again after a while */
589 max_time_milliseconds = 10;
590 } else {
591 /* Send it now. */
592 make_packets_from_stdout_data();
593 }
594 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
595
596 /* Send channel data to the client. */
597 if (packet_not_very_much_data_to_write())
598 channel_output_poll();
599
Damien Miller5428f641999-11-25 11:54:57 +1100600 /*
601 * Bail out of the loop if the program has closed its output
602 * descriptors, and we have no more data to send to the
603 * client, and there is no pending buffered data.
604 */
Damien Miller43dc8da2000-11-29 15:55:17 +1100605 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
606 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
Damien Miller95def091999-11-25 00:26:21 +1100607 if (!channel_still_open())
Damien Millerb38eff82000-04-01 11:09:21 +1000608 break;
Damien Miller95def091999-11-25 00:26:21 +1100609 if (!waiting_termination) {
610 const char *s = "Waiting for forwarded connections to terminate...\r\n";
611 char *cp;
612 waiting_termination = 1;
613 buffer_append(&stderr_buffer, s, strlen(s));
614
615 /* Display list of open channels. */
616 cp = channel_open_message();
617 buffer_append(&stderr_buffer, cp, strlen(cp));
618 xfree(cp);
619 }
620 }
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000621 max_fd = MAX(connection_in, connection_out);
622 max_fd = MAX(max_fd, fdin);
623 max_fd = MAX(max_fd, fdout);
624 max_fd = MAX(max_fd, fderr);
Damien Millerf6681a32001-12-21 14:53:11 +1100625 max_fd = MAX(max_fd, notify_pipe[0]);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000626
Damien Miller95def091999-11-25 00:26:21 +1100627 /* Sleep in select() until we can do something. */
Damien Miller5e953212001-01-30 09:14:00 +1100628 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000629 &nalloc, max_time_milliseconds);
Damien Miller95def091999-11-25 00:26:21 +1100630
631 /* Process any channel events. */
Damien Miller5e953212001-01-30 09:14:00 +1100632 channel_after_select(readset, writeset);
Damien Miller95def091999-11-25 00:26:21 +1100633
634 /* Process input from the client and from program stdout/stderr. */
Damien Miller5e953212001-01-30 09:14:00 +1100635 process_input(readset);
Damien Miller95def091999-11-25 00:26:21 +1100636
637 /* Process output to the client and to program stdin. */
Damien Miller5e953212001-01-30 09:14:00 +1100638 process_output(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100639 }
Damien Miller5e953212001-01-30 09:14:00 +1100640 if (readset)
641 xfree(readset);
642 if (writeset)
643 xfree(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100644
Damien Miller95def091999-11-25 00:26:21 +1100645 /* Cleanup and termination code. */
646
647 /* Wait until all output has been sent to the client. */
648 drain_output();
649
650 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100651 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
Damien Miller95def091999-11-25 00:26:21 +1100652
653 /* Free and clear the buffers. */
654 buffer_free(&stdin_buffer);
655 buffer_free(&stdout_buffer);
656 buffer_free(&stderr_buffer);
657
658 /* Close the file descriptors. */
659 if (fdout != -1)
660 close(fdout);
661 fdout = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000662 fdout_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100663 if (fderr != -1)
664 close(fderr);
665 fderr = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000666 fderr_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100667 if (fdin != -1)
668 close(fdin);
669 fdin = -1;
670
Ben Lindstrom601e4362001-06-21 03:19:23 +0000671 channel_free_all();
Damien Miller95def091999-11-25 00:26:21 +1100672
Damien Miller95def091999-11-25 00:26:21 +1100673 /* We no longer want our SIGCHLD handler to be called. */
Kevin Stevese26a1552001-07-26 17:51:49 +0000674 mysignal(SIGCHLD, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100675
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000676 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
677 if (errno != EINTR)
678 packet_disconnect("wait: %.100s", strerror(errno));
679 if (wait_pid != pid)
Ben Lindstromce0f6342002-06-11 16:42:49 +0000680 error("Strange, wait returned pid %ld, expected %ld",
681 (long)wait_pid, (long)pid);
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000682
Damien Miller95def091999-11-25 00:26:21 +1100683 /* Check if it exited normally. */
684 if (WIFEXITED(wait_status)) {
685 /* Yes, normal exit. Get exit status and send it to the client. */
686 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
687 packet_start(SSH_SMSG_EXITSTATUS);
688 packet_put_int(WEXITSTATUS(wait_status));
689 packet_send();
690 packet_write_wait();
691
Damien Miller5428f641999-11-25 11:54:57 +1100692 /*
693 * Wait for exit confirmation. Note that there might be
694 * other packets coming before it; however, the program has
695 * already died so we just ignore them. The client is
696 * supposed to respond with the confirmation when it receives
697 * the exit status.
698 */
Damien Miller95def091999-11-25 00:26:21 +1100699 do {
Damien Millerdff50992002-01-22 23:16:32 +1100700 type = packet_read();
Damien Miller95def091999-11-25 00:26:21 +1100701 }
702 while (type != SSH_CMSG_EXIT_CONFIRMATION);
703
704 debug("Received exit confirmation.");
705 return;
706 }
707 /* Check if the program terminated due to a signal. */
708 if (WIFSIGNALED(wait_status))
709 packet_disconnect("Command terminated on signal %d.",
710 WTERMSIG(wait_status));
711
712 /* Some weird exit cause. Just exit. */
713 packet_disconnect("wait returned status %04x.", wait_status);
714 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000715}
Damien Millerb38eff82000-04-01 11:09:21 +1000716
Damien Miller3ec27592001-10-12 11:35:04 +1000717static void
718collect_children(void)
719{
720 pid_t pid;
721 sigset_t oset, nset;
722 int status;
723
724 /* block SIGCHLD while we check for dead children */
725 sigemptyset(&nset);
726 sigaddset(&nset, SIGCHLD);
727 sigprocmask(SIG_BLOCK, &nset, &oset);
728 if (child_terminated) {
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000729 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
730 (pid < 0 && errno == EINTR))
731 if (pid > 0)
732 session_close_by_pid(pid, status);
Damien Miller3ec27592001-10-12 11:35:04 +1000733 child_terminated = 0;
734 }
735 sigprocmask(SIG_SETMASK, &oset, NULL);
736}
737
Damien Miller4af51302000-04-16 11:18:38 +1000738void
Ben Lindstrombddd5512001-07-04 04:53:53 +0000739server_loop2(Authctxt *authctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000740{
Damien Miller5e953212001-01-30 09:14:00 +1100741 fd_set *readset = NULL, *writeset = NULL;
Damien Miller3ec27592001-10-12 11:35:04 +1000742 int rekeying = 0, max_fd, nalloc = 0;
Damien Millerefb4afe2000-04-12 18:45:05 +1000743
744 debug("Entering interactive session for SSH2.");
745
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000746 mysignal(SIGCHLD, sigchld_handler);
Damien Millerefb4afe2000-04-12 18:45:05 +1000747 child_terminated = 0;
748 connection_in = packet_get_connection_in();
749 connection_out = packet_get_connection_out();
Damien Miller5e953212001-01-30 09:14:00 +1100750
Damien Millerf6681a32001-12-21 14:53:11 +1100751 notify_setup();
752
Damien Miller5e953212001-01-30 09:14:00 +1100753 max_fd = MAX(connection_in, connection_out);
Damien Millerf6681a32001-12-21 14:53:11 +1100754 max_fd = MAX(max_fd, notify_pipe[0]);
755
Damien Millerefb4afe2000-04-12 18:45:05 +1000756 server_init_dispatch();
757
758 for (;;) {
759 process_buffered_input_packets();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000760
Ben Lindstroma3700052001-04-05 23:26:32 +0000761 rekeying = (xxx_kex != NULL && !xxx_kex->done);
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000762
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000763 if (!rekeying && packet_not_very_much_data_to_write())
Damien Millerefb4afe2000-04-12 18:45:05 +1000764 channel_output_poll();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000765 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000766 &nalloc, 0);
Damien Miller52b77be2001-10-10 15:14:37 +1000767
Damien Miller3ec27592001-10-12 11:35:04 +1000768 collect_children();
Damien Millera5539d22003-04-09 20:50:06 +1000769 if (!rekeying) {
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000770 channel_after_select(readset, writeset);
Damien Millera5539d22003-04-09 20:50:06 +1000771 if (packet_need_rekeying()) {
772 debug("need rekeying");
773 xxx_kex->done = 0;
774 kex_send_kexinit(xxx_kex);
775 }
776 }
Damien Miller5e953212001-01-30 09:14:00 +1100777 process_input(readset);
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000778 if (connection_closed)
779 break;
Damien Miller5e953212001-01-30 09:14:00 +1100780 process_output(writeset);
Damien Millerefb4afe2000-04-12 18:45:05 +1000781 }
Damien Miller3ec27592001-10-12 11:35:04 +1000782 collect_children();
783
Damien Miller5e953212001-01-30 09:14:00 +1100784 if (readset)
785 xfree(readset);
786 if (writeset)
787 xfree(writeset);
788
Damien Miller52b77be2001-10-10 15:14:37 +1000789 /* free all channels, no more reads and writes */
790 channel_free_all();
Ben Lindstrom4983d5e2001-07-04 05:17:40 +0000791
Damien Miller3ec27592001-10-12 11:35:04 +1000792 /* free remaining sessions, e.g. remove wtmp entries */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000793 session_destroy_all(NULL);
Damien Millerefb4afe2000-04-12 18:45:05 +1000794}
795
Ben Lindstrombba81212001-06-25 05:01:22 +0000796static void
Damien Millerb5820f42003-12-17 16:27:32 +1100797server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000798{
Damien Millerb5820f42003-12-17 16:27:32 +1100799 debug("Got %d/%u for keepalive", type, seq);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100800 /*
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000801 * reset timeout, since we got a sane answer from the client.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000802 * even if this was generated by something other than
803 * the bogus CHANNEL_REQUEST we send for keepalives.
804 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100805 client_alive_timeouts = 0;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000806}
807
Ben Lindstrombba81212001-06-25 05:01:22 +0000808static void
Damien Miller630d6f42002-01-22 23:17:30 +1100809server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000810{
811 char *data;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000812 u_int data_len;
Damien Millerb38eff82000-04-01 11:09:21 +1000813
814 /* Stdin data from the client. Append it to the buffer. */
815 /* Ignore any data if the client has closed stdin. */
816 if (fdin == -1)
817 return;
818 data = packet_get_string(&data_len);
Damien Miller48b03fc2002-01-22 23:11:40 +1100819 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000820 buffer_append(&stdin_buffer, data, data_len);
821 memset(data, 0, data_len);
822 xfree(data);
823}
824
Ben Lindstrombba81212001-06-25 05:01:22 +0000825static void
Damien Miller630d6f42002-01-22 23:17:30 +1100826server_input_eof(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000827{
828 /*
829 * Eof from the client. The stdin descriptor to the
830 * program will be closed when all buffered data has
831 * drained.
832 */
833 debug("EOF received for stdin.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100834 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000835 stdin_eof = 1;
836}
837
Ben Lindstrombba81212001-06-25 05:01:22 +0000838static void
Damien Miller630d6f42002-01-22 23:17:30 +1100839server_input_window_size(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000840{
841 int row = packet_get_int();
842 int col = packet_get_int();
843 int xpixel = packet_get_int();
844 int ypixel = packet_get_int();
845
846 debug("Window change received.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100847 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000848 if (fdin != -1)
849 pty_change_window_size(fdin, row, col, xpixel, ypixel);
850}
851
Ben Lindstrombba81212001-06-25 05:01:22 +0000852static Channel *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100853server_request_direct_tcpip(char *ctype)
Damien Millerefb4afe2000-04-12 18:45:05 +1000854{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000855 Channel *c;
856 int sock;
Damien Miller4af51302000-04-16 11:18:38 +1000857 char *target, *originator;
858 int target_port, originator_port;
Damien Millerefb4afe2000-04-12 18:45:05 +1000859
Damien Miller4af51302000-04-16 11:18:38 +1000860 target = packet_get_string(NULL);
861 target_port = packet_get_int();
Damien Millerefb4afe2000-04-12 18:45:05 +1000862 originator = packet_get_string(NULL);
863 originator_port = packet_get_int();
Damien Miller48b03fc2002-01-22 23:11:40 +1100864 packet_check_eom();
Damien Millerb1715dc2000-05-30 13:44:51 +1000865
Damien Miller0bc1bd82000-11-13 22:57:25 +1100866 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
Damien Millerb1715dc2000-05-30 13:44:51 +1000867 originator, originator_port, target, target_port);
Damien Millerf6d9e222000-06-18 14:50:44 +1000868
Damien Millerefb4afe2000-04-12 18:45:05 +1000869 /* XXX check permission */
Damien Miller4af51302000-04-16 11:18:38 +1000870 sock = channel_connect_to(target, target_port);
871 xfree(target);
Damien Millerefb4afe2000-04-12 18:45:05 +1000872 xfree(originator);
873 if (sock < 0)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100874 return NULL;
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000875 c = channel_new(ctype, SSH_CHANNEL_CONNECTING,
Damien Millere4340be2000-09-16 13:29:08 +1100876 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000877 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000878 return c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100879}
880
Ben Lindstrombba81212001-06-25 05:01:22 +0000881static Channel *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100882server_request_session(char *ctype)
883{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000884 Channel *c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100885
886 debug("input_session_request");
Damien Miller48b03fc2002-01-22 23:11:40 +1100887 packet_check_eom();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100888 /*
889 * A server session has no fd to read or write until a
890 * CHANNEL_REQUEST for a shell is made, so we set the type to
891 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
892 * CHANNEL_REQUEST messages is registered.
893 */
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000894 c = channel_new(ctype, SSH_CHANNEL_LARVAL,
895 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000896 0, "server-session", 1);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000897 if (session_open(the_authctxt, c->self) != 1) {
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000898 debug("session open failed, free channel %d", c->self);
899 channel_free(c);
900 return NULL;
901 }
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000902 channel_register_cleanup(c->self, session_close_by_channel);
903 return c;
Damien Millerefb4afe2000-04-12 18:45:05 +1000904}
905
Ben Lindstrombba81212001-06-25 05:01:22 +0000906static void
Damien Miller630d6f42002-01-22 23:17:30 +1100907server_input_channel_open(int type, u_int32_t seq, void *ctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000908{
909 Channel *c = NULL;
910 char *ctype;
Damien Millerefb4afe2000-04-12 18:45:05 +1000911 int rchan;
Ben Lindstrom4fed2be2002-06-25 23:17:36 +0000912 u_int rmaxpack, rwindow, len;
Damien Millerefb4afe2000-04-12 18:45:05 +1000913
914 ctype = packet_get_string(&len);
915 rchan = packet_get_int();
916 rwindow = packet_get_int();
917 rmaxpack = packet_get_int();
918
Damien Miller62cee002000-09-23 17:15:56 +1100919 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
Damien Millerefb4afe2000-04-12 18:45:05 +1000920 ctype, rchan, rwindow, rmaxpack);
921
922 if (strcmp(ctype, "session") == 0) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100923 c = server_request_session(ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000924 } else if (strcmp(ctype, "direct-tcpip") == 0) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100925 c = server_request_direct_tcpip(ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000926 }
927 if (c != NULL) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100928 debug("server_input_channel_open: confirm %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000929 c->remote_id = rchan;
930 c->remote_window = rwindow;
931 c->remote_maxpacket = rmaxpack;
Ben Lindstrom69128662001-05-08 20:07:39 +0000932 if (c->type != SSH_CHANNEL_CONNECTING) {
933 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
934 packet_put_int(c->remote_id);
935 packet_put_int(c->self);
936 packet_put_int(c->local_window);
937 packet_put_int(c->local_maxpacket);
938 packet_send();
939 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000940 } else {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100941 debug("server_input_channel_open: failure %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000942 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
943 packet_put_int(rchan);
944 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
Ben Lindstromf3436742001-04-29 19:52:00 +0000945 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
Ben Lindstrom69128662001-05-08 20:07:39 +0000946 packet_put_cstring("open failed");
Ben Lindstromf3436742001-04-29 19:52:00 +0000947 packet_put_cstring("");
948 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000949 packet_send();
950 }
951 xfree(ctype);
952}
953
Ben Lindstrombba81212001-06-25 05:01:22 +0000954static void
Damien Miller630d6f42002-01-22 23:17:30 +1100955server_input_global_request(int type, u_int32_t seq, void *ctxt)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100956{
957 char *rtype;
958 int want_reply;
959 int success = 0;
960
961 rtype = packet_get_string(NULL);
962 want_reply = packet_get_char();
963 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
Kevin Stevesef4eea92001-02-05 12:42:17 +0000964
Ben Lindstrom7bb8b492001-03-17 00:47:54 +0000965 /* -R style forwarding */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100966 if (strcmp(rtype, "tcpip-forward") == 0) {
967 struct passwd *pw;
968 char *listen_address;
969 u_short listen_port;
970
Darren Tucker3e33cec2003-10-02 16:12:36 +1000971 pw = the_authctxt->pw;
Damien Miller4bb1dd32003-11-18 22:01:25 +1100972 if (pw == NULL || !the_authctxt->valid)
Damien Miller3e3b5142003-11-17 21:13:40 +1100973 fatal("server_input_global_request: no/invalid user");
Damien Miller9fc7c692003-06-04 22:50:54 +1000974 listen_address = packet_get_string(NULL);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100975 listen_port = (u_short)packet_get_int();
976 debug("server_input_global_request: tcpip-forward listen %s port %d",
977 listen_address, listen_port);
978
979 /* check permissions */
980 if (!options.allow_tcp_forwarding ||
Ben Lindstrom99a4e142002-07-09 14:06:40 +0000981 no_port_forwarding_flag
982#ifndef NO_IPPORT_RESERVED_CONCEPT
983 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
984#endif
985 ) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100986 success = 0;
987 packet_send_debug("Server has disabled port forwarding.");
988 } else {
989 /* Start listening on the port */
Damien Millerb16461c2002-01-22 23:29:22 +1100990 success = channel_setup_remote_fwd_listener(
991 listen_address, listen_port, options.gateway_ports);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100992 }
993 xfree(listen_address);
994 }
995 if (want_reply) {
996 packet_start(success ?
997 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
998 packet_send();
999 packet_write_wait();
1000 }
1001 xfree(rtype);
1002}
Damien Millerc7ef63d2002-02-05 12:21:42 +11001003static void
1004server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1005{
1006 Channel *c;
1007 int id, reply, success = 0;
1008 char *rtype;
1009
1010 id = packet_get_int();
1011 rtype = packet_get_string(NULL);
1012 reply = packet_get_char();
1013
1014 debug("server_input_channel_req: channel %d request %s reply %d",
1015 id, rtype, reply);
1016
1017 if ((c = channel_lookup(id)) == NULL)
1018 packet_disconnect("server_input_channel_req: "
1019 "unknown channel %d", id);
1020 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1021 success = session_input_channel_req(c, rtype);
1022 if (reply) {
1023 packet_start(success ?
1024 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1025 packet_put_int(c->remote_id);
1026 packet_send();
1027 }
1028 xfree(rtype);
1029}
Damien Miller0bc1bd82000-11-13 22:57:25 +11001030
Ben Lindstrombba81212001-06-25 05:01:22 +00001031static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001032server_init_dispatch_20(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10001033{
1034 debug("server_init_dispatch_20");
1035 dispatch_init(&dispatch_protocol_error);
1036 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1037 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1038 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1039 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1040 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1041 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1042 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
Damien Millerc7ef63d2002-02-05 12:21:42 +11001043 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
Damien Millerefb4afe2000-04-12 18:45:05 +10001044 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001045 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
Ben Lindstrom5744dc42001-04-13 23:28:01 +00001046 /* client_alive */
Damien Millerb5820f42003-12-17 16:27:32 +11001047 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1048 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1049 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001050 /* rekeying */
1051 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
Damien Millerefb4afe2000-04-12 18:45:05 +10001052}
Ben Lindstrombba81212001-06-25 05:01:22 +00001053static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001054server_init_dispatch_13(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001055{
1056 debug("server_init_dispatch_13");
1057 dispatch_init(NULL);
1058 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1059 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1060 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1061 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1062 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1063 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1064 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1065 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1066 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1067}
Ben Lindstrombba81212001-06-25 05:01:22 +00001068static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001069server_init_dispatch_15(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001070{
1071 server_init_dispatch_13();
1072 debug("server_init_dispatch_15");
1073 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1074 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1075}
Ben Lindstrombba81212001-06-25 05:01:22 +00001076static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001077server_init_dispatch(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001078{
Damien Millerefb4afe2000-04-12 18:45:05 +10001079 if (compat20)
1080 server_init_dispatch_20();
1081 else if (compat13)
Damien Millerb38eff82000-04-01 11:09:21 +10001082 server_init_dispatch_13();
1083 else
1084 server_init_dispatch_15();
1085}