blob: d2eff170a9042565450a7e65c28be0a147c4bdba [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 Miller0dc1bef2005-07-17 17:22:45 +100038RCSID("$OpenBSD: serverloop.c,v 1.118 2005/07/17 07:17:55 djm 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,
Darren Tuckerc7a6fc42004-08-13 21:18:00 +1000243 u_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;
Darren Tuckerc7a6fc42004-08-13 21:18:00 +1000489 int max_fd = 0;
490 u_int nalloc = 0;
Damien Miller166fca82000-04-20 07:42:21 +1000491 int wait_status; /* Status returned by wait(). */
492 pid_t wait_pid; /* pid returned by wait(). */
Damien Miller95def091999-11-25 00:26:21 +1100493 int waiting_termination = 0; /* Have displayed waiting close message. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000494 u_int max_time_milliseconds;
495 u_int previous_stdout_buffer_bytes;
496 u_int stdout_buffer_bytes;
Damien Miller95def091999-11-25 00:26:21 +1100497 int type;
498
499 debug("Entering interactive session.");
500
501 /* Initialize the SIGCHLD kludge. */
Damien Miller95def091999-11-25 00:26:21 +1100502 child_terminated = 0;
Kevin Stevese26a1552001-07-26 17:51:49 +0000503 mysignal(SIGCHLD, sigchld_handler);
Damien Miller95def091999-11-25 00:26:21 +1100504
505 /* Initialize our global variables. */
506 fdin = fdin_arg;
507 fdout = fdout_arg;
508 fderr = fderr_arg;
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000509
510 /* nonblocking IO */
511 set_nonblock(fdin);
512 set_nonblock(fdout);
Damien Miller7d6656c2000-05-20 15:22:36 +1000513 /* we don't have stderr for interactive terminal sessions, see below */
514 if (fderr != -1)
515 set_nonblock(fderr);
Damien Millerdcb6ecd2000-05-17 22:34:22 +1000516
Damien Miller225736c2001-02-19 21:51:08 +1100517 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
518 fdin_is_tty = 1;
519
Damien Miller95def091999-11-25 00:26:21 +1100520 connection_in = packet_get_connection_in();
521 connection_out = packet_get_connection_out();
522
Damien Millerf6681a32001-12-21 14:53:11 +1100523 notify_setup();
524
Damien Miller95def091999-11-25 00:26:21 +1100525 previous_stdout_buffer_bytes = 0;
526
527 /* Set approximate I/O buffer size. */
528 if (packet_is_interactive())
529 buffer_high = 4096;
530 else
531 buffer_high = 64 * 1024;
532
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000533#if 0
Damien Miller95def091999-11-25 00:26:21 +1100534 /* Initialize max_fd to the maximum of the known file descriptors. */
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000535 max_fd = MAX(connection_in, connection_out);
536 max_fd = MAX(max_fd, fdin);
537 max_fd = MAX(max_fd, fdout);
Damien Miller5e953212001-01-30 09:14:00 +1100538 if (fderr != -1)
539 max_fd = MAX(max_fd, fderr);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000540#endif
Damien Miller95def091999-11-25 00:26:21 +1100541
542 /* Initialize Initialize buffers. */
543 buffer_init(&stdin_buffer);
544 buffer_init(&stdout_buffer);
545 buffer_init(&stderr_buffer);
546
Damien Miller5428f641999-11-25 11:54:57 +1100547 /*
548 * If we have no separate fderr (which is the case when we have a pty
549 * - there we cannot make difference between data sent to stdout and
550 * stderr), indicate that we have seen an EOF from stderr. This way
551 * we don\'t need to check the descriptor everywhere.
552 */
Damien Miller95def091999-11-25 00:26:21 +1100553 if (fderr == -1)
554 fderr_eof = 1;
555
Damien Millerb38eff82000-04-01 11:09:21 +1000556 server_init_dispatch();
557
Damien Miller95def091999-11-25 00:26:21 +1100558 /* Main loop of the server for the interactive session mode. */
559 for (;;) {
Damien Miller95def091999-11-25 00:26:21 +1100560
561 /* Process buffered packets from the client. */
562 process_buffered_input_packets();
563
Damien Miller5428f641999-11-25 11:54:57 +1100564 /*
565 * If we have received eof, and there is no more pending
566 * input data, cause a real eof by closing fdin.
567 */
Damien Miller95def091999-11-25 00:26:21 +1100568 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000569 if (fdin != fdout)
Damien Miller95def091999-11-25 00:26:21 +1100570 close(fdin);
571 else
572 shutdown(fdin, SHUT_WR); /* We will no longer send. */
Damien Miller95def091999-11-25 00:26:21 +1100573 fdin = -1;
574 }
Damien Miller5428f641999-11-25 11:54:57 +1100575 /* Make packets from buffered stderr data to send to the client. */
Damien Miller95def091999-11-25 00:26:21 +1100576 make_packets_from_stderr_data();
577
Damien Miller5428f641999-11-25 11:54:57 +1100578 /*
579 * Make packets from buffered stdout data to send to the
580 * client. If there is very little to send, this arranges to
581 * not send them now, but to wait a short while to see if we
582 * are getting more data. This is necessary, as some systems
583 * wake up readers from a pty after each separate character.
584 */
Damien Miller95def091999-11-25 00:26:21 +1100585 max_time_milliseconds = 0;
586 stdout_buffer_bytes = buffer_len(&stdout_buffer);
587 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
588 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
589 /* try again after a while */
590 max_time_milliseconds = 10;
591 } else {
592 /* Send it now. */
593 make_packets_from_stdout_data();
594 }
595 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
596
597 /* Send channel data to the client. */
598 if (packet_not_very_much_data_to_write())
599 channel_output_poll();
600
Damien Miller5428f641999-11-25 11:54:57 +1100601 /*
602 * Bail out of the loop if the program has closed its output
603 * descriptors, and we have no more data to send to the
604 * client, and there is no pending buffered data.
605 */
Damien Miller43dc8da2000-11-29 15:55:17 +1100606 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
607 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
Damien Miller95def091999-11-25 00:26:21 +1100608 if (!channel_still_open())
Damien Millerb38eff82000-04-01 11:09:21 +1000609 break;
Damien Miller95def091999-11-25 00:26:21 +1100610 if (!waiting_termination) {
611 const char *s = "Waiting for forwarded connections to terminate...\r\n";
612 char *cp;
613 waiting_termination = 1;
614 buffer_append(&stderr_buffer, s, strlen(s));
615
616 /* Display list of open channels. */
617 cp = channel_open_message();
618 buffer_append(&stderr_buffer, cp, strlen(cp));
619 xfree(cp);
620 }
621 }
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000622 max_fd = MAX(connection_in, connection_out);
623 max_fd = MAX(max_fd, fdin);
624 max_fd = MAX(max_fd, fdout);
625 max_fd = MAX(max_fd, fderr);
Damien Millerf6681a32001-12-21 14:53:11 +1100626 max_fd = MAX(max_fd, notify_pipe[0]);
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000627
Damien Miller95def091999-11-25 00:26:21 +1100628 /* Sleep in select() until we can do something. */
Damien Miller5e953212001-01-30 09:14:00 +1100629 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000630 &nalloc, max_time_milliseconds);
Damien Miller95def091999-11-25 00:26:21 +1100631
632 /* Process any channel events. */
Damien Miller5e953212001-01-30 09:14:00 +1100633 channel_after_select(readset, writeset);
Damien Miller95def091999-11-25 00:26:21 +1100634
635 /* Process input from the client and from program stdout/stderr. */
Damien Miller5e953212001-01-30 09:14:00 +1100636 process_input(readset);
Damien Miller95def091999-11-25 00:26:21 +1100637
638 /* Process output to the client and to program stdin. */
Damien Miller5e953212001-01-30 09:14:00 +1100639 process_output(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100640 }
Damien Miller5e953212001-01-30 09:14:00 +1100641 if (readset)
642 xfree(readset);
643 if (writeset)
644 xfree(writeset);
Damien Miller95def091999-11-25 00:26:21 +1100645
Damien Miller95def091999-11-25 00:26:21 +1100646 /* Cleanup and termination code. */
647
648 /* Wait until all output has been sent to the client. */
649 drain_output();
650
651 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100652 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
Damien Miller95def091999-11-25 00:26:21 +1100653
654 /* Free and clear the buffers. */
655 buffer_free(&stdin_buffer);
656 buffer_free(&stdout_buffer);
657 buffer_free(&stderr_buffer);
658
659 /* Close the file descriptors. */
660 if (fdout != -1)
661 close(fdout);
662 fdout = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000663 fdout_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100664 if (fderr != -1)
665 close(fderr);
666 fderr = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000667 fderr_eof = 1;
Damien Miller95def091999-11-25 00:26:21 +1100668 if (fdin != -1)
669 close(fdin);
670 fdin = -1;
671
Ben Lindstrom601e4362001-06-21 03:19:23 +0000672 channel_free_all();
Damien Miller95def091999-11-25 00:26:21 +1100673
Damien Miller95def091999-11-25 00:26:21 +1100674 /* We no longer want our SIGCHLD handler to be called. */
Kevin Stevese26a1552001-07-26 17:51:49 +0000675 mysignal(SIGCHLD, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100676
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000677 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
678 if (errno != EINTR)
679 packet_disconnect("wait: %.100s", strerror(errno));
680 if (wait_pid != pid)
Ben Lindstromce0f6342002-06-11 16:42:49 +0000681 error("Strange, wait returned pid %ld, expected %ld",
682 (long)wait_pid, (long)pid);
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000683
Damien Miller95def091999-11-25 00:26:21 +1100684 /* Check if it exited normally. */
685 if (WIFEXITED(wait_status)) {
686 /* Yes, normal exit. Get exit status and send it to the client. */
687 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
688 packet_start(SSH_SMSG_EXITSTATUS);
689 packet_put_int(WEXITSTATUS(wait_status));
690 packet_send();
691 packet_write_wait();
692
Damien Miller5428f641999-11-25 11:54:57 +1100693 /*
694 * Wait for exit confirmation. Note that there might be
695 * other packets coming before it; however, the program has
696 * already died so we just ignore them. The client is
697 * supposed to respond with the confirmation when it receives
698 * the exit status.
699 */
Damien Miller95def091999-11-25 00:26:21 +1100700 do {
Damien Millerdff50992002-01-22 23:16:32 +1100701 type = packet_read();
Damien Miller95def091999-11-25 00:26:21 +1100702 }
703 while (type != SSH_CMSG_EXIT_CONFIRMATION);
704
705 debug("Received exit confirmation.");
706 return;
707 }
708 /* Check if the program terminated due to a signal. */
709 if (WIFSIGNALED(wait_status))
710 packet_disconnect("Command terminated on signal %d.",
711 WTERMSIG(wait_status));
712
713 /* Some weird exit cause. Just exit. */
714 packet_disconnect("wait returned status %04x.", wait_status);
715 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000716}
Damien Millerb38eff82000-04-01 11:09:21 +1000717
Damien Miller3ec27592001-10-12 11:35:04 +1000718static void
719collect_children(void)
720{
721 pid_t pid;
722 sigset_t oset, nset;
723 int status;
724
725 /* block SIGCHLD while we check for dead children */
726 sigemptyset(&nset);
727 sigaddset(&nset, SIGCHLD);
728 sigprocmask(SIG_BLOCK, &nset, &oset);
729 if (child_terminated) {
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000730 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
731 (pid < 0 && errno == EINTR))
732 if (pid > 0)
733 session_close_by_pid(pid, status);
Damien Miller3ec27592001-10-12 11:35:04 +1000734 child_terminated = 0;
735 }
736 sigprocmask(SIG_SETMASK, &oset, NULL);
737}
738
Damien Miller4af51302000-04-16 11:18:38 +1000739void
Ben Lindstrombddd5512001-07-04 04:53:53 +0000740server_loop2(Authctxt *authctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000741{
Damien Miller5e953212001-01-30 09:14:00 +1100742 fd_set *readset = NULL, *writeset = NULL;
Damien Miller3ec27592001-10-12 11:35:04 +1000743 int rekeying = 0, max_fd, nalloc = 0;
Damien Millerefb4afe2000-04-12 18:45:05 +1000744
745 debug("Entering interactive session for SSH2.");
746
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000747 mysignal(SIGCHLD, sigchld_handler);
Damien Millerefb4afe2000-04-12 18:45:05 +1000748 child_terminated = 0;
749 connection_in = packet_get_connection_in();
750 connection_out = packet_get_connection_out();
Damien Miller5e953212001-01-30 09:14:00 +1100751
Damien Millerf6681a32001-12-21 14:53:11 +1100752 notify_setup();
753
Damien Miller5e953212001-01-30 09:14:00 +1100754 max_fd = MAX(connection_in, connection_out);
Damien Millerf6681a32001-12-21 14:53:11 +1100755 max_fd = MAX(max_fd, notify_pipe[0]);
756
Damien Millerefb4afe2000-04-12 18:45:05 +1000757 server_init_dispatch();
758
759 for (;;) {
760 process_buffered_input_packets();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000761
Ben Lindstroma3700052001-04-05 23:26:32 +0000762 rekeying = (xxx_kex != NULL && !xxx_kex->done);
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000763
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000764 if (!rekeying && packet_not_very_much_data_to_write())
Damien Millerefb4afe2000-04-12 18:45:05 +1000765 channel_output_poll();
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000766 wait_until_can_do_something(&readset, &writeset, &max_fd,
Ben Lindstrom16d29d52001-07-18 16:01:46 +0000767 &nalloc, 0);
Damien Miller52b77be2001-10-10 15:14:37 +1000768
Damien Miller3ec27592001-10-12 11:35:04 +1000769 collect_children();
Damien Millera5539d22003-04-09 20:50:06 +1000770 if (!rekeying) {
Ben Lindstrom8e312f32001-04-04 23:50:21 +0000771 channel_after_select(readset, writeset);
Damien Millera5539d22003-04-09 20:50:06 +1000772 if (packet_need_rekeying()) {
773 debug("need rekeying");
774 xxx_kex->done = 0;
775 kex_send_kexinit(xxx_kex);
776 }
777 }
Damien Miller5e953212001-01-30 09:14:00 +1100778 process_input(readset);
Ben Lindstrome34ab4c2001-04-07 01:12:11 +0000779 if (connection_closed)
780 break;
Damien Miller5e953212001-01-30 09:14:00 +1100781 process_output(writeset);
Damien Millerefb4afe2000-04-12 18:45:05 +1000782 }
Damien Miller3ec27592001-10-12 11:35:04 +1000783 collect_children();
784
Damien Miller5e953212001-01-30 09:14:00 +1100785 if (readset)
786 xfree(readset);
787 if (writeset)
788 xfree(writeset);
789
Damien Miller52b77be2001-10-10 15:14:37 +1000790 /* free all channels, no more reads and writes */
791 channel_free_all();
Ben Lindstrom4983d5e2001-07-04 05:17:40 +0000792
Damien Miller3ec27592001-10-12 11:35:04 +1000793 /* free remaining sessions, e.g. remove wtmp entries */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000794 session_destroy_all(NULL);
Damien Millerefb4afe2000-04-12 18:45:05 +1000795}
796
Ben Lindstrombba81212001-06-25 05:01:22 +0000797static void
Damien Millerb5820f42003-12-17 16:27:32 +1100798server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000799{
Damien Millerb5820f42003-12-17 16:27:32 +1100800 debug("Got %d/%u for keepalive", type, seq);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100801 /*
Ben Lindstrom2f0304c2001-04-29 19:49:14 +0000802 * reset timeout, since we got a sane answer from the client.
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000803 * even if this was generated by something other than
804 * the bogus CHANNEL_REQUEST we send for keepalives.
805 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100806 client_alive_timeouts = 0;
Ben Lindstrom5744dc42001-04-13 23:28:01 +0000807}
808
Ben Lindstrombba81212001-06-25 05:01:22 +0000809static void
Damien Miller630d6f42002-01-22 23:17:30 +1100810server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000811{
812 char *data;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000813 u_int data_len;
Damien Millerb38eff82000-04-01 11:09:21 +1000814
815 /* Stdin data from the client. Append it to the buffer. */
816 /* Ignore any data if the client has closed stdin. */
817 if (fdin == -1)
818 return;
819 data = packet_get_string(&data_len);
Damien Miller48b03fc2002-01-22 23:11:40 +1100820 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000821 buffer_append(&stdin_buffer, data, data_len);
822 memset(data, 0, data_len);
823 xfree(data);
824}
825
Ben Lindstrombba81212001-06-25 05:01:22 +0000826static void
Damien Miller630d6f42002-01-22 23:17:30 +1100827server_input_eof(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000828{
829 /*
830 * Eof from the client. The stdin descriptor to the
831 * program will be closed when all buffered data has
832 * drained.
833 */
834 debug("EOF received for stdin.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100835 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000836 stdin_eof = 1;
837}
838
Ben Lindstrombba81212001-06-25 05:01:22 +0000839static void
Damien Miller630d6f42002-01-22 23:17:30 +1100840server_input_window_size(int type, u_int32_t seq, void *ctxt)
Damien Millerb38eff82000-04-01 11:09:21 +1000841{
842 int row = packet_get_int();
843 int col = packet_get_int();
844 int xpixel = packet_get_int();
845 int ypixel = packet_get_int();
846
847 debug("Window change received.");
Damien Miller48b03fc2002-01-22 23:11:40 +1100848 packet_check_eom();
Damien Millerb38eff82000-04-01 11:09:21 +1000849 if (fdin != -1)
850 pty_change_window_size(fdin, row, col, xpixel, ypixel);
851}
852
Ben Lindstrombba81212001-06-25 05:01:22 +0000853static Channel *
Damien Millerfb1310e2004-01-21 11:02:50 +1100854server_request_direct_tcpip(void)
Damien Millerefb4afe2000-04-12 18:45:05 +1000855{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000856 Channel *c;
857 int sock;
Damien Miller4af51302000-04-16 11:18:38 +1000858 char *target, *originator;
859 int target_port, originator_port;
Damien Millerefb4afe2000-04-12 18:45:05 +1000860
Damien Miller4af51302000-04-16 11:18:38 +1000861 target = packet_get_string(NULL);
862 target_port = packet_get_int();
Damien Millerefb4afe2000-04-12 18:45:05 +1000863 originator = packet_get_string(NULL);
864 originator_port = packet_get_int();
Damien Miller48b03fc2002-01-22 23:11:40 +1100865 packet_check_eom();
Damien Millerb1715dc2000-05-30 13:44:51 +1000866
Damien Miller0bc1bd82000-11-13 22:57:25 +1100867 debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
Damien Miller0dc1bef2005-07-17 17:22:45 +1000868 originator, originator_port, target, target_port);
Damien Millerf6d9e222000-06-18 14:50:44 +1000869
Damien Millerefb4afe2000-04-12 18:45:05 +1000870 /* XXX check permission */
Damien Miller4af51302000-04-16 11:18:38 +1000871 sock = channel_connect_to(target, target_port);
872 xfree(target);
Damien Millerefb4afe2000-04-12 18:45:05 +1000873 xfree(originator);
874 if (sock < 0)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100875 return NULL;
Damien Millerfb1310e2004-01-21 11:02:50 +1100876 c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
Damien Millere4340be2000-09-16 13:29:08 +1100877 sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000878 CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000879 return c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100880}
881
Ben Lindstrombba81212001-06-25 05:01:22 +0000882static Channel *
Damien Millerfb1310e2004-01-21 11:02:50 +1100883server_request_session(void)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100884{
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000885 Channel *c;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100886
887 debug("input_session_request");
Damien Miller48b03fc2002-01-22 23:11:40 +1100888 packet_check_eom();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100889 /*
890 * A server session has no fd to read or write until a
891 * CHANNEL_REQUEST for a shell is made, so we set the type to
892 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
893 * CHANNEL_REQUEST messages is registered.
894 */
Damien Millerfb1310e2004-01-21 11:02:50 +1100895 c = channel_new("session", SSH_CHANNEL_LARVAL,
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000896 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
Damien Millerb1ca8bb2003-05-14 13:45:42 +1000897 0, "server-session", 1);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000898 if (session_open(the_authctxt, c->self) != 1) {
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000899 debug("session open failed, free channel %d", c->self);
900 channel_free(c);
901 return NULL;
902 }
Ben Lindstrom99c73b32001-05-05 04:09:47 +0000903 channel_register_cleanup(c->self, session_close_by_channel);
904 return c;
Damien Millerefb4afe2000-04-12 18:45:05 +1000905}
906
Ben Lindstrombba81212001-06-25 05:01:22 +0000907static void
Damien Miller630d6f42002-01-22 23:17:30 +1100908server_input_channel_open(int type, u_int32_t seq, void *ctxt)
Damien Millerefb4afe2000-04-12 18:45:05 +1000909{
910 Channel *c = NULL;
911 char *ctype;
Damien Millerefb4afe2000-04-12 18:45:05 +1000912 int rchan;
Ben Lindstrom4fed2be2002-06-25 23:17:36 +0000913 u_int rmaxpack, rwindow, len;
Damien Millerefb4afe2000-04-12 18:45:05 +1000914
915 ctype = packet_get_string(&len);
916 rchan = packet_get_int();
917 rwindow = packet_get_int();
918 rmaxpack = packet_get_int();
919
Damien Miller62cee002000-09-23 17:15:56 +1100920 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
Damien Millerefb4afe2000-04-12 18:45:05 +1000921 ctype, rchan, rwindow, rmaxpack);
922
923 if (strcmp(ctype, "session") == 0) {
Damien Millerfb1310e2004-01-21 11:02:50 +1100924 c = server_request_session();
Damien Millerefb4afe2000-04-12 18:45:05 +1000925 } else if (strcmp(ctype, "direct-tcpip") == 0) {
Damien Millerfb1310e2004-01-21 11:02:50 +1100926 c = server_request_direct_tcpip();
Damien Millerefb4afe2000-04-12 18:45:05 +1000927 }
928 if (c != NULL) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100929 debug("server_input_channel_open: confirm %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000930 c->remote_id = rchan;
931 c->remote_window = rwindow;
932 c->remote_maxpacket = rmaxpack;
Ben Lindstrom69128662001-05-08 20:07:39 +0000933 if (c->type != SSH_CHANNEL_CONNECTING) {
934 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
935 packet_put_int(c->remote_id);
936 packet_put_int(c->self);
937 packet_put_int(c->local_window);
938 packet_put_int(c->local_maxpacket);
939 packet_send();
940 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000941 } else {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100942 debug("server_input_channel_open: failure %s", ctype);
Damien Millerefb4afe2000-04-12 18:45:05 +1000943 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
944 packet_put_int(rchan);
945 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
Ben Lindstromf3436742001-04-29 19:52:00 +0000946 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
Ben Lindstrom69128662001-05-08 20:07:39 +0000947 packet_put_cstring("open failed");
Ben Lindstromf3436742001-04-29 19:52:00 +0000948 packet_put_cstring("");
949 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000950 packet_send();
951 }
952 xfree(ctype);
953}
954
Ben Lindstrombba81212001-06-25 05:01:22 +0000955static void
Damien Miller630d6f42002-01-22 23:17:30 +1100956server_input_global_request(int type, u_int32_t seq, void *ctxt)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100957{
958 char *rtype;
959 int want_reply;
960 int success = 0;
961
962 rtype = packet_get_string(NULL);
963 want_reply = packet_get_char();
964 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
Kevin Stevesef4eea92001-02-05 12:42:17 +0000965
Ben Lindstrom7bb8b492001-03-17 00:47:54 +0000966 /* -R style forwarding */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100967 if (strcmp(rtype, "tcpip-forward") == 0) {
968 struct passwd *pw;
969 char *listen_address;
970 u_short listen_port;
971
Darren Tucker3e33cec2003-10-02 16:12:36 +1000972 pw = the_authctxt->pw;
Damien Miller4bb1dd32003-11-18 22:01:25 +1100973 if (pw == NULL || !the_authctxt->valid)
Damien Miller3e3b5142003-11-17 21:13:40 +1100974 fatal("server_input_global_request: no/invalid user");
Damien Miller9fc7c692003-06-04 22:50:54 +1000975 listen_address = packet_get_string(NULL);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100976 listen_port = (u_short)packet_get_int();
977 debug("server_input_global_request: tcpip-forward listen %s port %d",
978 listen_address, listen_port);
979
980 /* check permissions */
981 if (!options.allow_tcp_forwarding ||
Ben Lindstrom99a4e142002-07-09 14:06:40 +0000982 no_port_forwarding_flag
983#ifndef NO_IPPORT_RESERVED_CONCEPT
984 || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
985#endif
Damien Millerb6f72f52005-07-17 17:26:43 +1000986 ) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100987 success = 0;
988 packet_send_debug("Server has disabled port forwarding.");
989 } else {
990 /* Start listening on the port */
Damien Millerb16461c2002-01-22 23:29:22 +1100991 success = channel_setup_remote_fwd_listener(
992 listen_address, listen_port, options.gateway_ports);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100993 }
994 xfree(listen_address);
Darren Tuckere7066df2004-05-24 10:18:05 +1000995 } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
996 char *cancel_address;
997 u_short cancel_port;
998
999 cancel_address = packet_get_string(NULL);
1000 cancel_port = (u_short)packet_get_int();
1001 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1002 cancel_address, cancel_port);
1003
1004 success = channel_cancel_rport_listener(cancel_address,
1005 cancel_port);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001006 }
1007 if (want_reply) {
1008 packet_start(success ?
1009 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1010 packet_send();
1011 packet_write_wait();
1012 }
1013 xfree(rtype);
1014}
Damien Millerc7ef63d2002-02-05 12:21:42 +11001015static void
1016server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1017{
1018 Channel *c;
1019 int id, reply, success = 0;
1020 char *rtype;
1021
1022 id = packet_get_int();
1023 rtype = packet_get_string(NULL);
1024 reply = packet_get_char();
1025
1026 debug("server_input_channel_req: channel %d request %s reply %d",
1027 id, rtype, reply);
1028
1029 if ((c = channel_lookup(id)) == NULL)
1030 packet_disconnect("server_input_channel_req: "
1031 "unknown channel %d", id);
1032 if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
1033 success = session_input_channel_req(c, rtype);
1034 if (reply) {
1035 packet_start(success ?
1036 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1037 packet_put_int(c->remote_id);
1038 packet_send();
1039 }
1040 xfree(rtype);
1041}
Damien Miller0bc1bd82000-11-13 22:57:25 +11001042
Ben Lindstrombba81212001-06-25 05:01:22 +00001043static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001044server_init_dispatch_20(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10001045{
1046 debug("server_init_dispatch_20");
1047 dispatch_init(&dispatch_protocol_error);
1048 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1049 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1050 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1051 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1052 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1053 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1054 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
Damien Millerc7ef63d2002-02-05 12:21:42 +11001055 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
Damien Millerefb4afe2000-04-12 18:45:05 +10001056 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001057 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
Ben Lindstrom5744dc42001-04-13 23:28:01 +00001058 /* client_alive */
Damien Millerb5820f42003-12-17 16:27:32 +11001059 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1060 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1061 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001062 /* rekeying */
1063 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
Damien Millerefb4afe2000-04-12 18:45:05 +10001064}
Ben Lindstrombba81212001-06-25 05:01:22 +00001065static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001066server_init_dispatch_13(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001067{
1068 debug("server_init_dispatch_13");
1069 dispatch_init(NULL);
1070 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1071 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1072 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1073 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1074 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1075 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1076 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1077 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1078 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1079}
Ben Lindstrombba81212001-06-25 05:01:22 +00001080static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001081server_init_dispatch_15(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001082{
1083 server_init_dispatch_13();
1084 debug("server_init_dispatch_15");
1085 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1086 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1087}
Ben Lindstrombba81212001-06-25 05:01:22 +00001088static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001089server_init_dispatch(void)
Damien Millerb38eff82000-04-01 11:09:21 +10001090{
Damien Millerefb4afe2000-04-12 18:45:05 +10001091 if (compat20)
1092 server_init_dispatch_20();
1093 else if (compat13)
Damien Millerb38eff82000-04-01 11:09:21 +10001094 server_init_dispatch_13();
1095 else
1096 server_init_dispatch_15();
1097}