server.c 18.4 KB
Newer Older
Niels Möller's avatar
Niels Möller committed
1 2
/* server.c
 *
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
 *
 *
 * $Id$ */

/* lsh, an implementation of the ssh protocol
 *
 * Copyright (C) 1998 Niels Mller
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Niels Möller's avatar
Niels Möller committed
24 25 26 27 28
 */

#include "server.h"

#include "abstract_io.h"
29
#include "channel.h"
30
#include "connection.h"
Niels Möller's avatar
Niels Möller committed
31 32
#include "debug.h"
#include "format.h"
33 34 35
#include "keyexchange.h"
#include "read_line.h"
#include "read_packet.h"
Niels Möller's avatar
Niels Möller committed
36
#include "reaper.h"
37
#include "ssh.h"
Niels Möller's avatar
Niels Möller committed
38
#include "translate_signal.h"
Niels Möller's avatar
Niels Möller committed
39
#include "unpad.h"
40
#include "version.h"
Niels Möller's avatar
Niels Möller committed
41 42 43
#include "werror.h"
#include "xalloc.h"

Niels Möller's avatar
Niels Möller committed
44 45 46 47
#ifndef _GNU_SOURCE
#warning _GNU_SOURCE undefined
#endif

48 49 50 51 52 53 54
#include <assert.h>
#include <string.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/socket.h>

55 56 57 58 59
/* Socket workround */
#ifndef SHUTDOWN_WORKS_WITH_UNIX_SOCKETS

/* There's an how++ missing in the af_unix shutdown implementation of
 * some linux versions. Try an ugly workaround. */
60 61 62 63 64 65
#ifdef linux

/* From src/linux/include/net/sock.h */
#define RCV_SHUTDOWN	1
#define SEND_SHUTDOWN	2

66 67 68 69
#undef SHUT_RD
#undef SHUT_WR
#undef SHUT_RD_WR

70 71 72
#define SHUT_RD RCV_SHUTDOWN
#define SHUT_WR SEND_SHUTDOWN
#define SHUT_RD_WR (RCV_SHUTDOWN | SEND_SHUTDOWN)
73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

#else /* !linux */

/* Don't know how to work around the broken shutdown(). So disable it
 * completely. */

#define SHUTDOWN(fd, how) 0

#endif /* !linux */
#endif /* !SHUTDOWN_WORKS_WITH_UNIX_SOCKETS */

#ifndef SHUTDOWN
#define SHUTDOWN(fd, how) (shutdown((fd), (how)))
#endif

#ifndef SHUT_RD
#define SHUT_RD 0
#endif

#ifndef SHUT_WR
#define SHUT_WR 1
#endif

#ifndef SHUT_RD_WR
#define SHUT_RD_WR 2
#endif
99

Niels Möller's avatar
Niels Möller committed
100 101 102 103
/* For debug */
#include <signal.h>
#include <unistd.h>

104 105 106 107 108 109 110 111 112 113 114 115 116
#include "server.c.x"

/* CLASS:
   (class
     (name server_callback)
     (super fd_callback)
     (vars
       (backend object io_backend)

        (secret object signer) ; Secret key
	(host_key string)      ; Public key 

	(block_size simple UINT32)
117
	(id_comment simple "const char *")
118 119 120 121 122

	(random object randomness)
	(init object make_kexinit)
	(kexinit_handler object packet_handler)))
*/
123

Niels Möller's avatar
Niels Möller committed
124
static int server_initiate(struct fd_callback **c,
Niels Möller's avatar
Niels Möller committed
125 126
			   int fd)
{
Niels Möller's avatar
Niels Möller committed
127 128
  struct server_callback *closure = (struct server_callback *) *c;
  
129 130 131
  struct ssh_connection *connection
    = make_ssh_connection(closure->kexinit_handler);

Niels Möller's avatar
Niels Möller committed
132 133
  int res;
  
134
  verbose("server_initiate()\n");
Niels Möller's avatar
Niels Möller committed
135 136 137 138 139 140 141 142

  connection_init_io(connection,
		     io_read_write(closure->backend, fd,
				   make_server_read_line(connection),
				   closure->block_size,
				   make_server_close_handler()),
		     closure->random);

Niels Möller's avatar
Niels Möller committed
143 144
  
  connection->server_version
Niels Möller's avatar
Niels Möller committed
145
    = ssh_format("SSH-%lz-%lz %lz",
Niels Möller's avatar
Niels Möller committed
146 147 148
		 PROTOCOL_VERSION,
		 SOFTWARE_SERVER_VERSION,
		 closure->id_comment);
Niels Möller's avatar
Niels Möller committed
149

Niels Möller's avatar
Niels Möller committed
150 151
  res = A_WRITE(connection->raw,
		 ssh_format("%lS\r\n", connection->server_version));
152
  if (LSH_CLOSEDP(res))
Niels Möller's avatar
Niels Möller committed
153 154
    return res;

155 156 157
  return res | initiate_keyexchange(connection, CONNECTION_SERVER,
				    MAKE_KEXINIT(closure->init),
				    NULL);
Niels Möller's avatar
Niels Möller committed
158 159
}

160 161 162 163 164 165 166 167
/* CLASS:
   (class
     (name server_line_handler)
     (super line_handler)
     (vars
       (connection object ssh_connection)))
*/

Niels Möller's avatar
Niels Möller committed
168
static struct read_handler *do_line(struct line_handler **h,
Niels Möller's avatar
Niels Möller committed
169 170 171
				    UINT32 length,
				    UINT8 *line)
{
172
  CAST(server_line_handler, closure, *h);
Niels Möller's avatar
Niels Möller committed
173
  
Niels Möller's avatar
Niels Möller committed
174 175 176 177 178
  if ( (length >= 4) && !memcmp(line, "SSH-", 4))
    {
      /* Parse and remember format string */
      if ((length >= 8) && !memcmp(line + 4, "2.0-", 4))
	{
Niels Möller's avatar
Niels Möller committed
179 180 181
	  struct read_handler *new = make_read_packet
	    (make_packet_unpad
	     (make_packet_debug(&closure->connection->super,
182
				"recieved")),
Niels Möller's avatar
Niels Möller committed
183
	     closure->connection);
Niels Möller's avatar
Niels Möller committed
184 185
	  
	  closure->connection->client_version
Niels Möller's avatar
Niels Möller committed
186
	    = ssh_format("%ls", length, line);
Niels Möller's avatar
Niels Möller committed
187

Niels Möller's avatar
Niels Möller committed
188 189 190 191 192
	  verbose("Client version: ");
	  verbose_safe(closure->connection->client_version->length,
		       closure->connection->client_version->data);
	  verbose("\n");
	  
Niels Möller's avatar
Niels Möller committed
193
	  /* FIXME: Cleanup properly. */
194
	  KILL(closure);
Niels Möller's avatar
Niels Möller committed
195 196 197 198 199 200 201 202 203

	  return new;
	}
      else
	{
	  werror("Unsupported protocol version: ");
	  werror_safe(length, line);
	  werror("\n");

Niels Möller's avatar
Niels Möller committed
204
	  /* FIXME: Clean up properly */
205
	  KILL(closure);
Niels Möller's avatar
Niels Möller committed
206 207
	  *h = 0;
		  
Niels Möller's avatar
Niels Möller committed
208 209 210 211 212 213 214 215 216 217 218 219
	  return 0;
	}
    }
  else
    {
      /* Display line */
      werror_safe(length, line);

      /* Read next line */
      return 0;
    }
}
Niels Möller's avatar
Niels Möller committed
220

Niels Möller's avatar
Niels Möller committed
221
struct read_handler *make_server_read_line(struct ssh_connection *c)
Niels Möller's avatar
Niels Möller committed
222
{
223
  NEW(server_line_handler, closure);
Niels Möller's avatar
Niels Möller committed
224

Niels Möller's avatar
Niels Möller committed
225
  closure->super.handler = do_line;
Niels Möller's avatar
Niels Möller committed
226
  closure->connection = c;
Niels Möller's avatar
Niels Möller committed
227 228 229 230
  
  return make_read_line(&closure->super);
}

231 232
struct fd_callback *
make_server_callback(struct io_backend *b,
233
		     const char *comment,
234
		     UINT32 block_size,
Niels Möller's avatar
Niels Möller committed
235 236
		     struct randomness *random,
		     struct make_kexinit *init,
237
		     struct packet_handler *kexinit_handler)
Niels Möller's avatar
Niels Möller committed
238
{
239
  NEW(server_callback, connected);
Niels Möller's avatar
Niels Möller committed
240 241 242 243 244

  connected->super.f = server_initiate;
  connected->backend = b;
  connected->block_size = block_size;
  connected->id_comment = comment;
245

Niels Möller's avatar
Niels Möller committed
246 247
  connected->random = random;  
  connected->init = init;
248
  connected->kexinit_handler = kexinit_handler;
Niels Möller's avatar
Niels Möller committed
249 250 251 252
  
  return &connected->super;
}

253
static int server_die(struct close_callback *closure, int reason)
Niels Möller's avatar
Niels Möller committed
254
{
255
  /* FIXME: If any processes are running, they should be killed now. */
256 257 258 259
  verbose("Connection died, for reason %d.\n", reason);
  if (reason != CLOSE_EOF)
    werror("Connection died.\n");

Niels Möller's avatar
Niels Möller committed
260 261 262
  return 0;  /* Ignored */
}

263
struct close_callback *make_server_close_handler(void)
Niels Möller's avatar
Niels Möller committed
264
{
265
  NEW(close_callback, c);
Niels Möller's avatar
Niels Möller committed
266 267 268 269 270 271

  c->f = server_die;

  return c;
}

272
/* Session */
273 274 275 276 277 278 279 280 281 282
/* CLASS:
   (class
     (name server_session)
     (super ssh_channel)
     (vars
       ; User information
       (user object unix_user)

       ; Non-zero if a shell or command has been started. 
       (running simple int)
283 284
       ; FIXME: We need the pid as well, to be able to kill
       ; the process if the channel or connection is closed.
285 286 287 288 289 290
       ; Child process's stdio 
       (in object io_fd)
       (out object io_fd)
       (err object io_fd)))
*/

Niels Möller's avatar
Niels Möller committed
291 292 293 294
/* Recieve channel data */
static int do_recieve(struct ssh_channel *c,
		      int type, struct lsh_string *data)
{
295
  CAST(server_session, closure, c);
Niels Möller's avatar
Niels Möller committed
296 297 298

  /* FIXME: Examine the size of the write buffer, to decide if the
   * recieve window should be adjusted. */
Niels Möller's avatar
Niels Möller committed
299 300 301
  switch(type)
    {
    case CHANNEL_DATA:
Niels Möller's avatar
Niels Möller committed
302
      return A_WRITE(&closure->in->buffer->super, data);
Niels Möller's avatar
Niels Möller committed
303 304 305 306 307 308 309 310 311 312 313 314
    case CHANNEL_STDERR_DATA:
      werror("Ignoring unexpected stderr data.\n");
      lsh_string_free(data);
      return LSH_OK | LSH_GOON;
    default:
      fatal("Internal error!\n");
    }
}

/* We may send more data */
static int do_send(struct ssh_channel *c)
{
315
  CAST(server_session, closure, c);
Niels Möller's avatar
Niels Möller committed
316

Niels Möller's avatar
Niels Möller committed
317 318 319 320 321 322 323
  assert(closure->out->super.read);
  assert(closure->out->handler);
  assert(closure->err->super.read);
  assert(closure->err->handler);
  
  closure->out->super.want_read = 1;
  closure->err->super.want_read = 1;
Niels Möller's avatar
Niels Möller committed
324 325 326 327
  
  return LSH_OK | LSH_GOON;
}

Niels Möller's avatar
Niels Möller committed
328 329 330 331 332 333 334 335 336
static int do_eof(struct ssh_channel *c)
{
  CAST(server_session, closure, c);

  write_buffer_close(closure->in->buffer);

  return LSH_OK | LSH_GOON;
}

337 338 339 340
struct ssh_channel *make_server_session(struct unix_user *user,
					UINT32 max_window,
					struct alist *request_types)
{
341
  NEW(server_session, self);
342 343 344 345

  init_channel(&self->super);

  self->super.max_window = max_window;
Niels Möller's avatar
Niels Möller committed
346 347 348
  /* We don't want to recieve any data before we have forked some
   * process to recieve it. */
  self->super.rec_window_size = 0;
349 350 351 352 353 354 355 356

  /* FIXME: Make maximum packet size configurable. */
  self->super.rec_max_packet = SSH_MAX_PACKET;

  self->super.request_types = request_types;
  self->user = user;

  self->running = 0;
Niels Möller's avatar
Niels Möller committed
357 358 359 360

  self->in = NULL;
  self->out = NULL;
  self->err = NULL;
361 362 363 364
  
  return &self->super;
}

365 366 367 368 369 370 371 372 373
/* CLASS:
   (class
     (name open_session)
     (super channel_open)
     (vars
       (user object unix_user)
       (session_requests object alist)))
*/

374 375 376 377 378 379 380 381
#define WINDOW_SIZE (SSH_MAX_PACKET << 3)

static struct ssh_channel *do_open_session(struct channel_open *c,
					   struct simple_buffer *args,
					   UINT32 *error,
					   char **error_msg,
					   struct lsh_string **data)
{
382
  CAST(open_session, closure, c);
383 384 385 386 387 388
  
  debug("server.c: do_open_session()\n");
  
  if (!parse_eod(args))
    return 0;
  
Niels Möller's avatar
Niels Möller committed
389 390
  return make_server_session(closure->user, WINDOW_SIZE,
			     closure->session_requests);
391 392 393 394 395
}

struct channel_open *make_open_session(struct unix_user *user,
				       struct alist *session_requests)
{
396
  NEW(open_session, closure);
397 398 399 400 401 402 403 404

  closure->super.handler = do_open_session;
  closure->user = user;
  closure->session_requests = session_requests;
  
  return &closure->super;
}

405 406 407 408 409 410 411 412 413 414 415 416 417 418 419
/* CLASS:
   (class
     (name server_connection_service)
     (super unix_service)
     (vars
       (global_requests object alist)

       ; Requests specific to session channels 
       (session_requests object alist)

       ; FIXME: Doesn't support any channel types but "session". This
       ; must be fixed to support for "direct-tcpip" channels.
       ))
*/

420 421 422 423
/* Start an authenticated ssh-connection service */
static struct ssh_service *do_login(struct unix_service *c,
				    struct unix_user *user)
{
424
  CAST(server_connection_service, closure, c);
425 426 427 428 429 430 431 432 433 434 435 436 437 438 439

  debug("server.c: do_login()\n");
  
  return
    make_connection_service(closure->global_requests,
			    make_alist(1, ATOM_SESSION,
				       make_open_session(user,
							 closure->session_requests),
				       -1),
			    NULL);
}

struct unix_service *make_server_session_service(struct alist *global_requests,
						 struct alist *session_requests)
{
440
  NEW(server_connection_service, closure);
441 442 443 444 445 446 447 448

  closure->super.login = do_login;
  closure->global_requests = global_requests;
  closure->session_requests = session_requests;
  
  return &closure->super;
}

Niels Möller's avatar
Niels Möller committed
449 450 451
struct lsh_string *format_exit_signal(struct ssh_channel *channel,
				      int core, int signal)
{
452 453
  struct lsh_string *msg = ssh_format("Process killed by %lz.\n",
				      strsignal(signal));
Niels Möller's avatar
Niels Möller committed
454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470
  
  return format_channel_request(ATOM_EXIT_SIGNAL,
				channel,
				0,
				"%i%c%fS%z",
				signal_local_to_network(signal),
				core,
				msg, "");
}

struct lsh_string *format_exit(struct ssh_channel *channel, int value)
{
  return format_channel_request(ATOM_EXIT_STATUS,
				channel,
				0,
				"%i", value);
}
471 472 473 474 475 476 477 478 479

/* CLASS:
   (class
     (name exit_shell)
     (super exit_callback)
     (vars
       (session object server_session)))
*/

Niels Möller's avatar
Niels Möller committed
480 481 482
static void do_exit_shell(struct exit_callback *c, int signaled,
			  int core, int value)
{
483
  CAST(exit_shell, closure, c);
Niels Möller's avatar
Niels Möller committed
484 485 486
  struct server_session *session = closure->session;
  struct ssh_channel *channel = &session->super;
  
487
  CHECK_TYPE(server_session, session);
488 489 490

  /* FIXME: Should we explicitly mark these files for closing?
   * The io-backend should notice EOF anyway. */
491
  close_fd(&session->in->super, 0);
492
#if 0
Niels Möller's avatar
Niels Möller committed
493 494
  close_fd(session->out);
  close_fd(session->err);
495
#endif
Niels Möller's avatar
Niels Möller committed
496 497

#if 0
Niels Möller's avatar
Niels Möller committed
498 499 500 501 502 503 504 505 506 507
  if (!(channel->flags & CHANNEL_SENT_EOF)
      /* Don't send eof if the process died violently. */
      && !signaled)
    {
      int res = channel_eof(channel);
      if (LSH_CLOSEDP(res))
	/* FIXME: Can we do anything better with the return code than
	 * ignore it? */
	return;
    }
Niels Möller's avatar
Niels Möller committed
508
#endif
Niels Möller's avatar
Niels Möller committed
509

510
  /* FIXME: We shouldn't close until we have both sent and recieved eof. */
511
  channel->flags |= CHANNEL_CLOSE_AT_EOF;
Niels Möller's avatar
Niels Möller committed
512
  
Niels Möller's avatar
Niels Möller committed
513 514 515
  if (!(channel->flags & CHANNEL_SENT_CLOSE))
    {
      int res = A_WRITE(channel->write,
516 517 518 519 520 521 522 523 524 525 526
		    signaled
		    ? format_exit_signal(channel, core, value)
		    : format_exit(channel, value));

      if (!LSH_CLOSEDP(res)
	  && (channel->flags & CHANNEL_SENT_EOF))
	{
	  /* We have sent EOF already, so initiate close */
	  res |= channel_close(channel);
	}

Niels Möller's avatar
Niels Möller committed
527 528
      /* FIXME: Can we do anything better with the return code than
       * ignore it? */
Niels Möller's avatar
Niels Möller committed
529 530

      (void) res;
Niels Möller's avatar
Niels Möller committed
531 532 533 534 535 536
      return;
    }
}

static struct exit_callback *make_exit_shell(struct server_session *session)
{
537
  NEW(exit_shell, self);
Niels Möller's avatar
Niels Möller committed
538 539 540 541 542 543 544

  self->super.exit = do_exit_shell;
  self->session = session;

  return &self->super;
}

545 546 547 548 549 550 551 552 553
/* CLASS:
   (class
     (name shell_request)
     (super channel_request)
     (vars
       (backend object io_backend)
       (reap object reap)))
*/

554 555 556 557 558
/* Creates a one-way socket connection. Returns 1 on successm 0 on
 * failure. fds[0] is for reading, fds[1] for writing (like for the
 * pipe() system call). */
static int make_pipe(int *fds)
{
Niels Möller's avatar
Niels Möller committed
559 560 561 562 563 564 565
  if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0)
    {
      werror("socketpair() failed: %s\n", strerror(errno));
      return 0;
    }
  debug("Created socket pair. Using fd:s %d <-- %d\n", fds[0], fds[1]);

566
  if (SHUTDOWN(fds[0], SHUT_WR) < 0)
Niels Möller's avatar
Niels Möller committed
567 568 569 570
    {
      werror("shutdown(%d, SEND) failed: %s\n", fds[0], strerror(errno));
      return 0;
    }
571
  if (SHUTDOWN(fds[1], SHUT_RD) < 0)
Niels Möller's avatar
Niels Möller committed
572
    {
573
      werror("shutdown(%d, REC) failed: %s\n", fds[0], strerror(errno));
Niels Möller's avatar
Niels Möller committed
574 575
      return 0;
    }
Niels Möller's avatar
Niels Möller committed
576
  
Niels Möller's avatar
Niels Möller committed
577
  return 1;
578 579
}

580
static char *make_env_pair(const char *name, struct lsh_string *value)
581
{
582
  return ssh_format("%lz=%lS%c", name, value, 0)->data;
583 584
}

585
static char *make_env_pair_c(const char *name, char *value)
586
{
587
  return ssh_format("%lz=%lz%c", name, value, 0)->data;
588 589 590 591 592 593 594
}

static int do_spawn_shell(struct channel_request *c,
			  struct ssh_channel *channel,
			  int want_reply,
			  struct simple_buffer *args)
{
595
  CAST(shell_request, closure, c);
596 597
  struct server_session *session = (struct server_session *) channel;

Niels Möller's avatar
Niels Möller committed
598 599 600
  int in[2];
  int out[2];
  int err[2];
601

602
  CHECK_TYPE(server_session, session);
603 604 605 606 607 608 609 610

  if (!parse_eod(args))
    return LSH_FAIL | LSH_DIE;

  if (session->running)
    /* Already spawned a shell or command */
    goto fail;
  
Niels Möller's avatar
Niels Möller committed
611 612
  /* {in|out|err}[0] is for reading,
   * {in|out|err}[1] for writing. */
613

Niels Möller's avatar
Niels Möller committed
614
  if (make_pipe(in))
615
    {
Niels Möller's avatar
Niels Möller committed
616
      if (make_pipe(out))
617
	{
Niels Möller's avatar
Niels Möller committed
618
	  if (make_pipe(err))
619 620 621 622 623 624 625 626 627 628
	    {
	      pid_t child;
	      
	      switch(child = fork())
		{
		case -1:
		  werror("fork() failed: %s\n", strerror(errno));
		  /* Close and return channel_failure */
		  break; 
		case 0:
629
		  { /* Child */
630 631 632 633 634 635
		    char *shell = session->user->shell->data;
#define MAX_ENV 7
		    char *env[MAX_ENV];
		    char *tz = getenv("TZ");
		    int i = 0;

636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662
		    int old_stderr;
		    
		    debug("do_spawn_shell: Child process\n");

		    if (!session->user->shell)
		      {
			werror("No login shell!\n");
			exit(EXIT_FAILURE);
		      }

		    if (getuid() != session->user->uid)
		      if (!change_uid(session->user))
			{
			  werror("Changing uid failed!\n");
			  exit(EXIT_FAILURE);
			}
		    
		    assert(getuid() == session->user->uid);
		    
		    if (!change_dir(session->user))
		      {
			werror("Could not change to home (or root) directory!\n");
			exit(EXIT_FAILURE);
		      }

		    debug("Child: Setting up environment.\n");
		    
663 664 665 666 667 668 669 670 671 672 673 674 675
		    env[i++] = make_env_pair("LOGNAME", session->user->name);
		    env[i++] = make_env_pair("USER", session->user->name);
		    env[i++] = make_env_pair("SHELL", session->user->shell);
		    if (session->user->home)
		      env[i++] = make_env_pair("HOME", session->user->home);
		    if (tz)
		      env[i++] = make_env_pair_c("TZ", tz);

		    /* FIXME: The value of $PATH should not be hard-coded */
		    env[i++] = "PATH=/bin:/usr/bin";
		    env[i++] = NULL;
		    
		    assert(i <= MAX_ENV);
676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716
#undef MAX_ENV

		    debug("Child: Environment:\n");
		    for (i=0; env[i]; i++)
		      debug("Child:   '%s'\n", env[i]);
		    
		    /* Close all descriptors but those used for
		     * communicationg with parent. We rely on the
		     * close-on-exec flag for all fd:s handled by the
		     * backend. */
		    
		    if (dup2(in[0], STDIN_FILENO) < 0)
		      {
			werror("Can't dup stdin!\n");
			exit(EXIT_FAILURE);
		      }
		    close(in[0]);
		    close(in[1]);
		    
		    if (dup2(out[1], STDOUT_FILENO) < 0)
		      {
			werror("Can't dup stdout!\n");
			exit(EXIT_FAILURE);
		      }
		    close(out[0]);
		    close(out[1]);

		    if ((old_stderr = dup(STDERR_FILENO)) < 0)
		      werror("Couldn't safe old file_no.\n");
		    io_set_close_on_exec(old_stderr);

		    debug("Child: Duping stderr (bye).\n");
		    
		    if (dup2(err[1], STDERR_FILENO) < 0)
		      {
			/* Can't write any message to stderr. */ 
			exit(EXIT_FAILURE);
		      }
		    close(err[0]);
		    close(err[1]);

717
#if 1
Niels Möller's avatar
Niels Möller committed
718 719 720 721 722 723 724 725 726 727 728
		    execle(shell, shell, NULL, env);
#else
#define GREETING "Hello world!\n"
		    if (write(STDOUT_FILENO, GREETING, strlen(GREETING)) < 0)
		      _exit(errno);
		    kill(getuid(), SIGSTOP);
		    if (write(STDOUT_FILENO, shell, strlen(shell)) < 0)
		      _exit(125);
		    _exit(126);
#undef GREETING
#endif
729 730 731 732 733 734 735 736 737 738 739 740 741 742
		    /* exec failed! */
		    {
		      int exec_errno = errno;

		      if (dup2(old_stderr, STDERR_FILENO) < 0)
			{
			  /* This is really bad... We can't restore stderr
			   * to report our problems. */
			  char msg[] = "child: execle() failed!\n";
			  write(old_stderr, msg, sizeof(msg));
			}
		      else
			debug("Child: execle() failed (errno = %d): %s\n",
			      exec_errno, strerror(exec_errno));
743

Niels Möller's avatar
Niels Möller committed
744
		      _exit(EXIT_FAILURE);
745
		    }
746 747 748 749
#undef MAX_ENV
		  }
		default:
		  /* Parent */
Niels Möller's avatar
Niels Möller committed
750 751 752 753 754

		  debug("Parent process\n");

		  REAP(closure->reap, child, make_exit_shell(session));
		  
755
		  /* Close the child's fd:s */
Niels Möller's avatar
Niels Möller committed
756 757
		  close(in[0]);
		  close(out[1]);
Niels Möller's avatar
Niels Möller committed
758
		  close(err[1]);
759

Niels Möller's avatar
Niels Möller committed
760
		  session->in
Niels Möller's avatar
Niels Möller committed
761
		    = io_write(closure->backend, in[1],
Niels Möller's avatar
Niels Möller committed
762 763
				SSH_MAX_PACKET,
				/* FIXME: Use a proper close callback */
Niels Möller's avatar
Niels Möller committed
764
				make_channel_close(channel));
Niels Möller's avatar
Niels Möller committed
765 766 767 768 769 770 771 772 773 774 775
		  session->out
		    = io_read(closure->backend, out[0],
			      make_channel_read_data(channel),
			      NULL);
		  session->err
		    = io_read(closure->backend, err[0],
			      make_channel_read_stderr(channel),
			      NULL);

		  channel->recieve = do_recieve;
		  channel->send = do_send;
Niels Möller's avatar
Niels Möller committed
776
		  channel->eof = do_eof;
Niels Möller's avatar
Niels Möller committed
777
		  
778
		  session->running = 1;
Niels Möller's avatar
Niels Möller committed
779 780 781 782 783 784

		  return (want_reply
			  ? A_WRITE(channel->write,
				    format_channel_success(channel
							   ->channel_number))
			  : 0) | LSH_CHANNEL_READY_REC;
785
		}
Niels Möller's avatar
Niels Möller committed
786 787
	      close(err[0]);
	      close(err[1]);
788
	    }
Niels Möller's avatar
Niels Möller committed
789 790
	  close(out[0]);
	  close(out[1]);
791
	}
Niels Möller's avatar
Niels Möller committed
792 793
      close(in[0]);
      close(in[1]);
794 795 796 797 798 799 800
    }
 fail:
  return want_reply
    ? A_WRITE(channel->write, format_channel_failure(channel->channel_number))
    : LSH_OK | LSH_GOON;
}

Niels Möller's avatar
Niels Möller committed
801 802
struct channel_request *make_shell_handler(struct io_backend *backend,
					   struct reap *reap)
803
{
804
  NEW(shell_request, closure);
805 806

  closure->super.handler = do_spawn_shell;
Niels Möller's avatar
Niels Möller committed
807
  closure->backend = backend;
Niels Möller's avatar
Niels Möller committed
808
  closure->reap = reap;
Niels Möller's avatar
Niels Möller committed
809
  
810 811 812
  return &closure->super;
}