server.c 18.1 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>

104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122
#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)
	(id_comment simple "char *")

	(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);
}

231 232 233 234
struct fd_callback *
make_server_callback(struct io_backend *b,
		     char *comment,
		     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
{
255 256 257 258
  verbose("Connection died, for reason %d.\n", reason);
  if (reason != CLOSE_EOF)
    werror("Connection died.\n");

Niels Möller's avatar
Niels Möller committed
259 260 261
  return 0;  /* Ignored */
}

262
struct close_callback *make_server_close_handler(void)
Niels Möller's avatar
Niels Möller committed
263
{
264
  NEW(close_callback, c);
Niels Möller's avatar
Niels Möller committed
265 266 267 268 269 270

  c->f = server_die;

  return c;
}

271
/* Session */
272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288
/* 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)

       ; Child process's stdio 
       (in object io_fd)
       (out object io_fd)
       (err object io_fd)))
*/

Niels Möller's avatar
Niels Möller committed
289 290 291 292
/* Recieve channel data */
static int do_recieve(struct ssh_channel *c,
		      int type, struct lsh_string *data)
{
293
  CAST(server_session, closure, c);
Niels Möller's avatar
Niels Möller committed
294 295 296

  /* FIXME: Examine the size of the write buffer, to decide if the
   * recieve window should be adjusted. */
Niels Möller's avatar
Niels Möller committed
297 298 299
  switch(type)
    {
    case CHANNEL_DATA:
Niels Möller's avatar
Niels Möller committed
300
      return A_WRITE(&closure->in->buffer->super, data);
Niels Möller's avatar
Niels Möller committed
301 302 303 304 305 306 307 308 309 310 311 312
    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)
{
313
  CAST(server_session, closure, c);
Niels Möller's avatar
Niels Möller committed
314

Niels Möller's avatar
Niels Möller committed
315 316 317 318 319 320 321
  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
322 323 324 325
  
  return LSH_OK | LSH_GOON;
}

Niels Möller's avatar
Niels Möller committed
326 327 328 329 330 331 332 333 334
static int do_eof(struct ssh_channel *c)
{
  CAST(server_session, closure, c);

  write_buffer_close(closure->in->buffer);

  return LSH_OK | LSH_GOON;
}

335 336 337 338
struct ssh_channel *make_server_session(struct unix_user *user,
					UINT32 max_window,
					struct alist *request_types)
{
339
  NEW(server_session, self);
340 341 342 343

  init_channel(&self->super);

  self->super.max_window = max_window;
Niels Möller's avatar
Niels Möller committed
344 345 346
  /* We don't want to recieve any data before we have forked some
   * process to recieve it. */
  self->super.rec_window_size = 0;
347 348 349 350 351 352 353 354

  /* 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
355 356 357 358

  self->in = NULL;
  self->out = NULL;
  self->err = NULL;
359 360 361 362
  
  return &self->super;
}

363 364 365 366 367 368 369 370 371
/* CLASS:
   (class
     (name open_session)
     (super channel_open)
     (vars
       (user object unix_user)
       (session_requests object alist)))
*/

372 373 374 375 376 377 378 379
#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)
{
380
  CAST(open_session, closure, c);
381 382 383 384 385 386
  
  debug("server.c: do_open_session()\n");
  
  if (!parse_eod(args))
    return 0;
  
Niels Möller's avatar
Niels Möller committed
387 388
  return make_server_session(closure->user, WINDOW_SIZE,
			     closure->session_requests);
389 390 391 392 393
}

struct channel_open *make_open_session(struct unix_user *user,
				       struct alist *session_requests)
{
394
  NEW(open_session, closure);
395 396 397 398 399 400 401 402

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

403 404 405 406 407 408 409 410 411 412 413 414 415 416 417
/* 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.
       ))
*/

418 419 420 421
/* Start an authenticated ssh-connection service */
static struct ssh_service *do_login(struct unix_service *c,
				    struct unix_user *user)
{
422
  CAST(server_connection_service, closure, c);
423 424 425 426 427 428 429 430 431 432 433 434 435 436 437

  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)
{
438
  NEW(server_connection_service, closure);
439 440 441 442 443 444 445 446

  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
447 448 449
struct lsh_string *format_exit_signal(struct ssh_channel *channel,
				      int core, int signal)
{
450 451
  struct lsh_string *msg = ssh_format("Process killed by %lz.\n",
				      strsignal(signal));
Niels Möller's avatar
Niels Möller committed
452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
  
  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);
}
469 470 471 472 473 474 475 476 477

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

Niels Möller's avatar
Niels Möller committed
478 479 480
static void do_exit_shell(struct exit_callback *c, int signaled,
			  int core, int value)
{
481
  CAST(exit_shell, closure, c);
Niels Möller's avatar
Niels Möller committed
482 483 484
  struct server_session *session = closure->session;
  struct ssh_channel *channel = &session->super;
  
485
  CHECK_TYPE(server_session, session);
486 487 488

  /* FIXME: Should we explicitly mark these files for closing?
   * The io-backend should notice EOF anyway. */
489
  close_fd(&session->in->super, 0);
490
#if 0
Niels Möller's avatar
Niels Möller committed
491 492
  close_fd(session->out);
  close_fd(session->err);
493
#endif
Niels Möller's avatar
Niels Möller committed
494 495

#if 0
Niels Möller's avatar
Niels Möller committed
496 497 498 499 500 501 502 503 504 505
  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
506
#endif
Niels Möller's avatar
Niels Möller committed
507

508
  channel->flags |= CHANNEL_CLOSE_AT_EOF;
Niels Möller's avatar
Niels Möller committed
509
  
Niels Möller's avatar
Niels Möller committed
510 511 512
  if (!(channel->flags & CHANNEL_SENT_CLOSE))
    {
      int res = A_WRITE(channel->write,
513 514 515 516 517 518 519 520 521 522 523
		    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
524 525
      /* FIXME: Can we do anything better with the return code than
       * ignore it? */
Niels Möller's avatar
Niels Möller committed
526 527

      (void) res;
Niels Möller's avatar
Niels Möller committed
528 529 530 531 532 533
      return;
    }
}

static struct exit_callback *make_exit_shell(struct server_session *session)
{
534
  NEW(exit_shell, self);
Niels Möller's avatar
Niels Möller committed
535 536 537 538 539 540 541

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

  return &self->super;
}

542 543 544 545 546 547 548 549 550
/* CLASS:
   (class
     (name shell_request)
     (super channel_request)
     (vars
       (backend object io_backend)
       (reap object reap)))
*/

551 552 553 554 555
/* 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
556 557 558 559 560 561 562
  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]);

563
  if (SHUTDOWN(fds[0], SHUT_WR) < 0)
Niels Möller's avatar
Niels Möller committed
564 565 566 567
    {
      werror("shutdown(%d, SEND) failed: %s\n", fds[0], strerror(errno));
      return 0;
    }
568
  if (SHUTDOWN(fds[1], SHUT_RD) < 0)
Niels Möller's avatar
Niels Möller committed
569
    {
570
      werror("shutdown(%d, REC) failed: %s\n", fds[0], strerror(errno));
Niels Möller's avatar
Niels Möller committed
571 572
      return 0;
    }
Niels Möller's avatar
Niels Möller committed
573
  
Niels Möller's avatar
Niels Möller committed
574
  return 1;
575 576 577 578
}

static char *make_env_pair(char *name, struct lsh_string *value)
{
579
  return ssh_format("%lz=%lS%c", name, value, 0)->data;
580 581 582 583
}

static char *make_env_pair_c(char *name, char *value)
{
584
  return ssh_format("%lz=%lz%c", name, value, 0)->data;
585 586 587 588 589 590 591
}

static int do_spawn_shell(struct channel_request *c,
			  struct ssh_channel *channel,
			  int want_reply,
			  struct simple_buffer *args)
{
592
  CAST(shell_request, closure, c);
593 594
  struct server_session *session = (struct server_session *) channel;

Niels Möller's avatar
Niels Möller committed
595 596 597
  int in[2];
  int out[2];
  int err[2];
598

599
  CHECK_TYPE(server_session, session);
600 601 602 603 604 605 606 607

  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
608 609
  /* {in|out|err}[0] is for reading,
   * {in|out|err}[1] for writing. */
610

Niels Möller's avatar
Niels Möller committed
611
  if (make_pipe(in))
612
    {
Niels Möller's avatar
Niels Möller committed
613
      if (make_pipe(out))
614
	{
Niels Möller's avatar
Niels Möller committed
615
	  if (make_pipe(err))
616 617 618 619 620 621 622 623 624 625
	    {
	      pid_t child;
	      
	      switch(child = fork())
		{
		case -1:
		  werror("fork() failed: %s\n", strerror(errno));
		  /* Close and return channel_failure */
		  break; 
		case 0:
626
		  { /* Child */
627 628 629 630 631 632
		    char *shell = session->user->shell->data;
#define MAX_ENV 7
		    char *env[MAX_ENV];
		    char *tz = getenv("TZ");
		    int i = 0;

633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
		    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");
		    
660 661 662 663 664 665 666 667 668 669 670 671 672
		    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);
673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
#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]);

714
#if 1
Niels Möller's avatar
Niels Möller committed
715 716 717 718 719 720 721 722 723 724 725
		    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
726 727 728 729 730 731 732 733 734 735 736 737 738 739
		    /* 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));
740

Niels Möller's avatar
Niels Möller committed
741
		      _exit(EXIT_FAILURE);
742
		    }
743 744 745 746
#undef MAX_ENV
		  }
		default:
		  /* Parent */
Niels Möller's avatar
Niels Möller committed
747 748 749 750 751

		  debug("Parent process\n");

		  REAP(closure->reap, child, make_exit_shell(session));
		  
752
		  /* Close the child's fd:s */
Niels Möller's avatar
Niels Möller committed
753 754
		  close(in[0]);
		  close(out[1]);
Niels Möller's avatar
Niels Möller committed
755
		  close(err[1]);
756

Niels Möller's avatar
Niels Möller committed
757
		  session->in
Niels Möller's avatar
Niels Möller committed
758
		    = io_write(closure->backend, in[1],
Niels Möller's avatar
Niels Möller committed
759 760
				SSH_MAX_PACKET,
				/* FIXME: Use a proper close callback */
Niels Möller's avatar
Niels Möller committed
761
				make_channel_close(channel));
Niels Möller's avatar
Niels Möller committed
762 763 764 765 766 767 768 769 770 771 772
		  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
773
		  channel->eof = do_eof;
Niels Möller's avatar
Niels Möller committed
774
		  
775
		  session->running = 1;
Niels Möller's avatar
Niels Möller committed
776 777 778 779 780 781

		  return (want_reply
			  ? A_WRITE(channel->write,
				    format_channel_success(channel
							   ->channel_number))
			  : 0) | LSH_CHANNEL_READY_REC;
782
		}
Niels Möller's avatar
Niels Möller committed
783 784
	      close(err[0]);
	      close(err[1]);
785
	    }
Niels Möller's avatar
Niels Möller committed
786 787
	  close(out[0]);
	  close(out[1]);
788
	}
Niels Möller's avatar
Niels Möller committed
789 790
      close(in[0]);
      close(in[1]);
791 792 793 794 795 796 797
    }
 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
798 799
struct channel_request *make_shell_handler(struct io_backend *backend,
					   struct reap *reap)
800
{
801
  NEW(shell_request, closure);
802 803

  closure->super.handler = do_spawn_shell;
Niels Möller's avatar
Niels Möller committed
804
  closure->backend = backend;
Niels Möller's avatar
Niels Möller committed
805
  closure->reap = reap;
Niels Möller's avatar
Niels Möller committed
806
  
807 808 809
  return &closure->super;
}