session.c

   1 /*
   2  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   3  *                    All rights reserved
   4  *
   5  * As far as I am concerned, the code I have written for this software
   6  * can be used freely for any purpose.  Any derived versions of this
   7  * software must be clearly marked as such, and if the derived work is
   8  * incompatible with the protocol description in the RFC file, it must be
   9  * called by a name other than "ssh" or "Secure Shell".
  10  *
  11  * SSH2 support by Markus Friedl.
  12  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include "includes.h"
  36 RCSID("$OpenBSD: session.c,v 1.96 2001/06/26 16:15:24 dugsong Exp $");
  37
  38 #include "ssh.h"
  39 #include "ssh1.h"
  40 #include "ssh2.h"
  41 #include "xmalloc.h"
  42 #include "sshpty.h"
  43 #include "packet.h"
  44 #include "buffer.h"
  45 #include "mpaux.h"
  46 #include "uidswap.h"
  47 #include "compat.h"
  48 #include "channels.h"
  49 #include "bufaux.h"
  50 #include "auth.h"
  51 #include "auth-options.h"
  52 #include "pathnames.h"
  53 #include "log.h"
  54 #include "servconf.h"
  55 #include "sshlogin.h"
  56 #include "serverloop.h"
  57 #include "canohost.h"
  58 #include "session.h"
  59
  60 #ifdef WITH_IRIX_PROJECT
  61 #include <proj.h>
  62 #endif /* WITH_IRIX_PROJECT */
  63 #ifdef WITH_IRIX_JOBS
  64 #include <sys/resource.h>
  65 #endif
  66 #ifdef WITH_IRIX_AUDIT
  67 #include <sat.h>
  68 #endif /* WITH_IRIX_AUDIT */
  69
  70 #if defined(HAVE_USERSEC_H)
  71 #include <usersec.h>
  72 #endif
  73
  74 #ifdef HAVE_CYGWIN
  75 #include <windows.h>
  76 #include <sys/cygwin.h>
  77 #define is_winnt       (GetVersion() < 0x80000000)
  78 #endif
  79
  80 /* AIX limits */
  81 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  82 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  83 # define S_UCPU_HARD  S_UCPU "_hard"
  84 # define S_UDATA_HARD  S_UDATA "_hard"
  85 # define S_USTACK_HARD  S_USTACK "_hard"
  86 # define S_URSS_HARD  S_URSS "_hard"
  87 # define S_UCORE_HARD  S_UCORE "_hard"
  88 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  89 #endif
  90
  91 #ifdef _AIX
  92 # include <uinfo.h>
  93 #endif
  94
  95 /* types */
  96
  97 #define TTYSZ 64
  98 typedef struct Session Session;
  99 struct Session {
 100         int     used;
 101         int     self;
 102         struct passwd *pw;
 103         Authctxt *authctxt;
 104         pid_t   pid;
 105         /* tty */
 106         char    *term;
 107         int     ptyfd, ttyfd, ptymaster;
 108         int     row, col, xpixel, ypixel;
 109         char    tty[TTYSZ];
 110         /* X11 */
 111         char    *display;
 112         int     screen;
 113         char    *auth_proto;
 114         char    *auth_data;
 115         int     single_connection;
 116         /* proto 2 */
 117         int     chanid;
 118         int     is_subsystem;
 119 };
 120
 121 /* func */
 122
 123 Session *session_new(void);
 124 void  session_set_fds(Session *, int, int, int);
 125 static void   session_pty_cleanup(void *);
 126 void  session_proctitle(Session *);
 127 int   session_setup_x11fwd(Session *);
 128 void  do_exec_pty(Session *, const char *);
 129 void  do_exec_no_pty(Session *, const char *);
 130 void  do_exec(Session *, const char *);
 131 void  do_login(Session *, const char *);
 132 void  do_child(Session *, const char *);
 133 void    do_motd(void);
 134
 135 static void do_authenticated1(Authctxt *);
 136 static void do_authenticated2(Authctxt *);
 137
 138 static void session_close(Session *);
 139 static int session_pty_req(Session *);
 140
 141 /* import */
 142 extern ServerOptions options;
 143 extern char *__progname;
 144 extern int log_stderr;
 145 extern int debug_flag;
 146 extern u_int utmp_len;
 147 extern int startup_pipe;
 148 extern void destroy_sensitive_data(void);
 149
 150 /* original command from peer. */
 151 const char *original_command = NULL;
 152
 153 /* data */
 154 #define MAX_SESSIONS 10
 155 Session sessions[MAX_SESSIONS];
 156
 157 #ifdef WITH_AIXAUTHENTICATE
 158 /* AIX's lastlogin message, set in auth1.c */
 159 char *aixloginmsg;
 160 #endif /* WITH_AIXAUTHENTICATE */
 161
 162 #ifdef HAVE_LOGIN_CAP
 163 static login_cap_t *lc;
 164 #endif
 165
 166 void
 167 do_authenticated(Authctxt *authctxt)
 168 {
 169         /*
 170          * Cancel the alarm we set to limit the time taken for
 171          * authentication.
 172          */
 173         alarm(0);
 174         if (startup_pipe != -1) {
 175                 close(startup_pipe);
 176                 startup_pipe = -1;
 177         }
 178 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 179         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 180                 error("unable to get login class");
 181                 return;
 182         }
 183 #ifdef BSD_AUTH
 184         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 185                 packet_disconnect("Approval failure for %s",
 186                     authctxt->pw->pw_name);
 187         }
 188 #endif
 189 #endif
 190         /* setup the channel layer */
 191         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 192                 channel_permit_all_opens();
 193
 194         if (compat20)
 195                 do_authenticated2(authctxt);
 196         else
 197                 do_authenticated1(authctxt);
 198
 199         /* remove agent socket */
 200         if (auth_get_socket_name())
 201                 auth_sock_cleanup_proc(authctxt->pw);
 202 #ifdef KRB4
 203         if (options.kerberos_ticket_cleanup)
 204                 krb4_cleanup_proc(authctxt);
 205 #endif
 206 #ifdef KRB5
 207         if (options.kerberos_ticket_cleanup)
 208                 krb5_cleanup_proc(authctxt);
 209 #endif
 210 }
 211
 212 /*
 213  * Prepares for an interactive session.  This is called after the user has
 214  * been successfully authenticated.  During this message exchange, pseudo
 215  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 216  * are requested, etc.
 217  */
 218 static void
 219 do_authenticated1(Authctxt *authctxt)
 220 {
 221         Session *s;
 222         char *command;
 223         int success, type, plen, screen_flag;
 224         int compression_level = 0, enable_compression_after_reply = 0;
 225         u_int proto_len, data_len, dlen;
 226
 227         s = session_new();
 228         s->authctxt = authctxt;
 229         s->pw = authctxt->pw;
 230
 231         /*
 232          * We stay in this loop until the client requests to execute a shell
 233          * or a command.
 234          */
 235         for (;;) {
 236                 success = 0;
 237
 238                 /* Get a packet from the client. */
 239                 type = packet_read(&plen);
 240
 241                 /* Process the packet. */
 242                 switch (type) {
 243                 case SSH_CMSG_REQUEST_COMPRESSION:
 244                         packet_integrity_check(plen, 4, type);
 245                         compression_level = packet_get_int();
 246                         if (compression_level < 1 || compression_level > 9) {
 247                                 packet_send_debug("Received illegal compression level %d.",
 248                                      compression_level);
 249                                 break;
 250                         }
 251                         /* Enable compression after we have responded with SUCCESS. */
 252                         enable_compression_after_reply = 1;
 253                         success = 1;
 254                         break;
 255
 256                 case SSH_CMSG_REQUEST_PTY:
 257                         success = session_pty_req(s);
 258                         break;
 259
 260                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 261                         s->auth_proto = packet_get_string(&proto_len);
 262                         s->auth_data = packet_get_string(&data_len);
 263
 264                         screen_flag = packet_get_protocol_flags() &
 265                             SSH_PROTOFLAG_SCREEN_NUMBER;
 266                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 267
 268                         if (packet_remaining() == 4) {
 269                                 if (!screen_flag)
 270                                         debug2("Buggy client: "
 271                                             "X11 screen flag missing");
 272                                 s->screen = packet_get_int();
 273                         } else {
 274                                 s->screen = 0;
 275                         }
 276                         packet_done();
 277                         success = session_setup_x11fwd(s);
 278                         if (!success) {
 279                                 xfree(s->auth_proto);
 280                                 xfree(s->auth_data);
 281                                 s->auth_proto = NULL;
 282                                 s->auth_data = NULL;
 283                         }
 284                         break;
 285
 286                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 287                         if (no_agent_forwarding_flag || compat13) {
 288                                 debug("Authentication agent forwarding not permitted for this authentication.");
 289                                 break;
 290                         }
 291                         debug("Received authentication agent forwarding request.");
 292                         success = auth_input_request_forwarding(s->pw);
 293                         break;
 294
 295                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 296                         if (no_port_forwarding_flag) {
 297                                 debug("Port forwarding not permitted for this authentication.");
 298                                 break;
 299                         }
 300                         if (!options.allow_tcp_forwarding) {
 301                                 debug("Port forwarding not permitted.");
 302                                 break;
 303                         }
 304                         debug("Received TCP/IP port forwarding request.");
 305                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 306                         success = 1;
 307                         break;
 308
 309                 case SSH_CMSG_MAX_PACKET_SIZE:
 310                         if (packet_set_maxsize(packet_get_int()) > 0)
 311                                 success = 1;
 312                         break;
 313
 314 #if defined(AFS) || defined(KRB5)
 315                 case SSH_CMSG_HAVE_KERBEROS_TGT:
 316                         if (!options.kerberos_tgt_passing) {
 317                                 verbose("Kerberos TGT passing disabled.");
 318                         } else {
 319                                 char *kdata = packet_get_string(&dlen);
 320                                 packet_integrity_check(plen, 4 + dlen, type);
 321
 322                                 /* XXX - 0x41, see creds_to_radix version */
 323                                 if (kdata[0] != 0x41) {
 324 #ifdef KRB5
 325                                         krb5_data tgt;
 326                                         tgt.data = kdata;
 327                                         tgt.length = dlen;
 328
 329                                         if (auth_krb5_tgt(s->authctxt, &tgt))
 330                                                 success = 1;
 331                                         else
 332                                                 verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
 333 #endif /* KRB5 */
 334                                 } else {
 335 #ifdef AFS
 336                                         if (auth_krb4_tgt(s->authctxt, kdata))
 337                                                 success = 1;
 338                                         else
 339                                                 verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
 340 #endif /* AFS */
 341                                 }
 342                                 xfree(kdata);
 343                         }
 344                         break;
 345 #endif /* AFS || KRB5 */
 346
 347 #ifdef AFS
 348                 case SSH_CMSG_HAVE_AFS_TOKEN:
 349                         if (!options.afs_token_passing || !k_hasafs()) {
 350                                 verbose("AFS token passing disabled.");
 351                         } else {
 352                                 /* Accept AFS token. */
 353                                 char *token = packet_get_string(&dlen);
 354                                 packet_integrity_check(plen, 4 + dlen, type);
 355
 356                                 if (auth_afs_token(s->authctxt, token))
 357                                         success = 1;
 358                                 else
 359                                         verbose("AFS token refused for %.100s",
 360                                             s->authctxt->user);
 361                                 xfree(token);
 362                         }
 363                         break;
 364 #endif /* AFS */
 365
 366                 case SSH_CMSG_EXEC_SHELL:
 367                 case SSH_CMSG_EXEC_CMD:
 368                         if (type == SSH_CMSG_EXEC_CMD) {
 369                                 command = packet_get_string(&dlen);
 370                                 debug("Exec command '%.500s'", command);
 371                                 do_exec(s, command);
 372                                 xfree(command);
 373                         } else {
 374                                 do_exec(s, NULL);
 375                         }
 376                         packet_done();
 377                         session_close(s);
 378                         return;
 379
 380                 default:
 381                         /*
 382                          * Any unknown messages in this phase are ignored,
 383                          * and a failure message is returned.
 384                          */
 385                         log("Unknown packet type received after authentication: %d", type);
 386                 }
 387                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 388                 packet_send();
 389                 packet_write_wait();
 390
 391                 /* Enable compression now that we have replied if appropriate. */
 392                 if (enable_compression_after_reply) {
 393                         enable_compression_after_reply = 0;
 394                         packet_start_compression(compression_level);
 395                 }
 396         }
 397 }
 398
 399 /*
 400  * This is called to fork and execute a command when we have no tty.  This
 401  * will call do_child from the child, and server_loop from the parent after
 402  * setting up file descriptors and such.
 403  */
 404 void
 405 do_exec_no_pty(Session *s, const char *command)
 406 {
 407         int pid;
 408
 409 #ifdef USE_PIPES
 410         int pin[2], pout[2], perr[2];
 411         /* Allocate pipes for communicating with the program. */
 412         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 413                 packet_disconnect("Could not create pipes: %.100s",
 414                                   strerror(errno));
 415 #else /* USE_PIPES */
 416         int inout[2], err[2];
 417         /* Uses socket pairs to communicate with the program. */
 418         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 419             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 420                 packet_disconnect("Could not create socket pairs: %.100s",
 421                                   strerror(errno));
 422 #endif /* USE_PIPES */
 423         if (s == NULL)
 424                 fatal("do_exec_no_pty: no session");
 425
 426         session_proctitle(s);
 427
 428 #if defined(USE_PAM)
 429         do_pam_session(s->pw->pw_name, NULL);
 430         do_pam_setcred(1);
 431 #endif /* USE_PAM */
 432
 433         /* Fork the child. */
 434         if ((pid = fork()) == 0) {
 435                 /* Child.  Reinitialize the log since the pid has changed. */
 436                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 437
 438                 /*
 439                  * Create a new session and process group since the 4.4BSD
 440                  * setlogin() affects the entire process group.
 441                  */
 442                 if (setsid() < 0)
 443                         error("setsid failed: %.100s", strerror(errno));
 444
 445 #ifdef USE_PIPES
 446                 /*
 447                  * Redirect stdin.  We close the parent side of the socket
 448                  * pair, and make the child side the standard input.
 449                  */
 450                 close(pin[1]);
 451                 if (dup2(pin[0], 0) < 0)
 452                         perror("dup2 stdin");
 453                 close(pin[0]);
 454
 455                 /* Redirect stdout. */
 456                 close(pout[0]);
 457                 if (dup2(pout[1], 1) < 0)
 458                         perror("dup2 stdout");
 459                 close(pout[1]);
 460
 461                 /* Redirect stderr. */
 462                 close(perr[0]);
 463                 if (dup2(perr[1], 2) < 0)
 464                         perror("dup2 stderr");
 465                 close(perr[1]);
 466 #else /* USE_PIPES */
 467                 /*
 468                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 469                  * use the same socket, as some programs (particularly rdist)
 470                  * seem to depend on it.
 471                  */
 472                 close(inout[1]);
 473                 close(err[1]);
 474                 if (dup2(inout[0], 0) < 0)      /* stdin */
 475                         perror("dup2 stdin");
 476                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 477                         perror("dup2 stdout");
 478                 if (dup2(err[0], 2) < 0)        /* stderr */
 479                         perror("dup2 stderr");
 480 #endif /* USE_PIPES */
 481
 482                 /* Do processing for the child (exec command etc). */
 483                 do_child(s, command);
 484                 /* NOTREACHED */
 485         }
 486 #ifdef HAVE_CYGWIN
 487         if (is_winnt)
 488                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 489 #endif
 490         if (pid < 0)
 491                 packet_disconnect("fork failed: %.100s", strerror(errno));
 492         s->pid = pid;
 493         /* Set interactive/non-interactive mode. */
 494         packet_set_interactive(s->display != NULL);
 495 #ifdef USE_PIPES
 496         /* We are the parent.  Close the child sides of the pipes. */
 497         close(pin[0]);
 498         close(pout[1]);
 499         close(perr[1]);
 500
 501         if (compat20) {
 502                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 503         } else {
 504                 /* Enter the interactive session. */
 505                 server_loop(pid, pin[1], pout[0], perr[0]);
 506                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 507         }
 508 #else /* USE_PIPES */
 509         /* We are the parent.  Close the child sides of the socket pairs. */
 510         close(inout[0]);
 511         close(err[0]);
 512
 513         /*
 514          * Enter the interactive session.  Note: server_loop must be able to
 515          * handle the case that fdin and fdout are the same.
 516          */
 517         if (compat20) {
 518                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 519         } else {
 520                 server_loop(pid, inout[1], inout[1], err[1]);
 521                 /* server_loop has closed inout[1] and err[1]. */
 522         }
 523 #endif /* USE_PIPES */
 524 }
 525
 526 /*
 527  * This is called to fork and execute a command when we have a tty.  This
 528  * will call do_child from the child, and server_loop from the parent after
 529  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 530  * lastlog, and other such operations.
 531  */
 532 void
 533 do_exec_pty(Session *s, const char *command)
 534 {
 535         int fdout, ptyfd, ttyfd, ptymaster;
 536         pid_t pid;
 537
 538         if (s == NULL)
 539                 fatal("do_exec_pty: no session");
 540         ptyfd = s->ptyfd;
 541         ttyfd = s->ttyfd;
 542
 543 #if defined(USE_PAM)
 544         do_pam_session(s->pw->pw_name, s->tty);
 545         do_pam_setcred(1);
 546 #endif
 547
 548         /* Fork the child. */
 549         if ((pid = fork()) == 0) {
 550                 /* Child.  Reinitialize the log because the pid has changed. */
 551                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 552
 553                 /* Close the master side of the pseudo tty. */
 554                 close(ptyfd);
 555
 556                 /* Make the pseudo tty our controlling tty. */
 557                 pty_make_controlling_tty(&ttyfd, s->tty);
 558
 559                 /* Redirect stdin from the pseudo tty. */
 560                 if (dup2(ttyfd, fileno(stdin)) < 0)
 561                         error("dup2 stdin failed: %.100s", strerror(errno));
 562
 563                 /* Redirect stdout to the pseudo tty. */
 564                 if (dup2(ttyfd, fileno(stdout)) < 0)
 565                         error("dup2 stdin failed: %.100s", strerror(errno));
 566
 567                 /* Redirect stderr to the pseudo tty. */
 568                 if (dup2(ttyfd, fileno(stderr)) < 0)
 569                         error("dup2 stdin failed: %.100s", strerror(errno));
 570
 571                 /* Close the extra descriptor for the pseudo tty. */
 572                 close(ttyfd);
 573
 574                 /* record login, etc. similar to login(1) */
 575 #ifndef HAVE_OSF_SIA
 576                 if (!(options.use_login && command == NULL))
 577                         do_login(s, command);
 578 # ifdef LOGIN_NEEDS_UTMPX
 579                 else
 580                         do_pre_login(s);
 581 # endif
 582 #endif
 583
 584                 /* Do common processing for the child, such as execing the command. */
 585                 do_child(s, command);
 586                 /* NOTREACHED */
 587         }
 588 #ifdef HAVE_CYGWIN
 589         if (is_winnt)
 590                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 591 #endif
 592         if (pid < 0)
 593                 packet_disconnect("fork failed: %.100s", strerror(errno));
 594         s->pid = pid;
 595
 596         /* Parent.  Close the slave side of the pseudo tty. */
 597         close(ttyfd);
 598
 599         /*
 600          * Create another descriptor of the pty master side for use as the
 601          * standard input.  We could use the original descriptor, but this
 602          * simplifies code in server_loop.  The descriptor is bidirectional.
 603          */
 604         fdout = dup(ptyfd);
 605         if (fdout < 0)
 606                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 607
 608         /* we keep a reference to the pty master */
 609         ptymaster = dup(ptyfd);
 610         if (ptymaster < 0)
 611                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 612         s->ptymaster = ptymaster;
 613
 614         /* Enter interactive session. */
 615         packet_set_interactive(1);
 616         if (compat20) {
 617                 session_set_fds(s, ptyfd, fdout, -1);
 618         } else {
 619                 server_loop(pid, ptyfd, fdout, -1);
 620                 /* server_loop _has_ closed ptyfd and fdout. */
 621         }
 622 }
 623
 624 #ifdef LOGIN_NEEDS_UTMPX
 625 void
 626 do_pre_login(Session *s)
 627 {
 628         socklen_t fromlen;
 629         struct sockaddr_storage from;
 630         pid_t pid = getpid();
 631
 632         /*
 633          * Get IP address of client. If the connection is not a socket, let
 634          * the address be 0.0.0.0.
 635          */
 636         memset(&from, 0, sizeof(from));
 637         if (packet_connection_is_on_socket()) {
 638                 fromlen = sizeof(from);
 639                 if (getpeername(packet_get_connection_in(),
 640                      (struct sockaddr *) & from, &fromlen) < 0) {
 641                         debug("getpeername: %.100s", strerror(errno));
 642                         fatal_cleanup();
 643                 }
 644         }
 645
 646         record_utmp_only(pid, s->tty, s->pw->pw_name,
 647             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 648             (struct sockaddr *)&from);
 649 }
 650 #endif
 651
 652 /*
 653  * This is called to fork and execute a command.  If another command is
 654  * to be forced, execute that instead.
 655  */
 656 void
 657 do_exec(Session *s, const char *command)
 658 {
 659         if (forced_command) {
 660                 original_command = command;
 661                 command = forced_command;
 662                 debug("Forced command '%.900s'", command);
 663         }
 664
 665         if (s->ttyfd != -1)
 666                 do_exec_pty(s, command);
 667         else
 668                 do_exec_no_pty(s, command);
 669
 670         original_command = NULL;
 671 }
 672
 673 /*
 674  * Check for quiet login, either .hushlogin or command given.
 675  */
 676 static int
 677 check_quietlogin(Session *s, const char *command)
 678 {
 679         char buf[256];
 680         struct passwd *pw = s->pw;
 681         struct stat st;
 682
 683         /* Return 1 if .hushlogin exists or a command given. */
 684         if (command != NULL)
 685                 return 1;
 686         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 687 #ifdef HAVE_LOGIN_CAP
 688         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 689                 return 1;
 690 #else
 691         if (stat(buf, &st) >= 0)
 692                 return 1;
 693 #endif
 694         return 0;
 695 }
 696
 697 /* administrative, login(1)-like work */
 698 void
 699 do_login(Session *s, const char *command)
 700 {
 701         char *time_string;
 702         char hostname[MAXHOSTNAMELEN];
 703         socklen_t fromlen;
 704         struct sockaddr_storage from;
 705         time_t last_login_time;
 706         struct passwd * pw = s->pw;
 707         pid_t pid = getpid();
 708
 709         /*
 710          * Get IP address of client. If the connection is not a socket, let
 711          * the address be 0.0.0.0.
 712          */
 713         memset(&from, 0, sizeof(from));
 714         if (packet_connection_is_on_socket()) {
 715                 fromlen = sizeof(from);
 716                 if (getpeername(packet_get_connection_in(),
 717                      (struct sockaddr *) & from, &fromlen) < 0) {
 718                         debug("getpeername: %.100s", strerror(errno));
 719                         fatal_cleanup();
 720                 }
 721         }
 722
 723         /* Get the time and hostname when the user last logged in. */
 724         if (options.print_lastlog) {
 725                 hostname[0] = '\0';
 726                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 727                     hostname, sizeof(hostname));
 728         }
 729
 730         /* Record that there was a login on that tty from the remote host. */
 731         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 732             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 733             (struct sockaddr *)&from);
 734
 735 #ifdef USE_PAM
 736         /*
 737          * If password change is needed, do it now.
 738          * This needs to occur before the ~/.hushlogin check.
 739          */
 740         if (is_pam_password_change_required()) {
 741                 print_pam_messages();
 742                 do_pam_chauthtok();
 743         }
 744 #endif
 745
 746         if (check_quietlogin(s, command))
 747                 return;
 748
 749 #ifdef USE_PAM
 750         if (!is_pam_password_change_required())
 751                 print_pam_messages();
 752 #endif /* USE_PAM */
 753 #ifdef WITH_AIXAUTHENTICATE
 754         if (aixloginmsg && *aixloginmsg)
 755                 printf("%s\n", aixloginmsg);
 756 #endif /* WITH_AIXAUTHENTICATE */
 757
 758         if (options.print_lastlog && last_login_time != 0) {
 759                 time_string = ctime(&last_login_time);
 760                 if (strchr(time_string, '\n'))
 761                         *strchr(time_string, '\n') = 0;
 762                 if (strcmp(hostname, "") == 0)
 763                         printf("Last login: %s\r\n", time_string);
 764                 else
 765                         printf("Last login: %s from %s\r\n", time_string, hostname);
 766         }
 767
 768         do_motd();
 769 }
 770
 771 /*
 772  * Display the message of the day.
 773  */
 774 void
 775 do_motd(void)
 776 {
 777         FILE *f;
 778         char buf[256];
 779
 780         if (options.print_motd) {
 781 #ifdef HAVE_LOGIN_CAP
 782                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 783                     "/etc/motd"), "r");
 784 #else
 785                 f = fopen("/etc/motd", "r");
 786 #endif
 787                 if (f) {
 788                         while (fgets(buf, sizeof(buf), f))
 789                                 fputs(buf, stdout);
 790                         fclose(f);
 791                 }
 792         }
 793 }
 794
 795 /*
 796  * Sets the value of the given variable in the environment.  If the variable
 797  * already exists, its value is overriden.
 798  */
 799 static void
 800 child_set_env(char ***envp, u_int *envsizep, const char *name,
 801               const char *value)
 802 {
 803         u_int i, namelen;
 804         char **env;
 805
 806         /*
 807          * Find the slot where the value should be stored.  If the variable
 808          * already exists, we reuse the slot; otherwise we append a new slot
 809          * at the end of the array, expanding if necessary.
 810          */
 811         env = *envp;
 812         namelen = strlen(name);
 813         for (i = 0; env[i]; i++)
 814                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 815                         break;
 816         if (env[i]) {
 817                 /* Reuse the slot. */
 818                 xfree(env[i]);
 819         } else {
 820                 /* New variable.  Expand if necessary. */
 821                 if (i >= (*envsizep) - 1) {
 822                         (*envsizep) += 50;
 823                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 824                 }
 825                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 826                 env[i + 1] = NULL;
 827         }
 828
 829         /* Allocate space and format the variable in the appropriate slot. */
 830         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 831         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 832 }
 833
 834 /*
 835  * Reads environment variables from the given file and adds/overrides them
 836  * into the environment.  If the file does not exist, this does nothing.
 837  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 838  * and assignments of the form name=value.  No other forms are allowed.
 839  */
 840 static void
 841 read_environment_file(char ***env, u_int *envsize,
 842                       const char *filename)
 843 {
 844         FILE *f;
 845         char buf[4096];
 846         char *cp, *value;
 847
 848         f = fopen(filename, "r");
 849         if (!f)
 850                 return;
 851
 852         while (fgets(buf, sizeof(buf), f)) {
 853                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 854                         ;
 855                 if (!*cp || *cp == '#' || *cp == '\n')
 856                         continue;
 857                 if (strchr(cp, '\n'))
 858                         *strchr(cp, '\n') = '\0';
 859                 value = strchr(cp, '=');
 860                 if (value == NULL) {
 861                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 862                         continue;
 863                 }
 864                 /*
 865                  * Replace the equals sign by nul, and advance value to
 866                  * the value string.
 867                  */
 868                 *value = '\0';
 869                 value++;
 870                 child_set_env(env, envsize, cp, value);
 871         }
 872         fclose(f);
 873 }
 874
 875 #ifdef USE_PAM
 876 /*
 877  * Sets any environment variables which have been specified by PAM
 878  */
 879 void do_pam_environment(char ***env, u_int *envsize)
 880 {
 881         char *equals, var_name[512], var_val[512];
 882         char **pam_env;
 883         int i;
 884
 885         if ((pam_env = fetch_pam_environment()) == NULL)
 886                 return;
 887
 888         for(i = 0; pam_env[i] != NULL; i++) {
 889                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 890                         continue;
 891
 892                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 893                         memset(var_name, '\0', sizeof(var_name));
 894                         memset(var_val, '\0', sizeof(var_val));
 895
 896                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 897                         strcpy(var_val, equals + 1);
 898
 899                         debug3("PAM environment: %s=%s", var_name, var_val);
 900
 901                         child_set_env(env, envsize, var_name, var_val);
 902                 }
 903         }
 904 }
 905 #endif /* USE_PAM */
 906
 907 #ifdef HAVE_CYGWIN
 908 void copy_environment(char ***env, u_int *envsize)
 909 {
 910         char *equals, var_name[512], var_val[512];
 911         int i;
 912
 913         for(i = 0; environ[i] != NULL; i++) {
 914                 if ((equals = strstr(environ[i], "=")) == NULL)
 915                         continue;
 916
 917                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 918                         memset(var_name, '\0', sizeof(var_name));
 919                         memset(var_val, '\0', sizeof(var_val));
 920
 921                         strncpy(var_name, environ[i], equals - environ[i]);
 922                         strcpy(var_val, equals + 1);
 923
 924                         debug3("Copy environment: %s=%s", var_name, var_val);
 925
 926                         child_set_env(env, envsize, var_name, var_val);
 927                 }
 928         }
 929 }
 930 #endif
 931
 932 #if defined(HAVE_GETUSERATTR)
 933 /*
 934  * AIX-specific login initialisation
 935  */
 936 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 937 {
 938         struct rlimit rlim;
 939         int slim, hlim;
 940
 941         getrlimit(resource, &rlim);
 942
 943         slim = 0;
 944         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 945                 if (slim < 0) {
 946                         rlim.rlim_cur = RLIM_INFINITY;
 947                 } else if (slim != 0) {
 948                         /* See the wackiness below */
 949                         if (rlim.rlim_cur == slim * mult)
 950                                 slim = 0;
 951                         else
 952                                 rlim.rlim_cur = slim * mult;
 953                 }
 954         }
 955
 956         hlim = 0;
 957         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 958                 if (hlim < 0) {
 959                         rlim.rlim_max = RLIM_INFINITY;
 960                 } else if (hlim != 0) {
 961                         rlim.rlim_max = hlim * mult;
 962                 }
 963         }
 964
 965         /*
 966          * XXX For cpu and fsize the soft limit is set to the hard limit
 967          * if the hard limit is left at its default value and the soft limit
 968          * is changed from its default value, either by requesting it
 969          * (slim == 0) or by setting it to the current default.  At least
 970          * that's how rlogind does it.  If you're confused you're not alone.
 971          * Bug or feature? AIX 4.3.1.2
 972          */
 973         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 974             && hlim == 0 && slim != 0)
 975                 rlim.rlim_max = rlim.rlim_cur;
 976         /* A specified hard limit limits the soft limit */
 977         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 978                 rlim.rlim_cur = rlim.rlim_max;
 979         /* A soft limit can increase a hard limit */
 980         else if (rlim.rlim_cur > rlim.rlim_max)
 981                 rlim.rlim_max = rlim.rlim_cur;
 982
 983         if (setrlimit(resource, &rlim) != 0)
 984                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 985 }
 986
 987 void set_limits_from_userattr(char *user)
 988 {
 989         int mask;
 990         char buf[16];
 991
 992         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 993         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 994         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 995         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 996         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 997         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 998 #if defined(S_UNOFILE)
 999         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1000 #endif
1001
1002         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1003                 /* Convert decimal to octal */
1004                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1005                 if (sscanf(buf, "%o", &mask) == 1)
1006                         umask(mask);
1007         }
1008 }
1009 #endif /* defined(HAVE_GETUSERATTR) */
1010
1011 /*
1012  * Performs common processing for the child, such as setting up the
1013  * environment, closing extra file descriptors, setting the user and group
1014  * ids, and executing the command or shell.
1015  */
1016 void
1017 do_child(Session *s, const char *command)
1018 {
1019         const char *shell, *hostname = NULL, *cp = NULL;
1020         struct passwd *pw = s->pw;
1021         char buf[256];
1022         char cmd[1024];
1023         FILE *f = NULL;
1024         u_int envsize, i;
1025         char **env;
1026         extern char **environ;
1027         struct stat st;
1028         char *argv[10];
1029         int do_xauth;
1030 #ifdef WITH_IRIX_PROJECT
1031         prid_t projid;
1032 #endif /* WITH_IRIX_PROJECT */
1033 #ifdef WITH_IRIX_JOBS
1034         jid_t jid = 0;
1035 #else
1036 #ifdef WITH_IRIX_ARRAY
1037         int jid = 0;
1038 #endif /* WITH_IRIX_ARRAY */
1039 #endif /* WITH_IRIX_JOBS */
1040
1041         do_xauth =
1042             s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1043
1044         /* remove hostkey from the child's memory */
1045         destroy_sensitive_data();
1046
1047         /* login(1) is only called if we execute the login shell */
1048         if (options.use_login && command != NULL)
1049                 options.use_login = 0;
1050
1051 #if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
1052         if (!options.use_login) {
1053 # ifdef HAVE_LOGIN_CAP
1054                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1055                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1056                             _PATH_NOLOGIN), "r");
1057 # else /* HAVE_LOGIN_CAP */
1058                 if (pw->pw_uid)
1059                         f = fopen(_PATH_NOLOGIN, "r");
1060 # endif /* HAVE_LOGIN_CAP */
1061                 if (f) {
1062                         /* /etc/nologin exists.  Print its contents and exit. */
1063                         while (fgets(buf, sizeof(buf), f))
1064                                 fputs(buf, stderr);
1065                         fclose(f);
1066                         exit(254);
1067                 }
1068         }
1069 #endif /* USE_PAM || HAVE_OSF_SIA */
1070
1071         /* Set login name, uid, gid, and groups. */
1072         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1073            switch, so we let login(1) to this for us. */
1074         if (!options.use_login) {
1075 #ifdef HAVE_OSF_SIA
1076                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1077                 if (!check_quietlogin(s, command))
1078                         do_motd();
1079 #else /* HAVE_OSF_SIA */
1080 #ifdef HAVE_CYGWIN
1081                 if (is_winnt) {
1082 #else
1083                 if (getuid() == 0 || geteuid() == 0) {
1084 #endif
1085 # ifdef HAVE_GETUSERATTR
1086                         set_limits_from_userattr(pw->pw_name);
1087 # endif /* HAVE_GETUSERATTR */
1088 # ifdef HAVE_LOGIN_CAP
1089                         if (setusercontext(lc, pw, pw->pw_uid,
1090                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1091                                 perror("unable to set user context");
1092                                 exit(1);
1093                         }
1094 # else /* HAVE_LOGIN_CAP */
1095 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1096                         /* Sets login uid for accounting */
1097                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1098                                 error("setluid: %s", strerror(errno));
1099 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1100
1101                         if (setlogin(pw->pw_name) < 0)
1102                                 error("setlogin failed: %s", strerror(errno));
1103                         if (setgid(pw->pw_gid) < 0) {
1104                                 perror("setgid");
1105                                 exit(1);
1106                         }
1107                         /* Initialize the group list. */
1108                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1109                                 perror("initgroups");
1110                                 exit(1);
1111                         }
1112                         endgrent();
1113 #  ifdef USE_PAM
1114                         /*
1115                          * PAM credentials may take the form of
1116                          * supplementary groups. These will have been
1117                          * wiped by the above initgroups() call.
1118                          * Reestablish them here.
1119                          */
1120                         do_pam_setcred(0);
1121 #  endif /* USE_PAM */
1122 #  ifdef WITH_IRIX_JOBS
1123                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1124                         if (jid == -1) {
1125                                 fatal("Failed to create job container: %.100s",
1126                                       strerror(errno));
1127                         }
1128 #  endif /* WITH_IRIX_JOBS */
1129 #  ifdef WITH_IRIX_ARRAY
1130                         /* initialize array session */
1131                         if (jid == 0) {
1132                                 if (newarraysess() != 0)
1133                                         fatal("Failed to set up new array session: %.100s",
1134                                               strerror(errno));
1135                         }
1136 #  endif /* WITH_IRIX_ARRAY */
1137 #  ifdef WITH_IRIX_PROJECT
1138                         /* initialize irix project info */
1139                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1140                           debug("Failed to get project id, using projid 0");
1141                           projid = 0;
1142                         }
1143                         if (setprid(projid))
1144                           fatal("Failed to initialize project %d for %s: %.100s",
1145                                 (int)projid, pw->pw_name, strerror(errno));
1146 #  endif /* WITH_IRIX_PROJECT */
1147 #ifdef WITH_IRIX_AUDIT
1148                         if (sysconf(_SC_AUDIT)) {
1149                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1150                                 if (satsetid(pw->pw_uid))
1151                                         debug("error setting satid: %.100s", strerror(errno));
1152                         }
1153 #endif /* WITH_IRIX_AUDIT */
1154
1155 #ifdef _AIX
1156                         /*
1157                          * AIX has a "usrinfo" area where logname and
1158                          * other stuff is stored - a few applications
1159                          * actually use this and die if it's not set
1160                          */
1161                         if (s->ttyfd == -1)
1162                                 s->tty[0] = '\0';
1163                         cp = xmalloc(22 + strlen(s->tty) +
1164                             2 * strlen(pw->pw_name));
1165                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1166                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1167                         if (usrinfo(SETUINFO, cp, i) == -1)
1168                                 fatal("Couldn't set usrinfo: %s",
1169                                     strerror(errno));
1170                         debug3("AIX/UsrInfo: set len %d", i);
1171                         xfree(cp);
1172 #endif
1173
1174                         /* Permanently switch to the desired uid. */
1175                         permanently_set_uid(pw);
1176 # endif /* HAVE_LOGIN_CAP */
1177                 }
1178 #endif /* HAVE_OSF_SIA */
1179
1180 #ifdef HAVE_CYGWIN
1181                 if (is_winnt)
1182 #endif
1183                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1184                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1185         }
1186         /*
1187          * Get the shell from the password data.  An empty shell field is
1188          * legal, and means /bin/sh.
1189          */
1190         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1191 #ifdef HAVE_LOGIN_CAP
1192         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1193 #endif
1194
1195 #ifdef AFS
1196         /* Try to get AFS tokens for the local cell. */
1197         if (k_hasafs()) {
1198                 char cell[64];
1199
1200                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1201                         krb_afslog(cell, 0);
1202
1203                 krb_afslog(0, 0);
1204         }
1205 #endif /* AFS */
1206
1207         /* Initialize the environment. */
1208         envsize = 100;
1209         env = xmalloc(envsize * sizeof(char *));
1210         env[0] = NULL;
1211
1212 #ifdef HAVE_CYGWIN
1213         /*
1214          * The Windows environment contains some setting which are
1215          * important for a running system. They must not be dropped.
1216          */
1217         copy_environment(&env, &envsize);
1218 #endif
1219
1220         if (!options.use_login) {
1221                 /* Set basic environment. */
1222                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1223                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1224                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1225 #ifdef HAVE_LOGIN_CAP
1226                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1227                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1228 #else /* HAVE_LOGIN_CAP */
1229 # ifndef HAVE_CYGWIN
1230                 /*
1231                  * There's no standard path on Windows. The path contains
1232                  * important components pointing to the system directories,
1233                  * needed for loading shared libraries. So the path better
1234                  * remains intact here.
1235                  */
1236                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1237 # endif /* HAVE_CYGWIN */
1238 #endif /* HAVE_LOGIN_CAP */
1239
1240                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1241                          _PATH_MAILDIR, pw->pw_name);
1242                 child_set_env(&env, &envsize, "MAIL", buf);
1243
1244                 /* Normal systems set SHELL by default. */
1245                 child_set_env(&env, &envsize, "SHELL", shell);
1246         }
1247         if (getenv("TZ"))
1248                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1249
1250         /* Set custom environment options from RSA authentication. */
1251         while (custom_environment) {
1252                 struct envstring *ce = custom_environment;
1253                 char *s = ce->s;
1254                 int i;
1255                 for (i = 0; s[i] != '=' && s[i]; i++);
1256                 if (s[i] == '=') {
1257                         s[i] = 0;
1258                         child_set_env(&env, &envsize, s, s + i + 1);
1259                 }
1260                 custom_environment = ce->next;
1261                 xfree(ce->s);
1262                 xfree(ce);
1263         }
1264
1265         snprintf(buf, sizeof buf, "%.50s %d %d",
1266                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1267         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1268
1269         if (s->ttyfd != -1)
1270                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1271         if (s->term)
1272                 child_set_env(&env, &envsize, "TERM", s->term);
1273         if (s->display)
1274                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1275         if (original_command)
1276                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1277                     original_command);
1278
1279 #ifdef _AIX
1280         if ((cp = getenv("AUTHSTATE")) != NULL)
1281                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1282         if ((cp = getenv("KRB5CCNAME")) != NULL)
1283                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1284         read_environment_file(&env, &envsize, "/etc/environment");
1285 #endif
1286 #ifdef KRB4
1287         if (s->authctxt->krb4_ticket_file)
1288                 child_set_env(&env, &envsize, "KRBTKFILE",
1289                     s->authctxt->krb4_ticket_file);
1290 #endif
1291 #ifdef KRB5
1292         if (s->authctxt->krb5_ticket_file)
1293                 child_set_env(&env, &envsize, "KRB5CCNAME",
1294                     s->authctxt->krb5_ticket_file);
1295 #endif
1296 #ifdef USE_PAM
1297         /* Pull in any environment variables that may have been set by PAM. */
1298         do_pam_environment(&env, &envsize);
1299 #endif /* USE_PAM */
1300
1301         if (auth_get_socket_name() != NULL)
1302                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1303                               auth_get_socket_name());
1304
1305         /* read $HOME/.ssh/environment. */
1306         if (!options.use_login) {
1307                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1308                     pw->pw_dir);
1309                 read_environment_file(&env, &envsize, buf);
1310         }
1311         if (debug_flag) {
1312                 /* dump the environment */
1313                 fprintf(stderr, "Environment:\n");
1314                 for (i = 0; env[i]; i++)
1315                         fprintf(stderr, "  %.200s\n", env[i]);
1316         }
1317         /* we have to stash the hostname before we close our socket. */
1318         if (options.use_login)
1319                 hostname = get_remote_name_or_ip(utmp_len,
1320                     options.reverse_mapping_check);
1321         /*
1322          * Close the connection descriptors; note that this is the child, and
1323          * the server will still have the socket open, and it is important
1324          * that we do not shutdown it.  Note that the descriptors cannot be
1325          * closed before building the environment, as we call
1326          * get_remote_ipaddr there.
1327          */
1328         if (packet_get_connection_in() == packet_get_connection_out())
1329                 close(packet_get_connection_in());
1330         else {
1331                 close(packet_get_connection_in());
1332                 close(packet_get_connection_out());
1333         }
1334         /*
1335          * Close all descriptors related to channels.  They will still remain
1336          * open in the parent.
1337          */
1338         /* XXX better use close-on-exec? -markus */
1339         channel_close_all();
1340
1341         /*
1342          * Close any extra file descriptors.  Note that there may still be
1343          * descriptors left by system functions.  They will be closed later.
1344          */
1345         endpwent();
1346
1347         /*
1348          * Close any extra open file descriptors so that we don\'t have them
1349          * hanging around in clients.  Note that we want to do this after
1350          * initgroups, because at least on Solaris 2.3 it leaves file
1351          * descriptors open.
1352          */
1353         for (i = 3; i < 64; i++)
1354                 close(i);
1355
1356         /* Change current directory to the user\'s home directory. */
1357         if (chdir(pw->pw_dir) < 0) {
1358                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1359                         pw->pw_dir, strerror(errno));
1360 #ifdef HAVE_LOGIN_CAP
1361                 if (login_getcapbool(lc, "requirehome", 0))
1362                         exit(1);
1363 #endif
1364         }
1365
1366         /*
1367          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1368          * xauth are run in the proper environment.
1369          */
1370         environ = env;
1371
1372         /*
1373          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1374          * in this order).
1375          */
1376         if (!options.use_login) {
1377                 /* ignore _PATH_SSH_USER_RC for subsystems */
1378                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1379                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1380                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1381                         if (debug_flag)
1382                                 fprintf(stderr, "Running %s\n", cmd);
1383                         f = popen(cmd, "w");
1384                         if (f) {
1385                                 if (do_xauth)
1386                                         fprintf(f, "%s %s\n", s->auth_proto,
1387                                             s->auth_data);
1388                                 pclose(f);
1389                         } else
1390                                 fprintf(stderr, "Could not run %s\n",
1391                                     _PATH_SSH_USER_RC);
1392                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1393                         if (debug_flag)
1394                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1395                                     _PATH_SSH_SYSTEM_RC);
1396                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1397                         if (f) {
1398                                 if (do_xauth)
1399                                         fprintf(f, "%s %s\n", s->auth_proto,
1400                                             s->auth_data);
1401                                 pclose(f);
1402                         } else
1403                                 fprintf(stderr, "Could not run %s\n",
1404                                     _PATH_SSH_SYSTEM_RC);
1405                 } else if (do_xauth && options.xauth_location != NULL) {
1406                         /* Add authority data to .Xauthority if appropriate. */
1407                         char *screen = strchr(s->display, ':');
1408
1409                         if (debug_flag) {
1410                                 fprintf(stderr,
1411                                     "Running %.100s add "
1412                                     "%.100s %.100s %.100s\n",
1413                                     options.xauth_location, s->display,
1414                                     s->auth_proto, s->auth_data);
1415                                 if (screen != NULL)
1416                                         fprintf(stderr,
1417                                             "Adding %.*s/unix%s %s %s\n",
1418                                             (int)(screen - s->display),
1419                                             s->display, screen,
1420                                             s->auth_proto, s->auth_data);
1421                         }
1422                         snprintf(cmd, sizeof cmd, "%s -q -",
1423                             options.xauth_location);
1424                         f = popen(cmd, "w");
1425                         if (f) {
1426                                 fprintf(f, "add %s %s %s\n", s->display,
1427                                     s->auth_proto, s->auth_data);
1428                                 if (screen != NULL)
1429                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1430                                             (int)(screen - s->display),
1431                                             s->display, screen,
1432                                             s->auth_proto,
1433                                             s->auth_data);
1434                                 pclose(f);
1435                         } else {
1436                                 fprintf(stderr, "Could not run %s\n",
1437                                     cmd);
1438                         }
1439                 }
1440                 /* Get the last component of the shell name. */
1441                 cp = strrchr(shell, '/');
1442                 if (cp)
1443                         cp++;
1444                 else
1445                         cp = shell;
1446         }
1447
1448         /* restore SIGPIPE for child */
1449         signal(SIGPIPE,  SIG_DFL);
1450
1451         /*
1452          * If we have no command, execute the shell.  In this case, the shell
1453          * name to be passed in argv[0] is preceded by '-' to indicate that
1454          * this is a login shell.
1455          */
1456         if (!command) {
1457                 if (!options.use_login) {
1458                         char buf[256];
1459
1460                         /*
1461                          * Check for mail if we have a tty and it was enabled
1462                          * in server options.
1463                          */
1464                         if (s->ttyfd != -1 && options.check_mail) {
1465                                 char *mailbox;
1466                                 struct stat mailstat;
1467
1468                                 mailbox = getenv("MAIL");
1469                                 if (mailbox != NULL) {
1470                                         if (stat(mailbox, &mailstat) != 0 ||
1471                                             mailstat.st_size == 0)
1472                                                 printf("No mail.\n");
1473                                         else if (mailstat.st_mtime < mailstat.st_atime)
1474                                                 printf("You have mail.\n");
1475                                         else
1476                                                 printf("You have new mail.\n");
1477                                 }
1478                         }
1479                         /* Start the shell.  Set initial character to '-'. */
1480                         buf[0] = '-';
1481                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1482                         buf[sizeof(buf) - 1] = 0;
1483
1484                         /* Execute the shell. */
1485                         argv[0] = buf;
1486                         argv[1] = NULL;
1487                         execve(shell, argv, env);
1488
1489                         /* Executing the shell failed. */
1490                         perror(shell);
1491                         exit(1);
1492
1493                 } else {
1494                         /* Launch login(1). */
1495
1496                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1497 #ifdef LOGIN_NEEDS_TERM
1498                              s->term? s->term : "unknown",
1499 #endif
1500                              "-p", "-f", "--", pw->pw_name, NULL);
1501
1502                         /* Login couldn't be executed, die. */
1503
1504                         perror("login");
1505                         exit(1);
1506                 }
1507         }
1508         /*
1509          * Execute the command using the user's shell.  This uses the -c
1510          * option to execute the command.
1511          */
1512         argv[0] = (char *) cp;
1513         argv[1] = "-c";
1514         argv[2] = (char *) command;
1515         argv[3] = NULL;
1516         execve(shell, argv, env);
1517         perror(shell);
1518         exit(1);
1519 }
1520
1521 Session *
1522 session_new(void)
1523 {
1524         int i;
1525         static int did_init = 0;
1526         if (!did_init) {
1527                 debug("session_new: init");
1528                 for(i = 0; i < MAX_SESSIONS; i++) {
1529                         sessions[i].used = 0;
1530                 }
1531                 did_init = 1;
1532         }
1533         for(i = 0; i < MAX_SESSIONS; i++) {
1534                 Session *s = &sessions[i];
1535                 if (! s->used) {
1536                         memset(s, 0, sizeof(*s));
1537                         s->chanid = -1;
1538                         s->ptyfd = -1;
1539                         s->ttyfd = -1;
1540                         s->used = 1;
1541                         s->self = i;
1542                         debug("session_new: session %d", i);
1543                         return s;
1544                 }
1545         }
1546         return NULL;
1547 }
1548
1549 static void
1550 session_dump(void)
1551 {
1552         int i;
1553         for(i = 0; i < MAX_SESSIONS; i++) {
1554                 Session *s = &sessions[i];
1555                 debug("dump: used %d session %d %p channel %d pid %d",
1556                     s->used,
1557                     s->self,
1558                     s,
1559                     s->chanid,
1560                     s->pid);
1561         }
1562 }
1563
1564 int
1565 session_open(int chanid)
1566 {
1567         Session *s = session_new();
1568         debug("session_open: channel %d", chanid);
1569         if (s == NULL) {
1570                 error("no more sessions");
1571                 return 0;
1572         }
1573         s->pw = auth_get_user();
1574         if (s->pw == NULL)
1575                 fatal("no user for session %d", s->self);
1576         debug("session_open: session %d: link with channel %d", s->self, chanid);
1577         s->chanid = chanid;
1578         return 1;
1579 }
1580
1581 static Session *
1582 session_by_channel(int id)
1583 {
1584         int i;
1585         for(i = 0; i < MAX_SESSIONS; i++) {
1586                 Session *s = &sessions[i];
1587                 if (s->used && s->chanid == id) {
1588                         debug("session_by_channel: session %d channel %d", i, id);
1589                         return s;
1590                 }
1591         }
1592         debug("session_by_channel: unknown channel %d", id);
1593         session_dump();
1594         return NULL;
1595 }
1596
1597 static Session *
1598 session_by_pid(pid_t pid)
1599 {
1600         int i;
1601         debug("session_by_pid: pid %d", pid);
1602         for(i = 0; i < MAX_SESSIONS; i++) {
1603                 Session *s = &sessions[i];
1604                 if (s->used && s->pid == pid)
1605                         return s;
1606         }
1607         error("session_by_pid: unknown pid %d", pid);
1608         session_dump();
1609         return NULL;
1610 }
1611
1612 static int
1613 session_window_change_req(Session *s)
1614 {
1615         s->col = packet_get_int();
1616         s->row = packet_get_int();
1617         s->xpixel = packet_get_int();
1618         s->ypixel = packet_get_int();
1619         packet_done();
1620         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1621         return 1;
1622 }
1623
1624 static int
1625 session_pty_req(Session *s)
1626 {
1627         u_int len;
1628         int n_bytes;
1629
1630         if (no_pty_flag) {
1631                 debug("Allocating a pty not permitted for this authentication.");
1632                 return 0;
1633         }
1634         if (s->ttyfd != -1) {
1635                 packet_disconnect("Protocol error: you already have a pty.");
1636                 return 0;
1637         }
1638
1639         s->term = packet_get_string(&len);
1640
1641         if (compat20) {
1642                 s->col = packet_get_int();
1643                 s->row = packet_get_int();
1644         } else {
1645                 s->row = packet_get_int();
1646                 s->col = packet_get_int();
1647         }
1648         s->xpixel = packet_get_int();
1649         s->ypixel = packet_get_int();
1650
1651         if (strcmp(s->term, "") == 0) {
1652                 xfree(s->term);
1653                 s->term = NULL;
1654         }
1655
1656         /* Allocate a pty and open it. */
1657         debug("Allocating pty.");
1658         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1659                 if (s->term)
1660                         xfree(s->term);
1661                 s->term = NULL;
1662                 s->ptyfd = -1;
1663                 s->ttyfd = -1;
1664                 error("session_pty_req: session %d alloc failed", s->self);
1665                 return 0;
1666         }
1667         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1668
1669         /* for SSH1 the tty modes length is not given */
1670         if (!compat20)
1671                 n_bytes = packet_remaining();
1672         tty_parse_modes(s->ttyfd, &n_bytes);
1673
1674         /*
1675          * Add a cleanup function to clear the utmp entry and record logout
1676          * time in case we call fatal() (e.g., the connection gets closed).
1677          */
1678         fatal_add_cleanup(session_pty_cleanup, (void *)s);
1679         pty_setowner(s->pw, s->tty);
1680
1681         /* Set window size from the packet. */
1682         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1683
1684         packet_done();
1685         session_proctitle(s);
1686         return 1;
1687 }
1688
1689 static int
1690 session_subsystem_req(Session *s)
1691 {
1692         u_int len;
1693         int success = 0;
1694         char *subsys = packet_get_string(&len);
1695         int i;
1696
1697         packet_done();
1698         log("subsystem request for %s", subsys);
1699
1700         for (i = 0; i < options.num_subsystems; i++) {
1701                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1702                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1703                         s->is_subsystem = 1;
1704                         do_exec_no_pty(s, options.subsystem_command[i]);
1705                         success = 1;
1706                 }
1707         }
1708
1709         if (!success)
1710                 log("subsystem request for %s failed, subsystem not found", subsys);
1711
1712         xfree(subsys);
1713         return success;
1714 }
1715
1716 static int
1717 session_x11_req(Session *s)
1718 {
1719         int success;
1720
1721         s->single_connection = packet_get_char();
1722         s->auth_proto = packet_get_string(NULL);
1723         s->auth_data = packet_get_string(NULL);
1724         s->screen = packet_get_int();
1725         packet_done();
1726
1727         success = session_setup_x11fwd(s);
1728         if (!success) {
1729                 xfree(s->auth_proto);
1730                 xfree(s->auth_data);
1731                 s->auth_proto = NULL;
1732                 s->auth_data = NULL;
1733         }
1734         return success;
1735 }
1736
1737 static int
1738 session_shell_req(Session *s)
1739 {
1740         packet_done();
1741         do_exec(s, NULL);
1742         return 1;
1743 }
1744
1745 static int
1746 session_exec_req(Session *s)
1747 {
1748         u_int len;
1749         char *command = packet_get_string(&len);
1750         packet_done();
1751         do_exec(s, command);
1752         xfree(command);
1753         return 1;
1754 }
1755
1756 static int
1757 session_auth_agent_req(Session *s)
1758 {
1759         static int called = 0;
1760         packet_done();
1761         if (no_agent_forwarding_flag) {
1762                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1763                 return 0;
1764         }
1765         if (called) {
1766                 return 0;
1767         } else {
1768                 called = 1;
1769                 return auth_input_request_forwarding(s->pw);
1770         }
1771 }
1772
1773 void
1774 session_input_channel_req(int id, void *arg)
1775 {
1776         u_int len;
1777         int reply;
1778         int success = 0;
1779         char *rtype;
1780         Session *s;
1781         Channel *c;
1782
1783         rtype = packet_get_string(&len);
1784         reply = packet_get_char();
1785
1786         s = session_by_channel(id);
1787         if (s == NULL)
1788                 fatal("session_input_channel_req: channel %d: no session", id);
1789         c = channel_lookup(id);
1790         if (c == NULL)
1791                 fatal("session_input_channel_req: channel %d: bad channel", id);
1792
1793         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1794             s->self, id, rtype, reply);
1795
1796         /*
1797          * a session is in LARVAL state until a shell, a command
1798          * or a subsystem is executed
1799          */
1800         if (c->type == SSH_CHANNEL_LARVAL) {
1801                 if (strcmp(rtype, "shell") == 0) {
1802                         success = session_shell_req(s);
1803                 } else if (strcmp(rtype, "exec") == 0) {
1804                         success = session_exec_req(s);
1805                 } else if (strcmp(rtype, "pty-req") == 0) {
1806                         success =  session_pty_req(s);
1807                 } else if (strcmp(rtype, "x11-req") == 0) {
1808                         success = session_x11_req(s);
1809                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1810                         success = session_auth_agent_req(s);
1811                 } else if (strcmp(rtype, "subsystem") == 0) {
1812                         success = session_subsystem_req(s);
1813                 }
1814         }
1815         if (strcmp(rtype, "window-change") == 0) {
1816                 success = session_window_change_req(s);
1817         }
1818
1819         if (reply) {
1820                 packet_start(success ?
1821                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1822                 packet_put_int(c->remote_id);
1823                 packet_send();
1824         }
1825         xfree(rtype);
1826 }
1827
1828 void
1829 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1830 {
1831         if (!compat20)
1832                 fatal("session_set_fds: called for proto != 2.0");
1833         /*
1834          * now that have a child and a pipe to the child,
1835          * we can activate our channel and register the fd's
1836          */
1837         if (s->chanid == -1)
1838                 fatal("no channel for session %d", s->self);
1839         channel_set_fds(s->chanid,
1840             fdout, fdin, fderr,
1841             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1842             1);
1843 }
1844
1845 /*
1846  * Function to perform pty cleanup. Also called if we get aborted abnormally
1847  * (e.g., due to a dropped connection).
1848  */
1849 static void
1850 session_pty_cleanup(void *session)
1851 {
1852         Session *s = session;
1853
1854         if (s == NULL) {
1855                 error("session_pty_cleanup: no session");
1856                 return;
1857         }
1858         if (s->ttyfd == -1)
1859                 return;
1860
1861         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1862
1863         /* Record that the user has logged out. */
1864         if (s->pid != 0)
1865                 record_logout(s->pid, s->tty);
1866
1867         /* Release the pseudo-tty. */
1868         pty_release(s->tty);
1869
1870         /*
1871          * Close the server side of the socket pairs.  We must do this after
1872          * the pty cleanup, so that another process doesn't get this pty
1873          * while we're still cleaning up.
1874          */
1875         if (close(s->ptymaster) < 0)
1876                 error("close(s->ptymaster): %s", strerror(errno));
1877 }
1878
1879 static void
1880 session_exit_message(Session *s, int status)
1881 {
1882         Channel *c;
1883         if (s == NULL)
1884                 fatal("session_close: no session");
1885         c = channel_lookup(s->chanid);
1886         if (c == NULL)
1887                 fatal("session_exit_message: session %d: no channel %d",
1888                     s->self, s->chanid);
1889         debug("session_exit_message: session %d channel %d pid %d",
1890             s->self, s->chanid, s->pid);
1891
1892         if (WIFEXITED(status)) {
1893                 channel_request_start(s->chanid,
1894                     "exit-status", 0);
1895                 packet_put_int(WEXITSTATUS(status));
1896                 packet_send();
1897         } else if (WIFSIGNALED(status)) {
1898                 channel_request_start(s->chanid,
1899                     "exit-signal", 0);
1900                 packet_put_int(WTERMSIG(status));
1901 #ifdef WCOREDUMP
1902                 packet_put_char(WCOREDUMP(status));
1903 #else /* WCOREDUMP */
1904                 packet_put_char(0);
1905 #endif /* WCOREDUMP */
1906                 packet_put_cstring("");
1907                 packet_put_cstring("");
1908                 packet_send();
1909         } else {
1910                 /* Some weird exit cause.  Just exit. */
1911                 packet_disconnect("wait returned status %04x.", status);
1912         }
1913
1914         /* disconnect channel */
1915         debug("session_exit_message: release channel %d", s->chanid);
1916         channel_cancel_cleanup(s->chanid);
1917         /*
1918          * emulate a write failure with 'chan_write_failed', nobody will be
1919          * interested in data we write.
1920          * Note that we must not call 'chan_read_failed', since there could
1921          * be some more data waiting in the pipe.
1922          */
1923         if (c->ostate != CHAN_OUTPUT_CLOSED)
1924                 chan_write_failed(c);
1925         s->chanid = -1;
1926 }
1927
1928 static void
1929 session_close(Session *s)
1930 {
1931         debug("session_close: session %d pid %d", s->self, s->pid);
1932         if (s->ttyfd != -1) {
1933                 fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1934                 session_pty_cleanup(s);
1935         }
1936         if (s->term)
1937                 xfree(s->term);
1938         if (s->display)
1939                 xfree(s->display);
1940         if (s->auth_data)
1941                 xfree(s->auth_data);
1942         if (s->auth_proto)
1943                 xfree(s->auth_proto);
1944         s->used = 0;
1945         session_proctitle(s);
1946 }
1947
1948 void
1949 session_close_by_pid(pid_t pid, int status)
1950 {
1951         Session *s = session_by_pid(pid);
1952         if (s == NULL) {
1953                 debug("session_close_by_pid: no session for pid %d", pid);
1954                 return;
1955         }
1956         if (s->chanid != -1)
1957                 session_exit_message(s, status);
1958         session_close(s);
1959 }
1960
1961 /*
1962  * this is called when a channel dies before
1963  * the session 'child' itself dies
1964  */
1965 void
1966 session_close_by_channel(int id, void *arg)
1967 {
1968         Session *s = session_by_channel(id);
1969         if (s == NULL) {
1970                 debug("session_close_by_channel: no session for channel %d", id);
1971                 return;
1972         }
1973         /* disconnect channel */
1974         channel_cancel_cleanup(s->chanid);
1975         s->chanid = -1;
1976
1977         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1978         if (s->pid == 0) {
1979                 /* close session immediately */
1980                 session_close(s);
1981         } else {
1982                 /* notify child, delay session cleanup */
1983                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1984                         error("session_close_by_channel: kill %d: %s",
1985                             s->pid, strerror(errno));
1986         }
1987 }
1988
1989 static char *
1990 session_tty_list(void)
1991 {
1992         static char buf[1024];
1993         int i;
1994         buf[0] = '\0';
1995         for(i = 0; i < MAX_SESSIONS; i++) {
1996                 Session *s = &sessions[i];
1997                 if (s->used && s->ttyfd != -1) {
1998                         if (buf[0] != '\0')
1999                                 strlcat(buf, ",", sizeof buf);
2000                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2001                 }
2002         }
2003         if (buf[0] == '\0')
2004                 strlcpy(buf, "notty", sizeof buf);
2005         return buf;
2006 }
2007
2008 void
2009 session_proctitle(Session *s)
2010 {
2011         if (s->pw == NULL)
2012                 error("no user for session %d", s->self);
2013         else
2014                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2015 }
2016
2017 int
2018 session_setup_x11fwd(Session *s)
2019 {
2020         struct stat st;
2021
2022         if (no_x11_forwarding_flag) {
2023                 packet_send_debug("X11 forwarding disabled in user configuration file.");
2024                 return 0;
2025         }
2026         if (!options.x11_forwarding) {
2027                 debug("X11 forwarding disabled in server configuration file.");
2028                 return 0;
2029         }
2030         if (!options.xauth_location ||
2031             (stat(options.xauth_location, &st) == -1)) {
2032                 packet_send_debug("No xauth program; cannot forward with spoofing.");
2033                 return 0;
2034         }
2035         if (options.use_login) {
2036                 packet_send_debug("X11 forwarding disabled; "
2037                     "not compatible with UseLogin=yes.");
2038                 return 0;
2039         }
2040         if (s->display != NULL) {
2041                 debug("X11 display already set.");
2042                 return 0;
2043         }
2044         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
2045         if (s->display == NULL) {
2046                 debug("x11_create_display_inet failed.");
2047                 return 0;
2048         }
2049         return 1;
2050 }
2051
2052 static void
2053 do_authenticated2(Authctxt *authctxt)
2054 {
2055         server_loop2();
2056 }