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 1.100 2001/08/16 19:18:34 jakob 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 int     check_quietlogin(Session *, const char *);
 135
 136 static void do_authenticated1(Authctxt *);
 137 static void do_authenticated2(Authctxt *);
 138
 139 static void session_close(Session *);
 140 static int session_pty_req(Session *);
 141
 142 /* import */
 143 extern ServerOptions options;
 144 extern char *__progname;
 145 extern int log_stderr;
 146 extern int debug_flag;
 147 extern u_int utmp_len;
 148 extern int startup_pipe;
 149 extern void destroy_sensitive_data(void);
 150
 151 /* original command from peer. */
 152 const char *original_command = NULL;
 153
 154 /* data */
 155 #define MAX_SESSIONS 10
 156 Session sessions[MAX_SESSIONS];
 157
 158 #ifdef WITH_AIXAUTHENTICATE
 159 /* AIX's lastlogin message, set in auth1.c */
 160 char *aixloginmsg;
 161 #endif /* WITH_AIXAUTHENTICATE */
 162
 163 #ifdef HAVE_LOGIN_CAP
 164 static login_cap_t *lc;
 165 #endif
 166
 167 void
 168 do_authenticated(Authctxt *authctxt)
 169 {
 170         /*
 171          * Cancel the alarm we set to limit the time taken for
 172          * authentication.
 173          */
 174         alarm(0);
 175         if (startup_pipe != -1) {
 176                 close(startup_pipe);
 177                 startup_pipe = -1;
 178         }
 179 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 180         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 181                 error("unable to get login class");
 182                 return;
 183         }
 184 #ifdef BSD_AUTH
 185         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 186                 packet_disconnect("Approval failure for %s",
 187                     authctxt->pw->pw_name);
 188         }
 189 #endif
 190 #endif
 191         /* setup the channel layer */
 192         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 193                 channel_permit_all_opens();
 194
 195         if (compat20)
 196                 do_authenticated2(authctxt);
 197         else
 198                 do_authenticated1(authctxt);
 199
 200         /* remove agent socket */
 201         if (auth_get_socket_name())
 202                 auth_sock_cleanup_proc(authctxt->pw);
 203 #ifdef KRB4
 204         if (options.kerberos_ticket_cleanup)
 205                 krb4_cleanup_proc(authctxt);
 206 #endif
 207 #ifdef KRB5
 208         if (options.kerberos_ticket_cleanup)
 209                 krb5_cleanup_proc(authctxt);
 210 #endif
 211 }
 212
 213 /*
 214  * Prepares for an interactive session.  This is called after the user has
 215  * been successfully authenticated.  During this message exchange, pseudo
 216  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 217  * are requested, etc.
 218  */
 219 static void
 220 do_authenticated1(Authctxt *authctxt)
 221 {
 222         Session *s;
 223         char *command;
 224         int success, type, plen, screen_flag;
 225         int compression_level = 0, enable_compression_after_reply = 0;
 226         u_int proto_len, data_len, dlen;
 227
 228         s = session_new();
 229         s->authctxt = authctxt;
 230         s->pw = authctxt->pw;
 231
 232         /*
 233          * We stay in this loop until the client requests to execute a shell
 234          * or a command.
 235          */
 236         for (;;) {
 237                 success = 0;
 238
 239                 /* Get a packet from the client. */
 240                 type = packet_read(&plen);
 241
 242                 /* Process the packet. */
 243                 switch (type) {
 244                 case SSH_CMSG_REQUEST_COMPRESSION:
 245                         packet_integrity_check(plen, 4, type);
 246                         compression_level = packet_get_int();
 247                         if (compression_level < 1 || compression_level > 9) {
 248                                 packet_send_debug("Received illegal compression level %d.",
 249                                      compression_level);
 250                                 break;
 251                         }
 252                         /* Enable compression after we have responded with SUCCESS. */
 253                         enable_compression_after_reply = 1;
 254                         success = 1;
 255                         break;
 256
 257                 case SSH_CMSG_REQUEST_PTY:
 258                         success = session_pty_req(s);
 259                         break;
 260
 261                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 262                         s->auth_proto = packet_get_string(&proto_len);
 263                         s->auth_data = packet_get_string(&data_len);
 264
 265                         screen_flag = packet_get_protocol_flags() &
 266                             SSH_PROTOFLAG_SCREEN_NUMBER;
 267                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 268
 269                         if (packet_remaining() == 4) {
 270                                 if (!screen_flag)
 271                                         debug2("Buggy client: "
 272                                             "X11 screen flag missing");
 273                                 s->screen = packet_get_int();
 274                         } else {
 275                                 s->screen = 0;
 276                         }
 277                         packet_done();
 278                         success = session_setup_x11fwd(s);
 279                         if (!success) {
 280                                 xfree(s->auth_proto);
 281                                 xfree(s->auth_data);
 282                                 s->auth_proto = NULL;
 283                                 s->auth_data = NULL;
 284                         }
 285                         break;
 286
 287                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 288                         if (no_agent_forwarding_flag || compat13) {
 289                                 debug("Authentication agent forwarding not permitted for this authentication.");
 290                                 break;
 291                         }
 292                         debug("Received authentication agent forwarding request.");
 293                         success = auth_input_request_forwarding(s->pw);
 294                         break;
 295
 296                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 297                         if (no_port_forwarding_flag) {
 298                                 debug("Port forwarding not permitted for this authentication.");
 299                                 break;
 300                         }
 301                         if (!options.allow_tcp_forwarding) {
 302                                 debug("Port forwarding not permitted.");
 303                                 break;
 304                         }
 305                         debug("Received TCP/IP port forwarding request.");
 306                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 307                         success = 1;
 308                         break;
 309
 310                 case SSH_CMSG_MAX_PACKET_SIZE:
 311                         if (packet_set_maxsize(packet_get_int()) > 0)
 312                                 success = 1;
 313                         break;
 314
 315 #if defined(AFS) || defined(KRB5)
 316                 case SSH_CMSG_HAVE_KERBEROS_TGT:
 317                         if (!options.kerberos_tgt_passing) {
 318                                 verbose("Kerberos TGT passing disabled.");
 319                         } else {
 320                                 char *kdata = packet_get_string(&dlen);
 321                                 packet_integrity_check(plen, 4 + dlen, type);
 322
 323                                 /* XXX - 0x41, see creds_to_radix version */
 324                                 if (kdata[0] != 0x41) {
 325 #ifdef KRB5
 326                                         krb5_data tgt;
 327                                         tgt.data = kdata;
 328                                         tgt.length = dlen;
 329
 330                                         if (auth_krb5_tgt(s->authctxt, &tgt))
 331                                                 success = 1;
 332                                         else
 333                                                 verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
 334 #endif /* KRB5 */
 335                                 } else {
 336 #ifdef AFS
 337                                         if (auth_krb4_tgt(s->authctxt, kdata))
 338                                                 success = 1;
 339                                         else
 340                                                 verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
 341 #endif /* AFS */
 342                                 }
 343                                 xfree(kdata);
 344                         }
 345                         break;
 346 #endif /* AFS || KRB5 */
 347
 348 #ifdef AFS
 349                 case SSH_CMSG_HAVE_AFS_TOKEN:
 350                         if (!options.afs_token_passing || !k_hasafs()) {
 351                                 verbose("AFS token passing disabled.");
 352                         } else {
 353                                 /* Accept AFS token. */
 354                                 char *token = packet_get_string(&dlen);
 355                                 packet_integrity_check(plen, 4 + dlen, type);
 356
 357                                 if (auth_afs_token(s->authctxt, token))
 358                                         success = 1;
 359                                 else
 360                                         verbose("AFS token refused for %.100s",
 361                                             s->authctxt->user);
 362                                 xfree(token);
 363                         }
 364                         break;
 365 #endif /* AFS */
 366
 367                 case SSH_CMSG_EXEC_SHELL:
 368                 case SSH_CMSG_EXEC_CMD:
 369                         if (type == SSH_CMSG_EXEC_CMD) {
 370                                 command = packet_get_string(&dlen);
 371                                 debug("Exec command '%.500s'", command);
 372                                 do_exec(s, command);
 373                                 xfree(command);
 374                         } else {
 375                                 do_exec(s, NULL);
 376                         }
 377                         packet_done();
 378                         session_close(s);
 379                         return;
 380
 381                 default:
 382                         /*
 383                          * Any unknown messages in this phase are ignored,
 384                          * and a failure message is returned.
 385                          */
 386                         log("Unknown packet type received after authentication: %d", type);
 387                 }
 388                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 389                 packet_send();
 390                 packet_write_wait();
 391
 392                 /* Enable compression now that we have replied if appropriate. */
 393                 if (enable_compression_after_reply) {
 394                         enable_compression_after_reply = 0;
 395                         packet_start_compression(compression_level);
 396                 }
 397         }
 398 }
 399
 400 /*
 401  * This is called to fork and execute a command when we have no tty.  This
 402  * will call do_child from the child, and server_loop from the parent after
 403  * setting up file descriptors and such.
 404  */
 405 void
 406 do_exec_no_pty(Session *s, const char *command)
 407 {
 408         int pid;
 409
 410 #ifdef USE_PIPES
 411         int pin[2], pout[2], perr[2];
 412         /* Allocate pipes for communicating with the program. */
 413         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 414                 packet_disconnect("Could not create pipes: %.100s",
 415                                   strerror(errno));
 416 #else /* USE_PIPES */
 417         int inout[2], err[2];
 418         /* Uses socket pairs to communicate with the program. */
 419         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 420             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 421                 packet_disconnect("Could not create socket pairs: %.100s",
 422                                   strerror(errno));
 423 #endif /* USE_PIPES */
 424         if (s == NULL)
 425                 fatal("do_exec_no_pty: no session");
 426
 427         session_proctitle(s);
 428
 429 #if defined(USE_PAM)
 430         do_pam_session(s->pw->pw_name, NULL);
 431         do_pam_setcred(1);
 432 #endif /* USE_PAM */
 433
 434         /* Fork the child. */
 435         if ((pid = fork()) == 0) {
 436                 /* Child.  Reinitialize the log since the pid has changed. */
 437                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 438
 439                 /*
 440                  * Create a new session and process group since the 4.4BSD
 441                  * setlogin() affects the entire process group.
 442                  */
 443                 if (setsid() < 0)
 444                         error("setsid failed: %.100s", strerror(errno));
 445
 446 #ifdef USE_PIPES
 447                 /*
 448                  * Redirect stdin.  We close the parent side of the socket
 449                  * pair, and make the child side the standard input.
 450                  */
 451                 close(pin[1]);
 452                 if (dup2(pin[0], 0) < 0)
 453                         perror("dup2 stdin");
 454                 close(pin[0]);
 455
 456                 /* Redirect stdout. */
 457                 close(pout[0]);
 458                 if (dup2(pout[1], 1) < 0)
 459                         perror("dup2 stdout");
 460                 close(pout[1]);
 461
 462                 /* Redirect stderr. */
 463                 close(perr[0]);
 464                 if (dup2(perr[1], 2) < 0)
 465                         perror("dup2 stderr");
 466                 close(perr[1]);
 467 #else /* USE_PIPES */
 468                 /*
 469                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 470                  * use the same socket, as some programs (particularly rdist)
 471                  * seem to depend on it.
 472                  */
 473                 close(inout[1]);
 474                 close(err[1]);
 475                 if (dup2(inout[0], 0) < 0)      /* stdin */
 476                         perror("dup2 stdin");
 477                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 478                         perror("dup2 stdout");
 479                 if (dup2(err[0], 2) < 0)        /* stderr */
 480                         perror("dup2 stderr");
 481 #endif /* USE_PIPES */
 482
 483                 /* Do processing for the child (exec command etc). */
 484                 do_child(s, command);
 485                 /* NOTREACHED */
 486         }
 487 #ifdef HAVE_CYGWIN
 488         if (is_winnt)
 489                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 490 #endif
 491         if (pid < 0)
 492                 packet_disconnect("fork failed: %.100s", strerror(errno));
 493         s->pid = pid;
 494         /* Set interactive/non-interactive mode. */
 495         packet_set_interactive(s->display != NULL);
 496 #ifdef USE_PIPES
 497         /* We are the parent.  Close the child sides of the pipes. */
 498         close(pin[0]);
 499         close(pout[1]);
 500         close(perr[1]);
 501
 502         if (compat20) {
 503                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 504         } else {
 505                 /* Enter the interactive session. */
 506                 server_loop(pid, pin[1], pout[0], perr[0]);
 507                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 508         }
 509 #else /* USE_PIPES */
 510         /* We are the parent.  Close the child sides of the socket pairs. */
 511         close(inout[0]);
 512         close(err[0]);
 513
 514         /*
 515          * Enter the interactive session.  Note: server_loop must be able to
 516          * handle the case that fdin and fdout are the same.
 517          */
 518         if (compat20) {
 519                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 520         } else {
 521                 server_loop(pid, inout[1], inout[1], err[1]);
 522                 /* server_loop has closed inout[1] and err[1]. */
 523         }
 524 #endif /* USE_PIPES */
 525 }
 526
 527 /*
 528  * This is called to fork and execute a command when we have a tty.  This
 529  * will call do_child from the child, and server_loop from the parent after
 530  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 531  * lastlog, and other such operations.
 532  */
 533 void
 534 do_exec_pty(Session *s, const char *command)
 535 {
 536         int fdout, ptyfd, ttyfd, ptymaster;
 537         pid_t pid;
 538
 539         if (s == NULL)
 540                 fatal("do_exec_pty: no session");
 541         ptyfd = s->ptyfd;
 542         ttyfd = s->ttyfd;
 543
 544 #if defined(USE_PAM)
 545         do_pam_session(s->pw->pw_name, s->tty);
 546         do_pam_setcred(1);
 547 #endif
 548
 549         /* Fork the child. */
 550         if ((pid = fork()) == 0) {
 551
 552                 /* Child.  Reinitialize the log because the pid has changed. */
 553                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 554                 /* Close the master side of the pseudo tty. */
 555                 close(ptyfd);
 556
 557                 /* Make the pseudo tty our controlling tty. */
 558                 pty_make_controlling_tty(&ttyfd, s->tty);
 559
 560                 /* Redirect stdin from the pseudo tty. */
 561                 if (dup2(ttyfd, fileno(stdin)) < 0)
 562                         error("dup2 stdin failed: %.100s", strerror(errno));
 563
 564                 /* Redirect stdout to the pseudo tty. */
 565                 if (dup2(ttyfd, fileno(stdout)) < 0)
 566                         error("dup2 stdin failed: %.100s", strerror(errno));
 567
 568                 /* Redirect stderr to the pseudo tty. */
 569                 if (dup2(ttyfd, fileno(stderr)) < 0)
 570                         error("dup2 stdin failed: %.100s", strerror(errno));
 571
 572                 /* Close the extra descriptor for the pseudo tty. */
 573                 close(ttyfd);
 574
 575                 /* record login, etc. similar to login(1) */
 576 #ifndef HAVE_OSF_SIA
 577                 if (!(options.use_login && command == NULL))
 578                         do_login(s, command);
 579 # ifdef LOGIN_NEEDS_UTMPX
 580                 else
 581                         do_pre_login(s);
 582 # endif
 583 #endif
 584
 585                 /* Do common processing for the child, such as execing the command. */
 586                 do_child(s, command);
 587                 /* NOTREACHED */
 588         }
 589 #ifdef HAVE_CYGWIN
 590         if (is_winnt)
 591                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 592 #endif
 593         if (pid < 0)
 594                 packet_disconnect("fork failed: %.100s", strerror(errno));
 595         s->pid = pid;
 596
 597         /* Parent.  Close the slave side of the pseudo tty. */
 598         close(ttyfd);
 599
 600         /*
 601          * Create another descriptor of the pty master side for use as the
 602          * standard input.  We could use the original descriptor, but this
 603          * simplifies code in server_loop.  The descriptor is bidirectional.
 604          */
 605         fdout = dup(ptyfd);
 606         if (fdout < 0)
 607                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 608
 609         /* we keep a reference to the pty master */
 610         ptymaster = dup(ptyfd);
 611         if (ptymaster < 0)
 612                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 613         s->ptymaster = ptymaster;
 614
 615         /* Enter interactive session. */
 616         packet_set_interactive(1);
 617         if (compat20) {
 618                 session_set_fds(s, ptyfd, fdout, -1);
 619         } else {
 620                 server_loop(pid, ptyfd, fdout, -1);
 621                 /* server_loop _has_ closed ptyfd and fdout. */
 622         }
 623 }
 624
 625 #ifdef LOGIN_NEEDS_UTMPX
 626 void
 627 do_pre_login(Session *s)
 628 {
 629         socklen_t fromlen;
 630         struct sockaddr_storage from;
 631         pid_t pid = getpid();
 632
 633         /*
 634          * Get IP address of client. If the connection is not a socket, let
 635          * the address be 0.0.0.0.
 636          */
 637         memset(&from, 0, sizeof(from));
 638         if (packet_connection_is_on_socket()) {
 639                 fromlen = sizeof(from);
 640                 if (getpeername(packet_get_connection_in(),
 641                      (struct sockaddr *) & from, &fromlen) < 0) {
 642                         debug("getpeername: %.100s", strerror(errno));
 643                         fatal_cleanup();
 644                 }
 645         }
 646
 647         record_utmp_only(pid, s->tty, s->pw->pw_name,
 648             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 649             (struct sockaddr *)&from);
 650 }
 651 #endif
 652
 653 /*
 654  * This is called to fork and execute a command.  If another command is
 655  * to be forced, execute that instead.
 656  */
 657 void
 658 do_exec(Session *s, const char *command)
 659 {
 660         if (forced_command) {
 661                 original_command = command;
 662                 command = forced_command;
 663                 debug("Forced command '%.900s'", command);
 664         }
 665
 666         if (s->ttyfd != -1)
 667                 do_exec_pty(s, command);
 668         else
 669                 do_exec_no_pty(s, command);
 670
 671         original_command = NULL;
 672 }
 673
 674 /* administrative, login(1)-like work */
 675 void
 676 do_login(Session *s, const char *command)
 677 {
 678         char *time_string;
 679         char hostname[MAXHOSTNAMELEN];
 680         socklen_t fromlen;
 681         struct sockaddr_storage from;
 682         time_t last_login_time;
 683         struct passwd * pw = s->pw;
 684         pid_t pid = getpid();
 685
 686         /*
 687          * Get IP address of client. If the connection is not a socket, let
 688          * the address be 0.0.0.0.
 689          */
 690         memset(&from, 0, sizeof(from));
 691         if (packet_connection_is_on_socket()) {
 692                 fromlen = sizeof(from);
 693                 if (getpeername(packet_get_connection_in(),
 694                      (struct sockaddr *) & from, &fromlen) < 0) {
 695                         debug("getpeername: %.100s", strerror(errno));
 696                         fatal_cleanup();
 697                 }
 698         }
 699
 700         /* Get the time and hostname when the user last logged in. */
 701         if (options.print_lastlog) {
 702                 hostname[0] = '\0';
 703                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 704                     hostname, sizeof(hostname));
 705         }
 706
 707         /* Record that there was a login on that tty from the remote host. */
 708         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 709             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 710             (struct sockaddr *)&from);
 711
 712 #ifdef USE_PAM
 713         /*
 714          * If password change is needed, do it now.
 715          * This needs to occur before the ~/.hushlogin check.
 716          */
 717         if (is_pam_password_change_required()) {
 718                 print_pam_messages();
 719                 do_pam_chauthtok();
 720         }
 721 #endif
 722
 723         if (check_quietlogin(s, command))
 724                 return;
 725
 726 #ifdef USE_PAM
 727         if (!is_pam_password_change_required())
 728                 print_pam_messages();
 729 #endif /* USE_PAM */
 730 #ifdef WITH_AIXAUTHENTICATE
 731         if (aixloginmsg && *aixloginmsg)
 732                 printf("%s\n", aixloginmsg);
 733 #endif /* WITH_AIXAUTHENTICATE */
 734
 735         if (options.print_lastlog && last_login_time != 0) {
 736                 time_string = ctime(&last_login_time);
 737                 if (strchr(time_string, '\n'))
 738                         *strchr(time_string, '\n') = 0;
 739                 if (strcmp(hostname, "") == 0)
 740                         printf("Last login: %s\r\n", time_string);
 741                 else
 742                         printf("Last login: %s from %s\r\n", time_string, hostname);
 743         }
 744
 745         do_motd();
 746 }
 747
 748 /*
 749  * Display the message of the day.
 750  */
 751 void
 752 do_motd(void)
 753 {
 754         FILE *f;
 755         char buf[256];
 756
 757         if (options.print_motd) {
 758 #ifdef HAVE_LOGIN_CAP
 759                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 760                     "/etc/motd"), "r");
 761 #else
 762                 f = fopen("/etc/motd", "r");
 763 #endif
 764                 if (f) {
 765                         while (fgets(buf, sizeof(buf), f))
 766                                 fputs(buf, stdout);
 767                         fclose(f);
 768                 }
 769         }
 770 }
 771
 772
 773 /*
 774  * Check for quiet login, either .hushlogin or command given.
 775  */
 776 int
 777 check_quietlogin(Session *s, const char *command)
 778 {
 779         char buf[256];
 780         struct passwd *pw = s->pw;
 781         struct stat st;
 782
 783         /* Return 1 if .hushlogin exists or a command given. */
 784         if (command != NULL)
 785                 return 1;
 786         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 787 #ifdef HAVE_LOGIN_CAP
 788         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 789                 return 1;
 790 #else
 791         if (stat(buf, &st) >= 0)
 792                 return 1;
 793 #endif
 794         return 0;
 795 }
 796
 797 /*
 798  * Sets the value of the given variable in the environment.  If the variable
 799  * already exists, its value is overriden.
 800  */
 801 static void
 802 child_set_env(char ***envp, u_int *envsizep, const char *name,
 803               const char *value)
 804 {
 805         u_int i, namelen;
 806         char **env;
 807
 808         /*
 809          * Find the slot where the value should be stored.  If the variable
 810          * already exists, we reuse the slot; otherwise we append a new slot
 811          * at the end of the array, expanding if necessary.
 812          */
 813         env = *envp;
 814         namelen = strlen(name);
 815         for (i = 0; env[i]; i++)
 816                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 817                         break;
 818         if (env[i]) {
 819                 /* Reuse the slot. */
 820                 xfree(env[i]);
 821         } else {
 822                 /* New variable.  Expand if necessary. */
 823                 if (i >= (*envsizep) - 1) {
 824                         (*envsizep) += 50;
 825                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 826                 }
 827                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 828                 env[i + 1] = NULL;
 829         }
 830
 831         /* Allocate space and format the variable in the appropriate slot. */
 832         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 833         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 834 }
 835
 836 /*
 837  * Reads environment variables from the given file and adds/overrides them
 838  * into the environment.  If the file does not exist, this does nothing.
 839  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 840  * and assignments of the form name=value.  No other forms are allowed.
 841  */
 842 static void
 843 read_environment_file(char ***env, u_int *envsize,
 844                       const char *filename)
 845 {
 846         FILE *f;
 847         char buf[4096];
 848         char *cp, *value;
 849
 850         f = fopen(filename, "r");
 851         if (!f)
 852                 return;
 853
 854         while (fgets(buf, sizeof(buf), f)) {
 855                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 856                         ;
 857                 if (!*cp || *cp == '#' || *cp == '\n')
 858                         continue;
 859                 if (strchr(cp, '\n'))
 860                         *strchr(cp, '\n') = '\0';
 861                 value = strchr(cp, '=');
 862                 if (value == NULL) {
 863                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 864                         continue;
 865                 }
 866                 /*
 867                  * Replace the equals sign by nul, and advance value to
 868                  * the value string.
 869                  */
 870                 *value = '\0';
 871                 value++;
 872                 child_set_env(env, envsize, cp, value);
 873         }
 874         fclose(f);
 875 }
 876
 877 #ifdef USE_PAM
 878 /*
 879  * Sets any environment variables which have been specified by PAM
 880  */
 881 void do_pam_environment(char ***env, u_int *envsize)
 882 {
 883         char *equals, var_name[512], var_val[512];
 884         char **pam_env;
 885         int i;
 886
 887         if ((pam_env = fetch_pam_environment()) == NULL)
 888                 return;
 889
 890         for(i = 0; pam_env[i] != NULL; i++) {
 891                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 892                         continue;
 893
 894                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 895                         memset(var_name, '\0', sizeof(var_name));
 896                         memset(var_val, '\0', sizeof(var_val));
 897
 898                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 899                         strcpy(var_val, equals + 1);
 900
 901                         debug3("PAM environment: %s=%s", var_name, var_val);
 902
 903                         child_set_env(env, envsize, var_name, var_val);
 904                 }
 905         }
 906 }
 907 #endif /* USE_PAM */
 908
 909 #ifdef HAVE_CYGWIN
 910 void copy_environment(char ***env, u_int *envsize)
 911 {
 912         char *equals, var_name[512], var_val[512];
 913         int i;
 914
 915         for(i = 0; environ[i] != NULL; i++) {
 916                 if ((equals = strstr(environ[i], "=")) == NULL)
 917                         continue;
 918
 919                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 920                         memset(var_name, '\0', sizeof(var_name));
 921                         memset(var_val, '\0', sizeof(var_val));
 922
 923                         strncpy(var_name, environ[i], equals - environ[i]);
 924                         strcpy(var_val, equals + 1);
 925
 926                         debug3("Copy environment: %s=%s", var_name, var_val);
 927
 928                         child_set_env(env, envsize, var_name, var_val);
 929                 }
 930         }
 931 }
 932 #endif
 933
 934 #if defined(HAVE_GETUSERATTR)
 935 /*
 936  * AIX-specific login initialisation
 937  */
 938 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 939 {
 940         struct rlimit rlim;
 941         int slim, hlim;
 942
 943         getrlimit(resource, &rlim);
 944
 945         slim = 0;
 946         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 947                 if (slim < 0) {
 948                         rlim.rlim_cur = RLIM_INFINITY;
 949                 } else if (slim != 0) {
 950                         /* See the wackiness below */
 951                         if (rlim.rlim_cur == slim * mult)
 952                                 slim = 0;
 953                         else
 954                                 rlim.rlim_cur = slim * mult;
 955                 }
 956         }
 957
 958         hlim = 0;
 959         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 960                 if (hlim < 0) {
 961                         rlim.rlim_max = RLIM_INFINITY;
 962                 } else if (hlim != 0) {
 963                         rlim.rlim_max = hlim * mult;
 964                 }
 965         }
 966
 967         /*
 968          * XXX For cpu and fsize the soft limit is set to the hard limit
 969          * if the hard limit is left at its default value and the soft limit
 970          * is changed from its default value, either by requesting it
 971          * (slim == 0) or by setting it to the current default.  At least
 972          * that's how rlogind does it.  If you're confused you're not alone.
 973          * Bug or feature? AIX 4.3.1.2
 974          */
 975         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 976             && hlim == 0 && slim != 0)
 977                 rlim.rlim_max = rlim.rlim_cur;
 978         /* A specified hard limit limits the soft limit */
 979         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 980                 rlim.rlim_cur = rlim.rlim_max;
 981         /* A soft limit can increase a hard limit */
 982         else if (rlim.rlim_cur > rlim.rlim_max)
 983                 rlim.rlim_max = rlim.rlim_cur;
 984
 985         if (setrlimit(resource, &rlim) != 0)
 986                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 987 }
 988
 989 void set_limits_from_userattr(char *user)
 990 {
 991         int mask;
 992         char buf[16];
 993
 994         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 995         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 996         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 997         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 998         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 999         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
1000 #if defined(S_UNOFILE)
1001         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1002 #endif
1003
1004         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1005                 /* Convert decimal to octal */
1006                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1007                 if (sscanf(buf, "%o", &mask) == 1)
1008                         umask(mask);
1009         }
1010 }
1011 #endif /* defined(HAVE_GETUSERATTR) */
1012
1013 /*
1014  * Performs common processing for the child, such as setting up the
1015  * environment, closing extra file descriptors, setting the user and group
1016  * ids, and executing the command or shell.
1017  */
1018 void
1019 do_child(Session *s, const char *command)
1020 {
1021         const char *shell, *hostname = NULL, *cp = NULL;
1022         struct passwd *pw = s->pw;
1023         char buf[256];
1024         char cmd[1024];
1025         FILE *f = NULL;
1026         u_int envsize, i;
1027         char **env;
1028         extern char **environ;
1029         struct stat st;
1030         char *argv[10];
1031         int do_xauth;
1032 #ifdef WITH_IRIX_PROJECT
1033         prid_t projid;
1034 #endif /* WITH_IRIX_PROJECT */
1035 #ifdef WITH_IRIX_JOBS
1036         jid_t jid = 0;
1037 #else
1038 #ifdef WITH_IRIX_ARRAY
1039         int jid = 0;
1040 #endif /* WITH_IRIX_ARRAY */
1041 #endif /* WITH_IRIX_JOBS */
1042
1043         do_xauth =
1044             s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1045
1046         /* remove hostkey from the child's memory */
1047         destroy_sensitive_data();
1048
1049         /* login(1) is only called if we execute the login shell */
1050         if (options.use_login && command != NULL)
1051                 options.use_login = 0;
1052
1053 #if !defined(HAVE_OSF_SIA)
1054         if (!options.use_login) {
1055 # ifdef HAVE_LOGIN_CAP
1056                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1057                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1058                             _PATH_NOLOGIN), "r");
1059 # else /* HAVE_LOGIN_CAP */
1060                 if (pw->pw_uid)
1061                         f = fopen(_PATH_NOLOGIN, "r");
1062 # endif /* HAVE_LOGIN_CAP */
1063                 if (f) {
1064                         /* /etc/nologin exists.  Print its contents and exit. */
1065                         while (fgets(buf, sizeof(buf), f))
1066                                 fputs(buf, stderr);
1067                         fclose(f);
1068                         exit(254);
1069                 }
1070         }
1071 #endif /* HAVE_OSF_SIA */
1072
1073         /* Set login name, uid, gid, and groups. */
1074         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1075            switch, so we let login(1) to this for us. */
1076         if (!options.use_login) {
1077 #ifdef HAVE_OSF_SIA
1078                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1079                 if (!check_quietlogin(s, command))
1080                         do_motd();
1081 #else /* HAVE_OSF_SIA */
1082 #ifdef HAVE_CYGWIN
1083                 if (is_winnt) {
1084 #else
1085                 if (getuid() == 0 || geteuid() == 0) {
1086 #endif
1087 # ifdef HAVE_GETUSERATTR
1088                         set_limits_from_userattr(pw->pw_name);
1089 # endif /* HAVE_GETUSERATTR */
1090 # ifdef HAVE_LOGIN_CAP
1091                         if (setusercontext(lc, pw, pw->pw_uid,
1092                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1093                                 perror("unable to set user context");
1094                                 exit(1);
1095                         }
1096 # else /* HAVE_LOGIN_CAP */
1097 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1098                         /* Sets login uid for accounting */
1099                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1100                                 error("setluid: %s", strerror(errno));
1101 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1102
1103                         if (setlogin(pw->pw_name) < 0)
1104                                 error("setlogin failed: %s", strerror(errno));
1105                         if (setgid(pw->pw_gid) < 0) {
1106                                 perror("setgid");
1107                                 exit(1);
1108                         }
1109                         /* Initialize the group list. */
1110                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1111                                 perror("initgroups");
1112                                 exit(1);
1113                         }
1114                         endgrent();
1115 #  ifdef USE_PAM
1116                         /*
1117                          * PAM credentials may take the form of
1118                          * supplementary groups. These will have been
1119                          * wiped by the above initgroups() call.
1120                          * Reestablish them here.
1121                          */
1122                         do_pam_setcred(0);
1123 #  endif /* USE_PAM */
1124 #  ifdef WITH_IRIX_JOBS
1125                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1126                         if (jid == -1) {
1127                                 fatal("Failed to create job container: %.100s",
1128                                       strerror(errno));
1129                         }
1130 #  endif /* WITH_IRIX_JOBS */
1131 #  ifdef WITH_IRIX_ARRAY
1132                         /* initialize array session */
1133                         if (jid == 0) {
1134                                 if (newarraysess() != 0)
1135                                         fatal("Failed to set up new array session: %.100s",
1136                                               strerror(errno));
1137                         }
1138 #  endif /* WITH_IRIX_ARRAY */
1139 #  ifdef WITH_IRIX_PROJECT
1140                         /* initialize irix project info */
1141                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1142                           debug("Failed to get project id, using projid 0");
1143                           projid = 0;
1144                         }
1145                         if (setprid(projid))
1146                           fatal("Failed to initialize project %d for %s: %.100s",
1147                                 (int)projid, pw->pw_name, strerror(errno));
1148 #  endif /* WITH_IRIX_PROJECT */
1149 #ifdef WITH_IRIX_AUDIT
1150                         if (sysconf(_SC_AUDIT)) {
1151                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1152                                 if (satsetid(pw->pw_uid))
1153                                         debug("error setting satid: %.100s", strerror(errno));
1154                         }
1155 #endif /* WITH_IRIX_AUDIT */
1156
1157 #ifdef _AIX
1158                         /*
1159                          * AIX has a "usrinfo" area where logname and
1160                          * other stuff is stored - a few applications
1161                          * actually use this and die if it's not set
1162                          */
1163                         if (s->ttyfd == -1)
1164                                 s->tty[0] = '\0';
1165                         cp = xmalloc(22 + strlen(s->tty) +
1166                             2 * strlen(pw->pw_name));
1167                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1168                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1169                         if (usrinfo(SETUINFO, cp, i) == -1)
1170                                 fatal("Couldn't set usrinfo: %s",
1171                                     strerror(errno));
1172                         debug3("AIX/UsrInfo: set len %d", i);
1173                         xfree(cp);
1174 #endif
1175
1176                         /* Permanently switch to the desired uid. */
1177                         permanently_set_uid(pw);
1178 # endif /* HAVE_LOGIN_CAP */
1179                 }
1180 #endif /* HAVE_OSF_SIA */
1181
1182 #ifdef HAVE_CYGWIN
1183                 if (is_winnt)
1184 #endif
1185                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1186                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1187         }
1188         /*
1189          * Get the shell from the password data.  An empty shell field is
1190          * legal, and means /bin/sh.
1191          */
1192         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1193 #ifdef HAVE_LOGIN_CAP
1194         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1195 #endif
1196
1197 #ifdef AFS
1198         /* Try to get AFS tokens for the local cell. */
1199         if (k_hasafs()) {
1200                 char cell[64];
1201
1202                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1203                         krb_afslog(cell, 0);
1204
1205                 krb_afslog(0, 0);
1206         }
1207 #endif /* AFS */
1208
1209         /* Initialize the environment. */
1210         envsize = 100;
1211         env = xmalloc(envsize * sizeof(char *));
1212         env[0] = NULL;
1213
1214 #ifdef HAVE_CYGWIN
1215         /*
1216          * The Windows environment contains some setting which are
1217          * important for a running system. They must not be dropped.
1218          */
1219         copy_environment(&env, &envsize);
1220 #endif
1221
1222         if (!options.use_login) {
1223                 /* Set basic environment. */
1224                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1225                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1226                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1227 #ifdef HAVE_LOGIN_CAP
1228                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1229                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1230 #else /* HAVE_LOGIN_CAP */
1231 # ifndef HAVE_CYGWIN
1232                 /*
1233                  * There's no standard path on Windows. The path contains
1234                  * important components pointing to the system directories,
1235                  * needed for loading shared libraries. So the path better
1236                  * remains intact here.
1237                  */
1238                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1239 # endif /* HAVE_CYGWIN */
1240 #endif /* HAVE_LOGIN_CAP */
1241
1242                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1243                          _PATH_MAILDIR, pw->pw_name);
1244                 child_set_env(&env, &envsize, "MAIL", buf);
1245
1246                 /* Normal systems set SHELL by default. */
1247                 child_set_env(&env, &envsize, "SHELL", shell);
1248         }
1249         if (getenv("TZ"))
1250                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1251
1252         /* Set custom environment options from RSA authentication. */
1253         while (custom_environment) {
1254                 struct envstring *ce = custom_environment;
1255                 char *s = ce->s;
1256                 int i;
1257                 for (i = 0; s[i] != '=' && s[i]; i++);
1258                 if (s[i] == '=') {
1259                         s[i] = 0;
1260                         child_set_env(&env, &envsize, s, s + i + 1);
1261                 }
1262                 custom_environment = ce->next;
1263                 xfree(ce->s);
1264                 xfree(ce);
1265         }
1266
1267         snprintf(buf, sizeof buf, "%.50s %d %d",
1268                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1269         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1270
1271         if (s->ttyfd != -1)
1272                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1273         if (s->term)
1274                 child_set_env(&env, &envsize, "TERM", s->term);
1275         if (s->display)
1276                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1277         if (original_command)
1278                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1279                     original_command);
1280
1281 #ifdef _AIX
1282         if ((cp = getenv("AUTHSTATE")) != NULL)
1283                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1284         if ((cp = getenv("KRB5CCNAME")) != NULL)
1285                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1286         read_environment_file(&env, &envsize, "/etc/environment");
1287 #endif
1288 #ifdef KRB4
1289         if (s->authctxt->krb4_ticket_file)
1290                 child_set_env(&env, &envsize, "KRBTKFILE",
1291                     s->authctxt->krb4_ticket_file);
1292 #endif
1293 #ifdef KRB5
1294         if (s->authctxt->krb5_ticket_file)
1295                 child_set_env(&env, &envsize, "KRB5CCNAME",
1296                     s->authctxt->krb5_ticket_file);
1297 #endif
1298 #ifdef USE_PAM
1299         /* Pull in any environment variables that may have been set by PAM. */
1300         do_pam_environment(&env, &envsize);
1301 #endif /* USE_PAM */
1302
1303         if (auth_get_socket_name() != NULL)
1304                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1305                               auth_get_socket_name());
1306
1307         /* read $HOME/.ssh/environment. */
1308         if (!options.use_login) {
1309                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1310                     pw->pw_dir);
1311                 read_environment_file(&env, &envsize, buf);
1312         }
1313         if (debug_flag) {
1314                 /* dump the environment */
1315                 fprintf(stderr, "Environment:\n");
1316                 for (i = 0; env[i]; i++)
1317                         fprintf(stderr, "  %.200s\n", env[i]);
1318         }
1319         /* we have to stash the hostname before we close our socket. */
1320         if (options.use_login)
1321                 hostname = get_remote_name_or_ip(utmp_len,
1322                     options.reverse_mapping_check);
1323         /*
1324          * Close the connection descriptors; note that this is the child, and
1325          * the server will still have the socket open, and it is important
1326          * that we do not shutdown it.  Note that the descriptors cannot be
1327          * closed before building the environment, as we call
1328          * get_remote_ipaddr there.
1329          */
1330         if (packet_get_connection_in() == packet_get_connection_out())
1331                 close(packet_get_connection_in());
1332         else {
1333                 close(packet_get_connection_in());
1334                 close(packet_get_connection_out());
1335         }
1336         /*
1337          * Close all descriptors related to channels.  They will still remain
1338          * open in the parent.
1339          */
1340         /* XXX better use close-on-exec? -markus */
1341         channel_close_all();
1342
1343         /*
1344          * Close any extra file descriptors.  Note that there may still be
1345          * descriptors left by system functions.  They will be closed later.
1346          */
1347         endpwent();
1348
1349         /*
1350          * Close any extra open file descriptors so that we don\'t have them
1351          * hanging around in clients.  Note that we want to do this after
1352          * initgroups, because at least on Solaris 2.3 it leaves file
1353          * descriptors open.
1354          */
1355         for (i = 3; i < 64; i++)
1356                 close(i);
1357
1358         /* Change current directory to the user\'s home directory. */
1359         if (chdir(pw->pw_dir) < 0) {
1360                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1361                         pw->pw_dir, strerror(errno));
1362 #ifdef HAVE_LOGIN_CAP
1363                 if (login_getcapbool(lc, "requirehome", 0))
1364                         exit(1);
1365 #endif
1366         }
1367
1368         /*
1369          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1370          * xauth are run in the proper environment.
1371          */
1372         environ = env;
1373
1374         /*
1375          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1376          * in this order).
1377          */
1378         if (!options.use_login) {
1379                 /* ignore _PATH_SSH_USER_RC for subsystems */
1380                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1381                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1382                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1383                         if (debug_flag)
1384                                 fprintf(stderr, "Running %s\n", cmd);
1385                         f = popen(cmd, "w");
1386                         if (f) {
1387                                 if (do_xauth)
1388                                         fprintf(f, "%s %s\n", s->auth_proto,
1389                                             s->auth_data);
1390                                 pclose(f);
1391                         } else
1392                                 fprintf(stderr, "Could not run %s\n",
1393                                     _PATH_SSH_USER_RC);
1394                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1395                         if (debug_flag)
1396                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1397                                     _PATH_SSH_SYSTEM_RC);
1398                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1399                         if (f) {
1400                                 if (do_xauth)
1401                                         fprintf(f, "%s %s\n", s->auth_proto,
1402                                             s->auth_data);
1403                                 pclose(f);
1404                         } else
1405                                 fprintf(stderr, "Could not run %s\n",
1406                                     _PATH_SSH_SYSTEM_RC);
1407                 } else if (do_xauth && options.xauth_location != NULL) {
1408                         /* Add authority data to .Xauthority if appropriate. */
1409                         char *screen = strchr(s->display, ':');
1410
1411                         if (debug_flag) {
1412                                 fprintf(stderr,
1413                                     "Running %.100s add "
1414                                     "%.100s %.100s %.100s\n",
1415                                     options.xauth_location, s->display,
1416                                     s->auth_proto, s->auth_data);
1417                                 if (screen != NULL)
1418                                         fprintf(stderr,
1419                                             "Adding %.*s/unix%s %s %s\n",
1420                                             (int)(screen - s->display),
1421                                             s->display, screen,
1422                                             s->auth_proto, s->auth_data);
1423                         }
1424                         snprintf(cmd, sizeof cmd, "%s -q -",
1425                             options.xauth_location);
1426                         f = popen(cmd, "w");
1427                         if (f) {
1428                                 fprintf(f, "add %s %s %s\n", s->display,
1429                                     s->auth_proto, s->auth_data);
1430                                 if (screen != NULL)
1431                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1432                                             (int)(screen - s->display),
1433                                             s->display, screen,
1434                                             s->auth_proto,
1435                                             s->auth_data);
1436                                 pclose(f);
1437                         } else {
1438                                 fprintf(stderr, "Could not run %s\n",
1439                                     cmd);
1440                         }
1441                 }
1442                 /* Get the last component of the shell name. */
1443                 cp = strrchr(shell, '/');
1444                 if (cp)
1445                         cp++;
1446                 else
1447                         cp = shell;
1448         }
1449
1450         /* restore SIGPIPE for child */
1451         signal(SIGPIPE,  SIG_DFL);
1452
1453         /*
1454          * If we have no command, execute the shell.  In this case, the shell
1455          * name to be passed in argv[0] is preceded by '-' to indicate that
1456          * this is a login shell.
1457          */
1458         if (!command) {
1459                 if (!options.use_login) {
1460                         char buf[256];
1461
1462                         /* Start the shell.  Set initial character to '-'. */
1463                         buf[0] = '-';
1464                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1465                         buf[sizeof(buf) - 1] = 0;
1466
1467                         /* Execute the shell. */
1468                         argv[0] = buf;
1469                         argv[1] = NULL;
1470                         execve(shell, argv, env);
1471
1472                         /* Executing the shell failed. */
1473                         perror(shell);
1474                         exit(1);
1475
1476                 } else {
1477                         /* Launch login(1). */
1478
1479                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1480 #ifdef LOGIN_NEEDS_TERM
1481                              s->term? s->term : "unknown",
1482 #endif
1483                              "-p", "-f", "--", pw->pw_name, (char *)NULL);
1484
1485                         /* Login couldn't be executed, die. */
1486
1487                         perror("login");
1488                         exit(1);
1489                 }
1490         }
1491         /*
1492          * Execute the command using the user's shell.  This uses the -c
1493          * option to execute the command.
1494          */
1495         argv[0] = (char *) cp;
1496         argv[1] = "-c";
1497         argv[2] = (char *) command;
1498         argv[3] = NULL;
1499         execve(shell, argv, env);
1500         perror(shell);
1501         exit(1);
1502 }
1503
1504 Session *
1505 session_new(void)
1506 {
1507         int i;
1508         static int did_init = 0;
1509         if (!did_init) {
1510                 debug("session_new: init");
1511                 for(i = 0; i < MAX_SESSIONS; i++) {
1512                         sessions[i].used = 0;
1513                 }
1514                 did_init = 1;
1515         }
1516         for(i = 0; i < MAX_SESSIONS; i++) {
1517                 Session *s = &sessions[i];
1518                 if (! s->used) {
1519                         memset(s, 0, sizeof(*s));
1520                         s->chanid = -1;
1521                         s->ptyfd = -1;
1522                         s->ttyfd = -1;
1523                         s->used = 1;
1524                         s->self = i;
1525                         debug("session_new: session %d", i);
1526                         return s;
1527                 }
1528         }
1529         return NULL;
1530 }
1531
1532 static void
1533 session_dump(void)
1534 {
1535         int i;
1536         for(i = 0; i < MAX_SESSIONS; i++) {
1537                 Session *s = &sessions[i];
1538                 debug("dump: used %d session %d %p channel %d pid %d",
1539                     s->used,
1540                     s->self,
1541                     s,
1542                     s->chanid,
1543                     s->pid);
1544         }
1545 }
1546
1547 int
1548 session_open(Authctxt *authctxt, int chanid)
1549 {
1550         Session *s = session_new();
1551         debug("session_open: channel %d", chanid);
1552         if (s == NULL) {
1553                 error("no more sessions");
1554                 return 0;
1555         }
1556         s->authctxt = authctxt;
1557         s->pw = authctxt->pw;
1558         if (s->pw == NULL)
1559                 fatal("no user for session %d", s->self);
1560         debug("session_open: session %d: link with channel %d", s->self, chanid);
1561         s->chanid = chanid;
1562         return 1;
1563 }
1564
1565 static Session *
1566 session_by_channel(int id)
1567 {
1568         int i;
1569         for(i = 0; i < MAX_SESSIONS; i++) {
1570                 Session *s = &sessions[i];
1571                 if (s->used && s->chanid == id) {
1572                         debug("session_by_channel: session %d channel %d", i, id);
1573                         return s;
1574                 }
1575         }
1576         debug("session_by_channel: unknown channel %d", id);
1577         session_dump();
1578         return NULL;
1579 }
1580
1581 static Session *
1582 session_by_pid(pid_t pid)
1583 {
1584         int i;
1585         debug("session_by_pid: pid %d", pid);
1586         for(i = 0; i < MAX_SESSIONS; i++) {
1587                 Session *s = &sessions[i];
1588                 if (s->used && s->pid == pid)
1589                         return s;
1590         }
1591         error("session_by_pid: unknown pid %d", pid);
1592         session_dump();
1593         return NULL;
1594 }
1595
1596 static int
1597 session_window_change_req(Session *s)
1598 {
1599         s->col = packet_get_int();
1600         s->row = packet_get_int();
1601         s->xpixel = packet_get_int();
1602         s->ypixel = packet_get_int();
1603         packet_done();
1604         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1605         return 1;
1606 }
1607
1608 static int
1609 session_pty_req(Session *s)
1610 {
1611         u_int len;
1612         int n_bytes;
1613
1614         if (no_pty_flag) {
1615                 debug("Allocating a pty not permitted for this authentication.");
1616                 return 0;
1617         }
1618         if (s->ttyfd != -1) {
1619                 packet_disconnect("Protocol error: you already have a pty.");
1620                 return 0;
1621         }
1622
1623         s->term = packet_get_string(&len);
1624
1625         if (compat20) {
1626                 s->col = packet_get_int();
1627                 s->row = packet_get_int();
1628         } else {
1629                 s->row = packet_get_int();
1630                 s->col = packet_get_int();
1631         }
1632         s->xpixel = packet_get_int();
1633         s->ypixel = packet_get_int();
1634
1635         if (strcmp(s->term, "") == 0) {
1636                 xfree(s->term);
1637                 s->term = NULL;
1638         }
1639
1640         /* Allocate a pty and open it. */
1641         debug("Allocating pty.");
1642         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1643                 if (s->term)
1644                         xfree(s->term);
1645                 s->term = NULL;
1646                 s->ptyfd = -1;
1647                 s->ttyfd = -1;
1648                 error("session_pty_req: session %d alloc failed", s->self);
1649                 return 0;
1650         }
1651         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1652
1653         /* for SSH1 the tty modes length is not given */
1654         if (!compat20)
1655                 n_bytes = packet_remaining();
1656         tty_parse_modes(s->ttyfd, &n_bytes);
1657
1658         /*
1659          * Add a cleanup function to clear the utmp entry and record logout
1660          * time in case we call fatal() (e.g., the connection gets closed).
1661          */
1662         fatal_add_cleanup(session_pty_cleanup, (void *)s);
1663         pty_setowner(s->pw, s->tty);
1664
1665         /* Set window size from the packet. */
1666         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1667
1668         packet_done();
1669         session_proctitle(s);
1670         return 1;
1671 }
1672
1673 static int
1674 session_subsystem_req(Session *s)
1675 {
1676         u_int len;
1677         int success = 0;
1678         char *subsys = packet_get_string(&len);
1679         int i;
1680
1681         packet_done();
1682         log("subsystem request for %s", subsys);
1683
1684         for (i = 0; i < options.num_subsystems; i++) {
1685                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1686                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1687                         s->is_subsystem = 1;
1688                         do_exec_no_pty(s, options.subsystem_command[i]);
1689                         success = 1;
1690                 }
1691         }
1692
1693         if (!success)
1694                 log("subsystem request for %s failed, subsystem not found", subsys);
1695
1696         xfree(subsys);
1697         return success;
1698 }
1699
1700 static int
1701 session_x11_req(Session *s)
1702 {
1703         int success;
1704
1705         s->single_connection = packet_get_char();
1706         s->auth_proto = packet_get_string(NULL);
1707         s->auth_data = packet_get_string(NULL);
1708         s->screen = packet_get_int();
1709         packet_done();
1710
1711         success = session_setup_x11fwd(s);
1712         if (!success) {
1713                 xfree(s->auth_proto);
1714                 xfree(s->auth_data);
1715                 s->auth_proto = NULL;
1716                 s->auth_data = NULL;
1717         }
1718         return success;
1719 }
1720
1721 static int
1722 session_shell_req(Session *s)
1723 {
1724         packet_done();
1725         do_exec(s, NULL);
1726         return 1;
1727 }
1728
1729 static int
1730 session_exec_req(Session *s)
1731 {
1732         u_int len;
1733         char *command = packet_get_string(&len);
1734         packet_done();
1735         do_exec(s, command);
1736         xfree(command);
1737         return 1;
1738 }
1739
1740 static int
1741 session_auth_agent_req(Session *s)
1742 {
1743         static int called = 0;
1744         packet_done();
1745         if (no_agent_forwarding_flag) {
1746                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1747                 return 0;
1748         }
1749         if (called) {
1750                 return 0;
1751         } else {
1752                 called = 1;
1753                 return auth_input_request_forwarding(s->pw);
1754         }
1755 }
1756
1757 void
1758 session_input_channel_req(int id, void *arg)
1759 {
1760         u_int len;
1761         int reply;
1762         int success = 0;
1763         char *rtype;
1764         Session *s;
1765         Channel *c;
1766
1767         rtype = packet_get_string(&len);
1768         reply = packet_get_char();
1769
1770         s = session_by_channel(id);
1771         if (s == NULL)
1772                 fatal("session_input_channel_req: channel %d: no session", id);
1773         c = channel_lookup(id);
1774         if (c == NULL)
1775                 fatal("session_input_channel_req: channel %d: bad channel", id);
1776
1777         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1778             s->self, id, rtype, reply);
1779
1780         /*
1781          * a session is in LARVAL state until a shell, a command
1782          * or a subsystem is executed
1783          */
1784         if (c->type == SSH_CHANNEL_LARVAL) {
1785                 if (strcmp(rtype, "shell") == 0) {
1786                         success = session_shell_req(s);
1787                 } else if (strcmp(rtype, "exec") == 0) {
1788                         success = session_exec_req(s);
1789                 } else if (strcmp(rtype, "pty-req") == 0) {
1790                         success =  session_pty_req(s);
1791                 } else if (strcmp(rtype, "x11-req") == 0) {
1792                         success = session_x11_req(s);
1793                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1794                         success = session_auth_agent_req(s);
1795                 } else if (strcmp(rtype, "subsystem") == 0) {
1796                         success = session_subsystem_req(s);
1797                 }
1798         }
1799         if (strcmp(rtype, "window-change") == 0) {
1800                 success = session_window_change_req(s);
1801         }
1802
1803         if (reply) {
1804                 packet_start(success ?
1805                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1806                 packet_put_int(c->remote_id);
1807                 packet_send();
1808         }
1809         xfree(rtype);
1810 }
1811
1812 void
1813 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1814 {
1815         if (!compat20)
1816                 fatal("session_set_fds: called for proto != 2.0");
1817         /*
1818          * now that have a child and a pipe to the child,
1819          * we can activate our channel and register the fd's
1820          */
1821         if (s->chanid == -1)
1822                 fatal("no channel for session %d", s->self);
1823         channel_set_fds(s->chanid,
1824             fdout, fdin, fderr,
1825             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1826             1);
1827 }
1828
1829 /*
1830  * Function to perform pty cleanup. Also called if we get aborted abnormally
1831  * (e.g., due to a dropped connection).
1832  */
1833 static void
1834 session_pty_cleanup(void *session)
1835 {
1836         Session *s = session;
1837
1838         if (s == NULL) {
1839                 error("session_pty_cleanup: no session");
1840                 return;
1841         }
1842         if (s->ttyfd == -1)
1843                 return;
1844
1845         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1846
1847         /* Record that the user has logged out. */
1848         if (s->pid != 0)
1849                 record_logout(s->pid, s->tty);
1850
1851         /* Release the pseudo-tty. */
1852         pty_release(s->tty);
1853
1854         /*
1855          * Close the server side of the socket pairs.  We must do this after
1856          * the pty cleanup, so that another process doesn't get this pty
1857          * while we're still cleaning up.
1858          */
1859         if (close(s->ptymaster) < 0)
1860                 error("close(s->ptymaster): %s", strerror(errno));
1861 }
1862
1863 static void
1864 session_exit_message(Session *s, int status)
1865 {
1866         Channel *c;
1867         if (s == NULL)
1868                 fatal("session_close: no session");
1869         c = channel_lookup(s->chanid);
1870         if (c == NULL)
1871                 fatal("session_exit_message: session %d: no channel %d",
1872                     s->self, s->chanid);
1873         debug("session_exit_message: session %d channel %d pid %d",
1874             s->self, s->chanid, s->pid);
1875
1876         if (WIFEXITED(status)) {
1877                 channel_request_start(s->chanid,
1878                     "exit-status", 0);
1879                 packet_put_int(WEXITSTATUS(status));
1880                 packet_send();
1881         } else if (WIFSIGNALED(status)) {
1882                 channel_request_start(s->chanid,
1883                     "exit-signal", 0);
1884                 packet_put_int(WTERMSIG(status));
1885 #ifdef WCOREDUMP
1886                 packet_put_char(WCOREDUMP(status));
1887 #else /* WCOREDUMP */
1888                 packet_put_char(0);
1889 #endif /* WCOREDUMP */
1890                 packet_put_cstring("");
1891                 packet_put_cstring("");
1892                 packet_send();
1893         } else {
1894                 /* Some weird exit cause.  Just exit. */
1895                 packet_disconnect("wait returned status %04x.", status);
1896         }
1897
1898         /* disconnect channel */
1899         debug("session_exit_message: release channel %d", s->chanid);
1900         channel_cancel_cleanup(s->chanid);
1901         /*
1902          * emulate a write failure with 'chan_write_failed', nobody will be
1903          * interested in data we write.
1904          * Note that we must not call 'chan_read_failed', since there could
1905          * be some more data waiting in the pipe.
1906          */
1907         if (c->ostate != CHAN_OUTPUT_CLOSED)
1908                 chan_write_failed(c);
1909         s->chanid = -1;
1910 }
1911
1912 static void
1913 session_close(Session *s)
1914 {
1915         debug("session_close: session %d pid %d", s->self, s->pid);
1916         if (s->ttyfd != -1) {
1917                 fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1918                 session_pty_cleanup(s);
1919         }
1920         if (s->term)
1921                 xfree(s->term);
1922         if (s->display)
1923                 xfree(s->display);
1924         if (s->auth_data)
1925                 xfree(s->auth_data);
1926         if (s->auth_proto)
1927                 xfree(s->auth_proto);
1928         s->used = 0;
1929         session_proctitle(s);
1930 }
1931
1932 void
1933 session_close_by_pid(pid_t pid, int status)
1934 {
1935         Session *s = session_by_pid(pid);
1936         if (s == NULL) {
1937                 debug("session_close_by_pid: no session for pid %d", pid);
1938                 return;
1939         }
1940         if (s->chanid != -1)
1941                 session_exit_message(s, status);
1942         session_close(s);
1943 }
1944
1945 int
1946 session_have_children(void)
1947 {
1948         int i;
1949
1950         for(i = 0; i < MAX_SESSIONS; i++) {
1951                 Session *s = &sessions[i];
1952                 if (s->used && s->pid != -1) {
1953                         debug("session_have_children: id %d pid %d", i, s->pid);
1954                         return 1;
1955                 }
1956         }
1957         debug("session_have_children: no more children");
1958         return 0;
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(authctxt);
2056 }