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 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 1.79 2001/06/03 14:55:39 markus 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         pid_t   pid;
 104         /* tty */
 105         char    *term;
 106         int     ptyfd, ttyfd, ptymaster;
 107         int     row, col, xpixel, ypixel;
 108         char    tty[TTYSZ];
 109         /* X11 */
 110         char    *display;
 111         int     screen;
 112         char    *auth_proto;
 113         char    *auth_data;
 114         int     single_connection;
 115         /* proto 2 */
 116         int     chanid;
 117         int     is_subsystem;
 118 };
 119
 120 /* func */
 121
 122 Session *session_new(void);
 123 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 124 void    session_pty_cleanup(Session *s);
 125 void    session_proctitle(Session *s);
 126 void    do_exec_pty(Session *s, const char *command);
 127 void    do_exec_no_pty(Session *s, const char *command);
 128 void    do_login(Session *s, const char *command);
 129 #ifdef LOGIN_NEEDS_UTMPX
 130 void    do_pre_login(Session *s);
 131 #endif
 132 void    do_child(Session *s, const char *command);
 133 void    do_motd(void);
 134 int     check_quietlogin(Session *s, const char *command);
 135 void    xauthfile_cleanup_proc(void *ignore);
 136
 137 void    do_authenticated1(Authctxt *authctxt);
 138 void    do_authenticated2(Authctxt *authctxt);
 139
 140 /* import */
 141 extern ServerOptions options;
 142 extern char *__progname;
 143 extern int log_stderr;
 144 extern int debug_flag;
 145 extern u_int utmp_len;
 146 extern int startup_pipe;
 147 extern void destroy_sensitive_data(void);
 148
 149 /* Local Xauthority file. */
 150 static char *xauthfile;
 151
 152 /* original command from peer. */
 153 char *original_command = NULL;
 154
 155 /* data */
 156 #define MAX_SESSIONS 10
 157 Session sessions[MAX_SESSIONS];
 158
 159 #ifdef WITH_AIXAUTHENTICATE
 160 /* AIX's lastlogin message, set in auth1.c */
 161 char *aixloginmsg;
 162 #endif /* WITH_AIXAUTHENTICATE */
 163
 164 #ifdef HAVE_LOGIN_CAP
 165 static login_cap_t *lc;
 166 #endif
 167
 168 void
 169 do_authenticated(Authctxt *authctxt)
 170 {
 171         /*
 172          * Cancel the alarm we set to limit the time taken for
 173          * authentication.
 174          */
 175         alarm(0);
 176         if (startup_pipe != -1) {
 177                 close(startup_pipe);
 178                 startup_pipe = -1;
 179         }
 180 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 181         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 182                 error("unable to get login class");
 183                 return;
 184         }
 185 #ifdef BSD_AUTH
 186         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 187                 packet_disconnect("Approval failure for %s",
 188                     authctxt->pw->pw_name);
 189         }
 190 #endif
 191 #endif
 192         /* setup the channel layer */
 193         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 194                 channel_permit_all_opens();
 195
 196         if (compat20)
 197                 do_authenticated2(authctxt);
 198         else
 199                 do_authenticated1(authctxt);
 200
 201         /* remote user's local Xauthority file and agent socket */
 202         if (xauthfile)
 203                 xauthfile_cleanup_proc(NULL);
 204         if (auth_get_socket_name())
 205                 auth_sock_cleanup_proc(NULL);
 206 }
 207
 208 /*
 209  * Remove local Xauthority file.
 210  */
 211 void
 212 xauthfile_cleanup_proc(void *ignore)
 213 {
 214         debug("xauthfile_cleanup_proc called");
 215
 216         if (xauthfile != NULL) {
 217                 char *p;
 218                 unlink(xauthfile);
 219                 p = strrchr(xauthfile, '/');
 220                 if (p != NULL) {
 221                         *p = '\0';
 222                         rmdir(xauthfile);
 223                 }
 224                 xfree(xauthfile);
 225                 xauthfile = NULL;
 226         }
 227 }
 228
 229 /*
 230  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 231  * dropped connection).
 232  */
 233 void
 234 pty_cleanup_proc(void *session)
 235 {
 236         Session *s=session;
 237         if (s == NULL)
 238                 fatal("pty_cleanup_proc: no session");
 239         debug("pty_cleanup_proc: %s", s->tty);
 240
 241         if (s->pid != 0) {
 242                 /* Record that the user has logged out. */
 243                 record_logout(s->pid, s->tty);
 244         }
 245
 246         /* Release the pseudo-tty. */
 247         pty_release(s->tty);
 248 }
 249
 250 /*
 251  * Prepares for an interactive session.  This is called after the user has
 252  * been successfully authenticated.  During this message exchange, pseudo
 253  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 254  * are requested, etc.
 255  */
 256 void
 257 do_authenticated1(Authctxt *authctxt)
 258 {
 259         Session *s;
 260         char *command;
 261         int success, type, fd, n_bytes, plen, screen_flag, have_pty = 0;
 262         int compression_level = 0, enable_compression_after_reply = 0;
 263         u_int proto_len, data_len, dlen;
 264         struct stat st;
 265
 266         s = session_new();
 267         s->pw = authctxt->pw;
 268
 269         /*
 270          * We stay in this loop until the client requests to execute a shell
 271          * or a command.
 272          */
 273         for (;;) {
 274                 success = 0;
 275
 276                 /* Get a packet from the client. */
 277                 type = packet_read(&plen);
 278
 279                 /* Process the packet. */
 280                 switch (type) {
 281                 case SSH_CMSG_REQUEST_COMPRESSION:
 282                         packet_integrity_check(plen, 4, type);
 283                         compression_level = packet_get_int();
 284                         if (compression_level < 1 || compression_level > 9) {
 285                                 packet_send_debug("Received illegal compression level %d.",
 286                                      compression_level);
 287                                 break;
 288                         }
 289                         /* Enable compression after we have responded with SUCCESS. */
 290                         enable_compression_after_reply = 1;
 291                         success = 1;
 292                         break;
 293
 294                 case SSH_CMSG_REQUEST_PTY:
 295                         if (no_pty_flag) {
 296                                 debug("Allocating a pty not permitted for this authentication.");
 297                                 break;
 298                         }
 299                         if (have_pty)
 300                                 packet_disconnect("Protocol error: you already have a pty.");
 301
 302                         debug("Allocating pty.");
 303
 304                         /* Allocate a pty and open it. */
 305                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 306                             sizeof(s->tty))) {
 307                                 error("Failed to allocate pty.");
 308                                 break;
 309                         }
 310                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 311                         pty_setowner(s->pw, s->tty);
 312
 313                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 314                         s->term = packet_get_string(&dlen);
 315                         packet_integrity_check(dlen, strlen(s->term), type);
 316                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 317                         /* Remaining bytes */
 318                         n_bytes = plen - (4 + dlen + 4 * 4);
 319
 320                         if (strcmp(s->term, "") == 0) {
 321                                 xfree(s->term);
 322                                 s->term = NULL;
 323                         }
 324                         /* Get window size from the packet. */
 325                         s->row = packet_get_int();
 326                         s->col = packet_get_int();
 327                         s->xpixel = packet_get_int();
 328                         s->ypixel = packet_get_int();
 329                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 330
 331                         /* Get tty modes from the packet. */
 332                         tty_parse_modes(s->ttyfd, &n_bytes);
 333                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 334
 335                         session_proctitle(s);
 336
 337                         /* Indicate that we now have a pty. */
 338                         success = 1;
 339                         have_pty = 1;
 340                         break;
 341
 342                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 343                         if (!options.x11_forwarding) {
 344                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 345                                 break;
 346                         }
 347                         if (!options.xauth_location ||
 348                             (stat(options.xauth_location, &st) == -1)) {
 349                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 350                                 break;
 351                         }
 352                         if (no_x11_forwarding_flag) {
 353                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 354                                 break;
 355                         }
 356                         debug("Received request for X11 forwarding with auth spoofing.");
 357                         if (s->display != NULL)
 358                                 packet_disconnect("Protocol error: X11 display already set.");
 359
 360                         s->auth_proto = packet_get_string(&proto_len);
 361                         s->auth_data = packet_get_string(&data_len);
 362
 363                         screen_flag = packet_get_protocol_flags() &
 364                             SSH_PROTOFLAG_SCREEN_NUMBER;
 365                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 366
 367                         if (packet_remaining() == 4) {
 368                                 if (!screen_flag)
 369                                         debug2("Buggy client: "
 370                                             "X11 screen flag missing");
 371                                 packet_integrity_check(plen,
 372                                     4 + proto_len + 4 + data_len + 4, type);
 373                                 s->screen = packet_get_int();
 374                         } else {
 375                                 packet_integrity_check(plen,
 376                                     4 + proto_len + 4 + data_len, type);
 377                                 s->screen = 0;
 378                         }
 379                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 380
 381                         if (s->display == NULL)
 382                                 break;
 383
 384                         /* Setup to always have a local .Xauthority. */
 385                         xauthfile = xmalloc(MAXPATHLEN);
 386                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 387                         temporarily_use_uid(s->pw);
 388                         if (mkdtemp(xauthfile) == NULL) {
 389                                 restore_uid();
 390                                 error("private X11 dir: mkdtemp %s failed: %s",
 391                                     xauthfile, strerror(errno));
 392                                 xfree(xauthfile);
 393                                 xauthfile = NULL;
 394                                 /* XXXX remove listening channels */
 395                                 break;
 396                         }
 397                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 398                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 399                         if (fd >= 0)
 400                                 close(fd);
 401                         restore_uid();
 402                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 403                         success = 1;
 404                         break;
 405
 406                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 407                         if (no_agent_forwarding_flag || compat13) {
 408                                 debug("Authentication agent forwarding not permitted for this authentication.");
 409                                 break;
 410                         }
 411                         debug("Received authentication agent forwarding request.");
 412                         success = auth_input_request_forwarding(s->pw);
 413                         break;
 414
 415                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 416                         if (no_port_forwarding_flag) {
 417                                 debug("Port forwarding not permitted for this authentication.");
 418                                 break;
 419                         }
 420                         if (!options.allow_tcp_forwarding) {
 421                                 debug("Port forwarding not permitted.");
 422                                 break;
 423                         }
 424                         debug("Received TCP/IP port forwarding request.");
 425                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 426                         success = 1;
 427                         break;
 428
 429                 case SSH_CMSG_MAX_PACKET_SIZE:
 430                         if (packet_set_maxsize(packet_get_int()) > 0)
 431                                 success = 1;
 432                         break;
 433
 434                 case SSH_CMSG_EXEC_SHELL:
 435                 case SSH_CMSG_EXEC_CMD:
 436                         if (type == SSH_CMSG_EXEC_CMD) {
 437                                 command = packet_get_string(&dlen);
 438                                 debug("Exec command '%.500s'", command);
 439                                 packet_integrity_check(plen, 4 + dlen, type);
 440                         } else {
 441                                 command = NULL;
 442                                 packet_integrity_check(plen, 0, type);
 443                         }
 444                         if (forced_command != NULL) {
 445                                 original_command = command;
 446                                 command = forced_command;
 447                                 debug("Forced command '%.500s'", forced_command);
 448                         }
 449                         if (have_pty)
 450                                 do_exec_pty(s, command);
 451                         else
 452                                 do_exec_no_pty(s, command);
 453
 454                         if (command != NULL)
 455                                 xfree(command);
 456                         return;
 457
 458                 default:
 459                         /*
 460                          * Any unknown messages in this phase are ignored,
 461                          * and a failure message is returned.
 462                          */
 463                         log("Unknown packet type received after authentication: %d", type);
 464                 }
 465                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 466                 packet_send();
 467                 packet_write_wait();
 468
 469                 /* Enable compression now that we have replied if appropriate. */
 470                 if (enable_compression_after_reply) {
 471                         enable_compression_after_reply = 0;
 472                         packet_start_compression(compression_level);
 473                 }
 474         }
 475 }
 476
 477 /*
 478  * This is called to fork and execute a command when we have no tty.  This
 479  * will call do_child from the child, and server_loop from the parent after
 480  * setting up file descriptors and such.
 481  */
 482 void
 483 do_exec_no_pty(Session *s, const char *command)
 484 {
 485         int pid;
 486
 487 #ifdef USE_PIPES
 488         int pin[2], pout[2], perr[2];
 489         /* Allocate pipes for communicating with the program. */
 490         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 491                 packet_disconnect("Could not create pipes: %.100s",
 492                                   strerror(errno));
 493 #else /* USE_PIPES */
 494         int inout[2], err[2];
 495         /* Uses socket pairs to communicate with the program. */
 496         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 497             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 498                 packet_disconnect("Could not create socket pairs: %.100s",
 499                                   strerror(errno));
 500 #endif /* USE_PIPES */
 501         if (s == NULL)
 502                 fatal("do_exec_no_pty: no session");
 503
 504         session_proctitle(s);
 505
 506 #if defined(USE_PAM)
 507         do_pam_setcred(1);
 508 #endif /* USE_PAM */
 509
 510         /* Fork the child. */
 511         if ((pid = fork()) == 0) {
 512                 /* Child.  Reinitialize the log since the pid has changed. */
 513                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 514
 515                 /*
 516                  * Create a new session and process group since the 4.4BSD
 517                  * setlogin() affects the entire process group.
 518                  */
 519                 if (setsid() < 0)
 520                         error("setsid failed: %.100s", strerror(errno));
 521
 522 #ifdef USE_PIPES
 523                 /*
 524                  * Redirect stdin.  We close the parent side of the socket
 525                  * pair, and make the child side the standard input.
 526                  */
 527                 close(pin[1]);
 528                 if (dup2(pin[0], 0) < 0)
 529                         perror("dup2 stdin");
 530                 close(pin[0]);
 531
 532                 /* Redirect stdout. */
 533                 close(pout[0]);
 534                 if (dup2(pout[1], 1) < 0)
 535                         perror("dup2 stdout");
 536                 close(pout[1]);
 537
 538                 /* Redirect stderr. */
 539                 close(perr[0]);
 540                 if (dup2(perr[1], 2) < 0)
 541                         perror("dup2 stderr");
 542                 close(perr[1]);
 543 #else /* USE_PIPES */
 544                 /*
 545                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 546                  * use the same socket, as some programs (particularly rdist)
 547                  * seem to depend on it.
 548                  */
 549                 close(inout[1]);
 550                 close(err[1]);
 551                 if (dup2(inout[0], 0) < 0)      /* stdin */
 552                         perror("dup2 stdin");
 553                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 554                         perror("dup2 stdout");
 555                 if (dup2(err[0], 2) < 0)        /* stderr */
 556                         perror("dup2 stderr");
 557 #endif /* USE_PIPES */
 558
 559                 /* Do processing for the child (exec command etc). */
 560                 do_child(s, command);
 561                 /* NOTREACHED */
 562         }
 563 #ifdef HAVE_CYGWIN
 564         if (is_winnt)
 565                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 566 #endif
 567         if (pid < 0)
 568                 packet_disconnect("fork failed: %.100s", strerror(errno));
 569         s->pid = pid;
 570         /* Set interactive/non-interactive mode. */
 571         packet_set_interactive(s->display != NULL);
 572 #ifdef USE_PIPES
 573         /* We are the parent.  Close the child sides of the pipes. */
 574         close(pin[0]);
 575         close(pout[1]);
 576         close(perr[1]);
 577
 578         if (compat20) {
 579                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 580         } else {
 581                 /* Enter the interactive session. */
 582                 server_loop(pid, pin[1], pout[0], perr[0]);
 583                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 584         }
 585 #else /* USE_PIPES */
 586         /* We are the parent.  Close the child sides of the socket pairs. */
 587         close(inout[0]);
 588         close(err[0]);
 589
 590         /*
 591          * Enter the interactive session.  Note: server_loop must be able to
 592          * handle the case that fdin and fdout are the same.
 593          */
 594         if (compat20) {
 595                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 596         } else {
 597                 server_loop(pid, inout[1], inout[1], err[1]);
 598                 /* server_loop has closed inout[1] and err[1]. */
 599         }
 600 #endif /* USE_PIPES */
 601 }
 602
 603 /*
 604  * This is called to fork and execute a command when we have a tty.  This
 605  * will call do_child from the child, and server_loop from the parent after
 606  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 607  * lastlog, and other such operations.
 608  */
 609 void
 610 do_exec_pty(Session *s, const char *command)
 611 {
 612         int fdout, ptyfd, ttyfd, ptymaster;
 613         pid_t pid;
 614
 615         if (s == NULL)
 616                 fatal("do_exec_pty: no session");
 617         ptyfd = s->ptyfd;
 618         ttyfd = s->ttyfd;
 619
 620 #if defined(USE_PAM)
 621         do_pam_session(s->pw->pw_name, s->tty);
 622         do_pam_setcred(1);
 623 #endif
 624
 625         /* Fork the child. */
 626         if ((pid = fork()) == 0) {
 627                 /* Child.  Reinitialize the log because the pid has changed. */
 628                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 629
 630                 /* Close the master side of the pseudo tty. */
 631                 close(ptyfd);
 632
 633                 /* Make the pseudo tty our controlling tty. */
 634                 pty_make_controlling_tty(&ttyfd, s->tty);
 635
 636                 /* Redirect stdin from the pseudo tty. */
 637                 if (dup2(ttyfd, fileno(stdin)) < 0)
 638                         error("dup2 stdin failed: %.100s", strerror(errno));
 639
 640                 /* Redirect stdout to the pseudo tty. */
 641                 if (dup2(ttyfd, fileno(stdout)) < 0)
 642                         error("dup2 stdin failed: %.100s", strerror(errno));
 643
 644                 /* Redirect stderr to the pseudo tty. */
 645                 if (dup2(ttyfd, fileno(stderr)) < 0)
 646                         error("dup2 stdin failed: %.100s", strerror(errno));
 647
 648                 /* Close the extra descriptor for the pseudo tty. */
 649                 close(ttyfd);
 650
 651                 /* record login, etc. similar to login(1) */
 652 #ifndef HAVE_OSF_SIA
 653                 if (!(options.use_login && command == NULL))
 654                         do_login(s, command);
 655 # ifdef LOGIN_NEEDS_UTMPX
 656                 else
 657                         do_pre_login(s);
 658 # endif
 659 #endif
 660
 661                 /* Do common processing for the child, such as execing the command. */
 662                 do_child(s, command);
 663                 /* NOTREACHED */
 664         }
 665 #ifdef HAVE_CYGWIN
 666         if (is_winnt)
 667                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 668 #endif
 669         if (pid < 0)
 670                 packet_disconnect("fork failed: %.100s", strerror(errno));
 671         s->pid = pid;
 672
 673         /* Parent.  Close the slave side of the pseudo tty. */
 674         close(ttyfd);
 675
 676         /*
 677          * Create another descriptor of the pty master side for use as the
 678          * standard input.  We could use the original descriptor, but this
 679          * simplifies code in server_loop.  The descriptor is bidirectional.
 680          */
 681         fdout = dup(ptyfd);
 682         if (fdout < 0)
 683                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 684
 685         /* we keep a reference to the pty master */
 686         ptymaster = dup(ptyfd);
 687         if (ptymaster < 0)
 688                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 689         s->ptymaster = ptymaster;
 690
 691         /* Enter interactive session. */
 692         packet_set_interactive(1);
 693         if (compat20) {
 694                 session_set_fds(s, ptyfd, fdout, -1);
 695         } else {
 696                 server_loop(pid, ptyfd, fdout, -1);
 697                 /* server_loop _has_ closed ptyfd and fdout. */
 698                 session_pty_cleanup(s);
 699         }
 700 }
 701
 702 #ifdef LOGIN_NEEDS_UTMPX
 703 void
 704 do_pre_login(Session *s)
 705 {
 706         socklen_t fromlen;
 707         struct sockaddr_storage from;
 708         pid_t pid = getpid();
 709
 710         /*
 711          * Get IP address of client. If the connection is not a socket, let
 712          * the address be 0.0.0.0.
 713          */
 714         memset(&from, 0, sizeof(from));
 715         if (packet_connection_is_on_socket()) {
 716                 fromlen = sizeof(from);
 717                 if (getpeername(packet_get_connection_in(),
 718                      (struct sockaddr *) & from, &fromlen) < 0) {
 719                         debug("getpeername: %.100s", strerror(errno));
 720                         fatal_cleanup();
 721                 }
 722         }
 723
 724         record_utmp_only(pid, s->tty, s->pw->pw_name,
 725             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 726             (struct sockaddr *)&from);
 727 }
 728 #endif
 729
 730 /* administrative, login(1)-like work */
 731 void
 732 do_login(Session *s, const char *command)
 733 {
 734         char *time_string;
 735         char hostname[MAXHOSTNAMELEN];
 736         socklen_t fromlen;
 737         struct sockaddr_storage from;
 738         time_t last_login_time;
 739         struct passwd * pw = s->pw;
 740         pid_t pid = getpid();
 741
 742         /*
 743          * Get IP address of client. If the connection is not a socket, let
 744          * the address be 0.0.0.0.
 745          */
 746         memset(&from, 0, sizeof(from));
 747         if (packet_connection_is_on_socket()) {
 748                 fromlen = sizeof(from);
 749                 if (getpeername(packet_get_connection_in(),
 750                      (struct sockaddr *) & from, &fromlen) < 0) {
 751                         debug("getpeername: %.100s", strerror(errno));
 752                         fatal_cleanup();
 753                 }
 754         }
 755
 756         /* Get the time and hostname when the user last logged in. */
 757         if (options.print_lastlog) {
 758                 hostname[0] = '\0';
 759                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 760                     hostname, sizeof(hostname));
 761         }
 762
 763         /* Record that there was a login on that tty from the remote host. */
 764         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 765             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 766             (struct sockaddr *)&from);
 767
 768 #ifdef USE_PAM
 769         /*
 770          * If password change is needed, do it now.
 771          * This needs to occur before the ~/.hushlogin check.
 772          */
 773         if (is_pam_password_change_required()) {
 774                 print_pam_messages();
 775                 do_pam_chauthtok();
 776         }
 777 #endif
 778
 779         if (check_quietlogin(s, command))
 780                 return;
 781
 782 #ifdef USE_PAM
 783         if (!is_pam_password_change_required())
 784                 print_pam_messages();
 785 #endif /* USE_PAM */
 786 #ifdef WITH_AIXAUTHENTICATE
 787         if (aixloginmsg && *aixloginmsg)
 788                 printf("%s\n", aixloginmsg);
 789 #endif /* WITH_AIXAUTHENTICATE */
 790
 791         if (options.print_lastlog && last_login_time != 0) {
 792                 time_string = ctime(&last_login_time);
 793                 if (strchr(time_string, '\n'))
 794                         *strchr(time_string, '\n') = 0;
 795                 if (strcmp(hostname, "") == 0)
 796                         printf("Last login: %s\r\n", time_string);
 797                 else
 798                         printf("Last login: %s from %s\r\n", time_string, hostname);
 799         }
 800
 801         do_motd();
 802 }
 803
 804 /*
 805  * Display the message of the day.
 806  */
 807 void
 808 do_motd(void)
 809 {
 810         FILE *f;
 811         char buf[256];
 812
 813         if (options.print_motd) {
 814 #ifdef HAVE_LOGIN_CAP
 815                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 816                     "/etc/motd"), "r");
 817 #else
 818                 f = fopen("/etc/motd", "r");
 819 #endif
 820                 if (f) {
 821                         while (fgets(buf, sizeof(buf), f))
 822                                 fputs(buf, stdout);
 823                         fclose(f);
 824                 }
 825         }
 826 }
 827
 828
 829 /*
 830  * Check for quiet login, either .hushlogin or command given.
 831  */
 832 int
 833 check_quietlogin(Session *s, const char *command)
 834 {
 835         char buf[256];
 836         struct passwd * pw = s->pw;
 837         struct stat st;
 838
 839         /* Return 1 if .hushlogin exists or a command given. */
 840         if (command != NULL)
 841                 return 1;
 842         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 843 #ifdef HAVE_LOGIN_CAP
 844         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 845                 return 1;
 846 #else
 847         if (stat(buf, &st) >= 0)
 848                 return 1;
 849 #endif
 850         return 0;
 851 }
 852
 853 /*
 854  * Sets the value of the given variable in the environment.  If the variable
 855  * already exists, its value is overriden.
 856  */
 857 void
 858 child_set_env(char ***envp, u_int *envsizep, const char *name,
 859               const char *value)
 860 {
 861         u_int i, namelen;
 862         char **env;
 863
 864         /*
 865          * Find the slot where the value should be stored.  If the variable
 866          * already exists, we reuse the slot; otherwise we append a new slot
 867          * at the end of the array, expanding if necessary.
 868          */
 869         env = *envp;
 870         namelen = strlen(name);
 871         for (i = 0; env[i]; i++)
 872                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 873                         break;
 874         if (env[i]) {
 875                 /* Reuse the slot. */
 876                 xfree(env[i]);
 877         } else {
 878                 /* New variable.  Expand if necessary. */
 879                 if (i >= (*envsizep) - 1) {
 880                         (*envsizep) += 50;
 881                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 882                 }
 883                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 884                 env[i + 1] = NULL;
 885         }
 886
 887         /* Allocate space and format the variable in the appropriate slot. */
 888         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 889         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 890 }
 891
 892 /*
 893  * Reads environment variables from the given file and adds/overrides them
 894  * into the environment.  If the file does not exist, this does nothing.
 895  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 896  * and assignments of the form name=value.  No other forms are allowed.
 897  */
 898 void
 899 read_environment_file(char ***env, u_int *envsize,
 900                       const char *filename)
 901 {
 902         FILE *f;
 903         char buf[4096];
 904         char *cp, *value;
 905
 906         f = fopen(filename, "r");
 907         if (!f)
 908                 return;
 909
 910         while (fgets(buf, sizeof(buf), f)) {
 911                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 912                         ;
 913                 if (!*cp || *cp == '#' || *cp == '\n')
 914                         continue;
 915                 if (strchr(cp, '\n'))
 916                         *strchr(cp, '\n') = '\0';
 917                 value = strchr(cp, '=');
 918                 if (value == NULL) {
 919                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 920                         continue;
 921                 }
 922                 /*
 923                  * Replace the equals sign by nul, and advance value to
 924                  * the value string.
 925                  */
 926                 *value = '\0';
 927                 value++;
 928                 child_set_env(env, envsize, cp, value);
 929         }
 930         fclose(f);
 931 }
 932
 933 #ifdef USE_PAM
 934 /*
 935  * Sets any environment variables which have been specified by PAM
 936  */
 937 void do_pam_environment(char ***env, int *envsize)
 938 {
 939         char *equals, var_name[512], var_val[512];
 940         char **pam_env;
 941         int i;
 942
 943         if ((pam_env = fetch_pam_environment()) == NULL)
 944                 return;
 945
 946         for(i = 0; pam_env[i] != NULL; i++) {
 947                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 948                         continue;
 949
 950                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 951                         memset(var_name, '\0', sizeof(var_name));
 952                         memset(var_val, '\0', sizeof(var_val));
 953
 954                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 955                         strcpy(var_val, equals + 1);
 956
 957                         debug3("PAM environment: %s=%s", var_name, var_val);
 958
 959                         child_set_env(env, envsize, var_name, var_val);
 960                 }
 961         }
 962 }
 963 #endif /* USE_PAM */
 964
 965 #ifdef HAVE_CYGWIN
 966 void copy_environment(char ***env, int *envsize)
 967 {
 968         char *equals, var_name[512], var_val[512];
 969         int i;
 970
 971         for(i = 0; environ[i] != NULL; i++) {
 972                 if ((equals = strstr(environ[i], "=")) == NULL)
 973                         continue;
 974
 975                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 976                         memset(var_name, '\0', sizeof(var_name));
 977                         memset(var_val, '\0', sizeof(var_val));
 978
 979                         strncpy(var_name, environ[i], equals - environ[i]);
 980                         strcpy(var_val, equals + 1);
 981
 982                         debug3("Copy environment: %s=%s", var_name, var_val);
 983
 984                         child_set_env(env, envsize, var_name, var_val);
 985                 }
 986         }
 987 }
 988 #endif
 989
 990 #if defined(HAVE_GETUSERATTR)
 991 /*
 992  * AIX-specific login initialisation
 993  */
 994 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 995 {
 996         struct rlimit rlim;
 997         int slim, hlim;
 998
 999         getrlimit(resource, &rlim);
1000
1001         slim = 0;
1002         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
1003                 if (slim < 0) {
1004                         rlim.rlim_cur = RLIM_INFINITY;
1005                 } else if (slim != 0) {
1006                         /* See the wackiness below */
1007                         if (rlim.rlim_cur == slim * mult)
1008                                 slim = 0;
1009                         else
1010                                 rlim.rlim_cur = slim * mult;
1011                 }
1012         }
1013
1014         hlim = 0;
1015         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
1016                 if (hlim < 0) {
1017                         rlim.rlim_max = RLIM_INFINITY;
1018                 } else if (hlim != 0) {
1019                         rlim.rlim_max = hlim * mult;
1020                 }
1021         }
1022
1023         /*
1024          * XXX For cpu and fsize the soft limit is set to the hard limit
1025          * if the hard limit is left at its default value and the soft limit
1026          * is changed from its default value, either by requesting it
1027          * (slim == 0) or by setting it to the current default.  At least
1028          * that's how rlogind does it.  If you're confused you're not alone.
1029          * Bug or feature? AIX 4.3.1.2
1030          */
1031         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
1032             && hlim == 0 && slim != 0)
1033                 rlim.rlim_max = rlim.rlim_cur;
1034         /* A specified hard limit limits the soft limit */
1035         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
1036                 rlim.rlim_cur = rlim.rlim_max;
1037         /* A soft limit can increase a hard limit */
1038         else if (rlim.rlim_cur > rlim.rlim_max)
1039                 rlim.rlim_max = rlim.rlim_cur;
1040
1041         if (setrlimit(resource, &rlim) != 0)
1042                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
1043 }
1044
1045 void set_limits_from_userattr(char *user)
1046 {
1047         int mask;
1048         char buf[16];
1049
1050         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
1051         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
1052         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
1053         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
1054         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
1055         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
1056 #if defined(S_UNOFILE)
1057         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1058 #endif
1059
1060         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1061                 /* Convert decimal to octal */
1062                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1063                 if (sscanf(buf, "%o", &mask) == 1)
1064                         umask(mask);
1065         }
1066 }
1067 #endif /* defined(HAVE_GETUSERATTR) */
1068
1069 /*
1070  * Performs common processing for the child, such as setting up the
1071  * environment, closing extra file descriptors, setting the user and group
1072  * ids, and executing the command or shell.
1073  */
1074 void
1075 do_child(Session *s, const char *command)
1076 {
1077         const char *shell, *hostname = NULL, *cp = NULL;
1078         struct passwd * pw = s->pw;
1079         char buf[256];
1080         char cmd[1024];
1081         FILE *f = NULL;
1082         u_int envsize, i;
1083         char **env;
1084         extern char **environ;
1085         struct stat st;
1086         char *argv[10];
1087         int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1088 #ifdef WITH_IRIX_PROJECT
1089         prid_t projid;
1090 #endif /* WITH_IRIX_PROJECT */
1091 #ifdef WITH_IRIX_JOBS
1092         jid_t jid = 0;
1093 #else
1094 #ifdef WITH_IRIX_ARRAY
1095         int jid = 0;
1096 #endif /* WITH_IRIX_ARRAY */
1097 #endif /* WITH_IRIX_JOBS */
1098
1099         /* remove hostkey from the child's memory */
1100         destroy_sensitive_data();
1101
1102         /* login(1) is only called if we execute the login shell */
1103         if (options.use_login && command != NULL)
1104                 options.use_login = 0;
1105
1106 #if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
1107         if (!options.use_login) {
1108 # ifdef HAVE_LOGIN_CAP
1109                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1110                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1111                             _PATH_NOLOGIN), "r");
1112 # else /* HAVE_LOGIN_CAP */
1113                 if (pw->pw_uid)
1114                         f = fopen(_PATH_NOLOGIN, "r");
1115 # endif /* HAVE_LOGIN_CAP */
1116                 if (f) {
1117                         /* /etc/nologin exists.  Print its contents and exit. */
1118                         while (fgets(buf, sizeof(buf), f))
1119                                 fputs(buf, stderr);
1120                         fclose(f);
1121                         exit(254);
1122                 }
1123         }
1124 #endif /* USE_PAM || HAVE_OSF_SIA */
1125
1126         /* Set login name, uid, gid, and groups. */
1127         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1128            switch, so we let login(1) to this for us. */
1129         if (!options.use_login) {
1130 #ifdef HAVE_OSF_SIA
1131                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1132                 if (!check_quietlogin(s, command))
1133                         do_motd();
1134 #else /* HAVE_OSF_SIA */
1135 #ifdef HAVE_CYGWIN
1136                 if (is_winnt) {
1137 #else
1138                 if (getuid() == 0 || geteuid() == 0) {
1139 #endif
1140 # ifdef HAVE_GETUSERATTR
1141                         set_limits_from_userattr(pw->pw_name);
1142 # endif /* HAVE_GETUSERATTR */
1143 # ifdef HAVE_LOGIN_CAP
1144                         if (setusercontext(lc, pw, pw->pw_uid,
1145                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1146                                 perror("unable to set user context");
1147                                 exit(1);
1148                         }
1149 # else /* HAVE_LOGIN_CAP */
1150 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1151                         /* Sets login uid for accounting */
1152                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1153                                 error("setluid: %s", strerror(errno));
1154 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1155
1156                         if (setlogin(pw->pw_name) < 0)
1157                                 error("setlogin failed: %s", strerror(errno));
1158                         if (setgid(pw->pw_gid) < 0) {
1159                                 perror("setgid");
1160                                 exit(1);
1161                         }
1162                         /* Initialize the group list. */
1163                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1164                                 perror("initgroups");
1165                                 exit(1);
1166                         }
1167                         endgrent();
1168 #  ifdef USE_PAM
1169                         /*
1170                          * PAM credentials may take the form of
1171                          * supplementary groups. These will have been
1172                          * wiped by the above initgroups() call.
1173                          * Reestablish them here.
1174                          */
1175                         do_pam_setcred(0);
1176 #  endif /* USE_PAM */
1177 #  ifdef WITH_IRIX_JOBS
1178                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1179                         if (jid == -1) {
1180                                 fatal("Failed to create job container: %.100s",
1181                                       strerror(errno));
1182                         }
1183 #  endif /* WITH_IRIX_JOBS */
1184 #  ifdef WITH_IRIX_ARRAY
1185                         /* initialize array session */
1186                         if (jid == 0) {
1187                                 if (newarraysess() != 0)
1188                                         fatal("Failed to set up new array session: %.100s",
1189                                               strerror(errno));
1190                         }
1191 #  endif /* WITH_IRIX_ARRAY */
1192 #  ifdef WITH_IRIX_PROJECT
1193                         /* initialize irix project info */
1194                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1195                           debug("Failed to get project id, using projid 0");
1196                           projid = 0;
1197                         }
1198                         if (setprid(projid))
1199                           fatal("Failed to initialize project %d for %s: %.100s",
1200                                 (int)projid, pw->pw_name, strerror(errno));
1201 #  endif /* WITH_IRIX_PROJECT */
1202 #ifdef WITH_IRIX_AUDIT
1203                         if (sysconf(_SC_AUDIT)) {
1204                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1205                                 if (satsetid(pw->pw_uid))
1206                                         debug("error setting satid: %.100s", strerror(errno));
1207                         }
1208 #endif /* WITH_IRIX_AUDIT */
1209
1210 #ifdef _AIX
1211                         /*
1212                          * AIX has a "usrinfo" area where logname and
1213                          * other stuff is stored - a few applications
1214                          * actually use this and die if it's not set
1215                          */
1216                         if (s->ttyfd == -1)
1217                                 s->tty[0] = '\0';
1218                         cp = xmalloc(22 + strlen(s->tty) +
1219                             2 * strlen(pw->pw_name));
1220                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1221                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1222                         if (usrinfo(SETUINFO, cp, i) == -1)
1223                                 fatal("Couldn't set usrinfo: %s",
1224                                     strerror(errno));
1225                         debug3("AIX/UsrInfo: set len %d", i);
1226                         xfree(cp);
1227 #endif
1228
1229                         /* Permanently switch to the desired uid. */
1230                         permanently_set_uid(pw);
1231 # endif /* HAVE_LOGIN_CAP */
1232                 }
1233 #endif /* HAVE_OSF_SIA */
1234
1235 #ifdef HAVE_CYGWIN
1236                 if (is_winnt)
1237 #endif
1238                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1239                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1240         }
1241         /*
1242          * Get the shell from the password data.  An empty shell field is
1243          * legal, and means /bin/sh.
1244          */
1245         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1246 #ifdef HAVE_LOGIN_CAP
1247         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1248 #endif
1249
1250 #ifdef AFS
1251         /* Try to get AFS tokens for the local cell. */
1252         if (k_hasafs()) {
1253                 char cell[64];
1254
1255                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1256                         krb_afslog(cell, 0);
1257
1258                 krb_afslog(0, 0);
1259         }
1260 #endif /* AFS */
1261
1262         /* Initialize the environment. */
1263         envsize = 100;
1264         env = xmalloc(envsize * sizeof(char *));
1265         env[0] = NULL;
1266
1267 #ifdef HAVE_CYGWIN
1268         /*
1269          * The Windows environment contains some setting which are
1270          * important for a running system. They must not be dropped.
1271          */
1272         copy_environment(&env, &envsize);
1273 #endif
1274
1275         if (!options.use_login) {
1276                 /* Set basic environment. */
1277                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1278                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1279                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1280 #ifdef HAVE_LOGIN_CAP
1281                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1282                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1283 #else /* HAVE_LOGIN_CAP */
1284 # ifndef HAVE_CYGWIN
1285                 /*
1286                  * There's no standard path on Windows. The path contains
1287                  * important components pointing to the system directories,
1288                  * needed for loading shared libraries. So the path better
1289                  * remains intact here.
1290                  */
1291                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1292 # endif /* HAVE_CYGWIN */
1293 #endif /* HAVE_LOGIN_CAP */
1294
1295                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1296                          _PATH_MAILDIR, pw->pw_name);
1297                 child_set_env(&env, &envsize, "MAIL", buf);
1298
1299                 /* Normal systems set SHELL by default. */
1300                 child_set_env(&env, &envsize, "SHELL", shell);
1301         }
1302         if (getenv("TZ"))
1303                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1304
1305         /* Set custom environment options from RSA authentication. */
1306         while (custom_environment) {
1307                 struct envstring *ce = custom_environment;
1308                 char *s = ce->s;
1309                 int i;
1310                 for (i = 0; s[i] != '=' && s[i]; i++);
1311                 if (s[i] == '=') {
1312                         s[i] = 0;
1313                         child_set_env(&env, &envsize, s, s + i + 1);
1314                 }
1315                 custom_environment = ce->next;
1316                 xfree(ce->s);
1317                 xfree(ce);
1318         }
1319
1320         snprintf(buf, sizeof buf, "%.50s %d %d",
1321                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1322         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1323
1324         if (s->ttyfd != -1)
1325                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1326         if (s->term)
1327                 child_set_env(&env, &envsize, "TERM", s->term);
1328         if (s->display)
1329                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1330         if (original_command)
1331                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1332                     original_command);
1333
1334 #ifdef _AIX
1335         if ((cp = getenv("AUTHSTATE")) != NULL)
1336                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1337         if ((cp = getenv("KRB5CCNAME")) != NULL)
1338                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1339         read_environment_file(&env, &envsize, "/etc/environment");
1340 #endif
1341
1342 #ifdef KRB4
1343         {
1344                 extern char *ticket;
1345
1346                 if (ticket)
1347                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1348         }
1349 #endif /* KRB4 */
1350
1351 #ifdef USE_PAM
1352         /* Pull in any environment variables that may have been set by PAM. */
1353         do_pam_environment(&env, &envsize);
1354 #endif /* USE_PAM */
1355
1356         if (xauthfile)
1357                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1358         if (auth_get_socket_name() != NULL)
1359                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1360                               auth_get_socket_name());
1361
1362         /* read $HOME/.ssh/environment. */
1363         if (!options.use_login) {
1364                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1365                     pw->pw_dir);
1366                 read_environment_file(&env, &envsize, buf);
1367         }
1368         if (debug_flag) {
1369                 /* dump the environment */
1370                 fprintf(stderr, "Environment:\n");
1371                 for (i = 0; env[i]; i++)
1372                         fprintf(stderr, "  %.200s\n", env[i]);
1373         }
1374         /* we have to stash the hostname before we close our socket. */
1375         if (options.use_login)
1376                 hostname = get_remote_name_or_ip(utmp_len,
1377                     options.reverse_mapping_check);
1378         /*
1379          * Close the connection descriptors; note that this is the child, and
1380          * the server will still have the socket open, and it is important
1381          * that we do not shutdown it.  Note that the descriptors cannot be
1382          * closed before building the environment, as we call
1383          * get_remote_ipaddr there.
1384          */
1385         if (packet_get_connection_in() == packet_get_connection_out())
1386                 close(packet_get_connection_in());
1387         else {
1388                 close(packet_get_connection_in());
1389                 close(packet_get_connection_out());
1390         }
1391         /*
1392          * Close all descriptors related to channels.  They will still remain
1393          * open in the parent.
1394          */
1395         /* XXX better use close-on-exec? -markus */
1396         channel_close_all();
1397
1398         /*
1399          * Close any extra file descriptors.  Note that there may still be
1400          * descriptors left by system functions.  They will be closed later.
1401          */
1402         endpwent();
1403
1404         /*
1405          * Close any extra open file descriptors so that we don\'t have them
1406          * hanging around in clients.  Note that we want to do this after
1407          * initgroups, because at least on Solaris 2.3 it leaves file
1408          * descriptors open.
1409          */
1410         for (i = 3; i < 64; i++)
1411                 close(i);
1412
1413         /* Change current directory to the user\'s home directory. */
1414         if (chdir(pw->pw_dir) < 0) {
1415                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1416                         pw->pw_dir, strerror(errno));
1417 #ifdef HAVE_LOGIN_CAP
1418                 if (login_getcapbool(lc, "requirehome", 0))
1419                         exit(1);
1420 #endif
1421         }
1422
1423         /*
1424          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1425          * xauth are run in the proper environment.
1426          */
1427         environ = env;
1428
1429         /*
1430          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1431          * in this order).
1432          */
1433         if (!options.use_login) {
1434                 /* ignore _PATH_SSH_USER_RC for subsystems */
1435                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1436                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1437                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1438                         if (debug_flag)
1439                                 fprintf(stderr, "Running %s\n", cmd);
1440                         f = popen(cmd, "w");
1441                         if (f) {
1442                                 if (do_xauth)
1443                                         fprintf(f, "%s %s\n", s->auth_proto,
1444                                             s->auth_data);
1445                                 pclose(f);
1446                         } else
1447                                 fprintf(stderr, "Could not run %s\n",
1448                                     _PATH_SSH_USER_RC);
1449                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1450                         if (debug_flag)
1451                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1452                                     _PATH_SSH_SYSTEM_RC);
1453                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1454                         if (f) {
1455                                 if (do_xauth)
1456                                         fprintf(f, "%s %s\n", s->auth_proto,
1457                                             s->auth_data);
1458                                 pclose(f);
1459                         } else
1460                                 fprintf(stderr, "Could not run %s\n",
1461                                     _PATH_SSH_SYSTEM_RC);
1462                 } else if (do_xauth && options.xauth_location != NULL) {
1463                         /* Add authority data to .Xauthority if appropriate. */
1464                         char *screen = strchr(s->display, ':');
1465
1466                         if (debug_flag) {
1467                                 fprintf(stderr,
1468                                     "Running %.100s add "
1469                                     "%.100s %.100s %.100s\n",
1470                                     options.xauth_location, s->display,
1471                                     s->auth_proto, s->auth_data);
1472                                 if (screen != NULL)
1473                                         fprintf(stderr,
1474                                             "Adding %.*s/unix%s %s %s\n",
1475                                             (int)(screen - s->display),
1476                                             s->display, screen,
1477                                             s->auth_proto, s->auth_data);
1478                         }
1479                         snprintf(cmd, sizeof cmd, "%s -q -",
1480                             options.xauth_location);
1481                         f = popen(cmd, "w");
1482                         if (f) {
1483                                 fprintf(f, "add %s %s %s\n", s->display,
1484                                     s->auth_proto, s->auth_data);
1485                                 if (screen != NULL)
1486                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1487                                             (int)(screen - s->display),
1488                                             s->display, screen,
1489                                             s->auth_proto,
1490                                             s->auth_data);
1491                                 pclose(f);
1492                         } else {
1493                                 fprintf(stderr, "Could not run %s\n",
1494                                     cmd);
1495                         }
1496                 }
1497                 /* Get the last component of the shell name. */
1498                 cp = strrchr(shell, '/');
1499                 if (cp)
1500                         cp++;
1501                 else
1502                         cp = shell;
1503         }
1504
1505         /* restore SIGPIPE for child */
1506         signal(SIGPIPE,  SIG_DFL);
1507
1508         /*
1509          * If we have no command, execute the shell.  In this case, the shell
1510          * name to be passed in argv[0] is preceded by '-' to indicate that
1511          * this is a login shell.
1512          */
1513         if (!command) {
1514                 if (!options.use_login) {
1515                         char buf[256];
1516
1517                         /*
1518                          * Check for mail if we have a tty and it was enabled
1519                          * in server options.
1520                          */
1521                         if (s->ttyfd != -1 && options.check_mail) {
1522                                 char *mailbox;
1523                                 struct stat mailstat;
1524
1525                                 mailbox = getenv("MAIL");
1526                                 if (mailbox != NULL) {
1527                                         if (stat(mailbox, &mailstat) != 0 ||
1528                                             mailstat.st_size == 0)
1529                                                 printf("No mail.\n");
1530                                         else if (mailstat.st_mtime < mailstat.st_atime)
1531                                                 printf("You have mail.\n");
1532                                         else
1533                                                 printf("You have new mail.\n");
1534                                 }
1535                         }
1536                         /* Start the shell.  Set initial character to '-'. */
1537                         buf[0] = '-';
1538                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1539                         buf[sizeof(buf) - 1] = 0;
1540
1541                         /* Execute the shell. */
1542                         argv[0] = buf;
1543                         argv[1] = NULL;
1544                         execve(shell, argv, env);
1545
1546                         /* Executing the shell failed. */
1547                         perror(shell);
1548                         exit(1);
1549
1550                 } else {
1551                         /* Launch login(1). */
1552
1553                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1554 #ifdef LOGIN_NEEDS_TERM
1555                              s->term? s->term : "unknown",
1556 #endif
1557                              "-p", "-f", "--", pw->pw_name, NULL);
1558
1559                         /* Login couldn't be executed, die. */
1560
1561                         perror("login");
1562                         exit(1);
1563                 }
1564         }
1565         /*
1566          * Execute the command using the user's shell.  This uses the -c
1567          * option to execute the command.
1568          */
1569         argv[0] = (char *) cp;
1570         argv[1] = "-c";
1571         argv[2] = (char *) command;
1572         argv[3] = NULL;
1573         execve(shell, argv, env);
1574         perror(shell);
1575         exit(1);
1576 }
1577
1578 Session *
1579 session_new(void)
1580 {
1581         int i;
1582         static int did_init = 0;
1583         if (!did_init) {
1584                 debug("session_new: init");
1585                 for(i = 0; i < MAX_SESSIONS; i++) {
1586                         sessions[i].used = 0;
1587                         sessions[i].self = i;
1588                 }
1589                 did_init = 1;
1590         }
1591         for(i = 0; i < MAX_SESSIONS; i++) {
1592                 Session *s = &sessions[i];
1593                 if (! s->used) {
1594                         memset(s, 0, sizeof(*s));
1595                         s->chanid = -1;
1596                         s->ptyfd = -1;
1597                         s->ttyfd = -1;
1598                         s->used = 1;
1599                         debug("session_new: session %d", i);
1600                         return s;
1601                 }
1602         }
1603         return NULL;
1604 }
1605
1606 void
1607 session_dump(void)
1608 {
1609         int i;
1610         for(i = 0; i < MAX_SESSIONS; i++) {
1611                 Session *s = &sessions[i];
1612                 debug("dump: used %d session %d %p channel %d pid %d",
1613                     s->used,
1614                     s->self,
1615                     s,
1616                     s->chanid,
1617                     s->pid);
1618         }
1619 }
1620
1621 int
1622 session_open(int chanid)
1623 {
1624         Session *s = session_new();
1625         debug("session_open: channel %d", chanid);
1626         if (s == NULL) {
1627                 error("no more sessions");
1628                 return 0;
1629         }
1630         s->pw = auth_get_user();
1631         if (s->pw == NULL)
1632                 fatal("no user for session %d", s->self);
1633         debug("session_open: session %d: link with channel %d", s->self, chanid);
1634         s->chanid = chanid;
1635         return 1;
1636 }
1637
1638 Session *
1639 session_by_channel(int id)
1640 {
1641         int i;
1642         for(i = 0; i < MAX_SESSIONS; i++) {
1643                 Session *s = &sessions[i];
1644                 if (s->used && s->chanid == id) {
1645                         debug("session_by_channel: session %d channel %d", i, id);
1646                         return s;
1647                 }
1648         }
1649         debug("session_by_channel: unknown channel %d", id);
1650         session_dump();
1651         return NULL;
1652 }
1653
1654 Session *
1655 session_by_pid(pid_t pid)
1656 {
1657         int i;
1658         debug("session_by_pid: pid %d", pid);
1659         for(i = 0; i < MAX_SESSIONS; i++) {
1660                 Session *s = &sessions[i];
1661                 if (s->used && s->pid == pid)
1662                         return s;
1663         }
1664         error("session_by_pid: unknown pid %d", pid);
1665         session_dump();
1666         return NULL;
1667 }
1668
1669 int
1670 session_window_change_req(Session *s)
1671 {
1672         s->col = packet_get_int();
1673         s->row = packet_get_int();
1674         s->xpixel = packet_get_int();
1675         s->ypixel = packet_get_int();
1676         packet_done();
1677         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1678         return 1;
1679 }
1680
1681 int
1682 session_pty_req(Session *s)
1683 {
1684         u_int len;
1685         int n_bytes;
1686
1687         if (no_pty_flag)
1688                 return 0;
1689         if (s->ttyfd != -1)
1690                 return 0;
1691         s->term = packet_get_string(&len);
1692         s->col = packet_get_int();
1693         s->row = packet_get_int();
1694         s->xpixel = packet_get_int();
1695         s->ypixel = packet_get_int();
1696
1697         if (strcmp(s->term, "") == 0) {
1698                 xfree(s->term);
1699                 s->term = NULL;
1700         }
1701         /* Allocate a pty and open it. */
1702         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1703                 xfree(s->term);
1704                 s->term = NULL;
1705                 s->ptyfd = -1;
1706                 s->ttyfd = -1;
1707                 error("session_pty_req: session %d alloc failed", s->self);
1708                 return 0;
1709         }
1710         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1711         /*
1712          * Add a cleanup function to clear the utmp entry and record logout
1713          * time in case we call fatal() (e.g., the connection gets closed).
1714          */
1715         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1716         pty_setowner(s->pw, s->tty);
1717         /* Get window size from the packet. */
1718         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1719
1720         /* Get tty modes from the packet. */
1721         tty_parse_modes(s->ttyfd, &n_bytes);
1722         packet_done();
1723
1724         session_proctitle(s);
1725
1726         return 1;
1727 }
1728
1729 int
1730 session_subsystem_req(Session *s)
1731 {
1732         u_int len;
1733         int success = 0;
1734         char *subsys = packet_get_string(&len);
1735         int i;
1736
1737         packet_done();
1738         log("subsystem request for %s", subsys);
1739
1740         for (i = 0; i < options.num_subsystems; i++) {
1741                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1742                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1743                         s->is_subsystem = 1;
1744                         do_exec_no_pty(s, options.subsystem_command[i]);
1745                         success = 1;
1746                 }
1747         }
1748
1749         if (!success)
1750                 log("subsystem request for %s failed, subsystem not found", subsys);
1751
1752         xfree(subsys);
1753         return success;
1754 }
1755
1756 int
1757 session_x11_req(Session *s)
1758 {
1759         int fd;
1760         struct stat st;
1761         if (no_x11_forwarding_flag) {
1762                 debug("X11 forwarding disabled in user configuration file.");
1763                 return 0;
1764         }
1765         if (!options.x11_forwarding) {
1766                 debug("X11 forwarding disabled in server configuration file.");
1767                 return 0;
1768         }
1769         if (!options.xauth_location ||
1770             (stat(options.xauth_location, &st) == -1)) {
1771                 packet_send_debug("No xauth program; cannot forward with spoofing.");
1772                 return 0;
1773         }
1774         if (xauthfile != NULL) {
1775                 debug("X11 fwd already started.");
1776                 return 0;
1777         }
1778
1779         debug("Received request for X11 forwarding with auth spoofing.");
1780         if (s->display != NULL)
1781                 packet_disconnect("Protocol error: X11 display already set.");
1782
1783         s->single_connection = packet_get_char();
1784         s->auth_proto = packet_get_string(NULL);
1785         s->auth_data = packet_get_string(NULL);
1786         s->screen = packet_get_int();
1787         packet_done();
1788
1789         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1790         if (s->display == NULL) {
1791                 xfree(s->auth_proto);
1792                 xfree(s->auth_data);
1793                 return 0;
1794         }
1795         xauthfile = xmalloc(MAXPATHLEN);
1796         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1797         temporarily_use_uid(s->pw);
1798         if (mkdtemp(xauthfile) == NULL) {
1799                 restore_uid();
1800                 error("private X11 dir: mkdtemp %s failed: %s",
1801                     xauthfile, strerror(errno));
1802                 xfree(xauthfile);
1803                 xauthfile = NULL;
1804                 xfree(s->auth_proto);
1805                 xfree(s->auth_data);
1806                 /* XXXX remove listening channels */
1807                 return 0;
1808         }
1809         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1810         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1811         if (fd >= 0)
1812                 close(fd);
1813         restore_uid();
1814         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1815         return 1;
1816 }
1817
1818 int
1819 session_shell_req(Session *s)
1820 {
1821         /* if forced_command == NULL, the shell is execed */
1822         char *shell = forced_command;
1823         packet_done();
1824         if (s->ttyfd == -1)
1825                 do_exec_no_pty(s, shell);
1826         else
1827                 do_exec_pty(s, shell);
1828         return 1;
1829 }
1830
1831 int
1832 session_exec_req(Session *s)
1833 {
1834         u_int len;
1835         char *command = packet_get_string(&len);
1836         packet_done();
1837         if (forced_command) {
1838                 original_command = command;
1839                 command = forced_command;
1840                 debug("Forced command '%.500s'", forced_command);
1841         }
1842         if (s->ttyfd == -1)
1843                 do_exec_no_pty(s, command);
1844         else
1845                 do_exec_pty(s, command);
1846         if (forced_command == NULL)
1847                 xfree(command);
1848         return 1;
1849 }
1850
1851 int
1852 session_auth_agent_req(Session *s)
1853 {
1854         static int called = 0;
1855         packet_done();
1856         if (no_agent_forwarding_flag) {
1857                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1858                 return 0;
1859         }
1860         if (called) {
1861                 return 0;
1862         } else {
1863                 called = 1;
1864                 return auth_input_request_forwarding(s->pw);
1865         }
1866 }
1867
1868 void
1869 session_input_channel_req(int id, void *arg)
1870 {
1871         u_int len;
1872         int reply;
1873         int success = 0;
1874         char *rtype;
1875         Session *s;
1876         Channel *c;
1877
1878         rtype = packet_get_string(&len);
1879         reply = packet_get_char();
1880
1881         s = session_by_channel(id);
1882         if (s == NULL)
1883                 fatal("session_input_channel_req: channel %d: no session", id);
1884         c = channel_lookup(id);
1885         if (c == NULL)
1886                 fatal("session_input_channel_req: channel %d: bad channel", id);
1887
1888         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1889             s->self, id, rtype, reply);
1890
1891         /*
1892          * a session is in LARVAL state until a shell, a command
1893          * or a subsystem is executed
1894          */
1895         if (c->type == SSH_CHANNEL_LARVAL) {
1896                 if (strcmp(rtype, "shell") == 0) {
1897                         success = session_shell_req(s);
1898                 } else if (strcmp(rtype, "exec") == 0) {
1899                         success = session_exec_req(s);
1900                 } else if (strcmp(rtype, "pty-req") == 0) {
1901                         success =  session_pty_req(s);
1902                 } else if (strcmp(rtype, "x11-req") == 0) {
1903                         success = session_x11_req(s);
1904                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1905                         success = session_auth_agent_req(s);
1906                 } else if (strcmp(rtype, "subsystem") == 0) {
1907                         success = session_subsystem_req(s);
1908                 }
1909         }
1910         if (strcmp(rtype, "window-change") == 0) {
1911                 success = session_window_change_req(s);
1912         }
1913
1914         if (reply) {
1915                 packet_start(success ?
1916                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1917                 packet_put_int(c->remote_id);
1918                 packet_send();
1919         }
1920         xfree(rtype);
1921 }
1922
1923 void
1924 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1925 {
1926         if (!compat20)
1927                 fatal("session_set_fds: called for proto != 2.0");
1928         /*
1929          * now that have a child and a pipe to the child,
1930          * we can activate our channel and register the fd's
1931          */
1932         if (s->chanid == -1)
1933                 fatal("no channel for session %d", s->self);
1934         channel_set_fds(s->chanid,
1935             fdout, fdin, fderr,
1936             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1937             1);
1938 }
1939
1940 void
1941 session_pty_cleanup(Session *s)
1942 {
1943         if (s == NULL || s->ttyfd == -1)
1944                 return;
1945
1946         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1947
1948         /* Cancel the cleanup function. */
1949         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1950
1951         /* Record that the user has logged out. */
1952         record_logout(s->pid, s->tty);
1953
1954         /* Release the pseudo-tty. */
1955         pty_release(s->tty);
1956
1957         /*
1958          * Close the server side of the socket pairs.  We must do this after
1959          * the pty cleanup, so that another process doesn't get this pty
1960          * while we're still cleaning up.
1961          */
1962         if (close(s->ptymaster) < 0)
1963                 error("close(s->ptymaster): %s", strerror(errno));
1964 }
1965
1966 void
1967 session_exit_message(Session *s, int status)
1968 {
1969         Channel *c;
1970         if (s == NULL)
1971                 fatal("session_close: no session");
1972         c = channel_lookup(s->chanid);
1973         if (c == NULL)
1974                 fatal("session_close: session %d: no channel %d",
1975                     s->self, s->chanid);
1976         debug("session_exit_message: session %d channel %d pid %d",
1977             s->self, s->chanid, s->pid);
1978
1979         if (WIFEXITED(status)) {
1980                 channel_request_start(s->chanid,
1981                     "exit-status", 0);
1982                 packet_put_int(WEXITSTATUS(status));
1983                 packet_send();
1984         } else if (WIFSIGNALED(status)) {
1985                 channel_request_start(s->chanid,
1986                     "exit-signal", 0);
1987                 packet_put_int(WTERMSIG(status));
1988 #ifdef WCOREDUMP
1989                 packet_put_char(WCOREDUMP(status));
1990 #else /* WCOREDUMP */
1991                 packet_put_char(0);
1992 #endif /* WCOREDUMP */
1993                 packet_put_cstring("");
1994                 packet_put_cstring("");
1995                 packet_send();
1996         } else {
1997                 /* Some weird exit cause.  Just exit. */
1998                 packet_disconnect("wait returned status %04x.", status);
1999         }
2000
2001         /* disconnect channel */
2002         debug("session_exit_message: release channel %d", s->chanid);
2003         channel_cancel_cleanup(s->chanid);
2004         /*
2005          * emulate a write failure with 'chan_write_failed', nobody will be
2006          * interested in data we write.
2007          * Note that we must not call 'chan_read_failed', since there could
2008          * be some more data waiting in the pipe.
2009          */
2010         if (c->ostate != CHAN_OUTPUT_CLOSED)
2011                 chan_write_failed(c);
2012         s->chanid = -1;
2013 }
2014
2015 void
2016 session_free(Session *s)
2017 {
2018         debug("session_free: session %d pid %d", s->self, s->pid);
2019         if (s->term)
2020                 xfree(s->term);
2021         if (s->display)
2022                 xfree(s->display);
2023         if (s->auth_data)
2024                 xfree(s->auth_data);
2025         if (s->auth_proto)
2026                 xfree(s->auth_proto);
2027         s->used = 0;
2028 }
2029
2030 void
2031 session_close(Session *s)
2032 {
2033         session_pty_cleanup(s);
2034         session_free(s);
2035         session_proctitle(s);
2036 }
2037
2038 void
2039 session_close_by_pid(pid_t pid, int status)
2040 {
2041         Session *s = session_by_pid(pid);
2042         if (s == NULL) {
2043                 debug("session_close_by_pid: no session for pid %d", s->pid);
2044                 return;
2045         }
2046         if (s->chanid != -1)
2047                 session_exit_message(s, status);
2048         session_close(s);
2049 }
2050
2051 /*
2052  * this is called when a channel dies before
2053  * the session 'child' itself dies
2054  */
2055 void
2056 session_close_by_channel(int id, void *arg)
2057 {
2058         Session *s = session_by_channel(id);
2059         if (s == NULL) {
2060                 debug("session_close_by_channel: no session for channel %d", id);
2061                 return;
2062         }
2063         /* disconnect channel */
2064         channel_cancel_cleanup(s->chanid);
2065         s->chanid = -1;
2066
2067         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
2068         if (s->pid == 0) {
2069                 /* close session immediately */
2070                 session_close(s);
2071         } else {
2072                 /* notify child, delay session cleanup */
2073                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
2074                         error("session_close_by_channel: kill %d: %s",
2075                             s->pid, strerror(errno));
2076         }
2077 }
2078
2079 char *
2080 session_tty_list(void)
2081 {
2082         static char buf[1024];
2083         int i;
2084         buf[0] = '\0';
2085         for(i = 0; i < MAX_SESSIONS; i++) {
2086                 Session *s = &sessions[i];
2087                 if (s->used && s->ttyfd != -1) {
2088                         if (buf[0] != '\0')
2089                                 strlcat(buf, ",", sizeof buf);
2090                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2091                 }
2092         }
2093         if (buf[0] == '\0')
2094                 strlcpy(buf, "notty", sizeof buf);
2095         return buf;
2096 }
2097
2098 void
2099 session_proctitle(Session *s)
2100 {
2101         if (s->pw == NULL)
2102                 error("no user for session %d", s->self);
2103         else
2104                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2105 }
2106
2107 void
2108 do_authenticated2(Authctxt *authctxt)
2109 {
2110
2111         server_loop2();
2112 }