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 1.84 2001/06/11 10:18:24 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 int     session_setup_x11fwd(Session *s);
 127 void    session_close(Session *s);
 128 void    do_exec_pty(Session *s, const char *command);
 129 void    do_exec_no_pty(Session *s, const char *command);
 130 void    do_login(Session *s, const char *command);
 131 #ifdef LOGIN_NEEDS_UTMPX
 132 void    do_pre_login(Session *s);
 133 #endif
 134 void    do_child(Session *s, const char *command);
 135 void    do_motd(void);
 136 int     check_quietlogin(Session *s, const char *command);
 137 void    xauthfile_cleanup_proc(void *pw);
 138
 139 void    do_authenticated1(Authctxt *authctxt);
 140 void    do_authenticated2(Authctxt *authctxt);
 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 /* Local Xauthority file. */
 152 static char *xauthfile;
 153
 154 /* original command from peer. */
 155 char *original_command = NULL;
 156
 157 /* data */
 158 #define MAX_SESSIONS 10
 159 Session sessions[MAX_SESSIONS];
 160
 161 #ifdef WITH_AIXAUTHENTICATE
 162 /* AIX's lastlogin message, set in auth1.c */
 163 char *aixloginmsg;
 164 #endif /* WITH_AIXAUTHENTICATE */
 165
 166 #ifdef HAVE_LOGIN_CAP
 167 static login_cap_t *lc;
 168 #endif
 169
 170 void
 171 do_authenticated(Authctxt *authctxt)
 172 {
 173         /*
 174          * Cancel the alarm we set to limit the time taken for
 175          * authentication.
 176          */
 177         alarm(0);
 178         if (startup_pipe != -1) {
 179                 close(startup_pipe);
 180                 startup_pipe = -1;
 181         }
 182 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 183         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 184                 error("unable to get login class");
 185                 return;
 186         }
 187 #ifdef BSD_AUTH
 188         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 189                 packet_disconnect("Approval failure for %s",
 190                     authctxt->pw->pw_name);
 191         }
 192 #endif
 193 #endif
 194         /* setup the channel layer */
 195         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 196                 channel_permit_all_opens();
 197
 198         if (compat20)
 199                 do_authenticated2(authctxt);
 200         else
 201                 do_authenticated1(authctxt);
 202
 203         /* remote user's local Xauthority file and agent socket */
 204         if (xauthfile)
 205                 xauthfile_cleanup_proc(authctxt->pw);
 206         if (auth_get_socket_name())
 207                 auth_sock_cleanup_proc(authctxt->pw);
 208 }
 209
 210 /*
 211  * Remove local Xauthority file.
 212  */
 213 void
 214 xauthfile_cleanup_proc(void *_pw)
 215 {
 216         struct passwd *pw = _pw;
 217         char *p;
 218
 219         debug("xauthfile_cleanup_proc called");
 220         if (xauthfile != NULL) {
 221                 temporarily_use_uid(pw);
 222                 unlink(xauthfile);
 223                 p = strrchr(xauthfile, '/');
 224                 if (p != NULL) {
 225                         *p = '\0';
 226                         rmdir(xauthfile);
 227                 }
 228                 xfree(xauthfile);
 229                 xauthfile = NULL;
 230                 restore_uid();
 231         }
 232 }
 233
 234 /*
 235  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 236  * dropped connection).
 237  */
 238 void
 239 pty_cleanup_proc(void *session)
 240 {
 241         Session *s=session;
 242         if (s == NULL)
 243                 fatal("pty_cleanup_proc: no session");
 244         debug("pty_cleanup_proc: %s", s->tty);
 245
 246         if (s->pid != 0) {
 247                 /* Record that the user has logged out. */
 248                 record_logout(s->pid, s->tty);
 249         }
 250
 251         /* Release the pseudo-tty. */
 252         pty_release(s->tty);
 253 }
 254
 255 /*
 256  * Prepares for an interactive session.  This is called after the user has
 257  * been successfully authenticated.  During this message exchange, pseudo
 258  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 259  * are requested, etc.
 260  */
 261 void
 262 do_authenticated1(Authctxt *authctxt)
 263 {
 264         Session *s;
 265         char *command;
 266         int success, type, n_bytes, plen, screen_flag, have_pty = 0;
 267         int compression_level = 0, enable_compression_after_reply = 0;
 268         u_int proto_len, data_len, dlen;
 269
 270         s = session_new();
 271         s->pw = authctxt->pw;
 272
 273         /*
 274          * We stay in this loop until the client requests to execute a shell
 275          * or a command.
 276          */
 277         for (;;) {
 278                 success = 0;
 279
 280                 /* Get a packet from the client. */
 281                 type = packet_read(&plen);
 282
 283                 /* Process the packet. */
 284                 switch (type) {
 285                 case SSH_CMSG_REQUEST_COMPRESSION:
 286                         packet_integrity_check(plen, 4, type);
 287                         compression_level = packet_get_int();
 288                         if (compression_level < 1 || compression_level > 9) {
 289                                 packet_send_debug("Received illegal compression level %d.",
 290                                      compression_level);
 291                                 break;
 292                         }
 293                         /* Enable compression after we have responded with SUCCESS. */
 294                         enable_compression_after_reply = 1;
 295                         success = 1;
 296                         break;
 297
 298                 case SSH_CMSG_REQUEST_PTY:
 299                         if (no_pty_flag) {
 300                                 debug("Allocating a pty not permitted for this authentication.");
 301                                 break;
 302                         }
 303                         if (have_pty)
 304                                 packet_disconnect("Protocol error: you already have a pty.");
 305
 306                         debug("Allocating pty.");
 307
 308                         /* Allocate a pty and open it. */
 309                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 310                             sizeof(s->tty))) {
 311                                 error("Failed to allocate pty.");
 312                                 break;
 313                         }
 314                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 315                         pty_setowner(s->pw, s->tty);
 316
 317                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 318                         s->term = packet_get_string(&dlen);
 319                         packet_integrity_check(dlen, strlen(s->term), type);
 320                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 321                         /* Remaining bytes */
 322                         n_bytes = plen - (4 + dlen + 4 * 4);
 323
 324                         if (strcmp(s->term, "") == 0) {
 325                                 xfree(s->term);
 326                                 s->term = NULL;
 327                         }
 328                         /* Get window size from the packet. */
 329                         s->row = packet_get_int();
 330                         s->col = packet_get_int();
 331                         s->xpixel = packet_get_int();
 332                         s->ypixel = packet_get_int();
 333                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 334
 335                         /* Get tty modes from the packet. */
 336                         tty_parse_modes(s->ttyfd, &n_bytes);
 337                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 338
 339                         session_proctitle(s);
 340
 341                         /* Indicate that we now have a pty. */
 342                         success = 1;
 343                         have_pty = 1;
 344                         break;
 345
 346                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 347                         s->auth_proto = packet_get_string(&proto_len);
 348                         s->auth_data = packet_get_string(&data_len);
 349
 350                         screen_flag = packet_get_protocol_flags() &
 351                             SSH_PROTOFLAG_SCREEN_NUMBER;
 352                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 353
 354                         if (packet_remaining() == 4) {
 355                                 if (!screen_flag)
 356                                         debug2("Buggy client: "
 357                                             "X11 screen flag missing");
 358                                 s->screen = packet_get_int();
 359                         } else {
 360                                 s->screen = 0;
 361                         }
 362                         packet_done();
 363                         success = session_setup_x11fwd(s);
 364                         if (!success) {
 365                                 xfree(s->auth_proto);
 366                                 xfree(s->auth_data);
 367                                 s->auth_proto = NULL;
 368                                 s->auth_data = NULL;
 369                         }
 370                         break;
 371
 372                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 373                         if (no_agent_forwarding_flag || compat13) {
 374                                 debug("Authentication agent forwarding not permitted for this authentication.");
 375                                 break;
 376                         }
 377                         debug("Received authentication agent forwarding request.");
 378                         success = auth_input_request_forwarding(s->pw);
 379                         break;
 380
 381                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 382                         if (no_port_forwarding_flag) {
 383                                 debug("Port forwarding not permitted for this authentication.");
 384                                 break;
 385                         }
 386                         if (!options.allow_tcp_forwarding) {
 387                                 debug("Port forwarding not permitted.");
 388                                 break;
 389                         }
 390                         debug("Received TCP/IP port forwarding request.");
 391                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 392                         success = 1;
 393                         break;
 394
 395                 case SSH_CMSG_MAX_PACKET_SIZE:
 396                         if (packet_set_maxsize(packet_get_int()) > 0)
 397                                 success = 1;
 398                         break;
 399
 400                 case SSH_CMSG_EXEC_SHELL:
 401                 case SSH_CMSG_EXEC_CMD:
 402                         if (type == SSH_CMSG_EXEC_CMD) {
 403                                 command = packet_get_string(&dlen);
 404                                 debug("Exec command '%.500s'", command);
 405                                 packet_integrity_check(plen, 4 + dlen, type);
 406                         } else {
 407                                 command = NULL;
 408                                 packet_integrity_check(plen, 0, type);
 409                         }
 410                         if (forced_command != NULL) {
 411                                 original_command = command;
 412                                 command = forced_command;
 413                                 debug("Forced command '%.500s'", forced_command);
 414                         }
 415                         if (have_pty)
 416                                 do_exec_pty(s, command);
 417                         else
 418                                 do_exec_no_pty(s, command);
 419                         if (command != NULL)
 420                                 xfree(command);
 421                         session_close(s);
 422                         return;
 423
 424                 default:
 425                         /*
 426                          * Any unknown messages in this phase are ignored,
 427                          * and a failure message is returned.
 428                          */
 429                         log("Unknown packet type received after authentication: %d", type);
 430                 }
 431                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 432                 packet_send();
 433                 packet_write_wait();
 434
 435                 /* Enable compression now that we have replied if appropriate. */
 436                 if (enable_compression_after_reply) {
 437                         enable_compression_after_reply = 0;
 438                         packet_start_compression(compression_level);
 439                 }
 440         }
 441 }
 442
 443 /*
 444  * This is called to fork and execute a command when we have no tty.  This
 445  * will call do_child from the child, and server_loop from the parent after
 446  * setting up file descriptors and such.
 447  */
 448 void
 449 do_exec_no_pty(Session *s, const char *command)
 450 {
 451         int pid;
 452
 453 #ifdef USE_PIPES
 454         int pin[2], pout[2], perr[2];
 455         /* Allocate pipes for communicating with the program. */
 456         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 457                 packet_disconnect("Could not create pipes: %.100s",
 458                                   strerror(errno));
 459 #else /* USE_PIPES */
 460         int inout[2], err[2];
 461         /* Uses socket pairs to communicate with the program. */
 462         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 463             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 464                 packet_disconnect("Could not create socket pairs: %.100s",
 465                                   strerror(errno));
 466 #endif /* USE_PIPES */
 467         if (s == NULL)
 468                 fatal("do_exec_no_pty: no session");
 469
 470         session_proctitle(s);
 471
 472 #if defined(USE_PAM)
 473         do_pam_setcred(1);
 474 #endif /* USE_PAM */
 475
 476         /* Fork the child. */
 477         if ((pid = fork()) == 0) {
 478                 /* Child.  Reinitialize the log since the pid has changed. */
 479                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 480
 481                 /*
 482                  * Create a new session and process group since the 4.4BSD
 483                  * setlogin() affects the entire process group.
 484                  */
 485                 if (setsid() < 0)
 486                         error("setsid failed: %.100s", strerror(errno));
 487
 488 #ifdef USE_PIPES
 489                 /*
 490                  * Redirect stdin.  We close the parent side of the socket
 491                  * pair, and make the child side the standard input.
 492                  */
 493                 close(pin[1]);
 494                 if (dup2(pin[0], 0) < 0)
 495                         perror("dup2 stdin");
 496                 close(pin[0]);
 497
 498                 /* Redirect stdout. */
 499                 close(pout[0]);
 500                 if (dup2(pout[1], 1) < 0)
 501                         perror("dup2 stdout");
 502                 close(pout[1]);
 503
 504                 /* Redirect stderr. */
 505                 close(perr[0]);
 506                 if (dup2(perr[1], 2) < 0)
 507                         perror("dup2 stderr");
 508                 close(perr[1]);
 509 #else /* USE_PIPES */
 510                 /*
 511                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 512                  * use the same socket, as some programs (particularly rdist)
 513                  * seem to depend on it.
 514                  */
 515                 close(inout[1]);
 516                 close(err[1]);
 517                 if (dup2(inout[0], 0) < 0)      /* stdin */
 518                         perror("dup2 stdin");
 519                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 520                         perror("dup2 stdout");
 521                 if (dup2(err[0], 2) < 0)        /* stderr */
 522                         perror("dup2 stderr");
 523 #endif /* USE_PIPES */
 524
 525                 /* Do processing for the child (exec command etc). */
 526                 do_child(s, command);
 527                 /* NOTREACHED */
 528         }
 529 #ifdef HAVE_CYGWIN
 530         if (is_winnt)
 531                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 532 #endif
 533         if (pid < 0)
 534                 packet_disconnect("fork failed: %.100s", strerror(errno));
 535         s->pid = pid;
 536         /* Set interactive/non-interactive mode. */
 537         packet_set_interactive(s->display != NULL);
 538 #ifdef USE_PIPES
 539         /* We are the parent.  Close the child sides of the pipes. */
 540         close(pin[0]);
 541         close(pout[1]);
 542         close(perr[1]);
 543
 544         if (compat20) {
 545                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 546         } else {
 547                 /* Enter the interactive session. */
 548                 server_loop(pid, pin[1], pout[0], perr[0]);
 549                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 550         }
 551 #else /* USE_PIPES */
 552         /* We are the parent.  Close the child sides of the socket pairs. */
 553         close(inout[0]);
 554         close(err[0]);
 555
 556         /*
 557          * Enter the interactive session.  Note: server_loop must be able to
 558          * handle the case that fdin and fdout are the same.
 559          */
 560         if (compat20) {
 561                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 562         } else {
 563                 server_loop(pid, inout[1], inout[1], err[1]);
 564                 /* server_loop has closed inout[1] and err[1]. */
 565         }
 566 #endif /* USE_PIPES */
 567 }
 568
 569 /*
 570  * This is called to fork and execute a command when we have a tty.  This
 571  * will call do_child from the child, and server_loop from the parent after
 572  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 573  * lastlog, and other such operations.
 574  */
 575 void
 576 do_exec_pty(Session *s, const char *command)
 577 {
 578         int fdout, ptyfd, ttyfd, ptymaster;
 579         pid_t pid;
 580
 581         if (s == NULL)
 582                 fatal("do_exec_pty: no session");
 583         ptyfd = s->ptyfd;
 584         ttyfd = s->ttyfd;
 585
 586 #if defined(USE_PAM)
 587         do_pam_session(s->pw->pw_name, s->tty);
 588         do_pam_setcred(1);
 589 #endif
 590
 591         /* Fork the child. */
 592         if ((pid = fork()) == 0) {
 593                 /* Child.  Reinitialize the log because the pid has changed. */
 594                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 595
 596                 /* Close the master side of the pseudo tty. */
 597                 close(ptyfd);
 598
 599                 /* Make the pseudo tty our controlling tty. */
 600                 pty_make_controlling_tty(&ttyfd, s->tty);
 601
 602                 /* Redirect stdin from the pseudo tty. */
 603                 if (dup2(ttyfd, fileno(stdin)) < 0)
 604                         error("dup2 stdin failed: %.100s", strerror(errno));
 605
 606                 /* Redirect stdout to the pseudo tty. */
 607                 if (dup2(ttyfd, fileno(stdout)) < 0)
 608                         error("dup2 stdin failed: %.100s", strerror(errno));
 609
 610                 /* Redirect stderr to the pseudo tty. */
 611                 if (dup2(ttyfd, fileno(stderr)) < 0)
 612                         error("dup2 stdin failed: %.100s", strerror(errno));
 613
 614                 /* Close the extra descriptor for the pseudo tty. */
 615                 close(ttyfd);
 616
 617                 /* record login, etc. similar to login(1) */
 618 #ifndef HAVE_OSF_SIA
 619                 if (!(options.use_login && command == NULL))
 620                         do_login(s, command);
 621 # ifdef LOGIN_NEEDS_UTMPX
 622                 else
 623                         do_pre_login(s);
 624 # endif
 625 #endif
 626
 627                 /* Do common processing for the child, such as execing the command. */
 628                 do_child(s, command);
 629                 /* NOTREACHED */
 630         }
 631 #ifdef HAVE_CYGWIN
 632         if (is_winnt)
 633                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 634 #endif
 635         if (pid < 0)
 636                 packet_disconnect("fork failed: %.100s", strerror(errno));
 637         s->pid = pid;
 638
 639         /* Parent.  Close the slave side of the pseudo tty. */
 640         close(ttyfd);
 641
 642         /*
 643          * Create another descriptor of the pty master side for use as the
 644          * standard input.  We could use the original descriptor, but this
 645          * simplifies code in server_loop.  The descriptor is bidirectional.
 646          */
 647         fdout = dup(ptyfd);
 648         if (fdout < 0)
 649                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 650
 651         /* we keep a reference to the pty master */
 652         ptymaster = dup(ptyfd);
 653         if (ptymaster < 0)
 654                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 655         s->ptymaster = ptymaster;
 656
 657         /* Enter interactive session. */
 658         packet_set_interactive(1);
 659         if (compat20) {
 660                 session_set_fds(s, ptyfd, fdout, -1);
 661         } else {
 662                 server_loop(pid, ptyfd, fdout, -1);
 663                 /* server_loop _has_ closed ptyfd and fdout. */
 664         }
 665 }
 666
 667 #ifdef LOGIN_NEEDS_UTMPX
 668 void
 669 do_pre_login(Session *s)
 670 {
 671         socklen_t fromlen;
 672         struct sockaddr_storage from;
 673         pid_t pid = getpid();
 674
 675         /*
 676          * Get IP address of client. If the connection is not a socket, let
 677          * the address be 0.0.0.0.
 678          */
 679         memset(&from, 0, sizeof(from));
 680         if (packet_connection_is_on_socket()) {
 681                 fromlen = sizeof(from);
 682                 if (getpeername(packet_get_connection_in(),
 683                      (struct sockaddr *) & from, &fromlen) < 0) {
 684                         debug("getpeername: %.100s", strerror(errno));
 685                         fatal_cleanup();
 686                 }
 687         }
 688
 689         record_utmp_only(pid, s->tty, s->pw->pw_name,
 690             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 691             (struct sockaddr *)&from);
 692 }
 693 #endif
 694
 695 /* administrative, login(1)-like work */
 696 void
 697 do_login(Session *s, const char *command)
 698 {
 699         char *time_string;
 700         char hostname[MAXHOSTNAMELEN];
 701         socklen_t fromlen;
 702         struct sockaddr_storage from;
 703         time_t last_login_time;
 704         struct passwd * pw = s->pw;
 705         pid_t pid = getpid();
 706
 707         /*
 708          * Get IP address of client. If the connection is not a socket, let
 709          * the address be 0.0.0.0.
 710          */
 711         memset(&from, 0, sizeof(from));
 712         if (packet_connection_is_on_socket()) {
 713                 fromlen = sizeof(from);
 714                 if (getpeername(packet_get_connection_in(),
 715                      (struct sockaddr *) & from, &fromlen) < 0) {
 716                         debug("getpeername: %.100s", strerror(errno));
 717                         fatal_cleanup();
 718                 }
 719         }
 720
 721         /* Get the time and hostname when the user last logged in. */
 722         if (options.print_lastlog) {
 723                 hostname[0] = '\0';
 724                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 725                     hostname, sizeof(hostname));
 726         }
 727
 728         /* Record that there was a login on that tty from the remote host. */
 729         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 730             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 731             (struct sockaddr *)&from);
 732
 733 #ifdef USE_PAM
 734         /*
 735          * If password change is needed, do it now.
 736          * This needs to occur before the ~/.hushlogin check.
 737          */
 738         if (is_pam_password_change_required()) {
 739                 print_pam_messages();
 740                 do_pam_chauthtok();
 741         }
 742 #endif
 743
 744         if (check_quietlogin(s, command))
 745                 return;
 746
 747 #ifdef USE_PAM
 748         if (!is_pam_password_change_required())
 749                 print_pam_messages();
 750 #endif /* USE_PAM */
 751 #ifdef WITH_AIXAUTHENTICATE
 752         if (aixloginmsg && *aixloginmsg)
 753                 printf("%s\n", aixloginmsg);
 754 #endif /* WITH_AIXAUTHENTICATE */
 755
 756         if (options.print_lastlog && last_login_time != 0) {
 757                 time_string = ctime(&last_login_time);
 758                 if (strchr(time_string, '\n'))
 759                         *strchr(time_string, '\n') = 0;
 760                 if (strcmp(hostname, "") == 0)
 761                         printf("Last login: %s\r\n", time_string);
 762                 else
 763                         printf("Last login: %s from %s\r\n", time_string, hostname);
 764         }
 765
 766         do_motd();
 767 }
 768
 769 /*
 770  * Display the message of the day.
 771  */
 772 void
 773 do_motd(void)
 774 {
 775         FILE *f;
 776         char buf[256];
 777
 778         if (options.print_motd) {
 779 #ifdef HAVE_LOGIN_CAP
 780                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 781                     "/etc/motd"), "r");
 782 #else
 783                 f = fopen("/etc/motd", "r");
 784 #endif
 785                 if (f) {
 786                         while (fgets(buf, sizeof(buf), f))
 787                                 fputs(buf, stdout);
 788                         fclose(f);
 789                 }
 790         }
 791 }
 792
 793
 794 /*
 795  * Check for quiet login, either .hushlogin or command given.
 796  */
 797 int
 798 check_quietlogin(Session *s, const char *command)
 799 {
 800         char buf[256];
 801         struct passwd * pw = s->pw;
 802         struct stat st;
 803
 804         /* Return 1 if .hushlogin exists or a command given. */
 805         if (command != NULL)
 806                 return 1;
 807         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 808 #ifdef HAVE_LOGIN_CAP
 809         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 810                 return 1;
 811 #else
 812         if (stat(buf, &st) >= 0)
 813                 return 1;
 814 #endif
 815         return 0;
 816 }
 817
 818 /*
 819  * Sets the value of the given variable in the environment.  If the variable
 820  * already exists, its value is overriden.
 821  */
 822 void
 823 child_set_env(char ***envp, u_int *envsizep, const char *name,
 824               const char *value)
 825 {
 826         u_int i, namelen;
 827         char **env;
 828
 829         /*
 830          * Find the slot where the value should be stored.  If the variable
 831          * already exists, we reuse the slot; otherwise we append a new slot
 832          * at the end of the array, expanding if necessary.
 833          */
 834         env = *envp;
 835         namelen = strlen(name);
 836         for (i = 0; env[i]; i++)
 837                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 838                         break;
 839         if (env[i]) {
 840                 /* Reuse the slot. */
 841                 xfree(env[i]);
 842         } else {
 843                 /* New variable.  Expand if necessary. */
 844                 if (i >= (*envsizep) - 1) {
 845                         (*envsizep) += 50;
 846                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 847                 }
 848                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 849                 env[i + 1] = NULL;
 850         }
 851
 852         /* Allocate space and format the variable in the appropriate slot. */
 853         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 854         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 855 }
 856
 857 /*
 858  * Reads environment variables from the given file and adds/overrides them
 859  * into the environment.  If the file does not exist, this does nothing.
 860  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 861  * and assignments of the form name=value.  No other forms are allowed.
 862  */
 863 void
 864 read_environment_file(char ***env, u_int *envsize,
 865                       const char *filename)
 866 {
 867         FILE *f;
 868         char buf[4096];
 869         char *cp, *value;
 870
 871         f = fopen(filename, "r");
 872         if (!f)
 873                 return;
 874
 875         while (fgets(buf, sizeof(buf), f)) {
 876                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 877                         ;
 878                 if (!*cp || *cp == '#' || *cp == '\n')
 879                         continue;
 880                 if (strchr(cp, '\n'))
 881                         *strchr(cp, '\n') = '\0';
 882                 value = strchr(cp, '=');
 883                 if (value == NULL) {
 884                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 885                         continue;
 886                 }
 887                 /*
 888                  * Replace the equals sign by nul, and advance value to
 889                  * the value string.
 890                  */
 891                 *value = '\0';
 892                 value++;
 893                 child_set_env(env, envsize, cp, value);
 894         }
 895         fclose(f);
 896 }
 897
 898 #ifdef USE_PAM
 899 /*
 900  * Sets any environment variables which have been specified by PAM
 901  */
 902 void do_pam_environment(char ***env, int *envsize)
 903 {
 904         char *equals, var_name[512], var_val[512];
 905         char **pam_env;
 906         int i;
 907
 908         if ((pam_env = fetch_pam_environment()) == NULL)
 909                 return;
 910
 911         for(i = 0; pam_env[i] != NULL; i++) {
 912                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 913                         continue;
 914
 915                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 916                         memset(var_name, '\0', sizeof(var_name));
 917                         memset(var_val, '\0', sizeof(var_val));
 918
 919                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 920                         strcpy(var_val, equals + 1);
 921
 922                         debug3("PAM environment: %s=%s", var_name, var_val);
 923
 924                         child_set_env(env, envsize, var_name, var_val);
 925                 }
 926         }
 927 }
 928 #endif /* USE_PAM */
 929
 930 #ifdef HAVE_CYGWIN
 931 void copy_environment(char ***env, int *envsize)
 932 {
 933         char *equals, var_name[512], var_val[512];
 934         int i;
 935
 936         for(i = 0; environ[i] != NULL; i++) {
 937                 if ((equals = strstr(environ[i], "=")) == NULL)
 938                         continue;
 939
 940                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 941                         memset(var_name, '\0', sizeof(var_name));
 942                         memset(var_val, '\0', sizeof(var_val));
 943
 944                         strncpy(var_name, environ[i], equals - environ[i]);
 945                         strcpy(var_val, equals + 1);
 946
 947                         debug3("Copy environment: %s=%s", var_name, var_val);
 948
 949                         child_set_env(env, envsize, var_name, var_val);
 950                 }
 951         }
 952 }
 953 #endif
 954
 955 #if defined(HAVE_GETUSERATTR)
 956 /*
 957  * AIX-specific login initialisation
 958  */
 959 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 960 {
 961         struct rlimit rlim;
 962         int slim, hlim;
 963
 964         getrlimit(resource, &rlim);
 965
 966         slim = 0;
 967         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 968                 if (slim < 0) {
 969                         rlim.rlim_cur = RLIM_INFINITY;
 970                 } else if (slim != 0) {
 971                         /* See the wackiness below */
 972                         if (rlim.rlim_cur == slim * mult)
 973                                 slim = 0;
 974                         else
 975                                 rlim.rlim_cur = slim * mult;
 976                 }
 977         }
 978
 979         hlim = 0;
 980         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 981                 if (hlim < 0) {
 982                         rlim.rlim_max = RLIM_INFINITY;
 983                 } else if (hlim != 0) {
 984                         rlim.rlim_max = hlim * mult;
 985                 }
 986         }
 987
 988         /*
 989          * XXX For cpu and fsize the soft limit is set to the hard limit
 990          * if the hard limit is left at its default value and the soft limit
 991          * is changed from its default value, either by requesting it
 992          * (slim == 0) or by setting it to the current default.  At least
 993          * that's how rlogind does it.  If you're confused you're not alone.
 994          * Bug or feature? AIX 4.3.1.2
 995          */
 996         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 997             && hlim == 0 && slim != 0)
 998                 rlim.rlim_max = rlim.rlim_cur;
 999         /* A specified hard limit limits the soft limit */
1000         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
1001                 rlim.rlim_cur = rlim.rlim_max;
1002         /* A soft limit can increase a hard limit */
1003         else if (rlim.rlim_cur > rlim.rlim_max)
1004                 rlim.rlim_max = rlim.rlim_cur;
1005
1006         if (setrlimit(resource, &rlim) != 0)
1007                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
1008 }
1009
1010 void set_limits_from_userattr(char *user)
1011 {
1012         int mask;
1013         char buf[16];
1014
1015         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
1016         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
1017         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
1018         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
1019         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
1020         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
1021 #if defined(S_UNOFILE)
1022         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1023 #endif
1024
1025         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1026                 /* Convert decimal to octal */
1027                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1028                 if (sscanf(buf, "%o", &mask) == 1)
1029                         umask(mask);
1030         }
1031 }
1032 #endif /* defined(HAVE_GETUSERATTR) */
1033
1034 /*
1035  * Performs common processing for the child, such as setting up the
1036  * environment, closing extra file descriptors, setting the user and group
1037  * ids, and executing the command or shell.
1038  */
1039 void
1040 do_child(Session *s, const char *command)
1041 {
1042         const char *shell, *hostname = NULL, *cp = NULL;
1043         struct passwd * pw = s->pw;
1044         char buf[256];
1045         char cmd[1024];
1046         FILE *f = NULL;
1047         u_int envsize, i;
1048         char **env;
1049         extern char **environ;
1050         struct stat st;
1051         char *argv[10];
1052         int do_xauth;
1053 #ifdef WITH_IRIX_PROJECT
1054         prid_t projid;
1055 #endif /* WITH_IRIX_PROJECT */
1056 #ifdef WITH_IRIX_JOBS
1057         jid_t jid = 0;
1058 #else
1059 #ifdef WITH_IRIX_ARRAY
1060         int jid = 0;
1061 #endif /* WITH_IRIX_ARRAY */
1062 #endif /* WITH_IRIX_JOBS */
1063
1064         do_xauth =
1065             s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1066
1067         /* remove hostkey from the child's memory */
1068         destroy_sensitive_data();
1069
1070         /* login(1) is only called if we execute the login shell */
1071         if (options.use_login && command != NULL)
1072                 options.use_login = 0;
1073
1074 #if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
1075         if (!options.use_login) {
1076 # ifdef HAVE_LOGIN_CAP
1077                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1078                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1079                             _PATH_NOLOGIN), "r");
1080 # else /* HAVE_LOGIN_CAP */
1081                 if (pw->pw_uid)
1082                         f = fopen(_PATH_NOLOGIN, "r");
1083 # endif /* HAVE_LOGIN_CAP */
1084                 if (f) {
1085                         /* /etc/nologin exists.  Print its contents and exit. */
1086                         while (fgets(buf, sizeof(buf), f))
1087                                 fputs(buf, stderr);
1088                         fclose(f);
1089                         exit(254);
1090                 }
1091         }
1092 #endif /* USE_PAM || HAVE_OSF_SIA */
1093
1094         /* Set login name, uid, gid, and groups. */
1095         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1096            switch, so we let login(1) to this for us. */
1097         if (!options.use_login) {
1098 #ifdef HAVE_OSF_SIA
1099                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1100                 if (!check_quietlogin(s, command))
1101                         do_motd();
1102 #else /* HAVE_OSF_SIA */
1103 #ifdef HAVE_CYGWIN
1104                 if (is_winnt) {
1105 #else
1106                 if (getuid() == 0 || geteuid() == 0) {
1107 #endif
1108 # ifdef HAVE_GETUSERATTR
1109                         set_limits_from_userattr(pw->pw_name);
1110 # endif /* HAVE_GETUSERATTR */
1111 # ifdef HAVE_LOGIN_CAP
1112                         if (setusercontext(lc, pw, pw->pw_uid,
1113                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1114                                 perror("unable to set user context");
1115                                 exit(1);
1116                         }
1117 # else /* HAVE_LOGIN_CAP */
1118 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1119                         /* Sets login uid for accounting */
1120                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1121                                 error("setluid: %s", strerror(errno));
1122 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1123
1124                         if (setlogin(pw->pw_name) < 0)
1125                                 error("setlogin failed: %s", strerror(errno));
1126                         if (setgid(pw->pw_gid) < 0) {
1127                                 perror("setgid");
1128                                 exit(1);
1129                         }
1130                         /* Initialize the group list. */
1131                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1132                                 perror("initgroups");
1133                                 exit(1);
1134                         }
1135                         endgrent();
1136 #  ifdef USE_PAM
1137                         /*
1138                          * PAM credentials may take the form of
1139                          * supplementary groups. These will have been
1140                          * wiped by the above initgroups() call.
1141                          * Reestablish them here.
1142                          */
1143                         do_pam_setcred(0);
1144 #  endif /* USE_PAM */
1145 #  ifdef WITH_IRIX_JOBS
1146                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1147                         if (jid == -1) {
1148                                 fatal("Failed to create job container: %.100s",
1149                                       strerror(errno));
1150                         }
1151 #  endif /* WITH_IRIX_JOBS */
1152 #  ifdef WITH_IRIX_ARRAY
1153                         /* initialize array session */
1154                         if (jid == 0) {
1155                                 if (newarraysess() != 0)
1156                                         fatal("Failed to set up new array session: %.100s",
1157                                               strerror(errno));
1158                         }
1159 #  endif /* WITH_IRIX_ARRAY */
1160 #  ifdef WITH_IRIX_PROJECT
1161                         /* initialize irix project info */
1162                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1163                           debug("Failed to get project id, using projid 0");
1164                           projid = 0;
1165                         }
1166                         if (setprid(projid))
1167                           fatal("Failed to initialize project %d for %s: %.100s",
1168                                 (int)projid, pw->pw_name, strerror(errno));
1169 #  endif /* WITH_IRIX_PROJECT */
1170 #ifdef WITH_IRIX_AUDIT
1171                         if (sysconf(_SC_AUDIT)) {
1172                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1173                                 if (satsetid(pw->pw_uid))
1174                                         debug("error setting satid: %.100s", strerror(errno));
1175                         }
1176 #endif /* WITH_IRIX_AUDIT */
1177
1178 #ifdef _AIX
1179                         /*
1180                          * AIX has a "usrinfo" area where logname and
1181                          * other stuff is stored - a few applications
1182                          * actually use this and die if it's not set
1183                          */
1184                         if (s->ttyfd == -1)
1185                                 s->tty[0] = '\0';
1186                         cp = xmalloc(22 + strlen(s->tty) +
1187                             2 * strlen(pw->pw_name));
1188                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1189                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1190                         if (usrinfo(SETUINFO, cp, i) == -1)
1191                                 fatal("Couldn't set usrinfo: %s",
1192                                     strerror(errno));
1193                         debug3("AIX/UsrInfo: set len %d", i);
1194                         xfree(cp);
1195 #endif
1196
1197                         /* Permanently switch to the desired uid. */
1198                         permanently_set_uid(pw);
1199 # endif /* HAVE_LOGIN_CAP */
1200                 }
1201 #endif /* HAVE_OSF_SIA */
1202
1203 #ifdef HAVE_CYGWIN
1204                 if (is_winnt)
1205 #endif
1206                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1207                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1208         }
1209         /*
1210          * Get the shell from the password data.  An empty shell field is
1211          * legal, and means /bin/sh.
1212          */
1213         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1214 #ifdef HAVE_LOGIN_CAP
1215         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1216 #endif
1217
1218 #ifdef AFS
1219         /* Try to get AFS tokens for the local cell. */
1220         if (k_hasafs()) {
1221                 char cell[64];
1222
1223                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1224                         krb_afslog(cell, 0);
1225
1226                 krb_afslog(0, 0);
1227         }
1228 #endif /* AFS */
1229
1230         /* Initialize the environment. */
1231         envsize = 100;
1232         env = xmalloc(envsize * sizeof(char *));
1233         env[0] = NULL;
1234
1235 #ifdef HAVE_CYGWIN
1236         /*
1237          * The Windows environment contains some setting which are
1238          * important for a running system. They must not be dropped.
1239          */
1240         copy_environment(&env, &envsize);
1241 #endif
1242
1243         if (!options.use_login) {
1244                 /* Set basic environment. */
1245                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1246                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1247                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1248 #ifdef HAVE_LOGIN_CAP
1249                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1250                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1251 #else /* HAVE_LOGIN_CAP */
1252 # ifndef HAVE_CYGWIN
1253                 /*
1254                  * There's no standard path on Windows. The path contains
1255                  * important components pointing to the system directories,
1256                  * needed for loading shared libraries. So the path better
1257                  * remains intact here.
1258                  */
1259                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1260 # endif /* HAVE_CYGWIN */
1261 #endif /* HAVE_LOGIN_CAP */
1262
1263                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1264                          _PATH_MAILDIR, pw->pw_name);
1265                 child_set_env(&env, &envsize, "MAIL", buf);
1266
1267                 /* Normal systems set SHELL by default. */
1268                 child_set_env(&env, &envsize, "SHELL", shell);
1269         }
1270         if (getenv("TZ"))
1271                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1272
1273         /* Set custom environment options from RSA authentication. */
1274         while (custom_environment) {
1275                 struct envstring *ce = custom_environment;
1276                 char *s = ce->s;
1277                 int i;
1278                 for (i = 0; s[i] != '=' && s[i]; i++);
1279                 if (s[i] == '=') {
1280                         s[i] = 0;
1281                         child_set_env(&env, &envsize, s, s + i + 1);
1282                 }
1283                 custom_environment = ce->next;
1284                 xfree(ce->s);
1285                 xfree(ce);
1286         }
1287
1288         snprintf(buf, sizeof buf, "%.50s %d %d",
1289                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1290         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1291
1292         if (s->ttyfd != -1)
1293                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1294         if (s->term)
1295                 child_set_env(&env, &envsize, "TERM", s->term);
1296         if (s->display)
1297                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1298         if (original_command)
1299                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1300                     original_command);
1301
1302 #ifdef _AIX
1303         if ((cp = getenv("AUTHSTATE")) != NULL)
1304                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1305         if ((cp = getenv("KRB5CCNAME")) != NULL)
1306                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1307         read_environment_file(&env, &envsize, "/etc/environment");
1308 #endif
1309
1310 #ifdef KRB4
1311         {
1312                 extern char *ticket;
1313
1314                 if (ticket)
1315                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1316         }
1317 #endif /* KRB4 */
1318
1319 #ifdef USE_PAM
1320         /* Pull in any environment variables that may have been set by PAM. */
1321         do_pam_environment(&env, &envsize);
1322 #endif /* USE_PAM */
1323
1324         if (xauthfile)
1325                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1326         if (auth_get_socket_name() != NULL)
1327                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1328                               auth_get_socket_name());
1329
1330         /* read $HOME/.ssh/environment. */
1331         if (!options.use_login) {
1332                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1333                     pw->pw_dir);
1334                 read_environment_file(&env, &envsize, buf);
1335         }
1336         if (debug_flag) {
1337                 /* dump the environment */
1338                 fprintf(stderr, "Environment:\n");
1339                 for (i = 0; env[i]; i++)
1340                         fprintf(stderr, "  %.200s\n", env[i]);
1341         }
1342         /* we have to stash the hostname before we close our socket. */
1343         if (options.use_login)
1344                 hostname = get_remote_name_or_ip(utmp_len,
1345                     options.reverse_mapping_check);
1346         /*
1347          * Close the connection descriptors; note that this is the child, and
1348          * the server will still have the socket open, and it is important
1349          * that we do not shutdown it.  Note that the descriptors cannot be
1350          * closed before building the environment, as we call
1351          * get_remote_ipaddr there.
1352          */
1353         if (packet_get_connection_in() == packet_get_connection_out())
1354                 close(packet_get_connection_in());
1355         else {
1356                 close(packet_get_connection_in());
1357                 close(packet_get_connection_out());
1358         }
1359         /*
1360          * Close all descriptors related to channels.  They will still remain
1361          * open in the parent.
1362          */
1363         /* XXX better use close-on-exec? -markus */
1364         channel_close_all();
1365
1366         /*
1367          * Close any extra file descriptors.  Note that there may still be
1368          * descriptors left by system functions.  They will be closed later.
1369          */
1370         endpwent();
1371
1372         /*
1373          * Close any extra open file descriptors so that we don\'t have them
1374          * hanging around in clients.  Note that we want to do this after
1375          * initgroups, because at least on Solaris 2.3 it leaves file
1376          * descriptors open.
1377          */
1378         for (i = 3; i < 64; i++)
1379                 close(i);
1380
1381         /* Change current directory to the user\'s home directory. */
1382         if (chdir(pw->pw_dir) < 0) {
1383                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1384                         pw->pw_dir, strerror(errno));
1385 #ifdef HAVE_LOGIN_CAP
1386                 if (login_getcapbool(lc, "requirehome", 0))
1387                         exit(1);
1388 #endif
1389         }
1390
1391         /*
1392          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1393          * xauth are run in the proper environment.
1394          */
1395         environ = env;
1396
1397         /*
1398          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1399          * in this order).
1400          */
1401         if (!options.use_login) {
1402                 /* ignore _PATH_SSH_USER_RC for subsystems */
1403                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1404                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1405                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1406                         if (debug_flag)
1407                                 fprintf(stderr, "Running %s\n", cmd);
1408                         f = popen(cmd, "w");
1409                         if (f) {
1410                                 if (do_xauth)
1411                                         fprintf(f, "%s %s\n", s->auth_proto,
1412                                             s->auth_data);
1413                                 pclose(f);
1414                         } else
1415                                 fprintf(stderr, "Could not run %s\n",
1416                                     _PATH_SSH_USER_RC);
1417                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1418                         if (debug_flag)
1419                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1420                                     _PATH_SSH_SYSTEM_RC);
1421                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1422                         if (f) {
1423                                 if (do_xauth)
1424                                         fprintf(f, "%s %s\n", s->auth_proto,
1425                                             s->auth_data);
1426                                 pclose(f);
1427                         } else
1428                                 fprintf(stderr, "Could not run %s\n",
1429                                     _PATH_SSH_SYSTEM_RC);
1430                 } else if (do_xauth && options.xauth_location != NULL) {
1431                         /* Add authority data to .Xauthority if appropriate. */
1432                         char *screen = strchr(s->display, ':');
1433
1434                         if (debug_flag) {
1435                                 fprintf(stderr,
1436                                     "Running %.100s add "
1437                                     "%.100s %.100s %.100s\n",
1438                                     options.xauth_location, s->display,
1439                                     s->auth_proto, s->auth_data);
1440                                 if (screen != NULL)
1441                                         fprintf(stderr,
1442                                             "Adding %.*s/unix%s %s %s\n",
1443                                             (int)(screen - s->display),
1444                                             s->display, screen,
1445                                             s->auth_proto, s->auth_data);
1446                         }
1447                         snprintf(cmd, sizeof cmd, "%s -q -",
1448                             options.xauth_location);
1449                         f = popen(cmd, "w");
1450                         if (f) {
1451                                 fprintf(f, "add %s %s %s\n", s->display,
1452                                     s->auth_proto, s->auth_data);
1453                                 if (screen != NULL)
1454                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1455                                             (int)(screen - s->display),
1456                                             s->display, screen,
1457                                             s->auth_proto,
1458                                             s->auth_data);
1459                                 pclose(f);
1460                         } else {
1461                                 fprintf(stderr, "Could not run %s\n",
1462                                     cmd);
1463                         }
1464                 }
1465                 /* Get the last component of the shell name. */
1466                 cp = strrchr(shell, '/');
1467                 if (cp)
1468                         cp++;
1469                 else
1470                         cp = shell;
1471         }
1472
1473         /* restore SIGPIPE for child */
1474         signal(SIGPIPE,  SIG_DFL);
1475
1476         /*
1477          * If we have no command, execute the shell.  In this case, the shell
1478          * name to be passed in argv[0] is preceded by '-' to indicate that
1479          * this is a login shell.
1480          */
1481         if (!command) {
1482                 if (!options.use_login) {
1483                         char buf[256];
1484
1485                         /*
1486                          * Check for mail if we have a tty and it was enabled
1487                          * in server options.
1488                          */
1489                         if (s->ttyfd != -1 && options.check_mail) {
1490                                 char *mailbox;
1491                                 struct stat mailstat;
1492
1493                                 mailbox = getenv("MAIL");
1494                                 if (mailbox != NULL) {
1495                                         if (stat(mailbox, &mailstat) != 0 ||
1496                                             mailstat.st_size == 0)
1497                                                 printf("No mail.\n");
1498                                         else if (mailstat.st_mtime < mailstat.st_atime)
1499                                                 printf("You have mail.\n");
1500                                         else
1501                                                 printf("You have new mail.\n");
1502                                 }
1503                         }
1504                         /* Start the shell.  Set initial character to '-'. */
1505                         buf[0] = '-';
1506                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1507                         buf[sizeof(buf) - 1] = 0;
1508
1509                         /* Execute the shell. */
1510                         argv[0] = buf;
1511                         argv[1] = NULL;
1512                         execve(shell, argv, env);
1513
1514                         /* Executing the shell failed. */
1515                         perror(shell);
1516                         exit(1);
1517
1518                 } else {
1519                         /* Launch login(1). */
1520
1521                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1522 #ifdef LOGIN_NEEDS_TERM
1523                              s->term? s->term : "unknown",
1524 #endif
1525                              "-p", "-f", "--", pw->pw_name, NULL);
1526
1527                         /* Login couldn't be executed, die. */
1528
1529                         perror("login");
1530                         exit(1);
1531                 }
1532         }
1533         /*
1534          * Execute the command using the user's shell.  This uses the -c
1535          * option to execute the command.
1536          */
1537         argv[0] = (char *) cp;
1538         argv[1] = "-c";
1539         argv[2] = (char *) command;
1540         argv[3] = NULL;
1541         execve(shell, argv, env);
1542         perror(shell);
1543         exit(1);
1544 }
1545
1546 Session *
1547 session_new(void)
1548 {
1549         int i;
1550         static int did_init = 0;
1551         if (!did_init) {
1552                 debug("session_new: init");
1553                 for(i = 0; i < MAX_SESSIONS; i++) {
1554                         sessions[i].used = 0;
1555                         sessions[i].self = i;
1556                 }
1557                 did_init = 1;
1558         }
1559         for(i = 0; i < MAX_SESSIONS; i++) {
1560                 Session *s = &sessions[i];
1561                 if (! s->used) {
1562                         memset(s, 0, sizeof(*s));
1563                         s->chanid = -1;
1564                         s->ptyfd = -1;
1565                         s->ttyfd = -1;
1566                         s->used = 1;
1567                         debug("session_new: session %d", i);
1568                         return s;
1569                 }
1570         }
1571         return NULL;
1572 }
1573
1574 void
1575 session_dump(void)
1576 {
1577         int i;
1578         for(i = 0; i < MAX_SESSIONS; i++) {
1579                 Session *s = &sessions[i];
1580                 debug("dump: used %d session %d %p channel %d pid %d",
1581                     s->used,
1582                     s->self,
1583                     s,
1584                     s->chanid,
1585                     s->pid);
1586         }
1587 }
1588
1589 int
1590 session_open(int chanid)
1591 {
1592         Session *s = session_new();
1593         debug("session_open: channel %d", chanid);
1594         if (s == NULL) {
1595                 error("no more sessions");
1596                 return 0;
1597         }
1598         s->pw = auth_get_user();
1599         if (s->pw == NULL)
1600                 fatal("no user for session %d", s->self);
1601         debug("session_open: session %d: link with channel %d", s->self, chanid);
1602         s->chanid = chanid;
1603         return 1;
1604 }
1605
1606 Session *
1607 session_by_channel(int id)
1608 {
1609         int i;
1610         for(i = 0; i < MAX_SESSIONS; i++) {
1611                 Session *s = &sessions[i];
1612                 if (s->used && s->chanid == id) {
1613                         debug("session_by_channel: session %d channel %d", i, id);
1614                         return s;
1615                 }
1616         }
1617         debug("session_by_channel: unknown channel %d", id);
1618         session_dump();
1619         return NULL;
1620 }
1621
1622 Session *
1623 session_by_pid(pid_t pid)
1624 {
1625         int i;
1626         debug("session_by_pid: pid %d", pid);
1627         for(i = 0; i < MAX_SESSIONS; i++) {
1628                 Session *s = &sessions[i];
1629                 if (s->used && s->pid == pid)
1630                         return s;
1631         }
1632         error("session_by_pid: unknown pid %d", pid);
1633         session_dump();
1634         return NULL;
1635 }
1636
1637 int
1638 session_window_change_req(Session *s)
1639 {
1640         s->col = packet_get_int();
1641         s->row = packet_get_int();
1642         s->xpixel = packet_get_int();
1643         s->ypixel = packet_get_int();
1644         packet_done();
1645         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1646         return 1;
1647 }
1648
1649 int
1650 session_pty_req(Session *s)
1651 {
1652         u_int len;
1653         int n_bytes;
1654
1655         if (no_pty_flag)
1656                 return 0;
1657         if (s->ttyfd != -1)
1658                 return 0;
1659         s->term = packet_get_string(&len);
1660         s->col = packet_get_int();
1661         s->row = packet_get_int();
1662         s->xpixel = packet_get_int();
1663         s->ypixel = packet_get_int();
1664
1665         if (strcmp(s->term, "") == 0) {
1666                 xfree(s->term);
1667                 s->term = NULL;
1668         }
1669         /* Allocate a pty and open it. */
1670         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1671                 xfree(s->term);
1672                 s->term = NULL;
1673                 s->ptyfd = -1;
1674                 s->ttyfd = -1;
1675                 error("session_pty_req: session %d alloc failed", s->self);
1676                 return 0;
1677         }
1678         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1679         /*
1680          * Add a cleanup function to clear the utmp entry and record logout
1681          * time in case we call fatal() (e.g., the connection gets closed).
1682          */
1683         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1684         pty_setowner(s->pw, s->tty);
1685         /* Get window size from the packet. */
1686         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1687
1688         /* Get tty modes from the packet. */
1689         tty_parse_modes(s->ttyfd, &n_bytes);
1690         packet_done();
1691
1692         session_proctitle(s);
1693
1694         return 1;
1695 }
1696
1697 int
1698 session_subsystem_req(Session *s)
1699 {
1700         u_int len;
1701         int success = 0;
1702         char *subsys = packet_get_string(&len);
1703         int i;
1704
1705         packet_done();
1706         log("subsystem request for %s", subsys);
1707
1708         for (i = 0; i < options.num_subsystems; i++) {
1709                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1710                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1711                         s->is_subsystem = 1;
1712                         do_exec_no_pty(s, options.subsystem_command[i]);
1713                         success = 1;
1714                 }
1715         }
1716
1717         if (!success)
1718                 log("subsystem request for %s failed, subsystem not found", subsys);
1719
1720         xfree(subsys);
1721         return success;
1722 }
1723
1724 int
1725 session_x11_req(Session *s)
1726 {
1727         int success;
1728
1729         s->single_connection = packet_get_char();
1730         s->auth_proto = packet_get_string(NULL);
1731         s->auth_data = packet_get_string(NULL);
1732         s->screen = packet_get_int();
1733         packet_done();
1734
1735         success = session_setup_x11fwd(s);
1736         if (!success) {
1737                 xfree(s->auth_proto);
1738                 xfree(s->auth_data);
1739                 s->auth_proto = NULL;
1740                 s->auth_data = NULL;
1741         }
1742         return success;
1743 }
1744
1745 int
1746 session_shell_req(Session *s)
1747 {
1748         /* if forced_command == NULL, the shell is execed */
1749         char *shell = forced_command;
1750         packet_done();
1751         if (s->ttyfd == -1)
1752                 do_exec_no_pty(s, shell);
1753         else
1754                 do_exec_pty(s, shell);
1755         return 1;
1756 }
1757
1758 int
1759 session_exec_req(Session *s)
1760 {
1761         u_int len;
1762         char *command = packet_get_string(&len);
1763         packet_done();
1764         if (forced_command) {
1765                 original_command = command;
1766                 command = forced_command;
1767                 debug("Forced command '%.500s'", forced_command);
1768         }
1769         if (s->ttyfd == -1)
1770                 do_exec_no_pty(s, command);
1771         else
1772                 do_exec_pty(s, command);
1773         if (forced_command == NULL)
1774                 xfree(command);
1775         return 1;
1776 }
1777
1778 int
1779 session_auth_agent_req(Session *s)
1780 {
1781         static int called = 0;
1782         packet_done();
1783         if (no_agent_forwarding_flag) {
1784                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1785                 return 0;
1786         }
1787         if (called) {
1788                 return 0;
1789         } else {
1790                 called = 1;
1791                 return auth_input_request_forwarding(s->pw);
1792         }
1793 }
1794
1795 void
1796 session_input_channel_req(int id, void *arg)
1797 {
1798         u_int len;
1799         int reply;
1800         int success = 0;
1801         char *rtype;
1802         Session *s;
1803         Channel *c;
1804
1805         rtype = packet_get_string(&len);
1806         reply = packet_get_char();
1807
1808         s = session_by_channel(id);
1809         if (s == NULL)
1810                 fatal("session_input_channel_req: channel %d: no session", id);
1811         c = channel_lookup(id);
1812         if (c == NULL)
1813                 fatal("session_input_channel_req: channel %d: bad channel", id);
1814
1815         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1816             s->self, id, rtype, reply);
1817
1818         /*
1819          * a session is in LARVAL state until a shell, a command
1820          * or a subsystem is executed
1821          */
1822         if (c->type == SSH_CHANNEL_LARVAL) {
1823                 if (strcmp(rtype, "shell") == 0) {
1824                         success = session_shell_req(s);
1825                 } else if (strcmp(rtype, "exec") == 0) {
1826                         success = session_exec_req(s);
1827                 } else if (strcmp(rtype, "pty-req") == 0) {
1828                         success =  session_pty_req(s);
1829                 } else if (strcmp(rtype, "x11-req") == 0) {
1830                         success = session_x11_req(s);
1831                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1832                         success = session_auth_agent_req(s);
1833                 } else if (strcmp(rtype, "subsystem") == 0) {
1834                         success = session_subsystem_req(s);
1835                 }
1836         }
1837         if (strcmp(rtype, "window-change") == 0) {
1838                 success = session_window_change_req(s);
1839         }
1840
1841         if (reply) {
1842                 packet_start(success ?
1843                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1844                 packet_put_int(c->remote_id);
1845                 packet_send();
1846         }
1847         xfree(rtype);
1848 }
1849
1850 void
1851 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1852 {
1853         if (!compat20)
1854                 fatal("session_set_fds: called for proto != 2.0");
1855         /*
1856          * now that have a child and a pipe to the child,
1857          * we can activate our channel and register the fd's
1858          */
1859         if (s->chanid == -1)
1860                 fatal("no channel for session %d", s->self);
1861         channel_set_fds(s->chanid,
1862             fdout, fdin, fderr,
1863             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1864             1);
1865 }
1866
1867 void
1868 session_pty_cleanup(Session *s)
1869 {
1870         if (s == NULL || s->ttyfd == -1)
1871                 return;
1872
1873         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1874
1875         /* Cancel the cleanup function. */
1876         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1877
1878         /* Record that the user has logged out. */
1879         record_logout(s->pid, s->tty);
1880
1881         /* Release the pseudo-tty. */
1882         pty_release(s->tty);
1883
1884         /*
1885          * Close the server side of the socket pairs.  We must do this after
1886          * the pty cleanup, so that another process doesn't get this pty
1887          * while we're still cleaning up.
1888          */
1889         if (close(s->ptymaster) < 0)
1890                 error("close(s->ptymaster): %s", strerror(errno));
1891 }
1892
1893 void
1894 session_exit_message(Session *s, int status)
1895 {
1896         Channel *c;
1897         if (s == NULL)
1898                 fatal("session_close: no session");
1899         c = channel_lookup(s->chanid);
1900         if (c == NULL)
1901                 fatal("session_close: session %d: no channel %d",
1902                     s->self, s->chanid);
1903         debug("session_exit_message: session %d channel %d pid %d",
1904             s->self, s->chanid, s->pid);
1905
1906         if (WIFEXITED(status)) {
1907                 channel_request_start(s->chanid,
1908                     "exit-status", 0);
1909                 packet_put_int(WEXITSTATUS(status));
1910                 packet_send();
1911         } else if (WIFSIGNALED(status)) {
1912                 channel_request_start(s->chanid,
1913                     "exit-signal", 0);
1914                 packet_put_int(WTERMSIG(status));
1915 #ifdef WCOREDUMP
1916                 packet_put_char(WCOREDUMP(status));
1917 #else /* WCOREDUMP */
1918                 packet_put_char(0);
1919 #endif /* WCOREDUMP */
1920                 packet_put_cstring("");
1921                 packet_put_cstring("");
1922                 packet_send();
1923         } else {
1924                 /* Some weird exit cause.  Just exit. */
1925                 packet_disconnect("wait returned status %04x.", status);
1926         }
1927
1928         /* disconnect channel */
1929         debug("session_exit_message: release channel %d", s->chanid);
1930         channel_cancel_cleanup(s->chanid);
1931         /*
1932          * emulate a write failure with 'chan_write_failed', nobody will be
1933          * interested in data we write.
1934          * Note that we must not call 'chan_read_failed', since there could
1935          * be some more data waiting in the pipe.
1936          */
1937         if (c->ostate != CHAN_OUTPUT_CLOSED)
1938                 chan_write_failed(c);
1939         s->chanid = -1;
1940 }
1941
1942 void
1943 session_free(Session *s)
1944 {
1945         debug("session_free: session %d pid %d", s->self, s->pid);
1946         if (s->term)
1947                 xfree(s->term);
1948         if (s->display)
1949                 xfree(s->display);
1950         if (s->auth_data)
1951                 xfree(s->auth_data);
1952         if (s->auth_proto)
1953                 xfree(s->auth_proto);
1954         s->used = 0;
1955 }
1956
1957 void
1958 session_close(Session *s)
1959 {
1960         session_pty_cleanup(s);
1961         session_free(s);
1962         session_proctitle(s);
1963 }
1964
1965 void
1966 session_close_by_pid(pid_t pid, int status)
1967 {
1968         Session *s = session_by_pid(pid);
1969         if (s == NULL) {
1970                 debug("session_close_by_pid: no session for pid %d", s->pid);
1971                 return;
1972         }
1973         if (s->chanid != -1)
1974                 session_exit_message(s, status);
1975         session_close(s);
1976 }
1977
1978 /*
1979  * this is called when a channel dies before
1980  * the session 'child' itself dies
1981  */
1982 void
1983 session_close_by_channel(int id, void *arg)
1984 {
1985         Session *s = session_by_channel(id);
1986         if (s == NULL) {
1987                 debug("session_close_by_channel: no session for channel %d", id);
1988                 return;
1989         }
1990         /* disconnect channel */
1991         channel_cancel_cleanup(s->chanid);
1992         s->chanid = -1;
1993
1994         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1995         if (s->pid == 0) {
1996                 /* close session immediately */
1997                 session_close(s);
1998         } else {
1999                 /* notify child, delay session cleanup */
2000                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
2001                         error("session_close_by_channel: kill %d: %s",
2002                             s->pid, strerror(errno));
2003         }
2004 }
2005
2006 char *
2007 session_tty_list(void)
2008 {
2009         static char buf[1024];
2010         int i;
2011         buf[0] = '\0';
2012         for(i = 0; i < MAX_SESSIONS; i++) {
2013                 Session *s = &sessions[i];
2014                 if (s->used && s->ttyfd != -1) {
2015                         if (buf[0] != '\0')
2016                                 strlcat(buf, ",", sizeof buf);
2017                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2018                 }
2019         }
2020         if (buf[0] == '\0')
2021                 strlcpy(buf, "notty", sizeof buf);
2022         return buf;
2023 }
2024
2025 void
2026 session_proctitle(Session *s)
2027 {
2028         if (s->pw == NULL)
2029                 error("no user for session %d", s->self);
2030         else
2031                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2032 }
2033
2034 int
2035 session_setup_x11fwd(Session *s)
2036 {
2037         int fd;
2038         struct stat st;
2039
2040         if (no_x11_forwarding_flag) {
2041                 packet_send_debug("X11 forwarding disabled in user configuration file.");
2042                 return 0;
2043         }
2044         if (!options.x11_forwarding) {
2045                 debug("X11 forwarding disabled in server configuration file.");
2046                 return 0;
2047         }
2048         if (!options.xauth_location ||
2049             (stat(options.xauth_location, &st) == -1)) {
2050                 packet_send_debug("No xauth program; cannot forward with spoofing.");
2051                 return 0;
2052         }
2053         if (s->display != NULL || xauthfile != NULL) {
2054                 debug("X11 display already set.");
2055                 return 0;
2056         }
2057         xauthfile = xmalloc(MAXPATHLEN);
2058         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
2059         temporarily_use_uid(s->pw);
2060         if (mkdtemp(xauthfile) == NULL) {
2061                 error("private X11 dir: mkdtemp %s failed: %s",
2062                     xauthfile, strerror(errno));
2063                 restore_uid();
2064                 xfree(xauthfile);
2065                 xauthfile = NULL;
2066                 return 0;
2067         }
2068         strlcat(xauthfile, "/cookies", MAXPATHLEN);
2069         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
2070         if (fd >= 0)
2071                 close(fd);
2072         restore_uid();
2073         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
2074         if (s->display == NULL) {
2075                 xauthfile_cleanup_proc(s->pw);
2076                 return 0;
2077         }
2078         fatal_add_cleanup(xauthfile_cleanup_proc, s->pw);
2079         return 1;
2080 }
2081
2082 void
2083 do_authenticated2(Authctxt *authctxt)
2084 {
2085         server_loop2();
2086 }