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 1.56 2001/02/16 14:03:43 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 "nchan.h"
  50 #include "bufaux.h"
  51 #include "auth.h"
  52 #include "auth-options.h"
  53 #include "pathnames.h"
  54 #include "log.h"
  55 #include "servconf.h"
  56 #include "sshlogin.h"
  57 #include "serverloop.h"
  58 #include "canohost.h"
  59 #include "session.h"
  60
  61 #ifdef WITH_IRIX_PROJECT
  62 #include <proj.h>
  63 #endif /* WITH_IRIX_PROJECT */
  64 #ifdef WITH_IRIX_JOBS
  65 #include <sys/resource.h>
  66 #endif
  67 #ifdef WITH_IRIX_AUDIT
  68 #include <sat.h>
  69 #endif /* WITH_IRIX_AUDIT */
  70
  71 #if defined(HAVE_USERSEC_H)
  72 #include <usersec.h>
  73 #endif
  74
  75 #ifdef HAVE_CYGWIN
  76 #include <windows.h>
  77 #include <sys/cygwin.h>
  78 #define is_winnt       (GetVersion() < 0x80000000)
  79 #endif
  80
  81 /* AIX limits */
  82 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  83 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  84 # define S_UCPU_HARD  S_UCPU "_hard"
  85 # define S_UDATA_HARD  S_UDATA "_hard"
  86 # define S_USTACK_HARD  S_USTACK "_hard"
  87 # define S_URSS_HARD  S_URSS "_hard"
  88 # define S_UCORE_HARD  S_UCORE "_hard"
  89 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  90 #endif
  91
  92 /* types */
  93
  94 #define TTYSZ 64
  95 typedef struct Session Session;
  96 struct Session {
  97         int     used;
  98         int     self;
  99         int     extended;
 100         struct  passwd *pw;
 101         pid_t   pid;
 102         /* tty */
 103         char    *term;
 104         int     ptyfd, ttyfd, ptymaster;
 105         int     row, col, xpixel, ypixel;
 106         char    tty[TTYSZ];
 107         /* X11 */
 108         char    *display;
 109         int     screen;
 110         char    *auth_proto;
 111         char    *auth_data;
 112         int     single_connection;
 113         /* proto 2 */
 114         int     chanid;
 115 };
 116
 117 /* func */
 118
 119 Session *session_new(void);
 120 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 121 void    session_pty_cleanup(Session *s);
 122 void    session_proctitle(Session *s);
 123 void    do_exec_pty(Session *s, const char *command, struct passwd * pw);
 124 void    do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
 125 void    do_login(Session *s, const char *command);
 126
 127 void
 128 do_child(const char *command, struct passwd * pw, const char *term,
 129     const char *display, const char *auth_proto,
 130     const char *auth_data, const char *ttyname);
 131
 132 /* import */
 133 extern ServerOptions options;
 134 extern char *__progname;
 135 extern int log_stderr;
 136 extern int debug_flag;
 137 extern u_int utmp_len;
 138
 139 extern int startup_pipe;
 140
 141 /* Local Xauthority file. */
 142 static char *xauthfile;
 143
 144 /* original command from peer. */
 145 char *original_command = NULL;
 146
 147 /* data */
 148 #define MAX_SESSIONS 10
 149 Session sessions[MAX_SESSIONS];
 150
 151 #ifdef WITH_AIXAUTHENTICATE
 152 /* AIX's lastlogin message, set in auth1.c */
 153 char *aixloginmsg;
 154 #endif /* WITH_AIXAUTHENTICATE */
 155
 156 #ifdef HAVE_LOGIN_CAP
 157 static login_cap_t *lc;
 158 #endif
 159
 160 /*
 161  * Remove local Xauthority file.
 162  */
 163 void
 164 xauthfile_cleanup_proc(void *ignore)
 165 {
 166         debug("xauthfile_cleanup_proc called");
 167
 168         if (xauthfile != NULL) {
 169                 char *p;
 170                 unlink(xauthfile);
 171                 p = strrchr(xauthfile, '/');
 172                 if (p != NULL) {
 173                         *p = '\0';
 174                         rmdir(xauthfile);
 175                 }
 176                 xfree(xauthfile);
 177                 xauthfile = NULL;
 178         }
 179 }
 180
 181 /*
 182  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 183  * dropped connection).
 184  */
 185 void
 186 pty_cleanup_proc(void *session)
 187 {
 188         Session *s=session;
 189         if (s == NULL)
 190                 fatal("pty_cleanup_proc: no session");
 191         debug("pty_cleanup_proc: %s", s->tty);
 192
 193         if (s->pid != 0) {
 194                 /* Record that the user has logged out. */
 195                 record_logout(s->pid, s->tty);
 196         }
 197
 198         /* Release the pseudo-tty. */
 199         pty_release(s->tty);
 200 }
 201
 202 /*
 203  * Prepares for an interactive session.  This is called after the user has
 204  * been successfully authenticated.  During this message exchange, pseudo
 205  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 206  * are requested, etc.
 207  */
 208 void
 209 do_authenticated(struct passwd * pw)
 210 {
 211         Session *s;
 212         int type, fd;
 213         int compression_level = 0, enable_compression_after_reply = 0;
 214         int have_pty = 0;
 215         char *command;
 216         int n_bytes;
 217         int plen;
 218         u_int proto_len, data_len, dlen;
 219
 220         /*
 221          * Cancel the alarm we set to limit the time taken for
 222          * authentication.
 223          */
 224         alarm(0);
 225         if (startup_pipe != -1) {
 226                 close(startup_pipe);
 227                 startup_pipe = -1;
 228         }
 229
 230         /*
 231          * Inform the channel mechanism that we are the server side and that
 232          * the client may request to connect to any port at all. (The user
 233          * could do it anyway, and we wouldn\'t know what is permitted except
 234          * by the client telling us, so we can equally well trust the client
 235          * not to request anything bogus.)
 236          */
 237         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 238                 channel_permit_all_opens();
 239
 240         s = session_new();
 241         s->pw = pw;
 242
 243 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 244         if ((lc = login_getclass(pw->pw_class)) == NULL) {
 245                 error("unable to get login class");
 246                 return;
 247         }
 248 #endif
 249
 250         /*
 251          * We stay in this loop until the client requests to execute a shell
 252          * or a command.
 253          */
 254         for (;;) {
 255                 int success = 0;
 256
 257                 /* Get a packet from the client. */
 258                 type = packet_read(&plen);
 259
 260                 /* Process the packet. */
 261                 switch (type) {
 262                 case SSH_CMSG_REQUEST_COMPRESSION:
 263                         packet_integrity_check(plen, 4, type);
 264                         compression_level = packet_get_int();
 265                         if (compression_level < 1 || compression_level > 9) {
 266                                 packet_send_debug("Received illegal compression level %d.",
 267                                      compression_level);
 268                                 break;
 269                         }
 270                         /* Enable compression after we have responded with SUCCESS. */
 271                         enable_compression_after_reply = 1;
 272                         success = 1;
 273                         break;
 274
 275                 case SSH_CMSG_REQUEST_PTY:
 276                         if (no_pty_flag) {
 277                                 debug("Allocating a pty not permitted for this authentication.");
 278                                 break;
 279                         }
 280                         if (have_pty)
 281                                 packet_disconnect("Protocol error: you already have a pty.");
 282
 283                         debug("Allocating pty.");
 284
 285                         /* Allocate a pty and open it. */
 286                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 287                             sizeof(s->tty))) {
 288                                 error("Failed to allocate pty.");
 289                                 break;
 290                         }
 291                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 292                         pty_setowner(pw, s->tty);
 293
 294                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 295                         s->term = packet_get_string(&dlen);
 296                         packet_integrity_check(dlen, strlen(s->term), type);
 297                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 298                         /* Remaining bytes */
 299                         n_bytes = plen - (4 + dlen + 4 * 4);
 300
 301                         if (strcmp(s->term, "") == 0) {
 302                                 xfree(s->term);
 303                                 s->term = NULL;
 304                         }
 305                         /* Get window size from the packet. */
 306                         s->row = packet_get_int();
 307                         s->col = packet_get_int();
 308                         s->xpixel = packet_get_int();
 309                         s->ypixel = packet_get_int();
 310                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 311
 312                         /* Get tty modes from the packet. */
 313                         tty_parse_modes(s->ttyfd, &n_bytes);
 314                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 315
 316                         session_proctitle(s);
 317
 318                         /* Indicate that we now have a pty. */
 319                         success = 1;
 320                         have_pty = 1;
 321                         break;
 322
 323                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 324                         if (!options.x11_forwarding) {
 325                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 326                                 break;
 327                         }
 328                         if (!options.xauth_location) {
 329                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 330                                 break;
 331                         }
 332                         if (no_x11_forwarding_flag) {
 333                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 334                                 break;
 335                         }
 336                         debug("Received request for X11 forwarding with auth spoofing.");
 337                         if (s->display != NULL)
 338                                 packet_disconnect("Protocol error: X11 display already set.");
 339
 340                         s->auth_proto = packet_get_string(&proto_len);
 341                         s->auth_data = packet_get_string(&data_len);
 342
 343                         if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) {
 344                                 debug2("SSH_PROTOFLAG_SCREEN_NUMBER == true");
 345                                 packet_integrity_check(plen,
 346                                     4 + proto_len + 4 + data_len + 4, type);
 347                                 s->screen = packet_get_int();
 348                         } else {
 349                                 debug2("SSH_PROTOFLAG_SCREEN_NUMBER == false");
 350                                 packet_integrity_check(plen,
 351                                     4 + proto_len + 4 + data_len, type);
 352                                 s->screen = 0;
 353                         }
 354                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 355
 356                         if (s->display == NULL)
 357                                 break;
 358
 359                         /* Setup to always have a local .Xauthority. */
 360                         xauthfile = xmalloc(MAXPATHLEN);
 361                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 362                         temporarily_use_uid(pw->pw_uid);
 363                         if (mkdtemp(xauthfile) == NULL) {
 364                                 restore_uid();
 365                                 error("private X11 dir: mkdtemp %s failed: %s",
 366                                     xauthfile, strerror(errno));
 367                                 xfree(xauthfile);
 368                                 xauthfile = NULL;
 369                                 /* XXXX remove listening channels */
 370                                 break;
 371                         }
 372                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 373                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 374                         if (fd >= 0)
 375                                 close(fd);
 376                         restore_uid();
 377                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 378                         success = 1;
 379                         break;
 380
 381                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 382                         if (no_agent_forwarding_flag || compat13) {
 383                                 debug("Authentication agent forwarding not permitted for this authentication.");
 384                                 break;
 385                         }
 386                         debug("Received authentication agent forwarding request.");
 387                         success = auth_input_request_forwarding(pw);
 388                         break;
 389
 390                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 391                         if (no_port_forwarding_flag) {
 392                                 debug("Port forwarding not permitted for this authentication.");
 393                                 break;
 394                         }
 395                         if (!options.allow_tcp_forwarding) {
 396                                 debug("Port forwarding not permitted.");
 397                                 break;
 398                         }
 399                         debug("Received TCP/IP port forwarding request.");
 400                         channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
 401                         success = 1;
 402                         break;
 403
 404                 case SSH_CMSG_MAX_PACKET_SIZE:
 405                         if (packet_set_maxsize(packet_get_int()) > 0)
 406                                 success = 1;
 407                         break;
 408
 409                 case SSH_CMSG_EXEC_SHELL:
 410                 case SSH_CMSG_EXEC_CMD:
 411                         if (type == SSH_CMSG_EXEC_CMD) {
 412                                 command = packet_get_string(&dlen);
 413                                 debug("Exec command '%.500s'", command);
 414                                 packet_integrity_check(plen, 4 + dlen, type);
 415                         } else {
 416                                 command = NULL;
 417                                 packet_integrity_check(plen, 0, type);
 418                         }
 419                         if (forced_command != NULL) {
 420                                 original_command = command;
 421                                 command = forced_command;
 422                                 debug("Forced command '%.500s'", forced_command);
 423                         }
 424                         if (have_pty)
 425                                 do_exec_pty(s, command, pw);
 426                         else
 427                                 do_exec_no_pty(s, command, pw);
 428
 429                         if (command != NULL)
 430                                 xfree(command);
 431                         /* Cleanup user's local Xauthority file. */
 432                         if (xauthfile)
 433                                 xauthfile_cleanup_proc(NULL);
 434                         return;
 435
 436                 default:
 437                         /*
 438                          * Any unknown messages in this phase are ignored,
 439                          * and a failure message is returned.
 440                          */
 441                         log("Unknown packet type received after authentication: %d", type);
 442                 }
 443                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 444                 packet_send();
 445                 packet_write_wait();
 446
 447                 /* Enable compression now that we have replied if appropriate. */
 448                 if (enable_compression_after_reply) {
 449                         enable_compression_after_reply = 0;
 450                         packet_start_compression(compression_level);
 451                 }
 452         }
 453 }
 454
 455 /*
 456  * This is called to fork and execute a command when we have no tty.  This
 457  * will call do_child from the child, and server_loop from the parent after
 458  * setting up file descriptors and such.
 459  */
 460 void
 461 do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
 462 {
 463         int pid;
 464
 465 #ifdef USE_PIPES
 466         int pin[2], pout[2], perr[2];
 467         /* Allocate pipes for communicating with the program. */
 468         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 469                 packet_disconnect("Could not create pipes: %.100s",
 470                                   strerror(errno));
 471 #else /* USE_PIPES */
 472         int inout[2], err[2];
 473         /* Uses socket pairs to communicate with the program. */
 474         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 475             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 476                 packet_disconnect("Could not create socket pairs: %.100s",
 477                                   strerror(errno));
 478 #endif /* USE_PIPES */
 479         if (s == NULL)
 480                 fatal("do_exec_no_pty: no session");
 481
 482         session_proctitle(s);
 483
 484 #ifdef USE_PAM
 485         do_pam_setcred();
 486 #endif /* USE_PAM */
 487
 488         /* Fork the child. */
 489         if ((pid = fork()) == 0) {
 490                 /* Child.  Reinitialize the log since the pid has changed. */
 491                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 492
 493                 signal(SIGPIPE, SIG_DFL);
 494
 495                 /*
 496                  * Create a new session and process group since the 4.4BSD
 497                  * setlogin() affects the entire process group.
 498                  */
 499                 if (setsid() < 0)
 500                         error("setsid failed: %.100s", strerror(errno));
 501
 502 #ifdef USE_PIPES
 503                 /*
 504                  * Redirect stdin.  We close the parent side of the socket
 505                  * pair, and make the child side the standard input.
 506                  */
 507                 close(pin[1]);
 508                 if (dup2(pin[0], 0) < 0)
 509                         perror("dup2 stdin");
 510                 close(pin[0]);
 511
 512                 /* Redirect stdout. */
 513                 close(pout[0]);
 514                 if (dup2(pout[1], 1) < 0)
 515                         perror("dup2 stdout");
 516                 close(pout[1]);
 517
 518                 /* Redirect stderr. */
 519                 close(perr[0]);
 520                 if (dup2(perr[1], 2) < 0)
 521                         perror("dup2 stderr");
 522                 close(perr[1]);
 523 #else /* USE_PIPES */
 524                 /*
 525                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 526                  * use the same socket, as some programs (particularly rdist)
 527                  * seem to depend on it.
 528                  */
 529                 close(inout[1]);
 530                 close(err[1]);
 531                 if (dup2(inout[0], 0) < 0)      /* stdin */
 532                         perror("dup2 stdin");
 533                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 534                         perror("dup2 stdout");
 535                 if (dup2(err[0], 2) < 0)        /* stderr */
 536                         perror("dup2 stderr");
 537 #endif /* USE_PIPES */
 538
 539                 /* Do processing for the child (exec command etc). */
 540                 do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
 541                 /* NOTREACHED */
 542         }
 543 #ifdef HAVE_CYGWIN
 544         if (is_winnt)
 545                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 546 #endif
 547         if (pid < 0)
 548                 packet_disconnect("fork failed: %.100s", strerror(errno));
 549         s->pid = pid;
 550         /* Set interactive/non-interactive mode. */
 551         packet_set_interactive(s->display != NULL);
 552 #ifdef USE_PIPES
 553         /* We are the parent.  Close the child sides of the pipes. */
 554         close(pin[0]);
 555         close(pout[1]);
 556         close(perr[1]);
 557
 558         if (compat20) {
 559                 session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
 560         } else {
 561                 /* Enter the interactive session. */
 562                 server_loop(pid, pin[1], pout[0], perr[0]);
 563                 /* server_loop has closed pin[1], pout[1], and perr[1]. */
 564         }
 565 #else /* USE_PIPES */
 566         /* We are the parent.  Close the child sides of the socket pairs. */
 567         close(inout[0]);
 568         close(err[0]);
 569
 570         /*
 571          * Enter the interactive session.  Note: server_loop must be able to
 572          * handle the case that fdin and fdout are the same.
 573          */
 574         if (compat20) {
 575                 session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
 576         } else {
 577                 server_loop(pid, inout[1], inout[1], err[1]);
 578                 /* server_loop has closed inout[1] and err[1]. */
 579         }
 580 #endif /* USE_PIPES */
 581 }
 582
 583 /*
 584  * This is called to fork and execute a command when we have a tty.  This
 585  * will call do_child from the child, and server_loop from the parent after
 586  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 587  * lastlog, and other such operations.
 588  */
 589 void
 590 do_exec_pty(Session *s, const char *command, struct passwd * pw)
 591 {
 592         int fdout, ptyfd, ttyfd, ptymaster;
 593         pid_t pid;
 594
 595         if (s == NULL)
 596                 fatal("do_exec_pty: no session");
 597         ptyfd = s->ptyfd;
 598         ttyfd = s->ttyfd;
 599
 600 #ifdef USE_PAM
 601         do_pam_session(pw->pw_name, s->tty);
 602         do_pam_setcred();
 603 #endif /* USE_PAM */
 604
 605         /* Fork the child. */
 606         if ((pid = fork()) == 0) {
 607                 /* Child.  Reinitialize the log because the pid has changed. */
 608                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 609
 610                 signal(SIGPIPE, SIG_DFL);
 611
 612                 /* Close the master side of the pseudo tty. */
 613                 close(ptyfd);
 614
 615                 /* Make the pseudo tty our controlling tty. */
 616                 pty_make_controlling_tty(&ttyfd, s->tty);
 617
 618                 /* Redirect stdin from the pseudo tty. */
 619                 if (dup2(ttyfd, fileno(stdin)) < 0)
 620                         error("dup2 stdin failed: %.100s", strerror(errno));
 621
 622                 /* Redirect stdout to the pseudo tty. */
 623                 if (dup2(ttyfd, fileno(stdout)) < 0)
 624                         error("dup2 stdin failed: %.100s", strerror(errno));
 625
 626                 /* Redirect stderr to the pseudo tty. */
 627                 if (dup2(ttyfd, fileno(stderr)) < 0)
 628                         error("dup2 stdin failed: %.100s", strerror(errno));
 629
 630                 /* Close the extra descriptor for the pseudo tty. */
 631                 close(ttyfd);
 632
 633                 /* record login, etc. similar to login(1) */
 634                 if (!(options.use_login && command == NULL))
 635                         do_login(s, command);
 636
 637                 /* Do common processing for the child, such as execing the command. */
 638                 do_child(command, pw, s->term, s->display, s->auth_proto,
 639                     s->auth_data, s->tty);
 640                 /* NOTREACHED */
 641         }
 642 #ifdef HAVE_CYGWIN
 643         if (is_winnt)
 644                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 645 #endif
 646         if (pid < 0)
 647                 packet_disconnect("fork failed: %.100s", strerror(errno));
 648         s->pid = pid;
 649
 650         /* Parent.  Close the slave side of the pseudo tty. */
 651         close(ttyfd);
 652
 653         /*
 654          * Create another descriptor of the pty master side for use as the
 655          * standard input.  We could use the original descriptor, but this
 656          * simplifies code in server_loop.  The descriptor is bidirectional.
 657          */
 658         fdout = dup(ptyfd);
 659         if (fdout < 0)
 660                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 661
 662         /* we keep a reference to the pty master */
 663         ptymaster = dup(ptyfd);
 664         if (ptymaster < 0)
 665                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 666         s->ptymaster = ptymaster;
 667
 668         /* Enter interactive session. */
 669         packet_set_interactive(1);
 670         if (compat20) {
 671                 session_set_fds(s, ptyfd, fdout, -1);
 672         } else {
 673                 server_loop(pid, ptyfd, fdout, -1);
 674                 /* server_loop _has_ closed ptyfd and fdout. */
 675                 session_pty_cleanup(s);
 676         }
 677 }
 678
 679 const char *
 680 get_remote_name_or_ip(void)
 681 {
 682         static const char *remote = "";
 683         if (utmp_len > 0)
 684                 remote = get_canonical_hostname(options.reverse_mapping_check);
 685         if (utmp_len == 0 || strlen(remote) > utmp_len)
 686                 remote = get_remote_ipaddr();
 687         return remote;
 688 }
 689
 690 /* administrative, login(1)-like work */
 691 void
 692 do_login(Session *s, const char *command)
 693 {
 694         FILE *f;
 695         char *time_string;
 696         char buf[256];
 697         char hostname[MAXHOSTNAMELEN];
 698         socklen_t fromlen;
 699         struct sockaddr_storage from;
 700         struct stat st;
 701         time_t last_login_time;
 702         struct passwd * pw = s->pw;
 703         pid_t pid = getpid();
 704
 705         /*
 706          * Get IP address of client. If the connection is not a socket, let
 707          * the address be 0.0.0.0.
 708          */
 709         memset(&from, 0, sizeof(from));
 710         if (packet_connection_is_on_socket()) {
 711                 fromlen = sizeof(from);
 712                 if (getpeername(packet_get_connection_in(),
 713                      (struct sockaddr *) & from, &fromlen) < 0) {
 714                         debug("getpeername: %.100s", strerror(errno));
 715                         fatal_cleanup();
 716                 }
 717         }
 718
 719         /* Get the time and hostname when the user last logged in. */
 720         hostname[0] = '\0';
 721         last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 722             hostname, sizeof(hostname));
 723
 724         /* Record that there was a login on that tty from the remote host. */
 725         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 726             get_remote_name_or_ip(), (struct sockaddr *)&from);
 727
 728 #ifdef USE_PAM
 729         /*
 730          * If password change is needed, do it now.
 731          * This needs to occur before the ~/.hushlogin check.
 732          */
 733         if (is_pam_password_change_required()) {
 734                 print_pam_messages();
 735                 do_pam_chauthtok();
 736         }
 737 #endif
 738
 739         /* Done if .hushlogin exists or a command given. */
 740         if (command != NULL)
 741                 return;
 742         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 743 #ifdef HAVE_LOGIN_CAP
 744         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 745 #else
 746         if (stat(buf, &st) >= 0)
 747 #endif
 748                 return;
 749
 750 #ifdef USE_PAM
 751         if (!is_pam_password_change_required())
 752                 print_pam_messages();
 753 #endif /* USE_PAM */
 754 #ifdef WITH_AIXAUTHENTICATE
 755         if (aixloginmsg && *aixloginmsg)
 756                 printf("%s\n", aixloginmsg);
 757 #endif /* WITH_AIXAUTHENTICATE */
 758
 759         if (last_login_time != 0) {
 760                 time_string = ctime(&last_login_time);
 761                 if (strchr(time_string, '\n'))
 762                         *strchr(time_string, '\n') = 0;
 763                 if (strcmp(hostname, "") == 0)
 764                         printf("Last login: %s\r\n", time_string);
 765                 else
 766                         printf("Last login: %s from %s\r\n", time_string, hostname);
 767         }
 768         if (options.print_motd) {
 769 #ifdef HAVE_LOGIN_CAP
 770                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 771                     "/etc/motd"), "r");
 772 #else
 773                 f = fopen("/etc/motd", "r");
 774 #endif
 775                 if (f) {
 776                         while (fgets(buf, sizeof(buf), f))
 777                                 fputs(buf, stdout);
 778                         fclose(f);
 779                 }
 780         }
 781 }
 782
 783 /*
 784  * Sets the value of the given variable in the environment.  If the variable
 785  * already exists, its value is overriden.
 786  */
 787 void
 788 child_set_env(char ***envp, u_int *envsizep, const char *name,
 789               const char *value)
 790 {
 791         u_int i, namelen;
 792         char **env;
 793
 794         /*
 795          * Find the slot where the value should be stored.  If the variable
 796          * already exists, we reuse the slot; otherwise we append a new slot
 797          * at the end of the array, expanding if necessary.
 798          */
 799         env = *envp;
 800         namelen = strlen(name);
 801         for (i = 0; env[i]; i++)
 802                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 803                         break;
 804         if (env[i]) {
 805                 /* Reuse the slot. */
 806                 xfree(env[i]);
 807         } else {
 808                 /* New variable.  Expand if necessary. */
 809                 if (i >= (*envsizep) - 1) {
 810                         (*envsizep) += 50;
 811                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 812                 }
 813                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 814                 env[i + 1] = NULL;
 815         }
 816
 817         /* Allocate space and format the variable in the appropriate slot. */
 818         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 819         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 820 }
 821
 822 /*
 823  * Reads environment variables from the given file and adds/overrides them
 824  * into the environment.  If the file does not exist, this does nothing.
 825  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 826  * and assignments of the form name=value.  No other forms are allowed.
 827  */
 828 void
 829 read_environment_file(char ***env, u_int *envsize,
 830                       const char *filename)
 831 {
 832         FILE *f;
 833         char buf[4096];
 834         char *cp, *value;
 835
 836         f = fopen(filename, "r");
 837         if (!f)
 838                 return;
 839
 840         while (fgets(buf, sizeof(buf), f)) {
 841                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 842                         ;
 843                 if (!*cp || *cp == '#' || *cp == '\n')
 844                         continue;
 845                 if (strchr(cp, '\n'))
 846                         *strchr(cp, '\n') = '\0';
 847                 value = strchr(cp, '=');
 848                 if (value == NULL) {
 849                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 850                         continue;
 851                 }
 852                 /*
 853                  * Replace the equals sign by nul, and advance value to
 854                  * the value string.
 855                  */
 856                 *value = '\0';
 857                 value++;
 858                 child_set_env(env, envsize, cp, value);
 859         }
 860         fclose(f);
 861 }
 862
 863 #ifdef USE_PAM
 864 /*
 865  * Sets any environment variables which have been specified by PAM
 866  */
 867 void do_pam_environment(char ***env, int *envsize)
 868 {
 869         char *equals, var_name[512], var_val[512];
 870         char **pam_env;
 871         int i;
 872
 873         if ((pam_env = fetch_pam_environment()) == NULL)
 874                 return;
 875
 876         for(i = 0; pam_env[i] != NULL; i++) {
 877                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 878                         continue;
 879
 880                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 881                         memset(var_name, '\0', sizeof(var_name));
 882                         memset(var_val, '\0', sizeof(var_val));
 883
 884                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 885                         strcpy(var_val, equals + 1);
 886
 887                         debug3("PAM environment: %s=%s", var_name, var_val);
 888
 889                         child_set_env(env, envsize, var_name, var_val);
 890                 }
 891         }
 892 }
 893 #endif /* USE_PAM */
 894
 895 #ifdef HAVE_CYGWIN
 896 void copy_environment(char ***env, int *envsize)
 897 {
 898         char *equals, var_name[512], var_val[512];
 899         int i;
 900
 901         for(i = 0; environ[i] != NULL; i++) {
 902                 if ((equals = strstr(environ[i], "=")) == NULL)
 903                         continue;
 904
 905                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 906                         memset(var_name, '\0', sizeof(var_name));
 907                         memset(var_val, '\0', sizeof(var_val));
 908
 909                         strncpy(var_name, environ[i], equals - environ[i]);
 910                         strcpy(var_val, equals + 1);
 911
 912                         debug3("Copy environment: %s=%s", var_name, var_val);
 913
 914                         child_set_env(env, envsize, var_name, var_val);
 915                 }
 916         }
 917 }
 918 #endif
 919
 920 #if defined(HAVE_GETUSERATTR)
 921 /*
 922  * AIX-specific login initialisation
 923  */
 924 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 925 {
 926         struct rlimit rlim;
 927         int slim, hlim;
 928
 929         getrlimit(resource, &rlim);
 930
 931         slim = 0;
 932         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 933                 if (slim < 0) {
 934                         rlim.rlim_cur = RLIM_INFINITY;
 935                 } else if (slim != 0) {
 936                         /* See the wackiness below */
 937                         if (rlim.rlim_cur == slim * mult)
 938                                 slim = 0;
 939                         else
 940                                 rlim.rlim_cur = slim * mult;
 941                 }
 942         }
 943
 944         hlim = 0;
 945         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 946                 if (hlim < 0) {
 947                         rlim.rlim_max = RLIM_INFINITY;
 948                 } else if (hlim != 0) {
 949                         rlim.rlim_max = hlim * mult;
 950                 }
 951         }
 952
 953         /*
 954          * XXX For cpu and fsize the soft limit is set to the hard limit
 955          * if the hard limit is left at its default value and the soft limit
 956          * is changed from its default value, either by requesting it
 957          * (slim == 0) or by setting it to the current default.  At least
 958          * that's how rlogind does it.  If you're confused you're not alone.
 959          * Bug or feature? AIX 4.3.1.2
 960          */
 961         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 962             && hlim == 0 && slim != 0)
 963                 rlim.rlim_max = rlim.rlim_cur;
 964         /* A specified hard limit limits the soft limit */
 965         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 966                 rlim.rlim_cur = rlim.rlim_max;
 967         /* A soft limit can increase a hard limit */
 968         else if (rlim.rlim_cur > rlim.rlim_max)
 969                 rlim.rlim_max = rlim.rlim_cur;
 970
 971         if (setrlimit(resource, &rlim) != 0)
 972                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 973 }
 974
 975 void set_limits_from_userattr(char *user)
 976 {
 977         int mask;
 978         char buf[16];
 979
 980         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 981         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 982         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 983         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 984         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 985         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 986 #if defined(S_UNOFILE)
 987         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
 988 #endif
 989
 990         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
 991                 /* Convert decimal to octal */
 992                 (void) snprintf(buf, sizeof(buf), "%d", mask);
 993                 if (sscanf(buf, "%o", &mask) == 1)
 994                         umask(mask);
 995         }
 996 }
 997 #endif /* defined(HAVE_GETUSERATTR) */
 998
 999 /*
1000  * Performs common processing for the child, such as setting up the
1001  * environment, closing extra file descriptors, setting the user and group
1002  * ids, and executing the command or shell.
1003  */
1004 void
1005 do_child(const char *command, struct passwd * pw, const char *term,
1006          const char *display, const char *auth_proto,
1007          const char *auth_data, const char *ttyname)
1008 {
1009         const char *shell, *hostname = NULL, *cp = NULL;
1010         char buf[256];
1011         char cmd[1024];
1012         FILE *f = NULL;
1013         u_int envsize, i;
1014         char **env;
1015         extern char **environ;
1016         struct stat st;
1017         char *argv[10];
1018 #ifdef WITH_IRIX_PROJECT
1019         prid_t projid;
1020 #endif /* WITH_IRIX_PROJECT */
1021 #ifdef WITH_IRIX_JOBS
1022         jid_t jid = 0;
1023 #else
1024 #ifdef WITH_IRIX_ARRAY
1025         int jid = 0;
1026 #endif /* WITH_IRIX_ARRAY */
1027 #endif /* WITH_IRIX_JOBS */
1028
1029
1030         /* login(1) is only called if we execute the login shell */
1031         if (options.use_login && command != NULL)
1032                 options.use_login = 0;
1033
1034 #ifndef USE_PAM /* pam_nologin handles this */
1035         if (!options.use_login) {
1036 # ifdef HAVE_LOGIN_CAP
1037                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1038                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1039                             _PATH_NOLOGIN), "r");
1040 # else /* HAVE_LOGIN_CAP */
1041                 if (pw->pw_uid)
1042                         f = fopen(_PATH_NOLOGIN, "r");
1043 # endif /* HAVE_LOGIN_CAP */
1044                 if (f) {
1045                         /* /etc/nologin exists.  Print its contents and exit. */
1046                         while (fgets(buf, sizeof(buf), f))
1047                                 fputs(buf, stderr);
1048                         fclose(f);
1049                         exit(254);
1050                 }
1051         }
1052 #endif /* USE_PAM */
1053
1054         /* Set login name, uid, gid, and groups. */
1055         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1056            switch, so we let login(1) to this for us. */
1057         if (!options.use_login) {
1058 #ifdef HAVE_OSF_SIA
1059                 session_setup_sia(pw->pw_name, ttyname);
1060 #else /* HAVE_OSF_SIA */
1061 #ifdef HAVE_CYGWIN
1062                 if (is_winnt) {
1063 #else
1064                 if (getuid() == 0 || geteuid() == 0) {
1065 #endif
1066 # ifdef HAVE_GETUSERATTR
1067                         set_limits_from_userattr(pw->pw_name);
1068 # endif /* HAVE_GETUSERATTR */
1069 # ifdef HAVE_LOGIN_CAP
1070                         if (setusercontext(lc, pw, pw->pw_uid,
1071                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1072                                 perror("unable to set user context");
1073                                 exit(1);
1074                         }
1075 #ifdef BSD_AUTH
1076                         if (auth_approval(NULL, lc, pw->pw_name, "ssh") <= 0) {
1077                                 error("approval failure for %s", pw->pw_name);
1078                                 fprintf(stderr, "Approval failure");
1079                                 exit(1);
1080                         }
1081 #endif
1082 # else /* HAVE_LOGIN_CAP */
1083 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1084                         /* Sets login uid for accounting */
1085                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1086                                 error("setluid: %s", strerror(errno));
1087 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1088
1089                         if (setlogin(pw->pw_name) < 0)
1090                                 error("setlogin failed: %s", strerror(errno));
1091                         if (setgid(pw->pw_gid) < 0) {
1092                                 perror("setgid");
1093                                 exit(1);
1094                         }
1095                         /* Initialize the group list. */
1096                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1097                                 perror("initgroups");
1098                                 exit(1);
1099                         }
1100                         endgrent();
1101 #  ifdef WITH_IRIX_JOBS
1102                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1103                         if (jid == -1) {
1104                                 fatal("Failed to create job container: %.100s",
1105                                       strerror(errno));
1106                         }
1107 #  endif /* WITH_IRIX_JOBS */
1108 #  ifdef WITH_IRIX_ARRAY
1109                         /* initialize array session */
1110                         if (jid == 0) {
1111                                 if (newarraysess() != 0)
1112                                         fatal("Failed to set up new array session: %.100s",
1113                                               strerror(errno));
1114                         }
1115 #  endif /* WITH_IRIX_ARRAY */
1116 #  ifdef WITH_IRIX_PROJECT
1117                         /* initialize irix project info */
1118                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1119                           debug("Failed to get project id, using projid 0");
1120                           projid = 0;
1121                         }
1122                         if (setprid(projid))
1123                           fatal("Failed to initialize project %d for %s: %.100s",
1124                                 (int)projid, pw->pw_name, strerror(errno));
1125 #  endif /* WITH_IRIX_PROJECT */
1126 #ifdef WITH_IRIX_AUDIT
1127                         if (sysconf(_SC_AUDIT)) {
1128                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1129                                 if (satsetid(pw->pw_uid))
1130                                         debug("error setting satid: %.100s", strerror(errno));
1131                         }
1132 #endif /* WITH_IRIX_AUDIT */
1133
1134                         /* Permanently switch to the desired uid. */
1135                         permanently_set_uid(pw->pw_uid);
1136 # endif /* HAVE_LOGIN_CAP */
1137                 }
1138 #endif /* HAVE_OSF_SIA */
1139
1140 #ifdef HAVE_CYGWIN
1141                 if (is_winnt)
1142 #endif
1143                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1144                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1145         }
1146         /*
1147          * Get the shell from the password data.  An empty shell field is
1148          * legal, and means /bin/sh.
1149          */
1150         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1151 #ifdef HAVE_LOGIN_CAP
1152         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1153 #endif
1154
1155 #ifdef AFS
1156         /* Try to get AFS tokens for the local cell. */
1157         if (k_hasafs()) {
1158                 char cell[64];
1159
1160                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1161                         krb_afslog(cell, 0);
1162
1163                 krb_afslog(0, 0);
1164         }
1165 #endif /* AFS */
1166
1167         /* Initialize the environment. */
1168         envsize = 100;
1169         env = xmalloc(envsize * sizeof(char *));
1170         env[0] = NULL;
1171
1172 #ifdef HAVE_CYGWIN
1173         /*
1174          * The Windows environment contains some setting which are
1175          * important for a running system. They must not be dropped.
1176          */
1177         copy_environment(&env, &envsize);
1178 #endif
1179
1180         if (!options.use_login) {
1181                 /* Set basic environment. */
1182                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1183                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1184                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1185 #ifdef HAVE_LOGIN_CAP
1186                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1187                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1188 #else /* HAVE_LOGIN_CAP */
1189 # ifndef HAVE_CYGWIN
1190                 /*
1191                  * There's no standard path on Windows. The path contains
1192                  * important components pointing to the system directories,
1193                  * needed for loading shared libraries. So the path better
1194                  * remains intact here.
1195                  */
1196                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1197 # endif /* HAVE_CYGWIN */
1198 #endif /* HAVE_LOGIN_CAP */
1199
1200                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1201                          _PATH_MAILDIR, pw->pw_name);
1202                 child_set_env(&env, &envsize, "MAIL", buf);
1203
1204                 /* Normal systems set SHELL by default. */
1205                 child_set_env(&env, &envsize, "SHELL", shell);
1206         }
1207         if (getenv("TZ"))
1208                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1209
1210         /* Set custom environment options from RSA authentication. */
1211         while (custom_environment) {
1212                 struct envstring *ce = custom_environment;
1213                 char *s = ce->s;
1214                 int i;
1215                 for (i = 0; s[i] != '=' && s[i]; i++);
1216                 if (s[i] == '=') {
1217                         s[i] = 0;
1218                         child_set_env(&env, &envsize, s, s + i + 1);
1219                 }
1220                 custom_environment = ce->next;
1221                 xfree(ce->s);
1222                 xfree(ce);
1223         }
1224
1225         snprintf(buf, sizeof buf, "%.50s %d %d",
1226                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1227         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1228
1229         if (ttyname)
1230                 child_set_env(&env, &envsize, "SSH_TTY", ttyname);
1231         if (term)
1232                 child_set_env(&env, &envsize, "TERM", term);
1233         if (display)
1234                 child_set_env(&env, &envsize, "DISPLAY", display);
1235         if (original_command)
1236                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1237                     original_command);
1238
1239 #ifdef _AIX
1240         if ((cp = getenv("AUTHSTATE")) != NULL)
1241                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1242         if ((cp = getenv("KRB5CCNAME")) != NULL)
1243                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1244         read_environment_file(&env, &envsize, "/etc/environment");
1245 #endif
1246
1247 #ifdef KRB4
1248         {
1249                 extern char *ticket;
1250
1251                 if (ticket)
1252                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1253         }
1254 #endif /* KRB4 */
1255
1256 #ifdef USE_PAM
1257         /* Pull in any environment variables that may have been set by PAM. */
1258         do_pam_environment(&env, &envsize);
1259 #endif /* USE_PAM */
1260
1261         if (xauthfile)
1262                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1263         if (auth_get_socket_name() != NULL)
1264                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1265                               auth_get_socket_name());
1266
1267         /* read $HOME/.ssh/environment. */
1268         if (!options.use_login) {
1269                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1270                     pw->pw_dir);
1271                 read_environment_file(&env, &envsize, buf);
1272         }
1273         if (debug_flag) {
1274                 /* dump the environment */
1275                 fprintf(stderr, "Environment:\n");
1276                 for (i = 0; env[i]; i++)
1277                         fprintf(stderr, "  %.200s\n", env[i]);
1278         }
1279         /* we have to stash the hostname before we close our socket. */
1280         if (options.use_login)
1281                 hostname = get_remote_name_or_ip();
1282         /*
1283          * Close the connection descriptors; note that this is the child, and
1284          * the server will still have the socket open, and it is important
1285          * that we do not shutdown it.  Note that the descriptors cannot be
1286          * closed before building the environment, as we call
1287          * get_remote_ipaddr there.
1288          */
1289         if (packet_get_connection_in() == packet_get_connection_out())
1290                 close(packet_get_connection_in());
1291         else {
1292                 close(packet_get_connection_in());
1293                 close(packet_get_connection_out());
1294         }
1295         /*
1296          * Close all descriptors related to channels.  They will still remain
1297          * open in the parent.
1298          */
1299         /* XXX better use close-on-exec? -markus */
1300         channel_close_all();
1301
1302         /*
1303          * Close any extra file descriptors.  Note that there may still be
1304          * descriptors left by system functions.  They will be closed later.
1305          */
1306         endpwent();
1307
1308         /*
1309          * Close any extra open file descriptors so that we don\'t have them
1310          * hanging around in clients.  Note that we want to do this after
1311          * initgroups, because at least on Solaris 2.3 it leaves file
1312          * descriptors open.
1313          */
1314         for (i = 3; i < 64; i++)
1315                 close(i);
1316
1317         /* Change current directory to the user\'s home directory. */
1318         if (chdir(pw->pw_dir) < 0) {
1319                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1320                         pw->pw_dir, strerror(errno));
1321 #ifdef HAVE_LOGIN_CAP
1322                 if (login_getcapbool(lc, "requirehome", 0))
1323                         exit(1);
1324 #endif
1325         }
1326
1327         /*
1328          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1329          * xauth are run in the proper environment.
1330          */
1331         environ = env;
1332
1333         /*
1334          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1335          * in this order).
1336          */
1337         if (!options.use_login) {
1338                 if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1339                         if (debug_flag)
1340                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_USER_RC);
1341
1342                         f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1343                         if (f) {
1344                                 if (auth_proto != NULL && auth_data != NULL)
1345                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1346                                 pclose(f);
1347                         } else
1348                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_USER_RC);
1349                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1350                         if (debug_flag)
1351                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_SYSTEM_RC);
1352
1353                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1354                         if (f) {
1355                                 if (auth_proto != NULL && auth_data != NULL)
1356                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1357                                 pclose(f);
1358                         } else
1359                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_SYSTEM_RC);
1360                 } else if (options.xauth_location != NULL) {
1361                         /* Add authority data to .Xauthority if appropriate. */
1362                         if (auth_proto != NULL && auth_data != NULL) {
1363                                 char *screen = strchr(display, ':');
1364                                 if (debug_flag) {
1365                                         fprintf(stderr,
1366                                             "Running %.100s add %.100s %.100s %.100s\n",
1367                                             options.xauth_location, display,
1368                                             auth_proto, auth_data);
1369 #ifndef NO_X11_UNIX_SOCKETS
1370                                         if (screen != NULL)
1371                                                 fprintf(stderr,
1372                                                     "Adding %.*s/unix%s %s %s\n",
1373                                                     (int)(screen-display), display,
1374                                                     screen, auth_proto, auth_data);
1375 #endif /* NO_X11_UNIX_SOCKETS */
1376                                 }
1377                                 snprintf(cmd, sizeof cmd, "%s -q -",
1378                                     options.xauth_location);
1379                                 f = popen(cmd, "w");
1380                                 if (f) {
1381                                         fprintf(f, "add %s %s %s\n", display,
1382                                             auth_proto, auth_data);
1383 #ifndef NO_X11_UNIX_SOCKETS
1384                                         if (screen != NULL)
1385                                                 fprintf(f, "add %.*s/unix%s %s %s\n",
1386                                                     (int)(screen-display), display,
1387                                                     screen, auth_proto, auth_data);
1388 #endif /* NO_X11_UNIX_SOCKETS */
1389                                         pclose(f);
1390                                 } else {
1391                                         fprintf(stderr, "Could not run %s\n",
1392                                             cmd);
1393                                 }
1394                         }
1395                 }
1396                 /* Get the last component of the shell name. */
1397                 cp = strrchr(shell, '/');
1398                 if (cp)
1399                         cp++;
1400                 else
1401                         cp = shell;
1402         }
1403         /*
1404          * If we have no command, execute the shell.  In this case, the shell
1405          * name to be passed in argv[0] is preceded by '-' to indicate that
1406          * this is a login shell.
1407          */
1408         if (!command) {
1409                 if (!options.use_login) {
1410                         char buf[256];
1411
1412                         /*
1413                          * Check for mail if we have a tty and it was enabled
1414                          * in server options.
1415                          */
1416                         if (ttyname && options.check_mail) {
1417                                 char *mailbox;
1418                                 struct stat mailstat;
1419                                 mailbox = getenv("MAIL");
1420                                 if (mailbox != NULL) {
1421                                         if (stat(mailbox, &mailstat) != 0 ||
1422                                             mailstat.st_size == 0)
1423                                                 printf("No mail.\n");
1424                                         else if (mailstat.st_mtime < mailstat.st_atime)
1425                                                 printf("You have mail.\n");
1426                                         else
1427                                                 printf("You have new mail.\n");
1428                                 }
1429                         }
1430                         /* Start the shell.  Set initial character to '-'. */
1431                         buf[0] = '-';
1432                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1433                         buf[sizeof(buf) - 1] = 0;
1434
1435                         /* Execute the shell. */
1436                         argv[0] = buf;
1437                         argv[1] = NULL;
1438                         execve(shell, argv, env);
1439
1440                         /* Executing the shell failed. */
1441                         perror(shell);
1442                         exit(1);
1443
1444                 } else {
1445                         /* Launch login(1). */
1446
1447                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1448                              "-p", "-f", "--", pw->pw_name, NULL);
1449
1450                         /* Login couldn't be executed, die. */
1451
1452                         perror("login");
1453                         exit(1);
1454                 }
1455         }
1456         /*
1457          * Execute the command using the user's shell.  This uses the -c
1458          * option to execute the command.
1459          */
1460         argv[0] = (char *) cp;
1461         argv[1] = "-c";
1462         argv[2] = (char *) command;
1463         argv[3] = NULL;
1464         execve(shell, argv, env);
1465         perror(shell);
1466         exit(1);
1467 }
1468
1469 Session *
1470 session_new(void)
1471 {
1472         int i;
1473         static int did_init = 0;
1474         if (!did_init) {
1475                 debug("session_new: init");
1476                 for(i = 0; i < MAX_SESSIONS; i++) {
1477                         sessions[i].used = 0;
1478                         sessions[i].self = i;
1479                 }
1480                 did_init = 1;
1481         }
1482         for(i = 0; i < MAX_SESSIONS; i++) {
1483                 Session *s = &sessions[i];
1484                 if (! s->used) {
1485                         s->pid = 0;
1486                         s->extended = 0;
1487                         s->chanid = -1;
1488                         s->ptyfd = -1;
1489                         s->ttyfd = -1;
1490                         s->term = NULL;
1491                         s->pw = NULL;
1492                         s->display = NULL;
1493                         s->screen = 0;
1494                         s->auth_data = NULL;
1495                         s->auth_proto = NULL;
1496                         s->used = 1;
1497                         s->pw = NULL;
1498                         debug("session_new: session %d", i);
1499                         return s;
1500                 }
1501         }
1502         return NULL;
1503 }
1504
1505 void
1506 session_dump(void)
1507 {
1508         int i;
1509         for(i = 0; i < MAX_SESSIONS; i++) {
1510                 Session *s = &sessions[i];
1511                 debug("dump: used %d session %d %p channel %d pid %d",
1512                     s->used,
1513                     s->self,
1514                     s,
1515                     s->chanid,
1516                     s->pid);
1517         }
1518 }
1519
1520 int
1521 session_open(int chanid)
1522 {
1523         Session *s = session_new();
1524         debug("session_open: channel %d", chanid);
1525         if (s == NULL) {
1526                 error("no more sessions");
1527                 return 0;
1528         }
1529         s->pw = auth_get_user();
1530         if (s->pw == NULL)
1531                 fatal("no user for session %d", s->self);
1532         debug("session_open: session %d: link with channel %d", s->self, chanid);
1533         s->chanid = chanid;
1534         return 1;
1535 }
1536
1537 Session *
1538 session_by_channel(int id)
1539 {
1540         int i;
1541         for(i = 0; i < MAX_SESSIONS; i++) {
1542                 Session *s = &sessions[i];
1543                 if (s->used && s->chanid == id) {
1544                         debug("session_by_channel: session %d channel %d", i, id);
1545                         return s;
1546                 }
1547         }
1548         debug("session_by_channel: unknown channel %d", id);
1549         session_dump();
1550         return NULL;
1551 }
1552
1553 Session *
1554 session_by_pid(pid_t pid)
1555 {
1556         int i;
1557         debug("session_by_pid: pid %d", pid);
1558         for(i = 0; i < MAX_SESSIONS; i++) {
1559                 Session *s = &sessions[i];
1560                 if (s->used && s->pid == pid)
1561                         return s;
1562         }
1563         error("session_by_pid: unknown pid %d", pid);
1564         session_dump();
1565         return NULL;
1566 }
1567
1568 int
1569 session_window_change_req(Session *s)
1570 {
1571         s->col = packet_get_int();
1572         s->row = packet_get_int();
1573         s->xpixel = packet_get_int();
1574         s->ypixel = packet_get_int();
1575         packet_done();
1576         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1577         return 1;
1578 }
1579
1580 int
1581 session_pty_req(Session *s)
1582 {
1583         u_int len;
1584         char *term_modes;       /* encoded terminal modes */
1585
1586         if (no_pty_flag)
1587                 return 0;
1588         if (s->ttyfd != -1)
1589                 return 0;
1590         s->term = packet_get_string(&len);
1591         s->col = packet_get_int();
1592         s->row = packet_get_int();
1593         s->xpixel = packet_get_int();
1594         s->ypixel = packet_get_int();
1595         term_modes = packet_get_string(&len);
1596         packet_done();
1597
1598         if (strcmp(s->term, "") == 0) {
1599                 xfree(s->term);
1600                 s->term = NULL;
1601         }
1602         /* Allocate a pty and open it. */
1603         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1604                 xfree(s->term);
1605                 s->term = NULL;
1606                 s->ptyfd = -1;
1607                 s->ttyfd = -1;
1608                 error("session_pty_req: session %d alloc failed", s->self);
1609                 xfree(term_modes);
1610                 return 0;
1611         }
1612         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1613         /*
1614          * Add a cleanup function to clear the utmp entry and record logout
1615          * time in case we call fatal() (e.g., the connection gets closed).
1616          */
1617         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1618         pty_setowner(s->pw, s->tty);
1619         /* Get window size from the packet. */
1620         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1621
1622         session_proctitle(s);
1623
1624         /* XXX parse and set terminal modes */
1625         xfree(term_modes);
1626         return 1;
1627 }
1628
1629 int
1630 session_subsystem_req(Session *s)
1631 {
1632         u_int len;
1633         int success = 0;
1634         char *subsys = packet_get_string(&len);
1635         int i;
1636
1637         packet_done();
1638         log("subsystem request for %s", subsys);
1639
1640         for (i = 0; i < options.num_subsystems; i++) {
1641                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1642                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1643                         do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1644                         success = 1;
1645                 }
1646         }
1647
1648         if (!success)
1649                 log("subsystem request for %s failed, subsystem not found", subsys);
1650
1651         xfree(subsys);
1652         return success;
1653 }
1654
1655 int
1656 session_x11_req(Session *s)
1657 {
1658         int fd;
1659         if (no_x11_forwarding_flag) {
1660                 debug("X11 forwarding disabled in user configuration file.");
1661                 return 0;
1662         }
1663         if (!options.x11_forwarding) {
1664                 debug("X11 forwarding disabled in server configuration file.");
1665                 return 0;
1666         }
1667         if (xauthfile != NULL) {
1668                 debug("X11 fwd already started.");
1669                 return 0;
1670         }
1671
1672         debug("Received request for X11 forwarding with auth spoofing.");
1673         if (s->display != NULL)
1674                 packet_disconnect("Protocol error: X11 display already set.");
1675
1676         s->single_connection = packet_get_char();
1677         s->auth_proto = packet_get_string(NULL);
1678         s->auth_data = packet_get_string(NULL);
1679         s->screen = packet_get_int();
1680         packet_done();
1681
1682         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1683         if (s->display == NULL) {
1684                 xfree(s->auth_proto);
1685                 xfree(s->auth_data);
1686                 return 0;
1687         }
1688         xauthfile = xmalloc(MAXPATHLEN);
1689         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1690         temporarily_use_uid(s->pw->pw_uid);
1691         if (mkdtemp(xauthfile) == NULL) {
1692                 restore_uid();
1693                 error("private X11 dir: mkdtemp %s failed: %s",
1694                     xauthfile, strerror(errno));
1695                 xfree(xauthfile);
1696                 xauthfile = NULL;
1697                 xfree(s->auth_proto);
1698                 xfree(s->auth_data);
1699                 /* XXXX remove listening channels */
1700                 return 0;
1701         }
1702         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1703         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1704         if (fd >= 0)
1705                 close(fd);
1706         restore_uid();
1707         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1708         return 1;
1709 }
1710
1711 int
1712 session_shell_req(Session *s)
1713 {
1714         /* if forced_command == NULL, the shell is execed */
1715         char *shell = forced_command;
1716         packet_done();
1717         s->extended = 1;
1718         if (s->ttyfd == -1)
1719                 do_exec_no_pty(s, shell, s->pw);
1720         else
1721                 do_exec_pty(s, shell, s->pw);
1722         return 1;
1723 }
1724
1725 int
1726 session_exec_req(Session *s)
1727 {
1728         u_int len;
1729         char *command = packet_get_string(&len);
1730         packet_done();
1731         if (forced_command) {
1732                 original_command = command;
1733                 command = forced_command;
1734                 debug("Forced command '%.500s'", forced_command);
1735         }
1736         s->extended = 1;
1737         if (s->ttyfd == -1)
1738                 do_exec_no_pty(s, command, s->pw);
1739         else
1740                 do_exec_pty(s, command, s->pw);
1741         if (forced_command == NULL)
1742                 xfree(command);
1743         return 1;
1744 }
1745
1746 int
1747 session_auth_agent_req(Session *s)
1748 {
1749         static int called = 0;
1750         packet_done();
1751         if (no_agent_forwarding_flag) {
1752                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1753                 return 0;
1754         }
1755         if (called) {
1756                 return 0;
1757         } else {
1758                 called = 1;
1759                 return auth_input_request_forwarding(s->pw);
1760         }
1761 }
1762
1763 void
1764 session_input_channel_req(int id, void *arg)
1765 {
1766         u_int len;
1767         int reply;
1768         int success = 0;
1769         char *rtype;
1770         Session *s;
1771         Channel *c;
1772
1773         rtype = packet_get_string(&len);
1774         reply = packet_get_char();
1775
1776         s = session_by_channel(id);
1777         if (s == NULL)
1778                 fatal("session_input_channel_req: channel %d: no session", id);
1779         c = channel_lookup(id);
1780         if (c == NULL)
1781                 fatal("session_input_channel_req: channel %d: bad channel", id);
1782
1783         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1784             s->self, id, rtype, reply);
1785
1786         /*
1787          * a session is in LARVAL state until a shell
1788          * or programm is executed
1789          */
1790         if (c->type == SSH_CHANNEL_LARVAL) {
1791                 if (strcmp(rtype, "shell") == 0) {
1792                         success = session_shell_req(s);
1793                 } else if (strcmp(rtype, "exec") == 0) {
1794                         success = session_exec_req(s);
1795                 } else if (strcmp(rtype, "pty-req") == 0) {
1796                         success =  session_pty_req(s);
1797                 } else if (strcmp(rtype, "x11-req") == 0) {
1798                         success = session_x11_req(s);
1799                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1800                         success = session_auth_agent_req(s);
1801                 } else if (strcmp(rtype, "subsystem") == 0) {
1802                         success = session_subsystem_req(s);
1803                 }
1804         }
1805         if (strcmp(rtype, "window-change") == 0) {
1806                 success = session_window_change_req(s);
1807         }
1808
1809         if (reply) {
1810                 packet_start(success ?
1811                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1812                 packet_put_int(c->remote_id);
1813                 packet_send();
1814         }
1815         xfree(rtype);
1816 }
1817
1818 void
1819 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1820 {
1821         if (!compat20)
1822                 fatal("session_set_fds: called for proto != 2.0");
1823         /*
1824          * now that have a child and a pipe to the child,
1825          * we can activate our channel and register the fd's
1826          */
1827         if (s->chanid == -1)
1828                 fatal("no channel for session %d", s->self);
1829         channel_set_fds(s->chanid,
1830             fdout, fdin, fderr,
1831             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1832             1);
1833 }
1834
1835 void
1836 session_pty_cleanup(Session *s)
1837 {
1838         if (s == NULL || s->ttyfd == -1)
1839                 return;
1840
1841         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1842
1843         /* Cancel the cleanup function. */
1844         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1845
1846         /* Record that the user has logged out. */
1847         record_logout(s->pid, s->tty);
1848
1849         /* Release the pseudo-tty. */
1850         pty_release(s->tty);
1851
1852         /*
1853          * Close the server side of the socket pairs.  We must do this after
1854          * the pty cleanup, so that another process doesn't get this pty
1855          * while we're still cleaning up.
1856          */
1857         if (close(s->ptymaster) < 0)
1858                 error("close(s->ptymaster): %s", strerror(errno));
1859 }
1860
1861 void
1862 session_exit_message(Session *s, int status)
1863 {
1864         Channel *c;
1865         if (s == NULL)
1866                 fatal("session_close: no session");
1867         c = channel_lookup(s->chanid);
1868         if (c == NULL)
1869                 fatal("session_close: session %d: no channel %d",
1870                     s->self, s->chanid);
1871         debug("session_exit_message: session %d channel %d pid %d",
1872             s->self, s->chanid, s->pid);
1873
1874         if (WIFEXITED(status)) {
1875                 channel_request_start(s->chanid,
1876                     "exit-status", 0);
1877                 packet_put_int(WEXITSTATUS(status));
1878                 packet_send();
1879         } else if (WIFSIGNALED(status)) {
1880                 channel_request_start(s->chanid,
1881                     "exit-signal", 0);
1882                 packet_put_int(WTERMSIG(status));
1883 #ifdef WCOREDUMP
1884                 packet_put_char(WCOREDUMP(status));
1885 #else /* WCOREDUMP */
1886                 packet_put_char(0);
1887 #endif /* WCOREDUMP */
1888                 packet_put_cstring("");
1889                 packet_put_cstring("");
1890                 packet_send();
1891         } else {
1892                 /* Some weird exit cause.  Just exit. */
1893                 packet_disconnect("wait returned status %04x.", status);
1894         }
1895
1896         /* disconnect channel */
1897         debug("session_exit_message: release channel %d", s->chanid);
1898         channel_cancel_cleanup(s->chanid);
1899         /*
1900          * emulate a write failure with 'chan_write_failed', nobody will be
1901          * interested in data we write.
1902          * Note that we must not call 'chan_read_failed', since there could
1903          * be some more data waiting in the pipe.
1904          */
1905         if (c->ostate != CHAN_OUTPUT_CLOSED)
1906                 chan_write_failed(c);
1907         s->chanid = -1;
1908 }
1909
1910 void
1911 session_free(Session *s)
1912 {
1913         debug("session_free: session %d pid %d", s->self, s->pid);
1914         if (s->term)
1915                 xfree(s->term);
1916         if (s->display)
1917                 xfree(s->display);
1918         if (s->auth_data)
1919                 xfree(s->auth_data);
1920         if (s->auth_proto)
1921                 xfree(s->auth_proto);
1922         s->used = 0;
1923 }
1924
1925 void
1926 session_close(Session *s)
1927 {
1928         session_pty_cleanup(s);
1929         session_free(s);
1930         session_proctitle(s);
1931 }
1932
1933 void
1934 session_close_by_pid(pid_t pid, int status)
1935 {
1936         Session *s = session_by_pid(pid);
1937         if (s == NULL) {
1938                 debug("session_close_by_pid: no session for pid %d", s->pid);
1939                 return;
1940         }
1941         if (s->chanid != -1)
1942                 session_exit_message(s, status);
1943         session_close(s);
1944 }
1945
1946 /*
1947  * this is called when a channel dies before
1948  * the session 'child' itself dies
1949  */
1950 void
1951 session_close_by_channel(int id, void *arg)
1952 {
1953         Session *s = session_by_channel(id);
1954         if (s == NULL) {
1955                 debug("session_close_by_channel: no session for channel %d", id);
1956                 return;
1957         }
1958         /* disconnect channel */
1959         channel_cancel_cleanup(s->chanid);
1960         s->chanid = -1;
1961
1962         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1963         if (s->pid == 0) {
1964                 /* close session immediately */
1965                 session_close(s);
1966         } else {
1967                 /* notify child, delay session cleanup */
1968                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1969                         error("session_close_by_channel: kill %d: %s",
1970                             s->pid, strerror(errno));
1971         }
1972 }
1973
1974 char *
1975 session_tty_list(void)
1976 {
1977         static char buf[1024];
1978         int i;
1979         buf[0] = '\0';
1980         for(i = 0; i < MAX_SESSIONS; i++) {
1981                 Session *s = &sessions[i];
1982                 if (s->used && s->ttyfd != -1) {
1983                         if (buf[0] != '\0')
1984                                 strlcat(buf, ",", sizeof buf);
1985                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1986                 }
1987         }
1988         if (buf[0] == '\0')
1989                 strlcpy(buf, "notty", sizeof buf);
1990         return buf;
1991 }
1992
1993 void
1994 session_proctitle(Session *s)
1995 {
1996         if (s->pw == NULL)
1997                 error("no user for session %d", s->self);
1998         else
1999                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2000 }
2001
2002 void
2003 do_authenticated2(Authctxt *authctxt)
2004 {
2005         /*
2006          * Cancel the alarm we set to limit the time taken for
2007          * authentication.
2008          */
2009         alarm(0);
2010         if (startup_pipe != -1) {
2011                 close(startup_pipe);
2012                 startup_pipe = -1;
2013         }
2014 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
2015         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
2016                 error("unable to get login class");
2017                 return;
2018         }
2019 #endif
2020         server_loop2();
2021         if (xauthfile)
2022                 xauthfile_cleanup_proc(NULL);
2023 }