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