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 1.55 2001/02/08 19:30:52 itojun 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_OSF_SIA
  76 # include <sia.h>
  77 # include <siad.h>
  78 #endif
  79
  80 #ifdef HAVE_CYGWIN
  81 #include <windows.h>
  82 #include <sys/cygwin.h>
  83 #define is_winnt       (GetVersion() < 0x80000000)
  84 #endif
  85
  86 /* AIX limits */
  87 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  88 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  89 # define S_UCPU_HARD  S_UCPU "_hard"
  90 # define S_UDATA_HARD  S_UDATA "_hard"
  91 # define S_USTACK_HARD  S_USTACK "_hard"
  92 # define S_URSS_HARD  S_URSS "_hard"
  93 # define S_UCORE_HARD  S_UCORE "_hard"
  94 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  95 #endif
  96
  97 #ifdef HAVE_LOGIN_CAP
  98 #include <login_cap.h>
  99 #endif
 100
 101 /* types */
 102
 103 #define TTYSZ 64
 104 typedef struct Session Session;
 105 struct Session {
 106         int     used;
 107         int     self;
 108         int     extended;
 109         struct  passwd *pw;
 110         pid_t   pid;
 111         /* tty */
 112         char    *term;
 113         int     ptyfd, ttyfd, ptymaster;
 114         int     row, col, xpixel, ypixel;
 115         char    tty[TTYSZ];
 116         /* X11 */
 117         char    *display;
 118         int     screen;
 119         char    *auth_proto;
 120         char    *auth_data;
 121         int     single_connection;
 122         /* proto 2 */
 123         int     chanid;
 124 };
 125
 126 /* func */
 127
 128 Session *session_new(void);
 129 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 130 void    session_pty_cleanup(Session *s);
 131 void    session_proctitle(Session *s);
 132 void    do_exec_pty(Session *s, const char *command, struct passwd * pw);
 133 void    do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
 134 void    do_login(Session *s, const char *command);
 135
 136 void
 137 do_child(const char *command, struct passwd * pw, const char *term,
 138     const char *display, const char *auth_proto,
 139     const char *auth_data, const char *ttyname);
 140
 141 /* import */
 142 extern ServerOptions options;
 143 extern char *__progname;
 144 extern int log_stderr;
 145 extern int debug_flag;
 146 extern u_int utmp_len;
 147
 148 extern int startup_pipe;
 149
 150 /* Local Xauthority file. */
 151 static char *xauthfile;
 152
 153 /* original command from peer. */
 154 char *original_command = NULL;
 155
 156 /* data */
 157 #define MAX_SESSIONS 10
 158 Session sessions[MAX_SESSIONS];
 159
 160 #ifdef WITH_AIXAUTHENTICATE
 161 /* AIX's lastlogin message, set in auth1.c */
 162 char *aixloginmsg;
 163 #endif /* WITH_AIXAUTHENTICATE */
 164
 165 #ifdef HAVE_LOGIN_CAP
 166 static login_cap_t *lc;
 167 #endif
 168
 169 /*
 170  * Remove local Xauthority file.
 171  */
 172 void
 173 xauthfile_cleanup_proc(void *ignore)
 174 {
 175         debug("xauthfile_cleanup_proc called");
 176
 177         if (xauthfile != NULL) {
 178                 char *p;
 179                 unlink(xauthfile);
 180                 p = strrchr(xauthfile, '/');
 181                 if (p != NULL) {
 182                         *p = '\0';
 183                         rmdir(xauthfile);
 184                 }
 185                 xfree(xauthfile);
 186                 xauthfile = NULL;
 187         }
 188 }
 189
 190 /*
 191  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 192  * dropped connection).
 193  */
 194 void
 195 pty_cleanup_proc(void *session)
 196 {
 197         Session *s=session;
 198         if (s == NULL)
 199                 fatal("pty_cleanup_proc: no session");
 200         debug("pty_cleanup_proc: %s", s->tty);
 201
 202         if (s->pid != 0) {
 203                 /* Record that the user has logged out. */
 204                 record_logout(s->pid, s->tty);
 205         }
 206
 207         /* Release the pseudo-tty. */
 208         pty_release(s->tty);
 209 }
 210
 211 /*
 212  * Prepares for an interactive session.  This is called after the user has
 213  * been successfully authenticated.  During this message exchange, pseudo
 214  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 215  * are requested, etc.
 216  */
 217 void
 218 do_authenticated(struct passwd * pw)
 219 {
 220         Session *s;
 221         int type, fd;
 222         int compression_level = 0, enable_compression_after_reply = 0;
 223         int have_pty = 0;
 224         char *command;
 225         int n_bytes;
 226         int plen;
 227         u_int proto_len, data_len, dlen;
 228
 229         /*
 230          * Cancel the alarm we set to limit the time taken for
 231          * authentication.
 232          */
 233         alarm(0);
 234         if (startup_pipe != -1) {
 235                 close(startup_pipe);
 236                 startup_pipe = -1;
 237         }
 238
 239         /*
 240          * Inform the channel mechanism that we are the server side and that
 241          * the client may request to connect to any port at all. (The user
 242          * could do it anyway, and we wouldn\'t know what is permitted except
 243          * by the client telling us, so we can equally well trust the client
 244          * not to request anything bogus.)
 245          */
 246         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 247                 channel_permit_all_opens();
 248
 249         s = session_new();
 250         s->pw = pw;
 251
 252 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 253         if ((lc = login_getclass(pw->pw_class)) == NULL) {
 254                 error("unable to get login class");
 255                 return;
 256         }
 257 #endif
 258
 259         /*
 260          * We stay in this loop until the client requests to execute a shell
 261          * or a command.
 262          */
 263         for (;;) {
 264                 int success = 0;
 265
 266                 /* Get a packet from the client. */
 267                 type = packet_read(&plen);
 268
 269                 /* Process the packet. */
 270                 switch (type) {
 271                 case SSH_CMSG_REQUEST_COMPRESSION:
 272                         packet_integrity_check(plen, 4, type);
 273                         compression_level = packet_get_int();
 274                         if (compression_level < 1 || compression_level > 9) {
 275                                 packet_send_debug("Received illegal compression level %d.",
 276                                      compression_level);
 277                                 break;
 278                         }
 279                         /* Enable compression after we have responded with SUCCESS. */
 280                         enable_compression_after_reply = 1;
 281                         success = 1;
 282                         break;
 283
 284                 case SSH_CMSG_REQUEST_PTY:
 285                         if (no_pty_flag) {
 286                                 debug("Allocating a pty not permitted for this authentication.");
 287                                 break;
 288                         }
 289                         if (have_pty)
 290                                 packet_disconnect("Protocol error: you already have a pty.");
 291
 292                         debug("Allocating pty.");
 293
 294                         /* Allocate a pty and open it. */
 295                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 296                             sizeof(s->tty))) {
 297                                 error("Failed to allocate pty.");
 298                                 break;
 299                         }
 300                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 301                         pty_setowner(pw, s->tty);
 302
 303                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 304                         s->term = packet_get_string(&dlen);
 305                         packet_integrity_check(dlen, strlen(s->term), type);
 306                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 307                         /* Remaining bytes */
 308                         n_bytes = plen - (4 + dlen + 4 * 4);
 309
 310                         if (strcmp(s->term, "") == 0) {
 311                                 xfree(s->term);
 312                                 s->term = NULL;
 313                         }
 314                         /* Get window size from the packet. */
 315                         s->row = packet_get_int();
 316                         s->col = packet_get_int();
 317                         s->xpixel = packet_get_int();
 318                         s->ypixel = packet_get_int();
 319                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 320
 321                         /* Get tty modes from the packet. */
 322                         tty_parse_modes(s->ttyfd, &n_bytes);
 323                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 324
 325                         session_proctitle(s);
 326
 327                         /* Indicate that we now have a pty. */
 328                         success = 1;
 329                         have_pty = 1;
 330                         break;
 331
 332                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 333                         if (!options.x11_forwarding) {
 334                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 335                                 break;
 336                         }
 337                         if (!options.xauth_location) {
 338                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 339                                 break;
 340                         }
 341                         if (no_x11_forwarding_flag) {
 342                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 343                                 break;
 344                         }
 345                         debug("Received request for X11 forwarding with auth spoofing.");
 346                         if (s->display != NULL)
 347                                 packet_disconnect("Protocol error: X11 display already set.");
 348
 349                         s->auth_proto = packet_get_string(&proto_len);
 350                         s->auth_data = packet_get_string(&data_len);
 351                         packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
 352
 353                         if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
 354                                 s->screen = packet_get_int();
 355                         else
 356                                 s->screen = 0;
 357                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 358
 359                         if (s->display == NULL)
 360                                 break;
 361
 362                         /* Setup to always have a local .Xauthority. */
 363                         xauthfile = xmalloc(MAXPATHLEN);
 364                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 365                         temporarily_use_uid(pw->pw_uid);
 366                         if (mkdtemp(xauthfile) == NULL) {
 367                                 restore_uid();
 368                                 error("private X11 dir: mkdtemp %s failed: %s",
 369                                     xauthfile, strerror(errno));
 370                                 xfree(xauthfile);
 371                                 xauthfile = NULL;
 372                                 /* XXXX remove listening channels */
 373                                 break;
 374                         }
 375                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 376                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 377                         if (fd >= 0)
 378                                 close(fd);
 379                         restore_uid();
 380                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 381                         success = 1;
 382                         break;
 383
 384                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 385                         if (no_agent_forwarding_flag || compat13) {
 386                                 debug("Authentication agent forwarding not permitted for this authentication.");
 387                                 break;
 388                         }
 389                         debug("Received authentication agent forwarding request.");
 390                         success = auth_input_request_forwarding(pw);
 391                         break;
 392
 393                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 394                         if (no_port_forwarding_flag) {
 395                                 debug("Port forwarding not permitted for this authentication.");
 396                                 break;
 397                         }
 398                         if (!options.allow_tcp_forwarding) {
 399                                 debug("Port forwarding not permitted.");
 400                                 break;
 401                         }
 402                         debug("Received TCP/IP port forwarding request.");
 403                         channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
 404                         success = 1;
 405                         break;
 406
 407                 case SSH_CMSG_MAX_PACKET_SIZE:
 408                         if (packet_set_maxsize(packet_get_int()) > 0)
 409                                 success = 1;
 410                         break;
 411
 412                 case SSH_CMSG_EXEC_SHELL:
 413                 case SSH_CMSG_EXEC_CMD:
 414                         if (type == SSH_CMSG_EXEC_CMD) {
 415                                 command = packet_get_string(&dlen);
 416                                 debug("Exec command '%.500s'", command);
 417                                 packet_integrity_check(plen, 4 + dlen, type);
 418                         } else {
 419                                 command = NULL;
 420                                 packet_integrity_check(plen, 0, type);
 421                         }
 422                         if (forced_command != NULL) {
 423                                 original_command = command;
 424                                 command = forced_command;
 425                                 debug("Forced command '%.500s'", forced_command);
 426                         }
 427                         if (have_pty)
 428                                 do_exec_pty(s, command, pw);
 429                         else
 430                                 do_exec_no_pty(s, command, pw);
 431
 432                         if (command != NULL)
 433                                 xfree(command);
 434                         /* Cleanup user's local Xauthority file. */
 435                         if (xauthfile)
 436                                 xauthfile_cleanup_proc(NULL);
 437                         return;
 438
 439                 default:
 440                         /*
 441                          * Any unknown messages in this phase are ignored,
 442                          * and a failure message is returned.
 443                          */
 444                         log("Unknown packet type received after authentication: %d", type);
 445                 }
 446                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 447                 packet_send();
 448                 packet_write_wait();
 449
 450                 /* Enable compression now that we have replied if appropriate. */
 451                 if (enable_compression_after_reply) {
 452                         enable_compression_after_reply = 0;
 453                         packet_start_compression(compression_level);
 454                 }
 455         }
 456 }
 457
 458 /*
 459  * This is called to fork and execute a command when we have no tty.  This
 460  * will call do_child from the child, and server_loop from the parent after
 461  * setting up file descriptors and such.
 462  */
 463 void
 464 do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
 465 {
 466         int pid;
 467
 468 #ifdef USE_PIPES
 469         int pin[2], pout[2], perr[2];
 470         /* Allocate pipes for communicating with the program. */
 471         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 472                 packet_disconnect("Could not create pipes: %.100s",
 473                                   strerror(errno));
 474 #else /* USE_PIPES */
 475         int inout[2], err[2];
 476         /* Uses socket pairs to communicate with the program. */
 477         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 478             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 479                 packet_disconnect("Could not create socket pairs: %.100s",
 480                                   strerror(errno));
 481 #endif /* USE_PIPES */
 482         if (s == NULL)
 483                 fatal("do_exec_no_pty: no session");
 484
 485         session_proctitle(s);
 486
 487 #ifdef USE_PAM
 488                         do_pam_setcred();
 489 #endif /* USE_PAM */
 490
 491         /* Fork the child. */
 492         if ((pid = fork()) == 0) {
 493                 /* Child.  Reinitialize the log since the pid has changed. */
 494                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 495
 496                 signal(SIGPIPE, SIG_DFL);
 497
 498                 /*
 499                  * Create a new session and process group since the 4.4BSD
 500                  * setlogin() affects the entire process group.
 501                  */
 502                 if (setsid() < 0)
 503                         error("setsid failed: %.100s", strerror(errno));
 504
 505 #ifdef USE_PIPES
 506                 /*
 507                  * Redirect stdin.  We close the parent side of the socket
 508                  * pair, and make the child side the standard input.
 509                  */
 510                 close(pin[1]);
 511                 if (dup2(pin[0], 0) < 0)
 512                         perror("dup2 stdin");
 513                 close(pin[0]);
 514
 515                 /* Redirect stdout. */
 516                 close(pout[0]);
 517                 if (dup2(pout[1], 1) < 0)
 518                         perror("dup2 stdout");
 519                 close(pout[1]);
 520
 521                 /* Redirect stderr. */
 522                 close(perr[0]);
 523                 if (dup2(perr[1], 2) < 0)
 524                         perror("dup2 stderr");
 525                 close(perr[1]);
 526 #else /* USE_PIPES */
 527                 /*
 528                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 529                  * use the same socket, as some programs (particularly rdist)
 530                  * seem to depend on it.
 531                  */
 532                 close(inout[1]);
 533                 close(err[1]);
 534                 if (dup2(inout[0], 0) < 0)      /* stdin */
 535                         perror("dup2 stdin");
 536                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 537                         perror("dup2 stdout");
 538                 if (dup2(err[0], 2) < 0)        /* stderr */
 539                         perror("dup2 stderr");
 540 #endif /* USE_PIPES */
 541
 542                 /* Do processing for the child (exec command etc). */
 543                 do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
 544                 /* NOTREACHED */
 545         }
 546 #ifdef HAVE_CYGWIN
 547         if (is_winnt)
 548                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 549 #endif
 550         if (pid < 0)
 551                 packet_disconnect("fork failed: %.100s", strerror(errno));
 552         s->pid = pid;
 553         /* Set interactive/non-interactive mode. */
 554         packet_set_interactive(s->display != NULL);
 555 #ifdef USE_PIPES
 556         /* We are the parent.  Close the child sides of the pipes. */
 557         close(pin[0]);
 558         close(pout[1]);
 559         close(perr[1]);
 560
 561         if (compat20) {
 562                 session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
 563         } else {
 564                 /* Enter the interactive session. */
 565                 server_loop(pid, pin[1], pout[0], perr[0]);
 566                 /* server_loop has closed pin[1], pout[1], and perr[1]. */
 567         }
 568 #else /* USE_PIPES */
 569         /* We are the parent.  Close the child sides of the socket pairs. */
 570         close(inout[0]);
 571         close(err[0]);
 572
 573         /*
 574          * Enter the interactive session.  Note: server_loop must be able to
 575          * handle the case that fdin and fdout are the same.
 576          */
 577         if (compat20) {
 578                 session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
 579         } else {
 580                 server_loop(pid, inout[1], inout[1], err[1]);
 581                 /* server_loop has closed inout[1] and err[1]. */
 582         }
 583 #endif /* USE_PIPES */
 584 }
 585
 586 /*
 587  * This is called to fork and execute a command when we have a tty.  This
 588  * will call do_child from the child, and server_loop from the parent after
 589  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 590  * lastlog, and other such operations.
 591  */
 592 void
 593 do_exec_pty(Session *s, const char *command, struct passwd * pw)
 594 {
 595         int fdout, ptyfd, ttyfd, ptymaster;
 596         pid_t pid;
 597
 598         if (s == NULL)
 599                 fatal("do_exec_pty: no session");
 600         ptyfd = s->ptyfd;
 601         ttyfd = s->ttyfd;
 602
 603 #ifdef USE_PAM
 604                         do_pam_session(pw->pw_name, s->tty);
 605                         do_pam_setcred();
 606 #endif /* USE_PAM */
 607
 608         /* Fork the child. */
 609         if ((pid = fork()) == 0) {
 610                 /* Child.  Reinitialize the log because the pid has changed. */
 611                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 612
 613                 signal(SIGPIPE, SIG_DFL);
 614
 615                 /* Close the master side of the pseudo tty. */
 616                 close(ptyfd);
 617
 618                 /* Make the pseudo tty our controlling tty. */
 619                 pty_make_controlling_tty(&ttyfd, s->tty);
 620
 621                 /* Redirect stdin from the pseudo tty. */
 622                 if (dup2(ttyfd, fileno(stdin)) < 0)
 623                         error("dup2 stdin failed: %.100s", strerror(errno));
 624
 625                 /* Redirect stdout to the pseudo tty. */
 626                 if (dup2(ttyfd, fileno(stdout)) < 0)
 627                         error("dup2 stdin failed: %.100s", strerror(errno));
 628
 629                 /* Redirect stderr to the pseudo tty. */
 630                 if (dup2(ttyfd, fileno(stderr)) < 0)
 631                         error("dup2 stdin failed: %.100s", strerror(errno));
 632
 633                 /* Close the extra descriptor for the pseudo tty. */
 634                 close(ttyfd);
 635
 636                 /* record login, etc. similar to login(1) */
 637                 if (!(options.use_login && command == NULL))
 638                         do_login(s, command);
 639
 640                 /* Do common processing for the child, such as execing the command. */
 641                 do_child(command, pw, s->term, s->display, s->auth_proto,
 642                     s->auth_data, s->tty);
 643                 /* NOTREACHED */
 644         }
 645 #ifdef HAVE_CYGWIN
 646         if (is_winnt)
 647                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 648 #endif
 649         if (pid < 0)
 650                 packet_disconnect("fork failed: %.100s", strerror(errno));
 651         s->pid = pid;
 652
 653         /* Parent.  Close the slave side of the pseudo tty. */
 654         close(ttyfd);
 655
 656         /*
 657          * Create another descriptor of the pty master side for use as the
 658          * standard input.  We could use the original descriptor, but this
 659          * simplifies code in server_loop.  The descriptor is bidirectional.
 660          */
 661         fdout = dup(ptyfd);
 662         if (fdout < 0)
 663                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 664
 665         /* we keep a reference to the pty master */
 666         ptymaster = dup(ptyfd);
 667         if (ptymaster < 0)
 668                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 669         s->ptymaster = ptymaster;
 670
 671         /* Enter interactive session. */
 672         packet_set_interactive(1);
 673         if (compat20) {
 674                 session_set_fds(s, ptyfd, fdout, -1);
 675         } else {
 676                 server_loop(pid, ptyfd, fdout, -1);
 677                 /* server_loop _has_ closed ptyfd and fdout. */
 678                 session_pty_cleanup(s);
 679         }
 680 }
 681
 682 const char *
 683 get_remote_name_or_ip(void)
 684 {
 685         static const char *remote = "";
 686         if (utmp_len > 0)
 687                 remote = get_canonical_hostname(options.reverse_mapping_check);
 688         if (utmp_len == 0 || strlen(remote) > utmp_len)
 689                 remote = get_remote_ipaddr();
 690         return remote;
 691 }
 692
 693 /* administrative, login(1)-like work */
 694 void
 695 do_login(Session *s, const char *command)
 696 {
 697         FILE *f;
 698         char *time_string;
 699         char buf[256];
 700         char hostname[MAXHOSTNAMELEN];
 701         socklen_t fromlen;
 702         struct sockaddr_storage from;
 703         struct stat st;
 704         time_t last_login_time;
 705         struct passwd * pw = s->pw;
 706         pid_t pid = getpid();
 707
 708         /*
 709          * Get IP address of client. If the connection is not a socket, let
 710          * the address be 0.0.0.0.
 711          */
 712         memset(&from, 0, sizeof(from));
 713         if (packet_connection_is_on_socket()) {
 714                 fromlen = sizeof(from);
 715                 if (getpeername(packet_get_connection_in(),
 716                      (struct sockaddr *) & from, &fromlen) < 0) {
 717                         debug("getpeername: %.100s", strerror(errno));
 718                         fatal_cleanup();
 719                 }
 720         }
 721
 722         /* Get the time and hostname when the user last logged in. */
 723         hostname[0] = '\0';
 724         last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 725             hostname, sizeof(hostname));
 726
 727         /* Record that there was a login on that tty from the remote host. */
 728         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 729             get_remote_name_or_ip(), (struct sockaddr *)&from);
 730
 731 #ifdef USE_PAM
 732         /*
 733          * If password change is needed, do it now.
 734          * This needs to occur before the ~/.hushlogin check.
 735          */
 736         if (pam_password_change_required()) {
 737                 print_pam_messages();
 738                 do_pam_chauthtok();
 739         }
 740 #endif
 741
 742         /* Done if .hushlogin exists or a command given. */
 743         if (command != NULL)
 744                 return;
 745         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 746 #ifdef HAVE_LOGIN_CAP
 747         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 748 #else
 749         if (stat(buf, &st) >= 0)
 750 #endif
 751                 return;
 752
 753 #ifdef USE_PAM
 754         if (!pam_password_change_required())
 755                 print_pam_messages();
 756 #endif /* USE_PAM */
 757 #ifdef WITH_AIXAUTHENTICATE
 758         if (aixloginmsg && *aixloginmsg)
 759                 printf("%s\n", aixloginmsg);
 760 #endif /* WITH_AIXAUTHENTICATE */
 761
 762         if (last_login_time != 0) {
 763                 time_string = ctime(&last_login_time);
 764                 if (strchr(time_string, '\n'))
 765                         *strchr(time_string, '\n') = 0;
 766                 if (strcmp(hostname, "") == 0)
 767                         printf("Last login: %s\r\n", time_string);
 768                 else
 769                         printf("Last login: %s from %s\r\n", time_string, hostname);
 770         }
 771         if (options.print_motd) {
 772 #ifdef HAVE_LOGIN_CAP
 773                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 774                     "/etc/motd"), "r");
 775 #else
 776                 f = fopen("/etc/motd", "r");
 777 #endif
 778                 if (f) {
 779                         while (fgets(buf, sizeof(buf), f))
 780                                 fputs(buf, stdout);
 781                         fclose(f);
 782                 }
 783         }
 784 }
 785
 786 /*
 787  * Sets the value of the given variable in the environment.  If the variable
 788  * already exists, its value is overriden.
 789  */
 790 void
 791 child_set_env(char ***envp, u_int *envsizep, const char *name,
 792               const char *value)
 793 {
 794         u_int i, namelen;
 795         char **env;
 796
 797         /*
 798          * Find the slot where the value should be stored.  If the variable
 799          * already exists, we reuse the slot; otherwise we append a new slot
 800          * at the end of the array, expanding if necessary.
 801          */
 802         env = *envp;
 803         namelen = strlen(name);
 804         for (i = 0; env[i]; i++)
 805                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 806                         break;
 807         if (env[i]) {
 808                 /* Reuse the slot. */
 809                 xfree(env[i]);
 810         } else {
 811                 /* New variable.  Expand if necessary. */
 812                 if (i >= (*envsizep) - 1) {
 813                         (*envsizep) += 50;
 814                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 815                 }
 816                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 817                 env[i + 1] = NULL;
 818         }
 819
 820         /* Allocate space and format the variable in the appropriate slot. */
 821         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 822         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 823 }
 824
 825 /*
 826  * Reads environment variables from the given file and adds/overrides them
 827  * into the environment.  If the file does not exist, this does nothing.
 828  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 829  * and assignments of the form name=value.  No other forms are allowed.
 830  */
 831 void
 832 read_environment_file(char ***env, u_int *envsize,
 833                       const char *filename)
 834 {
 835         FILE *f;
 836         char buf[4096];
 837         char *cp, *value;
 838
 839         f = fopen(filename, "r");
 840         if (!f)
 841                 return;
 842
 843         while (fgets(buf, sizeof(buf), f)) {
 844                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 845                         ;
 846                 if (!*cp || *cp == '#' || *cp == '\n')
 847                         continue;
 848                 if (strchr(cp, '\n'))
 849                         *strchr(cp, '\n') = '\0';
 850                 value = strchr(cp, '=');
 851                 if (value == NULL) {
 852                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 853                         continue;
 854                 }
 855                 /*
 856                  * Replace the equals sign by nul, and advance value to
 857                  * the value string.
 858                  */
 859                 *value = '\0';
 860                 value++;
 861                 child_set_env(env, envsize, cp, value);
 862         }
 863         fclose(f);
 864 }
 865
 866 #ifdef USE_PAM
 867 /*
 868  * Sets any environment variables which have been specified by PAM
 869  */
 870 void do_pam_environment(char ***env, int *envsize)
 871 {
 872         char *equals, var_name[512], var_val[512];
 873         char **pam_env;
 874         int i;
 875
 876         if ((pam_env = fetch_pam_environment()) == NULL)
 877                 return;
 878
 879         for(i = 0; pam_env[i] != NULL; i++) {
 880                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 881                         continue;
 882
 883                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 884                         memset(var_name, '\0', sizeof(var_name));
 885                         memset(var_val, '\0', sizeof(var_val));
 886
 887                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 888                         strcpy(var_val, equals + 1);
 889
 890                         debug3("PAM environment: %s=%s", var_name, var_val);
 891
 892                         child_set_env(env, envsize, var_name, var_val);
 893                 }
 894         }
 895 }
 896 #endif /* USE_PAM */
 897
 898
 899 #ifdef HAVE_CYGWIN
 900 void copy_environment(char ***env, int *envsize)
 901 {
 902         char *equals, var_name[512], var_val[512];
 903         int i;
 904
 905         for(i = 0; environ[i] != NULL; i++) {
 906                 if ((equals = strstr(environ[i], "=")) == NULL)
 907                         continue;
 908
 909                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 910                         memset(var_name, '\0', sizeof(var_name));
 911                         memset(var_val, '\0', sizeof(var_val));
 912
 913                         strncpy(var_name, environ[i], equals - environ[i]);
 914                         strcpy(var_val, equals + 1);
 915
 916                         debug3("Copy environment: %s=%s", var_name, var_val);
 917
 918                         child_set_env(env, envsize, var_name, var_val);
 919                 }
 920         }
 921 }
 922 #endif
 923
 924 #if defined(HAVE_GETUSERATTR)
 925 /*
 926  * AIX-specific login initialisation
 927  */
 928 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 929 {
 930         struct rlimit rlim;
 931         int slim, hlim;
 932
 933         getrlimit(resource, &rlim);
 934
 935         slim = 0;
 936         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 937                 if (slim < 0) {
 938                         rlim.rlim_cur = RLIM_INFINITY;
 939                 } else if (slim != 0) {
 940                         /* See the wackiness below */
 941                         if (rlim.rlim_cur == slim * mult)
 942                                 slim = 0;
 943                         else
 944                                 rlim.rlim_cur = slim * mult;
 945                 }
 946         }
 947
 948         hlim = 0;
 949         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 950                 if (hlim < 0) {
 951                         rlim.rlim_max = RLIM_INFINITY;
 952                 } else if (hlim != 0) {
 953                         rlim.rlim_max = hlim * mult;
 954                 }
 955         }
 956
 957         /*
 958          * XXX For cpu and fsize the soft limit is set to the hard limit
 959          * if the hard limit is left at its default value and the soft limit
 960          * is changed from its default value, either by requesting it
 961          * (slim == 0) or by setting it to the current default.  At least
 962          * that's how rlogind does it.  If you're confused you're not alone.
 963          * Bug or feature? AIX 4.3.1.2
 964          */
 965         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 966             && hlim == 0 && slim != 0)
 967                 rlim.rlim_max = rlim.rlim_cur;
 968         /* A specified hard limit limits the soft limit */
 969         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 970                 rlim.rlim_cur = rlim.rlim_max;
 971         /* A soft limit can increase a hard limit */
 972         else if (rlim.rlim_cur > rlim.rlim_max)
 973                 rlim.rlim_max = rlim.rlim_cur;
 974
 975         if (setrlimit(resource, &rlim) != 0)
 976                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 977 }
 978
 979 void set_limits_from_userattr(char *user)
 980 {
 981         int mask;
 982         char buf[16];
 983
 984         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 985         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 986         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 987         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 988         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 989         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 990 #if defined(S_UNOFILE)
 991         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
 992 #endif
 993
 994         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
 995                 /* Convert decimal to octal */
 996                 (void) snprintf(buf, sizeof(buf), "%d", mask);
 997                 if (sscanf(buf, "%o", &mask) == 1)
 998                         umask(mask);
 999         }
1000 }
1001 #endif /* defined(HAVE_GETUSERATTR) */
1002
1003 /*
1004  * Performs common processing for the child, such as setting up the
1005  * environment, closing extra file descriptors, setting the user and group
1006  * ids, and executing the command or shell.
1007  */
1008 void
1009 do_child(const char *command, struct passwd * pw, const char *term,
1010          const char *display, const char *auth_proto,
1011          const char *auth_data, const char *ttyname)
1012 {
1013         const char *shell, *hostname = NULL, *cp = NULL;
1014         char buf[256];
1015         char cmd[1024];
1016         FILE *f = NULL;
1017         u_int envsize, i;
1018         char **env;
1019         extern char **environ;
1020         struct stat st;
1021         char *argv[10];
1022 #ifdef WITH_IRIX_PROJECT
1023         prid_t projid;
1024 #endif /* WITH_IRIX_PROJECT */
1025 #ifdef WITH_IRIX_JOBS
1026         jid_t jid = 0;
1027 #else
1028 #ifdef WITH_IRIX_ARRAY
1029         int jid = 0;
1030 #endif /* WITH_IRIX_ARRAY */
1031 #endif /* WITH_IRIX_JOBS */
1032
1033
1034         /* login(1) is only called if we execute the login shell */
1035         if (options.use_login && command != NULL)
1036                 options.use_login = 0;
1037
1038 #ifndef USE_PAM /* pam_nologin handles this */
1039         if (!options.use_login) {
1040 # ifdef HAVE_LOGIN_CAP
1041                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1042                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1043                             _PATH_NOLOGIN), "r");
1044 # else /* HAVE_LOGIN_CAP */
1045                 if (pw->pw_uid)
1046                         f = fopen(_PATH_NOLOGIN, "r");
1047 # endif /* HAVE_LOGIN_CAP */
1048                 if (f) {
1049                         /* /etc/nologin exists.  Print its contents and exit. */
1050                         while (fgets(buf, sizeof(buf), f))
1051                                 fputs(buf, stderr);
1052                         fclose(f);
1053                         exit(254);
1054                 }
1055         }
1056 #endif /* USE_PAM */
1057
1058         /* Set login name, uid, gid, and groups. */
1059         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1060            switch, so we let login(1) to this for us. */
1061         if (!options.use_login) {
1062 #ifdef HAVE_OSF_SIA
1063                 extern char **saved_argv;
1064                 extern int saved_argc;
1065                 char *host = get_canonical_hostname(options.reverse_mapping_check);
1066
1067                 if (sia_become_user(NULL, saved_argc, saved_argv, host,
1068                     pw->pw_name, ttyname, 0, NULL, NULL, SIA_BEU_SETLUID) !=
1069                     SIASUCCESS) {
1070                         perror("sia_become_user");
1071                         exit(1);
1072                 }
1073                 if (setreuid(geteuid(), geteuid()) < 0) {
1074                         perror("setreuid");
1075                         exit(1);
1076                 }
1077 #else /* HAVE_OSF_SIA */
1078 #ifdef HAVE_CYGWIN
1079                 if (is_winnt) {
1080 #else
1081                 if (getuid() == 0 || geteuid() == 0) {
1082 #endif
1083 # ifdef HAVE_GETUSERATTR
1084                         set_limits_from_userattr(pw->pw_name);
1085 # endif /* HAVE_GETUSERATTR */
1086 # ifdef HAVE_LOGIN_CAP
1087                         if (setusercontext(lc, pw, pw->pw_uid,
1088                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1089                                 perror("unable to set user context");
1090                                 exit(1);
1091                         }
1092 # else /* HAVE_LOGIN_CAP */
1093                         if (setlogin(pw->pw_name) < 0)
1094                                 error("setlogin failed: %s", strerror(errno));
1095                         if (setgid(pw->pw_gid) < 0) {
1096                                 perror("setgid");
1097                                 exit(1);
1098                         }
1099                         /* Initialize the group list. */
1100                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1101                                 perror("initgroups");
1102                                 exit(1);
1103                         }
1104                         endgrent();
1105 #  ifdef WITH_IRIX_JOBS
1106                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1107                         if (jid == -1) {
1108                                 fatal("Failed to create job container: %.100s",
1109                                       strerror(errno));
1110                         }
1111 #  endif /* WITH_IRIX_JOBS */
1112 #  ifdef WITH_IRIX_ARRAY
1113                         /* initialize array session */
1114                         if (jid == 0) {
1115                                 if (newarraysess() != 0)
1116                                         fatal("Failed to set up new array session: %.100s",
1117                                               strerror(errno));
1118                         }
1119 #  endif /* WITH_IRIX_ARRAY */
1120 #  ifdef WITH_IRIX_PROJECT
1121                         /* initialize irix project info */
1122                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1123                           debug("Failed to get project id, using projid 0");
1124                           projid = 0;
1125                         }
1126                         if (setprid(projid))
1127                           fatal("Failed to initialize project %d for %s: %.100s",
1128                                 (int)projid, pw->pw_name, strerror(errno));
1129 #  endif /* WITH_IRIX_PROJECT */
1130 #ifdef WITH_IRIX_AUDIT
1131                         if (sysconf(_SC_AUDIT)) {
1132                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1133                                 if (satsetid(pw->pw_uid))
1134                                         debug("error setting satid: %.100s", strerror(errno));
1135                         }
1136 #endif /* WITH_IRIX_AUDIT */
1137
1138                         /* Permanently switch to the desired uid. */
1139                         permanently_set_uid(pw->pw_uid);
1140 # endif /* HAVE_LOGIN_CAP */
1141                 }
1142 #endif /* HAVE_OSF_SIA */
1143
1144 #ifdef HAVE_CYGWIN
1145                 if (is_winnt)
1146 #endif
1147                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1148                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1149         }
1150         /*
1151          * Get the shell from the password data.  An empty shell field is
1152          * legal, and means /bin/sh.
1153          */
1154         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1155 #ifdef HAVE_LOGIN_CAP
1156         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1157 #endif
1158
1159 #ifdef AFS
1160         /* Try to get AFS tokens for the local cell. */
1161         if (k_hasafs()) {
1162                 char cell[64];
1163
1164                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1165                         krb_afslog(cell, 0);
1166
1167                 krb_afslog(0, 0);
1168         }
1169 #endif /* AFS */
1170
1171         /* Initialize the environment. */
1172         envsize = 100;
1173         env = xmalloc(envsize * sizeof(char *));
1174         env[0] = NULL;
1175
1176 #ifdef HAVE_CYGWIN
1177         /*
1178          * The Windows environment contains some setting which are
1179          * important for a running system. They must not be dropped.
1180          */
1181         copy_environment(&env, &envsize);
1182 #endif
1183
1184         if (!options.use_login) {
1185                 /* Set basic environment. */
1186                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1187                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1188                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1189 #ifdef HAVE_LOGIN_CAP
1190                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1191                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1192 #else /* HAVE_LOGIN_CAP */
1193 # ifndef HAVE_CYGWIN
1194                 /*
1195                  * There's no standard path on Windows. The path contains
1196                  * important components pointing to the system directories,
1197                  * needed for loading shared libraries. So the path better
1198                  * remains intact here.
1199                  */
1200                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1201 # endif /* HAVE_CYGWIN */
1202 #endif /* HAVE_LOGIN_CAP */
1203
1204                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1205                          _PATH_MAILDIR, pw->pw_name);
1206                 child_set_env(&env, &envsize, "MAIL", buf);
1207
1208                 /* Normal systems set SHELL by default. */
1209                 child_set_env(&env, &envsize, "SHELL", shell);
1210         }
1211         if (getenv("TZ"))
1212                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1213
1214         /* Set custom environment options from RSA authentication. */
1215         while (custom_environment) {
1216                 struct envstring *ce = custom_environment;
1217                 char *s = ce->s;
1218                 int i;
1219                 for (i = 0; s[i] != '=' && s[i]; i++);
1220                 if (s[i] == '=') {
1221                         s[i] = 0;
1222                         child_set_env(&env, &envsize, s, s + i + 1);
1223                 }
1224                 custom_environment = ce->next;
1225                 xfree(ce->s);
1226                 xfree(ce);
1227         }
1228
1229         snprintf(buf, sizeof buf, "%.50s %d %d",
1230                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1231         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1232
1233         if (ttyname)
1234                 child_set_env(&env, &envsize, "SSH_TTY", ttyname);
1235         if (term)
1236                 child_set_env(&env, &envsize, "TERM", term);
1237         if (display)
1238                 child_set_env(&env, &envsize, "DISPLAY", display);
1239         if (original_command)
1240                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1241                     original_command);
1242
1243 #ifdef _AIX
1244         if ((cp = getenv("AUTHSTATE")) != NULL)
1245                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1246         if ((cp = getenv("KRB5CCNAME")) != NULL)
1247                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1248         read_environment_file(&env, &envsize, "/etc/environment");
1249 #endif
1250
1251 #ifdef KRB4
1252         {
1253                 extern char *ticket;
1254
1255                 if (ticket)
1256                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1257         }
1258 #endif /* KRB4 */
1259
1260 #ifdef USE_PAM
1261         /* Pull in any environment variables that may have been set by PAM. */
1262         do_pam_environment(&env, &envsize);
1263 #endif /* USE_PAM */
1264
1265         if (xauthfile)
1266                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1267         if (auth_get_socket_name() != NULL)
1268                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1269                               auth_get_socket_name());
1270
1271         /* read $HOME/.ssh/environment. */
1272         if (!options.use_login) {
1273                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1274                     pw->pw_dir);
1275                 read_environment_file(&env, &envsize, buf);
1276         }
1277         if (debug_flag) {
1278                 /* dump the environment */
1279                 fprintf(stderr, "Environment:\n");
1280                 for (i = 0; env[i]; i++)
1281                         fprintf(stderr, "  %.200s\n", env[i]);
1282         }
1283         /* we have to stash the hostname before we close our socket. */
1284         if (options.use_login)
1285                 hostname = get_remote_name_or_ip();
1286         /*
1287          * Close the connection descriptors; note that this is the child, and
1288          * the server will still have the socket open, and it is important
1289          * that we do not shutdown it.  Note that the descriptors cannot be
1290          * closed before building the environment, as we call
1291          * get_remote_ipaddr there.
1292          */
1293         if (packet_get_connection_in() == packet_get_connection_out())
1294                 close(packet_get_connection_in());
1295         else {
1296                 close(packet_get_connection_in());
1297                 close(packet_get_connection_out());
1298         }
1299         /*
1300          * Close all descriptors related to channels.  They will still remain
1301          * open in the parent.
1302          */
1303         /* XXX better use close-on-exec? -markus */
1304         channel_close_all();
1305
1306         /*
1307          * Close any extra file descriptors.  Note that there may still be
1308          * descriptors left by system functions.  They will be closed later.
1309          */
1310         endpwent();
1311
1312         /*
1313          * Close any extra open file descriptors so that we don\'t have them
1314          * hanging around in clients.  Note that we want to do this after
1315          * initgroups, because at least on Solaris 2.3 it leaves file
1316          * descriptors open.
1317          */
1318         for (i = 3; i < 64; i++)
1319                 close(i);
1320
1321         /* Change current directory to the user\'s home directory. */
1322         if (chdir(pw->pw_dir) < 0) {
1323                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1324                         pw->pw_dir, strerror(errno));
1325 #ifdef HAVE_LOGIN_CAP
1326                 if (login_getcapbool(lc, "requirehome", 0))
1327                         exit(1);
1328 #endif
1329         }
1330
1331         /*
1332          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1333          * xauth are run in the proper environment.
1334          */
1335         environ = env;
1336
1337         /*
1338          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1339          * in this order).
1340          */
1341         if (!options.use_login) {
1342                 if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1343                         if (debug_flag)
1344                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_USER_RC);
1345
1346                         f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1347                         if (f) {
1348                                 if (auth_proto != NULL && auth_data != NULL)
1349                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1350                                 pclose(f);
1351                         } else
1352                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_USER_RC);
1353                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1354                         if (debug_flag)
1355                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_SYSTEM_RC);
1356
1357                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1358                         if (f) {
1359                                 if (auth_proto != NULL && auth_data != NULL)
1360                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1361                                 pclose(f);
1362                         } else
1363                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_SYSTEM_RC);
1364                 } else if (options.xauth_location != NULL) {
1365                         /* Add authority data to .Xauthority if appropriate. */
1366                         if (auth_proto != NULL && auth_data != NULL) {
1367                                 char *screen = strchr(display, ':');
1368                                 if (debug_flag) {
1369                                         fprintf(stderr,
1370                                             "Running %.100s add %.100s %.100s %.100s\n",
1371                                             options.xauth_location, display,
1372                                             auth_proto, auth_data);
1373 #ifndef HAVE_CYGWIN /* Unix sockets are not supported */
1374                                         if (screen != NULL)
1375                                                 fprintf(stderr,
1376                                                     "Adding %.*s/unix%s %s %s\n",
1377                                                     (int)(screen-display), display,
1378                                                     screen, auth_proto, auth_data);
1379 #endif
1380                                 }
1381                                 snprintf(cmd, sizeof cmd, "%s -q -",
1382                                     options.xauth_location);
1383                                 f = popen(cmd, "w");
1384                                 if (f) {
1385                                         fprintf(f, "add %s %s %s\n", display,
1386                                             auth_proto, auth_data);
1387 #ifndef HAVE_CYGWIN /* Unix sockets are not supported */
1388                                         if (screen != NULL)
1389                                                 fprintf(f, "add %.*s/unix%s %s %s\n",
1390                                                     (int)(screen-display), display,
1391                                                     screen, auth_proto, auth_data);
1392 #endif
1393                                         pclose(f);
1394                                 } else {
1395                                         fprintf(stderr, "Could not run %s\n",
1396                                             cmd);
1397                                 }
1398                         }
1399                 }
1400                 /* Get the last component of the shell name. */
1401                 cp = strrchr(shell, '/');
1402                 if (cp)
1403                         cp++;
1404                 else
1405                         cp = shell;
1406         }
1407         /*
1408          * If we have no command, execute the shell.  In this case, the shell
1409          * name to be passed in argv[0] is preceded by '-' to indicate that
1410          * this is a login shell.
1411          */
1412         if (!command) {
1413                 if (!options.use_login) {
1414                         char buf[256];
1415
1416                         /*
1417                          * Check for mail if we have a tty and it was enabled
1418                          * in server options.
1419                          */
1420                         if (ttyname && options.check_mail) {
1421                                 char *mailbox;
1422                                 struct stat mailstat;
1423                                 mailbox = getenv("MAIL");
1424                                 if (mailbox != NULL) {
1425                                         if (stat(mailbox, &mailstat) != 0 ||
1426                                             mailstat.st_size == 0)
1427                                                 printf("No mail.\n");
1428                                         else if (mailstat.st_mtime < mailstat.st_atime)
1429                                                 printf("You have mail.\n");
1430                                         else
1431                                                 printf("You have new mail.\n");
1432                                 }
1433                         }
1434                         /* Start the shell.  Set initial character to '-'. */
1435                         buf[0] = '-';
1436                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1437                         buf[sizeof(buf) - 1] = 0;
1438
1439                         /* Execute the shell. */
1440                         argv[0] = buf;
1441                         argv[1] = NULL;
1442                         execve(shell, argv, env);
1443
1444                         /* Executing the shell failed. */
1445                         perror(shell);
1446                         exit(1);
1447
1448                 } else {
1449                         /* Launch login(1). */
1450
1451                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1452                              "-p", "-f", "--", pw->pw_name, NULL);
1453
1454                         /* Login couldn't be executed, die. */
1455
1456                         perror("login");
1457                         exit(1);
1458                 }
1459         }
1460         /*
1461          * Execute the command using the user's shell.  This uses the -c
1462          * option to execute the command.
1463          */
1464         argv[0] = (char *) cp;
1465         argv[1] = "-c";
1466         argv[2] = (char *) command;
1467         argv[3] = NULL;
1468         execve(shell, argv, env);
1469         perror(shell);
1470         exit(1);
1471 }
1472
1473 Session *
1474 session_new(void)
1475 {
1476         int i;
1477         static int did_init = 0;
1478         if (!did_init) {
1479                 debug("session_new: init");
1480                 for(i = 0; i < MAX_SESSIONS; i++) {
1481                         sessions[i].used = 0;
1482                         sessions[i].self = i;
1483                 }
1484                 did_init = 1;
1485         }
1486         for(i = 0; i < MAX_SESSIONS; i++) {
1487                 Session *s = &sessions[i];
1488                 if (! s->used) {
1489                         s->pid = 0;
1490                         s->extended = 0;
1491                         s->chanid = -1;
1492                         s->ptyfd = -1;
1493                         s->ttyfd = -1;
1494                         s->term = NULL;
1495                         s->pw = NULL;
1496                         s->display = NULL;
1497                         s->screen = 0;
1498                         s->auth_data = NULL;
1499                         s->auth_proto = NULL;
1500                         s->used = 1;
1501                         s->pw = NULL;
1502                         debug("session_new: session %d", i);
1503                         return s;
1504                 }
1505         }
1506         return NULL;
1507 }
1508
1509 void
1510 session_dump(void)
1511 {
1512         int i;
1513         for(i = 0; i < MAX_SESSIONS; i++) {
1514                 Session *s = &sessions[i];
1515                 debug("dump: used %d session %d %p channel %d pid %d",
1516                     s->used,
1517                     s->self,
1518                     s,
1519                     s->chanid,
1520                     s->pid);
1521         }
1522 }
1523
1524 int
1525 session_open(int chanid)
1526 {
1527         Session *s = session_new();
1528         debug("session_open: channel %d", chanid);
1529         if (s == NULL) {
1530                 error("no more sessions");
1531                 return 0;
1532         }
1533         s->pw = auth_get_user();
1534         if (s->pw == NULL)
1535                 fatal("no user for session %i", s->self);
1536         debug("session_open: session %d: link with channel %d", s->self, chanid);
1537         s->chanid = chanid;
1538         return 1;
1539 }
1540
1541 Session *
1542 session_by_channel(int id)
1543 {
1544         int i;
1545         for(i = 0; i < MAX_SESSIONS; i++) {
1546                 Session *s = &sessions[i];
1547                 if (s->used && s->chanid == id) {
1548                         debug("session_by_channel: session %d channel %d", i, id);
1549                         return s;
1550                 }
1551         }
1552         debug("session_by_channel: unknown channel %d", id);
1553         session_dump();
1554         return NULL;
1555 }
1556
1557 Session *
1558 session_by_pid(pid_t pid)
1559 {
1560         int i;
1561         debug("session_by_pid: pid %d", pid);
1562         for(i = 0; i < MAX_SESSIONS; i++) {
1563                 Session *s = &sessions[i];
1564                 if (s->used && s->pid == pid)
1565                         return s;
1566         }
1567         error("session_by_pid: unknown pid %d", pid);
1568         session_dump();
1569         return NULL;
1570 }
1571
1572 int
1573 session_window_change_req(Session *s)
1574 {
1575         s->col = packet_get_int();
1576         s->row = packet_get_int();
1577         s->xpixel = packet_get_int();
1578         s->ypixel = packet_get_int();
1579         packet_done();
1580         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1581         return 1;
1582 }
1583
1584 int
1585 session_pty_req(Session *s)
1586 {
1587         u_int len;
1588         char *term_modes;       /* encoded terminal modes */
1589
1590         if (no_pty_flag)
1591                 return 0;
1592         if (s->ttyfd != -1)
1593                 return 0;
1594         s->term = packet_get_string(&len);
1595         s->col = packet_get_int();
1596         s->row = packet_get_int();
1597         s->xpixel = packet_get_int();
1598         s->ypixel = packet_get_int();
1599         term_modes = packet_get_string(&len);
1600         packet_done();
1601
1602         if (strcmp(s->term, "") == 0) {
1603                 xfree(s->term);
1604                 s->term = NULL;
1605         }
1606         /* Allocate a pty and open it. */
1607         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1608                 xfree(s->term);
1609                 s->term = NULL;
1610                 s->ptyfd = -1;
1611                 s->ttyfd = -1;
1612                 error("session_pty_req: session %d alloc failed", s->self);
1613                 xfree(term_modes);
1614                 return 0;
1615         }
1616         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1617         /*
1618          * Add a cleanup function to clear the utmp entry and record logout
1619          * time in case we call fatal() (e.g., the connection gets closed).
1620          */
1621         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1622         pty_setowner(s->pw, s->tty);
1623         /* Get window size from the packet. */
1624         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1625
1626         session_proctitle(s);
1627
1628         /* XXX parse and set terminal modes */
1629         xfree(term_modes);
1630         return 1;
1631 }
1632
1633 int
1634 session_subsystem_req(Session *s)
1635 {
1636         u_int len;
1637         int success = 0;
1638         char *subsys = packet_get_string(&len);
1639         int i;
1640
1641         packet_done();
1642         log("subsystem request for %s", subsys);
1643
1644         for (i = 0; i < options.num_subsystems; i++) {
1645                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1646                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1647                         do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1648                         success = 1;
1649                 }
1650         }
1651
1652         if (!success)
1653                 log("subsystem request for %s failed, subsystem not found", subsys);
1654
1655         xfree(subsys);
1656         return success;
1657 }
1658
1659 int
1660 session_x11_req(Session *s)
1661 {
1662         int fd;
1663         if (no_x11_forwarding_flag) {
1664                 debug("X11 forwarding disabled in user configuration file.");
1665                 return 0;
1666         }
1667         if (!options.x11_forwarding) {
1668                 debug("X11 forwarding disabled in server configuration file.");
1669                 return 0;
1670         }
1671         if (xauthfile != NULL) {
1672                 debug("X11 fwd already started.");
1673                 return 0;
1674         }
1675
1676         debug("Received request for X11 forwarding with auth spoofing.");
1677         if (s->display != NULL)
1678                 packet_disconnect("Protocol error: X11 display already set.");
1679
1680         s->single_connection = packet_get_char();
1681         s->auth_proto = packet_get_string(NULL);
1682         s->auth_data = packet_get_string(NULL);
1683         s->screen = packet_get_int();
1684         packet_done();
1685
1686         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1687         if (s->display == NULL) {
1688                 xfree(s->auth_proto);
1689                 xfree(s->auth_data);
1690                 return 0;
1691         }
1692         xauthfile = xmalloc(MAXPATHLEN);
1693         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1694         temporarily_use_uid(s->pw->pw_uid);
1695         if (mkdtemp(xauthfile) == NULL) {
1696                 restore_uid();
1697                 error("private X11 dir: mkdtemp %s failed: %s",
1698                     xauthfile, strerror(errno));
1699                 xfree(xauthfile);
1700                 xauthfile = NULL;
1701                 xfree(s->auth_proto);
1702                 xfree(s->auth_data);
1703                 /* XXXX remove listening channels */
1704                 return 0;
1705         }
1706         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1707         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1708         if (fd >= 0)
1709                 close(fd);
1710         restore_uid();
1711         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1712         return 1;
1713 }
1714
1715 int
1716 session_shell_req(Session *s)
1717 {
1718         /* if forced_command == NULL, the shell is execed */
1719         char *shell = forced_command;
1720         packet_done();
1721         s->extended = 1;
1722         if (s->ttyfd == -1)
1723                 do_exec_no_pty(s, shell, s->pw);
1724         else
1725                 do_exec_pty(s, shell, s->pw);
1726         return 1;
1727 }
1728
1729 int
1730 session_exec_req(Session *s)
1731 {
1732         u_int len;
1733         char *command = packet_get_string(&len);
1734         packet_done();
1735         if (forced_command) {
1736                 original_command = command;
1737                 command = forced_command;
1738                 debug("Forced command '%.500s'", forced_command);
1739         }
1740         s->extended = 1;
1741         if (s->ttyfd == -1)
1742                 do_exec_no_pty(s, command, s->pw);
1743         else
1744                 do_exec_pty(s, command, s->pw);
1745         if (forced_command == NULL)
1746                 xfree(command);
1747         return 1;
1748 }
1749
1750 int
1751 session_auth_agent_req(Session *s)
1752 {
1753         static int called = 0;
1754         packet_done();
1755         if (no_agent_forwarding_flag) {
1756                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1757                 return 0;
1758         }
1759         if (called) {
1760                 return 0;
1761         } else {
1762                 called = 1;
1763                 return auth_input_request_forwarding(s->pw);
1764         }
1765 }
1766
1767 void
1768 session_input_channel_req(int id, void *arg)
1769 {
1770         u_int len;
1771         int reply;
1772         int success = 0;
1773         char *rtype;
1774         Session *s;
1775         Channel *c;
1776
1777         rtype = packet_get_string(&len);
1778         reply = packet_get_char();
1779
1780         s = session_by_channel(id);
1781         if (s == NULL)
1782                 fatal("session_input_channel_req: channel %d: no session", id);
1783         c = channel_lookup(id);
1784         if (c == NULL)
1785                 fatal("session_input_channel_req: channel %d: bad channel", id);
1786
1787         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1788             s->self, id, rtype, reply);
1789
1790         /*
1791          * a session is in LARVAL state until a shell
1792          * or programm is executed
1793          */
1794         if (c->type == SSH_CHANNEL_LARVAL) {
1795                 if (strcmp(rtype, "shell") == 0) {
1796                         success = session_shell_req(s);
1797                 } else if (strcmp(rtype, "exec") == 0) {
1798                         success = session_exec_req(s);
1799                 } else if (strcmp(rtype, "pty-req") == 0) {
1800                         success =  session_pty_req(s);
1801                 } else if (strcmp(rtype, "x11-req") == 0) {
1802                         success = session_x11_req(s);
1803                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1804                         success = session_auth_agent_req(s);
1805                 } else if (strcmp(rtype, "subsystem") == 0) {
1806                         success = session_subsystem_req(s);
1807                 }
1808         }
1809         if (strcmp(rtype, "window-change") == 0) {
1810                 success = session_window_change_req(s);
1811         }
1812
1813         if (reply) {
1814                 packet_start(success ?
1815                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1816                 packet_put_int(c->remote_id);
1817                 packet_send();
1818         }
1819         xfree(rtype);
1820 }
1821
1822 void
1823 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1824 {
1825         if (!compat20)
1826                 fatal("session_set_fds: called for proto != 2.0");
1827         /*
1828          * now that have a child and a pipe to the child,
1829          * we can activate our channel and register the fd's
1830          */
1831         if (s->chanid == -1)
1832                 fatal("no channel for session %d", s->self);
1833         channel_set_fds(s->chanid,
1834             fdout, fdin, fderr,
1835             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1836             1);
1837 }
1838
1839 void
1840 session_pty_cleanup(Session *s)
1841 {
1842         if (s == NULL || s->ttyfd == -1)
1843                 return;
1844
1845         debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1846
1847         /* Cancel the cleanup function. */
1848         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1849
1850         /* Record that the user has logged out. */
1851         record_logout(s->pid, s->tty);
1852
1853         /* Release the pseudo-tty. */
1854         pty_release(s->tty);
1855
1856         /*
1857          * Close the server side of the socket pairs.  We must do this after
1858          * the pty cleanup, so that another process doesn't get this pty
1859          * while we're still cleaning up.
1860          */
1861         if (close(s->ptymaster) < 0)
1862                 error("close(s->ptymaster): %s", strerror(errno));
1863 }
1864
1865 void
1866 session_exit_message(Session *s, int status)
1867 {
1868         Channel *c;
1869         if (s == NULL)
1870                 fatal("session_close: no session");
1871         c = channel_lookup(s->chanid);
1872         if (c == NULL)
1873                 fatal("session_close: session %d: no channel %d",
1874                     s->self, s->chanid);
1875         debug("session_exit_message: session %d channel %d pid %d",
1876             s->self, s->chanid, s->pid);
1877
1878         if (WIFEXITED(status)) {
1879                 channel_request_start(s->chanid,
1880                     "exit-status", 0);
1881                 packet_put_int(WEXITSTATUS(status));
1882                 packet_send();
1883         } else if (WIFSIGNALED(status)) {
1884                 channel_request_start(s->chanid,
1885                     "exit-signal", 0);
1886                 packet_put_int(WTERMSIG(status));
1887 #ifdef WCOREDUMP
1888                 packet_put_char(WCOREDUMP(status));
1889 #else /* WCOREDUMP */
1890                 packet_put_char(0);
1891 #endif /* WCOREDUMP */
1892                 packet_put_cstring("");
1893                 packet_put_cstring("");
1894                 packet_send();
1895         } else {
1896                 /* Some weird exit cause.  Just exit. */
1897                 packet_disconnect("wait returned status %04x.", status);
1898         }
1899
1900         /* disconnect channel */
1901         debug("session_exit_message: release channel %d", s->chanid);
1902         channel_cancel_cleanup(s->chanid);
1903         /*
1904          * emulate a write failure with 'chan_write_failed', nobody will be
1905          * interested in data we write.
1906          * Note that we must not call 'chan_read_failed', since there could
1907          * be some more data waiting in the pipe.
1908          */
1909         if (c->ostate != CHAN_OUTPUT_CLOSED)
1910                 chan_write_failed(c);
1911         s->chanid = -1;
1912 }
1913
1914 void
1915 session_free(Session *s)
1916 {
1917         debug("session_free: session %d pid %d", s->self, s->pid);
1918         if (s->term)
1919                 xfree(s->term);
1920         if (s->display)
1921                 xfree(s->display);
1922         if (s->auth_data)
1923                 xfree(s->auth_data);
1924         if (s->auth_proto)
1925                 xfree(s->auth_proto);
1926         s->used = 0;
1927 }
1928
1929 void
1930 session_close(Session *s)
1931 {
1932         session_pty_cleanup(s);
1933         session_free(s);
1934         session_proctitle(s);
1935 }
1936
1937 void
1938 session_close_by_pid(pid_t pid, int status)
1939 {
1940         Session *s = session_by_pid(pid);
1941         if (s == NULL) {
1942                 debug("session_close_by_pid: no session for pid %d", s->pid);
1943                 return;
1944         }
1945         if (s->chanid != -1)
1946                 session_exit_message(s, status);
1947         session_close(s);
1948 }
1949
1950 /*
1951  * this is called when a channel dies before
1952  * the session 'child' itself dies
1953  */
1954 void
1955 session_close_by_channel(int id, void *arg)
1956 {
1957         Session *s = session_by_channel(id);
1958         if (s == NULL) {
1959                 debug("session_close_by_channel: no session for channel %d", id);
1960                 return;
1961         }
1962         /* disconnect channel */
1963         channel_cancel_cleanup(s->chanid);
1964         s->chanid = -1;
1965
1966         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1967         if (s->pid == 0) {
1968                 /* close session immediately */
1969                 session_close(s);
1970         } else {
1971                 /* notify child, delay session cleanup */
1972                 if (s->pid <= 1)
1973                         fatal("session_close_by_channel: Unsafe s->pid = %d", s->pid);
1974                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1975                         error("session_close_by_channel: kill %d: %s",
1976                             s->pid, strerror(errno));
1977         }
1978 }
1979
1980 char *
1981 session_tty_list(void)
1982 {
1983         static char buf[1024];
1984         int i;
1985         buf[0] = '\0';
1986         for(i = 0; i < MAX_SESSIONS; i++) {
1987                 Session *s = &sessions[i];
1988                 if (s->used && s->ttyfd != -1) {
1989                         if (buf[0] != '\0')
1990                                 strlcat(buf, ",", sizeof buf);
1991                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1992                 }
1993         }
1994         if (buf[0] == '\0')
1995                 strlcpy(buf, "notty", sizeof buf);
1996         return buf;
1997 }
1998
1999 void
2000 session_proctitle(Session *s)
2001 {
2002         if (s->pw == NULL)
2003                 error("no user for session %d", s->self);
2004         else
2005                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2006 }
2007
2008 void
2009 do_authenticated2(Authctxt *authctxt)
2010 {
2011
2012         /*
2013          * Cancel the alarm we set to limit the time taken for
2014          * authentication.
2015          */
2016         alarm(0);
2017         if (startup_pipe != -1) {
2018                 close(startup_pipe);
2019                 startup_pipe = -1;
2020         }
2021 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
2022         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
2023                 error("unable to get login class");
2024                 return;
2025         }
2026 #endif
2027         server_loop2();
2028         if (xauthfile)
2029                 xauthfile_cleanup_proc(NULL);
2030 }