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 1.64 2001/03/20 19:35:29 markus Exp $");
  37
  38 #include "ssh.h"
  39 #include "ssh1.h"
  40 #include "ssh2.h"
  41 #include "xmalloc.h"
  42 #include "sshpty.h"
  43 #include "packet.h"
  44 #include "buffer.h"
  45 #include "mpaux.h"
  46 #include "uidswap.h"
  47 #include "compat.h"
  48 #include "channels.h"
  49 #include "nchan.h"
  50 #include "bufaux.h"
  51 #include "auth.h"
  52 #include "auth-options.h"
  53 #include "pathnames.h"
  54 #include "log.h"
  55 #include "servconf.h"
  56 #include "sshlogin.h"
  57 #include "serverloop.h"
  58 #include "canohost.h"
  59 #include "session.h"
  60
  61 #ifdef WITH_IRIX_PROJECT
  62 #include <proj.h>
  63 #endif /* WITH_IRIX_PROJECT */
  64 #ifdef WITH_IRIX_JOBS
  65 #include <sys/resource.h>
  66 #endif
  67 #ifdef WITH_IRIX_AUDIT
  68 #include <sat.h>
  69 #endif /* WITH_IRIX_AUDIT */
  70
  71 #if defined(HAVE_USERSEC_H)
  72 #include <usersec.h>
  73 #endif
  74
  75 #ifdef HAVE_CYGWIN
  76 #include <windows.h>
  77 #include <sys/cygwin.h>
  78 #define is_winnt       (GetVersion() < 0x80000000)
  79 #endif
  80
  81 /* AIX limits */
  82 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  83 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  84 # define S_UCPU_HARD  S_UCPU "_hard"
  85 # define S_UDATA_HARD  S_UDATA "_hard"
  86 # define S_USTACK_HARD  S_USTACK "_hard"
  87 # define S_URSS_HARD  S_URSS "_hard"
  88 # define S_UCORE_HARD  S_UCORE "_hard"
  89 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  90 #endif
  91
  92 #ifdef _AIX
  93 # include <uinfo.h>
  94 #endif
  95
  96 /* types */
  97
  98 #define TTYSZ 64
  99 typedef struct Session Session;
 100 struct Session {
 101         int     used;
 102         int     self;
 103         struct  passwd *pw;
 104         pid_t   pid;
 105         /* tty */
 106         char    *term;
 107         int     ptyfd, ttyfd, ptymaster;
 108         int     row, col, xpixel, ypixel;
 109         char    tty[TTYSZ];
 110         /* X11 */
 111         char    *display;
 112         int     screen;
 113         char    *auth_proto;
 114         char    *auth_data;
 115         int     single_connection;
 116         /* proto 2 */
 117         int     chanid;
 118         int     is_subsystem;
 119 };
 120
 121 /* func */
 122
 123 Session *session_new(void);
 124 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 125 void    session_pty_cleanup(Session *s);
 126 void    session_proctitle(Session *s);
 127 void    do_exec_pty(Session *s, const char *command);
 128 void    do_exec_no_pty(Session *s, const char *command);
 129 void    do_login(Session *s, const char *command);
 130 void    do_child(Session *s, const char *command);
 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         int screen_flag;
 220
 221         /*
 222          * Cancel the alarm we set to limit the time taken for
 223          * authentication.
 224          */
 225         alarm(0);
 226         if (startup_pipe != -1) {
 227                 close(startup_pipe);
 228                 startup_pipe = -1;
 229         }
 230
 231         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 232                 channel_permit_all_opens();
 233
 234         s = session_new();
 235         s->pw = pw;
 236
 237 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 238         if ((lc = login_getclass(pw->pw_class)) == NULL) {
 239                 error("unable to get login class");
 240                 return;
 241         }
 242 #endif
 243
 244         /*
 245          * We stay in this loop until the client requests to execute a shell
 246          * or a command.
 247          */
 248         for (;;) {
 249                 int success = 0;
 250
 251                 /* Get a packet from the client. */
 252                 type = packet_read(&plen);
 253
 254                 /* Process the packet. */
 255                 switch (type) {
 256                 case SSH_CMSG_REQUEST_COMPRESSION:
 257                         packet_integrity_check(plen, 4, type);
 258                         compression_level = packet_get_int();
 259                         if (compression_level < 1 || compression_level > 9) {
 260                                 packet_send_debug("Received illegal compression level %d.",
 261                                      compression_level);
 262                                 break;
 263                         }
 264                         /* Enable compression after we have responded with SUCCESS. */
 265                         enable_compression_after_reply = 1;
 266                         success = 1;
 267                         break;
 268
 269                 case SSH_CMSG_REQUEST_PTY:
 270                         if (no_pty_flag) {
 271                                 debug("Allocating a pty not permitted for this authentication.");
 272                                 break;
 273                         }
 274                         if (have_pty)
 275                                 packet_disconnect("Protocol error: you already have a pty.");
 276
 277                         debug("Allocating pty.");
 278
 279                         /* Allocate a pty and open it. */
 280                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 281                             sizeof(s->tty))) {
 282                                 error("Failed to allocate pty.");
 283                                 break;
 284                         }
 285                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 286                         pty_setowner(pw, s->tty);
 287
 288                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 289                         s->term = packet_get_string(&dlen);
 290                         packet_integrity_check(dlen, strlen(s->term), type);
 291                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 292                         /* Remaining bytes */
 293                         n_bytes = plen - (4 + dlen + 4 * 4);
 294
 295                         if (strcmp(s->term, "") == 0) {
 296                                 xfree(s->term);
 297                                 s->term = NULL;
 298                         }
 299                         /* Get window size from the packet. */
 300                         s->row = packet_get_int();
 301                         s->col = packet_get_int();
 302                         s->xpixel = packet_get_int();
 303                         s->ypixel = packet_get_int();
 304                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 305
 306                         /* Get tty modes from the packet. */
 307                         tty_parse_modes(s->ttyfd, &n_bytes);
 308                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 309
 310                         session_proctitle(s);
 311
 312                         /* Indicate that we now have a pty. */
 313                         success = 1;
 314                         have_pty = 1;
 315                         break;
 316
 317                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 318                         if (!options.x11_forwarding) {
 319                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 320                                 break;
 321                         }
 322                         if (!options.xauth_location) {
 323                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 324                                 break;
 325                         }
 326                         if (no_x11_forwarding_flag) {
 327                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 328                                 break;
 329                         }
 330                         debug("Received request for X11 forwarding with auth spoofing.");
 331                         if (s->display != NULL)
 332                                 packet_disconnect("Protocol error: X11 display already set.");
 333
 334                         s->auth_proto = packet_get_string(&proto_len);
 335                         s->auth_data = packet_get_string(&data_len);
 336
 337                         screen_flag = packet_get_protocol_flags() &
 338                             SSH_PROTOFLAG_SCREEN_NUMBER;
 339                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 340
 341                         if (packet_remaining() == 4) {
 342                                 if (!screen_flag)
 343                                         debug2("Buggy client: "
 344                                             "X11 screen flag missing");
 345                                 packet_integrity_check(plen,
 346                                     4 + proto_len + 4 + data_len + 4, type);
 347                                 s->screen = packet_get_int();
 348                         } else {
 349                                 packet_integrity_check(plen,
 350                                     4 + proto_len + 4 + data_len, type);
 351                                 s->screen = 0;
 352                         }
 353                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 354
 355                         if (s->display == NULL)
 356                                 break;
 357
 358                         /* Setup to always have a local .Xauthority. */
 359                         xauthfile = xmalloc(MAXPATHLEN);
 360                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 361                         temporarily_use_uid(pw->pw_uid);
 362                         if (mkdtemp(xauthfile) == NULL) {
 363                                 restore_uid();
 364                                 error("private X11 dir: mkdtemp %s failed: %s",
 365                                     xauthfile, strerror(errno));
 366                                 xfree(xauthfile);
 367                                 xauthfile = NULL;
 368                                 /* XXXX remove listening channels */
 369                                 break;
 370                         }
 371                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 372                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 373                         if (fd >= 0)
 374                                 close(fd);
 375                         restore_uid();
 376                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 377                         success = 1;
 378                         break;
 379
 380                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 381                         if (no_agent_forwarding_flag || compat13) {
 382                                 debug("Authentication agent forwarding not permitted for this authentication.");
 383                                 break;
 384                         }
 385                         debug("Received authentication agent forwarding request.");
 386                         success = auth_input_request_forwarding(pw);
 387                         break;
 388
 389                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 390                         if (no_port_forwarding_flag) {
 391                                 debug("Port forwarding not permitted for this authentication.");
 392                                 break;
 393                         }
 394                         if (!options.allow_tcp_forwarding) {
 395                                 debug("Port forwarding not permitted.");
 396                                 break;
 397                         }
 398                         debug("Received TCP/IP port forwarding request.");
 399                         channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
 400                         success = 1;
 401                         break;
 402
 403                 case SSH_CMSG_MAX_PACKET_SIZE:
 404                         if (packet_set_maxsize(packet_get_int()) > 0)
 405                                 success = 1;
 406                         break;
 407
 408                 case SSH_CMSG_EXEC_SHELL:
 409                 case SSH_CMSG_EXEC_CMD:
 410                         if (type == SSH_CMSG_EXEC_CMD) {
 411                                 command = packet_get_string(&dlen);
 412                                 debug("Exec command '%.500s'", command);
 413                                 packet_integrity_check(plen, 4 + dlen, type);
 414                         } else {
 415                                 command = NULL;
 416                                 packet_integrity_check(plen, 0, type);
 417                         }
 418                         if (forced_command != NULL) {
 419                                 original_command = command;
 420                                 command = forced_command;
 421                                 debug("Forced command '%.500s'", forced_command);
 422                         }
 423                         if (have_pty)
 424                                 do_exec_pty(s, command);
 425                         else
 426                                 do_exec_no_pty(s, command);
 427
 428                         if (command != NULL)
 429                                 xfree(command);
 430                         /* Cleanup user's local Xauthority file. */
 431                         if (xauthfile)
 432                                 xauthfile_cleanup_proc(NULL);
 433                         return;
 434
 435                 default:
 436                         /*
 437                          * Any unknown messages in this phase are ignored,
 438                          * and a failure message is returned.
 439                          */
 440                         log("Unknown packet type received after authentication: %d", type);
 441                 }
 442                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 443                 packet_send();
 444                 packet_write_wait();
 445
 446                 /* Enable compression now that we have replied if appropriate. */
 447                 if (enable_compression_after_reply) {
 448                         enable_compression_after_reply = 0;
 449                         packet_start_compression(compression_level);
 450                 }
 451         }
 452 }
 453
 454 /*
 455  * This is called to fork and execute a command when we have no tty.  This
 456  * will call do_child from the child, and server_loop from the parent after
 457  * setting up file descriptors and such.
 458  */
 459 void
 460 do_exec_no_pty(Session *s, const char *command)
 461 {
 462         int pid;
 463
 464 #ifdef USE_PIPES
 465         int pin[2], pout[2], perr[2];
 466         /* Allocate pipes for communicating with the program. */
 467         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 468                 packet_disconnect("Could not create pipes: %.100s",
 469                                   strerror(errno));
 470 #else /* USE_PIPES */
 471         int inout[2], err[2];
 472         /* Uses socket pairs to communicate with the program. */
 473         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 474             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 475                 packet_disconnect("Could not create socket pairs: %.100s",
 476                                   strerror(errno));
 477 #endif /* USE_PIPES */
 478         if (s == NULL)
 479                 fatal("do_exec_no_pty: no session");
 480
 481         session_proctitle(s);
 482
 483 #if defined(USE_PAM)
 484         do_pam_setcred();
 485 #endif /* USE_PAM */
 486
 487         /* Fork the child. */
 488         if ((pid = fork()) == 0) {
 489                 /* Child.  Reinitialize the log since the pid has changed. */
 490                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 491
 492                 signal(SIGPIPE, SIG_DFL);
 493
 494                 /*
 495                  * Create a new session and process group since the 4.4BSD
 496                  * setlogin() affects the entire process group.
 497                  */
 498                 if (setsid() < 0)
 499                         error("setsid failed: %.100s", strerror(errno));
 500
 501 #ifdef USE_PIPES
 502                 /*
 503                  * Redirect stdin.  We close the parent side of the socket
 504                  * pair, and make the child side the standard input.
 505                  */
 506                 close(pin[1]);
 507                 if (dup2(pin[0], 0) < 0)
 508                         perror("dup2 stdin");
 509                 close(pin[0]);
 510
 511                 /* Redirect stdout. */
 512                 close(pout[0]);
 513                 if (dup2(pout[1], 1) < 0)
 514                         perror("dup2 stdout");
 515                 close(pout[1]);
 516
 517                 /* Redirect stderr. */
 518                 close(perr[0]);
 519                 if (dup2(perr[1], 2) < 0)
 520                         perror("dup2 stderr");
 521                 close(perr[1]);
 522 #else /* USE_PIPES */
 523                 /*
 524                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 525                  * use the same socket, as some programs (particularly rdist)
 526                  * seem to depend on it.
 527                  */
 528                 close(inout[1]);
 529                 close(err[1]);
 530                 if (dup2(inout[0], 0) < 0)      /* stdin */
 531                         perror("dup2 stdin");
 532                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 533                         perror("dup2 stdout");
 534                 if (dup2(err[0], 2) < 0)        /* stderr */
 535                         perror("dup2 stderr");
 536 #endif /* USE_PIPES */
 537
 538                 /* Do processing for the child (exec command etc). */
 539                 do_child(s, command);
 540                 /* NOTREACHED */
 541         }
 542 #ifdef HAVE_CYGWIN
 543         if (is_winnt)
 544                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 545 #endif
 546         if (pid < 0)
 547                 packet_disconnect("fork failed: %.100s", strerror(errno));
 548         s->pid = pid;
 549         /* Set interactive/non-interactive mode. */
 550         packet_set_interactive(s->display != NULL);
 551 #ifdef USE_PIPES
 552         /* We are the parent.  Close the child sides of the pipes. */
 553         close(pin[0]);
 554         close(pout[1]);
 555         close(perr[1]);
 556
 557         if (compat20) {
 558                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 559         } else {
 560                 /* Enter the interactive session. */
 561                 server_loop(pid, pin[1], pout[0], perr[0]);
 562                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 563         }
 564 #else /* USE_PIPES */
 565         /* We are the parent.  Close the child sides of the socket pairs. */
 566         close(inout[0]);
 567         close(err[0]);
 568
 569         /*
 570          * Enter the interactive session.  Note: server_loop must be able to
 571          * handle the case that fdin and fdout are the same.
 572          */
 573         if (compat20) {
 574                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 575         } else {
 576                 server_loop(pid, inout[1], inout[1], err[1]);
 577                 /* server_loop has closed inout[1] and err[1]. */
 578         }
 579 #endif /* USE_PIPES */
 580 }
 581
 582 /*
 583  * This is called to fork and execute a command when we have a tty.  This
 584  * will call do_child from the child, and server_loop from the parent after
 585  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 586  * lastlog, and other such operations.
 587  */
 588 void
 589 do_exec_pty(Session *s, const char *command)
 590 {
 591         int fdout, ptyfd, ttyfd, ptymaster;
 592         pid_t pid;
 593
 594         if (s == NULL)
 595                 fatal("do_exec_pty: no session");
 596         ptyfd = s->ptyfd;
 597         ttyfd = s->ttyfd;
 598
 599 #if defined(USE_PAM)
 600         do_pam_session(pw->pw_name, s->tty);
 601         do_pam_setcred();
 602 #endif
 603
 604         /* Fork the child. */
 605         if ((pid = fork()) == 0) {
 606                 /* Child.  Reinitialize the log because the pid has changed. */
 607                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 608
 609                 signal(SIGPIPE, SIG_DFL);
 610
 611                 /* Close the master side of the pseudo tty. */
 612                 close(ptyfd);
 613
 614                 /* Make the pseudo tty our controlling tty. */
 615                 pty_make_controlling_tty(&ttyfd, s->tty);
 616
 617                 /* Redirect stdin from the pseudo tty. */
 618                 if (dup2(ttyfd, fileno(stdin)) < 0)
 619                         error("dup2 stdin failed: %.100s", strerror(errno));
 620
 621                 /* Redirect stdout to the pseudo tty. */
 622                 if (dup2(ttyfd, fileno(stdout)) < 0)
 623                         error("dup2 stdin failed: %.100s", strerror(errno));
 624
 625                 /* Redirect stderr to the pseudo tty. */
 626                 if (dup2(ttyfd, fileno(stderr)) < 0)
 627                         error("dup2 stdin failed: %.100s", strerror(errno));
 628
 629                 /* Close the extra descriptor for the pseudo tty. */
 630                 close(ttyfd);
 631
 632                 /* record login, etc. similar to login(1) */
 633                 if (!(options.use_login && command == NULL))
 634                         do_login(s, command);
 635
 636                 /* Do common processing for the child, such as execing the command. */
 637                 do_child(s, command);
 638                 /* NOTREACHED */
 639         }
 640 #ifdef HAVE_CYGWIN
 641         if (is_winnt)
 642                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 643 #endif
 644         if (pid < 0)
 645                 packet_disconnect("fork failed: %.100s", strerror(errno));
 646         s->pid = pid;
 647
 648         /* Parent.  Close the slave side of the pseudo tty. */
 649         close(ttyfd);
 650
 651         /*
 652          * Create another descriptor of the pty master side for use as the
 653          * standard input.  We could use the original descriptor, but this
 654          * simplifies code in server_loop.  The descriptor is bidirectional.
 655          */
 656         fdout = dup(ptyfd);
 657         if (fdout < 0)
 658                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 659
 660         /* we keep a reference to the pty master */
 661         ptymaster = dup(ptyfd);
 662         if (ptymaster < 0)
 663                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 664         s->ptymaster = ptymaster;
 665
 666         /* Enter interactive session. */
 667         packet_set_interactive(1);
 668         if (compat20) {
 669                 session_set_fds(s, ptyfd, fdout, -1);
 670         } else {
 671                 server_loop(pid, ptyfd, fdout, -1);
 672                 /* server_loop _has_ closed ptyfd and fdout. */
 673                 session_pty_cleanup(s);
 674         }
 675 }
 676
 677 const char *
 678 get_remote_name_or_ip(void)
 679 {
 680         static const char *remote = "";
 681         if (utmp_len > 0)
 682                 remote = get_canonical_hostname(options.reverse_mapping_check);
 683         if (utmp_len == 0 || strlen(remote) > utmp_len)
 684                 remote = get_remote_ipaddr();
 685         return remote;
 686 }
 687
 688 /* administrative, login(1)-like work */
 689 void
 690 do_login(Session *s, const char *command)
 691 {
 692         FILE *f;
 693         char *time_string;
 694         char buf[256];
 695         char hostname[MAXHOSTNAMELEN];
 696         socklen_t fromlen;
 697         struct sockaddr_storage from;
 698         struct stat st;
 699         time_t last_login_time;
 700         struct passwd * pw = s->pw;
 701         pid_t pid = getpid();
 702
 703         /*
 704          * Get IP address of client. If the connection is not a socket, let
 705          * the address be 0.0.0.0.
 706          */
 707         memset(&from, 0, sizeof(from));
 708         if (packet_connection_is_on_socket()) {
 709                 fromlen = sizeof(from);
 710                 if (getpeername(packet_get_connection_in(),
 711                      (struct sockaddr *) & from, &fromlen) < 0) {
 712                         debug("getpeername: %.100s", strerror(errno));
 713                         fatal_cleanup();
 714                 }
 715         }
 716
 717         /* Get the time and hostname when the user last logged in. */
 718         hostname[0] = '\0';
 719         last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 720             hostname, sizeof(hostname));
 721
 722         /* Record that there was a login on that tty from the remote host. */
 723         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 724             get_remote_name_or_ip(), (struct sockaddr *)&from);
 725
 726 #ifdef USE_PAM
 727         /*
 728          * If password change is needed, do it now.
 729          * This needs to occur before the ~/.hushlogin check.
 730          */
 731         if (is_pam_password_change_required()) {
 732                 print_pam_messages();
 733                 do_pam_chauthtok();
 734         }
 735 #endif
 736
 737         /* Done if .hushlogin exists or a command given. */
 738         if (command != NULL)
 739                 return;
 740         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 741 #ifdef HAVE_LOGIN_CAP
 742         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 743 #else
 744         if (stat(buf, &st) >= 0)
 745 #endif
 746                 return;
 747
 748 #ifdef USE_PAM
 749         if (!is_pam_password_change_required())
 750                 print_pam_messages();
 751 #endif /* USE_PAM */
 752 #ifdef WITH_AIXAUTHENTICATE
 753         if (aixloginmsg && *aixloginmsg)
 754                 printf("%s\n", aixloginmsg);
 755 #endif /* WITH_AIXAUTHENTICATE */
 756
 757         if (last_login_time != 0) {
 758                 time_string = ctime(&last_login_time);
 759                 if (strchr(time_string, '\n'))
 760                         *strchr(time_string, '\n') = 0;
 761                 if (strcmp(hostname, "") == 0)
 762                         printf("Last login: %s\r\n", time_string);
 763                 else
 764                         printf("Last login: %s from %s\r\n", time_string, hostname);
 765         }
 766         if (options.print_motd) {
 767 #ifdef HAVE_LOGIN_CAP
 768                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 769                     "/etc/motd"), "r");
 770 #else
 771                 f = fopen("/etc/motd", "r");
 772 #endif
 773                 if (f) {
 774                         while (fgets(buf, sizeof(buf), f))
 775                                 fputs(buf, stdout);
 776                         fclose(f);
 777                 }
 778         }
 779 }
 780
 781 /*
 782  * Sets the value of the given variable in the environment.  If the variable
 783  * already exists, its value is overriden.
 784  */
 785 void
 786 child_set_env(char ***envp, u_int *envsizep, const char *name,
 787               const char *value)
 788 {
 789         u_int i, namelen;
 790         char **env;
 791
 792         /*
 793          * Find the slot where the value should be stored.  If the variable
 794          * already exists, we reuse the slot; otherwise we append a new slot
 795          * at the end of the array, expanding if necessary.
 796          */
 797         env = *envp;
 798         namelen = strlen(name);
 799         for (i = 0; env[i]; i++)
 800                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 801                         break;
 802         if (env[i]) {
 803                 /* Reuse the slot. */
 804                 xfree(env[i]);
 805         } else {
 806                 /* New variable.  Expand if necessary. */
 807                 if (i >= (*envsizep) - 1) {
 808                         (*envsizep) += 50;
 809                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 810                 }
 811                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 812                 env[i + 1] = NULL;
 813         }
 814
 815         /* Allocate space and format the variable in the appropriate slot. */
 816         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 817         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 818 }
 819
 820 /*
 821  * Reads environment variables from the given file and adds/overrides them
 822  * into the environment.  If the file does not exist, this does nothing.
 823  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 824  * and assignments of the form name=value.  No other forms are allowed.
 825  */
 826 void
 827 read_environment_file(char ***env, u_int *envsize,
 828                       const char *filename)
 829 {
 830         FILE *f;
 831         char buf[4096];
 832         char *cp, *value;
 833
 834         f = fopen(filename, "r");
 835         if (!f)
 836                 return;
 837
 838         while (fgets(buf, sizeof(buf), f)) {
 839                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 840                         ;
 841                 if (!*cp || *cp == '#' || *cp == '\n')
 842                         continue;
 843                 if (strchr(cp, '\n'))
 844                         *strchr(cp, '\n') = '\0';
 845                 value = strchr(cp, '=');
 846                 if (value == NULL) {
 847                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 848                         continue;
 849                 }
 850                 /*
 851                  * Replace the equals sign by nul, and advance value to
 852                  * the value string.
 853                  */
 854                 *value = '\0';
 855                 value++;
 856                 child_set_env(env, envsize, cp, value);
 857         }
 858         fclose(f);
 859 }
 860
 861 #ifdef USE_PAM
 862 /*
 863  * Sets any environment variables which have been specified by PAM
 864  */
 865 void do_pam_environment(char ***env, int *envsize)
 866 {
 867         char *equals, var_name[512], var_val[512];
 868         char **pam_env;
 869         int i;
 870
 871         if ((pam_env = fetch_pam_environment()) == NULL)
 872                 return;
 873
 874         for(i = 0; pam_env[i] != NULL; i++) {
 875                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 876                         continue;
 877
 878                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 879                         memset(var_name, '\0', sizeof(var_name));
 880                         memset(var_val, '\0', sizeof(var_val));
 881
 882                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 883                         strcpy(var_val, equals + 1);
 884
 885                         debug3("PAM environment: %s=%s", var_name, var_val);
 886
 887                         child_set_env(env, envsize, var_name, var_val);
 888                 }
 889         }
 890 }
 891 #endif /* USE_PAM */
 892
 893 #ifdef HAVE_CYGWIN
 894 void copy_environment(char ***env, int *envsize)
 895 {
 896         char *equals, var_name[512], var_val[512];
 897         int i;
 898
 899         for(i = 0; environ[i] != NULL; i++) {
 900                 if ((equals = strstr(environ[i], "=")) == NULL)
 901                         continue;
 902
 903                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 904                         memset(var_name, '\0', sizeof(var_name));
 905                         memset(var_val, '\0', sizeof(var_val));
 906
 907                         strncpy(var_name, environ[i], equals - environ[i]);
 908                         strcpy(var_val, equals + 1);
 909
 910                         debug3("Copy environment: %s=%s", var_name, var_val);
 911
 912                         child_set_env(env, envsize, var_name, var_val);
 913                 }
 914         }
 915 }
 916 #endif
 917
 918 #if defined(HAVE_GETUSERATTR)
 919 /*
 920  * AIX-specific login initialisation
 921  */
 922 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 923 {
 924         struct rlimit rlim;
 925         int slim, hlim;
 926
 927         getrlimit(resource, &rlim);
 928
 929         slim = 0;
 930         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 931                 if (slim < 0) {
 932                         rlim.rlim_cur = RLIM_INFINITY;
 933                 } else if (slim != 0) {
 934                         /* See the wackiness below */
 935                         if (rlim.rlim_cur == slim * mult)
 936                                 slim = 0;
 937                         else
 938                                 rlim.rlim_cur = slim * mult;
 939                 }
 940         }
 941
 942         hlim = 0;
 943         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 944                 if (hlim < 0) {
 945                         rlim.rlim_max = RLIM_INFINITY;
 946                 } else if (hlim != 0) {
 947                         rlim.rlim_max = hlim * mult;
 948                 }
 949         }
 950
 951         /*
 952          * XXX For cpu and fsize the soft limit is set to the hard limit
 953          * if the hard limit is left at its default value and the soft limit
 954          * is changed from its default value, either by requesting it
 955          * (slim == 0) or by setting it to the current default.  At least
 956          * that's how rlogind does it.  If you're confused you're not alone.
 957          * Bug or feature? AIX 4.3.1.2
 958          */
 959         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 960             && hlim == 0 && slim != 0)
 961                 rlim.rlim_max = rlim.rlim_cur;
 962         /* A specified hard limit limits the soft limit */
 963         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 964                 rlim.rlim_cur = rlim.rlim_max;
 965         /* A soft limit can increase a hard limit */
 966         else if (rlim.rlim_cur > rlim.rlim_max)
 967                 rlim.rlim_max = rlim.rlim_cur;
 968
 969         if (setrlimit(resource, &rlim) != 0)
 970                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 971 }
 972
 973 void set_limits_from_userattr(char *user)
 974 {
 975         int mask;
 976         char buf[16];
 977
 978         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 979         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 980         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 981         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 982         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 983         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 984 #if defined(S_UNOFILE)
 985         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
 986 #endif
 987
 988         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
 989                 /* Convert decimal to octal */
 990                 (void) snprintf(buf, sizeof(buf), "%d", mask);
 991                 if (sscanf(buf, "%o", &mask) == 1)
 992                         umask(mask);
 993         }
 994 }
 995 #endif /* defined(HAVE_GETUSERATTR) */
 996
 997 /*
 998  * Performs common processing for the child, such as setting up the
 999  * environment, closing extra file descriptors, setting the user and group
1000  * ids, and executing the command or shell.
1001  */
1002 void
1003 do_child(Session *s, const char *command)
1004 {
1005         const char *shell, *hostname = NULL, *cp = NULL;
1006         struct passwd * pw = s->pw;
1007         char buf[256];
1008         char cmd[1024];
1009         FILE *f = NULL;
1010         u_int envsize, i;
1011         char **env;
1012         extern char **environ;
1013         struct stat st;
1014         char *argv[10];
1015         int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1016 #ifdef WITH_IRIX_PROJECT
1017         prid_t projid;
1018 #endif /* WITH_IRIX_PROJECT */
1019 #ifdef WITH_IRIX_JOBS
1020         jid_t jid = 0;
1021 #else
1022 #ifdef WITH_IRIX_ARRAY
1023         int jid = 0;
1024 #endif /* WITH_IRIX_ARRAY */
1025 #endif /* WITH_IRIX_JOBS */
1026
1027         /* login(1) is only called if we execute the login shell */
1028         if (options.use_login && command != NULL)
1029                 options.use_login = 0;
1030
1031 #ifndef USE_PAM /* pam_nologin handles this */
1032         if (!options.use_login) {
1033 # ifdef HAVE_LOGIN_CAP
1034                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1035                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1036                             _PATH_NOLOGIN), "r");
1037 # else /* HAVE_LOGIN_CAP */
1038                 if (pw->pw_uid)
1039                         f = fopen(_PATH_NOLOGIN, "r");
1040 # endif /* HAVE_LOGIN_CAP */
1041                 if (f) {
1042                         /* /etc/nologin exists.  Print its contents and exit. */
1043                         while (fgets(buf, sizeof(buf), f))
1044                                 fputs(buf, stderr);
1045                         fclose(f);
1046                         exit(254);
1047                 }
1048         }
1049 #endif /* USE_PAM */
1050
1051         /* Set login name, uid, gid, and groups. */
1052         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1053            switch, so we let login(1) to this for us. */
1054         if (!options.use_login) {
1055 #ifdef HAVE_OSF_SIA
1056                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1057 #else /* HAVE_OSF_SIA */
1058 #ifdef HAVE_CYGWIN
1059                 if (is_winnt) {
1060 #else
1061                 if (getuid() == 0 || geteuid() == 0) {
1062 #endif
1063 # ifdef HAVE_GETUSERATTR
1064                         set_limits_from_userattr(pw->pw_name);
1065 # endif /* HAVE_GETUSERATTR */
1066 # ifdef HAVE_LOGIN_CAP
1067                         if (setusercontext(lc, pw, pw->pw_uid,
1068                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1069                                 perror("unable to set user context");
1070                                 exit(1);
1071                         }
1072 #ifdef BSD_AUTH
1073                         if (auth_approval(NULL, lc, pw->pw_name, "ssh") <= 0) {
1074                                 error("approval failure for %s", pw->pw_name);
1075                                 fprintf(stderr, "Approval failure");
1076                                 exit(1);
1077                         }
1078 #endif
1079 # else /* HAVE_LOGIN_CAP */
1080 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1081                         /* Sets login uid for accounting */
1082                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1083                                 error("setluid: %s", strerror(errno));
1084 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1085
1086                         if (setlogin(pw->pw_name) < 0)
1087                                 error("setlogin failed: %s", strerror(errno));
1088                         if (setgid(pw->pw_gid) < 0) {
1089                                 perror("setgid");
1090                                 exit(1);
1091                         }
1092                         /* Initialize the group list. */
1093                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1094                                 perror("initgroups");
1095                                 exit(1);
1096                         }
1097                         endgrent();
1098 #  ifdef WITH_IRIX_JOBS
1099                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1100                         if (jid == -1) {
1101                                 fatal("Failed to create job container: %.100s",
1102                                       strerror(errno));
1103                         }
1104 #  endif /* WITH_IRIX_JOBS */
1105 #  ifdef WITH_IRIX_ARRAY
1106                         /* initialize array session */
1107                         if (jid == 0) {
1108                                 if (newarraysess() != 0)
1109                                         fatal("Failed to set up new array session: %.100s",
1110                                               strerror(errno));
1111                         }
1112 #  endif /* WITH_IRIX_ARRAY */
1113 #  ifdef WITH_IRIX_PROJECT
1114                         /* initialize irix project info */
1115                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1116                           debug("Failed to get project id, using projid 0");
1117                           projid = 0;
1118                         }
1119                         if (setprid(projid))
1120                           fatal("Failed to initialize project %d for %s: %.100s",
1121                                 (int)projid, pw->pw_name, strerror(errno));
1122 #  endif /* WITH_IRIX_PROJECT */
1123 #ifdef WITH_IRIX_AUDIT
1124                         if (sysconf(_SC_AUDIT)) {
1125                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1126                                 if (satsetid(pw->pw_uid))
1127                                         debug("error setting satid: %.100s", strerror(errno));
1128                         }
1129 #endif /* WITH_IRIX_AUDIT */
1130
1131 #ifdef _AIX
1132                         /*
1133                          * AIX has a "usrinfo" area where logname and
1134                          * other stuff is stored - a few applications
1135                          * actually use this and die if it's not set
1136                          */
1137                         if (s->ttyfd == -1)
1138                                 s->tty[0] = '\0';
1139                         cp = xmalloc(22 + strlen(s->tty) +
1140                             2 * strlen(pw->pw_name));
1141                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1142                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1143                         if (usrinfo(SETUINFO, cp, i) == -1)
1144                                 fatal("Couldn't set usrinfo: %s",
1145                                     strerror(errno));
1146                         debug3("AIX/UsrInfo: set len %d", i);
1147                         xfree(cp);
1148 #endif
1149
1150                         /* Permanently switch to the desired uid. */
1151                         permanently_set_uid(pw->pw_uid);
1152 # endif /* HAVE_LOGIN_CAP */
1153                 }
1154 #endif /* HAVE_OSF_SIA */
1155
1156 #ifdef HAVE_CYGWIN
1157                 if (is_winnt)
1158 #endif
1159                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1160                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1161         }
1162         /*
1163          * Get the shell from the password data.  An empty shell field is
1164          * legal, and means /bin/sh.
1165          */
1166         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1167 #ifdef HAVE_LOGIN_CAP
1168         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1169 #endif
1170
1171 #ifdef AFS
1172         /* Try to get AFS tokens for the local cell. */
1173         if (k_hasafs()) {
1174                 char cell[64];
1175
1176                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1177                         krb_afslog(cell, 0);
1178
1179                 krb_afslog(0, 0);
1180         }
1181 #endif /* AFS */
1182
1183         /* Initialize the environment. */
1184         envsize = 100;
1185         env = xmalloc(envsize * sizeof(char *));
1186         env[0] = NULL;
1187
1188 #ifdef HAVE_CYGWIN
1189         /*
1190          * The Windows environment contains some setting which are
1191          * important for a running system. They must not be dropped.
1192          */
1193         copy_environment(&env, &envsize);
1194 #endif
1195
1196         if (!options.use_login) {
1197                 /* Set basic environment. */
1198                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1199                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1200                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1201 #ifdef HAVE_LOGIN_CAP
1202                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1203                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1204 #else /* HAVE_LOGIN_CAP */
1205 # ifndef HAVE_CYGWIN
1206                 /*
1207                  * There's no standard path on Windows. The path contains
1208                  * important components pointing to the system directories,
1209                  * needed for loading shared libraries. So the path better
1210                  * remains intact here.
1211                  */
1212                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1213 # endif /* HAVE_CYGWIN */
1214 #endif /* HAVE_LOGIN_CAP */
1215
1216                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1217                          _PATH_MAILDIR, pw->pw_name);
1218                 child_set_env(&env, &envsize, "MAIL", buf);
1219
1220                 /* Normal systems set SHELL by default. */
1221                 child_set_env(&env, &envsize, "SHELL", shell);
1222         }
1223         if (getenv("TZ"))
1224                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1225
1226         /* Set custom environment options from RSA authentication. */
1227         while (custom_environment) {
1228                 struct envstring *ce = custom_environment;
1229                 char *s = ce->s;
1230                 int i;
1231                 for (i = 0; s[i] != '=' && s[i]; i++);
1232                 if (s[i] == '=') {
1233                         s[i] = 0;
1234                         child_set_env(&env, &envsize, s, s + i + 1);
1235                 }
1236                 custom_environment = ce->next;
1237                 xfree(ce->s);
1238                 xfree(ce);
1239         }
1240
1241         snprintf(buf, sizeof buf, "%.50s %d %d",
1242                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1243         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1244
1245         if (s->ttyfd != -1)
1246                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1247         if (s->term)
1248                 child_set_env(&env, &envsize, "TERM", s->term);
1249         if (s->display)
1250                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1251         if (original_command)
1252                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1253                     original_command);
1254
1255 #ifdef _AIX
1256         if ((cp = getenv("AUTHSTATE")) != NULL)
1257                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1258         if ((cp = getenv("KRB5CCNAME")) != NULL)
1259                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1260         read_environment_file(&env, &envsize, "/etc/environment");
1261 #endif
1262
1263 #ifdef KRB4
1264         {
1265                 extern char *ticket;
1266
1267                 if (ticket)
1268                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1269         }
1270 #endif /* KRB4 */
1271
1272 #ifdef USE_PAM
1273         /* Pull in any environment variables that may have been set by PAM. */
1274         do_pam_environment(&env, &envsize);
1275 #endif /* USE_PAM */
1276
1277         if (xauthfile)
1278                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1279         if (auth_get_socket_name() != NULL)
1280                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1281                               auth_get_socket_name());
1282
1283         /* read $HOME/.ssh/environment. */
1284         if (!options.use_login) {
1285                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1286                     pw->pw_dir);
1287                 read_environment_file(&env, &envsize, buf);
1288         }
1289         if (debug_flag) {
1290                 /* dump the environment */
1291                 fprintf(stderr, "Environment:\n");
1292                 for (i = 0; env[i]; i++)
1293                         fprintf(stderr, "  %.200s\n", env[i]);
1294         }
1295         /* we have to stash the hostname before we close our socket. */
1296         if (options.use_login)
1297                 hostname = get_remote_name_or_ip();
1298         /*
1299          * Close the connection descriptors; note that this is the child, and
1300          * the server will still have the socket open, and it is important
1301          * that we do not shutdown it.  Note that the descriptors cannot be
1302          * closed before building the environment, as we call
1303          * get_remote_ipaddr there.
1304          */
1305         if (packet_get_connection_in() == packet_get_connection_out())
1306                 close(packet_get_connection_in());
1307         else {
1308                 close(packet_get_connection_in());
1309                 close(packet_get_connection_out());
1310         }
1311         /*
1312          * Close all descriptors related to channels.  They will still remain
1313          * open in the parent.
1314          */
1315         /* XXX better use close-on-exec? -markus */
1316         channel_close_all();
1317
1318         /*
1319          * Close any extra file descriptors.  Note that there may still be
1320          * descriptors left by system functions.  They will be closed later.
1321          */
1322         endpwent();
1323
1324         /*
1325          * Close any extra open file descriptors so that we don\'t have them
1326          * hanging around in clients.  Note that we want to do this after
1327          * initgroups, because at least on Solaris 2.3 it leaves file
1328          * descriptors open.
1329          */
1330         for (i = 3; i < 64; i++)
1331                 close(i);
1332
1333         /* Change current directory to the user\'s home directory. */
1334         if (chdir(pw->pw_dir) < 0) {
1335                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1336                         pw->pw_dir, strerror(errno));
1337 #ifdef HAVE_LOGIN_CAP
1338                 if (login_getcapbool(lc, "requirehome", 0))
1339                         exit(1);
1340 #endif
1341         }
1342
1343         /*
1344          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1345          * xauth are run in the proper environment.
1346          */
1347         environ = env;
1348
1349         /*
1350          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1351          * in this order).
1352          */
1353         if (!options.use_login) {
1354                 if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1355                         if (debug_flag)
1356                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1357                                     _PATH_SSH_USER_RC);
1358                         f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1359                         if (f) {
1360                                 if (do_xauth)
1361                                         fprintf(f, "%s %s\n", s->auth_proto,
1362                                             s->auth_data);
1363                                 pclose(f);
1364                         } else
1365                                 fprintf(stderr, "Could not run %s\n",
1366                                     _PATH_SSH_USER_RC);
1367                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1368                         if (debug_flag)
1369                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1370                                     _PATH_SSH_SYSTEM_RC);
1371
1372                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1373                         if (f) {
1374                                 if (do_xauth)
1375                                         fprintf(f, "%s %s\n", s->auth_proto,
1376                                             s->auth_data);
1377                                 pclose(f);
1378                         } else
1379                                 fprintf(stderr, "Could not run %s\n",
1380                                     _PATH_SSH_SYSTEM_RC);
1381                 } else if (do_xauth && options.xauth_location != NULL) {
1382                         /* Add authority data to .Xauthority if appropriate. */
1383                         char *screen = strchr(s->display, ':');
1384
1385                         if (debug_flag) {
1386                                 fprintf(stderr,
1387                                     "Running %.100s add "
1388                                     "%.100s %.100s %.100s\n",
1389                                     options.xauth_location, s->display,
1390                                     s->auth_proto, s->auth_data);
1391                                 if (screen != NULL)
1392                                         fprintf(stderr,
1393                                             "Adding %.*s/unix%s %s %s\n",
1394                                             (int)(screen - s->display),
1395                                             s->display, screen,
1396                                             s->auth_proto, s->auth_data);
1397                         }
1398                         snprintf(cmd, sizeof cmd, "%s -q -",
1399                             options.xauth_location);
1400                         f = popen(cmd, "w");
1401                         if (f) {
1402                                 fprintf(f, "add %s %s %s\n", s->display,
1403                                     s->auth_proto, s->auth_data);
1404                                 if (screen != NULL)
1405                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1406                                             (int)(screen - s->display),
1407                                             s->display, screen,
1408                                             s->auth_proto,
1409                                             s->auth_data);
1410                                 pclose(f);
1411                         } else {
1412                                 fprintf(stderr, "Could not run %s\n",
1413                                     cmd);
1414                         }
1415                 }
1416                 /* Get the last component of the shell name. */
1417                 cp = strrchr(shell, '/');
1418                 if (cp)
1419                         cp++;
1420                 else
1421                         cp = shell;
1422         }
1423         /*
1424          * If we have no command, execute the shell.  In this case, the shell
1425          * name to be passed in argv[0] is preceded by '-' to indicate that
1426          * this is a login shell.
1427          */
1428         if (!command) {
1429                 if (!options.use_login) {
1430                         char buf[256];
1431
1432                         /*
1433                          * Check for mail if we have a tty and it was enabled
1434                          * in server options.
1435                          */
1436                         if (s->ttyfd != -1 && options.check_mail) {
1437                                 char *mailbox;
1438                                 struct stat mailstat;
1439
1440                                 mailbox = getenv("MAIL");
1441                                 if (mailbox != NULL) {
1442                                         if (stat(mailbox, &mailstat) != 0 ||
1443                                             mailstat.st_size == 0)
1444                                                 printf("No mail.\n");
1445                                         else if (mailstat.st_mtime < mailstat.st_atime)
1446                                                 printf("You have mail.\n");
1447                                         else
1448                                                 printf("You have new mail.\n");
1449                                 }
1450                         }
1451                         /* Start the shell.  Set initial character to '-'. */
1452                         buf[0] = '-';
1453                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1454                         buf[sizeof(buf) - 1] = 0;
1455
1456                         /* Execute the shell. */
1457                         argv[0] = buf;
1458                         argv[1] = NULL;
1459                         execve(shell, argv, env);
1460
1461                         /* Executing the shell failed. */
1462                         perror(shell);
1463                         exit(1);
1464
1465                 } else {
1466                         /* Launch login(1). */
1467
1468                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1469                              "-p", "-f", "--", pw->pw_name, NULL);
1470
1471                         /* Login couldn't be executed, die. */
1472
1473                         perror("login");
1474                         exit(1);
1475                 }
1476         }
1477         /*
1478          * Execute the command using the user's shell.  This uses the -c
1479          * option to execute the command.
1480          */
1481         argv[0] = (char *) cp;
1482         argv[1] = "-c";
1483         argv[2] = (char *) command;
1484         argv[3] = NULL;
1485         execve(shell, argv, env);
1486         perror(shell);
1487         exit(1);
1488 }
1489
1490 Session *
1491 session_new(void)
1492 {
1493         int i;
1494         static int did_init = 0;
1495         if (!did_init) {
1496                 debug("session_new: init");
1497                 for(i = 0; i < MAX_SESSIONS; i++) {
1498                         sessions[i].used = 0;
1499                         sessions[i].self = i;
1500                 }
1501                 did_init = 1;
1502         }
1503         for(i = 0; i < MAX_SESSIONS; i++) {
1504                 Session *s = &sessions[i];
1505                 if (! s->used) {
1506                         s->pid = 0;
1507                         s->is_subsystem = 0;
1508                         s->chanid = -1;
1509                         s->ptyfd = -1;
1510                         s->ttyfd = -1;
1511                         s->term = NULL;
1512                         s->pw = NULL;
1513                         s->display = NULL;
1514                         s->screen = 0;
1515                         s->auth_data = NULL;
1516                         s->auth_proto = NULL;
1517                         s->used = 1;
1518                         s->pw = NULL;
1519                         debug("session_new: session %d", i);
1520                         return s;
1521                 }
1522         }
1523         return NULL;
1524 }
1525
1526 void
1527 session_dump(void)
1528 {
1529         int i;
1530         for(i = 0; i < MAX_SESSIONS; i++) {
1531                 Session *s = &sessions[i];
1532                 debug("dump: used %d session %d %p channel %d pid %d",
1533                     s->used,
1534                     s->self,
1535                     s,
1536                     s->chanid,
1537                     s->pid);
1538         }
1539 }
1540
1541 int
1542 session_open(int chanid)
1543 {
1544         Session *s = session_new();
1545         debug("session_open: channel %d", chanid);
1546         if (s == NULL) {
1547                 error("no more sessions");
1548                 return 0;
1549         }
1550         s->pw = auth_get_user();
1551         if (s->pw == NULL)
1552                 fatal("no user for session %d", s->self);
1553         debug("session_open: session %d: link with channel %d", s->self, chanid);
1554         s->chanid = chanid;
1555         return 1;
1556 }
1557
1558 Session *
1559 session_by_channel(int id)
1560 {
1561         int i;
1562         for(i = 0; i < MAX_SESSIONS; i++) {
1563                 Session *s = &sessions[i];
1564                 if (s->used && s->chanid == id) {
1565                         debug("session_by_channel: session %d channel %d", i, id);
1566                         return s;
1567                 }
1568         }
1569         debug("session_by_channel: unknown channel %d", id);
1570         session_dump();
1571         return NULL;
1572 }
1573
1574 Session *
1575 session_by_pid(pid_t pid)
1576 {
1577         int i;
1578         debug("session_by_pid: pid %d", pid);
1579         for(i = 0; i < MAX_SESSIONS; i++) {
1580                 Session *s = &sessions[i];
1581                 if (s->used && s->pid == pid)
1582                         return s;
1583         }
1584         error("session_by_pid: unknown pid %d", pid);
1585         session_dump();
1586         return NULL;
1587 }
1588
1589 int
1590 session_window_change_req(Session *s)
1591 {
1592         s->col = packet_get_int();
1593         s->row = packet_get_int();
1594         s->xpixel = packet_get_int();
1595         s->ypixel = packet_get_int();
1596         packet_done();
1597         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1598         return 1;
1599 }
1600
1601 int
1602 session_pty_req(Session *s)
1603 {
1604         u_int len;
1605         char *term_modes;       /* encoded terminal modes */
1606
1607         if (no_pty_flag)
1608                 return 0;
1609         if (s->ttyfd != -1)
1610                 return 0;
1611         s->term = packet_get_string(&len);
1612         s->col = packet_get_int();
1613         s->row = packet_get_int();
1614         s->xpixel = packet_get_int();
1615         s->ypixel = packet_get_int();
1616         term_modes = packet_get_string(&len);
1617         packet_done();
1618
1619         if (strcmp(s->term, "") == 0) {
1620                 xfree(s->term);
1621                 s->term = NULL;
1622         }
1623         /* Allocate a pty and open it. */
1624         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1625                 xfree(s->term);
1626                 s->term = NULL;
1627                 s->ptyfd = -1;
1628                 s->ttyfd = -1;
1629                 error("session_pty_req: session %d alloc failed", s->self);
1630                 xfree(term_modes);
1631                 return 0;
1632         }
1633         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1634         /*
1635          * Add a cleanup function to clear the utmp entry and record logout
1636          * time in case we call fatal() (e.g., the connection gets closed).
1637          */
1638         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1639         pty_setowner(s->pw, s->tty);
1640         /* Get window size from the packet. */
1641         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1642
1643         session_proctitle(s);
1644
1645         /* XXX parse and set terminal modes */
1646         xfree(term_modes);
1647         return 1;
1648 }
1649
1650 int
1651 session_subsystem_req(Session *s)
1652 {
1653         u_int len;
1654         int success = 0;
1655         char *subsys = packet_get_string(&len);
1656         int i;
1657
1658         packet_done();
1659         log("subsystem request for %s", subsys);
1660
1661         for (i = 0; i < options.num_subsystems; i++) {
1662                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1663                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1664                         s->is_subsystem = 1;
1665                         do_exec_no_pty(s, options.subsystem_command[i]);
1666                         success = 1;
1667                 }
1668         }
1669
1670         if (!success)
1671                 log("subsystem request for %s failed, subsystem not found", subsys);
1672
1673         xfree(subsys);
1674         return success;
1675 }
1676
1677 int
1678 session_x11_req(Session *s)
1679 {
1680         int fd;
1681         if (no_x11_forwarding_flag) {
1682                 debug("X11 forwarding disabled in user configuration file.");
1683                 return 0;
1684         }
1685         if (!options.x11_forwarding) {
1686                 debug("X11 forwarding disabled in server configuration file.");
1687                 return 0;
1688         }
1689         if (xauthfile != NULL) {
1690                 debug("X11 fwd already started.");
1691                 return 0;
1692         }
1693
1694         debug("Received request for X11 forwarding with auth spoofing.");
1695         if (s->display != NULL)
1696                 packet_disconnect("Protocol error: X11 display already set.");
1697
1698         s->single_connection = packet_get_char();
1699         s->auth_proto = packet_get_string(NULL);
1700         s->auth_data = packet_get_string(NULL);
1701         s->screen = packet_get_int();
1702         packet_done();
1703
1704         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1705         if (s->display == NULL) {
1706                 xfree(s->auth_proto);
1707                 xfree(s->auth_data);
1708                 return 0;
1709         }
1710         xauthfile = xmalloc(MAXPATHLEN);
1711         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1712         temporarily_use_uid(s->pw->pw_uid);
1713         if (mkdtemp(xauthfile) == NULL) {
1714                 restore_uid();
1715                 error("private X11 dir: mkdtemp %s failed: %s",
1716                     xauthfile, strerror(errno));
1717                 xfree(xauthfile);
1718                 xauthfile = NULL;
1719                 xfree(s->auth_proto);
1720                 xfree(s->auth_data);
1721                 /* XXXX remove listening channels */
1722                 return 0;
1723         }
1724         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1725         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1726         if (fd >= 0)
1727                 close(fd);
1728         restore_uid();
1729         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1730         return 1;
1731 }
1732
1733 int
1734 session_shell_req(Session *s)
1735 {
1736         /* if forced_command == NULL, the shell is execed */
1737         char *shell = forced_command;
1738         packet_done();
1739         if (s->ttyfd == -1)
1740                 do_exec_no_pty(s, shell);
1741         else
1742                 do_exec_pty(s, shell);
1743         return 1;
1744 }
1745
1746 int
1747 session_exec_req(Session *s)
1748 {
1749         u_int len;
1750         char *command = packet_get_string(&len);
1751         packet_done();
1752         if (forced_command) {
1753                 original_command = command;
1754                 command = forced_command;
1755                 debug("Forced command '%.500s'", forced_command);
1756         }
1757         if (s->ttyfd == -1)
1758                 do_exec_no_pty(s, command);
1759         else
1760                 do_exec_pty(s, command);
1761         if (forced_command == NULL)
1762                 xfree(command);
1763         return 1;
1764 }
1765
1766 int
1767 session_auth_agent_req(Session *s)
1768 {
1769         static int called = 0;
1770         packet_done();
1771         if (no_agent_forwarding_flag) {
1772                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1773                 return 0;
1774         }
1775         if (called) {
1776                 return 0;
1777         } else {
1778                 called = 1;
1779                 return auth_input_request_forwarding(s->pw);
1780         }
1781 }
1782
1783 void
1784 session_input_channel_req(int id, void *arg)
1785 {
1786         u_int len;
1787         int reply;
1788         int success = 0;
1789         char *rtype;
1790         Session *s;
1791         Channel *c;
1792
1793         rtype = packet_get_string(&len);
1794         reply = packet_get_char();
1795
1796         s = session_by_channel(id);
1797         if (s == NULL)
1798                 fatal("session_input_channel_req: channel %d: no session", id);
1799         c = channel_lookup(id);
1800         if (c == NULL)
1801                 fatal("session_input_channel_req: channel %d: bad channel", id);
1802
1803         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1804             s->self, id, rtype, reply);
1805
1806         /*
1807          * a session is in LARVAL state until a shell, a command
1808          * or a subsystem is executed
1809          */
1810         if (c->type == SSH_CHANNEL_LARVAL) {
1811                 if (strcmp(rtype, "shell") == 0) {
1812                         success = session_shell_req(s);
1813                 } else if (strcmp(rtype, "exec") == 0) {
1814                         success = session_exec_req(s);
1815                 } else if (strcmp(rtype, "pty-req") == 0) {
1816                         success =  session_pty_req(s);
1817                 } else if (strcmp(rtype, "x11-req") == 0) {
1818                         success = session_x11_req(s);
1819                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1820                         success = session_auth_agent_req(s);
1821                 } else if (strcmp(rtype, "subsystem") == 0) {
1822                         success = session_subsystem_req(s);
1823                 }
1824         }
1825         if (strcmp(rtype, "window-change") == 0) {
1826                 success = session_window_change_req(s);
1827         }
1828
1829         if (reply) {
1830                 packet_start(success ?
1831                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1832                 packet_put_int(c->remote_id);
1833                 packet_send();
1834         }
1835         xfree(rtype);
1836 }
1837
1838 void
1839 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1840 {
1841         if (!compat20)
1842                 fatal("session_set_fds: called for proto != 2.0");
1843         /*
1844          * now that have a child and a pipe to the child,
1845          * we can activate our channel and register the fd's
1846          */
1847         if (s->chanid == -1)
1848                 fatal("no channel for session %d", s->self);
1849         channel_set_fds(s->chanid,
1850             fdout, fdin, fderr,
1851             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1852             1);
1853 }
1854
1855 void
1856 session_pty_cleanup(Session *s)
1857 {
1858         if (s == NULL || s->ttyfd == -1)
1859                 return;
1860
1861         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1862
1863         /* Cancel the cleanup function. */
1864         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1865
1866         /* Record that the user has logged out. */
1867         record_logout(s->pid, s->tty);
1868
1869         /* Release the pseudo-tty. */
1870         pty_release(s->tty);
1871
1872         /*
1873          * Close the server side of the socket pairs.  We must do this after
1874          * the pty cleanup, so that another process doesn't get this pty
1875          * while we're still cleaning up.
1876          */
1877         if (close(s->ptymaster) < 0)
1878                 error("close(s->ptymaster): %s", strerror(errno));
1879 }
1880
1881 void
1882 session_exit_message(Session *s, int status)
1883 {
1884         Channel *c;
1885         if (s == NULL)
1886                 fatal("session_close: no session");
1887         c = channel_lookup(s->chanid);
1888         if (c == NULL)
1889                 fatal("session_close: session %d: no channel %d",
1890                     s->self, s->chanid);
1891         debug("session_exit_message: session %d channel %d pid %d",
1892             s->self, s->chanid, s->pid);
1893
1894         if (WIFEXITED(status)) {
1895                 channel_request_start(s->chanid,
1896                     "exit-status", 0);
1897                 packet_put_int(WEXITSTATUS(status));
1898                 packet_send();
1899         } else if (WIFSIGNALED(status)) {
1900                 channel_request_start(s->chanid,
1901                     "exit-signal", 0);
1902                 packet_put_int(WTERMSIG(status));
1903 #ifdef WCOREDUMP
1904                 packet_put_char(WCOREDUMP(status));
1905 #else /* WCOREDUMP */
1906                 packet_put_char(0);
1907 #endif /* WCOREDUMP */
1908                 packet_put_cstring("");
1909                 packet_put_cstring("");
1910                 packet_send();
1911         } else {
1912                 /* Some weird exit cause.  Just exit. */
1913                 packet_disconnect("wait returned status %04x.", status);
1914         }
1915
1916         /* disconnect channel */
1917         debug("session_exit_message: release channel %d", s->chanid);
1918         channel_cancel_cleanup(s->chanid);
1919         /*
1920          * emulate a write failure with 'chan_write_failed', nobody will be
1921          * interested in data we write.
1922          * Note that we must not call 'chan_read_failed', since there could
1923          * be some more data waiting in the pipe.
1924          */
1925         if (c->ostate != CHAN_OUTPUT_CLOSED)
1926                 chan_write_failed(c);
1927         s->chanid = -1;
1928 }
1929
1930 void
1931 session_free(Session *s)
1932 {
1933         debug("session_free: session %d pid %d", s->self, s->pid);
1934         if (s->term)
1935                 xfree(s->term);
1936         if (s->display)
1937                 xfree(s->display);
1938         if (s->auth_data)
1939                 xfree(s->auth_data);
1940         if (s->auth_proto)
1941                 xfree(s->auth_proto);
1942         s->used = 0;
1943 }
1944
1945 void
1946 session_close(Session *s)
1947 {
1948         session_pty_cleanup(s);
1949         session_free(s);
1950         session_proctitle(s);
1951 }
1952
1953 void
1954 session_close_by_pid(pid_t pid, int status)
1955 {
1956         Session *s = session_by_pid(pid);
1957         if (s == NULL) {
1958                 debug("session_close_by_pid: no session for pid %d", s->pid);
1959                 return;
1960         }
1961         if (s->chanid != -1)
1962                 session_exit_message(s, status);
1963         session_close(s);
1964 }
1965
1966 /*
1967  * this is called when a channel dies before
1968  * the session 'child' itself dies
1969  */
1970 void
1971 session_close_by_channel(int id, void *arg)
1972 {
1973         Session *s = session_by_channel(id);
1974         if (s == NULL) {
1975                 debug("session_close_by_channel: no session for channel %d", id);
1976                 return;
1977         }
1978         /* disconnect channel */
1979         channel_cancel_cleanup(s->chanid);
1980         s->chanid = -1;
1981
1982         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1983         if (s->pid == 0) {
1984                 /* close session immediately */
1985                 session_close(s);
1986         } else {
1987                 /* notify child, delay session cleanup */
1988                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1989                         error("session_close_by_channel: kill %d: %s",
1990                             s->pid, strerror(errno));
1991         }
1992 }
1993
1994 char *
1995 session_tty_list(void)
1996 {
1997         static char buf[1024];
1998         int i;
1999         buf[0] = '\0';
2000         for(i = 0; i < MAX_SESSIONS; i++) {
2001                 Session *s = &sessions[i];
2002                 if (s->used && s->ttyfd != -1) {
2003                         if (buf[0] != '\0')
2004                                 strlcat(buf, ",", sizeof buf);
2005                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2006                 }
2007         }
2008         if (buf[0] == '\0')
2009                 strlcpy(buf, "notty", sizeof buf);
2010         return buf;
2011 }
2012
2013 void
2014 session_proctitle(Session *s)
2015 {
2016         if (s->pw == NULL)
2017                 error("no user for session %d", s->self);
2018         else
2019                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2020 }
2021
2022 void
2023 do_authenticated2(Authctxt *authctxt)
2024 {
2025         /*
2026          * Cancel the alarm we set to limit the time taken for
2027          * authentication.
2028          */
2029         alarm(0);
2030         if (startup_pipe != -1) {
2031                 close(startup_pipe);
2032                 startup_pipe = -1;
2033         }
2034         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
2035                 channel_permit_all_opens();
2036 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
2037         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
2038                 error("unable to get login class");
2039                 return;
2040         }
2041 #endif
2042         server_loop2();
2043         if (xauthfile)
2044                 xauthfile_cleanup_proc(NULL);
2045 }