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 1.75 2001/05/03 15:45:15 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 #ifdef LOGIN_NEEDS_UTMPX
 131 void    do_pre_login(Session *s);
 132 #endif
 133 void    do_child(Session *s, const char *command);
 134 void    do_motd(void);
 135 int     check_quietlogin(Session *s, const char *command);
 136
 137 void    do_authenticated1(Authctxt *authctxt);
 138 void    do_authenticated2(Authctxt *authctxt);
 139
 140 /* import */
 141 extern ServerOptions options;
 142 extern char *__progname;
 143 extern int log_stderr;
 144 extern int debug_flag;
 145 extern u_int utmp_len;
 146 extern int startup_pipe;
 147 extern void destroy_sensitive_data(void);
 148
 149 /* Local Xauthority file. */
 150 static char *xauthfile;
 151
 152 /* original command from peer. */
 153 char *original_command = NULL;
 154
 155 /* data */
 156 #define MAX_SESSIONS 10
 157 Session sessions[MAX_SESSIONS];
 158
 159 #ifdef WITH_AIXAUTHENTICATE
 160 /* AIX's lastlogin message, set in auth1.c */
 161 char *aixloginmsg;
 162 #endif /* WITH_AIXAUTHENTICATE */
 163
 164 #ifdef HAVE_LOGIN_CAP
 165 static login_cap_t *lc;
 166 #endif
 167
 168 void
 169 do_authenticated(Authctxt *authctxt)
 170 {
 171         /*
 172          * Cancel the alarm we set to limit the time taken for
 173          * authentication.
 174          */
 175         alarm(0);
 176         if (startup_pipe != -1) {
 177                 close(startup_pipe);
 178                 startup_pipe = -1;
 179         }
 180 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 181         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 182                 error("unable to get login class");
 183                 return;
 184         }
 185 #ifdef BSD_AUTH
 186         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 187                 packet_disconnect("Approval failure for %s",
 188                     authctxt->pw->pw_name);
 189         }
 190 #endif
 191 #endif
 192         /* setup the channel layer */
 193         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 194                 channel_permit_all_opens();
 195
 196         if (compat20)
 197                 do_authenticated2(authctxt);
 198         else
 199                 do_authenticated1(authctxt);
 200 }
 201
 202 /*
 203  * Remove local Xauthority file.
 204  */
 205 void
 206 xauthfile_cleanup_proc(void *ignore)
 207 {
 208         debug("xauthfile_cleanup_proc called");
 209
 210         if (xauthfile != NULL) {
 211                 char *p;
 212                 unlink(xauthfile);
 213                 p = strrchr(xauthfile, '/');
 214                 if (p != NULL) {
 215                         *p = '\0';
 216                         rmdir(xauthfile);
 217                 }
 218                 xfree(xauthfile);
 219                 xauthfile = NULL;
 220         }
 221 }
 222
 223 /*
 224  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 225  * dropped connection).
 226  */
 227 void
 228 pty_cleanup_proc(void *session)
 229 {
 230         Session *s=session;
 231         if (s == NULL)
 232                 fatal("pty_cleanup_proc: no session");
 233         debug("pty_cleanup_proc: %s", s->tty);
 234
 235         if (s->pid != 0) {
 236                 /* Record that the user has logged out. */
 237                 record_logout(s->pid, s->tty);
 238         }
 239
 240         /* Release the pseudo-tty. */
 241         pty_release(s->tty);
 242 }
 243
 244 /*
 245  * Prepares for an interactive session.  This is called after the user has
 246  * been successfully authenticated.  During this message exchange, pseudo
 247  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 248  * are requested, etc.
 249  */
 250 void
 251 do_authenticated1(Authctxt *authctxt)
 252 {
 253         Session *s;
 254         char *command;
 255         int success, type, fd, n_bytes, plen, screen_flag, have_pty = 0;
 256         int compression_level = 0, enable_compression_after_reply = 0;
 257         u_int proto_len, data_len, dlen;
 258
 259         s = session_new();
 260         s->pw = authctxt->pw;
 261
 262         /*
 263          * We stay in this loop until the client requests to execute a shell
 264          * or a command.
 265          */
 266         for (;;) {
 267                 success = 0;
 268
 269                 /* Get a packet from the client. */
 270                 type = packet_read(&plen);
 271
 272                 /* Process the packet. */
 273                 switch (type) {
 274                 case SSH_CMSG_REQUEST_COMPRESSION:
 275                         packet_integrity_check(plen, 4, type);
 276                         compression_level = packet_get_int();
 277                         if (compression_level < 1 || compression_level > 9) {
 278                                 packet_send_debug("Received illegal compression level %d.",
 279                                      compression_level);
 280                                 break;
 281                         }
 282                         /* Enable compression after we have responded with SUCCESS. */
 283                         enable_compression_after_reply = 1;
 284                         success = 1;
 285                         break;
 286
 287                 case SSH_CMSG_REQUEST_PTY:
 288                         if (no_pty_flag) {
 289                                 debug("Allocating a pty not permitted for this authentication.");
 290                                 break;
 291                         }
 292                         if (have_pty)
 293                                 packet_disconnect("Protocol error: you already have a pty.");
 294
 295                         debug("Allocating pty.");
 296
 297                         /* Allocate a pty and open it. */
 298                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 299                             sizeof(s->tty))) {
 300                                 error("Failed to allocate pty.");
 301                                 break;
 302                         }
 303                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 304                         pty_setowner(s->pw, s->tty);
 305
 306                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 307                         s->term = packet_get_string(&dlen);
 308                         packet_integrity_check(dlen, strlen(s->term), type);
 309                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 310                         /* Remaining bytes */
 311                         n_bytes = plen - (4 + dlen + 4 * 4);
 312
 313                         if (strcmp(s->term, "") == 0) {
 314                                 xfree(s->term);
 315                                 s->term = NULL;
 316                         }
 317                         /* Get window size from the packet. */
 318                         s->row = packet_get_int();
 319                         s->col = packet_get_int();
 320                         s->xpixel = packet_get_int();
 321                         s->ypixel = packet_get_int();
 322                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 323
 324                         /* Get tty modes from the packet. */
 325                         tty_parse_modes(s->ttyfd, &n_bytes);
 326                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 327
 328                         session_proctitle(s);
 329
 330                         /* Indicate that we now have a pty. */
 331                         success = 1;
 332                         have_pty = 1;
 333                         break;
 334
 335                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 336                         if (!options.x11_forwarding) {
 337                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 338                                 break;
 339                         }
 340                         if (!options.xauth_location) {
 341                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 342                                 break;
 343                         }
 344                         if (no_x11_forwarding_flag) {
 345                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 346                                 break;
 347                         }
 348                         debug("Received request for X11 forwarding with auth spoofing.");
 349                         if (s->display != NULL)
 350                                 packet_disconnect("Protocol error: X11 display already set.");
 351
 352                         s->auth_proto = packet_get_string(&proto_len);
 353                         s->auth_data = packet_get_string(&data_len);
 354
 355                         screen_flag = packet_get_protocol_flags() &
 356                             SSH_PROTOFLAG_SCREEN_NUMBER;
 357                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 358
 359                         if (packet_remaining() == 4) {
 360                                 if (!screen_flag)
 361                                         debug2("Buggy client: "
 362                                             "X11 screen flag missing");
 363                                 packet_integrity_check(plen,
 364                                     4 + proto_len + 4 + data_len + 4, type);
 365                                 s->screen = packet_get_int();
 366                         } else {
 367                                 packet_integrity_check(plen,
 368                                     4 + proto_len + 4 + data_len, type);
 369                                 s->screen = 0;
 370                         }
 371                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 372
 373                         if (s->display == NULL)
 374                                 break;
 375
 376                         /* Setup to always have a local .Xauthority. */
 377                         xauthfile = xmalloc(MAXPATHLEN);
 378                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 379                         temporarily_use_uid(s->pw);
 380                         if (mkdtemp(xauthfile) == NULL) {
 381                                 restore_uid();
 382                                 error("private X11 dir: mkdtemp %s failed: %s",
 383                                     xauthfile, strerror(errno));
 384                                 xfree(xauthfile);
 385                                 xauthfile = NULL;
 386                                 /* XXXX remove listening channels */
 387                                 break;
 388                         }
 389                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 390                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 391                         if (fd >= 0)
 392                                 close(fd);
 393                         restore_uid();
 394                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 395                         success = 1;
 396                         break;
 397
 398                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 399                         if (no_agent_forwarding_flag || compat13) {
 400                                 debug("Authentication agent forwarding not permitted for this authentication.");
 401                                 break;
 402                         }
 403                         debug("Received authentication agent forwarding request.");
 404                         success = auth_input_request_forwarding(s->pw);
 405                         break;
 406
 407                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 408                         if (no_port_forwarding_flag) {
 409                                 debug("Port forwarding not permitted for this authentication.");
 410                                 break;
 411                         }
 412                         if (!options.allow_tcp_forwarding) {
 413                                 debug("Port forwarding not permitted.");
 414                                 break;
 415                         }
 416                         debug("Received TCP/IP port forwarding request.");
 417                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 418                         success = 1;
 419                         break;
 420
 421                 case SSH_CMSG_MAX_PACKET_SIZE:
 422                         if (packet_set_maxsize(packet_get_int()) > 0)
 423                                 success = 1;
 424                         break;
 425
 426                 case SSH_CMSG_EXEC_SHELL:
 427                 case SSH_CMSG_EXEC_CMD:
 428                         if (type == SSH_CMSG_EXEC_CMD) {
 429                                 command = packet_get_string(&dlen);
 430                                 debug("Exec command '%.500s'", command);
 431                                 packet_integrity_check(plen, 4 + dlen, type);
 432                         } else {
 433                                 command = NULL;
 434                                 packet_integrity_check(plen, 0, type);
 435                         }
 436                         if (forced_command != NULL) {
 437                                 original_command = command;
 438                                 command = forced_command;
 439                                 debug("Forced command '%.500s'", forced_command);
 440                         }
 441                         if (have_pty)
 442                                 do_exec_pty(s, command);
 443                         else
 444                                 do_exec_no_pty(s, command);
 445
 446                         if (command != NULL)
 447                                 xfree(command);
 448                         /* Cleanup user's local Xauthority file. */
 449                         if (xauthfile)
 450                                 xauthfile_cleanup_proc(NULL);
 451                         return;
 452
 453                 default:
 454                         /*
 455                          * Any unknown messages in this phase are ignored,
 456                          * and a failure message is returned.
 457                          */
 458                         log("Unknown packet type received after authentication: %d", type);
 459                 }
 460                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 461                 packet_send();
 462                 packet_write_wait();
 463
 464                 /* Enable compression now that we have replied if appropriate. */
 465                 if (enable_compression_after_reply) {
 466                         enable_compression_after_reply = 0;
 467                         packet_start_compression(compression_level);
 468                 }
 469         }
 470 }
 471
 472 /*
 473  * This is called to fork and execute a command when we have no tty.  This
 474  * will call do_child from the child, and server_loop from the parent after
 475  * setting up file descriptors and such.
 476  */
 477 void
 478 do_exec_no_pty(Session *s, const char *command)
 479 {
 480         int pid;
 481
 482 #ifdef USE_PIPES
 483         int pin[2], pout[2], perr[2];
 484         /* Allocate pipes for communicating with the program. */
 485         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 486                 packet_disconnect("Could not create pipes: %.100s",
 487                                   strerror(errno));
 488 #else /* USE_PIPES */
 489         int inout[2], err[2];
 490         /* Uses socket pairs to communicate with the program. */
 491         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 492             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 493                 packet_disconnect("Could not create socket pairs: %.100s",
 494                                   strerror(errno));
 495 #endif /* USE_PIPES */
 496         if (s == NULL)
 497                 fatal("do_exec_no_pty: no session");
 498
 499         session_proctitle(s);
 500
 501 #if defined(USE_PAM)
 502         do_pam_setcred(1);
 503 #endif /* USE_PAM */
 504
 505         /* Fork the child. */
 506         if ((pid = fork()) == 0) {
 507                 /* Child.  Reinitialize the log since the pid has changed. */
 508                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 509
 510                 /*
 511                  * Create a new session and process group since the 4.4BSD
 512                  * setlogin() affects the entire process group.
 513                  */
 514                 if (setsid() < 0)
 515                         error("setsid failed: %.100s", strerror(errno));
 516
 517 #ifdef USE_PIPES
 518                 /*
 519                  * Redirect stdin.  We close the parent side of the socket
 520                  * pair, and make the child side the standard input.
 521                  */
 522                 close(pin[1]);
 523                 if (dup2(pin[0], 0) < 0)
 524                         perror("dup2 stdin");
 525                 close(pin[0]);
 526
 527                 /* Redirect stdout. */
 528                 close(pout[0]);
 529                 if (dup2(pout[1], 1) < 0)
 530                         perror("dup2 stdout");
 531                 close(pout[1]);
 532
 533                 /* Redirect stderr. */
 534                 close(perr[0]);
 535                 if (dup2(perr[1], 2) < 0)
 536                         perror("dup2 stderr");
 537                 close(perr[1]);
 538 #else /* USE_PIPES */
 539                 /*
 540                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 541                  * use the same socket, as some programs (particularly rdist)
 542                  * seem to depend on it.
 543                  */
 544                 close(inout[1]);
 545                 close(err[1]);
 546                 if (dup2(inout[0], 0) < 0)      /* stdin */
 547                         perror("dup2 stdin");
 548                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 549                         perror("dup2 stdout");
 550                 if (dup2(err[0], 2) < 0)        /* stderr */
 551                         perror("dup2 stderr");
 552 #endif /* USE_PIPES */
 553
 554                 /* Do processing for the child (exec command etc). */
 555                 do_child(s, command);
 556                 /* NOTREACHED */
 557         }
 558 #ifdef HAVE_CYGWIN
 559         if (is_winnt)
 560                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 561 #endif
 562         if (pid < 0)
 563                 packet_disconnect("fork failed: %.100s", strerror(errno));
 564         s->pid = pid;
 565         /* Set interactive/non-interactive mode. */
 566         packet_set_interactive(s->display != NULL);
 567 #ifdef USE_PIPES
 568         /* We are the parent.  Close the child sides of the pipes. */
 569         close(pin[0]);
 570         close(pout[1]);
 571         close(perr[1]);
 572
 573         if (compat20) {
 574                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 575         } else {
 576                 /* Enter the interactive session. */
 577                 server_loop(pid, pin[1], pout[0], perr[0]);
 578                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 579         }
 580 #else /* USE_PIPES */
 581         /* We are the parent.  Close the child sides of the socket pairs. */
 582         close(inout[0]);
 583         close(err[0]);
 584
 585         /*
 586          * Enter the interactive session.  Note: server_loop must be able to
 587          * handle the case that fdin and fdout are the same.
 588          */
 589         if (compat20) {
 590                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 591         } else {
 592                 server_loop(pid, inout[1], inout[1], err[1]);
 593                 /* server_loop has closed inout[1] and err[1]. */
 594         }
 595 #endif /* USE_PIPES */
 596 }
 597
 598 /*
 599  * This is called to fork and execute a command when we have a tty.  This
 600  * will call do_child from the child, and server_loop from the parent after
 601  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 602  * lastlog, and other such operations.
 603  */
 604 void
 605 do_exec_pty(Session *s, const char *command)
 606 {
 607         int fdout, ptyfd, ttyfd, ptymaster;
 608         pid_t pid;
 609
 610         if (s == NULL)
 611                 fatal("do_exec_pty: no session");
 612         ptyfd = s->ptyfd;
 613         ttyfd = s->ttyfd;
 614
 615 #if defined(USE_PAM)
 616         do_pam_session(s->pw->pw_name, s->tty);
 617         do_pam_setcred(1);
 618 #endif
 619
 620         /* Fork the child. */
 621         if ((pid = fork()) == 0) {
 622                 /* Child.  Reinitialize the log because the pid has changed. */
 623                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 624
 625                 /* Close the master side of the pseudo tty. */
 626                 close(ptyfd);
 627
 628                 /* Make the pseudo tty our controlling tty. */
 629                 pty_make_controlling_tty(&ttyfd, s->tty);
 630
 631                 /* Redirect stdin from the pseudo tty. */
 632                 if (dup2(ttyfd, fileno(stdin)) < 0)
 633                         error("dup2 stdin failed: %.100s", strerror(errno));
 634
 635                 /* Redirect stdout to the pseudo tty. */
 636                 if (dup2(ttyfd, fileno(stdout)) < 0)
 637                         error("dup2 stdin failed: %.100s", strerror(errno));
 638
 639                 /* Redirect stderr to the pseudo tty. */
 640                 if (dup2(ttyfd, fileno(stderr)) < 0)
 641                         error("dup2 stdin failed: %.100s", strerror(errno));
 642
 643                 /* Close the extra descriptor for the pseudo tty. */
 644                 close(ttyfd);
 645
 646                 /* record login, etc. similar to login(1) */
 647 #ifndef HAVE_OSF_SIA
 648                 if (!(options.use_login && command == NULL))
 649                         do_login(s, command);
 650 # ifdef LOGIN_NEEDS_UTMPX
 651                 else
 652                         do_pre_login(s);
 653 # endif
 654 #endif
 655
 656                 /* Do common processing for the child, such as execing the command. */
 657                 do_child(s, command);
 658                 /* NOTREACHED */
 659         }
 660 #ifdef HAVE_CYGWIN
 661         if (is_winnt)
 662                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 663 #endif
 664         if (pid < 0)
 665                 packet_disconnect("fork failed: %.100s", strerror(errno));
 666         s->pid = pid;
 667
 668         /* Parent.  Close the slave side of the pseudo tty. */
 669         close(ttyfd);
 670
 671         /*
 672          * Create another descriptor of the pty master side for use as the
 673          * standard input.  We could use the original descriptor, but this
 674          * simplifies code in server_loop.  The descriptor is bidirectional.
 675          */
 676         fdout = dup(ptyfd);
 677         if (fdout < 0)
 678                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 679
 680         /* we keep a reference to the pty master */
 681         ptymaster = dup(ptyfd);
 682         if (ptymaster < 0)
 683                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 684         s->ptymaster = ptymaster;
 685
 686         /* Enter interactive session. */
 687         packet_set_interactive(1);
 688         if (compat20) {
 689                 session_set_fds(s, ptyfd, fdout, -1);
 690         } else {
 691                 server_loop(pid, ptyfd, fdout, -1);
 692                 /* server_loop _has_ closed ptyfd and fdout. */
 693                 session_pty_cleanup(s);
 694         }
 695 }
 696
 697 #ifdef LOGIN_NEEDS_UTMPX
 698 void
 699 do_pre_login(Session *s)
 700 {
 701         socklen_t fromlen;
 702         struct sockaddr_storage from;
 703         pid_t pid = getpid();
 704
 705         /*
 706          * Get IP address of client. If the connection is not a socket, let
 707          * the address be 0.0.0.0.
 708          */
 709         memset(&from, 0, sizeof(from));
 710         if (packet_connection_is_on_socket()) {
 711                 fromlen = sizeof(from);
 712                 if (getpeername(packet_get_connection_in(),
 713                      (struct sockaddr *) & from, &fromlen) < 0) {
 714                         debug("getpeername: %.100s", strerror(errno));
 715                         fatal_cleanup();
 716                 }
 717         }
 718
 719         record_utmp_only(pid, s->tty, s->pw->pw_name,
 720             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 721             (struct sockaddr *)&from);
 722 }
 723 #endif
 724
 725 /* administrative, login(1)-like work */
 726 void
 727 do_login(Session *s, const char *command)
 728 {
 729         char *time_string;
 730         char hostname[MAXHOSTNAMELEN];
 731         socklen_t fromlen;
 732         struct sockaddr_storage from;
 733         time_t last_login_time;
 734         struct passwd * pw = s->pw;
 735         pid_t pid = getpid();
 736
 737         /*
 738          * Get IP address of client. If the connection is not a socket, let
 739          * the address be 0.0.0.0.
 740          */
 741         memset(&from, 0, sizeof(from));
 742         if (packet_connection_is_on_socket()) {
 743                 fromlen = sizeof(from);
 744                 if (getpeername(packet_get_connection_in(),
 745                      (struct sockaddr *) & from, &fromlen) < 0) {
 746                         debug("getpeername: %.100s", strerror(errno));
 747                         fatal_cleanup();
 748                 }
 749         }
 750
 751         /* Get the time and hostname when the user last logged in. */
 752         if (options.print_lastlog) {
 753                 hostname[0] = '\0';
 754                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 755                     hostname, sizeof(hostname));
 756         }
 757
 758         /* Record that there was a login on that tty from the remote host. */
 759         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 760             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 761             (struct sockaddr *)&from);
 762
 763 #ifdef USE_PAM
 764         /*
 765          * If password change is needed, do it now.
 766          * This needs to occur before the ~/.hushlogin check.
 767          */
 768         if (is_pam_password_change_required()) {
 769                 print_pam_messages();
 770                 do_pam_chauthtok();
 771         }
 772 #endif
 773
 774         if (check_quietlogin(s, command))
 775                 return;
 776
 777 #ifdef USE_PAM
 778         if (!is_pam_password_change_required())
 779                 print_pam_messages();
 780 #endif /* USE_PAM */
 781 #ifdef WITH_AIXAUTHENTICATE
 782         if (aixloginmsg && *aixloginmsg)
 783                 printf("%s\n", aixloginmsg);
 784 #endif /* WITH_AIXAUTHENTICATE */
 785
 786         if (options.print_lastlog && last_login_time != 0) {
 787                 time_string = ctime(&last_login_time);
 788                 if (strchr(time_string, '\n'))
 789                         *strchr(time_string, '\n') = 0;
 790                 if (strcmp(hostname, "") == 0)
 791                         printf("Last login: %s\r\n", time_string);
 792                 else
 793                         printf("Last login: %s from %s\r\n", time_string, hostname);
 794         }
 795
 796         do_motd();
 797 }
 798
 799 /*
 800  * Display the message of the day.
 801  */
 802 void
 803 do_motd(void)
 804 {
 805         FILE *f;
 806         char buf[256];
 807
 808         if (options.print_motd) {
 809 #ifdef HAVE_LOGIN_CAP
 810                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 811                     "/etc/motd"), "r");
 812 #else
 813                 f = fopen("/etc/motd", "r");
 814 #endif
 815                 if (f) {
 816                         while (fgets(buf, sizeof(buf), f))
 817                                 fputs(buf, stdout);
 818                         fclose(f);
 819                 }
 820         }
 821 }
 822
 823
 824 /*
 825  * Check for quiet login, either .hushlogin or command given.
 826  */
 827 int
 828 check_quietlogin(Session *s, const char *command)
 829 {
 830         char buf[256];
 831         struct passwd * pw = s->pw;
 832         struct stat st;
 833
 834         /* Return 1 if .hushlogin exists or a command given. */
 835         if (command != NULL)
 836                 return 1;
 837         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 838 #ifdef HAVE_LOGIN_CAP
 839         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 840                 return 1;
 841 #else
 842         if (stat(buf, &st) >= 0)
 843                 return 1;
 844 #endif
 845         return 0;
 846 }
 847
 848 /*
 849  * Sets the value of the given variable in the environment.  If the variable
 850  * already exists, its value is overriden.
 851  */
 852 void
 853 child_set_env(char ***envp, u_int *envsizep, const char *name,
 854               const char *value)
 855 {
 856         u_int i, namelen;
 857         char **env;
 858
 859         /*
 860          * Find the slot where the value should be stored.  If the variable
 861          * already exists, we reuse the slot; otherwise we append a new slot
 862          * at the end of the array, expanding if necessary.
 863          */
 864         env = *envp;
 865         namelen = strlen(name);
 866         for (i = 0; env[i]; i++)
 867                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 868                         break;
 869         if (env[i]) {
 870                 /* Reuse the slot. */
 871                 xfree(env[i]);
 872         } else {
 873                 /* New variable.  Expand if necessary. */
 874                 if (i >= (*envsizep) - 1) {
 875                         (*envsizep) += 50;
 876                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 877                 }
 878                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 879                 env[i + 1] = NULL;
 880         }
 881
 882         /* Allocate space and format the variable in the appropriate slot. */
 883         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 884         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 885 }
 886
 887 /*
 888  * Reads environment variables from the given file and adds/overrides them
 889  * into the environment.  If the file does not exist, this does nothing.
 890  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 891  * and assignments of the form name=value.  No other forms are allowed.
 892  */
 893 void
 894 read_environment_file(char ***env, u_int *envsize,
 895                       const char *filename)
 896 {
 897         FILE *f;
 898         char buf[4096];
 899         char *cp, *value;
 900
 901         f = fopen(filename, "r");
 902         if (!f)
 903                 return;
 904
 905         while (fgets(buf, sizeof(buf), f)) {
 906                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 907                         ;
 908                 if (!*cp || *cp == '#' || *cp == '\n')
 909                         continue;
 910                 if (strchr(cp, '\n'))
 911                         *strchr(cp, '\n') = '\0';
 912                 value = strchr(cp, '=');
 913                 if (value == NULL) {
 914                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 915                         continue;
 916                 }
 917                 /*
 918                  * Replace the equals sign by nul, and advance value to
 919                  * the value string.
 920                  */
 921                 *value = '\0';
 922                 value++;
 923                 child_set_env(env, envsize, cp, value);
 924         }
 925         fclose(f);
 926 }
 927
 928 #ifdef USE_PAM
 929 /*
 930  * Sets any environment variables which have been specified by PAM
 931  */
 932 void do_pam_environment(char ***env, int *envsize)
 933 {
 934         char *equals, var_name[512], var_val[512];
 935         char **pam_env;
 936         int i;
 937
 938         if ((pam_env = fetch_pam_environment()) == NULL)
 939                 return;
 940
 941         for(i = 0; pam_env[i] != NULL; i++) {
 942                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 943                         continue;
 944
 945                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 946                         memset(var_name, '\0', sizeof(var_name));
 947                         memset(var_val, '\0', sizeof(var_val));
 948
 949                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 950                         strcpy(var_val, equals + 1);
 951
 952                         debug3("PAM environment: %s=%s", var_name, var_val);
 953
 954                         child_set_env(env, envsize, var_name, var_val);
 955                 }
 956         }
 957 }
 958 #endif /* USE_PAM */
 959
 960 #ifdef HAVE_CYGWIN
 961 void copy_environment(char ***env, int *envsize)
 962 {
 963         char *equals, var_name[512], var_val[512];
 964         int i;
 965
 966         for(i = 0; environ[i] != NULL; i++) {
 967                 if ((equals = strstr(environ[i], "=")) == NULL)
 968                         continue;
 969
 970                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 971                         memset(var_name, '\0', sizeof(var_name));
 972                         memset(var_val, '\0', sizeof(var_val));
 973
 974                         strncpy(var_name, environ[i], equals - environ[i]);
 975                         strcpy(var_val, equals + 1);
 976
 977                         debug3("Copy environment: %s=%s", var_name, var_val);
 978
 979                         child_set_env(env, envsize, var_name, var_val);
 980                 }
 981         }
 982 }
 983 #endif
 984
 985 #if defined(HAVE_GETUSERATTR)
 986 /*
 987  * AIX-specific login initialisation
 988  */
 989 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 990 {
 991         struct rlimit rlim;
 992         int slim, hlim;
 993
 994         getrlimit(resource, &rlim);
 995
 996         slim = 0;
 997         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 998                 if (slim < 0) {
 999                         rlim.rlim_cur = RLIM_INFINITY;
1000                 } else if (slim != 0) {
1001                         /* See the wackiness below */
1002                         if (rlim.rlim_cur == slim * mult)
1003                                 slim = 0;
1004                         else
1005                                 rlim.rlim_cur = slim * mult;
1006                 }
1007         }
1008
1009         hlim = 0;
1010         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
1011                 if (hlim < 0) {
1012                         rlim.rlim_max = RLIM_INFINITY;
1013                 } else if (hlim != 0) {
1014                         rlim.rlim_max = hlim * mult;
1015                 }
1016         }
1017
1018         /*
1019          * XXX For cpu and fsize the soft limit is set to the hard limit
1020          * if the hard limit is left at its default value and the soft limit
1021          * is changed from its default value, either by requesting it
1022          * (slim == 0) or by setting it to the current default.  At least
1023          * that's how rlogind does it.  If you're confused you're not alone.
1024          * Bug or feature? AIX 4.3.1.2
1025          */
1026         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
1027             && hlim == 0 && slim != 0)
1028                 rlim.rlim_max = rlim.rlim_cur;
1029         /* A specified hard limit limits the soft limit */
1030         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
1031                 rlim.rlim_cur = rlim.rlim_max;
1032         /* A soft limit can increase a hard limit */
1033         else if (rlim.rlim_cur > rlim.rlim_max)
1034                 rlim.rlim_max = rlim.rlim_cur;
1035
1036         if (setrlimit(resource, &rlim) != 0)
1037                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
1038 }
1039
1040 void set_limits_from_userattr(char *user)
1041 {
1042         int mask;
1043         char buf[16];
1044
1045         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
1046         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
1047         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
1048         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
1049         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
1050         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
1051 #if defined(S_UNOFILE)
1052         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1053 #endif
1054
1055         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1056                 /* Convert decimal to octal */
1057                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1058                 if (sscanf(buf, "%o", &mask) == 1)
1059                         umask(mask);
1060         }
1061 }
1062 #endif /* defined(HAVE_GETUSERATTR) */
1063
1064 /*
1065  * Performs common processing for the child, such as setting up the
1066  * environment, closing extra file descriptors, setting the user and group
1067  * ids, and executing the command or shell.
1068  */
1069 void
1070 do_child(Session *s, const char *command)
1071 {
1072         const char *shell, *hostname = NULL, *cp = NULL;
1073         struct passwd * pw = s->pw;
1074         char buf[256];
1075         char cmd[1024];
1076         FILE *f = NULL;
1077         u_int envsize, i;
1078         char **env;
1079         extern char **environ;
1080         struct stat st;
1081         char *argv[10];
1082         int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1083 #ifdef WITH_IRIX_PROJECT
1084         prid_t projid;
1085 #endif /* WITH_IRIX_PROJECT */
1086 #ifdef WITH_IRIX_JOBS
1087         jid_t jid = 0;
1088 #else
1089 #ifdef WITH_IRIX_ARRAY
1090         int jid = 0;
1091 #endif /* WITH_IRIX_ARRAY */
1092 #endif /* WITH_IRIX_JOBS */
1093
1094         /* remove hostkey from the child's memory */
1095         destroy_sensitive_data();
1096
1097         /* login(1) is only called if we execute the login shell */
1098         if (options.use_login && command != NULL)
1099                 options.use_login = 0;
1100
1101 #if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
1102         if (!options.use_login) {
1103 # ifdef HAVE_LOGIN_CAP
1104                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1105                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1106                             _PATH_NOLOGIN), "r");
1107 # else /* HAVE_LOGIN_CAP */
1108                 if (pw->pw_uid)
1109                         f = fopen(_PATH_NOLOGIN, "r");
1110 # endif /* HAVE_LOGIN_CAP */
1111                 if (f) {
1112                         /* /etc/nologin exists.  Print its contents and exit. */
1113                         while (fgets(buf, sizeof(buf), f))
1114                                 fputs(buf, stderr);
1115                         fclose(f);
1116                         exit(254);
1117                 }
1118         }
1119 #endif /* USE_PAM || HAVE_OSF_SIA */
1120
1121         /* Set login name, uid, gid, and groups. */
1122         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1123            switch, so we let login(1) to this for us. */
1124         if (!options.use_login) {
1125 #ifdef HAVE_OSF_SIA
1126                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1127                 if (!check_quietlogin(s, command))
1128                         do_motd();
1129 #else /* HAVE_OSF_SIA */
1130 #ifdef HAVE_CYGWIN
1131                 if (is_winnt) {
1132 #else
1133                 if (getuid() == 0 || geteuid() == 0) {
1134 #endif
1135 # ifdef HAVE_GETUSERATTR
1136                         set_limits_from_userattr(pw->pw_name);
1137 # endif /* HAVE_GETUSERATTR */
1138 # ifdef HAVE_LOGIN_CAP
1139                         if (setusercontext(lc, pw, pw->pw_uid,
1140                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1141                                 perror("unable to set user context");
1142                                 exit(1);
1143                         }
1144 # else /* HAVE_LOGIN_CAP */
1145 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1146                         /* Sets login uid for accounting */
1147                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1148                                 error("setluid: %s", strerror(errno));
1149 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1150
1151                         if (setlogin(pw->pw_name) < 0)
1152                                 error("setlogin failed: %s", strerror(errno));
1153                         if (setgid(pw->pw_gid) < 0) {
1154                                 perror("setgid");
1155                                 exit(1);
1156                         }
1157                         /* Initialize the group list. */
1158                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1159                                 perror("initgroups");
1160                                 exit(1);
1161                         }
1162                         endgrent();
1163 #  ifdef USE_PAM
1164                         /*
1165                          * PAM credentials may take the form of
1166                          * supplementary groups. These will have been
1167                          * wiped by the above initgroups() call.
1168                          * Reestablish them here.
1169                          */
1170                         do_pam_setcred(0);
1171 #  endif /* USE_PAM */
1172 #  ifdef WITH_IRIX_JOBS
1173                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1174                         if (jid == -1) {
1175                                 fatal("Failed to create job container: %.100s",
1176                                       strerror(errno));
1177                         }
1178 #  endif /* WITH_IRIX_JOBS */
1179 #  ifdef WITH_IRIX_ARRAY
1180                         /* initialize array session */
1181                         if (jid == 0) {
1182                                 if (newarraysess() != 0)
1183                                         fatal("Failed to set up new array session: %.100s",
1184                                               strerror(errno));
1185                         }
1186 #  endif /* WITH_IRIX_ARRAY */
1187 #  ifdef WITH_IRIX_PROJECT
1188                         /* initialize irix project info */
1189                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1190                           debug("Failed to get project id, using projid 0");
1191                           projid = 0;
1192                         }
1193                         if (setprid(projid))
1194                           fatal("Failed to initialize project %d for %s: %.100s",
1195                                 (int)projid, pw->pw_name, strerror(errno));
1196 #  endif /* WITH_IRIX_PROJECT */
1197 #ifdef WITH_IRIX_AUDIT
1198                         if (sysconf(_SC_AUDIT)) {
1199                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1200                                 if (satsetid(pw->pw_uid))
1201                                         debug("error setting satid: %.100s", strerror(errno));
1202                         }
1203 #endif /* WITH_IRIX_AUDIT */
1204
1205 #ifdef _AIX
1206                         /*
1207                          * AIX has a "usrinfo" area where logname and
1208                          * other stuff is stored - a few applications
1209                          * actually use this and die if it's not set
1210                          */
1211                         if (s->ttyfd == -1)
1212                                 s->tty[0] = '\0';
1213                         cp = xmalloc(22 + strlen(s->tty) +
1214                             2 * strlen(pw->pw_name));
1215                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1216                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1217                         if (usrinfo(SETUINFO, cp, i) == -1)
1218                                 fatal("Couldn't set usrinfo: %s",
1219                                     strerror(errno));
1220                         debug3("AIX/UsrInfo: set len %d", i);
1221                         xfree(cp);
1222 #endif
1223
1224                         /* Permanently switch to the desired uid. */
1225                         permanently_set_uid(pw);
1226 # endif /* HAVE_LOGIN_CAP */
1227                 }
1228 #endif /* HAVE_OSF_SIA */
1229
1230 #ifdef HAVE_CYGWIN
1231                 if (is_winnt)
1232 #endif
1233                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1234                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1235         }
1236         /*
1237          * Get the shell from the password data.  An empty shell field is
1238          * legal, and means /bin/sh.
1239          */
1240         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1241 #ifdef HAVE_LOGIN_CAP
1242         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1243 #endif
1244
1245 #ifdef AFS
1246         /* Try to get AFS tokens for the local cell. */
1247         if (k_hasafs()) {
1248                 char cell[64];
1249
1250                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1251                         krb_afslog(cell, 0);
1252
1253                 krb_afslog(0, 0);
1254         }
1255 #endif /* AFS */
1256
1257         /* Initialize the environment. */
1258         envsize = 100;
1259         env = xmalloc(envsize * sizeof(char *));
1260         env[0] = NULL;
1261
1262 #ifdef HAVE_CYGWIN
1263         /*
1264          * The Windows environment contains some setting which are
1265          * important for a running system. They must not be dropped.
1266          */
1267         copy_environment(&env, &envsize);
1268 #endif
1269
1270         if (!options.use_login) {
1271                 /* Set basic environment. */
1272                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1273                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1274                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1275 #ifdef HAVE_LOGIN_CAP
1276                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1277                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1278 #else /* HAVE_LOGIN_CAP */
1279 # ifndef HAVE_CYGWIN
1280                 /*
1281                  * There's no standard path on Windows. The path contains
1282                  * important components pointing to the system directories,
1283                  * needed for loading shared libraries. So the path better
1284                  * remains intact here.
1285                  */
1286                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1287 # endif /* HAVE_CYGWIN */
1288 #endif /* HAVE_LOGIN_CAP */
1289
1290                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1291                          _PATH_MAILDIR, pw->pw_name);
1292                 child_set_env(&env, &envsize, "MAIL", buf);
1293
1294                 /* Normal systems set SHELL by default. */
1295                 child_set_env(&env, &envsize, "SHELL", shell);
1296         }
1297         if (getenv("TZ"))
1298                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1299
1300         /* Set custom environment options from RSA authentication. */
1301         while (custom_environment) {
1302                 struct envstring *ce = custom_environment;
1303                 char *s = ce->s;
1304                 int i;
1305                 for (i = 0; s[i] != '=' && s[i]; i++);
1306                 if (s[i] == '=') {
1307                         s[i] = 0;
1308                         child_set_env(&env, &envsize, s, s + i + 1);
1309                 }
1310                 custom_environment = ce->next;
1311                 xfree(ce->s);
1312                 xfree(ce);
1313         }
1314
1315         snprintf(buf, sizeof buf, "%.50s %d %d",
1316                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1317         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1318
1319         if (s->ttyfd != -1)
1320                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1321         if (s->term)
1322                 child_set_env(&env, &envsize, "TERM", s->term);
1323         if (s->display)
1324                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1325         if (original_command)
1326                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1327                     original_command);
1328
1329 #ifdef _AIX
1330         if ((cp = getenv("AUTHSTATE")) != NULL)
1331                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1332         if ((cp = getenv("KRB5CCNAME")) != NULL)
1333                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1334         read_environment_file(&env, &envsize, "/etc/environment");
1335 #endif
1336
1337 #ifdef KRB4
1338         {
1339                 extern char *ticket;
1340
1341                 if (ticket)
1342                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1343         }
1344 #endif /* KRB4 */
1345
1346 #ifdef USE_PAM
1347         /* Pull in any environment variables that may have been set by PAM. */
1348         do_pam_environment(&env, &envsize);
1349 #endif /* USE_PAM */
1350
1351         if (xauthfile)
1352                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1353         if (auth_get_socket_name() != NULL)
1354                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1355                               auth_get_socket_name());
1356
1357         /* read $HOME/.ssh/environment. */
1358         if (!options.use_login) {
1359                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1360                     pw->pw_dir);
1361                 read_environment_file(&env, &envsize, buf);
1362         }
1363         if (debug_flag) {
1364                 /* dump the environment */
1365                 fprintf(stderr, "Environment:\n");
1366                 for (i = 0; env[i]; i++)
1367                         fprintf(stderr, "  %.200s\n", env[i]);
1368         }
1369         /* we have to stash the hostname before we close our socket. */
1370         if (options.use_login)
1371                 hostname = get_remote_name_or_ip(utmp_len,
1372                     options.reverse_mapping_check);
1373         /*
1374          * Close the connection descriptors; note that this is the child, and
1375          * the server will still have the socket open, and it is important
1376          * that we do not shutdown it.  Note that the descriptors cannot be
1377          * closed before building the environment, as we call
1378          * get_remote_ipaddr there.
1379          */
1380         if (packet_get_connection_in() == packet_get_connection_out())
1381                 close(packet_get_connection_in());
1382         else {
1383                 close(packet_get_connection_in());
1384                 close(packet_get_connection_out());
1385         }
1386         /*
1387          * Close all descriptors related to channels.  They will still remain
1388          * open in the parent.
1389          */
1390         /* XXX better use close-on-exec? -markus */
1391         channel_close_all();
1392
1393         /*
1394          * Close any extra file descriptors.  Note that there may still be
1395          * descriptors left by system functions.  They will be closed later.
1396          */
1397         endpwent();
1398
1399         /*
1400          * Close any extra open file descriptors so that we don\'t have them
1401          * hanging around in clients.  Note that we want to do this after
1402          * initgroups, because at least on Solaris 2.3 it leaves file
1403          * descriptors open.
1404          */
1405         for (i = 3; i < 64; i++)
1406                 close(i);
1407
1408         /* Change current directory to the user\'s home directory. */
1409         if (chdir(pw->pw_dir) < 0) {
1410                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1411                         pw->pw_dir, strerror(errno));
1412 #ifdef HAVE_LOGIN_CAP
1413                 if (login_getcapbool(lc, "requirehome", 0))
1414                         exit(1);
1415 #endif
1416         }
1417
1418         /*
1419          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1420          * xauth are run in the proper environment.
1421          */
1422         environ = env;
1423
1424         /*
1425          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1426          * in this order).
1427          */
1428         if (!options.use_login) {
1429                 /* ignore _PATH_SSH_USER_RC for subsystems */
1430                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1431                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1432                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1433                         if (debug_flag)
1434                                 fprintf(stderr, "Running %s\n", cmd);
1435                         f = popen(cmd, "w");
1436                         if (f) {
1437                                 if (do_xauth)
1438                                         fprintf(f, "%s %s\n", s->auth_proto,
1439                                             s->auth_data);
1440                                 pclose(f);
1441                         } else
1442                                 fprintf(stderr, "Could not run %s\n",
1443                                     _PATH_SSH_USER_RC);
1444                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1445                         if (debug_flag)
1446                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1447                                     _PATH_SSH_SYSTEM_RC);
1448                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1449                         if (f) {
1450                                 if (do_xauth)
1451                                         fprintf(f, "%s %s\n", s->auth_proto,
1452                                             s->auth_data);
1453                                 pclose(f);
1454                         } else
1455                                 fprintf(stderr, "Could not run %s\n",
1456                                     _PATH_SSH_SYSTEM_RC);
1457                 } else if (do_xauth && options.xauth_location != NULL) {
1458                         /* Add authority data to .Xauthority if appropriate. */
1459                         char *screen = strchr(s->display, ':');
1460
1461                         if (debug_flag) {
1462                                 fprintf(stderr,
1463                                     "Running %.100s add "
1464                                     "%.100s %.100s %.100s\n",
1465                                     options.xauth_location, s->display,
1466                                     s->auth_proto, s->auth_data);
1467                                 if (screen != NULL)
1468                                         fprintf(stderr,
1469                                             "Adding %.*s/unix%s %s %s\n",
1470                                             (int)(screen - s->display),
1471                                             s->display, screen,
1472                                             s->auth_proto, s->auth_data);
1473                         }
1474                         snprintf(cmd, sizeof cmd, "%s -q -",
1475                             options.xauth_location);
1476                         f = popen(cmd, "w");
1477                         if (f) {
1478                                 fprintf(f, "add %s %s %s\n", s->display,
1479                                     s->auth_proto, s->auth_data);
1480                                 if (screen != NULL)
1481                                         fprintf(f, "add %.*s/unix%s %s %s\n",
1482                                             (int)(screen - s->display),
1483                                             s->display, screen,
1484                                             s->auth_proto,
1485                                             s->auth_data);
1486                                 pclose(f);
1487                         } else {
1488                                 fprintf(stderr, "Could not run %s\n",
1489                                     cmd);
1490                         }
1491                 }
1492                 /* Get the last component of the shell name. */
1493                 cp = strrchr(shell, '/');
1494                 if (cp)
1495                         cp++;
1496                 else
1497                         cp = shell;
1498         }
1499
1500         /* restore SIGPIPE for child */
1501         signal(SIGPIPE,  SIG_DFL);
1502
1503         /*
1504          * If we have no command, execute the shell.  In this case, the shell
1505          * name to be passed in argv[0] is preceded by '-' to indicate that
1506          * this is a login shell.
1507          */
1508         if (!command) {
1509                 if (!options.use_login) {
1510                         char buf[256];
1511
1512                         /*
1513                          * Check for mail if we have a tty and it was enabled
1514                          * in server options.
1515                          */
1516                         if (s->ttyfd != -1 && options.check_mail) {
1517                                 char *mailbox;
1518                                 struct stat mailstat;
1519
1520                                 mailbox = getenv("MAIL");
1521                                 if (mailbox != NULL) {
1522                                         if (stat(mailbox, &mailstat) != 0 ||
1523                                             mailstat.st_size == 0)
1524                                                 printf("No mail.\n");
1525                                         else if (mailstat.st_mtime < mailstat.st_atime)
1526                                                 printf("You have mail.\n");
1527                                         else
1528                                                 printf("You have new mail.\n");
1529                                 }
1530                         }
1531                         /* Start the shell.  Set initial character to '-'. */
1532                         buf[0] = '-';
1533                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1534                         buf[sizeof(buf) - 1] = 0;
1535
1536                         /* Execute the shell. */
1537                         argv[0] = buf;
1538                         argv[1] = NULL;
1539                         execve(shell, argv, env);
1540
1541                         /* Executing the shell failed. */
1542                         perror(shell);
1543                         exit(1);
1544
1545                 } else {
1546                         /* Launch login(1). */
1547
1548                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1549 #ifdef LOGIN_NEEDS_TERM
1550                              s->term? s->term : "unknown",
1551 #endif
1552                              "-p", "-f", "--", pw->pw_name, NULL);
1553
1554                         /* Login couldn't be executed, die. */
1555
1556                         perror("login");
1557                         exit(1);
1558                 }
1559         }
1560         /*
1561          * Execute the command using the user's shell.  This uses the -c
1562          * option to execute the command.
1563          */
1564         argv[0] = (char *) cp;
1565         argv[1] = "-c";
1566         argv[2] = (char *) command;
1567         argv[3] = NULL;
1568         execve(shell, argv, env);
1569         perror(shell);
1570         exit(1);
1571 }
1572
1573 Session *
1574 session_new(void)
1575 {
1576         int i;
1577         static int did_init = 0;
1578         if (!did_init) {
1579                 debug("session_new: init");
1580                 for(i = 0; i < MAX_SESSIONS; i++) {
1581                         sessions[i].used = 0;
1582                         sessions[i].self = i;
1583                 }
1584                 did_init = 1;
1585         }
1586         for(i = 0; i < MAX_SESSIONS; i++) {
1587                 Session *s = &sessions[i];
1588                 if (! s->used) {
1589                         memset(s, 0, sizeof(*s));
1590                         s->chanid = -1;
1591                         s->ptyfd = -1;
1592                         s->ttyfd = -1;
1593                         s->used = 1;
1594                         debug("session_new: session %d", i);
1595                         return s;
1596                 }
1597         }
1598         return NULL;
1599 }
1600
1601 void
1602 session_dump(void)
1603 {
1604         int i;
1605         for(i = 0; i < MAX_SESSIONS; i++) {
1606                 Session *s = &sessions[i];
1607                 debug("dump: used %d session %d %p channel %d pid %d",
1608                     s->used,
1609                     s->self,
1610                     s,
1611                     s->chanid,
1612                     s->pid);
1613         }
1614 }
1615
1616 int
1617 session_open(int chanid)
1618 {
1619         Session *s = session_new();
1620         debug("session_open: channel %d", chanid);
1621         if (s == NULL) {
1622                 error("no more sessions");
1623                 return 0;
1624         }
1625         s->pw = auth_get_user();
1626         if (s->pw == NULL)
1627                 fatal("no user for session %d", s->self);
1628         debug("session_open: session %d: link with channel %d", s->self, chanid);
1629         s->chanid = chanid;
1630         return 1;
1631 }
1632
1633 Session *
1634 session_by_channel(int id)
1635 {
1636         int i;
1637         for(i = 0; i < MAX_SESSIONS; i++) {
1638                 Session *s = &sessions[i];
1639                 if (s->used && s->chanid == id) {
1640                         debug("session_by_channel: session %d channel %d", i, id);
1641                         return s;
1642                 }
1643         }
1644         debug("session_by_channel: unknown channel %d", id);
1645         session_dump();
1646         return NULL;
1647 }
1648
1649 Session *
1650 session_by_pid(pid_t pid)
1651 {
1652         int i;
1653         debug("session_by_pid: pid %d", pid);
1654         for(i = 0; i < MAX_SESSIONS; i++) {
1655                 Session *s = &sessions[i];
1656                 if (s->used && s->pid == pid)
1657                         return s;
1658         }
1659         error("session_by_pid: unknown pid %d", pid);
1660         session_dump();
1661         return NULL;
1662 }
1663
1664 int
1665 session_window_change_req(Session *s)
1666 {
1667         s->col = packet_get_int();
1668         s->row = packet_get_int();
1669         s->xpixel = packet_get_int();
1670         s->ypixel = packet_get_int();
1671         packet_done();
1672         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1673         return 1;
1674 }
1675
1676 int
1677 session_pty_req(Session *s)
1678 {
1679         u_int len;
1680         int n_bytes;
1681
1682         if (no_pty_flag)
1683                 return 0;
1684         if (s->ttyfd != -1)
1685                 return 0;
1686         s->term = packet_get_string(&len);
1687         s->col = packet_get_int();
1688         s->row = packet_get_int();
1689         s->xpixel = packet_get_int();
1690         s->ypixel = packet_get_int();
1691
1692         if (strcmp(s->term, "") == 0) {
1693                 xfree(s->term);
1694                 s->term = NULL;
1695         }
1696         /* Allocate a pty and open it. */
1697         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1698                 xfree(s->term);
1699                 s->term = NULL;
1700                 s->ptyfd = -1;
1701                 s->ttyfd = -1;
1702                 error("session_pty_req: session %d alloc failed", s->self);
1703                 return 0;
1704         }
1705         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1706         /*
1707          * Add a cleanup function to clear the utmp entry and record logout
1708          * time in case we call fatal() (e.g., the connection gets closed).
1709          */
1710         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1711         pty_setowner(s->pw, s->tty);
1712         /* Get window size from the packet. */
1713         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1714
1715         /* Get tty modes from the packet. */
1716         tty_parse_modes(s->ttyfd, &n_bytes);
1717         packet_done();
1718
1719         session_proctitle(s);
1720
1721         return 1;
1722 }
1723
1724 int
1725 session_subsystem_req(Session *s)
1726 {
1727         u_int len;
1728         int success = 0;
1729         char *subsys = packet_get_string(&len);
1730         int i;
1731
1732         packet_done();
1733         log("subsystem request for %s", subsys);
1734
1735         for (i = 0; i < options.num_subsystems; i++) {
1736                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1737                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1738                         s->is_subsystem = 1;
1739                         do_exec_no_pty(s, options.subsystem_command[i]);
1740                         success = 1;
1741                 }
1742         }
1743
1744         if (!success)
1745                 log("subsystem request for %s failed, subsystem not found", subsys);
1746
1747         xfree(subsys);
1748         return success;
1749 }
1750
1751 int
1752 session_x11_req(Session *s)
1753 {
1754         int fd;
1755         if (no_x11_forwarding_flag) {
1756                 debug("X11 forwarding disabled in user configuration file.");
1757                 return 0;
1758         }
1759         if (!options.x11_forwarding) {
1760                 debug("X11 forwarding disabled in server configuration file.");
1761                 return 0;
1762         }
1763         if (xauthfile != NULL) {
1764                 debug("X11 fwd already started.");
1765                 return 0;
1766         }
1767
1768         debug("Received request for X11 forwarding with auth spoofing.");
1769         if (s->display != NULL)
1770                 packet_disconnect("Protocol error: X11 display already set.");
1771
1772         s->single_connection = packet_get_char();
1773         s->auth_proto = packet_get_string(NULL);
1774         s->auth_data = packet_get_string(NULL);
1775         s->screen = packet_get_int();
1776         packet_done();
1777
1778         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1779         if (s->display == NULL) {
1780                 xfree(s->auth_proto);
1781                 xfree(s->auth_data);
1782                 return 0;
1783         }
1784         xauthfile = xmalloc(MAXPATHLEN);
1785         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1786         temporarily_use_uid(s->pw);
1787         if (mkdtemp(xauthfile) == NULL) {
1788                 restore_uid();
1789                 error("private X11 dir: mkdtemp %s failed: %s",
1790                     xauthfile, strerror(errno));
1791                 xfree(xauthfile);
1792                 xauthfile = NULL;
1793                 xfree(s->auth_proto);
1794                 xfree(s->auth_data);
1795                 /* XXXX remove listening channels */
1796                 return 0;
1797         }
1798         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1799         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1800         if (fd >= 0)
1801                 close(fd);
1802         restore_uid();
1803         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1804         return 1;
1805 }
1806
1807 int
1808 session_shell_req(Session *s)
1809 {
1810         /* if forced_command == NULL, the shell is execed */
1811         char *shell = forced_command;
1812         packet_done();
1813         if (s->ttyfd == -1)
1814                 do_exec_no_pty(s, shell);
1815         else
1816                 do_exec_pty(s, shell);
1817         return 1;
1818 }
1819
1820 int
1821 session_exec_req(Session *s)
1822 {
1823         u_int len;
1824         char *command = packet_get_string(&len);
1825         packet_done();
1826         if (forced_command) {
1827                 original_command = command;
1828                 command = forced_command;
1829                 debug("Forced command '%.500s'", forced_command);
1830         }
1831         if (s->ttyfd == -1)
1832                 do_exec_no_pty(s, command);
1833         else
1834                 do_exec_pty(s, command);
1835         if (forced_command == NULL)
1836                 xfree(command);
1837         return 1;
1838 }
1839
1840 int
1841 session_auth_agent_req(Session *s)
1842 {
1843         static int called = 0;
1844         packet_done();
1845         if (no_agent_forwarding_flag) {
1846                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1847                 return 0;
1848         }
1849         if (called) {
1850                 return 0;
1851         } else {
1852                 called = 1;
1853                 return auth_input_request_forwarding(s->pw);
1854         }
1855 }
1856
1857 void
1858 session_input_channel_req(int id, void *arg)
1859 {
1860         u_int len;
1861         int reply;
1862         int success = 0;
1863         char *rtype;
1864         Session *s;
1865         Channel *c;
1866
1867         rtype = packet_get_string(&len);
1868         reply = packet_get_char();
1869
1870         s = session_by_channel(id);
1871         if (s == NULL)
1872                 fatal("session_input_channel_req: channel %d: no session", id);
1873         c = channel_lookup(id);
1874         if (c == NULL)
1875                 fatal("session_input_channel_req: channel %d: bad channel", id);
1876
1877         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1878             s->self, id, rtype, reply);
1879
1880         /*
1881          * a session is in LARVAL state until a shell, a command
1882          * or a subsystem is executed
1883          */
1884         if (c->type == SSH_CHANNEL_LARVAL) {
1885                 if (strcmp(rtype, "shell") == 0) {
1886                         success = session_shell_req(s);
1887                 } else if (strcmp(rtype, "exec") == 0) {
1888                         success = session_exec_req(s);
1889                 } else if (strcmp(rtype, "pty-req") == 0) {
1890                         success =  session_pty_req(s);
1891                 } else if (strcmp(rtype, "x11-req") == 0) {
1892                         success = session_x11_req(s);
1893                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1894                         success = session_auth_agent_req(s);
1895                 } else if (strcmp(rtype, "subsystem") == 0) {
1896                         success = session_subsystem_req(s);
1897                 }
1898         }
1899         if (strcmp(rtype, "window-change") == 0) {
1900                 success = session_window_change_req(s);
1901         }
1902
1903         if (reply) {
1904                 packet_start(success ?
1905                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1906                 packet_put_int(c->remote_id);
1907                 packet_send();
1908         }
1909         xfree(rtype);
1910 }
1911
1912 void
1913 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1914 {
1915         if (!compat20)
1916                 fatal("session_set_fds: called for proto != 2.0");
1917         /*
1918          * now that have a child and a pipe to the child,
1919          * we can activate our channel and register the fd's
1920          */
1921         if (s->chanid == -1)
1922                 fatal("no channel for session %d", s->self);
1923         channel_set_fds(s->chanid,
1924             fdout, fdin, fderr,
1925             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1926             1);
1927 }
1928
1929 void
1930 session_pty_cleanup(Session *s)
1931 {
1932         if (s == NULL || s->ttyfd == -1)
1933                 return;
1934
1935         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1936
1937         /* Cancel the cleanup function. */
1938         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1939
1940         /* Record that the user has logged out. */
1941         record_logout(s->pid, s->tty);
1942
1943         /* Release the pseudo-tty. */
1944         pty_release(s->tty);
1945
1946         /*
1947          * Close the server side of the socket pairs.  We must do this after
1948          * the pty cleanup, so that another process doesn't get this pty
1949          * while we're still cleaning up.
1950          */
1951         if (close(s->ptymaster) < 0)
1952                 error("close(s->ptymaster): %s", strerror(errno));
1953 }
1954
1955 void
1956 session_exit_message(Session *s, int status)
1957 {
1958         Channel *c;
1959         if (s == NULL)
1960                 fatal("session_close: no session");
1961         c = channel_lookup(s->chanid);
1962         if (c == NULL)
1963                 fatal("session_close: session %d: no channel %d",
1964                     s->self, s->chanid);
1965         debug("session_exit_message: session %d channel %d pid %d",
1966             s->self, s->chanid, s->pid);
1967
1968         if (WIFEXITED(status)) {
1969                 channel_request_start(s->chanid,
1970                     "exit-status", 0);
1971                 packet_put_int(WEXITSTATUS(status));
1972                 packet_send();
1973         } else if (WIFSIGNALED(status)) {
1974                 channel_request_start(s->chanid,
1975                     "exit-signal", 0);
1976                 packet_put_int(WTERMSIG(status));
1977 #ifdef WCOREDUMP
1978                 packet_put_char(WCOREDUMP(status));
1979 #else /* WCOREDUMP */
1980                 packet_put_char(0);
1981 #endif /* WCOREDUMP */
1982                 packet_put_cstring("");
1983                 packet_put_cstring("");
1984                 packet_send();
1985         } else {
1986                 /* Some weird exit cause.  Just exit. */
1987                 packet_disconnect("wait returned status %04x.", status);
1988         }
1989
1990         /* disconnect channel */
1991         debug("session_exit_message: release channel %d", s->chanid);
1992         channel_cancel_cleanup(s->chanid);
1993         /*
1994          * emulate a write failure with 'chan_write_failed', nobody will be
1995          * interested in data we write.
1996          * Note that we must not call 'chan_read_failed', since there could
1997          * be some more data waiting in the pipe.
1998          */
1999         if (c->ostate != CHAN_OUTPUT_CLOSED)
2000                 chan_write_failed(c);
2001         s->chanid = -1;
2002 }
2003
2004 void
2005 session_free(Session *s)
2006 {
2007         debug("session_free: session %d pid %d", s->self, s->pid);
2008         if (s->term)
2009                 xfree(s->term);
2010         if (s->display)
2011                 xfree(s->display);
2012         if (s->auth_data)
2013                 xfree(s->auth_data);
2014         if (s->auth_proto)
2015                 xfree(s->auth_proto);
2016         s->used = 0;
2017 }
2018
2019 void
2020 session_close(Session *s)
2021 {
2022         session_pty_cleanup(s);
2023         session_free(s);
2024         session_proctitle(s);
2025 }
2026
2027 void
2028 session_close_by_pid(pid_t pid, int status)
2029 {
2030         Session *s = session_by_pid(pid);
2031         if (s == NULL) {
2032                 debug("session_close_by_pid: no session for pid %d", s->pid);
2033                 return;
2034         }
2035         if (s->chanid != -1)
2036                 session_exit_message(s, status);
2037         session_close(s);
2038 }
2039
2040 /*
2041  * this is called when a channel dies before
2042  * the session 'child' itself dies
2043  */
2044 void
2045 session_close_by_channel(int id, void *arg)
2046 {
2047         Session *s = session_by_channel(id);
2048         if (s == NULL) {
2049                 debug("session_close_by_channel: no session for channel %d", id);
2050                 return;
2051         }
2052         /* disconnect channel */
2053         channel_cancel_cleanup(s->chanid);
2054         s->chanid = -1;
2055
2056         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
2057         if (s->pid == 0) {
2058                 /* close session immediately */
2059                 session_close(s);
2060         } else {
2061                 /* notify child, delay session cleanup */
2062                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
2063                         error("session_close_by_channel: kill %d: %s",
2064                             s->pid, strerror(errno));
2065         }
2066 }
2067
2068 char *
2069 session_tty_list(void)
2070 {
2071         static char buf[1024];
2072         int i;
2073         buf[0] = '\0';
2074         for(i = 0; i < MAX_SESSIONS; i++) {
2075                 Session *s = &sessions[i];
2076                 if (s->used && s->ttyfd != -1) {
2077                         if (buf[0] != '\0')
2078                                 strlcat(buf, ",", sizeof buf);
2079                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2080                 }
2081         }
2082         if (buf[0] == '\0')
2083                 strlcpy(buf, "notty", sizeof buf);
2084         return buf;
2085 }
2086
2087 void
2088 session_proctitle(Session *s)
2089 {
2090         if (s->pw == NULL)
2091                 error("no user for session %d", s->self);
2092         else
2093                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2094 }
2095
2096 void
2097 do_authenticated2(Authctxt *authctxt)
2098 {
2099
2100         server_loop2();
2101         if (xauthfile)
2102                 xauthfile_cleanup_proc(NULL);
2103 }