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 1.57 2001/02/23 15:37:45 markus Exp $");
  37
  38 #include "ssh.h"
  39 #include "ssh1.h"
  40 #include "ssh2.h"
  41 #include "xmalloc.h"
  42 #include "sshpty.h"
  43 #include "packet.h"
  44 #include "buffer.h"
  45 #include "mpaux.h"
  46 #include "uidswap.h"
  47 #include "compat.h"
  48 #include "channels.h"
  49 #include "nchan.h"
  50 #include "bufaux.h"
  51 #include "auth.h"
  52 #include "auth-options.h"
  53 #include "pathnames.h"
  54 #include "log.h"
  55 #include "servconf.h"
  56 #include "sshlogin.h"
  57 #include "serverloop.h"
  58 #include "canohost.h"
  59 #include "session.h"
  60
  61 #ifdef WITH_IRIX_PROJECT
  62 #include <proj.h>
  63 #endif /* WITH_IRIX_PROJECT */
  64 #ifdef WITH_IRIX_JOBS
  65 #include <sys/resource.h>
  66 #endif
  67 #ifdef WITH_IRIX_AUDIT
  68 #include <sat.h>
  69 #endif /* WITH_IRIX_AUDIT */
  70
  71 #if defined(HAVE_USERSEC_H)
  72 #include <usersec.h>
  73 #endif
  74
  75 #ifdef HAVE_CYGWIN
  76 #include <windows.h>
  77 #include <sys/cygwin.h>
  78 #define is_winnt       (GetVersion() < 0x80000000)
  79 #endif
  80
  81 /* AIX limits */
  82 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  83 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  84 # define S_UCPU_HARD  S_UCPU "_hard"
  85 # define S_UDATA_HARD  S_UDATA "_hard"
  86 # define S_USTACK_HARD  S_USTACK "_hard"
  87 # define S_URSS_HARD  S_URSS "_hard"
  88 # define S_UCORE_HARD  S_UCORE "_hard"
  89 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  90 #endif
  91
  92 /* types */
  93
  94 #define TTYSZ 64
  95 typedef struct Session Session;
  96 struct Session {
  97         int     used;
  98         int     self;
  99         int     extended;
 100         struct  passwd *pw;
 101         pid_t   pid;
 102         /* tty */
 103         char    *term;
 104         int     ptyfd, ttyfd, ptymaster;
 105         int     row, col, xpixel, ypixel;
 106         char    tty[TTYSZ];
 107         /* X11 */
 108         char    *display;
 109         int     screen;
 110         char    *auth_proto;
 111         char    *auth_data;
 112         int     single_connection;
 113         /* proto 2 */
 114         int     chanid;
 115 };
 116
 117 /* func */
 118
 119 Session *session_new(void);
 120 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 121 void    session_pty_cleanup(Session *s);
 122 void    session_proctitle(Session *s);
 123 void    do_exec_pty(Session *s, const char *command, struct passwd * pw);
 124 void    do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
 125 void    do_login(Session *s, const char *command);
 126
 127 void
 128 do_child(const char *command, struct passwd * pw, const char *term,
 129     const char *display, const char *auth_proto,
 130     const char *auth_data, const char *ttyname);
 131
 132 /* import */
 133 extern ServerOptions options;
 134 extern char *__progname;
 135 extern int log_stderr;
 136 extern int debug_flag;
 137 extern u_int utmp_len;
 138
 139 extern int startup_pipe;
 140
 141 /* Local Xauthority file. */
 142 static char *xauthfile;
 143
 144 /* original command from peer. */
 145 char *original_command = NULL;
 146
 147 /* data */
 148 #define MAX_SESSIONS 10
 149 Session sessions[MAX_SESSIONS];
 150
 151 #ifdef WITH_AIXAUTHENTICATE
 152 /* AIX's lastlogin message, set in auth1.c */
 153 char *aixloginmsg;
 154 #endif /* WITH_AIXAUTHENTICATE */
 155
 156 #ifdef HAVE_LOGIN_CAP
 157 static login_cap_t *lc;
 158 #endif
 159
 160 /*
 161  * Remove local Xauthority file.
 162  */
 163 void
 164 xauthfile_cleanup_proc(void *ignore)
 165 {
 166         debug("xauthfile_cleanup_proc called");
 167
 168         if (xauthfile != NULL) {
 169                 char *p;
 170                 unlink(xauthfile);
 171                 p = strrchr(xauthfile, '/');
 172                 if (p != NULL) {
 173                         *p = '\0';
 174                         rmdir(xauthfile);
 175                 }
 176                 xfree(xauthfile);
 177                 xauthfile = NULL;
 178         }
 179 }
 180
 181 /*
 182  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 183  * dropped connection).
 184  */
 185 void
 186 pty_cleanup_proc(void *session)
 187 {
 188         Session *s=session;
 189         if (s == NULL)
 190                 fatal("pty_cleanup_proc: no session");
 191         debug("pty_cleanup_proc: %s", s->tty);
 192
 193         if (s->pid != 0) {
 194                 /* Record that the user has logged out. */
 195                 record_logout(s->pid, s->tty);
 196         }
 197
 198         /* Release the pseudo-tty. */
 199         pty_release(s->tty);
 200 }
 201
 202 /*
 203  * Prepares for an interactive session.  This is called after the user has
 204  * been successfully authenticated.  During this message exchange, pseudo
 205  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 206  * are requested, etc.
 207  */
 208 void
 209 do_authenticated(struct passwd * pw)
 210 {
 211         Session *s;
 212         int type, fd;
 213         int compression_level = 0, enable_compression_after_reply = 0;
 214         int have_pty = 0;
 215         char *command;
 216         int n_bytes;
 217         int plen;
 218         u_int proto_len, data_len, dlen;
 219         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         /*
 232          * Inform the channel mechanism that we are the server side and that
 233          * the client may request to connect to any port at all. (The user
 234          * could do it anyway, and we wouldn\'t know what is permitted except
 235          * by the client telling us, so we can equally well trust the client
 236          * not to request anything bogus.)
 237          */
 238         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 239                 channel_permit_all_opens();
 240
 241         s = session_new();
 242         s->pw = pw;
 243
 244 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 245         if ((lc = login_getclass(pw->pw_class)) == NULL) {
 246                 error("unable to get login class");
 247                 return;
 248         }
 249 #endif
 250
 251         /*
 252          * We stay in this loop until the client requests to execute a shell
 253          * or a command.
 254          */
 255         for (;;) {
 256                 int success = 0;
 257
 258                 /* Get a packet from the client. */
 259                 type = packet_read(&plen);
 260
 261                 /* Process the packet. */
 262                 switch (type) {
 263                 case SSH_CMSG_REQUEST_COMPRESSION:
 264                         packet_integrity_check(plen, 4, type);
 265                         compression_level = packet_get_int();
 266                         if (compression_level < 1 || compression_level > 9) {
 267                                 packet_send_debug("Received illegal compression level %d.",
 268                                      compression_level);
 269                                 break;
 270                         }
 271                         /* Enable compression after we have responded with SUCCESS. */
 272                         enable_compression_after_reply = 1;
 273                         success = 1;
 274                         break;
 275
 276                 case SSH_CMSG_REQUEST_PTY:
 277                         if (no_pty_flag) {
 278                                 debug("Allocating a pty not permitted for this authentication.");
 279                                 break;
 280                         }
 281                         if (have_pty)
 282                                 packet_disconnect("Protocol error: you already have a pty.");
 283
 284                         debug("Allocating pty.");
 285
 286                         /* Allocate a pty and open it. */
 287                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 288                             sizeof(s->tty))) {
 289                                 error("Failed to allocate pty.");
 290                                 break;
 291                         }
 292                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 293                         pty_setowner(pw, s->tty);
 294
 295                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 296                         s->term = packet_get_string(&dlen);
 297                         packet_integrity_check(dlen, strlen(s->term), type);
 298                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 299                         /* Remaining bytes */
 300                         n_bytes = plen - (4 + dlen + 4 * 4);
 301
 302                         if (strcmp(s->term, "") == 0) {
 303                                 xfree(s->term);
 304                                 s->term = NULL;
 305                         }
 306                         /* Get window size from the packet. */
 307                         s->row = packet_get_int();
 308                         s->col = packet_get_int();
 309                         s->xpixel = packet_get_int();
 310                         s->ypixel = packet_get_int();
 311                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 312
 313                         /* Get tty modes from the packet. */
 314                         tty_parse_modes(s->ttyfd, &n_bytes);
 315                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 316
 317                         session_proctitle(s);
 318
 319                         /* Indicate that we now have a pty. */
 320                         success = 1;
 321                         have_pty = 1;
 322                         break;
 323
 324                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 325                         if (!options.x11_forwarding) {
 326                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 327                                 break;
 328                         }
 329                         if (!options.xauth_location) {
 330                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 331                                 break;
 332                         }
 333                         if (no_x11_forwarding_flag) {
 334                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 335                                 break;
 336                         }
 337                         debug("Received request for X11 forwarding with auth spoofing.");
 338                         if (s->display != NULL)
 339                                 packet_disconnect("Protocol error: X11 display already set.");
 340
 341                         s->auth_proto = packet_get_string(&proto_len);
 342                         s->auth_data = packet_get_string(&data_len);
 343
 344                         screen_flag = packet_get_protocol_flags() &
 345                             SSH_PROTOFLAG_SCREEN_NUMBER;
 346                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 347
 348                         if (packet_remaining() == 4) {
 349                                 if (!screen_flag)
 350                                         debug2("Buggy client: "
 351                                             "X11 screen flag missing");
 352                                 packet_integrity_check(plen,
 353                                     4 + proto_len + 4 + data_len + 4, type);
 354                                 s->screen = packet_get_int();
 355                         } else {
 356                                 packet_integrity_check(plen,
 357                                     4 + proto_len + 4 + data_len, type);
 358                                 s->screen = 0;
 359                         }
 360                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 361
 362                         if (s->display == NULL)
 363                                 break;
 364
 365                         /* Setup to always have a local .Xauthority. */
 366                         xauthfile = xmalloc(MAXPATHLEN);
 367                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 368                         temporarily_use_uid(pw->pw_uid);
 369                         if (mkdtemp(xauthfile) == NULL) {
 370                                 restore_uid();
 371                                 error("private X11 dir: mkdtemp %s failed: %s",
 372                                     xauthfile, strerror(errno));
 373                                 xfree(xauthfile);
 374                                 xauthfile = NULL;
 375                                 /* XXXX remove listening channels */
 376                                 break;
 377                         }
 378                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 379                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 380                         if (fd >= 0)
 381                                 close(fd);
 382                         restore_uid();
 383                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 384                         success = 1;
 385                         break;
 386
 387                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 388                         if (no_agent_forwarding_flag || compat13) {
 389                                 debug("Authentication agent forwarding not permitted for this authentication.");
 390                                 break;
 391                         }
 392                         debug("Received authentication agent forwarding request.");
 393                         success = auth_input_request_forwarding(pw);
 394                         break;
 395
 396                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 397                         if (no_port_forwarding_flag) {
 398                                 debug("Port forwarding not permitted for this authentication.");
 399                                 break;
 400                         }
 401                         if (!options.allow_tcp_forwarding) {
 402                                 debug("Port forwarding not permitted.");
 403                                 break;
 404                         }
 405                         debug("Received TCP/IP port forwarding request.");
 406                         channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
 407                         success = 1;
 408                         break;
 409
 410                 case SSH_CMSG_MAX_PACKET_SIZE:
 411                         if (packet_set_maxsize(packet_get_int()) > 0)
 412                                 success = 1;
 413                         break;
 414
 415                 case SSH_CMSG_EXEC_SHELL:
 416                 case SSH_CMSG_EXEC_CMD:
 417                         if (type == SSH_CMSG_EXEC_CMD) {
 418                                 command = packet_get_string(&dlen);
 419                                 debug("Exec command '%.500s'", command);
 420                                 packet_integrity_check(plen, 4 + dlen, type);
 421                         } else {
 422                                 command = NULL;
 423                                 packet_integrity_check(plen, 0, type);
 424                         }
 425                         if (forced_command != NULL) {
 426                                 original_command = command;
 427                                 command = forced_command;
 428                                 debug("Forced command '%.500s'", forced_command);
 429                         }
 430                         if (have_pty)
 431                                 do_exec_pty(s, command, pw);
 432                         else
 433                                 do_exec_no_pty(s, command, pw);
 434
 435                         if (command != NULL)
 436                                 xfree(command);
 437                         /* Cleanup user's local Xauthority file. */
 438                         if (xauthfile)
 439                                 xauthfile_cleanup_proc(NULL);
 440                         return;
 441
 442                 default:
 443                         /*
 444                          * Any unknown messages in this phase are ignored,
 445                          * and a failure message is returned.
 446                          */
 447                         log("Unknown packet type received after authentication: %d", type);
 448                 }
 449                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 450                 packet_send();
 451                 packet_write_wait();
 452
 453                 /* Enable compression now that we have replied if appropriate. */
 454                 if (enable_compression_after_reply) {
 455                         enable_compression_after_reply = 0;
 456                         packet_start_compression(compression_level);
 457                 }
 458         }
 459 }
 460
 461 /*
 462  * This is called to fork and execute a command when we have no tty.  This
 463  * will call do_child from the child, and server_loop from the parent after
 464  * setting up file descriptors and such.
 465  */
 466 void
 467 do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
 468 {
 469         int pid;
 470
 471 #ifdef USE_PIPES
 472         int pin[2], pout[2], perr[2];
 473         /* Allocate pipes for communicating with the program. */
 474         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 475                 packet_disconnect("Could not create pipes: %.100s",
 476                                   strerror(errno));
 477 #else /* USE_PIPES */
 478         int inout[2], err[2];
 479         /* Uses socket pairs to communicate with the program. */
 480         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 481             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 482                 packet_disconnect("Could not create socket pairs: %.100s",
 483                                   strerror(errno));
 484 #endif /* USE_PIPES */
 485         if (s == NULL)
 486                 fatal("do_exec_no_pty: no session");
 487
 488         session_proctitle(s);
 489
 490 #ifdef USE_PAM
 491         do_pam_setcred();
 492 #endif /* USE_PAM */
 493
 494         /* Fork the child. */
 495         if ((pid = fork()) == 0) {
 496                 /* Child.  Reinitialize the log since the pid has changed. */
 497                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 498
 499                 signal(SIGPIPE, SIG_DFL);
 500
 501                 /*
 502                  * Create a new session and process group since the 4.4BSD
 503                  * setlogin() affects the entire process group.
 504                  */
 505                 if (setsid() < 0)
 506                         error("setsid failed: %.100s", strerror(errno));
 507
 508 #ifdef USE_PIPES
 509                 /*
 510                  * Redirect stdin.  We close the parent side of the socket
 511                  * pair, and make the child side the standard input.
 512                  */
 513                 close(pin[1]);
 514                 if (dup2(pin[0], 0) < 0)
 515                         perror("dup2 stdin");
 516                 close(pin[0]);
 517
 518                 /* Redirect stdout. */
 519                 close(pout[0]);
 520                 if (dup2(pout[1], 1) < 0)
 521                         perror("dup2 stdout");
 522                 close(pout[1]);
 523
 524                 /* Redirect stderr. */
 525                 close(perr[0]);
 526                 if (dup2(perr[1], 2) < 0)
 527                         perror("dup2 stderr");
 528                 close(perr[1]);
 529 #else /* USE_PIPES */
 530                 /*
 531                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 532                  * use the same socket, as some programs (particularly rdist)
 533                  * seem to depend on it.
 534                  */
 535                 close(inout[1]);
 536                 close(err[1]);
 537                 if (dup2(inout[0], 0) < 0)      /* stdin */
 538                         perror("dup2 stdin");
 539                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 540                         perror("dup2 stdout");
 541                 if (dup2(err[0], 2) < 0)        /* stderr */
 542                         perror("dup2 stderr");
 543 #endif /* USE_PIPES */
 544
 545                 /* Do processing for the child (exec command etc). */
 546                 do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
 547                 /* NOTREACHED */
 548         }
 549 #ifdef HAVE_CYGWIN
 550         if (is_winnt)
 551                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 552 #endif
 553         if (pid < 0)
 554                 packet_disconnect("fork failed: %.100s", strerror(errno));
 555         s->pid = pid;
 556         /* Set interactive/non-interactive mode. */
 557         packet_set_interactive(s->display != NULL);
 558 #ifdef USE_PIPES
 559         /* We are the parent.  Close the child sides of the pipes. */
 560         close(pin[0]);
 561         close(pout[1]);
 562         close(perr[1]);
 563
 564         if (compat20) {
 565                 session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
 566         } else {
 567                 /* Enter the interactive session. */
 568                 server_loop(pid, pin[1], pout[0], perr[0]);
 569                 /* server_loop has closed pin[1], pout[1], and perr[1]. */
 570         }
 571 #else /* USE_PIPES */
 572         /* We are the parent.  Close the child sides of the socket pairs. */
 573         close(inout[0]);
 574         close(err[0]);
 575
 576         /*
 577          * Enter the interactive session.  Note: server_loop must be able to
 578          * handle the case that fdin and fdout are the same.
 579          */
 580         if (compat20) {
 581                 session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
 582         } else {
 583                 server_loop(pid, inout[1], inout[1], err[1]);
 584                 /* server_loop has closed inout[1] and err[1]. */
 585         }
 586 #endif /* USE_PIPES */
 587 }
 588
 589 /*
 590  * This is called to fork and execute a command when we have a tty.  This
 591  * will call do_child from the child, and server_loop from the parent after
 592  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 593  * lastlog, and other such operations.
 594  */
 595 void
 596 do_exec_pty(Session *s, const char *command, struct passwd * pw)
 597 {
 598         int fdout, ptyfd, ttyfd, ptymaster;
 599         pid_t pid;
 600
 601         if (s == NULL)
 602                 fatal("do_exec_pty: no session");
 603         ptyfd = s->ptyfd;
 604         ttyfd = s->ttyfd;
 605
 606 #ifdef USE_PAM
 607         do_pam_session(pw->pw_name, s->tty);
 608         do_pam_setcred();
 609 #endif /* USE_PAM */
 610
 611         /* Fork the child. */
 612         if ((pid = fork()) == 0) {
 613                 /* Child.  Reinitialize the log because the pid has changed. */
 614                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 615
 616                 signal(SIGPIPE, SIG_DFL);
 617
 618                 /* Close the master side of the pseudo tty. */
 619                 close(ptyfd);
 620
 621                 /* Make the pseudo tty our controlling tty. */
 622                 pty_make_controlling_tty(&ttyfd, s->tty);
 623
 624                 /* Redirect stdin from the pseudo tty. */
 625                 if (dup2(ttyfd, fileno(stdin)) < 0)
 626                         error("dup2 stdin failed: %.100s", strerror(errno));
 627
 628                 /* Redirect stdout to the pseudo tty. */
 629                 if (dup2(ttyfd, fileno(stdout)) < 0)
 630                         error("dup2 stdin failed: %.100s", strerror(errno));
 631
 632                 /* Redirect stderr to the pseudo tty. */
 633                 if (dup2(ttyfd, fileno(stderr)) < 0)
 634                         error("dup2 stdin failed: %.100s", strerror(errno));
 635
 636                 /* Close the extra descriptor for the pseudo tty. */
 637                 close(ttyfd);
 638
 639                 /* record login, etc. similar to login(1) */
 640                 if (!(options.use_login && command == NULL))
 641                         do_login(s, command);
 642
 643                 /* Do common processing for the child, such as execing the command. */
 644                 do_child(command, pw, s->term, s->display, s->auth_proto,
 645                     s->auth_data, s->tty);
 646                 /* NOTREACHED */
 647         }
 648 #ifdef HAVE_CYGWIN
 649         if (is_winnt)
 650                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 651 #endif
 652         if (pid < 0)
 653                 packet_disconnect("fork failed: %.100s", strerror(errno));
 654         s->pid = pid;
 655
 656         /* Parent.  Close the slave side of the pseudo tty. */
 657         close(ttyfd);
 658
 659         /*
 660          * Create another descriptor of the pty master side for use as the
 661          * standard input.  We could use the original descriptor, but this
 662          * simplifies code in server_loop.  The descriptor is bidirectional.
 663          */
 664         fdout = dup(ptyfd);
 665         if (fdout < 0)
 666                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 667
 668         /* we keep a reference to the pty master */
 669         ptymaster = dup(ptyfd);
 670         if (ptymaster < 0)
 671                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 672         s->ptymaster = ptymaster;
 673
 674         /* Enter interactive session. */
 675         packet_set_interactive(1);
 676         if (compat20) {
 677                 session_set_fds(s, ptyfd, fdout, -1);
 678         } else {
 679                 server_loop(pid, ptyfd, fdout, -1);
 680                 /* server_loop _has_ closed ptyfd and fdout. */
 681                 session_pty_cleanup(s);
 682         }
 683 }
 684
 685 const char *
 686 get_remote_name_or_ip(void)
 687 {
 688         static const char *remote = "";
 689         if (utmp_len > 0)
 690                 remote = get_canonical_hostname(options.reverse_mapping_check);
 691         if (utmp_len == 0 || strlen(remote) > utmp_len)
 692                 remote = get_remote_ipaddr();
 693         return remote;
 694 }
 695
 696 /* administrative, login(1)-like work */
 697 void
 698 do_login(Session *s, const char *command)
 699 {
 700         FILE *f;
 701         char *time_string;
 702         char buf[256];
 703         char hostname[MAXHOSTNAMELEN];
 704         socklen_t fromlen;
 705         struct sockaddr_storage from;
 706         struct stat st;
 707         time_t last_login_time;
 708         struct passwd * pw = s->pw;
 709         pid_t pid = getpid();
 710
 711         /*
 712          * Get IP address of client. If the connection is not a socket, let
 713          * the address be 0.0.0.0.
 714          */
 715         memset(&from, 0, sizeof(from));
 716         if (packet_connection_is_on_socket()) {
 717                 fromlen = sizeof(from);
 718                 if (getpeername(packet_get_connection_in(),
 719                      (struct sockaddr *) & from, &fromlen) < 0) {
 720                         debug("getpeername: %.100s", strerror(errno));
 721                         fatal_cleanup();
 722                 }
 723         }
 724
 725         /* Get the time and hostname when the user last logged in. */
 726         hostname[0] = '\0';
 727         last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 728             hostname, sizeof(hostname));
 729
 730         /* Record that there was a login on that tty from the remote host. */
 731         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 732             get_remote_name_or_ip(), (struct sockaddr *)&from);
 733
 734 #ifdef USE_PAM
 735         /*
 736          * If password change is needed, do it now.
 737          * This needs to occur before the ~/.hushlogin check.
 738          */
 739         if (is_pam_password_change_required()) {
 740                 print_pam_messages();
 741                 do_pam_chauthtok();
 742         }
 743 #endif
 744
 745         /* Done if .hushlogin exists or a command given. */
 746         if (command != NULL)
 747                 return;
 748         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 749 #ifdef HAVE_LOGIN_CAP
 750         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 751 #else
 752         if (stat(buf, &st) >= 0)
 753 #endif
 754                 return;
 755
 756 #ifdef USE_PAM
 757         if (!is_pam_password_change_required())
 758                 print_pam_messages();
 759 #endif /* USE_PAM */
 760 #ifdef WITH_AIXAUTHENTICATE
 761         if (aixloginmsg && *aixloginmsg)
 762                 printf("%s\n", aixloginmsg);
 763 #endif /* WITH_AIXAUTHENTICATE */
 764
 765         if (last_login_time != 0) {
 766                 time_string = ctime(&last_login_time);
 767                 if (strchr(time_string, '\n'))
 768                         *strchr(time_string, '\n') = 0;
 769                 if (strcmp(hostname, "") == 0)
 770                         printf("Last login: %s\r\n", time_string);
 771                 else
 772                         printf("Last login: %s from %s\r\n", time_string, hostname);
 773         }
 774         if (options.print_motd) {
 775 #ifdef HAVE_LOGIN_CAP
 776                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 777                     "/etc/motd"), "r");
 778 #else
 779                 f = fopen("/etc/motd", "r");
 780 #endif
 781                 if (f) {
 782                         while (fgets(buf, sizeof(buf), f))
 783                                 fputs(buf, stdout);
 784                         fclose(f);
 785                 }
 786         }
 787 }
 788
 789 /*
 790  * Sets the value of the given variable in the environment.  If the variable
 791  * already exists, its value is overriden.
 792  */
 793 void
 794 child_set_env(char ***envp, u_int *envsizep, const char *name,
 795               const char *value)
 796 {
 797         u_int i, namelen;
 798         char **env;
 799
 800         /*
 801          * Find the slot where the value should be stored.  If the variable
 802          * already exists, we reuse the slot; otherwise we append a new slot
 803          * at the end of the array, expanding if necessary.
 804          */
 805         env = *envp;
 806         namelen = strlen(name);
 807         for (i = 0; env[i]; i++)
 808                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 809                         break;
 810         if (env[i]) {
 811                 /* Reuse the slot. */
 812                 xfree(env[i]);
 813         } else {
 814                 /* New variable.  Expand if necessary. */
 815                 if (i >= (*envsizep) - 1) {
 816                         (*envsizep) += 50;
 817                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 818                 }
 819                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 820                 env[i + 1] = NULL;
 821         }
 822
 823         /* Allocate space and format the variable in the appropriate slot. */
 824         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 825         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 826 }
 827
 828 /*
 829  * Reads environment variables from the given file and adds/overrides them
 830  * into the environment.  If the file does not exist, this does nothing.
 831  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 832  * and assignments of the form name=value.  No other forms are allowed.
 833  */
 834 void
 835 read_environment_file(char ***env, u_int *envsize,
 836                       const char *filename)
 837 {
 838         FILE *f;
 839         char buf[4096];
 840         char *cp, *value;
 841
 842         f = fopen(filename, "r");
 843         if (!f)
 844                 return;
 845
 846         while (fgets(buf, sizeof(buf), f)) {
 847                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 848                         ;
 849                 if (!*cp || *cp == '#' || *cp == '\n')
 850                         continue;
 851                 if (strchr(cp, '\n'))
 852                         *strchr(cp, '\n') = '\0';
 853                 value = strchr(cp, '=');
 854                 if (value == NULL) {
 855                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 856                         continue;
 857                 }
 858                 /*
 859                  * Replace the equals sign by nul, and advance value to
 860                  * the value string.
 861                  */
 862                 *value = '\0';
 863                 value++;
 864                 child_set_env(env, envsize, cp, value);
 865         }
 866         fclose(f);
 867 }
 868
 869 #ifdef USE_PAM
 870 /*
 871  * Sets any environment variables which have been specified by PAM
 872  */
 873 void do_pam_environment(char ***env, int *envsize)
 874 {
 875         char *equals, var_name[512], var_val[512];
 876         char **pam_env;
 877         int i;
 878
 879         if ((pam_env = fetch_pam_environment()) == NULL)
 880                 return;
 881
 882         for(i = 0; pam_env[i] != NULL; i++) {
 883                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 884                         continue;
 885
 886                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 887                         memset(var_name, '\0', sizeof(var_name));
 888                         memset(var_val, '\0', sizeof(var_val));
 889
 890                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 891                         strcpy(var_val, equals + 1);
 892
 893                         debug3("PAM environment: %s=%s", var_name, var_val);
 894
 895                         child_set_env(env, envsize, var_name, var_val);
 896                 }
 897         }
 898 }
 899 #endif /* USE_PAM */
 900
 901 #ifdef HAVE_CYGWIN
 902 void copy_environment(char ***env, int *envsize)
 903 {
 904         char *equals, var_name[512], var_val[512];
 905         int i;
 906
 907         for(i = 0; environ[i] != NULL; i++) {
 908                 if ((equals = strstr(environ[i], "=")) == NULL)
 909                         continue;
 910
 911                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 912                         memset(var_name, '\0', sizeof(var_name));
 913                         memset(var_val, '\0', sizeof(var_val));
 914
 915                         strncpy(var_name, environ[i], equals - environ[i]);
 916                         strcpy(var_val, equals + 1);
 917
 918                         debug3("Copy environment: %s=%s", var_name, var_val);
 919
 920                         child_set_env(env, envsize, var_name, var_val);
 921                 }
 922         }
 923 }
 924 #endif
 925
 926 #if defined(HAVE_GETUSERATTR)
 927 /*
 928  * AIX-specific login initialisation
 929  */
 930 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 931 {
 932         struct rlimit rlim;
 933         int slim, hlim;
 934
 935         getrlimit(resource, &rlim);
 936
 937         slim = 0;
 938         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 939                 if (slim < 0) {
 940                         rlim.rlim_cur = RLIM_INFINITY;
 941                 } else if (slim != 0) {
 942                         /* See the wackiness below */
 943                         if (rlim.rlim_cur == slim * mult)
 944                                 slim = 0;
 945                         else
 946                                 rlim.rlim_cur = slim * mult;
 947                 }
 948         }
 949
 950         hlim = 0;
 951         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 952                 if (hlim < 0) {
 953                         rlim.rlim_max = RLIM_INFINITY;
 954                 } else if (hlim != 0) {
 955                         rlim.rlim_max = hlim * mult;
 956                 }
 957         }
 958
 959         /*
 960          * XXX For cpu and fsize the soft limit is set to the hard limit
 961          * if the hard limit is left at its default value and the soft limit
 962          * is changed from its default value, either by requesting it
 963          * (slim == 0) or by setting it to the current default.  At least
 964          * that's how rlogind does it.  If you're confused you're not alone.
 965          * Bug or feature? AIX 4.3.1.2
 966          */
 967         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 968             && hlim == 0 && slim != 0)
 969                 rlim.rlim_max = rlim.rlim_cur;
 970         /* A specified hard limit limits the soft limit */
 971         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 972                 rlim.rlim_cur = rlim.rlim_max;
 973         /* A soft limit can increase a hard limit */
 974         else if (rlim.rlim_cur > rlim.rlim_max)
 975                 rlim.rlim_max = rlim.rlim_cur;
 976
 977         if (setrlimit(resource, &rlim) != 0)
 978                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 979 }
 980
 981 void set_limits_from_userattr(char *user)
 982 {
 983         int mask;
 984         char buf[16];
 985
 986         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 987         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 988         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 989         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 990         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 991         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 992 #if defined(S_UNOFILE)
 993         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
 994 #endif
 995
 996         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
 997                 /* Convert decimal to octal */
 998                 (void) snprintf(buf, sizeof(buf), "%d", mask);
 999                 if (sscanf(buf, "%o", &mask) == 1)
1000                         umask(mask);
1001         }
1002 }
1003 #endif /* defined(HAVE_GETUSERATTR) */
1004
1005 /*
1006  * Performs common processing for the child, such as setting up the
1007  * environment, closing extra file descriptors, setting the user and group
1008  * ids, and executing the command or shell.
1009  */
1010 void
1011 do_child(const char *command, struct passwd * pw, const char *term,
1012          const char *display, const char *auth_proto,
1013          const char *auth_data, const char *ttyname)
1014 {
1015         const char *shell, *hostname = NULL, *cp = NULL;
1016         char buf[256];
1017         char cmd[1024];
1018         FILE *f = NULL;
1019         u_int envsize, i;
1020         char **env;
1021         extern char **environ;
1022         struct stat st;
1023         char *argv[10];
1024 #ifdef WITH_IRIX_PROJECT
1025         prid_t projid;
1026 #endif /* WITH_IRIX_PROJECT */
1027 #ifdef WITH_IRIX_JOBS
1028         jid_t jid = 0;
1029 #else
1030 #ifdef WITH_IRIX_ARRAY
1031         int jid = 0;
1032 #endif /* WITH_IRIX_ARRAY */
1033 #endif /* WITH_IRIX_JOBS */
1034
1035
1036         /* login(1) is only called if we execute the login shell */
1037         if (options.use_login && command != NULL)
1038                 options.use_login = 0;
1039
1040 #ifndef USE_PAM /* pam_nologin handles this */
1041         if (!options.use_login) {
1042 # ifdef HAVE_LOGIN_CAP
1043                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1044                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1045                             _PATH_NOLOGIN), "r");
1046 # else /* HAVE_LOGIN_CAP */
1047                 if (pw->pw_uid)
1048                         f = fopen(_PATH_NOLOGIN, "r");
1049 # endif /* HAVE_LOGIN_CAP */
1050                 if (f) {
1051                         /* /etc/nologin exists.  Print its contents and exit. */
1052                         while (fgets(buf, sizeof(buf), f))
1053                                 fputs(buf, stderr);
1054                         fclose(f);
1055                         exit(254);
1056                 }
1057         }
1058 #endif /* USE_PAM */
1059
1060         /* Set login name, uid, gid, and groups. */
1061         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1062            switch, so we let login(1) to this for us. */
1063         if (!options.use_login) {
1064 #ifdef HAVE_OSF_SIA
1065                 session_setup_sia(pw->pw_name, ttyname);
1066 #else /* HAVE_OSF_SIA */
1067 #ifdef HAVE_CYGWIN
1068                 if (is_winnt) {
1069 #else
1070                 if (getuid() == 0 || geteuid() == 0) {
1071 #endif
1072 # ifdef HAVE_GETUSERATTR
1073                         set_limits_from_userattr(pw->pw_name);
1074 # endif /* HAVE_GETUSERATTR */
1075 # ifdef HAVE_LOGIN_CAP
1076                         if (setusercontext(lc, pw, pw->pw_uid,
1077                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1078                                 perror("unable to set user context");
1079                                 exit(1);
1080                         }
1081 #ifdef BSD_AUTH
1082                         if (auth_approval(NULL, lc, pw->pw_name, "ssh") <= 0) {
1083                                 error("approval failure for %s", pw->pw_name);
1084                                 fprintf(stderr, "Approval failure");
1085                                 exit(1);
1086                         }
1087 #endif
1088 # else /* HAVE_LOGIN_CAP */
1089 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1090                         /* Sets login uid for accounting */
1091                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1092                                 error("setluid: %s", strerror(errno));
1093 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1094
1095                         if (setlogin(pw->pw_name) < 0)
1096                                 error("setlogin failed: %s", strerror(errno));
1097                         if (setgid(pw->pw_gid) < 0) {
1098                                 perror("setgid");
1099                                 exit(1);
1100                         }
1101                         /* Initialize the group list. */
1102                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1103                                 perror("initgroups");
1104                                 exit(1);
1105                         }
1106                         endgrent();
1107 #  ifdef WITH_IRIX_JOBS
1108                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1109                         if (jid == -1) {
1110                                 fatal("Failed to create job container: %.100s",
1111                                       strerror(errno));
1112                         }
1113 #  endif /* WITH_IRIX_JOBS */
1114 #  ifdef WITH_IRIX_ARRAY
1115                         /* initialize array session */
1116                         if (jid == 0) {
1117                                 if (newarraysess() != 0)
1118                                         fatal("Failed to set up new array session: %.100s",
1119                                               strerror(errno));
1120                         }
1121 #  endif /* WITH_IRIX_ARRAY */
1122 #  ifdef WITH_IRIX_PROJECT
1123                         /* initialize irix project info */
1124                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1125                           debug("Failed to get project id, using projid 0");
1126                           projid = 0;
1127                         }
1128                         if (setprid(projid))
1129                           fatal("Failed to initialize project %d for %s: %.100s",
1130                                 (int)projid, pw->pw_name, strerror(errno));
1131 #  endif /* WITH_IRIX_PROJECT */
1132 #ifdef WITH_IRIX_AUDIT
1133                         if (sysconf(_SC_AUDIT)) {
1134                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1135                                 if (satsetid(pw->pw_uid))
1136                                         debug("error setting satid: %.100s", strerror(errno));
1137                         }
1138 #endif /* WITH_IRIX_AUDIT */
1139
1140                         /* Permanently switch to the desired uid. */
1141                         permanently_set_uid(pw->pw_uid);
1142 # endif /* HAVE_LOGIN_CAP */
1143                 }
1144 #endif /* HAVE_OSF_SIA */
1145
1146 #ifdef HAVE_CYGWIN
1147                 if (is_winnt)
1148 #endif
1149                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1150                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1151         }
1152         /*
1153          * Get the shell from the password data.  An empty shell field is
1154          * legal, and means /bin/sh.
1155          */
1156         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1157 #ifdef HAVE_LOGIN_CAP
1158         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1159 #endif
1160
1161 #ifdef AFS
1162         /* Try to get AFS tokens for the local cell. */
1163         if (k_hasafs()) {
1164                 char cell[64];
1165
1166                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1167                         krb_afslog(cell, 0);
1168
1169                 krb_afslog(0, 0);
1170         }
1171 #endif /* AFS */
1172
1173         /* Initialize the environment. */
1174         envsize = 100;
1175         env = xmalloc(envsize * sizeof(char *));
1176         env[0] = NULL;
1177
1178 #ifdef HAVE_CYGWIN
1179         /*
1180          * The Windows environment contains some setting which are
1181          * important for a running system. They must not be dropped.
1182          */
1183         copy_environment(&env, &envsize);
1184 #endif
1185
1186         if (!options.use_login) {
1187                 /* Set basic environment. */
1188                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1189                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1190                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1191 #ifdef HAVE_LOGIN_CAP
1192                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1193                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1194 #else /* HAVE_LOGIN_CAP */
1195 # ifndef HAVE_CYGWIN
1196                 /*
1197                  * There's no standard path on Windows. The path contains
1198                  * important components pointing to the system directories,
1199                  * needed for loading shared libraries. So the path better
1200                  * remains intact here.
1201                  */
1202                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1203 # endif /* HAVE_CYGWIN */
1204 #endif /* HAVE_LOGIN_CAP */
1205
1206                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1207                          _PATH_MAILDIR, pw->pw_name);
1208                 child_set_env(&env, &envsize, "MAIL", buf);
1209
1210                 /* Normal systems set SHELL by default. */
1211                 child_set_env(&env, &envsize, "SHELL", shell);
1212         }
1213         if (getenv("TZ"))
1214                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1215
1216         /* Set custom environment options from RSA authentication. */
1217         while (custom_environment) {
1218                 struct envstring *ce = custom_environment;
1219                 char *s = ce->s;
1220                 int i;
1221                 for (i = 0; s[i] != '=' && s[i]; i++);
1222                 if (s[i] == '=') {
1223                         s[i] = 0;
1224                         child_set_env(&env, &envsize, s, s + i + 1);
1225                 }
1226                 custom_environment = ce->next;
1227                 xfree(ce->s);
1228                 xfree(ce);
1229         }
1230
1231         snprintf(buf, sizeof buf, "%.50s %d %d",
1232                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1233         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1234
1235         if (ttyname)
1236                 child_set_env(&env, &envsize, "SSH_TTY", ttyname);
1237         if (term)
1238                 child_set_env(&env, &envsize, "TERM", term);
1239         if (display)
1240                 child_set_env(&env, &envsize, "DISPLAY", display);
1241         if (original_command)
1242                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1243                     original_command);
1244
1245 #ifdef _AIX
1246         if ((cp = getenv("AUTHSTATE")) != NULL)
1247                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1248         if ((cp = getenv("KRB5CCNAME")) != NULL)
1249                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1250         read_environment_file(&env, &envsize, "/etc/environment");
1251 #endif
1252
1253 #ifdef KRB4
1254         {
1255                 extern char *ticket;
1256
1257                 if (ticket)
1258                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1259         }
1260 #endif /* KRB4 */
1261
1262 #ifdef USE_PAM
1263         /* Pull in any environment variables that may have been set by PAM. */
1264         do_pam_environment(&env, &envsize);
1265 #endif /* USE_PAM */
1266
1267         if (xauthfile)
1268                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1269         if (auth_get_socket_name() != NULL)
1270                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1271                               auth_get_socket_name());
1272
1273         /* read $HOME/.ssh/environment. */
1274         if (!options.use_login) {
1275                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1276                     pw->pw_dir);
1277                 read_environment_file(&env, &envsize, buf);
1278         }
1279         if (debug_flag) {
1280                 /* dump the environment */
1281                 fprintf(stderr, "Environment:\n");
1282                 for (i = 0; env[i]; i++)
1283                         fprintf(stderr, "  %.200s\n", env[i]);
1284         }
1285         /* we have to stash the hostname before we close our socket. */
1286         if (options.use_login)
1287                 hostname = get_remote_name_or_ip();
1288         /*
1289          * Close the connection descriptors; note that this is the child, and
1290          * the server will still have the socket open, and it is important
1291          * that we do not shutdown it.  Note that the descriptors cannot be
1292          * closed before building the environment, as we call
1293          * get_remote_ipaddr there.
1294          */
1295         if (packet_get_connection_in() == packet_get_connection_out())
1296                 close(packet_get_connection_in());
1297         else {
1298                 close(packet_get_connection_in());
1299                 close(packet_get_connection_out());
1300         }
1301         /*
1302          * Close all descriptors related to channels.  They will still remain
1303          * open in the parent.
1304          */
1305         /* XXX better use close-on-exec? -markus */
1306         channel_close_all();
1307
1308         /*
1309          * Close any extra file descriptors.  Note that there may still be
1310          * descriptors left by system functions.  They will be closed later.
1311          */
1312         endpwent();
1313
1314         /*
1315          * Close any extra open file descriptors so that we don\'t have them
1316          * hanging around in clients.  Note that we want to do this after
1317          * initgroups, because at least on Solaris 2.3 it leaves file
1318          * descriptors open.
1319          */
1320         for (i = 3; i < 64; i++)
1321                 close(i);
1322
1323         /* Change current directory to the user\'s home directory. */
1324         if (chdir(pw->pw_dir) < 0) {
1325                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1326                         pw->pw_dir, strerror(errno));
1327 #ifdef HAVE_LOGIN_CAP
1328                 if (login_getcapbool(lc, "requirehome", 0))
1329                         exit(1);
1330 #endif
1331         }
1332
1333         /*
1334          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1335          * xauth are run in the proper environment.
1336          */
1337         environ = env;
1338
1339         /*
1340          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1341          * in this order).
1342          */
1343         if (!options.use_login) {
1344                 if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1345                         if (debug_flag)
1346                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_USER_RC);
1347
1348                         f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1349                         if (f) {
1350                                 if (auth_proto != NULL && auth_data != NULL)
1351                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1352                                 pclose(f);
1353                         } else
1354                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_USER_RC);
1355                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1356                         if (debug_flag)
1357                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_SYSTEM_RC);
1358
1359                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1360                         if (f) {
1361                                 if (auth_proto != NULL && auth_data != NULL)
1362                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1363                                 pclose(f);
1364                         } else
1365                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_SYSTEM_RC);
1366                 } else if (options.xauth_location != NULL) {
1367                         /* Add authority data to .Xauthority if appropriate. */
1368                         if (auth_proto != NULL && auth_data != NULL) {
1369                                 char *screen = strchr(display, ':');
1370                                 if (debug_flag) {
1371                                         fprintf(stderr,
1372                                             "Running %.100s add %.100s %.100s %.100s\n",
1373                                             options.xauth_location, display,
1374                                             auth_proto, auth_data);
1375 #ifndef NO_X11_UNIX_SOCKETS
1376                                         if (screen != NULL)
1377                                                 fprintf(stderr,
1378                                                     "Adding %.*s/unix%s %s %s\n",
1379                                                     (int)(screen-display), display,
1380                                                     screen, auth_proto, auth_data);
1381 #endif /* NO_X11_UNIX_SOCKETS */
1382                                 }
1383                                 snprintf(cmd, sizeof cmd, "%s -q -",
1384                                     options.xauth_location);
1385                                 f = popen(cmd, "w");
1386                                 if (f) {
1387                                         fprintf(f, "add %s %s %s\n", display,
1388                                             auth_proto, auth_data);
1389 #ifndef NO_X11_UNIX_SOCKETS
1390                                         if (screen != NULL)
1391                                                 fprintf(f, "add %.*s/unix%s %s %s\n",
1392                                                     (int)(screen-display), display,
1393                                                     screen, auth_proto, auth_data);
1394 #endif /* NO_X11_UNIX_SOCKETS */
1395                                         pclose(f);
1396                                 } else {
1397                                         fprintf(stderr, "Could not run %s\n",
1398                                             cmd);
1399                                 }
1400                         }
1401                 }
1402                 /* Get the last component of the shell name. */
1403                 cp = strrchr(shell, '/');
1404                 if (cp)
1405                         cp++;
1406                 else
1407                         cp = shell;
1408         }
1409         /*
1410          * If we have no command, execute the shell.  In this case, the shell
1411          * name to be passed in argv[0] is preceded by '-' to indicate that
1412          * this is a login shell.
1413          */
1414         if (!command) {
1415                 if (!options.use_login) {
1416                         char buf[256];
1417
1418                         /*
1419                          * Check for mail if we have a tty and it was enabled
1420                          * in server options.
1421                          */
1422                         if (ttyname && options.check_mail) {
1423                                 char *mailbox;
1424                                 struct stat mailstat;
1425                                 mailbox = getenv("MAIL");
1426                                 if (mailbox != NULL) {
1427                                         if (stat(mailbox, &mailstat) != 0 ||
1428                                             mailstat.st_size == 0)
1429                                                 printf("No mail.\n");
1430                                         else if (mailstat.st_mtime < mailstat.st_atime)
1431                                                 printf("You have mail.\n");
1432                                         else
1433                                                 printf("You have new mail.\n");
1434                                 }
1435                         }
1436                         /* Start the shell.  Set initial character to '-'. */
1437                         buf[0] = '-';
1438                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1439                         buf[sizeof(buf) - 1] = 0;
1440
1441                         /* Execute the shell. */
1442                         argv[0] = buf;
1443                         argv[1] = NULL;
1444                         execve(shell, argv, env);
1445
1446                         /* Executing the shell failed. */
1447                         perror(shell);
1448                         exit(1);
1449
1450                 } else {
1451                         /* Launch login(1). */
1452
1453                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1454                              "-p", "-f", "--", pw->pw_name, NULL);
1455
1456                         /* Login couldn't be executed, die. */
1457
1458                         perror("login");
1459                         exit(1);
1460                 }
1461         }
1462         /*
1463          * Execute the command using the user's shell.  This uses the -c
1464          * option to execute the command.
1465          */
1466         argv[0] = (char *) cp;
1467         argv[1] = "-c";
1468         argv[2] = (char *) command;
1469         argv[3] = NULL;
1470         execve(shell, argv, env);
1471         perror(shell);
1472         exit(1);
1473 }
1474
1475 Session *
1476 session_new(void)
1477 {
1478         int i;
1479         static int did_init = 0;
1480         if (!did_init) {
1481                 debug("session_new: init");
1482                 for(i = 0; i < MAX_SESSIONS; i++) {
1483                         sessions[i].used = 0;
1484                         sessions[i].self = i;
1485                 }
1486                 did_init = 1;
1487         }
1488         for(i = 0; i < MAX_SESSIONS; i++) {
1489                 Session *s = &sessions[i];
1490                 if (! s->used) {
1491                         s->pid = 0;
1492                         s->extended = 0;
1493                         s->chanid = -1;
1494                         s->ptyfd = -1;
1495                         s->ttyfd = -1;
1496                         s->term = NULL;
1497                         s->pw = NULL;
1498                         s->display = NULL;
1499                         s->screen = 0;
1500                         s->auth_data = NULL;
1501                         s->auth_proto = NULL;
1502                         s->used = 1;
1503                         s->pw = NULL;
1504                         debug("session_new: session %d", i);
1505                         return s;
1506                 }
1507         }
1508         return NULL;
1509 }
1510
1511 void
1512 session_dump(void)
1513 {
1514         int i;
1515         for(i = 0; i < MAX_SESSIONS; i++) {
1516                 Session *s = &sessions[i];
1517                 debug("dump: used %d session %d %p channel %d pid %d",
1518                     s->used,
1519                     s->self,
1520                     s,
1521                     s->chanid,
1522                     s->pid);
1523         }
1524 }
1525
1526 int
1527 session_open(int chanid)
1528 {
1529         Session *s = session_new();
1530         debug("session_open: channel %d", chanid);
1531         if (s == NULL) {
1532                 error("no more sessions");
1533                 return 0;
1534         }
1535         s->pw = auth_get_user();
1536         if (s->pw == NULL)
1537                 fatal("no user for session %d", s->self);
1538         debug("session_open: session %d: link with channel %d", s->self, chanid);
1539         s->chanid = chanid;
1540         return 1;
1541 }
1542
1543 Session *
1544 session_by_channel(int id)
1545 {
1546         int i;
1547         for(i = 0; i < MAX_SESSIONS; i++) {
1548                 Session *s = &sessions[i];
1549                 if (s->used && s->chanid == id) {
1550                         debug("session_by_channel: session %d channel %d", i, id);
1551                         return s;
1552                 }
1553         }
1554         debug("session_by_channel: unknown channel %d", id);
1555         session_dump();
1556         return NULL;
1557 }
1558
1559 Session *
1560 session_by_pid(pid_t pid)
1561 {
1562         int i;
1563         debug("session_by_pid: pid %d", pid);
1564         for(i = 0; i < MAX_SESSIONS; i++) {
1565                 Session *s = &sessions[i];
1566                 if (s->used && s->pid == pid)
1567                         return s;
1568         }
1569         error("session_by_pid: unknown pid %d", pid);
1570         session_dump();
1571         return NULL;
1572 }
1573
1574 int
1575 session_window_change_req(Session *s)
1576 {
1577         s->col = packet_get_int();
1578         s->row = packet_get_int();
1579         s->xpixel = packet_get_int();
1580         s->ypixel = packet_get_int();
1581         packet_done();
1582         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1583         return 1;
1584 }
1585
1586 int
1587 session_pty_req(Session *s)
1588 {
1589         u_int len;
1590         char *term_modes;       /* encoded terminal modes */
1591
1592         if (no_pty_flag)
1593                 return 0;
1594         if (s->ttyfd != -1)
1595                 return 0;
1596         s->term = packet_get_string(&len);
1597         s->col = packet_get_int();
1598         s->row = packet_get_int();
1599         s->xpixel = packet_get_int();
1600         s->ypixel = packet_get_int();
1601         term_modes = packet_get_string(&len);
1602         packet_done();
1603
1604         if (strcmp(s->term, "") == 0) {
1605                 xfree(s->term);
1606                 s->term = NULL;
1607         }
1608         /* Allocate a pty and open it. */
1609         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1610                 xfree(s->term);
1611                 s->term = NULL;
1612                 s->ptyfd = -1;
1613                 s->ttyfd = -1;
1614                 error("session_pty_req: session %d alloc failed", s->self);
1615                 xfree(term_modes);
1616                 return 0;
1617         }
1618         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1619         /*
1620          * Add a cleanup function to clear the utmp entry and record logout
1621          * time in case we call fatal() (e.g., the connection gets closed).
1622          */
1623         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1624         pty_setowner(s->pw, s->tty);
1625         /* Get window size from the packet. */
1626         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1627
1628         session_proctitle(s);
1629
1630         /* XXX parse and set terminal modes */
1631         xfree(term_modes);
1632         return 1;
1633 }
1634
1635 int
1636 session_subsystem_req(Session *s)
1637 {
1638         u_int len;
1639         int success = 0;
1640         char *subsys = packet_get_string(&len);
1641         int i;
1642
1643         packet_done();
1644         log("subsystem request for %s", subsys);
1645
1646         for (i = 0; i < options.num_subsystems; i++) {
1647                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1648                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1649                         do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1650                         success = 1;
1651                 }
1652         }
1653
1654         if (!success)
1655                 log("subsystem request for %s failed, subsystem not found", subsys);
1656
1657         xfree(subsys);
1658         return success;
1659 }
1660
1661 int
1662 session_x11_req(Session *s)
1663 {
1664         int fd;
1665         if (no_x11_forwarding_flag) {
1666                 debug("X11 forwarding disabled in user configuration file.");
1667                 return 0;
1668         }
1669         if (!options.x11_forwarding) {
1670                 debug("X11 forwarding disabled in server configuration file.");
1671                 return 0;
1672         }
1673         if (xauthfile != NULL) {
1674                 debug("X11 fwd already started.");
1675                 return 0;
1676         }
1677
1678         debug("Received request for X11 forwarding with auth spoofing.");
1679         if (s->display != NULL)
1680                 packet_disconnect("Protocol error: X11 display already set.");
1681
1682         s->single_connection = packet_get_char();
1683         s->auth_proto = packet_get_string(NULL);
1684         s->auth_data = packet_get_string(NULL);
1685         s->screen = packet_get_int();
1686         packet_done();
1687
1688         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1689         if (s->display == NULL) {
1690                 xfree(s->auth_proto);
1691                 xfree(s->auth_data);
1692                 return 0;
1693         }
1694         xauthfile = xmalloc(MAXPATHLEN);
1695         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1696         temporarily_use_uid(s->pw->pw_uid);
1697         if (mkdtemp(xauthfile) == NULL) {
1698                 restore_uid();
1699                 error("private X11 dir: mkdtemp %s failed: %s",
1700                     xauthfile, strerror(errno));
1701                 xfree(xauthfile);
1702                 xauthfile = NULL;
1703                 xfree(s->auth_proto);
1704                 xfree(s->auth_data);
1705                 /* XXXX remove listening channels */
1706                 return 0;
1707         }
1708         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1709         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1710         if (fd >= 0)
1711                 close(fd);
1712         restore_uid();
1713         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1714         return 1;
1715 }
1716
1717 int
1718 session_shell_req(Session *s)
1719 {
1720         /* if forced_command == NULL, the shell is execed */
1721         char *shell = forced_command;
1722         packet_done();
1723         s->extended = 1;
1724         if (s->ttyfd == -1)
1725                 do_exec_no_pty(s, shell, s->pw);
1726         else
1727                 do_exec_pty(s, shell, s->pw);
1728         return 1;
1729 }
1730
1731 int
1732 session_exec_req(Session *s)
1733 {
1734         u_int len;
1735         char *command = packet_get_string(&len);
1736         packet_done();
1737         if (forced_command) {
1738                 original_command = command;
1739                 command = forced_command;
1740                 debug("Forced command '%.500s'", forced_command);
1741         }
1742         s->extended = 1;
1743         if (s->ttyfd == -1)
1744                 do_exec_no_pty(s, command, s->pw);
1745         else
1746                 do_exec_pty(s, command, s->pw);
1747         if (forced_command == NULL)
1748                 xfree(command);
1749         return 1;
1750 }
1751
1752 int
1753 session_auth_agent_req(Session *s)
1754 {
1755         static int called = 0;
1756         packet_done();
1757         if (no_agent_forwarding_flag) {
1758                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1759                 return 0;
1760         }
1761         if (called) {
1762                 return 0;
1763         } else {
1764                 called = 1;
1765                 return auth_input_request_forwarding(s->pw);
1766         }
1767 }
1768
1769 void
1770 session_input_channel_req(int id, void *arg)
1771 {
1772         u_int len;
1773         int reply;
1774         int success = 0;
1775         char *rtype;
1776         Session *s;
1777         Channel *c;
1778
1779         rtype = packet_get_string(&len);
1780         reply = packet_get_char();
1781
1782         s = session_by_channel(id);
1783         if (s == NULL)
1784                 fatal("session_input_channel_req: channel %d: no session", id);
1785         c = channel_lookup(id);
1786         if (c == NULL)
1787                 fatal("session_input_channel_req: channel %d: bad channel", id);
1788
1789         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1790             s->self, id, rtype, reply);
1791
1792         /*
1793          * a session is in LARVAL state until a shell
1794          * or programm is executed
1795          */
1796         if (c->type == SSH_CHANNEL_LARVAL) {
1797                 if (strcmp(rtype, "shell") == 0) {
1798                         success = session_shell_req(s);
1799                 } else if (strcmp(rtype, "exec") == 0) {
1800                         success = session_exec_req(s);
1801                 } else if (strcmp(rtype, "pty-req") == 0) {
1802                         success =  session_pty_req(s);
1803                 } else if (strcmp(rtype, "x11-req") == 0) {
1804                         success = session_x11_req(s);
1805                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1806                         success = session_auth_agent_req(s);
1807                 } else if (strcmp(rtype, "subsystem") == 0) {
1808                         success = session_subsystem_req(s);
1809                 }
1810         }
1811         if (strcmp(rtype, "window-change") == 0) {
1812                 success = session_window_change_req(s);
1813         }
1814
1815         if (reply) {
1816                 packet_start(success ?
1817                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1818                 packet_put_int(c->remote_id);
1819                 packet_send();
1820         }
1821         xfree(rtype);
1822 }
1823
1824 void
1825 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1826 {
1827         if (!compat20)
1828                 fatal("session_set_fds: called for proto != 2.0");
1829         /*
1830          * now that have a child and a pipe to the child,
1831          * we can activate our channel and register the fd's
1832          */
1833         if (s->chanid == -1)
1834                 fatal("no channel for session %d", s->self);
1835         channel_set_fds(s->chanid,
1836             fdout, fdin, fderr,
1837             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1838             1);
1839 }
1840
1841 void
1842 session_pty_cleanup(Session *s)
1843 {
1844         if (s == NULL || s->ttyfd == -1)
1845                 return;
1846
1847         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1848
1849         /* Cancel the cleanup function. */
1850         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1851
1852         /* Record that the user has logged out. */
1853         record_logout(s->pid, s->tty);
1854
1855         /* Release the pseudo-tty. */
1856         pty_release(s->tty);
1857
1858         /*
1859          * Close the server side of the socket pairs.  We must do this after
1860          * the pty cleanup, so that another process doesn't get this pty
1861          * while we're still cleaning up.
1862          */
1863         if (close(s->ptymaster) < 0)
1864                 error("close(s->ptymaster): %s", strerror(errno));
1865 }
1866
1867 void
1868 session_exit_message(Session *s, int status)
1869 {
1870         Channel *c;
1871         if (s == NULL)
1872                 fatal("session_close: no session");
1873         c = channel_lookup(s->chanid);
1874         if (c == NULL)
1875                 fatal("session_close: session %d: no channel %d",
1876                     s->self, s->chanid);
1877         debug("session_exit_message: session %d channel %d pid %d",
1878             s->self, s->chanid, s->pid);
1879
1880         if (WIFEXITED(status)) {
1881                 channel_request_start(s->chanid,
1882                     "exit-status", 0);
1883                 packet_put_int(WEXITSTATUS(status));
1884                 packet_send();
1885         } else if (WIFSIGNALED(status)) {
1886                 channel_request_start(s->chanid,
1887                     "exit-signal", 0);
1888                 packet_put_int(WTERMSIG(status));
1889 #ifdef WCOREDUMP
1890                 packet_put_char(WCOREDUMP(status));
1891 #else /* WCOREDUMP */
1892                 packet_put_char(0);
1893 #endif /* WCOREDUMP */
1894                 packet_put_cstring("");
1895                 packet_put_cstring("");
1896                 packet_send();
1897         } else {
1898                 /* Some weird exit cause.  Just exit. */
1899                 packet_disconnect("wait returned status %04x.", status);
1900         }
1901
1902         /* disconnect channel */
1903         debug("session_exit_message: release channel %d", s->chanid);
1904         channel_cancel_cleanup(s->chanid);
1905         /*
1906          * emulate a write failure with 'chan_write_failed', nobody will be
1907          * interested in data we write.
1908          * Note that we must not call 'chan_read_failed', since there could
1909          * be some more data waiting in the pipe.
1910          */
1911         if (c->ostate != CHAN_OUTPUT_CLOSED)
1912                 chan_write_failed(c);
1913         s->chanid = -1;
1914 }
1915
1916 void
1917 session_free(Session *s)
1918 {
1919         debug("session_free: session %d pid %d", s->self, s->pid);
1920         if (s->term)
1921                 xfree(s->term);
1922         if (s->display)
1923                 xfree(s->display);
1924         if (s->auth_data)
1925                 xfree(s->auth_data);
1926         if (s->auth_proto)
1927                 xfree(s->auth_proto);
1928         s->used = 0;
1929 }
1930
1931 void
1932 session_close(Session *s)
1933 {
1934         session_pty_cleanup(s);
1935         session_free(s);
1936         session_proctitle(s);
1937 }
1938
1939 void
1940 session_close_by_pid(pid_t pid, int status)
1941 {
1942         Session *s = session_by_pid(pid);
1943         if (s == NULL) {
1944                 debug("session_close_by_pid: no session for pid %d", s->pid);
1945                 return;
1946         }
1947         if (s->chanid != -1)
1948                 session_exit_message(s, status);
1949         session_close(s);
1950 }
1951
1952 /*
1953  * this is called when a channel dies before
1954  * the session 'child' itself dies
1955  */
1956 void
1957 session_close_by_channel(int id, void *arg)
1958 {
1959         Session *s = session_by_channel(id);
1960         if (s == NULL) {
1961                 debug("session_close_by_channel: no session for channel %d", id);
1962                 return;
1963         }
1964         /* disconnect channel */
1965         channel_cancel_cleanup(s->chanid);
1966         s->chanid = -1;
1967
1968         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1969         if (s->pid == 0) {
1970                 /* close session immediately */
1971                 session_close(s);
1972         } else {
1973                 /* notify child, delay session cleanup */
1974                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1975                         error("session_close_by_channel: kill %d: %s",
1976                             s->pid, strerror(errno));
1977         }
1978 }
1979
1980 char *
1981 session_tty_list(void)
1982 {
1983         static char buf[1024];
1984         int i;
1985         buf[0] = '\0';
1986         for(i = 0; i < MAX_SESSIONS; i++) {
1987                 Session *s = &sessions[i];
1988                 if (s->used && s->ttyfd != -1) {
1989                         if (buf[0] != '\0')
1990                                 strlcat(buf, ",", sizeof buf);
1991                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1992                 }
1993         }
1994         if (buf[0] == '\0')
1995                 strlcpy(buf, "notty", sizeof buf);
1996         return buf;
1997 }
1998
1999 void
2000 session_proctitle(Session *s)
2001 {
2002         if (s->pw == NULL)
2003                 error("no user for session %d", s->self);
2004         else
2005                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2006 }
2007
2008 void
2009 do_authenticated2(Authctxt *authctxt)
2010 {
2011         /*
2012          * Cancel the alarm we set to limit the time taken for
2013          * authentication.
2014          */
2015         alarm(0);
2016         if (startup_pipe != -1) {
2017                 close(startup_pipe);
2018                 startup_pipe = -1;
2019         }
2020 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
2021         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
2022                 error("unable to get login class");
2023                 return;
2024         }
2025 #endif
2026         server_loop2();
2027         if (xauthfile)
2028                 xauthfile_cleanup_proc(NULL);
2029 }